JP2004077653A - Crosslink hardening type resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crosslink hardening type resin composition which forms a dry film resist having high adhesion strength between a supporting film and a crosslink hardening type resin layer. <P>SOLUTION: The crosslink hardening type resin composition consists of a thermoplastic resin for a binder (a polymeric substance comprising a mixture which contains unsaturated carboxylic acid, mono(meth)acrylate and mono(meth)acrylate having an alicyclic skeleton and which may contain styrene), polyfunctional (meth)acrylate, and a photopolymerization initiator. <P>COPYRIGHT: (C)2004,JPO

Description

【００１８】
〔一般式（１）において、Ｒ^１は水素原子又はメチル基である。〕
【００１９】
【化４】

【００２０】
〔一般式（２）において、Ｒ^２は水素原子又はメチル基である。〕
【００２１】
（Ａ）成分は、不飽和カルボン酸とＡ１との合計１００質量部に対しラジカル重合開始剤を好ましくは０．１〜１０質量部、更に好ましくは０．５〜５質量部加えて重合させるものである。このときの反応温度は、好ましくは４０〜１００℃、更に好ましくは６０〜９０℃であり、反応時間は、好ましくは２〜２０時間、更に好ましくは４〜１０時間である。
当該ラジカル重合開始剤としては、一般にラジカル重合開始剤として使用するアゾ化合物や過酸化物を使用することができ、好ましくはアゾ化合物である。
【００２２】
（Ａ）成分の質量平均分子量としては、現像時間及び耐コールドフロー性の点から、一万〜四十万の範囲が好ましく、より好ましくは三万〜二十万の範囲である。質量平均分子量が一万未満の場合にはドライフィルムレジストとした際にコールドフロー現象を起こしやすくなり、逆に質量平均分子量が四十万を超えたものは未露光部のアルカリ現像液に対する溶解性が不足するため、その現像性が低下しやすくなり、現像時間が長くかかりすぎて生産性を低下させてしまうおそれがある。
【００２３】
本発明の架橋硬化型樹脂組成物の重合成分（重合開始剤である（Ｃ）成分を除いたもの）に対し（Ａ）成分の含有割合は、４０〜７５質量部であることが好ましく、更に５０〜７０質量部が好ましい。（Ａ）成分の割合がこの範囲を外れると、支持フィルムに対する密着性を発現しない場合がある。
【００２４】
（Ｂ）成分
（Ｂ）成分は、（メタ）アクリロイル基を２個以上有する化合物である。
（Ｂ）成分の具体例として、ビスフェノールＦエチレンオキサイド変性ジ（メタ）アクリレート、ビスフェノールＡエチレンオキサイド変性ジ（メタ）アクリレート、ビスフェノールＺエチレンオキサイド変性ジ（メタ）アクリレート、イソシアヌル酸エチレンオキサイド変性ジ（メタ）アクリレート、トリプロピレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレートモノステアレート、ポリエチレングリコールジ（メタ）アクリレート及びポリプロピレングリコールジ（メタ）アクリレート等の２個の（メタ）アクリロイル基を有する（メタ）アクリレート、並びにペンタエリスリトールトリ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、トリメチロールプロパンプロピレンオキサイド変性トリ（メタ）アクリレート、イソシアヌル酸エチレンオキサイド変性トリ（メタ）アクリレート、トリメチロールプロパンプロピレンオキサイド変性トリ（メタ）アクリレート、トリメチロールプロパンエチレンオキサイド変性トリ（メタ）アクリレート等の３個の（メタ）アクリロイル基を有する（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート等の４個の（メタ）アクリロイル基を有する（メタ）アクリレート等を挙げることができる。これら以外にも、５個以上の（メタ）アクリロイル基を有する（メタ）アクリレートも使用可能である。
又、ポリエステル（メタ）アクリレート、ウレタン（メタ）アクリレートやエポキシ（メタ）アクリレート等のオリゴマーも使用することができる。
エポキシ（メタ）アクリレートとしては、グリセリンジグリシジルエーテル、トリメチロールプロパントリグリシジルエーテル及びトリグリシジルイソシアヌレート等のグリシジルエーテルの（メタ）アクリレート並びにビスフェノールＡ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂及びクレゾールノボラック型エポキシ樹脂等のエポキシ樹脂の（メタ）アクリレート等が挙げられる。
これら（Ｂ）成分は、単独で使用しても、２種以上を併用しても良い。
【００２５】
（Ｂ）成分としては、２〜６個の（メタ）アクロイル基を有するものが好ましく、ポリエチレングリコールジ（メタ）アクリレート及びポリプロピレングリコールジ（メタ）アクリレート等の２個の（メタ）アクリロイル基を有する（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート等の３個の（メタ）アクリロイル基を有する（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート等の４個の（メタ）アクリロイル基を有する（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート等のような５官能（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート等のような６官能（メタ）アクリレートが特に好ましく使用できる。
更に（Ｂ）成分としては、（メタ）アクリロイル基を２個有する化合物または／および３個有する化合物が更に好ましく、ポリプロピレングリコール（メタ）アクリロイル基を２個有する化合物または／およびペンタエリスリトールに（メタ）アクリロイル基を２個または３個有する化合物が特に好ましい。
【００２６】
本発明の架橋硬化型樹脂組成物の重合成分（重合開始剤である（Ｃ）成分を除いたもの）に対し（Ｂ）成分の含有割合としては、２５〜６０質量部であることが好ましく、２５〜５０質量部が特に好ましい。（Ｂ）成分の割合が２５質量部未満では、支持フィルムに対する密着性が低下する場合があり、一方、６０質量部を越える場合には、得られるドライフィルムレジストの架橋硬化型樹脂層のフィルム形成性が損なわれ、十分な膜強度が得られず、コールドフローが発生しやすくなるおそれがある。
【００２７】
（Ｃ）成分
（Ｃ）成分は、本発明の架橋硬化型樹脂組成物に添加する光重合開始剤である。
（Ｃ）成分の具体例としては、ベンゾイン、ベンゾインメチルエーテル及びベンゾインプロピルエーテル等のベンゾイン；アセトフェノン、２，２−ジメトキシ−２−フェニルアセトフェノン、２，２−ジエトキシ−２−フェニルアセトフェノン、１，１−ジクロロアセトフェノン、１−ヒドロキシシクロヘキシルフェニルケトン、２−メチル−１−［４−（メチルチオ）フェニル］−２−モルフォリノ−プロパン−１−オン及びＮ，Ｎ−ジメチルアミノアセトフェノン等のアセトフェノン；２−メチルアントラキノン、１−クロロアントラキノン及び２−アミルアントラキノン等のアントラキノン；２，４−ジメチルチオキサントン、２，４−ジエチルチオキサントン、２−クロロチオキサントン及び２，４−ジイソプロピルチオキサントン等のチオキサントン；アセトフェノンジメチルケタール及びベンジルジメチルケタール等のケタール；ベンゾフェノン、メチルベンゾフェノン、４，４’−ジクロロベンゾフェノン、４，４’−ビスジエチルアミノベンゾフェノン、ミヒラーズケトン及び４−ベンゾイル−４’−メチルジフェニルサルファイド等のベンゾフェノン；並びに２，４，６−トリメチルベンゾイルジフェニルホスフィンオキサイド等が挙げられる。
（Ｃ）成分は、単独で使用しても、２種以上を併用しても良い。
（Ｃ）成分には、必要に応じて光増感剤を併用することができる。光増感剤としては、Ｎ，Ｎ−ジメチルアミノ安息香酸エチルエステル、Ｎ，Ｎ−ジメチルアミノ安息香酸イソアミルエステル、トリエチルアミン及びトリエタノールアミン等が挙げられる。
【００２８】
（Ｃ）成分は、本発明の架橋硬化型樹脂組成物の重合成分（重合開始剤である（Ｃ）成分を除いたもの）に対し０．０５〜１２質量部を加えることが好ましく、更に０．５〜５質量部が特に好ましい。（Ｃ）成分が０．０５質量部に満たないと、十分な硬化性が得られないことがあり、一方、１２質量部を超えると経済性に問題がある場合がある。
【００２９】
本発明の架橋硬化型樹脂組成物は、活性エネルギー線を用いてフォトツールの回路図に従って硬化させることができる。この活性エネルギー線としては、紫外線、可視光、電子線などを用いることができるが、紫外線が好ましく使用することができる。
【００３０】
本発明の架橋硬化型樹脂組成物には、上記必須成分の他、目的に応じて種々の成分を配合することができる。
例えば、銅張り積層板等の基材との密着性を向上させるための密着促進剤を挙げることができる。
【００３１】
密着促進剤としては、従来公知のベンゾトリアゾール、ベンズイミダゾール等を使用することも可能であるが、少量の添加で金属面への密着性を向上させることができるテトラゾール又はその誘導体が好ましく、具体例としては、例えば、１−フェニルテトラゾール、５−フェニルテトラゾール、５−アミノテトラゾール、５−アミノー１−メチルテトラゾール、５−アミノ−２−フェニルテトラゾール、５−メルカプト−１−フェニルテトラゾール、５−メルカプト−１−メチルテトラゾール等が挙げられ、これらは一種又は二種以上を併用してもよい。
【００３２】
密着促進剤を使用する場合には、本発明の架橋硬化型樹脂組成物１００質量部に対して、０．００５〜５質量部が好ましく、０．１〜３質量部が特に好ましい。０．００５質量部未満では、基材との密着性の向上に効果が認められにくく、一方、５質量部を越えると本発明の架橋硬化型樹脂組成物への溶解に時間がかかってしまい、さらには得られる架橋硬化型樹脂組成物の感度も低下しやすい場合がある。
【００３３】
これら以外にも、重合禁止剤、染料、可塑剤、充填剤及び難燃剤等の各種添加剤を添加することもできる。
【００３４】
本発明の架橋硬化型樹脂組成物は、有機溶剤溶液として液状にて基材上に塗布して使用することもできるが、本発明の架橋硬化型樹脂組成物を支持フィルム上に塗布して架橋硬化型樹脂層としたドライフィルムレジストとして使用することが工業的に有利である。
【００３５】
本発明の架橋硬化型樹脂組成物を用いてドライフィルムレジストを形成させるには、ブレードコーター、ロッドコーター、ナイフコーター、ロールドクターコーター、コンマコーター、リバースロールコーター、トランスファロールコーター、グラビアコーター、キスロールコーター、カーテンコーター等を用いて塗布することもできるが、架橋硬化型樹脂組成物に溶剤を添加して使用する場合には、溶剤を飛散させる必要がある。ドライフィルムレジストの支持体としては、通常一般に用いられているポリエステル等のプラスチックフィルムが主に用いられる。乾燥機としては可燃性有機溶剤を使用する場合には安全性の点から蒸気による空気加熱式の熱源を備えたものを用い、乾燥機内の熱風を向流接触させる方式、ノズルより支持体に吹き付ける方式等が用いられる。又、乾燥機の形状は、アーチ式、フラット式等目的に合わせて選択して用いられる。本発明の架橋硬化型樹脂組成物をフィルムなどに塗布した後、保護のために保護フィルムを貼ることもできる。
【００３６】
本発明の架橋硬化型樹脂組成物を塗布したドライフィルムレジストを用いてプリント配線板を作製することができる。即ち、本発明の架橋硬化型樹脂組成物を塗布したドライフィルムレジストから保護フィルムを剥がして銅箔付き積層板に貼り付け、熱でラミネートする。次に、回路パターンを有するフォトツールを密着させる。その後、活性エネルギー線たとえば紫外線を照射し、当該組成物を硬化させる。フォトツールを当該フィルムから剥がし、次に支持フィルムを剥がして弱アルカリ水溶液（例えば１％炭酸ナトリウム水溶液）で未露光部分の組成物を溶かして（例えば、３０秒〜３分間）銅箔を露出させる。そして、露出部分の銅箔をエッチング処理し（例えば、４０〜６０℃の塩化第二鉄水溶液で３０秒〜３分間）、露出部分の銅箔を除去する。次に、銅箔上の硬化部分を剥膜処理（例えば、３０〜６０℃の３〜５％水酸化ナトリウム水溶液で３０秒〜３分間）し銅を露出させ、プリント配線板とすることができる。
【００３７】
【実施例】
以下、実施例及び比較例を挙げ、本発明をより具体的に説明する。
尚、以下において「部」とは質量部を意味する。
【００３８】
＜合成例１＞〔（Ａ）成分の製造〕
窒素導入管、攪拌装置、コンデンサー及び温度計を備えた１Ｌの４つ口フラスコに、メチルエチルケトン（以下ＭＥＫという）３００ｇを加え、窒素雰囲気下、８０℃に保持し、ついで下記モノマー混合物５００ｇ、及びアゾビスイソブチロニトリル（以下ＡＩＢＮという）５ｇからなる混合液を、５時間かけてフラスコ中に滴下した。
その後、さらにＡＩＢＮ１ｇ及びＭＥＫ５０ｇを加えて２時間熟成し、（Ａ）成分を製造した。ここで合成したものの質量平均分子量は３２，０００であった。
○モノマー混合物：メタクリル酸２５部、トリシクロデカンメチロールアクリレート〔前記式（１）においてＲ_１が水素原子の化合物〕３６部、メチルメタクリレート３５部、２−エチルヘキシルアクリレート４部。
【００３９】
＜合成例２＞〔（Ａ）成分の製造〕
合成例１と同様のフラスコに、ＭＥＫ３００ｇを加え、窒素雰囲気下、８０℃に保持し、下記モノマー混合物５００ｇ、ＡＩＢＮ５ｇ及びＭＥＫ５０ｇからなる混合液を、３時間かけてフラスコ中に滴下した。
その後、さらにＡＩＢＮ１ｇ及びＭＥＫ５０ｇを加えて２時間熟成し、（Ａ）成分を製造した。ここで合成したものの質量平均分子量は４１，０００であった。
○モノマー混合物：メタクリル酸２３部、トリシクロデカンメチロールアクリレート４５部、メチルメタクリレート１５部、ｎ−ブチルアクリレート３質量部、スチレン１４部。
【００４０】
＜合成例３＞〔（Ａ）成分の製造〕
合成例１と同様のフラスコに、ＭＥＫ２５０ｇを加え、窒素雰囲気下、８０℃に保持し、ついで下記モノマー混合物５００ｇ、ＭＥＫ５０ｇ、及びＡＩＢＮ５ｇからなる混合液を、５時間かけてフラスコ中に滴下した。その後、さらにＡＩＢＮ１ｇ及びＭＥＫ５０ｇを加えて２時間熟成し、（Ａ）成分を製造した。ここで合成したものの質量平均分子量は４７，０００であった。
○モノマー混合物：メタクリル酸１９部、ノルボルナンメチロールアクリレート〔前記式（２）においてＲ_２が水素原子である化合物〕２５部、エチルアクリレート１０部、メチルメタクリレート４３部、スチレン３部。
【００４１】
＜比較合成例１＞〔比較（Ａ）成分の製造〕
合成例１と同様のフラスコに、イソプロピルアルコール（以下ＩＰＡという）３００ｇを加え、窒素雰囲気下、８０℃に保持し、ついで下記モノマー混合物５００ｇ、及びＡＩＢＮ１０ｇからなる混合液を、５時間かけてフラスコ中に滴下した。その後、さらにＡＩＢＮ１ｇ及びＩＰＡ５０ｇを加えて２時間熟成し、（Ａ）成分と異なる熱可塑性重合体分を製造した。ここで合成したものの質量平均分子量は１２，０００であった。
○モノマー混合物：メタクリル酸２部、メチルメタクリレート５５部、スチレン３８部、２−エチルヘキシルアクリレート５部。
【００４２】
＜比較合成例２＞〔比較（Ａ）成分の製造〕
合成例１と同様のフラスコに、ＩＰＡ３００ｇを加え、窒素雰囲気下、８０℃に保持し、ついでモノマー混合物５００ｇ及びＡＩＢＮ１０ｇからなる混合液を、５時間かけてフラスコ中に滴下した。
その後、さらにＡＩＢＮ１ｇ及びＩＰＡ５０ｇを加えて２時間熟成し、（Ａ）成分と異なる熱可塑性重合体を製造した。ここで合成したものの質量平均分子量は１４，０００であった。
○モノマー混合物：メタクリル酸１９部、メチルメタクリレート１５部、ｎ−ブチルアクリレート３５部、エチルアクリレート３１部。
【００４３】
＜実施例１〜４、比較例１〜２＞
合成例１〜３、及び比較合成例１及び２で得られた熱可塑性樹脂を用いて、表１に示す成分を攪拌・混合し、架橋硬化型樹脂組成物を製造した。
得られた組成物を、プロペラ型ミキサーで攪拌し、減圧脱泡した後、ブレードコーターにより厚さ２０μｍ、幅５００ｍｍのポリエステルフィルム上に塗工幅３４０ｍｍで塗布した。ついで、乾燥機中で、熱風を送りながら塗工液を乾燥させて樹脂フィルムを得た。
ついで、塗膜面に厚さ３５μｍのポリエチレン製保護フィルムをラミネートして、ポリエステルフィルム（支持フィルム）、架橋硬化型樹脂組成物及び保護フィルムが積層されたドライフィルムレジストを得た。
得られたドライフィルムレジストを用いて、耐コールドフロー試験、密着性試験および現像性評価を行い、これらの結果を表１に示した。
表１中の数値は、質量部を意味し、（Ａ）成分については固形分換算の値である。
なお、表１における略号は以下の意味を示す。
Ｍ−３０５：ペンタエリスリトールトリアクリレート、東亞合成（株）製アロニックスＭ−３０５
Ｍ−２２５：ポリプロピレングリコールジアクリレート（ＰＯ付加モル数約７モル）、東亞合成（株）製アロニックスＭ−２２５
ＨＣＰＫ：１−ヒドロキシシクロヘキシルフェニルケトン
ＢＤＭＫ：ベンジルジメチルケタール
【００４４】
○耐コールドフロー試験
得られたドライフィルムレジストを、５ｃｍ×５ｃｍに切り取って試験片を作製したものを、試験片を垂直になるようにクリップ止めして室温で１ヶ月間放置し、端面からの樹脂のはみだしがないかを確認し、耐コールドフロー試験とした。目視ではみだしのないものを「○」、はみだしが認められたものを「×」とした。
【００４５】
○密着性試験
２枚のポリエステルフィルムの間に架橋硬化型樹脂組成物をはさみこんもの（ドライフィルムレジスト）を用いて、ポリエステルフィルムを９０度の角度で引き剥がし、このときの引き剥がし力を測定し、密着性の評価をおこなった。測定はＪＩＳ　Ｚ　０２３７に準拠しておこなった。
【００４６】
○現像性評価
保護フィルムを剥離したドライフィルムレジストを、銅張り積層板に熱ラミネートし、８０℃で２０分間放置したのちに現像性試験評価サンプルとした。次に、液温３０℃で１質量％炭酸ナトリウム水溶液をスプレー圧２．０ｋｇｆ／ｍｍ^２でスプレーし、６０秒後の塗膜の有無を目視で評価した。目視で塗膜のないものを「○」、残膜が認められるものを「×」とした。
【００４７】
【表１】

【００４８】
本発明の架橋硬化型樹脂組成物は、密着性が高いことから、本発明の架橋硬化型樹脂組成物を用いたドライフィルムレジストに対し粘着ロールのようなものでゴミや塵を除去しても、当該組成物から支持フィルムが剥がれるおそれがない。また、本発明の架橋硬化型樹脂組成物を保存しておいても、支持フィルムから流れ出すことがないことから、保存性にも優れている。
【００４９】
【発明の効果】
本発明の架橋硬化型樹脂組成物は、保存中の支持フィルムからのはみだしがなく、現像性及び密着性に優れることから、プリント配線基板を製造するためのドライフィルムレジストにおいて有用なものである。[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is an active energy ray-polymerizable crosslinkable resin composition that can be developed with a weak alkaline aqueous solution, and is industrially useful as a dry film resist.
[0002]
[Prior art]
In recent years, dry film resists have been widely used as photoresists for producing printed wiring boards. As a method of using an alkali-developing dry film resist having a protective film and a support film, first, a cross-linking curable resin is laminated on a copper-clad laminate by heat while peeling off the protective film from the dry film resist, and then A photo tool is brought into close contact with the support film surface of the resist film, and the exposed portions are cured with ultraviolet light or the like. Then, after peeling off the support film, the unexposed portion is developed and removed with a weak alkaline aqueous solution such as sodium carbonate, whereby a wiring pattern can be obtained.
[0003]
Especially in the ultraviolet exposure process, small dust and dirt enter between the supporting film and the photo tool, and the part to be cured is removed in the developing process without being exposed, which causes a disconnection trouble. Cheap. Heretofore, for such troubles, the influence of dust and dust has been reduced by slightly increasing the exposure amount to prevent disconnection.
[0004]
However, although the risk of disconnection is reduced by exposing more than the proper exposure amount, the wiring becomes thicker and the wiring density is higher, which causes problems such as short-circuit due to contact between wirings. Is starting to happen. Therefore, recently, between the laminating step and the exposing step, a new step of removing dirt and dust entering the support film with an adhesive roll has been introduced to solve the above-mentioned trouble. However, in the conventional dry film resist, since the adhesion between the support film and the cross-linking-curable resin layer is low, the support film is peeled off from the cross-linking-curable resin layer when removing dust and dust with an adhesive roll, causing distortion and air. Has a problem in that the exposed portion becomes poorly cured due to the polymerization inhibition effect of oxygen.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a cross-linked curable resin composition which forms a dry film resist having a high adhesion between a support film and a cross-linked curable resin layer in order to solve the above-mentioned problems.
[0006]
[Means for Solving the Problems]
The present inventor has conducted various studies in order to solve the above-mentioned problems. As a result, the thermoplastic resin for the binder (unsaturated carboxylic acid, mono (meth) acrylate and mono (meth) acrylate having an alicyclic skeleton and It has been found that this problem can be solved by using a cross-linking curable resin composition comprising a polymer which is a mixture which may contain styrene), a polyfunctional (meth) acrylate and a photopolymerization initiator. completed.
Hereinafter, the present invention will be described in detail.
In the present specification, a crosslinked curable resin composition of the present invention coated on a film (support film) and provided with a protective film is referred to as a dry film resist. Also, acrylate or methacrylate is referred to as (meth) acrylate, and acryloyl group or methacryloyl group is referred to as (meth) acryloyl group.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention
Component (A): A1 [A1 is a mixture of mono (meth) acrylate having an alicyclic skeleton and mono (meth) acrylate which may contain styrene] and an unsaturated carboxylic acid A polymer as a unit,
Component (B): a compound having two or more (meth) acryloyl groups and component (C): a cross-linking curable resin composition comprising: a photopolymerization initiator.
Hereinafter, each of the components will be described.
[0008]
Component (A) The component (A) is a polymer composed of 5 to 50 parts by mass of an unsaturated carboxylic acid and 50 to 95 parts by mass of A1, and the A1 is a mono (meta) having an alicyclic skeleton in A1. A) a mixture with a mono (meth) acrylate which may contain styrene and contains 5 to 65 parts by mass of an acrylate. This component functions as a binder (a thermoplastic resin for a binder).
[0009]
Specific examples of the unsaturated carboxylic acid constituting the component (A) include, for example, (meth) acrylic acid, crotonic acid, cinnamic acid, sorbic acid, itaconic acid, fumaric acid, and maleic acid. In the case of an anhydride or a polybasic acid, half esters can also be used. These unsaturated carboxylic acids may be used alone or in combination of two or more. Among these, (meth) acrylic acid is preferred, and methacrylic acid is particularly preferred, in view of the development time of the crosslinked curable resin composition with a weak alkaline aqueous solution and the solubility of the cured product in a stripping solution in a stripping step.
[0010]
The proportion of the unsaturated carboxylic acid in the component (A) is preferably from 5 to 50 parts by mass, more preferably from 10 to 40 parts by mass. If the amount is less than 5 parts by mass, development may not be possible with a weak alkaline aqueous solution, or the development time may be too long and the resolution may be reduced. If the amount exceeds 50 parts by mass, a support film of a cross-linkable curable resin composition may be used. In some cases, the adhesion to the substrate may be reduced.
[0011]
The proportion of A1 in the component (A) is preferably from 50 to 95 parts by mass, more preferably from 60 to 90 parts by mass. If the amount is less than 50 parts by mass, the adhesion of the cross-linked curable resin composition to the support film may be reduced. If the amount is more than 95 parts by mass, the developing time may be too long and the resolution may be reduced.
[0012]
Specific examples of the mono (meth) acrylate contained in A1 other than the mono (meth) acrylate having an alicyclic skeleton include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth). It is an ester of (meth) acrylic acid with an alkyl alcohol having 1 to 20 carbon atoms which may have a branch such as acrylate and 2-ethylhexyl (meth) acrylate, and preferably has a branch having 1 to 12 carbon atoms. And an ester with an alkyl alcohol.
These mono (meth) acrylates may be used alone or in combination of two or more.
[0013]
In A1, a mono (meth) acrylate having an alicyclic skeleton is preferably contained in an amount of 5 to 65 parts by mass, more preferably 10 to 60 parts by mass, and particularly preferably 20 to 60 parts by mass. Is preferred.
The mono (meth) acrylate having this alicyclic skeleton is used for improving the adhesion to the support film and improving the hardness of the coating film. If the proportion is less than 5 parts by mass, the effect of improving the adhesion may not be obtained in some cases. If the proportion exceeds 65 parts by mass, problems such as a long developing time and a long peeling time may occur.
[0014]
In A1, the mono (meth) acrylate other than the mono (meth) acrylate having an alicyclic skeleton is preferably contained in an amount of 5 to 65 parts by mass, more preferably 10 to 60 parts by mass, In particular, it is preferably contained in an amount of 20 to 60 parts by mass.
[0015]
Styrene in A1 is effective for improving the adhesion of the support film to the support film. However, if it is too large, the development time and the peeling time may be long. Therefore, when styrene is contained in A1, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less in A1.
[0016]
As the mono (meth) acrylate having an alicyclic skeleton, various (meth) acrylates can be used, and a compound represented by the following general formula (1) or / and (2) is preferable.
[0017]
Embedded image

[0018]
[In the general formula (1), R ¹ is a hydrogen atom or a methyl group. ]
[0019]
Embedded image

[0020]
[In the general formula (2), R ² is a hydrogen atom or a methyl group. ]
[0021]
The component (A) is obtained by adding 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, of the radical polymerization initiator to the total of 100 parts by mass of the unsaturated carboxylic acid and A1 for polymerization. It is. At this time, the reaction temperature is preferably 40 to 100 ° C, more preferably 60 to 90 ° C, and the reaction time is preferably 2 to 20 hours, more preferably 4 to 10 hours.
As the radical polymerization initiator, an azo compound or a peroxide generally used as a radical polymerization initiator can be used, and an azo compound is preferable.
[0022]
The mass average molecular weight of the component (A) is preferably from 10,000 to 400,000, more preferably from 30,000 to 200,000, from the viewpoint of development time and cold flow resistance. When the weight average molecular weight is less than 10,000, a cold flow phenomenon easily occurs when a dry film resist is used, and when the weight average molecular weight exceeds 400,000, the solubility of an unexposed portion in an alkali developing solution is insufficient. Therefore, the developability tends to decrease, and the development time may be too long to lower the productivity.
[0023]
The content of the component (A) is preferably from 40 to 75 parts by mass with respect to the polymerization component (excluding the component (C) as a polymerization initiator) of the cross-linkable curable resin composition of the present invention. 50 to 70 parts by mass are preferred. If the proportion of the component (A) is out of this range, the adhesion to the support film may not be exhibited.
[0024]
Component (B) The component (B) is a compound having two or more (meth) acryloyl groups.
Specific examples of the component (B) include bisphenol F ethylene oxide-modified di (meth) acrylate, bisphenol A ethylene oxide-modified di (meth) acrylate, bisphenol Z ethylene oxide-modified di (meth) acrylate, and isocyanuric acid ethylene oxide-modified di (meth) acrylate. 2) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate (Meth) acrylate having a (meth) acryloyl group, pentaerythritol tri (meth) acrylate, trimethylolpropane tri ) Acrylate, trimethylolpropane propylene oxide modified tri (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, trimethylolpropane propylene oxide modified tri (meth) acrylate, trimethylolpropane ethylene oxide modified tri (meth) acrylate, etc. (Meth) acrylate having four (meth) acryloyl groups, such as (meth) acrylate having three (meth) acryloyl groups, and pentaerythritol tetra (meth) acrylate. Besides these, (meth) acrylates having five or more (meth) acryloyl groups can also be used.
In addition, oligomers such as polyester (meth) acrylate, urethane (meth) acrylate and epoxy (meth) acrylate can also be used.
Epoxy (meth) acrylates include (meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether and triglycidyl isocyanurate, and bisphenol A epoxy resin, phenol novolak epoxy resin and cresol novolak epoxy (Meth) acrylates of epoxy resins such as resins, and the like.
These components (B) may be used alone or in combination of two or more.
[0025]
As the component (B), those having 2 to 6 (meth) acryloyl groups are preferable, and those having two (meth) acryloyl groups such as polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate. (Meth) acrylate having three (meth) acryloyl groups such as (meth) acrylate, trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate, and four such as pentaerythritol tetra (meth) acrylate A pentafunctional (meth) acrylate such as (meth) acrylate having a (meth) acryloyl group, dipentaerythritol penta (meth) acrylate, and a hexafunctional (meth) acrylate such as dipentaerythritol hexa (meth) acrylate Special It can be preferably used.
Further, as the component (B), a compound having two (meth) acryloyl groups and / or a compound having three (meth) acryloyl groups are more preferable, and a compound having two polypropylene glycol (meth) acryloyl groups or / and pentaerythritol having (meth) Compounds having two or three acryloyl groups are particularly preferred.
[0026]
The content of the component (B) is preferably 25 to 60 parts by mass with respect to the polymerization component (excluding the component (C) which is a polymerization initiator) of the crosslinkable resin composition of the present invention. 25 to 50 parts by weight are particularly preferred. When the proportion of the component (B) is less than 25 parts by mass, the adhesion to the support film may be reduced. On the other hand, when the proportion exceeds 60 parts by mass, the film formation of the crosslinked and cured resin layer of the obtained dry film resist may be performed. Properties may be impaired, sufficient film strength may not be obtained, and cold flow may easily occur.
[0027]
Component (C) The component (C) is a photopolymerization initiator to be added to the crosslinked curable resin composition of the present invention.
Specific examples of the component (C) include benzoin such as benzoin, benzoin methyl ether and benzoin propyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and 1,1. Acetophenones such as -dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one and N, N-dimethylaminoacetophenone; 2-methyl Anthraquinones such as anthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone Thioxanthone, etc .; ketals, such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, 4-benzoyl-4′-methyldiphenyl sulfide, etc. And 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
The component (C) may be used alone or in combination of two or more.
A photosensitizer can be used in combination with the component (C), if necessary. Examples of the photosensitizer include N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethylamine and triethanolamine.
[0028]
The component (C) is preferably added in an amount of 0.05 to 12 parts by mass, and more preferably 0 to 12 parts by mass, based on the polymerization component (excluding the polymerization initiator (C) component) of the cross-linkable curable resin composition of the present invention. 0.5 to 5 parts by mass are particularly preferred. If the amount of the component (C) is less than 0.05 part by mass, sufficient curability may not be obtained. On the other hand, if the amount exceeds 12 parts by mass, there may be a problem in economy.
[0029]
The cross-linking curable resin composition of the present invention can be cured according to a circuit diagram of a phototool using active energy rays. As the active energy ray, ultraviolet light, visible light, electron beam and the like can be used, but ultraviolet light is preferably used.
[0030]
In addition to the above-mentioned essential components, various components can be added to the crosslinked-curable resin composition of the present invention depending on the purpose.
For example, an adhesion promoter for improving adhesion to a substrate such as a copper-clad laminate can be used.
[0031]
As the adhesion promoter, conventionally known benzotriazole, benzimidazole and the like can be used, but tetrazole or a derivative thereof, which can improve adhesion to a metal surface with a small amount of addition, is preferred. Examples thereof include 1-phenyltetrazole, 5-phenyltetrazole, 5-aminotetrazole, 5-amino-1-methyltetrazole, 5-amino-2-phenyltetrazole, 5-mercapto-1-phenyltetrazole, 5-mercapto- Examples thereof include 1-methyltetrazole and the like, and these may be used alone or in combination of two or more.
[0032]
When an adhesion promoter is used, the amount is preferably 0.005 to 5 parts by mass, and particularly preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the crosslinked curable resin composition of the present invention. If the amount is less than 0.005 parts by mass, the effect of improving the adhesion to the substrate is hardly recognized, while if it exceeds 5 parts by mass, it takes time to dissolve in the crosslinked curable resin composition of the present invention, Further, the sensitivity of the obtained cross-linkable curable resin composition may be easily reduced.
[0033]
In addition, various additives such as a polymerization inhibitor, a dye, a plasticizer, a filler and a flame retardant can be added.
[0034]
The crosslinked curable resin composition of the present invention can be used by applying it on a substrate in a liquid form as an organic solvent solution, but the crosslinked curable resin composition of the present invention is applied onto a support film and crosslinked. It is industrially advantageous to use it as a dry film resist as a curable resin layer.
[0035]
In order to form a dry film resist using the crosslinked curable resin composition of the present invention, a blade coater, a rod coater, a knife coater, a roll doctor coater, a comma coater, a reverse roll coater, a transfer roll coater, a gravure coater, a kiss roll The coating can be carried out using a coater, a curtain coater or the like, but when a solvent is added to the cross-linking curable resin composition for use, it is necessary to disperse the solvent. As a support for the dry film resist, a plastic film such as polyester generally used is mainly used. When using a flammable organic solvent as the dryer, use a device equipped with an air-heated heat source using steam from the viewpoint of safety, in which the hot air inside the dryer is brought into countercurrent contact, and sprayed from the nozzle onto the support A method or the like is used. The shape of the dryer is selected and used according to the purpose, such as an arch type or a flat type. After applying the crosslinked curable resin composition of the present invention to a film or the like, a protective film can be applied for protection.
[0036]
A printed wiring board can be manufactured using a dry film resist coated with the cross-linking-curable resin composition of the present invention. That is, the protective film is peeled off from the dry film resist coated with the cross-linking-curable resin composition of the present invention, attached to a laminate with copper foil, and laminated by heat. Next, a photo tool having a circuit pattern is brought into close contact with the photo tool. Thereafter, the composition is irradiated with an active energy ray such as an ultraviolet ray to cure the composition. The photo tool is peeled off from the film, then the support film is peeled off, and the unexposed portion of the composition is dissolved with a weak alkaline aqueous solution (for example, a 1% aqueous solution of sodium carbonate) to expose the copper foil (for example, for 30 seconds to 3 minutes). . Then, the exposed portion of the copper foil is etched (for example, with a ferric chloride aqueous solution at 40 to 60 ° C. for 30 seconds to 3 minutes) to remove the exposed portion of the copper foil. Next, the hardened portion on the copper foil is subjected to a film removing treatment (for example, by using a 3 to 5% sodium hydroxide aqueous solution at 30 to 60 ° C. for 30 seconds to 3 minutes) to expose the copper, thereby obtaining a printed wiring board. .
[0037]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the following, “parts” means parts by mass.
[0038]
<Synthesis Example 1> [Production of component (A)]
300 g of methyl ethyl ketone (hereinafter referred to as MEK) was added to a 1-L four-necked flask equipped with a nitrogen inlet tube, a stirrer, a condenser and a thermometer, kept at 80 ° C. under a nitrogen atmosphere, and then 500 g of the following monomer mixture and azo A mixed solution consisting of 5 g of bisisobutyronitrile (hereinafter referred to as AIBN) was dropped into the flask over 5 hours.
Thereafter, 1 g of AIBN and 50 g of MEK were further added and aged for 2 hours to produce the component (A). The mass average molecular weight of the compound synthesized here was 32,000.
O Monomer mixture: 25 parts of methacrylic acid, 36 parts of tricyclodecanemethylol acrylate [compound of formula (1) wherein R ₁ is a hydrogen atom], 35 parts of methyl methacrylate, 4 parts of 2-ethylhexyl acrylate.
[0039]
<Synthesis Example 2> [Production of component (A)]
300 g of MEK was added to the same flask as in Synthesis Example 1, and the mixture was kept at 80 ° C. under a nitrogen atmosphere, and a mixed solution composed of 500 g of the following monomer mixture, 5 g of AIBN, and 50 g of MEK was dropped into the flask over 3 hours.
Thereafter, 1 g of AIBN and 50 g of MEK were further added and aged for 2 hours to produce the component (A). The mass average molecular weight of the synthesized product was 41,000.
O Monomer mixture: 23 parts of methacrylic acid, 45 parts of tricyclodecanemethylol acrylate, 15 parts of methyl methacrylate, 3 parts by weight of n-butyl acrylate, 14 parts of styrene.
[0040]
<Synthesis Example 3> [Production of component (A)]
250 g of MEK was added to the same flask as in Synthesis Example 1, and the mixture was kept at 80 ° C. under a nitrogen atmosphere, and then a mixed solution comprising 500 g of the following monomer mixture, 50 g of MEK, and 5 g of AIBN was dropped into the flask over 5 hours. Thereafter, 1 g of AIBN and 50 g of MEK were further added and aged for 2 hours to produce the component (A). The mass average molecular weight of the synthesized product was 47,000.
モ ノ マ ー Monomer mixture: 19 parts of methacrylic acid, 25 parts of norbornane methylol acrylate [compound of formula (2) wherein R ₂ is a hydrogen atom], 10 parts of ethyl acrylate, 43 parts of methyl methacrylate, and 3 parts of styrene.
[0041]
<Comparative Synthesis Example 1> [Production of Comparative (A) Component]
300 g of isopropyl alcohol (hereinafter referred to as IPA) was added to the same flask as in Synthesis Example 1, and the mixture was kept at 80 ° C. under a nitrogen atmosphere. Then, a mixed solution containing 500 g of the following monomer mixture and 10 g of AIBN was added to the flask over 5 hours. Was dropped. Thereafter, 1 g of AIBN and 50 g of IPA were further added, and the mixture was aged for 2 hours to produce a thermoplastic polymer different from the component (A). The mass average molecular weight of the compound synthesized here was 12,000.
O Monomer mixture: 2 parts of methacrylic acid, 55 parts of methyl methacrylate, 38 parts of styrene, 5 parts of 2-ethylhexyl acrylate.
[0042]
<Comparative Synthesis Example 2> [Production of Comparative (A) Component]
300 g of IPA was added to the same flask as in Synthesis Example 1, and the mixture was kept at 80 ° C. under a nitrogen atmosphere, and then a mixed solution comprising 500 g of the monomer mixture and 10 g of AIBN was dropped into the flask over 5 hours.
Thereafter, 1 g of AIBN and 50 g of IPA were further added and aged for 2 hours to produce a thermoplastic polymer different from the component (A). The mass average molecular weight of the compound synthesized here was 14,000.
○ Monomer mixture: 19 parts of methacrylic acid, 15 parts of methyl methacrylate, 35 parts of n-butyl acrylate, 31 parts of ethyl acrylate.
[0043]
<Examples 1-4 and Comparative Examples 1-2>
Using the thermoplastic resins obtained in Synthetic Examples 1 to 3 and Comparative Synthetic Examples 1 and 2, the components shown in Table 1 were stirred and mixed to produce a cross-linked curable resin composition.
The obtained composition was stirred with a propeller type mixer, defoamed under reduced pressure, and then applied to a polyester film having a thickness of 20 μm and a width of 500 mm with a blade coater at a coating width of 340 mm. Next, the coating liquid was dried in a dryer while sending hot air thereto to obtain a resin film.
Next, a polyethylene protective film having a thickness of 35 μm was laminated on the coating film surface to obtain a dry film resist in which a polyester film (support film), a cross-linkable curable resin composition, and a protective film were laminated.
Using the obtained dry film resist, a cold flow resistance test, an adhesion test and an evaluation of developability were performed. The results are shown in Table 1.
The numerical values in Table 1 mean parts by mass, and the component (A) is a value in terms of solid content.
The abbreviations in Table 1 have the following meanings.
M-305: pentaerythritol triacrylate, Aronix M-305 manufactured by Toagosei Co., Ltd.
M-225: polypropylene glycol diacrylate (approximately 7 moles of PO added), Aronix M-225 manufactured by Toagosei Co., Ltd.
HCPK: 1-hydroxycyclohexyl phenyl ketone BDKM: benzyl dimethyl ketal
○ Cold flow resistance test The obtained dry film resist was cut into 5 cm x 5 cm to prepare a test piece, which was clipped so that the test piece was vertical, left at room temperature for one month, and The resin was checked for protrusion, and a cold flow resistance test was performed. Those that did not protrude visually were marked with “○”, and those that were protruded were marked with “x”.
[0045]
○ Adhesion test The polyester film is peeled at an angle of 90 degrees using a cross-linked curable resin composition sandwiched between two polyester films (dry film resist), and the peeling force at this time is measured. Then, the adhesion was evaluated. The measurement was performed according to JIS Z0237.
[0046]
現 像 Evaluation of developability The dry film resist from which the protective film was peeled off was thermally laminated on a copper-clad laminate, left at 80 ° C. for 20 minutes, and then used as an evaluation sample for developability test. Next, a 1% by mass aqueous solution of sodium carbonate was sprayed at a liquid temperature of 30 ° C. at a spray pressure of 2.0 kgf / mm ² , and the presence or absence of a coating film after 60 seconds was visually evaluated. A sample without a coating film was visually evaluated as "O", and a sample with a residual film was evaluated as "X".
[0047]
[Table 1]

[0048]
The cross-linking-curable resin composition of the present invention has high adhesiveness, and even when removing dirt or dust with an adhesive roll or the like for a dry film resist using the cross-linking-curable resin composition of the present invention. Therefore, there is no possibility that the support film is peeled off from the composition. Further, even if the crosslinked curable resin composition of the present invention is stored, it does not flow out of the support film, and thus has excellent storage stability.
[0049]
【The invention's effect】
The cross-linking curable resin composition of the present invention does not protrude from the support film during storage and is excellent in developability and adhesion, and thus is useful in a dry film resist for producing a printed wiring board.

Claims (4)

Component (A): A1 [A1 is a mixture of a mono (meth) acrylate having an alicyclic skeleton and containing 5 to 65 parts by mass of a mono (meth) acrylate which may contain styrene] A polymer comprising from 5 to 50 parts by mass of an unsaturated carboxylic acid and 5 to 50 parts by mass of a polymer (B): a compound having two or more (meth) acryloyl groups and a component (C): a photopolymerization initiator. And a cross-linking curable resin composition. The cross-linking curable resin composition according to claim 1, wherein the mono (meth) acrylate having an alicyclic skeleton in A1 is a compound represented by the following general formula (1) or / and (2). object.

[In the general formula (1), R ¹ is a hydrogen atom or a methyl group. ]

[In the general formula (2), R ² is a hydrogen atom or a methyl group. ] A dry film resist using the cross-linkable curable resin composition according to claim 1 or 2. A printed wiring board obtained by irradiating the dry film resist according to claim 3 with an active energy ray.