JP3839543B2 - Active energy ray-curable resin composition - Google Patents

Description

【０００６】
（式中、Ｒ¹は水素原子、炭素数１〜６のアルキル基、フッ素原子、炭素数１〜６のフルオロアルキル基、アリル基、アリール基、アラルキル基、フリル基又はチエニル基を示す）
で表わされるオキセタン官能基とエポキシ基を同一分子内に併有する樹脂、及び
（Ｂ） 光カチオン重合開始剤
を含有することを特徴とする活性エネルギー線硬化性樹脂組成物が提供される。
以下、本発明の樹脂組成物についてさらに詳細に説明する。
【０００７】
オキセタン官能基とエポキシ基を同一分子内に併有する樹脂（Ａ）：
本発明の樹脂組成物は、架橋官能基として前記式（Ｉ）で表わされるオキセタン官能基とエポキシ基の両者を１分子中に併有する樹脂（Ａ）を、主たる樹脂成分として含んでなる点に特徴を有する。
【０００８】
前記式（Ｉ）中のＲ¹の定義において、「炭素数１〜６のアルキル基」は直鎖状又は分岐状のものであってもよく、例えば、メチル、エチル、ｎ−プロピル、イソプロピル、ｎ−ブチル、イソブチル、ｓｅｃ−ブチル、ｔｅｒｔ−ブチル、ｎ−ヘキシル等が挙げられる。「炭素数１〜６のフルオロアルキル基」は上記アルキル基の水素原子の少なくとも１個がフッ素原子で置換された基であり、例えば、フルオロプロピル、フルオロブチル、トリフルオロプロピル等が挙げられる。「アリール基」は単環式又は多環式であることができ、また、芳香環が１個又はそれ以上の炭素数１〜６のアルキル基で置換されていてもよく、例えば、フェニル、トルイル、キシリル、ナフチル等が挙げられる。「アラルキル基」は、アリール部分及びアルキル部分がそれぞれ上記の意味を有するアリール−アルキル基であり、例えば、ベンジル、フェネチル等が挙げられる。
【０００９】
Ｒ¹としては中でも炭素数１〜６、殊に炭素数１〜４のアルキル基 、例えば、メチル、エチルが好適である。
【００１０】
該オキセタン官能基は、エーテル結合、エステル結合、ウレタン結合等の酸素を含有する結合又はこれらの１種以上の結合を含む炭化水素鎖を介して樹脂（Ａ）の側鎖又は主鎖に結合していることが好ましい。
【００１１】
オキセタン官能基は、樹脂（Ａ）中に１分子あたり平均して少なくとも約２個以上、好ましくは平均約２〜約１００個、より好ましくは平均約２〜約５０個の割合で存在することができる。
【００１２】
一方、エポキシ基は、樹脂（Ａ）中に１分子あたり平均して少なくとも約２個以上、好ましくは平均約２〜約１００個、より好ましくは平均約２〜約５０個の割合で存在することができる。
【００１３】
また、樹脂（Ａ）は、塗料分野でよく用いられる有機溶剤に可溶性であるか、或いは水性媒体に分散ないし可溶性であることが好ましく、一般に、約３００〜約２００,０００、好ましくは約５００〜約１００,０００、より好ましくは約１,０００〜約５０,０００の数平均分子量を有するものが適している。
【００１４】
樹脂（Ａ）の種類は、特に制限されず、アクリル系、ポリエステル系、ポリウレタン系、ポリエーテル系等の各種の樹脂を用いることができるが、本発明の樹脂組成物を塗料として用いる場合には、塗膜の耐候性、耐久性等の点から、特に、アクリル系樹脂が好適である。
【００１５】
前記式（Ｉ）のオキセタン官能基とエポキシ基を併有するアクリル系樹脂は、例えば、
（ａ） 分子の一端に式（Ｉ）のオキセタン官能基を有し且つ他端にラジカル重合性不飽和基を有する不飽和モノマー及び
（ｂ） エポキシ基含有アクリル系不飽和モノマーを場合により
（ｃ） 他の共重合可能なラジカル重合性不飽和モノマー
と共に共重合することにより製造することができる。
【００１６】
上記のオキセタン官能基含有不飽和モノマー（ａ）としては、例えば、下記式
【００１７】
【化１２】

【００１８】
式中、Ｒ¹は前記と同義である、
で表わされる３−ヒドロキシメチルオキセタン化合物を、上記式（ＩＩ）中の水酸基と相補的に反応するが、しかしオキセタン基とは実質的に反応しない相補性官能基、例えば、イソシアネート基、低級アルコキシ基（例えば、メトキシ、エトキシ）、低級アルコキシカルボニル基（例えば、メトキシカルボニル、エトキシカルボニル）等を一端に有し且つ他端にラジカル重合性不飽和基、例えばアクリロイル基、メタクリロイル基、ビニル基を有する不飽和化合物と反応させることにより得ることができる。
【００１９】
上記式（ＩＩ）の化合物、例えば、３−エチル−３−ヒドロキシメチルオキセタンは、トリメチロールプロパンを炭酸ジエチルと反応させて水酸基含有環状カーボネートを製造し、次いで脱炭酸することにより製造することができる。
【００２０】
また、式（ＩＩ）の化合物と反応せしめられる上記不飽和化合物としては、例えば、（メタ）アクリル酸、（メタ）アクリル酸メチル、（メタ）アクリル酸イソシアネートエチル、ｍ−イソプロペニル−α,α−ジメチルベンジルイソシアネート、Ｎ−メトキシメチル（メタ）アクリルアミド、Ｎ−ブトキシメチル（メタ）アクリルアミド、メチルビニルエーテル、エチルビニルエーテル等が挙げられる。
【００２１】
上記のエポキシ基含有アクリル系不飽和モノマー（ｂ）としては、例えば、グリシジル（メタ）アクリレート、３,４−エポキシシクロヘキシルメチル（メタ）アクリレート等が挙げられる。
【００２２】
上記モノマー（ａ）及び（ｂ）と共重合可能なラジカル重合性不飽和モノマーとしては、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ブチル（メタ）アクリレート、２−エチルヘキシル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート等の（メタ）アクリル酸のＣ₁〜Ｃ₂₄のアルキル又はシクロアルキルエステル類；２−ヒドロキシプロピル（メタ）アクリレート、カプロラクトン変性（メタ）アクリル酸ヒドロキシエチル等の（メタ）アクリル酸のＣ₂〜Ｃ₈ヒドロキシアルキルエステル類；（メタ）アクリル酸等のカルボキシル基含有不飽和モノマー類；スチレン、α−メチルスチレン、ビニルトルエン等の芳香族ビニル化合物類；パーフルオロブチルエチル（メタ）アクリレート、パーフルオロイソノニルエチル（メタ）アクリレート等の含フッ素不飽和モノマー類；（メタ）アクリルアミド等の重合性アミド類；（メタ）アクリロニトリル等の重合性ニトリル類などが挙げられる。これらのモノマーは、形成される樹脂に望まれる特性に応じて１種又は２種以上を適宜選択して用いることができる。
【００２３】
上記モノマー（ａ）、（ｂ）及び（ｃ）の共重合は、それ自体既知の方法、例えば、溶液重合、懸濁重合、乳化重合、塊状重合等の方法により行なうことができる。
【００２４】
光カチオン重合開始剤（Ｂ）：
本発明で使用する光カチオン重合開始剤（Ｂ）は、活性エネルギー線によってカチオンを発生して、オキセタン官能基及びエポキシ基のカチオン重合を開始させる化合物であり、例えば、下記式（ＩＩＩ）〜（ＸＩＶ）で表わされるヘキサフルオロアンチモネート塩、ペンタフルオロヒドロキシアンチモネート塩、ヘキサフルオロホスフェート塩、ヘキサフルオロアルゼネート塩及びその他の光カチオン重合開始剤を挙げることができる。
【００２５】
Ａｒ₂Ｉ⁺・Ｘ^- （ＩＩＩ）
［式中、Ａｒはアリール基、例えばフェニル基を表わし、Ｘ^-はＰＦ₆ ^-、ＳｂＦ₆ ^-、又はＡｓＦ₆ ^-を表わす］
Ａｒ₃Ｓ⁺・Ｘ^- （ＩＶ）
［式中、Ａｒ及びＸ^-は上記と同じ意味を有する］
【００２６】
【化１３】

【００２７】
［式中、Ｒ²は炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表わし、ｎは０〜３の整数を表わし、Ｘ^-は上記と同じ意味を有する］
【００２８】
【化１４】

【００２９】
［式中、Ｙ^-はＰＦ₆ ^-、ＳｂＦ₆ ^-、ＡｓＦ₆ ^-又はＳｂＦ₅(ＯＨ)^-を表わす］
【００３０】
【化１５】

【００３１】
［式中、Ｘ^-は上記と同じ意味を有する］
【００３２】
【化１６】

【００３３】
［式中、Ｘ^-は上記と同じ意味を有する］
【００３４】
【化１７】

【００３５】
［式中、Ｘ^-は上記と同じ意味を有する］
【００３６】
【化１８】

【００３７】
［式中、Ｒ³は炭素原子数７〜１５のアラルキル基又は炭素原子数３〜９のアルケニル基、Ｒ⁴は炭素原子数１〜７の炭化水素基又はヒドロキシフェニル基、Ｒ⁵は酸素原子又は硫黄原子を含有していてもよい炭素原子数１〜５のアルキル基を示し、Ｘ^-は上記と同じ意味を有する］
【００３８】
【化１９】

【００３９】
［式中、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表わす］
【００４０】
【化２０】

【００４１】
［式中、Ｒ⁶及びＲ⁷は上記と同じ意味を有する］
【００４２】
【化２１】

【００４３】
光カチオン重合開始剤（Ｂ）の市販品としては、例えば、サイラキュアＵＶＩ−６９７０、同ＵＶＩ−６９９０（以上、いずれも米国ユニオンカーバイド社製）、イルガキュア２６４（チバガイギー社製）、ＣＩＴ−１６８２（日本曹達（株）製）等を挙げることができる。上記化合物中、毒性、汎用性の点からＰＦ₆ ^-をアニオンとする塩が好ましい。
【００４４】
上記の光カチオン重合開始剤（Ｂ）は、一般に、前記樹脂（Ａ）１００重量部（固形分基準）に対して、０.０１〜２０重量部、好ましくは０.０５〜１５重量部、さらに好ましくは０.１〜１０重量部の範囲内で使用することができる。
【００４５】
樹脂組成物：
本発明の樹脂組成物は、以上に述べた樹脂（Ａ）及び開始剤（Ｂ）を、必要に応じて溶剤又は分散媒の存在下に均一に混合することにより調製することができる。ここで使用しうる溶剤又は分散媒は、樹脂（Ａ）の製造に際して用いた重合溶媒又は他の溶媒であることができ、具体的には、例えば、ヘキサン、ヘプタン、オクタン等の炭化水素系溶剤；ジクロロメタン、クロロホルム等のハロゲン化炭化水素系溶剤；メタノール、エタノール、イソプロパノール等のアルコール系溶剤；ジエチルエーテル、ジプロピルエーテル、セロソルブ、ジエチレングリコールモノブチルエーテル等のエーテル系溶剤；アセトン、メチルエチルケトン、シクロヘキサノン等のケトン系溶剤；酢酸エチル、２−エチルヘキシルアセテート等のエステル系溶剤等を用いることができる。
【００４６】
また、本発明の樹脂組成物には、必要に応じてモノメリックオキセタン化合物、例えば、３−エチル−３−ヒドロキシメチルオキセタン、３−ブチル−３−ヒドロキシメチルオキセタン等の前記式（ＩＩ）の化合物を配合することができる。その配合量は、通常、樹脂（Ａ）１００重量部（固形分基準）に対して５０重量部以下、特に２０重量部以下であることが好ましい。
【００４７】
本発明の樹脂組成物には、さらに必要に応じて、ポリエポキシド、ポリオール等の反応性希釈剤を配合してもよい。
【００４８】
本発明の樹脂組成物は、例えば、被覆用組成物として好適に使用することができるが、その場合、本発明の樹脂組成物には、さらに必要に応じて、着色顔料、体質顔料、防錆顔料等の顔料；シリコーン、ポリアミド等の流動性調節剤、紫外線吸収剤、タレ止め剤、増粘剤などの各種添加剤を通常用いられている量で配合することもできる。
【００４９】
樹脂（Ａ）及び光カチオン重合開始剤を含んでなる本発明に従う被覆用組成物は、基材に塗布又は印刷した後、活性エネルギー線を照射することにより硬化させることができる。
【００５０】
その塗布または印刷の方法としては、例えば、スプレー塗装、刷毛塗装、ローラー塗装、浸漬塗装、スクリーン印刷等の通常の塗装又は印刷手段を用いることができる。塗装膜厚は乾燥膜厚で通常約１〜約１００ミクロンの範囲内が好ましい。
【００５１】
また、照射に用いうる活性エネルギー線としては、紫外線や電子線が包含される。紫外線照射は波長約２００〜約４００ｎｍで約１０〜約３,０００ｍｊ／ｃｍ²、特に５０〜１,０００ｍｊ／ｃｍ²の範囲内で行なうことができる。また、電子線照射は２〜３Ｍｒａｄの範囲内で行なうことができる。
【００５２】
本発明の樹脂組成物は、優れた活性エネルギー線硬化性を有しており、例えば、塗料、インキ、刷版材、フォトレジスト、封止材、表面処理剤等に使用することができる。
【００５３】
【実施例】
以下、実施例を挙げて、本発明を更に具体的に説明する。実施例における「部」及び「％」はそれぞれ重量基準である。
【００５４】
製造例１〜８及び比較製造例１〜２
撹拌機、冷却器及び滴下ロートを取り付けた３Ｌ４つ口フラスコにキシレン３５０部及びｎ−ブタノール１００部を加え、１００℃に加熱した後、滴下ロートから表１に示す組成のモノマー混合液にアゾビスイソブチロニトリル１５部を溶解させた溶液を３時間かけて滴下した。滴下後、１時間エージングを行ない、続いてアゾビスジメチルバレロニトリル５部を５０部のキシレンに溶解させた溶液を１時間かけて滴下した。反応後、得られた樹脂溶液を５Ｌの冷メタノール中に注ぎ、絹布で濾過後、減圧乾燥機で１昼夜乾燥して白色の樹脂粉末（Ａ−１）〜（Ａ−１０）を得た。得られた樹脂のゲルパーミュエーションクロマトグラフィ測定による数平均分子量及び１分子中の官能基の個数を併せて表１に示す。
【００５５】
【表１】

【００５６】
実施例１〜９及び比較例１〜２
製造例１〜８及び比較製造例１〜２で得られた樹脂粉末（Ａ−１）〜（Ａ−１０）１００重量部をポリエポキシド反応性希釈剤であるセロキサイド２０２１（ダイセル化学（株）社製、商標名）３０部に溶解させた樹脂溶液と、下記に示す光カチオン重合開始剤（Ｂ−１）又は（Ｂ−２）を表２に示す割合で配合して実施例１〜９及び比較例１〜２の活性エネルギー線硬化型塗料組成物を得た。
【００５７】
光カチオン重合開始剤（Ｂ−１）：サイラキュアＵＶＩ−６９７０（ユニオンカーバイド社製、商標名）
光カチオン重合開始剤（Ｂ−２）：イルガキュア２６４（チバガイギー社製、商標名）
実施例１〜９及び比較例１〜２の活性エネルギー線硬化型塗料組成物をガラス板上に乾燥膜厚が約３０ミクロンになるように流し塗りを行ない、高圧水銀灯を用い種々の紫外線照射量で紫外線照射を行ない、硬化被膜を得た。得られた硬化被膜面を３枚重ねのガーゼにキシレンをしみ込ませて１０往復こすった後の塗面を観察し、塗膜の傷付きや溶け落ちなどの異常が全くみられない最少の紫外線照射量（ｍｊ／ｃｍ²）を「最少紫外線照射量」として、表２に併せて示した。
【００５８】
【表２】

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel active energy ray-curable resin composition.
[0002]
[Prior art and its problems]
Active energy ray-curable resin compositions using cationic photopolymerization have the advantage of being unaffected by oxygen during curing, and have recently begun to be used in many applications including paint compositions. There was a drawback that the photosensitivity was poor as compared to radical polymerization of the active energy ray of the group. Attempts have been made to use an oxetane group as a cross-linking functional group in order to solve this drawback, but it cannot be said to be sufficient from the viewpoint of photosensitivity.
[0003]
[Problems to be solved by the invention]
As a result of intensive studies to eliminate the above-mentioned conventional drawbacks of the active energy ray-curable resin composition, the present inventors have improved the photosensitivity when an oxetane functional group and an epoxy group are used in combination as a cross-linking functional group. As a result, it has been found that the rate of photocationic polymerization is increased, and the present invention has been completed.
[0004]
According to the present invention,
(A) The following formula (I)
[0005]
Embedded image

[0006]
(In the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluorine atom, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, an aralkyl group, a furyl group, or a thienyl group).
An active energy ray-curable resin composition comprising: a resin having both an oxetane functional group and an epoxy group represented by the formula (B) and a cationic photopolymerization initiator (B) is provided.
Hereinafter, the resin composition of the present invention will be described in more detail.
[0007]
Resin (A) having both oxetane functional group and epoxy group in the same molecule:
The resin composition of the present invention comprises, as a main resin component, a resin (A) having both an oxetane functional group represented by the above formula (I) and an epoxy group in one molecule as a crosslinking functional group. Has characteristics.
[0008]
In the definition of R ¹ in the formula (I), the “C1-C6 alkyl group” may be linear or branched, such as methyl, ethyl, n-propyl, isopropyl, Examples include n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl and the like. The “C 1-6 fluoroalkyl group” is a group in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom, and examples thereof include fluoropropyl, fluorobutyl, trifluoropropyl and the like. The “aryl group” may be monocyclic or polycyclic, and the aromatic ring may be substituted with one or more alkyl groups having 1 to 6 carbon atoms, such as phenyl, toluyl , Xylyl, naphthyl and the like. The “aralkyl group” is an aryl-alkyl group in which the aryl moiety and the alkyl moiety have the above-mentioned meanings, and examples thereof include benzyl and phenethyl.
[0009]
R ¹ is particularly preferably an alkyl group having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms, such as methyl or ethyl.
[0010]
The oxetane functional group is bonded to the side chain or main chain of the resin (A) via a bond containing oxygen such as an ether bond, an ester bond, a urethane bond, or a hydrocarbon chain including one or more of these bonds. It is preferable.
[0011]
The oxetane functional group may be present in the resin (A) on an average of at least about 2 or more, preferably an average of about 2 to about 100, more preferably an average of about 2 to about 50. it can.
[0012]
On the other hand, the epoxy group is present in the resin (A) in an average of at least about 2 or more per molecule, preferably about 2 to about 100 on average, more preferably about 2 to about 50 on average. Can do.
[0013]
The resin (A) is preferably soluble in an organic solvent often used in the paint field, or is preferably dispersed or soluble in an aqueous medium. Generally, the resin (A) is about 300 to about 200,000, preferably about 500 to Those having a number average molecular weight of about 100,000, more preferably about 1,000 to about 50,000 are suitable.
[0014]
The type of the resin (A) is not particularly limited, and various resins such as acrylic, polyester, polyurethane, and polyether can be used. However, when the resin composition of the present invention is used as a paint, From the viewpoints of the weather resistance and durability of the coating film, an acrylic resin is particularly preferable.
[0015]
The acrylic resin having both the oxetane functional group of formula (I) and the epoxy group is, for example,
(A) an unsaturated monomer having an oxetane functional group of formula (I) at one end of the molecule and a radically polymerizable unsaturated group at the other end, and (b) an epoxy group-containing acrylic unsaturated monomer. It can be produced by copolymerizing with other copolymerizable radically polymerizable unsaturated monomers.
[0016]
As the oxetane functional group-containing unsaturated monomer (a), for example, the following formula:
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[0018]
In the formula, R ¹ has the same meaning as above.
A complementary functional group, such as an isocyanate group or a lower alkoxy group, which reacts with the hydroxyl group in the above formula (II) in a complementary manner but does not substantially react with the oxetane group. (For example, methoxy, ethoxy), a lower alkoxycarbonyl group (for example, methoxycarbonyl, ethoxycarbonyl), etc. at one end and a radically polymerizable unsaturated group, for example, an acryloyl group, a methacryloyl group, a vinyl group at the other end. It can be obtained by reacting with a saturated compound.
[0019]
The compound of the above formula (II), for example, 3-ethyl-3-hydroxymethyloxetane can be produced by reacting trimethylolpropane with diethyl carbonate to produce a hydroxyl group-containing cyclic carbonate and then decarboxylating. .
[0020]
Examples of the unsaturated compound that can be reacted with the compound of formula (II) include (meth) acrylic acid, methyl (meth) acrylate, isocyanate ethyl (meth) acrylate, m-isopropenyl-α, α. -Dimethylbenzyl isocyanate, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, methyl vinyl ether, ethyl vinyl ether and the like.
[0021]
Examples of the epoxy group-containing acrylic unsaturated monomer (b) include glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate.
[0022]
Examples of the radical polymerizable unsaturated monomer copolymerizable with the monomers (a) and (b) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. C ₁ -C ₂₄ alkyl or cycloalkyl esters of (meth) acrylic acid such as cyclohexyl (meth) acrylate; (meth) such as 2-hydroxypropyl (meth) acrylate and caprolactone-modified (meth) acrylic acid hydroxyethyl C ₂ -C ₈ hydroxyalkyl esters of acrylic acid; (meth) carboxyl group-containing unsaturated monomers such as acrylic acid; styrene, alpha-methyl styrene, aromatic vinyl compounds such as vinyl toluene; perfluorobutylethyl ( (Meth) acrylate, perfluoroi Fluorine-containing unsaturated monomers such as sononylethyl (meth) acrylate; polymerizable amides such as (meth) acrylamide; polymerizable nitriles such as (meth) acrylonitrile. These monomers can be used by appropriately selecting one type or two or more types according to the properties desired for the resin to be formed.
[0023]
The copolymerization of the monomers (a), (b) and (c) can be carried out by a method known per se, for example, a method such as solution polymerization, suspension polymerization, emulsion polymerization or bulk polymerization.
[0024]
Photocationic polymerization initiator (B):
The photocationic polymerization initiator (B) used in the present invention is a compound that generates cations by active energy rays and initiates cationic polymerization of oxetane functional groups and epoxy groups. For example, the following formulas (III) to (III) Mention may be made of hexafluoroantimonate salts, pentafluorohydroxyantimonate salts, hexafluorophosphate salts, hexafluoroarsenate salts and other photocationic polymerization initiators represented by XIV).
[0025]
Ar ₂ I ⁺ · X ⁻ (III)
[In the formula, Ar represents an aryl group such as a phenyl group, and X ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , or AsF ₆ ⁻ ]
Ar ₃ S ⁺ · X ⁻ (IV)
[Wherein Ar and X ⁻ have the same meaning as above]
[0026]
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[0027]
[Wherein R ² represents an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, n represents an integer of 0 to 3, and X ⁻ has the same meaning as described above]
[0028]
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[0029]
[Wherein Y ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ or SbF ₅ (OH) ⁻ ]
[0030]
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[0031]
[Wherein X ⁻ has the same meaning as above]
[0032]
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[0033]
[Wherein X ⁻ has the same meaning as above]
[0034]
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[0035]
[Wherein X ⁻ has the same meaning as above]
[0036]
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[0037]
[Wherein R ³ is an aralkyl group having 7 to 15 carbon atoms or an alkenyl group having 3 to 9 carbon atoms, R ⁴ is a hydrocarbon group or hydroxyphenyl group having 1 to 7 carbon atoms, and R ⁵ is an oxygen atom. Or an alkyl group having 1 to 5 carbon atoms which may contain a sulfur atom, and X ⁻ has the same meaning as described above.
[0038]
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[0039]
[Wherein R ⁶ and R ⁷ each independently represents an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms]
[0040]
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[0041]
[Wherein R ⁶ and R ⁷ have the same meaning as above]
[0042]
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[0043]
Commercially available products of the photocationic polymerization initiator (B) include, for example, Cyracure UVI-6970, UVI-6990 (all of which are manufactured by Union Carbide, Inc.), Irgacure 264 (Ciba Geigy), CIT-1682 (Japan). Soda Co., Ltd.). Among the above compounds, salts having PF ₆ ⁻ as an anion are preferable from the viewpoint of toxicity and versatility.
[0044]
The photocationic polymerization initiator (B) is generally 0.01 to 20 parts by weight, preferably 0.05 to 15 parts by weight, based on 100 parts by weight (based on solid content) of the resin (A). Preferably it can be used within the range of 0.1 to 10 parts by weight.
[0045]
Resin composition:
The resin composition of the present invention can be prepared by uniformly mixing the resin (A) and the initiator (B) described above in the presence of a solvent or a dispersion medium as necessary. The solvent or dispersion medium that can be used here can be the polymerization solvent or other solvent used in the production of the resin (A), and specifically, for example, hydrocarbon solvents such as hexane, heptane, and octane. Halogenated hydrocarbon solvents such as dichloromethane and chloroform; alcohol solvents such as methanol, ethanol and isopropanol; ether solvents such as diethyl ether, dipropyl ether, cellosolve and diethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone and cyclohexanone System solvents; ester solvents such as ethyl acetate and 2-ethylhexyl acetate can be used.
[0046]
In addition, the resin composition of the present invention includes a compound of the above formula (II) such as a monomeric oxetane compound, for example, 3-ethyl-3-hydroxymethyloxetane, 3-butyl-3-hydroxymethyloxetane, if necessary. Can be blended. The blending amount is usually preferably 50 parts by weight or less, particularly preferably 20 parts by weight or less, based on 100 parts by weight (based on solid content) of the resin (A).
[0047]
If necessary, the resin composition of the present invention may further contain a reactive diluent such as polyepoxide or polyol.
[0048]
The resin composition of the present invention can be suitably used, for example, as a coating composition. In that case, the resin composition of the present invention may further include a color pigment, an extender pigment, and a rust preventive, as necessary. Various additives such as pigments such as pigments; fluidity regulators such as silicone and polyamide, ultraviolet absorbers, sagging inhibitors, thickeners, etc., can be blended in the amounts usually used.
[0049]
The coating composition according to the present invention comprising the resin (A) and the cationic photopolymerization initiator can be cured by irradiating active energy rays after being applied or printed on the substrate.
[0050]
As the application or printing method, for example, ordinary coating or printing means such as spray coating, brush coating, roller coating, dip coating, and screen printing can be used. The coating film thickness is preferably in the range of about 1 to about 100 microns in terms of dry film thickness.
[0051]
Active energy rays that can be used for irradiation include ultraviolet rays and electron beams. The ultraviolet irradiation can be performed at a wavelength of about 200 to about 400 nm and in the range of about 10 to about 3,000 mj / cm ² , particularly 50 to 1,000 mj / cm ² . Electron beam irradiation can be performed within a range of 2 to 3 Mrad.
[0052]
The resin composition of the present invention has excellent active energy ray curability and can be used, for example, for paints, inks, printing plate materials, photoresists, sealing materials, surface treatment agents, and the like.
[0053]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “parts” and “%” are based on weight.
[0054]
Production Examples 1-8 and Comparative Production Examples 1-2
After adding 350 parts of xylene and 100 parts of n-butanol to a 3L four-necked flask equipped with a stirrer, a cooler and a dropping funnel and heating to 100 ° C., the monomer mixture of the composition shown in Table 1 is added from the dropping funnel to the monomer mixture. A solution in which 15 parts of isobutyronitrile was dissolved was dropped over 3 hours. After the dropping, aging was performed for 1 hour, and then a solution in which 5 parts of azobisdimethylvaleronitrile was dissolved in 50 parts of xylene was dropped over 1 hour. After the reaction, the obtained resin solution was poured into 5 L of cold methanol, filtered through silk cloth, and then dried for one day in a vacuum dryer to obtain white resin powders (A-1) to (A-10). Table 1 shows the number average molecular weight of the obtained resin measured by gel permeation chromatography and the number of functional groups in one molecule.
[0055]
[Table 1]

[0056]
Examples 1-9 and Comparative Examples 1-2
100 parts by weight of the resin powders (A-1) to (A-10) obtained in Production Examples 1 to 8 and Comparative Production Examples 1 and 2 are Celoxide 2021, which is a polyepoxide reactive diluent (manufactured by Daicel Chemical Industries, Ltd.). Example 1-9 and comparison which mix | blended the resin solution dissolved in 30 parts and the photocationic polymerization initiator (B-1) or (B-2) shown below in the ratio shown in Table 2 in 30 parts. The active energy ray-curable coating compositions of Examples 1 and 2 were obtained.
[0057]
Photocationic polymerization initiator (B-1): Cyracure UVI-6970 (trade name of Union Carbide)
Photocationic polymerization initiator (B-2): Irgacure 264 (Ciba Geigy, trade name)
The active energy ray-curable coating compositions of Examples 1 to 9 and Comparative Examples 1 and 2 were flow-coated on a glass plate so that the dry film thickness was about 30 microns, and various ultraviolet irradiation amounts using a high-pressure mercury lamp. UV irradiation was performed to obtain a cured coating. The cured film surface obtained is impregnated with xylene in three layers of gauze, and after 10 reciprocations, the coated surface is observed, and UV irradiation is minimized with no abnormalities such as scratches or burn-out of the film. The amount (mj / cm ² ) is shown in Table 2 as “minimum ultraviolet irradiation amount”.
[0058]
[Table 2]

Claims (10)

(A) The following formula (I)

(In the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluorine atom, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, an aralkyl group, a furyl group, or a thienyl group).
An active energy ray-curable resin composition comprising a resin having both an oxetane functional group and an epoxy group represented by the formula (B) and a cationic photopolymerization initiator. The composition according to claim 1, wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms. The composition according to claim 1, wherein the resin (A) has an average of 2 to 100 oxetane functional groups and an average of 2 to 100 epoxy groups per molecule. The composition according to claim 1, wherein the resin (A) is an acrylic resin having a number average molecular weight of about 300 to about 200,000. The cationic photopolymerization initiator is represented by the following formulas (III) to (XIV)
Ar ₂ I ⁺ · X ⁻ (III)
[In the formula, Ar represents an aryl group such as a phenyl group, and X ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , or AsF ₆ ⁻ ]
Ar ₃ S ⁺ · X ⁻ (IV)
[Wherein Ar and X ⁻ have the same meaning as above]

[Wherein R ² represents an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, n represents an integer of 0 to 3, and X ⁻ has the same meaning as described above]

[Wherein Y ⁻ represents PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ or SbF ₅ (OH) ⁻ ]

[Wherein X ⁻ has the same meaning as above]

[Wherein X ⁻ has the same meaning as above]

[Wherein X ⁻ has the same meaning as above]

[Wherein R ³ is an aralkyl group having 7 to 15 carbon atoms or an alkenyl group having 3 to 9 carbon atoms, R ⁴ is a hydrocarbon group or hydroxyphenyl group having 1 to 7 carbon atoms, and R ⁵ is an oxygen atom. Or an alkyl group having 1 to 5 carbon atoms which may contain a sulfur atom, and X ⁻ has the same meaning as described above.

[Wherein R ⁶ and R ⁷ each independently represents an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms]

[Wherein R ⁶ and R ⁷ have the same meaning as above]

The composition of Claim 1 selected from the compound shown by these. The composition of Claim 1 which contains a photocationic polymerization initiator (B) in the range of 0.01-20 weight part with respect to 100 weight part (solid content basis) of resin (A). The composition of Claim 6 which contains a photocationic polymerization initiator (B) in the range of 0.05-15 weight part with respect to 100 weight part (solid content basis) of resin (A). The composition of claim 1 further comprising a monooxetane compound. An active energy ray-curable coating composition comprising the composition according to claim 1. An article coated with the composition of claim 9.