JP4021347B2 - Photo-curable resin composition with excellent heat resistance - Google Patents

Description

式（Ｉ）中、ａは１または２であって、ａが１の時Ｒ_１は水素原子またはメチル

換基（構造）であり、ａが２の時は一方がメチル基かつ他方が水素原子、または、

数であり、ｂ＝３の場合、Ｒ_３は水素原子、メチル基またはエチル基であり、Ｒ_２は水素原子またはメチル基、ｎは０〜２０の整数であるが同時に０及び／又は４より大きくなることはなく、ｎの総和は４〜２０、ｎの平均値は１〜４である。
【００１２】
Ａは下記一般式（ＩＩ）で表される３価の置換基である。

【００１３】
式（ＩＩ）中、Ｙは炭素数４〜２０のアルキル基あるいは下記式群（ＩＩＩ）から選ばれる置換基である。

式（ＩＩＩ）中、Ｒ_４はそれぞれ独立に水素原子、低級アルキル基であり、ｅ＝０〜１０、ｆ＝０〜４、ｇ＝０〜４である。
で表されるウレタン化アクリル化合物。
【００１４】
（ｉｉ）前記のウレタン化アクリル化合物以外のラジカル重合性化合物および
（ｉｉｉ）光重合開始剤を含有する光硬化性樹脂組成物であって、前記ウレタン化アクリル化合物：前記ラジカル重合性化合物の含有割合が重量比で８０：２０〜１０：９０の範囲であることを特徴とする光硬化性樹脂組成物であり、
【００１５】
▲２▼上記一般式（Ｉ）において、Ａが下記式群（ＩＶ）から選ばれる少なくとも１種のトリイソシアネート残基から構成されるウレタン化アクリル化合物を用いて成ることを特徴とする▲１▼記載の光硬化性樹脂組成物であり、

【００１６】
▲３▼上記一般式（Ｉ）で表されるウレタン化アクリル化合物一分子において、少なくとも下記式（Ｖ）で表される置換基を６個以上を有して成ることを特徴とする▲１▼または▲２▼の光硬化性樹脂組成物であり、

置換基（構造）である。
【００１７】
▲４▼ウレタン化アクリル化合物（Ｉ）およびラジカル重合性化合物の合計重量に基づいて、光重合開始剤の含有割合が０．１〜１０重量％である▲１▼〜▲３▼記載の光硬化性樹脂組成物であり、
▲５▼固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤を更に含有する▲１▼〜▲４▼記載の光硬化性樹脂組成物であり、
▲６▼固体微粒子およびウイスカーの両方を含有する▲５▼記載の光硬化性樹脂組成物であり、
▲７▼固体微粒子が光の乱反射の少ない滑らかな表面を有する球状固体微粒子である▲５▼の光硬化性樹脂組成物であり、
▲８▼径が０．０１〜１μｍ、長さが１〜７０μｍ、およびアスペクト比が５〜１００のウイスカーを用いる▲５▼〜▲７▼のいずれかの光硬化性樹脂組成物であり、
▲９▼固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤がシラン系カップリング剤で処理されている▲５▼〜▲８▼のいずれか１項の光硬化性樹脂組成物であり、
▲１０▼固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤の合計含有量が、それらを含有させる前の光硬化性樹脂組成物の容量に基づいて、３〜７０容量％である▲５▼〜▲９▼のいずれかの光硬化性樹脂組成物であり、
▲１１▼光学的立体造形用樹脂組成物である▲１▼〜▲１０▼のいずれかの光硬化性樹脂組成物であり、
▲１２▼▲１▼〜▲１１▼のいずれか１項の光硬化性樹脂組成物を用いて、光学的立体造形法によって立体造形物を製造する方法であり、
【００１８】
▲１３▼（ｉ）下記の一般式（Ｉ）；

中、ａは１または２であって、ａが１の時Ｒ_１は水素原子またはメチル基、Ｘは

造）であり、ａが２の時は一方がメチル基かつ他方が水素原子、または、

数であり、ｂ＝３の場合、Ｒ_３は水素原子、メチル基またはエチル基であり、Ｒ_２は水素原子またはメチル基、ｎは０〜２０の整数であるが同時に０及び／又は４より大きくなることはなく、ｎの総、和は４〜２０、ｎの平均値は１〜４である、Ａは下記一般式（１１）で表される３価の置換基である。
【００１９】

式（ＩＩ）中、Ｙは炭素数４〜２０のアルキル基あるいは下記式群（ＩＩＩ）から選ばれる置換基である。
【００２０】

式（ＩＩＩ）中、Ｒ_４はそれぞれ独立に水素原子、低級アルキル基であり、ｅ＝０〜１０、ｆ＝０〜４、ｇ＝０〜４である。
で表されるウレタン化アクリル化合物である。
【００２１】
【発明の実施の形態】
以下に本発明について詳細に説明する。まず、本発明の光硬化性樹脂組成物で用いる上記の一般式（Ｉ）で表されるウレタン化アクリル化合物（Ｉ）について説明する。上記の一般式（Ｉ）で表されるウレタン化アクリル化合物（Ｉ）において、

【００２２】

様に表され、うちの一方または両方の基における基Ｒ^１がメチル基であることが必要である。ウレタン化アクリル化合物（Ｉ）においてａが２のときに２個の基；

刺激性のあるグリセリンジアクリレートを経由しなければならず、実質的に使用できず、好ましくない。
【００２３】
また、ウレタン化アクリル化合物（Ｉ）において、基Ａは下記一般式（ＩＩ）で表される３価の置換基であり、

更にＹは炭素数４〜２０のアルキル基あるいは下記式群（ＩＩＩ）から選ばれる置換基であることが望ましい。
【００２４】

Ｒ_４はそれぞれ独立に水素原子、低級アルキル基であり、ｅ＝０〜１０、ｆ＝０〜４、ｇ＝０〜４である。
【００２５】
具体的には、Ｙがイソホロン基、トリレン基、４，４’−ジフェニルメタン基、ナフチレン基、キシリレン基、フェニレン基、３，３’−ジクロロ−４，４’−フェニルメタン基、トルイレン基、ヘキサメチレン基、４，４’−ジシクロヘキシルメタン基、水添化キシリレン基、水添化ジフェニルメタン基、トリフェニレンメタン基、テトラメチルキシレン基などを挙げることができる。
その中でも、基Ｙがイソホロン基、トリレン基および／またはキシリレン基であるのがより好ましく、更にはイソホロン基であることがより好ましい。
即ち、イソホロンジイソシアネートの３量体から構成されるイソシアヌレート構造が好ましい。
つまり、イソホロンジイソシアネートの３量体は通常４つの異性体が存在することになるが、いずれの構造でもかまわない。具体的には下記式群（ＩＶ）から選ばれる少なくとも１種のトリイソシアネート残基から構成されるウレタン化アクリル化合物が好ましい。
【００２６】

また、これら上記４つの構造から選択された場合のトリイソシアネート化合物を下記式（ＶＩ）その残基を下記式（ＶＩＩ）の様に表すことで定義する。
【００２７】

上記に説明した基Ａは、必要に応じて単独で用いてもまたは２種以上併用しても何ら問題はない。
Ｒ_２は水素原子及び／またはメチル基であり、すなわち上記式でＲ_２を含む（）内に示される構造は、エチレングリコール残基及び／又はプロピレングリコール残基である。
ｎは０〜２０の整数であるが、全てのｎが同時に０になることは無い。また、全てのｎが同時に４より大きくなることはなく、ｎの総和は４〜２０、ｎの平均値は１〜４である。
ここ述べるｎの平均値とは、エチレングリコール残基及び／又はプロピレングリコール残基の繰り返し単位数の総和をｂで除した値である。
【００２８】
ｎの平均値が４よりも大きいと、上記した他のラジカル重合性化合物として適当なものを選択したとしても、光硬化性樹脂組成物を用いて得られる光硬化物の熱変形温度が充分に高くならず、耐熱性が所望の水準に達しない。一方、ｎの平均値が１より小さいとき、あるいはｎが全て０のとき、すなわちウレタン化アクリル化合物（Ｉ）がエチレンオキサイド基またはプロピレンオキサイド基をほとんど持たない場合は、耐熱性の向上は認められるものの、光硬化時の体積収縮が大きくて目的とする成形品や立体造形物などを高い寸法精度で製造することができず、しかもウレタン化アクリル化合物を合成する際にゲル化が生じやすくなり、また得られるウレタン化アクリル化合物の粘度が異常に高くなって、本発明の光硬化性樹脂組成物に用いることができなくなる。
【００２９】
好ましいエチレングリコール残基、及び／又はプロピレングリコール残基を以下に述べると、
エチレングリコール残基は式：−（ＣＨ_２ＣＨ_２Ｏ）ｎ１−（式中ｎ１は１〜４の整数を示す）で表される（ポリ）エチレンオキサイド基、式：−［ＣＨ_２ＣＨ（ＣＨ_３）Ｏ］ｎ２−（式中ｎ２は１〜４の整数を示す）で表される（ポリ）プロピレンオキサイド基または式：−（ＣＨ_２ＣＨ_２Ｏ）ｎ３［ＣＨ_２ＣＨ（ＣＨ_３）Ｏ］ ｎ４−（式中ｎ３およびｎ４はそれぞれ１〜３の整数であってｎ３とｎ４の合計が２〜４である）で表される（ポリ）エチレンオキサイドプロピレンオキサイド基である。
より好ましくは、（ポリ）エチレンオキサイド基または（ポリ）プロピレンオキサイド基ではｎ１またはｎ２がそれぞれ１〜３の整数であるのが好ましい。あるいは、前記の式で表される（ポリ）エチレンオキサイドプロピレンオキサイド基では、ｎ３とｎ４の合計が２または３であるのが好ましい。
更に好ましくは、−［（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ］ｎ２−（式中ｎ２は好ましくは１〜３、より好ましくは１〜２）で表される（ポリ）プロピレンオキサイド基である場合は、熱変形温度がより高くて耐熱性がより優れており、硬化時の体積収縮がより小さく、しかも比較的低粘度の光硬化性樹脂組成物を得ることができるので好ましい。
上記式中、ｂは３または４の整数である。ｂが３の場合、Ｒ_３は水素原子またはエチル基であることが好ましい。
【００３０】
上記一般式（Ｉ）で表されるウレタン化アクリル化合物一分子において、少なくとも下記式（Ｖ）で表される置換基を６個以上を有している。

【００３１】
式中、Ｒ_１は上記式（Ｉ）と同義である。Ｘは下記式郡（ＶＩＩＩ）から選択される少なくとも１種である。

式（Ｖ）で表される置換基が６より小さいと、光硬化性樹脂組成物を用いて得られる光硬化物の熱変形温度が充分に高くならず、耐熱性が所望の水準に達しない。
式（Ｖ）で表される置換基数の上限には特に制限はないが、実際上は１６個までである。
【００３２】
そして、本発明の光硬化性樹脂組成物は、上記したウレタン化アクリル化合物（Ｉ）と共に、ウレタン化アクリル化合物（Ｉ）以外のラジカル重合性化合物（他のラジカル重合性化合物）（以下単に「ラジカル重合性化合物」ということがある）を含有する。ラジカル重合性化合物としては、光照射を行った際にウレタン化アクリル化合物（Ｉ）と反応して、またラジカル重合性化合物同士が反応して硬化物を形成することのできる炭素−炭素間不飽和結合を有するラジカル重合性化合物であればいずれも用いることが可能であるが、アクリル系化合物、アリル系化合物および／またはビニルラクタム類が好ましく用いられる。また、ラジカル重合性化合物は単官能性化合物または多官能性化合物のいずれであってもよく、或いは単官能性化合物と多官能性化合物の両方を併用してもよい。さらに、ラジカル重合性化合物は低分子量のモノマーであっても、オリゴマーであっても、また場合によってはある程度分子量の大きいものであってもよい。そして、本発明の光硬化性樹脂組成物は、ラジカル重合性化合物として１種類のラジカル重合性化合物のみを含有していてもまたは２種以上のラジカル重合性化合物を含有していてもよい。
【００３３】
限定されるものではないが、本発明の光硬化性樹脂組成物でラジカル重合性化合物として用い得るラジカル重合性化合物の例としては、イソボルニル（メタ）アクリレート、ボルニル（メタ）メタアクリレート、ジシクロペンテニル（メタ）アクリレート、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、（ポリ）プロピレングリコールモノ（メタ）アクリレート、ｔ−ブチル（メタ）アクリレートなどの（メタ）アクリレート類、モルホリン（メタ）アクリルアミドなどの（メタ）アクリルアミド類、Ｎ−ビニルカプロラクトン、スチレンなどの単官能性ラジカル重合性化合物；トリメチロープロパントリ（メタ）アクリレート、エチレンオキサイド変性トリメチロールプロパントリ（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、ジエチレングリコール（メタ）アクリレート、トリエチレングリコール（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、ポリエチレングリコール（メタ）アクリレート、１，４−ブタンジオールジ（メタ）アクリレート、１，６−ヘキサンジオールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ジシクロペンテニルジ（メタ）アクリレート、ジアリルフタレート、ジアリルフマレート、エチレンオキサイド変性ビスフェノールＡジアクリレートなどの多官能性ラジカル重合性化合物を挙げることができる。
【００３４】
また、上記したラジカル重合性化合物以外にも、光学的立体造形用樹脂組成物などで従来から用いられているエポキシ化合物、ウレタン化アクリル化合物（Ｉ）以外のウレタン化アクリル化合物、エポキシ（メタ）アクリレート化合物、他のエステル（メタ）アクリレートなどをラジカル重合性化合物として用いることができる。
本発明の光硬化性樹脂組成物では、上記したラジカル重合性化合物を単独で用いてもまたは２種以上併用してもよい。そして、上記した種々のラジカル重合性化合物のうちでも、本発明の光硬化性樹脂組成物では、モルホリン（メタ）アクリルアミド、ジシクロペンテニルジ（メタ）アクリレート、Ｎ−ビニルカプロラクタムがより好ましく用いられ、その場合には、光で硬化した際に、体積収縮率がより小さくて寸法精度により優れ、熱変形温度が高くて耐熱性に優れ、しかも透明性、剛性に優れる成形品や立体造形物、更にはその他の硬化物にすることのできる光硬化性樹脂組成物が得られる。
【００３５】
そして、本発明の光硬化性樹脂組成物では、ウレタン化アクリル化合物（Ｉ）：ラジカル重合性化合物の含有割合が、重量比で、８０：２０〜１０：９０であることが必要であり、６５：３５〜２５：７５であるのが好ましく、６０：４０〜３５：６５であるのがより好ましい。光硬化性樹脂組成物において、ウレタン化アクリル化合物（Ｉ）の割合がウレタン化アクリル化合物（Ｉ）とラジカル重合性化合物の合計重量に基づいて１０重量％未満であると光で硬化した際に耐熱性および剛性に優れる成形品や立体造形物などの硬化物が得られなくなり、一方８０重量％を超えると光硬化時の体積収縮率が大きくなって寸法精度が低下し、しかも光硬化性樹脂組成物の粘度が高くなり過ぎて、取り扱い性、成形性、造形性が低下し、特に光学的立体造形法で用いる場合に目的とする立体造形物を円滑に製造できなくなる。
【００３６】
さらに、本発明の光硬化性樹脂組成物は、上記したウレタン化アクリル化合物（Ｉ）および他のラジカル重合性化合物と共に、光重合開始剤を含有している。光重合開始剤としては光硬化性樹脂組成物において従来から用いられている光ラジカル重合開始剤であればいずれも使用でき特に制限されない。限定されるものではないが、本発明の光硬化性樹脂で用い得る光重合開始剤の例としては、２，２−ジメトキシ−２−フェニルアセトフェノン、１−ヒドロキシシクロヘキシルフェニルケトン、ジエトキシアセトフェノン、アセトフェノン、３−メチルアセトフェノン、２−ヒドロキシメチル−１−フェニルプロパン−１−オン、４’−イソプロピル−２−ヒドロキシ−２−プロピオフェノン、２−ヒドロキシ−２−メチル−プロピオフェノン、ｐ−ジメチルアミノアセトフェノン、ｐ−ｔ−ブチルジクロロアセトフェノン、ｐ−ｔ−ブチルトリクロロアセトフェノン、ｐ−アジドベンザルアセトフェノン、１−ヒドロキシシクロヘキシルフェニルケトノ、ベンゾフェノン、ｏ−ベンゾイル安息香酸メチル、ミヒラースケトン、４，４’−ビスジエチルアミノベンゾフェノン、キサントン、フルオレノン、フルオレン、ベンズアルデヒド、アントラキノン、トリフェニルアミン、カルバゾールなどを挙げることができる。
【００３７】
また、ラジカル重合性化合物として、ラジカル重合性の基と共にエポキシ基などのカチオン重合性の基を有する化合物を用いる場合は、上記した光ラジカル重合開始剤と共に光カチオン重合開始剤を併用してもよく、その場合の光カチオン重合開始剤の種類も特に制限されず、従来既知のものを使用することができる。光重合開始剤の使用量は、ウレタン化アクリル化合物（Ｉ）およびラジカル重合性化合物の種類、光重合開始剤の種類などに応じて変わり得るが、一般に、ウレタン化アクリル化合物（Ｉ）およびラジカル重合性化合物の合計重量に基づいて、０．１〜１０重量％であるのが好ましく、１〜５重量％であるのがより好ましい。
【００３８】
そして、本発明は、上記した光硬化性樹脂組成物中に固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤をさらに含有させてなる光硬化性樹脂組成物を本発明の範囲に包含する。固体微粒子およびウイスカーから選ばれる充填剤を含有する本発明の光硬化性樹脂組成物では、その光硬化時の体積収縮が一層低減されて、寸法精度に一層優れる成形品や造形物を得ることができる。しかも、固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤を含有する光硬化性樹脂組成物を光硬化して得られる成形品および造形物などは、その良好な機械的特性を保ちながら、極めて高い熱変形温度を有しており、ものによっては熱変形温度が２００℃を超えるものも得られ、耐熱性が一層優れたものとなる。
【００３９】
本発明の光硬化性樹脂組成物は、固体微粒子およびウイスカーから選ばれる充填剤のうちの１種類のみを含有していても、または２種以上を含有していてもよい。すなわち、本発明の光硬化性樹脂組成物は、１種または２種以上の固体微粒子のみを含有していても、１種または２種以上のウイスカーのみを含有していても、或いは１種または２種以上の固体微粒子と１種または２種以上のウイスカーの両方を含有していてもよい。そして、本発明の光硬化性樹脂組成物が固体微粒子とウイスカーの両方を含有する（すなわち１種または２種以上の固体微粒子と１種または２種以上のウイスカーとを含有する）場合には、光硬化時の体積収縮が一層小さくなり、しかも光硬化物の熱変形温度が極めて高くなり、寸法精度および耐熱性に一層優れる成形品や造形物などの光硬化物を得ることができる。
【００４０】
光硬化性樹脂組成物における固体微粒子およびウイスカーから選ばれる充填剤の含有量（２種以上を含有する場合はその合計含有量）は、固体微粒子やウイスカーの種類や形態などに応じて調節し得るが、一般には、固体微粒子および／またはウイスカーを含有させる前の光硬化性樹脂組成物の容量に基づいて、３〜７０容量％であるのが好ましく、２０〜６５容量％であるのがより好ましく、３０〜６０容量％であるのが更に好ましい。特に、本発明の光硬化性樹脂組成物がウイスカーを含有せずに固体微粒子のみを含有する場合は、固体微粒子の含有量を、それを含有させる前の光硬化性樹脂組成物の容量に基づいて３〜７０容量％とするのが好ましい。また、本発明の光硬化性樹脂組成物が固体微粒子を含有せずにウイスカーのみを含有する場合は、ウイスカーの含有量を、それを含有させる前の光硬化性樹脂組成物の容量に基づいて３〜３０容量％とするのが好ましい。光硬化性樹脂組成物中における固体微粒子およびウイスカーの含有量を上記した範囲にすることによって、寸法精度および耐熱性に一層優れる成形品や造形物が得られるようになる。一方、固体微粒子およびウイスカーの含有量が上記した上限範囲を超えると、光硬化性樹脂組成物の粘度が高くなり過ぎて、取り扱い性、光硬化時の操作性などが不良になるので注意を要する。
【００４１】
光硬化性樹脂組成物中に含有させる固体微粒子としては、滑らかな表面を有していて光照射時（エネルギー線照射時）に乱反射を生じにくく、しかも光硬化して得られる成形品や造形物などの光硬化物が使用される温度で分解や変質などの生じないような無機固体微粒子および有機重合体固体微粒子が好ましく用いられる。特に、固体微粒子として、下記の数式（１）で表される真球度の相対標準偏差値が０．５以下であるような、滑らかな球状を有する固体微粒子、特に真球状の固体微粒子を使用するのが好ましい。前記した相対標準偏差値が０．５以下である固体微粒子を用いた場合には、光硬化性樹脂組成物を光硬化させる際に照射光（照射エネルギー線）が固体微粒子によって乱反射させるのが防止されて光硬化を均一に行われ、寸法精度により優れる光硬化物を得ることができ、しかも光硬化性樹脂組成物の過度の粘度上昇が防止される。
【００４２】
また、固体微粒子は、その平均粒径が０．１〜７０μｍであるのが好ましく、０．２〜６０μｍであるのがより好ましく、１〜５０μｍであるのが更に好ましい。固体微粒子の平均粒径が０．１μｍ未満であると光硬化性樹脂組成物の粘度が過度に高くなり易く、一方７０μｍを超えると照射時に活性エネルギーの散乱を生じて成形品や造形物などの光硬化物の寸法精度が低いものになり易い。また、固体微粒子は透明なものであっても、または不透明なものであってもよく、目的とする成形品や造形物の種類や用途などに応じて選択すればよい。耐熱性の向上をはかりながら、透明性にも優れる光硬化物を得るためには、固体微粒子をサブミクロンの極めて小さな微粒子状にして、適当な表面処理を施して光硬化性樹脂組成物中に安定に分散せしめ、光硬化性樹脂組成物の粘度の上昇を抑制するようにすることも可能である。
【００４３】
本発明で好ましく用い得る固体微粒子としては、例えば、ガラスビーズ、タルク微粒子、酸化ケイ素微粒子などの無機固体微粒子；架橋ポリスチレン系微粒子、架橋型ポリメタクリレート系微粒子、ポリエチレン系微粒子、ポリプロピレン系微粒子などを挙げることができ、これらの固体微粒子は単独で使用しても、２種以上を併用しても、またはウイスカーと併用してもよい。
また、固体微粒子として、アミノシラン、エポキシシラン、アクリルシランなどのシラン系カップリング剤の１種または２種以上を用いて処理したものを用いると、光硬化して得られる硬化物の機械的強度が向上する場合が多く好ましい。シランカップリング剤処理を施したポリエチレン系固体微粒子および／またはポリプロピレン系固体微粒子を光硬化性樹脂組成物中に含有させる場合は、アクリル酸系化合物を１〜１０重量％程度共重合させたポリエチレン系固体微粒子および／またはポリプロピレン系固体微粒子を用いるとシランカップリング剤との親和性が高くなるので好ましい。
【００４４】
また、光硬化性樹脂組成物中にウイスカーを含有させる場合は、径が０．０１〜１μｍ、長さが１〜７０μｍおよびアスペクト比が５〜１００であるウイスカーを用いるのが好ましく、径が０．０３〜１μｍ、長さが５〜５０μｍおよびアスペクト比が１０〜９０のであるウイスカーを用いるのがより好ましく、径が０．０５〜１μｍ、長さが５〜３０μｍおよびアスペクト比が１０〜８０のであるウイスカーを用いるのが更に好ましい。
ウイスカーのアスペクト比が５未満の場合は、ウイスカーを含有させたことによる機械的特性の向上効果、体積収縮の低減効果などが得られにくくなり、しかも光硬化性樹脂組成物の粘度の上昇を招き易い。一方、ウイスカーのアスペクト比が大きくなれば機械的強度の教条および体積収縮の低減効果が期待されるが、アスペクト比があまり大きくなると光硬化性樹脂組成物の粘度上昇、流体弾性の上昇などを生じて、造形操作などが困難となったり、得られる光硬化物の寸法精度の低下、特に光硬化物における側面の寸法精度の低下などを生じ易くなるので、アスペクト比が１００以下であるのが好ましい。
【００４５】
本発明で好ましく用い得るウイスカーとしては、例えば、ホウ酸アルミニウム系化合物、水酸化硫酸マグネシウム系化合物、酸化アルミニウム、酸化チタン系化合物、酸化珪素系化合物などよりなるウイスカーを挙げることができ、これらのウイスカーは単独で使用しても、２種以上を併用しても、または上記した固体微粒子と併用してもよい。前記したもののうちでも、ホウ酸アルミニウム系化合物のウイスカーが好ましく用いられる。また、ウイスカーを、アミノシラン、エポキシシラン、アクリルシランなどのシラン系カップリング剤のうちの１種または２種以上で処理しておくと、光硬化して得られる硬化物の機械的強度が向上する場合が多く好ましい。
【００４６】
本発明の光硬化性樹脂組成物は、上記した成分以外にも、必要に応じて、レベリング剤、界面活性剤、有機高分子改質剤、有機可塑剤などを含有していてもよい。
本発明の光硬化性樹脂組成物の粘度は、用途や使用態様などに応じて調節し得るが、一般に、回転式Ｂ型粘度計を用いて測定したときに、常温（２５℃）において、その粘度が１００〜１０００００センチポイズ（ｃｐ）程度であるのが取り扱い性、成形性、立体造形性などの点から好ましく、３００〜５００００ｃｐ程度であるのがより好ましい。特に、本発明の光硬化性樹脂組成物を光学的立体造形に用いる場合は、上記した常温における粘度を３００〜５０００ｃｐの範囲にしておくのが、光学的に立体造形物を製造する際の取り扱い性が良好になり、しかも目的とする立体造形物を高い寸法精度で円滑に製造することができる点から望ましい。光硬化性樹脂組成物の粘度の調節は、ウレタン化アクリル化合物（Ｉ）およびラジカル重合性化合物の種類の選択、それらの配合割合の調節などによって行うことができる。
【００４７】
本発明の光硬化性樹脂組成物は、光を遮断し得る状態に保存した場合には、通常、１０〜４０℃の温度で、約６〜１８ケ月の長期に亙って、その変性や重合を防止しながら良好な光硬化性能を保ちながら保存することができる。
限定されるものではないが、本発明の光硬化性樹脂組成物で用い得るウレタン化アクリル化合物（Ｉ）の例としては、次のものを挙げることができる。
【００４８】

１であるウレタン化アクリル化合物であって、１個の炭素原を中心としてＡ基を

しているウレタン化アクリル化合物。
【００４９】

１、Ｒ_３はエチル基であるウレタン化アクリル化合物でであって、１個の炭素原子を中心としてその炭素原子（すなわち残りの基Ｒ_３が結合している炭素原子）

るウレタン化アクリル化合物。
【００５０】

３、Ｒ_３はエチル基であるウレタン化アクリル化合物であって、１個の炭素原子を中心としてその炭素原子（すなわち残りの基Ｒ_３が結合している炭素原子）に

ウレタン化アクリル化合物。
【００５１】

１であるウレタン化アクリル化合物であって、１個の炭素原子を中心としてその炭素原子（すなわち残りの基Ｒ_３が結合している炭素原子）に対してＡ基を経て

化合物。
本発明の光硬化性樹脂組成物は、その特性、特に光で硬化した際に体積収縮率が小さくて寸法精度に優れ、しかも高い熱変形温度を有していて耐熱性に優れ、かつ透明性に優れる成形品、立体造形物、その他の硬化物が得られるという特性を活かして種々の用途に使用することができ、例えば、光学的立体造形法による立体造形物の製造、流延成形法や注型などによる膜状物や型物などの各種成形品の製造、被覆用などに用いることができる。
【００５２】
そのうちでも、本発明の光硬化性樹脂組成物は、上記した光学的立体造形法で用いるのに適しており、その場合には、光硬化時の体積収縮率を小さく保ちながら、寸法精度に優れ且つ耐熱性、剛性および透明性に優れる立体造形物を円滑に製造することができる。本発明の光硬化性樹脂組成物を用いて光学的立体造形を行うに当たっては、従来既知の光学的立体造形方法および装置のいずれもが使用できる。そのうちでも、本発明では、樹脂を硬化させるための光エネルギーとして、Ａｒレーザー、Ｈｅ−Ｃｄレーザー、キセノンランプ、メタルハライドランプ、水銀灯、蛍光灯などからは発生される活性エネルギー光線を用いるのが好ましく、レーザー光線が特に好ましく用いられる。活性エネルギー光線としてレーザー光線を用いた場合には、エネルギーレベルを高めて造形時間を短縮することが可能であり、しかもレーザー光線の良好な集光性を利用して、造形精度の高い立体造形物を得ることができる。
【００５３】
上記したように、本発明の光硬化性樹脂組成物を用いて光学的立体造形を行うに当たっては、従来既知の方法や従来既知の光造形システム装置のいずれもが採用でき特に制限されないが、本発明で好ましく用いられる光学的立体造形法の代表例としては、光エネルギー吸収剤を含有する液状の光硬化性樹脂組成物に所望のパターンを有する硬化層が得られるように活性エネルギー光線を選択的に照射して硬化層を形成し、次いでその硬化層に未硬化液状の光硬化性樹脂組成物を供給し、同様に活性エネルギー光線を照射して前記の硬化層と連続した硬化層を新たに形成する積層する操作を繰り返すことによって最終的に目的とする立体的造形物を得る方法を挙げることができる。そして、それによって得られる立体造形物はそのまま用いても、また場合によっては更に光照射によるポストキュアや熱によるポストキュアなどを行って、その力学的特性や形状安定性などを一層高いものとしてから使用するようにしてもよい。
【００５４】
その際に立体造形物の構造、形状、サイズなどは特に制限されず、各々の用途に応じて決めることができる。そして、本発明の光学的立体造形法の代表的な応用分野としては、設計の途中で外観デザインを検証するためのモデル、部品の機能性をチェックするためのモデル、鋳型を制作するための樹脂型、金型を制作するためのベースモデル、試作金型用の直接型などの作製などを挙げることができる。より具体的には、精密部品、電気・電子部品、家具、建築構造物、自動車用部品、各種容器類、鋳物、金型、母型などのためのモデルや加工用モデルなどの製作を挙げることができる。特にその良好な耐熱性および透明性という特性を活かして、高温部品の試作、例えば複雑な熱媒回路の設計、複雑な構造に用いる熱媒挙動の解析企画用の部品の製造などに極めて有効に使用することができる。
【００５５】
【実施例】
以下で実施例等によって本発明について具体的に説明するが、本発明は以下の例によって何ら限定されない。
《合成例１》
〔ウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物を含む反応生成物の製造〕
（１−１）アクリル酸ダイマー（東亜合成株式会社製アロニックスＭ−５６００）１８７．２重量部及びグリシジルメタクリレート１４２重量部を四つ口フラスコに入れ、触媒としてトリエチルアミンを３３重量部、重合禁止剤としてメチルヒドロキノン０．２８重量部を添加し８０〜８５℃にて攪拌しながら５時間反応を行った。
【００５６】
得られた反応生成物にトルエン４２０重量部を加え１５重量％苛性ソーダ水溶液８８重量部で洗浄し次いで水１００ミリリットルで洗浄を行った。次に１Ｎ塩酸３００ミリリットルで洗浄しその後水１００ミリリットルで中性になるまで洗浄を繰り返した。次に硫酸ナトリウムを用いて乾燥し減圧下で溶剤を除去し下記の化学式（ＩＸ）で表わされるグリセリンのアクリレートメタクリレート化合物を得た。
【００５７】

（１−２）攪拌機、温度調節器、温度計及び凝縮器を備えた内容量１Ｌの三つ口フラスコにイソホロンジイソシアネート・イソシアヌレート・アダクト体（ＶＥＳＴＡＮＡＴＴ−１８９０／１００（デグサ・ヒュルスジャパン））２６６．４重量部、モルホリンアクリルアミド２２７．９重量部、及びジブチル錫ジラウレート０．７重量部を仕込み、均一に溶解するまで攪拌した。
【００５８】
（１−３）上記（１）で得られたグリセリンのアクリレートメタアクリレート化合物２２８．８重量部にメチルヒドロキノン０．４重量部を均一に混合溶解させた液を上記（１−２）の内容物に滴下混合して８０〜９０℃で２時間攪拌した。
【００５９】
（１−４）次いで、別の滴下ロートに仕込んだペンタエリスリトールのプロピレンオキサイド４モル付加物（ペンタエリスリトールの水酸基にプロピレンオキサイドをそれぞれ１モル付加したもの）３６．６重量部を添加しフラスコ内容物を８０〜９０℃で４時間反応させてウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物（モルホリンアクリルアミド）を含む反応生成物を製造した。
【００６０】
（１−５）その結果得られた反応生成物は無色で常温（２５℃）で粘稠な液状を呈していた。
この合成例１で得られた反応生成物中に含まれるウレタン化アクリル化合物（Ｉ）

１であるウレタン化アクリル化合物である。
【００６１】
《合成例２》
〔ウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物を含む反応生成物の製造〕
（２−１）攪拌機、温度調節器、温度計及び凝縮器を備えた内容量１Ｌの三つ口フラスコにイソホロンジイソシアネート・イソシアヌレート・アダクト体（ＶＥＳＴＡＮＡＴＴ−１８９０／１００（デグサ・ヒュルスジャパン））１９９．８重量部、モルホリンアクリルアミド１７０．６重量部、及びジブチル錫ジラウレート０．７重量部を仕込み、均一に溶解するまで攪拌した。
【００６２】
（２−２）合成例１の（１−１）で得られたグリセリンのアクリレートメタアクリレート化合物１７１．６重量部にメチルヒドロキノン０．４重量部を加え均一に混合溶解させた液を上記（２−１）の内容物に滴下混合して８０〜９０℃で２時間攪拌した。
【００６３】
（２−３）次いで、別の滴下ロートに仕込んだトリメチロールプロパンのエチレンオキサイド３モル付加物（トリメチロールプロパンの水酸基にエチレンオキサイドをそれぞれ１モル付加したもの）２６．６重量部を滴下し、８０〜９０℃で４時間反応させてウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物（モルホリンアクリルアミド）を含む反応生成物を製造した。
【００６４】
（２−４）その結果得られた反応生成物は無色で常温（２５℃）で粘稠な液状を呈していた。
この合成例２で得られた反応生成物中に含まれるウレタン化アクリル化合物（Ｉ）

１、Ｒ_３はエチル基であるウレタン化アクリル化合物である。
【００６５】
《合成例３》
〔ウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物を含む反応生成物の製造〕
（３−１）上記合成例２の（２−１）及び（２−２）と全く同様に行って反応物を得た。
（３−２）次いで、別の滴下ロートに仕込んだトリメチロールプロパンのエチレンオキサイド９モル付加物（トリメチロールプロパンの水酸基にエチレンオキサイドをそれぞれ３モル付加したもの）５３．０重量部を滴下し、８０〜９０℃で４時間反応させてウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物（モルホリンアクリルアミド）を含む反応生成物を製造した。
（３−３）その結果得られた反応生成物は無色で常温（２５℃）で粘稠な液状を呈していた。
この合成例３で得られた反応生成物中に含まれるウレタン化アクリル化合物

３、Ｒ_３はエチル基であるウレタン化アクリル化合物である。
【００６６】
《合成例４》
〔ウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物を含む反応生成物の製造〕
（４−１）攪拌機、温度調節器、温度計及び凝縮器を備えた内容量１リットルの三つ口フラスコにイソホロンジイソシアネート・イソシアヌレート・アダクト体（ＶＥＳＴＡＮＡＴＴ−１８９０／１００（デグサ・ヒュルスジャパン））２６６．４重量部、モルホリンアクリルアミド１７９．２４重量部、及びジブチル錫ジラウレート０．７重量部を仕込み、均一に溶解するまで攪拌した。
【００６７】
（４−２）４−ヒドロキシブチルアクリレート１１５．２重量部にメチルヒドロキノン０．４重量部を均一に混合溶解させた液を上記（４−１）の内容物に滴下混合して８０〜９０℃で２時間攪拌した。
【００６８】
（４−３）次いで、別の滴下ロートに仕込んだペンタエリスリトールのプロピレンオキサイド４モル付加物（ペンタエリスリトールの水酸基にプロピレンオキサイドをそれぞれ１モル付加したもの）３６．６重量部を添加し、８０〜９０℃で４時間反応させてウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物（モルホリンアクリルアミド）を含む反応生成物を製造した。（４−４）その結果得られた反応生成物は無色で常温（２５℃）で粘稠な液状を呈していた。
【００６９】
この合成例４で得られた反応生成物中に含まれるウレタン化アクリル化合物

１であるウレタン化アクリル化合物である。
【００７０】
《合成例５》
〔ウレタン化アクリル化合物及びラジカル重合性化合物を含む反応生成物の製造〕
（５−１）攪拌機、温度調節器、温度計及び凝縮器を備えた内容量５Ｌの三つ口フラスコにイソホロンジイソシアネート２２２重量部、モルホリンアクリルアミド２５７重量部、及びジブチル錫ジラウレート０．７重量部を仕込み、均一に溶解するまで攪拌した。
【００７１】
（５−２）合成例１の（１−１）で得られたグリセリンのアクリレートメタアクリレート化合物２８６重量部にメチルヒドロキノン０．４重量部を均一に混合溶解させた液を上記（５−１）の内容物に滴下混合して８０〜９０℃で２時間攪拌した。
【００７２】
（５−３）次いで、別の滴下ロートに仕込んだペンタエリスリトールのプロピレンオキサイド４モル付加物（ペンタエリスリトールの水酸基にプロピレンオキサイドをそれぞれ１モル付加したもの）９１．５重量部を滴下し、８０〜９０℃で４時間反応させてウレタン化アクリル化合物（Ｉ）及びラジカル重合性化合物（モルホリンアクリルアミド）を含む反応生成物を製造した。
【００７３】
（５−４）その結果得られた反応生成物は無色で常温（２５℃）で粘稠な液状を呈していた。
この合成例５で得られた反応生成物中に含まれるウレタン化アクリル化合物（Ｉ）

Ａ＝イソホロンジイソシアネート残基、ｂ＝４、Ｒ_２はメチル基、ｎの総和が４、ｎの平均値が１であるウレタン化アクリル化合物である。
【００７４】
《合成例６》
〔イソシアヌレート環構造を有するウレタン化アクリル化合物（特開６−１２８３４２）の製造〕
（６−１）攪拌機、温度調節器、温度計及び凝縮器を備えた内容量１リットルの三つ口フラスコにイソホロンジイソシアネート・イソシアヌレート・アダクト体（ＶＥＳＴＡＮＡＴＴ−１８９０／１００（デグサ・ヒュルスジャパン））１０２．３重量部及びジブチル錫ジラウレート０．７６重量部を仕込み均一になるように加熱・攪拌した。
【００７５】
（６−２）滴下ロートに仕込んだポリネオペンチレンアジペート（旭電化社製：アデカニューエースＹ９−１０）４２．０重量部を（６−１）のフラスコに滴下し、６５℃で１時間反応させた。
【００７６】
（６−３）フラスコの内容物を５０℃に冷却した後、滴下ロートに２−ヒドロキシエチルアクリレート２５．４５重量部にメチルヒドロキノン０．９重量部を均一混合した液を仕込み、フラスコの内容物を滴下し、その後２時間攪拌下、反応を継続する。得られた反応性生物を温かいうちにフラスコから取り出した。
【００７７】
（６−４）この合成例６で得られたウレタン化アクリル化合物は下記式（Ｘ）で表される構造である。

【００７８】
《実施例１》［光硬化性樹脂組成物の調製］
攪拌機、冷却管および側管付き滴下ロートを備えた内容積５リットルの三つ口フラスコに、合成例１で得られたウレタン化アクリル化合物（Ｉ）とラジカル重合性化合物を含む反応生成物２０００重量部、モルホリンアクリルアミド１５００重量部およびジシクロペンタニルジアクリレート１０００重量部を仕込み、減圧脱気窒素置換した。次いで、紫外線を遮断した環境下に、１−ヒドロキシシクロヘキシルフェニルケトン（チバガイギー社製「イルガキュアー１８４」；光ラジカル重合開始剤）１５０重量部を添加し、完全に溶解するまで温度２５℃で混合攪拌して（混合撹拌時間約１時間）、無色透明な粘稠液体である光硬化性樹脂組成物（常温における粘度約７５０ｃｐ）を得た。
【００７９】
《実施例２〜４》［光硬化性樹脂組成物の調製］
実施例１で用いた反応生成物の代わりに、合成例２〜４で得られたウレタン化アクリル化合物とラジカル重合性化合物を含む反応生成物を用いた以外は実施例１と同様にして光硬化性樹脂組成物を調製したところ、無色透明な粘稠液体である光硬化性樹脂組成物がそれぞれ得られた。結果を以下表にまとめた。
【００８０】
《比較例１》［光硬化性樹脂組成物の調製］
実施例１で用いた反応生成物の代わりに、合成例５で得られたウレタン化アクリル化合物とラジカル重合性化合物を含む反応生成物を用いた以外は実施例１と同様にして光硬化性樹脂組成物を調製したところ、無色透明な粘稠液体である光硬化性樹脂組成物がそれぞれ得られた（常温における粘度約５３０ｃｐ）。結果を以下表にまとめた。
【００８１】
《比較例２》［光硬化性樹脂組成物の調製］
ウレタン化アクリル化合物として合成例６で得られたウレタン化アクリル化合物１３２０ｇとポリエチレングリコール２００ジアクリレート（ソマール社製：サートマーＳＲ２５９）１０８０重量部及びエトキシ変性トリメチロールプロパントリアクリレート（ソマール社製：サートマーＳＲ４５４）４８０重量部を仕込み、減圧脱気窒素置換した。次いで、紫外線を遮断した環境下に、２，２−ジメトキシ−２−フェニルアセトフェノン（チバガイギー社製「イルガキュアー６５１」；光ラジカル重合開始剤）１２０重量部を添加し、完全に溶解するまで温度２５℃で混合攪拌して（混合撹拌時間約１時間）、無色透明な粘稠液体である光硬化性樹脂組成物（常温における粘度約１５５０ｃｐ）を得た。
【００８２】
《実施例５》［光学的立体造形法による立体造形物の製造］
上記の実施例１で得られた光硬化性樹脂組成物を用いて、超高速光造形システム（帝人製機株式会社製「ＳＯＬＩＦＯＲＭ５００」）を使用して、半導体レーザー光（出力１００ｍＷ；波長３５５ｎｍ）を表面に対して垂直に照射して、スライスピッチ（積層厚み）０．１２５ｍｍ、１層当たりの平均造形時間２分で光造形を行って、ＪＩＳ ７１１３に準拠するダンベル試験片形状の立体造形物を製造した。得られた立体造形物をイソプロピルアルコールで洗浄して立体造形物に付着している未硬化の樹脂液を除去した後、３ＫＷの紫外線を１０分間照射してポストキュアしたところ、透明性に優れる立体造形物が得られた。その立体造形物（ダンベル形状試験片）の引っ張り特性（引張強度、引張伸度および引張弾性率）をＪＩＳ Ｋ ７１１３に準拠して測定したところ、下記の表１に示すとおりであった。また、上記で得られたポストキュア後のダンベル形状試験片（立体造形物）の熱変形温度を実施例４と同様にして測定したところ、下記の表１に示すとおりであった。更に、この実施例５の立体造形法に用いた光硬化前の光硬化性樹脂組成物の比重（ｄ_１）と、ポストキュア後の立体造形物の比重（ｄ_２）をそれぞれ測定して、上記の数式（２）によりその体積収縮率（％）を求めたところ、下記の表１に示すとおりであった。
【００８３】
《実施例６〜８》［光学的立体造形法による立体造形物の製造］
上記の実施例２〜４で得られた光硬化性樹脂組成物を用いた以外は実施例５と同様にして光学的立体造形、未硬化樹脂の洗浄およびポストキュアを行って、透明性に優れる立体造形物（ダンベル形状試験片）を製造した。その結果得られたダンベル形状試験片（立体造形物）の引っ張り特性、熱変形温度および体積収縮率を実施例５と同様にして測定したところ、下記の表１に示すとおりであった。
【００８４】
《比較例３，４》［光学的立体造形法による立体造形物の製造］
上記の比較例１、２で得られた光硬化性樹脂組成物を用いた以外は実施例５と同様にして光学的立体造形、未硬化樹脂の洗浄およびポストキュアを行って、透明な立体造形物（ダンベル形状試験片）を製造した。その結果得られたダンベル形状試験片（立体造形物）の引っ張り特性、熱変形温度および体積収縮率を実施例５と同様にして測定したところ、下記の表１に示すとおりであった。
【００８５】
【表１】

上記の表１の結果から、実施例５〜８の場合には、本発明のウレタン化アクリル化合物（Ｉ）の範疇に包含されるでウレタン化アクリル化合物を含む実施例１〜４の光硬化性樹脂組成物を使用していることによって、そこで得られたモールド成形品および立体造形物は、１１０℃を大幅に超える高い熱変形温度を有していて耐熱性に極めて優れていること、しかも光硬化時の体積収縮率が小さくて寸法安定性にも優れており、その上引張強度および引張弾性率も高く力学的特性にも優れていることがわかる。
【００８６】
それに対して、比較例３の場合には、上記の一般式（Ｉ）で表されるウレタン化アクリル化合物において、基Ａはイソフォロンジイソシアネート残基であって本発明のウレタン化アクリル化合物（Ｉ）の範疇に包含されないウレタン化アクリル化合物を含む比較例１の光硬化性樹脂組成物を使用していることによって、そこで得られた立体造形物は、熱変形温度が１０５℃と低くて耐熱性に劣っていることがわかる。
【００８７】
一方、本発明と同じく、構成成分としてイソシアヌレート環構造を組み入れているものの、本発明のウレタン化アクリル化合物（Ｉ）の範疇に包含されないウレタン化アクリル化合物を含む比較例４の光硬化性樹脂組成物の場合は、粘度が高過ぎて、光学的立体造形法への適用には使用が著しく制限された。しかもそこで得られた立体造形物は、熱変形温度が５９℃と極めて低くて耐熱性に劣っていることがわかる。
【００８８】
《実施例９》［充填剤を含有する光硬化性樹脂組成物の調整］
攪拌機、冷却管および側管付き滴下ロートを備えた内容積５リットルの三つ口フラスコに、合成例３で得られたウレタン化アクリル化合物（Ｉ）とラジカル重合性化合物を含む反応生成物７７７重量部、モルホリンアクリルアミド５６重量部およびジシクロペンタニルジアクリレート２７８重量部を仕込み、減圧脱気窒素置換した。次いで、紫外線を遮断した環境下に、１−ヒドロキシシクロヘキシルフェニルケトン（チバガイギー社製「イルガキュアー１８４」；光ラジカル重合開始剤）３７重量部を添加し、完全に溶解するまで温度２５℃で混合攪拌して（混合撹拌時間約１時間）、無色透明な粘稠液体である光硬化性樹脂組成物を得た。
【００８９】
次に得られた光硬化性樹脂組成物１３５０重量部を万能撹拌機（ダルトン株式会社製；内容積１０リットル）に入れ、これにアクリルシラン系カップリング剤［東芝シリコーン社製；γ（メタクリロキシプロピル）トリメトキシシラン］で処理したガラスビーズ［平均粒径＝１．７５μｍ、上記の数式（１）による真球度の相対標準偏差値＝０．３］（東芝パロディーニ（株）製「ＭＢ−１０Ｃ」を１３５５重量部、および同じアクリルシラン系カップリング剤で処理したホウ酸アルミニウムウイスカー（四国化成工業株式会社製「アルボレックスＹＳ−４」；径０．５〜０．７μｍ、アスペクト比５０〜７０）を４８８重量部を添加し、一日撹拌し、脱泡処理して、充填剤を含有する光硬化性樹脂組成物（２５℃における粘度約８４０００ｍＰａ・ｓ）を得た。
【００９０】
《比較例５》［充填剤を含有する光硬化性樹脂組成物の調整］
合成例６で得られた光硬化性樹脂組成物２５９０重量部、アクロイルモルホリン１８６重量部、及びジシクロペンタニルジアクリレート９２７重量部を万能撹拌機（ダルトン株式会社製；内容積１０リットル）に入れ、これにアクリルシラン系カップリング剤［東芝シリコーン社製；γ（メタクリロキシプロピル）トリメトキシシラン］で処理したガラスビーズ［平均粒径＝１．７５μｍ、上記の数式（１）による真球度の相対標準偏差値＝０．３］（東芝パロディーニ（株）製「ＭＢ−１０Ｃ」を４５１６ｇ、および同じアクリルシラン系カップリング剤で処理したホウ酸アルミニウムウイスカー（四国化成工業株式会社製「アルボレックスＹＳ−４」；径０．５〜０．７μｍ、アスペクト比５０〜７０）を１６２６ｇを添加し、一日撹拌し、脱泡処理して、充填剤を含有する光硬化性樹脂組成物（２５℃における粘度約２５０００ｍＰａ・ｓ）を得た。
【００９１】
《実施例１０》［光学的立体造形法による立体造形物の製造］
上記の実施例９で得られた光硬化性樹脂組成物を用いた以外は実施例５と同様にして光学的立体造形、未硬化樹脂の洗浄およびポストキュアを行って、透明性に優れる立体造形物（ダンベル形状試験片）を製造した。その結果得られたダンベル形状試験片（立体造形物）の引っ張り特性、熱変形温度および体積収縮率を実施例５と同様にして測定したところ、下記の表２に示すとおりであった。
【００９２】
《比較例６》［光学的立体造形法による立体造形物の製造］
上記の比較例５で得られた光硬化性樹脂組成物を用いた以外は実施例５と同様にして光学的立体造形、未硬化樹脂の洗浄およびポストキュアを行って、透明性に優れる立体造形物（ダンベル形状試験片）を製造した。その結果得られたダンベル形状試験片（立体造形物）の引っ張り特性、熱変形温度および体積収縮率を実施例５と同様にして測定したところ、下記の表２に示すとおりであった。
【００９３】
【表２】

上記の表２の結果から、本発明のウレタン化アクリル化合物（Ｉ）の範疇に包含されるでウレタン化アクリル化合物、他のラジカル重合性化合物および光重合開始剤を含み、しかも固体微粒子およびウイスカーを更に含有する実施例９の光硬化性樹脂組成物を用いて立体造形物を製造している実施例１０による場合は、２００℃に近い、高い熱変形温度を有する、耐熱性に優れる光硬化物（立体造形物）が得られること、しかも光硬化時の体積収縮率が極めて小さくて寸法精度が一層向上していること、その上引張強度も高く力学的特性にも優れていることがわかる。
【００９４】
【発明の効果】
本発明の光硬化性樹脂組成物は、低粘度の液状を呈していて取り扱い性に優れ、短い硬化時間で硬化できるので、光照射法による各種の成形品、立体造形物、その他の製品の製造に有効に使用することができる。そして、本発明の光硬化性樹脂組成物を用いた場合には、光硬化時の体積収縮率が小さいために、寸法精度に優れる成形品や立体造形物を得ることができる。さらに、本発明の光硬化性樹脂組成物を光硬化させて得られる成形品や立体造形物などの光硬化物は、１００℃を超える高い熱変形温度を有していて耐熱性に極めて優れており、しかも引張強度、引張弾性率などが高く、力学的特性にも優れている。そして、本発明の光硬化性樹脂組成物中に固体微粒子およびウイスカーから選ばれる少なくとも１種の充填剤を含有させたものでは、得られる光硬化物の熱変形温度が一層向上し、光硬化時の体積収縮が一層低減され、耐熱性および寸法精度の点で一層優れる成形品や造形物などの光硬化物を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photocurable resin composition, a three-dimensional structure using the photocurable resin composition, and a urethanized acrylic compound used in the photocurable resin composition. More specifically, the present invention has a small volume shrinkage ratio upon photocuring and excellent dimensional accuracy, and also has a high heat distortion temperature and excellent heat resistance, and excellent mechanical properties such as transparency and tensile strength. A photocurable resin composition capable of obtaining a molded article, a three-dimensional molded article, etc., a molded article formed by an optical three-dimensional modeling method using the photocurable resin composition, and a urethane used in the photocurable resin composition Relates to a modified acrylic compound.
[0002]
[Prior art]
In general, liquid photocurable resin compositions are widely used as coatings (particularly hard coating agents), photoresists, dental materials, etc., but in recent years, photocurable resin compositions are based on data input to three-dimensional CAD. A method of three-dimensional optical modeling of a resin composition has attracted particular attention. Regarding the optical three-dimensional modeling technology, the liquid photocurable resin is supplied with a required amount of controlled light energy to be cured into a thin layer, and further supplied with the liquid photocurable resin, then the light is controlled. An optical three-dimensional modeling method for manufacturing a three-dimensional model by repeating the process of irradiating and curing in a thin layer is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 56-144478), and its basics. A practical method was further proposed by Patent Document 2 (Japanese Patent Laid-Open No. 60-247515). Since then, many proposals relating to optical three-dimensional modeling technology have been made. For example, Patent Literature 3 (Japanese Patent Laid-Open No. 62-35966), Patent Literature 4 (Japanese Patent Laid-Open No. 1-204915), and Patent Literature 5 ( JP-A-2-113925), Patent Document 6 (JP-A-2-145616), Patent Document 7 (JP-A-2-153722), Patent Document 8 (JP-A-3-15520), Patent Document No. 9 (Japanese Patent Laid-Open No. 3-21432), Patent Document 10 (Japanese Patent Laid-Open No. 3-41126), and the like disclose techniques relating to an optical three-dimensional modeling method.
[0003]
As a typical method for optically producing a three-dimensional model, an ultraviolet laser controlled by a computer is selected so that a desired pattern can be obtained on the liquid surface of the liquid photocurable resin composition placed in a container. And then cured to a predetermined thickness, and then a liquid resin composition for one layer was supplied on the cured layer and irradiated with an ultraviolet laser in the same manner to be cured in the same manner as described above to be continuous. A method of manufacturing a three-dimensional modeled object having a final shape by repeating a stacking operation of forming a hardened layer is widely used. In the case of this method, since a desired three-dimensional object can be manufactured easily and in a relatively short time even if the shape of the object is considerably complicated, it has attracted particular attention in recent years.
[0004]
Photocurable resin compositions used for coatings, photoresists, dental materials, etc. include curable resins such as unsaturated polyesters, epoxy (meth) acrylates, urethane (meth) acrylates, and (meth) acrylate monomers. A photopolymerization initiator added with a photopolymerization initiator is widely used. Photocurable resin compositions used in the optical three-dimensional modeling method include photopolymerizable modified (poly) urethane (meth) acrylate compounds, oligoester acrylate compounds, epoxy acrylate compounds, epoxy compounds, polyimides And a compound obtained by adding a photopolymerization initiator to one or more photopolymerizable compounds such as a series compound, an aminoalkyd compound, and a vinyl ether compound as a main component. JP-A-1-204915), Patent Document 11 (JP-A-1-213304), Patent Document 12 (JP-A-2-28261), Patent Document 13 (JP-A-2-75617), Patent Document 6 (JP-A-2-145616), Patent Document 14 (JP-A-3-104626), Patent Document 15 (JP-A-2-104626) 3-114732 discloses), various improved technique of the like is disclosed.
[0005]
The photocurable resin composition used in the optical three-dimensional modeling method is a low-viscosity liquid material from the viewpoints of handleability, modeling speed, modeling accuracy, etc., small volume shrinkage during curing, photocuring Therefore, it is required that the three-dimensional molded object obtained has good mechanical properties. In recent years, the demand and application of optical three-dimensional objects have been increasing, and depending on the application, it has high heat distortion temperature, excellent heat resistance, and transparency in addition to the above-mentioned characteristics. There has been a demand for a three-dimensional model that is excellent in performance. For example, in optical three-dimensional objects used for designing complex heat medium circuits and optical three-dimensional objects used for analyzing heat medium behavior of complicated structures, volume shrinkage during photocuring is small, and heat distortion temperature It is important to have a high transparency and excellent transparency.
[0006]
Conventionally, for the purpose of obtaining an optical three-dimensional molded article with improved heat resistance, a method of introducing a benzene ring into a molecule of a photocurable resin, a method of increasing the crosslinking density in a photocurable product, and the like have been studied. I came.
Patent Document 16 (Japanese Patent Laid-Open No. 6-128342) proposes to introduce an isocyanurate ring aimed at improving heat resistance instead of a benzene ring. In Patent Document 17 (Japanese Patent Laid-Open No. 9-227640), Patent Document 18 (Japanese Patent Laid-Open No. 10-1209797), and Patent Document 19 (Japanese Patent Laid-Open No. 2000-204125), the crosslinked structure is replaced with a special one. A urethane acrylate resin is proposed.
However, even in that case, the heat distortion temperature under high load is about 70 to 80 ° C., and the heat resistance is not sufficient. Moreover, when trying to improve the heat resistance of the photocured product, on the other hand, the volume shrinkage at the time of curing increases, leading to a decrease in dimensional accuracy, both the improvement of heat resistance and the reduction of volume shrinkage at the time of curing. A photocurable resin composition that satisfies the above properties has not been obtained yet.
In general, if the crosslink density in the photocurable resin composition is increased, an improvement in heat resistance can be expected, but at the same time, increasing the crosslink density tends to increase the volume shrinkage during curing. There is a tradeoff between improvement and reduction of volume shrinkage during curing. Therefore, as described above, a great number of photocurable resin compositions have been proposed in the past, but they have high heat resistance such that the heat distortion temperature under a high load exceeds 100 ° C., and at the time of curing. A photocurable resin composition capable of forming a molded article or a three-dimensionally shaped article having a small volume shrinkage and excellent in transparency and mechanical properties has not yet been provided.
[0007]
[Patent Document 1]
JP 56-144478 A
[Patent Document 2]
JP 60-247515 A
[Patent Document 3]
JP-A-62-35966
[Patent Document 4]
JP-A-1-204915
[Patent Document 5]
Japanese Patent Laid-Open No. 2-113925
[Patent Document 6]
Japanese Patent Laid-Open No. 2-145616
[Patent Document 7]
JP-A-2-153722
[Patent Document 8]
Japanese Patent Laid-Open No. 3-15520
[Patent Document 9]
Japanese Patent Laid-Open No. 3-21432
[Patent Document 10]
JP-A-3-41126
[Patent Document 11]
JP-A-1-213304
[Patent Document 12]
JP-A-2-28261
[Patent Document 13]
Japanese Patent Laid-Open No. 2-75617
[Patent Document 14]
Japanese Patent Laid-Open No. 3-104626
[Patent Document 15]
Japanese Patent Laid-Open No. 3-114732
[Patent Document 16]
JP-A-6-128342
[Patent Document 17]
JP-A-9-227640
[Patent Document 18]
Japanese Patent Laid-Open No. 10-12097
[Patent Document 19]
JP 2000-204125 A
[0008]
[Problems to be solved by the invention]
The object of the present invention is to exhibit a low-viscosity liquid, excellent handleability, can be cured in a short photocuring time, has a small volume shrinkage when cured with light, has excellent dimensional accuracy, and has a high thermal deformation temperature. Another object is to provide a photo-curable resin composition that is excellent in heat resistance, and that is capable of obtaining a molded product, a three-dimensionally shaped product, and other cured products that are excellent in mechanical properties such as transparency and tensile strength. And the objective of this invention is providing the method of manufacturing a molded article by the optical three-dimensional modeling method using said photocurable resin composition. Furthermore, the objective of this invention is providing the novel urethane acryl compound used with said photocurable resin composition.
[0009]
[Means for Solving the Problems]
The inventors of the present invention have repeatedly studied to achieve the above-described object. As a result, a novel urethanized acrylic compound having a specific chemical structure synthesized by the present inventors is extremely effective in achieving the above-mentioned object. When an initiator is added, a liquid photocurable resin composition having a low viscosity and excellent handleability can be obtained, and when the photocurable resin composition is irradiated with light, it can be cured in a short period of time. The volumetric shrinkage of the three-dimensional object can be manufactured with high dimensional accuracy, and the three-dimensional object obtained by photocuring has a high thermal deformation temperature exceeding 100 ° C. In addition, it was found to be excellent in heat resistance and excellent in transparency and mechanical properties.
[00010]
Furthermore, the present inventors include at least one filler selected from solid fine particles and whiskers in the photocurable resin composition containing the above-described novel urethanized acrylic compound invented by the present inventors. In addition, the molded products and molded products obtained by photocuring them retain extremely good mechanical strength, but they have extremely high thermal deformation that is unknown to conventional photocurable resin compositions of this type. It has a very high heat distortion temperature exceeding 200 ° C. depending on the temperature, and is extremely excellent in heat resistance, and also has a very high dimensional accuracy because the volume shrinkage during photocuring is greatly reduced. The present invention was completed based on the various findings described above.
[0011]
    That is, the present invention
(1) (i) the following general formula (I);

In the formula (I), a is 1 or 2, and when a is 1, R₁Is a hydrogen atom or methyl

A substituent (structure),when a is 2, one is a methyl group and the other is a hydrogen atom, or

If b = 3, then R₃Is a hydrogen atom, a methyl group or an ethyl group, and R_{2 is}A hydrogen atom or a methyl group, n is an integer of 0 to 20, but is not simultaneously greater than 0 and / or 4, the sum of n is 4 to 20, and the average value of n is 1 to 4.
[0012]
A is a trivalent substituent represented by the following general formula (II).

[0013]
In formula (II), Y is a C4-20 alkyl group or a substituent selected from the following formula group (III).

In formula (III), R₄Are independently a hydrogen atom and a lower alkyl group, and e = 0 to 10, f = 0 to 4, and g = 0 to 4.
Urethane acrylic compound represented by
[0014]
(Ii) radically polymerizable compounds other than the urethanized acrylic compounds, and
(Iii) A photocurable resin composition containing a photopolymerization initiator, wherein the content ratio of the urethanized acrylic compound: the radical polymerizable compound is in the range of 80:20 to 10:90 by weight ratio. A photocurable resin composition characterized by
[0015]
(2) In the above general formula (I), A is a urethanized acrylic compound composed of at least one triisocyanate residue selected from the following formula group (IV): (1) It is a photocurable resin composition described,

[0016]
  (3) One molecule of the urethanized acrylic compound represented by the above general formula (I) has at least six substituents represented by the following formula (V): (1) Or (2) the photocurable resin composition,

It is a substituent (structure).
[0017]
(4) The photocuring according to (1) to (3), wherein the content of the photopolymerization initiator is 0.1 to 10% by weight based on the total weight of the urethanized acrylic compound (I) and the radical polymerizable compound. A functional resin composition,
(5) The photocurable resin composition according to any one of (1) to (4), further comprising at least one filler selected from solid fine particles and whiskers,
(6) The photocurable resin composition according to (5), which contains both solid fine particles and whiskers,
(7) The photocurable resin composition according to (5), wherein the solid fine particles are spherical solid fine particles having a smooth surface with little light irregular reflection.
(8) The photocurable resin composition according to any one of (5) to (7), wherein a whisker having a diameter of 0.01 to 1 μm, a length of 1 to 70 μm, and an aspect ratio of 5 to 100 is used.
(9) The photocurable resin composition according to any one of (5) to (8), wherein at least one filler selected from solid fine particles and whiskers is treated with a silane coupling agent.
(10) The total content of at least one filler selected from solid fine particles and whiskers is 3 to 70% by volume based on the volume of the photocurable resin composition before containing them. (5) ~ 9 photocurable resin composition,
(11) A photocurable resin composition according to any one of (1) to (10), which is a resin composition for optical three-dimensional modeling,
Using the photocurable resin composition according to any one of (12) (1) to (11), a method for producing a three-dimensional structure by an optical three-dimensional structure method,
[0018]
(13) (i) the following general formula (I);

In which a is 1 or 2, and when a is 1, R₁Is a hydrogen atom or a methyl group, X is

Made)when a is 2, one is a methyl group and the other is a hydrogen atom, or

If b = 3, then R₃Is a hydrogen atom, a methyl group or an ethyl group, and R₂Is a hydrogen atom or a methyl group, n is an integer of 0 to 20, but is not simultaneously greater than 0 and / or 4, the total of n, the sum is 4 to 20, and the average value of n is 1 to 4 , A is a trivalent substituent represented by the following general formula (11).
[0019]

In formula (II), Y is a C4-20 alkyl group or a substituent selected from the following formula group (III).
[0020]

In formula (III), R₄Are independently a hydrogen atom and a lower alkyl group, and e = 0 to 10, f = 0 to 4, and g = 0 to 4.
It is a urethane-ized acrylic compound represented by these.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below. First, the urethanized acrylic compound (I) represented by the above general formula (I) used in the photocurable resin composition of the present invention will be described. In the urethanized acrylic compound (I) represented by the general formula (I),

[0022]

The group R in one or both of the groups¹Is a methyl group. Two groups when a is 2 in the urethanized acrylic compound (I);

It is necessary to go through irritating glycerin diacrylate, which cannot be used substantially and is not preferable.
[0023]
In the urethanized acrylic compound (I), the group A is a trivalent substituent represented by the following general formula (II):

Furthermore, Y is preferably an alkyl group having 4 to 20 carbon atoms or a substituent selected from the following formula group (III).
[0024]

R₄Are independently a hydrogen atom and a lower alkyl group, and e = 0 to 10, f = 0 to 4, and g = 0 to 4.
[0025]
Specifically, Y is an isophorone group, a tolylene group, a 4,4′-diphenylmethane group, a naphthylene group, a xylylene group, a phenylene group, a 3,3′-dichloro-4,4′-phenylmethane group, a toluylene group, a hexalene group, Examples thereof include a methylene group, 4,4′-dicyclohexylmethane group, hydrogenated xylylene group, hydrogenated diphenylmethane group, triphenylenemethane group, and tetramethylxylene group.
Among them, the group Y is more preferably an isophorone group, a tolylene group and / or a xylylene group, and more preferably an isophorone group.
That is, an isocyanurate structure composed of a trimer of isophorone diisocyanate is preferable.
In other words, the trimer of isophorone diisocyanate usually has four isomers, but any structure may be used. Specifically, a urethanized acrylic compound composed of at least one triisocyanate residue selected from the following formula group (IV) is preferable.
[0026]

Further, a triisocyanate compound selected from the above four structures is defined by the following formula (VI) and its residue represented by the following formula (VII).
[0027]

The group A described above may be used alone or in combination of two or more as required.
R₂Is a hydrogen atom and / or a methyl group, ie R in the above formula₂The structure shown in () containing is an ethylene glycol residue and / or a propylene glycol residue.
n is an integer of 0 to 20, but all n are not 0 at the same time. Moreover, all n is not simultaneously larger than 4, the sum total of n is 4-20, and the average value of n is 1-4.
The average value of n described here is a value obtained by dividing the total number of repeating units of ethylene glycol residue and / or propylene glycol residue by b.
[0028]
When the average value of n is larger than 4, even if an appropriate one is selected as the other radical polymerizable compound, the heat distortion temperature of the photocured product obtained by using the photocurable resin composition is sufficiently high. The heat resistance does not reach the desired level. On the other hand, when the average value of n is smaller than 1 or when n is all 0, that is, when the urethanized acrylic compound (I) has almost no ethylene oxide group or propylene oxide group, an improvement in heat resistance is recognized. However, volume shrinkage at the time of photocuring is large, and it is not possible to produce the target molded product or three-dimensional model with high dimensional accuracy, and moreover, gelation tends to occur when synthesizing a urethanized acrylic compound, Moreover, the viscosity of the urethanized acrylic compound obtained becomes abnormally high and cannot be used in the photocurable resin composition of the present invention.
[0029]
Preferred ethylene glycol residues and / or propylene glycol residues are described below.
The ethylene glycol residue has the formula:-(CH₂CH₂(O) n1- (wherein n1 represents an integer of 1 to 4) (poly) ethylene oxide group represented by the formula:-[CH₂CH (CH₃) O] n2- (wherein n2 represents an integer of 1 to 4) or a (poly) propylene oxide group represented by the formula: — (CH₂CH₂O) n3 [CH₂CH (CH₃) O] is a (poly) ethylene oxide propylene oxide group represented by n4- (wherein n3 and n4 are each an integer of 1 to 3, and the sum of n3 and n4 is 2 to 4).
More preferably, in the (poly) ethylene oxide group or (poly) propylene oxide group, n1 or n2 is preferably an integer of 1 to 3, respectively. Alternatively, in the (poly) ethylene oxide propylene oxide group represented by the above formula, the total of n3 and n4 is preferably 2 or 3.
More preferably,-[(CH₂CH (CH₃) O] n2- (wherein n2 is preferably 1 to 3, more preferably 1 to 2), it is a (poly) propylene oxide group, which has a higher heat distortion temperature and better heat resistance. In addition, the volume shrinkage during curing is smaller, and a relatively low viscosity photocurable resin composition can be obtained, which is preferable.
In the above formula, b is an integer of 3 or 4. When b is 3, R₃Is preferably a hydrogen atom or an ethyl group.
[0030]
One molecule of the urethanized acrylic compound represented by the general formula (I) has at least six substituents represented by the following formula (V).

[0031]
Where R₁Is synonymous with formula (I) above. X is at least one selected from the following formula group (VIII).

When the substituent represented by the formula (V) is smaller than 6, the heat distortion temperature of the photocured product obtained using the photocurable resin composition is not sufficiently high, and the heat resistance does not reach a desired level. .
The upper limit of the number of substituents represented by the formula (V) is not particularly limited, but is practically up to 16.
[0032]
And the photocurable resin composition of this invention is a radical polymerizable compound (other radical polymerizable compounds) other than the urethanized acrylic compound (I) (hereinafter referred to simply as “radical”) together with the urethanized acrylic compound (I). It is sometimes referred to as a “polymerizable compound”. As the radically polymerizable compound, carbon-carbon unsaturation that can react with the urethanized acrylic compound (I) upon irradiation with light and can react with the radically polymerizable compounds to form a cured product. Any radically polymerizable compound having a bond can be used, but acrylic compounds, allyl compounds and / or vinyl lactams are preferably used. In addition, the radical polymerizable compound may be either a monofunctional compound or a polyfunctional compound, or both a monofunctional compound and a polyfunctional compound may be used in combination. Further, the radically polymerizable compound may be a low molecular weight monomer, an oligomer, or may have a molecular weight that is somewhat high in some cases. And the photocurable resin composition of this invention may contain only 1 type of radically polymerizable compound as a radically polymerizable compound, or may contain 2 or more types of radically polymerizable compounds.
[0033]
Examples of the radical polymerizable compound that can be used as the radical polymerizable compound in the photocurable resin composition of the present invention include, but are not limited to, isobornyl (meth) acrylate, bornyl (meth) methacrylate, and dicyclopentenyl. (Meth) acrylates such as (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (poly) propylene glycol mono (meth) acrylate and t-butyl (meth) acrylate, morpholine Monofunctional radically polymerizable compounds such as (meth) acrylamides such as (meth) acrylamide, N-vinylcaprolactone and styrene; trimethylopropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) Chryrate, ethylene glycol di (meth) acrylate, diethylene glycol (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, 1,4-butanediol di (meth) Multifunctional such as acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, diallyl phthalate, diallyl fumarate, ethylene oxide modified bisphenol A diacrylate Radical polymerizable compounds.
[0034]
In addition to the radical polymerizable compounds described above, epoxy compounds conventionally used in optical three-dimensional resin compositions, urethanized acrylic compounds other than urethanized acrylic compounds (I), and epoxy (meth) acrylates Compounds, other ester (meth) acrylates, and the like can be used as the radical polymerizable compound.
In the photocurable resin composition of the present invention, the above-mentioned radical polymerizable compounds may be used alone or in combination of two or more. Among the various radical polymerizable compounds described above, in the photocurable resin composition of the present invention, morpholine (meth) acrylamide, dicyclopentenyl di (meth) acrylate, and N-vinylcaprolactam are more preferably used. In that case, when cured with light, the volume shrinkage rate is smaller, the dimensional accuracy is better, the heat distortion temperature is higher, the heat resistance is better, and the molded product and the three-dimensional shaped product are excellent in transparency and rigidity. Provides a photocurable resin composition that can be made into other cured products.
[0035]
And in the photocurable resin composition of this invention, it is necessary for the content rate of a urethanized acrylic compound (I): radically polymerizable compound to be 80: 20-10: 90 by weight ratio, 65 : 35 to 25:75 is preferable, and 60:40 to 35:65 is more preferable. In the photocurable resin composition, when the ratio of the urethanized acrylic compound (I) is less than 10% by weight based on the total weight of the urethanized acrylic compound (I) and the radical polymerizable compound, heat resistance when cured with light. Hardened products such as molded products and three-dimensional molded products with excellent properties and rigidity can no longer be obtained. On the other hand, if it exceeds 80% by weight, the volume shrinkage during photocuring increases and the dimensional accuracy decreases, and the photocurable resin composition The viscosity of the product becomes too high, and the handleability, moldability, and formability are lowered, and the intended three-dimensional model cannot be manufactured smoothly especially when used in the optical three-dimensional model method.
[0036]
Furthermore, the photocurable resin composition of the present invention contains a photopolymerization initiator together with the urethanized acrylic compound (I) and other radical polymerizable compounds. As the photopolymerization initiator, any radical photopolymerization initiator conventionally used in photocurable resin compositions can be used and is not particularly limited. Examples of the photopolymerization initiator that can be used in the photocurable resin of the present invention include, but are not limited to, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, diethoxyacetophenone, acetophenone 3-methylacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-propiophenone, 2-hydroxy-2-methyl-propiophenone, p-dimethyl Aminoacetophenone, pt-butyldichloroacetophenone, pt-butyltrichloroacetophenone, p-azidobenzalacetophenone, 1-hydroxycyclohexylphenylketono, benzophenone, methyl o-benzoylbenzoate, Michler's ketone, 4,4'-bi Diethylamino benzophenone, xanthone, it fluorenone, fluorene, benzaldehyde, anthraquinone, triphenylamine, and the like carbazole.
[0037]
When a compound having a radical polymerizable group and a cationic polymerizable group such as an epoxy group is used as the radical polymerizable compound, a photo cationic polymerization initiator may be used in combination with the above-described photo radical polymerization initiator. In this case, the type of the cationic photopolymerization initiator is not particularly limited, and those conventionally known can be used. The amount of photopolymerization initiator used may vary depending on the type of urethanized acrylic compound (I) and radical polymerizable compound, the type of photopolymerization initiator, etc., but in general, urethanized acrylic compound (I) and radical polymerization The content is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight, based on the total weight of the active compound.
[0038]
And this invention includes the photocurable resin composition which makes the above-mentioned photocurable resin composition further contain at least 1 sort (s) of filler chosen from a solid fine particle and a whisker in the scope of the present invention. In the photocurable resin composition of the present invention containing a filler selected from solid fine particles and whiskers, volume shrinkage at the time of photocuring can be further reduced, and a molded article or a molded article having further excellent dimensional accuracy can be obtained. it can. In addition, molded articles and molded articles obtained by photocuring a photocurable resin composition containing at least one filler selected from solid fine particles and whiskers can be obtained while maintaining their good mechanical properties. It has a high heat distortion temperature, and some have a heat distortion temperature exceeding 200 ° C., and the heat resistance is further improved.
[0039]
The photocurable resin composition of the present invention may contain only one type of filler selected from solid fine particles and whiskers, or may contain two or more types. That is, the photocurable resin composition of the present invention may contain only one or two or more kinds of solid fine particles, may contain only one or two or more kinds of whiskers, or may contain one or more kinds. You may contain both 2 or more types of solid fine particles and 1 type or 2 or more types of whiskers. And when the photocurable resin composition of the present invention contains both solid fine particles and whiskers (that is, contains one or more kinds of solid fine particles and one or more kinds of whiskers), Volume shrinkage at the time of photocuring is further reduced, and the heat distortion temperature of the photocured product is extremely high, and a photocured product such as a molded product or a modeled product having further excellent dimensional accuracy and heat resistance can be obtained.
[0040]
The content of the filler selected from solid fine particles and whiskers in the photocurable resin composition (the total content when containing two or more types) can be adjusted according to the type and form of the solid fine particles and whiskers. However, generally, it is preferably 3 to 70% by volume, more preferably 20 to 65% by volume based on the volume of the photocurable resin composition before containing the solid fine particles and / or whiskers. 30 to 60% by volume is more preferable. In particular, when the photocurable resin composition of the present invention contains only solid fine particles without containing whiskers, the content of the solid fine particles is based on the capacity of the photocurable resin composition before containing it. 3 to 70% by volume is preferable. Moreover, when the photocurable resin composition of the present invention contains only whiskers without containing solid fine particles, the whisker content is based on the capacity of the photocurable resin composition before containing it. It is preferable to set it as 3 to 30 volume%. By setting the content of the solid fine particles and the whisker in the photocurable resin composition within the above-described range, a molded article or a molded article having further excellent dimensional accuracy and heat resistance can be obtained. On the other hand, if the content of the solid fine particles and the whisker exceeds the above upper limit range, the viscosity of the photocurable resin composition becomes too high, and the handling property, the operability at the time of photocuring, and the like become poor, so care must be taken. .
[0041]
The solid fine particles to be contained in the photocurable resin composition have a smooth surface, hardly cause irregular reflection during light irradiation (at the time of energy beam irradiation), and are also molded products and shaped articles obtained by photocuring. Inorganic solid fine particles and organic polymer solid fine particles that do not cause decomposition or alteration at the temperature at which the photocured product is used are preferably used. In particular, as the solid fine particles, use is made of solid fine particles having a smooth spherical shape, in particular, true spherical solid fine particles whose relative standard deviation value of sphericity represented by the following formula (1) is 0.5 or less. It is preferable to do this. When solid fine particles having a relative standard deviation value of 0.5 or less are used, the irradiation light (irradiation energy rays) is prevented from being irregularly reflected by the solid fine particles when photocuring the photocurable resin composition. Thus, photocuring can be performed uniformly, and a photocured product with superior dimensional accuracy can be obtained, and an excessive increase in viscosity of the photocurable resin composition can be prevented.
[0042]
The solid fine particles preferably have an average particle size of 0.1 to 70 μm, more preferably 0.2 to 60 μm, and still more preferably 1 to 50 μm. If the average particle size of the solid fine particles is less than 0.1 μm, the viscosity of the photocurable resin composition tends to be excessively high. On the other hand, if the average particle size exceeds 70 μm, scattering of active energy occurs during irradiation and The photocured material tends to have low dimensional accuracy. Further, the solid fine particles may be transparent or opaque, and may be selected according to the type and use of the target molded article or shaped article. In order to obtain a photocured product that is excellent in transparency while improving heat resistance, the solid fine particles are made into submicron extremely small particles and subjected to appropriate surface treatment in the photocurable resin composition. It is also possible to stably disperse and suppress an increase in the viscosity of the photocurable resin composition.
[0043]
Examples of the solid fine particles that can be preferably used in the present invention include inorganic solid fine particles such as glass beads, talc fine particles, and silicon oxide fine particles; cross-linked polystyrene fine particles, cross-linked polymethacrylate fine particles, polyethylene fine particles, and polypropylene fine particles. These solid fine particles may be used alone, in combination of two or more, or in combination with whiskers.
Moreover, when the thing processed using the 1 type (s) or 2 or more types of silane coupling agents, such as aminosilane, an epoxy silane, and an acrylic silane, as solid fine particles, the mechanical strength of the hardened | cured material obtained by photocuring is obtained. Many cases of improvement are preferable. When the polyethylene-based solid fine particles and / or the polypropylene-based solid fine particles treated with the silane coupling agent are contained in the photocurable resin composition, a polyethylene-based copolymer obtained by copolymerizing about 1 to 10% by weight of an acrylic acid-based compound. Use of solid fine particles and / or polypropylene-based solid fine particles is preferable because the affinity with the silane coupling agent is increased.
[0044]
Moreover, when a whisker is included in the photocurable resin composition, it is preferable to use a whisker having a diameter of 0.01 to 1 μm, a length of 1 to 70 μm, and an aspect ratio of 5 to 100, and the diameter is 0. It is more preferable to use whiskers having a diameter of 0.05 to 1 μm, a length of 5 to 30 μm and an aspect ratio of 10 to 80. It is more preferable to use a certain whisker.
When the aspect ratio of the whisker is less than 5, it becomes difficult to obtain the effect of improving the mechanical characteristics and the effect of reducing the volume shrinkage due to the inclusion of the whisker, and the viscosity of the photocurable resin composition is increased. easy. On the other hand, if the whisker aspect ratio is increased, it is expected that the mechanical strength is reduced and the volume shrinkage is reduced. However, if the aspect ratio is too large, the viscosity of the photocurable resin composition increases and the fluid elasticity increases. Therefore, it is preferable that the aspect ratio is 100 or less because it is difficult to perform a shaping operation or the like, or the dimensional accuracy of the obtained photocured product is deteriorated, particularly the dimensional accuracy of the side surface of the photocured product is easily reduced. .
[0045]
Examples of whiskers that can be preferably used in the present invention include whiskers made of aluminum borate compounds, magnesium hydroxide sulfate compounds, aluminum oxides, titanium oxide compounds, silicon oxide compounds, and the like. May be used alone, in combination of two or more, or in combination with the above-described solid fine particles. Among those described above, whisker of an aluminum borate compound is preferably used. Moreover, when the whisker is treated with one or more of silane coupling agents such as aminosilane, epoxy silane, and acrylic silane, the mechanical strength of the cured product obtained by photocuring is improved. Many cases are preferred.
[0046]
The photocurable resin composition of the present invention may contain a leveling agent, a surfactant, an organic polymer modifier, an organic plasticizer, and the like as necessary in addition to the above-described components.
The viscosity of the photocurable resin composition of the present invention can be adjusted according to the application and use mode. Generally, when measured using a rotary B-type viscometer, at room temperature (25 ° C.), The viscosity is preferably about 100 to 100,000 centipoise (cp) from the viewpoints of handleability, moldability, and three-dimensional formability, and more preferably about 300 to 50,000 cp. In particular, when the photocurable resin composition of the present invention is used for optical three-dimensional modeling, the above-mentioned viscosity at room temperature is in the range of 300 to 5000 cp. It is desirable from the viewpoint that the property can be improved and the intended three-dimensional model can be manufactured smoothly with high dimensional accuracy. The viscosity of the photocurable resin composition can be adjusted by selecting the types of the urethanized acrylic compound (I) and the radical polymerizable compound, adjusting the blending ratio thereof, and the like.
[0047]
When the photocurable resin composition of the present invention is stored in a state where light can be blocked, the modification or polymerization is usually performed at a temperature of 10 to 40 ° C. for a long period of about 6 to 18 months. Can be preserved while maintaining good photocuring performance.
Although not limited, the following can be mentioned as an example of the urethanized acrylic compound (I) which can be used with the photocurable resin composition of this invention.
[0048]

1 is a urethanized acrylic compound, with a group A centered on one carbon source.

Urethane acrylic compounds.
[0049]

1, R₃Is a urethanized acrylic compound which is an ethyl group, centered on one carbon atom and its carbon atoms (ie the remaining group R₃Carbon atom to which

Urethane acrylic compound.
[0050]

3, R₃Is a urethanized acrylic compound which is an ethyl group, centered on one carbon atom and its carbon atoms (ie the remaining groups R₃To the carbon atom to which

Urethane acrylic compound.
[0051]

1, a urethanized acrylic compound centered on one carbon atom (ie the remaining group R₃To the carbon atom to which

Compound.
The photo-curable resin composition of the present invention has its characteristics, particularly volume shrinkage when cured by light, excellent dimensional accuracy, high heat distortion temperature, excellent heat resistance, and transparency. It can be used for various applications by taking advantage of the properties that a molded product, a three-dimensional model, and other cured products can be obtained, such as manufacturing a three-dimensional model by an optical three-dimensional modeling method, It can be used for the production and coating of various molded products such as membranes and molds by casting.
[0052]
Among them, the photo-curable resin composition of the present invention is suitable for use in the above-described optical three-dimensional modeling method, and in that case, the dimensional accuracy is excellent while keeping the volume shrinkage ratio during photo-curing small. In addition, it is possible to smoothly manufacture a three-dimensional structure that is excellent in heat resistance, rigidity, and transparency. In performing optical three-dimensional modeling using the photocurable resin composition of the present invention, any conventionally known optical three-dimensional modeling method and apparatus can be used. Among them, in the present invention, it is preferable to use an active energy beam generated from an Ar laser, a He-Cd laser, a xenon lamp, a metal halide lamp, a mercury lamp, a fluorescent lamp, or the like as light energy for curing the resin. A laser beam is particularly preferably used. When a laser beam is used as the active energy beam, it is possible to increase the energy level and shorten the modeling time, and obtain a three-dimensional modeled object with high modeling accuracy by utilizing the good condensing property of the laser beam. be able to.
[0053]
As described above, when performing optical three-dimensional modeling using the photocurable resin composition of the present invention, any of the conventionally known methods and the conventionally known stereolithography system apparatus can be adopted, but not particularly limited. As a representative example of the optical three-dimensional modeling method preferably used in the invention, an active energy beam is selectively used so that a cured layer having a desired pattern is obtained in a liquid photocurable resin composition containing a light energy absorber. To form a cured layer, and then supply an uncured liquid photocurable resin composition to the cured layer. Similarly, the cured layer continuous with the cured layer is irradiated with an active energy beam. The method of finally obtaining the target three-dimensional molded item can be mentioned by repeating the operation to form and laminate. And even if the three-dimensional model obtained by using it is used as it is, or in some cases, post-curing by light irradiation or post-curing by heat, etc., to further improve its mechanical properties and shape stability, etc. It may be used.
[0054]
In that case, the structure, shape, size, and the like of the three-dimensional structure are not particularly limited, and can be determined according to each application. And as a typical application field of the optical three-dimensional modeling method of the present invention, a model for verifying the appearance design in the middle of the design, a model for checking the functionality of the part, a resin for producing a mold Examples include molds, base models for producing molds, and direct molds for prototype molds. More specifically, mention the production of models for precision parts, electrical / electronic parts, furniture, building structures, automotive parts, various containers, castings, molds, mother molds, and processing models. Can do. In particular, taking advantage of its good heat resistance and transparency, it is extremely effective for high-temperature component trial manufacture, for example, designing complex heat transfer circuits, and manufacturing parts for analysis planning of heat transfer behavior used in complex structures. Can be used.
[0055]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples and the like, but the present invention is not limited to the following examples.
<< Synthesis Example 1 >>
[Production of reaction product containing urethanized acrylic compound (I) and radical polymerizable compound]
(1-1) Acrylic acid dimer (Aronix M-5600 manufactured by Toa Gosei Co., Ltd.) 187.2 parts by weight and 142 parts by weight of glycidyl methacrylate are placed in a four-necked flask, 33 parts by weight of triethylamine as a catalyst, and as a polymerization inhibitor. 0.28 parts by weight of methylhydroquinone was added, and the reaction was carried out for 5 hours while stirring at 80 to 85 ° C.
[0056]
To the obtained reaction product, 420 parts by weight of toluene was added and washed with 88 parts by weight of a 15% by weight aqueous caustic soda solution, followed by washing with 100 ml of water. Next, it was washed with 300 ml of 1N hydrochloric acid, and then washed with 100 ml of water until neutrality. Next, it was dried using sodium sulfate, and the solvent was removed under reduced pressure to obtain a glycerin acrylate methacrylate compound represented by the following chemical formula (IX).
[0057]

(1-2) An isophorone diisocyanate isocyanurate adduct (VESTANTATT-1890 / 100 (Degussa Huls Japan)) in a 1 L three-necked flask equipped with a stirrer, temperature controller, thermometer and condenser 266.4 parts by weight, 227.9 parts by weight of morpholine acrylamide, and 0.7 parts by weight of dibutyltin dilaurate were charged and stirred until evenly dissolved.
[0058]
(1-3) A content obtained by uniformly mixing and dissolving 0.4 parts by weight of methylhydroquinone in 228.8 parts by weight of the acrylate methacrylate compound obtained in (1) above is the contents of (1-2) above. The mixture was added dropwise and stirred at 80 to 90 ° C. for 2 hours.
[0059]
(1-4) Next, 36.6 parts by weight of propylene oxide 4 mol adduct of pentaerythritol charged in another dropping funnel (1 mol of propylene oxide added to the hydroxyl group of pentaerythritol) was added to the flask contents. Was reacted at 80 to 90 ° C. for 4 hours to produce a reaction product containing the urethanized acrylic compound (I) and the radical polymerizable compound (morpholine acrylamide).
[0060]
(1-5) The resulting reaction product was colorless and exhibited a viscous liquid at room temperature (25 ° C.).
Urethane acrylic compound (I) contained in the reaction product obtained in Synthesis Example 1

1 is a urethanized acrylic compound.
[0061]
<< Synthesis Example 2 >>
[Production of reaction product containing urethanized acrylic compound (I) and radical polymerizable compound]
(2-1) An isophorone diisocyanate isocyanurate adduct body (VESTANTATT-1890 / 100 (Degussa Huls Japan)) in a 1-liter three-necked flask equipped with a stirrer, a temperature controller, a thermometer, and a condenser 199.8 parts by weight, morpholine acrylamide 170.6 parts by weight, and dibutyltin dilaurate 0.7 parts by weight were charged and stirred until evenly dissolved.
[0062]
(2-2) A liquid obtained by adding 0.4 parts by weight of methylhydroquinone to 171.6 parts by weight of the glycerin acrylate methacrylate compound obtained in (1-1) of Synthesis Example 1 and mixing and dissolving it uniformly (2 -1) was added dropwise to the contents and stirred at 80 to 90 ° C for 2 hours.
[0063]
(2-3) Then, 26.6 parts by weight of trimethylolpropane ethylene oxide 3 mol adduct (1 mol of ethylene oxide added to the trimethylolpropane hydroxyl group) charged in another dropping funnel was dropped. A reaction product containing a urethanized acrylic compound (I) and a radical polymerizable compound (morpholine acrylamide) was produced by reacting at 80 to 90 ° C. for 4 hours.
[0064]
(2-4) The resulting reaction product was colorless and exhibited a viscous liquid at room temperature (25 ° C.).
Urethane acrylic compound (I) contained in the reaction product obtained in Synthesis Example 2

1, R₃Is an urethanized acrylic compound which is an ethyl group.
[0065]
<< Synthesis Example 3 >>
[Production of reaction product containing urethanized acrylic compound (I) and radical polymerizable compound]
(3-1) A reaction product was obtained in exactly the same manner as in (2-1) and (2-2) of Synthesis Example 2 above.
(3-2) Next, 53.0 parts by weight of trimethylolpropane ethylene oxide 9 mol adduct (3 mol of ethylene oxide added to the trimethylolpropane hydroxyl group each) charged in another dropping funnel was dropped. A reaction product containing a urethanized acrylic compound (I) and a radical polymerizable compound (morpholine acrylamide) was produced by reacting at 80 to 90 ° C. for 4 hours.
(3-3) The resulting reaction product was colorless and exhibited a viscous liquid at room temperature (25 ° C.).
Urethane acrylic compound contained in the reaction product obtained in Synthesis Example 3

3, R₃Is an urethanized acrylic compound which is an ethyl group.
[0066]
<< Synthesis Example 4 >>
[Production of reaction product containing urethanized acrylic compound (I) and radical polymerizable compound]
(4-1) Isophorone diisocyanate / isocyanurate / adduct body (VESTANTATT-1890 / 100 (Degussa Huls Japan)) in a 1-liter three-necked flask equipped with a stirrer, temperature controller, thermometer and condenser ) 266.4 parts by weight, morpholine acrylamide 179.24 parts by weight, and dibutyltin dilaurate 0.7 parts by weight were charged and stirred until evenly dissolved.
[0067]
(4-2) A solution prepared by uniformly mixing and dissolving 0.4 parts by weight of methylhydroquinone in 115.2 parts by weight of 4-hydroxybutyl acrylate is added dropwise to the content of the above (4-1) and mixed at 80 to 90 ° C. For 2 hours.
[0068]
(4-3) Next, 36.6 parts by weight of propylene oxide 4 mol adduct of pentaerythritol charged in another dropping funnel (1 mol of propylene oxide added to the hydroxyl group of pentaerythritol) was added, and 80- Reaction was carried out at 90 ° C. for 4 hours to produce a reaction product containing the urethanized acrylic compound (I) and a radical polymerizable compound (morpholine acrylamide). (4-4) The resulting reaction product was colorless and exhibited a viscous liquid at room temperature (25 ° C.).
[0069]
Urethane acrylic compound contained in the reaction product obtained in Synthesis Example 4

1 is a urethanized acrylic compound.
[0070]
<< Synthesis Example 5 >>
[Production of reaction product containing urethanized acrylic compound and radical polymerizable compound]
(5-1) 222 parts by weight of isophorone diisocyanate, 257 parts by weight of morpholine acrylamide, and 0.7 parts by weight of dibutyltin dilaurate were added to a 5 L three-necked flask equipped with a stirrer, a temperature controller, a thermometer and a condenser. Charged and stirred until evenly dissolved.
[0071]
(5-2) A liquid obtained by uniformly mixing and dissolving 0.4 parts by weight of methylhydroquinone in 286 parts by weight of the acrylate methacrylate compound obtained in (1-1) of Synthesis Example 1 is the above (5-1). The mixture was added dropwise to the contents and stirred at 80 to 90 ° C. for 2 hours.
[0072]
(5-3) Next, 91.5 parts by weight of propylene oxide 4 mol adduct of pentaerythritol charged in another dropping funnel (1 mol of propylene oxide added to the hydroxyl group of pentaerythritol) was added dropwise, Reaction was carried out at 90 ° C. for 4 hours to produce a reaction product containing the urethanized acrylic compound (I) and a radical polymerizable compound (morpholine acrylamide).
[0073]
(5-4) The resulting reaction product was colorless and exhibited a viscous liquid at room temperature (25 ° C.).
Urethane acrylic compound (I) contained in the reaction product obtained in Synthesis Example 5

A = isophorone diisocyanate residue, b = 4, R₂Is a urethanized acrylic compound in which the total of n is 4, and the average value of n is 1.
[0074]
<< Synthesis Example 6 >>
[Production of Urethane Acrylic Compound Having Isocyanurate Ring Structure (JP-A-6-128342)]
(6-1) Isophorone diisocyanate / isocyanurate / adduct body (VESTANTATT-1890 / 100 (Degussa Huls Japan)) in a 1-liter three-necked flask equipped with a stirrer, temperature controller, thermometer and condenser ) 102.3 parts by weight and 0.76 parts by weight of dibutyltin dilaurate were charged and heated and stirred to be uniform.
[0075]
(6-2) 42.0 parts by weight of polyneopentylene adipate (manufactured by Asahi Denka Co., Ltd .: Adeka New Ace Y9-10) charged in the dropping funnel was dropped into the flask of (6-1), and the mixture was heated at 65 ° C. for 1 hour. Reacted.
[0076]
(6-3) After cooling the contents of the flask to 50 ° C., a solution obtained by uniformly mixing 25.45 parts by weight of 2-hydroxyethyl acrylate with 0.9 parts by weight of methylhydroquinone was charged into the dropping funnel. Then, the reaction is continued with stirring for 2 hours. The resulting reactive organism was removed from the flask while warm.
[0077]
(6-4) The urethanized acrylic compound obtained in Synthesis Example 6 has a structure represented by the following formula (X).

[0078]
<< Example 1 >> [Preparation of photocurable resin composition]
A reaction product containing a urethanized acrylic compound (I) obtained in Synthesis Example 1 and a radically polymerizable compound in a three-necked flask having an internal volume of 5 liters equipped with a stirrer, a condenser tube and a dropping funnel with a side tube is 2000 weight. Parts, 1500 parts by weight of morpholine acrylamide, and 1000 parts by weight of dicyclopentanyl diacrylate were added, and vacuum deaeration and nitrogen substitution were performed. Next, 150 parts by weight of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy; photo radical polymerization initiator) is added under an environment where ultraviolet rays are blocked, and the mixture is stirred at a temperature of 25 ° C. until completely dissolved. (Mixing and stirring time of about 1 hour) to obtain a photocurable resin composition (viscosity of about 750 cp at room temperature) which is a colorless and transparent viscous liquid.
[0079]
<< Examples 2 to 4 >> [Preparation of Photocurable Resin Composition]
Photocuring in the same manner as in Example 1 except that instead of the reaction product used in Example 1, the reaction product containing the urethanized acrylic compound and radical polymerizable compound obtained in Synthesis Examples 2 to 4 was used. When the curable resin composition was prepared, the photocurable resin composition which was a colorless and transparent viscous liquid was obtained, respectively. The results are summarized in the table below.
[0080]
<< Comparative Example 1 >> [Preparation of Photocurable Resin Composition]
A photocurable resin was prepared in the same manner as in Example 1 except that the reaction product containing the urethanized acrylic compound and the radical polymerizable compound obtained in Synthesis Example 5 was used instead of the reaction product used in Example 1. When the composition was prepared, the photocurable resin composition which is a colorless and transparent viscous liquid was obtained, respectively (viscosity about 530 cp at normal temperature). The results are summarized in the table below.
[0081]
<< Comparative Example 2 >> [Preparation of Photocurable Resin Composition]
1320 g of urethane-modified acrylic compound obtained in Synthesis Example 6 as a urethane-modified acrylic compound, 1080 parts by weight of polyethylene glycol 200 diacrylate (Somar SR259) and ethoxy-modified trimethylolpropane triacrylate (Somar SR454) 480 parts by weight were charged and purged with nitrogen under reduced pressure. Next, 120 parts by weight of 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Geigy, Inc .; radical photopolymerization initiator) is added under an environment where ultraviolet rays are blocked, and the temperature is 25 until the solution is completely dissolved. The mixture was mixed and stirred at about 0 ° C. (mixing and stirring time was about 1 hour) to obtain a photocurable resin composition (viscosity of about 1550 cp at room temperature) which was a colorless and transparent viscous liquid.
[0082]
Example 5 [Manufacture of a three-dimensional object by optical three-dimensional modeling]
Using the photocurable resin composition obtained in Example 1 above, a semiconductor laser beam (output: 100 mW; wavelength: 355 nm) using an ultra-high-speed stereolithography system (“SOLIFORM500” manufactured by Teijin Seiki Co., Ltd.) Is formed perpendicularly to the surface, and is subjected to stereolithography with a slice pitch (lamination thickness) of 0.125 mm and an average modeling time of 2 minutes per layer, and is a three-dimensional model of a dumbbell specimen according to JIS 7113 Manufactured. The resulting three-dimensional model was washed with isopropyl alcohol to remove the uncured resin liquid adhering to the three-dimensional model, and after being cured by irradiation with 3 KW ultraviolet rays for 10 minutes, a three-dimensional model with excellent transparency. A model was obtained. The tensile properties (tensile strength, tensile elongation, and tensile modulus) of the three-dimensional modeled object (dumbbell-shaped test piece) were measured in accordance with JIS K 7113, and as shown in Table 1 below. Moreover, when the heat deformation temperature of the post-cure dumbbell-shaped test piece (three-dimensional model) obtained above was measured in the same manner as in Example 4, it was as shown in Table 1 below. Furthermore, specific gravity (d of the photocurable resin composition before photocuring used in the three-dimensional modeling method of Example 5 (d₁) And specific gravity (d₂) Were measured, and the volume shrinkage (%) was determined by the above mathematical formula (2), and as shown in Table 1 below.
[0083]
<< Examples 6 to 8 >> [Manufacture of a three-dimensional object by optical three-dimensional modeling]
Except for using the photocurable resin composition obtained in the above Examples 2 to 4, optical three-dimensional modeling, washing of uncured resin and post-cure are performed in the same manner as in Example 5 and excellent in transparency. A three-dimensional model (dumbbell-shaped test piece) was manufactured. The tensile properties, thermal deformation temperature, and volumetric shrinkage of the resulting dumbbell-shaped test piece (three-dimensional model) were measured in the same manner as in Example 5. The results are shown in Table 1 below.
[0084]
<< Comparative Examples 3 and 4 >> [Manufacture of a three-dimensional object by optical three-dimensional modeling]
Transparent three-dimensional modeling is performed by performing optical three-dimensional modeling, washing of uncured resin and post-cure in the same manner as in Example 5 except that the photocurable resin composition obtained in Comparative Examples 1 and 2 is used. A product (dumbbell-shaped test piece) was produced. The tensile properties, thermal deformation temperature, and volumetric shrinkage of the resulting dumbbell-shaped test piece (three-dimensional model) were measured in the same manner as in Example 5. The results are shown in Table 1 below.
[0085]
[Table 1]

From the results of Table 1 above, in the case of Examples 5 to 8, the photocurability of Examples 1 to 4 including the urethanized acrylic compound included in the category of the urethanized acrylic compound (I) of the present invention. By using the resin composition, the molded product and the three-dimensional molded article obtained there have a high heat distortion temperature significantly exceeding 110 ° C. and are extremely excellent in heat resistance, and light. It can be seen that the volumetric shrinkage during curing is small and the dimensional stability is excellent, and that the tensile strength and tensile modulus are also high and the mechanical properties are excellent.
[0086]
On the other hand, in the case of Comparative Example 3, in the urethanized acrylic compound represented by the above general formula (I), the group A is an isophorone diisocyanate residue and the urethanized acrylic compound (I) of the present invention. By using the photo-curable resin composition of Comparative Example 1 containing a urethanized acrylic compound not included in the category, the three-dimensional structure obtained there has a low heat distortion temperature of 105 ° C. and is heat resistant. It turns out that it is inferior.
[0087]
On the other hand, the photocurable resin composition of Comparative Example 4, which contains a urethanized acrylic compound that does not fall within the category of the urethanized acrylic compound (I) of the present invention, although incorporating an isocyanurate ring structure as a constituent component, as in the present invention In the case of objects, the viscosity was too high and its use was significantly limited for application to optical stereolithography. Moreover, it can be seen that the three-dimensional model obtained there has a very low heat distortion temperature of 59 ° C. and is inferior in heat resistance.
[0088]
<< Example 9 >> [Preparation of photocurable resin composition containing filler]
A reaction product containing urethanized acrylic compound (I) obtained in Synthesis Example 3 and a radical polymerizable compound in a three-necked flask having an internal volume of 5 liters equipped with a stirrer, a condenser tube and a dropping funnel with side tubes is 777 weight. Parts, 56 parts by weight of morpholine acrylamide and 278 parts by weight of dicyclopentanyl diacrylate were added, and vacuum deaeration and nitrogen substitution were performed. Next, 37 parts by weight of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy; photo radical polymerization initiator) is added in an environment where ultraviolet rays are blocked, and the mixture is stirred at a temperature of 25 ° C. until completely dissolved. (Mixing and stirring time of about 1 hour) to obtain a photo-curable resin composition which was a colorless and transparent viscous liquid.
[0089]
Next, 1350 parts by weight of the obtained photocurable resin composition was put into a universal stirrer (Dalton Co., Ltd .; internal volume 10 liters), and an acrylic silane coupling agent [manufactured by Toshiba Silicone Co .; γ (methacryloxy) Propyl) trimethoxysilane] -treated glass beads [average particle size = 1.75 μm, relative standard deviation of sphericity by the above formula (1) = 0.3] (manufactured by Toshiba Parodini Co., Ltd., “MB -10C "treated with 1355 parts by weight of the same acrylic silane coupling agent and aluminum borate whisker (" Arbolex YS-4 "manufactured by Shikoku Kasei Kogyo Co., Ltd .; diameter 0.5-0.7 µm, aspect ratio 50 ˜70) is added, 488 parts by weight, stirred for one day, defoamed, and a photocurable resin composition containing a filler (viscosity at 25 ° C. of about 84000 m). a · s) was obtained.
[0090]
<< Comparative Example 5 >> [Preparation of Photocurable Resin Composition Containing Filler]
2590 parts by weight of the photocurable resin composition obtained in Synthesis Example 6, 186 parts by weight of acroylmorpholine, and 927 parts by weight of dicyclopentanyl diacrylate were added to a universal stirrer (Dalton Co., Ltd .; internal volume 10 liters). Glass beads treated with an acrylic silane coupling agent [manufactured by Toshiba Silicone; γ (methacryloxypropyl) trimethoxysilane] [average particle size = 1.75 μm, sphericity according to the above formula (1) Relative standard deviation value of 0.3] (both “MB-10C” manufactured by Toshiba Parodini Co., Ltd.) and aluminum borate whisker (“Arbo” manufactured by Shikoku Kasei Kogyo Co., Ltd.) treated with the same acrylic silane coupling agent. Rex YS-4 ”; diameter 0.5-0.7 μm, aspect ratio 50-70) was added 1626 g and stirred for one day. And defoaming treatment to obtain a photocurable resin composition containing a filler (about 25,000 mPa · s viscosity at 25 ° C.).
[0091]
<< Example 10 >> [Manufacturing of a three-dimensional object by optical three-dimensional modeling]
Except for using the photocurable resin composition obtained in Example 9 above, optical stereolithography, uncured resin washing and post-cure are performed in the same manner as in Example 5 to achieve excellent 3D modeling. A product (dumbbell-shaped test piece) was produced. The tensile properties, thermal deformation temperature, and volumetric shrinkage of the resulting dumbbell-shaped test piece (three-dimensional model) were measured in the same manner as in Example 5. The results were as shown in Table 2 below.
[0092]
<< Comparative Example 6 >> [Manufacture of a three-dimensional object by optical three-dimensional modeling]
Except for using the photocurable resin composition obtained in Comparative Example 5 above, the optical three-dimensional modeling, uncured resin washing and post-cure are performed in the same manner as in Example 5, and the three-dimensional modeling is excellent in transparency. A product (dumbbell-shaped test piece) was produced. The tensile properties, thermal deformation temperature, and volumetric shrinkage of the resulting dumbbell-shaped test piece (three-dimensional model) were measured in the same manner as in Example 5. The results were as shown in Table 2 below.
[0093]
[Table 2]

From the results of Table 2 above, the urethanized acrylic compound (I) of the present invention includes a urethanized acrylic compound, another radical polymerizable compound, and a photopolymerization initiator, and further includes solid fine particles and whiskers. Further, in the case of Example 10 in which a three-dimensionally shaped product is manufactured using the photocurable resin composition of Example 9 to be contained, a photocured product having a high heat distortion temperature close to 200 ° C. and excellent in heat resistance. It can be seen that a (three-dimensional model) is obtained, and that the volumetric shrinkage during photocuring is extremely small and the dimensional accuracy is further improved, and that the tensile strength is high and the mechanical properties are excellent.
[0094]
【The invention's effect】
The photo-curable resin composition of the present invention exhibits a low-viscosity liquid, is easy to handle, and can be cured in a short curing time. Therefore, it can produce various molded products, three-dimensional models, and other products by the light irradiation method. Can be used effectively. And when the photocurable resin composition of this invention is used, since the volumetric shrinkage rate at the time of photocuring is small, the molded article and three-dimensional molded item which are excellent in dimensional accuracy can be obtained. Furthermore, a photocured product such as a molded product or a three-dimensional model obtained by photocuring the photocurable resin composition of the present invention has a high heat distortion temperature exceeding 100 ° C. and is extremely excellent in heat resistance. Moreover, it has high tensile strength, tensile modulus, etc., and excellent mechanical properties. And when the photocurable resin composition of the present invention contains at least one filler selected from solid fine particles and whiskers, the thermal deformation temperature of the resulting photocured product is further improved, and at the time of photocuring Volume shrinkage is further reduced, and a photocured product such as a molded product or a modeled product that is more excellent in terms of heat resistance and dimensional accuracy can be obtained.

Claims (13)

(I) the following general formula (I);

(In the formula (I), a is 1 or 2, and when a is 1, R ₁ is a hydrogen atom or methyl.

When a is 2, one is a methyl group and the other is a hydrogen atom, or

And when b = 3, R ₃ is a hydrogen atom, a methyl group or an ethyl group, R ₂ is a hydrogen atom or a methyl group, and n is an integer of 0 to 20, but simultaneously 0 and / or 4 The sum of n is 4 to 20, the average value of n is 1 to 4, and A is a trivalent substituent represented by the following general formula (II).

(In formula (II), Y is a C4-C20 alkyl group or a substituent selected from the following formula group (III).

In the formula, each R ₄ independently represents a hydrogen atom or a lower alkyl group, and e = 0 to 10, f = 0 to 4, and g = 0 to 4)))
Urethane acrylic compound represented by
(Ii) a photocurable resin composition containing a radical polymerizable compound other than the urethanized acrylic compound and (iii) a photopolymerization initiator, wherein the urethanized acrylic compound: the content ratio of the radical polymerizable compound Is in the range of 80:20 to 10:90 by weight ratio. 2. The light according to claim 1, wherein in the general formula (I), A is a urethanized acrylic compound composed of at least one triisocyanate residue selected from the following formula group (IV): Curable resin composition.

3. One molecule of a urethanized acrylic compound represented by the above general formula (I) has at least six substituents represented by the following formula (V). Photocurable resin composition.

Substituent (structure) The photocurability according to any one of claims 1 to 3 , wherein the content of the photopolymerization initiator is 0.1 to 10% by weight based on the total weight of the urethanized acrylic compound (I) and the radical polymerizable compound. Resin composition. The photocurable resin composition according to any one of claims 1 to 4 , further comprising at least one filler selected from solid fine particles and whiskers. The photocurable resin composition according to claim 5, comprising both solid fine particles and whiskers. The photocurable resin composition according to claim 5 solid fine particles are spherical solid fine particles. The photocurable resin composition according to claim 5, wherein whiskers having a diameter of 0.01 to 1 μm, a length of 1 to 70 μm, and an aspect ratio of 5 to 100 are used. The photocurable resin composition according to any one of claims 5 to 8, wherein at least one filler selected from solid fine particles and whiskers is treated with a silane coupling agent. The total content of at least one filler selected from solid fine particles and whiskers is 3 to 70% by volume based on the volume of the photocurable resin composition before containing them. The photocurable resin composition of any one item. It is a resin composition for optical three-dimensional modeling, The photocurable resin composition of any one of Claims 1-10. The method to manufacture a three-dimensional molded item by the optical three-dimensional modeling method using the photocurable resin composition of any one of Claims 1-11. (I) the following general formula (I);

(In the formula, a is 1 or 2, and when a is 1, R ₁ is a hydrogen atom or a methyl group, X

And when a is 2, one is a methyl group and the other is a hydrogen atom, or

And when b = 3, R ₃ is a hydrogen atom, a methyl group or an ethyl group, R ₂ is a hydrogen atom or a methyl group, and n is an integer from 0 to 20, but at the same time 0 and / or 4 The sum of n is 4 to 20, the average value of n is 1 to 4, and A is a trivalent substituent represented by the following general formula (II).

(In formula (II), Y is a C4-C20 alkyl group or a substituent selected from the following formula group (III).

In the formula, each R ₄ independently represents a hydrogen atom or a lower alkyl group, and e = 0 to 10, f = 0 to 4, and g = 0 to 4)))
Urethane acrylic compound represented by