JP4206820B2 - Manufacturing method of plastic lens - Google Patents

Description

（但し、式中Ｘは、硫黄原子又は酸素原子を表す。）
【００３７】
２つのエピスルフィド基のそれぞれの末端の硫黄原子相互が結合している場合には、分子内に１個以上のジスルフィド結合（Ｓ−Ｓ）を有し、且つエポキシ基及び／又はチオエポキシ基を有する化合物となる。
【００３８】
分子内に１個以上のエピスルフィド基を有する化合物としては、１，２−ビス（２，３−エピチオプロピルチオ）エタン、１，２−ビス（２，３−エピチオプロピルチオ）プロパン、１，３−ビス（２，３−エピチオプロピルチオ）プロパン、１，３−ビス（２，３−エピチオプロピルチオ）−２−メチルプロパン、１，４−ビス（２，３−エピチオプロピルチオ）ブタン、１，４−ビス（２，３−エピチオプロピルチオ）−２−メチルブタン、１，３−ビス（２，３−エピチオプロピルチオ）ブタン、１，５−ビス（２，３−エピチオプロピルチオ）ペンタン、１，５−ビス（２，３−エピチオプロピルチオ）−２−メチルペンタン、１，５−ビス（２，３−エピチオプロピルチオ）−３−チアペンタン、１，６−ビス（２，３−エピチオプロピルチオ）ヘキサン、１，６−ビス（２，３−エピチオプロピルチオ）−２−メチルヘキサン、１，８−ビス（２，３−エピチオプロピルチオ）−３，６−ジチアオクタン、１，２，３−トリス（２，３−エピチオプロピルチオ）プロパン、２，２−ビス（２，３−エピチオプロピルチオ）−１，３−ビス（２，３−エピチオプロピルチオメチル）プロパン、２，２−ビス（２、３−エピチオプロピルチオメチル）−１−（２，３−エピチオプロピルチオ）ブタン、１、５−ビス（２，３−エピチオプロピルチオ）−２−（２、３−エピチオプロピルチオメチル）−３−チアペンタン、１，５−ビス（２，３−エピチオプロピルチオ）−２，４−ビス（２、３−エピチオプロピルチオメチル）−３−チアペンタン、１−（２，３−エピチオプロピルチオ）−２，２−ビス（２，３−エピチオプロピルチオメチル）−４−チアヘキサン、１，５，６−トリス（２，３−エピチオプロピルチオ）−４−（２，３−エピチオプロピルチオメチル）−３−チアヘキサン、１，８−ビス（２，３−エピチオプロピルチオ）−４−（２，３−エピチオプロピルチオメチル）−３，６−ジチアオクタン、１，８−ビス（２，３−エピチオプロピルチオ）−４，５−ビス（２，３−エピチオプロピルチオメチル）−３，６−ジチアオクタン、１，８−ビス（２，３−エピチオプロピルチオ）−４，４−ビス（２，３−エピチオプロピルチオメチル）−３，６−ジチアオクタン、１，８−ビス（２，３−エピチオプロピルチオ）−２，５−ビス（２，３−エピチオプロピルチオメチル）−３，６−ジチアオクタン、１，８−ビス（２，３−エピチオプロピルチオ）−２，４，５−トリス（２，３−エピチオプロピルチオメチル）−３，６−ジチアオクタン、１，１，１−トリス｛［２−（２，３−エピチオプロピルチオ）エチル］チオメチル｝−２−（２，３−エピチオプロピルチオ）エタン、１，１，２，２−テトラキス｛［２−（２，３−エピチオプロピルチオ）エチル］チオメチル｝エタン、１，１１−ビス（２，３−エピチオプロピルチオ）−４，８−ビス（２，３−エピチオプロピルチオメチル）−３，６，９−トリチアウンデカン、１，１１−ビス（２，３−エピチオプロピルチオ）−４，７−ビス（２，３−エピチオプロピルチオメチル）−３，６，９−トリチアウンデカン、１，１１−ビス（２，３−エピチオプロピルチオ）−５，７−ビス（２，３−エピチオプロピルチオメチル）−３，６，９−トリチアウンデカン等の鎖状脂肪族の２，３−エピチオプロピルチオ化合物、及び、１，３−ビス（２，３−エピチオプロピルチオ）シクロヘキサン、１，４−ビス（２，３−エピチオプロピルチオ）シクロヘキサン、１，３−ビス（２，３−エピチオプロピルチオメチル）シクロヘキサン、１，４−ビス（２，３−エピチオプロピルチオメチル）シクロヘキサン、２，５−ビス（２，３−エピチオプロピルチオメチル）−１，４−ジチアン、２，５−ビス｛［２−（２，３−エピチオプロピルチオ）エチル］チオメチル｝−１，４−ジチアン、２，５−ビス（２，３−エピチオプロピルチオメチル）−２，５−ジメチル−１，４−ジチアン等の環状脂肪族の２，３−エピチオプロピルチオ化合物、及び、１，２−ビス（２，３−エピチオプロピルチオ）ベンゼン、１，３−ビス（２，３−エピチオプロピルチオ）ベンゼン、１，４−ビス（２，３−エピチオプロピルチオ）ベンゼン、１，２−ビス（２，３−エピチオプロピルチオメチル）ベンゼン、１，３−ビス（２，３−エピチオプロピルチオメチル）ベンゼン、１，４−ビス（２，３−エピチオプロピルチオメチル）ベンゼン、ビス［４−（２，３−エピチオプロピルチオ）フェニル］メタン、２，２−ビス［４−（２，３−エピチオプロピルチオ）フェニル］プロパン、ビス［４−（２，３−エピチオプロピルチオ）フェニル］スルフィド、ビス［４−（２，３−エピチオプロピルチオ）フェニル］スルフォン、４、４’−ビス（２，３−エピチオプロピルチオ）ビフェニル等の芳香族２，３−エピチオプロピルチオ化合物等を挙げることができる。これらの１種を単独で又は２種以上を併用して用いることができる。
【００３９】
分子内に１個以上のジスルフィド結合（Ｓ−Ｓ）を有し、且つエポキシ基及び／又はチオエポキシ基を有する化合物としては、例えば、ビス（２，３−エポキシプロピル）ジスルフィドやビス（２，３−エピチオプロピル）ジスルフィドなどの分子内に１個のジスルフィド結合を有する（チオ）エポキシ化合物、ビス（２，３−エピチオプロピルジチオ）メタン、ビス（２，３−エピチオプロピルジチオ）エタン、ビス（６，７−エピチオ−３，４−ジチアヘプタン）スルフィド、１，４−ジチアン−２，５−ビス（２，３−エピチオプロピルジチオメチル）、１，３−ビス（２，３−エピチオプロピルジチオメチル）ベンゼン、１，６−ビス（２，３−エピチオプロピルジチオメチル）−2−（２，３−エピチオプロピルジチオエチルチオ）−4−チアヘキサン、１，２，３−トリス（２，３−エピチオプロピルジチオ）プロパンなどの分子内に２つ以上のジスルフィド結合を有する（チオ）エポキシ化合物が挙げられる。これらの１種を単独で又は２種以上を併用して用いることができる。
【００４０】
本発明においては、重合性モノマーとして、これらの分子内に１個以上のエピスルフィド基を有する化合物と分子内に１個以上のジスルフィド結合（Ｓ−Ｓ）を有し、且つエポキシ基及び／又はチオエポキシ基を有する化合物のいずれか一方を使用できると共に、両者を併用して用いることができる。
【００４１】
本発明にかかるエピスルフィド等化合物を含有する原料組成物には、主に得られる樹脂の屈折率等の光学物性の調整や、耐衝撃性、比重等の諸物性を調整するためや、モノマーの粘度、その他の取扱い性を調整するためなど、樹脂の改良をする目的で、樹脂改質剤を加えることができる。
【００４２】
樹脂改質剤としては、上記分子内に１個以上のエピスルフィド基を有する化合物、チオール化合物、メルカプト有機酸類、有機酸類及び無水物類、アミノ酸、メルカプトアミン類、アミン類、（メタ）アクリレート類等を含むオレフィン類、エポキシ基、多価カルボン酸基、メタクリル基、アクリル基、アリル基、ビニル基、芳香族ビニル基、水酸基、イソシアネート基等の官能基を有する化合物が挙げられる。これらの樹脂改質剤はいずれも単独でも２種類以上を混合して使用しても良い。
【００４３】
硬化触媒としては３級アミン類、ホスフィン類、ルイス酸類、ラジカル硬化触媒類、カチオン硬化触媒類等が通常用いられる。硬化触媒の添加量は、原料組成物全体に対して０．００１〜１０重量％、より好ましくは０．０１〜５重量％の範囲である。硬化触媒の量がこの範囲より多いと硬化物の屈折率、耐熱性が低下し、また得られるレンズが著しく着色する場合がある。またこの範囲より少ないと十分に重合硬化せず耐熱性が十分に得られない場合がある。
【００４４】
また、高屈折率素材用の重合性モノマーとして、２個以上のイソシアネート基を有するポリイソシアネートと２個以上の活性水素を有する化合物とを主成分とする重合性モノマーを主成分とするものを例示することができる。
【００４５】
重合性モノマーを構成する２個以上のイソシアネート基を有するポリイソシアネートとしては、例えば、ｍ−キシリレンジイソシアネート、ｐ−キシリレンジイソシアネート、テトラクロロ−ｍ−キシリレンジイソシアネート、水添キシリレンジイソシアネート、水添ジフェニルメタンジイソシアネート、テトラメチルキシリレンジイソシアネート、２，５−ビス（イソシアネートメチル）ビシクロ［２．２．１］ヘプタン、２，６−ビス（イソシアネートメチル）ビシクロ［２．２．１］ヘプタン、３，８−ビス（イソシアネートメチル）トリシクロ［５．２．１、０^2、6］−デカン、３，９−ビス（イソシアネートメチル）トリシクロ［５．２．１．０^2、6］−デカン、４，８−ビス（イソシアネートメチル）トリシクロ［５．２．１、０^2、6］−デカン、４，９−ビス（イソシアネートメチル）トリシクロ［５．２．１、０^2、6］−デカン、ダイマー酸ジイソシアネート等のポリイソシアネート化合物及びそれらの化合物のアロファネート変性体、１，３−ビス（α，α−ジメチルイソシアネートメチル）ベンゼン、１，４−ビス（α，α−ジメチルイソシアネートメチル）ベンゼン、ヘキサメチレンジイソシアネート、イソホロンジイソシアネート、トリレンジイソシアネート、ジフェニルメタンジイソシアネート、ポリメリック型ジフェニルメタンジイソシアネート、トリジンジイソシアネート、ナフタレンジイソシアネート、４，４'−ジフェニルメタンジイソシアネート、ヘキサメチレンジイソシアネートのビウレット化反応物、ヘキサメチレンジイソシアネートとトリメチロールプロパンのアダクト生成物、４，４'−ジシクロヘキシルメタンジイソシアネート、イソシアヌレート変性体等が挙げられ、これらの化合物を単独で又は２種以上を混合して用いることができる。これらのポリイソシアネート中でも芳香族骨格等の環状骨格を有するものが好ましい。芳香族骨格のポリイソシアネートとしては、キシリレンジイソシアネートが好ましい。
【００４６】
また、重合性モノマーを構成する２個以上の活性水素を有する化合物としては、例えば２個以上の水酸基を有するポリオール、２個以上のチオール基を有するポリチオール、または１分子中に水酸基とチオール基を各々１個以上有する化合物を挙げることができる。
【００４７】
ポリオールとしては、例えば、エチレングリコール、ジエチレングリコール、プロピレングリコール、ジプロピレングリコール、ブチレングリコール、ネオペンチルグリコール、グリセリン、トリメチロールエタン、トリメチロールプロパン、ブタントリオール、１，２−メチルグルコサイド、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ソルビトール、エリスリトール、スレイトール、リビトール、アラビニトール、キシリトール、アリトール、マニトール、ドルシトール、イディトール、グリコール、イノシトール、ヘキサントリオール、トリグリセロール、ジグリペロール、トリエチレングリコール、ポリエチレングリコール、トリス（２−ヒドロキシエチル）イソシアヌレート、シクロブタンジオール、シクロペンタンジオール、シクロヘキサンジオール、シクロヘプタンジオール、シクロオクタンジオール、シクロヘキサンジメタノール、ヒドロキシプロピルシクロヘキサノール、トリシクロ〔５，２，１，０，２，６〕デカン−ジメタノール、ビシクロ〔４，３，０〕−ノナンジオール、ジシクロヘキサンジオール、トリシクロ〔５，３，１，１〕ドデカンジオール、ビシクロ〔４，３，０〕ノナンジメタノール、トリシクロ〔５，３，１，１〕ドデカン−ジエタノール、ヒドロキシプロピルトリシクロ〔５，３，１，１〕ドデカノール、スピロ〔３，４〕オクタンジオール、ブチルシクロヘキサンジオール、１，１'−ビシクロヘキシリデンジオール、シクロヘキサントリオール、マルチトール、ラクチトール等の脂肪族ポリオール、ジヒドロキシナフタレン、トリヒドロキシナフタレン、テトラヒドロキシナフタレン、ジヒドロキシベンゼン、ベンゼントリオール、ビフェニルテトラオール、ピロガロール、（ヒドロキシナフチル）ピロガロール、トリヒドロキシフェナントレン、ビスフェノールＡ、ビスフェノールＦ、キシリレングリコール、テトラブロムビスフェノールＡ等の芳香族ポリオール、ジ−（２−ヒドロキシエチル）スルフィド、１，２−ビス−（２−ヒドロキシエチルメルカプト）エタン、ビス（２−ヒドロキシエチル）ジスルフィド、１，４−ジチアン−２，５−ジオール、ビス（２，３−ジヒドロキシプロピル）スルフィド、テトラキス（４−ヒドロキシ−２−チアブチル）メタン、ビス（４−ヒドロキシフェニル）スルホン（商品名ビスフェノールＳ）、テトラブロモビスフェノールＳ、テトラメチルビスフェノールＳ、４，４'−チオビス（６−ｔｅｒｔ−ブチル−３−メチルフェノール）、１，３−ビス（２−ヒドロキシエチルチオエチル）−シクロヘキサンなどの硫黄原子を含有したポリオール等が挙げられる。
【００４８】
また、ポリチオールとしては、特に制限されないが、例えば下記式（１）で示される４−メルカプトメチル−３，６−ジチオ−１，８−オクタンジチオール、下記式（２）で示されるペンタエリスリトールテトラキス（３−メルカプトプロピオナート）、及び下記一般式（３）で示されるテトラチオールを例示することができる。
【００４９】
【化２】

【００５０】
この一般式（３）で示されるテトラチオールの具体例としては、例えば次のような構造式の化合物（Ａ）〜（Ｇ）を挙げることができる。
【００５１】
【化３】

【００５２】
その他のポリチオールとしては、例えば、ビス（２−メルカプトエチル）スルフィド、ジ（２−メルカプトエチル）エーテル、１，２−エタンジチオール、１，４−ブタンジチオール、エチレングリコールジチオグリコレート、トリメチロールプロパントリス（チオグリコレート）、ペンタエリスリトールテトラキス（２−メルカプトアセテート）、ジペンタエリスリトールヘキサキス（３−メルカプトプロピオナート）、ジペンタエリスリトールヘキサキス（２−メルカプトアセテート）、１，２−ジメルカプトベンゼン、４−メチル−１，２−ジメルカプトベンゼン、３，６−ジクロロ−１，２−ジメルカプトベンゼン、３，４，５，６−テトラクロロ−１，２−ジメルカプトベンゼン、Ｏ−キシリレンジチオール、ｍ−キシリレンジチオール、ｐ−キシリレンジチオール、及び１，３，５−トリス（３−メルカプトプロピル）イソシアヌレートなどが挙げられる。
【００５３】
また、１分子中に水酸基とチオール基を各々１個以上有する化合物としては、例えば、２−メルカプトエタノール、３−メルカプト−１，２−プロパンジオール、グルセリンジ（メルカプトアセテート）、１−ヒドロキシ−４−メルカプトシクロヘキサン、２，４−ジメルカプトフェノール、２−メルカプトハイドロキノン、４−メルカプトフェノール、１，３−ジメルカプト−２−プロパノール、２，３−ジメルカプト−１−プロパノール、１，２−ジメルカプト−１，３−ブタンジオール、ペンタエリスリトールトリス（３−メルカプトプロピオネート）、ペンタエリスリトールモノ（３−メルカプトプロピオネート）、ペンタエリスリトールビス（３−メルカプトプロピオネート）、ペンタエリスリトールトリス（チオグリコレート）、ペンタエリスリトールペンタキス（３−メルカプトプロピオネート）、ヒドロキシメチル−トリス（メルカプトエチルチオメチル）メタン、１−ヒドロキシエチルチオ−３−メルカプトエチルチオベンゼン、４−ヒドロキシ−４'−メルカプトジフェニルスルホン、２−（２−メルカプトエチルチオ）エタノール、ジヒドロキシエチルスルフィドモノ（３−メルカプトプロピオネート）、ジメルカプトエタンモノ（サルチレート）、ヒドロキシエチルチオメチルートリス（メルカプトエチルチオ）メタン等が挙げられる。
【００５４】
ポリイソシアネート化合物と活性水素の混合割合は、イソシアネート基（ＮＣＯ）と活性水素（Ｈ）の割合がＮＣＯ／Ｈ（モル比）＝０．５〜３．０、特に０．５〜１．５の範囲が好ましい。
【００５５】
なお、上記ポリイソシアネート、ポリオール、ポリチオール、分子中に水酸基とチオール基を各々１個以上有する化合物は、上記エピスルフィド等化合物に対して樹脂改質剤として併用するようにしてもよい。
【００５６】
また、硬化触媒としては、特に制限されないが、三級アミン、三級ホスフィン、又はジメチルスズジクロライドやジブチルスズジクロライド等のルイス酸が好ましい。硬化触媒の使用量は、一般的に重合性モノマーに対して０．０００５〜５重量％の範囲である。
【００５７】
本発明の原料組成物には、必要に応じて、鎖延長剤、架橋剤、光安定剤、特定紫外線以外の紫外線吸収剤、酸化防止剤、着色防止剤、染料、充填剤、内部離型剤などの種々の物質を添加してもよい。酸化防止剤や光安定剤の具体例としては、ヒンダードアミン系光安定剤、ヒンダードフェノール系酸化防止剤、ホスファイト系酸化防止剤、チオエーテル系酸化防止剤等を挙げることができる。
【００５８】
本発明では、紫外線吸収剤として、ベンゾトリアゾール系紫外線吸収剤を用いる。ベンゾトリアゾール系紫外線吸収剤は、上記原料組成物を構成する重合性モノマーに対する溶解性に優れ、高い紫外線吸収能を付与でき、しかも耐久性、吸収波長範囲が広いという特徴を有する。中でも、２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾールが、重合性モノマーに対する溶解性に特に優れ、白濁することなく、黄色く着色具合も小さい状態で、高い紫外線吸収能を付与することが容易であるため、好ましい。ベンゾトリアゾール系以外のベンゾフェノン系などの他の紫外線吸収剤を使用した場合には、紫外線吸収能が不十分であったり、重合硬化後に、紫外線吸収剤の析出、白濁といった現象によって、外観が不良になる等といった問題が発生する。
【００５９】
また、本発明では、粒径が揃っている特定紫外線吸収剤を用いることに特徴があり、５００μｍ以下、好ましくは２５０μｍ以下の粒径の特定紫外線吸収剤を用いる。粗大な粒径を含む特定紫外線吸収剤を用いると、溶解性が顕著に低下し、調合工程の時間が長くなり、生産性が低下する。
【００６０】
上記粒径の特定紫外線吸収剤を得るには、例えば、市販の特定紫外線吸収剤を篩分し、粒径の大きな部分を取り除き、粒径の小さいものを選別する方法がある。また、ボールミル等の粉砕機を用いて、市販品の特定紫外線吸収剤を粉砕し、必要により篩分して用いるようにしてもよい。
【００６１】
このような粒径の特定紫外線吸収剤の配合量は、上記重合性モノマーを主成分として硬化触媒その他の成分を加えたモノマー組成物１００重量部に対して０．５〜１．５重量部の範囲である。特定紫外線吸収剤をこの範囲で配合したプラスチックレンズは、波長４００ｎｍ以下の紫外線をほとんど吸収し、３８０〜３９０ｎｍ以下の紫外線をほぼ１００％吸収する紫外線吸収能を有する。すなわち、４００ｎｍの透過率は２０％以下であり、３８０〜３９０ｎｍ以下の透過率はほぼ０％である。配合量が０．５量部よりも小さい場合、紫外線吸収能が十分に発現されない。また１．５重量部を超える場合、レンズが著しく黄色に着色し、かつ白濁によりレンズの外観が不良となる。
【００６２】
原料組成物の調合工程は、上記重合性モノマー、硬化触媒、特定紫外線吸収剤その他の成分を上記配合量で混合して原料組成物を調製する工程である。上記エピスルフィド等化合物は、比較的不安定であり、調合工程では、−１０℃〜３０℃の温度範囲にすることが望ましいとされている。この低い温度での特定紫外線吸収剤のエピスルフィド等化合物に対する溶解速度は高濃度に溶解させることもあって遅い。粒径を調整しない従来の特定紫外線吸収剤を完全に溶解させるには、３時間程度の攪拌時間を必要としていた。粒径を小さく揃えた特定紫外線吸収剤を用いると、３０分〜１時間程度の攪拌時間で完全に溶解させることが可能となった。調合時間の短縮により、製造設備の効率化が可能となり、生産性が顕著に向上した。また、調合後に行われる原料組成物のフィルタによる濾過の際に、溶けずに残った特定紫外線吸収剤によるフィルタの目詰まりのおそれがなくなる。
【００６３】
調合工程における調合の順序に制限はない。例えば、重合性モノマーに紫外線吸収剤その他の成分を溶解させた後、硬化触媒を最後に添加する方法を採用することができる。
【００６４】
調合工程後、原料組成物を重合硬化させる重合工程を行う。重合工程は、原料組成物を例えばガスケットまたはテープによって側面が保持された２枚のガラス型よりなる成形モールド内に注入し、この成形モールドを所定の温度に調節できる雰囲気中で原料組成物を硬化させ、成形モールドのキャビティの形状が転写されたプラスチックレンズを得る注型重合法が用いられる。
【００６５】
プラスチックレンズの重合成形では、レンズの両面が成形モールドからの転写で所定の光学面に仕上げられたフィニッシュレンズを製造する場合と、片面が成形モールドからの転写で光学面に仕上げられ、反対側の面が研磨加工により光学面に削られるセミフィニッシュレンズを製造する場合がある。
【００６６】
原料組成物の重合温度条件として、例えば初期重合として１０〜４０℃で４〜１０時間、その温度から最高温度の１００〜１４０℃まで３〜７時間で上昇させ、その温度を１〜３時間維持し、３〜５時間かけて常温に冷却し、全体で１５〜２５時間の重合時間を要するという加熱パターンが一般的である。
【００６７】
かかる重合温度の調節は、例えば重合炉の中に成形モールドを配置し、重合炉内の雰囲気温度の温度調節により行われる。
【００６８】
エピスルフィド等化合物を重合性モノマーの主成分として用いた場合は、初期重合の段階では２０±１５℃の温度を５時間以上、好ましくは５０時間以内、特に好ましくは８〜２４時間保つようにして原料組成物をゲル化する。この低温の初期重合温度条件で重合反応を進めてゲル化を行うことにより、光学的歪みの発生を可及的に抑制することができ、歩留まりを向上させることができる。初期重合温度が上記温度より低いと、ゲル化までの時間がかかりすぎて製造上不利である。また、初期重合温度が高過ぎると、光学的歪みが発生し易くなる。初期重合時間が短すぎるとゲル化が不十分となり、光学的歪みが発生し易くなる。一方、初期重合時間を長くしても、それ以上重合反応がほとんど進行せず、生産効率の面から好ましくない場合がある。上記温度範囲内で一定の温度とする場合が通常であるが、上記温度範囲内で温度を変化させるようにしても良い。
【００６９】
エピスルフィド等化合物を重合性モノマーとして用いる場合は、重合時の最高温度を１２５℃〜１４０℃とする。最高温度が低いと、レンズの度数は重合後の１回のアニールでは安定せず、その後の熱処理によってレンズ度数は変化し続ける現象を示す場合がある。一方、重合時の最高温度が１４０℃を越える場合は、重合後のレンズ色調において黄色が強くなり、無色透明が望まれる眼鏡レンズ用としては、使用できなくなる場合がある。
【００７０】
重合炉から成形モールドを取り出し、成形モールドを分解して硬化したプラスチックレンズを取り出すことができる。
【００７１】
成形モールドから取り出したプラスチックレンズを再加熱しアニール処理を行うことは、レンズ度数の安定化やレンズの光学歪みを取り除くために、好ましい処理方法である。このときの処理温度は７０℃〜１６０℃であり、好ましくは８０℃〜１４０℃である。また処理時間は１０分〜６時間であり、好ましくは１時間〜３時間である。
【００７２】
重合成形されたプラスチックレンズがフィニッシュレンズの場合は、研磨加工せずに、染色、ハードコート膜の形成、反射防止膜の形成などの処理工程を必要により経て最終的なプラスチックレンズとなる。
【００７３】
重合成形されたプラスチックレンズがセミフィニッシュレンズの場合は、一方の面を所定の光学面に削る研磨工程を行う。研磨工程後、染色、ハードコート膜の形成、反射防止膜の形成などの処理工程を必要により経て最終的なプラスチックレンズとなる。
【００７４】
このようにして得られたプラスチックレンズは、紫外線吸収剤として２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾールなどのベンゾトリアゾール系紫外線吸収剤を０．５〜１．５重量部配合しているため、紫外線吸収能に優れ、眼を紫外線から保護することができる。
【００７５】
【実施例】
実施例および比較例で使用する化合物の略称は以下の通りである。
エピスルフィド等化合物
Ａ−１：ビス−（２，３−エピチオプロピル）ジスルフィド
チオール化合物
Ｂ−１：４，８ｏｒ４，７ｏｒ５，７−ジメルカプトメチル−１，１１−ジメルカプト−３，６，９−トリチアウンデカン
Ｂ−２：ビス（２−メルカプトエチル）スルフィド
ポリイソシアネート化合物
Ｃ−１：ｍ−キシリレンジイソシアネート
紫外線吸収剤
Ｓ−７０１：２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾール（商品名 シーソーブ７０１ シプロ化成株式会社製、市販品）
Ｓ−７０１Ｐ：上記Ｓ−７０１の市販品を目開き２５０μｍの篩で篩分し、目開き２５０μｍの篩を通過したもの。
Ｓ−７０６：２−（２Ｈ−ベンゾトリアゾール−２−イル−）−４−メチル−６−（３，４，５，６−テトラヒドロフタルイミジルメチル）フェノール（商品名シーソーブ７０６ シプロ化成株式会社製）
Ｓ−７０７：２−（２−ヒドロキシ−４−オクチルオキシフェニル）−２Ｈ−ベンゾトリアゾール（商品名 シーソーブ７０７ シプロ化成株式会社製）
Ｓ−７０９：２−（２−ヒドロキシ−５−ｔ−オクチルフェニル）−２Ｈ−ベンゾトリアゾール（商品名 シーソーブ７０９ シプロ化成株式会社製）
Ｔ−２３４：２−（２−ヒドロキシ−３，５−ビス（α、α'ジメチルベンジル）フェニル）−２Ｈ−ベンゾトリアゾール（商品名 チヌビン２３４ チバ・スペシャルティ・ケミカルズ株式会社製）
【００７６】
（実施例１）
レンズ原料組成物として、表１に示す化合物を表１に示す組成比で温度２０℃で混合した後、紫外線吸収剤として表１に示す化合物を、表１に示す量添加し、１時間攪拌した時点で原料組成物の外観を目視にて確認し、紫外線吸収剤の溶解性を下記の基準で評価した。
【００７７】
＜溶解性＞
○：溶け残った紫外線吸収剤の粒子が見られない。
△：少量の紫外線吸収剤の粒子が溶け残り、モノマー中に分散している。
×：大部分の紫外線吸収剤粒子が溶け残っている。
【００７８】
溶け残っている場合には更に十分に撹拌して、完全に溶解させた。その後、触媒としてＮ,Ｎ−ジメチルシクロヘキシルアミン０．０２ｇ、Ｎ,Ｎ−ジシクロヘキシルメチルアミン０．１０ｇを添加した後、２０℃で十分に撹拌して均一液とした。ついでこの組成物を中心厚１．２ｍｍとしたプラスチックレンズ用ガラスモールド中に注入し、大気重合炉中で３０℃から１２０℃まで２４時間かけて昇温を行い、重合硬化させた。その後ガラスモールドよりレンズを離型し、１３０℃で２時間加熱してアニール処理を行った。
【００７９】
このようにして製造したプラスチックレンズを、下記の方法で品質評価を行った。その結果を表２に示す。
【００８０】
＜屈折率＞
アッベ屈折率計により２０℃でＤ線（５８９．３ｎｍ）の屈折率を測定した。
【００８１】
＜アッベ数＞
アッベ屈折率計により２０℃でＤ線（５８９．３ｎｍ）のアッベ数を測定した。
【００８２】
＜紫外線吸収能＞
分光光度計Ｕ−３５００（日立製）を用いて、レンズ中心部（レンズ厚が一番薄くなる部分）の透過スペクトルを測定し、波長４００ｎｍにおける透過率を求めた。この結果をもとに以下のように分類した。
○：紫外線がほぼ吸収されている（波長４００ｎｍ透過率 ２０％以下）。
△：紫外線の吸収が不十分である（波長４００ｎｍ透過率 ２０〜４０％）。
×：紫外線がほとんど吸収されていない（波長４００ｎｍ透過率 ４０％以上）。
【００８３】
＜耐光性＞
ＪＩＳ Ｂ ７７５３に規定するサンシャインカーボンアーク灯式耐候性試験機を使用し、８０時間加速試験後レンズの色調（ｂ*）を測定し、初期と比べてｂ*の変化量が２未満のものを○、２以上のものを×とした。
【００８４】
＜色調＞
目視により得られたレンズの色調を目視で観察し、黄色さのレベルによって以下のように分類した。
○：良好
△：レンズが若干黄色化している。もしくは若干紫外線吸収剤の析出が見られる。
×：レンズが著しく黄色化している。もしくは著しく紫外線吸収剤の析出が見られる。
【００８５】
＜白濁＞
レンズのコバ部分から光をあてることによって、レンズの白濁を目視で観察し、白濁のレベルによって以下のように分類した。
○：白濁は見られない。
△：薄い白濁が見られる。
×：濃い白濁が見られる。
【００８６】
（実施例２）
原料組成を表１に示すように変更した以外は、実施例１と同条件でレンズを作製し、実施例１と同様の品質評価を行った。評価結果を表２に示す。
【００８７】
（実施例３）
レンズ原料組成物として表１に示す化合物を表１に示す組成比で温度２０℃で混合した後、紫外線吸収剤として表１に示す量添加し、１時間撹拌した時点で原料組成物の外観を目視にて確認し、紫外線吸収剤の溶解性を実施例１と同様の基準で評価した。
【００８８】
溶け残っている場合には更に十分に撹拌して完全に溶解させた。その後、内部離型剤０．７５ｇを添加して撹拌した後に、触媒としてジブチルスズジクロライド０．０３ｇを添加し、撹拌して溶解させた後、５ｍｍＨｇの真空下で６０分脱気を行った。ついでこの組成物を、中心厚１．２ｍｍとしたプラスチックレンズ用ガラスモールド中に注入し、大気重合炉中で３０℃から１２０℃まで１７時間かけて昇温を行い、重合硬化させた。その後ガラスモールドよりレンズを離型し、１２０℃で２時間加熱してアニールを行った。
【００８９】
このようにして製造したプラスチックレンズを実施例１と同様の方法で品質評価を行い、その結果を表２に示す。
【００９０】
（比較例１〜１２）
原料組成と、紫外線吸収剤の種類と添加量を、表１に示すように変更した以外は、実施例１と同条件でレンズを作製し、実施例１と同様の品質評価を行った。評価結果を表２に示す。
【００９１】
【表１】

【００９２】
【表２】

【００９３】
表２の結果より、篩分して粒径の大きなものを除いていない２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾールを使用した場合（比較例１、２、９）、溶解性が悪い。紫外線吸収剤の配合量が本発明の範囲より少ない場合（比較例３、１０）、紫外線吸収能が劣り、配合量が多すぎる場合（比較例４、１１）は、白濁が生じる。２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾール以外の紫外線吸収剤を使用した場合（比較例５〜８、１２）、白濁が生じ、紫外線吸収能の低下や、レンズが著しく黄色化し、もしくは著しく紫外線吸収剤の析出が見られる。
【００９４】
これに対して、紫外線吸収剤として２５０μｍより大きな粒径のものを除いた２−（２−ヒドロキシ−５−メチルフェニル）−２Ｈ−ベンゾトリアゾールを本発明の範囲の配合量で使用した場合は、溶解性が良好で、１時間の攪拌時間で溶解し、紫外線吸収能に優れ、白濁、着色等も発生しないことが認められる。
【００９５】
【発明の効果】
本発明のプラスチックレンズの製造方法によれば、原料組成物の調合時間を短縮して生産性を向上させることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a plastic lens, and more particularly, to a method for manufacturing a plastic lens capable of manufacturing a plastic lens excellent in ultraviolet absorbing ability with high productivity.
[0002]
[Prior art]
It is known that ultraviolet rays having a wavelength of 400 nm or less, which are contained in sunlight, adversely affect the cornea and crystalline lens of the eye. Exposure to sunlight in places with a large amount of ultraviolet rays, such as the sea or mountains, can easily cause keratitis. In addition, the accumulation of ultraviolet rays may cause cataracts in the lens. For this reason, it is required to impart an ultraviolet absorbing ability to spectacle lenses, particularly plastic lenses that are in great demand in recent years.
[0003]
In order to impart ultraviolet absorbing ability to a plastic lens, a method generally called a kneading method is known. In the kneading method, an ultraviolet absorber is mixed and dissolved in a liquid containing a polymerizable monomer and a polymerization initiator / curing catalyst to prepare a raw material composition, which is then injected into a mold for polymerization and cured to form a lens fabric. This is a method of imparting ultraviolet absorbing ability to itself.
[0004]
In the kneading method, it is necessary to dissolve the ultraviolet absorber in the polymerizable monomer at a high concentration. Therefore, even if the UV absorber does not dissolve in the monomer, and even if it is dissolved before polymerization curing, it will precipitate on the entire lens after polymerization curing, or the entire lens will become cloudy or colored yellow, etc. There is a problem that becomes bad.
[0005]
In recent years, demands for further weight reduction and thinning of plastic lenses have increased, and development of optical materials having a higher refractive index than before has been actively conducted. In Patent Documents 1 to 3 shown below, as an optical material excellent in the balance between a high refractive index and a high Abbe number, (1) a compound having one or more episulfide groups in the molecule, (2) one or more in the molecule A compound having a disulfide bond (S—S) and having an epoxy group and / or a thioepoxy group (hereinafter, these may be collectively referred to as a compound such as episulfide) has been proposed.
[0006]
In Patent Documents 5 and 6 shown below, a plastic lens having a thiourethane structure, which is obtained by a reaction between a polyisocyanate compound and a compound having an active hydrogen group such as a polythiol compound, is proposed.
[0007]
As a result of studies conducted by the present applicant to impart an ultraviolet absorbing ability to a plastic lens made of a compound such as episulfide as a raw material, as shown in Patent Document 4, it is dissolved in a composition containing a compound such as episulfide as a main component. 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole (hereinafter, abbreviated as a specific ultraviolet absorber) in view of properties, ultraviolet absorbing ability, durability, wide absorption wavelength range, etc. ) Was found to be optimal. In addition, as the addition amount at this time, by adding 0.5 to 1.5 parts by weight of a specific ultraviolet absorber with respect to 100 parts by weight of a monomer composition containing a compound such as episulfide as a main component, lens appearance defects are reduced. It has also been found that an excellent ultraviolet absorbing ability can be imparted without causing it.
[0008]
In addition, as a result of study for imparting ultraviolet absorbing ability to a plastic lens made of a polyisocyanate compound and a polythiol compound as a raw material, the present applicant has found that a benzotriazole-based ultraviolet absorber is, as shown in Patent Document 7, It is found to be optimal.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-110979
[Patent Document 2]
Japanese Patent Laid-Open No. 9-255781
[Patent Document 3]
JP 11-322930 A
[Patent Document 4]
JP 2002-156503 A
[Patent Document 5]
Japanese Patent Publication No. 4-58489
[Patent Document 6]
JP-A-5-148340
[Patent Document 7]
JP-A-11-271501
[0010]
[Problems to be solved by the invention]
However, compounds such as episulfide are relatively unstable, and the temperature when blended with a curing catalyst or the like must be set to room temperature or lower. For this reason, when the specific ultraviolet absorber is dissolved in the monomer composition at a high concentration, there is a problem that the dissolution rate of the specific ultraviolet absorber is slow, the preparation takes a lot of time, and the productivity is poor.
[0011]
The same problem also occurs in the case of thiourethane plastic lenses using polyisocyanate compounds and polythiol compounds as raw materials, and the dissolution rate is slow when dissolving UV absorbers in monomer compositions at high concentrations. There is a problem that the preparation takes a lot of time and the productivity is poor.
[0012]
This invention is made | formed in view of the said situation, The preparation time of the raw material composition which dissolves the quantity of the ultraviolet absorber which can provide the capability which can fully absorb an ultraviolet-ray can be shortened, and productivity can be improved. An object is to provide a method for producing a plastic lens.
[0013]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventor has found that a general benzotriazole-based ultraviolet absorber is a white to light yellow crystalline powder, but is not a powder having a uniform particle size but a relatively large particle size. Focusing on the inclusion of particle sizes. In particular, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole has a relatively large particle size and a large number. Therefore, the present inventor removed a large particle size with a sieve and tried to dissolve it with a particle size smaller than 500 μm, and the solubility was unexpectedly improved. It was found that the dissolution time was dramatically reduced from 30 minutes to 1 hour.
[0014]
In addition, since the ultraviolet absorber usually dislikes dust during operation, a large particle size is required, but in the present invention, a small particle size is selected on the contrary.
[0015]
Among ultraviolet absorbers, benzotriazole-based ultraviolet absorbers have good solubility in the raw material monomer for plastic lenses, and it is easy to impart ultraviolet absorbing performance to plastic lenses while maintaining a small yellow color. Among the benzotriazole-based ultraviolet absorbers, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole is preferable, and particularly excellent in solubility, hardly clouded, and has a large effect of small coloring and high. Excellent for imparting ultraviolet absorption ability.
[0016]
Among the benzotriazole-based ultraviolet absorbers, preferably 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole is a raw material monomer for plastic lenses, such as episulfide described in Patent Documents 1 to 3 above. The compound is particularly excellent in solubility, hardly cloudy, has little colorability, and is excellent in imparting high ultraviolet absorption ability.
[0017]
In addition, benzotriazole-based ultraviolet absorbers, particularly preferably 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, is used as a polymerizable monomer in addition to compounds such as episulfide. Adds UV-absorbing performance to plastic lenses while maintaining good solubility in the compounds with two or more polyisocyanates and compounds with two or more active hydrogens shown. Easy to do. It has excellent solubility, hardly becomes cloudy, has little colorability, and can impart high ultraviolet absorption ability.
[0018]
As the polyisocyanate, those having a cyclic skeleton are preferable. An aromatic skeleton is preferred as the cyclic skeleton, and xylylene diisocyanate is preferred as the polyisocyanate having an aromatic skeleton.
[0019]
When the temperature of the raw material composition in the blending step is within a temperature range of −10 to 30 ° C. which is difficult to dissolve, the effect of improving the solubility by making the particle size of the ultraviolet absorber small is remarkable.
[0020]
Therefore, the invention of claim 1 Removing a benzotriazole ultraviolet absorber having a particle size larger than 500 μm; , With respect to 100 parts by weight of a monomer composition containing a polymerizable monomer as a main component The particle diameter obtained in the above process is 500 μm or less. A method for producing a plastic lens, comprising: a raw material composition preparation step for dissolving 0.5 to 1.5 parts by weight of an nzotriazole-based ultraviolet absorber; and a polymerization step for polymerizing and curing the raw material composition. I will provide a.
[0021]
The invention according to claim 2 is the method for producing a plastic lens according to claim 1, wherein the ultraviolet absorber is 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole. A method of manufacturing a plastic lens is provided.
[0022]
The invention according to claim 3 is the plastic lens manufacturing method according to claim 1 or 2, wherein the polymerizable monomer contains a compound having at least one episulfide group in one molecule. A manufacturing method is provided.
[0023]
The invention according to claim 4 is the method for producing a plastic lens according to claim 1 or 2, wherein the polymerizable monomer has one or more disulfide bonds (SS) in one molecule, and an epoxy group. And / or a compound having a thioepoxy group, and a method for producing a plastic lens.
[0024]
The invention according to claim 5 is the method for producing a plastic lens according to claim 1 or 2, wherein the polymerizable monomer is a polyisocyanate having two or more isocyanate groups, and a compound having two or more active hydrogens. The manufacturing method of the plastic lens characterized by having as a main component is provided.
[0025]
The invention according to claim 6 provides the method for producing a plastic lens according to claim 5, wherein the compound having two or more active hydrogens is polythiol.
[0026]
The invention according to claim 7 provides the method for producing a plastic lens according to claim 5 or 6, wherein the polyisocyanate has an aromatic skeleton as a cyclic skeleton.
[0027]
The invention according to claim 8 provides the method for producing a plastic lens according to claim 7, wherein the polyisocyanate having an aromatic skeleton as the cyclic skeleton is xylylene diisocyanate. .
[0028]
The invention according to claim 9 is the plastic lens manufacturing method according to any one of claims 1 to 8, wherein the temperature of the monomer composition in the preparation step is in the range of -10 ° C to 30 ° C. A method for manufacturing a lens is provided.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, although the embodiment of the manufacturing method of the plastic lens of the present invention is described, the present invention is not limited to the following embodiment.
[0030]
As described above, the method for producing a plastic lens of the present invention is a raw material for dissolving a benzotriazole-based ultraviolet absorber having a particle size of 500 μm or less as an ultraviolet absorber in a monomer composition containing a polymerizable monomer as a main component. It has the preparation process of a composition, and the superposition | polymerization process of polymerizing and hardening a raw material composition.
[0031]
The ultraviolet absorber used in the present invention is a benzotriazole-based ultraviolet absorber. Among them, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole has particularly good solubility in raw material monomers and is cloudy. It is preferable in that it is difficult to impart, and it is easy to impart a high ultraviolet absorbing ability.
[0032]
The polymerizable monomer used in the present invention is not limited as long as it is used as a raw material for plastic lenses, but a high refractive index material developed in recent years is from the viewpoint of the solubility of a specific ultraviolet absorber and the like. Can be preferably used.
[0033]
Examples of the polymerizable monomer for the high refractive index material include (1) a compound having one or more episulfide groups in the molecule described in Patent Documents 1 to 3, and (2) one or more in the molecule. And compounds having a disulfide bond (SS) and having an epoxy group and / or a thioepoxy group (compounds such as episulfide).
[0034]
A compound such as episulfide is a material having a very high optical performance because its cured product has a high refractive index and a high Abbe number.
[0035]
The episulfide group is represented by the following formula.
[0036]
[Chemical 1]

(In the formula, X represents a sulfur atom or an oxygen atom.)
[0037]
A compound having one or more disulfide bonds (SS) in the molecule and having an epoxy group and / or a thioepoxy group when sulfur atoms at the respective terminals of two episulfide groups are bonded to each other It becomes.
[0038]
Examples of the compound having one or more episulfide groups in the molecule include 1,2-bis (2,3-epithiopropylthio) ethane, 1,2-bis (2,3-epithiopropylthio) propane, , 3-bis (2,3-epithiopropylthio) propane, 1,3-bis (2,3-epithiopropylthio) -2-methylpropane, 1,4-bis (2,3-epithiopropyl) Thio) butane, 1,4-bis (2,3-epithiopropylthio) -2-methylbutane, 1,3-bis (2,3-epithiopropylthio) butane, 1,5-bis (2,3 -Epithiopropylthio) pentane, 1,5-bis (2,3-epithiopropylthio) -2-methylpentane, 1,5-bis (2,3-epithiopropylthio) -3-thiapentane, , 6-Bis (2,3-epithio (Lopylthio) hexane, 1,6-bis (2,3-epithiopropylthio) -2-methylhexane, 1,8-bis (2,3-epithiopropylthio) -3,6-dithiaoctane, 1,2 , 3-tris (2,3-epithiopropylthio) propane, 2,2-bis (2,3-epithiopropylthio) -1,3-bis (2,3-epithiopropylthiomethyl) propane, 2,2-bis (2,3-epithiopropylthiomethyl) -1- (2,3-epithiopropylthio) butane, 1,5-bis (2,3-epithiopropylthio) -2- ( 2,3-epithiopropylthiomethyl) -3-thiapentane, 1,5-bis (2,3-epithiopropylthio) -2,4-bis (2,3-epithiopropylthiomethyl) -3- Thiapentane, 1- (2,3-epithio Propylthio) -2,2-bis (2,3-epithiopropylthiomethyl) -4-thiahexane, 1,5,6-tris (2,3-epithiopropylthio) -4- (2,3-epi Thiopropylthiomethyl) -3-thiahexane, 1,8-bis (2,3-epithiopropylthio) -4- (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8- Bis (2,3-epithiopropylthio) -4,5-bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -4,4-bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -2,5-bis (2,3- Epithiopropylthiomethyl) -3,6-di Thiaoctane, 1,8-bis (2,3-epithiopropylthio) -2,4,5-tris (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,1,1-tris {[2- (2,3-epithiopropylthio) ethyl] thiomethyl} -2- (2,3-epithiopropylthio) ethane, 1,1,2,2-tetrakis {[2- (2,3 -Epithiopropylthio) ethyl] thiomethyl} ethane, 1,11-bis (2,3-epithiopropylthio) -4,8-bis (2,3-epithiopropylthiomethyl) -3,6,9 -Trithiaundecane, 1,11-bis (2,3-epithiopropylthio) -4,7-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1, 11-bis (2,3-epithiopropylthio ) -5,7-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane and the like chain aliphatic 2,3-epithiopropylthio compounds and 1,3 -Bis (2,3-epithiopropylthio) cyclohexane, 1,4-bis (2,3-epithiopropylthio) cyclohexane, 1,3-bis (2,3-epithiopropylthiomethyl) cyclohexane, 1 , 4-bis (2,3-epithiopropylthiomethyl) cyclohexane, 2,5-bis (2,3-epithiopropylthiomethyl) -1,4-dithiane, 2,5-bis {[2- ( 2,3-epithiopropylthio) ethyl] thiomethyl} -1,4-dithiane, 2,5-bis (2,3-epithiopropylthiomethyl) -2,5-dimethyl-1,4-dithiane, etc. Cycloaliphatic 2, -Epithiopropylthio compound, 1,2-bis (2,3-epithiopropylthio) benzene, 1,3-bis (2,3-epithiopropylthio) benzene, 1,4-bis (2 , 3-epithiopropylthio) benzene, 1,2-bis (2,3-epithiopropylthiomethyl) benzene, 1,3-bis (2,3-epithiopropylthiomethyl) benzene, 1,4- Bis (2,3-epithiopropylthiomethyl) benzene, bis [4- (2,3-epithiopropylthio) phenyl] methane, 2,2-bis [4- (2,3-epithiopropylthio) Phenyl] propane, bis [4- (2,3-epithiopropylthio) phenyl] sulfide, bis [4- (2,3-epithiopropylthio) phenyl] sulfone, 4,4′-bis (2,3 -Epichi And the like propylthio) aromatic such as biphenyl 2,3-epithiopropylthio compounds. These 1 type can be used individually or in combination of 2 or more types.
[0039]
Examples of the compound having one or more disulfide bonds (SS) in the molecule and having an epoxy group and / or a thioepoxy group include bis (2,3-epoxypropyl) disulfide and bis (2,3 -(Thiothiopropyl) disulfide (thio) epoxy compound having one disulfide bond in the molecule, bis (2,3-epithiopropyldithio) methane, bis (2,3-epithiopropyldithio) ethane, Bis (6,7-epithio-3,4-dithiaheptane) sulfide, 1,4-dithian-2,5-bis (2,3-epithiopropyldithiomethyl), 1,3-bis (2,3-epi Thiopropyldithiomethyl) benzene, 1,6-bis (2,3-epithiopropyldithiomethyl) -2- (2,3-epithiopropyldithioethylthio) Examples include (thio) epoxy compounds having two or more disulfide bonds in the molecule, such as -4-thiahexane and 1,2,3-tris (2,3-epithiopropyldithio) propane. These 1 type can be used individually or in combination of 2 or more types.
[0040]
In the present invention, as a polymerizable monomer, a compound having one or more episulfide groups in these molecules and one or more disulfide bonds (SS) in the molecule, and an epoxy group and / or a thioepoxy Either one of the compounds having a group can be used, and both can be used in combination.
[0041]
In the raw material composition containing a compound such as episulfide according to the present invention, the viscosity of the monomer is mainly used to adjust optical properties such as the refractive index of the resin obtained and to adjust various physical properties such as impact resistance and specific gravity. A resin modifier can be added for the purpose of improving the resin, for example, to adjust other handling properties.
[0042]
Examples of the resin modifier include compounds having one or more episulfide groups in the molecule, thiol compounds, mercapto organic acids, organic acids and anhydrides, amino acids, mercaptoamines, amines, (meth) acrylates, etc. And compounds having functional groups such as epoxy groups, polyvalent carboxylic acid groups, methacryl groups, acrylic groups, allyl groups, vinyl groups, aromatic vinyl groups, hydroxyl groups, and isocyanate groups. Any of these resin modifiers may be used alone or in admixture of two or more.
[0043]
As the curing catalyst, tertiary amines, phosphines, Lewis acids, radical curing catalysts, cationic curing catalysts and the like are usually used. The addition amount of the curing catalyst is in the range of 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, based on the entire raw material composition. If the amount of the curing catalyst is more than this range, the refractive index and heat resistance of the cured product are lowered, and the resulting lens may be markedly colored. On the other hand, if the amount is less than this range, the polymer may not be sufficiently cured and heat resistance may not be sufficiently obtained.
[0044]
Examples of the polymerizable monomer for a high refractive index material include a polymerizable monomer mainly composed of a polyisocyanate having two or more isocyanate groups and a compound having two or more active hydrogens. can do.
[0045]
Examples of the polyisocyanate having two or more isocyanate groups constituting the polymerizable monomer include m-xylylene diisocyanate, p-xylylene diisocyanate, tetrachloro-m-xylylene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenation. Diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, 2,5-bis (isocyanatemethyl) bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) bicyclo [2.2.1] heptane, 3,8 -Bis (isocyanatomethyl) tricyclo [5.2.1,0 ^{2, 6} ] -Decane, 3,9-bis (isocyanatomethyl) tricyclo [5.2.1.0] ^{2, 6} ] -Decane, 4,8-bis (isocyanatomethyl) tricyclo [5.2.1,0 ^{2, 6} ] -Decane, 4,9-bis (isocyanatomethyl) tricyclo [5.2.1,0 ^{2, 6} ] -Polyisocyanate compounds such as decane and dimer acid diisocyanate, and allophanate-modified products of these compounds, 1,3-bis (α, α-dimethylisocyanatomethyl) benzene, 1,4-bis (α, α-dimethylisocyanatemethyl) ) Benzene, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate biuretation reaction product, hexamethylene diisocyanate and tril An adduct product of methylolpropane, 4,4′-dicyclohexylmethane diisocyanate, The isocyanurate modified body etc. are mentioned, These compounds can be used individually or in mixture of 2 or more types. Among these polyisocyanates, those having a cyclic skeleton such as an aromatic skeleton are preferable. As the polyisocyanate having an aromatic skeleton, xylylene diisocyanate is preferable.
[0046]
Examples of the compound having two or more active hydrogens constituting the polymerizable monomer include a polyol having two or more hydroxyl groups, a polythiol having two or more thiol groups, or a hydroxyl group and a thiol group in one molecule. The compound which has one or more each can be mentioned.
[0047]
Examples of the polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, butanetriol, 1,2-methylglucoside, pentaerythritol, diethylene Pentaerythritol, tripentaerythritol, sorbitol, erythritol, threitol, ribitol, arabinitol, xylitol, allitol, mannitol, dolcitol, iditol, glycol, inositol, hexanetriol, triglycerol, diglycerol, triethylene glycol, polyethylene glycol, tris (2- Hydroxyethyl) isocyanurate, cyclobutanedio , Cyclopentanediol, cyclohexanediol, cycloheptanediol, cyclooctanediol, cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo [5,2,1,0,2,6] decane-dimethanol, bicyclo [4,3 , 0] -nonanediol, dicyclohexanediol, tricyclo [5,3,1,1] dodecanediol, bicyclo [4,3,0] nonanedimethanol, tricyclo [5,3,1,1] dodecane-diethanol, Aliphatic acids such as hydroxypropyltricyclo [5,3,1,1] dodecanol, spiro [3,4] octanediol, butylcyclohexanediol, 1,1'-bicyclohexylidenediol, cyclohexanetriol, maltitol, lactitol Polyol Fragrances such as dihydroxynaphthalene, trihydroxynaphthalene, tetrahydroxynaphthalene, dihydroxybenzene, benzenetriol, biphenyltetraol, pyrogallol, (hydroxynaphthyl) pyrogallol, trihydroxyphenanthrene, bisphenol A, bisphenol F, xylylene glycol, tetrabromobisphenol A Group polyol, di- (2-hydroxyethyl) sulfide, 1,2-bis- (2-hydroxyethyl mercapto) ethane, bis (2-hydroxyethyl) disulfide, 1,4-dithian-2,5-diol, bis (2,3-dihydroxypropyl) sulfide, tetrakis (4-hydroxy-2-thiabutyl) methane, bis (4-hydroxyphenyl) sulfone (trade name bisphenol) S), tetrabromobisphenol S, tetramethylbisphenol S, sulfur such as 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,3-bis (2-hydroxyethylthioethyl) -cyclohexane Examples thereof include polyols containing atoms.
[0048]
In addition, the polythiol is not particularly limited. For example, 4-mercaptomethyl-3,6-dithio-1,8-octanedithiol represented by the following formula (1), pentaerythritol tetrakis represented by the following formula (2) ( 3-mercaptopropionate) and tetrathiol represented by the following general formula (3) can be exemplified.
[0049]
[Chemical formula 2]

[0050]
Specific examples of the tetrathiol represented by the general formula (3) include compounds (A) to (G) having the following structural formula.
[0051]
[Chemical 3]

[0052]
Other polythiols include, for example, bis (2-mercaptoethyl) sulfide, di (2-mercaptoethyl) ether, 1,2-ethanedithiol, 1,4-butanedithiol, ethylene glycol dithioglycolate, trimethylolpropane tris. (Thioglycolate), pentaerythritol tetrakis (2-mercaptoacetate), dipentaerythritol hexakis (3-mercaptopropionate), dipentaerythritol hexakis (2-mercaptoacetate), 1,2-dimercaptobenzene, 4-methyl-1,2-dimercaptobenzene, 3,6-dichloro-1,2-dimercaptobenzene, 3,4,5,6-tetrachloro-1,2-dimercaptobenzene, O-xylylenedithiol , M-xylylene range Lumpur, p- xylylenedithiol and 1,3,5-tris (3-mercaptopropyl) isocyanurate and the like.
[0053]
Examples of the compound having one or more hydroxyl groups and thiol groups in one molecule include 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerol di (mercaptoacetate), 1-hydroxy-4- Mercaptocyclohexane, 2,4-dimercaptophenol, 2-mercaptohydroquinone, 4-mercaptophenol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3 -Butanediol, pentaerythritol tris (3-mercaptopropionate), pentaerythritol mono (3-mercaptopropionate), pentaerythritol bis (3-mercaptopropionate), pentaerythritol tris (thioglycolate) Pentaerythritol pentakis (3-mercaptopropionate), hydroxymethyl-tris (mercaptoethylthiomethyl) methane, 1-hydroxyethylthio-3-mercaptoethylthiobenzene, 4-hydroxy-4'-mercaptodiphenylsulfone, 2 Examples include-(2-mercaptoethylthio) ethanol, dihydroxyethyl sulfide mono (3-mercaptopropionate), dimercaptoethane mono (sulcylate), hydroxyethylthiomethyltris (mercaptoethylthio) methane, and the like.
[0054]
The mixing ratio of the polyisocyanate compound and active hydrogen is such that the ratio of isocyanate group (NCO) and active hydrogen (H) is NCO / H (molar ratio) = 0.5 to 3.0, particularly 0.5 to 1.5. A range is preferred.
[0055]
In addition, you may make it use the said polyisocyanate, a polyol, polythiol, and the compound which has 1 or more of hydroxyl groups and thiol groups in a molecule | numerator as a resin modifier with respect to said episulfide compounds.
[0056]
The curing catalyst is not particularly limited, but a tertiary amine, a tertiary phosphine, or a Lewis acid such as dimethyltin dichloride or dibutyltin dichloride is preferable. The amount of the curing catalyst used is generally in the range of 0.0005 to 5% by weight with respect to the polymerizable monomer.
[0057]
In the raw material composition of the present invention, a chain extender, a crosslinking agent, a light stabilizer, an ultraviolet absorber other than specific ultraviolet rays, an antioxidant, an anti-coloring agent, a dye, a filler, and an internal release agent are included as necessary. Various substances such as may be added. Specific examples of the antioxidant and the light stabilizer include a hindered amine light stabilizer, a hindered phenol antioxidant, a phosphite antioxidant, a thioether antioxidant, and the like.
[0058]
In the present invention, a benzotriazole ultraviolet absorber is used as the ultraviolet absorber. The benzotriazole-based ultraviolet absorber is characterized by excellent solubility in the polymerizable monomer constituting the raw material composition, high UV absorption ability, durability, and a wide absorption wavelength range. Among them, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole is particularly excellent in solubility with respect to polymerizable monomers, and does not become cloudy and imparts a high ultraviolet absorbing ability in a state of being yellow and small in color. Since it is easy to do, it is preferable. When other UV absorbers such as benzophenone other than benzotriazole are used, the UV absorption ability is insufficient, and after polymerization and curing, the appearance of the UV absorber becomes poor due to phenomena such as precipitation of the UV absorber and cloudiness. The problem of becoming.
[0059]
In the present invention, a specific ultraviolet absorber having a uniform particle size is used, and a specific ultraviolet absorber having a particle size of 500 μm or less, preferably 250 μm or less is used. When a specific ultraviolet absorber containing a coarse particle size is used, the solubility is remarkably lowered, the time for the preparation process is lengthened, and the productivity is lowered.
[0060]
In order to obtain the specific ultraviolet absorber having the above particle size, for example, there is a method in which a commercially available specific ultraviolet absorber is sieved, a portion having a large particle size is removed, and a small particle size is selected. Further, a commercially available specific ultraviolet absorber may be pulverized using a pulverizer such as a ball mill, and sieved as necessary.
[0061]
The blending amount of the specific ultraviolet absorber having such a particle size is 0.5 to 1.5 parts by weight with respect to 100 parts by weight of the monomer composition in which the polymerizable monomer is a main component and a curing catalyst and other components are added. It is a range. A plastic lens in which a specific ultraviolet absorber is blended in this range has an ultraviolet absorbing ability of absorbing almost 100% of ultraviolet rays having a wavelength of 400 nm or less and absorbing almost 100% of ultraviolet rays having a wavelength of 380 to 390 nm or less. That is, the transmittance at 400 nm is 20% or less, and the transmittance at 380 to 390 nm or less is almost 0%. When the blending amount is smaller than 0.5 parts by weight, the ultraviolet absorbing ability is not sufficiently exhibited. On the other hand, when the amount exceeds 1.5 parts by weight, the lens is markedly yellow and the appearance of the lens becomes poor due to cloudiness.
[0062]
The preparation step of the raw material composition is a step of preparing the raw material composition by mixing the polymerizable monomer, the curing catalyst, the specific ultraviolet absorber and other components in the above compounding amounts. The above-mentioned compounds such as episulfide are relatively unstable, and it is considered desirable in the preparation process to be in the temperature range of −10 ° C. to 30 ° C. The dissolution rate of the specific ultraviolet absorber in the compound such as episulfide at this low temperature is slow because it may be dissolved at a high concentration. In order to completely dissolve the conventional specific ultraviolet absorber without adjusting the particle size, a stirring time of about 3 hours was required. When a specific ultraviolet absorber having a small particle size was used, it was possible to completely dissolve it with a stirring time of about 30 minutes to 1 hour. By shortening the blending time, it became possible to increase the efficiency of the manufacturing equipment, and the productivity was remarkably improved. In addition, there is no risk of clogging of the filter due to the specific ultraviolet absorbent remaining undissolved when the raw material composition is filtered after the preparation.
[0063]
There is no restriction | limiting in the order of preparation in a preparation process. For example, a method of adding a curing catalyst last after dissolving an ultraviolet absorber or other components in a polymerizable monomer can be employed.
[0064]
After the blending process, a polymerization process for polymerizing and curing the raw material composition is performed. In the polymerization step, the raw material composition is poured into a molding mold made of two glass molds whose side surfaces are held by, for example, a gasket or tape, and the raw material composition is cured in an atmosphere in which the molding mold can be adjusted to a predetermined temperature. Then, a casting polymerization method is used to obtain a plastic lens in which the shape of the cavity of the molding mold is transferred.
[0065]
In the polymerization molding of plastic lenses, when producing a finish lens in which both surfaces of the lens are finished to the specified optical surface by transfer from the molding mold, one side is finished to the optical surface by transfer from the molding mold, and the opposite side In some cases, a semi-finished lens whose surface is cut into an optical surface by polishing is manufactured.
[0066]
As a polymerization temperature condition of the raw material composition, for example, as initial polymerization, the temperature is increased from 10 to 40 ° C. for 4 to 10 hours, from that temperature to the highest temperature of 100 to 140 ° C. in 3 to 7 hours, and the temperature is maintained for 1 to 3 hours. The heating pattern is generally cooled to room temperature over 3 to 5 hours and requires a total polymerization time of 15 to 25 hours.
[0067]
The polymerization temperature is adjusted by, for example, arranging a molding mold in the polymerization furnace and adjusting the temperature of the atmosphere in the polymerization furnace.
[0068]
When a compound such as episulfide is used as the main component of the polymerizable monomer, the raw material is kept at a temperature of 20 ± 15 ° C. for 5 hours or more, preferably within 50 hours, particularly preferably 8 to 24 hours in the initial polymerization stage. Gel the composition. By carrying out the gelation under the low initial polymerization temperature condition, the occurrence of optical distortion can be suppressed as much as possible, and the yield can be improved. When the initial polymerization temperature is lower than the above temperature, it takes a long time until gelation, which is disadvantageous in production. If the initial polymerization temperature is too high, optical distortion is likely to occur. If the initial polymerization time is too short, gelation is insufficient and optical distortion is likely to occur. On the other hand, even if the initial polymerization time is lengthened, the polymerization reaction hardly proceeds any further, which is not preferable from the viewpoint of production efficiency. Usually, the temperature is constant within the above temperature range, but the temperature may be changed within the above temperature range.
[0069]
When a compound such as episulfide is used as the polymerizable monomer, the maximum temperature during polymerization is set to 125 ° C to 140 ° C. If the maximum temperature is low, the lens power is not stabilized by one annealing after polymerization, and the lens power may continue to change due to subsequent heat treatment. On the other hand, when the maximum temperature at the time of polymerization exceeds 140 ° C., yellow becomes strong in the lens color tone after polymerization, and may not be used for a spectacle lens for which colorless and transparent are desired.
[0070]
The molded mold can be taken out from the polymerization furnace, and the plastic lens cured by disassembling the molded mold can be taken out.
[0071]
Reheating the plastic lens taken out from the molding mold and performing the annealing treatment is a preferable processing method in order to stabilize the lens power and remove optical distortion of the lens. The processing temperature at this time is 70 degreeC-160 degreeC, Preferably it is 80 degreeC-140 degreeC. The treatment time is 10 minutes to 6 hours, preferably 1 hour to 3 hours.
[0072]
In the case where the plastic lens formed by polymerization is a finish lens, the final plastic lens is obtained by performing processing steps such as dyeing, formation of a hard coat film, and formation of an antireflection film without being polished.
[0073]
If the plastic lens formed by polymerization is a semi-finished lens, a polishing process is performed in which one surface is cut into a predetermined optical surface. After the polishing step, a final plastic lens is obtained through processing steps such as dyeing, formation of a hard coat film, and formation of an antireflection film as necessary.
[0074]
The plastic lens thus obtained has 0.5 to 1.5 parts by weight of a benzotriazole-based UV absorber such as 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole as the UV absorber. Since it mix | blends, it is excellent in ultraviolet-ray absorption ability and can protect eyes from ultraviolet-ray.
[0075]
【Example】
Abbreviations of the compounds used in Examples and Comparative Examples are as follows.
Compounds such as episulfide
A-1: Bis- (2,3-epithiopropyl) disulfide
Thiol compound
B-1: 4,8or4,7or5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane
B-2: Bis (2-mercaptoethyl) sulfide
Polyisocyanate compound
C-1: m-xylylene diisocyanate
UV absorber
S-701: 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole (trade name: Seasorb 701 manufactured by Cypro Kasei Co., Ltd., commercially available product)
S-701P: A commercially available product of the above S-701 is sieved with a sieve having an opening of 250 μm and passed through a sieve having an opening of 250 μm.
S-706: 2- (2H-benzotriazol-2-yl-)-4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol (trade name Seasorb 706 manufactured by Cypro Kasei Co., Ltd. )
S-707: 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole (trade name Seasorb 707 manufactured by Cypro Kasei Co., Ltd.)
S-709: 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole (trade name: Seasorb 709 manufactured by Cypro Kasei Co., Ltd.)
T-234: 2- (2-hydroxy-3,5-bis (α, α'dimethylbenzyl) phenyl) -2H-benzotriazole (trade name: Tinuvin 234, manufactured by Ciba Specialty Chemicals Co., Ltd.)
[0076]
Example 1
As a lens raw material composition, the compounds shown in Table 1 were mixed at a composition ratio shown in Table 1 at a temperature of 20 ° C., and then the compounds shown in Table 1 as ultraviolet absorbers were added in the amounts shown in Table 1 and stirred for 1 hour. At the time, the appearance of the raw material composition was visually confirmed, and the solubility of the ultraviolet absorber was evaluated according to the following criteria.
[0077]
<Solubility>
○: Undissolved UV absorber particles are not observed.
(Triangle | delta): A small amount of ultraviolet absorber particles remain undissolved and are dispersed in the monomer.
X: Most of the ultraviolet absorber particles remain undissolved.
[0078]
When it remained undissolved, it was further thoroughly stirred to completely dissolve it. Thereafter, 0.02 g of N, N-dimethylcyclohexylamine and 0.10 g of N, N-dicyclohexylmethylamine were added as catalysts, and the mixture was sufficiently stirred at 20 ° C. to obtain a uniform liquid. Next, this composition was poured into a glass mold for plastic lenses having a center thickness of 1.2 mm, and the temperature was raised from 30 ° C. to 120 ° C. over 24 hours in an atmospheric polymerization furnace to be cured by polymerization. Thereafter, the lens was released from the glass mold, and was annealed by heating at 130 ° C. for 2 hours.
[0079]
The plastic lens thus manufactured was evaluated for quality by the following method. The results are shown in Table 2.
[0080]
<Refractive index>
The refractive index of D line (589.3 nm) was measured at 20 ° C. with an Abbe refractometer.
[0081]
<Abbe number>
The Abbe number of D line (589.3 nm) was measured at 20 ° C. with an Abbe refractometer.
[0082]
<Ultraviolet absorption ability>
Using a spectrophotometer U-3500 (manufactured by Hitachi), the transmission spectrum of the central portion of the lens (the portion where the lens thickness is the thinnest) was measured, and the transmittance at a wavelength of 400 nm was determined. Based on these results, classification was made as follows.
○: Ultraviolet rays are almost absorbed (wavelength 400 nm transmittance 20% or less).
(Triangle | delta): Absorption of an ultraviolet-ray is inadequate (wavelength 400nm transmittance | permeability 20-40%).
X: Ultraviolet rays are hardly absorbed (wavelength 400 nm transmittance 40% or more).
[0083]
<Light resistance>
Using a sunshine carbon arc lamp type weather resistance tester specified in JIS B 7753, the color tone (b *) of the lens is measured after an 80-hour acceleration test, and the change in b * is less than 2 compared to the initial value. ○ Two or more were marked with x.
[0084]
<Color tone>
The color tone of the lens obtained by visual observation was visually observed and classified as follows according to the level of yellowness.
○: Good
Δ: The lens is slightly yellowed. Or some precipitation of an ultraviolet absorber is seen.
X: The lens is extremely yellowed. Or the precipitation of a UV absorber is seen remarkably.
[0085]
<White turbidity>
By applying light from the edge of the lens, the white turbidity of the lens was visually observed, and classified according to the level of white turbidity as follows.
○: No cloudiness is observed.
Δ: Light cloudiness is observed.
X: Dark cloudiness is seen.
[0086]
(Example 2)
A lens was produced under the same conditions as in Example 1 except that the raw material composition was changed as shown in Table 1, and the same quality evaluation as in Example 1 was performed. The evaluation results are shown in Table 2.
[0087]
(Example 3)
After mixing the compound shown in Table 1 as a lens raw material composition at a composition ratio shown in Table 1 at a temperature of 20 ° C., the amount shown in Table 1 was added as an ultraviolet absorber, and when the mixture was stirred for 1 hour, the appearance of the raw material composition was improved. It confirmed visually and evaluated the solubility of the ultraviolet absorber on the same basis as Example 1.
[0088]
If it remained undissolved, it was further thoroughly stirred to dissolve it completely. Then, after adding and stirring 0.75g of internal mold release agents, 0.03g of dibutyltin dichloride was added as a catalyst, and the mixture was stirred and dissolved, and then deaerated under a vacuum of 5 mmHg for 60 minutes. Subsequently, this composition was poured into a glass mold for a plastic lens having a center thickness of 1.2 mm, and the temperature was raised from 30 ° C. to 120 ° C. over 17 hours in an atmospheric polymerization furnace to be cured by polymerization. Thereafter, the lens was released from the glass mold, and annealed by heating at 120 ° C. for 2 hours.
[0089]
The quality of the plastic lens thus produced was evaluated by the same method as in Example 1, and the results are shown in Table 2.
[0090]
(Comparative Examples 1-12)
A lens was produced under the same conditions as in Example 1 except that the raw material composition, the type and addition amount of the ultraviolet absorber were changed as shown in Table 1, and the same quality evaluation as in Example 1 was performed. The evaluation results are shown in Table 2.
[0091]
[Table 1]

[0092]
[Table 2]

[0093]
From the results shown in Table 2, when 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole was used that was not subjected to sieving and having a large particle size (Comparative Examples 1, 2, and 9), Solubility is poor. When the blending amount of the UV absorber is less than the range of the present invention (Comparative Examples 3 and 10), when the UV absorbing ability is inferior and the blending amount is too large (Comparative Examples 4 and 11), white turbidity occurs. When an ultraviolet absorber other than 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole is used (Comparative Examples 5 to 8 and 12), white turbidity occurs, and the UV absorption ability decreases and the lens is remarkably produced. Yellowing or marked precipitation of UV absorber.
[0094]
On the other hand, when 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole excluding those having a particle size larger than 250 μm as an ultraviolet absorber is used in a blending amount within the range of the present invention, It is recognized that the solubility is good, the composition dissolves in a stirring time of 1 hour, has excellent ultraviolet absorbing ability, and does not generate white turbidity or coloring.
[0095]
【The invention's effect】
According to the method for producing a plastic lens of the present invention, it is possible to improve the productivity by shortening the preparation time of the raw material composition.

Claims (9)

Removing the benzotriazole ultraviolet absorber having a particle size larger than 500 μm ;
The monomer 100 parts by weight of the composition containing a polymerizable monomer as a main component, dissolving the particle size 500μm following base benzotriazole-based UV absorber 0.5-1.5 parts by weight of the obtained in the step A preparation process of the raw material composition;
And a polymerization step of polymerizing and curing the raw material composition. In the manufacturing method of the plastic lens of Claim 1,
The method for producing a plastic lens, wherein the benzotriazole ultraviolet absorber is 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole. In the manufacturing method of the plastic lens of Claim 1 or 2,
The method for producing a plastic lens, wherein the polymerizable monomer contains a compound having at least one episulfide group in one molecule. In the manufacturing method of the plastic lens of Claim 1 or 2,
The method for producing a plastic lens, wherein the polymerizable monomer contains a compound having one or more disulfide bonds (SS) in one molecule and having an epoxy group and / or a thioepoxy group. In the manufacturing method of the plastic lens of Claim 1 or 2,
The method for producing a plastic lens, wherein the polymerizable monomer contains, as main components, a polyisocyanate having two or more isocyanate groups and a compound having two or more active hydrogens. In the manufacturing method of the plastic lens of Claim 5,
The method for producing a plastic lens, wherein the compound having two or more active hydrogens is polythiol. In the manufacturing method of the plastic lens of Claim 5 or 6,
A method for producing a plastic lens, wherein the polyisocyanate has an aromatic skeleton as a cyclic skeleton. In the manufacturing method of the plastic lens of Claim 7,
A method for producing a plastic lens, wherein the polyisocyanate having an aromatic skeleton as the cyclic skeleton is xylylene diisocyanate. In the manufacturing method of the plastic lens in any one of Claims 1-8,
The method for producing a plastic lens, wherein the temperature of the monomer composition in the preparation step is in the range of -10 ° C to 30 ° C.