JP3632940B2 - Methacrylic resin molded product and method for producing the same - Google Patents

Description

で表されるα−メチルスチレンダイマー、或いはそれらの２つのベンゼン核のうちの一方または両方がその連鎖移動効果に大きな影響を及ぼさない置換基（例えば炭素数１〜４のアルキル基、好ましくはメチル基、エチル基など）で置換されている置換α−メチルスチレンダイマーのうちの少なくとも１種に由来する構造単位である。
【００１６】
本発明のメタクリル系樹脂成形品は、１種類のメタクリル酸メチル系重合体からなっていても、または２種以上のメタクリル酸メチル系重合体のブレンド物であってもよく、したがってメタクリル系樹脂全体から見たときに、上記した構造単位（ａ）、構造単位（ｂ）および構造単位（ｃ）が何らかの形態で且つ次に説明する割合でメタクリル系樹脂中に結合した単位として存在していてメタクリル系樹脂成形品が形成されていればよい。
【００１７】
本発明のメタクリル系樹脂成形品では、成形品を形成するメタクリル系樹脂全体から見たときに、構造単位（ａ）：構造単位（ｂ）の重量比が８０：２０〜９９：１であることが必要であり、９０：１０〜９９：１であることが好ましく、９２：８〜９８．５：１．５であることがより好ましい。
構造単位（ａ）と構造単位（ｂ）の合計重量に基づいて、構造単位（ａ）の割合が８０重量％未満であると［構造単位（ｂ）の割合が２０重量％を超えると］、ガラス転移温度が低くなり過ぎて、熱的性質、機械的強度などの物性が低下する。一方、構造単位（ａ）と構造単位（ｂ）の合計重量に基づいて、構造単位（ａ）の割合が９９重量％を超えると［構造単位（ｂ）の割合が１重量％未満であると］、成形性が悪くなり、目的とするメタクリル系樹脂成形品が得られなくなる。
【００１８】
さらに、本発明のメタクリル系樹脂成形品では、成形品を形成するメタクリル系樹脂全体からみたときに、｛構造単位（ａ）と構造単位（ｂ）の合計重量｝：｛構造単位（ｃ）の重量｝の比が１００：０．２〜０．８である。構造単位（ａ）と構造単位（ｂ）の合計１００重量部に対して、α−メチルスチレンダイマーに由来する構造単位（ｃ）の割合が前記した０．２〜０．８重量部であることにより、メタクリル系樹脂成形品の製造時に、α−メチルスチレンダイマーによる重合度低下効果が発揮されて、熱成形加工性に優れるメタクリル系樹脂成形品が得られ、しかもα−メチルスチレンダイマーによる重合阻害が大きくなり過ぎず、メタクリル系樹脂成形品を製造するための重合反応が円滑に進行する。
【００１９】
また、本発明のメタクリル系樹脂成形品は、更に、（メタ）アクリル酸多価エステルに由来する構造単位（ｄ）を有する。構造単位（ｄ）を構成する（メタ）アクリル酸多価エステルは、ジオール、トリオール、テトラオールなどの多価アルコールのジー、トリー、テトラー（メタ）アクリル酸エステルなどの多価エステルである。（メタ）アクリル酸多価エステルの具体例としては、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ジ（メタ）アクリレート、トリエチレングリコールトリ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、プロピレングリコールジ（メタ）アクリレート、ジプロピレングリコールジ（メタ）アクリレート、トリプロピレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、トリメチロールエタンジ（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、１，３−ブチレングリコールジ（メタ）アクリレート、１，４−ブチレングリコールジ（メタ）アクリレート、１，６−ヘキサングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、２，２−ビス［４−（メタクリロキシエトキシ）フェニル］プロパン、２，２−ビス［メタクリロキシジエトキシ）フェニル］プロパンなどを挙げることができる。本発明のメタクリル系樹脂成形品は、前記した（メタ）アクリル酸多価エステルの１種または２種以上に由来する構造単位を有していることができる。
【００２０】
本発明のメタクリル系樹脂成形品では、（メタ）アクリル酸多価エステルに由来する構造単位（ｄ）となる（メタ）アクリル酸多価エステルが架橋剤として働き、メタクリル系樹脂成形品中に架橋結合が形成されるため、耐熱性の向上、成形品における偏肉防止などを図ることができる［以下（メタ）アクリル酸多価エステルを架橋剤ということがある］。
メタクリル系樹脂成形品における構造単位（ｄ）の含有量は、構造単位（ａ）と構造単位（ｂ）の合計重量に基づいて５重量％以下であり、２重量％以下であることがより好ましい。メタクリル系樹脂成形品における構造単位（ｄ）の含有量が５重量％を超えると、熱成形加工性（二次成形加工性）が低下して、深絞り成形ができなくなったり、曲げ加工などができにくくなり、熱成形加工時に割れなどが発生し易くなる。
【００２１】
本発明のメタクリル系樹脂成形品は、（ｉ）（ａ）メタクリル酸メチル、（ｂ）アルキル基の炭素数が２〜２０であるメタクリル酸アルキルエステルおよびアルキル基の炭素数が１〜２０であるアクリル酸アルキルエステルから選ばれる少なくとも１種の（メタ）アクリル酸アルキルエステル、（ｃ）ベンゼン核が置換されていてもよいα−メチルスチレンダイマー、（ｄ）（メタ）アクリル酸多価エステル並びに（ｅ）重合開始剤を含む未架橋の液状重合性混合物、或いはメタクリル酸メチルおよび／または前記（メタ）アクリル酸アルキルエステルからなる重合体を含む前記未架橋の液状重合性混合物であって、（ii）全メタクリル酸メチル成分：全前記（メタ）アクリル酸アルキルエステル成分の重量比が８０：２０〜９９：１であり、且つ（iii）｛全メタクリル酸メチルと全前記（メタ）アクリル酸アルキルエステル成分（ｂ）の合計重量｝：｛α−メチルスチレンダイマー成分の重量｝の比が１００：０．２〜０．８であり、そして（iv）（メタ）アクリル酸多価エステル成分を全メタクリル酸メチル成分と全前記（メタ）アクリル酸アルキルエステル（ｂ）成分の合計重量に基づいて５重量％以下の割合で含有する未架橋の液状重合性混合物を用いて、重合および成形を同時に行う方法によって製造される。その際に、（メタ）アクリル酸多価エステルによる架橋反応が重合および成形と同時に行われる。したがって、本発明でいう「重合」とは、「重合および架橋」を意味する。
なお、本明細書における「全メタクリル酸メチル成分」とは、液状重合性混合物に含まれる、メタクリル酸メチル（単量体）と、メタクリル酸メチルおよび／または前記（メタ）アクリル酸アルキルエステルからなる重合体中のメタクリル酸メチル成分（構造単位）の合計を意味し、「全前記（メタ）アクリル酸アルキルエステル成分」とは、液状重合性混合物に含まれる、前記（メタ）アクリル酸アルキルエステル（単量体）と、メタクリル酸メチルおよび／または前記（メタ）アクリル酸アルキルエステルからなる重合体中の前記（メタ）アクリル酸アルキルエステル成分（構造単位）の合計を意味する。
【００２２】
より具体的には、本発明では、下記の（Ａ）〜（Ｃ）のいずれかの方法が好ましく採用される。
（Ａ） メタクリル酸メチル、（メタ）アクリル酸アルキルエステル（ｂ）、α−メチルスチレンダイマー、（メタ）アクリル酸多価エステルおよび重合開始剤を含む未架橋の液状重合性混合物（単量体混合物）であって、メタクリル酸メチル：（メタ）アクリル酸アルキルエステル（ｂ）の重量比が８０：２０〜９９：１であり、｛メタクリル酸メチルと（メタ）アクリル酸アルキルエステル（ｂ）の合計重量｝：｛α−メチルスチレンダイマーの重量｝の比が１００：０．２〜０．８であり、そして（メタ）アクリル酸多価エステルをメタクリル酸メチルと（メタ）アクリル酸アルキルエステル（ｂ）の合計重量に基づいて５重量％以下の割合で含有する未架橋の液状重合性混合物（未架橋の液状単量体混合物）を用いて重合および成形を同時に行う方法。
【００２３】
（Ｂ） メタクリル酸メチルを、重合開始剤を用いて重合させてメタクリル酸メチル重合体を含むシロップをつくり、そのシロップに、（メタ）アクリル酸アルキルエステル（ｂ）、α−メチルスチレンダイマーおよび（メタ）アクリル酸多価エステル、さらに必要な場合はメタクリル酸メチルおよび重合開始剤をさらに添加して、シロップ中に含まれるメタクリル酸メチル系重合体を構成するメタクリル酸メチル成分の量をも含めて、全メタクリル酸メチル成分：（メタ）アクリル酸アルキルエステル（ｂ）の重量比が８０：２０〜９９：１であり、｛全メタクリル酸メチル成分と（メタ）アクリル酸アルキルエステル（ｂ）の合計重量｝：｛α−メチルスチレンダイマーの重量｝の比が１００：０．２〜０．８であり、そして（メタ）アクリル酸多価エステルを全メタクリル酸メチル成分と（メタ）アクリル酸アルキルエステル（ｂ）の合計重量に基づいて５重量％以下の割合で含有する未架橋の液状重合性混合物（メタクリル酸メチル重合体を含有する未架橋の液状重合性混合物）をつくり、その未架橋の液状重合性混合物を用いて重合および成形を同時に行う方法。
【００２４】
（Ｃ） メタクリル酸メチルおよび（メタ）アクリル酸アルキルエステル（ｂ）を、重合開始剤を用いて重合させてメタクリル酸メチル／（メタ）アクリル酸アルキルエステル（ｂ）共重合体および場合によりメタクリル酸メチル重合体や（メタ）アクリル酸アルキルエステル（ｂ）重合体を含むシロップをつくり、そのシロップに、α−メチルスチレンダイマーおよび（メタ）アクリル酸多価エステル、さらに必要な場合はメタクリル酸メチルおよび／または（メタ）アクリル酸アルキルエステル（ｂ）および重合開始剤を添加して、シロップ中に含まれるメタクリル酸メチル／（メタ）アクリル酸アルキルエステル（ｂ）共重合体、メタクリル酸メチル重合体、（メタ）アクリル酸アルキルエステル（ｂ）重合体を構成するメタクリル酸メチル成分の量および（メタ）アクリル酸アルキルエステル（ｂ）成分の量を含めて、全メタクリル酸メチル成分：全（メタ）アクリル酸アルキルエステル（ｂ）成分の重量比が８０：２０〜９９：１であり、｛全メタクリル酸メチル成分と全（メタ）アクリル酸アルキルエステル（ｂ）成分の合計重量｝：｛α−メチルスチレンダイマーの重量｝の比が１００：０．２〜０．８であり、そして（メタ）アクリル酸多価エステルを全メタクリル酸メチル成分と全（メタ）アクリル酸アルキルエステル（ｂ）成分の合計重量に基づいて５重量％以下の割合で含有する未架橋の液状重合性混合物（前記した重合体を含有する未架橋の液状重合性混合物）をつくり、その未架橋の液状重合性混合物を用いて重合と成形を同時に行う方法。
【００２５】
上記したメタクリル系樹脂成形品の製造方法でメタクリル酸メチルと共に用いる（メタ）アクリル酸アルキルエステル（ｂ）、α−メチルスチレンダイマーおよび（メタ）アクリル酸多価エステルとしては、本発明のメタクリル系樹脂成形品における構造単位（ｂ）、構造単位（ｃ）および構造単位（ｄ）を構成する化合物として上記で説明したのと同じ化合物の１種または２種以上が用いられる。
【００２６】
上記したメタクリル系樹脂成形品の製造方法で用いる重合開始剤としては、メタクリル系樹脂の製造に従来から用いられている重合開始剤のいずれもが使用でき、特にアゾ系重合開始剤、過酸化物系重合開始剤などのラジカル重合開始剤が好ましく用いられる。何ら限定されるものではないが、アゾ系重合開始剤の具体例としては、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス−１−シクロヘキサンカルボニトリル、２，２’−アゾビス−２，４−ジメチルバレロニトリル、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリルなどを挙げることができる。また、過酸化物系重合開始剤の具体例としては、ｔ−ブチルパーオキシイソブチレート、１，１’−ビス−ｔ−ブチルパーオキシ−３，３，５−トリメチルシクロヘキサン、ラウロイルパーオキサイドなどを挙げることができる。
重合開始剤の使用量は、重合性混合物の重量に基づいて、０．０００１〜２重量％であることが好ましく、０．００１〜１重量％であることがより好ましい。
メタクリル系樹脂成形品を製造するための重合・同時成形方法は特に制限されないが、注型法が好ましく採用される。
【００２７】
重合・同時成形温度は、採用する重合・同時成形方法の種類、重合・同時成形に用いる液状重合性混合物の組成などに応じて異なり得るが、一般には４０〜１４０℃の温度が好ましく採用される。例えば、注型法による場合は温度４０〜９０℃で前段の重合を行い、それに続いて温度１００〜１４０℃で後段の重合を行って、重合と成形を同時に行うことによって、目的とするメタクリル系樹脂成形品を円滑に得ることができる。
【００２８】
また、本発明のメタクリル系樹脂成形品は、必要に応じて種々の添加剤、例えば染顔料、酸化防止剤や紫外線吸収剤などの安定剤、可塑剤、離型剤などを含有していてもよい。本発明のメタクリル系樹脂成形品中に添加剤を含有させる場合は、重合・同時成形が行われる以前のいずれかの段階で、添加剤を加えるようにすればよい。
【００２９】
本発明のメタクリル系樹脂成形品の形状、構造、寸法などは特に制限されず、使用目的や用途などに応じて決めることができる。特に、本発明のメタクリル系樹脂成形品は、熱成形加工性に優れていて、加熱下に容易に且つ円滑に曲げ加工、深絞り成形などの二次成形加工を行って、目的とする成形加工品を寸法精度良く製造することができるので、曲げ加工や深絞り成形に用い易い板状成形品の形態にしておくと便利である。
【００３０】
本発明のメタクリル系樹脂成形品は、耐熱水性、耐湿熱性および透明性に優れていて、熱水や加熱水蒸気に長期間さらされても、ヘイズ、白化、クラックの発生、膨れなどが生じにくいので、浴槽、浴室の壁材や床材、洗面化粧台などのようなサニタリー用製品、システムキッチンの天板などの厨房製品、さらには住宅などの扉、出窓やその他の内外装材などとして、種々の用途に有効に使用することができる。
【００３１】
【実施例】
以下に本発明を実施例などにより具体的に説明するが、本発明はそれにより何ら限定されない。なお、以下の例において、特に断らない限りは、部は重量部を意味する。また、以下の例で示した諸特性は次のようにして測定または評価した。
【００３２】
（ｉ）耐熱水性（耐煮沸性）：
金属製の容器に水を入れ、その中に以下の実施例または比較例で得られたメタクリル系樹脂成形品（厚さ５ｍｍの板状成形品）から切り出した寸法が５０ｍｍ×５０ｍｍの試験片を浸漬し、容器ごとオーブンに入れて水の温度が９５℃になるまで加熱し、温度を９５℃に保ったまま試験片を熱湯中に３００時間浸漬し、３００時間後に熱水より取り出して、そのヘイズ値を全光線透過率計（村上色彩研究所製：ＨＲ−１００）を用いて測定して、耐熱水性（耐煮沸性）を調べた。
【００３３】
（ii）熱成形加工性：
（ ii ）−１： 以下の実施例または比較例で得られたメタクリル系樹脂成形品（厚さ５ｍｍの板状成形品）から、寸法が５００ｍｍ×７００ｍｍの試験片を切り出し、赤外線ヒーターで試験片を１９０℃および２００℃のそれぞれの温度に加熱して、それぞれの温度で真空成形を−７４０ｍｍＨｇの減圧下（２０ｍｍＨｇの圧力下）に行って、図１に示す形状および曲げ加工部寸法（曲率半径）を有する成形体（浴槽モデル用成形体）を製造した。なお、図１の（ａ）は前記の真空成形で得られた成形体の縦断面図を示したものであり、図１の（ｂ）は前記の真空成形で得られた成形体を上から見た平面図である。
また、真空成形型内面における、図１の（ｂ）の１Ｒ〜５Ｒで示した５カ所の曲げ加工部に相当する部分の寸法（曲率半径）は、１Ｒ＝３０ｍｍ、２Ｒ＝３０ｍｍ、３Ｒ＝４０ｍｍ、４Ｒ＝３０ｍｍおよび５Ｒ＝４０ｍｍである。
（ ii ）−２： 上記の（ ii ）−１の真空成形で得られた成形体における、図１の（ｂ）の１Ｒ〜５Ｒで示した５カ所の曲げ加工部の寸法（曲率半径）を測定して、その値が、真空成形型の内面の該１Ｒ〜５Ｒに相当する部分の寸法（曲率半径）と一致しているか否かを判定すると共に、クラックの発生などの欠陥部分の有無を調べて、熱成形加工性の評価を行った。
成形体の各曲げ加工部の寸法（曲率半径）が、真空成形型の内面の各曲げ部寸法（曲率半径）と同じ場合は、熱成形加工性が良好であると判定され、一方真空成形型の内面の各曲げ部寸法（曲率半径）よりも大きい場合は、真空成形時に試験片が真空成形型の内面に密着しなかったことに起因するものであるから、熱成形加工性が不良であると判定される。
【００３４】
《実施例１》
（１） メタクリル酸メチル５０ｋｇに２，２’−アゾビスイソブチロニトリル（重合開始剤）１ｇを添加し、撹拌しながら９５℃に３５分間加熱した後室温に冷却して、メタクリル酸メチル重合体を含有するシロップを得た（重合率は１０％）。
（２） 上記（１）で得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル３９０ｇ、１，３−ブチレングリコールジメタクリレート［（メタ）アクリル酸多価エステル；架橋剤］５２ｇおよびα−メチルスチレンダイマー（連鎖移動剤）５２ｇを添加して均一に混合し、これにさらにステアリン酸（離型剤）１３ｇ、紫外線吸収剤（CIBA GEIGY社製：Ｔinuvin Ｐ）２．６ｇ、および２，２’−アゾビス−２，４−ジメチルバレロニトリル（重合開始剤）２．５ｇ添加混合して、液状の重合性混合物を調製した。
（３） 上記（２）で得られた重合性混合物を脱泡処理した後、常法にしたがって、ガスケットを２枚の平行な強化ガラスに挟んで作った鋳型間に注入し、７０℃の水槽に４時間浸漬し、次いで１２０℃の空気槽で２時間加熱を行って、重合を完了させて厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（４） 上記（３）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行った。その結果は、下記の表１に示すとおりである。
また、上記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００３５】
《実施例２》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル６５０ｇ、エチレングリコールジメタクリレート（架橋剤）５２ｇおよびα−メチルスチレンダイマー（連鎖移動剤）５２ｇを添加して均一に混合し、これにさらに実施例１の（２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
また、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００３６】
《実施例３》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル６５０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）２６ｇおよびα−メチルスチレンダイマー（連鎖移動剤）３９ｇを添加して均一に混合し、これにさらに実施例１の（２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
また、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００３７】
《実施例４》
（１） メタクリル酸メチル１３ｋｇ、アクリル酸ブチル３９０ｇ、エチレングリコールジメタクリレート（架橋剤）５２ｇおよびα−メチルスチレンダイマー（連鎖移動剤）９１ｇを添加して均一に混合し、これにさらに実施例１の（２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
また、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００３８】
《実施例５》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、メタクリル酸ラウリル９１０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびα−メチルスチレンダイマー（連鎖移動剤）６５ｇを添加して均一に混合し、これにさらに実施例１の（２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
また、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００３９】
《参考例１》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル３９０ｇおよびα−メチルスチレンダイマー（連鎖移動剤）５２ｇを添加して均一に混合し、これにさらに実施例１の（２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
また、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生が全くなかった。
【００４０】
《比較例１》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル６５０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびラウリルメルカプタン(連鎖移動剤)１９.５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
なお、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生はなかった。
【００４１】
《比較例２》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびラウリルメルカプタン(連鎖移動剤)１９.５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
なお、前記成形体の製造時に、薄くなった箇所やクラックの発生などの欠陥部分の発生はなかった。
【００４２】
《比較例３》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびラウリルメルカプタン(連鎖移動剤)６．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
【００４３】
《比較例４》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル６５０ｇおよびエチレングリコールジメタクリレート（架橋剤）５２ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
なお、この比較例４の場合は、２００℃での真空成形時に試験片が破れてしまって、成形ができなかった。
【００４４】
《比較例５》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸２−エチルヘキシル６５０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびラウリルメルカプタン（連鎖移動剤）６．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
【００４５】
《比較例６》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸ブチル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよび２−メルカプトエタノール（連鎖移動剤）１９．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
【００４６】
《比較例７》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸ブチル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびオクチルメルカプタン（連鎖移動剤）１９．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
【００４７】
《比較例８》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸ブチル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよび四臭化炭素（連鎖移動剤）６５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
【００４８】
《比較例９》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸ブチル６５０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびテルピノレン（連鎖移動剤）６．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）を製造した。
（３） 上記（２）で得られたメタクリル系樹脂成形品（板状成形品）から作製した試験片を用いて、上記（ｉ）に記載した方法でヘイズ値を測定して耐熱水性（耐煮沸性）を調べると共に、上記（ii）に記載した方法で成形体をつくり、その熱成形加工性の評価を行ったところ、下記の表１に示すとおりであった。
なお、この比較例４の場合は、２００℃での真空成形時に試験片が破れてしまって、成形ができなかった。
【００４９】
《比較例１０》
（１） 実施例１の（１）と同じ操作を行って得られたシロップ１０ｋｇに、メタクリル酸メチル３ｋｇ、アクリル酸ブチル３９０ｇ、１，３−ブチレングリコールジメタクリレート（架橋剤）５２ｇおよびテルピノレン（連鎖移動剤）６．５ｇを添加して均一に混合し、これにさらに実施例１の(２）と同様にして離型剤、紫外線吸収剤および重合開始剤添加混合して液状の重合性混合物を調製した。
（２） 上記（１）で得られた重合性混合物を用いて、実施例１の（３）と全く同様にして、厚さ５ｍｍのメタクリル系樹脂成形品（板状成形品）の製造を試みたところ、重合阻害が大きくて、前段での重合率が低く且つ後段での重合時に発砲が生じて、外観の不良なメタクリル系樹脂成形品（板状成形品）となった。
そのため、この比較例１０では、耐熱水性および熱成形加工性の試験を中止した。
【００５０】
【表１】

【００５１】
上記の表１の結果から、メタクリル酸メチル、（メタ）アクリル酸アルキルエステル（ｂ）および（メタ）アクリル酸多価エステルと共に、α−メチルスチレンダイマー（連鎖移動剤）をメタクリル酸メチルと（メタ）アクリル酸アルキルエステル（ｂ）の合計重量に基づいて０．２〜０．８重量％の範囲の量で用いて得られた実施例１〜５のメタクリル系樹脂成形品、すなわち構造単位（ａ）、構造単位（ｂ）、構造単位（ｃ）および構造単位（ｄ）を本発明で規定する範囲の量で有する本発明のメタクリル系樹脂成形品は、９５℃の熱湯中に３００時間浸漬した後でも、そのヘイズ値が極めて小さく、耐熱水性に優れていること、しかも熱成形加工性に優れていて、真空成形によって深絞り成形を行った場合に、その曲がり部の寸法（曲率半径）が真空成形型における寸法と完全に一致し、目的とする形状および寸法を有する成形体を寸法精度良く製造できることがわかる。
【００５２】
それに対して、メルカプタン系化合物または四臭化炭素からなる連鎖移動剤を０．０５〜２重量％の範囲で用いて得られた比較例１〜２および比較例６〜８のメタクリル系樹脂成形品は、９５℃の熱湯中に３００時間浸漬した後にヘイズ値が大幅に上昇し、白化しており、耐熱水性に劣っていることがわかる。
また、メルカプタン系化合物またはテルピノレンからなる連鎖移動剤を本発明で規定している量よりも少ない量で用いている比較例３、比較例５および比較例９、並びに連鎖移動剤を使用しない比較例４で得られたメタクリル系樹脂成形品は熱成形加工性に劣っており、真空成形型の形状および寸法どおりの成形体が得られないことがわかる。
さらに、連鎖移動剤としてテルピノレンを用いた比較例１０の場合は、重合反応が円滑に行われず、メタクリル系樹脂成形品が得られなかったことがわかる。
【００５３】
《実施例７》
（１） 実施例１の（３）で得られたメタクリル系樹脂成形品（板状成形品）を用いて、上記（ii）（熱成形加工性の評価）におけるのと全く同じ方法で、図１に示す成形体（浴槽モデル用成形体）を製造し、その外側（裏側）全体に、ガラス繊維マット（日東紡株式会社製「＃４５０」）を６枚重ねてかぶせ、そこに不飽和ポリエステル樹脂（大日本インキ株式会社製「ポリライトＬＰ９２４」）１００部にメチルエチルケトンパーオキサイド含有液（濃度５５重量％；日本油脂株式会社製「パーメックＮ」）１．５部を加えたものを７００ｇ／ｍ２の割合で均一に塗布し、それを温度２０℃でゲルさせた後（ゲル化時間約１５分）、硬化させ（硬化時間約４時間）、さらに６０℃に昇温してから６０分加熱して、成形体の外側を補強した積層成形体（浴槽）を製造した。
（２） 上記（１）で得られた積層成形体（浴槽）の内側に水をその上端部から５ｃｍの位置まで満たし、水温が９３℃になるように加熱し、その温度に５００時間保った後、熱水を抜いて、クラックの発生を目視により観察したが、白化が全く生じていなかった。
【００５４】
《比較例１１》
（１） 比較例１の（２）で得られたメタクリル系樹脂成形品（板状成形品）を用いて、上記（ii）（熱成形加工性の評価）におけるのと全く同じ方法で、図１に示す成形体（浴槽モデル用成形体）を製造し、その外側（裏側）全体に、実施例１と同様にして、ガラス繊維マットで強化された不飽和ポリエステル樹脂の硬化層を形成して外側を補強した積層成形体（浴槽）を製造した。
（２） 上記（１）で得られた積層成形体（浴槽）の内側に水をその上端部から５ｃｍの位置まで満たし、水温が９３℃になるように加熱し、その温度に５００時間保った後、熱水を抜いて、クラックの発生を目視により観察したところ、湯に接触していた面が白化しており、商品価値が著しく低下した。
【００５５】
【発明の効果】
本発明のメタクリル系樹脂成形品は、熱成形加工性に優れており、加熱下で絞り成形や曲げ加工などを行なって湾曲部などを有する成形体を製造した場合に、目的とする成形体を、割れなどを生ずることなく、高い寸法精度で良好に製造することができる。
さらに、本発明のメタクリル系樹脂成形品は、耐熱水性および耐湿熱性に優れており、熱水や加熱水蒸気に長期間曝されても、ヘイズ、白化、クラック、ふくれなどのトラブルが発生しない。
そして、本発明の製造方法による場合は、上記した優れた特性を有するメタクリル系樹脂成形品を円滑に製造することができる。
本発明のメタクリル系樹脂成形品は、上記した優れた特性を活かして、浴室、浴槽、洗面所、トイレなどのサニタリー分野をはじめとして、システムキッチンの天板などの厨房製品、家屋の内外装材、その他の種々の用途に有効に使用することができる。
【図面の簡単な説明】
【図１】本発明の実施例および比較例において、熱成形加工性および耐熱水性の評価を行うために作製した成形体の形状および構造を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention is a methacrylic resinMOLDED ARTICLE, ITS MANUFACTURING METHOD, AND SANITARY PRODUCT FORMED FROM THE METHACRYLIC RESIN MOLDED ARTICLEAbout. More specifically, the present invention is excellent in thermoforming processability, such as deep drawing or bending under heating.Secondary forming ofIs a methacrylic resin that can be smoothly applied with high dimensional accuracy, has excellent hot water resistance and moist heat resistance, and does not generate haze, whitening, cracks, or blisters even when exposed to hot or heated steam for a long period of time.MOLDED ARTICLE, ITS MANUFACTURING METHOD, AND SANITARY PRODUCT FORMED FROM THE METHACRYLIC RESIN MOLDED ARTICLEThe thermoplastic resin of the present inventionMoldingUtilizing the above-mentioned excellent characteristics, can be effectively used in various applications such as kitchen products, interior / exterior materials of houses, etc., including sanitary fields such as bathrooms, bathtubs, toilets, and toilets.
[0002]
[Prior art]
Methacrylic resins are excellent in transparency, colorability, moldability, weather resistance, etc., and are widely used in various fields as signs, decoration materials, lighting covers, automobile parts, glazing materials, etc. by taking advantage of these properties. ing. Furthermore, in recent years, as the use of methacrylic resins has expanded, it has been used in so-called sanitary fields such as bathtubs, bathrooms, and washrooms, and kitchen fields such as the tops of system kitchens. Conventionally, unsaturated polyester has been widely used as a plastic bathtub, but since it has poor hydrolysis resistance, there is a problem that the surface deteriorates when used for a long time. On the other hand, a methacrylic resin bath is excellent in hydrolysis resistance and does not have a problem such as deterioration due to hot water as in an unsaturated polyester resin, but its thermoforming processability is not sufficient.
[0003]
Molded products used in sanitary fields such as bathtubs and washstands, and kitchens, unlike signboards that are often composed of flat surfaces, have many curved parts, and therefore are not suitable for methacrylic resins used for such applications. On the other hand, there is a demand for high thermoformability that enables drawing and bending to be performed with high dimensional accuracy, and therefore development of methacrylic resin materials with improved moldability has been attempted. .
[0004]
As such a prior art, a polymer sheet is produced by adding a chain transfer agent and a crosslinking agent comprising a mercaptan, a polyhaloalkane or a phosphine to a methyl methacrylate syrup containing a methyl methacrylate polymer, and performing polymerization. (Japanese Unexamined Patent Publication No. 54-142270), a monomer mixture mainly composed of methyl methacrylate, alkyl mercaptan, aromatic mercaptan, thioglycolic acid, thioglycolic acid ester, β-mercaptopropionic acid or β-mercaptopropion A method for producing an acrylic resin sheet by adding a chain transfer agent comprising an acid ester and a polymerization initiator to form a syrup by polymerization and adding a polymerization initiator and a crosslinking agent to the syrup and polymerizing in a mold No. 6-70098) is known.
However, although the methacrylic resin materials obtained by those conventional techniques show some improvement in terms of thermoforming processability, they are not sufficient in hot water resistance and moist heat resistance, and when exposed to hot water or high temperature steam. , Haze, whitening, cracks, etc. occur, so it cannot be used for sanitary fields such as bathtubs, bathrooms, vanities, and system kitchen tops.
[0005]
Further, a monomer such as methyl methacrylate, styrene, α-methylstyrene 70% by weight or more and less than 95% by weight, a crosslinking agent such as ethylene glycol dimethacrylate 5% by weight or more 30% by weight, and α-methylstyrene dimer 0.1 A transparent plastic obtained by polymerizing a monomer mixture of 2% by weight is known (Japanese Patent Laid-Open No. 58-201812). However, in this prior art, the crosslinking agent is used in an extremely large amount of 5 to 30% by weight, and therefore the plastic obtained there is a thermosetting resin that is not deformed or fused by heat. When a product having a curved portion or the like is obtained, machining such as cutting or polishing is used. For this reason, this plastic cannot be drawn or bent under heating.
[0006]
[Problems to be solved by the invention]
The object of the present invention is excellent in thermoforming processability, and when drawn or bent under heating, a product having a curved portion can be produced with high dimensional accuracy, and also has hot water resistance and moisture and heat resistance. A methacrylic resin that does not cause troubles such as haze, whitening, cracks, and blisters even when exposed to hot water or steam for a long period of timeMoldingIs to provide.
The object of the present invention is to provide a methacrylic resin having the above-described excellent characteristics.MoldingIt is to provide a manufacturing method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the inventors have made various studies. As a result, with respect to the methyl methacrylate component, (meth) acrylic acid alkyl ester components other than methyl methacrylate are blended in a specific amount, and α-methylstyrene dimer is specifically selected as a chain transfer agent to that specific amount. BlendedUncrosslinked liquidWith polymerizable mixtureSuch as plateMethacrylic resinMoldingMethacrylic resin obtained by manufacturingMoldingHowever, it has excellent thermoforming processability, such as drawing and bending under heat.Secondary molding processTo produce a molded body having a curved portion with high dimensional accuracy, and is excellent in hot water resistance and moist heat resistance, even if exposed to hot water or steam for a long period of time, such as haze, whitening, cracks, blisters, etc. I found no trouble.
[0008]
Furthermore, the present inventors have made such a methacrylic resin.MoldingWhen a (meth) acrylic acid polyvalent ester is used in a specific amount or less during the production of the methacrylic resin, the heat resistance is improved and the uneven thickness prevention effect is obtained in combination with the above-described characteristics.MoldingAnd the present invention was completed based on these findings.
[0009]
That is, the present invention includes i) (a) methyl methacrylate, (b) alkyl methacrylate having 2 to 20 carbon atoms and alkyl acrylate having 1 to 20 carbon atoms. At least one (meth) acrylic acid alkyl ester selected, (c) an α-methylstyrene dimer in which the benzene nucleus may be substituted, (d) a (meth) acrylic acid polyvalent ester, and (e) a polymerization initiator Or an uncrosslinked liquid polymerizable mixture containing methyl methacrylate and / or a polymer comprising the (meth) acrylic acid alkyl ester, (ii)allMethyl methacrylate component:allThe weight ratio of the (meth) acrylic acid alkyl ester component is 80:20 to 99: 1, and (iii) {allWith methyl methacrylate componentallThe ratio of the total weight of the (meth) acrylic acid alkyl ester component}: {weight of the α-methylstyrene dimer component} is 100: 0.2 to 0.8, and (iv) the (meth) acrylic acid Valent ester componentallWith methyl methacrylate componentallUsing a non-crosslinked liquid polymerizable mixture contained in a proportion of 5% by weight or less based on the total weight of the (meth) acrylic acid alkyl ester component, a molded product is produced by simultaneously performing polymerization and molding. It is a manufacturing method of the methacrylic-type resin molded product made into.
The present invention includes, as a preferred embodiment, a method for producing a molded product by injecting the above-mentioned uncrosslinked liquid polymerizable mixture into a mold and performing polymerization and molding simultaneously.
[0010]
And this invention is a methacrylic-type resin molded product obtained by the said manufacturing method,
(I) At least selected from the structural unit (a) derived from methyl methacrylate, the alkyl methacrylate having 2 to 20 carbon atoms in the alkyl group, and the alkyl acrylate having 1 to 20 carbon atoms in the alkyl group Structural unit (b) derived from one kind of (meth) acrylic acid alkyl ester, structural unit (c) derived from α-methylstyrene dimer in which the benzene nucleus may be substituted, and (meth) acrylic acid polyvalent ester Having a structural unit (d) derived from
( ii ) The weight ratio of structural unit (a): structural unit (b) is 80:20 to 99: 1;
( iii ) {Total weight of structural unit (a) and structural unit (b)}: {weight of structural unit (c)} is 100: 0.2 to 0.8; and
( iv ) Having the structural unit (d) in a proportion of not more than 5% by weight with respect to the total weight of the structural unit (a) and the structural unit (b);
It is a methacrylic resin molded product characterized by being formed from a methacrylic resin..
[0011]
The present inventionIncludes the above methacrylic resin molded products for sanitary products and sanitary products formed from the methacrylic resin molded products.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
Methacrylic resin of the present inventionMoldingAs described above, the structural unit (a) derived from methyl methacrylate, the alkyl group having 2 to 20 carbon atoms in the alkyl group and the alkyl ester having 1 to 20 carbon atoms in the alkyl group. Structural unit (b) α- derived from at least one (meth) acrylic acid alkyl ester selected from the above (that is, (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group excluding methyl methacrylate) A structural unit (c) derived from methylstyrene dimer, andStructural unit (d) derived from (meth) acrylic acid polyvalent esterConsists of at least methacrylic resinThe molded product is obtained by simultaneously performing polymerization and molding using a specific uncrosslinked liquid polymerizable mixture mainly composed of a (meth) acrylic monomer according to the above-described production method..
[0013]
As described above, the structural unit (b) is a structural unit composed of an alkyl ester of (meth) acrylic acid other than methyl methacrylate, and the alkyl group in the alkyl ester has a carbon number of 1 to 20 (meth) acrylic. It is composed of an acid alkyl ester [hereinafter referred to as “(meth) acrylic acid alkyl ester (b)”], and is composed of (meth) acrylic acid alkyl ester (b) whose alkyl group has 1 to 12 carbon atoms. Preferably it is. Examples of (meth) acrylic acid alkyl ester (b) include methyl acrylate, ethyl acrylate, propyl acrylate, isobutyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, propyl methacrylate, methacryl Examples thereof include propyl acid, isobutyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate.Methacrylic resin that forms molded productsMay have a structural unit derived from one or more of the aforementioned (meth) acrylic acid alkyl ester (b). Among them, the structural unit (b) is a structural unit derived from at least one of 2-ethylhexyl acrylate, butyl acrylate, and lauryl methacrylate, such as thermoforming processability, hot water resistance, and heat and moisture resistance. It is more preferable from the point.
[0014]
Methacrylic resin of the present inventionMoldingThe α-methylstyrene dimer constituting the structural unit (c) in the formula is represented by the following chemical formulas (I) and (II):
[0015]
[Chemical 1]

Or a substituent in which one or both of the two benzene nuclei do not significantly affect the chain transfer effect (for example, an alkyl group having 1 to 4 carbon atoms, preferably methyl A structural unit derived from at least one of the substituted α-methylstyrene dimers substituted with a group, an ethyl group or the like.
[0016]
Methacrylic resin of the present inventionMoldingMay be composed of one type of methyl methacrylate polymer or a blend of two or more types of methyl methacrylate polymer, and as described above when viewed from the whole methacrylic resin. The structural unit (a), the structural unit (b), and the structural unit (c) are present as a unit bonded in the methacrylic resin in some form and in a proportion described below.MoldingShould just be formed.
[0017]
Methacrylic resin of the present inventionMoldingThenForm a molded productWhen viewed from the whole methacrylic resin, the weight ratio of structural unit (a): structural unit (b) must be 80:20 to 99: 1, and 90:10 to 99: 1. It is more preferable that it is 92: 8-98.5: 1.5.
When the proportion of the structural unit (a) is less than 80% by weight based on the total weight of the structural unit (a) and the structural unit (b) [when the proportion of the structural unit (b) exceeds 20% by weight], The glass transition temperature becomes too low, and physical properties such as thermal properties and mechanical strength deteriorate. On the other hand, based on the total weight of the structural unit (a) and the structural unit (b), when the proportion of the structural unit (a) exceeds 99% by weight, [the proportion of the structural unit (b) is less than 1% by weight. ], The moldability deteriorates and the target methacrylic resinMoldingCannot be obtained.
[0018]
Furthermore, the methacrylic resin of the present inventionMoldingThenForm a molded productWhen viewed from the whole methacrylic resin, the ratio of {total weight of structural unit (a) and structural unit (b)}: {weight of structural unit (c)} is 100:0.2-0.8. The proportion of structural unit (c) derived from α-methylstyrene dimer is 100 parts by weight in total of structural unit (a) and structural unit (b).By being 0.2 to 0.8 parts by weight as described above, Methacrylic resinMoldingOf the degree of polymerization by α-methylstyrene dimerBeenMethacrylic resin with excellent thermoforming processabilityA molded product is obtained, and polymerization inhibition by α-methylstyrene dimer does not become too large, and the polymerization reaction for producing a methacrylic resin molded product proceeds smoothly..
[0019]
The methacrylic resin of the present inventionMoldingIsMore, A structural unit (d) derived from (meth) acrylic acid polyvalent esterHave. The (meth) acrylic acid polyvalent ester constituting the structural unit (d) is a polyhydric ester such as diol, triol, tetraol, or other polyhydric alcohol such as diol, trie, or tetra (meth) acrylate. Specific examples of the (meth) acrylic acid polyvalent ester include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol tri (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di ( (Meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolethane di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 3-butylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethylo Propane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [methacryloxydiethoxy) phenyl] propane, etc. Can do. Methacrylic resin of the present inventionMoldingMay have a structural unit derived from one or more of the aforementioned (meth) acrylic acid polyvalent esters.
[0020]
In the methacrylic resin molded product of the present invention, the (meth) acrylic acid polyvalent ester that becomes the structural unit (d) derived from the (meth) acrylic acid polyvalent ester functions as a crosslinking agent, and is crosslinked in the methacrylic resin molded product. Bonds are formed to improve heat resistance and prevent uneven thickness in molded products.Plan[(Meth) acrylic acid polyester may be referred to as a cross-linking agent].
The content of the structural unit (d) in the methacrylic resin molded product is 5% by weight or less based on the total weight of the structural unit (a) and the structural unit (b), and 2% by weight or less.IsIt is more preferable. If the content of the structural unit (d) in the methacrylic resin molded product exceeds 5% by weight, the thermoforming processability (secondary forming processability) is lowered, and deep drawing cannot be performed, bending work, etc. It becomes difficult to generate cracks during thermoforming.
[0021]
The methacrylic resin molded product of the present invention has (i) (a) methyl methacrylate, (b) an alkyl group having 2 to 20 carbon atoms, and an alkyl group having 1 to 20 carbon atoms. At least one (meth) acrylic acid alkyl ester selected from alkyl acrylate esters, (c) an α-methylstyrene dimer in which the benzene nucleus may be substituted, (d) (meth) acrylic acid polyvalent ester and ( e) an uncrosslinked liquid polymerizable mixture containing a polymerization initiator, or the uncrosslinked liquid polymerizable mixture containing a polymer comprising methyl methacrylate and / or the (meth) acrylic acid alkyl ester, (ii) )allMethyl methacrylate component:allThe weight ratio of the (meth) acrylic acid alkyl ester component is 80:20 to 99: 1, and (iii) {allWith methyl methacrylateall(Meth) acrylic acid alkyl ester component (b) total weight}: {weight of α-methylstyrene dimer component} is 100: 0.2 to 0.8, and (iv) (meth) acrylic Acid polyester componentallWith methyl methacrylate componentallIt is produced by a method in which polymerization and molding are simultaneously carried out using an uncrosslinked liquid polymerizable mixture contained in a proportion of 5% by weight or less based on the total weight of the (meth) acrylic acid alkyl ester (b) component. At that time, a crosslinking reaction with a (meth) acrylic acid polyvalent ester is performed simultaneously with polymerization and molding. Therefore, “polymerization” in the present invention means “polymerization and crosslinking”.
The “total methyl methacrylate component” in the present specification is composed of methyl methacrylate (monomer) and methyl methacrylate and / or the (meth) acrylic acid alkyl ester contained in the liquid polymerizable mixture. It means the total of methyl methacrylate components (structural units) in the polymer, and “all the (meth) acrylic acid alkyl ester components” means the (meth) acrylic acid alkyl ester (included in the liquid polymerizable mixture). Monomer) and the total of the (meth) acrylic acid alkyl ester component (structural unit) in the polymer composed of methyl methacrylate and / or the (meth) acrylic acid alkyl ester.
[0022]
More specifically, in the present invention, any of the following methods (A) to (C) is preferably employed.
(A) Methyl methacrylate, (meth) acrylic acid alkyl ester (b), α-methylstyrene dimer, ((Meth) acrylic acid polyvalent esterAnd polymerization initiatorincludingUncrosslinked liquidA polymerizable mixture (monomer mixture), wherein the weight ratio of methyl methacrylate: (meth) acrylic acid alkyl ester (b) is 80:20 to 99: 1, {methyl methacrylate and (meth) acrylic The total weight of acid alkyl ester (b)}: {weight of α-methylstyrene dimer} is 100:0.2-0.8And then(Based on the total weight of the meth) acrylic acid polyester with methyl methacrylate and the alkyl (meth) acrylate (b)5% by weight or lessContained in a proportion ofUncrosslinked liquidPolymerizable mixture (Uncrosslinked liquidMonomer mixture)Simultaneous polymerization and molding usingMethod.
[0023]
(B) Methyl methacrylate,A syrup containing a methyl methacrylate polymer is prepared by polymerization using a polymerization initiator, and (meth) acrylic acid alkyl ester (b), α-methylstyrene dimer is added to the syrup.and((Meth) acrylic acid polyesters, and if necessary, methyl methacrylateAnd polymerization initiatorThe weight ratio of all methyl methacrylate components: (meth) acrylic acid alkyl ester (b), including the amount of methyl methacrylate components constituting the methyl methacrylate polymer contained in the syrup Is 80:20 to 99: 1, and the ratio of {total weight of all methyl methacrylate components and (meth) acrylic acid alkyl ester (b)}: {weight of α-methylstyrene dimer} is 100:0.2-0.8And then((Meth) acrylic acid polyester based on the total weight of all methyl methacrylate components and (meth) acrylic acid alkyl ester (b)5% by weight or lessContained in a proportion ofUncrosslinked liquidPolymerizable mixture (contains methyl methacrylate polymerUncrosslinked liquidA polymerizable mixture)Uncrosslinked liquidPolymerizable mixtureSimultaneous polymerization and molding usingMethod.
[0024]
(C) Methyl methacrylate and (meth) acrylic acid alkyl ester (b),Syrup containing a methyl methacrylate / (meth) acrylic acid alkyl ester (b) copolymer and optionally a methyl methacrylate polymer or a (meth) acrylic acid alkyl ester (b) polymer by polymerization using a polymerization initiator And the syrup contains α-methylstyrene dimer and((Meth) acrylic acid polyvalent ester, and if necessary, methyl methacrylate and / or (meth) acrylic acid alkyl ester (b)And polymerization initiatorTo form a methyl methacrylate / (meth) acrylic acid alkyl ester (b) copolymer, a methyl methacrylate polymer, and a (meth) acrylic acid alkyl ester (b) polymer contained in the syrup. The weight ratio of total methyl methacrylate component: all (meth) acrylic acid alkyl ester (b) component, including the amount of acid methyl component and the amount of (meth) acrylic acid alkyl ester (b) component, is 80: 20-99. 1 and the ratio of {total weight of all methyl methacrylate components and all (meth) acrylic acid alkyl ester (b) components}: {weight of α-methylstyrene dimer} is 100:0.2-0.8And then(The (meth) acrylic acid polyester is based on the total weight of all methyl methacrylate components and all (meth) acrylic acid alkyl ester (b) components.5% by weight or lessContained in a proportion ofUncrosslinked liquidPolymerizable mixture (contains the aforementioned polymer)Uncrosslinked liquidA polymerizable mixture)Uncrosslinked liquidThe polymerizable mixtureTo perform polymerization and molding at the same timeMethod.
[0025]
Methacrylic resin as described aboveMolding(Meth) acrylic acid alkyl ester (b), α-methylstyrene dimer and (meth) acrylic acid polyvalent ester used together with methyl methacrylate in the production method of methacrylic resin of the present inventionMoldingAs the compound constituting the structural unit (b), the structural unit (c) and the structural unit (d), one or more of the same compounds described above are used.
[0026]
Methacrylic resin as described aboveMoldingAs the polymerization initiator used in this production method, any of the polymerization initiators conventionally used in the production of methacrylic resins can be used, particularly radicals such as azo polymerization initiators and peroxide polymerization initiators. A polymerization initiator is preferably used. Although not limited at all, specific examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 1,1′-azobis-1-cyclohexanecarbonitrile, 2,2′-. Examples thereof include azobis-2,4-dimethylvaleronitrile and 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile. Specific examples of the peroxide polymerization initiator include t-butyl peroxyisobutyrate, 1,1′-bis-t-butylperoxy-3,3,5-trimethylcyclohexane, lauroyl peroxide, and the like. Can be mentioned.
The amount of the polymerization initiator used is preferably 0.0001 to 2% by weight, more preferably 0.001 to 1% by weight, based on the weight of the polymerizable mixture.
Methacrylic resinMoldingPolymerization to produce・ Simultaneous moldingThe method is not particularly limited, but a casting method is preferably employed.
[0027]
polymerization·simultaneousThe molding temperature isHeavyTogethersimultaneousMolding method type, polymerization・ Simultaneous moldingUsed forLiquidGenerally, a temperature of 40 to 140 ° C. is preferably used, although it may vary depending on the composition of the polymerizable mixture. For example, in the case of the casting method, the former polymerization is carried out at a temperature of 40 to 90 ° C., followed by the latter polymerization at a temperature of 100 to 140 ° C. resinMoldingCan be obtained smoothly.
[0028]
The methacrylic resin of the present inventionMoldingMay contain various additives, for example, dyes and pigments, stabilizers such as antioxidants and ultraviolet absorbers, plasticizers, release agents and the like. Methacrylic resin of the present inventionMoldingWhen adding an additive inHeavyTogethersimultaneousThe additive may be added at any stage prior to molding.
[0029]
The shape, structure, dimensions and the like of the methacrylic resin molded product of the present invention are not particularly limited, and can be determined according to the purpose of use and application. In particular, the methacrylic resin of the present inventionMoldingIs excellent in thermoforming processability, and can easily and smoothly bend and deep-molding such as deep drawing under heating to produce the desired molded product with high dimensional accuracy. Therefore, it is convenient to use a plate-shaped molded product that can be easily used for bending and deep drawing.
[0030]
Methacrylic resin of the present inventionMoldingIs excellent in hot water resistance, moist heat resistance and transparency, and even when exposed to hot water or heated steam for a long period of time, it does not easily cause haze, whitening, cracking, or blistering. Sanitary products such as flooring materials and vanities, kitchen products such as tops of system kitchens, and doors, bay windows, and other interior and exterior materials for homes, etc. should be used effectively in various applications. Can do.
[0031]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, parts means parts by weight. Various characteristics shown in the following examples were measured or evaluated as follows.
[0032]
(I) Hot water resistance (boiling resistance):
A methacrylic resin obtained in the following Examples or Comparative Examples in which water is put in a metal containerMoldingA test piece having a size of 50 mm × 50 mm cut out from a (plate-shaped molded product having a thickness of 5 mm) was immersed, and the whole container was placed in an oven and heated until the temperature of water reached 95 ° C., and the temperature was maintained at 95 ° C. The test piece is immersed in hot water for 300 hours, taken out from the hot water after 300 hours, and its haze value is measured using a total light transmittance meter (manufactured by Murakami Color Research Laboratory: HR-100). (Boil resistance) was investigated.
[0033]
(Ii) Thermoforming processability:
( ii -1  Methacrylic resins obtained in the following examples or comparative examplesMoldingA test piece having a size of 500 mm × 700 mm is cut out from a (plate-shaped molded product having a thickness of 5 mm), and the test piece is heated to a temperature of 190 ° C. and 200 ° C. with an infrared heater, and vacuum molding is performed at each temperature. The molded body (molded body for bathtub model) having the shape and the dimension of the bent portion (curvature radius) shown in FIG. 1 was manufactured under a reduced pressure of −740 mmHg (under a pressure of 20 mmHg). 1A shows a longitudinal cross-sectional view of a molded body obtained by the vacuum forming, and FIG. 1B shows the molded body obtained by the vacuum forming from above. FIG.
Further, the dimensions (curvature radius) of the portions corresponding to the five bent portions indicated by 1R to 5R in FIG. 1B on the inner surface of the vacuum forming die are 1R = 30 mm, 2R = 30 mm, 3R = 40 mm. 4R = 30 mm and 5R = 40 mm.
( ii ) -2: above( ii -1The dimensions (curvature radii) of the five bent portions indicated by 1R to 5R in FIG. 1B in the molded body obtained by vacuum forming were measured, and the values were determined as the inner surface of the vacuum mold. It was determined whether or not the dimensions (curvature radius) corresponding to the portions corresponding to 1R to 5R were equal, and the presence or absence of a defective portion such as the occurrence of a crack was examined to evaluate thermoformability.
If the dimensions (curvature radius) of each bending part of the molded body are the same as the respective bending part dimensions (curvature radius) of the inner surface of the vacuum forming die, it is determined that the thermoforming workability is good, while the vacuum forming die If it is larger than the respective bend dimensions (curvature radius) of the inner surface of the steel sheet, it is caused by the fact that the test piece did not adhere to the inner surface of the vacuum forming mold during vacuum forming, and therefore the thermoforming processability is poor. It is determined.
[0034]
Example 1
(1) Add 1 g of 2,2′-azobisisobutyronitrile (polymerization initiator) to 50 kg of methyl methacrylate, heat to 95 ° C. for 35 minutes with stirring, cool to room temperature, A syrup containing coalescence was obtained (polymerization rate 10%).
(2) To 10 kg of the syrup obtained in (1) above, 3 kg of methyl methacrylate, 390 g of 2-ethylhexyl acrylate, 1,3-butylene glycol dimethacrylate [(meth) acrylic acid polyvalent ester; 52 g of α-methylstyrene dimer (chain transfer agent) was added and mixed uniformly. Further, 13 g of stearic acid (release agent), 2.6 g of ultraviolet absorber (CIBA GEIGY: Tinuvin P), and 2 , 2'-azobis-2,4-dimethylvaleronitrile (polymerization initiator) 2.5 g was added and mixed to prepare a liquid polymerizable mixture.
(3) After defoaming the polymerizable mixture obtained in (2) above, according to a conventional method, the gasket is poured between molds made by sandwiching two parallel tempered glasses, and a water bath at 70 ° C. For 4 hours, and then heated in an air bath at 120 ° C. for 2 hours to complete the polymerization to a methacrylic resin having a thickness of 5 mm.Molding(Plate-shaped molded product) was manufactured.
(4) Methacrylic resin obtained in (3) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. Molded bodies were produced and their thermoforming processability was evaluated. The results are as shown in Table 1 below.
In addition, there was no occurrence of defective parts such as thinned portions or cracks during the production of the molded body.
[0035]
Example 2
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 650 g of 2-ethylhexyl acrylate, 52 g of ethylene glycol dimethacrylate (crosslinking agent) and α-methylstyrene dimer (Chain transfer agent) 52 g was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to obtain a liquid polymerizable mixture. Prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation of defective parts such as thinned portions or cracks during the production of the molded body.
[0036]
Example 3
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 650 g of 2-ethylhexyl acrylate, 26 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and α -39 g of methylstyrene dimer (chain transfer agent) was added and mixed uniformly, and then a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed in the same manner as in (2) of Example 1 to obtain a liquid. A polymerizable mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation of defective parts such as thinned portions or cracks during the production of the molded body.
[0037]
Example 4
(1) 13 kg of methyl methacrylate, 390 g of butyl acrylate, 52 g of ethylene glycol dimethacrylate (crosslinking agent) and 91 g of α-methylstyrene dimer (chain transfer agent) were added and mixed uniformly. In the same manner as in (2), a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to prepare a liquid polymerizable mixture.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation of defective parts such as thinned portions or cracks during the production of the molded body.
[0038]
Example 5
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 910 g of lauryl methacrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and α-methyl 65 g of styrene dimer (chain transfer agent) was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to obtain a liquid polymerizable property. A mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation of defective parts such as thinned portions or cracks during the production of the molded body.
[0039]
《Reference example 1>>
(1) 3 kg of methyl methacrylate, 390 g of 2-ethylhexyl acrylate, and 52 g of α-methylstyrene dimer (chain transfer agent) were added to 10 kg of syrup obtained by performing the same operation as (1) of Example 1. The mixture was uniformly mixed, and a release agent, an ultraviolet absorber and a polymerization initiator were further added and mixed in the same manner as in (2) of Example 1 to prepare a liquid polymerizable mixture.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation of defective parts such as thinned portions or cracks during the production of the molded body.
[0040]
<< Comparative Example 1 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 650 g of 2-ethylhexyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and lauryl 19.5 g of mercaptan (chain transfer agent) was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to form a liquid polymerization. A sex mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation | occurrence | production of defect parts, such as the location which became thin at the time of manufacture of the said molded object, and generation | occurrence | production of a crack.
[0041]
<< Comparative Example 2 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 390 g of 2-ethylhexyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and lauryl 19.5 g of mercaptan (chain transfer agent) was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to form a liquid polymerization. A sex mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In addition, there was no generation | occurrence | production of defect parts, such as the location which became thin at the time of manufacture of the said molded object, and generation | occurrence | production of a crack.
[0042]
<< Comparative Example 3 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 390 g of 2-ethylhexyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and lauryl Mercaptan (chain transfer agent) 6.5 g was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to form a liquid polymerization. A sex mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
[0043]
<< Comparative Example 4 >>
(1) 3 kg of methyl methacrylate, 650 g of 2-ethylhexyl acrylate and 52 g of ethylene glycol dimethacrylate (crosslinking agent) are uniformly added to 10 kg of syrup obtained by performing the same operation as (1) of Example 1. This was mixed and further added with a release agent, an ultraviolet absorber and a polymerization initiator in the same manner as in (2) of Example 1 to prepare a liquid polymerizable mixture.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In the case of Comparative Example 4, the test piece was broken at the time of vacuum forming at 200 ° C. and could not be formed.
[0044]
<< Comparative Example 5 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 650 g of 2-ethylhexyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and lauryl Mercaptan (chain transfer agent) 6.5 g was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to form a liquid polymerization. A sex mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
[0045]
<< Comparative Example 6 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 390 g of butyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and 2-mercapto 19.5 g of ethanol (chain transfer agent) was added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to obtain a liquid polymerization. A sex mixture was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
[0046]
<< Comparative Example 7 >>
(1) To 10 kg of syrup obtained by performing the same operation as in (1) of Example 1, 3 kg of methyl methacrylate, 390 g of butyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and octyl mercaptan ( (Chain transfer agent) 19.5 g was added and mixed uniformly. Further, in the same manner as (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to form a liquid polymerizable mixture. Was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
[0047]
<< Comparative Example 8 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 390 g of butyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and tetrabromide 65 g of carbon (chain transfer agent) is added and mixed uniformly. Further, in the same manner as in (2) of Example 1, a release agent, an ultraviolet absorber and a polymerization initiator are added and mixed to form a liquid polymerizable mixture. Was prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
[0048]
<< Comparative Example 9 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 650 g of butyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and terpinolene (chain) (Transfer agent) 6.5 g was added and mixed uniformly. Further, in the same manner as in Example 1 (2), a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to obtain a liquid polymerizable mixture. Prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.Molding(Plate-shaped molded product) was manufactured.
(3) Methacrylic resin obtained in (2) aboveMoldingUsing the test piece prepared from (plate-shaped molded article), the haze value was measured by the method described in (i) above to examine hot water resistance (boiling resistance), and the method described in (ii) above. When a molded body was produced and its thermoforming processability was evaluated, it was as shown in Table 1 below.
In the case of Comparative Example 4, the test piece was broken at the time of vacuum forming at 200 ° C. and could not be formed.
[0049]
<< Comparative Example 10 >>
(1) To 10 kg of syrup obtained by performing the same operation as (1) of Example 1, 3 kg of methyl methacrylate, 390 g of butyl acrylate, 52 g of 1,3-butylene glycol dimethacrylate (crosslinking agent) and terpinolene (chain) (Transfer agent) 6.5 g was added and mixed uniformly. Further, in the same manner as in Example 1 (2), a release agent, an ultraviolet absorber and a polymerization initiator were added and mixed to obtain a liquid polymerizable mixture. Prepared.
(2) A methacrylic resin having a thickness of 5 mm in exactly the same manner as (3) of Example 1 using the polymerizable mixture obtained in (1) above.MoldingAttempts to produce (plate-shaped molded products) show that the polymerization inhibition is large, the polymerization rate in the former stage is low, and firing occurs during the polymerization in the latter stage, resulting in poor appearance of the methacrylic resin.Molding(Plate-shaped molded product).
Therefore, in Comparative Example 10, the test for hot water resistance and thermoforming processability was stopped.
[0050]
[Table 1]

[0051]
From the results in Table 1 above, methyl methacrylate, (meth) acrylic acid alkyl ester (b) and(Along with the (meth) acrylic acid polyester, α-methylstyrene dimer (chain transfer agent) based on the total weight of methyl methacrylate and (meth) acrylic acid alkyl ester (b)0.2-0.8Examples 1 to 3 obtained using amounts in the range of% by weight5Methacrylic resinMoldingThat is, structural unit (a), structural unit (b), structural unit (c) andConstructionMethacrylic resin of the present invention having a building unit (d) in an amount within the range specified in the present inventionMoldingEven after being immersed in hot water at 95 ° C for 300 hours, its haze value is extremely small, it has excellent hot water resistance, and it has excellent thermoforming processability, and when deep drawing is performed by vacuum forming In addition, it can be seen that the dimension (curvature radius) of the bent portion is completely coincident with the dimension in the vacuum forming die, and a molded article having a target shape and dimension can be manufactured with high dimensional accuracy.
[0052]
In contrast, chain transfer agents consisting of mercaptan compounds or carbon tetrabromideTheMethacrylic resins of Comparative Examples 1-2 and Comparative Examples 6-8 obtained by using in the range of 0.05-2% by weightMoldingShows that after immersing in hot water at 95 ° C. for 300 hours, the haze value is significantly increased and whitened, indicating poor hot water resistance.
Further, Comparative Example 3, Comparative Example 5 and Comparative Example 9 in which a chain transfer agent comprising a mercaptan compound or terpinolene is used in an amount smaller than the amount specified in the present invention, and a comparative example in which no chain transfer agent is used. Methacrylic resin obtained in 4MoldingIs inferior in thermoforming workability, and it can be seen that a molded body having the shape and dimensions of the vacuum mold cannot be obtained.
Furthermore, in the case of Comparative Example 10 using terpinolene as the chain transfer agent, the polymerization reaction is not smoothly performed, and the methacrylic resinMoldingIt can be seen that was not obtained.
[0053]
Example 7
(1) Methacrylic resin obtained in (1) of Example 1MoldingUsing the (plate-shaped molded product), the molded body (molded body for bathtub model) shown in FIG. 1 is manufactured in exactly the same manner as in (ii) (Evaluation of thermoforming processability), and the outside ( 6 glass fiber mats (“# 450” manufactured by Nittobo Co., Ltd.) are overlaid on the entire back side, and 100 parts of unsaturated polyester resin (“Polylite LP924” manufactured by Dainippon Ink Co., Ltd.) are added to methyl ethyl ketone peroxide After adding 1.5 parts of a liquid (concentration 55% by weight; “Permec N” manufactured by Nippon Oil & Fats Co., Ltd.) at a rate of 700 g / m 2 and gelling it at a temperature of 20 ° C. (gel For about 15 minutes) and cured (curing time about 4 hours), and further heated to 60 ° C. and then heated for 60 minutes to produce a laminated molded body (tub) in which the outside of the molded body was reinforced.
(2) Water was filled to the position of 5 cm from the upper end of the laminated molded body (tub) obtained in (1) above, heated so that the water temperature became 93 ° C., and kept at that temperature for 500 hours. Thereafter, hot water was drained, and the occurrence of cracks was visually observed, but no whitening occurred.
[0054]
<< Comparative Example 11 >>
(1) Methacrylic resin obtained in (2) of Comparative Example 1Molding(Plate-shaped molded product) is used to manufacture the molded body (molded body for bathtub model) shown in FIG. 1 in exactly the same manner as in (ii) (Evaluation of thermoforming processability), and the outside ( On the whole back side), a laminated molded body (bathtub) in which a cured layer of unsaturated polyester resin reinforced with a glass fiber mat was reinforced by reinforcing the outside in the same manner as in Example 1 was produced.
(2) Water was filled to the position of 5 cm from the upper end of the laminated molded body (tub) obtained in (1) above, heated so that the water temperature became 93 ° C., and kept at that temperature for 500 hours. Then, when hot water was removed and the occurrence of cracks was visually observed, the surface that had been in contact with the hot water was whitened, and the commercial value was significantly reduced.
[0055]
【The invention's effect】
Methacrylic resin of the present inventionMoldingIs excellent in thermoforming processability, and when a molded body having a curved portion or the like is produced by performing drawing or bending under heating, the target molded body does not crack, It can be manufactured satisfactorily with high dimensional accuracy.
Furthermore, the methacrylic resin of the present inventionMoldingIs excellent in hot water resistance and moist heat resistance, and does not cause troubles such as haze, whitening, cracks and blisters even when exposed to hot water or heated steam for a long period of time.
And when it is based on the manufacturing method of this invention, the methacrylic resin which has the above-mentioned outstanding characteristicMoldingCan be manufactured smoothly.
Methacrylic resin of the present inventionMoldingUtilizing the above-mentioned superior properties, it is effective for various products such as kitchen products such as bathrooms, bathtubs, toilets and toilets, kitchen products such as tops of system kitchens, interior and exterior materials for houses, etc. Can be used for
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing the shape and structure of a molded product produced for evaluating thermoforming processability and hot water resistance in Examples and Comparative Examples of the present invention.

Claims (5)

(I) at least one selected from (a) methyl methacrylate, (b) alkyl methacrylate having 2 to 20 carbon atoms in the alkyl group, and alkyl acrylate having 1 to 20 carbon atoms in the alkyl group (Meth) acrylic acid alkyl ester, (c) an α-methylstyrene dimer in which the benzene nucleus may be substituted, (d) (meth) acrylic acid polyester and (e) an uncrosslinked polymer containing a polymerization initiator the liquid polymerizable mixture, or the a liquid polymerizable mixture of uncrosslinked containing methyl methacrylate and / or the (meth) polymer consisting of acrylic acid alkyl esters, (ii) total methyl acrylate component: All the ( The weight ratio of the meth) acrylic acid alkyl ester component is 80:20 to 99: 1, and (iii) { total methyl methacrylate component and total The ratio of the total weight of the (meth) acrylic acid alkyl ester component}: {weight of the α-methylstyrene dimer component} is 100: 0.2 to 0.8, and (iv) the (meth) acrylic acid valence ester component all the the total methyl methacrylate component (meth) using a liquid polymerizable mixture of uncrosslinked a proportion of 5 wt% or less based on the total weight of the acrylic acid alkyl ester component, polymerization and molding A method for producing a methacrylic resin molded product, characterized in that the product is produced simultaneously. The method according to claim 1 , wherein the uncrosslinked liquid polymerizable mixture is injected into a mold, and polymerization and molding are simultaneously performed to produce a molded product. A methacrylic resin molded product obtained by the production method of claim 1 or 2,
(I) At least selected from the structural unit (a) derived from methyl methacrylate, the alkyl methacrylate having 2 to 20 carbon atoms in the alkyl group, and the alkyl acrylate having 1 to 20 carbon atoms in the alkyl group Structural unit (b) derived from one kind of (meth) acrylic acid alkyl ester, structural unit (c) derived from α-methylstyrene dimer in which the benzene nucleus may be substituted, and (meth) acrylic acid polyvalent ester Having a structural unit (d) derived from
(Ii) the weight ratio of structural unit (a): structural unit (b) is from 80:20 to 99: 1;
(Iii) {total weight of the structural units (a) and structural units (b)}: the ratio of {the weight of the structural unit (c)} is 100: 0.2 to 0.8 der Ri; and,
(Iv) having the structural unit (d) in a proportion of 5% by weight or less based on the total weight of the structural unit (a) and the structural unit (b);
A methacrylic resin molded product characterized by being formed from a methacrylic resin . The methacrylic resin molded product according to claim 3, which is used for sanitary products . A sanitary product formed from the methacrylic resin molded product according to claim 3 .

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