JP3700499B2 - refrigerator - Google Patents

Description

【００４１】
この表では、アルミ製モールドパネルおよび断熱箱体による断熱材の物性（フォーム膨れ量、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率、試験前後の歪み量の差、試験後の最大歪み量）を示す。この表１から、脱型５分後の膨れ量はパック率１１５％で２．３ｍｍ、パック率１２５％で２．７ｍｍと従来の断熱材に比べて低減できることがわかった。
【００４２】
次に、上記材料を用いて実機の箱体で評価を行ったのでその結果を以下に説明する。その際、図面を参照しながら以下説明する。
【００４３】
図１は、冷蔵庫および冷凍庫の箱体１に冷蔵室扉６、野菜室扉７、上段冷凍室扉８、下段冷凍室扉９を設置した縦断面図である。まず、外箱鉄板と内箱樹脂壁の箱体をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温２０℃、治具温４５℃にして、硬質ポリウレタンフォームを空隙部分に発泡充填する。その時、ウレタンフォームのポリオールとイソシアネートが化学反応を起こし、発泡圧力による加圧で発泡ウレタンフォームが箱体の壁内空間に注入充填され、断熱箱体を作製した。その際、の注入容積は約２００リットルを有する箱体でウレタン材料のゼロパック（実機充填に必要な最低注入量）を設定後、オーバーパックの１１０％パック率で注入した。
【００４４】
また、図２は断熱箱体にウレタンを４点発泡充填する模式図とウレタン測定サンプル採取の模式図を示す。冷蔵庫および冷凍庫の断熱箱体の底面中央部分から断熱材フォームサンプルを採取して種々の物性を評価した。まず、コア層密度は２００ｍｍ×２００ｍｍ×２０ｍｍtのサンプル寸法と重量を測定後、重量を体積で除した値および熱伝導率も英弘精機社製HC−０７３型（熱流計法、平均温度１０℃）を用いて評価した。
【００４５】
圧縮強度は５０ｍｍ×５０ｍｍ×２０ｍｍtのフォームサンプルを送り速度４ｍｍ／ｍｉｎで変形させて、１０％変形時の応力を元の受圧面積で除した値で評価した。低温寸法変化率および高温寸法変化率は１５０ｍｍ×３００ｍｍ×２０ｍｍtのフォームを−２０℃で２４時間もしくは７０℃で２４時間放置した時の厚さの変化率を評価した。
【００４６】
これらの結果を表１に併せて示す。表１から、コア層密度が２９．２ｋｇ／ｍ3と低密度で熱伝導率が１７．６ｍＷ／ｍ・Ｋと低くなり、圧縮強度が０．１５ＭＰａと高く、低温寸法変化率が−１．１％、高温寸法変化率が１．６％と変化が小さいことが判る。
【００４７】
さらに、外箱表鉄板の歪み量は、長さ３００ｍｍの表面が平滑な角棒の中央部にダイヤルゲージを取付けた歪み測定器具を用いて行った。測定法は外箱表鉄板面に測定器具を当てた時の歪みの最大値をもって表す。箱体側面の歪み量は、まず試験前の歪み量を測定しその分布を明示した後で、−１０℃の恒温室内に４８時間放置する。その後、恒温室内から取出し直ちに試験前と同様に歪み量を測定して、試験前後の歪み量の差および試験後の最大歪み量を評価した。
【００４８】
これらの結果も表１に示す。表１から、試験前後の歪み量差が０．１ｍｍで最大歪み量が０．３ｍｍと小さい値を示すことが判る。
【００４９】
さらに、硬質ポリウレタンフォームの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレー）を組み込んで測定した結果、熱漏洩量が４％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【００５０】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【００５１】
〔比較例１〕
表１に示すポリオールＡ６０部とポリオールＣ２０部およびポリオールＤ２０部とシクロペンタン発泡剤を１２部、水１．７部および反応触媒としてテトラメチルヘキサメチレンジアミン１．８部とペンタメチルジエチレントリアミン０．３部、トリス（３ージメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．５部、整泡剤として有機シリコーンのＢ−８４６２を１．８部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体を１４０部用いて発泡させた。その時のポリオールとイソシアネートの液温は２０℃に調整した。
【００５２】
まず、ポリオールとイソシアネートを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００５３】
季語言うその結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で４．９ｍｍ、パック率１２５％で５．６ｍｍと大きくなることが判る。
【００５４】
次に、実施例１と同様に冷蔵庫および冷凍庫の外箱鉄板と内箱をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２０℃、治具温度を４０℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して冷蔵庫および冷凍庫の断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価し、さらに断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００５５】
これらの結果を表１に併せて示す。表１から、コア層密度が３４．５ｋｇ／ｍ3で熱伝導率が１８．５ｍＷ／ｍ・Ｋと高く、さらに圧縮強度も０．１１ＭＰａ、低温寸法変化率が−２．１％、高温寸法変化率が１．８％と変化が大きいことが判る。
【００５６】
さらに、冷蔵庫および冷凍庫の断熱箱体の低温放置を行った結果、外扉表鉄板の歪み試験前後の歪み量差は０．２２ｍｍで試験後の最大歪み量も０．６６ｍｍと大きくなり、断熱箱体の外扉鉄板に歪み変形が発生した。
【００５７】
〔実施例２〕
表１に示すポリオールＡ４０部とポリオールＢ３０部およびポリオールＥ２８部とポリオールＦ２部とシクロペンタン発泡剤を１７部、水１．３部および反応触媒としてテトラメチルヘキサメチレンジアミン１．５部とペンタメチルジエチレントリアミン０．２部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．６部、整泡剤として有機シリコーンのＢ−８４６１を２．２部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体とプレポリマ−変性トリレンジイソシアネートを１３５部を用いて発泡させた。その時のポリオールとイソシアネートの液温は２５℃に調整した。
【００５８】
まず、ポリオールとイソシアネートを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００５９】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．４ｍｍ、パック率１２５％で２．９ｍｍと従来の断熱材に比べて低減できることが判る。
【００６０】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２５℃、治具温度を４０℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１５％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００６１】
これらの結果を表１に併せて示す。表１から、コア層密度が３１．８ｋｇ／ｍ3と低密度で熱伝導率が１７．８ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１４ＭＰａ、低温寸法変化率が−１．３％、高温寸法変化率が１．５％と小さくなることが判る。
【００６２】
さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０９ｍｍで試験後の最大歪み量も０．２９ｍｍと小さい値を示した。さらに、硬質ポリウレタンフォームの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレー）を組み込んで測定した結果、熱漏洩量が３％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【００６３】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【００６４】
〔比較例２〕
表１に示すポリオールＢ６０部とポリオールＣ１０部およびポリオールＤ２０部とポリオールＥ１０部にシクロペンタン発泡剤を１１部、水１．４部および反応触媒としてテトラメチルヘキサメチレンジアミン１．２部とペンタメチルジエチレントリアミン０．５部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．６部、整泡剤として有機シリコーンのＢ−８４６２を１．８部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体およびプレポリマー変性トリレンジイソシアネートの混合物を１３７部用いて発泡させた。その時のポリオールとイソシアネートの液温は２５℃に調整した。
【００６５】
まず、ポリオールとイソシアネートを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００６６】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で４．１ｍｍ、パック率１２５％で５．２ｍｍと大きくなることが判る。
【００６７】
次に、実施例１と同様に冷蔵庫および冷凍庫の外箱鉄板と内箱をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２５℃、治具温度を４０℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１５％で発泡充填して冷蔵庫および冷凍庫の断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価し、さらに断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００６８】
これらの結果を表１に併せて示す。表１から、コア層密度が３５．２ｋｇ／ｍ3で熱伝導率が１８．８ｍＷ／ｍ・Ｋと高く、さらに圧縮強度も０．０９ＭＰａと低く、低温寸法変化率が−２．３％、高温寸法変化率が２．２％と変化が大きい値を示すことが判る。
【００６９】
さらに、冷蔵庫および冷凍庫の断熱箱体の低温放置試験を行った結果、外扉表鉄板の歪み試験前後の歪み量差は０．１６ｍｍで試験後の最大歪み量も０．５６ｍｍと大きくなり、断熱箱体の外扉鉄板に歪み変形が発生した。
【００７０】
〔実施例３〕
表１に示すポリオールＡ３０部とポリオールＢ２０部およびポリオールＣ２０部とポリオールＤ１０部とポリオールＥ２０部にシクロペンタン発泡剤を１８部、水１．２部および反応触媒としてテトラメチルヘキサメチレンジアミン１．７部とペンタメチルジエチレントリアミン０．３部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．５部、整泡剤として有機シリコーンのＢー８４６１を２．２部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体とプレポリマ−変性トリレンジイソシアネートを１４０部を用いて発泡させた。その時のポリオールとイソシアネートの液温は２０℃に調整した。まず、ポリオールとイソシアネートを攪拌し４５℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００７１】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．４ｍｍ、パック率１２５％で３．１ｍｍと従来の断熱材に比べて低減できることが判る。
【００７２】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２０℃、治具温度を４５℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００７３】
これらの結果を表１に併せて示す。表１から、コア層密度が３２．５ｋｇ／ｍ3と低密度で熱伝導率が１７．５ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１３ＭＰａと高く、低温寸法変化率が−１．１％、高温寸法変化率が１．４％と小さい値を示すことが判る。
【００７４】
さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０７ｍｍで試験後の最大歪み量も０．２７ｍｍと小さい値を示した。さらに、硬質ポリウレタンフォームの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレー）を組み込んで測定した結果、熱漏洩量が３．５％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【００７５】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【００７６】
〔実施例４〕
表１に示すポリオールＡ４５部とポリオールＢ１５部およびポリオールＣ１０部とポリオールＤ７部ポリオールＥ２０部とポリオールＦ３部にシクロペンタン発泡剤を１６部、水１．５部および反応触媒としてテトラメチルヘキサメチレンジアミン１．５部とペンタメチルジエチレントリアミン０．３部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドローＳ−トリアジン０．５部、整泡剤として有機シリコーンのＢ−８４６１を２．２部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体とプレポリマ−変性トリレンジイソシアネートを１３２部を用いて発泡させた。その時のポリオールとイソシアネートの液温は２０℃に調整した。
【００７７】
まず、ポリオールとイソシアネートを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００７８】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．６ｍｍ、パック率１２５％で３．２ｍｍと従来の断熱材に比べて低減できることがわかった。
【００７９】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２０℃、治具温度を４０℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００８０】
これらの結果を表１に併せて示す。表１から、コア層密度が３０．５ｋｇ／ｍ3と低密度で熱伝導率が１７．９ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１６ＭＰａと高く、低温寸法変化率が−０．９％、高温寸法変化率が１．６％と小さい値を示した。
【００８１】
さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０８ｍｍで試験後の最大歪み量も０．２９ｍｍと小さい値を示した。さらに、硬質ポリウレタンフォームの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレー）を組み込んで測定した結果、熱漏洩量が３％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【００８２】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【００８３】
〔比較例３〕
表１に示すプロピレンオキサイドで付加したｍ−トリレンジアミン系ポリエーテルポリオールＡ２０部とポリオールＢ３０部およびポリオールＣ１０部とポリオールＤ１０部とポリオールＥ２０部とポリオールＦ１０部にシクロペンタン発泡剤を１３部、水１．１部および反応触媒としてテトラメチルヘキサメチレンジアミン１．８部とペンタメチルジエチレントリアミン０．３部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．３部、整泡剤として有機シリコーンのＢ−８４６２を１．８部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体およびプレポリマ−変性トリレンジイソシアネートを１３５部を用いて発泡させた。その時のポリオールとイソシアネートの液温は２０℃に調整した。
【００８４】
まず、ポリオールとイソシアネートを攪拌し４５℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００８５】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で４．５ｍｍ、パック率１２５％で５．５ｍｍと大きくなることが判る。
【００８６】
次に、実施例１と同様に冷蔵庫および冷凍庫の外箱鉄板と内箱をウレタンフォームの発泡雇い治具にセット後、ポリオールとイソシアネートの液温を２０℃、治具温度を４５℃にして硬質ポリウレタンフォームを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１５％で発泡充填して冷蔵庫および冷凍庫の断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォームサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価し、さらに断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００８７】
これらの結果を表１に併せて示す。表１から、コア層密度が３５．８ｋｇ／ｍ3で熱伝導率が１８．３ｍＷ／ｍ・Ｋと高く、さらに圧縮強度も０．１２ＭＰａ、低温寸法変化率が−１．９％、高温寸法変化率が２．１％と変化が大きい値を示すことが判る。
【００８８】
さらに、冷蔵庫および冷凍庫の断熱箱体の低温放置試験を行った結果、外扉表鉄板の歪み試験前後の歪み量差は０．１５ｍｍで試験後の最大歪み量も０．６３ｍｍと大きくなり、断熱箱体の外扉鉄板に歪み変形が発生した。
【００８９】
〔実施例５〕
表１に示すポリオールＡ３０部とポリオールＢ２０部およびポリオールＣ２０部とポリオールＤ１０部とポリオールＥ２０部にシクロペンタン発泡剤を１４部、水１．６部および反応触媒としてテトラメチルヘキサメチレンジアミン１．５部とペンタメチルジエチレントリアミン０．３部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．５部、整泡剤として有機シリコーンのＢ−８４６１を２．２部配合した。また、イソシアネートとしてジフェニルメタンジイソシアネート多核体とプレポリマ−変性トリレンジイソシアネートを１４０部を用いて発泡させた。その時のポリオールとイソシアネートの液温は２０℃に調整した。
【００９０】
まず、ポリオールとイソシアネートを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モールド内に注入して、オーバーパックの１１５％と１２５％のパック率を用いて、発泡成型品をモールドから５分後に脱型させた硬質ポリウレタンフォームの膨れ量を測定した。
【００９１】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．４ｍｍ、パック率１２５％で２．９ｍｍと従来の断熱材に比べて低減できることがわかった。
【００９２】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォ−ムの発泡雇い治具にセット後、ポリオ−ルとイソシアネ−トの液温を２０℃、治具温度を４０℃にして硬質ポリウレタンフォ−ムを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォ−ムサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。
【００９３】
さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【００９４】
これらの結果を表１に併せて示す。表１から、コア層密度が３２ｋｇ／ｍ3と低密度で熱伝導率が１８ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１２ＭＰａと高く、低温寸法変化率が−０．８％、高温寸法変化率が１．５％と小さい値を示した。さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０９ｍｍで試験後の最大歪み量も０．２６ｍｍと小さい値を示した。
【００９５】
さらに、硬質ポリウレタンフォ−ムの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレ−）を組み込んで測定した結果、熱漏洩量が４％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【００９６】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【００９７】
〔比較例４〕
表１に示すプロピレンオキサイドで付加したｍ−トリレンジアミン系ポリエ−テルポリオ−ルＡ２５部とポリオ−ルＢ３５部およびポリオ−ルＣ２０部とポリオ−ルＤ１０部とポリオ−ルＦ５部にシクロペンタン発泡剤を１４部、水１．０部および反応触媒としてテトラメチルヘキサメチレンジアミン１．２部とペンタメチルジエチレントリアミン０．５部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．５部、整泡剤として有機シリコ−ンのＢ−８４６２を１．８部配合した。また、イソシアネ−トとしてジフェニルメタンジイソシアネ−ト多核体とプレポリマ−変性トリレンジイソシアネ−トを１４０部を用いて発泡させた。その時のポリオ−ルとイソシアネ−トの液温は２０℃に調整した。
【００９８】
まず、ポリオ−ルとイソシアネ−トを攪拌し４０℃に調整された６００×４００×７５ｍｍtのアルミ製モ−ルド内に注入して、オ−バ−パックの１１５％と１２５％のパック率を用いて、発泡成型品をモ−ルドから５分後に脱型させた硬質ポリウレタンフォ−ムの膨れ量を測定した。
【００９９】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で４．８ｍｍ、パック率１２５％で５．７ｍｍと大きくなることが判る。
【０１００】
次に、実施例１と同様に冷蔵庫および冷凍庫の外箱鉄板と内箱をウレタンフォ−ムの発泡雇い治具にセット後、ポリオ−ルとイソシアネ−トの液温を２０℃、治具温度を４０℃にして硬質ポリウレタンフォ−ムを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して冷蔵庫および冷凍庫の断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォ−ムサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価し、さらに断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【０１０１】
これらの結果を表１に併せて示す。表１から、コア層密度が３５．５ｋｇ／ｍ3で熱伝導率が１８．４ｍＷ／ｍ・Ｋと高く、さらに圧縮強度も０．１１ＭＰａと低く、低温寸法変化率が−１．８％、高温寸法変化率が１．９％と変化が大きい値を示す。
【０１０２】
さらに、冷蔵庫および冷凍庫の断熱箱体の低温放置試験を行った結果、外扉表鉄板の歪み試験前後の歪み量差は０．１９ｍｍで試験後の最大歪み量も０．５８ｍｍと大きくなり、断熱箱体の外扉鉄板に歪み変形が発生した。
【０１０３】
〔実施例６〕
表１に示すポリオ−ルＡ４０部とポリオ−ルＢ２３部およびポリオ−ルＣ１５部とポリオ−ルＤ５部とポリオ−ルＥ１５部とポリオ−ルＦ２部にシクロペンタン発泡剤を１５部、水１．４部および反応触媒としてテトラメチルヘキサメチレンジアミン１．５部とペンタメチルジエチレントリアミン０．２部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．４部、整泡剤として有機シリコ−ンのＢ−８４６１を２．２部配合した。また、イソシアネ−トとしてジフェニルメタンジイソシアネ−ト多核体とプレポリマ−変性トリレンジイソシアネ−トを１３５部を用いて発泡させた。その時のポリオ−ルとイソシアネ−トの液温は２０℃に調整した。
【０１０４】
まず、ポリオ−ルとイソシアネ−トを攪拌し４５℃に調整された６００×４００×７５ｍｍtのアルミ製モ−ルド内に注入して、オ−バ−パックの１１５％と１２５％のパック率を用いて、発泡成型品をモ−ルドから５分後に脱型させた硬質ポリウレタンフォ−ムの膨れ量を測定した。
【０１０５】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．６ｍｍ、パック率１２５％で３．１ｍｍと従来の断熱材に比べて低減できることが判る。
【０１０６】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォ−ムの発泡雇い治具にセット後、ポリオ−ルとイソシアネ−トの液温を２０℃、治具温度を４５℃にして硬質ポリウレタンフォ−ムを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１５％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォ−ムサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【０１０７】
これらの結果を表１に併せて示す。表１から、コア層密度が３１．５ｋｇ／ｍ3と低密度で熱伝導率が１７．９ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１５ＭＰａと高く、低温寸法変化率が−１．２％、高温寸法変化率が１．３％と小さい値を示した。さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０８ｍｍで試験後の最大歪み量も０．２７ｍｍと小さい値を示した。
【０１０８】
さらに、硬質ポリウレタンフォ−ムの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレ−）を組み込んで測定した結果、熱漏洩量が３％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【０１０９】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【０１１０】
〔実施例７〕
表１に示すポリオ−ルＡ４０部とポリオ−ルＢ２０部およびポリオ−ルＣ２０部とポリオ−ルＤ１０部とポリオ−ルＥ１０部にシクロペンタン発泡剤を１６部、水１．５部および反応触媒としてテトラメチルヘキサメチレンジアミン１．５部とペンタメチルジエチレントリアミン０．３部、トリス（３−ジメチルアミノプロピレン）ヘキサヒドロ−Ｓ−トリアジン０．５部、整泡剤として有機シリコ−ンのＢ−８４６１を２．２部配合した。また、イソシアネ−トとしてジフェニルメタンジイソシアネ−ト多核体とプレポリマ−変性トリレンジイソシアネ−トを１４０部を用いて発泡させた。その時のポリオ−ルとイソシアネ−トの液温は２０℃に調整した。
【０１１１】
まず、ポリオ−ルとイソシアネ−トを攪拌し４５℃に調整された６００×４００×７５ｍｍtのアルミ製モ−ルド内に注入して、オ−バ−パックの１１５％と１２５％のパック率を用いて、発泡成型品をモ−ルドから５分後に脱型させた硬質ポリウレタンフォ−ムの膨れ量を測定した。
【０１１２】
その結果を表１に示す。表１から、脱型５分後の膨れ量はパック率１１５％で２．３ｍｍ、パック率１２５％で２．８ｍｍと従来の断熱材に比べて低減できることが判る。
【０１１３】
次に、実施例１と同様に冷蔵庫および冷凍庫の箱体をウレタンフォ−ムの発泡雇い治具にセット後、ポリオ−ルとイソシアネ−トの液温を２０℃、治具温度を４５℃にして硬質ポリウレタンフォ−ムを空隙部分に発泡充填する。その際、注入容積は約２００リットルの箱体でゼロパックを設定後、パック率１１０％で発泡充填して断熱箱体を作製した。断熱箱体の底面中央部分から断熱材フォ−ムサンプルを採取して、コア層密度、熱伝導率、圧縮強度、低温寸法変化率、高温寸法変化率を評価した。さらに、断熱箱体の低温放置（−１０℃／４８時間）試験を行い、外箱表鉄板の歪み試験前後の歪み量の差および試験後の最大歪み量も評価した。
【０１１４】
これらの結果を表１に併せて示す。表１から、コア層密度が３２．９ｋｇ／ｍ3と低密度で熱伝導率が１７．８ｍＷ／ｍ・Ｋと低く、圧縮強度も０．１４ＭＰａと高く、低温寸法変化率が−１．４％、高温寸法変化率が１．１％と小さい値を示すことが判る。
【０１１５】
さらに、断熱箱体の外箱表鉄板の歪み試験前後の歪み量差は０．０７ｍｍで試験後の最大歪み量も０．２９ｍｍと小さい値を示した。さらに、硬質ポリウレタンフォ−ムの発泡充填を行った断熱箱体を形成した冷蔵庫および冷凍庫に、冷凍サイクル部品（圧縮機／コンデンサ／エバポレ−）を組み込んで測定した結果、熱漏洩量が３％低減して消費電力量も約１Ｋｗｈ／月の省エネ化が達成された。
【０１１６】
このことから、本実施例に係る硬質ポリウレタンフォームでは、充填する際の膨れ量が小さく、また低密度であり、熱伝導率の低減、圧縮強度、寸法安定性にも優れる硬質ポリウレタンフォームとなる。また、本実施例に係る硬質ポリウレタンフォームを冷蔵庫の断熱材として充填することによって、熱漏洩量が低減され消費電力を低減できる。さらに断熱材の充填量が低減され冷蔵庫のコストを低減できる。また、低温で放置しても冷蔵庫の歪み変形が小さくなり冷蔵庫の外観品質が優れたものとなる。
【０１１７】
【発明の効果】
本発明によれば、表面の歪み変形が防止され外観品質の優れた冷蔵庫を提供できる。
【図面の簡単な説明】
【図１】冷蔵庫および冷凍庫の断熱箱体および断熱扉にウレタンが充填された断熱材の縦断面図である。
【図２】断熱箱体にウレタンを４点発泡充填する模式図とウレタン測定サンプル採取の模式図である。
【符号の説明】
１…冷蔵庫本体、 ２…内箱、 ３…冷蔵室、 ４…野菜室、 ５…冷凍室、６…冷蔵室扉、 ７…野菜室扉、 ８…上段冷凍室扉、 ９…下段冷凍室扉、１０…ウレタン断熱材、 １１…ウレタン注入ヘッド、 １２…ウレタンの流れ、１３…ウレタン注入口、 １４…サンプル採取位置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerator filled with rigid polyurethane foam.
[0002]
[Prior art]
A heat insulating material using a rigid polyurethane foam having air bubbles in the space between the outer box and the inner box is used for the heat insulating box of the refrigerator. This rigid polyurethane foam is obtained by reacting a polyol component and an isocyanate component in the presence of a foaming agent, a catalyst, and a foam stabilizer. As a conventional foaming agent, trichloromonofluoromethane having low gas thermal conductivity and hardly decomposable has been used for a heat insulating box.
[0003]
However, if it is released into the atmosphere, the ozone layer in the stratified garden will be destroyed and the surface temperature will rise due to the greenhouse effect. The alternative 1,1-dichloro-1-monofluoroethane will be used as a foaming agent for heat insulation members. Although it was used, it is also subject to regulation and is scheduled to be abolished in 2003.
[0004]
On the other hand, as for the so-called non-fluorocarbon foaming agent, in which the destruction of the ozone layer is reduced by not using chlorofluorocarbon, hydrocarbon compounds such as cyclopentane foaming agents have begun to be used as heat insulating materials for refrigerators mainly in Europe. For example, low density, high-rigidity rigid polyurethane foam using a mixed foaming agent of cyclopentane and isopentane, and rigid polyurethane foam having low density and high fluidity, using a mixed foaming agent of cyclopentane and water are used. Insulation boxes and insulation doors for refrigerators and freezers have been proposed. Such conventional techniques are disclosed in JP-A-11-140155, JP-A-11-201628, and JP-A-11-248344.
[0005]
[Problems to be solved by the invention]
However, cyclopentane and isopentane hydrocarbon-based blowing agents have a problem that the thermal conductivity of the gas is high and the heat insulation performance is greatly inferior compared with conventional blowing agents. In particular, a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water is desired to develop a urethane material capable of saving energy by improving heat insulation properties from the viewpoint of global warming and protection of the global environment.
[0006]
On the other hand, storage boxes installed at different temperatures (−18 ° C., 0 ° C., 3 ° C., 5 ° C., etc.) according to the size of the refrigerator and the freezer, the ingredients, and the type of food are in the refrigerator at the top and in the middle. Diversification is progressing with a vegetable room and an upper freezer room and a lower freezer room at the bottom.
[0007]
For this reason, in recent years, with the demands for larger refrigerators and freezers and space saving, the space in the cabinet walls has become narrower and more complicated, and copper pipes, aluminum tape, paper tape, polystyrene pieces, and wiring obstacles Has a large number on the outer surface of the inner box, the foam is less likely to flow inside the refrigerator wall, resulting in incomplete filling of this portion. Solve this and heaven well A urethane material having a low density and good fluidity is preferable for forming a uniform foam at the bottom, bottom, back, handle, and hinge. For this reason, there is an urgent need to develop a material that can reduce the thermal conductivity and secure the strength of the urethane material, which is a mixed foaming agent of cyclopentane and water, as in the case of alternative chlorofluorocarbon.
[0008]
Therefore, the low-density rigid polyurethane foam using a mixed foaming agent of cyclopentane and water has a small amount of foam expansion, a small distortion deformation of the outer case iron plate when left at low temperature, and a thermal conductivity. It is required as a requirement for a heat insulating material that both reduction and compressive strength and dimensional stability are compatible.
[0009]
The formation of bubbles foamed in the polyurethane resin is not only the physical structure such as the generation and growth of bubbles controlled by the amount of foaming agent, the amount of water, catalyst, foam stabilizer, along with the chemical structure of polyol and isocyanate, The compatibility, reactivity, and fluidity during the foaming process of each raw material are thought to have a significant effect. For this reason, in order to satisfy the above requirements, it is necessary to optimize each material.
[0010]
However, a rigid polyurethane foam using a cyclopentane foaming agent has a lower saturated vapor pressure than an alternative fluorocarbon foaming agent, so that the pressure in the cells of the cells is also reduced, and shrinkage after filling tends to occur. For this reason, if the density to be filled is too low, the surface is deformed and the yield of the product is lowered, or the strength of the box and the door is lowered.
[0011]
That is, in the low-density rigid polyurethane foam, the influence of the expansion / contraction of the gas in the bubbles is added, so that the linear expansion coefficient of the foam increases. Here, in filling low-density rigid polyurethane foam, if the amount of filling is increased in order to maintain the shape of the product even if shrinkage occurs after filling, the expansion rate and swelling amount of the box and door during filling will be increased. Will increase. In addition, until now, high-density urethane materials have been mainly used, but due to poor foam fluidity, strength has been promoted by increasing the foaming pressure and increasing the urethane filling amount. There is also a problem that liquid leakage of the urethane foam is likely to occur.
[0012]
In order to achieve compatibility between characteristics using low-density rigid polyurethane foams, the present inventors adjusted the main raw material polyol and isocyanate, foaming agent that forms bubbles, water, the catalyst controlling the reactivity, and interfacial phenomena. The foam stabilizer was examined. Specifically, low-density rigid polyurethane foam reduces the amount of expansion during urethane foam demolding, changes in mold temperature during foaming, and changes in the packing rate of the filling amount. Various proposals were made to optimize the composition of raw materials to find a rigid polyurethane foam with a reduced rate and excellent compressive strength and dimensional stability.
[0013]
An object of the present invention is to provide a refrigerator having excellent appearance quality in which distortion of the surface is prevented from being deformed.
[0014]
[Means for Solving the Problems]
The above object is provided in a refrigerator provided with a heat insulating material filled with a rigid polyurethane foam using at least a polyol, an aromatic isocyanate, and a mixed foaming agent of cyclopentane and water as a blowing agent in a space between the outer box and the inner box. Contains 3 or more components in which an initiator composed of m-tolylenediamine and o-tolylenediamine as a polyol component is added with ethylene oxide and / or propylene oxide In addition, an initiator composed of o-tolylenediamine is used in a smaller amount than an initiator composed of m-tolylenediamine. Filled with rigid polyurethane foam Interruption Achieved with thermal material.
[0015]
Furthermore, the polyol component of the rigid polyurethane foam contains 90% or more of a mixture obtained by adding an initiator composed of m-tolylenediamine, o-tolylenediamine, bisphenol A, and triethanolamine with ethylene oxide and / or propylene oxide. It is a polyether polyol, and the density of the core layer heat insulating material having a thickness of about 20 to 25 mm from a plane portion at least 500 mm or more away from the urethane inlet is 29 to 33 kg / m 3, and the thermal conductivity is 17.5 at an average temperature of 10 ° C. This is achieved by using the heat insulating material having ˜18.0 mW / m · K. Furthermore, the aromatic isocyanate component of the rigid polyurethane foam uses a mixture of prepolymer-modified tolylene diisocyanate with diphenylmethane diisocyanate polynuclear, and 1.2 to 1.6 parts by weight of water with respect to 100 parts by weight of polyol. This is achieved by using the thermal insulation reacted in a mixed blowing agent combined with 14-18 parts by weight of cyclopentane.
[0016]
The polyol component of the rigid polyurethane foam is 45 to 55 parts by weight of a polyol having an OH number of 400 to 500 obtained by adding propylene oxide and ethylene oxide and propylene oxide to m-tolylenediamine, and propylene oxide to o-tolylenediamine. 10 to 20 parts by weight of a polyol having an OH number of 450 to 500 obtained by addition with ethylene oxide and 10 to 20 parts by weight of a polyol having an OH number of 350 to 450 obtained by adding propylene oxide to triethanolamine, bisphenol A 10 to 20 parts by weight of a polyol having an OH number of 250 to 300 obtained by adding propylene oxide to triethanol, 3 to 8 parts by weight of a polyol having an OH number of 450 to 480 obtained by adding propylene oxide to diethanolamine, trimethylo The trimethylolpropane OH number 1256 consists of a mixture of 2 to 5 parts by weight, rigid polyurethane foams average OH number of the polyol is 400 to 450 is achieved by using the heat insulating material filled.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
In order to develop an optimal low-density rigid polyurethane foam for a heat insulating box used for a refrigerator and a freezer, the present inventors reduced the amount of swelling with a mixed foaming agent of cyclopentane and water, and reduced thermal conductivity. The optimum polyol that can achieve both compressive strength and dimensional stability was selected.
[0018]
First, in order to reduce the amount of swelling of the foam and to achieve both reduction in thermal conductivity and compression strength and dimensional stability, an attempt was made to introduce a large amount of an initiator polyol having an aromatic ring that easily causes steric hindrance.
[0019]
However, when the aromatic ring addition polymer is used as a single component in a large amount or mixed with a different component such as polyester polyol, the compatibility of the polyether polyol component is extremely lowered. As a result, there is a problem that turbidity is likely to occur during premixing, the varnish viscosity changes during storage stability, and the filling amount during foaming tends to fluctuate.
[0020]
Therefore, as the optimum polyol used in the present application, as a result of examining various alkylene oxides and the amount of swelling, it has been found that those which are easily dissolved in the cyclopentane blowing agent are effective for foam swelling. Accordingly, an addition polymerization product of propylene oxide was mainly selected, and in order to make other physical properties compatible, ethylene oxide was also used in combination, and a polyether polyol containing no different components such as polyester polyol was obtained.
[0021]
Furthermore, m-tolylenediamine is normally used in aromatic rings, and in order to achieve compatibility of various properties, o-tolylenediamine, which is expected to be highly reactive and cure with m-tolylenediamine addition polymer. It was found that a three-component polyether polyol combined with an addition polymer was effective for the amount of swelling.
[0022]
However, the o-tolylenediamine adduct has a higher varnish viscosity than the m-tolylenediamine adduct, and is likely to be highly reactive. There is a problem that is likely to occur. Therefore, when mixing the o-tolylenediamine adduct, in order to obtain a reduction in varnish viscosity and a balance in reactivity, it should be used in a smaller amount than the m-tolylenediamine adduct and m-tolylenediamine. In order to improve the strength and compatibility of the amine adduct, a propylene oxide adduct and both propylene oxide and ethylene oxide adduct were used in combination.
[0023]
Furthermore, in order to obtain a balance of properties in addition to the initiator having an aromatic ring, an optimal matrix is obtained by adding a polymer added with propylene oxide using a bisphenol A-based initiator as the third component and a triethanolamine-based initiator as the fourth component. Selected over 90% of the ingredients.
[0024]
In order to achieve both reduction of thermal conductivity and compressive strength and dimensional stability, the isocyanate component was selected as a component in which prepolymer-modified tolylene diisocyanate was mixed with a commonly used diphenylmethane diisocyanate polynuclear body. The reason for this is that when diphenylmethane diisocyanate polynuclear body is used, the initial reaction is slow, but the reaction tends to increase the viscosity rapidly, and it turns out that obstacles to fluidity and bubble coalescence are likely to occur. This is because. Therefore, by mixing prepolymer-modified tolylene diisocyanate, the thickening behavior is mild, the concentration of urethane bonds and urea bonds is increased, and the distance between crosslink points is shortened to form uniform fine cells. Was selected.
[0025]
Furthermore, the optimum blending ratio of cyclopentane and water, the amount of swelling of the catalyst and foam stabilizer were reduced, and as a result of studying both low density, reduced thermal conductivity, compression strength and dimensional stability, cyclopentane and water The optimum blending ratio is that 1.2 to 1.6 parts by weight of water and 14 to 18 parts by weight of cyclopentane are combined with 100 parts by weight of polyol, and the main catalyst is trimethylaminoethylpiperazine, pentamethyldiethylenetriami and tris ( A trimerization catalyst such as 3-dimethylaminopropylene) hexahydro-S-triazine was used in combination, and a foam stabilizer having a low surface tension was selected by increasing the rapid reaction and curing properties, thereby completing the present invention.
[0026]
In order to obtain a urethane material that achieves the object of the present invention, the amount of water added to the cyclopentane blowing agent and the auxiliary blowing agent is greatly affected. In general, the density can be easily reduced by using a large amount of both cyclopentane and water.
[0027]
However, when the water content is increased, the amount of blistering and thermal conductivity increases due to an increase in the partial pressure of carbon dioxide in the bubble cell, and when the amount of cyclopentane increases, the compressive strength and dimensional stability tend to be poor. It is done. Therefore, the optimum blending ratio of cyclopentane and water is preferably a combination of 1.2 to 1.6 parts by weight of water and 14 to 18 parts by weight of cyclopentane with respect to 100 parts by weight of polyol.
[0028]
Further, as a result of examining the amount of expansion of the foam, there is a tendency that the amount of expansion of the foam becomes larger as the thickness of the heat insulation panel differs. It is considered that the thicker the panel, the higher the internal temperature of the foam when the heat-insulating material reacts, and the larger the temperature difference between expansion and contraction. Further, when urethane is poured into a box of an actual refrigerator and a freezer and left at a low temperature, there is a problem that appearance deformation of the left and right side iron plate distortion is likely to occur in the box.
[0029]
Examples of the polyol used in the present invention include polyhydric alcohols such as dihydric alcohols such as propylene glycol and dipropylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, diglycerin, methyl glucoside, sorbitol, and sucrose. And trihydric or higher polyhydric alcohols. Alkylene polyamines such as ethylenediamine and diethylenetriamine are used as polyvalent amines, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine and the like as alkanolamines, 2,4-tolylenediamine as aromatic polyvalent amines, 2,3- Tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine, and the like, diaminodiphenylmethane, bisphenol A, polymethylene polyphenylpolyamine, and the like are used.
[0030]
When the average OH value of the polyether polyol mixture composition is less than 400, the compressive strength and dimensional stability are poor, and when it exceeds 450, the foam becomes brittle. The average OH value is a preferable result in producing a rigid polyurethane foam having a stable 400-450.
[0031]
Examples of the reaction catalyst include tertiary amines such as trimethylaminoethylpiperazine, pentamethyldiethylenetriamine, tetramethylhexamethylenediamine, triethylenediamine and tetramethylethylenediamine, and tris (3-dimethylaminopropylene) hexahydro-S-triazine. If the reactivity matches, such as a trimerization catalyst and a slow-acting catalyst used in combination with dipropylene glycol, they can be used.
[0032]
The compounding amount of the reaction catalyst is preferably 2 to 5 parts by weight per 100 parts by weight of the polyol component. Furthermore, for example, B-8462 and B-8461 manufactured by Goldschmidt, X-20-1614 and F-392 manufactured by Shin-Etsu Chemical, and SZ-1127 manufactured by Nihon Unica, Inc. Therefore, those suitable for relatively low emulsifying action with Si molecular weight of 1800 to 3000 and Si content of 25 to 30 are preferable. The blending amount of the foam stabilizer is 1.5 to 4 parts by weight per 100 parts by weight of the polyol component.
[0033]
As the isocyanate, polynuclear diphenylmethane diisocyanate and prepolymer-modified tolylene diisocyanate are mainly used. Tolylene diisocyanate is a mixture of isomers, namely 2,4-isomer 100%, 2,4-isomer / 2, 6-isomer = 80/20, 65/35 (weight ratio) as well as trade name Mitsui Cosmonate TRC Also, prepolymer urethane-modified tolylene diisocyanate, allophanate-modified tolylene diisocyanate, biuret-modified tolylene diisocyanate, isocyanurate-modified tolylene diisocyanate, such as Takenate 4040 manufactured by Takeda Pharmaceutical Co., Ltd. can be used.
[0034]
In addition, as the 4,4′-diphenylmethane diisocyanate, in addition to a pure product as a main component, trade name Mitsui Cosmonate M-200 containing a polyhedron of three or more nuclei, Millionate MR manufactured by Takeda Pharmaceutical Co., Ltd. Diphenylmethane diisocyanate polynuclear materials such as can be used. In addition, isocyanates such as aromatic polyfunctional isocyanates such as polymethylene polyphenyl isocyanate, toluidine isocyanate, and xylylene diisocyanate, and carbodiimide-modified diphenylmethane diisocyanate can also be used.
[0035]
The rigid polyurethane foam of the present invention can be formed by a commonly used foaming machine, for example, a PU-30 type foaming machine manufactured by Promart. Although the foaming conditions vary somewhat depending on the type of foaming machine, the liquid temperature is preferably 18 to 30 ° C., the discharge pressure is 80 to 150 kg / cm 2, the discharge amount is 15 to 30 kg / min, and the mold box temperature is preferably 35 to 45 ° C. More preferably, the liquid temperature is 20 ° C., the discharge pressure is 100 kg / cm 2, the discharge amount is 25 kg / min, and the mold box temperature is around 45 ° C.
[0036]
In this way, it is a rigid polyurethane foam having bubbles of independent structure and using a mixed foaming agent of cyclopentane and water, which has a small amount of swelling when filled, low density, and thermal conductivity. By filling a rigid polyurethane foam excellent in reduction, compressive strength, and dimensional stability as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. In addition, a refrigerator having excellent appearance quality can be provided by reducing distortion of the refrigerator even when left at a low temperature.
[0037]
Examples of the present invention and comparative examples will be described below in detail. In the following Examples and Comparative Examples, parts or% represents parts by weight and% by weight, respectively.
[0038]
[Example 1]
As the polyol component, 50 parts of propylene oxide having an average hydroxyl value of 450 and m-tolylenediamine-based polyether polyol (referred to as polyol A) added with propylene oxide and ethylene oxide, average hydroxyl value. 13 parts of o-tolylenediamine-based polyether polyol (referred to as polyol B) added with propylene oxide of 480 and triethanolamine-based polyether polyol added with propylene oxide having an average hydroxyl value of 400 15 parts of polyol (referred to as polyol c), 4 parts of a diethylamine-based polyether polyol (referred to as polyol D) added with propylene oxide having an average hydroxyl value of 460, and an average hydroxyl value of 280 Bisphenol A-based polyester polyol added with propylene oxide The blending amount of the cyclopentane blowing agent is 100 parts of a mixed polyol component of 15 parts (referred to as Polyol E) and 3 parts of trimethylolpropane having an average hydroxyl value of 1256 (referred to as Polyol F). 16 parts, 1.5 parts of water and 1.7 parts of trimethylaminoethylpiperazine as reaction catalyst, 0.2 part of pentamethyldiethylenetriamine, 0.4 part of tris (3-dimethylaminopropylene) hexahydro-S-triazine, foam stabilizer 2 parts of organic silicone F-392 was blended.
[0039]
Further, 137 parts of a mixture of diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed as an isocyanate component. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C. First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mm aluminum mold adjusted to 45 ° C. to deform the outer case iron plate of the refrigerator and freezer box. The amount of blistering affected was measured. At that time, since the amount of swelling increases with the overpack, a 75 mmt insulation panel made of hard polyurethane foam was removed from the mold after 5 minutes at both pack rates of 115% and 125%. Using this, the amount of swelling due to fluctuations in the pack rate was measured. The results are shown in Table 1.
[0040]
[Table 1]

[0041]
This table shows the physical properties of the insulation material (mold swell amount, core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, high temperature dimensional change rate, difference in strain before and after the test, using aluminum mold panels and heat insulation boxes. , The maximum strain after the test). From Table 1, it was found that the amount of swelling after 5 minutes from demolding can be reduced to 2.3 mm at a pack rate of 115% and 2.7 mm at a pack rate of 125% as compared with a conventional heat insulating material.
[0042]
Next, since the evaluation was performed with the actual box using the above materials, the results will be described below. In that case, it demonstrates below, referring drawings.
[0043]
FIG. 1 is a longitudinal sectional view in which a refrigerator compartment door 6, a vegetable compartment door 7, an upper freezer compartment door 8, and a lower freezer compartment door 9 are installed in a box 1 of a refrigerator and a freezer. First, after setting the outer box iron plate and the inner box resin wall box to a urethane foam foaming jig, the liquid temperature of polyol and isocyanate is set to 20 ° C and the jig temperature is set to 45 ° C, and the rigid polyurethane foam is foamed in the gap. Fill. At that time, the polyol and isocyanate of the urethane foam caused a chemical reaction, and the foamed urethane foam was injected and filled into the space in the wall of the box by pressurization by the foaming pressure, thereby producing a heat insulating box. At that time, after setting a zero pack of urethane material (minimum injection amount necessary for actual machine filling) with a box having an injection volume of about 200 liters, injection was performed at a 110% pack rate of overpack.
[0044]
FIG. 2 shows a schematic diagram in which urethane is filled into a heat-insulated box by four-point foaming and a schematic diagram of collecting a urethane measurement sample. A thermal insulation foam sample was collected from the bottom center part of the thermal insulation box of the refrigerator and freezer, and various physical properties were evaluated. First, the core layer density is 200 mm × 200 mm × 20 mmt after measuring the sample size and weight, and the value obtained by dividing the weight by volume and the thermal conductivity are also HC-073 type manufactured by Eihiro Seiki Co., Ltd. (heat flow meter method, average temperature 10 ° C.) Was used to evaluate.
[0045]
The compressive strength was evaluated by a value obtained by deforming a foam sample of 50 mm × 50 mm × 20 mmt at a feeding speed of 4 mm / min and dividing the stress at the time of 10% deformation by the original pressure receiving area. The low temperature dimensional change rate and the high temperature dimensional change rate were evaluated by changing the thickness when a 150 mm × 300 mm × 20 mmt foam was left at −20 ° C. for 24 hours or 70 ° C. for 24 hours.
[0046]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 29.2 kg / m 3, the thermal conductivity is as low as 17.6 mW / m · K, the compressive strength is as high as 0.15 MPa, and the low temperature dimensional change rate is −1.1. %, The high temperature dimensional change rate is 1.6%, and the change is small.
[0047]
Furthermore, the amount of strain on the outer box surface iron plate was measured using a strain measuring instrument in which a dial gauge was attached to the center of a square bar having a smooth surface of 300 mm in length. The measurement method is represented by the maximum value of strain when a measuring instrument is applied to the outer box surface iron plate surface. As for the amount of strain on the side of the box, first, the amount of strain before the test is measured and its distribution is clearly shown, and then left in a thermostatic chamber at -10 ° C for 48 hours. Thereafter, the amount of strain was measured immediately after taking out from the temperature-controlled room in the same manner as before the test, and the difference in strain amount before and after the test and the maximum strain amount after the test were evaluated.
[0048]
These results are also shown in Table 1. From Table 1, it can be seen that the strain difference before and after the test is 0.1 mm and the maximum strain is as small as 0.3 mm.
[0049]
Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 4% and consumed. Energy savings of about 1 Kwh / month were achieved.
[0050]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0051]
[Comparative Example 1]
60 parts of polyol A shown in Table 1, 20 parts of polyol C, 20 parts of polyol D, 12 parts of cyclopentane blowing agent, 1.7 parts of water and 1.8 parts of tetramethylhexamethylenediamine and 0.3 part of pentamethyldiethylenetriamine as a reaction catalyst , 0.5 parts of tris (3-dimethylaminopropylene) hexahydro-S-triazine and 1.8 parts of organic silicone B-8462 as a foam stabilizer were blended. Moreover, it foamed using 140 parts of diphenylmethane diisocyanate polynuclear bodies as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0052]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the foam-molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0053]
Table 1 shows the results of the term. From Table 1, it can be seen that the amount of swelling after 5 minutes from demolding increases to 4.9 mm at a pack rate of 115% and 5.6 mm at a pack rate of 125%.
[0054]
Next, as in Example 1, after setting the outer box iron plate and inner box of the refrigerator and freezer on a urethane foam foaming jig, the polyol and isocyanate liquid temperatures were set to 20 ° C. and the jig temperature was set to 40 ° C. Polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body with an injection volume of about 200 liters, and foam filling was performed at a pack rate of 110% to produce a heat insulating box body for a refrigerator and a freezer. A heat insulation foam sample is taken from the center of the bottom of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, high temperature dimensional change rate are evaluated. (10 ° C./48 hours) test was performed, and the difference in strain amount before and after the strain test of the outer case front iron plate and the maximum strain amount after the test were also evaluated.
[0055]
These results are also shown in Table 1. From Table 1, the core layer density is 34.5 kg / m 3, the thermal conductivity is as high as 18.5 mW / m · K, the compressive strength is also 0.11 MPa, the low temperature dimensional change is -2.1%, and the high temperature dimensional change It can be seen that the rate is as large as 1.8%.
[0056]
Furthermore, as a result of leaving the heat insulation box of the refrigerator and the freezer at a low temperature, the difference in distortion amount between the outer door front iron plate and the distortion test is 0.22 mm, and the maximum distortion amount after the test is as large as 0.66 mm. Distortion deformation occurred in the outer door iron plate of the body.
[0057]
[Example 2]
40 parts of polyol A, 30 parts of polyol B, 28 parts of polyol E, 2 parts of polyol F, 17 parts of cyclopentane blowing agent, 1.3 parts of water and 1.5 parts of tetramethylhexamethylenediamine and pentamethyldiethylenetriamine as reaction catalysts shown in Table 1 0.2 part, 0.6 part of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and 2.2 parts of organic silicone B-8461 as a foam stabilizer were blended. Further, 135 parts of diphenylmethane diisocyanate polynuclear body and prepolymer-modified tolylene diisocyanate were foamed as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 25 ° C.
[0058]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the foam-molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0059]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding can be reduced to 2.4 mm at a pack rate of 115% and 2.9 mm at a pack rate of 125%, compared to a conventional heat insulating material.
[0060]
Next, after setting the refrigerator and freezer box in a urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was 25 ° C., the jig temperature was 40 ° C., and the rigid polyurethane foam was voided. Fill the part with foam. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 115% to produce a heat insulating box body. A heat insulating material foam sample was collected from the bottom center part of the heat insulating box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated. Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0061]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 31.8 kg / m 3, the thermal conductivity is as low as 17.8 mW / m · K, the compressive strength is also 0.14 MPa, the low temperature dimensional change is −1.3%, and the high temperature It can be seen that the dimensional change rate is as small as 1.5%.
[0062]
Further, the strain difference between before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.09 mm, and the maximum strain after the test was as small as 0.29 mm. Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 3% and consumed. Energy savings of about 1 Kwh / month were achieved.
[0063]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0064]
[Comparative Example 2]
In Table 1, 60 parts of polyol B, 10 parts of polyol C, 20 parts of polyol D, 10 parts of polyol E, 11 parts of cyclopentane blowing agent, 1.4 parts of water, and 1.2 parts of tetramethylhexamethylenediamine as a reaction catalyst and pentamethyldiethylenetriamine 0.5 parts, 0.6 parts of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and 1.8 parts of organic silicone B-8462 as a foam stabilizer were blended. Further, 137 parts of a mixture of diphenylmethane diisocyanate polynuclear and prepolymer-modified tolylene diisocyanate was used as the isocyanate for foaming. The liquid temperature of the polyol and isocyanate at that time was adjusted to 25 ° C.
[0065]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the foam-molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0066]
The results are shown in Table 1. From Table 1, it can be seen that the swelling amount after 5 minutes from demolding increases to 4.1 mm at a pack rate of 115% and 5.2 mm at a pack rate of 125%.
[0067]
Next, as in Example 1, after setting the outer box iron plate and inner box of the refrigerator and freezer to a urethane foam foaming jig, the liquid temperature of polyol and isocyanate was set to 25 ° C. and the jig temperature was set to 40 ° C. Polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and foam filling was performed at a pack rate of 115% to produce a heat insulating box body for a refrigerator and a freezer. A heat insulation foam sample is taken from the center of the bottom of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, high temperature dimensional change rate are evaluated. (10 ° C./48 hours) test was performed, and the difference in strain amount before and after the strain test of the outer case front iron plate and the maximum strain amount after the test were also evaluated.
[0068]
These results are also shown in Table 1. From Table 1, the core layer density is 35.2 kg / m 3, the thermal conductivity is as high as 18.8 mW / m · K, the compressive strength is as low as 0.09 MPa, the low temperature dimensional change rate is −2.3%, and the high temperature It can be seen that the dimensional change rate is as large as 2.2%.
[0069]
Furthermore, as a result of conducting a low temperature standing test of the heat insulation box of the refrigerator and freezer, the difference in strain amount before and after the strain test of the outer door front iron plate is 0.16 mm and the maximum strain amount after the test is as large as 0.56 mm. Distortion deformation occurred in the outer door iron plate of the box.
[0070]
Example 3
30 parts of polyol A, 20 parts of polyol B, 20 parts of polyol C, 10 parts of polyol D and 20 parts of polyol E shown in Table 1, 18 parts of cyclopentane blowing agent, 1.2 parts of water and 1.7 parts of tetramethylhexamethylenediamine as a reaction catalyst And 0.3 parts of pentamethyldiethylenetriamine, 0.5 parts of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and 2.2 parts of organic silicone B-8461 as a foam stabilizer were blended. Further, diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed using 140 parts as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C. First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 45 ° C., and the foam molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0071]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding can be reduced to 2.4 mm at a pack rate of 115% and 3.1 mm at a pack rate of 125% as compared with the conventional heat insulating material.
[0072]
Next, after setting the refrigerator and freezer box on a urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was set to 20 ° C., the jig temperature was set to 45 ° C., and the rigid polyurethane foam was voided. Fill the part with foam. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 110% to produce a heat insulating box body. A heat insulating material foam sample was collected from the bottom center part of the heat insulating box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated. Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0073]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 32.5 kg / m3, the thermal conductivity is as low as 17.5 mW / m · K, the compressive strength is as high as 0.13 MPa, and the low temperature dimensional change rate is -1.1%. It can be seen that the high temperature dimensional change rate is as small as 1.4%.
[0074]
Further, the difference in strain amount before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.07 mm, and the maximum strain amount after the test was as small as 0.27 mm. Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 3.5%. Energy savings of about 1 Kwh / month were achieved.
[0075]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0076]
Example 4
45 parts of polyol A, 15 parts of polyol B, 10 parts of polyol C, 7 parts of polyol D, 20 parts of polyol E, 3 parts of polyol F, 16 parts of cyclopentane blowing agent, 1.5 parts of water and tetramethylhexamethylenediamine 1 as a reaction catalyst shown in Table 1 0.5 part, 0.3 part of pentamethyldiethylenetriamine, 0.5 part of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and 2.2 parts of organic silicone B-8461 as a foam stabilizer were blended. Further, diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed using 132 parts as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0077]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the foam-molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0078]
The results are shown in Table 1. From Table 1, it was found that the amount of swelling after 5 minutes from demolding can be reduced to 2.6 mm at a pack rate of 115% and 3.2 mm at a pack rate of 125% as compared with the conventional heat insulating material.
[0079]
Next, after setting the refrigerator and freezer box on the urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was set to 20 ° C., the jig temperature was set to 40 ° C., and the rigid polyurethane foam was voided. Fill the part with foam. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 110% to produce a heat insulating box body. A heat insulating material foam sample was collected from the bottom center part of the heat insulating box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated. Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0080]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 30.5 kg / m 3, the thermal conductivity is as low as 17.9 mW / m · K, the compressive strength is as high as 0.16 MPa, and the low temperature dimensional change is −0.9%. The high temperature dimensional change rate was as small as 1.6%.
[0081]
Further, the difference in strain amount before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.08 mm, and the maximum strain amount after the test was as small as 0.29 mm. Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 3% and consumed. Energy savings of about 1 Kwh / month were achieved.
[0082]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0083]
[Comparative Example 3]
13 parts of cyclopentane foaming agent in 20 parts of m-tolylenediamine-based polyether polyol A, 30 parts of polyol B, 10 parts of polyol C, 10 parts of polyol D, 20 parts of polyol E and 10 parts of polyol F shown in Table 1 and water 1.1 parts, 1.8 parts of tetramethylhexamethylenediamine as a reaction catalyst, 0.3 parts of pentamethyldiethylenetriamine, 0.3 parts of tris (3-dimethylaminopropylene) hexahydro-S-triazine, organosilicone as a foam stabilizer Of B-8462 was blended. Further, 135 parts of diphenylmethane diisocyanate polynuclear body and prepolymer-modified tolylene diisocyanate were foamed as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0084]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 45 ° C., and the foam molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0085]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding increases to 4.5 mm at a pack rate of 115% and 5.5 mm at a pack rate of 125%.
[0086]
Next, as in Example 1, after setting the outer box iron plate and inner box of the refrigerator and freezer to a urethane foam foaming jig, the liquid temperature of polyol and isocyanate was set to 20 ° C. and the jig temperature was set to 45 ° C. Polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and foam filling was performed at a pack rate of 115% to produce a heat insulating box body for a refrigerator and a freezer. A heat insulation foam sample is taken from the center of the bottom of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, high temperature dimensional change rate are evaluated. (10 ° C./48 hours) test was performed, and the difference in strain amount before and after the strain test of the outer case front iron plate and the maximum strain amount after the test were also evaluated.
[0087]
These results are also shown in Table 1. From Table 1, the core layer density is 35.8 kg / m 3, the thermal conductivity is as high as 18.3 mW / m · K, the compressive strength is also 0.12 MPa, the low temperature dimensional change rate is -1.9%, and the high temperature dimensional change. It can be seen that the rate is as large as 2.1%.
[0088]
Furthermore, as a result of conducting a low temperature standing test of the heat insulation box of the refrigerator and the freezer, the difference in strain amount before and after the strain test of the outer door front iron plate is 0.15 mm and the maximum strain amount after the test is as large as 0.63 mm. Distortion deformation occurred in the outer door iron plate of the box.
[0089]
Example 5
30 parts of polyol A, 20 parts of polyol B, 20 parts of polyol C, 10 parts of polyol D and 20 parts of polyol E shown in Table 1, 14 parts of cyclopentane blowing agent, 1.6 parts of water and 1.5 parts of tetramethylhexamethylenediamine as a reaction catalyst And 0.3 part of pentamethyldiethylenetriamine, 0.5 part of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and 2.2 parts of organic silicone B-8461 as a foam stabilizer were blended. Further, diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed using 140 parts as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0090]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the foam-molded product is removed from the mold using a pack ratio of 115% and 125% of the overpack. The amount of swelling of the rigid polyurethane foam demolded after 5 minutes was measured.
[0091]
The results are shown in Table 1. From Table 1, it was found that the amount of swelling after 5 minutes from demolding can be reduced to 2.4 mm at a pack rate of 115% and 2.9 mm at a pack rate of 125% as compared with the conventional heat insulating material.
[0092]
Next, after setting the refrigerator and freezer box on a urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was 20 ° C, and the jig temperature was 40 ° C. Then, the rigid polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 110% to produce a heat insulating box body. A thermal insulation form sample was taken from the bottom center part of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated.
[0093]
Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0094]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 32 kg / m3, the thermal conductivity is as low as 18 mW / m · K, the compressive strength is as high as 0.12 MPa, the low-temperature dimensional change rate is -0.8%, and the high-temperature dimensional change is high. The rate was as small as 1.5%. Furthermore, the difference in strain amount before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.09 mm, and the maximum strain amount after the test was as small as 0.26 mm.
[0095]
Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 4%. As a result, energy savings of about 1 Kwh / month were achieved.
[0096]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0097]
[Comparative Example 4]
Cyclopentane foamed on m-tolylenediamine-based polyol A25 parts, polyol B35 parts, polyol C20 parts, polyol D10 parts and polyol F5 parts added with propylene oxide as shown in Table 1 14 parts of agent, 1.0 part of water and 1.2 parts of tetramethylhexamethylenediamine and 0.5 part of pentamethyldiethylenetriamine as reaction catalyst, 0.5 part of tris (3-dimethylaminopropylene) hexahydro-S-triazine, As a foam stabilizer, 1.8 parts of organic silicone B-8462 was blended. Further, 140 parts of diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0098]
First, the polyol and isocyanate are stirred and injected into a 600 × 400 × 75 mmt aluminum mold adjusted to 40 ° C., and the packing ratio of 115% and 125% of the overpack is obtained. Using the foamed molded product, the amount of swelling of the rigid polyurethane foam obtained by removing the mold after 5 minutes from the mold was measured.
[0099]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding increases to 4.8 mm at a pack rate of 115% and 5.7 mm at a pack rate of 125%.
[0100]
Next, after setting the outer box iron plate and the inner box of the refrigerator and freezer to the foaming jig of urethane foam in the same manner as in Example 1, the liquid temperature of the polyol and isocyanate was set to 20 ° C., the jig temperature. Is set to 40 ° C., and the rigid polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body with an injection volume of about 200 liters, and foam filling was performed at a pack rate of 110% to produce a heat insulating box body for a refrigerator and a freezer. A thermal insulation foam sample is collected from the bottom center of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, high temperature dimensional change rate are evaluated, and the heat insulation box is left at low temperature. A test was performed (−10 ° C./48 hours), and the difference in strain amount before and after the strain test of the outer case front iron plate and the maximum strain amount after the test were also evaluated.
[0101]
These results are also shown in Table 1. From Table 1, the core layer density is 35.5 kg / m 3, the thermal conductivity is as high as 18.4 mW / m · K, the compressive strength is also as low as 0.11 MPa, the low-temperature dimensional change rate is −1.8%, and the high temperature The dimensional change rate is 1.9%, indicating a large change.
[0102]
Furthermore, as a result of conducting a low-temperature standing test of the heat insulation box of the refrigerator and freezer, the difference in strain amount before and after the strain test of the outer door front iron plate is 0.19 mm and the maximum strain amount after the test is as large as 0.58 mm. Distortion deformation occurred in the outer door iron plate of the box.
[0103]
Example 6
Table 1 Polyol A 40 parts, Polyol B 23 parts, Polyol C 15 parts, Polyol D 5 parts, Polyol E 15 parts and Polyol F 2 parts 15 parts cyclopentane blowing agent, water 1 .4 parts and 1.5 parts of tetramethylhexamethylenediamine as a reaction catalyst, 0.2 parts of pentamethyldiethylenetriamine, 0.4 parts of tris (3-dimethylaminopropylene) hexahydro-S-triazine, and organic silico as a foam stabilizer 2.2 parts of B-8461. Further, 135 parts of diphenylmethane diisocyanate polynucleate and prepolymer-modified tolylene diisocyanate were foamed as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0104]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 45 ° C., and the packing ratio of 115% and 125% of the overpack is obtained. Using the foamed molded product, the amount of swelling of the rigid polyurethane foam obtained by removing the mold after 5 minutes from the mold was measured.
[0105]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding can be reduced to 2.6 mm at a pack rate of 115% and 3.1 mm at a pack rate of 125% as compared with the conventional heat insulating material.
[0106]
Next, after setting the refrigerator and freezer box on a urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was 20 ° C, and the jig temperature was 45 ° C. Then, the rigid polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 115% to produce a heat insulating box body. A thermal insulation form sample was taken from the bottom center part of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated. Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0107]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 31.5 kg / m 3, the thermal conductivity is as low as 17.9 mW / m · K, the compressive strength is as high as 0.15 MPa, and the low temperature dimensional change is −1.2%. The high temperature dimensional change rate was as small as 1.3%. Further, the strain difference between before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.08 mm, and the maximum strain after the test was as small as 0.27 mm.
[0108]
Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 3%. As a result, energy savings of about 1 Kwh / month were achieved.
[0109]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0110]
Example 7
Table 1 Polyol A 40 parts, Polyol B 20 parts, Polyol C 20 parts, Polyol D 10 parts and Polyol E 10 parts 16 parts cyclopentane blowing agent, 1.5 parts water and reaction catalyst Tetramethylhexamethylenediamine 1.5 parts, pentamethyldiethylenetriamine 0.3 parts, tris (3-dimethylaminopropylene) hexahydro-S-triazine 0.5 parts, and organic silicone B-8461 as a foam stabilizer. 2.2 parts were blended. Further, 140 parts of diphenylmethane diisocyanate polynuclear substance and prepolymer-modified tolylene diisocyanate were foamed as isocyanate. The liquid temperature of the polyol and isocyanate at that time was adjusted to 20 ° C.
[0111]
First, the polyol and isocyanate are stirred and poured into a 600 × 400 × 75 mmt aluminum mold adjusted to 45 ° C., and the packing ratio of 115% and 125% of the overpack is obtained. Using the foamed molded product, the amount of swelling of the rigid polyurethane foam obtained by removing the mold after 5 minutes from the mold was measured.
[0112]
The results are shown in Table 1. From Table 1, it can be seen that the amount of swelling after 5 minutes of demolding can be reduced to 2.3 mm at a pack rate of 115% and 2.8 mm at a pack rate of 125%, compared to a conventional heat insulating material.
[0113]
Next, after setting the refrigerator and freezer box on a urethane foam foaming jig as in Example 1, the liquid temperature of the polyol and isocyanate was 20 ° C, and the jig temperature was 45 ° C. Then, the rigid polyurethane foam is foam-filled in the voids. At that time, a zero pack was set in a box body having an injection volume of about 200 liters, and then foam filling was performed at a pack rate of 110% to produce a heat insulating box body. A thermal insulation form sample was taken from the bottom center part of the heat insulation box, and the core layer density, thermal conductivity, compressive strength, low temperature dimensional change rate, and high temperature dimensional change rate were evaluated. Furthermore, a low-temperature standing test (−10 ° C./48 hours) of the heat insulation box was performed, and the difference in strain amount before and after the strain test of the outer box surface iron plate and the maximum strain amount after the test were also evaluated.
[0114]
These results are also shown in Table 1. From Table 1, the core layer density is as low as 32.9 kg / m3, the thermal conductivity is as low as 17.8 mW / mK, the compressive strength is as high as 0.14 MPa, and the low temperature dimensional change rate is -1.4%. It can be seen that the high temperature dimensional change rate is as small as 1.1%.
[0115]
Further, the difference in strain amount before and after the strain test of the outer box surface iron plate of the heat insulation box was 0.07 mm, and the maximum strain amount after the test was as small as 0.29 mm. Furthermore, as a result of measuring by incorporating a refrigeration cycle component (compressor / condenser / evaporator) into a refrigerator and freezer with a heat insulation box filled with rigid polyurethane foam, the amount of heat leakage was reduced by 3%. As a result, energy savings of about 1 Kwh / month were achieved.
[0116]
For this reason, the rigid polyurethane foam according to the present example is a rigid polyurethane foam that has a small amount of swelling when filled, has a low density, and has excellent thermal conductivity reduction, compressive strength, and dimensional stability. Moreover, by filling the rigid polyurethane foam according to the present embodiment as a heat insulating material for a refrigerator, the amount of heat leakage can be reduced and the power consumption can be reduced. Furthermore, the filling amount of the heat insulating material is reduced, and the cost of the refrigerator can be reduced. Further, even when left at low temperature, the distortion of the refrigerator is reduced, and the appearance quality of the refrigerator is excellent.
[0117]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the distortion deformation of the surface is prevented and the refrigerator excellent in external appearance quality can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a heat insulating material in which urethane is filled in a heat insulating box and a heat insulating door of a refrigerator and a freezer.
FIG. 2 is a schematic diagram in which urethane is filled into a heat-insulating box by four-point foaming, and a schematic diagram of sampling of a urethane measurement sample.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Refrigerator main body, 2 ... Inner box, 3 ... Cold room, 4 ... Vegetable room, 5 ... Freezer room, 6 ... Cold room door, 7 ... Vegetable room door, 8 ... Upper freezer door, 9 ... Lower freezer door DESCRIPTION OF SYMBOLS 10 ... Urethane heat insulating material, 11 ... Urethane injection head, 12 ... Flow of urethane, 13 ... Urethane inlet, 14 ... Sample collection position

Claims (4)

In a refrigerator provided with a heat insulating material filled with a rigid polyurethane foam using at least a polyol, an aromatic isocyanate and a mixed foaming agent of cyclopentane and water as a blowing agent in a space between the outer box and the inner box,
As a polyol component, it contains at least 3 components of a mixture obtained by adding an initiator composed of m-tolylenediamine and o-tolylenediamine with ethylene oxide and / or propylene oxide, and an initiator composed of o-tolylenediamine is m-triylene. refrigerators rigid polyurethane foams used in smaller amounts than the initiator consisting of diamine comprises a cross heat material filled.   Polyether containing 90% or more of a mixture in which an initiator composed of m-tolylenediamine, o-tolylenediamine, bisphenol A, and triethanolamine is added with ethylene oxide and / or propylene oxide as the polyol component of the rigid polyurethane foam. A density of a core layer heat insulating material having a thickness of about 20 to 25 mm from a plane portion at least 500 mm or more away from a urethane injection port is 29 to 33 kg / m 3, and a thermal conductivity is 17.5 to 18 at an average temperature of 10 ° C. The refrigerator of Claim 1 provided with the said heat insulating material which has 0.0 mW / m * K.   The aromatic isocyanate component of the rigid polyurethane foam uses diphenylmethane diisocyanate polynuclear mixture of prepolymer-modified tolylene diisocyanate, and further, 1.2 to 1.6 parts by weight of water and 14 to 14 parts by weight per 100 parts by weight of polyol. The refrigerator according to claim 2, comprising the heat insulating material obtained by reacting in a mixed foaming agent in which 18 parts by weight of cyclopentane is combined.   The polyol component of the rigid polyurethane foam is 45 to 55 parts by weight of a polyol having an OH number of 400 to 500 obtained by adding propylene oxide and ethylene oxide and propylene oxide to m-tolylenediamine, and propylene oxide to o-tolylenediamine. 10 to 20 parts by weight of a polyol having an OH number of 450 to 500 obtained by addition with ethylene oxide and 10 to 20 parts by weight of a polyol having an OH number of 350 to 450 obtained by adding propylene oxide to triethanolamine, bisphenol A 10 to 20 parts by weight of a polyol having an OH number of 250 to 300 obtained by adding propylene oxide to diethanolamine, 3 to 8 parts by weight of a polyol having an OH number of 450 to 480 obtained by adding propylene oxide to diethanolamine, trimethylo Trimethylolpropane OH number 1256 and consists of a mixture of 2 to 5 parts by weight, the refrigerator according to claim 3, wherein the average OH value of the polyol with the insulation rigid polyurethane foam is filled is 400 to 450.

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