JP3739481B2 - Polypropylene resin material and method for producing the same - Google Patents

Description

【００３６】
［γ線照射ポリプロピレン系樹脂（Ａ2成分）の作製］
（γＰＰ−１）
上記のＰＰ−１（ＭＦＲ＝０.５g/10分、ＩＰ＝０.９９４：本文中の（式２）を満足する）をコーガアイソトープ（株）のγ線照射装置（自動照射台）を使用し、活性酸素濃度が５.６％の雰囲気下で５０ｋＧｙ（最低線量４７.５ｋＧｙ、最高線量５２.６ｋＧｙ、パースペックス線計で測定）照射した。照射後のＭＦＲは５.６g/10分であった。過酸化ラジカルが存在することをＥＳＲ測定で確認した。
（γＰＰ−２）
上記のＰＰ−２（ＭＦＲ＝０.５g/10分、ＩＰ＝０.９４１：本文中の（式２）を満足しない）をコーガアイソトープ（株）のγ線照射装置（自動照射台）を使用し、活性酸素濃度４.８％の窒素雰囲気下で５０ｋＧｙ（最低線量４７.５ｋＧｙ、最高線量５２.６ｋＧｙ、パースペックス線計で測定）照射した。照射後のＭＦＲは１７.０g/10分であった。過酸化ラジカルが存在することをＥＳＲで確認した。
【００３７】
【表２】

【００３８】
［β晶分率の温度依存性］
（Ａ1）成分として、上記ＰＰ−１を９０重量％、（Ａ2）成分として上記γＰＰ−１を１０重量％のポリプロピレン系樹脂組成物の１００重量部に対し、ジ−ｔ−ブチル−ｐ−クレゾール（ＢＨＴ）を０.０８重量部、ペンタエリスリチルテトラキス［３−（３，５−ジ−ｔ−ブチル−４−ブチルヒドロキシフェニル）プロピオネート］（「イルガノックス１０１０」日本チバガイギー社製）を０.０５重量部、ステアリン酸カルシウム（「カルシウムステアレート」）を０.１重量部を混合し、２３０℃でペレット化した。
これを高圧プレス機（庄司鉄工（株）製）を用い、プレス温度を２３０℃で予熱５分間、脱気３０秒行なった後、６０Ｋｇ／cm²で５分間放置後、特定の冷却温度（３０℃〜１００℃）で１０分間結晶化し、厚み０.５ｍｍｔで１０ｃｍ×１０ｃｍのプレスシートを作製した。得られたプレスシートのβ晶分率の温度依存性を図３に「−○−」で示した。
比較として、次の２種のポリプロピレン系樹脂組成物からなるペレットについても、同様の評価を行い、図３に示した。
１００重量部のＰＰ一１に対し、ＢＨＴ０.０８重量部、イルガノックス１０１０を０.０５重量部、カルシウムステアレート０.１重量部を加え混合し、２軸押出機（「ＫＴＸ−３７」神戸製鋼所製）を使用して２３０℃で溶融混練りしてペレットを作製、同様の評価を実施した。図３中に「−●−」で示す。
さらに、１００重量部のＰＰ一１に対し、ＢＨＴ０.０８重量部、イルガノックス１０１０を０.０５重量部、カルシウムステアレートを０.１重量部、β晶核剤（「エヌシェスターＮＵ−１００」新日本理化（株）製）を加え、２軸押出機（「ＫＴＸ−３７」）を使用して２３０℃で溶融混練りしてペレットを作製し、同様の評価を実施した。図３中に「−□−」で示す。
図３から明らかなように、本発明でのポリプロピレン系樹脂組成物（−○−）は、比較例のポリプロピレン系樹脂組成物と異なリ、むしろ、低温でβ晶が多く生成されるという特徴を有している。
【００３９】
［ポリプロピレン系樹脂材料の作製］
実施例１〜１１、比較例２、３、６、７〜１５、１９
表１及び２に種類及び配合量が示されている（Ａ１）成分のポリプロピレン系樹脂と、（Ａ2）成分のγ線照射したポリプロピレン系樹脂ならびにＢＨＴを０.０５重量部、イルガノックス１０１０を０.１重量％およびカルシウムステアレートを０.１重量部配合し、スーパーミキサー（「ＳＭＶ２０型」川田製作所社製）を用いて混合し、二軸押出機（「ＡＳ３０型」中谷機械社製）を用い、温度２３０℃（ＰＰ−３を用いたものは２００℃）でペレット化した。押出機のスクリュー回転数は１００ｒｐｍであった。
【００４０】
実施例１および２（熱処理によるβ晶からα晶への結晶転換を利用した例）、比較例１〜３
（実施例１）
（Ａ1）成分としてＰＰ−１を９７重量％、（Ａ2）成分としてγＰＰ−１を３重量％の樹脂１００重量部に対し、ＢＨＴを０.０５重量部、イルガノックス１０１０を０.１重量部およびカルシウムステアレートを０.１重量部配合したものを用いて上記の方法によりペレット状のポリプロピレン系樹脂組成物を得た。このペレットを用いて上記β晶分率測定用の試験片を作成した（得られたプレス試験片のβ晶分率は４３％であった）。この試験片を、窒素雰囲気下、１５０℃に温調したオーブン中で２時間加熱した後、室温に冷却し、ポリプロピレン系樹脂材料（β晶分率は０％であった）を得た。状態調節の後、この試験片の物性を測定した。結果を表３に示した。
【００４１】
（実施例２）
（Ａ1）成分としてＰＰ−１を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、実施例１と同様に行った。熱処理前のプレス試験片のβ晶分率は４７％であった。
（比較例１）
１００重量部のＰＰ−１に対し、市販の安定剤であるＢＨＴ０.０８重量部、イルガノックス１０１０を０.０５重量部、カルシウムステアレート０.１重量部を加え、２軸押出機（「ＫＴＸ−３７」）を使用して２３０℃で溶融混練りし、ペレット状のポリプロピレン系樹脂組成物を作製した。このペレットを用いて上記β晶分率測定用の試験片を作成した（得られたプレス試験片のβ晶分率は０％であった）。この試験片を窒素雰囲気下、１５０℃に温調したオーブン中で２時間加熱した後、室温に冷却した。試験片の状態調節の後、物性を測定した。結果を表３に示した。
（比較例２）
（Ａ1）成分としてＰＰ−２（ＭＦＲ＝０.６g/10分、ＩＰ＝０.９４１）９０重量％、（Ａ2）成分として上記のγＰＰ−２を１０重量％用いた以外は、実施例１と同様に行った。熱処理前のプレス試験片のβ晶分率は２％であった。
【００４２】
（比較例３）
実施例２の熱処理前の試験片（β晶分率＝４７％）の物性を測定した。結果を表３に示した。
【表３】

実施例３〜９（α晶核剤によるβ晶からα晶への結晶転換を利用した例）、比較例４〜１５
（実施例３）
（Ａ1）成分としてＰＰ−１を９９重量％、（Ａ2）成分としてγＰＰ−１を１重量％用いて上記の方法によりペレット状のポリプロピレン系樹脂組成物を得た。このペレットより上記β晶分率測定用の試験片を作成した。
得られた試験片（β晶分率２６％）を裁断したもの１００重量部に対して、α晶の核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りし、ポリプロピレン系樹脂材料を得た。得られたポリプロピレン系樹脂材料（β晶分率０％）を用いて試験片を作製し、物性を測定した。結果を表４に示した。
【００４３】
（実施例４）
（Ａ1）成分としてＰＰ−１を９８重量％、（Ａ2）成分としてγＰＰ−１を２重量％用いた以外は、実施例３と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は３９％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表４に示した。
（実施例５）
（Ａ1）成分としてＰＰ−１を９７重量％、（Ａ2）成分としてγＰＰ−１を３重量％用いた以外は、実施例３と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は４２％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表４に示した。
【００４４】
（実施例６）
（Ａ1）成分としてＰＰ−１を９５重量％、（Ａ2）成分としてγＰＰ−１を５重量％用いた以外は、実施例３と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は４３％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表４に示した。
（実施例７）
（Ａ1）成分としてＰＰ−１を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、実施例３と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は４７％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表５に示した。
【００４５】
（実施例８）
（Ａ1）成分としてＰＰ−１を８５重量％、（Ａ2）成分としてγＰＰ−１を１５重量％用いた以外は、実施例３と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は４７％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表５に示した。
（実施例９）
（Ａ1）成分としてＰＰ−３を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、実施例３（但し、２００℃で溶融混練）と同様に行った。ポリプロピレン系樹脂組成物のβ晶分率は１７％、α晶の核剤であるナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（「ＮＡ１１」）を０.４重量部添加して作製したポリプロピレン系樹脂材料のβ晶分率は０％であった。結果を表５に示した。
【００４６】
【表４】

【００４７】
【表５】

【００４８】
（比較例４）
１００重量部のＰＰ−１に対し、市販の安定剤であるＢＨＴ０.０８重量部、イルガノックス１０１０を０.０５重量部、カルシウムステアレート０.１重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りし、ペレット状のポリプロピレンを作製した。このペレット（β晶分率０％）１００重量部に対し、α晶の核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りし、ポリプロピレン系樹脂材料を作製した。これを用いて試験片を作製し、物性を測定した。結果を表６に示した。
（比較例５）
ＰＰ−１の代わりにＰＰ−３を用いた以外は、比較例４と同様（但し、２００℃で溶融混練）に行った。ポリプロピレン系樹脂組成物にあたるペレットのβ晶分率は０％であった。ポリプロピレン系樹脂材料を用いて試験片を作製し、物性を測定した。結果を表６に示した。
【００４９】
（比較例６）
（Ａ1）成分としてＰＰ−１を９９重量％、（Ａ2）成分としてγＰＰ−１を１重量％用いて上記の方法により、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りした後、溶融した状態で、α晶の核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、ペレット状のポリプロピレン系樹脂材料を作製した。これを用いて試験片を作製し、物性を測定した。結果を表６に示した。
（比較例７）
（Ａ1）成分としてＰＰ−１を９８重量％、（Ａ2）成分としてγＰＰ−１を２重量％用いた以外は、比較例６と同様に行った。結果を表６に示す。
（比較例８）
（Ａ1）成分としてＰＰ−１を９７重量％、（Ａ2）成分としてγＰＰ−１を３重量％用いた以外は、比較例６と同様に行った。結果を表７に示す。
【００５０】
（比較例９）
（Ａ1）成分としてＰＰ−１を９５重量％、（Ａ2）成分としてγＰＰ−１を５重量％用いた以外は、比較例６と同様に行った。結果を表７に示す。
（比較例１０）
（Ａ1）成分としてＰＰ−１を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、比較例６と同様に行った。結果を表７に示す。
（比較例１１）
（Ａ1）成分としてＰＰ−１を８５重量％、（Ａ2）成分としてγＰＰ−１を１５重量％用いた以外は、比較例６と同様に行った。結果を表７に示す。
（比較例１２）
（Ａ1）成分としてＰＰ−３を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、比較例６（但し、２００℃で溶融混練）と同様に行った。結果を表８に示す。
（比較例１３）
（Ａ1）成分としてＰＰ−２を９０重量％、（Ａ2）成分としてγＰＰ−２を１０重量％用いて上記の方法によりペレット状のポリプロピレン系樹脂組成物を得た。このペレットより、上記のβ晶分率測定用の試験片を作製した。得られた試験片（β晶分率２％）を裁断したもの１００重量部に対して、α晶の核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りし、ポリプロピレン系樹脂材料を得た。得られたポリプロピレン系樹脂材料を用いて試験片を作製し、物性を測定した。結果を表８に示した。
【００５１】
（比較例１４）
（Ａ1）成分としてＰＰ−１を９７重量％、（Ａ2）成分としてγＰＰ−１を３重量％用いて上記の方法によりペレット状のポリプロピレン系樹脂組成物を得た。このペレットより、上述した［β晶分率の温度依存性］の欄に示した方法に基づいて、厚み０．５mmｔで１０cm×１０cmのプレスシートをプレス温度１３５℃で作製した。得られたプレスシート（β晶分率０％）を裁断した一次成形物１００重量部に対して、α晶核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２３０℃で溶融混練りし、ポリプロピレン系樹脂材料を得た。得られた樹脂材料を用いて試験片を作製し、物性を測定した。結果を表８に示した。
（比較例１５）
（Ａ1）成分としてＰＰ−１を９０重量％、（Ａ2）成分としてγＰＰ−１を１０重量％用いた以外は、比較例１４と同様に行った。得られたポリプロピレン系樹脂組成物のシート（一次成形物）のβ晶分率は０％であった。結果を表８に示した。
【００５２】
（比較例１６）
１００重量部のＰＰ−３に対し、市販の安定剤であるＢＨＴ０.０８重量部、イルガノックス１０１０を０.０５重量部、カルシウムステアレート０.１重量部、β晶の核剤として新日本理化社製「エヌジェスターＮＵ−１００」を０.２重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２００℃で溶融混練りし、ペレットを作製した。このペレットより、上記のβ晶分率測定用のプレスシート（但し、１００℃で結晶化）を作製した。
得られたプレスシート（β晶分率４７％）を裁断したもの１００重量部に対して、α晶核剤としてナトリウム−２、２'−メチレン−ビス（４、６−ジ−ｔ−ブチルフェニル）フォスフェート（旭電化社製「ＮＡ１１」）を０.４重量部を加え、２軸押出機（ＫＴＸ−３７）を使用して２００℃で溶融混練りし、ぺレット状のポリプロピレン系樹脂材料を得た。この樹脂材料のβ晶分率は６％であった。この樹脂材料を用いて試験片を作製し、物性を測定した。結果を表９に示した。
【００５３】
【表６】

＊：β晶含有ペレットを経ずにＰＰ系樹脂材料を製造したもの。
【００５４】
【表７】

＊：β晶含有ペレットを経ずにＰＰ系樹脂材料を製造したもの。
【００５５】
【表８】

＊：β晶含有ペレットを経ずにＰＰ系樹脂材料を製造したもの。
＊＊：α晶核剤添加前の一次成形体（１３０℃結晶化）のβ晶分率は０％。
【００５６】
【表９】

なお、剛性、耐熱性は樹脂のＭＦＲにも大きく依存する。実施例１〜８及び比較例１〜４、６〜１１、１３〜１５が低ＭＦＲの場合、実施例９及び比較例５、１２、１６が高ＭＦＲの場合に相当する。表３〜９から同程度のＭＦＲでは、実施例のポリプロピレン系樹脂材料であると、比較例のポリプロピレン系樹脂材料よりも剛性、耐熱性に優れることがわかる。
【００５７】
実施例１０、１１（α晶核剤によるβ晶からα晶への結晶転換を利用した例）、比較例１９
（実施例１０）
（Ａ1）成分としてＰＰ−１を９５重量％、（Ａ2）成分としてγＰＰ−１を５重量％用い、α晶核剤として１，３，２，４−ビス（ｐ−メチルベンジリデン）ソルビトール（新日本理化社製「ゲルオールＭＤ−Ｒ」）を０.３重量％用いた以外は実施例３と同様に行なった。結果を表１０に示した。
（実施例１１）
（Ａ1）成分としてＰＰ−４を９５重量％用い、（Ａ2）成分としてγＰＰ−１を５重量％用い、α晶核剤として「ゲルオールＭＤ−Ｒ」を０.２５重量％用いた以外は実施例３と同様に行った。結果を表１０に示した。
（比較例１９）
ＰＰ−１を９５重量％と、γＰＰ−１を５重量％用い、α晶核剤として「ゲルオールＭＤ−Ｒ」を０.３重量％用いた以外は比較例９と同様に行った。結果を表１０に示す。
【００５８】
【表１０】

＊：β晶含有ペレットを経ずにＰＰ系樹脂材料を製造したもの。
【００５９】
（比較例１７）
１００重量部のＰＰ−１を用い、核剤を用いない以外は比較例４と同様に行った。結果を表１１に示した。
（比較例１８）
１００重量部のＰＰ−１を用い、α晶核剤として「ゲルオールＭＤ−Ｒ」を０.３重量％用いた以外は、比較例４と同様の方法を行なった。結果を表１１に示した。
（比較例２０）
１００重量部のＰＰ−４を用い、核剤を用いない以外は比較例４と同様に行った。結果を表１１に示した。
（比較例２１）
１００重量部のＰＰ−４を用い、α晶核剤として「ゲルオールＭＤ−Ｒ」を０.２５重量％用いた以外は比較例４と同様に行った。結果を表１１に示した。
【００６０】
【表１１】

【００６１】
【発明の効果】
本発明のポリプロピレン系樹脂材料は、従来のものと比較して、剛性、耐熱性、透明性が非常に優れている。従って、特に、射出成形、中空成形、シート成形、真空成形等に用いられる構造材料用の素材として、エンジニアリングプラスチックの代替として用いるのに好適である。
【図面の簡単な説明】
【図１】示差走査熱量測定法による結晶化時の発熱量曲線を示すグラフである。
【図２】示差走査熱量測定法による融解時の吸熱量曲線を示すグラフである。
【図３】β晶分率のプレス温度依存性を示すグラフである。
【図４】ポリプロピレンのＥＳＲのスペクトルである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polypropylene resin material excellent in rigidity, heat resistance and transparency and a method for producing the same.
[0002]
[Prior art]
Isotactic crystalline polypropylene (hereinafter abbreviated as PP) is relatively inexpensive and excellent in rigidity, surface gloss, and heat resistance, but under normal crystallization conditions, the crystallinity is sufficiently increased. Therefore, the rigidity and heat resistance are not sufficient to replace so-called engineering plastics that are expensive and difficult to recycle.
Therefore, many attempts have been made to use fillers such as talc and glass fiber for the purpose of improving the rigidity and heat resistance of PP-based materials. Therefore, a material that is limited in quantity and satisfactory as a material has not been obtained.
In addition, for the purpose of substituting for PET and the like, studies using comonomer copolymerization, a transparent nucleating agent, and the like have been made, but nothing satisfying the balance between transparency and rigidity has yet been obtained.
[0003]
[Problems to be solved by the invention]
By the way, the crystal part of PP has many crystal systems such as α crystal, β crystal, γ crystal, and smectic crystal, and the amount of PP varies depending on the molecular structure of PP, the presence of crystal nucleating agent, and crystallization conditions. To do. Of these, the α crystal is known to be the most stable and excellent in heat resistance among PP crystals.
Therefore, in order to improve the rigidity and heat resistance of PP industrially, an α-crystal nucleating agent is used, but sufficient rigidity, heat resistance and the like are not fully exhibited.
The present invention has been made to solve the above-described problems, and provides a polypropylene resin material having high rigidity, heat resistance, and transparency, and a method for producing the same.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 has a β crystal fraction of 5% or more when measured using a press-molded product that is isothermally crystallized at 30 ° C.
When the β crystal content at the time of isothermal crystallization at 30 ° C. and 100 ° C. is β (30) and β (100), (Equation 1) is satisfied,
(Formula 1) β (30)> β (100)
And it is a manufacturing method of the polypropylene resin material characterized by converting at least a part of β crystals of a polypropylene resin composition having a melt flow rate of 0.05 to 1000 g / 10 min into α crystals.
The invention described in claim 2 relates to a polypropylene resin having physical properties of the following (a) and (b): 70 to 99.5% by weight of a polypropylene resin having a melt flow rate of 0.05 to 1000 g / 10 min. Polypropylene resin composition having a β crystal fraction of 5% or more obtained by melting and kneading 0.5 to 30% by weight of a resin that has been treated to generate peroxide radicals in a state where peroxide radicals are not deactivated before melting. A method for producing a polypropylene resin material, wherein at least a part of β crystals of a product is converted to α crystals.
(A) Melt flow rate is 5g / 10min or less
(B) The isotactic pentad fraction (abbreviated as IP) and the melt flow rate (abbreviated as MFR) are in the relationship of (Formula 2).
(Formula 2) IP> 0.0428 × log (MFR) +0.97
[0005]
Here, it is desirable to convert the β crystal fraction to 2% or less by converting at least part of the β crystal into α crystal.
The conversion is preferably performed by adding an α crystal nucleating agent.
Furthermore, the polypropylene resin composition preferably has a propylene chain isotactic pentad fraction of at least 0.970.
Further, the addition amount of the α crystal nucleating agent is desirably 0.01 to 30 parts by weight with respect to 100 parts by weight of the polypropylene resin composition.
The α crystal nucleating agent is preferably an alkali metal salt.
Further, as the alkali metal salt, a phosphate alkali metal salt is suitable.
Furthermore, sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate is preferred as the alkali metal salt.
[0006]
The polypropylene resin material of the present invention is obtained by these production methods.
At this time, the polypropylene resin material is
Melt flow rate (MFR) is 0.05 to 1000 g / 10 min,
It is desirable that the MFR and the ratio of the endothermic amount ΔHm at the time of melting and the exothermic amount ΔHc at the time of crystallization measured by the differential scanning calorimetry method satisfy (Equation 3).
(Expression 3) ΔHm / ΔHc> 0.001515 log (MFR) +1.032
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention seeks to obtain a polypropylene resin material that is extremely excellent in rigidity, heat resistance, and transparency by controlling the crystal structure of the polypropylene resin.
While α-crystal PP is excellent in rigidity and heat resistance, β-crystal PP has a lower melting point than α-crystal, and the larger the β-crystal fraction, the smaller the energy at the time of resin melt molding and the better the moldability.
Therefore, taking advantage of the characteristics of each of the α crystal and β crystal, to improve the moldability by containing a lot of β crystal before molding such as injection molding, convert the β crystal to α crystal at the time of molding or after molding, Increase the rigidity and heat resistance of the molded body.
Once the β crystal is formed with the β crystal nucleating agent and then recrystallized into the α crystal by the Self-Seeding method, nucleation during crystallization is promoted more than when the same α crystal is started. (See: Lotz et al. (Fillon et.al., J. Polym. Sci. B, 31, 1407 (1993))). Therefore, in the present invention, by increasing the number of nuclei, the crystal is refined to improve transparency.
By the way, the β crystal transforms into an α crystal by stretching. However, since the β crystal is more unstable than the α crystal, stretching from this state is advantageous in terms of energy.
As a practical method for forming a large amount of β crystals, methods using a β crystal nucleating agent are known (Japanese Patent Laid-Open Nos. 6-1892 and 6-107875). The presence of the nucleating agent causes problems such as coloring, and even when the α-crystal nucleating agent is used, there is a possibility that the conversion from the β-crystal to the α-crystal may be hindered. Can be avoided.
[0008]
In the present invention, a polypropylene resin material is obtained by converting β crystals of a specific polypropylene resin composition containing 5% or more of β crystals into α crystals.
In the present invention, the polypropylene resin composition which is the base of the polypropylene resin material has a β crystal fraction of 5% or more. More preferably, it is 15% or more, more preferably 20% or more, and still more preferably 30% or more. By having 5% or more of β crystals, the energy during melt molding is small and the moldability is excellent. On the other hand, if it is less than 5%, even if all the β crystals are converted to α crystals, the amount of crystal conversion from β crystals to α crystals is small, and a sufficient physical property improving effect does not appear.
Here, the β crystal fraction refers to the ratio of β crystals to the entire crystal part of the polypropylene resin composition.
Unless otherwise specified, the β crystal fraction is measured for a press-formed product (press sheet) crystallized isothermally at 30 ° C. The press-molded product is 0.5mmt, and it is deaerated after preheating at 230 ° C for 5 minutes using a special mold of 10cm x 10cm, 60kg / cm ² Pressurize for 5 minutes and then use a cooling press at 30 ° C. for 10 minutes to 60 kg / cm ² And pressurize to make. In order to obtain the β crystal fraction, first, as a radiation source, using a CuK line monochromated with a Ni filter of an X-ray generator (Ru-Denki RU-200), a scattering angle under conditions of 50 kV and 150 mA. The X-ray profile is measured in the range of (2θ) of 10 to 30 °. The β crystal fraction is calculated according to the method described in A. Turner Jones et al; Macromol. Chem. 75, 134 (1964) after correcting the air scattering to the obtained scattering profile.
That is, after subtracting the scattering of the amorphous part, the heights of the peaks corresponding to the scattering of the (110), (040), (130) of the α crystal and the (300) crystal part of the β crystal are set to h [ [alpha]] (110), h [[alpha]] (040), h [[alpha]] (130), h [[beta]] (300), and [beta] crystal fraction (k) was calculated from the following equation.
k = h [β] (300) / (h [α] (110) + h [α] (040) + h [α] (130) + h [β] (300))
[0009]
In the invention described in claim 1, when the polypropylene resin composition is β (30) and β (100) when the β crystal content is isothermally crystallized (press-molded) at 30 ° C. and 100 ° C., respectively, (Equation 1) is satisfied.
(Formula 1) β (30)> β (100)
That is, the press-molded product is 0.5 mmt, and is degassed after preheating at 230 ° C. for 5 minutes using a special mold of 10 cm × 10 cm, 60 kg / cm ² And pressurizing for 5 minutes at 60 kg / cm for 10 minutes each using a cooling press at 30 ° C and 100 ° C. ² When the β crystal fraction is measured for the two types of molded articles produced by pressurizing in step 3, the β crystal content at 30 ° C. needs to be larger than the β crystal content at 100 ° C.
Satisfying this (Formula 1) indicates that forming at a low temperature produces higher β crystals, while forming at a low temperature a primary molded product having a high β crystal fraction, This means that β crystals are difficult to form at high temperatures. This is a feature not found in conventional polypropylene resins. Although details are not clear, as a result, the heat treatment and stretching of the β-crystal of the temporary molded product obtained from this, and the conversion to α-crystal by melting and kneading the nucleating agent (performed at a relatively high temperature) are further promoted. It is thought that the improvement effect of the physical property of a molded object leads to.
[0010]
The invention according to claim 2 includes a polypropylene resin having an MFR of 0.05 to 1000 g / 10 min (referred to as component (A1)) and a polypropylene resin having the following physical properties (a) and (b). A resin (referred to as component (A2)) that has been subjected to a treatment for generating an oxidation radical is melt-kneaded in a state that does not deactivate the peroxide radical before melting.
The polypropylene resin used in the component (A1) and component (A2) in the present invention has a high stereoregularity, and the catalyst system for obtaining this is not particularly limited. However, when a Ziegler catalyst is used, a particularly high It is preferred to use a specific magnesium supported catalyst system.
A method for generating a peroxide radical is not particularly limited, but ionizing ray irradiation, particularly γ ray irradiation is preferable.
[0011]
The polypropylene resin of the component (A1) in the present invention is mainly composed of homopolypropylene or propylene, and a small amount (10% by weight or less of the whole) of α-olefin such as ethylene, butene-1, pentene-1, and the like. Or a block copolymer of propylene and an α-olefin such as ethylene or butene-1.
In the block copolymer, it is preferable that the proportion of the copolymer rubber component of propylene and other α-olefin in the copolymer is 5 to 80% by weight, and the propylene content in the rubber component Is preferably 30 to 70% by weight. These may be used alone or in combination of two or more.
The polypropylene resin as the component (A1) has an MFR of 0.05 to 1000 g / 10 minutes, preferably 0.1 to 500 g / 10 minutes. If the MFR is 0.05 g / 10 min or less, the moldability is poor. On the other hand, if it exceeds 1000 g / 10 min, a β crystal fraction of 5% or more cannot be obtained.
The stereoregularity of the polypropylene chain of the component (A1) of the present invention is not particularly limited, but a more stereoregular polypropylene resin is more preferable.
[0012]
One of the methods for obtaining a polypropylene resin treated with the generation of peroxide radicals as the component (A2) of the present invention is a method of subjecting a polypropylene resin having the following physical properties (a) and (b) to γ-ray treatment. It is done.
(A) Melt flow rate (MFR) 5 g / 10 min or less
(B) Isotactic pendant fraction (IP) and MFR have the relationship of (Formula 2)
(Formula 2) IP> 0.0428 × log (MFR) +0.97
The reason why the MFR of the polypropylene resin used for the component (A2) is 5 g / 10 min or less is that when the MFR exceeds 5 g / 10 min, a β crystal fraction of 5% or more cannot be obtained.
If the relationship between IP and MFR does not satisfy the above formula, a β crystal fraction of 5% or more cannot be obtained.
IP is an isotope nuclear magnetic resonance ( ¹³ This is the isotactic fraction of the Pendad unit in the polypropylene molecular chain measured using C-NMR), and its measurement method is described in A. Zambelli; Macromolecules, 6, 925 (1973), 8,687, (1975) and 13,267 (1980). That is, ¹³ This is the isotactic fraction of pentad units in a polypropylene molecular chain measured using C-NMR, and means the fraction of propylene monomer units in which five propylene monomer units are isotactically bonded in succession. .
[0013]
As a method for obtaining a polypropylene-based resin satisfying the above (formula 2), for example, as a catalyst, a solid catalyst containing a magnesium compound, a titanium compound, a halogen-containing compound and an electron donating compound as essential components is further represented by the general formula TiXa · Yb ( In the formula, X represents a Cl, Br, or I halogen atom, Y represents an electron donating compound such as diisobutyl phthalate or diisobutyl maleate, a represents an integer of 3 or 4, and b represents an integer of 3 or less.) And a highly stereoregular polypropylene resin polymerized using a polymerization catalyst obtained by washing with a halogen-containing compound and then washing with a hydrocarbon after treatment with a titanium compound represented by formula (1).
The polypropylene resin is mainly composed of homopolypropylene or propylene, and a small amount (10% by weight or less of the total) of a random copolymer with an α-olefin such as ethylene, butene-1, pentene-1, or the aforementioned propylene and A block copolymer with an α-olefin such as ethylene or butene-1 is selected. These polypropylene resins may be used alone or in combination of two or more.
[0014]
The polypropylene resin which is the component (A2) of the present invention is obtained by subjecting polypropylene satisfying the above (a) and (b) to a treatment for generating peroxide radicals.
(A2) As a component, a polypropylene resin having an MFR of 5 g / 10 min or less is treated to generate peroxide radicals, and the (A1) component and the generated peroxide radicals are melted and mixed without being deactivated before melting. When a polypropylene resin composition is obtained, the production of the β crystal fraction of polypropylene is 5% or more. The lower the MFR and the higher the isotactic pentad fraction (IP), the higher the β crystal fraction when it is melt-mixed with the component (A1) to form a primary molded product, and the above relational expression of MFR and IP must be satisfied. Even higher β crystal fractions can be obtained. For example, when MFR = 4 g / 10 min, IP = 0.996 or more, when MFR = 3.0 g / 10 min, IP = 0.990 or more, when MFR = 2.0 g / 10 min, IP = 0.983 or more, and MFR = 1.5 g / 10 min. IP = 0.978 or more.
[0015]
The component (A2) of the present invention is preferably obtained by irradiating polypropylene polymer powder or pellets in the air or in an inert gas atmosphere containing 1% or more of active oxygen. Preferably it is 3% or more, More preferably, it is 5% or more. When the above conditions are not satisfied, a polypropylene resin composition having a β crystal content of 5% or more, which is a feature of the present invention, cannot be obtained.
The irradiation dose is 5 to 100 kGy, preferably 8 to 80 kGy, particularly 10 to 70 kGy. This is because if it is less than 5 kGy, the β crystal fraction cannot be increased. It is not necessary to make it higher than 100 kGy, and if it is 100 kGy or more, the molecular weight is cut and a gel is easily generated.
It is important that the polypropylene resin as the component (A2) has a peroxide radical after γ-ray irradiation. This is observed from ESR measurements as shown in FIG.
Note that ESR is a well-known device for detecting radicals contained in a sample. The principle of the ESR is shown in, for example, an introduction to electron spin resonance (written by M. Bersohn, JC Baird, Shigeo Fujiwara, Tokuko Watanabe, Tokyo Chemical Dojin). Has been. The interpretation of the spectrum is shown, for example, in electron spin resonance (Hiroaki Ohya, Kei Yamauchi, Kodansha Scientific).
[0016]
As shown in FIG. 4, since the peroxide radicals are deactivated when heat treatment or the like is performed, it is important that mixing with the component (A1) is performed without performing these deactivation treatments. .
The composition ratio of the component (A2) in the total amount of the polypropylene resin composition composed of the components (A1) and (A2) of the present invention is 0.5 to 30% by weight, and 1 to 20% by weight. Particularly preferred is 3 to 15% by weight. When the proportion of the component (A2) is less than 0.5% by weight, a polypropylene resin composition having a β crystal fraction of 5% or more cannot be obtained. On the other hand, if it exceeds 30% by weight, the cost increases, which is not preferable.
A method for obtaining a polypropylene resin composition comprising the component (A1) and the component (A2) in the present invention will be described.
First, the components (A1) and (A2) are melt-kneaded. Specifically, after dry blending using a mixer such as a Henschel mixer, tumbler, or ribbon mixer, melt mixing is performed using a Banbury, kneader, or extruder. As the extruder, either a single screw or a twin screw extruder may be used. The temperature for melting and mixing is generally 170 to 300 ° C, preferably 180 to 280 ° C.
[0017]
After melt-kneading, cooling is performed in a temperature range of −15 to 120 ° C. The lower the cooling temperature, the better, preferably -15 to 60 ° C, more preferably -15 to 40 ° C. The lower the cooling temperature, the higher the β crystal production rate.
At this time, it is desirable to perform cooling with as little molecular orientation as possible. Examples of the method for performing crystallization in a state with little orientation include press molding and extrusion molding. In order to cool the resin melt-kneaded by an extruder and obtain the target polypropylene resin composition, it is preferable that the extrusion speed is low so that the orientation is not as much as possible. Although a suitable extrusion speed varies depending on the type of the extruder, it is preferable to carry out at an extrusion speed at which no orientation is applied.
The polypropylene resin composition obtained by the above method has an MFR of 0.05 to 1000 g / 10 min.
[0018]
Furthermore, in order to obtain the target high rigidity, high heat resistance and high transparency polypropylene resin material, the propylene chain isotactic pentad fraction (IP) of the polypropylene resin composition is 0.00. It is desirable that it is 970 or more. Preferably, it is 0.975 or more, more preferably 0.980 or more. When the IP is 0.970 or less, a molded article having sufficient rigidity, heat resistance and transparency cannot be obtained.
The polypropylene resin composition referred to in the present invention refers to a material comprising the components (A1) and (A2), and may be in the form of pellets or any other form such as a sheet.
The polypropylene resin composition according to the present invention has various conventional additives such as antioxidants, weathering stabilizers, antistatic agents, lubricants, antifogging agents as required, as long as the β crystal fraction satisfies 5% or more. Further, an electrical property stabilizer, a processing improver, a pigment, a softening agent, and the like can be added within a range not impairing the object of the present invention.
Even when a low MFR component (A1) is used, if a small amount of the component (A2) based on a low MFR polypropylene resin is added, the MFR of the composition hardly changes or rather decreases. This suppression of molecular weight reduction becomes even more pronounced by the addition of magnesium oxide, zinc oxide, or the like.
[0019]
The polypropylene resin composition according to the present invention is a pellet-like material obtained by melt-kneading the (A1) component and the (A2) component polypropylene-based resin, one that has been press-molded, and injection molded into a product shape. It may take various forms such as
As a method for converting the β crystal of the polypropylene resin composition into α crystal, there are a method of adding an α crystal nucleating agent to the polypropylene resin composition, a method of heat-treating it into a molded product, a method of stretching, and the like. .
The method of heat-treating the molded product as it is is preferably performed at 130 ° C. or higher and lower than the melting temperature in an oven or oil.
As the stretching method, any stretching method (spinning, roll stretching, uniaxial and biaxial stretching, inflation molding, etc.) usually used industrially can be applied.
[0020]
The α crystal nucleating agent of the present invention will be described below.
The α crystal nucleating agent is a polymer compound such as polyethylene, polypropylene having a long chain branch, poly-3-methylbutene-1, poly-4-methylpentene-1. Further, metal salts of carboxylic acids such as talc, calcium carbonate, lithium carbonate, mica, aluminum borate, potassium titanate, basic magnesium sulfate, sodium benzoate, aluminum-pt-butylbenzoate, 1, 3, 2,4-dibenzylidene sorbitol, 1,3,2,4-bis (p-methylbenzylidene) sorbitol, 1,3,2,4-bis (p-ethylbenzylidene) sorbitol, 1,3-p-chlorobenzylidene Dibenzylidene sorbitol derivatives such as -2,4-p-methylbenzylidene sorbitol, sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2 ' -Ethylidene-bis (4,6-di-t-butylphenyl) phosphate, sodium Phosphate alkali metal salts such as bis (4-t-butylphenyl) phosphate, sodium-bis (4-t-methylphenyl) phosphate, potassium-bis (4,6-di-t-butylphenyl) phosphate It is effective to use an alkali metal salt such as
In order to improve rigidity, a phosphate alkali metal salt is preferable, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate is more preferably used. In order to improve transparency, it is preferable to use a sorbitol nucleating agent.
[0021]
The method for obtaining the polypropylene resin composition comprising the polypropylene resin composition and the α crystal nucleating agent in the present invention is a known method, for example, when obtained by melt-kneading with an extruder, either a single screw or biaxial extrusion. You may carry out using a machine.
By melting and mixing the above polypropylene resin composition and the α crystal nucleating agent, β crystal in the polypropylene resin composition is converted into α crystal.
The α crystal nucleating agent may be added to the polypropylene resin composition as it is, or, if necessary, a master batch prepared by kneading with a small amount of polypropylene resin may be added.
In order to increase the effect, it is preferable to add 0.01 to 30 parts by weight of the α crystal nucleating agent to 100 parts by weight of the polypropylene after forming the β crystal of the polypropylene resin. If the amount is 0.01 parts by weight or less, the effect is small, and if it is 30 parts by weight or more, the dispersion is unfavorable. More preferably, it is 0.05 to 20 parts by weight.
[0022]
The β-crystal of the polypropylene resin composition is at least partially converted, that is, a part or all of the β-crystal into the α-crystal and becomes a constituent element of the polypropylene resin material in the present invention.
Further, the β crystal fraction of the polyprolene resin composition is preferably 2% or less after conversion, more preferably 1% or less. If it is 2% or less, the physical properties, rigidity, heat resistance and transparency of the finally obtained polypropylene resin material will be better.
In addition, α ₁ And α ₂ A crystalline form of α ₂ Is known to be more stable. A large amount of this crystal form indicates high rigidity and high heat resistance.
[0023]
Further, the polypropylene resin material obtained in the present invention was preheated at 230 ° C. for 5 minutes using a special mold having a thickness of 2 mmt and 18 mm × 20 mm, deaerated, and then 50 kg for 5 minutes using a 30 ° C. cooling press. /cm ² Α when measured by X-ray when a sample prepared by pressurization is annealed at 160 ° C. for 2 hours ₂ And α ₁ Of scattering derived from (I ₂ ) And α ₁ Of scattering derived from (I ₁ ) Ratio R = I ₂ / I ₁ (R is α ₂ It is a measure of the amount of. ) Is 1 or more. Preferably it is 1.1 or more.
The X-ray scattering profile was measured using CuK rays monochromatized with a Ni filter of an X-ray generator (RU-200) manufactured by Rika Electric Co., Ltd. as a radiation source. α ₁ Α ₂ The standard R for the amount of G. Guerra, V. Petraccone, P. Corradini, C. De Rosa, R. Napoliano, and B. Pirozzi, J. Polm. Sci., Polm. Phys. Ed., Vol. , 1029 (1984), as follows. That is, after a baseline is drawn on the X-ray profile measured using CuK rays according to FIG. 1 of the same document, scattering between 2θ = 33.4 ° and 36.0 ° above the baseline (α ₁ And α ₂ Is the integrated intensity of ₂ And scattering between 2θ = 36.4 ° and 38.0 ° (α ₁ Is the integrated intensity of I) ₁ Asked. Their ratio R = I ₂ / I ₁ Α ₂ It was used as an indicator of the amount.
[0024]
The polypropylene resin material of the present invention was measured by MFR (g / 10 minutes) obtained based on JIS K-7210, Table 1, Condition 14, and differential scanning calorimetry (20 ° C./minute). It is desirable that the ratio (ΔHm / ΔHc) of the endothermic amount during melting (ΔHm (J / g)) to the exothermic amount during crystallization (ΔHc (J / g)) satisfies the following formula (Formula 3).
(Expression 3) ΔHm / ΔHc> 0.001515 log (MFR) +1.032
The fact that the calorific value (ΔHc) during crystallization is relatively small compared to the endothermic amount (ΔHm) during melting determined under these specific conditions is that the crystallization behavior of the composition of the present invention includes the above-mentioned It seems that there are more parts that cannot be detected by the differential scanning calorimetry, and this contributes to the improvement of the physical properties of the composition of the present invention as a result of affecting the crystallization behavior.
[0025]
When obtaining the polypropylene resin material of the present invention, if the polypropylene resin composition is a pellet-like material that has been melt-kneaded, or a material that has been once press-molded, etc., if necessary, the polypropylene-based resin material All additives such as a thermal oxidation stabilizer, a nucleating agent, a light stabilizer, an antistatic agent, and a lubricant other than those described above can be used before obtaining the above. Moreover, you may modify | denature partially using modifiers, such as radical initiators, such as a peroxide, and unsaturated carboxylic acid, in the range which satisfy | fills conditions. Furthermore, various olefin copolymers such as polyethylene, polybutene, ethylene-propylene copolymer, ethylene-butene copolymer, block copolymers having an ethylene block and an ethylene-butene block (hydrogenated-butadiene-block copolymer) Block copolymer such as block copolymer (hydrogenated-styrene-butadiene-block copolymer) having styrene block and ethylene-butene block, talc, calcium carbonate, lithium carbonate, mica, glass fiber, Inorganic fillers such as aluminum borate, potassium titanate and basic magnesium sulfate can also be mixed and used.
The addition, modification, or mixing may be performed at the stage of obtaining the polypropylene resin composition.
[0026]
【Example】
Examples of the present invention will be described below, but the present invention is not limited thereto. Various physical properties were measured by the following methods.
[0027]
(1) Measurement of isotactic pentad fraction (IP)
¹³ Using data obtained by C-NMR, calculation was performed by the method of A. Zambelli et al. (Macromolecules, 6,925 (1973)).
(2) MFR
Measured according to JIS K-7210, Table 1, Condition 14 (test temperature 230 ° C., test load 2.16 kgf).
(3) Flexural modulus
Measured by ASTM D790.
(4) HDT
Measured by ASTM D648.
(5) Measurement of haze (cloudiness value)
A press molded product was used as a sample. The press-molded product is 0.5 mmt, using a dedicated 10 cm x 10 cm mold, preheated at 230 ° C for 5 minutes, degassed, and 60 kg / cm ² Pressurize for 5 minutes and then use a cooling press at 30 ° C. for 5 minutes to 60 kg / cm ² The pressure was measured with a haze meter manufactured by Suga Test Instruments Co., Ltd. according to JIS K-7105.
[0028]
(6) β crystal fraction measurement (X-ray diffraction method)
Using a Cuk line obtained with an X-ray generator (RU-200) manufactured by Rigaku Denki Co., Ltd., monochromatized with a Ni filter as an X-ray source, a scattering angle (2θ) = 10 to 30 deg under measurement conditions of 50 KV and 150 mA. The X-ray scattering profile of the sample was determined in the range of. The β crystal fraction was calculated according to the above Macromol. Chem. 75, 134 (1964) after air scattering was corrected for the obtained scattering profile.
The measurement was performed using a press-formed product as a sample. The press-molded product is 0.5mmt, and it is deaerated after preheating at 230 ° C for 5 minutes using a special mold of 10cm x 10cm, 60kg / cm ² And pressurizing for 5 minutes at 60 kg / cm for 10 minutes each using a cooling press at 30 ° C and 100 ° C. ² Pressurized with Unless otherwise specified, the β crystal fraction refers to the value produced at 30 ° C. Further, the β crystal fractions of those produced at 30 ° C. and 100 ° C. were defined as β (30) and β (100), respectively.
(7) ESR measurement
Jeol JES-FE1XG manufactured by JEOL Ltd. is used for measurement, and a granular resin is placed in a sample tube for X-Bond (made of quartz) and measured at room temperature, in air, at 3360G and 100G magnetic fields and magnetic field sweep width. did. The frequency of the modulation magnetic field is 100 kHz, the magnitude is 6.3 G, and the response is 0.01 seconds.
[0029]
(8) R = I ₂ / I ₁ (R: α ₂ Measure of quantity)
The sample for measurement is a 2 mm thick 18 mm × 20 mm special mold, preheated at 230 ° C. for 5 minutes, degassed, and then cooled at 30 ° C. for 5 minutes at 50 kg / cm. ² It was produced by applying pressure.
The X-ray scattering profile was measured using CuK rays monochromatized with a Ni filter of an X-ray generator (RU-200) manufactured by Rika Electric Co., Ltd. as a radiation source. α ₁ Α ₂ As described above, the standard of the amount for G. Guerra, V. Petraccone, P. Corradini, C. De Rosa, R. Napoliano, and B. Pirozzi, J. Polm. Sci., Polm. Phys. Ed. , Vol. 22, 1029 (1984).
(9) Differential scanning calorimetry (DSC)
Using a DSC7 manufactured by PerkinElmer, about 4 mg of the film-like sample was held at 230 ° C. for 5 minutes, and then cooled to 30 ° C. at 20 ° C./min. Then, after hold | maintaining for 5 minutes at 30 degreeC, it heated up at 20 degree-C / min.
As shown in FIG. 1, ΔHc (J / g) is a temperature corresponding to the calorific value obtained when the temperature is lowered (Tcs (° C.)) and a temperature 40 ° C. lower than Tsc. Are connected by a straight line (baseline), and the area S surrounded by the baseline and the calorific value curve ₁ Was obtained by integrating.
As shown in FIG. 2, ΔHm (J / g) is a temperature corresponding to the endothermic amount obtained at the time of temperature rise (Tme (° C.)) and 65 ° C. lower than the Tme. An area S that connects the temperature with a straight line (baseline) and is surrounded by the baseline and the endothermic curve. ₂ Was obtained by integrating.
[0030]
[Production of polymer]
Preparation of solid catalyst components
(Step 1) Preparation of solid component
Under a nitrogen atmosphere, 47.6 g (500 mmol) of anhydrous magnesium chloride, 259 ml of decane and 234 ml (1.5 mol) of 2-ethylhexyl alcohol were heated at 130 ° C. for 2 hours to form a homogeneous solution, and then anhydrous. 11.1 g (75 mmol) of phthalic acid was added, and further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in the homogeneous solution. The obtained homogeneous solution was cooled to room temperature, and then added dropwise to 2.0 liters (18 mol) of titanium tetrachloride maintained at −20 ° C. over 1 hour. After completion of the dropwise addition, the temperature of the mixed solution was raised to 110 ° C. over 4 hours, and when it reached 110 ° C., 26.8 ml (125 mmol) of diisobutyl phthalate was added, and the mixture was stirred and reacted at 110 ° C. for 2 hours. After completion of the reaction, a solid component was collected by hot filtration, and then 2.0 liters (18 mol) of titanium tetrachloride was suspended in the reaction product, followed by treatment at 110 ° C. for 2 hours. After the treatment, the solid component was again collected by hot filtration, and washed 7 times with 2.0 liters of decane at 110 ° C. and 3 times with 2.0 liters of hexane at room temperature.
[0031]
(Step 2) TiCl _Four [C ₆ H _Four (COO ⁱ C _Four H ₉ ) ₂ Preparation of
To a 1.0 liter solution of hexane containing 19 g (100 mmol) of titanium tetrachloride, 27.8 g (100 mmol) of diisobutyl phthalate was added dropwise for about 30 minutes while maintaining 0 ° C. After completion of dropping, the temperature was raised to 40 ° C. and reacted for 30 minutes. After completion of the reaction, the solid component was collected and washed 5 times with 500 ml of hexane to obtain the desired product.
(Step 3) TiCl _Four [C ₆ H _Four (COO ⁱ C _Four H ₉ ) ₂ ] Processing
40 g of the solid component obtained in the above step 1 is suspended in 600 ml of toluene, and TiCl is suspended at 25 ° C. _Four [C ₆ H _Four (COO ⁱ C _Four H ₉ ) ₂ It was reacted with 10.3 g (22 mmol) for 1 hour. After completion of the reaction, 200 ml (1.8 mol) of titanium tetrachloride was added and reacted at 110 ° C. for 2 hours. After completion of the reaction, a solid component was collected by hot filtration, and then 600 ml of toluene and 200 ml of titanium tetrachloride (1.8 mol) were suspended in the reaction product, followed by reaction at 110 ° C. for 2 hours. . After completion of the reaction, the solid component was again collected by hot filtration, and washed 7 times with 1.0 liter of toluene at 110 ° C. and 3 times with 1.0 liter of hexane at room temperature.
[0032]
Preparation of prepolymerization catalyst components
In an autoclave having an internal volume of 3 liters under a nitrogen atmosphere, 500 ml of n-heptane, 6.0 g (0.053 mol) of triethylaluminum, 3.1 g (0.017 mol) of t-butyltrimethoxysilane, and the above obtained. Then, 100 g of the solid catalyst component was added and stirred for 5 minutes in a temperature range of 0 to 5 ° C. Next, propylene was fed into the autoclave so that 10 g of propylene per 1 g of the solid component was polymerized, and prepolymerized at a temperature range of 0 to 5 ° C. for 1 hour. The obtained prepolymerization catalyst was washed with 500 ml of n-heptane three times and used for the following polymerization.
[0033]
[Propylene polymerization (A1 component)]
(PP-1)
Polymerization was carried out as follows using one autoclave equipped with a stirrer having an internal volume of 60 liters under a nitrogen atmosphere. Pre-polymerization catalyst component 2.0 g prepared by the above method, triethylaluminum 11.4 g (100 mmol), t-butyltrimethoxysilane 5.9 g (33 mmol) were added, then propylene 18 kg, polymer MFR 0.5 g / 10 minutes, hydrogen was supplied, and polymerization was performed at 70 ° C. for 30 minutes. Unreacted gas was purged to obtain the target polypropylene. The isotactic pentad fraction of PP was 0.994. The obtained PP had an MFR of 0.5 g / 10 min.
(PP-2)
Using 6g of AA-type titanium trichloride manufactured by Tosoh Akzo Co., Ltd. and 23.5g of diethylaluminum chloride as catalyst components, hydrogen was supplied so that 18kg of propylene and MFR of the polymer would be 0.5g / 10min. Polymerization was carried out for minutes. Unreacted gas was purged to obtain the target polypropylene. The isotactic pentad fraction of PP was 0.941. The obtained PP had an MFR of 0.5 g / 10 min.
[0034]
(PP-3)
In a nitrogen atmosphere, polymerization was performed as follows using one autoclave equipped with a stirrer having an internal volume of 60 liters. Pre-polymerization catalyst component 2.0 g prepared by the above method, triethylaluminum 11.4 g (100 mmol), t-butyltrimethoxysilane 5.9 g (33 mmol) were added, then propylene 18 kg, polymer MFR 30 g / 10 Hydrogen was supplied so that the amount of water reached 30 minutes, and polymerization was carried out at 70 ° C. for 30 minutes. Unreacted gas was purged to obtain the target polypropylene. The PP obtained had an isotactic pentad fraction of 0.994. The obtained PP had an MFR of 32.8 g / 10 min.
(PP-4)
In a nitrogen atmosphere, polymerization was performed as follows using one autoclave equipped with a stirrer having an internal volume of 60 liters. The prepolymerization catalyst component 2.0g prepared by the above method, 11.4 g (100 mmol) of triethylaluminum, and 5.9 g (33 mmol) of t-butyltrimethysilane were added, followed by 18 kg of propylene, and the polymer had an ethylene content of 2 Ethylene and hydrogen were supplied so that 0.0% by weight and MFR was 2.5 g / 10 minutes, and polymerization was performed at 70 ° C. for 30 minutes. Unreacted gas was purged to obtain the desired propylene-ethylene copolymer. The random copolymer obtained had an MFR of 2.2 g / 10 min and an ethylene content of 1.7% by weight.
[0035]
Table 1 shows the properties of the polypropylene resin of each A1 component.
[Table 1]

[0036]
[Production of γ-irradiated polypropylene resin (A2 component)]
(ΓPP-1)
Using PP-1 (MFR = 0.5 g / 10 min, IP = 0.994: satisfying (Equation 2) in the text) using γ-ray irradiation device (automatic irradiation table) of Koga Isotope Co., Ltd. Then, irradiation was performed at 50 kGy (minimum dose 47.5 kGy, maximum dose 52.6 kGy, measured with a perspex line meter) in an atmosphere having an active oxygen concentration of 5.6%. The MFR after irradiation was 5.6 g / 10 min. The presence of peroxide radical was confirmed by ESR measurement.
(ΓPP-2)
Using PP-2 (MFR = 0.5 g / 10 min, IP = 0.941: not satisfying (Equation 2) in the text) using the γ-ray irradiation device (automatic irradiation stand) of Koga Isotope Co., Ltd. Then, irradiation was performed at 50 kGy (minimum dose 47.5 kGy, maximum dose 52.6 kGy, measured with a perspex line meter) in a nitrogen atmosphere with an active oxygen concentration of 4.8%. The MFR after irradiation was 17.0 g / 10 min. The presence of peroxide radical was confirmed by ESR.
[0037]
[Table 2]

[0038]
[Temperature dependence of β crystal fraction]
Di-t-butyl-p-cresol with respect to 100 parts by weight of the polypropylene resin composition comprising 90% by weight of PP-1 as component (A1) and 10% by weight of γPP-1 as component (A2). 0.08 parts by weight of (BHT) and 0.03 parts of pentaerythrityltetrakis [3- (3,5-di-t-butyl-4-butylhydroxyphenyl) propionate] (“Irganox 1010” manufactured by Ciba Geigy Japan) 05 parts by weight and 0.1 part by weight of calcium stearate (“calcium stearate”) were mixed and pelletized at 230 ° C.
Using a high-pressure press machine (manufactured by Shoji Tekko Co., Ltd.), after preheating at 230 ° C. for 5 minutes and degassing for 30 seconds, 60 kg / cm ² And left for 5 minutes, followed by crystallization at a specific cooling temperature (30 ° C. to 100 ° C.) for 10 minutes to produce a 10 cm × 10 cm press sheet with a thickness of 0.5 mm. The temperature dependence of the β crystal fraction of the obtained press sheet is shown by “− ◯ −” in FIG.
For comparison, the same evaluation was performed for pellets made of the following two types of polypropylene resin compositions, and the results are shown in FIG.
To 100 parts by weight of PP-11, 0.08 parts by weight of BHT, 0.05 parts by weight of Irganox 1010 and 0.1 parts by weight of calcium stearate were added and mixed. A twin-screw extruder (“KTX-37” Kobe) A pellet was prepared by melting and kneading at 230 ° C. using a steel mill), and the same evaluation was performed. This is indicated by “− ● −” in FIG.
Furthermore, with respect to 100 parts by weight of PP-11, 0.08 parts by weight of BHT, 0.05 part by weight of Irganox 1010, 0.1 part by weight of calcium stearate, β-crystal nucleating agent (“Nestar NU-100” New Nippon Rika Co., Ltd.) was added, and the mixture was melt-kneaded at 230 ° C. using a twin-screw extruder (“KTX-37”) to produce pellets, and the same evaluation was performed. In FIG. 3, this is indicated by “− □ −”.
As is clear from FIG. 3, the polypropylene resin composition (-○-) in the present invention is different from the polypropylene resin composition of the comparative example, but rather has a feature that many β crystals are produced at a low temperature. Have.
[0039]
[Production of polypropylene resin material]
Examples 1-11, Comparative Examples 2, 3, 6, 7-15, 19
Tables 1 and 2 show the types and blending amounts of the (A1) component polypropylene resin, the (A2) component γ-irradiated polypropylene resin and BHT in 0.05 parts by weight, and Irganox 1010 in 0 parts. 0.1% by weight and 0.1 part by weight of calcium stearate are mixed and mixed using a super mixer (“SMV20 type” manufactured by Kawada Seisakusho Co., Ltd.), and a twin screw extruder (“AS30 type” manufactured by Nakatani Machine Co., Ltd.) is used. Used and pelletized at a temperature of 230 ° C. (200 ° C. using PP-3). The screw speed of the extruder was 100 rpm.
[0040]
Examples 1 and 2 (examples using crystal conversion from β crystal to α crystal by heat treatment), Comparative Examples 1 to 3
Example 1
(A1) 97 parts by weight of PP-1 as component and (A2) 100 parts by weight of resin of 3% by weight of γPP-1 as a component, 0.05 part by weight of BHT and 0.1 part by weight of Irganox 1010 A pellet-shaped polypropylene resin composition was obtained by the above method using 0.1 part by weight of calcium stearate. A test piece for measuring the β crystal fraction was prepared using the pellet (the β crystal fraction of the obtained press test piece was 43%). This test piece was heated in an oven adjusted to 150 ° C. in a nitrogen atmosphere for 2 hours and then cooled to room temperature to obtain a polypropylene resin material (β crystal fraction was 0%). After the conditioning, the physical properties of this test piece were measured. The results are shown in Table 3.
[0041]
(Example 2)
The same procedure as in Example 1 was performed except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). The β crystal fraction of the press specimen before the heat treatment was 47%.
(Comparative Example 1)
To 100 parts by weight of PP-1, 0.08 parts by weight of commercially available stabilizer BHT, 0.05 parts by weight of Irganox 1010 and 0.1 parts by weight of calcium stearate were added, and a twin screw extruder (“KTX -37 ") was melt-kneaded at 230 ° C to produce a pellet-shaped polypropylene resin composition. A test piece for measuring the β crystal fraction was prepared using the pellet (the β crystal fraction of the obtained press test piece was 0%). The test piece was heated in an oven adjusted to 150 ° C. for 2 hours under a nitrogen atmosphere, and then cooled to room temperature. After adjusting the condition of the test piece, the physical properties were measured. The results are shown in Table 3.
(Comparative Example 2)
Example 1 except that PP-2 (MFR = 0.6 g / 10 min, IP = 0.941) 90% by weight as component (A1) and 10% by weight of the above-mentioned γPP-2 as component (A2) were used. As well as. The β crystal fraction of the press specimen before the heat treatment was 2%.
[0042]
(Comparative Example 3)
The physical properties of the specimen (β crystal fraction = 47%) before heat treatment of Example 2 were measured. The results are shown in Table 3.
[Table 3]

Examples 3 to 9 (examples using crystal conversion from β crystal to α crystal by α crystal nucleating agent), Comparative Examples 4 to 15
Example 3
A pellet-shaped polypropylene resin composition was obtained by the above method using 99% by weight of PP-1 as the component (A1) and 1% by weight of γPP-1 as the component (A2). The test piece for measuring the β crystal fraction was prepared from this pellet.
Sodium-2,2′-methylene-bis (4,6-di-t-butyl) as a nucleating agent for α-crystal with respect to 100 parts by weight of the obtained test piece (β-crystal fraction 26%). Phenyl) phosphate (“NA11” manufactured by Asahi Denka Co., Ltd.) was added in an amount of 0.4 part by weight, and melt-kneaded at 230 ° C. using a twin screw extruder (KTX-37) to obtain a polypropylene resin material. . A test piece was prepared using the obtained polypropylene resin material (β crystal fraction 0%), and the physical properties were measured. The results are shown in Table 4.
[0043]
(Example 4)
The same procedure as in Example 3 was conducted, except that 98% by weight of PP-1 was used as the component (A1) and 2% by weight of γPP-1 was used as the component (A2). Polypropylene-based resin composition has a β-crystal fraction of 39%, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”), which is an α-crystal nucleating agent The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 4.
(Example 5)
The same procedure as in Example 3 was conducted, except that 97% by weight of PP-1 was used as the component (A1) and 3% by weight of γPP-1 was used as the component (A2). Polypropylene resin composition has a β-crystal fraction of 42%, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”), which is an α-crystal nucleating agent The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 4.
[0044]
(Example 6)
The same procedure as in Example 3 was performed except that 95% by weight of PP-1 was used as the component (A1) and 5% by weight of γPP-1 was used as the component (A2). Β-crystal fraction of the polypropylene resin composition is 43%, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”), which is the nucleating agent of α-crystal The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 4.
(Example 7)
The same procedure as in Example 3 was performed except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). Β-crystal fraction of the polypropylene resin composition is 47%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”) which is an α-crystal nucleating agent The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 5.
[0045]
(Example 8)
The same procedure as in Example 3 was carried out except that 85% by weight of PP-1 was used as the component (A1) and 15% by weight of γPP-1 was used as the component (A2). Β-crystal fraction of the polypropylene resin composition is 47%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”) which is an α-crystal nucleating agent The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 5.
Example 9
The procedure was the same as Example 3 (provided that the mixture was melt-kneaded at 200 ° C.), except that PP-3 was used as the component (A1) 90% by weight and γPP-1 was used 10% by weight as the component (A2). Polypropylene resin composition has a β-crystal fraction of 17%, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”), which is an α-crystal nucleating agent The β crystal fraction of the polypropylene resin material prepared by adding 0.4 parts by weight of 0 was 0%. The results are shown in Table 5.
[0046]
[Table 4]

[0047]
[Table 5]

[0048]
(Comparative Example 4)
To 100 parts by weight of PP-1, 0.08 parts by weight of commercially available stabilizer BHT, 0.05 parts by weight of Irganox 1010 and 0.1 parts by weight of calcium stearate were added, and a twin screw extruder (KTX- 37) was melt-kneaded at 230 ° C. to produce pellet-shaped polypropylene. Sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate (Asahi Denka Co., Ltd.) as a nucleating agent for α-crystal with respect to 100 parts by weight of this pellet (β-crystal fraction 0%) 0.4 parts by weight of “NA11” manufactured) was added and melt-kneaded at 230 ° C. using a twin-screw extruder (KTX-37) to produce a polypropylene resin material. A test piece was prepared using this, and the physical properties were measured. The results are shown in Table 6.
(Comparative Example 5)
The procedure was the same as Comparative Example 4 except that PP-3 was used instead of PP-1 (however, melt-kneading at 200 ° C.). The β crystal fraction of the pellets corresponding to the polypropylene resin composition was 0%. A test piece was prepared using a polypropylene resin material, and the physical properties were measured. The results are shown in Table 6.
[0049]
(Comparative Example 6)
Melting and mixing at 230 ° C. using a twin screw extruder (KTX-37) by the above method using 99% by weight of PP-1 as component (A1) and 1% by weight of γPP-1 as component (A2) After kneading, in a molten state, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11” manufactured by Asahi Denka Co., Ltd.) is used as an α crystal nucleating agent. .4 parts by weight were added to produce a pellet-shaped polypropylene resin material. A test piece was prepared using this, and the physical properties were measured. The results are shown in Table 6.
(Comparative Example 7)
The same procedure as in Comparative Example 6 was performed except that 98% by weight of PP-1 was used as the component (A1) and 2% by weight of γPP-1 was used as the component (A2). The results are shown in Table 6.
(Comparative Example 8)
The same procedure as in Comparative Example 6 was carried out except that 97% by weight of PP-1 was used as the component (A1) and 3% by weight of γPP-1 was used as the component (A2). The results are shown in Table 7.
[0050]
(Comparative Example 9)
The same procedure as in Comparative Example 6 was carried out except that 95% by weight of PP-1 was used as component (A1) and 5% by weight of γPP-1 was used as component (A2). The results are shown in Table 7.
(Comparative Example 10)
The same procedure as in Comparative Example 6 was performed except that PP-1 was used as 90% by weight as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). The results are shown in Table 7.
(Comparative Example 11)
The same procedure as in Comparative Example 6 was performed except that 85% by weight of PP-1 was used as the component (A1) and 15% by weight of γPP-1 was used as the component (A2). The results are shown in Table 7.
(Comparative Example 12)
It was carried out in the same manner as in Comparative Example 6 (provided that the mixture was melt-kneaded at 200 ° C.) except that PP-3 was used as 90% by weight as the component (A1) and 10% by weight was used as the component (A2). The results are shown in Table 8.
(Comparative Example 13)
A pellet-shaped polypropylene resin composition was obtained by the above method using 90% by weight of PP-2 as the component (A1) and 10% by weight of γPP-2 as the component (A2). From this pellet, the above-mentioned test piece for measuring the β crystal fraction was prepared. Sodium-2,2′-methylene-bis (4,6-di-t-butyl) as a nucleating agent for α-crystal with respect to 100 parts by weight of the obtained test piece (β-crystal fraction 2%). Phenyl) phosphate (“NA11” manufactured by Asahi Denka Co., Ltd.) was added in an amount of 0.4 part by weight, and melt-kneaded at 230 ° C. using a twin screw extruder (KTX-37) to obtain a polypropylene resin material. . A test piece was prepared using the obtained polypropylene resin material, and the physical properties were measured. The results are shown in Table 8.
[0051]
(Comparative Example 14)
A pellet-shaped polypropylene resin composition was obtained by the above method using 97% by weight of PP-1 as the component (A1) and 3% by weight of γPP-1 as the component (A2). From this pellet, a press sheet having a thickness of 0.5 mm and a thickness of 10 cm × 10 cm was produced at a press temperature of 135 ° C. based on the method shown in the column of “temperature dependence of β crystal fraction” described above. Sodium-2,2′-methylene-bis (4,6-di-t-) is used as an α crystal nucleating agent with respect to 100 parts by weight of the primary molded product obtained by cutting the obtained press sheet (β crystal fraction 0%). Add 0.4 parts by weight of (butylphenyl) phosphate ("NA11" manufactured by Asahi Denka Co., Ltd.) and melt knead it at 230 ° C using a twin screw extruder (KTX-37) to obtain a polypropylene resin material. It was. A test piece was prepared using the obtained resin material, and the physical properties were measured. The results are shown in Table 8.
(Comparative Example 15)
The same procedure as in Comparative Example 14 was carried out except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). The β crystal fraction of the obtained polypropylene resin composition sheet (primary molded product) was 0%. The results are shown in Table 8.
[0052]
(Comparative Example 16)
New Nippon Rika Co., Ltd. as a nucleating agent of β-crystals, with 0.08 parts by weight of commercially available stabilizer BHT, 0.05 parts by weight of Irganox 1010, 0.1 parts by weight of calcium stearate, and 100 parts by weight of PP-3 0.2 parts by weight of “NJ Star NU-100” manufactured by the company was added and melt-kneaded at 200 ° C. using a twin screw extruder (KTX-37) to produce pellets. From this pellet, the above-mentioned press sheet for measuring the β crystal fraction (however, crystallized at 100 ° C.) was produced.
Sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) is used as the α crystal nucleating agent with respect to 100 parts by weight of the obtained press sheet (β crystal fraction: 47%). ) Add 0.4 parts by weight of phosphate ("NA11" manufactured by Asahi Denka Co., Ltd.) and melt knead at 200 ° C using a twin screw extruder (KTX-37) to produce a pellet-like polypropylene resin material. Got. The β crystal fraction of this resin material was 6%. A test piece was prepared using this resin material, and the physical properties were measured. The results are shown in Table 9.
[0053]
[Table 6]

*: PP resin material produced without passing through β-crystal-containing pellets.
[0054]
[Table 7]

*: PP resin material produced without passing through β-crystal-containing pellets.
[0055]
[Table 8]

*: PP resin material produced without passing through β-crystal-containing pellets.
**: The β crystal fraction of the primary compact (crystallized at 130 ° C.) before addition of the α crystal nucleating agent is 0%.
[0056]
[Table 9]

In addition, rigidity and heat resistance greatly depend on the MFR of the resin. When Examples 1-8 and Comparative Examples 1-4, 6-11, 13-15 are low MFR, it corresponds to the case where Example 9 and Comparative Examples 5, 12, 16 are high MFR. It can be seen from Tables 3 to 9 that the MFR of the same degree is superior in rigidity and heat resistance to the polypropylene resin material of the example as compared with the polypropylene resin material of the comparative example.
[0057]
Examples 10 and 11 (examples using crystal conversion from β crystal to α crystal by α crystal nucleating agent), Comparative Example 19
(Example 10)
Using PP-1 as the component (A1) 95% by weight, 5% by weight γPP-1 as the component (A2), 1,3,2,4-bis (p-methylbenzylidene) sorbitol (new) as the α crystal nucleating agent This was performed in the same manner as in Example 3 except that 0.3% by weight of “Gelall MD-R” manufactured by Nippon Rika Corporation was used. The results are shown in Table 10.
(Example 11)
Implemented except that 95% by weight of PP-4 was used as the component (A1), 5% by weight of γPP-1 was used as the component (A2), and 0.25% by weight of “Gelol MD-R” was used as the α crystal nucleating agent. Performed as in Example 3. The results are shown in Table 10.
(Comparative Example 19)
Comparative Example 9 was carried out except that 95% by weight of PP-1 and 5% by weight of γPP-1 were used, and 0.3% by weight of “Gelol MD-R” was used as the α crystal nucleating agent. The results are shown in Table 10.
[0058]
[Table 10]

*: PP resin material produced without passing through β-crystal-containing pellets.
[0059]
(Comparative Example 17)
The same operation as in Comparative Example 4 was conducted except that 100 parts by weight of PP-1 was used and no nucleating agent was used. The results are shown in Table 11.
(Comparative Example 18)
The same method as in Comparative Example 4 was carried out except that 100 parts by weight of PP-1 was used and 0.3% by weight of “Gelol MD-R” was used as the α crystal nucleating agent. The results are shown in Table 11.
(Comparative Example 20)
The same operation as in Comparative Example 4 was conducted except that 100 parts by weight of PP-4 was used and no nucleating agent was used. The results are shown in Table 11.
(Comparative Example 21)
The same procedure as in Comparative Example 4 was conducted except that 100 parts by weight of PP-4 was used and 0.25% by weight of “Gelol MD-R” was used as the α crystal nucleating agent. The results are shown in Table 11.
[0060]
[Table 11]

[0061]
【The invention's effect】
The polypropylene resin material of the present invention is very excellent in rigidity, heat resistance and transparency as compared with the conventional one. Therefore, it is particularly suitable for use as an alternative to engineering plastics as a structural material used in injection molding, hollow molding, sheet molding, vacuum molding and the like.
[Brief description of the drawings]
FIG. 1 is a graph showing a calorific value curve during crystallization by differential scanning calorimetry.
FIG. 2 is a graph showing an endothermic curve during melting by differential scanning calorimetry.
FIG. 3 is a graph showing the press temperature dependence of the β crystal fraction.
FIG. 4 is an ESR spectrum of polypropylene.

Claims (9)

Β crystal fraction when measured using a press-molded product that is crystallized isothermally at 30 ° C. is 5% or more,
When the β crystal content at the time of isothermal crystallization at 30 ° C. and 100 ° C. is β (30) and β (100), (Equation 1) is satisfied,
(Formula 1) β (30)> β (100)
In addition, at least part of the β crystal of the polypropylene resin composition having a melt flow rate of 0.05 to 1000 g / 10 min is added to 0.01 to 30 parts by weight of alkali with respect to 100 parts by weight of the polypropylene resin composition. A method for producing a polypropylene-based resin material, which is converted into α-crystals by either adding an α-crystal nucleating agent comprising a metal salt or a dibenzylidene sorbitol derivative , or performing a heat treatment at 130 ° C. or higher. 70% to 99.5% by weight of a polypropylene resin having a melt flow rate of 0.05 to 1000 g / 10 min, and a polypropylene resin having the following physical properties (a) and (b), in the air or 1% of active oxygen It is obtained by melt-kneading 0.5 to 30% by weight of a resin that has been treated to generate peroxide radicals by γ-ray irradiation in an inert gas atmosphere containing the above, in a state in which the peroxide radicals are not deactivated before melting. A method for producing a polypropylene resin material, comprising converting at least part of β crystals of a polypropylene resin composition having a β crystal fraction of 5% or more to α crystals.
(A) Melt flow rate is 5 g / 10 min or less (b) Isotactic pentad fraction (abbreviated as IP) and melt flow rate (abbreviated as MFR) have the relationship of (Equation 2) (Equation 2) IP> 0.0428 × log (MFR) +0.97   3. The method for producing a polypropylene resin material according to claim 1, wherein at least a part of the β crystal is converted to α crystal, and the β crystal fraction is 2% or less.   The method for producing a polypropylene resin material according to claim 1 or 2, wherein the polypropylene resin composition has a propylene chain isotactic pentad fraction of not less than 0.970. Method for producing a polypropylene-based resin material according to claim 1, wherein the alkali metal salt is phosphate alkali metal salt. Alkali metal salts are sodium-2,2'-methylene - bis manufacturing method of (4,6-di -t- butyl-phenyl) Polypropylene-based resin material according to claim 1, wherein it is a phosphate. The method for producing a polypropylene-based resin material according to claim 1, wherein the dibenzylidene sorbitol derivative is 1,3,2,4-bis (p-methylbenzylidene) sorbitol.   A polypropylene resin material obtained by the production method according to claim 1. In the polypropylene resin material according to claim 8,
The melt flow rate is 0.05 to 1000 g / 10 minutes,
A polypropylene resin material characterized in that a melt flow rate (MFR) and a ratio of an endothermic amount ΔHm at the time of melting and an exothermic amount ΔHc at the time of crystallization measured by a differential scanning calorimetry method satisfy (Equation 3) .
(Expression 3) ΔHm / ΔHc> 0.001515 log (MFR) +1.032

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