JP4555494B2

JP4555494B2 - Vinyl chloride resin composition

Info

Publication number: JP4555494B2
Application number: JP2001088205A
Authority: JP
Inventors: 喜弘久保; 秀樹井上
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 2001-03-26
Filing date: 2001-03-26
Publication date: 2010-09-29
Anticipated expiration: 2021-03-26
Also published as: JP2002284950A

Description

【０００１】
【発明の属する技術分野】
本発明は、塩化ビニル系樹脂組成物に関する。
【０００２】
【従来の技術】
塩化ビニル樹脂（以下、ＰＶＣという）は機械的強度、耐候性、耐薬品性に優れており、他のプラスチック材料と比較しても安価であることから、給排水パイプ、プレート、継手等の幅広い分野で利用される汎用樹脂である。しかしながら、ＰＶＣは熱変形温度が低く使用可能な上限温度が６０〜７０℃付近であるため、熱水が流れる給湯管やプラント管などには使用が困難であった。そこでＰＶＣの高温での耐久性能を向上させるため、ＰＶＣを塩素化して耐熱性を向上させた塩素化塩化ビニル樹脂（以下ＣＰＶＣという）が開発された。この樹脂を用いた配合設計によりＰＶＣの易施工性、易接着性と耐熱性、耐衝撃性を併せ持った管が利用できる様になってきた。（特開平４−３５９９２８号公報）この様に給湯用配管やプラント用の超純水配管では問題のない管の開発が行われてきたが、一方でアルカリ水溶液が流れるプラント分野でのライン配管では、耐薬品性に優れる硬質塩化ビニル管においても、長期の使用により劣化が進み、さらに内圧や脈動、支持部で発生する応力や、膨脹伸縮による発生する応力が加わり亀裂が進行する、環境応力割れ(以下ＥＳＣ)が発生し、管の破壊、破裂や薬液の流出が問題となる場合があった。
【０００３】
【発明が解決しようとする課題】
本発明は、上記課題に鑑み、優れた耐アルカリ性をもつＰＶＣ成形品を得ることができる塩化ビニル系樹脂組成物を提供することにある。
【０００４】
【課題を解決するための手段】
本発明の塩素化塩化ビニル系樹脂組成物は、電子分光化学（ＥＳＣＡ）分析による粒子表面分析において、
炭素原子と塩素原子の１ｓ結合エネルギー値（ｅＶ）のピーク比が０.６を超えるもので、水銀圧入法（圧力０〜１９６ＭＰａ）による細孔容積分布において、０.００１〜０.１μｍの範囲の空隙容積が全空隙容積中の２〜１５容積％である塩化ビニル樹脂を塩素化することにより得られる塩素化塩化ビニル樹脂１００重量部に対して、
塩化ビニル樹脂及び改質剤が添加され、改質剤成分が４重量部以上３０重量部未満で且つ、塩化ビニル樹脂成分と改質剤成分との合計が１０重量部以上である塩素化塩化ビニル系樹脂組成物であって、
上記改質剤成分がシリコンアクリル系改質剤と塩素化ポリエチレン系改質剤との組合せからなり、
上記樹脂組成物より、ＪＩＳＫ７１１３に準拠して作製した引張試験片を、表面最大発生応力が１.８６〜１.９６ＭＰａとなるように円弧に曲げた状態で、濃度１４ｗｔ％のＫＯＨ水溶液中に、５０℃で７２時間浸漬した後の破断伸び（Ｅａ）と、浸漬する前の破断伸び（Ｅｂ）から、次式（１）により計算される破断伸び保持率が３０％以上であることを特徴とする。
破断伸び保持率（％）＝Ｅａ／Ｅｂ ×１００ …（１）
【０００６】
アルカリによる塩化ビニル系樹脂成形品のＥＳＣは、塩化ビニル系樹脂組成物が接触するアルカリにより劣化することと、塩化ビニル成形品に応力が発生している場合に起こる現象であり、双方どちらが欠けてもＥＳＣという現象はおこらない。
【０００７】
本願発明者は、上記知見に基づき誠意検討した結果、引張試験片（ＪＩＳＫ７１１３：２号試験片）を表面最大発生応力が１８.６〜１９.８ＭＰａとなるよう円弧に曲げた状態で、濃度１４ｗｔ％ＫＯＨ水溶液中に、５０℃で７２時間浸漬した後の破断伸び（Ｅａ）と、浸漬する前の破断伸び（Ｅｂ）から、式（１）により計算される破断伸び保持率（％）が３０以上である時、アルカリ使用時においてもＥＳＣが発生しにくいことを明らかにした。
これは、上記破断伸び保持率が３０％以上である塩素化塩化ビニル系樹脂組成物は、アルカリによる材料の劣化が起こりにくいか、もしくは初期に発生させた応力が緩和しやすい為である。その結果、成形品の表面に発生する微少なＥＳＣが抑制され、破断伸びの低下が抑制されるものと考えられる。
【０００８】
上記破断伸び保持率が３０より小さいと、通常の使用条件でＥＳＣが発生、徐々に成長し、長期使用した場合、成形品の破壊や、薬液の漏洩を引き起こす可能性が高いため、破断伸び保持率は３０以上に限定され、より好ましくは６０以上である。
【０００９】
上記塩化ビニル樹脂は（ＰＶＣ樹脂）は，塩化ビニル単量体（以下、ＶＣＭという）単独，又は，ＶＣＭ及びＶＣＭと共重合可能な他の単量体の混合物を公知の方法（例えば、懸濁重合、塊状重合等）で重合してなる樹脂である。上記ＶＣＭと共重合可能な他の単量体としては特に限定されず、例えば、酢酸ビニル等のアルキルビニルエステル類、エチレン、プロピレン等のα−モノオレフィン類、塩化ビニリデン、スチレン等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００１０】
上記ＰＶＣ樹脂は、電子分光化学（ＥＳＣＡ）分析による表面分において、炭素原子と塩素原子の１ｓ結合エネルギー値（ｅＶ）のピーク比が０.６を超えるものである。上記炭素原子と塩素原子の１ｓ結合エネルギー値（ｅＶ）におけるピーク比が０.６以下では、ＰＶＣ粒子表面に分散剤等の添加剤が吸着していると考えられるため、後工程での塩素化速度が遅くなるだけではなく、得られるＣＰＶＣが均一混練されにくくなり耐薬性にも好ましくはない。また、熱安定性が劣るようになる。より好ましくは、上記ピーク比が０.７を超えるものである。なお、上記ＰＶＣ中の塩素原子と炭素原子のとの存在比は、塩素原子／炭素原子＝１／２であり（末端構造、分岐を考慮しないとき）、上記１ｓ結合エネルギー値（ｅＶ）におけるピーク比（塩素原子ピーク×２／炭素原子ピーク）は０〜１の値となる。ピーク比が０の場合は、ＰＶＣ粒子表面がＰＶＣ以外で、かつ、塩素を含まない他の物質により覆われていることを意味し、ピーク比が１の場合は、ＰＶＣ粒子表面が、完全に塩化ビニル成分のみで覆われていることを意味する。
【００１１】
上記ＰＶＣの細孔分布は、水銀圧入法（測定圧力範囲は０〜１９６ＭＰａ）による測定細孔容積分布において、０.００１〜０.１μｍの範囲の空隙容積が全空隙容積中に占める空隙容積率は２〜１５容積％である。上記空隙容積率が２容積％未満であると、粒子内部の微細孔の割合が少なく、成形加工時のゲル化性に劣り耐薬性にも好ましくはない、また、１５容積％を超えると、塩素化時の塩素の拡散がバランスよく行われず、粒子内の塩素含有率分布が広くなりすぎて、熱安定性が良くない。より好ましい容積分率は２〜１５容積％である。
【００１２】
本発明のＣＰＶＣ樹脂は上記ＰＶＣ樹脂を塩素化して得られる樹脂であればよく、塩素化度も特に限定されるものではない。また２種以上のＣＰＶＣが併用されてもよい。
ＰＶＣを塩素化する方法としては特に限定されず、従来公知の各種方法で行うことができる。例えば、上記ＰＶＣを懸濁した状態、溶剤に溶解した状態、又は固体状態とした後、塩素と接触させること等により行うことができる。
【００１３】
上記塩素化塩化ビニル系樹脂組成物は、上記塩素化塩化ビニル樹脂、改質剤、塩化ビニル樹脂よりなる。上記改質剤としては、シリコンアクリル系改質剤と塩素化ポリエチレン（ＣＰＥ）系改質剤との組合せである。耐アルカリ性の面からこの組合せがよい。これらは単独で用いてもよく、２種以上を併用してもよい。上記改質剤の添加量は、塩素化塩化ビニル樹脂１００重量部に対して、４重量部以上である。４重量部未満の場合には十分な耐アルカリ性が得られない。また、塩化ビニル樹脂成分と改質剤成分の合計が１０重量部以上である。１０重量部未満の場合は耐アルカリ性が低下することがあり好ましくなく、より好ましくは１３重量部以上である。一方改質剤が多すぎると、アルカリによる改質剤成分の劣化や塩素化塩化ビニル樹脂との相溶性が低下し、耐衝撃性が低下してしまう場合があるので、改質剤の量は塩素化塩化ビニル樹脂１００重量部に対して３０重量部未満である。
【００１４】
上記ＣＰＶＣ系樹脂組成物をには、安定剤、加工助剤、滑剤、酸化防止剤、光安定剤、紫外線吸収剤、帯電防止剤、顔料、充填剤、可塑剤等の一般に塩化ビニル系樹脂の成形時に用いられている配合剤を、本発明の目的を損なわない範囲で必要に応じて配合してもよい。
【００１５】
上記安定剤としては特に限定されず、例えば、熱安定剤、熱安定化助剤等が挙げられる。上記熱安定剤としては、例えば、ジメチル錫メルカプト、ジブチル錫メルカプト、ジオクチル錫メルカプト等の有機錫系安定剤、カルシウム−亜鉛系安定剤、バリウム−亜鉛系安定剤、バリウムーカドミウム系安定剤、ステアリン酸鉛等の鉛系安定剤等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００１６】
また、上記熱安定化助剤としては特に限定されず、例えば、エポキシ化大豆油、りん酸エステル等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００１７】
上記安定剤及び安定化助剤の添加量は本発明の目的を損なわない範囲であれば特に限定されない。
【００１８】
上記加工助剤としては特に限定されず、例えば、重量平均分子量１０万〜２００万のアルキルアクリレート／アルキルメタクリレート共重合体等のアクリル系加工助剤等が挙げられる。具体的には、ｎ−ブチルアクリレート／メチルメタクリレート共重合体、２−エチルヘキシルアクリレート／メチルメタクリレート／ブチルメタクリレート共重合体等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。上記加工助剤の添加量は本発明の目的を損なわない範囲であれば特に限定されない。
【００１９】
上記滑剤としては、内部滑剤、外部滑剤が挙げられる。上記内部滑剤とは、成形加工時の溶融樹脂の流動粘度を低下させ、摩擦発熱を防止する目的で使用されるものであり、具体的には、例えば、ブチルステアレート、ラウリルアルコール、ステアリルアルコール、エポキシ大豆油、グリセリンモノステアレート、ステアリン酸、ビスアミド等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００２０】
上記外部滑剤とは、成形加工時の溶融樹脂と金属面との滑り効果を上げる目的で使用されるものであり、具体的には、例えば、パラフィンワックス、ポリオレフィンワックス、エステルワックス、モンタン酸ワックス等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
上記滑剤の添加量は特に限定されず、本発明の目的を損なわない範囲であれば特に限定されない。
【００２１】
上記酸化防止剤としては特に限定されず、例えば、フェノール系抗酸化剤等が挙げられる。
上記光安定剤としては特に限定されず、例えば、ヒンダードアミン系等が挙げられる。
上記紫外線吸収剤としては特に限定されず、例えば、サリチル酸エステル系、ベンゾフェノン系、ベンゾトリアゾール系、シアノアクリレート系等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００２２】
上記帯電防止剤としては特に限定されず、例えば、カチオン系帯電防止剤、非イオン系帯電防止剤等が挙げられる。
【００２３】
上記顔料としては特に限定されず、例えば、アゾ系、フタロシアニン系、スレン系、染料レーキ系等の有機顔料、酸化物系、クロム酸モリブデン系、硫化物・セレン化物系、フェロシアニン化物系等の無機顔料等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００２４】
上記充填剤の種類や添加量としては特に限定されず、例えば、炭酸カルシウム、タルク等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００２５】
上記可塑剤としては特に限定されず、例えば、ジブチルフタレート、ジ−２―エチルヘキシルフタレート、ジ−２―エチルヘキシルアジペート等が挙げられる。これらは単独で用いてもよく、２種以上を併用してもよい。
【００２６】
上記した酸化防止剤、光安定剤、紫外線吸収剤、帯電防止剤、顔料、充填材、可塑剤の添加量は、本発明の塩化ビニル系樹脂組成物の特性を損なわない範囲内であれば特に限定されない。
【００２７】
上記ＣＰＶＣ組成物を成形する際に用いる成形機としては特に限定されず、例えば、単軸押出機、二軸異方向パラレル押出機、二軸異方向コニカル押出機、二軸同方向押出機等が挙げられる。又、賦形する金型、樹脂温度、成形条件は、特に限定されない。
【００２８】
【発明の実施の形態】
本発明をさらに詳しく説明するため以下に実施例を挙げるが、本発明はこれら実施例のみに限定されるものではない。
【００２９】
参考例１、３、７、８実施例４、６、比較例１〜３
〔ＰＶＣの調製〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、平均ケン化度８８モル％及び重合度１０００の部分ケン化ポリ酢酸ビニルを濃度が４００ｐｐｍ、ソルビタンモノラウレート（ＨＬＢ：８.６）濃度が１６００ｐｐｍ、ラウリン酸濃度が１５００ｐｐｍ、ポリアクリルアミド（２０℃、１０１３２５ＭＰａで０.１重量％水溶液のブルックフィールズ粘度が５１ｍＰａ・ｓ）濃度が１００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が９０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。
【００３０】
得られたＰＶＣについて下記の方法で構造分析を行い、結果を表１に示した。
〔評価方法〕
（ＥＳＣＡ分析）
ＰＶＣ粒子の表面をＥＳＣＡ（Electron Spectroscopy for Chemical Analysis：電子分光化学分析）で下記の条件でスキャンしＣ１ｓ（炭素）、Ｃｌ１ｓ（塩素）Ｏ１ｓ（酸素）の各ピーク面積より塩素量を基準に粒子表面の塩化ビニル樹脂成分を定量分析した。
・使用機器：日本電子社製「ＪＰＳ−９０ＦＸ」
・使用条件：Ｘ線源（ＭｇＫα線）、１２ｋＶ−１５ｍＡ
・スキャン速度：２００ｍｓ／０.１ｅＶ／ｓｃａｎ
・パスエネルギー：３０ｅＶ
（細孔分布）
水銀圧入ポロシメーターを用いて、１９６ＭＰａで塩素化塩化ビニル系樹脂１００ｇに圧入される水銀の容量測定して空隙率を求めた。空隙率とは樹脂粒子体積に占める空隙の割合である。細孔分布は、空隙率を測定するために０〜１９６ＭＰａまで圧力を上げるが、その際に水銀圧入量を連続的に測定し、細口径の分布を測定した。
【００３１】
〔ＣＰＶＣの調製〕
内容積３００Ｌのグラスライニング製耐圧反応層に、上記で得られたスラリー状のＰＶＣ２００ｋｇ（ＰＶＣ４０ｋｇと水性媒体１６０ｋｇとからなる）を投入し、その後、反応槽内を加温して槽内を１１０℃に保った。次いで、反応槽内に窒素ガスを吹き込み、槽内を窒素ガスで置換した後、反応槽内に塩素ガスを吹き込みＰＶＣの塩素化を行った。反応槽内の塩酸濃度を測定することにより塩素化反応の進行をモニターしながら塩素化反応を続け、生成したＣＰＶＣの塩素含有率が６６.４重量％に達した時点で塩素ガスの供給を停止し、塩素化反応を終了した。更に、反応槽内に窒素ガスを吹き込んで未反応塩素を除去し、得られた樹脂を水酸化ナトリウムで中和した後、水で洗浄し脱水、乾燥して粉末状のＣＰＶＣ（Ａ）を得た。得られたＣＰＶＣ（Ａ）の塩素含有率は６６.９重量％であった。
【００３２】
〔評価〕
（破断伸び保持率）
ＣＰＶＣ（Ａ）を用いて表２に従って添加剤を配合してＣＰＶＣ系組成物を得た。得られたＣＰＶＣ系組成物を２００℃の８インチロールミキサー（安田精機製：１９１−ＴＭ８×２０）で巻き付き後３分間混練し、得られたロールシートを、２０５℃のプレス成形機（東邦マシナリー製）で余熱２分、加圧（圧力：１９６ＭＰａ)２分でプレス成形し、厚さ約２ｍｍのプレス板を得た。プレス板から引張試験片（ＪＩＳＫ７１１３：２号試験片）を切削し、ＪＩＳＫ７１１３に準じ２３℃で破断伸び（Ｅｂ）を測定した（ｎ数＝５）。
一方、同様にして得られた引張試験片を外半径５ｃｍのＳＵＳ製パイプに引張試験片の長さ方向が円弧に曲がった状態で巻き付け、両端を固定した。この時引張試験片に発生する表面最大応力が１８.６〜１９.８ＭＰａとなるように、引張試験片の厚みを２ｍｍ±０.４ｍｍの範囲で調節した引張試験片を使用した。
なお表面最大応力は次式（２）により計算した。
表面最大応力(σ_max)＝(ヤング率×厚み)／(２×(外半径＋引張試験片厚)…（２）
引張試験片を固定したら直ちに５０℃の１４ｗｔ％ＫＯＨ水溶液の中に浸漬させ、密閉した容器内で７２時間放置した。取り出した引張試験片を水洗し、ＪＩＳＫ７１１３に準じ２３℃で破断伸び（Ｅａ）を測定した（ｎ数＝５）。
なお、各引張試験片の破断伸び保持率は式（１）により計算し、結果を表２に示した。
Ｅａ／Ｅｂ ×１００ … （１）
【００３３】
（耐アルカリ性）
他方で、表２に記載の配合組成物を、２００Ｌヘンシェルミキサー（カワタ製：２００Ｌスーパーミキサー）で混合し、この組成物を２軸異方向回転の押出機（積水工機製：ＳＬＭ６０）を用いてバレル温度１７０〜２００℃、金型温度１９５〜２１０℃、スクリュー回転１０〜２０ｒｐｍで成形し内径５０mm、肉厚４．５mmのパイプを得た。この時の樹脂温度は約２０５℃、押出量は約６０〜７５ｋｇ／ｈであった。得られたパイプにポンプで５０℃の１４ｗｔ％ＫＯＨ水溶液を１ヶ月間循環させ、下記の基準で耐アルカリ性の合否を判定した。結果を表２に示した。
○：アルカリの漏洩や、飛散がなく、管内面にＥＳＣが発生していない。
×：アルカリの漏洩や、飛散がみられる。または管内面にＥＳＣが発生している。
【００３４】
参考例２、実施例５
〔ＰＶＣの調整〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、平均ケン化度８８モル％及び重合度１０００の部分ケン化ポリ酢酸ビニルを濃度が１２００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が５０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。得られたＰＶＣにつき実施例１と同様の評価を行った、結果を表１に示した。
〔ＣＰＶＣの調製〕得られたＰＶＣを用いて実施例１と同様に行ってＣＰＶＣ（Ｂ）を得、実施例１と同様の評価を行った、結果を表２に示した。
【００３５】
比較例４
〔ＰＶＣの調整〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、平均ケン化度８８モル％及び重合度１０００の部分ケン化ポリ酢酸ビニルを濃度が６００ｐｐｍ、ソルビタンモノラウレート（ＨＬＢ：８.６）濃度が３０００ｐｐｍ、ラウリン酸濃度が２０００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が９０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。
得られたＰＶＣにつき実施例１と同様の評価を行った、結果を表１に示した。
〔ＣＰＶＣの調製〕
得られたＰＶＣを用いて実施例１と同様に行ってＣＰＶＣ（Ｃ１）を得、実施例１と同様の評価を行った、結果を表２に示した。
【００３６】
比較例５
〔ＰＶＣの調整〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、平均ケン化度８８モル％及び重合度１０００の部分ケン化ポリ酢酸ビニルを濃度が１３００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が５０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。得られたＰＶＣにつき実施例１と同様の評価を行った、結果を表１に示した。
〔ＣＰＶＣの調製〕
得られたＰＶＣを用いて実施例１と同様に行ってＣＰＶＣ（Ｃ２）を得、実施例１と同様の評価を行った、結果を表２に示した。
【００３７】
比較例６
〔ＰＶＣの調整〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、ソルビタンモノラウレート（ＨＬＢ：８.６）濃度が３０００ｐｐｍ、ラウリン酸濃度が２０００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が９０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。得られたＰＶＣにつき実施例１と同様の評価を行った、結果を表１に示した。
〔ＣＰＶＣの調製〕
得られたＰＶＣを用いて実施例１と同様に行ってＣＰＶＣ（Ｃ３）を得、実施例１と同様の評価を行った、結果を表２に示した。
【００３８】
比較例７
〔ＰＶＣの調整〕
内容積１００Ｌの重合器（耐圧オートクレーブ）に脱イオン水５０ｋｇを入れた後、塩化ビニル単量体に対して、平均ケン化度８８モル％及び重合度１０００の部分ケン化ポリ酢酸ビニルを濃度が１０００ｐｐｍ、ｔ−ブチルパーオキシネオデカノエートを濃度が５５０ｐｐｍとなる量を投入した。次いで、重合器内を４５ｍｍＨｇまで脱気した後、塩化ビニル単量体３３ｋｇを仕込み、撹拌を開始した。重合器を５６℃に昇温して重合を開始し、重合反応終了までこの温度を保った。重合転化率が５０％になった時点で反応を終了し、重合器内の未反応単量体を回収した後、重合体をスラリー状で系外へ取り出し、脱水乾燥してＰＶＣを得た。得られたＰＶＣの重合度は、１０５０であった。得られたＰＶＣにつき実施例１と同様の評価を行った、結果を表１に示した。
〔ＣＰＶＣの調製〕
得られたＰＶＣを用いて実施例１と同様に行ってＣＰＶＣ（Ｃ４）を得、実施例１と同様の評価を行った、結果を表２に示した。
【００３９】
【表１】

【００４０】
【表２】

【００４１】
【発明の効果】
本発明の塩素化塩化ビニル系樹脂組成物は、上述の構成からなるため、優れた耐アルカリ性を有するＰＶＣ成形品を得ることが可能である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vinyl chloride resin composition.
[0002]
[Prior art]
Vinyl chloride resin (hereinafter referred to as PVC) is superior in mechanical strength, weather resistance, and chemical resistance, and is inexpensive compared to other plastic materials, so it can be used in a wide range of fields such as water supply and drainage pipes, plates, and joints. Is a general-purpose resin used in However, since PVC has a low heat distortion temperature and a usable upper limit temperature of around 60 to 70 ° C., it is difficult to use PVC for hot water supply pipes and plant pipes through which hot water flows. Accordingly, in order to improve the durability performance of PVC at high temperatures, a chlorinated vinyl chloride resin (hereinafter referred to as CPVC) in which PVC is chlorinated to improve heat resistance has been developed. With this compounding design using resin, it has become possible to use pipes having both easy workability of PVC, easy adhesion, heat resistance, and impact resistance. (Japanese Patent Laid-Open No. 4-359928) As described above, pipes having no problems have been developed in hot water supply pipes and ultrapure water pipes for plants. On the other hand, in line pipes in the plant field where an alkaline aqueous solution flows. Even in the case of hard polyvinyl chloride pipes with excellent chemical resistance, environmental stress cracking progresses due to long-term use, and further cracks develop due to internal pressure, pulsation, stress generated at the support, and stress generated by expansion and contraction. (Hereinafter referred to as ESC) occurred, and there were cases in which tube breakage, rupture, or outflow of chemicals became a problem.
[0003]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide a vinyl chloride resin composition capable of obtaining a PVC molded article having excellent alkali resistance.
[0004]
[Means for Solving the Problems]
The chlorinated vinyl chloride resin composition of the present invention is a particle surface analysis by electron spectrochemical (ESCA) analysis.
The peak ratio of 1s bond energy value (eV) of carbon atom and chlorine atom exceeds 0.6, and the pore volume distribution by mercury intrusion method (pressure 0 to 196 MPa) is in the range of 0.001 to 0.1 μm. 100 parts by weight of chlorinated vinyl chloride resin obtained by chlorinating vinyl chloride resin having a void volume of 2 to 15% by volume in the total void volume,
A chlorinated vinyl chloride to which a vinyl chloride resin and a modifier are added, the modifier component is 4 parts by weight or more and less than 30 parts by weight, and the total of the vinyl chloride resin component and the modifier component is 10 parts by weight or more. A resin composition comprising:
The modifier component comprises a combination of a silicon acrylic modifier and a chlorinated polyethylene modifier,
A tensile test piece prepared in accordance with JIS K 7113 from the above resin composition is bent in an arc so that the maximum surface stress is 1.86 to 1.96 MPa. In addition, the breaking elongation retention calculated by the following formula (1) from the breaking elongation (Ea) after immersion for 72 hours at 50 ° C. and the breaking elongation (Eb) before immersion is 30% or more. Features.
Elongation at break (%) = Ea / Eb × 100 (1)
[0006]
The ESC of vinyl chloride resin molded products by alkali is a phenomenon that occurs when the vinyl chloride resin composition is deteriorated by the alkali in contact with it and when stress is generated in the vinyl chloride molded product. However, the phenomenon of ESC does not occur.
[0007]
The inventor of the present application conducted a sincere examination based on the above findings, and as a result, the tensile test piece (JIS K7113: No. 2 test piece) was bent in a circular arc so that the maximum surface stress was 18.6 to 19.8 MPa. From the elongation at break (Ea) after immersion for 72 hours at 50 ° C. in a 14 wt% KOH aqueous solution and the elongation at break (Eb) before immersion, the elongation at break (%) calculated by equation (1) is When it was 30 or more, it was clarified that ESC hardly occurs even when using alkali.
This is because the chlorinated vinyl chloride resin composition having a breaking elongation retention rate of 30% or more is less likely to cause deterioration of the material due to alkali, or the stress generated in the initial stage is easily relaxed. As a result, it is considered that minute ESC generated on the surface of the molded product is suppressed, and a decrease in elongation at break is suppressed.
[0008]
If the breaking elongation retention ratio is less than 30, ESC is generated under normal use conditions and gradually grows. If used for a long time, there is a high possibility of causing damage to the molded product or leakage of chemicals. The rate is limited to 30 or more, more preferably 60 or more.
[0009]
The vinyl chloride resin (PVC resin) is a vinyl chloride monomer (hereinafter referred to as VCM) alone or a mixture of VCM and other monomers copolymerizable with VCM by a known method (for example, suspension). Polymerization, bulk polymerization, etc.). The other monomer copolymerizable with the VCM is not particularly limited, and examples thereof include alkyl vinyl esters such as vinyl acetate, α-monoolefins such as ethylene and propylene, vinylidene chloride, and styrene. These may be used alone or in combination of two or more.
[0010]
The PVC resin has a peak ratio of 1s bond energy value (eV) of carbon atom and chlorine atom exceeding 0.6 in the surface portion by electron spectrochemical (ESCA) analysis. When the peak ratio in the 1s bond energy value (eV) between the carbon atom and the chlorine atom is 0.6 or less, it is considered that an additive such as a dispersant is adsorbed on the surface of the PVC particles. Not only is the speed slowed, but the resulting CPVC is difficult to be uniformly kneaded, which is not preferable for chemical resistance. Moreover, thermal stability becomes inferior. More preferably, the peak ratio exceeds 0.7. The abundance ratio of chlorine atom to carbon atom in the PVC is chlorine atom / carbon atom = 1/2 (when the terminal structure and branching are not taken into consideration), and the peak at the 1s bond energy value (eV). The ratio (chlorine atom peak × 2 / carbon atom peak) is a value between 0 and 1. When the peak ratio is 0, it means that the surface of the PVC particles is covered with another substance other than PVC and does not contain chlorine. When the peak ratio is 1, the surface of the PVC particles is completely It means that it is covered only with the vinyl chloride component.
[0011]
The pore distribution of the PVC is the void volume ratio in which the void volume in the range of 0.001 to 0.1 μm accounts for the total void volume in the measured pore volume distribution by the mercury intrusion method (measurement pressure range is 0 to 196 MPa). Is 2-15% by volume. When the void volume ratio is less than 2% by volume, the proportion of fine pores inside the particles is small, the gelation property at the time of molding is inferior, and the chemical resistance is not preferable. The diffusion of chlorine during conversion is not performed in a well-balanced manner, and the chlorine content distribution in the particles becomes too wide, resulting in poor thermal stability. A more preferable volume fraction is 2 to 15% by volume.
[0012]
The CPVC resin of the present invention may be a resin obtained by chlorinating the PVC resin, and the degree of chlorination is not particularly limited. Two or more types of CPVC may be used in combination.
It does not specifically limit as a method to chlorinate PVC, It can carry out by various conventionally well-known methods. For example, it can be performed by bringing the PVC into a suspended state, a state dissolved in a solvent, or a solid state, and then contacting with chlorine.
[0013]
The chlorinated vinyl chloride resin composition comprises the chlorinated vinyl chloride resin, a modifier, and a vinyl chloride resin. The modifier is a combination of a silicon acrylic modifier and a chlorinated polyethylene (CPE) modifier. This combination is preferable in terms of alkali resistance. These may be used alone or in combination of two or more. The amount of the modifier added is 4 parts by weight or more with respect to 100 parts by weight of the chlorinated vinyl chloride resin. When the amount is less than 4 parts by weight, sufficient alkali resistance cannot be obtained. The total of the vinyl chloride resin component and the modifier component is 10 parts by weight or more. When the amount is less than 10 parts by weight, the alkali resistance may be unfavorably lowered, and more preferably 13 parts by weight or more. On the other hand, if there are too many modifiers, the deterioration of the modifier components due to alkali and compatibility with the chlorinated vinyl chloride resin may be reduced, and the impact resistance may be reduced. The amount is less than 30 parts by weight based on 100 parts by weight of the chlorinated vinyl chloride resin.
[0014]
The CPVC-based resin composition includes a stabilizer, a processing aid, a lubricant, an antioxidant, a light stabilizer, an ultraviolet absorber, an antistatic agent, a pigment, a filler, a plasticizer, and the like. You may mix | blend the compounding agent currently used at the time of shaping | molding as needed in the range which does not impair the objective of this invention.
[0015]
The stabilizer is not particularly limited, and examples thereof include a heat stabilizer and a heat stabilization aid. Examples of the heat stabilizer include organic tin stabilizers such as dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, calcium-zinc stabilizer, barium-zinc stabilizer, barium-cadmium stabilizer, stearin. Examples thereof include lead-based stabilizers such as lead acid. These may be used alone or in combination of two or more.
[0016]
Moreover, it does not specifically limit as said heat stabilization adjuvant, For example, epoxidized soybean oil, phosphate ester, etc. are mentioned. These may be used alone or in combination of two or more.
[0017]
The addition amount of the stabilizer and the stabilizing aid is not particularly limited as long as the object of the present invention is not impaired.
[0018]
The processing aid is not particularly limited, and examples thereof include acrylic processing aids such as alkyl acrylate / alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. Specific examples include n-butyl acrylate / methyl methacrylate copolymer, 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer, and the like. These may be used alone or in combination of two or more. The amount of the processing aid added is not particularly limited as long as the object of the present invention is not impaired.
[0019]
Examples of the lubricant include an internal lubricant and an external lubricant. The internal lubricant is used for the purpose of reducing the flow viscosity of the molten resin during molding and preventing frictional heat generation. Specifically, for example, butyl stearate, lauryl alcohol, stearyl alcohol, Examples include epoxy soybean oil, glycerin monostearate, stearic acid, bisamide and the like. These may be used alone or in combination of two or more.
[0020]
The external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during molding. Specifically, for example, paraffin wax, polyolefin wax, ester wax, montanic acid wax, etc. Is mentioned. These may be used alone or in combination of two or more.
The addition amount of the said lubricant is not specifically limited, If it is a range which does not impair the objective of this invention, it will not specifically limit.
[0021]
It does not specifically limit as said antioxidant, For example, a phenolic antioxidant etc. are mentioned.
The light stabilizer is not particularly limited, and examples thereof include hindered amines.
The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based. These may be used alone or in combination of two or more.
[0022]
The antistatic agent is not particularly limited, and examples thereof include a cationic antistatic agent and a nonionic antistatic agent.
[0023]
The pigment is not particularly limited, and examples thereof include organic pigments such as azo, phthalocyanine, selenium, and dye lakes, oxides, molybdenum chromate, sulfides / selenides, ferrocyanides, and the like. An inorganic pigment etc. are mentioned. These may be used alone or in combination of two or more.
[0024]
The type and amount of the filler are not particularly limited, and examples thereof include calcium carbonate and talc. These may be used alone or in combination of two or more.
[0025]
The plasticizer is not particularly limited, and examples thereof include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. These may be used alone or in combination of two or more.
[0026]
The addition amount of the above-mentioned antioxidant, light stabilizer, ultraviolet absorber, antistatic agent, pigment, filler, plasticizer is particularly within the range that does not impair the properties of the vinyl chloride resin composition of the present invention. It is not limited.
[0027]
The molding machine used when molding the CPVC composition is not particularly limited, and examples thereof include a single screw extruder, a biaxial different direction parallel extruder, a biaxial different direction conical extruder, a biaxial codirectional extruder, and the like. Can be mentioned. Moreover, the shaping | molding metal mold | die, resin temperature, and molding conditions are not specifically limited.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to these examples.
[0029]
Reference Examples 1, 3 , 7, 8 Examples 4, 6, Comparative Examples 1-3
[Preparation of PVC]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) with an internal volume of 100 L, the concentration of partially saponified polyvinyl acetate having an average saponification degree of 88 mol% and a polymerization degree of 1000 with respect to the vinyl chloride monomer 400 ppm, sorbitan monolaurate (HLB: 8.6) concentration is 1600 ppm, lauric acid concentration is 1500 ppm, polyacrylamide (Brookfields viscosity of 0.1 wt% aqueous solution at 20 ° C., 101325 MPa is 51 mPa · s) concentration is 100 ppm, An amount of t-butyl peroxyneodecanoate in a concentration of 550 ppm was added. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 90%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050.
[0030]
The obtained PVC was subjected to structural analysis by the following method, and the results are shown in Table 1.
〔Evaluation methods〕
(ESCA analysis)
The surface of the PVC particle is scanned by ESCA (Electron Spectroscopy for Chemical Analysis) under the following conditions, and the particle surface is based on the amount of chlorine from each peak area of C1s (carbon), Cl1s (chlorine) O1s (oxygen). The vinyl chloride resin component was quantitatively analyzed.
・ Equipment: “JPS-90FX” manufactured by JEOL Ltd.
・ Use conditions: X-ray source (MgKα ray), 12 kV-15 mA
Scan speed: 200 ms / 0.1 eV / scan
・ Pass energy: 30eV
(Pore distribution)
Using a mercury intrusion porosimeter, the volume of mercury injected into 100 g of chlorinated vinyl chloride resin at 196 MPa was measured to determine the porosity. The porosity is the ratio of voids to the resin particle volume. In order to measure the porosity, the pore distribution was increased from 0 to 196 MPa. At that time, the amount of mercury intrusion was continuously measured, and the distribution of the narrow diameter was measured.
[0031]
[Preparation of CPVC]
200 kg of the slurry-like PVC obtained above (consisting of 40 kg of PVC and 160 kg of aqueous medium) is charged into a 300-liter glass-lined pressure-resistant reaction layer, and the inside of the reaction tank is heated to 110 ° C. Kept. Next, nitrogen gas was blown into the reaction tank, the inside of the tank was replaced with nitrogen gas, and then chlorine gas was blown into the reaction tank to chlorinate PVC. The chlorination reaction was continued while monitoring the progress of the chlorination reaction by measuring the hydrochloric acid concentration in the reaction tank, and the chlorine gas supply was stopped when the chlorine content of the produced CPVC reached 66.4% by weight. The chlorination reaction was completed. Further, nitrogen gas was blown into the reaction vessel to remove unreacted chlorine, and the resulting resin was neutralized with sodium hydroxide, washed with water, dehydrated and dried to obtain powdery CPVC (A). It was. The CPVC (A) obtained had a chlorine content of 66.9% by weight.
[0032]
[Evaluation]
(Elongation at break)
An additive was blended according to Table 2 using CPVC (A) to obtain a CPVC composition. The obtained CPVC composition was wound around a 200 ° C. 8-inch roll mixer (Yasuda Seiki: 191-TM8 × 20) and kneaded for 3 minutes, and the resulting roll sheet was transferred to a 205 ° C. press molding machine (Toho Machinery). Manufactured) and press-molded with a remaining heat of 2 minutes and a pressure (pressure: 196 MPa) of 2 minutes to obtain a press plate having a thickness of about 2 mm. A tensile test piece (JIS K 7113: No. 2 test piece) was cut from the press plate, and elongation at break (Eb) was measured at 23 ° C. according to JIS K 7113 (n number = 5).
On the other hand, a tensile test piece obtained in the same manner was wound around a SUS pipe having an outer radius of 5 cm in a state where the length direction of the tensile test piece was bent in an arc, and both ends were fixed. At this time, a tensile test piece in which the thickness of the tensile test piece was adjusted in a range of 2 mm ± 0.4 mm was used so that the maximum surface stress generated in the tensile test piece was 18.6 to 19.8 MPa.
The surface maximum stress was calculated by the following equation (2).
Maximum surface stress (σ _max ) = (Young's modulus × thickness) / (2 × (outer radius + tensile specimen thickness) (2)
Immediately after fixing the tensile test piece, it was immersed in a 14 wt% KOH aqueous solution at 50 ° C. and left in a sealed container for 72 hours. The taken tensile test piece was washed with water, and the elongation at break (Ea) was measured at 23 ° C. according to JIS K 7113 (n number = 5).
In addition, the breaking elongation retention of each tensile test piece was calculated by the formula (1), and the results are shown in Table 2.
Ea / Eb × 100 (1)
[0033]
(Alkali resistance)
On the other hand, the compounding composition shown in Table 2 was mixed with a 200 L Henschel mixer (Kawata: 200 L Super Mixer), and this composition was mixed using a biaxially rotating extruder (Sekisui Koki Co., Ltd .: SLM60). A pipe having an inner diameter of 50 mm and a wall thickness of 4.5 mm was obtained by molding at a barrel temperature of 170 to 200 ° C., a mold temperature of 195 to 210 ° C., and a screw rotation of 10 to 20 rpm. At this time, the resin temperature was about 205 ° C., and the extrusion rate was about 60 to 75 kg / h. A 14 wt% KOH aqueous solution at 50 ° C. was circulated through the obtained pipe for 1 month with a pump, and the pass / fail of the alkali resistance was determined according to the following criteria. The results are shown in Table 2.
○: There is no alkali leakage or scattering, and no ESC is generated on the inner surface of the tube.
×: Alkali leakage and scattering are observed. Alternatively, ESC is generated on the inner surface of the tube.
[0034]
Reference Example 2 and Example 5
[PVC adjustment]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) with an internal volume of 100 L, the concentration of partially saponified polyvinyl acetate having an average saponification degree of 88 mol% and a polymerization degree of 1000 with respect to the vinyl chloride monomer 1200 ppm, t-butyl peroxyneodecanoate was added in an amount of 550 ppm. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 50%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050. The obtained PVC was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
[Preparation of CPVC] Using the obtained PVC, CPVC (B) was obtained in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
[0035]
Comparative Example 4
[PVC adjustment]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) with an internal volume of 100 L, the concentration of partially saponified polyvinyl acetate having an average saponification degree of 88 mol% and a polymerization degree of 1000 with respect to the vinyl chloride monomer 600 ppm, sorbitan monolaurate (HLB: 8.6) concentration of 3000 ppm, lauric acid concentration of 2000 ppm, and t-butylperoxyneodecanoate in an amount of 550 ppm were added. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 90%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050.
The obtained PVC was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
[Preparation of CPVC]
The obtained PVC was used in the same manner as in Example 1 to obtain CPVC (C1), and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
[0036]
Comparative Example 5
[PVC adjustment]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) with an internal volume of 100 L, the concentration of partially saponified polyvinyl acetate having an average saponification degree of 88 mol% and a polymerization degree of 1000 with respect to the vinyl chloride monomer 1300 ppm, t-butyl peroxyneodecanoate was added in an amount of 550 ppm. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 50%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050. The obtained PVC was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
[Preparation of CPVC]
The obtained PVC was used in the same manner as in Example 1 to obtain CPVC (C2), and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
[0037]
Comparative Example 6
[PVC adjustment]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) having an internal volume of 100 L, the concentration of sorbitan monolaurate (HLB: 8.6) is 3000 ppm, the concentration of lauric acid is 2000 ppm with respect to the vinyl chloride monomer, An amount of t-butyl peroxyneodecanoate in a concentration of 550 ppm was added. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 90%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050. The obtained PVC was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
[Preparation of CPVC]
The obtained PVC was used in the same manner as in Example 1 to obtain CPVC (C3), and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
[0038]
Comparative Example 7
[PVC adjustment]
After putting 50 kg of deionized water into a polymerization vessel (pressure autoclave) with an internal volume of 100 L, the concentration of partially saponified polyvinyl acetate having an average saponification degree of 88 mol% and a polymerization degree of 1000 with respect to the vinyl chloride monomer An amount of 1000 ppm and t-butyl peroxyneodecanoate in a concentration of 550 ppm was added. Next, after degassing the inside of the polymerization vessel to 45 mmHg, 33 kg of vinyl chloride monomer was charged and stirring was started. The polymerization was started by raising the temperature of the polymerization vessel to 56 ° C., and this temperature was maintained until the polymerization reaction was completed. The reaction was terminated when the polymerization conversion rate reached 50%, and the unreacted monomer in the polymerization vessel was recovered. Then, the polymer was taken out of the system in a slurry state and dehydrated and dried to obtain PVC. The degree of polymerization of the obtained PVC was 1050. The obtained PVC was evaluated in the same manner as in Example 1, and the results are shown in Table 1.
[Preparation of CPVC]
The obtained PVC was used in the same manner as in Example 1 to obtain CPVC (C4), and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
[0039]
[Table 1]

[0040]
[Table 2]

[0041]
【The invention's effect】
Since the chlorinated vinyl chloride resin composition of the present invention has the above-described configuration, it is possible to obtain a PVC molded product having excellent alkali resistance.

Claims

In particle surface analysis by electron spectrochemical (ESCA) analysis,
The peak ratio of 1s bond energy value (eV) of carbon atom and chlorine atom exceeds 0.6, and in the pore volume distribution by mercury intrusion method (pressure 0 to 196 MPa), the range is 0.001 to 0.1 μm. 100 parts by weight of chlorinated vinyl chloride resin obtained by chlorinating vinyl chloride resin having a void volume of 2 to 15% by volume in the total void volume,
A chlorinated vinyl chloride to which a vinyl chloride resin and a modifier are added, the modifier component is 4 parts by weight or more and less than 30 parts by weight, and the total of the vinyl chloride resin component and the modifier component is 10 parts by weight or more. A resin composition comprising:
The modifier component comprises a combination of a silicon acrylic modifier and a chlorinated polyethylene modifier,
A tensile test piece prepared from the above resin composition according to JIS K 7113 is bent in an arc so that the maximum surface stress is 1.86 to 1.96 MPa. In addition, the breaking elongation retention calculated by the following formula (1) from the breaking elongation (Ea) after immersion for 72 hours at 50 ° C. and the breaking elongation (Eb) before immersion is 30% or more. A characteristic chlorinated vinyl chloride resin composition.
Elongation at break (%) = Ea / Eb × 100 (1)