JP4556296B2

JP4556296B2 - Silane-attached paper container and method for producing the same

Info

Publication number: JP4556296B2
Application number: JP2000193588A
Authority: JP
Inventors: 純一神永; 敦子西野; 龍吉松尾
Original assignee: Toppan Inc
Current assignee: Toppan Inc
Priority date: 2000-06-27
Filing date: 2000-06-27
Publication date: 2010-10-06
Anticipated expiration: 2020-06-27
Also published as: JP2002002650A

Description

【０００１】
【発明の属する技術分野】
本発明は、天然素材であるパルプに対して、シラン化合物を均一に含有せしめることにより得られる、強度、耐水性、表面平滑性、ガスバリア性に優れた紙容器に関するもので、その形状にも自由度の高い、紙容器に関するものである。
【０００２】
【従来の技術】
従来、プラスチック容器は、耐水性、ガスバリア性に優れるとともに、その成形のしやすさから、広く普及している。しかし、一部のプラスチック容器から環境ホルモン（内分泌攪乱物質）の溶出等が報告され、紙容器への切り替えの動きが高まってきている。それに伴い紙容器に対して、高強度、耐水性、ガスバリア性等の要求も高くなってきている。
【０００３】
オルガノシランに代表されるシラン化合物は、耐熱、耐水強度が高く、またアルカリで加水分解されることから、紙の離解性を損なわない等の理由により、強度、耐水性向上、また寸法安定性、耐摩擦性向上などの目的で、紙、或いはパルプモールド容器に対して、シラン化合物処理の試みがなされている。その手法の多くは、複数種のオルガノシラン化合物と加水分解触媒とを有機溶剤に溶かし、これを紙或いはパルプモールドにコーティングする方法であるため、後加工工程を必要とし、特にパルプモールドのような三次元成形体への処理は極めて効率の悪いものとなっている。また、塗工表面へのシラン化合物の偏析が大きく、全層にわたって均一にシラン化合物を分散させることはできないため、紙容器の端面の耐水性等の物性に不十分な点があった。
【０００４】
特開平１０−２１２６９３、特開平１０−２２６８９０では、製紙用の内添薬剤としてパルプスラリー中へオルガノシラン化合物を添加する方法が提案されている。本方法はパルプスラリー中への内添処理だけで、後加工工程を必要とせず、また添加薬剤は紙の中で均一に分布する。しかしながらシラン系以外の一般的な製紙用内添薬剤同様、その定着率がパルプ乾燥重量の１％程度（ＳｉＯ₂重量換算）にとどまり、強度や耐水性の向上にも限界があった。
一方、従来の一般的な湿潤紙力増強剤は架橋反応性分として塩素を含んでいたり、ホルムアルデヒドが発生したりと、環境に負荷の大きいことが危惧されている。
【０００５】
さらに、紙自体はパルプ繊維が寄り集まったポーラスな構造体であり、ガスバリア性は全くなく、容器として内容物保護のためガスバリア性が必要とする場合は、プラスチック等との複合化を余儀なくされていた。
【０００６】
【発明が解決しようとする課題】
本発明は、セルロースの生分解性、紙としてのリサイクル性を損なわず、天然素材であるパルプに対して、内添時のｐＨ調整や、定着剤等の併用なく、シラン化合物を高濃度で均一に含有せしめたパルプ材からなる紙容器であり、プラスチックとの複合化することなく、強度、耐水性、表面平滑性、ガスバリア性に優れた紙容器を提供することを課題とする。
【０００７】
【課題を解決するための手段】
請求項１に記載の発明は、植物繊維、または植物繊維の集合体であるパルプ材を主成分とするシラン内添紙容器であって、前記パルプ材が、シラン化合物を主成分とする内添剤のパルプスラリーへの添加によって調製されたパルプ材であり、前記シラン化合物が、Ｒ ^３ _ｎＳｉ（ＯＲ ^４） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^３は１〜１０個の炭素主鎖１種以上で構成されエポキシ基をその構造中に含む、Ｒ ^２は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物１種以上と、Ｒ ^５ _ｎＳｉ（ＯＲ ^６） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^５は１〜１０個の炭素主鎖よりなり、炭素主鎖間または末端のいずれか１方もしくは双方にアミノ基を有する、Ｒ ^６は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物を含み、前記シラン化合物が、パルプ乾燥重量に対してＳｉＯ_２換算値で２〜２０％含まれることを特徴とするシラン内添紙容器である。
【０００８】
請求項２に記載の発明は、パルプを構成する繊維が、木材原料または靭皮繊維、種毛繊維、葉の繊維、草類繊維などの天然素材のいずれかを主成分とする請求項１記載のシラン内添紙容器。
【０００９】
請求項３に記載の発明は、請求項１に記載した、Ｒ ^３ _ｎＳｉ（ＯＲ ^４） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^３は１〜１０個の炭素主鎖１種以上で構成されエポキシ基をその構造中に含む、Ｒ ^２は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物１種以上と、Ｒ ^５ _ｎＳｉ（ＯＲ ^６） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^５は１〜１０個の炭素主鎖よりなり、炭素主鎖間または末端のいずれか１方もしくは双方にアミノ基を有する、Ｒ ^６は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物の混合モル比が５／５〜９．９９／０．０１である請求項１又は２記載のシラン内添紙容器である。
【００１０】
請求項４に記載の発明は、請求項１から３のいずれかに記載したシラン内添紙容器の内面或いは外面、また或いは両面に水溶性高分子と無機層状鉱物からなる混合液をコーティングしたことを特徴とするシラン内添紙容器である。
【００１１】
請求項５に記載の発明は、請求項１から４のいずれかに記載したシラン内添紙容器の内面或いは外面、また或いは両面にプラズマ重合による薄膜が形成されていることを特徴とするシラン内添紙容器である。
【００１２】
請求項６に記載の発明は、請求項１から５のいずれかに記載したシラン内添紙容器のガスバリア性が、１気圧下、１日当たりのｍ２換算した酸素透過度が１０ｃｃ／ｍ ^２／ｄａｙ以下、水蒸気透過度が３０ｇ／ｍ ^２／ｄａｙ以下であることを特徴とするシラン内添紙容器である。
【００１３】
請求項７に記載の発明は、植物繊維、または植物繊維の集合体であるパルプを主成分とするシラン内添紙容器の製造方法であって、シラン化合物をｐＨ７〜１４の条件下で水を含む溶媒と混合して内添剤を調製する工程と、前記内添剤をパルプスラリーへ添加してパルプ材を調製する工程と、前記パルプ材から湿式のパルプモールド成形法によりシラン内添紙容器を形成する工程又は前記パルプ材を抄紙し、得られたシラン内添紙を容器成形手法によりシラン内添紙容器を形成する工程とを備え、前記シラン化合物が、Ｒ ^３ _ｎＳｉ（ＯＲ ^４） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^３は１〜１０個の炭素主鎖１種以上で構成されエポキシ基をその構造中に含む、Ｒ ^２は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物１種以上と、Ｒ ^５ _ｎＳｉ（ＯＲ ^６） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^５は１〜１０個の炭素主鎖よりなり、炭素主鎖間または末端のいずれか１方もしくは双方にアミノ基を有する、Ｒ ^６は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物を含むことを特徴とするシラン内添紙容器の製造方法である。
【００１４】
請求項８に記載の発明は、請求項７に記載した、Ｒ ^３ _ｎＳｉ（ＯＲ ^４） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^３は１〜１０個の炭素主鎖１種以上で構成されエポキシ基をその構造中に含む、Ｒ ^２は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物１種以上と、Ｒ ^５ _ｎＳｉ（ＯＲ ^６） _ｍ（ＯＨ） _{４−ｍ−ｎ} （ｎ＝０，１，２，３のいずれか、０≦ｎ＋ｍ≦４、ｍは整数、Ｒ ^５は１〜１０個の炭素主鎖よりなり、炭素主鎖間または末端のいずれか１方もしくは双方にアミノ基を有する、Ｒ ^６は炭素数１から３の炭化水素）であらわされるオルガノシラン化合物の混合モル比が５／５〜９．９９／０．０１である請求項７記載のシラン内添紙容器の製造方法である。
【００１５】
請求項９に記載の発明は、請求項８に記載した内添剤のＳｉＯ _２固形分濃度が０．０１％以上５％以下である内添剤で、樹脂分を含めた全固形分濃度が２．５％以上４０％以下である内添剤を内添したパルプ材からなることを特徴とする請求項７又は８記載のシラン内添紙容器の製造方法である。
【００１８】
【発明の実施の形態】
以下、本発明を詳細に説明する。
本発明の紙容器の特徴は、シラン化合物を従来の抄紙スラリー中で添加でき、シラン化合物を多く紙中に保持させることが出来、容器として強度、耐水性、ガスバリア性に優れることである。
【００１９】
紙或いはパルプモールドの原料として用いられる材料は、繊維の絡み合いを利用して抄造でき、シート或いは成形体にすることが出来るものであれば何でも可能であるが、環境保護の観点から、人造繊維よりは天然繊維を用いることが望ましい。現在サトウキビやコーヒーなど、さまざまな天然物が紙の原料として用いられているが、これらを利用することも可能である。
【００２０】
内添剤原料となるシラン化合物は、オルガノシランを利用すると種類も豊富であり工業的にも入手しやすい。これをｐＨ７〜１４、望ましくは８〜１３の塩基性条件下で加水分解・重合を進めることで内添液が作製できる。ｐＨ調整は内添剤調製時に必要なだけで、内添時のパルプスラリーのｐＨ調整は不要である。
【００２１】
とくに、効果的な定着と機能発現のためにはアミン系オルガノシランを併用することが望ましい。このときアミンの種類は１級アミン、２級アミンのいずれでもよい。このオルガノシランは内添剤のセルロースへの定着を進める働きをしていると考えらる。アミン系シランカップリング剤は、他のオルガノシラン化合物を加水分解する触媒作用と、パルプへ定着する際のトリガーとしての役割の両方を担っていると推定している。とくに塩基性触媒としての触媒効果が大きいため、他の触媒の添加を必要としない。
【００２２】
エポキシ基を構造中にもつシランカップリング剤も、本手法において有効である。とくにシクロヘキシルエポキシ基を有するものの併用効果が高いが、その作用機構は明らかではない。アミンはエポキシの樹脂化触媒であるが、本溶媒中、また、混合するだけの条件下では両者による架橋構造が起こるとは考えにくい。両者を併用した場合、おのおののシラノール基による両者の複合化が進んでいると考えられるが、エポキシ基の立体障害等の影響で、シロキサン結合が効率的に進行するためではないかと推定している。
【００２３】
アミン系オルガノシランは、内添剤を構成するシランカップリング剤材料のうちの０．０１〜５０ｍｏｌ％（ＳｉＯ₂換算値）の範囲，望ましくは０．０１〜４０ｍｏｌ％であることが望ましい。この範囲であれば、耐水性、撥水性、表面平滑性の向上が期待できる。アミンの比率がこれよりも増えると撥水性は得にくくなる。これは内添剤中には親水基であるアミノ基が過剰となるためと考えている。なお、請求項記載のＲ¹は１１個以上だと加水分解が十分に行えない。また、Ｒ²が４以上では、アルコキシシランのアルコール分が抜けなくなる。
【００２４】
これら内添剤原料は，イソプロピルアルコール（ＩＰＡ）などのアルコール系溶媒中で室温条件下で穏やかに混合する。このときの溶媒は成分の均一化を図るためで，アルコールに限定されるものではない．本内添剤調製に当たっての混合は，およそ１時間から最大で２０時間程度，室温条件で穏やかに混合するだけであり，極めて容易である。この混合時にオルガノシランの加水分解と適度な複合化が進められる。オルガノシラン化合物の加水分解の際には酸、またはアルカリが触媒として添加されるが、本処方ではアミン系オルガノシラン化合物が触媒としての役割も果たすために添加の必要はない。そのため、酸やアルカリを触媒として添加した場合よりも液の安定性に優れている。
【００２５】
また、内添剤のＳｉＯ₂固形分濃度かうすいとアルコール成分が多くなり、このアルコール成分の多さにより製紙時取り扱いが不便となる欠点があり、０．０１％以上が好ましい。対して、全固形分濃度が１０％以上と多くなると、ゲル化し、使用できない。５％以上だと使用できても取り扱いが不便である。樹脂分を含めた全固形分濃度が２．５％以下だと、同様に製紙時の取り扱いが不便であり、４０％以上だと同様にゲル化し、使用できなくなる。さらに、紙のサイズ度が２０秒以下であると、水のしみ込み度が大きくなり、十分な耐水特性を有する紙容器とはならない。
【００２６】
オルガノシランの置換基が比較的小さかったり、アルコキシ基が加水分解を受けやすいような材料であれば１時間〜数時間の混合で十分に加水分解，複合化が進行する。
【００２７】
混合調製後の内添剤は、パルプスラリーへの添加のしやすさなどを考慮して、必要に応じて希釈して、パルプスラリーへの添加を行う。希釈はアルコール／水混合液が最適で、アルコールの種類は問わない。白水中へのアルコール混入を限りなく押さえるためには希釈率をさげることもできるし、水の配分を増やすこともできる。
【００２８】
本処方でパルプスラリーへ薬剤の添加を行った場合、定着率（歩留まり）は７０〜９９％であり、かつパルプ乾燥重量に対してＳｉＯ₂換算で２０％以上定着させることが出来るため、求める物性に応じて所定濃度の薬剤添加を行う。歩留まりが高いため、添加量の調整は容易で、求める紙物性に従い添加量を調整する。
添加にあたってのスラリーｐＨ調製はアミン系オルガノシラン混合物の混合比にかかわらず不要である。
【００２９】
薬剤の添加を行った後は通常の工程に従い抄紙、或いは湿式のパルプモールド成形を行う。シラン内添紙に関しては、従来の容器成形手法により容器成形され、またパルプモールドに関しては、その成形工程のみで、本発明による強度、耐水性、表面平滑性などに優れたシラン内添紙容器を得ることが出来る。
【００３０】
さらに本発明のシラン内添紙容器は、表面が平滑で、透気度が高く緻密であることから、容器表面に水溶性高分子と無機層状鉱物からなる混合液をコーティングしたり、プラズマ重合による薄膜を形成すると、ピンホール等の欠陥のないバリア膜が形成され、プラスチックとの複合化することなく、バリア性に優れた紙容器となる。
【００３１】
この際、水溶性高分子としてはポリビニルアルコール系樹脂、無機層状鉱物としてはモモンリロナイトが特に好ましく、プラズマ重合により形成される薄膜は有機シリカ系のものが特に好ましい。但しこれらに限定されるものではない。またバリア層となるコーティング膜やプラズマ重合薄膜を形成する際、目止め層や、オーバーコート層を設けても構わない。
【００３２】
＜作用＞
内添剤原料は、内添剤調製の攪拌時にＳｉ−Ｏ−Ｓｉ結合を介して適度に複合化され、構造中に親水性の官能基であるシラノール、アミノの両基をもつシリカゾルが生成していると推定している。このゾル中のアミノ基とパルプ中のカルボキシル基との相互作用、およびパルプのフィルター効果により、ゾルがパルプにからみつき定着が起こると推定される。さらに抄紙時の熱乾燥により、未反応シラノールのシロキサン結合形成が進み、紙中に３次元架橋構造が作られてパルプ間結合を補強すると考えられる。親水性のアミノ基はパルプ内部へ配向していると考えられ、そのためアミノ基以外の有機官能基はパルプ表面へ配向して撥水性、表面平滑性などの特性値を向上させるのに寄与していると予想される。
【００３３】
このシラン内添パルプ材より得られた本発明のシラン内添紙容器は、特に表面が平滑で、透気度が高く緻密であるために、その表面への膜形成に適しており、ピンホール等の欠陥のない安定したバリア膜を形成しやすい。容器表面に水溶性高分子と無機層状鉱物からなる混合液をコーティングしたり、プラズマ重合による薄膜を形成すると、１気圧下、１日当たりのｍ^２換算した酸素透過度が１０ｃｃ／ｍ^２／ｄａｙ以下、水蒸気透過度が３０ｇ／ｍ^２／ｄａｙ以下と高いガスバリア性が得られ、プラスチックとの複合化すること無く、内容物の保護に十分なガスバリア性が得られる。
【００３４】
【実施例】
以下に実施例をあげて、本発明を詳細に説明する。
＜内添剤調製例１＞
Ｎ−（２−アミノエチル）−３−アミノプロピルトリメトキシシラン（チッソ製サイラーエースＳ３２０）４．５ｇ（０．０２ｍｏｌ）、２−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン（チッソ製サイラーエースＳ５３０）７．４ｇ（０．０３ｍｏｌ）、イソプロピルアルコール１３．５ｇ（０．２２５ｍｏｌ）、水１３．５ｇ（０．７５ｍｏｌ）を１８時間室温で混合した。これをイソプロピルアルコールで希釈してＳｉＯ₂濃度１％となる内添液を調製した。
【００３５】
＜内添剤調製例２＞
Ｎ−（２−アミノエチル）−３−アミノプロピルトリメトキシシラン（チッソ製サイラーエースＳ３２０）１．１ｇ（０．００５ｍｏｌ）、２−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン（チッソ製サイラーエースＳ５３０）１１．１ｇ（０．０４５ｍｏｌ）、イソプロピルアルコール１３．５ｇ（０．２２５ｍｏｌ）、水１３．５ｇ（０．７５ｍｏｌ）を１８時間室温で混合した。これを水／イソプロピルアルコール＝１／１溶液でＳｉＯ₂濃度０．５％まで希釈後、さらに水で希釈してＳｉＯ₂濃度０．２％となる内添液を調製した。
【００３６】
＜内添剤調整例３＞
Ｎ−（２−アミノエチル）−３−アミノプロピルトリメトキシシラン（チッソ製サイラーエースＳ３２０）４．５ｇ（０．２ｍｏｌ）、２−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン（チッソ製サイラーエースＳ５３０）７．４ｇ（０．０３ｍｏｌ）、イソプロピルアルコール１３．５ｇ（０．２２５ｍｏｌ）、０．１Ｎ塩酸水溶液１３．５ｇ（０．７５ｍｏｌ）を１８時間室温で混合した。これを０．１Ｎ塩酸水溶液で希釈してＳｉＯ₂濃度１％となる内添液を調整した。
【００３７】
＜実施例１＞
ＮＢＫＰ（針葉樹漂白クラフトパルプ）／ＬＢＫＰ（広葉樹漂白クラフトパルプ）＝１／２の混合パルプを濾水度３７０ｃｓｆまで叩解したパルプを原料とし、上記内添剤調製例１により調製した内添剤を、ＳｉＯ₂換算重量／絶乾パルプ重量比が５％となるように添加し、５分間攪拌してシラン内添パルプを調製した。このパルプ材から湿式のパルプモールド成形法により重量１５ｇのパルプモールド容器を作成し、実施例１のシラン内添紙容器を得た。
【００３８】
＜実施例２＞
ＮＢＫＰ／ＬＢＫＰ＝１／２の混合パルプを濾水度３７０ｃｓｆまで叩解したパルプを原料とし、上記内添剤調製例１により調製した内添剤を、ＳｉＯ₂換算重量／絶乾パルプ重量比が１０％となるように添加し、５分間攪拌してシラン内添パルプを調製した。このパルプ材から湿式のパルプモールド成形法により重量１５ｇのパルプモールド容器を作成し、実施例２のシラン内添紙容器を得た。
【００３９】
＜実施例３＞
ＮＢＫＰ／ＬＢＫＰ＝１／２の混合パルプを濾水度３７０ｃｓｆまで叩解したパルプを原料とし、上記内添剤調製例２により調製した内添剤を、ＳｉＯ₂換算重量／絶乾パルプ重量比が１０％となるように添加し、５分間攪拌してシラン内添パルプを調製した。このパルプ材から湿式のパルプモールド成形法により重量１５ｇのパルプモールド容器を作成し、実施例３のシラン内添紙容器を得た。
【００４０】
＜従来例１＞
ＮＢＫＰ／ＬＢＫＰ＝１／２の混合パルプを濾水度３７０ｃｓｆまで叩解したパルプを原料とし、市販湿潤紙力増強剤（ポリアミドポリアミンエピクロルヒドリン；日本ＰＭＣ製ＷＳ５７０）、市販の撥水撥油剤（フッ素樹脂系；住友３Ｍ製スコッチバンＦＣ−８４５）、さらに市販のサイズ剤（アクリルケテンダイマー；日本ＰＭＣ製ＡＳ２６２）をそれぞれ固形分重量／絶乾パルプ重量比が１％、２％、２％となるように添加し、５分間攪拌して市販薬剤内添パルプを調製した。このパルプ材から湿式のパルプモールド成形法により重量１５ｇのパルプモールド容器を作成し、従来例２の市販薬剤内添紙容器を得た。
【００４１】
＜従来例２＞
ＮＢＫＰのパルプを濾水度３７０ｃｓｔまで叩解したパルプを原料とし、上記内添調整例３により調整した内添剤をＳｉＯ₂換算重量／絶乾パルプ重量比が１０％となるように添加し、５分間攪拌してシラン内添パルプを調整した。このパルプから湿式のパルプモールド成形法により重量１５ｇのパルプモールド容器を作成し、従来例２のシラン内添紙容器を得た。
【００４２】
＜試験例１＞
作成した紙容器は粉末状に粉砕して均一化し、蛍光Ｘ線でＳｉＯ₂濃度を測定し、内添剤の歩留まりを評価した。結果を図１に示す。図１より、本発明の紙容器の内添剤処方は、高濃度添加においても、歩留まりが極めて良好であることが分かる。
【００４３】
＜試験例２＞
作成した紙容器に対して、液体を充填する場合を想定し、８０℃熱水を紙容器に満たし、３０分経過後、熱水を捨てて、直ちに紙容器の座屈強度を測定した。座屈強度の測定は、万能試験機（エー・アンド・デイ製テンシロンＲＴＣ−１２５０）を用いて定速圧縮試験により、容器の座屈時の荷重を求めた。熱水充填前の乾燥状態での試験結果と合わせて、図２に示す。図２より、本発明のシラン内添紙容器は、１種の内添剤のみで、市販内添剤を組み合わせた従来例１よりも高い強度と耐水性を有していると言える。
【００４４】
＜試験例３＞
さらに作成した紙容器の底部の水平面を利用して、ＪＩＳＰ８１１７に従って透気度を、ＪＩＳＰ８１１９に従って平滑度を求めた。結果を図３，４に示す。図３，４から、本発明のシラン内添紙容器は、透気度、平滑度が上昇していることが分かる。
【００４５】
＜実施例４＞
実施例３で作成したシラン内添紙容器の内面に、モンモリロナイト、ポリビニルアルコールを重量比１／１で配合したコーティング剤を塗工し、１００℃のオーブンで乾燥させ、平均膜厚２５μｍの複合被膜を形成した。さらにイソシアネート樹脂からなるコーティング剤を塗工し、実施例４のシラン内添紙容器を得た。
【００４６】
＜実施例５＞
実施例３で作成したシラン内添紙容器の内面に、モノマーとしてヘキサメチルジシロキサンを用い、プラズマ重合により膜厚４００ｎｍの有機シリコーン系の薄膜を設け、実施例５のシラン内添紙容器を得た。
【００４７】
＜従来例３＞
従来例１で作成した市販薬剤内添紙容器の外面に、実施例４と同様のコーティングを行い、従来例３の紙容器を得た。
【００４８】
＜従来例４＞
従来例１で作成した市販薬剤内添紙容器の内面に、実施例５と同様の薄膜を設け、従来例４の紙容器を得た。
【００４９】
＜試験例４＞
作成した紙容器の底部の水平面を利用して、酸素透過度測定装置（モダンコントロール製ＯＸＴＲＡＮ１０／４０Ａ）を用いて、３０℃１００％ＲＨ雰囲気下での酸素透過度を、水蒸気透過度測定装置（モダンコントロール製ＰＥＲＭＡＴＲＡＮＷ６）を用いて、４０℃９０％ＲＨ雰囲気下での水蒸気透過度を測定した。
【００５０】
結果を表１に示す。表１から、本発明のシラン内添紙容器は、高いガスバリア性を有することが分かる。一方従来例の紙容器では、ピンホール等の欠陥によりガスバリア性が得られていない。
【００５１】
【表１】

【００５２】
以上本発明のシラン内添紙容器に関して具体的実施例を示したが、本発明は上記実施例および内添剤調製例に限定されるものではなく、また形態もパルプモールド容器に限らず、シラン内添パルプを用いて紙を抄造後、従来技術により容器成形した紙容器であっても構わない。また要求される特性によっては、全層にシラン化合物が内添されている必要はなく、例えば、多層抄きにより表層部分にのみシラン内添パルプを使用して、内添剤の使用量を削減することも可能である。
【００５３】
【発明の効果】
本発明のシラン内添紙容器は、天然素材を主原料とする紙容器であり、生分解性やリサイクル性を損なわず、またプラスチックとの複合化することなく、強度、耐水性、表面平滑性、ガスバリア性等の優れた特性を有し、液体容器、内容物保護のためガスバリア性を必要とする容器等、プラスチック容器代替への展開が可能である。また強度向上の効果があることから、目付重量減による材料削減の効果も期待できる。
また本発明に用いられるシラン化合物を主成分とする内添剤は、内添時のパルプスラリーのｐＨ調整を必要とせず、１液で様々な特性を付与でき、高歩留まりで高定着が可能なことから、従来の内添剤にない高い機能性付与が可能であり、薬剤ロスや排水処理の負荷も低減できる。
【図面の簡単な説明】
【図１】内添剤の歩留まりとＳｉＯ₂濃度を示すグラフ。
【図２】熱水処理前後での座屈時荷重変化を示すグラフ。
【図３】透気度を示すグラフ。
【図４】本実施例と従来例の平滑度を示すグラフ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper container excellent in strength, water resistance, surface smoothness, and gas barrier properties obtained by incorporating a silane compound uniformly into a pulp which is a natural material, and its shape is also free. It relates to a high-grade paper container.
[0002]
[Prior art]
Conventionally, plastic containers are widely used because they are excellent in water resistance and gas barrier properties and are easy to mold. However, elution of environmental hormones (endocrine disrupting substances) from some plastic containers has been reported, and the movement to switch to paper containers is increasing. Along with this, demands for high strength, water resistance, gas barrier properties, and the like are increasing for paper containers.
[0003]
Silane compounds typified by organosilanes have high heat resistance and water resistance strength, and are hydrolyzed with alkali, so that the strength, water resistance improvement, dimensional stability, Attempts have been made to treat silane compounds on paper or pulp mold containers for the purpose of improving friction resistance. Many of the methods are methods in which a plurality of types of organosilane compounds and hydrolysis catalysts are dissolved in an organic solvent and coated on paper or a pulp mold. Processing to a three-dimensional molded body is extremely inefficient. Moreover, since the segregation of the silane compound on the coating surface is large and the silane compound cannot be uniformly dispersed over the entire layer, the physical properties such as water resistance of the end face of the paper container are insufficient.
[0004]
Japanese Patent Application Laid-Open Nos. 10-212893 and 10-226890 propose a method of adding an organosilane compound into pulp slurry as an internal additive for papermaking. This method is merely an internal addition treatment in the pulp slurry, does not require a post-processing step, and the additive agent is uniformly distributed in the paper. However, like general internal additives for papermaking other than silanes, the fixing rate is only about 1% of the dry weight of the pulp (in terms of SiO ₂ weight), and there is a limit to improvement in strength and water resistance.
On the other hand, there is a concern that conventional general wet paper strength enhancers have a heavy burden on the environment, such as containing chlorine as a crosslinking reactive component or generating formaldehyde.
[0005]
Furthermore, the paper itself is a porous structure in which pulp fibers are gathered together, and has no gas barrier property. If the gas barrier property is necessary for protecting the contents of the container, it must be combined with plastic. It was.
[0006]
[Problems to be solved by the invention]
The present invention does not impair the biodegradability of cellulose and the recyclability of paper, and makes it possible to uniformly distribute silane compounds at a high concentration without adjusting the pH during internal addition or using a fixing agent, etc., for natural pulp. An object of the present invention is to provide a paper container made of a pulp material contained in the above, and having excellent strength, water resistance, surface smoothness, and gas barrier properties without being combined with plastic.
[0007]
[Means for Solving the Problems]
Invention of claim 1, a silane internally added paper container composed mainly of pulp material is a collection of plant fibers or plant fibers, the pulp material, the silane compound mainly internally added Pulp material prepared by adding an agent to the pulp slurry, and the silane compound is R ³ _n Si (OR ⁴ ) _m (OH) _4-mn (n = 0, 1, 2, 3) Or 0 ≦ n + m ≦ 4, m is an integer, R ³ is composed of one or more types of 1 to 10 carbon main chains and includes an epoxy group in its structure, R ² is a hydrocarbon having 1 to 3 carbon atoms) And at least one organosilane compound represented by: R ⁵ _n Si (OR ⁶ ) _m (OH) _4-mn (n = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is integer, R ⁵ consists of 1-10 carbon backbone, either carbon backbone or between terminal 1 Or having an amino group at both, R ⁶ comprises an organosilane compound represented by 1 to 3 carbon atoms in the hydrocarbon), wherein the silane compound is contained 2 to 20% in terms of SiO ₂ value on pulp dry weight a feature and be Resid run containing paper container to be.
[0008]
The invention according to claim 2 is characterized in that the fibers constituting the pulp are mainly composed of wood raw materials or natural materials such as bast fibers, seed hair fibers, leaf fibers, grass fibers and the like. Silane internal paper container.
[0009]
The invention according to claim 3 is the R ³ _n Si (OR ⁴ ) _m (OH) ₄ -mn (where n = 0, 1, 2, 3 or 0 ≦ n + m) according to claim 1. ≦ 4, m is an integer, R ³ is composed of one or more types of 1 to 10 carbon main chains and includes an epoxy group in its structure, R ² is a hydrocarbon having 1 to 3 carbon atoms) One or more compounds and R ⁵ _n Si (OR ⁶ ) _m (OH) _4-mn (n = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ⁵ is Mixture of organosilane compounds consisting of 1 to 10 carbon main chains and having an amino group at one or both of the carbon main chains or at the ends, and R ⁶ is a hydrocarbon having 1 to 3 carbon atoms) The silane-added paper container according to claim 1 or 2, wherein the molar ratio is 5/5 to 9.99 / 0.01.
[0010]
In the invention described in claim 4, the inner surface, the outer surface, or both surfaces of the silane-added paper container described in any one of claims 1 to 3 are coated with a mixed liquid composed of a water-soluble polymer and an inorganic layered mineral. This is a silane-containing paper container.
[0011]
The invention described in claim 5 is characterized in that a thin film by plasma polymerization is formed on the inner surface, outer surface, or both surfaces of the silane-added paper container described in any one of claims 1 to 4. It is an attached paper container.
[0012]
The invention according to claim 6 is such that the gas barrier property of the silane-added paper container according to any one of claims 1 to 5 is 10 cc / m ² / day in terms of m ² converted to m ² per day under 1 atm. Hereinafter, the silane-added paper container is characterized in that the water vapor permeability is 30 g / m ² / day or less.
[0013]
The invention according to claim 7 is a method for producing a silane-incorporated paper container mainly composed of plant fibers or pulp that is an aggregate of plant fibers, wherein the silane compound is treated with water under conditions of pH 7-14. A step of preparing an internal additive by mixing with a solvent, a step of preparing a pulp material by adding the internal additive to a pulp slurry, and a silane internal paper container by wet pulp molding from the pulp material Or forming the pulp material, and forming the silane-added paper into a silane-added paper container by a container molding technique, wherein the silane compound is R ³ _n Si (OR ⁴ ) _m (OH) _4-mn (n = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ³ is composed of one or more kinds of 1 to 10 carbon main chains) an epoxy group in its structure, R ² is from 1 to 3 carbon atoms And organosilane compound 1 or more represented by ^{_{^{_{hydrocarbon), R 5 n Si (OR}}}} 6) m (OH) 4-m-n ( one of n = 0,1,2,3, 0 ≦ n + m ≦ 4 , M is an integer, R ⁵ is composed of 1 to 10 carbon main chains, and has an amino group between one or both of the carbon main chains or at the ends, R ⁶ is a hydrocarbon having 1 to 3 carbon atoms) And a method for producing a silane-added paper container, comprising an organosilane compound represented by:
[0014]
The invention described in claim 8 is the R ³ _n Si (OR ⁴ ) _m (OH) ₄ -mn (where n = 0, 1, 2, 3 or 0 ≦ n + m). ≦ 4, m is an integer, R ³ is composed of one or more types of 1 to 10 carbon main chains and includes an epoxy group in its structure, R ² is a hydrocarbon having 1 to 3 carbon atoms) One or more compounds and R ⁵ _n Si (OR ⁶ ) _m (OH) _4-mn (n = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ⁵ is Mixture of organosilane compounds consisting of 1 to 10 carbon main chains and having an amino group at one or both of the carbon main chains or at the ends, and R ⁶ is a hydrocarbon having 1 to 3 carbon atoms) The method for producing a silane-added paper container according to claim 7, wherein the molar ratio is 5/5 to 9.99 / 0.01. .
[0015]
The invention according to claim 9 is an internal additive in which the SiO ₂ solid content concentration of the internal additive according to claim 8 is 0.01% or more and 5% or less, and the total solid content concentration including the resin component is 9. The method for producing a silane-added paper container according to claim 7, comprising a pulp material internally added with an internal additive of 2.5% to 40%. 9.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
A feature of the paper container of the present invention is that a silane compound can be added in a conventional papermaking slurry, a large amount of the silane compound can be retained in the paper, and the container has excellent strength, water resistance, and gas barrier properties.
[0019]
The material used as the raw material for the paper or pulp mold can be made by using the entanglement of the fiber, and can be anything as long as it can be made into a sheet or a molded body. It is desirable to use natural fiber. Currently, various natural products such as sugar cane and coffee are used as raw materials for paper, but these can also be used.
[0020]
Silane compounds that serve as raw materials for internal additives are abundant in types and are easily available industrially when organosilane is used. An internal additive liquid can be produced by proceeding hydrolysis and polymerization under basic conditions of pH 7 to 14, preferably 8 to 13. The pH adjustment is only necessary when preparing the internal additive, and it is not necessary to adjust the pH of the pulp slurry during the internal addition.
[0021]
In particular, it is desirable to use an amine-based organosilane in combination for effective fixing and function expression. At this time, the type of amine may be either primary amine or secondary amine. This organosilane is considered to function to promote the fixing of the internal additive to cellulose. It is presumed that the amine-based silane coupling agent plays both a catalytic action for hydrolyzing other organosilane compounds and a role as a trigger when fixing to pulp. In particular, since the catalytic effect as a basic catalyst is large, it is not necessary to add another catalyst.
[0022]
A silane coupling agent having an epoxy group in the structure is also effective in this method. In particular, those having a cyclohexyl epoxy group have a high combined effect, but the mechanism of action is not clear. An amine is an epoxy resinification catalyst, but it is unlikely that a cross-linked structure will occur in the present solvent or only under mixing conditions. When both are used together, it is thought that both silanol groups are becoming more complex, but it is presumed that the siloxane bond proceeds efficiently due to the steric hindrance of the epoxy group. .
[0023]
The amine-based organosilane is preferably in the range of 0.01 to 50 mol% (SiO ₂ equivalent value) of the silane coupling agent material constituting the internal additive, desirably 0.01 to 40 mol%. Within this range, improvement in water resistance, water repellency and surface smoothness can be expected. If the ratio of amine increases more than this, it becomes difficult to obtain water repellency. This is considered to be because the amino group which is a hydrophilic group is excessive in the internal additive. Incidentally, R ¹ according claims can not be sufficiently performed hydrolyzed but 11 or more. When R ² is 4 or more, the alcohol content of alkoxysilane cannot be removed.
[0024]
These internal additive materials are gently mixed at room temperature in an alcohol solvent such as isopropyl alcohol (IPA). The solvent at this time is for the purpose of homogenizing the components and is not limited to alcohol. Mixing for the preparation of the internal additive is extremely easy, with only gentle mixing at room temperature for about 1 hour to a maximum of about 20 hours. During this mixing, hydrolysis of the organosilane and proper complexation are promoted. In the hydrolysis of the organosilane compound, an acid or an alkali is added as a catalyst. However, in this formulation, it is not necessary to add an amine-based organosilane compound because it also serves as a catalyst. Therefore, the stability of the liquid is superior to the case where acid or alkali is added as a catalyst.
[0025]
Further, the SiO ₂ solid content concentration of the internal additive is light and the alcohol component is increased. Due to the large amount of the alcohol component, there is a disadvantage that handling during papermaking becomes inconvenient, and 0.01% or more is preferable. On the other hand, when the total solid content concentration increases to 10% or more, it gels and cannot be used. If it is 5% or more, it is inconvenient to handle even if it can be used. When the total solid content concentration including the resin content is 2.5% or less, the handling at the time of papermaking is similarly inconvenient. Furthermore, if the sizing degree of the paper is 20 seconds or less, the degree of water penetration increases and the paper container does not have sufficient water resistance.
[0026]
If the material has a relatively small organosilane substituent or an alkoxy group that is susceptible to hydrolysis, hydrolysis and conjugation proceed sufficiently by mixing for 1 to several hours.
[0027]
The internal additive after mixing and preparation is diluted as necessary in consideration of ease of addition to the pulp slurry and added to the pulp slurry. For the dilution, an alcohol / water mixture is optimal, and the type of alcohol is not limited. In order to limit alcohol mixing into white water as much as possible, the dilution rate can be reduced and the distribution of water can be increased.
[0028]
When a chemical is added to the pulp slurry according to this formulation, the fixing rate (yield) is 70 to 99%, and since it can be fixed at 20% or more in terms of SiO _{2 with} respect to the pulp dry weight, the required physical properties Depending on the condition, a predetermined concentration of drug is added. Since the yield is high, adjustment of the addition amount is easy, and the addition amount is adjusted according to the required paper properties.
It is not necessary to adjust the slurry pH for the addition regardless of the mixing ratio of the amine-based organosilane mixture.
[0029]
After adding the chemicals, papermaking or wet pulp molding is performed according to a normal process. With regard to the silane-added paper, the container is molded by a conventional container molding technique, and with respect to the pulp mold, the silane-added paper container having excellent strength, water resistance, surface smoothness, etc. according to the present invention is obtained only by the molding process. Can be obtained.
[0030]
Furthermore, since the silane-added paper container of the present invention has a smooth surface, high air permeability, and is dense, the container surface is coated with a mixed liquid composed of a water-soluble polymer and an inorganic layered mineral, or by plasma polymerization. When a thin film is formed, a barrier film free from defects such as pinholes is formed, and a paper container having excellent barrier properties is obtained without being combined with plastic.
[0031]
In this case, the water-soluble polymer is particularly preferably a polyvinyl alcohol-based resin, and the inorganic layered mineral is particularly preferably mormon-lilonite, and the thin film formed by plasma polymerization is particularly preferably an organic silica-based one. However, it is not limited to these. Moreover, when forming the coating film used as a barrier layer or a plasma polymerization thin film, a sealing layer or an overcoat layer may be provided.
[0032]
<Action>
The raw material of the internal additive is appropriately complexed through Si—O—Si bond during the stirring of the internal additive preparation, and a silica sol having both silanol and amino groups which are hydrophilic functional groups in the structure is formed. It is estimated that The interaction between the amino group in the sol and the carboxyl group in the pulp and the filter effect of the pulp are presumed to cause the sol to be entangled and fixed on the pulp. Furthermore, it is thought that the siloxane bond formation of unreacted silanol proceeds by heat drying at the time of paper making, and a three-dimensional crosslinked structure is formed in the paper to reinforce the bond between pulps. It is considered that hydrophilic amino groups are oriented inside the pulp, so that organic functional groups other than amino groups are oriented on the pulp surface, contributing to the improvement of characteristics such as water repellency and surface smoothness. It is expected that
[0033]
The silane-added paper container of the present invention obtained from this silane-added pulp material is particularly suitable for film formation on its surface because it has a smooth surface, high air permeability and is dense. It is easy to form a stable barrier film without defects such as. When a liquid mixture comprising a water-soluble polymer and an inorganic layered mineral is coated on the surface of the container, or a thin film is formed by plasma polymerization, the oxygen permeability in terms of m ² per day under 1 atm is 10 cc / m ² / day or less In addition, a high gas barrier property such as a water vapor permeability of 30 g / m ² / day or less can be obtained, and a gas barrier property sufficient for protecting contents can be obtained without being combined with plastic.
[0034]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
<Internal additive preparation example 1>
N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (Chizo Siler Ace S320) 4.5 g (0.02 mol), 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (Chiso Siler) Ace S530) 7.4 g (0.03 mol), isopropyl alcohol 13.5 g (0.225 mol), and water 13.5 g (0.75 mol) were mixed at room temperature for 18 hours. This was diluted with isopropyl alcohol to prepare an internal additive solution having a SiO ₂ concentration of 1%.
[0035]
<Internal additive preparation example 2>
1.1 g (0.005 mol) of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (Sisso Siler Ace S320), 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (Sisso Siler) Ace S530) 11.1 g (0.045 mol), isopropyl alcohol 13.5 g (0.225 mol), and water 13.5 g (0.75 mol) were mixed at room temperature for 18 hours. This was diluted with a water / isopropyl alcohol = 1/1 solution to a SiO ₂ concentration of 0.5%, and further diluted with water to prepare an internal additive solution having a SiO ₂ concentration of 0.2%.
[0036]
<Inner Additive Adjustment Example 3>
N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (Chizo Siler Ace S320) 4.5 g (0.2 mol), 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (Chisso Siler) Ace S530) 7.4 g (0.03 mol), isopropyl alcohol 13.5 g (0.225 mol) and 0.1N hydrochloric acid aqueous solution 13.5 g (0.75 mol) were mixed at room temperature for 18 hours. This was diluted with a 0.1N hydrochloric acid aqueous solution to prepare an internal additive solution having a SiO ₂ concentration of 1%.
[0037]
<Example 1>
NBKP (Conifer Bleached Kraft Pulp) / LBKP (Hardwood Bleached Kraft Pulp) = 1/2 mixed pulp beaten to a freeness of 370 csf, and the internal additive prepared in the above internal additive preparation example 1 was added to SiO ₂ in terms of weight / absolute dry pulp weight ratio of 5% was prepared 5 minutes stirring to silane in the added pulp. A pulp mold container having a weight of 15 g was prepared from this pulp material by a wet pulp mold forming method, and the silane-added paper container of Example 1 was obtained.
[0038]
<Example 2>
Using the pulp obtained by beating NBKP / LBKP = 1/2 mixed pulp to a freeness of 370 csf as a raw material, the internal additive prepared in the above-mentioned internal additive preparation example 1 has an SiO ₂ equivalent weight / absolute dry pulp weight ratio of 10 % And stirred for 5 minutes to prepare a silane-added pulp. A pulp mold container having a weight of 15 g was prepared from this pulp material by a wet pulp molding method, and a silane-added paper container of Example 2 was obtained.
[0039]
<Example 3>
Using the pulp obtained by beating NBKP / LBKP = 1/2 mixed pulp to a freeness of 370 csf as a raw material, the internal additive prepared by the above internal additive preparation example 2 has a weight ratio of SiO ₂ equivalent weight / absolute dry pulp of 10 % And stirred for 5 minutes to prepare a silane-added pulp. A pulp mold container having a weight of 15 g was prepared from this pulp material by a wet pulp molding method, and a silane-added paper container of Example 3 was obtained.
[0040]
<Conventional example 1>
A pulp obtained by beating NBKP / LBKP = 1/2 pulp to a freeness of 370 csf as a raw material, a commercially available wet paper strength enhancer (polyamide polyamine epichlorohydrin; WS570 manufactured by Japan PMC), a commercially available water and oil repellent (fluorine resin type) Scotch Van FC-845 manufactured by Sumitomo 3M) and a commercially available sizing agent (acrylic ketene dimer; AS262 manufactured by Nippon PMC) so that the solid weight / absolute pulp weight ratio is 1%, 2% and 2%, respectively. The mixture was added and stirred for 5 minutes to prepare a commercially available drug-added pulp. A pulp mold container having a weight of 15 g was prepared from this pulp material by a wet pulp molding method, and a commercially available drug-added paper container of Conventional Example 2 was obtained.
[0041]
<Conventional example 2>
Using pulp obtained by beating NBKP pulp to a freeness of 370 cst as a raw material, the internal additive prepared according to the internal addition adjustment example 3 is added so that the SiO ₂ equivalent weight / absolute dry pulp weight ratio is 10%. The silane-containing pulp was prepared by stirring for a minute. A pulp mold container having a weight of 15 g was prepared from this pulp by a wet pulp mold forming method, and a silane-added paper container of Conventional Example 2 was obtained.
[0042]
<Test Example 1>
The produced paper container was pulverized and homogenized into a powder, and the SiO ₂ concentration was measured by fluorescent X-rays to evaluate the yield of the internal additive. The results are shown in FIG. From FIG. 1, it can be seen that the internal additive formulation of the paper container of the present invention has a very good yield even at high concentration.
[0043]
<Test Example 2>
Assuming that the prepared paper container is filled with liquid, the paper container was filled with 80 ° C. hot water, and after 30 minutes, the hot water was discarded and the buckling strength of the paper container was measured immediately. For the buckling strength measurement, the load at the time of buckling of the container was determined by a constant speed compression test using a universal testing machine (Tensilon RTC-1250 manufactured by A & D). Together with the test results in the dry state before filling with hot water, it is shown in FIG. From FIG. 2, it can be said that the silane internal paper container of the present invention has only one kind of internal additive and has higher strength and water resistance than Conventional Example 1 in which a commercially available internal additive is combined.
[0044]
<Test Example 3>
Furthermore, using the horizontal surface of the bottom of the paper container thus prepared, the air permeability was determined according to JIS P8117, and the smoothness was determined according to JIS P8119. The results are shown in FIGS. 3 and 4, it can be seen that the air permeability and smoothness are increased in the silane-added paper container of the present invention.
[0045]
<Example 4>
A coating agent in which montmorillonite and polyvinyl alcohol were blended at a weight ratio of 1/1 was applied to the inner surface of the silane-added paper container prepared in Example 3, and dried in an oven at 100 ° C., and a composite film having an average film thickness of 25 μm Formed. Furthermore, the coating agent which consists of isocyanate resins was applied, and the silane internal paper container of Example 4 was obtained.
[0046]
<Example 5>
An organosilicone thin film having a film thickness of 400 nm is provided by plasma polymerization on the inner surface of the silane-added paper container prepared in Example 3 to obtain a silane-added paper container of Example 5. It was.
[0047]
<Conventional example 3>
The same coating as in Example 4 was applied to the outer surface of the commercially available drug-added paper container prepared in Conventional Example 1 to obtain a paper container of Conventional Example 3.
[0048]
<Conventional Example 4>
A thin film similar to Example 5 was provided on the inner surface of the commercially available drug-added paper container prepared in Conventional Example 1 to obtain a paper container of Conventional Example 4.
[0049]
<Test Example 4>
Using the horizontal plane at the bottom of the created paper container, the oxygen permeability in a 100% RH atmosphere at 30 ° C. was measured using the oxygen permeability measurement device (OXTRAN 10 / 40A manufactured by Modern Control). The water vapor permeability was measured at 40 ° C. and 90% RH using (Modern Control PERMATRAN W6).
[0050]
The results are shown in Table 1. From Table 1, it can be seen that the silane-containing paper container of the present invention has a high gas barrier property. On the other hand, in the conventional paper container, gas barrier properties are not obtained due to defects such as pinholes.
[0051]
[Table 1]

[0052]
Specific examples of the silane-containing paper container of the present invention have been described above. However, the present invention is not limited to the above examples and preparation examples of internal additives, and the form is not limited to the pulp mold container. It may be a paper container which is made from paper using an internally added pulp and then molded into a container by a conventional technique. Depending on the required properties, the silane compound does not need to be internally added to all layers. For example, by using multi-layered paper, silane-added pulp is used only on the surface layer to reduce the amount of internal additive used. It is also possible to do.
[0053]
【The invention's effect】
The silane-added paper container of the present invention is a paper container made of natural materials as its main raw material, and does not impair biodegradability and recyclability, and without being combined with plastic, strength, water resistance, surface smoothness It has excellent properties such as gas barrier properties, and can be used as an alternative to plastic containers such as liquid containers and containers that require gas barrier properties to protect the contents. Moreover, since there is an effect of improving the strength, an effect of material reduction by reducing the weight per unit area can be expected.
Further, the internal additive mainly composed of the silane compound used in the present invention does not require pH adjustment of the pulp slurry at the time of internal addition, and can impart various characteristics with one liquid, and can achieve high fixing with high yield. Therefore, it is possible to impart high functionality not found in conventional internal additives, and it is possible to reduce chemical loss and wastewater treatment load.
[Brief description of the drawings]
FIG. 1 is a graph showing the yield of an internal additive and the SiO ₂ concentration.
FIG. 2 is a graph showing changes in buckling load before and after hot water treatment.
FIG. 3 is a graph showing air permeability.
FIG. 4 is a graph showing the smoothness of the present example and the conventional example.

Claims

A silane internally added paper container composed mainly of pulp material is a collection of plant fibers or plant fibers,
The pulp material is a pulp material prepared by adding an internal additive mainly composed of a silane compound to a pulp slurry,
The silane compound is R ³ _n Si (OR ⁴ ) _m (OH) _4-mn (n = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ³ is 1 One or more organosilane compounds represented by R ² is a hydrocarbon having 1 to 3 carbon atoms , which is composed of one or more types of 10 to 10 carbon main chains and includes an epoxy group in its structure, and R ⁵ _n Si ( OR ⁶ ) _m (OH) _4-mn (n = 0, 1, 2, 3, 0 ≦ n + m ≦ 4, m is an integer, R ⁵ is composed of 1 to 10 carbon main chains, An organosilane compound having an amino group between one or both of the carbon main chains or at the ends, and R ⁶ is a hydrocarbon having 1 to 3 carbon atoms),
The silane compound, wherein the to Resid run containing paper container that contains 2 to 20% in terms of SiO ₂ values for the pulp dry weight.

The silane-added paper container according to claim 1, wherein the fibers constituting the pulp are mainly made of wood raw materials or natural materials such as bast fibers, seed hair fibers, leaf fibers and grass fibers.

R according to claim 1 ^３3 _ｎn Si (OR ^４4 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^３3 Is composed of 1 to 10 carbon main chains and contains an epoxy group in its structure, R ^２2 Is one or more organosilane compounds represented by C 1-3 hydrocarbons, and R ^５5 _ｎn Si (OR ^６6 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^５5 Is composed of 1 to 10 carbon main chains, and has an amino group between one or both of the carbon main chains or at the ends, R ^６6 3. The silane-containing paper container according to claim 1, wherein a mixing molar ratio of the organosilane compound represented by (C 1 -C 3 hydrocarbon) is 5/5 to 9.99 / 0.01.

A silane-added paper container characterized in that a mixed liquid comprising a water-soluble polymer and an inorganic layered mineral is coated on the inner surface, outer surface, or both surfaces of the silane-added paper container according to any one of claims 1 to 3. .

A silane-containing paper container, wherein a thin film by plasma polymerization is formed on an inner surface, an outer surface, or both surfaces of the silane-containing paper container according to any one of claims 1 to 4.

The gas barrier property of the silane-added paper container according to any one of claims 1 to 5 is 10 cc / m in oxygen permeability in terms of m2 per day at 1 atm. ^２2 / Day or less, water vapor permeability is 30 g / m ^２2 / Day or less, a silane-containing paper container.

A method for producing a silane-added paper container mainly composed of plant fiber or pulp that is an aggregate of plant fibers,
Mixing the silane compound with a solvent containing water under conditions of pH 7 to 14 to prepare an internal additive;
Adding the internal additive to the pulp slurry to prepare a pulp material;
A step of forming a silane-incorporated paper container from the pulp material by a wet pulp molding method or a step of paper-making the pulp material, and forming the resulting silane-incorporated paper into a silane-added paper container by a container molding method; With
The silane compound is R ^３3 _ｎn Si (OR ^４4 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^３3 Is composed of 1 to 10 carbon main chains and contains an epoxy group in its structure, R ^２2 Is one or more organosilane compounds represented by C 1-3 hydrocarbons, and R ^５5 _ｎn Si (OR ^６6 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^５5 Is composed of 1 to 10 carbon main chains, and has an amino group between one or both of the carbon main chains or at the ends, R ^６6 Includes an organosilane compound represented by a hydrocarbon having 1 to 3 carbon atoms)
A method for producing a silane-containing paper container.

R according to claim 7 ^３3 _ｎn Si (OR ^４4 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^３3 Is composed of 1 to 10 carbon main chains and contains an epoxy group in its structure, R ^２2 Is one or more organosilane compounds represented by C 1-3 hydrocarbons, and R ^５5 _ｎn Si (OR ^６6 ) _ｍm (OH) _{４−ｍ−ｎ4-mn} (N = 0, 1, 2, 3 or 0 ≦ n + m ≦ 4, m is an integer, R ^５5 Is composed of 1 to 10 carbon main chains, and has an amino group between one or both of the carbon main chains or at the ends, R ^６6 The method for producing a silane-added paper container according to claim 7, wherein the mixing molar ratio of the organosilane compound represented by (C1-3 hydrocarbon) is 5/5 to 9.99 / 0.01.

SiO of the internal additive according to claim 8 _２2 It is an internal additive having a solid content of 0.01% or more and 5% or less, and is made of a pulp material internally added with an internal additive having a total solid content concentration of 2.5% or more and 40% or less including the resin content. The method for producing a silane-incorporated paper container according to claim 7 or 8.