JP3942883B2 - Biodegradable release sheet and label product using the same - Google Patents

Description

〔式（１）において、Ｘは炭素数２０以下のアルキル基、シクロアルキル基、アリール基、アリールアルキル基または、水素、水酸基、ニトロ基、アミノ基、アシル基、スルホン酸基、アルコキシル基およびハロゲンを示し、Ｍはリチウム、ナトリウム、カリウムまたは下記式（３）で表されるアミンを示す。また、ｍ１は０〜３の整数であり、ｍ２は１〜４の整数であって、ｍ１＋ｍ２は、１≦ｍ１＋ｍ２≦４の関係を満たす。また、ｎ１は１以上の整数を示す。〕
【化８】

〔式（２）において、Ｒ¹ は炭素数２０以下のアルキリデン基を示し、Ｍはリチウム、ナトリウム、カリウムまたは下記式（３）で表されるアミンを示す。〕
【化９】

〔式（３）において、Ｒ² 、Ｒ³ 、Ｒ⁴ およびＲ⁵ はそれぞれ独立に水素、アルキル基、フェニル基またはベンジル基を示す。〕
【００１１】
上記請求項２の発明によれば、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物でなる生分解性を有する印刷層を被覆している生分解性を有する離型剤層として、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物を使用しているため、易剥離性と耐熱性を有しているので印刷層によるブロッキングと印刷層の転移を防止し、かつ使用後の廃棄に際し、この離型剤層を有するフィルムや紙等が、離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。また、離型剤層に皮膜形成が容易な上記スルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステル樹脂を使用しているため、基材に上質紙等通常紙を用いた場合でも目止め層としてのポリエチレン層が不必要となり、よって工程の簡略化とともに廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００１３】
上記請求項１の発明によれば、基材の片面に生分解性離型剤層で被覆されるポリ乳酸セグメントとポリグリセリンセグメントとから成る、ポリ乳酸セグメント中に乳酸残基を８０モル％以上含む脂肪族ポリエステルを主たるバインダーとする印刷インキで形成される生分解性を有する印刷層を施したものとすることによって、生分解性離型シートに絵柄（例えばシールを剥がすと動物の絵がでてくる幼児用シールなど）や各種情報（例えば「これは、土中で分解する環境にやさしい生分解性離型シートです」など）等によるデザイン性を付与し、再利用も可能な生分解性離型シートとし、かつこれら生分解性離型シートの使用後の廃棄に際し、この印刷層を有するフィルムや紙等が、印刷層と離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００１７】
上記請求項２の発明によれば、生分解性を有するフィルムあるいは紙の片面に設ける印刷インキ層の主たるバインダーとして、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物を使用しているため、使用後の廃棄に際し、これら印刷層を有するフィルムや紙等がこの印刷層と離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００１８】
上記請求項２に係わる発明のスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステル樹脂と、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物をを主たるバインダーとする印刷インキは、一般に、インキ適性（印刷適性）を確保するため種々の補助成分を含有している。そしてこの補助成分のため、印刷後の生分解性離型シートを多数枚重ねて保管する場合に、これら印刷層が隣接する生分解性離型シートに接着するブロッキングを生じ易い。また、例えばシールの粘着剤に仮粘着させた際に、上記印刷層が粘着剤に転移して粘着剤を汚染することもある。
【００１９】
従って、上記請求項１または２に係る発明においては、上記請求項１または２に係わる発明の印刷層を被覆して、ポリ乳酸セグメントとポリグリセリンセグメントとを有するポリ乳酸系樹脂と、有機溶剤可溶性多糖類もしくは多官能イソシアネートの混合物から成る、または上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物から成る易剥離性と耐熱性のある離型剤層としているため、これら印刷層による隣接する生分解性離型シートやシールラベル等の粘着剤へのブロッキングや転移を防止して、長期の保管と移送とを容易にして、品質に対する信頼性の向上を図ることも兼ねているものである。
さらにまた、請求項３の発明では、上記請求項１または２のいずれかに記載の生分解性離型シートを用いたラベル製品であって、前記生分解性離型シートの離型剤層面がラベル基材に施されている粘着剤層面に仮粘着されていることを特徴とするラベル製品としたものである。
【００２０】
【発明の実施の形態】
以下本発明の実施の形態を説明する。
本発明は、例えば図１の積層側断面図に示すように、生分解性を有するフィルムを基材（１０）とし、この基材（１０）の片面に、生分解性を有する離型剤層（１４）が施され、この基材（１０）と離型剤層（１４）との間に生分解性を有する印刷層（１６）が施されている生分解性離型シート（４）としたもので、この生分解性離型シート（４）は、例えば図２の積層側断面図に示すように、ラベル用紙（２）に粘着剤層（３）が施されたシールラベル（１）の粘着剤層（３）面に生分解性離型シート（４）の離型剤層（１４）面が仮粘着されて使用されるものである。さらに図３の積層側断面図に示すように、この生分解性離型シート（４）の離型剤層（１４）面からシールラベル（１）を剥離し、残った生分解性離型シート（４）は廃棄されるものである。但し上記のように印刷層（１６）が施されているものは、再利用をも可能にする生分解性離型シート（４）とすることもできる。
【００２１】
上記本発明に係る基材（１０）である生分解性を有するフィルムとしては任意のものが使用できるが、その製膜加工性、透明性、生分解性能などの理由から、ポリ乳酸系フィルムが好適に利用できる。なお、ポリ乳酸系フィルムは温度と湿度の双方が一定の条件以上で整った場合に加水分解を始める。さらに加水分解によって小さくなった分子を微生物が摂取することで分解が促進されるものである。
【００２２】
従って、ポリ乳酸フィルムは、通常の離型シートの保管条件では加水分解が開始されず、従って、この点からも製品工場に対して、安定した品質の生分解性離型シートを供給することができる。また、シールラベルの如き製品とした後も加水分解が開始されないため、店舗における製品販売の際にも品質の劣化がない。このため、長期間の流通過程に乗せられる製品の離型シートに適している。このポリ乳酸フィルムは、コンポスト内に放置した場合に速やかに分解される。
【００２３】
このポリ乳酸フィルムとしては、例えば、ユニチカ（株）製テラマック、三菱樹脂（株）製エコロージュ、東セロ（株）製パルグリーンＬＣなどが挙げられる。これら市販のポリ乳酸フィルムは、例えば図２に示すシールラベル用等の生分解性離型シートとして好適なフィルムである。
【００２４】
上記ポリ乳酸フィルムの厚みとしては、５〜１００μｍが好適である。好ましくは１０〜４０μｍで、特にシールラベル用等では比較的厚めのものが使用され、また宅配便等の伝票や両面粘着テープ用等には比較的薄めのものが好適であるように用途によって選定することができる。
【００２５】
また、上記基材（１０）として、生分解性のある紙とすることもできる。この紙としては、坪量５０〜２００ｇ／ｍ² の範囲のグラシン紙、クラフト（晒、半晒、未晒等）紙、あるいは上質紙、コート紙等が好適に用いられ、プラスチックフィルムの場合と同様にシールラベル用等では比較的厚めのものが使用され、また宅配便等の伝票や両面粘着テープ用等には比較的薄めのものが好適であるように紙の種類とともに用途によって選定することができる。
る。
【００２６】
次に、上記離型剤層（１４）に使用されるポリ乳酸系樹脂としては、ポリ乳酸セグメント中に乳酸残基を８０モル％以上含んでいるものが望ましく、また、Ｌ−乳酸残基とＤ−乳酸残基とをＬ／Ｄモル比が１〜９の範囲となるように含んでいることが望ましい。また、還元粘度が０．３〜１．０ｄｌ／ｇ、ガラス転移点が４０〜６０℃の範囲にあることが望ましい。
【００２７】
このようなポリ乳酸系樹脂は、乳酸の二量体であるラクチド及びポリグリセリン等の添加物を溶融混合し、加熱開環触媒の存在下で加熱開環重合させたり、加熱と減圧により直接脱水重合させる方法などで得ることができる。
【００２８】
また、離型剤層（１４）に使用される上記有機溶剤可溶性多糖類としては、ニトロセルロース、酢酸セルロース、エステル化デンプンなどが例示できる。
これらの混合比としては、ポリ乳酸系樹脂１００重量部に対し有機溶剤可溶性多糖類５〜４０重量部が好ましい。
【００２９】
また、離型剤層（１４）に使用される上記多官能イソシアネートとしては、ヘキサメチレンジイソシアネート、トリレンジイソシアネート（ＴＤＩ）、ジフェニルメタンジイソシアネート（ＭＤＩ）、水添ＴＤＩ、水添ＭＤＩ、などの２官能イソシアネートや、ヘキサメチレンジイソシアネート３量体などの３官能イソシアネート、などが挙げられる。
これらの混合比としては、ポリ乳酸系樹脂１００重量部に対し多官能イソシアネート０．５〜２０重量部が好ましい。
【００３０】
さらにまた、離型剤層（１４）に使用される上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルとしては、例えば上記式（１）で表されるスルホン酸含有化合物とヒドロオキシ酸との共重合で得られ、例えば、乳酸の二量体であるラクチドと、上記スルホン酸含有化合物とを溶融混合し、公知の開環重合触媒、例えば、オクチル酸、アルミニウムアセチルアセトナート等を使用して加熱開環重合させる方法や加熱および減圧による直接脱水重縮合を行う方法等が挙げられる。
【００３１】
上記のようにして得られるポリヒドロキシ酸系ポリエステルとしては、ポリエステル中のスルホン酸塩の濃度が５〜１００当量／１０⁶ ｇであることが望ましく、またポリヒドロキシ酸系ポリエステルが乳酸系ポリエステルである場合には、乳酸系ポリエステル中に乳酸残基が８０モル％以上含まれていることが望ましい。
また、上記乳酸系ポリエステルがＬ−乳酸残基とＤ−乳酸残基とを含んでいる場合には、Ｌ−乳酸残基のモル数（Ｌ）とＤ−乳酸残基モル数（Ｄ）のモル比（Ｌ／Ｄ）が１〜９の範囲であることが望ましい。なお乳酸としては、Ｌ−乳酸、Ｄ−乳酸、ＤＬ−乳酸のいずれも用いることができる。
【００３２】
また、上記のようにして得られたポリヒドロキシ酸系ポリエステルの還元粘度は、０．３〜１．５ｄｌ／ｇの範囲であることが好ましく、またガラス転移点が３５〜６０℃の範囲であることが好ましい。
【００３３】
なお、上記離型剤層（１４）は、適切な有機溶剤に溶解または分散させて印刷または塗布で得ることができる。その有機溶剤としては、例えば、トルエン、メチルエチルケトン、酢酸エチル等が使用できる。
【００３４】
また本発明では、例えば図１に示すように、生分解性を有する基材（１０）と生分解性を有する離型剤層（１４）との間に生分解性を有する印刷層（１６）が施されている生分解性離型シート（４）とするものである。
【００３５】
この印刷層（１６）としては、着色剤と、この着色剤を生分解性フィルム上に固定するバインダーとを主成分とし、これにインキ適性（印刷適性）を向上させる各種補助成分を添加した印刷インキから構成することができる。
上記着色剤としては、着色顔料または染料が利用できるが、その耐光性などの点から顔料が好適である。
【００３６】
上記印刷インキを構成するバインダーとして使用するポリ乳酸セグメントとポリグリセリンセグメントとから成る脂肪族ポリエステルとしては、ポリ乳酸セグメント中に乳酸残基を８０モル％以上含んでいるものが望ましく、また、Ｌ−乳酸残基とＤ−乳酸残基とをＬ／Ｄモル比が１〜９の範囲となるように含んでいることが望ましい。また、ポリグリセリンセグメントの重合度は３〜２０の範囲にあることが望ましい。また、上記脂肪族ポリエステルとしては、還元粘度が０．３〜１．０ｄｌ／ｇ、ガラス転移点が４０〜６０℃の範囲にあることが望ましい。
【００３７】
このような脂肪族ポリエステルは、乳酸の二量体であるラクチドに乳酸とポリグリセリンとを溶融混合し、公知の開環重合触媒を使用して加熱開環重合させたり、加熱と減圧により直接脱水重合させる方法などで得ることができる。また、高分子量ポリ乳酸や乳酸セグメントを製造した後、ウレタン基やエポキシ基などを利用して、ポリグリセリンセグメントを反応させて得ることもできる。乳酸としては、Ｌ―乳酸、Ｄ−乳酸、ＤＬ−乳酸などが使用できる。
【００３８】
さらにまた、バインダーとして使用する上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルとしては、上記離型剤層（１４）の項で述べたものと同様なので省略する。
【００３９】
次に、印刷インキ中の上記各種補助成分としては、印刷層（１６）に耐摩擦性や滑り性を与えるワックス、印刷層（１６）に柔軟性を与え、また、インキの生分解性フィルム上への転移性を向上させる可塑剤や消泡剤、あるいは、顔料分散剤、粘度調整剤、皮膜調整剤、乾燥調整剤などがある。これら補助成分は印刷方式や条件に応じて、適切なものを適量添加すれば良い。
これら印刷インキは、例えば、グラビア印刷で印刷することができる。多色の印刷インキを重ね刷りすることによりカラーの印刷層（１６）を構成することも可能である。
【００４０】
以上のように、上記印刷層（１６）を被覆して設けられている本発明に係る離型剤層（１４）は、易剥離性とともに比較的耐熱性があるので、印刷層（１６）によるブロッキングや転移を防止する役目をもしているものである。
【００４１】
本発明に係わる生分解性離型シート（４）は、例えば図２に示すように、シールラベル（１）用として用いられる他、宅配便等の粘着型伝票用、両面粘着テープ用あるいは封筒等の封緘口に設ける粘着剤のカバー用などとして好適に利用することができる。
【００４２】
次に、一事例により、本発明をさらに具体的に説明する。
図１に示すように、基材（１０）としての生分解性フィルムとして、ユニチカ（株）製ポリ乳酸フィルムを利用した。このポリ乳酸フィルムの融点は１７０℃であり、二軸延伸して厚みは２５μｍのフィルムとした。
【００４３】
次に、グラビア印刷を利用して、基材（１０）の裏面側（図面では上面）に、印刷層（１６）を形成した。この印刷層（１６）に適用したインキは、ポリ乳酸セグメントとポリグリセリンセグメントとから成る脂肪族ポリエステルから成るバインダー１００重量部に着色顔料１０重量部と有機溶剤として酢酸プロピル２００重量部を混合し、各種補助成分を添加してその印刷適性を調整したものである。
【００４４】
上記バインダーは、次の方法で合成したものである。すなわち、ＤＬラクチド１０００部、重合度が１０であるポリグリセリン１０部、開環重合触媒としてアルミニウムアセチルアセテート１重量部をフラスコに仕込み、窒素雰囲気中で１８０℃、３時間の条件で加熱溶融させることにより開環重合させ、残留ラクチドを減圧下留去させることにより、上記バインダーを製造した。
このバインダー中の乳酸残基は９９モル％、Ｌ−乳酸残基とＤ−乳酸残基とのＬ／Ｄモル比は１、還元粘度は０．４９ｄｌ／ｇ、ガラス転移点が４９℃であった。
【００４５】
次に、この印刷層（１６）を被覆して離型剤層（１４）を塗布して得た。この離型剤層（１４）はポリ乳酸セグメントと、ポリグリセリンセグメントとを有するポリ乳酸系樹脂１００重量部に対し、有機溶剤可溶性のニトロセルロース２０重量部を混合したもので、有機溶剤に溶解させ、グラビア印刷法により塗布した。
このポリ乳酸系樹脂は、次の方法で合成したものである。すなわち、ＤＬラクチド１０００重量部、重合度が１０であるポリグリセリン１０重量部、開環重合触媒としてアルミニウムアセチルアセテート１重量部をフラスコに仕込み、窒素雰囲気中で１８０℃、３時間の条件で加熱溶融させることにより開環重合させ、残留ラクチドを減圧下留去させることにより、上記バインダーを製造した。
このポリ乳酸系樹脂中の乳酸残基は９９モル％、Ｌ−乳酸残基とＤ−乳酸残基とをＬ／Ｄモル比は１、還元粘度は０．４９ｄｌ／ｇ、ガラス転移点は４９℃であった。
【００４６】
こうして得られた生分解性離型シート（４）を使用して、図２に示すように、ラベル用紙（２）の裏面に粘着剤層（３）が施されているシールラベル（１）に仮粘着された製品とした。
【００４７】
上記で得られたラベル製品の使用時に、生分解性離型シート（４）からシールラベル（１）を剥離し、残った生分解性離型シート（４）の生分解性能を確認したところ、基材（１０）フィルム、印刷層（１６）、離型剤層（１４）のいずれも良好な生分解性能を示し、短期間のうちに分解するものであった。
【００４８】
【発明の効果】
本発明は以上の構成であるから、下記に示す如き効果がある。
即ち、上記請求項１の発明においては、紙を除き、従来のポリエステル、ポリエチレン、ポリプロピレン等プラスチックフィルムに代え、生分解性を有するフィルムを基材とし、かつ従来のシリコーン樹脂に代え、生分解性を有する離型剤層としたので、使用後の廃棄に当たって、これら基材や離型剤層が雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を軽減し、環境汚染を防止する生分解性離型シートとすることができる。また、基材が紙の場合も、生分解性を有する離型剤層としたので、紙の生分解性を阻害されることなく、離型剤層とともに分解されるので、環境に係わる同様の効果を発揮するものである。
【００４９】
また、上記請求項１の発明においては、ポリ乳酸セグメントとポリグリセリンセグメントとから成る、ポリ乳酸セグメント中に乳酸残基を８０モル％以上含む脂肪族ポリエステルを主たるバインダーとする印刷インキで形成される生分解性を有する印刷層を被覆している生分解性を有する離型剤層に、ポリ乳酸セグメントとポリグリセリンセグメントとを有するポリ乳酸系樹脂と、ポリ乳酸系樹脂１００重量部に対し有機溶剤可溶性多糖類５〜４０重量部を混合比とする有機溶剤可溶性多糖類もしくはポリ乳酸系樹脂１００重量部に対し多官能イソシアネート０．５〜２０重量部を混合比とする多官能イソシアネートとの混合物を使用しているため、易剥離性と耐熱性を有しているので、印刷層によるブロッキングや印刷層の転移を防止し、かつ使用後の廃棄に際し、この離型剤層を有するフィルムや紙等が、離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。また、離型剤層に皮膜形成が容易な上記ポリ乳酸系樹脂を使用しているため、基材に上質紙等通常紙を用いた場合でも目止め層としてのポリエチレン層が不必要となり、よって工程の簡略化とともに廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００５０】
また、上記請求項２の発明においては、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物でなる生分解性を有する印刷層を被覆する生分解性を有する離型剤層に、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物を使用しているため、易剥離性と耐熱性を有しているので印刷層によるブロッキングと印刷層の転移を防止し、かつ使用後の廃棄に際し、この離型剤層を有するフィルムや紙等が、離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
また、離型剤層に皮膜形成が容易な上記スルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステル樹脂を使用しているため、基材に上質紙等通常紙を用いた場合でも目止め層としてのポリエチレン層が不必要となり、よって工程の簡略化とともに廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００５１】
また、上記請求項１または２の発明においては、基材の片面に生分解性離型剤層で被覆される生分解性を有する印刷層を施したものとすることによって、生分解性離型シートに絵柄や各種情報などによるデザイン性を付与し、再利用も可能にした生分解性離型シートとし、かつ使用後の廃棄に際し、この印刷層を有するフィルムや紙等が、印刷層と離型剤層とともに雑菌（分解性雑菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００５２】
さらに、上記請求項１の発明においては、生分解性を有するフィルムあるいは紙の片面に設ける印刷インキ層の主たるバインダーとしてポリ乳酸セグメントとポリグリセリンセグメントとから成る、ポリ乳酸セグメント中に乳酸残基を８０％以上含む脂肪族ポリエステルを使用しているため、使用後の廃棄に際し、これら印刷層を有するフィルムや紙等がこの印刷層と離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００５３】
さらにまた、上記請求項２の発明においては、生分解性を有するフィルムあるいは紙の片面に設ける印刷インキ層の主たるバインダーとして、上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物を使用しているため、使用後の廃棄に際し、これら印刷層を有するフィルムや紙等がこの印刷層と離型剤層とともに雑菌（分解性細菌）に曝されて分解され、廃棄物に係わる環境の負荷を低減し、より一層の環境汚染を防止する生分解性離型シートとすることができる。
【００５４】
なお、上記請求項１または２に係る発明においては、上記請求項１または２に係わる発明の印刷層を被覆して、ポリ乳酸セグメントとポリグリセリンセグメントとを有するポリ乳酸系樹脂と、有機溶剤可溶性多糖類もしくは多官能イソシアネートの混合物から成る、または上記式（１）および／または（２）で表されるスルホン酸塩含有構造を分子鎖に含むポリヒドロキシ酸系ポリエステルと、有機溶剤可溶性多糖類もしくは多官能イソシアネートとの混合物から成る易剥離性と耐熱性のある離型剤層としているため、これら印刷層による隣接する生分解性離型シートやラベル製品の粘着剤へのブロッキングや転移を防止して、長期の保管と移送とを容易にして、品質に対する信頼性の向上を図ることも兼ねているものである。
【００５５】
従って本発明は、シールラベルや宅配便の伝票、両面粘着テープ等ラベル製品に用いられる離型シートで、特に、印刷層によるブロッキングや印刷層の他のものへの転移を防止し、使用後の廃棄に際し、環境に係わる負荷を軽減し、環境汚染を防止する生分解性離型シートとして、優れた実用上の効果を発揮する。
【図面の簡単な説明】
【図１】本発明の生分解性離型シートの一事例を側断面で表した説明図である。
【図２】本発明の生分解性離型シートを用いた製品の一事例を側断面で表した説明図である。
【図３】本発明の生分解性離型シートを用いた製品の使用時の一事例を側断面で表した説明図である。
【符号の説明】
１‥‥シールラベル
２‥‥ラベル用紙
３‥‥粘着剤層
４‥‥生分解性離型シート
１０‥‥基材
１４‥‥離型剤層
１６‥‥印刷層[0001]
BACKGROUND OF THE INVENTION
The present invention includes seal labels, courier slips, double-sided adhesive tapes, etc. Label products In particular, the biodegradable release sheet that reduces the environmental load and prevents environmental pollution during disposal after use. And label products using the same About.
[0002]
[Prior art]
Conventionally, seal label, double-sided adhesive tape, etc. Label products Release sheet that temporarily covers the pressure-sensitive adhesive layer before use (known as release paper, separator, etc., but since plastic film is also used, it is called release sheet below) In use, the release sheet is peeled off, and the adhesive layer is attached to the adherend while applying pressure to the adherend. Widely used.
[0003]
The release sheet is composed of, for example, glassine paper, kraft paper, or a plastic film such as polyester, polyethylene, polypropylene, etc., on which silicon is applied as a release agent. The main component is —OH group (condensation type) or —CH═CH as a functional group. ₂ It consists of a linear polydimethylsiloxane having a group (addition type) and a polymethylhydrogensiloxane that crosslinks it. These two components are diluted together with the catalyst to 2 to 15% with toluene or the like, applied onto the substrate, dried, and further baked to form a release sheet. In addition, when normal paper such as fine paper is used as a base material, a material obtained by extruding a polyethylene layer onto a paper base material as a sealing layer for preventing penetration of expensive silicone which is easy to permeate is often used.
[0004]
[Problems to be solved by the invention]
However, in the structure of the above conventional release sheet, the polyester, polyethylene, polypropylene film, etc. as the base material, the release agent layer applied thereto, or the polyethylene as the sealing layer are discarded after use. In the case of (incineration treatment, landfill disposal), there has been a problem that the load on the environment increases and there is a risk of causing environmental pollution. Furthermore, the conventional release sheet has not been printed or the like, has a poor design and tastelessly dried, and has only been discarded as having no value after peeling off the seal label or the like.
[0005]
The present invention solves the problems of the prior art, and the problem is to take advantage of the ease of disposal of the biodegradable resin to reduce the burden on the environment at the time of disposal after use, The object is to provide a biodegradable release sheet that prevents environmental pollution. Another object of the present invention is to provide a biodegradable release sheet that can be reused by adding design and the like.
[0006]
[Means for Solving the Problems]
In order to achieve the above object in the present invention, first, in the invention of claim 1, a biodegradable plastic film or paper is used as a base material, and one side thereof is provided. A printing layer having a biodegradability, which is formed of a printing ink comprising a polylactic acid segment and a polyglycerin segment and having a main binder of an aliphatic polyester containing 80 mol% or more of lactic acid residues in the polylactic acid segment, is applied, Coating the printed layer Polylactic acid resin having a polylactic acid segment and a polyglycerin segment, and organic solvent-soluble polysaccharide or polylactic acid resin having a mixing ratio of 5 to 40 parts by weight of organic solvent-soluble polysaccharide to 100 parts by weight of polylactic acid resin A biodegradable release agent layer formed of a release agent composed of a mixture with a polyfunctional isocyanate having a mixing ratio of 0.5 to 20 parts by weight of a polyfunctional isocyanate with respect to 100 parts by weight. A biodegradable release sheet characterized by the above.
[0007]
According to the first aspect of the present invention, except for paper, in place of a conventional plastic film such as polyester, polyethylene, polypropylene, etc., a biodegradable film is used as a base material, and in place of a conventional silicone resin, biodegradability is achieved. Because it has a release agent layer, the substrate and release agent layer are exposed to various bacteria (degradable bacteria) and decomposed when discarded after use, reducing the environmental load related to waste, and environmental pollution. The biodegradable release sheet can be prevented. In addition, even when the base material is paper, the release agent layer has biodegradability, so it is decomposed together with the release agent layer without hindering the biodegradability of the paper. It is effective.
[0009]
Furthermore, according to the invention of claim 1, A biodegradable printing layer formed of a printing ink comprising a polylactic acid segment and a polyglycerin segment, the main component of which is an aliphatic polyester containing 80 mol% or more of lactic acid residues in the polylactic acid segment is coated. Have As a release agent layer having biodegradability, a polylactic acid resin having a polylactic acid segment and a polyglycerin segment, and 5 to 40 parts by weight of an organic solvent-soluble polysaccharide with respect to 100 parts by weight of the polylactic acid resin Because it uses a mixture of polyfunctional isocyanate having a mixing ratio of 0.5 to 20 parts by weight of polyfunctional isocyanate to 100 parts by weight of organic solvent-soluble polysaccharide or polylactic acid-based resin, easy peelability and heat resistance Have Prevents printing layer blocking and printing layer transition In addition, when disposing of the product after use, the film or paper having the release agent layer is exposed to various bacteria (degradable bacteria) together with the release agent layer and decomposed to reduce the environmental load related to waste. The biodegradable release sheet can prevent further environmental pollution. In addition, since the polylactic acid-based resin, which is easy to form a film, is used for the release agent layer, a polyethylene layer as a sealing layer is unnecessary even when ordinary paper such as fine paper is used for the base material. It is possible to provide a biodegradable release sheet that simplifies the process and reduces the environmental load associated with waste, and prevents further environmental pollution.
[0010]
In the invention of claim 2, A polyhydroxy acid-based polyester comprising a biodegradable plastic film or paper as a base material and containing a sulfonate-containing structure represented by the following formula (1) and / or (2) in a molecular chain on one side; A biodegradable printing layer comprising a mixture with a solvent-soluble polysaccharide or polyfunctional isocyanate is applied, A mold release agent comprising a mixture of a polyhydroxy acid-based polyester containing a sulfonate-containing structure represented by the formula (1) and / or (2) in the molecular chain and an organic solvent-soluble polysaccharide or polyfunctional isocyanate. Formed A release agent layer having high biodegradability is applied. It is characterized by being Life This is a decomposable release sheet.
[Chemical 7]

[In the formula (1), X represents an alkyl group having 20 or less carbon atoms, a cycloalkyl group, an aryl group, an arylalkyl group, or hydrogen, hydroxyl group, nitro group, amino group, acyl group, sulfonic acid group, alkoxyl group, and halogen. M represents lithium, sodium, potassium or an amine represented by the following formula (3). Moreover, m1 is an integer of 0-3, m2 is an integer of 1-4, and m1 + m2 satisfies the relationship of 1 ≦ m1 + m2 ≦ 4. N1 represents an integer of 1 or more. ]
[Chemical 8]

[In Formula (2), R ¹ Represents an alkylidene group having 20 or less carbon atoms, and M represents lithium, sodium, potassium or an amine represented by the following formula (3). ]
[Chemical 9]

[In Formula (3), R ² , R ^Three , R ^Four And R ^Five Each independently represents hydrogen, an alkyl group, a phenyl group or a benzyl group. ]
[0011]
According to the invention of claim 2 above, Biodegradability comprising a mixture of a polyhydroxy acid polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in the molecular chain and an organic solvent-soluble polysaccharide or polyfunctional isocyanate Having a printed layer covering As a biodegradable release agent layer, a polyhydroxy acid polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in a molecular chain, an organic solvent-soluble polysaccharide, Because it uses a mixture with polyfunctional isocyanate, it has easy peelability and heat resistance. Prevents blocking by the printing layer and transfer of the printing layer. And at the time of disposal after use, the film or paper having this release agent layer is decomposed by being exposed to various germs (degradable bacteria) together with the release agent layer, reducing the environmental load related to waste, A biodegradable release sheet that prevents further environmental pollution can be obtained. Also, since the release agent layer uses a polyhydroxy acid-based polyester resin that includes the sulfonate-containing structure in the molecular chain, which facilitates film formation, even when using normal paper such as fine paper as the base material, A polyethylene layer as a stop layer is unnecessary, and therefore, it is possible to provide a biodegradable release sheet that simplifies the process and reduces the environmental load related to waste and prevents further environmental pollution.
[0013]
Claims above 1 According to the invention of On one side of Biodegradable release agent layer Covered with A biodegradable printing layer formed of a printing ink comprising a polylactic acid segment and a polyglycerin segment, the main component of which is an aliphatic polyester containing 80 mol% or more of lactic acid residues in the polylactic acid segment is applied. Shall be Depending on the situation, the pattern (for example, an infant sticker that displays an animal picture when the seal is peeled off) and various information (for example, “This is an environmentally friendly biodegradable release that decomposes in the soil. Films and papers that have a printable layer that is designed to be reusable and can be reused and disposed of after use of these biodegradable release sheets. A biodegradable release sheet that is decomposed by being exposed to various germs (degradable bacteria) together with the printing layer and the release agent layer, reducing the environmental load related to waste, and preventing further environmental pollution, can do.
[0017]
Claims above 2 According to the invention, as a main binder of a printing ink layer provided on one side of a biodegradable film or paper, the sulfonate-containing structure represented by the above formula (1) and / or (2) is used as a molecular chain. Since a mixture of the polyhydroxy acid polyester and the organic solvent-soluble polysaccharide or polyfunctional isocyanate is used, the film or paper having these printed layers is used as a release agent. The biodegradable release sheet that is decomposed by being exposed to various germs (degradable bacteria) together with the layer, reduces the environmental load related to waste, and prevents further environmental pollution.
[0018]
Claims above 2 In general, printing inks mainly composed of a mixture of a polyhydroxy acid-based polyester resin having a sulfonate-containing structure in a molecular chain and an organic solvent-soluble polysaccharide or polyfunctional isocyanate are suitable for printing (printing). Various auxiliary components are contained in order to ensure suitability. Because of this auxiliary component, when a large number of biodegradable release sheets after printing are stored in a stack, these printing layers tend to cause blocking that adheres to the adjacent biodegradable release sheets. Further, for example, when the adhesive on the seal is temporarily adhered, the printed layer may transfer to the adhesive and contaminate the adhesive.
[0019]
Therefore, in the invention according to claim 1 or 2, 1 Or 2 A mixture of a polylactic acid-based resin having a polylactic acid segment and a polyglycerin segment and an organic solvent-soluble polysaccharide or a polyfunctional isocyanate. Or a mixture of a polyhydroxy acid-based polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in the molecular chain, and an organic solvent-soluble polysaccharide or polyfunctional isocyanate. Easy release and heat-resistant release agent layer prevents long-term storage and transfer by preventing blocking and transfer to adhesives such as adjacent biodegradable release sheets and seal labels. This also serves to improve the reliability of quality.
Furthermore, the claims 3 In the present invention, the above-mentioned claim 1 Or 2 A label product using the biodegradable release sheet according to any one of the above, wherein the release agent layer surface of the biodegradable release sheet is temporarily adhered to the adhesive layer surface applied to the label substrate It is a label product characterized by
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
In the present invention, for example, as shown in the laminated sectional side view of FIG. 1, a biodegradable film is used as a base material (10), and a release agent layer having biodegradability is formed on one side of the base material (10). A biodegradable release sheet (4) that has been subjected to (14), and is provided with a biodegradable printing layer (16) between the substrate (10) and the release agent layer (14); The biodegradable release sheet (4) is, for example, a sealed label (1) in which an adhesive layer (3) is applied to a label sheet (2) as shown in the laminated side sectional view of FIG. The surface of the release agent layer (14) of the biodegradable release sheet (4) is temporarily adhered to the surface of the adhesive layer (3). Further, as shown in the laminated sectional side view of FIG. 3, the seal label (1) is peeled from the surface of the release agent layer (14) of the biodegradable release sheet (4), and the remaining biodegradable release sheet (4) is to be discarded. However, the one provided with the printing layer (16) as described above can be a biodegradable release sheet (4) that can be reused.
[0021]
As the biodegradable film as the substrate (10) according to the present invention, any film can be used, but for reasons such as film forming processability, transparency and biodegradability, a polylactic acid film is used. It can be suitably used. The polylactic acid film starts to be hydrolyzed when both temperature and humidity are maintained under a certain condition. Furthermore, decomposition is promoted by the microorganisms ingesting molecules that have become smaller due to hydrolysis.
[0022]
Therefore, the polylactic acid film does not start to hydrolyze under normal release sheet storage conditions. Therefore, from this point of view, it is possible to supply a biodegradable release sheet with stable quality to the product factory. it can. In addition, since hydrolysis does not start after a product such as a seal label, there is no deterioration in quality even when products are sold in stores. For this reason, it is suitable for the release sheet of the product put on a long-term distribution process. This polylactic acid film is quickly decomposed when left in compost.
[0023]
Examples of the polylactic acid film include Terramac manufactured by Unitika Co., Ltd., Ecologe manufactured by Mitsubishi Plastics Co., Ltd., and Palgreen LC manufactured by Toh Cello Co., Ltd., and the like. These commercially available polylactic acid films are films suitable as biodegradable release sheets for seal labels shown in FIG. 2, for example.
[0024]
The thickness of the polylactic acid film is preferably 5 to 100 μm. Preferably it is 10 to 40 μm, and a relatively thick one is used especially for seal labels, etc., and a relatively thin one is suitable for slips for home delivery and double-sided adhesive tapes, etc. can do.
[0025]
Further, the substrate (10) can be a biodegradable paper. This paper has a basis weight of 50 to 200 g / m. ² Glassine paper, kraft (bleached, semi-bleached, unbleached, etc.) paper, high-quality paper, coated paper, etc. are preferably used. It can be selected according to the application together with the type of paper so that a relatively thin one is suitable for a slip such as a courier or a double-sided adhesive tape.
The
[0026]
Next, the polylactic acid resin used in the release agent layer (14) preferably contains 80 mol% or more of lactic acid residues in the polylactic acid segment. It is desirable to contain a D-lactic acid residue so that the L / D molar ratio is in the range of 1-9. Moreover, it is desirable that the reduced viscosity is in the range of 0.3 to 1.0 dl / g and the glass transition point is in the range of 40 to 60 ° C.
[0027]
Such polylactic acid-based resins are melt-mixed with additives such as lactide and polyglycerin, which are dimers of lactic acid, and heat-opening polymerization in the presence of a heat-opening catalyst, or direct dehydration by heating and decompression. It can be obtained by a polymerization method.
[0028]
Examples of the organic solvent-soluble polysaccharide used in the release agent layer (14) include nitrocellulose, cellulose acetate, and esterified starch.
As a mixing ratio thereof, 5 to 40 parts by weight of organic solvent-soluble polysaccharide is preferable with respect to 100 parts by weight of the polylactic acid resin.
[0029]
Examples of the polyfunctional isocyanate used in the release agent layer (14) include bifunctional isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hydrogenated TDI, and hydrogenated MDI. And trifunctional isocyanates such as hexamethylene diisocyanate trimer.
The mixing ratio of these is preferably 0.5 to 20 parts by weight of polyfunctional isocyanate with respect to 100 parts by weight of polylactic acid resin.
[0030]
Furthermore, as the polyhydroxy acid-based polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) used in the release agent layer (14) in the molecular chain, for example, the above formula It is obtained by copolymerization of a sulfonic acid-containing compound represented by (1) and a hydroxy acid. For example, lactide, which is a dimer of lactic acid, and the sulfonic acid-containing compound are melt-mixed, and a known ring-opening polymerization is performed. Examples thereof include a method of performing heat ring-opening polymerization using a catalyst such as octylic acid and aluminum acetylacetonate, and a method of performing direct dehydration polycondensation by heating and reduced pressure.
[0031]
The polyhydroxy acid-based polyester obtained as described above has a sulfonate concentration of 5 to 100 equivalents / 10 in the polyester. ⁶ g is desirable, and when the polyhydroxy acid-based polyester is a lactic acid-based polyester, it is desirable that the lactic acid-based polyester contains 80 mol% or more of lactic acid residues.
When the lactic acid-based polyester contains an L-lactic acid residue and a D-lactic acid residue, the number of moles of L-lactic acid residues (L) and the number of moles of D-lactic acid residues (D) It is desirable that the molar ratio (L / D) is in the range of 1-9. As lactic acid, any of L-lactic acid, D-lactic acid, and DL-lactic acid can be used.
[0032]
The reduced viscosity of the polyhydroxy acid polyester obtained as described above is preferably in the range of 0.3 to 1.5 dl / g, and the glass transition point is in the range of 35 to 60 ° C. It is preferable.
[0033]
The release agent layer (14) can be obtained by printing or coating by dissolving or dispersing in a suitable organic solvent. As the organic solvent, for example, toluene, methyl ethyl ketone, ethyl acetate or the like can be used.
[0034]
Moreover, in this invention, as shown, for example in FIG. 1, the printing layer (16) which has biodegradability between the base material (10) which has biodegradability, and the mold release agent layer (14) which has biodegradability. The biodegradable release sheet (4) to which is applied.
[0035]
As this printing layer (16), printing mainly comprising a colorant and a binder for fixing the colorant on the biodegradable film, and added with various auxiliary components for improving ink suitability (printability). It can be composed of ink.
As the colorant, a color pigment or a dye can be used, but a pigment is preferable from the viewpoint of its light resistance.
[0036]
As the aliphatic polyester comprising a polylactic acid segment and a polyglycerin segment used as a binder constituting the printing ink, it is desirable that the polylactic acid segment contains 80 mol% or more of lactic acid residues. It is desirable to contain a lactic acid residue and a D-lactic acid residue so that the L / D molar ratio is in the range of 1-9. The degree of polymerization of the polyglycerin segment is preferably in the range of 3-20. The aliphatic polyester desirably has a reduced viscosity of 0.3 to 1.0 dl / g and a glass transition point of 40 to 60 ° C.
[0037]
Such aliphatic polyesters are obtained by melt-mixing lactic acid and polyglycerin into lactide, which is a dimer of lactic acid, and heat-opening polymerization using a known ring-opening polymerization catalyst, or by direct dehydration by heating and decompression. It can be obtained by a polymerization method. Moreover, after manufacturing high molecular weight polylactic acid and a lactic acid segment, it can also obtain by making a polyglycerol segment react using a urethane group, an epoxy group, etc. As lactic acid, L-lactic acid, D-lactic acid, DL-lactic acid and the like can be used.
[0038]
Furthermore, as the polyhydroxy acid-based polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) used as a binder in the molecular chain, the section of the release agent layer (14). Since it is the same as that described in, it is omitted.
[0039]
Next, as the above-mentioned various auxiliary components in the printing ink, a wax that gives the printing layer (16) friction resistance and slipperiness, a flexibility to the printing layer (16), and a biodegradable film of the ink Examples thereof include a plasticizer and an antifoaming agent that improve transferability to water, a pigment dispersant, a viscosity modifier, a film modifier, and a drying modifier. An appropriate amount of these auxiliary components may be added according to the printing method and conditions.
These printing inks can be printed by gravure printing, for example. It is also possible to construct a color printing layer (16) by overprinting multicolor printing inks.
[0040]
As described above, the release agent layer (14) according to the present invention that is provided so as to cover the print layer (16) is easy to peel and relatively heat-resistant, and therefore depends on the print layer (16). It also serves to prevent blocking and metastasis.
[0041]
The biodegradable release sheet (4) according to the present invention is used, for example, as shown in FIG. 2 for a seal label (1), for an adhesive voucher such as a courier, for a double-sided adhesive tape, or an envelope, etc. It can be suitably used as a cover for an adhesive provided at the sealing opening.
[0042]
Next, the present invention will be described more specifically by way of an example.
As shown in FIG. 1, a polylactic acid film manufactured by Unitika Ltd. was used as the biodegradable film as the substrate (10). The melting point of this polylactic acid film was 170 ° C., and the film was biaxially stretched to a thickness of 25 μm.
[0043]
Next, the printing layer (16) was formed in the back surface side (upper surface in drawing) of the base material (10) using gravure printing. The ink applied to the printing layer (16) was prepared by mixing 10 parts by weight of a color pigment and 200 parts by weight of propyl acetate as an organic solvent with 100 parts by weight of a binder composed of an aliphatic polyester composed of a polylactic acid segment and a polyglycerin segment. Various auxiliary components are added to adjust the printability.
[0044]
The binder is synthesized by the following method. That is, 1000 parts of DL lactide, 10 parts of polyglycerin having a polymerization degree of 10 and 1 part by weight of aluminum acetyl acetate as a ring-opening polymerization catalyst are charged into a flask and heated and melted in a nitrogen atmosphere at 180 ° C. for 3 hours. The above binder was produced by ring-opening polymerization by distilling away residual lactide under reduced pressure.
The lactic acid residue in this binder was 99 mol%, the L / D molar ratio of L-lactic acid residue to D-lactic acid residue was 1, the reduced viscosity was 0.49 dl / g, and the glass transition point was 49 ° C. It was.
[0045]
Next, this print layer (16) was coated and a release agent layer (14) was applied. This release agent layer (14) is obtained by mixing 20 parts by weight of an organic solvent-soluble nitrocellulose with 100 parts by weight of a polylactic acid resin having a polylactic acid segment and a polyglycerin segment. Then, it was applied by a gravure printing method.
This polylactic acid resin is synthesized by the following method. That is, 1000 parts by weight of DL lactide, 10 parts by weight of polyglycerin having a polymerization degree of 10 and 1 part by weight of aluminum acetyl acetate as a ring-opening polymerization catalyst were charged into a flask and heated and melted in a nitrogen atmosphere at 180 ° C. for 3 hours. Ring-opening polymerization, and the residual lactide was distilled off under reduced pressure to produce the binder.
In this polylactic acid resin, the lactic acid residue is 99 mol%, the L-lactic acid residue and the D-lactic acid residue have an L / D molar ratio of 1, the reduced viscosity is 0.49 dl / g, and the glass transition point is 49. ° C.
[0046]
Using the biodegradable release sheet (4) obtained in this way, as shown in FIG. 2, the label label (1) is provided with a pressure-sensitive adhesive layer (3) on the back surface of the label paper (2). The product was temporarily adhered.
[0047]
When using the label product obtained above, the seal label (1) was peeled from the biodegradable release sheet (4), and the biodegradability of the remaining biodegradable release sheet (4) was confirmed. All of the substrate (10) film, the printing layer (16), and the release agent layer (14) exhibited good biodegradability and decomposed within a short period of time.
[0048]
【The invention's effect】
Since this invention is the above structure, there exist the following effects.
That is, in the first aspect of the invention, except for paper, instead of the conventional plastic film such as polyester, polyethylene, polypropylene, etc., the biodegradable film is used as a base material, and the conventional silicone resin is used instead of the biodegradable film. Therefore, when disposing of the substrate after use, the base material and the release agent layer are exposed to various bacteria (degradable bacteria) and decomposed, reducing the environmental load related to waste, A biodegradable release sheet that prevents contamination can be obtained. In addition, even when the base material is paper, the release agent layer has biodegradability, so it is decomposed together with the release agent layer without hindering the biodegradability of the paper. It is effective.
[0049]
In the invention of claim 1 above, A biodegradable printing layer formed of a printing ink comprising a polylactic acid segment and a polyglycerin segment, the main component of which is an aliphatic polyester containing 80 mol% or more of lactic acid residues in the polylactic acid segment is coated. Have The biodegradable release agent layer has a polylactic acid resin having a polylactic acid segment and a polyglycerin segment, and 5 to 40 parts by weight of organic solvent-soluble polysaccharide with respect to 100 parts by weight of the polylactic acid resin. Because it uses a mixture of polyfunctional isocyanate having a mixing ratio of 0.5 to 20 parts by weight of polyfunctional isocyanate to 100 parts by weight of organic solvent-soluble polysaccharide or polylactic acid-based resin, easy peelability and heat resistance Have Prevents printing layer blocking and printing layer transition In addition, when disposing of the product after use, the film or paper having the release agent layer is exposed to various bacteria (degradable bacteria) together with the release agent layer and decomposed to reduce the environmental load related to waste. The biodegradable release sheet can prevent further environmental pollution. In addition, since the polylactic acid-based resin, which is easy to form a film, is used for the release agent layer, a polyethylene layer as a sealing layer is unnecessary even when ordinary paper such as fine paper is used for the base material. It is possible to provide a biodegradable release sheet that simplifies the process and reduces the environmental load associated with waste, and prevents further environmental pollution.
[0050]
In the invention of claim 2 above, Biodegradability comprising a mixture of a polyhydroxy acid polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in the molecular chain and an organic solvent-soluble polysaccharide or polyfunctional isocyanate Cover the printed layer with A polyhydroxy acid polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in a molecular chain, an organic solvent-soluble polysaccharide or Because it uses a mixture with functional isocyanate, it has easy peelability and heat resistance. Prevents blocking by the printing layer and transfer of the printing layer. And at the time of disposal after use, the film or paper having this release agent layer is decomposed by being exposed to various germs (degradable bacteria) together with the release agent layer, reducing the environmental load related to waste, A biodegradable release sheet that prevents further environmental pollution can be obtained.
Also, since the release agent layer uses a polyhydroxy acid-based polyester resin that includes the sulfonate-containing structure in the molecular chain, which facilitates film formation, even when using normal paper such as fine paper as the base material, A polyethylene layer as a stop layer is unnecessary, and therefore, it is possible to provide a biodegradable release sheet that simplifies the process and reduces the environmental load related to waste and prevents further environmental pollution.
[0051]
In addition, the above claims 1 or 2 In the present invention, the substrate On one side of Biodegradable release agent layer Covered with Printed with biodegradable printing layer Shall be By providing a biodegradable release sheet that has been given a design by design and various information, and can be reused. A biodegradable release sheet that reduces the environmental load associated with waste and prevents further environmental pollution by exposing paper and other materials together with the print layer and release agent layer to decompose them. It can be.
[0052]
Furthermore, the claim 1 In the present invention, an aliphatic containing 80% or more of lactic acid residues in a polylactic acid segment comprising a polylactic acid segment and a polyglycerin segment as a main binder of a printing ink layer provided on one side of a biodegradable film or paper Since polyester is used, when it is discarded after use, films and papers with these printed layers are decomposed by being exposed to various germs (degradable bacteria) together with this printed layer and release agent layer, and are related to waste. It can be a biodegradable release sheet that reduces the environmental load and prevents further environmental pollution.
[0053]
Furthermore, the above claims 2 In the invention, the sulfonate-containing structure represented by the above formula (1) and / or (2) is included in the molecular chain as the main binder of the printing ink layer provided on one side of the biodegradable film or paper. Since a mixture of a polyhydroxy acid polyester and an organic solvent-soluble polysaccharide or polyfunctional isocyanate is used, at the time of disposal after use, a film or paper having these printed layers is used as a printed layer and a release agent layer. At the same time, the biodegradable release sheet is decomposed by being exposed to various germs (degradable bacteria), reducing the environmental load related to waste, and preventing further environmental pollution.
[0054]
In the invention according to claim 1 or 2, the above claim 1 Or 2 A mixture of a polylactic acid-based resin having a polylactic acid segment and a polyglycerin segment and an organic solvent-soluble polysaccharide or a polyfunctional isocyanate. Or a mixture of a polyhydroxy acid-based polyester containing a sulfonate-containing structure represented by the above formula (1) and / or (2) in the molecular chain, and an organic solvent-soluble polysaccharide or polyfunctional isocyanate. Easy release and heat-resistant release agent layer prevents these printing layers from blocking or transferring to the adhesive of adjacent biodegradable release sheet or label product, This also serves to improve the reliability of quality.
[0055]
Therefore, the present invention is a release sheet used for label products such as seal labels, courier slips, double-sided adhesive tapes, Prevent blocking by the printing layer and transfer to other printing layers, Messenger for As a biodegradable release sheet that reduces the environmental load and prevents environmental pollution during later disposal, it exhibits excellent practical effects.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an example of a biodegradable release sheet of the present invention in a side section.
FIG. 2 is an explanatory view showing an example of a product using the biodegradable release sheet of the present invention in a side section.
FIG. 3 is an explanatory view showing a case example of a product using the biodegradable release sheet of the present invention in a side section.
[Explanation of symbols]
1 ... Seal label
2. Label paper
3. ... adhesive layer
4 ... biodegradable release sheet
10 ... Base material
14 ... Release agent layer
16. Print layer

Claims (3)

The main binder is an aliphatic polyester composed of a biodegradable plastic film or paper, which is composed of a polylactic acid segment and a polyglycerin segment on one side and contains 80 mol% or more of lactic acid residues in the polylactic acid segment. A biodegradable printing layer formed with a printing ink is applied, and a polylactic acid resin having a polylactic acid segment and a polyglycerin segment coated with the printing layer, and organic with respect to 100 parts by weight of the polylactic acid resin. Mixture of organic solvent-soluble polysaccharide or polylactic acid-based resin with polyfunctional isocyanate 0.5 to 20 parts by weight with respect to 100 parts by weight of organic solvent-soluble polysaccharide or polylactic acid resin with mixing ratio 5 to 40 parts by weight of solvent-soluble polysaccharide A biodegradable release agent layer formed from a release agent comprising: Gender release sheet. A polyhydroxy acid-based polyester comprising a biodegradable plastic film or paper as a base material and containing a sulfonate-containing structure represented by the following formula (1) and / or (2) in a molecular chain on one side; printing layer having biodegradability consisting of a mixture of a solvent-soluble polysaccharide or polyfunctional isocyanate is applied, sulfonates represented by the following following formula (1) and / or (2) to cover the printed layer A biodegradable release agent layer formed of a release agent comprising a mixture of a polyhydroxy acid-based polyester having a contained structure in the molecular chain and an organic solvent-soluble polysaccharide or polyfunctional isocyanate is applied . biodegradable release sheet said.

[In the formula (1), X represents an alkyl group having 20 or less carbon atoms, a cycloalkyl group, an aryl group, an arylalkyl group, or hydrogen, a hydroxyl group, a nitro group, an amino group, an acyl group, an sulfonic acid group, an aic acid group, An alkoxyl group and a halogen are shown, M represents lithium, sodium, potassium, or an amine represented by the following formula (3). Moreover, m1 is an integer of 0-3, m2 is an integer of integer 4 of 1-4, and m1 + m2 satisfies the relationship of 1 ≦ m1 + m2 ≦ 4. N1 represents an integer of 1 or more. ]

[In the formula (2), R ¹ represents an alkylidene group having 20 or less carbon atoms, and M represents lithium, sodium, potassium, or an amine represented by the following formula (3). ]

[In the formula (3), R ² , R ³ , R ⁴ and R ⁵ each independently represent hydrogen, an alkyl group, a phenyl group or a benzyl group. ] It is a label product using the biodegradable release sheet according to claim 1 or 2 , wherein the release agent layer surface of the biodegradable release sheet is applied to a label substrate. A label product characterized by being temporarily adhered to the layer surface.

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