JP4284939B2

JP4284939B2 - Decorative molding method for paper container material and decorative paper container

Info

Publication number: JP4284939B2
Application number: JP2002215035A
Authority: JP
Inventors: 実永江
Original assignee: Toppan Inc
Current assignee: Toppan Inc
Priority date: 2002-07-24
Filing date: 2002-07-24
Publication date: 2009-06-24
Anticipated expiration: 2022-07-24
Also published as: JP2004051206A

Description

【０００１】
【発明の属する技術分野】
本発明は、紙容器用材料の加飾成型方法及びその方法で加飾成型した紙容器用材料からなる紙容器に関するものである。
【０００２】
【従来の技術】
従来、紙容器に使用する通常の紙容器用材料を加飾成型する方法として、各種形状の一対の金型で絞り成型し、表面を凹凸状に加飾成型する方法が多く実施されている。しかし、この方法で加飾成型すると、紙容器用材料が有している破断強度伸びが小さい為にその凹凸状の高さは２．０ｍｍ程度が限界であり、それ以上の高さに加飾成型すると紙容器用材料が破れてしまっていた。
【０００３】
【発明が解決しようとする課題】
本発明の課題は、２．０ｍｍ以上の高さの凹凸状の加飾成型が可能な紙容器用材料の加飾成型方法及びその方法で加飾成型した紙容器用材料からなる紙容器を提供することにある。
【０００４】
【課題を解決するための手段】
本発明の請求項１に係る発明は、発泡開始温度７０〜２００℃、発泡倍率（直径）２〜５０倍の熱発泡性カプセル１０〜４０重量％を含有する熱発泡性紙層の単層構成若しくは前記熱発泡性紙層の少なくとも一方の面に熱可塑性樹脂層を積層した多層構成の紙容器用材料を、上側金型と下側金型のクリアランスの長さが異なる形状の金型形状をしてなり、熱発泡性カプセルの発泡開始温度若しくは熱可塑性樹脂層の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した金型で挟んで加熱加圧し、紙容器用材料の金型で加圧されていない部分を発泡させ、厚み方向に膨張させることを特徴とする紙容器用材料の加飾成型方法である。
【０００５】
本発明の請求項２に係る発明は、上記請求項１記載の加飾成型方法で加飾成型した紙容器用材料からなることを特徴とする加飾紙容器である。
【０００６】
【作用】
本発明によれば、発泡開始温度７０〜２００℃、発泡倍率（直径）２〜５０倍の熱発泡性カプセル１０〜４０重量％を含有する熱発泡性紙層の単層構成若しくは前記熱発泡性紙層の少なくとも一方の面に熱可塑性樹脂層を積層した多層構成の紙容器用材料を、上側金型と下側金型のクリアランスの長さが異なる形状の金型形状をしてなり、熱発泡性カプセルの発泡開始温度若しくは熱可塑性樹脂層の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した金型で挟んで加熱加圧し、紙容器用材料の金型で加圧されていない部分に発泡気泡を生成させて、その部分を膨張させる方法で加飾成型するので、加飾成型時に使用した紙容器用材料が金型形状に沿って加飾成型され、深く加飾成型しても破れが発生しない。従って、この方法で加飾成型した紙容器用材料を用いた加飾紙容器は商品性も優れ、機能も良好である。
【０００７】
【発明の実施の形態】
本発明の紙容器用材料の加飾成型方法及びその方法で加飾成型した紙容器用材料を用いた加飾紙容器を、実施の形態に沿って以下に詳細に説明する。
【０００８】
図１（ａ）は使用する金型（３０）の構造図であり、金型（３０）は上側金型（３０ａ）及び下側金型（３０ｂ）からなっており、上側金型（３０ａ）は内側に高さ（ｄ₁）の１個の凹部（４０ａ）を有しており、下側金型（３０ｂ）は同様に内側に高さ（ｄ₂）の１個の凹部（４０ｂ）を有しており、成型時に上側金型（３０ａ）と下側金型（３０ｂ）のクリアランスの長さに差異が生じる形状になっている。
【０００９】
図１（ｂ）は前記の上側金型（３０ａ）と下側金型（３０ｂ）の間に紙容器用材料（１１）を挿入した状態を示す説明図であり、紙容器用材料（１１）に使用した熱発泡性カプセル（２）の発泡開始温度若しくは熱可塑性樹脂層（３）の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した上側金型（３０ａ）及び下側金型（３０ｂ）で紙容器用材料（１１）を挟み込み、両側から圧力（５０）を加えて加熱加圧する。その時、上側金型（３０ａ）の凹部（４０ａ）及び下側金型（３０ｂ）の凹部（４０ｂ）の内側部分と紙容器用材料（１１）表面とのに空間が生じ、その空間部分の紙容器用材料（１１）中の熱発泡性カプセル（２）が発泡し、図１（ｃ）に示すような状態で発泡気泡（４）を生成し、紙容器用材料（１１）が凹部（４０ａ）及び凹部（４０ｂ）の形状に沿って厚み方向に膨張する。一方、凹部（４０ａ、４０ｂ）以外の部分の紙容器用材料（１１）中の熱発泡性カプセル（２）は一度発泡するが、上側金型（３０ａ）及び下側金型（３０ｂ）の内側の平坦部で加圧されているので、紙容器用材料（１１）表面との間に空間がなく、発泡気泡（４）が消滅し、その部分の紙容器用材料（１１）は厚み方向に膨張しない。加飾成型後は圧力（５０）を取り除き、加飾成型した紙容器用材料（２０）を取り出す。
【００１０】
図２（ａ）は他の例に使用する金型（３１）の構造図であり、金型（３１）は上側金型（３１ａ）及び下側金型（３１ｂ）からなっており、上側金型（３１ａ）は内側に高さ（ｄ₃）の凹部（４１ａ）と高さ（ｄ₄）の凹部（４２ａ）を有しており、下側金型（３１ｂ）は同様に内側に高さ（ｄ₄）の凸部（４２ｂ）を有している。前記凹部（４２ａ）と凸部（４２ｂ）は同一形状で雄雌になっている。さらに、高さ（ｄ₄）はｄ₄＜ｄ₃になるように設計されており、加圧された時に凹部（４２ａ）及び凸部（４２ｂ）の内側部分と紙容器用材料との間には空間が出来ないようになっている。
【００１１】
図２（ｂ）は前記の上側金型（３１ａ）及び下側金型（３１ｂ）の間に紙容器用材料（１１）を挿入した状態を示す説明図であり、紙容器用材料（１１）に使用した熱発泡性カプセル（２）の発泡開始温度若しくは熱可塑性樹脂層（３）の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した上側金型（３１ａ）、下側金型（３１ｂ）で紙容器用材料（１１）を挟み込み、両側から圧力（５０）を加えて加熱加圧する。その時、上側金型（３１ａ）の凹部（４１ａ）の内側部分と紙容器用材料（１１）表面とのに空間が生じ、その空間部分の紙容器用材料（１１）中の熱発泡性カプセル（２）が発泡し、図２（ｃ）に示すような状態で発泡気泡（４）を生成し、紙容器用材料（１１）が凹部（４１ａ）の形状に沿って厚み方向に膨張する。一方、凹部（４１ａ）以外の部分の紙容器用材料（１１）中の熱発泡性カプセル（２）は一度発泡するが、上側金型（３１ａ）と下側金型（３１ｂ）で加圧され、紙容器用材料（１１）表面との間に空間がない為に発泡気泡（４）が消滅し、その部分の紙容器用材料（１１）は厚み方向に膨張しない。加飾成型後は圧力（５０）を取り除き、加飾成型した紙容器用材料（２１）を取り出す。
【００１２】
前記加飾成型時の金型（３０、３１）の温度は、紙容器用材料に使用した熱発泡性カプセル（２）の発泡開始温度若しくは熱可塑性樹脂層（３）に使用した樹脂の分子が運動し始めるガラス転移点温度のいずれか高い方の温度以上に設定することにより、良好な発泡性、加飾成型性が得られる。
【００１３】
図３（ａ）は本発明の紙容器用材料の加飾成型方法で使用する紙容器用材料の一例を示す側断面図であり、発泡開始温度７０〜２００℃、発泡倍率（直径）２〜５０倍の熱発泡性カプセル（２）１０〜４０重量％を含有する熱発泡性紙層（１）の単層構成からなっており、（ｂ）は紙容器用材料の他の例を示す側断面図であり、前記熱発泡性紙層（１）の一方の面に熱可塑性樹脂層（３）を積層した二層構成からなっており、（ｃ）は紙容器用材料の他の例を示す側断面図であり、前記熱発泡性紙層（１）の両面に熱可塑性樹脂層（３）を積層した三層構成からなっている。
【００１４】
前記熱発泡性カプセル（２）は、アクリル樹脂等の樹脂カプセル中にブタン、ペンタン等の発泡剤を内包したもので、発泡開始温度は７０〜２００℃の範囲で、発泡倍率（直径）２〜５０倍のものを使用する。７０℃未満のものを使用するとパルプに内添し、抄紙する段階で発泡してしまい、２００℃を超えると加飾成型時に金型の温度を高くしなければならないので良くない。発泡倍率（直径）２倍未満のものを使用すると加飾成型時に十分な紙容器用材料の膨張が得られないので良くない。５０倍を超えると紙容器用材料として強度等の点で不足になり、良くない。前記発泡倍率（直径）とは、熱発泡性カプセルが無荷重の時に発泡したカプセルの直径の倍率である。
【００１５】
前記熱可塑性樹脂層（３）に使用する樹脂は、成型性を有する樹脂であれば特に限定されないが、例えば、ナイロン樹脂、ポリオレフィン系樹脂、ポリエステル系樹脂等の樹脂が好ましい。厚さは５μｍ〜１００μｍの範囲が好ましい。
【００１６】
前記熱可塑性樹脂層（３）の積層方法は、前記樹脂を公知の溶融押出ラミネート法で直接積層するか又は前記樹脂からなる無延伸フィルムを接着剤等を介してドライラミネート法で積層する。
【００１７】
図４（ａ）は本発明の加飾成型方法で加飾成型した紙容器用材料の一例の側断面図であり、加飾成型された紙容器用材料（２０）は上側金型（３０ａ）の凹部（４０ａ）及び下側金型（３０ｂ）の凹部（４０ｂ）の部分に発泡気泡（４）を生成し、膨張した部分が高さ（ｄ₁）及び高さ（ｄ₂）で浮き上がって、加飾されており、その他の部分は発泡気泡（４）が消滅して膨張していない。
【００１８】
図４（ｂ）は加飾成型した紙容器用材料の他の例を示す側断面図であり、加飾成型された紙容器用材料（２１）は上側金型（３１ａ）の凹部（４１ａ）の部分のみ発泡気泡（４）を生成し、膨張して高さ（ｄ₃）で浮き上がって、加飾されており、その他の平坦部分は発泡気泡（４）が消滅し、膨張していない。さらに、凹部（４２ａ）及び凸部（４２ｂ）の間の部分も空間が無い為に膨張せず、金型で絞られたのみの状態で高さ（ｄ₄）で浮き上がっている。
【００１９】
前記高さ（ｄ₁）〜（ｄ₃）は１０ｍｍ程度まで可能であり、高さ（ｄ₄）は絞り成型されるだけなので、２ｍｍ程度が限度である。
【００２０】
本発明の加飾紙容器は、本発明の加飾成型方法により加飾した紙容器用材料からなっており、その形状はトレー状、箱状、筒状、袋状、カップ状などの種々の容器がある。
【００２１】
【実施例】
本発明の紙容器用材料の加飾成型方法及び加飾紙容器を具体的な実施例を挙げて説明する。
【００２２】
〈実施例１〉
紙容器用材料として、アクリル樹脂カプセル内にイソブタンを内包した発泡開始温度１１０℃、発泡倍率（直径）６倍の熱発泡性カプセル３０重量％を含有する熱発泡性紙層（坪量２５０ｇ／ｍ²）の単層構成の板紙を使用した。この単層構成の板紙からなる紙容器用材料を、図２（ａ）に示した金型の高さ（ｄ₃）が１０ｍｍ、高さ（ｄ₄）が１ｍｍで、１４０℃に加熱した上側金型（３１ａ）及び下側金型（３１ｂ）で挟んで、圧力３ＭＰａをかけて１０秒間加熱し、凹部（４１ａ）の部分の紙容器用材料を膨張させ、厚み方向に浮き上がらせ、凹部（４２ａ）と凸部（４２ｂ）の部分の紙容器用材料は絞り成型するだけで浮き上がらせる加飾成型方法で加飾した。この加飾成型した紙容器用材料を所定寸法に打ち抜いた後に、長さ１００ｍｍ×幅８０ｍｍ×高さ５０ｍｍの本発明の加飾紙箱を組み立てた。
【００２３】
〈実施例２〉
実施例１において、紙容器用材料として、アクリル樹脂カプセル内にイソブタンを内包した発泡開始温度１１０℃、発泡倍率（直径）６倍の熱発泡性カプセル３０重量％を含有する熱発泡性紙層（坪量２５０ｇ／ｍ²）の単層構成の板紙の両面に厚さ３０μｍの無延伸ポリプロピレン樹脂を積層した三層構成の紙容器用材料を使用した以外は、同様にして加飾成型し、この加飾成型した紙容器用材料を用いて同一寸法の本発明の加飾紙箱を組み立てた。
【００２４】
〈比較例１〉
紙容器用材料として、坪量２５０ｇ／ｍ²の汎用の板紙を使用し、その材料を浮き上げの凹凸の高さが５ｍｍになる形状の一対の金型で、圧力３ＭＰａをかけて、従来の絞り成型法で加飾成型した。この加飾成型した紙容器用材料を所定寸法に打ち抜いた後に、長さ１００ｍｍ×幅８０ｍｍ×高さ５０ｍｍの比較用の加飾紙箱を組み立てた。
【００２５】
〈評価〉
実施例１〜２及び比較例１の紙容器用材料の加飾成型時の成型性及び破れの有無及組み立てた加飾紙箱の商品性、機能を評価した。その結果を表１に示す。
【００２６】
【表１】

【００２７】
表１に示すように、実施例１〜２の加飾成型方法の場合は、紙容器用材料は金型形状に沿って綺麗に成型され、破れもなかった。この方法で加飾成型した紙容器用材料を用いて組み立てた加飾紙箱は商品性及び機能も良好であった。比較例１の加飾成型方法の場合は、加飾成型時に破れが発生した。従って、この方法で加飾成型した紙容器用材料を用いて組み立てた加飾紙箱は商品性及び機能も不良であった。
【００２８】
【発明の効果】
本発明の紙容器用材料の加飾成型方法は、発泡開始温度７０〜２００℃、発泡倍率（直径）２〜５０倍の熱発泡性カプセル１０〜４０重量％を含有する熱発泡性紙層の単層構成若しくは前記熱発泡性紙層の少なくとも一方の面に熱可塑性樹脂層を積層した多層構成の紙容器用材料を、上側金型と下側金型のクリアランスの長さが異なる形状の金型形状をしてなり、熱発泡性カプセルの発泡開始温度若しくは熱可塑性樹脂層の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した金型で挟んで加熱加圧し、紙容器用材料の金型で加圧されていない部分を発泡させ、膨張させて加飾成型するので、加飾成型時に使用した紙容器用材料が金型形状に沿って加飾成型され、深く加飾成型しても破れが発生しない。従って、この方法で加飾成型した紙容器用材料を用いたトレー状、箱状、筒状、袋状等の加飾紙容器は商品性も優れ、機能も良好である。
【図面の簡単な説明】
【図１】（ａ）は本発明の紙容器用材料の加飾成型方法で使用する金型の一例を示す形状図であり、（ｂ）は（ａ）の金型の間に紙容器用材料を挿入した状態を示す説明図であり、（ｃ）は加飾成型した状態を示す説明図である。
【図２】（ａ）は本発明の紙容器用材料の加飾成型方法で使用する金型の他の例を示す形状図であり、（ｂ）は（ａ）の金型の間に紙容器用材料を挿入した状態を示す説明図であり、（ｃ）は加飾成型した状態を示す説明図である。
【図３】（ａ）は本発明の紙容器用材料の加飾成型時方法で使用する紙容器用材料の一例を示す側断面図であり、（ｂ）は紙容器用材料の他の例を示す側断面図であり、（ｃ）は紙容器用材料のさらに他の例を示す側断面図である。
【図４】（ａ）は本発明の加飾成型方法で加飾成型した紙容器用材料の一例の側断面図であり、（ｂ）は加飾成型した紙容器用材料の他の例の側断面図である。
【符号の説明】
１…熱発泡性紙層
２…熱発泡性カプセル
３…熱可塑性樹脂層
４…発泡気泡
１０，１１，１２…紙容器用材料
２０，２１…加飾成型後の紙容器用材料
３０，３１…金型
３０ａ，３０ｂ…上側金型
３１ａ，３１ｂ…下側金型
４０ａ，４０ｂ，４１ａ，４２ａ…凹部
４２ｂ…凸部
５０…圧力
ｄ₁，ｄ₂，ｄ₃，ｄ₄…高さ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a decorative molding method for a paper container material and a paper container made of a paper container material that is decoratively molded by the method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a method for decorating and molding a normal paper container material used for a paper container, many methods have been implemented in which a die is drawn with a pair of molds having various shapes, and the surface is decorated in a concavo-convex shape. However, when decorative molding is performed by this method, the height of the concavo-convex shape is limited to about 2.0 mm because the elongation at break of the paper container material is small. When molded, the paper container material was torn.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a decorative molding method for a paper container material capable of decorative molding with a concavo-convex shape with a height of 2.0 mm or more, and a paper container made of the paper container material decorated with the method. There is to do.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is a single-layer configuration of a thermally foamable paper layer containing 10 to 40% by weight of a thermally foamable capsule having a foaming start temperature of 70 to 200 ° C. and a foaming ratio (diameter) of 2 to 50 times. Alternatively, a paper container material having a multilayer structure in which a thermoplastic resin layer is laminated on at least one surface of the heat-foamable paper layer is formed into a mold shape having a different clearance length between the upper mold and the lower mold. It is sandwiched between molds heated to the higher of the foaming start temperature of the heat-foamable capsules or the glass transition temperature of the resin of the thermoplastic resin layer, and heated and pressed to form a metal for the paper container material. A decorative molding method for a paper container material, characterized in that a portion not pressed by a mold is foamed and expanded in a thickness direction.
[0005]
The invention according to claim 2 of the present invention is a decorative paper container comprising a material for a paper container that is decoratively molded by the decorative molding method according to claim 1.
[0006]
[Action]
According to the present invention, a single-layer configuration of a thermally foamable paper layer containing 10 to 40% by weight of a thermally foamable capsule having a foaming start temperature of 70 to 200 ° C. and a foaming ratio (diameter) of 2 to 50 times, or the thermal foaming property. A paper container material having a multilayer structure in which a thermoplastic resin layer is laminated on at least one surface of a paper layer is formed into a mold shape having different clearance lengths between an upper mold and a lower mold. It is heated and pressed between molds heated to the higher of the foaming start temperature of the expandable capsule or the glass transition temperature of the resin of the thermoplastic resin layer, and then pressed with the mold of the material for the paper container. Since foamed bubbles are generated in the unexposed part and the part is expanded and decorated, the paper container material used at the time of decorative molding is decoratively molded along the mold shape and deeply decorated. But no tearing occurs. Therefore, the decorative paper container using the paper container material decorated and molded by this method has excellent merchantability and functions.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The decorative molding method of the paper container material of the present invention and the decorative paper container using the paper container material decorated and molded by the method will be described in detail below along the embodiments.
[0008]
FIG. 1A is a structural view of a mold (30) to be used. The mold (30) includes an upper mold (30a) and a lower mold (30b), and the upper mold (30a). Has a concave portion (40a) having a height (d ₁ ) on the inner side, and the lower mold (30b) similarly has one concave portion (40b) having a height (d ₂ ) on the inner side. It has a shape that produces a difference in the clearance length between the upper mold (30a) and the lower mold (30b) during molding.
[0009]
FIG.1 (b) is explanatory drawing which shows the state which inserted the paper container material (11) between the said upper metal mold | die (30a) and the lower metal mold | die (30b), and a paper container material (11) The upper mold (30a) and the lower mold heated above the higher one of the foaming start temperature of the thermally foamable capsule (2) used in the above or the glass transition temperature of the resin of the thermoplastic resin layer (3). The paper container material (11) is sandwiched between the molds (30b), and pressure (50) is applied from both sides to heat and press. At that time, a space is created between the inner part of the recess (40a) of the upper mold (30a) and the recess (40b) of the lower mold (30b) and the surface of the paper container material (11), and the paper in the space part The thermally foamable capsule (2) in the container material (11) is foamed to produce foamed bubbles (4) in the state shown in FIG. 1 (c), and the paper container material (11) is in the recess (40a). ) And the recess (40b) in the thickness direction. On the other hand, the thermally foamable capsule (2) in the paper container material (11) other than the recesses (40a, 40b) is once foamed, but inside the upper mold (30a) and the lower mold (30b). Since there is no space between the surface of the paper container material (11) and the foamed bubbles (4) disappear, the paper container material (11) in that portion is in the thickness direction. Does not swell. After the decorative molding, the pressure (50) is removed, and the decorative molded paper container material (20) is taken out.
[0010]
FIG. 2A is a structural diagram of a mold (31) used in another example. The mold (31) includes an upper mold (31a) and a lower mold (31b). type (31a) is height inside the recess (41a) and the height (d ₄₎ has a recess (42a) of the lower die (31b) is height inside similar (d ₃₎ It has a convex part (42b) of (d ₄ ). The concave portion (42a) and the convex portion (42b) have the same shape and are male and female. Furthermore, the height (d ₄ ) is designed so that d ₄ <d ₃ , and when pressed, the height is between the concave portion (42a) and the inner portion of the convex portion (42b) and the paper container material. Can not make space.
[0011]
FIG. 2B is an explanatory view showing a state in which the paper container material (11) is inserted between the upper mold (31a) and the lower mold (31b), and the paper container material (11). Upper mold (31a), lower mold heated above the higher temperature of either the foaming start temperature of the thermally foamable capsule (2) used in the above or the glass transition temperature of the resin of the thermoplastic resin layer (3) The paper container material (11) is sandwiched between the molds (31b), and pressure (50) is applied from both sides to heat and press. At that time, a space is created between the inner part of the recess (41a) of the upper mold (31a) and the surface of the paper container material (11), and the thermally foamable capsule ( 2) foams to produce foamed bubbles (4) in the state shown in FIG. 2 (c), and the paper container material (11) expands in the thickness direction along the shape of the recess (41a). On the other hand, the thermally foamable capsule (2) in the paper container material (11) other than the recess (41a) foams once, but is pressurized by the upper mold (31a) and the lower mold (31b). Since there is no space between the surface of the paper container material (11), the foam bubbles (4) disappear, and the paper container material (11) in that portion does not expand in the thickness direction. After the decorative molding, the pressure (50) is removed, and the decorative-molded paper container material (21) is taken out.
[0012]
The temperature of the mold (30, 31) at the time of the decorative molding is determined by the foaming start temperature of the thermally foamable capsule (2) used for the paper container material or the resin molecules used for the thermoplastic resin layer (3). Good foamability and decorative moldability can be obtained by setting the temperature higher than the higher one of the glass transition temperature at which movement begins.
[0013]
FIG. 3A is a side sectional view showing an example of a paper container material used in the decorative molding method for a paper container material of the present invention, a foaming start temperature of 70 to 200 ° C., a foaming ratio (diameter) of 2 It consists of a single layer configuration of a thermally foamable paper layer (1) containing 50 to 40 times the thermally foamable capsule (2) 10 to 40% by weight, and (b) is a side showing another example of a paper container material It is sectional drawing, and consists of a two-layer structure which laminated | stacked the thermoplastic resin layer (3) on one side of the said heat-foamable paper layer (1), (c) is another example of a paper container material It is side sectional drawing shown, and consists of a three-layer structure which laminated | stacked the thermoplastic resin layer (3) on both surfaces of the said heat-foamable paper layer (1).
[0014]
The heat-foamable capsule (2) is a resin capsule such as an acrylic resin containing a foaming agent such as butane or pentane. The foaming start temperature is in the range of 70 to 200 ° C. and the foaming ratio (diameter) is 2 to 2. Use 50 times. If the one below 70 ° C. is used, it is added to the pulp and foamed at the paper making stage. If it exceeds 200 ° C., the temperature of the mold must be increased during the decorative molding, which is not good. Use of a foaming ratio (diameter) of less than 2 is not good because sufficient expansion of the paper container material cannot be obtained during decorative molding. If it exceeds 50 times, the paper container material is insufficient in terms of strength and the like, which is not good. The expansion ratio (diameter) is a ratio of the diameter of the capsule that is foamed when the thermally foamable capsule is not loaded.
[0015]
The resin used for the thermoplastic resin layer (3) is not particularly limited as long as it is a resin having moldability. For example, resins such as nylon resin, polyolefin resin, and polyester resin are preferable. The thickness is preferably in the range of 5 μm to 100 μm.
[0016]
The thermoplastic resin layer (3) is laminated by directly laminating the resin by a known melt-extrusion laminating method or laminating an unstretched film made of the resin by a dry laminating method through an adhesive or the like.
[0017]
FIG. 4A is a side cross-sectional view of an example of a paper container material that is decoratively molded by the decorative molding method of the present invention. The decoratively molded paper container material (20) is an upper mold (30a). Bubbles (4) are generated in the recess (40a) and the recess (40b) of the lower mold (30b), and the expanded part is lifted at the height (d ₁ ) and the height (d ₂ ). The other part is not expanded by the disappearance of the foamed bubbles (4).
[0018]
FIG. 4 (b) is a side sectional view showing another example of the decoratively molded paper container material, where the decorative molded paper container material (21) is the recess (41a) of the upper mold (31a). The foamed bubble (4) is generated only in the portion of, and is expanded and floated at the height (d ₃ ) to be decorated, and in the other flat portion, the foamed bubble (4) disappears and is not expanded. Further, the portion between the concave portion (42a) and the convex portion (42b) does not expand because there is no space, and is lifted at a height (d ₄ ) while being squeezed with a mold.
[0019]
The heights (d ₁ ) to (d ₃ ) can be up to about 10 mm, and the height (d ₄ ) is only drawn, so the limit is about 2 mm.
[0020]
The decorative paper container of the present invention is made of a paper container material decorated by the decorative molding method of the present invention, and the shape thereof is various, such as a tray shape, a box shape, a cylindrical shape, a bag shape, and a cup shape. There is a container.
[0021]
【Example】
The decorative molding method for a paper container material and the decorative paper container of the present invention will be described with specific examples.
[0022]
<Example 1>
As a material for paper containers, a heat-foamable paper layer (basis weight: 250 g / m) containing 30% by weight of a heat-foamable capsule in which isobutane is encapsulated in an acrylic resin capsule at a foaming start temperature of 110 ° C. and a foaming ratio (diameter) of 6 times ² ) A single-layer board was used. The upper side of the paper container material made of this single-layer board is heated to 140 ° C. with a mold height (d ₃ ) of 10 mm and a height (d ₄ ) of 1 mm shown in FIG. It is sandwiched between the mold (31a) and the lower mold (31b) and heated for 10 seconds under a pressure of 3 MPa to expand the paper container material in the concave portion (41a) and lift it up in the thickness direction. The material for paper containers in the portions 42a) and the convex portions (42b) was decorated by a decorative molding method in which the material was lifted simply by drawing. After the decorative molded paper container material was punched out to a predetermined size, a decorative paper box of the present invention having a length of 100 mm, a width of 80 mm, and a height of 50 mm was assembled.
[0023]
<Example 2>
In Example 1, as a paper container material, a thermally foamable paper layer containing 30% by weight of a thermally foamable capsule having a foaming start temperature of 110 ° C. and a foaming ratio (diameter) of 6 times, in which isobutane is encapsulated in an acrylic resin capsule ( This is decoratively molded in the same manner except that a three-layer paper container material in which a non-stretched polypropylene resin having a thickness of 30 μm is laminated on both sides of a single-layer board having a basis weight of 250 g / m ² ) The decorative paper box of the present invention having the same dimensions was assembled using the decorative molded paper container material.
[0024]
<Comparative example 1>
As a paper container material, a general-purpose paperboard having a basis weight of 250 g / m ² is used, and the material is a pair of molds having a height of unevenness of lifting of 5 mm. The decorative molding was performed by the drawing method. After the decorative molded paper container material was punched out to a predetermined size, a comparative decorative paper box of length 100 mm × width 80 mm × height 50 mm was assembled.
[0025]
<Evaluation>
The moldability at the time of decorative molding of the paper container materials of Examples 1-2 and Comparative Example 1, the presence or absence of tearing, and the merchantability and function of the assembled decorative paper box were evaluated. The results are shown in Table 1.
[0026]
[Table 1]

[0027]
As shown in Table 1, in the case of the decorative molding methods of Examples 1 and 2, the paper container material was neatly molded along the mold shape and was not torn. The decorative paper box assembled by using the paper container material decorated and molded by this method has good merchantability and function. In the case of the decorative molding method of Comparative Example 1, tearing occurred during the decorative molding. Therefore, the decorative paper box assembled using the paper container material decorated and molded by this method has poor merchantability and function.
[0028]
【The invention's effect】
The decorative molding method for a paper container material according to the present invention comprises a foamable paper layer containing 10 to 40% by weight of a thermally foamable capsule having a foaming start temperature of 70 to 200 ° C. and a foaming ratio (diameter) of 2 to 50 times. A paper container material having a single layer structure or a multilayer structure in which a thermoplastic resin layer is laminated on at least one surface of the heat-foamable paper layer, a mold having a shape in which the clearance lengths of the upper mold and the lower mold are different. For a paper container that has a mold shape and is sandwiched with a mold heated to a higher temperature of either the foaming start temperature of the heat-foamable capsule or the glass transition temperature of the resin of the thermoplastic resin layer, whichever is higher Since the part that is not pressed by the mold of the material is foamed and expanded to perform decorative molding, the paper container material used at the time of decorative molding is decorated and molded along the mold shape But no tearing occurs. Therefore, a decorative paper container such as a tray shape, a box shape, a cylindrical shape, and a bag shape using a paper container material that is decorated and molded by this method has excellent merchantability and functions.
[Brief description of the drawings]
FIG. 1 (a) is a shape diagram showing an example of a mold used in the decorative molding method for a paper container material of the present invention, and FIG. 1 (b) is for a paper container between the molds of (a). It is explanatory drawing which shows the state which inserted the material, (c) is explanatory drawing which shows the state which carried out the decorative molding.
FIG. 2A is a shape diagram showing another example of a mold used in the decorative molding method for a paper container material of the present invention, and FIG. It is explanatory drawing which shows the state which inserted the material for containers, (c) is explanatory drawing which shows the state which carried out the decorative molding.
3A is a side sectional view showing an example of a paper container material used in the method for decorative molding of a paper container material of the present invention, and FIG. 3B is another example of a paper container material. (C) is a side sectional view showing still another example of the paper container material.
FIG. 4A is a side sectional view of an example of a paper container material that has been decoratively molded by the decorative molding method of the present invention, and FIG. 4B is another example of a paper container material that has been decoratively molded. It is a sectional side view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Thermo-foamable paper layer 2 ... Thermo-foamable capsule 3 ... Thermoplastic resin layer 4 ... Foamed bubbles 10, 11, 12 ... Paper container material 20, 21 ...

Paper container material

30, 31 after decoration molding ... mold 30a, 30b ... upper mold 31a, 31b ... lower mold 40a, 40b, 41a, 42a ... concave portion 42b ... projection 50 ... pressure _{_{_{d 1, d 2, d 3}}} , d 4 ... height

Claims

発泡開始温度７０〜２００℃、発泡倍率（直径）２〜５０倍の熱発泡性カプセル１０〜４０重量％を含有する熱発泡性紙層の単層構成若しくは前記熱発泡性紙層の少なくとも一方の面に熱可塑性樹脂層を積層した多層構成の紙容器用材料を、上側金型と下側金型のクリアランスの長さが異なる形状の金型形状をしてなり、熱発泡性カプセルの発泡開始温度若しくは熱可塑性樹脂層の樹脂のガラス転移点温度のいずれか高い方の温度以上に加熱した金型で挟んで加熱加圧し、紙容器用材料の金型で加圧されていない部分を発泡させ、厚み方向に膨張させることを特徴とする紙容器用材料の加飾成型方法。A single-layer configuration of a thermally foamable paper layer containing 10 to 40% by weight of a thermally foamable capsule having a foaming start temperature of 70 to 200 ° C. and a foaming ratio (diameter) of 2 to 50 times, or at least one of the thermally foamable paper layers Start of foaming of heat-foamable capsules with a multi-layered paper container material with a thermoplastic resin layer laminated on the surface, with the shape of the upper and lower molds having different clearance lengths. Heat and press with a mold heated to a temperature higher than the glass transition temperature of the resin of the thermoplastic resin layer, whichever is higher, and foam the part not pressed with the mold of the paper container material A method for decorative molding of a paper container material, characterized by expanding in the thickness direction.

前記請求項１記載の加飾成型方法で加飾成型した紙容器用材料からなることを特徴とする加飾紙容器。A decorative paper container comprising a material for a paper container that has been decoratively molded by the decorative molding method according to claim 1.