JP2005088442A

JP2005088442A - Method for manufacturing in-mold foam molded body of thermoplastic resin and molded body

Info

Publication number: JP2005088442A
Application number: JP2003326712A
Authority: JP
Inventors: Ryoji Nakayama; 中山亮二; Kenji Mogami; 最上健二
Original assignee: Kaneka Corp
Current assignee: Kaneka Corp
Priority date: 2003-09-18
Filing date: 2003-09-18
Publication date: 2005-04-07

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-mold foam molded body of a thermoplastic resin which easily makes a mud-crack pattern resulting from a fusion mark of preexpanded particles sufficiently inconspicuous in almost the same molding method as conventionally performed without in-mold foam molding under excess molding conditions and shows an excellent surface profile. <P>SOLUTION: In the method for in-mold foam molding the thermoplastic resin using a molding tool having an almost regular unevenness pattern formed at least in one part of the surface of the molding tool, the recessed part width (a) and recessed part depth (c) of the unevenness pattern on the surface of the mold and the particle diameter D of the preexpanded particle, meet 0.1≤a/D≤1.0 and besides, 0.1≤c/D≤1.0. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

熱可塑性樹脂予備発泡粒子の型内発泡成形体の製造方法および該方法により得られる成形体に関する。さらに詳しくは、表面に予備発泡粒子同士の融着痕に起因する亀甲模様が目立たない、或いは、表面平滑性が良好といった、外観良好な発泡成形体の製造方法および該方法により得られる成形体に関する。 The present invention relates to a method for producing an in-mold foam molded body of thermoplastic resin pre-foamed particles and a molded body obtained by the method. More specifically, the present invention relates to a method for producing a foamed molded article having a good appearance such that the surface of the tortoiseshell pattern due to fusion marks between the pre-foamed particles is not conspicuous or the surface smoothness is good, and a molded article obtained by the method. .

従来、熱可塑性樹脂予備発泡粒子の型内発泡成形体は、原料となる予備発泡粒子を雄雌一対からなる金型内に充填し、水蒸気を吹き込み、予備発泡粒子の軟化と２次発泡により、予備発泡粒子同士を加熱融着することによって成形し、その後、冷却、離型して製造される。しかしながら、かかる方法によって成形された型内発泡成形体は、成形体の外観が良好でないという問題があった。その一因として、予備発泡粒子同士の融着痕に起因する亀甲模様の形成が挙げられる。 Conventionally, an in-mold foam molded body of thermoplastic resin pre-foamed particles is prepared by filling pre-foamed particles as raw materials into a mold consisting of a pair of males and females, blowing steam, softening the pre-foamed particles and performing secondary foaming. The pre-expanded particles are formed by heat-sealing, and then cooled and released from the mold. However, the in-mold foam molded article molded by such a method has a problem that the appearance of the molded article is not good. One reason for this is the formation of a turtle shell pattern resulting from the fusing marks between the pre-expanded particles.

この問題を解決する方法として、金型表面に金網やパンチングメタル、多孔質シートを装着し、成形時にこれらの凹凸模様を成形体表面に転写することにより、亀甲模様を実質的に目立たなくする方法（特許文献１、特許文献２、特許文献３）が開示されている。 As a method of solving this problem, a method of making the turtle shell pattern inconspicuous by attaching a metal net, punching metal, or porous sheet to the mold surface, and transferring these uneven patterns to the molded body surface during molding. (Patent Literature 1, Patent Literature 2, Patent Literature 3) are disclosed.

特許文献１では、平均粒子径が５．０ｍｍ程度の予備発泡粒子を５０〜１００メッシュ程度の金網を内壁に装着した金型で成形することにより表面に予備発泡粒子形状模様が形成されない成形体を得ることが出来るとの記載があるが、該条件だけでは表面外観は充分には良好とはならない為、前記金型を使用すると共に通常の成形方法に比べて必要以上に成形時の予備発泡粒子の膨張（２次発泡）を促進させ、予備発泡粒子同士の密着度を高め、予備発泡粒子間に生じる隙間を極力減らす、即ち成形品表面に亀甲模様を形成させない様にすることが必要とされる。このため成形加熱時の水蒸気圧力やその加熱時間に代表される成形条件因子を通常の成形に比べて過剰に設定したり、予備発泡粒子に通常より高い内圧を付与する若しくは予備発泡粒子を過剰に圧縮した状態で金型内に充填するなどして、予備発泡粒子に過剰な発泡力を与える成形条件とすることが必要であった。特に複雑形状の成形体では、十分な表面性を確保することは難しく、安定性に欠ける傾向がある。これを避けるためにさらに成形条件を過剰に設定することが必要となるが、そうなれば必然的に冷却時間が延びるという弊害が生じ、成形サイクルが長くなるということが避けられず、生産性を悪化させるという問題があった。 In Patent Document 1, a pre-foamed particle shape pattern is not formed on the surface by molding pre-foamed particles having an average particle diameter of about 5.0 mm with a mold having a metal mesh of about 50 to 100 mesh mounted on the inner wall. Although there is a description that it can be obtained, the surface appearance does not become sufficiently good only under these conditions, so the pre-expanded particles at the time of molding more than necessary as compared with the normal molding method while using the mold It is necessary to promote the expansion (secondary foaming) of the particles, increase the adhesion between the pre-foamed particles, and reduce the gaps between the pre-foamed particles as much as possible, that is, to prevent the formation of a turtle shell pattern on the surface of the molded product. The For this reason, the water vapor pressure at the time of molding heating and the molding condition factors represented by the heating time are set excessively compared to normal molding, the pre-expanded particles are given an internal pressure higher than usual, or the pre-expanded particles are excessive. It was necessary to set the molding conditions to give excessive foaming force to the pre-foamed particles by filling the mold in a compressed state. In particular, it is difficult to secure a sufficient surface property in a complex-shaped molded body, and the stability tends to be lacking. In order to avoid this, it is necessary to set the molding conditions excessively. However, if this happens, there is a disadvantage that the cooling time is inevitably prolonged, and it is unavoidable that the molding cycle becomes long, and productivity is increased. There was a problem of making it worse.

特許文献２には、単に１００〜３００メッシュの金網を用いることが記載されているが、使用する予備発泡粒子の粒子径の点から問題解決を図ったものではなく、また、上記同様、成形サイクルが長くなり生産性が悪くなるという問題がある。特許文献３も特に使用する予備発泡粒子の粒子径から問題解決へのアプローチはなされておらず、また特殊な成形条件にて成形するとの記載があることから、成形サイクルは長くなるという問題がある。 Patent Document 2 describes that a wire mesh of 100 to 300 mesh is simply used, but the problem is not solved in terms of the particle diameter of the pre-expanded particles to be used. There is a problem that becomes longer and the productivity becomes worse. Patent Document 3 also has a problem that the molding cycle becomes long because there is no description of the problem solving from the particle size of the pre-expanded particles used in particular and there is a description that molding is performed under special molding conditions. .

これらの問題を解決する方法として、特許文献４には、成形体表面に素材の表面結晶状模様の単位径と同等またはそれよりも狭い（１／４以上）ピッチの凹凸条より構成された幾何学模様を施すことにより、亀甲模様を目立たなくさせる方法が記載されている。ところがここでは凹凸模様のピッチは限定されているものの、凹凸模様の深さについては言及されていない。そのため、十分な改善効果が得られるものではなかった。 As a method for solving these problems, Patent Document 4 discloses that a geometrical surface composed of concave and convex stripes having a pitch equal to or narrower (1/4 or more) than the unit diameter of the surface crystalline pattern of the material is formed on the surface of the molded body. It describes how to make the turtle shell pattern inconspicuous by applying a study pattern. However, although the pitch of the concavo-convex pattern is limited here, the depth of the concavo-convex pattern is not mentioned. Therefore, a sufficient improvement effect cannot be obtained.

また、表面平滑性を良好にする手法として、特許文献５にはある特定の表面粗さとなる様な凹凸模様を有する成形体が開示されており、凹凸模様の高低差を小さくする事により、肉眼では特異と知覚されない良好な表面形状となるとの記載がある。しかしながらこの方法では、確かに凹凸模様の高低差を小さくすることで、局部的なボイドや突起を目立たなくすることは可能であるが、これだけでは前記した亀甲模様が十分に解消しないという問題があった。
特開昭６０−８０４７号公報実開昭５７−１４９２５８号公報特開平６−１９８７５４号公報実開昭６３−１０８７２８号公報特開平４−２５４３９号公報 In addition, as a technique for improving the surface smoothness, Patent Document 5 discloses a molded article having a concavo-convex pattern that has a specific surface roughness, and by reducing the height difference of the concavo-convex pattern, There is a description that the surface shape is not perceived as peculiar. However, with this method, it is possible to make local voids and protrusions inconspicuous by reducing the height difference of the uneven pattern, but this alone has the problem that the above-described turtle shell pattern cannot be sufficiently resolved. It was.
Japanese Patent Laid-Open No. 60-8047 Japanese Utility Model Publication No. 57-149258 Japanese Unexamined Patent Publication No. 6-198754 Japanese Utility Model Publication No. 63-108728 Japanese Patent Laid-Open No. 4-25439

そこで本発明者らは、上記のような問題を鑑みて、予備発泡粒子の融着痕に起因する亀甲模様を十分に目立たなくさせ、表面平滑性の良好な熱可塑性樹脂型内発泡成形体の製造方法に関して鋭意検討した結果、使用する予備発泡粒子の粒子径と表面の凹凸模様の幅或いは深さといった寸法が特定の関係にあるとき、過剰な成形条件で亀甲模様を目立たなくすることなく、ほぼ従来と同様の成形条件で、所望の外観を有する型内発泡成形体が得られることを見出し、本発明を完成するに至った。 Therefore, in view of the above problems, the present inventors have made the turtle shell pattern caused by the fusion marks of the pre-foamed particles sufficiently inconspicuous, and the thermoplastic resin in-mold foam molded article having good surface smoothness. As a result of earnestly examining the manufacturing method, when the dimensions such as the particle diameter of the pre-expanded particles to be used and the width or depth of the uneven pattern on the surface are in a specific relationship, without making the turtle shell pattern inconspicuous under excessive molding conditions, The inventors have found that an in-mold foam molded article having a desired appearance can be obtained under molding conditions almost the same as conventional ones, and have completed the present invention.

すなわち本発明の第１は、成形金型の表面の少なくとも一部分に略規則的な凹凸模様を有する成形金型を用いた熱可塑性樹脂型内発泡成形方法において、金型表面凹凸模様の凹部幅ａおよび凹部深さｃと予備発泡粒子の粒子径Ｄが、０．１≦ａ／Ｄ≦１．０、かつ、０．１≦ｃ／Ｄ≦１．０を満たすことを特徴とする熱可塑性樹脂型内発泡成形方法に関する。 That is, the first aspect of the present invention is a method for foam molding in a thermoplastic resin mold using a molding die having a substantially regular concavo-convex pattern on at least a part of the surface of the molding die, and the concave width a of the concavo-convex pattern on the mold surface. And the depth c of the recess and the particle diameter D of the pre-expanded particles satisfy 0.1 ≦ a / D ≦ 1.0 and 0.1 ≦ c / D ≦ 1.0. The present invention relates to an in-mold foam molding method.

好ましい実施態様としては、
（１）金型表面の凹凸模様において、凹部幅ａ、凸部幅ｂ、凹部深さｃが、
（ｂ＋ｃ）／ａ≧０．５、かつ、ｃ≧ｂを満たす成形金型を用いることを特徴とする、
（２）粒子径Ｄが０．１ｍｍ以上２．０ｍｍ以下の熱可塑性樹脂予備発泡粒子を表面凹凸模様の凹部深さｃが０．４ｍｍ以下である成形金型を用いることを特徴とする、
（３）熱可塑性樹脂がポリプロピレン系樹脂またはポリエチレン系樹脂である、
（４）前記凹凸模様が成形金型の表面に形成されてなる成形金型を用いた、
（５）成形金型表面に前記凹凸模様を有しかつ蒸気孔を有さない金型Ａと、成形金型表面に前記凹凸模様を有さずかつ蒸気孔を有する金型Ｂとからなる金型を用いた、
（６）成形金型表面に前記凹凸模様を有しかつ蒸気孔を有さない金型Ａと成形金型表面に前記凹凸模様を有さずかつ蒸気孔を有する金型Ｂとを型締めして成形型を構成した後、熱可塑性樹脂粒子を該成形型内に充填し、金型Ｂの蒸気孔から水蒸気を供給し、該発泡粒子が互いに融着する温度よりも低い温度で該予備発泡粒子を予備加熱し、該予備発泡粒子を水蒸気で蒸らし、ついでドレインを除去した後に該予備発泡粒子が互いに融着する温度以上の温度で該予備発泡粒子を本加熱することを特徴とする、
上記記載の熱可塑性樹脂型内発泡成形方法に関する。 As a preferred embodiment,
(1) In the uneven pattern on the mold surface, the recess width a, the protrusion width b, and the recess depth c are
(B + c) /a≧0.5 and a molding die satisfying c ≧ b is used,
(2) A thermoplastic resin pre-expanded particle having a particle diameter D of 0.1 mm or more and 2.0 mm or less is used, and a molding die having a concave-convex depth c of 0.4 mm or less is used.
(3) The thermoplastic resin is a polypropylene resin or a polyethylene resin.
(4) Using a molding die in which the uneven pattern is formed on the surface of the molding die,
(5) A mold consisting of a mold A having the concavo-convex pattern on the surface of the molding die and having no steam holes, and a mold B having no concavo-convex pattern on the surface of the molding mold and having steam holes. Using the mold,
(6) A mold A having the uneven pattern on the surface of the molding die and having no steam holes and a mold B not having the uneven pattern on the surface of the molding mold and having the steam holes are clamped. After forming the mold, the thermoplastic resin particles are filled into the mold, water vapor is supplied from the vapor holes of the mold B, and the preliminary foaming is performed at a temperature lower than the temperature at which the foamed particles are fused to each other. Pre-heating the particles, steaming the pre-expanded particles with water vapor, and then removing the drain, followed by main heating the pre-expanded particles at a temperature equal to or higher than the temperature at which the pre-expanded particles fuse together,
The present invention relates to the above-mentioned thermoplastic resin in-mold foam molding method.

本発明の第２は、上記記載の製造方法により製造される熱可塑性樹脂型内発泡成形体に関する。 2nd of this invention is related with the thermoplastic resin in-mold expansion-molding body manufactured by the manufacturing method of the said description.

本発明によれば、所定の予備発泡粒子の粒子径と金型表面の凹凸模様のサイズを採用することにより、従来の方法に比べて、予備発泡粒子の型内発泡成形における欠点であった亀甲模様を、いとも簡単に且つ安定的に解消することが出来、且つ、表面平滑性を良好に出来得るものである。また、この様にして得られた成形体は、優れた外観を有していることから、建材、包装材、自動車部材等における外観を重視する部分にも好適に用いることが可能である。 According to the present invention, by adopting a predetermined particle diameter of the pre-expanded particles and the size of the concavo-convex pattern on the mold surface, compared with the conventional method, the tortoise shell which was a disadvantage in the in-mold expansion molding of the pre-expanded particles The pattern can be eliminated easily and stably, and the surface smoothness can be improved. In addition, since the molded body obtained in this way has an excellent appearance, it can be suitably used for a portion that emphasizes the appearance of building materials, packaging materials, automobile members, and the like.

本発明の熱可塑性樹脂型内発泡成形体の製造方法の一実施例を図面に基づいて説明する。 One example of a method for producing a thermoplastic resin in-mold foam molded product of the present invention will be described with reference to the drawings.

図１は本発明の製造法に用いられる成形型の一実施態様を示す概略説明図である。図１において、金型Ａ１が固定されている金型Ａ側フレーム５はたとえば成形機のシリンダー（図示無し）などと連結され、金型Ａ側フレーム５とともに金型Ａ１を移動させることによって、型締めおよび型開きを行うことができ、型締め状態で金型Ａ１と金型Ｂ２の間で成形空間７が形成される。金型Ａ１および金型Ｂ２にはそれぞれ複数の蒸気孔８が設けられている。 FIG. 1 is a schematic explanatory view showing an embodiment of a mold used in the production method of the present invention. In FIG. 1, a mold A side frame 5 to which a mold A1 is fixed is connected to, for example, a cylinder (not shown) of a molding machine, and the mold A1 is moved together with the mold A side frame 5 to move the mold A1. Clamping and mold opening can be performed, and a molding space 7 is formed between the mold A1 and the mold B2 in the mold-clamped state. A plurality of vapor holes 8 are provided in each of the mold A1 and the mold B2.

得られる成形体の優れた表面性が要求される面に対応する金型表面に凹凸模様が設けられる。本発明においては、表面の少なくとも一部に略規則的な凹凸模様を有するので、所望とする型内発泡成形体の外観に応じて、金型表面全体に凹凸模様を施しても良いし、一部に施してもよい。また異なるパターンの凹凸模様を複数使用してもよい。たとえば、板状成形体で一方の表面に表面性が要求される場合には、図１の様に金型Ａ１表面に凹凸模様を形成すれば良い。 An uneven pattern is provided on the mold surface corresponding to the surface that requires excellent surface properties of the obtained molded body. In the present invention, since at least a part of the surface has a substantially regular concavo-convex pattern, the entire mold surface may be provided with a concavo-convex pattern according to the desired appearance of the in-mold foam molded article. It may be applied to the part. A plurality of uneven patterns having different patterns may be used. For example, in the case where a surface property is required on one surface of a plate-like molded body, an uneven pattern may be formed on the surface of the mold A1 as shown in FIG.

凹凸模様の凹部、凸部の形状に特に限定はなく、凹部または凸部の少なくとも一方が、三角形、四角形、六角形等の多角形、円、楕円等の円形、等の独立した形状を有するものが例示できる。本発明に言う金型表面模様凹部幅ａ、金型表面模様凸部幅ｂ、金型表面模様凹部深さｃは、凹部と凹部若しくは凸部と凸部の互いに最も近接する独立した形状の中心同士を通る線上の断面における、凹部幅ａ、凸部幅ｂ、凹部深さｃを言う。前記最も近接する独立した形状の中心同士を通る線上とは、例えば図９、１０中Ａ−Ａ線の様に例示できる。前記断面形状としては図５、図６、図７、図８のように例示できる。図５は単純な凹凸模様であり、図６は角に丸みを帯びた凹凸模様である。図７はＶ字の凹部形状を有す凹凸模様であり、図８は金網を金型表面に設置する場合の断面凹凸模様である。金型表面凹部幅ａ、金型表面凸部幅ｂ、金型表面模様凹部深さｃはそれぞれ、図に示すように定義される。図６のような曲線で凹凸模様が構成されている場合、変曲点を基準に凹部幅ａと凸部幅ｂを規定する。図７の様な場合は、凹凸模様を構成する一辺の中点を基準に凹部幅ａと凸部幅ｂを規定する。図８の様に金網等を使用して凹凸模様を付与する場合には、金網を構成する針金の太さが凸部幅ｂ、針金と針金の間の寸法（目開き寸法）が凹部幅ａ、金網の厚みが凹部深さｃに相当する。 There is no particular limitation on the shape of the concave and convex portions of the concavo-convex pattern, and at least one of the concave or convex portions has an independent shape such as a polygon such as a triangle, a quadrangle, or a hexagon, or a circle such as a circle or an ellipse. Can be illustrated. The mold surface pattern concave portion width a, the mold surface pattern convex portion width b, and the mold surface pattern concave portion depth c referred to in the present invention are the centers of independent shapes of the concave portion and the concave portion or the convex portion and the convex portion that are closest to each other. The concave part width a, the convex part width b, and the concave part depth c in the cross section on the line which passes mutually are said. Examples of the line passing through the centers of the most adjacent independent shapes can be illustrated as AA lines in FIGS. Examples of the cross-sectional shape are as shown in FIGS. 5, 6, 7, and 8. FIG. 5 shows a simple concavo-convex pattern, and FIG. 6 shows a concavo-convex pattern with rounded corners. FIG. 7 shows a concavo-convex pattern having a V-shaped concave shape, and FIG. 8 shows a cross-sectional concavo-convex pattern when a metal net is installed on the mold surface. The mold surface recess width a, the mold surface protrusion width b, and the mold surface pattern recess depth c are respectively defined as shown in the figure. When the concavo-convex pattern is configured with a curve as shown in FIG. 6, the concave portion width a and the convex portion width b are defined based on the inflection point. In the case as shown in FIG. 7, the concave portion width a and the convex portion width b are defined based on the midpoint of one side constituting the concavo-convex pattern. When a concavo-convex pattern is imparted using a wire mesh or the like as shown in FIG. 8, the thickness of the wire constituting the wire mesh is the protrusion width b, and the dimension between the wire and the wire (opening dimension) is the recess width a. The thickness of the wire mesh corresponds to the recess depth c.

本発明の略規則的な凹凸模様とは、凹部が前記独立した形状を有する場合は凹部と凹部の距離（金型表面模様凸部幅ｂ）が略一定であることを言い、凸部が前記独立した形状を有する場合は凸部と凸部の距離（金型表面模様凹部幅ａ）が略一定であることを言う。 The substantially regular concavo-convex pattern of the present invention means that when the concave portion has the independent shape, the distance between the concave portion and the concave portion (mold surface pattern convex portion width b) is substantially constant. When it has an independent shape, it means that the distance between the convex part and the convex part (mold surface pattern concave part width a) is substantially constant.

金型の表面に凹凸模様を形成する方法としては、得られる成形体表面に所望の凹凸模様を転写できる方法であればよく、大別して、金型表面に他の材質を付けた金型を使用する方法と金型自身を掘削する等の加工を施した金型を使用する方法が挙げられる。前者の方法に使用する金型としては、図２のように金属メッシュやパンチングメタルなどの多孔質材を金型表面に貼り付けたものであっても良いし、後者の方法に使用する金型としては、図３のように凹凸模様を金型自身の表面に付与しても良い。なお後者の場合は、蒸気孔は図３のように金型で凸の部分（成形体においては凹の部分）に設けることで、成形品表面で蒸気孔痕が認識され難くなる効果が得られる。 As a method for forming a concavo-convex pattern on the surface of the mold, any method can be used as long as the desired concavo-convex pattern can be transferred to the surface of the resulting molded body. And a method of using a die that has been processed such as excavating the die itself. The mold used in the former method may be a mold in which a porous material such as a metal mesh or punching metal is attached to the mold surface as shown in FIG. 2, or a mold used in the latter method. As shown in FIG. 3, a concavo-convex pattern may be provided on the surface of the mold itself. In the latter case, the steam hole is provided in a convex part (a concave part in the molded body) of the mold as shown in FIG. 3, so that the effect of making it difficult to recognize the steam hole trace on the surface of the molded product is obtained. .

本発明においては、前記金型表面の凹凸模様は、金型表面模様凹部幅ａ、金型表面模様凹部深さｃが使用する予備発泡粒子径Ｄとの間に、０．１≦ａ／Ｄ≦１．０、０．１≦ｃ／Ｄ≦１．０の関係を満たすことが必要である。このような模様を設けることにより、成形体表面の亀甲模様が観察され難くなる理由は定かではないが、凹凸模様により成形体表面が乱反射し、亀甲模様を目立たなくする効果がある、もしくは、粒子の結合部分が金型の凸部に押し込まれ、粒子模様や粒子間の僅かな隙間が成形品で凹部に隠され、目立たなくなる効果があるのではないかと考えられる。本発明の表面に凹凸模様を有する金型を使用することで、成形時に過剰な成形条件にて成形を行わなくとも良好な表面性を有する型内発泡成形体が得られるものと考えられる。 In the present invention, the concavo-convex pattern on the mold surface is 0.1 ≦ a / D between the mold surface pattern recess width a and the mold surface pattern recess depth c used. It is necessary to satisfy the relationship of ≦ 1.0 and 0.1 ≦ c / D ≦ 1.0. By providing such a pattern, the reason why it is difficult to observe the turtle shell pattern on the surface of the molded body is not clear, but the surface of the molded body is irregularly reflected by the uneven pattern, and the effect of making the turtle shell pattern inconspicuous, or particles It is thought that there is an effect that the joint portion is pushed into the convex portion of the mold, and a slight gap between the particle pattern and the particle is hidden in the concave portion by the molded product and becomes inconspicuous. By using a mold having a concavo-convex pattern on the surface of the present invention, it is considered that an in-mold foam molded article having good surface properties can be obtained without molding under excessive molding conditions during molding.

ｃ／Ｄが０．１未満の場合には、成形体表面に亀甲模様が観察され易くなる。また、ｃ／Ｄは大きいほど亀甲模様は観察され難くなる傾向にあるが、ある程度の値を越えると実質的に大きな効果は期待できず、逆に予備発泡粒子が型内発泡成形時の膨張により金型凹部底面に到達することが困難となり金型転写性が悪くなり、表面を悪化させる傾向にあることから、上限を１．０とすることが適当であり、好ましくは、０．２≦ｃ／Ｄ≦１．０とすることにより、より容易に本発明の効果を発揮し得るものである。 When c / D is less than 0.1, a turtle shell pattern is easily observed on the surface of the molded body. In addition, the larger the c / D, the more difficult it is to observe the turtle shell pattern. However, if the value exceeds a certain value, a substantial effect cannot be expected. Conversely, the pre-expanded particles are expanded by expansion during in-mold foam molding. Since it is difficult to reach the bottom surface of the mold recess and the mold transferability tends to deteriorate and the surface tends to deteriorate, it is appropriate to set the upper limit to 1.0, preferably 0.2 ≦ c. By setting /D≦1.0, the effects of the present invention can be more easily exhibited.

ａ／Ｄが１．０を超える場合は、成形品の最外表面に粒間が配置され易く、亀甲模様が確認され易い。０．１未満の場合は、加熱時に金型凹部に予備発泡粒子が入り込むことが困難となり、金型の凹凸模様を正確に転写することが困難となる。好ましくは、０．２≦ａ／Ｄ≦０．８とすることで、本発明の効果をより発揮することが出来る。 When a / D exceeds 1.0, the intergranularity is easily arranged on the outermost surface of the molded product, and the turtle shell pattern is easily confirmed. When it is less than 0.1, it becomes difficult for the pre-expanded particles to enter the concave portion of the mold during heating, and it becomes difficult to accurately transfer the concave / convex pattern of the mold. Preferably, by making 0.2 ≦ a / D ≦ 0.8, the effect of the present invention can be further exhibited.

また本発明では、金型表面模様凹部幅ａ、金型表面模様凸部幅ｂ、金型表面模様凹部深さｃが
（ｂ＋ｃ）／ａ≧０．５、ｃ≧ｂ
を満たす金型を使用することにより、より容易に成形体表面の亀甲模様を目立たなくすることが出来る。この様な効果が得られる詳細な理由は定かではないが、（ｂ＋ｃ）／ａが大きいと成形体で窪み（陰）になる部分の割合が大きくなり、亀甲模様をより成形品凹部に隠す効果が発揮されると考えられ、その値は０．５以上であることが好ましく、更には０．７以上であることが好ましい。 In the present invention, the mold surface pattern recess width a, the mold surface pattern protrusion width b, and the mold surface pattern recess depth c are (b + c) /a≧0.5, c ≧ b.
By using a mold that satisfies the above, the turtle shell pattern on the surface of the molded body can be made inconspicuous more easily. The detailed reason why such an effect is obtained is not clear, but if (b + c) / a is large, the ratio of the depression (shade) in the molded body increases, and the effect of hiding the turtle shell pattern in the recessed part of the molded product more The value is preferably 0.5 or more, and more preferably 0.7 or more.

加えてｃがｂより小さいと、成形品で凹部底面を影にする効果が薄れ、亀甲模様が観察され易くなるということから、ｃ≧ｂであることが好ましい。その他のｃとｂの関係は特に限定するものではないが、金型の該部強度が不足するということから、上限はｃはｂの１０倍以下に設定することが更に好ましい。 In addition, when c is smaller than b, the effect of shadowing the bottom surface of the recess in the molded product is weakened, and the turtle shell pattern is easily observed. Therefore, c ≧ b is preferable. The other relationship between c and b is not particularly limited, but the upper limit of c is more preferably set to 10 times or less of b because the strength of the part of the mold is insufficient.

前記金型Ａ１と金型Ｂ２とを型締めし、フィーダー９を介して前記熱可塑性予備発泡粒子を成形型の成形室７内に充填する。 The mold A1 and the mold B2 are clamped, and the thermoplastic pre-expanded particles are filled into the molding chamber 7 of the mold through a feeder 9.

前記熱可塑性樹脂予備発泡粒子に用いられる熱可塑性樹脂としては、ポリスチレン、ポリプロピレン、ポリエチレン、エチレン−プロピレンコポリマー、プロピレン−塩化ビニルコポリマー、プロピレン−ブテンコポリマー、プロピレン−無水マレイン酸コポリマー、エチレン−プロピレン−ブテンターポリマーなどがあげられ、これらは単独でまたは２種以上を混合して、用いることができる。これらの熱可塑性樹脂の中では、通常、成形体表面に粒子間の隙間が生じ易く、本発明の効果が発揮され易いことから、ポリエチレン系樹脂およびポリプロピレン系樹脂であることが好ましく、更にはポリプロピレン系樹脂に好適である。 The thermoplastic resin used for the thermoplastic resin pre-expanded particles includes polystyrene, polypropylene, polyethylene, ethylene-propylene copolymer, propylene-vinyl chloride copolymer, propylene-butene copolymer, propylene-maleic anhydride copolymer, ethylene-propylene-butene. A terpolymer etc. are mention | raise | lifted and these can be used individually or in mixture of 2 or more types. Among these thermoplastic resins, usually, a gap between particles is likely to occur on the surface of the molded body, and the effects of the present invention are easily exhibited. It is suitable for a resin.

前記熱可塑性樹脂予備発泡粒子を製造する方法としては、公知の方法でよく、たとえば耐圧容器中で、熱可塑性樹脂粒子に揮発性発泡剤を含有させ、攪拌しながら水中に分散させ、加圧下で所定の発泡温度まで加熱した後、該水分散物を低圧域に放出する方法などが挙げられるが、本発明はかかる方法によって限定されるものではない。 As a method for producing the thermoplastic resin pre-foamed particles, a known method may be used. For example, in a pressure vessel, the thermoplastic resin particles contain a volatile foaming agent, dispersed in water with stirring, and under pressure. Examples thereof include a method of releasing the aqueous dispersion to a low pressure region after heating to a predetermined foaming temperature, but the present invention is not limited to such a method.

本発明に用いられる予備発泡粒子の粒子径Ｄは、特に限定されず、通常使用される０．５〜４．０ｍｍ程度のものであってもよく、さらに小さい粒子径であっても良い。ただし、あまりに小さい粒子径では、蒸気による加熱を行う際に、蒸気の通路となる粒子間が小さくなり効率よく予備発泡粒子を加熱することが困難となるため、下限は０．１ｍｍとすることが好ましい。 The particle diameter D of the pre-expanded particles used in the present invention is not particularly limited, and may be about 0.5 to 4.0 mm ordinarily used, or a smaller particle diameter. However, if the particle size is too small, the space between the particles that become the passage of the vapor becomes small and it becomes difficult to efficiently heat the pre-expanded particles, so the lower limit may be 0.1 mm. preferable.

さらに本発明における好ましい態様としては、粒子径Ｄが０．１ｍｍ以上２．０ｍｍ以下の熱可塑性樹脂予備発泡粒子を表面凹凸模様凹部深さｃが０．４ｍｍ以下である金型を用いることである。このような条件にすることで亀甲模様を有さずかつ、微細な凹凸模様からなるゴツゴツ感の少ない滑らかな表面を有する、即ち表面平滑性の良好な成形体が比較的容易に得られるものである。ここで粒子径Ｄとして２．０ｍｍ以下が好ましい理由は、以下の通りである。 Furthermore, as a preferable aspect in the present invention, a thermoplastic resin pre-expanded particle having a particle diameter D of 0.1 mm or more and 2.0 mm or less is used with a mold having a surface unevenness pattern recess depth c of 0.4 mm or less. . By using such a condition, a molded article having a smooth surface with no ruggedness and having a fine concavo-convex pattern, that is, having a smooth surface, that is, having a good surface smoothness can be obtained relatively easily. is there. The reason why the particle diameter D is preferably 2.0 mm or less is as follows.

成形体表面がゴツゴツ感の少ない滑らかな印象を与えるためには、前記ｃを０．４ｍｍ以下とすることが好ましい。これに対して、ｃ／Ｄは大きい程表面の亀甲模様が観察され難くなる効果が大きいため、粒子径Ｄは小さい方が好ましく、その値は２．０ｍｍ以下とすることが好ましい。 In order to give a smooth impression with less ruggedness on the surface of the molded body, it is preferable that c is 0.4 mm or less. On the other hand, the larger the c / D, the greater the effect that the turtle shell pattern on the surface becomes difficult to be observed. Therefore, the smaller the particle diameter D, the smaller the value is preferably 2.0 mm or less.

なお本発明における予備発泡粒子の粒子径Ｄは以下の方法により定義されるものとする。 The particle diameter D of the pre-expanded particles in the present invention is defined by the following method.

たとえば５００ｍｌカップ一杯程度の予備発泡粒子（粒子の総重量Ｗ）を準備し、ＪＩＳＺ８８０１によって規定された目開きをもつ標準ふるいを使用してふるい分け試験を実施する。 For example, pre-expanded particles (total weight W of particles) of about 500 ml cup are prepared, and a screening test is performed using a standard sieve having an opening defined by JIS Z 8801.

その結果、各ふるいの目開き寸法Ｍ_iと各ふるい上に残った予備発泡粒子の重量Ｗ_iとから下記式により算出する。 As a result, it is calculated by the following formula from the opening size M _i of each sieve and the weight W _i of the pre-expanded particles remaining on each sieve.

Ｄ＝（Ｗ₁×Ｍ₁＋Ｗ₂×Ｍ₂＋・・・・・Ｗ_i×Ｍ_i）／Ｗ
前記熱可塑性樹脂予備発泡粒子をフィーダー９を通じて成形室７内に充填するに際しては、あらかじめ予備発泡粒子を加圧ガスを用いて加圧し、該加圧ガスが該予備発泡粒子中に十分に浸透され、内圧が付与された状態で成形室７内に充填してもよく、該予備発泡粒子を加圧ガスを用いて圧縮した状態で成形室７内に充填してもよく、また該予備発泡粒子に内圧を付与したり、圧縮することなく、そのままの状態で成形室７内に充填してもよい。本発明はかかる充填方法によって限定されるものではないが、より予備発泡粒子に膨張力を与え、より粒子間の隙間を埋める効果が期待できるという観点から、予備発泡粒子にあらかじめ内圧を付与するもしくは予備発泡粒子を圧縮した状態で充填することが好ましい。 D = (W ₁ × M ₁ + W ₂ × M ₂ +... W _i × M _i ) / W
When filling the thermoplastic resin pre-expanded particles into the molding chamber 7 through the feeder 9, the pre-expanded particles are previously pressurized using a pressurized gas, and the pressurized gas is sufficiently permeated into the pre-expanded particles. In addition, the molding chamber 7 may be filled with an internal pressure applied, or the pre-expanded particles may be filled into the molding chamber 7 in a compressed state using a pressurized gas. The inside of the molding chamber 7 may be filled as it is without applying an internal pressure or compressing it. The present invention is not limited by such a filling method, but from the viewpoint that it is possible to expect the effect of more expanding the pre-expanded particles and filling the gaps between the particles, the pre-expanded particles are preliminarily applied with internal pressure or It is preferable to fill the pre-expanded particles in a compressed state.

前記熱可塑性樹脂予備発泡粒子を成形室７内に充填した後、成形室７内に水蒸気を導入する。水蒸気は、金型Ａ側蒸気ライン１１および金型Ｂ側蒸気ライン１０からそれぞれ金型Ａ１およびＢ２背面の蒸気室３および４に導入される。蒸気室３および４に導入された蒸気は、さらに金型Ａ１およびＢ２の蒸気孔８を通って、成形室７内に導入される。 After filling the thermoplastic resin pre-expanded particles into the molding chamber 7, water vapor is introduced into the molding chamber 7. Water vapor is introduced from the mold A side steam line 11 and the mold B side steam line 10 into the steam chambers 3 and 4 on the back of the molds A1 and B2, respectively. The steam introduced into the steam chambers 3 and 4 is further introduced into the molding chamber 7 through the steam holes 8 of the molds A1 and B2.

まず水蒸気は予備発泡粒子が融着する温度よりも低い温度となるように金型Ａ１およびＢ２のそれぞれの蒸気孔８から成形室７内へ供給され、予備発泡粒子を予備的に加熱しておく（一方加熱、逆一方加熱）。 First, water vapor is supplied into the molding chamber 7 from the respective vapor holes 8 of the molds A1 and B2 so that the temperature becomes lower than the temperature at which the pre-expanded particles are fused, and the pre-expanded particles are preliminarily heated. (One side heating, reverse one side heating).

次いで、予備発泡粒子が互いに融着する温度以上、好ましくは融着温度よりも５℃高い温度以上の温度で該予備発泡粒子を本加熱する。この際の水蒸気の圧力は、従来の型内発泡成形と何ら変わりなく、例えば、予備発泡粒子が互いに融着する温度以上でかつ予備発泡粒子が融着する温度よりも３０℃高い温度以下とする事が好ましい。 Next, the pre-expanded particles are subjected to main heating at a temperature equal to or higher than a temperature at which the pre-expanded particles are fused to each other, preferably at a temperature higher by 5 ° C. than the fusing temperature. The pressure of the water vapor at this time is not different from the conventional in-mold foam molding, for example, not less than the temperature at which the pre-foamed particles are fused to each other and 30 ° C. or higher than the temperature at which the pre-foamed particles are fused. Things are preferable.

なお前記融着する温度とは、奥行きが５０ｍｍ程度の金型内に予備発泡粒子を充填し、所定温度（所定圧力）の水蒸気を１０〜２０秒間該金型内に導入した時に、予備発泡粒子同士が融着し、発泡成型体の形状を保持することが出来る状態となるときの最低温度をいう。 The fusing temperature refers to pre-expanded particles when pre-expanded particles are filled in a mold having a depth of about 50 mm and water vapor at a predetermined temperature (predetermined pressure) is introduced into the mold for 10 to 20 seconds. It refers to the minimum temperature at which the parts can be fused together to maintain the shape of the foamed molded product.

前記予備発泡粒子を本加熱後、成形体は冷却され、金型Ａ１および金型Ｂ２を型開きすることにより、型内発泡成形体が得られる。なおかかる冷却の際の温度は、予備発泡粒子の種類、発泡成形体の発泡倍率によって異なるので一概には決定することが出来ないが、通常成形型から取り出した発泡成形体に後ぶくれが生じない温度が選ばれる。 After the pre-expanded particles are heated, the molded body is cooled, and the mold A1 and the mold B2 are opened to obtain an in-mold foam molded body. The temperature at the time of cooling varies depending on the type of pre-expanded particles and the expansion ratio of the foamed molded product, so it cannot be determined unconditionally. No temperature is chosen.

前記発泡体の発泡倍率は、通常利用される範囲で適用可能であるが、あまりにも大きい場合には、得られる成形体の収縮が大きくなる傾向にあるため、３倍以上６０倍以下、特には３倍以上５０倍以下程度であることが好ましい。 The foaming ratio of the foam can be applied within the range normally used, but if it is too large, the shrinkage of the resulting molded product tends to increase, so it is 3 to 60 times, especially It is preferably about 3 to 50 times.

更に本発明における凹凸模様を表面に有する金型において、図４のように凹凸模様を有する部位に蒸気孔を付与しないことにより、蒸気孔痕の無い表面性の良好な成形体を得ることが可能である。 Furthermore, in the mold having a concavo-convex pattern on the surface according to the present invention, it is possible to obtain a molded article having a good surface property without a vapor hole trace by not providing a vapor hole in a portion having a concavo-convex pattern as shown in FIG. It is.

この場合、凹凸模様を有する部位に蒸気孔を有さないため、該凹凸模様を有する部位の加熱が不十分となり易く成形体表面に亀甲模様が観察され易くなる傾向にあるが、次のような方法で成形することにより、より容易に表面性向上効果が期待できる。 In this case, since there is no vapor hole in the portion having the concavo-convex pattern, heating of the portion having the concavo-convex pattern tends to be insufficient, and the turtle shell pattern tends to be observed on the surface of the molded body. By molding by this method, the effect of improving surface properties can be expected more easily.

具体的には前記凹凸模様を有しかつ蒸気孔を有さない金型Ａ１と前記凹凸模様を有さずかつ蒸気孔を有する金型Ｂ２とを型締めして成形型を構成した後、熱可塑性樹脂粒子を該成形型内に充填し、金型Ｂ２の蒸気孔から水蒸気を供給し、該発泡粒子が互いに融着する温度よりも低い温度で該予備発泡粒子を予備加熱し、該予備発泡粒子を水蒸気で蒸らし、ついでドレインを除去した後に該予備発泡粒子が互いに融着する温度以上の温度で該予備発泡粒子を本加熱することにより得られる。 Specifically, after forming the mold by clamping the mold A1 having the concavo-convex pattern and not having the vapor holes and the mold B2 having no concavo-convex pattern and having the vapor holes, Filling the mold with plastic resin particles, supplying water vapor from the vapor holes of the mold B2, preheating the pre-expanded particles at a temperature lower than the temperature at which the expanded particles are fused together, and pre-expanding It can be obtained by steaming the particles with water vapor and then heating the pre-expanded particles at a temperature equal to or higher than the temperature at which the pre-expanded particles are fused together after removing the drain.

前記の如く水蒸気で蒸らすとは、前記予備加熱を実施した後に、予備加熱の状態を保持する、もしくは水蒸気の供給を停止した状態を保持するなどして、水蒸気の潜熱を有効に利用して予備発泡粒子を均一に加熱し得る状態をつくることをいう。なお、予備発泡粒子をこの様に蒸らす場合には、かかる蒸らしに要する時間は、成形型内における予備発泡粒子層の厚さ、予備発泡粒子の大きさ、形状や発泡倍率などによって異なるため一概には決定することは出来ないが、通常予備発泡粒子層の厚さが例えば５０ｍｍ程度のもので約３秒以上、好ましくは５秒以上、よりこのましくは１０秒以上とすることが望ましい。 Steaming with water vapor as described above means that after the preheating is performed, the preheating state is maintained, or the supply state of water vapor is stopped, for example, by effectively using the latent heat of the water vapor. This refers to creating a state where the expanded particles can be heated uniformly. When the pre-expanded particles are steamed in this way, the time required for such steaming varies depending on the thickness of the pre-expanded particle layer in the mold, the size of the pre-expanded particles, the shape, the expansion ratio, etc. However, it is generally desirable that the thickness of the pre-expanded particle layer is about 50 mm, for example, about 3 seconds or longer, preferably 5 seconds or longer, more preferably 10 seconds or longer.

前記蒸らしを行った後には、予備発泡粒子間にドレイン（水分）が存在し、その状態で本加熱を行えば、予備発泡粒子同士の融着不良が生じるため、蒸らしで生じたドレインを除去することが好ましい。かかるドレインを除去する方法としては、特に限定される物ではないが、たとえば金型Ｂ２に設けられた蒸気孔８を利用して成形室７内を真空吸引する等の方法により実施される。 After the steaming, there is a drain (moisture) between the pre-foamed particles, and if the main heating is performed in this state, the poor fusion between the pre-foamed particles occurs, so the drain produced by the steam is removed. It is preferable. The method for removing the drain is not particularly limited. For example, the drain is removed by a method of vacuuming the interior of the molding chamber 7 using the vapor hole 8 provided in the mold B2.

また前記本加熱時の水蒸気は、蒸気ライン１０から蒸気室４を介して金型Ｂ２の蒸気孔８から成形室７へ供給されるだけでも良いし、それと同時に蒸気ライン１１からも蒸気室３へ導入されても良いが、金型Ａ１が加熱されることでより効率的に加熱が行える点から後者の方が好ましい。 The steam during the main heating may be supplied from the steam line 10 through the steam chamber 4 to the molding chamber 7 through the steam hole 8 of the mold B2, and at the same time from the steam line 11 to the steam chamber 3. Although it may be introduced, the latter is preferable because the mold A1 can be heated more efficiently by heating.

以下、実施例を挙げて本発明をさらに詳細に説明するが、これらは本発明をなんら限定するものではない。
（実施例１）
多孔質材として表１に示す凹凸模様を有するステンレス製平織金網（４０メッシュ）を使用した金型（成形室の寸法：縦４００ｍｍ、横３００ｍｍ、奥行き２０ｍｍ）を用意した。 EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, these do not limit this invention at all.
(Example 1)
A mold (molding chamber dimensions: 400 mm length, 300 mm width, 20 mm depth) using a stainless steel plain woven wire mesh (40 mesh) having a concavo-convex pattern shown in Table 1 as a porous material was prepared.

熱可塑性樹脂予備発泡粒子として、エチレン−プロピレンランダム共重合体（エチレン含有量：２．８モル％、メルトフローレート：７ｇ／１０分、融点：１４５℃）を基材樹脂とするポリプロピレン系予備発泡粒子（発泡倍率３．４倍、粒子径１．７６ｍｍ）を予め耐圧容器に入れて空気圧で内圧０．０５ＭＰａが付与されたものを用い、これをフィーダー９を介して、前記金型内に充填した。 Polypropylene-based pre-foaming using an ethylene-propylene random copolymer (ethylene content: 2.8 mol%, melt flow rate: 7 g / 10 min, melting point: 145 ° C.) as a base resin as thermoplastic resin pre-foaming particles Particles (foaming ratio: 3.4 times, particle diameter: 1.76 mm) are put in a pressure-resistant container in advance and given an internal pressure of 0.05 MPa by air pressure, and this is filled into the mold through the feeder 9 did.

次に金型Ａ１および金型Ｂ２の蒸気孔からそれぞれ順次水蒸気を成形室７に導入し、一方加熱、逆一方加熱を実施した後、本加熱として水蒸気（蒸気圧０．３５ＭＰａ、温度１４６〜１５０℃）を成形室７に1０秒間導入し、予備発泡粒子同士を膨張・融着させた後、３０℃の水を用いて１２０秒間冷却し、ついで金型Ａ１、金型Ｂ２とを型開きして、多孔質材に接した面に、多孔質材面に基づく模様が転写された成形体を得た。 Next, water vapor is sequentially introduced into the molding chamber 7 from the vapor holes of the mold A1 and the mold B2, respectively, and after one heating and reverse one heating are performed, water vapor (vapor pressure 0.35 MPa, temperature 146 to 150 is used as the main heating. ℃) is introduced into the molding chamber 7 for 10 seconds, the pre-expanded particles are expanded and fused together, then cooled at 30 ° C for 120 seconds, and then the mold A1 and the mold B2 are opened. Thus, a molded body in which the pattern based on the porous material surface was transferred to the surface in contact with the porous material was obtained.

得られた成形体外観を以下の評価基準により評価した。その結果を表１に示す。
−成形品外観評価基準−
（１）亀甲模様：
○・・・亀甲模様が目立たない
△・・・よく見ると僅かに亀甲模様が観察されるが、ほとんど問題とならないレベル
×・・・亀甲模様が容易に判別でき、ボイドも観察される
（２）表面平滑性：
○・・・きめ細かく滑らかな表面
△・・・目が粗く、ゴツゴツ感を有する表面
（実施例２）
表１に示す凹凸模様を有するステンレス金網（２０メッシュ）を使用し、発泡倍率３．６倍、粒子径２．４３ｍｍのポリプロピレン予備発泡粒子を用いること以外は、実施例１と同様にして成形体を得た。
（実施例３）
発泡倍率１５．６倍、粒子径３．２５ｍｍで内圧０．１０ＭＰａが付与されたポリプロピレン予備発泡粒子を表１に示す凹凸模様を有するステンレス金網（１８メッシュ）を使用した金型内に充填し、本加熱として水蒸気（蒸気圧０．３０ＭＰａ、温度１４２〜１４６℃）を成形室７に８秒間導入した以外は、実施例１と同様にして成形体を得た。
（実施例４）
金型自身の表面に、表１に示す凹凸模様を有する金型（成形室の寸法：縦４００ｍｍ、横３００ｍｍ、奥行き２０ｍｍ）を使用した以外は、実施例１と同様にして成形体を得た。
（実施例５）
表１に示す凹凸模様を有する金型を使用した以外は、実施例４と同様にして成形体を得た。
（実施例６）
表１に示す凹凸模様をそれ自体の表面に有しかつ蒸気孔を有さない金型Ａと、凹凸模様を有さずかつ蒸気孔を有する金型Ｂとを型締めして構成された成形型（成形室の寸法：縦４００ｍｍ、横３００ｍｍ、奥行き２０ｍｍ）を用意した。 The appearance of the obtained molded body was evaluated according to the following evaluation criteria. The results are shown in Table 1.
-Evaluation criteria for molded product appearance-
(1) Tortoise shell pattern:
○… The turtle shell pattern is not noticeable △… A little turtle shell pattern is observed if you look closely, but the level that does not pose a problem × ・・・ The turtle shell pattern can be easily identified, and voids are also observed (2 ) Surface smoothness:
○ ・・・ Smooth and smooth surface Δ ・・・ Surface with a rough surface (Example 2)
A molded body in the same manner as in Example 1 except that a stainless wire mesh (20 mesh) having an uneven pattern shown in Table 1 is used, and polypropylene pre-expanded particles having an expansion ratio of 3.6 times and a particle diameter of 2.43 mm are used. Got.
(Example 3)
Polypropylene pre-expanded particles with an expansion ratio of 15.6 times, a particle diameter of 3.25 mm and an internal pressure of 0.10 MPa were filled into a mold using a stainless steel wire mesh (18 mesh) having the uneven pattern shown in Table 1. A molded body was obtained in the same manner as in Example 1 except that steam (vapor pressure 0.30 MPa, temperature 142 to 146 ° C.) was introduced into the molding chamber 7 for 8 seconds as the main heating.
Example 4
A molded body was obtained in the same manner as in Example 1 except that a mold having a concavo-convex pattern shown in Table 1 (dimensions of molding chamber: length 400 mm, width 300 mm, depth 20 mm) was used on the surface of the mold itself. .
(Example 5)
A molded body was obtained in the same manner as in Example 4 except that the mold having the uneven pattern shown in Table 1 was used.
(Example 6)
Molding formed by clamping a mold A having the concavo-convex pattern shown in Table 1 on its surface and not having a vapor hole and a mold B having no concavo-convex pattern and having a vapor hole A mold (dimensions of molding chamber: length 400 mm, width 300 mm, depth 20 mm) was prepared.

次に金型Ｂの蒸気孔から水蒸気（蒸気圧０．１２ＭＰａ、温度１２０〜１２４℃）を成形室に導入して予備加熱をし、１０秒間予備発泡粒子の蒸らしを行った後、成形室内の圧力がゲージ圧で、−０．０３ＭＰａ以下となるように真空ポンプを用いてドレインおよび水蒸気を吸引し、除去した。 Next, water vapor (vapor pressure 0.12 MPa, temperature 120 to 124 ° C.) is introduced into the molding chamber from the vapor hole of the mold B, preheated, and the pre-foamed particles are steamed for 10 seconds. The drain and water vapor were sucked and removed using a vacuum pump so that the pressure was a gauge pressure of −0.03 MPa or less.

その後、金型Ｂの蒸気孔から水蒸気（蒸気圧０．３５ＭＰａ、温度１４６〜１５０℃）１５秒間導入し、予備発泡粒子同士を膨張・融着させた後、３０℃の水を用いて１２０秒間冷却し、ついで金型Ａ，Ｂとを型開きして、金型Ａに接した面に、金型表面の凹凸模様に基づく模様が転写された成形体を得た。
（比較例１）
表１に示す凹凸模様を有するステンレス金網（１５０メッシュ）を使用した以外は、実施例１と同様にして成形体を得た。
（比較例２）
発泡倍率２１．１倍、粒子径３．４１ｍｍで内圧０．１２ＭＰａを付与されたポリプロピレン予備発泡粒子を表１に示す凹凸模様を有するステンレス金網（５０メッシュ）を使用した金型内に充填し、本加熱として水蒸気（蒸気圧０．２８ＭＰａ、温度１４０〜１４４℃）を成形室７に８秒間導入した以外は、実施例１と同様にして成形体を得た。
（比較例３）
表１に示す凹凸模様を金型自身の表面に有する金型を使用した以外は、実施例４と同様にして成形体を得た。 Thereafter, water vapor (vapor pressure: 0.35 MPa, temperature: 146 to 150 ° C.) is introduced from the vapor hole of the mold B for 15 seconds, and the pre-expanded particles are expanded and fused together, and then using water at 30 ° C. for 120 seconds. After cooling, the molds A and B were opened to obtain a molded body in which a pattern based on the uneven pattern on the mold surface was transferred to the surface in contact with the mold A.
(Comparative Example 1)
A molded body was obtained in the same manner as in Example 1 except that a stainless steel wire mesh (150 mesh) having an uneven pattern shown in Table 1 was used.
(Comparative Example 2)
Polypropylene pre-expanded particles having an expansion ratio of 21.1 times, a particle diameter of 3.41 mm and an internal pressure of 0.12 MPa were filled into a mold using a stainless steel wire mesh (50 mesh) having the uneven pattern shown in Table 1. A molded body was obtained in the same manner as in Example 1 except that steam (vapor pressure 0.28 MPa, temperature 140 to 144 ° C.) was introduced into the molding chamber 8 for 8 seconds as the main heating.
(Comparative Example 3)
A molded body was obtained in the same manner as in Example 4 except that a mold having the uneven pattern shown in Table 1 on the surface of the mold itself was used.

本発明の製造法に用いられる成形型の一実施態様を示す概略説明図である。It is a schematic explanatory drawing which shows one embodiment of the shaping | molding die used for the manufacturing method of this invention. 本発明に係る金型の一実施例を示す模式的断面図である。It is typical sectional drawing which shows one Example of the metal mold | die which concerns on this invention. 本発明に係る金型の一実施例を示す模式的断面図である。It is typical sectional drawing which shows one Example of the metal mold | die which concerns on this invention. 本発明に係る金型の一実施例を示す模式的断面図である。It is typical sectional drawing which shows one Example of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部断面の一実施例を示す詳細拡大図ある。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part cross section of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部断面の一実施例を示す詳細拡大図ある。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part cross section of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部断面の一実施例を示す詳細拡大図ある。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part cross section of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部断面の一実施例を示す詳細拡大図ある。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part cross section of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部の一実施例を示す詳細拡大図である。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part of the metal mold | die which concerns on this invention. 本発明に係る金型の凹凸模様形成部の一実施例を示す詳細拡大図である。It is a detailed enlarged view which shows one Example of the uneven | corrugated pattern formation part of the metal mold | die which concerns on this invention.

符号の説明Explanation of symbols

１金型Ａ
２金型Ｂ
３，４蒸気室
５，６フレーム
７成形室
８蒸気孔
９フィーダー
１０，１１蒸気ライン
１２，１３ドレンライン
１４多孔質材 1 Mold A
2 Mold B
3, 4 Steam chamber 5, 6 Frame 7 Molding chamber 8 Steam hole 9 Feeder 10, 11 Steam line 12, 13 Drain line 14 Porous material

Claims

成形金型の表面の少なくとも一部分に略規則的な凹凸模様を有する成形金型を用いた熱可塑性樹脂型内発泡成形方法において、金型表面凹凸模様の凹部幅ａおよび凹部深さｃと予備発泡粒子の粒子径Ｄが、
０．１≦ａ／Ｄ≦１．０、
かつ、
０．１≦ｃ／Ｄ≦１．０を満たすことを特徴とする熱可塑性樹脂型内発泡成形方法。 In a thermoplastic resin in-mold foam molding method using a molding die having a substantially regular concavo-convex pattern on at least a part of the surface of the molding dies, a concave width a and a concave depth c of the mold surface concavo-convex pattern and preliminary foaming The particle diameter D of the particles is
0.1 ≦ a / D ≦ 1.0,
And,
A thermoplastic resin in-mold foam molding method characterized by satisfying 0.1 ≦ c / D ≦ 1.0.

金型表面の凹凸模様において、凹部幅ａ、凸部幅ｂ、凹部深さｃが
（ｂ＋ｃ）／ａ≧０．５、
かつ、
ｃ≧ｂ
を満たす成形金型を用いることを特徴とする、請求項１記載の熱可塑性樹脂型内発泡成形方法。 In the concavo-convex pattern on the mold surface, the concave portion width a, the convex portion width b, and the concave portion depth c are (b + c) /a≧0.5,
And,
c ≧ b
The thermoplastic resin in-mold foam molding method according to claim 1, wherein a molding die satisfying the requirements is used.

粒子径Ｄが０．１ｍｍ以上２．０ｍｍ以下の熱可塑性樹脂予備発泡粒子を表面凹凸模様の凹部深さｃが０．４ｍｍ以下である成形金型を用いることを特徴とする、請求項１または２記載の熱可塑性樹脂型内発泡成形方法。 2. The molding die having a concave-convex depth c of 0.4 mm or less of the surface unevenness pattern of the thermoplastic resin pre-expanded particles having a particle diameter D of 0.1 mm to 2.0 mm, 3. The method for foam molding in a thermoplastic resin mold according to 2.

熱可塑性樹脂がポリプロピレン系樹脂またはポリエチレン系樹脂である請求項１〜３何れか一項に記載の熱可塑性樹脂型内発泡成形方法。 The thermoplastic resin in-mold foam molding method according to any one of claims 1 to 3, wherein the thermoplastic resin is a polypropylene resin or a polyethylene resin.

前記凹凸模様が成形金型の表面に形成されてなる成形金型を用いた請求項１〜４何れか一項に記載の熱可塑性樹脂型内発泡成形方法。 The thermoplastic resin in-mold foam molding method according to any one of claims 1 to 4, wherein a molding die in which the uneven pattern is formed on a surface of a molding die is used.

成形金型表面に前記凹凸模様を有しかつ蒸気孔を有さない金型Ａと、成形金型表面に前記凹凸模様を有さずかつ蒸気孔を有する金型Ｂとからなる金型を用いた請求項１〜５何れか一項に記載の熱可塑性樹脂型内発泡成形方法。 A mold comprising a mold A having the uneven pattern on the surface of the molding die and having no steam holes and a mold B having the uneven pattern on the surface of the mold and having the steam holes is used. The thermoplastic resin in-mold foam molding method according to any one of claims 1 to 5.

成形金型表面に前記凹凸模様を有しかつ蒸気孔を有さない金型Ａと成形金型表面に前記凹凸模様を有さずかつ蒸気孔を有する金型Ｂとを型締めして成形型を構成した後、熱可塑性樹脂粒子を該成形型内に充填し、金型Ｂの蒸気孔から水蒸気を供給し、該発泡粒子が互いに融着する温度よりも低い温度で該予備発泡粒子を予備加熱し、該予備発泡粒子を水蒸気で蒸らし、ついでドレインを除去した後に該予備発泡粒子が互いに融着する温度以上の温度で該予備発泡粒子を本加熱することを特徴とする請求項１〜６何れか一項に記載の熱可塑性樹脂型内発泡成形方法。 A mold A is formed by clamping a mold A having the concavo-convex pattern on the surface of the molding die and having no steam holes and a mold B having the concavo-convex pattern on the surface of the molding mold and having the steam holes. After that, the thermoplastic resin particles are filled in the mold, water vapor is supplied from the vapor holes of the mold B, and the pre-expanded particles are preliminarily prepared at a temperature lower than the temperature at which the expanded particles are fused to each other. The pre-foamed particles are heated at a temperature equal to or higher than a temperature at which the pre-foamed particles are fused to each other after heating, steaming the pre-foamed particles with water vapor, and then removing the drain. The thermoplastic resin in-mold foam molding method according to any one of the above.

請求項１〜７何れか一項に記載の製造方法により製造される熱可塑性樹脂型内発泡成形体。 A thermoplastic resin in-mold foam molded product produced by the production method according to claim 1.