JPH09124830A - Preliminary foamed particle of polypropylene-based resin and its production - Google Patents
Preliminary foamed particle of polypropylene-based resin and its productionInfo
- Publication number
- JPH09124830A JPH09124830A JP7284794A JP28479495A JPH09124830A JP H09124830 A JPH09124830 A JP H09124830A JP 7284794 A JP7284794 A JP 7284794A JP 28479495 A JP28479495 A JP 28479495A JP H09124830 A JPH09124830 A JP H09124830A
- Authority
- JP
- Japan
- Prior art keywords
- polypropylene
- resin
- polypropylene resin
- particles
- expanded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、生産性に優れ、耐
熱性、機械的強度、衝撃特性、軽量性、経済性に優れた
型内発泡成形体が得られるポリプロピレン系樹脂予備発
泡粒子及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polypropylene resin pre-expanded particles which are excellent in productivity, and which can provide an in-mold expanded molded article excellent in heat resistance, mechanical strength, impact characteristics, lightness and economy. It relates to a manufacturing method.
【０００２】[0002]
【従来の技術と発明が解決しようとする課題】発泡剤を
含有する熱可塑性樹脂予備発泡粒子を型内で加熱成形し
て所望の形状の成形体を得る方法が知られている。特に
ポリプロピレン系樹脂を基材樹脂に使用した成形体は、
耐熱性、機械的強度、衝撃特性のバランスに優れてい
る。2. Description of the Related Art A method is known in which a thermoplastic resin pre-expanded particle containing a foaming agent is heat-molded in a mold to obtain a molded product having a desired shape. In particular, molded products using polypropylene resin as the base resin,
Excellent balance of heat resistance, mechanical strength and impact characteristics.
【０００３】しかし、このポリプロピレン系樹脂型内成
形体を得るための予備発泡粒子を得るには、従来、
（１）ポリプロピレン系樹脂を造粒する工程、（２）発
泡剤を加圧含浸する工程、および（３）除圧発泡により
予備発泡粒子を製造する工程からなる方法によってい
た。このため設備が大型化し、その取得費用が高額にな
り、また広い設置面積が必要になるという問題があっ
た。またバッチ式であるために、生産性が悪いだけでな
く、容器内に残留する樹脂粒子量が少なくなってから得
られるもの、すなわち予備発泡の最後の方で得られるも
のと初期に得られるものとの発泡倍率が異なり、品質の
均一性を維持するのが困難であった。さらには大量に予
備発泡粒子を得ようとする場合、上記（１）〜（３）の
一連の工程を繰り返す必要があり、特に加熱、冷却の操
作を毎回行わなければならないために熱効率が非常に悪
く、エネルギー消費が膨大になるという問題もあった。However, in order to obtain the pre-expanded particles for obtaining the polypropylene-based resin in-mold molded article, conventionally,
The method comprises a step of (1) granulating a polypropylene resin, (2) a step of pressure-impregnating a foaming agent, and (3) a step of producing pre-expanded particles by depressurizing foaming. Therefore, there is a problem that the equipment becomes large, the acquisition cost becomes high, and a large installation area is required. Also, since it is a batch system, not only the productivity is poor, but also those obtained after the amount of resin particles remaining in the container is small, that is, those obtained at the end of pre-foaming and those obtained at the initial stage. It was difficult to maintain the uniformity of quality because the foaming ratios of and were different. Furthermore, when a large amount of pre-expanded particles are to be obtained, it is necessary to repeat the series of steps (1) to (3), and in particular, heating and cooling operations must be performed every time, so that the thermal efficiency is very high. There was also the problem that energy consumption was enormous.
【０００４】このような欠点を改良すべく、従来より種
々の提案が成されている。例えば、特開昭６０−１６８
６１０号公報、特開昭５９−６７０２２号公報、特開昭
５９−８５７２４号公報には、上記（１）〜（３）の工
程の全部または一部を連続式で行う方法が提案されてい
る。しかしながら、これらの方法でもなお設備の大型化
は避けられず、設備の設置場所が制限され、このように
して得られた予備発泡粒子を用いた成形体はやはり高コ
ストとなる。Various proposals have heretofore been made to improve such drawbacks. For example, JP-A-60-168
JP-A No. 610, JP-A-59-67022 and JP-A-59-85724 propose a method in which all or some of the steps (1) to (3) are carried out continuously. . However, even with these methods, it is inevitable that the equipment becomes large in size, the installation place of the equipment is limited, and the molded product using the pre-expanded particles obtained in this way is also expensive.
【０００５】一方、特開平６−２３４８７８号公報に
は、押出機中、発泡剤の存在下で溶融強度５〜４０ＣＮ
のポリプロピレン系樹脂を押出し、発泡ストランドを得
た後カットして予備発泡粒子を得る方法が開示されてい
る。このような押出発泡ストランドをカットして予備発
泡粒子を得る方法、すなわち押出発泡ビーズ法による
と、確かに前記予備発泡粒子製造工程（１）〜（３）を
一工程に簡略化でき、連続生産が可能となるので、この
方法は生産性の点では比較的優秀である。また、ポリプ
ロピレン系樹脂が架橋していないため、リサイクル性も
良好である。しかしながら、この方法で用いられるポリ
プロピレン系樹脂は、高分子鎖の一部が枝分かれしてい
る重合体、すなわち一方の末端のみが高分子鎖に結合し
ている側鎖を有する重合体であり、このような重合体を
得るにはプロピレンの重合後、電子線照射するか又は特
定の有機過酸化物で処理する必要がある。従って、その
ための高価な処理設備が必要になり、また架橋しないよ
うに精密に制御しなければならないので、原料樹脂の価
格が高くなってしまい、成形体トータルコストでは必ず
しも安価にならない。On the other hand, Japanese Patent Laid-Open No. 6-234878 discloses a melt strength of 5 to 40CN in an extruder in the presence of a foaming agent.
Of polypropylene resin is extruded to obtain expanded strands and then cut to obtain pre-expanded particles. According to the method for obtaining pre-expanded beads by cutting such extruded expanded strands, that is, the extruded expanded beads method, the pre-expanded beads manufacturing steps (1) to (3) can be certainly simplified into one step, and continuous production can be performed. This method is relatively excellent in terms of productivity. Further, since the polypropylene resin is not crosslinked, the recyclability is also good. However, the polypropylene resin used in this method is a polymer in which a part of the polymer chain is branched, that is, a polymer having a side chain in which only one end is bonded to the polymer chain, In order to obtain such a polymer, it is necessary to carry out electron beam irradiation or treatment with a specific organic peroxide after the polymerization of propylene. Therefore, an expensive processing facility for that purpose is required, and since it must be precisely controlled so as not to crosslink, the price of the raw material resin becomes high, and the total cost of the molded body is not necessarily low.
【０００６】[0006]
【課題を解決するための手段】本発明者等は、以上のよ
うな問題の解決を図るため鋭意検討した結果、本発明を
完成するに至った。すなわち、請求項１のポリプロピレ
ン系樹脂予備発泡粒子は、上記の課題を解決するため
に、ポリプロピレン系樹脂７０〜９９重量％と１，２−
ポリブタジエン樹脂１〜３０重量％とからなる混合物を
基材樹脂とし、発泡倍率を１．１〜７０倍、独立気泡率
を６５％以上、気泡径を５０〜２，０００μｍとする。The inventors of the present invention have completed the present invention as a result of intensive studies to solve the above problems. That is, in order to solve the above-mentioned problems, the polypropylene resin pre-expanded particles of claim 1 have a polypropylene resin content of 70 to 99% by weight and 1,2-
A mixture of 1 to 30% by weight of polybutadiene resin is used as a base resin, a foaming ratio is 1.1 to 70 times, a closed cell ratio is 65% or more, and a cell diameter is 50 to 2,000 μm.
【０００７】請求項２のものは、請求項１のポリプロピ
レン系樹脂予備発泡粒子において、前記ポリプロピレン
系樹脂を２３０℃におけるメルトインデックスが０．１
〜１０ｇ／１０分のものとする。According to a second aspect, in the polypropylene resin pre-expanded particles according to the first aspect, the polypropylene resin has a melt index of 0.1 at 230 ° C.
-10 g / 10 minutes.
【０００８】請求項３のものは、請求項１のポリプロピ
レン系樹脂予備発泡粒子において、前記ポリプロピレン
系樹脂をプロピレンとエチレンのランダムコポリマーま
たはプロピレン、エチレン、ブテンのランダムターポリ
マーとする。According to a third aspect, in the polypropylene resin pre-expanded particles according to the first aspect, the polypropylene resin is a random copolymer of propylene and ethylene or a random terpolymer of propylene, ethylene and butene.
【０００９】請求項４のものは、請求項１のポリプロピ
レン系樹脂予備発泡粒子の１３０〜１４０℃における熱
キシレン不溶分が２重量％以上となるようにする。According to a fourth aspect of the present invention, the hot-xylene-insoluble content of the polypropylene resin pre-expanded particles of the first aspect at 130 to 140 ° C. is 2% by weight or more.
【００１０】請求項５のポリプロピレン系樹脂予備発泡
粒子の製造方法は、ポリプロピレン系樹脂と１，２−ポ
リブタジエン樹脂からなる混合物と発泡剤とを、１，２
−ポリブタジエンの少なくとも一部が熱反応して、得ら
れる予備発泡粒子の１３０〜１４０℃における熱キシレ
ン不溶分が２重量％以上になるような温度で高圧下溶融
混練した後、低圧域に押出して発泡ストランドとし、次
いで該発泡ストランドをカットして発泡粒子とする。The method for producing pre-expanded polypropylene resin particles according to claim 5 is characterized in that a mixture of polypropylene resin and 1,2-polybutadiene resin and a foaming agent are added to 1,2.
At least a part of the polybutadiene is thermally reacted, and the resulting pre-expanded particles are melt-kneaded under a high pressure at a temperature such that a thermal xylene insoluble content at 130 to 140 ° C. is 2% by weight or more, and then extruded into a low pressure region. A foamed strand is formed, and then the foamed strand is cut into foamed particles.
【００１１】請求項６の製造方法は、請求項５の製造方
法において、前記発泡剤を、沸点が−５０〜１００℃の
炭化水素もしくはハロゲン化炭化水素、または無機ガス
から選択される１種以上の物理発泡剤とする。The manufacturing method of claim 6 is the manufacturing method of claim 5, wherein the foaming agent is one or more selected from hydrocarbons or halogenated hydrocarbons having a boiling point of -50 to 100 ° C., or an inorganic gas. The physical foaming agent of
【００１２】[0012]
【発明の実施の形態】本発明で用いられるポリプロピレ
ン系樹脂は、そのメルトインデックス（ＪＩＳ−Ｋ−６
７５８に従い、２３０℃、荷重２．１６ｋｇで測定した
もの）が０．１〜１０ｇ／１０分であることが好まし
い。メルトインデックスが０．１未満では基材樹脂その
ものの溶融時の流動性が不足し、発泡能力を有しない。
メルトインデックスが１０を越えると、予備発泡粒子の
気泡径が不均一になり易く、場合によっては気泡が破壊
して独立気泡率が低下する。さらに、そのような予備発
泡粒子を使用した成形品は、ひけの発生や寸法収縮のた
めに外観が損われる。BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene resin used in the present invention has a melt index (JIS-K-6).
According to 758, it is preferably 0.1 to 10 g / 10 minutes, measured at 230 ° C. and a load of 2.16 kg. When the melt index is less than 0.1, the fluidity of the base resin itself at the time of melting is insufficient and the base resin has no foaming ability.
If the melt index exceeds 10, the bubble diameter of the pre-expanded particles tends to be non-uniform, and in some cases, the bubbles are broken to reduce the closed cell rate. Further, the molded article using such pre-expanded particles has a poor appearance due to sink marks and dimensional shrinkage.
【００１３】上記ポリプロピレン系樹脂としては、ポリ
プロピレンホモポリマー、プロピレンと一種以上の他の
ビニルモノマーとのコポリマーまたはターポリマー等が
いずれも用いられるが、発泡成形時の発泡粒子相互の融
着性、発泡成形時の温度があまり高くならないことを考
慮すると、プロピレンとエチレンのランダムコポリマー
またはプロピレン、エチレン、ブテンのランダムターポ
リマーが好ましい。これらは単独で使用しても、混合し
て使用してもよい。さらに、本発明の効果を損わない範
囲で、他の熱可塑性樹脂を混合してもよい。As the polypropylene resin, polypropylene homopolymers, copolymers of propylene and one or more other vinyl monomers, terpolymers and the like can be used. A random copolymer of propylene and ethylene or a random terpolymer of propylene, ethylene and butene is preferable in view of the fact that the temperature during molding does not become too high. These may be used alone or as a mixture. Further, another thermoplastic resin may be mixed within a range that does not impair the effects of the present invention.
【００１４】また、本発明で用いられる１，２−ポリブ
タジエン樹脂としては、ビニル構造（１，２結合量）を
７０％以上含み、トルエン中３０℃で測定した固有粘度
が０．７以上、融点が４０℃以上、結晶化度が１０〜４
０％のものが好ましい。The 1,2-polybutadiene resin used in the present invention contains 70% or more of a vinyl structure (1,2 bond amount), has an intrinsic viscosity of 0.7 or more measured at 30 ° C. in toluene, and a melting point. Is 40 ° C or higher, and the crystallinity is 10 to 4
It is preferably 0%.
【００１５】上記ポリプロピレン系樹脂と１，２−ポリ
ブタジエン樹脂との混合比率は、両者の混合物中の１，
２−ポリブタジエン樹脂の比率を１〜３０重量％とし、
より好ましくは５〜２０重量％とする。１，２−ポリブ
タジエン樹脂の混合比率が１重量％未満では、熱反応量
が少なすぎるためポリプロピレン系樹脂の溶融粘弾性改
質効果が不充分で本発明の発泡特性が得られない。ま
た、１，２−ポリブタジエン樹脂の混合比率が３０重量
％を越えた場合には、未反応の１，２−ポリブタジエン
量が増加し、機械的強度が低下するので好ましくない。The mixing ratio of the polypropylene-based resin and the 1,2-polybutadiene resin is 1,2 in the mixture of the two.
The ratio of 2-polybutadiene resin is 1 to 30% by weight,
It is more preferably 5 to 20% by weight. When the mixing ratio of the 1,2-polybutadiene resin is less than 1% by weight, the amount of thermal reaction is too small and the effect of modifying the melt-viscoelasticity of the polypropylene resin is insufficient and the foaming characteristics of the present invention cannot be obtained. Further, when the mixing ratio of the 1,2-polybutadiene resin exceeds 30% by weight, the amount of unreacted 1,2-polybutadiene increases and the mechanical strength decreases, which is not preferable.
【００１６】本発明では発泡剤として通常の物理発泡剤
が特に制限なく用いられる。すなわち、沸点が−５０〜
１００℃の炭化水素、ハロゲン化炭化水素、または無機
ガス等である。前記炭化水素の例としては、プロパン、
ブタン、ペンタン、ヘキサン、ヘプタン等が挙げられ
る。前記ハロゲン化炭化水素の例としては、ジクロロジ
フルオロメタン、トリクロロモノフルオロメタン、ジク
ロロメタン、モノクロロメタン、ジクロロテトラフルオ
ロエタン、トリクロロトリフルオロエタン、テトラフル
オロエタン、ジフルオロエタン、パーフルオロシクロブ
タン等が挙げられる。前記無機ガスの例としては、空
気、窒素、アルゴン、ヘリウム、ネオン、炭酸ガス、水
蒸気等が挙げられる。中でも、炭化水素としてブタン
が、ハロゲン化炭化水素ではテトラフルオロエタンが、
無機ガスでは炭酸ガスが、発泡特性、成形品の品質、経
済性および環境適合性の点で好ましい。In the present invention, an ordinary physical foaming agent is used as the foaming agent without particular limitation. That is, the boiling point is -50 to
It is a hydrocarbon at 100 ° C., a halogenated hydrocarbon, an inorganic gas, or the like. Examples of the hydrocarbon include propane,
Butane, pentane, hexane, heptane and the like can be mentioned. Examples of the halogenated hydrocarbon include dichlorodifluoromethane, trichloromonofluoromethane, dichloromethane, monochloromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, tetrafluoroethane, difluoroethane, perfluorocyclobutane and the like. Examples of the inorganic gas include air, nitrogen, argon, helium, neon, carbon dioxide, water vapor and the like. Among them, butane as a hydrocarbon and tetrafluoroethane as a halogenated hydrocarbon,
Of the inorganic gases, carbon dioxide is preferred in terms of foaming characteristics, molded product quality, economic efficiency and environmental compatibility.
【００１７】なお、本発明では上記発泡剤以外に、分散
剤、気泡調整剤、滑剤、結晶核剤、帯電防止剤、着色
剤、安定剤等の添加剤が適宜用いられる。In the present invention, in addition to the above foaming agent, additives such as a dispersant, a cell regulator, a lubricant, a crystal nucleating agent, an antistatic agent, a coloring agent and a stabilizer are appropriately used.
【００１８】本発明の予備発泡粒子の発泡倍率は１．１
〜７０倍が好ましく、より好ましくは５〜６０倍であ
る。発泡倍率が１．１倍未満では、緩衝特性、軽量性が
不充分であり、経済性の面でも好ましくない。７０倍を
越えると気泡径が大きくなり過ぎ、歪んで不均一にな
り、しかも機械的強度が低下するので好ましくない。The expansion ratio of the pre-expanded particles of the present invention is 1.1.
˜70 times, more preferably 5 to 60 times. If the expansion ratio is less than 1.1 times, the cushioning property and the lightness are insufficient, which is not preferable in terms of economy. If it exceeds 70 times, the bubble diameter becomes too large, distorted and non-uniform, and the mechanical strength decreases, which is not preferable.
【００１９】本発明の予備発泡粒子の独立起泡率は６５
％以上が好ましく、より好ましくは８０％以上である。
独立起泡率が６５％未満では、成形時の二次発泡性、緩
衝特性、機械的強度が不充分で好ましくない。The independent foaming ratio of the pre-expanded particles of the present invention is 65.
% Or more, more preferably 80% or more.
When the independent foaming ratio is less than 65%, the secondary foaming property at the time of molding, the cushioning property, and the mechanical strength are insufficient, which is not preferable.
【００２０】本発明の予備発泡粒子の気泡径は５０〜
２，０００μｍが好ましく、より好ましくは１００〜
１，０００μｍである。気泡径が５０μｍ未満では耐熱
性、機械的強度が不充分であり、２，０００μｍを越え
ると緩衝特性が低下するので好ましくない。The pre-expanded particles of the present invention have a cell diameter of 50 to 50.
2,000 μm is preferable, and more preferably 100 to
It is 1,000 μm. If the cell diameter is less than 50 μm, heat resistance and mechanical strength are insufficient, and if it exceeds 2,000 μm, the buffering property is deteriorated, which is not preferable.
【００２１】本発明の予備発泡粒子は、ポリプロピレン
系樹脂と１，２−ポリブタジエン樹脂とからなる混合物
と発泡剤とを、押出機等で高温押圧下で溶融混練の後、
多孔ダイ等から低圧域に押出し、発泡させて発泡ストラ
ンドとし、次いで該発泡ストランドをカットすることに
よって得られる。ここで、１，２−ポリブタジエン樹脂
の作用は必ずしも明確でないが、１，２−ポリブタジエ
ン樹脂の側鎖ビニル基の分子間架橋及び／又は分子内環
化を生起する熱反応によって、ポリプロピレン系樹脂が
本来有する発泡時の溶融粘弾性の急激な変化を緩和する
効果を有し、それが発泡特性を改良するものと考えられ
る。したがって、樹脂混合物を押出機等で溶融混練する
際の温度は、１，２−ポリブタジエンの一部または全部
が熱反応する温度にする必要がある。具体的には、押出
機の構造、混練時間、１，２−ポリブタジエン樹脂の混
合量等により変化するので、一概には決まらないが、得
られる予備発泡粒子の１３０〜１４０℃における熱キシ
レン不溶分が２重量％以上になるような温度にするのが
好ましい。The pre-expanded particles of the present invention are obtained by melt-kneading a mixture of a polypropylene-based resin and 1,2-polybutadiene resin and a foaming agent under high temperature pressing with an extruder or the like.
It is obtained by extruding from a porous die or the like into a low pressure region, foaming to form a foamed strand, and then cutting the foamed strand. Here, although the action of the 1,2-polybutadiene resin is not always clear, the polypropylene-based resin is changed by a thermal reaction that causes intermolecular crosslinking and / or intramolecular cyclization of a side chain vinyl group of the 1,2-polybutadiene resin. It has an effect of alleviating a sudden change in melt viscoelasticity at the time of inherent foaming, which is considered to improve foaming characteristics. Therefore, the temperature at which the resin mixture is melt-kneaded by an extruder or the like needs to be a temperature at which a part or the whole of 1,2-polybutadiene thermally reacts. Specifically, it varies depending on the structure of the extruder, the kneading time, the mixing amount of the 1,2-polybutadiene resin, and the like, so it is not unconditionally determined, but the heat-xylene-insoluble content of the obtained pre-expanded particles at 130 to 140 ° C. Is preferably 2% by weight or more.
【００２２】上記ポリプロピレン系樹脂と１，２−ポリ
ブタジエン樹脂とは、リボンブレンダー等でドライブレ
ンドの後、直接押出機等に供給してもよいし、予め別途
押出機等で溶融混練しておいたものを使用してもよい。The polypropylene resin and the 1,2-polybutadiene resin may be directly dry blended with a ribbon blender or the like and then directly supplied to an extruder or the like, or may be melt-kneaded separately with an extruder or the like in advance. You may use the thing.
【００２３】押し出された発泡ストランドをカットする
方法は種々あるが、多孔ダイから出て発泡しつつある際
に冷却しつつカットする、いわゆるホットカット方式
が、得られた予備発泡粒子の形状が丸みを帯び、型内へ
の充填がスムーズに行いやすい点から好ましい。There are various methods of cutting the extruded foamed strands, but a so-called hot cut method of cutting while extruding from a porous die and foaming is a so-called hot-cutting method, in which the shape of the obtained pre-expanded particles is round. It is preferable because it is easy to fill the mold smoothly.
【００２４】上記のようにして得られた本発明の予備発
泡粒子は、通常の養生後、必要に応じて内圧付与し、成
形金型に充填して加熱発泡成形することができる。The pre-expanded particles of the present invention obtained as described above can be subjected to ordinary curing, then, if necessary, given an internal pressure, filled in a molding die and heat-foam molded.
【００２５】[0025]
【実施例】次に実施例を挙げて本発明を具体的に説明す
るが、本発明はこれに限定されるものではない。EXAMPLES Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
【００２６】実施例１ バレルの途中に物理発泡剤圧入用のバレル孔を有する４
０ｍｍφ押出機と５０ｍｍφ押出機とを連結した発泡用
押出設備に、プロピレンとエチレンのランダムコポリマ
ー（ＭＩ５、エチレン含有量３．５モル％）８ｋｇ、
１，２−ポリブタジエン樹脂（ＪＳＲ、ＲＢ８２０、１
５０℃のメルトインデックス３）２ｋｇ、気泡調整剤と
してタルク１００ｇをリボンブレンダーでドライブレン
ドしたものを、溶融混練ゾーンが２５０℃に保持されて
いる４０ｍｍφ押出機のホッパーを通して１０ｋｇ／時
で供給し、４０ｍｍφ押出機のバレル孔より発泡剤とし
てブタン（イソ／ｎ＝１５／８５、ただし重量比）を
１．７ｋｇ／時で圧入した。５０ｍｍφの押出機の先端
には断面形状が円形で１ｍｍφ孔を１６個有する多孔ダ
イを装着し、該多孔ダイに接して回転刃を有するペレッ
トカッターを設けた。溶融混練され、多孔ダイから押出
された発泡ストランドはペレットカッターによって切断
され、断面がほぼ円形で、丸みを帯びた円筒状の４ｍｍ
×５ｍｍの予備発泡粒子が得られた。この予備発泡粒子
は発泡倍率が３１倍、独立気泡率が８６％、気泡径が３
００μｍであり、均一気泡構造を有していた。この予備
発泡粒子を１３０〜１４０℃の熱キシレンに２％溶液に
なるよう溶解し、温度が低下しないように素早く、熱時
遠心分離を２回以上繰り返して不溶分を採取した。この
不溶分は予備発泡粒子全体の５．４重量％であった。 Example 1 4 having a barrel hole for inserting a physical foaming agent in the middle of a barrel
8 kg of a random copolymer of propylene and ethylene (MI5, ethylene content 3.5 mol%) was added to an extrusion equipment for foaming in which a 0 mmφ extruder and a 50 mmφ extruder were connected.
1,2-polybutadiene resin (JSR, RB820, 1,
Melt index 3) at 50 ° C. 2 kg and talc 100 g as a cell adjuster dry-blended with a ribbon blender are supplied at a rate of 10 kg / hour through a hopper of 40 mmφ extruder whose melt-kneading zone is maintained at 250 ° C. Butane (iso / n = 15/85, but weight ratio) was injected at 1.7 kg / hour as a foaming agent from the barrel hole of the extruder. A porous die having a circular cross-sectional shape and having 16 1 mmφ holes was attached to the tip of an extruder of 50 mmφ, and a pellet cutter having a rotary blade was provided in contact with the porous die. The foamed strand that was melt-kneaded and extruded from the perforated die was cut by a pellet cutter, and its cross section was almost circular and rounded cylindrical 4 mm.
Pre-expanded particles of × 5 mm were obtained. The pre-expanded particles had an expansion ratio of 31, a closed cell ratio of 86%, and a cell diameter of 3
It was 00 μm and had a uniform cell structure. The pre-expanded particles were dissolved in hot xylene at 130 to 140 ° C. to form a 2% solution, and the insoluble matter was rapidly collected by repeating the centrifugation under heat twice or more so as not to lower the temperature. This insoluble content was 5.4% by weight based on the whole pre-expanded particles.
【００２７】この予備発泡粒子を温度８０℃、圧力２５
ｋｇ／ｃｍ2 （ゲージ圧）の窒素加圧雰囲気下に３時間
保持して発泡粒子内に窒素を含浸して内圧付与し、次い
で成形用金型に充填し、３．５ｋｇ／ｃｍ2 の水蒸気で
４０秒間加熱して成形体を得た。得られた成形体は、密
度２２ｇ／Ｌで、各粒子がよく融着し、表面平滑であっ
た。The pre-expanded particles were heated at a temperature of 80 ° C. and a pressure of 25.
The foamed particles are kept under a nitrogen pressure atmosphere of kg / cm 2 (gauge pressure) for 3 hours to impregnate the expanded particles with nitrogen to give an internal pressure, and then filled in a molding die, and steam of 3.5 kg / cm 2 is added. Was heated for 40 seconds to obtain a molded body. The obtained molded product had a density of 22 g / L, and the particles were well fused and the surface was smooth.
【００２８】実施例２ ポリプロピレン系樹脂をプロピレン、エチレン、ブテン
のランダムターポリマー（ＭＩ６、エチレン含有量４．
０モル％）に代えた以外は、実施例１と同様にして、断
面がほぼ円形で、丸みを帯びた円筒状の５ｍｍ×５ｍｍ
の予備発泡粒子を得た。この予備発泡粒子は発泡倍率が
５０倍、独立気泡率が８２％、気泡径が６００μｍであ
り、均一気泡構造を有していた。熱キシレン不溶分は
６．２重量％であった。 Example 2 A polypropylene resin is a random terpolymer of propylene, ethylene and butene (MI6, ethylene content 4.
5 mm × 5 mm having a substantially circular cross section and a rounded cylindrical shape, in the same manner as in Example 1 except that the content of C is 0 mol%).
Thus, pre-expanded particles of The pre-expanded particles had an expansion ratio of 50 times, a closed cell ratio of 82%, a cell diameter of 600 μm, and had a uniform cell structure. The thermal xylene insoluble content was 6.2% by weight.
【００２９】この予備発泡粒子を温度８０℃、圧力２５
ｋｇ／ｃｍ2 （ゲージ圧）の窒素加圧雰囲気下に３時間
保持して発泡粒子内に窒素を含浸して内圧付与し、次い
で成形用金型に充填し、２．５ｋｇ／ｃｍ2 の水蒸気で
４０秒間加熱して成形体を得た。得られた成形体は、密
度１５ｇ／Ｌで、各粒子がよく融着し、表面平滑であっ
た。The pre-expanded particles were heated at a temperature of 80 ° C. and a pressure of 25.
The foamed particles were kept under a nitrogen pressure atmosphere of kg / cm 2 (gauge pressure) for 3 hours to impregnate nitrogen into the expanded particles to give an internal pressure, and then filled in a molding die, and 2.5 kg / cm 2 of steam was added. Was heated for 40 seconds to obtain a molded body. The obtained molded product had a density of 15 g / L, and the particles were well fused and the surface was smooth.
【００３０】実施例３ ポリプロピレン系樹脂をプロピレンとエチレンのランダ
ムコポリマー（ＭＩ０．５、エチレン含有量３．２モル
％）に代えた以外は、実施例１と同様にして、断面がほ
ぼ円形で、丸みを帯びた円筒状の３ｍｍ×４ｍｍの予備
発泡粒子を得た。この予備発泡粒子は発泡倍率が１５
倍、独立気泡率が９５％、気泡径が２００μｍであり、
均一気泡構造を有していた。熱キシレン不溶分は５．７
重量％であった。 Example 3 The procedure of Example 1 was repeated, except that the polypropylene resin was replaced by a random copolymer of propylene and ethylene (MI 0.5, ethylene content 3.2 mol%), and the cross section was substantially circular. Rounded cylindrical pre-expanded particles of 3 mm × 4 mm were obtained. The pre-expanded particles have an expansion ratio of 15
Double, the closed cell ratio is 95%, the bubble diameter is 200 μm,
It had a uniform cell structure. Thermal xylene insoluble content is 5.7
% By weight.
【００３１】この予備発泡粒子を温度８０℃、圧力２５
ｋｇ／ｃｍ2 （ゲージ圧）の窒素加圧雰囲気下に３時間
保持して発泡粒子内に窒素を含浸して内圧付与し、次い
で成形用金型に充填し、３．５ｋｇ／ｃｍ2 の水蒸気で
４０秒間加熱して成形体を得た。得られた成形体は、密
度３６ｇ／Ｌで、各粒子がよく融着し、表面平滑であっ
た。The pre-expanded particles were heated at a temperature of 80 ° C. and a pressure of 25.
The foamed particles are kept under a nitrogen pressure atmosphere of kg / cm 2 (gauge pressure) for 3 hours to impregnate the expanded particles with nitrogen to give an internal pressure, and then filled in a molding die, and steam of 3.5 kg / cm 2 is added. Was heated for 40 seconds to obtain a molded body. The obtained molded product had a density of 36 g / L, and the particles were well fused and the surface was smooth.
【００３２】比較例１ １，２−ポリブタジエン樹脂を使用しない以外は、実施
例１と同様にして、断面がほぼ円形で、丸みを帯びた円
筒状の３ｍｍ×５ｍｍの予備発泡粒子を得た。この予備
発泡粒子は発泡倍率が２５倍、独立気泡率が３５％、気
泡径が７００〜３，０００μｍであり、気泡状態が不均
一であった。熱キシレン不溶分は認められなかった。 Comparative Example 1 In the same manner as in Example 1 except that the 1,2-polybutadiene resin was not used, pre-expanded particles having a substantially circular cross section and a rounded cylindrical shape of 3 mm × 5 mm were obtained. The pre-expanded particles had an expansion ratio of 25 times, a closed cell ratio of 35%, a cell diameter of 700 to 3,000 μm, and the cell state was non-uniform. No hot xylene insoluble matter was observed.
【００３３】この予備発泡粒子を温度８０℃、圧力２５
ｋｇ／ｃｍ2 （ゲージ圧）の窒素加圧雰囲気下に３時間
保持して発泡粒子内に窒素を含浸して内圧付与し、次い
で成形用金型に充填し、４．０ｋｇ／ｃｍ2 の水蒸気で
４０秒間加熱して成形体を得た。得られた成形体は、密
度２５ｇ／Ｌで、表面のひけや変形が見られ、各粒子間
の付着性も悪かった。The pre-expanded particles were heated at a temperature of 80 ° C. and a pressure of 25.
kg / cm 2 (gauge pressure) under nitrogen pressurization atmosphere maintained for 3 hours to pressure imparted by nitrogen was impregnated into the foamed particles, and then filled in a mold, of 4.0 kg / cm 2 steam Was heated for 40 seconds to obtain a molded body. The obtained molded product had a density of 25 g / L, the surface had sink marks and deformation, and the adhesion between the particles was poor.
【００３４】[0034]
【発明の効果】本願請求項１〜４の予備発泡粒子によれ
ば、耐熱性、機械的強度、緩衝特性、軽量性等に優れ、
特に緩衝材、断熱材、包装材等として好適に使用される
樹脂成形体が得られる。この成形体は基材樹脂のポリプ
ロピレン系樹脂が架橋していないためリサイクル性にも
優れている。The pre-expanded particles according to claims 1 to 4 of the present invention are excellent in heat resistance, mechanical strength, cushioning characteristics, lightness, etc.
In particular, a resin molded body that is suitably used as a cushioning material, a heat insulating material, a packaging material, etc. can be obtained. This molded article has excellent recyclability because the polypropylene resin as the base resin is not crosslinked.
【００３５】請求項５および６の予備発泡粒子の製造方
法によれば、上記請求項１〜４の予備発泡粒子が容易に
得られる。また、この製造方法は、工程が連続式で簡略
化されているので、従来のような大型の設備や、電子線
照射等の特別な後処理設備を必要とせず、生産性、経済
性に優れている。According to the method for producing pre-expanded particles of claims 5 and 6, the pre-expanded particles of claims 1 to 4 can be easily obtained. In addition, this manufacturing method does not require large-scale equipment like conventional ones or special post-treatment equipment such as electron beam irradiation because the process is simplified by a continuous process, and is excellent in productivity and economic efficiency. ing.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ２９Ｋ 9:00 23:00 105:04 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display area B29K 9:00 23:00 105: 04
Claims (6)
と１，２−ポリブタジエン樹脂１〜３０重量％とからな
る混合物を基材樹脂とし、発泡倍率が１．１〜７０倍で
あり、独立気泡率が６５％以上であり、気泡径が５０〜
２，０００μｍであるポリプロピレン系樹脂予備発泡粒
子。1. Polypropylene resin 70 to 99% by weight
And a 1,2-polybutadiene resin 1 to 30% by weight as a base resin, the expansion ratio is 1.1 to 70 times, the closed cell ratio is 65% or more, and the cell diameter is 50 to.
Polypropylene resin pre-expanded particles of 2,000 μm.
おけるメルトインデックスが０．１〜１０ｇ／１０分で
あることを特徴とする請求項１に記載のポリプロピレン
系樹脂予備発泡粒子。2. The polypropylene resin pre-expanded particles according to claim 1, wherein the polypropylene resin has a melt index at 230 ° C. of 0.1 to 10 g / 10 minutes.
とエチレンのランダムコポリマーまたはプロピレン、エ
チレン、ブテンのランダムターポリマーであることを特
徴とする請求項１に記載のポリプロピレン系樹脂予備発
泡粒子。3. The polypropylene resin pre-expanded particles according to claim 1, wherein the polypropylene resin is a random copolymer of propylene and ethylene or a random terpolymer of propylene, ethylene and butene.
の１３０〜１４０℃における熱キシレン不溶分が２重量
％以上であることを特徴とする請求項１に記載のポリプ
ロピレン系樹脂予備発泡粒子。4. The polypropylene-based resin pre-expanded particles according to claim 1, wherein the polypropylene-based resin pre-expanded particles have a thermal xylene insoluble content at 130 to 140 ° C. of 2% by weight or more.
タジエン樹脂からなる混合物と発泡剤とを、１，２−ポ
リブタジエンの少なくとも一部が熱反応して、得られる
予備発泡粒子の１３０〜１４０℃における熱キシレン不
溶分が２重量％以上になるような温度で高圧下溶融混練
した後、低圧域に押出して発泡ストランドとし、次いで
該発泡ストランドをカットして発泡粒子とすることを特
徴とするポリプロピレン系樹脂予備発泡粒子の製造方
法。5. Pre-expanded particles obtained by thermally reacting a mixture of a polypropylene resin and 1,2-polybutadiene resin and a foaming agent with at least a part of 1,2-polybutadiene at 130 to 140 ° C. A polypropylene system characterized by being melt-kneaded under a high pressure at a temperature such that the content of insoluble matter in hot xylene is 2% by weight or more, and then extruded into a low pressure region to obtain a foamed strand, and then the foamed strand is cut into foamed particles. Method for producing pre-expanded resin particles.
の炭化水素もしくはハロゲン化炭化水素、または無機ガ
スから選択される１種以上の物理発泡剤であることを特
徴とする請求項５に記載のポリプロピレン系樹脂予備発
泡粒子の製造方法。6. The boiling point of the foaming agent is −50 to 100 ° C.
6. The method for producing pre-expanded polypropylene resin particles according to claim 5, wherein the pre-expanded polypropylene resin particles are one or more kinds of physical foaming agents selected from the hydrocarbons or halogenated hydrocarbons described above, or an inorganic gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7284794A JPH09124830A (en) | 1995-11-01 | 1995-11-01 | Preliminary foamed particle of polypropylene-based resin and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7284794A JPH09124830A (en) | 1995-11-01 | 1995-11-01 | Preliminary foamed particle of polypropylene-based resin and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09124830A true JPH09124830A (en) | 1997-05-13 |
Family
ID=17683110
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7284794A Pending JPH09124830A (en) | 1995-11-01 | 1995-11-01 | Preliminary foamed particle of polypropylene-based resin and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09124830A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007063561A (en) * | 2005-08-31 | 2007-03-15 | Chi Lin Technology Co Ltd | Method of making foamed polymer bead |
-
1995
- 1995-11-01 JP JP7284794A patent/JPH09124830A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007063561A (en) * | 2005-08-31 | 2007-03-15 | Chi Lin Technology Co Ltd | Method of making foamed polymer bead |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2106180C (en) | Process for the preparation of foamed propylene polymer articles | |
| JP3279382B2 (en) | Non-crosslinked polyethylene resin foam particles and method for producing the same | |
| JP2007100025A (en) | Polylactic acid-based resin expansion molded product | |
| JP4083807B2 (en) | Automotive bumper core | |
| JP2009197046A (en) | Uncrosslinked polyethylene extrusion foamed material | |
| US3947388A (en) | Foamed plastics and process for preparing the same | |
| JPS5876230A (en) | Manufacture of polypropylene resin foamed particle | |
| JPH0417977B2 (en) | ||
| JP2002302567A (en) | Method for continuous production of pre-expanded bead of biodegradable polyester-based resin | |
| EP0575958B1 (en) | Pre-expanded particles of LLDPE | |
| KR100837106B1 (en) | A method for manufacturing of non-crosslinked polypropylene foam sheet | |
| EP1031602B9 (en) | Pre-expanded polypropylene resin beads and process for producing molded object therefrom by in-mold foaming | |
| JPH09124830A (en) | Preliminary foamed particle of polypropylene-based resin and its production | |
| CN114605694A (en) | Enhanced polybutylene foam material and preparation method thereof | |
| JP3583543B2 (en) | Polypropylene resin foam particles | |
| JPH0347297B2 (en) | ||
| KR20110085443A (en) | High fuse-bondable polypropylene composition for expanded polypropylene | |
| JP2505543B2 (en) | Method for producing foam containing crystalline propylene resin | |
| JP2709395B2 (en) | Non-crosslinked linear low-density polyethylene resin particles for foaming and method for producing non-crosslinked linear low-density polyethylene expanded particles | |
| JP3537001B2 (en) | Expanded polypropylene resin particles and method for producing the same | |
| KR20180133607A (en) | Ethylene vinyl acetate foam particle with excellent impact resistance and method for producing the same | |
| EP4079797A1 (en) | Multilayer expanded beads and molded article thereof | |
| JPS597025A (en) | Manufacture of polypropylene type resin foamed and molded item | |
| JPS61113627A (en) | Foamed particle of high-density polyethylene resin and production thereof | |
| KR101372137B1 (en) | Polypropylene Resin Composition for Expandable Bead |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040616 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040625 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |