JP2002069225A - Process for producing prefoamed polyolefin resin particle - Google Patents
Process for producing prefoamed polyolefin resin particleInfo
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- JP2002069225A JP2002069225A JP2000253947A JP2000253947A JP2002069225A JP 2002069225 A JP2002069225 A JP 2002069225A JP 2000253947 A JP2000253947 A JP 2000253947A JP 2000253947 A JP2000253947 A JP 2000253947A JP 2002069225 A JP2002069225 A JP 2002069225A
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- polyolefin
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ポリオレフィン系
樹脂組成物予備発泡粒子およびその製造方法に関する。
さらに詳細には、発泡倍率２〜１０倍程度、好ましくは
極低倍領域たとえば３〜８倍の型内発泡成形品の原料と
して好適に使用しうるポリオレフィン系樹脂組成物予備
発泡粒子およびその製造方法に関する技術分野に属す
る。The present invention relates to a pre-expanded polyolefin resin composition particle and a method for producing the same.
More specifically, a pre-expanded polyolefin resin composition particle which can be suitably used as a raw material for an in-mold foam molded article having an expansion ratio of about 2 to 10 times, preferably an extremely low area, for example, 3 to 8 times, and a method for producing the same. Belongs to the technical field.
【０００２】[0002]
【従来の技術および発明が解決しようとする課題】従来
から、密閉容器内でポリオレフィン系樹脂粒子を水系分
散媒に分散させ、揮発性発泡剤を含有させたのちに、前
記ポリオレフィン系樹脂組成物の軟化温度以上に加熱し
たのち、低圧の雰囲気に放出して、ポリオレフィン系樹
脂組成物予備発泡粒子をえる方法はよく知られている
（例えば、特開昭５８−１９９１２５号公報など）。し
かしながら該方法で予備発泡粒子を製造する場合、揮発
性発泡剤を使用することから、コスト高になるだけでな
く、揮発性発泡剤の含浸ムラが大きいことから発泡倍率
のコントロールが困難であると共に、発泡粒子の倍率が
均一でなく、良好な特性の予備発泡粒子をえることがで
きない。また揮発性発泡剤がプロパン、ブタンなどの可
燃性ガスの場合には、燃焼、爆発などの安全性に問題が
ある。2. Description of the Related Art Conventionally, polyolefin resin particles are dispersed in an aqueous dispersion medium in a closed container and a volatile foaming agent is contained therein. A method of obtaining pre-expanded particles of a polyolefin-based resin composition after heating to a softening temperature or higher and then releasing the mixture into a low-pressure atmosphere is well known (for example, JP-A-58-199125). However, when the pre-expanded particles are produced by the method, the use of the volatile foaming agent not only increases the cost but also makes it difficult to control the expansion ratio due to the large impregnation unevenness of the volatile foaming agent. In addition, the magnification of the expanded particles is not uniform, and pre-expanded particles having good characteristics cannot be obtained. When the volatile foaming agent is a flammable gas such as propane or butane, there is a problem in safety such as combustion and explosion.
【０００３】また特開昭６０−２２９９３６号公報に
は、ポリオレフィン系樹脂粒子に窒素含有無機ガスを発
泡剤として含有させたものを低圧の雰囲気に放出して予
備発泡粒子を製造することが記載されている。該方法で
は、揮発性発泡剤を使用することによるコスト高、安全
性の問題はなくなるが、放出される雰囲気の温度ムラに
よって、倍率バラツキが生じ均一に粒度がそろった予備
発泡粒子は得られない。Japanese Unexamined Patent Publication No. 60-229936 discloses a method of producing pre-expanded particles by discharging polyolefin resin particles containing a nitrogen-containing inorganic gas as a blowing agent into a low-pressure atmosphere. ing. In this method, the use of a volatile foaming agent eliminates the cost and safety problems, but pre-expanded particles having a uniform particle size cannot be obtained due to variation in magnification due to uneven temperature of the atmosphere to be released. .
【０００４】また特開昭６０−２２１４４０号公報に
は、エチレン含量１〜１２重量％のエチレン−プロピレ
ン系ランダム共重合体樹脂粒子を水に分散させ、ついで
無機ガスを導入したのちに、加熱し、流出速度２００〜
５００ｍ／秒で低圧の雰囲気に放出することで予備発泡
粒子を製造することが記載されている。しかし該方法で
は、低圧の雰囲気に放出する際の流出速度が大きすぎる
ことから、発泡時の流出速度を一定に保持することが困
難であり、えられる予備発泡粒子の倍率バラツキが悪化
する。Japanese Patent Application Laid-Open No. Sho 60-221440 discloses that ethylene-propylene random copolymer resin particles having an ethylene content of 1 to 12% by weight are dispersed in water, an inorganic gas is introduced, and then heating is performed. , Outflow speed 200 ~
It describes the production of pre-expanded particles by discharging into a low pressure atmosphere at 500 m / sec. However, in this method, it is difficult to keep the outflow speed at the time of foaming constant because the outflow speed at the time of release into the low-pressure atmosphere is too high, and the variation in magnification of the obtained pre-expanded particles is deteriorated.
【０００５】また特開平１１−１０６５４６号広報に
は、ポリオレフィン系樹脂１００重量部及び親水性ポリ
マー０．０５〜２０重量部を含有するポリオレフィン系
樹脂を加熱し含水粒子とした後に、低圧の雰囲気中に放
出する際に、放出された粒子を６０℃以上の気体に接触
させることで予備発泡粒子を製造することが記載されて
いる。しかし該方法では、樹脂中の親水性ポリマーの不
良分散により、えられる予備発泡粒子の倍率バラツキが
悪化する。Japanese Patent Application Laid-Open No. H11-106546 discloses that a polyolefin resin containing 100 parts by weight of a polyolefin resin and 0.05 to 20 parts by weight of a hydrophilic polymer is heated to form water-containing particles, and then heated in a low-pressure atmosphere. It describes that the pre-expanded particles are produced by bringing the released particles into contact with a gas at 60 ° C. or higher when the particles are released into the air. However, in this method, the uneven dispersion of the obtained pre-expanded particles is deteriorated due to poor dispersion of the hydrophilic polymer in the resin.
【０００６】[0006]
【課題を解決するための手段】そこで、本発明者らは、
前記従来技術に鑑み、ポリオレフィン系樹脂の予備発泡
粒子を製造する際に、揮発性発泡剤を使用せずに、か
つ、倍率バラツキの少ない粒度のそろったポリオレフィ
ン系樹脂の予備発泡粒子の製造方法について、鋭意検討
を重ねた結果、密閉容器内の内圧より低圧の雰囲気に放
出させる際に、粒子を飽和水蒸気に接触させる方法によ
って、得られた予備発泡粒子は、飽和水蒸気に接触させ
ない場合と比較して、発泡倍率が向上し、倍率バラツキ
の少ない粒度のそろった予備発泡粒子が得られることを
見出し、本発明を完成するに至った。Accordingly, the present inventors have
In view of the prior art, when manufacturing pre-expanded particles of a polyolefin-based resin, without using a volatile foaming agent, and about a method for producing pre-expanded particles of a polyolefin-based resin having a uniform particle size with small variation in magnification As a result of intensive studies, when the particles are released into an atmosphere at a pressure lower than the internal pressure in the closed container, the method of contacting the particles with saturated steam makes the obtained pre-expanded particles smaller than those without contact with saturated steam. As a result, it was found that the expansion ratio was improved, and that pre-expanded particles having a uniform particle size with less variation in magnification were obtained, and the present invention was completed.
【０００７】すなわち、本発明は、ポリオレフィン系樹
脂粒子を密閉容器内で水系分散媒に分散させ、前記粒子
を前記ポリオレフィン系樹脂の軟化温度以上の温度に加
熱し、密閉容器内の内圧よりも低圧に雰囲気中に放出す
ることによって予備発泡させる際に、放出された粒子を
飽和水蒸気に接触させることを特徴とするポリオレフィ
ン系樹脂予備発泡粒子の製造方法（請求項１）、密閉容
器内の内圧を、窒素、空気またはこれらを主体とする無
機ガスを導入することにより高めたのち、内圧よりも低
圧の雰囲気中に放出することによって発泡させる請求項
１記載のポリオレフィン系樹脂予備発泡粒子の製造方法
（請求項２）、前記ポリオレフィン系樹脂がポリプロピ
レン系樹脂である請求項１乃至２記載のポリオレフィン
系樹脂組成物予備発泡粒子の製造方法（請求項３）、飽
和水蒸気の温度は、前記ポリオレフィン系樹脂の軟化温
度以上、融点以下であることを特徴とする請求項１乃至
３記載のポリオレフィン系樹脂予備発泡粒子の製造方法
（請求項４）、に関する。That is, according to the present invention, polyolefin resin particles are dispersed in an aqueous dispersion medium in a closed container, and the particles are heated to a temperature equal to or higher than the softening temperature of the polyolefin resin, so that the pressure is lower than the internal pressure in the closed container. A method for producing polyolefin-based resin pre-expanded particles, wherein the pre-expanded particles are brought into contact with saturated steam when pre-expanded by releasing them into the atmosphere. 2. The method for producing polyolefin resin pre-expanded particles according to claim 1, wherein the pressure is increased by introducing nitrogen, air, or an inorganic gas mainly composed of these, and then expanded by discharging into an atmosphere at a pressure lower than the internal pressure. (2) The polyolefin resin composition according to any one of (1) to (2), wherein the polyolefin resin is a polypropylene resin. The method for producing foamed polyolefin resin particles according to any one of claims 1 to 3, wherein the temperature of the saturated steam is not lower than the softening temperature and not higher than the melting point of the polyolefin resin. A method (claim 4).
【０００８】[0008]
【発明の実施の形態】本発明においては、ポリオレフィ
ン系樹脂粒子が予備発泡粒子の製造のために使用され
る。DETAILED DESCRIPTION OF THE INVENTION In the present invention, polyolefin resin particles are used for producing pre-expanded particles.
【０００９】前記ポリオレフィン系樹脂は、オレフィン
単量体単位を５０〜１００重量％、さらには７０〜１０
０重量％含有し、オレフィン単量体と共重合可能な単量
体単位を０〜５０重量％、さらには０〜３０重量％含有
する樹脂である。オレフィン単量体単位を５０重量％以
上含有するため、軽量で機械的強度、加工性、電気絶縁
性、耐水性、耐薬品性にすぐれた成形体がえられる。オ
レフィン単量体と共重合可能な単量体単位は、接着性、
透明性、耐衝撃性、ガスバリア性などの改質のために使
用される成分であり、使用することによる効果をえるた
めには、２重量％以上、さらには５重量％以上使用する
のが好ましい。The polyolefin resin contains 50 to 100% by weight of an olefin monomer unit, and more preferably 70 to 10% by weight.
The resin contains 0% by weight, and 0 to 50% by weight, and more preferably 0 to 30% by weight of a monomer unit copolymerizable with the olefin monomer. Since the olefin monomer unit is contained in an amount of 50% by weight or more, a molded article that is lightweight and has excellent mechanical strength, workability, electrical insulation, water resistance, and chemical resistance can be obtained. The monomer unit copolymerizable with the olefin monomer has adhesiveness,
It is a component used for modifying transparency, impact resistance, gas barrier properties, and the like. In order to obtain the effect of use, it is preferably used in an amount of 2% by weight or more, more preferably 5% by weight or more. .
【００１０】前記オレフィン単量体の具体例としては、
エチレン、プロピレン、ブテン、ペンテン、ヘキセン、
ヘプテン、オクテンなどの炭素数２〜８のα−オレフイ
ン単量体やノルボルネン系モノマーなどの環状オレフィ
ンなどがあげられる。これらは単独で用いてもよく、２
種以上を併用してもよい。これらのうちではエチレン、
プロピレンが安価であり、えられる重合体の物性が良好
になる点から好ましい。Specific examples of the olefin monomer include:
Ethylene, propylene, butene, pentene, hexene,
C2-C8 alpha-olefin monomers, such as heptene and octene, and cyclic olefins, such as a norbornene monomer, are mentioned. These may be used alone,
More than one species may be used in combination. Of these, ethylene,
Propylene is preferred because it is inexpensive and the properties of the resulting polymer are improved.
【００１１】前記オレフィン単量体と共重合可能な単量
体の具体例としては、酢酸ビニルなどのビニルアルコー
ルエステル、メチルメタクリレート、エチルアクリレー
ト、ヘキシルアクリレートなどのアルキル基の炭素数が
１〜６の（メタ）アクリル酸アルキルエステル、ビニル
アルコール、メタクリル酸、塩化ビニルなどがあげられ
る。これらは単独で用いてもよく、２種以上を併用して
もよい。これらのうちでは、酢酸ビニルが接着性、柔軟
性、低温特性の点から好ましく、メチルメタクリレート
が接着性、柔軟性、低温特性、熱安定性の点から好まし
い。Specific examples of the monomer copolymerizable with the olefin monomer include vinyl alcohol esters such as vinyl acetate, and alkyl groups having 1 to 6 carbon atoms such as methyl methacrylate, ethyl acrylate and hexyl acrylate. Examples thereof include (meth) acrylic acid alkyl esters, vinyl alcohol, methacrylic acid, and vinyl chloride. These may be used alone or in combination of two or more. Among these, vinyl acetate is preferred from the viewpoint of adhesiveness, flexibility and low-temperature characteristics, and methyl methacrylate is preferred from the viewpoint of adhesiveness, flexibility, low-temperature characteristics and thermal stability.
【００１２】前記ポリオレフィン系樹脂のメルトインデ
ックス（ＭＩ）としては、たとえばポリプロピレン系樹
脂では０．２〜５０ｇ／１０分、さらには１〜３０ｇ／
１０分のものが好ましく、また曲げ弾性率（ＪＩＳ Ｋ
７２０３）としては、たとえばポリプロピレン系樹脂
では５０００〜２００００ｋｇ／ｃｍ2Ｇ、さらには８
０００〜１６０００ｋｇ／ｃｍ2Ｇ、融点としては、た
とえばポリプロピレン系樹脂では１２５〜１６５℃、さ
らには１３０〜１６０℃のものが好ましい。The melt index (MI) of the polyolefin resin is, for example, 0.2 to 50 g / 10 min for a polypropylene resin, and more preferably 1 to 30 g / min.
10 minutes is preferable, and the flexural modulus (JIS K
7203) is, for example, 5,000 to 20,000 kg / cm 2 G for a polypropylene resin,
000~16000kg / cm 2 G, as the melting point, for example, one hundred twenty-five to one hundred sixty-five ° C. in polypropylene resin, more preferably from 130 to 160 ° C..
【００１３】前記ＭＩが０．２ｇ／１０分未満の場合、
溶融粘度が高すぎて高発泡倍率の予備発泡粒子がえられ
にくく、５０ｇ／１０分をこえる場合、発泡時の樹脂の
伸びに対する溶融粘度が低く破泡しやすくなり、高発泡
倍率の予備発泡粒子がえられにくくなる傾向にある。ま
た、前記曲げ強度が５０００ｋｇ／ｃｍ2Ｇ未満の場
合、機械的強度、耐熱性が不十分となり、２００００ｋ
ｇ／ｃｍ2Ｇをこえる場合、えられる発泡成形体の柔軟
性、緩衝特性が不十分となる傾向にある。さらに、融点
が１２５℃未満の場合、耐熱性が不足し、１６５℃をこ
える場合、成形時の融着性、二次発泡力不足となる傾向
にある。When the MI is less than 0.2 g / 10 minutes,
If the melt viscosity is too high, pre-expanded particles with a high expansion ratio are difficult to obtain, and if it exceeds 50 g / 10 minutes, the melt viscosity with respect to the elongation of the resin at the time of expansion is low and the foam tends to break, and the pre-expanded particles with a high expansion ratio Tends to be difficult to obtain. If the bending strength is less than 5000 kg / cm 2 G, the mechanical strength and heat resistance become insufficient, and
When it exceeds g / cm 2 G, the flexibility and cushioning properties of the obtained foamed molded article tend to be insufficient. Further, when the melting point is less than 125 ° C., the heat resistance is insufficient, and when it exceeds 165 ° C., the adhesiveness at the time of molding and the secondary foaming power tend to be insufficient.
【００１４】前記ポリオレフィン系樹脂の具体例として
は、たとえばエチレン−プロピレンランダム共重合体、
エチレン−プロピレン−ブテンランダム３元共重合体、
ポリエチレン−ポリプロピレンブロツク共重合体、ホモ
ポリプロピレンなどのポリプロピレン系樹脂；低密度ポ
リエチレン、中密度ポリエチレン、高密度ポリエチレ
ン、直鎖状低密度ポリエチレン、エチレン−酢酸ビニル
共重合体、エチレン−メチルメタクリレート共重合体な
どのポリエチレン系樹脂；ポリブテン、ポリペンテンな
どがあげられる。前記ポリオレフィン系樹脂は、無架橋
の状態で用いてもよく、パーオキサイドや放射線などに
より架橋させて用いてもよい。これらのポリマーは単独
で用いてもよく、２種以上を併用してもよい。これらの
うちでは、他のポリオレフィン系樹脂と比べて、倍率バ
ラツキが小さく、得られた予備発泡粒子から製造された
成形体の機械的強度や耐熱性が良好であるポリプロピレ
ン系樹脂が好ましい。Specific examples of the polyolefin resin include, for example, an ethylene-propylene random copolymer,
Ethylene-propylene-butene random terpolymer,
Polypropylene resins such as polyethylene-polypropylene block copolymer and homopolypropylene; low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer And polyethylene-based resins; polybutene, polypentene and the like. The polyolefin-based resin may be used in a non-crosslinked state, or may be used after being crosslinked by peroxide or radiation. These polymers may be used alone or in combination of two or more. Among them, a polypropylene-based resin is preferable, in which the variation in magnification is smaller than that of other polyolefin-based resins, and the molded article produced from the obtained pre-expanded particles has good mechanical strength and heat resistance.
【００１５】本発明で用いられるポリオレフィン系樹脂
には、充填剤、すなわち無機充填剤および（または）有
機充填剤を含有せしめるのが、気泡が均一の予備発泡粒
子をえることができるという点から好ましい。The polyolefin resin used in the present invention preferably contains a filler, that is, an inorganic filler and / or an organic filler, from the viewpoint that pre-expanded particles having uniform cells can be obtained. .
【００１６】前記無機充填剤の具体例としては、たとえ
ばタルク、炭酸カルシウム、水酸化カルシウムなどがあ
げられる。これらの無機充填剤のなかでは、タルクが、
倍率バラツキが小さく、気泡が均一で、比較的高発泡倍
率の予備発泡粒子を与える点から好ましい。Specific examples of the inorganic filler include talc, calcium carbonate, calcium hydroxide and the like. Among these inorganic fillers, talc is
This is preferable because pre-expanded particles having a small variation in magnification, uniform cells, and a relatively high expansion ratio are provided.
【００１７】前記有機充填剤としては、前記ポリオレフ
ィン系樹脂の軟化温度以上の温度で固体状のものであれ
ばよく、とくに限定はない。前記有機充填剤の具体例と
しては、たとえばフッ素樹脂粉末、シリコーン樹脂粉
末、熱可塑性ポリエステル樹脂粉末などがあげられる。The organic filler is not particularly limited as long as it is solid at a temperature equal to or higher than the softening temperature of the polyolefin resin. Specific examples of the organic filler include a fluororesin powder, a silicone resin powder, and a thermoplastic polyester resin powder.
【００１８】前記充填剤は、単独で用いてもよく、２種
以上を併用してもよい。The fillers may be used alone or in combination of two or more.
【００１９】前記充填剤の平均粒子径は、気泡が均一で
ある予備発泡粒子をえることができ、また、該予備発泡
粒子から機械的強度や柔軟性などにすぐれた成形体をえ
ることができる点から、５０μｍ以下、さらには１０μ
ｍ以下であるのが好ましく、２次凝集や取扱作業性の点
から０．１μｍ以上、さらには０．５μｍ以上であるの
が好ましい。With respect to the average particle diameter of the filler, pre-expanded particles having uniform cells can be obtained, and a molded article having excellent mechanical strength and flexibility can be obtained from the pre-expanded particles. From the point, 50μm or less, further 10μ
m, preferably 0.1 μm or more, more preferably 0.5 μm or more from the viewpoint of secondary aggregation and handling workability.
【００２０】前記充填剤の使用量は、比較的高発泡倍率
の予備発泡粒子をうる点から、ポリオレフィン系樹脂１
００重量部に対して０．００１重量部以上、さらには
０．００５重量部以上にするのが好ましく、また予備発
泡粒子を成形する際に、すぐれた融着性を発現させ、該
予備発泡粒子から機械的強度や柔軟性などにすぐれた成
形体をえる点から、３重量部以下、好ましくは２重量部
以下である。The amount of the filler to be used is such that polyolefin-based resin 1
The amount is preferably 0.001 part by weight or more, more preferably 0.005 part by weight or more, based on 00 parts by weight. Also, when forming the pre-expanded particles, the pre-expanded particles exhibit excellent fusibility. In order to obtain a molded article having excellent mechanical strength and flexibility, the amount is 3 parts by weight or less, preferably 2 parts by weight or less.
【００２１】前記ポリオレフィン系樹脂に必要により充
填剤などを含有する前記ポリオレフィン系樹脂組成物
は、通常、押出機、ニーダー、バンバリーミキサー、ロ
ールなどを用いて溶融混練する。ついで円柱状、楕円柱
状、球状、立方体状、直方体状など予備発泡に利用しや
すい所望の樹脂粒子形状にするのが好ましい。前記樹脂
粒子を製造する際の条件、樹脂粒子の大きさなどにもと
くに限定はないが、たとえば押出機中で溶融混練してえ
られる樹脂粒子は、通常０．５〜１０ｍｇ／粒である。The polyolefin resin composition containing a filler and the like as necessary in the polyolefin resin is usually melt-kneaded using an extruder, kneader, Banbury mixer, roll, or the like. Next, it is preferable to form a desired resin particle shape such as a columnar shape, an elliptical columnar shape, a spherical shape, a cubic shape, and a rectangular parallelepiped shape which can be easily used for preliminary foaming. The conditions for producing the resin particles, the size of the resin particles, and the like are not particularly limited. For example, the resin particles obtained by melt-kneading in an extruder are usually 0.5 to 10 mg / particle.
【００２２】本発明においては、前記ポリオレフィン系
樹脂粒子を密閉容器内で水系分散媒に分散させ、前記樹
脂粒子を前記ポリオレフィン系樹脂の軟化温度以上の温
度に加熱し、好ましくは、無機ガスを密閉容器内に導入
して、密閉容器内の圧力を０．６〜７．５ＭＰａに保持
した後、密閉容器内の内圧よりも低圧に雰囲気中に放出
することによって発泡させる際に、放出された粒子を飽
和水蒸気に接触させることによって、ポリオレフィン系
樹脂予備発泡粒子が製造される。In the present invention, the polyolefin-based resin particles are dispersed in an aqueous dispersion medium in a closed container, and the resin particles are heated to a temperature equal to or higher than the softening temperature of the polyolefin-based resin. When introduced into a container, the pressure in the closed container is maintained at 0.6 to 7.5 MPa, and then the particles are released at the time of foaming by releasing into the atmosphere at a lower pressure than the internal pressure in the closed container. Is contacted with saturated steam to produce polyolefin-based resin pre-expanded particles.
【００２３】樹脂粒子を分散させる水系分散媒は、前記
ポリオレフィン系樹脂を溶解させない溶媒であればよ
く、通常水または水とエチレングリコール、グリセリ
ン、メタノール、エタノール、イソプロピルアルコール
などのうちの１種以上との混合物が例示されるが、環境
面、経済性などから水が好ましい。The aqueous dispersion medium in which the resin particles are dispersed may be any solvent which does not dissolve the polyolefin resin, and is usually water or water and one or more of ethylene glycol, glycerin, methanol, ethanol, isopropyl alcohol and the like. Is exemplified, but water is preferable in terms of environment, economy and the like.
【００２４】前記密閉容器内で樹脂粒子を水系分散媒に
分散させる際に、無機分散剤として、例えば、第三リン
酸カルシウム、塩基性炭酸マグネシウム、塩基性炭酸亜
鉛、炭酸カルシウムなどの無機塩やベントナイト、カオ
リンなどの粘土類があげられる。これらのうちで第三リ
ン酸カルシウムが、分散力が強く好ましい。When the resin particles are dispersed in the aqueous dispersion medium in the closed container, inorganic dispersants such as inorganic salts such as tribasic calcium phosphate, basic magnesium carbonate, basic zinc carbonate and calcium carbonate, bentonite, etc. Clays such as kaolin; Of these, tribasic calcium phosphate is preferred because of its strong dispersing power.
【００２５】又、界面活性剤としては、たとえばドデシ
ルベンゼンスルホン酸ソーダ、n−パラフィンスルホン
酸ソーダ、α−オレフィンスルホン酸ソーダ、アルキル
ナフタレンスルホン酸ソーダなどのアニオン性界面活性
剤、塩化ベンザルコニウム、塩化アルキルトリメチルア
ンモニウム、塩化ジアルキルジメチルアンモニウムなど
のカチオン性界面活性剤があげられる。これらのうちで
n−パラフィンスルホン酸ソーダが良好な分散力を与
え、生分解されやすいことから好ましい。Examples of the surfactant include anionic surfactants such as sodium dodecylbenzenesulfonic acid, sodium n-paraffinsulfonic acid, sodium α-olefinsulfonic acid, and sodium alkylnaphthalenesulfonic acid, benzalkonium chloride, and the like. And cationic surfactants such as alkyltrimethylammonium chloride and dialkyldimethylammonium chloride. Of these
Sodium n-paraffin sulfonate is preferred because it gives good dispersing power and is easily biodegradable.
【００２６】これらの無機分散剤、および界面活性剤の
使用量については、特別な限定はなく、一般に使用され
る量を使用すればよいが、無機分散剤は、樹脂粒子１０
０重量部に対して０．０５〜１０重量部が好ましく、界
面活性剤は、樹脂粒子１００重量部に対して０．０００
５〜１重量部が好ましい。There are no particular restrictions on the amounts of these inorganic dispersants and surfactants used, and any commonly used amounts may be used.
The amount is preferably 0.05 to 10 parts by weight based on 0 parts by weight, and the surfactant is 0.000 parts by weight based on 100 parts by weight of the resin particles.
5 to 1 part by weight is preferred.
【００２７】前記水系分散媒に分散させる樹脂粒子の量
としては、水系分散媒１００重量部に対して樹脂粒子３
〜１００重量部、さらには１０〜５０重量部が好まし
い。樹脂粒子の量が３重量部未満になると生産性が低下
し、経済的でなくなり、１００重量部をこえると加熱中
に容器内で粒子同士が融着する傾向が生じる。The amount of the resin particles to be dispersed in the aqueous dispersion medium is as follows.
-100 parts by weight, more preferably 10-50 parts by weight. When the amount of the resin particles is less than 3 parts by weight, the productivity is reduced and the method is not economical. When the amount is more than 100 parts by weight, particles tend to fuse in the container during heating.
【００２８】前記樹脂粒子、無機分散剤、および界面活
性剤を密閉容器内で水系分散剤に分散させて加熱する温
度は、使用するポリオレフィン系樹脂の軟化温度以上の
温度で、好ましくは、融点＋２０℃以下、更には、融点
＋５℃以上〜融点＋１５℃の温度が好ましい。例えば、
融点１４５℃のエチレン−プロピレン共重合体の場合、
１４５〜１６５℃、さらには１５０〜１６０℃が好まし
く、１４５℃未満では発泡しにくくなり、１６５℃をこ
えると、えられる予備発泡粒子の機械的強度、耐熱性が
充分でなく、容器内で粒子が融着しやすくなる傾向が生
じる。The temperature at which the resin particles, the inorganic dispersant, and the surfactant are dispersed in the aqueous dispersant in a closed container and heated is a temperature equal to or higher than the softening temperature of the polyolefin resin used, and preferably, the melting point +20. C. or lower, more preferably, a temperature of from the melting point + 5.degree. C. to the melting point + 15.degree. For example,
In the case of an ethylene-propylene copolymer having a melting point of 145 ° C,
It is preferably 145 to 165 ° C, more preferably 150 to 160 ° C, and it is difficult to foam at less than 145 ° C. If it exceeds 165 ° C, the mechanical strength and heat resistance of the obtained pre-expanded particles are not sufficient, and the Tends to be easily fused.
【００２９】なお、ポリオレフィン系樹脂の融点は、Ｄ
ＳＣ（示差走査熱量計）によって、４０℃から２２０℃
まで１０℃／分の速度で昇温し、１０℃／分の速度で４
０℃まで冷却した後、再度、１０℃／分の速度で２２０
℃まで昇温したときに現れる融解ピークの頂点の温度で
ある。The melting point of the polyolefin resin is D
According to SC (differential scanning calorimeter), 40 ° C to 220 ° C
Temperature at a rate of 10 ° C./min.
After cooling to 0 ° C., the temperature was reduced to 220 ° C.
It is the temperature at the top of the melting peak that appears when the temperature is raised to ° C.
【００３０】前記無機ガスとしては、チッ素、空気また
はこれらを主体（通常、５０容量％以上、さらには７０
容量％以上）とし、アルゴン、ヘリウム、キセノンなど
の不活性ガスや水蒸気、酸素、水素、オゾンなどを少量
（５０容量％以下、さらには３０容量％以下）含む無機
ガスなどが使用できるが、経済性、生産性、安全性、環
境適合性などの点からチッ素、空気が好ましい。As the inorganic gas, nitrogen, air or these are mainly used (usually 50% by volume or more, more preferably 70% by volume or more).
Volume%), an inert gas such as argon, helium, xenon, or an inorganic gas containing a small amount of water vapor, oxygen, hydrogen, ozone (50% by volume or less, further 30% by volume or less) can be used. Nitrogen and air are preferred from the viewpoints of performance, productivity, safety, and environmental compatibility.
【００３１】前記無機ガスを導入した後の密閉容器内の
圧力は、前述のごとく０．６〜７．５ＭＰａが好まし
く、更に、１．０〜７．０ＭＰａがより好ましい。前記
圧力が０．６ＭＰａ未満の場合、無機ガスを導入するこ
とによる発泡効果が少なくなり、未発泡ビーズが得られ
る傾向になる。７．５ＭＰａを越えると、予備発泡粒子
内の気泡径が微細化し、独立気泡率が低下して成形品の
収縮、形状安定性、機械的強度が損なわれる。無機ガス
の導入時期は、密閉容器の加熱前、加熱途中、加熱後の
いずれでもよい。As described above, the pressure in the closed vessel after the introduction of the inorganic gas is preferably 0.6 to 7.5 MPa, more preferably 1.0 to 7.0 MPa. When the pressure is less than 0.6 MPa, the foaming effect due to the introduction of the inorganic gas is reduced, and unfoamed beads tend to be obtained. If it exceeds 7.5 MPa, the cell diameter in the pre-expanded particles becomes finer, the closed cell ratio decreases, and the shrinkage, shape stability, and mechanical strength of the molded product are impaired. The timing of introducing the inorganic gas may be before, during or after heating of the closed container.
【００３２】前記密閉容器内の内圧より低圧というの
は、密閉容器内の内圧よりも低い圧力であればよく、通
常は大気圧付近の圧力が選ばれる。又、前記雰囲気と
は、放出された樹脂粒子と水の混合物の飛散軌跡を包含
する空間を意味するが、一般的にはパイプやダクト状の
もので外気と遮断した装置内をいう。The pressure lower than the internal pressure in the closed vessel may be a pressure lower than the internal pressure in the closed vessel, and a pressure near the atmospheric pressure is usually selected. The atmosphere refers to a space including the scattered trajectory of the mixture of the released resin particles and water, but generally refers to a pipe or duct-like device that is isolated from the outside air.
【００３３】前記飽和水蒸気は、放出された粒子と接触
させることによって、発泡粒子の収縮を低減・防止さ
せ、かつ、倍率バラツキの少ない粒度の揃った予備発泡
粒子の製造のために使用されるものであり、予備発泡粒
子に用いられる原料樹脂の融点以下、好ましくは９０〜
１１０℃の温度範囲内で調整されることが好ましく、更
には９５〜１０５℃の温度範囲が好ましい。１１０℃を
超えた場合、樹脂のガラス転移温度または融点付近にな
り予備発泡粒子の気泡が破泡したり、粒子同士が融着す
る。９０℃未満の場合、発泡粒子内の水が急激に凝縮し
てしまい、粒子の収縮が大きく、倍率バラツキが大き
い。The saturated steam is used to reduce or prevent shrinkage of the expanded particles by contacting the discharged particles, and to produce pre-expanded particles having a uniform particle size with less variation in magnification. Below the melting point of the raw resin used for the pre-expanded particles, preferably 90 to
The temperature is preferably adjusted within a temperature range of 110 ° C, and more preferably a temperature range of 95 to 105 ° C. When the temperature exceeds 110 ° C., the glass transition temperature or the melting point of the resin is reached and the bubbles of the pre-expanded particles are broken or the particles are fused to each other. If the temperature is lower than 90 ° C., water in the expanded particles is rapidly condensed, and the particles shrink greatly, and the variation in magnification is large.
【００３４】また、前記飽和水蒸気圧力は、予備発泡粒
子の原料樹脂融点以下の飽和水蒸気圧、好ましくは７０
〜１５０ｋＰａとなるように調整されることが好まし
い。予備発泡粒子を飽和水蒸気と接触させる際には、放
出口直後に、飽和水蒸気吹き込み用口を数箇所設置し、
放出される予備発泡粒子に、飽和水蒸気が各粒子に、均
一に接触する方法が好ましい。飽和水蒸気が均一に接触
することによって、各粒子の倍率バラツキが小さくな
る。The saturated steam pressure is preferably a saturated steam pressure equal to or lower than the melting point of the raw material resin of the pre-expanded particles,
It is preferable that the pressure be adjusted to 150 kPa. When contacting the pre-expanded particles with saturated steam, immediately after the outlet, several saturated steam blowing ports are installed,
A preferred method is one in which saturated water vapor uniformly contacts the pre-expanded particles to be released. The uniform variation of the saturated water vapor reduces the variation in magnification of each particle.
【００３５】この場合、水蒸気の噴出時に若干の水噴霧
を併用しても差し支えなく、または飽和水蒸気と接触さ
せた後に水を噴霧して予備発泡粒子の冷却速度を調節す
るなどの操作を併用しても差し支えはない。In this case, a small amount of water spray may be used at the time of jetting steam, or an operation of adjusting the cooling rate of the pre-expanded particles by spraying water after contacting with saturated steam may be used. There is no problem.
【００３６】樹脂粒子が密閉容器から低圧領域への放出
する際は、絞り盤を通して放出し、かつ無機ガスなどを
密閉内容器内に導入して容器の内圧をできるだけ一定に
維持することが好ましい。前記絞り盤とは、オリフィス
型、ノズル型、ベンチュリ型、などが使用でき、またこ
れらを組み合わせても使用できる。これら絞り板に設け
られる放出口は、放出される樹脂粒子が詰まらないよう
な大きさであり且つ所定の放出速度を達成するものであ
れば、開口面積や断面形状などは何ら制限されるもので
はない。When the resin particles are discharged from the closed container to the low pressure region, it is preferable that the resin particles be discharged through a throttle plate and that the internal pressure of the container be maintained as constant as possible by introducing an inorganic gas or the like into the closed inner container. As the diaphragm, an orifice type, a nozzle type, a venturi type, and the like can be used, and a combination thereof can also be used. The discharge ports provided in these diaphragm plates are of such a size that the resin particles to be discharged are not clogged, and as long as they achieve a predetermined discharge speed, the opening area and the sectional shape are not limited at all. Absent.
【００３７】このように密閉容器内の圧力をできるだけ
一定に保ち、絞り盤を通して放出することによって、樹
脂粒子の放出速度や放出量を容易に一定に保持でき、従
って飽和水蒸気が各粒子に均一に接触するようになり、
これにより倍率バラツキの少ない均一な予備発泡粒子を
えることができる。As described above, by keeping the pressure in the closed container as constant as possible and discharging the resin through the diaphragm, the release speed and the amount of the resin particles can be easily maintained at a constant level. Come into contact,
This makes it possible to obtain uniform pre-expanded particles with little variation in magnification.
【００３８】本発明の方法による予備発泡粒子は、耐圧
容器中で加熱加圧するなど一定時間処理することによる
空気成含などを行った後、型内発泡成形用金型に充填
し、蒸気加熱成形して金型どおりの発泡成形体を製造し
てもよい。かくしてえられた発泡成形体は、原料となる
予備発泡粒子の倍率バラツキが少ないために、成形体内
の密度バラツキが小さく、寸法収縮率、形状変形が小さ
いので、極めて商品価値の高いものとなる。The pre-expanded particles obtained by the method of the present invention are subjected to a process such as heating and pressurizing in a pressure vessel for a certain period of time to carry out air inclusion and the like. Then, a foamed molded article according to the mold may be manufactured. The foamed molded article thus obtained has a small variation in magnification of the pre-expanded particles used as a raw material, and therefore has a small variation in density within the molded article, a small dimensional shrinkage and a small shape deformation, and therefore has a very high commercial value.
【００３９】[0039]
【実施例】以下に実施例および比較例をあげて、本発明
をさらに詳細に説明するが、本発明は、かかる実施例の
みに限定されるものではない。The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.
【００４０】実施例１〜３ ポリオレフィン系樹脂であるエチレン−プロピレンラン
ダム共重合体（密度０．９０〜０．９１ｇ／ｃｍ3、エ
チレン含有率３重量％、融点１４５℃、ＭＩ＝５．５ｇ
／１０分、曲げ弾性率１００００ｋｇ／ｃｍ2Ｇ）１０
０重量部、タルク（平均粒径７μｍ）０．３重量部を添
加し、５０ｍｍφ単軸押出機に供給し、溶融混練したの
ち、直径１．５ｍｍφの円筒ダイより押出し、水冷後カ
ッターで切断し、円柱状のポリオレフィン系樹脂からの
樹脂粒子（１．８ｍｇ／粒）をえた。えられた粒子の軟
化温度は６３℃、融点は１４５℃、ＪＩＳ Ｋ ７１１
２により測定した密度０．９０〜０．９１ｇ／ｃｍ3で
あった。Examples 1 to 3 Ethylene-propylene random copolymer as a polyolefin resin (density 0.90 to 0.91 g / cm 3 , ethylene content 3% by weight, melting point 145 ° C., MI = 5.5 g)
/ 10 min, flexural modulus 10,000 kg / cm 2 G) 10
0 parts by weight and 0.3 parts by weight of talc (average particle size: 7 μm) are added, and the mixture is supplied to a 50 mmφ single screw extruder, melt-kneaded, extruded from a cylindrical die having a diameter of 1.5 mmφ, and cut with a water-cooled cutter. Then, resin particles (1.8 mg / particle) from a columnar polyolefin resin were obtained. The obtained particles have a softening temperature of 63 ° C., a melting point of 145 ° C., and JIS K 711.
And a density of 0.90~0.91g / cm 3 as measured by 2.
【００４１】得られた樹脂粒子１００重量部、無機分散
剤として第三リン酸カルシウム０．３重量部および界面
活性剤としてｎ−パラフィンスルホン酸ソーダ０．００
５重量部を、水３００重量部を耐圧密閉容器に仕込み、
容器内容物を攪拌しながら、１５３．０℃まで加熱し
た。このときの耐圧容器内の圧力は約０．５ＭＰａであ
った。その後、空気加圧により１０分かけて、容器内の
圧力を表１記載の圧力にし、次いで２０分保持後、密閉
容器下部のバルブを開いて、水分散物（樹脂粒子および
水系分散媒）を開孔部を１個有するオリフィスを通じて
低圧容器に放出した。放出の際、オリフィス通過直後に
水蒸気吹き込み口を設け、蒸気圧約１００ｋＰａの水蒸
気が、放出される水分散物に接触するようにした。この
ときの吹込蒸気温度は、温度記録計で９８．０℃であっ
た。尚、放出の間は加熱空気を密閉容器内に導入し、密
閉容器内の温度、内圧を一定に保持した。100 parts by weight of the obtained resin particles, 0.3 part by weight of tribasic calcium phosphate as an inorganic dispersing agent and 0.00% of sodium n-paraffin sulfonate as a surfactant.
5 parts by weight and 300 parts by weight of water are charged into a pressure-resistant sealed container,
The contents of the vessel were heated to 153.0 ° C. while stirring. At this time, the pressure in the pressure vessel was about 0.5 MPa. Then, the pressure in the container was brought to the pressure shown in Table 1 by applying air pressure for 10 minutes, and after holding for 20 minutes, the valve at the lower part of the closed container was opened, and the aqueous dispersion (resin particles and the aqueous dispersion medium) was removed. It was discharged into a low pressure vessel through an orifice having one opening. At the time of discharge, a water vapor blowing port was provided immediately after passing through the orifice, so that water vapor having a vapor pressure of about 100 kPa was in contact with the water dispersion to be discharged. The blown steam temperature at this time was 98.0 ° C. by a temperature recorder. During the discharge, heated air was introduced into the closed container, and the temperature and the internal pressure in the closed container were kept constant.
【００４２】比較例１〜２ 実施例１と同様の操作を行い、樹脂粒子の放出の際は、
蒸気吹き込みを行わずに、予備発泡粒子を得た。Comparative Examples 1-2 The same operation as in Example 1 was performed.
Pre-expanded particles were obtained without steam blowing.
【００４３】比較例３ エチレン−プロピレンランダム共重合体（密度０．９１
ｇ／ｃｍ3、エチレン含有率３重量％、融点１４５℃、
ＭＩ＝５．５ｇ／１０分、曲げ弾性率１００００ｋｇ／
ｃｍ2Ｇ）１００重量部に対し、吸水性ポリマー（エチ
レン−メタクリル酸共重合体のカルボキシル基をナトリ
ウムイオンで塩にし、分子間を架橋させたアイオノマー
（エチレン単位８５重量％とメタクリル酸単位１５重量
％からなり、メタクリル酸単位の６０重量％が塩を形成
しているもの）０．１重量部及びタルク（平均粒径７μ
ｍ）０．３重量部を添加し、５０ｍｍφ単軸押出機に供
給し、溶融混練したのち、直径１．５ｍｍφの円筒ダイ
より押出し、水冷後カッターで切断し、円柱状のポリオ
レフィン系樹脂からの樹脂粒子（１．８ｍｇ／粒）をえ
た。この樹脂粒子を実施例１と同様の操作を行い、予備
発泡粒子を得た。Comparative Example 3 Ethylene-propylene random copolymer (density 0.91
g / cm 3 , ethylene content 3% by weight, melting point 145 ° C.
MI = 5.5 g / 10 min, flexural modulus 10,000 kg /
to cm 2 G) 100 parts by weight, the water-absorbing polymer (ethylene - the carboxyl groups of the methacrylic acid copolymer salified with sodium ions, ionomers crosslinked between molecules (85% by weight of ethylene units and methacrylic acid units 15 weight % Of which methacrylic acid units form a salt) and 0.1 parts by weight of talc (average particle size of 7 μm).
m) 0.3 parts by weight were added, and the mixture was fed to a 50 mmφ single screw extruder, melt-kneaded, extruded from a cylindrical die having a diameter of 1.5 mmφ, cut with a water-cooled cutter, and cut from a columnar polyolefin resin. Resin particles (1.8 mg / particle) were obtained. The same operation as in Example 1 was performed on the resin particles to obtain pre-expanded particles.
【００４４】比較例４ 吸水性ポリマーの添加量を２重量部した以外は、比較例
３と全く同様の操作を行い、予備発泡粒子を得た。Comparative Example 4 Except that the amount of the water-absorbing polymer added was 2 parts by weight, the same operation as in Comparative Example 3 was performed to obtain pre-expanded particles.
【００４５】これら比較実験の測定法は以下による。The measuring method of these comparative experiments is as follows.
【００４６】（発泡倍率（乾燥倍率））予備発泡粒子３
〜１０ｇ程度をはかりとり、６０℃で６時間以上乾燥し
た後、重量ｗを測定後、水没法にて体積ｖを測定し、予
備発泡粒子の真比重ρb＝ｗ／ｖを求め、原料組成物の
密度ρrとの比により、発泡倍率Ｋ＝ρr／ρbを求め
た。(Expansion ratio (dry ratio)) Pre-expanded particles 3
After weighing about 10 g and drying at 60 ° C. for 6 hours or more, measuring the weight w, measuring the volume v by the submerged method, determining the true specific gravity ρb = w / v of the pre-expanded particles, The expansion ratio K = ρr / ρb was determined from the ratio of the density to the density ρr.
【００４７】（成含倍率）乾燥後の予備発泡粒子を２Ｍ
Ｐａの空気加圧に２時間放置し、予備発泡粒子内の圧力
を大気圧より高くし、予備発泡粒子の収縮を完全に回復
した状態の予備発泡粒子を用いて測定した発泡倍率を示
す。(Material content ratio) The pre-expanded particles after drying were
The expansion ratio measured by using the pre-expanded particles in a state where the pressure inside the pre-expanded particles is left higher than the atmospheric pressure by leaving the pre-expanded particles under the air pressure of Pa for 2 hours, and the contraction of the pre-expanded particles is completely recovered.
【００４８】（倍率バラツキ）倍率バラツキは下記の式
より求めた。 倍率バラツキ（％）＝（σm）／Ｋav×１００ 式中のＫavは、ＪＩＳ Ｚ８８０１標準篩（３．５、
４，５，６，７，８，９，１０メッシュの８種）で篩い
分けしたときの各残発泡粒子の重量分率Ｗi、発泡倍率
Ｋiから、式；Ｋav＝Σ｛Ｋi×Ｗi）で求められる平均
発泡倍率。式中のσmは、ＪＩＳ Ｚ８８０１標準篩
（３．５、４，５，６，７，８，９，１０メッシュの８
種）で篩い分けしたときの各残発泡粒子の重量分率
Ｗi、発泡倍率Ｋiから、式；σm＝√Σ｛Ｗi×（Ｋav−
Ｋi）2｝で求められる倍率の標準偏差。(Variation in Magnification) Variation in magnification was determined by the following equation. K av magnification variation (%) = (σ m) / K av × 100 wherein is, JIS Z8801 standard sieve (3.5,
7, 8, 9, 10 the weight fraction W i of each residue foamed particles upon sieved with a mesh eight), the expansion ratio K i, formula; K av = Σ {K i × Average expansion ratio determined by Wi ). Σ m in the formula is JIS Z8801 standard sieve (3.5, 4, 5, 6, 7, 8, 9, 10 mesh 8).
Weight fraction W i of each residue expanded particles when sieved by species), the expansion ratio K i, wherein; σ m = √Σ {W i × (K av -
Ki ) The standard deviation of the magnification determined in 2 ｝.
【００４９】[0049]
【表１】 [Table 1]
【００５０】表１から明らかなごとく、発泡倍率が低い
ポリオレフィン系樹脂予備発泡粒子をえようとする場
合、水蒸気吹き込みを行わない場合は発泡倍率が低くは
なるものの発泡倍率のバラツキが大きく、一部には未発
泡の予備発泡粒子の混入が認められ、型内発泡成型に供
するには不適当なものであった。As is clear from Table 1, when pre-expanded polyolefin resin particles having a low expansion ratio are to be obtained, when the steam is not blown, the expansion ratio is low but the variation in the expansion ratio is large. Was found to be mixed with unfoamed pre-expanded particles, and was unsuitable for use in in-mold foam molding.
【００５１】またポリオレフィン系樹脂に吸水性ポリマ
ーを添加した場合は、発泡倍率は目的とする範囲の低発
泡倍率であるが、放出時に水蒸気を吹き込んでも倍率バ
ラツキは依然として大きいことが判る。When the water-absorbing polymer is added to the polyolefin-based resin, the expansion ratio is a low expansion ratio within a target range, but it can be seen that the expansion ratio is still large even when steam is blown in at the time of release.
【００５２】即ち本願の目的とする低倍領域たとえば３
〜８倍のポリオレフィン系樹脂予備発泡粒子をえるにあ
たり、実施例の方法によれば倍率バラツキが少ない状態
で目的を達成できることが判る。That is, the low magnification area, for example, 3
In obtaining polyolefin resin pre-expanded particles of up to 8 times, it can be seen that according to the method of the example, the objective can be achieved with little variation in magnification.
【００５３】[0053]
【発明の効果】本発明のポリオレフィン系樹脂予備発泡
粒子の製造方法によれば、樹脂粒子の放出の際に、水蒸
気を接触させることによって、倍率バラツキが少なく、
実用上充分な外観を有する予備発泡粒子が得られる。According to the method for producing pre-expanded polyolefin resin particles of the present invention, when the resin particles are released, the water vapor is brought into contact with the resin to reduce the variation in magnification.
Pre-expanded particles having a practically sufficient appearance can be obtained.
【００５４】特に発泡倍率が低い場合、たとえば型内発
泡成型に適した３〜８倍の予備発泡粒子をえるに際して
は本願発明の効果が顕著であり、良好な型内発泡成型品
をえることができる。Particularly when the expansion ratio is low, for example, in obtaining pre-expanded particles of 3 to 8 times suitable for in-mold foam molding, the effect of the present invention is remarkable, and a good in-mold foam molded product can be obtained. it can.
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Claims (4)
で水系分散媒に分散させ、前記樹脂粒子を前記ポリオレ
フィン系樹脂の軟化温度以上の温度に加熱し、密閉容器
内の内圧よりも低圧の雰囲気中に放出することによって
予備発泡させる際に、放出された粒子を飽和水蒸気に接
触させることを特徴とするポリオレフィン系樹脂予備発
泡粒子の製造方法。1. A method for dispersing polyolefin-based resin particles in an aqueous dispersion medium in a closed container, heating the resin particles to a temperature equal to or higher than the softening temperature of the polyolefin-based resin in an atmosphere at a pressure lower than the internal pressure in the closed container. A method for producing polyolefin-based resin pre-expanded particles, wherein the pre-expanded particles are brought into contact with saturated water vapor when pre-expanded by discharging the particles into the polyolefin resin.
たはこれらを主体とする無機ガスを導入することにより
高めたのち、内圧よりも低圧の雰囲気中に放出すること
によって発泡させる請求項１記載のポリオレフィン系樹
脂予備発泡粒子の製造方法2. The method according to claim 1, wherein the internal pressure in the closed container is increased by introducing nitrogen, air or an inorganic gas mainly composed of nitrogen, air, and then released into an atmosphere having a pressure lower than the internal pressure to cause foaming. For producing pre-expanded polyolefin-based resin particles
レン系樹脂である請求項１乃至２記載のポリオレフィン
系樹脂予備発泡粒子の製造方法。3. The method for producing pre-expanded polyolefin resin particles according to claim 1, wherein the polyolefin resin is a polypropylene resin.
フィン系樹脂の軟化温度以上、融点以下であることを特
徴とする請求項１乃至３記載のポリオレフィン系樹脂予
備発泡粒子の製造方法。4. The method for producing pre-expanded polyolefin resin particles according to claim 1, wherein the temperature of the saturated steam is not lower than the softening temperature of the polyolefin resin and not higher than the melting point.
Priority Applications (4)
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| JP2000253947A JP4863542B2 (en) | 2000-08-24 | 2000-08-24 | Method for producing polyolefin resin pre-expanded particles |
| US09/916,315 US6627668B2 (en) | 2000-08-24 | 2001-07-30 | Process for preparing polyolefin pre-expanded particles |
| EP01117780A EP1182225B9 (en) | 2000-08-24 | 2001-08-01 | Process for preparing polyolefin pre-expanded particles |
| DE60124187T DE60124187T2 (en) | 2000-08-24 | 2001-08-01 | Process for the preparation of pre-expanded particles of polyolefin resin |
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| JP2000253947A JP4863542B2 (en) | 2000-08-24 | 2000-08-24 | Method for producing polyolefin resin pre-expanded particles |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009275198A (en) * | 2008-05-19 | 2009-11-26 | Kaneka Corp | Flame-retardant polyolefin-based resin pre-foamed particle, method of manufacturing the same, and flame-retardant polyolefin-based in-mold foam molding |
| JP2010126681A (en) * | 2008-11-28 | 2010-06-10 | Kaneka Corp | Method for decreasing hardly water-soluble inorganic compound attached on surface of polyolefin-based resin expanded particle |
| WO2019187986A1 (en) * | 2018-03-26 | 2019-10-03 | 株式会社カネカ | Producing method and producing apparatus for polyolefin-based resin foam particles |
| JP2021038282A (en) * | 2019-08-30 | 2021-03-11 | 株式会社カネカ | Foamed particle production device and production method |
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|---|---|---|---|---|
| JPS5968340A (en) * | 1982-10-14 | 1984-04-18 | Asahi Chem Ind Co Ltd | Foaming polypropylene resin composition |
| JPS6343935A (en) * | 1986-08-12 | 1988-02-25 | Kanegafuchi Chem Ind Co Ltd | Production of pre-expanded particle of thermo-plastic resin |
| WO1998031733A1 (en) * | 1997-01-20 | 1998-07-23 | Sekisui Kaseihin Kogyo Kabushikikaisha | Expandable thermoplastic resin beads and molded foam made from the same |
-
2000
- 2000-08-24 JP JP2000253947A patent/JP4863542B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5968340A (en) * | 1982-10-14 | 1984-04-18 | Asahi Chem Ind Co Ltd | Foaming polypropylene resin composition |
| JPS6343935A (en) * | 1986-08-12 | 1988-02-25 | Kanegafuchi Chem Ind Co Ltd | Production of pre-expanded particle of thermo-plastic resin |
| WO1998031733A1 (en) * | 1997-01-20 | 1998-07-23 | Sekisui Kaseihin Kogyo Kabushikikaisha | Expandable thermoplastic resin beads and molded foam made from the same |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009275198A (en) * | 2008-05-19 | 2009-11-26 | Kaneka Corp | Flame-retardant polyolefin-based resin pre-foamed particle, method of manufacturing the same, and flame-retardant polyolefin-based in-mold foam molding |
| JP2010126681A (en) * | 2008-11-28 | 2010-06-10 | Kaneka Corp | Method for decreasing hardly water-soluble inorganic compound attached on surface of polyolefin-based resin expanded particle |
| WO2019187986A1 (en) * | 2018-03-26 | 2019-10-03 | 株式会社カネカ | Producing method and producing apparatus for polyolefin-based resin foam particles |
| JPWO2019187986A1 (en) * | 2018-03-26 | 2021-03-18 | 株式会社カネカ | Method and apparatus for manufacturing polyolefin-based resin foam particles |
| JP7324189B2 (en) | 2018-03-26 | 2023-08-09 | 株式会社カネカ | Method and apparatus for producing expanded polyolefin resin particles |
| JP2021038282A (en) * | 2019-08-30 | 2021-03-11 | 株式会社カネカ | Foamed particle production device and production method |
| JP7373943B2 (en) | 2019-08-30 | 2023-11-06 | 株式会社カネカ | Expanded particle manufacturing device and manufacturing method |
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