JPH09111035A - Styrenic foamable resin granule and its production - Google Patents
Styrenic foamable resin granule and its productionInfo
- Publication number
- JPH09111035A JPH09111035A JP27396295A JP27396295A JPH09111035A JP H09111035 A JPH09111035 A JP H09111035A JP 27396295 A JP27396295 A JP 27396295A JP 27396295 A JP27396295 A JP 27396295A JP H09111035 A JPH09111035 A JP H09111035A
- Authority
- JP
- Japan
- Prior art keywords
- resin particles
- styrenic
- expandable resin
- polymerization
- aqueous medium
- 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.)
- Granted
Links
Landscapes
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、予備発泡させたス
チレン系予備発泡粒子のセル変化が少ない、即ち保管条
件によって影響の受けにくいスチレン系発泡性樹脂粒
子、及び、それを得るための製造方法に関するものであ
り、より詳細には、表面外観が著しく優れ、かつ、機械
的強度の優れた発泡成形体を製造することができるスチ
レン系発泡性樹脂粒子、及び、それを得るための製造方
法に関するものである。本発明で得られた粒子は、魚
箱、通い箱、断熱材、ドレンパン等の構造部材、及び、
包装緩衝材等に用いられる発泡成形体の製造に有用であ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to styrenic expandable resin particles having little cell change in styrenic pre-expanded particles that have been pre-expanded, that is, less susceptible to storage conditions, and a method for producing the same. More specifically, the present invention relates to styrenic expandable resin particles capable of producing a foamed molded product having a remarkably excellent surface appearance and excellent mechanical strength, and a production method for obtaining the same. It is a thing. Particles obtained in the present invention, a fish box, a return box, a heat insulating material, a structural member such as a drain pan, and,
It is useful for the production of foamed moldings used as packaging cushioning materials and the like.
【０００２】[0002]
【従来の技術と発明が解決しようとする課題】スチレン
系予備発泡樹脂粒子は比較的安価で、特殊な方法を用い
ずに低圧の蒸気等で発泡成形ができ、高い緩衝・断熱の
効果が得られる社会的に有用な材料である。しかしなが
ら、そのスチレン系予備発泡樹脂粒子は、保管条件によ
りセルが変化し、セル荒れ（セルが極端に大きくなる現
象）や、セルムラを生じたりして、それを用いて製造し
た発泡成形体の外観や強度を著しく損なうことがある。
それらを改良させるために、特殊な核剤を用いたり、低
温で長期間保管（熟成）させて安定化させる技術が提案
されているが、これら方法によると製造条件等の様々な
条件に制約が生じるため、根本的な解決策ではないのが
現状である。BACKGROUND OF THE INVENTION Styrene-based pre-expanded resin particles are relatively inexpensive and can be foam-molded with low-pressure steam without using a special method, resulting in high cushioning and heat-insulating effects. It is a socially useful material. However, the styrenic pre-expanded resin particles have different cells depending on storage conditions, resulting in cell roughening (a phenomenon in which the cells become extremely large) and cell unevenness, and the appearance of the foamed molded product manufactured using it. And strength may be significantly impaired.
In order to improve them, a technique of using a special nucleating agent or storing (aging) for a long time at low temperature to stabilize is proposed, but these methods impose restrictions on various conditions such as manufacturing conditions. As a result, it is not a fundamental solution.
【０００３】また用途によっては、成形品表面の表面外
観が悪く、粒子と粒子との隙間（いわゆる間隙）がある
ため、水漏れ等の問題を生じたり、融着が悪いために強
度低下を招くといった問題もあり、これを解決する方法
として、スチレン系発泡性樹脂粒子に特定の被覆成分を
被覆させた後、比較的高温で強制的に表面近傍の発泡剤
を逸散させる方法が提案されているものの（特開昭６３
−６９８４４号公報、特開平１−２８９８４１号公報、
特開平１−２８９８４３号公報及び特開平２−７７４３
８号公報参照）、特殊な被覆剤を被覆させる必要があっ
たり、一旦発泡性樹脂粒子に含浸した発泡剤を多量に除
去させる工程が必要であり、工業的に不利であった。In addition, depending on the application, the surface appearance of the molded product is poor, and there are gaps between particles (so-called gaps), which causes problems such as water leakage, and poor fusion causes poor strength. As a method of solving this, a method of coating the styrene-based expandable resin particles with a specific coating component and then forcibly dissipating the foaming agent near the surface at a relatively high temperature has been proposed. Although there are
-69844, JP-A-1-289841,
JP-A-1-289843 and JP-A-2-7743
No. 8), it is necessary to coat with a special coating agent, or a step of removing a large amount of the blowing agent once impregnated in the expandable resin particles is required, which is industrially disadvantageous.
【０００４】[0004]
【課題を解決するための手段】本発明者らは、かかる課
題を解決する為に鋭意研究を重ねた結果、上記した一般
の発泡性樹脂粒子には、ボイド（小孔）が粒子全体に渡
って平均的に２００〜５００個／ｍｍ2 程度存在するも
のであるが、例えばスチレン系発泡性樹脂粒子の重合中
若しくは重合完了後の冷却時に電解質を添加すること等
によって、そのボイドをスチレン系発泡性樹脂粒子の表
面近傍のボイド数を少なくして存在させ、２倍の体積に
発泡させた時の表面スキン層を１０〜１００μｍになる
ようにすれば、著しく表面外観が向上すること、また更
には表面近傍のボイド数を少なくするだけでなく粒子内
部のボイドを従来よりも多目に存在するように制御すれ
ば、セルをより安定化させることができ、それを用いる
と特殊な被覆剤を被覆させなくとも、また少量の発泡剤
の逸散量、即ち、より低い温度や短い時間の熱処理で
も、外観が優れ、表面が美麗で、かつ充分な機械的強度
を有する発泡成形体が得られることを見いだし、本発明
を完成するに至った。As a result of intensive studies to solve the above problems, the present inventors have found that the above general expandable resin particles have voids (small holes) throughout the particles. The average number of the voids is about 200 to 500 / mm 2 , but voids are formed by adding an electrolyte during the polymerization of the styrene-based expandable resin particles or during cooling after the completion of the polymerization. The number of voids in the vicinity of the surface of the conductive resin particles is reduced so that the surface skin layer has a thickness of 10 to 100 μm when foamed to a double volume, and the surface appearance is remarkably improved. Can stabilize the cell more by controlling not only the number of voids near the surface but also the number of voids inside the particles to be higher than before, and by using it, a special coating agent can be used. Cover Even if it is not covered, a small amount of the foaming agent escapes, that is, a heat treatment at a lower temperature for a shorter time gives a foamed molded article having an excellent appearance, a beautiful surface, and sufficient mechanical strength. As a result, they have completed the present invention.
【０００５】即ち、本発明は、スチレン系発泡性樹脂粒
子の中心付近を通る断面での表面から半径方向０．１ｍ
ｍ以内のボイド数が１００個／ｍｍ2 以下であり、か
つ、２倍の体積に発泡させた時の表面スキン層が１０〜
１００μｍであることを特徴とするスチレン系発泡性樹
脂粒子である。更には、スチレン系発泡性樹脂粒子の中
心付近を通る断面での表面から半径方向０．３ｍｍ以内
を除く半径方向内部のボイド数が２５０個／ｍｍ2 以上
であるのが好ましい。That is, according to the present invention, the radial direction is 0.1 m from the surface in the cross section passing through the vicinity of the center of the styrenic expandable resin particles.
The number of voids within m is 100 / mm 2 or less, and the surface skin layer is 10 to 10 when foamed in a double volume.
The styrene-based expandable resin particles are characterized by having a size of 100 μm. Further, it is preferable that the number of voids inside the radial direction is 250 or more / mm 2 except within 0.3 mm in the radial direction from the surface of the cross section passing through the center of the styrenic expandable resin particles.
【０００６】更にまた、スチレン系発泡性樹脂粒子の粒
径が０．３〜３ｍｍであるのが好ましい。また、本発明
は、このようなスチレン系発泡性樹脂粒子を得る方法の
１つとしての、スチレン系単量体を重合開始剤及び懸濁
剤の存在下で水性媒体中で懸濁させ、発泡剤を含有させ
て発泡性樹脂粒子を製造する方法において、前記単量体
の重合転化率が３０％以上の時点で、水性媒体に対する
濃度が、０．０２〜５．０ｍｏｌ／ｌになるような量の
電解質を添加して重合する工程、及び、スチレン系発泡
性樹脂粒子を水性媒体から分離した後、温度Ｔが、次式
の範囲 Ｔｇ−２０℃≦Ｔ≦Ｔｇ＋１０℃ （尚、Ｔｇは重合体のガラス転移温度である。）で発泡
剤を３〜２０重量％逸散させる工程からなることを特徴
とするスチレン系発泡性樹脂粒子の製造方法である。Furthermore, the particle size of the styrenic expandable resin particles is preferably 0.3 to 3 mm. Further, the present invention is one of the methods for obtaining such styrenic expandable resin particles, in which a styrene monomer is suspended in an aqueous medium in the presence of a polymerization initiator and a suspending agent, and foamed. In the method for producing expandable resin particles by containing an agent, the concentration of the monomer in the aqueous medium is 0.02 to 5.0 mol / l when the polymerization conversion rate of the monomer is 30% or more. After the step of adding an amount of electrolyte and polymerizing, and separating the styrenic expandable resin particles from the aqueous medium, the temperature T is in the range of the following formula: Tg-20 ° C ≤ T ≤ Tg + 10 ° C (where Tg is It is the glass transition temperature of the coalescence.) The method comprises the step of allowing the foaming agent to dissipate in an amount of 3 to 20% by weight.
【０００７】更に、電解質は塩化ナトリウム、塩化マグ
ネシウム、塩化カリウム、塩化カルシウム、硫酸ナトリ
ウム、硫酸マグネシウム、硫酸カリウム、炭酸ナトリウ
ム、炭酸カリウム、酢酸ナトリウム、安息香酸ナトリウ
ム、琥珀酸二ナトリウムからなる群から選ばれる少なく
とも１種であるのが好ましい。更にまた、発泡剤を逸散
させる工程における温度は、２５℃〜５５℃であるのが
好ましい。Further, the electrolyte is selected from the group consisting of sodium chloride, magnesium chloride, potassium chloride, calcium chloride, sodium sulfate, magnesium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium acetate, sodium benzoate and disodium succinate. It is preferable that it is at least one kind. Furthermore, the temperature in the step of dissipating the blowing agent is preferably 25 ° C to 55 ° C.
【０００８】ここで、スチレン系発泡性樹脂粒子の製造
方法において、単量体の重合転化率が０〜３０％の間
に、過硫酸のアルカリ金属塩若しくはアンモニウム塩を
水性媒体に対し０．５〜３０ｐｐｍになるような量添加
するのが好ましい。Here, in the method for producing styrenic expandable resin particles, an alkali metal salt or ammonium salt of persulfuric acid is added to an aqueous medium in an amount of 0.5 to 30% while the polymerization conversion rate of the monomer is 0 to 30%. It is preferable to add it in an amount such that it is about 30 ppm.
【０００９】[0009]
【発明の実施の形態】本発明のスチレン系発泡性樹脂粒
子は、その粒子の中心付近を通る断面での表面から半径
方向０．１ｍｍ以内（以下「表面部」と呼ぶことがあ
る）のボイド数が１００個／ｍｍ2 以下、好ましくは０
〜７０個／ｍｍ2 であり、かつ、２倍の体積に発泡させ
た時の表面スキン層が１０〜１００μｍ、好ましくは２
０〜８０μｍである。BEST MODE FOR CARRYING OUT THE INVENTION The styrenic expandable resin particles of the present invention are voids within 0.1 mm (hereinafter sometimes referred to as "surface portion") in the radial direction from the surface in a cross section passing through the center of the particles. The number is 100 / mm 2 or less, preferably 0
˜70 pieces / mm 2 , and the surface skin layer when foamed in a double volume is 10 to 100 μm, preferably 2
It is 0 to 80 μm.
【００１０】表面部のボイド数が多過ぎると、成形品外
観の優れた発泡成形体が得られないし、また、２倍の体
積に発泡させた時の表面スキン層が薄過ぎても、著しく
表面外観が優れた成形体が得られにくい。逆に表面スキ
ン層が厚過ぎても、成形の際の２次発泡力が不充分であ
る為に粒子表面の伸びが悪くなり、優れた表面外観を有
する成形体が得られない場合があり好ましくない。If the number of voids in the surface portion is too large, a foamed molded product having an excellent appearance of the molded product cannot be obtained, and if the surface skin layer when foamed to twice the volume is too thin, the surface is remarkably reduced. It is difficult to obtain a molded product with an excellent appearance. On the other hand, if the surface skin layer is too thick, the secondary foaming power during molding is insufficient and the elongation of the particle surface deteriorates, so that a molded product having an excellent surface appearance may not be obtained, which is preferable. Absent.
【００１１】更には、スチレン系発泡性樹脂粒子の中心
付近を通る断面での表面から半径方向０．３ｍｍ以内を
除く半径方向内部のボイド数が２５０個／ｍｍ2 以上、
好ましくは３５０個／ｍｍ2 以上、更に好ましくは５０
０個／ｍｍ2 以上であって、また１００００個／ｍｍ2
以下であるのが、充分な機械的強度を有する発泡成形体
が得られるので好ましい。Further, the number of voids inside the radial direction excluding within 0.3 mm in the radial direction from the surface of the cross section passing through the center of the styrenic expandable resin particles is 250 / mm 2 or more,
Preferably 350 / mm 2 or more, more preferably 50
0 pieces / mm 2 or more, and 10000 pieces / mm 2
The following is preferable because a foamed molded product having sufficient mechanical strength can be obtained.
【００１２】尚、本発明で言う「ボイド」とは、スチレ
ン系発泡性樹脂粒子中に存在する、直径０．１〜３０μ
ｍ程度の小孔であり、その内部にはポリスチレン以外の
物質、即ち水、発泡剤、溶剤、可塑剤、残存モノマー等
を含んでいても良い。また、ボイド数は、スチレン系発
泡性樹脂粒子の中心付近を通る断面をミクロトームで切
り出し、この断面を走査型電子顕微鏡で観察し、写真を
撮り、この写真よりボイド数を計測し、１ｍｍ2 当たり
の値に換算することによって求められる。また、スチレ
ン系発泡性樹脂粒子を、屈折率を合わせるために屈折率
が約１．５１の屈折率調整剤（例えばツェーデル油、キ
シダ化学社製、１級品、屈折率＝１．５１４〜１．５２
２）に浸した状態で光学顕微鏡（透過光）で観察する方
法によって、ある程度のボイド数をより簡便に求めるこ
とができる。The "voids" referred to in the present invention are present in the styrenic expandable resin particles and have a diameter of 0.1 to 30 μm.
It is a small hole of about m and may contain substances other than polystyrene, such as water, a foaming agent, a solvent, a plasticizer, and a residual monomer. Also, number of voids is cut a section through the vicinity of the center of the styrenic expandable resin particles with a microtome, and observing the cross section with a scanning electron microscope, taking photos, the number of voids is measured from this photograph, 1 mm 2 per It is calculated by converting to the value of. Further, in order to adjust the refractive index of the styrenic expandable resin particles, a refractive index adjusting agent having a refractive index of about 1.51 (for example, Zedel oil, manufactured by Kishida Chemical Co., Ltd., first grade product, refractive index = 1.514 to 1) .52
By a method of observing with an optical microscope (transmitted light) in a state of being immersed in 2), it is possible to more easily obtain a certain number of voids.
【００１３】尚また、本発明で言う「表面スキン層」と
は、スチレン系樹脂粒子を、１００℃の水蒸気で加熱し
て約２倍の体積に発泡させた際に存在する粒子表面部の
発泡していない層であり、スチレン系樹脂粒子を、１０
０℃の水蒸気で加熱して約２倍の体積に発泡させ、この
予備発泡粒子の中心付近を通る断面を切り出し、この断
面を走査型電子顕微鏡で観察し、写真を撮り、表面スキ
ン層（表面部の発泡していない層）の厚みを計測するこ
とにより求められる。The "surface skin layer" referred to in the present invention means that the styrene resin particles are heated with steam at 100 ° C. to foam to a volume about twice that of the surface of the particles. It is a layer which is not formed, and the styrenic resin particles are added to 10
It is heated with water vapor at 0 ° C to expand it to about twice its volume, a cross section passing through the center of the pre-expanded particles is cut out, the cross section is observed with a scanning electron microscope, a photograph is taken, and the surface skin layer (surface It is determined by measuring the thickness of the non-foamed layer).
【００１４】尚、これらスチレン系発泡性樹脂粒子の粒
径は通常０．３〜３ｍｍである。本発明のスチレン系発
泡性樹脂粒子は上記の通りであるが、製造後２４時間以
内の粒子中の内部水分量が少ない方が、その後の発泡剤
を逸散させる工程での発泡剤逸散率が高く、また、比較
的低温若しくは短時間での処理でも充分に発泡剤を逸散
させることができ、外観の優れた成形体が得られるので
好ましい。この内部水分量は好ましくは樹脂粒子中０．
１重量％以下である。The particle size of these styrenic expandable resin particles is usually 0.3 to 3 mm. The styrenic expandable resin particles of the present invention are as described above, but the smaller the amount of internal water in the particles within 24 hours after production, the more the blowing agent escape rate in the subsequent step of releasing the blowing agent. Is high, and the foaming agent can be sufficiently diffused even by treatment at a relatively low temperature or in a short time, and a molded article having an excellent appearance can be obtained, which is preferable. This internal water content is preferably 0.
It is 1% by weight or less.
【００１５】上記した本発明のスチレン系発泡性樹脂粒
子を得る１つの方法としては、スチレン系単量体を重合
開始剤及び懸濁剤の存在下で水性媒体（重合系内に存在
する水全てを言う。以下同様）中に分散させた後に、重
合反応を開始し、重合転化率が３０％以上の時点で、水
性媒体に対する濃度が、０．０２〜５．０ｍｏｌ／ｌに
なるような量の電解質を添加して懸濁重合を行い、懸濁
重合中に発泡剤を添加するか、又は重合後に発泡剤を含
浸させて、例えば粒径０．３〜３ｍｍの大きさのスチレ
ン系発泡性樹脂粒子を得、その後スチレン系発泡性樹脂
粒子を水性媒体から分離し、温度Ｔが、次式の範囲 Ｔｇ−２０℃≦Ｔ≦Ｔｇ＋１０℃ （尚、Ｔｇは重合体のガラス転移温度である。）で発泡
剤を３〜２０重量％逸散させる方法が挙げられる。One method for obtaining the above-mentioned styrenic expandable resin particles of the present invention is to use a styrene-based monomer in the presence of a polymerization initiator and a suspending agent in an aqueous medium (all the water present in the polymerization system). The same shall apply hereinafter), after which the polymerization reaction is started, and the concentration in the aqueous medium becomes 0.02 to 5.0 mol / l at the time when the polymerization conversion rate is 30% or more. Suspension polymerization is carried out by adding the above electrolyte, or a foaming agent is added during suspension polymerization, or a foaming agent is impregnated after the polymerization, for example, a styrene-based foaming property of a particle size of 0.3 to 3 mm. Resin particles are obtained, and then the styrenic expandable resin particles are separated from the aqueous medium, and the temperature T is in the range of the following formula: Tg−20 ° C. ≦ T ≦ Tg + 10 ° C. (where Tg is the glass transition temperature of the polymer). ) In which the blowing agent is dissipated in an amount of 3 to 20% by weight. It is.
【００１６】本発明のスチレン本発明のスチレン系発泡
性樹脂粒子の製造方法において使用されるスチレン系単
量体としては、スチレン、α−メチルスチレン、ｏ−メ
チルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレ
ン、ビニルトルエン、ｐ−エチルスチレン、２，４−ジ
メチルスチレン、ｐ−メトキシスチレン、ｐ−フェニル
スチレン、ｏ−クロロスチレン、ｍ−クロロスチレン、
ｐ−クロロスチレン、２，４−ジクロロスチレン、ｐ−
ｎ−ブチルスチレン、ｐ−ｔ−ブチルスチレン、ｐ−ｎ
−ヘキシルスチレン、ｐ−オクチルスチレン、スチレン
スルホン酸、スチレンスルホン酸ナトリウム等が挙げら
れる。また、アクリル酸メチル、アクリル酸エチル、ア
クリル酸プロピル、アクリル酸ブチル、アクリル酸−２
−エチルヘキシル等のアクリル酸の炭素数１〜１０のア
ルキルエステル；メタクリル酸メチル、メタクリル酸エ
チル、メタクリル酸プロピル、メタクリル酸ブチル、メ
タクリル酸−２−エチルヘキシル等のメタクリル酸の炭
素数１〜１０のアルキルエステル；ヒドロキシエチルア
クリレート、ヒドロキシエチルメタクリレート、ヒドロ
キシプロピルアクリレート、ヒドロキシプロピルメタク
リレート、ヒドロキシブチルアクリレート、ヒドロキシ
ブチルメタクリレート等の水酸基を有する不飽和化合
物；アクリロニトリル、メタクリロニトリル等のニトリ
ル基含有不飽和化合物；酢酸ビニル、プロピオン酸ビニ
ル等の有機酸ビニル化合物；エチレン、プロピレン、１
−ブテン、２−ブテン、イソブテン等の不飽和モノオレ
フィン類；ブタジエン、イソプレン、クロロプレン等の
ジエン化合物；塩化ビニル、塩化ビニリデン、臭化ビニ
ル、フッ化ビニル等のハロゲン化ビニル；ビニルメチル
ケトン、ビニルエチルケトン、ビニルヘキシルケトン等
のビニルケトン類；ビニルメチルエーテル、ビニルエチ
ルエーテル、ビニルイソブチルエーテル等のビニルエー
テル類；Ｎ−ビニルピロリドン、Ｎ−ビニルインドー
ル、Ｎ−ビニルカルバゾール、Ｎ−ビニルピロール等の
Ｎ−ビニル化合物；アクリルアミド、メタクリルアミ
ド、Ｎ−メチロールアクリルアミド、Ｎ−メチロールメ
タクリルアミド等のアミド基を有する不飽和化合物；ア
クリル酸、メタクリル酸、イタコン酸等の不飽和カルボ
ン酸；Ｎ−フェニルマレイミド、Ｎ−（メチル）フェニ
ルマレイミド、Ｎ−（ヒドロキシ）フェニルマレイミ
ド、Ｎ−（メトキシ）フェニルマレイミド、Ｎ−安息香
酸マレイミド、Ｎ−メチルマレイミド、Ｎ−エチルマレ
イミド、Ｎ−ｎ−プロピルマレイミド、Ｎ−イソプロピ
ルマレイミド、Ｎ−ｎ−ブチルマレイミド、Ｎ−イソブ
チルマレイミド、Ｎ−ｔ−ブチルマレイミド等のマレイ
ミド系化合物；ジビニルベンゼン、エチレングリコール
ジメタクリレート等の架橋性多官能ビニル化合物；グリ
シジルアクリレート、グリシジルメタクリレート等のエ
ポキシ基を有する不飽和化合物、などの各種のビニル系
化合物を併用しても良い。Styrene of the present invention: Styrene-based monomers used in the method for producing styrenic expandable resin particles of the present invention include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p- Methylstyrene, vinyltoluene, p-ethylstyrene, 2,4-dimethylstyrene, p-methoxystyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene,
p-chlorostyrene, 2,4-dichlorostyrene, p-
n-butylstyrene, pt-butylstyrene, pn
-Hexyl styrene, p-octyl styrene, styrene sulfonic acid, sodium styrene sulfonate and the like. In addition, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic acid-2
-C1-C10 alkyl ester of acrylic acid such as ethylhexyl; C1-C10 alkyl of methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. Esters; Unsaturated compounds having hydroxyl groups such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate; nitrile group-containing unsaturated compounds such as acrylonitrile and methacrylonitrile; vinyl acetate Vinyl compounds such as vinyl propionate; ethylene, propylene, 1
-Unsaturated monoolefins such as butene, 2-butene and isobutene; diene compounds such as butadiene, isoprene and chloroprene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl methyl ketone, vinyl Vinyl ketones such as ethyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; N- such as N-vinyl pyrrolidone, N-vinyl indole, N-vinyl carbazole and N-vinyl pyrrole. Vinyl compounds; unsaturated compounds having an amide group such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid; N-phenylmer Imide, N- (methyl) phenylmaleimide, N- (hydroxy) phenylmaleimide, N- (methoxy) phenylmaleimide, N-benzoic acid maleimide, N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N Maleimide compounds such as isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide; crosslinkable polyfunctional vinyl compounds such as divinylbenzene, ethylene glycol dimethacrylate; glycidyl acrylate, glycidyl methacrylate, etc. Various vinyl compounds such as unsaturated compounds having an epoxy group may be used in combination.
【００１７】また、本発明のスチレン系発泡性樹脂粒子
の製造方法において使用される重合開始剤としては、た
とえばアゾビスイソブチロニトリル等のアゾ系化合物、
クメンヒドロパーオキサイド、ジクミルパーオキサイ
ド、ｔ−ブチルパーオキシ−２−エチルヘキサノエー
ト、ｔ−ブチルパーオキシベンゾエート、ベンゾイルパ
ーオキサイド、ｔ−ブチルパーオキシイソプロピルカー
ボネート、ｔ−ブチルパーオキシ２−エチルヘキシルモ
ノカーボネート、ジクミルパーオキサイド、ラウロイル
パーオキサイド等の単量体に可溶な開始剤が挙げられ
る。重合開始剤の使用量は、通常、仕込み単量体の全重
量１００重量部に対して０．０１〜３重量部が好まし
い。The polymerization initiator used in the method for producing styrenic expandable resin particles of the present invention includes, for example, azo compounds such as azobisisobutyronitrile,
Cumene hydroperoxide, dicumyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl Examples thereof include initiators soluble in monomers such as monocarbonate, dicumyl peroxide, and lauroyl peroxide. Usually, the amount of the polymerization initiator used is preferably 0.01 to 3 parts by weight based on 100 parts by weight of the total amount of the charged monomers.
【００１８】本発明のスチレン系発泡性樹脂粒子の製造
方法において使用される懸濁剤としては、一般に市販さ
れているものが利用でき、例えばポリビニルアルコー
ル、メチルセルロース、ポリビニルピロリドン等の水溶
性高分子、ピロリン酸マグネシウム、第３燐酸カルシウ
ム等の難溶性無機塩等を用いることができ、これらは界
面活性剤を併用してもよい。なお、難溶性無機塩を用い
る場合は、アルキルスルホン酸ソーダ、ドデシルベンゼ
ンスルホン酸ソーダ等のアニオン性界面活性剤を併用す
るのが好ましい。As the suspending agent used in the method for producing the styrenic expandable resin particles of the present invention, those which are generally commercially available can be used, for example, water-soluble polymers such as polyvinyl alcohol, methyl cellulose and polyvinyl pyrrolidone, A sparingly soluble inorganic salt such as magnesium pyrophosphate or tricalcium phosphate can be used, and a surfactant may be used together therewith. When a sparingly soluble inorganic salt is used, it is preferable to use an anionic surfactant such as sodium alkyl sulfonate or sodium dodecylbenzene sulfonate together.
【００１９】懸濁剤の使用量は、仕込み単量体の全重量
１００重量部に対し０．０１〜５．０重量部が好まし
く、前記した難溶性無機塩とアニオン性界面活性剤との
併用系では、それぞれ仕込み単量体の全重量１００重量
部に対し難溶性無機塩を０．０５〜３．０重量部、アニ
オン性界面活性剤を０．０００１〜０．５重量部が好ま
しい。The amount of the suspending agent used is preferably 0.01 to 5.0 parts by weight with respect to 100 parts by weight of the total amount of the charged monomers, and the sparingly soluble inorganic salt and the anionic surfactant are used in combination. In the system, 0.05 to 3.0 parts by weight of the poorly soluble inorganic salt and 0.0001 to 0.5 parts by weight of the anionic surfactant are preferable with respect to 100 parts by weight of the total amount of the charged monomers.
【００２０】また本発明のスチレン系発泡性樹脂粒子の
製造方法において使用される電解質は、水溶液中でイオ
ン解離する物質であればよく、例えば、塩化リチウム、
塩化ナトリウム、塩化マグネシウム、塩化カリウム、塩
化カルシウム、塩化アンモニウム、硫酸ナトリウム、硫
酸マグネシウム、硫酸カリウム、硫酸アルミニウム、硫
酸アンモニウム、硝酸ナトリウム、硝酸マグネシウム、
硝酸カリウム、硝酸カルシウム、炭酸ナトリウム、炭酸
マグネシウム、炭酸カリウム、炭酸カルシウム、炭酸ア
ンモニウム等の無機塩類、或は酢酸カリウム、酢酸ナト
リウム、オクタン酸ナトリウム、安息香酸ナトリウム、
琥珀酸二ナトリウム等の水に可溶なカルボン酸のアルカ
リ金属塩等が挙げられる。特に塩化ナトリウムは、少量
の添加重量で本発明の表面部の発泡開始点となり得るボ
イドの少ないスチレン系発泡性樹脂粒子を容易に得るこ
とができ、また工業的に安価に大量に入手できるので好
ましい。The electrolyte used in the method for producing styrenic expandable resin particles of the present invention may be any substance that ionically dissociates in an aqueous solution, such as lithium chloride,
Sodium chloride, magnesium chloride, potassium chloride, calcium chloride, ammonium chloride, sodium sulfate, magnesium sulfate, potassium sulfate, aluminum sulfate, ammonium sulfate, sodium nitrate, magnesium nitrate,
Inorganic salts such as potassium nitrate, calcium nitrate, sodium carbonate, magnesium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, or potassium acetate, sodium acetate, sodium octanoate, sodium benzoate,
Examples thereof include water-soluble alkali metal salts of carboxylic acids such as disodium succinate. In particular, sodium chloride is preferable because it is possible to easily obtain styrene-based expandable resin particles with few voids that can be the foaming starting point of the surface portion of the present invention with a small amount of addition weight, and industrially inexpensively available in large quantities. .
【００２１】また、本電解質の添加は、重合転化率が３
０％以上の時点で行うことが肝要である。重合転化率が
３０％未満でのみ添加した場合は、本発明のボイド形態
のスチレン系発泡性樹脂粒子が得られない。又、最終的
に得られる発泡性樹脂粒子の粒子径が粗大化したり、変
形を起こすことがあり、条件によっては重合中の懸濁状
態が不安定になり塊化する場合がある。尚、本電解質の
添加は、好ましくは重合転化率が５０〜１００％、更に
好ましくは７５〜１００％の間で行う。The addition of this electrolyte has a polymerization conversion ratio of 3
It is important to do it at the time of 0% or more. When the polymerization conversion rate is less than 30%, the void-form styrenic expandable resin particles of the present invention cannot be obtained. In addition, the particle diameter of the expandable resin particles finally obtained may become coarse or deform, and depending on the conditions, the suspended state during polymerization may become unstable and agglomerate. The electrolyte is preferably added at a polymerization conversion rate of 50 to 100%, more preferably 75 to 100%.
【００２２】これら電解質は粉体若しくは水溶液として
添加されるが、その添加方法は、重合転化率が３０％以
上の時点であれば、１回若しくは数回に分割してもよ
い。但し、水性媒体のｐＨ調整等の目的で、懸濁状態の
不安定化を生じず、本発明の目的を損なわない範囲で、
上記電解質を重合率が３０％未満の時期に少量添加する
ことは差し支えない。These electrolytes are added as a powder or an aqueous solution, and the addition method may be performed once or several times as long as the polymerization conversion rate is 30% or more. However, for the purpose of adjusting the pH of the aqueous medium or the like, instability of the suspended state does not occur, and the object of the present invention is not impaired,
There is no problem in adding a small amount of the above electrolyte when the polymerization rate is less than 30%.
【００２３】なお、ここでいう重合転化率は、比重液
法、赤外吸光分析法、ガスクロマトグラフィー等の方法
で知ることができる。また、重合率３０％以上の時点で
水性媒体中に添加する電解質の量は、該水性媒体に対
し、０．０２〜５．０ｍｏｌ／ｌ、好ましくは０．０３
〜１．０ｍｏｌ／ｌになる量である。添加量が少な過ぎ
ると、表面部のボイドが多くなりやすく、ひいては得ら
れる成形品の外観が劣ることとなる。逆に添加量が多過
ぎると重合を安定に行うことが困難となり、塊化し易く
なる上、添加量に見合った効果が得られない。The polymerization conversion rate referred to herein can be known by a method such as a specific gravity method, infrared absorption spectrometry, gas chromatography and the like. The amount of the electrolyte added to the aqueous medium at a polymerization rate of 30% or more is 0.02 to 5.0 mol / l, preferably 0.03 with respect to the aqueous medium.
The amount is about 1.0 mol / l. If the addition amount is too small, the voids in the surface portion are likely to increase, and the appearance of the obtained molded product deteriorates. On the other hand, if the addition amount is too large, it becomes difficult to carry out the polymerization stably, and it is easy to agglomerate, and the effect corresponding to the addition amount cannot be obtained.
【００２４】更に、重合転化率が０〜３０％、好ましく
は０〜２０％の間に過硫酸のアルカリ金属塩若しくはア
ンモニウム塩を水性媒体に対し０．５〜３０ｐｐｍ、好
ましくは０．５〜２０ｐｐｍになるような量添加する
と、粒子内のボイド数をより多く存在させることができ
るので好ましい。余り重合が進みすぎた時点で添加して
も粒子内部のボイド数を充分に形成させることが難しく
なるし、またこの添加量が少な過ぎると、粒子内部のボ
イド数を充分に形成させることが難しくなり、逆に添加
量が多過ぎると表面部のボイド数が多くなり過ぎ、成形
品外観の優れた発泡成形体が得られにくくなるので好ま
しくない。尚、重合添加時期が上述の間であれば、２回
以上に分割して添加することは差し支えない。Further, an alkali metal salt or ammonium salt of persulfate is added to the aqueous medium in an amount of 0.5 to 30 ppm, preferably 0.5 to 20 ppm while the polymerization conversion rate is 0 to 30%, preferably 0 to 20%. It is preferable to add such an amount so that more voids can be present in the particles. It will be difficult to form a sufficient number of voids inside the particles even if added at a time when the polymerization is too advanced, and if the amount of addition is too small, it will be difficult to form a sufficient number of voids inside the particles. On the contrary, if the addition amount is too large, the number of voids in the surface portion becomes too large, and it becomes difficult to obtain a foamed molded product having an excellent appearance of the molded product, which is not preferable. In addition, if the polymerization addition time is in the above-mentioned range, the addition may be performed in two or more times.
【００２５】本発明のスチレン系発泡性樹脂粒子の製造
方法において使用される過硫酸のアルカリ金属塩若しく
はアンモニウム塩としては、例えば過硫酸カリウム、過
硫酸ナトリウム、過硫酸アンモニウム等が挙げられる。
本発明のスチレン系発泡性樹脂粒子の製造方法において
は、内部のボイド数を増加させるために、ポリエチレン
ワックス、エチレンビスアミド、ヘキサブロモシクロド
デカン、タルク、及び、メタクリル酸低級アルキルエス
テル単位を５重量％以上含むメタクリル酸低級アルキル
エステル系共重合体からなる群から選ばれる少なくとも
１種以上を、スチレン系単量体に対し０．０００１〜
０．９５重量％水性媒体中に存在させることが好まし
い。Examples of the alkali metal salt or ammonium salt of persulfate used in the method for producing styrenic expandable resin particles of the present invention include potassium persulfate, sodium persulfate, ammonium persulfate and the like.
In the method for producing styrenic expandable resin particles of the present invention, in order to increase the number of internal voids, polyethylene wax, ethylenebisamide, hexabromocyclododecane, talc, and methacrylic acid lower alkyl ester units are contained in an amount of 5% by weight. At least one selected from the group consisting of methacrylic acid lower alkyl ester-based copolymers containing 0.0001 to styrene-based monomer is added.
It is preferably present in a 0.95% by weight aqueous medium.
【００２６】また、更に必要に応じて、その重合反応系
に分子量を調整するために、ドデシルメルカプタン等の
アルキルメルカプタン類、α−メチルスチレンダイマー
等の連鎖移動剤を重合反応系に添加することができる。
その連鎖移動剤の使用量は、重合させる全単量体１００
重量部に対して、０．０１〜３重量部が好ましい。単量
体の水性媒体への添加方法は、予め一括に仕込んでもよ
いし、徐々に添加しながら行っても良い。（特公昭４６
−２９８７号、特公昭４９−２９９４号参照）Further, if necessary, in order to adjust the molecular weight of the polymerization reaction system, alkyl mercaptans such as dodecyl mercaptan and a chain transfer agent such as α-methylstyrene dimer may be added to the polymerization reaction system. it can.
The amount of the chain transfer agent used is 100 for all monomers to be polymerized.
0.01 to 3 parts by weight is preferable with respect to parts by weight. As a method of adding the monomer to the aqueous medium, the monomers may be preliminarily charged all at once or may be added gradually. (Japanese Patent Sho 46
(See No. 2987, Japanese Patent Publication No. 49-2994)
【００２７】また、本発明のスチレン系発泡性樹脂粒子
の製造方法においては、必要に応じて、重合反応系に生
成重合体の可塑剤、たとえばジオクチルフタレート等の
フタル酸エステル、その他脂肪酸エステルやキシレン、
トルエン、シクロヘキサン等の有機化合物等を添加する
ことができる。In the method for producing styrenic expandable resin particles of the present invention, if necessary, a plasticizer of the produced polymer is added to the polymerization reaction system, for example, phthalic acid ester such as dioctyl phthalate, other fatty acid ester or xylene. ,
Organic compounds such as toluene and cyclohexane can be added.
【００２８】さらに、難燃剤、難燃助剤、帯電防止剤、
導電化剤、粒度分布調整剤等の一般的に発泡性樹脂粒子
の製造に使用されている添加剤を適宜添加したり、ブタ
ジエンゴム、スチレン・ブタジエンゴム等のゴム成分を
混合することもできる。本発明のスチレン系発泡性樹脂
粒子の製造方法では、懸濁重合の途中又は懸濁重合終了
後に発泡剤を添加して重合体粒子に発泡剤を含有せしめ
た発泡性重合体粒子を製造する。Further, a flame retardant, a flame retardant aid, an antistatic agent,
Additives generally used for the production of expandable resin particles such as a conductive agent and a particle size distribution adjusting agent may be appropriately added, or a rubber component such as butadiene rubber or styrene / butadiene rubber may be mixed. In the method for producing styrene-based expandable resin particles of the present invention, a foaming agent is added to the polymer particles during or after the suspension polymerization to produce foamable polymer particles.
【００２９】その発泡剤としては、たとえばプロパン、
ノルマルブタン、イソブタン、ノルマルペンタン、イソ
ペンタン、ネオペンタン、ヘキサン等の脂肪族炭化水
素；シクロブタン、シクロペンタン等の脂環族炭化水
素；塩化メチル、ジクロルフルオロメタン等のハロゲン
化炭化水素等の物理発泡剤；さらには炭酸ガス、窒素、
アンモニア等の無機ガスが挙げられる。これらの発泡剤
は１種類を単独で、又は２種以上を併用して使用でき
る。発泡剤は、通常、生成重合体粒子中の発泡剤含有量
が１〜２０重量％になる程度の量が供給される。Examples of the foaming agent include propane,
Aliphatic hydrocarbons such as normal butane, isobutane, normal pentane, isopentane, neopentane and hexane; alicyclic hydrocarbons such as cyclobutane and cyclopentane; physical blowing agents such as halogenated hydrocarbons such as methyl chloride and dichlorofluoromethane Further carbon dioxide, nitrogen,
Inorganic gas such as ammonia can be used. These foaming agents can be used alone or in combination of two or more. The foaming agent is usually supplied in such an amount that the content of the foaming agent in the produced polymer particles is 1 to 20% by weight.
【００３０】本発明のスチレン系発泡性趣旨粒子を製造
する方法において、こうして得られたスチレン系発泡性
樹脂粒子を水性媒体から分離し、温度Ｔが、次式の範囲 Ｔｇ−２０℃≦Ｔ≦Ｔｇ＋１０℃ （尚、Ｔｇは重合体のガラス転移温度である。）、好ま
しくは２５℃以上、更に好ましくは３０℃以上であっ
て、好ましくは５５℃以下、更に好ましくは５０℃以下
で、発泡剤を３〜２０重量％逸散させるのが肝要であ
る。In the method for producing styrenic expandable particles of the present invention, the styrenic expandable resin particles thus obtained are separated from the aqueous medium, and the temperature T is in the range of the following formula: Tg-20 ° C. ≦ T ≦ Tg + 10 ° C. (where Tg is the glass transition temperature of the polymer), preferably 25 ° C. or higher, more preferably 30 ° C. or higher, preferably 55 ° C. or lower, more preferably 50 ° C. or lower. It is essential to dissipate 3 to 20% by weight.
【００３１】Ｔｇ−２０℃未満の温度で加熱しても発泡
剤の逸散率が低く工業的に不利であるし、逆にＴｇ＋１
０℃を超える温度で加熱すると得られる発泡性樹脂粒子
が微発泡し、白化現象を起こすので好ましくない。ま
た、発泡剤の逸散率が少な過ぎると、それを用いて得ら
れる成形体の外観向上の効果が充分ではなく、逆に逸散
率が多過ぎてもそれに見合う外観向上の効果が得られな
いばかりでなく、発泡剤が逸散され過ぎるため、融着が
不充分となりやすい。成形体により良い外観を望む場合
は５重量％以上発泡剤を逸散させるのが好ましい。Even if heated at a temperature lower than Tg-20 ° C., the dissipation factor of the foaming agent is low, which is industrially disadvantageous, and conversely, Tg + 1.
When the heating is performed at a temperature higher than 0 ° C., the expandable resin particles obtained are finely foamed and a whitening phenomenon occurs, which is not preferable. Further, if the escape rate of the foaming agent is too low, the effect of improving the appearance of the molded product obtained using it is not sufficient, and conversely, if the escape rate is too high, the effect of improving the appearance is obtained. Not only that, but because the blowing agent is scattered too much, fusion is likely to be inadequate. It is preferable to disperse the foaming agent in an amount of 5% by weight or more when a better appearance is desired for the molded product.
【００３２】尚、本発明におけるＴｇは上述した通りガ
ラス転移温度であるが、このＴｇは、指差走査型熱量計
（ＤＳＣ）において、スチレン系発泡性樹脂粒子を密閉
式耐圧容器に入れ、密閉後１０Ｋ／分の昇温速度で昇温
した際の立ち下がり温度（吸熱を開始する温度）とす
る。曲線が緩やかで開始点が明確でない場合は、各々を
理想的な直線と見なし、その交点とする。The Tg in the present invention is the glass transition temperature as described above, and this Tg is measured in a finger-point scanning calorimeter (DSC) by placing the styrenic expandable resin particles in a hermetic pressure-resistant container and sealing. It is the falling temperature (temperature at which heat absorption starts) when the temperature is raised at a heating rate of 10 K / min. If the curve is gentle and the starting point is not clear, consider each as an ideal straight line and use it as the intersection.
【００３３】尚また、本発明における発泡剤の逸散率は
加熱処理前の含有発泡剤量と処理後の含有発泡剤量の差
を、処理前の含有発泡剤量で除した値とする。本発明に
おける発泡剤を逸散させる手法については、特に限定さ
れるものではなく、所定の温度で所定の比率だけ発泡剤
が逸散され得れば良い。例えば、原料投入口と排出口、
所定の温度の空気若しくは不活性ガスの導入口と排出口
を有する容器に原料を投入し、所定の温度の空気若しく
は不活性ガスを容器内に導入し、所定の量の発泡剤を逸
散させる。この際、空気若しくは不活性ガスの導入は、
断続的でも連続的でも良く、また、原料の投入及び逸散
処理も、バッチ方式であっても連続方式であっても良
い。更には、逸散した発泡剤は、工業的な見地や環境的
見地から、回収するのが好ましい。Further, the dissipation rate of the foaming agent in the present invention is a value obtained by dividing the difference between the content of the foaming agent before the heat treatment and the content of the foaming agent after the treatment by the content of the foaming agent before the treatment. The method of dissipating the foaming agent in the present invention is not particularly limited as long as the foaming agent can be dissipated by a predetermined ratio at a predetermined temperature. For example, raw material inlet and outlet,
The raw material is put into a container having an inlet or outlet for air or inert gas at a predetermined temperature, and air or an inert gas at a predetermined temperature is introduced into the container to disperse a predetermined amount of foaming agent. . At this time, the introduction of air or inert gas is
It may be intermittent or continuous, and the raw material charging and the dissipating treatment may be batch system or continuous system. Furthermore, it is preferable to recover the escaped blowing agent from an industrial viewpoint and an environmental viewpoint.
【００３４】また、上記した発泡剤を逸散させる工程に
先立って、操作上の観点からある程度得られた発泡性樹
脂粒子を発泡剤が実質的に逸散しない程度に乾燥させて
おいても良い。Further, prior to the above-mentioned step of dissipating the foaming agent, the expandable resin particles obtained to some extent from an operational point of view may be dried to such an extent that the foaming agent does not substantially dissipate. .
【００３５】[0035]
【実施例】以下に、実施例及び比較例をあげて本発明を
さらに詳述するが、本発明はこれら実施例に限定される
ものではない。 実施例１ 撹拌器付き５０リットルオートクレーブに、イオン交換
水２０リットル、第３リン酸カルシウム（太平化学産業
社製）５０ｇ、ドデシルベンゼンスルホン酸ナトリウム
０．６ｇを投入した。次いで撹拌下に、ｔ−ブチルパー
オキシ２−エチルヘキサノエート４５ｇ、ｔ−ブチルパ
ーオキシ２−エチルヘキシルモノカーボネート２７ｇ、
可塑化剤としてシクロヘキサン２７０ｇをスチレンモノ
マー１８ｋｇに溶解させたものを投入した。The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 To a 50-liter autoclave equipped with a stirrer, 20 liters of ion-exchanged water, 50 g of tricalcium phosphate (manufactured by Taihei Chemical Industry Co., Ltd.), and 0.6 g of sodium dodecylbenzenesulfonate were charged. Then, with stirring, 45 g of t-butylperoxy 2-ethylhexanoate, 27 g of t-butylperoxy 2-ethylhexyl monocarbonate,
As a plasticizer, 270 g of cyclohexane dissolved in 18 kg of styrene monomer was added.
【００３６】オートクレーブ内を窒素ガスで置換した
後、撹拌下で３０分間室温のまま放置し、１時間半かけ
て９０℃まで昇温した。内温が６０℃に達した時点で、
過硫酸カリウムの１％水溶液を１２ｇ添加した。次いで
９０℃から１００℃まで５時間半かけて昇温させ、その
途中の４時間３０分目にオートクレーブから懸濁液をサ
ンプリングし、重合転化率を調べたところ、７５％であ
った。ここで２５％の塩化ナトリウム水溶液７００ｇ
（水性媒体に対する濃度は０．１５ｍｏｌ／ｌに相当）
を５分間かけてオートクレーブ内に投入した後、ブタン
１．７ｋｇをオートクレーブ内に圧入した。更に１００
℃から１１０℃まで１時間半かけて昇温し、２時間保持
した。After purging the inside of the autoclave with nitrogen gas, the autoclave was left under stirring for 30 minutes at room temperature and then heated to 90 ° C. over 1 hour and a half. When the internal temperature reaches 60 ° C,
12 g of a 1% aqueous solution of potassium persulfate was added. Next, the temperature was raised from 90 ° C. to 100 ° C. over 5 hours and 30 minutes, and the suspension was sampled from the autoclave at 4 hours and 30 minutes in the middle, and the polymerization conversion rate was 75%. 700 g of 25% aqueous sodium chloride solution
(The concentration in the aqueous medium is equivalent to 0.15 mol / l)
Was charged into the autoclave over 5 minutes, and then 1.7 kg of butane was pressed into the autoclave. 100 more
The temperature was raised from 1 ° C. to 110 ° C. over 1 hour and a half, and kept for 2 hours.
【００３７】３０℃まで４時間かけて冷却した後、酸洗
浄して発泡樹脂粒子表面に付着していた第３リン酸カル
シウムを除去した。その後、遠心分離器にて脱水し、帯
電防止０としてビスヒドロキシエチル脂肪族アミン（ラ
イオンアクゾ社製 商品名アーモスタット４１０）０．
０５％を添加した後、流動乾燥装置で表面付着水分を除
去し発泡性樹脂粒子を得た。その後、篩で０．８〜１．
２ｍｍの粒分を製出し、ブロッキング防止剤としてステ
アリン酸亜鉛０．１％を樹脂粒子表面に付着させた後、
箱型通気乾燥器内に入れ４０℃で２０分間加熱して、発
泡剤を逸散させて本発明のスチレン系発泡性樹脂粒子を
得た。尚、加熱前のスチレン系発泡性樹脂粒子の一部を
取り出し、ガラス転移温度を測定したところ、３８℃で
あった。After cooling to 30 ° C. for 4 hours, the product was washed with an acid to remove the tertiary calcium phosphate adhering to the surface of the expanded resin particles. Then, it was dehydrated in a centrifuge and bishydroxyethyl aliphatic amine (trade name Armostat 410 manufactured by Lion Akzo Co.) was used as an antistatic agent.
After adding 05%, the water adhering to the surface was removed by a fluidized drying device to obtain expandable resin particles. After that, 0.8 to 1.
After producing 2 mm particles and attaching zinc stearate 0.1% as an anti-blocking agent to the resin particle surface,
It was placed in a box-type ventilation dryer and heated at 40 ° C. for 20 minutes to disperse the foaming agent to obtain styrene-based expandable resin particles of the present invention. A part of the styrenic expandable resin particles before heating was taken out and the glass transition temperature was measured. As a result, it was 38 ° C.
【００３８】このスチレン系発泡性樹脂粒子を予備発泡
機（ダイセン工業社製、ＤＹＨ−８５０）で、常法によ
り嵩密度２０ｇ／ｌに発泡させ、こうして得られた予備
発泡粒子を、１日室温で放置（熟成）した後、これを２
８×３５×１５ｃｍの大きさの箱型の金型内に充填し
０．６ｋｇｆ／ｃｍ2 ・Ｇの蒸気吹き込み圧で２０秒間
加熱して成形し、発泡成形体を得た。The styrenic expandable resin particles were expanded to a bulk density of 20 g / l by a conventional method using a pre-expanding machine (DYH-850 manufactured by Daisen Kogyo Co., Ltd.), and the pre-expanded particles thus obtained were stored at room temperature for 1 day. After leaving (aging) in 2
It was filled in a box-shaped mold having a size of 8.times.35.times.15 cm, heated at a steam blowing pressure of 0.6 kgf / cm @ 2 .G for 20 seconds, and molded to obtain a foamed molded product.
【００３９】上記のようにして得られる本発明のスチレ
ン系発泡性樹脂粒子中のボイド数、表面スキン層厚み、
内部水分量、予備発泡粒子のセルの安定性及び発泡成形
体の表面外観、融着率及び落球衝撃強度高さを下記の方
法で評価し、その結果を表２に示した。The number of voids in the styrenic expandable resin particles of the present invention obtained as described above, the surface skin layer thickness,
The internal water content, the cell stability of the pre-expanded particles, the surface appearance of the foamed molded product, the fusion rate and the drop ball impact strength were evaluated by the following methods, and the results are shown in Table 2.
【００４０】評価方法 １）ボイド数；スチレン系発泡性樹脂粒子の中心付近を
通る断面をミクロトームで切り出し、この断面を走査型
電子顕微鏡で観察し、写真を撮る。この写真より、表面
部のボイドの計測には０．１ｍｍ×０．３ｍｍの範囲か
ら、また内部のボイドの計測には０．２ｍｍ×０．２ｍ
ｍの範囲のボイド数を計測し、これを１ｍｍ2 当りの値
に換算して求めた。Evaluation method 1) Void number: A cross section passing through the vicinity of the center of the styrenic expandable resin particles is cut out with a microtome, the cross section is observed with a scanning electron microscope, and a photograph is taken. From this photograph, it is possible to measure the surface voids from the range of 0.1mm × 0.3mm, and to measure the internal voids 0.2mm × 0.2m.
The number of voids in the range of m was measured, and this was converted into a value per 1 mm 2 to obtain the value.
【００４１】２）表面スキン層厚み；スチレン系樹脂粒
子を、１００℃の水蒸気で加熱して約２倍の体積に発泡
させた。この予備発泡粒子の中心付近を通る断面を切り
出し、この断面を走査型電子顕微鏡で観察し、写真を撮
り、表面スキン層（表面部の発泡していない層）の厚み
を計測した。2) Surface skin layer thickness: Styrene resin particles were heated with steam at 100 ° C. to foam to a volume about twice that of the styrene resin particles. A cross-section passing through the vicinity of the center of the pre-expanded particles was cut out, the cross-section was observed with a scanning electron microscope, a photograph was taken, and the thickness of the surface skin layer (non-foamed surface layer) was measured.
【００４２】３）内部水分量；製造後２４時間以内及び
発泡剤逸散処理工程後のスチレン系発泡性樹脂粒子を、
加熱溶融させ生じた水分をカールフィッシャー法にて測
定した。3) Internal water content; styrene-based expandable resin particles within 24 hours after production and after the step of dissipating the blowing agent,
The water content produced by heating and melting was measured by the Karl Fischer method.
【００４３】４）予備発泡粒子のセルの安定性；スチレ
ン系発泡性樹脂粒子を下記〜の条件で保存後、上記
方法にて予備発泡、成形してセルの安定性を目視により
下記基準にて評価した。 オートクレーブより抜きだし表面付着水分を除去した
直後 オートクレーブより抜きだし表面付着水分を除去した
後、０℃にて７日間保管（熟成）した後4) Cell stability of pre-expanded particles: Styrene-based expandable resin particles were stored under the following conditions, and then pre-expanded and molded by the above method, and the stability of the cells was visually observed according to the following criteria. evaluated. Immediately after removing water adhering to the surface after extracting from the autoclave After removing water adhering to the surface after extracting from the autoclave, after storage (aging) for 7 days at 0 ° C
【００４４】オートクレーブより抜きだし表面付着水
分を除去した後、４０℃にて３日間保管した後 良；セル荒れやセルムラが生じたりせず、保管条件によ
ってセルが変化しない。 不良；セル荒れやセルムラが生じ、保管条件によってセ
ルが変化する。After removal from the autoclave to remove water adhering to the surface, it was stored at 40 ° C. for 3 days. Good; cell roughness and cell unevenness did not occur, and cells did not change depending on storage conditions. Defective: Roughness and unevenness of cells occur, and the cells change depending on storage conditions.
【００４５】５）表面外観；発泡成形体の表面外観を目
視により下記基準にて評価した。 優；粒子間の間隙がなく、見栄えが非常に良い。 良；粒子間の間隙が殆どなく、見栄えがよい。 やや不良；粒子間の間隙があり、外観がやや劣る。 不良；粒子間の間隙が多くあり、見栄えが悪い。5) Surface appearance: The surface appearance of the foamed molded product was visually evaluated according to the following criteria. Excellent: There are no gaps between the particles and the appearance is very good. Good: There is almost no gap between particles, and the appearance is good. Slightly bad: There is a gap between particles, and the appearance is slightly inferior. Poor: There are many gaps between the particles and the appearance is poor.
【００４６】６）融着率；成形体を手で割った時の破断
面のうち、発泡粒子間の境界面で割れたものではなく、
発泡粒子の内部で引き裂かれた粒子の全粒子数に対する
割合（％）とする。 ７）落球衝撃強度高さ；発泡成形体に重量２５５ｇの剛
球を垂直に落下させ発泡成形体の５０％が破壊したとこ
ろの落下高さとする。（ＪＩＳ Ｋ７２１１に準拠）6) Fusing rate: Of the fractured surfaces when the molded body is broken by hand, it is not cracked at the boundary surface between the foamed particles,
The ratio (%) of the number of particles torn inside the expanded particles to the total number of particles. 7) Falling ball impact strength height: A drop height at which a hard sphere weighing 255 g is dropped vertically onto a foamed molded product and 50% of the foamed molded product is broken. (Based on JIS K7211)
【００４７】実施例２ ２５％の塩化ナトリウム水溶液の添加量を１５００ｇ
（水性媒体に対する濃度は０．３２ｍｏｌ／ｌに相当）
とし、発泡剤を逸散させる工程における時間を１０分と
した以外は、実施例１と同様に行った。 実施例３ ２５％の塩化ナトリウム水溶液の添加量を３００ｇ（水
性媒体に対する濃度は０．０６ｍｏｌ／ｌに相当）と
し、その添加時期を重合開始後４時間目（その時の重合
転化率を調べたところ６０％であった。）とした以外
は、実施例１と同様に行った。Example 2 1500 g of 25% sodium chloride aqueous solution was added.
(The concentration for the aqueous medium is equivalent to 0.32 mol / l)
Then, the same procedure as in Example 1 was performed except that the time in the step of allowing the foaming agent to dissipate was 10 minutes. Example 3 The amount of 25% sodium chloride aqueous solution added was 300 g (concentration with respect to aqueous medium was equivalent to 0.06 mol / l), and the addition time was 4 hours after initiation of polymerization (polymerization conversion rate at that time was examined. Was 60%.) The same operation as in Example 1 was performed.
【００４８】実施例４ 発泡剤を逸散させる工程における時間を４０分とした以
外は、実施例３と同様に行った。 実施例５ ２５％の塩化ナトリウム水溶液に代えて、酢酸ナトリウ
ムの２０％水溶液１４５０ｇ（水性媒体に対する濃度は
０．１１ｍｏｌ／ｌに相当）を冷却を開始した時点（そ
の時の重合転化率を調べたところ９９％であった。）を
添加し、発泡剤を逸散させる工程における温度を３５℃
とし、同時間を６０分とした以外は、実施例１と同様に
行った。Example 4 The procedure of Example 3 was repeated, except that the time required for the step of allowing the foaming agent to escape was 40 minutes. Example 5 1450 g of a 20% aqueous solution of sodium acetate (concentration with respect to the aqueous medium corresponds to 0.11 mol / l) was started instead of the 25% aqueous sodium chloride solution (the polymerization conversion rate at that time was examined) Was 99%), and the temperature in the step of dissipating the blowing agent was set to 35 ° C.
And the same procedure as in Example 1 except that the same time was set to 60 minutes.
【００４９】実施例６ スチレンモノマー１８ｋｇを、粒径が０．２ｍｍ以下の
スチレン系発泡性樹脂粒子３．６ｋｇをスチレンモノマ
ー１４．４ｋｇに溶解させたものに変え、また発泡剤を
逸散させる工程における温度を４５℃とし、同時間を２
０分とした以外は、実施例５と同様に行った。Example 6 A process in which 18 kg of styrene monomer is changed to 3.6 kg of styrenic expandable resin particles having a particle size of 0.2 mm or less dissolved in 14.4 kg of styrene monomer, and the blowing agent is dispersed. Temperature at 45 ° C and the same time as 2
The same procedure as in Example 5 was carried out except that the time was 0 minutes.
【００５０】実施例７ スチレン単量体に、重合開始剤、可塑化剤の他にメタク
リル酸メチル重合体（三菱レイヨン社製、ＢＲ−８０）
０．５ｇ（スチレン系単量体に対して０．００２８％に
相当）を添加して重合を開始し、内温が６０℃に達した
時点で、過硫酸カリウムの１％水溶液を５．４ｇ添加し
て実験を行なった。その他の条件は実施例１と同様に行
なった。Example 7 A styrene monomer, a polymerization initiator, a plasticizer, and a methyl methacrylate polymer (BR-80, manufactured by Mitsubishi Rayon Co., Ltd.)
Polymerization was started by adding 0.5 g (corresponding to 0.0028% with respect to the styrene monomer), and when the internal temperature reached 60 ° C., 5.4 g of a 1% aqueous solution of potassium persulfate was added. Experiments were carried out by adding. Other conditions were the same as in Example 1.
【００５１】実施例８ メタクリル酸メチル重合体（三菱レイヨン社製、ＢＲ−
８０）の添加量を１．８ｇ（スチレン系単量体に対して
０．０１％に相当）、過硫酸カリウムの１％水溶液の添
加量を１８ｇにして重合を行なった。２５％の塩化ナト
リウム水溶液は、冷却を開始した時点（その時の重合転
化率を調べたところ、９９％であった。）に、７００ｇ
（水性媒体に対する濃度は０．１５ｍｏｌ／ｌに相当）
を１０分間かけてオートクレーブ内に投入し、また、発
泡剤を逸散させる工程における時間を３０分とした以外
は、実施例１と同様に行なった。Example 8 Methyl methacrylate polymer (BR-produced by Mitsubishi Rayon Co., Ltd.)
Polymerization was carried out with the addition amount of 80) being 1.8 g (corresponding to 0.01% with respect to the styrene-based monomer) and the addition amount of a 1% aqueous solution of potassium persulfate being 18 g. A 25% aqueous solution of sodium chloride was 700 g at the time when the cooling was started (the polymerization conversion rate at that time was 99%).
(The concentration in the aqueous medium is equivalent to 0.15 mol / l)
Was charged into the autoclave over 10 minutes, and the procedure in Example 1 was repeated, except that the time for the step of causing the foaming agent to dissipate was 30 minutes.
【００５２】実施例９ 過硫酸カリウムの１％水溶液の添加量を９ｇにして重合
を行い、９０℃から１００℃まで５時間半かけて昇温さ
せる途中の４時間目（その時の重合転化率を調べたとこ
ろ、６０％であった。）に酢酸ナトリウムの２０％水溶
液１４５０ｇ（水性媒体に対する濃度は０．１ｍｏｌ／
ｌに相当）を１０分間かけてオートクレーブ内に投入
し、重合終了後は３０℃まで６時間かけて冷却し、ま
た、発泡剤を逸散させる工程における時間を１０分とし
た以外は、実施例１と同様に行なった。Example 9 Polymerization was carried out with 9 g of a 1% aqueous solution of potassium persulfate being added, and polymerization was carried out for 4 hours at a temperature of 90 ° C. to 100 ° C. over a period of 5 hours. When examined, it was 60%.) 1450 g of a 20% aqueous solution of sodium acetate (concentration in an aqueous medium was 0.1 mol /
(equivalent to 1) was charged into the autoclave over 10 minutes, cooled to 30 ° C. over 6 hours after completion of the polymerization, and the time in the step of allowing the foaming agent to escape was 10 minutes. The same procedure as in 1 was performed.
【００５３】実施例１０ メタクリル酸メチル重合体の代わりに、ヘキサブロモシ
クロドデカン（デッドシーブロム社製、ＨＢＣＤ−ＬＭ
Ｓ）１００ｇ（スチレン系単量体に対して０．６０％に
相当）を添加し、２５％の塩化ナトリウム水溶液の添加
量を５００ｇ（水性媒体に対する濃度は０．１１ｍｏｌ
／ｌに相当）にし、重合終了後は３０℃まで３時間かけ
て冷却し、また、発泡剤を逸散させる工程における温度
を３５℃とし、同時間を５０分とした以外は、実施例７
と同様に行った。Example 10 Instead of the methyl methacrylate polymer, hexabromocyclododecane (manufactured by Dead Sea Brom Co., HBCD-LM
S) 100 g (corresponding to 0.60% with respect to the styrene-based monomer) was added, and the addition amount of the 25% sodium chloride aqueous solution was 500 g (concentration with respect to the aqueous medium was 0.11 mol.
Example 1 except that the temperature in the step of dissipating the blowing agent was 35 ° C. and the same time was 50 minutes after the completion of the polymerization.
The same was done.
【００５４】実施例１１ 過硫酸カリウムの１％水溶液の添加時期を、９０℃から
１００℃まで５時間半かけて昇温させる途中の１時間目
（その時の重合転化率を調べたところ、２５％であっ
た。）に変更し、また発泡剤を逸散させる工程における
温度を４５℃とした以外の条件は、実施例９と同様に行
ない評価した。Example 11 A 1% aqueous solution of potassium persulfate was added during the first hour during the heating from 90 ° C. to 100 ° C. over 5 hours and a half (polymerization conversion rate at that time was 25%. The conditions were the same as in Example 9 except that the temperature in the step of causing the foaming agent to escape was 45 ° C.
【００５５】実施例１２ ２５％の塩化ナトリウム水溶液の添加時期を、９０℃か
ら１００℃まで５時間半かけて昇温させる途中の２時間
半目（その時の重合転化率を調べたところ、４０％であ
った。）に変更し、また発泡剤を逸散させる工程におけ
る温度を３０℃とし、同時間を６０分とした以外の条件
は、実施例９と同様に行ない評価した。 実施例１３ 過硫酸塩を添加しなかった以外は、実施例７と同様に行
った。Example 12 The addition time of a 25% sodium chloride aqueous solution was raised from 90 ° C. to 100 ° C. over a period of 5 hours and a half hours (2 hours and a half). The polymerization conversion rate at that time was 40%. The conditions were the same as in Example 9 except that the temperature was changed to 30 ° C. in the step of causing the foaming agent to dissipate, and the same time was changed to 60 minutes. Example 13 Example 13 was repeated except that the persulfate was not added.
【００５６】比較例１ ２５％の塩化ナトリウム水溶液を添加しなかった以外
は、実施例１と同様に行った。 比較例２ 実施例１に於て、２５％の塩化ナトリウム水溶液を添加
せずに、発泡剤を逸散させる工程における温度を４５℃
とし、同時間を６０分とした以外は、実施例１と同様に
行った。Comparative Example 1 Example 1 was repeated except that the 25% sodium chloride aqueous solution was not added. Comparative Example 2 In Example 1, the temperature in the step of dissipating the foaming agent was 45 ° C. without adding a 25% sodium chloride aqueous solution.
And the same procedure as in Example 1 except that the same time was set to 60 minutes.
【００５７】比較例３ 発泡剤を逸散させる工程を行わなかった以外は、実施例
３と同様に行った。 比較例４ ２５％の塩化ナトリウム水溶液を添加しなかった以外
は、実施例６と同様に行った。Comparative Example 3 The procedure of Example 3 was repeated except that the step of dissipating the foaming agent was omitted. Comparative Example 4 The procedure of Example 6 was repeated except that the 25% sodium chloride aqueous solution was not added.
【００５８】比較例５ 実施例７に於て、メタクリル酸メチル重合体（三菱レイ
ヨン社製、ＢＲ−８０）の添加量を０．２ｇ（スチレン
系単量体に対して０．００１１％に相当）にし、９０℃
から１００℃まで５時間半かけて昇温させる途中の４時
間目（その時の重合転化率を調べたところ、６０％であ
った。）に塩化ナトリウム７ｋｇ（水性媒体に対する濃
度は６ｍｏｌ／ｌに相当）を１０分間かけてオートクレ
ーブ内に投入し、重合終了後は３０℃まで８時間かけて
冷却した。また、発泡剤の逸散処理時間を１０分にして
実験を行い、同様の評価をした。Comparative Example 5 In Example 7, the amount of methyl methacrylate polymer (BR-80 manufactured by Mitsubishi Rayon Co., Ltd.) added was 0.2 g (corresponding to 0.0011% with respect to the styrene monomer). ) And 90 ℃
To 100 ° C. over a period of 5 and a half hours, 7 kg of sodium chloride was added to 4 kg of the 4th hour (inspection of the polymerization conversion rate at that time was 60%) (concentration to the aqueous medium was 6 mol / l. ) Was charged into the autoclave over 10 minutes, and after completion of the polymerization, it was cooled to 30 ° C. over 8 hours. Further, an experiment was conducted with the escape treatment time of the foaming agent set to 10 minutes, and the same evaluation was performed.
【００５９】比較例６ 過硫酸塩と塩化ナトリウム水溶液を添加しなかった以外
は、実施例１０と同様の実験と評価を行なった。 比較例７ ２５％の塩化ナトリウム水溶液７００ｇ（水性媒体に対
する濃度は０．１５ｍｏｌ／ｌに相当）の添加時期を９
０℃に到達した時点（その時の重合転化率を調べたとこ
ろ１０％であった）とした以外は、実施例８と同様の実
験を行なった。Comparative Example 6 The same experiment and evaluation as in Example 10 were carried out except that the persulfate and the sodium chloride aqueous solution were not added. Comparative Example 7 The addition timing of 700 g of 25% aqueous sodium chloride solution (concentration to the aqueous medium corresponds to 0.15 mol / l) was changed to 9
The same experiment as in Example 8 was carried out except that the temperature reached 0 ° C. (the polymerization conversion rate at that time was 10%).
【００６０】比較例８ ２５％の塩化ナトリウム水溶液７００ｇ（水性媒体に対
する濃度は０．１５ｍｏｌ／ｌに相当）の添加時期を９
０℃から１００℃まで５時間半かけて昇温させる途中の
４時間目に添加し、過硫酸カリウム１％水溶液１８ｇの
添加時期を、その後の４時間半目とし、発泡剤を逸散さ
せる工程における時間を１０分とした以外は、実施例１
と同様の実験と評価を行なった。Comparative Example 8 700 g of a 25% aqueous sodium chloride solution (concentration with respect to the aqueous medium corresponds to 0.15 mol / l) was added at 9 times.
It is added in the 4th hour while heating from 0 ° C to 100 ° C for 5 hours and a half, and the addition time of 18 g of 1% aqueous solution of potassium persulfate is the 4th and a half hours after that, in the step of dispersing the foaming agent. Example 1 except that the time was 10 minutes
The same experiment and evaluation were performed.
【００６１】[0061]
【表１】 [Table 1]
【００６２】[0062]
【表２】 [Table 2]
【００６３】[0063]
【表３】 [Table 3]
【００６４】[0064]
【表４】 [Table 4]
【００６５】[0065]
【発明の効果】本発明の発泡性樹脂粒子は予備発泡させ
た後の予備発泡粒子のセル変化が少ない、即ち保管条件
によって影響の受けにくく、それを用いて成形された発
泡成形体は表面が美麗で且つ充分な機械的強度を有する
ものである。EFFECTS OF THE INVENTION The expandable resin particles of the present invention have little change in cells of the pre-expanded particles after being pre-expanded, that is, they are not easily affected by storage conditions, and the surface of a foam-molded article molded using the same is small. It is beautiful and has sufficient mechanical strength.
Claims (7)
通る断面での表面から半径方向０．１ｍｍ以内のボイド
数が１００個／ｍｍ2 以下であり、かつ、２倍の体積に
発泡させた時の表面スキン層が１０〜１００μｍである
ことを特徴とするスチレン系発泡性樹脂粒子。1. The number of voids within a radius of 0.1 mm from the surface of a cross section passing through the center of the styrenic expandable resin particles is 100 / mm 2 or less, and the foam is expanded to a double volume. Styrene-based expandable resin particles having a surface skin layer of 10 to 100 μm.
通る断面での表面から半径方向０．３ｍｍ以内を除く半
径方向内部のボイド数が２５０個／ｍｍ2 以上であるこ
とを特徴とする、請求項１記載のスチレン系発泡性樹脂
粒子。2. The number of voids inside the radial direction excluding within 0.3 mm in the radial direction from the surface of the cross section passing through the center of the styrenic expandable resin particles is 250 / mm 2 or more, The styrenic expandable resin particle according to claim 1.
３〜３ｍｍであることを特徴とする、請求項１記載のス
チレン系発泡性樹脂粒子。3. The particle size of styrenic expandable resin particles is 0.
The styrene-based expandable resin particle according to claim 1, which has a diameter of 3 to 3 mm.
剤の存在下で水性媒体中で懸濁させ、発泡剤を含有させ
て発泡性樹脂粒子を製造する方法において、前記単量体
の重合転化率が３０％以上の時点で、水性媒体に対する
濃度が、０．０２〜５．０ｍｏｌ／ｌになるような量の
電解質を添加して重合する工程、及び、スチレン系発泡
性樹脂粒子を水性媒体から分離した後、温度Ｔが、次式
の範囲 Ｔｇ−２０℃≦Ｔ≦Ｔｇ＋１０℃ （尚、Ｔｇは重合体のガラス転移温度である。）で発泡
剤を３〜２０重量％逸散させる工程からなることを特徴
とするスチレン系発泡性樹脂粒子の製造方法。4. A method for producing expandable resin particles by suspending a styrenic monomer in an aqueous medium in the presence of a polymerization initiator and a suspending agent, to produce a foamable resin particle. At a time when the polymerization conversion rate of 30% or more is 30% or more, a step of adding an amount of an electrolyte such that the concentration in the aqueous medium becomes 0.02 to 5.0 mol / l, and polymerizing, and styrene-based expandable resin particles After separating from the aqueous medium, the temperature T is in the range of the following formula: Tg-20 ° C ≤ T ≤ Tg + 10 ° C (where Tg is the glass transition temperature of the polymer) and the blowing agent is 3 to 20% by weight. A process for producing styrenic expandable resin particles, which comprises a step of dispersing.
ウム、塩化カリウム、塩化カルシウム、硫酸ナトリウ
ム、硫酸マグネシウム、硫酸カリウム、炭酸ナトリウ
ム、炭酸カリウム、酢酸ナトリウム、安息香酸ナトリウ
ム、琥珀酸二ナトリウムからなる群から選ばれる少なく
とも１種である、請求項４記載のスチレン系発泡性樹脂
粒子の製造方法。5. The electrolyte is selected from the group consisting of sodium chloride, magnesium chloride, potassium chloride, calcium chloride, sodium sulfate, magnesium sulfate, potassium sulfate, sodium carbonate, potassium carbonate, sodium acetate, sodium benzoate and disodium succinate. The method for producing styrenic expandable resin particles according to claim 4, which is at least one of the following.
が、２５℃〜５５℃であることを特徴とする、請求項４
記載のスチレン系発泡性樹脂粒子の製造方法。6. The temperature in the step of dissipating the blowing agent is 25 ° C. to 55 ° C. 4.
A method for producing the styrenic expandable resin particles described.
に、過硫酸のアルカリ金属塩若しくはアンモニウム塩を
水性媒体に対し０．５〜３０ｐｐｍになるような量添加
することを特徴とする、請求項４記載のスチレン系発泡
性樹脂粒子の製造方法。7. The method is characterized in that an alkali metal salt or ammonium salt of persulfuric acid is added in an amount of 0.5 to 30 ppm with respect to an aqueous medium while the polymerization conversion rate of the monomer is 0 to 30%. The method for producing styrenic expandable resin particles according to claim 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27396295A JP3599450B2 (en) | 1995-10-23 | 1995-10-23 | Styrene-based expandable resin particles and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27396295A JP3599450B2 (en) | 1995-10-23 | 1995-10-23 | Styrene-based expandable resin particles and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09111035A true JPH09111035A (en) | 1997-04-28 |
| JP3599450B2 JP3599450B2 (en) | 2004-12-08 |
Family
ID=17535012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27396295A Expired - Fee Related JP3599450B2 (en) | 1995-10-23 | 1995-10-23 | Styrene-based expandable resin particles and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3599450B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007023120A (en) * | 2005-07-14 | 2007-02-01 | Fuji Xerox Co Ltd | Maleimide group containing porous crosslinked polystyrene particle and method for producing the same |
| JP2010229375A (en) * | 2009-03-30 | 2010-10-14 | Sekisui Plastics Co Ltd | Foamable polystyrene base resin particle and method for manufacturing the same, preparatorily foamed particle and foamed product |
| JP2012177033A (en) * | 2011-02-25 | 2012-09-13 | Sekisui Plastics Co Ltd | Expandable polystyrene-based resin particle, expanded particle, and expansion molded body |
| US20130309800A1 (en) * | 2011-01-31 | 2013-11-21 | United Initiators Gmbh & Co. Kg | Peroxide Blends For Cross-Linking Ethylene Vinyl Acetate In An Accelerated Manner |
-
1995
- 1995-10-23 JP JP27396295A patent/JP3599450B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007023120A (en) * | 2005-07-14 | 2007-02-01 | Fuji Xerox Co Ltd | Maleimide group containing porous crosslinked polystyrene particle and method for producing the same |
| JP2010229375A (en) * | 2009-03-30 | 2010-10-14 | Sekisui Plastics Co Ltd | Foamable polystyrene base resin particle and method for manufacturing the same, preparatorily foamed particle and foamed product |
| US20130309800A1 (en) * | 2011-01-31 | 2013-11-21 | United Initiators Gmbh & Co. Kg | Peroxide Blends For Cross-Linking Ethylene Vinyl Acetate In An Accelerated Manner |
| JP2014505148A (en) * | 2011-01-31 | 2014-02-27 | ユナイテッド・イニシエターズ・ゲーエムベーハー・ウント・コー・カーゲー | Peroxide blends to accelerate the cross-linking of ethylene vinyl acetate |
| US9382405B2 (en) * | 2011-01-31 | 2016-07-05 | United Initiators Gmbh & Co. Kg | Peroxide blends for cross-linking ethylene vinyl acetate in an accelerated manner |
| JP2012177033A (en) * | 2011-02-25 | 2012-09-13 | Sekisui Plastics Co Ltd | Expandable polystyrene-based resin particle, expanded particle, and expansion molded body |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3599450B2 (en) | 2004-12-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1608698B1 (en) | Expandable vinylaromatic polymers and process for their preparation | |
| JP3168882B2 (en) | Styrene-based expandable resin particles and method for producing the same | |
| WO2009096327A1 (en) | Expandable polystyrene resin beads, process for production thereof, pre-expanded beads and expanded moldings | |
| JP3171001B2 (en) | Styrenic expandable resin particles and suspension polymerization method for obtaining the same | |
| JP4326034B2 (en) | Styrenic expandable resin particles | |
| JPH09111035A (en) | Styrenic foamable resin granule and its production | |
| JP2002356575A (en) | Foamable polystyrene resin particles and foamed molded material | |
| JPH09221563A (en) | Preparation of expandable styrene polymer particle | |
| JP5528428B2 (en) | Method for reducing odor in composite resin particles | |
| JP3024522B2 (en) | Styrene-based expandable resin particles and expanded molded article obtained using the same | |
| JPH08109279A (en) | Expandable styrene polymer particle, its production and molded foam | |
| JP3532323B2 (en) | Foam molding | |
| JP2001220458A (en) | Foamable styrenic resin particle | |
| JP4771457B2 (en) | Method for producing styrene resin particles | |
| JP4026942B2 (en) | Method for producing styrene resin particles | |
| JP3597109B2 (en) | Method for producing expandable styrene resin particles, expandable styrene resin particles, and molded foam | |
| JP4463929B2 (en) | Method for producing styrene-based expandable resin particles | |
| JP4659462B2 (en) | Styrenic expandable resin particles, method for producing the same, pre-expanded particles, and expanded molded article | |
| JP4463938B2 (en) | Method for producing styrene-based expandable resin particles | |
| MX2008010736A (en) | Process for preparing expandable styrene polymers. | |
| JP3475416B2 (en) | Expandable styrenic resin particles, method for producing the same, and expanded molded article | |
| JPH0439339A (en) | Expandable thermoplastic resin particle | |
| JPH05295160A (en) | Production of expandable styrene resin particle | |
| JPH08295757A (en) | Expandable styrene resin particle and its production | |
| JPH08104772A (en) | Foamable styrene polymer particle, production thereof and foamed molding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20040209 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040407 |
|
| 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: 20040908 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040914 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20070924 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080924 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080924 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090924 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090924 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100924 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110924 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120924 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130924 Year of fee payment: 9 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |