JPH06298983A - Production of expandable thermoplastic resin particle - Google Patents
Production of expandable thermoplastic resin particleInfo
- Publication number
- JPH06298983A JPH06298983A JP5089848A JP8984893A JPH06298983A JP H06298983 A JPH06298983 A JP H06298983A JP 5089848 A JP5089848 A JP 5089848A JP 8984893 A JP8984893 A JP 8984893A JP H06298983 A JPH06298983 A JP H06298983A
- Authority
- JP
- Japan
- Prior art keywords
- thermoplastic resin
- particles
- foaming agent
- pressurized liquid
- resin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/34—Auxiliary operations
- B29C44/3461—Making or treating expandable particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2025/00—Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
- B29K2025/04—Polymers of styrene
- B29K2025/06—PS, i.e. polystyrene
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、発泡性熱可塑性樹脂粒
子の製造法、詳細には熱可塑性樹脂と発泡剤と特定量の
無機質粉末とを用いた溶融押出法による発泡性熱可塑性
樹脂粒子の製造法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing expandable thermoplastic resin particles, more specifically, expandable thermoplastic resin particles by a melt extrusion method using a thermoplastic resin, a foaming agent and a specific amount of inorganic powder. Manufacturing method.
【０００２】[0002]
【従来の技術】従来、発泡性熱可塑性樹脂粒子、例えば
発泡性スチレン系樹脂粒子の製造法としては、スチレン
系樹脂の懸濁重合中あるいは重合後に発泡剤を混合し含
浸させる懸濁重合法が一般的であるが、この製造法では
粒径の均一のものが得られず、ふるい分け等による粒度
調整が不可欠である。また、顔料等の着色剤による着色
粒子の製造も制約が多く、ほとんど実施されていない。
更に、この方法では廃品の発泡性熱可塑性樹脂粒子への
再生が不可能であるという課題もある。2. Description of the Related Art Conventionally, as a method for producing expandable thermoplastic resin particles, for example, expandable styrene resin particles, there is a suspension polymerization method in which a foaming agent is mixed and impregnated during or after suspension polymerization of the styrene resin. In general, this production method does not provide a uniform particle size, and it is essential to adjust the particle size by sieving. Further, there are many restrictions on the production of colored particles using a coloring agent such as a pigment, and almost no such production has been carried out.
Furthermore, this method also has a problem that it is impossible to recycle waste products into expandable thermoplastic resin particles.
【０００３】発泡性熱可塑性樹脂粒子製造の別法とし
て、スチレン系樹脂等の熱可塑性樹脂と発泡剤と無機質
粉末とを押出機中で溶融混練し、ダイスの出口から加圧
水中に押し出した後、粒子状に切断する溶融押出造粒法
（特公昭４２−２４０７２号公報）が知られており、こ
の方法は、粒度調整、粒子の着色および廃品の再生が容
易であるほか、無機質粉末の添加により押出工程でのス
リップが防止でき、しかも発泡セルが比較的均一で、外
観も改良された発泡性発泡性熱可塑性樹脂粒子が得られ
るという利点がある。As another method for producing expandable thermoplastic resin particles, a thermoplastic resin such as a styrene resin, a foaming agent and an inorganic powder are melt-kneaded in an extruder and extruded into pressurized water from an outlet of a die, A melt extrusion granulation method of cutting into particles (Japanese Patent Publication No. S42-24072) is known, and this method facilitates particle size adjustment, coloration of particles, and recycling of waste products, as well as addition of inorganic powder. There is an advantage that slippage in the extrusion process can be prevented, foamable expandable thermoplastic resin particles having a relatively uniform foam cell and an improved appearance can be obtained.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上記特
公昭４２−２４０７２号公報には、実施例において無機
質粉末を熱可塑性樹脂１００重量部に対して２重量部と
多量に使用しているため、ダイス孔より加圧水中に押し
出されて切断された粒子は、粒子内に内部発泡によるボ
イドが発生し、粒子表面より発泡剤が逸散するととも
に、粒子内部に水分を巻き込みやすくなる。このため、
発泡成形品においても、発泡倍率の低下、含水率の増大
を招き、強度も悪化してしまう危険性がある。However, in Japanese Patent Publication No. 4224072/1987, since the inorganic powder is used in a large amount of 2 parts by weight with respect to 100 parts by weight of the thermoplastic resin in the examples, the die is used. The particles that are extruded into the pressurized water through the holes and cut off generate voids due to internal foaming inside the particles, and the foaming agent dissipates from the surface of the particles, and it becomes easier for water to be trapped inside the particles. For this reason,
Even in a foam-molded product, there is a risk that the expansion ratio is reduced, the water content is increased, and the strength is deteriorated.
【０００５】[0005]
【課題を解決するための手段】本発明者等は、この様な
状況を解決するため、鋭意検討した結果、無機質粉末を
特定量以下の使用割合で添加すると、発泡剤が熱可塑性
樹脂中に容易に微分散するため、内部発泡によるボイド
の発生、粒子表面からの発泡剤の逸散、粒子内部への水
分を巻き込み等がなく、均一な発泡ができ、良好な予備
発泡粒子や発泡成形品が安定して得られる発泡性熱可塑
性樹脂粒子を容易に製造できることを見い出し、本発明
を完成するに至った。Means for Solving the Problems The inventors of the present invention have made diligent studies in order to solve such a situation. As a result, when an inorganic powder is added at a usage ratio of a specific amount or less, a foaming agent is added to a thermoplastic resin. Since it is easily finely dispersed, voids are generated due to internal foaming, there is no escape of the foaming agent from the particle surface, and water is not trapped inside the particles, and uniform foaming is possible. It was found that the expandable thermoplastic resin particles stably obtained can be easily produced, and the present invention has been completed.
【０００６】即ち、本発明は、熱可塑性樹脂（Ａ）と、
発泡剤（Ｂ）と、該熱可塑性樹脂（Ａ）１００重量部に
対して１．５重量部以下の無機質粉末（Ｃ）とを溶融混
練し、次いでこれをダイヘッドの押出孔から加圧液中に
押出し、即時切断した後、冷却することを特徴とする発
泡性熱可塑性樹脂粒子の製造法を提供するものである。That is, the present invention comprises a thermoplastic resin (A),
The blowing agent (B) and 1.5 parts by weight or less of the inorganic powder (C) are melt-kneaded with respect to 100 parts by weight of the thermoplastic resin (A), which is then extruded through a die head extrusion hole into a pressurized liquid. The present invention provides a method for producing expandable thermoplastic resin particles, which comprises extruding into a sheet, immediately cutting, and then cooling.
【０００７】本発明で用いる熱可塑性樹脂（Ａ）として
は、発泡剤により発泡可能な樹脂であればよく、例えば
ポリスチレン、スチレン−ブタジエン共重合体（耐衝撃
性ポリスチレン）、スチレン−（メタ）アクリル酸共重
合体、スチレン−無水マレイン酸共重合体、ＡＳ樹脂、
ＡＢＳ樹脂等の芳香族ビニル系樹脂、塩化ビニル樹脂、
塩化ビニリデン樹脂、塩化ビニル−酢酸ビニル共重合体
等の塩化ビニル系樹脂、ポリエチレン、ポリプロピレン
等のオレフィン系樹脂、ポリ（メタ）アクリル酸メチ
ル、ポリ（メタ）アクリル酸エチル、メタクリル酸メチ
ル−スチレン共重合体等のアクリル系樹脂、ポリエチレ
ンテレフタレート、ポリブチレンテレフタレート等のポ
リエステル系樹脂、ポリカプロラクタム、ヘキサメチレ
ンアジボアミド樹脂等のアミド系樹脂、ポリウレタン、
ポリカーボネート、ポリエーテルイミド、ポリフェニレ
ンエーテル等の単独あるいは混合物が挙げられ、なかで
も芳香族ビニル系樹脂、オレフィン系樹脂が好ましく、
特にスチレン系樹脂が好ましい。The thermoplastic resin (A) used in the present invention may be any resin which can be foamed by a foaming agent, and examples thereof include polystyrene, styrene-butadiene copolymer (impact-resistant polystyrene), and styrene- (meth) acrylic. Acid copolymer, styrene-maleic anhydride copolymer, AS resin,
Aromatic vinyl resin such as ABS resin, vinyl chloride resin,
Vinylidene chloride resin, vinyl chloride resin such as vinyl chloride-vinyl acetate copolymer, olefin resin such as polyethylene and polypropylene, poly (meth) acrylate, poly (meth) acrylate, methyl methacrylate-styrene copolymer Acrylic resins such as polymers, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, amide resins such as polycaprolactam and hexamethylene adibamide resin, polyurethane,
Polycarbonate, polyether imide, polyphenylene ether and the like may be mentioned alone or as a mixture, and among them, aromatic vinyl resins and olefin resins are preferable,
A styrene resin is particularly preferable.
【０００８】本発明で用いる発泡剤（Ｂ）としては、例
えば脂肪族炭化水素系発泡剤、ハロゲン化炭化水素系発
泡剤等が挙げられ、通常大気圧下での沸点が９５℃以下
のものを用いる。Examples of the foaming agent (B) used in the present invention include aliphatic hydrocarbon type foaming agents, halogenated hydrocarbon type foaming agents and the like, and those having a boiling point of 95 ° C. or less at atmospheric pressure are usually used. To use.
【０００９】上記脂肪族炭化水素系発泡剤としては、例
えばエタン、プロパン、プロピレン、ノルマルブタン、
イソブタン、イソブチレン、ノルマルペンタン、イソペ
ンタン、ネオペンタン、シクロペンタン、ヘキサン、石
油エーテル等が挙げられ、またハロゲン化炭化水素系発
泡剤としては、例えば塩化メチル、塩化エチル、ジクロ
ロエタン、クロロホルム、フルオロメタン、ジフルオロ
メタン、トリフルオロメタン、ジフルオロエタン、トリ
フルオロエタン、フルオロクロロメタン、フルオロクロ
ロエタン、ジクロロジフルオロメタン等が挙げられる。
なかでも炭素原子数３〜６の脂肪族炭化水素、特にノル
マルブタン、イソブタン、イソブチレン、ノルマルペン
タン、イソペンタンが好ましい。Examples of the above-mentioned aliphatic hydrocarbon type foaming agent include ethane, propane, propylene, normal butane,
Examples include isobutane, isobutylene, normal pentane, isopentane, neopentane, cyclopentane, hexane, petroleum ether, and the like.Halogenated hydrocarbon blowing agents include, for example, methyl chloride, ethyl chloride, dichloroethane, chloroform, fluoromethane, difluoromethane. , Trifluoromethane, difluoroethane, trifluoroethane, fluorochloromethane, fluorochloroethane, dichlorodifluoromethane and the like.
Among them, aliphatic hydrocarbons having 3 to 6 carbon atoms, particularly normal butane, isobutane, isobutylene, normal pentane and isopentane are preferable.
【００１０】発泡剤（Ｂ）の使用量は、熱可塑性樹脂
（Ａ）１００重量部に対して、通常４０重量部以下であ
り、なかでも粒子の凝集がなく、均一なセル径が得られ
る点で２〜１０重量部が好ましい。The amount of the foaming agent (B) used is usually 40 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin (A), and among them, particles do not aggregate and a uniform cell diameter can be obtained. 2 to 10 parts by weight is preferable.
【００１１】本発明で用いる無機質粉末（Ｃ）として
は、タルク、珪藻土、焼成パーライト、ベントナイト、
陶土、アスベスト、ガラス、石灰石、酸化アルミニウ
ム、炭酸マグネシウム、炭酸第二鉄等が挙げられ、これ
らは併用しても差し支えない。The inorganic powder (C) used in the present invention includes talc, diatomaceous earth, calcined perlite, bentonite,
Examples include clay, asbestos, glass, limestone, aluminum oxide, magnesium carbonate, ferric carbonate and the like, and these may be used in combination.
【００１２】また、無機質粉末（Ｃ）の添加量として
は、熱可塑性樹脂（Ａ）１００重量部に対して１．５重
量部以下であることが必須であり、なかでも０．００５
〜１．０重量部が望ましい。該添加量が１．５重量部よ
り多い場合には、得られる発泡性粒子内に内部発泡によ
るボイドが発生し、粒子表面より発泡剤が逸散するとと
もに、粒子内部に水分を巻き込みやすくなる。It is essential that the amount of the inorganic powder (C) added be 1.5 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin (A).
˜1.0 parts by weight is desirable. When the amount added is more than 1.5 parts by weight, voids are generated in the resulting expandable particles due to internal foaming, the foaming agent dissipates from the surface of the particles, and water is easily entrained inside the particles.
【００１３】本発明の製造法において、熱可塑性樹脂
（Ａ）と発泡剤（Ｂ）と無機質粉末（Ｃ）とを溶融混練
する方法としては、特に限定はなく、例えば該（Ａ）、
（Ｂ）及び（Ｃ）の３成分を溶融混練機を用いて（Ａ）
の溶融温度以上で溶融混練する方法が挙げられる。通常
は単軸押出機、二軸押出機、タンデム型押出機等の押出
機を用い、該（Ａ）、（Ｂ）及び（Ｃ）の３成分を溶融
混練した後、これをダイヘッドの押出孔から押し出す方
法が一般的であるが、なかでも発泡剤（Ｂ）及び無機質
粉末（Ｃ）の分散が良好な点で二軸押出機やタンデム型
押出機を用いると好ましい。また、発泡剤（Ｃ）は熱可
塑性樹脂（Ａ）が半溶融ないし溶融しているところ、例
えば押出機の途中の部分から圧入すると好ましい。In the production method of the present invention, the method of melt-kneading the thermoplastic resin (A), the foaming agent (B) and the inorganic powder (C) is not particularly limited, and examples thereof include (A),
Using the melt-kneader, the three components (B) and (C) are used (A).
Examples of the method include melt-kneading at a temperature equal to or higher than the melting temperature. Usually, an extruder such as a single-screw extruder, a twin-screw extruder, or a tandem extruder is used to melt and knead the three components (A), (B) and (C), and then to the extrusion holes of the die head. A method of extruding is generally used, but it is preferable to use a twin-screw extruder or a tandem type extruder because of good dispersion of the foaming agent (B) and the inorganic powder (C). Further, it is preferable that the foaming agent (C) is press-fitted, for example, from a portion in the middle of the extruder, where the thermoplastic resin (A) is semi-molten or molten.
【００１４】この様に溶融混練された発泡剤含有熱可塑
性樹脂は、通常溶融混練機の先に取り付けられたダイヘ
ッドの押出孔から、加圧液中に押し出した後、即時切断
して粒子とする。The foaming agent-containing thermoplastic resin thus melt-kneaded is extruded into the pressurized liquid from the extrusion hole of the die head usually attached to the tip of the melt-kneader, and then immediately cut into particles. .
【００１５】ここで用いるダイヘッドとしては、例えば
直径０．３〜３ｍｍ、好ましくは０．５〜１ｍｍの押出
孔を有するもの等が挙げられ、また切断装置としては、
押出孔から押し出された発泡剤含有熱可塑性樹脂を即時
高温状態で切断するカッターと加圧液とを内部に有する
カッターチャンバーとが取付けられているものが挙げら
れる。The die head used here includes, for example, one having an extrusion hole having a diameter of 0.3 to 3 mm, preferably 0.5 to 1 mm, and the cutting device is
An example is one in which a cutter for cutting the foaming agent-containing thermoplastic resin extruded from the extrusion hole immediately in a high temperature state and a cutter chamber having a pressurized liquid inside are attached.
【００１６】加圧液としては、上記粒子の発泡を防止可
能な圧力以上に加圧した水、グリコール、エチレングリ
コール、水とエチレングリコールの混合物等が挙げら
れ、通常加熱加圧された水を用いる。Examples of the pressurized liquid include water pressurized above the pressure capable of preventing foaming of the particles, glycol, ethylene glycol, a mixture of water and ethylene glycol, and usually water heated under pressure is used. .
【００１７】加圧液に加えられる圧力は、通常加圧液の
温度における発泡剤の飽和蒸気圧以上の圧力であり、カ
ッターチャンバーに加圧液を満たした場合で通常５ｋｇ
／ｃｍ2 以上、好ましくは１０〜２０ｋｇ／ｃｍ2 であ
る。The pressure applied to the pressurized liquid is usually equal to or higher than the saturated vapor pressure of the foaming agent at the temperature of the pressurized liquid, and usually 5 kg when the cutter chamber is filled with the pressurized liquid.
/ Cm 2 or more, preferably 10 to 20 kg / cm 2 .
【００１８】加圧液の温度は、特に限定されず、常温で
もよいが、切断して得られた発泡性熱可塑性樹脂粒子の
ガラス転移温度（以下、Ｔｇと略す）以上、特にＴｇか
ら加圧下での加圧液の沸点未満の間の温度であると、得
られた粒子が常温にまで急冷されないため、粒子内の残
留応力が緩和されて、より均一な発泡ができる粒子が得
られる様になり、好ましい。水を用いた場合の温度は、
通常４０〜１０５℃であり、なかでもスチレン系樹脂の
場合の温度は、６０〜８５℃が好ましい。The temperature of the pressurizing liquid is not particularly limited and may be room temperature, but it is not less than the glass transition temperature (hereinafter abbreviated as Tg) of the expandable thermoplastic resin particles obtained by cutting, especially under pressure from Tg. When the temperature is lower than the boiling point of the pressurized liquid in, the obtained particles are not rapidly cooled to room temperature, so that residual stress in the particles is relieved, and more uniform foaming can be obtained. It becomes, and it is preferable. The temperature when using water is
Usually, it is 40 to 105 ° C, and in particular, the temperature in the case of styrene resin is preferably 60 to 85 ° C.
【００１９】次いで粒子は、大気圧下でも発泡しなくな
る温度まで冷却してもよいが、直ちに冷却せずに加圧液
の中でＴｇ以上の温度に、通常２分間以上、好ましくは
４〜１０分間保持（必要に応じてＴｇ以上の温度内で温
度を上昇又は低下させてもよい。）あるいはＴｇ前後の
温度、好ましくはＴｇ±５度の温度範囲で徐冷して該粒
子内の残留応力の緩和を更に進めた後、冷却、好ましく
は平均毎分５℃以上の速度で急冷すると望ましい。冷却
された粒子は、次いで常圧下で分離、乾燥される。The particles may then be cooled to a temperature at which they will not foam even under atmospheric pressure, but they are not immediately cooled, but in a pressurized liquid, to a temperature of Tg or higher, usually for 2 minutes or longer, preferably 4-10. Residual stress in the particles is maintained for a minute (the temperature may be raised or lowered within a temperature of Tg or higher if necessary) or gradually cooled at a temperature around Tg, preferably within a temperature range of Tg ± 5 degrees. After further promoting the above relaxation, it is desirable to cool, preferably to quench rapidly at an average rate of 5 ° C. per minute or more. The cooled particles are then separated and dried under normal pressure.
【００２０】上記造粒後の粒子内の残留応力を緩和する
方法は、特に限定されないが、例えばカッターチャンバ
ーから出た発泡剤含有熱可塑性樹脂粒子を、加圧液と共
に応力緩和用加圧容器にその上部から供給し、Ｔｇ＋５
℃以上の温度以上に保持したまま、あるいはＴｇ前後の
温度、好ましくはＴｇ±５度の温度範囲で徐冷しつつ加
圧液中をゆっくり落下させて、粒子内の残留応力を緩和
させ、該容器の底部から順次抜き出す方法、カッターチ
ャンバーから出た発泡剤含有熱可塑性樹脂粒子を、加圧
液と共に移送管、例えば螺旋状の移送管に流入させ、こ
の管内をＴｇ＋５℃以上の温度以上に保持したまま、あ
るいはＴｇ前後の温度、好ましくはＴｇ±５度の温度範
囲で徐冷しつつ加圧液と共に移送させて、粒子内の残留
応力を緩和させる方法等が挙げられる。The method for relaxing the residual stress in the particles after granulation is not particularly limited, but for example, the foaming agent-containing thermoplastic resin particles discharged from the cutter chamber are put together with a pressurized liquid into a stress relaxation pressure container. Supply from above, Tg + 5
While being kept at a temperature of not less than ℃ or higher, or slowly cooled in a temperature range around Tg, preferably in a temperature range of Tg ± 5 degrees, the pressurized liquid is slowly dropped to relieve residual stress in the particles. A method of sequentially extracting from the bottom of the container, the blowing agent-containing thermoplastic resin particles discharged from the cutter chamber, together with the pressurized liquid, are allowed to flow into a transfer pipe, for example, a spiral transfer pipe, and the inside of this pipe is maintained at a temperature of Tg + 5 ° C or higher. As it is, or while it is slowly cooled at a temperature around Tg, preferably in a temperature range of Tg ± 5 ° C., it is transferred together with a pressurized liquid to relax the residual stress in the particles.
【００２１】また、粒子の冷却方法は、粒子の発泡を防
止しつつ冷却できる方法であればよく、例えば加圧下、
該粒子と加圧液、又は加圧液を分離した粒子に冷却液を
混合して冷却する方法等が挙げられる。The method for cooling the particles may be any method that can cool the particles while preventing them from foaming, for example, under pressure.
Examples thereof include a method in which a cooling liquid is mixed with the particles and the pressurized liquid, or particles obtained by separating the pressurized liquid, and cooled.
【００２２】[0022]
【実施例】以下に実施例および比較例を挙げて、本発明
を更に詳細に説明するが、本発明はこれにより限定され
るものではない。尚、例中の部および％は重量基準であ
る。EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The parts and% in the examples are based on weight.
【００２３】実施例１ ポリスチレン１００部とタルク０．０２部とからなる混
合物を第１段押出機と第２段押出機とからなるタンデム
型押出機のホッパーより供給して押出し、次いでブタン
７部を第一段押出機後半の注入口より供給し、第１段押
出機および第２段押出機でポリスチレンとブタンとを溶
融混練した。この時、樹脂温度は２００℃、樹脂圧力は
１１０ｋｇ／ｃｍ2 を示した。Example 1 A mixture of 100 parts of polystyrene and 0.02 part of talc was fed from a hopper of a tandem type extruder consisting of a first stage extruder and a second stage extruder and extruded, and then 7 parts of butane. Was supplied from the injection port in the latter half of the first-stage extruder, and polystyrene and butane were melt-kneaded by the first-stage extruder and the second-stage extruder. At this time, the resin temperature was 200 ° C. and the resin pressure was 110 kg / cm 2 .
【００２４】溶融混練した樹脂を、第二段押出機のダイ
ヘッド（押出孔０．７ｍｍφ×１００個）を通して、８
０℃、１０ｋｇ／ｃｍ2 の加圧水で満たされたカッター
チャンバーの中に８０ｋｇ／ｈｒの割合で押出し、直ち
にカッターで水中カットして、０．９ｍｍ径の粒子を得
た。The melt-kneaded resin was passed through a die head (extrusion hole 0.7 mmφ × 100 pieces) of a second stage extruder to obtain 8
It was extruded at a rate of 80 kg / hr into a cutter chamber filled with pressurized water of 0 ° C. and 10 kg / cm 2 , and immediately cut in water with a cutter to obtain particles having a diameter of 0.9 mm.
【００２５】この粒子を６ｍ3 ／ｈｒの加圧水が循環
し、８０℃、１０Ｋｇ／ｃｍ2 に保持された５００リッ
トルの応力緩和用加圧容器中に移送し、５分間滞留させ
て粒子の残留応力を緩和させた後、冷却用加圧容器に移
送して２５℃まで冷却し、減圧後、粒子を系外へ取り出
し、遠心脱水機で脱水し、乾燥して、発泡性ポリスチレ
ン粒子の原粒を得た。The particles were transferred into a 500 liter stress relaxation pressure vessel held at 80 ° C. and 10 Kg / cm 2 by circulating 6 m 3 / hr of pressurized water and retained for 5 minutes to give residual stress of the particles. After relaxing, the mixture was transferred to a pressure vessel for cooling, cooled to 25 ° C., decompressed, taken out of the system, dehydrated by a centrifugal dehydrator, and dried to obtain the original particles of expandable polystyrene particles. Obtained.
【００２６】こうして得られた粒子のブタン含有量は
５．５重量部であり、残留応力も少なく、粒子の含水率
も０．０１％と低く、予備発泡することにより７０ｃｃ
／ｇまで発泡し、発泡粒子のセル径も１５０〜２００μ
ｍと均一であった。The butane content of the particles thus obtained was 5.5 parts by weight, the residual stress was small, the water content of the particles was as low as 0.01%, and 70 cc was obtained by prefoaming.
/ G, and the cell diameter of the expanded particles is 150-200μ
m was uniform.
【００２７】この発泡性ポリスチレン粒子の組成と製造
条件と性状を表１に示す。尚、性状は以下の方法で測定
又は評価した。 ・粒子の含水率 ：トルエンに発泡性ポリスチレ
ン粒子５重量部を溶かし、 カ
ールフィッシャー水分計により測定した。 ・粒子の発泡剤含有量 ：ガスクロマトグラフィーにて
測定した。 ・粒子の平均粒子径 ：１００個の発泡性ポリスチレ
ン粒子の粒子径をダイヤルゲージで測定し、その平均値
を求めた。 ・粒子の残留応力 ：発泡性ポリスチレン粒子の表
面を５０倍の超音波顕微鏡写真にとり、その表面の縞模
様の程度から目視にて残留応力の多少を判定評価した。 ・粒子のＴｇ ：示差熱分析装置（ＤＳＣ）に
て測定した。 ・発泡倍率(１／嵩密度)：ゲージ圧１ｋｇ／ｃｍ2 のス
チームで３０秒間加熱して発泡させた発泡粒子の嵩密度
を求め、その逆数として算出した。 ・発泡粒子のセル径 ：上記と同様に発泡させた発泡
粒子１０個の切断面を５０倍の実体顕微鏡写真にとり、
そのセルの径を測定し、 範囲
を求めた。 ・発泡粒子セルの均一性：上記と同様にして５０倍の実
体顕微鏡写真にとり、セルの均一性を目視にて判定評価
した。 ・成形品外観 ：目視により判定した。Table 1 shows the composition, production conditions and properties of the expandable polystyrene particles. The properties were measured or evaluated by the following methods. Water content of particles: 5 parts by weight of expandable polystyrene particles were dissolved in toluene, and the content was measured by a Karl Fischer moisture meter. -Foaming agent content of particles: Measured by gas chromatography. -Average particle diameter of particles: The particle diameter of 100 expandable polystyrene particles was measured with a dial gauge, and the average value was obtained. -Residual stress of particles: The surface of expandable polystyrene particles was photographed with a 50 times ultrasonic microscope, and the residual stress was visually evaluated based on the degree of the striped pattern on the surface. -Tg of particles: measured with a differential thermal analyzer (DSC). -Expansion ratio (1 / bulk density): The bulk density of foamed particles foamed by heating for 30 seconds with steam having a gauge pressure of 1 kg / cm 2 was calculated and calculated as the reciprocal thereof. -Cell diameter of foamed particles: A cut surface of 10 foamed particles foamed in the same manner as above is taken on a stereoscopic micrograph of 50 times,
The diameter of the cell was measured and the range was determined. -Uniformity of foamed particle cell: A stereomicrograph of 50 times was taken in the same manner as above, and the uniformity of the cell was visually evaluated and evaluated. -Appearance of molded product: visually determined.
【００２８】◎：優れている。 ○：良好。 △：あまり良くない。⊚: Excellent. ◯: Good. Δ: Not very good
【００２９】×：不良。 比較例１ 押出機のホッパーより、ポリスチレンのみを供給し、タ
ルクを用いずに押し出した以外は実施例１と同様にし
て、発泡性ポリスチレン粒子を得た。X: Bad Comparative Example 1 Expandable polystyrene particles were obtained in the same manner as in Example 1 except that only polystyrene was supplied from the hopper of the extruder and extrusion was performed without using talc.
【００３０】こうして得られた粒子は、粒子内のブタン
の微分散性が悪く、予備発泡することにより６５ｃｃ／
ｇまで発泡したが、発泡粒子のセル径は１００〜３００
μｍとやや不均一であった。The particles thus obtained have a poor fine dispersibility of butane in the particles and are pre-expanded to 65 cc /
Although foamed to g, the cell diameter of the expanded particles is 100 to 300.
It was slightly uneven as μm.
【００３１】この発泡性ポリスチレン粒子の組成と製造
条件と性状を表１に示す。 比較例２ タルクの使用量を２．０部に変更した使用した以外は実
施例１と同様にして、発泡性ポリスチレン粒子を得た。Table 1 shows the composition, production conditions and properties of the expandable polystyrene particles. Comparative Example 2 Expandable polystyrene particles were obtained in the same manner as in Example 1 except that the amount of talc used was changed to 2.0 parts.
【００３２】こうして得られた粒子の発泡粒子のセル径
は１００〜２５０μｍと比較例１よりも均一化し、成形
品外観も良化したが、実施例１と比較すると、粒子の含
水量が多く、発泡倍率、セル径の均一性、成形品外観に
おいて見劣りする結果となった。また、粒子自体に多数
の気泡があり、内部発泡を起こしているものが多かっ
た。The expanded particles of the particles thus obtained had a cell diameter of 100 to 250 μm, which was more uniform than that of Comparative Example 1 and the appearance of the molded article was improved. However, compared with Example 1, the water content of the particles was large, The results were inferior in terms of expansion ratio, uniformity of cell diameter, and appearance of the molded product. In addition, the particles themselves had a large number of bubbles, and many of them caused internal foaming.
【００３３】この発泡性ポリスチレン粒子の組成と製造
条件と性状を表１に示す。 比較例３ タルクの使用量を３．０部に変更した以外は実施例１と
同様にして、発泡性ポリスチレン粒子を得た。Table 1 shows the composition, production conditions and properties of the expandable polystyrene particles. Comparative Example 3 Expandable polystyrene particles were obtained in the same manner as in Example 1 except that the amount of talc used was changed to 3.0 parts.
【００３４】こうして得られた粒子は、粒子がやや発泡
しており、粒子の含水量が２．０部と非常に多く、発泡
剤の含有量は４．０部で、発泡倍率も５０ｃｃ／ｇまで
しか上がらなかった。また、発泡粒子のセル径は４０〜
３００μｍと非常に不均一なものであり、成形品外観も
悪いものしか得られなかった。The particles thus obtained are slightly foamed, the water content of the particles is as high as 2.0 parts, the content of the foaming agent is 4.0 parts, and the expansion ratio is 50 cc / g. It only went up. The cell diameter of the expanded particles is 40 to
It was very uneven as 300 μm, and only the appearance of the molded product was poor.
【００３５】この発泡性ポリスチレン粒子の組成と製造
条件と性状を表１に示す。Table 1 shows the composition, production conditions and properties of the expandable polystyrene particles.
【００３６】[0036]
【表１】 [Table 1]
【００３７】実施例２〜４ 表２に示す組成と製造条件で行なった以外は実施例１と
同様にして各種の発泡性熱可塑性樹脂粒子を製造した。
その性状をまとめて表３に示す。Examples 2 to 4 Various expandable thermoplastic resin particles were produced in the same manner as in Example 1 except that the composition and production conditions shown in Table 2 were used.
The properties are summarized in Table 3.
【００３８】[0038]
【表２】 [Table 2]
【００３９】[0039]
【表３】 [Table 3]
【００４０】[0040]
【発明の効果】本発明の発泡性熱可塑性樹脂粒子の製法
によれば、発泡剤が熱可塑性樹脂中に容易に微分散する
ため、内部発泡によるボイドの発生、粒子表面からの発
泡剤の逸散、粒子内部への水分を巻き込み等がなく、均
一な発泡ができ、良好な予備発泡粒子や発泡成形品が安
定して得られる発泡性熱可塑性樹脂粒子を容易に製造で
きる。According to the process for producing expandable thermoplastic resin particles of the present invention, since the foaming agent is easily finely dispersed in the thermoplastic resin, voids are generated by internal foaming and the foaming agent escapes from the particle surface. It is possible to easily produce the pre-expanded thermoplastic resin particles and the pre-expanded thermoplastic resin particles, which are capable of being uniformly foamed without causing dispersion or entrapment of water in the inside of the particles and stably obtaining good pre-expanded plastic particles.
Claims (5)
と、該熱可塑性樹脂（Ａ）１００重量部に対して１．５
重量部以下の無機質粉末（Ｃ）とを溶融混練し、次いで
これをダイヘッドの押出孔から加圧液中に押出し、即時
切断した後、冷却することを特徴とする発泡性熱可塑性
樹脂粒子の製造法。1. A thermoplastic resin (A) and a foaming agent (B).
And 1.5 with respect to 100 parts by weight of the thermoplastic resin (A)
Manufacture of expandable thermoplastic resin particles characterized by melt-kneading parts by weight or less of an inorganic powder (C), then extruding the mixture into a pressurized liquid from an extrusion hole of a die head, cutting immediately, and then cooling. Law.
脂であり、かつ発泡剤（Ｂ）が常温常圧下で気体となる
ものである請求項１記載の製造法。2. The production method according to claim 1, wherein the thermoplastic resin (A) is an aromatic vinyl-based resin, and the foaming agent (B) becomes a gas under normal temperature and normal pressure.
あり、かつ発泡剤（Ｂ）が大気圧下での沸点が９５℃以
下ものである請求項１記載の製造法。3. The method according to claim 1, wherein the thermoplastic resin (A) is a styrene resin and the foaming agent (B) has a boiling point of 95 ° C. or less under atmospheric pressure.
樹脂（Ａ）１００重量部に対して０．００５〜１．０重
量部である請求項２又は３記載の製造法。4. The method according to claim 2, wherein the amount of the inorganic powder (C) used is 0.005 to 1.0 part by weight based on 100 parts by weight of the thermoplastic resin (A).
と、無機質粉末（Ｃ）とを溶融混練し、次いでこれをダ
イヘッドの押出孔から発泡性熱可塑性樹脂粒子のガラス
転移温度（以下、Ｔｇと略す）＋５℃以上の加熱加圧液
中に押出し、即時切断して得た粒子を、加熱加圧液中で
徐冷するか、又は同温度以上に保持した後、冷却する請
求項１〜４のいずれか１つに記載の製造法。5. A thermoplastic resin (A) and a foaming agent (B)
And an inorganic powder (C) are melt-kneaded, and then extruded through a die head extrusion hole into a glass transition temperature (hereinafter abbreviated as Tg) of the expandable thermoplastic resin particles + 5 ° C. or higher in a heated and pressurized liquid, The production method according to any one of claims 1 to 4, wherein particles obtained by immediate cutting are gradually cooled in a heated and pressurized liquid, or are held at the same temperature or higher and then cooled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5089848A JPH06298983A (en) | 1993-04-16 | 1993-04-16 | Production of expandable thermoplastic resin particle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5089848A JPH06298983A (en) | 1993-04-16 | 1993-04-16 | Production of expandable thermoplastic resin particle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06298983A true JPH06298983A (en) | 1994-10-25 |
Family
ID=13982200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5089848A Pending JPH06298983A (en) | 1993-04-16 | 1993-04-16 | Production of expandable thermoplastic resin particle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06298983A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0921148A1 (en) * | 1997-12-08 | 1999-06-09 | Dow Deutschland Inc. | Low density strand foams |
| US7776244B2 (en) | 2002-06-14 | 2010-08-17 | Basf Aktiengesellschaft | Method for producing expandable polystyrene |
| JP2012077114A (en) * | 2010-09-30 | 2012-04-19 | Sekisui Plastics Co Ltd | Expandable polystyrene resin particle, method for producing the same, polystyrene resin pre-expanded particle and polystyrene resin foam-molded product |
| JP2012167267A (en) * | 2011-01-26 | 2012-09-06 | Sekisui Plastics Co Ltd | Foamable polystyrene-based resin particle and method for producing the same and foam molded product |
| DE112007003709B4 (en) * | 2007-11-21 | 2013-08-22 | Hyundai Engineering Plastics Co., Ltd. | Expandable polystyrene beads with platelet-shaped talc coated with resin and process for their preparation |
| DE19819058C5 (en) * | 1998-04-29 | 2015-06-25 | Basf Se | Process for the production of prefoamed EPS particles with coarse foam structure from particulate, slightly foamed, expanded styrene polymers |
| JP2019163426A (en) * | 2018-03-20 | 2019-09-26 | 株式会社カネカ | Process for producing polypropylene-based resin expanded particle |
-
1993
- 1993-04-16 JP JP5089848A patent/JPH06298983A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0921148A1 (en) * | 1997-12-08 | 1999-06-09 | Dow Deutschland Inc. | Low density strand foams |
| WO1999029765A1 (en) * | 1997-12-08 | 1999-06-17 | The Dow Chemical Company | Low density strand foams |
| DE19819058C5 (en) * | 1998-04-29 | 2015-06-25 | Basf Se | Process for the production of prefoamed EPS particles with coarse foam structure from particulate, slightly foamed, expanded styrene polymers |
| US7776244B2 (en) | 2002-06-14 | 2010-08-17 | Basf Aktiengesellschaft | Method for producing expandable polystyrene |
| DE112007003709B4 (en) * | 2007-11-21 | 2013-08-22 | Hyundai Engineering Plastics Co., Ltd. | Expandable polystyrene beads with platelet-shaped talc coated with resin and process for their preparation |
| JP2012077114A (en) * | 2010-09-30 | 2012-04-19 | Sekisui Plastics Co Ltd | Expandable polystyrene resin particle, method for producing the same, polystyrene resin pre-expanded particle and polystyrene resin foam-molded product |
| JP2012167267A (en) * | 2011-01-26 | 2012-09-06 | Sekisui Plastics Co Ltd | Foamable polystyrene-based resin particle and method for producing the same and foam molded product |
| JP2019163426A (en) * | 2018-03-20 | 2019-09-26 | 株式会社カネカ | Process for producing polypropylene-based resin expanded particle |
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