JPH05200835A - Manufacture of low formable polystyrene resin sheet - Google Patents

Manufacture of low formable polystyrene resin sheet

Info

Publication number
JPH05200835A
JPH05200835A JP4032712A JP3271292A JPH05200835A JP H05200835 A JPH05200835 A JP H05200835A JP 4032712 A JP4032712 A JP 4032712A JP 3271292 A JP3271292 A JP 3271292A JP H05200835 A JPH05200835 A JP H05200835A
Authority
JP
Japan
Prior art keywords
pressure
melt
extruder
gear pump
polystyrene
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
Application number
JP4032712A
Other languages
Japanese (ja)
Inventor
Yoshiaki Momose
義昭 百瀬
Hideto Nakatsuka
英人 中塚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JSP Corp
Original Assignee
JSP Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by JSP Corp filed Critical JSP Corp
Priority to JP4032712A priority Critical patent/JPH05200835A/en
Publication of JPH05200835A publication Critical patent/JPH05200835A/en
Pending legal-status Critical Current

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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/365—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using pumps, e.g. piston pumps
    • B29C48/37—Gear pumps
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. films
    • 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
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92685—Density, e.g. per unit length or area
    • 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
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92704—Temperature

Abstract

PURPOSE:To provide the process which produces in excellent productivity the low formable polystyrene resin sheet with the magnifying power of expansion of about 1.5-7 and high quality. CONSTITUTION:After polystyrene resin and foaming agent have been kneaded in molten state in an extruding machine, the obtained molten and kneaded material is caused to pass through a gear pump, and then the molten and kneaded material is extruded from a die. The pressure of the molten and kneaded material at the inlet of the gear pump is kept at most 120kgf/cm<2>G.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、熱成形性が良く断熱性
や強度の点でも高発泡品や無発泡品より利点の多い、低
発泡ポリスチレン系樹脂シートの製造方法に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low-foaming polystyrene resin sheet, which has good thermoformability and is more advantageous in terms of heat insulation and strength than highly foamed or non-foamed products.

【０００２】[0002]

【従来技術及びその問題点】低発泡ポリスチレン系樹脂
シート（以下、ＬＦＰＳシートとも略記する）は、熱成
形性が良いためコップやドンブリのような深い容器、あ
るいは形状の複雑な容器の成形が容易なうえ、発泡体な
ので高い断熱性を持つと共に低発泡なので強度も大き
い。また、強度が大きいから高発泡体より厚みのうすい
容器でも充分使用可能となり、環境面や物流面でも利点
が多い。ところで、発泡倍率が８倍以下、特に１．５〜
７倍程度というＬＦＰＳシートの製造は、高発泡のもの
よりも技術的にむつかしく、高品質の製品を得ることは
困難である。品質の良いＬＦＰＳシートを製造するため
には、樹脂発泡時においては、発泡剤ガス圧によりセル
が成長する過程でセル膜が破損することなく十分に延伸
するように、発泡温度を十分に低く保持する必要があ
る。一方、樹脂に対する発泡剤混入時においては、十分
に低い溶融樹脂粘度が得られ、発泡剤と樹脂との均質混
合物が得られるように、十分に高い温度に保持すること
が必要となる。ＬＦＰＳシートの製造では、発泡剤の樹
脂に対する使用割合が小さいことから、発泡剤の混入に
よる溶融樹脂粘度の低下効果が小さいことから、樹脂と
発泡剤との均質混合を行うには、高発泡ポリスチレン系
樹脂シートを製造する場合よりもかなり高い温度に保持
することが必要になる。ＬＦＰＳシートの製造に際して
要求される前記条件はいずれも相反するもので、高発泡
ポリスチレン系樹脂シートの製造に用いられているよう
な押出機を用いるだけでは高品質のＬＦＰＳシートを得
ることはできない。特開平１−３０１３１８号公報によ
れば、押出機とダイスとの間の樹脂通路に、ヘリカルギ
ヤーポンプを配置した押出成形機を用いてスチレン系樹
脂成形品を得る方法が提案されている。この公知方法
は、ヘリカルギヤーポンプの使用により、押出機内での
樹脂圧力及び温度を高めることなくダイスからの樹脂吐
出量を向上させるとともに、肉厚の均一な成形品を得よ
うとするもので、発泡倍率が１．５〜７倍程度の低発泡
品の製造を目的とするものではない。また、前記公報に
はそのような低発泡品を得るための具体的条件につい
て、これを示唆する記載もない。2. Description of the Related Art A low-foam polystyrene resin sheet (hereinafter also abbreviated as LFPS sheet) has good thermoformability, so that it is easy to form a deep container such as a cup or donburi or a container having a complicated shape. Moreover, since it is a foam, it has high heat insulation, and because it is a low foam, it has high strength. Further, since it has a high strength, it can be sufficiently used in a thin container having a thickness larger than that of a high-foam material, which has many advantages in terms of environment and distribution. By the way, the expansion ratio is 8 times or less, especially 1.5 to
It is technically more difficult to manufacture a LFPS sheet of about 7 times than that of a highly foamed product, and it is difficult to obtain a high quality product. In order to produce a good quality LFPS sheet, keep the foaming temperature low enough during resin foaming so that the cell film stretches sufficiently without being damaged during the cell growth due to the foaming agent gas pressure. There is a need to. On the other hand, when the foaming agent is mixed with the resin, it is necessary to maintain the temperature sufficiently high so that a sufficiently low melted resin viscosity is obtained and a homogeneous mixture of the foaming agent and the resin is obtained. In the production of the LFPS sheet, since the use ratio of the foaming agent to the resin is small, the effect of decreasing the viscosity of the molten resin due to the mixing of the foaming agent is small. It is necessary to maintain the temperature at a temperature considerably higher than that when manufacturing the resin sheet. The above-mentioned conditions required for manufacturing the LFPS sheet are contradictory to each other, and it is not possible to obtain a high-quality LFPS sheet only by using the extruder used for manufacturing the highly expanded polystyrene resin sheet. Japanese Patent Laid-Open No. 1-301318 proposes a method of obtaining a styrene-based resin molded product by using an extrusion molding machine in which a helical gear pump is arranged in a resin passage between an extruder and a die. In this known method, by using a helical gear pump, the amount of resin discharged from the die is improved without increasing the resin pressure and temperature in the extruder, and a molded product having a uniform wall thickness is obtained. It is not intended to produce a low-foam product having a magnification of about 1.5 to 7 times. Further, there is no description in the above publication suggesting specific conditions for obtaining such a low-foamed product.

【０００３】[0003]

【発明が解決しようとする課題】本発明は、発泡倍率が
１．５〜７倍程度で高品質の低発泡ポリスチレン系樹脂
シートを生産性良く製造する方法を提供することをその
課題としている。SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a high quality low expanded polystyrene resin sheet with a high expansion ratio of about 1.5 to 7 with high productivity.

【０００４】[0004]

【課題を解決するための手段】本発明者らは、前記課題
を解決すべく鋭意検討を重ね本発明を完成するに至っ
た。すなわち、本発明によれば、ポリスチレン系樹脂と
発泡剤とを押出機内で溶融混練した後、得られた溶融混
練物をギヤーポンプを通過させ、次いでダイスより溶融
混練物を押出して低発泡ポリスチレン系樹脂シートを製
造する方法であって、上記溶融混練物のギヤーポンプ入
口部における圧力を１２０ｋｇｆ／ｃｍ2Ｇ以下とする
ことを特徴とする低発泡ポリスチレン系樹脂シートの製
造方法が提供される。また、本発明によれば、ＭＦＲが
０．５〜１０ｇ／１０分のポリスチレンと、タルクを含
有するポリスチレンとを、タルクがポリスチレンと発泡
剤とタルクとの総和に対して０．１〜３重量％の割合と
なるように押出機内に入れ、押出機内での溶融ポリスチ
レンの圧力及び温度をそれぞれ１５０〜３００ｋｇｆ／
ｃｍ2Ｇ及び１５０〜２５０℃となるようにポリスチレ
ンを溶融混合した後、押出機の途中の発泡剤注入口より
溶融混練物中０．０１〜２重量％の割合になるようにｎ
−ブタンまたは／及びｉｓｏ−ブタンを圧入し、これら
混合物を溶融混練しながら冷却しつつ移送して押出機先
端での溶融混練物の圧力及び温度をそれぞれ５０〜１５
０ｋｇｆ／ｃｍ2Ｇ及び１４０〜１７０℃とし、得られ
た溶融混練物を圧力３０〜１１０ｋｇｆ／ｃｍ2Ｇでヘ
リカルギヤーポンプの入口部に導き、次いでギヤーポン
プ出口部の溶融混練物の圧力を入口部の圧力の１．６〜
５倍となるようにギヤーポンプ内で溶融混練物を昇圧し
つつ通過させ、続いてこれをダイスに導き、ダイス内で
の圧力及び温度をそれぞれ１５０〜２５０ｋｇｆ／ｃｍ
2Ｇ及び１３５℃以上１８５℃未満とし、その後これら
を筒状に押出発泡させ、押出方向の一端より切り開いて
密度０．１５〜０．７ｇ／ｃｍ3、厚み０．３〜３ｍｍ
の実質的に独立気泡の低発泡ポリスチレン樹脂シートと
し、その後該シートをロール状に巻き取ることを特徴と
する真空成形または／及び圧空成形等の成形性に優れた
低発泡ポリスチレン系樹脂シートの製造方法が提供され
る。Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems and completed the present invention. That is, according to the present invention, after the polystyrene-based resin and the foaming agent are melt-kneaded in the extruder, the resulting melt-kneaded product is passed through a gear pump, and then the melt-kneaded product is extruded from a die to produce a low-foaming polystyrene-based resin. A method for producing a low-expanded polystyrene-based resin sheet, characterized in that the pressure at the gear pump inlet of the melt-kneaded product is 120 kgf / cm 2 G or less. Further, according to the present invention, polystyrene having an MFR of 0.5 to 10 g / 10 min and polystyrene containing talc are contained in an amount of 0.1 to 3% by weight based on the total amount of polystyrene, a foaming agent and talc. % So that the pressure and temperature of the molten polystyrene in the extruder are 150 to 300 kgf /
cm 2 G and 150 to 250 ° C. were melt-mixed with polystyrene, and n was adjusted so that the content was 0.01 to 2 wt% in the melt-kneaded product through the blowing agent injection port in the middle of the extruder.
-Butane or / and iso-butane are pressed in, and the mixture is melted and kneaded and transferred while being cooled, and the pressure and temperature of the melted and kneaded material at the tip of the extruder are 50 to 15 respectively.
0 kgf / cm 2 G and 140 to 170 ° C., the obtained melt-kneaded product was introduced to the inlet of the helical gear pump at a pressure of 30 to 110 kgf / cm 2 G, and then the pressure of the melt-kneaded product at the gear pump outlet was adjusted to the inlet. Pressure of 1.6 ~
The melted and kneaded material is passed through the gear pump while pressurizing so that the pressure becomes 5 times, and then this is introduced into a die, and the pressure and temperature in the die are respectively 150 to 250 kgf / cm.
2 G and 135 ° C. or higher and lower than 185 ° C., and then these are extruded and foamed into a tubular shape, cut open from one end in the extrusion direction and have a density of 0.15 to 0.7 g / cm 3 and a thickness of 0.3 to 3 mm.
Of a low-expanded polystyrene resin sheet having substantially closed cells, which is then wound into a roll, and which is excellent in moldability such as vacuum forming and / or pressure forming and the like. A method is provided.

【０００５】本発明で用いるポリスチレン系樹脂として
は、スチレンの単独重合体及び共重合体が包含される。
スチレン共重合体としては、スチレン／ブタジエン共重
合体、スチレン／ブタジエン／アクリロニトリル共重合
体、スチレン／アクリル酸共重合体、スチレン／メタク
リル酸共重合体、スチレン／無水マレイン酸共重合体、
スチレン／エチレン共重合体、スチレン／塩化ビニル共
重合体等が挙げられる。本発明で用いる好ましいポリス
チレン系樹脂は、そのメルトフローレート（ＭＦＲ）が
０．１〜３５ｇ／１０分、好ましくは、０．５〜３０ｇ
／１０分のものである。The polystyrene resins used in the present invention include styrene homopolymers and copolymers.
Examples of the styrene copolymer include styrene / butadiene copolymer, styrene / butadiene / acrylonitrile copolymer, styrene / acrylic acid copolymer, styrene / methacrylic acid copolymer, styrene / maleic anhydride copolymer,
Examples thereof include styrene / ethylene copolymers and styrene / vinyl chloride copolymers. The preferred polystyrene resin used in the present invention has a melt flow rate (MFR) of 0.1 to 35 g / 10 minutes, preferably 0.5 to 30 g.
/ 10 minutes.

【０００６】本発明で用いるポリスチレン系樹脂には、
必要に応じ、慣用の補助成分、例えば、気泡調整剤のほ
か、顔料、高級脂肪酸の金属塩等を添加することができ
る。気泡調整剤は発泡体のセル径を均一に調整するのに
有効であり、基材樹脂と各種添加剤と発泡剤との総量に
対し、その０．１〜３．０重量％程度添加すれば良い。
気泡調整剤としては、例えば、タルク、炭酸マグネシウ
ム、パーライト、硅酸カルシウム、炭酸カルシウム、酸
化硅素、バライタ、バーミキュライト、硼酸等の無機薬
品、あるいはクエン酸、酒石酸、蓚酸等が挙げられる。
高級脂肪酸の金属塩は、発泡体シートの柔軟性向上や押
出し成形時の加工性向上に有効であり、同様に０〜１．
０重量％程度添加すれば良い。高級脂肪酸金属塩として
は、炭素数１２〜２２の高級脂肪酸、例えばカプリン
酸、ステアリン酸、パルミチン酸等のカルシウム塩、ナ
トリウム塩、カリウム塩、リチウム塩、亜鉛塩、アルミ
ニウム塩等が挙げられるが、特にステアリン酸亜鉛、ス
テアリン酸アルミニウム、及びステアリン酸カルウシム
が好適である。着色剤として使用する顔料添加量も同様
に０〜１５重量％程度である。The polystyrene resin used in the present invention includes
If necessary, a conventional auxiliary component, for example, a cell regulator, a pigment, a metal salt of a higher fatty acid, or the like can be added. The cell regulator is effective in uniformly adjusting the cell diameter of the foam, and if it is added in an amount of about 0.1 to 3.0% by weight based on the total amount of the base resin, various additives and the foaming agent. good.
Examples of the air bubble modifier include talc, magnesium carbonate, perlite, calcium silicate, calcium carbonate, silicon oxide, baryta, vermiculite, inorganic chemicals such as boric acid, citric acid, tartaric acid, oxalic acid and the like.
The metal salt of a higher fatty acid is effective in improving the flexibility of the foam sheet and the processability at the time of extrusion molding.
It is sufficient to add about 0% by weight. Examples of the higher fatty acid metal salt include higher fatty acids having 12 to 22 carbon atoms, for example, calcium salts such as capric acid, stearic acid and palmitic acid, sodium salts, potassium salts, lithium salts, zinc salts, aluminum salts, and the like. Zinc stearate, aluminum stearate, and calcium stearate are particularly preferred. Similarly, the amount of pigment used as a colorant is about 0 to 15% by weight.

【０００７】本発明法において用いる有機系発泡剤は、
発泡のほか基材樹脂の溶融粘度低下にも大きく寄与する
重要な添加剤である。このような有機系発泡剤として
は、例えば、プロパン、ｎ−ブタン、ｉｓｏ−ブタン、
ｎ−ペタン、ｉｓｏ−ペタン、ｎ−ヘキサン、ｉｓｏ−
ヘキサン、シクロヘキサン、クロロジフロロメタン、
１，１，１−トリフロロ−２，２−ジクロロエタン、
１，１，１，２−テトラフロロエタン、１，１−ジクロ
ロ−１−クロロエタン、１，１−ジフロロエタン、１，
１，１，２−テトラフロロ−２−クロロエタン及び１，
１−ジクロロ−１−フロロエタンが用いられる。本発明
においては、この発泡剤の添加量は、基材樹脂と各種添
加剤との総和に対して、５重量％、好ましくは０．０１
〜２重量％の割合で用いる。この発泡剤添加量が前記範
囲を超えると、本発明で目的とする低発泡品を得ること
が困難になり、一方、前記範囲より小さいと、溶融樹脂
を粘度低下させる効果が不十分になり、発泡剤と樹脂と
の均一混合が困難になる。The organic blowing agent used in the method of the present invention is
In addition to foaming, it is an important additive that greatly contributes to lowering the melt viscosity of the base resin. Examples of such an organic foaming agent include propane, n-butane, iso-butane,
n-Petane, iso-Petane, n-Hexane, iso-
Hexane, cyclohexane, chlorodifluoromethane,
1,1,1-trifluoro-2,2-dichloroethane,
1,1,1,2-tetrafluoroethane, 1,1-dichloro-1-chloroethane, 1,1-difluoroethane, 1,
1,1,2-tetrafluoro-2-chloroethane and 1,
1-Dichloro-1-fluoroethane is used. In the present invention, the amount of the foaming agent added is 5% by weight, preferably 0.01%, based on the total amount of the base resin and various additives.
It is used in a proportion of up to 2% by weight. When the amount of the foaming agent added exceeds the above range, it becomes difficult to obtain the low-foamed product targeted by the present invention, while when it is less than the range, the effect of lowering the viscosity of the molten resin becomes insufficient, It becomes difficult to uniformly mix the foaming agent and the resin.

【０００８】本発明のＬＦＰＳシートの製造方法は、押
出機とダイスとの間にギヤーポンプを介在させた装置を
用いて実施される。押出機としては、従来慣用されてい
る筒型押出機で、その前部に配置された原料供給口とそ
の供給口の後部に配置された発泡剤導入口を有するもの
が用いられる。ギヤーポンプとしては、ヘリカルギヤー
ポンプが用いられる。本発明の方法を実施するには、押
出機原料供給口から原料樹脂を供給するとともに、発泡
剤導入口から所定の発泡剤を導入する。押出機内の溶融
ポリスチレン系樹脂の温度は、原料樹脂が溶融する温度
に保持されるが、その温度は、原料供給口から発泡剤導
入口までの樹脂溶融部の温度が最も高く、通常、１５０
〜２５０℃に保持され、発泡剤導入口から押出機先端部
に向って内部温度は徐々に降下し、押出機先端部での溶
融混練物の温度（押出機出口温度）は１４０〜１７０℃
に保持される。また、押出機内部圧力も発泡剤導入口か
ら押出機先端部に向って徐々に降下する。押出機の発泡
剤導入口での溶融ポリスチレン系樹脂の圧力は、１５０
〜３００ｋｇｆ／ｃｍ2Ｇであるが、押出機先端部での
溶融混練物の圧力（押出機出口圧）は５０〜１５０ｋｇ
ｆ／ｃｍ2Ｇである。The LFPS sheet manufacturing method of the present invention is carried out using an apparatus in which a gear pump is interposed between an extruder and a die. As the extruder, a conventionally used tubular extruder having a raw material supply port arranged in the front part thereof and a foaming agent introducing port arranged in the rear part of the supply port is used. A helical gear pump is used as the gear pump. To carry out the method of the present invention, the raw material resin is supplied from the extruder raw material supply port, and a predetermined foaming agent is introduced from the foaming agent introduction port. The temperature of the molten polystyrene-based resin in the extruder is maintained at a temperature at which the raw material resin melts, and the temperature is the highest in the resin melting portion from the raw material supply port to the foaming agent introduction port, and is usually 150.
The temperature of the melt-kneaded product at the tip of the extruder (extruder outlet temperature) is 140 to 170 ° C.
Held in. Also, the internal pressure of the extruder gradually drops from the foaming agent introduction port toward the tip of the extruder. The pressure of the molten polystyrene resin at the foaming agent inlet of the extruder is 150
˜300 kgf / cm 2 G, but the pressure of the melt-kneaded product at the tip of the extruder (extruder outlet pressure) is 50 to 150 kg.
f / cm 2 G.

【０００９】本発明においては、前記したように、押出
機出口温度を１４０〜１７０℃及び押出機出口圧を５０
〜１５０ｋｇｆ／ｃｍ2Ｇの条件に保持し、この条件で
押出機先端から溶融混練物を押出し、ギヤーポンプに移
送する。ギヤーポンプの入口圧は、押出機内部圧力を効
率よく低下させるために、１２０ｋｇｆ／ｃｍ2Ｇ以
下、好ましくは３０〜１１０ｋｇｆ／ｃｍ2Ｇに保持す
るのがよい。本発明では、低発泡品を得るために、前記
したように発泡剤の添加量が５重量％以下、特に２重量
％以下という少量であることから、押出機内の溶融樹脂
粘度は、高発泡品を得る場合に比べて著しく高いものに
なっている。従って、押出機内温度を低く保持して溶融
樹脂と発泡剤を均一に混合しようとすると、押出機内の
圧力が高くなりすぎて、押出機内のスクリューやそれを
駆動させるモータに過負荷がかかり、スクリューやモー
タが破損する等の問題が生じる。一方、押出機内部温度
を高くして溶融樹脂と発泡剤の均質混合性を高めようと
すると、この場合には得られる溶融混練物の温度が高す
ぎ、これを大気中に押出して発泡させると、発泡過程に
おけるセルの成長過程でセル膜に延伸がかからず、得ら
れる発泡体は強度が弱くなるとともに、もろいものとな
り、さらに発泡剤のセルからの抜けが速くなり、二次発
泡性の悪いものとなってしまう。本発明では、このよう
な問題を解決するために、前記したように、ギヤーポン
プを用い、押出機先端部からの高粘性の溶融物をギヤー
ポンプにより吸引し、強制的に引取ることにより、押出
機内で比較的低い温度及び圧力条件で樹脂と発泡剤との
均質混合を円滑に行ない、得られた溶融混練物を押出機
先端から円滑に押出するこを可能にしたものである。In the present invention, as described above, the extruder outlet temperature is 140 to 170 ° C. and the extruder outlet pressure is 50.
The melt-kneaded product is extruded from the tip of the extruder under the conditions of 150 kgf / cm 2 G and transferred to a gear pump. The inlet pressure of the gear pump may be maintained at 120 kgf / cm 2 G or less, preferably 30 to 110 kgf / cm 2 G in order to efficiently reduce the internal pressure of the extruder. In the present invention, in order to obtain a low-foamed product, the amount of the foaming agent added is as small as 5% by weight or less, particularly 2% by weight or less as described above. It is significantly higher than when you get. Therefore, if you try to mix the molten resin and the foaming agent uniformly while keeping the temperature inside the extruder low, the pressure inside the extruder becomes too high, and the screw in the extruder and the motor that drives it are overloaded, And problems such as damage to the motor occur. On the other hand, if the temperature inside the extruder is increased to increase the homogeneity of mixing of the molten resin and the foaming agent, in this case, the temperature of the melt-kneaded product obtained is too high, and if this is extruded into the atmosphere and foamed. In the foaming process, the cell membrane is not stretched during the cell growth process, and the resulting foam becomes weak and brittle, and the foaming agent quickly escapes from the cell, resulting in a secondary foaming property. It becomes bad. In the present invention, in order to solve such a problem, as described above, by using a gear pump, a highly viscous melt from the tip of the extruder is sucked by the gear pump and forcibly withdrawn, whereby In this way, the resin and the foaming agent can be smoothly mixed under relatively low temperature and pressure conditions, and the obtained melt-kneaded product can be smoothly extruded from the tip of the extruder.

【００１０】前記のようにしてギヤーポンプに移送され
た溶融混練物は、ここでダイスからのポリスチレン系樹
脂の押出発泡条件に適した１５０〜２５０ｋｇｆ／ｃｍ
2Ｇの圧力に昇圧させる。この場合、ギヤーポンプにお
ける昇圧割合Ｐ（Ｏ）／Ｐ（Ｉ）（Ｐ（Ｉ）：ギヤーポ
ンプの入口圧、Ｐ（Ｏ）：ギヤーポンプ出口圧）は、
１．６以上、好ましくは１．６〜５．０程度に保持する
のがよく、このような昇圧割合にすることにより、押出
機出口での圧力条件を前記した５０〜１５０ｋｇｆ／ｃ
ｍ2Ｇという低圧に容易に保持することが可能となると
ともに、押出機内部圧も低められ、発熱を生じることな
く樹脂と発泡剤との均質混合が可能となる。また、この
ような昇圧割合では、ギヤーポンプ内における溶融混練
物の剪断発熱も少なく、ギヤーポンプ内での溶融混練物
の温度上昇を１０℃以下に抑制することが可能になり、
ダイスから押出す溶融混練物の温度をポリスチレン系樹
脂の適正発泡温度である１３５〜１８５℃の範囲に保持
することが容易になる。なお、前記昇圧割合Ｐ（Ｉ）／
Ｐ（Ｏ）が前記範囲より低いと押出機からの溶融混練物
の吸引効果が低すぎて、押出機内圧力の低下が不十分に
なり、一方、前記範囲より高いと、ギヤーポンプ内の発
熱が多くなり、ギヤーポンプから排出される溶融混練物
の温度が高くなりすぎる。The melt-kneaded material transferred to the gear pump as described above is 150 to 250 kgf / cm suitable for the extrusion and foaming conditions of the polystyrene resin from the die.
Increase the pressure to 2 G. In this case, the pressure increase ratio P (O) / P (I) in the gear pump (P (I): inlet pressure of the gear pump, P (O): outlet pressure of the gear pump) is
It is preferable to maintain the pressure at 1.6 or more, preferably about 1.6 to 5.0. By setting such a pressurizing ratio, the pressure condition at the exit of the extruder is 50 to 150 kgf / c.
It becomes possible to easily maintain the low pressure of m 2 G, and the internal pressure of the extruder is lowered, so that the resin and the foaming agent can be homogeneously mixed without generating heat. Further, at such a pressurizing rate, the sheared heat generation of the melt-kneaded material in the gear pump is small, and the temperature rise of the melt-kneaded material in the gear pump can be suppressed to 10 ° C. or less,
It becomes easy to maintain the temperature of the melt-kneaded product extruded from the die within the range of 135 to 185 ° C. which is the proper foaming temperature of the polystyrene resin. The boost rate P (I) /
If P (O) is lower than the above range, the effect of sucking the melt-kneaded product from the extruder is too low, and the pressure drop in the extruder becomes insufficient. On the other hand, if it is higher than the range, the heat generated in the gear pump is large. And the temperature of the melt-kneaded product discharged from the gear pump becomes too high.

【００１１】前記のようにしてギヤーポンプから排出さ
れる溶融混練物は、ポリスチレン系樹脂の押出し発泡条
件に適した温度１３５〜１８５℃、圧力１５０〜２５０
ｋｇｆ／ｃｍ2Ｇの条件でダイスを通して大気圧下に押
出して発泡体とされる。溶融混練物をダイスから押出す
る場合、筒状に押出し発泡させることができ、この場合
には押出方向の一端より切開いて低発泡ポリスチレン系
樹脂シートとすることができる。このシートはロール状
に巻き取り、保管する。本発明で得られるＬＦＰＳシー
トは、好ましくはその発泡倍率が１．５〜７倍程度、即
ち、発泡体密度が０．１５〜０．７０ｇ／ｃｍ3低発泡
体であり、強度及び強靭性にすぐれるとともに、二次発
泡性にすぐれた高品質のものである。また、本発明のＬ
ＦＰＳシートは、低発泡体であるにも拘らずロールに巻
き取っても折れたり割れたりすることなく、物流面でも
有利なものである。The melt-kneaded product discharged from the gear pump as described above has a temperature of 135 to 185 ° C. and a pressure of 150 to 250 suitable for the extrusion and foaming conditions of the polystyrene resin.
A foam is extruded under atmospheric pressure through a die under the condition of kgf / cm 2 G. When the melt-kneaded product is extruded from a die, it can be extruded into a tubular shape and foamed, and in this case, it can be cut open from one end in the extruding direction to form a low-expansion polystyrene-based resin sheet. This sheet is wound into a roll and stored. The LFPS sheet obtained by the present invention is preferably a foam having a foaming ratio of about 1.5 to 7 times, that is, a foam density of 0.15 to 0.70 g / cm 3 low foam, and has high strength and toughness. It is a high-quality product that is excellent and has excellent secondary foaming properties. In addition, L of the present invention
Despite being a low foam material, the FPS sheet does not break or crack when wound on a roll, which is advantageous in terms of physical distribution.

【００１２】[0012]

【実施例】次に本発明法を実施例によって詳細に説明す
るが、本発明は実施例によって制限されるものではな
い。EXAMPLES The method of the present invention will now be described in detail with reference to examples, but the present invention is not limited to the examples.

【００１３】実施例１ この実験においては、押出し発泡装置として、内径９０
ｍｍのシリンダーを持つ実験用押出機の先端にギヤーポ
ンプ入口を連結し、ギヤーポンプの出口に押出し用のダ
イスを連絡したものを使用した。ギヤーポンプとして
は、ヘリカルギヤーポンプを用いた。前記した押出発泡
装置を用い、気泡調整剤として１．１重量％のタルクを
加えたメルトフローレート（ＭＦＲ）：３ｇ／１０分の
汎用ポリスチレンをシート状に発泡成形し、ＬＦＰＳシ
ートを得た。この場合、発泡剤としてはブタンを樹脂と
タルクとの総量対して０．８重量％の割合で用いた。ま
た、ＬＦＰＳシートの製造速度は５０ｋｇ／ｈｒであ
り、ＬＦＰＳシートの厚さは約２．０ｍｍであった。こ
の実験における押出機及びギヤーポンプの温度と圧力条
件及び得られたＬＦＰＳシートの密度について、表１に
示す。なお、表１に示した各符号の内容は次の通りであ
る。 Ｐ（１）：ブタン導入口部における押出機内部の溶融ポ
リスチレンの圧 Ｐ（２）：押出機出口の溶融混練物の圧 Ｐ（Ｉ）：ギヤーポンプ入口部における溶融混練物の圧 Ｐ（Ｏ）：ギヤーポンプ出口部における溶融混練物の圧 Ｐ（Ｄ）：ダイス内の溶融混練物の圧 Ｔ1：押出機出口における溶融混練物の温度 Ｔ2：ダイス内の溶融混練物の温度（発泡温度）Example 1 In this experiment, an extrusion foaming device was used, which had an inner diameter of 90.
A gear extruder inlet was connected to the tip of an experimental extruder having a cylinder of mm, and an extruder die was connected to the outlet of the gear pump. A helical gear pump was used as the gear pump. Using the above-mentioned extrusion foaming apparatus, general-purpose polystyrene to which 1.1% by weight of talc was added as a cell adjuster (MFR): 3 g / 10 min was foam-molded into a sheet to obtain an LFPS sheet. In this case, butane was used as the foaming agent in a ratio of 0.8% by weight based on the total amount of the resin and talc. The production rate of the LFPS sheet was 50 kg / hr, and the thickness of the LFPS sheet was about 2.0 mm. Table 1 shows the temperature and pressure conditions of the extruder and the gear pump and the density of the obtained LFPS sheet in this experiment. The contents of each symbol shown in Table 1 are as follows. P (1): Pressure of molten polystyrene inside extruder at butane introduction port P (2): Pressure of melt kneaded product at extruder outlet P (I): Pressure of melt kneaded product at gear pump inlet P (O) : pressure of the melt-kneaded product at the gear pump outlet P (D): pressure of the melt-kneaded product of the die T 1: temperature T 2 of the melt-kneaded material in the extruder outlet: temperature of the melt-kneaded product of the die (foaming temperature)

【００１４】実施例２ ブタン添加量を１．９重量％、タルク添加量を０．８重
量％、ギャーポンプ入口圧を４０Ｋｇｆ／ｃｍ2とした
ほかは実施例１と同様にして実験を行った。Example 2 An experiment was conducted in the same manner as in Example 1 except that the addition amount of butane was 1.9% by weight, the addition amount of talc was 0.8% by weight, and the inlet pressure of the gear pump was 40 kgf / cm 2 . ..

【００１５】実施例３ ギャーポンプ入口圧を１００Ｋｇｆ／ｃｍ2とした以外
は実施例１と同様にして実験を行った。Example 3 An experiment was conducted in the same manner as in Example 1 except that the gear pump inlet pressure was 100 Kgf / cm 2 .

【００１６】実施例４ ギャーポンプ入口圧を１１０Ｋｇｆ／ｃｍ2とし、ブタ
ン添加量を１．５重量％とした以外は実施例１と全く同
一の実験を行った。Example 4 Exactly the same experiment as in Example 1 was conducted except that the inlet pressure of the gear pump was 110 kgf / cm 2 and the amount of butane added was 1.5% by weight.

【００１７】比較例１ 押出機出口圧を１８０Ｋｇｆ／ｃｍ2とし、ギャーポン
プを使用しない以外は実施例１と同様にして実験を行っ
た。Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that the extruder outlet pressure was 180 kgf / cm 2 and the gear pump was not used.

【００１８】比較例２ ギャーポンプ入口圧を１３０Ｋｇｆ／ｃｍ2とした以外
は実施例１と同様にして実験を行った。Comparative Example 2 An experiment was conducted in the same manner as in Example 1 except that the gear pump inlet pressure was 130 kgf / cm 2 .

【００１９】実施例１〜４で得られたＬＦＰＳシートは
いずれも深しぼり成形性にすぐれ、熱成形によりコップ
等の深物容器を容易に得ることができた。また、トレー
等の浅物容器に成形した場合には、細部形状に至るまで
金型形状を正確に再現した成形品を得ることができた。
また、これらの実施例では、押出機の出口圧を１５０ｋ
ｇｆ／ｃｍ2以下に保持し得るので、格別の内部発熱を
生じることなく、押出機の運転を円滑に行うことができ
た。一方、比較例１及び比較例２では、押出機出口圧が
１５０ｋｇｆ／ｃｍ2Ｇを超えるため、押出機の円滑運
転及び発泡剤と樹脂との均一混合に難点が生じるととも
に、比較例１ではダイス出口温度が高すぎるため、得ら
れるＬＦＰＳシートはもろく、ロール状に巻取ることが
できなかった。また、このものは二次発泡性にも劣った
ものであった。比較例２で得られるＬＦＰＳシートは、
ロール巻きできない程もろくはないが、これを真空成形
した時にニップではさんだ時、そのはさんだ部分に割れ
を生じた。All of the LFPS sheets obtained in Examples 1 to 4 were excellent in deep-drawing moldability, and a deep container such as a cup could be easily obtained by thermoforming. Further, when molded into a shallow container such as a tray, it was possible to obtain a molded product in which the mold shape was accurately reproduced down to the detailed shape.
Also, in these examples, the outlet pressure of the extruder was 150 k
Since it can be maintained at gf / cm 2 or less, the internal combustion of the extruder was not generated, and the operation of the extruder could be smoothly performed. On the other hand, in Comparative Example 1 and Comparative Example 2, since the extruder outlet pressure exceeds 150 kgf / cm 2 G, there are problems in smooth operation of the extruder and uniform mixing of the foaming agent and the resin. Since the outlet temperature was too high, the obtained LFPS sheet was brittle and could not be wound into a roll. Further, this product was also inferior in secondary foaming property. The LFPS sheet obtained in Comparative Example 2 is
It's not so brittle that it can be rolled, but when it was vacuum formed, it was cracked at the nip when it was caught in the nip.

【００２０】[0020]

【表１】 [Table 1]

【００２１】[0021]

【発明の効果】本発明によれば、ポリスチレン系樹脂を
原料とし、これから生産性良くかつ高品質の低密度発泡
ポリスチレン系樹脂シートを得ることができる。本発明
の低密度発泡ポリスチレン系樹脂シートは、強靭性を有
し、ロール巻取りが容易なものである上、二次成形成性
にもすぐれ、真空成形や圧空成形用原料シートとして好
適なものである。According to the present invention, a polystyrene resin is used as a raw material, and a low density expanded polystyrene resin sheet having high productivity and high quality can be obtained therefrom. The low-density expanded polystyrene resin sheet of the present invention has toughness, is easy to roll up, and has excellent secondary formation properties, and is suitable as a raw material sheet for vacuum forming or pressure forming. Is.

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０８Ｌ 25:00 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification code Office reference number FI technical display area C08L 25:00

Claims (16)

【特許請求の範囲】[Claims] 【請求項１】 ポリスチレン系樹脂と発泡剤とを押出機
内で溶融混練した後、得られた溶融混練物をギヤーポン
プを通過させ、次いでダイスより溶融混練物を押出して
低発泡ポリスチレン系樹脂シートを製造する方法であっ
て、上記溶融混練物のギヤーポンプ入口部における圧力
を１２０ｋｇｆ／ｃｍ2Ｇ以下とすることを特徴とする
低発泡ポリスチレン系樹脂シートの製造方法。1. A low-expansion polystyrene resin sheet is produced by melt-kneading a polystyrene resin and a foaming agent in an extruder, passing the obtained melt-kneaded product through a gear pump, and then extruding the melt-kneaded product from a die. The method for producing a low expanded polystyrene resin sheet, characterized in that the pressure at the gear pump inlet of the melt-kneaded product is 120 kgf / cm 2 G or less. 【請求項２】 ギヤーポンプの入口部における圧力が３
０〜１１０ｋｇｆ／ｃｍ2Ｇである請求項１の方法。2. The pressure at the inlet of the gear pump is 3
The method according to claim 1, which is 0 to 110 kgf / cm 2 G. 【請求項３】 溶融混練物のギヤーポンプ入口部の圧力
をＰ（Ｉ）とし、ギヤーポンプ出口部の圧力をＰ（Ｏ）
としたときのＰ（Ｏ）／Ｐ（Ｉ）の値が１．６以上とな
るように上記出口圧Ｐ（Ｏ）を昇圧することを特徴とす
る請求項１または請求項２の方法。3. The pressure at the gear pump inlet of the melt-kneaded product is P (I), and the pressure at the gear pump outlet is P (O).
3. The method according to claim 1, wherein the outlet pressure P (O) is increased so that the value of P (O) / P (I) is 1.6 or more. 【請求項４】 Ｐ（Ｏ）／Ｐ（Ｉ）の値が１．６〜５．
０となるように上記出口圧Ｐ（Ｏ）を昇圧することを特
徴とする請求項３の方法。4. The value of P (O) / P (I) is 1.6-5.
The method according to claim 3, wherein the outlet pressure P (O) is increased so as to become zero. 【請求項５】 押出機の途中に発泡剤注入口を持つ押出
機を使用し、該注入口より押出機内の溶融ポリスチレン
系樹脂に発泡剤を注入する請求項１〜請求項４のいずれ
かの方法。5. An extruder having a foaming agent injection port in the middle of the extruder is used, and the foaming agent is injected into the molten polystyrene resin in the extruder through the injection port. Method. 【請求項６】 発泡剤注入口部の押出機内の溶融ポリス
チレン系樹脂の圧力及び温度をそれぞれ１５０〜３００
ｋｇｆ／ｃｍ2Ｇ及び１５０〜２５０℃とし、押出機先
端部の押出機内の溶融混練物の圧力及び温度をそれぞれ
５０〜１５０ｋｇｆ／ｃｍ2Ｇ及び１４０〜１７０℃と
し、ダイス内の溶融混練物の圧力及び温度をそれぞれ１
５０〜２５０ｋｇｆ／ｃｍ2Ｇ及び１３５〜１８５℃と
することを特徴とする請求項１〜請求項５のいずれかの
方法。6. The pressure and temperature of the molten polystyrene resin in the extruder at the blowing agent injection port are 150 to 300, respectively.
and kgf / cm 2 G and 150 to 250 ° C., the pressure and temperature of the extruder melt-kneading of the extruder tip and each 50~150kgf / cm 2 G and 140 to 170 ° C., the melt-kneaded product in the die 1 for pressure and 1 for temperature
50-250 kgf / cm < 2 > G and 135-185 degreeC are set, The method in any one of Claims 1-5 characterized by the above-mentioned. 【請求項７】 ギヤーポンプとしてヘリカルギヤーポン
プを使用する請求項１〜請求項６のいずれかの方法。7. The method according to claim 1, wherein a helical gear pump is used as the gear pump. 【請求項８】 ポリスチレン系樹脂が、ポリスチレン、
スチレン／ブタジエン共重合体、スチレン／ブタジエン
／アクリロニトリル共重合体、スチレン／アクリル酸共
重合体、スチレン／メタクリル酸共重合体、スチレン／
無水マレイン酸共重合体、スチレン／エチレン共重合体
及びスチレン／塩化ビニル共重合体の中より選ばれる単
独または２以上の混合物を主成分とし、しかも全成分中
の５０重量％以上がスチレン成分であり、且つそのメル
トフローレート（ＭＦＲ）が０．５〜３０ｇ／１０分で
あることを特徴とする請求項１〜請求項７のいずれかの
方法。8. The polystyrene resin is polystyrene,
Styrene / butadiene copolymer, styrene / butadiene / acrylonitrile copolymer, styrene / acrylic acid copolymer, styrene / methacrylic acid copolymer, styrene /
The main component is a single or a mixture of two or more selected from maleic anhydride copolymers, styrene / ethylene copolymers and styrene / vinyl chloride copolymers, and 50% by weight or more of all components are styrene components. And the melt flow rate (MFR) thereof is 0.5 to 30 g / 10 minutes. 【請求項９】 発泡剤が、プロパン、ｎ−ブタン、ｉｓ
ｏ−ブタン、ｎ−ペタン、ｉｓｏ−ペタン、ｎ−ヘキサ
ン、ｉｓｏ−ヘキサン、シクロヘキサン、クロロジフロ
ロメタン、１，１，１−トリフロロ−２，２−ジクロロ
エタン、１，１，１，２−テトラフロロエタン、１，１
−ジクロロ−１−クロロエタン、１，１−ジフロロエタ
ン、１，１，１，２−テトラフロロ−２−クロロエタン
及び１，１−ジクロロ−１−フロロエタンの中から選ば
れる単独または２以上の混合物を主成分とする発泡剤で
あることを特徴とする請求項１〜請求項８のいずれかの
方法。9. The blowing agent is propane, n-butane, is
o-butane, n-petane, iso-petane, n-hexane, iso-hexane, cyclohexane, chlorodifluoromethane, 1,1,1-trifluoro-2,2-dichloroethane, 1,1,1,2-tetra Fluoroethane, 1,1
-Dichloro-1-chloroethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoro-2-chloroethane, and 1,1-dichloro-1-fluoroethane as a main component, or a mixture of two or more selected from The method according to any one of claims 1 to 8, which is a foaming agent. 【請求項１０】 発泡剤が溶融混練物中の５重量％以
下、好ましくは０．０１〜２重量％となるように添加さ
れる請求項１〜請求項９のいずれかの方法。10. The method according to claim 1, wherein the foaming agent is added in an amount of 5% by weight or less, preferably 0.01 to 2% by weight, in the melt-kneaded product. 【請求項１１】 溶融混練物中に添加剤を含有する請求
項１〜請求項１０のいずれかの方法。11. The method according to claim 1, wherein the melt-kneaded product contains an additive. 【請求項１２】 添加剤が、タルク、炭酸マグネシウ
ム、パーライト、珪酸カルシウム、炭酸カルシウム、酸
化珪素、バライタ、バーミキュライト、珪酸、クエン
酸、酒石酸及び蓚酸の中より選ばれる単独または２以上
の混合物からなる気泡調整剤、炭素数１２〜２２の高級
脂肪酸と、カルシウム、ナトリウム、カリウム、リチウ
ム、アルミニウムは亜鉛の中から選ばれる金属との化合
物である高級脂肪酸金属塩からなる滑剤、または／及び
顔料である請求項１１に記載の方法。12. The additive comprises one or a mixture of two or more selected from talc, magnesium carbonate, perlite, calcium silicate, calcium carbonate, silicon oxide, baryta, vermiculite, silicic acid, citric acid, tartaric acid and oxalic acid. A foam regulator, a lubricant containing a higher fatty acid having 12 to 22 carbon atoms and a higher fatty acid metal salt which is a compound of a metal selected from zinc among calcium, sodium, potassium, lithium and aluminum, and / or a pigment. The method according to claim 11. 【請求項１３】 溶融混練物中において、気泡調整剤が
０．１〜３重量％となるように、高級脂肪酸金属塩が０
〜１．０重量％となるように、かつ顔料が０〜１５重量
％となるように添加剤を添加することを特徴とする請求
項１１または請求項１２の方法。13. The higher fatty acid metal salt is contained in the melt-kneaded product so that the amount of the cell regulator is 0.1 to 3% by weight.
The method according to claim 11 or 12, characterized in that the additive is added so that the amount of the pigment is 0 to 1.0% by weight and the amount of the pigment is 0 to 15% by weight. 【請求項１４】 ダイスとして環状ダイスを使用し、ポ
リスチレン系樹脂を筒状に押出発泡させ、次いで筒状発
泡体を押出方向の一端より切り開いて、密度が０．１３
ｇ／ｃｍ3以上、好ましくは０．１５〜０．７ｇ／ｃ
ｍ3、厚みが０．３〜３ｍｍの実質的に独立気泡の低発
泡ポリスチレン系樹脂シートを得ることを特徴とする請
求項１〜請求項１３のいずれかの方法。14. A circular die is used as a die, a polystyrene resin is extruded and foamed into a tubular shape, and then the tubular foam is cut open from one end in the extrusion direction to give a density of 0.13.
g / cm 3 or more, preferably 0.15 to 0.7 g / c
The method according to any one of claims 1 to 13, wherein a low-foaming polystyrene-based resin sheet having m3 and a thickness of 0.3 to 3 mm and substantially closed cells is obtained. 【請求項１５】 得られた低発泡ポリスチレン系樹脂シ
ートをロール状に巻き取る請求項１〜請求項１４のいず
れかの方法。15. The method according to claim 1, wherein the obtained low-foaming polystyrene resin sheet is wound into a roll. 【請求項１６】 ＭＦＲが０．５〜１０ｇ／１０分のポ
リスチレンと、タルクを含有するポリスチレンとを、タ
ルクがポリスチレンと発泡剤とタルクとの総和に対して
０．１〜３重量％の割合となるように押出機内に入れ、
押出機内での溶融ポリスチレンの圧力及び温度をそれぞ
れ１５０〜３００ｋｇｆ／ｃｍ2Ｇ及び１５０〜２５０
℃となるようにポリスチレンを溶融混合した後、押出機
の途中の発泡剤注入口より溶融混練物中０．０１〜２重
量％の割合になるようにｎ−ブタンまたは／及びｉｓｏ
−ブタンを圧入し、これら混合物を溶融混練しながら冷
却しつつ移送して押出機先端での溶融混練物の圧力及び
温度をそれぞれ５０〜１５０ｋｇｆ／ｃｍ2Ｇ及び１４
０〜１７０℃とし、得られた溶融混練物を圧力３０〜１
１０ｋｇｆ／ｃｍ2Ｇでヘリカルギヤーポンプの入口部
に導き、次いでギヤーポンプ出口部の溶融混練物の圧力
を入口部の圧力の１．６〜５倍となるようにギヤーポン
プ内で溶融混練物を昇圧しつつ通過させ、続いてこれを
ダイスに導き、ダイス内での圧力及び温度をそれぞれ１
５０〜２５０ｋｇｆ／ｃｍ2Ｇ及び１３５℃以上１８５
℃未満とし、その後これらを筒状に押出発泡させ、押出
方向の一端より切り開いて密度０．１５〜０．７ｇ／ｃ
ｍ3、厚み０．３〜３ｍｍの実質的に独立気泡の低発泡
ポリスチレン樹脂シートとし、その後該シートをロール
状に巻き取ることを特徴とする真空成形または／及び圧
空成形等の成形性に優れた低発泡ポリスチレン系樹脂シ
ートの製造方法。16. A polystyrene having an MFR of 0.5 to 10 g / 10 min and a polystyrene containing talc in a proportion of 0.1 to 3% by weight based on the total amount of polystyrene, a foaming agent and talc. Put it in the extruder so that
The pressure and temperature of the molten polystyrene in the extruder were 150 to 300 kgf / cm 2 G and 150 to 250, respectively.
After the polystyrene was melt-mixed to reach the temperature of 0 ° C., n-butane or / and iso was added from the blowing agent injection port in the middle of the extruder so that the content was 0.01 to 2% by weight in the melt-kneaded product.
-Butane is pressed in, and the mixture is melted and kneaded and transferred while being cooled so that the pressure and temperature of the melted and kneaded material at the tip of the extruder are 50 to 150 kgf / cm 2 G and 14 respectively.
The temperature is set to 0 to 170 ° C., and the obtained melt-kneaded product is pressurized to 30 to 1
While introducing 10 kgf / cm 2 G to the inlet of the helical gear pump, and then increasing the pressure of the melt-kneaded material in the gear pump so that the pressure of the melt-kneaded material at the gear pump outlet is 1.6 to 5 times the pressure at the inlet. It is allowed to pass, and then it is introduced into the die, and the pressure and temperature inside the die are set to 1
50-250 kgf / cm 2 G and 135 ° C or higher 185
Below 100C, and then extruding and foaming these into a cylindrical shape, cutting open from one end in the extruding direction to obtain a density of 0.15 to 0.7 g / c.
m 3 and a thickness of 0.3 to 3 mm, which is a substantially foamed low-expanded polystyrene resin sheet, and is then wound into a roll, which is excellent in moldability such as vacuum forming and / or pressure forming. A method for producing a low-expanded polystyrene-based resin sheet.
JP4032712A 1992-01-23 1992-01-23 Manufacture of low formable polystyrene resin sheet Pending JPH05200835A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4032712A JPH05200835A (en) 1992-01-23 1992-01-23 Manufacture of low formable polystyrene resin sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4032712A JPH05200835A (en) 1992-01-23 1992-01-23 Manufacture of low formable polystyrene resin sheet

Publications (1)

Publication Number Publication Date
JPH05200835A true JPH05200835A (en) 1993-08-10

Family

ID=12366453

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4032712A Pending JPH05200835A (en) 1992-01-23 1992-01-23 Manufacture of low formable polystyrene resin sheet

Country Status (1)

Country Link
JP (1) JPH05200835A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996000258A1 (en) * 1994-06-23 1996-01-04 The Dow Chemical Company Extruded, open-cell foam and process for making
US5889069A (en) * 1997-07-15 1999-03-30 The Dow Chemical Company High temperature syndiotactic styrene polymer foam
CN114410023A (en) * 2021-12-17 2022-04-29 金发科技股份有限公司 Polystyrene material and preparation method and application thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996000258A1 (en) * 1994-06-23 1996-01-04 The Dow Chemical Company Extruded, open-cell foam and process for making
US5889069A (en) * 1997-07-15 1999-03-30 The Dow Chemical Company High temperature syndiotactic styrene polymer foam
US6051621A (en) * 1997-07-15 2000-04-18 The Dow Chemical Company High temperature syndiotactic styrene polymer foam
CN114410023A (en) * 2021-12-17 2022-04-29 金发科技股份有限公司 Polystyrene material and preparation method and application thereof
CN114410023B (en) * 2021-12-17 2023-07-07 金发科技股份有限公司 Polystyrene material and preparation method and application thereof

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