JPH0649259A - Production of foamed polycarbonate resin - Google Patents
Production of foamed polycarbonate resinInfo
- Publication number
- JPH0649259A JPH0649259A JP20232792A JP20232792A JPH0649259A JP H0649259 A JPH0649259 A JP H0649259A JP 20232792 A JP20232792 A JP 20232792A JP 20232792 A JP20232792 A JP 20232792A JP H0649259 A JPH0649259 A JP H0649259A
- Authority
- JP
- Japan
- Prior art keywords
- polycarbonate resin
- temperature
- carbon dioxide
- dioxide gas
- pressure
- 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
- 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、発泡剤としてクリーン
で安全な炭酸ガスを使用した高発泡倍率のポリカーボネ
ート樹脂発泡体の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polycarbonate resin foam having a high expansion ratio using a clean and safe carbon dioxide gas as a foaming agent.
【０００２】[0002]
【従来の技術】従来、ポリカーボネート樹脂発泡体の製
造方法としては、他の熱可塑性樹脂発泡体の製造方法と
同様に、熱分解型化学発泡剤を樹脂に練り込み、該発泡
剤の分解温度以上に加熱することにより発泡せしめる化
学発泡剤法と、ペンタン、ヘキサン、オクタン等の脂肪
族炭化水素、あるいはジクロロジフロロメタン等のフッ
素化脂肪族炭化水素のようなポリカーボネート樹脂の融
点以下に沸点を有する有機ガスまたは揮発性液体を溶融
樹脂に圧入した後、低圧域に放出して発泡せしめるガス
発泡法（特開平２−２６１８３６号公報）が知られてい
る。2. Description of the Related Art Conventionally, as a method for producing a polycarbonate resin foam, similar to other thermoplastic resin foam production methods, a pyrolytic chemical foaming agent is kneaded into a resin to obtain a temperature not lower than the decomposition temperature of the foaming agent. It has a boiling point below the melting point of a polycarbonate resin such as a chemical foaming agent method in which it is foamed by heating to, and an aliphatic hydrocarbon such as pentane, hexane, octane, or a fluorinated aliphatic hydrocarbon such as dichlorodifluoromethane. There is known a gas foaming method (Japanese Patent Laid-Open No. 2-261836) in which an organic gas or a volatile liquid is pressed into a molten resin and then discharged into a low pressure region to foam.
【０００３】ポリカーボネート樹脂に化学発泡剤法を適
用することにより、均一かつ微細な独立気泡を有する発
泡体を得ることができるが、発泡体中に残存する発泡剤
の分解残渣のために、ポリカーボネート樹脂が分解した
り、発泡体の変色、臭気の発生、食品衛生上の問題など
を生じる。By applying a chemical foaming agent method to a polycarbonate resin, a foam having uniform and fine closed cells can be obtained. However, due to the decomposition residue of the foaming agent remaining in the foam, the polycarbonate resin is Cause decomposition, discoloration of foam, generation of odor, and food hygiene problems.
【０００４】一方、ガス発泡法については、使用する発
泡剤が脂肪族炭化水素の場合、発泡体製造時に爆発性の
ガスを発生するので爆発の危険が生じる。また、使用す
る発泡剤がフッ素化脂肪族炭化水素の場合、爆発の危険
は少ないが、オゾン層破壊等の環境問題から全廃の方向
へ進んでいる。このような従来法の問題点を解決するた
めに、窒素ガス、アルゴン等の不活性ガス、あるいは炭
酸ガスや水を発泡剤として使用するガス発泡法が提案さ
れている。On the other hand, in the gas foaming method, when the foaming agent to be used is an aliphatic hydrocarbon, an explosive gas is generated during the production of the foam, which causes a danger of explosion. In addition, when the blowing agent used is a fluorinated aliphatic hydrocarbon, the risk of explosion is low, but due to environmental problems such as ozone layer depletion, it is moving toward total elimination. In order to solve the problems of the conventional method, a gas foaming method using nitrogen gas, an inert gas such as argon, carbon dioxide gas or water as a foaming agent has been proposed.
【０００５】水は、クリーンであり、前記のような問題
は生じないが、ポリカーボネート樹脂の加熱時に水が存
在すると、ポリカーボネート樹脂中の炭酸エステル結合
が分解するという不都合が起こり易い。特開昭５３−９
２８７４号には、ポリカーボネート樹脂の水による分解
を抑えるために、エポキシ化合物を添加すると共に、ポ
リカーボネートの吸着水で発泡させる方法が開示されて
いるが、ポリカーボネートの吸湿率は０．１５〜０．３
％と低いため、せいぜい発泡倍率２〜３倍の低発泡倍率
の発泡体しか得ることができない。Although water is clean and does not cause the above-mentioned problems, the presence of water during heating of the polycarbonate resin tends to cause the disadvantage that the carbonic acid ester bond in the polycarbonate resin is decomposed. JP-A-53-9
No. 2874 discloses a method of adding an epoxy compound and foaming with the adsorbed water of the polycarbonate in order to suppress the decomposition of the polycarbonate resin by water, but the moisture absorption rate of the polycarbonate is 0.15 to 0.3.
%, It is only possible to obtain a foam having a low expansion ratio of at most 2-3 times.
【０００６】窒素ガスやアルゴン等の不活性ガスは、ク
リーンであり、水のような加熱時におけるポリカーボネ
ート樹脂の分解の心配はないが、ポリカーボネート樹脂
に対する溶解度が非常に低いため、高発泡倍率の発泡体
を得ることは困難である。Inert gas such as nitrogen gas or argon is clean and there is no fear of decomposition of the polycarbonate resin when heated like water, but since the solubility in the polycarbonate resin is very low, foaming with a high expansion ratio is performed. Getting a body is difficult.
【０００７】これに対して、炭酸ガスは、クリーンであ
る上、ポリカーボネート樹脂に溶解したときに可塑剤と
して作用するため、ポリカーボネート樹脂のガラス転移
点よりも約９０℃低い温度から発泡が可能となる。とこ
ろが、炭酸ガスのポリカーボネート樹脂に対する溶解度
は、室温付近では不活性ガスに比べて著しく高いもの
の、ポリカーボネート樹脂の融点付近では、極端にその
溶解度が低下するため、溶融状態にある樹脂にガスを圧
入する通常の押出発泡法では、溶解度があまり上がら
ず、高発泡倍率の発泡体を得ることは困難である。On the other hand, since carbon dioxide gas is clean and acts as a plasticizer when dissolved in the polycarbonate resin, foaming is possible from a temperature about 90 ° C. lower than the glass transition point of the polycarbonate resin. . However, although the solubility of carbon dioxide in a polycarbonate resin is significantly higher than that of an inert gas near room temperature, the solubility thereof is extremely reduced near the melting point of the polycarbonate resin, so that the gas is injected under pressure into the molten resin. In the usual extrusion foaming method, the solubility does not increase so much and it is difficult to obtain a foam having a high expansion ratio.
【０００８】ポリカーボネート樹脂を圧力容器内に置
き、室温付近で炭酸ガスを圧入後、常圧に戻し、グリセ
リンバス中に浸漬して加熱により発泡せしめるバッチ型
常圧発泡法が報告されているが（ワシントン大学機械工
学部Ｋｕｍａｒ助教授）、常圧下での発泡（常圧法）で
あるため、発泡時のガス抜けが激しく、ポリカーボネー
ト樹脂に溶解した炭酸ガスが有効に発泡に寄与せず、高
発泡倍率の発泡体を得ることは困難である。A batch type atmospheric pressure foaming method has been reported in which a polycarbonate resin is placed in a pressure vessel, carbon dioxide gas is injected at around room temperature, then returned to normal pressure, and immersed in a glycerin bath to foam by heating ( (Professor Kumar, Faculty of Mechanical Engineering, University of Washington) Because of the foaming under normal pressure (normal pressure method), the gas release during foaming is severe, and the carbon dioxide gas dissolved in the polycarbonate resin does not contribute effectively to foaming, and foaming with a high expansion ratio Getting a body is difficult.
【０００９】[0009]
【発明が解決しようとする課題】本発明の目的は、前記
従来技術の欠点を克服して、クリーンで安全な発泡剤を
用いて、表面平滑な高発泡倍率のポリカーボネート樹脂
発泡体を製造する方法を提供することにある。SUMMARY OF THE INVENTION The object of the present invention is to overcome the above-mentioned drawbacks of the prior art and to produce a polycarbonate resin foam having a smooth surface and a high expansion ratio by using a clean and safe foaming agent. To provide.
【００１０】本発明者らは、前記課題を解決するために
鋭意研究した結果、ポリカーボネート樹脂を入れた圧力
容器内に炭酸ガスを圧入し、ポリカーボネート樹脂のガ
ラス転移温度よりも５０℃以下の温度に保って、ポリカ
ーボネート樹脂に炭酸ガスを十分溶解させ、次いで該圧
力容器内を１００℃以上に急速に加熱して高温・高圧状
態にした後、低圧域に解放して発泡せしめることによ
り、表面平滑な高発泡倍率のポリカーボネート樹脂発泡
体を製造できることを見いだした。本発明者らは、これ
らの知見に基づいて、本発明を完成するに至った。The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, carbon dioxide gas was injected into a pressure vessel containing a polycarbonate resin so that the temperature was 50 ° C. or lower than the glass transition temperature of the polycarbonate resin. Maintaining the temperature, the carbon dioxide gas is sufficiently dissolved in the polycarbonate resin, and then the inside of the pressure vessel is rapidly heated to 100 ° C. or higher to a high temperature / high pressure state, which is then released into the low pressure region to cause foaming, thereby smoothing the surface. It has been found that a polycarbonate resin foam having a high expansion ratio can be produced. The present inventors have completed the present invention based on these findings.
【００１１】[0011]
【課題を解決するための手段】本発明によれば、ポリカ
ーボネート樹脂を入れた圧力容器内に炭酸ガスを圧入す
ると共に、該圧力容器内の温度をポリカーボネート樹脂
のガラス転移温度よりも５０℃以下の温度に保持して、
ポリカーボネート樹脂に炭酸ガスを溶解させ、次いで、
該圧力容器内の温度を１００℃以上に加熱した後、低圧
域に解放して発泡せしめることを特徴とするポリカーボ
ネート樹脂発泡体の製造方法が提供される。According to the present invention, carbon dioxide gas is pressed into a pressure vessel containing a polycarbonate resin, and the temperature in the pressure vessel is 50 ° C. or lower than the glass transition temperature of the polycarbonate resin. Hold at temperature,
Dissolve carbon dioxide in polycarbonate resin, then
Provided is a method for producing a polycarbonate resin foam, which comprises heating the temperature in the pressure vessel to 100 ° C. or higher, and then releasing the foam in a low pressure region for foaming.
【００１２】以下、本発明について詳述する。ポリカー
ボネート樹脂に対する炭酸ガスの溶解度は、高温領域か
ら低温領域になるほど大きくなる傾向を示す（Ａ．Ｒ．
Ｂｅｒｅｎｓ ｅｔ ａｌ．ＡＣＳＳｙｍｐｏｓ．Ｓｅ
ｒｉｅｓ Ｎｏ．４０６，１９８９）。図１に、炭酸ガ
スを４０ｋｇ／ｃｍ2で圧入したときの、ポリカーボネ
ート樹脂に対する炭酸ガスの溶解度の温度依存性を示し
た。図１からわかるように、２５℃付近から７５℃付近
にかけて溶解度の減少が著しい。したがって、高発泡倍
率のポリカーボネート樹脂発泡体を得るには、炭酸ガス
を室温付近でポリカーボネート樹脂に溶解させることが
有利になる。The present invention will be described in detail below. The solubility of carbon dioxide in a polycarbonate resin tends to increase from a high temperature region to a low temperature region (A.R.
Berens et al. ACS Sympos. Se
ries No. 406, 1989). FIG. 1 shows the temperature dependence of the solubility of carbon dioxide in a polycarbonate resin when carbon dioxide was injected under pressure of 40 kg / cm 2 . As can be seen from FIG. 1, the decrease in solubility is remarkable from around 25 ° C to around 75 ° C. Therefore, in order to obtain a polycarbonate resin foam having a high expansion ratio, it becomes advantageous to dissolve carbon dioxide gas in the polycarbonate resin around room temperature.
【００１３】ところが、室温付近でポリカーボネート樹
脂に炭酸ガスを圧入し、炭酸ガス高溶解ポリカーボネー
ト樹脂を得ても、常圧に戻して、加熱発泡せしめると、
ポリカーボネート樹脂表面からのガス抜けが激しく、溶
解した炭酸ガスが有効に発泡に寄与しない。However, even if carbon dioxide gas is pressed into the polycarbonate resin at around room temperature to obtain a carbon dioxide gas highly dissolved polycarbonate resin, if it is returned to normal pressure and heat-foamed,
Outgassing from the surface of the polycarbonate resin is severe, and the dissolved carbon dioxide does not effectively contribute to foaming.
【００１４】本発明者らは、ポリカーボネート樹脂に溶
解した炭酸ガスを発泡に有効に寄与せしめ、高発泡倍率
のポリカーボネート樹脂発泡体を得る手段を種々検討し
た結果、ポリカーボネート樹脂に低温領域、例えば、室
温付近で炭酸ガスを圧入し、十分溶解させた後、常圧に
戻さず、高圧状態を保持したまま１００℃以上に加熱し
て高温・高圧状態にした後、低圧域に解放して発泡せし
めることにより、ガス抜けを抑えての発泡が可能とな
り、その結果、高発泡倍率のポリカーボネート樹脂発泡
体が製造できることを見いだした。The inventors of the present invention have studied various means for effectively making carbon dioxide gas dissolved in a polycarbonate resin contribute to foaming to obtain a polycarbonate resin foam having a high expansion ratio. As a result, the polycarbonate resin has a low temperature region, for example, room temperature. After pressurizing carbon dioxide in the vicinity to sufficiently dissolve it, do not return it to normal pressure, heat it to 100 ° C or higher while maintaining a high pressure state to a high temperature / high pressure state, and then release it to a low pressure range to foam. As a result, it has been found that foaming can be performed while suppressing outgassing, and as a result, a polycarbonate resin foam having a high expansion ratio can be manufactured.
【００１５】本発明に用いられるポリカーボネート樹脂
は、分子構造中に炭酸エステル結合を持つポリマーであ
って、特に、分子鎖にジフェニルアルカンを有する芳香
族ポリカーボネートは、耐熱性、耐候性、耐酸性が優れ
ているので好ましい。上記芳香族ポリカーボネートとし
ては、例えば２，２−ビス（４−オキシフェニル）プロ
パン、２，２−ビス（４−オキシフェニル）ブタン、
１，１−ビス（４−オキシフェニル）シクロヘキサン、
１，１−ビス（４−オキシフェニル）ブタン、１，１−
ビス（４−オキシフェニル）イソブタン、１，１−ビス
（４−オキシフェニル）エタン等のビスフェノールから
のポリカーボネート樹脂が挙げられる。The polycarbonate resin used in the present invention is a polymer having a carbonic acid ester bond in its molecular structure. Particularly, an aromatic polycarbonate having a diphenylalkane in its molecular chain is excellent in heat resistance, weather resistance and acid resistance. Therefore, it is preferable. Examples of the aromatic polycarbonate include 2,2-bis (4-oxyphenyl) propane, 2,2-bis (4-oxyphenyl) butane,
1,1-bis (4-oxyphenyl) cyclohexane,
1,1-bis (4-oxyphenyl) butane, 1,1-
Examples include polycarbonate resins from bisphenols such as bis (4-oxyphenyl) isobutane and 1,1-bis (4-oxyphenyl) ethane.
【００１６】本発明においては、ポリカーボネート樹脂
の成形に一般に用いられる各種添加剤を必要に応じて添
加してもよい。これらの添加剤としては、可塑剤、滑
剤、抗酸化剤、顔料、難燃剤等の充填剤、タルク、クレ
ー、シリカ、カオリン、炭酸カルシウム等の気泡調整剤
等が挙げられる。In the present invention, various additives generally used for molding a polycarbonate resin may be added if necessary. Examples of these additives include fillers such as plasticizers, lubricants, antioxidants, pigments and flame retardants, and bubble regulators such as talc, clay, silica, kaolin and calcium carbonate.
【００１７】ポリカーボネート樹脂を入れた圧力容器内
に炭酸ガスを圧入するが、その際のポリカーボネート樹
脂の形状は、粒状、ペレット状、シート状、ロッド状な
ど任意である。炭酸ガスを圧入しながら、あるいは圧入
した後、該圧力容器内の温度をポリカーボネート樹脂の
ガラス転移温度よりも５０℃以下の温度に保持して、ポ
リカーボネート樹脂に炭酸ガスを溶解させる。Carbon dioxide gas is pressed into a pressure vessel containing the polycarbonate resin, and the shape of the polycarbonate resin at that time is arbitrary such as granular, pellet-like, sheet-like or rod-like. Carbon dioxide gas is dissolved in the polycarbonate resin while maintaining the temperature in the pressure vessel at 50 ° C. or lower than the glass transition temperature of the polycarbonate resin while or after the carbon dioxide gas is pressure-injected.
【００１８】本発明において、ポリカーボネート樹脂に
炭酸ガスを溶解させる温度は、ポリカーボネート樹脂の
ガラス転移温度よりも５０℃以下、好ましくは１００℃
以下、より好ましくは室温付近（１５〜３０℃）であ
る。この温度が高過ぎると、ポリカーボネート樹脂に対
する炭酸ガスの溶解度が低過ぎて、高発泡倍率の発泡体
を得ることができない。保持時間は、ポリカーボネート
樹脂中に炭酸ガスが十分に溶解するに足る時間とする
が、通常、５時間以上、好ましくは１０時間以上、より
好ましくは２０時間以上である。炭酸ガスは、所定の温
度及び圧力下で、ポリカーボネート樹脂中に飽和する程
度まで十分に溶解させることが好ましい。In the present invention, the temperature at which carbon dioxide gas is dissolved in the polycarbonate resin is 50 ° C. or lower than the glass transition temperature of the polycarbonate resin, preferably 100 ° C.
The temperature below is more preferably around room temperature (15 to 30 ° C.). If this temperature is too high, the solubility of carbon dioxide gas in the polycarbonate resin will be too low to obtain a foam having a high expansion ratio. The holding time is set to a time sufficient for carbon dioxide gas to be sufficiently dissolved in the polycarbonate resin, but is usually 5 hours or longer, preferably 10 hours or longer, and more preferably 20 hours or longer. It is preferable that the carbon dioxide gas is sufficiently dissolved in the polycarbonate resin at a predetermined temperature and pressure until it is saturated.
【００１９】ポリカーボネート樹脂に炭酸ガスを溶解さ
せた後、圧力容器内の温度を１００℃以上に加熱する
が、加熱はできるだけ急速に行い、所望の温度に達した
時点でできるだけ保持時間を置かずに低圧域に解放して
発泡せしめることが好ましい。加熱温度は、好ましくは
１４０℃以上である。After the carbon dioxide gas is dissolved in the polycarbonate resin, the temperature in the pressure vessel is heated to 100 ° C. or higher, but the heating is performed as rapidly as possible, and when the desired temperature is reached, the holding time is not set as much as possible. It is preferable to open it in the low pressure region for foaming. The heating temperature is preferably 140 ° C or higher.
【００２０】本発明において、ポリカーボネート樹脂に
低温領域で炭酸ガスを圧入した後、加熱により温度が上
昇すると、図１からもわかるように、ポリカーボネート
樹脂に対する炭酸ガスの飽和溶解度は減少していく。し
かし、炭酸ガスがポリカーボネート樹脂の系外へ逃げる
速度が、通常の加熱方法（ヒーター等による加熱）によ
る昇温速度よりも遅いため、炭酸ガスは、高温下でポリ
カーボネート樹脂中に過飽和の状態で存在する。１００
℃以上の温度まで昇温した後、炭酸ガスが過飽和溶解状
態にあるポリカーボネート樹脂を低圧域に急激に解放す
ると、少量のガス抜けはあるものの過飽和量の炭酸ガス
が発泡に寄与するため、従来の常圧法で得られる発泡体
よりもより高発泡倍率の発泡体が得られる。In the present invention, when carbon dioxide gas is pressed into the polycarbonate resin in a low temperature range and then the temperature is raised by heating, the saturated solubility of carbon dioxide gas with respect to the polycarbonate resin decreases, as can be seen from FIG. However, since the rate at which carbon dioxide gas escapes to the outside of the polycarbonate resin is slower than the rate of temperature increase by ordinary heating methods (heating with a heater, etc.), carbon dioxide gas exists in the polycarbonate resin in a supersaturated state at high temperatures. To do. 100
When the polycarbonate resin in which the carbon dioxide gas is in a supersaturated dissolved state is rapidly released to a low pressure region after the temperature is raised to a temperature of ℃ or higher, the supersaturated amount of carbon dioxide gas contributes to foaming although there is a small amount of gas escape. A foam having a higher expansion ratio than that obtained by the normal pressure method can be obtained.
【００２１】[0021]
【実施例】以下、本発明について、実施例及び比較例を
挙げて具体的に説明するが、本発明は、これらの実施例
のみに限定されるものではない。EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
【００２２】［実施例１］ポリカーボネート樹脂（三菱
瓦斯化学社製、ユーピロンＳ−２０００、中粘度タイ
プ）１００重量部とタルク１．０重量部を、２５０℃に
設定したミキシングロールで混練後、２５０℃に設定し
た加熱プレスにより２ｍｍ厚のシートに成形した。次い
で、該シート状成形体を圧力容器内に置き、２５℃で炭
酸ガスを５０ｋｇ／ｃｍ2の圧力で注入した。２５℃に
保って、２４時間放置した後、圧力容器に巻いたバンド
ヒーターにより１５０℃まで急速に加熱した。１５０℃
に達した瞬間、減圧弁を開き、大気圧まで急激に減圧、
冷却して、ポリカーボネート樹脂発泡体を得た。かくし
て得られた発泡体は、発泡倍率が１０．５倍で、表面平
滑な発泡体であった。[Example 1] 100 parts by weight of a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Inc., Iupilon S-2000, medium viscosity type) and 1.0 part by weight of talc were kneaded with a mixing roll set at 250 ° C and then 250 A sheet having a thickness of 2 mm was formed by a heating press set at ° C. Then, the sheet-shaped molded product was placed in a pressure vessel, and carbon dioxide gas was injected at 25 ° C. at a pressure of 50 kg / cm 2 . After keeping it at 25 ° C. and leaving it for 24 hours, it was rapidly heated to 150 ° C. by a band heater wound in a pressure vessel. 150 ° C
At the moment of reaching, the pressure reducing valve was opened and the pressure was suddenly reduced to atmospheric pressure.
Upon cooling, a polycarbonate resin foam was obtained. The foam thus obtained was a foam having an expansion ratio of 10.5 and a smooth surface.
【００２３】［比較例１］ポリカーボネート樹脂（三菱
瓦斯化学社製、ユーピロンＳ−２０００、中粘度タイ
プ）１００重量部とタルク１．０重量部を、２５０℃に
設定したミキシングロールで混練後、２５０℃に設定し
た加熱プレスにより２ｍｍ厚のシートに成形した。次い
で、該シート状成形体を圧力容器内に置き、２５℃で炭
酸ガスを５０ｋｇ／ｃｍ2の圧力で注入後、直ちに、圧
力容器に巻いたバンドヒーターにより１５０℃まで急速
に加熱した。１５０℃に達した瞬間、減圧弁を開き、大
気圧まで急激に減圧、冷却して、ポリカーボネート樹脂
発泡体を得た。かくして得られた発泡体は、表面平滑で
あったが、発泡倍率が２．２倍と低かった。[Comparative Example 1] 100 parts by weight of a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Inc., Iupilon S-2000, medium viscosity type) and 1.0 part by weight of talc were kneaded with a mixing roll set at 250 ° C., and then 250 A sheet having a thickness of 2 mm was formed by a heating press set at ° C. Then, the sheet-shaped molded body was placed in a pressure vessel, carbon dioxide gas was injected at a pressure of 50 kg / cm 2 at 25 ° C., and immediately heated to 150 ° C. by a band heater wound in the pressure vessel. At the moment when the temperature reached 150 ° C., the pressure reducing valve was opened, and the pressure was rapidly reduced to atmospheric pressure and cooled to obtain a polycarbonate resin foam. The foam thus obtained had a smooth surface, but had a low expansion ratio of 2.2.
【００２４】［比較例２］ポリカーボネート樹脂（三菱
瓦斯化学社製、ユーピロンＳ−２０００、中粘度タイ
プ）１００重量部とタルク１．０重量部を、２５０℃に
設定したミキシングロールで混練後、２５０℃に設定し
た加熱プレスにより２ｍｍ厚のシートに成形した。次い
で、該シート状成形体を圧力容器内に置き、２５℃で炭
酸ガスを５０ｋｇ／ｃｍ2の圧力で注入した。２５℃に
保って、２４時間放置した後、減圧弁を開き大気圧に戻
してから、シート状成形体を圧力容器から取り出した。
しかる後、すばやくシート状成形体を１５０℃に保持し
たオイルバス中に約２０秒間浸漬して発泡させ、ポリカ
ーボネート樹脂発泡体を得た。かくして得られた発泡体
は、表面平滑であったが、発泡倍率が４．５倍と低かっ
た。[Comparative Example 2] 100 parts by weight of a polycarbonate resin (Upylon S-2000, medium viscosity type, manufactured by Mitsubishi Gas Chemical Co., Inc.) and 1.0 part by weight of talc were kneaded with a mixing roll set at 250 ° C., and then 250 A sheet having a thickness of 2 mm was formed by a heating press set at ° C. Then, the sheet-shaped molded product was placed in a pressure vessel, and carbon dioxide gas was injected at 25 ° C. at a pressure of 50 kg / cm 2 . After keeping the temperature at 25 ° C. and leaving it for 24 hours, the pressure reducing valve was opened and the pressure was returned to atmospheric pressure, and then the sheet-shaped molded product was taken out from the pressure container.
Then, the sheet-shaped molded product was quickly immersed in an oil bath kept at 150 ° C. for about 20 seconds to foam, thereby obtaining a polycarbonate resin foam. The foam thus obtained had a smooth surface, but had a low expansion ratio of 4.5.
【００２５】[0025]
【発明の効果】本発明の製造方法によれば、クリーンな
炭酸ガスを発泡剤として使用するため安全上及び環境上
の問題がなく、かつ、容易に表面平滑な高発泡倍率のポ
リカーボネート樹脂発泡体を提供することができる。本
発明によるポリカーボネート樹脂発泡体は、断熱材料、
建築材料等の多方面への適用が可能であり極めて有用で
ある。According to the production method of the present invention, since clean carbon dioxide gas is used as a foaming agent, there is no safety or environmental problem, and the surface of the polycarbonate resin foam has a high expansion ratio and is easily smoothed. Can be provided. The polycarbonate resin foam according to the present invention is a heat insulating material,
It is extremely useful as it can be applied to various fields such as building materials.
【図１】ポリカーボネート樹脂に対する炭酸ガス（４０
ｋｇ／ｃｍ2）の溶解度の温度依存性を示した図であ
る。FIG. 1 Carbon dioxide gas (40
It is the figure which showed the temperature dependence of the solubility of (kg / cm < 2 >).
Claims (1)
内に炭酸ガスを圧入すると共に、該圧力容器内の温度を
ポリカーボネート樹脂のガラス転移温度よりも５０℃以
下の温度に保持して、ポリカーボネート樹脂に炭酸ガス
を溶解させ、次いで、該圧力容器内の温度を１００℃以
上に加熱した後、低圧域に解放して発泡せしめることを
特徴とするポリカーボネート樹脂発泡体の製造方法。A carbon dioxide gas is injected into a pressure vessel containing a polycarbonate resin, and the temperature inside the pressure vessel is maintained at a temperature not higher than 50 ° C. higher than the glass transition temperature of the polycarbonate resin, so that the polycarbonate resin is carbonated. A method for producing a polycarbonate resin foam, which comprises melting a gas, heating the temperature in the pressure vessel to 100 ° C. or higher, and then releasing the gas in a low pressure region to cause foaming.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20232792A JP3167184B2 (en) | 1992-07-29 | 1992-07-29 | Method for producing polycarbonate resin foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20232792A JP3167184B2 (en) | 1992-07-29 | 1992-07-29 | Method for producing polycarbonate resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0649259A true JPH0649259A (en) | 1994-02-22 |
| JP3167184B2 JP3167184B2 (en) | 2001-05-21 |
Family
ID=16455719
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20232792A Expired - Fee Related JP3167184B2 (en) | 1992-07-29 | 1992-07-29 | Method for producing polycarbonate resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3167184B2 (en) |
-
1992
- 1992-07-29 JP JP20232792A patent/JP3167184B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3167184B2 (en) | 2001-05-21 |
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