JP3167184B2 - Method for producing polycarbonate resin foam - Google Patents
Method for producing polycarbonate resin foamInfo
- Publication number
- JP3167184B2 JP3167184B2 JP20232792A JP20232792A JP3167184B2 JP 3167184 B2 JP3167184 B2 JP 3167184B2 JP 20232792 A JP20232792 A JP 20232792A JP 20232792 A JP20232792 A JP 20232792A JP 3167184 B2 JP3167184 B2 JP 3167184B2
- Authority
- JP
- Japan
- Prior art keywords
- polycarbonate resin
- carbon dioxide
- temperature
- pressure
- foam
- 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.)
- Expired - Fee Related
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- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
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 high expansion ratio polycarbonate resin foam using 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, a thermal decomposition type chemical foaming agent is kneaded into a resin in the same manner as in the method for producing other thermoplastic resin foams. And a boiling point below the melting point of a polycarbonate resin such as an aliphatic hydrocarbon such as pentane, hexane or octane, or a fluorinated aliphatic hydrocarbon such as dichlorodifluoromethane. A gas foaming method is known in which an organic gas or a volatile liquid is injected into a molten resin and then released into a low-pressure region to cause foaming (Japanese Patent Laid-Open No. 2-261636).
【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。[0003] A foam having uniform and fine closed cells can be obtained by applying a chemical foaming agent method to a polycarbonate resin. Decomposes, discolors the foam, generates odors, and causes 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 used is an aliphatic hydrocarbon, an explosive gas is generated during the production of the foam, so that there is a danger of explosion. When the blowing agent to be used is a fluorinated aliphatic hydrocarbon, there is little danger of explosion, but it is progressing toward total elimination due to environmental problems such as destruction of the ozone layer. In order to solve such problems of the conventional method, a gas foaming method using an inert gas such as nitrogen gas or argon, or 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。[0005] Water is clean and does not cause the above-mentioned problems. However, if water is present when the polycarbonate resin is heated, the disadvantage that the carbonate bond in the polycarbonate resin is decomposed tends to occur. JP-A-53-9
No. 2874 discloses a method in which an epoxy compound is added and foaming is performed with water adsorbed on the polycarbonate in order to suppress the decomposition of the polycarbonate resin by water, but the moisture absorption of the polycarbonate is 0.15 to 0.3.
%, It is possible to obtain only a foam having a low expansion ratio of at most 2-3 times the expansion ratio.
【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。An inert gas such as nitrogen gas or argon is clean, and there is no concern about decomposition of the polycarbonate resin upon heating such as water. However, since the solubility in the polycarbonate resin is extremely low, foaming with a high expansion ratio is performed. It is difficult to get a body.
【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, carbon dioxide gas is not only clean but also acts as a plasticizer when dissolved in a polycarbonate resin, so that it can be foamed at a temperature about 90 ° C. lower than the glass transition point of the polycarbonate resin. . However, although the solubility of carbon dioxide gas in a polycarbonate resin is remarkably higher than that of an inert gas at around room temperature, the solubility is extremely reduced near the melting point of the polycarbonate resin, so that the gas is injected into the resin in a molten state. In a normal extrusion foaming method, the solubility is not so high, 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 normal 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, the pressure is returned to normal pressure, and the resin is immersed in a glycerin bath and foamed by heating. Associate professor of Kumar, Faculty of Mechanical Engineering, the University of Washington) Because of foaming under normal pressure (normal pressure method), gas escape during foaming is severe, and carbon dioxide dissolved in polycarbonate resin does not contribute to foaming effectively, and foaming with high foaming ratio It is difficult to get a body.
【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 An object of the present invention is to overcome the drawbacks of the prior art and to provide a method for producing a surface smooth, high expansion ratio polycarbonate resin foam using a clean and safe foaming agent. Is 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 intensive studies to solve the above-mentioned problems. As a result, carbon dioxide gas was injected into a pressure vessel containing a polycarbonate resin to reduce the temperature to 50 ° C. or lower than the glass transition temperature of the polycarbonate resin. Then, 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 more to bring it to a high temperature / high pressure state. It has been found that a polycarbonate resin foam having a high expansion ratio can be manufactured. 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 press-fitted into a pressure vessel containing a polycarbonate resin, and the temperature in the pressure vessel is set at 50 ° C. or lower than the glass transition temperature of the polycarbonate resin. Hold at temperature,
Dissolve carbon dioxide in polycarbonate resin, then
A method for producing a polycarbonate resin foam, characterized in that after the temperature in the pressure vessel is heated to 100 ° C. or more, the pressure is released to a low pressure range and foaming is performed.
【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。Hereinafter, the present invention will be described in detail. The solubility of carbon dioxide gas in a polycarbonate resin tends to increase from a high-temperature region to a low-temperature region (A.R.
Berens et al. ACSympos. Se
ries No. 406, 1989). FIG. 1 shows the temperature dependence of the solubility of carbon dioxide gas in the polycarbonate resin when carbon dioxide gas was injected at a pressure of 40 kg / cm 2 . As can be seen from FIG. 1, the solubility significantly decreases from around 25 ° C. to around 75 ° C. Therefore, in order to obtain a polycarbonate resin foam having a high expansion ratio, it is advantageous to dissolve carbon dioxide in the polycarbonate resin at 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 when carbon dioxide gas is injected into the polycarbonate resin at around room temperature to obtain a carbon dioxide gas-dissolved polycarbonate resin, the pressure is returned to normal pressure and the mixture is foamed by heating.
Outgassing from the surface of the polycarbonate resin is severe, and 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 making a carbon dioxide gas dissolved in a polycarbonate resin effectively contribute to foaming and obtaining a polycarbonate resin foam having a high expansion ratio. After injecting carbon dioxide gas in the vicinity and dissolving it sufficiently, do not return to normal pressure, heat it to 100 ° C or more while maintaining the high pressure state to make it a high temperature and high pressure state, then release it to the low pressure area and foam it 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 produced.
【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 the molecular structure. In particular, an aromatic polycarbonate having diphenylalkane in the molecular chain is excellent in heat resistance, weather resistance and acid resistance. Is preferred. 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 as required. Examples of these additives include fillers such as plasticizers, lubricants, antioxidants, pigments, and flame retardants, and foam control agents 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 injected into the pressure vessel containing the polycarbonate resin, and the shape of the polycarbonate resin at this time is arbitrary, such as a granular shape, a pellet shape, a sheet shape, and a rod shape. While or after pressurizing the carbon dioxide gas, the temperature in the pressure vessel is kept at 50 ° C. or lower than the glass transition temperature of the polycarbonate resin to dissolve the carbon dioxide gas in the polycarbonate resin.
【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 is dissolved in the polycarbonate resin is 50 ° C. or less, preferably 100 ° C., lower than the glass transition temperature of the polycarbonate resin.
Hereinafter, the temperature 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 is too low, and a foam having a high expansion ratio cannot be obtained. The holding time is a time sufficient for sufficiently dissolving the carbon dioxide gas in the polycarbonate resin, and is usually 5 hours or more, preferably 10 hours or more, more preferably 20 hours or more. It is preferable that the carbon dioxide gas be sufficiently dissolved in the polycarbonate resin at a predetermined temperature and pressure until the carbon dioxide gas 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 dissolving the carbon dioxide gas in the polycarbonate resin, the temperature in the pressure vessel is heated to 100 ° C. or higher. The heating is performed as quickly as possible, and when the desired temperature is reached, the holding time is set as short as possible. It is preferable that the resin be released to a low pressure range and foamed. 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 injected into the polycarbonate resin in a low temperature range and then the temperature is increased by heating, as can be seen from FIG. 1, the saturation solubility of the carbon dioxide gas in the polycarbonate resin decreases. However, the rate at which carbon dioxide escapes out of the polycarbonate resin system is slower than the rate of temperature rise by a normal heating method (heating with a heater or the like), so carbon dioxide exists in the polycarbonate resin in a supersaturated state at high temperatures. I do. 100
After the temperature is raised to a temperature of ℃ or more, when the carbon dioxide gas is rapidly released from the supersaturated dissolved state of the polycarbonate resin to a low pressure region, a small amount of gas is released, but the supersaturated carbon dioxide gas contributes to foaming. A foam having a higher expansion ratio than the foam 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 Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only 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 Company, 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 kneaded for 250 minutes. The sheet was formed into a sheet having a thickness of 2 mm by a heating press set at a temperature of ° C. Next, the sheet-shaped molded body was placed in a pressure vessel, and carbon dioxide gas was injected at 25 ° C. at a pressure of 50 kg / cm 2 . After being kept at 25 ° C. and left for 24 hours, it was rapidly heated to 150 ° C. by a band heater wound around a pressure vessel. 150 ° C
The moment it reaches, the pressure reducing valve is opened and the pressure is rapidly reduced to atmospheric pressure.
Upon cooling, a polycarbonate resin foam was obtained. The foam thus obtained was a foam having a foaming 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 Company, 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 kneaded for 250 minutes. The sheet was formed into a sheet having a thickness of 2 mm by a heating press set at a temperature of ° C. Next, the sheet-shaped molded body was placed in a pressure vessel, and after injecting carbon dioxide gas at 25 ° C. at a pressure of 50 kg / cm 2 , immediately heated to 150 ° C. by a band heater wound around the pressure vessel. The moment the temperature reached 150 ° C., the pressure reducing valve was opened, the pressure was rapidly reduced to atmospheric pressure, and the mixture was cooled to obtain a polycarbonate resin foam. The foam thus obtained had a smooth surface, but had a low expansion ratio of 2.2 times.
【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 (Iupilon S-2000, medium viscosity type, manufactured by Mitsubishi Gas Chemical Company) and 1.0 part by weight of talc were kneaded with a mixing roll set at 250 ° C., and then kneaded for 250 minutes. The sheet was formed into a sheet having a thickness of 2 mm by a heating press set at a temperature of ° C. Next, the sheet-shaped molded body was placed in a pressure vessel, and carbon dioxide gas was injected at 25 ° C. at a pressure of 50 kg / cm 2 . After being kept at 25 ° C. and left for 24 hours, the pressure reducing valve was opened to return to the atmospheric pressure, and then the sheet-shaped molded product was taken out of the pressure vessel.
Thereafter, the sheet-like molded body was quickly immersed in an oil bath maintained 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 times.
【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 a clean carbon dioxide gas is used as a foaming agent, there is no problem in terms of safety and environment, and the surface of the polycarbonate resin foam is easily smooth and has a high expansion ratio. Can be provided. The polycarbonate resin foam according to the present invention is a heat insulating material,
It can be applied to various fields such as building materials and is very useful.
【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 shows carbon dioxide (40) for a polycarbonate resin.
FIG. 3 is a diagram showing the temperature dependence of the solubility in 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。1. A carbon dioxide gas is press-fitted into a pressure vessel containing a polycarbonate resin, and the temperature in the pressure vessel is maintained at a temperature of 50 ° C. or less than the glass transition temperature of the polycarbonate resin, and the carbon dioxide is added to the polycarbonate resin. A method for producing a polycarbonate resin foam, comprising: dissolving a gas, heating the pressure in the pressure vessel to 100 ° C. or higher, and then releasing the gas to a low pressure range 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 JPH0649259A (en) | 1994-02-22 |
JP3167184B2 true 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 |
---|---|
JPH0649259A (en) | 1994-02-22 |
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