JP3506543B2 - Method for producing reaction-curable resin foam - Google Patents
Method for producing reaction-curable resin foamInfo
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- JP3506543B2 JP3506543B2 JP23214895A JP23214895A JP3506543B2 JP 3506543 B2 JP3506543 B2 JP 3506543B2 JP 23214895 A JP23214895 A JP 23214895A JP 23214895 A JP23214895 A JP 23214895A JP 3506543 B2 JP3506543 B2 JP 3506543B2
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Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、断熱材、防音材、
給排紙用ロール、緩衝材、化粧用パフ、各種成形体の軽
量化等に用いられる反応硬化性樹脂発泡体の製造方法に
関する。
【０００２】
【従来の技術】熱可塑性樹脂発泡体を製造する方法とし
ては、発泡剤を用いて化学反応によって気体を生じさせ
る化学発泡と、気体を直接樹脂に混合する物理発泡とが
一般的に知られている。反応硬化性樹脂の分野では、も
っぱら硬化反応と化学発泡を同時に行うことにより発泡
体を得る方法が採られてきた。そして、この方法によっ
て得られる気泡のサイズは、平均径 100μm 程度が下限
であり、気泡径も不均一であった。
【０００３】
【発明が解決しようとする課題】しかし、上記した反応
硬化性樹脂発泡体の製造方法は、発泡と硬化が同時に進
行するために、樹脂中に気泡が均一に分散した発泡体を
安定して得ることは容易ではなく、硬化速度と発泡速度
を極めて高度に制御する必要があった。さらに、このよ
うにして得られる気泡のサイズは 100μm 程度が下限で
あり、より細かいレベルの気泡を有する発泡体を得るこ
とは不可能であった。このような課題に鑑み、本発明の
目的は、硬化速度と発泡速度を高度に制御することな
く、樹脂中に気泡が均一に分散した反応硬化性樹脂発泡
体を安定して得ることができ、さらに気泡のサイズが均
一で 100μm 程度以下の、非常に細かいレベルの気泡を
有する反応硬化性樹脂発泡体の製造方法を提供すること
にある。
【０００４】
【課題を解決するための手段】本発明は上記課題を解決
してなり、本発明の反応硬化性樹脂発泡体の製造方法
は、未硬化あるいは半硬化状態の反応硬化性樹脂に、常
温常圧で気体である物質を、その臨界温度以上かつ臨界
圧力以上で分散させた後、圧力を10kgf/cm2/sec.以上の
速度で低下させて未硬化あるいは半硬化状態で発泡さ
せ、その後硬化させることを特徴とする。本発明の態様
は、前記反応硬化性樹脂に前記物質を分散させるに際
し、該物質をその臨界温度未満、加圧下にて、次工程で
温度を上昇させた際に圧力が前記物質の臨界圧力以上と
なる量を注入し、次いで温度を前記物質の臨界温度以上
とし、かつ前記反応硬化性樹脂が完全には硬化しない温
度及び時間内で反応硬化性樹脂に前記物質を分散させる
ことにある。本発明の他の態様は、前記反応硬化性樹脂
の硬化に際し、硬化温度条件の異なる２種以上の硬化剤
を使用し、これら硬化剤の少なくともｌ種を残して反応
硬化性樹脂の半硬化を行い、前記物質を注入し、分散さ
せた後、圧力を低下させて半硬化状態で発泡させ、その
後加熱して、未反応の硬化剤による硬化を行うことにあ
る。
【０００５】本発明者らは、樹脂中に気泡が均一に分散
した反応硬化性樹脂発泡体を安定して得るためには、物
理発泡によって微細な気泡を形成すればよいことに着眼
し、その方法、条件、材料等について種々検討を重ねた
結果、物理的作用によって微細な気泡が均一に分散して
なる反応硬化性樹脂発泡体が得られる方法を見出した。
即ち、発泡容器内部の反応硬化性樹脂材料中に、常温常
圧では気体である物質（以下、単に気体物質という）
を、その臨界温度以上で、臨界圧力以上に加圧して注入
し、反応硬化性樹脂の未硬化または半硬化状態（以下、
半硬化状態を含めて未硬化状態という）を維持して、分
散させた後、圧力を10kgf/cm2/sec.以上の速度で低下さ
せることによつて発泡させる。その後硬化を行うことに
よって微細な気泡が均一に分散した反応硬化性樹脂発泡
体が得られる。
【０００６】さらに、未硬化状態の反応硬化性樹脂に、
気体物質を、その臨界温度未満で加圧して注入する。こ
のときの注入量は、次の分散工程で温度を上昇させたと
きに示す圧力が、この気体物質の臨界圧力以上となる量
である。次いで温度を気体物質の臨界温度以上とし、か
つ前記反応硬化性樹脂が完全には硬化しない温度及び時
間内で反応硬化性樹脂に気体物質を分散させる。つま
り、閉ざされた装置内の反応硬化性樹脂中に、気体物質
を、その臨界温度未満で加圧して注入し、次に温度を気
体物質の臨界温度以上に上げ、圧力を気体物質の臨界圧
力以上として気体物質の分散を行う。その後、圧力を10
kgf/cm2/sec.以上の速度で低下することによつて発泡さ
せる。その後硬化を行うことによって反応硬化性樹脂発
泡体が得られる。このようにすることによって、高圧ポ
ンプ等を用いることなく、気体物質を樹脂中に臨界温度
以上かつ臨界圧力以上で分散させることができる。
【０００７】なお、気体物質をその臨界温度未満で加圧
して注入するのはできるだけ多くの気体物質を樹脂中に
注入するためであり、温度を気体物質の臨界温度以上に
上げ、圧力を気体物質の臨界圧力以上として気体物質の
分散を行うのは、樹脂中への気体物質の拡散を促進する
ためである。さらに圧力を10kgf/cm2/sec.以上の速度で
低下させるのは、 100μm 以下の微細な気泡を形成させ
るためであり、10 kgf/cm2/sec. 未満の速度での低下で
は気泡径は 100μm 以上、著しくは 500μm 以上とな
り、所望の発泡体を得ることはできない。また、圧力を
低下させる速度の上限は特に限定されないが、工業的に
は 500kgf/cm2/sec.以下で設計するのが実用的である。
【０００８】また、硬化温度条件の異なる２種以上の硬
化剤を使用して、硬化を２段階で行い、最初の硬化で半
硬化状態とし、気体物質を注入、分散し発泡させた後、
さらに加熱して最終硬化を行うことができる。例えば、
シリコーン樹脂の発泡体を得る場合、分解温度の異なる
２種以上のパーオキサイドを用い、気体物質を樹脂材料
中に加圧注入後、温度、圧力をそれぞれ気体物質の臨界
温度以上、臨界圧力以上に上げ、反応硬化性樹脂材料中
に気体物質を分散させ、使用した硬化剤のうちの少なく
とも１種は硬化作用を生じない温度で、反応硬化性樹脂
を硬化させて半硬化状態とし、次に圧力を10kgf/cm2/se
c.以上の速度で低下して発泡させ、その後加熱して、反
応せずに残った硬化剤の硬化を行うようにすれば、発泡
時の樹脂の粘度を任意に調整することができ、発泡状態
の制御及び成形が容易であり、樹脂中に極めて微細な気
泡を分散させてなる樹脂発泡体を得ることができる。
【０００９】本発明に用いられる反応硬化性樹脂として
は、ウレタン樹脂、アクリル樹脂、エポキシ樹脂、シリ
コーン樹脂等の公知のものが挙げられる。なお、これら
のうち、ウレタン樹脂、シリコーン樹脂は硬化物が弾性
を有しており、特にシリコーン樹脂は耐熱性、耐久性に
優れるため様々な用途に使用することができ、好まし
い。
【００１０】これらの樹脂を硬化させる硬化剤には、主
剤と硬化剤とからなるもの、あるいは単独で硬化反応を
起こすものがある。例えば、ウレタン樹脂の場合は、イ
ソシアネート基を持つ化合物と、アルコール、アミン、
水等の活性水素基を持つ化合物とからなる。アクリル樹
脂の場合は、UV、電子線、放射線等によって硬化反応を
起こすメチルメタクリレート、エチルメタクリレート等
のアクリル酸エステルからなる。エポキシ樹脂の場合
は、エポキシ基を持つ化合物と、活性水素基を持つ化合
物、特にはポリアミン、ポリアミド、ポリカルボン酸無
水物、ポリスルフィド、ポリメルカプタン、ジシアンジ
アミド、三フッ化ホウ素コンプレックス、フェノール樹
脂等とからなる。さらに、シリコーン樹脂の場合は、シ
ロキサン結合を持つ高分子化合物とパーオキサイドとか
らなるもの、又はシロキサン結合を持つ高分子化合物
と、珪素原子に直結した水素原子を１分子中に少なくと
も２個以上持つハイドロジェンポリオルガノシロキサン
と、白金系触媒とからなるもの等が挙げられる。なお、
これらの樹脂には、必要に応じて、難燃剤、老化防止
剤、耐候性向上剤、耐衝撃性向上剤、補強剤、着色剤、
導電性付与剤等の各種添加剤を添加することは、任意で
ある。
【００１１】本発明に使用される気体物質としては、水
素、ヘリウム、窒素、酸素、ネオン、アルゴン、二酸化
炭素、メタン、エタン、プロパン、ブタン、エチレン、
プロピレン、フロン等及びこれらの混合物が例示され
る。特に二酸化炭素が、化学的に安定であリ、臨界温度
が常温に近く本発明への適用が容易であることから好ま
しい。
【００１２】本発明に用いられる装置としては、バッチ
式の耐圧容器、バッチ式の密閉型混練装置、押出混練
機、射出成形機等が使用可能であるが、生産性、作業
性、成形体の寸法精度等に優れることから押出混練機ま
たは射出成形機を用いることが好ましい。押出混練機を
用いる場合は、押出混練機中で、未硬化状態の反応硬化
性樹脂に、気体物質を、その臨界圧力以上かつ臨界温度
以上で分散し、ダイスから押し出すことにより圧力を10
kgf/cm2/sec.以上の速度で低下させて発泡、成形を行
い、最後に硬化させるか、さらには、押出混練機の第一
のゾーンで、未硬化状態の反応硬化性樹脂に、気体物質
を、その臨界温度未満で加圧して、次工程で温度を上昇
させた際に圧力が気体物質の臨界圧力以上となる量を注
入し、次いで第二のゾーンで温度を気体物質の臨界温度
以上とし、かつ前記反応硬化性樹脂が完全には硬化しな
い温度及び時間内で反応硬化性樹脂に気体物質を分散
し、ダイスから押し出すことにより圧力を10kgf/cm2/se
c.以上の速度で低下させて発泡、成形を行い、最後に硬
化させることにより遂行される。
【００１３】射出成形機を用いる場合は、未硬化状態の
反応硬化性樹脂に、気体物質を、その臨界圧力以上かつ
臨界温度以上で分散し、圧力を10kgf/cm2/sec.以上の速
度で低下させて未硬化状態で発泡させ、このものを射出
成形機に供給し、金型内に射出して成形、硬化を行う方
法、又は射出成形機の材料投入部で、未硬化状態の反応
硬化性樹脂と共に、気体物質を、その臨界圧力以上かつ
臨界温度以上で分散し、計量部を経て金型内に射出する
ことにより圧力を10kgf/cm2/sec.以上の速度で低下させ
て発泡、成形を行い、硬化させるか、さらには、射出成
形機の材料投入部で、未硬化状態の反応硬化性樹脂に、
気体物質を、その臨界温度以下で、加圧して、材料送り
部及び計量部で温度を上昇させた際に圧力が前記物質の
臨界圧力以上となる量を注入、分散し、温度を前記物質
の臨界温度以上とし、かつ前記反応硬化性樹脂が完全に
は硬化しない温度及び時間内で材料送り及び計量を行
い、金型内に射出することにより圧力を10kgf/cm2/sec.
以上の速度で低下させて発泡、成形を行い、硬化させる
ことにより遂行される。
【００１４】反応硬化性用樹脂を硬化させる方法として
は、加熱、電子線照射、ＵＶ照射、放射線照射等が例示
され、反応硬化性樹脂の種類より適宜選択することが可
能であるが、安全性、汎用性を考慮すると加熱、または
電子線照射による方法が好ましい。なお、本発明におい
ては樹脂が発泡した後に硬化反応を行うため、発泡した
未硬化状態の反応硬化性樹脂が断熱性を有するものとな
るので、高周波加熱による方法か、電子線照射による方
法を採用し、熱伝導性に影響を受けず、内部まで均一に
硬化する方法とすることが最も好ましい。
【００１５】
【本発明の実施の形態】本発明の反応硬化性樹脂発泡体
の製造方法は、未硬化状態の反応硬化性樹脂材料中に、
気体物質をその臨界圧力以上かつ臨界温度以上で分散さ
せた後、圧力を所定の速度、即ち10kgf/cm2/sec.以上の
速度で低下させることにより、反応硬化性樹脂中に均一
に分散した気体物質が気泡化し、無数の微細な気泡とな
って可塑状態の反応硬化性樹脂中に均一に発泡する。以
下、さらに本発明の実施の形態を実施例をもって説明す
る。
【００１６】
【実施例】以下に本発明の具体的実施例を挙げる。
［実施例１］バッチ式耐圧容器（容量500ml ）に、シリ
コーンゴムコンパウンド「KE153-U」（信越化学製、商
品名）100 重量部と、加硫剤「C-2 」（信越化学製、商
品名）3 重量部とからなる混練物を、 2mm×20mm×20mm
の形状に成形したものを供給して蓋をした。容器を氷で
冷却しながら、二酸化炭素（臨界温度31℃，臨界圧力7
5.6kgf/cm2 ）を容器内に圧力60kgf/cm2 、温度12℃で2
00g注入した。温度を60℃まで上昇させると、圧力は 12
5kgf/cm2 に達した。この状態を10分間保持した後、バ
ルブを開放し、3.04秒で大気圧まで圧力を降下させた。
次に、これを150℃のオーブンで30分間加熱して加硫
し、さらに、200 ℃で4 時間熱処理して本発明の反応硬
化性樹脂発泡体を得た。この時の発泡倍率は1.83倍で、
気泡は均一に分散し、その平均サイズは66μmであっ
て、その標準偏差は 6.4μm であった。
【００１７】［実施例２］シリコーンゴムコンパウンド
「KE550-U 」（信越化学製、商品名）100 重量部と、加
硫剤「C-2 」（信越化学製、商品名）0.5 重量部及び加
硫剤「C-3 」（信越化学製、商品名）2.5 重量部とから
なる混練物を、 2mm×20mm×20mmの形状に成形し、温度
を 120℃としたオーブンに10分間入れ半加硫を行った。
次に、これをバッチ式耐圧容器に入れて蓋をした。容器
を氷で冷却しながら、二酸化炭素を容器内に圧力60kgf/
cm2 、温度12℃で200g注入した。温度を60℃まで上昇さ
せると、圧力は 125kgf/cm2 に達した。この状態を10分
間保持した後、バルブを開放し、3.11秒で大気圧まで圧
力を降下させた。次に、これを180 ℃のオーブンで30分
間加熱して加硫し、さらに、210 ℃で4 時間熱処理して
本発明の反応硬化性樹脂発泡体を得た。この時の発泡倍
率は 1.6倍で、気泡は均一に分散し、その平均サイズは
16μmであって、その標準偏差は 1.5μm であった。
【００１８】
【発明の効果】以上の結果から明らかなように本発明に
よれば、硬化速度と発泡速度を高度に制御することな
く、気泡が均一に分散した反応硬化性樹脂発泡体を安定
して得ることができ、さらに気泡のサイズが100 μm 程
度以下の、非常に細かいレベルの気泡を有する発泡体を
得ることができる。本発明を実施することにより製造の
コストダウン、製品の高性能化を図ることができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating material, a sound insulating material,
The present invention relates to a method for producing a reaction curable resin foam used for paper supply / discharge rolls, cushioning materials, cosmetic puffs, weight reduction of various molded articles, and the like. 2. Description of the Related Art As a method for producing a thermoplastic resin foam, chemical foaming in which a gas is generated by a chemical reaction using a foaming agent, and physical foaming in which a gas is directly mixed with a resin are generally used. Are known. In the field of reaction-curable resins, a method of obtaining a foam by exclusively performing a curing reaction and chemical foaming at the same time has been adopted. The lower limit of the size of the bubble obtained by this method was about 100 μm in average diameter, and the bubble diameter was also non-uniform. [0003] However, in the above-mentioned method for producing a reaction-curable resin foam, since foaming and curing proceed simultaneously, a foam in which bubbles are uniformly dispersed in a resin can be stably prepared. However, it was not easy to obtain the composition, and it was necessary to control the curing rate and the foaming rate at a very high level. Furthermore, the lower limit of the size of the cells thus obtained is about 100 μm, and it has not been possible to obtain a foam having a finer level of cells. In view of such problems, an object of the present invention is to obtain a reaction-curable resin foam in which bubbles are uniformly dispersed in a resin without highly controlling the curing speed and the foaming speed, It is still another object of the present invention to provide a method for producing a reaction-curable resin foam having a very fine level of bubbles having a uniform bubble size of about 100 μm or less. [0004] The present invention has solved the above-mentioned problems, and the method for producing a reaction-curable resin foam of the present invention is directed to a reaction-curable resin in an uncured or semi-cured state. After dispersing a substance that is a gas at normal temperature and normal pressure, above its critical temperature and above its critical pressure, the pressure is reduced at a rate of 10 kgf / cm 2 / sec. Or more and foamed in an uncured or semi-cured state, After that, it is cured. An embodiment of the present invention provides a method for dispersing the substance in the reaction-curable resin, wherein the pressure is lower than the critical temperature of the substance, under pressure, and when the temperature is increased in the next step, the pressure is equal to or higher than the critical pressure of the substance. And then dispersing the substance in the reaction-curable resin within a temperature and within a time at which the reaction-curable resin is not completely cured, while maintaining the temperature at or above the critical temperature of the substance. Another embodiment of the present invention uses two or more types of curing agents having different curing temperature conditions when curing the reaction-curable resin, and semi-cures the reaction-curable resin while leaving at least one of these curing agents. Then, after injecting and dispersing the substance, the pressure is reduced to cause foaming in a semi-cured state, followed by heating to cure with an unreacted curing agent. The present inventors have focused on the fact that in order to stably obtain a reaction-curable resin foam in which bubbles are uniformly dispersed in a resin, fine bubbles must be formed by physical foaming. As a result of various studies on methods, conditions, materials, and the like, they have found a method for obtaining a reaction-curable resin foam in which fine bubbles are uniformly dispersed by physical action.
That is, a substance that is a gas at normal temperature and normal pressure (hereinafter, simply referred to as a gaseous substance) in the reaction-curable resin material inside the foaming container.
Above the critical temperature, pressurized above the critical pressure and injected, the uncured or semi-cured state of the reaction curable resin (hereinafter, referred to as
After dispersing while maintaining the uncured state including the semi-cured state), foaming is performed by reducing the pressure at a rate of 10 kgf / cm 2 / sec. Or more. After curing, a reaction-curable resin foam in which fine bubbles are uniformly dispersed is obtained. Further, the reaction-curable resin in an uncured state is
The gaseous substance is injected under pressure below its critical temperature. The injection amount at this time is an amount at which the pressure indicated when the temperature is increased in the next dispersion step is equal to or higher than the critical pressure of the gaseous substance. Next, the gaseous substance is dispersed in the reaction-curable resin within a temperature and a time at which the temperature is equal to or higher than the critical temperature of the gaseous substance and the reaction-curable resin is not completely cured. In other words, a gaseous substance is injected into the reaction-curable resin in a closed apparatus by pressurizing it at a temperature lower than its critical temperature, then raising the temperature above the critical temperature of the gaseous substance, and increasing the pressure to the critical pressure of the gaseous substance. The gas substance is dispersed as described above. Then increase the pressure to 10
It foams by lowering at a speed of more than kgf / cm 2 / sec. Thereafter, curing is performed to obtain a reaction-curable resin foam. In this manner, the gaseous substance can be dispersed in the resin at a critical temperature or higher and a critical pressure or higher without using a high-pressure pump or the like. The purpose of injecting a gaseous substance under pressure below its critical temperature is to inject as much gaseous substance into the resin as possible, so that the temperature is raised above the critical temperature of the gaseous substance and the pressure is increased. The reason why the gaseous substance is dispersed at the critical pressure or higher is to promote the diffusion of the gaseous substance into the resin. Further, the pressure is reduced at a rate of 10 kgf / cm 2 / sec. Or more in order to form fine bubbles of 100 μm or less, and at a rate of less than 10 kgf / cm 2 / sec. The thickness is 100 μm or more, particularly 500 μm or more, and a desired foam cannot be obtained. The upper limit of the rate of pressure reduction is not particularly limited, but it is practically practical to design the pressure at 500 kgf / cm 2 / sec or less. [0008] Further, using two or more kinds of curing agents having different curing temperature conditions, curing is performed in two stages, the first curing is made a semi-cured state, and a gaseous substance is injected, dispersed and foamed.
Further curing can be performed by final heating. For example,
When a silicone resin foam is obtained, two or more types of peroxides having different decomposition temperatures are used, and after a gaseous substance is injected under pressure into a resinous material, the temperature and pressure are respectively increased to the critical temperature of the gaseous substance or more and the critical pressure or more. Raise, disperse the gaseous substance in the reaction-curable resin material, cure the reaction-curable resin to a semi-cured state at a temperature at which at least one of the curing agents used does not cause a curing action, and then pressurize. the 10kgf / cm 2 / se
c.By lowering and foaming at the above speed and then heating, if the curing agent remaining without reacting is cured, the viscosity of the resin at the time of foaming can be adjusted arbitrarily, It is easy to control and mold the state, and it is possible to obtain a resin foam in which extremely fine bubbles are dispersed in the resin. As the reaction curable resin used in the present invention, known resins such as urethane resin, acrylic resin, epoxy resin, silicone resin and the like can be mentioned. Of these, urethane resins and silicone resins are preferred because the cured products have elasticity, and silicone resins are particularly excellent in heat resistance and durability and can be used for various applications. [0010] Curing agents for curing these resins include those comprising a main agent and a curing agent, or those which alone cause a curing reaction. For example, in the case of a urethane resin, a compound having an isocyanate group, an alcohol, an amine,
And a compound having an active hydrogen group such as water. In the case of an acrylic resin, it is made of an acrylic acid ester such as methyl methacrylate or ethyl methacrylate which causes a curing reaction by UV, electron beam, radiation or the like. In the case of an epoxy resin, a compound having an epoxy group and a compound having an active hydrogen group, in particular, a polyamine, a polyamide, a polycarboxylic anhydride, a polysulfide, a polymercaptan, a dicyandiamide, a boron trifluoride complex, a phenol resin, and the like. Become. Further, in the case of a silicone resin, a polymer composed of a polymer compound having a siloxane bond and a peroxide, or a polymer compound having a siloxane bond, and having at least two hydrogen atoms directly bonded to silicon atoms in one molecule Examples include those comprising a hydrogen polyorganosiloxane and a platinum-based catalyst. In addition,
In these resins, if necessary, flame retardants, anti-aging agents, weather resistance improvers, impact resistance improvers, reinforcing agents, coloring agents,
It is optional to add various additives such as a conductivity-imparting agent. The gaseous substances used in the present invention include hydrogen, helium, nitrogen, oxygen, neon, argon, carbon dioxide, methane, ethane, propane, butane, ethylene,
Examples include propylene, chlorofluorocarbon, and the like, and mixtures thereof. In particular, carbon dioxide is preferable because it is chemically stable and has a critical temperature close to room temperature and is easily applied to the present invention. As the apparatus used in the present invention, a batch-type pressure vessel, a batch-type closed kneading apparatus, an extrusion kneading machine, an injection molding machine and the like can be used. It is preferable to use an extrusion kneader or an injection molding machine because of its excellent dimensional accuracy and the like. When using an extrusion kneader, in an extrusion kneader, a gaseous substance is dispersed in an uncured reaction-curable resin at a critical temperature or higher and a critical temperature or higher, and the pressure is increased by extruding from a die.
Reduce foaming and molding at a speed of not less than kgf / cm 2 / sec., and finally cure, or further, in the first zone of the extrusion kneader, unreacted reaction curable resin The substance is pressurized below its critical temperature and injected in such an amount that when the temperature is increased in the next step, the pressure is equal to or higher than the critical pressure of the gaseous substance, then the temperature is raised in the second zone to the critical temperature of the gaseous substance. The above, and the reaction curable resin is not completely cured at a temperature and time within which the gaseous substance is dispersed in the reaction curable resin, and is extruded from a die to increase the pressure to 10 kgf / cm 2 / se.
c. Performed by lowering at the above speed, foaming and molding, and finally curing. When an injection molding machine is used, a gaseous substance is dispersed in an uncured reaction-curable resin at a temperature higher than its critical pressure and a temperature higher than its critical pressure, and the pressure is increased at a speed of 10 kgf / cm 2 / sec. Reduced and foamed in an uncured state, supply this to an injection molding machine, inject it into a mold and perform molding and curing, or at the material injection part of the injection molding machine, reaction curing in an uncured state Along with the water-soluble resin, the gaseous substance is dispersed at a temperature higher than the critical pressure and higher than the critical temperature, and the pressure is lowered at a speed of 10 kgf / cm 2 / sec. Perform molding and cure, or further, at the material input section of the injection molding machine, to the uncured reaction curable resin,
The gaseous substance is pressurized below its critical temperature, and when the temperature is increased in the material feeding section and the metering section, the amount at which the pressure becomes greater than or equal to the critical pressure of the substance is injected and dispersed, and the temperature of the substance is reduced. The material is fed and weighed at a temperature and time during which the reaction-curable resin is not completely cured at a temperature not lower than the critical temperature and the pressure is set to 10 kgf / cm 2 / sec by injecting into a mold.
It is performed by lowering at the above speed, foaming, molding and curing. Examples of the method for curing the reaction curable resin include heating, electron beam irradiation, UV irradiation, and radiation irradiation, and can be appropriately selected from the types of the reaction curable resins. Considering versatility, a method using heating or electron beam irradiation is preferable. In the present invention, since the curing reaction is performed after the resin is foamed, the foamed uncured reaction-curable resin has heat insulating properties. Therefore, a method using high-frequency heating or a method using electron beam irradiation is employed. However, it is most preferable to adopt a method of uniformly curing the inside without being affected by the thermal conductivity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for producing a reaction-curable resin foam of the present invention comprises the steps of:
After dispersing the gaseous substance at or above its critical pressure and at or above the critical temperature, the pressure is reduced at a predetermined rate, that is, 10 kgf / cm 2 / sec. The gaseous substance is bubbled and becomes innumerable fine bubbles, which are uniformly foamed in the reaction-curable resin in a plastic state. Hereinafter, embodiments of the present invention will be further described with reference to examples. EXAMPLES Specific examples of the present invention will be described below. Example 1 100 parts by weight of a silicone rubber compound "KE153-U" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and a vulcanizing agent "C-2" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) were placed in a batch pressure vessel (capacity: 500 ml). Name) Kneaded material consisting of 3 parts by weight, 2mm x 20mm x 20mm
The product molded in the shape of was supplied and covered. While cooling the container with ice, carbon dioxide (critical temperature 31 ° C, critical pressure 7
5.6 kgf / cm 2 ) in a container at a pressure of 60 kgf / cm 2 and a temperature of 12 ° C.
00g was injected. When the temperature is raised to 60 ° C, the pressure is 12
5 kgf / cm 2 was reached. After maintaining this state for 10 minutes, the valve was opened, and the pressure was reduced to atmospheric pressure in 3.04 seconds.
Next, this was heated in an oven at 150 ° C. for 30 minutes for vulcanization, and further heat-treated at 200 ° C. for 4 hours to obtain a reaction-curable resin foam of the present invention. The expansion ratio at this time is 1.83 times,
The bubbles were uniformly dispersed, their average size was 66 μm, and their standard deviation was 6.4 μm. Example 2 100 parts by weight of silicone rubber compound "KE550-U" (trade name, manufactured by Shin-Etsu Chemical), 0.5 parts by weight of vulcanizing agent "C-2" (trade name, manufactured by Shin-Etsu Chemical) and A kneaded product consisting of 2.5 parts by weight of a sulfurizing agent "C-3" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is molded into a shape of 2 mm x 20 mm x 20 mm, and placed in an oven at a temperature of 120 ° C for 10 minutes for half vulcanization. Was done.
Next, this was put into a batch-type pressure-resistant container and capped. While cooling the container with ice, a pressure of 60 kgf /
200 g was injected at cm 2 and a temperature of 12 ° C. When the temperature was raised to 60 ° C., the pressure reached 125 kgf / cm 2 . After maintaining this state for 10 minutes, the valve was opened, and the pressure was reduced to atmospheric pressure in 3.11 seconds. Next, this was heated in an oven at 180 ° C. for 30 minutes for vulcanization, and further heat-treated at 210 ° C. for 4 hours to obtain a reaction-curable resin foam of the present invention. The expansion ratio at this time is 1.6 times, the bubbles are uniformly dispersed, and the average size is
It was 16 μm and its standard deviation was 1.5 μm. As is apparent from the above results, according to the present invention, it is possible to stabilize a reaction-curable resin foam in which bubbles are uniformly dispersed without highly controlling the curing speed and the foaming speed. Further, a foam having a very fine level of cells having a cell size of about 100 μm or less can be obtained. By implementing the present invention, manufacturing costs can be reduced and products can have higher performance.
Claims (1)
樹脂に、常温常圧で気体である物質を、その臨界温度以
上かつ臨界圧力以上で分散させた後、圧力を10kgf/cm2/
sec. 以上の速度で低下させて未硬化あるいは半硬化状
態で発泡させ、その後硬化させることを特徴とする反応
硬化性樹脂発泡体の製造方法。 【請求項２】 前記反応硬化性樹脂に前記物質を分散さ
せるに際し、該物質をその臨界温度未満、加圧下にて、
次工程で温度を上昇させた際に圧力が前記物質の臨界圧
力以上となる量を注入し、次いで温度を前記物質の臨界
温度以上とし、かつ前記反応硬化性樹脂が完全には硬化
しない温度及び時間内で反応硬化性樹脂に前記物質を分
散させることを特徴とする請求項ｌに記載の反応硬化性
樹脂発泡体の製造方法。 【請求項３】 前記反応硬化性樹脂の硬化に際し、硬化
温度条件の異なる２種以上の硬化剤を使用し、これら硬
化剤の少なくともｌ種を残して反応硬化性樹脂の半硬化
を行い、前記物質を注入し、分散させた後、圧力を低下
させて半硬化状態で発泡させ、その後加熱して、未反応
の硬化剤による硬化を行うことを特徴とする請求項ｌ又
は２に記載の反応硬化性樹脂発泡体の製造方法。(57) [Claim 1] A substance which is a gas at normal temperature and normal pressure is dispersed in an uncured or semi-cured reaction-curable resin at a temperature higher than its critical temperature and higher than the critical pressure. , the pressure 10kgf / cm 2 /
A method for producing a reaction-curable resin foam, characterized in that the foam is reduced in an uncured or semi-cured state at a speed of at least sec. and then cured. 2. When dispersing the substance in the reaction-curable resin, the substance is heated below its critical temperature under pressure.
When the temperature is increased in the next step, the amount at which the pressure becomes equal to or higher than the critical pressure of the substance is injected, and then the temperature is set to be equal to or higher than the critical temperature of the substance, and the temperature at which the reaction-curable resin is not completely cured and The method for producing a reaction-curable resin foam according to claim 1, wherein the substance is dispersed in the reaction-curable resin within a period of time. 3. When curing the reaction-curable resin, two or more curing agents having different curing temperature conditions are used, and the reaction-curable resin is semi-cured while leaving at least one of these curing agents. The reaction according to claim 1 or 2, wherein after the substance is injected and dispersed, the pressure is reduced to cause foaming in a semi-cured state, followed by heating to perform curing with an unreacted curing agent. A method for producing a curable resin foam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23214895A JP3506543B2 (en) | 1995-09-11 | 1995-09-11 | Method for producing reaction-curable resin foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23214895A JP3506543B2 (en) | 1995-09-11 | 1995-09-11 | Method for producing reaction-curable resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0977898A JPH0977898A (en) | 1997-03-25 |
| JP3506543B2 true JP3506543B2 (en) | 2004-03-15 |
Family
ID=16934752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23214895A Expired - Lifetime JP3506543B2 (en) | 1995-09-11 | 1995-09-11 | Method for producing reaction-curable resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3506543B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9395668B2 (en) | 2014-10-09 | 2016-07-19 | Synztec Co., Ltd. | Pressure-applying fixing roller and fixing device |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5897503B2 (en) * | 2007-06-04 | 2016-03-30 | 日東電工株式会社 | Resin foam and method for producing the same |
| JP5003905B2 (en) * | 2008-04-16 | 2012-08-22 | 信越化学工業株式会社 | Method for producing silicone rubber foam |
| KR101144305B1 (en) * | 2008-12-15 | 2012-05-11 | 주식회사 엘지화학 | Process for producing polyurethane foam and porous polishing pad prepared by using it |
| CN116333480B (en) * | 2023-02-13 | 2026-04-21 | 江苏中科聚合新材料产业技术研究院有限公司 | A high-temperature resistant polymer foam material and its preparation method |
-
1995
- 1995-09-11 JP JP23214895A patent/JP3506543B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9395668B2 (en) | 2014-10-09 | 2016-07-19 | Synztec Co., Ltd. | Pressure-applying fixing roller and fixing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0977898A (en) | 1997-03-25 |
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