JP3910876B2 - Process for producing epoxidized low molecular weight polyphenylene ether - Google Patents

Description

【００１２】
（式中、Ｒ１、Ｒ２、Ｒ３およびＲ４は、各々独立して、水素原子、アルキル基またはハロゲン原子を表す）
【００１３】
重量平均分子量１万未満に相当する、３０℃、０．５ｇ／ｄｌのクロロホルム溶液の還元粘度は０．２ｄｌ／ｇ以下の範囲にある。ポリフェニレンエーテルの重量平均分子量が１万未満であるために、製造されるエポキシ化ポリフェニレンエーテルの架橋、硬化反応の速度は早くなり、硬化生成物の橋架け間の平均分子量は小さくなる。その結果、よりガラス転移温度が高く、耐溶剤性が向上した硬化ポリフェニレンエーテル樹脂が得られる。
【００１４】
本発明に用いるポリフェニレンエーテル重合体は、単独重合体または共重合体である。単独重合体の具体例としては、ポリ（２，６−ジメチル−１，４−フェニレンエーテル）、ポリ（２−メチルー６−フェニルー１，４−フェニレンエーテル）、ポリ（２−メチル−６−フェニルー１，４−フェニレンエーテル）、ポリ（２，６−ジクロロ−１，４−フェニレンエーテル）等が挙げられる。
ポリフェニレンエーテル共重合体の具体例としては、２，６−ジメチルフェノールと他のフェノール類（例えば２，３，６−トリメチルフェノールや２−メチル−６−メチルブチルフェノール）との共重合体等が挙げられる。これらの中で、ポリ（２，６−ジメチル−１，４−フェニレンエーテル）、２，６−ジメチルフェノールと２，３，６−トリメチルフェノールとの共重合体が好ましく、より好ましくはポリ（２，６−ジメチル−１，４−フェニレンエーテル）である。
【００１５】
本発明に用いるポリフェニレンエーテルは、固体状態を保持したままで反応に供される。固体状態としては、粉体、ペレットのいずれの状態でもよいが、粉体状のものであることが好ましい。
粉体状のポリフェニレンエーテルは、例えば、ポリフェニレンエーテルをトルエン、キシレン等の良溶媒に溶かした溶液にメタノール、アセトン等の貧溶媒を加えることによって得ることができる。ポリフェニレンエーテルを、例えば、トルエン、クロロホルム等の良溶媒に溶解させた溶液状またはポリフェニレンエーテルの融点以上における溶融状で反応に供すると、反応中に架橋、ゲル化が生じやすくなる。
粉体の状態で使用する場合、紛体の粒径は限定されないが、取扱い性の観点から１０〜１，０００μｍが好ましく、より好ましくは３０〜７００μｍの範囲である。
【００１６】
本発明に用いるエポキシ化合物は、１分子中に２個以上のオキシラン環を含む多官能エポキシ化合物である。具体例を示すと、エポキシ樹脂、１，３−ブタジエンジエポキシド、ヘキサジエンジエポキシド、オクタジエンジエポキシド、イソシアヌル酸トリグリシジルエステル、エポキシ化大豆油等が挙げられる。この中で好ましいのは、エポキシ樹脂と総称される化合物のグループから選ばれたものであり、その具体例としては、ビスフェノールＡ型エポキシ樹脂、ポリグリシジルエーテル、ノボラック型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、グリシジルエステル、グリシジルアミン、ヒダントイン型エポキシ樹脂等が挙げられる。これらの中でも最も好ましくは、化学式（２）で表されるビスフェノールＡ型樹脂または化学式（３）で表されるポリグリシジルエーテルである。
【００１７】
【化２】

【００１８】
（式中、Ｘ１及びＸ２は、芳香族炭化水素、Ａは、脂肪族炭化水素、ｎは、０または１以上の整数）
【００１９】
【化３】

【００２０】
（式中、Ｒは、脂肪族または芳香族炭化水素、ｎは、０または１以上の整数）
【００２１】
エポキシ化合物の状態は限定されないが、後記のポリフェニレンエーテルと反応させる温度および圧力条件下において、気体または液体であることが好ましい。また、エポキシ化合物をポリフェニレンエーテルの貧溶媒に溶解させた溶液をポリフェニレンエーテルと混合し、反応させてもよい。
本発明において、エポキシ化合物の添加量は、ポリフェニレンエーテルの末端フェノール基に対し、好ましくは０．１〜１０倍モル、より好ましくは０．８〜５倍モル、最も好ましくは１．１〜３倍モルの範囲である。エポキシ化合物の添加量が０．１倍モル未満では、硬化性のあるポリフェニレンエーテルが得られにくい場合があり、１０倍モルを越えると、硬化物の耐熱性や誘電特性が低下することがある。
【００２２】
ポリフェニレンエーテルと１分子内に２個以上のエポキシ基を有するエポキシ化合物を反応させる際は、前記のようにポリフェニレンエーテルは固体状態であることが必要である。
ポリフェニレンエーテルとエポキシ化合物を反応させるときの温度には制限はないが、好ましくは２０〜１５０℃、より好ましくは２０〜１００℃である。反応温度が２０℃未満では、ポリフェニレンエーテルと多官能エポキシ化合物が十分反応しないことがある。また、反応温度が１５０℃を越えると、エポキシ基開環等の副反応が増加しやすくなって、ポリフェニレンエーテルが溶融し、架橋しやすくなる傾向がある。
【００２３】
本発明は、ポリフェニレンエーテルとエポキシ化合物との反応触媒として、アミン化合物を用いる点に大きな特徴がある。
本発明で用いるアミン化合物は、分子内にアミノ基を有するものであれば限定されない。
アミン化合物としては、トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、トリ−ｎ−オクチルアミン、２−エチルヘキシルアミン、テトラメチルエチレンジアミン、Ｎ−メチルイミダゾールが例として挙げられる。中でもトリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、ブチルジメチルアミンが好ましく、これらの中で脂肪族第３級アミンがより好ましい。
【００２４】
アミン化合物以外の塩基性化合物、例えば、ブチルリチウム、ナトリウムメチラート、水酸化ナトリウム、水酸化カリウム等は、塩基性が強いため、エポキシ基の開環やエポキシ化合物の重合反応が起こり、ポリフェニレンエーテルに導入されるエポキシ基数が少なく、本発明の目的が達成されない。
本発明のアミン化合物の添加量は、原料ポリフェニレンエーテルに対して、好ましくは０．０１〜１０重量部、より好ましくは０．１〜７重量部、最も好ましくは０．１〜５重量部の範囲である。アミン化合物の添加量が０．０１重量部未満では、十分な反応促進効果が得られないことがあり、１０重量部を越えると、ポリフェニレンエーテルの色調を悪化させる場合がある。
【００２５】
本発明の製造方法により、エポキシ化合物のゲル化やエポキシ基の開環等の副反応を抑制すると共に、反応速度を飛躍的に向上させることにより、反応に供するエポキシ化合物が少量であっても、効率的にポリフェニレンエーテルと反応させて、エポキシ化ポリフェニレンエーテルを製造することができる。
本発明により製造されるエポキシ化ポリフェニレンエーテルは、エーテルの架橋体を含まず、分子鎖末端にエポキシ基を有する。また得られるエポキシ化ポリフェニレンエーテルには、ポリフェニレンエーテルの炭化物である黒色異物を含まない。本発明により製造されるエポキシ化ポリフェニレンエーテルは架橋・硬化性に優れ、その架橋体は耐薬品性に優れ、誘電率が低く、耐熱温度が高いことからプリント基板材料をはじめとする電子材料に適している。
【００２６】
このエポキシ化ポリフェニレンエーテルは、種々の硬化剤と反応して３次元網目構造を形成する。硬化剤としては、エポキシ樹脂で一般に使用されるものであれば限定されない、例えば、１分子中に複数のアミノ基、酸無水基、フェノール性ＯＨ基、チオール基を有するものが挙げられる。中でも多官能アミン化合物が好ましい。
硬化したポリフェニレンエーテルは、耐薬品性、耐熱性および誘電特性に優れるため、プリント基板、絶縁封止剤等に最適である。
【００２７】
【発明の実施の形態】
次に実施例により本発明を具体的に説明するが、本発明はこれらによってなんら限定されない。
本発明で使用する評価方法は、以下のとおりである。
（１）エポキシ化ポリフェニレンエーテルのプロトンＮＭＲ測定
反応後のエポキシ基を有するポリフェニレンエーテル粉末に残存する未反応の多官能エポキシ化合物を除去するために、反応生成物２ｇを２０ｍｌのトルエンに溶解し後、大過剰のメタノールを加えてポリマーを沈殿させる。沈殿したポリマーをろ過して分離した後、１５０℃、０．１ｍｍＨｇの条件で１時間、減圧乾燥させる。
【００２８】
上記の精製操作によって得られたエポキシ化ポリフェニレンエーテルを重クロロホルムに溶解し、２７０ＭＨｚＮＭＲにて測定を行う。ピークのケミカルシフトは、テトラメチルシランのピーク（０．００ｐｐｍ）を基準として決定する。ポリフェニレンエーテル１分子当たりのエポキシ基の数は、ポリフェニレンエーテルの芳香環３，５位プロトンに起因するピーク（６．４７ｐｐｍ）とエポキシ基に起因するピーク（２．７４，２．８９，３．３４ｐｐｍ）の面積比から求める。
【００２９】
（２）ポリフェニレンエーテルの還元粘度
反応に用いる原料ポリフェニレンエーテルを０．５ｇ／１００ｍｌのクロロホルム溶液とし、３０℃においてウベローデ粘度計を用いて測定する。
（３）ポリフェニレンエーテルの分子量測定
クロロホルムを溶剤としたＧＰＣ測定を行い、予め作成したポリスチレンの数平均分子量−溶出量の関係のグラフから算出する。
【００３０】
（４）エポキシ化ポリフェニレンエーテルの耐薬品性
エポキシ化ポリフェニレンエーテル３ｇにトリエチレンテトラミン０．５ｇを加え、よく混合させる。この混合物を熱プレス機を用いて０．５Ｍｐａ、２００℃で１０分間、加熱圧縮して硬化させた後、０．５Ｍｐａ、４０℃で１０分間冷却させる。
３．０ｇの硬化生成物を３５℃の塩化メチレンに５分間浸せき後、５分間風乾させ、秤量した。浸せき前後の質量変化率を下記式から求める。
質量変化率（％）＝｛（３．０−（浸せき後の質量））／（３．０）｝×１００
【００３１】
【実施例１】
重量平均分子量が３，５００であるポリフェニレンエーテル３．０ｇ、ビスフェノールＡ型エポキシ樹脂（旭化成エポキシ（株）製Ｇｒａｄｅ２５０）０．５ｇおよびトリ−ｎ−ブチルアミン０．０７５ｇをよく混合した後、オートクレーブに密閉し、８０℃、２時間、加熱した。
反応生成物のプロトンＮＭＲ測定を行った結果、反応後ポリマーは、１分子当たり平均１．９個のエポキシ基を有することが判った。反応後ポリマーのＧＰＣ曲線の形状は、原料ポリフェニレンエーテルのＧＰＣ曲線の形状とほぼ同じであり、架橋反応が起きていないことが確認された。反応生成物０．１ｇをクロロホルム２０ｍｌと混合したところ、完全に溶解し、透明な均一溶液が得られた。
【００３２】
反応条件及び反応生成物の評価結果を、以下の実施例および比較例と共に、表１および表２に示す。
【００３３】
【実施例２〜４】
ビスフェノールＡ型エポキシ樹脂の組成、反応温度および反応時間を変えた他は実施例１と同様に行った。
反応後のポリマーが有する１分子当たり平均のエポキシ個数を表１に示す。いずれの場合にも、反応後ポリマーのＧＰＣ曲線の形状は、原料ポリフェニレンエーテルのＧＰＣ曲線の形状とほぼ同じであった。
【００３４】
【実施例５】
エポキシ化合物をビスフェノールＡ型エポキシ樹脂の代わりに化学式（４）
【００３５】
【化４】

【００３６】
のエチレングリコールジグリシジル（Ａ）を用いた以外は、実施例１と同様に行った。
プロトンＮＭＲ測定の結果、反応後ポリマーは１分子当たり平均１．７個のエポキシ基を有することが判った。反応後ポリマーのＧＰＣ曲線の形状は原料ポリフェニレンエーテルのＧＰＣ曲線の形状とほぼ同じであり、架橋反応が起きていないことが確認された。
【００３７】
【実施例６〜１０】
エチレングリコールジグリシジルの組成、反応温度および反応時間を変えた以外は、実施例１と同様に行った。
反応後ポリマーが有する１分子当たり平均のエポキシ個数を表２に示す。いずれの場合にも反応後ポリマーのＧＰＣ曲線の形状は原料ポリフェニレンエーテルのＧＰＣ曲線の形状とほぼ同じであった。、
【００３８】
【比較例１】
触媒として、トリ−ｎ−ブチルアミンの変わりに２８重量％ナトリウムメチラートのメタノール溶液０．１ｇ加えた以外他は、実施例１と同様に行った。
【００３９】
【比較例２】
反応時間を２０時間とした以外は比較例１と同様に行った。反応生成物０．１ｇをクロロホルム２０ｍｌと混合したが、エポキシ樹脂がゲル化して生成した不溶分が多く見られた。
【００４０】
【比較例３】
エポキシ樹脂の添加量を２．０ｇとした他は比較例１と同様に行った。
【００４１】
【比較例４】
塩基性触媒として３０％水酸化ナトリウムのメタノール溶液０．１ｇを加えた以外は実施例１と同様に行った。
【００４２】
【比較例５】
反応時間を２０時間とした以外は比較例３と同様に行った。反応生成物０．１ｇをクロロホルム２０ｍｌと混合したが、エポキシ樹脂がゲル化して生成した不溶分が多く見られた。
【００４３】
【比較例６】
塩基性触媒を全く加えない他は実施例１と同様に行った。
【００４４】
【比較例７】
反応時間を２０時間とした他は比較例５と同様に行った。
【００４５】
【比較例８】
重量平均分子量４３，０００のポリフェニレンエーテルを用いた他は実施例２と同様に行った。
【００４６】
【比較例９】
実施例１で用いたポリフェニレンエーテル２．７Ｋｇとグリシジルアクリレート３００ｇを１０Ｌの容器に入れ、窒素気流下、８０℃でトルエン５．１Ｋｇに溶解した。ベンゾイルパーオキシド４５ｇをトルエン９００ｇに溶解させた溶液を容器内に徐々に滴下した。滴下後、８０℃で５時間、加熱攪拌しながら反応を行った。
【００４７】
反応後終了後、反応溶液を１００Ｌの攪拌機付きの容器に移し、ここで攪拌しながら６０Ｋｇのメタノールを徐々に加えていくとスラリー状になるので、これをろ過、減圧乾燥して、白色粉末２．５Ｋｇを得た。この粉末の一部を上記、評価方法１に従て精製し、ＮＭＲ解析を行ったが、エポキシ基に起因するピークは見られなかった。
【００４８】
【表１】

【００４９】
【表２】

【００５０】
【発明の効果】
本発明によると、エポキシ化合物のゲル化やエポキシ基の開環等の副反応を抑制すると共に、反応速度を飛躍的に向上させることにより、反応に供するエポキシ化合物が少量であっても、効率的にポリフェニレンエーテルと反応させて、エポキシ化ポリフェニレンエーテルを製造することができる。この方法により得られるエポキシ化ポリフェニレンエーテルは、高分子鎖に導入されたエポキシ基数が多く、耐薬品性、耐熱性、誘電特性に優れる硬化物を与える。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an epoxidized polyphenylene ether suitable for electric and electronic materials such as printed boards and insulating sealants.
[0002]
[Prior art]
Polyphenylene ether is a material suitable for printed circuit boards and insulating sealants for electrical and electronic equipment because of its high heat resistance and excellent dielectric properties. On the other hand, it is a halogen-based solvent such as trichlorethylene, and aromatics such as toluene. There is a drawback that the solvent resistance to the group solvents is low. Therefore, in the use of electronic materials, chemical resistance is improved by crosslinking and curing polyphenylene ether without impairing low dielectric properties and high heat resistance.
[0003]
As methods for crosslinking and curing polyphenylene ether, for example, JP-A-6-206984, JP-B-6-17457, and US Pat. No. 5,834,565 disclose compositions of polyphenylene ether and polyepoxide compounds. ing. According to these methods, since a large amount of unreacted polyepoxide that does not participate in the reaction with polyphenylene ether remains, the heat resistance of polyphenylene ether is impaired.
[0004]
Regarding polyphenylene ethers having an epoxy group, Japanese Patent Publication No. 63-503392, Japanese Patent Publication No. 7-5818, Japanese Patent Publication No. 3-6185, and International Publication No. 00/52074 pamphlet include polyphenylene ether and glycidyl methacrylate. And polyphenylene ether having an epoxy group obtained by reacting an epoxy compound containing a double bond and an epoxy group in the molecule such as glycidyl acrylate and the like. However, the polyphenylene ether having an epoxy group obtained by these methods cannot be crosslinked or cured because the number of epoxy groups effectively introduced into the polymer chain is small.
[0005]
As means for solving the above problems, the present inventor examined a method of reacting an epoxy compound having a plurality of epoxy groups in the molecule with a solid polyphenylene ether, but in the case where a basic catalyst is not added, the reaction is performed. Since it takes a long time to reach the epoxy addition rate required to give a cured product having a low speed and sufficient chemical resistance, there is a problem that the economics of the reaction process is extremely low. In addition, when alcoholate or sodium hydroxide is used, side reactions such as epoxy ring opening and gelation of the epoxy compound occur, and the epoxy group cannot be effectively introduced unless the epoxy compound is added excessively to the polyphenylene ether. There was a problem.
[0006]
[Problems to be solved by the invention]
The present invention suppresses side reactions such as gelation of epoxy compounds and ring opening of epoxy groups when reacting polyphenylene ether with an epoxy compound having two or more epoxy groups in one molecule, and reaction rate. It is an object of the present invention to provide a method for producing epoxidized polyphenylene ether by efficiently reacting with polyphenylene ether even if a small amount of epoxy compound is subjected to the reaction.
[0007]
Furthermore, the present invention provides an epoxidized polyphenylene ether that is easily crosslinked and gives a cured product having excellent heat resistance, dielectric properties and chemical resistance, and is useful for electrical and electronic materials such as printed circuit boards and insulating sealants. It aims to provide a method.
[0008]
[Means for Solving the Problems]
As a result of diligent investigations on polyphenylene ethers having an epoxy group, the present inventors have found that when an amine compound is used as a catalyst in the reaction of a polyphenylene ether having a weight average molecular weight of less than 10,000 with a polyfunctional epoxy compound, no catalyst is used. The reaction rate is accelerated compared with the addition, and side reactions such as epoxy group ring opening and gelation of the epoxy compound are suppressed, so that an epoxy group is efficiently introduced into the chain end of the polyphenylene ether, Furthermore, the obtained polyphenylene ether was found to be excellent in curability and gives a cured product having excellent heat resistance, dielectric properties, and chemical resistance by curing, and the present invention has been completed.
[0009]
That is, the present invention is as follows.
(1) When a polyphenylene ether having a weight average molecular weight of less than 10,000 and an epoxy compound having two or more epoxy groups in one molecule are reacted while the polyphenylene ether is maintained in a solid state, an amine compound is used as a catalyst. A method for producing an epoxidized polyphenylene ether, characterized in that it is used.
(2) The method for producing an epoxidized polyphenylene ether according to (1), wherein the amine compound is an aliphatic tertiary amine.
(3) The method for producing an epoxidized polyphenylene ether according to (1) or (2), wherein the reaction temperature is 20 to 150 ° C.
(4) The method for producing an epoxidized polyphenylene ether according to any one of (1) to (3), wherein the reaction temperature is 20 to 100 ° C.
[0010]
Hereinafter, the present invention will be described in detail.
The polyphenylene ether used in the present invention is a polymer or copolymer having the structure of the chemical formula (1) and a weight average molecular weight of less than 10,000.
[0011]
[Chemical 1]

[0012]
(Wherein R1, R2, R3 and R4 each independently represents a hydrogen atom, an alkyl group or a halogen atom)
[0013]
The reduced viscosity of a chloroform solution at 30 ° C. and 0.5 g / dl, corresponding to a weight average molecular weight of less than 10,000, is in the range of 0.2 dl / g or less. Since the weight average molecular weight of the polyphenylene ether is less than 10,000, the speed of crosslinking and curing reaction of the epoxidized polyphenylene ether to be produced increases, and the average molecular weight between the bridges of the cured product decreases. As a result, a cured polyphenylene ether resin having a higher glass transition temperature and improved solvent resistance can be obtained.
[0014]
The polyphenylene ether polymer used in the present invention is a homopolymer or a copolymer. Specific examples of the homopolymer include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), and poly (2-methyl-6-phenyl-). 1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether) and the like.
Specific examples of polyphenylene ether copolymers include copolymers of 2,6-dimethylphenol and other phenols (for example, 2,3,6-trimethylphenol and 2-methyl-6-methylbutylphenol). It is done. Among these, poly (2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferable, and poly (2 , 6-dimethyl-1,4-phenylene ether).
[0015]
The polyphenylene ether used in the present invention is subjected to the reaction while maintaining a solid state. The solid state may be either powder or pellet, but is preferably in powder form.
The powdered polyphenylene ether can be obtained, for example, by adding a poor solvent such as methanol or acetone to a solution obtained by dissolving polyphenylene ether in a good solvent such as toluene or xylene. When polyphenylene ether is subjected to the reaction in the form of a solution obtained by dissolving polyphenylene ether in a good solvent such as toluene or chloroform or in a molten state above the melting point of polyphenylene ether, crosslinking and gelation are likely to occur during the reaction.
When used in a powder state, the particle size of the powder is not limited, but is preferably 10 to 1,000 μm, more preferably 30 to 700 μm from the viewpoint of handleability.
[0016]
The epoxy compound used in the present invention is a polyfunctional epoxy compound containing two or more oxirane rings in one molecule. Specific examples include epoxy resin, 1,3-butadiene diepoxide, hexadiene diepoxide, octadiene diepoxide, isocyanuric acid triglycidyl ester, epoxidized soybean oil, and the like. Preferred among these are those selected from the group of compounds generically referred to as epoxy resins, and specific examples thereof include bisphenol A type epoxy resins, polyglycidyl ethers, novolac type epoxy resins, and bisphenol F type epoxy resins. Glycidyl ester, glycidyl amine, hydantoin type epoxy resin and the like. Among these, the bisphenol A type resin represented by the chemical formula (2) or the polyglycidyl ether represented by the chemical formula (3) is most preferable.
[0017]
[Chemical 2]

[0018]
(Wherein X1 and X2 are aromatic hydrocarbons, A is an aliphatic hydrocarbon, and n is 0 or an integer of 1 or more)
[0019]
[Chemical 3]

[0020]
(Wherein R is an aliphatic or aromatic hydrocarbon, n is 0 or an integer of 1 or more)
[0021]
The state of the epoxy compound is not limited, but is preferably a gas or liquid under the temperature and pressure conditions for reacting with the polyphenylene ether described below. Alternatively, a solution obtained by dissolving an epoxy compound in a poor solvent of polyphenylene ether may be mixed with polyphenylene ether and reacted.
In the present invention, the addition amount of the epoxy compound is preferably 0.1 to 10 times mol, more preferably 0.8 to 5 times mol, and most preferably 1.1 to 3 times the terminal phenol group of the polyphenylene ether. The range of moles. If the addition amount of the epoxy compound is less than 0.1 times mol, it may be difficult to obtain a curable polyphenylene ether. If it exceeds 10 times mol, the heat resistance and dielectric properties of the cured product may be deteriorated.
[0022]
When the polyphenylene ether is reacted with an epoxy compound having two or more epoxy groups in one molecule, the polyphenylene ether needs to be in a solid state as described above.
Although there is no restriction | limiting in the temperature when making polyphenylene ether and an epoxy compound react, Preferably it is 20-150 degreeC, More preferably, it is 20-100 degreeC. When the reaction temperature is less than 20 ° C., the polyphenylene ether and the polyfunctional epoxy compound may not sufficiently react. On the other hand, when the reaction temperature exceeds 150 ° C., side reactions such as epoxy group ring opening tend to increase, and the polyphenylene ether tends to melt and easily crosslink.
[0023]
The present invention is greatly characterized in that an amine compound is used as a reaction catalyst for polyphenylene ether and an epoxy compound.
The amine compound used in the present invention is not limited as long as it has an amino group in the molecule.
Examples of the amine compound include trimethylamine, triethylamine, tripropylamine, tributylamine, tri-n-octylamine, 2-ethylhexylamine, tetramethylethylenediamine, and N-methylimidazole. Of these, trimethylamine, triethylamine, tripropylamine, tributylamine, and butyldimethylamine are preferable, and among these, aliphatic tertiary amines are more preferable.
[0024]
Basic compounds other than amine compounds, such as butyllithium, sodium methylate, sodium hydroxide, potassium hydroxide, etc., are strong in basicity, so that ring opening of epoxy groups and polymerization reaction of epoxy compounds occur, resulting in polyphenylene ether. The number of epoxy groups introduced is small and the object of the present invention is not achieved.
The addition amount of the amine compound of the present invention is preferably in the range of 0.01 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, most preferably 0.1 to 5 parts by weight with respect to the raw material polyphenylene ether. It is. When the addition amount of the amine compound is less than 0.01 parts by weight, a sufficient reaction promoting effect may not be obtained, and when it exceeds 10 parts by weight, the color tone of the polyphenylene ether may be deteriorated.
[0025]
By the production method of the present invention, while suppressing side reactions such as gelation of epoxy compounds and ring opening of epoxy groups, and by dramatically improving the reaction rate, even if a small amount of epoxy compound is subjected to the reaction, Epoxidized polyphenylene ether can be produced by efficiently reacting with polyphenylene ether.
The epoxidized polyphenylene ether produced according to the present invention does not include a crosslinked product of ether, and has an epoxy group at the end of the molecular chain. Further, the obtained epoxidized polyphenylene ether does not contain black foreign substances which are carbides of polyphenylene ether. Epoxidized polyphenylene ether produced according to the present invention is excellent in cross-linking / curing properties, and its cross-linked product is excellent in chemical resistance, low dielectric constant, and high heat resistance, so it is suitable for electronic materials such as printed circuit board materials. ing.
[0026]
This epoxidized polyphenylene ether reacts with various curing agents to form a three-dimensional network structure. The curing agent is not limited as long as it is generally used for epoxy resins, and examples thereof include those having a plurality of amino groups, acid anhydride groups, phenolic OH groups, and thiol groups in one molecule. Of these, polyfunctional amine compounds are preferred.
Cured polyphenylene ether is excellent in chemical resistance, heat resistance, and dielectric properties, and is optimal for printed circuit boards and insulating sealants.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited at all by these.
The evaluation method used in the present invention is as follows.
(1) Proton NMR measurement of epoxidized polyphenylene ether In order to remove the unreacted polyfunctional epoxy compound remaining in the polyphenylene ether powder having an epoxy group after the reaction, 2 g of the reaction product was dissolved in 20 ml of toluene, A large excess of methanol is added to precipitate the polymer. The precipitated polymer is separated by filtration and then dried under reduced pressure for 1 hour at 150 ° C. and 0.1 mmHg.
[0028]
The epoxidized polyphenylene ether obtained by the above purification operation is dissolved in deuterated chloroform and measured by 270 MHz NMR. The chemical shift of the peak is determined based on the peak of tetramethylsilane (0.00 ppm). The number of epoxy groups per molecule of polyphenylene ether is such that the peak due to the aromatic ring 3,5-position proton of polyphenylene ether (6.47 ppm) and the peak due to epoxy group (2.74, 2.89, 3.34 ppm). ) Area ratio.
[0029]
(2) The raw polyphenylene ether used for the reductive viscosity reaction of polyphenylene ether is made into a 0.5 g / 100 ml chloroform solution and measured at 30 ° C. using an Ubbelohde viscometer.
(3) Molecular weight measurement of polyphenylene ether GPC measurement using chloroform as a solvent is performed, and the molecular weight is calculated from a graph of the number average molecular weight-elution amount relationship of polystyrene prepared in advance.
[0030]
(4) Chemical resistance of epoxidized polyphenylene ether 0.5 g of triethylenetetramine is added to 3 g of epoxidized polyphenylene ether and mixed well. This mixture is cured by heating and compression at 0.5 Mpa and 200 ° C. for 10 minutes using a hot press machine, and then cooled at 0.5 Mpa and 40 ° C. for 10 minutes.
3.0 g of the cured product was immersed in methylene chloride at 35 ° C. for 5 minutes, then air-dried for 5 minutes and weighed. The mass change rate before and after immersion is obtained from the following formula.
Mass change rate (%) = {(3.0- (mass after immersion)) / (3.0)} × 100
[0031]
[Example 1]
After thoroughly mixing 3.0 g of polyphenylene ether having a weight average molecular weight of 3,500, 0.5 g of bisphenol A type epoxy resin (Grade 250 manufactured by Asahi Kasei Epoxy Co., Ltd.) and 0.075 g of tri-n-butylamine, the mixture is sealed in an autoclave. And heated at 80 ° C. for 2 hours.
As a result of proton NMR measurement of the reaction product, it was found that the polymer after reaction had an average of 1.9 epoxy groups per molecule. The shape of the GPC curve of the polymer after the reaction was almost the same as the shape of the GPC curve of the starting polyphenylene ether, and it was confirmed that no crosslinking reaction occurred. When 0.1 g of the reaction product was mixed with 20 ml of chloroform, it was completely dissolved and a transparent uniform solution was obtained.
[0032]
Table 1 and Table 2 show the reaction conditions and the evaluation results of the reaction products together with the following examples and comparative examples.
[0033]
[Examples 2 to 4]
The same procedure as in Example 1 was performed except that the composition, reaction temperature, and reaction time of the bisphenol A type epoxy resin were changed.
Table 1 shows the average number of epoxies per molecule of the polymer after the reaction. In any case, the shape of the GPC curve of the polymer after the reaction was almost the same as the shape of the GPC curve of the starting polyphenylene ether.
[0034]
[Example 5]
An epoxy compound is represented by the chemical formula (4) instead of a bisphenol A type epoxy resin.
[0035]
[Formula 4]

[0036]
This was carried out in the same manner as in Example 1 except that ethylene glycol diglycidyl (A) was used.
As a result of proton NMR measurement, it was found that the polymer after reaction had an average of 1.7 epoxy groups per molecule. The shape of the GPC curve of the polymer after the reaction was almost the same as the shape of the GPC curve of the starting polyphenylene ether, and it was confirmed that no crosslinking reaction occurred.
[0037]
Examples 6 to 10
It carried out like Example 1 except having changed the composition of ethylene glycol diglycidyl, reaction temperature, and reaction time.
Table 2 shows the average number of epoxies per molecule of the polymer after the reaction. In any case, the shape of the GPC curve of the polymer after the reaction was almost the same as the shape of the GPC curve of the starting polyphenylene ether. ,
[0038]
[Comparative Example 1]
The same procedure as in Example 1 was carried out except that 0.1 g of a 28 wt% sodium methylate methanol solution was added as a catalyst instead of tri-n-butylamine.
[0039]
[Comparative Example 2]
The reaction was performed in the same manner as in Comparative Example 1 except that the reaction time was 20 hours. Although 0.1 g of the reaction product was mixed with 20 ml of chloroform, a lot of insoluble matter produced by gelation of the epoxy resin was observed.
[0040]
[Comparative Example 3]
The same procedure as in Comparative Example 1 was performed except that the amount of the epoxy resin added was 2.0 g.
[0041]
[Comparative Example 4]
The same procedure as in Example 1 was performed except that 0.1 g of a 30% sodium hydroxide methanol solution was added as a basic catalyst.
[0042]
[Comparative Example 5]
The same procedure as in Comparative Example 3 was performed except that the reaction time was 20 hours. Although 0.1 g of the reaction product was mixed with 20 ml of chloroform, a lot of insoluble matter produced by gelation of the epoxy resin was observed.
[0043]
[Comparative Example 6]
The same procedure as in Example 1 was carried out except that no basic catalyst was added.
[0044]
[Comparative Example 7]
The reaction was performed in the same manner as in Comparative Example 5 except that the reaction time was 20 hours.
[0045]
[Comparative Example 8]
The same procedure as in Example 2 was performed except that polyphenylene ether having a weight average molecular weight of 43,000 was used.
[0046]
[Comparative Example 9]
2.7 kg of polyphenylene ether and 300 g of glycidyl acrylate used in Example 1 were placed in a 10 L container and dissolved in 5.1 kg of toluene at 80 ° C. under a nitrogen stream. A solution in which 45 g of benzoyl peroxide was dissolved in 900 g of toluene was gradually dropped into the container. After dropping, the reaction was carried out at 80 ° C. for 5 hours with heating and stirring.
[0047]
After completion of the reaction, the reaction solution is transferred to a 100 L container equipped with a stirrer, and 60 Kg of methanol is gradually added with stirring. As a result, the slurry is filtered and dried under reduced pressure. Obtained 5 kg. A part of this powder was purified according to the above evaluation method 1 and subjected to NMR analysis, but no peak attributable to the epoxy group was observed.
[0048]
[Table 1]

[0049]
[Table 2]

[0050]
【The invention's effect】
According to the present invention, by suppressing side reactions such as gelation of epoxy compounds and ring opening of epoxy groups, and by dramatically improving the reaction rate, even if a small amount of epoxy compound is used for the reaction, it is efficient. Can be reacted with polyphenylene ether to produce epoxidized polyphenylene ether. The epoxidized polyphenylene ether obtained by this method has a large number of epoxy groups introduced into the polymer chain, and gives a cured product excellent in chemical resistance, heat resistance and dielectric properties.

Claims (4)

An amine compound is used as a catalyst when a polyphenylene ether having a weight average molecular weight of less than 10,000 is reacted with an epoxy compound having two or more epoxy groups in one molecule while the polyphenylene ether is maintained in a solid state. A process for producing an epoxidized polyphenylene ether characterized by The method for producing an epoxidized polyphenylene ether according to claim 1, wherein the amine compound is an aliphatic tertiary amine. The method for producing an epoxidized polyphenylene ether according to claim 1 or 2, wherein the reaction temperature is 20 to 150 ° C. The method for producing an epoxidized polyphenylene ether according to any one of claims 1 to 3, wherein the reaction temperature is 20 to 100 ° C.