JP2004010683A - Resin composition and cured material thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a resin composition causing excellent flame retardance, water resistance and heat resistance of its cured material. <P>SOLUTION: The curable resin composition comprises a benzoxazine ring-containing compound and a biphenylnovolak type phenol resin having 5,000-20,000 weight-average molecular weight. <P>COPYRIGHT: (C)2004,JPO

Description

【０００７】
（式中ｍは繰り返し数を表す。）
で表されるフェノール樹脂であって、重量平均分子量が５０００〜２００００であるフェノール樹脂を含有することを特徴とする樹脂組成物、
（２）（ｃ）エポキシ樹脂を含有する請求項１記載の樹脂組成物。
（３）
（ｃ）成分が下記式（２）
【０００８】
【化７】

（式中ｎは繰り返し数を表す。）
【０００９】
である上記（２）記載の樹脂組成物、
（４）成分（ａ）が下記式（３）
【００１０】
【化８】

【００１１】
若しくは下記式（４）
【００１２】
【化９】

【００１３】
（式中、Ｘは単結合、または下記式（５）
【００１４】
【化１０】

【００１５】
で、示される構造のいずれかを表す。）
で表される化合物である上記（１）〜（３）のいずれか１項に記載の樹脂組成物、
（５）硬化促進剤を含有する上記（１）〜（４）のいずれか１項に記載の樹脂組成物、
（６）上記（１）〜（５）のいずれか１項に記載の樹脂組成物を硬化してなる硬化物、
を提供するものである。
【００１６】
【発明の実施の形態】
本発明で用いる成分（ａ）は、ベンゾオキサジン環を有する化合物（ベンゾオキサジン環含有化合物という）であれば特に制限はなく、例えば特開２００１−２８８３３９号公報にジヒドロベンゾオキサジン環を有する化合物として記載された化合物等を使用することができる。ベンゾオキサジン環含有化合物は、加熱に伴い開環重合しフェノール樹脂の架橋剤として作用する他、開環重合に伴いフェノール性水酸基を有する化合物となるため、エポキシ樹脂の硬化剤として作用する。
本発明においては、ベンゾオキサジン環含有化合物のうち上記式（３）又は（４）で表される化合物は粘度が低く作業性に優れるため好ましい。
【００１７】
本発明において成分（ａ）と、成分（ｂ）の配合比率は、重量比で通常５：９５〜９５〜５であり、好ましくは１０：９０〜９０：１０である。
【００１８】
本発明において用いる成分（ｂ）は、式（１）で表され、重合平均分子量が５０００〜２００００程度のものであれば特に制限はない。式（１）のフェノール樹脂の構造自体は公知であり、例えば特開平８−１４３６４８号公報、特開２００１−４００５３号公報、特開平１１−１４０１６６号公報等に記載されている。式（１）の構造を有するフェノール樹脂は、例えばビス（メトキシメチル）ビフェニル、ビス（クロロメチル）ビフェニル、ビス（ヒドロキシメチル）ビフェニル等のビフェニル誘導体とフェノールを酸触媒の存在下に反応させ得ることができるが、このような一般的な製法で得られるフェノール樹脂の重量平均分子量は５００〜１５００程度である。
本発明において使用する成分（ｂ）は、このような低分子量のフェノール樹脂を前記したようなビフェニル誘導体で鎖延長して得ることができる。
【００１９】
具体的には、低分子量のフェノール樹脂のフェノール性水酸基１当量に対し、ビフェニル誘導体を通常０．０１〜０．４５モル、好ましくは０．０５〜０．４モルの範囲内で加え縮合反応を行う。
【００２０】
縮合反応において、ビフェニル誘導体がビス（クロロメチル）ビフェニルである場合は、触媒は特に必要ではないが、ビス（メトキシメチル）ビフェニル又はビス（ヒドロキシメチル）ビフェニル等の場合は酸触媒を用いる。用い得る酸触媒としては塩酸、硫酸、パラトルエンスルホン酸などが挙げられるが、特にパラトルエンスルホン酸が好ましい。酸触媒の使用量としてはビフェニル誘導体１モルに対し通常０．００１〜０．１重量部、好ましくは０．００５〜０．０５重量部である。
【００２１】
縮合反応は生成物の分子量が大きくなるにつれ粘度も上昇するため溶剤を使用してもよい。用い得る溶剤としては沸点が１００〜２００℃で酸に対して不活性であるものが好ましい。具体的な例としてはプロピレングリコールモノメチルエーテル、プロピレングリコールモノプロピルエーテル、プロピレングリコールモノブチルエーテル等が挙げられる。溶剤は、生成物の重量に対して通常２〜２００重量％、好ましくは３〜１５０重量％となるよう反応系に添加する。
反応はビフェニル誘導体が完全に消失するまで行う。反応温度としては通常１００〜１８０℃、反応時間としては通常１〜２０時間である。
【００２２】
尚、原料にビス（クロロメチル）ビフェニルを使用した場合、反応器の一方から窒素を吹き込み、他方から副反応物として生成する塩酸ガスをチューブなどで取り出す。取り出された塩酸は水酸化ナトリウム水溶液などのアルカリ性水溶液中にバブリングしてトラップすることが好ましい。
【００２３】
反応終了後、系中に必要により更に前記溶剤、好ましくはアルキルフェノールを加えて、樹脂分を溶解する。ここで用い得るアルキルフェノールの例としてはフェノール、オルソクレゾール、メタクレゾール、パラクレゾール、キシレノール等が挙げられるが、水に対する溶解性や融点の面からクレゾール、特にオルソクレゾールが好ましい。溶剤は、全溶剤量が生成物の重量に対して通常３０〜３００重量％、好ましくは５０〜２５０重量％程度となる量使用する。
【００２４】
溶剤添加後、系内を５０〜１００℃に保ち、撹拌下で温水を加える。温水の量としては生成物の重量に対し通常１０〜３００重量％、好ましくは２０〜２００重量％である。充分撹拌を行った後、静置し、水層（上層）と油層（下層）に分離する。水層が中性を示すまでこの水洗工程を繰り返す。通常、必要な水洗回数は２〜１０回である。水洗終了後、加熱減圧下において溶剤を留去することにより目的とするの高分子量のフェノール樹脂を得ることが出来る。尚、式（１）において、ｍは繰り返し数を表すが、通常５〜２５、好ましくは６〜２０である。また、成分（ｂ）のフェノール樹脂の軟化点としては通常６０〜１４０℃である。水酸基当量は通常２００〜２６０ｇ／ｅｑである。
【００２５】
本発明の樹脂組成物は、成分（ａ）と成分（ｂ）だけでも熱硬化性を示すが、更に（ｃ）成分としてエポキシ樹脂を使用することもできる。使用できるエポキシ樹脂としては、ノボラック型エポキシ樹脂、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビフェニル型エポキシ樹脂、ジシクロペンタジエンフェノール共縮合型エポキシ樹脂などが挙げられ、市販品が入手可能である。中でも硬化物の難燃性が向上するという点から上記式（２）で表されるエポキシ樹脂が好ましい。
また、成分（ｃ）は、その軟化点が通常５０〜８０℃であるものが好ましく、エポキシ当量が通常２６０〜２９０ｇ／ｅｑであるものが好ましい。
【００２６】
本発明の樹脂組成物において、成分（ｃ）の配合比率は、成分（ａ）：成分（ｃ）の重量比で通常５：９５〜９５〜５であり、好ましくは１０：９０〜９０：１０である。
【００２７】
またエポキシ樹脂を含有する本発明の樹脂組成物においては、硬化促進剤を使用しても差し支えない。用い得る硬化促進剤の具体例としては２−メチルイミダゾール、２−エチルイミダゾール、２−エチル−４−メチルイミダゾール等のイミダゾ−ル類、２−（ジメチルアミノメチル）フェノール、１，８−ジアザ−ビシクロ（５，４，０）ウンデセン−７等の第３級アミン類、トリフェニルホスフィン等のホスフィン類、オクチル酸スズ等の金属化合物等が挙げられる。硬化促進剤は樹脂１００重量部に対して０．０１〜５．０重量部が必要に応じ用いられる。
【００２８】
本発明の樹脂組成物は必要により無機充填材を含有しうる。用いうる無機充填材の具体例としてはシリカ、アルミナ、タルク等が挙げられる。無機充填材は本発明の樹脂組成物中において０〜９０重量％を占める量が用いられる。更に本発明の樹脂組成物には、シランカップリング剤、ステアリン酸、パルミチン酸、ステアリン酸亜鉛、ステアリン酸カルシウム等の離型剤、顔料等の種々の配合剤を添加することができる。
【００２９】
本発明の樹脂組成物は、各成分を均一に混合することにより得られる。本発明の樹脂組成物は従来知られている方法と同様の方法で容易にその硬化物とすることができる。例えばベンゾオキサジン環を有する化合物、式（１）のフェノール樹脂及び／またはエポキシ樹脂並びに必要により、硬化促進剤、無機充填材及び配合剤とを必要に応じて押出機、ニ−ダ、ロ−ル等を用いて均一になるまで充分に混合して樹脂組成物を得、その樹脂組成物を溶融後注型あるいはトランスファ−成型機などを用いて成型し、さらに８０〜２００℃で２〜１０時間加熱することにより硬化物を得ることができる。
【００３０】
また本発明の樹脂組成物をトルエン、キシレン、アセトン、メチルエチルケトン、メチルイソブチルケトン等の溶剤に溶解させワニスを調製し、銅箔、ポリイミドフィルム、ＰＥＴ（ポリエチレンテレフタレート）フィルム等の上に塗布し加熱下で溶剤を蒸発させ硬化させることによりフィルム状の硬化物を得ることも出来る。また、得られたワニスをガラス繊維、カ−ボン繊維、ポリエステル繊維、ポリアミド繊維、アルミナ繊維、紙などの基材に含浸させ加熱半乾燥して得たプリプレグを熱プレス成型して硬化物を得ることもできる。この際の溶剤は、樹脂組成物と該溶剤の混合物中で通常１０〜７０重量％、好ましくは１５〜７０重量％を占める量を用いる。
【００３１】
【実施例】
次に本発明を実施例、比較例により更に具体的に説明するが、以下において部は特に断わりのない限り重量部である。
【００３２】
合成例１
温度計、冷却管、撹拌器を取り付けたフラスコにフェノール３１５部を加え８０℃に昇温した後、４，４’−ビス（クロロメチル）ビフェニル２５１部を撹拌下で４時間かけて分割して仕込み、更に１．５時間撹拌した後、トリポリリン酸３．７部を加え３０分撹拌し中和した後、加熱減圧下で未反応フェノールを除去しフェノール樹脂３２６部を得た。得られた樹脂の軟化点は７１℃、水酸基当量は２１４ｇ／ｅｑであった。
【００３３】
温度計、分留管、冷却管、撹拌器、冷却管の先端に容器内に発生した塩酸ガスを系外に追い出せるようシリコンチューブを取り付けたフラスコに窒素ガスパージを施しながら、得られた樹脂２１４部に対し、４，４’−ビス（クロロメチル）ビフェニル５６，３部、プロピレングリコールモノメチルエーテル５０．８部を加え窒素を吹き込みながら撹拌下で１３０℃まで昇温し、溶解させた。ゲルパーミエーションクロマトグラフィー分析により反応を追跡し４，４’−ビス（クロロメチル）ビフェニルが反応開始後４時間で完全に消失したことを確認した後、更に２時間撹拌を続け反応を終了させた。
【００３４】
系内の温度を９０℃まで冷却しオルソクレゾールを２５４部、温水を５００部加え、８０℃で１０分撹拌した。静置後、上層からサイホン排水により水層を除去した。次いで、温水を５００部加え撹拌、静置、分離という同様の操作を更に２回繰り返した。３回目の水洗工程において、水層が中性になったため、油層からエバポレーターを用いて加熱減圧下でオルソクレゾールを留去したところ式（１）で表されるフェノール樹脂２４１部が得られた（式（１）のｍ＝８．９（平均値））。得られた樹脂（以下、フェノール樹脂（Ｂ）という）のＧＰＣによる重量平均分子量は１２４００、軟化点は１３５．２℃、水酸基当量は２５４ｇ／ｅｑであった。
【００３５】
実施例１、２　比較例１、２
下記式（６）
【００３６】
【化１１】

【００３７】
で表されるベンゾオキサジン環を有する化合物（Ａ）と合成例１で得られたフェノール樹脂（Ｂ）、フェノールノボラック（明和化成（株）製、Ｈ−１；軟化点８３℃、水酸基当量１０６ｇ／ｅｑ、重量平均分子量９６０）、前記式（２）で表されるエポキシ樹脂（Ｃ）（日本化薬（株）製ＮＣ−３０００；軟化点５８℃、エポキシ当量２７５ｇ／ｅｑ）及び溶剤としてメチルエチルケトン（ＭＥＫ）を表１に示される組成で配合してワニスを調製した。次いで各ワニスをガラスクロスに含浸し、１３０℃で７分間乾燥して、樹脂分約４５％のプリプレグを得た。このプリプレグを８枚と両面に厚さ５ミクロンの銅箔を重ね、１７０℃、圧力４０Ｋｇ／ｍ^２で１時間プレス成形して、厚さ１．６ｍｍの銅張りガラス積層板を作成した。これらの積層板の難燃性、吸水率、及びガラス転移点を下記の方法に基づき試験した結果を表１に示した。
【００３８】
難燃性
ＵＬ−９４に従って測定
吸湿性
４０℃、９０％ＨＲ　１００時間後の吸湿率
ガラス転移点
熱機械測定装置（ＴＭＡ）：真空理工（株）製　ＴＭ−７０００
昇温速度：２℃／ｍｉｎ．
【００３９】

【００４０】
【発明の効果】
本発明の樹脂組成物は、従来一般的に使用されてきた熱硬化性樹脂組成物と比較して難燃性、耐水性、耐熱性に優れた硬化物を与える。
従って、本発明の樹脂組成物は電気・電子材料、成型材料、注型材料、積層材料、塗料、接着剤、レジスト、光学材料などの広範囲の用途にきわめて有用である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin composition which provides a cured product having excellent flame retardancy, water resistance and toughness and has excellent workability.
[0002]
[Prior art]
A thermosetting compound having a benzoxazine ring is generally known to have halogen-free and antimony-free flame retardancy and to give a cured product having excellent water resistance. For example, JP-A-10-204255 describes a thermosetting resin composition containing a thermosetting resin having a dihydrobenzodioxane ring and an epoxy resin having an isocyanuric ring, and the thermosetting resin composition is made of glass. It is described that a cured product having a high transition temperature, a low water absorption rate and further excellent flame retardancy is provided. JP-A-10-251380 discloses a thermosetting resin composition containing a thermosetting resin having a dihydrobenzodioxane ring, a halogenated phenol compound and an epoxy resin. It is described that the product gives a cured product having a high glass transition temperature, a low water absorption and a further excellent flame retardancy. Further, JP-A-2000-7901 describes a thermosetting resin composition containing a resin having a dihydrobenzodioxane ring and an epoxidized polybutadiene, and the thermosetting resin composition has good moisture resistance and heat resistance. It is described that when applied to a laminate for printed wiring boards, a cured product capable of suppressing the occurrence of interlayer cracks is provided. JP-A-11-140278 and JP-A-11-140278 describe a resin composition for semiconductor encapsulation containing a thermosetting resin having a dihydrobenzodioxane ring, an epoxy resin and a phenol resin, It is described that this resin composition gives a cured product having improved flame retardancy without deteriorating various properties required for semiconductor encapsulation. JP-A-2001-288339 describes a flame-retardant epoxy resin composition containing a compound having a dihydrobenzodioxane ring, an epoxy resin, a curing agent and an inorganic filler. It is described that a cured product having excellent properties is provided.
[0003]
[Problems to be solved by the invention]
However, when a compound having a benzoxazine ring is thermally cured, the curing temperature is usually as high as 200 ° C. or more, and there is a problem in workability. Although the cured product is excellent in flame retardancy and water resistance, it is pointed out that it is hard and brittle. On the other hand, when a general phenol novolak is added to the reaction system, the curing temperature can be lowered, but the flame retardancy, water resistance and toughness are lowered.
[0004]
[Means for Solving the Problems]
In view of these circumstances, the present inventors have conducted intensive studies in search of a resin composition having high flame retardancy, high water resistance, and excellent workability. As a result, a compound having a benzoxazine ring and a phenol resin having a specific structure The inventors have found that a resin composition with an epoxy resin and / or an epoxy resin satisfies these characteristics, and have completed the present invention.
[0005]
That is, the present invention provides (1) (a) a compound having a benzoxazine ring in the structure (b);
[0006]
Embedded image

[0007]
(Where m represents the number of repetitions)
A resin composition characterized by containing a phenol resin having a weight average molecular weight of 5,000 to 20,000,
(2) The resin composition according to claim 1, further comprising (c) an epoxy resin.
(3)
The component (c) has the following formula (2)
[0008]
Embedded image

(In the formula, n represents the number of repetitions.)
[0009]
The resin composition according to (2) above,
(4) Component (a) is represented by the following formula (3)
[0010]
Embedded image

[0011]
Or the following formula (4)
[0012]
Embedded image

[0013]
(Wherein X is a single bond or the following formula (5)
[0014]
Embedded image

[0015]
Represents one of the structures shown. )
The resin composition according to any one of the above (1) to (3), which is a compound represented by the formula:
(5) The resin composition according to any one of the above (1) to (4), which contains a curing accelerator.
(6) a cured product obtained by curing the resin composition according to any one of (1) to (5);
Is provided.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The component (a) used in the present invention is not particularly limited as long as it is a compound having a benzoxazine ring (referred to as a benzoxazine ring-containing compound). For example, JP-A-2001-288339 describes it as a compound having a dihydrobenzoxazine ring. Compounds and the like can be used. The benzoxazine ring-containing compound undergoes ring-opening polymerization upon heating and acts as a crosslinking agent for the phenolic resin, and also becomes a compound having a phenolic hydroxyl group upon ring-opening polymerization, and thus acts as a curing agent for the epoxy resin.
In the present invention, among the benzoxazine ring-containing compounds, the compound represented by the above formula (3) or (4) is preferable because of its low viscosity and excellent workability.
[0017]
In the present invention, the mixing ratio of the component (a) to the component (b) is usually from 5:95 to 95 to 5, preferably from 10:90 to 90:10 by weight.
[0018]
The component (b) used in the present invention is represented by the formula (1), and is not particularly limited as long as the polymerization average molecular weight is about 5,000 to 20,000. The structure itself of the phenolic resin of the formula (1) is known, and is described in, for example, JP-A-8-143648, JP-A-2001-40053, JP-A-11-140166, and the like. The phenolic resin having the structure of the formula (1) is capable of reacting a phenol with a biphenyl derivative such as bis (methoxymethyl) biphenyl, bis (chloromethyl) biphenyl, and bis (hydroxymethyl) biphenyl in the presence of an acid catalyst. However, the weight average molecular weight of the phenol resin obtained by such a general production method is about 500 to 1500.
The component (b) used in the present invention can be obtained by chain-extending such a low-molecular-weight phenol resin with a biphenyl derivative as described above.
[0019]
Specifically, the biphenyl derivative is added in an amount of usually 0.01 to 0.45 mol, preferably 0.05 to 0.4 mol, per 1 equivalent of the phenolic hydroxyl group of the low molecular weight phenol resin, and the condensation reaction is carried out. Do.
[0020]
In the condensation reaction, a catalyst is not particularly necessary when the biphenyl derivative is bis (chloromethyl) biphenyl, but an acid catalyst is used when bis (methoxymethyl) biphenyl or bis (hydroxymethyl) biphenyl is used. Examples of the acid catalyst that can be used include hydrochloric acid, sulfuric acid, and para-toluenesulfonic acid, and para-toluenesulfonic acid is particularly preferable. The amount of the acid catalyst to be used is generally 0.001 to 0.1 part by weight, preferably 0.005 to 0.05 part by weight, per 1 mol of the biphenyl derivative.
[0021]
In the condensation reaction, a solvent may be used because the viscosity increases as the molecular weight of the product increases. As a solvent that can be used, a solvent having a boiling point of 100 to 200 ° C. and being inert to an acid is preferable. Specific examples include propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and the like. The solvent is added to the reaction system in an amount of usually 2 to 200% by weight, preferably 3 to 150% by weight based on the weight of the product.
The reaction is performed until the biphenyl derivative has completely disappeared. The reaction temperature is usually 100 to 180 ° C, and the reaction time is usually 1 to 20 hours.
[0022]
When bis (chloromethyl) biphenyl is used as a raw material, nitrogen is blown from one side of the reactor, and hydrochloric acid gas generated as a by-product is taken out from the other side by a tube or the like. The extracted hydrochloric acid is preferably bubbled and trapped in an alkaline aqueous solution such as an aqueous sodium hydroxide solution.
[0023]
After the completion of the reaction, the above-mentioned solvent, preferably an alkylphenol, is further added to the system as necessary to dissolve the resin component. Examples of the alkylphenol that can be used here include phenol, orthocresol, metacresol, paracresol, xylenol, etc., but cresol, particularly orthocresol, is preferred from the viewpoint of solubility in water and melting point. The solvent is used in such an amount that the total amount of the solvent is usually about 30 to 300% by weight, preferably about 50 to 250% by weight based on the weight of the product.
[0024]
After the addition of the solvent, the inside of the system is kept at 50 to 100 ° C., and hot water is added under stirring. The amount of warm water is usually 10 to 300% by weight, preferably 20 to 200% by weight, based on the weight of the product. After sufficient stirring, the mixture is allowed to stand, and separated into an aqueous layer (upper layer) and an oil layer (lower layer). This washing step is repeated until the aqueous layer shows neutrality. Usually, the required number of times of washing is 2 to 10 times. After washing with water, the solvent is distilled off under reduced pressure under heating to obtain the desired high molecular weight phenol resin. In the formula (1), m represents the number of repetitions, and is usually 5 to 25, preferably 6 to 20. The softening point of the phenol resin of the component (b) is usually from 60 to 140 ° C. The hydroxyl group equivalent is usually 200 to 260 g / eq.
[0025]
Although the resin composition of the present invention exhibits thermosetting properties only by the component (a) and the component (b), an epoxy resin can also be used as the component (c). Examples of epoxy resins that can be used include novolak type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins, dicyclopentadiene phenol co-condensation type epoxy resins, and commercial products are available. . Among them, the epoxy resin represented by the above formula (2) is preferable from the viewpoint of improving the flame retardancy of the cured product.
The component (c) preferably has a softening point of usually 50 to 80 ° C, and preferably has an epoxy equivalent of usually 260 to 290 g / eq.
[0026]
In the resin composition of the present invention, the compounding ratio of the component (c) is usually from 5:95 to 95 to 5, preferably from 10:90 to 90:10 by weight ratio of the component (a) to the component (c). It is.
[0027]
In the resin composition of the present invention containing an epoxy resin, a curing accelerator may be used. Specific examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, and 1,8-diaza-. Tertiary amines such as bicyclo (5,4,0) undecene-7; phosphines such as triphenylphosphine; and metal compounds such as tin octylate. The curing accelerator is used as needed in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the resin.
[0028]
The resin composition of the present invention may optionally contain an inorganic filler. Specific examples of the inorganic filler that can be used include silica, alumina, and talc. The inorganic filler is used in an amount occupying 0 to 90% by weight in the resin composition of the present invention. Furthermore, various compounding agents such as a silane coupling agent, a releasing agent such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, and a pigment can be added to the resin composition of the present invention.
[0029]
The resin composition of the present invention is obtained by uniformly mixing the components. The resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, a compound having a benzoxazine ring, a phenol resin and / or an epoxy resin of the formula (1) and, if necessary, a curing accelerator, an inorganic filler and a compounding agent, if necessary, may be used in an extruder, kneader, roll. The resin composition is sufficiently mixed until it becomes uniform using, for example, the resin composition is melted and then molded using a casting or transfer molding machine and the like, and further heated at 80 to 200 ° C. for 2 to 10 hours. A cured product can be obtained by heating.
[0030]
Further, the resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone to prepare a varnish, which is coated on a copper foil, a polyimide film, a PET (polyethylene terephthalate) film or the like, and heated By evaporating and curing the solvent in the above, a film-like cured product can also be obtained. In addition, the varnish obtained is impregnated into a base material such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc., heated and semi-dried, and a prepreg obtained is hot-pressed to obtain a cured product. You can also. In this case, the solvent is used in an amount which usually accounts for 10 to 70% by weight, preferably 15 to 70% by weight in the mixture of the resin composition and the solvent.
[0031]
【Example】
Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the following, parts are by weight unless otherwise specified.
[0032]
Synthesis Example 1
After adding 315 parts of phenol to a flask equipped with a thermometer, a condenser, and a stirrer and raising the temperature to 80 ° C., 251 parts of 4,4′-bis (chloromethyl) biphenyl was divided under stirring for 4 hours. After charging and further stirring for 1.5 hours, 3.7 parts of tripolyphosphoric acid was added, and the mixture was neutralized by stirring for 30 minutes. Thereafter, unreacted phenol was removed under reduced pressure under heating to obtain 326 parts of a phenol resin. The obtained resin had a softening point of 71 ° C. and a hydroxyl equivalent of 214 g / eq.
[0033]
The resin 214 obtained was purged with a nitrogen gas in a flask equipped with a thermometer, a fractionating tube, a cooling tube, a stirrer, and a silicon tube at the end of the cooling tube so that hydrochloric acid gas generated in the container could be driven out of the system. To this part, 56,3 parts of 4,4′-bis (chloromethyl) biphenyl and 50.8 parts of propylene glycol monomethyl ether were added, and the mixture was heated to 130 ° C. with stirring and dissolved while blowing in nitrogen. The reaction was followed by gel permeation chromatography analysis, and after confirming that 4,4′-bis (chloromethyl) biphenyl had completely disappeared 4 hours after the start of the reaction, stirring was continued for another 2 hours to terminate the reaction. .
[0034]
The temperature in the system was cooled to 90 ° C., 254 parts of orthocresol and 500 parts of warm water were added, and the mixture was stirred at 80 ° C. for 10 minutes. After standing, the aqueous layer was removed from the upper layer by siphon drainage. Next, 500 parts of warm water was added, and the same operation of stirring, standing, and separating was further repeated twice. In the third washing step, the aqueous layer became neutral, and thus orthocresol was distilled off from the oil layer under reduced pressure by heating using an evaporator to obtain 241 parts of a phenol resin represented by the formula (1) ( M = 8.9 (average value) in equation (1)). The obtained resin (hereinafter, referred to as phenolic resin (B)) had a weight average molecular weight by GPC of 12,400, a softening point of 135.2 ° C., and a hydroxyl equivalent of 254 g / eq.
[0035]
Examples 1 and 2 Comparative Examples 1 and 2
The following equation (6)
[0036]
Embedded image

[0037]
And a phenol resin (B) obtained in Synthesis Example 1 and a phenol novolak (manufactured by Meiwa Kasei Co., Ltd., H-1; softening point: 83 ° C., hydroxyl equivalent: 106 g / eq, weight average molecular weight 960), epoxy resin (C) represented by the above formula (2) (NC-3000 manufactured by Nippon Kayaku Co., Ltd .; softening point 58 ° C, epoxy equivalent 275 g / eq) and methyl ethyl ketone (solvent) MEK) was blended with the composition shown in Table 1 to prepare a varnish. Next, each varnish was impregnated in a glass cloth and dried at 130 ° C. for 7 minutes to obtain a prepreg having a resin content of about 45%. Eight of these prepregs were laminated with copper foil of 5 μm thickness on both sides and press-formed at 170 ° C. under a pressure of 40 kg / m ² for 1 hour to prepare a 1.6 mm-thick copper-clad glass laminate. Table 1 shows the results of testing the flame retardancy, water absorption, and glass transition point of these laminates based on the following methods.
[0038]
Measured according to flame retardancy UL-94 Hygroscopicity 40 ° C., 90% HR Moisture absorption after 100 hours Glass transition point thermomechanical analyzer (TMA): TM-7000 manufactured by Vacuum Riko Co., Ltd.
Heating rate: 2 ° C / min.
[0039]

[0040]
【The invention's effect】
The resin composition of the present invention gives a cured product excellent in flame retardancy, water resistance, and heat resistance as compared with conventionally generally used thermosetting resin compositions.
Therefore, the resin composition of the present invention is extremely useful for a wide range of applications such as electric / electronic materials, molding materials, casting materials, laminate materials, paints, adhesives, resists, and optical materials.

Claims (6)

(A) a compound having a benzoxazine ring in the structure (b) the following formula (1)

(Where m represents the number of repetitions)
And a phenol resin having a weight average molecular weight of 5,000 to 20,000. The resin composition according to claim 1, further comprising (c) an epoxy resin. The component (c) has the following formula (2)

(In the formula, n represents the number of repetitions.)
The resin composition according to claim 2, which is Component (a) is represented by the following formula (3)

Or the following formula (4)

(Wherein X is a single bond or the following formula (5)

Represents any of the structures represented by )
The resin composition according to any one of claims 1 to 3, which is a compound represented by the formula: The resin composition according to claim 1, further comprising a curing accelerator. A cured product obtained by curing the resin composition according to claim 1.