【発明の詳細な説明】[Detailed description of the invention]
本発明は、寸法安定性の良好なエポキシ樹脂ガ
ラス不織布積層板に関する。
エポキシ樹脂積層板は、周知の如く、エポキシ
樹脂を基材に含浸し乾燥して得られるプリプレグ
を積層し、加熱加圧して得られる。ガラス織布基
材を用いた積層板は、寸法安定性はすぐれている
が、加工性が悪く、高価である。ガラス不織布基
材を用いた場合には、加工性がよく、安価に得ら
れるが、寸法安定性が悪い。
本発明は、上記の点に鑑み、基材にガラス不織
布を用いた場合に加工性がよく安価でしかも寸法
安定性の良好なエポキシ樹脂積層板を得ることを
目的とするものである。
本発明は、ガラス不織布基材を用いて、ガラス
織布基材を使用する積層板と同等の寸法安定性を
有し、しかも安価で加工性のよい積層板を得るた
めに、エポキシ樹脂100重量部に対し無機充填剤
を40〜80重量部加えたエポキシ樹脂を基材に含浸
し乾燥して得たプリプレグを用いるものである。
これに関し鋭意検討した結果無機充填剤が40重量
部未満では得られた積層板に充分な寸法安定性を
保持させることができない。また、80重量部を越
えるとワニスの粘度が高くなり、基材への含浸塗
工時の作業性が悪くなるほか、得られた積層板に
充分な機械的強度を保持させることができない。
本発明は、無機充填剤の添加量が40〜80重量部に
おいて良好な寸法安定性が得られる。
本発明に使用できる無機充填剤とは、ケイ酸塩
類、炭酸カルシウム、アルミナなどの粒状、繊維
状のものすべてであり、得られる積層板の電気的
特性を劣化させないためには、アルカリイオンな
どが遊離しないものが好ましい。
また、本発明に使用できるガラス不織布として
は、ガラス繊維のバインダーとしてポバール樹
脂、エポキシ樹脂などの水系樹脂を使用したもの
と、セルロース繊維をガラス繊維に混抄したもの
のいずれも適用できる。
次に、本発明の実施例について述べる。
実施例 １
エポキシ樹脂100重量部、硬化剤ジアミノジフ
エニルメタン10重量部、充填材ガラスビーズ60重
量部よりなるエポキシ樹脂ワニスをガラス不織布
に樹脂量70％になる様含浸し乾燥してプリプレグ
を得た。該プリプレグを積層しプレスにて圧力60
Kg／cm2、温度160℃で30分間成形し、厚さ1.6mmの
積層板を得た。
実施例 ２、３
実施例１と同様に、但しガラスビーズの添加量
を40重量部（実施例２）、また80重量部（実施例
３）としたエポキシ樹脂ワニスを用い、厚さ1.6
mmの積層板をそれぞれ得た。
比較例 １
実施例１と同様に、但しガラスビーズの添加量
を４重量部としたエポキシ樹脂ワニスを用い、厚
さ1.6mmの積層板を得た。
比較例 ２
実施例１と同様に、但しガラスビーズの添加量
を90重量部としたエポキシ樹脂ワニスを用い、厚
さ1.6mmの積層板を得た。
比較例 ３
実施例１と同様に、但しガラスビーズの添加量
を30重量部としたエポキシ樹脂ワニスを用い、厚
さ1.6mmの積層板を得た。
従来例 １
実施例１と同様の方法で、但しガラスビーズを
加えないエポキシ樹脂ワニスを用い、厚さ1.6mm
の積層板を得た。
従来例 ２
従来例１と同様の充填剤を含有しないエポキシ
樹脂ワニスをガラス織布に樹脂量40％になる様含
浸し乾燥してプリプレグを得た。該プリプレグを
積層し、プレスにて圧力60Kg／cm2、温度160℃で
30分間成形し、厚さ1.6mmの積層板を得た。
上記各積層板の特性を第１表に示す。
The present invention relates to an epoxy resin glass nonwoven fabric laminate with good dimensional stability. As is well known, an epoxy resin laminate is obtained by laminating prepregs obtained by impregnating a base material with an epoxy resin and drying them, followed by heating and pressing. A laminate using a glass woven fabric base material has excellent dimensional stability, but has poor workability and is expensive. When a glass nonwoven fabric base material is used, it has good processability and can be obtained at low cost, but it has poor dimensional stability. In view of the above points, it is an object of the present invention to provide an epoxy resin laminate that is easy to process, inexpensive, and has good dimensional stability when a glass nonwoven fabric is used as the base material. In order to obtain a laminate using a glass nonwoven fabric base material, which has the same dimensional stability as a laminate using a glass woven fabric base material, is inexpensive, and has good processability, the epoxy resin 100% weight A prepreg obtained by impregnating a base material with an epoxy resin to which 40 to 80 parts by weight of an inorganic filler has been added and drying is used.
As a result of extensive studies in this regard, it has been found that if the amount of inorganic filler is less than 40 parts by weight, the resulting laminate cannot maintain sufficient dimensional stability. Moreover, if it exceeds 80 parts by weight, the viscosity of the varnish becomes high, which impairs workability during impregnation coating on a substrate, and also makes it impossible for the obtained laminate to maintain sufficient mechanical strength.
In the present invention, good dimensional stability can be obtained when the amount of inorganic filler added is 40 to 80 parts by weight. The inorganic fillers that can be used in the present invention include all granular and fibrous fillers such as silicates, calcium carbonate, and alumina.Alkali ions and the like are required to prevent deterioration of the electrical properties of the resulting laminate. Preferably, those that do not liberate. Further, as the glass nonwoven fabric that can be used in the present invention, either one using a water-based resin such as poval resin or epoxy resin as a binder for glass fibers, or one in which cellulose fibers are mixed with glass fibers can be used. Next, examples of the present invention will be described. Example 1 A glass nonwoven fabric was impregnated with an epoxy resin varnish consisting of 100 parts by weight of an epoxy resin, 10 parts by weight of a curing agent diaminodiphenylmethane, and 60 parts by weight of glass beads as a filler to a resin content of 70% and dried to obtain a prepreg. Ta. Laminate the prepregs and press at a pressure of 60
Kg/cm 2 and a temperature of 160° C. for 30 minutes to obtain a laminate with a thickness of 1.6 mm. Examples 2 and 3 Epoxy resin varnishes were used in the same manner as in Example 1, except that the amount of glass beads added was 40 parts by weight (Example 2) and 80 parts by weight (Example 3), and the thickness was 1.6
mm laminates were obtained respectively. Comparative Example 1 A laminate with a thickness of 1.6 mm was obtained in the same manner as in Example 1, except that an epoxy resin varnish containing 4 parts by weight of glass beads was used. Comparative Example 2 A laminate with a thickness of 1.6 mm was obtained in the same manner as in Example 1, except that an epoxy resin varnish containing 90 parts by weight of glass beads was used. Comparative Example 3 A laminate with a thickness of 1.6 mm was obtained in the same manner as in Example 1, except that an epoxy resin varnish containing 30 parts by weight of glass beads was used. Conventional Example 1 Same method as Example 1, but using epoxy resin varnish without adding glass beads, 1.6 mm thick.
A laminate was obtained. Conventional Example 2 A glass woven fabric was impregnated with the same filler-free epoxy resin varnish as in Conventional Example 1 to a resin content of 40% and dried to obtain a prepreg. The prepregs were laminated and pressed at a pressure of 60 kg/cm 2 and a temperature of 160°C.
Molding was performed for 30 minutes to obtain a laminate with a thickness of 1.6 mm. Table 1 shows the characteristics of each of the above laminates.
【表】
試験方法
(1) 寸法安定性
10×250mmの試験片の長さl1を測定し、次い
でこの試験片を180℃のオーブン中に２時間置
き取り出して20℃、65％RHの雰囲気中に30分
間放置後の長さl2を測定する。
寸法安定性（％）＝l1−l2／l1×100
(2) 曲げ強度はJIS−Ｃに準拠。
(3) 打抜加工性はASTM法による。
第１表から明らかなように、本発明によれば、
ガラス不織布基材を使用しているにも拘らずガラ
ス織布基材を使用したのと同等の寸法安定性を有
するエポキシ樹脂積層板を製造することができ
る。また、打抜加工性も良好であり、十分な曲げ
強度も保持している点その工業的価値は極めて大
なるものである。[Table] Test method (1) Dimensional stability Measure the length l 1 of a 10 x 250 mm test piece, then place the test piece in an oven at 180°C for 2 hours, take it out, and place it in an atmosphere of 20°C and 65% RH. Measure the length l 2 after standing for 30 minutes inside. Dimensional stability (%) = l 1 - l 2 / l 1 ×100 (2) Bending strength conforms to JIS-C. (3) Punching workability is based on ASTM method. As is clear from Table 1, according to the present invention,
Despite using a glass non-woven fabric base material, it is possible to produce an epoxy resin laminate having the same dimensional stability as that using a glass woven fabric base material. Furthermore, it has good punching workability and maintains sufficient bending strength, making it extremely valuable industrially.