JP2012201732A - Epoxy resin, curable resin composition, cured product of the composition, and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin for allowing a cured product thereof to have slightly-changed heat resistance, low thermal expandability, and excellent solvent solubility after subjected to a thermal history.SOLUTION: The epoxy resin is obtained by etherizing a polycondensate of an α-naphthol compound, a β-naphthol compound and formaldehyde by using polyglycidyl ether and contains 15-35% of a trimer shown by structural formula (1) (wherein Rand Rare each a hydrogen atom, a 1C-4C alkyl group or a 1C-4C alkoxy group independently; Gr is a glycidyl group).

Description

  The present invention is a curable resin composition that has little change in heat resistance after the heat history of the cured product obtained, is excellent in low thermal expansion, and can be suitably used for printed wiring boards, semiconductor encapsulants, paints, casting applications, etc. Product, its cured product and epoxy resin.

Epoxy resins are used in adhesives, molding materials, paints, photoresist materials, color developing materials, etc., and are also used in semiconductor encapsulants and prints because they are excellent in the excellent heat resistance and moisture resistance of the resulting cured products. Widely used in electrical and electronic fields such as insulating materials for wiring boards.

  Among these various applications, in the field of printed wiring boards, with the trend toward miniaturization and high performance of electronic equipment, there is a tendency for high density due to narrowing of the wiring pitch of semiconductor devices. As a mounting method, a flip chip connection method in which a semiconductor device and a substrate are joined by solder balls is widely used. In this flip-chip connection method, a solder ball is placed between a wiring board and a semiconductor, and the whole is heated and melt bonded to form a so-called reflow semiconductor mounting method. Therefore, the wiring plate itself is exposed to a high heat environment during solder reflow. In some cases, due to thermal contraction of the wiring board, a large stress is generated in the solder balls connecting the wiring board and the semiconductor, resulting in poor connection of the wiring. Therefore, an insulating material used for a printed wiring board is required to have a low thermal expansion coefficient.

  In addition, in recent years, refractory solders that do not use lead have become mainstream due to laws and regulations for environmental problems, and the reflow temperature is high. Along with this, the connection failure due to the warp of the printed wiring board due to the heat resistance change of the insulating material during reflow is becoming serious. That is, a material with little change in physical properties during reflow is desired.

  In order to meet such requirements, for example, a thermosetting resin composition based on a naphthol novolac epoxy resin obtained by reacting naphthol, formaldehyde, and epichlorohydrin solves technical problems such as low thermal expansion. It has been proposed (see Patent Document 1 below).

  However, the naphthol novolac type epoxy resin is required in recent years although the effect of improving the coefficient of thermal expansion of the resulting cured product is recognized due to the rigidity of the skeleton compared to the general phenol novolac type epoxy resin. The heat resistance of the cured product is greatly changed by the thermal history, and the change in heat resistance after reflow is large in printed circuit board applications, resulting in poor connection of the printed circuit board. It was easy to occur.

  As another naphthol novolak type epoxy resin, for example, an epoxy resin obtained by polycondensation of α-naphthol, β-naphthol and aldehyde is known (see Patent Document 2 below). However, since such an epoxy resin has many epoxy resins composed of β-naphthol dimer, it has high crystallinity, poor solvent solubility, and cannot be cured sufficiently during the curing reaction. However, the heat resistance greatly changed depending on the heat history.

Japanese Examined Patent Publication No. 62-20206 JP-A-5-287052

  Therefore, the problem to be solved by the present invention is a curable resin composition that exhibits little change in heat resistance after the heat history in the cured product, exhibits low thermal expansion, and realizes better solvent solubility, An object of the present invention is to provide a cured product, a printed wiring board having a low heat expansion after heat history and excellent low thermal expansion, and an epoxy resin that provides these performances.

  As a result of intensive studies to solve the above problems, the present inventors have found that an epoxy resin that is a polyglycidyl ether of a naphthol novolak resin and includes a trimer and a dimer having a specific structure in a predetermined ratio. The cured product exhibits excellent low thermal expansibility, increases the reactivity of the epoxy resin itself, and reduces the change in heat resistance after the heat history, thereby completing the present invention.

That is, the present invention is a polyglycidyl etherified epoxy resin of a polycondensate of an α-naphthol compound, a β-naphthol compound, and formaldehyde,
The following structural formula (1)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される３量体（ｘ１）と、
下記構造式（２）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
A trimer (x1) represented by:
The following structural formula (2)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される２量体（ｘ２）とを含有しており、かつ、前記３量体（ｘ１）の含有率がＧＰＣ測定における面積比率で１５〜３５％となる割合であり、前記２量体（ｘ２）の含有率がＧＰＣ測定における面積比率で１〜２５％となる割合であることを特徴とするエポキシ樹脂に関する。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
And the content of the trimer (x1) is 15 to 35% as an area ratio in GPC measurement, and the dimer It is related with the epoxy resin characterized by being the ratio whose content rate of (x2) is 1 to 25% by the area ratio in GPC measurement.

  The present invention further relates to a curable resin composition comprising the above-described epoxy resin and a curing agent as essential components.

  The present invention further relates to a cured product obtained by curing reaction of the curable resin composition.

  The present invention further relates to a printed wiring obtained by impregnating a reinforcing base material with a resin composition obtained by further blending an organic solvent with the curable resin composition, and then laminating the copper foil and heat-pressing it. Regarding the substrate.

  According to the present invention, there is little change in heat resistance after thermal history in the cured product, low thermal expansion is exhibited, and further curable resin composition realizing good solvent solubility, the cured product, thermal history. It is possible to provide a printed wiring board that is less likely to change heat resistance later and is excellent in low thermal expansion, and an epoxy resin that provides these performances.

1 is a GPC chart of the epoxy resin (A-1) obtained in Example 1. FIG. FIG. 2 is a C ¹³ NMR chart of the epoxy resin (A-1) obtained in Example 1. FIG. 3 is an MS spectrum of the epoxy resin (A-1) obtained in Example 1. FIG. 4 is a GPC chart of the epoxy resin (A-2) obtained in Example 2. FIG. 5 is a GPC chart of the epoxy resin (A-3) obtained in Example 3. FIG. 6 is a GPC chart of the epoxy resin (A-4) obtained in Example 4. FIG. 7 is a C ¹³ NMR chart of the epoxy resin (A-4) obtained in Example 4. FIG. 8 is an MS spectrum of the epoxy resin (A-4) obtained in Example 4. FIG. 9 is a GPC chart of the epoxy resin (A-5) obtained in Comparative Synthesis Example 1. FIG. 10 is a GPC chart of the epoxy resin (A-6) obtained in Comparative Synthesis Example 2.

Hereinafter, the present invention will be described in detail.
The epoxy resin of the present invention is an epoxy resin obtained by polyglycidyl etherification of a polycondensate of an α-naphthol compound, a β-naphthol compound, and formaldehyde, and in the epoxy resin,
The following structural formula (1)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される３量体（ｘ１）と、
下記構造式（２）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
A trimer (x1) represented by:
The following structural formula (2)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される２量体（ｘ２）とを含有しており、かつ、前記３量体（ｘ１）の含有率がＧＰＣ測定における面積比率で１５〜３５質量％となる割合であり、前記２量体（ｘ２）の含有率がＧＰＣ測定における面積比率で１〜２５質量％となる割合であることを特徴としている。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
And the content of the trimer (x1) is 15 to 35% by mass in terms of area ratio in GPC measurement, The content rate of a body (x2) is a ratio which becomes 1-25 mass% in the area ratio in GPC measurement, It is characterized by the above-mentioned.

That is, the epoxy resin of the present invention is a polyglycidyl ether of a polycondensate using α-naphthol compound, β-naphthol compound, and formaldehyde as raw materials, and includes a mixture of various resin structures, Among them, the trimer (x1) and the dimer (x2) are included in a predetermined amount. In the present invention, since the trimer (x1) is contained in the epoxy resin, the orientation at the molecular level is high, and the cured product exhibits excellent low thermal expansion and the trimer (x1). ) Because of its high reactivity, it becomes a material with little change in heat resistance after heat history in a cured product and little change in physical properties after reflow in printed wiring board applications.
Here, as described above, the content of the trimer (x1) is in the range of 15 to 35% in terms of area ratio in GPC measurement, but when it exceeds 35% by mass, the solvent solubility of the epoxy resin is lowered. To do. On the other hand, when it is less than 15%, the linear expansion coefficient of the cured product becomes high.

  Specifically, such trimer (x1) has the following structural formulas (1-1) to (1-6).

で表される化合物が挙げられる。これらのなかでも特に前記構造式１−１で表されるもの、即ち、前記構造式（１）におけるＲ^１及びＲ^２が、全て水素原子であるものが、硬化物における熱履歴後の耐熱性変化が小さくなる点から好ましい。

The compound represented by these is mentioned. Among these, particularly those represented by the structural formula 1-1, that is, those in which R ¹ and R ² in the structural formula (1) are all hydrogen atoms, the heat resistance after the heat history in the cured product. This is preferable from the viewpoint of small change.

  In addition, the trimer (x1) is, in particular,

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される結合位置を有するエポキシ樹脂であることが、硬化物における低線膨張性及び熱履歴後の耐熱性変化が小さくなる点から好ましく、とりわけ該構造式（１）におけるＲ^１及びＲ^２が、全て水素原子であるものが、硬化物における熱履歴後の耐熱性変化が小さくなる点から好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
It is preferable that it is an epoxy resin having a bonding position represented by the formula (1) from the viewpoint of low linear expansion in the cured product and a reduction in heat resistance after thermal history, and in particular, R ¹ and R ² in the structural formula (1). However, it is preferable that all are hydrogen atoms from the viewpoint that the heat resistance change after the heat history in the cured product is reduced.

  Moreover, in this invention, since the said dimer (x2) is included 1% or more, the low linear expansion property of hardened | cured material is excellent. Since the blending amount of the dimer (x2) is 25% or less, excellent solvent solubility can be expressed, and it can be used as a varnish for a printed wiring board.

  In addition to the trimer (x1) and the dimer (x2), the epoxy resin of the present invention further includes the following structural formula (3).

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表し、ｎは繰り返し単位であって２〜１０の整数である。）
で表されるカリックスアレーン化合物（ｘ３）を、エポキシ樹脂中ＧＰＣ測定における面積比率で１〜４０％となる割合で含有することが、硬化物における低線膨張性が一層良好なものとなる点から好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, Gr represents a glycidyl group, and n is a repeating group. It is a unit and is an integer of 2 to 10.)
From the point that the low linear expansion property in the cured product is further improved by containing the calixarene compound (x3) represented by the formula (1) at a ratio of 1 to 40% in the area ratio in the GPC measurement in the epoxy resin. preferable.

Here, R ¹ and R ² in the structural formula (3) are synonymous with those in the structural formula (1). Although the repeating unit n is an integer of 2 to 10, n is preferably 4 from the viewpoint that the low linear expansion in the cured epoxy resin of the present invention is further improved.

The content of the trimer (x1), the dimer (x2), and the calixarene compound (x3) in the epoxy resin in the present invention is calculated by GPC measurement under the following conditions. The ratio of the peak area of each structure to the total peak area of the epoxy resin.
<GPC measurement conditions>
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (differential refractometer)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.
(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).

  The epoxy resin of the present invention may contain a high molecular weight component (x4) in addition to the trimer (x1), the dimer (x2), and the calixarene compound (x3) described above.

  Such a high molecular weight component (x4) is a high molecular weight component excluding the above (x1) to (x3) in the epoxy resin of the present invention, and specifically, the following structural formula (I)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表す。）
で表される構造ユニット（Ｉ）と、
下記、構造式（ＩＩ）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
A structural unit (I) represented by:
Structural formula (II) below

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を示し、Ｇｒはグリシジル基を表し、ｍは繰り返し単位であり、０以上の整数である。）
で表される構造ユニット（ＩＩ）とが、メチレン結合により結節され、高分子量化した基本構造を有するエポキシ樹脂である。

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, Gr represents a glycidyl group, and m is a repeating group) Unit, an integer greater than or equal to 0.)
And an epoxy resin having a basic structure that is knotted by a methylene bond and has a high molecular weight.

  The dimer (x2), the trimer (x1), and the calixarene compound (x3) are detected in this order from the longest retention time by GPC measurement, and the high molecular weight component (x4) is the calixarene compound (x3). Therefore, it is a component detected in a region having a short holding time. The proportion of the high molecular weight component (x4) in the epoxy resin is preferably an area ratio in the GPC measurement in the range of 40 to 75% by mass from the viewpoint of excellent solvent solubility of the epoxy resin.

  In addition to the α-naphthol compound, β-naphthol compound, and formaldehyde as a raw material component of the polycondensate, when the other novolak resin is used in combination, the high molecular weight component (x4) is the structural unit. (I), the structural unit (II), and the other novolak resin are knotted to each other through a methylene bond to have a high molecular weight. In addition, when using the said other novolak resin together as a raw material component of the said polycondensate at the time of manufacture, the usage-amount is 5 per 100 mass parts of total mass of (alpha) -naphthol compound and (beta) -naphthol compound used as a raw material. It is preferable that it is 30 mass parts from the point which is excellent in the reactivity of the epoxy resin finally obtained.

  The epoxy resin of the present invention described in detail above preferably has a softening point in the range of 95 to 140 ° C. from the viewpoint of excellent solvent solubility of the epoxy resin itself. Accordingly, the molecular weight of the high molecular weight component (x4) is also high. What is necessary is just to adjust suitably so that the softening point of an epoxy resin may enter into the said range. The softening point is particularly preferably in the range of 100 to 135 ° C. from the viewpoint that the low thermal expansion property and the solvent solubility can be highly combined.

  Moreover, it is preferable that the epoxy equivalent of the epoxy resin of the present invention is in the range of 210 to 300 g / eq from the viewpoint of good low thermal expansion of the cured product, and particularly in the range of 220 to 260 g / eq. Is preferred.

The epoxy resin of the present invention described in detail above can be produced by, for example, the following method 1 or method 2.
Method 1: A β-naphthol compound and formaldehyde are reacted in the presence of an organic solvent and an alkali catalyst, and then an α-naphthol compound and formaldehyde are added and reacted to obtain a naphthol resin (step 1), which is then obtained. A method of reacting an epihalohydrin with a naphthol resin (step 2) to obtain a target epoxy resin.
Method 2: α-naphthol compound, β-naphthol compound, and formaldehyde are reacted in the presence of an organic solvent and an alkali catalyst to obtain a naphthol resin (step 1), and then the resulting naphthol resin fat is reacted with epihalohydrin. (Step 2) to obtain the target epoxy resin.

  In the present invention, the trimer (x1) and the 2 are obtained by using an alkali catalyst as a reaction catalyst in Step 1 of the method 1 or 2 and using an organic solvent in a small amount with respect to the raw material components. The abundance ratio of the monomer (x2) and the calixarene compound (x3) in the epoxy resin can be adjusted to a predetermined range, and the abundance ratio of the high molecular weight component is also in an appropriate range.

  Examples of the alkali catalyst used herein include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, inorganic alkalis such as metal sodium, metal lithium, sodium hydride, sodium carbonate, and potassium carbonate. The amount used is 0.01 to 2.0 times the amount of the raw material components α-naphthol compound, β-naphthol compound, and, if necessary, the total number of phenolic hydroxyl groups of the other novolak resin on a molar basis. It is preferable that it is the range.

Examples of the organic solvent include methyl cellosolve, isopropyl alcohol, ethyl cellosolve, toluene, xylene, and methyl isobutyl ketone. Of these, isopropyl alcohol is particularly preferred from the viewpoint of relatively high molecular weight of the polycondensate.
In the present invention, the amount of the organic solvent used is that of the raw material components α-naphthol compound and β-naphthol compound, and when the other novolak resin is used in combination, the raw material α-naphthol compound and β-naphthol compound are used. The proportion of the trimer (x1), the dimer (x2), and the calixarene compound (x3) in the epoxy resin is in the range of 5 to 70 parts by mass per 100 parts by mass of the total mass. Is preferable because it is easy to adjust to a predetermined range.

  Specifically, the α-naphthol compound which is a raw material component includes α-naphthol and an alkyl group such as a methyl group, an ethyl group, a propyl group and a t-butyl group, and an alkoxy group such as a methoxy group and an ethoxy group. In addition, the β-naphthol compound includes β-naphthol and alkyl groups such as a methyl group, an ethyl group, a propyl group, and a t-butyl group, and an alkoxy group such as a methoxy group and an ethoxy group. Among these, compounds having a nucleus substituted, etc. Among these, α-naphthol having no substituent and β-naphthol are less heat resistance change after heat history in the cured epoxy resin obtained finally. preferable.

  On the other hand, the formaldehyde used here may be a formalin solution in an aqueous solution state or paraformaldehyde in a solid state.

  The ratio of α-naphthol compound and β-naphthol compound used in Step 1 of Method 1 or Method 2 is such that the molar ratio (α-naphthol compound / β-naphthol compound) is [1 / 0.4] to [1. /1.2] It is preferable that the ratio of each component in the finally obtained epoxy resin is easily adjusted.

  The reaction charge ratio of formaldehyde is a ratio of 0.6 to 2.0 times the amount of formaldehyde on a molar basis with respect to the total number of moles of α-naphthol compound and β-naphthol compound, in particular, low thermal expansion. From the viewpoint of excellent properties, the ratio is preferably 0.6 to 1.5 times the amount.

  In the present invention, as described above, in addition to the α-naphthol compound, β-naphthol compound, and formaldehyde as raw material components, another novolak resin can be used in combination. Here, as other novolak resins to be used, for example, phenol novolak resins and cresol novolak resins can be mentioned, and by using these in combination, the solvent solubility of the epoxy resin finally obtained can be dramatically improved. Can do. These phenol novolak resins and cresol novolak resins are preferably those having a softening point of 60 to 120 ° C. from the viewpoint that the solvent solubility can be improved without reducing the performance such as low linear expansion in the present invention.

  When the other novolak resin is used as a part of the raw material, the reaction charge ratio of each raw material component in Step 1 of Method 1 or Method 2 is a molar ratio (α-naphthol compound and β-naphthol compound / other novolaks). It is easy to adjust the ratio of each component in the epoxy resin finally obtained when the number of aromatic nuclei in the resin is in the range of [1 / 0.06] to [1 / 0.36]. Preferably, the amount of formaldehyde used is 0.6 to 2.2 on a molar basis with respect to the total number of moles of aromatic nuclei, α-naphthol compounds and β-naphthol compounds in other novolak resins. It is preferable that the amount be 0 times the amount, in particular, the range where the amount becomes 0.6 to 1.5 times the amount from the viewpoint of excellent balance between heat resistance and solvent solubility.

  In step 1 of Method 1, a reaction vessel is charged with a predetermined amount of β-naphthol compound, formaldehyde, an organic solvent, and an alkali catalyst and reacted at 40 to 100 ° C. After the reaction is completed, α-naphthol compound is added. The desired polycondensate can be obtained by reaction under a temperature condition of 40 to 100 ° C. In this case, when another novolak resin is used in combination, it is preferably added to the reaction vessel together with the α-naphthol compound.

  After completion of the reaction in Step 1, neutralization or water washing is performed until the pH value of the reaction mixture becomes 4 to 7 after the reaction is completed. The neutralization treatment and the water washing treatment may be performed according to conventional methods. For example, acidic substances such as acetic acid, phosphoric acid, and sodium phosphate can be used as the neutralizing agent. After neutralization or water washing treatment, the organic solvent is distilled off under reduced pressure heating to obtain the desired polycondensate.

  In step 1 of Method 2, when a predetermined amount of β-naphthol compound, α-naphthol compound, formaldehyde, an organic solvent, an alkali catalyst, and other novolak resins are used in combination in the reaction vessel, the novolak resin is charged. The desired polycondensate can be obtained by reacting at 40 to 100 ° C. In this case, when another novolak resin is used in combination, it is preferably added to the reaction vessel together with the α-naphthol compound.

  After completion of the reaction in Step 1, neutralization or water washing is performed until the pH value of the reaction mixture becomes 4 to 7 after the reaction is completed. The neutralization treatment and the water washing treatment may be performed according to conventional methods. For example, acidic substances such as acetic acid, phosphoric acid, and sodium phosphate can be used as the neutralizing agent. After neutralization or water washing treatment, the organic solvent is distilled off under reduced pressure heating to obtain the desired polycondensate.

  Next, Step 2 of Method 1 or Method 2 is a step of producing the desired epoxy resin by reacting the polycondensate obtained in Step 1 with epihalohydrin. Specifically, in the step 2, epihalohydrin is added in a ratio of 2 to 10 times (molar basis) with respect to the number of moles of the phenolic hydroxyl group in the polycondensate, and further the mole of the phenolic hydroxyl group. A method of reacting at a temperature of 20 to 120 ° C. for 0.5 to 10 hours while adding or gradually adding 0.9 to 2.0 times (molar basis) of the basic catalyst to the number is mentioned. The basic catalyst may be solid or an aqueous solution thereof. When an aqueous solution is used, it is continuously added and water and epihalohydrins are continuously distilled from the reaction mixture under reduced pressure or normal pressure. Alternatively, the solution may be separated and further separated to remove water and the epihalohydrin is continuously returned to the reaction mixture.

  In the first batch of epoxy resin production, all of the epihalohydrins used for preparation are new in industrial production, but the subsequent batches are consumed by the reaction with epihalohydrins recovered from the crude reaction product. It is preferable to use in combination with new epihalohydrins corresponding to the amount disappeared. At this time, the epihalohydrin used is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, β-methylepichlorohydrin, and the like. Of these, epichlorohydrin is preferred because it is easily available industrially.

  Specific examples of the basic catalyst include alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. In particular, alkali metal hydroxides are preferable from the viewpoint of excellent catalytic activity of the epoxy resin synthesis reaction, and examples thereof include sodium hydroxide and potassium hydroxide. In use, these basic catalysts may be used in the form of an aqueous solution of about 10 to 55% by mass, or in the form of a solid. Moreover, the reaction rate in the synthesis | combination of an epoxy resin can be raised by using an organic solvent together. Examples of such organic solvents include, but are not limited to, ketones such as acetone and methyl ethyl ketone, alcohol compounds such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol, and tertiary butanol, methyl Examples thereof include cellosolves such as cellosolve and ethyl cellosolve, ether compounds such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and diethoxyethane, and aprotic polar solvents such as acetonitrile, dimethyl sulfoxide and dimethylformamide. These organic solvents may be used alone or in combination of two or more kinds in order to adjust the polarity.

  After the reaction product of the epoxidation reaction is washed with water, unreacted epihalohydrin and the organic solvent to be used in combination are distilled off by distillation under heating and reduced pressure. Further, in order to obtain an epoxy resin with less hydrolyzable halogen, the obtained epoxy resin is again dissolved in an organic solvent such as toluene, methyl isobutyl ketone, methyl ethyl ketone, and alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Further reaction can be carried out by adding an aqueous solution of the product. At this time, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present for the purpose of improving the reaction rate. When the phase transfer catalyst is used, the amount used is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the epoxy resin used. After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and further, the target epoxy resin of the present invention can be obtained by distilling off a solvent such as toluene and methyl isobutyl ketone under heating and reduced pressure.

  Next, the curable resin composition of the present invention comprises the epoxy resin and the curing agent detailed above as essential components.

Examples of the curing agent used here include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, and the like. Specifically, examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivative. Examples of the amide compound include dicyandiamide. And polyamide resins synthesized from dimer of linolenic acid and ethylenediamine. Examples of acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and tetrahydrophthalic anhydride. Acid, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc., and phenolic compounds include phenol novolac resin, cresol novolac resin Aromatic hydrocarbon formaldehyde resin modified phenolic resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin (Zylok resin), polyhydric phenol novolak resin synthesized from formaldehyde and polyhydroxy compound represented by resorcin novolac resin, naphthol Aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin Phenolic compounds), biphenyl-modified naphthol resins (polyvalent naphthol compounds in which phenol nuclei are linked by bismethylene groups), aminotriazine-modified phenols Resin (polyhydric phenol compound in which phenol nucleus is linked with melamine, benzoguanamine, etc.) or alkoxy group-containing aromatic ring modified novolak resin (polyhydric phenol compound in which phenol nucleus and alkoxy group-containing aromatic ring are linked with formaldehyde) A polyhydric phenol compound is mentioned.

  Among these, those containing a large amount of an aromatic skeleton in the molecular structure are preferred from the viewpoint of low thermal expansion, and specifically, phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, phenol aralkyls. Resin, resorcinol novolak resin, naphthol aralkyl resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin, biphenyl-modified naphthol resin, aminotriazine-modified phenol resin, alkoxy group-containing aromatic A ring-modified novolak resin (a polyhydric phenol compound in which a phenol nucleus and an alkoxy group-containing aromatic ring are linked with formaldehyde) is preferable because of its low thermal expansion.

  The blending amount of the epoxy resin and the curing agent in the curable resin composition of the present invention is not particularly limited, but a total of 1 equivalent of epoxy groups of the epoxy resin is obtained from the point that the obtained cured product property is good. In contrast, the amount by which the active group in the curing agent is 0.7 to 1.5 equivalents is preferable.

  Moreover, a hardening accelerator can also be suitably used together with the curable resin composition of this invention as needed. Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. In particular, when used as a semiconductor encapsulating material, it is excellent in curability, heat resistance, electrical characteristics, moisture resistance reliability, etc., so that triphenylphosphine is used for phosphorus compounds and 1,8-diazabicyclo is used for tertiary amines. -[5.4.0] -undecene (DBU) is preferred.

  In the curable resin composition of the present invention, the epoxy resin of the present invention described above may be used alone as an epoxy resin component, but other epoxy resins may be used within a range not impairing the effects of the present invention. . Specifically, the epoxy resin of the present invention described above can be used in combination with another epoxy resin within a range of 30% by mass or more, preferably 40% by mass or more with respect to the total mass of the epoxy resin component.

Here, as other epoxy resins that can be used in combination with the epoxy resin, various epoxy resins can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type Epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type Epoxy resin, naphthol novolac type epoxy resin,
Examples thereof include a naphthol aralkyl type epoxy resin, a naphthol-phenol co-condensed novolac type epoxy resin, a naphthol-cresol co-condensed novolac type epoxy resin, an aromatic hydrocarbon formaldehyde resin-modified phenol resin type epoxy resin, and a biphenyl novolac type epoxy resin. Among these, phenol aralkyl type epoxy resins, biphenyl novolak type epoxy resins, naphthol novolak type epoxy resins containing a naphthalene skeleton, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolacs. Type epoxy resin, crystalline biphenyl type epoxy resin, tetramethyl biphenyl type epoxy resin, xanthene type epoxy resin, alkoxy group-containing aromatic ring-modified novolak type epoxy resin (formaldehyde glycidyl group-containing aromatic ring and alkoxy group-containing aromatic ring Are particularly preferable in that a cured product having excellent heat resistance can be obtained.

  As described above, the curable resin composition of the present invention described in detail above is characterized by exhibiting excellent solvent solubility. Therefore, the curable resin composition preferably contains an organic solvent in addition to the above components. Examples of the organic solvent that can be used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. The amount used can be appropriately selected depending on the application. For example, in printed wiring board applications, it is preferable to use a polar solvent having a boiling point of 160 ° C. or lower, such as methyl ethyl ketone, acetone, dimethylformamide, and the non-volatile content of 40 to 80% by mass. It is preferable to use in the ratio which becomes. On the other hand, in build-up adhesive film applications, as organic solvents, for example, ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, It is preferable to use carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like, and the nonvolatile content is 30 to 60% by mass. It is preferable to use in proportions.

  The thermosetting resin composition is a non-halogen flame retardant that substantially does not contain a halogen atom in order to exert flame retardancy, for example, in the field of printed wiring boards, as long as the reliability is not lowered. May be blended.

  Examples of the non-halogen flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants. The flame retardants may be used alone or in combination, and a plurality of flame retardants of the same system may be used, or different types of flame retardants may be used in combination.

  As the phosphorus flame retardant, either inorganic or organic can be used. Examples of the inorganic compounds include red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphates such as ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amide. .

  The red phosphorus is preferably subjected to a surface treatment for the purpose of preventing hydrolysis and the like. Examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, water A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof; (ii) an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide; and A method of coating with a mixture of a thermosetting resin such as a phenol resin, (iii) thermosetting of a phenol resin or the like on a coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, or titanium hydroxide For example, a method of double coating with a resin may be used.

  Examples of the organic phosphorus compound include, for example, general-purpose organic phosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, and 9,10- Dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,5-dihydrooxyphenyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,7- Examples thereof include cyclic organophosphorus compounds such as dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, and derivatives obtained by reacting them with compounds such as epoxy resins and phenol resins.

  The blending amount thereof is appropriately selected depending on the type of the phosphorus-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. In 100 parts by mass of curable resin composition containing all of halogen-based flame retardant and other fillers and additives, 0.1 to 2.0 parts by mass of red phosphorus is used as a non-halogen flame retardant. It is preferable to mix in the range, and when using an organophosphorus compound, it is preferably mixed in the range of 0.1 to 10.0 parts by mass, particularly in the range of 0.5 to 6.0 parts by mass. It is preferable to do.

  In addition, when using the phosphorous flame retardant, the phosphorous flame retardant may be used in combination with hydrotalcite, magnesium hydroxide, boric compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc. Good.

  Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, phenothiazines, and the like, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

  Examples of the triazine compound include melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylene dimelamine, melamine polyphosphate, triguanamine, and the like, for example, (i) guanylmelamine sulfate, melem sulfate, sulfate (Iii) co-condensates of phenols such as phenol, cresol, xylenol, butylphenol and nonylphenol with melamines such as melamine, benzoguanamine, acetoguanamine and formguanamine and formaldehyde, (iii) (Ii) a mixture of a co-condensate of (ii) and a phenolic resin such as a phenol formaldehyde condensate, (iv) those obtained by further modifying (ii) and (iii) with paulownia oil, isomerized linseed oil, etc. It is.

  Specific examples of the cyanuric acid compound include cyanuric acid and cyanuric acid melamine.

  The compounding amount of the nitrogen-based flame retardant is appropriately selected according to the type of the nitrogen-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.05 to 10 parts by mass in 100 parts by mass of the curable resin composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. It is preferable to mix | blend in the range of 1-5 mass parts.

  Moreover, when using the said nitrogen-type flame retardant, you may use together a metal hydroxide, a molybdenum compound, etc.

  The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin.

  The amount of the silicone-based flame retardant is appropriately selected depending on the type of the silicone-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.05 to 20 parts by mass in 100 parts by mass of the curable resin composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. Moreover, when using the said silicone type flame retardant, you may use a molybdenum compound, an alumina, etc. together.

  Examples of the inorganic flame retardant include metal hydroxide, metal oxide, metal carbonate compound, metal powder, boron compound, and low melting point glass.

  Specific examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, zirconium hydroxide and the like.

  Specific examples of the metal oxide include, for example, zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, and cobalt oxide. Bismuth oxide, chromium oxide, nickel oxide, copper oxide, tungsten oxide and the like.

  Specific examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

  Specific examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

  Specific examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

Specific examples of the low-melting-point glass include, for example, Ceeley (Bokusui Brown), hydrated glass SiO ₂ —MgO—H ₂ O, PbO—B ₂ O ₃ system, ZnO—P ₂ O ₅ —MgO system, P ₂ O ₅ —B ₂ O ₃ —PbO—MgO, P—Sn—O—F, PbO—V ₂ O ₅ —TeO ₂ , Al ₂ O ₃ —H ₂ O, lead borosilicate, etc. The glassy compound can be mentioned.

  The amount of the inorganic flame retardant is appropriately selected depending on the type of the inorganic flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.05 to 20 parts by mass in 100 parts by mass of the curable resin composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. It is preferable to mix | blend in 5-15 mass parts.

  Examples of the organic metal salt flame retardant include ferrocene, acetylacetonate metal complex, organic metal carbonyl compound, organic cobalt salt compound, organic sulfonic acid metal salt, metal atom and aromatic compound or heterocyclic compound or an ionic bond or Examples thereof include a coordinated compound.

  The amount of the organic metal salt flame retardant is appropriately selected depending on the type of the organic metal salt flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. In 100 parts by mass of the curable resin composition in which all of epoxy resin, curing agent, non-halogen flame retardant and other fillers and additives are blended, it is preferably blended in the range of 0.005 to 10 parts by mass. .

  An inorganic filler can be mix | blended with the curable resin composition of this invention as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When particularly increasing the blending amount of the inorganic filler, it is preferable to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape. However, in order to increase the blending amount of the fused silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The filling rate is preferably higher in consideration of flame retardancy, and particularly preferably 20% by mass or more with respect to the total amount of the curable resin composition. Moreover, when using for uses, such as an electrically conductive paste, electroconductive fillers, such as silver powder and copper powder, can be used.

  Various compounding agents, such as a silane coupling agent, a mold release agent, a pigment, an emulsifier, can be added to the curable resin composition of this invention as needed.

  The curable resin composition of the present invention can be obtained by uniformly mixing the above-described components. The curable resin composition of the present invention in which the epoxy resin of the present invention, a curing agent, and further, if necessary, a curing accelerator are blended can be easily made into a cured product by a method similar to a conventionally known method. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

  Applications for which the curable resin composition of the present invention is used include printed wiring board materials, resin casting materials, adhesives, interlayer insulation materials for build-up substrates, and adhesive films for build-ups. Among these various applications, in printed circuit boards, insulating materials for electronic circuit boards, and adhesive films for build-up, passive parts such as capacitors and active parts such as IC chips are embedded in so-called electronic parts. It can be used as an insulating material for a substrate. Among these, it is preferable to use for the printed wiring board material and the adhesive film for buildup from the characteristics, such as a small heat resistance change after heat history, low thermal expansibility, and solvent solubility.

  Here, in order to produce a printed circuit board from the curable resin composition of the present invention, the varnish-like curable resin composition containing the organic solvent is impregnated into a reinforcing base material, and a copper foil is overlaid and thermocompression bonded. A method is mentioned. Examples of the reinforcing substrate that can be used here include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. If this method is described in further detail, first, the varnish-like curable resin composition is heated at a heating temperature corresponding to the solvent type used, preferably 50 to 170 ° C., thereby being a prepreg which is a cured product. Get. The mass ratio of the resin composition and the reinforcing substrate used at this time is not particularly limited, but it is usually preferable that the resin content in the prepreg is 20 to 60% by mass. Next, the prepreg obtained as described above is laminated by a conventional method, and a copper foil is appropriately stacked, and then subjected to thermocompression bonding at a pressure of 1 to 10 MPa at 170 to 250 ° C. for 10 minutes to 3 hours, A desired printed circuit board can be obtained.

  When the curable resin composition of the present invention is used as a resist ink, for example, a cationic polymerization catalyst is used as a curing agent for the curable resin composition, and a pigment, talc, and filler are further added to form a resist ink composition. After making it into a product, after applying on a printed board by a screen printing method, a method of forming a resist ink cured product can be mentioned.

  When the curable resin composition of the present invention is used as a conductive paste, for example, a method of dispersing fine conductive particles in the curable resin composition to obtain a composition for anisotropic conductive film, liquid at room temperature And a paste resin composition for circuit connection and an anisotropic conductive adhesive.

  As a method for obtaining an interlayer insulating material for a build-up substrate from the curable resin composition of the present invention, for example, the curable resin composition appropriately blended with rubber, filler, etc., spray coating method on a wiring board on which a circuit is formed, After applying using a curtain coating method or the like, it is cured. Then, after drilling a predetermined through-hole part etc. as needed, it treats with a roughening agent, forms the unevenness | corrugation by washing the surface with hot water, and metal-treats, such as copper. As the plating method, electroless plating or electrolytic plating treatment is preferable, and examples of the roughening agent include an oxidizing agent, an alkali, and an organic solvent. Such operations are sequentially repeated as desired, and a build-up base can be obtained by alternately building up and forming the resin insulating layer and the conductor layer having a predetermined circuit pattern. However, the through-hole portion is formed after the outermost resin insulating layer is formed. In addition, a resin-coated copper foil obtained by semi-curing the resin composition on the copper foil is thermocompression-bonded at 170 to 250 ° C. on a circuit board on which a circuit is formed, thereby forming a roughened surface and plating treatment. It is also possible to produce a build-up substrate by omitting the process.

  The method for producing an adhesive film for buildup from the curable resin composition of the present invention is, for example, a multilayer printed wiring board in which the curable resin composition of the present invention is applied on a support film to form a resin composition layer. And an adhesive film for use.

  When the curable resin composition of the present invention is used for a build-up adhesive film, the adhesive film is softened under the temperature condition of the laminate in the vacuum laminating method (usually 70 ° C. to 140 ° C.), and simultaneously with the lamination of the circuit board, It is important to show fluidity (resin flow) that allows resin filling in via holes or through holes present in a circuit board, and it is preferable to blend the above-described components so as to exhibit such characteristics.

  Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually preferable to allow resin filling in this range. When laminating both surfaces of the circuit board, it is desirable to fill about 1/2 of the through hole.

  Specifically, the method for producing the adhesive film described above is, after preparing the varnish-like curable resin composition of the present invention, coating the varnish-like composition on the surface of the support film (Y), Further, it can be produced by drying the organic solvent by heating or blowing hot air to form the layer (X) of the curable resin composition.

  The thickness of the formed layer (X) is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  In addition, the layer (X) in this invention may be protected with the protective film mentioned later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  The above-mentioned support film and protective film are made of polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester such as polyethylene naphthalate, polycarbonate, polyimide, and further. Examples thereof include metal foil such as pattern paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. Moreover, it is preferable that the thickness of a protective film shall be 1-40 micrometers.

  The support film (Y) described above is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled after the adhesive film is heat-cured, adhesion of dust and the like in the curing process can be prevented. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance.

  Next, the method for producing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when the layer (X) is protected by a protective film, after peeling these layers ( X) is laminated on one side or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum laminating method. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

Lamination conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C., a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m 2), and air pressure. Lamination is preferably performed under a reduced pressure of 20 mmHg (26.7 hPa) or less.

  The method for obtaining the cured product of the present invention may be based on a general curing method for a curable resin composition, but for example, the heating temperature condition may be appropriately selected depending on the kind of curing agent to be combined and the use. However, what is necessary is just to heat the composition obtained by the said method in the temperature range about 20-250 degreeC.

  Therefore, by using the epoxy resin, the solvent solubility of the epoxy resin is dramatically improved, and when it is made into a cured product, there is little change in heat resistance after the heat history, and a low thermal expansion coefficient can be expressed. Applicable to printed wiring board materials. In addition, the epoxy resin can be easily and efficiently manufactured by the manufacturing method of the present invention, and a molecular design corresponding to the target level of performance described above becomes possible.

  Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on mass unless otherwise specified. The melt viscosity at 150 ° C. and GPC, NMR and MS spectra were measured under the following conditions.

1) Softening point measurement method: JIS K7234

2) GPC: Measurement conditions are as follows.
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (differential refractometer)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.
(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).
3) ¹³ C-NMR: Measurement conditions are as follows.
Device: AL-400 manufactured by JEOL Ltd.
Measurement mode: SGNNE (1H complete decoupling method of NOE elimination)
Solvent: Dimethyl sulfoxide pulse angle: 45 ° C pulse Sample concentration: 30 wt%
Integration count: 10,000 times 4) MS: JEOL Ltd. JMS-T100GC

Example 1
In a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 216 parts (1.5 mol) of β-naphthol, 243 parts of isopropyl alcohol, 195 parts of a 37% formalin aqueous solution (2.40 mol) , 49 parts of sodium hydroxide (61 parts, 0.75 mol) was added, the temperature was raised from room temperature to 75 ° C. with stirring, and the mixture was stirred at 75 ° C. for 1 hour. Subsequently, 216 parts (1.5 mol) of α-naphthol was charged and further stirred at 75 ° C. for 1 hour. After completion of the reaction, 90 parts by mass of first sodium phosphate was added for neutralization, 922 parts of methyl isobutyl ketone was added, and after washing three times with 230 parts by mass of water, the mixture was dried under heating and reduced pressure to obtain a naphthol resin ( B-1) 438 parts by mass were obtained. The hydroxyl group equivalent of the obtained naphthol resin (B-1) was 154 g / equivalent.

  Next, 154 parts by mass of a naphthol resin (B-1) obtained by the above reaction (1.0 equivalent of hydroxyl group) and 463 parts by mass of epichlorohydrin (5) while purging a flask equipped with a thermometer, a condenser and a stirrer with nitrogen gas purge. 0.0 mol) and 53 parts by mass of n-butanol were charged and dissolved while stirring. After the temperature was raised to 50 ° C., 220 parts by mass of a 20% aqueous sodium hydroxide solution (1.10 mol) was added over 3 hours, and the reaction was further continued at 50 ° C. for 1 hour. After completion of the reaction, stirring was stopped, the aqueous layer accumulated in the lower layer was removed, stirring was resumed, and unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. Then, 300 parts by mass of methyl isobutyl ketone and 50 parts by mass of n-butanol were added to the resulting crude epoxy resin and dissolved. Further, 15 parts by mass of a 10% by mass sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours, and then washing with 100 parts by mass of water was repeated three times until the pH of the cleaning solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after microfiltration, the solvent was distilled off under reduced pressure to obtain 200 parts by mass of the desired epoxy resin (A-1). The obtained epoxy resin (A-1) has an epoxy equivalent of 236 g / equivalent and a softening point of 114 ° C. The GPC chart is shown in FIG. 1, the NMR chart is shown in FIG. 2, and the MASS chart is shown in FIG. From the GPC chart, the content of the trimer (x1) is 25.2%, the content of the dimer (x2) is 5.3%, the content of the calixarene compound (x3) is 7.6%, and the high molecular weight The content rate of body (x4) was 61.9%.

Example 2
Except for changing to 108 parts β-naphthol (0.75 mol), 182 parts isopropyl alcohol, 213 parts (2.62 mol) 37% formalin aqueous solution, 46 parts (0.56 mol) 49% sodium hydroxide. In the same manner as in Example 1, 198 parts by mass of epoxy resin (A-2) was obtained. The obtained epoxy resin (A-2) has an epoxy equivalent of 240 g / equivalent and a softening point of 133 ° C., and a GPC chart is shown in FIG. From the GPC chart, the content of the trimer (x1) is 15.7%, the content of the dimer (x2) is 3.1%, the content of the calixarene compound (x3) is 32.7%, and the high molecular weight The content rate of body (x4) was 48.5%.

Example 3
A flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube, and a stirrer was charged with 115 parts (0.80 mol) of β-naphthol, 173 parts (1.20 mol) of α-naphthol, and a softening point of 75 ° C ( B & R method) 54 parts by mass of cresol novolak resin (number of moles of cresol skeleton: 0.45 mol), 130 parts of isopropyl alcohol, 140 parts (1.72 mol) of 37% formalin aqueous solution, 5 parts of 49% sodium hydroxide (0 0.06 mol), the temperature was raised from room temperature to 75 ° C. with stirring, and the mixture was stirred at 75 ° C. for 2 hours. After completion of the reaction, 10 parts by mass of sodium phosphate monobasic was added to neutralize, 727 parts of methyl isobutyl ketone was added, washing was repeated 3 times with 182 parts by mass of water, dried under heating under reduced pressure, and naphthol resin ( B-2) 350 mass parts was obtained. The hydroxyl group equivalent of the obtained naphthol resin (B-2) was 148 g / equivalent.
The epoxidation step was carried out in the same manner as in Example 1 to obtain 204 parts by mass of the target epoxy resin (A-3). The obtained epoxy resin (A-3) has an epoxy equivalent of 231 g / equivalent and a softening point of 114 ° C., and a GPC chart is shown in FIG. From the GPC chart, the content of the trimer (x1) is 16.7%, the content of the dimer (x2) is 3.9%, the content of the calixarene compound (x3) is 13.3%, and the high molecular weight The content rate of body (x4) was 66.1%.

Example 4
Except having changed into (beta) -naphthol 144 parts (1.00 mol) and (alpha) -naphthol 144 parts (1.00 mol), it carried out similarly to Example 3, and obtained 199 mass parts of epoxy resins (A-4). The obtained epoxy resin (A-4) has an epoxy equivalent of 230 g / equivalent and a softening point of 106 ° C., FIG. 6 shows a GPC chart, FIG. 7 shows an NMR chart, and FIG. 8 shows a MASS chart. From the GPC chart, the content of the trimer (x1) is 23.6%, the content of the dimer (x2) is 6.4%, the content of the calixarene compound (x3) is 5.6%, and the high molecular weight The content rate of the body (x4) was 64.4%.

Comparative Synthesis Example 1
A flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube and a stirrer was charged with 505 parts by mass of α-naphthol (3.50 mol), 158 parts by mass of water, and 5 parts by mass of oxalic acid. The mixture was stirred while raising the temperature in 45 minutes. Subsequently, 177 parts by mass (2.45 mol) of a 42 mass% formalin aqueous solution was added dropwise over 1 hour. After completion of dropping, the mixture was further stirred at 100 ° C. for 1 hour, and then heated to 180 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 498 parts by mass of naphthol resin (B-3). The hydroxyl group equivalent of the obtained naphthol resin (B-3) was 154 g / equivalent.
Next, 154 parts by mass of naphthol resin (B-3) obtained by the above reaction (1.0 equivalent of hydroxyl group) was applied in the same manner as in Example 1 while purging a flask equipped with a thermometer, a condenser, and a stirrer with nitrogen gas purge. Thus, 202 parts by mass of an epoxy resin (A-5) was obtained. The epoxy equivalent of the obtained epoxy resin (A-5) is 237 grams / equivalent, and the GPC chart is shown in FIG. From the GPC chart, the contents of trimer (x1), dimer (x2), and calixarene compound (x3) were each 0.0%.

Comparative Synthesis Example 2
In a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 216 parts (1.50 mol) of β-naphthol, 54 parts (0.37 mol) of α-naphthol, 130 parts of isopropyl alcohol, The mixture was charged with 122 parts (1.50 mol) of 37% formalin aqueous solution and 5 parts (0.06 mol) of 49% sodium hydroxide, heated from room temperature to 75 ° C. with stirring, and stirred at 75 ° C. for 2 hours. Thereafter, in the same manner as in Example 1, 200 parts by mass of the target epoxy resin (A-6) was obtained. The epoxy equivalent of the obtained epoxy resin (A-6) is 238 grams / equivalent, and the GPC chart is shown in FIG. From the GPC chart, the content of the trimer (x1) was 30.5%, the content of the dimer (x2) was 35.8%, and the content of the calixarene compound (x3) was 0.0%. .

Examples 5 to 8 and Comparative Examples 1 and 2 [Evaluation of solvent solubility]
10 parts by mass of the epoxy resin and 4.3 parts by mass of methyl ethyl ketone obtained in the above Examples and Comparative Synthesis Examples were dissolved in a sealed state at 60 ° C. in a sample bottle. Then, it cooled to 25 degreeC and evaluated whether the crystal | crystallization precipitated. When the crystal did not precipitate, it was judged as ○, and when the crystal was precipitated, it was judged as ×. The results are shown in Table 1.

Examples 9 to 12, Comparative Examples 3 and 4
According to the formulation shown in Table 2 below, as a curing agent, phenol novolak resin (“TD-2090” manufactured by DIC Corporation, hydroxyl equivalent: 105 g / eq), epoxy resins (A-1) to (A-6), 2-Ethyl-4-methylimidazole (2E4MZ) was blended as a curing accelerator, and methyl ethyl ketone was blended and adjusted so that the nonvolatile content (NV) of each composition was finally 58% by mass.
Subsequently, it was hardened on the following conditions, the laminated board was made as an experiment, and the thermal expansion coefficient and the heat resistance change by a thermal history were evaluated by the following method. The results are shown in Table 2.

<Laminate production conditions>
Base material: Glass cloth “# 2116” (210 × 280 mm) manufactured by Nitto Boseki Co., Ltd.
Number of plies: 6 Condition of prepreg: 160 ° C
Curing conditions: 200 ° C., 40 kg / cm ² for 1.5 hours, post-molding plate thickness: 0.8 mm
<Heat resistance change due to thermal history (amount of change in heat resistance: ΔTg): DMA (Tg difference between first measurement and second measurement)>
Using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device “RSAII” manufactured by Rheometric, rectangular tension method; frequency 1 Hz, temperature rising rate 3 ° C./min), elastic modulus change twice under the following temperature conditions Was measured at the temperature (Tg) at which the tan δ was maximized (the tan δ change rate was largest).
Temperature conditions 1st measurement: temperature rise from 35 ° C. to 275 ° C. at 3 ° C./min 2nd measurement: temperature rise from 35 ° C. to 330 ° C. at 3 ° C./min Each obtained temperature difference was evaluated as ΔTg.

<Coefficient of thermal expansion>
The laminate was cut into a size of 5 mm × 5 mm × 0.8 mm, and a thermomechanical analysis was performed in a compression mode using a thermomechanical analyzer (TMA: SS-6100 manufactured by Seiko Instruments Inc.) as a test piece. .
Measurement conditions Measurement weight: 88.8mN
Temperature increase rate: 2 times at 10 ° C / minute Measurement temperature range: -50 ° C to 300 ° C
The measurement under the above conditions was carried out twice for the same sample, and the average linear expansion coefficient in the temperature range of 40 ° C. to 60 ° C. in the second measurement was evaluated as the thermal expansion coefficient.

表２中の略号は以下の通りである。
ＴＤ−２０９０：フェノールノボラック型フェノール樹脂（ＤＩＣ(株)製「ＴＤ−２０９０」、水酸基当量：１０５ｇ／ｅｑ）
２Ｅ４ＭＺ：硬化促進剤（２−エチル−４−メチルイミダゾール）

Abbreviations in Table 2 are as follows.
TD-2090: Phenol novolac type phenol resin (“TD-2090” manufactured by DIC Corporation, hydroxyl equivalent: 105 g / eq)
2E4MZ: Curing accelerator (2-ethyl-4-methylimidazole)

Claims (7)

An epoxy resin obtained by polyglycidyl etherification of a polycondensation product of an α-naphthol compound, a β-naphthol compound, and formaldehyde, in which the following structural formula (1)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
A trimer (x1) represented by:
The following structural formula (2)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and Gr represents a glycidyl group.)
And the content of the trimer (x1) is 15 to 35% as an area ratio in GPC measurement, and the dimer An epoxy resin characterized in that the content of (x2) is 1 to 25% in terms of area ratio in GPC measurement. In addition to the trimer (x1) and the dimer (x2), the following structural formula (3)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, Gr represents a glycidyl group, and n is a repeating group. It is a unit and is an integer of 2 to 10.)
The epoxy resin of Claim 1 which contains the calixarene compound (x3) represented by these in the ratio which becomes 1 to 40% by the area ratio in GPC measurement in an epoxy resin. The epoxy resin according to claim 1 or 2, wherein the epoxy equivalent is in the range of 210 to 300 g / eq. The epoxy resin according to any one of claims 1 to 3, wherein a softening point is in a range of 95 to 140 ° C. A curable resin composition comprising the epoxy resin according to any one of claims 1 to 4 and a curing agent as essential components. A cured product obtained by curing reaction of the curable resin composition according to claim 5. A printed wiring board obtained by impregnating a reinforcing base material with a resin composition obtained by further blending an organic solvent with the curable resin composition according to claim 5 and superimposing a copper foil thereon, followed by thermocompression bonding.

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