JP5516008B2 - Novel epoxy resin, curable resin composition, cured product thereof, and printed wiring board - Google Patents

Description

  The present invention is excellent in heat resistance and low thermal expansion of the obtained cured product, and can be suitably used for printed wiring boards, semiconductor sealing materials, paints, casting applications, and the like, cured products thereof, and novel products It relates to an 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, along with the trend toward miniaturization and higher performance of electronic equipment, there is a significant trend toward higher density due to narrower wiring pitches in 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, high melting point solder that does not use lead has become mainstream due to laws and regulations for environmental problems, etc., and this lead-free solder has a use temperature that is about 20-40 ° C. higher than conventional eutectic solder. Therefore, the curable resin composition is required to have higher heat resistance than ever before.

  As described above, insulating materials for printed wiring boards are required to have high heat resistance and low thermal expansion, and as an epoxy resin material that can meet such demands, for example, the following structural formula

で表される４官能型ナフタレン系エポキシ樹脂が知られている（特許文献１参照）。

The tetrafunctional type naphthalene type epoxy resin represented by these is known (refer patent document 1).

  However, although the tetrafunctional naphthalene-based epoxy resin has a higher crosslink density than a general phenol novolac epoxy resin and exhibits excellent low thermal expansion and heat resistance in a cured epoxy resin, Higher performance is required and further improvements are needed. Furthermore, since the tetrafunctional naphthalene-based epoxy resin has low solubility in a solvent generally used for printed wiring board production, the properties of the cured product are not sufficiently exhibited.

Japanese Patent No. 3137202

  Therefore, the problem to be solved by the present invention is to provide a curable resin composition that exhibits excellent heat resistance and low thermal expansion, and further realizes good solvent solubility, its cured product, heat resistance, and low thermal expansion. The object is to provide an excellent printed wiring board and a novel epoxy resin that provides these performances.

  As a result of intensive studies to solve the above problems, the present inventors have found that a phenol having a carbonyl group obtained by reacting 2,7-dihydroxynaphthalene and formaldehyde under a specific condition and having a novolak skeleton. It was found that an epoxy resin obtained by reacting a resin with epichlorohydrin exhibits excellent heat resistance and low thermal expansion, and further exhibits good solvent solubility, leading to the completion of the present invention. It was.

  That is, the present invention provides the following structural formula (i)

（式中、Ｒは、それぞれ独立して水素原子、炭素原子数１〜４の炭化水素基、又は炭素原子数１〜２のアルコキシ基を示し、Ｘは、それぞれ独立して水素原子又は下記構造式（ｉｉ）

(In the formula, each R independently represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 2 carbon atoms, and each X independently represents a hydrogen atom or the following structure. Formula (ii)

で表される構造部位を表す。但し、Ｘのうちの少なくとも１つは前記構造式（ｉｉ）で表される構造部位であり、また、構造式（ｉｉ）中、Ｒは、それぞれ独立して水素原子、炭素原子数１〜４の炭化水素基、又は炭素原子数１〜２のアルコキシ基であり、ｎは０〜５の整数である。）
で表される分子構造を有することを特徴とする新規エポキシ樹脂に関する。

The structural site represented by However, at least one of X is a structural moiety represented by the structural formula (ii), and in the structural formula (ii), each R is independently a hydrogen atom or a carbon number of 1 to 4 Or an alkoxy group having 1 to 2 carbon atoms, and n is an integer of 0 to 5. )
It has the molecular structure represented by these.

  The present invention further relates to a curable resin composition comprising the above-described novel 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, a curable resin composition that exhibits excellent heat resistance and low thermal expansibility, and realizes good solvent solubility, a cured product thereof, a printed wiring board excellent in heat resistance and low thermal expansibility, and the like A new epoxy resin that gives the performance of can be provided.

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

Hereinafter, the present invention will be described in detail.
The novel epoxy resin of the present invention has the following structural formula (i)

（式中、Ｒは、それぞれ独立して水素原子、炭素原子数１〜４の炭化水素基、又は炭素原子数１〜２のアルコキシ基を示し、Ｘは、それぞれ独立して水素原子又は下記構造式（ｉｉ）

(In the formula, each R independently represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 2 carbon atoms, and each X independently represents a hydrogen atom or the following structure. Formula (ii)

で表される構造部位を表す。但し、Ｘのうちの少なくとも１つは前記構造式（ｉｉ）で表される構造部位であり、また、構造式（ｉｉ）中、Ｒは、それぞれ独立して水素原子、炭素原子数１〜４の炭化水素基、又は炭素原子数１〜２のアルコキシ基であり、ｎは０〜５の整数である。）
で表される分子構造を有することを特徴としている。

The structural site represented by However, at least one of X is a structural moiety represented by the structural formula (ii), and in the structural formula (ii), each R is independently a hydrogen atom or a carbon number of 1 to 4 Or an alkoxy group having 1 to 2 carbon atoms, and n is an integer of 0 to 5. )
It has the molecular structure represented by these.

  That is, in the molecular structure, the following structural formula (i ′)

（式中、破線部はグリシジルオキシ基との結合手を示す。）
で表される構造部位を主骨格として有することから、エポキシ樹脂（Ａ）の化学構造的な非対称性から良好な溶剤溶解性を示すことができる。また、エポキシ基と硬化剤との硬化反応において、カルボニル構造が硬化反応に関与することにより強固な硬化物が得られ、硬化物における耐熱性と低熱膨張性が向上する。更に、前記構造式（ｉ’）で表される構造部位の芳香核に下記構造式（ｉｉ）

(In the formula, the broken line part represents a bond with a glycidyloxy group.)
From the chemical structure asymmetry of the epoxy resin (A), good solvent solubility can be exhibited. Further, in the curing reaction between the epoxy group and the curing agent, the carbonyl structure is involved in the curing reaction, whereby a hardened product is obtained, and the heat resistance and low thermal expansion in the cured product are improved. Furthermore, the following structural formula (ii)

（Ｒは、それぞれ独立して水素原子、炭素原子数１〜４の炭化水素基、又は炭素原子数１〜２のアルコキシ基であり、ｎは０〜５の整数である。）
で表される構造部位を有することから、その硬化物において優れた耐熱性を発現する。

(R is each independently a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 2 carbon atoms, and n is an integer of 0 to 5).
Therefore, the cured product exhibits excellent heat resistance.

  Here, as R in the above structural formulas (i) and (ii), specifically, in addition to a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-butyl group, a t-butyl group, and the like C1-C2 alkoxy groups such as methoxy group, ethoxy group, and the like, but in the present invention, the heat resistance and the low thermal expansion are particularly excellent. , R is preferably a hydrogen atom.

  Therefore, the novel epoxy resin of the present invention has the following structural formulas (i-1) to (i-3).

からなる群から選択されるものであることが硬化物の耐熱性、低熱膨張性の点から好ましい。ここで、前記、構造式（ｉ−１）〜（ｉ−３）中、ｎは０〜５の整数である。

It is preferable from the point which is selected from the group which consists of the heat resistance of a hardened | cured material, and low thermal expansibility. Here, in the structural formulas (i-1) to (i-3), n is an integer of 0 to 5.

  Further, in the present invention, in the structural formula (i), the naphthalene skeleton in the structural formula (ii) has a ratio of 1 to 6 in one molecule of the epoxy resin from the viewpoint of excellent solvent solubility. preferable.

  Moreover, it is preferable that the epoxy equivalent of the novel epoxy resin of this invention is the range of 150-300 g / eq from the point from which heat resistance and a low thermal expansion coefficient become favorable, and especially 155-250 g / eq. It is preferable that it is the range of these.

  The novel epoxy resin of the present invention described in detail above can be produced by a method in which 2,7-dihydroxynaphthalene and formaldehyde are reacted in the presence of an alkali catalyst, and then the resulting reaction product is reacted with epihalohydrin.

  Specifically, a method in which 2,7-dihydroxynaphthalenes and formaldehyde are charged substantially simultaneously and the reaction is carried out by heating and stirring in the presence of an appropriate catalyst, or 2,7-dihydroxynaphthalenes and an appropriate Examples include a method of reacting by adding formaldehyde continuously or intermittently to the catalyst mixture. Here, “substantially simultaneously” means that all raw materials are charged until the reaction is accelerated by heating.

  2,7-Dihydroxynaphthalene used here is 2,7-dihydroxynaphthalene, methyl-2,7-dihydroxynaphthalene, ethyl-2,7-dihydroxynaphthalene, t-butyl-2,7-dihydroxynaphthalene, methoxy- Examples include 2,7-dihydroxynaphthalene and ethoxy-2,7-dihydroxynaphthalene.

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

  Examples of the alkali catalyst used here 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. It is done. As described above, the amount used is preferably in the range of 0.2 to 2.0 times the molar number of 2,7-dihydroxynaphthalene.

  The reaction charge ratio of 2,7-dihydroxynaphthalene and formaldehyde is not particularly limited, but the ratio of 0.6 to 2.0 times the amount of formaldehyde on a molar basis with respect to 2,7-dihydroxynaphthalene In particular, from the viewpoint of excellent balance between the heat resistance and the viscosity of the epoxy resin, the ratio is preferably 0.6 to 1.5 times.

  In carrying out this reaction, an organic solvent can be used as necessary. Specific examples of the organic solvent that can be used include, but are not limited to, methyl cellosolve, isopropyl alcohol, ethyl cellosolve, toluene, xylene, and methyl isobutyl ketone. The amount of the organic solvent used is usually in the range of 0.1 to 5 times the total mass of the raw material charged, and in particular in the range of 0.3 to 2.5 times the structural formula. The structure represented by (i ′) is preferable from the viewpoint of efficient generation. The reaction temperature is preferably in the range of 20 to 150 ° C, more preferably in the range of 60 to 100 ° C. The reaction time is not particularly limited, but is usually in the range of 1 to 10 hours.

  After completion of the reaction, the reaction mixture is neutralized or washed with water until the pH value of the reaction mixture becomes 4-7. What is necessary is just to perform a neutralization process and a water washing process in accordance with a conventional method. For example, when an alkali catalyst is used, an acidic substance such as acetic acid, phosphoric acid or sodium phosphate can be used as a neutralizing agent. After neutralization or washing with water, the organic solvent is distilled off under reduced pressure and the product is concentrated to obtain a carbonyl group-containing phenol compound. In addition, it is more preferable to introduce a microfiltration step in the treatment operation after the reaction is completed because inorganic salts and foreign substances can be purified and removed.

  Subsequently, the objective novel epoxy resin is obtained by making the obtained phenolic compound and epihalohydrin react. Specifically, for example, epihalohydrin is added in a ratio of 2 to 10 times the amount (molar basis) with respect to the number of moles of the phenolic hydroxyl group in the phenolic compound, and further 0.9% relative to the number of moles 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 up to 2.0 times (molar basis) of the basic catalyst 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, alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol, and tertiary butanol, methyl Examples include cellosolves such as cellosolve and ethyl cellosolve, ethers 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, and the solvent, such as toluene and methyl isobutyl ketone, is distilled off under heating and reduced pressure to obtain the desired novel epoxy resin of the present invention.

  Next, the curable resin composition of the present invention comprises the above-described novel epoxy resin and curing agent 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 novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (polyvalent polyphenol with bismethylene group linked to phenol nucleus) 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 novel epoxy resin and the curing agent in the curable resin composition of the present invention is not particularly limited, but the total of epoxy groups of the novel epoxy resin from the point that the obtained cured product characteristics are good. The amount by which the active group in the curing agent is 0.7 to 1.5 equivalents with respect to 1 equivalent 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 above-described novel epoxy resin of the present invention may be used alone as an epoxy resin component, but other epoxy resins may be used as long as the effects of the present invention are not impaired. Good. Specifically, other epoxy resins can be used in combination so that the above-described novel epoxy resin of the present invention is 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 novel 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, etc. 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 novolac 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 high heat resistance, 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, heat resistance and a low coefficient of thermal expansion can be expressed, and it can be applied to the latest 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) Melt viscosity at 150 ° C .: in accordance with ASTM D4287 2) Softening point measurement method: JIS K7234

3) GPC: The measurement conditions are as follows.
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “H _XL -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 refraction diameter)
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).
4) NMR: NMR GSX270 manufactured by JEOL Ltd.
5) MS: Double Density Mass Spectrometer AX505H (FD505H) manufactured by JEOL Ltd.

Example 1
In a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 240 parts (1.50 mol) of 2,7-dihydroxynaphthalene and 85 parts (1.05 mol) of 37% by weight formaldehyde aqueous solution Then, 376 parts of isopropyl alcohol and 88 parts (0.75 mol) of 48% potassium hydroxide aqueous solution were charged, and stirred at room temperature while blowing nitrogen. Then, it heated up at 75 degreeC and stirred for 2 hours. After completion of the reaction, 108 parts of first sodium phosphate was added for neutralization, isopropyl alcohol was removed under reduced pressure, and 480 parts of methyl isobutyl ketone was added. The obtained organic layer was repeatedly washed with 200 parts of water three times, and then methyl isobutyl ketone was removed by heating under reduced pressure to obtain 245 parts of a phenol compound (A-1). The obtained compound (A-1) had a hydroxyl equivalent of 84 grams / equivalent.

Next, 84 parts (hydroxyl group 1.0 equivalent) of the phenol compound (A-1) obtained by the above reaction while applying a nitrogen gas purge to a flask equipped with a thermometer, a condenser, and a stirrer, 463 parts of epichlorohydrin (5.0 parts) Mol) and 53 parts of n-butanol were charged and dissolved. After the temperature was raised to 50 ° C., 220 parts (1.10 mol) of a 20% aqueous sodium hydroxide solution was added over 3 hours, and then further reacted at 50 ° C. for 1 hour. After completion of the reaction, unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. 300 parts of methyl isobutyl ketone and 50 parts of n-butanol were added to the crude epoxy resin thus obtained and dissolved. Further, 15 parts of a 10% by mass sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours. Then, washing with 100 parts of water was repeated three times until the pH of the washing solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after microfiltration, the solvent was distilled off under reduced pressure to obtain 126 parts of the desired epoxy resin (A-2). The resulting epoxy resin (A-2) has a softening point of 95 ° C. (B & R method), a melt viscosity (measurement method: ICI viscometer method, measurement temperature: 150 ° C.) of 9.0 dPa · s, and an epoxy equivalent of 170 g. / Equivalent. The GPC chart of the obtained epoxy resin is shown in FIG. 1, the C ¹³ NMR chart is shown in FIG. 2, and the MS spectrum is shown in FIG. A peak indicating that a carbonyl group was generated in the vicinity of 203 ppm was detected from the C ¹³ NMR chart. Further, 512 peaks having the following structural formula (i-α) are detected from the MS spectrum, and in the structural formula (i), one naphthalene skeleton in the structural formula (ii) is included in one molecule. The 796 peaks shown and 1080 peaks indicating 2 in one molecule were detected.

また、上記エポキシ樹脂（Ａ−２）は、前記構造式（ｉ−α）で表される化合物を１０．５質量％、下記構造式（ｉ−β）

The epoxy resin (A-2) is composed of 10.5% by mass of the compound represented by the structural formula (i-α), and the following structural formula (i-β).

で表される化合物を３９．６質量％、その他オリゴマー成分を４９．９質量％含有するものであった。

39.6% by mass of the compound represented by the formula, and 49.9% by mass of other oligomer components.

Example 2
128 parts of the target epoxy resin (A-3) was obtained in the same manner as in Example 1 except that the 37% formaldehyde aqueous solution was changed to 122 parts (1.50 mol). The resulting epoxy resin (A-3) had a softening point of 98 ° C. (B & R method), a melt viscosity (measurement method: ICI viscometer method, measurement temperature: 150 ° C.) of 18.0 dPa · s, and an epoxy equivalent of 178 grams. / Equivalent. FIG. 4 shows a GPC chart of the obtained epoxy resin, FIG. 5 shows a C ¹³ NMR chart, and FIG. 6 shows an MS spectrum. A peak indicating that a carbonyl group was generated in the vicinity of 203 ppm was detected from the C ¹³ NMR chart. In addition, 512 peaks indicating the structural formula (i-α) are detected from the MS spectrum, and the structural formula (i) further includes one naphthalene skeleton in the structural formula (ii) per molecule. The 796 peak shown, 1080 peak indicating 2 in one molecule, and 1364 peak indicating 3 in 1 molecule were detected.

  The epoxy resin (A-3) is composed of 15.5% by mass of the compound represented by the structural formula (i-α) and 20.7% by mass of the compound represented by the structural formula (i-β). %, And 63.8% by mass of other oligomer components.

Examples 3 and 4 and Comparative Example 1
As the epoxy resin, the epoxy resin (A-2), the epoxy resin (A-3), and the epoxy resin (A-4) for comparison [the following structural formula]

で表される４官能型ナフタレン系エポキシ樹脂（ＤＩＣ(株)製「エピクロンＨＰ−４７００」エポキシ当量１６５グラム/当量）］、硬化剤としてフェノールノボラック型フェノール樹脂（ＤＩＣ(株)製「ＴＤ−２１３１」、水酸基当量：１０４ｇ／ｅｑ）、硬化促進剤としてトリフェニルホスフィン（ＴＰＰ）を用いて表１に示した組成で配合し、１１ｃｍ×９ｃｍ×２．４ｍｍの型枠に流し込み、プレスで１５０℃の温度で１０分間成型した後、型枠から成型物を取り出し、次いで、１７５℃の温度で５時間後硬化して作成した。
耐熱性、線膨張率を評価した。また、前記エポキシ樹脂（Ａ−２）、前記エポキシ樹脂（Ａ−３）、及びエポキシ樹脂（Ａ−４）についての溶剤溶解性を下記の方法で測定した。結果を表１に示す。
＜耐熱性（ガラス転移温度）＞
粘弾性測定装置（ＤＭＡ：レオメトリック社製固体粘弾性測定装置ＲＳＡＩＩ、レクタンギュラーテンション法；周波数１Ｈｚ、昇温速度３℃／ｍｉｎ）を用いて、弾性率変化が最大となる（ｔａｎδ変化率が最も大きい）温度をガラス転移温度として評価した。
＜線膨張係数＞
熱機械分析装置（ＴＭＡ：セイコーインスツルメント社製ＳＳ−６１００）を用いて、圧縮モードで熱機械分析を行った。
測定条件
測定架重：８８．８ｍＮ
昇温速度：３℃／分で２回
測定温度範囲：−５０℃から３００℃
上記条件での測定を同一サンプルにつき２回実施し、２回目の測定における、２５℃から２８０℃の温度範囲における平均膨張係数を線膨張係数として評価した。
＜溶剤溶解性＞
エポキシ樹脂１０部とメチルエチルケトン４．３部をサンプル瓶中、密閉状態６０℃で溶解させた。その後、２５℃まで冷却し、結晶が析出するか評価した。結晶が析出しない場合は○、結晶が析出した場合は×として判定した。

4] a tetrafunctional naphthalene epoxy resin (“Epiclon HP-4700” epoxy equivalent of 165 g / equivalent) manufactured by DIC Corporation) and a phenol novolac type phenol resin (“TD-2131” manufactured by DIC Corporation) as a curing agent. ”, Hydroxyl group equivalent: 104 g / eq), triphenylphosphine (TPP) as a curing accelerator, blended in the composition shown in Table 1, poured into a mold of 11 cm × 9 cm × 2.4 mm, and pressed at 150 ° C. After molding at a temperature of 10 minutes, the molded product was taken out from the mold, and then post-cured at a temperature of 175 ° C. for 5 hours.
Heat resistance and linear expansion coefficient were evaluated. Moreover, the solvent solubility about the said epoxy resin (A-2), the said epoxy resin (A-3), and an epoxy resin (A-4) was measured with the following method. The results are shown in Table 1.
<Heat resistance (glass transition temperature)>
Using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device RSAII manufactured by Rheometric, rectangular tension method; frequency 1 Hz, heating rate 3 ° C./min), the elastic modulus change is maximized (tan δ change rate is the highest). The (large) temperature was evaluated as the glass transition temperature.
<Linear expansion coefficient>
Thermomechanical analysis was performed in a compressed mode using a thermomechanical analyzer (TMA: SS-6100 manufactured by Seiko Instruments Inc.).
Measurement conditions Measurement weight: 88.8mN
Temperature increase rate: 2 times at 3 ° C / minute Measurement temperature range: -50 ° C to 300 ° C
The measurement under the above conditions was performed twice for the same sample, and the average expansion coefficient in the temperature range from 25 ° C. to 280 ° C. in the second measurement was evaluated as the linear expansion coefficient.
<Solvent solubility>
10 parts of epoxy resin and 4.3 parts of methyl ethyl ketone 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 ×.

Example 5 and Comparative Example 2
According to the composition shown in Table 2 below, an epoxy resin and a phenol novolac type phenol resin (“TD-2090” manufactured by DIC Corporation, hydroxyl equivalent: 105 g / eq) as a curing agent and 2-ethyl-4-methyl as a curing accelerator Imidazole (2E4MZ) was blended, and methyl ethyl ketone was blended and adjusted so that the nonvolatile content (NV) of each composition was finally 58 mass%.
Subsequently, it was hardened on the following conditions, the laminated board was made as an experiment, and the heat resistance and the thermal expansion coefficient 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 (glass transition temperature)>
The laminate was cut into a size of 5 mm × 54 mm × 0.8 mm, and this was used as a test piece to measure a viscoelasticity (DMA: solid viscoelasticity measurement device “RSAII” manufactured by Rheometric, rectangular tension method: frequency 1 Hz, rate of temperature increase 3 ° C./min), the temperature at which the elastic modulus change was maximum (the tan δ change rate was the largest) was evaluated as the glass transition temperature.
<Linear expansion coefficient>
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 3 ° C / minute Measurement temperature range: -50 ° C to 300 ° C
The measurement under the above conditions was performed twice for the same sample, and the average expansion coefficient in the temperature range from 240 ° C. to 280 ° C. in the second measurement was evaluated as the linear expansion coefficient.

Claims (6)

The following structural formula (i)

(In the formula, each R independently represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 2 carbon atoms, and each X independently represents a hydrogen atom or the following structure. Formula (ii)

The structural site represented by However, at least one of X is a structural moiety represented by the structural formula (ii), and in the structural formula (ii), each R is independently a hydrogen atom or a carbon number of 1 to 4 Or an alkoxy group having 1 to 2 carbon atoms, and n is an integer of 0 to 5. )
A novel epoxy resin having a molecular structure represented by 2. The novel epoxy resin according to claim 1, which has a molecular structure having 1 to 6 naphthalene skeletons constituting the structural portion represented by the structural formula (ii) in one molecule of the novel epoxy resin. The novel epoxy resin according to claim 1, wherein the epoxy equivalent is in the range of 150 to 300 g / eq. A curable resin composition comprising the novel epoxy resin according to any one of claims 1 to 3 and a curing agent as essential components. A cured product obtained by curing reaction of the curable resin composition according to claim 4. 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 4 and superimposing a copper foil thereon, followed by thermocompression bonding.

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