JP2001278953A - Epoxy resin composition for laminating plate and laminating plate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for lamination plate which hardens promptly, gives a high quality formed article and has good formability, when thermoformed and capable of keeping stable for long time in near the room temperature. SOLUTION: This composition comprises as essential components an epoxy resin (A), an epoxy resin hardening agent (B) selected from a polyamine, a polyphenol or an acid anhydride, and at least one molecular compound (C) having the hardening promotion effect which is selected from the group of compounds which are a molecular associator of a tetra-substituted phosphonium and a dihydric phenol compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for a laminate which can be rapidly cured. More specifically, printed wiring, which quickly cures when heated during molding, can provide a molded article of good moldability and high quality, and can be stably stored at about room temperature for a long period of time. The present invention relates to a resin composition useful for a board, and a prepreg and a laminate using the same.

[0002]

2. Description of the Related Art In recent years, epoxy resin multilayer printed wiring boards have been required to exhibit expected performance by short-time heat molding in order to automate processing equipment, save energy, and further improve productivity. By adding a large amount of catalyst to the varnish, it is possible to perform heat molding for a short time.However, when the amount of catalyst is increased, the curability at the time of heat molding improves, but the melt viscosity at the time of molding increases. The rise is remarkable,
Control becomes difficult in terms of moldability such as embedding into a circuit board. In addition, by increasing the amount of the catalyst, the resin curing reaction proceeds during storage at around room temperature, and the properties are reduced. Thus, it has been difficult to achieve both fast curing at high temperatures, moldability, and room temperature storage stability.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of intensive studies to solve such problems of the epoxy resin composition for a laminated board. An epoxy resin composition for a laminate, which gives a cured product of high quality, has good moldability, and can be stably stored at around room temperature for a long period of time,
Another object of the present invention is to provide a prepreg and a laminate using the same.

[0004]

That is, the present invention provides an epoxy resin (A), an epoxy resin curing agent (B) selected from polyamines, polyphenols and acid anhydrides, and a curing acceleration effect. And it is an epoxy resin composition for laminates containing at least one molecular compound (C) as an essential component selected from the group of compounds represented by the general formulas (1) and (2). Further, a prepreg and a laminate using the resin composition are further provided.

[0005]

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[0006]

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In the formula, P is a phosphorus atom, R ₁ , R ₂ , R ₃ and R ₄ are a substituted or unsubstituted aromatic group or an alkyl group, X is a single bond, or an ether group, a sulfone group or a sulfide group. A divalent substituent selected from a carbonyl group,
Or a divalent organic group having 1 to 13 carbon atoms.

[0008]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the general formula (1)
At least one of the group consisting of the compounds represented by
By using the selected molecular compound (C), it has been possible to achieve both a reduction in the time for heat molding and a long-term storage of the resin composition and the prepreg. In particular, in the B-stage state in which the prepreg is used, the curing speed to the final curing is high at the molding temperature without sacrificing the moldability and the storage stability at room temperature, and the curability, moldability and storage stability are improved. The technical point is to use a latent catalyst that satisfies both advanced and simultaneous requirements.

As the epoxy resin (A) used in the present invention, any resin having two or more epoxy groups, which has been conventionally used for electric insulation, can be used. For example, bisphenol A epoxy resin, bisphenol F epoxy resin, novolak epoxy resin, isocyanurate epoxy resin, glycidylamine epoxy resin, epoxy resin having biphenyl skeleton, epoxy resin having naphthalene skeleton, dicyclopentadiene skeleton An epoxy resin having a limonene skeleton, or a polyfunctional epoxy resin such as a trifunctional or tetrafunctional glycidylamine type epoxy resin, a polyglycidyl ester of a polycarboxylic acid, or a polyglycidyl ester of an aliphatic polyhydroxy compound; A silicone-modified epoxy resin, a rubber-modified epoxy resin, and the like can be given.

Further, in order to impart flame retardancy, a flame-retardant epoxy resin obtained by halogenating the above-mentioned epoxy resin, or a co-condensate of the above-mentioned epoxy resin with tetrabromobisphenol A or bisphenol A; Epoxy resin blended with tetrabromobisphenol A and bisphenol A, epoxy resin blended with diglycidyl ether tetrabromobisphenol A, and the like can also be used.

As the epoxy resin curing agent (B), a compound having a functional group capable of reacting with an epoxy group is used, and polyamines, polyphenols, or acid anhydrides are preferably used. Examples of polyamines include 4,4'-diaminodiphenylmethane, 4,4'-didiaminodiphenylsulfone, metaphenylenediamine,
4,4'-diamino-3,3'-didiethyl-5,5'-di4,4'-
Didimethyldiphenylmethane, 3,3'-didimethoxy-
4,4'-didiaminodiphenyl, 3,3'-didimethyl-4,
4'-di-4,4'-didiaminodiphenyl, 2,2'-didichloro-4,4'-didiamino-5,5'-didimethoxydimethyl, 2,2 ', 5,5'-tetrachloro- 4,4'-didiaminodiphenyl, 4,4'-dimethylenebis (2-chloroaniline), 2,2 ', 3,3'-tetrachloro-4,4'-didiaminodiphenylmethane, 4,4'-didi Aminodiphenyl-
Ter, 4,4'-didiaminobenzanilide, 3,3'-didihydroxy-4,4'-didiaminobiphenyl, 9,9'-dibis (4-aminophenyl) fluorene, 9,9'-dibis ( 4-Aminophenyl) anthracene, ethylenediamine, diethylaminopropylamine, hexamethylenediamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane and the like are exemplified.

When a guanidine derivative is used in combination as a polyamine, it is effective in improving characteristics such as storage stability and curability. Examples of such guanidine derivatives include dicyandiamide, dicyandiamide aniline adduct, dicyandiamide aromatic amine adduct, 1-orthotolyldiguanide, α-2,5-dimethylguanide, α,
ω-diphenyldiguanidide, α, α′-bisguanylguanidinodiphenyl ether, p-chlorophenyldiguanide, α, α′-hexamethylenebis [ω- (p-chlorophenol)] diguanide, phenyldig Examples include anido oxalate, monosubstituted or disubstituted alkyl-modified phenyldiguanide, acetylguanidine, diethylcyanoacetylguanidine and the like.

Examples of the polyphenols include phenol novolak, o-cresol novolak, p-cresol novolak, pt-butylphenol novolak, hydroxynaphthalene novolak, bisphenol A novolak, bisphenol F novolak, terpene-modified novolak, and dicyclopentadiene-modified Novolak, para-xylene-modified novolak, polybutadiene-modified phenol and the like are exemplified.

Examples of acid anhydrides include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, nadic anhydride, chlorendic anhydride and the like. Is an example.

The molecular compound (C) which functions as a curing accelerator in the present invention is a compound represented by the general formulas (1) and (2), and is a molecular aggregate of a tetra-substituted phosphonium and a dihydric phenol compound. is there. This molecular compound is 1
Is composed of three tetra-substituted phosphoniums, three phenolic hydroxyl groups and one phenoxide anion, and around the positive charge of the tetra-substituted phosphonium ion,
It is presumed that three phenolic hydroxyl groups and one phenoxide anion surround and have a stabilized structure. In the formulas (1) and (2), P is a phosphorus atom, X is a single bond, or a divalent substituent selected from an ether group, a sulfone group, a sulfide group, and a carbonyl group, or a group having 1 to 13 carbon atoms. Represents a divalent organic group.

Examples of the phosphonium ion which can have such a structure include a tetra-substituted phosphonium ion having a substituted or unsubstituted aryl group or alkyl group as a substituent.
Tetra-substituted phosphonium which is stable and preferably stable to heat and hydrolysis and forms such an ion is specifically a tetraaryl-substituted phosphonium such as tetraphenylphosphonium or tetratolylphosphonium, benzyltriphenylphosphonium or triphenylmethylphosphonium. Examples include triarylmonoalkylphosphonium, tetrabutylphosphonium, and the like originating from phosphonium halides synthesized from triarylphosphines such as lithium and alkyl halides.

The dihydric phenol compounds which are the other components forming the molecular compound (C) include bisphenol A, bisphenol F, bisphenol S,
Bisphenols such as biphenol, hydroquinone,
Examples thereof include resorcinol and catechol, but from the viewpoints of stability, curability, and physical properties of a cured product of a molecular compound, bisphenol A and bisphenol F (4,4′-methylenebisphenol, 2,4′-methylenebisphenol, 2'-methylenebisphenol or bisphenol F manufactured by Honshu Chemical
Preferred are bisphenol S, 4,4'-biphenol, 2,2'-biphenol.

As a method for obtaining the molecular compound (C) used in the present invention, a dihydric phenol compound as described above is combined with a base which finally helps dehydrohalogenation, such as sodium hydroxide and potassium hydroxide. Organic bases such as alkali metal hydroxides, pyridine and triethylamine
A method of dissolving in a solvent such as alcohol, followed by adding and reacting the tetra-substituted phosphonium halide dissolved in an appropriate solvent, and finally taking out as a solid by an operation such as recrystallization or reprecipitation. A method of reacting a hydroxide of tetra-substituted phosphonium with a dihydric phenol compound in an organic solvent is common. Alternatively, it can be synthesized by a method in which a tetra-substituted borate is thermally reacted with a dihydric phenol compound and then heated and reacted in a solvent such as alcohol.

The molecular compound (C) used in the present invention has a phosphonium-phenoxide-type salt in its structure as described above. This is different from the conventional onium-organic acid anion salt-type compound in that (C) is a point that a higher-order structure due to a hydrogen bond involving a proton of a phenolic hydroxyl group surrounds the ionic bond. In the conventional salt, the reactivity was controlled only by the strength of the ionic bond. On the other hand, in the molecular compound (C), the ion pair of the reaction active site was surrounded by a higher-order structure at room temperature, and the active site was Is protected, while in the actual shaping stage,
The active site is exposed by the collapse of this higher-order structure,
So-called latency, which expresses reactivity, is imparted.

The curing rate of the molecular compound (C) can be easily adjusted by the combination of the tetra-substituted phosphonium and the dihydric phenol compound and the amount added to the epoxy resin composition. It is also advantageous in terms of moldability.

In the resin composition for laminates of the present invention, the compounding amount of the molecular compound (C) to the epoxy resin (A) is 0.01 to 1 with respect to 100 parts by weight of the epoxy resin.
It is desirably 0 parts by weight. If the amount is more than 10 parts by weight, the viscosity rise during molding becomes faster, and the moldability decreases. Further, the preservability of the varnish also deteriorates, and it is difficult to achieve both fast curing properties and moldability / preservability of the varnish. Further, the influence of the decrease in the physical properties accompanying the increase in the added amount cannot be ignored. On the other hand, if the amount is less than 0.01,
Satisfactory fast curability cannot be obtained.

In the resin composition for a laminate of the present invention, the molecular compound (C) acts as a curing accelerator for an epoxy resin, and has conventionally been used as a curing accelerator for an epoxy resin laminate. 2,2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-
It is also possible to use imidazoles such as 4-methylimidazole, 2-methylimidazole / isocyanuric acid adduct, and 2-methylimidazole / trimellitic acid adduct.

As a solvent when the epoxy resin composition of the present invention is used as a varnish, methanol, ethanol, methyl ethyl ketone, ethylene glycol monoethyl ether, dimethylformamide and the like can be used.
Also, a reactive diluent can be used, and examples thereof include n-butyl glycidyl ether, allyl glycidyl ether, styrene oxide, phenyl glycidyl ether, glycidyl methacrylate, diglycidyl ether, and diglycidyl. Examples include aniline, trimethylolpropane triglycidyl ether, and glycerin triglycidyl ether.

The prepreg and laminate of the present invention are prepared by dissolving the epoxy resin composition of the present invention in the above-mentioned solvent to form a varnish, and then varnishing the varnish with paper, glass woven fabric, glass non-woven fabric, Alternatively, it is applied and impregnated on a base material such as a cloth having a component other than glass, and dried in a drying furnace at 80 to 80%.
By drying in the range of 200 ° C., a prepreg can be prepared. Further, this is heated and pressed to produce a laminate or a metal-clad laminate for a printed wiring board.

Depending on the method of application or impregnation in the production process of the prepreg and the laminate, an inorganic filler may be added as necessary to impart thixotropy to the varnish. Examples of inorganic fillers include, for example, aluminum oxide, hydrated silica alumina, antimony oxide, barium titanate, colloidal silica, calcium carbonate, calcium sulfate, mica, silica, silicon carbide, talc, titanium oxide, quartz, zirconium oxide , Zirconium silicate, boron nitride, carbon, graphite and the like.

Further, a coupling agent may be added for improving the adhesion to a metal foil such as copper or the like, or the adhesion to an inorganic filler. As the coupling agent, a silane coupling agent, a titanate coupling agent, an aluminum chelate coupling agent, and the like can be used.For example, chloropropyltrimethoxysilane, vinyltrichlorosilane, γ-glycidoxypropyltrimethoxy Silane, γ-mercaptopropyltrimethoxysilane, N-
β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, isopropyl triisostearoyl titanate, isopropyl trimethacryl titanate, isopropyl tri (dioctyl phyllophosphate) titanate, isopropyl isostearoyl di (4 -Aminobenzoyl) titanate and the like.

[0027]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention.

[Synthesis of Curing Accelerator] First, a molecular compound (C), which is a curing accelerator used in the present invention, is synthesized.
For confirmation of the structure, the phosphonium phenoxide equivalent was measured by NMR measurement, elemental analysis, and neutralization titration. Neutralization titration was performed by the following method.

1. Neutralization Titration (Measurement of Phosphonium Phenoxide Equivalent) The synthesized molecular compound (C) is reacted with an excess of oxalic acid of known weight in a methanol / water-based solvent, and the remaining oxalic acid is dissolved in an aqueous sodium hydroxide solution of known normality. The normality (N / g) per weight of the molecular compound (C) was calculated. The reciprocal of this value is the phosphonium phenoxide equivalent.

(Synthesis Example 1) In a 1-liter separable flask equipped with a stirrer, 40.0 g (0.2 mol) of bisphenol F (BisFD, manufactured by Honshu Chemical Co., Ltd.) was added.
100 ml of methanol was charged and dissolved by stirring at room temperature, and 4.0 g (0.1 mol) of sodium hydroxide was further stirred.
Was previously dissolved in 50 ml of methanol. Next, a solution in which 41.9 g (0.1 mol) of tetraphenylphosphonium bromide was dissolved in 150 ml of methanol in advance was added. Continue stirring for a while,
After the addition of ml of methanol, the solution in the flask was dropped into a large amount of water while stirring to collect a solid content. The precipitate was filtered and dried to obtain 66.6 g of a white powder. This compound is designated as C1.

From the results of NMR, elemental analysis, and neutralization titration, C1 is 751 in which the molar ratio of the tetraphenylphosphonium portion to the bisphenol F unit is 1: 2 and the equivalent of phosphonium phenoxide is close to the theoretical value of 738. I understood that. From this, it was confirmed that the target structure was represented by the general formula (1). The yield of synthesis is 9
It was 1.6%.

(Synthesis Examples 2 to 6) Compound C2 was prepared in the same manner as in Synthesis Example 1 except that the conditions such as the type and amount of the dihydric phenol compound and the phosphonium halide were as shown in Table 1. ~ C6 was prepared. Analysis was performed in the same manner as in Synthesis Example 1, and all of the compounds were represented by general formulas (1) to (1).
It was confirmed that the structure conformed to any of the structures represented by (2). The theoretical and measured values of the phosphonium phenoxide equivalent and the yield of the synthesis are summarized in Table 1.

[0033]

[Table 1]

[Preparation of Multilayer Printed Wiring Board] Next, a multilayer printed wiring board is prepared using the molecular compounds (C1 to C6) obtained in the synthesis examples, and molding during heat molding is performed to evaluate the characteristics. , The glass transition temperature of the obtained laminate, the heat resistance to soldering moisture absorption, and the storage stability of the prepreg were measured. The respective measurement and evaluation methods were as follows.

2. Glass transition temperature Cut off only the prepreg layer from the molded multilayer printed wiring board and use an automatic viscoelasticity measuring device (Orientec Co., Ltd.)
Using RHEOVIBRON DDV-III-EP), the measurement was performed at a frequency of 11 Hz, a temperature rising rate of 5 ° C./min, and a tensile mode. The tan δ peak temperature in the dynamic viscoelasticity curve was defined as the glass transition temperature.

3. Formability The 18 μm outer copper foil of the multilayer printed wiring board after molding is etched and visible from the exposed prepreg layer.
The state of embedding of the resin in the pattern of the inner layer was compared and evaluated visually.

4. Moisture-absorbing solder heat resistance The multilayer printed wiring board is heated at 125 ° C and 2.3 atm (0.23
(MPa) Under a condition of 1 hour, a pressure cooker test (PCT) moisture absorption treatment was performed, and further, the presence or absence of swelling when floating in a solder bath at 260 ° C. for 2 minutes was observed.

5. Preservability of Prepreg The fluidity of the prepreg immediately after coating and drying and the prepreg after storing it at 40 ° C. for 7 days was compared and evaluated by the amount of resin flowing out of the prepreg during pressing.

(Examples 1 to 8) Epoxy resin compositions were prepared by using the molecular compounds (C1 to C6) obtained in Synthesis Examples 1 to 6 and mixing the respective components at the composition ratios shown in Table 2. A solution (varnish) was prepared, and this was 180 μm thick by a standard method.
m was impregnated into a glass fiber cloth substrate and dried at 150 ° C. for 3 minutes to obtain a prepreg.

Next, a separately prepared glass-epoxy double-sided copper-clad laminate having a base material thickness of 0.1 mm and a copper foil thickness of 35 μm was polished and soft-etched to remove rust-proofing treatment, and then a circuit was formed by etching. I let it. This was subjected to an oxidation treatment generally called black treatment to roughen the circuit surface, thereby producing an inner circuit board. The above-mentioned prepreg is laminated one by one on both sides of the obtained inner layer circuit board, and further, a copper foil having a thickness of 18 μm is laminated on both sides thereof one by one, and is heat-formed by a vacuum pressure press to form a multilayer printed wiring. I got a board.
Heat molding starts at room temperature, and the temperature rise rate of the material is 8 ° C /
Minutes. The maximum temperature of the material was 170 ° C., and the time required for molding including heating and cooling was 60 minutes. Table 2 summarizes the results of evaluation of the moldability, the glass transition temperature of the resin of the obtained laminate, the heat resistance to moisture absorption by soldering, and the storage stability of the prepreg.

(Comparative Examples 1 to 8) Each component was blended at a composition ratio as shown in Table 3 to prepare an epoxy resin composition solution.
Impregnation and drying were performed in the same manner as in the example to obtain a prepreg of a comparative example. Using the obtained prepreg, multilayer printed wiring boards were produced in the same manner as in the examples, and various characteristics were evaluated. The evaluation results are shown in Table 3.

[0042]

[Table 2]

[0043]

[Table 3]

The glass transition temperature of the cured resin in each of the examples was 145 ° C. or higher in each case, and all values were higher than those of the comparative examples. In addition, moldability, heat resistance to moisture absorption solder, 4
The fluidity of the prepreg after storage at 0 ° C. for 7 days was also a good result. On the other hand, in the comparative example, all of the fluidity of the prepreg after storage has caused gelation or poor fluidity, and further, regarding the moldability and the moisture absorption solder heat resistance,
Either of them resulted in voids or swelling, resulting in a failure, and none of them was satisfactory.

[0045]

The epoxy resin composition for laminates of the present invention is excellent in curability, can be sufficiently cured even in a short lamination molding time, and has a storage stability near room temperature.
Furthermore, it is excellent in moldability, excellent in storage stability even in a prepreg using the same, and can be suitably used for production of a laminated board or a printed wiring board. In particular, due to its excellent fast-curing properties, for example, it is possible to shorten the heating molding time, which conventionally took 150 minutes or more by one press, to about 60 minutes, and the manufacturing cost is greatly reduced.
The man-hours spent on quality control and inventory control will be greatly reduced. In addition, moldability, varnish preservability, and other physical properties can maintain conventional qualities, and are extremely effective in satisfying both rapid curability at high temperature, moldability, and varnish storability at room temperature.

Claims (3)

[Claims] 1. An epoxy resin (A), an epoxy resin curing agent (B) selected from polyamines, polyphenols and acid anhydrides, and a compound represented by the general formula (1) or (2). An epoxy resin composition for a laminate, comprising, as an essential component, at least one molecular compound (C) selected from the group consisting of: Embedded image Embedded image (However, P is a phosphorus atom, R ₁ , R ₂ , R ₃ and R ₄ are a substituted or unsubstituted aromatic group or an alkyl group, X is a single bond, or an ether group, a sulfone group, a sulfide group, a carbonyl group. Represents a divalent substituent selected from or a divalent organic group having 1 to 13 carbon atoms.) 2. A prepreg, which is basically composed of the epoxy resin composition for a laminate according to claim 1 and a substrate. 3. A laminate, which is basically composed of the epoxy resin composition for a laminate according to claim 1 and a base material.