JP2010229171A - Epoxy resin composition for printed wiring board, prepreg for printed wiring board, metal clad laminate for printed wiring board and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition exerting improved adhesion to a circuit, heat resistance and flame retardancy in a printed wiring board. <P>SOLUTION: The epoxy resin composition for a printed circuit board includes at least: (A) an epoxy resin containing both nitrogen and bromine within the same molecule; (B) an amine hardener comprising nitrogen and active hydrogen within the molecule as a hardener; (C) a bromine-free epoxy resin other than (A); and (D) an aromatic bromine compound that contains no functional group such as epoxy group and active hydrogen within the molecule and contains ≥65 mass% bromine atom, provided that the total amount of bromine in all organic resin components is ≥10 mass%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition, a prepreg and a metal-clad laminate used as a material for a printed wiring board, and a printed wiring board produced using these materials.

  A prepreg used as a material for a printed wiring board is obtained by diluting a resin composition mainly composed of a thermosetting resin such as an epoxy resin with a solvent to make a varnish, and impregnating a substrate such as a glass cloth with this varnish. It is produced by drying this to change the resin from an uncured state (A-stage) to a semi-cured state (B-stage). And after cutting the prepreg obtained in this way to a predetermined size, a required number of sheets are stacked and a metal foil such as a copper foil is stacked on one or both sides, and this is heated and pressed to form a laminate, thereby producing a printed wiring board. It is possible to produce a metal-clad laminate that is processed into At this stage, the resin changes from the semi-cured state (B-stage) to the fully cured state (C-stage), and forms an insulating layer together with the base material.

  Here, as a typical resin composition used when preparing a prepreg, a composition in which a curing agent, a curing aid, and further an inorganic filler are blended with an epoxy resin as a main component is known. ing. In order to improve the properties and performance of the cured product as a resin composition for a printed wiring board, various ideas have been made on the types and blends of the composition components.

  As such contrivances and improvements, an epoxy resin composition has been proposed that is excellent in adhesion to a metal circuit from a metal foil such as copper foil, and has good heat resistance and flame retardancy. For example, in a resin composition containing an epoxy resin and dicyandiamide as an amine-based curing agent, a combination of a brominated bisphenol A type epoxy resin and a brominated polyfunctional epoxy resin is proposed (Patent Document 1). ing. This blending is more effective than the conventionally known addition of a low-molecular flame retardant such as an organic bromine compound.

  On the other hand, the use of an epoxy resin containing an oxazolidone ring together with a bromine atom in the same molecule (Patent Document 2) and the use of a brominated epoxy resin modified with an aromatic diisocyanate (Patent Document 3) have also been proposed. . Thus, when a resin containing nitrogen in its molecular structure is used in the epoxy resin, the Tg (glass transition temperature) of the cured product reacted with the curing agent tends to be high. Therefore, it is useful for applications of electronic materials.

  However, when using a resin containing both nitrogen and bromine in the molecular structure as described above, the cured product that has reacted with the amine curing agent tends to have a low thermal decomposition temperature.

  Therefore, in order to ensure flame retardancy, the heat resistance of the epoxy resin composition containing both nitrogen and bromine is deteriorated. This phenomenon is considered to be because the nitrogen atom generally has a high polarity and basic characteristics, and therefore promotes dissociation of bromine during heating.

JP-A-9-316301 JP-A-5-43655 Japanese Patent Laid-Open No. 2002-223048

  The present invention has been made in view of the above points, and further takes advantage of the epoxy resin having both a nitrogen atom and a bromine atom in the same molecule to improve the adhesion to the circuit and to provide flame resistance as well as heat resistance. It is an object of the present invention to provide an epoxy resin composition for printed wiring boards that can improve the heat resistance and is excellent in heat resistance and flame retardancy. Moreover, this invention makes it the subject to provide the prepreg by this epoxy resin composition, the metal-clad laminated board manufactured using these materials, and a printed wiring board.

  The epoxy resin composition for a printed wiring board according to the present invention is characterized by the following in order to solve the above problems.

First: In an epoxy resin composition containing an epoxy resin and an amine curing agent, at least the following components:
(A) Epoxy resin containing both nitrogen and bromine in the same molecule (B) Amine-based curing agent containing nitrogen and active hydrogen in the molecule as a curing agent (C) Resin that does not contain bromine in epoxy resins other than A (D) As a flame retardant, it contains an aromatic bromine compound that does not have a functional group such as an epoxy group or active hydrogen in the molecule and contains 65% by mass or more of bromine atoms, and bromine is contained in all organic resin components. The total amount is 10% by mass or more.

  Second: The bromine content of the epoxy resin (A) is in the range of 16 to 26% by mass.

  Third: total bromine content in the resin composition: X parts by mass, bromine content contained in (A): Y parts by mass, bromine content contained in (D): Z parts by mass, X = Y + Z and Y / X = 0.3 to 0.8.

  Fourth: The epoxy resin (A) has a bifunctional center in the range of 1.8 to 2.5 average epoxy functional groups in one molecule, and an epoxy equivalent of 300 to 390 g / eq.

  Fifth: The amine-based curing agent (B) is dicyandiamide.

  Sixth: The amine-based curing agent (B) is diaminodiphenylmethane.

  Seventh: The epoxy resin (C) is a polyfunctional epoxy resin having an average functional number of 3 or more in the molecule.

  Eighth: The epoxy resin (C) is a cresol novolac type epoxy resin.

  Ninth: The thermal decomposition temperature of the flame retardant (D) is 315 ° C. or higher.

  Tenth: The flame retardant (D) is incompatible with the epoxy resins (A) and (C).

  Eleventh: The flame retardant of (D) is ethane-1,2-bis (pentabromo-phenyl).

  Further, the present invention provides a printed wiring board prepreg in which one of the above epoxy resin compositions is impregnated into a glass cloth to form a B stage, and the printed wiring board in which the prepreg is laminated and integrated with a metal foil. A metal-clad laminate and a printed wiring board in which a circuit is formed from the metal-clad laminate for a printed wiring board are also provided.

  According to the composition of the first invention, at least the specific components (A), (B), (C), and (D) are contained as essential components, and a nitrogen atom is contained in the same molecule of (A). By using an epoxy resin containing both bromine atoms in combination with an epoxy resin of (C) different from this, bromine in the resin component has a specific ratio of 10 mass or more, and further, (D) non-reactive type bromine content A large aromatic bromine compound containing 65% by mass or more of bromine atoms is blended as a flame retardant. As a result, in the printed wiring board, the circuit adhesiveness, the heat resistance mainly including the thermal decomposition temperature with high Tg, and the flame retardancy are improved.

  According to the 2nd and 3rd invention which makes content of a bromine into a specific range, heat resistance and adhesiveness are improved more reliably as a remarkable thing with a flame retardance.

  In 4th invention, adhesiveness (copper foil peel characteristic etc.) improves more by making the functionality of the epoxy resin of a component (A) peculiar.

  In addition, according to the fifth and sixth inventions in which the amine-based curing agent (B) is of a specific type, the adhesiveness and heat resistance are more reliably realized.

  According to the seventh and eighth inventions in which the epoxy resin (C) is multifunctional, the Tg and the heat resistance are significantly improved.

  Furthermore, in the epoxy resin compositions of the ninth to eleventh inventions that specify this as the flame retardant (D), the improvement in heat resistance as well as flame retardancy is surely and remarkable.

  Further, according to the twelfth to fourteenth inventions, there are provided a prepreg, a metal-clad laminate, and a printed wiring board that achieve the above-described excellent effects.

  Embodiments of the present invention will be described below.

  As described above, the epoxy resin composition for a printed wiring board according to the present invention contains an epoxy resin, a curing agent, and a flame retardant, and particularly has a specific epoxy resin (A) (C) as an essential component, and curing. An amine-based curing agent (B) as described later is used as the agent, and an aromatic bromine compound (D) as described later is used as the flame retardant.

  In the present invention, the epoxy resin contains (A) an epoxy resin containing both a nitrogen atom and a bromine atom in the same molecule, and (C) another epoxy resin containing at least an epoxy resin not containing bromine. is there. As the former (A) epoxy resin, for example, an isocyanate-modified bromobisphenol A type epoxy resin obtained by reacting an isocyanate compound with a bromobisphenol A type compound and further a non-bromobisphenol A type compound as a representative example is given as a representative example. It is done. Such (A) epoxy resin can use 1 type (s) or 2 or more types. These (A) epoxy resins are also available as commercial products.

  As the latter (C) epoxy resin, for example, an epoxy resin such as a cresol novolak type epoxy resin, a bisphenol F type epoxy resin, a phenol novolak type epoxy resin or the like can be used. One or more of these epoxy resins can be mixed and used. However, it is necessary that all organic resin components contain 10% by mass or more of bromine as a total amount. Moreover, generally, it is suitably considered that the epoxy resin is blended in an amount of 50 to 90% by mass with respect to the total amount of the composition.

  Preferably, (A) as an epoxy resin having both a nitrogen atom and a bromine atom in the same molecule, an epoxy resin having a bromine content of 16 to 26% by mass is used. If it does in this way, the heat resistance of a laminated board, such as a printed wiring board, and adhesiveness can be improved. In addition, (A) an epoxy resin having both a nitrogen atom and a bromine atom in the same molecule and having a bromine content of 16 to 26% by mass as a bifunctional center (the average number of epoxy functional groups in one molecule is 1.8). By using a resin having an epoxy equivalent of 300 to 390 g / eq in -2.5), the heat resistance and the adhesiveness can be further improved.

  More preferably, in the present invention, the total bromine content in the resin composition: X parts by mass, (A) the bromine content contained in the epoxy resin having both nitrogen atoms and bromine atoms in the same molecule: Y parts by mass, (D) When there is no functional group such as an epoxy group or active hydrogen in the molecule, and the bromine content contained in the aromatic bromine compound flame retardant containing 65% by mass or more of bromine atoms: Z parts by mass, An epoxy resin composition in which X = Y + Z and Y / X = 0.3 to 0.8 is used. If it does in this way, while heat resistance can be improved further, an adhesive characteristic and a flame retardance can be improved. If Y / X is less than 0.3 or greater than 0.8, the flame retardancy and adhesive properties of the laminate may be impaired.

  In the present invention, (B) the amine curing agent is not particularly limited, but one containing nitrogen and active hydrogen in the molecule is used. For example, aromatic amines such as dicyandiamide, diaminodiphenylmethane, diaminodiphenyl ether, metaphenylenediamine, paraphenylenediamine, and diaminodiphenylsulfone are exemplified. More preferably, by using dicyandiimide, it is possible to enhance adhesive properties and heat resistance. In addition, heat resistance can be further improved by using diaminodiphenylmethane.

  About these amine type hardening | curing agents, although it does not specifically limit, the compounding quantity shall be in the range of 0.5-50 mass% in the total amount with the epoxy resin of this invention, Furthermore, 1- It is preferable to be within the range of 20% by mass.

  Moreover, you may use a hardening accelerator together as needed. Examples of the curing accelerator include imidazole compounds and organic phosphorus compounds. When such a curing accelerator is used, it is generally considered that the amount is within a range of 0.01 to 1% by mass with respect to the total amount of the epoxy composition of the present invention.

  The aromatic bromine compound as a flame retardant (D), which is an essential component in the epoxy resin composition of the present invention, has a functional group such as an epoxy group or an active hydrogen group in the molecule other than the bromine atom. Absent. Moreover, it has 65 mass% or more of bromine atoms.

  Such a flame retardant aromatic bromine compound preferably has a thermal decomposition temperature of 315 ° C. or higher, or is incompatible with the epoxy resins (A) and (C). For example, the bromide of bisphenylalkylene is considered, among others:

And ethane-1,2-bis (pentabromo-phenyl) represented by the formula:

  Moreover, in the epoxy resin composition of this invention, you may mix | blend an inorganic filler in the range of 5-120 mass parts with respect to 100 mass parts of organic resins. It is also considered that heat resistance and flame retardancy are thereby made more effective.

  Examples of such inorganic fillers include aluminum hydroxide (preferably an average particle size of 2.5 to 6 μm), talc (preferably an average particle size of 1.0 to 6.0 μm), and spherical silica (preferably an average particle size of 0). .2 to 2.0). It is also considered that the spherical silica is subjected to a surface treatment with an epoxysilane compound or the like.

  And an epoxy resin varnish can be prepared by mix | blending a solvent with the above epoxy resin compositions. Solvents include ketones such as acetone and methyl ethyl ketone (MEK), amides such as formamide and N, N-dimethylformamide, ethers such as ethylene glycol monomethyl ether (MC), and aromatic hydrocarbons such as benzene and toluene. Etc. can be illustrated.

  A prepreg can be produced by impregnating the epoxy resin varnish thus prepared into a base material and drying by heating. As the substrate, cloth, mat, non-woven fabric, paper such as kraft paper, linter paper, etc. using fibers such as glass fiber, aramid fiber, polyester fiber and nylon fiber can be used.

  Heat drying conditions are preferably 130 to 190 ° C. and about 2 to 60 minutes. The amount of prepreg resin is of course not limited, but adjustment to 30 to 60% by weight is preferable because a laminate having good moldability and heat resistance can be obtained. Then, by stacking a plurality of prepregs produced as described above, and further overlaying a metal foil such as copper foil, aluminum, nickel, etc. on one or both sides as necessary, for example, for printed wiring boards A metal-clad laminate can be produced. The heating and pressing conditions at this time are preferably 150 to 190 ° C., 1.5 to 5 MPa, and about 20 to 120 minutes. A printed wiring board can be produced by etching the metal foil on the surface of the laminated board thus obtained. Moreover, a multilayer printed wiring board can be produced by using a circuit-formed product as an inner layer.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  Nitrogen-containing brominated epoxy resin as epoxy resin (A) ("AER4100" manufactured by Asahi Kasei Chemical Co., Ltd., epoxy equivalent 350, bromine content 16.5 mass%), ("DER593" manufactured by Dow Chemical Co., Ltd., epoxy equivalent) 350 or a bromine content of 16.5% by mass) was used. Moreover, as a comparative example, an epoxy resin that does not contain nitrogen but contains bromine (“1121N” manufactured by Dainippon Ink Co., Ltd., epoxy equivalent 495, bromine content 21 mass%).

  In addition, as the epoxy resin containing no bromine (C), a cresol novolac type epoxy resin (“N-690” manufactured by Dainippon Ink Co., Ltd., epoxy equivalent 215) or a trifunctional epoxy resin (manufactured by Mitsui Petrochemical Co., Ltd.) “VG3101”, epoxy equivalent 210) was used.

  As the curing agent, dicyandiamide (reagent product, hydroxyl equivalent 21) and diaminodiphenylmethane (reagent product, hydroxyl equivalent 49.5) were used.

  Imidazole (2E4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) was used as a curing accelerator.

  Ethane-1,2-bis (pentabromo-phenyl) (bromine content 82.3%) was used as a flame retardant.

As the solvent, methyl ethyl ketone (MEK), dimethylformamide (DMF), and methoxypropanol (PC) were used.
<Adjustment of resin varnish>
The resin varnish was adjusted as follows. That is, the epoxy resin and the curing agent / curing accelerator were weighed in the amounts shown in Table 1, and these were added to the solvent DMF. At this time, first, the amount of the solvent was adjusted so that the epoxy resin and the curing agent / curing accelerator were 70% by mass. Then, after stirring with a disper for 2 hours, a curing agent and DMF were added, and further stirred with a disper for 2 hours. Thereafter, a flame retardant was added and further stirred for 2 hours with a disper to obtain a resin varnish.
<Preparation of prepreg>
A glass cloth (“2116 type cloth” manufactured by Nitto Boseki Co., Ltd.) is used as a base material. The glass cloth is impregnated with the resin varnish prepared as described above at room temperature, and then a non-contact type heating unit. By heating at about 130-170 ° C., the solvent in the resin varnish was removed by drying, and the resin composition was semi-cured to prepare a prepreg. The amount of resin in the prepreg was adjusted to 100 parts by mass of resin with respect to 100 parts by mass of glass cloth. In the following, the progress of curing was confirmed by gel time. This gel time is obtained by taking a resin from a prepreg and measuring the time until the resin gels on a heat plate at 170 ° C.
<Evaluation items>
The following items were evaluated using the obtained prepreg.

1. Thermal decomposition temperature The prepreg (340 mm × 510 mm) produced as described above was laminated between the roughened surfaces of two copper foils (thickness 35 μm, JTC foil, manufactured by Nikko Gouldfoil Co., Ltd.), and obtained. The obtained laminated board was evaluated according to JIS-C6481.

2. Oven heat resistance The molded laminate was evaluated according to JIS-C6481.

3. Copper foil adhesive strength The molded laminate was evaluated according to JIS-C6481.

4). Glass transition temperature (Tg)
The molded laminate was evaluated according to JIS-C6481.

5). Flame retardancy The molded laminate was evaluated according to the UL method.
<Evaluation results>
The results of evaluation for the above items are as shown in Table 1. Even when compared with the comparative example, it can be seen that the effect of the example of the present invention is remarkable.

Claims (14)

At least the following ingredients:
(A) Epoxy resin containing both nitrogen and bromine in the same molecule (B) Amine-based curing agent containing nitrogen and active hydrogen in the molecule as a curing agent (C) Resin that does not contain bromine in epoxy resins other than A (D) As a flame retardant, it contains an aromatic bromine compound that does not have a functional group such as an epoxy group or active hydrogen in the molecule and contains 65% by mass or more of bromine atoms, and bromine is contained in all organic resin components. An epoxy resin composition for printed wiring boards, comprising a total amount of 10% by mass or more.   2. The epoxy resin composition for a printed wiring board according to claim 1, wherein the bromine content of the epoxy resin (A) is in the range of 16 to 26 mass%.   When the total bromine content in the resin composition: X parts by mass, the bromine content contained in (A): Y parts by mass, and the bromine content contained in (D): Z parts by mass, X = Y + Z The epoxy resin composition for printed wiring boards according to claim 1, wherein Y / X = 0.3 to 0.8.   2. The epoxy resin (A) is bifunctional center having an average number of epoxy functional groups in a molecule of 1.8 to 2.5 and an epoxy equivalent of 300 to 390 g / eq. The epoxy resin composition for printed wiring boards as described in any one of 1 to 3.   The epoxy resin composition for printed wiring boards according to any one of claims 1 to 4, wherein the amine-based curing agent (B) is dicyandiamide.   The epoxy resin composition for printed wiring boards according to any one of claims 1 to 4, wherein the amine-based curing agent (B) is diaminodiphenylmethane.   The epoxy resin for printed wiring boards according to any one of claims 1 to 6, wherein the epoxy resin of (C) is a polyfunctional epoxy resin having an average functional number in the molecule of 3 or more. Composition.   The epoxy resin composition for printed wiring boards according to claim 7, wherein the epoxy resin (C) is a cresol novolac type epoxy resin.   The epoxy resin composition according to any one of claims 1 to 8, wherein a thermal decomposition temperature of the flame retardant (D) is 315 ° C or higher. In Claim 1 thru | or 7, The flame retardant of said (D) is incompatible with epoxy resin (A) (C), The epoxy resin as described in any one of Claim 1 to 9 characterized by the above-mentioned. Composition.   11. The epoxy resin composition for printed wiring boards according to claim 1, wherein the flame retardant of (D) is ethane-1,2-bis (pentabromo-phenyl). .   A prepreg for a printed wiring board, wherein the epoxy resin composition according to any one of claims 1 to 11 is impregnated into a glass cloth to form a B-stage.   A metal-clad laminate for a printed wiring board, wherein the prepreg according to claim 12 is laminated and integrated with a metal foil.   A printed wiring board, wherein a circuit is formed from the metal-clad laminate for a printed wiring board according to claim 13.