JP7422046B2 - prepreg - Google Patents

Description

The present invention relates to prepreg. In particular, it relates to a flame retardant that constitutes prepreg.

In recent years, data communications used in information communications have been rapidly increasing in speed and capacity. Therefore, in the above-mentioned electronic devices, there is a demand for a printed wiring board that has both high frequency characteristics and multilayer wiring.

Printed wiring boards used for information communication are required to have low dielectric constant (low Dk) and low dielectric loss tangent (low Df) in order to shorten signal propagation delay and reduce transmission loss. In order to meet these requirements, a resin material containing polyphenylene ether is used as an insulating layer between multilayered wiring in printed wiring boards. Polyphenylene ether is a compound that has excellent electrical properties (low dielectric constant and low dielectric loss tangent) and is expected to be effective in increasing transmission speed and reducing transmission loss. In order to improve the performance and multilayer printed wiring boards, attempts have been made to apply prepreg laminates using polyphenylene ether to printed wiring boards.

In addition, in order to obtain the above electrical properties, a method has been developed in which resin compositions contain resins with low Dk and low Df, such as fluororesins, cyanate ester compounds, polyphenylene ether resins, and vinyl compounds mainly containing styrene. (For example, Patent Document 1). Furthermore, in order to improve the flame retardancy of the above-mentioned resins and compounds, a method has been developed in which a halogen-based compound is included in a resin composition (for example, Patent Document 2).

Japanese Patent Application Publication No. 2002-194212 Japanese Patent Application Publication No. 10-273518

However, the use of halogen compounds poses environmental problems, such as the possibility of generating harmful substances such as dioxins during incineration.

The present invention has been made in view of such problems, and an object of the present invention is to provide a prepreg that does not use halogen-based materials.

The prepreg according to one embodiment of the present invention includes a polyphenylene ether resin composition containing polyphenylene ether, a crosslinked curing agent, and a phosphorus-based compound containing phosphorus, and a base material, and the polyphenylene ether has the general formula (1 )

and has a number average molecular weight of 1000 to 7000, in the general formula (1), X represents an aryl group, (Y) _m represents a polyphenylene ether moiety, and R ¹ , R ² , and R ³ are each Each independently represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, m represents an integer of 1 to 100, n represents an integer of 1 to 6, and q represents an integer of 1 to 4.

Moreover, the phosphorus-based compound may include at least one of a phosphorus epoxy compound, a phosphazene compound, a phosphorus phenol compound, and a phosphorus cyanate compound.

Further, the polyphenylene ether resin composition contains silica, and silica may be contained in an amount of 10 to 100 parts by mass based on 100 parts by mass of the resin composition.

The prepreg according to one embodiment of the present invention includes an epoxy compound having a number average molecular weight of 1,000 or less, having at least two epoxy groups in one molecule and containing no halogen atoms, a polyphenylene ether having a number average molecular weight of 5,000 or less, A polyphenylene ether resin composition comprising a cyanate ester compound, an epoxy compound, a curing catalyst that promotes the reaction of the polyphenylene ether with a cyanate ester compound as a curing agent, and a resin varnish containing a phosphorus-based compound containing phosphorus; A base material.

Further, the phosphorus compound may include at least one of a phosphorus epoxy compound, a phosphazene compound, a phosphorus phenol compound, and a phosphorus cyanate compound.

Further, the polyphenylene resin composition contains silica, and silica may be contained in an amount of 10 to 100 parts by mass based on 100 parts by mass of the resin composition.

According to the present invention, it is possible to provide a prepreg that does not use halogen-based materials.

<Embodiment 1>
Hereinafter, the prepreg according to the present invention will be explained in detail. However, the prepreg of the present invention is not to be interpreted as being limited to the contents described in the embodiments and examples below.

[Prepreg composition]
The prepreg according to Embodiment 1 of the present invention includes a resin composition containing polyphenylene ether, a crosslinked curing agent, and a phosphorus-based compound containing phosphorus, and a base material.

(Polyphenylene ether)
The polyphenylene ether contained in the resin composition of the present invention is represented by the above general formula (1) and has a number average molecular weight of 1000 to 7000.

In the above general formula (1), X represents an aryl group, (Y) _m represents a polyphenylene ether moiety, and R ¹ to R ³ each represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. In general formula (1), n is an integer of 1 or more and 6 or less, and q is an integer of 1 or more and 4 or less. Here, n is preferably an integer of 1 or more and 4 or less, more preferably n is 1 or 2, and ideally n is 1. Moreover, q is preferably an integer of 1 or more and 3 or less, more preferably 1 or 2, and ideally q is 1.

(aryl group)
As the aryl group in general formula (1), an aromatic hydrocarbon group can be used. Specifically, a phenyl group, a biphenyl group, an indenyl group, and a naphthyl group can be used as the aryl group, and it is preferable to use an aryl group. Here, the aryl group includes a diphenyl ether group in which the above aryl group is bonded through an oxygen atom, a benzophenone group in which the above aryl group is bonded via a carbonyl group, and a 2,2-diphenylpropane group bonded through an alkylene group. But that's fine. The aryl group may also be substituted with a common substituent such as an alkyl group (preferably a C ₁ -C ₆ alkyl group, especially a methyl group), an alkenyl group, an alkynyl group or a halogen atom. However, since the "aryl group" is substituted with a polyphenylene ether moiety via an oxygen atom, the limit on the number of general substituents depends on the number of polyphenylene ether moieties.

(Polyphenylene ether part)
The polyphenylene ether moiety in general formula (1) is represented by the following general formula (2) and consists of phenyloxy repeating units. Here, the phenyl group may be substituted with a common substituent.

In the above general formula (2), R ⁴ to R ⁷ each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group. In general formula (2), m represents an integer of 1 to 100. Here, the value of m is adjusted so that the number average molecular weight of the polyphenylene ether of general formula (1) is 1000 or more and 7000 or less. That is, m may not be a fixed value, but may be a variable within a certain range such that the number average molecular weight of the entire polyphenylene ether contained in the polyphenylene ether resin composition is 1000 or more and 7000 or less.

Here, if the number average molecular weight of polyphenylene ether exceeds 7,000, fluidity during molding will decrease, making multilayer molding difficult. On the other hand, if the number average molecular weight of the polyphenylene ether is less than 1000, there is a possibility that the original excellent dielectric properties and heat resistance of the polyphenylene ether resin cannot be obtained. In order to obtain better fluidity, heat resistance, and dielectric properties, the number average molecular weight of the polyphenylene ether is preferably 1,200 or more and 5,000 or less. More preferably, the number average molecular weight of the polyphenylene ether is 1,500 or more and 4,500 or less.

Furthermore, polyphenylene ether having the above number average molecular weight has very good compatibility when blended with a crosslinked curing agent. In other words, the smaller the number average molecular weight of polyphenylene ether, the higher the compatibility with the mixture. Therefore, viscosity increase due to phase separation is less likely to occur, and volatilization of the crosslinked curing agent having a low molecular weight is suppressed. As a result, the embeddability of the polyphenylene ether resin composition into via holes and the like can be improved.

The alkyl group, alkenyl group, and alkynyl group in general formula (2) can be the same as the alkyl group, alkenyl group, and alkynyl group in general formula (1) described below. As the alkenylcarbonyl group of the polyphenylene ether moiety, a carbonyl group substituted with the above-mentioned alkenyl group can be used. Specifically, an acryloyl group or a methacryloyl group can be used.

Here, the polyphenylene ether moiety in general formula (2) includes substituents R ⁴ to R ⁷ such as vinyl group, 2-propylene group (allyl group), methacryloyl group, acryloyl group, 2-propyne group (propargyl group), etc. It may have an unsaturated hydrocarbon-containing group. By providing the above-mentioned unsaturated hydrocarbon-containing groups to the substituents R ⁴ to R ⁷ of the polyphenylene ether moiety, more significant effects of the crosslinked curing agent can be obtained.

The polyphenylene ether having the above-mentioned group at the end has good interaction with the crosslinked curing agent. Therefore, by simply adding a relatively small amount of crosslinked curing agent, heat resistance can be improved and a lower dielectric constant can be achieved.

(alkyl group)
A saturated hydrocarbon group can be used as the alkyl group in General Formula (1) and General Formula (2). As the alkyl group mentioned above, it is preferable to use a C ₁ -C ₁₀ alkyl group. Preferably, a C ₁ -C ₆ alkyl group is used as the alkyl group. More preferably, a C ₁ -C ₄ alkyl group is used as the alkyl group. More preferably, a C ₁ -C ₂ alkyl group is used as the alkyl group. Specifically, as the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group can be used.

(alkenyl group)
As the alkenyl group in general formula (1) and general formula (2), an unsaturated hydrocarbon group having at least one carbon-carbon double bond in the structure can be used. As the above alkenyl group, a C ₂ -C ₁₀ alkenyl group is preferably used. Preferably, a C ₂ -C ₆ alkenyl group is used as the above alkenyl group. More preferably, a C ₂ -C ₄ alkenyl group is used as the above alkenyl group. Specifically, as the alkenyl group, ethylene group, 1-propylene group, 2-propylene group, isopropylene group, butylene group, isobutylene group, pentylene group, and hexylene group can be used.

(alkynyl group)
As the alkynyl group in general formula (1) and general formula (2), an unsaturated hydrocarbon group having at least one carbon-carbon triple bond in the structure can be used. As the alkynyl group mentioned above, a C ₂ -C ₁₀ alkynyl group is preferably used. Preferably, a C ₂ -C ₆ alkynyl group is used as the alkynyl group. More preferably, a C ₂ -C ₄ alkynyl group is used as the alkynyl group. Specifically, as the alkynyl group, an ethyne group, 1-propyne group, 2-propyne group, isopropyne group, butyne group, isobutyne group, pentyne group, and hexyne group can be used.

(Flame retardants)
The phosphorus-based compound containing phosphorus that is included in the present resin composition and functions as a flame retardant can include at least one of a phosphorus epoxy compound, a phosphazene compound, a phosphorus phenol compound, and a phosphorus cyanate compound. For example, a cyclophosphazene compound can be used as the phosphorus compound. The cyclophosphazene compound may be any compound having a cyclic structure in which phosphorus and nitrogen are alternately bonded by double bonds. Specifically, flame retardancy can be improved by using a cyclophosphazene compound represented by the following general formula (3). For example, as the cyclophosphazene compound, FP-100 (manufactured by Fushimi Pharmaceutical Co., Ltd.), SPS-100, SPB-100, SPE-100 (manufactured by Otsuka Chemical Co., Ltd.), etc. can be used.

The content ratio of the above-mentioned phosphorus compound is preferably 10% by mass or more and 25% by mass or less based on the total amount of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. Further, from the viewpoint of heat resistance, flame retardance, and electrical properties, the content is preferably 15% by mass or more and 20% by mass or less.

(Crosslinked curing agent)
As the crosslinking type curing agent contained in the present resin composition, a curing agent that three-dimensionally crosslinks polyphenylene ether can be used. Specifically, a polyfunctional vinyl compound, a vinylbenzyl ether compound, an allyl ether compound, or a trialkenyl isocyanurate can be used as the crosslinked curing agent. Polyfunctional vinyl compounds include divinylbenzene, divinylnaphthalene, and divinylbiphenyl. Vinylbenzyl ether compounds are synthesized by the reaction of phenol and vinylbenzyl chloride. Allyl ether compounds are synthesized by the reaction of styrene monomer, phenol, and allyl chloride. Trialkenyl isocyanurate has good compatibility, and triallyl isocyanurate (hereinafter referred to as TAIC) or triallyl cyanurate (hereinafter referred to as TAC) can be used.

In addition to the above-mentioned materials, (meth)acrylate compounds (methacrylate compounds and acrylate compounds) can be used as the crosslinked curing agent. In particular, it is preferable to contain a (meth)acrylate compound having a functionality of 3 or more and 5 or less in an amount of 3% by mass or more and 20% by mass or less based on the total amount of the resin composition. As the methacrylate compound with a functionality of 3 or more and 5 or less, trimethylolpropane trimethacrylate (TMPT) etc. can be used, and on the other hand, as the acrylate compound with a functionality of 3 or more and 5 or less, trimethylolpropane triacrylate etc. can be used. Can be done. By using the above crosslinked curing agent, the heat resistance of the resin composition can be further improved.

If the functionality of the (meth)acrylate compound is less than 3 or more than 5, the heat resistance will be lower than that of a (meth)acrylate compound with a functionality of 3 or more and 5 or less. In addition, even if the (meth)acrylate compound has a functionality of 3 or more and 5 or less, if the content is less than 3% by mass based on the total amount of the resin composition, the effect of improving the heat resistance of the resin composition will be insufficient. can't get to it. On the other hand, if it exceeds 20% by mass, dielectric properties and moisture resistance will deteriorate.

The content ratio of polyphenylene ether and crosslinked curing agent in the present resin composition is preferably 30/70 or more and 90/10 or less. Preferably, the above content ratio is 50/50 or more and 90/10 or less. More preferably, the above content ratio is 60/40 or more and 90/10 or less.

Here, if the content ratio of polyphenylene ether is smaller than the lower limit, the rigidity of the entire resin composition will decrease. Due to this influence, it becomes difficult to make the entire resin composition multilayered. On the other hand, if the content ratio of polyphenylene ether is larger than the upper limit, the heat resistance of the entire resin composition will decrease. By adjusting the content ratio of polyphenylene ether and crosslinked curing agent within the above range, good fluidity and compatibility of the resin composition can be obtained. Therefore, the embeddability of the resin composition into via holes and the like can be improved.

(Base material)
For example, glass cloth can be used as the base material included in the prepreg of the present invention. Moreover, an organic base material can also be used as a base material.

(Other additives)
The resin composition of the present invention may contain one or more additives selected from unmodified polyphenylene ether, an inorganic or organic filler, and a reaction initiator, if necessary. Further, general additive components of resin compositions used for manufacturing electronic devices such as printed wiring boards may be added.

(Unmodified polyphenylene ether)
In addition to the polyphenylene ether described above, the resin composition of the present invention may contain an unmodified polyphenylene ether having a number average molecular weight of 9,000 or more and 18,000 or less. By adding unmodified polyphenylene ether, it is possible to control the fluidity and improve the heat resistance of the resin composition. Further, precipitation of additive components such as fillers in the resin composition can be suppressed. Here, unmodified polyphenylene ether refers to polyphenylene ether that does not have a carbon-carbon unsaturated group in its molecule, and the amount added is 100 parts by mass of the total mass of polyphenylene ether and crosslinked curing agent. It is preferably 3 parts by mass or more and 70 parts by mass or less.

Furthermore, in order to improve heat resistance, adhesion, and dimensional stability, styrene-butadiene block copolymers, styrene-isoprene block copolymers, 1,2-polybutadiene, 1,4-polybutadiene, maleic acid-modified polybutadiene, acrylic acid-modified polybutadiene , and epoxy-modified polybutadiene can be used.

(filling material)
By adding an inorganic filler (hereinafter referred to as an inorganic filler) to the present resin composition, it is possible to reduce the coefficient of thermal expansion and improve the rigidity of a prepreg using the present resin composition. As the inorganic filler, metal oxides, nitrides, silicides, borides, etc., such as silica, boron nitride, wollastonite, talc, kaolin, clay, mica, alumina, zirconia, and titania, can be used. In particular, by adding a low dielectric constant filler such as silica or boron nitride, the dielectric constant of the resin composition can be lowered.

By adding an organic filler (hereinafter referred to as an organic filler) to the present resin composition, the dielectric constant of a prepreg using the present resin composition can be reduced. As the organic filler, fluorine-based, polystyrene-based, divinylbenzene-based, polyimide-based, etc. can be used. Examples of fluorine-based fillers (fluorine-containing compound fillers) include polytetrafluoroethylene (PTFE), polyperfluoroalkoxy resin, polyfluorinated ethylene propylene resin, polytetrafluoroethylene-polyethylene copolymer, polyvinylidene fluoride, and polyethylene fluoride. A chlorotrifluoroethylene resin or the like can be used. These can be used alone or in combination.

Furthermore, hollow polymer fine particles can be used as the organic filler. In particular, by using a hollow body whose shell is made of a low dielectric constant material such as divinylbenzene or divinylbiphenyl, it is possible to achieve a low dielectric constant of the prepreg.

As the inorganic filler or organic filler, fine particles having an average particle size of 10 μm or less can be used. The average particle size here may be a value described in materials such as a catalog of fillers to be added, or may be an average value or a median value of a plurality of randomly extracted fillers. By setting the average particle size of the filler to the above conditions, a prepreg with high smoothness and reliability can be obtained.

(Reaction initiator)
By adding a reaction initiator to the present resin composition, more significant effects of the crosslinked curing agent can be obtained. As the reaction initiator, general materials can be used as long as they can improve properties such as heat resistance of the resin composition by promoting curing of the resin composition at an appropriate temperature and time. Specifically, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, benzoyl peroxide , 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, azobisisobutyronitrile Oxidizing agents such as the following can be used. Here, a carboxylic acid metal salt or the like may be added as necessary to further accelerate the curing reaction.

As described above, according to the prepreg according to Embodiment 1 of the present invention, by using a phosphorus-based compound as a flame retardant, halogen-based materials can be used while suppressing increases in Dk and Df without deteriorating flame retardancy. Not able to provide prepreg.

[Method for manufacturing printed wiring board (laminate)]
Here, a method for producing a laminate using the prepreg produced as described above will be described. First, one or more prepregs are stacked, metal foils such as copper foils are stacked on both or one side of the top and bottom, and the laminate is heated and press-molded. By this molding, a laminate having metal foil on both sides or one side can be produced. A printed wiring board can be obtained by patterning and etching the metal foil of this laminate to form a circuit. In addition, a multilayer printed wiring board can be produced by stacking a plurality of prepregs with a metal foil on which a circuit is formed between them and molding them under heat and pressure.

The heating and pressure molding conditions vary depending on the content ratio of raw materials of the resin composition according to the present invention, but are generally 170°C or higher and 230°C or lower, and a pressure of 1.0 MPa or higher and 6.0 MPa or lower (10 kg/cm 2 or higher and 60 kg/cm ² or higher). /cm ² or less) for an appropriate period of time.

The metal foil used for the above laminate should have a surface roughness (ten point average roughness: Rz) of 2 μm or less, and a surface on which the resin layer is formed by the prepreg (a surface in contact with the prepreg). ) may be treated with zinc or zinc alloy to prevent rust and improve adhesion with the resin layer, and further subjected to coupling treatment with a vinyl group-containing silane coupling agent or the like. Such copper foil has good adhesion to the resin layer (insulating layer), and a printed wiring board with excellent high frequency characteristics can be obtained. In addition, when treating copper foil with zinc or a zinc alloy, zinc or a zinc alloy can be formed on the surface of the copper foil by a plating method.

The laminate and printed wiring board thus obtained can achieve low Dk and low Df without deteriorating flame retardancy, even without using halogen-based materials. Further, a laminate or printed wiring board having high moldability, water resistance, moisture resistance, moisture absorption heat resistance, and glass transition temperature can be obtained.

<Embodiment 2>
Hereinafter, the prepreg according to the present invention will be explained in detail. However, the prepreg of the present invention is not to be interpreted as being limited to the contents described in the embodiments and examples below.

[Prepreg composition]
The prepreg according to Embodiment 2 of the present invention includes a resin composition consisting of a resin varnish having an epoxy compound, polyphenylene ether, a cyanate ester compound, a curing catalyst, and a phosphorus-based compound containing phosphorus, and a base material. . Here, the epoxy compound has a number average molecular weight of 1000 or less and does not contain a halogen atom having at least two epoxy groups in one molecule. Moreover, the number average molecular weight of polyphenylene ether is 5,000 or less. Further, the curing catalyst promotes the reaction between the epoxy compound and polyphenylene ether and the cyanate ester compound that is the curing agent.

(epoxy compound)
As the epoxy compound, a dicyclopentadiene type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a phenol novolac type epoxy compound, a naphthalene type epoxy compound, a biphenyl type epoxy compound, etc. can be used. These can be used alone or in combination. Among the above, dicyclopentadiene type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, and biphenyl type epoxy compounds are particularly preferred because they have good compatibility with polyphenylene ether.

The content of the epoxy compound in the prepreg of the present embodiment is preferably 20% by mass or more and 60% by mass or less based on the total amount of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. More preferably, the content of the epoxy compound is 30% by mass or more and 50% by mass or less. By setting the content of the epoxy compound within the above range, sufficient heat resistance and excellent mechanical and electrical properties can be maintained.

(Polyphenylene ether)
The polyphenylene ether has a number average molecular weight of 5,000 or less, preferably 2,000 or more and 4,000 or less.

When the number average molecular weight of polyphenylene ether exceeds 5,000, fluidity deteriorates and reactivity with epoxy groups also decreases. Therefore, the curing reaction takes a long time, and the amount of unreacted materials that are not incorporated into the curing system increases, lowering the glass transition temperature and making it impossible to obtain a sufficient improvement in heat resistance.

The content ratio of polyphenylene ether in the prepreg of this embodiment is preferably 20% by mass or more and 60% by mass or less based on the total amount of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. More preferably, the content of polyphenylene ether is 20% by mass or more and 40% by mass or less. When the content of polyphenylene ether is within the above range, excellent dielectric properties can be obtained.

(Flame retardants)
As the flame retardant, a phosphorus-based compound containing phosphorus can be used. Specifically, the phosphorus-based compound can include at least one of an epoxy compound, a phosphazene compound, a phosphophenol compound, and a phosphocyanate compound. For example, a cyclophosphazene compound can be used as the phosphorus compound. As the cyclophosphazene compound, a compound having a cyclic structure in which phosphorus and nitrogen are alternately bonded by double bonds can be used. In particular, flame retardancy can be improved by using the cyclophosphazene compound represented by the above general formula (3). For example, the above-mentioned FP-100, SPS-100, SPB-100, SPE-100, etc. can be used as the cyclophosphazene compound.

(Cyanate ester compound)
As the cyanate ester compound, a compound having two or more cyanate groups in one molecule can be used. Specifically, 2,2-bis(4-cyanatophenyl)propane, bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)ethane, etc. Alternatively, aromatic cyanate ester compounds such as derivatives thereof can be used. These can be used alone or in combination.

The cyanate ester compound is a component that acts as a curing agent for the epoxy compound to form the epoxy resin and forms a rigid skeleton. Therefore, a high glass transition point (Tg) can be obtained. Moreover, since the viscosity is low, the resulting resin varnish can maintain high fluidity.

The content ratio of the cyanate ester compound in the prepreg of the present embodiment is preferably 20% by mass or more and 60% by mass or less based on the total amount of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. More preferably, the content of the cyanate ester compound is 20% by mass or more and 40% by mass or less. When the content ratio of the cyanate ester compound is within the above range, sufficient heat resistance can be obtained, excellent impregnating properties to the base material, and crystal precipitation can be prevented even in the resin varnish.

(curing catalyst)
As curing catalysts, organic metal salts such as Zn, Cu, and Fe of organic acids such as octanoic acid, stearic acid, acetylacetonate, naphthenic acid, and salicylic acid, tertiary amines such as triethylamine and triethanolamine, and 2-ethyl- Imidazoles such as 4-imidazole and 4-methylimidazole can be used. These can be used alone or in combination. Among the above, organic metal salts, particularly zinc octoate, are preferable because higher heat resistance can be obtained.

For example, in the case of using an organic metal salt, the content ratio of the curing catalyst in the prepreg of this embodiment is 0.005 with respect to the total amount (100 parts by mass) of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. The amount can be set to 5 parts by mass or more and 5 parts by mass or less. For example, when imidazoles are used, the content of the curing catalyst is 0.01 parts by mass or more and 5 parts by mass based on the total amount (100 parts by mass) of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. It can be as follows.

(Base material)
For example, glass cloth can be used as the base material included in the prepreg of the present invention. Moreover, an organic base material can also be used as a base material.

(filling material)
An inorganic filler can be added to the resin composition of the present invention, if necessary. The inorganic filler can improve dimensional stability during heating and flame retardancy. As the inorganic filler, specifically, silica such as spherical silica, alumina, talc, aluminum hydroxide, magnesium hydroxide, titanium oxide, mica, aluminum borate, barium sulfate, calcium carbonate, etc. can be used. Furthermore, as the inorganic filler, one whose surface has been treated with an epoxysilane type or aminosilane type silane coupling agent can be used. By containing an inorganic filler whose surface has been treated with a silane coupling agent, it is possible to improve the heat resistance during moisture absorption and the adhesion between layers.

The content ratio of the inorganic filler in the prepreg of this embodiment is set to be 10 parts by mass or more and 100 parts by mass or less with respect to the total amount (100 parts by mass) of the components of the epoxy compound, polyphenylene ether, and cyanate ester compound. It is advisable to contain it in a suitable proportion. Preferably, the content of the inorganic filler is 20 parts by mass or more and 70 parts by mass or less. More preferably, the content of the inorganic filler is 20 parts by mass or more and 50 parts by mass or less. By setting the content of the inorganic filler within the above range, dimensional stability can be improved without reducing fluidity or adhesion to metal foil.

In addition to the above-mentioned inorganic fillers, the resin composition of the present invention may contain general additive components of resin compositions used for manufacturing electronic devices such as printed wiring boards. For example, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes, pigments, lubricants, etc. may be added.

[Prepreg manufacturing method]
In the present resin composition of the prepreg according to Embodiment 2 of the present invention, the components of the epoxy compound, polyphenylene ether, phosphorus compound, and cyanate ester compound are all dissolved in the resin varnish, and the inorganic filler The components are not dissolved but dispersed in the resin varnish. Such a resin varnish is prepared, for example, as follows.

First, predetermined amounts of an epoxy compound and a cyanate ester compound are dissolved in a resin solution of polyphenylene ether. This dissolution may be performed at room temperature or may be performed while heating. By using a material that dissolves in a solvent such as toluene at room temperature as the epoxy compound and cyanate ester compound, it is possible to suppress the formation of precipitates in the resin varnish.

When adding an inorganic filler as an additive, the resin varnish is prepared by adding the filler and then dispersing it using a ball mill, bead mill, planetary mixer, roll mill, etc. until a predetermined dispersion state is achieved. be done.

A prepreg can be obtained by impregnating a base material with the resin varnish obtained as described above using the same manufacturing method as in Embodiment 1 and drying it. Further, a printed wiring board (laminate) can be obtained using the same manufacturing method as in the first embodiment.

Below, prepregs according to Embodiments 1 and 2 of the present invention were produced, and the characteristic values of dielectric constant (Dk) and dielectric loss tangent (Df), as well as the results of evaluating flame retardance, will be specifically described. Example 1 shown below corresponds to the example of Embodiment 1, and Example 3 and Example 4 correspond to the examples of Embodiment 2.

First, the polyphenylene ether used in Example 1 and Comparative Examples 1 and 3 will be explained.

(Polyphenylene ether (1))
3.88 g (17.4 mmol) of CuBr ₂ and 0.75 g (4.0 mmol) of N,N'-di-t-butylethylenediamine were placed in a 12-liter vertical reactor equipped with a stirring device, thermometer, air inlet tube, and baffle plate. 4 mmol), n-butyldimethylamine 28.04 g (277.6 mmol), and toluene 2600 g were stirred at a reaction temperature of 40°C. 5,5'-hexamethyl-(1,1'-biphenol)-4,4'-diol 129.3 g (0.48 mol), 2,6-dimethylphenol 233.7 g (1.92 mol), 2,3, A mixed solution of 64.9 g (0.48 mol) of 6-trimethylphenol, 0.51 g (2.9 mmol) of N,N'-di-t-butylethylenediamine, and 10.90 g (108.0 mmol) of n-butyldimethylamine was added. A mixed gas prepared by mixing nitrogen and air to have an oxygen concentration of 8% was added dropwise over 230 minutes while bubbling at a flow rate of 5.2 liters/min, followed by stirring.

After the dropwise addition was completed, 1500 g of water in which 19.89 g (52.3 mmol) of tetrasodium ethylenediaminetetraacetate was dissolved was added to stop the reaction. The aqueous layer and the organic layer were separated, and the organic layer was washed with a 1N aqueous hydrochloric acid solution and then with pure water. The obtained solution was concentrated to 50 wt% using an evaporator to obtain 836.5 g of a toluene solution of a bifunctional phenylene ether oligomer (resin "A"). Resin "A" had a number average molecular weight of 986, a weight average molecular weight of 1,530, and a hydroxyl equivalent of 471.

In a reactor equipped with a stirring device, a thermometer, and a reflux tube, 836.5 g of a toluene solution of resin "A", 162.6 g of vinylbenzyl chloride (trade name: CMS-P; manufactured by Seimi Chemical Co., Ltd.), 1600 g of methylene chloride, 12.95 g of benzyldimethylamine, 420 g of pure water, and 178.0 g of 30.5 wt% NaOH aqueous solution were charged and stirred at a reaction temperature of 40°C. After stirring for 24 hours, the organic layer was washed with a 1N aqueous hydrochloric acid solution and then with pure water. The obtained solution was concentrated using an evaporator, solidified by dropping it into methanol, and the solid was collected by filtration and vacuum dried to obtain 503.5 g of "polyphenylene ether (1)". "Polyphenylene ether (1)" had a number average molecular weight of 1187, a weight average molecular weight of 1675, and a vinyl group equivalent of 590 g/vinyl group.

(Polyphenylene ether (2))
9.36 g (42.1 mmol) of CuBr ₂ and 1.81 g (10.1 mmol) of N,N'-di-t-butylethylenediamine were placed in a 12-liter vertical reactor equipped with a stirring device, thermometer, air inlet tube, and baffle plate. 5 mmol), n-butyldimethylamine 67.77 g (671.0 mmol), and toluene 2600 g were stirred at a reaction temperature of 40°C. 5,5'-hexamethyl-(1,1'-biphenol)-4,4'-diol 129.32g (0.48mol), 2,6-dimethylphenol 878.4g (7.2mol), N,N' - A mixed solution of 1.22 g (7.2 mmol) of di-t-butylethylenediamine and 26.35 g (260.9 mmol) of n-butyldimethylamine was mixed with nitrogen and air to adjust the oxygen concentration to 8%. Gas was added dropwise over 230 minutes while bubbling at a flow rate of 5.2 liters/min, followed by stirring.

After the dropwise addition was completed, 1500 g of water in which 48.06 g (126.4 mmol) of tetrasodium ethylenediaminetetraacetate was dissolved was added to stop the reaction. The aqueous layer and the organic layer were separated, and the organic layer was washed with a 1N aqueous hydrochloric acid solution and then with pure water. The obtained solution was concentrated to 50 wt % using an evaporator to obtain 1981 g of a toluene solution of a bifunctional phenylene ether oligomer (resin "B"). Resin "B" had a number average molecular weight of 1975, a weight average molecular weight of 3514, and a hydroxyl equivalent of 990.

In a reactor equipped with a stirring device, a thermometer, and a reflux tube, 833.4 g of a toluene solution of resin "B", 76.7 g of vinylbenzyl chloride (trade name CMS-P; manufactured by Seimi Chemical Co., Ltd.), 1600 g of methylene chloride, 6.2 g of benzyldimethylamine, 199.5 g of pure water, and 83.6 g of 30.5 wt% NaOH aqueous solution were charged, and stirring was performed at a reaction temperature of 40°C. After stirring for 24 hours, the organic layer was washed with a 1N aqueous hydrochloric acid solution and then with pure water. The obtained solution was concentrated using an evaporator, solidified by dropping it into methanol, and the solid was collected by filtration and dried under vacuum to obtain 450.1 g of "polyphenylene ether (2)". The vinyl "polyphenylene ether (2)" had a number average molecular weight of 2250, a weight average molecular weight of 3920, and a vinyl group equivalent of 1189 g/vinyl group.

Next, a method for manufacturing prepregs of Example 1 , Comparative Examples 1 and 3, and evaluation samples for dielectric constant, dielectric loss tangent, and flame retardancy will be described.

[Example 1]
70 parts by mass of the above polyphenylene ether (1) was prepared, 100 parts by mass of toluene was added as a solvent, and the mixture was mixed and stirred at 80° C. for 30 minutes to completely dissolve. To the polyphenylene ether solution thus obtained, 30 parts by mass of "TAIC" manufactured by Nippon Kasei Co., Ltd. was added as a cross-linked curing agent, and a cyclophosphazene compound (manufactured by Fushimi Pharmaceutical Co., Ltd.) was added as a phosphorus compound as a flame retardant. 20 parts by mass of "FP-100 (trade name)" manufactured by Co., Ltd., and 14 parts by mass of spherical synthetic silica ("SC2050 (trade name)" manufactured by Admatex Co., Ltd.) as an inorganic filler were blended. These were diluted with methyl ethyl ketone to a solid content of 65% to obtain a varnish.

Next, the base material E glass cloth (IPC No. #3313) was impregnated with the above varnish, and then heated and dried at a temperature of 170°C for 5 minutes to remove the solvent and reduce the resin content to 55% by mass. % prepreg was obtained. The thickness of the E glass cloth used as the base material was 80 μm. Eight sheets of prepreg thus obtained were stacked, and copper foil (3EC-III, manufactured by Mitsui Mining and Mining Co., Ltd.) having a thickness of 18 μm was stacked on both the top and bottom sides. Vacuum pressing was performed at a temperature of 210° C., a pressure of 3.0 MPa (30 kg/cm ² ), and a molding time of 150 minutes to obtain a double-sided copper-clad laminate for a printed wiring board with a thickness of 0.8 mm. Using the obtained copper-clad laminate, dielectric properties and flame retardance were evaluated.

(Measurement method and evaluation method)
1) Flame resistance: Test by cutting a double-sided copper foil-covered laminate with a thickness of about 0.8 mm into a size of 13 mm x 130 mm x about 0.8 mm thick using a dicing saw, and then removing all the copper foil on both sides by etching. Got a piece. Using this test piece, a flame resistance test was conducted according to the UL94 vertical test method (the number of evaluation samples was 5 (n=5)).
2) Dielectric constant/dielectric loss tangent: Using a test piece from which the copper foil of a copper-clad laminate with a thickness of 0.8 mm has been removed, the dielectric constant of 10 GHz was determined by the cavity resonator perturbation method (Agilent 8722ES, manufactured by Agilent Technologies). The dielectric loss tangent was measured.

[ Comparative example 3 ]
In Comparative Example 3 , a varnish was produced using polyphenylene ether (2) instead of polyphenylene ether (1) used in Example 1. The varnish of Comparative Example 3 was produced in the same manner as in Example 1.

[Comparative example 1]
In Comparative Example 1, which is a comparative example of Example 1, a conventional halogen compound, ethylene bis(pentabromophenyl) (manufactured by Albemarle Japan Co., Ltd.) was used instead of the phosphorus compound as the flame retardant in Example 1. SAYTEX 8010 (trade name)" was used.

Table 1 shows the configurations and evaluation results of Example 1 , Comparative Examples 1 and 3 .

As shown in Table 1, compared to Comparative Example 1 in which a halogen-based compound was used as a flame retardant, Example 1 and Comparative Example 3 in which a phosphorus-based compound was used as a flame retardant met the UL standards as in Comparative Example 1. It was confirmed that V-0 was satisfied and lower Dk and Df values than Comparative Example 1 could be obtained.

Next, the polyphenylene ether and epoxy compound used in Example 3, Example 4, and Comparative Example 2 will be explained.

(Polyphenylene ether (3))
As "polyphenylene ether (3)", polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics) in which the terminal end of polyphenylene ether is a hydroxyl group was used. The number average molecular weight of "polyphenylene ether (3)" is 1,700.

(Epoxy compound (1))
As the epoxy compound, a dicyclopentadiene type epoxy compound ("Epiclon HP7200 (trade name)" manufactured by DIC) was used. The number average molecular weight of Epiclon HP7200 is 550.

(Epoxy compound (2))
As the epoxy compound, a naphthalene skeleton-modified epoxy resin ("Epiclon HP4032D (trade name)" manufactured by DIC) was used. The number average molecular weight of Epiclon HP4032D is 280.

Next, a method for manufacturing prepregs of Examples 3 and 4 and Comparative Example 2 and evaluation samples for dielectric constant, dielectric loss tangent, and flame retardancy will be described.

[Example 3]
30 parts by mass of the above polyphenylene ether (3) was prepared, toluene was added as a solvent, and the mixture was mixed and stirred to completely dissolve. To the polyphenylene ether solution thus obtained, 45 parts by mass of the above epoxy compound (1) and 2,2-bis(4-cyanatophenyl)propane (Mitsubishi Gas Chemical After adding 25 parts by mass of "CA210 (trade name)" manufactured by Co., Ltd., the mixture was stirred for 30 minutes to completely dissolve. Furthermore, 20 parts by mass of the above-mentioned "FP-100") as a phosphorus compound as a flame retardant, 25 parts by mass of the above-mentioned "SC2050" as an inorganic filler, and zinc octoate (manufactured by Nikka Co., Ltd.) as a curing catalyst. 0.01 part by weight was mixed and diluted with methyl ethyl ketone to a solid content of 65% to obtain a varnish.

Next, the above varnish was applied to the base material E glass cloth (IPC No. #3313), and then heated and dried at a temperature of 170°C for 5 minutes to obtain a prepreg with a resin content of 55% by mass. Ta. The thickness of the E glass cloth used as the base material was 80 μm. Eight sheets of prepreg thus obtained were stacked, and copper foil (3EC-III, manufactured by Mitsui Mining and Mining Co., Ltd.) having a thickness of 18 μm was stacked on both the top and bottom sides. Vacuum pressing was performed at a temperature of 210° C., a pressure of 3.0 MPa (30 kg/cm ² ), and a molding time of 150 minutes to obtain a double-sided copper-clad laminate for a printed wiring board. Next, dielectric properties and flame retardance were evaluated using a test piece from which the copper foil of the copper-clad laminate having a thickness of 0.8 mm had been removed.

[Example 4]
In Example 4, a varnish was produced using epoxy compound (2) instead of epoxy compound (1) used in Example 3. The varnish of Example 4 was produced in the same manner as in Example 3.

[Comparative example 2]
As a comparative example of the above Examples 3 and 4, in Comparative Example 2, the above-mentioned "SAYTEX 8010" which is a conventional halogen compound was used instead of the phosphorus compound as the flame retardant of Example 3.

Table 2 shows the configurations and evaluation results of Example 3, Example 4, and Comparative Example 2.

As shown in Table 2, compared to Comparative Example 2 in which a halogen compound was used as a flame retardant, Examples 3 and 4 in which a phosphorus compound was used as a flame retardant met the UL standards as in Comparative Example 2. It was confirmed that V-0 was satisfied and Dk and Df values equivalent to those of Comparative Example 2 could be obtained.

As described above, according to the prepregs according to Examples 1 , 3, and 4 of the present invention, by using a phosphorus compound as a flame retardant, increases in Dk and Df can be suppressed without deteriorating flame retardancy. At the same time, it is possible to provide a prepreg that does not use halogen-based materials.

Note that the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit.

Claims (4)

A polyphenylene ether resin composition containing polyphenylene ether, a crosslinked curing agent, and a phosphorus-based compound containing phosphorus;
a base material;
The polyphenylene ether has the general formula (1)

is represented by, and has a number average molecular weight of 1187 ,
In the ^general formula ( ¹ ₎ ^, A prepreg characterized in that n represents an integer of 1 to 6, and q represents an integer of 1 to 4. The prepreg according to claim 1, wherein the polyphenylene ether resin composition contains unmodified polyphenylene ether having a number average molecular weight of 9,000 or more and 18,000 or less. The prepreg according to claim 1 or 2, wherein the phosphorus-based compound contains at least one of a phosphorus epoxy compound, a phosphazene compound, a phosphorus phenol compound, and a phosphorus cyanate compound. The prepreg according to claim 3, wherein the polyphenylene ether resin composition contains silica, and the silica is contained in an amount of 10 to 100 parts by mass based on 100 parts by mass of the resin composition.