JP2563137B2 - Flame-retardant polyphenylene oxide resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant polyphenylene oxide resin composition and a laminate using the same.

More specifically, the present invention relates to a flame-retardant polyphenylene oxide-based resin composition which is useful as a wiring board used in electric equipment, electronic equipment, and the like, and which is excellent in heat resistance and electric insulation as well as flame retardancy and the use thereof. The present invention relates to a metal-clad laminate.

(Prior Art) With regard to wiring boards used in precision equipment, electronic computers, communication equipment, etc., there are increasing demands for high-speed arithmetic processing, high reliability, high circuit density, and miniaturization. In order to cope with this, wiring boards are being multi-layered and highly precise miniaturization is rapidly progressing.

Heretofore, in such wiring boards, epoxy resins, polyimide resins, and fluororesins or polybutadiene resins as low dielectric constant resins have been used as the resins constituting the wiring boards. Is being promoted.

For example, as the density of wirings increases, it becomes an indispensable condition for resins used for multilayer wiring boards to be flame-retardant. However, conventional resins are generally flammable. Therefore, a flame retardant is usually added to the resin used for the wiring board in order to make it flame-retardant efficiently and surely.

However, even if the resin itself has a low dielectric constant,
Adding a flame retardant increases the resin dielectric constant,
It is not possible to cope with the high-speed signal processing required by measuring instruments and computer-related equipment.

As a solution to such a problem, a new resin for a laminated board that has a low dielectric constant, can be stably used for high-speed signal processing, is excellent in flame retardancy, and can achieve multi-layer densification of wiring A flame-retardant resin composition of the polyphenylene oxide type has also been provided as a composition.

(Problems to be Solved by the Invention) However, this polyphenylene oxide-based resin composition has excellent resin properties and is expected as a laminated resin for printed wiring boards. Although it imparts flame retardancy, it has a drawback that it is difficult to improve heat resistance and electrical insulation.

This defect is attributed to the fact that many flame retardants having high flame retardancy are solid, and the solid flame retardant does not have very good adhesion to the polyphenylene oxide resin.

Therefore, as a measure for improving the adhesion, a known means of adding a solid flame retardant which has been surface-treated in advance when the flame retardant is mixed (for example, JP-A-60-
32837 and JP-A-60-84337) are considered.

However, in practice, even if such a means is applied, good heat resistance cannot always be obtained in the case of the polyphenylene oxide resin composition.

The compatibility with the composition of the polyphenylene oxide resin is a problem.

The present invention has been made in order to solve the above-mentioned drawbacks of the conventional flame-retardant polyphenylene oxide-based resin composition, and has a low dielectric constant, good flame resistance and good heat resistance and electrical insulation. It is an object of the present invention to provide a new flame-retardant resin composition capable of imparting properties.

(Means for Solving the Problems) As a solution to the above problems, the present invention, together with polyphenylene oxide, a crosslinkable polymer and / or a monomer and a reaction initiator, together with a brominated diphenyl ether-based or brominated polycarbonate-based , A flame retardant for an electric laminate, comprising one or more solid flame retardants selected from brominated bisphenol flame retardants and brominated cyanuric acid flame retardants, and a silane coupling agent. Provided is a polyphenylene oxide resin composition.

The polyphenylene oxide used in the flame-retardant polyphenylene oxide-based resin composition of the present invention is a resin having a relatively high glass transition point, a low dielectric constant, and a low dielectric loss, and has recently been noted because it is inexpensive. is there. However, until now, its flame retardancy could not be improved, so that it has not been put to practical use as a resin for a high-density wiring board.

However, the inventors of the present invention have found that by adding a flame retardant or a flame retardant and a flame retardant auxiliary to a polyphenylene oxide resin composition, the flame retardancy can be improved while maintaining its low dielectric property. It was In order to make the polyphenylene oxide resin composition contain a flame retardant to make it flame-retardant and to improve heat resistance and electric insulation, 1) the resin composition contains a cross-linking agent polymer and And / or monomer blending is essential, 2) brominated diphenyl ether type solid flame retardant,
It is necessary to use at least one solid flame retardant selected from brominated polycarbonate flame retardants, brominated bisphenol flame retardants, and brominated isocyanuric acid flame retardants. 3) The solid flame retardant is surface-treated in advance. Polyphenylene oxide, crosslinkable polymer and / or monomer, without silane coupling agent,
Then, they found that it was necessary to add and mix with the reaction initiator.

 The present invention is based on the above findings.

The polyphenylene oxide used in the present invention has, for example, the following general formula (1): [R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms,
Each R may be the same or different. ], And one example is poly (2,6
-Dimethyl-1,4-phenylene oxide).

Although the molecular weight is not particularly limited, for example, the weight average molecular weight (Mw) is 50,000, the molecular weight distribution Mw / Mn
= 4.2 (Mn is number average molecular weight).

Such polyphenylene oxide is, for example, the above poly (2,6-dimethyl-1,4-phenylene oxide).
Can be obtained by subjecting 2,6-quinnol to an oxidative coupling reaction with a gas containing oxygen and methanol in the presence of a catalyst. Here, the catalyst includes a symbol of copper (I), N, N'-di-tert-butylethylenediamine, butyldimethylamine and hydrogen bromide. Further, methanol is used by adding 2 to 15% by weight of water to the reaction mixture system based on this so that the total of methanol and water becomes a polymerization solvent of 5 to 25% by weight.

Examples of the crosslinkable polymer include 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (mylene-modified, acryl-modified, epoxy-modified) rubbers, polytriallyl isocyanurate, poly Examples thereof include triallyl cyanurate, and each of them can be used alone or in combination of two or more kinds. The state of these polymers may be elastomer or rubber.

However, when the laminated plate of the present invention is produced using a film formed by the casting method described below,
From the viewpoint of improving the film forming property of the film, it is preferable to use polystyrene having a relatively high molecular weight.

The polymer of polytriallyl isocyanurate or polyallyl cyanurate can be synthesized by a method of solution polymerization or bulk polymerization.

In the case of the solution polymerization, the reaction is milder than the bulk polymerization method and the molecular weight can be easily adjusted. It can be carried out by a method in which a triallyl isocyanurate monomer or a triallyl cyanurate monomer is dissolved in a solvent, a radical initiator is mixed and reacted with stirring until an appropriate molecular weight is obtained, and heating is carried out if necessary. At that time, it is preferable to carry out the reaction using a reflux apparatus and in an atmosphere in which oxygen does not exist.

The reaction atmosphere may be a nitrogen circulation atmosphere. Further, as the solvent, benzene, toluene, xylene, methanol, ethanol, acetone, methyl ethyl ketone, heptane, carbon tetrachloride, dichloromethane, trichloroethylene, etc. can be used.

As the radical initiator, any conventionally known one may be used, and examples thereof include benzoyl peroxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane and t-butyl. Examples thereof include peroxybenzoate and dicumyl peroxide.

For example, a triallyl isocyanurate prepolymer can be synthesized as follows.

(Example 1) 11 g of benzoyl peroxide and 1087 g of benzene were added to 280 g of triallyl isocyanurate monomer, and the mixture was reacted for 6 hours while boiling under a nitrogen atmosphere using a stirrer and a reactor equipped with a reflux condenser. After collecting benzene under reduced pressure, methanol is added to collect the polymer, and the polymer is dried under reduced pressure. 139g
To obtain a polymer. The number average molecular weight is about 10,000.

(Example 2) To 225 g of triallyl isocyanurate, 10 g of dicumyl peroxide and 527 g of toluene were added, and a prepolymer was obtained in the same manner as in Example 1. The number average molecular weight is about 4,000.

For example, the number average molecular weight of the triallyl isocyanurate or triallyl cyanurate prepolymer that can be synthesized as described above is preferably 10,000 or less.

Examples of the crosslinkable monomer include acrylates such as ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates, and silicon acrylates, triallyl cyanurate, and triallyl isocyanate. Examples include polyfunctional monomers such as nurate, ethylene glycol dimethacrylate, divinylbenzene, and diallyl phthalate, monofunctional monomers such as vinyltoluene, ethylvinylbenzene, styrene, and paramethylstyrene, and polyfunctional epoxies. Two or more kinds can be used in combination. Of these, triallyl cyanurate and / or triallyl isocyanurate are preferable because they have good compatibility with polyphenylene oxide and improve film-forming properties, cross-linking properties, heat resistance, and dielectric properties.

This triallyl cyanurate and triallyl isocyanurate have an isomer relationship in terms of chemical structure and have almost the same film-forming property, compatibility, solubility, reactivity, etc., so either one or Both can be used as well.

Either one of the above-mentioned crosslinkable polymer and crosslinkable monomer may be used, or both may be used in combination, but the combined use is more effective in improving the characteristics.

As the flame retardant used in the present invention, usually, the relative dielectric constant of the polyphenylene oxide resin composition after adding the flame retardant together with the flame retardant auxiliary can be 4.0 or less, and its flame retardancy is UL94 flame retardant. It is preferable to use one that can be V-1 or V-0 as a characteristic based on the test method.

For example, a brominated diphenyl ether system having the following formula (2) (Wherein R represents hydrogen, an aromatic group or an aliphatic group), or a brominated polycarbonate system having the following formula (3): (In the formula, R represents hydrogen, an aromatic group, or an aliphatic group.) Alternatively, a brominated busphenol system having the following formula (4), (In the formula, R ¹ and R ² each represent hydrogen, an aromatic group or an aliphatic group, or a group represented by any one of the following formulas <i> to <vi>.

_{<I> -O-CH 2 -CHCH} 2 <ii> -O-CO-CH = CH 2 _{<Iv> -O-CH 2 -CH} 2 -O-CO-CH = CH 2 Furthermore, a brominated cyanuric acid system having the following formula (5) One or more solid flame retardants selected from any of the above flame retardants are used. Of course, these can be used together.

In the present invention, a flame retardant aid may be used in combination with such a flame retardant, if necessary, to bring about a synergistic effect in flame retardation.

As the flame retardant aid, for example, antimony oxide (antimony trioxide, antimony pentoxide), zirconium oxide or the like can be used.

These flame retardant aids may be used alone or in combination. In some cases, these flame retardant aids can be used alone or in combination as a flame retardant.

When antimony oxide is used, it is preferably dispersed in an organic solvent for easy handling.

In the present invention, these flame retardants, that is, to improve the adhesion between the solid flame retardant and the polyphenylene oxide resin, to improve the heat resistance and electrical insulation of the resin molded product, that is, the laminate, A solid flame retardant or a flame retardant and a flame retardant auxiliary are simultaneously added and mixed together with the silane coupling agent as described above to be contained in the resin composition.

In this case, the coupling surface treatment agent is a silane cup having an organic functional group such as a vinyl group, an epoxy group, an amino group, an acryl group, a mercapto group or an alkyl group, or a hydrolyzable group such as a methoxy group or an ethoxy group. A ring agent can be used. Epoxy silane,
Aminosilane, acryloxysilane, alkoxysilane and the like are shown as examples.

A reaction initiator is also mixed in the resin composition of the present invention.

As the initiator, the following two types can be selected depending on whether the polyphenylene oxide resin composition is an ultraviolet curing type or a thermosetting type, but is not limited thereto.

Examples of UV-curable photoinitiators (that is, those that generate radicals by UV irradiation) include benzoyl, benzyl, allyldiazonium fluoroborate, benzylmethyl ketal, 2,2-diethoxyacetophenone, benzoyl isobutyl ether, p- Tert-butyltrichloroacetophenone, benzyl (o-ethoxycarbonyl), α-monooxime, biacetyl, acetophenone, benzophenone, Michler's ketone, tetramethylthiuram sulfide, azobisisobutyronitrile and the like can be used.

Further, as the thermosetting initiator (that is, one that generates a radical by heat), dicumyl peroxide,
tert-butyl cumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy (hexyne-3,2,5-dimethyl-2, 5-di- (tert-butylperoxy) hexane, α, α′-bis (tert-butylperoxy-m-isopropyl) benzene [1,4 (or 1,
3) -bis (tert-butylperoxyisopropyl) benzene] and the like, 1-hydroxycyclohexylphenyl edone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- ( 4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, methylbenzoylformate, 4,4-bisdimethylaminobenzophenone (Michler's ketone), benzoin methyl ether, methyl-o-bay Zoyl benzoate, α-acyloxime ester, biscumyl of NOF CORPORATION, etc. can be used.

These initiators may be used alone or in combination of two or more.

Further, the initiator by ultraviolet rays and the initiator by heat may be used together.

The above-mentioned polyphenylene oxide, a crosslinkable polymer and / or monomer, a flame retardant or a flame retardant and a flame retardant aid, and a silane coupling agent, and a mixing ratio of the reaction initiator are usually preferably polyphenylene oxide 5 to 95% by weight, crosslinkable polymer / monomer 1 to 95% by weight, flame retardant 1 to 90% by weight, flame retardant auxiliary 1 to 50% by weight, silane coupling agent 0.5 to 15% by weight, reaction initiator 0.5 to 10% by weight % Is preferable.

Further, the resin composition of the present invention may further contain various inorganic fillers to change the properties such as the dielectric constant. As such an inorganic filler,
For example, titanium dioxide based ceramics, barium titanate based ceramics, lead titanate based ceramics, strontium titanate based ceramics, calcium titanate based ceramics, lead zirconate based ceramics and the like can be used alone or in combination.

The flame-retardant polyphenylene oxide resin composition of the present invention as described above is usually dissolved in a solvent, dispersed and mixed. In this case, the amount of the solvent used should be a 5 to 50 wt% solution of the flame-retardant polyphenylene oxide resin composition (or a resin solid content of 10 to 30 wt% with respect to the solvent). preferable. As the solvent, halogenated hydrocarbons such as trichloroethylene, trichloroethane, chloroform, methylene chloride and chlorobenzene, aromatic hydrocarbons such as benzene, toluene and xylene, acetone and carbon tetrachloride can be used, and trichloroethylene is particularly preferable. These may be used alone or in admixture of two or more.

In producing an electrical laminate such as a printed wiring board from the resin composition of the present invention, a sheet is formed from the flame retardant polyphenylene oxide resin composition, or a base material is impregnated with the sheet to form a prepreg. Further, if necessary, a core material or the like is produced from those sheets and prepregs, and then laminated and integrated with other base materials, films, prepregs, metal foils and the like according to a conventional method. The same applies to multilayer molding.

When forming a sheet from the flame-retardant polyphenylene oxide resin composition, for example, a casting method can be used.

The casting method is a method in which a resin mixed with a solvent is cast or applied to form a thin layer and then the solvent is removed to obtain a cured product. According to the casting method, a cured product can be obtained at a constant temperature without using the costly calendar method. More specifically, this casting method will be described. On an iron plate or a casting carrier-film or the like that is mirror-finished with a flame-retardant polyphenylene oxide resin composition in a state of being mixed with a solvent, for example, 5 to 700 (preferably Is 5 to 500)
A sheet is obtained by casting (or applying) to a thickness of μm and sufficiently drying to remove the solvent.

The carrier film for cashing is not particularly limited, but a polyethylene terephthalate (hereinafter abbreviated as "PET") film, a polyethylene film, a polypropylene film, a polyester film, a polyimide film, or the like which is insoluble in the above solvent is used. It is preferable that the release treatment is performed.

Drying is performed by air drying or hot air drying. The temperature range at that time is preferably lower than the boiling point of the solvent or lower than the heat resistant temperature of the casting carrier film (when drying is performed on the casting carrier film).

The lower limit should be determined by the drying time and processability. For example, trichlorethylene as a solvent and PET
When the film is used as a casting carrier film, the temperature is preferably in the range of room temperature to 80 ° C. If the temperature is raised within this range, the drying time can be shortened.

When a prepreg is produced by impregnating a substrate with the flame-retardant polyphenylene oxide resin machine composition of the present invention obtained by surface-treating a solid flame retardant, the following method can be generally adopted.

That is, the flame-retardant polyphenylene oxide resin composition is applied to the substrate by immersing (dipping) the substrate in a solvent dispersion of the flame-retardant polyphenylene oxide resin composition obtained by surface-treating the solid flame-retardant material. Is impregnated and attached. Then, the solvent is removed by drying or the like or semi-cured to obtain the B stage. The impregnated amount of the flame-retardant surface-treated / flame-retarded polyphenylene oxide resin composition in this case is not particularly limited, but is preferably 30 to 80% by weight. The base material is glass cloth, aramid cloth,
Cloths that can be impregnated with resin, such as polyester cloth and nylon cloth, mats made of these materials and /
Alternatively, a fibrous material such as a non-woven fabric, paper such as kraft paper, or linter paper can be used, but the material is not limited to these.

As the metal foil for forming a circuit used when forming the metal-clad laminate of the present invention, those generally used for wiring boards can be widely used. For example, a metal foil such as a copper foil or an aluminum foil can be used. In this case, it is preferable that the metal foil has a smooth adhesive surface and good conductivity in order to improve the characteristics of the printed wiring board.

With such a metal foil, a desired conductor can be formed by a subtractive method or the like. In addition, vapor deposition and additive methods (full additive method, semi-additive method)
For example, it may be formed as a desired conductor (circuit, electrode, etc.).

As a method for producing a laminated board using a core material, a sheet, and a prepreg produced from a flame-retardant polyphenylene oxide resin composition, for example, the following method can be used.

That is, the above-mentioned sheets and / or prepregs that have been appropriately dried are combined in a predetermined number so as to have a predetermined design thickness, and if necessary, a metal foil such as a conductive layer for wiring is also laminated, and heat-pressed. To melt the resin, sheet to sheet, sheet and prepreg or core material,
The prepregs are adhered to each other, the sheet and the metal foil, and the prepreg and the metal foil are adhered to each other to form a laminate. By this fusion, strong adhesion can be obtained, but if heating at this time is made to cause a crosslinking reaction by the reaction initiator, even stronger adhesion can be obtained. Such a crosslinking reaction is carried out by photocrosslinking such as ultraviolet irradiation, thermal crosslinking, crosslinking by irradiation of radiation, or the like.
Note that such adhesion may be performed by using an adhesive together.

Here, the combination of the sheet, the prepreg, and the core material is a combination, but is not particularly limited, but a vertically symmetrical combination is preferable from the viewpoint of warpage prevention after molding and secondary processing (etching etc.). Absent. Further, it is preferable to combine them so that the sheet comes to the adhesive interface with the metal foil, because the adhesive force can be improved.

The temperature at the time of heat pressing depends on the combination of the metal foil and the film or the prepreg, but for example, the adhesion between the metal foil and the sheet can utilize the heat fusion property of the sheet. Above the transition point, about 160
It is preferably in the range of about 300 ° C.

Further, when the flame-retardant material surface treatment / flame-retardant rack polyphenylene oxide-based resin composition of the present invention is crosslinked by heating in a dryer, the crosslinking reaction depends on the reaction temperature of the initiator used and the like. Therefore, the heating temperature and the heating time are selected according to the type of the initiator. For example, temperature 150-3
The temperature is 00 ° C and the time is about 10 to 60 minutes.

Clamping is carried out for the purpose of joining sheets, joining sheets and prepregs, joining prepregs, joining metal foils and sheets, joining metal foils and prepregs, etc., and adjusting the thickness of the laminated plate, so the pressing conditions are selected as necessary.

For example, the pressure can be about 30 to 80 kg / cm ² .

The heating and pressing as described above is carried out by heating and laminating a predetermined number of the film and / or prepreg in advance, and laminating a metal foil on one side or both sides thereof,
You may make it heat-tighten again.

(Operation) The flame-retardant polyphenylene oxide-based resin composition of the present invention is a polyphenylene oxide-based resin composition that improves the adhesion between the flame-retardant and the resin by coupling the solid flame-retardant with silane to improve the flame-retardant property. Exhibits excellent heat resistance and electrical insulation.

Therefore, the laminated board using the flame-retardant polyphenylene oxide resin composition of the present invention can be easily processed with high precision, is suitable for high-speed signal processing, and can realize high-density multi-layering.

Next, examples will be shown to further explain the flame-retardant polyphenylene oxide resin composition of the present invention and the metal-clad laminate of the present invention using the same.

(Example) Example 1 In a reactor equipped with a decompression device-Polyphenylene oxide (GE PPO) 300g-Styrene butadiene copolymer (Asahi Kasei Co., Ltd .; Sorprene T406) 350g-Triallyl isocyanurate (Nippon Kasei Co., Ltd.): TAI
C 40g ・ Dicumyl Peroxide (NOF: Percumyl D) 20g ・ Trichlororetylene (Toago Synthetic Chemistry: Triculene)
Along with 1000 g of the mixture, pentabromodiphenyl ether (Daiichi Kogyo Seiyaku, SR-250) as a flame retardant was used as a surface treatment silane coupling compound (Toshiba Silicone, TSL 8
173) and added and mixed, and sufficiently stirred until uniform, and after defoaming, a flame-retarded polyphenylene oxide resin composition is obtained.

This resin composition varnish was impregnated into a glass cloth base material (Nittobo: WE 116E) so that the resin amount was 50%, and the resin composition varnish was applied at
Dry for 0 minutes to produce a prepreg sheet.

Overlap these 4 sheets with the upper and lower copper foils,
A double-sided copper-clad laminate is obtained by pressing for 90 minutes under the condition of 0 kg / cm ² to integrate and laminate. This laminated plate was evaluated for flame retardancy, heat resistance, and electrical insulation.

 The results are shown in Table 1.

As is clear from the comparison with Comparative Examples described below, in the case of the resin composition of the present invention and a laminate using the same,
It can be seen that it has excellent heat resistance and electrical insulation as well as flame retardancy.

Comparative Examples 1 to 3 When the flame retardant was not added to the polyphenylene oxide resin composition (Comparative Example 1), when the flame retardant was added without mixing the silane coupling agent (Comparative Example 2), and when the silane coupling agent was used. In the case where the flame-retardant which had been surface-treated in advance was mixed (Comparative Example 3), a resin composition was produced, and this varnish was used to obtain a laminated plate in the same manner as in Example 1. The composition is shown in Table 1. Further, the physical properties of a laminated board using the resin composition were measured. The flame retardancy, heat resistance, and electric insulation were inferior, and the characteristics of the printed wiring board were not satisfactory.

(Effects of the Invention) According to the present invention, as described in detail above, the adhesion between the flame retardant and the resin is improved, and the polyphenylene oxide resin-impregnated resin sheet or resin sheet having good flame resistance, heat resistance, and electrical insulation is also provided. It is possible to realize a high-performance laminated board using the.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-148565 (JP, A) JP 60-32837 (JP, A) JP 57-49644 (JP, A)

Claims (1)

(57) [Claims] 1. A flame retardant selected from brominated diphenyl ether type, brominated polycarbonate type, brominated bisphenol type and brominated cyanuric acid type flame retardant together with polyphenylene oxide, a crosslinkable polymer and / or monomer and a reaction initiator. More than one solid flame retardant,
A flame-retardant polyphenylene oxide-based resin composition for an electric laminate, characterized by being mixed with a silane coupling agent.