JPH08253582A - Thermosetting resin composition and copper-clad laminate - Google Patents

Abstract

PURPOSE: To obtain a thermosetting resin composition having excellent flame retardancy and low dielectric properties by using a specified cyanate compound or its prepolymer and a halooligomer flame retardant as the essential components. CONSTITUTION: This resin composition essentially consists of a cyanate compound represented by formula I [wherein R1 and R2 are each a 1-10 C alkyl, t-Bu is t-butyl; and X is a group represented by formula II (wherein R3 and R4 are each H or a 1-5 C alkyl)] or its prepolymer (A) and a halooligomer flame retardant (B) having an average molecular weight of 1000-100000. It is desirable that component B is a brominated polyphenylene oxide oligomer represented by formula III (wherein (n) is 2-397), a brominated polycarbonate oligomer represented by formula IV (wherein R5 is H or Br; and m=1-175) or a brominated acrylate oligomer represented by formula V (wherein p=2-414; and q=1-5).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition containing a cyanate compound and an oligomer type flame retardant as essential components, and a copper clad laminate using the thermosetting resin composition. INDUSTRIAL APPLICABILITY The thermosetting resin composition and the copper clad laminate of the present invention are particularly useful as a printed wiring board that requires a low dielectric constant.

[0002]

2. Description of the Related Art In recent years, as the number of printed wiring boards has increased, the low dielectric property of resins has been required mainly for the purpose of improving the signal speed. Due to such requirements, cyanate compounds have come to be used and have been proposed in German Patent No. 2533122, International Patent No. 88/05443 and the like. A bisphenol A dicyanate is known as a cyanate generally used at present. It is known that the above cyanate compound is generally used as a resin composition and is commonly used with a bismaleimide or an epoxy compound or the like (Japanese Patent Publication No. 54-30440) depending on its required characteristics. In addition, when imparting flame retardancy to a resin composition, a brominated epoxy compound which is a reactive flame retardant is generally used. However, when low dielectric constant is required, it is a non-reactive flame retardant containing Br. Polycarbonate oligomers are used. However, with the advancement of computer technology, it has been required to further reduce the dielectric constant of resin compositions.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a copper-clad laminate having flame retardancy while maintaining the conventional properties, and further having excellent low dielectric property, low dielectric loss tangent property, and moisture resistance. And to provide a cyanate resin composition that provides it.

[0004]

Means for Solving the Problems As a result of intensive studies on the skeleton structure of a cyanate compound, the present inventors have a bulky t-butyl group at the 2-position with respect to a cyanate group on a benzene ring, Furthermore, they have found that a copper-clad laminate using a specific cyanate compound having an alkyl substituent at the 5-position and an oligomer type flame retardant satisfies the above-mentioned object, and completed the present invention. That is, the present invention is as follows. (1) The following general formula (1)

[Chemical 6] [In the formula, R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms. t-Bu is a t-butyl group. X is the following general formula (2)

[Chemical 7] (In the formula, R ₃ and R ₄ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). ] The cyanate compound represented by these, or its prepolymer, and (B) average molecular weight 1000-1.
A thermosetting resin composition containing, as an essential component, a halogen-containing oligomer type flame retardant of 00000.

(2) A copper-clad laminate obtained by heat-molding a prepreg obtained by impregnating a substrate with a solution prepared by dissolving the thermosetting resin composition of (1) in an organic solvent, and a copper foil.

The cyanate compound which is an essential component of the resin composition of the present invention has the following general formula (6):

[0007]

Embedded image (In the formula, X, R ₁ and R ₂ are defined in the same manner as in the general formula (1).) A bisphenol compound represented by the general formula (1) and a cyanogen halide represented by chlorocyan and bromocyan are suitable organic solvents. It can be obtained by carrying out a dehydrohalogenation reaction in the presence of a base.

As the above-mentioned bisphenols, those obtained by any known method can be used.

As a general method for producing sulfur-containing bisphenols, a method in which phenols and sulfur monochloride are reacted in a formamide solvent (Japanese Patent Laid-Open No. 262719/1993), phenols and sulfur monochloride are reacted to form polysulfides. Examples of known methods include, but are not limited to, a method of reducing with a bismuth compound, a mineral acid, and zinc after that (Japanese Patent Laid-Open No. 4-283560).

Of bisphenols containing no sulfur atom,
As a general production method, a carbonyl compound and a phenol are reacted in the presence of an acid catalyst.
Not limited to this.

As the carbonyl compound, a compound having a carbonyl group having 1 to 11 carbon atoms is used. Typical examples are formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentylaldehyde, hexylaldehyde and the like. Aldehyde compounds; ketone compounds represented by acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, ethyl propyl ketone, diethyl ketone, dipropyl ketone, dibutyl ketone and the like can be mentioned.

Among these carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde are preferable as aldehydes for achieving the object of the present invention.

Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone and dibutyl ketone.

The phenols used here are t-
A butyl group at the 2-position with respect to the OH group, having no substituent at the 4-position, and further having an alkyl group having 10 or less carbon atoms at the 5-position is used. Two
Examples thereof include -t-butyl-5-methylphenol, 2-t-butyl-5-ethylphenol, 2-t-butyl-5-isopropylphenol and the like. Among these phenols, 2-t-butyl-5-methylphenol is more preferable for achieving the object of the present invention.

The cyanate compound used in the present invention may be used as a monomer or as a prepolymer. The prepolymer is prepared by heating the cyanate compound alone or as a mixture with an oligomer type flame retardant at 50 to 200 ° C. in a solvent or a bulk, or together with a curing catalyst described below in a solvent or a bulk at 50 to 200 ° C.
It can be obtained by heating to about 200 ° C.

As a curing catalyst for the resin composition of the present invention,
It is possible to use a known one. For example, protic acid typified by hydrochloric acid and phosphoric acid; aluminum chloride,
Boron trifluoride complex, Lewis acid represented by zinc chloride;
Aromatic hydroxy compounds typified by phenol, pyrocatechol, and dihydroxynaphthalene; organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, and cobalt octylate; organic metals such as copper acetylacetonate and aluminum acetylacetonate Complexes; tertiary amines such as triethylamine, tributylamine, quinoline and isoquinoline; quaternary ammonium salts represented by tetraethylammonium chloride and tetrabutylammonium bromide; imidazoles; sodium hydroxide, sodium methylate, diazabicyclo [2] , 2,2] octane, triphenylphosphine, or a mixture thereof.

Among these curing catalysts, more preferable for achieving the object, organic metal salts such as zinc naphthenate, cobalt octylate and tin octylate, organic metal complexes such as copper acetylacetonate, imidazoles and phenols. Alternatively, a mixed system thereof may be used.

In the resin composition of the present invention, in addition to the curing catalyst used for prepolymerization, the above curing catalyst can be further added and used.

The oligomer type flame retardant used in the present invention is a polymer having an average molecular weight of 1,000 to 100,000, and includes Br-containing polyphenylene oxide (PPO) oligomer, Br-containing polycarbonate oligomer and Br-containing polycarbonate oligomer.
Examples include, but are not limited to, styrene oligomers containing, acrylate oligomers containing Br, epoxy oligomers containing Br, acenaphthylene oligomers containing Br, and the like.

Among these oligomer type flame retardants, Br-containing PPO oligomers, Br-containing polycarbonate oligomers, Br-containing styrene oligomers and Br-containing acrylate oligomers are more preferable for achieving the object. These oligomers are represented by the following structural formulas.

Structural formula (3)

[Chemical 9] (In the formula, n represents a number of 2 or more and 397 or less.) Structural formula (4)

[0022]

[Chemical 10] (In the formula, R ₅ is a hydrogen atom or a bromine atom, and m represents a number of 1 or more and 175 or less.) Structural formula (5)

[0023]

[Chemical 11] (In the formula, p represents a number of 2 or more and 414 or less. Further, q is 1
It represents an integer of 5 or more and 5 or less. )

When the average molecular weight of the oligomer type flame retardant is larger than 100,000, there is a problem in compatibility with the cyanate compound, and when the average molecular weight is smaller than 1000, the Tg of the obtained cured product is greatly lowered. It is not preferable.

The mixing ratio of the oligomer-type flame retardant can take any value, but in order to achieve the object, it is preferably added to the resin composition so that the Br content is in the range of 5 to 20%. good.

In the resin composition of the present invention, reactive flame retardants such as diglycidyl ether of brominated bisphenol A, glycidyl ether of brominated phenol novolac, brominated bisphenol A, tribromophenyl maleimide, etc., within the range not impairing the purpose. Can be used together.

Other thermosetting resins can be used in combination with the resin composition of the present invention as long as the purpose is not impaired. For example, epoxy resins represented by diglycidyl ethers of bisphenol A and bisphenol F, glycidyl ethers of phenol novolac and cresol novolac, and addition polymers of bismaleimides or bismaleimides and diamine compounds; bisphenol A and tetra Alkenyl aryl ethers or amine resins represented by bisvinylbenzyl ether compounds of bromobisphenol A and vinylbenzyl compounds of diaminodiphenylmethane; alkynyl ethers represented by dipropargyl ethers of bisphenol A and tetrabromobisphenol A and propargyl ethers of diaminodiphenylmethane. Or amine resin; Others, phenol resin, resole resin, allyl ether compound, allyl amine compound Compound, triallyl isocyanurate, triallyl cyanurate, although a vinyl group-containing polyolefin compounds, and the like, without limitation. Thermoplastic resins can also be added and include, but are not limited to, polyphenylene ether, polystyrene, polyethylene, polybutadiene, polyimide, and modified products thereof. These resins may be mixed in the cyanate resin composition, or may be reacted in advance and used.

In the present invention, known additives such as a release agent, an inorganic flame retardant, a surface treatment agent and a filler may be added to the composition depending on the purpose. Examples of the release agent include waxes and zinc stearate, examples of the inorganic flame retardant include antimony trioxide and red phosphorus, and examples of the surface treatment agent include a silane coupling agent. Examples of the filler include silica, alumina, talc, clay and the like.

The copper-clad laminate using the cyanate resin composition of the present invention is used for a printed wiring board which requires low dielectric properties. The copper-clad laminate of the present invention can be manufactured by a known method. That is, a base material is impregnated with a resin varnish that is a solution of a thermosetting resin composition containing a cyanate compound or the like dissolved in an organic solvent, and heat-treated to form a prepreg, and then a prepreg and a copper foil are laminated and heat-molded. Is a copper-clad laminate.

The organic solvent used is acetone,
Examples thereof include methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol dimethyl ether, toluene, xylene, 1,4-dioxane, tetrahydrofuran, N, N-dimethylformamide and the like, or a mixture of two or more thereof.

As the base material to be impregnated with the resin varnish, woven cloth or non-woven cloth made of inorganic or organic fibers such as glass fiber, alumina fiber, polyester fiber and polyamide fiber,
Examples include matte, paper, or a combination thereof.

The heat treatment conditions for the prepreg are appropriately selected depending on the type and amount of the solvent to be used, the added catalyst, and other various additives, but usually 3 to 30 minutes at a temperature of 100 to 200 ° C. It is performed under the conditions.

As a method of laminating and heat-molding a prepreg and a copper foil, 10 kg / c at a temperature of 150 ° C. to 300 ° C.
20 minutes to 300 at a molding pressure of m ^{2 to} 100 kg / cm ^2.
A method of hot press molding in minutes is exemplified.

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto.

Synthesis Example 1 This synthesis example is a cyanate compound used in the present invention,
The present invention relates to a method for producing a dicyanate of 1,1-bis (5-t-butyl-2-methyl-4-hydroxyphenyl) butane. 1,1-bis (5-t-butyl-2-methyl-4-hydroxyphenyl) butane (Sumitomo Chemical Co., Ltd., trade name Sumilizer BBM-S) 107.0
g (0.28 mol) and triethylamine 79.2 g
(0.78 mol) to methyl isobutyl ketone 600
g, and cooled to 0 ° C. While stirring the reaction solution, 48.0 g (0.78 mol) of chlorcian was added dropwise over 1 hour while paying attention not to let the reaction temperature rise to 3 ° C. or higher, and stirred for another 30 minutes after the completion of the addition. After completion of the reaction, the product was washed with 300 ml of water three times to remove triethylamine hydrochloride. Distill off the methyl isobutyl ketone,
Further, 200 g of methanol was added for crystallization, and the precipitate was filtered, washed with cold methanol and dried to obtain the dicyanate of bis (5-t-butyl-2-methyl-4-cyanatophenyl) butane, which is the target product. 115 g (yield 95%) was obtained as white crystals.

Synthesis Example 2 This synthesis example relates to a process for producing the cyanate compound, bis (5-t-butyl-2-methyl-4-cyanatophenyl) sulfide, used in the present invention. 1,1-
Bis (5-t-butyl-2-methyl-4-hydroxyphenyl) sulfide (Sumitomo Chemical Co., Ltd., trade name Sumilizer WXR) 100 g (0.28 mol) and triethylamine 79.2 g (0.78 mol), It was dissolved in 600 g of methyl isobutyl ketone and cooled to 0 ° C.
While stirring the reaction solution, 48.0 g (0.
78 mol) was added dropwise over 1 hour, taking care not to let the reaction temperature rise above 3 ° C.
Stir for 0 minutes. After completion of the reaction, the product was washed with 300 ml of water three times to remove triethylamine hydrochloride. Methyl isobutyl ketone was distilled off, 200 g of methanol was further added for crystallization, and the precipitate was filtered and washed with cold methanol.
By drying, 108 g (yield 95%) of the target product, bis (5-t-butyl-2-methyl-4-cyanatophenyl) sulfide, was obtained as white crystals.

Examples 1 to 6 This example relates to an example of producing a cured product of a resin composition using the cyanate compound obtained in Synthesis Examples 1 and 2 and an oligomer type flame retardant. 0.5 parts of zinc naphthenate was melt-mixed with the cyanate compounds obtained in Synthesis Examples 1 and 2, and prepolymerization was performed at 140 ° C. for 10 minutes. After that, an oligomer type flame retardant and zinc naphthenate were further added to the obtained prepolymerized product so that the compounding ratio was as shown in Table 1. This formulation was again melt mixed and B-staged at 170 ° C. 2 semi-cured products after B stage
The desired cured product was obtained by hot pressing for 2 hours under the conditions of 00 ° C./50 kg / cm ² . Table 1 shows the physical properties of the obtained cured resin alone. In Table 1, the numerical value of zinc naphthenate is the number of parts by weight of the total amount of the curing catalyst used up to the B stage. In addition, Br-containing polyphenylene oxide (Br content 62%) and Br-containing polycarbonate oligomer (Br content 58%) were used in the product of Great Lake.
Chemical-made Br-containing acrylate oligomer (Br content 70.5%) is Ameri.
A product manufactured by brom bromine compounds was used.

Examples 6 to 12 This example relates to an example of producing a copper clad laminate using the cyanate compound obtained in Synthesis Examples 1 and 2 and an oligomer type flame retardant. The cyanate compounds obtained in Synthesis Examples 1 and 2 were prepolymerized under the same conditions as in Examples 1 to 6. An oligomer type flame retardant and zinc naphthenate were added to the obtained prepolymerized product to obtain the compounding ratio shown in Table 2. This resin composition was dissolved in tetrahydrofuran to form a uniform resin varnish. A glass cloth (trade name: KS-1600S962LP, manufactured by Kanebo Co., Ltd.) was impregnated with the varnish and treated with a hot air dryer at 160 ° C. for 6 minutes to obtain a prepreg. 5 prepregs and copper foil (TSTO treatment, 35μm
The thickness and Furukawa Circuit Foil Co., Ltd. are piled up,
Hot pressing was performed at 200 ° C. for 2 hours to obtain a copper-clad laminate having a thickness of 1 mm. Table 2 shows the physical properties of the obtained copper-clad laminate. The method of displaying the blending ratio in Table 2 is in accordance with Table 1.

Comparative Example 1 2,2-bis (4-cyanatophenyl) propane was added to
Melt mix 0.05 parts zinc naphthenate, 140 ℃
Was prepolymerized for 10 minutes. Then, the Br-containing polycarbonate oligomer and zinc naphthenate were added to the obtained prepolymerized product to give the blending ratios shown in Table 1. The resin composition is melt-mixed again at 170 ° C.
I went to stage B. The semi-cured product after the B stage was hot-pressed for 2 hours under the condition of 200 ° C./50 kg / cm ² to obtain a desired cured product. Table 1 shows the physical properties of the obtained cured resin alone.

Comparative Example 2 2,2-bis (4-cyanatophenyl) propane was prepolymerized under the same conditions as in Comparative Example 1. A Br-containing polycarbonate oligomer and zinc naphthenate were added to the obtained prepolymerized product to obtain the compounding ratios shown in Table 2. The obtained resin composition was dissolved in methyl ethyl ketone to form a uniform resin varnish. Glass varnish (trade name: KS-1600S962LP, manufactured by Kanebo Co., Ltd.)
Was impregnated with the above and treated with a hot air dryer at 160 ° C. for 5 minutes to obtain a prepreg. 5 prepregs and copper foil (TSTO treatment, 3
5 μm-thick Furukawa Circuit Foil Co., Ltd. was overlaid and heat pressed at 200 ° C. for 2 hours to obtain a 1 mm-thick copper-clad laminate. Table 2 shows the physical properties of the obtained copper-clad laminate.

[0040]

[Table 1]

[0041]

[Table 2]

In Tables 1 and 2, the physical properties were measured by the following methods. -Glass transition temperature: It was determined from the inflection point of the thermal expansion curve using a thermomechanical analyzer DT-30 manufactured by Shimadzu Corporation. -Dielectric constant, dielectric loss tangent: Calculated from the value of capacitance obtained using a 4275A Multi-Frequency LCR meter, manufactured by Yokogawa Hewlett-Packard Co., Ltd.・ Copper foil peel strength, boiling water absorption, solder heat resistance are JIS-
According to C-6481, flame retardancy was evaluated by the vertical method according to UL-94 standard.

[0043]

The copper-clad laminate using the cyanate resin composition of the present invention is excellent in low dielectric property, low dielectric loss tangent property, low hygroscopicity, and high flame retardancy (for example, UL standard V-0 grade). Have. This copper-clad laminate is particularly useful as a printed wiring board that requires low dielectric properties.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H05K 1/03 610 7511-4E H05K 1/03 610H 1/09 7511-4E 1/09 D

Claims (5)

[Claims] 1. (A) The following general formula (1): [In the formula, R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms. t-Bu is a t-butyl group. X is the following general formula (2): (In the formula, R ₃ and R ₄ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). ] The cyanate compound represented by these, or its prepolymer, and (B) average molecular weight 1000-10.
A thermosetting resin composition containing, as an essential component, a halogen-containing oligomer type flame retardant of 0000. 2. The component (B) has the following structural formula (3): The thermosetting resin composition according to claim 1, which is a Br-containing polyphenylene oxide oligomer represented by the formula (n represents a number of 2 or more and 397 or less). 3. The component (B) has the following structural formula (4): The thermosetting resin composition according to claim 1, which is a Br-containing polycarbonate oligomer represented by the formula: wherein R ₅ is a hydrogen atom or a bromine atom, and m is a number of 1 or more and 175 or less. 4. The component (B) has the following structural formula (5): (In the formula, p represents a number of 2 or more and 414 or less. Further, q is 1
It represents an integer of 5 or more and 5 or less. The thermosetting resin composition according to claim 1, which is a Br-containing acrylate oligomer represented by the formula (1). 5. A prepreg obtained by impregnating a substrate with a solution prepared by dissolving the thermosetting resin composition according to claim 1, 2, 3 or 4 in an organic solvent and a copper foil are heat-molded. Copper-clad laminate.