JP2001214029A - Flame retardant high-permittivity resin composition, flame retardant high-permittivity prepreg and flame retardant high-permittivity laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame retardant high-permittibity resin composition and a prepreg and a laminated sheet using the resin composition, especially a laminated sheet useful as a printed wiring board because the development of a high-permittivity laminated sheet satisfying the flame retardance UL94V-0 without containing a halogen substance and an antimony compound is not succeeded though the high-permittivity laminated sheet satisfying the flame retardance UL94V-0 without containing the halogen substance and antimony compound is demanded. SOLUTION: This flame retardant high-permittivity resin composition is characterized in that the resin composition consists essentially of (a) a resin having a dihydrobenzoxazine ring in the molecule, (b) a resin component composed of a compound exhibiting the reactivity with the dihydrobenzoxazine ring and a phenolic hydroxyl group produced by opening the ring of the dihydrobenzoxazine ring, (c) a high-permittivity inorganic powder and (d) a resin component or an inorganic powder composed of at least one or more kinds of an inorganic hydrate, a nitrogen-bases compound and a phosphorus-based compound and all the materials used have <=0.1 wt.% contents of the halogen and the antimony compound. The flame retardant high-permittivity prepreg is prepared by impregnating a substrate with the flame retardant high-permittivity resin composition and drying the resultant substrate. The flame retardant high-permittivity laminates sheet is obtained by hot-pressing the high-permittivity prepreg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant high dielectric constant resin composition, a flame-retardant high dielectric constant prepreg, and a flame-retardant high dielectric constant laminate.

[0002]

2. Description of the Related Art In recent years, with various developments in electronic technology, various performances have been required for insulating materials used in electronic devices. In particular, printed wiring boards are used for a very wide range of applications, and the characteristics required for the boards are also increasingly diverse. Under these circumstances, there are many demands for dielectric properties. Until now, we have been developing low dielectric constant wiring boards for the purpose of high-speed propagation, high characteristic impedance, thinner wiring boards, and reduced crosstalk in printed wiring boards. A high-dielectric-constant laminate is required for the purpose of forming, lowering impedance, forming a composite circuit of an element having a capacitor effect on the laminate itself, and the like.

Conventionally, as a high dielectric constant laminate, glass or glass non-woven fabric is used as a base material, and a prepreg impregnated and dried with an epoxy resin varnish containing an inorganic powder having a high dielectric constant is formed on the base material. A high dielectric constant laminate has been proposed.

However, from the viewpoint of safety, electrical insulating materials including high dielectric laminates are required to have high flame retardancy.
It has been flame retarded mainly by using brominated flame retardants. However, in recent years, the use of substances has been increasingly regulated in terms of environmental pollution and toxicity. In particular, the toxicity and carcinogenicity of organic halogen substances such as dioxin have become a problem. Strongly required. Also, due to the carcinogenicity of antimony, there is a growing demand for reducing and reducing antimony compounds.

[0005] Therefore, there is a need for a high dielectric constant laminate that does not contain a halogen substance and an antimony compound and satisfies the flame-retardant UL94V-0. However, it does not contain a halogen substance and an antimony compound, and has a flame-retardant UL.
The fact is that a high dielectric constant laminate satisfying 94V-0 has not been successfully developed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to provide a flame-retardant resin composition having a high dielectric constant and a prepreg and a laminate, particularly a printed wiring board using the same. The present invention is to provide a laminate plate useful as a.

[0007]

[Means for Solving the Problems] (a) a resin having a dihydrobenzoxazine ring in the molecule, (b) a resin component comprising a compound having reactivity with a phenolic hydroxyl group generated by opening of the dihydrobenzoxazine ring and the dihydrobenzoxazine ring, (C) An inorganic powder having a high dielectric constant and (d) a compound comprising at least one of inorganic hydrates, nitrogen-based compounds, and phosphorus-based compounds as essential components, and containing all halogen and antimony compounds, A flame-retardant high dielectric constant resin composition, which is 0.1% by weight or less. 2. The resin component comprising a compound having a reactivity with a phenolic hydroxyl group formed by opening a dihydrobenzoxazine ring and a dihydrobenzoxazine ring is a polycondensate of a phenol, a compound having a triazine ring and an aldehyde. Item 2. The flame-retardant high dielectric constant resin composition according to item 1. Item 1-2 wherein the inorganic hydrate is aluminum hydroxide
The flame-retardant high dielectric constant resin composition according to the above. 4. Item 4. A flame-retardant high-dielectric-constant prepreg obtained by impregnating a substrate with the flame-retardant high-dielectric-constant resin composition according to any one of items 1 to 3, and drying. 5. Item 6. A flame-retardant high dielectric constant laminate obtained by heating and pressing the high dielectric constant prepreg according to Item 4.

[0008]

DETAILED DESCRIPTION OF THE INVENTION (a) The thermosetting resin having a dihydrobenzoxazine ring is not particularly limited as long as it has a dihydrobenzoxazine ring and is cured by a ring opening reaction of the dihydrobenzoxazine ring. Instead, it is synthesized from a compound having a phenolic hydroxyl group, formalin and a primary amine by Chemical Formula 1.

[0009]

Embedded image

(In the formula, R ¹ is an alkyl group, a cyclohexyl group, a phenyl group or a phenyl group substituted with an alkyl group or an alkoxyl group.) As a compound having a phenolic hydroxyl group, polyfunctional phenol, biphenol compound, bisphenol Examples include compounds, trisphenol compounds, tetraphenol compounds, and phenol resins.

[0011] Polyfunctional phenols include catechol, hydroquinone and resorquinol. Examples of the bisphenol compound include bisphenol A, bisphenol F and positional isomers thereof, bisphenol S, and tetrafluorobisphenol A. Examples of the phenol resin include a resol resin, a phenol novolak resin, a phenol-modified xylene resin, an alkylphenol resin, a melamine phenol resin, a benzoguanamine phenol resin, and a phenol-modified polybutadiene.

Examples of the primary amine include methylamine, cyclohexylamine, aniline, substituted aniline and the like.

In the present invention, a mixture of a compound having a phenolic hydroxyl group and a primary amine is added to an aldehyde heated to 70 ° C. or higher and reacted at 70 to 110 ° C., preferably 90 to 100 ° C. for 20 to 120 minutes. And then 1
It can be synthesized by drying under reduced pressure at a temperature of 20 ° C. or less.

The functional group of the resin component consisting of a compound having a reactivity with a phenolic hydroxyl group formed by opening of the dihydrooxazine ring and the dihydrooxazine ring in (b) includes a dihydrooxazine ring in the molecule of (a). Those which also show reactivity with the phenolic hydroxyl groups remaining in the resin having

Specific examples of the compound include a compound having a phenolic hydroxyl group and a bifunctional or higher functional epoxy resin.

Preferably, a compound having a reactivity with a resin having a dihydrobenzoxazine ring in the molecule, a phenol and a compound having a triazine ring, which are expected to have improved flame retardancy without lowering heat resistance such as Tg and heat resistance. And polycondensates of aldehydes.

The phenol used for obtaining the polycondensate of the phenol and the aldehyde having a triazine ring is not particularly limited. Examples thereof include phenol, cresol, xylenol, ethylphenol, butylphenol and the like. And polyphenols such as bisphenol A, bisphenol F, bisphenol S, resorcinol and catechol, phenylphenol and aminophenol. The use of these phenols is not limited to one kind alone, and two or more kinds can be used in combination.

Further, the compound having a triazine ring for obtaining a polycondensate of the compound having a phenol, a triazine ring and an aldehyde according to the present invention is not particularly limited, but has the following general formula (I) It is preferred that I) and / or general formula (II).

[0019]

Embedded image (Wherein, R ₁ , R ₂ , and R ₃ represent any of an amino group, an alkyl group, a phenyl group, a hydroxyl group, a hydroxylalkyl group, an ether group, an ester group, an acid group, an unsaturated group, and a cyano group) .)

[0020]

Embedded image (Wherein, R ₄ , R ₅ , and R ₆ represent any of an amino group, an alkyl group, a phenyl group, a hydroxyl group, a hydroxylalkyl group, an ether group, an ester group, an acid group, an unsaturated group, and a cyano group) .)

In the general formula (I), it is desirable that at least one of R ₁ , R ₂ and R ₃ is an amino group.

The compound represented by the general formula (I) includes
Specific examples include melamine, guanamine derivatives such as acetoguanamine and benzoguanamine, and cyanuric acid, and cyanuric acid derivatives such as methyl cyanurate, ethyl cyanurate, acetyl cyanurate, and cyanuric chloride. In order to use as a curing agent, any one of R ₁ , R ₂ , and R ₃ may be used.
One or three are preferably amino groups.

The compound represented by the general formula (II) includes
Specifically, for example, isocyanuric acid, or isocyanuric acid derivatives such as methyl isocyanurate, ethyl isocyanurate, allyl isocyanurate, 2-hydroxyethyl isocyanurate, 2-carboxyethyl isocyanurate, chlorinated isocyanuric acid, and the like can be given. .

The use of these compounds is not limited to one kind, and two or more kinds can be used in combination. Aldehydes for obtaining the phenolic resin composition of the present invention are not limited, but formaldehyde is preferred from the viewpoint of easy handling. The formaldehyde is not limited, but typical sources include formalin, paraformaldehyde and the like.

A typical method for obtaining a reaction product of a phenol, a compound having a triazine ring and an aldehyde will be described below. First, the above-mentioned phenols, aldehydes, and compounds having a triazine ring are reacted under basic or acidic catalysis. At this time the pH of the system
Although is not particularly limited, most of the compounds containing a triazine ring are easily dissolved in a basic solution, and thus it is preferable to carry out the reaction by basic catalysis, and it is more preferable to use amines. The order of reaction of each raw material is not particularly limited. Even if a phenol and an aldehyde are reacted first and then a compound having a triazine ring is added, on the contrary, the phenol and the aldehyde are reacted with the compound having a triazine ring and the aldehyde. Or all the raw materials may be added and reacted at the same time.

At this time, the molar ratio of the aldehyde to the phenol is not particularly limited, but may be 0.2%.
１．５1.5, preferably 0.4 to 0.8. The weight ratio of the compound having a triazine ring to the phenol is (10 to 98) :( 90 to 2), preferably (50 to 95) :( 50 to 5). If the weight ratio of the phenols is less than 10%, it becomes difficult to convert the resin into a resin, and if it is more than 98%, a sufficient flame retardant effect cannot be obtained.

The catalyst is not particularly limited, but typical examples thereof include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide and barium hydroxide, and oxidation of these. Substances, ammonia, primary to tertiary amines, hexamethylenetetramine, sodium carbonate, etc., and inorganic acids such as hydrochloric acid, sulfuric acid, sulfonic acid, etc., organic acids such as oxalic acid, acetic acid, divalent acids such as Lewis acid or zinc acetate There are metal salts and the like.

Since it is not preferable that inorganic substances such as metals remain as catalyst residues, it is preferable to use amines as the basic catalyst and organic acids as the acidic catalyst. Further, the reaction may be carried out in the presence of various solvents from the viewpoint of reaction control. Next, if necessary, neutralization and washing are performed to remove impurities such as salts. However, when amines are used as the catalyst, it is preferable not to carry out. After the completion of the reaction, unreacted aldehydes, phenols, solvents and the like are removed according to ordinary methods such as atmospheric distillation and vacuum distillation. At this time,
Unreacted aldehydes and methylols are preferably removed, and a heat treatment at 120 ° C. or higher is required to obtain a resin composition substantially free of unreacted aldehydes and methylol groups. At this time, it is preferable to sufficiently heat and distill according to a conventional method for obtaining a novolak resin. Although not particularly limited, at this time, as described above, the content of the unreacted monofunctional phenol monomer is preferably 2% or less.

The product thus obtained is a polycondensate of a phenol, a compound having a triazine ring and an aldehyde.

The inorganic powder (c) preferably has a dielectric constant of 10 or more, more preferably 30 or more. Further, it is preferable that the inorganic powder of (c) has a dielectric loss tangent of 0.005 or less. Specific examples of the inorganic powder (c) include a titanium dioxide ceramic, a strontium titanate ceramic, and a calcium titanate ceramic. Table 1 shows the values of the dielectric constant and the dielectric loss tangent.

[Table 1]

These may be used alone or in combination of two or more. In addition, the titanium dioxide-based ceramic is compositionally composed of titanium dioxide or a material containing a small amount of other additives in titanium dioxide, and retains the crystal structure of titanium dioxide as a main component. Things. The same applies to other ceramics. Titanium dioxide is a substance represented by TiO ₂ and has various crystal structures, but a rutile structure having stability at high temperatures is preferably used as a derivative ceramic.

The amount of the inorganic powder (c) to be added to the resin is preferably as large as possible in order to increase the dielectric constant, but is preferably based on 100 parts by weight of the total amount of the components (a), (b) and (d). 80 to 250 parts by weight, preferably 100 to 200 parts by weight.
Parts by weight are more preferred. This is because as the addition amount of the inorganic powder increases, it becomes difficult to uniformly disperse and mix the resin, and the mechanical strength after lamination decreases, and conversely, if the addition amount is small, the dielectric constant does not become sufficiently high. It is.

Examples of the inorganic hydrate (d) include magnesium hydroxide and aluminum hydroxide. The addition of the inorganic hydrate increases the total amount of the filler, making it difficult to uniformly disperse and mix the resin in the resin. Therefore, it is necessary to reduce the amount of the inorganic hydrate as much as possible. Preferably, it is an inorganic hydrate which has good flame retardancy and is stable to acids and alkalis. Therefore, aluminum hydroxide has a larger number of waters of hydration than magnesium hydroxide and other inorganic hydrates, has good flame retardancy, and is relatively stable and suitable for acids and alkalis. . The mixing amount of the inorganic hydrate is 0 to 150 with respect to the total amount of the components (a) and (b).
Parts by weight are preferred.

Examples of the nitrogen compound include organic fillers such as melamine, melamine cyanurate, cyanuric acid, melamine sulfate and melamine phosphate, and polycondensates of phenols and compounds having a triazine ring with aldehydes.

As the phosphorus-based flame retardant, phosphines such as triphenylphosphine, phosphates, phosphonite, phosphite, phosphazene, melamine phosphate and the like can be used. The total amount of the nitrogen-based compound and the phosphorus-based flame retardant is preferably 0 to 100 parts by weight based on the total amount of the components (a) and (b). If these are too large, the water absorption tends to increase and the heat resistance tends to decrease, and the glass transition temperature tends to decrease and the reliability tends to decrease.

Thermosetting resin [(a) component and (b) component]
In order to make the curing reaction effective, an appropriate curing agent,
As a result of intensive studies on the accelerator, it was found that imidazoles were effective. From the viewpoint of the curing time of the varnish and the moldability, the amount of addition is preferably 0.1 to 5% by weight, more preferably 0.2 to 1.5% by weight, based on the solid content of the resin.

The flame-retardant high dielectric constant resin composition of the present invention is dissolved in a solvent to form a varnish, and applied to a substrate and impregnated.
However, the inorganic powder is uniformly dispersed and mixed in the varnish. Examples of the solvent include alcohols such as methanol, ether solvents, ketone solvents such as methyl ethyl ketone, N,
Examples thereof include amide solvents such as N-imethylacetamide, aromatic hydrocarbons such as toluene and xylene, ester solvents such as ethyl acetate, and nitrile solvents such as acetonitrile.

Next, a method for manufacturing a laminate will be described. The varnish is impregnated and dried in a glass cloth or glass nonwoven fabric to prepare a prepreg. The laminate is obtained by laminating and laminating a required number of prepregs.

[0039]

The dihydrobenzoxazine compound used in the present invention has a high aromatic content and is a nitrogen-containing compound, so that it has excellent flame retardancy and is easily flame retarded. Utilizing the knowledge that a laminated board having a high dielectric constant can be obtained by dispersing and containing a high inorganic powder, furthermore, by selecting a compound that reacts with a dihydrobenzoxazine compound and combining a non-halogen flame retardant, it becomes difficult It is possible to obtain a high dielectric resin composition having excellent balance of flammability, dielectric properties, heat resistance and other properties.

[0040]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples of the present invention and Comparative Examples thereof, but the present invention is not limited to these Examples.

Example 1 [1] Synthesis of resin having dihydrobenzoxazine ring (1) Synthesis of phenol novolak 1.9 kg of phenol, formalin (37% aqueous solution)
1.15 kg and 4 g of oxalic acid were charged into a 5-liter flask and reacted at a reflux temperature for 6 hours. Subsequently, the internal pressure was reduced to 6666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 89 ° C. (ring and ball method), trinuclear or more dinuclear ratio = 89/11 (peak area ratio by gel permeation chromatography). (2) Introduction of dihydrobenzoxazine ring 1.7 k of phenol novolak resin synthesized above
g (equivalent to 16 mol of hydroxyl groups) to aniline 1.
49 kg (corresponding to 16 mol) was stirred at 80 ° C. for 5 hours to prepare a uniform mixed solution. In a 5 liter flask, 1.62 kg of formalin was charged and heated to 90 ° C.
The novolak / aniline mixed solution was gradually added thereto over 30 minutes. 30 minutes after the completion of the addition, the mixture was kept at the reflux temperature, and then decompressed to 6666.1 Pa or less at 100 ° C. for 2 hours to remove the condensed water, and heat cured in which 95% of the reactive hydroxyl groups were converted to dihydrobenzoxazine. A water-soluble resin was obtained.

[2] Example of synthesizing melamine-modified phenol resin To 94 parts of phenol, 29 parts of 41.5% formalin and 0.47 parts of triethylamine were added.
Allowed to react for hours. After adding 19 parts of melamine and further reacting for 1 hour, the temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was performed for 2 hours while maintaining the temperature. Next, the temperature was raised to 180 ° C. while removing water under normal pressure, and unreacted phenol was removed under reduced pressure to obtain a melamine-modified phenol resin having a softening point of 136 ° C. which is a reaction product of phenol and melamine. .

With respect to the resin having a dihydrooxazine ring synthesized as described above, a melamine-modified phenol resin, γ-glycidoxypropyltrimethoxysilane as a coupling agent, and 1-benzyl-2-methylimidazole as a curing accelerator are shown in Table 2. 50 parts by weight of aluminum hydroxide (average particle size: 3 μm) based on varnish (organic resin solids: 100 parts by weight) diluted with a mixed solvent of methyl ethyl ketone (MEK), 2-ethoxyphenol, and dimethylformamide (DMF). , strontium titanate powder (average particle size 1 [mu] m) were mixed to uniformly disperse added 150 parts by weight, thickness 0.1mm weight 104 g / m ² of glass fabric to the molding thickness 0.15 mm (resin content 73% ) To prepare a prepreg that was applied and dried. The four prepregs were stacked and heated and pressed under the conditions of 185 ° C., a pressure of 3 MPa and 120 minutes to obtain a laminated board. Table 1 shows the characteristics of the laminate.

Example 2 A prepreg was prepared in the same manner as in Example 1 except that the melamine-modified phenol resin in Example 1 was changed to phenol novolak (HP-850N manufactured by Hitachi Chemical Co., Ltd.). To obtain a laminate. Table 1 shows the characteristics of the laminate.

Example 3 Example 1 was repeated except that the aluminum hydroxide in Example 1 was changed to magnesium hydroxide (average particle size: 1 μm).
A prepreg was prepared, and a laminate was obtained using the prepreg. Table 1 shows the characteristics of the laminate.

Comparative Example 1 Bisphenol A type epoxy resin (Epoxy equivalent: 45)
Resin varnish (solid content 100) in which 0.6 equivalent of dicyandiamide and 0.3 part by weight of 1-benzyl-2-methylimidazole are added to 100 parts by weight of epoxy resin with respect to 0).
Parts by weight), 150 parts by weight of aluminum hydroxide and 150 parts by weight of strontium titanate powder (average particle size: 1 μm) are added and mixed so as to be uniformly dispersed, and have a thickness of 0.1 mm.
Glass cloth weighing 104 g / cm ² (WE11 manufactured by Nitto Boseki Co., Ltd.)
6E), a prepreg that was applied and dried so as to have a molding thickness of 0.15 mm (resin content 73%) was produced. Table 1 shows the characteristics of the laminate obtained by stacking four prepregs and heating and pressing them under the conditions of 185 ° C., a pressure of 3 MPa and a pressure of 120 minutes.

[0047]

[Table 2] * 1 Complies with UL-94. The board thickness is 0.15mm,
0.6 mm and 1.5 mm were tested. * 2 Evaluation was made on a 0.6 mm-thick plate except for the flame resistance. * 3 Heat resistance to moisture absorption solder: Test piece (50 mm × 50 mm single-sided half) after being held in a pressure cooker at 121 ° C. and 2130 hPa for 3 hours. The sample with copper, 3) was immersed in a solder bath heated to 260 ° C. for 30 seconds, and the occurrence of blistering and measling was visually observed. Each symbol in Table 1 represents three samples.
○: no change, Δ: occurrence of measling or bleeding, ×: occurrence of blistering. * 4 Conforms to JIS C6481. * 5 Measured by TMA (Thermomechanical Analizer) method.

Examples 1 to 3 using a compound having a dihydrobenzoxazine ring have higher flame retardancy than Comparative Example 1 using an epoxy resin. In particular, a polycondensation product of a phenol and a compound having a triazine ring and an aldehyde is used as a compound showing reactivity with a phenolic hydroxyl group generated by opening of the dihydrobenzoxazine ring and the dihydrobenzoxazine ring, and inorganic hydration is performed. By using aluminum hydroxide as a material, UL
It is possible to provide a high dielectric constant laminate having a flame retardancy of 94V-0.

[0049]

Industrial Applicability The resin composition of the present invention can provide a prepreg and a laminate having excellent flame retardancy and a high dielectric constant, as well as excellent properties.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Harumi Negishi 1500 Oji Ogawa, Shimodate City, Ibaraki Pref.Hitachi Kasei Kogyo Co., Ltd. AF27 AF32.

Claims (5)

[Claims] 1. A resin comprising (a) a resin having a dihydrobenzoxazine ring in a molecule, and (b) a resin comprising a compound having reactivity with a phenolic hydroxyl group formed by opening of a dihydrobenzoxazine ring and a dihydrobenzoxazine ring. A component comprising (c) a high dielectric constant inorganic powder and, if necessary, (d) at least one compound selected from inorganic hydrates, nitrogen-based compounds, and phosphorus-based compounds; A flame-retardant high dielectric constant resin composition having a content of 0.1% by weight or less based on the total amount of materials used. 2. A resin component comprising a compound having a reactivity with a phenolic hydroxyl group formed by opening a dihydrobenzoxazine ring and a dihydrobenzoxazine ring is formed by reacting a compound having a phenol and triazine ring with an aldehyde. The flame-retardant high dielectric constant resin composition according to claim 1, which is a polycondensate. 3. The flame-retardant high dielectric constant resin composition according to claim 1, wherein the inorganic hydrate is aluminum hydroxide. 4. A flame-retardant high dielectric constant prepreg obtained by impregnating a substrate with the flame-retardant high dielectric constant resin composition according to claim 1 and drying. 5. A flame-retardant high dielectric constant laminate obtained by heating and pressing the high dielectric constant prepreg according to claim 4.