JP4539835B2 - Resin composition and cured product - Google Patents

Description

  The present invention relates to a cyanate ester resin composition applied to a printed wiring board material for forming an electric circuit, and a cured product using the same.

  Cyanate ester resin has long been known as a thermosetting resin excellent in heat resistance and dielectric properties, and is a resin composition of a bisphenol A type cyanate ester resin and another thermosetting resin or thermoplastic resin. Is disclosed. These resin compositions have excellent electrical properties, mechanical properties, chemical resistance, adhesive properties, etc., and based on these technologies, in recent years, high-performance printed wiring for semiconductor plastic packages etc. Widely used for board materials. In parallel with these trends, resin compositions based on cyanate ester resins having other structures have been studied with the aim of further improving the properties.

  As examples of cyanate ester resins having other structures, there are many examples of novolac-type cyanate ester resins (see, for example, Patent Document 1), but novolak-type cyanate ester resins are insufficiently cured under normal curing conditions. The resulting cured product has problems such as high water absorption and dielectric constant. As a method for improving the novolak-type cyanate ester resin, a prepolymer with a bisphenol A-type cyanate ester resin has been disclosed (see, for example, Patent Document 2). In terms of improving the characteristics, it was still insufficient.

Japanese Patent Laid-Open No. 11-124433 JP 2000-191776 A

  The present invention relates to a resin composition intended to improve water absorption and dielectric constant in a novolac-type cyanate ester resin composition, and also provides a cured product using the same.

（式中のｎは1以上の整数であり、Ｒは水素またはアルキル基を示す）

好ましくは、ノボラック型シアン酸エステル(a)とトリフェニルメタン型シアン酸エステル(b)の重量配合比率が、98：2〜50：50である樹脂組成物であり、これら樹脂組成物を硬化してなる硬化物である。 As a result of intensive studies to solve the above problems, the present inventors have obtained a resin composition having improved water absorption and dielectric constant by using a specific trifunctional cyanate ester in combination with a novolak-type cyanate ester. And the present invention has been achieved. That is, the present invention is a resin composition containing a phenol novolac cyanate ester (a) represented by the general formula (1) and a triphenylmethane cyanate ester (b) represented by the formula (2). Yes,

(In the formula, n is an integer of 1 or more, and R represents hydrogen or an alkyl group)

Preferably, it is a resin composition in which the weight blending ratio of the novolak-type cyanate ester (a) and the triphenylmethane-type cyanate ester (b) is 98: 2 to 50:50, and these resin compositions are cured. It is a cured product.

  The cyanate ester resin composition obtained by the present invention is an improvement of the problems of the conventional novolac cyanate ester resin composition and has excellent water absorption and low dielectric constant. It is suitable for printed wiring board materials for forming circuits, and its industrial value is great.

  The novolak-type cyanate ester (a) used in the present invention is not particularly limited as long as it is a compound having a structural unit represented by the general formula (1). These novolak-type cyanate esters (a) are compounds obtained by reacting cyanogen halide with a novolak resin such as phenol novolak and cresol novolak, and are used singly or in combination of two or more. It is also possible. Specific examples of commercially available products of novolak cyanate ester (a) include Lonza's Primaset PT-15, PT-30, PT-60 (phenol novolac cyanate ester resin) and CT-90 (cresol). Novolak-type cyanate ester resin).

  The triphenylmethane cyanate ester (b) used in the present invention is a compound represented by the formula (2). This triphenylmethane cyanate ester (b) is a compound obtained by reacting tris (hydroxyphenyl) methane and cyanogen halide in an inert organic solvent in the presence of a base. In addition to the type cyanate ester (b) monomer, those containing oligomers and oligomers can also be used.

  Examples of the cyanogen halide used for the production of the triphenylmethane type cyanate ester (b) include cyanogen chloride and cyanogen bromide, with cyanogen chloride being particularly preferred. Examples of the base to be used include various amines, alkali metal hydroxides, alkaline earth metal hydroxides, alkali bicarbonates, alkali carbonates, alcoholates and the like, and tertiary amines are particularly preferable. Tertiary amines include trimethylamine, triethylamine, tripropylamine, diethylpropylamine, pyridine and the like, and triethylamine is particularly preferable. Examples of inert organic solvents that can be used include hydrocarbons, chlorinated hydrocarbons, nitrohydrocarbons, ketones, ethers, and more specifically, benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride. Chlorobenzene, nitrobenzene, nitromethane, acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ether, tetrahydrofuran, dioxane and the like. The reaction temperature is usually about -30 to 20 ° C, particularly preferably -20 to 0 ° C.

  The mixing ratio of the novolak cyanate ester (a) and the triphenylmethane cyanate ester (b) in the resin composition of the present invention is not particularly limited, but the novolak cyanate ester (a) and the triphenylmethane cyanate ester is not limited. The weight blending ratio of the ester (b) is preferably in the range of 98: 2 to 50:50. If the amount of triphenylmethane cyanate ester (b) is less than 2% or exceeds 50%, there is a tendency for more unreacted cyanate groups to remain, so the effect of improving curability decreases. The desired improvement effect may not be obtained.

  When the resin composition of the present invention is used as a printed wiring board material or the like, an organic solvent is used as necessary to lower the viscosity of the resin composition. As this organic solvent, a known organic solvent used for a printed wiring board material or the like is applicable. Examples of the organic solvent include acetone, methyl ethyl ketone, diethyl ketone, ethyl acetate, toluene, xylene, dimethylformamide, dimethyl sulfoxide, methylene chloride, chloroform and the like.

  In addition, known epoxy resins, maleimide compounds, polyphenylene ethers, polyimide resins and the like used for printed wiring board materials can be used in combination with the resin composition of the present invention. It is also possible to use a combination of more than one species as appropriate.

  The method for preparing the resin composition of the present invention is not particularly limited, but the novolac-type cyanate ester (a) and the triphenylmethane-type cyanate ester (b) may be used as they are or prepolymerized ones. It is also possible to use it. These prepolymers of cyanate esters are usually obtained by heating to about 50 to 200 ° C. in the presence or absence of a catalyst. Catalysts that can be used for prepolymerization include, for example, acids such as mineral acids and Lewis acids; salts such as tertiary amines, sodium alcoholate and sodium carbonate; active hydrogen-containing compounds such as bisphenol compounds and monophenol compounds . This prepolymer can be used as it is, or it can be used after being dissolved in a soluble organic solvent and blended with another resin as required. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; esters such as propylene glycol monomethyl ether acetate and the like.

  Although the resin composition of the present invention can be cured only by heating, it is preferably made into a cured product by using a known cyanate ester resin curing catalyst in combination with heating. Examples of the curing catalyst include organic metal salts such as zinc octylate, tin octylate and dibutyltin dimaleate; acetylacetone iron; chlorides such as aluminum chloride, tin chloride and zinc chloride; amines such as triethylenediamine and dimethylbenzylamine Imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; phenols such as phenol and catechol, and the like, and one or two or more are used as appropriate. The amount of the curing catalyst used is usually about 0.001 to 1.0 part by weight with respect to 100 parts by weight in total of the novolak type cyanate ester (a) and the triphenylmethane type cyanate ester (b).

  The cured product of the present invention can be obtained by heating and curing the resin composition of the present invention in the presence or absence of pressure. The curing temperature is usually about 150 to 350 ° C., and the curing time is usually about 30 minutes to 30 hours, whereby the cured product of the present invention is obtained.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. “Parts” represents parts by weight.
(Synthesis example) Synthesis of triphenylmethane cyanate ester Tris (4-hydroxyphenyl) -1,1,1-methane 0.17 mol (OH group equivalent) and triethylamine 0.57 mol were dissolved in 500 g of tetrahydrofuran to obtain a solution A. Obtained. Next, solution A was added dropwise over a period of 1.5 hours at −5 ° C. over a mixture of 0.67 mol of cyanogen chloride, 175 g of methylene chloride and 500 g of chloroform, stirred for 30 minutes, and then mixed with 0.08 mol of triethylamine and 15 g of chloroform. The solution was added dropwise and stirred for another 30 minutes to complete the reaction. After the reaction solution was filtered, the obtained filtrate was washed with 800 ml of 0.1N hydrochloric acid, washed with 800 ml of 2.5% saline four times, and finally washed with 800 ml of water. Sodium sulfate was added thereto to adsorb and remove moisture, and then evaporated at 50 ° C. to obtain yellow crude crystals. The obtained crude crystals were recrystallized with a mixed solvent of hexane and acetone. After filtration and washing with hexane, drying was performed under reduced pressure to obtain a triphenylmethane cyanate ester (hereinafter referred to as TRPCN) having a melting point of 98 ° C. measured by DSC.

(Examples 1 to 5, Comparative Examples 1 and 2)
In the blending ratios shown in Tables 1 and 2, various phenol novolac cyanates (Primaset PT-15 weight average molecular weight: 443, PT-30 weight average molecular weight: 615, PT-60 weight average molecular weight: 744, Lonza And TRPCN obtained in Synthesis Example 1 were mixed at 120 ° C., and zinc octylate (Nikka octix zinc 18%, manufactured by Nippon Kagaku Sangyo Co., Ltd.) was added as a methyl ethyl ketone solution having a solid content of 2%, followed by stirring and mixing. Thus, a resin composition was obtained. This resin composition was poured into an aluminum sheet mold preheated to 120 ° C., deaerated using a vacuum pump (5 Torr or less, 30 seconds), and then heated at 170 ° C. for 2 hours. And heated at 230 ° C. for 9 hours to obtain a cured product having a thickness of 1.6 mm. The physical property measurement results of the obtained cured product are shown in Tables 1 and 2.

(Measuring method)
1) Dielectric constant:
Average value measured three times by cavity resonator perturbation method using network analyzer HP8722ES (manufactured by Ajylene Technology) using a sample of size 100mm x 1mm x 1.6mm. (Measurement frequency: 10GHz)
2) Water absorption:
Using a sample of size 40mm x 40mm x 1.6mm, we measured twice the rate of weight increase after treatment for 12 hours at 121 ° C and 2 atm using a prescher cooker tester (PC-3 type manufactured by Hirayama Seisakusho). Average value.

Claims (3)

A resin composition comprising a novolak cyanate ester (a) represented by the general formula (1) and a triphenylmethane cyanate ester (b) represented by the formula (2).

(In the formula, n is an integer of 1 or more, and R represents hydrogen or an alkyl group)

  2. The resin composition according to claim 1, wherein the weight blending ratio of the novolak cyanate ester (a) and the triphenylmethane cyanate ester (b) is 98: 2 to 50:50.   A cured product obtained by curing the resin composition according to claim 1.