JPH111604A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition which can give cured products not suffering from oxidation deterioration at high temperatures in the presence of oxygen and exhibits improved reliability of insulation of wirings when used for laminated and wiring boards or as a sealing material for semiconductors by adding a compound having a t-butylsubstituted phenol ring to a composition containing a heat-resistant resin having dihydrobenzoxazine rings. SOLUTION: The resin having dihydrobenzoxazine rings can be synthesized from a compound having a phenolic hydroxyl group, formalin and a primary amine according to the formula. The phenolic hydroxyl containing compound as a starting material is exemplified by a phenolic resin such as a resol resin or a bisphenol compound. The primary amine used is exemplified by methylamine or aniline and is selected according to the use. The compound having a t-butylsubstituted phenol ring is exemplified by 4,4'-butylidenebis(6-t- butyl3-methylphenol) and is used in an amount of desirably 0.05-1 pt.wt. based on the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention improves the thermal stability of a cured product by adding a compound having a t-butyl group-substituted phenol ring to a resin composition containing a resin having a dihydrobenzoxazine ring. About technology. It is effective for improving the characteristics of composite molding materials, laminates, wiring boards, semiconductor devices, and the like using these.

[0002]

2. Description of the Related Art Conventionally, as a thermosetting resin system having a dihydrobenzoxazine ring, JP-B-49-47378 is known.
JP, JP-A-2-69567, JP-A-4-22
It is known that a resin having a dihydrobenzoxazine ring as disclosed in JP-A-7922 is used alone or in combination with an epoxy resin or the like.

[0003]

Since these resin cured products have a phenol nucleus in the resin, when heated in the presence of oxygen, the phenol nucleus is oxidized, and the strength, electric characteristics, etc. are reduced. May be invited. The present invention provides a thermosetting resin composition free from such a problem.

[0004]

That is, the resin composition of the present invention is obtained by adding a compound having a phenol ring substituted with a t-butyl group to a resin composition containing a resin having a dihydrobenzoxazine ring. It is. When these cured products are exposed to a high temperature in the presence of oxygen, phenolic hydroxyl groups derived from the cured resin having a dihydrobenzoxazine ring can be suppressed from being oxidized and degraded. Further, the molding material according to the present composition is a laminate,
It can be used for a wiring board or a semiconductor sealing material to improve the insulation reliability of wiring under high temperature and high humidity.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-resistant resin having a dihydrobenzoxazine ring used in the present resin composition can be synthesized from the corresponding compound having a phenolic hydroxyl group, formalin and a primary amine according to the following formula 1. As shown in U.S. Pat. No. 5,152,939, this resin causes a ring-opening polymerization reaction by heating to form a phenolic hydroxyl group without generating volatile components, and forms a crosslinked structure having excellent properties.

[0006]

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The characteristics of these resins are described in
As described in JP-A-188364, crosslinking is cured by a ring-opening reaction, so that voids hardly remain in a cured product. The cured product has characteristics such as low water absorption, relatively high glass transition temperature, high strength, and excellent flame retardancy. Examples of the compound having a phenolic hydroxyl group include phenol novolak resins, resol resins, phenol-modified xylene resins, alkylphenol resins, melamine phenol resins, phenol resins such as polybutadiene-modified phenol resins, or bisphenol compounds, biphenol compounds, trisphenol compounds, and tetraphenols. Compounds can be mentioned. Specific examples of the primary amine include methylamine, cyclohexylamine, aniline, and substituted aniline. When an aliphatic amine is used, the obtained thermosetting resin cures quickly, but the heat resistance of the cured product is slightly inferior, and when an aromatic amine such as aniline is used, the heat resistance of the obtained cured product is improved. However, the curability becomes slow. The resin in the present invention is, for example, a mixture of a compound having a hydroxyl group and a primary amine at 70 ° C.
70 to 110 by adding to the aldehyde heated above.
C., preferably at 90 to 100.degree. C. for 20 to 120 minutes, followed by drying under reduced pressure at a temperature of 120.degree. C. or less.

The compound having a phenol ring substituted with a t-butyl group used in the present invention includes, for example, 4,4'-butylidenebis- (6-t-butyl-3-methylphenol), dibutylhydroxytoluene, 2,2 '-Methylenebis- (4-methyl-6-t-butylphenol),
2,2'-methylenebis- (4-ethyl-6-t-butylphenol), 1,1,3-tris (2-methyl-4
-Hydroxy-5-t-butylphenyl) butane, 2,
6-di-t-butyl-4-ethylphenol, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, triethylene glycol bis [3- (3-t -Butyl-4-hydroxy-5-methylphenyl) propionate] and tris- (3,5-di-t-butyl-4-hydroxybenzyl) -cyanurate. When these compounds are used in the present resin system, the cured product of the resin having a dihydrobenzoxazine ring can significantly reduce the oxidative deterioration rate when left at high temperature in the presence of oxygen.
For this reason, the cured product reliability under the same conditions is significantly improved,
When these cured products were used for wiring board substrates and semiconductor encapsulating materials, it was found that insulation resistance under high temperature and high humidity was prevented. Generally, no effective antioxidant has been found when a phenolic structure such as the present resin system is present in the cured product. It is desirable to use these compounds in an amount of 0.05 to 1.0% (by weight) based on the resin composition to be used. If it is 0.05% or less, the effect is not sufficient, and if it is 1.0% or more, other physical properties such as heat resistance are reduced. In the present invention, an effective effect can be expected with such a small amount of addition.

In the present invention, a compound that promotes the ring opening reaction of the dihydrobenzoxazine ring can be used. These compounds include amine compounds such as benzylmethylamine, imidazole and its derivatives, phosphorus-containing compounds, boron trifluoride amine complex, dicyandiamide and its derivatives, compounds having a phenolic hydroxyl group, that is, phenol novolak resins, resole resins or Modified phenol resins such as xylene-modified phenol resins and xylylene-modified resins, and low-molecular phenol compounds such as bisphenol A can be mentioned. The compounding ratio of the heat-resistant resin having a dihydrobenzoxazine ring and the compound capable of promoting the ring-opening reaction of the dihydrobenzoxazine ring is preferably in the range of 97/3 to 50/50 by weight. When the compound having reactivity with a dihydrobenzoxazine ring or a phenolic hydroxyl group is 3 parts or less, the promotion of the ring opening reaction is not remarkable, and when it is 50 parts or more, a heat-resistant resin having a dihydrobenzoxazine ring is used. The characteristics such as low water absorption, which are characteristics of the above, are impaired.

As the epoxy resin, bisphenol epoxy resin, novolak epoxy resin, cresol novolak epoxy resin, polyphenol epoxy resin, polyglycol epoxy resin, alicyclic epoxy resin, halogenated bisphenol A, halogenated bisphenol The glycidyl ether of F, especially tetrabromobisphenol A or tetrabromobisphenol F, and the glycidyl ether of brominated novolak can be used in combination. By these modifications, it is possible to obtain a cured resin having a wide range of resin properties. For example, when a novolak type epoxy resin or a cresol novolak type epoxy resin is used, the crosslink density can be improved, and when an alicyclic epoxy resin is used, the tracking resistance can be improved. it can. As a curing agent for the epoxy resin, an amine compound such as benzylmethylamine, imidazole and its derivatives, a phosphorus compound, a boron trifluoride amine complex, dicyandiamide and its derivatives can be used as necessary. Furthermore, in the resin composition of the present invention, ordinary inorganic and organic fillers and reinforcing fibers can be used as a reinforcing material.
For example, staple fiber, yarn, cotton cloth, glass cloth, glass mat, glass fiber, carbon fiber, quartz fiber,
Flame-retardant synthetic fibers, silica powder, calcium carbonate, aluminum hydroxide, magnesium hydroxide and the like. If these fillers are treated in advance with a coupling agent, the interfacial adhesive with the resin can be improved. There is no particular limitation on the method, order, etc., for mixing these resins and curing agents. At this time, adding a coupling agent is also effective in improving the interfacial adhesion between the filler and the resin.
Copper-clad laminates, prepregs using these resin compositions,
The method for producing the sealing material and the molding material is not particularly limited. Usually, these resin compositions are dissolved by using an organic solvent, and then applied to a substrate and dried. The prepreg manufactured in this way is
A copper-clad laminate can be manufactured by pressing and forming a copper foil on both sides thereof. In addition, a sealing material, a molding material, and the like can be manufactured by melt-kneading the resin composition and the filler.

[0011]

EXAMPLES Specific examples of the present invention will be shown below, but the present invention is not limited to these. Synthesis of dihydrobenzoxazine resin Two kinds of resins were synthesized by the following method. (Resin A) (1) Synthesis of phenol novolak resin 1.9 kg of phenol, formalin (37% aqueous solution)
1.0 kg and 4 g of oxalic acid were charged into a 5-liter flask and reacted at a reflux temperature for 6 hours. Next, 66 inside
The pressure was reduced to 66.1 Pa or less to remove unreacted phenol and water. The obtained resin has a softening point of 84 ° C (ring and ball method),
The ratio was 3 to polynuclear / binuclear 82/18 (peak area ratio by gel permeation chromatography). (2) Introduction of dihydrobenzoxazine ring 1.70 phenol novolak resin synthesized as above
kg (equivalent to 16 mol of hydroxyl groups) to aniline 1.
The mixture was mixed with 49 kg (corresponding to 16 mol) and 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. At the end of the addition, maintain the reflux temperature for 30 minutes, and then reduce the pressure of water to 6666.1 Pa or less at 100 ° C. for 2 hours to remove the condensed water, and heat cure in which 75% of the reactive hydroxyl groups have been converted to dihydrobenzoxazine. An acidic compound was obtained. (Resin B) A thermosetting compound having a dihydrobenzoxazine ring introduced therein was obtained in the same manner as in Resin A, except that a mixture of 0.93 kg of aniline and 0.64 kg of toluidine was used instead of aniline. The obtained thermosetting compound was a phenol novolak resin in which a dihydrobenzoxazine ring was introduced into 71% of the reactive hydroxyl groups. Examples of the compound containing a phenol ring substituted with a t-butyl group include Yoshinox GSY manufactured by Yoshitomi Pharmaceutical Co., Ltd.
-314, BB, 930 was used. Further, as a phenol novolak resin used as a curing agent used for accelerating the curing of the resin having a dihydrobenzoxazine ring, HP-850N manufactured by Hitachi Chemical Co., Ltd. was used. Furthermore, as a flame retardant, Toto Kasei Kogyo Co., Ltd.
The brominated epoxy resin YDB-400T manufactured was used.

Examples 1 to 6 and Comparative Examples 1 to 4 A resin composition having the composition shown in Table 1 was prepared.
Cured for minutes. The cured product was pulverized and passed through a 150-mesh sieve, and the thermal stability at 250 ° C. was evaluated by TGA in which standard air was flowed at a flow rate of 30 to 40 ml / min. In addition, glass transition temperature by TMA, bending strength,
The water absorption was also measured. The results are shown in Tables 2 and 3. ,

Examples 7 and 8 and Comparative Example 5 The resin compositions shown in Examples 1 and 2 and Comparative Example 1 were dissolved in MEK to prepare 55% varnish. This varnish was coated on a glass cloth to prepare a coated cloth and a prepreg. Coating conditions: 140 ° C / 1.5 minutes + 170 ° C / 2 minutes + 175 ° C
/ 2 minutes + 150 ° C / 1.5 minutes. Coated cloth 8 obtained
A copper foil (18 μm) was placed on both sides of the sheet, and the pressure was 30 kg /
cm, from room temperature to 185 ° C for 30 minutes,
The laminate was heated and pressed at 5 ° C. for 60 minutes to obtain a copper-clad laminate. The obtained copper-clad laminate is subjected to water absorption treatment for a predetermined time by a pre-sher cooker method, and the laminate is left in an atmosphere at a temperature of 210 ° C. for a time during which swelling occurs due to immersion in a solder bath and bending The time at which the strength halved was measured. Table 4 shows the results.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

As is apparent from the above description, according to the present invention, a compound having a t-butyl-substituted phenol ring in its structure is added to a resin composition containing a resin containing a dihydrobenzoxazine ring. Thereby, the thermal stability when the cured product was left at a high temperature in the presence of oxygen could be improved. As a result, when a cured product of the present resin composition is used as a wiring board or a semiconductor encapsulating material, its reliability can be significantly improved.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideo Nagase 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Plant of Hitachi Chemical Co., Ltd. (72) Shinichi Kamoshida 1500 Ogawa Ogawa Shimodate City Ibaraki Prefecture Hitachi Chemical Co., Ltd In the Shimodate Plant (72) Inventor Minoru Kakitani 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Plant, Hitachi Chemical Co., Ltd.

Claims (5)

[Claims] 1. A thermosetting resin composition comprising a compound having a t-butyl group-substituted phenol ring added to a resin composition containing at least one resin having a dihydrobenzoxazine ring. 2. The thermosetting resin composition according to claim 1, wherein the compound has two or more phenol rings substituted with a t-butyl group. 3. A cured product obtained by curing the resin composition according to claim 1 or 2. 4. A composite molding material comprising the resin composition according to claim 1 and a reinforcing material. 5. A molded product obtained by molding the composite molding material according to claim 4.