JPH10251380A - Thermoset resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoset resin composition capable of being formed into the flame retardant one at a low cost, further capable of readily improving characteristics because various epoxy resin can be used, and useful for a laminated plate, a circuit board, etc., by formulating a specific thermoset resin with a halogenated phenol and the epoxy resin. SOLUTION: This thermoset resin composition consists essentially of (A) a thermoset resin having a dihydrobenzoxazine ring [preferably, the one having (A1 ) a structure unit of formula I and (A2 ) a structure unit of formula II (R is methyl, phenyl, etc.) in the molar ratio A1 /A2 of (1/0.25) to (1/9) and further having (m) and (n) which are each not less than one and satisfy the formula 10>=(m)+(n)>=2], (B) a halogenated phenol compound, and (C) an epoxy resin [e.g. a (cresol) novolak type epoxy resin for increasing a crosslinking density, and an alicyclic epoxy resin for improving tracking resistance and flexibility].

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 having a dihydrobenzoxazine ring which is suitably used as a raw material for producing prepregs, metal-clad laminates, sealing materials, wiring boards, etc., and cured products thereof. And a composite molding material containing the thermosetting resin, and a laminate and a wiring board using the same.

[0002]

2. Description of the Related Art It is known that a thermosetting resin having a dihydrobenzoxazine ring gives a cured product excellent in low water absorption, heat resistance and mechanical strength. As a method of making this thermosetting resin flame-retardant, methods described in JP-A-2-69567 and JP-A-4-227922 are known, and the former uses an inorganic phosphorus compound and an inorganic filler. The latter uses a halogenated epoxy resin to achieve flame retardancy.

[0003] However, in the former, it is recognized that the electrical properties of the cured product are reduced by the ionic component of the inorganic phosphorus compound. In addition, when an inorganic filler is used, there is a problem in electrolytic corrosion due to a large amount of ionic impurities, and there is a limitation in use because a synthetic inorganic filler is expensive. In addition, when an inorganic filler is used, the cured product loses flexibility, causing a problem in adhesiveness to a metal, and a problem in drillability when used as a wiring board. In addition, when preparing a prepreg by impregnating a resin varnish into a glass cloth, there is a problem that when an inorganic filler is used, it is necessary to pay attention to the impregnating property of the varnish and sedimentation of the inorganic filler during coating. .

The latter is expensive because it uses a halogenated epoxy resin, and because there are few types of commercially available resins, it uses halogenated epoxy resins having various epoxy resin skeletons and different properties. There are limitations.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to reduce the cost of a resin composition of a thermosetting resin having a dihydrobenzoxazine ring in comparison with the case where a halogenated epoxy resin is used alone. It is an object of the present invention to provide a thermosetting resin composition which can be made flame-retardant, and which can use epoxy resins having various skeletons, so that the properties can be easily improved by modifying the resin. I do.

The present invention also relates to a cured product of the thermosetting resin composition, a composite molding material containing the thermosetting resin, and a laminate and a wiring board using the same.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that a halogenated phenol compound and an epoxy resin are mixed with a thermosetting resin having a dihydrobenzoxazine ring. As a result, flame retardancy can be achieved at a lower cost than when a halogenated epoxy resin is used alone. In addition, since epoxy resins having various skeletons can be used, the properties are improved by modifying the resin. And found that the present invention was completed based on this finding.

That is, the present invention provides a thermosetting resin composition comprising, as essential components, a thermosetting resin having at least one dihydrobenzoxazine ring, a halogenated phenol compound and an epoxy resin. Things.

The thermosetting resin composition of the present invention can be manufactured at a lower cost than when a halogenated epoxy resin is used, and the type of epoxy resin used can be easily changed. It is possible to improve the properties of the cured resin as compared with the case where a halogenated epoxy resin is used. 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, tracking resistance can be improved. It is also possible to improve flexibility.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thermosetting resin having a dihydrobenzoxazine ring used in the thermosetting resin composition of the present invention has a dihydrobenzoxazine ring, and is obtained by a ring-opening polymerization reaction of the dihydrobenzoxazine ring. There is no particular limitation as long as it is a resin that cures. In particular,
For example, as shown in the following reaction formula, it can be synthesized from a compound having a phenolic hydroxyl group, a primary amine and formaldehyde.

[0011]

Embedded image (R in the formula is a methyl group, a cyclohexyl group, a phenyl group, or a phenyl group substituted with at least one alkyl group or alkoxyl group having 1 to 3 carbon atoms.) This resin is described in US Pat. No. 5,152,939. As shown in (1), a ring-opening polymerization reaction is caused by heating to form a phenolic hydroxyl group without generating volatile components, and to form a crosslinked structure having excellent properties. Further, as a feature of this resin, as shown in JP-A-7-188364, since the resin is crosslinked and cured by a ring opening reaction, voids hardly remain in the cured product, the cured product has a low water absorption,
It has relatively high glass transition temperature, high strength, and excellent flame retardancy.

The resin is prepared by adding a mixture of a compound having a phenolic hydroxyl group and a primary amine to formaldehyde such as formalin at 70 to 110 ° C., preferably at 70 to 110 ° C., as shown in the above reaction formula. 90-100 ° C
For 20 to 120 minutes, and then dried under reduced pressure at a temperature of 120 ° C. or lower.

Examples of the compound having a phenolic hydroxyl group include phenol novolak resins, resole resins, phenol-modified xylene resins, alkylphenol resins, melamine phenol resins, phenol resins such as polybutadiene-modified phenol resins, bis (2-hydroxyphenyl) methane, bis (4-hydroxyphenyl) methane,
4,4'-dihydroxydiphenyl sulfone, 1,1-
Bis (4-hydroxyphenyl) ethane, p, p'-isopropylidenebiphenol (bisphenol A), tetrafluorobisphenol A, 2,2-bis [4-
Bisphenol compounds such as (4'-hydroxyphenoxy) phenyl] propane, biphenol compounds such as 4,4'-biphenol, tris (4-hydroxyphenyl) methane, 1,1,1-tris (4-hydroxyphenyl) ethane and the like And a trisphenol compound and a tetraphenol compound. These are not particularly limited, but those in which the ortho position of the hydroxyl group serving as a crosslinking point is unsubstituted are desirable from the viewpoint of curing properties.

Specific examples of the primary amine include methylamine, cyclohexylamine, substituted anilines such as aniline, toluidine and anisidine. When it is an aliphatic amine, the obtained thermosetting resin cures quickly but has poor heat resistance. If it is an aromatic amine like aniline,
The cured product obtained by curing the obtained thermosetting resin has good heat resistance, but cures slowly.

Among the thermosetting resins having a dihydrobenzoxazine ring, preferably, the structural unit (A) represented by the following formula (A) and the structural unit represented by the following formula (B) in one molecule (B), wherein each structural unit is bonded directly or via an organic group, the molar ratio of (A) / (B) is 1 / 0.25 to 1/9, and 1 molecule When the number of structural units (A) is m and the number of structural units (B) is n,
A thermosetting resin having m ≧ 1, n ≧ 1 and 10 ≧ m + n ≧ 2 is used.

[0016]

Embedded image (Wherein R is a methyl group, a cyclohexyl group, a phenyl group or a phenyl group substituted with at least one alkyl group or alkoxyl group having 1 to 3 carbon atoms,
Hydrogen in the aromatic ring of (A) and (B), except for one of the ortho positions of the hydroxyl group of (A), may be substituted with an alkyl group or alkoxyl group having 1 to 3 carbon atoms or a halogen atom. M and n are within the above ranges, and the structural units (A) and (B)
If the space is previously bound by a stable bond via a group having an appropriate chain length, the properties of the cured product will be good.

The structural unit (A) and the structural unit (B) are bonded directly or via an organic group. Examples of the organic group include an alkylene group and a divalent aromatic group. Examples of the alkylene group include an alkylene group having 5 or more carbon atoms,-
And an alkylidene group represented by CR'H- (wherein R 'is a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a phenyl group or a substituted phenyl group). Examples of the substituent of the substituted phenyl group include a methyl group, a methoxy group, and a carboxyl group. Further, examples of the divalent aromatic group include a phenylene group, a xylylene group, and a tolylene group. Two or more of the above organic groups may be inserted between each structural unit.

The thermosetting resin used in the present invention comprises:
The molar ratio of (A) / (B) is preferably 1 / 0.25 to
1/9, more preferably 1 / 0.67 to 1/9.
Outside this range, curability, mechanical strength, and heat resistance may decrease.

Examples of the halogenated phenol compound used in the present invention include tetrachlorobisphenol A, tetrabromobisphenol A and the like. Examples of the epoxy resin include a bisphenol-based epoxy resin, a novolak-based epoxy resin, a cresol novolak-based epoxy resin, a polyphenol-based epoxy resin, a polyglycol-type epoxy resin, and an alicyclic epoxy resin.

The mixing ratio of the epoxy resin is preferably 5 to 100 parts by weight based on 100 parts by weight of the thermosetting resin having a dihydrobenzoxazine ring.

The halogenated phenol compound is preferably blended so that the hydroxyl equivalent of the halogenated phenol compound is 0.5 to 2.0 equivalents to the epoxy equivalent of the epoxy resin.

The thermosetting resin composition of the present invention has a compound capable of accelerating the ring-opening reaction of the dihydrobenzoxazine ring and a compound capable of accelerating the reaction between the epoxy group and the hydroxyl group formed by opening the dihydrobenzoxazine ring. A conventionally known catalyst for an epoxy resin can be blended.

Examples of the compound capable of promoting the ring opening of the dihydrobenzoxazine ring include a compound having a phenolic hydroxyl group and a primary amine. Examples of the compound having a phenolic hydroxyl group include modified phenol resins such as a phenol novolak resin, a resole resin, a xylene-modified phenol resin, and a xylylene-modified phenol resin.

The compounding ratio of the thermosetting resin having a dihydrobenzoxazine ring to the compound capable of promoting the ring opening reaction of the dihydrobenzoxazine ring is determined by the total amount of the thermosetting resin having a dihydrobenzoxazine ring and the compound. It is preferable to mix 3 to 50 parts by weight of a compound capable of promoting the ring-opening reaction of the dihydrobenzoxazine ring with 100 parts by weight. When the amount is less than 3 parts by weight, the promotion of the ring opening reaction is not remarkable, and when the amount exceeds 50 parts by weight, characteristics such as water absorption, which are characteristics of the thermosetting resin having a dihydrobenzoxazine ring, are impaired.

Examples of catalysts for epoxy resins include amine compounds such as benzylmethylamine, imidazole and its derivatives, phosphorus compounds, boron trifluoride amine complex, dicyandiamide and the like.

The mixing ratio of the epoxy resin catalyst is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

A compound capable of accelerating the ring opening reaction of the dihydrobenzoxazine ring and an epoxy resin catalyst can be used in combination.

Further, the thermosetting resin composition of the present invention may be compounded with ordinary reinforcing materials such as inorganic fillers, organic fillers, and fiber reinforcing materials. These may be used alone or as a mixture of two or more.

Examples of the organic filler include cotton floc, α-cellulose, pulp, wood flour and the like. As the inorganic filler, zircon powder, quartz glass powder, talc powder,
Examples include calcium carbonate powder, magnesium hydroxide powder, magnesia powder, calcium silicate powder, silica powder, zeolite, clay, and mica. Examples of the fiber reinforcing material include staple fiber, thread, cotton cloth, glass cloth, glass nonwoven fabric, glass fiber, carbon fiber, quartz fiber, organic fiber nonwoven fabric, and paper. The mixing ratio of these reinforcing agents is based on 100 parts by weight of the thermosetting resin.
Preferably it is 10 to 300 parts by weight.

Further, a releasing agent, a coloring agent, and the like can be added to the above composition, if necessary.

A composite molding material containing an inorganic filler and a fiber reinforcing material as essential components has excellent flame retardancy.

A laminate obtained by laminating a composite molding material comprising the above thermosetting resin composition, wherein the fiber reinforcing material is glass cloth, glass nonwoven fabric, organic fiber cloth, organic fiber nonwoven fabric or paper, A wiring board in which a wiring pattern is provided inside or on a surface of a substrate containing a cured material of a thermosetting resin composition as a matrix and containing an inorganic filler and a fiber reinforcing material is also excellent in flame retardancy.

The method and order of mixing the thermosetting resin composition having a dihydrobenzoxazine ring are not particularly limited.

The method of impregnating the substrate with these resin compositions is also not particularly limited, but usually, these resin compositions are made into a solution by using an organic solvent, and then applied to the substrate and dried. The prepregs obtained in this manner are overlapped, copper foil is overlapped on both sides of the prepregs, and pressed to produce a copper-clad laminate.

The copper-clad laminate thus manufactured is
The cost can be reduced as compared with the case where a halogenated epoxy resin is used as a flame retardant, and epoxy resins having various skeletons can be used, so that the characteristics can be easily improved.

The thermosetting resin composition of the present invention is kneaded with a heating roll or the like, and thereafter, at 180 to 220 ° C. and a molding pressure of 2
Cured by compression molding or transfer molding at 0 to 70 kgf / cm ² for 3 to 10 minutes to obtain a cured product having good mechanical properties and low hygroscopicity utilizing the properties of the thermosetting resin having a dihydrobenzoxazine ring. be able to.

The cured product is further heated at 180 to 220 ° C.
By post-curing for 5 to 120 minutes, a cured product having better properties can be obtained.

[0038]

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.

A thermosetting resin having three types of dihydrobenzoxazine rings was 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. Continue with 6 inside
The pressure was reduced to 666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 84 ° C. (ring and ball method) and a 3 to polynuclear / binuclear ratio of 82/18 (peak area ratio by gel permeation chromatography).

(2) Introduction of dihydrobenzoxazine ring 1.70 phenol novolak resin synthesized as described above
kg (equivalent to 16 mol of hydroxyl groups) to aniline 1.
It was mixed with 49 kg (corresponding to 16 mol) and stirred at 80 ° C. for 5 hours to prepare a uniform mixed solution. 1.62 kg of formalin was charged into a 5 liter flask and heated to 90 ° C., and a phenol novolak resin / aniline mixed solution was gradually added thereto over 30 minutes. 30 after completion of addition
For 2 minutes at reflux temperature, then at 100 ° C. for 2 hours 66
The condensation water was removed by reducing the pressure to 66.1 Pa or less to obtain a thermosetting resin in which 75% of the hydroxyl groups were converted to dihydrobenzoxazine. [Resin B] In the synthesis of [Resin A], a thermosetting resin having a dihydrobenzoxazine ring introduced was prepared in the same manner except that a mixture of 0.70 kg of aniline and 0.27 kg of toluidine was used instead of aniline. Obtained. The resulting thermosetting resin had a dihydrobenzoxazine ring introduced into 71% of the reactive hydroxyl groups of the phenol novolak resin.

Examples 1 to 3 and Comparative Examples 1 to 3 Varnishes having a concentration of 65% by weight were prepared from the resin compositions having the compositions shown in Table 1 using methyl ethyl ketone as a solvent.

This varnish was applied to a glass cloth. The coating conditions (coating temperature, coating time) are 1.5 at 140 ° C.
Minutes, 170 ° C. for 2 minutes, 175 ° C. for 2 minutes, and 150 ° C. for 1 minute. Placing copper foil on both sides of the obtained 8 coated cloths,
At a pressure of 30 kg / cm ² , the temperature was raised from room temperature to 185 ° C. over 30 minutes, and heated and pressed at 185 ° C. for 30 minutes to obtain a copper-clad laminate.

The obtained copper-clad laminate was subjected to a water absorption treatment for a predetermined time by a pressure cooker method, and then immersed in a solder bath to measure the time required for blistering to evaluate the moisture and heat resistance.

Further, using TMA, the glass transition temperature, U
A flame retardancy test and a tracking resistance test based on the L test method were performed.

The water absorption was measured after the PCT was treated for 3 hours.

[0046]

[Table 1] HP-850N: manufactured by Hitachi Chemical Co., Ltd., phenol novolak resin TBA: tetrabromobisphenol A ESCN195-3: manufactured by Sumitomo Chemical Co., Ltd., cresol novolak type epoxy resin AK-601: manufactured by Nippon Kayaku Co., Ltd. Alicyclic epoxy resin YDB-400T: Bisphenol A-based brominated epoxy resin

[0047]

[Table 2]

[0048]

The thermosetting resin composition containing the thermosetting resin having a dihydrobenzoxazine ring of the present invention, the composite molding material, the laminate and the wiring board have good mechanical properties, low moisture absorption and flame retardancy. It has. In addition, compared to a case where a halogenated epoxy resin is used alone as a flame retardant, flame retardancy can be achieved at a lower cost, and epoxy resins having various skeletons can be used, so that properties due to resin modification can be obtained. Is easy to improve.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08K 7/02 C08K 7/02 C08L 63/00 C08L 63/00 C (72) Inventor Yoshinori Sato 1500 Ogawa Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Inside Shimodate Plant (72) Inventor Shinichi Kamoshida 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside Shimodate Plant Hitachi Chemical Co., Ltd. (72) Inventor Minoru Kakitani 1500 Oji Ogawa Shimodate City in Ibaraki Prefecture Shimodate Plant Hitachi Chemical (72) Inventor Shunichi Numata 1500 Ogawa, Shimodate-shi, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd.

Claims (6)

[Claims] 1. A thermosetting resin composition comprising, as essential components, a thermosetting resin having at least one dihydrobenzoxazine ring, a halogenated phenol compound and an epoxy resin. 2. The thermosetting resin composition according to claim 1, comprising a thermosetting resin having at least one dihydrobenzoxazine ring, a halogenated phenol compound, an epoxy resin, and a compound having a phenolic hydroxyl group. 3. A cured product obtained by curing the thermosetting resin composition according to claim 1. 4. A composite molding material comprising the thermosetting resin composition according to claim 1 or 2, an inorganic filler and a fiber reinforcing material as essential components. 5. A laminate obtained by laminating and heating the composite molding material according to claim 4, wherein the fiber reinforcing material is glass cloth, glass nonwoven fabric, organic fiber cloth, organic fiber nonwoven fabric or paper. 6. A wiring board comprising a cured product of the thermosetting resin composition according to claim 1 or 2 as a matrix, and a wiring pattern provided inside or on a surface of the substrate containing an inorganic filler and a fiber reinforcing material.