JPH10259248A - Thermosetting composition and its hardened material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting composition capable of giving a hardened material having high heat resistance and high strength by compounding a thermosetting resin having a dihydrobenzoxazine ring with a thermosetting resin having a small amount of maleimide ring and utilizing a complex effect abstained by compounding them. SOLUTION: This composition contains (A) a thermosetting resin having a dihydrobenzoxazine ring and (B) a thermosetting resin having a meleimide ring as essential components, and a content of the component B is 3-30wt.% based on total amount of the components A and B. The component A can be synthesized from, e.g. a compound having a phenolic hydroxyl group where H is bonded to at least one site of ortho position, a primary amine and formaldehyde. Preferably, the component B is a bismaleimide, and especially, 4,4'- diphenylmethane bismaleimide, etc., is preferable. Furthermore, the composition can contain a novolak-type phenolic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD [0001] The present invention relates to a composition having excellent heat resistance,
Electronic components, laminated boards for printed wiring boards and printed wiring boards, semiconductor sealing materials, electronic materials such as semiconductor mounted modules, automobiles / vehicles, aircraft parts, building materials, thermosetting compositions used for machine tools, etc. Related to cured product.

[0002] The present invention also relates to a prepreg, a metal-clad laminate, and a printed wiring board using the above-mentioned thermosetting composition.

[0003]

2. Description of the Related Art A composition using a thermosetting resin is lightweight and
In addition to the characteristics of plastics such as low cost and mass productivity, it has excellent stability and reliability at high temperatures and is widely used in various industrial fields. However, thermosetting resins actually used commercially are limited to several types, such as phenolic resins, melamine resins, urea resins, epoxy resins, and the like, and the enhancement of these functions depends solely on the contribution of additives and fillers. I was As a means for enhancing the functionality of these resins themselves, it is known that compounding with a so-called super engineering plastic is effective. However, since the degree of the enhancement is substantially proportional to the amount of these additives, it is not sufficient. In order to improve the characteristics, a large amount of expensive super engineering plastics must be used, which loses commercial significance.

Recently, a novel thermosetting resin using a ring-opening polymerization reaction of a compound having a dihydrobenzoxazine ring has been found, and a cured product having high heat resistance, flame retardancy and high mechanical strength can be obtained. There are reports. For example, Journal of P
olymer Science: Part B: Polymer Physics, Vol. 32, 92
1-927 (1994) describes the properties of cured products of various bifunctional benzoxazine compounds, or JP-A-4-227922 discloses a resin composition of a dihydrobenzoxazine compound and an epoxy resin. 188364 and Journal of Applied Polymer Science, Vol. 58, 1
751-1760 (1995) discloses that the co-presence of a certain phenolic hydroxyl group in the molecule or as an additive can improve the curability of a dihydrobenzoxazine compound.

However, only a few studies on these dihydrobenzoxazine compounds have been reported, and the effect of complexing with other resin systems, particularly with high heat-resistant resins such as polyimide, has not been known so far.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a thermosetting resin having a dihydrobenzoxazine ring, which gives a cured product with high heat resistance and high strength by its compounding effect without using many expensive maleimide compounds. An object is to provide a thermosetting composition and a cured product thereof.

Another object of the present invention is to provide a prepreg, a metal foil-clad laminate, and a printed wiring board which are excellent in heat resistance and mechanical strength using the thermosetting composition.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a thermosetting resin having a small amount of a maleimide ring has been added to a thermosetting resin having a dihydrobenzoxazine ring. The inventor has found that the properties of the cured product of the thermosetting resin having a dihydrobenzoxazine ring are greatly improved by the addition, and the present invention has been completed based on this finding.

That is, the present invention contains a thermosetting resin having a dihydrobenzoxazine ring and a thermosetting resin having a maleimide ring as essential components, and the content ratio of the thermosetting resin having a maleimide ring is dihydrobenzoxazine ring. And a thermosetting resin having a content of 3 to 30% by weight based on the total amount of the thermosetting resin having the formula (1) and the thermosetting resin having a maleimide ring.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the thermosetting composition of the present invention, the content of the thermosetting resin having a maleimide ring is the total of the thermosetting resin having a dihydrobenzoxazine ring and the thermosetting resin having a maleimide ring. 3 to quantity
It needs to be 30% by weight. When the content ratio of the thermosetting resin having a maleimide ring is less than this range, the cured product characteristics of the thermosetting resin having a maleimide ring,
In particular, the effect of improving the glass transition temperature cannot be obtained. On the other hand, if it exceeds this range, the brittleness of the cured product peculiar to the imide resin becomes apparent, and the thermosetting having a dihydrobenzoxazine ring that can be manufactured from inexpensive raw materials The commercial advantage of the conductive resin is lost. A more preferable range of the content ratio of the thermosetting resin having a maleimide ring is 5 to 20% by weight.

The thermosetting resin having a dihydrobenzoxazine ring used in the present invention is not particularly limited as long as it has a dihydrobenzoxazine ring and is cured by a ring-opening polymerization reaction of the dihydrobenzoxazine ring. Specifically, for example, as shown in the following reaction formula, it can be synthesized from a compound having a phenolic hydroxyl group in which hydrogen is bonded to at least one of the ortho positions, a primary amine, and formaldehyde.

[0012]

Embedded image (R in the formula is an alkyl group having 1 to 6 carbon atoms, 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 heated. Causes a ring-opening polymerization reaction to form a phenolic hydroxyl group without generating volatile components, while forming a crosslinked structure having excellent properties. This cured product exhibits low water absorption, a relatively high glass transition temperature, and high strength, and is excellent in flame retardancy.

In order to synthesize this resin, a compound having a phenolic hydroxyl group in which hydrogen is bonded to at least one of the ortho positions, a primary amine and formaldehyde, and a primary amine in an amount of 0.1 mol per mole of the phenolic hydroxyl group. 5-
It is desirable to carry out the reaction using 1.0 mol and formaldehyde in a proportion of 2 mol or more per mol of primary amine. When the use ratio of the primary amine is as described above, a part of the phenolic hydroxyl group of the compound having a phenolic hydroxyl group remains unreacted, and the cured product properties such as curability and mechanical strength are improved.

The compound having a phenolic hydroxyl group having hydrogen bonded to at least one of the ortho positions, which is a raw material of a thermosetting resin having a dihydrobenzoxazine ring, includes phenols, polyfunctional phenols, bisphenols, Examples thereof include trisphenols such as 1,1,1-tris (4-hydroxyphenyl) ethane, and phenol resins. From the viewpoint of the properties of the cured product, hydrogen is bonded to at least one of the ortho positions in one molecule. It is desirable that the compound has two or more phenolic hydroxyl groups. Specifically, catechol, resorcinol, hydroquinone, and bisphenols such as bisphenol A, bisphenol S, bisphenol F, and hexafluorobisphenol A are exemplified as polyfunctional phenols. Examples of the phenol resin include a phenol novolak resin, a resol resin, a phenol-modified xylene resin, an alkylphenol resin, a melamine phenol resin, and a polybutadiene-modified phenol resin. These can be used alone or in combination of two or more.

The primary amine is methylamine,
Aliphatic amines such as butylamine and cyclohexylamine, and aromatic amines such as aniline, toluidine and anisidine can be used. These plural amines can be used in combination.

Formaldehyde can be used in any form as an aqueous formalin solution or as paraformaldehyde.

In a specific method for producing a thermosetting resin having a dihydrobenzoxazine ring, the above three raw materials are reacted by a procedure of gradually adding a primary amine to formaldehyde (having a phenolic hydroxyl group). The compound can be on either side of the amine or the aldehyde) and is kept at 70-120 ° C for 20 minutes to 24 hours after addition. At this time, a solvent can also be used. After the reaction, the product is isolated by a synthetic chemical technique such as extraction, and volatile components such as condensed water are removed by drying to obtain a desired thermosetting resin.

As the thermosetting resin having a maleimide ring, which is another essential component of the present invention, any of monomaleimides, bismaleimides and polymaleimides can be used. The characteristics vary greatly in brittleness and strength depending on the density of double bonds derived from maleic acid, which is a crosslinking point. In the present invention,
The balance between strength and toughness is best when bismaleimide is used, and it is particularly desirable to use 4,4'-diphenylmethanebismaleimide or 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane.

A maleimide compound, particularly a bismaleimide compound, itself is located in a special resin having high heat resistance, and is used only in fields requiring particularly high reliability such as a high-density multilayer printed wiring board. If such a high heat-resistant maleimide resin is compounded, the functionality can be improved even for general-purpose resins, but in general, different types of resin mixtures often show only intermediate characteristics between the two, and special micro-dispersion technology etc. Only when the phase separation structure and the interface structure can be controlled, an alloy is formed that utilizes only the advantages of different materials.
In the present invention, a non-linear relationship has been found between the amount of the maleimide compound added and the properties of the cured product, particularly the glass transition temperature,
It was confirmed that a large effect was obtained by adding a small amount of the maleimide compound. Also, with regard to the mechanical properties, there was a tendency that a decrease in the strain at break due to the addition of maleimide was small and only the strength was slightly improved. This is presumed to be due to the fact that aminomethylene chains, which are soft segments of the cured product, are selectively reinforced by maleimide crosslinking. It is also conceivable that the characteristic of the dihydrobenzoxazine ring, which cures slightly slower than other thermosetting resins, is synchronized with the polymerization rate of the maleimide compound, and that the crosslinked structure of both forms so-called IPN. As described above, the fact that a large effect can be obtained with a small addition amount in the introduction of an expensive maleimide compound is an advantage unique to a thermosetting resin having a dihydrobenzoxazine ring, and is the most important element of the present invention. is there.

The thermosetting composition of the present invention can contain a novolak type phenol resin. By blending the novolak type phenol resin, the curability is improved, and the physical properties of the cured product and the mechanical strength are also improved. The hydroxyl group in the novolak type phenol resin has the same function as the hydroxyl group remaining in the thermosetting resin having a dihydrobenzoxazine ring. The amount of the novolak type phenol resin is determined by the ratio of the total number of phenolic hydroxyl groups in the thermosetting resin having a dihydrobenzoxazine ring and the number of phenolic hydroxyl groups in the novolak type phenol resin (the number of phenolic hydroxyl groups / dihydrobenzoxazine ring). Number) is preferably 1.5 or less.
When the ratio is more than 1.5, the curability is remarkably improved, but the crosslink density of the cured product is significantly reduced, and good physical properties of the cured product, particularly, mechanical properties tend not to be obtained. Also,
When this ratio is between 0.2 and 1.2, more favorable results are obtained. When this ratio is less than 0.2, sufficient cured material properties can be obtained, but the main purpose of adding the novolak phenol resin, that is, the effect of improving curability tends to be reduced.

The thermosetting composition of the present invention may contain, if necessary, a filler, a reinforcing material, a flame retardant, a release agent, a coupling agent, a plasticizer, a curing aid, a coloring agent, in addition to the components described above. , A flexible agent, a solvent and the like. Further, as the thermosetting resin component, other than the above, an epoxy resin or the like can be mixed for adjusting viscosity, flowability and the like.

The thermosetting composition of the present invention is kneaded by a kneader, a heating roll or the like, and then kneaded by 150-220.
A cured product can be obtained by heating and pressing at 15 ° C. and a molding pressure of 20 to 100 kgf / cm ² for 15 minutes to 2 hours. Also,
This cured product is further heated at 180 to 220 ° C. for 30 minutes to 4 hours,
By post-curing, more excellent cured material properties can be obtained.

The thermosetting composition of the present invention is particularly excellent in heat resistance, and is used for electronic parts, laminated materials for printed wiring boards and printed wiring boards, semiconductor sealing materials, electronic materials such as semiconductor mounting modules, automobiles and vehicles, It is suitably used for aircraft parts, building members, machine tools and the like.

For example, the thermosetting composition of the present invention can be used as a molding material or a semiconductor encapsulating material as it is or by adding a filler, a releasing agent, a flame retardant, a coloring agent, a coupling agent and the like as needed. Can be used. Alternatively, a varnish may be prepared by adding a solvent or the like to the thermosetting composition of the present invention, impregnated into a substrate such as a glass cloth, and dried by heating to prepare a prepreg for a laminate. Further, by heating and pressing the prepreg together with the metal foil, a laminate for a printed wiring board is produced, and a circuit is further formed to produce a printed wiring board. The printed wiring board manufactured in this way has excellent heat resistance, excellent mechanical properties, etc., and is highly suitable for use as a semiconductor mounting substrate or the like.

[0025]

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.

For each property of the thermosetting resin and the composition shown below, the gel time is set to 0.1% for the resin or the composition.
3g 1m diameter on a hot plate maintained at 180 ° C
The mixture was stirred at a rate of once per second with an iron bar of m and the time until stringiness was eliminated was measured.
The glass transition temperature was measured according to SK 6911, and the glass transition temperature was determined from the inflection point of the thermal expansion curve (temperature rising rate: 10 ° C./min) by a thermomechanical property evaluation device (TMA).

Regarding the laminate properties, the glass transition temperature was determined by the TMA method described above, and the copper foil peel strength was determined according to JIS C648.
In accordance with 1, the water absorption was determined by the weight change of the entire surface of the etched plate after treatment at 120 ° C water vapor for 10 hours, and the flame retardancy was UL-
According to the standard 94, the corrosion resistance is 0.4mm in hole diameter and 0.3mm between walls.
It was determined by measuring the time required for insulation resistance to be 10 ⁸ Ω or less by applying a treatment of 50 V, 85 ° C. and 85% humidity between the through-holes of mm. Moisture and heat resistance was evaluated by treating the entire etched plate with steam at 120 ° C. and determining the time during which the plate was immersed in a solder bath at 260 ° C. for 20 seconds without any abnormality.

The molded article characteristics of the molding material are JIS K69.
11 and UL-94, and mold stains were visually evaluated.

Example 1 (1) Synthesis of thermosetting resin a having a dihydrobenzoxazine ring A phenol novolak (formaldehyde and phenol) synthesized by a conventional method using oxalic acid as a catalyst at a molar ratio of formaldehyde / phenol = 6/10. An average number of nuclei is 4, unreacted phenol is 0.1% by weight or less) 1.70 kg is dissolved in methyl ethyl ketone 0.89 kg, and 2.60 kg of 37% formalin is added thereto, followed by stirring and emulsification, and 1.49 kg of aniline is added thereto. The mixture was gradually added over 1 hour, and at the same time, the temperature was gradually raised to a reflux temperature (80 to 82 ° C) in 1 hour. The reflux temperature was maintained for 7 hours after the addition, and the solvent, moisture, and unreacted substances were dried and removed to obtain a red, transparent and uniform thermosetting resin a.

The NMR spectrum was used to determine the rate of formation of the formed dihydrobenzoxazine ring and the proportion of phenolic hydroxyl groups remaining without reacting. As a result, 75% of the phenolic hydroxyl groups of the raw material phenol novolak were determined.
Was cyclized to dihydrobenzoxazine, and it was found that 25% remained as hydroxyl groups. (2) Preparation of thermosetting composition 1.00 kg of the thermosetting resin a having a hydrobenzoxazine ring described above, 0.20 kg of a phenol novolak resin used as a raw material thereof, and 0.10 kg of 4,4'-diphenylmethane bismaleimide were used. After crushing and mixing, 150 ° C
The mixture was put into a heated twin-screw kneader and kneaded for 3 minutes. The temperature was lowered to 110 ° C., and the mixture was further kneaded for 5 minutes, cooled and pulverized to prepare a thermosetting composition. The ratio of the number of phenolic hydroxyl groups to the number of dihydrobenzoxazine rings in the composition is such that the number of phenolic hydroxyl groups / the number of dihydrobenzoxazine rings = 0.8, based on the amount of the phenol novolak resin blended. (3) Preparation of Cured Product The thermosetting composition prepared above was prepared using an internal size of 120 × 80 ×
Fill in a 4mm mold, 185 ° C, 50kgf / cm
^The mixture was heated and pressed at ² for 90 minutes to produce a plate-like cured product.

Examples 2 to 6 In the synthesis of the thermosetting resin a having a dihydrobenzoxazine ring of Example 1 (1), dihydrobenzoxazine was prepared in the same manner except that the mixing ratio of the raw materials was changed as shown in Table 1. Thermosetting resins b and c having a ring were synthesized. In the preparation of the thermosetting composition of Example 1 (2),
The thermosetting compositions of Examples 2 to 6 were prepared in the same manner except that the mixing ratio of the raw materials was changed as shown in Table 2.
A cured product was prepared in the same manner as in (3). Table 3 shows these characteristics.

Example 7 100 parts by weight of the thermosetting composition prepared in Example 1, 25 parts by weight of a bisphenol A type brominated epoxy resin (epoxy equivalent 400, bromine content 48% by weight), dicyandiamide 1 part by weight, silane 0.3 parts by weight of a coupling agent and 67 parts by weight of methyl ethyl ketone were mixed and dissolved to form a varnish. This is impregnated into a glass cloth having a thickness of 200 μm, and the solvent component is volatilized by a drier to obtain a resin component 42.
% By weight of prepreg was obtained.

Four prepregs are piled up, and 1
8μm electrolytic copper foil is laminated and sandwiched between stainless steel
The mixture was heated and pressed at 85 ° C. and 30 kgf / cm ² for 90 minutes to obtain a copper-clad laminate having a thickness of 0.8 mm. Table 4 shows the properties of the laminate.

Examples 8 to 10 Using the thermosetting compositions prepared in Examples 3 to 5, prepregs and copper-clad laminates were prepared in the same manner as in Example 7. Table 4 shows the properties of these laminates.

Example 11 100 parts by weight of the thermosetting composition prepared in Example 1, 130 parts by weight of glass fiber (fiber diameter 10 μm), 50 parts by weight of talc, 3 parts by weight of zinc stearate, silane coupling agent 1. 5 parts by weight and 1.5 parts by weight of carbon black were mixed, kneaded for 2 minutes with a biaxial heating roll heated to 150 ° C., and kneaded for 3 minutes while lowering the temperature to 120 ° C., and cooled and pulverized to prepare a molding material. . This is M-100A-TS manufactured by Meiki Seisakusho
Mold temperature 200 ° C, injection pressure 50k using a mold injection molding machine
The molding was performed under conditions of gf / cm ² and 10 minutes. Table 5 shows the characteristics of the molded product and the mold contamination after molding 50 kg of the molding material.
Shown in

Examples 12 to 14 Using the thermosetting compositions prepared in Examples 3 to 5, molding materials and molded products were produced in the same manner as in Example 11. Table 5 shows the characteristics of these molded articles and mold stains after molding 50 kg of the molding material.

Comparative Examples 1 to 5 In the same manner as in Example 1, a thermosetting composition and a cured product were prepared. The raw materials and formulations used in each comparative example are shown in Tables 1 and 2. Table 3 shows these characteristics. In Comparative Examples 4 and 5, bisphenol A type epoxy resin was used instead of the thermosetting resin having a dihydrobenzoxazine ring, and 4,4'-diaminodiphenylmethane was used as a curing agent thereof. Comparative Examples 2 and 3 are provided for clarifying the relationship between the ratio of the thermosetting resin having a dihydrobenzoxazine ring / the thermosetting resin having a maleimide ring and the properties of the cured product, It is not inconsistent with the present invention that better cured product properties are obtained than in the examples. FIG. 1 shows the ratio of the thermosetting resin having a dihydrobenzoxazine ring or the epoxy resin / thermosetting resin having a maleimide ring obtained in Examples 1 and 2 and Comparative Examples 1 to 5, and the glass transition of the cured product. This shows the relationship with temperature.

Comparative Examples 6 and 7 Using the thermosetting compositions produced in Comparative Examples 1 and 4, prepregs and copper-clad laminates were produced in the same manner as in Example 7. Table 4 shows the properties of these laminates.

Comparative Example 8 Using the thermosetting composition prepared in Comparative Example 1, the characteristics of the molded product and the molding material 50 were obtained in the same manner as in Example 11.
Table 5 shows the mold contamination after the kg molding.

Comparative Example 9 In Example 11, 85 parts by weight of phenol novolak and 15 parts by weight of hexamethylenetetramine used in (1) of Example 1 were used instead of 100 parts by weight of the thermosetting composition prepared in Example 1 A molding material and a molded product were produced in the same manner using the parts. Table 5 shows the characteristics of the molded product and the stains of the mold after molding of 50 kg.

The composition shown in each table is shown in parts by weight.

[0042]

[Table 1] (Note) Synthesized in (1) of Example 1

[0043]

[Table 2] (Note 1) A mixture of 100 parts by weight of bisphenol A type epoxy resin and 50 parts by weight of 4,4'-diaminodiphenylmethane (Note 2) Synthesized in (1) of Example 1 (Note 3) 4,4'-diphenylmethane Bismaleimide (Note 4) 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane (Note 5) As in Example 1, NMR spectrum of thermosetting resin having dihydrobenzoxazine ring and novolak phenol Calculated from the amount of resin added

[0044]

[Table 3]

[0045]

[Table 4]

[0046]

[Table 5]

[0047]

The thermosetting composition of the present invention gives a cured product having high heat resistance and high strength by its combined effect without using many expensive maleimide compounds. Therefore, the thermosetting composition of the present invention is an electronic component, a laminate for a printed wiring board and a printed wiring board, a semiconductor sealing material, an electronic material such as a semiconductor mounting module, an automobile / vehicle, an aircraft component, a building member,
It is useful as a raw material for machine tools.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the ratio of thermosetting resin (or epoxy resin) having a dihydrobenzoxazine ring / thermosetting resin having a maleimide ring and the glass transition temperature of a cured product.

Continued on the front page (72) Inventor Yoshinori Sato 1500, Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Plant, Hitachi Chemical Co., Ltd. (72) Inventor Minoru Kakitani 1500, Oji Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Factory, Hitachi Chemical Co., Ltd.

Claims (9)

[Claims] 1. A thermosetting resin having a dihydrobenzoxazine ring and a thermosetting resin having a maleimide ring as essential components, and the content of the thermosetting resin having a maleimide ring is the same as that of a thermosetting resin having a dihydrobenzoxazine ring. A thermosetting composition, which is 3 to 30% by weight based on the total amount of the curable resin and the thermosetting resin having a maleimide ring. 2. The thermosetting composition according to claim 1, comprising a thermosetting resin having a dihydrobenzoxazine ring, a thermosetting resin having a maleimide ring, and a novolak-type phenol resin as essential components. 3. The ratio of the total number of phenolic hydroxyl groups to the number of dihydrobenzoxazine rings (the number of phenolic hydroxyl groups / the number of dihydrobenzoxazine rings) in the thermosetting resin having a dihydrobenzoxazine ring and the novolak-type phenol resin is 1 3. The thermosetting composition according to claim 2, wherein the composition is not more than 0.5. 4. A thermosetting resin having a dihydrobenzoxazine ring comprises a compound having two or more phenolic hydroxyl groups having hydrogen bonded to at least one of the ortho positions in one molecule, a primary amine and formaldehyde. , 0.5 to 1.0 mole of primary amine per mole of phenolic hydroxyl group, and 2 moles of formaldehyde per mole of primary amine.
The thermosetting composition according to any one of claims 1 to 3, which is synthesized by reacting at a molar ratio or more. 5. A thermosetting resin having a maleimide ring,
The thermosetting composition according to any one of claims 1 to 4, which is a bismaleimide compound having two maleimide rings in one molecule. 6. A cured product obtained by curing the thermosetting composition according to claim 1. 7. A prepreg obtained by impregnating a substrate with the thermosetting composition according to claim 1 and drying the substrate. 8. A metal foil clad laminate obtained by laminating the prepreg according to claim 7 and a metal foil. 9. A printed wiring board obtained by performing circuit processing on the metal foil-clad laminate according to claim 8.