JP2002220513A - Epoxy resin composition for laminate, prepreg and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly reduce a coefficient of thermal expansion by compounding a small amount of an inorganic filler. SOLUTION: This epoxy resin composition for laminates is obtained by mixing a thermosetting resin having epoxy reactive groups with a flaky inorganic material obtained from a layer clay mineral and a curing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for producing a metal foil-clad laminate, a prepreg produced using the epoxy resin composition, and a laminate produced using the prepreg. is there.

[0002]

2. Description of the Related Art Conventionally, a prepreg is manufactured by impregnating a base material such as a glass cloth with a varnish of an epoxy resin composition and drying the laminated board used for processing into a printed wiring board. The prepreg is manufactured by laminating a required number of prepregs and further laminating a metal foil such as a copper foil on one side or both sides thereof, and subjecting them to heating and pressing.

[0003] In a laminated board which is processed into such a printed wiring board or the like, as the tendency of high density mounting and high integration of the printed wiring board becomes stronger, heat resistance and thermal expansion with the mounted parts are increased. Improvements in various characteristics such as a reduction in the coefficient of thermal expansion of the substrate and a processability for matching the coefficients have been demanded.

[0004] Therefore, heretofore, an epoxy resin has been conventionally made into a polyfunctional type, and dicyandiamide is used as a curing agent, diaminodiphenylsulfone, diaminodiphenylmethane, an alkylated or halogenated diaminodiphenylmethane, or the like is used as a curing agent. It has been proposed to modify an epoxy resin composition by modifying the resin with an imide resin. Recently, it has been proposed to use a phenolic resin such as a phenol novolak resin, a cresol novolak resin, or a bisphenol A type novolak resin as a curing agent (see JP-A-7-224147).

In addition to a method of improving the resin itself by modifying the resin, various methods of adding and mixing an inorganic filler have been proposed in order to improve the mechanical properties and heat resistance of the epoxy resin (Japanese Patent Laid-Open No. Hei 6 (1994)). No. 237055,
Japanese Patent Application Laid-Open No. H11-343398) and studies have been made to control the coefficient of thermal expansion of a resin and reduce the coefficient of thermal expansion of a substrate by adding an inorganic filler to form a composite.

[0006]

However, the inorganic filler mixed with the resin to control the thermal expansion is a particle of a micron order, and the effect of reducing the thermal expansion coefficient can be obtained only as a volume fraction effect. I can't. Therefore, in order to obtain a high effect of reducing the coefficient of thermal expansion, it is necessary to increase the compounding amount of the inorganic filler, and as the compounding amount of the inorganic filler increases, the flexibility, electrical properties, and toughness of the resin increase. There is a problem that such characteristics must be sacrificed.

[0007] As described above, most of the inorganic fillers conventionally used are on the order of microns, and the size of the resin is very different from that of the resin on the order of nanometers. The composite was a microscopically heterogeneous composite and therefore had problems with uniformity.

[0008] The present invention has been made in view of the above points, and it is an object of the present invention to significantly reduce the coefficient of thermal expansion by adding a small amount of an inorganic filler.

[0009]

According to the first aspect of the present invention, there is provided an epoxy resin composition for a laminate, comprising a thermosetting resin having an epoxy reactive group, a flaky inorganic substance obtained from a layered clay mineral, and a curing agent. Are mixed.

A second aspect of the present invention is characterized in that, in the first aspect, the flaky inorganic substance obtained from the layered clay mineral has an aspect ratio of 100 to 5,000.

According to a third aspect of the present invention, in the first or second aspect, the flaky inorganic material obtained from the layered clay mineral has a thickness of 5 to 50 ° and a length of 5 μm or less. .

Further, the invention according to claim 4 is the method according to any one of claims 1 to 3, wherein the layered clay mineral is a secondary amine (R ²
R ¹ NH) and at least one of an ion (R ² R ¹ NH ₂ ⁺ ) in which hydrogen is bonded to this secondary amine, and hydrogen bonded to a tertiary amine (R ³ R ² R ¹ N) and this tertiary amine At least one of the ions (R ³ R ² R ¹ NH ⁺ )
R ³ , R ² , and R ¹ each represent an alkyl group having 1 to 30 carbon atoms, or — (R ⁴ —O) _m —H (R ⁴ has 1 to 6 carbon atoms.
Alkylene group, m is an integer of 1 or more), or -R ⁵
-OH, and it is characterized in that ^{-R 6 -COOH (R 5, R} 6 is an alkylene group having 1 to 30 carbon atoms, respectively) are those that are] processed.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the amount of the flaky inorganic substance obtained from the layered clay mineral is 0.1 to 30% by mass based on the thermosetting resin. It is characterized by the following.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, an alkyl monoethanolamine (C ₁₂ H ₂₅ NHCH ₂ CH ₂₎ is used as the ion in which hydrogen is bonded to the secondary amine.
OH) or polyfunctional amine (RNHCH ₂ CH ₂ HNCH ₂
CH ₂ CH ₂ NHCOOH) is used as an ion in which hydrogen is bonded, and as the ion in which hydrogen is bonded to a tertiary amine, an ion in which hydrogen is bonded to alkylbishydroxyethylamine (RR′R ″ N) is used. R 'is-(CH
_{2 CH 2 O) 5 H,} R " is -C ₁₂ H ₂₅ or -C ₁₈ H _37)]
It is characterized by the following.

A prepreg according to a seventh aspect of the present invention is characterized in that a varnish obtained by dissolving the epoxy resin composition according to any one of the first to sixth aspects in a solvent is impregnated into a substrate and dried. It is assumed that.

According to an eighth aspect of the present invention, in the seventh aspect, the base material is a glass woven fabric or a glass nonwoven fabric.

A laminate according to a ninth aspect of the present invention is characterized in that a metal foil is laminated on the prepreg according to the seventh or eighth aspect and is subjected to heat and pressure molding.

[0018]

Embodiments of the present invention will be described below.

In the present invention, the thermosetting resin having an epoxy reactive group includes bisphenol A type epoxy resin having at least two epoxy groups in one molecule,
Phenol novolak type epoxy resin having two or more epoxy groups in one molecule, ortho-cresol novolak type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, trifunctional or higher functional polyfunctional epoxy resin and bromide thereof Examples thereof include mixtures thereof, and any type can be used as long as it is heat-curable, and ordinary epoxy resins used for laminates can be used.

In the present invention, the curing agent used to cure the epoxy resin is dicyandiamide,
Catalyst type and aromatic polyamine type are preferred.
Examples thereof include ₃ -monoethylamine, benzyldimethylamine, dicyandiamide, phenylimidazole, metaphenylenediamide, diphenyldiamonosulfone, and diphenyldiaminomethane.

Further, as the curing agent, a compound having two or more phenolic OH groups in one molecule can be used. Examples of this compound include bisphenol A,
Bisphenol F, bisphenol S, polyvinyl phenol, low molecular compounds such as β-naphthol, phenol novolak resin, cresol novolak resin, bisphenol A type novolak resin, alkylphenol novolak resin, triphenylmethane type synthesized from phenol and hydroxybenzaldehyde Examples thereof include trifunctional novolak resins and bromides thereof. These phenolic compounds and resins may be used alone or in combination of two or more.

As the curing agent, an aromatic organic amine having two or more amino groups in one molecule can be used. As the aromatic organic amine, diaminodiphenylmethane (DDM) or a derivative thereof can be used.

In the case of dicyandiamide, the compounding amount of the curing agent is set so as to be in the range of about 0.1 to 0.6 equivalent per equivalent of epoxy group. Preferred from the point. In the case of a compound having a phenolic OH group, the OH group is set so as to be in the range of about 0.1 to 0.6 equivalent per equivalent of epoxy group. (T
g) is preferable in terms of compatibility. Further, in the case of an aromatic organic amine, the NH equivalent is 0.1 to 0.1 equivalent per epoxy group equivalent.
Tg is set to be in the range of about 0.6 equivalent.
It is preferable from the viewpoint of heat resistance after moisture absorption. The ratio of these curing agents to the epoxy resin was 1: 0.8 in equivalent ratio.
It is preferable to set the range of １ ： 1: 1.2 from the viewpoint of Tg and hygroscopicity. When these three types of curing agents are used in combination, the advantages of improving the adhesiveness of dicyandiamide, improving the heat resistance of phenolic compounds and the preservability of prepreg, and the heat resistance of moisture absorption and prepreg storage of aromatic organic amines are utilized. This makes it possible to make up the advantages as a greater effect by compensating for the mutual disadvantages. Then, these three types of curing agents are dissolved in a solvent such as cellosolves such as methyl cellosolve, dimethylformamide (DMF), and methyl ethyl ketone (MEK) in advance.
Preliminary reaction is preferably carried out by heating at ~ 150 ° C for 10-60 minutes from the viewpoint of improving the potential.

In the present invention, a curing accelerator is used as needed, and 2-ethyl-4-methylimidazole (2) conventionally known for epoxy resins is used.
E4MZ), tertiary organic amines and the like.

In the present invention, a layered clay mineral is mixed and used as the inorganic filler. As the layered clay mineral, synthetic mica, smectite, montmorillonite, bentonite, hectorite, saponite, beidellite and the like can be used. Among these, the layered clay mineral has a cation exchange capacity of 40 to 140 meq / 100 g.
Is preferred. The compounding amount of the layered clay mineral is preferably in the range of 1 to 30% by mass based on the resin solid content of the epoxy resin composition. When the compounding amount of the layered clay mineral is less than 1% by mass, it becomes difficult to reduce the thermal expansion coefficient of the laminate by compounding the inorganic filler. If the amount of the layered clay mineral exceeds 30% by mass, the properties such as flexibility, electrical properties, and toughness of the epoxy resin may be impaired by the inorganic filler.

Thus, an epoxy resin composition can be obtained by mixing the above-mentioned epoxy resin and layered clay mineral, and further mixing a curing agent and, if necessary, a curing accelerator. These components are usually diluted with a solvent.
Dispersed and used as a varnish. Examples of such a solvent include methyl ethyl ketone, acetone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methanol, ethanol, toluene, xylene, DMF, and dimethylacetamide (D
MAc) and the like can be used, and these can be used alone or in combination of two or more. The dilution ratio is preferably set so that the solid content of the resin is in the range of 50 to 70% by mass.

Then, the varnish of the epoxy resin composition thus obtained is impregnated into a substrate, and the resultant is passed through a dryer and heated and dried at a temperature of 120 to 180 ° C. for 3 to 10 minutes, thereby obtaining an epoxy resin. Can obtain a prepreg semi-cured on the B stage. As the substrate, glass woven fabric (glass cloth), glass nonwoven fabric (glass paper), kraft paper, linter paper, cloth, or the like can be used. Among these, a glass woven fabric or a glass nonwoven fabric is particularly desirable as the substrate.

Next, one or more sheets of the prepreg obtained as described above are stacked in a required number, and a metal foil is stacked on one or both sides thereof. By curing, a metal foil-clad laminate can be obtained. Appropriate materials such as copper, aluminum, and stainless steel can be used as the metal foil. The heating and pressing conditions during molding are 15
0 to 200 ° C, 0.98 to 4.9 MPa (10 to 50 k
g / range cm ²⁾ is preferred. In the case of manufacturing a multilayer board, the surface of a metal foil such as a copper foil as an inner layer is subjected to a blackening treatment to chemically treat it as copper oxide, so that the molding temperature is in a range of 150 to 180 ° C. It is preferred that

The epoxy resin of the laminate obtained as described above contains an inorganic filler composed of a layered clay mineral. Here, the thermal expansion coefficient α of the composite material of the resin and the inorganic filler is generally α = αf × Vf + αm × Vm (αf: thermal expansion coefficient of the inorganic component, Vf: volume fraction of the inorganic component, αm: heat of the resin component Expansion coefficient, Vm: volume fraction of the resin component).

According to this, the thermal expansion coefficient is 65p
Assuming that an inorganic component having a thermal expansion coefficient of 5 ppm is dispersed in a resin component of pm, the thermal expansion coefficient of a composite material including the resin component and the inorganic component is as shown in Table 1 below.

[0031]

[Table 1]

However, the thermal expansion coefficient α of a composite material in which an inorganic component having a very large aspect ratio is uniformly and randomly blended in a resin component is as follows: α = αm + Kf (4Gf + 3Km) × (αf−αm) ×
Vf / ｛Kf × (4GfVf + 3Km) + 4GfKmV
f｝ (Gf: shear modulus of inorganic component, Kf: bulk modulus of inorganic component, Gm: shear modulus of resin component, Gm: bulk modulus of resin component).

According to this, the thermal expansion coefficient of the composite material comprising the resin component and the inorganic component is as shown in Table 2 below.

[0034]

[Table 2]

As can be seen from the comparison between Tables 1 and 2, it is expected that an extremely large effect of reducing the thermal expansion coefficient can be expected by using the inorganic filler having a high aspect ratio when mixing the inorganic filler with the resin. .

However, the inorganic filler having a high aspect ratio, that is, the ratio of the average thickness to the average length of the filler, has a very large shape with a size (length) of several tens to several hundreds μm or more. As described above, it cannot be expected that a high effect of reducing the coefficient of thermal expansion can be obtained with this material, and the inorganic filler having such a large shape is pulverized at the time of mixing and becomes small, and the aspect ratio is reduced. Is usually small, and there is a possibility that the effect of reducing the thermal expansion coefficient by combining the inorganic filler may not be obtained. Also like this, dozens to hundreds of μ
When a large inorganic filler of m or more is contained, the inorganic filler may act as a foreign substance or impurity when applied to a printed wiring board corresponding to high-density mounting and high integration.

Therefore, in the present invention, one layer of the layered clay mineral mixed as an inorganic filler is exfoliated to form an ultrafine inorganic filler having a nano-level size (length) and an aspect ratio of several hundred or more. By making it evenly dispersed in the epoxy resin, it is possible to obtain a high effect of reducing the coefficient of thermal expansion with a small amount of compounding, and the inorganic filler does not act as a foreign substance or impurity, and high density mounting And a low-thermal-expansion printed wiring board compatible with high integration.

For this purpose, it is necessary to carry out a process of introducing an organic amine which acts as a curing agent for reacting with the epoxy group to polymerize and curing the epoxy resin, between the layers of the layered clay mineral. In the present invention, it is preferable to use a combination of secondary amines and tertiary amines as the organic amines used for treating the layered clay mineral. Here, the secondary amines in the present invention and a secondary amine formula is expressed as R ² R ¹ N are those hydrogen to the secondary amine consists R _² R ¹ NH ^{2 +} is bound ions It is also possible to use one of the secondary amine and its ion or to use both in combination. In the present invention, the term "tertiary amines" refers to a tertiary amine represented by a chemical formula of R ³ R ² R ¹ N, and R ³ which is an ion in which hydrogen is bonded to the tertiary amine.
It is composed of R ² R ¹ NH ⁺ , and either a tertiary amine and one of its ions or a combination of both can be used. However, each of R ³ , R ² and R ¹ is an alkyl group having 1 to 30 carbon atoms, or-[R ⁴ -O] _m -H
(R ⁴ is an alkylene group having 1 to 6 carbon atoms, m is an integer of 1 to 8), or —R ⁵ —OH, —R ⁶ —COOH (R ⁵ ,
R ⁶ is preferably an alkylene group having 1 to 30 carbon atoms.

Particularly preferred among these are, as an ion in which hydrogen is bonded to a secondary amine, an ion in which hydrogen is bonded by reacting hydrochloric acid with alkyl monoethanolamine (C ₁₂ H ₂₅ NHCH ₂ CH ₂ OH), Polyfunctional amine (RNHCH ₂ CH ₂ HNCH ₂ CH ₂ CH ₂ NHCOO
H) is reacted with hydrochloric acid to form hydrogen-bonded ions, and tertiary amine is converted to hydrogen-bonded ions. Alkylbishydroxyethylamine (RR′R ″ N) is reacted with hydrochloric acid to form hydrogen-bonded ions. Provided that R and R ′ are — (CH ₂ CH ₂ O) ₅ H, and R ″ is —C ₁₂
H ₂₅ or C ₁₈ H _37.

In treating the layered clay mineral with an organic amine, a mixture of the layered clay mineral and the above-mentioned organic amine is dissolved and dispersed in an aqueous solution and mixed with stirring, and then centrifuged to separate the layered clay mineral. Further, by repeating the operations of dispersing in an aqueous solution and centrifuging again to remove unnecessary ionic species, organic amines can be introduced between layers of the layered clay mineral. The amount of organic amines to be processed into the layered clay mineral is 100
The range of 20 to 200 parts by mass relative to parts by mass is preferred.
By using a secondary amine and a tertiary amine in combination, it is possible to obtain a high dispersibility of the flaky inorganic substance obtained from the layered clay mineral. The mixing ratio of the secondary amines and the tertiary amines is not particularly limited.

When the layered clay mineral thus treated with the organic amines is mixed with the epoxy resin, the epoxy resin penetrates between the layers of the layered clay mineral spread with the organic amines to cause a polymerization reaction. At this time, not only the epoxy resin between the layers but also the epoxy resin is taken in sequentially from the outside of the layer, so that the polymerization reaction takes place, so that the volume of the reaction product between the layers increases, and the driving force (propulsion) due to the volume increase causes the layered clay mineral. Delamination occurs, and a flaky inorganic substance having a high aspect ratio and a nano-level size of submicron or less is generated.

In order to efficiently obtain the effect of delaminating the layered clay mineral to form a flaky inorganic material, it is necessary to use a bisphenol A type epoxy resin which is easily inserted between layers of the layered clay mineral spread with organic amines. It is preferably used. The bisphenol A type has a linear molecular structure with little steric hindrance, and has a structure that easily enters between layers of a layered clay mineral, and is particularly a liquid bisphenol A type epoxy having a short molecular length. It is more preferable to use a resin effectively. In addition, when a layered clay mineral and an epoxy resin are stirred in a polar solvent such as DMF or DMAc, which is more likely to enter between layers of the layered clay mineral than the epoxy resin, the layered clay mineral is swollen with the solvent and the interlayer is expanded. It is possible to make it easy for the epoxy resin to enter between the layers. Further, the mixture of the layered clay mineral and the epoxy resin is heated to 80 to 150 ° C.
By keeping the temperature at the above, the polymerization reaction of the epoxy resin between the layers of the layered clay mineral can be easily promoted. Heating by a batch type autoclave,
More preferably, an ultrasonic dispersion homogenizer is used in combination.

Further, among organic amines reactive with the epoxy resin, it is preferable to use secondary amines and tertiary amines having a catalytic property for inserting the epoxy resin between layers of the layered clay mineral. Since primary amines have high reactivity with epoxy resin, the reaction is terminated only by the epoxy resin between the layers of the layered clay mineral, and it is not possible to take in the epoxy resin from outside the layer and react it. In this case, the volume expansion cannot be caused, so that the driving force is insufficient, delamination does not occur, and a flaky inorganic material having a high aspect ratio and a nano-level size cannot be obtained. Therefore, it is preferable to use such secondary amines or tertiary amines having catalytic properties.

An epoxy resin composition in which a flaky inorganic material having a high aspect ratio and a nano-level size obtained by exfoliating a layered clay mineral one by one between layers as described above is uniformly mixed and dispersed in an epoxy resin. The epoxy resin composition according to the present invention is prepared by further adding another epoxy resin, if necessary, and a curing agent, and a curing accelerator, if necessary. Is what you can do. This epoxy resin composition is used as a varnish after being dissolved and dispersed in a solvent as described above. Here, the flaky inorganic material obtained from the layered clay mineral preferably has an aspect ratio in the range of 100 to 5,000, and the size is 5 to 50 in thickness.
Å, the length is preferably 5 μm or less. When the aspect ratio of the flaky inorganic material is less than 100, the thickness is 50 mm.
When the length exceeds 5 μm, it is difficult to obtain an effect of greatly reducing the coefficient of thermal expansion with a small amount of blending. On the other hand, the minimum thickness of each layer of the layered clay mineral is about 5 mm, so the substantial lower limit of the thickness is set to 5 mm. The upper limit of the length is 5 μm, and the lower limit of the thickness is 5 mm.
Therefore, the substantial upper limit of the aspect ratio of the flaky inorganic material is set to 5000. The lower limit of the length of the flaky inorganic material is not particularly limited, but the lower limit of the length of the flaky inorganic material formed by exfoliation from the layered clay mineral is substantially 0.1 μm.
m.

[0045]

Next, the present invention will be described specifically with reference to examples.

(Example 1) An ion (RR'R ") obtained by reacting hydrochloric acid with a tertiary amine as an organic amine using synthetic mica manufactured by Corp Chemical as a layered clay mineral.
NH ⁺⁾ [where, R, R 'is _{- (CH 2 CH 2 O)} 5 H,
R "ions are obtained -C ₁₈ H _37] is reacted with hydrochloric acid to secondary amine _{[(C 12 H 25 NHCH 2} CH 2 OH) H +]
Were mixed at a mass ratio of 1: 1 and used. Then, 120 parts by mass of an organic amine was added to 100 parts by mass of the layered clay mineral, and both were dissolved and dispersed in an aqueous solution. After stirring at room temperature for 30 minutes, the mixture was further stirred at 80 ° C. for 30 minutes, and then centrifuged. To separate the layered clay mineral as a solid. Further, the separated layered clay mineral was dispersed in water and centrifuged to remove unnecessary ions, thereby obtaining a layered clay mineral treated with organic amines.

First, 20 parts by mass of a bisphenol A type epoxy resin (“YD011” manufactured by Toto Kasei Co., Ltd .: epoxy equivalent: 475 g / eq) and 20 parts by mass of DMF are mixed, and the mixture is treated with the above-mentioned organic amine. The layered clay mineral was added so as to be 1% by mass with respect to the epoxy resin finally contained in the composition, and mixed by stirring for 30 minutes. In this way, an epoxy composite layered clay mineral having a structure in which the bisphenol A type epoxy resin penetrated into the layers of the layered clay mineral and expanded between the layers was obtained. By measuring the X-ray diffraction peak position of the (001) bottom surface interval of the layered clay mineral at this time, it was confirmed that the bottom surface interval increased from about 10 ° to 35 °.

In this state, the layered clay mineral does not delaminate only because the interlayer distance is widened. Therefore, the layered clay mineral was heated using an oil bath and stirred and mixed at 100 ° C. for 2 hours. By this heating, the layered clay mineral was completely peeled off between the layers, and became a flaky inorganic substance that could be dispersed in a nanometer size. At this time, by measuring the X-ray diffraction peak position of the (001) bottom surface interval of the layered clay mineral, the bottom surface interval was 35 ° to 100 °.
Å It was confirmed that the number increased.

After performing the heat dispersion treatment as described above, a trifunctional epoxy resin (“VG” manufactured by Mitsui Petrochemical Industries, Ltd.)
3101 ": 80 parts by mass of epoxy equivalent 210 g / eq), dicyandiamide (amine equivalent 21 g) as a curing agent
/ Eq) is 50 parts by mass, and 2-ethyl- as a curing accelerator is used.
4-methylimidazole (“2E4” manufactured by Shikoku Chemicals Co., Ltd.
MZ ”), and 0.1 part by mass of DMF, and 30 parts by mass of DMF.
The mixture was sufficiently stirred to obtain a varnish of the epoxy resin composition.

[0050]

[Table 3]

The varnish obtained as described above was impregnated into a 7628-type glass woven fabric and dried at 160 ° C. for 5 minutes to prepare a prepreg.

Next, six prepregs were laminated, and a copper foil having a thickness of 35 μm was further laminated on both surfaces thereof.
At 3.9 MPa (40 kg / cm ² ) at 90 ° C., the laminate was molded by heating and pressing for 90 minutes to obtain a double-sided copper foil-clad laminate.

When the X-ray diffraction peak of the epoxy resin cured product in the laminate thus obtained was analyzed by an X-ray diffraction peak, a diffraction peak on the (001) plane of the layered clay mineral was observed from a wide angle side to 2 degrees. However, it was determined that the layered clay mineral was separated one by one and dispersed microscopically. The state of filler dispersion of the cured epoxy resin in the laminate is measured by a scanning electron microscope (SEM) or a transmission electron microscope (TEM).
And the resin impregnated between the glass woven fabrics was 5 to 15 mm thick, 2 to 3 μm in length, and the aspect ratio was 200.
It was confirmed that 0 to 3000 flaky inorganic substances were dispersed. After polishing the cross section of the laminate, morphology observation by SEM was performed. As a result, non-uniformity such as aggregation of the filler was not recognized, and it was confirmed that the resin composition had a very uniform nano-level resin composition.

(Examples 2 to 4) The layered clay mineral treated with an organic amine was adjusted to 3% by mass with respect to the epoxy resin finally contained in the composition (Example 2) or 5 A double-sided copper foil-clad laminate was obtained in the same manner as in Example 1, except that the respective components were added so that the amount became 7% by mass (Example 3) or 7% by mass (Example 4). Was.

In this case, similarly to Example 1, an epoxy composite layered clay mineral having a structure in which the bisphenol A type epoxy resin penetrated into the layers of the layered clay mineral by mixing at room temperature and spread between the layers was obtained. Further, by stirring and mixing at 100 ° C. for 2 hours using an oil bath, the interlayer of the layered clay mineral was completely peeled off, and became a flaky inorganic substance having a nano-level size and dispersible. Measurement of the X-ray diffraction peak position of the (001) bottom surface interval of the layered clay mineral at this time confirmed that the bottom surface interval increased from 35 ° to 100 ° or more.

Example 5 An ion (RR'R "NH) obtained by reacting hydrochloric acid with a tertiary amine as an organic amine
⁺⁾ [Where, R, R 'is _{- (CH 2 CH 2 O)} 5 H, R " is -C ₁₂ H _25] ions obtained is reacted with hydrochloric acid to secondary amine [(C ₁₂ H ₂₅ NHCH ₂ CH ₂ OH) H ⁺ ]:
Example 2 was repeated except that the mixture was used at a mass ratio of 1.
In the same manner as in the above, a double-sided copper foil-clad laminate was obtained.

Even in this case, similar to the second embodiment,
By mixing at room temperature, the bisphenol A-type epoxy resin penetrated between the layers of the layered clay mineral to obtain an epoxy composite layered clay mineral having a structure in which the layers spread. Further, by stirring and mixing at 100 ° C. for 2 hours using an oil bath, the interlayer of the layered clay mineral was completely peeled off, and became a flaky inorganic substance having a nano-level size and dispersible. Measurement of the X-ray diffraction peak position of the (001) bottom surface interval of the layered clay mineral at this time confirmed that the bottom surface interval increased from 35 ° to 100 ° or more.

(Example 6) A double-sided copper foil-clad laminate was obtained in the same manner as in Example 2, except that diphenyldiaminomethane (DDM) was used as a curing agent.

Even in this case, similar to the second embodiment,
By mixing at room temperature, the bisphenol A-type epoxy resin penetrated between the layers of the layered clay mineral to obtain an epoxy composite layered clay mineral having a structure in which the layers spread. Further, by stirring and mixing at 100 ° C. for 2 hours using an oil bath, the interlayer of the layered clay mineral was completely peeled off, and became a flaky inorganic substance having a nano-level size and dispersible. Measurement of the X-ray diffraction peak position of the (001) bottom surface interval of the layered clay mineral at this time confirmed that the bottom surface interval increased from 35 ° to 100 ° or more.

(Comparative Example 1) A varnish of an epoxy resin composition was prepared according to the composition shown in Table 3 without adding a layered clay mineral treated with an organic amine, and thereafter, a double-sided copper foil-clad laminate was prepared in the same manner as in Example 1. I got

Comparative Example 2 An epoxy resin composition was prepared in the same manner as in Example 2 except that a layered clay mineral which had not been treated with an organic amine was used and mixed with the composition shown in Table 3 to prepare an epoxy resin composition. Similarly, a double-sided copper foil-clad laminate was obtained.

(Comparative Example 3) In mixing an epoxy resin with a layered clay mineral treated with an organic amine, a bisphenol A type epoxy resin ("Y" manufactured by Toto Kasei Co., Ltd.)
A double-sided copper foil-clad laminate was obtained in the same manner as in Example 1, except that a trifunctional epoxy resin (“VG3101” manufactured by Mitsui Petrochemical Industries, Ltd.) was used instead of D011 ”).

(Comparative Example 4) Instead of the layered clay mineral treated with an organic amine, a spherical silica powder having a particle size of 0.5 µm ("SO-25R" manufactured by Tatsumori Co., Ltd.) was used.
A double-sided copper foil-clad laminate was obtained in the same manner as in Example 2, except that the epoxy resin composition was prepared by mixing with the above composition.

Comparative Example 5 An ion [(H ₂ NC ₁₁ H ₂₂ COOH) H ⁺ ] obtained by reacting hydrochloric acid with a primary amine (aminododecanoic acid) as an organic amine was used. A double-sided copper foil-clad laminate was obtained in the same manner as in Example 2.

The copper foil peel strength, thermal expansion coefficient, and glass transition temperature (Tg) of the double-sided copper foil-clad laminates of Examples 1 to 6 and Comparative Examples 1 to 5 obtained as described above were measured. The measurement of the coefficient of thermal expansion is performed by cutting the laminated board from which the copper foil on the surface has been removed by etching into 6 mm squares, and using “SSC5200TMA3200” manufactured by Seiko Instruments Inc., and raising the temperature by 10 ° C./min in the thickness direction. The measurement was performed by measuring the coefficient of thermal expansion from room temperature to 200 ° C. at a speed, and the inflection point in the temperature-displacement graph obtained by this measurement was taken as the glass transition temperature. The copper foil peel strength was measured by cutting a double-sided copper-clad laminate into a strip having a width of 100 mm and cutting the copper foil on the surface of the laminate in a direction perpendicular to the laminate by 50 mm.
The strength when peeled off at a rate of mm / min was measured. Table 4 shows the results.

[0066]

[Table 4]

As can be seen from the results of Examples 1 to 4, a decrease in the coefficient of thermal expansion was confirmed by a small amount of the flaky inorganic substance obtained from the layered clay mineral (for example, 3% by mass in Example 2). 1 more than that of Comparative Example 1
The thermal expansion coefficient was reduced by 0.5%), and the peel strength of the copper foil could be secured. Also in Examples 5 and 6, a large reduction in the coefficient of thermal expansion could be achieved with a small amount of compounding without lowering the peel strength of the copper foil.

On the other hand, in the case of Comparative Example 2, since the layered clay mineral not treated with the organic amines is used, the layered clay mineral does not delaminate, and a nano-level flaky inorganic substance cannot be obtained. Therefore, the coefficient of thermal expansion was only reduced by about 3% from that of Comparative Example 1.

In Comparative Example 3, the bisphenol A type epoxy resin was not used, so that no epoxy resin component was inserted between the layers of the layered clay mineral, and the delamination of the layered clay mineral was insufficient. Therefore, the production of flaky inorganic substances at the nano level is insufficient. Therefore, although the crosslink density increased and the glass transition temperature increased with an increase in the amount of the trifunctional epoxy resin, the coefficient of thermal expansion was reduced only by about 5% from that of Comparative Example 1.

The thermal expansion coefficient of Comparative Example 4 was only reduced by about 5% from that of Comparative Example 1.

In Comparative Example 5, since the primary amines were used as the treating agent, the delamination of the layered clay mineral was insufficient and the production of nano-level flaky inorganic substances was insufficient. Therefore, although the crosslink density increased and the glass transition temperature increased with an increase in the amount of the trifunctional epoxy resin, the coefficient of thermal expansion was reduced only by about 3% from that of Comparative Example 1.

[0072]

As described above, the epoxy resin composition for a laminate according to claim 1 of the present invention comprises a thermosetting resin having an epoxy reactive group, a flaky inorganic substance obtained from a layered clay mineral, and a curing agent. Are mixed, and the flaky inorganic material obtained from the layered clay mineral has a nano-level size,
The thermal expansion coefficient can be greatly reduced with a small amount of blending.

According to a second aspect of the present invention, the flaky inorganic substance obtained from the layered clay mineral has an aspect ratio of 100 to 50.
Since it is 00, the coefficient of thermal expansion can be greatly reduced with a small amount of compounding.

According to a third aspect of the present invention, the flaky inorganic material obtained from the layered clay mineral has a thickness of 5 to 50 ° and a length of 5 to 50 °.
Since it is not more than μm, the coefficient of thermal expansion can be greatly reduced with a small amount of compounding.

The invention according to claim 4 is characterized in that the layered clay mineral is
At least one of a secondary amine (R ² R ¹ NH) and an ion (R ² R ¹ NH ₂ ⁺ ) in which hydrogen is bonded to the secondary amine, and a tertiary amine (R ³ R ² R ¹ N) and the secondary amine At least one of the ion (R ³ R ² R ¹ NH ⁺ ) in which hydrogen is bonded to the triamine [provided that R ³ , R ² , and R ¹ each have ¹ to 3 carbon atoms
0 alkyl group, or _{^{- (R 4 -O) m -H}} (R 4 is an alkylene group having 1 to 6 carbon atoms, m is an integer of 1 or more), or -R ⁵ -OH, -R ⁶ -COOH ( R ⁵ and R ⁶ are each an alkylene group having 1 to 30 carbon atoms)], and can be efficiently delaminated from the layered clay mineral. Inorganic substances can be obtained efficiently, and the coefficient of thermal expansion can be greatly reduced.

The invention according to claim 5 is characterized in that the amount of the flaky inorganic substance obtained from the layered clay mineral is 0.1 to 30% by mass based on the thermosetting resin. The level of flaky inorganic material can significantly reduce the coefficient of thermal expansion.

The invention according to claim 6 is characterized in that the ion in which hydrogen is bonded to the secondary amine is alkylmonoethanolamine (C ₁₂ H ₂₅ NHCH ₂ CH ₂ OH) or polyfunctional amine (RNHCH ₂ CH ₂ HNCH ₂ CH _2). CH ₂ NHCOO
H) is an ion in which hydrogen is bonded to a tertiary amine, and an ion in which hydrogen is bonded to alkylbishydroxyethylamine (RR′R ″ N) is used as an ion in which hydrogen is bonded to a tertiary amine. , R 'is - (CH ₂ C
_{H 2 O) 5 H, R} " is -C ₁₂ H ₂₅ or -C ₁₈ H _37)] and can be performed efficiently delamination of the layered clay mineral,
Nano-level flaky inorganic substances can be efficiently obtained from layered clay minerals, and the coefficient of thermal expansion can be greatly reduced.

A prepreg according to a seventh aspect of the present invention is obtained by impregnating and drying a varnish obtained by dissolving the epoxy resin composition according to any one of the first to seventh aspects in a solvent. Therefore, a laminate having a small coefficient of thermal expansion can be obtained using this prepreg.

The invention according to claim 8 is characterized in that the base material is a glass woven fabric or a glass nonwoven fabric, and a laminate having a high reinforcing strength by the base material can be obtained.

A laminate according to a ninth aspect of the present invention is obtained by laminating a metal foil on the prepreg according to the seventh or eighth aspect and heating and pressing to obtain a laminate having a small coefficient of thermal expansion. Is what you can do.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 9/04 C08K 9/04 H05K 1/03 610 H05K 1/03 610L F-term (Reference) 4F072 AA04 AA05 AA07 AB09 AB28 AB29 AD23 AE00 AE13 AE24 AF01 AG03 AG19 AH02 AH22 AJ04 AK05 AK14 AL09 AL13 4F100 AB01A AB01C AB17 AB33A AB33C AD01B AH03 AH05 AH07 AK53B BA03 BA06 BA10A BA10C CA02 DE02B EJ12 EB12 EB12 EB12 EB12 DG12 EB01 EB12 CD05W CD06W DM007 EJ016 EJ036 EN006 ER026 EU116 FA017 FA097 FD017 FD14X FD146 GF00

Claims (9)

[Claims] 1. An epoxy resin composition for a laminate, comprising a thermosetting resin having an epoxy reactive group, a flaky inorganic substance obtained from a layered clay mineral, and a curing agent. 2. The epoxy resin composition for a laminated board according to claim 1, wherein the flaky inorganic substance obtained from the layered clay mineral has an aspect ratio of 100 to 5,000. 3. The epoxy resin composition for a laminate according to claim 1, wherein the flaky inorganic material obtained from the layered clay mineral has a thickness of 5 to 50 ° and a length of 5 μm or less. 4. The method according to claim 1, wherein the layered clay mineral is a secondary amine (R ² R ¹ N).
H) and an ion in which hydrogen is bonded to this secondary amine (R ² R ¹
NH ₂ ⁺ ) and a tertiary amine (R ³ R ² R
¹ N) and an ion in which hydrogen is bonded to this tertiary amine (R ³ R
² R ¹ NH ⁺ ), wherein R ³ , R ² ,
Each R ¹ is an alkyl group having 1 to 30 carbon atoms, or _{^{- (R 4 -O) m -H}} (R 4 is an alkylene group having 1 to 6 carbon atoms, m is an integer of 1 or more), or -R ⁵ -OH,-
R ⁶ —COOH (R ⁵ and R ⁶ are each an alkylene group having 1 to 30 carbon atoms)].
The epoxy resin composition for a laminate according to any one of the above. 5. The method according to claim 1, wherein the amount of the flaky inorganic substance obtained from the layered clay mineral is 0.1 to 30% by mass based on the thermosetting resin. Epoxy resin composition for laminates. 6. An ion in which hydrogen is bonded to a secondary amine.
And alkyl monoethanolamine (C₁₂H_{twenty five}NHCH
_TwoCH_TwoOH) or polyfunctional amine (RNHCH) _TwoCH_TwoHN
CH_TwoCH_TwoCH_TwoNHCOOH)
Using hydrogen, as an ion with hydrogen bonded to the tertiary amine,
Alkyl bishydroxyethylamine (RR'R "N)
[Where R and R 'are-
(CH_TwoCH_TwoO)_FiveH, R "is -C₁₂H_{twenty five}Or -C₁₈H
₃₇The laminate according to claim 4 or 5, wherein
Epoxy resin composition for use. 7. A prepreg obtained by impregnating and drying a varnish obtained by dissolving the epoxy resin composition according to claim 1 in a solvent. 8. The prepreg according to claim 7, wherein the substrate is a glass woven fabric or a glass nonwoven fabric. 9. A laminate obtained by laminating a metal foil on the prepreg according to claim 7 and heating and pressing the laminate.