Conductive composition and conductive molded body

Abstract

The present invention relates to a conductive composition containing a conductive metal powder and an epoxy resin component in which the conductive metal powder contains a metal flake and the epoxy resin component contains a polyfunctional epoxy resin having three or more epoxy groups.

Claims

1. A conductive composition comprising a conductive metal powder and an epoxy resin component, wherein the conductive metal powder comprises a metal flake and the epoxy resin component comprises a polyfunctional epoxy resin having three or more epoxy groups, and when the average particle diameter of the metal flake is taken as A (μm) and the BET specific surface area of the metal flake is taken as B (m.sup.2/g), the value of A×B.sup.2 is from 7 to 18.

2. The conductive composition according to claim 1, wherein the metal flake has an average particle diameter of 0.7 to 10 μm, a BET specific surface area of 1 to 5 m.sup.2/g, and a tap density of 0.5 to 4.5 g/cm.sup.3.

3. The conductive composition according to claim 1, wherein the metal flake has an average particle diameter of 0.5 to 3.5 μm, a BET specific surface area of 1 to 4.5 m.sup.2/g, and a tap density of 1.2 to 3.5 g/cm.sup.3.

4. The conductive composition according to claim 1, wherein the metal flake is a flaked product of an aggregated powder of a spherical metal fine particle.

5. The conductive composition according to claim 1, wherein the conductive metal powder further comprises a spherical metal nanoparticle.

6. The conductive composition according to claim 5, wherein the ratio of the metal flake to the spherical metal nanoparticle is as follows: the former/the latter (weight ratio)=99/1 to 50/50.

7. The conductive composition according to claim 1, wherein the polyfunctional epoxy resin is an aromatic epoxy resin.

8. The conductive composition according to claim 1, wherein the polyfunctional epoxy resin has an epoxy equivalent of 350 g/eq or less.

9. The conductive composition according to claim 1, wherein the polyfunctional epoxy resin is a glycidyl ether type aromatic epoxy resin having an epoxy equivalent of 140 to 320 g/eq.

10. The conductive composition according to claim 1, wherein the epoxy resin component comprises a curing agent composed of an aromatic amine-based curing agent.

11. The conductive composition according to any claim 1, wherein the ratio of the conductive metal powder to the epoxy resin component is as follows: the former/the latter (weight ratio)=99/1 to 50/50.

12. The conductive composition according to claim 1, which is a conductive adhesive.

13. The conductive composition according to claim 1, which is a conductive adhesive for bonding a lead frame with a semiconductor chip.

14. A conductive molded body comprising at least a conductive region formed of the conductive composition described in claim 1.

15. The conductive molded body according to claim 14, which is a molded body comprising a conjugated base material composed of two base materials and a conductive adhesive that intervenes between the base materials and bonds the two base materials each other, wherein the conductive adhesive is formed of a conductive composition comprising a conductive metal powder and an epoxy resin component, wherein the conductive metal powder comprises a metal flake, and the epoxy resin component comprises a polyfunctional epoxy resin having three or more epoxy groups, and when the average particle diameter of the metal flake is taken as A (μm) and the BET specific surface area of the metal flake is taken as B (m.sup.2/g), the value of A×B.sup.2 is from 7 to 18.

Description

EXAMPLES

(1) The following will describe the present invention in more detail with reference to Examples, but the present invention is not limited by these Examples. Various components used in Examples and Comparative Examples are as follows.

(2) (Polyfunctional Epoxy Resin Component A)

(3) A polyfunctional epoxy resin component A was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 27.3 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine) and 1.9 parts by weight of triphenylphosphine.

(4) (Polyfunctional Epoxy Resin Component B)

(5) A polyfunctional epoxy resin component B was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 40.5 parts by weight of an aromatic polyamine (manufactured by Tokyo Kasei Kogyo Co., Ltd., 4,4′-methylenebis(2-ethyl-6-methylaniline) and 2.1 parts by weight of triphenylphosphine.

(6) (Polyfunctional Epoxy Resin Component C)

(7) A polyfunctional epoxy resin component C was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 27.3 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(8) (Polyfunctional Epoxy Resin Component D)

(9) A polyfunctional epoxy resin component D was prepared by mixing 100 parts by weight of a naphthalene type epoxy resin (manufactured by DIC Corporation, “HP4710”, epoxy equivalent: 180 g/eq, tetrafunctional type (the number of epoxy groups: 4), 1,1′-methylenebis(2,7-diglycidyloxynaphthalene)) with 27.6 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine) and 1.9 parts by weight of triphenylphosphine.

(10) (Polyfunctional Epoxy Resin Component E)

(11) A polyfunctional epoxy (polyfunctional/bifunctional composite type) resin component E was prepared by mixing 50 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 50 parts by weight of a diglycidyl ester of dimer acid (manufactured by Mitsubishi Chemical Corporation, “jER871”, epoxy equivalent: 420 g/eq) and 19.3 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(12) (Polyfunctional Epoxy Resin Component F)

(13) A polyfunctional epoxy resin component F was prepared by mixing 100 parts by weight of a glycidyl amine type aromatic epoxy resin (N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)aniline, Manufactured by Mitsubishi Chemical Corporation, “jER630”, epoxy equivalent: 96 g/eq) with 49.0 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(14) (Polyfunctional Epoxy Resin Component G)

(15) A polyfunctional epoxy resin component G was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 14 parts by weight of an aliphatic polyamine (triethylenetetramine, manufactured by Wako Pure Chemical Industries, Ltd.) and 114 parts by weight of butyl carbitol as a solvent.

(16) (Polyfunctional Epoxy Resin Component H)

(17) A polyfunctional epoxy resin component H was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 5 parts by weight of an imidazole (2-ethyl-4-methylimidazole, manufactured by Wako Pure Chemical Industries, Ltd.) and 105 parts by weight of butyl carbitol as a solvent.

(18) (Polyfunctional Epoxy Resin Component I)

(19) A polyfunctional epoxy resin component I was prepared by mixing 100 parts by weight of a phenol novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER152”, epoxy equivalent: 174 g/eq) with 20 parts by weight of an imidazole (an imidazole-based epoxy adduct curing agent, manufactured by Ajinomoto Fine Techno Co., PN-23) and 120 parts by weight of butyl carbitol as a solvent.

(20) (Polyfunctional Epoxy Resin Component J)

(21) A polyfunctional epoxy resin component J was prepared by mixing 100 parts by weight of a glycidyl amine type aromatic epoxy resin (N,N-bis(oxiranylmethyl)-4-(oxiranylmethoxy)aniline (N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane), manufactured by Mitsubishi Chemical Corporation, “jER604”, epoxy equivalent: 130 g/eq) with 36.5 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(22) (Polyfunctional Epoxy Resin Component K)

(23) A polyfunctional epoxy resin component K was prepared by mixing 100 parts by weight of a bisphenol A novolak type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “jER157S70”, epoxy equivalent: 220 g/eq) with 21.6 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(24) (Polyfunctional Epoxy Resin Component L)

(25) A polyfunctional epoxy resin component L was prepared by mixing 100 parts by weight of a dicyclopentadiene skeleton-containing novolak type epoxy resin (manufactured by DIC Corporation, “HP7200”, epoxy equivalent: 261 g/eq) with 18.2 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(26) (Polyfunctional Epoxy Resin Component M)

(27) A polyfunctional epoxy resin component M was prepared by mixing 100 parts by weight of a dicyclopentadiene skeleton-containing novolak type epoxy resin (manufactured by DIC Corporation, “HP7200HHH”, epoxy equivalent: 286 g/eq) with 16.6 parts by weight of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(28) (Bifunctional Epoxy Resin Component)

(29) A bifunctional epoxy resin component was prepared by mixing 100 parts by weight of a bisphenol A propoxy diglycidyl ether (manufactured by Wako Pure Chemical Industries, Ltd., epoxy equivalent: 228 g/eq) with 20.8 parts of an aromatic polyamine (manufactured by Mitsubishi Chemical Corporation, “jER Cure W”, diethyltoluenediamine).

(30) (Polyester Resin)

(31) A polyester resin solution (manufactured by Arakawa Chemical Industries, Ltd., “Arakyd 7005”, resin concentration: 34.6% by weight) was used.

(32) (Silver Flakes 1 to 5)

(33) Using, as a raw material, an aggregated powder obtained by heating silver nanoparticles (median particle diameter of primary particles: approximately 100 nm), which was prepared in accordance with Examples 1 and 2 of JP-A-2010-229544, at 100° C. for 3 hours to aggregate the silver nanoparticles, a silver flake was prepared by flattening the aggregated powder by a ball mill. The preparation was performed five times (5 lots at 1 lot/day) and the silver flakes prepared at individual lots were taken as silver flakes 1 to 5 and 8.

(34) Characteristics of the silver flakes 1 to 5 and 8 are as follows.

(35) Silver flake 1: average particle diameter (D50) 1.6 μm, BET specific surface area 2.5 m.sup.2/g, tap density 2.6 g/cm.sup.3

(36) Silver flake 2: average particle diameter (D50) 1.2 μm, BET specific surface area 2.7 m.sup.2/g, tap density 2.5 g/cm.sup.3

(37) Silver flake 3: average particle diameter (D50) 4.3 μm, BET specific surface area 1.5 m.sup.2/g, tap density 2.1 g/cm.sup.3

(38) Silver flake 4: average particle diameter (D50) 5.1 μm, BET specific surface area 1.5 m.sup.2/g, tap density 1.6 g/cm.sup.3

(39) Silver flake 5: average particle diameter (D50) 1.5 μm, BET specific surface area 1.8 m.sup.2/g, tap density 2.3 g/cm.sup.3

(40) Silver flake 8: average particle diameter (D50) 1.2 μm, BET specific surface area 3.8 m.sup.2/g, tap density 2.6 g/cm.sup.3

(41) (Silver Flake 6)

(42) Nanomelt Ag-XF301S manufactured by Fukuda Metal Foil & Powder Co., Ltd. was used as silver flake 6.

(43) The silver flake 6 has an average particle diameter (D50) of 4.0 μm, a BET specific surface area of 2.7 m.sup.2/g, and a tap density of 0.8 g/cm.sup.3.

(44) (Silver Flake 7)

(45) Nanomelt Ag-XF301K manufactured by Fukuda Metal Foil & Powder Co., Ltd. was used as silver flake 7.

(46) The silver flake 7 has an average particle diameter (D50) of 6.0 μm, a BET specific surface area of 1.9 m.sup.2/g, and a tap density of 0.6 g/cm.sup.3.

(47) Incidentally, the following will show measurement methods or evaluation methods of various physical properties and characteristics.

(48) (Average Particle Diameter)

(49) The average particle diameter (D50) of the metal flakes is a volume-based median particle diameter measured by using a laser diffraction scattering particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., “Micro Track”).

(50) (BET Specific Surface Area)

(51) After 3 g of a sample was deaerated at 70° C. for 10 minutes, BET specific surface area was determined by a BET single point method by using a specific surface area measuring device (manufactured by Quantachrome Corporation, “Monosorb”).

(52) (Tap Density)

(53) Tap density (15 g/sample volume (cm.sup.3) after tapping) was determined from the sample volume by using a tap density measuring device (manufactured by Shibayama Kagaku Co., Ltd., “SS-DA-2”), after 15 g of a sample was placed in a 20 mL test tube and the tube was allowed to fall 1,000 times with a fall height of 20 mm.

(54) (Resistivity)

(55) A conductive composition was applied to a slide glass by using an applicator and, after dried at 120° C. for 30 minutes, was fired at 200° C. for 90 minutes to form a conductive film having a thickness of 5 μm, and then resistivity was calculated from surface resistance measured by four-point probe method and film thickness measured by a stylus type film thickness meter.

(56) (Bond Strength)

(57) By using a conductive composition, a silicon chip of 3.5 mm×3.5 mm was attached to a copper plate having a thickness of 2 mm and, after drying at 120° C. for 30 minutes, firing was performed at 200° C. for 90 minutes to bond the silicon chip [a silicon chip having films formed by sputtering titanium, platinum, and gold in this order on silicon (bonding surface being gold)] to the copper plate. Thereafter, evaluation was performed by measuring shear strength.

(58) (Thermal Conductivity)

(59) By using a resistivity value measured, thermal conductivity (calculated value) was calculated by using an equation according to the Wiedemann-Franz law: λ=L×T/ρv (λ is thermal conductivity, L is Lorentz number (2.44×10.sup.−8 W.Math.Ω.Math.K.sup.−2), T is absolute temperature (298K), and ρv is resistivity).

(60) As for Examples 2, 7, 10, and 11, the thermal conductivity (measured value) was measured by laser flash by using a cylindrical sample having a thickness of 2 mm and a diameter of 10 mm prepared by further drying the conductive composition at 120° C. for 30 minutes and subsequently firing it at 200° C. for 90 minutes.

Example 1

(61) A conductive composition was obtained by adding 5 parts by weight of the polyfunctional epoxy resin component A and 20 parts by weight of butyl carbitol (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent to 100 parts by weight of the silver flake 1, followed by kneading by a three-roll. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 2

(62) A conductive composition was obtained in the same manner as in Example 1 except that the polyfunctional epoxy resin component A was used in an amount of 10 parts by weight instead of 5 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity, shear strength and thermal conductivity were measured.

Example 3

(63) A conductive composition was obtained in the same manner as in Example 1 except that the polyfunctional epoxy resin component A was used in an amount of 20 parts by weight instead of 5 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 4

(64) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 2 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 5

(65) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 3 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 6

(66) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 4 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 7

(67) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 5 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity, shear strength and thermal conductivity were measured.

Example 8

(68) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 6 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity was measured.

Example 9

(69) A conductive composition was obtained in the same manner as in Example 2 except that 100 parts by weight of the silver flake 7 was used instead of 100 parts by weight of the silver flake 1 in Example 2. Then, for the resulting conductive composition, resistivity was measured.

Example 10

(70) A conductive composition was obtained by adding 10 parts by weight of the polyfunctional epoxy resin component A, 9 parts by weight of a silver nanoparticle (manufactured by Mitsuboshi Belting Ltd., “MDot-SLP”, average particle diameter by electron microscopy observation: 50 nm), and 15 parts by weight of butyl carbitol (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent to 100 parts by weight of the silver flake 1, followed by kneading by a three-roll. Then, for the resulting conductive composition, resistivity, shear strength and thermal conductivity were measured.

Example 11

(71) A conductive composition was obtained in the same manner as in Example 10 except that the polyfunctional epoxy resin component A was used in an amount of 5 parts by weight instead of 10 parts by weight and butyl carbitol was used in an amount of 20 parts by weight instead of 15 parts by weight in Example 10. Then, for the resulting conductive composition, resistivity, shear strength and thermal conductivity were measured.

Example 12

(72) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component B in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 13

(73) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component C in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 14

(74) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component D in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 15

(75) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component E in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 16

(76) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component F in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 17

(77) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component F in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 18

(78) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component F in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 19

(79) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component G in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 20

(80) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component G in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 21

(81) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component G in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 22

(82) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component H in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 23

(83) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component H in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 24

(84) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component H in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 25

(85) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component I in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 26

(86) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component I in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 27

(87) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component I in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 28

(88) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component J in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 29

(89) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component J in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 30

(90) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component J in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 31

(91) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component K in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 32

(92) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component K in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 33

(93) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component K in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 34

(94) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component L in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 35

(95) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component L in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 36

(96) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component L in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 37

(97) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the polyfunctional epoxy resin component M in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 38

(98) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the polyfunctional epoxy resin component M in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 39

(99) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the polyfunctional epoxy resin component M in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 40

(100) A conductive composition was obtained in the same manner as in Example 1 except that 100 parts by weight of the silver flake 8 was used instead of 100 parts by weight of the silver flake 1 in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 41

(101) A conductive composition was obtained in the same manner as in Example 1 except that 100 parts by weight of the silver flake 8 was used instead of 100 parts by weight of the silver flake 1 and the polyfunctional epoxy resin component A was used in an amount of 10 parts by weight instead of 5 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 42

(102) A conductive composition was obtained in the same manner as in Example 1 except that 100 parts by weight of the silver flake 8 was used instead of 100 parts by weight of the silver flake 1 and the polyfunctional epoxy resin component A was used in an amount of 20 parts by weight instead of 5 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Example 43

(103) A conductive composition was obtained in the same manner as in Example 1 except that the polyfunctional epoxy resin component A was used in an amount of 25 parts by weight instead of 5 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Comparative Example 1

(104) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 5 parts by weight of the bifunctional epoxy resin component in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Comparative Example 2

(105) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 10 parts by weight of the bifunctional epoxy resin component in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

Comparative Example 3

(106) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 20 parts by weight of the bifunctional epoxy resin component in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured. Incidentally, it was not able to measure the resistivity because it was too large.

Comparative Example 4

(107) A conductive composition was obtained in the same manner as in Example 1 except that 5 parts by weight of the polyfunctional epoxy resin component A was changed to 28.9 parts by weight of the polyester resin solution (i.e., 10 parts by weight of the polyester resin) and butyl carbitol was changed from 20 parts by weight to 11 parts by weight in Example 1. Then, for the resulting conductive composition, resistivity and shear strength were measured.

(108) The results are shown in Tables 1 to 3. Incidentally, in Tables 1 to 3, “polyfunctional” means an abbreviation of “polyfunctional epoxy resin component”, “bifunctional” means an abbreviation of “bifunctional epoxy resin component”, and “polyester” means an abbreviation of “polyester resin”. Also, in Table 1, the values of thermal conductivity in parentheses are measured values.

(109) TABLE-US-00001 TABLE 1 Silver flake (100 parts by weight) Average Specific (Average particle Silver particle surface Tap diameter) × nanoparticle Resin Shear Thermal diameter area density (Specific surface part by component Resistivity strength conductivity T ype μm m.sup.2/g g/cm.sup.3 area).sup.2 weight Type/part by weight μΩ .Math. cm N W/m .Math. K Example 1 1 1.6 2.5 2.6 10.0 — Polyfunctional A/5 6.5 163 111.9 Example 2 1 1.6 2.5 2.6 10.0 — Polyfunctional A/10 7.2 163 101.0 (47.2) Example 3 1 1.6 2.5 2.6 10.0 — Polyfunctional A/20 31 121 23.5 Example 4 2 1.2 2.7 2.5 8.7 — Polyfunctional A/10 6.8 155 106.9 Example 5 3 4.3 1.5 2.1 9.6 — Polyfunctional A/10 8.1 131 89.8 Example 6 4 5.1 1.5 1.6 11.5 — Polyfunctional A/10 10.7 123 68.0 Example 7 5 1.5 1.8 2.3 4.9 — Polyfunctional A/10 12.8 85  56.8 (33.5) Example 8 6 4.0 2.7 0.8 29.2 — Polyfunctional A/10 16.3 — 44.6 Example 9 7 6.0 1.9 0.6 21.7 — Polyfunctional A/10 14.6 — 49.8 Example 10 1 1.6 2.5 2.6 10.0 9 Polyfunctional A/10 6.3 115 115.4 (49.3) Example 11 1 1.6 2.5 2.6 10.0 9 Polyfunctional A/5 5.5 124 132.2 (56.4) Example 12 1 1.6 2.5 2.6 10.0 — Polyfunctional B/10 9.6 166 75.7 Example 13 1 1.6 2.5 2.6 10.0 — Polyfunctional C/10 6.7 171 108.5 Example 14 1 1.6 2.5 2.6 10.0 — Polyfunctional D/10 7.8 109 93.2 Example 15 1 1.6 2.5 2.6 10.0 — Polyfunctional E/10 15.2 181 47.8

(110) TABLE-US-00002 TABLE 2 Silver flake (100 parts by weight) Average Specific (Average particle Silver particle surface Tap diameter) × nanoparticle Shear Thermal diameter area density (Specific surface part by Resin component Resistivity strength conductivity Type μm m.sup.2/g g/cm.sup.3 area).sup.2 weight Type/part by weight μΩ .Math. cm N W/m .Math. K Example 16 1 1.6 2.5 2.6 10.0 — Polyfunctional F/5 12.5 41 58.2 Example 17 1 1.6 2.5 2.6 10.0 — Polyfunctional F/10 24.1 47 30.2 Example 18 1 1.6 2.5 2.6 10.0 — Polyfunctional F/20 45 119 16.2 Example 19 1 1.6 2.5 2.6 10.0 — Polyfunctional G/5 9.5 23 76.5 Example 20 1 1.6 2.5 2.6 10.0 — Polyfunctional G/10 22.1 73 32.9 Example 21 1 1.6 2.5 2.6 10.0 — Polyfunctional G/20 29.5 231 24.6 Example 22 1 1.6 2.5 2.6 10.0 — Polyfunctional H/5 9.4 42 77.4 Example 23 1 1.6 2.5 2.6 10.0 — Polyfunctional H/10 15.6 52 46.6 Example 24 1 1.6 2.5 2.6 10.0 — Polyfunctional H/20 25.3 72 28.7 Example 25 1 1.6 2.5 2.6 10.0 — Polyfunctional I/5 10.2 44 71.3 Example 26 1 1.6 2.5 2.6 10.0 — Polyfunctional I/10 21.5 73 33.8 Example 27 1 1.6 2.5 2.6 10.0 — Polyfiinctional I/20 36.4 113 20.0 Comparative 1 1.6 2.5 2.6 10.0 — Bifunctional/5 57.0 23 12.8 Example 1 Comparative 1 1.6 2.5 2.6 10.0 — Bifunctional/10 147 64 4.9 Example 2 Comparative 1 1.6 2.5 2.6 10.0 — Bifunctional 20 Impossible 212 — Example 3 to measure Comparative 1 1.6 2.5 2.6 10.0 — Polyester/10 383 123 1.9 Example 4

(111) TABLE-US-00003 TABLE 3 Silver flake (100 parts by weight) Average Specific (Average particle Silver particle surface Tap diameter) × nanoparticle Shear Thermal diameter area density (Specific surface part by Resin component Resistivity strength conductivity Type μm m.sup.2/g g/cm.sup.3 area).sup.2 weight Type/part by weight μΩ .Math. cm N W/m .Math. K Example 28 1 1.6 2.5 2.6 10.0 — Polyfunctional J/5 10.1 74.1 72.0 Example 29 1 1.6 2.5 2.6 10.0 — Polyfunctional J/10 17.2 54.5 42.3 Example 30 1 1.6 2.5 2.6 10.0 — Polyfunctional J/20 82.3 207.1 8.8 Example 31 1 1.6 2.5 2.6 10.0 — Polyfunctional K/5 8.2 103.8 88.7 Example 32 1 1.6 2.5 2.6 10.0 — Polyfunctional K/10 6.5 99.2 111.9 Example 33 1 1.6 2.5 2.6 10.0 — Polyfunctional K/20 58.1 100.2 12.5 Example 34 1 1.6 2.5 2.6 10.0 — Polyfunctional L/5 8.1 85.6 89.8 Example 35 1 1.6 2.5 2.6 10.0 — Polyfunctional L/10 7.0 191.5 103.9 Example 36 1 1.6 2.5 2.6 10.0 — Polyfunctional L/20 25.5 125.2 28.5 Example 37 1 1.6 2.5 2.6 10.0 — Polyfunctional M/5 8.8 120.1 82.6 Example 38 1 1.6 2.5 2.6 10.0 — Polyfunctional M/10 7.7 174.2 94.4 Example 39 1 1.6 2.5 2.6 10.0 — Polyfunctional M/20 30.3 125.7 24.0 Example 40 8 1.2 3.8 2.6 17.3 — Polyfunctional A/5 6.4 92 113.6 Example 41 8 1.2 3.8 2.6 17.3 — Polyfunctional A/10 8.2 125 88.7 Example 42 8 1.2 3.8 2.6 17.3 Polyfunctional A/20 16.5 121 44.1 Example 43 1 1.6 2.5 2.6 10.0 — Polyfunctional A/25 66.4 131.2 11.0

(112) While the invention has been described in detail and with reference to specific embodiments thereof; it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the present invention.

(113) The present application is based on Japanese Patent Application No. 2012-215007 filed on Sep. 27, 2012 and Japanese Patent Application No. 2012-252057 filed on Nov. 16, 2012, and the contents thereof are incorporated herein by reference.

INDUSTRIAL APPLICABILITY

(114) Since the conductive composition of the present invention can realize high conductivity, it can be utilized in various use applications, for example, as a composition for forming wiring, circuits, electrodes, and the like and as a conductive adhesive and the like. Particularly, since the conductive composition can realize high conductivity and heat radiation property without impairing high close contact, it is suitable as a conductive adhesive for bonding two base materials each other.