Curable resin composition, adhesive, imide oligomer, imide oligomer composition, and curing agent

Abstract

An imide oligomer is provided for use in a cured product that has a high glass transition temperature after curing and is excellent in thermal decomposition resistance, adhesiveness, and long-term heat resistance. Also provided are a curable resin composition and an imide oligomer composition each containing the imide oligomer, an adhesive containing the curable resin composition, and a curing agent containing the imide oligomer composition.

Claims

1. A curable resin composition comprising: a curable resin; and an imide oligomer composition, the imide oligomer composition containing an imide oligomer having a structure of the following formula (1-1) and a number average molecular weight of 900 or more and 4,000 or less: ##STR00020## where, in the formula (1-1), A is a tetravalent group of the following formula (2-1) or the following formula (2-2); and in the formula (1-1), B is a divalent group of the following formula (3-1), the formula (2-1) and the formula (2-2) being as follows: ##STR00021## where, in the formula (2-1) and the formula (2-2), * is a binding site; in the formula (2-1), Z is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group that may have an oxygen atom at a binding site; and in the formula (2-1) and the formula (2-2), a hydrogen atom of an aromatic ring may be replaced; the formula (3-1) being as follows: ##STR00022## where, in the formula (3-1), * is a binding site; in the formula (3-1), Y is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group; and in the formula (3-1), a hydrogen atom of an aromatic ring may be replaced; and the imide oligomer composition having an imidization ratio of 70% or higher.

2. The curable resin composition according to claim 1, wherein the imide oligomer composition contains at least one of an imide oligomer of the following formula (4-1), the following formula (4-2), the following formula (4-3), or the following formula (4-4), the formula (4-1), the formula (4-2), the formula (4-3), and the formula (4-4) being as follows: ##STR00023## where, in the formulae (4-1) to (4-4), A is a tetravalent group of the following formula (6-1) or the following formula (6-2); in the formula (4-1), the formula (4-3), and the formula (4-4), each A may be the same or different; in the formulae (4-1) to (4-4), B is a divalent group of the following formula (7-1); in the formula (4-3) and the formula (4-4), each B may be the same or different; in the formula (4-2), X is a hydrogen atom, a halogen atom, or a substituted or unsubstituted monovalent hydrocarbon group; and in the formula (4-4), W is a hydrogen atom, a halogen atom, or a substituted or unsubstituted monovalent hydrocarbon group, the formula (6-1) and the formula (6-2) being as follows: ##STR00024## where, in the formula (6-1) and the formula (6-2), * is a binding site; in the formula (6-1), Z is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group that may have an oxygen atom at a binding site; and in the formula (6-1) and the formula (6-2), a hydrogen atom of an aromatic ring may be replaced, the formula (7-1) being as follows: ##STR00025## where, in the formula (7-1), * is a binding site; in the formula (7-1), Y is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group; in the formula (7-1), a hydrogen atom of an aromatic ring may be replaced.

3. The curable resin composition according to claim 1, wherein the imide oligomer contains no siloxane skeleton in its structure.

4. The curable resin composition according to claim 1, wherein the imide oligomer is an imide oligomer having a melting point of 200° C. or lower.

5. The curable resin composition according to claim 1, wherein a cured product of the curable resin composition has a weight reduction ratio at 330° C. of less than 2.5%.

6. The curable resin composition according to claim 1, which has adhesion force to polyimide of 3.4 N/cm or more.

7. The curable resin composition according to claim 1, wherein a cured product of the curable resin composition has a glass transition temperature of 150° C. or higher.

8. An adhesive comprising the curable resin composition according to claim 1.

9. An imide oligomer composition comprising an imide oligomer having a structure of the following formula (1-1) and a number average molecular weight of 900 or more and 4,000 or less, ##STR00026## where, in the formula (1-1), A is a tetravalent group of the following formula (2-1) or the following formula (2-2); and in the formula (1-1), B is a divalent group of the following formula (3-1), the formula (2-1) and the formula (2-2) being as follows: ##STR00027## where, in the formula (2-1) and the formula (2-2), * is a binding site; in the formula (2-1), Z is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group that may have an oxygen atom at a binding site; and in the formula (2-1) and the formula (2-2), a hydrogen atom of an aromatic ring may be replaced; the formula (3-1) being as follows: ##STR00028## where, in the formula (3-1), * is a binding site; in the formula (3-1), Y is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group; and in the formula (3-1), a hydrogen atom of an aromatic ring may be replaced, the imide oligomer composition having an imidization ratio of 70% or higher.

10. The imide oligomer composition according to claim 9, which contains an imide oligomer of the following formula (4-1), the following formula (4-2), the following formula (4-3), or the following formula (4-4), the formula (4-1), the formula (4-2), the formula (4-3), and the formula (4-4) being as follows: ##STR00029## where, in the formulae (4-1) to (4-4), A is a tetravalent group of the following formula (6-1) or the following formula (6-2); in the formula (4-1), the formula (4-3), and the formula (4-4), each A may be the same or different; in the formulae (4-1) to (4-4), B is a divalent group of the following formula (7-1); in the formula (4-3) and the formula (4-4), each B may be the same or different; in the formula (4-2), X is a hydrogen atom, a halogen atom, or a substituted or unsubstituted monovalent hydrocarbon group; and in the formula (4-4), W is a hydrogen atom, a halogen atom, or a substituted or unsubstituted monovalent hydrocarbon group, the formula (6-1) and the formula (6-2) being as follows: ##STR00030## where, in the formula (6-1) and the formula (6-2), * is a binding site; in the formula (6-1), Z is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group that may have an oxygen atom at a binding site; and in the formula (6-1) and the formula (6-2), a hydrogen atom of an aromatic ring may be replaced, the formula (7-1) being as follows: ##STR00031## where, in the formula (7-1), * is a binding site; in the formula (7-1), Y is a bond, an oxygen atom, or a substituted or unsubstituted divalent hydrocarbon group; in the formula (7-1), a hydrogen atom of an aromatic ring may be replaced.

11. The imide oligomer composition according to claim 9, wherein the imide oligomer contains no siloxane skeleton in its structure.

12. The imide oligomer composition according to claim 9, wherein the imide oligomer has a melting point of 200° C. or lower.

13. The imide oligomer composition according to claim 9, wherein the imide oligomer is formed using an aromatic acid dianhydride having a melting point of 240° C. or lower as a raw material.

14. The imide oligomer composition according to claim 9, which is soluble in an amount of 3 g or more in 10 g of tetrahydrofuran at 25° C.

15. A curing agent comprising the imide oligomer composition according to claim 9.

Description

DESCRIPTION OF EMBODIMENTS

(1) Embodiments of the present invention are specifically described in the following with reference to, but not limited to, examples.

SYNTHESIS EXAMPLE 1

Preparation of Imide Oligomer Composition A

(2) An amount of 34.5 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene (available from Mitsui Fine Chemicals, Inc., “Bisaniline M”) was dissolved in 400 parts by weight of N-methylpyrrolidone (available from Wako Pure Chemical Industries, Ltd., “NMP”). To the obtained solution was added 62.0 parts by weight of 3,4′-oxydiphthalic dianhydride (available from Tokyo Chemical Industry Co., Ltd., “3,4′-ODPA”), followed by stirring at 25° C. for two hours to cause reaction to give an amic acid oligomer solution. N-Methylpyrrolidone was removed from the obtained amic acid oligomer solution under reduced pressure, followed by heating at 300° C. for two hours to give an imide oligomer composition A (imidization ratio: 92%).

(3) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition A contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the following formula (13) and B is a group of the following formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 1,380. The analyses further showed that the imide oligomer composition A contained an imide oligomer of the above formula (4-1) (A is a group of the following formula (13) and B is a group of the following formula (14)) as the imide oligomer having a structure of the formula (1-1).

(4) ##STR00013##

(5) In the formula (13), * is a binding site.

(6) ##STR00014##

(7) In the formula (14), * is a binding site.

SYNTHESIS EXAMPLE 2

Preparation of Imide Oligomer Composition B

(8) An imide oligomer composition B (imidization ratio: 92%) was obtained as in Synthesis Example 1 except that 34.5 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene was changed to 34.5 parts by weight of 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene (available from Mitsui Fine Chemicals, Inc., “Bisaniline P”).

(9) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition B contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the following formula (15)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 1,390. The analyses further showed that the imide oligomer composition B contained an imide oligomer of the above formula (4-1) (A is a group of the above formula (13) and B is a group of the following formula (15)) as the imide oligomer having a structure of the formula (1-1).

(10) ##STR00015##

(11) In the formula (15), * is a binding site.

SYNTHESIS EXAMPLE 3

Preparation of Imide Oligomer Composition C

(12) An imide oligomer composition C (imidization ratio: 91%) was obtained as in Synthesis Example 1 except that 34.5 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene was changed to 29.2 parts by weight of 1,3-bis(3-aminophenoxy)benzene (available from Mitsui Fine Chemicals, Inc., “APB-N”).

(13) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition C contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the following formula (16)). The imide oligomer composition C had a number average molecular weight of 1,310. The analyses further showed that the imide oligomer composition C contained an imide oligomer of the above formula (4-1) (A is a group of the above formula (13) and B is a group of the following formula (16)) as the imide oligomer having a structure of the formula (1-1).

(14) ##STR00016##

(15) In the formula (16), * is a binding site.

SYNTHESIS EXAMPLE 4

Preparation of Imide Oligomer Composition D

(16) An imide oligomer composition D (imidization ratio: 93%) was obtained as in Synthesis Example 1 except that 62.0 parts by weight of 3,4′-oxydiphthalic dianhydride was changed to 104.1 parts by weight of 4,4′-(4,4′-isopropylidenediphenoxy)diphthalic anhydride (available from Tokyo Chemical Industry Co., Ltd.).

(17) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition D contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the following formula (17) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 2,020. The analyses further showed that the imide oligomer composition D contained an imide oligomer of the above formula (4-1) (A is a group of the following formula (17) and B is a group of the above formula (14)) as the imide oligomer having a structure of the formula (1-1).

(18) ##STR00017##

(19) In the formula (17), * is a binding site.

SYNTHESIS EXAMPLE 5

Preparation of Imide Oligomer Composition E

(20) An imide oligomer composition E (imidization ratio: 91%) was obtained as in Synthesis Example 4 except that the amount of 4,4′-(4,4′-isopropylidenediphenoxy)diphthalic anhydride added was changed to 98.9 parts by weight.

(21) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition E contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (17) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 2,520. The analyses further showed that the imide oligomer composition E contained an imide oligomer of the above formula (4-1) (A is a group of the formula (17) and B is a group of the above formula (14)) as the imide oligomer having a structure of the formula (1-1).

SYNTHESIS EXAMPLE 6

Preparation of Imide Oligomer Composition F)

(22) An imide oligomer composition F (imidization ratio: 92%) was obtained as in Synthesis Example 1 except that the amount of 3,4′-oxydiphthalic dianhydride added was changed to 65.1 parts by weight.

(23) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition F contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 1,220. The analyses further showed that the imide oligomer composition F contained an imide oligomer of the above formula (4-1) (A is a group of the above formula (13) and B is a group of the above formula (14)) as the imide oligomer having a structure of the formula (1-1).

SYNTHESIS EXAMPLE 7

Preparation of Imide Oligomer Composition G

(24) An amount of 34.5 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene (available from Mitsui Fine Chemicals, Inc., “Bisaniline M”) was dissolved in 400 parts by weight of N-methylpyrrolidone (available from Wako Pure Chemical Industries, Ltd., “NMP”). To the obtained solution was added 62.0 parts by weight of 3,4′-oxydiphthalic dianhydride (available from Tokyo Chemical Industry Co., Ltd., “3,4′-ODPA”), followed by stirring at 25° C. for two hours to cause reaction to give an amic acid oligomer solution. The amic acid oligomer solution was heated at 180° C. for three hours in N-methylpyrrolidone while removing with a Dean-Stark tube the water generated from imidization, and then N-methylpyrrolidone was removed under reduced pressure. Thus, an imide oligomer composition G (imidization ratio: 23%) was obtained.

(25) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition G contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 1,400. The analyses further showed that the imide oligomer composition G contained an imide oligomer of the above formula (4-1) (A is a group of the above formula (13) and B is a group of the above formula (14)) as the imide oligomer having a structure of the formula (1-1).

SYNTHESIS EXAMPLE 8

Preparation of Imide Oligomer Composition H

(26) An imide oligomer composition H (imidization ratio: 91%) was obtained as in Synthesis Example 4 except that the amount of 4,4′-(4,4′-isopropylidenediphenoxy)diphthalic anhydride added was changed to 78.1 parts by weight.

(27) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition H contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (17) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 4,200.

SYNTHESIS EXAMPLE 9

Preparation of Imide Oligomer Composition I

(28) An imide oligomer composition I (imidization ratio: 91%) was obtained as in Synthesis Example 1 except that the amount of 3,4′-oxydiphthalic dianhydride added was changed to 71.4 parts by weight.

(29) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition I contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 830.

SYNTHESIS EXAMPLE 10

Preparation of Imide Oligomer Composition J

(30) An imide oligomer composition J (imidization ratio: 25%) was obtained as in Synthesis Example 7 except that the amount of 3,4′-oxydiphthalic dianhydride added was changed to 46.5 parts by weight.

(31) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition J contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 4,240.

SYNTHESIS EXAMPLE 11

Preparation of Imide Oligomer Composition K

(32) An imide oligomer composition K (imidization ratio: 25%) was obtained as in Synthesis Example 7 except that the amount of 3,4′-oxydiphthalic dianhydride added was changed to 71.4 parts by weight.

(33) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition K contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 850.

SYNTHESIS EXAMPLE 12

Preparation of Imide Oligomer Composition L

(34) The imide oligomer composition A obtained in Synthesis Example 1 in an amount of 70 parts by weight and the imide oligomer composition G obtained in Synthesis Example 7 in an amount of 30 parts by weight of were mixed in 500 parts by weight of methyl ethyl ketone, followed by removal of the methyl ethyl ketone under reduced pressure to give an imide oligomer composition L (imidization ratio: 71%).

(35) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition L contained an imide oligomer having a structure of the above formula (1-1) (A is a group of the above formula (13) and B is a group of the above formula (14)). The imide oligomer having a structure of the formula (1-1) had a number average molecular weight of 1,390. The analyses further showed that the imide oligomer composition L contained an imide oligomer of the above formula (4-1) (A is a group of the above formula (13) and B is a group of the above formula (14)) as the imide oligomer having a structure of the formula (1-1).

SYNTHESIS EXAMPLE 13

Preparation of Imide Oligomer Composition M

(36) An amount of 24.6 parts by weight of 5-amino-o-cresol was dissolved in 400 parts by weight of N-methylpyrrolidone (available from Wako Pure Chemical Industries, Ltd., “NMP”). To the obtained solution was added 31.0 parts by weight of 3,4′-oxydiphthalic dianhydride (available from Tokyo Chemical Industry Co., Ltd., “3,4′-ODPA”), followed by stirring at 25° C. for two hours to cause reaction to give an amic acid oligomer solution. N-Methylpyrrolidone was removed from the obtained amic acid oligomer solution under reduced pressure, followed by heating at 300° C. for two hours to give an imide oligomer composition M (imidization ratio: 91%).

(37) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition M contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the following formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 650. The analyses further showed that the imide oligomer composition M contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (13) and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

(38) ##STR00018##

(39) In the formula (18), * and ** are each a binding site, and * is a binding site to the hydroxy group in the formula (1-2).

SYNTHESIS EXAMPLE 14

Preparation of Imide Oligomer Composition N

(40) An imide oligomer composition N (imidization ratio: 90%) was obtained as in Synthesis Example 13 except that 24.6 parts by weight of 5-amino-o-cresol was changed to 21.8 parts by weight of 3-aminophenol.

(41) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition N contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the following formula (19)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 630. The analyses further showed that the imide oligomer composition N contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (13) and R is a hydrogen atom) as the imide oligomer having a structure of the formula (1-2).

(42) ##STR00019##

(43) In the formula (19), * is a binding site.

SYNTHESIS EXAMPLE 15

Preparation of Imide Oligomer Composition O

(44) An imide oligomer composition 0 (imidization ratio: 92%) was obtained as in Synthesis Example 13 except that 31.0 parts by weight of 3,4′-oxydiphthalic dianhydride was changed to 52.0 parts by weight of 4,4′-(4,4′-isopropylidenediphenoxy)diphthalic anhydride.

(45) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition O contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (17) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 910. The analyses further showed that the imide oligomer composition O contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (17) and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

SYNTHESIS EXAMPLE 16

Preparation of Imide Oligomer Composition P

(46) An imide oligomer composition P (imidization ratio: 91%) was obtained as in Synthesis Example 13 except that 31.0 parts by weight of 3,4′-oxydiphthalic dianhydrid was changed to 135.0 parts by weight of the imide oligomer composition E obtained in Synthesis Example 5.

(47) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition P contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (17) and Ar is a group of the above formula (18). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 2,960. The analyses further showed that the imide oligomer composition P contained an imide oligomer of the above formula (5-3) (A is a group of the above formula (17), B is a group of the above formula (14), and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

SYNTHESIS EXAMPLE 17

Preparation of Imide Oligomer Composition Q

(48) An imide oligomer composition Q (imidization ratio: 91%) was obtained as in Synthesis Example 13 except that the amount of 5-amino-o-cresol added was changed to 25.9 parts by weight.

(49) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition Q contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 590. The analyses further showed that the imide oligomer composition Q contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (13) and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

SYNTHESIS EXAMPLE 18

Preparation of Imide Oligomer Composition R

(50) An amount of 24.6 parts by weight of 5-amino-o-cresol was dissolved in 400 parts by weight of N-methylpyrrolidone (available from Wako Pure Chemical Industries, Ltd., “NMP”). To the obtained solution was added 31.0 parts by weight of 3,4′-oxydiphthalic dianhydride (available from Tokyo Chemical Industry Co., Ltd., “3,4′-ODPA”), followed by stirring at 25° C. for two hours to cause reaction to give an amic acid oligomer solution. The amic acid oligomer solution was heated at 180° C. for three hours in N-methylpyrrolidone while removing with a Dean-Stark tube the water generated from imidization, and then N-methylpyrrolidone was removed under reduced pressure. Thus, an imide oligomer composition R (imidization ratio: 25%) was obtained.

(51) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition R contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 680. The analyses further showed that the imide oligomer composition R contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (13) and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

SYNTHESIS EXAMPLE 19

Preparation of Imide Oligomer Composition S

(52) An imide oligomer composition S (imidization ratio: 90%) was obtained as in Synthesis Example 13 except that 31.0 parts by weight of 3,4′-oxydiphthalic dianhydride was changed to 180.0 parts by weight of the imide oligomer composition H obtained in Synthesis Example 8.

(53) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition S contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (17) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 4,610.

SYNTHESIS EXAMPLE 20

Preparation of Imide Oligomer Composition T

(54) An imide oligomer composition T (imidization ratio: 90%) was obtained as in Synthesis Example 13 except that the amount of the 5-amino-o-cresol added was changed to 26.9 parts by weight.

(55) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition T contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 490.

SYNTHESIS EXAMPLE 21

Preparation of Imide Oligomer Composition U

(56) An imide oligomer composition U (imidization ratio: 26%) was obtained as in Synthesis Example 18 except that 31.0 parts by weight of 3,4′-oxydiphthalic dianhydride was changed to 180.0 parts by weight of the imide oligomer composition H obtained in Synthesis Example 8.

(57) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition U contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (17) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 4,650.

SYNTHESIS EXAMPLE 22

Preparation of Imide Oligomer Composition V

(58) An imide oligomer composition V (imidization ratio: 23%) was obtained as in Synthesis Example 18 except that the amount of 5-amino-o-cresol added was changed to 26.9 parts by weight.

(59) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition V contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 520.

SYNTHESIS EXAMPLE 23

Preparation of Imide Oligomer Composition W

(60) The imide oligomer composition M obtained in Synthesis Example 13 in an amount of 70 parts by weight and the imide oligomer composition R obtained in Synthesis Example 18 in an amount of 30 parts by weight of were mixed in 500 parts by weight of methyl ethyl ketone, followed by removal of the methyl ethyl ketone under reduced pressure to give an imide oligomer composition W (imidization ratio: 71%).

(61) .sup.1H-NMR, GPC, and FT-IR analyses showed that the imide oligomer composition W contained an imide oligomer having a structure of the above formula (1-2) (A is a group of the above formula (13) and Ar is a group of the above formula (18)). The imide oligomer having a structure of the formula (1-2) had a number average molecular weight of 660. The analyses further showed that the imide oligomer composition W contained an imide oligomer of the above formula (5-1) (A is a group of the above formula (13) and R is a methyl group) as the imide oligomer having a structure of the formula (1-2).

(62) (Solubility)

(63) Each of the imide oligomer compositions obtained in the synthesis examples was dissolved in methyl ethyl ketone (MEK), tetrahydrofuran (THF), and a bisphenol F epoxy resin (available from DIC Corporation, “EPICLON EXA-830CRP”). The solubility was evaluated as “Good (∘)” when the amount of the imide oligomer composition dissolved in the MEK, THF, and bisphenol F epoxy resin, 10 g each, was 3 g or more, “Fair (Δ)” when the amount was 1 g or more and less than 3 g, and “Poor (×)” when the amount was less than 1 g.

(64) For the MEK and THF, a predetermined amount of the imide oligomer composition was added to 10 g of the MEK or THF, followed by stirring using a planetary stirrer. The solubility at 25° C. was then evaluated. For EXA-830CRP, a predetermined amount of the imide oligomer composition was added to 10 g of EXA-830CRP, followed by stirring for one hour with heating at 150° C., then followed by cooling. The solubility at 25° C. was then evaluated.

(65) Table 1 shows the results.

(66) (Melting Point)

(67) The melting point of each of the imide oligomer compositions obtained in the synthesis examples was measured as the endothermic peak temperature using a differential scanning calorimeter (EXTEAR DSC6100 (available from SII NanoTechnology Inc.) at a temperature increase rate of 10° C./min.

(68) Table 1 shows the results.

(69) TABLE-US-00001 TABLE 1 Imide oligomer composition A B C D E F G H I J K L Solubility MEK ○ ○ Δ ○ Δ ○ ○ x x ○ x ○ (Boiling point 80° C.) THF ○ ○ ○ ○ ○ ○ ○ Δ Δ ○ Δ ○ (Boiling point 66° C.) EXA-830CRP ○ ○ ○ ○ ○ ○ ○ x x ○ x ○ Melting point (° C.) 157 167 140 138 138 152 147 143 147 157 137 155 Imide oligomer composition M N O P Q R S T U V W Solubility MEK ○ ○ ○ Δ ○ ○ x ○ ○ ○ ○ (Boiling point 80° C.) THF ○ ○ ○ ○ ○ ○ x ○ ○ ○ ○ (Boiling point 66° C.) EXA-830CRP ○ ○ ○ Δ ○ ○ x ○ ○ ○ ○ Melting point (° C.) 160 149 140 183 155 150 193 150 193 150 155

EXAMPLES 1 TO 24 AND COMPARATIVE EXAMPLES 1 to 10

(70) Curable resin compositions of Examples 1 to 24 and Comparative Examples 1 to 10 were prepared by mixing materials according to the formulations shown in Tables 2 to 8.

(71) <Evaluation>

(72) The curable resin compositions obtained in the examples and the comparative examples were evaluated as follows. Tables 2 to 8 show the results.

(73) (Weight Reduction Ratio at 330° C.)

(74) Each of the curable resin compositions obtained in the examples and the comparative examples was applied to a substrate film and dried to give a curable resin composition film.

(75) The weight reduction ratio (%) at 330° C. of the curable resin composition film was measured using a device for thermogravimetry (available from SII NanoTechnology Inc., “EXTEAR TG/DTA6200”) by increasing the temperature from 30° C. to 400° C. at 10° C./min.

(76) (Glass Transition Temperature)

(77) Each of the curable resin compositions obtained in the examples and the comparative examples was applied to a substrate film and dried to give a curable resin composition film. Curable resin composition films obtained in this manner were stacked and heated at 190° C. for 30 minutes to be cured, whereby a cured product having a thickness of 400 μm was obtained. The glass transition temperature of the obtained cured product was determined as the peak temperature on a tan δ curve obtained when the temperature was increased from 0° C. to 300° C. using a dynamic viscoelasticity measuring apparatus (available from A & D Company, Limited, “RHEOVIBRON DDV-25GP”) at a temperature increase rate of 10° C./min, a frequency of 10 Hz, and a chuck interval of 24 mm. A glass transition temperature of 150° C. or higher was evaluated as “Good (∘)”. A glass transition temperature of 130° C. or higher and lower than 150° C. was evaluated as “Fair (Δ)”. A glass transition temperature of lower than 130° C. was “Poor (×)”.

(78) (Long-Term Heat Resistance)

(79) Each of the curable resin compositions obtained in the examples and the comparative examples was applied to a substrate film and dried to give a curable resin composition film. Polyimide films (available from Du Pont-Toray Co., Ltd., “Kapton V”) each having a thickness of 20 μm were stacked on both surfaces of the obtained curable resin composition film (thickness: 20 μm) and heated at 190° C. for one hour to be cured, followed by heating at 175° C. for 1,000 hours. The laminate of the curable resin composition film and the polyimide films after the heat treatment was placed in an arch shape along a cylinder having a diameter of 5 mm or 3 mm at room temperature. The state of the laminate of the curable resin composition film and the polyimide films was then visually observed.

(80) The long-term heat resistance was evaluated as “Good (∘)” in the case where no crack or fracture was observed at all when the laminate was placed in an arch shape along the cylinder having a diameter of 3 mm, “Fair (Δ)” in the case where no crack or fracture was observed when the laminate was placed in an arch shape along the cylinder having a diameter of 5 mm, but a crack or a fracture was observed when it was placed in an arch shape along the cylinder having a diameter of 3 mm, and “Poor (×)” in the case where a crack or fracture was observed when the laminate was placed in an arch shape along the cylinder having a diameter of 5 mm.

(81) (Adhesiveness)

(82) Each of the curable resin compositions obtained in the examples and the comparative examples was applied to a substrate PET film to a thickness of about 20 μm and dried to give a curable resin composition film. The PET film was removed from the obtained curable resin composition film. Polyimide films (available from Du Pont-Toray Co., Ltd., “Kapton 200H”) each having a thickness of 50 μm were bonded to both surfaces of the adhesive layer using a laminator with heating at 80° C. The laminate was hot pressed under the conditions of 190° C., 3 MPa, and one hour to cure the adhesive layer, and then cut to a specimen having a width of 1 cm.

(83) The obtained specimen was subjected to a T-peel test using a tensile tester (available from Orientec Co., Ltd., “UCT-500”) at a peeling speed of 20 ram/min to measure the adhesion force.

(84) The adhesiveness was evaluated as “Good (∘)” in the case where the adhesion force was 6 N/cm or more, “Fair (Δ)” in the case where the adhesion force was 3.4 N/cm or more and less than 6 N/cm, and “Poor (×)” in the case where the adhesion force was less than 3.4 N/cm.

(85) TABLE-US-00002 TABLE 2 Examples 1 2 3 4 5 6 7 Composition Curable Bisphenol F epoxy resin 100 100 100 100 100 100 100 (parts by resin (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing Imide oligomer composition A 145 — — — — — — agent (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1380) Imide oligomer composition B — 145 — — — — — (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1390) Imide oligomer composition C — — 137 — — — — (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1310) Imide oligomer composition D — — — 211 — — — (imidizaion ratio 93%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 2020) Imide oligomer composition E — — — — 222 — — (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 2520) Imide oligomer composition F — — — — — 132 — (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1220) Imide oligomer composition G — — — — — — 145 (imidizaion ratio 23%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1400) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic Polyimide particles — — — — — — — filler (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 300 300 300 300 300 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 1.4 1.4 1.5 1.2 1.4 1.5 2.0 Glass transition temperature ○ ○ ○ ○ ○ ○ ○ Long-term heat resistance ○ ○ ○ ○ ○ ○ Δ Adhesiveness ○ ○ ○ ○ ○ ○ Δ

(86) TABLE-US-00003 TABLE 3 Examples 8 9 10 11 Composition Curable Bisphenol F epoxy resin 100 100 100 100 (parts by resin (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing Imide oligomer composition A 50 500 — 101 agent (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1380) Imide oligomer composition L — — 145 — (imidizaion ratio 71%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1390) Trialkyltetrahydrophthalic anhydride — — — 22 (available from Mtsubishi Chemical Corporation, “YH-306”) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic Polyimide particles — — — — filler (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 300 500 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 2.1 1.8 1.6 2.0 Glass transition temperature ○ ○ ○ ○ Long-term heat resistance Δ Δ ○ ○ Adhesiveness ○ ○ ○ ○

(87) TABLE-US-00004 TABLE 4 Examples 12 13 14 15 16 17 Composition Curable Bisphenol F epoxy resin 100 100 100 100 100 100 (parts by resin (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing Imide oligomer composition M 163 — — — — — agent (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 650) Imide oligomer composition N — 154 — — — — (imidizaion ratio 90%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 630) lmide oligomer composition O — — 228 — — — (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 910) Imide oligomer composition P — — — 487 — — (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 2960) Imide oligomer composition Q — — — — 148 — (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 590) Imide oligomer composition R — — — — — 163 (imidizaion ratio 25%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 680) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic Polyimide particles — — — — — — filler (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 300 300 300 300 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 1.5 1.6 1.4 1.9 1.6 2.0 Glass transition temperature ○ ○ ○ ○ ○ ○ Long-term heat resistance ○ ○ ○ Δ ○ Δ Adhesiveness Δ Δ Δ ○ Δ Δ

(88) TABLE-US-00005 TABLE 5 Examples 18 19 20 21 Composition Curable Bisphenol F epoxy resin 100 100 100 100 (parts by resin (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing agent Imide oligomer composition M 50 500 — 114 (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 650) Imide oligomer composition W — — 163 — (imidizaion ratio 71%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 660) Diallylbisphenol A — — — 26 (available from Meiwa Plastic Industries, Ltd., “MEH-8000H”) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic Polyimide particles — — — — filler (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 300 500 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 2.2 1.9 1.7 1.9 Glass transition temperature ○ ○ ○ Δ Long-term heat resistance Δ Δ ○ ○ Adhesiveness ○ ○ ○ ○

(89) TABLE-US-00006 TABLE 6 Examples 22 23 24 Composition Curable Bisphenol Aepoxy resin 100 — — (parts by resin (available from DIC Corporation, “EPICLON EXA-850CRP”) weight) Resorcinol epoxy resin — 100 — (available from Nagase ChemteX Corporation, “DENACOL EX-201P”) Phenol novolac epoxy resin — — 100 (available from The Dow Chemical Company, “D.E.N. 431”) Curing agent Imide oligomer composition A 136 323 133 (imidizaion ratio 92%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 1380) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic filler Polyimide particles — — — (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 300 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 1.4 1.3 1.4 Glass transition temperature ○ ○ ○ Long-term heat resistance ○ ○ ○ Adhesiveness ○ ○ ○

(90) TABLE-US-00007 TABLE 7 Comparative Examples 1 2 3 4 5 Composition Curable resin Bisphenol F epoxy resin 100 100 100 100 100 (parts by (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing Imide oligomer composition H 281 — — — — agent (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 4200) Imide oligomer composition I — 126 — — — (imidizaion ratio 91%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 830) Imide oligomer composition J — — 253 — — (imidizaion ratio 25%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 4240) Imide oligomer composition K — — — 126 — (imidizaion ratio 25%, containing an oligomer having a structure of formula (1-1) and a number average molecular weight of 850) Trialkyltetrahydrophthalic anhydride — — — — 73 (available from Mtsubishi Chemical Corporation, “YH-306”) Curing 2,4-Diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic filler Polyimide particles — — — — — (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 500 300 300 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 2.5 3.0 3.3 3.3 3.0 Glass transition temperature ○ ○ ○ ○ ○ Long-term heat resistance x x x x x Adhesiveness x x Δ x ○

(91) TABLE-US-00008 TABLE 8 Comparative Examples 6 7 8 9 10 Composition Curable Bisphenol F epoxy resin 100 100 100 100 100 (parts by resin (available from DIC Corporation, “EPICLON EXA-830CRP”) weight) Curing Imide oligomer composition S 649 — — — — agent (imidizaion ratio 90%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 4610) Imide oligomer composition T — 131 — — — (imidizaion ratio 90%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 490) Imide oligomer composition U — — 651 — — (imidizaion ratio 26%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 4650) Imide oligomer composition V — — — 132 — (imidizaion ratio 23%, containing an oligomer having a structure of formula (1-2) and a number average molecular weight of 520) Diallylbisphenol A — — — — 87 (available from Meiwa Plastic Industries, Ltd., “MEH-8000H”) Curing 2,4-diamino-6-(2′-methylimidazolyl-(1′))-ethyl-s-triazine 5 5 5 5 5 accelerator (available from Shikoku Chemicals Corporation, “2MZ-A”, melting point 248° C. to 258° C.) Organic filler Polyimide particles — — — — — (available from Ube Industries, Ltd., “UIP-S”) Fluidity Hydrophobic fumed silica 5 5 5 5 5 modifier (available from Tokuyama Corporation, “MT-10”) Solvent Methyl ethyl ketone 500 300 300 300 300 (available from Wako Pure Chemical Industries, Ltd., “MEK”) Evaluation Weight reduction ratio at 330° C. (%) 2.8 3.2 3.2 3.5 1.5 Glass transition temperature ○ ○ ○ ○ x Long-term heat resistance x x x x x Adhesiveness x Δ x x ○

INDUSTRIAL APPLICABILITY

(92) The present invention can provide an imide oligomer usable in a cured product that has a high glass transition temperature after curing and is excellent in thermal decomposition resistance, adhesiveness, and long-term heat resistance. The present invention can also provide a curable resin composition and an imide oligomer composition each containing the imide oligomer, an adhesive containing the curable resin composition, and a curing agent containing the imide oligomer composition.