JP5210269B2 - Imide oligomer blend composition - Google Patents

Description

  The present invention relates to an imide oligomer blend composition and a varnish and a cured product thereof, particularly excellent in solvent solubility and solution storage stability, can be cured at a relatively low temperature, and polyimide after heat curing has excellent heat resistance. It has an imide oligomer composition.

  Aromatic polyimide has excellent heat resistance and excellent mechanical and electrical properties, so it can be used in various fields such as space, aviation, electrical / electronic equipment, communication equipment, and office automation equipment. It is the material used in. However, aromatic polyimides have excellent heat resistance and mechanical properties, but once formed, they become insoluble and infusible, so that there is a problem that molding process flexibility is poor.

  Therefore, conventionally, attempts have been widely made to impart moldability to polyimide by using imide oligomers whose ends are modified with various thermal cross-linking agents and heat-curing after molding. As typical examples of such terminal-modified imide oligomers, for example, imide oligomers modified with 4- (2-phenylethynyl) phthalic anhydride have been proposed (for example, see Patent Documents 1 to 3). However, these conventional terminal-modified imide oligomers, for example, dissolve only 20% by weight or less in an amide organic solvent such as N-methyl-2-pyrrolidone at room temperature, and in addition, gelation occurs after several days. There was a problem that the storage stability in an organic solvent was not sufficient. For this reason, it was difficult to use as a varnish in which an imide oligomer was dissolved in an organic solvent at a relatively high concentration.

  On the other hand, in recent years, an oligomer containing 3,3 ′, 4,4′-biphenyltetracarboxylic acid and 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene has been produced by using 4- (2 -Phenylethynyl) It has been reported that an imide oligomer terminal-modified with phthalic anhydride is excellent in solubility in an organic solvent and storage stability in an organic solvent (for example, see Patent Document 4). However, this terminal-modified imide oligomer also requires a high-temperature treatment at 350 ° C. or higher during heat curing. For this reason, for example, when a varnish-like imide oligomer is applied on an electronic component and then cured by heating, there is a possibility that a dimensional change of the substrate may occur. Furthermore, development of an imide oligomer that can be cured at a lower temperature has been desired from the viewpoint of improving production efficiency or burdening the environment.

US Pat. No. 5,567,810 US Pat. No. 5,681,967 US Pat. No. 5,760,168 JP 2007-99969 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and the problems to be solved are excellent in solvent solubility and solution storage stability, can be cured at a relatively low temperature, and can be cured by heating. It is in providing the imide oligomer composition in which the obtained polyimide shows the outstanding heat resistance.

  As a result of intensive studies by the present inventors in view of the problems of the prior art, 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene is contained as a diamine component, and terminal is obtained using ethynylaniline. By mixing the modified imide oligomer and the imide oligomer terminal-modified with 4- (2-phenylethynyl) phthalic anhydride, it is excellent in solvent solubility and solution storage stability, and is primary cured at a relatively low temperature. A possible imide oligomer blend composition was obtained, and it was found that a polyimide resin obtained by heating and curing the composition showed excellent heat resistance, and the present invention was completed.

  That is, the imide oligomer blend composition according to the present invention comprises (A) a terminal-modified imide oligomer represented by the following general formula (1) and (B) a terminal-modified imide oligomer represented by the following general formula (2). The mixing ratio of (A) the terminal-modified imide oligomer represented by the general formula (1) and (B) the terminal-modified imide oligomer represented by the general formula (2) is (A): (B) = 80: 20 to 20:80.

（一般式（１）中、Ｒ１，Ｒ３，Ｒ４は４価の芳香族テトラカルボン酸残基を、Ｒ２は２価の芳香族ジアミン残基を表す。ｍ，ｎは、ｍ＞０，ｎ＞０，ｍ＋ｎ≧１を満たす。）

(In the general formula (1), R1, R3, and R4 represent tetravalent aromatic tetracarboxylic acid residues, and R2 represents a divalent aromatic diamine residue. M and n are m> 0, n>. 0, m + n ≧ 1 is satisfied.)

（一般式（２）中、Ｒ６，Ｒ７は４価の芳香族テトラカルボン酸残基を、Ｒ５，Ｒ８は２価の芳香族ジアミン残基を表す。ｘ，ｙは、ｘ＞０，ｙ≧０，ｘ＋ｙ≧１を満たす。）

(In the general formula (2), R6 and R7 represent tetravalent aromatic tetracarboxylic acid residues, and R5 and R8 represent divalent aromatic diamine residues. X and y are x> 0, y ≧ 0, x + y ≧ 1 is satisfied.)

  Moreover, in the said imide oligomer blend composition, (A) The glass transition temperature Tg of the terminal modified imide oligomer shown by General formula (1) is 120-165 degreeC, (B) The terminal shown by General formula (2) The glass transition temperature Tg of the modified imide oligomer is preferably 120 to 210 ° C.

  In the imide oligomer blend composition, at least one of R1, R3 and R4 in the general formula (1) and R6 and R7 in the general formula (2) is selected from the following aromatic tetracarboxylic acid residues: It is preferable that

  In the imide oligomer blend composition, R2 in the general formula (1) and R5 and R8 in the general formula (2) are preferably at least one selected from the following aromatic diamine residues. is there.

Moreover, the varnish concerning this invention melt | dissolves the said imide oligomer blend composition in an organic solvent, It is characterized by the above-mentioned.
Moreover, the hardened | cured material concerning this invention is obtained by heat-hardening the said imide oligomer blend composition or the said varnish.
In the cured product, the imide oligomer blend composition or the varnish is primarily cured by heating at a temperature of 180 ° C. or higher and lower than 300 ° C. for a predetermined time, and further heated to be constant at a temperature of 300 ° C. or higher and 400 ° C. or lower. It is preferable that it is obtained by second-curing by heating for a period of time.

  According to the present invention, an imide oligomer (A) containing 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene as a diamine component and terminal-modified with ethynylaniline, and 4- (2- Phenylethynyl) Imide oligomer blend composition having excellent solvent solubility and solution storage stability and capable of primary curing at a relatively low temperature by mixing with imide oligomer (B) terminal-modified with phthalic anhydride The polyimide resin obtained by further heat-curing this exhibits excellent heat resistance.

In the imide oligomer blend composition according to the present invention, both imide oligomer components contained in the composition contain 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene as a diamine component,
(A) an imide oligomer represented by the following general formula (1) obtained by terminal modification with ethynylaniline;
(B) It comprises an imide oligomer represented by the following general formula (2) obtained by terminal modification with 4- (2-phenylethynyl) phthalic anhydride, and is represented by (A) the general formula (1). The mixing ratio of the terminal-modified imide oligomer and (B) the terminal-modified imide oligomer represented by the general formula (2) is (A) :( B) = 80: 20 to 20:80. Is.

  R1, R3, R4 in the general formula (1) and R6, R7 in the general formula (2) represent a tetravalent aromatic tetracarboxylic acid residue. The aromatic tetracarboxylic dianhydride used in the present invention is not particularly limited, but examples of suitable aromatic tetracarboxylic acid include pyromellitic anhydride, 4,4′-oxydiphthalic dianhydride, 4,4′-biphthalic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, etc. It is done. These aromatic tetracarboxylic acids may be used alone or in combination of two or more. When these aromatic tetracarboxylic dianhydrides are used, the residues represented by R1, R3, R4 in the general formula (1) and R6, R7 in the general formula (2) are as follows: Become.

  R2 in the general formula (1) and R5 and R8 in the general formula (2) are divalent aromatic diamine residues other than 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene. Indicates a group. The aromatic diamine used in the present invention is not particularly limited, but suitable aromatic diamines include 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfoxide, 1,3-bis (3-aminophenoxy) benzene, 4,4 Examples include '-bis (4-aminophenoxy) biphenyl and 3,3'-bis (3-aminophenoxy) biphenyl. These aromatic diamines may be used alone or in combination of two or more. When these aromatic diamines are used, the residues represented by R2 in the general formula (1) and R5 and R8 in the general formula (2) are as follows.

  In addition, m and n in the general formula (1) and x and y in the general formula (2) are m> 0, n> 0, m + n ≧ 1, or x> 0, y ≧ 0, x + y ≧, respectively. 1 is satisfied.

  In addition, when m + n or x + y exceeds 10 in the imide oligomer of the present invention, the melt viscosity becomes high and thermoforming may be difficult, and therefore it is preferable that 1 ≦ m + n and x + y ≦ 10. Further, 1 ≦ m + n and x + y ≦ 6 are preferable, and 2 ≦ m + n and x + y ≦ 5 are more preferable. When m + n and x + y are within the above ranges, an imide oligomer blend composition particularly excellent in moldability and heat resistance can be obtained.

  Here, in the terminal-modified imide oligomers (A) and (B) represented by the general formulas (1) and (2), a 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene residue is substituted. The n and x of the imide structure to be included are n> 0 and x> 0, respectively. When the terminal-modified imide oligomer (A) does not contain the imide structure, the terminal-modified imide oligomer (A) is hardly dissolved in a solvent and may have poor moldability. On the other hand, when the terminal-modified imide oligomer (B) does not contain the imide structure, the terminal-modified imide oligomer (B) is not easily dissolved in a solvent, and may be inferior in thermoformability or heat resistance of the cured polyimide resin. In addition, in the terminal modified imide oligomer (B), the whole may consist of the said imide structure.

  In the terminal-modified imide oligomer (A) represented by the general formula (1), the imide structure containing an aromatic diamine residue other than 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene. m is m> 0. When the imide oligomer does not contain the imide structure, it may be difficult to dissolve in a solvent, or the cured polyimide resin may have poor heat resistance. On the other hand, the terminal-modified imide oligomer (B) represented by the general formula (2) has an imide structure containing an aromatic diamine residue other than 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene. y is y ≧ 0, and the imide oligomer may or may not be included in the total amount of the imide oligomer.

  In addition, it is preferable that the imide oligomer (A) shown by the said General formula (1) is the range whose glass transition temperature Tg is 120-165 degreeC. If the glass transition temperature Tg is lower than 120 ° C., the heat resistance of the cured polyimide resin may be inferior. If it is higher than 165 ° C., the glass resin cannot be sufficiently melted during thermoforming, resulting in poor thermoformability. There is a case.

  Moreover, it is preferable that the terminal modified imide oligomer (B) shown by the said General formula (2) is the range whose glass transition temperature Tg is 120-210 degreeC. When the glass transition temperature Tg is lower than 120 ° C., the glass transition temperature Tg becomes difficult to dissolve in a solvent, and thermoforming property or heat resistance of the cured polyimide resin may be inferior. On the other hand, if the glass transition temperature Tg is higher than 210 ° C., the glass transition temperature Tg cannot be sufficiently melted during thermoforming, and the thermoformability may be inferior.

  In the imide oligomer blend composition according to the present invention, the terminal-modified imide oligomer (A) represented by the general formula (1) and the terminal-modified imide oligomer (B) represented by the general formula (2) The mixing ratio can be (A) :( B) = 80: 20 to 20:80, but (A) :( B) = 50: 50 to 80:20 is particularly preferable. If the proportion of the terminally modified imide oligomer (A) in the total amount of the blend composition is less than 0.2, it cannot be cured at a low temperature, a high temperature treatment is required during heat curing, and the moldability may be poor. is there. On the other hand, if the proportion of the terminal-modified imide oligomer (B) is less than 0.2, the heat-cured polyimide resin may be inferior in heat resistance.

The terminal-modified imide oligomers (A) and (B) used in the present invention can be prepared, for example, by the following steps (1) and (2).
(1) An amic acid oligomer or an imide oligomer is prepared by mixing an aromatic diamine and an aromatic tetracarboxylic dianhydride in a solvent and performing a polycondensation reaction.
(2) Subsequently, by reacting the amic acid oligomer or imide oligomer obtained in (1) with ethynylaniline or 4- (2-phenylethynyl) phthalic anhydride, an ethynyl group or phenylethynyl is added to the terminal. Add a group.

  Here, in the case of the terminal-modified imide oligomer (A), it is necessary to use 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene in the aromatic diamine, and 15 mol in the total amount of the aromatic diamine. % Or less is preferable. When the blending ratio of 9,9'-bis (4- (4-aminophenoxy) phenyl) fluorene is more than 15 mol%, the melt viscosity of the imide oligomer blend composition becomes high and the moldability may be inferior.

  On the other hand, in the terminal-modified imide oligomer (B), it is necessary to use 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene as the aromatic diamine used in the step (1). In addition, 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene is preferably 50 mol% or more in the total amount of aromatic diamine. When the blending ratio of 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene is less than 50 mol%, the polyimide resin obtained by heat curing the imide oligomer blend composition is inferior in heat resistance. There is a case.

  Moreover, about another aromatic diamine and aromatic tetracarboxylic dianhydride, arbitrary compounds can be used individually or in combination as appropriate.

  Examples of the solvent used in the polycondensation reaction include N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N-methylcaprolactam, and γ-butyrolactone (GBL). And aprotic solvents such as cyclohexanone. These solvents may be used alone or in combination of two or more.

  In addition, when a polymerization reaction is performed in an aprotic solvent as exemplified above, an amic acid oligomer is obtained. This amic acid oligomer can be dehydrated from an amide moiety and a carboxylic acid moiety by, for example, adding an imidizing agent at a low temperature (about 0 to 140 ° C.) or heating to reflux at a high temperature (about 140 to 275 ° C.). -It can be cyclized (imidized) to give an imide oligomer.

  In the step (2), in the case of the terminal-modified imide oligomer (A), the amino group of ethynylaniline is converted to an imide oligomer chain by reacting the amic acid oligomer or imide oligomer obtained in (1) with ethynylaniline. An imide bond is formed by condensation with any terminal dicarboxylic acid group, and an ethynyl group is added to the terminal. On the other hand, in the case of the terminal-modified imide oligomer (B), 4- (2-phenylethynyl) phthalic anhydride is reacted by reacting the amic acid oligomer or imide oligomer with 4- (2-phenylethynyl) phthalic anhydride. The acid anhydride group of the acid is condensed with an arbitrary amino group at the end of the imide oligomer chain to form an imide bond, and a phenylethynyl group is added to the end. Since the ethynyl group or the phenylethynyl group added to the terminal in the step (2) forms a crosslinked structure with each other by heating, the thermosetting property can be imparted to the imide oligomer.

  Here, the amount of ethynylaniline or 4- (2-phenylethynyl) phthalic anhydride added in the above step (2) may be appropriately adjusted according to the equivalent of the reactive amino group or carboxyl group, In this case, the amount may be about 1.1 to 2.0 times (mole) with respect to the imide ring of the imide oligomer.

  The reaction in the above step (2) can be carried out continuously with the step (1). Usually, both steps (1) and (2) are carried out in the state of an amic acid oligomer and finally converted into an imide oligomer. And convert. That is, the addition reaction of ethynylaniline or 4- (2-phenylethynyl) phthalic anhydride in the step (2) is performed in the state of the amic acid oligomer obtained in the step (1), followed by, for example, low temperature (about 0 It is dehydrated and cyclized (imidized) by adding an imidizing agent at ˜140 ° C. or by heating to reflux at a high temperature (about 140 to 275 ° C.) to obtain an imide oligomer. Here, it is preferable to perform imidization at a low temperature from the viewpoint of preventing reverse reaction due to heating and evaporation of ethynylaniline.

  The terminal-modified imide oligomers (A) and (B) obtained as described above can be mixed with the solution after the reaction as it is to obtain an imide oligomer blend composition. Alternatively, for example, the solution after completion of the reaction is poured into a large amount of water with stirring, isolated by filtration, and then dried at about 100 ° C. to form each of the powdered imide oligomers, which are in a powder state It can also be mixed to make an imide oligomer blend composition.

  Moreover, the imide oligomer blend composition of this invention can be used as a solution composition (varnish) which melt | dissolved the mixed powder obtained above in the suitable solvent as needed. In particular, since the imide oligomer of the present invention has high solubility in a solvent and excellent solution storage stability, it can be stably stored for a long period of time as a relatively high concentration varnish. As the solvent used for the varnish, for example, amide solvents such as N-methyl-2-pyrrolidone (NMP) and N, N-dimethylacetamide (DMAc) can be preferably used. In addition, the compounding quantity of the terminal modified imide oligomer blend composition mix | blended in a varnish is although it does not specifically limit, 30 mass% or more is preferable in a varnish whole quantity, and 45 mass% or more is more preferable.

  In addition, the imide oligomer blend composition or varnish obtained as described above is a polyimide resin having excellent heat resistance by being cured by heating alone or impregnated in a fibrous reinforcing material such as carbon fiber. It can be. In particular, when used as a varnish, it can be easily molded, and impregnation into a fibrous reinforcing material or the like can also be performed relatively easily.

  In heating and curing the imide oligomer blend composition, the heating temperature and the heating time can be appropriately adjusted according to the desired physical properties of the polyimide resin. In particular, the imide oligomer blend composition according to the present invention has a relatively low curing temperature and initiates primary curing at about 180-300 ° C. Further, by performing secondary curing at 300 to 400 ° C., a polyimide resin having more excellent heat resistance and the like can be obtained. More specifically, for example, by preliminarily heating at a temperature of about 120 to 160 ° C. for a predetermined time, the imide oligomer is thermally melted, and then heated at a temperature of 180 to 300 ° C. for a predetermined time to perform primary curing. After that, a cured polyimide resin excellent in heat resistance and the like can be obtained by heating for a certain time at a temperature of 300 ° C. or higher and 400 ° C. or lower for secondary curing. In addition, the heat resistance of a polyimide resin hardened | cured material usually improves by raising the heating temperature in each heating process, or lengthening a heating time.

  In addition, what is necessary is just to perform manufacture of the polyimide resin molded object using the imide oligomer blend composition or varnish of this invention according to a well-known method. For example, the powder of the imide oligomer blend composition of the present invention is filled in a mold and heated and compression molded at 180 to 300 ° C. and about 0.5 to 5 MPa for about 1 to 12 hours to obtain a primary molded product. be able to. Subsequently, a polyimide resin molded article excellent in heat resistance and mechanical properties can be obtained by heat compression molding at 300 ° C. to 400 ° C. and about 0.5 to 5 MPa for about 1 to 5 hours. Further, for example, a varnish containing the imide oligomer blend composition of the present invention is impregnated into a fibrous reinforcing material such as carbon fiber, and dried by heating at 50 to 120 ° C. for about 1 to 5 hours, and further under pressure, 180 to 350. The fiber-containing composite of polyimide resin can be obtained by heating at about 0 to about 5 hours. Also, for example, the solution of the imide oligomer blend composition of the present invention is applied onto a support having good peelability such as a glass plate, and heated at 180 to 350 ° C. for about 1 to 12 hours to obtain a polyimide resin film. Can be obtained.

Hereinafter, the present invention will be described in more detail based on the description of Examples, but the present invention is not limited to these Examples.
In addition, about the minimum melt viscosity of the imide oligomer blend composition obtained by each Example and the comparative example, the glass transition temperature of a hardened | cured material, and 5% weight reduction temperature, respectively, AR2000 type | mold rheometer (made by TA Instruments company), Measurement was performed using a DSC-6200 type differential scanning calorimeter (made by SII Nanotechnology) and a TG / DTA6300 type thermogravimetric analyzer (made by SII Nanotechnology).

First, the present inventors prepared terminal-modified imide oligomers (A) to (C) shown below, and evaluated blend compositions obtained by mixing these imide oligomers.
Terminal-modified imide oligomer (A1)
Into a three-necked 300 mL flask equipped with a thermometer, a stirrer, and a nitrogen introduction tube was added 4.911 g (16.8 mmol) of 1,3-bis (3-aminophenoxy) benzene and 33.93 mL of N, N-dimethylacetamide. In addition, after dissolution, 0.639 g (1.2 mmol) of 9,9-bis (4- (4-aminophenoxy) phenyl) fluorene was added and dissolved. Thereafter, 7.445 g (24 mmol) of oxydiphthalic acid was added and dissolved. The mixture was stirred at room temperature for 1.5 hours under a nitrogen stream to produce an amic acid oligomer. Thereafter, 1.546 g (13.2 mmol) of ethynylaniline was added, and the mixture was stirred at room temperature for 1 hour under a nitrogen stream to denature the ends. Thereafter, 7.899 g of acetic anhydride and 6.120 g of pyridine were added and stirred for 2 hours to effect imide bonding. The reaction solution was poured into 200 mL of ion exchange water and stirred for 30 minutes, and then the deposited powder was filtered under reduced pressure. Further, the filtered powder was washed by stirring with 100 mL of methanol for 30 minutes, and the powder obtained by filtration was dried under reduced pressure at 60 ° C. for 1 day to obtain a terminal-modified imide oligomer (A1). In addition, the glass transition temperature Tg of the terminal modified imide oligomer (A1) obtained above was 156 ° C.

Terminal-modified imide oligomer (A2)
The terminal-modified imide oligomer (A2) was synthesized in the same manner as described above except that 4,4′-diaminodiphenyl ether was used instead of 1,3-bis (3-aminophenoxy) benzene. ) In addition, the glass transition temperature Tg of the terminal modified imide oligomer (A2) obtained was 160 ° C.

Terminal-modified imide oligomer (B1)
In a three-necked 100 mL flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube, 4.261 g (8 mmol) of 9,9-bis (4- (4-aminophenoxy) phenyl) fluorene and N-methyl-2-pyrrolidone 17.3 mL was added and dissolved. Thereafter, 1.177 g (4 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added and dissolved. The mixture was stirred for 1.5 hours at room temperature, 1.5 hours at 60 ° C., and 1 hour at room temperature under a nitrogen stream, and 1.986 g (8 mmol) of 4-phenylethynylphthalic anhydride was added to the reaction mixture. The mixture was stirred at room temperature for 18 hours to denature the ends. Thereafter, the mixture was stirred at 175 ° C. for 5 hours to allow imide bonding. After cooling this reaction liquid, it poured into 200 mL ion-exchange water, and stirred for 30 minutes, Then, the depositing powder was filtered under reduced pressure. Further, the filtered powder was washed by stirring with 100 mL of methanol for 30 minutes, and the powder obtained by filtration was dried under reduced pressure at 60 ° C. for 1 day to obtain a terminal-modified imide oligomer (B1). In addition, the glass transition temperature Tg of the terminal modified imide oligomer (B1) obtained above was 205 ° C.

Terminal-modified imide oligomer (B2)
In the terminal-modified imide oligomer (B1), benzophenone-3,4,3 ′, 4′-tetracarboxylic dianhydride is used instead of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride The terminal-modified imide oligomer (B2) was obtained in the same manner. In addition, the glass transition temperature Tg of the obtained terminal modified imide oligomer (B2) was 160 degreeC.

Terminal-modified imide oligomer (C1)
1.462 g (0.5 mmol) of 1,3-bis (3-aminophenoxy) benzene and 13.9 mL of N-methyl-2-pyrrolidone in a three-necked 100 mL flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube Were added and dissolved, and 0.541 g (0.5 mmol) of 1,3-diaminobenzene was further added and dissolved. Thereafter, 1.471 g (0.5 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was added and dissolved. The mixture was stirred for 1.5 hours at room temperature, 1.5 hours at 60 ° C., and 1 hour at room temperature under a nitrogen stream, and 2.482 g (1 mmol) of 4-phenylethynylphthalic anhydride was added to the reaction solution, The mixture was stirred at room temperature for 18 hours to denature the ends. Thereafter, the mixture was stirred at 175 ° C. for 5 hours to allow imide bonding. After cooling this reaction liquid, it poured into 200 mL ion-exchange water, and stirred for 30 minutes, Then, the depositing powder was filtered under reduced pressure. Further, the filtered powder was washed by stirring with 100 mL of methanol for 30 minutes, and the powder obtained by filtration was dried under reduced pressure at 60 ° C. for 1 day to obtain a terminal-modified imide oligomer (C1). In addition, the glass transition temperature Tg of the terminal modified imide oligomer (C1) obtained above was 120 ° C.

Example 1
1.35 g of the terminal-modified imide oligomer (A1) and 0.45 g of the terminal-modified imide oligomer (B1) obtained above were added to 4.2 mL of N-methyl-2-pyrrolidone and dissolved. The solution was poured into 200 mL of ion exchange water and stirred for 30 minutes, and then the precipitated powder was filtered under reduced pressure. Further, the filtered powder was washed by stirring with 100 mL of methanol for 30 minutes, and the powder obtained by filtration was dried under reduced pressure at 60 ° C. for 1 day to obtain an imide oligomer blend composition of Example 1.

  The imide oligomer blend composition of Example 1 was soluble in NMP and DMAc solvent at 45% by weight at room temperature, and no gelation was observed after one month. The minimum melt viscosity of this imide oligomer blend composition was 47,600 poise (264 ° C.). Moreover, it was confirmed that this imide oligomer composition starts primary curing by heating at about 250 ° C. under pressure to form a film. This imide oligomer blend composition was heated at 260 ° C. for 1 hour by hot pressing and then put into an oven at 360 ° C. for 1 hour. The film-like cured product had a glass transition temperature of 312 ° C. and a 5% weight loss temperature. It was 553 ° C.

Example 2
In the same manner as in the imide oligomer blend composition of Example 1, 1.35 g of the terminal modified imide oligomer (A2) and 0.45 g of the terminal modified imide oligomer (B2) were blended, and the imide oligomer blend composition of Example 2 was blended. Got.

  The imide oligomer blend composition of Example 2 was soluble in NMP and DMAc solvent at 45% by weight at room temperature, and no gelation was observed after one month. The minimum melt viscosity of this imide oligomer blend composition was 56,200 poise (270 ° C.). Moreover, it was confirmed that this imide oligomer composition starts primary curing by heating at about 250 ° C. under pressure to form a film. This imide oligomer blend composition was heated at 260 ° C. for 1 hour by hot pressing and then put into an oven at 360 ° C. for 1 hour. The film-like cured product had a glass transition temperature of 310 ° C. and a 5% weight loss temperature. It was 545 ° C.

Comparative Example 1
1.5 g of the terminal-modified imide oligomer (A1) and 0.5 g of the terminal-modified imide oligomer (C1) obtained above were added to 4.7 mL of N-methyl-2-pyrrolidone and dissolved. The solution was poured into 200 mL of ion exchange water and stirred for 30 minutes, and then the precipitated powder was filtered under reduced pressure. Further, the filtered powder was washed by stirring with 100 mL of methanol for 30 minutes, and the powder obtained by filtration was dried under reduced pressure at 60 ° C. for 1 day to obtain an imide oligomer blend composition of Comparative Example 1.

  The imide oligomer blend composition of Comparative Example 1 was not soluble in NMP and DMAc solvents at room temperature. The minimum melt viscosity of this imide oligomer blend composition was 490 poise (253 ° C.). Moreover, even if this imide oligomer composition was heated at about 250 ° C. under pressure, it did not harden and no film was formed. This imide oligomer blend composition was heated at 260 ° C. for 1 hour by hot pressing and then put into an oven at 360 ° C. for 1 hour. The film-like cured product had a glass transition temperature of 288 ° C. and a 5% weight loss temperature. It was 549 ° C.

  From the above results, both imide oligomer (A1) or (A2) containing 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene as a diamine component and terminal-modified with ethynylaniline, 4- The imide oligomer blend composition of Examples 1 and 2 obtained by mixing the imide oligomer (B1) or (B2) terminal-modified with (2-phenylethynyl) phthalic anhydride was added to NMP and DMAc solvent. Since it was soluble at 45% by weight at room temperature and no gelation was observed after one month, it was found that the solvent was excellent in solvent solubility and solution storage stability. Moreover, since the film was formed by heating the obtained imide oligomer blend composition at 250 ° C. under pressure, it was confirmed that primary curing occurred at a relatively low temperature. Furthermore, the polyimide resin film obtained by heat-curing at a high temperature had a glass transition temperature of 300 ° C. or higher and a 5% weight loss temperature of about 550 ° C., which was excellent in heat resistance.

  On the other hand, ethynylaniline terminal-modified imide oligomer (A1) and 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene are not included as diamine components, and 4- (2-phenylethynyl) phthalic anhydride The imide oligomer blend composition of Comparative Example 1 obtained by mixing with the terminal-modified imide oligomer (C1) could not be dissolved in NMP or DMAc at room temperature. Further, no curing reaction occurred even when heated at 250 ° C. under pressure. Furthermore, in the polyimide resin film obtained by heat curing at a high temperature, both the glass transition temperature and the 5% weight loss temperature were slightly inferior compared with the case where the imide oligomer blend composition of Examples 1 and 2 was used. .

In order to examine the mixing ratio of the terminal-modified imide oligomers (A) and (B) , the present inventors will examine the mixing ratio of the terminal-modified imide oligomers (A) and (B). Various imide oligomer blend compositions prepared by mixing the terminal-modified imide oligomer (B1) at respective ratios shown in Table 1 below were prepared and evaluated. The evaluation results are also shown in Table 1. The evaluation criteria are as follows.

(1) Solvent solubility The imide oligomer blend composition of each test example was attempted to be dissolved in NMP and DMAc solvent.
A: Soluble in NMP and DMAc solvent at 40% by weight or more at room temperature.
X: It was not soluble in NMP and DMAc solvent at 40% by weight or more at room temperature.
(2) Solution storage stability About the imide oligomer blend composition soluble in NMP and DMAc solvent in said (1), the state after 1-month storage at room temperature was confirmed.
A: No gel was formed after storage for 1 month.
X: A gel formed after storage for 1 month.

(3) Low-temperature curability About the imide oligomer blend composition of each test example, the temperature which hardening | curing starts was measured by heating gradually.
A: Curing started at a temperature of 180 to 300 ° C.
X: Curing was started at a temperature of 300 ° C. or higher.
(4) Heat resistance of polyimide resin after heat curing Film-like cured product obtained by heating the imide oligomer blend composition of each test example at 260 ° C. for 1 hour by hot pressing and then putting it in an oven at 360 ° C. for 1 hour The glass transition temperature was measured.
(Double-circle): The glass transition temperature was 300 degreeC or more.
(Circle): Glass transition temperature was 250-300 degreeC.
X: Glass transition temperature was less than 250 degreeC.

  As shown in Table 1 above, Comparative Example 2 using the imide oligomer (A1) terminal-modified with ethynylaniline alone had a low glass transition temperature after heat curing and was inferior in heat resistance. On the other hand, an imide oligomer (B1) containing 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene as a diamine component and terminal-modified with 4- (2-phenylethynyl) phthalic anhydride alone Comparative Example 4 used in the above did not cure at low temperatures. Similarly, Comparative Example 3 in which the terminal-modified imide oligomer (A1) and the terminal-modified imide oligomer (B1) were mixed at a ratio of (A) :( B) = 10: 90 was not cured at a low temperature.

  On the other hand, the imide oligomer of Examples 3-7 which mixed terminal modification imide oligomer (A1) and terminal modification imide oligomer (B1) in the ratio of (A) :( B) = 80: 20-20: 80. The blend composition had low temperature curability and was excellent in the heat resistance of the resin. In particular, in the imide oligomer blend compositions of Examples 5 to 7 mixed at a ratio of (A) :( B) = 50: 50 to 20:80, both the low temperature curability and the heat resistance of the resin are very excellent. It was a thing.

Glass transition temperature Tg of terminal-modified imide oligomers (A) and (B)
Subsequently, the inventors of the present invention used the terminal-modified imide oligomer (A) represented by the general formula (1) and the terminal-modified imide oligomer (B) represented by the general formula (2) for each suitable glass transition temperature Tg. Study was carried out.

For the terminal-modified imide oligomer (A), various terminal-modified imides in which the ratio of m and n in each imide structure in the terminal-modified imide oligomer (A1) is changed to the ratio shown in Table 2 and the glass transition temperature Tg is changed. The oligomer and the terminal-modified imide oligomer (B1) were blended at a mixing ratio of (A) :( B) = 25: 75, and various evaluations were performed on the obtained imide oligomer blend composition.
Moreover, about terminal modified imide oligomer (B), the ratio of x and y of each imide structure in the said terminal modified imide oligomer (B1) was changed into the ratio shown in Table 3, and various terminal which changed glass transition temperature Tg. The imide oligomer and the terminal-modified imide oligomer (A1) were blended at a mixing ratio of (A) :( B) = 25: 75, and the obtained imide oligomer blend composition was evaluated.
The evaluation results of the various imide oligomer blend compositions obtained above are also shown in Tables 2 and 3. The evaluation criteria are as follows.

(1) Solvent solubility The imide oligomer blend composition of each test example was attempted to be dissolved in NMP and DMAc solvent.
A: Soluble in NMP and DMAc solvent at 40% by weight or more at room temperature.
X: It was not soluble in NMP and DMAc solvent at 40% by weight or more at room temperature.
(2) Thermoformability The imide oligomer blend composition of each test example was heated by a hot press at 260 ° C. for 1 hour, and the taken out cured product was evaluated.
(Double-circle): The imide oligomer was fully melt | dissolved and the film color was also uniform.
X: The imide oligomer was not sufficiently melted, the powdery substance remained, and the film was not formed.

(3) Heat resistance of polyimide resin after heat curing Film-like cured product obtained by heating the imide oligomer blend composition of each test example at 260 ° C. for 1 hour with a hot press and then placing it in an oven at 360 ° C. for 1 hour The glass transition temperature was measured.
(Double-circle): The glass transition temperature was 300 degreeC or more.
(Circle): Glass transition temperature was 250-300 degreeC.
X: Glass transition temperature was less than 250 degreeC.

  As shown in Table 2 above, Examples 6, 8, and 9 obtained using the terminal-modified imide oligomer (A) having a glass transition temperature of 156 to 162 ° C. obtained by changing the m and n ratios, respectively. The imide oligomer blend composition was excellent in any of solvent solubility, thermoformability, and resin heat resistance.

  On the other hand, in the imide oligomer blend composition of Comparative Example 5 using the terminal-modified imide oligomer (A) having a glass transition temperature of 169 ° C., it does not melt sufficiently at the time of thermoforming and remains in a powder form, I found out that there was a problem. Further, the imide oligomer blend composition of Comparative Example 6 using a terminal-modified imide oligomer (A) in which n is zero and does not contain 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene is solvent-soluble. Was inferior. From these results, it can be said that it is preferable to use a terminal-modified imide oligomer (A) containing 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene and having a glass transition temperature Tg of 165 ° C. or lower. . Moreover, it is thought that the range of 120 to 165 degreeC is more preferable for the glass transition temperature Tg of a terminal modification imide oligomer (A) from a viewpoint of preventing the resin heat resistance fall after heat-curing.

  As shown in Table 3 above, in the imide oligomer blend compositions of Examples 6 and 10-12 using the terminal-modified imide oligomer (B) having a glass transition temperature of 158 to 205 ° C., solvent solubility, moldability, The resin heat resistance was excellent.

In contrast, the imide oligomer blend of Comparative Example 7 obtained by using a terminal-modified imide oligomer (B) in which x is zero and does not contain 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene The composition was inferior in all of solvent solubility, moldability, and resin heat resistance. From these results, the terminal-modified imide oligomer (B) contains 9,9′-bis (4- (4-aminophenoxy) phenyl) fluorene and has a glass transition temperature Tg of 210 ° C. or lower ( It can be said that it is preferable to use B). Moreover, it is thought that the range whose glass transition temperature Tg of a terminal modified imide oligomer (B) is 120 to 210 degreeC is more preferable from a viewpoint of preventing the resin heat resistance fall after heat-curing.

Claims (7)

(A) a terminal-modified imide oligomer represented by the following general formula (1);
(B) including an imide oligomer component composed of a terminal-modified imide oligomer represented by the following general formula (2),
(A) The mixing ratio of the terminal-modified imide oligomer represented by the general formula (1) and the terminal-modified imide oligomer represented by the general formula (2) is (A) :( B) = 80: 20. Imide oligomer blend composition characterized by being 20:80.

(In the general formula (1), R1, R3, and R4 represent tetravalent aromatic tetracarboxylic acid residues, and R2 represents a divalent aromatic diamine residue. M and n are m> 0, n>. 0, m + n ≧ 1 is satisfied.)

(In the general formula (2), R6 and R7 represent tetravalent aromatic tetracarboxylic acid residues, and R5 and R8 represent divalent aromatic diamine residues. X and y are x> 0, y ≧ 0, x + y ≧ 1 is satisfied.)   (A) The glass transition temperature Tg of the terminal-modified imide oligomer represented by the general formula (1) is 120 to 165 ° C., and (B) the glass transition temperature Tg of the terminal-modified imide oligomer represented by the general formula (2) is 120. The imide oligomer blend composition according to claim 1, wherein the composition is -210 ° C. 2. R1, R3, R4 in the general formula (1) and R6, R7 in the general formula (2) are at least one selected from the following aromatic tetracarboxylic acid residues: The imide oligomer blend composition described.

The imide oligomer blend composition according to claim 1, wherein R2 in the general formula (1) and R5 and R8 in the general formula (2) are at least one selected from the following aromatic diamine residues. object.

  A varnish obtained by dissolving the imide oligomer blend composition according to claim 1 in an organic solvent.   A cured product obtained by heat-curing the imide oligomer blend composition according to claim 1 or the varnish according to claim 5. 7. The cured product according to claim 6, wherein the imide oligomer blend composition according to claim 1 or the varnish according to claim 5 is first cured by heating at a temperature of 180 ° C. or higher and lower than 300 ° C. for a predetermined time, and further heated. A cured product obtained by heating at a temperature of 300 ° C. or higher and 400 ° C. or lower for a predetermined time to be secondarily cured.