JP5311982B2 - Imide oligomer and polyimide resin obtained by heat curing this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imide oligomer from which a polyimide resin excellent in thermoformability and excellent in colorless transparency and heat resistance by heat curing the oligomer is obtained. <P>SOLUTION: The imide oligomer has a diamine composition comprising at least one aliphatic diamine selected from (1R,2R)-(+)-1,2-transcyclohexanediamine, (1S,2S)-(-)-1,2-transcyclohexanediamine and 1,4-ciscyclohexanediamine, and is represented by general formula (1), wherein X represents a (1R,2R)-(+)-1,2-transcyclohexanediamine residue, a (1S,2S)-(-)-1,2-transcyclohexanediamine residue or a 1,4-ciscyclohexanediamine residue; Y represents an acid dianhydride residue; Z represents a crosslinking reactive group; and n represents an average polymerization degree of the imide repeating structure and is 1-10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a thermosetting imide oligomer, and more particularly to an imide oligomer that is excellent in thermoformability and can obtain a polyimide resin excellent in colorless transparency and heat resistance by heat curing.

  In recent years, materials that can replace glass in the field of optical components such as optical sensors, solar cells, and transparent displays have been actively studied. Among them, aliphatic polyimide is attracting attention because it has excellent heat resistance and can withstand solder reflow (see, for example, Non-Patent Document 1). However, with regard to moldability, since the organic solvent used in the polymerization is included, the thickness is limited to about 0.25 mm, and the heat resistance is limited to about 300 ° C. (For example, refer nonpatent literature 2).

  In addition, about the color development of a polyimide resin, there exists absorption derived from the chromophore which comes from a composition itself, and if it aims at colorless and transparent, the composition will be restricted to an aliphatic. Or, although attempts have been made to replace hydrogen with fluorine, most of the conventional polyimide resins have a linear molecular structure, so intermolecular stacking occurs and absorption due to intermolecular electron transfer occurs. The generation cannot be controlled (for example, see Non-Patent Document 1).

  On the other hand, as a result of space development in recent years, axially asymmetric biphthalic dianhydride has been researched and developed, and thermosetting imide oligomers having a thermal decomposition temperature of 600 ° C. as structural materials are used in structural materials for rockets and satellites. It is used as a matrix (see, for example, Patent Documents 1 and 2). Since these imide oligomers have a helical structure, it is known that stacking between molecules hardly occurs, an amorphous material, and excellent melting / melting characteristics. However, even in polyimide resins obtained using these helical imide oligomers, sufficient colorless transparency has not been obtained yet.

JP 2000-219741 A US Pat. No. 6,359,107 “Latest Polyimide Fundamentals and Applications” by Ikuo Imai, Rikio Yokota, NTS Publishing “Latest Polyimide Materials and Applied Technologies” Supervised by Masaaki Enomoto, CM Publishing

  The present invention has been made in view of the above-mentioned problems of the prior art, and the problem to be solved is to obtain a polyimide resin which is excellent in thermoformability and is excellent in colorless transparency and heat resistance by heat curing. It is to provide an imide oligomer that can be used.

  As a result of intensive studies by the present inventors in view of the problems of the prior art, an imide oligomer having excellent thermoformability is obtained by using a cyclic diamine having a specific structure as a raw material diamine monomer. The polyimide resin obtained by heat-curing was found to exhibit excellent colorless transparency and heat resistance, and the present invention was completed.

（上記式（１）において、Ｘは（１Ｒ，２Ｒ）−（＋）−１，２−トランスシクロヘキサンジアミン残基、（１Ｓ，２Ｓ）−（−）−１，２−トランスシクロヘキサンジアミン残基、又は１，４−シスシクロヘキサンジアミン残基、Ｙは酸二無水物残基、Ｚはアリルナジック酸無水化物残基、ｎはイミド繰り返し構造の平均重合度で１〜１０である）
That is, the imide oligomer according to the present invention includes (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4. -It has a diamine composition which consists of any one kind of aliphatic diamine selected from cis cyclohexane diamine, and is represented by following General formula (1).

(In the above formula (1), X is a (1R, 2R)-(+)-1,2-transcyclohexanediamine residue, a (1S, 2S)-(−)-1,2-transcyclohexanediamine residue, Or 1,4-ciscyclohexanediamine residue, Y is an acid dianhydride residue, Z is an allyl nadic acid anhydride residue , and n is an average degree of polymerization of an imide repeating structure of 1 to 10.

Also, in the imide oligomer, the average degree of polymerization n of the imide repeat structure is 1 to 5, respectively, it is preferable and the number average molecular weight of the entire imide oligomer is 8000 or less.

In the imide oligomer, the acid anhydride residue represented by Y in the general formula (1) is 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2.2. ] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1 , 2-dicarboxylic acid dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-biphthalic dianhydride, 3,3', 4,4'-diphenylsulfonic dianhydride , 4,4 '-(hexa Fluoroisopyridene) Diphthalic dianhydride, 4,4′-oxydiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, It is preferably a residue of an acid dianhydride selected from 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride and 2,2-bis (4-carboxylic acid phenyl) propanoic dianhydride It is.

（上記式（２）において、Ｘは（１Ｒ，２Ｒ）−（＋）−１，２−トランスシクロヘキサンジアミン残基、（１Ｓ，２Ｓ）−（−）−１，２−トランスシクロヘキサンジアミン残基、又は１，４−シスシクロヘキサンジアミン残基、Ｙは酸二無水物残基、Ｚはアリルナジック酸無水化物残基、ｎはイミド繰り返し構造の平均重合度で１〜１０である）
The amic acid oligomer according to the present invention includes (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1, It has a diamine composition consisting of any one kind of aliphatic diamine selected from 4-ciscyclohexanediamine, and is represented by the following general formula (2).

(In the above formula (2), X represents a (1R, 2R)-(+)-1,2-transcyclohexanediamine residue, a (1S, 2S)-(−)-1,2-transcyclohexanediamine residue, Or 1,4-ciscyclohexanediamine residue, Y is an acid dianhydride residue, Z is an allyl nadic acid anhydride residue , and n is an average degree of polymerization of an imide repeating structure of 1 to 10.

  In addition, the polyimide resin according to the present invention is obtained by heat-curing the imide oligomer or the amic acid oligomer.

  According to the present invention, an imide oligomer excellent in thermoformability can be obtained by using a cyclic diamine having a specific structure as a raw material diamine monomer, and a polyimide resin obtained by heat-curing this imide oligomer is Excellent colorless transparency and heat resistance.

The imide oligomer according to the present invention includes (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4-cis. It has a diamine composition consisting of any one kind of aliphatic diamine selected from cyclohexanediamine, and is represented by the following general formula (1).

  In the general formula (1), X is a (1R, 2R)-(+)-1,2-transcyclohexanediamine residue, a (1S, 2S)-(−)-1,2-transcyclohexanediamine residue, Alternatively, it is a 1,4-ciscyclohexanediamine residue.

The structure of (1R, 2R)-(+)-1,2-transcyclohexanediamine is represented by the following general formula (3), and the structure of (1S, 2S)-(−)-1,2-transcyclohexanediamine is represented by the following general formula. In the formula (4), the structure of 1,4-ciscyclohexanediamine is shown in the following general formula (5). That is, X in the general formula (1) is a residue excluding the amino group of the aliphatic diamine represented by the following general formulas (3) to (5).

  The imide composition of the imide oligomer of the present invention is (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4. -It consists of any one kind of aliphatic diamine selected from cis cyclohexane diamine. In the present invention, the use of any one of the above three aliphatic diamines as the raw material diamine monomer facilitates the formation of a helical structure and makes it difficult for intermolecular stacking to occur. It can be melted and thermoforming is facilitated. In addition, in polyimide resin after heat curing, electron transfer between molecules is controlled by a spiral structure, so light transmittance (10 mm film thickness) at a wavelength of 350 nm is about 95% or more, which is also very colorless and transparent. Is excellent. Furthermore, the 5% thermal decomposition temperature of the polyimide resin is about 400 ° C. or higher, which is excellent in heat resistance.

  In addition, for example, trans 1,2-cyclohexanediamine which is not separated from optical isomers is the above (1R, 2R)-(+)-1,2-transcyclohexanediamine and (1S, 2S)-(−)-1 , 2-transcyclohexanediamine, which is considered to contain about half of each compound, but even if such an optical isomer mixture is used as a raw material diamine monomer, the polyimide after heat curing The colorless transparency and heat resistance of the resin cannot be obtained sufficiently. For this reason, the diamine composition of the imide oligomer of the present invention comprises any one of the above-mentioned three types of aliphatic diamines. In the diamine composition, other types of diamines may be contained as long as the amount is impurities, and the content of such other types of diamines is less than 5% by mass, preferably less than 1% by mass.

In the above general formula (1), Y is an acid dianhydride residue. The acid dianhydride component used in the imide oligomer of the present invention is not particularly limited as long as it can form a polyimide structure by a condensation reaction with a diamine. For example, 1, 2, 3, 4 -Cyclopentanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran- 3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2 -Dicarboxylic dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 4,4'-biphthalic dianhydride, 3,3', 4 4 '-Diphenylsulfonic acid dianhydride , 4,4'-(hexafluoroisopyridene) diphthalic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid Dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride, 2,2-bis (phenyl 4-carboxylate) And propanoic acid dianhydride. That is, Y in the general formula (1) is a residue obtained by removing a carboxyl group from these acid dianhydrides.

In the general formula (1), Z is a crosslinkable reactive group. In the imide oligomer of the present invention, thermosetting is imparted by modifying the terminal with a compound having a crosslinkable reactive group. The crosslinkable-terminated compound used in the present invention, it is possible to have use the A Rirunajikku acid anhydrides.

In addition, the allyl nadic acid anhydride used as a crosslinkable terminal compound in the present invention is a compound in which an allyl group (2-propenyl group) is substituted with a nadic acid anhydride (an anhydride of norbornene substituted with 2 carboxyl groups) It is a compound represented by the following general formula (6).

  In the allyl nadic acid anhydride represented by the general formula (6), the acid anhydride group is condensed with an arbitrary amino group at the end of the imide oligomer chain to form an imide bond, and is added as a crosslinkable reactive group. The As the crosslinkable terminal compound, for example, 4-phenylethynylphthalic anhydride is widely used. However, these conventional crosslinkable terminal compounds require a high temperature for the crosslinking reaction (thermosetting). Since the cured polyimide resin is very strong, it lacks flexibility in molding and is difficult to handle. On the other hand, by using allyl nadic acid anhydride as the crosslinkable terminal compound, primary curing can be performed at a lower temperature than conventional. For this reason, for example, it is possible to flexibly adopt a molding method suitable for the target product, such as taking an approximate mold by primary curing at low temperature, then finely molding and then secondary curing at high temperature. In addition, for example, when compared with unsubstituted nadic acid, since it is a compound substituted with an allyl group having a high electron donor property, light absorption based on intermolecular electron transfer is shortened, and the colorless transparency of the polyimide resin is reduced. Improved.

  Moreover, in the said General Formula (1), (2), n is an average degree of polymerization of each imide repeating structure, and is 1-10. In addition, this average degree of polymerization can be suitably adjusted by changing the ratio of the non-axisymmetric aromatic diamine, acid dianhydride, and diamine used for the production of the imide oligomer. In the imide oligomer of the present invention, if the average degree of polymerization n of each imide repeating structure exceeds 10, the heat meltability may be inferior and molding may be difficult. From the viewpoint of moldability of the imide oligomer, the average degree of polymerization of each imide repeating structure is preferably 1 to 5, and more preferably 2 to 4. When the average degree of polymerization of each imide repeating structure is within the above range, an imide oligomer having particularly excellent moldability can be obtained.

In addition, the imide oligomer concerning this invention can be prepared by the following process, for example.
(A) selected from (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4-ciscyclohexanediamine Any one kind of aliphatic diamine component and an optional acid dianhydride component are reacted to prepare a polyamic acid.
Here, the polymerization degree can be appropriately adjusted by changing the addition ratio and reaction time of the diamine component and the acid dianhydride component. In this invention, it is necessary to adjust the addition ratio of each said component so that the average degree of polymerization of an imide structure repeating unit may be 1-10.

  Examples of the solvent used in the reaction include aprotic solvents such as N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide, NN-dimethylacetamide (DMAc), and γ-butyrolactam. It is done. When the polymerization reaction is carried out in an aprotic solvent, it is usually obtained as an amic acid oligomer having an amide moiety and a carboxylic acid moiety in the molecule. This amic acid oligomer is, for example, added to an imidizing agent at a low temperature or heated and refluxed at a high temperature to dehydrate and cyclize (imidize) the amide moiety and the carboxylic acid moiety to form an imide oligomer. be able to.

(B) Furthermore, a crosslinkable terminal compound is added to the terminal of the imide oligomer or amic acid oligomer obtained above.
Since this crosslinkable terminal forms a crosslinked structure with each other by heating, this can impart thermosetting properties to the imide oligomer.
Here, the crosslinkable terminal compound may be any one that can react with either the unreacted carboxylic acid group in the acid dianhydride or the unreacted amino group in the diamine. What is necessary is just to adjust suitably the addition amount of a crosslinkable terminal compound according to the equivalent of the reactive carboxylic acid group or amino acid group. In addition, as a crosslinkable terminal compound, allyl nadic acid anhydride can be used suitably.

  The reaction in the step (B) can be carried out continuously with the step (A). Usually, all steps (A) and (B) are carried out in the state of an amic acid oligomer and finally converted into an imide oligomer. . That is, in the state of the amic acid oligomer obtained in the step (A), the crosslinkable terminal compound is added in the step (B), followed by, for example, adding an imidizing agent at a low temperature, or heating and refluxing at a high temperature. As a result, the amide moiety and the carboxylic acid moiety are dehydrated and cyclized (imidized) to obtain an imide oligomer having a crosslinkable reactive group at the molecular end.

  In addition, in the said (A) and (B) process, it is the category of this invention also about the amic acid oligomer which has not imidated. Such an amic acid oligomer can be easily converted to an imide oligomer by performing a dehydration / cyclization reaction by heating in the presence of a dehydrating agent. For example, the imide oligomer of the present invention can be obtained by heating and refluxing the amic acid oligomer solution of the present invention at a high temperature of about 80 to 140 ° C. in the presence of pyridine and acetic anhydride. Alternatively, for example, the imide oligomer of the present invention can be obtained by applying an amic acid oligomer solution onto a support having good peelability such as a glass plate and heating to about 100 to 140 ° C. .

  In the reaction steps (A) and (B), both are preferably performed in the presence of an inert gas such as argon or nitrogen, or in a vacuum.

  The imide oligomer obtained as described above can be used as it is after the reaction. For example, after the reaction is completed, the solution after completion of the reaction is stirred into a large amount of water and isolated by filtration. By drying at about 100 ° C., it can be used as a powdered imide oligomer. Also. The imide oligomer powder thus obtained can be used as a solution dissolved in an appropriate solvent, if necessary.

  In addition, the imide oligomer obtained as described above can be made into a polyimide resin having excellent heat resistance by being cured by heating with the oligomer alone or impregnated in a fibrous reinforcing material such as carbon fiber. it can. In addition, since the imide oligomer according to the present invention exhibits a helical structure and is excellent in moldability, for example, it can be easily molded by a mold or the like, or can be applied to a fibrous reinforcing material or the like. Impregnation can also be performed relatively easily.

  Further, when the imide oligomer is heat-cured, the heating temperature and the heating time can be appropriately adjusted according to the desired physical properties of the polyimide resin. In addition, although the imide oligomer concerning this invention changes also with the kind etc. of a crosslinkable terminal compound, it usually produces thermosetting at about 300-370 degreeC. In a normal case, for example, the imide oligomer is preliminarily heated at a temperature of about 60 to 320 ° C. for a predetermined time, and then the imide oligomer is heated at a temperature of 250 to 400 ° C. for a predetermined time to perform a crosslinking reaction. A cured resin is obtained. In particular, when allyl nadic acid is used as the crosslinking terminal, for example, heat melting can be performed at 60 to 140 ° C., and primary curing can be performed at about 160 to 180 ° C. and secondary curing can be performed at about 250 to 400 ° C. Usually, the heat resistance of the cured polyimide resin is improved by increasing the heating temperature in each heating step or increasing the heating time.

  In addition, what is necessary is just to perform in accordance with a well-known method manufacture of the polyimide resin molding using the imide oligomer of this invention. For example, the polyimide resin molded body can be obtained by filling the mold with the imide oligomer powder of the present invention and heat compression molding at about 250 to 370 ° C. and about 0.5 to 5 MPa for about 1 to 5 hours. . Further, for example, a fibrous reinforcing material such as carbon fiber is impregnated with the imide oligomer solution of the present invention, and dried by heating at 150 to 260 ° C. (150 to 200 ° C. when the cross-linking end is allyl nadic acid) for about 1 to 5 hours. After that, it is further heated under pressure at 250 to 370 ° C. for about 1 to 5 hours to obtain a fiber-containing composite of polyimide resin. Moreover, for example, the polyimide resin film can be obtained by applying the imide oligomer solution of the present invention onto a support having good peelability such as a glass plate and heating at 250 to 350 ° C. for about 1 to 5 hours. it can.

（１Ｒ，２Ｒ）−（＋）−１，２−トランスシクロヘキサンジアミン４５．６８ｇをアルゴン気流下Ｎ，Ｎ−ジメチルアセトアミド３００ｍｌに溶解させ、１，２，３，４−シクロペンタンテトラカルボン酸二無水化物６３．０４ｇを加え、約３０分間室温下撹拌した。その後、アリルナジック酸無水化物４０．０８ｇを加え、室温下約1時間撹拌後、無水酢酸／ピリジン＝２／１溶液９０ｇを加え約１２時間溶媒を加温した。イオン交換水４００ｍｌに反応液を投入し、濾過後水洗を数回繰り返し、濾過後、真空下一晩乾燥させ、黄白色の粉末状イミドオリゴマーを得た。なお、得られたイミドオリゴマーは８０℃程度で軟化を開始した。 Example 1

45.68 g of (1R, 2R)-(+)-1,2-transcyclohexanediamine was dissolved in 300 ml of N, N-dimethylacetamide under an argon stream, and 1,2,3,4-cyclopentanetetracarboxylic dianhydride The compound 63.04g was added, and it stirred under room temperature for about 30 minutes. Thereafter, 40.08 g of allyl nadic acid anhydride was added, and after stirring for about 1 hour at room temperature, 90 g of acetic anhydride / pyridine = 2/1 solution was added and the solvent was heated for about 12 hours. The reaction solution was poured into 400 ml of ion-exchanged water, and after filtration, washing with water was repeated several times. After filtration, it was dried overnight under vacuum to obtain a yellowish white powdery imide oligomer. The obtained imide oligomer started to soften at about 80 ° C.

  The imide oligomer powder obtained above was taken in a sample bottle and heated at 170 ° C. for 8 hours, 280 ° C. for 5 hours, 320 ° C. for 2 hours, and 350 ° C. for 2 hours and a half to obtain a colorless and transparent cured product. As a result of analysis by TG-DTA (EXSTAR TG / DTA6000: manufactured by SII) under a nitrogen stream, total light transmission at a 5% thermal decomposition temperature of 430.5 ° C. (temperature increase rate 10 ° C./min) and a film thickness of 10 mm It was confirmed that the rate was 96% or more (wavelength 350 nm, UV-3600: manufactured by Shimadzu Corporation).

（１Ｓ，２Ｓ）−（−）−１，２−トランスシクロヘキサンジアミン４５．６８ｇをアルゴン気流下Ｎ，Ｎ−ジメチルアセトアミド３００ｍｌに溶解させ、１，２，３，４−シクロペンタンテトラカルボン酸二無水化物６３．０４ｇを加え、約３０分間室温下撹拌した。その後、アリルナジック酸無水化物４０．８１ｇを加え、室温下約1時間撹拌後、無水酢酸／ピリジン＝２／１溶液９０ｇを加え約１２時間溶媒を加温した。イオン交換水４００ｍｌに反応液を投入し、濾過後水洗を数回繰り返し、濾過後、真空下一晩乾燥させ、黄白色の粉末状イミドオリゴマーを得た。なお、得られたイミドオリゴマーは８０℃程度で軟化を開始した。 Example 2

45.68 g of (1S, 2S)-(−)-1,2-transcyclohexanediamine was dissolved in 300 ml of N, N-dimethylacetamide under an argon stream, and 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride. The compound 63.04g was added, and it stirred under room temperature for about 30 minutes. Thereafter, 40.81 g of allyl nadic acid anhydride was added, and after stirring for about 1 hour at room temperature, 90 g of acetic anhydride / pyridine = 2/1 solution was added and the solvent was heated for about 12 hours. The reaction solution was poured into 400 ml of ion-exchanged water, and after filtration, washing with water was repeated several times. After filtration, it was dried overnight under vacuum to obtain a yellowish white powdery imide oligomer. The obtained imide oligomer started to soften at about 80 ° C.

  The imide oligomer powder obtained above was taken in a sample bottle and heated at 170 ° C. for 8 hours, 280 ° C. for 5 hours, 320 ° C. for 2 hours, and 350 ° C. for 2 hours and a half to obtain a colorless and transparent cured product. As a result of analysis by TG-DTA (EXSTAR TG / DTA6000: manufactured by SII) under a nitrogen stream, the total light transmission at a 5% thermal decomposition temperature of 430.0 ° C. (temperature increase rate 10 ° C./min) and a film thickness of 10 mm It was confirmed that the rate was 96% or more (wavelength 350 nm, UV-3600: manufactured by Shimadzu Corporation).

１，４−シスシクロヘキサンジアミン４５．６８ｇをアルゴン気流下Ｎ，Ｎ−ジメチルアセトアミド３００ｍｌに溶解させ、１，２，３，４−シクロペンタンテトラカルボン酸二無水化物６３．０４ｇを加え、約３０分間室温下撹拌した。その後、アリルナジック酸無水化物３８．０１ｇを加え、室温下約1時間撹拌後、無水酢酸／ピリジン＝２／１溶液９０ｇを加え約１２時間溶媒を加温した。イオン交換水４００ｍｌに反応液を投入し、濾過後水洗を数回繰り返し、濾過後、真空下一晩乾燥させ、黄白色の粉末状イミドオリゴマーを得た。なお、得られたイミドオリゴマーは８０℃程度で軟化を開始した。 Example 3

45.68 g of 1,4-ciscyclohexanediamine was dissolved in 300 ml of N, N-dimethylacetamide under an argon stream, and 63.04 g of 1,2,3,4-cyclopentanetetracarboxylic dianhydride was added for about 30 minutes. Stir at room temperature. Thereafter, 38.01 g of allyl nadic acid anhydride was added, and after stirring for about 1 hour at room temperature, 90 g of an acetic anhydride / pyridine = 2/1 solution was added and the solvent was heated for about 12 hours. The reaction solution was poured into 400 ml of ion-exchanged water, and after filtration, washing with water was repeated several times. After filtration, it was dried overnight under vacuum to obtain a yellowish white powdery imide oligomer. The obtained imide oligomer started to soften at about 80 ° C.

  The imide oligomer powder obtained above was taken in a sample bottle and heated at 170 ° C. for 8 hours, 280 ° C. for 5 hours, 320 ° C. for 2 hours, and 350 ° C. for 2 hours and a half to obtain a colorless and transparent cured product. As a result of analysis by TG-DTA (EXSTAR TG / DTA6000: manufactured by SII) under a nitrogen stream, total light transmission at a 5% thermal decomposition temperature of 450.5 ° C. (temperature increase rate 10 ° C./min) and a film thickness of 10 mm It was confirmed that the rate was 96% or more (wavelength 350 nm, UV-3600: manufactured by Shimadzu Corporation).

  From the results of Examples 1 to 3, (1R, 2R)-(+)-1,2-transcyclohexanediamine and (1S, 2S)-(−)-1,2-transcyclohexanediamine were used as the raw material diamine monomer. The imide oligomers of Examples 1 to 3 obtained by using 1,4-ciscyclohexanediamine all started softening at about 80 ° C., so that it was found that thermoforming was relatively easy. . Furthermore, in polyimide resins obtained by heat curing these imide oligomers, the total light transmittance at 350 nm at a film thickness of 10 mm is 96% or more, and it is very excellent in colorless transparency. Was confirmed. The 5% thermal decomposition temperature of the polyimide resin was 430 to 450 ° C., and it was found that the heat resistance was also excellent.

Comparative Example 1
45.68 g of trans-1,2-diaminocyclohexane unseparated from the optical isomer was dissolved in 300 ml of N, N-dimethylacetamide under an argon stream, and 1,2,3,4-cyclopentanetetracarboxylic dianhydride 63. 04 g was added and stirred at room temperature for about 30 minutes. Thereafter, 32.83 g of nadic acid anhydride was added, and after stirring for about 1 hour at room temperature, 90 g of acetic anhydride / pyridine = 2/1 solution was added and the solvent was heated for about 12 hours. The reaction solution was poured into 400 ml of ion-exchanged water, filtered, and dried overnight under vacuum to obtain a yellowish white powdery imide oligomer. The obtained imide oligomer started to soften at about 140 ° C.

  The imide oligomer powder obtained above was taken in a sample bottle and heated at 170 ° C. for 8 hours, 280 ° C. for 5 hours, 320 ° C. for 2 hours, and 350 ° C. for 2 hours and a half to obtain a colorless and transparent cured product. As a result of analysis by TG-DTA (EXSTAR TG / DTA6000: manufactured by SII) under a nitrogen stream, the total light transmittance at a film thickness of 10 mm is 5% thermal decomposition temperature is 410 ° C (temperature increase rate 10 ° C / min). It was confirmed that it was 85% or more (wavelength 350 nm, UV-3600: manufactured by Shimadzu Corporation).

Comparative Example 2
45.68 g of trans-1,4-diaminocyclohexane was dissolved in 300 ml of N, N-dimethylacetamide under an argon stream, and 63.04 g of 1,2,3,4-cyclopentanetetracarboxylic dianhydride was added for about 30 minutes. After stirring at room temperature, 32.83 g of nadic acid anhydride was added. After stirring at room temperature for about 1 hour, 90 g of acetic anhydride / pyridine = 2/1 solution was added and the solvent was heated for about 12 hours. The reaction solution was poured into 400 ml of ion-exchanged water, and after filtration, washing with water was repeated several times. After filtration, it was dried overnight under vacuum to obtain a yellowish white powdery imide oligomer. The obtained imide oligomer started to soften at about 120 ° C.

  The imide oligomer powder obtained above was placed in a sample bottle and heated in a nitrogen stream at 250 ° C. for 2 hours, 280 ° C. for 5 hours, 320 ° C. for 2 hours, and 350 ° C. for 2 hours and a half to obtain a colorless and transparent cured product. As a result of analysis by TG-DTA (EXSTAR TG / DTA6000: manufactured by SII) under a nitrogen stream, total light transmission at a 5% thermal decomposition temperature of 380.5 ° C. (temperature increase rate 10 ° C./min) and a film thickness of 10 mm It was confirmed that the rate was 85% or more (wavelength 350 nm, UV-3600: manufactured by Shimadzu Corporation).

  From the results of Comparative Example 1, the softening start temperature of the imide oligomer using trans-1,2-diaminocyclohexane not separated from the optical isomer as the diamine monomer was 140 ° C., and the polyimide resin obtained by heating and curing the polyimide resin was obtained. The colorless transparency had a light transmittance at 350 nm of 85% or more, and was significantly inferior to Examples 1 and 2 in which each isomer after optical separation was used alone. It was also found that the 5% pyrolysis temperature was slightly lower than those of Examples 1 and 2. From this result, trans-1,2-diaminocyclohexane used as the diamine monomer of the present invention is a compound optically separated as a (1R, 2R)-(+) form or a (1S, 2S)-(-) form. It can be said that it is necessary to use it. Moreover, from the result of the above Comparative Example 2, in the imide oligomer using trans-1,4-diaminocyclohexane, thermoformability (softening start temperature) and colorless transparency compared to Example 3 using a cis isomer. The heat resistance was inferior.

Claims (5)

Any selected from (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4-ciscyclohexanediamine An imide oligomer having a diamine composition composed of one kind of aliphatic diamine and represented by the following general formula (1).

(In the above formula (1), X is a (1R, 2R)-(+)-1,2-transcyclohexanediamine residue, a (1S, 2S)-(−)-1,2-transcyclohexanediamine residue, Or 1,4-ciscyclohexanediamine residue, Y is an acid dianhydride residue, Z is an allyl nadic acid anhydride residue , and n is an average degree of polymerization of an imide repeating structure of 1 to 10. 2. The imide oligomer according to claim 1 , wherein each imide repeating structure has an average degree of polymerization n of 1 to 5, and a number average molecular weight of the whole imide oligomer is 8000 or less. The imide oligomer according to claim 1, wherein the acid anhydride residue represented by Y in the general formula (1) is 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2. 2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydro Naphthalene-1,2-dicarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 4,4′-biphthalic dianhydride, 3,3 ′, 4,4′-diphenylsulfonic dianhydride , 4,4 ′ -(Hexafluoroisopyri Den) diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride A residue of an acid dianhydride selected from 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride, 2,2-bis (4-carboxylic acid phenyl) propanoic dianhydride An imide oligomer characterized by Any selected from (1R, 2R)-(+)-1,2-transcyclohexanediamine, (1S, 2S)-(−)-1,2-transcyclohexanediamine, and 1,4-ciscyclohexanediamine An amic acid oligomer having a diamine composition composed of one kind of aliphatic diamine and represented by the following general formula (2).

(In the above formula (2), X represents a (1R, 2R)-(+)-1,2-transcyclohexanediamine residue, a (1S, 2S)-(−)-1,2-transcyclohexanediamine residue, Or 1,4-ciscyclohexanediamine residue, Y is an acid dianhydride residue, Z is an allyl nadic acid anhydride residue , and n is an average degree of polymerization of an imide repeating structure of 1 to 10. Polyimide resin, characterized by comprising cured by heating the amic acid oligomer according to the imide oligomer or claim 4 according to any one of claims 1 to 3.