JP5475558B2 - Polyester film for electrical insulation - Google Patents

Description

  The present invention relates to a polyester film for electrical insulation comprising a composition in which a carboxyl group terminal of an aromatic polyester is sealed with a carbodiimide compound.

  Films mainly composed of aromatic polyester have excellent properties such as mechanical properties, thermal properties, electrical properties, surface properties, chemical resistance, heat resistance, processability, etc., for magnetic recording media, for electrical insulation, for capacitors, It is used for many applications such as packaging and various industrial materials. Among these applications, for example, electrical properties are required for electrical insulation films, but for motor insulation films, especially motor insulation films used for electric vehicles, etc., characteristics such as heat resistance and hydrolysis resistance are also required. ing. In recent years, it has been demanded that heat deterioration is difficult over a long period of time due to an increase in the amount of heat generated by electrical equipment and an increase in the operating temperature range.

  In response to such demands, it has already been proposed to suppress hydrolysis by applying a carbodiimide compound to a film made of an aromatic polyester (Patent Documents 1 and 2). However, the carbodiimide compound used in this proposal is a linear carbodiimide compound.

  When a linear carbodiimide compound is used as an end-capping agent for a polymer compound, a compound having an isocyanate group is liberated as a result of the reaction of the linear carbodiimide compound binding to the end of the polymer compound, generating a unique odor of the isocyanate compound. However, deteriorating the working environment is a problem.

Japanese Patent Laying-Open No. 2005-2265 JP 2005-29688 A

  An object of the present invention is a composition in which the end of an aromatic polyester is sealed with a carbodiimide compound, does not liberate an isocyanate compound, is excellent in hydrolysis resistance, and is difficult to be thermally deteriorated over a long period of time, that is, long-term An object of the present invention is to provide a polyester film for electrical insulation having excellent heat deterioration resistance.

As a result of intensive studies, the present inventors have completed the present invention. That is, the object of the present invention is to
1. It is composed of a composition in which an aromatic polyester is mixed with a compound containing at least a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded by a bonding group, and the plane orientation coefficient is 0. A polyester film for electrical insulation which is 1 or more.
Is achieved.

（式中、Ｑは、脂肪族基、脂環族基、芳香族基またはこれらの組み合わせである２〜４価の結合基であり、ヘテロ原子を含有していてもよい。）
４．Ｑは、下記式（１−１）、（１−２）または（１−３）で表される２〜４価の結合基である上記３記載の電気絶縁用ポリエステルフィルム。

（式中、Ａｒ^１およびＡｒ^２は各々独立に、２〜４価の炭素数５〜１５の芳香族基である。Ｒ^１およびＲ^２は各々独立に、２〜４価の炭素数１〜２０の脂肪族基、２〜４価の炭素数３〜２０の脂環族基またはこれらの組み合わせ、またはこれら脂肪族基、脂環族基と２〜４価の炭素数５〜１５の芳香族基の組み合わせである。Ｘ^１およびＸ^２は各々独立に、２〜４価の炭素数１〜２０の脂肪族基、２〜４価の炭素数３〜２０の脂環族基、２〜４価の炭素数５〜１５の芳香族基、またはこれらの組み合わせである。ｓは０〜１０の整数である。ｋは０〜１０の整数である。なお、ｓまたはｋが２以上であるとき、繰り返し単位としてのＸ^１、あるいはＸ^２が、他のＸ^１、あるいはＸ^２と異なっていてもよい。Ｘ^３は、２〜４価の炭素数１〜２０の脂肪族基、２〜４価の炭素数３〜２０の脂環族基、２〜４価の炭素数５〜１５の芳香族基、またはこれらの組み合わせである。但し、Ａｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２およびＸ^３はヘテロ原子を含有していてもよい、また、Ｑが２価の結合基であるときは、Ａｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２およびＸ^３は全て２価の基である。Ｑが３価の結合基であるときは、Ａｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２およびＸ^３の内の一つが３価の基である。Ｑが４価の結合基であるときは、Ａｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２およびＸ^３の内の一つが４価の基であるか、二つが３価の基である。）
５．環状構造を含む化合物が、下記式（２）で表される上記１記載の電気絶縁用ポリエステルフィルム。

（式中、Ｑ_ａは、脂肪族基、脂環族基、芳香族基またはこれらの組み合わせである２価の結合基であり、ヘテロ原子を含有していてもよい。）
６．Ｑ_ａは、下記式（２−１）、（２−２）または（２−３）で表される２価の結合基である上記５記載の電気絶縁用ポリエステルフィルム。

（式中、Ａｒ_ａ ^１、Ａｒ_ａ ^２、Ｒ_ａ ^１、Ｒ_ａ ^２、Ｘ_ａ ^１、Ｘ_ａ ^２、Ｘ_ａ ^３、ｓおよびｋは、各々式（１−１）〜（１−３）中のＡｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２、Ｘ^３、ｓおよびｋと同じである。）
７．環状構造を含む化合物が、下記式（３）で表される上記１記載の電気絶縁用ポリエステルフィルム。

（式中、Ｑ_ｂは、脂肪族基、脂環族基、芳香族基またはこれらの組み合わせである３価の結合基であり、ヘテロ原子を含有していてもよい。Ｙは、環状構造を担持する担体である。）
８．Ｑ_ｂは、下記式（３−１）、（３−２）または（３−３）で表される３価の結合基である上記７記載の電気絶縁用ポリエステルフィルム。

（式中、Ａｒ_ｂ ^１、Ａｒ_ｂ ^２、Ｒ_ｂ ^１、Ｒ_ｂ ^２、Ｘ_ｂ ^１、Ｘ_ｂ ^２、Ｘ_ｂ ^３、ｓおよびｋは、各々式（１−１）〜（１−３）のＡｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２、Ｘ^３、ｓおよびｋと同じである。但しこれらの内の一つは３価の基である。）
９．Ｙは、単結合、二重結合、原子、原子団またはポリマーである上記７記載の電気絶縁用ポリエステルフィルム。
１０．環状構造を含む化合物が、下記式（４）で表される上記１記載の電気絶縁用ポリエステルフィルム。

（式中、Ｑ_ｃは、脂肪族基、芳香族基、脂環族基またはこれらの組み合わせである４価の結合基であり、ヘテロ原子を保有していてもよい。Ｚ^１およびＺ^２は、環状構造を担持する担体である。）
１１．Ｑ_ｃは、下記式（４−１）、（４−２）または（４−３）で表される４価の結合基である上記１０記載の電気絶縁用ポリエステルフィルム。

（式中、Ａｒ_ｃ ^１、Ａｒ_ｃ ^２、Ｒ_ｃ ^１、Ｒ_ｃ ^２、Ｘ_ｃ ^１、Ｘ_ｃ ^２、Ｘ_ｃ ^３、ｓおよびｋは、各々式（１−１）〜（１−３）の、Ａｒ^１、Ａｒ^２、Ｒ^１、Ｒ^２、Ｘ^１、Ｘ^２、Ｘ^３、ｓおよびｋと同じである。但し、これらの内の一つが４価の基であるか、二つが３価の基である。）
１２．Ｚ^１およびＺ^２は各々独立に、単結合、二重結合、原子、原子団またはポリマーである上記１０記載の電気絶縁用ポリエステルフィルム。
１３．芳香族ポリエステルがポリエチレンテレフタレートである上記１〜１２のいずれか１に記載の電気絶縁用ポリエステルフィルム。
１４．芳香族ポリエステルがポリエチレンナフタレートである上記１〜１２のいずれか１に記載の電気絶縁用ポリエステルフィルム。
１５．組成物が下記の３成分からなる、上記１記載の電気絶縁用ポリエステルフィルム。
（ａ）カルボジイミド基を１個有しその第一窒素と第二窒素とが結合基により結合されている環状構造を少なくとも含む化合物、
（ｂ）芳香族ポリエステル、
（ｃ）カルボジイミド基を１個有しその第一窒素と第二窒素とが結合基により結合されている環状構造を少なくとも含む化合物によってカルボキシル基が封止された芳香族ポリエステル。
１６．組成物が下記の２成分からなる、上記１記載の電気絶縁用ポリエステルフィルム。
（ａ）カルボジイミド基を１個有しその第一窒素と第二窒素とが結合基により結合されている環状構造を少なくとも含む化合物、
（ｃ）カルボジイミド基を１個有しその第一窒素と第二窒素とが結合基により結合されている環状構造を少なくとも含む化合物によってカルボキシル基が封止された芳香族ポリエステル。
１７．組成物が下記の１成分からなる、上記１記載の電気絶縁用ポリエステルフィルム。
（ｃ）カルボジイミド基を１個有しその第一窒素と第二窒素とが結合基により結合されている環状構造を少なくとも含む化合物によってカルボキシル基が封止された芳香族ポリエステル。
１８．モーター絶縁用であることを特徴とする上記１〜１７のいずれか１に記載の電気絶縁用ポリエステルフィルム。 Further, the present invention includes the following.
2. 2. The polyester film for electrical insulation according to 1 above, wherein the number of atoms forming the cyclic structure is 8 to 50.
3. The polyester film for electrical insulation according to 1 above, wherein the cyclic structure is represented by the following formula (1).

(In the formula, Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.)
4). 4. The polyester film for electrical insulation according to 3 above, wherein Q is a divalent to tetravalent linking group represented by the following formula (1-1), (1-2) or (1-3).

(In the formula, Ar ¹ and Ar ² are each independently an aromatic group having 2 to 4 carbon atoms and 5 to 15 carbon atoms. R ¹ and R ² are each independently 1 to 2 carbon atoms having 1 to 4 carbon atoms. 20 aliphatic groups, 2 to 4 valent alicyclic groups having 3 to 20 carbon atoms, or combinations thereof, or these aliphatic groups, alicyclic groups and 2 to 4 valent aromatic carbon atoms having 5 to 15 carbon atoms X ¹ and X ² are each independently a divalent to tetravalent aliphatic group having 1 to 20 carbon atoms, a divalent to tetravalent carbon atom having 3 to 20 alicyclic groups, 2 to 4 A valent aromatic group having 5 to 15 carbon atoms, or a combination thereof, s is an integer of 0 to 10. k is an integer of 0 to 10. When s or k is 2 or more, X ¹ or X ² as a repeating unit may be different from other X ¹ or X ^2. X ³ is a divalent to tetravalent carbon number. An aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 2 to 4 carbon atoms having 3 to 20 carbon atoms, an aromatic group having 2 to 4 carbon atoms having 5 to 15 carbon atoms, or a combination thereof, provided that Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ may contain a hetero atom, and when Q is a divalent linking group, Ar ¹ , Ar ² , R 3 ¹ , R ² , X ¹ , X ² and X ³ are all divalent groups, and when Q is a trivalent linking group, Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ^{One of 2} and X ³ is a trivalent group, and when Q is a tetravalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ One of them is a tetravalent group or two are trivalent groups.)
5. 2. The polyester film for electrical insulation according to 1 above, wherein the compound containing a cyclic structure is represented by the following formula (2).

(Wherein Q _a is a divalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.)
6). Q _a is represented by the following formula (2-1), (2-2) or a divalent polyester film for electrical insulation of the 5, wherein the linking group represented by (2-3).

(In the formula, Ar _a ¹ , Ar _a ² , R _a ¹ , R _a ² , X _a ¹ , X _a ² , X _a ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. The same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k in the inside.)
7). 2. The polyester film for electrical insulation according to 1 above, wherein the compound containing a cyclic structure is represented by the following formula (3).

(Wherein Q _b is a trivalent linking group which is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom. Y represents a cyclic structure. It is a carrier to be supported.)
8). Q _b is represented by the following formula (3-1), (3-2) or trivalent polyester film for electrical insulation of the 7, wherein the linking group represented by (3-3).

(In the formula, Ar _b ¹ , Ar _b ² , R _b ¹ , R _b ² , X _b ¹ , X _b ² , X _b ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s, and k, with one of these being a trivalent group.)
9. 8. The polyester film for electrical insulation as described in 7 above, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer.
10. 2. The polyester film for electrical insulation according to 1 above, wherein the compound containing a cyclic structure is represented by the following formula (4).

(Wherein Q _c is a tetravalent linking group that is an aliphatic group, an aromatic group, an alicyclic group, or a combination thereof, and may have a hetero atom. Z ¹ and Z ² are A carrier carrying a ring structure.)
11. 11. The electrical insulating polyester film as described in 10 above, wherein Q _c is a tetravalent linking group represented by the following formula (4-1), (4-2) or (4-3).

(In the formula, Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² , X _c ³ , s and k are respectively represented by formulas (1-1) to (1-3) Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k, provided that one of them is a tetravalent group or two are 3 Valent group.)
12 11. The polyester film for electrical insulation as described in 10 above, wherein Z ¹ and Z ² are each independently a single bond, a double bond, an atom, an atomic group or a polymer.
13. The polyester film for electrical insulation according to any one of 1 to 12 above, wherein the aromatic polyester is polyethylene terephthalate.
14 The polyester film for electrical insulation according to any one of 1 to 12 above, wherein the aromatic polyester is polyethylene naphthalate.
15. 2. The polyester film for electrical insulation according to 1 above, wherein the composition comprises the following three components.
(A) a compound including at least a cyclic structure in which one carbodiimide group is bonded to the first nitrogen and the second nitrogen by a bonding group;
(B) aromatic polyester,
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.
16. 2. The polyester film for electrical insulation according to 1 above, wherein the composition comprises the following two components.
(A) a compound including at least a cyclic structure in which one carbodiimide group is bonded to the first nitrogen and the second nitrogen by a bonding group;
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.
17. 2. The polyester film for electrical insulation according to 1 above, wherein the composition comprises the following one component.
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.
18. 18. The polyester film for electrical insulation according to any one of 1 to 17 above, which is for motor insulation.

  ADVANTAGE OF THE INVENTION According to this invention, the polyester film for electrical insulation which consists of a composition by which the terminal of aromatic polyester was sealed with the carbodiimide compound without releasing an isocyanate compound can be provided. As a result, the generation of malodor due to the isocyanate compound can be suppressed and the working environment can be improved. At the same time, it is possible to provide a polyester film for electrical insulation that is excellent in hydrolysis resistance and long-term heat deterioration resistance. As a result, when used for electrical insulation, particularly for motor insulation, the film is less likely to deteriorate even under a high temperature use environment and can be used for a long time.

Hereinafter, the present invention will be described in detail.
<Cyclic carbodiimide compound>
In the present invention, the carbodiimide compound has a cyclic structure (hereinafter, the carbodiimide compound may be abbreviated as a cyclic carbodiimide compound). The cyclic carbodiimide compound may have a plurality of cyclic structures.

  The cyclic structure has one carbodiimide group (—N═C═N—), and the first nitrogen and the second nitrogen are bonded by a bonding group. One cyclic structure has only one carbodiimide group. For example, when there are a plurality of cyclic structures in the molecule, such as a spiro ring, one cyclic structure bonded to a spiro atom is included in each cyclic structure. Needless to say, the compound may have a plurality of carbodiimide groups as long as it has a carbodiimide group. The number of atoms in the cyclic structure is preferably 8 to 50, more preferably 10 to 30, further preferably 10 to 20, and particularly preferably 10 to 15.

  Here, the number of atoms in the cyclic structure means the number of atoms that directly constitute the cyclic structure. For example, it is 8 for an 8-membered ring and 50 for a 50-membered ring. This is because if the number of atoms in the cyclic structure is smaller than 8, the stability of the cyclic carbodiimide compound is lowered, and it may be difficult to store and use. From the viewpoint of reactivity, there is no particular restriction on the upper limit of the number of ring members, but cyclic carbodiimide compounds having more than 50 atoms are difficult to synthesize, and the cost may increase significantly. From this viewpoint, the number of atoms in the cyclic structure is preferably 10-30, more preferably 10-20, and particularly preferably 10-15.

The cyclic structure is preferably a structure represented by the following formula (1).

  In the formula, Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, each of which may contain a hetero atom and a substituent. A heteroatom in this case refers to O, N, S, P. Two of the valences of this linking group are used to form a cyclic structure. When Q is a trivalent or tetravalent linking group, it is bonded to a polymer or other cyclic structure via a single bond, a double bond, an atom, or an atomic group.

The linking group may include a heteroatom and a substituent, each having a divalent to tetravalent carbon number of 1 to 20 aliphatic group, a divalent to tetravalent carbon number of 3 to 20 alicyclic group, A linking group which is a tetravalent aromatic group having 5 to 15 carbon atoms or a combination thereof and has a necessary number of carbon atoms to form the cyclic structure defined above is selected. Examples of combinations include structures such as an alkylene-arylene group in which an alkylene group and an arylene group are bonded.
The linking group (Q) is preferably a divalent to tetravalent linking group represented by the following formula (1-1), (1-2) or (1-3).

In the formula, Ar ¹ and Ar ² are each independently a 2- to 4-valent aromatic group having 5 to 15 carbon atoms which may contain a hetero atom and a substituent.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group (divalent) include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

R ¹ and R ² each independently contain a heteroatom and a substituent, each having 2 to 4 valent aliphatic groups having 1 to 20 carbon atoms and 2 to 4 valent fatty acids having 3 to 20 carbon atoms A cyclic group, and a combination thereof, or a combination of the aliphatic group, the alicyclic group, and a divalent to tetravalent aromatic group having 5 to 15 carbon atoms.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As the alkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group , Cyclododecanetriyl group, cyclohexadecanetriyl group and the like. As the alkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

In the above formulas (1-1) and (1-2), X ¹ and X ² are each independently a divalent to tetravalent C 1-20 aliphatic optionally containing a hetero atom and a substituent. Group, a C2-C20 alicyclic group having 2 to 4 carbon atoms, a C2-C15 aromatic group having 2 to 4 carbon atoms, or a combination thereof.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As the alkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group , Cyclododecanetriyl group, cyclohexadecanetriyl group and the like. As the alkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

In the above formulas (1-1) and (1-2), s and k are integers of 0 to 10, preferably 0 to 3, more preferably 0 to 1. This is because if s and k exceed 10, the cyclic carbodiimide compound is difficult to synthesize, and the cost may increase significantly. From this viewpoint, the integer is preferably selected in the range of 0 to 3. When s or k is 2 or more, X ¹ or X ² as a repeating unit may be different from other X ¹ or X ² .

In the above formula (1-3), X ³ may contain a heteroatom and a substituent, respectively, a divalent to tetravalent aliphatic group having 1 to 20 carbon atoms, and a divalent to tetravalent carbon number of 3 to 20 Are alicyclic groups, divalent to tetravalent aromatic groups having 5 to 15 carbon atoms, or combinations thereof.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may contain a substituent, such as an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, or an ester group. , Ether group, aldehyde group and the like.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As the alkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group , Cyclododecanetriyl group, cyclohexadecanetriyl group and the like. As the alkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may contain a substituent, such as an alkyl group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, and an ester. Group, ether group, aldehyde group and the like.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ may contain a hetero atom, and when Q is a divalent linking group, Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ are all divalent groups. When Q is a trivalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ is a trivalent group. When Q is a tetravalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ is a tetravalent group or two are trivalent It is a group.

  Examples of the cyclic carbodiimide compound used in the present invention include compounds represented by (a) to (c) below.

[Cyclic carbodiimide compound (a)]
Examples of the cyclic carbodiimide compound used in the present invention include a compound represented by the following formula (2) (hereinafter sometimes referred to as “cyclic carbodiimide compound (a)”).

Wherein, Q _a is an aliphatic group, an alicyclic group, an aromatic group or a divalent linking group which is a combination of these, it may contain a heteroatom. The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (2), the aliphatic group, alicyclic group, and aromatic group are all divalent. Q _a is preferably a divalent linking group represented by the following formula (2-1), (2-2) or (2-3).

In the formula, Ar _a ¹ , Ar _a ² , R _a ¹ , R _a ² , X _a ¹ , X _a ² , X _a ³ , s and k are represented by formulas (1-1) to (1-3), respectively. Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k. However, these are all divalent.
Examples of the cyclic carbodiimide compound (a) include the following compounds.

[Cyclic carbodiimide compound (b)]
Furthermore, examples of the cyclic carbodiimide compound used in the present invention include a compound represented by the following formula (3) (hereinafter sometimes referred to as “cyclic carbodiimide compound (b)”).

Wherein, Q _b is an aliphatic group, an alicyclic group, an aromatic group or a trivalent linking group combinations thereof, and may contain a hetero atom. Y is a carrier supporting a cyclic structure. The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (3), the inner one of the group constituting the Q _b is trivalent.
Q _b is preferably a trivalent linking group represented by the following formula (3-1), (3-2) or (3-3).

In the formula, Ar _b ¹ , Ar _b ² , R _b ¹ , R _b ² , X _b ¹ , X _b ² , X _b ³ , s and k are respectively represented by the formulas (1-1) to (1-3). The same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k. However, one of these is a trivalent group.
Y is preferably a single bond, a double bond, an atom, an atomic group or a polymer. Y is a bonding portion, and a plurality of cyclic structures are bonded via Y to form a structure represented by the formula (3).
Examples of the cyclic carbodiimide compound (b) include the following compounds.

[Cyclic carbodiimide compound (c)]
Examples of the cyclic carbodiimide compound used in the present invention include a compound represented by the following formula (4) (hereinafter sometimes referred to as “cyclic carbodiimide compound (c)”).

In the formula, Q _c is a tetravalent linking group which is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may have a hetero atom. Z ¹ and Z ² are carriers that support a cyclic structure. Z ¹ and Z ² may be bonded to each other to form a cyclic structure.
The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (4), Q _c is tetravalent. Accordingly, one of these groups is a tetravalent group or two are trivalent groups.
Q _c is preferably a tetravalent linking group represented by the following formula (4-1), (4-2) or (4-3).

Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² , X _c ³ , s and k are each Ar ^{1 in} formulas (1-1) to (1-3). , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k are the same. Provided that Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² and X _c ³ are one of which is a tetravalent group or two of which are trivalent It is a group. Z ¹ and Z ² are preferably each independently a single bond, a double bond, an atom, an atomic group or a polymer. Z ¹ and Z ² are bonding portions, and a plurality of cyclic structures are bonded via Z ¹ and Z ² to form a structure represented by the formula (4).
Examples of the cyclic carbodiimide compound (c) include the following compounds.

<Method for producing cyclic carbodiimide compound>
The production method of the cyclic carbodiimide compound of the present invention is not particularly limited, and can be produced by a conventionally known method. For example, a method for producing an amine body via an isocyanate body, a method for producing an amine body via an isothiocyanate body, a method for producing an amine body via a triphenylphosphine body, a urea body from an amine body The method of manufacturing via a thiourea body, the method of manufacturing via a thiourea body, the method of manufacturing from a carboxylic acid body via an isocyanate body, the method of manufacturing a lactam body, etc. are mentioned.

Moreover, the cyclic carbodiimide compound of this invention can be manufactured by the method described in the following literature.
Tetrahedron Letters, Vol. 34, no. 32, 515-5158, 1993.
Medium- and Large-Membered Rings from Bis (iminophosphoranes): An Efficient Preparation of Cyclic Carbidiimides, Pedro Molina et al.
Journal of Organic Chemistry, Vol. 61, no. 13, 4289-4299, 1996.
New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and 1H NMR) of Cyclic Carbodiimides, Pedro Molina et al.
Journal of Organic Chemistry, Vol. 43, No8, 1944-1946, 1978.
Macrocyclic Ureas As Masked Isocynates, Henri Ulrich et al.
Journal of Organic Chemistry, Vol. 48, no. 10, 1694-1700, 1983.
Synthesis and Reactions of Cyclic Carbodiimides,
R. Richter et al.
Journal of Organic Chemistry, Vol. 59, no. 24, 7306-7315, 1994.
A New and Efficient Preparation of Cyclic Carbodiamids from Bis (iminophosphoranea) and the System Boc ₂ O / DMAP, Pedro Molina et al.

（２）得られたニトロ体を還元して下記式（ｄ）で表わされるアミン体を得る工程、

（３）得られたアミン体とトリフェニルホスフィンジブロミドを反応させ下記式（ｅ）で表されるトリフェニルホスフィン体を得る工程、および

（４）得られたトリフェニルホスフィン体を反応系中でイソシアネート化した後、直接脱炭酸させることによって製造したものは、本願発明に用いる環状カルボジイミド化合物として好適に用いることができる。
（上記式中、Ａｒ^１およびＡｒ^２は各々独立に、炭素数１〜６のアルキル基またはフェニル基で置換されていてもよい芳香族基である。Ｅ^１およびＥ^２は各々独立に、ハロゲン原子、トルエンスルホニルオキシ基およびメタンスルホニルオキシ基、ベンゼンスルホニルオキシ基、ｐ−ブロモベンゼンスルホニルオキシ基からなる群から選ばれる基である。Ａｒ^ａは、フェニル基である。Ｘは、下記式（ｉ−１）から（ｉ−３）の結合基である。） Depending on the compound to be produced, an appropriate production method may be adopted.
(1) A nitrophenol represented by the following formula (a-1), a nitrophenol represented by the following formula (a-2) and a compound represented by the following formula (b) are reacted, and the following formula ( c) obtaining a nitro compound represented by

(2) A step of reducing the obtained nitro body to obtain an amine body represented by the following formula (d);

(3) a step of reacting the obtained amine body with triphenylphosphine dibromide to obtain a triphenylphosphine body represented by the following formula (e); and

(4) After the obtained triphenylphosphine body is isocyanated in the reaction system and then directly decarboxylated, it can be suitably used as the cyclic carbodiimide compound used in the present invention.
(In the above formula, Ar ¹ and Ar ² are each independently an aromatic group optionally substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group. E ¹ and E ² are each independently a halogen atom. A group selected from the group consisting of an atom, a toluenesulfonyloxy group, a methanesulfonyloxy group, a benzenesulfonyloxy group, and a p-bromobenzenesulfonyloxy group, Ar ^a is a phenyl group, X is represented by the following formula (i -1) to (i-3).

  In addition, the cyclic carbodiimide compound can effectively seal the carboxyl group of the aromatic polyester. However, as long as it does not contradict the gist of the present invention, for example, a conventionally known polymer carboxyl group sealant may be used. Can be used together. Examples of such conventionally known carboxyl group-capping agents include agents described in JP-A-2005-2174, such as epoxy compounds, oxazoline compounds, and oxazine compounds.

<Aromatic polyester>
In the present invention, the aromatic polyester to which the cyclic carbodiimide compound is applied has a carboxyl group.
As the aromatic polyester, for example, a polymer or copolymer obtained by polycondensation of dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative, preferably a thermoplastic aromatic polyester resin is exemplified. .
Such a thermoplastic aromatic polyester resin may contain a cross-linked structure treated with a radical generation source such as an energy active ray or an oxidizing agent for moldability and the like.

  Examples of the dicarboxylic acid or ester-forming derivative thereof include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, Aromatic dicarboxylic acids such as 4,4'-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malon Examples thereof include aliphatic dicarboxylic acids such as acid, glutaric acid and dimer acid, alicyclic dicarboxylic acid units such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and ester-forming derivatives thereof.

  Examples of the diol or ester-forming derivatives thereof include aliphatic glycols having 2 to 20 carbon atoms, that is, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1, 6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, dimer diol, etc., or a long chain glycol having a molecular weight of 200 to 100,000, that is, polyethylene glycol, poly1,3-propylene glycol, poly1,2-propylene Aromatic dioxy compounds such as glycol and polytetramethylene glycol, that is, 4,4′-dihydroxybiphenyl, hydroquinone tert-butylhydroquinone, bisphenol A, bisphenol Lumpur S, and bisphenol F, and the like ester-forming derivatives thereof.

  Specific examples of these polymers or copolymers include aromatic dicarboxylic acid or an ester-forming derivative thereof and an aromatic polyester obtained by polycondensation of an aliphatic diol or an ester-forming derivative thereof as main components. An acid or an ester-forming derivative thereof, preferably terephthalic acid or naphthalene 2,6-dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol selected from ethylene glycol, propylene glycol, or butanediol or an ester-forming derivative thereof. A polymer formed by polycondensation as an example is exemplified.

  Specifically, polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polypropylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyethylene (terephthalate / isophthalate), polytrimethylene (terephthalate / isophthalate), polybutylene (terephthalate) / Isophthalate), polyethylene terephthalate / polyethylene glycol, polytrimethylene terephthalate / polyethylene glycol, polybutylene terephthalate / polyethylene glycol, polybutylene naphthalate / polyethylene glycol, polyethylene terephthalate / poly (tetramethylene oxide) glycol, polytrimethylene terephthalate / Poly (tetramethylene oxide) Glycol, polybutylene terephthalate / poly (tetramethylene oxide) glycol, polybutylene naphthalate / poly (tetramethylene oxide) glycol, polyethylene (terephthalate / isophthalate) / poly (tetramethylene oxide) glycol, polytrimethylene (terephthalate / iso) (Phthalate) / poly (tetramethylene oxide) glycol, polybutylene (terephthalate / isophthalate) / poly (tetramethylene oxide) glycol, polybutylene (terephthalate / succinate), polyethylene (terephthalate / succinate), polybutylene (terephthalate / adipate), polyethylene ( Preferred examples include terephthalate / adipate). Among them, a preferred aromatic polyester is an aromatic polyester containing at least one selected from the group consisting of butylene terephthalate, ethylene terephthalate, trimethylene terephthalate, ethylene naphthalene dicarboxylate, butylene naphthalene dicarboxylate as a main repeating unit, In particular, polyethylene terephthalate, polyethylene naphthalate, or a mixture thereof is particularly preferred from the viewpoint that the effect of improving the long-term heat deterioration resistance can be enhanced. Further, these aromatic polyesters may have a copolymer component, but from the viewpoint of heat resistance, the copolymerization amount of the copolymer component is preferably 30 mol% or less of the total repeating units of the polyester, More preferably, it is 20 mol% or less, Most preferably, it is 10 mol% or less.

  Further, as the wholly aromatic polyester, an aromatic dicarboxylic acid or an ester-forming derivative thereof, preferably terephthalic acid or naphthalene 2,6-dicarboxylic acid or an ester-forming derivative thereof and an aromatic polyhydroxy compound or an ester thereof Examples thereof include polymers formed by polycondensation with a functional derivative as a main component.

  Specifically, for example, these polyesters exemplified by poly (4-oxyphenylene-2,2-propylidene-4-oxyphenylene-terephthaloyl-co-isophthaloyl) are carbodiimide reactive components at the molecular terminals. 1 to 50 equivalents / ton of carboxyl group and / or hydroxyl group end are contained. Such end groups, particularly carboxyl groups, are preferably sealed with a cyclic carbodiimide compound in order to reduce the stability of the polyester.

  When the carboxyl end group is sealed with a carbodiimide compound, by applying the cyclic carbodiimide compound of the present invention, there is a great advantage that the carboxyl group can be sealed without producing toxic free isocyanate.

  The above-mentioned polyesters can be produced by a known method (for example, described in a saturated polyester resin handbook (written by Kazuo Yuki, Nikkan Kogyo Shimbun (issued on December 22, 1989)).

  These aromatic polyesters to which the cyclic carbodiimide compound acts can be used by adding any known additives and fillers as long as they do not lose their effectiveness by reacting with the cyclic carbodiimide compound. Examples of additives include aliphatic polyester polymers such as polycaprolactone, polybutylene succinate, and polyethylene succinate, and aliphatics such as polyethylene glycol, polypropylene glycol, and poly (ethylene-propylene) glycol in order to reduce melt viscosity. A polyether polymer can be included as an internal plasticizer or as an external plasticizer. Furthermore, inorganic fine particles and organic compounds can be added as necessary as matting agents, deodorants, flame retardants, yarn friction reducing agents, antioxidants, coloring pigments and the like.

<Mixing method of aromatic polyester and cyclic carbodiimide compound>
In this invention, a cyclic carbodiimide compound can seal a carboxyl group by mixing and reacting with aromatic polyester. The method of adding and mixing the cyclic carbodiimide compound to the aromatic polyester is not particularly limited, and a method of adding as a master batch of a solution, a melt or a polymer to be applied, or a cyclic carbodiimide compound is dissolved, dispersed or dispersed by a conventionally known method. For example, a method may be used in which an aromatic polyester solid is brought into contact with a molten liquid and the cyclic carbodiimide compound is infiltrated.

  When taking the method of adding as a solution, a melt, or a master batch of a polymer to be applied, it can be added using a conventionally known kneading apparatus. In kneading, a kneading method in a solution state or a kneading method in a molten state is preferable from the viewpoint of uniform kneading properties. The kneading apparatus is not particularly limited, and examples thereof include conventionally known vertical reaction vessels, mixing tanks, kneading tanks or uniaxial or multiaxial horizontal kneading apparatuses such as uniaxial or multiaxial ruders and kneaders. The mixing time with the aromatic polyester is not particularly specified, and depends on the mixing apparatus and mixing temperature, but is selected from 0.1 minutes to 2 hours, preferably 0.2 minutes to 60 minutes, more preferably 1 minute to 30 minutes. .

As a solvent, what is inactive with respect to an aromatic polyester and a cyclic carbodiimide compound can be used. In particular, a solvent is preferred to have affinity for both and at least partially dissolve both, or at least partially dissolve in both.
As the solvent, for example, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents, halogen solvents, amide solvents and the like can be used.

Examples of the hydrocarbon solvent include hexane, cyclohexane, benzene, toluene, xylene, heptane, decane and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and isophorone.
Examples of ester solvents include ethyl acetate, methyl acetate, ethyl succinate, methyl carbonate, ethyl benzoate, and diethylene glycol diacetate.
Examples of the ether solvent include diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, triethylene glycol diethyl ether, diphenyl ether and the like.
Examples of the halogen-based solvent include dichloromethane, chloroform, tetrachloromethane, dichloroethane, 1,1 ′, 2,2′-tetrachloroethane, chlorobenzene, dichlorobenzene and the like.
Examples of amide solvents include formamide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.
These solvents may be used alone or as a mixed solvent as desired.

  In the present invention, the solvent is applied in the range of 1 to 1,000 parts by weight per 100 parts by weight of the total of the aromatic polyester and the cyclic carbodiimide compound. If the amount is less than 1 part by weight, there is no significance in applying the solvent. The upper limit of the amount of solvent used is not particularly limited, but is about 1,000 parts by weight from the viewpoints of operability and reaction efficiency.

  When using a method in which an aromatic polyester solid is brought into contact with a liquid in which the cyclic carbodiimide compound is dissolved, dispersed or melted and the cyclic carbodiimide compound is infiltrated, a solid aromatic compound is added to the cyclic carbodiimide compound dissolved in the solvent as described above. A method of bringing a polyester into contact, a method of bringing a solid aromatic polyester into contact with an emulsion liquid of a cyclic carbodiimide compound, and the like can be employed. As a method of contacting, a method of immersing the aromatic polyester, a method of applying to the aromatic polyester, a method of spraying, etc. can be suitably employed.

  The sealing reaction with the cyclic carbodiimide compound of the present invention is possible at a temperature of room temperature (25 ° C.) to about 300 ° C., but preferably 50 to 250 ° C., more preferably 80 to 200 ° C. from the viewpoint of reaction efficiency. In the range is more promoted. The aromatic polyester is more likely to react at a melting temperature, but it is preferably reacted at a temperature lower than 300 ° C. in order to suppress volatilization and decomposition of the cyclic carbodiimide compound. It is also effective to apply a solvent in order to lower the melting temperature of the polymer and increase the stirring efficiency.

  Although the reaction proceeds sufficiently rapidly without a catalyst, a catalyst that accelerates the reaction can also be used. As a catalyst, the catalyst used with the conventional linear carbodiimide compound is applicable. For example, an alkali metal compound, an alkaline earth metal compound, a tertiary amine compound, an imidazole compound, a quaternary ammonium salt, a phosphine compound, a phosphonium salt, a phosphate ester, an organic acid, a Lewis acid, and the like can be mentioned. Or 2 or more types can be used. The addition amount of the catalyst is not particularly limited, but is preferably 0.001 to 1 part by weight, and 0.01 to 0.1 part by weight with respect to 100 parts by weight in total of the aromatic polyester and the cyclic carbodiimide compound. Is more preferable, and 0.02 to 0.1 part by weight is most preferable.

  The application amount of the cyclic carbodiimide compound is selected such that the carbodiimide group contained in the cyclic carbodiimide compound is 0.5 to 100 equivalents per equivalent of the carboxyl group. If the amount is less than 0.5 equivalent, there may be no significance in applying the cyclic carbodiimide compound. On the other hand, if it exceeds 100 equivalents, the characteristics of the substrate may be altered. From this viewpoint, on the above criteria, a range of preferably 0.6 to 100 equivalents, more preferably 0.65 to 70 equivalents, further preferably 0.7 to 50 equivalents, and particularly preferably 0.7 to 30 equivalents is selected. Is done. Further, in the present invention, the effect of improving long-term heat deterioration resistance can be enhanced by satisfying the plane orientation coefficient defined by the present invention and at the same time, by setting the application amount of the cyclic carbodiimide compound within the above numerical range.

<Composition of mixing aromatic polyester and cyclic carbodiimide compound>
The composition obtained by mixing by the above method can basically take the following modes depending on the ratio of both, the reaction time, and the like.

(1) The composition comprises the following three components:
(A) A compound having at least a cyclic structure having one carbodiimide group, in which the first nitrogen and the second nitrogen are bonded by a bonding group.
(B) Aromatic polyester.
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.

(2) The composition comprises the following two components.
(A) A compound having at least a cyclic structure having one carbodiimide group, in which the first nitrogen and the second nitrogen are bonded by a bonding group.
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.

(3) The composition comprises the following components:
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.

Here, the embodiment of (3) is not a composition but a modified aromatic polyester, but in the present invention, it is described as “composition” for convenience.
Either embodiment is preferable, but when an unreacted cyclic carbodiimide compound is present in the composition, the molecular chain of the aromatic polyester is cleaved for some reason, such as during melt molding or in a moist heat atmosphere. In this case, the reaction of the unreacted cyclic carbodiimide compound with the end of the molecular chain generated by cleavage is particularly preferable because the carboxyl group concentration can be kept low.

  In the present invention, the above description of “three components”, “two components”, and “one component” describes only the modes that the aromatic polyester and the cyclic carbodiimide compound can take in the composition. Of course, the addition of any of the above-mentioned known additives and fillers is not excluded as long as the object of the present invention is not impaired.

<Film comprising a composition in which an aromatic polyester and a cyclic carbodiimide compound are mixed>
The polyester film of the present invention is composed of a composition obtained by mixing the above-described aromatic polyester and cyclic carbodiimide compound, but when forming a film on the film, a molding technique such as extrusion molding or cast molding may be used. it can. For example, an unstretched film can be extruded using an extruder equipped with an I die, a T die, a circular die, or the like.

  When an unstretched film is obtained by extrusion molding, the unstretched film can be obtained by extruding the molten film onto a cooling drum, and then bringing the film into close contact with a rotating cooling drum and cooling. At this time, as for the method of adhering the molten film and the cooling drum, techniques such as raising the temperature of the casting drum and adhering, and techniques such as nip and electrostatic adhesion by rolls can be used, but when using the electrostatic adhesion method In addition, an electrostatic adhesive such as quaternary phosphonium salt of sulfonic acid is blended, and a charge is easily applied from the electrode to the film melting surface in a non-contact manner, thereby bringing the film into close contact with the rotating cooling drum. Can be obtained.

  Moreover, after making into a solution using the solvent which melt | dissolves a resin composition, for example, solvents, such as chloroform and a methylene dichloride, an unstretched film can also be cast-molded by cast-drying and solidifying.

  In the present invention, the unstretched film obtained above may be referred to as a mechanical flow direction (hereinafter, referred to as a longitudinal direction or a longitudinal direction or MD) in order to set the plane orientation coefficient within the range defined by the present invention. ) In the direction perpendicular to the mechanical flow direction (hereinafter sometimes referred to as the transverse direction or the width direction or TD) to form a biaxially stretched film. Examples of the stretching method include a sequential biaxial stretching method using roll stretching and tenter stretching, a simultaneous biaxial stretching method using tenter stretching, and a biaxial stretching method using tubular stretching.

  In order to set the plane orientation coefficient within the range specified by the present invention, the longitudinal draw ratio needs to be 1.7 times or more, preferably 2.1 times or more, more preferably 2.6 times or more, and 3.0 times. The above is more preferable. Further, the transverse draw ratio needs to be 2.1 times or more, preferably 2.6 times or more, more preferably 2.9 times or more, and further preferably 3.1 times or more. On the other hand, if the draw ratio is too high, breakage tends to occur frequently during film formation, and it is preferably 8 times or less in both length and width, more preferably 7 times or less, and 6 times or less. More preferably, it is more preferably 5 times or less.

  In the longitudinal stretching step, when the glass transition temperature of the aromatic polyester is Tg, the longitudinal stretching is preferably performed after preheating at (Tg-20) to (Tg + 30) ° C. The longitudinal stretching temperature is preferably (Tg-10) to (Tg + 45) ° C, and more preferably (Tg) to (Tg + 30) ° C. In the transverse stretching step, the transverse stretching is preferably performed after preheating at (Tg-20) to (Tg + 50) ° C. The transverse stretching temperature is preferably (Tg−20) to (Tg + 60) ° C., more preferably (Tg + 10) to (Tg + 50) ° C. Furthermore, in the transverse stretching step, it is particularly preferable that the temperature at the end of the transverse stretching is 4 ° C. or higher than the temperature at the beginning of the transverse stretching. In the present invention, by adopting such a stretching temperature, it becomes easier to achieve the plane orientation coefficient defined by the present invention, and a more preferable film can be obtained from the viewpoint of long-term heat deterioration resistance.

  When the crystal melting temperature of the aromatic polyester is Tm after stretching, it is preferably (Tm-110) ° C. or more and less than (Tm) ° C., preferably by heat treatment (heat setting) for 3 to 60 seconds, The heat shrinkage rate can be suitably reduced. Moreover, it becomes easy to achieve the plane orientation coefficient prescribed by the present invention. From such a viewpoint, the heat treatment temperature is preferably in the range of (Tm-70) to (Tm) ° C., more preferably (Tm-50) to (Tm-10) ° C., and more preferably (Tm-40) to (T Tm-20) ° C.

Thereafter, in order to adjust and lower the heat shrinkage rate in the vertical direction and the horizontal direction, it is preferable to perform heat relaxation treatment in the range of 0.2 to 15% in the vertical direction and / or the horizontal direction. The relaxation rate is more preferably 0.5% or more and 10% or less, and further preferably 1% or more and 6% or less. The relaxation temperature is preferably 5 ° C. or more lower than the heat treatment temperature, more preferably 20 ° C. or more, and further preferably 40 ° C. or more. Further, it is preferably higher than the glass transition temperature Tg, more preferably Tg + 20 ° C. or higher, and further preferably Tg + 40 ° C. or higher.
The stretched film thus obtained can be subjected to surface activation treatment such as plasma treatment, amine treatment, and corona treatment by a conventionally known method if desired.

<Antioxidant>
The polyester film of the present invention preferably contains an antioxidant. Antioxidants are effective when used in combination with the above-mentioned cyclic carbodiimide compounds. Although the mechanism is not clarified, it is thought that the hydrolysis resistance and heat discoloration resistance are improved by the antioxidant suppressing thermal degradation of the cyclic carbodiimide compound. As the antioxidant in the present invention, a phenolic antioxidant is preferably used because it has a high effect of suppressing the decomposition of the cyclic carbodiimide compound. Specific examples of the phenolic antioxidant include 2,6-di-tert-butyl-4-methyl-phenol, 4,4-methylenebis (2,6-di-tert-butylphenol), tetrakis [methylene 3- ( 3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] -methane, stearyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, etc. However, the present invention is not limited to these examples.

  Examples of antioxidants that can be used as antioxidants other than phenol-based antioxidants include sulfur-based and phosphorus-based antioxidants. Specifically, dilauryl-3,3′-thiodipropionate, dimyristyl-3, Sulfur-containing compounds such as 3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythrityl-tetrakis (3-laurylthiopropionate), cyclic neopentanetetraylbis (octadecyl) Phosphites), tris (nonylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite and other phosphorus-containing compounds can be exemplified. These antioxidants may be used alone or in combination of two or more, but preferably contain at least one phenolic antioxidant. Sulfur and phosphorus antioxidants are mainly used as secondary antioxidants, and when used in combination with phenolic antioxidants that act as primary antioxidants, synergistic effects are obtained, and hydrolysis resistance and discoloration are further suppressed. The effect to do increases. Among these, tetrakis [methylene 3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] -methane, which is a phenolic antioxidant, is preferable, for example, Irganox 1010 ( A registered trademark, manufactured by CiBa-Geigy) is used.

  The blending amount of the antioxidant in the present invention is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, particularly 0.1 to 1 part by weight based on 100 parts by weight of the aromatic polyester. preferable. When the blending amount is less than the lower limit, the hydrolysis resistance improvement and discoloration suppressing effect may not be sufficient. On the other hand, if the blending amount exceeds the upper limit, not only the hydrolysis resistance and discoloration suppressing effect will not be improved any more, but also the scattering of antioxidants may occur in the film forming process, and the film forming apparatus may be soiled. It may be economically disadvantageous.

  The method for adding such an antioxidant to the aromatic polyester is not particularly limited as in the means for adding the cyclic carbodiimide compound. For example, there are a method of blending in the polycondensation step of the aromatic polyester, a method of blending in the film forming step of the biaxially oriented film, etc. As the blending form, the above antioxidant is blended directly with the aromatic polyester and melted. There are a method of kneading, a method of preparing a masterbatch containing a high concentration of antioxidant in advance, and a method of blending the masterbatch. Moreover, about the mixing | blending order of a cyclic carbodiimide compound and antioxidant, you may add simultaneously, and you may add a cyclic carbodiimide compound after adding antioxidant.

<Other additives>
In order that the polyester film of this invention may improve the handleability of a film, the inert particle may be added in the range which does not impair the effect of invention. Examples of such inert particles include inorganic particles containing elements of IIA, IIB, IVA, and IVB of the periodic table (for example, kaolin, alumina, silica alumina, titanium dioxide, barium sulfate, zeolite, spherical silica). And porous silica). Moreover, the organic particle which consists of a polymer with high heat resistance, such as a crosslinked silicone resin, a crosslinked polystyrene resin, and a crosslinked acrylic resin particle, can be illustrated. The average particle diameter of the inert particles is preferably in the range of 0.001 to 5 μm. Moreover, the range of 0.01 to 10 weight% is preferable with respect to the weight of a film, and the range of 0.1 to 3 weight% is more preferable. The inert particles contained in the film may be a single component, a multi-component of two or more components, and may contain inert particles having different average particle diameters. For example, by reducing the transparency of the film, the presence of the film in the oil can be easily understood.
Moreover, the biaxially oriented film of the present invention may contain a small amount of an ultraviolet absorber, an antistatic agent, a light stabilizer, and a heat stabilizer as necessary.

<Characteristics of film>
[Plane orientation coefficient (ΔP)]
The polyester film of the present invention needs to have a plane orientation coefficient of 0.1 or more. In this invention, the film excellent in long-term heat-resistant deterioration can be obtained by using a cyclic carbodiimide compound and making a plane orientation coefficient into the said numerical range. When the plane orientation coefficient decreases, it becomes difficult to maintain mechanical strength in a high temperature environment, and long-term heat deterioration tends to be inferior. From such a viewpoint, the plane orientation coefficient is preferably 0.12 or more, more preferably 0.14 or more, and further preferably 0.16 or more.

In addition, when the plane orientation coefficient is too high, the film tends to break during film formation, and the film forming property tends to deteriorate. In addition, processing characteristics such as delamination (delamination) easily occurring during bending processing are deteriorated. From such a viewpoint, the plane orientation coefficient is preferably 0.300 or less, more preferably 0.280 or less, and further preferably 0.260 or less.
In addition, in order to make a plane orientation coefficient into the said numerical range, what is necessary is just to employ | adopt the film forming conditions mentioned above, especially the extending | stretching conditions mentioned above, and this method can be mentioned as a preferable achievement means in this invention.

[Tensile strength]
The polyester film of the present invention preferably has a longitudinal and transverse tensile strength of 110 MPa or more. When the tensile strength is in the above numerical range, strength and durability are preferable for electrical insulation, particularly for motor insulation. When the tensile strength is less than 110 MPa, it leads to a decrease in product strength, which is not preferable. From such a viewpoint, the tensile strength of the film is more preferably 160 MPa or more, and further preferably 200 MPa or more. On the other hand, if an attempt is made to obtain a film having a tensile strength exceeding 500 MPa, the elongation of the film is remarkably lowered, which may make manufacture difficult.

[Carboxyl group end concentration]
Furthermore, the polyester film of the present invention preferably has a carboxyl group terminal concentration [COOH] of 0 to 35 eq / ton. When the carboxyl group terminal concentration is higher than 35 eq / ton, the degree of hydrolysis is large, and the film strength for electrical insulation may be significantly reduced. From the viewpoint of maintaining strength, the carboxyl group terminal concentration is preferably 20 eq / ton or less, more preferably 10 eq / ton or less, and most preferably 6 eq / ton or less. The lower the carboxyl group end group concentration, the better.

[Long-term heat deterioration resistance]
When the polyester film of the present invention is allowed to stand in an environment of 180 ° C., it is preferable that the time until the breaking elongation retention becomes 50% or less is 200 hours or more. When the time is in the above numerical range, it means that long-term heat deterioration resistance is excellent, and in electrical insulation applications, the product can be extended in a high temperature environment, which is preferable. From such a viewpoint, the time until the breaking elongation retention rate reaches 50% is more preferably 250 hours or more, further preferably 300 hours or more, and particularly preferably 400 hours or more. Here, the retention rate at break elongation is represented by a value (%) obtained by dividing the break elongation in the vertical direction of the test piece that has passed for a certain time in an environment of 180 ° C. by the break elongation in the same direction before the treatment. It is.

[Hydrolysis resistance]
When the polyester film of the present invention is left in an environment of 121 ° C., 2 atm and 100% RH, it is preferable that the time until the fracture strength retention becomes 50% is 100 hours or more. When the time is in the above numerical range, it means that the long-term hydrolysis resistance is excellent, and in electrical insulation applications, the product life is extended in a high humidity environment, which is preferable. From such a viewpoint, the time until the breaking strength retention becomes 50% is more preferably 130 hours or more, still more preferably 150 hours or more, and particularly preferably 180 hours or more. Here, the breaking strength retention is the average value of the breaking strength in the longitudinal direction and the transverse direction of a test piece that has passed for a certain period of time in an environment of 121 ° C., 2 atm, and 100% RH, and the breaking strength in these directions before treatment. It is expressed as a value (%) divided by the average value of intensity.

  The polyester film of the present invention preferably has a breaking strength retention of 75% or more after 100 hours in an environment of 121 ° C., 2 atm and 100% RH, more preferably 80% or more. The upper limit of the breaking strength retention is not particularly limited and is preferably as high as possible from the viewpoint of hydrolysis resistance, but is usually less than 100%. If the breaking strength retention is less than the lower limit, the hydrolysis resistance may not be sufficient when used in applications used in a high temperature and high humidity environment. For example, when used for electrical insulation or a capacitor, the electrical insulation characteristics may deteriorate. When used for FPC applications, disconnection due to hydrolysis degradation of the PEN film base material may occur, and sufficient FPC performance may not be exhibited.

[Film thickness]
The polyester film of the present invention preferably has a film thickness in the range of 0.5 to 400 μm, more preferably 25 to 380 μm, and particularly preferably 150 to 350 μm, and is suitable for electrical insulation, particularly for motor insulation. It is. The polyester film of the present invention is usually used as a single layer, but may be a laminate as long as the effects of the invention are not impaired.

[Film density]
In the present invention, when polyethylene terephthalate is used as the aromatic polyester, the density of the polyester film is preferably 1.394 g / cm ³ or more, and the effect of improving electrical insulation can be enhanced. Further, when polyethylene naphthalate is used as the aromatic polyester, the density of the polyester film is preferably 1.359 g / cm ³ or more, and the effect of improving electrical insulation can be enhanced. On the other hand, if the density is too high, the effect of improving heat resistance tends to be low. When polyethylene terephthalate is used as the aromatic polyester, the density of the polyester film is preferably 1.405 g / cm ³ or less. From the same viewpoint, when polyethylene naphthalate is used as the aromatic polyester, the density of the polyester film is preferably 1.364 g / cm ³ or less.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, each characteristic value in an Example was calculated | required with the following method.

A. Glass transition temperature (Tg), melting point (Tm)
Using TA-2920, manufactured by TA Instrument Co., Ltd., the glass transition temperature (Tg) was determined under the condition of a heating rate of 20 ° C./min, and the peak temperature of the obtained melting peak was determined as the melting point (Tm). did.

B. Carboxyl group terminal concentration [COOH] (eq / ton)
The sample was dissolved in purified o-cresol under a nitrogen stream, and titrated with an ethanol solution of 0.05 N potassium hydroxide using bromocresol blue as an indicator.

C. Isocyanate gas generation test A sample was heated at 160 ° C. for 5 minutes, and qualitatively and quantitatively analyzed by pyrolysis GC / MS analysis. In addition, fixed_quantity | quantitative_assay was performed using the analytical curve created with isocyanate. GC / MS used was GC / MS Jms Q1000GC K9 manufactured by JEOL Ltd.

D. Film thickness Film thickness was measured at 30 g of needle pressure using an electronic micrometer (trade name “K-312A type” manufactured by Anritsu Corporation).

E. Planar orientation coefficient Using an Abbe refractometer, the refractive index was measured using sodium D line (589 nm) as a light source, and the refractive index was determined by the following formula.
Plane orientation coefficient ΔP = (nMD + nTD) / 2−nZ
Here, nMD represents the refractive index in the longitudinal direction of the film, nTD represents the refractive index in the lateral direction of the film, and nZ represents the refractive index in the thickness direction of the film.

F. Breaking elongation and breaking strength A strip-shaped sample having a length of 200 mm and a width of 10 mm was cut out in the longitudinal and transverse directions of the film and used for measurement. In accordance with the method prescribed in JIS K-7127, the elongation at break and the strength at break were measured in an environment of 25 ° C. and 65% RH using a tensile tester (manufactured by Orientec Co., Ltd., Tensilon UCT-100 type). . The distance between the initial tensile chucks was 100 mm, and the tensile speed was 100 mm / min. The measurement was performed 10 times for each direction, and the average value was obtained.

G. Hydrolysis resistance evaluation (half time of breaking strength)
A strip-shaped sample piece cut to 150 mm length x 10 mm width is prepared in the vertical and horizontal directions of the film, and it is made of stainless steel clips in an environmental tester set to 121 ° C, 2 atm, wet saturation mode, and 100% RH. Hanging. Thereafter, a sample piece was taken out every 10 hours, and the breaking strength was measured in the same manner as F for each of the longitudinal direction and the transverse direction, and the average value of the breaking strength in the longitudinal direction and the transverse direction after the treatment (X , Unit: MPa). Then, using the average value X ₀ of the longitudinal and transverse rupture strength of the pre-treatment from the measurement of the mean value X, and the F breaking strength after the treatment was calculated breaking strength retention by the following equation.
Breaking strength retention ratio (%) = (breaking strength X / initial breaking strength X ₀ ) × 100
(In the formula, the breaking strength X is the average value (unit: MPa) of the breaking strength in the longitudinal direction and the transverse direction after treatment for a predetermined time under the conditions of 121 ° C., 2 atm, 100% RH, and the initial breaking strength X ₀ is , And represents the average value (unit: MPa) of the breaking strength in the longitudinal direction and the transverse direction before the treatment.)
Sampling and measurement every 10 hours, the change in the breaking strength retention ratio with respect to the heat treatment time between the two points, the measurement point at which the breaking strength retention ratio became 50% or less and the measurement point immediately before that Was approximated by a linear function, and the heat treatment time when the breaking strength retention was 50% was determined, and was defined as the half time of the breaking strength.

H. Long-term heat resistance evaluation (half time of elongation at break)
A strip-shaped sample having a length of 200 mm and a width of 10 mm was cut out in the longitudinal direction of the film and used for measurement. The cut sample was put in a gear oven and left in an atmosphere of 180 ° C., and the sample was taken out every 10 hours. The sample taken out was naturally cooled and then subjected to a tensile test in the same manner as F described above to determine the elongation at break (Y, unit:%) after heat treatment. The value of such Y, from the longitudinal elongation at break Y ₀ Metropolitan untreated samples obtained by the above measurement F, was determined breaking elongation retention ratio by the following equation.
Breaking elongation retention (%) = (breaking elongation Y / initial breaking elongation Y ₀ ) × 100
(In the formula, the breaking elongation Y is the longitudinal breaking elongation (unit:%) after processing at 180 ° C. for a predetermined time, and the initial breaking strength Y ₀ is the longitudinal breaking elongation (unit: %) Respectively.)
Sampling and measurement every 10 hours, and the breaking elongation retention ratio with respect to the heat treatment time between the two points of the measurement point at which the breaking elongation retention ratio became 50% or less and the measurement point immediately before the measurement point. Was approximated by a linear function, the heat treatment time when the breaking elongation retention rate was 50% was determined, and was defined as the half time of breaking elongation.

I. Measurement of reduced viscosity (ηsp / c) 1.2 g of sample was dissolved in 100 ml of [tetrachloroethane / phenol = (6/4) wt% mixed solvent] and measured at 35 ° C. using an Ubbelohde viscosity tube to maintain the reduced viscosity. The rate was determined with the reduced viscosity before sample treatment as 100%.

[Reference Example 1] Preparation of polyethylene terephthalate:
Polyethylene terephthalate “TR-8580” manufactured by Teijin Fibers Limited was used as it was as polyethylene terephthalate (PET, Tg = 80 ° C., Tm = 258 ° C.). The PET had a reduced viscosity of 0.85 dl / g and a carboxyl group terminal concentration of 30 eq / ton.

[Reference Example 2] Preparation of polyethylene-2,6-naphthalenedicarboxylate:
Using 100 parts of dimethyl naphthalene-2,6-dicarboxylate and 60 parts of ethylene glycol as a transesterification catalyst, 0.03 part of manganese acetate tetrahydrate, and gradually increasing the temperature from 150 ° C. to 238 ° C. for 120 minutes A transesterification reaction was performed. On the way, when the reaction temperature reached 170 ° C., 0.024 part of antimony trioxide was added, and after the transesterification reaction, trimethyl phosphate (135 ° C. in ethylene glycol, 0.11 to 0.16 MPa for 5 hours) was added. The solution heat-treated under pressure: 0.023 parts in terms of trimethyl phosphate was added. Thereafter, the reaction product is transferred to a polymerization reactor, heated to 290 ° C., and subjected to a polycondensation reaction under a high vacuum of 27 Pa or less, and has an intrinsic viscosity of 0.61 dl / g and substantially no particles. Polyethylene-2,6-naphthalenedicarboxylate (PEN, Tg = 121 ° C., Tm = 269 ° C.) was obtained.

[Reference Example 3] Production of cyclic carbodiimide compound:
o- nitrophenol (0.11 mol) and pentaerythrityl tetra bromide (0.025 mol), potassium carbonate (0.33mol), _N, N ₂ N- dimethylformamide 200ml in reactor installed with a stirrer and a heating device After charging in an atmosphere and reacting at 130 ° C. for 12 hours, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and separated three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product D (nitro form).

  Next, intermediate product D (0.1 mol), 5% palladium carbon (Pd / C) (2 g), and 400 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction was performed in a state where hydrogen was constantly supplied at 25 ° C., and the reaction was terminated when there was no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product E (amine body) was obtained.

Next, triphenylphosphine dibromide (0.11 mol) and 150 ml of 1,2-dichloroethane were charged and stirred in a reactor equipped with a stirrer, a heating device, and a dropping funnel in an N ₂ atmosphere. A solution prepared by dissolving the intermediate product E (0.025 mol) and triethylamine (0.25 mol) in 50 ml of 1,2-dichloroethane was gradually added dropwise thereto at 25 ° C. After completion of dropping, the reaction is carried out at 70 ° C. for 5 hours. Thereafter, the reaction solution was filtered, and the filtrate was separated 5 times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and 1,2-dichloroethane was removed under reduced pressure to obtain an intermediate product F (triphenylphosphine compound).

Next, in a reactor equipped with a stirrer and a dropping funnel, di-tert-butyl dicarbonate (0.11 mol), N, N-dimethyl-4-aminopyridine (0.055 mol), dichloromethane under N ₂ atmosphere. 150 ml is charged and stirred. Thereto, 100 ml of dichloromethane in which the intermediate product F (0.025 mol) was dissolved was slowly added dropwise at 25 ° C. After dropping, react for 12 hours. Then, the compound (MW = 516) shown by the following structural formula was obtained by refine | purifying the solid substance obtained by removing dichloromethane. The structure was confirmed by NMR and IR.

[Reference Example 4] Composition of PET and cyclic carbodiimide compound:
100 parts by weight of polyethylene terephthalate (PET) of Reference Example 1 was dried at 150 ° C. for 3 hours, melt-kneaded at a cylinder temperature of 270 ° C. from the first supply port of the kneader, and then obtained by the operation of Reference Example 3. 1 part by weight of a cyclic carbodiimide compound was supplied from the second supply port and melt kneaded at a cylinder temperature of 270 ° C. to obtain a composition and pelletized. Generation of isocyanate odor was not felt during the production of the composition.

[Reference Example 5] Composition of PEN and cyclic carbodiimide compound:
After drying 100 parts by weight of polyethylene-2,6-naphthalenedicarboxylate (PEN) obtained in the operation of Reference Example 2 at 170 ° C. for 5 hours, the cylinder temperature is 290 ° C. from the first supply port of the kneader. After melt-kneading, 1 part by weight of the cyclic carbodiimide compound obtained by the operation of Reference Example 3 was supplied from the second supply port and melt-kneaded at a cylinder temperature of 290 ° C. to obtain a composition and pelletized. Generation of isocyanate odor was not felt during the production of the composition.

[Example 1]
The pellets of the composition having a melting point of 256 ° C. and a carboxyl group terminal concentration of 5 eq / ton obtained in Reference Example 4 were dried in a hot air dryer set at 150 ° C. for 3 hours. The dried pellets were melt-extruded into a sheet at a die temperature of 270 ° C., adhered to the surface of the mirror cooling drum by an electrostatic casting method and solidified using a platinum-coated linear electrode, and an unstretched film was obtained.
The obtained unstretched film was stretched 3.6 times in the machine direction at 100 ° C., then 3.8 times in the transverse direction at 120 ° C., heat-fixed at 220 ° C. for 15 seconds, and then 205 in the transverse direction. A relaxation treatment of 2% was performed at 0 ° C. to obtain a biaxially stretched film having a thickness of 150 μm. At this time, an irritating odor derived from isocyanate gas was not felt in the process of extrusion, film formation, stretching, and heat setting. The properties of the obtained film are shown in Table 1.

[Examples 2 and 3]
In Example 1, a film was obtained in the same manner as in Example 1 except that the film forming conditions of the film were as shown in Table 1. At this time, an irritating odor derived from isocyanate gas was not felt in the process of extrusion, film formation, stretching, and heat setting. The properties of the obtained film are shown in Table 1.

[Example 4]
The pellets of the composition having a melting point of 260 ° C. and a carboxyl group terminal concentration of 5 eq / ton obtained in Reference Example 5 were dried for 5 hours in a hot air drier set at 170 ° C. The dried pellet was melt-extruded into a sheet at a die temperature of 290 ° C., adhered to the surface of the mirror-cooled drum by an electrostatic casting method using a platinum-coated linear electrode, and solidified to obtain an unstretched film.
The obtained unstretched film was stretched 3.0 times in the machine direction at 125 ° C., then 3.2 times in the transverse direction at 135 ° C., further heat-set at 220 ° C. for 15 seconds, and then 205 in the transverse direction. A relaxation treatment of 2% was performed at 0 ° C. to obtain a biaxially stretched film having a thickness of 150 μm. At this time, an irritating odor derived from isocyanate gas was not felt in the process of extrusion, film formation, stretching, and heat setting. The properties of the obtained film are shown in Table 1.
As shown in Table 1, the films obtained in Examples 1 to 4 had a high plane orientation coefficient, as a result, good long-term heat deterioration resistance, and had excellent characteristics as a film for electrical insulation. .

[Comparative Example 1]
A film was obtained in the same manner as in Example 1 except that the film forming conditions were as shown in Table 1. The properties of the obtained film are shown in Table 1. In the process of extrusion, film formation, stretching, and heat setting in Comparative Example 1, no irritating odor derived from isocyanate gas was felt.

[Comparative Example 2]
A film was obtained in the same manner as in Example 4 except that the film forming conditions were as shown in Table 1. The properties of the obtained film are shown in Table 1. In the process of extrusion, film formation, stretching, and heat setting in Comparative Example 2, no irritating odor derived from isocyanate gas was felt.
As shown in Table 1, the films obtained in Comparative Examples 1 and 2 had a low plane orientation coefficient. As a result, the long-term heat deterioration resistance was inferior, and the properties were slightly insufficient as a film for electrical insulation.

[Comparative Example 3]
To 100 parts by weight of the polyethylene terephthalate resin of Reference Example 1, 1 part by weight of a commercially available linear polycarbodiimide compound (“Carbodilite LA-1” manufactured by Nisshinbo Chemical Co., Ltd.) at 270 ° C. using a twin screw extruder Using pellets obtained by kneading, a biaxially stretched film having a thickness of 150 μm was prepared in the same manner as in Example 1. In Comparative Example 3, there was an irritating odor derived from isocyanate during the film forming process. Further, when an isocyanate gas generation test was performed on the obtained film, 10 ppm of isocyanate gas was generated.

  The film of the present invention is excellent in hydrolysis resistance, has high heat deterioration resistance, and can maintain high mechanical properties over a long period of time in a high temperature use environment.For example, for electrical insulation, for motor insulation, In particular, it can be suitably used for motor insulation used in electric vehicles and the like, and its industrial value is high.

Claims (18)

  It is composed of a composition in which an aromatic polyester is mixed with a compound containing at least a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded by a bonding group, and the plane orientation coefficient is 0. A polyester film for electrical insulation which is 1 or more.   The polyester film for electrical insulation according to claim 1, wherein the number of atoms forming the cyclic structure is 8 to 50. The polyester film for electrical insulation according to claim 1, wherein the ring structure is represented by the following formula (1).

(In the formula, Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.) The polyester film for electrical insulation according to claim 3, wherein Q is a divalent to tetravalent linking group represented by the following formula (1-1), (1-2) or (1-3).

(In the formula, Ar ¹ and Ar ² are each independently an aromatic group having 2 to 4 carbon atoms and 5 to 15 carbon atoms. R ¹ and R ² are each independently 1 to 2 carbon atoms having 1 to 4 carbon atoms. 20 aliphatic groups, 2 to 4 valent alicyclic groups having 3 to 20 carbon atoms, or combinations thereof, or these aliphatic groups, alicyclic groups and 2 to 4 valent aromatic carbon atoms having 5 to 15 carbon atoms X ¹ and X ² are each independently a divalent to tetravalent aliphatic group having 1 to 20 carbon atoms, a divalent to tetravalent carbon atom having 3 to 20 alicyclic groups, 2 to 4 A valent aromatic group having 5 to 15 carbon atoms, or a combination thereof, s is an integer of 0 to 10. k is an integer of 0 to 10. When s or k is 2 or more, X ¹ or X ² as a repeating unit may be different from other X ¹ or X ^2. X ³ is a divalent to tetravalent carbon number. An aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 2 to 4 carbon atoms having 3 to 20 carbon atoms, an aromatic group having 2 to 4 carbon atoms having 5 to 15 carbon atoms, or a combination thereof, provided that Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ may contain a hetero atom, and when Q is a divalent linking group, Ar ¹ , Ar ² , R 3 ¹ , R ² , X ¹ , X ² and X ³ are all divalent groups, and when Q is a trivalent linking group, Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ^{One of 2} and X ³ is a trivalent group, and when Q is a tetravalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ One of them is a tetravalent group or two are trivalent groups.) The polyester film for electrical insulation according to claim 1, wherein the compound containing a cyclic structure is represented by the following formula (2).

(Wherein Q _a is a divalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.) Q _a is represented by the following formula (2-1), (2-2) or a divalent electrical insulating polyester film according to claim 5, wherein the linking group represented by (2-3).

(In the formula, Ar _a ¹ , Ar _a ² , R _a ¹ , R _a ² , X _a ¹ , X _a ² , X _a ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. The same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k in the inside.) The polyester film for electrical insulation according to claim 1, wherein the compound containing a cyclic structure is represented by the following formula (3).

(Wherein Q _b is a trivalent linking group which is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom. Y represents a cyclic structure. It is a carrier to be supported.) Q _b is represented by the following formula (3-1), (3-2) or trivalent electrically insulating polyester film according to claim 7, wherein the linking group represented by (3-3).

(In the formula, Ar _b ¹ , Ar _b ² , R _b ¹ , R _b ² , X _b ¹ , X _b ² , X _b ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s, and k, with one of these being a trivalent group.)   The polyester film for electrical insulation according to claim 7, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer. The polyester film for electrical insulation according to claim 1, wherein the compound containing a cyclic structure is represented by the following formula (4).

(Wherein Q _c is a tetravalent linking group that is an aliphatic group, an aromatic group, an alicyclic group, or a combination thereof, and may have a hetero atom. Z ¹ and Z ² are A carrier carrying a ring structure.) 11. The polyester film for electrical insulation according to claim 10, wherein Q _c is a tetravalent linking group represented by the following formula (4-1), (4-2), or (4-3).

(In the formula, Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² , X _c ³ , s and k are respectively represented by formulas (1-1) to (1-3) Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k, provided that one of them is a tetravalent group or two are 3 Valent group.) The electrically insulating polyester film according to claim 10, wherein Z ¹ and Z ² are each independently a single bond, a double bond, an atom, an atomic group or a polymer.   The polyester film for electrical insulation according to any one of claims 1 to 12, wherein the aromatic polyester is polyethylene terephthalate.   The polyester film for electrical insulation according to any one of claims 1 to 12, wherein the aromatic polyester is polyethylene naphthalate. The polyester film for electrical insulation according to claim 1, wherein the composition comprises the following three components.
(A) a compound including at least a cyclic structure in which one carbodiimide group is bonded to the first nitrogen and the second nitrogen by a bonding group;
(B) aromatic polyester,
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group. The polyester film for electrical insulation according to claim 1, wherein the composition comprises the following two components.
(A) a compound including at least a cyclic structure in which one carbodiimide group is bonded to the first nitrogen and the second nitrogen by a bonding group;
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group. The polyester film for electrical insulation according to claim 1, wherein the composition comprises the following one component.
(C) An aromatic polyester in which a carboxyl group is sealed with a compound having at least a cyclic structure in which one carbodiimide group is included and the first nitrogen and the second nitrogen are bonded by a bonding group.   It is an object for motor insulation, The polyester film for electrical insulation of any one of Claims 1-17 characterized by the above-mentioned.