JP5475530B2 - Biaxially stretched film - Google Patents

Description

  The present invention relates to a biaxially stretched film made of a composition in which a terminal of a polymer compound mainly composed of an aromatic polyester is sealed with a carbodiimide compound.

  It has already been proposed to suppress hydrolysis by applying a carbodiimide compound to a film made of a polymer compound, for example, a film made of an aromatic polyester (Patent Documents 1 and 2). The carbodiimide compound used in these proposals 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.

JP 2010-031174 A JP 2007-099971 A

  An object of the present invention is to provide an excellent strength retention property in a humid heat environment, comprising a composition in which the end of a polymer compound mainly composed of an aromatic polyester is sealed with a carbodiimide compound without liberating an isocyanate compound. It is to provide an axially stretched film.

As a result of intensive studies, the present inventors have completed the present invention. That is, the object of the present invention is to
A composition comprising a compound containing at least a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded to each other by a bonding group and a polymer compound mainly composed of an aromatic polyester. The biaxially stretched film having a breaking strength in the longitudinal direction and the transverse direction of 140 MPa 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。）
３．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の二軸延伸フィルム。

（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。） Further, the present invention includes the following.
1. Said biaxially stretched film whose number of atoms which forms a cyclic structure is 8-50.
2. Said biaxially stretched film whose cyclic structure is represented by 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.)
3. Q is the above biaxially stretched film, which 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.)

（式中、Ｑａ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。）
５．Ｑａ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の二軸延伸フィルム。

（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。） 4). The biaxially stretched film, wherein the compound containing a cyclic structure is represented by the following formula (2).

(In the formula, Qa 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.)
5. Qa is the above biaxially stretched film, which is 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 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.)

（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。）
７．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の二軸延伸フィルム。

（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。）
８．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の二軸延伸フィルム。 6). The biaxially stretched film, 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.)
7). Q _b is represented by the following formula (3-1), (3-2) or the biaxially oriented film is a trivalent 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.)
8). Y is a biaxially stretched film as described above, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer.

（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。）
１０．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の二軸延伸フィルム。

（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。） 9. The biaxially stretched film, 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.)
10. Q _c is the above biaxially stretched film which 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.)

11. The above biaxially stretched film, wherein Z ¹ and Z ² are each independently a single bond, a double bond, an atom, an atomic group or a polymer.
12 The above biaxial stretching, wherein the 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 and butylene naphthalene dicarboxylate as a main repeating unit. the film.
13. The biaxially stretched film as described 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) a polymer compound mainly composed of an aromatic polyester,
(C) a polymer mainly composed of 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 linking group. Compound.
14 The biaxially stretched film as described 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) a polymer mainly composed of 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 linking group. Compound.
15. The biaxially stretched film as described above, wherein the composition comprises the following one component.
(C) a polymer mainly composed of 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 linking group. Compound.

  ADVANTAGE OF THE INVENTION According to this invention, the biaxially stretched film which consists of a composition by which the terminal of the high molecular compound which has aromatic polyester as a main component 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. Moreover, the biaxially stretched film excellent in the intensity | strength retainability in a wet heat environment can be provided.

Hereinafter, the present invention will be described in detail.
<Annular structure>
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 ring structure means the number of atoms that directly constitute the ring structure, and is, for example, 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.
Qb 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. Z1 and Z2 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.

<Polymer compound mainly composed of aromatic polyester>
In the present invention, a polymer compound mainly composed of an aromatic polyester to which a cyclic carbodiimide compound is applied (hereinafter sometimes referred to as an aromatic polyester polymer compound) has a carboxyl group as an acidic group. Here, “mainly” means that 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more of the polymer compound is an aromatic polyester.

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 / iphthalate), polytrimethylene (terephthalate / isophthalate), polybutylene (terephthalate / 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) Recall, 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, Particularly preferred are polyethylene terephthalate and polyethylene naphthalate.

  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)).

  Further, examples of the aromatic polyester of the present invention include unsaturated polyester resins obtained by copolymerizing unsaturated polyvalent carboxylic acids or ester-forming derivatives thereof, and polyester elastomers containing a low-melting polymer segment in addition to the polyester. The

  Examples of the unsaturated polycarboxylic acid include maleic anhydride, tetrahydromaleic anhydride, fumaric acid, endomethylenetetrahydromaleic anhydride and the like. Various monomers are added to the unsaturated polyester in order to control the curing characteristics, and it is cured by curing with active energy rays such as thermal cure, radical cure, light, and electron beam. Molded. In such unsaturated resins, control of the carboxyl group is an important technical issue regarding rheological properties such as thixotropy, resin durability, etc., but the cyclic carbodiimide compound seals the carboxyl group without producing toxic free isocyanate, The industrial significance of the advantage of being able to control and even more effectively increasing the molecular weight is great.

  Furthermore, in the present invention, the aromatic polyester may be a polyester elastomer obtained by copolymerizing a soft component. The polyester elastomer is a copolymer comprising a high-melting point hard polyester segment and a low-melting point polymer segment having a molecular weight of 400 to 6,000 as described in known literature, for example, JP-A No. 11-92636. The melting point when a high polymer is formed with only constituent components is 150 ° C. or higher, and is produced from polyalkylene glycols or aliphatic dicarboxylic acids having 2 to 12 carbon atoms and aliphatic glycols having 2 to 10 carbon atoms It is a thermoplastic polyester block copolymer comprising a constituent having a melting point or softening point of 80 ° C. or lower when measured only with a low-melting polymer segment constituent composed of a group polyester. Such an elastomer has a problem in hydrolytic stability. However, the cyclic carbodiimide compound has great industrial significance in that it can control the carboxyl group and can suppress or increase the decrease in molecular weight without safety problems.

These aromatic polyester-based polymer compounds on which the cyclic carbodiimide compound acts can be used by adding any known additives and fillers as long as they do not lose their efficacy 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.
The biaxially stretched film obtained from these raw materials preferably has a carboxyl group terminal concentration [COOH] of 0 to 10 eq / ton.

  When the carboxyl group terminal concentration is higher than 10 eq / ton, the degree of hydrolysis tends to increase, and the film strength may be significantly reduced by, for example, wet heat treatment. 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 even more preferably 6 eq / ton or less. The lower the carboxyl group end group concentration, the better.

<Mixing method of aromatic polyester polymer compound and cyclic carbodiimide compound>
In this invention, a cyclic carbodiimide compound can be sealed with a carboxyl group by mixing and reacting with an aromatic polyester polymer compound having a carboxyl group. The method of adding and mixing the cyclic carbodiimide compound to the aromatic polyester polymer compound 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 by a conventionally known method. For example, a method in which a solid of an aromatic polyester polymer compound is brought into contact with a dissolved, dispersed, or melted liquid and the cyclic carbodiimide compound is permeated can be used.

  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 polymer compound is not particularly specified, and depends on the mixing apparatus and the mixing temperature, but is 0.1 to 2 hours, preferably 0.2 to 60 minutes, more preferably 1 to 30 minutes. Is selected.

  As the solvent, those which are inactive with respect to the aromatic polyester polymer compound and the 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 polymer compound 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 a solid of an aromatic polyester polymer compound is brought into contact with a liquid in which the cyclic carbodiimide compound is dissolved, dispersed or melted and the cyclic carbodiimide compound is permeated, the cyclic carbodiimide compound dissolved in the solvent as described above is used. A method of bringing a solid aromatic polyester polymer compound into contact with each other, a method of bringing a solid aromatic polyester polymer compound 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 polymer compound, a method of applying to the aromatic polyester polymer compound, 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 polymer compound is more likely to react at a melting temperature, but 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 part per 100 parts by weight in total of the aromatic polyester polymer compound and the cyclic carbodiimide compound. 0.1 part by weight is more preferable, and 0.02 to 0.1 part by weight is even more 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, at the same time as satisfying the breaking strength defined by the present invention, the effect of improving strength retention in a humid heat environment can be enhanced by setting the amount of the cyclic carbodiimide compound within the above numerical range. .

<Composition of mixing an aromatic polyester polymer compound and a 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) An aromatic polyester polymer compound having a carboxyl group.
(C) An aromatic polyester polymer compound 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 polymer compound 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 polymer compound 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 polymer compound, but in the present invention, it is described as “composition” for convenience.

  Any embodiment is preferable, but when an unreacted cyclic carbodiimide compound is present in the composition, the molecule of the aromatic polyester-based polymer compound is caused by some factor such as melt-heating or wet heat atmosphere. When the chain is cleaved, the unreacted cyclic carbodiimide compound reacts with the molecular chain terminal generated by the cleaving, so that the carboxyl group concentration can be kept low, which is particularly preferable.

  In the present invention, the description of the above “three components”, “two components”, and “one component” is an embodiment in which an aromatic polyester polymer compound having a carboxyl group and a cyclic carbodiimide compound can take in the composition. Needless to say, it does not exclude the addition of all the above-mentioned known additives and fillers as long as the object of the present invention is not impaired.

<Film comprising a composition obtained by mixing an aromatic polyester polymer compound and a cyclic carbodiimide compound>
The method for obtaining the biaxially stretched film of the present invention is not particularly limited, and an unstretched film obtained by extrusion molding or cast molding can be stretched in the biaxial direction. In particular, in the present invention, a method in which an unstretched film is obtained by extrusion molding and the unstretched film is stretched biaxially in a direction perpendicular to the mechanical flow direction and the mechanical flow direction is preferable.

Below, the preferable manufacturing method in this invention is demonstrated.
(Extrusion and casting process)
First, a composition obtained by mixing the above-described aromatic polyester polymer compound and a cyclic carbodiimide compound is dried at a temperature of 120 to 200 ° C. for several hours using a dryer to sufficiently remove moisture in the composition. Thus, hydrolysis of the polyester polymer compound in the extruder can be suppressed. Next, using an extruder equipped with an I die or a T die, the molten film is extruded from the die at a melt extrusion temperature of 250 to 330 ° C., and the molten film is grounded on a cooling drum at a temperature of 20 to 120 ° C. Next, the film is brought into close contact with the cooling drum and sufficiently cooled and solidified to obtain an unstretched film. As a method for closely adhering the molten film and the cooling drum in such a process, a technique of increasing the temperature of the cooling drum to adhere, a technique such as a nip using a roll or electrostatic adhesion can be used. Among them, it is preferable to use an electrostatic adhesion method. In this case, an electrostatic adhesion agent such as a quaternary phosphonium salt of sulfonic acid is blended in the film, and a charge is easily applied from the electrode to the film melting surface in a non-contact manner. And an unstretched film with few surface defects can be obtained by sticking a molten film to the rotating cooling drum.

(Stretching process)
Next, the unstretched film obtained above is, for example, a mechanical flow direction (hereinafter sometimes referred to as a longitudinal direction or MD) and a direction perpendicular to the mechanical flow direction (hereinafter referred to as a transverse direction or TD). May be biaxially stretched). Examples of the biaxial stretching method include a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method by tenter stretching, and a biaxial stretching method by tubular stretching.
In the present invention, a sequential biaxial stretching method by roll stretching and tenter stretching is particularly preferable, and a film having a breaking strength defined by the present invention can be stably obtained. Hereinafter, a preferable embodiment in the stretching method will be described.
By passing the unstretched film obtained above through a roll heated to a temperature (Tg-40) to (Tg + 30) ° C. range (where Tg is the glass transition temperature of the aromatic polyester polymer compound). Preheat and then stretch at a temperature (Tg-10) to (Tg + 45) ° C., preferably (Tg) to (Tg + 30) ° C. in the machine direction 2 to 5 times, preferably 2.5 to 4.5 times, more preferably Is stretched 3.0 to 4.0 times to obtain a uniaxially stretched film. Next, the obtained uniaxially stretched film is guided to a tenter and preheated by passing through a hot air heating zone at a temperature (Tg-20) to (Tg + 50) ° C., and then the temperature (Tg) to (Tg + 60) ° C., preferably (Tg + 10) to (Tg + 50) ° C., more preferably (Tg + 20) to (Tg + 40) ° C. in the transverse direction with a draw ratio of 2 to 5 times, preferably 2.5 to 4.5 times, more preferably 3.0 to 4 Stretch to 0 times. By adopting such a stretching temperature and a stretching ratio, it is easy to achieve the breaking strength defined by the present invention, and a biaxially stretched film that is superior in strength retention in a moist heat environment can be obtained.

(Heat setting process)
Next, the range is (Tm-150) to (Tm + 10) ° C. (where Tm is the melting point of the aromatic polyester polymer), preferably (Tm-110) to (Tm) ° C., more preferably (Tm-70). ) To (Tm-10) [deg.] C., heat treatment is preferably performed for 1 to 180 seconds, preferably 3 to 60 seconds, and the film is heat-set. By heat-fixing the film in this way, it is easy to achieve the breaking strength defined by the present invention, and a biaxially stretched film that is more excellent in strength retention in a moist heat environment can be obtained.

(Relaxation process)
After heat setting, it is preferable to perform relaxation heat treatment at a relaxation rate of 0.5 to 20%, preferably 1 to 10% in the temperature range of 90 ° C. to the heat setting temperature, and the heat shrinkage rate can be reduced. .

(Other stretching processes)
In the present invention, after biaxial stretching as described above, a method of re-stretching in the machine direction and / or the transverse direction, or stretching in multiple stages can be appropriately employed, The strength can also be increased.
Thus, the biaxially stretched film of the present invention can be obtained.

The biaxially stretched film of the present invention is preferably a biaxially stretched film obtained by the above-described production method. Although it can be set as a high intensity | strength film by being biaxially stretched, according to the above-mentioned manufacturing method, the improvement effect of the intensity | strength retention property in wet-heat environment can be made high. In addition, properties such as film thickness unevenness, rigidity, dimensional stability, flatness, gas barrier properties, surface properties, heat resistance, and hydrolysis resistance can be improved.
The biaxially 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.

  The high-strength film with improved moisture and heat resistance obtained by the present invention is a polarizing plate protective film used for liquid crystal displays and the like, other optical films, solar cell back surface protective film, electrical insulation film, agricultural multi-layer film. Film, label film, packaging film, capacitor film (for example, film having a thickness of 3 μm or less), printer ribbon film (for example, film having a thickness of about 5 μm), heat-sensitive stencil printing film, magnetic recording film (for example, QIC tape) For: computer recording film 1/4 inch tape), non-glare film (for example, a film with a thickness of 50 μm or less), antireflection film, reflection film, light diffusion film, retardation film, transparent conductive film, brightness enhancement film, protection Film, release fee Beam, gas or water vapor transmission preventing film, dry photoresist film, for electronic components, for FPC, metal lamination, photographic, surface protective film, it is useful in such a fuel cell member.

<Characteristics of biaxially stretched film>
(Breaking strength)
The biaxially stretched film of the present invention has a breaking strength in the longitudinal direction and the transverse direction of 140 MPa or more, respectively. Thereby, it uses suitably in the use which requires high intensity | strength. Moreover, in this invention, the intensity | strength retainability in a humid heat environment can be made high by using the cyclic carbodiimide compound in this invention, and making break strength into the said numerical range. From such a viewpoint, the breaking strengths in the longitudinal direction and the transverse direction are each preferably 160 MPa or more, more preferably 180 MPa or more, and further preferably 210 MPa or more.
In addition, when the film has such a high strength, it is excellent in workability and processing characteristics in various processing steps, and can withstand long-term use without being cut even by strong tension changes in magnetic tapes and the like. There is. The upper limit of the breaking strength is not particularly limited, but is substantially 400 MPa or less, preferably 350 MPa or less from the viewpoint of productivity.

(Breaking strength retention)
Strength retention in a humid heat environment is evaluated by the breaking strength retention. In the present invention, the breaking strength retention after standing for 100 hours in a moist heat environment of a temperature of 121 ° C., a pressure of 2 atm, and a humidity of 100% RH is 50% or more, preferably 70% or more, more preferably 80% or more. Particularly preferably, it can be judged as a good level if it is 90% or more. When the breaking strength retention rate is good, the life of the film can be extended even when it is used in contact with a liquid and the environment continues for a long time at a high temperature, for example, for fuel cells or for reinforcing a solid polymer electrolyte membrane. Since it becomes long, the lifetime of a fuel cell or a solid polymer electrolyte membrane can be lengthened thereby.

<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。 Depending on the compound to be produced, an appropriate production method may be employed. For example, (1) nitrophenols represented by the following formula (a-1), nitrophenols represented by the following formula (a-2) And a compound represented by the following formula (b) to obtain a nitro compound represented by the following formula (c),

(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 polymer compound. However, as long as it does not contradict the gist of the present invention, for example, the carboxyl group of a conventionally known polymer may be used. A sealant can be used in combination. 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.

  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. Melting point and glass transition temperature Using TA-2920, manufactured by TA Instrument Co., Ltd., measurement was performed under the condition of a heating rate of 20 ° C./min, and the peak temperature of the obtained melting peak was defined as the melting point (Tm).
Further, using TA-2920, the sample was heated to 250 ° C. at 10 ° C./min in a nitrogen stream in the first cycle, and the glass transition temperature (Tg) was measured.

B. Carboxyl group terminal concentration [COOH] (eq / ton)
Carboxyl group concentration: 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. Breaking strength From the obtained film sample, using a strip-shaped sample piece cut to a length of 150 mm in the measurement direction and a width of 10 mm in the perpendicular direction, the tensile strength tester manufactured by A & D Corporation conforms to the JIS L1013 test method. Then, a tensile test was carried out at a distance between chucks of 100 mm and a pulling speed of 5 cm / min. The maximum value and the minimum value were excluded from the measured values of 7 times, and the average value of 5 times was taken as the breaking strength. The measurement was carried out in the longitudinal and lateral directions of the film.

E. Hydrolytic stability (strength retention evaluation under wet heat environment)
From the obtained film sample, a strip-shaped sample piece cut to a length of 150 mm in the vertical direction and a width of 10 mm in the horizontal direction is left in an environmental test machine set to 121 ° C., 2 atm, 100% RH for a predetermined time (100 hours). did. Thereafter, the sample piece was taken out, and the breaking strength was measured 7 times by the same method as in the above D. Excluding the maximum value and the minimum value, the average value of 5 times was obtained to obtain the breaking strength after the treatment. The value obtained by dividing the value of the rupture strength after the treatment by the value of the rupture strength (longitudinal direction) before the treatment (before standing) determined above was defined as the rupture strength retention rate (%).
Breaking strength retention rate (%) = ((breaking strength after 100 hours treatment) / (breaking strength before treatment)) × 100

F. Measurement of reduced viscosity (ηsp / c) 1.2 mg 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] Aromatic polyester polymer: Production of polyethylene terephthalate Using dimethyl terephthalate and ethylene glycol, manganese acetate as transesterification catalyst, antimony trioxide as polymerization catalyst, and phosphorous acid as stabilizer Polymerization was conducted by a conventional method to obtain polyethylene terephthalate (PET, Tg = 80 ° C., Tm = 258 ° C.) having an intrinsic viscosity (orthochlorophenol, 35 ° C.) of 0.62. The carboxyl group terminal concentration was 30 eq / ton.

[Reference Example 2] Aromatic polyester polymer: Production of polyethylene naphthalate 100 parts of dimethyl 2,6-naphthalenedicarboxylate and 60 parts of ethylene glycol, 0.03 part of manganese acetate tetrahydrate as a transesterification catalyst The transesterification reaction was carried out for 120 minutes while gradually raising the temperature from 150 ° C to 238 ° C. 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 (1):
Reaction in which 200 ml of o-nitrophenol (0.11 mol), 1,2-dibromoethane (0.05 mol), potassium carbonate (0.33 mol), and N, N-dimethylformamide (DMF) were installed with a stirrer and a heating device The apparatus was charged in an N ₂ atmosphere and reacted at 130 ° C. for 12 hours. After that, 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 A (nitro form).
Next, intermediate product A (0.1 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction is performed in a state where hydrogen is constantly supplied at 25 ° C., and the reaction is terminated when there is no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.
Next, in a reactor equipped with a stirrer, a heating device, and a dropping funnel, triphenylphosphine dibromide (0.11 mol) and 150 ml of 1,2-dichloroethane are charged and stirred in an N ₂ atmosphere. A solution prepared by dissolving intermediate product B (0.05 mol) and triethylamine (0.25 mol) in 50 ml of 1,2-dichloroethane is 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 C (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 was charged and stirred. Thereto, 100 ml of dichloromethane in which the intermediate product C (0.05 mol) was dissolved was slowly added dropwise at 25 ° C. After dropping, react for 12 hours. Thereafter, the solid obtained by removing dichloromethane was purified to obtain a cyclic carbodiimide compound (MW = 252) represented by the following structural formula. This structure was confirmed by NMR and IR.

[Reference Example 4] Production of cyclic carbodiimide compound (2):
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 5] Composition (1) of polymer compound and cyclic carbodiimide compound:
100 parts by weight of polyethylene terephthalate obtained in the operation of Reference Example 1 was vacuum dried at 150 ° C. for 3 hours, and then vacuumed from the first supply port of the biaxial kneader at a cylinder temperature of 270 ° C. and a vent pressure of 13.3 Pa. After melting and kneading while evacuating, 1 part by weight of the cyclic carbodiimide compound (1) obtained by the operation of Reference Example 3 is supplied from the second supply port, melted and kneaded at a cylinder temperature of 270 ° C., extruded into a water tank, and extruded into a chip cutter. And pelletized. Generation of isocyanate odor was not felt during the production of the composition.

[Reference Example 6] Composition (2) of polymer compound and cyclic carbodiimide compound:
In the operation of Reference Example 5, the same operation was performed except that the cyclic carbodiimide compound obtained by the operation of Reference Example 4 was used. Generation of isocyanate odor was not felt during the production of the composition.

[Reference Example 7] Composition (3) of polymer compound and cyclic carbodiimide compound:
After 100 parts by weight of polyethylene-2,6-naphthalene dicarboxylate obtained in the operation of Reference Example 2 was vacuum dried at 170 ° C. for 3 hours, the cylinder temperature was 290 ° C. from the first supply port of the biaxial kneader. After melting and kneading, 1 part by weight of the cyclic carbodiimide compound (1) obtained by the operation of Reference Example 3 is supplied from the second supply port, melted and kneaded at a cylinder temperature of 290 ° C., extruded into a water tank, and pelletized with a chip cutter. Turned into. Generation of isocyanate odor was not felt during the production of the composition.

[Reference Example 8] Composition (4) of polymer compound and cyclic carbodiimide compound:
In the operation of Reference Example 7, a composition was obtained by performing the same operation except that the cyclic carbodiimide compound obtained by the operation of Reference Example 4 was used. Generation of isocyanate odor was not felt during the production of the composition.

[Example 1]
The pellets of polyethylene terephthalate (carboxyl terminal concentration 0 eq / ton) obtained in Reference Example 5 were dried in a vacuum dryer set at 160 ° C. for 4 hours. The dried pellets were supplied to an extruder, melted at a melting temperature of 290 ° C., extruded from a die slit, and cooled and solidified on a casting roll having a surface temperature of 45 ° C. to obtain an unstretched film. During this extrusion, no irritating odor derived from isocyanate gas was felt.
This unstretched film was preheated by bringing it into contact with a preheating roll having a roll temperature of 80 to 110 ° C, and stretched 3.3 times in the machine direction at 120 ° C. Then, the obtained uniaxially stretched film was guided to a stenter, preheated by passing through a preheated zone at 90 to 110 ° C., stretched 3.5 times in the transverse direction at 130 ° C., and further at 225 ° C. for 15 seconds. The film was heat-set under the conditions, and then subjected to a 3% relaxation treatment in the transverse direction at 175 ° C. to obtain a biaxially stretched film having a thickness of 38 μm. In addition, the irritating odor derived from isocyanate gas was not felt in the process of film formation, extending | stretching, and heat setting.
The evaluation results of the biaxially stretched film obtained in Example 1 were as follows.
Isocyanate gas generation test: Isocyanate was not detected.
Breaking strength (before treatment): MD: 220 MPa, TD: 230 MPa
Breaking strength (after treatment): MD: 160 MPa, TD: 175 MPa
Hydrolysis resistance (breaking strength retention): MD 73%, TD: 76%

[Example 2]
Except for using polyethylene terephthalate pellets (carboxyl group terminal concentration 5 eq / ton) obtained in Reference Example 6 with a longitudinal draw ratio of 3.5 times and a transverse draw ratio of 3.8 times, the same as in Example 1. A biaxially stretched film having a thickness of 38 μm was obtained.
The evaluation results of the biaxially stretched film obtained in Example 2 were as follows.
Isocyanate gas generation test: Isocyanate was not detected.
Breaking strength (before treatment): MD: 240 MPa, TD: 255 MPa
Breaking strength (after treatment): MD: 180 MPa, TD: 197 MPa
Hydrolysis resistance (breaking strength retention): MD: 75%, TD: 77%

[Example 3]
The pellets of polyethylene naphthalate (carboxyl group terminal concentration 0 eq / ton) obtained in Reference Example 7 were dried in a vacuum dryer set at 170 ° C. for 5 hours. The dried pellets were supplied to an extruder, melted at a melting temperature of 290 ° C., extruded through a die slit, and then cooled and solidified on a casting roll having a surface temperature of 55 ° C. to obtain an unstretched film. During this extrusion, no irritating odor derived from isocyanate gas was felt.
This unstretched film was preheated by bringing it into contact with a preheated roll having a roll temperature of 90 to 120 ° C., and stretched 3.2 times in the machine direction at 130 ° C. Thereafter, the obtained uniaxially stretched film is guided to a stenter, preheated by passing through a preheating zone of 100 to 130 ° C., stretched 3.4 times in the transverse direction at 140 ° C., and further at 235 ° C. for 15 seconds. Then, the film was heat set at 180 ° C. and then subjected to a 3% relaxation treatment in the transverse direction at 180 ° C. to obtain a biaxially stretched film having a thickness of 38 μm.
The evaluation results of the biaxially stretched film obtained in Example 3 were as follows.
Isocyanate gas generation test: Isocyanate was not detected.
Breaking strength (before treatment): MD: 235 MPa, TD: 245 MPa
Breaking strength (after treatment): MD: 225 MPa, TD: 230 MPa
Hydrolysis stability (breaking strength retention): MD: 96%, TD: 94%

[Example 4]
Same as Example 3 except that pellets of polyethylene naphthalate (carboxyl terminal concentration 5 eq / ton) obtained in Reference Example 8 were used and the longitudinal draw ratio was 3.4 times and the transverse draw ratio was 3.6 times. A biaxially stretched film having a thickness of 38 μm was obtained.
The evaluation results of the biaxially stretched film obtained in Example 4 were as follows.
Isocyanate gas generation test: Isocyanate was not detected.
Breaking strength (before treatment): MD: 255 MPa, TD: 270 MPa
Breaking strength (after treatment): MD: 240 MPa, TD: 260 MPa
Hydrolysis resistance (breaking strength retention): MD: 94%, TD: 96%

[Comparative Example 1]
Obtained by kneading the PET resin produced in Reference Example 1 with a commercially available linear polycarbodiimide compound (“Carbodilite” LA-1 manufactured by Nisshinbo Chemical Co., Ltd.) at 290 ° C. using a twin screw extruder. The pellets (carboxyl terminal concentration 7 eq / ton) were made into a biaxially stretched film having a thickness of about 38 μm in the same manner as in Example 1. In Comparative Example 1, there was an irritating odor derived from isocyanate during film formation.
The evaluation results of the biaxially stretched film obtained in Comparative Example 1 were as follows.
Isocyanate gas generation test: 39 ppm of isocyanate gas was detected.
Breaking strength (before treatment): MD: 220 MPa, TD: 230 MPa
Breaking strength (after treatment): MD: 155 MPa, TD: 170 MPa
Hydrolysis stability (breaking strength retention): MD: 70%, TD: 74%

[Comparative Example 2]
Obtained by kneading a commercially available linear polycarbodiimide compound (“Carbodilite” LA-1 manufactured by Nisshinbo Chemical Co., Ltd.) 1 wt% at 290 ° C. using a twin-screw extruder with the PEN resin produced in Reference Example 2. The pellets (carboxyl terminal concentration 7 eq / ton) were made into a biaxially stretched film having a thickness of about 38 μm in the same manner as in Example 3. In Comparative Example 2, there was an irritating odor derived from isocyanate during the film forming process.
The evaluation results of the biaxially stretched film obtained in Comparative Example 2 were as follows.
Isocyanate gas generation test: 12 ppm of isocyanate gas was detected.
Breaking strength (before treatment): MD: 235 MPa, TD: 245 MPa
Breaking strength (after treatment): MD: 217 MPa, TD: 228 MPa
Hydrolytic stability (breaking strength retention): MD: 92%, TD: 93%

Claims (16)

  A composition comprising a compound containing at least a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded to each other by a bonding group and a polymer compound mainly composed of an aromatic polyester. A biaxially stretched film having a breaking strength in the longitudinal and transverse directions of 140 MPa or more.   The biaxially stretched film according to claim 1, wherein the number of atoms forming the cyclic structure is 8 to 50. The biaxially stretched film 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 biaxially stretched film 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 biaxially stretched film according to claim 1, wherein the compound containing a cyclic structure is represented by the following formula (2).

(In the formula, Qa 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.) The biaxially stretched film according to claim 5, wherein Qa is 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 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 biaxially stretched film 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 biaxially oriented film according to claim 7, wherein a trivalent bonding 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 biaxially stretched film according to claim 7, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer. The biaxially stretched film 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.) Q _c is represented by the following formula (4-1), (4-2) or biaxially oriented film of claim 10 wherein the tetravalent linking group represented by (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 biaxially stretched 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 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, and butylene naphthalene dicarboxylate as a main repeating unit. Biaxially stretched film. The biaxially stretched film 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) a polymer compound mainly composed of an aromatic polyester,
(C) a polymer mainly composed of 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 linking group. Compound. The biaxially stretched film 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) a polymer mainly composed of 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 linking group. Compound. The biaxially stretched film according to claim 1, wherein the composition comprises the following one component.
(C) a polymer mainly composed of 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 linking group. Compound.