JP2012001617A - Aliphatic polyester film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aliphatic polyester film suitable for an optical film such as a touch panel, wherein hydrolysis resistance is improved, intensity is prevented from degrading after the ultraviolet ray emission, and yellowing is prevented from occurring, without deteriorating work environment.SOLUTION: The aliphatic polyester film comprises: an aliphatic polyester resin; an ultraviolet absorber having maximum absorption wavelength of 260-320 nm; and at least a cyclic structure that has one carbodiimide group. In the cyclic structure, a first nitride and second nitride in the carbodiimide group are bonded through a linking group.

Description

  The present invention relates to an aliphatic polyester film.

  Polyester films such as polyethylene terephthalate have recently been widely used for optical films. For example, brightness enhancement sheets (commonly referred to as “prism lens sheets”) used in liquid crystal display devices, touch panels, backlights, and antireflection coatings. It is used as a base film for films, electromagnetic shielding films used for plasma displays, organic EL displays, explosion-proof films used for various displays, and the like.

  In recent years, with the rapid spread of car navigation systems, PDAs, and the like, touch panels that allow input by simply touching a display screen with a finger or pressing with a pen have become widespread. As a touch panel system, there are a resistive film system, a capacitance system, an ultrasonic system, an infrared system, and the like, but the resistive film system is most often used because of cost and ease of maintenance. The resistive touch panel generally has a structure in which a transparent conductive layer is formed on glass or a film, and conductive layers formed on the film are arranged to face each other via a spacer. Briefly, the structure is display / glass or film / transparent conductive layer A / spacer / transparent conductive layer B / film / hard coat layer. If it is pressed directly from the hard coat side with a finger or a pen, the film is curved only at that portion, and the transparent conductive layer B on the hard coat side is brought into contact with the transparent conductive layer A facing the input, and the pressing position is X−. It is recognized as the Y coordinate and input to the computer.

  On the other hand, in recent years, biodegradable polymers that are decomposed in a natural environment have attracted attention from the viewpoint of global environmental conservation, and various biodegradable polymers have been developed. Among them, polylactic acid has good transparency, can be melt-molded, can be produced economically by fermentation using biomass as a raw material, and is expected to be used as an optical material.

  However, aliphatic polyesters such as polylactic acid are known to be prone to hydrolysis when used in a hot and humid atmosphere. When used in such an environment, some means is used. It is necessary to improve hydrolysis resistance. Then, adding a carbodiimide compound is proposed as a technique for improving the hydrolysis resistance of aliphatic polyester (patent document 1).

  However, the carbodiimide compound used in this proposal is a linear carbodiimide compound. When such a linear carbodiimide compound is used as a terminal blocker of a polymer compound, the carbodiimide compound is attached to the terminal of the polymer compound. A compound having an isocyanate group is liberated along with the bonding reaction, generating a unique odor of the isocyanate compound and deteriorating the working environment.

  In general, a base film of an optical film used for a touch panel or the like may be laminated with a functional layer such as a hard coat by curing an ultraviolet curable resin. Since the group polyester is extremely sensitive to ultraviolet rays, for example, when a hard coat is laminated by ultraviolet curing, there is a problem that the strength is remarkably lowered thereafter, and the film is liable to be cracked. And even if it adds a normal ultraviolet absorber in order to avoid this problem, there exists a problem that yellowing by ultraviolet irradiation cannot be suppressed.

JP 2003-003052 A JP 2006-227090 A

Chemical Review, No. 39, 1998 (published by Academic Publishing Center)

  The object of the present invention is to solve the problems of the prior art described above, improve the hydrolysis resistance without deteriorating the working environment, and simultaneously suppress the decrease in strength and yellowing after UV irradiation. An object of the present invention is to provide an aliphatic polyester film suitable for an optical film such as a touch panel.

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. Aliphatic polyester resin (component A), ultraviolet absorber (component B) having a maximum absorption wavelength at a wavelength of 260 to 320 nm, and one carbodiimide group, the first nitrogen and the second nitrogen are bonded by a bonding group An aliphatic polyester film containing a compound (C component) containing at least a cyclic structure.
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記載の脂肪族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．Ｃ成分が、下記式（２）で表される上記１記載の脂肪族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記載の脂肪族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．Ｃ成分が、下記式（３）で表される上記１記載の脂肪族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記載の脂肪族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記載の脂肪族ポリエステルフィルム。
１０．Ｃ成分が、下記式（４）で表される上記１記載の脂肪族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記載の脂肪族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記載の脂肪族ポリエステルフィルム。
１３．Ａ成分が、ポリ乳酸系樹脂を含む、上記１〜１２のいずれか１に記載の脂肪族ポリエステルフィルム。
１４．ポリ乳酸系樹脂が、ステレオコンプレックス結晶を形成している、上記１３記載の脂肪族ポリエステルフィルム。
１５．紫外線吸収剤（Ｂ成分）の含有量が、フィルムの重量に対して０．００１〜５重量％であることを特徴とする上記１〜１４のいずれか１に記載の脂肪族ポリエステルフィルム。
１６．紫外線吸収剤（Ｂ成分）がヒドロキシベンゾフェノン類またはトリアジン類であることを特徴とする上記１〜１５のいずれか１に記載の脂肪族ポリエステルフィルム。 The present invention also includes the following.
2. 2. The aliphatic polyester film as described in 1 above, wherein the C component has 8 to 50 atoms forming a cyclic structure.
3. 2. The aliphatic polyester film as described in 1 above, wherein the cyclic structure in component C 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 aliphatic polyester film as described in 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). The aliphatic polyester film as described in 1 above, wherein the component C 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). 6. The aliphatic polyester film as described in 5 above, wherein Q _a 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. ^{Ar 1, Ar 2, R 1} , R 2, X 1, is the same as ^{X 2,} X ^3, s and k in.)
7). The aliphatic polyester film as described in 1 above, wherein the component C 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 aliphatic polyester film of claim 7 wherein the 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.)
9. 8. The aliphatic polyester film as described in 7 above, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer.
10. The aliphatic polyester film as described in 1 above, wherein the component C 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 aliphatic 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 aliphatic polyester film 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 aliphatic polyester film according to any one of 1 to 12 above, wherein the component A contains a polylactic acid resin.
14 14. The aliphatic polyester film as described in 13 above, wherein the polylactic acid resin forms a stereocomplex crystal.
15. 15. The aliphatic polyester film as described in any one of 1 to 14 above, wherein the content of the ultraviolet absorber (component B) is 0.001 to 5% by weight based on the weight of the film.
16. The aliphatic polyester film as described in any one of 1 to 15 above, wherein the ultraviolet absorber (component B) is a hydroxybenzophenone or a triazine.

  According to the present invention, an aliphatic polyester film suitable for an optical film such as a touch panel, which does not deteriorate the working environment, is improved in hydrolysis resistance, and is simultaneously suppressed in strength reduction and yellowing after ultraviolet irradiation. Can be provided. Thereby, the strength fall and yellowing after providing a hard coat etc. by ultraviolet curing can be suppressed.

Hereinafter, the present invention will be described in detail.
<Cyclic carbodiimide compound (component C)>
First, a compound (C component) that is a characteristic component in the present invention and includes 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 will be described. The C component has a cyclic structure (hereinafter, the C component may be abbreviated as a cyclic carbodiimide compound). The cyclic carbodiimide compound may have a plurality of cyclic structures.

  Here, 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>
In the present invention, the production method of the cyclic carbodiimide compound 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 combining the method described in the following literature, or changing or combining suitably according to the target compound.

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.A. Richter et al.
Journal of Organic Chemistry, Vol. 59, no. 24, 7306-7315, 1994.
A New and Efficient Preparation of Cyclic Carboxidimids from Bis (iminophosphoranea) and the System Boc2O / 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。Ｅ１およびＥ２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。Ａｒａ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. E1 and E2 are each independently a halogen atom, A group selected from the group consisting of a toluenesulfonyloxy group, a methanesulfonyloxy group, a benzenesulfonyloxy group, and a p-bromobenzenesulfonyloxy group, Ara is a phenyl group, and X is the following formula (i-1): To (i-3).)

  In addition, the cyclic carbodiimide compound can effectively seal the acidic group of the polymer compound. However, as long as it does not contradict the gist of the present invention, for example, a conventionally known polymer carboxyl group sealing agent 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.

<Aliphatic polyester resin (component A)>
In the present invention, the aliphatic polyester-based resin (component A) is mainly composed of a polymer mainly composed of an aliphatic hydroxycarboxylic acid, an aliphatic polycarboxylic acid or an ester-forming derivative thereof, and an aliphatic polyhydric alcohol. Examples thereof include polymers formed by polycondensation as a component and copolymers thereof.

  Examples of the polymer having aliphatic hydroxycarboxylic acid as a main constituent component include polycondensates such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and copolymers. Among them, preferred are polyglycolic acid, polylactic acid, poly-3-hydroxycarboxylic butyric acid, poly-4-polyhydroxybutyric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, and copolymers thereof. Lactic acid is preferred, and poly L-lactic acid, poly D-lactic acid, and stereocomplex polylactic acid and racemic polylactic acid forming a stereocomplex crystal are suitably used.

  As polylactic acid, what has L-lactic acid and / or D-lactic acid as the main repeating unit may be used (here, the main means that the component occupies 50% or more of the whole). ).

  Poly L monolactic acid and poly D-lactic acid can be produced by a conventionally known method. For example, L- or D-lactide can be heated in the presence of a metal-containing catalyst and produced by ring-opening polymerization. Moreover, after crystallizing a low molecular weight polylactic acid containing a metal-containing catalyst, it is produced by heating, solid phase polymerization under reduced pressure or increased pressure, in the presence or absence of an inert gas stream. You can also. Further, it can be produced by a direct polymerization method in which lactic acid is subjected to dehydration condensation in the presence / absence of an organic solvent.

  The polymerization reaction can be carried out in a conventionally known reaction vessel. For example, a vertical reactor or a horizontal reactor having a high-viscosity stirring blade such as a helical ribbon blade can be used alone or in parallel. . Moreover, any of a batch type, a continuous type, a semibatch type may be sufficient, and these may be combined.

  Alcohol may be used as a polymerization initiator. Such alcohol is preferably non-volatile without inhibiting the polymerization of polylactic acid. For example, decanol, dodecanol, tetradecanol, hexadecanol, octadecanol and the like can be suitably used.

  In the solid phase polymerization method, polylactic acid having a relatively low molecular weight (about 15 to 200) obtained by the above-described ring-opening polymerization method or direct polymerization method of lactic acid is used as a prepolymer. The prepolymer is preferably crystallized in advance in the temperature range of the glass transition temperature or higher and lower than the melting point from the viewpoint of preventing resin pellet fusion. The crystallized prepolymer is filled in a fixed vertical or horizontal reaction vessel, or a reaction vessel (such as a rotary kiln) in which the vessel itself rotates, such as a tumbler or kiln. Heated to a temperature range. There is no problem even if the polymerization temperature is increased in stages as the polymerization proceeds. In addition, for the purpose of efficiently removing water generated during solid phase polymerization, a method of reducing the pressure inside the reaction vessels or circulating a heated inert gas stream is also preferably used.

It is preferable to inactivate the metal-containing catalyst used during the polymerization of polylactic acid with a conventionally known deactivator prior to use, because the stability of polylactic acid and the resin composition to heat and moisture can be improved.
Examples of such a deactivator include an organic ligand having a group of chelate ligands having an imino group and capable of coordinating with a polymerized metal catalyst.

  Also, dihydridooxoline (I) acid, dihydridotetraoxodiphosphorus (II, II) acid, hydridotrioxoline (III) acid, dihydridopentaoxodiphosphoric acid (III), hydridopentaoxodi (II, IV) Acid, dodecaoxohexaphosphoric acid (III), hydridooctaoxotriphosphoric acid (III, IV, IV) acid, octaoxotriphosphoric acid (IV, III, IV) acid, hydridohexaoxodiphosphoric acid (III, V) acid, hexaoxodiacid Low oxidation number phosphoric acid having an acid number of 5 or less, such as phosphoric acid (IV), decaoxotetraphosphoric acid (IV), hedecaoxotetraphosphoric acid (IV), and eneoxooxophosphoric acid (V, IV, IV). .

Further, orthophosphoric acid represented by the formula xH ₂ O · yP ₂ O ₅ , x / y = 3, 2> x / y> 1, and diphosphoric acid, triphosphoric acid, tetraphosphoric acid, five Examples thereof include polyphosphoric acid called phosphoric acid and a mixture thereof.

  Further, metaphosphoric acid represented by x / y = 1, in particular, trimetaphosphoric acid, tetrametaphosphoric acid, 1> x / y> 0, and ultralin having a network structure in which a part of the phosphorus pentoxide structure is left. Acid (these may be collectively referred to as metaphosphoric acid compounds).

  Moreover, acidic salts of these acids, monovalent and polyhydric alcohols, partial esters of polyalkylene glycols, complete esters, phosphono-substituted lower aliphatic carboxylic acid derivatives and the like can be mentioned.

  Metaphosphoric acid compounds include cyclic metaphosphoric acid condensed with about 3 to 200 phosphoric acid units, ultra-regional metaphosphoric acid having a three-dimensional network structure, or their (alkal metal salt, alkaline earth metal salt, onium salt). Include. Of these, cyclic sodium metaphosphate, ultra-region sodium metaphosphate, phosphono-substituted lower aliphatic carboxylic acid derivative dihexylphosphonoethyl acetate (hereinafter sometimes abbreviated as DHPA) and the like are preferably used.

  The polylactic acid in the present invention preferably has a melting point of 150 ° C. or higher. When the melting point is lower than 150 ° C., the dimensional stability, high temperature mechanical properties, etc. of the film cannot be improved.

More preferably, the melting point of polylactic acid is 170 ° C. or higher, more preferably 200 ° C. or higher. Here, the melting point means the peak temperature of the melting peak obtained by DSC measurement. In particular, in order to impart heat resistance, it is preferable that polylactic acid forms a stereocomplex phase crystal. By setting it as such an aspect, it is excellent in thermal dimensional stability.
Here, the stereocomplex polylactic acid is a eutectic formed by a poly L-lactic acid segment and a poly D-lactic acid segment.

Stereocomplex phase crystals usually have a higher melting point than homophase crystals formed solely by poly-L-lactic acid or poly-D-lactic acid. This is remarkably exhibited when the amount of stereocomplex phase crystals is large relative to the total amount of crystals. The stereocomplex crystallinity (S) according to the following formula is preferably 95% or more, and more preferably 100%.
S (%) = [ΔHms / (ΔHmh + ΔHms)] × 100
(However, ΔHms is the melting enthalpy of stereocomplex phase crystals, and ΔHmh is the melting enthalpy of homophase polylactic acid crystals.)

In order to stably and highly advance the formation of stereocomplex polylactic acid crystals, a method of blending specific additives is preferably applied.
That is, for example, a technique of adding a metal phosphate metal salt represented by the following formula as a stereocomplex crystallization accelerator can be mentioned.

In the formula, R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ¹² and R ¹³ each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M ₁ represents Represents an alkali metal atom, an alkaline earth metal atom, a zinc atom or an aluminum atom, p represents 1 or 2, q represents 0 when M ₁ is an alkali metal atom, an alkaline earth metal atom or a zinc atom; When it is an atom, it represents 1 or 2.

In the formula, each of R ¹⁴ , R ¹⁵ and R ¹⁶ independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M ₂ represents an alkali metal atom, an alkaline earth metal atom, a zinc atom or an aluminum atom. P represents 1 or 2, q represents 0 when M ₂ is an alkali metal atom, alkaline earth metal atom or zinc atom, and 1 or 2 when M ₂ is an aluminum atom.

M ₁ and M ₂ of the metal phosphate represented by the above two formulas are preferably Na, K, Al, Mg, Ca and Li, and in particular, Li, Al is the most among K, Na, Al and Li. It can be used suitably.
As these metal phosphates, trade names manufactured by ADEKA Corporation, “ADEKA STAB” NA-11, NA-71 and the like are exemplified as suitable agents.

  The metal phosphate is used in an amount of 0.001 to 2 wt%, preferably 0.005 to 1 wt%, more preferably 0.01 to 0.5 wt%, still more preferably 0.02 to 0.3 wt% with respect to polylactic acid. It is preferable. When the amount is too small, the effect of improving the stereocomplex crystallinity (S) is small, and when too large, the stereocomplex crystal melting point is lowered, which is not preferable.

Further, if desired, a known crystallization nucleating agent can be used in combination to enhance the action of the metal phosphate. Of these, calcium silicate, talc, kaolinite, and montmorillonite are preferably selected.
The amount of the crystallization nucleating agent used is selected in the range of 0.05 to 5 wt%, more preferably 0.06 to 2 wt%, and still more preferably 0.06 to 1 wt% with respect to polylactic acid.

  Polylactic acid may be obtained by any manufacturing method. For example, a polylactic acid production method includes a two-stage lactide method in which L-lactic acid and / or D-lactic acid is used as a raw material to form lactide, which is a cyclic dimer, and then ring-opening polymerization is performed. In addition, it can be suitably obtained by a generally known polymerization method such as a one-step direct polymerization method in which dehydration condensation is directly performed in a solvent using D-lactic acid as a raw material.

  In the production of polylactic acid, carboxylic acid groups may be contained, but the smaller the amount of carboxylic acid groups contained, the better. For these reasons, it is preferable to use, for example, ring-opened polymerization from lactide using an initiator other than water, or a polymer that has been chemically treated after polymerization to reduce carboxylic acid groups.

  The weight average molecular weight of polylactic acid is usually at least 50,000, preferably at least 100,000, preferably 100,000 to 300,000. When the average molecular weight is lower than 50,000, the strength properties of the film are lowered, which is not preferable. If it exceeds 300,000, the melt viscosity becomes too high and melt film formation may be difficult.

  The polylactic acid in the present invention may be a copolymerized polylactic acid obtained by copolymerizing other components having ester forming ability in addition to L-lactic acid and D-lactic acid. The copolymerizable component includes glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, hydroxycarboxylic acids such as 6-hydroxycaproic acid, ethylene glycol, propylene glycol, butanediol, neo Compounds containing a plurality of hydroxyl groups in the molecule such as pentyl glycol, polyethylene glycol, glycerin and pentaerythritol or derivatives thereof, compounds containing a plurality of carboxylic acid groups in the molecule such as adipic acid, sebacic acid and fumaric acid Or derivatives thereof. However, in order to maintain a high melting point and not to impair film strength, it is desirable that 70 mol% or more of the aliphatic polyester resin (component A) constituting the film is composed of lactic acid units.

<Ultraviolet absorber (component B)>
The aliphatic polyester film of the present invention needs to contain an ultraviolet absorber (component B) having a maximum absorption wavelength at a wavelength of 260 to 320 nm. As a result, a decrease in intensity and yellowing after ultraviolet irradiation can be suppressed at the same time. From such a viewpoint, the ultraviolet absorber (component B) preferably has a maximum absorption wavelength at a wavelength of 270 to 300 nm. In general, ultraviolet absorbers often have absorption at a wavelength of 340 to 380 nm. However, such ultraviolet absorbers cannot simultaneously suppress deterioration in strength and yellowing of the aliphatic polyester of the present invention.

  In the present invention, an ultraviolet absorber having absorption at 340 to 380 nm while having absorption at a wavelength of 260 to 320 nm can be used. Furthermore, an ultraviolet absorber having an absorption wavelength at a wavelength of 260 to 320 nm and a general ultraviolet absorber having an absorption at 340 to 380 nm may be used in combination.

  The content of the ultraviolet absorber (component B) affects the ultraviolet resistance and transparency of the aliphatic polyester film. If the content of the ultraviolet absorber is too large, the transparency of the aliphatic polyester film may be lowered, which is not preferable. On the other hand, if the amount is too small, the effect of UV resistance is not sufficiently observed, and the effect of suppressing strength reduction or yellowing tends to decrease. From this viewpoint, the content of the ultraviolet absorber is preferably 0.001 to 5% by weight, more preferably 0.01 to 2% by weight, based on the weight of the film.

  Examples of the ultraviolet absorber used in the present invention include salicylic acid derivatives such as phenyl salicylate and p-tert-butylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy- 4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2 ′ , 4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, benzophenones such as bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2- (2'-hydroxy-5 ' -Methylphenyl) ben Triazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5 Chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole 2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydro Phthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl)- Benzotriazoles such as-(2H-benzotriazol-2-yl) phenol], oxalic acid anilide derivatives known by trade names such as Sanduvor EPU and Sanduvor VSU, 2-ethoxy-5-tert-butyl-2'-ethylsuccinic acid bisanilide, 2 -Ethoxy-2-ethylsuccinic acid bisanilide, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, 1,3-bis- (4-benzoyl-3-hydroxyphenoxy) -2-propyl acrylate, 1,3-bis- (4-benzoyl-3-hydroxyphenoxy) -2-propyl methacrylate, 2-hydroxy-4- Methoxybenzophenone-5-sulfonic acid, o Methyl luso-benzoylbenzoate, ethyl-2-cyano-3,3-diphenyl acrylate, 2-hydroxy-4-benzyloxybenzophenone, nickel dibutyldithiocarbamate, nickel / chitobisphenol complex, nickel-containing organic light stabilizer, barium , Sodium and phosphorus-containing organic / inorganic composites, semicarbazone light stabilizers, zinc oxide ultraviolet light stabilizers and synergists known under the trade name Sanshade, etc., bis (2,2,6,6-tetramethyl-4 -Piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- {3- (3,5-di-tert-4-hydroxy-phenyl) propionyloxy } Ethyl] -4- {3- (3,5-di-tert-butyl-4-hydroxyphene L) propionyloxy} -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,2,3-triazaspiro [4,5] undecane -2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetrasuccinate Methylpiperidine polycondensate, poly [6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetra Methyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-tert-butyl-4-hydroxybenzyl)- 2-n-bu Lumaronic acid bis (1,2,2,6,6-pentamethyl-4-piperidyl), tetraxy (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate 1, 2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and tridecyl alcohol condensate, 1,2,3,4-butanetetracarboxylic acid , 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4 A condensate of piperidinol with β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,3 , 4-Butanetetra Rubonic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5 5] Undecane) Condensates with diethanol, hindered amines such as 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate and the like. Among them, hydroxybenzophenones such as Ubinur 3050 and 3049, and triazines such as Tinuvin 1577F and Adeka Stab LA-46 are particularly preferable from the viewpoint of maintaining strength and coloring after ultraviolet irradiation.

<Resin composition>
The resin composition for forming the aliphatic polyester film of the present invention comprises an aliphatic polyester resin (component A), an ultraviolet absorber (component B), and a cyclic carbodiimide compound (component C) as constituent components.

  In the present invention, it is preferable to use polylactic acid in which a stereocomplex phase crystal is formed as the aliphatic polyester-based resin (component A), and such a resin composition has the above-described stereocomplex crystallinity (S) in DSC measurement. ) Is preferably 80% or more. When the stereocomplex crystallinity is 80% or more, the thermal shrinkage rate at 90 ° C. of the film obtained therefrom can be reduced. The stereocomplex crystallinity of the resin composition is more preferably 90% or more, still more preferably 95% or more, and particularly preferably the stereocomplex crystallinity is 100%.

  In this invention, it is preferable that the content rate of the cyclic carbodiimide compound (C component) in a resin composition is 0.001 to 5 weight% on the basis of the weight of an aliphatic polyester-type resin (A component). If the amount of component C is within this range, the moisture stability and hydrolysis resistance of the resin composition and the film obtained therefrom can be suitably increased. From this viewpoint, the content ratio of the cyclic carbodiimide compound (C component) is more preferably 0.01 to 5% by weight, and still more preferably 0.1 to 4% by weight. If the amount is less than this range, the effect of the cyclic carbodiimide compound (component C) may not be recognized effectively, and even if it is applied in a large amount beyond this range, the hydrolysis stability will be further improved. Not expected.

  When the aliphatic polyester resin (component A) contains polylactic acid, the lactide content is preferably 0 to 1000 ppm, more preferably 0, based on the weight of the aliphatic polyester resin (component A). It is -200 ppm, More preferably, it is the range of 0-100 ppm. A lower lactide content is preferable from the viewpoint of physical properties such as hue and stability of the resin composition, but even if an excessive reduction operation is applied, further improvement in physical properties is not expected and it is not preferable from the viewpoint of cost. A case occurs.

  The carboxyl group concentration of the resin composition is preferably 0 to 30 equivalents / ton, more preferably 0 to 10 equivalents / ton, more preferably 0, based on the weight of the aliphatic polyester resin (component A). It is in the range of ˜5 equivalent / ton, particularly preferably in the range of 0 to 1 equivalent / ton. Reduction of the carboxyl group concentration can be easily achieved by using a cyclic carbodiimide compound (C component).

<Other ingredients>
[Other resin components]
In the present invention, the resin composition contains other resin components other than the aliphatic polyester resin (component A), the ultraviolet absorber (component B), and the cyclic carbodiimide compound (component C), and the object of the present invention is impaired. It can contain in the range which is not.

Specific examples of other resin components include acrylic resins, polyolefins such as polyethylene and polypropylene, styrene resins such as polystyrene and styrene acrylonitrile copolymers, polyamides, polyphenylene sulfide resins, polyether ether ketone resins, polyesters, polysulfones, Examples thereof include thermoplastic resins such as polyphenylene oxide, polyimide, polyetherimide, and polyacetal, and thermosetting resins such as phenol resin, melamine resin, silicone resin, and epoxy resin. These can contain 1 or more types.
In particular, it is preferable to add an acrylic resin from the viewpoint of maintaining transparency.

  Such acrylic resins include methacrylic acid esters such as cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, and methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isopropyl acrylate, and 2-ethylhexyl acrylate. One or more monomers selected from acrylic esters are polymerized. These monomers can be used alone or in admixture of two or more. Of these, a homopolymer of methyl methacrylate or a copolymer with other monomers is preferable.

  Examples of monomers copolymerizable with methyl methacrylate include other alkyl methallylic esters, alkyl acrylates, aromatic vinyl compounds such as styrene, vinyl toluene and α-methyl styrene, acrylonitrile, methacrylonitrile, etc. Vinyl cyanides, maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide, unsaturated carboxylic acid anhydrides such as maleic anhydride, and unsaturated acids such as acrylic acid, methacrylic acid and maleic acid It is done. Among these monomers copolymerizable with methyl methacrylate, acrylic acid alkyl esters are particularly excellent in heat decomposition resistance. A methacrylic resin obtained by copolymerizing alkyl acrylates is preferable because of its high fluidity during molding.

  The amount of alkyl acrylates used when methyl acrylate is copolymerized with methyl methacrylate is preferably 0.1% by weight or more from the viewpoint of thermal decomposition resistance, and 15% from the viewpoint of heat resistance. % Or less is preferable. The content is more preferably 0.2% by weight or more and 14% by weight or less, and particularly preferably 1% by weight or more and 12% by weight or less.

  Among these alkyl acrylates, methyl acrylate and ethyl acrylate are particularly most preferable in terms of the above improvement effect even when they are copolymerized with a small amount of methyl methacrylate. The said monomer which can be copolymerized with methyl methacrylate can also be used 1 type or in combination of 2 or more types.

  The weight average molecular weight of the acrylic resin is preferably 50,000 to 200,000. The weight average molecular weight is preferably 50,000 or more from the viewpoint of the strength of the molded product, and preferably 200,000 or less from the viewpoint of molding processability and fluidity. A more preferable range is 70,000-150,000. In the present invention, isotactic polymethacrylate and syndiotactic polymethacrylate can be used simultaneously.

  As a method for producing an acrylic resin, for example, generally used polymerization methods such as cast polymerization, bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization, and anionic polymerization can be used. From this viewpoint, bulk polymerization or solution polymerization without using a suspending agent or an emulsifier is desirable. When solution polymerization is performed, a solution prepared by dissolving a mixture of monomers in an aromatic hydrocarbon solvent such as toluene, ethylbenzene, or xylene can be used. In the case of polymerization by bulk polymerization, the polymerization can be started by irradiation with free radicals generated by heating or ionizing radiation as is usually done.

  As the initiator used in the polymerization reaction, any initiator generally used in radical polymerization can be used. For example, an azo compound such as azobisisobutylnitrile, benzoyl peroxide, lauroyl peroxide, t-butylperoxy An organic peroxide such as -2-ethylhexanoate is used. In particular, when the polymerization is carried out at a high temperature of 90 ° C. or higher, solution polymerization is common, so that the peroxide has a 10-hour half-life temperature of 80 ° C. or higher and is soluble in the organic solvent used, An azobis initiator or the like is preferable. Specifically, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 1,1 -Azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isoptyronitrile, etc. can be mentioned. These initiators are used in the range of 0.005 to 5% by weight.

  As the molecular weight regulator used as necessary for the polymerization reaction, any one used in general radical polymerization is used. For example, mercaptan compounds such as butyl mercaptan, octyl mercaptan, dodecyl mercaptan, 2-ethylhexyl thioglycolate are particularly preferable. These molecular weight regulators are added in a concentration range such that the degree of polymerization is controlled within the above range.

  In the present invention, when an acrylic resin is added to an aliphatic polyester-based resin (component A), the ratio of the aliphatic polyester-based resin (component A) to the acrylic resin is a specific A component or B component. And the properties of the film to be obtained (optical properties, mechanical properties) may be set as appropriate. Usually, the weight ratio (component A / component B) is (99/1) to (1/99). May be set, preferably (99/1) to (50/50), more preferably (80/20) to (50/50), still more preferably (70/30) to (50/50). ).

[Additive]
Furthermore, arbitrary additives can be mix | blended with the resin composition of this invention according to various objectives within the range which does not impair the effect of this invention remarkably. The type of additive is not particularly limited as long as it is generally used for blending resins and rubber-like polymers.

Examples of the additive include inorganic fillers and pigments such as iron oxide. Also, lubricants such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, ethylene bisstearamide, mold release agent, paraffinic process oil, naphthenic process oil, aromatic process oil, paraffin, Examples include organic polysiloxanes, softeners and plasticizers such as mineral oil, hindered phenol antioxidants, antioxidants such as phosphorus heat stabilizers, and antistatic agents.
Further, reinforcing agents such as organic fibers, glass fibers, carbon fibers, and metal whiskers, coloring agents, and electrostatic adhesion improving agents can be used. Moreover, said mixture is mentioned.

  The resin composition in the present invention can be produced by a known method. For example, using a melt kneader such as a single screw extruder, twin screw extruder, Banbury mixer, Brabender, various kneaders, etc., aliphatic polyester resin (component A), ultraviolet absorber (component B) and cyclic carbodiimide compound ( Component C) and, if necessary, other components such as the acrylic resin can be added and melt-kneaded to produce a resin composition.

<Characteristics of film>
[Stereo Complex Crystallinity: S]
The aliphatic polyester film of the present invention preferably has a crystal melting peak of stereocomplex phase polylactic acid of 190 ° C. or higher in DSC measurement, and further, stereocomplex crystallization defined by the following formula from the crystal melting peak intensity of DSC measurement The degree (S) is preferably 80% or more, more preferably 90 to 100%, still more preferably 97 to 100%, and particularly preferably 100%. By being such an aspect, the thermal dimensional stability of the film is improved.

That is, the film of the present invention preferably has a highly formed stereocomplex phase of polylactic acid.
S (%) = [ΔHms / (ΔHmh + ΔHms)] × 100
ΔHms represents the crystal melting enthalpy (J / g) of the stereocomplex phase polylactic acid. ΔHmh represents the crystal melting enthalpy (J / g) of homophase polylactic acid.
The stereocomplex crystallinity (S) is a parameter indicating the ratio of stereocomplex polylactic acid crystals that are finally produced in the heat treatment process.

  In the present invention, the crystal melting peak appearing at 190 ° C. or higher in DSC measurement is a crystal melting peak attributed to melting of the stereocomplex phase polylactic acid, and the crystal melting peak appearing below 190 ° C. is the melting phase of homophase polylactic acid. Is a crystal melting peak attributed to.

[Heat shrinkage]
The aliphatic polyester film in the present invention has a thermal shrinkage of 0. 0 in the longitudinal direction (the direction of the film-forming machine axis, sometimes referred to as the longitudinal direction or MD) when heat-treated at 90 ° C for 30 minutes. It is preferable that it is 0 to 1.5% of range. By setting it as such an aspect, the deterioration of the planarity at the time of processing, such as a hard coat, and curl generation can be suppressed. If the heat shrinkage in the vertical direction exceeds 1.5%, flatness is deteriorated during processing of a hard coat or the like. On the other hand, if the thermal contraction rate is less than 0.0% and minus, curling may occur during hard coat lamination due to thermal expansion.

In addition, the aliphatic polyester film in the present invention is in the transverse direction when heat-treated at 90 ° C. for 30 minutes (the direction perpendicular to the film-forming machine axis direction; hereinafter sometimes referred to as the width direction or TD). The heat shrinkage rate is preferably 1.0 to -0.5%, more preferably 0.5 to -0.3%. By setting it as such an aspect, the deterioration of the planarity at the time of processing, such as a hard coat, and curl generation can be suppressed. When the thermal shrinkage rate in the lateral direction exceeds 1.0%, flatness is deteriorated during processing of a hard coat or the like. On the other hand, if it is less than -0.5%, curling may occur during hard coat lamination due to thermal expansion.
Furthermore, from the viewpoint of curling prevention when laminating hard coats, the difference in thermal shrinkage between the vertical direction and the horizontal direction is preferably within 0.5%.

  Such thermal shrinkage can be achieved by appropriately adjusting stretching conditions, heat treatment (heat setting) conditions, and relaxation heat treatment conditions in film formation. For example, the thermal contraction rate tends to decrease by decreasing the draw ratio, increasing the heat treatment temperature, or increasing the relaxation amount. In the present invention, when it is desired to simultaneously achieve the longitudinal and transverse heat shrinkage rates, a film having a desired longitudinal and transverse shrinkage rate can be obtained by combining longitudinal relaxation heat treatment and transverse relaxation heat treatment. .

[Film thickness]
The thickness of the aliphatic polyester film of the present invention is preferably 25 to 350 μm, more preferably 50 to 250 μm, in order to obtain the strength required when used as an optical substrate film for display.

[Haze]
The aliphatic polyester film of the present invention has a haze of 5.0% or less. When the haze is in the above numerical range, it means excellent transparency and can be suitably used for optical applications. From such a viewpoint, the haze is preferably 4.0% or less, more preferably 3.0% or less. Such haze can be achieved by appropriately adjusting the mode of the ultraviolet absorber (component B). For example, when the content is reduced, the haze tends to be lowered.

[Light transmittance]
The aliphatic polyester film of the present invention preferably has a light transmittance of 70% or more. When the light transmittance is less than 70%, the visibility tends to be inferior when used for optical applications such as a touch panel. The light transmittance is preferably 80% or more, more preferably 90% or more. Such light transmittance can be achieved by appropriately adjusting the mode of the ultraviolet absorber (component B). For example, when the content is reduced, the light transmittance tends to increase.

[Hydrolysis resistance]
The aliphatic polyester film of the present invention has a fracture strength retention of 50% or more after being subjected to wet heat treatment for 3000 hours in an environment of 85 ° C. and 85% RH. Such an aspect means that the hydrolysis resistance is excellent, and in optical applications, it can be used for a long time even in a humid heat environment, which is preferable.

<Film production method>
The aliphatic polyester film of the present invention is preferably a biaxially stretched film, can improve heat resistance and improve the effect of suppressing thermal deflection. Such biaxial stretching may be sequential biaxial or simultaneous biaxial.

  In the case of sequential biaxial stretching, the above resin composition is melt-extruded into a film shape, cooled and solidified with a casting drum to form an unstretched film, and this unstretched film is a crow transition temperature of the aliphatic polyester resin (component A). (Tg) to (Tg + 60) Longitudinal stretching is performed once or twice or more in the machine direction in the machine direction so that the total magnification is 3 to 6 times, and then the machine direction is 3 to 5 in the transverse direction at Tg to (Tg + 60) ° C. The film is stretched transversely to obtain a biaxially stretched film, and then further subjected to heat treatment at 140 to 200 ° C. for 1 to 60 seconds in a tenter as necessary, and further 10 to 20 ° C. lower than the heat treatment temperature. Can be obtained by performing relaxation heat treatment while shrinking in the vertical and horizontal directions by 0 to 20%. At this time, heat resistance can be improved by selecting stereocomplex polylactic acid as A component.

  In the case of simultaneous biaxial stretching, the above resin composition is melt-extruded into a film, cooled and solidified with a casting drum to form an unstretched film, and this unstretched film is stretched in the machine direction and width at Tg to (Tg + 60) ° C. Simultaneously biaxially stretched in the direction so that the area magnification is 6 to 25 times, preferably 10 to 20 times, and further heat-treated at 140 to 200 for 1 to 60 seconds as necessary. It can be obtained by performing a relaxation heat treatment at a temperature lower by 10 to 20 ° C. while shrinking 0 to 10% in the longitudinal direction and the transverse direction between the tenter and a pair of subsequent take-up rolls. In this method, since the film is less likely to come into contact with the roll, minute scratches and the like are less likely to occur on the film surface than in the method described above, which is advantageous for application to optical applications.

  In the above, the relaxation heat treatment is performed on the downstream side of the stretching zone of the tenter, by inserting blades in the vicinity of both ends of the film to separate the film from the clip gripping portion, and the speed of the take-up roll is set to 0 than the maximum speed of the clip in the tenter. This can be done by slowing down ~ 5%. Further, when a pantograph type or linear motor type tenter is used as the tenter, the clip interval can be reduced in the vertical direction.

<Coating layer>
In the case of laminating a hard coat layer or the like thereon, the aliphatic polyester film of the present invention is at least one selected from the group consisting of acrylic resin, polyester resin, and urethane resin on the above aliphatic polyester film. It is preferable to have a coating layer containing a polymer binder. By having such a coating layer, good adhesiveness can be obtained. The coating layer may be provided on one side of the aliphatic polyester film, may be provided on both sides, or preferably on both sides. As needed, you may use together an acrylic resin, a polyester resin, a urethane resin, and the modified body of these resins. Further, in order to ensure the winding property, fine particles or the like may be added to the coating layer within a range that does not impair the optical characteristics.

[Polymer binder]
(acrylic resin)
The acrylic resin of the coating layer in the present invention has a glass transition point (Tg) of preferably 20 to 80 ° C., more preferably 25 to 70 ° C., and can enhance the effect of improving adhesiveness. When the glass transition point is less than 20 ° C., the blocking property is unfavorably deteriorated. On the other hand, when it exceeds 80 ° C., the film forming property is deteriorated and the oligomer precipitation sealing property is unfavorably deteriorated. The acrylic resin is preferably soluble or dispersible in water.

  The acrylic resin can be obtained by copolymerizing monomers exemplified below. That is, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.); Hydroxy-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate and 2-hydroxypropyl methacrylate; Epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether; acrylic acid and methacrylic acid Carboxy groups such as itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.) Monomers having salts thereof: acrylamide, methacrylamide, N-alkyl acrylamide, N-alkyl methacrylamide, N, N-dialkyl acrylamide, N, N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl Group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.), N-alkoxyacrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide, N, N -Dialkoxymethacrylamide (alkoxy groups include methoxy, ethoxy, butoxy, isobutoxy, etc.), acryloylmorpholine, N-methylolacrylamide, N-methylolmethacrylamide, N-phenylacrylic Monomer having an amide group such as N-phenylmethacrylamide; monomer of acid anhydride such as maleic anhydride and itaconic anhydride; 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, Oxazoline groups such as 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline Containing monomer: methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, vinyl isocyanate, allyl isocyanate, styrene, α-methyl styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxysilane, alkyl maleic acid monoester, Rukirufumaru acid monoesters, alkyl itaconic acid monoester, acrylonitrile, methacrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene.

(Polyester resin)
The polyester resin comprises the following polybasic acid or its ester-forming derivative and polyol or its ester-forming derivative. That is, as the polybasic acid component, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid , Dimer acid, 5-sodium sulfoisophthalic acid and the like. A copolymer polyester resin is synthesized using two or more of these acid components. In addition, an unsaturated polybasic acid component such as maleic acid, itaconic acid or the like, or a hydroxycarboxylic acid such as p-hydroxybenzoic acid may be used in a slight amount. Examples of the polyol component include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylolpropane, poly (ethylene oxide) glycol, Examples include poly (tetramethylene oxide) glycol.

(Urethane resin)
The urethane resin includes a polyol, a polyisocyanate, a chain extender, a crosslinking agent, and the like. Examples of polyols include polyoxyethylene glycol, polyoxypropylene glycol, polyethers such as polyoxytetramethylene glycol, polyethylene adipate, polyethylene-butylene adipate, polycaprolactone, and the like by a dehydration reaction of dicarboxylic acid. There are polyesters to be produced, polycarbonates having carbonate bonds, acrylic polyols, castor oil and the like. Examples of polyisocyanates include tolylene diisocyanate, phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, and the like. Examples of chain extenders or crosslinking agents include ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, hydrazine, ethylenediamine, diethylenetriamine, triethylenetetramine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodicyclohexylmethane, Water etc. are mentioned.

  The polymer binder is preferably composed of at least one of a polyester resin and an acrylic resin from the viewpoint of coloring during recycling. Further, it is preferably composed of a mixture of polyester and acrylic resin. Further, from the viewpoint of refractive index adjustment and adhesiveness, an acrylic resin is preferably used as the binder resin. From the viewpoint of interface reflection and interference spot suppression, the refractive index of the polymer binder is preferably 1.40 to 1.70, more preferably 1.45 to 1.55, and even more preferably 1.45 to 1.50. It is a range.

[Crosslinking agent]
The coating layer in the present invention preferably contains a crosslinking agent, can improve the blocking resistance, and can enhance the effect of improving the adhesiveness. As the crosslinking agent, any one or more of epoxy, oxazoline, melamine, and isocyanate can be used. One of these may be used, or two or more may be used.

  Examples of the epoxy crosslinking agent include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, and glycidylamine compounds.

  Examples of the polyepoxy compound include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylol. Mention may be made of propane polyglycidyl ether.

  Examples of the diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and polypropylene glycol diester. Examples thereof include glycidyl ether and polytetramethylene glycol diglycidyl ether.

  Examples of the monoepoxy compound include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether.

  Examples of the glycidylamine compound include N, N, N ′, N ′,-tetraglycidyl-m-xylylenediamine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  As the oxazoline crosslinking agent, a polymer containing an oxazoline group is preferably used. This can be produced by polymerizing an addition-polymerizable oxazoline group-containing monomer alone or by copolymerizing with other monomers.

  Examples of the addition polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2. -Oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline. These may use 1 type and may use 2 or more types. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

  The other monomer used for copolymerization with the oxazoline group-containing copolymer may be any monomer that can be copolymerized with an addition-polymerizable oxazoline group-containing monomer. For example, alkyl acrylate, alkyl methacrylate (the alkyl group is methyl (Meth) acrylic acid esters such as a group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid Unsaturated carboxylic acids such as itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); acrylonitrile, methacrylonitrile, etc. Unsaturated nitriles; acrylamide, methacrylamide, N-a Kill acrylamide, N-alkyl methacrylamide, N, N-dialkyl acrylamide, N, N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, unsaturated amides such as t-butyl group, 2-ethylhexyl group, and cyclohexyl group); vinyl esters such as vinyl acetate, vinyl propionate, acrylic acid, methacrylic acid added with polyalkylene oxide; methyl ester; Vinyl ethers such as vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; Halogen-containing α and β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α and β- such as styrene and α-methylstyrene List unsaturated aromatic monomers Door can be. These monomers may be used alone or in combination of two or more.

  As the melamine crosslinking agent, a compound obtained by reacting a lower alcohol with a methylol melamine derivative obtained by condensing melamine and formaldehyde and a mixture thereof are preferable. As the lower alcohol, for example, methyl alcohol, ethyl alcohol, and isopropyl alcohol can be used.

  Examples of the methylol melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine.

  Examples of isocyanate crosslinking agents include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, metaxylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, tolylene diisocyanate and hexanetriol. Products, adducts of tolylene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'- List vitrylene-4,4 'diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate It can be.

  When the coating layer contains a crosslinking agent, the content of the crosslinking agent is preferably 5 to 30% by weight and more preferably 10 to 25% by weight per 100% by weight of the solid content of the coating layer. If it is less than 5% by weight, the effect of improving the blocking resistance is lowered. On the other hand, if it exceeds 30% by weight, the coating film becomes very hard, and it tends to be whitened in the stretching process, resulting in poor transparency.

[Fine particles]
In the present invention, the coating layer can contain fine particles in order to improve the winding property or to improve the blocking resistance in use at high temperatures. The average particle size of the fine particles contained in the coating layer is 20 to 400 nm, preferably 40 to 400 nm, particularly preferably 200 to 400 nm, and the effect of improving the winding property and blocking resistance can be enhanced. When the average particle size is less than 20 nm, the effect of improving the lubricity and scratch resistance is low, and the effect of improving the blocking resistance is also low. On the other hand, if it exceeds 400 nm, the particles are likely to fall off. The fine particles are usually contained in the composition of the coating layer.

  Examples of the fine particles include calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum oxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, tin oxide, antimony trioxide, and carbon. Inorganic fine particles such as black and molybdenum disulfide; organic fine particles such as acrylic cross-linked polymers, styrene cross-linked polymers, silicone resins, fluororesins, benzoguanamine resins, phenol resins, and nylon resins can be used. One of these may be used, or two or more may be used.

  The content of fine particles in the coating layer is preferably 0.1 to 10% by weight per 100% by weight of the composition of the coating layer, and the effect of improving the winding property and blocking resistance can be enhanced. When the content is less than 0.1% by weight, the effect of improving blocking resistance, slipperiness and scratch resistance is low. On the other hand, when the content exceeds 10% by weight, the cohesive force of the coating film is reduced and the effect of improving adhesiveness is low. Tend to be.

<Method for forming coating layer>
In the present invention, the coating agent used for coating the coating layer is preferably used in the form of an aqueous coating solution such as an aqueous solution, an aqueous dispersion or an emulsion. In order to form the coating layer, other components other than those described above, for example, an antistatic agent, a colorant, a surfactant, and an ultraviolet absorber may be blended as necessary.

  The solid concentration of the coating material used in the present invention is usually 20% by weight or less, preferably 1 to 10% by weight. If it is less than 1% by weight, the applicability to the aliphatic polyester film may be insufficient. On the other hand, if it exceeds 20% by weight, the stability of the coating liquid and the appearance of the coating layer may be deteriorated. .

  Application of the coating agent to the aliphatic polyester film can be carried out at any stage, but it is preferably carried out during the production process of the aliphatic polyester film, and in this case, the aliphatic before the orientation crystallization is completed. It is preferable to apply to the polyester film.

  Here, the aliphatic polyester film before completion of crystal orientation is an unstretched film, a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, and further in the longitudinal and transverse directions. It is a concept that includes a film that has been stretched and oriented at a low magnification in two directions (a biaxially stretched film before being finally re-stretched in the machine direction or the transverse direction to complete oriented crystallization). In particular, it is preferable to apply a coating agent to an unstretched film or a uniaxially stretched film oriented in one direction, and perform heat setting by longitudinal stretching and / or transverse stretching as it is. Moreover, it is preferable to apply a coating agent to an unstretched film and to heat-fix by stretching simultaneously in the vertical direction and the horizontal direction as it is.

  When applying a coating to a film, as a pretreatment to improve coating properties, the film surface is subjected to physical treatment such as corona surface treatment, flame treatment, plasma treatment, or a surfactant is wetted with the coating. It is preferable to mix as an agent. When a surfactant is blended in the coating material, it is preferably 1 to 10% by weight per 100% by weight of the solid content of the coating material.

  The surfactant promotes wetting of the coating material, particularly an aqueous coating solution, onto the polyester film, and improves the stability of the coating material. Examples of surfactants include anionic and nonionic surfactants such as polyoxyethylene fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, and alkyl sulfosuccinates. Can be mentioned.

  As the coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, and a curtain coating method can be applied. These may be applied alone or in combination.

  The thickness of the coating layer is preferably 20 to 150 nm, more preferably 30 to 120 nm, and particularly preferably 40 to 90 nm. When the thickness is within this range, the effect of improving adhesiveness can be increased, and the blocking resistance is excellent. If the thickness of the coating layer exceeds 150 nm, blocking tends to occur, and if it is less than 20 nm, the effect of improving adhesiveness tends to decrease.

  The refractive index of the coating layer is preferably 1.45 to 1.55, more preferably 1.45 to 1.50, and still more preferably 1.46 to 1.49. In the present invention, since the refractive index of the base film is in the range of 1.45 to 1.50, if the refractive index of the coating layer is in the above numerical range, the interface reflection or interference spots based on the difference in refractive index. The suppression effect can be increased, and the transparency improvement effect can be increased.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention does not receive limitation at all by this.

The evaluation methods used in the present invention and examples will be described below.
(1) Molecular weight:
The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer were measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene.
GPC measurement equipment
Detector: Differential refractometer RID-6A manufactured by Shimadzu Corporation
Column: Tosoh Corporation TSKgel G3000HXL, TSKgel G4000HXL, TSKgel G5000HXL and TSKguardcolumnHXL-L connected in series, or Tosoh Corporation TSKgel G2000HXL, TSKgel G3000HXL, TSKgel G3000HXL
10 μl of a sample having a concentration of 1 mg / m1 (chloroform containing 1% hexafluoroisopropanol) was injected at a temperature of 40 ° C. and a flow rate of 1.0 ml / min using chloroform as an eluent.

(2) Carboxyl group concentration:
The sample was dissolved in purified o-cresol, dissolved in a nitrogen stream, and bromocresol blue was used as an indicator, and the sample was determined with an ethanol solution of 0.05 N potassium hydroxide.

(3) Stereocomplex crystallinity (S), crystal melting temperature:
Stereocomplex crystallinity (S) and crystal melting temperature were measured by using DSC (TA-2920 manufactured by TA Instruments Co., Ltd.) under the conditions of a heating rate of 20 ° C./min. The crystal melting enthalpy was determined according to the following formula.
S (%) = [ΔHms / (ΔHmh + ΔHms)] × 100
(However, ΔHms is the crystal melting enthalpy of stereocomplex phase crystals, and ΔHmh is the crystal melting enthalpy of homophase crystals.)
The sample amount was 10 mg for the resin sample and 20 mg for the film sample.

(4) Light transmittance (maximum absorption wavelength of UV absorber):
Using a spectrophotometer UV-3101PC manufactured by Shimadzu Corporation, the transmittance of a sample film (film containing an ultraviolet absorber) at a wavelength of 200 nm to 800 nm was measured, and the absorbance at each wavelength was determined from the obtained transmittance. The absorbance curve (As (λ)) was obtained. On the other hand, similarly, the transmittance of a film not containing an ultraviolet absorber was measured to obtain an absorbance curve (Ar (λ)). From these, the absorbance curve (Au (λ)) of the ultraviolet absorber is obtained using the following formula, and the wavelength at the maximum peak from the obtained absorbance curve (Au (λ)) is determined as the maximum absorption wavelength ( nm). When there were a plurality of peak wavelengths, all the values were obtained.
Au (λ) = As (λ) −Ar (λ)
The measurement conditions were a scan speed of 200 nm / second, a slit width of 20 nm, a sampling pitch of 2.0 nm, and barium sulfate was used as the standard white plate.

(5) Polyester film thickness:
Using an electronic micrometer (K-312A type manufactured by Anritsu Corporation), the film thickness was measured at a needle pressure of 30 g.

(6) Haze:
According to JIS K6714-1958, total light transmittance Tt (%) and scattered light transmittance Td (%) are obtained, and haze ((Td / Tt) × 100) (%) is calculated.

(7) Thermal contraction rate:
Samples of 350 mm and 50 mm in width are cut out in the longitudinal direction and width direction of the film, marks at intervals of 300 mm are attached in the vicinity of both ends of the sample, and one end is fixed in an oven adjusted to a temperature of 90 ° C. Was left free for 30 minutes. This was taken out and allowed to cool to room temperature, and then the distance between the gauge points (mm) was measured (this length is assumed to be S), and the thermal shrinkage rate was determined by the following formula.
Thermal contraction rate (%) = ((300−S) / 300) × 100

(8) Coating layer thickness:
The film was cut into small pieces, embedded with an epoxy resin, and the film cross section was cut into a thickness of 50 nm with a microtome. This was stained with 2% osmic acid at 60 ° C. for 2 hours. The cross section of the dyed film was observed with a transmission electron microscope (LEM-2000), and the coating layer thickness was measured.

(9) Easy adhesion:
Under normal conditions (23 ° C., relative humidity 65% RH), 100 pieces of 1 mm ² crosscuts are put on the film on which the hard coat layer is formed, and cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. is pasted thereon. Using a rubber roller, the resin was reciprocated three times with a load of 19.6 N, then peeled off in the 90-degree direction, and evaluated according to the following criteria based on the number of remaining hard coat layers.
◎: 100 pieces ○: 80 to 99 pieces △: 50 to 79 pieces ×: 0 to 49 pieces

(10) Hydrolysis resistance:
After aging for 3000 hours in an environment of temperature 85 ° C. and humidity 85% RH, the elongation at break of the film is measured by ASTM-D61T, and the ratio (retention ratio) when the elongation at break before aging is 100% is calculated. And evaluated according to the following criteria.
◎: Retention ratio is 70% or more ○: Retention ratio is 50 or more and less than 70% △: Retention ratio is 30 or more and less than 50% ×: Retention ratio is less than 30%

(11) Isocyanate gas generation test:
The sample was heated at 160 ° C. for 5 minutes, and generation of isocyanate gas was confirmed by pyrolysis GC / MS analysis. GC / MS used was GC / MS Jms Q1000GC K9 manufactured by JEOL Ltd.

(12) Light deterioration resistance (strength retention evaluation):
Using a xenon weather meter (ATLAS CPS +) manufactured by Toyo Seiki Co., Ltd., the sample film was irradiated with an integrated irradiance of 765 W / m ² in a wavelength range of 300 to 800 nm for 100 hours. The obtained sample was cut into a width of 15 mm and tested with a Yasuda Seiki MIT cut resistance tester (weight: 250 gf, angle: 135 degrees, rotation speed: 175 times / minute), and the number of times until the film broke was as follows: Evaluation based on the criteria.
○: Number of breaks is 200 times or more ×: Number of breaks is less than 200 times

(13) Light resistance (yellowing evaluation):
Using a xenon weather meter (ATLAS CPS +) manufactured by Toyo Seiki Co., Ltd., the sample film was irradiated for 100 hours with an integrated irradiance of 765 W / m ² in the wavelength range of 300 to 800 nm, and L * a * b before and after irradiation. * (Chromaticity coordinates) and YI values were measured using a color difference meter (SZS-Σ90 manufactured by Nippon Denshoku Industries Co., Ltd.), and evaluated according to the following criteria.
○: ΔYI value (YI value after irradiation−YI value before irradiation) is less than 2 ×: ΔYI value (YI value after irradiation−YI value before irradiation) is 2 or more

[Reference Example 1] Production of cyclic carbodiimide compound (component C):
o- nitrophenol (0.11 mol) and pentaerythrityl tetra bromide (0.025 mol), potassium carbonate _{(0.33mol), N, N- N} 2 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 stirring device, 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), and dichloromethane 150 ml under N2 atmosphere. Charge and stir. 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 2] Production of poly L-lactic acid:
To 100 parts by weight of L-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%), 0.005 parts by weight of tin octylate was added, and the reaction was carried out in a reactor equipped with stirring blades in a nitrogen atmosphere. It reacts for 2 hours at 0 ° C., 1.2 times equivalent of phosphoric acid is added as a catalyst deactivator to the tin octylate, and then the remaining lactide is removed at 13.3 Pa to form chips and poly L-lactic acid Got.
The obtained poly L-lactic acid had a weight average molecular weight of 152,000, a glass transition temperature (Tg) of 55 ° C., and a melting point of 175 ° C.

[Reference Example 3] Production of stereocomplex polylactic acid:
In Reference Example 2, polymerization was performed under the same conditions except that L-lactide was changed to D-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%) to obtain poly-D-lactic acid.
The obtained poly-D-lactic acid had a weight average molecular weight of 151,000, a glass transition temperature (Tg) of 55 ° C., and a melting point of 175 ° C.
The obtained poly-D-lactic acid, poly-L-lactic acid obtained by the operation of Reference Example 2, 50 parts by weight and 0.1 parts by weight of phosphate metal salt (“ADEKA STAB” NA-71, manufactured by ADEKA) After mixing with a blender and vacuum-drying at 110 ° C. for 5 hours, melt kneading while evacuating at a cylinder temperature of 250 ° C. and a vent pressure of 13.3 Pa, extruding the strand into a water tank, chipping with a chip cutter, and aliphatic As a polyester resin (component A), a stereocomplex polylactic acid composition having a stereocomplex crystallinity (S) of 100% and a crystal melting temperature of 216 ° C. was obtained.

[Example 1]
After 100 parts by weight of the aliphatic polyester resin (component A) obtained by the procedure of Reference Example 3 was dried at 110 ° C. for 5 hours, Ciba Tinuvin 1577F (UV absorber A) was used as the UV absorber (component B). , Maximum absorption wavelength: 275 nm) is added so that the content in the film is 0.5% by weight, 1 part by weight of the cyclic carbodiimide compound (component C) obtained by the operation of Reference Example 1 is added, While mixing, the mixture was melt kneaded at a cylinder temperature of 230 ° C. with a twin-screw extruder, melted and extruded into a film at a die temperature of 220 ° C., and cooled and solidified with a cooling drum by a conventional method to form an unstretched film. Subsequently, the coating agent A (aqueous coating liquid with a solid content concentration of 6% by weight) shown in Table 1 was uniformly applied to both surfaces of the obtained unstretched film with a roll coater. Subsequently, the coated film was guided to a tenter, and biaxially stretched simultaneously at a temperature of 70 ° C. in the longitudinal direction to 2.8 times and in the transverse direction to 3.2 times, followed by heat setting at 195 ° C., and then in the transverse direction. 1.0% relaxation was performed to obtain an aliphatic polyester film having a thickness of 125 μm and a coating layer thickness of 60 nm. The evaluation results of the obtained aliphatic polyester film are shown in Table 2.

[Examples 2 to 4]
Optical with a thickness of 125 μm and a coating layer thickness of 60 nm was the same as in Example 1 except that the type and content of the ultraviolet absorber (component B), the type of coating, and the film production conditions were as shown in Table 2. An aliphatic polyester film was obtained. The evaluation results of the obtained aliphatic polyester film are shown in Table 2.

[Comparative Example 1]
An aliphatic polyester film having a thickness of 125 μm was obtained in the same manner as in Example 1 except that no ultraviolet absorber (component B) was contained, no coating layer was formed, and the film production conditions were as shown in Table 2. It was. The evaluation results of the obtained aliphatic polyester film are shown in Table 2.

[Comparative Examples 2 to 4]
The same procedure as in Comparative Example 1 was conducted except that the cyclic carbodiimide compound (C component) obtained by the operation of Reference Example 1 was not used and the type and content of the ultraviolet absorber (B component) were changed as shown in Table 2. Thus, an aliphatic polyester film having a thickness of 125 μm was obtained. The evaluation results of the obtained aliphatic polyester film are shown in Table 2.

[Comparative Example 5]
Instead of the cyclic carbodiimide compound (C component) obtained by the operation of Reference Example 1, a carbodiimide compound having a linear structure (“Carbodilite” LA-1 manufactured by Nisshinbo Chemical Co., Ltd.) was used, and an ultraviolet absorber (B component) ), And an aliphatic polyester film having a thickness of 125 μm and a coating layer thickness of 60 nm was obtained in the same manner as in Example 1 except that the film production conditions were as shown in Table 2. The evaluation results of the obtained aliphatic polyester film are shown in Table 2.

In addition, each component shown in Table 1 is as follows.
Acrylic resin: composed of 60 mol% methyl methacrylate / 30 mol% ethyl acrylate / 2 mol% 2-hydroxyethyl acrylate / 5 mol% N-methylolacrylamide (Tg = 40 ° C.). The acrylic was produced as follows according to the method described in Production Examples 1 to 3 of JP-A-63-37167. That is, 302 parts of ion-exchanged water was charged into a four-necked flask and the temperature was raised to 60 ° C. in a nitrogen stream, then 0.5 parts of ammonium persulfate and 0.2 parts of sodium bisulfite were added as a polymerization initiator, Further, a monomer mixture of 46.7 parts of methyl methacrylate, 23.3 parts of ethyl acrylate, 4.5 parts of 2-hydroxyethyl acrylate, and 3.4 parts of N-methylol acrylamide was added over 3 hours with a liquid temperature of 60 to It was added dropwise while adjusting to 70 ° C. The reaction was continued with stirring while maintaining the same temperature range for 2 hours after the completion of the dropping, and then cooled to obtain an aqueous dispersion of an acrylic resin having a solid content concentration of 25% by weight.
Polyester resin: Acid component is composed of 75 mol% of 2,6-naphthalenedicarboxylic acid / 20 mol% of isophthalic acid / 5 mol% of 5-sodium sulfoisophthalic acid, and glycol component is composed of 90 mol% of ethylene glycol / 10 mol% of diethylene glycol. (Tg = 80 ° C., weight average molecular weight 15000). The polyester resin was produced as follows. That is, 51 parts of dimethyl 2,6-naphthalenedicarboxylate, 11 parts of dimethyl isophthalate, 4 parts of dimethyl 5-sodium sulfoisophthalate, 31 parts of ethylene glycol and 2 parts of diethylene glycol were charged into a reactor. 05 parts were added and heated under a nitrogen atmosphere while controlling the temperature at 230 ° C., and the produced methanol was distilled off to conduct a transesterification reaction. Next, the temperature of the reaction system was gradually raised to 255 ° C. in a polymerization kettle with high motor torque of the stirrer, and the inside of the system was reduced in pressure by 1 mmHg to carry out a polycondensation reaction to obtain polyester 1 having an intrinsic viscosity of 0.56. 25 parts of this polyester was dissolved in 75 parts of tetrahydrofuran, and 75 parts of water was dropped into the resulting solution under high-speed stirring at 10,000 rpm to obtain a milky white dispersion. Then, this dispersion was subjected to a reduced pressure of 20 mmHg. After distillation, the tetrahydrofuran was distilled off to obtain an aqueous dispersion of a polyester resin (solid content concentration 20% by weight).
Cross-linking agent: glycerol polyglycidyl ether (trade name Denacol EX-313, manufactured by Nagase ChemteX Corporation)
Wetting agent: polyoxyethylene (n = 7) lauryl ether (trade name NAROACTY N-70, manufactured by Sanyo Chemical Co., Ltd.)

In addition, each ultraviolet absorber component shown in Table 2 is as follows.
UV absorber A: Ciba Tinuvin 1577F, triazines, maximum absorption wavelength: 275 nm
UV absorber B: BASF Nubinur 3050, hydroxybenzophenones, maximum absorption wavelength: 285 nm
Ultraviolet absorber C: BASF Nubinur 3049, hydroxybenzophenones, maximum absorption wavelength: 285 nm
Ultraviolet absorber D: ADEKA ADK STAB LA-46, triazines, maximum absorption wavelength: 275 nm
UV absorber E: Ciba Tinuvin 328, benzotriazoles, maximum absorption wavelength: 340 nm
Ultraviolet absorber F: Tinuvin 326 manufactured by Ciba, benzotriazoles, maximum absorption wavelength: 340 nm
Ultraviolet absorber G: Tinuvin 360 manufactured by ADEKA, benzotriazoles, maximum absorption wavelength: 345 nm

[Formation of hard coat layer]
A UV curable composition having the following composition is applied to any one of the aliphatic polyester films obtained in the above Examples and Comparative Examples so that the film thickness after curing is 5 μm using a roll coater. Was applied uniformly.
(UV curable composition)
Pentaerythritol acrylate: 45% by weight
N-methylolacrylamide: 40% by weight
N-vinylpyrrolidone: 10% by weight
1-hydroxycyclohexyl phenyl ketone: 5% by weight
Then, it was cured by irradiating with ultraviolet rays for 30 seconds with a high-pressure mercury lamp having an intensity of 80 W / cm to form a hard coat layer, and similarly, a hard coat layer was formed on the opposite surface, and a hard coat film was obtained and evaluated. Used for.

  The aliphatic polyester film of the present invention can be suitably used as an optical film for touch panels and the like because strength deterioration and yellowing due to ultraviolet irradiation are suppressed.

Claims (16)

  Aliphatic polyester resin (component A), ultraviolet absorber (component B) having a maximum absorption wavelength at a wavelength of 260 to 320 nm, and one carbodiimide group, the first nitrogen and the second nitrogen are bonded by a bonding group An aliphatic polyester film containing a compound (C component) containing at least a cyclic structure.   The aliphatic polyester film according to claim 1, wherein the C component has 8 to 50 atoms forming a cyclic structure. The aliphatic polyester film according to claim 1, wherein the cyclic structure in component C 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 aliphatic polyester 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 aliphatic polyester film according to claim 1, wherein the component C 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.) The aliphatic polyester film according to claim 5, wherein Q _a 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. ^{Ar 1, Ar 2, R 1} , R 2, X 1, is the same as ^{X 2,} X ^3, s and k in.) The aliphatic polyester film according to claim 1, wherein the component C 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 aliphatic polyester 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 aliphatic polyester film according to claim 7, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer. The aliphatic polyester film according to claim 1, wherein the component C 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.) The aliphatic polyester film 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 aliphatic 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 aliphatic polyester film according to any one of claims 1 to 12, wherein the component A contains a polylactic acid resin.   The aliphatic polyester film according to claim 13, wherein the polylactic acid resin forms a stereocomplex crystal.   15. The aliphatic polyester film according to claim 1, wherein the content of the ultraviolet absorber (component B) is 0.001 to 5% by weight with respect to the weight of the film.   The aliphatic polyester film according to any one of claims 1 to 15, wherein the ultraviolet absorber (component B) is a hydroxybenzophenone or a triazine.