WO2014041827A1

WO2014041827A1 - Aromatic polyester film, back sheet for solar cell module, and solar cell module

Info

Publication number: WO2014041827A1
Application number: PCT/JP2013/056427
Authority: WO
Inventors: 橋本　斉和; 福田　誠
Original assignee: 富士フイルム株式会社
Priority date: 2012-09-14
Filing date: 2013-03-08
Publication date: 2014-03-20
Also published as: JP5827255B2; JP2014129500A

Abstract

The purpose of the present invention is to provide a white aromatic polyester film that does not give rise to cutting debris at the time of cutting the aromatic polyester film. This aromatic polyester film comprises: a cyclic carbodiimide compound that includes a carbodiimide group in the ring skeleton thereof and that has, in the molecule thereof, at least one cyclic structure in which the first nitrogen and the second nitrogen of the carbodiimide group are bonded by a bonding group, or a ketenimine compound; fine particles; and an aromatic polyester resin. This aromatic polyester film is characterized in that: the content by percentage of the cyclic carbodiimide compound or the ketenimine compound is 0.1-5 mass% to the mass of the aromatic polyester resin; the particle size of the fine particles is 0.1-10 µm; the content by percentage of the fine particles is 1-10 mass% to the mass of the aromatic polyester resin; a portion of the fine particles is aggregated; and the aggregation rate of the fine particles is 10-50%.

Description

Aromatic polyester film, solar cell module backsheet and solar cell module

The present invention relates to an aromatic polyester film, a back sheet for a solar cell module, and a solar cell module. Specifically, the present invention relates to a cyclic aromatic carbodiimide compound, a white aromatic polyester film containing fine particles, a solar cell module backsheet having the aromatic polyester film, and a solar cell in which the solar cell module backsheet is laminated. The present invention relates to a battery module.

Generally, a solar cell module is formed by laminating glass or a front sheet / transparent filling material (sealing material) / solar cell element / sealing material / back sheet (BS) in this order from the light-receiving surface side on which sunlight enters. It has a structure. The back sheet (BS) is provided in the outermost layer of the solar cell module and functions to protect the solar cell element. When the solar cell module is installed in a roof, the backsheet (BS) is expected to be exposed to wind and rain or placed in a high temperature and humidity environment for a long period of time, and therefore excellent weather resistance is required.

Conventionally, a polyester film, particularly a polyethylene terephthalate (hereinafter referred to as PET) film has been used for a back sheet for a solar cell module. Since these films have poor hydrolysis resistance, the molecular weight decreases due to hydrolysis, and embrittlement progresses, resulting in a decrease in mechanical properties. For this reason, practical strength could not be maintained over a long period of time as a back sheet for solar cells.

In order to solve this problem, for example, Patent Documents 1 and 2 disclose that a cyclic carbodiimide compound is mixed into a back sheet as a terminal blocking agent in order to improve hydrolysis resistance. The cyclic carbodiimide compound reacts with the terminal carboxy group of the polyester to link the produced isocyanate to the terminal. When a cyclic carbodiimide compound is used as the end-capping agent, there is an advantage that the isocyanate compound is not liberated and volatilization of the isocyanate gas can be suppressed.
Patent Document 3 discloses that a ketene imine compound is used as an end-capping agent for polyester in order to improve hydrolysis resistance. Here, it has been proposed to suppress hydrolysis of the polyester by reacting the ketene imine compound with the terminal carboxyl group of the polyester.

The back sheet for a solar cell module is preferably a white film in order to reflect sunlight and increase power generation efficiency. In order to make a polyester film white, particles such as titanium oxide and silica are contained, or fine bubbles (voids) are generated in the film.

International publication 2011/093478 pamphlet Japanese Unexamined Patent Publication No. 2011-258641 US Pat. No. 3,692,745

However, the conventional white aromatic polyester film containing a terminal blocking agent such as a cyclic carbodiimide compound or a ketenimine compound has a high molecular weight due to the reaction between the terminal carboxylic acid of the aromatic polyester film and the terminal blocking agent. The inventors of the present application have clarified that cutting waste is likely to be generated when cutting a polyester film.

When cutting waste is generated during the process of processing the polyester film, the cutting waste and particles in the cutting waste fall off, which causes a problem because process contamination occurs.
Further, when the cutting waste adheres to the polyester film, it is clear from the examination by the inventors of the present application that when the polyester film and the solar cell panel are bonded and used for a long time, adhesion failure occurs and the polyester film peels off. Became.

Therefore, in order to solve the problems of the prior art, the inventors of the present application have studied for the purpose of providing a white aromatic polyester film that has hydrolysis resistance but does not generate cutting waste during cutting. Advanced.

As a result of intensive studies to solve the above problems, the inventors of the present application have determined the content of the cyclic carbodiimide compound or ketene imine compound and fine particles in the aromatic polyester film containing the cyclic carbodiimide compound or ketene imine compound and fine particles. It was found that cutting waste is less likely to occur when cutting a polyester film by setting the particle diameter within a certain range and regulating the particle size and aggregation rate thereof.
Specifically, the present invention has the following configuration.

[1] A cyclic carbodiimide compound or ketene imine compound containing one carbodiimide group in the ring skeleton and having at least one cyclic structure in the molecule in which the first nitrogen and the second nitrogen are bonded by a bonding group, and fine particles, And the content of the cyclic carbodiimide compound or the ketene imine compound is 0.1 to 5% by mass with respect to the mass of the aromatic polyester resin, and the particle size of the fine particles is 0.00. 1 to 10 μm, the content of the fine particles is 1 to 10% by mass with respect to the mass of the aromatic polyester resin, a part of the fine particles are aggregated, and the aggregation rate is 10 to 50%. An aromatic polyester film characterized by being.
[2] The aromatic polyester film of [1], wherein the cyclic carbodiimide compound is represented by the following general formula (O-1) or general formula (O-2).

(In general formula (O-1), R ¹ and R ⁵ each independently represents an alkyl group, an aryl group or an alkoxy group. R ² to R ⁴ and R ⁶ to R ⁸ each independently represents a hydrogen atom, Represents an alkyl group, an aryl group or an alkoxy group, R ¹ to R ⁸ may combine with each other to form a ring, X ¹ and X ² each independently represents a single bond, —O—, —CO—, Represents —S—, —SO ₂ —, —NH— or —CH ₂ —, and L ¹ represents a divalent linking group.

(In the general formula (O-2), R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ each independently represents an alkyl group, an aryl group or an alkoxy group. R ¹² to R ¹⁴ , R ¹⁶ to R ¹⁸ , R ²² ~ ^{R 24} and ^R 26 ^{~ R 28} each independently represent a hydrogen atom, an alkyl group, ^.R represents an aryl group or an alkoxy group 11 ^{~ R 28} are bonded may also form a ring ^{.X 11} together, X ¹² , X ²¹ and X ²² each independently represents a single bond, —O—, —CO—, —S—, —SO ₂ —, —NH— or —CH ₂ —, wherein L ² represents a tetravalent group. Represents a linking group.)
[3] In the general formulas (O-1) and (O-2), R ¹ and R ⁵ , and R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ are each independently a secondary or tertiary alkyl group, Or the aromatic polyester film as described in [2] characterized by representing an aryl group.
[4] The aromatic polyester film as described in [2] or [3], wherein in the general formula (O-1), R ² and R ⁶ are both hydrogen atoms.
[5] The aromatic polyester film according to [1], wherein the ketene imine compound is represented by the following general formula (1).

(In the general formula (1), R ₁ and R ₂ each independently represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group; ₃ represents an alkyl group or an aryl group.)
[6] The aromatic polyester film according to [1], wherein the ketene imine compound is represented by the following general formula (2).

(In General Formula (2), R ₁ represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ represents L ₁ as a substituent. Represents an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group, wherein R ₃ represents an alkyl group or an aryl group, and n is 1 to 4. Represents an integer, and L ₁ represents an n-valent linking group.)
[7] The aromatic polyester film according to [6], wherein n in the general formula (2) is 3 or 4.
[8] The aromatic polyester film according to [1], wherein the ketene imine compound is represented by the following general formula (3).

(In General Formula (3), R ₁ and R ₅ represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ and R ₄ Represents an alkyl group having L ₂ as a substituent, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group or an aryloxycarbonyl group, and R ₃ and R ₆ are an alkyl group or an aryl group. L ₂ represents a single bond or a divalent linking group.)
[9] The molecular weight of the portion other than the nitrogen atom constituting the ketene imine of the ketene imine compound and the substituent bonded to the nitrogen atom is 320 or more, [5] to [8] Aromatic polyester film.
[10] The aromatic polyester resin mainly contains terephthalic acid, naphthalenedicarboxylic acid as a dicarboxylic acid component, and ethylene glycol as a diol component,
The aromatic polyester according to any one of [1] to [9], wherein the intrinsic viscosity (IV) is 0.7 to 0.9 g / dl and the acid value (AV) is 1 to 20 eq / ton. the film.
[11] A laminated film comprising at least one layer of the aromatic polyester film according to any one of [1] to [10], and having 2 to 8 layers.
[12] The laminated film according to [11], wherein a variation rate of a thickness of a layer having the largest thickness among the layers constituting the laminated film is 1 to 10%.
[13] A cyclic carbodiimide compound or a ketenimine compound having at least one cyclic structure in the molecule containing one carbodiimide group in the ring skeleton and having the first nitrogen and the second nitrogen bonded by a linking group; In the method for producing an aromatic polyester film containing an aromatic polyester resin, a step of kneading the aromatic polyester resin and the fine particles to prepare a master pellet, and mixing the master pellet and the aromatic polyester pellet After extrusion, a step of casting from a die onto a cooling drum to form a film, and at least one of the step of preparing the master pellet or the step of forming the film is a step of mixing the cyclic carbodiimide compound or the ketene imine compound The fine particles have a particle size of 0.1 to 10 μm The content of the fine particles is 1 to 10% by mass with respect to the mass of the aromatic polyester resin, and the step of preparing the master pellet kneads the aromatic polyester resin and the fine particles with a screw rotational torque. A process for producing an aromatic polyester film, wherein the screw rotational torque is varied by 0.1 to 10%.
[14] The method for producing an aromatic polyester film as described in [13], wherein the screw rotational torque is given a fluctuation of 1 to 100 times / minute.
[15] The method for producing an aromatic polyester film according to [13] or [14], wherein the film forming step includes a step of imparting a temperature distribution of 1 to 10 ° C. to the inside of the die. .
[16] The aromatic polyester film according to any one of [13] to [15], wherein the cyclic carbodiimide compound is represented by the following general formula (O-1) or general formula (O-2): Manufacturing method.

(In the general formula (O-2), R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ each independently represents an alkyl group, an aryl group or an alkoxy group. R ¹² to R ¹⁴ , R ¹⁶ to R ¹⁸ , R ²² ~ ^{R 24} and ^R 26 ^{~ R 28} each independently represent a hydrogen atom, an alkyl group, ^.R represents an aryl group or an alkoxy group 11 ^{~ R 28} are bonded may also form a ring ^{.X 11} together, X ¹² , X ²¹ and X ²² each independently represents a single bond, —O—, —CO—, —S—, —SO ₂ —, —NH— or —CH ₂ —, wherein L ² represents a tetravalent group. Represents a linking group.)
[17] In the general formulas (O-1) and (O-2), R ¹ and R ⁵ , and R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ are each independently a secondary or tertiary alkyl group, Or the aryl group is represented, The manufacturing method of the aromatic polyester film as described in [16] characterized by the above-mentioned.
[18] The method for producing an aromatic polyester film of [16] or [17], wherein in the general formula (O-1), R ² and R ⁶ are both hydrogen atoms.
[19] The method for producing an aromatic polyester film according to any one of [13] to [15], wherein the ketene imine compound is represented by the following general formula (1).

(In the general formula (1), R ₁ and R ₂ each independently represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group; ₃ represents an alkyl group or an aryl group.)
[20] The method for producing an aromatic polyester film according to any one of [13] to [15], wherein the ketene imine compound is represented by the following general formula (2).

(In General Formula (2), R ₁ represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ represents L ₁ as a substituent. Represents an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group, wherein R ₃ represents an alkyl group or an aryl group, and n is 1 to 4. Represents an integer, and L ₁ represents an n-valent linking group.)
[21] The method for producing an aromatic polyester film according to [20], wherein in the general formula (2), n is 3 or 4.
[22] The method for producing an aromatic polyester film according to any one of [13] to [15], wherein the ketene imine compound is represented by the following general formula (3).

(In General Formula (3), R ₁ and R ₅ represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ and R ₄ Represents an alkyl group having L ₂ as a substituent, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group or an aryloxycarbonyl group, and R ₃ and R ₆ are an alkyl group or an aryl group. L ₂ represents a single bond or a divalent linking group.)
[23] The molecular weight of the portion other than the nitrogen atom constituting the ketene imine of the ketene imine compound and the substituent bonded to the nitrogen atom is 320 or more, [19] to [22] Method for producing an aromatic polyester film.
[24] An aromatic polyester film produced by the production method according to any one of [13] to [23].
[25] A solar cell module backsheet using the aromatic polyester film according to any one of [1] to [10] and [24].
[26] A solar cell module back sheet using the laminated film according to [11] or [12].
[27] A solar cell module using the back sheet for a solar cell module according to [25] or [26].

According to the present invention, it is possible to obtain an aromatic polyester film that has hydrolysis resistance but does not generate cutting waste during cutting. Thereby, the aromatic polyester film of this invention becomes favorable for adhesiveness with a solar cell panel, and is used suitably as a back sheet | seat of a solar cell.

FIG. 1 is a schematic view showing a configuration example of a twin-screw extruder for carrying out the method for producing a polyester film according to the present invention.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

The present invention relates to an aromatic polyester film. The aromatic polyester film of the present invention contains a cyclic carbodiimide compound or a ketene imine compound, fine particles, and an aromatic polyester resin. The content of the cyclic carbodiimide compound or ketene imine compound is 0.1 to 5% by mass with respect to the mass of the aromatic polyester resin. The particle diameter of the fine particles is 0.1 to 10 μm, and the content of the fine particles is 1 to 10% by mass with respect to the mass of the aromatic polyester resin. Part of the fine particles is aggregated, and the aggregation rate is 10 to 50%.

(Aromatic polyester resin)
The aromatic polyester resin can be obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol or a high molecular weight diol. Examples of aromatic dicarboxylic acids or ester-forming derivatives thereof include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, paraphenylene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, dimethyl naphthalene dicarboxylate, And dimethyl paraphenylene dicarboxylate. These may be used alone or in combination of two or more.

Examples of the low molecular weight aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and 1,5-pentane. Examples thereof include diol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. These may be used alone or in combination of two or more.
Examples of the high molecular weight diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and the like. These may be used alone or in combination of two or more.

Examples of the crystalline aromatic polyester composed of the above components include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, butanediol terephthalate polytetramethylene glycol copolymer, and the like. Can be mentioned. These may be used alone or in combination of two or more. Particularly preferred among the aromatic polyesters described herein are those using terephthalic acid and naphthalenedicarboxylic acid as main components as dicarboxylic acids, and those having ethylene glycol and cyclohexanedimethanol as main components as diols. Preferred are polyethylene terephthalate, polyethylene naphthalate, and polycyclohexanedimethylene terephthalate, and more preferred are polyethylene terephthalate and polyethylene naphthalate.

The shape of the aromatic polyester resin is not particularly limited, but is preferably a pellet. By using the aromatic polyester resin as pellets, mixing with fine particles described later can be facilitated.
The shape of the pellet may be amorphous (crushed), cylindrical, or rectangular, but is preferably cylindrical or rectangular from the viewpoint of pellet productivity, and is preferably cylindrical from the viewpoint of supply stability to the extruder. . This is because the cylindrical shape does not easily crush the corners and does not easily generate powder, and therefore does not bridge (clog) in the hopper.

The volume of the pellet is preferably 1 to 1000 mm ³ , more preferably 3 to 100 mm ³ , and still more preferably 5 to 60 mm ³ . If it is less than this range, it is easy to block in the hopper, which is not preferable. Moreover, when this range is exceeded, when it blows from the silo which stores the pellet to an extruder, it is difficult to convey and it is not preferable.

(Fine particles)
The aromatic polyester film of the present invention contains fine particles. The fine particles serve to make the aromatic polyester film white. Fine particles include calcium carbonate, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, alumina, aluminum hydroxide, hydroxyapatite, silica, mica, talc, kaolin It is preferable to use at least one selected from inorganic fine powders such as clay, glass powder, asbestos powder, zeolite and silicate clay. Of these, titanium oxide and barium sulfate are preferably used.

Further, from the viewpoint of enhancing the effect of improving the reflectance of the obtained film, those having a large refractive index difference from the composition constituting the film are preferably used. That is, it is preferable that the inorganic fine powder has a large refractive index. Specifically, for example, when an aromatic polyester resin is used, at least one selected from the group consisting of calcium carbonate, barium sulfate, titanium oxide, and zinc oxide having a refractive index of 1.6 or more is used. More preferably, among these, it is particularly preferable to use titanium oxide. By using titanium oxide, it is possible to impart high reflection performance to the film with a smaller filling amount, and it is possible to obtain a film having high reflection performance even with a thin wall.

Examples of titanium oxide include crystalline titanium oxides such as anatase-type titanium oxide and rutile-type titanium oxide. From the viewpoint of increasing the difference in refractive index from the polymer, titanium oxide having a refractive index of 2.7 or more is preferable. For example, a crystal form of rutile titanium oxide is preferably used.

It is particularly preferable to use high-purity titanium oxide having high purity among titanium oxides. Here, the high-purity titanium oxide is a titanium oxide having a small light absorption ability with respect to visible light, and means a material having a small content of colored elements such as vanadium, iron, niobium, copper, and manganese. In the present specification, titanium oxide in which the content of vanadium contained in titanium oxide is 5 ppm or less is referred to as high-purity titanium oxide. From the viewpoint of reducing the light absorption ability of high-purity titanium oxide, it is preferable to reduce coloring elements such as iron, niobium, copper, and manganese contained in titanium oxide.

In order to improve the dispersibility of the fine particles in the polymer, the surface of the filler may be subjected to a surface treatment with a silicone compound, a polyhydric alcohol compound, an amine compound, a fatty acid, a fatty acid ester, or the like. For example, in order to improve the dispersibility of titanium oxide in an aliphatic polyester resin and suppress the photocatalytic activity of titanium oxide, surface treatment may be performed on the surface of titanium oxide. As the surface treatment agent, for example, at least one selected from the group consisting of at least one inorganic compound selected from the group consisting of alumina, silica, zirconia, and the like, a siloxane compound, a silane coupling agent, a polyol, and polyethylene glycol. These organic compounds can be used. Moreover, you may use combining these inorganic compounds and organic compounds.

¡Inorganic fine powder and organic fine powder may be used in combination as fine particles. In addition, a plurality of types of fine particles can be used in combination. For example, titanium oxide and other fillers, high-purity titanium oxide and other fine particles may be used in combination.

The particle size of the fine particles used in the present invention is 0.1 to 10 μm. The particle diameter of the fine particles may be 0.1 to 10 μm, preferably 0.15 to 9 μm, and more preferably 0.2 to 8 μm. By setting the particle diameter of the fine particles within the above range, the light reflection efficiency can be increased. In particular, it is preferable because the reflection efficiency of light in the visible region can be increased.

In the present invention, the content of fine particles in the aromatic polyester film is 1 to 10% by mass with respect to the mass of the aromatic polyester resin. The content of fine particles may be 1 to 10% by mass, preferably 1.5 to 8% by mass, and more preferably 2 to 6% by mass. By setting the addition amount of the fine particles within the above range, the light reflection efficiency can be set within an appropriate range. If the addition amount of the fine particles exceeds the above upper limit, the amount of polyester as a binder with respect to the fine particles becomes low, the fine particles cannot be fixed, and it is easy to peel off at the time of cutting.

In the present invention, some of the fine particles are aggregated, and the aggregation rate is 10 to 50%. The aggregation rate of the fine particles may be 10 to 50%, preferably 15 to 45%, and more preferably 20 to 40%. By setting the agglomeration rate of the fine particles within the above range, generation of cutting waste during cutting can be suppressed. When the agglomeration rate exceeds the above range, agglomeration of particles increases, and when the cutting blade passes therethrough, an impact is likely to occur, and accordingly, fine particles are peeled off and cutting waste is easily generated.
Here, the aggregation rate of the fine particles indicates a ratio of the number of aggregated particles in 100 particles (particles and aggregated particles) observed using an optical microscope or an electron microscope. In addition, the number of aggregated particles counts the aggregate (particle lump) in which two or more particles aggregated as one particle.

When the fine particles are aggregated, the stress concentration point at the time of cutting can be reduced, and the destruction of the PET can be suppressed. Further, the fine particles are aggregated to have an apparently large size and are difficult to peel off. For example, when two fine particles are connected, the apparent particle size becomes long and it is difficult to fall off the cut surface. Thereby, generation | occurrence | production of cutting waste can be prevented effectively.

The apparent number of fine particles decreases due to aggregation. However, only the apparent number of fine particles is reduced, and the number of fine particles actually contained is not reduced. For this reason, the reflectance of light is not lowered. On the other hand, when the same number of particles having a large particle size as the aggregate is contained without agglomerating the fine particles, the light reflectance decreases. That is, in the present invention, it is possible to suppress the generation of cutting waste while maintaining the light reflectivity by aggregating fine particles rather than containing the same number of particles having a large particle diameter as the aggregate. I have to.

The fine particle aggregate as described above is formed by adjusting the manufacturing process of the master pellet.
The master pellet is formed from a kneaded polyester resin and fine particles. Here, the content of the fine particles is 30 to 70% by mass with respect to the polyester resin. It is preferable to use fine particles and polyester resin that have been sufficiently dried until the water content becomes 100 ppm or less. The polyester resin is preferably a pellet. By using the pellet-shaped polyester resin, the fine particles can be mixed uniformly.
Furthermore, it is preferable to sufficiently dry the obtained master pellets until the water content becomes 100 ppm or less.

The master pellets thus obtained are put into an extruder and kneaded. At this time, a fluctuation of 0.1 to 10%, preferably 0.2 to 5%, more preferably 0.3 to 3% is given to the rotational torque of the screw in the extruder.
Here, the torque fluctuation rate refers to the rate of change with respect to the average value. Specifically, the torque is measured for 1 minute, and an increase rate or a decrease rate in which the torque is increased or decreased is indicated by a value obtained by multiplying the average value of the torque during that time by the above fluctuation rate.

By varying the torque, the force applied to the resin can be varied, and a flow can be applied so that the resin flows non-uniformly. As a result, the resin stays instantaneously in the screw, and an aggregate of fine particles is formed here.
By setting the torque fluctuation within the above range, the aggregation rate of the fine particles can be within the range of 10 to 50%. If the torque fluctuation is less than the above range, it is difficult to form aggregates, which is not preferable. On the other hand, if the torque fluctuation exceeds the above range, the aggregation rate of fine particles exceeds 50%, which is not preferable. Such extrusion is preferable because it is easy to adjust the torque by using a twin screw.

The torque fluctuation of the screw as described above may be continuously and constantly applied, but it is preferably applied 1 time / minute to 100 times / minute, more preferably 3 times / minute to 80 times / minute. It is more preferable to apply 5 times / minute to 60 times / minute. By setting the torque fluctuation within the above range, the fine particles can be aggregated in a desired range.
Here, the torque fluctuation of one time / minute means that the torque is measured for one minute, and the torque may be up or down once from the average value by a certain amount. Here, the range above a certain level from the average value refers to a range defined by the rate of change in torque fluctuation. Specifically, the number of torque fluctuations of the screw can be obtained by measuring the number of times the torque fluctuations within a range where the torque fluctuation change rate exceeds 0.1% and does not exceed 10% per minute. it can.

Note that such torque fluctuation can be achieved by changing the power supplied to the motor that rotates the screw. The fluctuation of the electric power supplied to the motor can be achieved by increasing or decreasing the current value supplied to the motor. For example, this can be achieved by periodically or randomly increasing or decreasing the supply current value to the motor by computer control.

(Cyclic carbodiimide compound)
The aromatic polyester film of the present invention contains a cyclic carbodiimide compound. A cyclic carbodiimide compound containing one carbodiimide group in the ring skeleton and having in the molecule at least one cyclic structure in which the first nitrogen and the second nitrogen are bonded by a bonding group functions as a cyclic sealant.
A cyclic carbodiimide compound can be prepared by the method described in International Publication 2011/093478 pamphlet.

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

Here, the number of atoms in the ring structure means the number of atoms directly constituting the ring structure, for example, 8 for a 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 selected in the range of 10 to 30, more preferably 10 to 20, and particularly preferably 10 to 15.

As the cyclic carbodiimide compound, it is preferable to use a cyclic carbodiimide compound represented by the following general formula (O-1) or general formula (O-2).
Hereinafter, preferred structures of the cyclic carbodiimide compound of the present invention will be described in the order of the following general formula (O-1) and general formula (O-2).

First, the cyclic carbodiimide compound represented by the general formula (O-1) will be described.

In general formula (O-1), R ¹ and R ⁵ each independently represents an alkyl group, an aryl group or an alkoxy group. R ² to R ⁴ and R ⁶ to R ⁸ each independently represents a hydrogen atom, an alkyl group, an aryl group or an alkoxy group. R ¹ to R ⁸ may be bonded to each other to form a ring. X ¹ and X ² each independently represents a single bond, —O—, —CO—, —S—, —SO ₂ —, —NH— or —CH ₂ —. L ¹ represents a divalent linking group.

In the general formula (O-1), R ¹ and R ⁵ each independently represents an alkyl group, an aryl group or an alkoxy group, preferably an alkyl group or an aryl group, preferably a secondary or tertiary alkyl group or Representing an aryl group is more preferred from the viewpoint of suppressing the reaction between the isocyanate end linked to the terminal of the polyester and the hydroxyl terminal of the polyester and suppressing the thickening, and particularly preferably a secondary alkyl group.

The alkyl group represented by R ¹ and R ⁵ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, and an alkyl group having 2 to 6 carbon atoms. It is particularly preferred. The alkyl group represented by R ¹ and R ⁵ may be linear, branched or cyclic, but is branched or cyclic, and isocyanate and polyester linked to the end of the polyester. It is preferable from the viewpoint of suppressing the reaction at the hydroxyl terminal and suppressing thickening. The alkyl group represented by R ¹ and R ⁵ is preferably a secondary or tertiary alkyl group, and more preferably a secondary alkyl group. The alkyl group represented by R ¹ and R ⁵ is methyl group, ethyl group, n-propyl group, sec-propyl group, iso-propyl group, n-butyl group, tert-butyl group, sec-butyl group, iso-butyl. Group, n-pentyl group, sec-pentyl group, iso-pentyl group, n-hexyl group, sec-hexyl group, iso-hexyl group, cyclohexyl group, etc., among which iso-propyl group, tert group -Butyl group, iso-butyl group, iso-pentyl group, iso-hexyl group, and cyclohexyl group are preferable, iso-propyl group, cyclohexyl group, and tert-butyl group are more preferable, and iso-propyl group and cyclohexyl group are particularly preferable. .
The alkyl group represented by R ¹ and R ⁵ may further have a substituent, and the substituent is not particularly limited. However, the alkyl group represented by R ¹ and R ⁵ preferably has no further substituent from the viewpoint of reactivity with the carboxylic acid.

The aryl group represented by R ¹ and R ⁵ is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and an aryl group having 6 carbon atoms. Particularly preferred. The aryl group represented by R ¹ and R ⁵ may be an aryl group formed by condensing R ¹ and R ² or condensing R ⁵ and R ^6, but R ¹ and R ⁵ are each represented by R ² It is preferable that the ring is not condensed with R ⁶ . Examples of the aryl group represented by R ¹ and R ⁵ include a phenyl group and a naphthyl group, and among them, a phenyl group is more preferable.
The aryl group represented by R ¹ and R ⁵ may further have a substituent, and the substituent is not particularly limited. However, the aryl group represented by R ¹ and R ⁵ preferably has no further substituent from the viewpoint of reactivity with the carboxylic acid.

The alkoxy group represented by R ¹ and R ⁵ is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and an alkoxy group having 2 to 6 carbon atoms. It is particularly preferred. The alkoxy group represented by R ¹ and R ⁵ may be linear, branched or cyclic, but is branched or cyclic, and isocyanate and polyester linked to the end of the polyester. It is preferable from the viewpoint of suppressing the reaction at the hydroxyl terminal and suppressing thickening. Preferred examples of alkoxy groups R ¹ and R ⁵ represent, the may include groups terminated -O- is linked alkyl group represented by R ¹ and R ^5, the same preferable ranges R ¹ and R ⁵ The preferred alkyl group represented is a group in which —O— is linked to the terminal.
The alkoxy group represented by R ¹ and R ⁵ may further have a substituent, and the substituent is not particularly limited. However, the alkoxy group represented by R ¹ and R ⁵ preferably has no further substituent from the viewpoint of reactivity with carboxylic acid.

R ¹ and R ⁵ may be the same or different, but are preferably the same from the viewpoint of cost.

In the general formula (O-1), R ² to R ⁴ and R ⁶ to R ⁸ each independently represents a hydrogen atom, an alkyl group, an aryl group or an alkoxy group, and a hydrogen atom, an alkyl having 1 to 20 carbon atoms Group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and particularly preferably a hydrogen atom.
The alkyl group, aryl group or alkoxy group represented by R ² to R ⁴ and R ⁶ to R ⁸ may further have a substituent, and the substituent is not particularly limited.
In the cyclic carbodiimide compound of the present invention, it is preferable that R ² and R ⁶ are both hydrogen atoms in the general formula (O-1) from the viewpoint of easily introducing bulky substituents into R ¹ and R ⁵ . Here, WO2010 / 072111 exemplifies compounds in which an alkyl group or an aryl group is substituted at a site corresponding to R ² and R ⁶ in the general formula (O-1) (meta position with respect to the carbodiimide group). However, these compounds cannot suppress the reaction between the isocyanate linked to the terminal of the polyester and the hydroxyl terminal of the polyester, and in the general formula (O-1), the sites corresponding to R ² and R ⁶ It is difficult to introduce a substituent at (ortho position with respect to the carbodiimide group).

In the general formula (O-1), R ¹ to R ⁸ may be bonded to each other to form a ring. The ring formed at this time is not particularly limited, but is preferably an aromatic ring. For example, two or more of R ¹ to R ⁴ may be bonded to each other to form a condensed ring, and an arylene group or heteroarylene group having 10 or more carbon atoms is formed with a benzene ring substituted by R ¹ to R ⁴ May be. Examples of the arylene group having 10 or more carbon atoms formed at this time include aromatic groups having 10 to 15 carbon atoms such as naphthalenediyl group.
Similarly, for example, two or more of R ⁵ to R ⁸ may be bonded to each other to form a condensed ring, and an arylene group or heteroarylene having 10 or more carbon atoms together with a benzene ring substituted by R ⁵ to R ^8. A preferred range at that time is the same as the preferred range when an arylene group or heteroarylene group having 10 or more carbon atoms is formed together with the benzene ring substituted by R ¹ to R ⁴ .
However, in the cyclic carbodiimide compound of the present invention, it is preferable that R ¹ to R ^{8 in the} general formula (O-1) are not bonded to each other to form a ring.

In the general formula (O-1), X ¹ and X ² are each independently selected from a single bond, —O—, —CO—, —S—, —SO ₂ —, —NH— and —CH ₂ —. Among them, —O—, —CO—, —S—, —SO ₂ —, —NH— is preferable, and —O—, —S— is easy to synthesize. From the viewpoint of

In the general formula (O-1), L ¹ represents a divalent linking group, each of which may contain a heteroatom and a substituent, may be a divalent aliphatic group having 1 to 20 carbon atoms, a divalent A alicyclic group having 3 to 20 carbon atoms, a divalent aromatic group having 5 to 15 carbon atoms, or a combination thereof is preferable, and a divalent aliphatic group having 1 to 20 carbon atoms is preferable. More preferred.

Examples of the divalent aliphatic group represented by L ¹ include an alkylene group having 1 to 20 carbon atoms. Examples of the alkylene group having 1 to 20 carbon atoms 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. Of these, a methylene group, an ethylene group and a propylene group are more preferred, and an ethylene group is particularly preferred. 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 divalent alicyclic group represented by L ¹ include a cycloalkylene group having 3 to 20 carbon atoms. Examples of the cycloalkylene group having 3 to 20 carbon atoms include cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cycloheptylene group, cyclooctylene group, cyclononylene group, cyclodecylene group, cyclododecylene group, and cyclohexadecylene. 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.

Examples of the divalent aromatic group represented by L ¹ include an arylene group having 5 to 15 carbon atoms, which includes a hetero atom and may have a heterocyclic structure. Examples of the arylene group having 5 to 15 carbon atoms include a phenylene group and a naphthalenediyl 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 general formula (O-1), the number of atoms in the cyclic structure containing a carbodiimide group 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 containing a carbodiimide group means the number of atoms that directly constitute the cyclic structure containing a carbodiimide group. For example, if it is an 8-membered ring, it is 50; It is. 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, in the general formula (O-1), the number of atoms in the cyclic structure is preferably 10 to 30, more preferably 10 to 20, and particularly preferably 10 to 15.

Next, the cyclic carbodiimide compound represented by the general formula (O-2) will be described.

In general formula (O-2), R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ each independently represents an alkyl group, an aryl group or an alkoxy group. R ¹² to R ¹⁴ , R ¹⁶ to R ¹⁸ , R ²² to R ²⁴ and R ²⁶ to R ²⁸ each independently represent a hydrogen atom, an alkyl group, an aryl group or an alkoxy group. R ¹¹ to R ²⁸ may combine with each other to form a ring. X ¹¹ , X ¹² , X ²¹ and X ²² each independently represent a single bond, —O—, —CO—, —S—, —SO ₂ —, —NH— or —CH ₂ —. L ² represents a tetravalent linking group.

In the general formula (O-2), preferred ranges of R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ are the same as the preferred ranges of R ¹ and R ^{5 in} the general formula (O-1).
In the aryl group represented by R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ , R ¹¹ and R ¹² are condensed, R ¹⁵ and R ¹⁶ are condensed, R ²¹ and R ²² are condensed, or R ²⁵ and R ²⁶ are condensed. Although it may be an aryl group formed, it is preferred that R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ do not form a ring by condensing with R ¹² , R ¹⁶ , R ²² and R ²⁶ , respectively.
R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ may be the same or different, but are preferably the same from the viewpoint of cost.

In the general formula (O-2), preferred ranges of R ¹² to R ¹⁴ , R ¹⁶ to R ¹⁸ , R ²² to R ²⁴ and R ²⁶ to R ²⁸ are R ² in the general formula (O-1). This is the same as the preferred range of ~ R ⁴ and R ⁶ ~ R ⁸ .
Among R ¹² to R ¹⁴ , R ¹⁶ to R ¹⁸ , R ²² to R ^24, and R ²⁶ to R ²⁸ , R ¹² , R ¹⁶ , R ^22, and R ²⁶ are all hydrogen atoms, R ¹¹ , R ¹⁵ , R ²¹ and R ²⁵ are preferable from the viewpoint of easy introduction of bulky substituents.

Thus, by introducing a bulky group such as an alkyl group, an aryl group or an alkoxy group in the vicinity of the carbodiimide group, an isocyanate group and a terminal hydroxyl group of the polyester produced after the reaction of the carbodiimide group and the terminal carboxylic acid of the polyester. Can be suppressed. As a result, high molecular weight of the polyester can be suppressed, and generation of chips due to the increase in the viscosity of the polyester as described above can be suppressed.

In the general formula (O-2), R ¹¹ to R ²⁸ may be bonded to each other to form a ring. A preferable ring range is the above general formula (O-1) in which R ¹ to R ⁸ are This is the same as the range of the ring formed by bonding.

In the general formula (O-2), preferred ranges of X ¹¹ , X ¹² , X ²¹ and X ²² are the same as the preferred ranges of X ¹ and X ^{2 in} the general formula (O-1).

In the general formula (O-2), L ² represents a tetravalent linking group, each of which may contain a heteroatom and a substituent, a tetravalent aliphatic group having 1 to 20 carbon atoms, a tetravalent It is preferably an alicyclic group having 3 to 20 carbon atoms, a tetravalent aromatic group having 5 to 15 carbon atoms, or a combination thereof, and is preferably a tetravalent aliphatic group having 1 to 20 carbon atoms. More preferred.

Examples of the tetravalent aliphatic group represented by L ² include an alkanetetrayl group having 1 to 20 carbon atoms. As an alkanetetrayl group having 1 to 20 carbon atoms, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group Group, nonanetetrayl group, decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like, methanetetrayl group, ethanetetrayl group, propanetetrayl group are more preferable, and ethanetetrayl group is particularly preferable preferable. These aliphatic groups may contain a substituent. 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 tetravalent alicyclic group represented by L ² include a cycloalkanetetrayl group having 3 to 20 carbon atoms as the alicyclic group. As the cycloalkanetetrayl group having 3 to 20 carbon atoms, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group Yl group, cyclodecanetetrayl group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may contain a substituent. Examples of the substituent include 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, an ester group, an ether group, and an aldehyde group.

Examples of the tetravalent aromatic group represented by L ² include an arenetetrayl group having 5 to 15 carbon atoms, which may include a hetero atom and have a heterocyclic structure. Examples of the arenetetrayl group (tetravalent) having 5 to 15 carbon atoms 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 general formula (O-2), two cyclic structures containing a carbodiimide group are included via L ² which is a tetravalent linking group.
The preferred range of the number of atoms in the cyclic structure containing each carbodiimide group in the general formula (O-2) is the preferred range of the number of atoms in the cyclic structure containing the carbodiimide group in the general formula (O-1). It is the same.

The cyclic carbodiimide compound of the present invention is an aromatic carbodiimide having no ring structure in which the first nitrogen and the second nitrogen of two or more carbodiimide groups are bonded by a linking group in the molecule. The carbodiimide compound is monocyclic and is preferably represented by the above general formula (O-1) from the viewpoint of difficulty in increasing the viscosity.
However, from the viewpoint of suppressing volatilization and suppressing generation of isocyanate gas during production, the cyclic carbodiimide compound of the present invention preferably has a plurality of cyclic structures and is represented by the general formula (O-2). .

It is preferable for the cyclic carbodiimide compound used in the present invention to have a molecular weight of 400 or more because volatility is small and generation of isocyanate gas during production can be suppressed. Further, the upper limit of the molecular weight of the cyclic carbodiimide compound is not particularly limited as long as the effects of the present invention are not impaired, but 1500 or less is preferable from the viewpoint of reactivity with carboxylic acid.
The molecular weight of the cyclic carbodiimide compound used in the present invention is more preferably 500 to 1200.

Specific examples of the cyclic carbodiimide compound represented by the general formula (O-1) or (O-2), that is, specific examples of the cyclic carbodiimide compound of the present invention include the following compounds: It is done. However, the present invention is not limited to the following specific examples.

The cyclic carbodiimide compound of the present invention is a compound having at least one structure (carbodiimide group) represented by —N═C═N— adjacent to an aromatic ring. For example, in the presence of a suitable catalyst, The organic isocyanate can be heated to produce a decarboxylation reaction. Further, the cyclic carbodiimide compound of the present invention can be synthesized with reference to the method described in JP2011-256337A.
In synthesizing the cyclic carbodiimide compound of the present invention, there is no particular limitation as a method for introducing a specific bulky substituent into the ortho position of the arylene group adjacent to the first nitrogen and the second nitrogen of the carbodiimide group. By nitrating alkylbenzene by the method, nitrobenzene substituted with an alkyl group can be synthesized, and based on this, cyclic carbodiimide can be synthesized by the method described in WO2011 / 158958.

The cyclic carbodiimide compound is preferably contained in an amount of 0.1 to 5% by mass, more preferably 0.2 to 3% by mass, and more preferably 0.3 to 2% by mass with respect to the aromatic polyester. More preferably, it is contained. By making the content rate of a cyclic carbodiimide compound in the said range, the viscosity of a polyester film can be made into an appropriate range, and generation | occurrence | production of cutting waste can be suppressed at the time of cutting.

(Ketene imine compound)
The aromatic polyester film of the present invention contains a ketene imine compound. The ketene imine compound may be used alone or in combination with the cyclic carbodiimide compound.
As the ketene imine compound, a ketene imine compound represented by the following general formula (1) is preferably used. Hereinafter, the ketene imine compound represented by the following general formula (1) will be described.

Here, in the general formula (1), R ₁ and R ₂ each independently represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. , R ₃ represents an alkyl group or an aryl group.

The molecular weight of the portion excluding the nitrogen atom constituting the ketene imine of the ketene imine compound and the substituent bonded to the nitrogen atom is preferably 320 or more. That is, in the general formula (1), the molecular weight of the R ₁ —C (═C) —R ₂ group is preferably 320 or more.

The alkyl group represented by R ₁ and R ₂ is preferably an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms. The alkyl group represented by R ₁ and R ₂ may be linear, branched or cyclic. Examples of the alkyl group represented by R ₁ and R ₂ include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, tert-butyl group, sec-butyl group, iso-butyl group, n- Examples include pentyl group, sec-pentyl group, iso-pentyl group, n-hexyl group, sec-hexyl group, iso-hexyl group, cyclohexyl group and the like. Of these, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an iso-butyl group, and a cyclohexyl group are more preferable.
The alkyl group represented by R ₁ and R ₂ may further have a substituent. Unless the reactivity of a ketene imine group and a carboxyl group is lowered, the substituent is not particularly limited, and the above substituents can be exemplified similarly. The number of carbon atoms of the alkyl group represented by R ₁ and R ₂ indicate the number of carbon that does not contain a substituent group.

The aryl group represented by R ₁ and R ₂ is preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of the aryl group represented by R ₁ and R ₂ include a phenyl group and a naphthyl group, and among them, a phenyl group is particularly preferable.
The aryl group includes a heteroaryl group. The heteroaryl group refers to a group in which at least one of the ring-constituting atoms of a 5-membered, 6-membered or 7-membered ring exhibiting aromaticity or its condensed ring is substituted with a heteroatom. Examples of the heteroaryl group include imidazolyl group, pyridyl group, quinolyl group, furyl group, thienyl group, benzoxazolyl group, indolyl group, benzimidazolyl group, benzthiazolyl group, carbazolyl group, and azepinyl group. . The hetero atom contained in the heteroaryl group is preferably an oxygen atom, a sulfur atom, or a nitrogen atom, and particularly preferably an oxygen atom or a nitrogen atom.
The aryl group or heteroaryl group represented by R ₁ and R ₂ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered. Incidentally, the number of carbon atoms of the aryl or heteroaryl group represented by R ₁ and R ₂ indicate the number of carbon that does not contain a substituent group.

The alkoxy group represented by R ₁ and R ₂ is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and an alkoxy group having 2 to 6 carbon atoms. It is particularly preferred that The alkoxy group represented by R ₁ and R ₂ may be linear, branched or cyclic. Preferable examples of the alkoxy group represented by R ₁ and R ₂ include a group in which —O— is linked to the terminal of the alkyl group represented by R ₁ and R ₂ . The alkoxy group represented by R ₁ and R ₂ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered. The number of carbon atoms of the alkoxy group represented by R ₁ and R ₂ may indicate the number of carbon that does not contain a substituent group.

The alkoxycarbonyl group represented by R ₁ and R ₂ is preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, more preferably an alkoxycarbonyl group having 2 to 12 carbon atoms, and 2 to 6 carbon atoms. Particularly preferred is an alkoxycarbonyl group. Examples of the alkoxy moiety of the alkoxycarbonyl group represented by R ₁ and R ₂ include the examples of the alkoxy group described above.

The aminocarbonyl group represented by R ₁ and R ₂ is preferably an alkylaminocarbonyl group having 1 to 20 carbon atoms or an arylaminocarbonyl group having 6 to 20 carbon atoms. Preferable examples of the alkylamino part of the alkylaminocarbonyl group include groups in which —NH— is linked to the terminal of the alkyl group represented by R ₁ and R ₂ . The alkylaminocarbonyl group represented by R ₁ and R ₂ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered.
Preferable examples of the arylamino moiety of the arylaminocarbonyl group having 6 to 20 carbon atoms include a group in which —NH— is linked to the terminal of the aryl group represented by R ₁ and R ₂ . Examples of the aryl moiety of the arylaminocarbonyl group represented by R ₁ and R ₂ include the examples of the aryl group or heteroaryl group described above. The arylaminocarbonyl group represented by R ₁ and R ₂ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered. The number of carbon atoms in the alkyl amino group represented by R ₁ and R ₂ indicate the number of carbon that does not contain a substituent group.

The aryloxy group represented by R ₁ and R ₂ is preferably an aryloxy group having 6 to 20 carbon atoms, and more preferably an aryloxy group having 6 to 12 carbon atoms. Examples of the aryl part of the aryloxy group represented by R ₁ and R ₂ include the examples of the aryl group or heteroaryl group described above.

The acyl group represented by R ₁ and R ₂ is preferably an acyl group having 2 to 20 carbon atoms, more preferably an acyl group having 2 to 12 carbon atoms, and an acyl group having 2 to 6 carbon atoms. It is particularly preferred that The acyl group represented by R ₁ and R ₂ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered. The number of carbon atoms in the acyl group represented by R ₁ and R ₂ may indicate the number of carbon that does not contain a substituent group.

Aryloxycarbonyl group represented by R ₁ and R ₂ is preferably an aryloxycarbonyl group having 7 to 20 carbon atoms, more preferably R ₁ and be an aryloxycarbonyl group having 7 to 12 carbon atoms Examples of the aryl moiety of the aryloxycarbonyl group represented by R ₂ include the examples of the aryl group or heteroaryl group described above.

R ₃ represents an alkyl group or an aryl group. The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms. The alkyl group represented by R ₃ may be linear, branched or cyclic. Examples of the alkyl group represented by R ₃ include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, tert-butyl group, sec-butyl group, iso-butyl group, n-pentyl group, Examples thereof include a sec-pentyl group, an iso-pentyl group, an n-hexyl group, a sec-hexyl group, an iso-hexyl group, and a cyclohexyl group. Of these, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and a cyclohexyl group are more preferable.
The alkyl group represented by R ₃ may further have a substituent. Unless the reactivity of a ketene imine group and a carboxyl group is lowered, the substituent is not particularly limited, and the above substituents can be exemplified similarly.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of the aryl group represented by R ₃ include a phenyl group and a naphthyl group, and among them, a phenyl group is particularly preferable.

The aryl group includes a heteroaryl group. The heteroaryl group refers to a group in which at least one of the ring-constituting atoms of a 5-membered, 6-membered or 7-membered ring exhibiting aromaticity or its condensed ring is substituted with a heteroatom. Examples of the heteroaryl group include imidazolyl group, pyridyl group, quinolyl group, furyl group, thienyl group, benzoxazolyl group, indolyl group, benzimidazolyl group, benzthiazolyl group, carbazolyl group, and azepinyl group. . The hetero atom contained in the heteroaryl group is preferably an oxygen atom, a sulfur atom, or a nitrogen atom, and particularly preferably an oxygen atom or a nitrogen atom.
The aryl group or heteroaryl group represented by R ₃ may further have a substituent, and the substituent is not particularly limited as long as the reactivity between the ketene imine group and the carboxyl group is not lowered.

In addition, General formula (1) may contain the repeating unit. In this case, at least one of R _{1 and} R ₃ is a repeating unit, and this repeating unit preferably includes a ketene imine moiety.

Further, as the ketene imine compound, it is preferable to use a ketene imine compound represented by the following general formula (2). Hereinafter, the ketene imine compound represented by the following general formula (2) will be described.

Here, in the general formula (2), R ₁ represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ represents an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group having L ₁ as a substituent. R ₃ represents an alkyl group or an aryl group. n represents an integer of 1 to 4, and L ₁ represents an n-valent linking group. The molecular weight of the (R ₁ —C (═C) —R ₂ —) nL ₁ group is preferably 320 or more.

In General Formula (2), R ₁ is the same as that in General Formula (1), and the preferred range is also the same.

In general formula (2), R ₂ is an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group having L ₁ which is an n-valent linking group. Represents. The alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group has the same meaning as that in formula (1), and the preferred range is also the same.

In general formula (2), R ₃ is the same as that in general formula (1), and the preferred range is also the same.

L ₁ represents an n-valent linking group, where n represents an integer of 1 to 4. Among these, n is preferably 2 to 4.
Specific examples of the divalent linking group include, for example, —NR ₈ — (R ₈ represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, A hydrogen atom is preferred), —SO ₂ —, —CO—, a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, an alkynylene group, a substituted or unsubstituted phenylene group, substituted or unsubstituted Examples thereof include a substituted biphenylene group, a substituted or unsubstituted naphthylene group, —O—, —S— and —SO—, and a group obtained by combining two or more thereof.
Specific examples of the trivalent linking group include a group obtained by removing one hydrogen atom from those having a substituent among the linking groups mentioned as examples of the divalent linking group.
Specific examples of the tetravalent linking group include, for example, a group obtained by removing two hydrogen atoms from those having a substituent among the linking groups mentioned as examples of the divalent linking group.

In the present invention, by setting n to 2 to 4, a compound having two or more ketene imine moieties in one molecule can be obtained, and a more excellent end-capping effect can be exhibited. Further, by using a compound having two or more ketene imine moieties in one molecule, the molecular weight per ketene imine group can be lowered, and the ketene imine compound and the terminal carboxyl group of the polyester can be reacted efficiently. Furthermore, it can suppress that a ketene imine compound and a ketene compound volatilize by having two or more ketene imine parts in 1 molecule.

In general formula (2), n is more preferably 3 or 4. By setting n to 3 or 4, a compound having 3 or 4 ketene imine moieties in one molecule can be obtained, and a more excellent end-capping effect can be exhibited. Also, by placing the n 3 or 4, even when the molar molecular weight of the substituents R ₁ or R ₂ in the general formula (2) in the small, it is possible to suppress the volatilization of keteneimines compound.

As the ketene imine compound, a ketene imine compound represented by the following general formula (3) is preferably used. Hereinafter, the ketene imine compound represented by the following general formula (3) will be described.

In general formula (3), R ₁ and R ₅ represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R ₂ and R ₄ represent an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group having L ₂ as a substituent. R ₃ and R ₆ represent an alkyl group or an aryl group. L ₂ represents a single bond or a divalent linking group. The molecular weight of the R ₁ —C (═C) —R ₂ —L ₂ —R ₄ —C (═C) —R ₅ group is preferably 320 or more.

In General Formula (3), R ₁ is the same as that in General Formula (1), and the preferred range is also the same. R ₅ is the same as R ₁ in the general formula (1), and the preferred range is also the same.

In general formula (3), R ₂ is the same as that in general formula (2), and the preferred range is also the same. R ₄ is the same as R ₂ in the general formula (2), and the preferred range is also the same.

In general formula (3), R ₃ is the same as that in general formula (1), and the preferred range is also the same. R ₆ is the same as R ₃ in the general formula (1), and the preferred range is also the same.

In General Formula (3), L ₂ represents a single bond or a divalent linking group. Specific examples of the divalent linking group include the linking groups exemplified for L ₁ in formula (2).

In the present invention, the molecular weight of the portion excluding the nitrogen atom constituting the ketene imine of the ketene imine compound and the substituent bonded to the nitrogen atom is preferably 320 or more. The molecular weight of the ketene imine compound excluding the nitrogen atom constituting the ketene imine and the substituent bonded to the nitrogen atom may be 320 or more, preferably 400 or more, and more preferably 500 or more. The molar molecular weight of the ketene imine compound relative to the number of ketene imine moieties in one molecule (mole molecular weight / number of ketene imine moieties) is preferably 1000 or less, more preferably 500 or less, and preferably 400 or less. Further preferred. In the present invention, by controlling the molecular weight of the substituent on the ketene imine carbon of the ketene imine compound and the molar molecular weight of the ketene imine compound relative to the number of ketene imine moieties within the above range, the volatilization of the ketene imine compound itself is suppressed, and the terminal carboxyl group of the polyester Volatilization of the ketene compound that occurs when sealing is suppressed, and the terminal carboxyl group of the polyester can be sealed with a low addition amount of ketene imine compound.

The ketene imine compound of the present invention is a compound having at least one ketene imine group, and is synthesized with reference to, for example, the methods described in J. 方法 Am. Chem. Soc., 1953, 75 (3), pp 657-660. be able to.

Although the preferable specific example of General formula (1) is shown below, this invention is not limited to this.

As shown in the above exemplary compounds, in the present invention, the ketene imine compound is more preferably trifunctional or tetrafunctional. Thereby, the terminal sealing effect can be improved more and volatilization of a ketene imine compound and a ketene compound can be suppressed effectively. Also, if having a cyclic structure keteneimines portion as a ring skeleton as exemplified compound (6), R ₁ and R ₃ form a cyclic structure linked, R ₃ is alkylene or arylene group ring skeleton Become. In this case, R ₁ has a linking group containing a ketene imine moiety.
Illustrative compound (10) represents a repeating unit having a repeating number n, and n represents an integer of 3 or more. The left end shown in exemplary compound (10) is a hydrogen atom, and the right end is a phenyl group.

The ketene imine compound is preferably contained in an amount of 0.1 to 5% by weight, more preferably 0.2 to 3% by weight, and more preferably 0.3 to 2% by weight, based on the aromatic polyester. More preferably. By making the content rate of a ketene imine compound in the said range, generation | occurrence | production of cutting waste can be suppressed at the time of cutting.
In addition, when a ketene imine compound and a cyclic carbodiimide compound are used together, it is preferable that the sum total of the content rate of two types of compounds exists in the said range.

(Aromatic polyester film)
The aromatic polyester film of the present invention contains an aromatic polyester resin, fine particles, a cyclic carbodiimide compound, or a ketene imine compound. In addition, only one of the cyclic carbodiimide compound or the ketene imine compound may be included, or both of them may be included.

The terminal carboxyl group content in the aromatic polyester film (the carboxylic acid value of the aromatic polyester, hereinafter also referred to as AV) is 0 to 30 eq / ton, more preferably 1 to 20 eq / ton, still more preferably 3 to 15 eq / ton. It is. The intrinsic viscosity (hereinafter also referred to as IV) is preferably 0.6 to 1.2 dl / g, more preferably 0.65 to 1 dl / g, and still more preferably 0.7 to 0.85 dl / g. By setting AV and IV within the above ranges, it is possible to suppress hydrolysis and lower molecular weight during the thermotest, and it is possible to suppress generation of chips (cutting scraps) after the thermotest. Further, by setting IV within the above range, film uniformity can be enhanced in addition to hydrolysis resistance. By setting AV within the above range, the heat resistance can be improved, and the decrease in strength over time of wet heat can be suppressed. Furthermore, when the AV is within the above range, the adhesion between the layers can be enhanced when the films are laminated. On the other hand, if the IV exceeds this range and the molecular weight is excessively increased, the entanglement between the molecules becomes too large, and the elongation at break tends to be lowered and it tends to become brittle. In this case, chips are easily generated, which is not preferable. In addition, these IV and AV values indicate measured values with an aromatic polyester film.

The aromatic polyester film is preferably subjected to solid phase polymerization after polymerization. Specifically, after the polymerized resin is dried and crystallized, it is 180 to 230 ° C., more preferably 190 to 220 ° C., more preferably 195 to 215 ° C., for 5 to 50 hours, more preferably 10 to 40 hours. More preferably, the heat treatment is performed in an inert gas stream (nitrogen or the like) or in a vacuum for 15 to 35 hours. As a result, AV and IV within the above ranges can be achieved, and low AV and high IV can be achieved.

Also, the aromatic polyester film can achieve AV and IV within the above ranges by adding a terminal blocking agent such as the above-mentioned cyclic carbodiimide compound or ketene imine compound. The terminal blocking agent lowers AV by reacting with the terminal carboxylic acid of the aromatic polyester. Furthermore, IV can be raised by the reaction of the carbodiimide group or ketene imine group with the terminal carboxylic acid and the generated isocyanate group with the terminal hydroxyl group of another aromatic polyester. In addition, a terminal blocker may be added at the time of master pellet preparation, and may be added at the extrusion process in a film forming process.

The molecular weight of the aromatic polyester film of the present invention is preferably a weight average molecular weight (Mw) of 35,000 to 125,000, more preferably 50,000 to 90,000, and more preferably 60000 to 80,000 from the viewpoints of heat resistance and viscosity. Is particularly preferred. As the weight average molecular weight, a value in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent can be used.

The thickness of the aromatic polyester film of the present invention varies depending on the application, but when used as a member for a solar cell module backsheet, it is preferably 25 to 300 μm, more preferably 120 to 300 μm. By setting the thickness to the above lower limit or higher, sufficient mechanical strength can be obtained, and by setting the thickness to the upper limit or lower, a merit in cost can be obtained.

The aromatic polyester film of the present invention is preferably stretched, more preferably biaxially stretched, particularly preferably planar biaxially stretched as compared with stretching such as tubular, and the like. It is particularly preferable that the film is axially stretched. The longitudinal (MD) orientation and transverse (TD) orientation of the polyester film of the present invention are each preferably 0.14 or more, more preferably 0.155 or more, and particularly preferably 0.16 or more. When the degree of orientation is equal to or greater than the above lower limit, the restraint property of the amorphous chain is improved (the mobility is lowered), and the hydrolysis resistance is improved. MD and TD orientation degrees were measured using x, y, and biaxially oriented films in an atmosphere of 25 ° C. using an Abbe refractometer, a monochromatic light sodium D-line as a light source, and methylene iodide as a mounting liquid. The refractive index in the z direction is measured, and can be calculated from MD orientation degree: Δn (x−z), TD; Δn (yz).

(Laminated film)
The present invention relates to a laminated film in which at least one aromatic polyester film containing the above-mentioned fine particles and a cyclic carbodiimide compound or a ketene imine compound is contained, and a plurality of layers are laminated. The number of laminated films is preferably 2 to 8 layers, more preferably 2 to 5 layers, and more preferably 2 to 3 layers. The laminated film only needs to include at least one layer of the above-described aromatic polyester film, but more preferably, layers having different fine particle contents are laminated. As described above, the light reflectance can be more effectively increased by using the laminated structure. Furthermore, by laminating layers having different fine particle contents, the thermal expansion coefficients between adjacent layers can be made different. Thereby, curvature (warp) slightly occurs in each layer of the laminated film. Since the curvature generated in the laminated film functions to absorb the impact at the time of cutting, generation of cutting waste can be effectively suppressed.
By setting the number of layers laminated on the laminated film to be equal to or more than the above lower limit value, it is possible to generate curvature in each layer of the laminated film. Moreover, the film thickness of a laminated | multilayer film and the film thickness of each layer can be restrained in a suitable range by making the number of lamination | stacking below into the said upper limit.

The variation rate of the thickness of the thickest layer in the laminated film is 1 to 10%, preferably 1.5 to 8%. More preferably, it is 2 to 6%. By varying the thickness so as to be within the above range, the contact length between the layers can be increased, and the adhesion between the layers can be improved. Thereby, it can suppress that an interlayer peels at the time of a cutting | judgement and a cutting | judgement waste is generated from there. If the variation rate of thickness is less than the above range, this effect cannot be manifested and chips are likely to be generated. It becomes difficult to cut and the cutting waste tends to increase.
In addition, the thickness of a layer can be calculated | required by carrying out SEM observation of the cross section in MD and TD direction, and measuring the thickness of each layer 10 points | pieces for every 1 cm. As a result of 10-point measurement, the difference between the maximum value and the minimum value divided by the average value and expressed as a percentage is the thickness variation rate. In the present invention, the variation rate of thickness is determined for each MD and TD, and the average value is calculated.

Each layer constituting the laminated film is formed by coextrusion. The resin (melt) extruded from the co-extruder is passed through a filter and a gear pump as necessary, and is supplied to a lamination die. The variation rate of the thickness can be formed by giving a temperature distribution of 1 to 10 ° C., preferably 1.5 to 8 ° C., more preferably 2 to 7 ° C. inside the lamination die. By providing the temperature distribution within the above range, the layer can have a thickness variation rate. Thereby, generation | occurrence | production of cutting waste can be suppressed more effectively.
When temperature distribution is given inside the lamination die, the fluidity (viscoelasticity) of the melt changes, and subtle flow unevenness is formed. Since the melt flow in the die is established by a delicate balance of viscoelasticity of each layer, uneven thickness of the layer is formed as a result.

The temperature distribution inside the lamination die may be performed in either the longitudinal direction or the width direction, but it is more preferable that the temperature distribution is applied to both. Thereby, it becomes easier to form the variation rate of the thickness of the layer within the above range.
In addition, the period for giving the temperature distribution is preferably 1 to 30 cm, more preferably 2 to 25 cm, and still more preferably 3 to 20 cm for both MD and TD. Below this range, the thickness variation pitch tends to be too fine, and beyond this range, the thickness variation pitch is too large, making it difficult to form an effective “warp”.

As a method of providing the temperature distribution inside the stacking die, there is a method of providing a heater divided in the longitudinal direction and the width direction and controlling these temperatures. Moreover, a temperature distribution can also be provided by attaching a cooling plate to a location where the temperature of the die is desired to be lowered and cooling.

(Method for producing aromatic polyester film)
The method for producing an aromatic polyester film of the present invention includes a step of preparing a master pellet in which an aromatic polyester resin and fine particles are kneaded to disperse the fine particles in a high concentration, and the master pellet and the aromatic polyester pellet are mixed and extruded. And a step of casting from a die onto a cooling drum to form a film. At least one of the step of preparing a master pellet or the step of forming a film includes a step of mixing a cyclic carbodiimide compound or a ketene imine compound. The step of preparing the master pellet includes a step of kneading the aromatic polyester resin and the fine particles with the screw rotation torque, and the screw rotation torque is given a fluctuation of 0.1 to 10%.

(Process for preparing master pellets)
The aromatic polyester resin used for preparing the master pellet is preferably processed into a pellet after polycondensation of diol and dicarboxylic acid according to a conventional method. The dried fine particles, terminal blocker (cyclic carbodiimide compound or ketene imine compound), and aromatic polyester are kneaded to prepare master pellets in which fine particles are dispersed at a high concentration.

Drying is performed by drying a composition such as fine particles, end-capping agent, and aromatic polyester resin in vacuum or hot air so that the water content is 100 ppm or less, more preferably 80 ppm or less, and even more preferably 60 ppm or less. . The drying temperature at this time is preferably 80 to 200 ° C., more preferably 100 to 180 ° C., and further preferably 110 to 170 ° C. The drying time can be appropriately adjusted so as to achieve the above moisture content.

For kneading, various kneaders such as a single screw extruder, a twin screw extruder, a Banbury mixer, and a Brabender can be used. Among these, it is preferable to use a twin screw extruder. The kneading temperature is preferably from the crystal melting temperature (Tm) of the polyester resin to Tm + 80 ° C., more preferably Tm + 10 to Tm + 70 ° C., and further preferably Tm + 20 to Tm + 60 ° C. The kneading atmosphere may be any of air, vacuum, and inert gas flow, but more preferably vacuum and inert gas flow. The kneading time is 1 to 20 minutes, more preferably 2 to 18 minutes, and further preferably 3 to 15 minutes.

In the present invention, it is preferable to use a twin screw extruder for kneading. FIG. 1 schematically shows a configuration example of a twin-screw extruder that can be used in carrying out the method for producing an aromatic polyester film according to the present invention. When producing a polyester film by the melt extrusion method, generally used extruders are roughly classified into single-shaft and multi-shaft. As multi-shaft, a twin-screw extruder (two twin-screw extruder) is widely used. ing.
In the present invention, a barrel 10 having a supply port 12 and an extruder outlet 14, two screws 20 A and 20 B that rotate in the barrel 10, and a temperature that is arranged around the barrel 10 and controls the temperature in the barrel 10. A twin screw extruder 100 provided with the control means 30 can be used.
The barrel 10 may be provided with

vents

16A and 16B for drawing a vacuum. By providing the vents 16 A and 16 B at a plurality of locations, it is possible to control the raw material moisture content and the like.

Two screws 20 A and 20 B that are rotated by a drive motor 21 are provided in the barrel 10. From the viewpoint of mass production, the screw diameter is preferably 140 mm or more, more preferably 150 mm or more, and further preferably 160 to 200 mm.
The twin-screw extruder 100 is roughly divided into a meshing type and a non-meshing type of the two

screws

20A and 20B, and the meshing type has a larger kneading effect than the non-meshing type. In the present invention, any of a meshing type and a non-meshing type may be used, but a meshing type is preferably used from the viewpoint of suppressing kneading by sufficiently kneading the raw material resin.
Further, the rotation directions of the two

screws

20A and 20B are also divided into the same direction and different directions, respectively. The different-

direction rotating screws

20A and 20B have a higher kneading effect than the same-direction rotating type, and the same-direction rotating type has a self-cleaning effect, and thus is effective for preventing retention in the extruder. Furthermore, the axial direction is also parallel and oblique, and there is also a conical type shape used when applying strong shear.

In the twin screw extruder 100 that can be used in the present invention, screw segments of various shapes are used. As the shape of the screws 20 A and 20 B, for example, a full flight screw provided with a single spiral flight 22 having an equal pitch is used. As shown in FIG. 1, the screws 20 A and 20 B can be provided with kneading portions 24 A and 24 B that promote melting of the raw material resin in the vicinity of the vents 16 A and 16 B.

In the latter half of the twin-screw extruder 100, a temperature control zone (cooling part) for cooling the molten resin may be provided. By providing the screw 28 with a short pitch in the temperature control zone (cooling section), the resin moving speed of the wall surface of the barrel 10 is increased, and the temperature control efficiency can be increased.

At this time, it is preferable to apply torque fluctuations to the

screws

20A and 20B. Specifically, it is preferable to give a fluctuation of 0.1 to 10%, preferably 0.2 to 5%, more preferably 0.3 to 3% to the rotational torque of the

screws

20A and 20B.
The torque fluctuation of the screw as described above may be continuously and constantly applied, but it is preferably applied 1 time / minute to 100 times / minute, more preferably 3 times / minute to 80 times / minute. It is more preferable to apply 5 times / minute to 60 times / minute. Such torque fluctuation can be achieved by changing the power supplied to the motor that rotates the screw. By varying the current value supplied to the screw drive motor of the extruder by computer control, a desired screw number and torque fluctuation rate can be obtained.

The kneaded resin is extruded into strands, cooled and solidified in air or water, and then cut into pellets.

The additive concentration of the particles and the end-capping agent in the master pellet is preferably 1.5 to 20 times, more preferably 2 to 15 times, and further preferably 3 to 10 times the concentration used in the film. The reason why the additive concentration is made higher than the target concentration is that the target concentration is obtained by diluting with the aromatic polyester pellets in the next film-forming step.

(Film forming process)
Similarly to the polyester resin, the master pellet is also dried so that the moisture content is 100 ppm or less, more preferably 80 ppm or less, and still more preferably 60 ppm or less. The obtained master pellets and aromatic polyester pellets are mixed, put into a single or twin screw extruder, and melt extruded.

The melting temperature is preferably from the crystal melting temperature (Tm) of the polyester resin to Tm + 80 ° C., more preferably Tm + 10 to Tm + 70 ° C., and further preferably Tm + 20 to Tm + 60 ° C. The kneading atmosphere may be any of air, vacuum, and inert gas flow, but more preferably vacuum and inert gas flow.

The extruded molten resin (melt) is preferably passed through a melt pipe, a gear pump, and a filter. The opening of the filter is preferably 1 to 50 μm, more preferably 5 to 40 μm, and still more preferably 10 to 30 μm. It is also preferable to provide a static mixer in the melt pipe to promote mixing of the resin and the additive.

In the case of lamination (coextrusion), the above melt extrusion is performed for each type of resin. In the case of stacking, the combination of layers to be stacked is not particularly limited, and examples thereof include the following combinations.
1) Combination of fine particle layer and transparent layer (layer not containing fine particles and voids) 2) Combination of layers having different concentrations of fine particle layers 3) Combination of fine particle layer and void layer 4) Combination of void layer and transparent layer 5) Void 6) Combination of fine particle layer, void layer and transparent layer

The number of stacked layers is preferably 2 to 8 layers, more preferably 2 to 5 layers, and more preferably 2 to 3 layers. In the case of stacking a plurality of layers, for example, the following configuration can be adopted.
1) Layer with many fine particles / layer with few fine particles,
2) Fine particle layer / transparent layer 3) Layer with many fine particles / Transparent layer / Layer with few fine particles 4) Layer with many fine particles / Layer with few fine particles / Transparent layer 5) Transparent layer / fine particle layer / transparent layer 6) Many voids Layer / layer with less voids,
7) Void layer / transparent layer 8) Layer with many voids / transparent layer / layer with few voids 9) Layer with many voids / layer with few voids / transparent layer 10) Transparent layer / void layer / transparent layer

The molten resin (melt) is extruded onto a cooling roll through a die, and is cast and solidified. Thus, the obtained film turns into a cast film (unstretched original fabric).
When the layers are stacked, a multi-manifold die or a feed block die can be used as the die. Here, it is preferable to give a temperature distribution of 1 to 10 ° C., preferably 1.5 to 8 ° C., more preferably 2 to 7 ° C., inside the lamination die. By providing the temperature distribution within the above range, the layer can have a thickness variation rate. Thereby, generation | occurrence | production of cutting waste can be suppressed more effectively.
The period for giving the temperature distribution is preferably 1 to 30 cm, more preferably 2 to 25 cm, and still more preferably 3 to 20 cm for both MD and TD.

The temperature of the cooling drum is preferably 0 to 60 ° C, more preferably 5 to 55 ° C, and further preferably 10 to 50 ° C. At this time, in order to improve the adhesion between the melt and the cooling drum and improve the flatness, it is also preferable to use an electrostatic application method, an air knife method, water coating on the cooling drum, or the like. Further, in order to efficiently perform cooling, cold air may be blown from above the cooling drum.

(Stretching process)
The original fabric is preferably stretched at least once in the machine direction (MD) and the transverse direction (TD). In the case of stretching in the vertical and horizontal directions, they may be sequentially performed in the order of vertical → horizontal, horizontal → vertical, or may be simultaneously performed in two directions. Furthermore, it is also preferable to stretch in multiple stages, for example, vertical → vertical → horizontal, vertical → horizontal → vertical, vertical → horizontal → horizontal. You may apply | coat functional layers, such as an easily bonding layer and an antistatic layer, during such extending | stretching.

Longitudinal stretching can usually be achieved by setting two or more pairs of nip rolls and passing the heated raw fabric between them so that the peripheral speed of the outlet side nip roll is higher than that of the inlet side. At this time, it is preferable to provide a temperature difference between the front and back as described above.
Further, it is preferable to preheat the original fabric before longitudinal stretching. The preheating temperature is preferably Tg-50 to Tg + 30 ° C. of polyester, more preferably Tg-40 to Tg + 15 ° C., and further preferably Tg-30 to Tg. Such preheating may be brought into contact with a heating roll, a radiant heat source (IR heater, halogen heater, etc.) may be used, or hot air may be blown.
The longitudinal stretching is preferably performed at Tg−10 to Tg + 50 ° C., more preferably T to Tg + 40 ° C., and further preferably Tg + 10 to Tg + 35 ° C. The draw ratio is preferably 2 to 5 times, more preferably 2.5 to 4.5 times, still more preferably 3 to 4 times.

The film is preferably cooled after longitudinal stretching, preferably Tg-50 to Tg, more preferably Tg-45 to Tg-5 ° C, still more preferably Tg-40 to Tg-10 ° C. Such cooling may be brought into contact with a cooling roll or may be blown with cold air.

The transverse stretching is preferably performed using a tenter. That is, it can be performed by expanding the clip in the width direction while conveying the heat treatment zone while holding both ends of the polyester film with the clip.
The stretching temperature is preferably Tg to Tg + 100 ° C., more preferably Tg + 10 to Tg + 80 ° C., and further preferably Tg + 20 to Tg + 70 ° C. The draw ratio is preferably 2 to 5.5 times, more preferably 2.5 to 5 times, still more preferably 3 to 4.5 times.

In the stretching step, it is preferable to perform heat setting and relaxation after the stretching treatment and after heat treatment of the film.

The heat setting means that the film is subjected to heat treatment at about 180 to 210 ° C. (more preferably, 185 to 210 ° C.) for 1 to 60 seconds (more preferably 2 to 30 seconds). The heat setting is preferably carried out in the state of being gripped by the chuck in the tenter after the transverse stretching. In this case, the chuck interval is performed at the width at the end of the transverse stretching, further widened, or reduced in width. May be. By performing heat setting, microcrystals can be generated, and mechanical properties and durability can be improved.

It is preferable to perform relaxation treatment after heat fixation. The thermal relaxation treatment is a treatment for shrinking the film by applying heat to the film for stress relaxation. In the thermal relaxation treatment, relaxation is preferably performed in at least one of length and width, and the amount of relaxation is preferably 1 to 15% (ratio to the width after transverse stretching) in both length and width, more preferably 2 to 10%, and still more preferably. 3 to 8%. The relaxation temperature is preferably Tg + 50 to Tg + 180 ° C., more preferably Tg + 60 to Tg + 150 ° C., and further preferably Tg + 70 to Tg + 140 ° C.

Thermal relaxation is preferably performed at −100 to Tm−10 ° C., more preferably Tm−80 to Tm−20 ° C., and further preferably Tm−70 to Tm−35 ° C., where the melting point of the polyester is Tm. is there. This promotes the formation of crystals and improves the mechanical strength and heat shrinkability. Furthermore, hydrolysis resistance is improved by heat setting at Tm-35 ° C. or lower. This is to suppress the reactivity with water by increasing the tension (binding) without breaking the orientation of the amorphous part where hydrolysis is likely to occur.

Lateral relaxation can be performed by reducing the width of the tenter clip. Moreover, longitudinal relaxation can be implemented by narrowing the interval between adjacent clips of the tenter. This can be achieved by connecting adjacent clips in a pantograph shape and shrinking the pantograph. Moreover, after taking out from a tenter, it can also heat-process and relieve | moderate, conveying with low tension. Tension is preferably cross-sectional area per 0 ~ 0.8N / mm ² of film, more preferably 0 ~ 0.6N / mm ^2, more preferably from 0 ~ 0.4N / mm ^2. 0N / mm ² can be carried out by providing two or more pairs of nip rolls during conveyance and slacking them in a suspended manner (in a suspended form).

(Winding process)
The film coming out of the tenter is trimmed at both ends held by the clip, and subjected to knurling (embossing) at both ends, and then wound up. A preferable width is 0.8 to 10 m, more preferably 1 to 6 m, and still more preferably 1.5 to 4 m. The thickness is preferably 30 to 300 μm, more preferably 40 to 280 μm, still more preferably 45 to 260 μm. Such adjustment of the thickness can be achieved by adjusting the discharge amount of the extruder or adjusting the film forming speed (adjusting the speed of the cooling roll, the stretching speed linked to this).

As described above, the aromatic polyester film according to the present invention can be produced by the above-described method. As will be described later, the aromatic polyester film of the present invention can be suitably used not only as a protective sheet for solar cell modules (back sheet for solar cell modules) but also for other uses.
The film of the present invention, on which, COOH, OH, SO 3 _H, can also be used as a laminate having a coating layer comprising at least one functional group selected from NH ₂ and salts thereof.

(Back sheet for solar cell module)
The back sheet for a solar cell module of the present invention includes the above-described aromatic polyester film. When the aromatic polyester film of the present invention is used for a back sheet for a solar cell module, the problem that the back sheet is peeled off by cutting scraps is reduced, and in particular, adhesion between layers after wet heat aging can be greatly improved.

In the back sheet for a solar cell module of the present invention, for example, the following functional layer may be applied to a polyester film after uniaxial stretching and / or biaxial stretching. For coating, a known coating technique such as a roll coating method, a knife edge coating method, a gravure coating method, or a curtain coating method can be used.
In addition, surface treatment (flame treatment, corona treatment, plasma treatment, ultraviolet treatment, etc.) may be performed before the coating. Furthermore, it is also preferable to bond together using an adhesive.

<Easily adhesive layer>
The solar cell module of the present invention preferably has an easy-adhesive layer on the side facing the sealing material of the battery side substrate in which the solar cell element is sealed with the sealing material. Easy adhesion showing adhesion to an adherend containing a sealing material (especially ethylene-vinyl acetate copolymer) (for example, the surface of the sealing material of the battery side substrate in which the solar cell element is sealed with the sealing material). By providing the conductive layer, the back sheet and the sealing material can be firmly bonded. Specifically, it is preferable that the easily adhesive layer has an adhesive force of 10 N / cm or more, preferably 20 N / cm or more, particularly with EVA (ethylene-vinyl acetate copolymer) used as a sealing material.
Further, the easy-adhesion layer needs to prevent the backsheet from peeling off during use of the solar cell module, and therefore, the easy-adhesion layer desirably has high hydrolysis resistance. The easy-adhesion layer can contain a binder such as polyester, polyurethane, acrylic resin, and polyolefin, fine particles, a crosslinking agent, and an additive.

As a method for forming the easy-adhesion layer in the present invention, there are a method for pasting a polymer sheet having easy adhesion to a polyester film and a method by coating. Is preferable in that it can be formed. As a coating method, for example, a known method such as a gravure coater or a bar coater can be used. The solvent of the coating solution used for coating may be water or an organic solvent such as toluene or methyl ethyl ketone. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
Moreover, when forming an easily-adhesive layer by application | coating, it is preferable to combine the drying of an application layer and heat processing in the drying zone after heat processing. The same applies to the case where a colored layer and other functional layers described later are formed by coating.

The thickness of the easy-adhesive layer is not particularly limited, but is usually preferably 0.05 to 8 μm, more preferably 0.1 to 5 μm. When the thickness of the easy-adhesive layer is 0.05 μm or more, the required easy adhesion can be easily obtained, and when the thickness is 8 μm or less, the planar shape can be maintained better.
Moreover, it is preferable that the easily-adhesive layer in this invention has transparency.

<Colored layer>
The polyester film of the present invention can be provided with a colored layer. The colored layer is a layer arranged in contact with the surface of the polyester film or through another layer, and can be constituted using a pigment or a binder.

The first function of the colored layer is to increase the power generation efficiency of the solar cell module by reflecting the light that has reached the back sheet without being used for power generation in the solar cell out of the incident light and returning it to the solar cell. is there. The second function is to improve the decorativeness of the appearance when the solar cell module is viewed from the front side. In general, when a solar cell module is viewed from the front side, a back sheet can be seen around the solar cell, and the decorativeness can be improved by providing a colored layer on the back sheet.

Examples of the pigment include inorganic pigments such as titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, ultramarine blue, bitumen, and carbon black, and organic pigments such as phthalocyanine blue and phthalocyanine green. It is done. Among these pigments, a white pigment is preferable from the viewpoint of constituting a colored layer as a reflective layer that reflects incident sunlight. As the white pigment, for example, titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc and the like are preferable.

As a binder suitable for the colored layer, for example, polyester, polyurethane, acrylic resin, polyolefin, or the like can be used. From the viewpoint of durability, the binder is preferably an acrylic resin or a polyolefin. As the acrylic resin, a composite resin of acrylic and silicone is also preferable. Examples of preferred binders include the following.
Examples of the polyolefin include Chemipearl S-120 and S-75N (both manufactured by Mitsui Chemicals). Examples of the acrylic resin include Julimer ET-410 and SEK-301 (both manufactured by Nippon Pure Chemical Industries, Ltd.). Examples of the composite resin of acrylic and silicone include Ceranate WSA1060, WSA1070 (both manufactured by DIC Corporation), H7620, H7630, H7650 (both manufactured by Asahi Kasei Chemicals Corporation) and the like.

In addition to the binder and the pigment, a cross-linking agent, a surfactant, a filler, and the like may be further added to the colored layer in the present invention as necessary.

<Undercoat layer>
The polyester film of the present invention can be provided with an undercoat layer. For example, when a colored layer is provided, the undercoat layer may be provided between the colored layer and the polyester film. The undercoat layer can be formed using a binder, a crosslinking agent, a surfactant, and the like.

Examples of the binder contained in the undercoat layer include polyester, polyurethane, acrylic resin, and polyolefin. In addition to the binder, epoxy, isocyanate, melamine, carbodiimide, oxazoline and other crosslinking agents, anionic and nonionic surfactants, silica and other fillers may be added to the undercoat layer.

<Anti-fouling layer (fluorine resin layer / silicon resin layer)>
The polyester film of the present invention is preferably provided with at least one of a fluorine-based resin layer and a silicon-based (Si-based) resin layer as an antifouling layer. By providing the fluorine-based resin layer or the Si-based resin layer, it is possible to prevent contamination of the polyester surface and improve weather resistance. Specifically, it is preferable to have a fluororesin-based coating layer described in JP 2007-35694 A, JP 2008-28294 A, and WO 2007/063698.
Moreover, it is also preferable to stick together fluorine resin films such as Tedlar (manufactured by DuPont).

[Solar cell module]
The solar cell module of the present invention includes the polyester film of the present invention or the back sheet for the solar cell module of the present invention.
The solar cell module of the present invention comprises a solar cell element that converts light energy of sunlight into electric energy, a transparent substrate on which sunlight is incident, and the polyester film (back sheet for solar cell) of the present invention described above. It is arranged and arranged between. The substrate and the polyester film can be formed by sealing with a resin (so-called sealing material) such as an ethylene-vinyl acetate copolymer.

Components other than solar cell modules, solar cells, and backsheets are described in detail in, for example, “Solar Power Generation System Constituent Materials” (supervised by Eiichi Sugimoto, Industrial Research Committee, Inc., issued in 2008).

The transparent substrate only needs to have a light-transmitting property through which sunlight can be transmitted, and can be appropriately selected from base materials that transmit light. From the viewpoint of power generation efficiency, the higher the light transmittance, the better. For such a substrate, for example, a glass substrate, a transparent resin such as an acrylic resin, or the like can be suitably used.

Solar cell elements include silicon-based materials such as single crystal silicon, polycrystalline silicon, and amorphous silicon, III-V groups such as copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenic, and II Various known solar cell elements such as -VI group compound semiconductor systems can be applied.

Hereinafter, the features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

Cyclic carbodiimide compounds 1 to 4 represented by the general formula (O-1) or (O-2) of the present invention having the following structures were used as end capping agents in each Example.

The compounds 1 to 4 used in each example were synthesized by the following method.

[Synthesis Example 1]
(Synthesis of Compound 1)
400 ml of water, 400 ml of concentrated hydrochloric acid, 0.5 mol of sodium nitrate and 5 mmol of lanthanum nitrate hexahydrate were charged into a reactor equipped with a stirrer, and a solution of 0.5 mol of carvacrol dissolved in 1 L of ether was cooled with water. It was added dropwise over 1 hour. Then, it was made to react under air cooling for 2 hours, extracted twice with 1 L of chloroform, and washed sufficiently with water. The obtained organic phase was dehydrated with magnesium sulfate and concentrated. Then, it refine | purified with column chromatography and obtained 202g of ortho nitro bodies of carvacrol.
Next, the nitro compound (0.1 mol) obtained above, 1,2-dibromoethane (0.05 mol), potassium carbonate (0.3 mol), 200 ml of N, N-dimethylformamide were installed in a stirrer and a heating device. The reactor was charged in an N ₂ atmosphere and reacted at 130 ° C. for 12 hours. After that, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and separated three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product A (nitro form).
Next, intermediate product A (0.1 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction is performed in a state where hydrogen is constantly supplied at 25 ° C., and the reaction is terminated when there is no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.
Next, an intermediate product B (0.025 mol), imidazole (0.2 mol), carbon disulfide (0.2 mol), and 150 ml of acetonitrile are charged in a reactor equipped with a stirrer and a heating device under an N ₂ atmosphere. The temperature of the reaction solution is raised to 80 ° C. and reacted for 15 hours. The obtained acetonitrile solution was concentrated and purified by column chromatography to obtain intermediate product C (thiourea).
Next, an intermediate product C (0.025 mol), p-toluenesulfonyl chloride (0.1 mol), and 50 ml of pyridine are charged and stirred in a reactor equipped with a stirrer in an N ₂ atmosphere. After reacting at 25 ° C. for 3 hours, 150 ml of methanol is added, and the mixture is further stirred at 25 ° C. for 1 hour. Thereafter, 500 ml of chloroform was added and washed thoroughly with water. The obtained chloroform solution was dehydrated with magnesium sulfate, concentrated, and purified by column chromatography to obtain the target compound. The structure was confirmed by NMR and IR.
¹ H-NMR (CDCl ₃ ) δ (ppm); 1.22 (12H), 2.33 (6H), 3.41 (2H), 4.18 (4H), 6.94 (4H)
Compound 1 was synthesized by the above reaction.

[Synthesis Example 2]
(Synthesis of Compound 2)
A reactor in which the nitro compound (0.1 mol) obtained in Synthesis Example 1, pentaerythritol tetrabromide (0.025 mol), potassium carbonate (0.3 mol), and 200 ml of N, N-dimethylformamide were installed with a stirring device and a heating device. The reaction mixture was charged under N ₂ atmosphere and reacted at 130 ° C. for 12 hours. Then, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane, followed by separation three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product A (nitro form).
Next, intermediate product A (0.02 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction is performed in a state where hydrogen is constantly supplied at 25 ° C., and the reaction is terminated when there is no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.
Next, an intermediate product B (0.015 mol), imidazole (0.2 mol), carbon disulfide (0.2 mol), and 150 ml of acetonitrile are charged in a reactor equipped with a stirrer and a heating device under an N ₂ atmosphere. The temperature of the reaction solution is raised to 100 ° C. and reacted for 15 hours. The solid precipitated after the reaction was collected by filtration and washed to obtain an intermediate product C (thiourea compound).
Next, an intermediate product C (0.01 mol), paratoluenesulfonyl chloride (0.1 mol), and 50 ml of pyridine are charged and stirred in a reactor equipped with a stirrer in an N ₂ atmosphere. After reacting at 25 ° C. for 3 hours, 150 ml of methanol is added, and the mixture is further stirred at 25 ° C. for 1 hour. Thereafter, 500 ml of chloroform was added and washed thoroughly with water. The obtained chloroform solution was dehydrated with magnesium sulfate, concentrated, and purified by column chromatography to obtain the target compound. The structure was confirmed by NMR and IR.
Compound 2 was synthesized by the above reaction.

[Synthesis Example 3]
(Synthesis of Compound 3)
171 g (1.0 mol) of 3-hydroxybiphenyl was dissolved in 1700 ml of nitromethane, cooled to 2 ° C. in an ice bath, 34 ml of fuming nitric acid was added dropwise with stirring, and the mixture was stirred as it was for 12 hours. 200 ml of water was added, the reactive organism was extracted with 500 ml of chloroform, washed with 200 ml of hydrochloric acid and 100 ml of water, and then concentrated. Thereafter, it was produced by column chromatography to obtain 41 g (0.3 mol) of 2-nitro-3-hydroxybiphenyl.
Next, the nitro compound (0.1 mol) obtained above, 1,2-dibromoethane (0.05 mol), potassium carbonate (0.3 mol), 200 ml of N, N-dimethylformamide were installed in a stirrer and a heating device. The reactor was charged in an N ₂ atmosphere and reacted at 130 ° C. for 12 hours. After that, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and separated three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product A (nitro form).
Next, intermediate product A (0.1 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction is performed in a state where hydrogen is constantly supplied at 25 ° C., and the reaction is terminated when there is no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.
Next, an intermediate product B (0.025 mol), imidazole (0.2 mol), carbon disulfide (0.2 mol), and 150 ml of acetonitrile are charged in a reactor equipped with a stirrer and a heating device under an N ₂ atmosphere. The temperature of the reaction solution is raised to 80 ° C. and reacted for 15 hours. The obtained acetonitrile solution was concentrated and purified by column chromatography to obtain intermediate product C (thiourea).
Next, an intermediate product C (0.025 mol), p-toluenesulfonyl chloride (0.1 mol), and 50 ml of pyridine are charged and stirred in a reactor equipped with a stirrer in an N ₂ atmosphere. After reacting at 25 ° C. for 3 hours, 150 ml of methanol is added, and the mixture is further stirred at 25 ° C. for 1 hour. Thereafter, 500 ml of chloroform was added and washed thoroughly with water. The obtained chloroform solution was dehydrated with magnesium sulfate, concentrated, and purified by column chromatography to obtain the target compound. The structure was confirmed by NMR and IR.
Compound 3 was synthesized by the above reaction.

[Synthesis Example 4]
(Synthesis of Compound 4)
A reactor in which the nitro compound (0.1 mol) obtained in Synthesis Example 3, pentaerythritol tetrabromide (0.025 mol), potassium carbonate (0.3 mol), and 200 ml of N, N-dimethylformamide are installed with a stirrer and a heating device. The reaction mixture was charged under N ₂ atmosphere and reacted at 130 ° C. for 12 hours. Then, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane, followed by separation three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product A (nitro form).
Next, intermediate product A (0.02 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction is performed in a state where hydrogen is constantly supplied at 25 ° C., and the reaction is terminated when there is no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.
Next, an intermediate product B (0.015 mol), imidazole (0.2 mol), carbon disulfide (0.2 mol), and 150 ml of acetonitrile are charged in a reactor equipped with a stirrer and a heating device under an N ₂ atmosphere. The temperature of the reaction solution is raised to 100 ° C. and reacted for 15 hours. The solid precipitated after the reaction was collected by filtration and washed to obtain an intermediate product C (thiourea compound).
Next, an intermediate product C (0.01 mol), paratoluenesulfonyl chloride (0.1 mol), and 50 ml of pyridine are charged and stirred in a reactor equipped with a stirrer in an N ₂ atmosphere. After reacting at 25 ° C. for 3 hours, 150 ml of methanol is added, and the mixture is further stirred at 25 ° C. for 1 hour. Thereafter, 500 ml of chloroform was added and washed thoroughly with water. The obtained chloroform solution was dehydrated with magnesium sulfate, concentrated, and purified by column chromatography to obtain the target compound. The structure was confirmed by NMR and IR.
Compound 4 was synthesized by the above reaction.

A ketene imine compound represented by the general formula (1) of the present invention having the following structure was used in each Example as an end-capping agent.

The above exemplified compounds (1), (4), (7) and (9) used in each example were synthesized by the following method.

[Synthesis Example 5]
(Synthesis of Exemplified Compound 1)

2- (4-hydroxyphenyl) -3-methylbutyric acid (29.1 g, 150 mol) and acetic anhydride (375 ml) were charged into a three-necked flask and stirred under reflux for 3 hours. After confirming the completion of the reaction by TLC, excess acetic anhydride was distilled off under reduced pressure. The obtained solid was dissolved in ethyl acetate and subjected to liquid separation washing with 1N aqueous hydrochloric acid. The solvent was distilled off to obtain 31.0 g (yield: 87.5%) of (1-A). The structure was confirmed by NMR.

(1-A) 17.1 g (72.4 mmol), thionyl chloride 21.5 g (181 mmol), and toluene 50 mL were charged into a three-necked flask and stirred at 70 ° C. for 1 hour. After confirming the completion of the reaction by TLC, excess thionyl chloride and the solvent were distilled off under reduced pressure. Subsequently, 50 mL of toluene was added to dissolve the product, and then the mixture was cooled to 5 ° C., and 14.8 g (159 mmol) of aniline and 16.1 g (159 mmol) of triethylamine were slowly added dropwise at the same time, followed by stirring for 2 hours under ice cooling. . After distilling off the solvent under reduced pressure, the residue was dissolved in ethyl acetate and washed with 1N hydrochloric acid. The solvent was distilled off to obtain 16.2 g of (1-B). (Yield 88%)

(1-B) 16.2 g (52 mmol), sodium methoxide (28% methanol solution) 15.0 g, and methanol 50 mL were charged into a three-necked flask and stirred at room temperature for 2 hours. After confirming the completion of the reaction by TLC, ethyl acetate was added, followed by liquid separation washing with 1N aqueous hydrochloric acid. After the solvent was distilled off under reduced pressure, crystallization was performed with an ethyl acetate / hexane mixed solvent to obtain 12.2 g of (1-C). (Yield 87%)

(1-C) 10.7 g (40 mmol), potassium carbonate 16.6 g (120 mmol), and DMF 70 mL were charged into a three-necked flask and stirred at 50 ° C. under nitrogen. Then, 4.31 g (20 mmol) of 1,4-dibromobutane was added dropwise, the system temperature was raised to 110 ° C., and the reaction was performed for 24 hours. After the reaction, ethyl acetate was added, and the mixture was washed with 1N hydrochloric acid, then with 1N aqueous sodium hydrogencarbonate and saturated aqueous sodium chloride. After the solvent was distilled off under reduced pressure, crystallization was performed with a 2-propanol / hexane mixed solvent to obtain 8.3 g of (1-D) (yield 70%).

(1-D) 6.0 g (10.1 mmol), triphenylphosphine 6.9 g (26.3 mmol) triethylamine 4.08 g (40.5 mmol), carbon tetrachloride 3.12 g (20.2 mmol), chloroform 210 mL A three-necked flask was charged and stirred at 70 ° C. under nitrogen for 8 hours. The solvent was concentrated under reduced pressure, washed with hexane, and purified by silica gel chromatography to obtain 2.5 g of exemplary compound (1). (Yield: 45%)
¹ H-NMR (DMSO-d6) δ (ppm); 1.2 (12H), 1.8-1.9 (4H), 2.9 (2H), 4.0 (4H), 6.9- 7.0 (4H), 7.1 (4H), 7.2-7.5 (10H)

[Synthesis Example 6]
(Synthesis of Exemplary Compound 4)

Benzophenone 15.1 g (76 mmol), pentaerythritol tetrabromide 6.08 g (16 mmol), potassium carbonate 31.1 g (225 mmol), and DMF 130 ml were charged into a three-necked flask and stirred at 130 ° C. for 10 hours. The solid obtained by distilling off the solvent under reduced pressure was washed once with distilled water and once with ethanol, and crystallized with ethyl acetate to obtain 13.0 g of (4-A) (yield 95%). The structure was confirmed by NMR.

(4-A) 10.9 g (12.7 mmol), aniline 7.08 g (76.2 mmol), DABCO 22.96 g (154.6 mmol) and 390 ml of chlorobenzene were charged into a three-necked flask and stirred at 125 ° C. for 1 hour. Subsequently, 9.9 g (51 mmol) of tetrachlorotitanium was added and stirred for 4 hours. The resulting reaction solution was filtered under reduced pressure and subsequently concentrated, and the resulting solid was washed with ethanol to obtain 13.5 g of (4-B) (yield 92%). The structure was confirmed by NMR.

(4-B) 10.2 g (8.7 mmol), triethylbenzylammonium chloride 6.0 g, and chloroform 90 ml were charged into a three-necked flask, and 60 g of 50% aqueous sodium hydroxide solution was added all at once with sufficient stirring. Stir at 45 ° C. for 1 hour. 120 ml of pure water and 180 ml of chloroform were added and washed twice with pure water, and the solvent was distilled off under reduced pressure to obtain 12.9 g (8.7 mmol) of (4-C) (yield 100%). The structure was confirmed by NMR.

A flask was charged with 12.9 g (8.7 mmol) of (4-C), 39 g of sodium iodide and 210 ml of acetone and refluxed at 75 ° C. for 2 hours. The reaction solution was slowly added dropwise to a 3.5% aqueous sodium thiosulfate solution, stirred for 1 hour, and then filtered under reduced pressure to obtain a solid. The obtained solid was purified by column chromatography to obtain 7.2 g (6.0 mmol) of exemplary compound (4) (yield 69%). The structure was confirmed by NMR.
¹ H-NMR (CDCl ₃ ) δ (ppm); 4.32 (8H), 7.05 (8H), 7.20 (20H), 7.36 (20H), 7.45 (8H)

[Synthesis Example 7]
(Synthesis of Exemplified Compound 7)

2- (4-Hydroxyphenyl) -3-methylbutyric acid (32.0 g, 165 mmol) and 1N aqueous sodium hydroxide solution (450 mL) were charged into a three-necked flask and stirred at room temperature. A solution of 16.9 g (83 mmol) of terephthaloyl chloride in 100 mL of toluene was added dropwise at room temperature. After completion of the dropwise addition, 450 mL of 2N aqueous sodium hydroxide solution was added. After reacting for 4 hours, 450 mL of 3N hydrochloric acid was added to bring the pH in the system to 2, and a solid was precipitated. The organic layer was filtered to obtain 39.0 g of (7-A) (yield 88%).

(7-A) 16.0 g (30 mmol) and THF 180 mL were charged into a three-necked flask and stirred with ice water to 4.61 mL (30 mmol) of methanesulfonic acid chloride, followed by 11.5 mL of N, N-diisopropylethylamine (30 mmol). 66 mmol) was added dropwise. After stirring for 5 hours and confirming the completion of the reaction by TLC, a solution of 5.04 g (54 mmol) of aniline in 50 mL of THF and 11.5 mL (66 mmol) of N, N-diisopropylethylamine were added dropwise, and N, N-dimethyl- A small amount of 4-aminopyridine was added. After stirring at room temperature for 3 hours and confirming the completion of the reaction by TLC, liquid separation washing was performed with a saturated aqueous sodium chloride solution, a 1N aqueous hydrochloric acid solution, a saturated aqueous sodium chloride solution, and then water. After the solvent was distilled off, recrystallization was performed with ethyl acetate to obtain 11.7 g of (7-B) (yield 60%).

(7-B) 5.73 g (9.1 mmol), triphenylphosphine 6.18 g (23.7 mmol), triethylamine 3.68 g (36.4 mmol), carbon tetrachloride 2.80 g (18.2 mmol), chloroform 190 mL Was stirred in a three-necked flask at 70 ° C. under nitrogen for 8 hours. By concentrating the solvent under reduced pressure and then washing with hexane. 3.7 g of exemplary compound (7) was obtained (yield 83%).
¹ H-NMR (DMSO-d6) δ (ppm); 0.6 (6H), 0.9 (6H), 2.1-2.3 (m, 2H), 6.7 (4H), 6. 9 (2H), 7.0-7.2 (4H), 7.2-7.3 (4H), 7.3-7.4 (4H), 7.7 (4H)

[Synthesis Example 8]
(Synthesis of Exemplified Compound 9)

17.2 g (0.1 mol) of ethyl pivaloyl acetoacetate, 2.7 g (20 mmol) of pentaerythritol, and 0.3 g (1.5 mmol) of paratoluenesulfonic acid were stirred at 180 ° C. in a nitrogen atmosphere. After confirming disappearance of the raw material by TLC, the temperature of the system was lowered to room temperature and dissolved in ethyl acetate. Water was added for liquid separation, the organic layer was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. Purification by column chromatography gave 9.7 g of (9-A) (yield 76%).

(9-A) 9.0 g (14 mmol) 1,8-diazabicyclo [5.4.0] undeca7-ene 9.2 ml (62 mmol) in 30 ml of tetrahydrofuran was cooled with ice and 2,6-dimethylphenyl A solution of 10.1 g (62 mmol) of thioisocyanate in 10 ml of tetrahydrofuran was slowly added dropwise. The temperature of the reaction system was raised to room temperature, and after confirming disappearance of the raw material by TLC, water / ethyl acetate was added for liquid separation. The organic layer was washed with brine and water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and purification was performed by column chromatography to obtain 16.5 g of (9-B). (Yield 91%)

(9-B) To a solution of 10.0 g (7.7 mmol) of chloroform in 100 ml of chloroform was added, under ice cooling, 2.0 g (11.8 mmol) of 2-chloro-1,3-dimethylimidazolium chloride in 50 ml of chloroform, 4.3 ml (30.8 mmol) of triethylamine was slowly added dropwise. After completion of the dropwise addition, the temperature of the reaction system was slowly raised to room temperature while stirring. After confirming the disappearance of the raw material by TLC, chloroform / water was added for liquid separation, and the solvent was distilled off under reduced pressure. Purification by silica gel column chromatography gave 5.6 g of exemplary compound (9) (yield 63%).
¹ H-NMR (CDCl ₃ -d) δ (ppm); 1.3 (36H), 2.1 (24H), 4.2 (8H), 7.0-7.2 (12H)

Furthermore, the following compounds were used in the Examples as ketene imine-based end capping agents. The following Exemplified Compound A and Exemplified Compound B are compounds represented by mono and bis described in Examples of US Pat. No. 3,692,745.

(Examples 1 to 37, Comparative Examples 1 to 4)
(Preparation of polyester)
(1) PET
A polymer of polyethylene terephthalate was obtained by the method described in JP-A-2011-165698. Specifically, 100 parts by mass of dimethyl terephthalate, 61 parts by mass of ethylene glycol, and 0.06 parts by mass of magnesium acetate tetrahydrate were charged into a transesterification reaction vessel, heated to 150 ° C., melted and stirred. The reaction was advanced while the temperature inside the reaction vessel was slowly raised to 235 ° C., and the methanol produced was distilled out of the reaction vessel. When the distillation of methanol was completed, 0.02 parts by mass of trimethyl phosphoric acid was added. After adding trimethyl phosphoric acid, 0.03 parts by mass of antimony trioxide was added, and the reaction product was transferred to a polymerization apparatus. Subsequently, the temperature in the polymerization apparatus was raised from 235 ° C. to 290 ° C. over 90 minutes, and at the same time, the pressure in the apparatus was reduced from atmospheric pressure to 100 Pa over 90 minutes. When the stirring torque of the contents of the polymerization apparatus reached a predetermined value, the interior of the apparatus was returned to atmospheric pressure with nitrogen gas to complete the polymerization. The valve at the bottom of the polymerization apparatus was opened and the inside of the polymerization apparatus was pressurized with nitrogen gas, and the polymerized polyethylene terephthalate was discharged into water in the form of a strand. The strand was chipped with a cutter. Thus, PET having an intrinsic viscosity IV = 0.50 and AV = 20 was obtained. This was designated as PET-A.

(2) PEN
Using 100 parts of dimethyl naphthalene-2,6-dicarboxylate and 60 parts of ethylene glycol, 0.03 part of manganese acetate tetrahydrate as a transesterification catalyst, and gradually increasing the temperature from 150 ° C. to 238 ° C. for 120 minutes A transesterification reaction was performed. On the way, when the reaction temperature reached 170 ° C, 0.024 part of antimony trioxide was added. After the transesterification reaction, trimethyl phosphate (135 ° C in ethylene glycol, 0.11 to 0.16 MPa added for 5 hours) The solution heat-treated under pressure: 0.023 parts in terms of trimethyl phosphate was added. Thereafter, the reaction product is transferred to a polymerization reactor, heated to 290 ° C., and subjected to a polycondensation reaction under a high vacuum of 27 Pa or less, and an intrinsic viscosity of 0.61 dl / g and AV = 18 is substantially obtained. Polyethylene-2,6-naphthalenedicarboxylate containing no particles was obtained. This is referred to as PEN-A.

(Solid-state polymerization of polyester)
PET-A and PEN-A were subjected to solid phase polymerization according to JP-A-2009-182186. Specifically, the obtained polymers (PET-A, PEN-A) were pre-dried at 155 ° C. for 3 hours, and then subjected to solid phase polymerization in a nitrogen gas atmosphere. The solid phase polymerization temperature was 210 ° C. and solid phase polymerization was performed for the time described in Table 1 below. When the solid phase polymerization time is lengthened, IV is easily increased and AV is likely to be decreased. By increasing the solid phase polymerization temperature, AV is increased and IV is likely to be decreased.

Using solid phase polymerized PET, PEN (PET-B, PEN-B), non-solid phase polymerized PET, PEN (PET-A, PEN-A / solid phase polymerization time = 0 in Table 1) Thus, a master pellet containing fine particles was prepared. Moreover, the terminal blocker was also added to some pellets. Furthermore, a pellet containing no fine particles (diluted pellet) was blended to form a film. Moreover, the terminal blocker was added to some dilution pellets. The same PEN and PET (same solid phase polymerization time) were used for both the master pellet and the diluted pellet.

(Manufacture of master pellets containing aromatic polyester, fine particles, and end-capping agent)
Fine particles are dried for 24 hours at 80 ° C. in PET (generally referred to as PET-A and PET-B) and PEN (generally referred to as PEN-A and PEN-B) to a water content of 30 ppm or less. It put into the extruder and knead | mixed for 3 minutes at 280 degreeC in nitrogen stream. Table 1 shows the composition of the fine particles and polyester, the torque fluctuation of the screw of the twin screw extruder, the kind of fine particles, and the amount added (to the aromatic polyester).

<Fine particles>
TiO ₂ -1: rutile dioxide acid number of titanium (surface alumina coating, the average particle diameter of 0.2 [mu] m)
TiO ₂ -2: rutile dioxide acid number of titanium (surface coated with alumina and trimethylolpropane, average particle size 0.3 [mu] m)
BaSO ₄ -1: Barium sulfate simple substance BaSO ₄ -2: Barium sulfate is coated with silica Note that these particle sizes are measured by the method described in JP-A-2009-263604 after the film is formed by the method described below and the fine particles are taken out from the film. did.

Moreover, the terminal blocker selected from the following was added to the biaxial kneading extruder by the quantity of Table 1 to some master pellets.
Cyclic carbodiimide compound Sealant A: Compound 1 described in the above chemical formula
Sealant B: Compound 2 described in the above chemical formula
Sealant C: Compound 3 described in the above chemical formula
Sealant D: Compound 4 described in the above chemical formula
Sealant E: WO 2011/093478, p177-8 Compound of Reference Example 5 Sealant F: WO 2011/093478, p178-180 Compound of Reference Example 6 Sealant G: Stabilizer 9000 (manufactured by Raschig)
Sealants E and F were synthesized according to WO2011 / 093478.

These aromatic polyesters, fine particles, and end-capping agents were mixed using a twin-screw extruder and performed at 280 ° C. in a nitrogen stream for 3 minutes. After kneading, it was extruded into water as a strand and cooled and solidified, and then cut into a diameter of 3 mm and a length of 5 mm to obtain a master pellet.

Table 1 summarizes the composition of the master pellets used in Examples 1 to 37 and Comparative Examples 1 to 4 and the preparation conditions thereof. In MP13 to MP22, the end-capping agent is not added to the master pellet, but these end-capping agents are added in the film forming process.

(Film formation)
Aromatic polyester pellets for dilution were mixed with the master pellets so that the fine particle concentrations (concentrations in the film) shown in Table 2 were obtained. In the present invention 29 to 35 in Table 2, a carbodiimide compound is mixed during film formation by adding a part of the carbodiimide compound to an aromatic polyester pellet for dilution.

Prior to extrusion, the mixture was dried at 80 ° C. for 12 hours or more to reduce the water content to 30 ppm or less, and then kneaded using a twin screw extruder at 280 ° C. while performing a vacuum vent. After passing through a gear pump, this was filtered with a filter having an opening of 20 μm.

Passed through a die after filtration. In the case of a single layer, it was passed through a coat hanger die, and in the case of a laminate, it was passed through a feed block die.
A heater is provided at a point (6 points in total) divided into 3 rows x 12 width directions at intervals of 5 cm in the longitudinal direction (3 rows upstream from 3 cm from the die lip) on a 1 m wide die, and each temperature is changed. The temperature distribution of the die was given. The first row in the longitudinal direction was alternately repeated at high temperature and low temperature, the second row in the longitudinal direction was repeated at high temperature, medium temperature, and high temperature, and the third row in the longitudinal direction was repeated at high temperature, high temperature, and low temperature.
The temperature distribution of the die was measured by measuring the temperature at the intermediate point between each heater with a contact thermometer, and the difference between the maximum temperature and the minimum temperature was divided by the average value and divided into hundreds of parts.
It was extruded from a die onto a cooling drum at 30 ° C. and solidified. At this time, air at room temperature was sent to promote solidification. Further, electrostatic application was performed in the vicinity of the contact point between the melt coming out of the die and the cooling drum.

(Stretching)
The unstretched sheet obtained above was alternately passed through eight preheating rolls (diameter 300 mmφ, wrap angle 180 degrees) in a zigzag manner.

After longitudinal stretching, the PET-based level was 120 ° C. and the PEN-based level was 160 ° C., and the film was stretched 4 times using a tenter. Thereafter, each level was heat-fixed at 210 ° C. and then subjected to relaxation treatment at 190 ° C. for each of MD and TD by 3%. Thereafter, the chuck portions at both ends were trimmed, and knurling was applied to wind up 2000 m. This thickness is shown in Table 2.

(Evaluation methods)
Particle size sample film is treated in air at 900 ° C. for 2 hours to remove the particles. This was measured using a particle analyzer by the method described in [0054] of JP-A-2009-263604.

The microparticle aggregation rate sample film was observed in cross-section parallel to MD and TD (observed at 5000 times using SEM). Arbitrarily 100 fine particles are observed, and those having a closest distance of 0.3 μm or less between the particles are regarded as aggregated particles. This number divided by the number of observations (100) and expressed as a percentage was defined as “fine particle aggregation rate”. This was measured in MD cross section and TD cross section, and the average value was shown.

The thickness variation sample film of the thickest layer of the laminated film was observed at a cross section of 10 points per 1 cm (observed at 5000 times using SEM). The thickness of each layer was measured, and the difference between the maximum thickness and the minimum thickness of the 10 thickness measurements of each thickest layer was divided by the average thickness and expressed as a percentage. This measurement was obtained with MD and TD cross sections, and the average value was defined as the thickness variation.

IV, AV
AV and IV were measured by the following method with respect to the film after film forming. The carboxyl terminal amount AV was measured by the method of Malice. (Reference M. J. Malice, F. Huizinga. Anal. Chim. Acta, 22 363 (1960)).
The intrinsic viscosity (IV) of these polyesters obtained was obtained from the following equation by dissolving the polyester in orthochlorophenol and measuring the solution viscosity measured at 25 ° C.
ηsp / C = [η] + K [η] ² · C
Where ηsp = (solution viscosity / solvent viscosity) −1, C is the weight of dissolved polymer per 100 ml of solvent (1 g / 100 ml in this measurement), and K is the Huggins constant (0.343) The solution viscosity and the solvent viscosity were measured using an Ostwald viscometer.

Cutting waste at the time of cutting The cutting waste at the time of cutting was measured by the following method.
i) Using a Thomson blade having a blade angle of 60 degrees, punching was performed at 25 ° C. at 50 mm / min and a linear pressure of 5 kg / mm. (The chip angle is obtuse, and it is easy to generate chips by making it difficult to cut.)
ii) The top surface was rubbed with black paper for a length of 1 m, and the number of chips on this was counted and listed in Table 1 (number of chips before the thermo test).
iii) Chip after the thermo test: The above-mentioned chip measurement was similarly cut and measured after 100 hours at 120 ° C. and 100% rh, and listed in Table 1 (chip after the thermo test / polyester was added by this thermo. Because it decomposes and lowers its molecular weight, it becomes more brittle and chips are more likely to be generated).

Visible light reflectance The visible light reflectance of the film was determined in accordance with the reflectance measurement method described in JP2011-25473A.

Sensory evaluation was performed to determine whether there was an irritating odor peculiar to the decomposition product of carbodiimide at the outlet of the off- flavor tenter. The results are listed.

As shown in Table 2, the present inventions 1 to 5 have a film thickness of 100 μm and an aggregation rate of 10 to 50%. These show that the generation of cutting waste after cutting is markedly suppressed compared to Comparative Example 1 where the aggregation rate is 9% and Comparative Example 2 where the aggregation rate is 52%. In Comparative Example 1, the generation of cutting waste after the thermo is doubled compared to before the thermo, but in the present inventions 1 to 5, the generation of cutting waste is suppressed even after the thermo.

In the inventions 6 to 28, the thickness of the film is 50 to 250 μm, and the content of the cyclic carbodiimide compound is 0.1 to 5% by mass. These show that the generation of cutting scraps before and after the thermo is markedly suppressed as compared with Comparative Example 3 in which the aggregation rate is 8%.

Inventions 29 to 36 are laminated films in which films are laminated. Also in the laminated film, the generation of cutting waste before and after the thermostat is suppressed, and it can be seen that the same effect as in the case of the single layer is obtained.

Comparative Example 4 is a combination of Example 1 (PET + cyclic sealant) of JP2011-258641 and Example 23 (polylactic acid + cyclic sealant + fine particles (BaSO4)) of WO2011 / 093478. Although Example 4 contains fine particles, the agglomeration rate is not within the scope of the present invention, so the generation of cutting waste is not suppressed, and the present invention 37 is an example corresponding to Comparative Example 4, and the fine particles It turns out that generation | occurrence | production of cutting waste is suppressed by making the aggregation rate of 30%.

(Examples 38 to 70, Comparative Examples 5 and 6)
Examples 38-70 and Comparative Examples 5 and 6 were prepared in the same manner as in Example 1 except that the following ketene imine compound was used as the terminal blocking agent.

Ketene imine compound Sealant H: Exemplary compound (1) described in the above chemical formula
Sealant I: Exemplary compound (4) described in the above chemical formula
Sealant J: Exemplary compound (7) described in the chemical formula above
Sealant K: Exemplary compound (9) described in the chemical formula above
Sealant L: Exemplified Compound A described in the above chemical formula
Sealant M: Exemplified compound B described in the above chemical formula

Table 3 summarizes the composition of the master pellets used in Examples 38 to 70 and Comparative Examples 5 and 6 and the preparation conditions thereof.

The obtained master pellets were mixed with aromatic polyester pellets for dilution, and prepared so as to have the fine particle concentration (concentration in the film) shown in Table 4. In the subsequent steps such as film formation and stretching, the same treatment as in Example 1 was performed.

As shown in Table 4, the present invention 38 to 42 has a film thickness of 75 μm and an aggregation rate of 10 to 50%. These show that the generation of cutting waste after cutting is significantly suppressed as compared with Comparative Example 5 in which the aggregation rate is 9% and Comparative Example 6 in which the aggregation rate is 52%. In Comparative Examples 5 and 6, the generation of cutting waste after the thermo is doubled compared to that before the thermo, but in the present inventions 38 to 42, the generation of cutting waste is suppressed even after the thermo.

In the present invention 43 to 63, the thickness of the film is 50 to 250 μm, and the content of the ketene imine compound is 0.1 to 5 mass%. Also in these, it turns out that generation | occurrence | production of the cutting waste before and behind thermostat is suppressed markedly.

The present invention 64-70 is a laminated film in which films are laminated. Also in the laminated film, the generation of cutting waste before and after the thermostat is suppressed, and it can be seen that the same effect as in the case of the single layer is obtained.

According to the present invention, when cutting an aromatic polyester film containing a cyclic carbodiimide compound and fine particles, generation of cutting waste can be suppressed. For this reason, the aromatic polyester film of this invention becomes favorable for adhesiveness with a solar cell panel, and is used suitably as a back seat | sheet of a solar cell. The present invention can increase the production efficiency of an aromatic polyester film containing a cyclic carbodiimide compound and fine particles, and has high industrial applicability.

DESCRIPTION OF SYMBOLS 10 Barrel 12 Supply port 14

Extruder outlet

16A,

16B Vent

20A, 20B Screw 21 Drive motor 22 Flight 23

Reduction gear

24A, 24B Kneading part 30 Temperature control means 100 Twin screw extruder C1-C9 Heating / cooling device

Claims

Cyclic carbodiimide compound or ketene imine compound having at least one cyclic structure in the molecule containing one carbodiimide group in the ring skeleton, the first nitrogen and the second nitrogen being bonded by a bonding group, fine particles, and aromatic Including polyester resin,
The content of the cyclic carbodiimide compound or the ketene imine compound is 0.1 to 5% by mass with respect to the mass of the aromatic polyester resin,
The particle size of the fine particles is 0.1 to 10 μm, and the content of the fine particles is 1 to 10% by mass with respect to the mass of the aromatic polyester resin.
An aromatic polyester film characterized in that a part of the fine particles are aggregated and the aggregation rate is 10 to 50%.
The aromatic polyester film according to claim 1, wherein the cyclic carbodiimide compound is represented by the following general formula (O-1) or general formula (O-2).

(In general formula (O-1), R 1 and R 5 each independently represents an alkyl group, an aryl group or an alkoxy group. R 2 to R 4 and R 6 to R 8 each independently represents a hydrogen atom, Represents an alkyl group, an aryl group or an alkoxy group, R 1 to R 8 may combine with each other to form a ring, X 1 and X 2 each independently represents a single bond, —O—, —CO—, Represents —S—, —SO 2 —, —NH— or —CH 2 —, and L 1 represents a divalent linking group.

(In the general formula (O-2), R 11 , R 15 , R 21 and R 25 each independently represents an alkyl group, an aryl group or an alkoxy group. R 12 to R 14 , R 16 to R 18 , R 22 ~ R 24 and R 26 ~ R 28 each independently represent a hydrogen atom, an alkyl group, .R represents an aryl group or an alkoxy group 11 ~ R 28 are bonded may also form a ring .X 11 together, X 12 , X 21 and X 22 each independently represents a single bond, —O—, —CO—, —S—, —SO 2 —, —NH— or —CH 2 —, wherein L 2 represents a tetravalent group. Represents a linking group.)
In the general formulas (O-1) and (O-2), R 1 and R 5 , and R 11 , R 15 , R 21 and R 25 are each independently a secondary or tertiary alkyl group or aryl. The aromatic polyester film according to claim 2, wherein the aromatic polyester film represents a group.
4. The aromatic polyester film according to claim 2 , wherein R 2 and R 6 are both hydrogen atoms in the general formula (O-1).
The aromatic polyester film according to claim 1, wherein the ketene imine compound is represented by the following general formula (1).

(In the general formula (1), R 1 and R 2 each independently represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group; 3 represents an alkyl group or an aryl group.)
The aromatic polyester film according to claim 1, wherein the ketene imine compound is represented by the following general formula (2).

(In General Formula (2), R 1 represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R 2 represents L 1 as a substituent. Represents an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group, wherein R 3 represents an alkyl group or an aryl group, and n is 1 to 4. Represents an integer, and L 1 represents an n-valent linking group.)
In the said General formula (2), n is 3 or 4, The aromatic polyester film of Claim 6 characterized by the above-mentioned.
The aromatic polyester film according to claim 1, wherein the ketene imine compound is represented by the following general formula (3).

(In General Formula (3), R 1 and R 5 represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R 2 and R 4 Represents an alkyl group having L 2 as a substituent, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group or an aryloxycarbonyl group, and R 3 and R 6 are an alkyl group or an aryl group. L 2 represents a single bond or a divalent linking group.)
The aromatic according to any one of claims 5 to 8, wherein a molecular weight of a portion excluding a nitrogen atom constituting the ketene imine of the ketene imine compound and a substituent bonded to the nitrogen atom is 320 or more. Polyester film.
The aromatic polyester resin mainly contains terephthalic acid, naphthalene dicarboxylic acid as a dicarboxylic acid component, and ethylene glycol as a diol component,
The aromatic polyester according to any one of claims 1 to 9, wherein the intrinsic viscosity (IV) is 0.7 to 0.9 g / dl, and the acid value (AV) is 1 to 20 eq / ton. the film.
A laminated film comprising at least one layer of the aromatic polyester film according to any one of claims 1 to 10, wherein the number of laminated layers is 2 to 8.
The laminated film according to claim 11, wherein a variation rate of a thickness of a layer having the largest thickness among the layers constituting the laminated film is 1 to 10%.
Cyclic carbodiimide compound or ketene imine compound having at least one cyclic structure in the molecule containing one carbodiimide group in the ring skeleton, the first nitrogen and the second nitrogen being bonded by a bonding group, fine particles, and aromatic In the method for producing an aromatic polyester film containing a polyester resin,
Kneading the aromatic polyester resin and the fine particles to prepare master pellets;
After mixing and extruding the master pellets and aromatic polyester pellets, it has a step of casting from a die onto a cooling drum to form a film,
At least one of the step of preparing the master pellet or the step of forming the film includes a step of mixing the cyclic carbodiimide compound or the ketene imine compound,
The particle size of the fine particles is 0.1 to 10 μm, and the content of the fine particles is 1 to 10% by mass with respect to the mass of the aromatic polyester resin,
The step of preparing the master pellet includes a step of kneading the aromatic polyester resin and fine particles with a screw rotation torque, and producing an aromatic polyester film in which a fluctuation of 0.1 to 10% is given to the screw rotation torque Method.
The method for producing an aromatic polyester film according to claim 13, wherein the screw rotation torque is given a fluctuation of 1 to 100 times / minute.
The method for producing an aromatic polyester film according to claim 13 or 14, wherein the film forming step includes a step of imparting a temperature distribution of 1 to 10 ° C to the inside of the die.
16. The method for producing an aromatic polyester film according to claim 13, wherein the cyclic carbodiimide compound is represented by the following general formula (O-1) or general formula (O-2): .

(In general formula (O-1), R 1 and R 5 each independently represents an alkyl group, an aryl group or an alkoxy group. R 2 to R 4 and R 6 to R 8 each independently represents a hydrogen atom, Represents an alkyl group, an aryl group or an alkoxy group, R 1 to R 8 may combine with each other to form a ring, X 1 and X 2 each independently represents a single bond, —O—, —CO—, Represents —S—, —SO 2 —, —NH— or —CH 2 —, and L 1 represents a divalent linking group.

(In the general formula (O-2), R 11 , R 15 , R 21 and R 25 each independently represents an alkyl group, an aryl group or an alkoxy group. R 12 to R 14 , R 16 to R 18 , R 22 ~ R 24 and R 26 ~ R 28 each independently represent a hydrogen atom, an alkyl group, .R represents an aryl group or an alkoxy group 11 ~ R 28 are bonded may also form a ring .X 11 together, X 12 , X 21 and X 22 each independently represents a single bond, —O—, —CO—, —S—, —SO 2 —, —NH— or —CH 2 —, wherein L 2 represents a tetravalent group. Represents a linking group.)
In the general formulas (O-1) and (O-2), R 1 and R 5 , and R 11 , R 15 , R 21 and R 25 are each independently a secondary or tertiary alkyl group or aryl. The method for producing an aromatic polyester film according to claim 16, wherein the group represents a group.
The method for producing an aromatic polyester film according to claim 16 or 17, wherein in the general formula (O-1), R 2 and R 6 are both hydrogen atoms.
The method for producing an aromatic polyester film according to any one of claims 13 to 15, wherein the ketene imine compound is represented by the following general formula (1).

(In the general formula (1), R 1 and R 2 each independently represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group; 3 represents an alkyl group or an aryl group.)
The method for producing an aromatic polyester film according to any one of claims 13 to 15, wherein the ketene imine compound is represented by the following general formula (2).

(In General Formula (2), R 1 represents an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R 2 represents L 1 as a substituent. Represents an alkyl group, aryl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, aryloxy group, acyl group or aryloxycarbonyl group, wherein R 3 represents an alkyl group or an aryl group, and n is 1 to 4. Represents an integer, and L 1 represents an n-valent linking group.)
In the said General formula (2), n is 3 or 4, The manufacturing method of the aromatic polyester film of Claim 20 characterized by the above-mentioned.
The method for producing an aromatic polyester film according to any one of claims 13 to 15, wherein the ketene imine compound is represented by the following general formula (3).

(In General Formula (3), R 1 and R 5 represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group. R 2 and R 4 Represents an alkyl group having L 2 as a substituent, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group or an aryloxycarbonyl group, and R 3 and R 6 are an alkyl group or an aryl group. L 2 represents a single bond or a divalent linking group.)
The aromatic group according to any one of claims 19 to 22, wherein a molecular weight of a portion excluding a nitrogen atom constituting the ketene imine of the ketene imine compound and a substituent bonded to the nitrogen atom is 320 or more. A method for producing a polyester film.
An aromatic polyester film produced by the production method according to any one of claims 13 to 23.
A back sheet for a solar cell module using the aromatic polyester film according to any one of claims 1 to 10 and claim 24.
The solar cell module backsheet using the laminated film of Claim 11 or 12.
A solar cell module using the back sheet for a solar cell module according to claim 25 or 26.