TW201726806A - Polyester composition for master batches, polyester composition for films, and polyester film - Google Patents

Abstract

The present invention is a polyester composition for master batches, which contains prescribed amounts of: a polyester having a dicarboxylic acid component and a glycol component as constituents; a magnesium compound; an alkali metal compound; a specific phosphorous compound; and a lubricant, and which has a sufficiently low melt resistivity and is excellent in hue and thermal stability. Adding this polyester composition for master batches enables enhancing of electrostatic adhesion to a cooling drum so as to improve film formation properties, and imparting of optimum slippage, thereby providing a polyester film that also has excellent quality.

Description

Polyester composition for masterbatch, polyester composition for film, and polyester film

The present invention relates to a polyester composition for a masterbatch for imparting good electrostatic adhesion to a polyester film to improve film formability, and to impart slidability and workability.

Polyester is excellent in mechanical properties and chemical properties, and is used in a wide range of fields such as packaging, tape, and optical applications. The polyester film is obtained by melt-extruding a polyester and performing biaxial stretching. That is, the sheet which is melt-extruded by the extruder is adhered to the surface of the rotating cooling cylinder to be wound (cast), and then the sheet is guided to the stretching roll disposed in the rear stage of the cooling cylinder. In the longitudinal direction, the tenter is used for lateral extension and then heat-fixed. Here, in order to increase the uniformity of the thickness of the film and increase the speed of casting, if the sheet melt-extruded from the extrusion die is cooled on the surface of the rotary cooling cylinder, the sheet and the surface of the cylinder must be made Adhere with a high enough adhesion. Therefore, as a method for improving the adhesion of the sheet to the surface of the rotating cylinder, the so-called electrostatic close casting method is used as follows: a linear electrode is provided between the extrusion nozzle and the cooling rotary cylinder to apply a high voltage. The surface of the uncured sheet is electrostatically generated, and the sheet is electrostatically attached to the surface of the cooling cylinder to be quenched.

It is known that in the electrostatic adhesion casting method, in order to improve the electrostatic adhesion of the sheet to the cooling cylinder, it is effective to increase the amount of charge on the surface of the sheet, and in order to increase the amount of the charge, it is effective to make the polyester which becomes the raw material. Modification reduces the melt resistivity. In addition, as a method of reducing the melt resistivity, an alkali metal or an alkaline earth metal compound is added to the esterification or transesterification reaction in the production stage of the raw material polyester (for example, see Patent Document 1).

As another method of lowering the melt resistivity, the following operations are also carried out: a large amount of an alkali metal or an alkaline earth metal compound is added to separately produce a masterbatch having a very low melt resistivity, and is mixed in a polyester which is a raw material of the film (for example) Refer to Patent Document 2). However, when a master batch is produced, since a large amount of an alkali metal or an alkaline earth metal compound is added, there is a problem that foreign matter is likely to be generated, a problem of easy coloring, or a problem of deterioration in thermal stability. Further, as a masterbatch, a sufficiently low value of the melt resistivity cannot be obtained, and it is necessary to mix a large amount of the master batch with the polyester of the film raw material, which is also disadvantageous in terms of cost.

The film polyester has a problem in that the film is adhered to each other when the film is superposed to cause so-called blocking, or a defect such as damage due to poor sliding property with a guide roll or the like when the roll film is processed. In order to solve the problem of the operation of such a film, it is effective to provide a method in which an inert particle such as an inorganic particle is contained in the inside of the polyester.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2010-285527.

Patent Document 2: Japanese Laid-Open Patent Publication No. 2008-201822.

An object of the present invention is to provide a polyester composition for a masterbatch having a sufficiently low melt resistivity and excellent color tone and thermal stability, and a polyester film which is mixed by the polyester film. The polyester composition for the master batch improves the electrostatic adhesion to the cooling cylinder and improves the film formability, and is provided with optimum slidability and excellent quality.

As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by the means described below, and the present invention has been completed.

That is, the present invention includes the following constitution.

[1] A polyester composition for a masterbatch, comprising: a polyester, a magnesium compound, an alkali metal compound, a phosphorus compound, and a lubricant; and the polyester has a dicarboxylic acid component and a diol component as constituent components, and The phosphorus compound is selected from the group consisting of a phosphorus compound which is a trialkyl phosphate and an alkyl group of an alkyl ester is an alkyl group having 2 to 4 carbon atoms, and ethyl diethylphosphonium acetate. At least one; and the aforementioned masterbatch polyester composition satisfies (1) to (4).

(1) The polyester composition contains 400 ppm to 2,700 ppm of magnesium atoms, 40 ppm to 270 ppm of alkali metal atoms, and 200 ppm to 1,700 ppm of phosphorus atoms in terms of mass.

(2) The polyester composition contains a lubricant having an average particle diameter of 0.5 μm to 3.0 μm of 7,000 ppm to 20,000 ppm.

(3) The amount of the magnesium atom is m (mol%), the amount of the alkali metal atom is k (mol%), and the amount of the phosphorus atom is p (mol%) with respect to the dicarboxylic acid component constituting the polyester. When, the formula I is satisfied.

2≦(m+k/2)/p≦3.5 (Formula I).

(4) The melt resistivity ρi satisfies 0.005 × 10 ⁸ Ω ‧ cm to 0.05 × 10 ⁸ Ω ‧ cm.

[2] The polyester composition for a master batch according to [1], wherein the alkali metal is potassium.

[3] The polyester composition for a masterbatch according to [1] or [2] wherein the phosphorus compound is a trialkyl phosphate and the alkyl group of the alkyl ester is an alkyl group having 2 to 4 carbon atoms. Phosphorus compound.

[4] The polyester composition for a master batch according to [1] or [2] wherein the phosphorus compound is triethyl phosphate.

[5] A polyester composition for a masterbatch according to any one of [1] to [4].

[6] A polyester film comprising the polyester composition for a film according to [5].

The polyester composition for a masterbatch of the present invention is produced by adding a specific amount of a magnesium compound, an alkali metal compound, a phosphorus compound, and a lubricant, and has a low melt resistivity, so that film formation properties of a film using the same can be improved. Further, since the amount of foreign matter is small, the color tone and thermal stability are also excellent, and the slidability at the time of film formation is also excellent, it can be used in a wide range of applications such as a film for packaging and an industrial film.

Fig. 1 is a graph showing the relationship between the amount of metal and the refractive resistivity in the examples and comparative examples.

[Polyester composition for masterbatch]

The polyester composition for a masterbatch of the present invention is blended into a polyester resin for a film raw material to form a polyester composition for a film.

The melt resistivity (ρi) of the polyester composition for a masterbatch of the present invention needs to be 0.005 × 10 ⁸ Ω ‧ cm to 0.05 × 10 ⁸ Ω ‧ cm. The melt resistivity can be measured by the method described in the section of the examples described later. In order to improve the film formability of the polyester film, it is preferred that the melt resistivity of the polyester composition for a film is from 0.1 × 10 ⁸ Ω ‧ cm to 0.3 × 10 ⁸ Ω ‧ cm, but if the polyester composition for the master batch When the melt resistivity is higher than 0.05 × 10 ⁸ Ω ‧ cm, a large amount of the amount of the master batch is required in order to improve the film formability of the film polyester, so that the efficiency as a master batch is low and the manufacturing cost is increased. And other issues. When the melt resistivity of the polyester composition for the master batch is less than 0.005 × 10 ⁸ Ω ‧ cm, the amount of the master batch added is too small, so segregation is liable to occur, and the melt resistivity of the film is uneven. , the film stability is reduced. More preferably, the melt resistivity of the polyester composition for the master batch is from 0.005 × 10 ⁸ Ω ‧ cm to 0.025 × 10 ⁸ Ω ‧ cm.

In the polyester composition for a masterbatch of the present invention, a magnesium compound or an alkali metal compound is added in order to lower the melt resistivity. Further, it is presumed that these metal ion components form a salt by reaction with a carbonyl terminal group of an unreacted dicarboxylic acid component or an oligomer component, and foreign matter is generated, but in order to prevent foreign matter from being generated by the metal ions, The phosphorus compound is added by dispersing in the polyester to further improve thermal stability. When the foreign matter is agglomerated, there may be a case where the coarse defects (coarse particles) in the film obtained by using the polyester composition for the master batch are used.

As the magnesium compound used in the present invention, a known magnesium compound can be used. For example, a lower fatty acid salt such as magnesium acetate or an alkoxide such as methoxy magnesium may be used, and these may be used alone or in combination of two or more. Especially preferred is magnesium acetate.

The amount of the magnesium atom is from 400 ppm to 2700 ppm with respect to the polyester composition for the master batch. When the amount of magnesium atoms is less than 400 ppm, the melt resistivity becomes high, and in order to improve the film formability of the polyester composition for a film, a large amount of the amount of the master batch is required, so that the efficiency as a master batch is low and the manufacturing cost is increased. Great question. Insoluble in the case where the amount of magnesium atoms exceeds 2700 ppm The amount of formation of foreign matter (magnesium salt) increases, and heat resistance is lowered and the color of the film becomes severe, which is not preferable. Preferably, the amount of magnesium atoms is from 450 ppm to 2500 ppm, and more preferably the amount of magnesium atoms is from 450 ppm to 2000 ppm.

Examples of the alkali metal of the alkali metal compound used in the present invention include lithium, sodium, and potassium. In addition, examples of the alkali metal compound include a lower fatty acid salt such as lithium acetate or potassium acetate, or an alkoxide such as potassium methoxide. These may be used alone or in combination of two. More than one species. As the alkali metal, potassium is preferred because it has a large effect of lowering the melt resistivity. As the alkali metal compound, an acetate salt is preferred, and potassium acetate is particularly preferred.

The amount of the alkali metal atom is from 40 ppm to 270 ppm with respect to the polyester composition for the master batch. When the atomic weight of the alkali metal is less than 40 ppm, the melt resistivity becomes high, and in order to improve the film formability of the polyester composition for a film, a large amount of the polyester for the master batch is required, so that the effect as a master batch is low. And manufacturing costs increase and other issues. When the amount of the alkali metal atom exceeds 270 ppm, the heat resistance is lowered and the color of the film becomes severe, which is not preferable. The amount of the alkali metal atom is preferably from 45 ppm to 250 ppm, and more preferably the amount of the alkali metal atom is from 45 ppm to 200 ppm.

The phosphorus compound which can be used in the present invention may, for example, be phosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, phosphinic acid or the like. For example, phosphoric acid, trimethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, phosphorous Acid, trimethyl phosphite, tributyl phosphite, methylphosphonic acid, dimethyl methylphosphonate, dimethyl ethylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate , diphenyl phenylphosphonate, ethyl diethylphosphonium acetate, phosphinic acid, methylphosphinic acid, dimethylphosphinic acid, phenylphosphinic acid, diphenylphosphinic acid Methyl dimethyl phosphinate, methyl diphenylphosphinate. Among these, in order to highly express the effects of the present invention, the phosphorus compound is preferably a phosphorus compound selected from the group consisting of a trialkyl phosphate and an alkyl group of the alkyl ester having an alkyl group having 2 to 4 carbon atoms and At least one of the group consisting of ethyl diethylphosphonium acetate. Among them, a phosphate triester having an alkyl group having 2 to 4 carbon atoms is preferably used. Specific examples thereof include triethyl phosphate, tripropyl phosphate, and tributyl phosphate. These may be used alone or in combination of two or more. In particular, triethyl phosphate is preferred because it forms a complex having an interaction with magnesium ions having a moderate strength and a polyester composition having a low melt resistivity and a small amount of foreign matter and excellent color tone.

The amount of the phosphorus atom is from 200 ppm to 1700 ppm with respect to the polyester composition for the master batch. When the amount of phosphorus atoms is less than 200 ppm, the magnesium ions and the alkali metal ions are stabilized, and the effect of dispersing in the polyester is lowered, and the amount of foreign matter which is insoluble is increased. Further, since the effect of reducing the melt resistivity of the magnesium of the foreign material is lost, the melt resistivity is increased with respect to the amount of magnesium added. In addition, the heat resistance is lowered and the color of the film becomes severe, which is not preferable. When the amount of phosphorus atoms exceeds 1700 ppm, an excessive amount of the phosphorus compound interacts with the magnesium ions. Therefore, the charge of the magnesium ions does not contribute to the effect of lowering the melt resistivity, and the melt resistivity is high with respect to the amount of magnesium added, which is not preferable. More The amount of phosphorus atoms is preferably from 220 ppm to 1000 ppm.

A lubricant is added to the polyester composition for a masterbatch of the present invention for the purpose of improving the handling characteristics of the film. The lubricant is an inert particle such as an inorganic particle, and by adding the lubricant, irregularities are formed on the surface at the time of film formation, and the film is imparted with migration property, slidability, windability, workability, and the like.

The lubricant used in the present invention may, for example, be an oxide of a metal such as titanium, aluminum, barium, calcium, magnesium or strontium, a carbonate, a citrate, a sulfate or an aluminate. Examples thereof include titanium dioxide, aluminum oxide, aluminum silicate, silica, calcium oxide, calcium carbonate, barium sulfate, and the like, and natural talc, mica, kaolin, zeolite, and the like, but are not limited thereto. In these.

The lubricant has an average particle diameter of from 0.5 μm to 3.0 μm, more preferably from 0.8 μm to 2.5 μm. When it is less than 0.5 μm, the effect of forming irregularities on the surface and imparting workability such as slidability and migration property is lowered, which is not preferable. On the other hand, when it exceeds 3.0 μm, the quality of the film may be impaired by the formation of coarse protrusions, which is not preferable. The average particle diameter of the lubricant was measured by a particle size distribution meter using a laser light scattering method as described in the Examples.

The amount of the lubricant is 7000 ppm to 20,000 ppm based on the mass of the polyester composition for the master batch. When the polyester composition for a film is blended in a polyester resin for a film raw material, a polyester composition for a master batch is added so that the amount of the lubricant becomes a preferable amount. If the lubricant does not reach 7000ppm, Since a large amount of the polyester composition for the master batch is added, the color tone and heat resistance are deteriorated. In addition, since the performance as a masterbatch is low, the manufacturing cost is increased. When the amount of the lubricant exceeds 20,000 ppm, the amount of metal in the polyester composition for a film is decreased, and the melt resistivity is increased to deteriorate the film properties, which is not preferable. Further, the agglomeration of the lubricant at the time of polymerization is associated with an increase in the number of coarse defects (coarse particles) after blending and dilution, which is not preferable. The lower limit of the content of the lubricant is preferably 8,000 ppm or more, more preferably 10,000 ppm or more, still more preferably 12,000 ppm or more. The upper limit of the content is preferably 18,000 ppm or less.

The content of the magnesium atom, the alkali metal atom, the phosphorus atom and the lubricant in the polyester composition for the master batch can be quantified by the method described in the following examples. The period of addition of the magnesium compound, the alkali metal compound and the phosphorus compound to the polyester is not particularly limited, but by esterification (or esterification) in the polymerization of the polyester, especially in the esterification (or transesterification) step. The addition of the step from the end of the step to the start of the polycondensation step suppresses the formation of a salt of the acid component of the polyester with the magnesium ion or the alkali metal ion, and can be uniformly dispersed in the oligomer, so that it is preferred. . The period of addition of the lubricant to the polyester is not particularly limited, but is by the time of polymerization of the polyester, especially in the middle of the esterification (or transesterification) step, or the end of the esterification (or transesterification) step. It is preferred that the polycondensation step is added between the start and can be uniformly dispersed in the oligomer.

When the compound is added during the polymerization of the polyester, the magnesium atom and the alkali metal atom remain substantially in the amount of the polyester and remain in the polyester composition, but Since the phosphorus atom is distilled off to the outside of the polymerization system in a reduced pressure atmosphere, the relationship between the added amount and the residual amount must be known in advance, and then the amount of the phosphorus compound added is determined. The lubricant remains substantially in the amount of addition and remains in the polyester composition.

When the polyester is a polyester having a dicarboxylic acid component and a diol component as a constituent component, the amount of the magnesium atom relative to the dicarboxylic acid component is m (mol%), and the amount of the alkali metal atom is k ( When the amount of the phosphorus atom is p (mol%), the molar ratio of the magnesium atom, the alkali metal atom, and the phosphorus atom satisfies the following formula I, whereby the effects of the present invention are obtained.

2≦(m+k/2)/p≦3.5 (Formula I)

It is considered that the phosphorus atom stabilizes the magnesium ion and the alkali metal ion without being foreignized. The magnesium ion is divalent, whereas the alkali metal ion is monovalent. Therefore, the sum of the amount of magnesium ion and the alkali metal ion is expressed as (m+k/2), and the ratio is obtained by dividing p. "(m+k/2)/p" is the relative amount of magnesium ions and alkali metal ions with respect to the phosphorus atoms.

If the value of "(m+k/2)/p" exceeds 3.5, the amount of phosphorus atoms is relatively small relative to the magnesium atom and the alkali metal atom, so that the magnesium ion and the alkali metal ion are stabilized and dispersed. The amount of foreign matter (magnesium salt, alkali metal salt) which is low in insolubility in the polyester is increased. Further, since the effect of reducing the melt resistivity of the magnesium of the foreign material is lost, the melt resistivity is increased with respect to the amount of magnesium added. In addition, the heat resistance is lowered and the color of the film becomes severe. If the value of "(m+k/2)/p" is less than 2, the amount of phosphorus atoms is relatively excessive with respect to the magnesium atom and the alkali metal atom, and the excess phosphorus compound Since the substance interacts with the magnesium ion, the charge of the magnesium ion does not contribute to the effect of lowering the melt resistivity, and the melt resistivity becomes higher with respect to the amount of magnesium added. "(m+k/2)/p" is more preferably 2.3 or more and 3 or less, further preferably 2.5 or more and 3 or less.

"(m+k/2)/p" in the formula I can also be calculated from the content of each atom in the polyester composition for the master batch.

In the same manner as described above, when the amount of magnesium atoms is m (mol%) and the amount of alkali metal atoms is k (mol%), the amount of metal (the total amount of magnesium atoms and alkali metal atoms) and the melting resistivity are When the relationship satisfies the following formula II, it is considered that the added metal does not cause foreign matter to contribute to a decrease in the melt resistivity (ρi), and the polyester composition for a masterbatch of the present invention satisfies Formula II.

R<1.2×10 ^-2 /(m+k/2) (Formula II)

(here, R = ρi × 10 ^-8 )

The magnesium compound or the alkali metal compound has an effect of lowering the melt resistivity, and the magnesium ion is divalent. On the other hand, since the alkali metal ion is monovalent, the sum of the amount of the magnesium ion and the alkali metal ion (m+k) /2) is a factor that exerts a large effect on the melt resistivity.

When the added metal is foreignized, the foreign materialized metal hardly contributes to the melting resistivity, and therefore the melt resistivity becomes higher than that of the system which is not foreign materialized. Therefore, when deviating from the formula II, there is a possibility that the melt resistivity with respect to the amount of added metal becomes high, and the amount of metal which causes foreign matter increases. In general, the relationship between the amount of metal and the value of the melt resistivity is inversely proportional. Fig. 1 is a graph showing the relationship between the metal amount (m + k / 2) and the value (ρi) of the melt resistivity of Examples 1 to 9 and Comparative Examples 1 to 5 which will be described later. In the figure, the examples are indicated by "◇" and the comparative examples are indicated by "●". As can be seen from the figure, the range in which the effects of the present invention are obtained is the range below the curve. Since the curve is a curve of R = 1.2 × 10 ^-2 / (m + k / 2), the above formula II is derived.

The polyester of the present invention is a polyester having a dicarboxylic acid component and a diol component as constituent components. One type or two or more types of dicarboxylic acid component and diol component can be used. A polyvalent carboxylic acid may be contained in addition to the dicarboxylic acid, and a polyhydric alcohol may be contained in addition to the diol. Alternatively, a unit containing a hydroxycarboxylic acid or a cyclic ester may be contained.

The manufacture of the polyester can be carried out by a previously known method. For example, in the case of a polyester composed of terephthalic acid and ethylene glycol, it can be carried out by any of the following methods: a method of performing polycondensation after esterification of terephthalic acid with ethylene glycol; A method of performing polycondensation after transesterification of an alkyl ester of terephthalic acid such as dimethyl terephthalate with ethylene glycol. In addition, the polymerization device may be batch type or continuous type.

As the catalyst, a metal-containing polyester polycondensation catalyst such as a ruthenium compound, an aluminum compound, a titanium compound, a tin compound or a ruthenium compound which is known as a polymerization catalyst for polyester can be used. Among them, an aluminum compound which is excellent in foreign matter suppression or thermal stability is preferably used.

The polyester composition for a masterbatch of the present invention contains a polymerization catalyst component. When a ruthenium compound is used, it is preferably used in the polyester composition for the master batch, The mass conversion contains 50 ppm to 300 ppm of germanium atoms. In the case of using an aluminum compound, it is preferred to contain 20 ppm to 100 ppm of aluminum atoms in terms of mass in the polyester composition for the master batch. When a titanium compound is used, it is preferably contained in a polyester composition for a masterbatch containing 5 ppm to 150 ppm of titanium atoms in terms of mass. When a tin compound is used, it is preferable that the polyester composition for the master batch contains 50 ppm to 200 ppm of tin atoms in terms of mass. When a ruthenium compound is used, it is preferably contained in the polyester composition for the master batch, and contains 50 ppm to 200 ppm of ruthenium atoms in terms of mass. In the case of a ruthenium compound, an aluminum compound, a titanium compound or a tin compound, the amount of the ruthenium compound, the aluminum compound, the titanium compound or the tin compound remains substantially in the polyester composition, but in the case of a ruthenium compound, it may be reduced. It is preferable to adjust the amount of addition in such a manner that the residual amount in the polyester composition is within the above range.

The polymerization catalyst of the polyester can be added to the reaction system at any stage of the polymerization reaction. For example, it may be added to the reaction system before the start of the esterification reaction or the transesterification reaction, at any stage in the middle of the reaction, immediately before the start of the polycondensation reaction, or at any stage in the middle of the polycondensation reaction.

Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, sebacic acid, decane dicarboxylic acid, and ten. Dialkyldicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexane Carboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornane a saturated aliphatic dicarboxylic acid exemplified by a dicarboxylic acid, a dimer acid or the like or an ester-forming derivative thereof; an unsaturated aliphatic exemplified by fumaric acid, maleic acid, itaconic acid or the like Dicarboxylic acid or such ester-forming derivative; phthalic acid, isophthalic acid, terephthalic acid, 5-(alkali metal) sulfoisophthalic acid, diphenyl phthalic acid, 1,3 -naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4'-biphenyl Carboxylic acid, 4,4'-biphenylfluorene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 1,2-bis(phenoxy)ethane-pair, p-dicarboxylic acid, Pa An aromatic dicarboxylic acid exemplified by a phenolic acid, a quinone dicarboxylic acid, or the like, or an ester-forming derivative thereof.

Examples of the polycarboxylic acid other than the dicarboxylic acid include ethane tricarboxylic acid, propane tricarboxylic acid, butane tetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, and 3,4. , 3', 4'-biphenyltetracarboxylic acid, and ester-forming derivatives thereof.

Examples of the diol include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, diethylene glycol, triethylene glycol, 1,2-butanediol, and 1,3-butylene glycol. 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3- Cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexane Alkyl diethanol, 1,10-decanediol, 1,12-dodecanediol and the like alkyl diol, polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, etc. The exemplified aliphatic diol; hydroquinone, 4,4'-dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-bis(β-hydroxyethoxy) Phenyl) hydrazine, Bis(p-hydroxyphenyl)ether, bis(p-hydroxyphenyl)fluorene, bis(p-hydroxyphenyl)methane, 1,2-bis(p-hydroxyphenyl)ethane, bisphenol A, bisphenol C, 2 An aromatic diol exemplified by 5-naphthyl glycol or a diol obtained by adding ethylene oxide to the diol.

Examples of the polyhydric alcohol other than the diol include trimethylolethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerin, and hexanetriol.

Examples of the hydroxycarboxylic acid include lactic acid, citric acid, malic acid, tartaric acid, glycolic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and 4-hydroxycyclohexane. An alkanecarboxylic acid, or an ester-forming derivative thereof.

Examples of the cyclic ester include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, and lactide.

Examples of the ester-forming derivative of a polyvalent carboxylic acid or a hydroxycarboxylic acid include such alkyl esters, hydrazine chloride, and acid anhydrides.

As the polyester used in the present invention, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, poly(1,4-terephthalate) are preferred. Cyclohexanedimethyl ester), polyethylene naphthalate, polybutylene naphthalate, propylene naphthalate and copolymers thereof, especially Polyethylene terephthalate and copolymers thereof.

The polyester composition for a masterbatch of the present invention may contain one or more diethylene glycol inhibitors, a fluorescent whitening agent, a color tone adjusting agent such as a dye or a pigment, and an ultraviolet inhibitor, depending on the purpose of use. Various additives such as infrared absorbing dyes, heat stabilizers, surfactants, and antioxidants. As the diethylene glycol inhibitor, a basic compound such as an alkylamine compound or an ammonium salt compound can be used, and as the antioxidant, an antioxidant such as an aromatic amine or a phenol can be used, and as a stabilizer, a sulfur system can be used. A stabilizer such as an amine system.

These additives may be added to the polyester composition for the master batch in a ratio of preferably 10% by mass or less, more preferably 5% by mass or less.

The color tone (Co-b) of the polyester composition for masterbatch of the present invention in the form of particles is preferably from 0 to 40, more preferably from 0 to 30. The masterbatch polyester composition is mixed into a polyester resin for a film raw material to form a film polyester composition, and is formed into a film. Even if the color tone (Co-b) of the polyester composition for the master batch in the form of particles is relatively high, there is no problem if the film material is diluted with the polyester resin so that the color tone of the film is in a preferable range. .

The inherent viscosity (IV) of the polyester composition for a masterbatch of the present invention is preferably from 0.3 dl/g to 0.7 dl/g. The masterbatch polyester composition is mixed into a polyester resin for a film raw material to form a film polyester composition, and is formed into a film. Even if the intrinsic viscosity (IV) of the masterbatch polyester composition in the form of particles is relatively high or low, as long as the membrane material is diluted with a polyester resin, the intrinsic viscosity (IV) of the film is compared. There is no problem with the good range.

[Film composition for film, polyester film]

The polyester composition for a film of the present invention is obtained by mixing the above-mentioned polyester composition for a masterbatch and a polyester resin (composition) for a film raw material in an arbitrary ratio. The polyester film can be obtained from the polyester composition for a film of the present invention by a known film forming method.

The polyester resin (composition) for the film raw material may or may not contain an alkali metal compound or an alkaline earth metal compound for lowering the melt resistivity. When the polyester composition for a masterbatch of the present invention is blended in a polyester resin for a film raw material which does not contain an alkali metal compound or an alkaline earth metal compound and has a high melt resistivity, it is equivalent to a general polyester composition for a film. The above film forming properties. When the polyester composition of the master batch of the present invention is mixed with the polyester composition of the film raw material containing the alkali metal compound or the alkaline earth metal compound, the film formability can be further improved.

The polyester which can be used for the polyester resin (composition) for the film raw material is the same as the polyester which can be used for the polyester composition for the above-mentioned masterbatch. The polyester used for the polyester resin (composition) for the film raw material and the polyester used for the polyester composition for the master batch are preferably the same as the polyester containing the same constituent.

It is preferred that the amount of magnesium atom in the polyester composition for film is from 15 ppm to 150 ppm, the amount of alkali metal is from 1.5 ppm to 15 ppm, and the amount of phosphorus atom is from 7 ppm to 80 ppm. Specifically, it is preferred to prepare a polyester composition for a film containing 1% by mass to 20% by mass of the polyester composition for a masterbatch of the present invention, and more preferably a polyester composition for containing the master batch 2 A polyester composition for a film of from 5% by mass to 10% by mass. If the polyester group for masterbatch is mixed in such a range As a product, a film excellent in the balance of melt resistivity, color tone, and heat resistance can be obtained. The color tone (Co-b) of the film is preferably 0 to 6, more preferably 0 to 5.2, still more preferably 0 to 5, as measured by the method described in the examples.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples. Further, the measurement method of the main characteristic value will be described below.

(1) Intrinsic viscosity of polyester resin ‧ composition (IV)

The polyester composition (polyester resin) was dissolved in a 6/4 (by weight) mixed solvent of phenol/1,1,2,2-tetrachloroethane, and the temperature was measured at 30 °C.

(2) Melt resistivity

Two electrodes (a stainless steel wire having a diameter of 0.6 mm) were placed at both ends of the polyester composition melted at 275 ° C, and sandwiched by two quartz plates having a width of 2 cm, and a width of 2 cm and a thickness of 0.6 mm were formed in this manner. The layer of the molten polyester composition was uniformly measured, and the current (io) when a direct current voltage of 120 V was applied was measured at a temperature of 280 ° C, and this was substituted into the following formula to obtain a melt resistivity value ρ (Ω ‧ cm).

Ρi(Ω‧cm)=(A/L)×(V/io)

[A: electrode area (cm ² ), L: distance between electrodes (cm), V: voltage (V)]

A (cm ² ) = [width of molten polyester composition layer] × [thickness] = 2 (cm) × 0.06 (cm), and V = 120 (V). The L system does not include the value measured by the diameter of the electrode and is 1.3 cm.

(3) Quantitative methods for aluminum, magnesium, potassium, lithium and phosphorus

The polyester composition was heated to [melting point + 20 ° C] in a circular ring made of stainless steel having a thickness of 5 mm and an inner diameter of 50 mm to prepare a sample, and the amount of the element was determined by fluorescent X-ray analysis in ppm. (Quality basis) indication. Further, in the case of quantification, a calibration curve obtained from a sample in which the amount of each element is known in advance is used.

(4) Hue (Co-b)

The color difference (L, a, b) of the particles or film of the polyester composition was measured using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000). The particles were placed in a measuring cell and measured by a reflection method. Ten sheets of the film were superposed and measured by a reflection method.

(5) Heat resistance

The polyester film obtained by mixing the master batch with the polyester composition was placed in a glass ampoule, and after being purged with nitrogen, the glass ampoule was sealed under a reduced pressure of 13.3 kPa (nitrogen atmosphere). The intrinsic viscosity before and after the heat treatment at 300 ° C for 2 hours of heat treatment. The heat resistance is represented by a decrease in the intrinsic viscosity due to heat treatment (ΔIV = [IV after heat treatment] - [IV before heat treatment]). Usually, since the intrinsic viscosity is lowered by heat treatment, the smaller the absolute value of ΔIV, the better the heat resistance.

(6) The number of major defects

The measurement of the number of the rough defects is based on the image analysis using the phase difference optical microscope (manufactured by Nikon Corporation), the objective lens (manufactured by Nikon Corporation, magnification 10 times, opening degree 0.5), and the image of the particles in the cast film. The size and number of particles. The particles are mainly composed of a lubricant, and also contain a foreign matter derived from magnesium ions or alkali metal ions. In the image analysis, the number of aggregated particles of 10 μm or more is measured, and the measurement is performed 20 times while changing the visual field, and the total number of aggregated particles is obtained, and the number of aggregated particles having a field of view area of 10 μm or more per square millimeter is calculated. For the number of major defects. It is judged that the number of rough defects is less than 300, and that of 300 or more is judged as ×.

(7) Average particle size of the lubricant

Using a particle size distribution meter (manufactured by Leeds & Northrup Co., Ltd., Microtrac HRA model 9320-X100) using a laser light scattering method, the ethylene glycol slurry of the lubricant was diluted with water to perform measurement substantially in the water system. The volume of the measurement result was 50% of the diameter as the average particle diameter.

(Reference Example 1) Manufacture of film raw material with polyester resin (X)

To a stainless steel autoclave equipped with a stirrer, a distillation column, and a pressure regulator, 0.54 parts by weight of terephthalic acid, ethylene glycol, and antimony trioxide was added. Further, by adding 0.3 mol% of triethylamine as a diethylene glycol inhibitor to terephthalic acid, the water produced by the esterification was sequentially removed at 240 ° C and a gauge pressure of 0.35 MPa for 2 hours. Reaction.

Then, the temperature of the system was raised to 280 ° C over 1 hour, during which the pressure of the system was gradually reduced to 150 Pa, and under this condition, a polycondensation reaction was carried out for 1 hour to obtain a polyester resin (X) for a film raw material. The obtained polyester resin had an intrinsic viscosity of 0.62 dl/g and a melt resistivity of 3.2 × 10 ⁸ Ω ‧ cm.

(Example 1)

(1) Modulation of cerium oxide slurry

750 g of cerium oxide particles (manufactured by Fuji Silysia Co., Ltd., Silysia 310) having 5 liters of ethylene glycol and an average particle diameter of 2.4 μm were added to a dispersion tank equipped with a homogenizer, and the mixture was stirred and dispersed at 8000 rpm for 2 hours. 150 g / l of slurry.

(2) Manufacture of polyester composition for masterbatch

To a stainless steel autoclave equipped with a stirrer, a distillation column, and a pressure regulator, terephthalic acid and ethylene glycol were added. The cerium oxide slurry was added in such a manner that the cerium oxide became 16,000 ppm with respect to the theoretical amount of the polyester, and triethylamine was added in such a manner that the terephthalic acid became 0.3 mol%, and the esterification reaction was carried out according to a conventional method. , obtaining an oligomer.

Then, basic aluminum acetate, magnesium acetate dihydrate, potassium acetate, and phosphoric acid were added in such a manner that the aluminum atom was 60 ppm, the magnesium atom was 1000 ppm, the potassium atom was 100 ppm, and the phosphorus atom was 660 ppm with respect to the theoretical amount of the polyester. Ethyl ester, the temperature of the system was raised to 280 ° C in 1 hour, during which the pressure of the system was slowly reduced to 150 Pa, and under this condition, a polycondensation reaction was carried out for 80 minutes to obtain a polyester composition for the master batch. Particles of matter. The physical properties of the obtained polyester composition are shown in Table 1. The aluminum atom, the magnesium atom, and the potassium atom are added in a residual amount (content). However, since the phosphorus atom is partially distilled and removed to the outside of the polymerization system in the polycondensation reaction step, the residual amount (content) is decreased with respect to the added amount (hereinafter The same is true in the case).

(3) Film formation of polyester film

The pellet of the polyester composition for the masterbatch produced as described above and the pellet of the polyester resin (X) for the film raw material were mixed at a ratio of 5:95 by mass ratio, and vacuum-dried at 135 ° C for 10 hours. Then, the mixture was quantitatively supplied to a twin-screw extruder, melt-extruded into a sheet shape at 280 ° C, and rapidly cooled and solidified on a metal roll having a surface temperature of 20 ° C to obtain a cast film having a thickness of 1400 μm.

Next, the cast film was heated to 100 ° C by a heated roll group and an infrared heater, and then a uniaxial alignment film was obtained by extending the roll group having a circumferential speed difference by 3.5 times in the longitudinal direction. Then, it was extended by 4.0 times in the width direction at 120 ° C by a tenter, and heated at 260 ° C for 0.5 second by an infrared heater in a state where the width of the fixed film was long, and further 3% relaxation treatment was performed at 200 ° C for 23 seconds. A biaxially oriented polyester film having a thickness of 100 μm was obtained. The properties of the obtained film are shown in Table 1. The number of gross defects is measured by a cast film.

(Example 2)

In the polymerization method of Example 1, the cerium oxide became 8000 ppm, the aluminum atom became 30 ppm, and the magnesium atom was respectively obtained in a theoretical amount relative to the polyester. In the same manner as in Example 1, except that the cerium oxide slurry, the basic aluminum acetate, the magnesium acetate dihydrate, the potassium acetate, and the triethyl phosphate were added in an amount of 500 ppm, the potassium atom was 50 ppm, and the phosphorus atom was 330 ppm. The method obtains particles of a polyester composition for a master batch. The physical properties of the obtained polyester composition are shown in Table 1.

The obtained masterbatch polyester composition and the film raw material polyester resin (X) particles were mixed at a ratio of 10:90 by mass ratio, and the polyester film was treated in the same manner as in Example 1. Film making. The properties of the obtained film are shown in Table 1.

(Example 3)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added in such a manner that the aluminum atom was 80 ppm, the magnesium atom was 2500 ppm, the potassium atom was 250 ppm, and the phosphorus atom was 1650 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 1.

(Example 4)

In the polymerization method of Example 1, alkali aluminum acetate was added so that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 250 ppm, and the phosphorus atom became 530 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that magnesium acetate dihydrate, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 1.

(Example 5)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 100 ppm, and the phosphorus atom became 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and tripropyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 1.

(Example 6)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added in such a manner that the aluminum atom was 60 ppm, the magnesium atom was 1000 ppm, the lithium atom was 90 ppm, and the phosphorus atom was 660 ppm with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the lithium acetate dihydrate and the triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

Film forming method A film was obtained by the same method as in Example 1. Place The properties of the obtained film are shown in Table 1.

(Example 7)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 100 ppm, and the phosphorus atom became 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and ethyl diethylphosphonium acetate were used. The physical properties of the obtained polyester composition are shown in Table 1.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 1.

(Example 8)

In the polymerization method of Example 1, cerium oxide was added in such a manner that the amount of cerium oxide was 12,000 ppm, the aluminum atom was 60 ppm, the magnesium atom was 1000 ppm, the potassium atom was 100 ppm, and the phosphorus atom was 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that the slurry, the alkali aluminum acetate, the magnesium acetate dihydrate, the potassium acetate, and the triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

The obtained masterbatch polyester composition and the film raw material polyester resin (X) particles were mixed at a ratio of 6.7:93.3 by mass ratio, and the polyester film was treated in the same manner as in Example 1. Film making. The properties of the obtained film are shown in Table 1.

(Example 9)

In the polymerization method of Example 1, cerium oxide was added in such a manner that cerium oxide became 18,000 ppm, aluminum atoms were 60 ppm, magnesium atoms were 1000 ppm, potassium atoms were 100 ppm, and phosphorus atoms were 660 ppm, respectively, with respect to the theoretical amount of polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that the slurry, the alkali aluminum acetate, the magnesium acetate dihydrate, the potassium acetate, and the triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 1.

The obtained masterbatch polyester composition and the film raw material polyester resin (X) particles were mixed at a ratio of 4.4:95.6 by mass ratio, and the polyester film was treated in the same manner as in Example 1. Film making. The properties of the obtained film are shown in Table 1.

(Comparative Example 1)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 100 ppm, and the phosphorus atom became 400 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 2.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 2.

(Comparative Example 2)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 30 ppm, the magnesium atom became 500 ppm, the potassium atom became 50 ppm, and the phosphorus atom became 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 2.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 2.

(Comparative Example 3)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 60 ppm, the magnesium atom became 2000 ppm, the potassium atom became 50 ppm, and the phosphorus atom became 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the compound, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 2.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 2.

(Comparative Example 4)

In the polymerization method of Example 1, alkali acetic acid was added in such a manner that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 1000 ppm, and the phosphorus atom became 660 ppm with respect to the theoretical amount of the polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except that aluminum, magnesium acetate dihydrate, potassium acetate, and triethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 2.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 2.

(Comparative Example 5)

In the polymerization method of Example 1, alkali aluminum acetate and magnesium acetate dihydrate were added so that the aluminum atom became 60 ppm, the magnesium atom became 1000 ppm, the potassium atom became 100 ppm, and the phosphorus atom became 660 ppm, respectively, with respect to the theoretical amount of the polyester. Granules of the polyester composition for the master batch were obtained in the same manner as in Example 1 except that the product, potassium acetate, and trimethyl phosphate were used. The physical properties of the obtained polyester composition are shown in Table 2.

Film forming method A film was obtained by the same method as in Example 1. The properties of the obtained film are shown in Table 2.

(Comparative Example 6)

In the polymerization method of Example 1, cerium oxide was added in such a manner that cerium oxide became 5,000 ppm, aluminum atoms were 60 ppm, magnesium atoms were 1000 ppm, potassium atoms were 100 ppm, and phosphorus atoms were 660 ppm, respectively, with respect to the theoretical amount of polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except for the slurry, the basic aluminum acetate, the magnesium acetate dihydrate, the potassium acetate, and the trimethyl phosphate. The physical properties of the obtained polyester composition are shown in Table 2.

The obtained masterbatch polyester composition and the film raw material polyester resin (X) particles were mixed at a ratio of 16:84 by mass ratio, and the polyester film was treated in the same manner as in Example 1. Film making. The properties of the obtained film are shown in Table 2.

(Comparative Example 7)

In the polymerization method of Example 1, cerium oxide was added in such a manner that cerium oxide became 30,000 ppm, aluminum atoms were 60 ppm, magnesium atoms were 1000 ppm, potassium atoms were 100 ppm, and phosphorus atoms were 660 ppm, respectively, with respect to the theoretical amount of polyester. Granules of the polyester composition for a master batch were obtained in the same manner as in Example 1 except for the slurry, the basic aluminum acetate, the magnesium acetate dihydrate, the potassium acetate, and the trimethyl phosphate. The physical properties of the obtained polyester composition are shown in Table 2.

The obtained masterbatch polyester composition and the film raw material polyester resin (X) particles were mixed at a ratio of 2.7:97.3 by mass ratio, and the polyester film was treated in the same manner as in Example 1. Film making. The properties of the obtained film are shown in Table 2.

[Table 1] ※TMPA;Trimethyl phosphate=Trimethyl phosphate ※TEPA;Triethyl phosphate=Triethyl phosphate ※TPPA;Tripropyl phosphate=Tripropyl phosphate ※EDPA; Ethyl diethyl phosphonoacetate=Ethyl diethylphosphonate acetate

※TMPA=trimethyl phosphate ※TEPA=triethyl phosphate ※TPPA=tripropyl phosphate ※EDPA=ethyldiethylphosphonium acetate

The polyester composition for a masterbatch of Examples 1 to 9 has a low melt resistivity and a small amount of foreign matter, and is excellent in color tone and thermal stability of a film obtained by using the film. Further, it is considered that by satisfying the above formula II, the added metal does not cause foreign matter to be formed, contributing to a decrease in the melt resistivity (ρi). Implementation with lithium as an alkali metal In Example 1, in which potassium was used, the melt resistivity was lower and the color tone was superior. In Examples 1 and 5 using trialkyl phosphate (alkyl group having 2 to 4 carbon atoms), the color tone was excellent as compared with Example 7 using ethyl diethylphosphonium acetate as the phosphorus compound. In Example 1 using triethyl phosphate, the melt resistivity became lower as compared with Example 5 using tripropyl phosphate.

In the polyester composition for the masterbatch of Comparative Example 1, since the content of the phosphorus compound is relatively small (the ratio of (m+k/2)/p is large), the color tone is inferior to that of Example 1 having the same amount of magnesium. The obtained film is inferior in heat resistance. In Comparative Example 2, since the content of the phosphorus compound was relatively large (the ratio of (m+k/2)/p was small), it was found that the melt resistivity was high and the film formability was poor. In Comparative Example 3, since the total amount of magnesium and the amount of alkali metal were relatively large (the ratio of (m+k/2)/p was large), the color tone was inferior. In Comparative Example 4, since the content of the potassium compound was large, the color tone was inferior to that of Example 1, and the heat resistance of the obtained film was inferior. In Comparative Example 5, trimethyl phosphate was used as the phosphorus compound, and it was found that the melt resistivity was high and the film formability was inferior. In Comparative Example 6, since the amount of the lubricant as the master batch was small, a large amount of the master batch was added to the film, and thus the color tone of the film was inferior. In Comparative Example 7, since the amount of the lubricant as the master batch was large, the amount of the master batch added was small, and the film had a low melt resistivity and was inferior in film formability. Further, since a large amount of lubricant is added during the polymerization of the master batch, the number of coarse defects is large.

(industry availability)

The polyester composition for the masterbatch of the present invention has a sufficiently low melting resistance Since the ratio is small, the amount of foreign matter is small, and the color tone and thermal stability are also excellent. Therefore, by blending into a polyester for a film raw material, there is an effect of producing a polyester film which is improved in film formability and is optimally provided. Slidability and excellent quality. Therefore, the film using the polyester composition for a masterbatch of the present invention can be used, for example, for a wide range of applications such as an antistatic film, an easy-adhesive film, a card, a sample can, an agricultural product, a building material, For cosmetics, wallpaper, OHP (overhead projector) film, printing, inkjet recording, sublimation transfer recording, laser beam printer recording, electronic photo recording, thermal transfer For recording, thermal transfer recording, printed circuit board wiring, thin film switch, near-infrared absorbing film for plasma display, transparent conductive film for touch panel or electroluminescence, film for masking, photo plate making, X-ray film, photo negative film, retardation film, polarizing film, polarizing film protection (TAC; Tri-Acetyl Cellulose), deflection plate or phase difference plate inspection film and / or a separator, a photosensitive resin film, a field-of-view film, a diffusion sheet, a reflective film, an antireflection film, an ultraviolet ray-proof, a back-grinding tape, or the like.

Claims (6)

A polyester composition for a master batch comprising a polyester, a magnesium compound, an alkali metal compound, a phosphorus compound and a lubricant; the polyester having a dicarboxylic acid component and a diol component as a constituent component; and the phosphorus compound selected from the group consisting of phosphoric acid a trialkyl ester and at least one of the group consisting of a phosphorus compound of an alkyl group having 2 to 4 carbon atoms and ethyl diethylphosphonate acetate; and the aforementioned master batch The polyester composition satisfies the following (1) to (4): (1) the polyester composition contains, by mass, 400 ppm to 2,700 ppm of magnesium atoms, 40 ppm to 270 ppm of alkali metal atoms, and 200 ppm to 1,700 ppm of phosphorus atoms; 2) In the polyester composition, the lubricant having an average particle diameter of 0.5 μm to 3.0 μm is 7,000 ppm to 20,000 ppm; (3) the amount of the magnesium atom is set to m (mol) with respect to the dicarboxylic acid component constituting the polyester. %), when the amount of the alkali metal atom is k (mol%), and the amount of the phosphorus atom is p (mol%), the formula I: 2 ≦ (m + k / 2) / p ≦ 3.5 (formula I) is satisfied (4) The melt resistivity ρi satisfies 0.005 × 10 ⁸ Ω ‧ cm to 0.05 × 10 ⁸ Ω ‧ cm. The polyester composition for a masterbatch according to claim 1, wherein the alkali metal is potassium. The polyester composition for a masterbatch according to claim 1 or 2, wherein the phosphorus compound is a phosphorus compound of a trialkyl phosphate and the alkyl group of the alkyl ester is an alkyl group having 2 to 4 carbon atoms. The polyester composition for a master batch according to claim 1 or 2, wherein the phosphorus compound is triethyl phosphate. A polyester composition for a film, comprising the polyester composition for a master batch according to any one of claims 1 to 4. A polyester film comprising the polyester composition for a film according to claim 5.