Modifier for polyester resin film, composition for polyester resin film, polyester resin film, and method for producing laminated film

Abstract

Provided is a modifier for a polyester resin film that can impart excellent electrostatic adhesion to the polyester resin film, can be stably added to the polyester resin, and has improved workability. 【Solution means】 The modifier for a polyester resin film contains an organic sulfonate. When the total amount of the organic sulfonate is 100% by mass, the content ratio of the organic sulfonate having a particle size of more than 0 μm and 75 μm or less is 5% by mass or less, and the content ratio of the organic sulfonate having a particle size of more than 75 μm and 150 μm or less is 5% by mass or more. Further, it is preferable that the content ratio of the organic sulfonate having a particle size of more than 1000 μm is 10% by mass or less.

Description

Technical Field

[0001] The present disclosure relates to a modifier for polyester resin films, and a method for producing a composition for polyester resin films, a polyester resin film, and a laminated film.

Background Art

[0002] Polyester resins are used in various applications such as fibers, housings, films, beverage bottles, and packaging containers. Among them, polyethylene terephthalate (PET) is mainly used for packaging containers and films. Polyester resin films are formed by solidifying molten resin on a metal cooling roll. At this time, if the resin film does not adhere firmly to the cooling roll, wrinkles and thickness unevenness will occur in the formed resin film, resulting in poor appearance. Therefore, an electrostatic adhesion method is known in which an electric current is passed through the cooling roll or a pinning wire electrode is installed to impart charges to the cooling roll and the resin film, and the resin film is electrostatically adhered to the cooling roll.

[0003] However, in such an electrostatic adhesion method, when the rotational speed of the cooling roll is increased to increase the film formation speed, air is entrapped between the cooling roll and the resin film, resulting in bubble-like defects on the film surface. Therefore, there is a limit to increasing the film formation speed. Therefore, in order to enable further high-speedization, for example, Patent Documents 1 and 2 disclose a technique of adding a sulfonate to polyester. As a result, the volume resistivity of the molten resin decreases, so that charges can be efficiently imparted to the molten resin immediately before reaching the cooling roll, and a significant improvement in the film formation speed has been achieved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above technology, if the sulfonate is not uniformly added to the polyester resin, the electrostatic adhesion of the resin film to the cooling roll is not stable, resulting in appearance defects. Further, when adding powdery sulfonate to the polyester resin to uniformly add the sulfonate, depending on the particle diameter, sulfonate dust may be generated during work, contaminating the working environment, or the fluidity of the sulfonate may be low, making continuous supply unstable.

[0006] Therefore, the technology of the present disclosure provides a modifier for a polyester resin film that can impart excellent electrostatic adhesion to the polyester resin film and improve the workability of adding it to the polyester resin. Further, a composition for a polyester resin film, a polyester resin film, and a method for manufacturing a laminated film using the same are also provided.

Means for Solving the Problems

[0007] The present disclosure takes the following means to solve the above problems. [1] represented by the following general formula (1) A modifier for a polyester resin film containing an organic sulfonate, wherein when the total amount of the organic sulfonate is 100% by mass, the content ratio of the organic sulfonate having a particle diameter exceeding 0 μm and not exceeding 75 μm is 5% by mass or less, and the content ratio of the organic sulfonate having a particle diameter exceeding 75 μm and not exceeding 150 μm is 5% by mass or more. and the content ratio of the organic sulfonate having a particle diameter of more than 150 μm and 1000 μm or less is 79.6% by mass or more and 95% by mass or less A modifier for a polyester resin film, characterized by the above.

Chemical

[0008] In this specification, the numerical range indicated by "A to B" represents a range including its upper and lower limits. That is, "A to B" means "not less than A and not more than B".

Advantages of the Invention

[0009] According to the present disclosure, it is possible to provide a modifier for a polyester resin film that can impart excellent electrostatic adhesion to the polyester resin film and improve the workability of addition to the polyester resin. Further, it is possible to provide a method for producing a composition for a polyester resin film, a polyester resin film, and a laminated film using the same.

Embodiments for Carrying Out the Invention

[0010] ≪Modifier for Polyester Resin Film≫ The modifier for polyester resin film (hereinafter also referred to as "modifier") is a powdery or granular solid containing an organic sulfonate. By incorporating the modifier into the polyester resin film, excellent electrostatic adhesion can be imparted to the film.

[0011] <Organic sulfonate> As the organic sulfonate, has the structure described later Any compound that can improve the electrostatic adhesion of the polyester resin film may be used, and it may be used alone or in combination of two or more. However, the organic sulfonate needs to maintain the content ratio of the particle size described later until the addition operation to the polyester resin.

[0012] Organic sulfonate is The compound represented by the following general formula (1) is . [Chemical formula] (In general formula (1), X is the residue obtained by removing three hydrogen atoms from benzene, R 1 and R 2 are a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and M is an alkali metal atom or a phosphonium compound.) Examples of the compound represented by general formula (1) include sodium 3,5-dicarboxybenzenesulfonate, tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate, sodium 3,5-bis(methoxycarbonyl)benzenesulfonate, tetrabutylphosphonium 3,5-bis(ethoxycarbonyl)benzenesulfonate, sodium 3,5-bis(propoxycarbonyl)benzenesulfonate, tetrabutylphosphonium 3,5-bis(butoxycarbonyl)benzenesulfonate, tetrabutylphosphonium 3,5-bis(pentyloxycarbonyl)benzenesulfonate, and sodium 3,5-bis(hexyloxycarbonyl)benzenesulfonate. Among them, as the organic sulfonate, in general formula (1), R 1 and R 2Particularly preferred is tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate in which R is a hydrogen atom and M is a phosphonium compound.

[0013] <Particle size of organic sulfonate> When the total amount of the organic sulfonate contained in the modifier is 100% by mass, The content ratio of the organic sulfonate having a particle diameter of more than 150 μm and 1000 μm or less is 79.6% by mass or more and 95% by mass or less. Also the content ratio of the organic sulfonate having a particle size exceeding 0 μm and not exceeding 75 μm is 5% by mass or less, preferably 2% by mass or less. By adjusting the content of the particles having a particle size exceeding 0 μm and not exceeding 75 μm within this range, dust generated during the addition of the modifier to the polyester resin can be effectively suppressed, and contamination of the working environment can be reduced.

[0014] Also, when the total amount of the organic sulfonate contained in the modifier is 100% by mass, the content ratio of the organic sulfonate having a particle size exceeding 75 μm and not exceeding 150 μm is 5% by mass or more. By adjusting the content of the particles having a particle size exceeding 75 μm and not exceeding 150 μm within this range, the fluidity of the organic sulfonate is maintained at a desired level, and continuous supply of the modifier using a feeder or the like can be stably performed. Thus, by adjusting the content ratios of the particles having a particle size exceeding 0 μm and not exceeding 75 μm and the particles having a particle size exceeding 75 μm and not exceeding 150 μm of the organic sulfonate within a predetermined range, the workability when adding the modifier to the polyester resin can be improved.

[0015] Furthermore, when the total amount of the organic sulfonate contained in the modifier is 100% by mass, the content ratio of the organic sulfonate having a particle size exceeding 1000 μm is preferably 10% by mass or less, more preferably 3% by mass or less. By adjusting the content of the particles having a particle size exceeding 1000 μm within this range, the flow of the modifier from a feeder or the like becomes uniform, and the supply of the modifier to the polyester resin can be further stabilized. The particle size of the organic sulfonate can be measured using a particle size distribution measuring device using the laser diffraction / scattering method or a test sieve of JIS Z 8801-1:2019.

[0016] <Ethanol-insoluble content> The modifier may contain impurities generated during the synthesis of organic sulfonates. For example, when the modifier contains ethanol-insoluble matter, the ethanol-insoluble matter in the modifier is preferably 100 μg / g or less, and more preferably 50 μg / g or less. By adjusting the ethanol-insoluble matter within this range, it is possible to suppress appearance defects such as a decrease in the transparency of the polyester resin film due to the ethanol-insoluble matter and the formation of spots in the film (mixing of visible foreign substances). The ethanol-insoluble matter can be measured, for example, in accordance with the soap test method of JIS K3304:2019.

[0017] <Iron element> Similarly, the iron element contained in the modifier is preferably 50 ppm or less, and more preferably 10 ppm or less. By adjusting the content of the iron element within the above range, it is possible to prevent the modifier from being colored, for example, red, due to the iron element.

[0018] ≪Composition for polyester resin film≫ Next, the composition for a polyester resin film will be described. The composition for a polyester resin film contains a polyester resin and a modifier, and includes a masterbatch containing a high-concentration modifier and intermediate products in the manufacturing process of the polyester resin film described later. The organic sulfonate in the modifier dissolves in the polyester resin when melt-kneaded with the polyester resin. Therefore, in the composition for a polyester resin film and the polyester resin film described later, the particle diameter and the content ratio of the organic sulfonate are not maintained within the above range.

[0019] <Polyester resin> As the polyester resin, a resin having a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol as a basic constituent can be used, and known ones can be used. There is no particular limitation on the polyvalent carboxylic acid. For example, aliphatic or alicyclic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dimer acid, dodecanedioic acid, 1,6-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, etc. can be mentioned. As the above polyvalent carboxylic acid, one kind or a mixture of two or more kinds thereof can be used. On the other hand, there is no particular limitation on the polyhydric alcohol. For example, aliphatic or alicyclic diol units such as 1,2-ethanediol, 2,2'-oxydiethanol, 2,2'-(ethylenedioxy)diethanol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, isosorbide, xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis(4'-hydroxyphenyl)propane, 2,2-bis(4'-β-hydroxyethoxyphenyl)propane, bis(4-hydroxyphenyl)sulfone, bis(4-β-hydroxyethoxyphenyl)sulfone, etc. can be mentioned. As the above polyhydric alcohol, one kind or a mixture of two or more kinds thereof can be used. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, polylactic acid, polyhydroxybutyric acid, polyethylene naphthalate, polyarylate, acid-modified polyester copolymerized with isophthalic acid, glycol-modified polyester (PET-G) copolymerized with 1,4-cyclohexanedimethanol, etc. Also, the polyester resin may be used alone or in combination of two or more kinds.

[0020] The composition for polyester resin film may further contain additives as required. Examples of the additives include antioxidants, antistatic agents, ultraviolet absorbers, infrared absorbers, antiblocking agents, anti-coloring agents, deodorants, antioxidants, crystal nucleating agents, heat stabilizers, flame retardants, lubricants, and the like. The additives may be used alone or in combination of two or more kinds.

[0021] Note that the content of the modifier in the composition for polyester resin film is not particularly limited and can be appropriately set according to the type of the composition for polyester resin film and the type of the modifier. For example, when the composition for polyester resin film is a masterbatch, it is preferable that the modifier is 0.1 to 12 parts by mass with respect to 100 parts by mass of the polyester resin. On the other hand, when the composition for polyester resin film is an intermediate product in the manufacturing process of the resin film, the content of the modifier can be arbitrarily changed according to the manufacturing process. However, the composition for polyester resin film immediately before being formed into a film preferably contains 0.01 to 10 parts by mass, more preferably 0.01 to 1 part by mass, of the modifier with respect to 100 parts by mass of the polyester resin.

[0022] <Polyester resin film> Next, the polyester resin film will be described. The polyester resin film is obtained by forming a molding composition containing a polyester resin and a modifier into a film shape. The polyester resin film can exhibit excellent electrostatic adhesion by containing an organic sulfonate.

[0023] The polyester resin film preferably contains 0.01 to 10 parts by mass, more preferably 0.01 to 1 part by mass, of the modifier with respect to 100 parts by mass of the polyester resin. Also, the film thickness of the polyester resin film is not particularly limited, but is preferably 10 to 300 μm.

[0024] <Laminated film> The laminated film is a laminated film of two or more layers, having the above-described polyester resin film as at least one of the surface layers. The other layers of the laminated film are formed of a thermoplastic resin, an adhesive, an anchor coating agent, an adhesive resin, or the like. Examples of the thermoplastic resin include polyolefin resins, polyesters such as polyethylene terephthalate, polyamides such as nylon 6, polyvinyl alcohol, polystyrene, acrylic resins such as polymethyl methacrylate, and the like. As the thermoplastic resin, the same polyester resin as the material contained in the polyester resin film can also be used. Additives can also be contained in the thermoplastic resin for a specific purpose. Examples of the additives include ultraviolet absorbers, infrared absorbers, antiblocking agents, antistatic agents, antifogging agents, heat stabilizers, neutralizing agents, plasticizers, lubricants, flame retardants, crystal nucleating agents, and the like.

[0025] The total film thickness of the laminated film is not particularly limited, but is preferably 10 to 300 μm. Further, in the laminated film, the ratio of the film thickness of the polyester resin film layer laminated on one side to the film thickness of the other layers other than the polyester resin film layer can be set as appropriate, but is preferably 5:90 to 20:60.

[0026] ≪Manufacturing Method≫ Next, the manufacturing methods of the composition for polyester resin film, the polyester resin film, and the laminated film will be described.

[0027] <Manufacturing Method of Composition for Polyester Resin Film> The manufacturing method of the composition for polyester resin film is roughly divided into two methods. The first method is a method of preparing a masterbatch containing a polyester resin and a high-concentration modifier in advance, and further mixing this masterbatch with a polyester resin to produce a molding composition. In this specification, the "molding composition" means a composition containing the composition for polyester resin film and is a composition used in the film molding process.

[0028] The production of masterbatch can use conventionally known methods and is not particularly limited. As methods for producing masterbatch, for example, a polyester-based resin is melted by an extruder such as a single-screw extruder or a multi-screw extruder, and a modifier is added to the extruder by side feeding or the like, and granulated while melt-kneading. Also, a polyester-based resin and a modifier are previously put into a mixer such as a tumbler blender, a super mixer, or a Henschel mixer and mixed, and then added to an extruder such as a single-screw extruder or a multi-screw extruder using a feeder or the like, and the masterbatch is granulated while the mixture is melt-kneaded by the extruder. Furthermore, it is also possible to add a polyester resin to an extruder such as a single-screw extruder or a multi-screw extruder using a main feeder or the like, add a modifier to the extruder by a sub-feeder or the like, and granulate the masterbatch while melt-kneading.

[0029] The production of a molding composition using masterbatch can also use conventionally known methods and is not particularly limited. For example, in the above-described method for producing masterbatch, a molding composition can be produced by using masterbatch instead of the modifier and omitting the granulation step.

[0030] The second method is a method of directly producing a molding composition containing a composition for a polyester-based resin film by mixing a polyester-based resin and a modifier. The second method can also use conventionally known methods and is not particularly limited. Examples of the second method include, for example, a method in which the granulation step is omitted in the above-described method for producing masterbatch.

[0031] In the method for producing a composition for a polyester resin film, the mixing ratio of the modifier with respect to the polyester resin can be appropriately set according to the type of the composition for a polyester resin film and the type of the modifier. For example, it is preferable to mix 0.01 to 12 parts by mass of the modifier with respect to 100 parts by mass of the polyester resin. Specifically, when producing a masterbatch, it is preferable to mix 0.1 to 12 parts by mass of the modifier with respect to 100 parts by mass of the polyester resin. On the other hand, when directly producing a molding composition containing the composition for a polyester resin film, it is preferable to mix 0.01 to 10 parts by mass of the modifier with respect to 100 parts by mass of the polyester resin, and more preferably 0.01 to 1 part by mass.

[0032] <Method for Producing Polyester Resin Film> The polyester resin film is produced by forming a molten molding composition into a film shape by a known film-forming method. Examples of the film-forming method include inflation molding such as air-cooled inflation molding, air-cooled two-stage inflation molding, air-cooled three-stage inflation molding, and water-cooled inflation molding, and T-die molding using a straight manifold type, a coat hanger type, or a combination thereof as the T-die. Further, the film may be stretched, and examples of the stretching method include a tenter simultaneous biaxial stretching method, a sequential biaxial stretching method using a roll and a tenter, and a biaxial stretching method by an inflation method.

[0033] <Method for Producing Laminated Film> The laminated film is manufactured by laminating a polyester resin film as at least one of the surface layers of two or more laminated films by a known film forming method. Examples of the film forming method include a dry lamination method, a sand lamination method, an extrusion lamination method, a coextrusion method, etc. When manufacturing a laminated film by a dry lamination method, a sand lamination method, or an extrusion lamination method, known polyurethane adhesives, organic titanium anchor coat agents, isocyanate anchor coat agents, adhesive resins, etc. can be used. In the production by the coextrusion method, inflation molding and T-die molding can be used, and either an un-stretched or stretched molding method by a stretching method can be used.

Example

[0034] Hereinafter, the configuration and effects of the present disclosure will be described more specifically based on examples. In the following examples and comparative examples, "parts" means parts by mass.

[0035] Preparation Example 1 3,5-dicarboxybenzenesulfonic acid tetrabutylphosphonium salt (A-1) as an organic sulfonate was separated into four types of over 0 μm and 75 μm or less, over 75 μm and 150 μm or less, over 150 μm and 1000 μm or less, and over 1000 μm using a JIS test sieve, and mixed by dry blending so as to have the ratios (mass %) described in Table 1 below to prepare a modifier (K-1) for a polyester resin film.

[0036] Preparation Examples 2 to 10 Modifiers (K-2 to K-6, k-1 to k-4) for a polyester resin film were prepared in the same manner as in Preparation Example 1, except that the type of the organic sulfonate and the ratio of each particle size were changed as shown in Table 1 below.

[0037]

Table 1

[0038] Example 1-1 95 parts of polyethylene terephthalate (trade name "RAMAPET N-1", manufactured by Indorama Ventures Public Company Limited) as a polyester resin and 5 parts of the modifier (K-1) obtained in Preparation Example 1 were supplied to a coaxial twin-screw kneading extruder using a feeder, melt-kneaded at 250 to 290 °C, extruded from a strand die, and quenched with water to obtain strands. These strands were cut with a pelletizer to prepare a masterbatch (N-1) which is a composition for a polyester resin film.

[0039] Examples 1-2 to 1-6, Comparative Examples 1-1 to 1-4 Masterbatches (N-2 to N-6, n-1 to n-4) were prepared in the same manner as in Example 1-1, except that the type and blending ratio of the modifier were changed as shown in Table 2 below.

[0040] [Table 2]

[0041] <Evaluation of Masterbatch (MB) Productivity> The productivity when preparing the masterbatch was evaluated based on the following criteria. The evaluation results are shown in Table 2. [Evaluation Criteria] 3: The organic sulfonate could be stably supplied, there was no device contamination, and stable production for 24 hours was possible. 2: The organic sulfonate could be stably supplied, there was no device contamination, and stable production for 8 hours was possible. 1: The organic sulfonate could not be stably supplied and / or the equipment was contaminated, and stable production could not be achieved for 8 hours.

[0042] Example 2-1 99.5 parts of polyethylene terephthalate (trade name "RAMAPET N-1") as a polyester resin and 0.5 part of a masterbatch (N-1) were supplied to a coaxial twin-screw kneading extruder using a feeder and melt-kneaded at 260 to 280°C. Subsequently, using a multi-manifold T-die, while adjusting the supply amount of the molten resin and the screw rotation speed, it was wound up on a cooling roll whose temperature was adjusted to 30°C to obtain an unstretched film. The obtained unstretched film was stretched 3 times longitudinally and 4 times transversely at 110°C, then heat-treated at 235°C, and gradually cooled to room temperature to obtain a polyester resin film (F-1) with a thickness of 60 μm.

[0043] Examples 2-2 to 2-6, Comparative Examples 2-1 to 2-4 Except that the type and blending ratio of the masterbatch and the presence or absence and film thickness of the biaxial stretching treatment of the polyester resin film were changed as shown in Table 3 below, polyester resin films (F-2 to F-6, f-1 to f-4) were obtained in the same manner as in Example 2-1. When biaxial stretching was not performed, the steps up to the step of obtaining the unstretched film in Example 2-1 were carried out.

[0044]

Table 3

[0045] <Evaluation of Electrostatic Adhesion> In the production of the polyester resin film, when the melt-kneaded product of the masterbatch and the polyester resin was extruded into a film shape and cast on a cooling roll, it was applied with a pinning wire (voltage 10 KV) installed above the extruded film and adhered to the cooling roll. The electrostatic adhesion at that time was evaluated based on the following criteria. The evaluation results are shown in Table 3. [Evaluation Criteria] 3: Film formation can be stably achieved at a speed of 80 m / min or more of the cooling roll. 2: A stable film can be formed when the speed of the cooling roll is 50 m / min or more and less than 80 m / min. 1: A stable film can be formed only when the speed of the cooling roll is less than 50 m / min.

[0046] Example 3-1 99.5 parts of polyethylene terephthalate (trade name "RAMAPET N-1") as a polyester resin and 0.5 part of a masterbatch (N-1) were supplied to a first coaxial twin-screw kneading extruder using a feeder and melt-kneaded at 260 to 280°C. On the other hand, only polyethylene terephthalate (trade name "RAMAPET N-1") as a polyester resin was supplied to a second coaxial twin-screw kneading extruder and melt-kneaded at 260 to 280°C. Next, using a multi-manifold T-die, while adjusting the supply amount of the molten resin and the screw rotation speed, co-extrusion was performed such that the layer made of the molten resin of the first coaxial twin-screw kneading extruder was on both surface layers and the layer made of the molten resin of the second coaxial twin-screw kneading extruder was in the intermediate layer, and it was wound up on a cooling roll adjusted to 30°C to obtain a laminated unstretched film with a thickness ratio of A layer (one surface layer), B layer (intermediate layer), and A layer (the other surface layer) of 10:80:10. The obtained laminated unstretched film was stretched 3 times longitudinally and 4 times laterally at 110°C, then heat-treated at 235°C, and slowly cooled to room temperature to obtain a laminated film with a thickness of 60 μm.

[0047] Examples 3-2 to 3-7, Comparative Examples 3-1 to 3-4 Except that the type and blending ratio of the masterbatch in the A layer and B layer, and the presence or absence of the biaxial stretching treatment, the total film thickness, and the ratio of the A layer to the B layer of the laminated film were changed as shown in Table 4 below, each laminated film was obtained in the same manner as in Example 3-1. Note that the A layer of each laminated film used the same raw materials as the corresponding polyester resin film in Table 3 to have the same component composition. Also, when biaxial stretching was not performed, the process up to obtaining the laminated unstretched film in Example 3-1 was carried out.

[0048]

Table 4

[0049] <Evaluation of Electrostatic Adhesion of Laminated Film> In the production of the laminated film, when two types of molten resins were co-extruded into a laminated film and cast on a cooling roll, a pinning wire (voltage: 10 kV) installed above the extruded film was used to apply voltage and make it adhere to the cooling roll. The electrostatic adhesion at that time was evaluated based on the following criteria. The evaluation results are shown in Table 4. [Evaluation Criteria] 3: A stable film can be formed at a cooling roll speed of 80 m / min or more. 2: A stable film can be formed at a cooling roll speed of 50 m / min or more and less than 80 m / min. 1: A stable film can be formed only at a cooling roll speed of less than 50 m / min.

[0050] In Examples 1-1 to 1-6, the workability of adding the modifier to the polyester resin in the production of the masterbatch was good, and the productivity of the masterbatch was high. Also, the polyester resin films of Examples 2-1 to 2-6 and the laminated films of Examples 3-1 to 2-6 produced using the masterbatches of Examples 1-1 to 1-6 showed excellent electrostatic adhesion. On the other hand, in Comparative Example 1-1, since the proportion of the particle size of the organic sulfonate contained in the modifier being more than 0 μm and 75 μm or less was too large, the workability of adding the modifier to the polyester resin was poor, and the productivity of the masterbatch was low. In Comparative Examples 1-2 and 1-4, since the proportion of the particle size of the organic sulfonate contained in the modifier being more than 75 μm and 150 μm or less was too small, the addition of the modifier to the polyester resin was unstable, and the productivity of the masterbatch was low. However, the polyester resin films of Comparative Examples 2-1, 2-2, and 2-4 and the laminated films of Comparative Examples 3-1, 3-2, and 3-4 produced using the masterbatches obtained in Comparative Examples 1-1, 1-2, and 1-4 showed good electrostatic adhesion. In Comparative Example 1-3, the productivity of the masterbatch was high. However, since the modifier contained diglycerin monostearate instead of the organic sulfonate, the polyester resin film of Comparative Example 2-3 and the laminated film of Comparative Example 3-3 produced using the masterbatch obtained in Comparative Example 1-3 had poor electrostatic adhesion.

Claims

A modifier for a polyester resin film containing an organic sulfonate represented by the following general formula (1), when the total amount of the organic sulfonate is 100% by mass, the content ratio of the organic sulfonate having a particle size exceeding 0 μm and not exceeding 75 μm is 5% by mass or less, the content ratio of the organic sulfonate having a particle size exceeding 75 μm and not exceeding 150 μm is 5% by mass or more, and the content ratio of the organic sulfonate having a particle size exceeding 150 μm and not exceeding 1000 μm is 79.6% by mass or more and 95% by mass or less. A modifier for a polyester resin film characterized by the above. 【Chemical 1】 (In general formula (1), X is a residue obtained by removing three hydrogen atoms from benzene, R1 and R2 are a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and M is an alkali metal atom or a phosphonium compound.)

2. The modifier for a polyester resin film according to claim 1, wherein when the total amount of the organic sulfonate is 100% by mass, the content ratio of the organic sulfonate having a particle size exceeding 1000 μm is 10% by mass or less.

3. R in the general formula (1) １ and R ２ are hydrogen atoms, and M is tetrabutylphosphonium. The modifier for a polyester resin film according to claim 1.

4. A method for producing a composition for a polyester resin film, characterized in that 0.01 to 12 parts by mass of the modifier for a polyester resin film according to claim 1 or 2 is mixed with 100 parts by mass of the polyester resin.

5. A method for producing a polyester resin film, characterized in that a molding composition containing the composition for a polyester resin film obtained by the production method according to claim 4 is molded.

6. A method for producing a laminated film having two or more layers, characterized in that a polyester resin film obtained by the production method according to claim 5 is laminated as at least one of the surface layers. A method for producing a laminated film.

Images