JP2007002115A - Polymer composition and biaxially oriented film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biaxially oriented film which, while composed mainly of a polyester, has excellent heat resistance and resistance to moist heat compared with the conventional polyester film and has little oligomers. <P>SOLUTION: The polymer composition is composed mainly of a polyester composition, contains 0.1-5 pts.wt. of a composition containing a polyolefin having a carboxylic acid group on the side chain, based on 100 pts.wt. of the polymer composition, contains 1-50 mol/ton of a metal element selected from among Li, Na and K based on the weight of the polymer composition, and has 0.1-0.6 pt.wt. of an ester cyclic trimer content based on 100 pts.wt. of the polymer composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to improvement of a polymer composition and a biaxially stretched film, and more particularly to a polymer composition and a biaxially oriented film having excellent moist heat resistance, heat resistance and low oligomer properties. This film can be widely used for various industrial materials such as electrical insulation, capacitors, packaging, ink ribbons, circuit boards and the like, and is particularly suitable as an electrical insulation film.

  Polyester film uses various properties such as magnetic recording media, electrical insulation, capacitors, packaging, various industrial materials, etc. by utilizing excellent mechanical properties, thermal properties, electrical properties, surface properties, and heat resistance. Used for applications. In the improvement of the quality of these uses, improvement in dimensional stability, heat resistance, and heat and humidity resistance especially in a high temperature environment is required. However, a polyester film made of ethylene terephthalate alone (hereinafter referred to as PET) has insufficient dimensional stability, heat resistance, and heat and moisture resistance under high temperature environments, and has excellent dimensional stability, heat resistance, and heat and moisture resistance. Polyethylene-2,6-naphthalate (hereinafter referred to as PEN) has low processability, such as being easily broken, and its application is limited at present, and improvement of these problems is strongly desired. In electrical insulation applications such as compressor motors, the refrigerant and insulating film are in direct contact with each other, making it easy to extract oligomers and requiring heat resistance and heat and humidity resistance, as well as containing oligomers mainly composed of ester cyclic trimers. There is a need for films with low amounts.

  For the purpose of modifying polyester, methods for kneading and alloying ionomers have been widely proposed. The ionomer is a generic term for polymer metal salts having acidic groups such as carboxylic acid groups and sulfonic acid groups in the polymer side chain, and a part or all of these are metal salts.

In Patent Document 1, 20 to 50 parts by weight of a metal salt of a polymer obtained by copolymerizing 1 to 30 mol% of an unsaturated carboxylic acid with respect to polyethylene terephthalate or polybutylene terephthalate is blended to improve impact resistance and hydrolysis resistance. Technology is disclosed. Patent Document 2 discloses a polybutylene terephthalate resin composition containing polybutylene terephthalate and a metal salt of an organic polymer having a carboxyl group in a side chain in a proportion of 10 to 50% by weight based on the total weight of the composition. Proposed. However, in these inventions, since the amount of ionomer added is too large, not only the heat and moisture resistance but also the heat resistance is insufficient, and the synergistic effect of blending these ionomers with polyesters with reduced oligomer content. There was no disclosure of the effect of improving hydrolysis resistance by.
JP-A 61-243855 JP-A-6-145486

  This invention makes it a subject to obtain the polyester composition and biaxially oriented film which have the heat-and-moisture resistance and heat resistance outstanding with respect to the conventional polyester composition, although polyester is a main structural component.

  The above-mentioned problem is selected from 0.1 to 5 parts by weight, Li, Na, and K based on 100 parts by weight of the whole polymer composition of a polyolefin-containing composition having a polyester composition as a main component and having a carboxylic acid group in the side chain. The metal element is contained in an amount of 1 to 50 mol / ton relative to the weight of the polymer composition, and the ester cyclic trimer content is 0.1 to 0.6 parts by weight based on 100 parts by weight of the whole polymer composition. It is achieved by the polymer composition for molded articles.

Moreover, the polymer composition of the present invention comprises:
(1) A salt in which at least part or all of the carboxylic acid group in the polyolefin-containing composition having a carboxylic acid group in the side chain is part or all of at least one metal element selected from Li, Na, and K. Forming.
(2) The polyolefin-containing composition having a carboxylic acid group in the side chain is a copolymer of ethylene and an unsaturated carboxylic acid.
(3) The polyolefin-containing composition having a carboxylic acid group in the side chain is a copolymer of styrene and aromatic vinyl.
(4) The polyolefin-containing composition having a carboxylic acid group in the side chain contains a saturated and / or unsaturated cycloalkylene structure.
(5) The polyester composition is polyethylene terephthalate.
(6) The polyester composition is polyethylene-2,6-naphthalate.
The biaxially stretched film of the present invention has (1) a breaking elongation retention half-life of 20 hours or more in a moist heat resistance test.
(2) The breaking elongation retention half-life in the heat resistance test is 15 hours or more.
(3) Being for electrical insulation,
Are included as preferred embodiments.

  According to the present invention, a biaxially oriented film having excellent moisture and heat resistance and low oligomer content can be provided, and its industrial value is extremely high.

  Hereinafter, embodiments of the present invention will be described in detail.

  The polyester used in the present invention is a polymer obtained by condensation polymerization of a diol and a dicarboxylic acid or an ester-forming derivative thereof. Here, the dicarboxylic acid is represented by terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like. These ester-forming derivatives are compounds typified by dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalenedicarboxylate, and the like. The diol is represented by ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, cyclohexanedimethanol and the like.

  Specific polymers include, for example, polymethylene terephthalate, polyethylene terephthalate, polyethylene isophthalate, polypropylene terephthalate, polytetramethylene terephthalate, polyethylene-p-oxybenzoate, poly-1,4-cyclohexylenedimethylene terephthalate, polyethylene-2. , 6-Naphthalate can be used, and polyethylene terephthalate and polyethylene naphthalate can be preferably used from the viewpoint of heat resistance.

  Of course, these polyesters may be a homopolymer or a copolymer. In the case of a copolymer, examples of copolymer components include diol components such as diethylene glycol, neopentyl glycol, and polyalkylene glycol, adipic acid, and sebatin. It may contain dicarboxylic acid components such as acid, phthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid, and hydroxycarboxylic acid components such as hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. The content of these copolymer components is preferably 10 mol% or less with respect to all dicarboxylic acid components or diol components.

  Among these, in the case of the present invention, at least one of polyethylene terephthalate, polyethylene-2,6-naphthalate and copolymers and modified products thereof is preferably used.

  There is no restriction | limiting in particular in the manufacturing method of polyester in this invention, It can manufacture by a conventionally well-known melt polymerization. That is, it can be produced by a direct polymerization method or a transesterification method, and can be produced by a batch method or a continuous polymerization method.

  The catalyst for producing the polyester of the present invention is not particularly limited, and a conventionally known catalyst can be used. Effective catalysts for transesterification include alkali metal or alkalinity metal compounds such as calcium acetate, magnesium acetate, lithium acetate, and sodium acetate, as well as manganese acetate, cobalt acetate, zinc acetate, tin acetate, and alkoxide titanium. Can be used. As the polymerization catalyst, composite oxides containing aluminum, silica, titanium and the like as constituent components can be used in addition to antimony trioxide, germanium dioxide, alkoxide titanium, and the like. Moreover, it is preferable to add various phosphorus compounds, such as phosphoric acid, phosphorous acid, and a trimethyl phosphate, as a stabilizer. The phosphorus compound is preferably added at the beginning of the polycondensation reaction after the esterification reaction or after the transesterification reaction.

  The polyester in the present invention can contain various inert particles for the purpose of imparting easy slipperiness to the film. These inert particles include wet or dry silica, colloidal silica, alumina, titania, zirconia, aluminum silicate, zinc oxide, copper oxide, inorganic oxide particles, gold, silver, copper, iron, platinum and other inorganic metals Examples thereof include particles, organic particles represented by crosslinked polystyrene, crosslinked divinylbenzene, and other particles such as calcium carbonate, calcium phosphate, hydroxyapatite, and barium sulfate. From the viewpoint of improving dispersibility, these particles are preferably added to the reaction system before shifting to an arbitrary step in the polycondensation of the polyester, preferably from the oligomer to the polycondensation step. Further, it is preferable that the particles are added using water or a polyester monomer compound such as ethylene glycol as a dispersion medium. Further, these particles may be kneaded and dispersed in a polyester obtained in advance using a twin screw extruder with a vent hole. Moreover, you may contain what is called an internal particle produced | generated in the polycondensation process resulting from the polycondensation catalyst of polyester.

  Moreover, the polyester of this invention can add various additives, such as antioxidant, a ultraviolet absorber, a flame retardant, a lubricating agent, and a coloring agent, in the range which does not impair the physical property of polyester and the film of this invention.

  The polyester composition of the present invention contains a polyolefin-containing composition having a carboxylic acid group in the side chain in an amount of 0.1 to 5 parts by weight, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the entire polymer composition. Parts, more preferably 0.5 to 2 parts by weight. When the content is less than 0.1, sufficient wet heat resistance cannot be expressed. When the content exceeds 5, the heat resistance is poor.

  Examples of the polyolefin-containing composition having a carboxylic acid group in the side chain include polyacrylic acid, poly (ethylene-acrylic acid) copolymer, poly (ethylene-methacrylic acid) copolymer, and poly (propylene-acrylic acid) copolymer. Polymers, poly (styrene-acrylic acid) copolymers, poly (styrene-methacrylic acid) copolymers, poly (styrene-vinylbenzoic acid) copolymers, etc. can be used, among which poly (ethylene-acrylic) Acid) copolymer, poly (ethylene-methacrylic acid) copolymer, and poly (styrene-vinylbenzoic acid) copolymer are preferable, and poly (styrene-vinylbenzoic acid) copolymer is more preferable in terms of heat resistance. It is a coalescence.

  Moreover, the aspect in which the polyolefin containing composition which has a carboxylic acid group in the side chain in this invention contains the saturated and / or unsaturated cycloalkylene structure is further more preferable. By containing a cycloalkylene structure, the heat resistance can be further improved. The content of the cycloalkylene structure is not particularly limited, but the higher the content, the better the heat resistance. The monomer that constitutes a part or all of the polymer is preferably a substituted and unsubstituted bicyclic or higher polycyclic norbornene. Specific monomers include, for example, 2-norbornene, 5 -Methyl-2-norbornene, 5,6-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-octyl-2-norbornene, 5 -Bicyclic norbornene such as dodecyl-2-norbornene, tricyclic norbornene such as dicyclopentadiene (DCP), dihydrodicyclopentadiene, tetracyclododecene, methyltetracyclododecene, ethyltetracyclododecene, dimethyltetracyclodone Tetracyclic norbornene such as decene, tricyclopen Diene compounds polycyclic norbornene or a portion of these hydrocarbon group or pentacyclic such as such as tetra cyclopentadiene substituted with a carboxylic acid group. Among these norbornene-based monomers, tricyclic to pentacyclic norbornene is preferable. A polyolefin-containing composition having a carboxylic acid group in the side chain is constituted by copolymerizing the above-mentioned monomers such as ethylene, acrylic acid, methacrylic acid, styrene, vinyl benzoate with the cycloalkylene group-containing monomer. May be. Moreover, you may introduce | transduce a carboxylic acid group after superposition | polymerization using the remaining double bond.

  The polymer composition of the present invention contains 1 to 50 mol / ton, preferably 3 to 30 mol / ton, more preferably 5 to 20 mol of a metal element selected from Li, Na and K with respect to the weight of the polymer composition. / Ton. If the amount of the metal element is less than 1 mol / ton, sufficient wet heat resistance cannot be obtained. When the amount of metal element exceeds 50 mol / ton, the heat resistance deteriorates.

  In the present invention, part or all of the carboxylic acid group contained in the polyolefin-containing composition having a carboxylic acid group in the side chain is a part or all of at least one metal element selected from Li, Na, and K. It is preferable to form a salt. Metal elements other than Li, Na, and K cannot exhibit sufficient heat and humidity resistance.

  The polyolefin-containing composition having a carboxylic acid group in these side chains contains a monomer having a carboxylic acid as a constituent component as described above. The amount of copolymerization of the monomer having carboxylic acid is not particularly limited, but is preferably about 1 to 50 mol% from the viewpoint of heat resistance.

  The contents of Li, Na, K contained in the polyolefin-containing composition having a carboxylic acid group in the side chain and a salt of a carboxylic acid and a metal element selected from Li, Na, K are particularly limited. Although it is not a thing, it is preferable that it is the range of 500-2000 mol / t with respect to a polymer composition.

  A method for producing a polyolefin-containing composition having a carboxylic acid group in the side chain and a salt of a carboxylic acid and a metal element selected from Li, Na, and K is not particularly limited. It is preferable to supply the polymer and the salt of Li, Na, and K to a single-screw or twin-screw kneader / extruder so that the mixing ratio thereof is a predetermined amount, and melt knead. As salts of Li, Na, and K, respective carbonates, acetates, oxalates, chlorides, and the like can be used.

  The polymer cyclic composition of the present invention has an ester cyclic trimer content of 0.1 to 0.6 parts by weight, preferably 0.2 to 0.5 parts by weight, based on 100 parts by weight of the polymer composition. . When the ester cyclic trimer content is less than 0.1 parts by weight, the productivity is poor. When the ester cyclic trimer content exceeds 0.6 parts by weight, for example, when used for an electrical insulating film such as a compressor, a rocking phenomenon is caused by an oligomer mainly composed of the extracted ester cyclic trimer. This is not preferable because it becomes easy and the heat-and-moisture resistance is poor.

  The ester cyclic trimer is a cyclic oligomer composed of three polyester monomer units. For example, when the polyester is polyethylene terephthalate, it refers to an ethylene terephthalate cyclic trimer. As a method for reducing the content of the ester cyclic trimer, extraction with a solvent or the like is possible. However, the most preferable method is to use polyester obtained by melt polymerization under reduced pressure of 133 Pa or less or inert such as nitrogen. In a gas atmosphere, it is preferable to carry out solid phase polymerization by heat treatment at a temperature not lower than the crystallization temperature and not higher than the melting point. For example, when the polyester is polyethylene terephthalate, the temperature is preferably 180 to 250 ° C, more preferably 200 to 240 ° C. When the polyester is polyethylene-2,6-naphthalate, a range of 200 to 250 ° C. is preferable.

  The Young's modulus of the film of the present invention is preferably 3.5 GPa or more in both the longitudinal direction and the width direction, and more preferably 4.0 GPa or more in order to improve processability and reliability in use. When the film Young's modulus is less than 3.5 GPa, in addition to a decrease in general mechanical strength, for example, when used as an electrical insulating film for a compressor, the process is inferior, for example, the film is bent in the slot insertion process. .

  In obtaining a polyester composition, a polyolefin-containing composition having a carboxylic acid group in the side chain, and a film containing a metal element selected from Li, Na, and K in a desired weight fraction, these resins are dried, The resin and the metal elements of Li, Na, and K may be weighed so as to have a desired content, and supplied to the melt extruder and kneaded to produce an unstretched film directly, but these components are more uniform. In order to obtain a dispersed film, a polyester composition, a polyolefin-containing composition having a carboxylic acid group in the side chain, and a metal salt are blended in advance, and master pellets are produced using a melt kneader. Polyolefin pellets containing a carboxylic acid group in the chain and a polyester pellet so that the metal content is a desired value. Diluted with bets, it is preferable to obtain a biaxially oriented film of the present invention.

  As a method for obtaining this master pellet, a polyester composition, a polyolefin-containing composition having a carboxylic acid group in the side chain, and a metal element salt selected from Li, Na, and K are respectively weighed and kneaded to obtain a master pellet. A method or a polyolefin-containing composition having a carboxylic acid group in the side chain and a metal element salt selected from Li, Na and K are previously melt-kneaded to prepare pellets, which are further diluted with polyester to obtain master pellets. Although the method to create can be considered, the latter method is more preferable from a viewpoint of the dispersibility of a metal element.

The production method of the master pellet will be described below by taking as an example the case of using an ethylene-methacrylic acid copolymer as the polyolefin-containing composition having a carboxylic acid group in the side chain and Na as the metal element. An ethylene-methacrylic acid random copolymer polymerized and dried according to a conventional method and sodium carbonate are melt-kneaded at 150 ° C. to obtain an ethylene-methacrylic acid Na salt. On the other hand, the polyester composition is dried under reduced pressure at a temperature of 140 to 200 ° C. for 2 to 5 hours when the polyester composition is a crystallization temperature or higher and a melting point or lower, for example, when the polyester is polyethylene terephthalate. The moisture content after drying is preferably 50 ppm or less, more preferably 30 ppm or less. The sodium salt of the ethylene-methacrylic acid copolymer is dried at 40 to 90 ° C., preferably 50 to 80 ° C. for 6 hours or more, preferably 8 hours or more. The dried polyester chip and ethylene-methallylic acid copolymer Na salt are blended and fed to a vented twin screw extruder heated to 250 to 300 ° C. The weight fraction of the polyester and ethylene-methacrylic acid copolymer Na salt at the time of producing the master pellet is not particularly limited, but preferably the weight fraction of the ethylene-methacrylic acid copolymer Na salt is 1 to 50 weights. %, More preferably 5 to 20% by weight. However, since this kneading concentration also depends on the amount of Na metal element contained in the ethylene-methacrylic acid copolymer Na salt, the concentration is determined so that the amount of Na metal finally contained in the film becomes a desired amount. There is a need to. The screw configuration of the twin screw extruder is preferably provided with a kneading zone made of paddles, dull mages or the like. Shear rate is preferably 50~400sec ^-1, more preferably 100~300sec ^-1. When the shear rate is 50 sec ^-1 or less can not be obtained sufficiently dispersed state, when the shear rate exceeds 300 sec ^-1, not only the temperature control becomes difficult due to generation of heat-generating, cause degradation of the polymer there is a possibility. The residence time of the kneaded polymer is preferably 0.5 to 10 minutes, more preferably 1 to 5 minutes. If the residence time is less than 0.5 minutes, a sufficient dispersion state cannot be obtained, and if it exceeds 5 minutes, the polymer may be decomposed.

  After drying the master pellet and the polyester pellet obtained in this manner, the ethylene-acrylic acid copolymer Na salt in the film is added so that the ethylene-methacrylic acid copolymer and the Na metal content have a desired weight fraction. And fed to a melt extruder heated to 250 to 300 ° C., extruded into a sheet form from a T-die die provided in the extruder, and onto a casting drum cooled to 10 to 50 ° C. While rotating at a constant speed, it is solidified by an electrostatic application method to obtain an unstretched film. The obtained unstretched film is stretched in the longitudinal direction by using a circumferential speed difference between rolls by a stretching machine having a plurality of roll groups. The stretching temperature is preferably 90 to 170 ° C. The draw ratio is preferably 2 to 5 times, more preferably 2.5 to 4 times. The both ends of the film stretched in the longitudinal direction thus obtained are held with clips, and stretched in the width direction in a heated tenter. The draw ratio is preferably 2 to 5 times, more preferably 2.5 to 4.5 times. The stretching temperature is preferably 90 to 180 ° C. Moreover, after extending | stretching to the width direction, you may extend | stretch 1.01-2.5 times in the extending | stretching temperature range of 110-180 degreeC further to a longitudinal direction or the width direction.

  Moreover, it is preferable to heat-process at the temperature below melting | fusing point after extending | stretching, A more preferable temperature range is 190-245 degreeC, More preferably, it is 200-230 degreeC. The heat treatment time is preferably 1 to 30 seconds.

  Further, an intermediate cooling and relaxation treatment at 100 to 160 ° C. may be performed after the heat treatment step. The relaxation treatment magnification is preferably 2 to 10%, more preferably 4 to 9% in the width direction and / or the longitudinal direction.

  Further, the film of the present invention may be subjected to surface treatment such as coating in the stretching process to modify the surface, or various types of polymers may be laminated or laminated to form a laminated film.

Since the film of the present invention thus obtained has low oligomer properties in addition to excellent heat resistance and heat and humidity resistance, it is various for printed circuit boards, electrical insulation, capacitors, packaging, ink ribbons, process papers, etc. It is suitable as a film for industrial materials, particularly for electrical insulation.
[Methods for measuring physical properties and methods for evaluating effects]
(1) Heat resistance (half time of elongation at break)
A strip sample having a length of 200 mm and a width of 10 mm was cut out and used in the longitudinal direction of the film. In accordance with the method defined in JIS K-7127, the elongation at break was measured at 25 ° C. and 65% RH using a tensile tester. The distance between the initial pull chucks was 100 mm, and the pull speed was 300 m / min. The measurement was performed 20 times by changing the sample, and the average value (X) of the elongation at break was determined. In addition, a strip sample having a length of 200 mm and a width of 10 mm was placed in a gear oven, left in an atmosphere of 200 ° C., then naturally cooled, and this sample was subjected to a tensile test under the same conditions as described above 20 times. The average value (Y) of elongation was determined. From the average values (X) and (Y) of the obtained elongation at break, the elongation retention was determined by the following equation.
Elongation retention (%) = (Y / X) × 100
The heat treatment time until the elongation retention was 50% or less was defined as the half-life of elongation at break. The heat resistance was evaluated according to the following criteria, and ◎ and ○ were acceptable levels.
◎: The elongation half-life is 25 hours or more. ◎: The elongation half-life is 20 hours or more. ○: The elongation half-life is 15 hours or more. X: The elongation half-life is less than 15 hours.

(2) Moist heat resistance (half-life of elongation at break)
A strip sample having a length of 200 mm and a width of 10 mm was cut out and used in the longitudinal direction of the film. In accordance with the method defined in JIS K-7127, the elongation at break was measured at 25 ° C. and 65% RH using a tensile tester. The distance between the initial pull chucks was 100 mm, and the pull speed was 300 m / min. The measurement was performed 20 times by changing the sample, and the average value (X) of the elongation at break was determined. In addition, a strip sample having a length of 200 mm and a width of 10 mm was subjected to an atmosphere of 140 ° C. and 80% RH under a pressure of ² kg / cm ² using a highly accelerated life tester (Presser Cooker TPC-211 type manufactured by Tabai Espec Co., Ltd.). The sample was allowed to stand below, and then naturally cooled and dried. The sample was subjected to a tensile test under the same conditions as described above 20 times, and an average value (Y) of the elongation at break was determined. From the average values (X) and (Y) of the obtained elongation at break, the elongation retention was determined by the following equation.
Elongation retention (%) = (Y / X) × 100
The heat treatment time until the elongation retention was 50% or less was defined as the half-life of elongation at break. Wet heat resistance was evaluated according to the following criteria, and ◎ and ○ were acceptable levels.
A: The elongation half-life is 25 hours or more. O: The elongation half-life is 20 hours or more. X: The elongation half-life is less than 20 hours.

(3) Film thickness Film thickness was measured at 30 g of needle pressure using an electronic micrometer (K-312A type) manufactured by Anritsu Corporation.

(4) Intrinsic viscosity The intrinsic viscosity was calculated from the solution viscosity measured at 25 ° C in orthochlorophenol by the following formula.
ηsp / C = [η] + K [η] ² · C
Here, ηsp = (solution viscosity / solvent viscosity) −1, C is the dissolved polymer weight per 100 ml of solvent (g / 100 ml), and K is the Huggins constant (assuming 0.343). The solution viscosity and the solvent viscosity were measured using an Ostwald viscometer.

(5) Hydrolysis resistance of polymer composition A part of the melt-extruded cast film was sampled and used as a polymer composition sample. Under pressure of the polymer composition sample highly accelerated life tester (ESPEC Corp. pressure cooker TPC-211 type) using a 2 kg / cm ^2, and after standing for 4 hours in an atmosphere of RH 140 ° C. 80% After natural cooling and drying, the intrinsic viscosity was measured ([η] ₃ ). The difference Δ [η] = [η] ₀ − [η] ₃ ≦ 0.17 or less from the intrinsic viscosity ([η] ₀ ) of the sample before the treatment is regarded as an acceptable level (◯), and Δ [η]> 0 .17 was rejected (x).

(6) Ester cyclic trimer content 100 mg of polymer composition or film was dissolved in 2 ml of orthochlorophenol, measured by liquid chromatography (LC10A, manufactured by Shimadzu Corporation), and expressed as a ratio (% by weight) to the polymer.

(7) Metal amount in polymer The metal element was quantified by the atomic absorption method (AA630-13 type (manufactured by Shimadzu Corporation)) after ashing the polyester with concentrated sulfuric acid.

Reference example 1
Production of polyethylene terephthalate (PET) 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol are heated and melted at 150 ° C. in a vessel equipped with a rectifying column and a stirrer. After melting, 0.05 part by weight of magnesium acetate tetrahydrate was added with stirring, the temperature was gradually raised to 240 ° C., and methanol was distilled off to obtain a low molecular weight product. After adding 0.02 part by weight of trimethyl phosphate, 0.04 part by weight of antimony trioxide and 0.5 part by weight of colloidal silica (Nissan Chemical Co., Ltd.) having an average particle diameter of 20 nm, 290 ° C. The temperature inside the reaction vessel was gradually reduced while the temperature was raised to 133 Pa or less. Thereafter, a polycondensation reaction is carried out while distilling off ethylene glycol and water, and after reaching a predetermined stirring torque, it is discharged in a gut shape, cooled in a water tank, and then cut into gut shapes, and [η] = 0. 56 g / dl of polyethylene terephthalate pellets were obtained. The pellets thus obtained were subjected to solid phase polymerization at 230 ° C. for 20 hours under a reduced pressure of 133 Pa or less, whereby [η] = 0.85 g / dl and ethylene terephthalate cyclic trimer content of 0.25 parts by weight. A polyethylene terephthalate chip was obtained.

Reference example 2
Production of polyethylene naphthalate (PEN) 100 parts by weight of dimethyl naphthalate and 50 parts by weight of ethylene glycol are heated and melted at 190 ° C. in a vessel equipped with a rectifying column and a stirrer. After melting, 0.05 part by weight of magnesium acetate tetrahydrate was added with stirring, the temperature was gradually raised to 240 ° C., and methanol was distilled off to obtain a low molecular weight product. After adding 0.02 part by weight of trimethyl phosphate, 0.04 part by weight of antimony trioxide and 0.5 part by weight of colloidal silica (Nissan Chemical Co., Ltd.) having an average particle diameter of 20 nm, 290 ° C. The temperature inside the reaction vessel was gradually reduced while the temperature was raised to 133 Pa or less. Thereafter, a polycondensation reaction is carried out while distilling off ethylene glycol and water, and after reaching a predetermined stirring torque, it is discharged in a gut shape, cooled in a water tank, and then cut into gut shapes, and [η] = 0. 61 polyethylene naphthalate pellets were obtained. The pellets thus obtained were subjected to solid state polymerization at 230 ° C. for 20 hours under reduced pressure of 133 Pa or less, whereby [η] = 0.80 g / dl, ethylene naphthalate cyclic trimer content 0.30 parts by weight A polyethylene terephthalate chip was obtained.

Reference example 3
Ethylene-methacrylic acid copolymer Na salt (PEMA-Na)
Radical polymerization was performed at 60 ° C. under a nitrogen atmosphere using 83 parts by weight of ethylene distilled under reduced pressure and 17 parts by weight of methyl methacrylate as an initiator and 0.1 part by weight of 2,2-azobisisobutyronitrile. Washing was performed several times to obtain an ethylene-methyl methacrylate copolymer. Further, this was hydrolyzed under an acid catalyst to obtain an ethylene-methacrylic acid copolymer (methacrylic acid component content: 15 parts by weight). 100 parts by weight of the copolymer dried at 60 ° C. for 8 hours and 5.6 parts by weight of sodium carbonate were mixed with a biaxial three-stage screw (PET and PPS kneading plasticizing zone / Supplied to a vent type twin screw extruder (L / D = 40, vent vacuum degree 200 Pa) equipped with a dalmage kneading zone / a fine dispersion compatibilization zone by reverse screw dalmage), and melt extruded in a residence time of 3 minutes, Ethylene-methacrylic acid copolymer Na salt (PEMA-Na) was obtained.

Reference example 4
Ethylene-acrylic acid copolymer K salt (PEMA-K)
An ethylene-methacrylic acid copolymer K salt (PEMA-K) was obtained in the same manner as in Reference Example 3 except that 7.2 parts by weight of potassium carbonate was used instead of 5.6 parts by weight of sodium carbonate.

Reference Example 5
Ethylene-acrylic acid copolymer Li salt (PEMA-Li)
An ethylene-methacrylic acid copolymer Li salt (PEMA-Li) was obtained in the same manner as in Reference Example 3, except that 3.9 parts by weight of lithium carbonate was used instead of 5.6 parts by weight of sodium carbonate.

Reference Example 6
Styrene-4-vinylbenzoic acid copolymer Na salt (PSVBA-Na)
Radicals at 60 ° C. under a nitrogen atmosphere using 80 parts by weight of styrene sufficiently distilled under reduced pressure, 20 parts by weight of 4-vinylbenzoic acid and 0.1 part by weight of 2,2-azobisisobutyronitrile as an initiator. Polymerization was performed and washing was performed several times to obtain a styrene-4-vinylbenzoic acid copolymer. 100 parts by weight of the copolymer dried at 60 ° C. for 8 hours and 3.2 parts by weight of sodium carbonate are supplied to a twin screw extruder equipped with a vent, melt-kneaded at 150 ° C., and styrene-4-vinylbenzoic acid. A copolymer Na salt (PSVBA-Na) was obtained.

Example 1
90 parts by weight of PET obtained in Reference Example 1 was dried at 150 ° C. under reduced pressure of 133 Pa or less for 4 hours, while 10 parts by weight of (PEMA-Na) obtained in Reference Example 3 was reduced at 60 ° C. under reduced pressure of 133 Pa or less. Dry for 8 hours. Vent type equipped with a biaxial, three-stage screw heated to 280 to 300 ° C. (composition of PET and PPS kneading plasticization zone / dull mage kneading zone / inverted screw dull mage). Supplyed to a twin-screw extruder (L / D = 40, vent vacuum 200 Pa), melt-extruded in a residence time of 3 minutes, master pellet containing 10 wt% ethylene-acrylic acid copolymer and 102 mol / ton Na (M-1) was obtained.
1 part by weight of the master pellet M-1 and 99 parts by weight of the PET pellets obtained in Reference Example 1 (that is, 0.1 parts by weight of PEMA-Na with respect to PET) are mixed, and 3 hours at 180 ° C. After drying, it is supplied to a melt extruder equipped with a T-die heated to 260 to 280 ° C., discharged into a sheet, and solidified by an electrostatic application method on a casting drum cooled to 25 ° C. and cooled. And an unstretched film was obtained.

  Subsequently, the obtained unstretched film was stretched 3.5 times at a temperature of 95 ° C. using a circumferential speed difference of the rolls using a longitudinally stretched air consisting of a plurality of heated roll groups, The film is gripped at both ends with a clip, stretched 4.0 times in the width direction at a temperature of 100 ° C. in a tenter, further heat-treated at 220 ° C. for 5 seconds, and further relaxed by 4% in the width direction. After the cooling, a biaxially stretched film having a thickness of 25 μm was obtained. Table 1 shows the evaluation results of various physical properties. The Na content contained in the film was 1 mol / ton, and the heat resistance, heat-and-moisture resistance, and the amount of oligomer were all acceptable.

Examples 2-5
Biaxial orientation as in Example 1 except that the amount of M-1 is changed to 5, 10, 20, and 50 parts by weight so that the PEMA-Na and Na contents are the values shown in Table 1. A film was obtained. All films had acceptable levels of heat resistance, heat and humidity resistance, and oligomers.

Examples 6 and 7
A film was obtained in the same manner as in Example 1 except that PEMA-K and PEMA-Li were used instead of PEMA-Na. The metal content was the same as in Example 3 as the molar amount, but the film was slightly inferior in heat and moisture resistance.

Examples 8-10
A film was obtained in the same manner as in Example 1 except that PSVBA-Na was used instead of PEMA-Na. Compared to PEMA, the film was excellent in heat resistance.

Reference Example 7
In a reaction vessel under a nitrogen atmosphere, 18 parts by weight of ethylene, 75 parts by weight of norbornene, and 17 parts by weight of methyl methacrylate are dissolved in toluene, and while stirring, ethylene is replaced with nitrogen and sealed. Methylaluminoxane was added as a co-catalyst here, and after stirring for 30 minutes, rac-dimethylsilylbis (2-methyl-e-benzenyl) zirconium dichloride was added as a catalyst, and an ethylene-norbornene-methyl methacrylate random copolymer was added. Got. This was hydrolyzed under an acid catalyst to obtain an ethylene-norbornene-methacrylic acid random copolymer (PENMA) (ethylene component 8 parts by weight, norbornene component 77 parts by weight, methacrylic acid component 15 parts by weight). 100 parts by weight of PENMA dried at 60 ° C. for 8 hours and 5.6 parts by weight of sodium carbonate were kneaded with a twin screw extruder equipped with a vent, and an ethylene-norbornene-methacrylic acid random copolymer Na salt (PENMA-Na) was added. Obtained.

Examples 11-13
A film was obtained in the same manner as in Example 1 except that PEMA-Na was used in place of PEMA-Na and that the PENMA and Na contents were as shown in the table.
In terms of heat resistance, the best film was obtained.

Reference Example 8
A PET having [η] = 0.70 and an ethylene terephthalate cyclic trimer content of 0.50 wt% was obtained in the same manner as in Reference Example 1, except that the solid phase polymerization time was 10 hours.
Example 14
A film was obtained in the same manner as in Example 1 except that PET of Reference Example 8 was used instead of PET of Reference Example 1. Although both heat resistance and moist heat resistance were acceptable levels, the film was slightly inferior.

Example 15
A film was obtained in the same manner as in Example except that PEN of Reference Example 2 was used instead of PET of Reference Example 1. It was a film with excellent heat and moisture resistance.

Comparative Example 1
A film was obtained by carrying out film formation in the same manner as in Example 1 except that only PET was used without using M-1. The heat resistance, moist heat resistance, and oligomer content were all unacceptable levels.

Comparative Example 2
A film was obtained by carrying out film formation in the same manner as in Example 1 except that the amount of M-1 was 60 parts by weight and the contents of PEMA-Na and Na were added so as to have the values shown in the table. . Both heat resistance and moist heat resistance were unacceptable levels.

Reference Example 9
PET was obtained in the same manner as in Reference Example 1 except that [η] reached by melt polymerization was 0.6 dl / g and the solid phase polymerization time was not performed. The cyclic trimer content was 1.1 parts by weight.

Comparative Example 3
A film was obtained in the same manner as in Example 1 except that PET of Reference Example 9 was used instead of PET of Reference Example 1. The heat resistance, heat-and-moisture resistance, and oligomer content were all unacceptable.

Reference Example 10
Ethylene-acrylic acid copolymer Zn salt (PEMA-Zn)
An ethylene-methacrylic acid copolymer Zn salt (PEMA-Zn) was obtained in the same manner as in Reference Example 3 except that 13 parts by weight of zinc carbonate was used instead of 5.6 parts by weight of sodium carbonate.

Comparative Example 4
A film was obtained in the same manner as in Example 1 except that PEMA-Zn was used instead of PEMA-Na. The film was inferior in heat resistance and moist heat resistance.

Comparative Example 5
75 parts by weight of PET obtained in Reference Example 1, 25 parts by weight of polybutylene terephthalate resin (Toraycon “Toraycon” 1100S intrinsic viscosity 0.89 dl / g), 30 parts by weight of PEMA-Na (ie, 77 parts by weight of the polyester composition) 23 parts by weight of PEMA-Na) was premixed and charged into an extruder to obtain a PET / PBT / PEMA-Na film having this composition ratio. It was clearly inferior in heat resistance and moist heat resistance.

The film of the present invention has excellent dimensional stability, heat resistance, heat and humidity resistance, and excellent processability, so that it is suitable for printed circuit boards, electrical insulation, capacitors, packaging, ink ribbons, process papers, etc. It is suitable as a film for various industrial materials, and particularly suitable for electrical insulation applications such as a compressor.

Claims (11)

Based on polyester,
0.1 to 5 parts by weight of a polyolefin-containing composition having a carboxylic acid group in the side chain, based on 100 parts by weight of the whole polymer composition,
Containing 1 to 50 mol / ton of at least one metal element selected from Li, Na and K with respect to the weight of the polymer composition;
The polymer composition for molded articles, wherein the content of the ester cyclic trimer is 0.1 to 0.6 parts by weight based on 100 parts by weight of the whole polymer composition. Part or all of the side chain carboxylic acid in the polyolefin-containing composition having a carboxylic acid group in the side chain, and part or all of at least one metal element selected from Li, Na, and K form a salt. The polymer composition according to claim 1, wherein: The polymer composition according to claim 1 or 2, wherein the polyolefin-containing composition having a carboxylic acid group in the side chain is a copolymer of ethylene and an unsaturated carboxylic acid. The polymer composition according to claim 1 or 2, wherein the polyolefin-containing composition having a carboxylic acid group in the side chain is a copolymer of styrene and aromatic vinyl. The polymer composition according to claim 1 or 2, wherein the polyolefin-containing composition having a carboxylic acid group in the side chain contains a saturated and / or unsaturated cycloalkylene structure. The polymer composition according to any one of claims 1 to 5, wherein the polyester composition is polyethylene terephthalate. The polymer composition according to any one of claims 1 to 5, wherein the polyester composition is polyethylene-2,6-naphthalate. A biaxially stretched film comprising the polymer composition according to any one of claims 1 to 7. The biaxially stretched film according to claim 8, wherein the half life of elongation at break in a moisture and heat resistance test is 20 hours or more. The biaxially stretched film according to claim 8 or 9, wherein a half-life of elongation at break in a heat resistance test is 15 hours or more. It is an electrical insulation use, The biaxially stretched film as described in any one of Claims 8-10 characterized by the above-mentioned.