JP6490976B2 - Two-layer preform and blow molded body - Google Patents

Description

  The present invention relates to a preform and a blow molded article comprising two layers of copolymerized polyethylene terephthalate and polyethylene naphthalate.

  Conventionally, metal containers have been mainly used for pressure vessels. However, since they are heavy, they are difficult to carry, and there is a problem that energy costs for transportation are high, and resin containers are being studied. However, the resin pressure vessel has an advantage that the weight of the vessel can be reduced. However, since the gas barrier property is inferior to that of metal, it is necessary to increase the thickness of the vessel.

  Polyethylene terephthalate is inexpensive and easy to obtain and has excellent gas barrier properties, so it is widely used in PET bottles, etc., but the preform crystallizes during preform molding, making it impossible to blow mold, increasing the thickness of the preform I can't. On the other hand, Patent Document 1 discloses a multi-layer container of isophthalic acid copolymerized polyethylene terephthalate and polyethylene terephthalate having excellent gas barrier properties and low crystallinity. Although the gas barrier property of isophthalic acid copolymerized polyethylene terephthalate increases as the copolymerization ratio increases, it is difficult to increase the degree of polymerization together with the copolymerization ratio. There is also a limit to the thickness of the preform that can be increased.

  Polyethylene naphthalate, on the other hand, has a gas barrier property that exceeds that of polyethylene terephthalate, and the crystallization rate is slow, so that the thickness of the preform can be increased. However, there is a problem that it is very expensive compared to polyethylene terephthalate. For this reason, many multilayer molded articles of polyethylene naphthalate and polyethylene terephthalate have been disclosed. For example, Patent Document 2 exemplifies a multilayer preform of polyethylene terephthalate and polyethylene naphthalate. However, since the thickness of the container body is as thin as 0.1 to 0.5 mm, a container to which high pressure such as a pressure container is applied. Then, the gas barrier property was insufficient.

JP 59-067049 A Japanese Patent Laid-Open No. 4-039025

  An object of the present invention is to provide a preform and a blow-molded body that can be blow-molded even with a wall thickness, have excellent gas barrier properties, have a barrel thickness as designed, and are economical. .

  As a result of intensive research aimed at achieving the above-mentioned object, the present inventors have determined that the thickness of the isophthalic acid-copolymerized polyethylene terephthalate layer and the thickness of the polyethylene naphthalate layer are within the specified ranges, so The present inventors have found that a preform and a blow molded article that can be molded and have excellent gas barrier properties can be provided, and have solved the above problems.

  That is, the above problem is that (A) dicarboxylic acid component (A-1 component) is terephthalic acid or its ester derivative (A-1-1 component) 80 to 95 mol% and isophthalic acid or its ester derivative (A-1). -Component 2) consisting of 5 to 20 mol%, the diol component (component A-2) consisting of ethylene glycol, the layer of copolymerized polyethylene terephthalate (layer A) and (B) the dicarboxylic acid component (component B-1) Is at least one selected from the group consisting of naphthalenedicarboxylic acid or its ester derivative (B-1-1 component) 80-100 mol% and terephthalic acid, isophthalic acid and these ester derivatives (B-1-2 component) Polyethylene naphthalene consisting of 0 to 20 mol% and having a diol component (component B-2) consisting of ethylene glycol A preform having a two-layer structure composed of a layer (B layer), wherein the thickness of the A layer of the preform body is 5 mm or more, the thickness of the B layer is 10 mm or more, and the total thickness is 15 mm. The above-described two-layered preform is achieved.

  Because it is a preform that can be blow-molded even when it is thick, it has excellent gas barrier properties and can be used as a liner for various pressure vessels such as LPG cylinders, carbon dioxide cylinders, oxygen cylinders, natural gas cylinders, etc. It is useful above.

It is sectional drawing of the preform which concerns on this invention. It is sectional drawing of the blow molded object which concerns on this invention.

Hereinafter, the preparation method and molding method of each resin layer used in the present invention will be described in order.
<A layer>
In the present invention, the copolymerized polyethylene terephthalate used in the A layer has a dicarboxylic acid component (component A-1) of 80 to 95 mol% of terephthalic acid or an ester derivative thereof (component A-1-1) and isophthalic acid or a component thereof. It is a copolymerized polyethylene terephthalate comprising 5 to 20 mol% of an ester derivative (component A-1-2) and a diol component (component A-2) comprising ethylene glycol.

  The copolymerization ratio of the A-1-1 component and the A-1-2 component is preferably 80-88 mol% for the A-1-1 component, 12-20 mol% for the A-1-2 component, more preferably The A-1-1 component is 85 to 88 mol%, and the A-1-2 component is 12 to 15 mol%. If the ratio of the A-1-2 component is less than 5 mol%, the crystallinity is too high, so that it is crystallized when a thick preform is molded, and cannot be expanded during blow molding and is damaged. . When the ratio of the A-1-2 component exceeds 20 mol%, the crystallinity is lowered, and the thickness of the body portion is reduced at the time of blow molding, which is not preferable. In addition, the thickness of the shoulder portion and the bottom portion is conversely increased by reducing the thickness of the trunk portion. The copolymerized polyethylene terephthalate of the present invention can contain other dicarboxylic acid components and diol components in a range of 10 mol% or less within the range not departing from the spirit of the present invention.

  The intrinsic viscosity (IV) of the copolymerized polyethylene terephthalate is preferably 0.5 to 1.0 dl / g, more preferably 0.55 to 0.90 dl / g, and still more preferably 0.6 to 0.85 dl. / G. If the intrinsic viscosity is greater than 1.0 dl / g, the appearance of the gate portion (bottom of the container) may be whitened due to an increase in resin pressure applied during injection molding. When the intrinsic viscosity is less than 0.5 dl / g, the crystallinity of the copolymerized polyethylene terephthalate increases, and it may crystallize when a thick preform is molded and may be damaged during blow molding. The intrinsic viscosity is 0.6 g of the resin heated and melted in 50 ml of a phenol / tetrachloroethane = 3/2 (weight ratio) mixed solvent, cooled to room temperature, and the viscosity of the obtained resin solution is the Ostwald viscosity. It measured on the temperature conditions of 35 degreeC using the pipe | tube, and calculated | required from the data of the obtained solution viscosity.

  The copolymerized polyethylene terephthalate of the present invention can be produced by either a transesterification method or a direct esterification method. In addition, when manufacturing by a transesterification method, a transesterification reaction catalyst is required. The transesterification catalyst is not particularly limited, and manganese compounds, calcium compounds, magnesium compounds, titanium compounds, zinc compounds, sodium compounds, potassium compounds, cerium compounds, lithium compounds, etc. that are generally widely used as transesterification catalysts for polyethylene terephthalate are used. Can be mentioned. Further, a cobalt compound may be contained as a transesterification reaction catalyst that also acts as a color adjusting agent.

  When the copolymerized polyethylene terephthalate of the present invention is produced by a direct esterification method, it is not necessary to deactivate the catalyst because a transesterification reaction catalyst is not used as in the case of the above transesterification method. It is preferable to add such that the remaining amount of the compound is 5 to 100 mmol% with respect to the total acid component. If the residual amount of the phosphorus compound is in the above range, it is preferable in terms of heat resistance and hue.

  As the polycondensation catalyst, a titanium compound, an antimony compound and a germanium compound are preferably used. Examples of the antimony compound include antimony oxide, antimony acetate, and antimonic acid glycolate, among which antimony trioxide is preferably used. When the antimony compound is contained, the content of the antimony compound is preferably 5 to 40 mmol% based on the total acid component in terms of antimony trioxide. When the content of the antimony compound is less than 5 mmol%, the polymerization activity is low, the polycondensation time becomes long, and it is not preferable from an economic viewpoint such as a decrease in production cycle, but also an increase in side reaction products and a deterioration in hue. Since it is inferior also in quality, it is not preferable. When the content of the antimony compound exceeds 40 mmol%, it is not preferable from the viewpoint that the amount of side reaction products due to acceleration of the color plane and decomposition reaction such as blackening due to precipitation of the antimony compound increases.

  As the germanium compound, germanium dioxide is preferably used. When a germanium compound is contained, the content of the germanium compound is preferably 15 to 50 mmol% with respect to the total acid component. If it is less than 15 mmol%, the polymerization activity is low, the polycondensation time is long and not preferable in terms of economy such as a decrease in production cycle, but also inferior in terms of quality such as increase of side reaction products and deterioration of hue, etc. Absent. When the content of the germanium compound exceeds 50 mmol%, it is not preferable in that the side reaction product increases due to the promotion of the decomposition reaction.

  Tetraalkyl titanate is preferably used as the titanium compound. When a titanium compound is contained, n-butyl phosphate is required as a stabilizer. It is necessary that the molar ratio (P / Ti) of phosphorus atoms to titanium atoms contained is 1 to 3. When P / Ti is less than 1, the phosphorus atom concentration is relatively reduced, so that the hue of the resulting polymer becomes inadequate and yellowish, and its heat resistance may be lowered. . On the other hand, if the value of P / Ti exceeds 3, the phosphorus atom concentration is relatively increased, which is not preferable in terms of economy such as a decrease in polymerizability, that is, a polycondensation reaction rate. Moreover, it is preferable that it is 2-40 mmol% as content of a titanium compound with respect to all the acid components. When the content of the titanium compound is less than 2 mmol%, the polymerization activity is low, the polycondensation time becomes long, and this is not preferable in terms of economy such as a reduction in production cycle. When the content of the titanium compound exceeds 40 mmol%, the resulting polymer has an insufficient hue and becomes yellowish, which may reduce its practicality.

  In order to adjust the copolymerized polyethylene terephthalate to a desired intrinsic viscosity, solid phase polymerization can be further applied. The reaction temperature in the solid phase polymerization is preferably 230 ° C. or lower. When the solid-state polymerization reaction temperature is carried out exceeding 230 ° C., the degree of crystallinity of the resulting polymer is increased, the appearance of the molded product is impaired, and it acts as a nucleating agent, resulting in whitening of the molded product. .

<B layer>
In the present invention, the polyethylene naphthalate used in the B layer has a dicarboxylic acid component (B-1 component) of naphthalenedicarboxylic acid or an ester derivative thereof (B-1-1 component) of 80 to 100 mol%, terephthalic acid, isophthalic acid. Polyethylene naphthalate, which is composed of 0 to 20 mol% selected from the group consisting of acids and ester derivatives thereof (B-1-2 component), and the diol component (B-2 component) is ethylene glycol.

  The copolymerization ratio of the B-1-1 component and the B-1-2 component is preferably 85 to 100 mol% for the B-1-1 component, 0 to 15 mol% for the B-1-2 component, more preferably The B-1-1 component is 90 to 98 mol%, and the B-1-2 component is 2 to 10 mol%. If the B-1-2 component exceeds 20 mol%, the crystallinity is lowered, the thickness of the body is reduced during blow molding, and the gas barrier property is rapidly deteriorated, so that the gas barrier property as a container cannot be maintained. In addition, the polyethylene naphthalate of this invention can contain another dicarboxylic acid component and a diol component in the range of 10 mol% or less in the range which is not contrary to the meaning of this invention.

  The intrinsic viscosity (IV) of polyethylene naphthalate is preferably 0.5 to 1.0 dl / g, more preferably 0.55 to 0.90 dl / g, still more preferably 0.6 to 0.85 dl / g. g. If the intrinsic viscosity is greater than 1.0 dl / g, the appearance of the gate portion (bottom of the container) may be whitened due to an increase in resin pressure applied during injection molding. When the intrinsic viscosity is less than 0.5 dl / g, the crystallinity of polyethylene naphthalate increases, and it may crystallize when a thick preform is molded and may be damaged during blow molding. The intrinsic viscosity was measured by the same method as for copolymerized polyethylene terephthalate.

  Polyethylene naphthalate can be produced by a conventionally known production method. That is, the dicarboxylic acid and diol are directly reacted to distill off water and esterify, and then the direct esterification method in which polycondensation is performed under reduced pressure, or the dicarboxylic acid dimethyl ester and diol are reacted to distill off methyl alcohol and esterify. After the exchange, it is produced by a transesterification method in which polycondensation is performed under reduced pressure. Further, solid state polymerization can be performed to increase the intrinsic viscosity number.

In the transesterification reaction, esterification reaction and polycondensation reaction, it is preferable to use a catalyst and a stabilizer. As the transesterification catalyst, magnesium compounds, manganese compounds, calcium compounds, zinc compounds and the like are used, and examples thereof include acetates, monocarboxylates, alcoholates, and oxides thereof. Further, the esterification reaction can be carried out only with dicarboxylic acid and diol without adding a catalyst, but can also be carried out in the presence of a polycondensation catalyst. As the polycondensation catalyst, germanium compounds, titanium compounds, antimony compounds, and the like can be used. Examples thereof include germanium dioxide, germanium hydroxide, germanium alcoholate, titanium tetrabutoxide, titanium tetraisopropoxide, and titanium oxalate. . As the stabilizer, a phosphorus compound is preferably used. Preferable phosphorus compounds include phosphoric acid and its ester, phosphorous acid and its ester, hypophosphorous acid and its ester, and the like. In addition, in the esterification reaction, a tertiary amine such as triethylamine, a quaternary ammonium hydroxide such as tetraethylammonium hydroxide, and a basic compound such as sodium carbonate can be added to suppress diethylene glycol by-product.
The copolymerized polyethylene terephthalate and polyethylene naphthalate of the present invention can contain additives such as a heating aid, an antioxidant, and a mold release agent as long as they do not contradict the spirit of the present invention.

<Heating aid>
The polyethylene terephthalate and polyethylene naphthalate of the present invention can contain a heating aid for the purpose of improving the heating efficiency by an infrared (IR) heater during blow molding and shortening the heating time. Such heating aids include phthalocyanine-based near-infrared absorbers, metal oxide-based near-infrared absorbers such as ATO, ITO, iridium oxide, ruthenium oxide and imonium oxide, metals such as lanthanum boride, cerium boride and tungsten boride. Preferable examples include various metal compounds having excellent near-infrared absorption ability, such as boride-based and tungsten oxide-based near-infrared absorbers, and carbon fillers. As such a phthalocyanine-based near infrared absorber, for example, MIR-362 manufactured by Mitsui Chemicals, Inc. is commercially available and easily available. Examples of the carbon filler include carbon black, graphite (including both natural and artificial) and fullerene, and carbon black and graphite are preferable. These can be used alone or in combination of two or more. The content of the phthalocyanine-based near-infrared absorber is preferably 0.0005 to 0.2 parts by weight, and 0.0008 to 0.1 parts by weight with respect to 100 parts by weight of the resin component in each of polyethylene terephthalate and polyethylene naphthalate. More preferred is 0.001 to 0.07 part by weight. If the content is less than 0.0005 parts by weight, the effect as a heating aid may not be sufficiently obtained, and it may take a long time to heat the preform during blow molding. Moreover, when this content is more than 0.2 parts by weight, the heating aid may bleed out during blow molding overheating. The content of the metal oxide near infrared absorber, metal boride near infrared absorber, tungsten oxide infrared absorber and carbon filler is preferably in the range of 0.1 to 500 ppm (weight ratio) in the resin composition. The range of 0.5 to 300 ppm is more preferable. If the content is less than 0.1 ppm, the effect as a heating aid may not be sufficiently obtained, and it may take a long time to heat the preform during blow molding. In addition, when the content is more than 500 ppm, the resin component may be greatly decomposed.

<Antioxidant>
The polyethylene terephthalate and polyethylene naphthalate of the present invention contain at least one antioxidant selected from the group consisting of hindered phenol compounds, phosphite compounds, phosphonite compounds, and thioether compounds as an antioxidant. Can do. By blending an antioxidant, not only is the hue and fluidity at the time of molding stabilized, it is also effective in improving hydrolysis resistance.

  Examples of the hindered phenol compound include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-tert-butylfel) propionate. 2-tert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,6-di-tert-butyl-4- (N, N-dimethylaminomethyl) phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-methylenebi (2,6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-cyclohexylphenol), 2,2′-dimethylene-bis (6-α-methyl-benzyl-p-cresol) ) 2,2′-ethylidene-bis (4,6-di-tert-butylphenol), 2,2′-butylidene-bis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3- Methyl-6-tert-butylphenol), triethylene glycol-N-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,6-hexanediol bis [3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl 6- ( -Tert-butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1 , 1, -dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 4,4′-thiobis (6-tert-butyl-m-cresol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4 , 4′-di-thiobis (2,6-di-tert-butylphenol), 4,4′-tri-thiobis (2,6-di-tert-butylphenol) ), 2,2-thiodiethylenebis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy -3 ′, 5′-di-tert-butylanilino) -1,3,5-triazine, N, N′-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N, N′-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butyl Phenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl) 4-hydroxyphenyl) isocyanurate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6- Dimethylbenzyl) isocyanurate, 1,3,5-tris 2 [3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanurate, and tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane and the like. Among the above compounds, tetrakis [methylene-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] methane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate and 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10 -Tetraoxaspiro [5,5] undecane is preferably used. Particularly preferred is octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate. All of these are readily available. The said hindered phenol type compound can be used individually or in combination of 2 or more types.

  Phosphite compounds include triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl mono Phenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, tris (diethylphenyl) phosphite, tris (di-iso-propylphenyl) phosphite, tris (di-n-butylphenyl) ) Phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, distearyl pentae Thritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis ( 2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite, phenylbisphenol A penta Examples include erythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, and dicyclohexylpentaerythritol diphosphite. Furthermore, as other phosphite compounds, those that react with dihydric phenols and have a cyclic structure can be used. For example, 2,2′-methylenebis (4,6-di-tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite, 2,2′-methylenebis (4,6-di-tert- Butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, and the like. Suitable phosphite compounds are distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methyl). Phenyl) pentaerythritol diphosphite, and bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite.

  Also, for example, 2,4,8,10-tetra-t-butyl-6- [3- (3-methyl-4-hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3 , 2] dioxaphosphine [commercially available as “Sumilyzer GP” (manufactured by Sumitomo Chemical Co., Ltd.). 2,10-dimethyl-4,8-di-t-butyl-6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] dibenzo [D, f] [1,3,2] dioxaphosphine, 2,4,8,10-tetra-t-pentyl-6- [3- (3,5-di-t-butyl-4- Hydroxyphenyl) propoxy] -12-methyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,10-dimethyl-4,8-di-t-butyl-6- [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -12H Dibenzo [d, g] [1,3,2] dioxaphosphocine, 2,4,8,10-tetra-t-pentyl-6- [3- (3,5-di-t-butyl-4- Hydroxyphenyl) propionyloxy] -12-methyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -dibenzo [d, f] [1,3,2] dioxaphosphine, 2,10-dimethyl-4,8-di -T-butyl-6- (3,5-di-t-butyl-4-hydroxybenzoyloxy) -12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,4,8 , 10-Tetra-t-butyl-6- (3,5-di-t-butyl-4- Roxybenzoyloxy) -12-methyl-12H-dibenzo [d, g] [1,3,2] dioxaphosphocin, 2,10-dimethyl-4,8-di-t-butyl-6- [3- (3-Methyl-4-hydroxy-5-t-butylphenyl) propoxy] -12H-dibenzo [d, g] [1,3,2] dioxaphosphocine, 2,4,8,10-tetra-t -Butyl-6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -12H-dibenzo [d, g] [1,3,2] dioxaphosphocine, 2,10 -Diethyl-4,8-di-t-butyl-6- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propoxy] -12H-dibenzo [d, g] [1,3 2] Dioxaphosphocin, 2,4,8,10-tetra-t-butyl Ru-6- [2,2-dimethyl-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -dibenzo [d, f] [1,3,2] dioxaphosphine And so on. All of these are readily available. The above phosphite compounds can be used alone or in combination of two or more.

  Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylene diphospho Knight, tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3′-biphenylene diphosphonite, Bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,4- -Tert-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) Examples include -4-phenyl-phenyl phosphonite, bis (2,6-di-tert-butylphenyl) -3-phenyl-phenyl phosphonite. Tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite, bis (di-tert-butylphenyl) -phenyl-phenylphosphonite are preferred, and tetrakis (2,4-di-tert-butylphenyl) -biphenylenediphosphonite Knight and bis (2,4-di-tert-butylphenyl) -phenyl-phenylphosphonite are more preferred. Such a phosphonite compound is preferable because it can be used in combination with a phosphite compound having an aryl group in which two or more alkyl groups are substituted. The phosphonite compound is preferably tetrakis (2,4-di-tert-butylphenyl) -biphenylenediphosphonite, and stabilizers based on the phosphonite are Sandostab P-EPQ (trademark, manufactured by Clariant) and Irgafos. P-EPQ (trademark, manufactured by CIBA SPECIALTY CHEMICALS) is commercially available and any of them can be used. The said phosphonite type compound can be used individually or in combination of 2 or more types.

  Specific examples of thioether compounds include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol-tetrakis (3-lauryl thiopropionate), Pentaerythritol-tetrakis (3-dodecylthiopropionate), pentaerythritol-tetrakis (3-octadecylthiopropionate), pentaerythritol tetrakis (3-myristylthiopropionate), pentaerythritol-tetrakis (3-stearylthio) Propionate) and the like. The said thioether type compound can be used individually or in combination of 2 or more types.

  The content of the antioxidant is preferably 0.01 to 2 parts by weight, more preferably 0.03 to 1 part by weight, and still more preferably 0 to 100 parts by weight of the resin component in each of polyethylene terephthalate and polyethylene naphthalate. 0.05 to 0.5 parts by weight. When the content of the antioxidant is less than 0.01 parts by weight, the antioxidant effect is insufficient, and not only the hue and fluidity at the time of molding become unstable, but also the hydrolysis resistance may deteriorate. . In addition, when the content is more than 2 parts by weight, the reaction component derived from the antioxidant may be deteriorated and the hydrolysis resistance may be deteriorated.

  In addition, it is preferable to use a combination of two or more of the hindered phenol compounds and phosphite compounds, phosphonite compounds, and thioether compounds. By using a combination of two or more of hindered phenol compounds and phosphite compounds, phosphonite compounds, and thioether compounds, a synergistic effect as a stabilizer is demonstrated, and more hue and flow during molding. It is effective in stabilizing the properties and improving the hydrolysis resistance.

<Release agent>
The polyethylene terephthalate and polyethylene naphthalate of the present invention can contain a release agent. Specific examples of release agents include fatty acids, fatty acid metal salts, oxy fatty acids, paraffins, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid partial saponified esters, fatty acid lower alcohol esters, fatty acid polyvalents. Examples thereof include alcohol esters, fatty acid polyglycol esters, and modified silicones. By blending these, a molded product excellent in mechanical properties, moldability, and heat resistance can be obtained.

Fatty acids having 6 to 40 carbon atoms are preferred. Specifically, oleic acid, stearic acid, lauric acid, hydroxystearic acid, behenic acid, arachidonic acid, linoleic acid, linolenic acid, ricinoleic acid, palmitic acid, montan Examples thereof include acids and mixtures thereof. The fatty acid metal salt is preferably an alkali (earth) metal salt of a fatty acid having 6 to 40 carbon atoms, and specific examples include calcium stearate, sodium montanate, and calcium montanate.
Examples of the oxy fatty acid include 1,2-oxysteric acid. Paraffin having 18 or more carbon atoms is preferable, and examples thereof include liquid paraffin, natural paraffin, microcrystalline wax, petrolactam and the like.
As the low molecular weight polyolefin, for example, those having a molecular weight of 5000 or less are preferable, and specific examples include polyethylene wax, maleic acid-modified polyethylene wax, oxidized type polyethylene wax, chlorinated polyethylene wax, and polypropylene wax.

Fatty acid amides having 6 or more carbon atoms are preferred, and specific examples include oleic acid amide, erucic acid amide, behenic acid amide and the like.
The alkylene bis fatty acid amide is preferably one having 6 or more carbon atoms, and specifically includes methylene bis stearic acid amide, ethylene bis stearic acid amide, N, N-bis (2-hydroxyethyl) stearic acid amide and the like.
As the aliphatic ketone, those having 6 or more carbon atoms are preferable, and examples thereof include higher aliphatic ketones.
Examples of the fatty acid partial saponified ester include a montanic acid partial saponified ester. Examples of the fatty acid lower alcohol ester include stearic acid ester, oleic acid ester, linoleic acid ester, linolenic acid ester, adipic acid ester, behenic acid ester, arachidonic acid ester, montanic acid ester, isostearic acid ester and the like.

Examples of fatty acid polyhydric alcohol esters include glycerol tristearate, glycerol distearate, glycerol monostearate, pentaerythritol tetrastearate, pentaerythritol tristearate, pentaerythritol dimyristate, pentaerythritol Examples include tall monostearate, pentaerythritol adipate stearate, sorbitan monobehenate and the like. Examples of fatty acid polyglycol esters include polyethylene glycol fatty acid esters, polytrimethylene glycol fatty acid esters, and polypropylene glycol fatty acid esters.
Examples of the modified silicone include polyether-modified silicone, higher fatty acid alkoxy-modified silicone, higher fatty acid-containing silicone, higher fatty acid ester-modified silicone, methacryl-modified silicone, and fluorine-modified silicone.

Of these, fatty acid, fatty acid metal salt, oxy fatty acid, fatty acid ester, fatty acid partial saponified ester, paraffin, low molecular weight polyolefin, fatty acid amide, and alkylene bis fatty acid amide are preferable, and fatty acid partial saponified ester and alkylene bis fatty acid amide are more preferable. Of these, montanic acid ester, montanic acid partial saponified ester, polyethylene wax, acid value polyethylene wax, sorbitan fatty acid ester, erucic acid amide, and ethylene bisstearic acid amide are preferable, and montanic acid partial saponified ester and ethylene bisstearic acid amide are particularly preferable. .
A mold release agent may be used by 1 type and may be used in combination of 2 or more type. The content of the release agent is preferably 0.01 to 3 parts by weight, and more preferably 0.03 to 2 parts by weight with respect to 100 parts by weight of the resin component in each of polyethylene terephthalate and polyethylene naphthalate.

<Preform>
The thickness of the preform body of the present invention is such that the thickness of the copolymerized polyethylene terephthalate layer (A layer) is 5 mm or more, the thickness of the polyethylene naphthalate layer (B layer) is 10 mm or more, and the total thickness is 15 mm or more. It is. The thickness of the A layer is preferably 8 mm or more, and more preferably 10 mm or more. Moreover, although an upper limit is not prescribed | regulated in particular, 20 mm or less is preferable. The thickness of the B layer is preferably 15 mm or more, more preferably 20 mm or more. Moreover, although an upper limit is not prescribed | regulated in particular, 30 mm or less is preferable. Furthermore, the total thickness is preferably 20 mm or more, more preferably 25 mm or more. Moreover, although an upper limit is not prescribed | regulated in particular, 50 mm or less is preferable. If the thickness of the A layer is less than 5 mm, the amount of copolymer polyethylene terephthalate used is too small, and the total cost of the preform increases. When the thickness of the B layer is less than 10 mm, the gas barrier property as a container is not sufficient. Further, if the total thickness is less than 15 mm, the gas barrier property as a container is not sufficient.
The A layer and the B layer can be used for both the inner layer and the outer layer, but from the viewpoint of cost, it is preferable to use the B layer for the inner layer because the thickness can be increased with a small amount of resin.

  The copolymerized polyethylene terephthalate and polyethylene naphthalate of the present invention are usually obtained as pellets, and a preform is formed from this as a raw material. Various molding methods such as injection molding, press molding, and extrusion molding can be selected as the molding method, but injection molding and press molding are preferred from the viewpoint of rapid cooling without crystallizing the preform. In the injection molding, not only a normal cold runner molding method but also a hot runner molding method is possible. In such injection molding, not only a normal molding method but also injection compression molding, injection press molding, foam molding (including by supercritical fluid injection), insert molding, in-mold coating molding, as appropriate, depending on the purpose. A molded product can be obtained using an injection molding method such as rapid heating / cooling die molding. In the production of a preform, a preform composed of a copolymerized polyethylene terephthalate layer (A layer) and a polyethylene naphthalate layer (B layer) can be produced in a single stage by co-injection molding. (A layer) or a polyethylene naphthalate layer (B layer) can be produced by injection molding followed by two-stage sequential molding in which the other layer is injection molded. In the case of producing a preform, for example, in the case of injection molding, each pellet is preferably pre-dried for 5 hours or more with a hot air dryer at 130 to 170 ° C., and then melted at a cylinder temperature of 260 to 300 ° C. and injection molded. . If the predrying temperature is less than 130 ° C, the drying becomes insufficient, the resin may be decomposed by moisture remaining in the pellets, and the intrinsic viscosity may not be stable. If the predrying temperature is higher than 170 ° C, the pellets turn yellow. The appearance of the molded body may be impaired. The mold temperature for molding the preform is preferably 5 to 40 ° C, more preferably 10 to 30 ° C. When the mold temperature is less than 5 ° C, the appearance of silver or the like may frequently occur in the molded product due to the condensation of the mold. When the mold temperature exceeds 40 ° C, the crystallization of the preform proceeds and blow molding is performed. Container may be damaged.

<Blow molding>
Arbitrary methods are employ | adopted for the preparation methods of the container of this invention. Examples thereof include direct blow molding, extrusion direct blow molding, one-stage biaxial stretch blow molding, and two-stage biaxial stretch blow molding. Two-stage biaxial stretch blow molding is preferable.
The container of the present invention preferably has a draw ratio of 10 to 20 times in terms of the thickness of the trunk, and more preferably a draw ratio of 12 to 18 times. When the draw ratio is less than 10 times, stretch unevenness occurs in the container, so that the gas barrier property may be lowered. When the draw ratio exceeds 20 times, a fine crack may be partially generated, which is not preferable.

  When biaxial stretching blow is performed in two stages, it is preferable to preheat (preheat) before blow molding. The preheating temperature is preferably 70 to 140 ° C, preferably 90 ° C to 130 ° C, and most preferably 100 ° C to 110 ° C. If the preheating temperature is less than 70 ° C., it takes time for the main heating time in the subsequent process. If the preheating temperature exceeds 140 ° C., the copolymerized polyethylene terephthalate crystallizes, and the container may be damaged during blow molding. is there. The preheating method may be any method such as storage of a preform in a hot air dryer or heating with an infrared heater.

  Heating during blow molding (main heating) is preferably performed from both heating from inside the preform (internal heating) and heating from outside the preform (external heating) because the preform is thick. As the heating method, an infrared heating method is preferable since heating efficiency is good. Here, the glass transition temperature of the A layer is 70 to 80 ° C., whereas the glass transition temperature of the B layer is 100 to 120 ° C., and the B layer is higher by 30 to 50 ° C. It is necessary to heat the resin to a temperature corresponding to the glass transition temperature on the B layer side. Specifically, in the main heating, the resin temperature on the A layer side needs to be warmed to about 90 to 110 ° C., and the resin temperature on the B layer side needs to be warmed to about 130 to 160 ° C. By performing blow molding in such a resin temperature range, it is possible to obtain a good blow molded article with little thickness unevenness and without tearing. Therefore, the output control of the internal heater and the external heater needs to be set according to the resin temperature of the A layer and the B layer.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to these.
1. Production method of copolymerized polyethylene terephthalate and polyethylene naphthalate Copolymerized polyethylene terephthalate and polyethylene naphthalate were produced by the method shown in the following production examples. Moreover, the value of the intrinsic viscosity in the production examples was determined by the following method.

(1) Intrinsic Viscosity (IV) Measurement Method 0.6 g of resin was melted by heating in 50 ml of a mixed solvent of phenol / tetrachloroethane = 3/2 (weight ratio), then cooled to room temperature, and the viscosity of the resulting resin solution Was measured using an Ostwald viscosity tube at a temperature of 35 ° C., and the intrinsic viscosity (IV) of the resin was determined from the obtained solution viscosity data.

(2) Production of resin [Production Examples 1 to 7: Copolymerized polyethylene terephthalate PET-1 to 7]
A mixed slurry composed of high-purity terephthalic acid, isophthalic acid and ethylene glycol, prepared in quantities so as to have the polymer composition shown in Table 1, is fed to the esterification reactor at a constant rate and increased to 0.3 MPa at 270 ° C. with stirring. The esterification reaction was carried out while applying nitrogen pressure and distilling off the generated water and ethylene glycol out of the system. The mixed slurry of the same weight was supplied to half of the obtained oligomer, and the esterification reaction was carried out while distilling off the generated water and ethylene glycol under normal pressure at 270 ° C. while stirring. The same operation was repeated 5 times to produce a polyester oligomer with stable quality.

  Next, this polyester oligomer was transferred to a polycondensation reaction vessel, and while stirring, a germanium dioxide catalyst as a polycondensation catalyst was added so as to be 25 mmol% with respect to the total dicarboxylic acid component. Then, orthophosphoric acid was added as a stabilizer so that the phosphorus atom was 12.2 mmol% with respect to the total dicarboxylic acid component. Subsequently, the reaction temperature in the system is increased from 270 ° C. to 285 ° C. and the reaction pressure is gradually increased and reduced from normal pressure to 60 Pa, respectively, and the polycondensation reaction is performed while removing water and ethylene glycol generated in the reaction from the system. Went. The degree of progress of the polycondensation reaction was confirmed as a load on the stirring blade, and the reaction was terminated when the desired degree of polymerization was reached. Thereafter, the reaction product in the system was continuously extruded in a strand form from the discharge part, cooled and cut to obtain about 3 mm granular pellets. The obtained composition and physical properties are shown in Table 1.

[Production Examples 8 to 10, 12, and 13: Polyethylene naphthalate PEN-2 to 4, 6, and 7]
2,6-naphthalenedicarboxylic acid dimethyl ester, terephthalic acid dimethyl ester, ethylene glycol, and 30 mmol% based on the total moles of dicarboxylic acid ester as a transesterification catalyst, the quantities of which were adjusted to the polymer composition shown in Table 2. 70 mmol% manganese acetate tetrahydrate with respect to the total number of moles of cobalt acetate tetrahydrate and dicarboxylic acid ester was supplied to the reactor, and transesterification was performed at 240 ° C. in a nitrogen atmosphere. Subsequently, after adding antimony trioxide at 80 mmol% with respect to the total number of dicarboxylic acid esters, orthophosphoric acid was added with 60 mmol% with respect to the total number of dicarboxylic acid esters and kept at 260 ° C. for 30 minutes. did. Thereafter, the temperature was increased and the pressure was gradually reduced, and polymerization was finally performed at 300 ° C. and 0.1 kPa or less. The degree of progress of the polycondensation reaction was confirmed as a load on the stirring blade, and the reaction was terminated when the desired degree of polymerization was reached. Thereafter, the reaction product in the system was continuously extruded in a strand form from the discharge part, cooled and cut to obtain about 3 mm granular pellets. The obtained composition and physical properties are shown in Table 2.

[Production Example 11: PEN-5]
The same procedure as in Production Example 8 was performed except that dimethyl terephthalate was changed to dimethyl isophthalate. The results are shown in Table 2.

<Other resins>
As other resins, the following resins were used.
PEN-1: Teonex TR-8065S manufactured by Teijin Limited [polyethylene naphthalate produced from 100 mol% naphthalene dicarboxylic acid and 100 mol% ethylene glycol, intrinsic viscosity 0.67 dl / g]

2. Evaluation of Resin Gas Barrier Properties The resin pellets produced in Production Examples 1 to 13 and PEN-1 resin pellets were pre-dried at 160 ° C. for 5 hours in a hot air dryer. Subsequently, the pre-dried pellets were put into a hopper of a single-screw extruder SZW40-28FPLG (Technobel φ40 mm) equipped with a T die having a width of 30 mm, and extruded at an extrusion temperature of 290 ° C. and a screw rotation speed of 60 rpm. The resin coming out of was rolled up while controlling the number of rotations of the roll so that the sheet thickness was 300 μm. The central part of the obtained sheet having a thickness of 300 μm was cut out to 70 mm × 70 mm. Next, the cut sheet is sandwiched between chucks of a biaxial stretching test apparatus X40HDHT (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the stretching ratio is set to 3.6 × longitudinal × 3.6 ×, and the stretching speed is 500 mm. Biaxial stretching at the same time / min. The temperature in the apparatus was 100 ° C. for copolymerized polyethylene terephthalate and 150 ° C. for polyethylene naphthalate.

The oxygen permeability coefficient of the obtained stretched film was measured according to JIS K7126-1 using a differential pressure type gas / vapor permeability measuring device GTR-30XAD2, G2700T · F (manufactured by GTR Tech Co., Ltd.). The measurement was performed under the conditions of a test temperature of 23 ° C., a test differential pressure of 1 atm, a permeation area of 15.2 × 10 ⁻⁴ m ² , and a detector gas chromatograph (heat conduction detector [TCD]). The results are shown in Table 3 and Table 4. In addition, the thickness of a film is the average value of the numerical value which measured 10 points | pieces in the part which measured the oxygen permeability coefficient at random.

3. Evaluation of Preform and Blow Molded Body Preforms and blow molded bodies prepared by the methods shown in the following Examples and Comparative Examples were evaluated by the following methods.

(1) Crystallinity of the preform After the body portion of the preform is cut into pieces using a thread saw, the center portions in the thickness direction of the inner layer and the outer layer (locations 1-1 and 1-2 in FIG. 1) are female. Was used to sample. Subsequently, differential scanning calorimetry (DSC) was performed, and the degree of crystallinity was determined from the following formula using the values of crystallization enthalpy (ΔHc) and melting enthalpy (ΔHm) when the temperature was raised at 20 ° C./min. .

(2) Whitening of preform Visual determination was performed according to the following criteria.
No whitening: When a fluorescent lamp is viewed through a preform, the fluorescent lamp can be visually confirmed.
With whitening: When a fluorescent lamp is seen through a preform, the fluorescent lamp cannot be visually confirmed.

(3) Preform body thickness After the preform body was cut into pieces using a yarn saw, the thickness of the inner layer and the outer layer was measured at equal intervals along the circumferential direction using a 10-point caliper, and the average value was obtained. Was calculated.

(4) Allowability of blow molding Whether the biaxial stretch blow molding is possible was determined according to the following criteria.
Possible: The preform was formed into a container shape without breakage or tearing.
Impossible (damaged): The preform was damaged during the drawing of the rod, and blow molding was not possible.

(5) Body thickness of the blow molded body The center part of the body of the blow molded body is cut into pieces using a yarn saw, and the thicknesses of the inner layer and the outer layer are measured at equal intervals along the circumferential direction using a 10-point caliper. The average value was calculated.

(6) Measured value / theoretical value of blow molded body barrel thickness 13 times, which is the draw ratio design of the 8L container, is the theoretical draw ratio, and the measured values of the inner and outer layer thicknesses of the preform and the inner and outer layer thicknesses of the blow molded article Was used to determine the actual value / theoretical value from the following equation (2). When the actual measurement value / theoretical value was close to 100%, it was determined that the thickness of the body was as designed.

（Ｔ_Ｂ１：ブロー成形体の内層厚み、Ｔ_Ｂ２：ブロー成形体の外層厚み、Ｔ_Ｐ１：プリフォームの内層厚み、Ｔ_Ｐ２：プリフォームの外層厚み）

(T _B1 : inner layer thickness of blow molded body, T _B2 : outer layer thickness of blow molded body, T _P1 : inner layer thickness of preform, T _P2 : outer layer thickness of preform)

(7) Oxygen permeability coefficient calculated from trunk thickness ratio From the measurement results of the oxygen permeability coefficient of each resin shown in Tables 3 and 4, and the trunk thickness measurement value measured in (5), the following equation (3) The oxygen permeability coefficient as a container was calculated.

（Ｐ１：内層の酸素透過係数、Ｐ２：外層の酸素透過係数、Ｔ１：内層の厚み比率、Ｔ２：外層の厚み比率）

(P1: oxygen permeability coefficient of inner layer, P2: oxygen permeability coefficient of outer layer, T1: thickness ratio of inner layer, T2: thickness ratio of outer layer)

(8) Oxygen permeability From the oxygen permeability coefficient calculated in (7) and the total thickness (inner layer thickness + outer layer thickness) of the trunk thickness measured in (5), the oxygen permeability as a container is calculated from the following formula (4). Calculated.

Example 1
After PEN-1 shown in Table 4 was dried with a hot air dryer at 160 ° C. for 5 hours, an inner layer preform was formed. The molding machine used was ULTRA-220-C560-NIV · A manufactured by Sumitomo Heavy Industries, Ltd., and molding was performed at a cylinder temperature of 300 ° C., a mold temperature of 30 ° C., and a cooling time of 180 seconds. After replacing the insert of the preform mold for outer layer molding, the inner layer preform made of PEN-1 was inserted into the mold, and the outer layer was molded using PET-1 which was dried with hot air at 160 ° C. for 5 hours. . The molding machine uses ULTRA-220-C560-NIV · A manufactured by Sumitomo Heavy Industries, Ltd., and molding is performed at a cylinder temperature of 280 ° C., a mold temperature of 30 ° C., and a cooling time of 180 seconds. A layer preform was obtained. Each evaluation mentioned above was performed using the obtained preform.

  Next, FGB-40LC manufactured by Frontier Co., Ltd. equipped with an internal IR heater and an external IR heater was used as a blower, and an 8 L container-shaped blow mold (length 3.1 times x width 13 times 13) Biaxial stretch blow molding of a two-layer preform was performed using a double-stretch design. A two-layer preform preliminarily heated in a hot air dryer at 100 ° C. for 1 hour is set in a blow molding machine, the temperature on the inner layer side made of PEN-1 is 150 ° C., and the temperature on the outer layer side made of PET-1 is 100 The output of the IR heater was set so that the temperature was 0 ° C., and the main heating was performed. Subsequently, rod stretching time 1.3 seconds, primary blow delay time 0.5 seconds, primary blow time 2 seconds, primary blow pressure 1.2 MPa, secondary blow time 9 seconds, secondary blow pressure 3.4 MPa Then, blow molding was performed under the condition of a mold temperature of 20 ° C. to obtain a blow molded article shown in FIG. Each evaluation mentioned above was performed using the obtained blow molded object. The results are shown in Table 5.

(Examples 2 to 20, Comparative Examples 1 to 9)
Except having changed the resin kind and preform thickness which were used for the inner layer and the outer layer into the content of Table 5-Table 8, it shape | molded by the method similar to Example 1, and performed each evaluation. The results are shown in Tables 5-8.

<Examples 1 to 20>
Examples 1 to 20 within the scope of the claims were capable of being molded even with thick preforms, had a barrel portion with a thickness as designed, and were excellent in oxygen gas barrier properties. In particular, when PET 3 to 4 having a high isophthalic acid copolymerization ratio and IV of 0.5 or more is used, crystallization is suppressed even when the thickness of the preform is increased as in Examples 18 and 19, and Excellent transparency.

<Comparative Examples 1 and 6>
When PET-6 having an isophthalic acid copolymerization ratio of 4 mol% was used, crystallization of the preform was confirmed, and the preform was damaged during rod drawing of blow molding, and blow molding could not be performed.

<Comparative Examples 2 and 7>
When PET-7 having an isophthalic acid copolymerization ratio of 22 mol% was used, the thickness of the body of the copolymer polyethylene terephthalate layer (A layer) of the blow molded product was extremely thin, and the thickness did not become as designed. .

<Comparative Example 3>
When PET-7 with an isophthalic acid copolymerization ratio of 22 mol% and PEN-7 with a terephthalic acid copolymerization ratio of 22 mol% are used, a copolymerized polyethylene terephthalate layer (layer A) and a polyethylene naphthalate layer (layer B) In both cases, the thickness of the torso became extremely thin, the thickness did not become as designed, and the oxygen permeability deteriorated.

<Comparative Examples 4 and 5>
When PEN-7 having a terephthalic acid copolymerization ratio of 22 mol% was used, the thickness of the polyethylene naphthalate layer (B layer) was extremely thin, and the thickness did not become as designed. Moreover, since the B layer thickness which is excellent in gas barrier property became thin, oxygen permeability also deteriorated.

<Comparative Example 8>
Since the total thickness was thin, the oxygen permeability deteriorated.

<Comparative Example 9>
Since the polyethylene naphthalate layer (B layer) was thin, the oxygen permeability was deteriorated.

1-A: preform outer layer 1-B: preform inner layer 1-C: preform body portion 1-D: preform mouth portion 1-1: crystallinity measurement point of preform outer layer 1-2: preform inner layer 2-A: Blow-molded body mouth 2-B: Blow-molded body neck 2-C: Blow-molded body shoulder 2-D: Blow-molded body body 2-E: Blow Bottom of molded body

Claims (5)

(A) When dicarboxylic acid component (A-1 component) is 100 mol% of dicarboxylic acid component, terephthalic acid or its ester derivative (A-1-1 component) 80-95 mol% and isophthalic acid or its ester A layer (A layer) made of copolymerized polyethylene terephthalate (A) and a dicarboxylic acid component (B) consisting of 5 to 20 mol% of a derivative (A-1-2 component) and a diol component (A-2 component) consisting of ethylene glycol. B-1 component), when the dicarboxylic acid component is 100 mol%, naphthalenedicarboxylic acid or its ester derivative (B-1-1 component) 80-100 mol% and terephthalic acid, isophthalic acid and their ester derivatives The diol component (B) comprises at least one selected from the group consisting of 0 to 20 mol% (B-1-2 component). The two-component preform is a two-layered structure composed of a layer (B layer) made of polyethylene naphthalate made of ethylene glycol, and the thickness of the A layer of the preform body is 5 mm or more, and the B layer A two-layered preform having a thickness of 10 mm or more and a total thickness of 15 mm or more.   The preform according to claim 1, wherein the intrinsic viscosity of the copolymerized polyethylene terephthalate is 0.5 to 1.0 dl / g, and the intrinsic viscosity of the polyethylene naphthalate is 0.5 to 1.0 dl / g. When the dicarboxylic acid component (A-1 component) is 100 mol% of the dicarboxylic acid component, 80 to 88 mol% of terephthalic acid and its ester derivative (A-1-1 component) and isophthalic acid and its ester derivative (A The preform according to claim 1 or 2, comprising 12 to 20 mol% of (-1-2 component).   A blow-molded product obtained by biaxially stretch-blowing the preform according to any one of claims 1 to 3.   The blow molded article according to claim 4, wherein the draw ratio is 10 to 20 times.

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