JP2018100129A - Laminate bottle and manufacturing method of laminate bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated bottle in which a polyester resin and a polyolefin resin can be melt-extruded and molded at the same time, and the polyester resin is used as an outer layer and the polyolefin resin is used as an inner layer. SOLUTION: This is a laminated bottle in which a polyester resin (A) is used for an outer layer and a polyolefin resin (B) is used for an inner layer. The polyester resin (A) has an acid component containing terephthalic acid as a main component. The glycol component is mainly composed of ethylene glycol and 1,4-butanediol, and the mass ratio of ethylene glycol and 1,4-butanediol is 80/20 to 30/70, and the crystal melting point is 160 to 220 ° C. The ultimate viscosity is 0.5 to 1.0, and at least one of the polyester resin (A) and the polyolefin resin (B) contains 0.05 to 3.0% by mass of inorganic particles and / or pigment. Laminated bottle. [Selection diagram] None

Description

  The present invention relates to a laminated bottle in which a polyester resin that can be molded at a low temperature is arranged in an outer layer and a polyolefin resin is arranged in an inner layer, and has a superior surface appearance.

  Polyethylene terephthalate (PET) is excellent in mechanical properties, chemical stability, transparency and the like, is inexpensive, and is widely used as various sheets, films, containers and the like. The growth in the use of hollow containers (bottles) for fruit juice drinks, liquid seasonings, edible oils, liquors, wines, etc. is remarkable. Moreover, since there is little concern about residual monomers and harmful additives in hollow molded articles made of vinyl chloride resin, and hygiene and safety are high, replacement from conventional bottles made of vinyl chloride resin and the like is also progressing.

  In general, when plastic bottles are manufactured, melt-plasticized resin is used as die orifices in terms of ease of molding, high productivity, and relatively low equipment costs such as molding machines and molds. A so-called direct blow molding method is employed in which a cylindrical parison is formed through extrusion, and air is blown into the mold by sandwiching the parison between the molds. In the case of this direct blow molding, it is necessary to avoid that the parison extruded in the molten state is drawn down during the blow molding in order to perform the molding smoothly. Therefore, a high melt viscosity is required for the resin used. Is done. Accordingly, vinyl chloride resins, polyolefin resins, and the like are widely used in direct blow molding as resins having a high melt viscosity.

  Polyolefin resins have excellent moldability and are inexpensive and are widely used in bottle containers. Patent Document 1 discloses a multilayer blow molding formed from a polyester resin and a polyolefin resin. Multilayer structures such as containers and multilayer sheets have been proposed.

  In the multilayer structure described in Patent Document 1, it is indicated that the polyester resin specifically shown in the examples is an amorphous polyester resin. However, it is not disclosed at all what kind of resin composition the polyester resin is used for. The amorphous polyester resin described in Patent Document 1 is assumed to be a polyester resin containing a large amount of a copolymer component in order to enable plasticizing extrusion at a temperature equivalent to that of a polyolefin resin. Such an amorphous polyester resin tends to cause chip-to-chip fusion, and it is necessary to perform the drying process at a low temperature before performing the use. It is inferior.

  Further, Patent Document 2 has a multilayer structure in which a first resin layer made of a first polyester and a second resin layer made of at least one resin selected from the group consisting of a second polyester, polyamide, and polyolefin are laminated. Proposed polyester laminates. It is described that the laminate described in Patent Document 2 has a high crystallization rate and is excellent in gas barrier properties, transparency, and heat resistance.

  However, in Patent Document 2, what is specifically shown in the examples is only one using the second polyester as the second resin layer, that is, the first polyester and the second polyester are laminated. Only the multilayer structure is illustrated, and no laminate in which the first polyester and the polyolefin are laminated is shown.

  In general, the melting point of a general-purpose polyester resin is about 50 ° C. higher than the melting point of a polyolefin resin, so it is difficult to obtain a molded body such as a sheet or a container by simultaneously extruding both resins. There has not yet been proposed a laminate (a bottle having a polyester resin layer and a polyolefin resin layer) having good moldability, excellent appearance, and sufficient strength.

  In recent years, plastic bottles made of polyester resin or polyolefin resin have been used for cosmetics and other applications where high decorativeness is required, and surface appearance such as those with excellent surface gloss and color tone. The demand for excellent bottles is also high.

Japanese Patent Laid-Open No. 5-193059 Japanese Patent Application Laid-Open No. 10-211684

  The present invention solves the above-mentioned problems, and can be formed by simultaneously melt-extruding a polyester resin and a polyolefin resin at the same temperature and using the polyester resin for the outer layer and the polyolefin resin for the inner layer. It is a technical problem to provide a laminated bottle having an excellent surface appearance.

The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the gist of the present invention is the following (A) to (C).
(A) A laminated bottle comprising a polyester resin (A) as an outer layer and a polyolefin resin (B) as an inner layer, wherein the polyester resin (A) has terephthalic acid as a main component, glycol The component is composed mainly of ethylene glycol and 1,4-butanediol, and the mass ratio of ethylene glycol and 1,4-butanediol is 80/20 to 30/70, and the crystalline melting point is 160 to 220 ° C. A laminate having a viscosity of 0.5 to 1.0, and at least one of the polyester resin (A) and the polyolefin resin (B) contains 0.05 to 3.0% by mass of inorganic particles and / or pigments. Bottle.
(B) The laminated bottle according to (a), which has an adhesive layer (C) between the polyester resin (A) layer and the polyolefin resin (B) layer.
(C) The laminated bottle according to (a) or (b), wherein the polyester resin (A) is an outer layer and the polyolefin resin (B) is an inner layer, and both resins are melt extruded and blow molded simultaneously. Production method.

The laminated bottle of the present invention uses a polyester resin (A) as an outer layer and a polyolefin resin (B) as an inner layer. The polyester resin (A) has a specific composition and has a relatively low crystalline melting point. Therefore, it can be obtained by molding at the same molding temperature as the polyolefin resin. Moreover, since the polyester resin (A) in the present invention is crystalline, it is difficult for chips to adhere to each other during storage of raw materials, the drying treatment can be performed at a high temperature in a short time, and the operability is excellent. Is.
Furthermore, the laminated bottle of the present invention contains a specific amount of inorganic particles or pigment in the polyester resin (A) or polyolefin resin (B). Depending on the type of inorganic particles or pigment used, the surface glossiness or color tone is increased. It can be made excellent. Furthermore, the laminated bottle of this invention is excellent also in decorating property (especially printability) by using the polyester resin (A) of a specific composition for an outer layer.
As described above, the laminated bottle of the present invention can be obtained with good moldability, excellent surface appearance, and excellent decorating properties, and thus can be used for various applications.

Hereinafter, the present invention will be described in detail.
In the polyester resin (A) in the present invention, the acid component is mainly composed of terephthalic acid (hereinafter sometimes abbreviated as TPA), and terephthalic acid is 90 mol% or more of the acid component. It is preferable that it is 95 mol% or more. As is known as the acid component of polyethylene terephthalate, terephthalic acid contributes to providing preferable physical properties common to polyesters in general. When the proportion of terephthalic acid is less than 90 mol%, the crystallinity tends to be inferior.

  On the other hand, the glycol component in the polyester resin (A) is mainly composed of ethylene glycol (hereinafter sometimes abbreviated as EG) and 1,4-butanediol (hereinafter sometimes abbreviated as BD). Among them, the ratio of both components is preferably 90 mol% or more, and more preferably 95 mol% or more.

  And mass ratio (EG / BD) of both is 80 / 20-30 / 70, and it is preferable that it is 70 / 30-40 / 60 especially. Outside this range, the melting point of the polyester resin increases. Further, the crystallinity of the polyester resin is deteriorated, tetrahydrofuran is generated during the polycondensation reaction, and the thermal stability of the polyester resin is deteriorated. For this reason, it becomes difficult to perform molding at a low temperature in accordance with the molding temperature of the polyolefin resin.

  Moreover, as a component which comprises a polyester resin (A), in addition to the above-mentioned terephthalic acid, ethylene glycol, and 1, 4- butanediol, in the range which does not impair the objective of this invention, other components are copolymerized. May be. Such other components include isophthalic acid, 5-sodium sulfoisophthalic acid, diethylene glycol, propylene glycol, pentaerythritol, neopentyl glycol, 4-hydroxybenzoic acid, adipic acid, sebacic acid, naphthalenedicarboxylic acid, bisphenol A, Bisphenol S etc. are mentioned.

  The terephthalic acid, ethylene glycol, 1,4-butanediol and other components as components constituting the above-described polyester resin (A) include these ester-forming derivatives as a concept. Such an ester-forming derivative may be used in combination as a copolymerization component.

  And the polyester resin (A) of this invention has a crystalline melting point, and the crystalline melting point is 160-220 degreeC, and it is preferable that it is 180-200 degreeC especially. When the crystal melting point is less than 160 ° C., the heat resistance of the laminated bottle of the present invention is insufficient. On the other hand, if it exceeds 220 ° C., the heat treatment temperature at the time of molding must be increased, which is disadvantageous in terms of cost and cannot be adjusted to the molding temperature of the polyolefin resin. Furthermore, it is necessary to increase the kneading temperature when the inorganic particles are contained, and the dispersibility of the inorganic particles is poor.

Further, the polyester resin (A) preferably satisfies the following intrinsic viscosity and carboxyl end group concentration as characteristic values suitable for blow molding.
The intrinsic viscosity (IV) of the polyester resin (A) is preferably 0.5 to 1.0, and more preferably 0.6 to 0.9. The intrinsic viscosity (IV) is measured at a temperature of 20 ° C. using a mixture of equal mass of phenol and ethane tetrachloride as a solvent.

  When the intrinsic viscosity is less than 0.5, since the viscosity of the resin is low, the drawdown of the parison becomes large at the time of blow molding, and the obtained molded product tends to have thickness unevenness. On the other hand, when the intrinsic viscosity exceeds 1.0, it is necessary to increase the temperature during molding, which is disadvantageous in terms of cost, and tends to be inferior in dispersibility of inorganic particles. It becomes inferior in operability, for example, it is necessary to increase the kneading temperature or to knead for a long time.

  Furthermore, the polyester resin (A) preferably has a carboxyl end group concentration of 30 equivalent / t or less, preferably 28 equivalent / t or less, and more preferably 26 equivalent / t or less. By setting the carboxyl end group concentration of the polyester resin (A) to 30 equivalent / t or less, it is possible to prevent thermal decomposition of the resin during blow molding, so that a decrease in viscosity can be suppressed and stable molding can be achieved. It becomes possible. When the carboxyl end group concentration exceeds 30 equivalents / t, even if the intrinsic viscosity of the resin is in the above range, the resin is thermally decomposed by heat treatment during blow molding, Viscosity decreases. For this reason, the drawdown of the parison becomes large, making molding difficult, and even if it is obtained, the molded product has uneven thickness.

In the present invention, at least one of the polyester resin (A) and the polyolefin resin (B) contains inorganic particles and / or pigments. And these content needs to contain 0.05-3.0 mass% in a lamination bottle. That is, only the polyester resin (A), only the polyolefin resin (B), and both resins may contain inorganic particles and / or pigments. In either case, the content of inorganic particles and pigments in the laminated bottle is 0. It is necessary to set it as 0.05-3.0 mass%, and it is preferable to make content of an inorganic particle and a pigment into 0.2-2.8 mass% especially.
When the content of the inorganic particles and the pigment in the laminated bottle is less than 0.1% by mass, a desired color tone or the like is not exhibited. On the other hand, if it exceeds 3.0% by mass, aggregation of inorganic particles and pigment occurs, the operability deteriorates, and the resulting laminated bottle has a poor surface appearance, inferior quality, transparency, It becomes inferior in glossiness.

  Transparent particles can be used as the inorganic particles used in the present invention. Examples of the transparent particles include silica, glass particles (glass beads), talc, alumina, titanium oxide, kaolin, zeolite, aluminosilicate, calcium nitrate, barium nitrate, and calcium carbonate.

  As the pigment used in the present invention, it is preferable to use a metallic pigment as a pigment exhibiting excellent metallic tone in all of brightness, glossiness and profound feeling. As the metallic pigment, for example, any one of a group of metals consisting of aluminum, iron, nickel, chromium, tin, zinc, indium, titanium, silicon, and copper, or a plurality thereof, or an alloy using these groups of metals, Alternatively, a metal powder pigment made of any of oxides, nitrides, sulfides, and carbides of the group of metals or alloys thereof may be used. In addition, titanium-coated mica can also be used.

  Furthermore, organic pigments such as azo pigments, phthalocyanine pigments, condensed polycyclic pigments, and dyed lake pigments can also be used as organic pigments.

Further, the polyester resin (A) may contain an antioxidant. Among them, the hindered phenol-based antioxidant is preferably added so as to be 0.01 to 2.0% by mass in the polyester resin, and more preferably 0.1 to 1.0% by mass. .
By adding an appropriate amount of a hindered phenol-based antioxidant, it has an effect of suppressing thermal decomposition of the phthalic acid component, and the color tone of the polyester resin is improved. Further, the antioxidant is decomposed to produce pentaerythritol (tetrafunctional component), which is incorporated into the molecular chain of the polyester, thereby increasing the viscosity of the polyester resin.

  If the hindered phenol-based antioxidant is less than 0.01% by mass, it is difficult to achieve the above effects. On the other hand, if it exceeds 2.0% by mass, the possibility of gelation in the polycondensation reaction is increased and the polyester resin is likely to be colored, which is not preferable.

  Examples of the hindered phenol antioxidant include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenylpropionate], 1,6-hexanediol-bis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxylphenyl) propionate] and the like.

  Further, in the polyester resin (A) in the present invention, in addition to the above-described antioxidants, examples of coloring inhibitors include phosphorous acid, phosphoric acid, trimethyl phosphite, triphenyl phosphite, and tridecyl phosphite. Phosphorus compounds such as phyto, trimethyl phosphate, tridecyl phosphate and triphenyl phosphate can be used. These phosphorus compounds may be used alone or in combination of two or more. In addition, additives such as cobalt compounds such as cobalt acetate, manganese compounds such as manganese acetate, anthraquinone dye compounds, and copper phthalocyanine compounds may be contained in order to suppress coloring due to thermal decomposition of the polyester resin.

Next, the manufacturing method of a polyester resin (A) is demonstrated. The polyester resin in the present invention is preferably obtained through an esterification reaction and a melt polymerization reaction step.
Further, a solid phase polymerization reaction step may be performed after the melt polymerization reaction step. By making these steps and conditions specific, the polyester resin of the present invention can be obtained.

Specifically, for example, it can be produced by the following method.
First, in an esterification reaction vessel in which bis- (β-hydroxyethyl) terephthalate or its low polymer exists under nitrogen gas suppression at a temperature of 230 to 250 ° C., ethylene glycol and terephthalic acid are used. The slurry having a molar ratio of 1.1 to 2.0 is continuously added, and an ester oligomer having an average polymerization degree of 10 or less is continuously obtained with a residence time of 7 to 8 hours. Next, this ester oligomer consisting of terephthalic acid and ethylene glycol is transferred to a melt polycondensation reaction can, and 1,4-butanediol is added at a mass ratio of ethylene glycol / 1,4-butanediol of 80/20 to 30/70. The reaction is carried out at 200 to 230 ° C. In addition, when the temperature of reaction is less than 200 degreeC, reaction will only become slow, and there exists a possibility that ester oligomer may solidify. On the other hand, when it exceeds 230 ° C., 1,4-butanediol decomposes during the reaction to form tetrahydrofuran, and a polyester resin having a predetermined ratio of 1,4-butanediol cannot be obtained.

  Further, after adding a polycondensation catalyst, the temperature of the melt polycondensation reaction vessel is raised to 200 to 250 ° C., and the melt polycondensation reaction is performed under a reduced pressure of 0.01 to 13.3 hPa until a predetermined intrinsic viscosity is reached. I do. In this way, the polyester resin of the present invention produced by performing a melt polycondensation reaction under predetermined conditions is discharged into a number of rods by being extruded from a nozzle using gas pressure, cut into chips. Obtained as a form.

  In order to set the carboxyl end group concentration of the polyester resin (A) to 30 equivalent / t or less, as described above, the mass ratio of ethylene glycol / butanediol to the ester oligomer composed of terephthalic acid and ethylene glycol is 80 This is achieved by adding it in an amount in the range of / 20 to 30/70 and carrying out the copolymerization reaction at a predetermined temperature.

As the polycondensation catalyst, one or more known compounds generally used for PET, for example, germanium, antimony, titanium, and cobalt compounds can be used, but germanium or antimony compounds are preferably used. Further, when the transparency of the resulting polyester resin is very important, it is preferable to use a germanium compound. Examples of germanium or antimony compounds include oxides, inorganic acid salts, organic acid salts, halides, and sulfides thereof. These polycondensation catalysts are used in the range of 5 × 10 ⁻⁵ mol to 8.0 × 10 ⁻⁴ mol, especially 6 × 10 ⁻⁵ mol to 5.0 × 10 ⁵ mol per 1 mol of the acid component of the polyester resin to be produced. It is preferably used in such an amount that it is within the range of ^-4 mol.

  In the case of undergoing a solid-phase polymerization reaction step after the melt polymerization reaction step, the polyester resin is dried and crystallized in advance, and then usually from the melting point of the polyester under reduced pressure or under an inert gas flow such as nitrogen. Is preferably carried out by reacting the polyester in the reactor at a temperature lower by 20 to 30 ° C. for 3 to 50 hours. By carrying out the solid phase polymerization reaction, the intrinsic viscosity can be further increased or the amount of the oligomers contained can be further decreased.

  The polyester resin (A) or the polyolefin resin (B) contains inorganic particles and pigments by dry blending the resin and inorganic particles and pigments before molding the laminated bottle, and melt-kneading the resin composition. It is preferable to prepare a product. And it is preferable to shape | mold a laminated bottle using this resin composition.

When inorganic particles and pigments are contained in the resin, a master chip containing inorganic particles and pigments at a high concentration (about 5 to 20% by mass) in the resin is prepared in advance, and the master is formed at the time of molding the laminated bottle. It is also preferable to employ a method in which the chip is melt-kneaded with a resin containing no inorganic particles or pigment.
In any method, when the resin and inorganic particles or pigment are melt-kneaded, it is preferable to use a uniaxial or biaxial extruder at a temperature of 200 to 250 ° C.

  Next, the polyolefin resin (B) will be described. Examples of the polyolefin resin include olefin homopolymers such as polyethylene, polypropylene, poly-1-butene, polymethylpentene, and polymethylbutene, and olefin copolymers such as propylene / ethylene random copolymer. Polyethylene and polypropylene are particularly preferred. Such polyolefin may be used independently and may be used in combination of 2 or more type.

  Such a polyolefin resin can be produced by a conventionally known production method. Moreover, you may contain additives, such as a coloring agent, an antioxidant, a ultraviolet absorber, an antistatic agent, a flame retardant, and a lubricant, as needed.

  In the present invention, it is preferable to use polyethylene as the polyolefin resin (B), and it is more preferable to use high density polyethylene. Examples of the high-density polyethylene include Novatec (registered trademark) HD “HB420R”, “HB410R”, “HB321R”, “HB220R”, “HB214R”, “HB214RW”, and “HB120R” manufactured by Nippon Polyethylene.

And the laminated bottle of this invention uses a polyester resin (A) for an outer side layer, and uses a polyolefin resin (B) for an inner side layer. The thickness of the layer of the polyester resin (A) and the layer of the polyolefin resin (B) is not particularly limited, and the layer of the polyester resin (A) is 0.01 to 0.5 mm, the layer of the polyolefin resin (B). Is preferably 0.1 to 1.0 mm.
The ratio of both resins can be appropriately selected according to the application, but the mass ratio of both resins is 0.5 / 9.5-5 / 5 for polyester resin (A) / polyolefin resin (B). Of these, 1/9 to 3/7 is preferable.

  Furthermore, the laminated bottle of this invention is excellent in decorating property by using such a polyester resin (A) for an outer layer. In particular, the ink placement during printing (silk printing) is good, and the printability is excellent. In general, when printing on a bottle using a polyolefin resin as an outer layer, the ink is poorly placed, so it is necessary to perform a treatment that roughens the surface. No need for surface treatment.

When the laminated bottle of the present invention contains inorganic particles or pigment only in the polyester resin (A) of the outer layer, it can be easily adjusted to a color tone considering that the bottle surface is printed by post-processing.
On the other hand, when the laminated bottle of the present invention contains inorganic particles or pigment only in the polyolefin resin (B) of the inner layer, the polyester resin (A) of the outer layer is a transparent layer, so the color of the inner layer is glossy. Can be added to obtain a bottle with excellent color tone.

  Further, since the polyester resin (A) is crystalline, it can be subjected to a drying heat treatment when obtaining the polyester resin, and water management is easy. If it is an amorphous polyester resin, the drying heat treatment cannot be performed at a high temperature when the polyester resin is obtained, and the water content becomes unstable. Since the polyolefin resin does not contain moisture, productivity is deteriorated if it is affected by moisture of the polyester resin when both are melt-extruded at the same time. That is, by using the polyester resin (A) of the present invention, moisture management becomes easy, and it becomes possible to obtain a laminated bottle of excellent quality with good productivity.

Furthermore, the laminated bottle of the present invention preferably has an adhesive layer (C) between the polyester resin (A) layer and the polyolefin resin (B) layer.
As described above, the layer of the polyester resin (A) and the layer of the polyolefin resin (B) are easy to follow because of good followability, and a laminated bottle can be obtained with high productivity. By having the adhesive layer (C), it is further difficult for peeling to occur, and a laminated bottle in which both resin layers are well bonded can be obtained.

  As the adhesive layer (C), it is preferable to use a polyolefin-based adhesive resin or an amorphous polyester resin. Polyolefin-based adhesive resins are preferably those obtained by introducing polar groups into nonpolar polyolefins, such as “Modic” (registered trademark) series manufactured by Mitsubishi Chemical Corporation and “Admer” (registered trademark) series manufactured by Mitsui Chemicals, Inc. Among these, “F502” and “F532” of the “Modic” series are preferable.

  The amorphous polyester resin that can be used as the adhesive layer (C) preferably has a glass transition point in the range of 40 to 80 ° C. When the glass transition point is lower than 40 ° C., the moldability is inferior, and when it exceeds 80 ° C., the self-adhesiveness at low temperature and low pressure is lowered.

  Such an amorphous polyester resin can be produced by, for example, a known method based on a melt polycondensation method such as a direct ester method or a transesterification method, using a divalent alcohol component and a divalent carboxylic acid component. However, the number average molecular weight is preferably 10,000 or more from the viewpoint of mechanical strength and heat resistance of the molded body. In order to obtain an amorphous polyester resin having such a molecular weight, there are a method of stopping the viscosity of the polyester melt at the time of polymerization, a method of adding a monofunctional alcohol or carboxylic acid in advance, and the like.

  Divalent alcohol components include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polytetramethylene glycol, Polyethylene glycol, cyclohexanedimethanol, ethylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol S, 2- (9,10-dihydro-9-oxa-10-oxide-phosphaphenanthrene) methyl bis- (2-hydroxyethyl) -ester and the like. These raw materials are not necessarily used alone, and may be used by copolymerizing two or more. Among these, it is preferable to use ethylene glycol and neopentyl glycol together. Trivalent or higher alcohols such as trimethylolpropane, pentaerythritol, glycerin and the like can also be used.

  Examples of divalent carboxylic acid components include terephthalic acid, isophthalic acid, oxalic acid, malonic acid, succinic acid, adipic acid, itaconic acid, azelaic acid, sebacic acid, icodic acid diacid, naphthalenedicarboxylic acid, diphenic acid, dodecanediic acid Examples thereof include acid and cyclohesandicarboxylic acid. These raw materials are not necessarily used alone, and may be used by copolymerizing two or more kinds. Of these, terephthalic acid, isophthalic acid, and adipic acid are preferably used together. Trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid can also be used. Furthermore, it is also possible to use alkyl ester bodies, such as said dimethyl ester body. Moreover, the raw material which has ring structures, such as (epsilon) -caprolactone and (gamma) -butyrolactone, can also be used.

  Specific examples of such an amorphous polyester resin include Elitel (registered trademark) “UE-3210” and “UE-3200” manufactured by Unitika. “UE-3210” is a copolymer of phthalic acid, isophthalic acid, adipic acid, neopentyl glycol, and ethylene glycol. “UE-3200” is a copolymer of terephthalic acid, isophthalic acid, neopentyl glycol, and ethylene glycol. It is. In addition, there is "PETG" manufactured by Eastman Chemical Company. “PETG” is a copolymer of terephthalic acid, cyclohexanedimethanol and ethylene glycol.

  The adhesive layer (C) may also contain inorganic particles and / or pigments as described above used in the present invention. In this case, the content of the inorganic particles and the pigment is 0.05 to 3.0 mass in the laminated bottle together with the amount contained in at least one of the polyester resin (A) and the polyolefin resin (B). % Content is preferable.

  The proportion of the adhesive layer (C) in the laminated bottle of the present invention may be appropriately selected according to the use, but is preferably 0.1 to 15% by mass in the laminated bottle, and particularly 1 to 10% by mass. It is preferable to do.

  In producing the laminated bottle of the present invention, a conventionally known blow molding method can be employed. As a blow molding method, a melt-plasticized resin is extruded through a die orifice to form a cylindrical parison, and the parison is formed by direct blow molding method in which air is blown inside by sandwiching the resin between the molds or injection molding. Examples of the stretch blow molding method include stretch blow molding, which is suitable for the direct blow molding method.

  At this time, direct blow molding is performed using a general-purpose multilayer direct blow molding machine equipped with two or more melt extruders, or a multilayer parison is fabricated using a stretch blow molding machine equipped with two or more melt extruders. It is possible to obtain a blow-molded body by producing and subjecting this to stretch blow molding. And it is preferable to make the temperature of each part and nozzle of a molding machine into the range of 160-250 degreeC.

Next, the present invention will be specifically described using examples. The measurement and evaluation methods for various characteristic values in the examples are as follows.
(A) Intrinsic viscosity [η] of polyester resin (A)
The measurement was carried out at a temperature of 20 ° C. using a mixture of equal mass of phenol and ethane tetrachloride as a solvent.
(B) Carboxyl end group concentration of polyester resin (A) 0.1 g of the obtained polyester resin was dissolved in 10 ml of benzyl alcohol, 10 ml of chloroform was added to this solution, and then 1/10 N potassium hydroxide benzyl alcohol solution was added. Determined by titration with

(C) Composition of polyester resin (A) The polyester resin (A) is dissolved in a mixed solvent having a dose ratio of deuterated hexafluoroisopropanol and deuterated chloroform of 1/20, and LA-400 manufactured by JEOL Ltd. Type NMR apparatus 1H-NMR was measured, and the copolymerization amount and content were determined from the integrated intensity of the proton peak of each component of the obtained chart.
(D) Melting point (Tm) of polyester resin (A)
A differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer Co.) was used and the temperature was increased at a rate of 20 ° C./min.
(E) Content of inorganic particles and pigment in the polyester resin (A) The polyester resin (A) is melt-molded into a disk-shaped molding plate having a diameter of 3 cm and a thickness of 1 cm, and a fluorescent X-ray analyzer ZSX Primus manufactured by Rigaku Corporation. Was used to measure the content.

(F) Formability Using 100 obtained laminated bottles as samples, measure the thickness of the body of 100 samples, and the difference between the thickness of the thickest part and the thinnest part is up to 0.30 mm. The sample was accepted and the number of samples accepted was shown. The number of acceptable samples is preferably 90 or more.
(G) Surface appearance (glossiness)
The appearance of the obtained laminated bottle was visually observed to determine whether there was glossiness or not, and was evaluated in two stages as follows.
○: glossy ×: no gloss (h) surface appearance (brightness)
The appearance of the obtained laminated bottle was observed from a direction at an angle of 45 ° with the normal of the surface of the molded body under a fluorescent lamp having an illuminance of 1000 Lx, and the luminance was visually evaluated in three stages as follows.
○: Appropriate glare is felt Δ: The metal-specific shine is insufficient. Alternatively, it has a glare feeling but is excessive x: it does not have a metal-specific shine (i) surface appearance (color tone)
The appearance of the obtained laminated bottle was visually observed, and the color tone was evaluated in two stages as follows.
○: There are no color spots on the surface of the laminated bottle, and the color tone is uniform.
X: Color spots or aggregates are formed on the surface of the laminated bottle.

Example 1
A slurry having a molar ratio of terephthalic acid and ethylene glycol of 1 / 1.6 is continuously fed to an esterification reaction vessel in which bis (β-hydroxyethyl) terephthalate and its low polymer are present, at a temperature of 250 ° C. and pressure The reaction was carried out under the condition of 0.2 MPa, the residence time was 8 hours, and an ester oligomer with an esterification reaction rate of 95% was continuously obtained. 39.74 kg of this ester oligomer was charged into a melt polycondensation reaction vessel, and 1,4-butanediol was added in an amount (15.3 kg) such that the molar ratio of ethylene glycol to 1,4-butanediol was 60/40, Furthermore, germanium dioxide was added as a polycondensation catalyst, and hindered phenol-based antioxidants (ADEKA: Adeka Stub AO-60) were each added in an amount of 0.6% by mass, gradually reduced in pressure, and finally Thus, a polycondensation reaction was carried out at a pressure of 0.9 hpa and a temperature of 250 ° C. for 4 hours, and then discharged by a conventional method to obtain a chip-like polyester resin (A). This polyester resin (A) had the properties [η] = 0.63, carboxyl end group concentration = 23.8, and Tm = 183 ° C.
“Novatec HD, HB321R” manufactured by Nippon Polyethylene Co., Ltd. was used as the polyolefin resin (B). In addition, “Modic F532” manufactured by Mitsubishi Chemical Corporation was used as the adhesive layer (C). As the metallic pigment, “NME020T2” manufactured by Toyo Aluminum Co., Ltd. (polyethylene masterbatch with a solid content concentration of 70 mass%, the average particle diameter of the contained aluminum powder was 20 μm) was used.
After using this polyester resin (A), polyolefin resin (B), and adhesive layer (C) and drying, a metallic pigment is added to the polyester resin (A) (the content of the metallic pigment is in the bottle mass). 0.5% by mass) and using a direct blow molding machine (MSE-C33A manufactured by Tahara), the resin is extruded at an extrusion temperature of 220 ° C. to form a cylindrical parison (length of parison 3 cm long) Is formed when the parison is in a softened state, and is sandwiched between molds to form the bottom, blown, and blown to have an average wall thickness of 0.7 mm, an inner diameter of 4.0 cm, and a height. A 11.0 cm cylindrical laminated bottle (a hollow container having an internal volume of 100 cc, a mass ratio of polyester resin (A) / polyolefin resin (B) / adhesive layer (C) of 10/80/10) was obtained. At this time, the polyester resin (A) was the outer layer, the adhesive layer (C) was the intermediate layer, and the polyolefin resin (B) was the inner layer, and three types of resins were simultaneously melt extruded and blow molded.

Examples 2-3 and Comparative Examples 1-2
A polyester resin (A) was obtained in the same manner as in Example 1 except that the composition was changed so that the composition of the polyester resin (A) was as shown in Table 1.
And the direct blow molding was performed like Example 1 except having used the obtained polyester resin (A), and the lamination bottle was obtained.

Example 4
A polyester resin (A) was obtained in the same manner as in Example 1 except that the polycondensation reaction temperature was changed to 280 ° C.
And the direct blow molding was performed like Example 1 except having used the obtained polyester resin (A), and the lamination bottle was obtained.

Examples 5-6, Comparative Examples 5-6
Direct blow molding was performed in the same manner as in Example 1 except that the amount of the metallic pigment added to the polyester resin (A) was changed so that the content in the laminated bottle was the value shown in Table 1, and the laminated bottle was used. Got.

Comparative Example 3
A polyester resin (A) was obtained in the same manner as in Example 1 except that the polycondensation reaction time was changed to 2.5 hours.
And the direct blow molding was performed like Example 1 except having used the obtained polyester resin (A), and the lamination bottle was obtained.

Comparative Example 4
Direct blow molding was performed in the same manner as in Example 1 except that only the polyolefin resin (B) was used without using the polyester resin (A) to obtain a bottle made of only the polyolefin resin (B).

Example 7
Using the same polyester resin (A), polyolefin resin (B) and adhesive layer (C) as in Example 1, inorganic particles (titanium dioxide Ishihara Sangyo Co., Ltd. CR-63) were added to the polyolefin resin (B). Direct blow molding was performed in the same manner as in Example 1 except that the content was 1.0% by mass in the laminated bottle to obtain a laminated bottle.

Examples 8-9, Comparative Examples 8-9
Direct blow molding was performed in the same manner as in Example 7 except that the amount of inorganic particles added in the polyolefin resin (B) was changed so that the content in the laminated bottle was the value shown in Table 1. Got.

Comparative Example 7
Direct blow molding was performed in the same manner as in Example 7 except that only the polyolefin resin (B) was used without using the polyester resin (A) to obtain a bottle made of only the polyolefin resin (B).

Example 10
Using the same polyester resin (A), polyolefin resin (B) and adhesive layer (C) as in Example 1, inorganic particles (titanium dioxide Ishihara Sangyo Co., Ltd. CR-63) were added to the polyolefin resin (B). The content was 1.0% by mass in the laminated bottle. Then, the metallic pigment used in Example 1 was added to the adhesive layer (C) so that the content was 0.1% by mass in the laminated bottle. Otherwise, direct blow molding was performed in the same manner as in Example 1 to obtain a laminated bottle.

Example 11
Using the same polyester resin (A), polyolefin resin (B) and adhesive layer (C) as in Example 1, inorganic particles (titanium dioxide Ishihara Sangyo Co., Ltd. CR-63) were added to the polyolefin resin (B). Direct blow molding was performed in the same manner as in Example 5 except that the content was 1.0% by mass in the laminated bottle to obtain a laminated bottle.

Table 1 shows the characteristic values of the polyester resin (A) used in Examples 1 to 11 and Comparative Examples 1 to 9 and the evaluation results of the laminated bottles.

  As is clear from Table 1, since the polyester resins (A) used in Examples 1 to 11 satisfied the characteristic values defined in the present invention, the surface appearance (glossiness, luminance, A laminated bottle excellent in color tone could be obtained.

On the other hand, the polyester resin (A) obtained in Comparative Example 1 had a high melting point because the amount of 1,4-butanediol added was small. For this reason, under the direct blow molding conditions of Example 1, it was not possible to melt at an extrusion temperature of 220 ° C., and an unmelted product was generated, and a laminated bottle could not be obtained.
The polyester resin obtained in Comparative Example 2 had a high melting point because (A) had a large amount of 1,4-butanediol added. For this reason, the direct blow molding conditions of Example 1 could not be melted at an extrusion temperature of 220 ° C., and a laminated bottle could not be obtained.

Since the polyester resin obtained in Comparative Example 3 had a low intrinsic viscosity, the drawdown at the time of molding increased, and a laminated bottle could not be obtained. Since the bottle obtained in Comparative Example 4 was composed only of the polyolefin resin (B), it did not have a glossy surface appearance as compared with the bottle in which the polyester was arranged on the outside.
The bottle obtained in Comparative Example 5 was inferior in surface appearance (luminance) because the content of the metallic pigment in the polyester resin (A) was small. In Comparative Example 6, since the content of the metallic pigment in the polyester resin (A) was too much, the moldability was inferior, and the obtained laminated bottle had an excessive surface glare feeling, and the aggregation of the metallic pigment was also observed. It was.
Since the bottle obtained in Comparative Example 7 was composed only of the polyolefin resin (B), it did not have a glossy surface appearance as compared with the bottle in which the polyester was arranged on the outside. The bottle obtained in Comparative Example 8 was inferior in surface appearance (color tone) (with color spots and uneven color tone) because the content of inorganic particles in the polyolefin resin (B) was small. . Since the bottle obtained in Comparative Example 9 contained too much inorganic particles in the polyolefin resin (B), aggregation of inorganic particles was observed on the bottle surface and the surface appearance (color tone) was inferior.

Claims (3)

A laminated bottle using a polyester resin (A) as an outer layer and a polyolefin resin (B) as an inner layer. The polyester resin (A) has an acid component as a main component of terephthalic acid and a glycol component as ethylene. The main component is glycol and 1,4-butanediol, the mass ratio of ethylene glycol to 1,4-butanediol is 80/20 to 30/70, the crystal melting point is 160 to 220 ° C., and the intrinsic viscosity is 0. 0.5 to 1.0, and at least one of the polyester resin (A) and the polyolefin resin (B) contains 0.05 to 3.0% by mass of inorganic particles and / or pigments. The laminated bottle according to claim 1, further comprising an adhesive layer (C) between the layer of the polyester resin (A) and the layer of the polyolefin resin (B). The method for producing a laminated bottle according to claim 1 or 2, wherein the polyester resin (A) is an outer layer and the polyolefin resin (B) is an inner layer, and both resins are simultaneously melt extruded and blow-molded.