JP7093070B2 - Manufacturing method of laminated bottles and laminated bottles - Google Patents

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 the laminated bottle has an excellent surface appearance.

Polyethylene terephthalate (PET) has excellent mechanical properties, chemical stability, transparency, etc., is inexpensive, and is widely used as various sheets, films, containers, etc., especially in recent years, carbonated drinks, The growth of hollow container (bottle) applications such as fruit juice beverages, liquid seasonings, cooking oil, liquor, and wine is remarkable. Moreover, since there is less concern about residual monomers and harmful additives as in the case of hollow molded products made of vinyl chloride resin, and the hygiene and safety are high, the replacement of conventional bottles made of vinyl chloride resin or the like is progressing.

Generally, when manufacturing plastic bottles, melt-plasticized resin is used as a die orifice because of its ease of molding, high productivity, and relatively low equipment costs for molding machines and dies. A so-called direct blow molding method is adopted in which a cylindrical parison is formed by extruding through a mold, sandwiched between molds, and air is blown into the inside. In the case of this direct blow molding, it is necessary to prevent the parison extruded in the molten state from drawing down during blow molding in order to carry out the molding smoothly, and therefore, a high melt viscosity is required for the resin used. Will be done. Therefore, as a resin having a high melt viscosity, vinyl chloride resin, polyolefin resin and the like are widely used in direct blow molding.

Polyolefin-based resins are widely used in bottle containers because they have excellent moldability and are inexpensive. Patent Document 1 describes multi-layer blow molding formed from polyester-based resins and polyolefin-based resins. Multi-layer structures such as containers and multi-layer sheets have been proposed.

In the multilayer structure described in Patent Document 1, it is shown that the polyester-based 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 copolymerization component in order to enable plasticization and extrusion at a temperature equivalent to that of a polyolefin resin. Such amorphous polyester resin tends to cause fusion between chips, and it is necessary to perform the drying treatment at a low temperature before use, so that the drying treatment takes time and the operability is improved. 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, a polyamide, and a polyolefin are laminated. A polyester laminate having has been proposed. It is described that the laminate described in Patent Document 2 has a high crystallization rate and is excellent in gas barrier property, transparency, and heat resistance.

However, in Patent Document 2, what is specifically shown in the examples is only the 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 exemplified, and no laminate in which the first polyester and the polyolefin are laminated is shown.

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

In recent years, plastic bottles made of polyester resin or polyolefin resin have been adopted for applications that require high decorativeness such as for cosmetics, and have excellent surface appearance such as those with excellent surface gloss and those with excellent color tone. There is also a high demand for excellent bottles.

Japanese Unexamined Patent Publication No. 5-193059 Japanese Unexamined Patent Publication No. 10-211684

The present invention solves the above-mentioned problems and can simultaneously melt-extrude a polyester resin and a polyolefin resin at the same temperature for molding. The polyester resin is used as an outer layer and the polyolefin resin is used as an inner layer. It is a technical issue to provide a laminated bottle having an excellent surface appearance.

The present inventor has arrived at the present invention as a result of diligent studies in order to solve the above problems.
That is, the gist of the present invention is the following (a) to (c).
(A) A laminated bottle in which the polyester resin (A) is used for the outer layer and the polyolefin resin (B) is used for the inner layer. The polyester resin (A) has an acid component of terephthalic acid as a main component and glycol. The main components are ethylene glycol and 1,4-butanediol, and the mass ratio of ethylene glycol and 1,4-butanediol is 80/20 to 30/70, the crystal melting point is 160 to 220 ° C, and the limit. The laminate has 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 pigment. Bottle.
(B) The laminated bottle according to (a), wherein the laminated bottle has an adhesive layer (C) between the layer of the polyester resin (A) and the layer of the polyolefin resin (B).
(C) The laminated bottle according to (a) or (b), wherein both resins are melt-extruded and blow-molded at the same time, with the polyester resin (A) as the outer layer and the polyolefin resin (B) as the inner layer. Production method.

The laminated bottle of the present invention uses the polyester resin (A) for the outer layer and the polyolefin resin (B) for the inner layer, but the polyester resin (A) has a specific composition and has a relatively low crystal melting point. Therefore, it can be obtained by molding at the same molding temperature as the polyolefin resin. Further, since the polyester resin (A) in the present invention is crystalline, it is difficult for the chips to adhere to each other during storage of the raw materials, the drying process can be performed at a high temperature in a short time, and the operability is excellent. It is a thing.
Further, the laminated bottle of the present invention contains a specific amount of inorganic particles and pigments in the polyester resin (A) and the polyolefin resin (B), and the surface glossiness and color tone depend on the types of the inorganic particles and pigments used. Can be excellent. Furthermore, the laminated bottle of the present invention is also excellent in decorativeness (particularly printability) by using the polyester resin (A) having a specific composition for the outer layer.
As described above, the laminated bottle of the present invention can be obtained with good moldability, has an excellent surface appearance, and is also excellent in decorativeness, so that it can be used for various purposes.

Hereinafter, the present invention will be described in detail.
The polyester resin (A) in the present invention has an acid component containing terephthalic acid (hereinafter, may be abbreviated as TPA) as a main component, and terephthalic acid is 90 mol% or more of the acid component. It is preferably 95 mol% or more. Terephthalic acid, as known as the acid component of polyethylene terephthalate, contributes to imparting favorable physical properties common to polyesters in general. If 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) contains ethylene glycol (hereinafter, may be abbreviated as EG) and 1,4-butanediol (hereinafter, may be abbreviated as BD) as main components. Of these, the ratio of both components is preferably 90 mol% or more, more preferably 95 mol% or more.

The mass ratio (EG / BD) of the two is 80/20 to 30/70, and more preferably 70/30 to 40/60. If it is out of this range, the melting point of the polyester resin becomes high. In addition, the crystallinity of the polyester resin deteriorates, tetrahydrofuran is generated during the polycondensation reaction, and the thermal stability of the polyester resin deteriorates. Therefore, it is difficult to perform molding at a low temperature in accordance with the molding temperature of the polyolefin resin.

Further, as the component constituting the polyester resin (A), in addition to the above-mentioned terephthalic acid, ethylene glycol and 1,4-butanediol, other components are copolymerized as long as the object of the present invention is not impaired. You may. Other such 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, etc. Bisphenol S and the like can be mentioned.

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

The polyester resin (A) of the present invention has a crystal melting point, and the crystal melting point is 160 to 220 ° C, preferably 180 to 200 ° C. If 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 the temperature exceeds 220 ° C., the heat treatment temperature at the time of molding must be raised, which is disadvantageous in terms of cost and cannot be adjusted to the molding temperature of the polyolefin resin. Furthermore, it is necessary to raise the kneading temperature even when the inorganic particles are contained, and the dispersibility of the inorganic particles is also inferior.

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

When the ultimate viscosity is less than 0.5, the viscosity of the resin is low, so that the drawdown of the parison is large during blow molding, and the obtained molded product tends to have uneven thickness. On the other hand, when the ultimate viscosity exceeds 1.0, it is necessary to raise the temperature at the time of molding, which is disadvantageous in terms of cost and tends to be inferior in the dispersibility of the inorganic particles. It is inferior in operability because the kneading temperature is raised and it is necessary to knead for a long time.

Further, the polyester resin (A) preferably has a carboxyl-terminal group concentration of 30 equivalents / t or less, more preferably 28 equivalents / t or less, and further preferably 26 equivalents / t or less. By setting the concentration of the carboxyl terminal group of the polyester resin (A) to 30 equivalents / 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 performed. It will be possible. When the carboxyl terminal group concentration exceeds 30 equivalents / t, even if the ultimate viscosity of the resin is in the above range, the heat treatment during blow molding causes thermal decomposition of the resin, resulting in resin. The viscosity decreases. For this reason, the drawdown of the parison becomes large, which makes 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. The content of these needs to be 0.05 to 3.0% by mass in the laminated bottle. That is, only the polyester resin (A), only the polyolefin resin (B), and both resins may contain inorganic particles and / or pigments, but in either case, the content of the inorganic particles or pigments in the laminated bottle is 0. It is necessary to set it to 0.05 to 3.0% by mass, and it is particularly preferable to set the content of inorganic particles and pigments to 0.2 to 2.8% by mass.
If the content of the inorganic particles and pigments in the laminated bottle is less than 0.1% by mass, the desired color tone and the like are not exhibited. On the other hand, if it exceeds 3.0% by mass, aggregation of inorganic particles and pigments occurs, the operability deteriorates, the surface appearance of the obtained laminated bottle deteriorates, the quality becomes inferior, and the transparency is deteriorated. It will be inferior in glossiness.

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

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

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

Further, the polyester resin (A) may contain an antioxidant. Above all, the hindered phenolic antioxidant is preferably added so as to be 0.01 to 2.0% by mass in the polyester resin, and particularly preferably 0.1 to 1.0% by mass. ..
By adding an appropriate amount of a hindered phenolic antioxidant, it has the effect of suppressing the thermal decomposition of the phthalic acid component, and the color tone of the polyester resin becomes good. Further, the antioxidant is decomposed to generate pentaerythritol (a tetrafunctional component), which is incorporated into the molecular chain of the polyester to increase the viscosity of the polyester resin.

If the amount of the hindered phenolic antioxidant is less than 0.01% by mass, it becomes difficult to achieve the above effects. On the other hand, if it exceeds 2.0% by mass, the possibility of gelation increases in the polycondensation reaction and the polyester resin tends to be colored, which is not preferable.

Examples of hindered phenolic antioxidants include triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenylpropionate]] and 1,6-hexanediol-bis [ 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, octadecyl-3- (3,5-di-t-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 antioxidant as described above, as an antioxidant, for example, phosphite, phosphoric acid, trimethylphosphite, triphenylphosphite, tridecylphos. Phosphoric compounds such as phyto, trimethyl phosphate, tridecyl phosphate, and triphenyl phosphate can be used, and these phosphorus compounds may be used alone or in combination of two or more. Further, in order to suppress coloring due to thermal decomposition of the polyester resin, additives such as a cobalt compound such as cobalt acetate, a manganese compound such as manganese acetate, an anthraquinone dye compound, and a copper phthalocyanine compound may be contained.

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

Specifically, for example, it can be manufactured by the following method.
First, ethylene glycol and terephthalic acid are contained in an esterification reaction tank in which bis- (β-hydroxyethyl) terephthalate or a low polymer thereof is present at a temperature of 230 to 250 ° C. under nitrogen gas suppression. A slurry having a molar ratio of 1.1 to 2.0 is continuously added to continuously obtain an ester oligomer having an average degree of polymerization of 10 or less with a residence time of 7 to 8 hours. Next, the ester oligomer composed of terephthalic acid and ethylene glycol is transferred to a melt polycondensation reaction can, and the mass ratio of 1,4-butanediol is 80/20 to 30/70 of ethylene glycol / 1,4-butanediol. Add in an amount within the range of, and carry out the reaction at 200 to 230 ° C. If the reaction temperature is less than 200 ° C., the reaction will only be slowed down, and the ester oligomer may solidify. Further, when the temperature exceeds 230 ° C., 1,4-butanediol is decomposed into tetrahydrofuran during the reaction, and a polyester resin having a predetermined ratio of 1,4-butanediol cannot be obtained.

After further adding a polycondensation catalyst, the temperature of the melt polycondensation reaction can is raised to 200 to 250 ° C., and the melt polycondensation reaction is carried out under a reduced pressure of 0.01 to 13.3 hPa until the predetermined extreme 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 dispensed into a large number of rods by extruding from a nozzle using gas pressure, and is cut into chips. Obtained as a form.

In order to make the carboxyl terminal group concentration of the polyester resin (A) 30 equivalents / t or less, as described above, the mass ratio of butanediol to ethylene glycol / butanediol is 80 in the ester oligomer composed of terephthalic acid and ethylene glycol. It is achieved by adding in an amount in the range of / 20 to 30/70 and performing 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 obtained polyester resin is very important, it is preferable to use a germanium compound. Examples of the germanium or antimony compound include oxides, inorganic acid salts, organic acid salts, halides, sulfides and the like thereof. These polycondensation catalysts are in the range of 5 × 10 ^-5 mol to 8.0 × 10 ^-4 mol, especially 6 × 10 ^-5 mol to 5.0 × 10 per 1 mol of the acid component of the produced polyester resin. It is preferable to use the amount so as to be within the range of ^-4 mol.

When the solid phase polymerization reaction step is performed after the melt polymerization reaction step, the polyester resin is dried and crystallized in advance, and then usually under reduced pressure or under an inert gas such as nitrogen, from the melting point of the polyester. It is also preferable to react the polyester in the reactor for 3 hours to 50 hours at a low temperature of 20 to 30 ° C. By carrying out the solid phase polymerization reaction, the ultimate viscosity can be further increased or the amount of the contained oligomer can be further reduced.

As a method of containing the inorganic particles and the pigment in the polyester resin (A) and the polyolefin resin (B), the resin and the inorganic particles and the pigment are dry-blended and melt-kneaded before molding the laminated bottle to form a resin composition. It is preferable to prepare an object. Then, it is preferable to mold the laminated bottle using this resin composition.

When the resin contains inorganic particles or pigments, a master chip containing the inorganic particles or pigments in the resin at a high concentration (about 5 to 20% by mass) is prepared in advance, and the master chip is used when molding the laminated bottle. It is also preferable to adopt a method of melt-kneading the chips together with a resin containing no inorganic particles or pigments.
In either method, when the resin and the inorganic particles or the 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, among others. Polyethylene and polypropylene are particularly preferable. Such polyolefins may be used alone or in combination of two or more.

Such a polyolefin resin can be produced by a conventionally known production method. Further, if necessary, additives such as a colorant, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant, and a lubricant may be contained.

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

The laminated bottle of the present invention is made by using the polyester resin (A) for the outer layer and the polyolefin resin (B) for the inner 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, and 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 should be 0.5 / 9.5 to 5/5 for the polyester resin (A) / polyolefin resin (B). Is preferable, and 1/9 to 3/7 is particularly preferable.

Furthermore, the laminated bottle of the present invention is excellent in decorativeness by using such a polyester resin (A) for the outer layer. Above all, the ink is well printed when printing (silk printing), and the printability is excellent. Generally, when printing is performed on a bottle using a polyolefin resin as an outer layer, it is necessary to perform a treatment such as roughening the surface because the ink does not adhere well. There is no need to perform any surface treatment.

When the laminated bottle of the present invention contains inorganic particles or pigments only in the polyester resin (A) of the outer layer, the color tone can be easily adjusted in consideration of printing on the bottle surface by post-processing.
On the other hand, when the laminated bottle of the present invention contains inorganic particles or pigments only in the polyolefin resin (B) in the inner layer, the polyester resin (A) in the outer layer is a transparent layer, so that the color of the inner layer has a glossy feeling. Is added, and a bottle with excellent color tone can be obtained.

Further, since the polyester resin (A) is crystalline, it can be subjected to a dry heat treatment when obtaining the polyester resin, and moisture control is easy. If the polyester resin is amorphous, the dry 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 water, when both are melt-extruded at the same time, the productivity deteriorates if they are affected by the water content of the polyester resin. That is, by using the polyester resin (A) of the present invention, moisture control becomes easy, productivity is good, and it becomes possible to obtain a laminated bottle of excellent quality.

Further, the laminated bottle of the present invention preferably has an adhesive layer (C) between the layer of the polyester resin (A) and the layer of the polyolefin resin (B).
As described above, the layer of the polyester resin (A) and the layer of the polyolefin resin (B) have good followability and are difficult to peel off, so that a laminated bottle can be obtained with good productivity, but between the two layers. By having the adhesive layer (C), peeling is less likely to occur, and a laminated bottle in which both resin layers are well adhered can be obtained.

As the adhesive layer (C), it is preferable to use a polyofin-based adhesive resin or an amorphous polyester resin. As the polyofin-based adhesive resin, one in which a polar group is introduced into a non-polar polyolefin is preferable, and the "Modic" (registered trademark) series manufactured by Mitsubishi Chemical Corporation and the "Admer" (registered trademark) series manufactured by Mitsui Chemicals Corporation are preferable. Is preferable, and among them, "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, for example, by a known method of a divalent alcohol component and a divalent carboxylic acid component by a melt polycondensation method such as a direct ester method or a transesterification method. However, from the viewpoint of mechanical strength and heat resistance of the molded product, it is preferable that the number average molecular weight thereof is 10,000 or more. In order to obtain an amorphous polyester resin having such a molecular weight, a method of stopping the viscosity of the polyester melt at the time of polymerization at an appropriate place, a method of adding a monofunctional alcohol or a carboxylic acid in advance, and the like can be mentioned.

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, and the like. Polyethylene glycol, cyclohexanedimethanol, ethylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol S, 2- (9,10-dihydro-9-oxa-10-oxide-phosphaphenanthrene) bis-methylsuccinate (2-Hydroxyethyl) -esters and the like. These raw materials do not necessarily have to be used alone, and two or more kinds may be copolymerized and used. Among these, it is preferable to use ethylene glycol and neopentyl glycol in coexistence. In addition, trihydric or higher alcohols such as trimethylolpropane, pentaerythritol, and glycerin can also be used.

The divalent carboxylic acid components include terephthalic acid, isophthalic acid, oxalic acid, malonic acid, succinic acid, adipic acid, itaconic acid, azelaic acid, sebacic acid, diiodic acid diacid, naphthalenedicarboxylic acid, diphenic acid, and dodecaneni. Acids, cyclohesandicarboxylic acids and the like can be mentioned. These raw materials do not necessarily have to be used alone, and two or more kinds may be copolymerized and used. Among these, it is preferable to use terephthalic acid, isophthalic acid, and adipic acid in coexistence. Further, carboxylic acids having a trivalent value or higher, such as trimellitic acid and pyromellitic acid, can also be used. Further, it is also possible to use an alkyl ester body such as the above-mentioned dimethyl ester body. Further, raw materials having a ring structure such as ε-caprolactone and γ-butyrolactone can also be used.

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

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

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

In manufacturing the laminated bottle of the present invention, a conventionally known blow molding method can be adopted. As a blow molding method, a melt-plasticized resin is extruded through a die orifice to form a cylindrical parison, which is sandwiched between molds and blown into the inside, or a parison is formed by injection molding. , A stretch blow molding method in which this is stretch blow molded, and among them, a direct blow molding method is suitable.

At this time, direct blow molding is performed using a general-purpose multi-layer direct blow molding machine equipped with two or more melt extruders, or a multi-layer parison is performed using a stretch blow molding machine equipped with two or more melt extruders. It is possible to obtain a blow-molded article by manufacturing and stretching-blow-molding the product. The temperature of each cylinder and nozzle of the molding machine is preferably in the range of 160 to 250 ° C.

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

(C) Composition of Polyester Resin (A) The polyester resin (A) was dissolved in a mixed solvent having a dose ratio of deuterated hexafluoroisopropanol and deuterated chloroform at 1/20, and LA-400 manufactured by JEOL Ltd. was dissolved. Type NMR apparatus 1H-NMR was measured, and the copolymerization amount and content were determined from the integrated intensity of the proton peaks of each component in the obtained chart.
(D) Melting point (Tm) of polyester resin (A)
Measurement was performed at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC-7 type manufactured by PerkinElmer).
(E) Content of Inorganic Particles and Pigments in Polyester Resin (A) The polyester resin (A) is melt-molded into a disk-shaped molded plate having a diameter of 3 cm and a thickness of 1 cm, and the fluorescent X-ray analyzer ZSX Primus manufactured by Rigaku Co., Ltd. is melt-molded. The content was measured using.

(F) Moldability Using 100 of the obtained laminated bottles as samples, the thickness of the body of 100 samples was measured, and the difference in thickness between the thickest part and the thinnest part was up to 0.30 mm. It was passed and the number of passed samples was shown. The number of passing samples is preferably 90 or more.
(G) Surface appearance (glossiness)
The appearance of the obtained laminated bottle was visually observed, and the presence or absence of glossiness was determined and evaluated in two stages as follows.
〇: Glossy ×: No gloss (h) Surface appearance (brightness)
The appearance of the obtained laminated bottle was observed from the direction of an angle of 45 ° formed with the normal of the surface of the molded body under a fluorescent lamp having an illuminance of 1000 Lx, and the brightness was visually evaluated in three stages as follows.
◯: Has an appropriate glare feeling Δ: The brilliance peculiar to metal is insufficient. Alternatively, it has a glaring feeling but is excessive. ×: Does not have the brilliance peculiar to metal (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 is no color unevenness on the surface of the laminated bottle, and the color tone is uniform.
X: Color spots or agglomerates are formed on the surface of the laminated bottle.

Example 1
An esterification reaction can containing bis (β-hydroxyethyl) terephthalate and its low polymer is continuously supplied with a slurry having a molar ratio of terephthalic acid and ethylene glycol of 1 / 1.6, at a temperature of 250 ° C. and a pressure. The reaction was carried out under the condition of 0.2 MPa, the residence time was 8 hours, and ester oligomers having an esterification reaction rate of 95% were continuously obtained. 39.74 kg of this ester oligomer was charged into a melt polycondensation reaction can, 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. Further, germanium dioxide was added as a polycondensation catalyst, and a hindered phenolic antioxidant (made by ADEKA: Adecastab AO-60) was added in an amount of 0.6% by mass, and the pressure was gradually reduced to final. The polycondensation reaction was carried out at a pressure of 0.9 hpa and a temperature of 250 ° C. for 4 hours, and the polycondensation reaction was carried out by a conventional method to obtain a chip-shaped polyester resin (A). This polyester resin (A) had the characteristics of [η] = 0.63, carboxyl-terminal group concentration = 23.8, and Tm = 183 ° C.
As the polyolefin resin (B), "Novatec HD, HB321R" manufactured by Japan Polyethylene Corporation was used. Further, as the adhesive layer (C), "Modic, F532" manufactured by Mitsubishi Chemical Corporation was used. As the metallic pigment, "NME020T2" manufactured by Toyo Aluminum K.K. (polyethylene masterbatch having a solid content concentration of 70% by mass, the average particle size of the aluminum powder contained therein was 20 μm) was used.
The polyester resin (A), the polyolefin resin (B), and the adhesive layer (C) are used, dried, and then a metallic pigment is added to the polyester resin (A) (the content of the metallic pigment is in the bottle mass. A direct blow molding machine (MSE-C33A manufactured by Tahara Co., Ltd.) was used to extrude the resin at an extrusion temperature of 220 ° C. to form a cylindrical parison (a parison diameter of 3 cm and a length of 3 cm). While the parison is in a softened state, it is sandwiched between molds to form the bottom, which is blown, and the average wall thickness of the body is 0.7 mm, the inner diameter is 4.0 cm, and the height is high. A 11.0 cm cylindrical laminated bottle (hollow container with an internal capacity of 100 cc, a mass ratio of polyester resin (A) / polyolefin resin (B) / adhesive layer (C) was 10/80/10) was obtained. At this time, three types of resins were simultaneously melt-extruded and blow-molded, with the polyester resin (A) as the outer layer, the adhesive layer (C) as the intermediate layer, and the polyolefin resin (B) as the inner layer.

Examples 2-3, Comparative Examples 1-2
A polyester resin (A) was obtained in the same manner as in Example 1 except that the composition of the polyester resin (A) was changed so as to be as shown in Table 1.
Then, direct blow molding was performed in the same manner as in Example 1 except that the obtained polyester resin (A) was used, to obtain a laminated bottle.

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.
Then, direct blow molding was performed in the same manner as in Example 1 except that the obtained polyester resin (A) was used, to obtain a laminated bottle.

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 became the value shown in Table 1, and the laminated bottle was formed. 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.
Then, direct blow molding was performed in the same manner as in Example 1 except that the obtained polyester resin (A) was used, to obtain a laminated bottle.

Comparative Example 4
Direct blow molding was performed in the same manner as in Example 1 except that the polyester resin (A) was not used and only the polyolefin resin (B) was used, 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 (CR-63 manufactured by Ishihara Sangyo Co., Ltd.) are added to the polyolefin resin (B). Direct blow molding was carried out in the same manner as in Example 1 except that the content was adjusted to 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 the inorganic particles added to the polyolefin resin (B) was changed so that the content in the laminated bottle became the value shown in Table 1, and the laminated bottle was formed. Got

Comparative Example 7
Direct blow molding was performed in the same manner as in Example 7 except that the polyester resin (A) was not used and only the polyolefin resin (B) was used, 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 (CR-63 manufactured by Ishihara Sangyo Co., Ltd.) are added to the polyolefin resin (B). , The content was adjusted to 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 in the laminated bottle was 0.1% by mass. Other than that, 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 (CR-63 manufactured by Ishihara Sangyo Co., Ltd.) are added to the polyolefin resin (B). Direct blow molding was carried out in the same manner as in Example 5 except that the content was adjusted to 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, the polyester resins (A) used in Examples 1 to 11 satisfy the characteristic values specified in the present invention, and therefore have good moldability and surface appearance (glossiness, brightness, etc.). We were able to obtain a laminated bottle with excellent color tone).

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. Therefore, under the conditions of direct blow molding of Example 1, unmelted matter could not be obtained at an extrusion temperature of 220 ° C., and a laminated bottle could not be obtained.
The polyester resin (A) obtained in Comparative Example 2 had a high melting point because the amount of 1,4-butanediol added was large. Therefore, under the conditions of direct blow molding of Example 1, it was not possible to melt 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 extreme viscosity, the drawdown during molding became large, 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 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 large, the moldability was inferior, and the obtained laminated bottle had an excessive surface glare, and aggregation of the metallic pigment was also observed. Was done.
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 polyester was arranged on the outside. The bottle obtained in Comparative Example 8 was inferior in surface appearance (color tone) due to the low content of inorganic particles in the polyolefin resin (B) (color spots and non-uniform color tone). .. In the bottle obtained in Comparative Example 9, since the content of the inorganic particles in the polyolefin resin (B) was too large, aggregation of the inorganic particles was observed on the surface of the bottle, and the surface appearance (color tone) was inferior.

Claims (3)

A laminated bottle in which the polyester resin (A) is used for the outer layer and the polyolefin resin (B) is used for the inner layer. The polyester resin (A) contains terephthalic acid in an acid component of 90 mol% or more in the acid component. The glycol component contains ethylene glycol and 1,4-butanediol in an amount of 90 mol% or more in the glycol component , and the molar ratio of ethylene glycol to 1,4-butanediol is 70/30 to 40/60 , and the crystal melting point is high. Is 181 to 195 ° C., the ultimate viscosity is 0.63 to 0.69 , and at least one of the polyester resin (A) and the polyolefin resin (B) contains 0.1 to 3.0% by mass of inorganic particles and / or pigments. A laminated bottle characterized by being plastic. The laminated bottle according to claim 1, wherein the laminated bottle has 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 both resins are simultaneously melt-extruded and blow-molded with the polyester resin (A) as the outer layer and the polyolefin resin (B) as the inner layer.