JP2015071439A - Blow-molding container and manufacturing method of blow-molding container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-molding container which can suppress the occurrence of a defect such as gel-like fish-eyes and streaks due to fusion molding, coloration and smell, has superior appearance, permits satisfactory self-purging property of EVOH-containing resin composition to be used, has quality of adequate strength, etc., and can be manufactured at a low cost.SOLUTION: A blow molding container includes a first layer 1 which consists essentially of ethylene-vinylalcohol copolymer (I) and a second layer and so on 2 to 4 made of thermoplastic resin if desired. Therein, the first layer contains saturated ketone (II) and the content of the saturated ketone (II) in the first layer is 0.01 to 100 ppm.

Description

  The present invention relates to a blow molded container and a method for producing a blow molded container.

  An ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is a polymer material having excellent gas barrier properties such as oxygen, oil resistance, and non-chargeability. Therefore, the EVOH-containing resin composition is formed into a container, a film, a sheet, or the like, and is widely used as a packaging material or the like. In particular, as a blow molded container, a multilayer structure composed of a layer made of the EVOH-containing resin composition and a layer of another thermoplastic resin excellent in moisture resistance, impact resistance and the like is widely adopted.

  In the production of the blow molded container, melt molding is generally performed. However, defects such as gel-like butts and streaks may occur due to the melt molding, and the appearance of the molded product may be impaired. In addition, the gel-like material not only impairs the appearance of the molded product but also causes deterioration in performance, so that it is necessary to suppress these occurrences.

  Also, in the blow molding container production process, it is necessary to temporarily stop the operation of the melt molding apparatus and restart it after a certain period in order to change the resin, stop production on holidays, etc., or replace the mold. . In this case, a small amount of the resin composition remaining in the melt molding apparatus deteriorates during the temperature rising / falling process of the apparatus, becomes a gel at the time of restart, and deteriorates the quality such as the appearance and strength of the molded product. Inconvenience arises. Therefore, after restarting the apparatus, it is necessary to wait for a certain period of time to operate until a gel or the like disappears and the appearance of the molded product is restored to a normal state. From the viewpoint of production cost, it is preferable that the time taken to recover to the normal state is short, that is, the self-purge property is good. However, the self-purge property of the conventional EVOH-containing resin composition is hardly good.

  Therefore, as an EVOH-containing resin composition with improved self-purge properties, (1) a resin in which a polyolefin resin, a carboxylic acid-modified polyolefin resin, and an alkaline earth metal salt of a lower fatty acid having 9 or less carbon atoms are added to the EVOH resin at a specific ratio Composition (see JP-A-5-255554), (2) EVOH-containing resin composition containing a specific viscosity and a carboxylic acid having a molecular weight of less than 75 and an alkaline earth metal salt (JP-A-5-255554) No. 2001-234008) is known. However, since these EVOH-containing resin compositions contain an alkaline earth metal, the molded product may be colored, and the self-purge property is not sufficient. In particular, the EVOH-containing resin composition of (1) described above is not affected by the above-described defects due to the addition of a polyolefin resin, even if long-time melt molding is performed. There is an inconvenience that happens. In addition, from the environmental point of view, it is necessary to consider the odor during molding.

JP-A-5-255554 JP 2001-234008 A JP 2007-31725 A

  The present invention has been made based on the circumstances as described above, and its purpose is to provide a blow-molded container excellent in appearance, in which the occurrence of defects such as gelled blisters and streaks due to melt molding, coloring and odor are suppressed. Is to provide. Another object of the present invention is to provide a blow molded container that has good self-purge properties during production, has sufficient strength and other quality, and can be produced at low cost.

The invention made to solve the above problems is
A blow-molded container comprising a first layer (hereinafter also referred to as “(1) layer”) comprising ethylene-vinyl alcohol copolymer (I) as a main component, wherein the (1) layer comprises a saturated ketone (II ), And the content of the saturated ketone (II) in the layer (1) is 0.01 ppm or more and 100 ppm or less.

  The blow-molded container has a saturated ketone (II) content in the specific range (1), thereby suppressing the occurrence of defects such as gelled blisters and streaks due to melt molding, coloring, and odor. The appearance is excellent. Moreover, since the layer (1) contains the specific amount of the saturated ketone (II), the self-purging property in the blow molding container manufacturing process is excellent, so that the manufacturing cost of the blow molding container can be reduced. .

  The saturated ketone (II) preferably has 3 to 8 carbon atoms, and the saturated ketone (II) is more preferably at least one selected from the group consisting of acetone, methyl ethyl ketone and 2-hexanone. Thus, the layer (1) contains the specific saturated ketone (II), so that the occurrence of defects such as gelled streaks and streaks due to melt molding, coloring and odor can be more effectively suppressed, The appearance can be further improved. Moreover, since the said (1) layer contains the said specific saturated ketone (II), since it is more excellent also in self purge property, the manufacturing cost of the said blow molding container can be reduced more.

  The layer (1) contains a conjugated polyene compound, and the content of the conjugated polyene compound in the layer (1) is preferably 0.01 ppm or more and 1,000 ppm or less.

  As described above, (1) the layer further contains the specific amount of the conjugated polyene compound, thereby suppressing the occurrence of defects such as gel-like defects, coloring, odor, and the like by suppressing oxidative deterioration during melt molding, The appearance can be further improved. Moreover, since the (1) layer contains the specific amount of the conjugated polyene compound, the self-purge property is further improved, and therefore the production cost of the blow molded container can be further reduced.

  The conjugated polyene compound is preferably at least one of sorbic acid and sorbate. As described above, by containing at least one of sorbic acid and sorbate as the conjugated polyene compound, it is possible to more effectively suppress oxidative deterioration during melt molding, and to prevent generation of defects such as gelled spots, coloring, and odor. It can suppress more effectively and can improve an external appearance more. In addition, since the layer (1) contains at least one of sorbic acid and sorbate as a conjugated polyene compound, the occurrence of gelled blisters and the like is suppressed even when melt-molded continuously for a long time, and impact resistance Blow molded containers can be obtained.

The blow-molded container is mainly composed of a thermoplastic resin which is disposed on the inner surface side and outer surface side of the layer (1) and whose solubility parameter calculated from the Fedors equation is 11 (cal / cm ³ ) ^1/2 or less. A pair of second layers (hereinafter also referred to as “(2) layers”) and a pair mainly composed of a carboxylic acid-modified polyolefin, disposed between the (1) layer and the pair of (2) layers. The third layer (hereinafter also referred to as “(3) layer”) is preferably provided.

  In addition to the (1) layer, the blow molded container can further improve the gas barrier property, oil resistance, impact resistance, and the like under high humidity by further including the (2) layer and the (3) layer. .

  The blow-molded container may include a fourth layer (hereinafter also referred to as “(4) layer”) containing the ethylene-vinyl alcohol copolymer (I), the thermoplastic resin, and the carboxylic acid-modified polyolefin. preferable.

  The blow molded container can further improve gas barrier properties, impact resistance, and the like under high humidity by further including the layer (4).

  It is preferable that the (4) layer is formed by using the collected materials of the (1) layer, (2) layer, and (3) layer in the blow molding container manufacturing process. The (4) layer is formed by using the recovered material of the (1) layer, (2) layer, and (3) layer in the blow molding container manufacturing process, thereby generating in the blow molding container manufacturing process. The burrs to be tested, products that have failed the test, etc. are reused in the (4) layer, so that the material resin can be used without waste, and the low cost is improved.

  In the blow molded container, the average thickness of the layer (1) is 5.0% or less of the average thickness of all layers, and the content of the ethylene-vinyl alcohol copolymer (I) in the layer (4) is 9 It is preferable that it is 0.0 mass% or less. In the blow molded container, the average thickness of (1) layer is 5.0% or less of the average thickness of all layers, and the content of the ethylene-vinyl alcohol copolymer (I) in the layer (4) is 9.0. When the content is less than or equal to mass%, impact resistance can be further improved while maintaining excellent gas barrier properties, oil resistance, appearance, self-purge properties, and the like.

  The blow molded container can be used as a fuel container. The blow molded container is excellent in gas barrier properties, oil resistance and the like, and is also excellent in appearance, so that it can be suitably used as a fuel container.

  The blow molded container can be used as a bottle. The blow molded container formed into a bottle shape is excellent in gas barrier properties, oil resistance, and the like, and is also excellent in appearance, and thus is suitably used for bottle containers for foods, cosmetics and the like.

  Moreover, the preferable manufacturing method of the said blow molding container has the process of carrying out blow molding using the resin composition which has ethylene-vinyl alcohol copolymer (I) as a main component, The said resin composition is saturated ketone (II). ) And the content of the saturated ketone (II) in the resin composition is 0.01 ppm or more and 100 ppm or less. According to the method for producing a blow molded container, since the occurrence of defects such as gelled blisters and streaks, coloring, and odor are suppressed, a blow molded container having an excellent appearance can be obtained. Moreover, since the resin composition used for the manufacturing method of the said blow molding container is excellent in self purge property, manufacturing cost can be reduced.

  In addition to having sufficient gas barrier properties and oil resistance as the characteristics of EVOH, the blow-molded container of the present invention includes (1) a specific amount of saturated ketone (II) in the layer, so that gel by melt molding Since the occurrence of defects such as irregularities and streaks, coloring and odor are suppressed, the appearance is excellent. In addition, since the blow molded container (1) contains the specific amount of saturated ketone (II) and has excellent self-purge properties in the manufacturing process, the manufacturing cost of the blow molded container can be reduced. it can. Therefore, the blow molded container is used for various applications, and particularly preferably used for a fuel container.

It is a typical fragmentary sectional view showing one embodiment of a blow molding container of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. Moreover, as long as there is no description in particular, the material illustrated may be used individually by 1 type, and may use 2 or more types together.

<Blow molded container>
The blow molded container 5 in FIG.
(1) Layer 1 mainly comprising ethylene-vinyl alcohol copolymer (I),
(2) A pair mainly composed of a thermoplastic resin which is disposed on the inner surface side and the outer surface side of the (1) layer and whose solubility parameter calculated from the Fedors equation is 11 (cal / cm ³ ) ^1/2 or less. Layer 2 of
(3) A pair of layers 3 which are arranged between the (1) layer and the (2) layer and mainly contain a carboxylic acid-modified polyolefin, and (4) the ethylene-vinyl alcohol copolymer (I), A layer 4 containing a thermoplastic resin having a solubility parameter calculated from the Fedors equation of 11 (cal / cm ³ ) ^1/2 or less and a carboxylic acid-modified polyolefin is provided. Specifically, the blow molded container 5 has (2) layer 2, (3) layer 3, (1) layer 1, (3) layer 3, and (4) layer from the container inner surface 6 toward the container outer surface 7. 4, (2) It has a multilayer structure in which layers 2 are laminated in this order. The overall average thickness of the blow molded container 5 is preferably 300 to 10,000 μm, more preferably 500 to 8,500 μm, and still more preferably 1,000 to 7,000 μm. In addition, these whole average thickness says the average thickness in the trunk | drum of the blow molding container 5. FIG. If the overall average thickness is too large, the weight increases. For example, when used for a fuel container such as an automobile, the fuel efficiency is adversely affected and the cost of the container also increases. On the other hand, if the overall average thickness is too small, the rigidity cannot be maintained, and there is a risk of being easily destroyed. Therefore, it is important to set a thickness corresponding to the capacity and application. FIG. 1 is a partial cross-sectional view of the peripheral wall of the blow molded container 5. Hereinafter, each layer will be described.

[(1) layer (first layer)]
(1) Layer 1 is a layer containing EVOH (I) as a main component, and contains 0.01 ppm or more and 100 ppm or less of saturated ketone (II). The blow molded container 5 includes the (1) layer 1 containing the specific amount of the saturated ketone (II), thereby suppressing the occurrence of defects such as gelled blisters and streaks due to melt molding, coloring, and odor. And excellent in appearance. Moreover, since the said (1) layer 1 contains the said specific amount of saturated ketone (II), since it is excellent also in the self purge property in the manufacturing process of the blow molding container 5, manufacturing cost can be reduced. The (1) layer 1 preferably further contains a conjugated polyene compound. Furthermore, the (1) layer 1 may contain a boron compound, acetic acid, a phosphorus compound, and other optional components as long as the effects of the present invention are not impaired. Here, the “main component” means the most abundant component on the mass basis. Further, “ppm” is a mass ratio of the corresponding component in each layer, and 1 ppm is 0.0001 mass%. “Content of boron compound” is the content as boric acid equivalent mass. The “acetate content” is the content as acetic acid equivalent mass. The “content of phosphorus compound” is the content as phosphorus element equivalent mass. Hereinafter, each component will be described in detail.

(EVOH (I))
EVOH (I) is an ethylene-vinyl alcohol copolymer obtained by saponifying a copolymer of ethylene and vinyl ester.

  Examples of the vinyl ester include vinyl acetate, vinyl propionate, vinyl pivalate and the like, and vinyl acetate is preferable. These vinyl esters may be used alone or in combination of two or more.

  The EVOH (I) may contain other structural units derived from monomer units other than ethylene and vinyl ester. Examples of such monomer units include vinyl silane compounds and other polymerizable compounds. As content of said other structural unit, 0.0002 mol% or more and 0.2 mol% or less are preferable with respect to all the structural units of EVOH (I).

  Examples of the vinylsilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxy-ethoxy) silane, and γ-methacryloxypropyltrimethoxysilane. Of these, vinyltrimethoxysilane and vinyltriethoxysilane are preferred.

  Examples of the other polymerizable compounds include unsaturated hydrocarbons such as propylene and butylene; unsaturated carboxylic acids such as (meth) acrylic acid; and vinylpyrrolidones such as N-vinylpyrrolidone.

  The ethylene content of the EVOH (I) is usually 20 mol% or more and 45 mol% or less, preferably 24 mol% or more and 45 mol% or less, more preferably 27 mol% or more and 42 mol% or less, and more preferably 27 mol% or more. 38 mol% or less is more preferable. When the ethylene content is less than 20 mol%, EVOH (I) tends to be gelled due to a decrease in thermal stability during melt extrusion, and may easily generate defects such as gelled blisters and streaks. . In particular, if the operation is performed for a long time under conditions of higher temperature or higher speed than general melt extrusion conditions, the possibility of gelation increases. On the other hand, when EVOH (I) has an ethylene content of more than 45 mol%, the gas barrier property is lowered, and there is a possibility that the advantageous properties possessed by EVOH (I) cannot be fully exhibited.

  The saponification degree of the structural unit derived from the vinyl ester of EVOH (I) is usually 85% or more, preferably 90% or more, more preferably 98% or more, and further preferably 99% or more. If the degree of saponification is less than 85%, the thermal stability may be insufficient.

  The content of EVOH (I) in the layer (1) is usually 95% by mass or more, preferably 98.0% by mass or more, more preferably 99.0% by mass, and 99.5% by mass or more. Further preferred. By setting the EVOH (I) content in the specific range, the blow molded product is excellent in gas barrier properties, oil resistance, and the like.

(Saturated ketone (II))
Saturated ketone (II) suppresses the occurrence of defects such as gelled blisters and streaks due to melt molding, coloring and odor, and improves self-purge properties. Here, the saturated ketone (II) refers to a ketone that does not contain an unsaturated bond in a portion other than the carbonyl group in the molecule. As long as the saturated ketone (II) does not contain an unsaturated bond in a portion other than the carbonyl group, it may be a linear ketone or a branched ketone, and a ketone having a ring structure in the molecule. It may be. The number of carbonyl groups in the molecule of the saturated ketone (II) may be 1 or 2 or more.

  Examples of the saturated ketone (II) include saturated aliphatic ketones and saturated cyclic ketones.

  Examples of saturated aliphatic ketones include acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 3-methyl-2-butanone, 2-hexanone, 3-hexanone, 4-methyl-2-pentanone, 2-methyl-3- Pentanone, 3,3-dimethyl-2-butanone, 2-heptanone, 3-heptanone, 4-heptanone, 4-methyl-2-hexanone, 5-methyl-2-hexanone, 2,4-dimethyl-3-pentanone, 2-octanone, 3-methyl-2-heptanone, 5-methyl-3-heptanone, 3-octanone, 6-methyl-2-heptanone, 2-nonanone, 5-nonanone, 2,6-dimethyl-4-heptanone, 2,2,4,4-tetramethyl-3-pentanone, 6-undecanone, 2-undecanone, 7-tridecanone, methylcyclo Pentyl ketone, and the like methylcyclohexyl ketone.

  Examples of saturated cyclic ketones include cyclobutanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclononanone, cyclodecanone, cycloundecanone, and cyclododecanone.

  As carbon number of saturated ketone (II), from a viewpoint of the water solubility improvement of saturated ketone (II), 3-50 are preferable, 3-15 are more preferable, and 3-8 are more preferable. As the saturated ketone (II), among the exemplified examples, saturated aliphatic ketones are preferable from the viewpoint of being able to further suppress the occurrence of defects such as gelled blisters and streaks due to melt molding, and being excellent in appearance. Acetone, methyl ethyl ketone 2-hexanone is more preferable, and acetone is more preferable.

  In the saturated ketone (II), part or all of the hydrogen atoms may be substituted with a substituent as long as the effects of the present invention are not impaired. Examples of the substituent include a halogen atom, a hydroxy group, an amino group, an amide group, and a cyano group.

  The lower limit of the content of the saturated ketone (II) in the layer (1) is 0.01 ppm, preferably 0.05 ppm, more preferably 0.1 ppm, further preferably 0.15 ppm, and 0.2 ppm. Particularly preferred. As an upper limit of content of saturated ketone (II), it is 100 ppm, 95 ppm is preferable, 50 ppm is more preferable, 30 ppm is further more preferable, 20 ppm is especially preferable. When the content of the saturated ketone (II) in the (1) layer 1 is less than the lower limit, the blow molded container 5 has an effect of containing the saturated ketone (II), for example, an effect of suppressing generation of defects and coloring. Can not get enough. On the other hand, when the content of the saturated ketone (II) exceeds the above upper limit, the saturated ketone (II) exhibits a crosslinking effect at the time of melt molding, and may induce the generation of gelled blisters, resulting in insufficient appearance. There is a fear. Here, the content of the saturated ketone (II) in the (1) layer 1 means (1) a resin composition containing EVOH (I) as a main component forming the layer 1 (hereinafter referred to as “EVOH-containing resin composition”). It is a value obtained by quantifying the saturated ketone (II) contained in the dried resin composition obtained by drying “.

(Conjugated polyene compound)
The conjugated polyene compound suppresses oxidative degradation during melt molding. Here, the conjugated polyene compound is a so-called conjugated double compound having a structure in which carbon-carbon double bonds and carbon-carbon single bonds are alternately connected and having two or more carbon-carbon double bonds. A compound having a bond. This conjugated polyene compound may be a conjugated diene having two conjugated double bonds, a conjugated triene having three, or a conjugated polyene having more than that number. Further, a plurality of sets of the conjugated double bonds may be present in one molecule without being conjugated with each other. For example, a compound having three conjugated triene structures in the same molecule such as tung oil is also included in the conjugated polyene compound.

  The number of conjugated double bonds that the conjugated polyene compound has is preferably 7 or less. When the (1) layer 1 contains a conjugated polyene compound having 8 or more conjugated double bonds, the blow molded container 5 may be colored.

  In addition to conjugated double bonds, the conjugated polyene compounds include carboxyl groups and salts thereof, hydroxyl groups, ester groups, carbonyl groups, ether groups, amino groups, imino groups, amide groups, cyano groups, diazo groups, nitro groups, sulfones. It may have other functional groups such as a group and a salt thereof, a sulfonyl group, a sulfoxide group, a sulfide group, a thiol group, a phosphate group and a salt thereof, a phenyl group, a halogen atom, a double bond, and a triple bond.

Examples of the conjugated polyene compound include isoprene, 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-t-butyl-1,3-butadiene, 1,3- Pentadiene, 2,3-dimethyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, 3,4-dimethyl-1,3-pentadiene, 3-ethyl-1,3-pentadiene, 2- Methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, 2,5-dimethyl-2,4- Hexadiene, 1,3-octadiene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, 1-phenyl-1,3-butadiene, 1,4-diphenyl-1,3-butyl Tadiene, 1-methoxy-1,3-butadiene, 2-methoxy-1,3-butadiene, 1-ethoxy-1,3-butadiene, 2-ethoxy-1,3-butadiene, 2-nitro-1,3-butadiene Butadiene, chloroprene, 1-chloro-1,3-butadiene, 1-bromo-1,3-butadiene, 2-bromo-1,3-butadiene, fulvene, tropone, ocimene, ferrandrene, myrcene, farnesene, sorbic acid, Conjugated dienes such as sorbic acid esters and sorbates;
Conjugated trienes such as 1,3,5-hexatriene, 2,4,6-octatriene-1-carboxylic acid, eleostearic acid, tung oil, cholecalciferol;
Examples thereof include conjugated polyenes such as cyclooctatetraene, 2,4,6,8-decatetraene-1-carboxylic acid, retinol, and retinoic acid. In addition, the said conjugated polyene compound may be used individually by 1 type, and may use 2 or more types together.

  Among these, sorbic acid, sorbic acid ester, sorbate, myrcene and a mixture of any of these are preferable, and sorbic acid, sorbate and a mixture thereof are more preferable. Sorbic acid, sorbate and a mixture thereof are highly effective in suppressing oxidative degradation at high temperatures, and are also widely used industrially as food additives, and thus are preferable from the viewpoint of hygiene and availability.

  The molecular weight of the conjugated polyene compound is usually 1,000 or less, preferably 500 or less, and more preferably 300 or less. When the molecular weight of the conjugated polyene compound exceeds 1,000, the dispersion state of the conjugated polyene compound in EVOH (I) may be deteriorated, and the appearance after melt molding may be deteriorated.

  The lower limit of the content of the conjugated polyene compound in the layer (1) is preferably 0.01 ppm, more preferably 0.5 ppm, and even more preferably 1 ppm. The upper limit of the content is preferably 1,000 ppm, more preferably 800 ppm, and even more preferably 500 ppm. In the blow-molded container 5, if the content of the conjugated polyene compound in the layer 1 is less than the lower limit, an effect of suppressing oxidative deterioration at the time of melt molding cannot be obtained sufficiently, and gel-like defects occur. There is a fear. On the other hand, when the content of the conjugated polyene compound exceeds the above upper limit, the occurrence of gelled fuzz is promoted, and the appearance of the blow molded container 5 may be deteriorated.

(Boron compound)
The boron compound suppresses gelation during melt molding and suppresses torque fluctuations (viscosity change during heating) of an extruder or the like. Moreover, since the (1) layer 1 further contains a boron compound, it is further excellent in the self-purge property at the time of manufacture, so that it can be manufactured at a lower cost.

Examples of the boron compound include boric acids such as orthoboric acid, metaboric acid, and tetraboric acid;
Borate esters such as triethyl borate and trimethyl borate;
Borate salts such as alkali metal salts or alkaline earth metal salts of borates, borax;
Examples thereof include borohydrides. Of these, boric acids are preferable, and orthoboric acid (hereinafter sometimes simply referred to as “boric acid”) is more preferable.

  As a minimum of content of the said boron compound in the said (1) layer 1, 100 ppm is preferable and 150 ppm is more preferable. The upper limit of the boron compound content is preferably 5,000 ppm, more preferably 4,000 ppm, and even more preferably 3,000 ppm. If the boron compound content is less than the above lower limit, torque fluctuations in an extruder or the like may not be sufficiently suppressed. On the other hand, if the content of the boron compound exceeds the above upper limit, gelation tends to occur during melt molding, and the appearance of the blow molded container 5 may be deteriorated.

(Acetic acid)
Acetic acid suppresses coloring of the blow molded container 5 and gelation during melt molding. The acetic acids include acetic acid and acetate. As acetic acid, it is preferable to use acetic acid and acetate together, and it is more preferable to use acetic acid and sodium acetate together.

  As a minimum of content of acetic acid in the above (1) layer 1, 100 ppm is preferred, 150 ppm is more preferred, and 200 ppm is still more preferred. The upper limit of the acetic acid content is preferably 1,000 ppm, more preferably 500 ppm, and still more preferably 400 ppm. If the acetic acid content is less than the above lower limit, a sufficient anti-coloring effect cannot be obtained, and yellowing may occur in the blow molded container 5. On the other hand, if the content of acetic acid exceeds the above upper limit, gelation tends to occur during melt molding, particularly during melt molding over a long time, and the appearance of the blow molded container 5 may be deteriorated.

(Phosphorus compound)
The phosphorus compound further suppresses the occurrence of defects such as gelled spots, coloring and odor, and improves the appearance of the molded product. Examples of the phosphorus compound include phosphates such as phosphoric acid and phosphorous acid.

  As said phosphate, any form of a 1st phosphate, a 2nd phosphate, and a 3rd phosphate may be sufficient. Moreover, although it does not specifically limit also about the cation seed | species of a phosphate, An alkali metal salt and alkaline-earth metal salt are preferable, Among these, sodium dihydrogen phosphate, potassium dihydrogen phosphate, hydrogen phosphate 2 Sodium and dipotassium hydrogen phosphate are more preferable, and sodium dihydrogen phosphate and dipotassium hydrogen phosphate are more preferable.

  As a minimum of content of a phosphorus compound in the above-mentioned (1) layer 1, 2 ppm is preferred, 3 ppm is more preferred, and 5 ppm is still more preferred. As an upper limit of content of a phosphorus compound, 200 ppm is preferable, 150 ppm is more preferable, and 100 ppm is further more preferable. When the content of the phosphorus compound is less than the above lower limit or exceeds the above upper limit, the thermal stability is reduced, and there is a risk that gelled spots and coloration are likely to occur during long-time melt molding. .

(Other optional ingredients)
The (1) layer 1 may contain other optional components as long as the effects of the present invention are not impaired. Other optional components include, for example, alkali metals or salts thereof, antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, heat stabilizers, other resins, and higher aliphatic carboxylic acids. And metal salts thereof. The said resin composition may contain 2 or more types of these arbitrary components, and as a total content of an arbitrary component, 1 mass% or less in the said (1) layer 1 is preferable.

  Examples of the alkali metal include lithium, sodium, and potassium. Examples of the alkali metal salts include monovalent metal aliphatic carboxylates, aromatic carboxylates, metal complexes, and the like. Specifically, sodium acetate, potassium acetate, sodium stearate, Examples include potassium stearate and sodium salt of ethylenediaminetetraacetic acid. Among these, sodium acetate and potassium acetate are preferable. The alkali metal content in the resin composition is preferably 20 ppm to 1,000 ppm, more preferably 50 ppm to 500 ppm.

  Examples of the antioxidant include 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4′-thiobis (6-t-butylphenol), 2,2 '-Methylene-bis (4-methyl-6-t-butylphenol), octadecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis (6 -T-butylphenol) and the like.

  Examples of the ultraviolet absorber include ethylene-2-cyano-3,3′-diphenyl acrylate, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-). Methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-oxybenzophenone and the like.

  Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate ester.

  Examples of the antistatic agent include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, polyethylene glycol (trade name: carbowax) and the like.

  Examples of the lubricant include ethylene bisstearamide and butyl stearate.

  Examples of the colorant include carbon black, phthalocyanine, quinacridone, indoline, azo pigments, and bengara.

  Examples of the filler include glass fiber, wollastonite, calcium silicate, talc, and montmorillonite.

  Examples of the heat stabilizer include hindered phenol compounds and hindered amine compounds.

  Examples of the other resin include polyamide and polyolefin.

  Examples of the higher aliphatic carboxylic acid metal salt include calcium stearate and magnesium stearate.

  In addition, as a countermeasure against gelation, for example, hindered phenol compounds and hindered amine compounds exemplified as the heat stabilizer, metal salts of the higher fatty acid carboxylic acids, hydrotalcite compounds, and the like may be added. These may be used alone or in combination of two or more. The addition amount of the compound for preventing gelation is usually 0.01% by mass to 1% by mass.

<Method for preparing EVOH-containing resin composition>
The (1) layer 1 can be formed of an EVOH-containing resin composition containing each component. As a method for producing this EVOH-containing resin composition, saturated ketone (II) can be uniformly blended in EVOH (I), and finally obtained (1) Layer 1 has a range of 0.01 ppm to 100 ppm. Although it will not specifically limit if it is a manufacturing method in which saturated ketone (II) is contained,
(1) a step of copolymerizing ethylene and vinyl ester (hereinafter also referred to as “step (1)”), and (2) a step of saponifying the copolymer obtained in step (1) (hereinafter referred to as “step (1)”). Also referred to as “Process (2)”)
A process for producing an ethylene-vinyl alcohol copolymer-containing resin composition having
A method for producing a resin composition, wherein 0.01 to 100 ppm of saturated ketone (II) is contained in the resin composition, is preferred.

The method for containing the specific amount of saturated ketone (II) in the resin composition is not particularly limited. For example, a method of adding the specific amount of saturated ketone (II) in the step (1),
A method of adding a specific amount of saturated ketone (II) in the step (2),
Examples include a method of adding a specific amount of saturated ketone (II) to EVOH obtained by the above step (2). However, the resin composition obtained when the method of adding a specific amount of saturated ketone (II) in the step (1) or the method of adding a specific amount of saturated ketone (II) in the step (2) is adopted. In order to contain a desired amount of saturated ketone (II) in the product, the amount added is increased in consideration of the amount consumed in the polymerization reaction in step (1) and the saponification reaction in step (2). It is necessary to inhibit these reactions. Further, since the amount consumed varies depending on the reaction conditions of the polymerization reaction and saponification reaction, it is difficult to adjust the content of the saturated ketone (II) in the resin composition. Therefore, a method of adding a specific amount of saturated ketone (II) to EVOH (I) obtained by the above step (2) after the above step (2) is preferable.

  As a method of adding a specific amount of saturated ketone (II) to the EVOH (I), for example, a method of granulating pellets by previously blending saturated ketone (II) with EVOH (I), ethylene-vinyl ester copolymer A method of impregnating a saturated ketone (II) into a strand precipitated in the step of depositing a paste after saponification of a coalescence, a method of impregnating a saturated ketone (II) after cutting the precipitated strand, and a chip of a dry resin composition A method of adding saturated ketone (II) to a redissolved product, a method of melt kneading a blend of two components of EVOH (I) and saturated ketone (II), and melting EVOH (I) from the middle of an extruder A method of supplying and containing saturated ketone (II) to a product, and a master batch in which saturated ketone (II) is blended with EVOH (I) at a high concentration and granulated. EVOH (I) and a method in which melt-kneading the dry blend can be mentioned.

  Among these, from the viewpoint that a small amount of saturated ketone (II) can be uniformly dispersed in EVOH (I), the saturated ketone (II) is previously mixed with EVOH (I) as the saturated ketone (II) mixing step. The step of blending in and granulating the pellet is preferred. Specifically, saturated ketone (II) is added by adding saturated ketone (II) to a solution in which EVOH (I) is dissolved in a good solvent such as a water / methanol mixed solvent, and then mixing the mixed solution with a nozzle or the like. It is preferably carried out by extruding into a poor solvent and precipitating and / or solidifying it, and washing and / or drying it. In this case, pellets in which saturated ketone (II) is uniformly mixed with EVOH (I) can be obtained.

  Examples of the method of adding each component other than the saturated ketone (II) in the layer (1) include, for example, a method of mixing and melting and kneading the pellet together with the components, and a saturated ketone ( II) and a method of mixing each component at the same time, a method of immersing the pellet in a solution containing each component, and the like. For the mixing, a ribbon blender, a high-speed mixer, a mixing roll, an extruder, an intensive mixer, or the like can be used.

  (1) The thickness ratio (I / O) when the total thickness of each layer inside the layer 1 is I and (1) the total thickness of each layer outside the layer 1 is O is 1 / 99-70 / 30 is preferable, 1 / 99-55 / 45 is more preferable, and 30 / 70-55 / 45 is further more preferable. In addition, the thickness of the whole layer or each layer of the blow-molded container 5 is obtained by observation with an optical microscope for a sample obtained by cutting a plurality of cross sections from the container body using a microtome, and an average value is obtained for all layers or each layer. Calculate and use the average thickness of all layers or the average thickness of each layer.

  (1) The average thickness of layer 1 is not particularly limited, but is preferably 5.0% or less of the average thickness of all layers, from the viewpoint of barrier properties and mechanical strength, and is 0.5% to 5%. Is more preferable, 1.0% to 4.5% is further preferable, and 1.5% to 4.0% is particularly preferable.

[(2) layer (second layer)]
The (2) layer 2 is a thermoplastic resin that is disposed on the inner surface side and the outer surface side of the (1) layer 1 and has a solubility parameter calculated from the Fedors equation of 11 (cal / cm ³ ) ^1/2 or less. It is a layer which has as a main component. A thermoplastic resin having a solubility parameter calculated by this formula of 11 (cal / cm ³ ) ^1/2 or less is excellent in moisture resistance. The solubility parameter calculated from the Fedors equation is a value represented by (E / V) ^1/2 . In the above formula, E is the molecular cohesive energy (cal / mol) and is represented by E = Σei. Note that ei is evaporation energy. Moreover, V is molecular volume (cm < ³ > / mol) and is represented by V = (SIGMA) vi (vi: molar volume).

The thermoplastic resin included in the layer (2) is not particularly limited as long as the solubility parameter is 11 (cal / cm ³ ) ^1/2 or less. For example, the solubility parameter is 11 (Cal / cm ³ ) ^1/2 or less polyethylene (linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, etc.), ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, Polypropylene, copolymer of propylene and α-olefin having 4 to 20 carbon atoms, homopolymer or copolymer of olefin such as polybutene and polypentene, polystyrene, polyvinyl chloride, polyvinylidene chloride, acrylic resin, vinyl ester Resin, polyurethane elastomer, polycarbonate, chlorinated polyethylene, salt Polypropylene, and the like. Among these, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polypropylene, and polystyrene are preferable, and high-density polyethylene is more preferable.

The density of the high-density polyethylene is preferably 0.93 g / cm ³ or more, preferably 0.95 g / cm ³ or more from the viewpoint of rigidity, impact resistance, moldability, drawdown resistance, gasoline resistance, and the like. 98 g / cm ³ or less is more preferable, and 0.96 g / cm ³ or more and 0.98 g / cm ³ or less is more preferable. Further, the melt flow rate (MFR) of the high-density polyethylene is preferably in the range of 0.01 g / 10 min to 0.5 g / 10 min under a load of 2160 g at 190 ° C., and 0.01 g / 10 min to 0.1 g. A range of / 10 minutes is more preferable.

  The high-density polyethylene can be appropriately selected from commercially available products. Moreover, the (2) layer 2 may contain other optional components similar to those of the (1) layer 1 as long as the effects of the present invention are not impaired.

  (2) The average thickness of the layer 2 is not particularly limited, but is preferably 5% to 70%, more preferably 8% to 60%, and even more preferably 10% to 50% of the average thickness of all layers. .

[(3) layer (third layer)]
The (3) layer 3 is a layer which is disposed between the (1) layer 1 and the (2) layer 2 and has carboxylic acid-modified polyolefin as a main component. The (3) layer 3 can function as an adhesive layer between (1) the layer 1 and other layers such as the (2) layer 2. The carboxylic acid-modified polyolefin has a carboxyl group or an anhydride group obtained by chemically bonding an ethylenically unsaturated carboxylic acid or an anhydride thereof to an olefin polymer by an addition reaction, a graft reaction or the like. It refers to an olefin polymer.

  Examples of the ethylenically unsaturated carboxylic acid or anhydride thereof include monocarboxylic acid, monocarboxylic acid ester, dicarboxylic acid, dicarboxylic acid monoester, dicarboxylic acid diester, and dicarboxylic acid anhydride. Specific examples include maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, and fumaric acid monomethyl ester. Of these, dicarboxylic anhydrides such as maleic anhydride and itaconic anhydride are preferred, and maleic anhydride is more preferred.

Examples of the olefin polymer to be a base polymer include polyolefins such as low density, medium density or high density polyethylene, linear low density polyethylene, polypropylene, boribten;
Examples thereof include a copolymer of an olefin such as an ethylene-vinyl acetate copolymer and an ethylene-ethyl acrylate copolymer and a comonomer such as a vinyl ester and an unsaturated carboxylic acid ester that can be copolymerized with these olefins. Among these, linear low density polyethylene, ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 to 55% by mass, and ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 8 to 35% by mass. A coalescence is preferred, and a linear low density polyethylene and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5 to 55% by mass are more preferred.

  The carboxylic acid-modified polyolefin is prepared by adding the ethylenically unsaturated carboxylic acid or its anhydride to the olefin polymer in the presence of a solvent such as xylene or a catalyst such as peroxide by an addition reaction or a graft reaction. It is obtained by introducing. At this time, the addition amount or graft amount (degree of modification) of the carboxylic acid or its anhydride to the olefin polymer is preferably 0.01 to 15% by mass with respect to the olefin polymer, and 0.02 to 10%. The mass% is more preferable.

  The carboxylic acid-modified polyolefin may be used alone or in combination of two or more.

  The (3) layer 3 may contain other optional components similar to the (1) layer 1 in addition to the carboxylic acid-modified polyolefin as long as the effects of the present invention are not impaired.

  (3) The average thickness of the layer 3 is not particularly limited, but is preferably 0.3% to 12%, more preferably 0.6% to 9%, and 1.2% of the average thickness of all layers. -6% is more preferable. If the thickness of the (3) layer 3 as the adhesive resin layer is too small, the adhesiveness is lowered, and if too large, the cost increases, which is not preferable.

[(4) layer (fourth layer)]
The (4) layer 4 is a layer containing the ethylene-vinyl alcohol copolymer (I), the thermoplastic resin, and the carboxylic acid-modified polyolefin. In addition, the (4) layer 4 is preferably formed using the recovered material of the (1) layer 1, (2) layer 2 and (3) layer 3 in the manufacturing process of the blow molded container 5. Examples of the recovered material include burrs generated in the manufacturing process of the blow-molded container 5, unacceptable products. Since the blow molded container 5 further includes the (4) layer 4 as such a recovery layer, the resin used at the time of manufacturing the blow molded container 5 by reusing such burrs and rejected products. Loss can be reduced.

  (4) The layer 4 can be used in place of the above-mentioned (2) layer 2, but in general, the mechanical strength of the (4) layer 4 may be lower than that of the (2) layer 2. Since there are many, it is preferable to laminate | stack (2) layer 2 and (4) layer 4, and to use. When the blow molded container 5 receives an impact from the outside, stress concentration occurs in the container, and the compressive stress against the impact acts on the inner layer side of the container in the stress concentration portion, so that damage may occur. It is preferable that the (4) layer 4 which is weak to the (1) layer 1 is arranged on the outer layer side than the layer 1. Moreover, when it is necessary to recycle a large amount of resin, such as when burrs are frequently generated, a recovery layer can be disposed as (4) layer 4 on both sides of (1) layer 1.

  (4) The EVOH (I) content in the layer 4 is preferably 9.0% by mass or less. When the content of EVOH (I) in the (4) layer 4 exceeds 9% by mass, cracks are likely to occur at the interface with the (2) layer 2, and the entire blow-molded container 5 is destroyed starting from the crack. May happen.

  (4) The average thickness of the layer 4 is not particularly limited, but is preferably 10% to 60%, more preferably 20% to 55%, and even more preferably 30% to 50% of the total average thickness of all layers. .

<Method for producing blow molded container 5>
The blow-molded container 5 has a step of blow-molding using a resin composition containing ethylene-vinyl alcohol copolymer (I) as a main component, and the resin composition contains saturated ketone (II). It is preferable to manufacture by the manufacturing method whose content in the said resin composition of saturated ketone (II) is 0.01 ppm or more and 100 ppm or less. Specifically, (1) dry EVOH-containing resin composition pellets forming layer 1, (2) high-density polyethylene resin forming layer 2, (3) adhesive resin forming layer 3, and (4 ) Using the recovered resin that forms layer 4, etc., at a temperature of 100 ° C. to 400 ° C. with a blow molding machine, for example, (inner) 2/3/1/3/4/2 (outer) 4 types 6-layer parison Can be blow-molded and cooled at a mold internal temperature of 10 ° C. to 30 ° C. for 10 seconds to 30 minutes to form a hollow container having an average thickness of all layers of 300 μm to 10,000 μm.

<Other embodiments>
The blow-molded container of the present invention is not limited to the form of FIG. 1 described above, and may be provided with at least (1) layer. Specifically, the (4) layer or the like as the recovery layer may not be provided. Furthermore, other layers may be laminated. Moreover, you may abbreviate | omit the (3) layer as an adhesive layer by selecting the combination of resin with good adhesiveness.

  When (2) a layer is provided, it is preferable to arrange the (2) layer in the outermost layer. That is, from the inner surface of the container toward the outer surface of the container, the arrangement is (2) layer / (3) layer / (1) layer / (3) layer / (2) layer (hereinafter (inner) 2 / 3/1/3/2 (outside) is preferable from the viewpoint of impact resistance. When (4) layers such as a collection layer are included, (inner) 2/3/1/3/4/2 (outer), (inner) 2/4/3/1/3/4/2 (Outside), (Inside) 4/3/1/3/4 (Outside) arrangement is preferable (Inside) 2/3/1/3/4/2 (Outside), (Inside) 2/4/3 The arrangement of 1/3/4/2 (outside) is more preferable. In addition, the structure provided with (4) layer instead of (2) layer may be sufficient, and when it is the arrangement | positioning by which multiple (1)-(4) layers are each used, resin which comprises each layer is the same or different. May be.

<Fuel container>
The blow molded container of the present invention can be used as a fuel container. The fuel container may include a filter, a fuel gauge, a baffle plate, and the like. Since the fuel container is provided with the above-described blow molded container, the fuel container is excellent in appearance, gas barrier property, oil resistance, and the like, and thus is suitably used as a fuel container. Here, the fuel container is a fuel container mounted on an automobile, a motorcycle, a ship, an aircraft, a generator, an industrial or agricultural device, or a portable fuel container for supplying fuel to these fuel containers. Means a container for storing fuel. Examples of the fuel include gasoline, particularly oxygen-containing gasoline blended with methanol, ethanol, MTBE, or the like, but also includes heavy oil, light oil, kerosene, and the like. Among these, the fuel container is particularly preferably used as a fuel container for oxygen-containing gasoline.

<Bottle>
The blow molded container of the present invention can be used as a bottle. Examples of the molding method include direct blow molding and injection blow molding. A blow molded container formed into a bottle shape is excellent in appearance, gas barrier properties, oil resistance, and the like, and thus is suitably used for bottle containers for foods, cosmetics and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples.

<Synthesis of EVOH (I)>
[Synthesis Example 1]
Polymerization of the ethylene-vinyl acetate copolymer was carried out under the following conditions using a 250 L pressurized reactor.
83.0 kg of vinyl acetate,
26.6 kg of methanol,
Feed rate of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (2.5 g / L methanol solution) 1119.5 mL / hr
Polymerization temperature 60 ° C
Polymerization tank ethylene pressure 3.6 MPa
Polymerization time 5.0 hours The polymerization rate of vinyl acetate in the obtained copolymer was about 40%. After adding sorbic acid to this copolymerization reaction solution, the sorbic acid is supplied to the extraction tower, and unreacted vinyl acetate is removed from the top of the tower by introducing methanol vapor from the bottom of the tower. % Methanol solution was obtained. The ethylene content of this ethylene-vinyl acetate copolymer was 32 mol%. This methanol solution of ethylene-vinyl acetate copolymer is charged into a saponification reactor, and caustic soda / methanol solution (80 g / L) is added so as to be 0.4 equivalent to the vinyl ester component in the copolymer. Then, methanol was added to adjust the copolymer concentration to 20%. This solution was heated to 60 ° C. and reacted for about 4 hours while blowing nitrogen gas into the reactor. This solution was extruded into water from a metal plate having a circular opening, precipitated, and cut to obtain pellets having a diameter of about 3 mm and a length of about 5 mm. The obtained pellet was drained with a centrifuge, and the operation of adding a large amount of water and draining was repeated.

<Preparation of EVOH-containing resin composition>
20 kg of the lysed pellets were put into 180 kg of a mixed solvent of water / methanol = 40/60 (mass ratio) and stirred at 60 ° C. for 6 hours to completely dissolve the pellets. Saturated ketone (II) and a conjugated polyene compound were added to the resulting solution, and the mixture was further stirred for 1 hour to completely dissolve the saturated ketone (II) and the conjugated polyene compound, thereby obtaining a resin composition solution. This resin composition solution was continuously extruded from a nozzle having a diameter of 4 mm into a coagulation bath of water / methanol = 90/10 (mass ratio) adjusted to 0 ° C. to be solidified into a strand. This strand was introduced into a pelletizer to obtain a porous resin composition chip. The obtained porous resin composition chip was washed with an acetic acid aqueous solution and ion-exchanged water. The cleaning liquid and the resin composition chip are separated and drained, and then placed in a hot air dryer, dried at 80 ° C. for 4 hours, and further dried at 100 ° C. for 16 hours to obtain a resin composition (dried resin composition). Pellets). The content of each component in the obtained resin composition was quantified by the above quantification method, and the content in the (1) layer was determined. Each resin composition so that the content of the saturated ketone (II) and the conjugated polyene compound is as shown in Table 1 by adjusting the addition amount of the saturated ketone (II) and the concentration of each component of the aqueous solution for immersion treatment. A product was prepared.

[Synthesis Example 2 and Preparation of EVOH-containing Resin Composition]
The same operation as in Synthesis Example 1 was performed to obtain pellets. 20 kg of the obtained pellets and saturated ketone (II) were put into 180 kg of a mixed solvent of water / methanol = 40/60 (mass ratio) and stirred at 60 ° C. for 6 hours to completely dissolve the pellets. To the obtained solution, sorbic acid as a conjugated polyene compound was added and further stirred for 1 hour to completely dissolve sorbic acid to obtain a resin composition solution. This resin composition solution was continuously extruded from a nozzle having a diameter of 4 mm into a coagulation bath of water / methanol = 90/10 (mass ratio) adjusted to 0 ° C. to be solidified into a strand. This strand was introduced into a pelletizer to obtain a porous resin composition chip. The obtained porous resin composition chip was washed with an aqueous acetic acid solution and ion-exchanged water, and then immersed in an aqueous solution containing acetic acid, sodium acetate, potassium dihydrogen phosphate and boric acid. The aqueous solution for immersion treatment and the resin composition chip are separated and drained, and then placed in a hot air dryer, dried at 80 ° C. for 4 hours, and further dried at 100 ° C. for 16 hours to obtain a resin composition (dried Resin composition pellets) were obtained. The content of each component in the obtained resin composition was quantified using the above quantification method. In addition, the resin composition was prepared so that content of each component might become as as described in Table 1 by adjusting the density | concentration of each component of the aqueous solution for immersion treatment.

<Evaluation of EVOH-containing resin composition>
Each EVOH-containing resin composition thus obtained was evaluated as follows. The evaluation results are shown in Table 1. Moreover, each fixed_quantity | quantitative_assay in a present Example was performed using the following method.

(1) Measurement of water content of water-containing EVOH pellets Water content of water-containing EVOH pellets using a halogen moisture analyzer “HR73” manufactured by METTLER TOLEDO at a drying temperature of 180 ° C., a drying time of 20 minutes, and a sample amount of about 10 g. The rate was measured. The moisture content of the water-containing EVOH shown below is mass% based on the dry mass of EVOH.

(2) Ethylene content of EVOH (A) and degree of saponification: Determined by ¹ H-NMR (“JNM-GX-500 type” manufactured by JEOL Ltd.) using DMSO-d ₆ as a solvent.

(3) Quantification of carboxylic acid and carboxylate ion The dried EVOH pellets were pulverized by freeze pulverization. The obtained pulverized EVOH was divided by a sieve having a nominal size of 1 mm (conforming to standard fluid standard JIS Z8801-3). 10 g of EVOH powder and 50 mL of ion exchanged water that passed through the sieve were put into a 100 mL Erlenmeyer flask with a stopper, and a cooling condenser was attached, followed by stirring at 95 ° C. for 10 hours. 2 mL of the obtained solution was diluted with 8 mL of ion exchange water. The amount of the carboxylic acid and the carboxylate ion was calculated by quantifying the amount of the carboxylate ion of this diluted solution according to the following measurement conditions using ion chromatography “ICS-1500” manufactured by Yokogawa Electric Corporation. A calibration curve prepared using monocarboxylic acid or polyvalent carboxylic acid was used for quantification.

(Measurement condition)
Column: “IonPAC ICE-AS1 (9φ × 250 mm, electrical conductivity detector)” from DIONEX

Eluent: 1.0 mmol / L Octanesulfonic acid aqueous solution Measurement temperature: 35 ° C
Eluent flow rate: 1 mL / min.
Analytical volume: 50 μL

(4) Determination of metal ions 0.5 g of dry EVOH pellets were charged into a Teflon (registered trademark) pressure vessel made by Actac, and 5 mL of nitric acid for precision analysis from Wako Pure Chemical Industries, Ltd. was further added. After standing for 30 minutes, the container is covered with a cap lip with a rupture disk, treated at 150 ° C for 10 minutes and then at 180 ° C for 10 minutes with Actac's microwave high-speed decomposition system "Speedwave MWS-2", and dried EVOH The pellet was broken down. When the decomposition of the dry EVOH pellets was not completed, the processing conditions were adjusted as appropriate. The obtained decomposition product was diluted with 10 mL of ion exchange water, and all the liquids were transferred to a 50 mL volumetric flask and the volume was adjusted with ion exchange water to obtain a decomposition product solution.

  By using the ICP emission spectroscopic analyzer “Optima 4300 DV” of PerkinElmer Japan, the obtained decomposition product solution is quantitatively analyzed at each of the following observation wavelengths, so that metal ions, phosphate compounds and boron compounds can be obtained. The amount was quantified. The amount of the phosphoric acid compound was calculated as phosphorus element equivalent mass by quantifying phosphorus element. The boron compound content was calculated as boric acid equivalent mass.

Na: 589.592 nm
K: 766.490 nm
Mg: 285.213 nm
Ca: 317.933 nm
P: 214.914 nm
B: 249.667 nm
Si: 251.611 nm
Al: 396.153 nm
Zr: 343.823 nm
Ce: 413.764 nm
W: 207.912 nm
Mo: 202.031 nm

(5) Quantification of saturated ketone (II) 50 mg of 2,4-dinitrophenylhydrazine (DNPH) solution 200 mg, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) 50 mL, acetic acid 11 5 mL and 8 mL of ion exchange water were added to prepare a DNPH adjustment solution. Thereafter, 1 g of dry EVOH-containing resin composition pellets was added to 20 mL of the DNPH adjustment solution, and stirred and dissolved at 35 ° C. for 1 hour. Acetonitrile was added to this solution to precipitate and precipitate EVOH, and then the solution obtained by filtration was concentrated to obtain an extracted sample. Saturated ketone (II) was quantified by quantitatively analyzing the extracted sample by high performance liquid chromatography under the following conditions. In quantification, a calibration curve prepared by reacting each sample of saturated ketone (II) with a DNPH solution was used. The lower limit of detection of saturated ketone (II) was 0.01 ppm. In addition, in this application, content in the dry resin composition used in order to form the layer was used as content of each component in each layer in a blow molded container.

(Analysis conditions)
Column: TSKgel ODS-80Ts (Tosoh Corporation)
Mobile phase: water / acetonitrile = 52: 48 (volume ratio)
Detector: PDA (360 nm), TOF-MS

(6) Quantification of Conjugated Polyene Compound The dried resin composition pellets were pulverized by freeze pulverization and obtained by removing coarse particles with a sieve having a nominal size of 0.150 mm (100 mesh) (conforming to JIS standard Z8801-3). 10 g of the pulverized product was filled in a Soxhlet extractor and extracted with 100 mL of chloroform for 48 hours. The amount of the conjugated polyene compound was quantitatively analyzed by high performance liquid chromatography to quantify the amount of the conjugated polyene compound. For quantification, a calibration curve prepared using a sample of each conjugated polyene compound was used.

(7) Solution appearance (transparency, coloring)
10 g of pellets obtained by heat-treating the dried resin composition pellets at 120 ° C. for 15 hours in air are placed in a 300 ml Erlenmeyer flask, 100 ml of a water / propanol mixed solution (mass ratio: water / propanol = 45/55) is added, and 3 ° C. is added at 75 ° C. Stir for hours. About the solution heated and stirred for 3 hours, the transparency and coloring of the solution were visually evaluated according to the following evaluation criteria.

(Transparency evaluation criteria)
“Good (A)”: Transparent, no visible suspended matter.
“Slightly good (B)”: Slightly cloudy, with floating matter that can be visually confirmed.
“Bad (C)”: cloudy and floating.

(Solution coloring criteria)
“Good (A)”: Colorless “Slightly good (B)”: Slightly colored “Poor (C)”: Remarkably colored

(8) Motor torque fluctuation 60 g of dry resin composition pellets were kneaded at 100 rpm and 260 ° C. at Laboplast Mill (Toyo Seiki Seisakusho “20R200” biaxial different direction), and the torque value after 5 minutes from the start of kneading was 1.5. The time required for doubling was measured and evaluated according to the following evaluation criteria.
“Good (A)”: 60 minutes or more “Slightly good (B)”: 40 minutes or more and less than 60 minutes “Poor (C)”: less than 40 minutes

(9) Odor during molding 20 g of resin composition pellets were placed in a 100 mL glass sample tube, the mouth was covered with aluminum foil, and then heated at 220 ° C. for 30 minutes in a hot air dryer. After removing from the dryer and allowing to cool at room temperature for 30 minutes, the sample tube was shaken 2-3 times, the aluminum foil lid was removed, and the odor was evaluated. The odor intensity of the sample pellets was evaluated according to the following evaluation criteria.
A: Do not feel odor B: Feel weak odor C: Clearly feel odor

<Preparation of recovered resin>
4 parts by mass of the above dry EVOH resin pellets, high density polyethylene resin (Mitsui Petrochemical HZ8200B, MFR at 190 ° C.-2160 g load = 0.01 g / 10 min), 86 parts by mass, and adhesive resin (Mitsui Chemicals ADMER GT- 6A, MFR = 0.94 g / 10 min at 190 ° C.-2160 g) After dry blending, a twin-screw extruder (“2D25W”, manufactured by Toyo Seiki Seisakusho; 25 mmφ, die temperature 220 ° C., screw rotation speed) 100 rpm) and extrusion pelletization was performed under a nitrogen atmosphere. Furthermore, in order to obtain a model recovered resin, this extruded pellet was further extruded and pelletized under the same extruder and under the same conditions, and the same operation was performed 4 times (total of 5 blends in the extruder) to obtain a recovered resin. .

<Manufacture of blow molded containers>
[Examples 1-14, Comparative Examples 1-3]
Using the dry EVOH resin pellets, the high-density polyethylene resin, the adhesive resin, and the recovered resin, at 210 ° C. on the blow molding machine TB-ST-6P manufactured by Suzuki Wood Works (inside) high-density polyethylene / Adhesive resin / EVOH / adhesive resin / recovered resin / resin composition (outside) 4 types and 6 layers parison were discharged for 2 hours, and the operation was stopped for 2 hours while being heated. Thereafter, the operation was resumed, and blow molded containers produced after each predetermined time were evaluated. In the production of blow molded containers, cooling is performed at a mold internal temperature of 15 ° C. for 20 seconds, and the total layer thickness is 1,000 μm ((inner side) high-density polyethylene / adhesive resin / EVOH / adhesive resin / recovered resin / resin. A 3 L tank of composition (outside) = (inside) 340/50/40/50/400/120 μm (outside)) was molded. The tank had a bottom diameter of 100 mm and a height of 400 mm. In addition, the dry EVOH resin pellets of Examples 1 to 11, 13, 14, and Comparative Examples 1 and 2 were obtained by Synthesis Example 1. Moreover, the dry EVOH resin pellet of Example 12 was obtained by Synthesis Example 2. The dry EVOH resin pellets of Comparative Example 3 were obtained according to Synthesis Example 1, but no saturated ketone (II) was added in the preparation of the EVOH-containing resin composition.

<Evaluation of blow molded container>
Each blow molded container thus obtained was evaluated as follows. The evaluation results are shown in Table 1.

(10) Evaluation of blow molded container [Evaluation of appearance]
About the 3L tank shape | molded 40 minutes after restarting, streak and coloring were visually evaluated on the following reference | standard, and it was set as evaluation of the external appearance.

(Evaluation criteria for streak)
“Good (A)”: no streak was observed.
“Slightly good (B)”: Streaks were confirmed.
“Bad (C)”: Many streaks were confirmed.

(Evaluation criteria for coloring)
“Good (A)”: Colorless “Slightly good (B)”: Yellowing “Poor (C)”: Extremely yellowing

[Impact resistance evaluation]
After 20 minutes, 40 minutes, and 10 hours after restarting, 2.5 L of propylene glycol is filled into a 3 L tank blow molded, and the opening is heat sealed with a film of polyethylene 40 μm / aluminum foil 12 μm / polyethylene terephthalate 12 μm. And covered it. The tank was cooled at −40 ° C. for 3 days, dropped from a height of 6 m so that the opening was on top, and evaluated by the number of broken pieces (n = 10). The impact resistance after 20 minutes of restarting is an index of self-purge properties.

(Evaluation criteria for impact resistance)
“Good (A)”: less than 3 “Slightly good (B)”: 3 to less than 6 “Poor (C)”: 6 or more

  As shown in Table 1, it was found that the blow-molded container of the present invention was excellent in appearance and the like, with streak generation, coloring and odor suppressed. In addition, the blow molded container of the present invention was excellent in impact resistance even if it was molded 20 minutes after restarting the molding apparatus. Since the blow molded container of the present invention uses an EVOH-containing resin composition having excellent self-purge properties, the occurrence of gel-like blisters that reduce impact resistance may not occur in a short time after restarting. all right. Furthermore, Examples 2, 7, 9, 10 and 12 that specify the type and content of saturated ketone (II) and the type and content of conjugated polyene compound are more suppressed in the occurrence of streak, coloring and odor, It was found to be superior in appearance and impact resistance.

  On the other hand, when the type and content of the saturated ketone (II) do not satisfy the prescribed requirements (Comparative Examples 1 to 3), it can be seen that streak generation, coloring and odor suppression, impact resistance, and the like are reduced. .

  In addition to having sufficient gas barrier properties and oil resistance as the characteristics of EVOH, the blow-molded container of the present invention includes a (1) layer containing a specific amount of saturated ketone (II), and thus is melt-molded. Since the occurrence of defects such as gelled blisters and streaks, coloring and odor are suppressed, the appearance is excellent. Moreover, since the layer (1) contains the specific amount of saturated ketone (II), the blow-molded container can be manufactured at low cost because the self-purge property in the process of manufacturing the blow-molded container is excellent. . Therefore, the blow molded container is used for various applications, and is particularly suitable as a fuel container.

1 (1) Ethylene-vinyl alcohol copolymer layer 2 (2) Thermoplastic resin layer 3 (3) Carboxylic acid modified polyolefin layer 4 (4) Ethylene-vinyl alcohol copolymer, thermoplastic resin, carboxylic acid modified polyolefin Containing layer 5 Blow molded container 6 Container inner surface 7 Container outer surface

Claims (12)

A blow molded container comprising a first layer mainly composed of ethylene-vinyl alcohol copolymer (I),
The first layer contains saturated ketone (II);
The blow molded container, wherein the content of the saturated ketone (II) in the first layer is 0.01 ppm or more and 100 ppm or less.   The blow molded container according to claim 1, wherein the saturated ketone (II) has 3 to 8 carbon atoms.   The blow molded container according to claim 2, wherein the saturated ketone (II) is at least one selected from the group consisting of acetone, methyl ethyl ketone and 2-hexanone.   The blow according to claim 1, 2 or 3, wherein the first layer contains a conjugated polyene compound, and the content of the conjugated polyene compound in the first layer is 0.01 ppm or more and 1,000 ppm or less. Molded container.   The blow-molded container according to claim 4, wherein the conjugated polyene compound is at least one of sorbic acid and sorbate. A pair of second layers mainly composed of a thermoplastic resin which is disposed on the inner surface side and the outer surface side of the first layer and whose solubility parameter calculated from the Fedors equation is 11 (cal / cm ³ ) ^1/2 or less. The blow molding of any one of Claims 1-5 provided with a pair of 3rd layer which is arrange | positioned between the said 1st layer and the said 2nd layer, and has carboxylic acid modified polyolefin as a main component. container.   The blow molded container according to claim 6, further comprising a fourth layer containing the ethylene-vinyl alcohol copolymer (I), the thermoplastic resin, and the carboxylic acid-modified polyolefin.   The blow molded container according to claim 7, wherein the fourth layer is formed by using the recovered material of the first layer, the second layer, and the third layer in the manufacturing process of the blow molded container. The average thickness of the first layer is 5.0% or less of the average thickness of all layers, and the content of the ethylene-vinyl alcohol copolymer in the fourth layer is 9.0% by mass or less. The blow molded container according to claim 8.   The blow molded container according to any one of claims 1 to 9, which is a fuel container.   The blow molded container according to any one of claims 1 to 9, wherein the blow molded container is a bottle. Having a step of blow molding using a resin composition containing ethylene-vinyl alcohol copolymer (I) as a main component,
The resin composition contains a saturated ketone (II),
The method for producing a blow molded container according to any one of claims 1 to 9, wherein a content of the saturated ketone (II) in the resin composition is 0.01 ppm or more and 100 ppm or less.

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