JP5095664B2 - Resin composition and multilayer structure using the same - Google Patents

Description

  The present invention provides a film surface abnormality caused by poor dispersion of EVOH when a resin composition comprising a polyolefin and a saponified ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVOH) is melt-molded. More specifically, the present invention relates to a resin composition in which generation of EVOH agglomerates in a microscopic region and generation of a wave pattern on the surface of a molded article are improved, and a multilayer structure including a layer formed of the resin composition.

  A resin composition obtained by blending polyolefin and EVOH is known (see Patent Document 1). However, this resin composition generally has poor compatibility, and when a film, a sheet, a bottle, or the like is formed by extrusion molding, it is not uniform. It is known that a phase-separated foreign matter is likely to be generated, and this foreign matter increases particularly when operated for a long time, and the appearance of the molded product is remarkably impaired (decrease in long-run moldability). It is also known that so-called “eyes” that are generated around the die outlet during extrusion of the resin composition are likely to cause problems such as mixing into the molded product and leading to quality degradation.

In order to improve such a poor compatibility between polyolefin and EVOH, it is effective to add a higher fatty acid metal salt having 8 to 22 carbon atoms, an ethylenediaminetetraacetic acid metal salt and / or a hydrotalcite compound. Is known (see Patent Document 1 and Patent Document 2). In addition to these combinations, in addition to polyolefin and EVOH, hydrotalcite compounds, higher fatty acids having 8 or more carbon atoms, boron compounds, phosphoric acid and / or alkali (earth) metal hydrogen phosphate -By blending a lower fatty acid metal salt with 7 or less carbon atoms, etc., long run property and heat resistance during melt molding of a composition mainly composed of polyolefin and EVOH (retaining physical properties against repeated thermal history during regrinding) Is disclosed (see Patent Document 3, Patent Document 4, and Patent Document 5). However, in these documents, the evaluation regarding the fish eye occurrence state at the time of film forming is conducted by examining the number of fish having a diameter of 0.2 mm or more per 100 cm ² .

  On the other hand, when a resin composition comprising polyolefin and EVOH is melt-molded, polyolefin and EVOH are used as polyolefin and EVOH as a resin composition that improves the generation of a wave pattern on the surface of the molded product, which is caused by flow abnormality due to poor compatibility. In addition to the above-mentioned higher fatty acid metal salt having 8 to 22 carbon atoms, ethylenediaminetetraacetic acid metal salt and hydrotalcite, ethylene content is 68 to 98 mol%, vinyl acetate unit saponification degree is 20 % Of ethylene-vinyl acetate copolymer saponified product (hereinafter sometimes referred to as S-EVOH) improves the compatibility of the resulting resin composition and the surface wave pattern of the molded product It is disclosed that the scrap composition such as regrind is effectively reused (see Patent Document 6).

Furthermore, by adding an acid graft-modified polyolefin-based resin and a polyhydric alcohol compound to the collected product of the laminate including the thermoplastic resin layer and the EVOH layer, the resulting resin composition has no gelation during melt molding. In addition, it is disclosed that the generation of wave patterns and fish eyes in a molded product is prevented, the long-run moldability is excellent, and the effect of preventing generation of phase-separated foreign matters (eyes) is effective (see Patent Document 7). However, in this document, the fish-eye evaluation is performed by examining the number of layers having a diameter per 100 cm ² of 0.4 mm or more in the regrind layer of the laminate.

  On the other hand, a method for producing a vinyl acetate polymer in which a conjugated polyene compound having a boiling point of 20 ° C. or higher is added to an ethylene-vinyl acetate copolymer, and a vinyl acetate polymer to saponify the vinyl acetate polymer obtained by such a method. A method for producing a combined saponified product is disclosed, and EVOH obtained by this method is said to be high in quality with little coloration and less gelled formation during molding (see Patent Document 8).

By the techniques disclosed in Patent Documents 2 to 7, the compatibility of EVOH and polyolefin in the resin composition obtained by blending polyolefin and EVOH is considerably improved, and the appearance of the molded product can be improved. However, in recent trends in environmental measures (reducing packaging materials and reducing waste), the trend toward thinner layers for cups, bottles, films, etc. has become stronger. In thick packaging materials, at a level that was not a problem due to the effect of transparency, occurrence of poor appearance due to poor dispersibility and abnormal flow in a finer region in a resin composition blended with polyolefin and EVOH There is still a need for improvement in terms of suppression.
Further, Patent Document 8 discloses a technique related to reducing gelled defects in a molded product of EVOH alone, and there is no teaching or suggestion about a resin composition blended with EVOH and polyolefin.

JP 60-199040 A JP-A-6-87195 JP-A-10-001569 JP-A-10-001570 Japanese Patent Application Laid-Open No. 09-278952 Japanese Patent Laid-Open No. 03-72542 JP 2008-115367 A JP 09-71620 A

The inventor of the present invention has a film surface abnormality that is caused when a resin composition obtained by blending a polyolefin and EVOH is melt-molded, and is caused by poor dispersion of EVOH. It was found that this is caused by the formation of EVOH aggregates in the microscopic region.
Accordingly, an object of the present invention is to improve the dispersion of EVOH by suppressing the formation of aggregates in such a microscopic region, and to generate a wave pattern on the surface of the molded product due to a flow abnormality caused by the aggregates. It is to suppress the appearance defect and thereby effectively reuse a scrap portion such as a laminate having a polyolefin layer and an EVOH layer as a regrind layer to obtain a molded article having a beautiful appearance.

  According to the present invention, the object is to saponify the ethylene-vinyl acetate copolymer (B) (polyolefin (A), ethylene content 20 to 65 mol%, vinyl acetate unit saponification degree 96% or more). Hereinafter, simply referred to as EVOH (B)), higher fatty acid metal salt (C) having 8 to 22 carbon atoms (hereinafter simply referred to as higher fatty acid metal salt (C)), conjugated polyene compound (D) having a boiling point of 20 ° C. or higher (Hereinafter simply referred to as conjugated polyene compound (D)), and ethylene-vinyl acetate copolymer (E) in which at least a part of vinyl acetate units is saponified (hereinafter referred to as partially saponified EVA (E)) And the mass ratio of the polyolefin (A) to the EVOH (B) is 60:40 to 99.9: 0.1, and the higher fatty acid metal salt (C) is converted to the polyolefin (A). in front In a range of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the total amount of EVOH (B), the conjugated polyene compound (D) is added to 100 parts by mass of the total amount of the polyolefin (A) and the EVOH (B). In contrast, in the range of 0.000001 to 1 part by mass, the partially saponified EVA (E) is contained in an amount of 0.3 part by mass or more with respect to 100 parts by mass of the total amount of the polyolefin (A) and the EVOH (B). This is achieved by providing a resin composition.

  The above resin composition is preferably prepared by previously melt-kneading the polyolefin (A), the higher fatty acid metal salt (C) and the partially saponified EVA (E) to obtain a master batch, and the master batch and the polyolefin (A) , EVOH (B) and a conjugated polyene compound (D) are obtained by melt-kneading.

  A resin composition obtained by adding 0.0001 to 10 parts by mass of hydrotalcite (F) to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B) in the above resin composition This is a preferred embodiment of the present invention.

  In addition, the ethylene-vinyl acetate copolymer saponification product (G) (hereinafter referred to as “ethylene saponification copolymer”) having an ethylene content of 68 to 98 mol% and a vinyl acetate unit saponification degree of 20% or more. Also, a resin composition obtained by adding 0.3 parts by mass or more of S-EVOH (G)) to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B) is also suitable for the present invention. Embodiment.

  Further, as partially saponified EVA (E), it is also possible to use a saponified ethylene-vinyl acetate copolymer having an ethylene content of 50 to 98 mol% and a saponification degree of vinyl acetate units of 0.5 to 19 mol%. It is a preferred embodiment of the invention.

  Furthermore, at least a layer made of any of the above resin compositions and a layer made of a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 65 mol% and a saponification degree of vinyl acetate units of 96% or more. A multilayer structure comprising two layers is also a preferred embodiment of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can suppress the production | generation of the EVOH aggregate in a micro area | region, improves dispersibility, and can suppress generation | occurrence | production of the fluid abnormality resulting from this aggregate is provided. be able to. The resin composition of the present invention can be used as a recovered regrind layer even when a scrap of a laminate having a polyolefin layer and an EVOH layer is used as a raw material, and a molded product having no appearance defect can be obtained.

  The resin composition of the present invention comprises a polyolefin (A), EVOH (B), a higher fatty acid metal salt (C), a conjugated polyene compound (D), and a partially saponified EVA (E), and the polyolefin (A) The mass ratio of the EVOH (B) is 60:40 to 99.9: 0.1, and the higher fatty acid metal salt (C) is a total amount of 100 parts by mass of the polyolefin (A) and the EVOH (B). In the range of 0.0001 to 10 parts by mass relative to 100 parts by mass of the conjugated polyene compound (D) with respect to 100 parts by mass of the polyolefin (A) and the EVOH (B), The modified EVA (E) is contained in an amount of 0.3 parts by mass or more based on 100 parts by mass of the total amount of the polyolefin (A) and the EVOH (B).

  Examples of the polyolefin (A) in the present invention include polyethylene (low density, linear low density, medium density, high density, etc.); α such as ethylene and 1-butene, 1-hexene, 4-methyl-1-pentene, etc. -Ethylene copolymers copolymerized with olefins or acrylic esters; polypropylene (homopolypropylene, random polypropylene, block polypropylene, etc.); propylene and ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, etc. Propylene copolymer obtained by copolymerization of α-olefins; modified polypropylene blended with rubber polymer; poly (1-butene), poly (4-methyl-1-pentene), maleic anhydride added to the above-mentioned polyolefin Modified polyolefins that have been acted on; including ionomer resins. In the present invention, as the polyolefin (A), it is preferable to use a polypropylene resin such as polypropylene or a propylene copolymer, or a polyethylene resin such as polyethylene or an ethylene copolymer, among which a polypropylene resin is used. Is more preferable. These polyolefin (A) may be used individually by 1 type, and may mix and use 2 or more types. Of these polyolefins (A), polyolefins containing 1 to 300 ppm, preferably 3 to 150 ppm of halogen compounds as impurities contained in polymerization catalyst residues or additives such as fillers and pigments are used. In such a case, the effects of the present invention can be obtained more remarkably.

  EVOH (B) used in the present invention is a saponified (hydrolyzed) vinyl acetate unit in an ethylene-vinyl acetate copolymer. EVOH having a low ethylene content and a high saponification degree (hydrolysis degree) of vinyl acetate units tends to have poor compatibility with polyolefins. On the other hand, EVOH having a high ethylene content and a low saponification degree (hydrolysis degree) of vinyl acetate units tends to be poor in thermal stability of EVOH itself. From this viewpoint, the ethylene content of EVOH (B) used in the present invention is in the range of 20 to 65 mol%, preferably in the range of 20 to 60 mol%, and in the range of 20 to 50 mol%. Is more preferable. On the other hand, the saponification degree of the vinyl acetate unit of EVOH (B) is preferably 96% or more, more preferably 98% or more, and further preferably 99% or more. In particular, EVOH having an ethylene content in the range of 20 to 65 mol% and a saponification degree of 99% or more can be used as a container excellent in properties such as gas barrier properties by being laminated with the polyolefin (A). Since it is obtained, it is particularly important as an application target of the present invention.

  EVOH (B) may be modified with other polymerizable monomers within a range not inhibiting the effects of the present invention, generally within a range of 5 mol% or less. Examples of the polymerizable monomer include α-olefins such as propylene, 1-butene, 1-hexene and 4-methyl-1-pentene; esters such as acrylic acid esters and methacrylic acid esters; maleic acid, fumaric acid, Higher fatty acid such as itaconic acid or vinyl ester thereof; alkyl vinyl ether; N- (2-dimethylaminoethyl) methacrylamide or quaternized product thereof, N-vinylimidazole or quaternized product thereof, N-vinylpyrrolidone, N, N- Examples include butoxymethylacrylamide, vinyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilane.

  EVOH (B) has a melt index (MI; measured at 190 ° C. under a load of 2160 g) of 0.1 g / 10 min or more, preferably 0.5 g / 10 min or more, and preferably 100 g / 10 min or less. Is preferably 50 g / 10 min or less, and most preferably 30 g / 10 min or less. At this time, from the viewpoint of dispersibility of EVOH (B), when MI of EVOH (B) is MI (B) and MI of polyolefin (A) (measured at 190 ° C. under a load of 2160 g) is MI (A) The MI (B) / MI (A) is preferably in the range of 0.1 to 100, and more preferably in the range of 0.3 to 50.

  The mass ratio of polyolefin (A) and EVOH (B) in the resin composition of the present invention is in the range of polyolefin (A): EVOH (B) = 60: 40 to 99.9: 0.1, It is important for obtaining the effect of the present invention remarkably. In such a mass ratio, when EVOH (B) is present in a larger amount than 60:40, it is difficult to sufficiently obtain an effect of suppressing aggregation in the microscopic region of EVOH (B), while 99.9: 0. When the amount of polyolefin (A) is larger than 1., the effect of the present invention cannot be sufficiently confirmed. From this viewpoint, the mass ratio of the polyolefin (A) to EVOH (B) is more preferably in the range of 65:35 to 99.7: 0.3.

  As the higher fatty acid metal salt (C) used in the present invention, a metal salt such as lauric acid, stearic acid, myristic acid, particularly a metal salt of Group I, Group II or Group III of the periodic table, such as sodium salt, A potassium salt, a calcium salt, a magnesium salt, and a zinc salt are mentioned. Among these, a metal salt of Group II of the periodic table such as calcium salt and magnesium salt is preferable because the effects of the present invention can be obtained with a small amount of addition.

  If the amount of the higher fatty acid metal salt (C) is too small, the effects of the present invention cannot be sufficiently obtained. On the other hand, if it is too large, the thermal degradation of EVOH (B) is promoted, and foaming due to decomposition gas or coloring There is a concern that causes. For this reason, the addition amount of the higher fatty acid metal salt (C) is in the range of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the total amount of the polyolefin (A) and EVOH (B), and 0.001 to 1 More preferably, it is in the range of parts by mass.

  The conjugated polyene compound (D) used in the present invention is a structure in which carbon-carbon double bonds and carbon-carbon single bonds are alternately connected, and the number of carbon-carbon double bonds is two or more. , A compound having a so-called conjugated double bond. The conjugated polyene compound (D) is a conjugated diene having a structure in which two carbon-carbon double bonds and one carbon-carbon single bond are alternately connected, three carbon-carbon double bonds and two. A conjugated triene having a structure in which carbon-carbon single bonds are alternately connected, or a conjugated polyene compound having a structure in which a larger number of carbon-carbon double bonds and carbon-carbon single bonds are alternately connected. May be. However, if the number of conjugated carbon-carbon double bonds is 8 or more, the molded product may be colored by the color of the conjugated polyene compound itself, so the number of conjugated carbon-carbon double bonds is 7 or less. A certain polyene is preferred. Further, a plurality of conjugated double bonds composed of two or more carbon-carbon double bonds may be present in one molecule without being conjugated with each other. For example, a compound having three conjugated trienes in the same molecule such as tung oil is also included in the conjugated polyene compound (D). In addition to the conjugated double bond, the conjugated polyene compound (D) further includes other functional groups such as carboxyl groups and salts thereof, hydroxyl groups, ester groups, carbonyl groups, ether groups, amino groups, imino groups, amide groups, cyano groups. Group, diazo group, nitro group, sulfone group, sulfoxide group, sulfide group, thiol group, sulfonic acid group and its salt, phosphoric acid group and its salt, phenyl group, halogen atom, double bond, triple bond, etc. It may have a functional group.

  Specific examples of the conjugated polyene compound (D) 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 Butadiene, 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, oximene, ferrandrene, myrcene, farnesene, semblene, sorbine Conjugated diene compounds comprising a conjugated structure of two carbon-carbon double bonds such as acid, sorbic acid ester, sorbate, and abietic acid; 1,3,5-hexatriene, 2,4,6-octatriene-1 -Conjugated trie composed of a conjugated structure of three carbon-carbon double bonds such as carboxylic acid, eleostearic acid, tung oil, cholecalciferol, etc. Compound; cyclooctatetraene, 2,4,6,8 Dekatetoraen-1-carboxylic acid, retinol, carbon atoms such as retinoic acid - such as conjugated polyene compound comprising carbon double bond of four or more conjugated structure. As these conjugated polyene compounds (D), one type of compound may be used alone, or two or more types of compounds may be used in combination.

  The addition amount of the conjugated polyene compound (D) is in the range of 0.000001 to 1 part by mass and in the range of 0.00001 to 1 part by mass with respect to 100 parts by mass of the total amount of the polyolefin (A) and EVOH (B). It is more preferable that When the addition amount is less than 0.000001 parts by mass with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B), the effect of the present invention cannot be sufficiently obtained, while the addition amount is polyolefin ( When the amount exceeds 1 part by mass with respect to 100 parts by mass of the total amount of A) and EVOH (B), there is a concern of promoting gelation of the resulting resin composition.

  The conjugated polyene compound (D) may be blended directly into the mixture of the polyolefin (A) and EVOH (B). However, when the addition amount is very small, from the viewpoint of being uniformly dispersed in the resin composition of the present invention, It is preferable to blend in EVOH (B) having good compatibility in advance.

  The partially saponified EVA (E) constituting the resin composition of the present invention is a random copolymer obtained by polymerizing ethylene and vinyl acetate by a known method, a terpolymer obtained by copolymerizing other monomers, It is obtained by saponifying at least a part of vinyl acetate units of modified EVA modified by grafting or the like. Although not necessarily limited, 2-50 mol% is suitable for content of the vinyl acetate unit of partially saponified EVA (E), and it is more preferable that it is 5-25 mol%. If the content of vinyl acetate units is less than 2 mol% or more than 50 mol%, a sufficient effect for preventing aggregation of EVOH (B) may not be obtained. The saponification degree of the vinyl acetate unit is preferably 0.5 to 19 mol%, and more preferably 0.5 to 15 mol%. The melt index (MI; measured at 190 ° C. under a load of 2160 g) of the partially saponified EVA (E) is preferably 0.1 to 50 g / 10 min or more, and 0.5 to 30 g / 10 min or more. More preferably, it is 1 to 20 g / 10 min or more.

  The amount of partially saponified EVA (E) added is 0.3 parts by mass or more, more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B). is there. When the addition amount is less than 0.3 parts by mass, the effect of adding partially saponified EVA (E) may not be sufficiently obtained. On the other hand, the upper limit of the addition amount is not particularly limited, but even if the addition amount is increased, the EVOH dispersibility is not improved beyond a certain level, so 30 parts by mass or less is sufficient for practical use.

  In addition to the above-described polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D) and partially saponified EVA (E) as components constituting the resin composition of the present invention, Further, hydrotalcite (F) can be added. When hydrotalcite (F) is used as a constituent of the resin composition of the present invention, it is preferable because the dispersibility of EVOH (B) in the resin composition can be improved.

As hydrotalcite (F) in the present invention, in particular,
_{M x Al y (OH) 2x} + 3y-2z (A) z · aH 2 O
(M represents Mg, Ca or Zn, A represents CO ₃ or HPO ₄ , x, y and z are positive integers, and a is an integer of 0 or more)
Hydrotalcite which is a double salt represented by the following can be exemplified, and among them, the following are particularly preferable.
Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O
_{Mg 8 Al 2 (OH) 20} CO 3 · 5H 2 O
Mg ₅ Al ₂ (OH) ₁₄ CO ₃ .4H ₂ O
_{Mg 10 Al 2 (OH) 22} (CO 3) 2 · 4H 2 O
_{Mg 6 Al 2 (OH) 16} HPO 4 · 4H 2 O
Ca ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O
Zn ₆ Al ₆ (OH) ₁₆ CO ₃ .4H ₂ O

  When hydrotalcite (F) is further added, the addition amount is in the range of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B). More preferably, it is in the range of ˜1 part by mass. When the addition amount is less than 0.0001 parts by mass with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B), the effect of the present invention is not sufficiently obtained, while the addition amount is polyolefin ( If the total amount of A) and EVOH (B) exceeds 10 parts by mass with respect to 100 parts by mass, the thermal degradation of EVOH in the resulting resin composition is promoted to cause foaming or coloring due to decomposition gas. There is.

  In addition to the above-described polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D), and partially saponified EVA (E) as components constituting the resin composition of the present invention Further, S-EVOH (G) can be added. Even when S-EVOH (G) is used as a constituent of the resin composition of the present invention, the dispersibility of EVOH (B) in the resin composition can be improved, which is preferable.

  S-EVOH (G) is an ethylene-vinyl acetate copolymer saponified product having an ethylene content of 68 to 98 mol% and a vinyl acetate unit saponification degree of 20% or more. EVOH used for ordinary food packaging materials Unlike ethylene, the ethylene content is high, and there is an effect of remarkably improving the compatibility of the polyolefin (A) and EVOH (B). The ethylene content of S-EVOH (G) is preferably 70 mol% or more, while it is preferably 96 mol% or less, more preferably 94 mol% or less. Further, the saponification degree of the vinyl acetate unit is more preferably 30% or more, and further preferably 40% or more. The upper limit of the saponification degree is not particularly limited, and may be 99 mol% or more, and those having a saponification degree of substantially 100% can be used. When the ethylene content is less than 68 mol% or more than 98 mol%, or the saponification degree of vinyl acetate units is less than 20%, the effects of the present invention are not sufficiently achieved.

  In addition, the ethylene content of S-EVOH (G) is naturally higher than the ethylene content of EVOH (B) in the present invention from the definition thereof. The difference between the ethylene content of S-EVOH (G) and the ethylene content of EVOH (B) is preferably at least 10 mol%, more preferably 20 mol% or more, polyolefin (A) and EVOH. It is more preferable from the viewpoint of improving the compatibility of (B).

  The MI of S-EVOH (G) (measured at 190 ° C. under a load of 2160 g) is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, and 1 g / 10 min. More preferably, it is the above. On the other hand, the MI of S-EVOH (G) is preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, and further preferably 30 g / 10 min or less. S-EVOH (G) may be modified with an unsaturated carboxylic acid or a derivative thereof. Examples of the unsaturated carboxylic acid or a derivative thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. And maleic acid; methyl or ethyl esters of the aforementioned acids; maleic anhydride, itaconic anhydride, and the like. These may be used alone or in combination of two or more.

  When S-EVOH (G) is present as a constituent in the resin composition of the present invention, the preferred addition amount is 0.3 mass relative to 100 mass parts of the total amount of polyolefin (A) and EVOH (B). Part or more, and more preferably 0.5 part by weight or more. When the addition amount is less than 0.3 parts by mass, the effect of adding S-EVOH (G) may not be sufficiently obtained. On the other hand, the upper limit of the addition amount is not particularly limited, but even if the addition amount is increased, the EVOH dispersibility is not improved beyond a certain level, so 30 parts by mass or less is sufficient for practical use.

  Hydrotalcite (F) and S-EVOH (G) are each independently polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D) and partially saponified EVA (E). Although it may be added to the resin composition of the present invention which is constituted further, by adding both in combination, a higher aggregation effect in the microscopic region of EVOH (B) can be obtained.

  Adding a modified polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof to the resin composition of the present invention is also effective in suppressing aggregation in the microscopic region of EVOH (B). Here, the modified polyolefin resin is an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, its ester or its anhydride; methyl acrylate, methyl methacrylate From unsaturated carboxylic acid derivatives such as ethyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, vinyl acetate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate, sodium methacrylate; A polyolefin resin modified with at least one selected unsaturated carboxylic acid or derivative thereof. Preferred examples of the polyolefin resin before modification include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, and the like.

  In addition, as long as various known additives for improving various characteristics such as thermal stability during melt extrusion molding of EVOH are within a range that does not impair the effects of the present invention, the EVOH constituting the resin composition of the present invention Since the deterioration suppression of (B) can be expected, it is preferably added. These additives include organic acids such as acetic acid and lactic acid, inorganic acids such as hydrochloric acid and phosphoric acid, and metal salts with periodic group I, II and III metals, and boron such as boric acid. Examples thereof include higher fatty acids such as compounds and stearic acid. In particular, the addition of boric acid is effective in suppressing aggregation of EVOH (B), and the preferred addition amount is 0.0001 to 0.1 mass with respect to 100 mass parts of the total amount of polyolefin (A) and EVOH (B). Part range. When boric acid is added, if the added amount exceeds 0.1 parts by mass with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B), EVOH (B) tends to aggregate. Become.

  Next, a method of obtaining the resin composition of the present invention by mixing the polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D) and partially saponified EVA (E), A method for molding the resin composition will be described.

  The mixing method for obtaining the resin composition of the present invention is not particularly limited, and polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D), and partially saponified EVA (E) A high-fatty acid metal salt (C) and / or a conjugated polyene compound (D) are pre-blended with polyolefin (A) and / or EVOH (B), and the remaining components are mixed. A method of dry blending and melt-kneading with the polyolefin (A), a mixture of the polyolefin (A), the conjugated polyene compound (D) preliminarily mixed with the EVOH (B), and the polyolefin (A) are preferable examples. And a method in which a higher fatty acid metal salt (C) and a partially saponified EVA (E) are blended in advance and are dry blended and melt-kneaded.

  In particular, as described above, when the conjugated polyene compound (D) is preliminarily blended with EVOH (B), the effect of the present invention can be enhanced even if the addition amount of the conjugated polyene compound (D) is reduced. . The method of pre-blending the conjugated polyene compound (D) with EVOH (B) is not particularly limited, but EVOH (B) is dissolved in a good solvent of EVOH (B) such as a water / methanol mixed solvent. B) 0.000001-10 parts by mass of the conjugated polyene compound (D) is dissolved with respect to 100 parts by mass, the mixed solution is extruded into a poor solvent from a nozzle or the like, precipitated and solidified, washed and dried. Examples thereof include a method of obtaining EVOH (B) containing the conjugated polyene compound (D).

  On the other hand, the method of blending the higher fatty acid metal salt (C) and the partially saponified EVA (E) in advance with the polyolefin (A) is not particularly limited, but the polyolefin (A), the higher fatty acid metal salt (C) and the partially saponified EVA are not particularly limited. Examples include a method of dry blending (E); a method of melt kneading and pelletizing polyolefin (A), higher fatty acid metal salt (C) and partially saponified EVA (E), that is, a method of obtaining a masterbatch. . Among these methods, the latter method is preferred from the viewpoint that the higher fatty acid metal salt (C) is usually a powder because the handling becomes easier.

  There is no particular limitation on the blending method when hydrotalcite (F) and S-EVOH (G) are added. Polyolefin (A), EVOH (B), higher fatty acid metal salt (C), conjugated polyene compound (D ) And partially saponified EVA (E) and hydrotalcite (F) and / or S-EVOH (G) may be dry blended and melt-kneaded. In the case where a polyolefin (A), a higher fatty acid metal salt (C) and EVA (E) are previously melt-kneaded and pelletized to obtain a master batch, hydrotalcite (F) and / or Alternatively, S-EVOH (G) is also blended and pelletized at the same time, which is preferable from the viewpoint of reducing the number of materials to be handled during the final melt-kneading of the resin composition of the present invention.

  Moreover, it is also free to mix | blend other additives other than having mentioned above with the resin composition of this invention in the range which does not inhibit the effect of this invention. Examples of such additives include antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, or other polymer compounds. Specific examples of the additive include the following.

  Antioxidant: 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4′-thiobis (6-t-butylphenol), 2,2′-methylenebis ( 4-methyl-6-t-butylphenol), octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate, 4,4′-thiobis (6-t-butylphenol), etc. .

  UV absorber: ethylene-2-cyano-3,3′-diphenyl acrylate, 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-octoxybenzophenone and the like.

Plasticizer: Dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester, etc.
Antistatic agents: pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, carbowax, etc.
Lubricant: Ethylene bisstearamide, butyl stearate, etc.

Colorant: Titanium oxide, carbon black, phthalocyanine, quinacridone, indoline, azo pigment, bengara, etc.
Filler: Glass fiber, asbestos, ballastite, calcium silicate, etc.

  Of these additives, colorants and fillers often contain impurities that promote aggregation in the microscopic region of EVOH (B) constituting the resin composition of the present invention. Therefore, when these additives are included, it is necessary to increase the blending amount of the higher fatty acid metal salt (C) and / or the conjugated polyene compound (D) and / or the partially saponified EVA (E) as necessary. There can be.

  Many other polymer compounds can also be blended in the resin composition of the present invention to the extent that the effects of the present invention are not inhibited.

  Examples of the means for mixing the components for obtaining the resin composition of the present invention include a ribbon blender, a high-speed mixer / conical mixer, a mixing roll, an extruder, and an intensive mixer.

  In addition, the resin composition of the present invention uses a well-known melt extrusion molding machine, compression molding machine, transfer molding machine, injection molding machine, blow molding machine, thermoforming machine, rotational molding machine, dip molding machine, etc. It can be formed into an arbitrary molded product such as a film, sheet, tube, bottle, or cup. The extrusion temperature at the time of molding is the type of polyolefin (A) constituting the resin composition of the present invention, the melt index of polyolefin (A) and EVOH (B), the composition ratio of polyolefin (A) and EVOH (B), or molding Although it is appropriately selected depending on the type of the machine, it is often in the range of 170 to 350 ° C.

When using the resin composition of this invention as a layer structure of the multilayered structure containing the layer which consists of polyolefin and EVOH, the layer structure which has arrange | positioned at least 1 layer in arbitrary positions can be taken. As such a layer structure, when the resin composition of the present invention is represented by F, polyolefin is A, EVOH is B, and adhesive resin is represented by AD, for example, the following layer structure is represented. Here, as the AD, the above-described modified polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof can be preferably used.
3 layers A / F / B
4 layers F / B / AD / A, A / F / AD / B
5 layers F / AD / B / AD / F, A / F / B / AD / A, A / F / B / F / A
6 layers A / F / AD / B / AD / A
7 layers A / F / AD / B / AD / F / A

  In such a multilayer structure, the resin composition of the present invention can be substituted with a melt-kneaded scrap of the multilayer structure. In addition to the multilayer structure, other polyolefin molded body scraps can be mixed and melt-kneaded. Therefore, when an AD layer is present in the multilayer structure, AD is included as a constituent in the resin composition of the present invention.

  Since the multilayer structure having the above-described layer structure contains EVOH excellent in gas barrier properties, it is useful as a packaging material for foods, pharmaceuticals, medical devices and the like that require gas barrier properties.

  As a multilayer molding method, generally, a number of extruders corresponding to the type of the resin layer are used, and so-called coextrusion molding is performed in which the melted resin flows in the extruder are co-extruded in a layered state. The method carried out by is preferred. As another method, a multilayer molding method such as extrusion coating or dry lamination may be employed. In addition, by carrying out stretching such as uniaxial stretching, biaxial stretching or blow stretching of a single molded article of the resin composition of the present invention or a multilayer structure containing the resin composition of the present invention, mechanical properties, gas barrier properties, etc. Can be obtained.

  The molded product obtained by using the resin composition of the present invention has a beautiful appearance, and aggregation of EVOH in the micro area in the resin composition of the present invention is suppressed and uniformly dispersed. Since it has excellent mechanical properties and gas barrier properties, its industrial significance is great.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the following production examples, examples and comparative examples, (part) is expressed on a mass basis unless otherwise specified.

[Method for quantifying conjugated polyene compound (D) blended in EVOH]
The amount of the conjugated polyene compound (D) contained in EVOH was quantified by the following procedure. EVOH containing the conjugated polyene compound (D) was pulverized, and 10 g of coarse particles removed by a 100 mesh sieve were Soxhlet extracted with 100 ml of chloroform for 48 hours. The amount of the conjugated polyene compound in the extract was quantified by high-performance liquid chromatography by preparing a calibration curve using each conjugated polyene compound sample.

Production Example 1
(1) Intrinsic viscosity [η] _ph measured at 30 ° C. using a mixed solution of ethylene content of 32 mol%, saponification degree of 99.8 mol%, water / phenol = 15/85 (mass ratio) as 0 0.092 l / g of EVOH 2000 parts was put into 18000 parts of a mixed solvent of water / methanol = 40/60 (mass ratio) and stirred at 60 ° C. for 6 hours to completely dissolve the mixture. To this solution, 2 parts of sorbic acid as a conjugated polyene compound (D) was added, and further stirred at 60 ° C. for 1 hour to completely dissolve sorbic acid, thereby obtaining an EVOH solution containing sorbic acid. This EVOH solution was continuously extruded from a nozzle having a diameter of 4 mm into a coagulation bath of water / methanol = 5/95 (mass ratio) adjusted to 0 ° C. to coagulate EVOH in a strand form. This strand was introduced into a pelletizer to obtain a porous EVOH chip.

  (2) The porous EVOH chip obtained in the above (1) was washed sequentially at 20 ° C. using 2000 parts of 0.1 mass% acetic acid aqueous solution and then 2000 parts of ion-exchanged water per 100 parts of the chip. It was immersed in 2000 parts of a 092 mass% boric acid aqueous solution at 20 ° C. for 4 hours. The EVOH chip was removed and separated, dried with a hot air dryer at 80 ° C. for 4 hours, and further dried at 100 ° C. for 16 hours. The boric acid content in the obtained EVOH chip was 0.11 part with respect to 100 parts of EVOH, and the sorbic acid content was 0.01 part. The EVOH had a melt index (ASTM-D1238, 190 ° C., 2160 g load) of 1.6 g / 10 min. This EVOH chip is referred to as EVOH (B1).

Production Example 2
In Production Example 1 (1), the same operation as in Production Example 1 was carried out except that 2 parts of β-myrcene was used as the conjugated polyene compound (D) instead of 2 parts of sorbic acid, and β- EVOH (B2) containing 0.05 part of myrcene was obtained.

Production Example 3
In Production Example 1 (1), EVOH (B3) was obtained in the same manner as in Production Example 1 except that sorbic acid was not added to the EVOH water / methanol solution.

Production Example 4
In Production Example 1 (1), the same operation as in Production Example 1 was carried out except that the amount of sorbic acid added to the water / methanol solution of EVOH was changed from 2 parts to 0.4 parts, and 100 parts of EVOH was obtained. EVOH (B4) having a sorbic acid content of 0.002 part was obtained.

Production Example 5
In Production Example 1 (1), the same operation as in Production Example 1 was carried out except that the amount of sorbic acid added to the water / methanol solution of EVOH was changed from 2 parts to 0.65 parts, with respect to 100 parts of EVOH. EVOH (B5) having a sorbic acid content of 0.0032 part was obtained.

Production Example 6
(1) Intrinsic viscosity [η] _ph measured at 30 ° C. using a mixed solution of ethylene content of 32 mol%, saponification degree of 99.8 mol%, water / phenol = 15/85 (mass ratio) as 0 A porous EVOH chip was obtained in the same manner as in Production Example 1 except that 112 l / g EVOH was used.
(2) The porous EVOH chip obtained in (1) above is washed sequentially with a 0.1% by mass acetic acid aqueous solution and ion-exchanged water in the same manner as in Production Example 1 (2), and then into an aqueous solution containing boric acid. A drying operation was performed in the same manner as in Production Example 1 (2) without immersing to obtain EVOH (B6). The melt index (ASTM-D1238, 190 ° C., 2160 g load) of this EVOH was 1.5 g / 10 min.

Production Example 7
40 parts of low density polyethylene {LDPE, melt index 1.5 g / 10 min (ASTM-D1238, 190 ° C.), hereinafter simply referred to as LDPE}, 2 parts of calcium stearate which is a higher fatty acid metal salt (C), and vinyl acetate Partially saponified EVA having a unit content of 7.1 mol%, a vinyl acetate unit saponification degree of 6 mol%, and a melt index (ASTM-D1238, 190 ° C., 2160 g load) of 2.5 g / 10 min. E) After 60 parts of dry blending, the obtained mixture was melt-kneaded at an extrusion temperature of 200 ° C. using a 30 mmφ co-directional twin-screw extruder (TEX-30N (trade name), manufactured by Nippon Steel). Pelletized to obtain a master batch (MB1).

Production Example 8
In Production Example 7, 2 parts of Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O as hydrotalcite (F) was further added and dry blended, and the resulting mixture was the same as in Production Example 7. To obtain a master batch (MB2).

Production Example 9
In Production Example 7, pelletization was performed in the same manner as in Production Example 7 except that partially saponified EVA (E) was not added to obtain a master batch (MB3).

Production Example 10
In Production Example 7, a master batch (MB4) was obtained by pelletizing in the same manner as in Production Example 7 except that calcium stearate was not added.

Production Example 11
In Production Example 7, pelletization was performed in the same manner as in Production Example 7 except that 2 parts of magnesium stearate was used instead of 2 parts of calcium stearate as the higher fatty acid metal salt (C) to obtain a master batch (MB5).

Production Example 12
In Production Example 7, pelletization was performed in the same manner as in Production Example 7 except that the addition amount of partially saponified EVA (E) was changed from 60 parts to 14 parts to obtain a master batch (MB6).

Example 1
As the polyolefin (A), polypropylene {melt index 5.4 g / 10 min (ASTM-D1238, 230 ° C.), hereinafter referred to as PP} was used. 88 parts of this PP, 10 parts of EVOH (B1), and 5.1 parts of master batch (MB1) were dry blended to obtain a mixture. The composition of this mixture is 88 parts PP of polyolefin (A), 2 parts of LDPE, 10 parts of EVOH (B), 0.1 part of calcium stearate, higher fatty acid metal salt (C), conjugated polyene compound The sorbic acid which is (D) is 0.001 part. Using a 20 mmφ single screw extruder (Laboplast Mill manufactured by Toyo Seiki Co., Ltd.) and a 300 mm width T die, a 40 μm thick single layer film of this mixture was formed. The film forming temperature was 190 to 230 ° C for the extruder and 220 ° C for the die. The screw rotation speed was 40 rpm, and the discharge rate was 0.95 kg / hour.
One hour after the mixture was put into the extruder hopper, a film sample of about 50 m was taken. A 10 cm × 10 cm frame was written at the center of the frame, and the frame was held in front of a desktop fluorescent lamp. The number of EVOH aggregates having a diameter (maximum diameter) of about 200 μm or more in the frame was counted. This count measurement was carried out for a total of 100 locations every 20 cm in the length direction of the film, and the average number of EVOH aggregates per 100 cm ² was calculated to be 0.12.

Example 2
A dry blend mixture was obtained in the same manner as in Example 1 except that 10 parts of EVOH (B2) containing β-myrcene was used instead of 10 parts of EVOH (B1) containing sorbic acid. A single layer film was formed from the mixture, and the number of EVOH aggregates in the obtained film was counted, and found to be 0.14 per 100 cm ² .

Example 3
In Example 1, instead of dry blending 5.1 parts of the master batch (MB1), the same as Example 1 except that 5.2 parts of the master batch (MB2) containing hydrotalcite (F) was dry blended. A dry blend mixture was obtained, a single layer film was formed from the mixture, and the number of EVOH aggregates in the obtained film was counted. As a result, it was 0.05 per 100 cm ² .

Comparative Example 1
In Example 1, 90 parts of PP and 10 parts of EVOH (B3) containing no conjugated polyene compound (D) were dry blended. Using this mixture, a single-layer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted. As a result, the number was 100 or more per 100 cm ² .

Comparative Example 2
In Example 1, a masterbatch (MB3) containing 88 parts of PP, 10 parts of EVOH (B3) not containing the conjugated polyene compound (D), and calcium stearate which is a higher fatty acid metal salt (C) is 2.1. Partially dry blended. Using this mixture, a monolayer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted. As a result, it was 6.01 per 100 cm ² .

Comparative Example 3
In Example 1, 88 parts of PP, 10 parts of EVOH (B3) containing no conjugated polyene compound (D), and a master containing calcium stearate which is a higher fatty acid metal salt (C) and partially saponified EVA (E) The batch (MB1) was 5.1 parts dry blended. Using this mixture, a single-layer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted. As a result, it was 0.71 per 100 cm ² .

Comparative Example 4
In Example 1, the same procedure as in Example 1 was used, except that 5.1 parts of master batch (MB3) not containing partially saponified EVA (E) was used instead of 5.1 parts of master batch (MB1). When a layer film was formed and the number of EVOH aggregates in the obtained film was counted, it was 6.12 per 100 cm ² .

Example 4
In Example 1, 68 parts of PP, 30 parts of EVOH (B5), and 5.1 parts of a masterbatch (MB1) containing calcium stearate which is a higher fatty acid metal salt (C) and partially saponified EVA (E) A single-layer film was formed in the same manner as in Example 1 except that dry blending was performed, and the number of EVOH aggregates in the obtained film was counted and found to be 0.29 per 100 cm ² .

Example 5
In Example 1, a monolayer film was formed in the same manner as in Example 1 except that 10 parts of EVOH (B6) containing no boric acid was used instead of 10 parts of EVOH (B1). When the number of EVOH aggregates in the film was counted, it was 0.42 per 100 cm ² .

Example 6
In Example 1, a single layer was formed in the same manner as in Example 1 except that 5.1 parts of master batch (MB5) containing magnesium stearate was used instead of 5.1 parts of master batch (MB1) containing calcium stearate. A film was formed, and the number of EVOH aggregates in the obtained film was counted, and found to be 0.11 per 100 cm ² .

Comparative Example 5
In Example 1, the same procedure as in Example 1 was used except that 5.1 parts of the master batch (MB4) not containing the higher fatty acid metal salt (C) was used instead of 5.1 parts of the master batch (MB1). When a layer film was formed and the number of EVOH aggregates in the obtained film was counted, it was 1.18 per 100 cm ² .

Comparative Example 6
In Example 1, a monolayer film was formed in the same manner as in Example 1 except that 48 parts of PP, 50 parts of EVOH (B4), and 5.1 parts of master batch (MB1) were dry blended. When the number of EVOH aggregates in the obtained film was counted, it was 3.50 per 100 cm ² .

Comparative Example 7
4. Master batch (MB1) containing 88 parts of PP, 10 parts of EVOH (B1) containing conjugated polyene compound (D), calcium stearate as higher fatty acid metal salt (C) and partially saponified EVA (E) One part was dry blended, and further 19.9 parts of calcium stearate was added and dry blended. Using this mixture, an attempt was made to form a single-layer film in the same manner as in Example 1. However, liquid calcium stearate separated from the resin was ejected from the lip portion of the T-die and a large number of films were formed on the film. Because of the holes, it was not possible to count the number of EVOH aggregates.

Example 7
In Example 1, a monolayer film was formed in the same manner as in Example 1 except that 2.8 parts of master batch (MB6) was used instead of 5.1 parts of master batch (MB1). The number of EVOH aggregates in the resulting film was counted and found to be 0.31 per 100 cm ² .

Example 8
In Example 1, EVOH (B3) containing no conjugated polyene compound (D) was used in place of 10 parts of EVOH (B1), and dry blended in the same manner as in Example 1 to obtain the resulting mixture. Further, 0.001 part of sorbic acid, which is a conjugated polyene compound (D), was further dry blended with 10 parts of EVOH (B3). Using the obtained mixture, a single-layer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted. As a result, it was 0.28 per 100 cm ² .

Example 9
In Example 1, high-density polyethylene {melt index 0.9 g / 10 min (ASTM-D1238, 190 ° C), hereinafter referred to as HDPE}} 88 parts was used as the polyolefin (A) instead of PP88 parts. A single layer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted, and it was 0.17 per 100 cm ² .

Comparative Example 8
In Example 1, 88 parts of PP, 10 parts of EVOH (B3) not containing conjugated polyene compound (D), and 5.1 parts of masterbatch (MB1) were dry blended, and further conjugated polyene compound (D) 5 parts of sorbic acid was added and uniformly dry blended. Using this mixture, a single-layer film was formed in the same manner as in Example 1, and the number of EVOH aggregates in the obtained film was counted. As a result, the number was 100 or more per 100 cm ² .

Comparative Example 9
In Example 9, a monolayer film was formed in the same manner as in Example 9 except that 90 parts of HDPE was used and the master batch (MB1) was not added, and the number of EVOH aggregates in the obtained film was counted. As a result, it was 4.56 per 100 cm ² .

Example 10
A coextrusion film forming test including the resin composition layer of the present invention was carried out using the following four types of seven-layer coextrusion cast film forming equipment.
Extruder (1): uniaxial, screw diameter 65 mm, L / D = 22, for outer layer polyolefin Extruder (2): uniaxial, screw diameter 40 mm, L / D = 26, extruder for resin composition of the present invention (3 ): Single screw, screw diameter 40 mm, L / D = 22, Adhesive resin extruder (4): Single screw, screw diameter 40 mm, L / D = 26, EVOH Extruder (1) PP and extruder ( 2) In the same manner as in Example 1, 88 parts of PP, 10 parts of EVOH (B1), and 5.1 parts of masterbatch (MB1) were dry-blended, and the resulting mixture was added to the maleic anhydride in the extruder (3). An acid-modified polypropylene-based adhesive resin (ADMER QF-500 (trade name), manufactured by Mitsui Chemicals) was fed to the extruder (4) with EVOH (B1), and co-extrusion film formation was performed. The extrusion temperature is 200 to 240 ° C. for the extruder (1), 160 to 220 ° C. for the extruder (2), 160 to 230 ° C. for the extruder (3), and 170 to 210 ° C. for the extruder (4). The die was set at 220 ° C. The composition and thickness of the formed multilayer film were as follows: PP / resin composition of the present invention / adhesive resin / EVOH / adhesive resin / resin composition of the present invention / PP = 30/15 / 2.5 / 5/2. .5 / 15/30 .mu.m, total thickness of 100 .mu.m, 4 types and 7 layers were used.
When the multilayer film after 2 hours from the start of film formation was sampled and the appearance was observed, the appearance defect due to aggregation of EVOH was hardly recognized, and a multilayer film having no practical problem was obtained.

Comparative Example 10
Except that the mixture fed to the extruder (2) of Example 10 was changed to a mixture obtained by dry blending 10 parts of PP90 parts EVOH (B3) used in Comparative Example 1, it was the same as Example 10. A multilayer film was obtained. The resulting multilayer film was severely deteriorated in appearance due to EVOH agglomerates and was difficult to put to practical use.

Comparative Example 11
The mixture fed to the extruder (2) of Example 10 was used in Comparative Example 3, and 88 parts of PP, 10 parts of EVOH (B3) containing no conjugated polyene compound (D), and higher fatty acid metal salt ( A multilayer film was obtained in the same manner as in Example 10 except that the master batch (MB1) containing calcium stearate (C) and partially saponified EVA (E) was changed to a mixture obtained by dry blending 5.1 parts. The appearance of the obtained multilayer film was better than that of the multilayer film obtained in Comparative Example 10, but still poor appearance due to EVOH agglomerates was clearly observed, and it was difficult to put to practical use. It was.

Comparative Example 12
A masterbatch (MB3) containing 88 parts of PP, 10 parts of EVOH (B1), and partially saponified EVA (E) used in Comparative Example 4 for the mixture fed to the extruder (2) of Example 10 ) Was changed to 5.1 parts dry blended mixture to obtain a multilayer film in the same manner as in Example 10. The appearance of the obtained multilayer film was better than that of the multilayer film obtained in Comparative Example 10, but still poor appearance due to EVOH agglomerates was clearly observed, and it was difficult to put to practical use. It was.

Comparative Example 13
A masterbatch (MB4) containing 88 parts of PP, 10 parts of EVOH (B1), and higher fatty acid metal salt (C) used in Comparative Example 5 for the mixture fed to the extruder (2) of Example 10. ) Was changed to 5.1 parts dry blended mixture to obtain a multilayer film in the same manner as in Example 10. The appearance of the obtained multilayer film was better than that of the multilayer film obtained in Comparative Example 10, but still poor appearance due to EVOH agglomerates was clearly observed, and it was difficult to put to practical use. It was.

Example 11
A masterbatch (MB2) containing 88 parts of PP, 10 parts of EVOH (B1) and hydrotalcite (F) used in Example 3 for the mixture fed to the extruder (2) of Example 10 A multilayer film was obtained in the same manner as in Example 10 except that the mixture was changed to a mixture obtained by dry blending 5.2 parts. The appearance of the obtained multilayer film was even better than that of Example 10, and no appearance defect due to the aggregate of EVOH was observed.

  Tables 1 and 2 collectively show the results of the examples and comparative examples.

  A polyolefin (A), EVOH (B), a higher fatty acid metal salt (C) having 8 to 22 carbon atoms, a conjugated polyene compound (D) having a boiling point of 20 ° C. or higher, and a partially saponified EVA (E), and a polyolefin ( A): EVOH (B) = 60: 40 to 99.9: 0.1 (mass ratio), and the higher fatty acid metal salt (C) is 100 parts by mass of the total amount of polyolefin (A) and EVOH (B). 0.0001 to 10 parts by mass with respect to 100 parts by mass of the conjugated polyene compound (D) with respect to 100 parts by mass of the total amount of the polyolefin (A) and EVOH (B), and the partially saponified EVA. By providing a resin composition having (E) 0.3 parts by mass or more with respect to 100 parts by mass of the total amount of polyolefin (A) and EVOH (B), aggregation of EVOH and its aggregation Pour abnormal appearance defects prevented by, it is possible to obtain a beautiful appearance moldings.

Claims (4)

Polyolefin (A), ethylene-vinyl acetate copolymer saponified product (B) having an ethylene content of 20 to 65 mol%, a vinyl acetate unit saponification degree of 96% or more, and a higher fatty acid metal salt having 8 to 22 carbon atoms ( C), a conjugated polyene compound (D) having a boiling point of 20 ° C. or higher, and an ethylene-vinyl acetate copolymer (E) in which at least a part of vinyl acetate units is saponified, and the polyolefin (A) and the ethylene -The mass ratio of the saponified vinyl acetate copolymer (B) is from 60:40 to 99.9: 0.1, and
In the range of 0.0001 to 10 parts by mass of the higher fatty acid metal salt (C) with respect to 100 parts by mass of the total amount of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B). The polyene compound (D) is in the range of 0.000001 to 1 part by mass with respect to 100 parts by mass of the total amount of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B). Containing 0.3 parts by mass or more of the copolymer (E) with respect to 100 parts by mass of the total amount of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B) , and
The ethylene-vinyl acetate copolymer (E) in which at least a part of the vinyl acetate unit is saponified is ethylene having an ethylene content of 50 to 98 mol% and a vinyl acetate unit saponification degree of 0.5 to 19 mol%. -A resin composition which is a partially saponified vinyl acetate copolymer .   A polyolefin (A), a higher fatty acid metal salt having 8 to 22 carbon atoms (C), and an ethylene-vinyl acetate copolymer (E) in which at least a part of vinyl acetate units is saponified are previously melt-kneaded to prepare a master batch. The obtained master batch, polyolefin (A), saponified ethylene-vinyl acetate copolymer (B) and conjugated polyene compound (D) having a boiling point of 20 ° C or higher are obtained by melt-kneading. Resin composition.   Further, the hydrotalcite (F) is a total of the polyolefin (A) and ethylene-vinyl acetate copolymer saponified product (B) having an ethylene content of 20 to 65 mol% and a saponification degree of vinyl acetate units of 96% or more. The resin composition according to claim 1, which is contained in an amount of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the amount. A layer comprising the resin composition according to any one of claims 1 to 3 , an ethylene-vinyl acetate copolymer ken having an ethylene content of 20 to 65 mol% and a saponification degree of vinyl acetate units of 96% or more. A multi-layer structure comprising at least two layers comprising a compound.