JP7339140B2 - Resin composition excellent in recoverability and multilayer structure using the same - Google Patents

Description

The present invention relates to a resin composition containing a polyolefin and an ethylene-vinyl alcohol copolymer and a method for producing the same.

Conventionally, a multilayer structure containing a layer made of a thermoplastic resin typified by polyolefin and a layer made of an ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as "EVOH") having excellent barrier properties, Taking advantage of its barrier properties, it is used in various applications such as food packaging containers and fuel containers. Such multilayer structures are used as various molded articles such as films, sheets, cups, trays, bottles and tanks. At this time, in some cases, edges and defective products generated when obtaining the above various molded products are collected, melt-molded, and reused as at least one layer of a multilayer structure containing a thermoplastic resin layer and an EVOH layer. . Such recovery techniques are useful in terms of waste reduction and economic efficiency, and are widely used.

However, when reusing a recovered multilayer structure containing a thermoplastic resin layer and an EVOH layer, it may cause gelation due to heat deterioration during melt molding, or may cause a phase called sludge in the die during melt molding. It was sometimes difficult to carry out continuous melt molding for a long period of time due to adhesion of separated foreign matter (due to resin compatibility).

As a method for improving such gelation and compatibility, a method of adding a recovery aid to the recovered EVOH is known. Patent Document 1 describes a method of adding a recovery aid containing an olefin-vinyl carboxylate copolymer and/or a saponified product thereof, a fatty acid metal salt, and/or a specific metal compound to a pulverized material containing EVOH. is described. Further, Patent Document 2 describes a method of adding a recovery aid containing an acid-graft-modified polyolefin resin, a fatty acid metal salt and/or a specific metal compound as a resin composition to be blended with a pulverized product containing EVOH. It is

JP-A-2002-234971 Japanese Patent Application Laid-Open No. 2002-121342

However, when the recovered material obtained using the conventional EVOH recovery aid is repeatedly melt-molded, there are cases where resin such as deteriorated materials adheres to the screw and die, the hue deteriorates, In some cases, the impact strength was inferior.

The present invention has been made to solve the above problems, and a resin composition containing polyolefin (hereinafter sometimes abbreviated as "PO") and EVOH exhibits deterioration in hue and deterioration even when melt-molding is repeated. A resin composition that can reduce the adhesion of resin such as degraded products to screws and dies and that can provide molded articles with excellent impact resistance and appearance, a method for producing the resin composition, and a method using the resin composition An object of the present invention is to provide a multilayer structure.

According to the present invention, the above objects are:
[1] 0.1 to 20 parts by mass of an ethylene-vinyl alcohol copolymer (B) having an ethylene unit content of 15 to 60 mol% and a degree of saponification of 85 mol% or more per 100 parts by mass of polyolefin (A) and 0.1 to 10 parts by mass of a block copolymer (C) of an aromatic vinyl compound and an olefin, wherein the block copolymer (C) of the aromatic vinyl compound and an olefin contains a halogen, an epoxy group, and a carboxyl group. , a resin composition having at least one selected from the group consisting of groups having a carboxylic anhydride structure;
[2] The block copolymer (C) of an aromatic vinyl compound and an olefin has a melt flow rate of 0.1 to 100 g/10 min at 230° C. and a load of 2160 g, measured according to JIS K 7210:2014. The resin composition of [1];
[3] The resin composition of [1] or [2], wherein the block copolymer (C) of an aromatic vinyl compound and an olefin is a halogen-containing styrene-isobutylene-styrene block copolymer;
[4] The ethylene-vinyl alcohol copolymer (B) is an ethylene-vinyl alcohol copolymer (B1) having an ethylene unit content of 15 mol% or more and less than 40 mol% and an ethylene unit content of 40 mol% or more and 60 mol. % or less of the ethylene-vinyl alcohol copolymer (B2), the resin composition of any one of [1] to [3];
[5] containing a polyvalent metal compound (G) having at least one metal atom selected from the group consisting of magnesium, calcium and zinc, with respect to the content of the polyvalent metal compound (G) in the resin composition , the content of the polyvalent metal compound (G) with respect to the ethylene-vinyl alcohol copolymer (B), which is calculated by multiplying the content (% by mass) of the ethylene-vinyl alcohol copolymer (B) in the resin composition. The resin composition of any one of [1] to [4], wherein the amount is 5 to 1000 ppm;
[6] The resin composition of any one of [1] to [5], containing 0.1 to 20 parts by mass of acid-modified polyolefin (D) per 100 parts by mass of polyolefin (A);
[7] A block copolymer of an aromatic vinyl compound and an olefin (C ), the method for producing a resin composition according to any one of [1] to [6], comprising the step of melt-kneading a multilayer structure containing
[8] A multilayer structure containing a polyolefin (A) layer and the ethylene-vinyl alcohol copolymer (B) layer, and an ethylene-containing block copolymer (C) of an aromatic vinyl compound and an olefin as main components A method for producing a resin composition according to any one of [1] to [6], comprising a step of melt-kneading a vinyl alcohol copolymer recovery aid;
[9] A multilayer structure comprising a resin composition layer according to any one of [1] to [6], a polyolefin (A) layer, the ethylene-vinyl alcohol copolymer (B) layer, and an acid-modified polyolefin (D) layer ;
[10] Molded article having a resin composition layer according to any one of [1] to [6];
[11] An ethylene-vinyl alcohol copolymer recovery aid containing as a main component a block copolymer (C) of an aromatic vinyl compound and an olefin used in the resin composition of any one of [1] to [6]. agent;
[12] A self-recovery type ethylene-vinyl alcohol copolymer resin composition containing 0.1 to 30 parts by mass of the recovery aid of [11] per 100 parts by mass of the ethylene-vinyl alcohol copolymer (B); This is achieved by providing

The resin composition of the present invention can reduce the deterioration of hue and adhesion of resin such as deteriorated products to screws and dies even when melt molding is repeatedly performed, and a molded product excellent in impact resistance and appearance can be obtained. A resin composition, a method for producing the resin composition, and a multilayer structure using the resin composition can be provided. Hereinafter, in the present specification, the effect on the hue and adhesion of resin such as deteriorated products to the screw and die when melt molding is repeatedly performed may be expressed as "recoverability".

As used herein, the term "recovery" of a multilayer structure containing EVOH refers to the recycling of unnecessary parts such as trims (edges), burrs, or scraps (defective products) generated during manufacturing or molding. A process of cutting the recovered multilayer structure and melt-kneading it using an extruder is generally adopted. In addition, "recovered material" means a resin composition obtained by recovery. In the present specification, the term "EVOH recovery aid" refers to an additive intended to be added when recovering a multi-layer structure containing EVOH, and is an additive that has the effect of increasing the recoverability of EVOH. means Further, in this specification, the term "self-recovery type EVOH resin composition" means that when a multilayer structure containing an EVOH resin composition layer is melt-kneaded (recovered), the present self-recovery aid is not added. It means an EVOH resin composition that exhibits good recoverability in the resin composition of the invention.

The resin composition of the present invention is an ethylene-vinyl alcohol copolymer (B) (hereinafter referred to as 0.1 to 20 parts by mass of a block copolymer (C) of an aromatic vinyl compound and an olefin (hereinafter abbreviated as "polymer (C)") ), and the polymer (C) has at least one selected from the group consisting of groups having a halogen, epoxy group, carboxyl group, and carboxylic anhydride structure.

(PO (A))
Since the resin composition of the present invention contains PO (A), the recoverability of the resin composition of the present invention is improved. Examples of PO (A) include polypropylene; propylene-based copolymers obtained by copolymerizing propylene with α-olefins such as ethylene, 1-butene, 1-hexene, and 4-methyl-1-pentene; low-density polyethylene , linear low-density polyethylene, medium-density polyethylene, polyethylene such as high-density polyethylene; Polymer; poly(1-butene), poly(4-methyl-1-pentene) and the like. Among them, polypropylene, propylene-based copolymers, polyethylene or ethylene-based copolymers are preferable, and from the viewpoint of excellent heat resistance, polypropylene or propylene-based polymers are preferable. PO (A) may be used singly or in combination of two or more.

The melt flow rate (MFR) of PO (A) measured in accordance with JIS K 7210:2014 at 230° C. under a load of 2160 g is preferably 0.1 g/10 min or more, and preferably 0.5 g/10 min or more. more preferred. Moreover, the MFR of PO (A) is preferably 50 g/10 min or less, more preferably 10 g/10 min or less. When the MFR of PO (A) is within the above range, the recoverability tends to be good.

(EVOH (B))
EVOH (B) has an ethylene unit content of 15 to 60 mol % and a degree of saponification of 85 mol % or more. EVOH (B) can be obtained by saponifying an ethylene-vinyl ester copolymer. Vinyl esters include vinyl acetate as a typical vinyl ester, but other fatty acid vinyl esters (vinyl propionate, vinyl pivalate, etc.) can also be used.

The ethylene unit content of EVOH (B) is preferably 20 mol % or more, more preferably 23 mol % or more. The ethylene unit content of EVOH (B) is preferably 55 mol% or less, more preferably 50 mol% or less. When the ethylene unit content of EVOH (B) is less than 15 mol %, the amount of resin adhering to the screw tends to increase when the resin composition of the present invention is repeatedly melt-molded. Moreover, when the ethylene unit content exceeds 60 mol %, for example, when the resin composition of the present invention is produced by recovering and reusing a multilayer structure containing EVOH (B), the barrier of the multilayer structure as a raw material tend to decline.

The degree of saponification of the vinyl ester units of EVOH (B) is preferably 90 mol% or more, more preferably 98 mol% or more, still more preferably 99 mol% or more, and may be 100 mol%. When the degree of saponification of EVOH (B) is less than 85 mol%, the recoverability tends to deteriorate. The ethylene unit content and saponification degree of EVOH (B) can be determined by a nuclear magnetic resonance (NMR) method.

EVOH (B) may have units derived from monomers other than ethylene, vinyl esters, and saponified products thereof. When EVOH (B) has the other monomer unit, the content of the other monomer unit is preferably 30 mol% or less, more preferably 20 mol% or less, relative to the total structural units of EVOH (B). , is more preferably 10 mol % or less, and particularly preferably 5 mol % or less. Further, when EVOH (B) has units derived from the other monomers, the lower limit may be 0.05 mol % or 0.10 mol %. Examples of the other monomers include alkenes such as propylene, butylene, pentene, and hexene; diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diacyloxy-2- methyl-1-butene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6- Alkenes having an ester group such as acyloxy-1-hexene, 5,6-diacyloxy-1-hexene, 1,3-diacetoxy-2-methylenepropane, or saponified products thereof; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, etc. unsaturated acids or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefins such as vinylsulfonic acid, allylsulfonic acid, and methallylsulfonic acid Sulfonic acid or its salt; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxy-ethoxy)silane, γ-methacryloxypropylmethoxysilane, etc. Vinylsilane compounds; alkyl vinyl ethers, vinyl ketone, N-vinylpyrrolidone, vinyl chloride , vinylidene chloride and the like.

EVOH (B) may be post-modified by methods such as urethanization, acetalization, cyanoethylation, and oxyalkylenation.

The MFR of EVOH (B) measured in accordance with JIS K 7210:2014 at 230° 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. Also, the MFR of EVOH (B) is preferably 100 g/10 min or less, more preferably 50 g/10 min or less, even more preferably 30 g/10 min or less. When the MFR of EVOH (B) is within the above range, the recoverability of the resin composition of the present invention tends to be good.

The content of EVOH (B) in the resin composition of the present invention is 0.1 parts by mass or more, preferably 1 part by mass or more, per 100 parts by mass of PO (A). When the content of EVOH (B) is less than 0.1 parts by mass, the problem of recoverability is less likely to occur when the resin composition of the present invention is repeatedly melt-molded, and by adding the polymer (C) The influence of the effect played becomes small. The content of EVOH (B) is 20 parts by mass or less, preferably 15 parts by mass or less, relative to 100 parts by mass of PO (A). If the content of EVOH (B) is more than 20 parts by mass, when the resin composition of the present invention is repeatedly melt-molded, the recoverability deteriorates, and the impact resistance of the resulting molded article decreases.

EVOH (B) may be used singly or in combination of two or more. When two or more types of EVOH (B) are used in combination, an ethylene-vinyl alcohol copolymer (B1) having an ethylene unit content of 15 mol% or more and less than 40 mol% (hereinafter sometimes abbreviated as "EVOH (B1)") ) and an ethylene unit content of 40 mol% or more and 60 mol% or less ethylene-vinyl alcohol copolymer (B2) (hereinafter sometimes abbreviated as "EVOH (B2)"). It is preferable from the viewpoint of improving the recoverability and impact resistance of the resin composition, and when the resin composition of the present invention is produced by recovering a multilayer structure containing EVOH (B), the gas barrier of the multilayer structure as a raw material It tends to be possible to improve the recoverability and impact resistance of the resin composition of the present invention while maintaining good properties. The ethylene unit content of EVOH (B1) is preferably 20 mol% or more, more preferably 23 mol% or more. The ethylene unit content of EVOH (B1) is preferably 37 mol % or less, more preferably 35 mol % or less. The ethylene unit content of EVOH (B2) is preferably 55 mol% or less, more preferably 50 mol% or less. The preferred ranges of the degree of saponification and MFR of EVOH (B1) and EVOH (B2) are the same as the preferred ranges of EVOH (B) described above.

(Block copolymer (C) of aromatic vinyl compound and olefin)
Polymer (C) is a block copolymer containing an aromatic vinyl compound and an olefin as monomer units, and is selected from the group consisting of a group having a structure of halogen, epoxy group, carboxyl group, or carboxylic acid anhydride. It has at least one selected. By containing the polymer (C), the resin composition of the present invention tends to obtain a resin composition that provides good recoverability and gives molded articles that are excellent in impact resistance and appearance. . The polymer (C) is preferably a block copolymer having a polymer block (b1) composed of aromatic vinyl compound units and a polymer block (b2) composed of olefin units. The polymer (C) preferably has at least one polymer block (b1) and at least one polymer block (b2) in its molecule, and its structure is not particularly limited. For example, the block copolymer may have a linear molecular chain, a branched chain having two or more branches, or a star-shaped molecular chain. The block structure used as the polymer (C) is, for example, a diblock structure represented by b1-b2, a triblock structure represented by b1-b2-b1 or b2-b1-b2, b1-b2-b1-b2 A tetrablock structure represented by , a polyblock structure in which a total of 5 or more b1 and b2 are bonded in a straight chain, or a mixture thereof.

The aromatic vinyl compound unit, which is a structural unit of the polymer block (b1), is a unit derived from an aromatic vinyl compound by addition polymerization. Examples of aromatic vinyl compounds include styrenes such as styrene, α-methylstyrene, 2-methylstyrene and 4-methylstyrene; vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene. Among them, the aromatic vinyl compound is preferably styrenes, more preferably styrene. The number of aromatic vinyl compound units constituting the polymer block (b1) may be one or two or more. The polymer block (b1) preferably consists of styrene units.

The lower limit of the number average molecular weight of the polymer block (b1) is preferably 1,000, more preferably 2,000, from the viewpoint of improving the mechanical properties of the resulting resin composition. On the other hand, the upper limit of the number average molecular weight of the polymer block (b1) is preferably 400,000, more preferably 200,000.

The olefin unit, which is a structural unit of the polymer block (b2), is a unit derived from an olefin by addition polymerization. Olefins include, for example, ethylene, propylene, butylene, isobutylene, and the like. Among them, the olefin is preferably isobutylene. The number of olefin units constituting the polymer block (b2) may be one, or two or more. The polymer block (b2) preferably consists of isobutylene units.

The number average molecular weight of the polymer block (b2) is preferably 10,000 or more, and preferably 400,000 or less.

When the polymer (C) has the polymer block (b1) and the polymer block (b2), the proportion thereof may be appropriately determined, but the content of the polymer block (b1) in the block copolymer The lower limit of the amount is preferably 5% by mass, more preferably 10% by mass, and still more preferably 15% by mass relative to the total mass of polymer (C). When the content of the polymer block (b1) is at least the above lower limit, the recoverability of the resin composition of the present invention tends to be good. On the other hand, the upper limit of the content of the polymer block (b1) is preferably 80% by mass, more preferably 70% by mass, and even more preferably 50% by mass relative to the total mass of the polymer (C). When the content of the polymer block (b1) is equal to or less than the above upper limit, the impact resistance of the resin composition of the present invention tends to be improved. In addition, when the polymer (C) contains a plurality of polymer blocks (b1), the total amount thereof is defined as the content of the polymer block (b1).

As the polymer (C), it is sufficient that the polymer (C) has at least one selected from the group consisting of groups having a structure of halogen, epoxy group, carboxyl group, and carboxylic acid anhydride. Examples of the resin include styrene-ethylenebutylene-styrene block copolymer (SEBS), styrene-ethylenepropylene-styrene block copolymer (SEPS), styrene-isobutylene-styrene block copolymer (SIBS), and the like. Among them, from the viewpoint of excellent thermal stability and recoverability, a styrene-isobutylene-styrene block copolymer having at least one selected from the group consisting of groups having a halogen, epoxy group, carboxyl group, and carboxylic anhydride structure Polymers (SIBS) are preferred, and SIBS with halogens are more preferably used.

The polymer (C) in the resin composition of the present invention contains at least one selected from the group consisting of groups having a halogen, epoxy group, carboxyl group, and carboxylic anhydride structure. The compatibility of the resin composition of the present invention tends to be improved, and the recoverability of the resin composition of the present invention tends to be improved. Among them, it is preferable to have a halogen from the viewpoint of further improving the recoverability of the resin composition of the present invention. The means for introducing a halogen, epoxy group, carboxyl group, or carboxylic anhydride structure into the polymer (C) is not particularly limited. It may be introduced as a group derived from an initiator, or may be introduced by post-modification. Other functional groups may be introduced into the polymer (C) by any method. Examples of functional groups that can be introduced include ether groups such as hydroxyl groups, amino groups, alkylamino groups and alkoxyl groups, ester groups such as alkoxycarbonyl groups and acyloxyl groups, and amide groups such as carbamoyl groups, alkylcarbamoyl groups and acylamino groups. etc.

The content of at least one functional group selected from the group consisting of groups having a structure of halogen, epoxy group, carboxyl group and carboxylic anhydride in the polymer (C) affects the recoverability of the resin composition of the present invention. It is preferably 0.005 to 3.00% by mass, more preferably 0.01 to 1.5% by mass, from the viewpoint of further increasing the content.

The lower limit of the number average molecular weight of the polymer (C) is preferably 12,000, more preferably 30,000. On the other hand, the upper limit of the number average molecular weight of the polymer (C) is preferably 600,000, more preferably 400,000.

The lower limit of the MFR of the polymer (C) measured in accordance with JISK7210 :2014 at 230°C under a load of 2160g is preferably 0.1g/10min, more preferably 1.0g/10min. 4.0 g/10 min is more preferred, and 8.0 g/10 min is particularly preferred. On the other hand, the upper limit of the MFR of the polymer (C) is preferably 100 g/10 minutes, more preferably 50 g/10 minutes, even more preferably 30 g/10 minutes. When the MFR is within the above range, the recoverability of the obtained resin composition tends to be improved.

The refractive index of the polymer (C) is preferably 1.50 or more, more preferably 1.52 or more, and may be 1.58 or less or 1.55 or less. When the refractive index of the polymer (C) is within the above range, the difference in refractive index from EVOH (B) is small. When it is used for production, the transparency of the multilayer structure as a raw material tends to be good. In order to keep the refractive index within the above range, it is preferable that the content of the polymer block (b1) is 15% by mass or more and the polymer block (b2) is isobutylene. The refractive index of the polymer (C) can be measured according to JIS K7142:2014, specifically using an Abbe refractometer.

The content of the polymer (C) in the resin composition is 0.1 parts by mass or more, preferably 0.3 parts by mass or more, and more than 0.7 parts by mass based on 100 parts by mass of PO (A). more preferred. If the content of the polymer (C) is less than 0.1 parts by mass, the recoverability of the resin composition of the present invention is significantly deteriorated, and the impact resistance is deteriorated. The content of the polymer (C) is 10 parts by mass or less, preferably 8 parts by mass or less, per 100 parts by mass of PO (A). If the content of the polymer (C) exceeds 10 parts by mass, the hue and adhesion of deteriorated substances to the screw tend to deteriorate when the resin composition of the present invention is repeatedly melt-molded. A polymer (C) can also be used individually and can also be used in mixture of 2 or more types.

From the viewpoint of suppressing gelation and adhesion to the screw during repeated melt molding, the resin composition of the present invention is a polyvalent metal compound having at least one metal atom selected from the group consisting of magnesium, calcium and zinc. (G) is preferably included. The metal atom of the polyvalent metal compound (G) more preferably contains magnesium or calcium, and more preferably contains magnesium.

Polyvalent metal compound (G) is preferably a hydroxide salt or a carboxylate. As the carboxylic acid constituting the carboxylic acid salt, an aliphatic carboxylic acid or an aromatic carboxylic acid is preferable, and an aliphatic carboxylic acid is more preferable. Aliphatic carboxylic acids include higher aliphatic carboxylic acids having 5 or more carbon atoms and lower aliphatic carboxylic acids having 4 or less carbon atoms. The number of carbon atoms in the carboxylate is preferably 1 to 20, more preferably 10 or less, still more preferably 5 or less, and particularly preferably 3 or less. Examples of aliphatic carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, myristic acid, behenic acid, and montanic acid, with acetic acid being preferred.

When the resin composition of the present invention contains a polyvalent metal compound (G), the content of EVOH (B) in the resin composition ( The content of the polyvalent metal compound (G) with respect to EVOH (B) calculated by multiplying EVOH (B) is preferably 5 ppm or more, more preferably 20 ppm or more, still more preferably 40 ppm or more, and particularly preferably 70 ppm or more. When the content of the polyvalent metal compound (G) relative to EVOH (B) is 5 ppm or more, when the resin composition of the present invention is repeatedly melt-molded, gelation of the resin and adhesion to the screw in the extruder are suppressed. tend to be Also, the content of the polyvalent metal compound (G) with respect to EVOH (B) is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 300 ppm or less, and particularly preferably 150 ppm or less. When the content of the polyvalent metal compound (G) relative to EVOH (B) is 1000 ppm or less, the resin composition of the present invention tends to have a good hue when melt-molded repeatedly. An example of the method for calculating the content of the polyvalent metal compound (G) with respect to the EVOH (B) in the present specification is, for example, that the polyvalent metal compound (G) in the resin composition is 500 ppm, and the EVOH (B) is 10% by mass, the content of the polyvalent metal compound (G) with respect to EVOH (B) is 50 ppm.

When the polyvalent metal compound (G) is a lower aliphatic carboxylic acid metal salt, the content of EVOH (B) in the resin composition relative to the content of the lower aliphatic carboxylic acid metal salt in the resin composition ( The content of the lower aliphatic carboxylic acid metal salt relative to EVOH (B), which is calculated by multiplying EVOH (% by mass), is preferably 5 ppm or more, more preferably 20 ppm or more. Also, the content of the lower aliphatic carboxylic acid metal salt is preferably 500 ppm or less, more preferably 150 ppm or less. Further, when the polyvalent metal compound (G) is a higher aliphatic carboxylic acid metal salt, the content of EVOH (B) in the resin composition relative to the content of the higher aliphatic carboxylic acid metal salt in the resin composition The content of the higher aliphatic carboxylic acid metal salt relative to EVOH (B), which is calculated by multiplying the ratio (% by mass), is preferably 20 ppm or more, more preferably 100 ppm or more. Also, the content of the higher aliphatic carboxylic acid metal salt is preferably 1000 ppm or less, more preferably 500 ppm or less. When the content of the lower aliphatic carboxylic acid metal salt or the higher aliphatic carboxylic acid metal salt is within the above range, the recoverability tends to be good. The polyvalent metal compound (G) may be used singly or in combination of two or more.

The resin composition of the present invention may contain an acid-modified polyolefin (D) (hereinafter sometimes abbreviated as "acid-modified PO (D)"). By containing a specific amount of acid-modified PO (D) in the resin composition of the present invention, the compatibility of PO (A) and EVOH (B) is improved, and when repeatedly melt-molded, deterioration of screws and dies occurs. It tends to be possible to reduce adhesion of resin such as objects, and tends to improve impact resistance. In addition, a layer containing PO (A) as a main component (hereinafter sometimes abbreviated as "PO (A) layer") and a layer containing EVOH (B) as a main component (hereinafter abbreviated as "EVOH (B) layer") In order to increase the interlayer adhesion between the PO (A) layer and the EVOH (B) layer, a layer containing acid-modified PO (D) as a main component (hereinafter referred to as "acid-modified PO (D) layer (sometimes abbreviated as "layer") is often provided as an adhesive layer. When a multilayer structure having an acid-modified PO(D) layer is efficiently recovered and melt-molded, the obtained resin composition will contain the acid-modified PO(D). Therefore, when a multilayer structure comprising a PO (A) layer and an EVOH (B) layer is recovered to produce a resin composition of the present invention, there is a tendency to obtain a resin composition containing acid-modified PO (D). becomes. Here, "main component" means more than 50% by mass, and the ratio of PO (A), EVOH (B) or acid-modified PO (D) occupying each layer in the multilayer structure is 70% by mass. It is preferably 90% by mass or more, more preferably 90% by mass or more, and may be 100% by mass.

Examples of the acid-modified PO (D) include graft-modified PO obtained by graft-modifying PO with an acid, and acid-modified olefin-based copolymers obtained by copolymerizing an olefin and an acid. Among them, graft-modified PO is preferable as the acid-modified PO (D). From the viewpoint of excellent compatibility with PO (A), the acid-modified PO (D) is preferably acid-modified polyolefin of the same type as PO (A). For example, when PO (A) is polypropylene, acid-modified PO (D) is preferably acid-modified polypropylene, and when PO (A) is polyethylene, acid-modified PO (D) is acid Modified polyethylene is preferred.

Examples of the graft-modified PO used as the acid-modified PO (D) include those obtained by graft-modifying the PO exemplified as the PO (A) described above with an acid. As the acid to be grafted onto PO, an unsaturated carboxylic acid or a derivative thereof can be used, and examples thereof include acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid; maleic anhydride, itaconic anhydride, and the like. . Of these, maleic anhydride graft-modified PO is most preferred.

Examples of the olefinic copolymer used as the acid-modified PO (D) include those obtained by adding an acid as a copolymerization component to the PO used as the PO (A) described above. Examples of the acid used at this time include those exemplified as the acid to be grafted onto the PO.

The acid value of the acid-modified PO (D) is preferably 0.1 mgKOH/g or more, more preferably 0.5 mgKOH/g or more. When the acid-modified PO (D) has an acid value of 0.1 mgKOH/g or more, the resulting resin composition tends to have good recoverability. When a multilayer structure comprising an acid-modified PO (D) layer between the (B) layer is recovered and produced, the interlayer adhesion between the PO (A) layer and the EVOH (B) layer tends to be good. Become. The acid value of acid-modified PO (D) is preferably 9 mgKOH/g or less, more preferably 7 mgKOH/g or less, still more preferably 5 mgKOH/g or less, and particularly preferably 3 mgKOH/g or less. When the acid value of the acid-modified PO (D) is 9 mgKOH/g or less, the resin composition of the present invention is used to form a multilayer having the acid-modified PO (D) layer between the PO (A) layer and the EVOH (B) layer. When the structure is collected and manufactured, it tends to be easier to prepare the layer thickness of the multilayer structure before collection to be uniform. The acid-modified PO (D) may be used singly or in combination of two or more. When two or more acid-modified PO (D) are used, the acid values of the respective resins are weighted and averaged by the mixture mass ratio. The value is taken as the acid value of acid-modified PO(D). The acid value of acid-modified polyolefin can be measured according to JIS K 0070:1992 using xylene as a solvent.

The acid-modified PO (D) preferably has an MFR of 0.1 to 100 g/10 min at 190° C. under a load of 2160 g, measured according to JIS K 7210:2014. When a multilayer structure comprising a PO (A) layer, an EVOH (B) layer and an acid-modified PO (D) layer is recovered to produce the resin composition of the present invention, the MFR of the acid-modified PO (D) is Within the range, the viscosity balance of PO (A), polymer (C) and PO (D) tends to be good, the dispersibility of EVOH (B) is improved, and the resulting resin composition This tends to improve the impact resistance.

The content of the acid-modified PO (D) in the resin composition of the present invention is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and 2 parts by mass with respect to 100 parts by mass of PO (A). Part or more is more preferable. Also, the content of the acid-modified PO (D) is preferably 20 parts by mass or less, more preferably 17 parts by mass or less. When the acid-modified PO (D) is within the above range, the recoverability tends to be good.

The resin composition of the present invention contains PO (A), EVOH (B), polymer (C), acid-modified PO (D) and polyvalent metal compound (G) other than PO (A), EVOH (B), polymer (C), and polyvalent metal compound (G), as long as the effects of the present invention are not impaired. may contain additives. Examples of the additives include PO (A), EVOH (B), resins other than the polymer (C) and acid-modified PO (D), antioxidants, UV absorbers, plasticizers, lubricants, fillers, Antistatic agents may be mentioned. Specific examples of additives include the following. The content of other additives in the resin composition is usually 50% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

Resins other than PO (A), EVOH (B), polymer (C) and acid-modified PO (D) include polyamide, polyvinyl chloride, polyvinylidene chloride, polyester, polystyrene, epoxy resin, acrylic resin, and urethane resin. , polyester resins, and the like.

Antioxidants include 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 ) and the like.

UV absorbers include 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.

Examples of plasticizers include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate.

Lubricants include stearamide, oleamide, erucamide, behenic acid amide, ethylene bis stearamide, methylol stearamide, N-oleyl palmitamide, N-stearyl erucamide, liquid paraffin, natural paraffin, Synthetic paraffin, polyolefin wax, stearyl alcohol, lauryl alcohol, stearic acid, lauric acid, myristic acid, behenic acid, montanic acid, stearyl stearate, stearyl laurate, calcium stearate, magnesium stearate, zinc stearate, lead stearate, etc. is mentioned.

Fillers include glass fiber, asbestos, ballastonite, calcium silicate and the like.

Examples of antistatic agents include glycerin monofatty acid esters, fatty acid diethanolamides, alkyldiethanolamines, alkylsulfonates, alkylbenzenesulfonates, alkyltrimethylammonium salts, alkylbenzyldimethylammonium salts, alkylbetaines, alkylimidazoliumbetaines, and the like. .

The ratio of PO (A), EVOH (B) and polymer (C) in the resin composition of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. 90% by mass or more is particularly preferable, and it may be 95% by mass or more or 100% by mass. Further, when the resin composition of the present invention contains acid-modified PO (D), PO (A), EVOH (B), polymer (C) and acid-modified PO (D) in the resin composition of the present invention account for The ratio is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 95% by mass or more or 100% by mass. .

(Method for producing resin composition)
The method for producing the resin composition of the present invention is not particularly limited. A method of melt-kneading a multilayer structure comprising the (B) layer and an EVOH recovery aid containing the polymer (C) as a main component; A method of melt-kneading a multilayer structure containing the polymer (C) in one layer, and the like can be mentioned. Further, when the resin composition of the present invention contains PO(D), even if PO(D) is contained in the above-described dry blending process, the PO(D) layer is contained as an adhesive layer in the multilayer structure. You can let Further, when the resin composition of the present invention contains the above-described other components, the other components may be mixed in the above-described dry blending process, or may be included in the layers constituting the multilayer structure. may be added during melt-kneading. Among them, a step of melt kneading a multilayer structure comprising a PO (A) layer and an EVOH (B) layer and a polymer (C), or a multilayer structure comprising a PO (A) layer and an EVOH (B) layer It is preferable to include a step of melt-kneading a multilayer structure containing the polymer (C) in at least one layer constituting .

When the method for producing the resin composition of the present invention includes the step of recovering the multilayer structure comprising the PO (A) layer and the EVOH (B) layer, the polymer (C) functions as an EVOH recovery aid. The EVOH recovery aid of the present invention contains polymer (C) as a main component. Here, the "main component" means more than 50% by mass, and the proportion of the polymer (C) in the EVOH recovery aid of the present invention is preferably 60% by mass or more, and preferably 70% by mass or more. is more preferable, and may be 90% by mass or more, 95% by mass or more, or 100% by mass.

When the resin composition of the present invention comprises a step of melt kneading a multilayer structure in which at least one layer constituting a multilayer structure comprising a PO (A) layer and an EVOH (B) layer contains the polymer (C), It is preferable that the polymer (C) is contained in the EVOH (B) layer from the viewpoint that the layer structure of the multilayer structure can be freely selected. When the polymer (C) is contained in the EVOH (B) layer, a self-recovery EVOH resin composition containing 0.1 to 30 parts by mass of the polymer (C) with respect to 100 parts by mass of the EVOH (B). from the viewpoint of transparency of the multilayer structure used as the raw material. When the multilayer structure containing the self-collecting EVOH resin composition is melt-kneaded, there is no need for a step of adding a new collection aid, so collection tends to be easy. EVOH (B) and polymer (C) tend to have a smaller refractive index difference, and a self-recovery EVOH resin composition containing EVOH (B) and polymer (C) tends to have higher transparency. On the other hand, resin compositions containing EVOH (B) and conventional recovery aids tend to have low transparency. That is, the self-recovery type EVOH resin composition used in one aspect of the production of the resin composition of the present invention can maintain high transparency in the multilayer structure before recovery, and a new recovery aid is added at the time of recovery. It can be said that it is an excellent resin composition that can exhibit high recoverability without any defects.

The self-recovery EVOH resin composition of the present invention preferably contains 0.5 parts by mass or more, more preferably 1 part by mass or more, of polymer (C) based on 100 parts by mass of EVOH (B). In addition, the polymer (C) is preferably contained in an amount of 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 6 parts by mass or less, and may be composed of 4 parts by mass or less. When the content of the polymer (C) in the self-recovery type EVOH resin composition of the present invention is within the above range, the recoverability tends to be good.

The ratio of EVOH (B) and polymer (C) in the self-recovery EVOH resin composition of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass, from the viewpoint of barrier properties. % or more is more preferable, 95 mass % or more is particularly preferable, and it may be 98 mass % or more, or 100 mass %.

The resin composition of the present invention may use only unused resin as a raw material, but using the recovered multilayer structure as described above as at least a part of the raw material is effective in reducing the amount of waste. and from the viewpoint of cost reduction. The ratio of the recovered material in the raw material of the resin composition of the present invention is preferably 50% by mass or more. As long as it does not impair the effects of the present invention, packaging materials (multilayer structures) consumed on the market may be used as the raw material for the recovered material. A step of separating and washing the mixture by using an extruder is generally employed.

The multilayer structure used as a raw material for the resin composition of the present invention is not particularly limited, and examples thereof include multilayer structures having the following layer structures. In the following examples, the PO (A) layer is "A", the EVOH (B) layer is "B", the acid-modified PO (D) layer is "D", the resin composition layer of the present invention is "E", and the direct "/" is used to indicate that the layers are stacked. In addition, it is preferable that at least one layer of the multilayer structure described below contains the polymer (C).
3 layers A/D/B, A/B/A
5 layers A/D/B/D/A, A/D/B/D/E
6 layers A/D/B/D/E/A, E/A/D/B/D/A, A/E/D/B/D/E, E/A/D/B/D/E
7 layers A/E/D/B/D/E/A, A/E/D/B/D/A/E, E/A/D/B/D/A/E

It is preferable that the multilayer structure has a resin composition layer of the present invention from the viewpoint of reducing the amount of waste and cost. Moreover, from the viewpoint of improving the adhesion between the layers, it is preferable that the EVOH (B) layer and the acid-modified PO (D) layer are in contact with each other.

The overall thickness of the multilayer structure can be appropriately set according to the application. The overall thickness is preferably 50-8000 μm. When the total thickness is 50 μm or more, a highly rigid multilayer structure can be obtained. More preferably, the total thickness is 500 μm or more. On the other hand, when the total thickness is 8000 μm or less, a flexible multilayer structure can be obtained. More preferably, the total thickness is 7000 μm or less.

The method for manufacturing the multilayer structure is not particularly limited. For example, molding methods practiced in the field of general polyolefins, such as extrusion molding, blow molding, injection molding, thermoforming and the like can be mentioned. Among them, co-extrusion molding and coinjection molding are preferable, and co-extrusion molding is more preferable.

(multilayer structure)
The multilayer structure of the present invention is a multilayer structure comprising the resin composition layer of the present invention, a PO (A) layer, an EVOH (B) layer and an acid-modified PO (D) layer. Suitable layer structures and production methods for the multilayer structure of the present invention include those described as examples of the multilayer structure used as the raw material described above, which has the resin composition layer of the present invention. Further, the multilayer structure of the present invention may have resin layers other than the PO (A) layer, the EVOH (B) layer and the acid-modified PO (D) layer as long as the effect of the present invention is not impaired. good. Examples of the other resin layers include an ethylene-vinyl acetate copolymer layer, a polyester layer such as polyethylene terephthalate, a polyester elastomer layer, a polyamide layer such as nylon-6 and nylon-66, a polystyrene layer, a polyvinyl chloride layer, and a polyvinyl chloride layer. A vinylidene layer, an acrylic resin layer, a vinyl ester resin layer, a polyurethane layer, a polycarbonate layer, and the like can be mentioned.

(Molding)
Molded articles containing the resin composition of the present invention have a small amount of deteriorated substances adhering to screws and dies even when melt molding is continuously performed for a long period of time. Furthermore, by using the resin composition, a molded article having excellent impact resistance and appearance can be obtained. The molded article can be suitably used as a material for various packaging containers such as food packaging containers, pharmaceutical packaging containers, industrial chemical packaging containers, and agricultural chemical packaging containers.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

<Evaluation method>
(1) Melt flow rate (MFR)
For the resins used in Examples and Comparative Examples, the outflow rate (g/10min) of the sample was measured using a melt indexer in accordance with JIS K 7210:2014 under conditions of a temperature of 230°C and a load of 2160g.

(2) Collectability evaluation (die build-up, screw build-up, hue of collected composition)
6000 g of the resin composition pellets obtained in Examples and Comparative Examples were melt-kneaded under the following conditions to produce resin composition pellets again, which was repeated four times. Fifteen minutes after the start of the fourth melt-kneading, the adhered resin accumulated on the die was sampled and weighed, and the total measured value was taken as the die build-up amount. Next, after purging with 1 kg of high-density polyethylene, the screw was removed and the deposited resin accumulated on the screw was sampled and weighed to determine the amount of screw buildup (gelled resin). In addition, the YI (yellow index) value of the resin composition pellets (recovered product) obtained after the fourth melt-kneading was measured using a HunterLab spectrophotometer "LabScan XE Sensor". The amount of die buildup is an index of the compatibility of the components in the resin composition. The smaller the amount of die buildup, the better the compatibility and the less likely problems caused by insufficient compatibility will occur. The screw buildup is an index of the viscosity stability of the components in the resin composition, and the smaller the screw buildup, the better the viscosity stability. Also, the YI value is an index representing the degree of yellowness (yellowness) of an object.
Extruder: Twin-screw segment extruder (2D30W2) manufactured by Toyo Seiki Seisakusho Co., Ltd.
Screw diameter: 25 mmφ, L/D = 30
Screw rotation speed: 100 rpm
Cylinder and die temperature settings: C1/C2/C3/C4/C5/D=180/200/230/230/230/230°C
Discharge speed: 6 kg/hour

(3) Impact strength and appearance evaluation of single-layer film The resin composition pellets after the fourth melt-kneading obtained in the above recoverability evaluation are processed by a 20 mm extruder "D2020" manufactured by Toyo Seiki Seisakusho Co., Ltd. (D (mm ) = 20, L/D = 20, compression ratio = 3.5, screw: full flight), single-layer film formation was performed under the following conditions to obtain a single-layer film.
(Extrusion conditions)
Cylinder temperature: supply part 190°C, compression part 230°C, metering part 230°C
Die temperature: 230°C
Screw rotation speed: 40 rpm
Take-up roll temperature: 80°C
Film thickness: 50 μm
(Impact strength measurement)
The impact strength was measured using a film impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) using the obtained 50 μm single-layer film.
(Appearance evaluation of film)
Also, the appearance of the obtained 50 μm monolayer film was evaluated according to the following criteria.
A: No abnormality was observed on the film.
B: A streak was observed on the film.
C: A streak and a significant decrease in transparency were observed on the film.

(4) Transparency evaluation For the single-layer films with a thickness of 20 μm obtained in Examples and Comparative Examples, a Poik integrating sphere type light transmittance/total light reflectance meter (manufactured by Murakami Color Research Laboratory) was measured according to JIS K7375. HR-100 type") was used to measure the haze.

(5) Evaluation of gas barrier property The 20 μm-thick single-layer films obtained in Examples and Comparative Examples were subjected to humidity conditioning for 7 days at 20° C. and 65% RH, and then subjected to JIS K 7126-2 (isobaric method). , 20° C. and 65% RH (“OX-TORAN MODEL 2/21” manufactured by Mocon).

Synthesis example 1
[Production of block copolymer C-1 of aromatic vinyl compound and olefin]
A mixed solvent consisting of methylene chloride and methylcyclohexene, and a polymerization initiator consisting of titanium tetrachloride and 1,4-bis(1-methoxy-1-methylethyl)benzene were placed in a nitrogen-substituted reactor equipped with a stirrer. was charged and cooled to −65° C., then isobutylene was charged and polymerized for 4 hours. Further, dimethylacetamide and styrene were added under cooling at -65°C and polymerized for 4 hours. The resulting reaction mixture was precipitated with methanol to produce a styrene-isobutylene-styrene block copolymer having a styrene content of 20%, a halogen content of 1.0% and an MFR of 10 g/10 min (230° C., load of 2160 g). Each charge amount was adjusted so as to obtain the above physical properties. The MFR of the resulting polymer (C-1) was determined according to JIS K 7210:2014 using a melt indexer under the conditions of a temperature of 230° C. and a load of 2160 g. . The content of polymer blocks composed of styrene units in the block copolymer was determined by ¹ H-NMR. Halogen content is obtained by pre-treating the obtained polymer with a combustion / absorption device (AQF-2100H manufactured by Mitsubishi Analytic Co., Ltd.), and using an ion chromatograph (ICS-2000 manufactured by Nippon Dionex). It was measured.

Synthesis Examples 2, 3, 4
[Production of Block Copolymers C-2, C-3 and C-4 of Aromatic Vinyl Compound and Olefin]
The same method as in Synthesis Example 1 was used, except that the charging ratio of styrene, isobutylene and 1,4-bis(1-methoxy-1-methylethyl)benzene was changed so that the physical properties described below were obtained. Polymers (C-2) to (C-4) were produced respectively.

<Compounds used in Examples and Comparative Examples>
PO (A)
・ A-1: Novatec (trademark) PP EA7AD (manufactured by Nippon Polypropylene Co., Ltd., polypropylene, MFR 1.4 g / 10 minutes (230 ° C., load 2160 g))
EVOH (B)
・B1-1: Ethylene unit content 27 mol%, degree of saponification 99.9 mol%, MFR 8.0 g/10 min (230 ° C., load 2160 g) ethylene-vinyl alcohol copolymer ・B2-1: ethylene unit Ethylene-vinyl alcohol copolymer having a content of 44 mol%, a degree of saponification of 99.9 mol%, and an MFR of 23 g/10 min (230°C, load of 2160 g) Block copolymer (C) of an aromatic vinyl compound and an olefin
・C-1: Styrene content 20% by mass, halogen content 1.0% by mass, MFR 10 g/10 min (230 ° C., load 2160 g) styrene-isobutylene-styrene block copolymer ・C-2: Styrene content 20% by mass, 1.5% by mass of halogen content, MFR 20 g/10 min (230° C., load 2160 g) styrene-isobutylene-styrene block copolymer C-3: styrene content of 20% by mass, halogen content of 0 .7 mass%, MFR 5g/10 min (230°C, load 2160g) styrene-isobutylene-styrene block copolymer C-4: styrene content 20 mass%, halogen content 0.5 mass%, MFR 0.6g / 10 minutes (230 ° C., load 2160 g) styrene-isobutylene-styrene block copolymer C-5: Tuftec (trademark) M1913 (manufactured by Asahi Kasei Corporation, maleic anhydride-modified styrene-ethylene-butylene-styrene block copolymer coalescence, styrene content 30% by mass, maleic anhydride 1.8% by mass, MFR 5g/10min (230°C, load 2160g))
・ C-6: Tuftec (trademark) H1041 (manufactured by Asahi Kasei Corporation, styrene-ethylene-butylene-styrene block copolymer, styrene content 30% by mass, MFR 5 g / 10 minutes (230 ° C., load 2160 g))
Acid-modified polyolefin (D)
・ D-1: Admer (trademark) QF500 (manufactured by Mitsui Chemicals, Inc., acid-modified polypropylene, MFR 3.0 g / 10 minutes (230 ° C., load 2160 g), acid value 1.0 mg KOH / g))
Polyvalent metal compound (G)
・ G-1: Magnesium hydroxide ・ G-2: Magnesium acetate

[Example 1]
PO (A-1) (Novatec (trademark) EA7AD), EVOH (B1-1) (ethylene unit content 27 mol% EVOH) and copolymer (C-1) at a mass ratio (C/B/A) Dry blending was performed so that the ratio was 1/10/100, and resin composition pellets were produced using a twin-screw extruder under the following melt-kneading conditions. The obtained resin composition pellets were evaluated for recoverability and impact strength and appearance of the single layer film according to the evaluation methods (2) and (3) above. Table 1 shows the results.
<Pellet preparation conditions>
Extruder: Twin-screw segment extruder (2D30W2) manufactured by Toyo Seiki Seisakusho Co., Ltd. Screw diameter: 25 mmφ, L / D = 30
Screw rotation speed: 100 rpm
Cylinder and die temperature settings: C1/C2/C3/C4/C5/D=180/200/230/230/230/230°C
Discharge speed: 6 kg/hour

[Examples 2 to 14, Comparative Examples 1 to 3, 5]
The types of PO (A), EVOH (B1), EVOH (B2), polymer (C), acid-modified polyolefin (D) and polyvalent metal compound (G) and the mass ratio of each component are as shown in Table 1. Resin composition pellets were produced and evaluated in the same manner as in Example 1, except that it was changed to . The EVOH (B2), the acid-modified polyolefin (D) and the polyvalent metal compound (G) were included in the resin composition by dry blending before melt-kneading using a twin-screw extruder. Table 1 shows the results.

[Example 15]
Using PO (A-1) (Novatec (trademark) EA7AD), EVOH (B1-1) (ethylene unit content 27 mol% EVOH) and acid-modified PO (D-1) (Admer (trademark) QF500), Multilayer film [layer structure: PO (A-1) / acid-modified PO (D-1) / EVOH (B1-1) / acid-modified PO (D-1) / PO (A-1), thickness (μm): 80/8/16/8/80]. The obtained multilayer film was pulverized with a pulverizer to obtain a recovered product. The obtained recovered product is dry blended with the copolymer (C-1) as a recovery aid so that the mass ratio (C/A) is 1/100, and the dry blended product is used as a resin composition pellet, According to the evaluation methods (2) and (3) above, the recoverability evaluation and the impact strength and appearance evaluation of the single layer film were performed. Table 1 shows the results.

<Preparation conditions for multilayer film>
・PO (A-1)
Extruder: 32 mmφ extruder GT-32-A (manufactured by Plastic Engineering Laboratory Co., Ltd.)
Extrusion temperature: feeding section/compression section/measuring section/die = 170/230/230/230°C
Die: 300 mm wide coat hanger die (manufactured by Plastic Engineering Laboratory Co., Ltd.)
・EVOH (B1-1)
Extruder: 20 mmφ extruder Lab machine ME type CO-EXT (manufactured by Toyo Seiki Seisakusho Co., Ltd.)
Extrusion temperature: feeding section/compression section/measuring section/die = 180/210/220/230°C
Die: 300 mm wide coat hanger die (manufactured by Plastic Engineering Laboratory Co., Ltd.)
・ Acid-modified polyolefin (D-1)
Extruder: 20 mmφ extruder SZW20GT-20MG-STD (manufactured by Technobell Co., Ltd.)
Extrusion temperature: feeding section/compression section/measuring section/die = 170/230/230/230°C
Die: 300 mm wide coat hanger die (manufactured by Plastic Engineering Laboratory Co., Ltd.)

[Example 16]
EVOH (B1-1) (ethylene unit content 27 mol% EVOH) and copolymer (C-1) were extruded using a twin-screw extruder so that the mass ratio (C/B) was 5/95. Melt blending was performed under kneading conditions to obtain mixture pellets. A multilayer film [layer structure: PO (A-1)/acid-modified PO (D-1)/mixture /acid-modified PO (D-1)/PO (A-1), thickness (μm): 80/8/17/8/80]. The obtained multilayer film was pulverized with a pulverizer to obtain a recovered material. Using the obtained recovered product as a resin composition pellet, the recoverability evaluation and the impact strength and appearance evaluation of the single layer film were performed according to the evaluation methods (2) and (3) described above. Table 1 shows the results.
<Conditions for preparing mixed pellets>
Extruder: Twin-screw segment extruder (2D30W2) manufactured by Toyo Seiki Seisakusho Co., Ltd. Screw diameter: 25 mmφ, L / D = 30
Screw rotation speed: 100 rpm
Cylinder and die temperature settings: C1/C2/C3/C4/C5/D=180/200/220/220/220/220°C
Discharge speed: 6 kg/hour

Using the obtained mixed pellets, a monolayer film having a thickness of 20 μm was produced under the following conditions, and the obtained monolayer film was evaluated for transparency and gas barrier properties according to the above evaluation methods (4) and (5). went. The single-layer film obtained had a haze of 0.4%, which was a good value, and an oxygen permeability of 0.2 cc·20 μm/m ² ·day·atm, which showed a good barrier property.
<Single layer film forming conditions>
Extruder: 20 mm extruder "D2020" manufactured by Toyo Seiki Seisakusho (D (mm) = 20, L / D = 20, compression ratio = 3.5, screw: full flight)
Cylinder temperature: supply part 190°C, compression part 220°C, metering part 220°C
Die temperature: 220°C
Screw rotation speed: 40 rpm
Take-up roll temperature: 80°C
Film thickness: 20 μm

[Example 17]
EVOH (B1-1) (ethylene unit content 27 mol% EVOH), EVOH (B2-1) (ethylene unit content 44 mol% EVOH) and copolymer (C-1) at a mass ratio (C/B2/ Using a twin-screw extruder, melt-blending was performed under the following kneading conditions so that B1) was 5/19/86 to obtain mixture pellets. A multilayer film [layer structure: PO (A-1)/acid-modified PO (D-1)/mixture /acid-modified PO (D-1)/PO (A-1), thickness (μm): 80/8/17/8/80]. The obtained multilayer film was pulverized with a pulverizer to obtain a recovered product. Using the obtained recovered product as a resin composition pellet, the recoverability evaluation and the impact strength and appearance evaluation of the single layer film were performed according to the evaluation methods (2) and (3) described above. Table 1 shows the results.

<Conditions for preparing mixed pellets>
Extruder: Twin-screw segment extruder (2D30W2) manufactured by Toyo Seiki Seisakusho Co., Ltd. Screw diameter: 25 mmφ, L / D = 30
Screw rotation speed: 100 rpm
Cylinder and die temperature settings: C1/C2/C3/C4/C5/D=180/200/220/220/220/220°C
Discharge speed: 6 kg/hour

A monolayer film was produced from the obtained mixed pellets in the same manner as in Example 16 and evaluated. The haze of the single-layer film is a good value of 0.4%, and the oxygen permeability is 0.3 cc·20 μm/m ² ·day·atm, which is slightly inferior to the single-layer film of Example 16. Maintained good gas barrier properties.

[Comparative Example 4]
EVOH (B1-1) (ethylene unit content 27 mol% EVOH) and acid-modified PO (D-1) (Admer (trademark) QF500) were biaxially adjusted so that the mass ratio (D/B) was 5/95. Using an extruder, melt blending was performed under the following kneading conditions to obtain mixture pellets. In the same manner as in Example 15, a multilayer film [layer structure: PO (A-1)/acid-modified PO (D-1)/mixture/acid-modified PO (D-1)/PO (A-1), thickness (μm) : 80/8/17/8/80]. The obtained multilayer film was pulverized with a pulverizer to obtain a recovered product. Using the obtained recovered product as a resin composition pellet, the recoverability evaluation and the impact strength and appearance evaluation of the single layer film were performed according to the evaluation methods (2) and (3) described above. Table 1 shows the results.
<Conditions for preparing mixed pellets>
Extruder: Twin-screw segment extruder (2D30W2) manufactured by Toyo Seiki Seisakusho Co., Ltd. Screw diameter: 25 mmφ, L / D = 30
Screw rotation speed: 100 rpm
Cylinder and die temperature settings: C1/C2/C3/C4/C5/D=180/200/220/220/220/220°C
Discharge speed: 6 kg/hour

A monolayer film was produced from the obtained mixed pellets in the same manner as in Example 16 and evaluated. The haze of the single-layer film was a poor value of 1.3%, and the oxygen permeability was 0.2 cc·20 μm/m ² ·day·atm, indicating good gas barrier properties.

Claims (12)

Based on 100 parts by mass of polyolefin (A), 0.1 to 20 parts by mass of ethylene-vinyl alcohol copolymer (B) having an ethylene unit content of 15 to 60 mol% and a degree of saponification of 85 mol% or more and a fragrance 0.1 to 10 parts by mass of a block copolymer (C) of an aromatic vinyl compound and an olefin, wherein the block copolymer (C) of the aromatic vinyl compound and an olefin has a halogen , and the aromatic vinyl compound and an olefin block copolymer (C) has a melt flow rate of 1.0 g/10 min or more at 230° C. under a load of 2160 g, measured according to JIS K 7210:2014. The block copolymer (C) of an aromatic vinyl compound and an olefin has a melt flow rate of 1.0 g/10 min or more and 100 g/10 min or less at 230° C. and a load of 2160 g, measured in accordance with JIS K 7210:2014. The resin composition of claim 1, wherein 3. The resin composition according to claim 1, wherein the block copolymer (C) of an aromatic vinyl compound and an olefin is a halogen-containing styrene-isobutylene-styrene block copolymer. The ethylene-vinyl alcohol copolymer (B) includes an ethylene-vinyl alcohol copolymer (B1) having an ethylene unit content of 15 mol% or more and less than 40 mol% and an ethylene unit content of 40 mol% or more and 60 mol% or less. The resin composition according to any one of claims 1 to 3, comprising an ethylene-vinyl alcohol copolymer (B2). A resin composition containing a polyvalent metal compound (G) having at least one metal atom selected from the group consisting of magnesium, calcium and zinc, with respect to the content of the polyvalent metal compound (G) in the resin composition The content of the polyvalent metal compound (G) relative to the ethylene-vinyl alcohol copolymer (B), calculated by multiplying the content (% by mass) of the ethylene-vinyl alcohol copolymer (B) in the product, is 5. The resin composition according to any one of claims 1 to 4, which is ~1000 ppm. The resin composition according to any one of claims 1 to 5, comprising 0.1 to 20 parts by mass of the acid-modified polyolefin (D) per 100 parts by mass of the polyolefin (A). At least one of the layers constituting the multilayer structure comprising the polyolefin (A) layer and the ethylene-vinyl alcohol copolymer (B) layer contains a block copolymer (C) of an aromatic vinyl compound and an olefin. 7. The method for producing the resin composition according to any one of claims 1 to 6, comprising a step of melt-kneading the multilayer structure. A multilayer structure comprising a polyolefin (A) layer and the ethylene-vinyl alcohol copolymer (B) layer, and an ethylene-vinyl alcohol copolymer comprising a block copolymer (C) of an aromatic vinyl compound and an olefin as main components. 7. The method for producing the resin composition according to any one of claims 1 to 6, comprising a step of melt-kneading with a polymer recovery aid. A multilayer structure comprising a resin composition layer according to any one of claims 1 to 6, a polyolefin (A) layer, the ethylene-vinyl alcohol copolymer (B) layer and an acid-modified polyolefin (D) layer. A molded article having the resin composition layer according to any one of claims 1 to 6. An ethylene-vinyl alcohol copolymer recovery aid containing as a main component a block copolymer (C) of an aromatic vinyl compound and an olefin used in the resin composition according to any one of claims 1 to 6. . A self-recovery type ethylene-vinyl alcohol copolymer resin composition comprising 0.1 to 30 parts by mass of the recovery aid according to claim 11 per 100 parts by mass of the ethylene-vinyl alcohol copolymer (B).