Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
  • C08L23/0807—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms
  • C08L23/0815—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms with aliphatic 1-olefins containing one carbon-to-carbon double bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2203/00—Applications
  • C08L2203/16—Applications used for films
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
  • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend

Definitions

• the present invention relates to a resin composition, a multilayer structure, a film, a packaging material, a pouch, a secondary molded product, and a method for producing a resin composition.
• Ethylene-vinyl alcohol copolymers (hereinafter sometimes referred to as "EVOH") and polyolefin resins are generally used by melt molding to form multilayer structures such as packaging films and containers for food, etc.
• Patent Document 1 discloses a resin composition that contains an ethylene-vinyl acetate copolymer and EVOH having an ethylene content of 70 mol% or more as a compatibilizer, with the EVOH content being 1 to 30 parts by mass per 100 parts by mass of the ethylene-vinyl acetate copolymer.
• Patent Document 2 also describes a polymeric composition for use in a polymeric composition
• a polymeric composition comprising a polyolefin, EVOH having an ethylene content of 20 to 60 mol% and a degree of saponification of vinyl acetate units of 96% or more, a specific amount of a metal salt of a higher fatty acid having 8 to 22 carbon atoms, a conjugated polyene compound having a boiling point of 20°C or more, an ethylene-vinyl acetate copolymer (EVAc), and a saponified ethylene-vinyl acetate copolymer (S-EVOH) having an ethylene content of 68 to 98 mol% and a degree of saponification of vinyl acetate units of 20% or more, and the weight ratio of the polyolefin and EVOH
• the resin composition disclosed has a ratio of 60:40 to 99.9:0.1, and contains a higher fatty acid metal salt in the range of 0.0001 to 10 parts by mass per 100 parts by
• Patent Documents 1 and 2 can improve the compatibility between EVOH and polyolefin resins, but this is not sufficient, and further improvements are required in terms of appearance (transparency) and mechanical properties, especially impact resistance.
• appearance and mechanical properties tend to be inferior, so further improvements are required in the appearance and mechanical properties when recycled raw materials are used.
• the present invention provides a resin composition that has excellent appearance and mechanical properties even when it contains EVOH and polyolefin resin, and in particular, provides a resin composition that has excellent transparency and mechanical properties even when EVOH and polyolefin are used as recycled raw materials.
• a resin composition comprising EVOH (A), a polyethylene resin (B), and a polyolefin resin (C) having a polar group
• the polyethylene resin (B) contains structural units derived from 1-hexene and/or 1-octene,
• the polyethylene resin (B) has a weight average molecular weight of 230,000 or more
• the polyolefin resin (C) having a polar group has a melt flow rate (190 ° C., load 2160 g) measured in accordance with JIS K7210:2014 of 0.15 to 50 g / 10 min.
• a film comprising the resin composition according to any one of [1] to [4].
• a packaging material comprising the resin composition according to any one of [1] to [4].
• a pouch comprising the resin composition according to any one of [1] to [4].
• a secondary molded product comprising the resin composition according to any one of [1] to [4].
• a method for producing the resin composition according to any one of [1] to [4] A method for producing a resin composition, comprising the step of mixing the EVOH (A), a polyethylene resin (B), and a polyolefin resin (C) having a polar group.
• the resin composition of the present invention has excellent transparency and impact resistance, and even when EVOH or polyolefin is used as a recycled raw material, it has excellent transparency and mechanical properties.
• x and/or y (x and y are optional configurations) means at least one of x and y, and means three possibilities: x only, y only, and x and y.
• the upper limit or lower limit of a numerical range described in stages can be arbitrarily combined with the upper limit or lower limit of a numerical range of another stage.
• the upper limit or lower limit of the numerical range can be replaced with a value shown in the examples.
• the monomer units contained in the copolymer resin may be simply referred to as “units.”
• ethylene unit a monomer unit based on ethylene
• a resin composition according to one embodiment of the present invention contains EVOH (A), a polyethylene resin having specific structural units (B), and a polyolefin resin having a polar group (C).
• the EVOH (A), the polyethylene resin (B), and the polyolefin resin (C) having a polar group may be virgin products or recycled products. Of these, recycled products are preferred, and it is particularly preferred in terms of the effects of the present invention to use a multilayer structure containing the EVOH (A) and the polyethylene resin (B) or scraps such as end materials of the multilayer structure as raw materials.
• each component will be described below.
• the EVOH (A) is a resin obtained by saponifying an ethylene-vinyl ester copolymer, which is a copolymer of ethylene and a vinyl ester monomer, and is a water-insoluble thermoplastic resin. From an economical point of view, vinyl acetate is generally used as the vinyl ester monomer.
• the polymerization method of ethylene and the vinyl ester monomer can be carried out by any known polymerization method, for example, solution polymerization, suspension polymerization, or emulsion polymerization, and generally, solution polymerization using methanol as a solvent is used.
• the ethylene-vinyl ester copolymer obtained can also be saponified by a known method.
• the EVOH (A) thus produced is mainly composed of structural units derived from ethylene and vinyl alcohol structural units, and generally contains a small amount of vinyl ester structural units remaining without being saponified.
• vinyl ester monomer vinyl acetate is typically used because of its market availability and the efficiency of impurity treatment during production.
• Other vinyl ester monomers include, for example, aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl versatate, and aromatic vinyl esters such as vinyl benzoate.
• Aliphatic vinyl esters having typically 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, and particularly preferably 4 to 7 carbon atoms, can be used. These can be used alone or in combination of two or more kinds.
• the vinyl ester monomer is usually made from petroleum-derived raw materials such as naphtha, but it may also be made from natural gas-derived raw materials such as shale gas, or from plant-derived raw materials refined from sugar, starch, and other components contained in sugar cane, sugar beet, corn, potatoes, and other plants, or from cellulose and other components contained in plants such as rice, wheat, and millet.
• petroleum-derived raw materials such as naphtha
• natural gas-derived raw materials such as shale gas
• plant-derived raw materials refined from sugar, starch, and other components contained in sugar cane, sugar beet, corn, potatoes, and other plants, or from cellulose and other components contained in plants such as rice, wheat, and millet.
• the ethylene unit content in EVOH (A) can be controlled by the ethylene pressure when the vinyl ester monomer and ethylene are copolymerized, and is preferably 20 to 60 mol%. More preferably, it is 25 to 55 mol%, even more preferably 28 to 50 mol%, particularly preferably 30 to 45 mol%, and especially preferably 32 to 45 mol%.
• EVOH (A) preferably contains EVOH with such a content of 32 mol% or more, in order to further improve mechanical properties and secondary moldability. If the content is too low, the gas barrier properties and melt moldability under high humidity tend to decrease, and conversely, if it is too high, the gas barrier properties tend to decrease.
• the ethylene unit content can be measured, for example, based on ISO 14663.
• the degree of saponification of the vinyl ester component in EVOH (A) can be controlled by the amount, temperature, time, and the like of a saponification catalyst (usually, an alkaline catalyst such as sodium hydroxide is used) used when saponifying the ethylene-vinyl ester copolymer.
• a saponification catalyst usually, an alkaline catalyst such as sodium hydroxide is used
• the degree of saponification of the vinyl ester component in EVOH (A) is preferably 80 mol % or more, more preferably 90 mol % or more, even more preferably 98 mol % or more, and particularly preferably 99 mol % or more, and may be 100 mol %.
• the degree of saponification of the vinyl ester unit of the EVOH (A) is a value measured based on JIS K6726 (wherein EVOH is a solution uniformly dissolved in a water/methanol solvent).
• the melt flow rate (MFR) of EVOH (A) (210°C, load 2160 g) is usually 0.5 to 100 g/10 min, preferably 1 to 50 g/10 min, and particularly preferably 3 to 35 g/10 min. If the MFR is too high, the film formability tends to be unstable, whereas if the MFR is too low, the viscosity tends to be too high, making melt extrusion difficult.
• the MFR is an index of the degree of polymerization of EVOH (A), and can be adjusted by the amount of polymerization initiator and the amount of solvent used when copolymerizing ethylene with a vinyl ester monomer.
• EVOH (A) may be copolymerized with polymerizable monomers other than ethylene and vinyl ester monomers within a range that does not impair the effects of the present invention, generally within a range of 5 mol% or less.
• polymerizable monomers include ⁇ -olefins such as propylene, isobutene, ⁇ -octene, ⁇ -dodecene, and ⁇ -octadecene; hydroxyl-containing ⁇ -olefins such as 3-buten-1-ol, 4-penten-1-ol, and 3-buten-1,2-diol, and hydroxyl-containing ⁇ -olefin derivatives such as their esters and acylations; hydroxymethylvinylidene diacetates such as 1,3-diacetoxy-2-methylenepropane, 1,3-dipropionyloxy-2-methylenepropane, and 1,3-dibutyronyloxy-2-methyleneprop
• EVOH (A) used in the present invention may be any EVOH having a primary hydroxyl group on the side chain.
• EVOH having a primary hydroxyl group on the side chain include EVOH copolymerized with hydroxyl group-containing ⁇ -olefins and EVOH having a 1,2-diol structure on the side chain.
• the content of structural units derived from the monomer having the primary hydroxyl group is usually 0.1 to 20 mol %, preferably 0.5 to 15 mol %, and particularly preferably 1 to 10 mol % of the EVOH.
• the EVOH does not have a primary hydroxyl group on the side chain.
• EVOH (A) may be "post-modified” such as urethane, acetal, cyanoethyl, or oxyalkylenated.
• the EVOH (A) may be used alone or in combination of two or more kinds having different vinyl ester types, ethylene unit contents, physical properties, etc. From the viewpoint of compatibility, it is preferable that only one type of EVOH is used, or when multiple types are used, the melting points of the types are preferably all 170°C or higher, or all lower than 170°C. In the present invention, the melting point is measured according to the method described in JIS K7121 by first heating a sample to 200° C. with a differential scanning calorimeter (DSC), then cooling the sample at a cooling rate of 30° C./min to a temperature about 50° C. lower than the glass transition point, and then heating the sample again at a heating rate of 10° C./min (second run).
• DSC differential scanning calorimeter
• the content of the EVOH (A) in the resin composition is usually 0.1 to 40% by mass, preferably 0.3 to 35% by mass, more preferably 0.5 to 30% by mass, and particularly preferably 0.7 to 25% by mass.
• the molded product obtained tends to have a good appearance and excellent mechanical properties.
• Polyethylene resin (B) The polyethylene resin (B) used in the present invention contains structural units derived from ethylene and structural units derived from 1-hexene and/or 1-octene. By containing structural units derived from 1-hexene and/or 1-octene, the mechanical properties of the polyethylene resin (B) can be improved.
• the content of structural units derived from 1-hexene and/or 1-octene in the polyethylene resin (B) is preferably 2.0 mol% or more, more preferably 3.0 mol% or more, even more preferably 3.2 mol% or more, particularly preferably 3.4 mol% or more, and most preferably 3.6 mol% or more. There is no particular upper limit, but it is usually 15 mol%, preferably 13 mol%, more preferably 11 mol%, and particularly preferably 10 mol%.
• the density of the polyethylene resin (B) is 0.850 to 0.920 g/cm 3 , preferably 0.860 to 0.920 g/cm 3 , more preferably 0.870 to 0.920 g/cm 3 , and even more preferably 0.880 to 0.920 g/cm 3.
• the density can be measured by a density meter.
• polyethylene resin (B) examples include, but are not limited to, linear low-density polyethylene, low-density polyethylene, very low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
• polyethylene resin (B) examples include modified polyethylene resins such as unsaturated carboxylic acid-modified polyethylene resins obtained by graft-modifying polyethylene resins with unsaturated carboxylic acids or their esters. These may be used alone or in combination of two or more. Of these, linear low density polyethylene is preferred.
• the raw material for the polyethylene resin may be derived from petroleum or from plants.
• the polyethylene resin (B) is obtained by polymerizing a copolymerization component containing ethylene and 1-hexene and/or 1-octene, but may contain ⁇ -olefins other than 1-hexene and 1-octene as copolymerization components.
• the other ⁇ -olefins include ⁇ -olefins having 2 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-heptene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, and 2,2,4-trimethyl-1-pentene. These may be used alone or in combination of two or more.
• the polyethylene resin (B) contains structural units derived from other ⁇ -olefins, the content is usually 5 mol% or less, and preferably 2 mol% or less.
• the weight average molecular weight of the polyethylene resin (B) is 230,000 or more in polystyrene equivalent, more preferably 235,000 or more, even more preferably 240,000 or more, particularly preferably 245,000 or more, especially preferably 250,000 or more, and most preferably 253,000 or more.
• the upper limit is not particularly limited, but is usually 400,000.
• the weight average molecular weight of the polyethylene resin (B) can be measured by GPC.
• the melt flow rate (MFR, 190°C, load 2160 g) of polyethylene resin (B) measured in accordance with JIS K7210:2014 is not particularly limited, but from the viewpoint of moldability, it is usually 0.01 to 50 g/10 min, more preferably 0.1 to 10 g/10 min.
• the MFR can be measured using a melt indexer.
• Preferred examples of commercially available polyethylene resins (B) of the present invention include Innate (registered trademark) manufactured by The Dow Chemical Company, Exceed (registered trademark) manufactured by ExxonMobil Corporation, and Novatec (registered trademark) manufactured by Japan Polyethylene Corporation.
• the content of the polyethylene resin (B) in the resin composition is usually 60 to 99.8% by mass, preferably 65 to 99.7% by mass, more preferably 70 to 99.5% by mass, and particularly preferably 75 to 99.3% by mass.
• the molded product obtained tends to have a good appearance and excellent mechanical properties.
• the content ratio of EVOH (A) to the polyethylene resin (B) [(A)/(B)] is preferably 40/60 to 0.1/99.9 by mass, more preferably 35/65 to 0.3/99.7, even more preferably 30/70 to 0.5/99.5, and particularly preferably 25/75 to 0.7/99.3.
• the content ratio of polyethylene resin (B) to EVOH (A) is within the above range, the molded product obtained tends to have a good appearance and excellent mechanical properties.
• a sea-island structure is formed in which EVOH (A) is dispersed as an island phase in the sea phase (matrix) of polyethylene resin (B).
• EVOH (A) is dispersed as an island phase in the sea phase (matrix) of polyethylene resin (B).
• Polyolefin resin (C) having polar group examples include polyolefin resins containing a carboxy group obtained by chemically bonding an unsaturated carboxylic acid or an anhydride thereof to a polyolefin resin by addition reaction, graft reaction, or the like.
• polyolefin resin having a carboxy group examples include maleic anhydride-modified polymers such as maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-propylene (block and random) copolymers, maleic anhydride grafted ethylene-ethyl acrylate copolymers, maleic anhydride grafted ethylene-vinyl acetate copolymers, maleic anhydride-modified polycyclic olefin resins, and maleic anhydride grafted polyolefin resins. These may be used alone or as a mixture of two or more.
• maleic anhydride-modified polymers such as maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-propylene (block and random) copolymers, maleic anhydride grafted ethylene-ethyl acrylate copolymers
• maleic anhydride-modified polyolefin resins such as maleic anhydride-modified polyethylene and maleic anhydride-modified ethylene- ⁇ -olefin copolymer are particularly suitable, as they contribute to the suppression of gel formation during melt heating and the suppression of a decrease in transparency.
• the melt flow rate (MFR, 190°C, load 2160 g) of the polyolefin resin (C) having polar groups is 0.15 to 50 g/10 min, preferably 0.4 to 40 g/10 min, more preferably 0.7 to 30 g/10 min, even more preferably 1 to 25 g/10 min, and particularly preferably 1.2 to 20 g/10 min.
• MFR of the polyolefin resin (C) having polar groups is within the above range, the processability is excellent, and the molded product obtained has a good appearance and excellent mechanical properties.
• the melt flow rate of the polyolefin resin (C) having polar groups is outside the above range, the processability, appearance, and mechanical properties are reduced.
• melt flow rate is expressed in terms of melt viscosity calculated from the following formula (1)
• 0.15 g/10 min is about 1,650,000 cP
• 50 g/10 min is about 205,000 cP.
• MFR (190°C, load 2160g) 3.6126 [10 (log( ⁇ )-6.6928)/-1.1363 ] -9.31851... (1)
• ⁇ is the melt viscosity at 350° F.
• the acid value of the polyolefin resin (C) having polar groups is usually 50 mgKOH/g or less, preferably 30 mgKOH/g or less, and particularly preferably 20 mgKOH/g or less. If the acid value is too high, the number of reaction sites with the hydroxyl groups in the EVOH increases, and high polymerization products are generated during the melt-kneading process, reducing stability during extrusion processing and making it difficult to obtain good molded products.
• the lower limit of the acid value is usually 1 mgKOH/g, and preferably 2 mgKOH/g. The acid value is measured based on JIS K0070.
• the content of the polyolefin resin (C) having a polar group in the resin composition is usually 0.1 to 40 mass%, preferably 0.3 to 35 mass%, more preferably 0.5 to 30 mass%, and particularly preferably 0.7 to 25 mass%.
• the molded product obtained tends to have a good appearance and excellent mechanical properties.
• the resin composition may contain other components than those mentioned above, such as antiblocking agents, processing aids, resins other than EVOH (A), polyethylene resin (B), and polyolefin resin (C) having a polar group, carboxylic acid compounds, phosphoric acid compounds, boron compounds, metal salts, stabilizers, antioxidants, UV absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, surfactants, desiccants, crosslinking agents, reinforcing agents such as various fibers, etc., as long as the effects of the present invention are not impaired. These may be used alone or in combination of two or more.
• the resin composition can be produced by a production method including a step of mixing the EVOH (A), the polyethylene resin (B), the polyolefin resin (C) having a polar group, etc., such as a dry blending method, a melt mixing method, etc. These production methods can also be used in any combination.
• the EVOH (A), polyethylene resin (B), and polyolefin resin (C) having a polar group may be virgin products or recycled products.
• laminates in which a layer containing EVOH and a layer containing polyethylene resin are laminated together are widely used as packaging materials.
• this laminate containing EVOH and polyethylene resin is recycled as is to be used as a raw material for a resin composition, EVOH and polyethylene resin have poor compatibility, and the appearance and mechanical properties tend to deteriorate.
• a specific polyethylene resin (B) and a polyolefin resin (C) having a polar group it has been discovered that by using a specific polyethylene resin (B) and a polyolefin resin (C) having a polar group, a good appearance and excellent mechanical properties can be achieved.
• the recycled products When using the recycled products, their content is 50% by mass or less of the resin composition, preferably 40% or less, and particularly preferably 30% or less. If the recycled content is too high, the transparency and impact resistance tend to be inferior.
• the dry blending method may, for example, be (i) a method in which pelletized EVOH resin (A), polyethylene resin (B), and polyolefin resin having polar groups (C) are dry blended using a tumbler or the like.
• melt mixing method examples include (ii) a method of melt-kneading a dry blend of pelletized EVOH (A), polyethylene resin (B), and polyolefin resin (C) having polar groups, and (iii) a method of melt-kneading molten EVOH (A), polyethylene resin (B), and polyolefin resin (C) having polar groups.
• melt mixing method is preferred, and method (ii) is particularly preferred, in terms of productivity and the fact that a resin composition can be obtained in which the effects of the present invention are more pronounced.
• other thermoplastic resins and other compounding agents they may be compounded in a conventional manner according to a known manufacturing method.
• the present resin composition obtained by each of the above-mentioned production methods may have any shape, but is preferably in the form of pellets.
• the pellets may be, for example, spherical, oval, cylindrical, cubic, rectangular, etc., but are usually oval or cylindrical, and from the viewpoint of convenience when used later as a molding material, the size of the pellets is, in the case of an oval shape, usually 1 to 10 mm, preferably 2 to 6 mm, and more preferably 2.5 to 5.5 mm in minor axis and usually 1.5 to 30 mm, preferably 3 to 20 mm, and more preferably 3.5 to 10 mm in major axis.
• the diameter of the base is usually 1 to 6 mm, preferably 2 to 5 mm, and the length is usually 1 to 6 mm, preferably 2 to 5 mm.
• the pellet-like EVOH (A), polyethylene resin (B) and polyolefin resin having a polar group (C) used in each of the above-mentioned production methods have the same shape and size.
• a known lubricant when the resin composition is in the form of pellets, it is also preferable to attach a known lubricant to the surface of the pellets in order to stabilize the feedability during melt molding.
• types of lubricants include higher fatty acids having 12 or more carbon atoms (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, etc.), higher fatty acid esters (methyl esters, isopropyl esters, butyl esters, octyl esters of higher fatty acids, etc.), higher fatty acid amides (saturated higher fatty acid amides such as lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, etc.; unsaturated higher fatty acid amides such as oleic acid amide, erucic acid amide, etc.; bis-higher fatty acid amide
• the resin composition obtained in this way has excellent transparency and impact resistance.
• the total haze of the present resin composition is preferably 60% or less, more preferably 55% or less, and particularly preferably 50% or less.
• the total haze can be determined by forming the present resin composition into a single-layer film having a thickness of 30 ⁇ m and measuring the haze with a haze meter.
• the impact strength (g) of the present resin composition is preferably 50 g or more, more preferably 200 g or more, further preferably 400 g or more, and particularly preferably 600 g or more.
• the impact strength (g) is the maximum mass of a weight that can be applied to a 30 ⁇ m-thick monolayer film of the resin composition and that can be dropped from a height of 0.66 m onto the monolayer film using a dart impact tester.
• This resin composition is prepared in various forms, such as pellets, powder, or liquid, and is provided as a molding material for various molded products.
• the molded product may be, for example, a monolayer film molded from the resin composition, as well as packaging materials, pouches, and multilayer structures having at least one layer made of the resin composition.
• the molded product may also be subjected to secondary processing, as described below, to produce a secondary processed product.
• a multilayer structure according to one embodiment of the present invention has at least one layer made of the present resin composition.
• the layer made of the present resin composition (hereinafter simply referred to as “the present resin composition layer”) can be laminated with a layer made of another resin composition containing a thermoplastic resin other than the present resin composition as a main component (hereinafter simply referred to as “another resin layer”) to impart further strength, protect the present resin composition layer from the effects of moisture, etc., or impart other functions.
• the thermoplastic resins include, for example, polyethylene resins such as linear low-density polyethylene, low-density polyethylene, very low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene (block and random) copolymers, and ethylene- ⁇ -olefin ( ⁇ -olefin having 4 to 20 carbon atoms) copolymers; polypropylene resins such as polypropylene and propylene- ⁇ -olefin ( ⁇ -olefin having 4 to 20 carbon atoms) copolymers; (unmodified) polyolefin resins such as polybutene, polypentene, and polycyclic olefin resins (polymers having a cyclic olefin structure in at least one of the main chain and side chains); and unsaturated carbamide resins such as polyolefins.
• polyethylene resins such as linear low-density polyethylene, low-density polyethylene,
• polyolefin resins examples include broadly defined polyolefin resins, such as unsaturated carboxylic acid-modified polyolefin resins graft-modified with carboxylic acid or its ester, ionomers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, polyester resins, polyamide resins (including copolymerized polyamides), polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene resins, vinyl ester resins, polyester elastomers, polyurethane elastomers, polystyrene elastomers, halogenated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, and aromatic or aliphatic polyketones. These may be used alone or in combination of two or more.
• hydrophobic resins such as polyamide resins, polyolefin resins, polyester resins, and polystyrene resins are preferred, and more preferred are polyolefin resins such as polyethylene resins, polypropylene resins, polycyclic olefin resins, and unsaturated carboxylic acid modified polyolefin resins of these.
• the layer structure of the multilayer structure can be any combination of a/b, b/a/b, a/b/a, a1/a2/b, a/b1/b2, b2/b1/a/b1/b2, b2/b1/a/b1/a/b1/b2, etc., where a represents the resin composition layer and b represents the other resin layers.
• R represents a recycled layer containing a mixture of the resin composition and a thermoplastic resin other than the resin composition, obtained by remelting and molding ends or defective products generated during the manufacturing process of the multilayer structure
• b/R/a, b/R/a/b, b/R/a/R/b, b/a/R/a/b, b/R/a/R/a/R/b, etc. are also possible.
• the total number of layers in the multilayer structure is usually 2 to 15, and preferably 3 to 10.
• an adhesive resin layer containing an adhesive resin may be interposed between each layer as necessary.
• thermoplastic resin any known adhesive resin can be used, and it may be appropriately selected according to the type of thermoplastic resin used in the other resin layer "b".
• a representative example is a modified polyolefin polymer containing a carboxy group obtained by chemically bonding an unsaturated carboxylic acid or its anhydride to a polyolefin resin by an addition reaction, a graft reaction, or the like.
• modified polyolefin polymer containing a carboxy group examples include maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-propylene (block and random) copolymer, maleic anhydride grafted ethylene-ethyl acrylate copolymer, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride modified polycyclic olefin resin, maleic anhydride grafted polyolefin resin, etc. These may be used alone or in combination of two or more.
• an adhesive resin layer is used between the resin composition layer and another resin layer in the multilayer structure, since the adhesive resin layers are located on both sides of the resin composition layer, it is preferable to use an adhesive resin with excellent hydrophobicity.
• the other resins and adhesive resins may contain conventionally known plasticizers, fillers, clays (montmorillonite, etc.), colorants, antioxidants, antistatic agents, lubricants, core materials, antiblocking agents, waxes, etc., within the range that does not impair the purpose of the present invention (for example, 30% by mass or less, preferably 10% by mass or less, based on the total resin). These may be used alone or in combination of two or more kinds.
• the lamination of the resin composition layer and the other resin layer can be performed by a known method.
• a method of melt extrusion laminating another resin onto a film, sheet, etc. of the resin composition a method of melt extrusion laminating the resin composition onto another resin layer, a method of co-extruding the resin composition with another resin, a method of dry laminating the resin composition (layer) with the other resin composition or another resin layer using a known adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound, a polyurethane compound, etc., a method of applying a solution of the resin composition onto the other resin and then removing the solvent, etc.
• a manufacturing method including a step of melt molding the resin composition layer is preferred from the viewpoint of cost and environment, and specifically, a co-extrusion method is preferred.
• the multilayer structure may be stretched (by heating) as necessary.
• the stretching may be either uniaxial or biaxial, and in the case of biaxial stretching, it may be simultaneous or sequential.
• a method that provides a high stretch ratio may be used, such as roll stretching, tenter stretching, tubular stretching, stretch blowing, or vacuum/compressed air molding.
• the stretching temperature is a temperature near the melting point of the multilayer structure, and is usually selected from the range of 40 to 170°C, preferably 60 to 160°C. If the stretching temperature is too low, the stretchability will be poor, and if it is too high, it will be difficult to maintain a stable stretched state.
• the multilayer structure after the stretching treatment may be heat-set in order to impart dimensional stability.
• Heat-setting can be performed by known means, for example, the multilayer structure after the stretching treatment is heat-treated, usually at 80 to 180°C, preferably 100 to 165°C, for about 2 to 600 seconds while maintaining tension.
• the heat setting described above may not be carried out, and instead, a process such as cooling and setting the multilayer structure after stretching may be carried out, for example, by blowing cold air on the multilayer structure to provide heat shrinkability.
• the thickness of the present multilayer structure (including the stretched one), and further the thickness of the present resin composition layer, other resin layers, and adhesive resin layers constituting the multilayer structure, cannot be generally determined depending on the layer configuration, the type of other resin, the type of adhesive resin, the application, packaging form, required physical properties, etc., but the thickness of the present multilayer structure (including the stretched one) is usually 10 to 5000 ⁇ m, preferably 30 to 3000 ⁇ m, and particularly preferably 50 to 2000 ⁇ m.
• the present resin composition layer is usually 1 to 500 ⁇ m, preferably 3 to 300 ⁇ m, and particularly preferably 5 to 200 ⁇ m
• the other resin layers are usually 5 to 3000 ⁇ m, preferably 10 to 2000 ⁇ m, and particularly preferably 20 to 1000 ⁇ m
• the adhesive resin layer is usually 0.5 to 250 ⁇ m, preferably 1 to 150 ⁇ m, and particularly preferably 3 to 100 ⁇ m.
• the thickness ratio of the present resin composition layer to the other resin layers in the present multilayer structure in terms of the ratio between the thickest layers when there are multiple layers of each type, is usually 1/99 to 50/50, preferably 5/95 to 45/55, and particularly preferably 10/90 to 40/60.
• the thickness ratio of the present resin composition layer to the adhesive resin layer in the present multilayer structure in terms of the ratio between the thickest layers when there are multiple layers of each type, is usually 10/90 to 99/1, preferably 20/80 to 95/5, and particularly preferably 50/50 to 90/10.
• multilayer containers such as cups, trays, packaging materials, and pouches using the multilayer structure.
• a squeeze molding method is usually used, specifically, vacuum molding, pressure molding, vacuum pressure molding, plug-assisted vacuum pressure molding, etc. are mentioned.
• a tube- or bottle-shaped multilayer container laminate structure
• a multilayer parison a hollow tubular preform before blowing
• extrusion blow molding double-head type, mold moving type, parison shift type, rotary type, accumulator type, horizontal parison type, etc.
• cold parison type blow molding injection blow molding
• biaxial stretch blow molding extrusion type cold parison biaxial stretch blow molding, injection type cold parison biaxial stretch blow molding, injection molding in-line type biaxial stretch blow molding, etc.
• secondary processing such as heat treatment, cooling treatment, rolling treatment, printing treatment, dry lamination treatment, solution or melt coating treatment, bag making, deep drawing, box processing, tube processing, split processing, etc., as necessary, to produce a secondary processed product.
• Single-layer films formed from this resin composition, bags made from this multilayer structure, and containers and lids made from cups, trays, tubes, bottles, packaging materials, pouches, etc. are useful as various packaging materials and containers for general foods, as well as seasonings such as mayonnaise and dressings, fermented foods such as miso, oily foods such as salad oil, beverages, cosmetics, pharmaceuticals, etc.
• B2 "Exceed (registered trademark) XP 8784” manufactured by ExxonMobil Corporation (a copolymer of ethylene and 1-hexene, content of structural units derived from 1-hexene: 4.6 mol%, density: 0.914 g/cm 3 , MFR (190° C., load: 2160 g): 0.80 g/10 min, weight average molecular weight (polystyrene equivalent): 269,000)
• B3 "Innate (registered trademark) ST50” manufactured by The Dow Chemical Company (a copolymer of ethylene and 1-octene, the content of structural units derived from 1-octene is 3.2 mol%, the density is 0.918 g/cm 3 , MFR (190° C., load 2160 g) is 0.85 g/10 min, and the weight average molecular weight (polystyrene equivalent) is 251,000).
• B5 "Anteo (registered trademark) FK2715” manufactured by Borouge (copolymer of ethylene and 1-hexene, content of structural units derived from 1-hexene: 1.6 mol%, density: 0.927 g/cm 3 , MFR (190° C., load: 2160 g): 1.3 g/10 min, weight average molecular weight (polystyrene equivalent): 240,000)
• B'1 "Novatec (registered trademark) UF641” manufactured by Japan Polyethylene Corporation (a copolymer of ethylene and 1-butene, density 0.927 g/cm 3 , MFR (190° C., load 2160 g) 2.1 g/10 min, weight average molecular weight (polystyrene equivalent) 220,000)
• B'2 "Novatec (registered trademark) UF421” manufactured by Japan Polyethylene Corporation (a copolymer of ethylene and 1-butene, density 0.926 g
• the weight average molecular weight of the polyethylene resin (B) and the contents of the respective copolymerization components are values measured by the evaluation methods described below.
• Example 1 A resin composition was obtained by dry blending 5 parts by mass of EVOH (A1), 90 parts by mass of polyethylene resin composition (B1), and 5 parts by mass of polyolefin resin (C1) containing a polar group, and melt-kneading the mixture in a ⁇ 40 mm single-screw extruder.
• the obtained resin composition was cast into a single layer film of 30 ⁇ m using a single layer cast molding machine under the following film forming conditions. (Film-forming conditions) ⁇ 40mm single screw extruder (barrel temperature 220°C) Die temperature: 220°C Take-up speed: 2.0-2.5 m/min
• Examples 2 to 5 Comparative Examples 1 to 3> Resin compositions of Examples 2 to 5 and Comparative Examples 1 to 3 were obtained in the same manner as in Example 1, except that the type of polyethylene resin (B) was changed as shown in Table 1 below. Furthermore, single-layer films having a thickness of 30 ⁇ m were produced from the obtained resin compositions of Examples 2 to 5 and Comparative Examples 1 to 3 in the same manner as in Example 1.
• Examples 1 to 5 in which the specific polyethylene resin (B) was used were superior in transparency and impact strength to Comparative Examples 1 and 2 in which a polyethylene resin not containing a structural unit derived from 1-hexene and/or 1-octene was used.
• Comparative Example 3 which used a polyethylene resin containing structural units derived from 1-hexene and/or 1-octene but having a weight average molecular weight outside the specific range, the total haze deteriorated and transparency and mechanical properties could not be achieved at the same time.
• the resin composition has excellent transparency and impact strength, so it can be used suitably as a packaging material for various packaging containers and packaging films for general foods, as well as seasonings such as mayonnaise and dressings, fermented foods such as miso, oily foods such as salad oil, beverages, cosmetics, and pharmaceuticals.

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