Polar polymer composition and molding

Abstract

To improve impact resistance and fatigue recovery properties of a molded article such as a film obtained from a composition composed of an olefinic polymer such as a polypropylene resin, a polar resin, and acid-modified polyethylene.SOLUTION: There is provided a polar polymer composition, wherein a blending ratio of an olefinic polymer (a) is 50 to 100 mass%, a blending ratio of a polar polymer (b) is 0.1 to 50 mass%, a blending ratio of a modified propylene-based polymer (c) having a grafting amount (modification degree) of 0.4 mass% or more is 0.1 mass% or more and less than 10 mass%, and a blending ratio of a modified olefinic polymer (d) having a grafting amount (modification degree) of less than 0.4 mass% is 0.1 to 50 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polar polymer composition and a molded article. [Background technology]

[0002] Conventionally, various molded articles have been produced using compositions comprising polyolefin polymers such as polypropylene and polar resins such as ethylene vinyl alcohol resin (EVOH). However, since the compatibility of the two components in such compositions is poor, acid-modified polypropylene or the like has been blended as a compatibilizer to improve the impact resistance, fatigue recovery resistance, and other properties of molded articles such as films produced from the compositions.

[0003] Patent Document 1 discloses a composition consisting of polypropylene, EVOH, and maleic anhydride-grafted polypropylene (compatibilizer). Among them, the document lists Compatibilizer G (3.6% by weight of maleic anhydride grafted onto polypropylene) as a compatibilizer made of maleic anhydride, but does not mention its density.Furthermore, the document lists an example of using "Admer QF500" as a compatibilizer, but does not mention its density. Thus, Patent Document 1 states that the density is 0.89 kg / m 3 There is no mention of it being less than that.

[0004] Patent Document 2 describes a "ground material" consisting of polypropylene (hereinafter sometimes abbreviated as PP), PVOH, and an adhesive resin (Ad), and also describes the addition of a compatibilizer thereto. The adhesive resin (Ad) and the compatibilizer (KPP) are both described as modified PP with unsaturated carboxylic acid or its derivatives. The modified PP with unsaturated carboxylic acid or its derivatives used in the examples and comparative examples are all modified PP with graft-modified water and maleic acid, and their densities are 0.89 g / cm. 3, 0.90g / cm 3 and the density is 0.89 kg / m 3 There is no mention of modified products having a molecular weight less than 1000 kJ / kg.

[0005] Patent Document 3 discloses that when a laminate such as a laminate film or a laminate sheet is crushed and reused as a regrind resin in a sheet or the like, it results in a regrind material layer (recycled layer) with improved impact strength and high impact resistance, and describes that the regrind layer is composed of a propylene-ethylene random copolymer, EVOH, and an adhesive resin composition. It describes that the adhesive resin composition is an acid-modified polypropylene resin, but does not describe its density. As for the polypropylene resin before modification used in the acid-modified polypropylene resin, only "isotactic polypropylene homopolymer" is described, and the density is not described. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 04-502032 [Patent Document 2] Japanese Patent Application Publication No. 7-292172 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-328388 Summary of the Invention [Problem to be solved by the invention]

[0007] As a result of extensive research conducted to improve the impact resistance and fatigue recovery resistance of molded articles obtained from compositions comprising polyolefin polymers such as polypropylene resins, polar resins, and acid-modified polypropylene, it was discovered that the impact resistance, fatigue recovery resistance, and other properties of molded articles such as films can be improved by using a modified propylene-based copolymer having a specific graft rate (degree of modification) and density range as a compatibilizer, and this led to the present invention. [Means for solving the problem]

[0008] The present invention has the following aspects [1] to [8]. [1] The polymer comprises an olefin polymer (a), a polar polymer (b), and a modified propylene polymer (c), The modified propylene polymer (c) is obtained by graft-modifying a propylene polymer with an unsaturated carboxylic acid or a derivative thereof, and the graft amount (modification degree) due to the modification is 0.4 mass% or more, and the density thereof is 890 kg / m 3 is less than 50% by mass or more and less than 100% by mass of olefin polymer (a), Polar polymer (b) 0.1-50% by mass, Modified propylene polymer (c) 0.1% by mass or more and less than 20% by mass (The total of (a), (b) and (c) is 100% by mass.) A polar polymer composition comprising: [2] Further, it contains a modified olefin polymer (d), the modified olefin polymer (d) is obtained by graft-modifying an olefin polymer with an unsaturated carboxylic acid or a derivative thereof, and the graft amount (modification degree) resulting from the modification is less than 0.4 mass%; The proportion of the modified olefin polymer (d) is 0.1 to 50% by mass. (The total of (a), (b), (c), and (d) is 100% by mass.) The polar polymer composition according to the above item [1], [3] The polar polymer composition according to the above item [2], wherein the modified propylene polymer (c) and the modified olefin polymer (d) are polymers defined below. Modified propylene polymer (c) Mixing ratio: 0.1% by mass or more, less than 20% by mass Graft amount (modification degree) 0.4 to 5.0 mass% Melt flow rate (MFR: 190℃, 2.16kg) 0.1g / 10min or more, less than 500g / 10min Density 860kg / m 3 More than 890kg / m 3 less than Modified olefin polymer (d) Blending ratio 0.1~50% by mass Graft amount (modification degree): 0.01% by mass or more, less than 0.4% by mass Melt flow rate (MFR: 190℃, 2.16kg) 0.1g / 10min or more, less than 15g / 10min Density 860~960kg / m 3

[0009] [4] The polar polymer composition according to the above item [1], wherein the unsaturated carboxylic acid or a derivative thereof is maleic anhydride. [5] The polar polymer composition according to the above [2] or [3], wherein the unsaturated carboxylic acid or a derivative thereof is maleic anhydride. [6] The polar polymer composition according to any one of the above [1] to [5], wherein the polar polymer (b) comprises at least one polar polymer selected from the group consisting of polyamide resins, polyester resins, and ethylene-vinyl alcohol copolymers. [7] A molded article comprising the polar polymer composition according to any one of the above [1] to [6]. [8] A single-layer or multi-layer film comprising at least one layer containing the polar polymer composition according to any one of the above [1] to [6]. [Effects of the Invention]

[0010] According to the present invention, a regrind composition is obtained from a molded article such as a film, and the properties of the molded article such as a film that are then molded, such as impact resistance and fatigue recovery resistance, are further improved, enabling wider use. DETAILED DESCRIPTION OF THE INVENTION

[0011] The olefin polymer (a), polar polymer (b), and modified propylene polymer (c) constituting the polar polymer composition of the present invention will be described below.

[0012] <<Olefin polymer (a)>> The olefin polymer (a) used in the polar polymer composition of the present invention is not particularly limited, and various known olefin polymers can be used. Examples of the olefin polymer (a) include olefin homopolymers and copolymers containing, as main structural units, structural units derived from an α-olefin having 2 to 20 carbon atoms. The term "main structural units" means that the olefin polymer (a) contains 51 mol % or more of structural units derived from an α-olefin having 2 to 20 carbon atoms, based on the number of moles of all structural units contained therein. The α-olefin having 2 to 20 carbon atoms may be a linear α-olefin or a branched α-olefin. Specific examples of linear α-olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among these α-olefins, α-olefins having 2 to 10 carbon atoms are preferred.

[0013] Specific examples of branched α-olefins having 3 to 20 carbon atoms include 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, trimethyl-1-butene, trimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, methylethylpentene-1, diethylbutene-1, and propylpentene-1. The branched α-olefin preferably has 5 to 20 carbon atoms, and more preferably 5 to 10 carbon atoms.

[0014] The olefin polymer (a) preferably contains, as its main structural units, structural units derived from ethylene, propylene, 1-butene, 1-hexene or 1-octene, more preferably structural units derived from ethylene, propylene or 1-butene, and even more preferably structural units derived from ethylene or propylene.

[0015] The olefin polymer (a) may contain structural units derived from α-olefins in an amount of 51 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more, based on the number of moles of all structural units contained in the olefin polymer. The upper limit of the amount of structural units derived from α-olefins is not particularly specified, and can be 100 mol% (homopolymer).

[0016] The olefin polymer (a) may have, as the main chain, structural units derived from other compounds of these α-olefins. Examples of other compounds include α-olefins having 21 or more carbon atoms, aromatic vinyl compounds including styrene, dienes, and polyenes.

[0017] The olefin polymer (a) has structural units derived from the other compounds in an amount of 49 mol % or less, preferably in the range of 1 to 40 mol %, based on the number of moles of all structural units contained in the olefin polymer.

[0018] The olefin polymer (a) is preferably a polymer having structural units derived from ethylene as the main structural unit (hereinafter also simply referred to as "ethylene polymer") or a polymer having structural units derived from propylene as the main structural unit (hereinafter also simply referred to as "propylene polymer").

[0019] <Ethylene-based polymer> Examples of ethylene-based polymers include copolymers of ethylene and an α-olefin having 3 to 8 carbon atoms. Examples of the α-olefin having 3 to 8 carbon atoms copolymerizable with ethylene include propylene, butene-1, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, 3-methylpentene-1, 4-methylpentene-1, 3,3-dimethylbutene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpentene-1, ethylhexene-1, methylethylpentene-1, diethylbutene-1, and propylpentene-1. Of these, propylene, 1-butene, 1-hexene, and 1-octene are preferred, propylene, 1-butene, and 1-octene are more preferred, propylene and 1-butene are even more preferred, and propylene is particularly preferred. Examples of such ethylene polymers include polyethylene, ethylene-propylene copolymer, ethylene-1-butene copolymer (EBR), ethylene-1-hexene copolymer, ethylene-1-octene copolymer (EOR), ethylene-4-methyl-1-pentene copolymer, and ethylene-propylene-1-butene copolymer.

[0020] The ethylene-based polymer preferably has structural units derived from ethylene in a range of 51 to 90 mol %, more preferably in a range of 51 to 85 mol %, and even more preferably in a range of 55 to 80 mol %, based on the number of moles of all structural units contained in the ethylene-based polymer.

[0021] Furthermore, the ethylene-based polymer preferably contains an α-olefin having 3 to 8 carbon atoms in an amount of 10 to 49 mol%, more preferably 15 to 49 mol%, and even more preferably 29 to 45 mol%, based on the number of moles of all structural units contained in the ethylene-based polymer.

[0022] Preferred examples of ethylene polymers include polyethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), linear medium density polyethylene (LMDPE), and medium density polyethylene (MDPE), as well as ethylene-vinyl acetate copolymer (EVA), which may be used alone or in combination of two or more.

[0023] Linear low-density polyethylene (LLDPE) is produced by copolymerizing ethylene monomer as the main component with an α-olefin such as butene-1, hexene-1, octene-1, or 4-methylpentene as a comonomer, using a low-pressure radical polymerization method with a single-site catalyst. The comonomer content in LLDPE is preferably in the range of 0.5 to 20 mol%, and more preferably in the range of 1 to 18 mol%.

[0024] The low density polyethylene (LDPE) may be a branched low density polyethylene obtained by high pressure radical polymerization, and is preferably a branched low density polyethylene obtained by homopolymerizing ethylene by high pressure radical polymerization.

[0025] Examples of the single-site catalyst include various single-site catalysts, such as metallocene catalyst systems that combine a metallocene compound of a transition metal of Group IV or V of the periodic table with an organoaluminum compound and / or an ionic compound. Single-site catalysts have uniform active sites, and therefore, compared with multi-site catalysts with non-uniform active sites, the molecular weight distribution of the resulting resin is sharper. This makes them preferable because, when formed into a film, there is less precipitation of low-molecular-weight components, and a resin with excellent physical properties, such as stable lamination strength and excellent blocking resistance, can be obtained.

[0026] The density of ethylene polymers is 0.880 to 0.960 g / cm 3It is preferable that the density is within this range. If the density is within this range, the polymer has appropriate rigidity and excellent mechanical strength such as pinhole resistance, and the film formability and extrusion suitability are improved. In addition, the melting point is generally preferably within the range of 60 to 130°C, more preferably 70 to 120°C. If the melting point is within this range, the processing stability (dead hold property) and co-extrusion processability are improved. Furthermore, the MFR (190°C, 21.18N) of the ethylene polymer is preferably 0.1 to 20 g / 10 min, more preferably 0.5 to 10 g / 10 min. If the MFR is within this range, the extrusion moldability of the film is improved.

[0027] <Propylene-based polymer> Examples of propylene-based polymers include propylene-1-butene random copolymers, propylene-4-methyl-1-pentene random copolymers, propylene-ethylene random copolymers, propylene-1-octene random copolymers, and propylene homopolymers. The olefin polymer (a) of the present invention may be any of the above-mentioned various polymers, but among these, the above-mentioned propylene-based polymers are preferred.

[0028] The content of the structural units constituting the olefin polymer (a) is, for example, 13 It can be measured by C-NMR.

[0029] The olefin polymer (a) preferably has an intrinsic viscosity [η] measured in decalin solvent at 135°C in the range of 0.05 to 15 dL / g, more preferably in the range of 0.1 to 10 dL / g, and even more preferably in the range of 0.5 to 3 dL / g.

[0030] The olefin polymer (a) preferably has a melt flow rate (MFR) measured at 190°C under a load of 2.16 kgf in the range of 0.01 to 200 g / 10 min, more preferably in the range of 0.1 to 180 g / 10 min, and even more preferably in the range of 1 to 150 g / 10 min.

[0031] The olefin polymer (a) can be prepared by a conventionally known method, and commercially available polyolefins may also be used. In the polar polymer composition of the present invention, the blending ratio of the olefin polymer (a) is 50 to 10 mass % or more, preferably 0.5 to 8 mass %, and more preferably 0.8 to 6 mass %. (However, the total of (a), (b) below, (c) below, and (d) below shall be 100% by mass.)

[0032] <<Polar polymer (b)>> The polar polymer (b) is preferably at least one selected from the group consisting of polyamide resins, polyester resins, and ethylene-vinyl alcohol copolymers.

[0033] <Polyamide resin> Known polyamide resins can be used, including, for example, polymers of one or more amino acid monomers selected from compounds having amino and carboxy groups and dehydration condensates thereof, copolymers of diamines and dicarboxylic acids, and copolymers of the amino acid monomers, diamines, and dicarboxylic acids.

[0034] Examples of the amino acid monomer include amino acids such as aminocaproic acid, aminoundecanoic acid, aminododecanoic acid, and paraaminomethylbenzoic acid, and lactams such as ε-caprolactam, undecanelactam, and ω-lauryllactam. One or more of the amino acid monomers can be used.

[0035] Examples of diamines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17- Examples of the diamine include aliphatic diamines such as diaminoheptadecane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, 2-methyl-1,5-diaminopentane (2M-5), and 2-methyl-1,8-diaminooctane (2M-8); alicyclic diamines such as cyclohexanediamine and bis-(4-aminocyclohexyl)methane; and aromatic diamines such as xylylenediamine (p-phenylenediamine, m-phenylenediamine, etc.). One or more types of diamines can be used.

[0036] Examples of dicarboxylic acids include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassicic acid, tetradecanedioic acid, pentadecanedioic acid, and octadecanedioic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. One or more types of dicarboxylic acids can be used.

[0037] Specific preferred polyamide resins include nylon 6, nylon 66, nylon 610, nylon 11, nylon 612, nylon 12, nylon 46, nylon MXD6, polyhexamethylene terephthalamide, polyhexamethylene (terephthalamide-isophthalamide) (copolymer), polyhexamethylene (terephthalamide-adipamide) (copolymer), polymetaphenylene isophthalamide (meta-aramid), polyparaphenylene terephthalamide (para-aramid), etc. Aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 11, nylon 612, and nylon 12 are particularly preferred.

[0038] These polyamide resins also preferably have a molecular weight sufficient to form a film, and it is desirable that the intrinsic relative viscosity [η] measured in concentrated sulfuric acid at 30°C is 0.5 dL / g or more, preferably 0.8 dL / g or more, and particularly 1.0 dL / g or more. One or more types of polyamide resins can be used.

[0039] <Polyester resin> The polyester resin used in the present invention can be produced by polymerizing a monomer containing a dicarboxylic acid and a diol in the presence of a known catalyst for polymerizing polyester resins, such as an antimony catalyst, a germanium catalyst, or a titanium catalyst.

[0040] Representative examples of dicarboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, phthalic acid, diphenic acid, and their ester derivatives; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, dodecadionic acid, eicosanoic acid, dimer acid, and their ester derivatives; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and its ester derivatives; and polyfunctional acids such as trimellitic acid, pyromellitic acid, and their ester derivatives.

[0041] Representative examples of the diol component include ethylene glycol, propanediol, butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, tetramethylene glycol, polyethylene glycol, and polyethers such as polytetramethylene glycol.

[0042] The polyester resin used in the present invention is preferably a polyester having polyethylene terephthalate as a basic component, taking into consideration mechanical strength, heat resistance, production costs, and the like.

[0043] Ethylene-vinyl alcohol copolymer (EVOH) The ethylene-vinyl alcohol copolymer (EVOH) may be, for example, a saponified copolymer obtained by saponifying an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 24 to 50 mol%, to a degree of saponification of 96 mol% or more, particularly 99 mol% or more. This saponified ethylene-vinyl alcohol copolymer preferably has a molecular weight sufficient to form a film, and generally has an MFR of 0.1 to 50 g / 10 min, particularly 0.5 to 20 g / 10 min, measured at 190°C under a load of 2.16 kg. Ethylene-vinyl alcohol copolymer (EVOH) may be used alone or in combination with two or more types of vinyl esters, ethylene unit contents, physical properties, etc.

[0044] In the polar polymer composition of the present invention, the blending ratio of the polar polymer (b) is 0.1 to 50% by mass, preferably 1.0 to 30% by mass, and more preferably 3.0 to 20% by mass.

[0045] If the blending ratio of the polar polymer (b) is too low, the gas barrier properties when molded into a film or other article tend to be insufficient, whereas if the blending ratio is too high, the recyclability tends to be insufficient.

[0046] <<Modified propylene polymer (c)>> The modified propylene polymer (c) is a component that improves the interactivity between the olefin polymer (a) and the polar polymer (b) (for example, it acts as a compatibilizer between the olefin polymer (a) and the polar polymer (b) to enhance the compatibility between the components), and improves the gas barrier properties, mechanical strength, etc. of a molded product such as a film made from the polar polymer composition of the present invention.

[0047] The modified propylene polymer (c) is a modified propylene polymer obtained by graft-modifying at least one polymer selected from the group consisting of propylene homopolymers and copolymers of propylene with at least one comonomer selected from ethylene and α-olefins having 4 to 20 carbon atoms with an unsaturated carboxylic acid or a derivative thereof. The modified propylene polymer (c) is a modified polymer obtained by modifying the propylene polymer of the olefin polymer (a) with one or more components selected from unsaturated carboxylic acids and derivatives thereof. The olefin polymer (a) constituting the polar polymer composition of the present invention and the propylene polymer before being graft-modified to the modified propylene polymer (c) may be different from each other, or may be the same in part or in whole.

[0048] The above propylene polymers can be used alone or in combination of two or more, as required.

[0049] Various known methods can be used to graft an unsaturated carboxylic acid or its derivative onto a propylene-based polymer. Specifically, examples include a method in which a propylene-based polymer is melted using an extruder, an unsaturated carboxylic acid or its derivative is added thereto, and a graft reaction is carried out (melt kneading method), or a method in which a propylene-based polymer is dissolved in a solvent to form a solution, an unsaturated carboxylic acid or its derivative is added thereto, and a graft reaction is carried out (solution method). In either case, in order to efficiently graft copolymerize the unsaturated carboxylic acid or its derivative, it is preferable to carry out the graft reaction in the presence of a radical initiator. The graft reaction is usually carried out under conditions of 60 to 350°C. The radical initiator is usually used in an amount of 0.001 to 1 part by mass per 100 parts by mass of the propylene-based polymer before modification.

[0050] The content (graft amount (degree of modification)) of one or more components selected from the unsaturated carboxylic acids and derivatives thereof in the modified propylene polymer (c) can be adjusted by adjusting the amount of the component and the ratio of the radical initiator in the reaction system during graft polymerization, as well as by adjusting the reaction temperature, etc.

[0051] Examples of the solvent used in the solution method include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, heptane, octane, and decane; alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; chlorinated hydrocarbon solvents such as trichloroethylene, perchloroethylene, dichloroethylene, dichloroethane, and chlorobenzene; aliphatic alcohol solvents such as ethanol and isopropanol; ketone solvents such as acetone, methyl isobutyl ketone, and methyl ethyl ketone; and ester solvents such as methyl acetate, ethyl acetate, and butyl acetate. One or more types of solvents can be used.

[0052] Examples of the radical initiator include organic peroxides and azo compounds. Examples of organic peroxides include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-trioyl peroxide, di-t-butyl peroxide, dicumyl peroxide, (2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, lauroyl peroxide, t-butyl peroxyacetate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, t-butyl peroxyisobutyrate, t-butyl peroxyphenyl acetate, t-butyl peroxy-s-octate, t-butyl peroxypivalate, cumyl peroxypivalate, and t-butyl peroxyethyl acetate. Examples of azo compounds include azoisobutyronitrile and dimethyl azoisobutyrate. One or more types of radical initiators can be used.

[0053] The modified propylene polymer (c) can also be obtained by copolymerizing, for example, propylene, or propylene together with ethylene or other α-olefins, and one or more components selected from unsaturated carboxylic acids and their derivatives. The other α-olefins can be the α-olefins used to form the propylene polymers described above. The copolymerization method can be, for example, a conventionally known radical copolymerization method.

[0054] The modified propylene polymer (c) is preferably a propylene polymer modified with maleic acid or maleic anhydride, and more preferably a propylene polymer modified with maleic acid or maleic anhydride. Suitable examples of the propylene polymer to which maleic acid or maleic anhydride is grafted include propylene random copolymer (rPP), propylene ethylene copolymer (PER), and homopolypropylene (hPP). The modified propylene polymer (c) can be used alone or in combination of two or more.

[0055] 《Density [kg / m 3 ]》 The density of the modified propylene polymer (c) is 890 kg / m 3 It is characterized by being less than 850 kg / m 3 More than 890kg / m 3 Preferably less than 870 kg / m 3 More than 890kg / m 3 When the density is equal to or greater than the lower limit, the molded article containing the polar polymer composition of the present invention has excellent tensile strength at break. When the density is equal to or less than the upper limit, the molded article containing the polar polymer composition of the present invention has excellent film impact strength and tear strength.

[0056] Graft amount (modification degree) [mass%] The content of the structure derived from one or more components selected from unsaturated carboxylic acids and derivatives thereof in the modified propylene polymer (c) (graft amount (degree of modification)) is 0.4 mass% or more, preferably 0.4 to 5.0 mass%, and more preferably 0.4 to 4.0 mass%. When the graft amount (degree of modification) is equal to or greater than the lower limit, the molded article containing the polar polymer composition of the present invention is excellent in mechanical properties (tensile strength at break, film impact) and transparency (internal haze). When the graft amount (degree of modification) is equal to or less than the upper limit, the molded article containing the polar polymer composition of the present invention is excellent in film appearance (black spots, gels).

[0057] <Melt flow rate (MFR) [g / 10 min]> The melt flow rate (MFR: 190°C, 2.16 kg) of the modified propylene polymer (c) is 0.1 g / 10 min or more and less than 500 g / 10 min, more preferably 1 to 300 g / 10 min.

[0058] In the polar polymer composition of the present invention, the blending ratio of the modified propylene polymer (c) is 0.1 mass % or more and less than 10 mass %, preferably 0.5 to 8 mass %, and more preferably 0.8 to 6 mass %.

[0059] <<Modified propylene polymer (d)>> The modified olefin polymer (d) is a modified polymer obtained by graft-modifying an olefin polymer with an unsaturated carboxylic acid or a derivative thereof, and the graft amount (modification degree) due to the modification is less than 0.4 mass %. The modified propylene polymer (d) is preferably further blended into a polar polymer composition comprising the olefin polymer (a), the polar polymer (b), and the modified propylene polymer (c). Molded articles such as films obtained by molding the polar polymer composition obtained by this blending exhibit excellent effects such as improved impact resistance and fatigue recovery resistance.

[0060] The modified propylene polymer (d) is a modified propylene polymer obtained by graft-modifying at least one polymer selected from the group consisting of propylene homopolymers and copolymers of propylene with at least one comonomer selected from ethylene and α-olefins having 3 to 20 carbon atoms with an unsaturated carboxylic acid or a derivative thereof. In this respect, it is similar to the above-mentioned modified propylene polymer (c) and is produced in the same manner as above, but its physical properties are different from those of the above-mentioned modified propylene polymer (c), as will be described below. The olefin polymer (a) constituting the polar polymer composition of the present invention and the propylene polymer before being graft-modified to the modified propylene polymer (d) may be different from each other, or part or all of them may be the same.

[0061] Graft amount (modification degree) [mass%] The modified propylene polymer (d) has a graft amount (modification degree) of less than 0.4% by mass, preferably 0.05% by mass or more and less than 0.4% by mass. When the graft amount (modification degree) is equal to or greater than the lower limit, the molded article containing the polar polymer composition of the present invention has excellent mechanical properties (tensile strength at break, film impact) and transparency (internal haze). When the graft amount (modification degree) is equal to or less than the upper limit, the molded article containing the polar polymer composition of the present invention has excellent film appearance (black spots, gels). Thus, the modified propylene polymer (d) is a modified polymer that is clearly different in graft amount (degree of modification) from the above-mentioned modified propylene polymer (c). In particular, the difference in the graft amount (degree of modification) between the two polymers is preferably adjusted so that the ratio (degree of modification D / degree of modification C), where D is the graft amount (degree of modification) of the modified propylene polymer (d) and C is the graft amount (degree of modification) of the modified propylene polymer (c), falls within the range of 0.01 to 0.5. When the degree of modification D / degree of modification C is equal to or greater than the lower limit, the molded article containing the polar polymer composition of the present invention has excellent mechanical properties (tensile strength at break, film impact) and transparency (internal haze). When the graft amount (degree of modification) is equal to or less than the upper limit, the molded article containing the polar polymer composition of the present invention has excellent film appearance (black spots, gels).

[0062] <Melt flow rate (MFR) [g / 10 min]> The melt flow rate (MFR: 190° C., 2.16 kg) of the modified propylene polymer (d) is preferably 0.1 to 15 g / 10 min.

[0063] 《Density [kg / m 3 ]》 The density of the modified propylene polymer (d) is 860 to 920 kg / m 3 is preferable, and more preferably 880 kg / m 3 More than 910kg / m 3 Less than is preferred.

[0064] In the polar polymer composition of the present invention, the blending ratio of the modified propylene polymer (d) is preferably 0.1 to 50 mass %, more preferably 0.5 to 20 mass %, and even more preferably 0.8 to 10 mass %. (The total of (a), (b), (c), and (d) is 100% by mass.)

[0065] In addition to the olefin polymer (a), the polar polymer (b), the acid-modified propylene polymer (c), and the acid-modified olefin polymer (d), various additives, stabilizers, colorants, dyes, and the like may be blended into the polar polymer composition of the present invention, as needed. Examples of additives include antioxidants, UV absorbers, weather stabilizers, antistatic agents, plasticizers, lubricants, and antistatic agents. The total content of these additives in the polar polymer composition of the present invention is usually 20% by mass or less, preferably 10% by mass or less, and more preferably 5% by mass or less.

[0066] Preparation of Polar Polymer Composition The polar polymer composition of the present invention can be prepared by mixing the above-mentioned components by melt kneading, etc. The order and method of mixing are not particularly limited, and various conventionally known methods can be used.

[0067] <<Molded body>> The polar polymer composition of the present invention can be used to produce a variety of molded articles, including films, containers such as bottles and tubes, and fibers, by various molding methods such as extrusion and blowing. The molded articles may be stretched depending on the intended use. Examples of stretching methods include roll stretching, tenter stretching, tubular stretching, and stretch-blow, and for films, uniaxial stretching and biaxial stretching (simultaneous biaxial stretching and sequential biaxial stretching) can be used.

[0068] The film made of the polar polymer composition of the present invention can be used as a single layer film or as a multilayer film containing the same layer for various purposes such as packaging materials for foods, cosmetics, medicines, etc. Examples of layers constituting the multilayer film include an adhesive propylene polymer layer, a gas barrier layer made of a polar polymer (b) such as a polyamide resin, a polyester resin, or an ethylene-vinyl alcohol copolymer, and a gas barrier layer made of a metal foil.

[0069] <Regrind layer> A multilayer film that has already been formed may be reused as a regrind layer to form a multilayer film again. When a multilayer film is composed entirely of an olefin polymer (a) and a polar polymer (b), or when a modified propylene polymer (c) and / or a modified olefin polymer (d) is further blended with these, and when the film is used as a regrind layer to form a multilayer film containing a regrind layer, by blending the modified propylene polymer (c) and / or the modified olefin polymer (d) into the regrind layer and configuring the regrind layer to be the polar polymer composition of the present invention, it is possible to improve the impact resistance, fatigue recovery resistance, etc.

[0070] Multilayer films containing a regrind layer made of the polar polymer composition of the present invention can be produced in the same manner as conventional multilayer films, except that the regrind layer has the composition of the present invention. Furthermore, the multilayer films can be recycled repeatedly, for example, by using a regrind layer as a regrind layer to produce a second regrind layer. Such recycled multilayer films, and the repetition of such recycled multilayer films, are comparable in performance to the original multilayer films and can be used for similar purposes.

[0071] <<Example>> The present invention will be described with reference to examples, but the present invention is not limited to these examples. The measurement and evaluation methods are shown below.

[0072] <About polymers> The properties of the polymers used in the examples were measured as follows.

[0073] <Melt flow rate (MFR) [g / 10 min]> The MFR was measured at 190°C under a load of 2.16 kg in accordance with ASTM D1238.

[0074] 《Density [kg / m 3 ]》 The density was measured in accordance with ASTM D1505 (density gradient tube method).

[0075] <Amount of structural units derived from unsaturated carboxylic acid or its derivatives (graft amount (modification degree))> The amount of structural units grafted onto the polymer and derived from an unsaturated carboxylic acid or a derivative thereof (graft amount (degree of modification)) can be calculated from the charge ratios of the modified propylene polymer (c) and the modified olefin polymer (d) when they are prepared, or can be measured using a combination of NMR and IR methods.

[0076] Specifically, this can be done in the following procedure. 1) Several samples of the modified propylene polymer (c) and the modified olefin polymer (d) with different graft amounts (degrees of modification) are prepared, and the graft amounts (degrees of modification) are measured by NMR. Furthermore, these samples are subjected to infrared spectroscopy (IR) measurement. Then, a calibration curve is created between the graft amounts (degrees of modification) obtained by NMR measurement and the intensity ratio of specific peaks in the infrared spectroscopy (IR) spectrum. 2) Next, IR measurement is carried out on each of the modified propylene polymer (c) and modified olefin polymer (d) to be measured, and the intensity ratio of specific peaks in the infrared (IR) spectrum is measured. For maleic anhydride, 1790 cm ―1 An example of such a method is to measure the intensity of the light. 3) The measurement results obtained in 2) above are compared with the calibration curve obtained in 1) above to identify the graft amount (degree of modification) of each of the modified propylene polymer (c) and modified olefin polymer (d) to be measured. In this method, it is necessary to prepare a calibration curve depending on the type of polymer and unsaturated carboxylic acid or its derivative.

[0077] The measurement conditions for the NMR method in 1) above are exemplified as follows. 1 For H-NMR measurements, a nuclear magnetic resonance spectrometer ECX400 manufactured by JEOL Ltd. was used, the solvent was deuterated orthodichlorobenzene, the sample concentration was 20 mg / 0.6 mL, the measurement temperature was 120 °C, and the observation nuclei were 1 The conditions are H (400 MHz), sequence is single pulse, pulse width is 5.12 μsec (45° pulse), repetition time is 7.0 sec, and the number of accumulations is 500 or more. The reference chemical shift is set to 0 ppm for hydrogen in tetramethylsilane, but similar results can also be obtained by setting the peak derived from residual hydrogen in deuterated orthodichlorobenzene at 7.10 ppm as the reference value for the chemical shift. 1 Peaks such as H can be assigned by conventional methods.

[0078] 13 For C-NMR measurements, a JEOL ECP500 nuclear magnetic resonance spectrometer was used, and the solvent was a mixed solvent of orthodichlorobenzene / heavy benzene (80 / 20% by volume). The measurement temperature was 120°C, and the observation nuclei were 13 The conditions were: C (125 MHz), single pulse proton decoupling, 45° pulse, repetition time 5.5 seconds, accumulation number 10,000 or more, and chemical shift reference value 27.50 ppm. Assignment of various signals was performed based on the standard method, and quantification could be performed based on the accumulated value of signal intensity.

[0079] Melting point (Tm) [℃] The melting points (Tm) of the following polymers were measured by differential scanning calorimetry (DSC) using the following method. Approximately 5 mg of a polymer sample is sealed in an aluminum pan and, using a PerkinElmer DSC8500, heated from room temperature to 230°C at a heating rate of 10°C / min, held at 230°C for 10 minutes, then cooled from 230°C to 30°C at a cooling rate of 10°C / min, held at 30°C for a further minute, and then heated again to 230°C at a heating rate of 10°C / min. The melting point (Tm) was determined from the melting peak that appeared in the endothermic curve during this process. When multiple peaks were detected during this measurement, the temperature of the largest peak was taken as the melting point (Tm) [°C].

[0080] About the film The properties of the films produced in the examples were measured and evaluated as follows.

[0081] Tensile properties Tensile strength at break [unit: MPa], tensile elongation at break [unit: %] Test pieces conforming to JIS K7127 Type 5 were cut out from the films (thickness: 50 μm) obtained in the examples, etc. Next, the tensile strength at break (unit: MPa) and tensile elongation at break (unit: %) of the test pieces were measured in accordance with JIS K7127 using a universal material testing machine "AG-X-5" manufactured by Shimadzu Corporation under conditions of a chuck distance of 80 mm, a tensile speed of 200 mm / min, and a temperature of 23°C.

[0082] Film impact strength (impact resistance) [kJ / m] Using the films (thickness 50 μm) obtained in the examples, etc., the film impact strength at 23°C was measured using a film impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with ASTM-D3420, with an impact head spherical shape of 1 inch φ.

[0083] <Tear strength [N]> Tear strength (MD direction), tear strength (TD direction) Using the films (thickness 50 μm) obtained in the examples, etc., the tear strength at 23°C was measured in each of the MD and TD directions of the film using a Digital Elmendorf Tear Tester "4N" manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K-7128-2.

[0084] <Internal Haze (Transparency) [%]> Using a haze meter "HM-150" manufactured by Murakami Color Research Laboratory Co., Ltd., measurements were carried out in cyclohexanol on the films (thickness: 50 μm) produced in the examples in accordance with JIS K7136, and the internal haze was calculated using the following formula. Internal haze (%) = 100 x (diffuse transmitted light amount) / (total transmitted light amount)

[0085] The polymers used in the examples are as follows: The modified propylene polymers (c-1), (c-2), and (c-3) and the modified olefin polymer (d-1) were produced by a method (melt kneading method) in which an unmodified propylene polymer was melted using an extruder and maleic anhydride was added thereto to cause a graft reaction. In each case, the graft reaction was carried out in the presence of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (radical initiator) at 190 to 250°C. The amount of maleic anhydride used was 0.05 to 4 parts by mass, and the amount of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (radical initiator) was 0.01 to 3 parts by mass, per 100 parts by mass of the unmodified propylene polymer. Olefin polymer (a-1) Propylene random copolymer (rPP): Prime Polymer F327 MFR (230℃, 2.16kg load) 7.0g / 10min Density 900kg / m 3 Melting point: 137°C Polar polymer (b-1) Ethylene-vinyl alcohol copolymer (EVOH): EVAL (registered trademark) F101A, manufactured by Kuraray Co., Ltd. Content of structural units derived from ethylene: 32 mol% MFR (190℃, 2.16kg load) 1.6g / 10min Melting point: 183°C. Modified propylene polymer (c-1) Maleic anhydride modified propylene ethylene copolymer (MAH-PER): MFR (190℃, 2.16kg load) 160g / 10min Density 879kg / m 3 Maleic anhydride graft amount: 1.2 mass % Melting point: 77°C Modified propylene polymer (c-2) Maleic anhydride modified homopolypropylene (MAH-hPP): MFR (190℃, 2.16kg load) 220g / 10min Density 900kg / m 3 , Maleic anhydride graft amount: 0.6% by mass Melting point: 158°C Modified propylene polymer (c-3) Maleic anhydride modified propylene random copolymer (MAH-rPP-1): MFR (190℃, 2.16kg load) 220g / 10min Density 900kg / m 3 , Maleic anhydride graft amount: 1.2 mass % Melting point: 139°C Modified olefin polymer (d-1) Maleic anhydride modified propylene random copolymer (MAH-rPP-2): MFR (230℃, 2.16kg load) 5.7g / 10min Density 890kg / m 3 , Maleic anhydride graft amount: 0.14 mass% Melting point: 138°C. The above modified olefin polymer (d-1) is a modified olefin polymer (d), and the MFR is measured at a temperature of 230°C.

[0086] Example 1 Preparation of polar polymer compositions The following three components were blended in the following mass ratio, and then melt-kneaded in a single-screw extruder (65 mmφ) set at 220° C. to prepare pellets of a polar polymer composition (one-pass product). Olefin polymer (a-1) Propylene random copolymer (rPP): 80 parts by mass Polar polymer (b-1) Ethylene-vinyl alcohol copolymer (EVOH): 10 parts by weight, Modified olefin polymer (d-1) Maleic anhydride modified propylene random copolymer (MAH-rPP-2): 10 parts by mass

[0087] The pellets of the regrind composition thus obtained were dried at 80°C overnight. Next, the dried regrind composition was further blended with the modified propylene polymer (c-1) in the mass ratio shown below, and the mixture was melt-kneaded again in the single-screw extruder under the same conditions as above to obtain a polar polymer composition (2-pass product). Dried Regrind Composition : 100 parts by mass, Modified propylene polymer (c-1) Maleic anhydride modified propylene ethylene copolymer (MAH-PER): 5 parts by mass

[0088] The above polar polymer composition (2-pass product) was fed to an extruder having a screw (40 mmφ) and extruded using a cast molding die at a resin temperature of 220°C to obtain a monolayer film with a thickness of 50 μm. The molding speed was 8 m / min. The polymers used are shown in Table 1. The evaluation results of the obtained films are shown in Table 2.

[0089] <Comparative Examples 1 to 4> A film was obtained in the same manner as in Example 1, except that the polymer used was changed as shown in Table 1. The polymers used are shown in Table 1. The evaluation results of the obtained film are shown in Table 2.

[0090] [Table 1]

[0091] [Table 2]

Claims

1. The polymer comprises an olefin polymer (a), a polar polymer (b), and a modified propylene polymer (c), The modified propylene polymer (c) is obtained by graft-modifying a propylene polymer with an unsaturated carboxylic acid or a derivative thereof, and the graft amount (modification degree) is 0.4 mass% or more, and the density is 890 kg / m 3 is less than 50% by mass or more and less than 100% by mass of an olefin polymer (a), polar polymer (b) 0.1 to 50% by mass, Modified propylene polymer (c) 0.1% by mass or more and less than 20% by mass (where the total of (a), (b) and (c) is 100% by mass) A polar polymer composition comprising:

2. Further, it contains a modified olefin polymer (d), the modified olefin polymer (d) is obtained by graft-modifying an olefin polymer with an unsaturated carboxylic acid or a derivative thereof, and the graft amount (modification degree) resulting from the modification is less than 0.4 mass%, The proportion of the modified olefin polymer (d) is 0.1 to 50% by mass. (where the total of (a), (b), (c) and (d) is 100% by mass) 2. The polar polymer composition of claim 1, wherein

3. 3. The polar polymer composition according to claim 2, wherein the modified propylene polymer (c) and the modified olefin polymer (d) are polymers defined below. Modified propylene polymer (c) Blend ratio: 0.1% by mass or more, less than 20% by mass Graft amount (modification degree): 0.4 to 5.0 mass% Melt flow rate (MFR: 190°C, 2.16 kg) 0.1g / 10min or more, less than 500g / 10min Density 860kg / m 3 Above, 890kg / m 3 less than Modified olefin polymer (d) Blending ratio 0.1-50% by mass Graft amount (modification degree): 0.01% by mass or more and less than 0.4% by mass Melt flow rate (MFR: 190°C, 2.16 kg) 0.1g / 10min or more, less than 15g / 10min Density 860-960 kg / m 3

4. 2. The polar polymer composition of claim 1, wherein the unsaturated carboxylic acid or derivative thereof is maleic anhydride.

5. 3. The polar polymer composition of claim 2, wherein the unsaturated carboxylic acid or derivative thereof is maleic anhydride.

6. 2. The polar polymer composition according to claim 1, wherein the polar polymer (b) comprises at least one polar polymer selected from the group consisting of polyamide resins, polyester resins, and ethylene-vinyl alcohol copolymers.

7. A molded article comprising the polar polymer composition according to any one of claims 1 to 6.

8. A single-layer or multi-layer film comprising at least one layer comprising the polar polymer composition according to any one of claims 1 to 6.

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