Polar group-containing olefin copolymer

Abstract

To provide a polar group-containing olefin copolymer having high strain hardenability and excellent moldability.SOLUTION: A polar group-containing olefin copolymer comprises: a structural unit (A) derived from at least one selected from a group consisting of ethylene and a 3-20C α-olefin; a structural unit (B) having at least one selected from a group consisting of a carboxy group and a dicarboxylic acid anhydride group; and a structural unit (C) having a carboxylic acid metal salt group in which the metal contains a metal element M1 having Pauling's electronegativity χ of 1.83 or more, and numbers of methyl branches calculated by 13C-NMR is 50 or less per 1,000 carbon atoms, or the sum total of numbers of ethyl branches and numbers of butyl branches is less than 4.2 per 1,000 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polar group-containing olefin copolymer, more particularly to an ethylene-based ionomer, and still more particularly to a polar group-containing olefin copolymer having an excellent balance between fluidity and strain hardening properties and good moldability. [Background technology]

[0002] Ethylene-based ionomers, which are polar group-containing olefin copolymers, are resins that use an ethylene-unsaturated carboxylic acid (or dicarboxylic anhydride) copolymer as the base resin and are intermolecularly bonded by metal ions such as sodium, magnesium, and zinc. They are characterized by being strong, rigid, and highly transparent (Patent Document 1). Ethylene-unsaturated carboxylic acid copolymers (acid copolymers) produced by high-pressure radical polymerization inherently possess strain hardening properties, but it is also known that by converting the acid copolymer into an ionomer with zinc, sodium, or magnesium ions, the strain hardening properties are improved due to the presence of these intermolecular bonds (Non-Patent Document 1).

[0003] Currently, commercially available ethylene-based ionomers include "Surlyn®," a sodium or zinc salt of ethylene-methacrylic acid copolymer developed by DuPont, and "Himilan®," sold by Mitsui-Dow Polychemicals. These ethylene-based ionomers all use a base resin obtained by polymerizing ethylene and polar group-containing monomers such as unsaturated carboxylic acids using high-pressure radical polymerization. The molecular structure of copolymers produced by high-pressure radical polymerization is known to have numerous irregular long-chain and short-chain branches, as shown in the image in Figure 1. This structure results in insufficient strength and impact resistance.

[0004] In recent years, to overcome this drawback, other methods have been reported for producing acid copolymers that serve as the base resins (raw materials) of ethylene-based ionomers, and the olefin copolymers that serve as the raw materials. These methods involve using a late transition metal catalyst to produce a copolymer of ethylene and t-butyl acrylate, modifying the resulting copolymer into an ethylene-acrylic acid copolymer by heat or acid treatment, and then reacting it with metal ions such as sodium or zinc to produce an ethylene-based ionomer (Patent Documents 2 and 3).

[0005] Furthermore, it has been reported that an ethylene-based ionomer using magnesium as the metal ion was produced by graft-modifying an ethylene-cyclic olefin copolymer (COC) with maleic anhydride and then reacting it with magnesium stearate (Patent Document 4).

[0006] On the other hand, Pauling's electronegativity is known as an index for estimating the bond enthalpy between atoms of elements with different electronegativities and for qualitatively evaluating the polarity of bonds. Furthermore, Pauling's electronegativity has been further developed to use the difference in electronegativity (Δχ) and the average electronegativity (χ ) of the elements in a compound as an index for classifying binary compounds into ionic, covalent, or metallic bonding. 平均 ) is known (Non-Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 3,264,272 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-79408 [Patent Document 3] Japanese Patent Publication No. 2020-143276 [Patent Document 4] Japanese Patent Publication No. 2020-158682 [Non-patent literature]

[0008] [Non-Patent Document 1] Polymer,vol.35,no.26,P5722-5727,1994 [Non-patent document 2] Shriver-Atkins Inorganic Chemistry (Vol. 1), Tokyo Kagaku Dojin, 6th edition, 2016, p. 69 [Non-patent document 3] J.Phys.Chem.,vol.98,no.27,P6699-6703,1994 [Non-patent document 4] LAUTRACKI, "Polymer Alloys and Polymer Blends", Tokyo Kagaku Dojin, 1st edition, 1991, pp. 262-265 [Non-Patent Document 5] Journal of the Japanese Society of Rheology, vol.19,1991,pp.174-180 Summary of the Invention [Problem to be solved by the invention]

[0009] There is a demand for polar group-containing olefin copolymers that exhibit excellent moldability while maintaining excellent properties such as mechanical strength and transparency. The ionomers disclosed in Patent Document 1 and Non-Patent Document 1 are produced by high-pressure radical polymerization, and further improvements in strength and impact resistance are required.

[0010] In Patent Document 2, an ionomer having excellent thermal properties, mechanical strength, etc. is obtained because the base resin is an ethylene / unsaturated carboxylic acid ester copolymer produced using a late transition metal catalyst and having a substantially linear structure. However, as the metal ions constituting the ionomer, the focus is on metal ions of Groups 1, 2, and 12 of the periodic table, and only sodium ionomers have been substantially investigated, and there is no description regarding the effects on the physical properties of ionomers containing metal ions other than these.

[0011] Patent Document 3 describes a ternary ionomer obtained using a late transition metal catalyst, with a multicomponent copolymer having a substantially linear structure and a structural unit (B) derived from a monomer having at least one selected from the group consisting of a carboxyl group and a dicarboxylic acid anhydride group as the base resin, and describes that the ternary ionomer has excellent tensile strength, transparency, and metal adhesion. However, the metal ions constituting the ionomer are those of Groups 1, 2, and 12 of the periodic table, and only sodium and zinc ionomers have been substantially investigated, with no description of the effects on the physical properties of ionomers containing metal ions other than these.

[0012] Patent Document 4 describes that an ionomer is obtained using a maleic anhydride graft modified ethylene-cyclic olefin copolymer (COC) as the base resin, and that the ionomer has excellent high-temperature dimensional stability and transparency. However, only potassium and magnesium ionomers have been substantially investigated, and there is no description of the effects on the physical properties of ionomers containing metal ions other than these.

[0013] The ionomers disclosed in Patent Documents 2 to 4 are excellent in mechanical strength and transparency, but may cause localized thinning during molding processes such as blow molding and film molding, and further improvement in moldability is desired.

[0014] In view of the above-described state of the art, an object of the present invention is to provide a polar group-containing olefin copolymer that exhibits high strain hardening properties and excellent moldability. [Means for solving the problem]

[0015] The present inventors considered that it was necessary to enhance the strain hardening of polar group-containing olefin copolymers in order to prevent localized thinning during molding, to make the wall thickness of molded articles uniform, and to improve moldability. As a result of extensive research aimed at enhancing the strain hardening of such copolymers, they found that specific polar group-containing olefin copolymers containing metal atoms and having a Pauling electronegativity χ of 1.83 or more have significantly superior strain hardening properties compared to conventional ionomers, leading to the present invention.

[0016] That is, the present invention relates to the following [1] to [9]. [1] A structural unit (A) derived from at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and a structural unit (C) having a carboxylate metal salt group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 and a structural unit (C) comprising: 13 A polar group-containing olefin copolymer in which the number of methyl branches is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms, as calculated by C-NMR. [2] The polar group-containing olefin copolymer according to [1], wherein the structural unit (C) is represented by the following formula (1): -(CH2CR 1 T 1 )-...Equation (1) [In formula (1), R 1 represents a hydrogen atom; a halogen atom; a carboxy group; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one halogen atom; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one carboxy group; or a hydrocarbon group having 1 to 10 carbon atoms, T 1 is the metal atom M 1 a metal carboxylate base having the metal atom M 1represents a hydrocarbon group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, a substituted amino group having 1 to 12 carbon atoms, or a substituted silyl group having 1 to 18 carbon atoms, each of which is substituted with at least one metal carboxylate salt group having the formula: [3] The polar group-containing olefin copolymer according to [1] or [2], wherein the χ is 1.83 to 2.36. [4] The metal atom M 1 is at least one selected from the group consisting of Fe, Co, Cu, Ni, Ge, Tc, Mo, Rh, Pd, Ag, Sn, Sb, Re, Os, Ir, Pt, Hg, Pb, Bi, and Po. [5] The polar group-containing olefin copolymer according to any one of [1] to [4], wherein the ratio of the molar content of the structural unit (C) to the total molar content of the structural unit (B) and the structural unit (C) is 1 to 99 mol%. [6] The polar group-containing olefin copolymer according to any one of [1] to [5], wherein the ratio of the sum of the molar contents of the structural unit (B) and the structural unit (C) to the sum of the molar contents of each structural unit in the polar group-containing olefin copolymer is 0.01 to 20.00 mol %. [7] The polar group-containing olefin copolymer according to any one of [1] to [6], wherein the structural unit (A) is a structural unit derived from ethylene. [8] An olefin resin composition comprising the polar group-containing olefin copolymer according to any one of [1] to [7]. [9] A molded article comprising the olefin resin composition according to [8]. [Effects of the Invention]

[0017] According to the present invention, by using a polar group-containing olefin copolymer having a substantially linear structure and containing a metal atom with a Pauling electronegativity χ of 1.83 or more, it is possible to provide a polar group-containing olefin copolymer that exhibits higher strain hardening properties and excellent moldability compared to conventional ionomers. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an image of the molecular structure of a hyperbranched olefin copolymer polymerized by a high-pressure radical polymerization process. [Figure 2] FIG. 1 is an image of the molecular structure of a linear olefin copolymer polymerized using a metal catalyst. DETAILED DESCRIPTION OF THE INVENTION

[0019] The polar group-containing olefin copolymer comprises a structural unit (A) derived from at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and a structural unit (C) having a carboxylic acid metal salt group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 and a structural unit (C) comprising: 13 The number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms. The polar group-containing olefin copolymer has high strain hardening properties and exhibits excellent moldability, and the molded articles obtained have good properties such as mechanical strength and transparency.

[0020] One embodiment of the present invention is a polymerizable compound having a structural unit (A) derived from ethylene, a structural unit (B) having a carboxy group, and the above metal atom M 1 and a structural unit (C) having a carboxylic acid metal salt group, wherein R is Fe, Ag, or Pb. In another embodiment of the present invention, in the polar group-containing olefin copolymer, the mole number of structural unit (C) / {mol number of structural unit (B)+mol number of structural unit (C)} is 10 to 65% or 10 to 45%.

[0021] The polar group-containing olefin copolymer of the present invention will be described in detail below for each item. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid. In this specification, the symbol "to" indicating a numerical range is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. In this specification, the term "copolymer" means a binary or higher copolymer containing at least one structural unit (A) and at least one structural unit (B). The polar group-containing olefin copolymer comprises the structural unit (A), the structural unit (B), and a structural unit (C) having a metal carboxylate group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 and a structural unit (C) containing the following. Each structural unit may be of one type or of multiple types. The polar group-containing olefin copolymer may further contain other structural units. In this specification, the polar group-containing olefin copolymer of the present invention may also be referred to as an ionomer. Furthermore, in this specification, the term "raw copolymer" refers to the raw copolymer when the polar group-containing olefin copolymer is obtained by modifying a raw copolymer containing at least one structural unit (A) and at least one structural unit having an alkoxycarbonyl group or at least one structural unit (B). In addition, in this specification, the terms "n-" (normal), "i-" (iso), and "t-" (tertiary) are used to represent isomers. In this specification, Pauling's electronegativity refers to the "Pauling value" in Tables 1 and 4 of "Basic Inorganic Chemistry, 2nd Edition" (Tokyo Kagaku Dojin Publishing, Hiroshi Ogino, Hiromi Tobita, Masaaki Okazaki, published September 12, 2006), p. 30.

[0022] 1. Polar group-containing olefin copolymer The polar group-containing olefin copolymer comprises a structural unit (A) derived from at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and a structural unit (C) having a carboxylic acid metal salt group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 and a structural unit (C) comprising: 13 The number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms. Examples of the polar group include a carboxy group, a hydroxy group, a mercapto group, an amino group, an amide group, an alkoxy group, and a cyano group, with a carboxy group being preferred.

[0023] (1) Structural unit (A) The structural unit (A) is a structural unit derived from at least one selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms. α-olefins have the structural formula (2): CH2=CHR 2 is an α-olefin having 3 to 20 carbon atoms (R 2 is a hydrocarbon group having 1 to 18 carbon atoms, which may have a linear or branched structure. The α-olefin more preferably has 3 to 12 carbon atoms.

[0024] Specific examples of the monomer from which the structural unit (A) is derived include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 3-methyl-1-butene, and 4-methyl-1-pentene, and may be ethylene. As the ethylene, ethylene derived from petroleum raw materials or non-petroleum raw materials such as plant raw materials can be used. The structural unit (A) may be of one type or of multiple types. Examples of combinations of the two include ethylene-propylene, ethylene-1-butene, ethylene-1-hexene, ethylene-1-octene, propylene-1-butene, propylene-1-hexene, and propylene-1-octene. Examples of combinations of the three include ethylene-propylene-1-butene, ethylene-propylene-1-hexene, ethylene-propylene-1-octene, propylene-1-butene-1-hexene, and propylene-1-butene-1-octene.

[0025] In the present invention, the monomer from which the structural unit (A) is derived is preferably ethylene, and may further contain one or more α-olefins having 3 to 20 carbon atoms, if necessary. The proportion of ethylene contained in the monomer from which the structural unit (A) is derived may be 50 to 100 mol %, 70 to 100 mol %, or 90 to 100 mol % based on the total moles of the structural unit (A). In terms of impact resistance, the structural unit (A) is preferably a structural unit derived from ethylene.

[0026] (2) Structural unit (B) The structural unit (B) is a structural unit having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group. Note that the structural unit (B) may be a structural unit derived from a monomer having at least one of a carboxy group and a dicarboxylic anhydride group, and as will be described later in the production method, it does not necessarily have to be produced using a monomer having at least one of a carboxy group and a dicarboxylic anhydride group.

[0027] Examples of monomers having a carboxy group include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, and bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic acid. Examples of monomers having a dicarboxylic acid anhydride group include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride, and tetracyclo[6.2.1.1 3,6 .0 2,7 ] Examples of the unsaturated dicarboxylic acid anhydrides include dodec-9-ene-4,5-dicarboxylic acid anhydride and 2,7-octadien-1-yl succinic acid anhydride.

[0028] As the monomer having at least one of a carboxy group and a dicarboxylic acid anhydride group, acrylic acid, methacrylic acid, or 5-norbornene-2,3-dicarboxylic acid anhydride is preferred from the viewpoint of industrial availability, with acrylic acid being particularly preferred. The monomer having at least one of a carboxy group and a dicarboxylic anhydride group may be of one type or of multiple types. The dicarboxylic anhydride group may react with moisture in the air to open the ring and convert a portion of the group into a dicarboxylic acid. However, the dicarboxylic anhydride group may be ring-opened within the scope of the present invention.

[0029] The structural unit (B) may be obtained by an elimination reaction using heat or acid. The "elimination reaction" here may be a deprotection reaction of an ester. The reaction conditions are not particularly limited as long as they are reaction conditions commonly used for deprotecting an ester. Commonly used conditions or reagents can be used as the heat or acid reaction conditions for the elimination reaction. Conditions such as temperature and reagents for the elimination reaction are well known to those skilled in the art, and they can be used in appropriate combination. The deprotection reaction of the ester may be carried out partially, in which case a structural unit having an alkoxycarbonyl group will be present in the polar group-containing olefin copolymer.

[0030] The structural unit (B) can be, for example, a compound represented by the structural formula (3): CH═C(R 31 )CO2(R 32 ) as at least one monomer, and then the resulting polymer is converted into a carboxy group by the above-mentioned thermal or acidic elimination reaction. 31 R is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms substituted with at least one halogen atom, and the hydrocarbon group may have a branch, a ring, and / or an unsaturated bond. 32 is a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a branch, a ring, and / or an unsaturated bond. 32 It may contain a heteroatom at any position within the group. As the compound represented by the above structural formula (3), R 31 is a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and R 32 is a hydrocarbon group having 1 to 10 carbon atoms. 31 is a hydrogen atom or an acrylic acid ester in which R 31 is a methyl group.

[0031] Specific examples of the compound represented by structural formula (3) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, and benzyl (meth)acrylate. Among these, the compound represented by the structural formula (3) may be methyl acrylate, ethyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, or 2-ethylhexyl acrylate, and is particularly preferably n-butyl acrylate, i-butyl acrylate, or t-butyl acrylate. The compound represented by the structural formula (3) may be one type or multiple types.

[0032] Furthermore, the structural unit (B) may be one obtained by polymerizing a compound represented by the following formula (4) as at least one monomer. H2C=CR 4 -T 2 ···(4) [In formula (4), R 4 represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms substituted with at least one halogen atom, T 2is a carboxy group, an alkoxycarbonyl group having 2 to 20 carbon atoms and substituted with one or more carboxy groups, a hydrocarbon group having 1 to 30 carbon atoms and substituted with one or more carboxy groups, an alkoxy group having 1 to 20 carbon atoms and substituted with one or more carboxy groups, an acyloxy group having 2 to 20 carbon atoms and substituted with one or more carboxy groups, a substituted amino group having 1 to 12 carbon atoms and substituted with one or more carboxy groups, or a substituted silyl group having 1 to 18 carbon atoms and substituted with one or more carboxy groups.

[0033] The substituted amino group may be a mono-substituted amino group or a di-substituted amino group. In the case of a di-substituted amino group, each substituent is a hydrocarbon group having 1 to 12 carbon atoms, and preferably a hydrocarbon group having 1 to 6 carbon atoms. The substituted silyl group may be a mono-, di-, or tri-substituted silyl group. In the case of a di- or tri-substituted silyl group, each substituent is a hydrocarbon group having 1 to 18 carbon atoms, and preferably a hydrocarbon group having 1 to 6 carbon atoms. Among them, R 4 is preferably a hydrogen atom or a methyl group, and T 2 is preferably a carboxy group. The structural unit (B) may be of a single type or of multiple types, and the above-mentioned monomers may be used alone or in combination of two or more types.

[0034] (3) Structural unit (C) The structural unit (C) is a structural unit having a metal carboxylate group, and the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 It is a structural unit containing

[0035] It is believed that the carboxylate metal salt is involved in the formation of intermolecular bonds between polymers in polar group-containing olefin copolymers. The stronger the intermolecular bonds, the more favorable they are for the development of strain hardening properties, which in turn favors improved moldability. For example, in the case of an ethylene-unsaturated carboxylic acid copolymer (including cases where the carboxylic acid of the unsaturated carboxylic acid is a carboxylate), the intermolecular bonds are formed between oxygen atoms and metal atoms in the ethylene-unsaturated carboxylic acid copolymer, and the strength of the bonds can be estimated from the electronegativity of the oxygen atom and the metal atom, respectively. For example, in Non-Patent Document 2, the bonding pattern between two atoms is calculated by using Pauling's electronegativity χ and the average electronegativity difference (Δχ). 平均 ) According to this knowledge, the bonding mode between a metal atom and an oxygen atom is thought to be ionic when the χ value of the metal is less than 1.83, while it is covalent when the χ value is 1.83 or more. In general, the bond strength is stronger in covalent bonds than in ionic bonds. The relationship between the bonding mode and electronegativity between two atoms has also been reported in Non-Patent Document 3 (when the difference in Pauling's electronegativity χ between two atoms exceeds 1.7, it is ionic, and when it is less than that, it is covalent). That is, the metal species of the carboxylic acid metal base is a metal atom M with a Pauling electronegativity χ of 1.83 or more. 1 By including the oxygen atom (χ: 3.44) and the metal atom M, the bond between the polymers described above becomes covalent, which strengthens the bond and contributes to the development of strain hardening. 1 The Δχ between these two is 1.61 or less, which is smaller than 1.7, and is consistent with Non-Patent Document 3. A preferred χ is 1.83 to 2.36, and more preferably 1.88 to 2.36. Furthermore, since it may be better if the bond is not completely covalent, χ is preferably 1.83 to 2.33, more preferably 1.83 to 2.30, even more preferably 1.83 to 2.20, even more preferably 1.85 to 2.10, and particularly preferably 1.88 to 2.03.

[0036] Specific metal atom M1 Examples of such elements include iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), mercury (Hg), germanium (Ge), tin (Sn), antimony (Sb), lead (Pb), bismuth (Bi), polonium (Po), and astatine (At). Among these, from the viewpoint of ease of handling, at least one selected from the group consisting of Fe, Co, Cu, Ni, Ge, Tc, Mo, Rh, Pd, Ag, Sn, Sb, Re, Os, Ir, Pt, Hg, Pb, Bi and Po is more preferred, and Fe, Ag and Pb are particularly preferred. In addition, the metal atom M 1 may be one type or multiple types.

[0037] The metal in the carboxylate metal salt is the metal atom M 1 The metal atom M may contain metals other than the metal atom M. 1 Examples of metals other than these include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), etc. These metals may be of one type or a plurality of types.

[0038] From the viewpoint of increasing the strain hardening property of the polar group-containing olefin copolymer, when the total number of metal atoms in the carboxylic acid metal salt group contained in the polar group-containing olefin copolymer is taken as 100 mol %, the metal atom M 1 The molar content of the metal atom M is preferably 50 to 100 mol %, more preferably 70 to 100 mol %, and even more preferably 90 to 100 mol %. 1 The molar content of can also be 100 mol %.

[0039] The structural unit (C) is preferably represented by the following formula (1). -(CH2CR 1 T 1 )-...Equation (1) [In formula (1), R 1 represents a hydrogen atom; a halogen atom; a carboxy group; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one halogen atom; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one carboxy group; or a hydrocarbon group having 1 to 10 carbon atoms, T 1 is the metal atom M 1 a metal carboxylate base having the metal atom M 1 represents a hydrocarbon group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, a substituted amino group having 1 to 12 carbon atoms, or a substituted silyl group having 1 to 18 carbon atoms, each of which is substituted with at least one metal carboxylate salt group having the formula: The substituted amino group may be a mono-substituted amino group or a di-substituted amino group. In the case of a di-substituted amino group, each substituent is a hydrocarbon group having 1 to 12 carbon atoms, and preferably a hydrocarbon group having 1 to 6 carbon atoms. The substituted silyl group may be a mono-, di-, or tri-substituted silyl group. In the case of a di- or tri-substituted silyl group, each substituent is a hydrocarbon group having 1 to 18 carbon atoms, and preferably a hydrocarbon group having 1 to 6 carbon atoms.

[0040] R 1 Examples of the halogen atom in include fluorine, chlorine, and bromine, and may be chlorine. R 1The hydrocarbon group having 1 to 10 carbon atoms in the formula (I) may be a hydrocarbon group having a branch, a ring, and / or an unsaturated bond, or may be an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a 1-propyl group, a 1-butyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, a 1-nonyl group, a 1-decyl group, a t-butyl group, an i-propyl group, a 1,1-dimethylpropyl group, a 1,1,2-trimethylpropyl group, a 1,1-diethylpropyl group, an i-butyl group, a 1,1-dimethylbutyl group, a 2-pentyl group, a 3-pentyl group, a 2-hexyl group, a Examples of such groups include a 3-hexyl group, a 2-ethylhexyl group, a 2-heptyl group, a 3-heptyl group, a 4-heptyl group, a 2-propylheptyl group, a 2-octyl group, a 3-nonyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a methylcyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 1-adamantyl group, and a 2-adamantyl group. R 1 Examples of the hydrocarbon group having 1 to 10 carbon atoms substituted with at least one halogen atom in the above formula (I) include groups in which at least one hydrogen atom in the hydrocarbon group having 1 to 10 carbon atoms has been substituted with the above halogen atom. Specific examples include a trifluoromethyl group. R 1 Examples of the hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one carboxy group in the above formula include groups in which at least one hydrogen atom in the hydrocarbon group having 1 to 10 carbon atoms has been substituted with a carboxy group. Among them, R 1 is preferably a hydrogen atom or a methyl group.

[0041] T 1 The carboxylate metal salt group in the structural unit (B) is, for example, a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1In the copolymer of the raw material of the polar group-containing olefin copolymer, after hydrolyzing or thermally decomposing the ester group, or while hydrolyzing or thermally decomposing, neutralizing with a compound containing a metal atom M having a Pauling electronegativity χ of 1.83 or more 1 In this way, the ester group moiety in the raw copolymer can be converted to a metal carboxylate salt group. The metal atoms may be of one type or of multiple types.

[0042] T 1 The metal atom M in 1 a metal carboxylate base having the metal atom M 1 The hydrocarbon group having 1 to 30 carbon atoms, the alkoxycarbonyl group having 2 to 20 carbon atoms, the alkoxy group having 1 to 20 carbon atoms, the acyloxy group having 2 to 20 carbon atoms, the substituted amino group having 1 to 12 carbon atoms, or the substituted silyl group having 1 to 18 carbon atoms, which is substituted with at least one carboxylate metal salt group having the formula 2 The carboxyl group in the compound can be converted to a metal carboxylate salt by the above-mentioned procedure. Also, T 1 The metal atom M in 1 The metal carboxylate group having the formula (3) is -CO2(R 32 ) group into a metal carboxylate salt by the procedure described above. 1 The metal atom M in 1 The hydrocarbon group having 1 to 30 carbon atoms, the alkoxycarbonyl group having 2 to 20 carbon atoms, the alkoxy group having 1 to 20 carbon atoms, the acyloxy group having 2 to 20 carbon atoms, the substituted amino group having 1 to 12 carbon atoms, or the substituted silyl group having 1 to 18 carbon atoms, which is substituted with at least one carboxylic acid metal salt group having the formula 1is substituted with at least one alkoxycarbonyl group, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, a substituted amino group having 1 to 12 carbon atoms, or a substituted silyl group having 1 to 18 carbon atoms, and the ester group is converted to a carboxylate metal salt group by the above-mentioned operation. T 1 is the metal atom M 1 Preferably, the metal carboxylate salt has the formula:

[0043] The structural unit (C) may be a single unit or multiple units. The structural unit (C) may be a structural unit (B) modified by converting a carboxy group or a dicarboxylic anhydride group into a metal salt, or may not be a structural unit (B) modified.

[0044] (4) Other structural units The polar group-containing olefin copolymer may contain structural units other than the structural units (A) to (C). Examples of the other structural unit (D) include acyclic monomers and cyclic monomers. Examples of the acyclic monomer include the monomers disclosed in paragraphs 0026 to 0028 of JP-A-2023-143881. 1 ~T 4 Monomers containing an ester group having 2 to 20 carbon atoms are not included. Examples of cyclic monomers include the monomers disclosed in paragraphs 0030 to 0031 of JP-A No. 2023-143881.

[0045] (5) Unit quantity of each structural unit The amount of structural units in the polar group-containing olefin copolymer (structural unit amount) will be described. A structural unit (A) derived from at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and a structural unit (C) having a carboxylate metal salt group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 In the structural units (C) including the following, the smallest repeating structural unit is defined as one structural unit in the copolymer. The amount of structural units is the ratio of each structural unit expressed in mol % when the total structural units in the copolymer is taken as 100 mol %.

[0046] Structural unit amount of structural unit (A): The structural unit amount (molar content) of the structural unit (A) is preferably 80.00 to 99.99 mol%. The structural unit amount (molar content) of the structural unit (A) can also be 80.0 to 97.0 mol%. The lower limit of the structural unit amount of the structural unit (A) may be 80.00 mol% or more, 85.00 mol% or more, 90.00 mol% or more, 92.00 mol% or more, 94.00 mol% or more, or 95.00 mol% or more. The upper limit may be 99.99 mol% or less, 99.95 mol% or less, 99.90 mol% or less, 99.50 mol% or less, 99.00 mol% or less, 98.50 mol% or less, 98.00 mol% or less, 97.50 mol% or less, 97.00 mol% or less, 96.90 mol% or less, 96.50 mol% or less, 96.00 mol% or less, or 95.50 mol% or less. It is believed that when the structural unit amount of the structural unit (A) is 80.00 mol % or more, the copolymer tends to have sufficient mechanical properties, and when it is 99.99 mol % or less, the copolymer tends to have sufficient strain hardening properties.

[0047] Structural unit amount of structural unit (B) and structural unit (C): The sum of the structural unit amounts (molar content) of the structural units (B) and (C) is preferably 0.01 to 20.00 mol%. The sum of the structural unit amounts (molar content) of the structural units (B) and (C) can also be 3.0 to 20.0 mol%. The lower limit of the sum of the structural unit amounts of the structural units (B) and (C) may be 0.01 mol% or more, 0.05 mol% or more, 0.10 mol% or more, 0.50 mol% or more, 1.00 mol% or more, 1.50 mol% or more, 2.00 mol% or more, 2.50 mol% or more, 3.00 mol% or more, 3.10 mol% or more, 3.50 mol% or more, 4.00 mol% or more, or 4.50 mol% or more. The upper limit may be 20.00 mol% or less, 15.00 mol% or less, 10.00 mol% or less, 8.00 mol% or less, 6.00 mol% or less, or 5.00 mol% or less. It is believed that when the total amount of the structural units (B) and (C) is 0.01 mol% or more, sufficient strain hardening properties are easily obtained, and when it is 20.00 mol% or less, sufficient mechanical properties are easily obtained.

[0048] Structural unit (C) content (neutralization degree) mol%: The content of the structural unit (C) refers to the ratio of the molar content of the structural unit (C) to the sum of the molar contents of the structural unit (B) and the structural unit (C), also referred to as the degree of neutralization. When the sum of the contents of the structural unit (B) and the structural unit (C) is taken as 100 mol%, the lower limit of the degree of neutralization is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, and particularly preferably 15 mol% or more. The upper limit of the content of the structural unit (C) may be 100 mol%, but is preferably 99 mol% or less, more preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 65 mol% or less, and particularly preferably 55 mol% or less. The upper limit of the content of the structural unit (C) can also be 45 mol% or less.

[0049] When the degree of neutralization is high, the polar group-containing olefin copolymer tends to have a high strain hardening degree but a high shear viscosity, whereas when the degree of neutralization is low, the polar group-containing olefin copolymer tends to have a low shear viscosity and high fluidity but a low strain hardening degree. It is believed that when the degree of neutralization is 1 mol % or more, sufficient strain hardening properties are easily obtained, and when the degree of neutralization is 99 mol % or less, fluidity is maintained and sufficient moldability is easily obtained.

[0050] (6) 13 Number of methyl branches, ethyl branches, and butyl branches calculated by C-NMR The polar group-containing olefin copolymer is 13 The number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms. The number of methyl branches, the number of ethyl branches, and the number of butyl branches are factors that inhibit crystallization in the structure of the polar group-containing olefin copolymer, and the smaller the number of these branches, the better the mechanical properties of the copolymer.

[0051] Metal atom M with Pauling electronegativity χ of 1.83 or more 1 The structural unit (C) includes 13 A polar group-containing olefin copolymer having the numbers of methyl branches, ethyl branches, and butyl branches calculated by C-NMR within the above ranges has excellent mechanical strength and transparency, as well as high strain hardening properties and excellent moldability. The polar group-containing olefin copolymer is 13 It is preferred that the number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, and the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms.

[0052] In order to increase the elastic modulus and obtain sufficient mechanical properties in the polar group-containing olefin copolymer, 13 The number of methyl branches calculated by C-NMR is preferably 50 or less, more preferably 5.0 or less, even more preferably 4.0 or less, even more preferably 3.0 or less, and particularly preferably 2.5 or less per 1,000 carbon atoms. There is no particular lower limit for the number of methyl branches, and the lower the better.

[0053] In order to increase the elastic modulus and obtain sufficient mechanical properties in the polar group-containing olefin copolymer, 13 The sum of the number of ethyl branches and the number of butyl branches calculated by C-NMR is preferably less than 4.2 per 1,000 carbon atoms, more preferably 4.0 or less, more preferably 3.8 or less, more preferably 3.5 or less, more preferably 3.0 or less, more preferably 2.5 or less, even more preferably 2.0 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. There is no particular lower limit for the sum of the number of ethyl branches and the number of butyl branches, and the lower the better. 13 The sum of the number of ethyl branches and the number of butyl branches calculated by C-NMR can also be 10 or less, or 7.0 or less, per 1,000 carbon atoms. The upper limit of the number of ethyl branches may be less than 4.2 per 1,000 carbon atoms, or may be 4.0 or less, 3.5 or less, 3.0 or less, 2.0 or less, 1.0 or less, or 0.5 or less. The lower limit of the number of ethyl branches is not particularly limited, and the lower the better. The upper limit of the number of butyl branches may be less than 4.2 per 1,000 carbon atoms, or may be 4.0 or less, 3.0 or less, 2.0 or less, 1.0 or less, or 0.5 or less. The lower limit of the number of butyl branches is not particularly limited, and the lower the better. The upper limit of the number of butyl branches may also be 7.0 or less or 5.0 or less per 1,000 carbon atoms.

[0054] (7) Method for measuring the amount of each structural unit in a polar group-containing olefin copolymer, as well as the number of methyl branches, ethyl branches, and butyl branches The structural unit amount of each structural unit in the polar group-containing olefin copolymer, as well as the number of methyl branches, the number of ethyl branches, and the number of butyl branches are 13 It can be determined using C-NMR spectroscopy. 13 The details of the C-NMR measurement method and the measuring device are as described in Examples. The structural unit (B) may be determined from the ratio of the structural unit (C) measured by the IR spectrum described later, based on the value measured for the raw material copolymer by the method described in Examples.

[0055] obtained 13 In C-NMR, signals specific to each structural unit or the monomer or branch from which it is derived contained in the polar group-containing olefin copolymer are identified, and their intensities are compared to analyze the amount of each structural unit and the number of various branches in the polar group-containing olefin copolymer. The positions of the signals specific to each structural unit or the monomer or branch from which it is derived can be determined by reference to publicly known materials, or can be independently identified depending on the sample. Such analytical techniques are commonly known to those skilled in the art.

[0056] The sum of the structural unit amounts (molar content) of the structural units (B) and (C) was calculated as described in the Examples. In the Examples, starting from a raw material copolymer, ethylene / t-butyl acrylate copolymer, all structural units derived from t-butyl acrylate in the copolymer were modified to structural units (B) or (C) to produce a polar group-containing olefin copolymer. That is, the amount of structural units derived from t-butyl acrylate in the raw material copolymer is the sum of the structural unit amounts of structural units (B) and (C). The amount of structural units derived from t-butyl acrylate in the raw material copolymer was calculated from the signal intensity of the quaternary carbon signal of the t-butyl group. The amount of the structural unit (A) is determined by subtracting the amount of structural units derived from t-butyl acrylate in the raw copolymer from 100 mol %.

[0057] (8) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn): The weight-average molecular weight (Mw) of the polar group-containing olefin copolymer has a lower limit of usually 1,000 or more, and may be 6,000 or more, 10,000 or more, 15,000 or more, or 20,000 or more. The upper limit is usually 2,000,000 or less, and may be 1,500,000 or less, 1,000,000 or less, or 800,000 or less, and most preferably 100,000 or less. If the Mw is 1,000 or more, the polar group-containing olefin copolymer will have sufficient physical properties such as mechanical strength and impact resistance, and if the Mw is 2,000,000 or less, the melt viscosity of the copolymer will be appropriate, and it is thought that the molding process of the copolymer will be little affected.

[0058] The ratio (Mw / Mn) of Mw to number average molecular weight (Mn) of the polar group-containing olefin copolymer is usually 1.5 to 4.0, and may be 1.6 to 3.5, 1.7 to 3.7, or 1.9 to 2.4. If Mw / Mn is 1.5 or more, it is likely that sufficient processability, including molding, of the polar group-containing olefin copolymer will be easily obtained, and if it is 4.0 or less, it is likely that sufficient mechanical properties will be easily obtained.

[0059] The Mw and Mn are determined by gel permeation chromatography (GPC). The molecular weight distribution parameter (Mw / Mn) is determined by further determining Mn by GPC and calculating the ratio of Mw to Mn, Mw / Mn. Details of the GPC measurement method and measurement device are as described in the Examples.

[0060] (Calculation of molecular weight (M)) The standard polystyrene method was used, and the conversion from retention volume to molecular weight was performed using a calibration curve prepared in advance using standard polystyrene. Examples of standard polystyrenes used include those manufactured by Tosoh Corporation (F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000) and monodisperse polystyrenes manufactured by Showa Denko K.K. (S-7300, S-3900, S-1950, S-1460, S-1010, S-565, S-152, S-66.0, S-28.5, S-5.05, each in a 0.07 mg / mL solution). A calibration curve was prepared by injecting 0.2 mL of a solution of each of the polystyrenes dissolved in ODCB (containing 0.5 mg / mL BHT) at 0.5 mg / mL. The calibration curve is a cubic equation obtained by approximating using the least squares method, or a quartic equation obtained by approximating the logarithm of the elution time and molecular weight. The viscosity formula [η] = K × Mα used to convert to molecular weight (M) uses the following values. Polystyrene (PS): K = 1.38 x 10 -4 , α=0.7 Polyethylene (PE): K = 3.92 x 10 -4 , α=0.733 Polypropylene (PP): K = 1.03 x 10 -4 , α=0.78

[0061] (9) Molecular structure of polar group-containing olefin copolymer: The molecular chain terminal of the polar group-containing olefin copolymer may be a structural unit (A) derived from at least one monomer selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms; or a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic acid anhydride group; or the metal atom M 1 The structural unit (C) may be a structural unit having a metal carboxylate group containing the following.

[0062] The polar group-containing olefin copolymer includes a structural unit (A) derived from at least one monomer selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and the metal atom M 1 Examples of the copolymer include random copolymers, block copolymers, and graft copolymers of the structural unit (C) having a carboxylate metal salt group, including the following: Among these, a random copolymer that can contain a large amount of the structural unit (B) may be used.

[0063] An example of the molecular structure of a typical ternary copolymer (1) is shown below. The random copolymer is a copolymer of the following molecular structure example (1): structural unit (A) derived from at least one monomer selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms; structural unit (B) having at least one monomer selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and the metal atom M 1 and a structural unit (C) having a carboxylate metal salt group including the following, in which the probability of finding each structural unit at any position in a molecular chain is independent of the type of the adjacent structural unit.

[0064] As shown below, the molecular structure example (1) of the copolymer includes a structural unit (A) derived from at least one monomer selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms, a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group, and the metal atom M 1and a structural unit (C) having a metal carboxylate salt group containing the following compound form a random copolymer. [ka]

[0065] The polar group-containing olefin copolymer preferably has a linear molecular structure, and from that viewpoint, it is preferably produced in the presence of a transition metal catalyst. It is known that the molecular structure of the copolymer varies depending on the production method, such as polymerization by a high-pressure radical polymerization process or polymerization using a metal catalyst. This difference in molecular structure can be controlled by selecting the production method. The difference in molecular structure can be exemplified by the difference in the number of branches. It is known that in polymerization by a high-pressure radical polymerization process, even in ethylene homopolymerization, many ethyl branches and butyl branches are generated, and the number of branches increases further in copolymerization of ethylene with a comonomer having a polar group (Macromolecules, 1997, 30, pp. 246-256).

[0066] As another example of differences in molecular structure, the molecular structure can also be estimated from the complex modulus measured with a rotational rheometer, as described in JP 2010-150532 A. This complex modulus may be the value for the raw copolymer of the polar group-containing olefin copolymer. This is because, when the polar group-containing olefin copolymer is not directly produced by one-step polymerization, a step of converting the raw copolymer into the polar group-containing olefin copolymer is required, but this conversion step does not include a reaction that affects the molecular structure of the polymer. Examples of reactions included in the conversion step include reactions for converting the side chains of the polymer, such as deprotection of esters and neutralization reactions with metal salts, but do not involve dissociation and recombination of carbon-carbon bonds in the main chain.

[0067] · Absolute value of complex elastic modulus G * Phase angle δ at =0.1MPa: In the present invention, the absolute value G of the complex modulus of the raw material copolymer of the polar group-containing olefin copolymer measured with a rotational rheometer * The phase angle δ at σ = 0.1 MPa may have a lower limit of 50 degrees or more, 51 degrees or more, 54 degrees or more, 56 degrees or more, or 58 degrees or more, and an upper limit of 75 degrees or less, or 70 degrees or less. More specifically, the phase angle δ(G * = 0.1 MPa) is 50 degrees or higher, the molecular structure of the copolymer is a linear structure that does not contain any long chain branches or a structure that contains a small amount of long chain branches that does not affect the mechanical strength.

[0068] The phase angle δ is affected by both the molecular weight distribution and the long chain branching. However, it is an index of the amount of long chain branching only for copolymers with Mw / Mn≦4.0, more preferably Mw / Mn≦3.0. The more long chain branches there are in the molecular structure, the lower the δ(G * = 0.1 MPa) value is small. If the Mw / Mn of the copolymer is 1.5 or more, the phase angle δ(G * =0.1MPa) never exceeds 75 degrees. Details of the method and device for measuring the complex elastic modulus for determining the phase angle δ are as described in the Examples.

[0069] 2. Method for producing polar group-containing olefin copolymer The polar group-containing olefin copolymer preferably has a linear molecular structure, and 13 The number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms. From this viewpoint, it is preferably produced in the presence of a transition metal catalyst.

[0070] (1) Polymerization catalyst The type of polymerization catalyst used in the production of the polar group-containing olefin copolymer is not particularly limited as long as it is capable of copolymerizing the monomers from which the structural unit (A), the structural unit (B), and the structural unit (C) are derived. Examples of the catalyst include transition metal compounds of Groups 5 to 11 having a chelating ligand. Specific examples of preferred transition metals include vanadium atom, niobium atom, tantalum atom, chromium atom, molybdenum atom, tungsten atom, manganese atom, iron atom, platinum atom, ruthenium atom, cobalt atom, rhodium atom, nickel atom, palladium atom, copper atom, etc. Among these, transition metals of Groups 8 to 11 are preferred, transition metals of Group 10 are more preferred, and nickel atom or palladium atom is particularly preferred. These transition metals may be used alone or in combination.

[0071] Chelating ligands have at least two atoms selected from the group consisting of phosphorus (P), nitrogen (N), oxygen (O), and sulfur (S), and include bidentate or multidentate ligands, and are electronically neutral or anionic. Examples of chelating ligand structures are provided in a review by Brookhart et al. (Chem. Rev., 2000, 100, 1169).

[0072] The chelating ligand preferably includes a bidentate anionic P,O ligand. Examples of the bidentate anionic P,O ligand include phosphorus sulfonic acid, phosphorus carboxylic acid, phosphorus phenol, and phosphorus enolate. Other examples of the chelating ligand include a bidentate anionic N,O ligand. Examples of the bidentate anionic N,O ligand include salicylaldiminate and pyridinecarboxylic acid. Other examples of the chelating ligand include a diimine ligand, a diphenoxide ligand, and a diamide ligand.

[0073] The structure of the metal complex obtained from the chelating ligand is represented by the following structural formula (a) or (b), in which an arylphosphine compound, an arylarsine compound, or an arylantimony compound, which may have a substituent, is coordinated. [ka] [ka] [In structural formula (a) and structural formula (b), M represents a transition metal atom belonging to any of Groups 5 to 11 of the periodic table of elements, that is, various transition metal atoms as described above. X 1 represents oxygen, sulfur, -SO3-, or -CO2-. Y 1 represents carbon or silicon. n represents an integer of 0 or 1. E 1 represents phosphorus, arsenic or antimony. R 53 and R 54 each independently represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R 55 each independently represents hydrogen, halogen, or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R 56 and R 57 are each independently hydrogen, halogen, a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom, OR 52 , CO2R 52 , CO2M', C(O)N(R 51 )2, C(O)R 52 , S.R. 52 , SO2R 52 , SOR 52 , OSO2R 52 , P(O)(OR 52 ) 2-y (R 51 ) y , CN, NHR 52 , N(R 52)2, Si(OR 51 ) 3-x (R 51 ) x , OSi(OR 51 ) 3-x (R 51 ) x , NO2, SO3M', PO3M'2, P(O)(OR 52 )2M' or an epoxy-containing group. R 51 represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms. R 52 represents a hydrocarbon group having 1 to 20 carbon atoms. M' represents an alkali metal, an alkaline earth metal, ammonium, a quaternary ammonium, or a phosphonium; x represents an integer of 0 to 3; and y represents an integer of 0 to 2. In addition, R 56 and R 57 may be linked to each other to form an alicyclic ring, an aromatic ring, or a heterocyclic ring containing a heteroatom selected from oxygen, nitrogen, and sulfur, in which case the ring has 5 to 8 members and may or may not have a substituent on the ring. L 1 represents a ligand coordinated to M. Also, R 53 and L 1 may be bonded to each other to form a ring.

[0074] More preferably, it is a transition metal complex represented by the following structural formula (c). [ka] [In structural formula (c), M represents a transition metal belonging to any of Groups 5 to 11 of the periodic table of elements, that is, various transition metal atoms as described above. X 1 represents oxygen, sulfur, -SO3-, or -CO2-. Y 1 represents carbon or silicon. n represents an integer of 0 or 1. E 1represents phosphorus, arsenic or antimony. R 53 and R 54 each independently represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R 55 each independently represents hydrogen, halogen, or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom. R 58 , R 59 , R 60 and R 61 are each independently hydrogen, halogen, a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom, OR 52 , CO2R 52 , CO2M', C(O)N(R 51 )2, C(O)R 52 , S.R. 52 , SO2R 52 , SOR 52 , OSO2R 52 , P(O)(OR 52 ) 2-y (R 51 ) y , CN, NHR 52 , N(R 52 )2, Si(OR 51 ) 3-x (R 51 ) x , OSi(OR 51 ) 3-x (R 51 ) x , NO2, SO3M', PO3M'2, P(O)(OR 52 )2M' or an epoxy-containing group. R 51 represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms. R 52 represents a hydrocarbon group having 1 to 20 carbon atoms. M' represents an alkali metal, an alkaline earth metal, ammonium, a quaternary ammonium, or a phosphonium; x represents an integer of 0 to 3; and y represents an integer of 0 to 2. In addition, R 58 ~R 61A plurality of groups appropriately selected from the group consisting of may be linked together to form an alicyclic ring, an aromatic ring, or a heterocyclic ring containing a heteroatom selected from oxygen, nitrogen, or sulfur, in which case the ring has 5 to 8 members and may or may not have a substituent on the ring. L 1 represents a ligand coordinated to M. Also, R 53 and L 1 may be bonded to each other to form a ring.

[0075] Here, typical catalysts of transition metal compounds of Groups 5 to 11 having a chelating ligand include so-called SHOP-based catalysts and Drent-based catalysts. The SHOP catalyst is a catalyst in which a phosphorus-based ligand having an aryl group which may have a substituent is coordinated to nickel metal (see, for example, WO2010 / 050256). Furthermore, Drent-based catalysts are catalysts in which a phosphorus-based ligand having an aryl group which may have a substituent is coordinated to palladium metal (see, for example, JP-A-2010-202647).

[0076] (2) Copolymerization method: The polymerization method for producing the polar group-containing olefin copolymer is not limited. Examples of the polymerization method include slurry polymerization in which at least a portion of the produced polymer becomes a slurry in a medium, bulk polymerization in which liquefied monomer itself is used as a medium, gas phase polymerization carried out in vaporized monomer, and high pressure ionic polymerization in which at least a portion of the produced polymer is dissolved in monomer liquefied at high temperature and high pressure. The polymerization method may be any of batch polymerization, semi-batch polymerization, and continuous polymerization.

[0077] Furthermore, living polymerization may be carried out, or polymerization may be carried out while chain transfer occurs simultaneously. Furthermore, during polymerization, a so-called chain shuttling agent (CSA) may be used in combination to carry out a chain shuttling reaction or coordinated chain transfer polymerization (CCTP). Specific manufacturing processes and conditions are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2010-260913 and 2010-202647.

[0078] (3) Method for introducing a carboxyl group or a dicarboxylic anhydride group The structural unit (B) in the polar group-containing olefin copolymer may be obtained directly by copolymerizing a monomer having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group, or may be copolymerized with another monomer and then modified to introduce at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group into the structure. The introduction method is not particularly limited and may be selected from various methods within the scope of the present invention.

[0079] Examples of the method for introducing at least one group selected from the group consisting of a carboxy group and a dicarboxylic anhydride group by modification include, for example, a method for introducing a carboxy group by copolymerizing an acrylic acid ester and then hydrolyzing the copolymer to convert it into a carboxy group, and a method for copolymerizing an acrylic acid ester and then thermally decomposing the copolymer to convert it into a carboxy group.

[0080] A conventionally known acid-base catalyst may be used as an additive to promote the hydrolysis or thermal decomposition reaction. The acid-base catalyst is not particularly limited, and examples thereof include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal or alkaline earth metal carbonates such as sodium bicarbonate and sodium carbonate; solid acids such as montmorillonite; inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; and organic acids such as formic acid, acetic acid, benzoic acid, citric acid, paratoluenesulfonic acid, trifluoroacetic acid, and trifluoromethanesulfonic acid. From the viewpoint of reaction accelerating effect, cost, corrosion resistance of equipment, etc., sodium hydroxide, potassium hydroxide, sodium carbonate, paratoluenesulfonic acid, or trifluoroacetic acid is preferred, and paratoluenesulfonic acid or trifluoroacetic acid is more preferred.

[0081] (4) Introduction of a metal carboxylate base The polar group-containing olefin copolymer is a copolymer containing the structural unit (A) and the structural unit (B) obtained by the above-mentioned method for introducing a carboxy group or a dicarboxylic anhydride group, which is then mixed with a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 The polar group-containing olefin copolymer may be obtained by treating a copolymer having the structural unit (A) and a structural unit derived from an unsaturated carboxylic acid ester with a compound containing the structural unit (A) to convert the carboxy group or the dicarboxylic acid anhydride group into a metal carboxylate salt. The polar group-containing olefin copolymer may be obtained by heating a copolymer having the structural unit (A) and a structural unit derived from an unsaturated carboxylic acid ester to convert at least a part of the ester groups in the copolymer into carboxy groups, or by converting a metal atom M having a Pauling electronegativity χ of 1.83 or more directly from the ester groups. 1 Alternatively, the compound may be obtained by a heat conversion step in which the compound is converted into a metal carboxylate salt containing

[0082] When a polar group-containing olefin copolymer is produced after introducing a carboxy group and / or a dicarboxylic anhydride group into a polymer, the production method is, for example, as follows: That is, a metal atom source is prepared by kneading, optionally with heating, a metal salt with a substance that captures metal atoms (ions), such as an ethylene / (meth)acrylic acid ((M)AA) copolymer, and then adding the metal atom source to a copolymer that is the raw material for the polar group-containing olefin copolymer in an amount that achieves the desired degree of neutralization, followed by kneading.

[0083] In the thermal conversion step, (i) a copolymer of ethylene and at least one selected from the group consisting of α-olefins having 3 to 20 carbon atoms and an unsaturated carboxylic acid ester is heated to form a copolymer of ethylene and at least one selected from the group consisting of α-olefins having 3 to 20 carbon atoms and an unsaturated carboxylic acid by hydrolysis or thermal decomposition, and then a metal atom M having a Pauling electronegativity χ of 1.83 or more is added to the copolymer. 1 (ii) a copolymer of at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms and an unsaturated carboxylic acid ester is heated to hydrolyze or thermodecompose the ester groups of the copolymer, while reacting the copolymer with a compound containing a metal atom M having a Pauling electronegativity χ of 1.83 or more. 1 The ester group moiety in the copolymer may be converted to a metal carboxylate salt group by reacting the copolymer with a compound containing the following:

[0084] metal atom M 1 The compound containing the formula (I) may be an oxide, hydroxide, carbonate, bicarbonate, acetate, formate, or the like of a metal having a Pauling electronegativity χ of 1.83 or more. metal atom M 1 The compound containing may be supplied to the reaction system in the form of particles or fine powder, or may be dissolved or dispersed in water or an organic solvent and then supplied to the reaction system. Alternatively, a masterbatch may be prepared using, for example, a copolymer of ethylene and an unsaturated carboxylic acid or an olefin copolymer as a base polymer and then supplied to the reaction system. In order to ensure smooth reaction, it is preferable to prepare a masterbatch and supply it to the reaction system.

[0085] Furthermore, the metal atom M 1 The reaction with the compound containing (I) may be carried out by melt-kneading using various types of equipment such as a vent extruder, a Banbury mixer, or a roll mill, and the reaction may be carried out batchwise or continuously. Since the reaction can be carried out smoothly by discharging water and carbon dioxide gas by-produced in the reaction using a degasser, it is preferable to carry out the reaction continuously using an extruder equipped with a degasser such as a vent extruder. metal atom M 1 In the reaction with a compound containing the formula (I), a small amount of water may be added to promote the reaction.

[0086] The temperature at which the copolymer of ethylene and at least one selected from the group consisting of α-olefins having 3 to 20 carbon atoms and an unsaturated carboxylic acid ester is heated may be any temperature at which the ester groups are converted to carboxy groups. If the heating temperature is too low, the ester groups will not be converted to carboxy groups, and if the heating temperature is too high, decarbonylation and decomposition of the copolymer will proceed. Therefore, the heating temperature may be in the range of 80°C to 350°C, 100°C to 340°C, 150°C to 330°C, or 200°C to 320°C.

[0087] The reaction time varies depending on the heating temperature, the reactivity of the ester group portion, etc., but is usually 1 minute to 50 hours, may be 2 minutes to 30 hours, may be 2 minutes to 10 hours, may be 2 minutes to 3 hours, or may be 3 minutes to 2 hours.

[0088] The reaction atmosphere in the above steps is not particularly limited, but may be carried out under a stream of inert gas. Examples of inert gases that can be used include nitrogen, argon, and carbon dioxide. A small amount of oxygen or air may be present.

[0089] The reactor used in the above step is not particularly limited as long as it can stir the copolymer substantially uniformly. A glass vessel or autoclave (AC) equipped with a stirrer may be used, or any conventionally known kneader may be used, such as a Brabender Plastograph, a single-screw or twin-screw extruder, a high-intensity screw kneader, a Banbury mixer, a kneader, or a roll.

[0090] Metal atom M 1Whether or not a polar group-containing olefin copolymer has been obtained can be confirmed by measuring the IR spectrum of the copolymer before and after the reaction and examining the decrease in the peak due to the carbonyl group of the carboxylic acid (dimer). The degree of neutralization can also be confirmed by calculating from the molar ratio described above, as well as examining the decrease in the peak due to the carbonyl group of the carboxylic acid (dimer) and the increase in the peak due to the carbonyl group of the carboxylic acid metal salt.

[0091] (5) Strain hardening Strain hardening is a property of a material whereby viscosity increases rapidly when it is stretched. This property prevents localized thinning during molding processes where free surfaces exist, such as blow molding and film molding, and produces effects such as uniform wall thickness in molded products; the stronger the strain hardening property, the better the moldability of the material. Regarding the method for measuring strain hardening, any method will in principle yield the same value as long as it can measure the uniaxial extensional viscosity. Details of the measurement method and measuring equipment are described, for example, in Non-Patent Documents 4 and 5. In the present invention, the strain hardening property can be evaluated by the strain hardening degree described in the examples, and the higher this value, the better the moldability. The strain hardening degree may be 2.4 or more, 2.5 or more, or 3.0 or more. There is no particular upper limit for the strain hardening degree, and the higher the better.

[0092] 3. Olefin-based resin composition and molded article containing the same The polar group-containing olefin copolymer has high strain hardening properties and excellent moldability, and the resulting molded articles have good properties such as mechanical strength and transparency. The polar group-containing olefin copolymer can be suitably used as a raw material for various molded articles. One aspect of the present invention is an olefin-based resin composition containing a polar group-containing olefin copolymer. The olefin-based resin composition is not particularly limited as long as it contains the polar group-containing olefin copolymer, and may contain other components, such as resins other than the polar group-containing olefin copolymer, and conventionally known additives such as antioxidants, ultraviolet absorbers, lubricants, antistatic agents, colorants, pigments, crosslinking agents, foaming agents, nucleating agents, flame retardants, conductive materials, and fillers, within the scope of the present invention.

[0093] As the resin other than the polar group-containing olefin copolymer, other olefin-based polymers are preferably used. Examples of other olefin polymers include low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene propylene rubber, ethylene propylene diene rubber, and polybutene. Furthermore, the resin composition of the present disclosure can use various resins other than the above-mentioned olefin-based polymers, specifically, various polyamides, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), various polyesters, polycarbonate resin, EVOH, EVA, PMMA, PMA, various engineering plastics, biodegradable resins such as polylactic acid, celluloses, natural rubbers, polyurethane, polystyrene, polyvinyl chloride, fluorine-based resins such as Teflon (registered trademark), inorganic polymers such as silicone resin, etc.

[0094] Another aspect of the present invention is a molded article containing an olefin-based resin composition. Examples of molding methods include blow molding, injection molding, extrusion molding, film molding, and foam molding. Polar group-containing olefin copolymers and olefin-based resin compositions containing the same have high strain hardening properties, and are therefore suitable for use in molding processes that have a free surface, such as blow molding and film molding. When forming a film, even if thickness unevenness occurs during the molding process, polar group-containing olefin copolymers and compositions containing them have high viscosity in the thinned areas, preventing film breakage and stabilizing the process. Furthermore, the copolymers and compositions containing them can prevent localized thinning during molding and achieve uniform thickness in molded products, thereby stabilizing processes in blow molding and foam molding, just as in film molding. Furthermore, the copolymers and compositions containing them can prevent flash formation during injection molding. In injection molding, the resin undergoes elongational flow when it infiltrates the gap between the molds from a wide cavity. The copolymers and compositions containing them increase their viscosity when stretched, making them less susceptible to stretching and suppressing flash formation. [Example]

[0095] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Measurements and evaluations of physical properties in the examples and comparative examples were carried out by the methods shown below.

[0096] <Measurement and evaluation of physical properties> (1) Absolute value of complex elastic modulus G * = 0.1MPa at the phase angle δ(G * =0.1MPa) 1) Sample preparation and measurement A 1g sample was placed in a 1.0mm thick heat press mold and preheated for 5 minutes in a heat press at a surface temperature of 180°C. Residual gas in the molten resin was removed by repeatedly applying pressure and depressurizing the pressure. The mold was then pressurized to 4.9MPa and held for 5 minutes. The sample was then transferred to a press at a surface temperature of 25°C and cooled by holding the press at 4.9MPa for 3 minutes to produce a pressed plate made of the sample with a thickness of approximately 1.0mm. The pressed plate was cut into a 25mm diameter circle and used as a sample. Dynamic viscoelasticity was measured using a Rheometrics ARES rotational rheometer under a nitrogen atmosphere under the following conditions: Plate: φ25mm (diameter) parallel plate ·Temperature: 160℃ Distortion: 10% Measurement angular frequency range: 1.0 x 10 -2 ~1.0×10 2 rad / s Measurement interval: 5 points / decade Absolute value of complex modulus G * Common logarithm logG of (Pa) * Plot the phase angle δ against logG * = 5.0, the value of δ (degrees) at the point corresponding to the phase angle δ (G * = 0.1 MPa). * If there is no point corresponding to =5.0, logG * Using two points around =5.0, logG * The δ value at logG = 5.0 was calculated by linear interpolation. * <5, logG * Using the three largest values, logG is calculated using a quadratic curve. * The δ value at δ = 5.0 was extrapolated.

[0097] (2) Measurement of Mw and Mw / Mn Mw was determined by gel permeation chromatography (GPC). Mw / Mn was calculated by determining Mn by GPC and then calculating the ratio of Mw to Mn, Mw / Mn. The measurements were carried out according to the following procedures and conditions.

[0098] 1) Preparation of sample solution 3 mg of sample and 3 mL of ODCB were weighed into a 4 mL vial, and the vial was sealed with a screw cap and a Teflon (registered trademark) septum, and then shaken for 2 hours at 150°C using a high-temperature shaker, SSC-7300, manufactured by Senshu Scientific Co., Ltd. After shaking, it was visually confirmed that there were no insoluble components.

[0099] 2) Measurement One Showdex HT-G and two Showdex HT-806M high-temperature GPC columns were connected to a Waters Alliance GPCV2000. Measurements were performed using ODCB as the eluent at a temperature of 145°C and a flow rate of 1.0 mL / min.

[0100] 3) Calibration curve The column was calibrated using monodisperse polystyrene (S-7300, S-3900, S-1950, S-1460, S-1010, S-565, S-152, S-66.0, S-28.5, S-5.05, each 0.07 mg / mL solution) manufactured by Showa Denko K.K., n-eicosane, and n-tetracontane under the same conditions as above, and the logarithm of the elution time and molecular weight was approximated by a quartic equation. PS ) and polyethylene molecular weight (M PE ) was converted using the following formula: M PE =0.468×M PS

[0101] (3) Melt flow rate (MFR) The MFR was measured in accordance with Table 1-Condition 7 of JIS K-7210 (1999) at a temperature of 190°C and a load of 21.18N (=2.16kg).

[0102] (4) Method for measuring the amount of structural unit (B) and the number of branches per 1,000 carbon atoms The structural unit amount of the structural unit (B) and the number of branches per 1,000 carbon atoms are 13 The carbon monoxide content was determined using C-NMR spectroscopy. 13 C-NMR was measured by the following method. 200 to 300 mg of sample was placed in an NMR sample tube with an inner diameter of 10 mm, together with 2.4 mL of a mixed solvent of ODCB and deuterated bromide benzene (CDBr) (ODCB / CDBr = 2 / 1 (volume ratio)) and hexamethyldisiloxane, a chemical shift reference substance. The tube was purged with nitrogen, sealed, and heated to dissolve the sample into a homogeneous solution, which was used as the NMR measurement sample. NMR measurements were carried out at 120°C using a Bruker AV400M NMR instrument equipped with a 10 mm diameter cryoprobe. 13 C-NMR was measured using the inverse gate decoupling method at a sample temperature of 120°C, a pulse angle of 90°, a pulse interval of 51.5 seconds, and an accumulation count of 512 or more. The chemical shifts are those of hexamethyldisiloxane. 13 The C signal was set to 1.98 ppm, and the other 13 The chemical shift of the C signal was based on this.

[0103] 1) Calculation of the structural unit amount of structural unit (B) <Ethylene (E) / t-butyl acrylate (tBA)> The quaternary carbon signal of the t-butyl acrylate group of tBA is 13 The chemical shifts in the C-NMR spectrum were detected in the range of 79.6 to 78.8. Using these signal intensities, the amount of comonomer in tBA was calculated using the following formula: Total amount of tBA (mol%) = I(tBA) × 100 / [I(tBA) + I(E)] Here, I(tBA) and I(E) are the quantities shown in the following formulas. I(tBA)=I 79.6~78.8 I(E)=(I 180.0~135.0 +I 120.0~5.0 -I(tBA)×7) / 2

[0104] 2) Calculation of the number of branches per 1,000 carbon atoms The number of branches per 1,000 carbon atoms was calculated by substituting any of the following I(B1), I(B2), or I(B4) for I(branch) in the following formula (5). B1 represents a methyl branch, B2 represents an ethyl branch, and B4 represents a butyl branch. The number of methyl branches was calculated using I(B1), the number of ethyl branches using I(B2), and the number of butyl branches using I(B4). Number of branches (per 1,000 carbon atoms) = I(branch) × 1000 / I(total) (5) Here, I(total), I(B1), I(B2) and I(B4) are quantities expressed by the following formulas. I(total)=I 180.0~135.0 +I 120.0~5.0 I(B1)=(I 20.0~19.8 +I 33.2~33.1 +I 37.5~37.3 ) / 4 I(B2)=I 8.6~7.6 +I 11.8~10.5 I(B4)=I 14.3~13.7 -I 32.2~32.0 where I is the integrated intensity, and the subscripts of I indicate the range of chemical shifts. For example, I 180.0~135.0 was detected between 180.0 ppm and 135.0 ppm. 13 The integrated intensity of the C signal is shown. The attribution was made with reference to the non-patent literature Macromolecules 1984, 17, 1756-1761 and Macromolecules 1979, 12, 41. When the branch number is indicated as "<0.1" including an inequality sign, it means that it is present as a structural unit in the copolymer, but the amount is less than 0.1 mol% taking into account significant figures. Also, "nd" means below the detection limit.

[0105] (5) Infrared absorption spectrum (IR spectrum) 0.1 g of the sample was melted at 180°C for 3 minutes and compression molded to prepare a film with a thickness of about 50 µm. This film was analyzed by Fourier transform infrared spectroscopy to obtain an infrared absorption spectrum. Product name: FT / IR-6100 manufactured by JASCO Corporation Measurement method: transmission method Detector: TGS (Triglycine sulfate) Accumulation count: 16 to 512 times Resolution: 4.0cm -1 Measurement wavelength: 5000~500cm -1

[0106] (6) Evaluation method for strain hardening The strain hardening property was evaluated by the strain hardening rate (λmax). Regarding the method for measuring the strain hardening rate, any method can in principle obtain the same value as long as it can measure the uniaxial extensional viscosity, and details of the measurement method and measuring device are described in, for example, Non-Patent Documents 4 and 5. In the present invention, the following measurement method and measuring device were used. (Measurement method) Equipment: TA Instruments ARES G2 Jig: TA Instruments extensional viscosity measurement jig Measurement temperature: 140℃ Strain rate: 0.2 [unit: 1 / sec] Preparation of test specimens: Strip-shaped sheets measuring 18 mm x 10 mm x 0.7 mm were prepared by melt pressing. (How to calculate λmax) The extensional viscosity measured under the above conditions is shown on the horizontal axis with time t (seconds) and on the vertical axis with extensional viscosity η E First, the η (MPa·sec) was plotted on the log-log plot just before the extensional viscosity suddenly increased (strain hardening). E The relationship between strain hardening and time was approximated linearly. E The maximum value of (η max ) was obtained. Also, η E The viscosity on the approximate straight line at the time when is maximized is η lin λmax is η max and η lin The ratio (η max / η lin ) defined as

[0107] <Synthesis of metal complexes> (Synthesis Example 1) Synthesis of B-423 / Ni complex The following 2-bis(2,6-dimethoxyphenyl)phosphano-6-(2,6-diisopropylphenyl)phenol ligand (B-423) was synthesized according to Synthesis Example 1 described in JP 2019-156764 A. A nickel complex (B-423 / Ni complex) was synthesized in which B-423 and Ni(cod) reacted in a 1:1 ratio using Ni(cod) in accordance with Example 1 of JP 2019-156764 A. [ka]

[0108] <Production Example 1-1: Production of copolymer (P1-1) as raw material for polar group-containing olefin copolymer> An ethylene / t-butyl acrylate copolymer was produced using the nickel complex (B-423 / Ni complex) prepared in Synthesis Example 1 above as the metal catalyst component. Copolymer (P1-1) was produced with reference to Production Example 1 described in JP 2016-79408 A. The resulting copolymer (P1-1) had an Mw of 27,000 and an Mw / Mn ratio of 2.2. Table 1 shows the production conditions used in the polymerization, including the type and amount of metal complex, the amount of aluminum compound (trioctylaluminum (TnOA)), the amount of toluene, the type of comonomer, the comonomer concentration, the ethylene partial pressure, the polymerization temperature, and the polymerization time.

[0109] [Table 1]

[0110] <Production Example 2-1: Production of copolymer (P2-1) as raw material for polar group-containing olefin copolymer> A 500 mL separable flask was charged with 40 g of the copolymer (P1-1) obtained in Production Example 1-1 above, 0.8 g of paratoluenesulfonic acid monohydrate, and 185 mL of toluene, and the mixture was stirred at 105°C for 4 hours. 185 mL of ion-exchanged water was added, stirred, and allowed to stand. The organic and aqueous layers were then separated, and the aqueous layer was removed. The ion-exchanged water was added to the resulting organic layer, and the aqueous layer was removed. This procedure was repeated until the pH of the removed aqueous layer reached 5 or higher, washing the organic layer. After washing, the solvent was removed from the organic layer by distillation under reduced pressure, and the mixture was dried to a constant weight, yielding copolymer (P2-1). In the IR spectrum of the obtained copolymer (P2-1), the 850 cm -1 The disappearance of the peak around 1730 cm originating from the carbonyl group of the ester -1 The decrease in the peak around 1700 cm originates from the carbonyl group of the carboxylic acid (dimer).-1 An increase in the peak around This confirmed the decomposition of t-butyl ester and the production of carboxylic acid. The content of structural unit (A) in copolymer (P2-1) was 96.9 mol %, the content of structural unit (B) was 3.1 mol %, and the phase angle δ was 60 degrees. The physical properties of the copolymer (P2-1) are shown in Table 2.

[0111] [Table 2]

[0112] <Examples 1 to 13 and Comparative Examples 1 to 7: Production of Polar Group-Containing Olefin Copolymers> 1) Preparation of Li supply source Lithium acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 30 ml of distilled water in an amount necessary for the desired degree of neutralization (for a degree of neutralization of 10%, lithium acetate corresponding to a degree of neutralization of 10% (0.011 mol × 0.1 = 0.0011 mol) relative to the molar content (0.011 mol) of structural unit (B) in 10 g of copolymer (P2-1)) and dissolved to prepare an aqueous lithium acetate solution, thereby producing a Li supply source.

[0113] 2) Preparation of Zn source As in 1) above, zinc acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 30 ml of distilled water in an amount required for the desired degree of neutralization, and dissolved to prepare an aqueous solution, thereby preparing a Zn source.

[0114] 3) Preparation of Ag source As in 1) above, silver acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 30 ml of distilled water in an amount required for the desired degree of neutralization, and dissolved to prepare an aqueous solution, thereby preparing an Ag supply source.

[0115] 4) Preparation of Fe source As in 1) above, iron acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 30 ml of distilled water in an amount necessary for the desired degree of neutralization and dissolved to prepare an aqueous solution, thereby preparing an Fe supply source.

[0116] 5) Preparation of Pb source As in 1) above, lead acetate hydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 30 ml of distilled water in an amount required for the desired degree of neutralization, and dissolved to prepare an aqueous solution, thereby preparing a Pb source.

[0117] 6) Preparation of polar group-containing olefin copolymers (ionomers) 10 g of the copolymer (P2-1) was placed in a small kneader, Xplore MC15, manufactured by DSM, and kneaded at 160°C and 100 rpm for 3 minutes to create a melt. Thereafter, the Li source, Zn source, Ag source, Fe source, or Pb source prepared in 1) to 5) above was added, and kneading was continued for 20 minutes at 250°C and 100 rpm. The resin obtained above was subjected to IR measurement. In the IR spectrum, a peak at 1700 cm originating from the carbonyl group of the carboxylic acid (dimer) was observed. -1 The peak around 1560 cm originating from the carbonyl group of the carboxylate metal base is reduced. -1 The peak at around 1700 cm originating from the carbonyl group of the carboxylic acid (dimer) was increased. This confirmed that the structural unit (C) was formed. -1 From the decrease in the peak in the vicinity, it was confirmed that a polar group-containing olefin copolymer with the desired degree of neutralization had been produced. Table 3 shows the degree of neutralization, extensional viscosity and strain hardening property of each polar group-containing olefin copolymer.

[0118] [Table 3]

[0119] <Discussion of the results of Examples and Comparative Examples> Table 3 shows the strain hardening (λmax) values ​​of the obtained polar group-containing olefin copolymers. In Examples 1 to 6, Ag (1.93), which has a Pauling electronegativity χ of 1.83 or more, was used to vary the degree of neutralization. In Examples 7 to 9, Fe (Pauling electronegativity χ of 1.83) was used to vary the degree of neutralization. In Examples 10 to 13, Pb (Pauling electronegativity χ of 2.33) was used to vary the degree of neutralization. In Comparative Examples 1 to 7, Li (0.98) and Zn (1.65), which have electronegativity χ lower than 1.83, were used to vary the degree of neutralization. It can be seen that the λmax of the Examples is significantly higher than that of the Comparative Examples when compared at the same degree of neutralization. Furthermore, even in Examples 1, 7, and 10, which had a low degree of neutralization of 10%, a sufficiently high λmax was shown. Furthermore, at the same η lin Comparisons between the Examples and Comparative Examples in the above also reveal that the λmax of the Examples is significantly higher (for example, comparisons between Examples 1, 12, and 13 and Comparative Example 2; comparisons between Example 5 and Comparative Example 7; and comparisons between Example 7 and Comparative Example 6). This indicates that polar group-containing olefin copolymers having a carboxylic acid metal salt group using metal atoms with Pauling's electronegativity χ of 1.83 or more have a significantly better balance between fluidity and strain hardening than polar group-containing olefin copolymers having a carboxylic acid metal salt group using metal atoms with χ of less than 1.83. [Industrial Applicability]

[0120] The polar group-containing olefin copolymer of the present invention is useful because it has a better balance of fluidity and strain hardening properties than conventional polar group-containing olefin copolymers. Furthermore, the main chain of the polar group-containing olefin copolymer has a substantially linear structure with an extremely small number of short chain branches, and also has good impact resistance and adhesiveness, making it useful.

Claims

1. A structural unit (A) derived from at least one selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms; a structural unit (B) having at least one selected from the group consisting of a carboxy group and a dicarboxylic anhydride group; and a structural unit (C) having a carboxylate metal salt group, wherein the metal is a metal atom M having a Pauling electronegativity χ of 1.83 or more. １ and a structural unit (C) comprising: １３ A polar group-containing olefin copolymer, in which the number of methyl branches calculated by C-NMR is 50 or less per 1,000 carbon atoms, or the sum of the number of ethyl branches and the number of butyl branches is less than 4.2 per 1,000 carbon atoms.

2. The polar group-containing olefin copolymer according to claim 1 , wherein the structural unit (C) is represented by the following formula (1): -(CH ２ CR １ T １ )- ・・・Formula (1) [In formula (1), R １ represents a hydrogen atom; a halogen atom; a carboxy group; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one halogen atom; a hydrocarbon group having 1 to 10 carbon atoms and substituted with at least one carboxy group; or a hydrocarbon group having 1 to 10 carbon atoms, T １ is the metal atom M １ or the metal atom M １ and represents a hydrocarbon group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, a substituted amino group having 1 to 12 carbon atoms, or a substituted silyl group having 1 to 18 carbon atoms, each of which is substituted with at least one metal carboxylate salt group having the formula:

3. 2. The polar group-containing olefin copolymer according to claim 1, wherein the χ is 1.83 to 2.

36.

4. The metal atom M １ is at least one selected from the group consisting of Fe, Co, Cu, Ni, Ge, Tc, Mo, Rh, Pd, Ag, Sn, Sb, Re, Os, Ir, Pt, Hg, Pb, Bi and Po.

5. 2. The polar group-containing olefin copolymer according to claim 1, wherein the ratio of the molar content of the structural unit (C) to the sum of the molar contents of the structural unit (B) and the structural unit (C) is 1 to 99 mol%.

6. 2. The polar group-containing olefin copolymer according to claim 1, wherein the ratio of the sum of the molar contents of the structural unit (B) and the structural unit (C) to the sum of the molar contents of each structural unit in the polar group-containing olefin copolymer is 0.01 to 20.00 mol%.

7. The polar group-containing olefin copolymer according to claim 1 , wherein the structural unit (A) is a structural unit derived from ethylene.

8. An olefin-based resin composition comprising the polar group-containing olefin copolymer according to any one of claims 1 to 7.

9. A molded article comprising the olefin resin composition according to claim 8.

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