JP7377065B2 - Ethylene copolymer composition and its uses - Google Patents

Description

The present invention relates to an ethylene copolymer composition, a foam made of the composition, and uses thereof. Specifically, the present invention relates to a composition containing two different types of ethylene/α-olefin copolymers, a foam made of the composition, and uses thereof.

Cross-linked resin foams are also used in footwear or footwear parts, such as the soles (mainly midsoles) of sports shoes. This is because footwear or footwear parts are required to be lightweight, suppress deformation due to long-term use, and have mechanical strength and rebound resilience that can withstand harsh usage conditions.

Conventionally, cross-linked foams made of peroxide cross-linked ethylene-vinyl acetate copolymer (EVA) have been widely used for shoe soles. Cross-linked foam molded using this ethylene/vinyl acetate copolymer has a relatively high specific gravity and a large compression set, so when used for shoe soles, for example, it is heavy, and after long-term use There is a problem in that the mechanical strength such as impact resilience is lost as the material is compressed. For this reason, in order to further improve the compression set and mechanical strength of foams based on ethylene/vinyl acetate copolymers, we have developed ethylene/1-butene rubber (EBR), which has a higher crosslinking efficiency than ethylene/vinyl acetate copolymers. Blends of polyolefin rubbers such as ethylene octene rubber (EOR) have been attempted.

It is also known that materials with lower crystallinity have better impact resilience, so when particularly high impact resilience is required, ethylene-vinyl acetate copolymer (EVA) and ethylene-propylene-diene copolymer are recommended. (EPDM) was attempted. However, in that case, there is a problem that heat shrinkability and mechanical strength are insufficient, and there have been cases in which a highly crystalline polyolefin rubber is further added to supplement the mechanical strength.

On the other hand, ethylene/α-olefin copolymers have been used for various purposes. For example, crosslinked foams made using ethylene/α-olefin copolymers have high mechanical strength, are lightweight, and are flexible, so they can be used in architectural exterior materials, interior materials, automotive parts such as door glass runs, and packaging materials. , used in daily necessities. Here, non-crosslinked foams achieve weight reduction but have low mechanical strength. Therefore, when using foams for the above-mentioned applications, crosslinking of the resin is performed to strengthen the foam inside the foam. By bonding molecular chains, mechanical strength is improved.

The applicant of the present application has discovered that a crosslinked foam using an ethylene/α-olefin copolymer is suitable as a lightweight material for footwear parts, and has been conducting various studies. Specifically, foams made of compositions made of an ethylene polymer and EPDM (see Patent Document 1), foams made of compositions containing an ethylene/α-olefin copolymer having a vinyl group (Patent Document 2) , Patent Document 3) have found that it has a low specific gravity and a small compression set, and is suitable for footwear parts. It has also been found that an uncrosslinked foam made of a composition containing two types of ethylene/1-butene copolymers with different densities has excellent interlayer adhesion (see Patent Document 4).

Furthermore, Patent Document 5 discloses that a crosslinked foam having high hardness and low compression set obtained using a foamable compound containing an ethylene/α-olefin copolymer having a vinyl group is useful for footwear applications. It is written that.

International publication number 2007/132731 International publication number 2015/129414 Japanese Patent Application Publication No. 2008-308619 Japanese Patent Application Publication No. 2004-43606 Special table 2015-521670 publication

The present invention relates to a composition capable of producing a crosslinked foam that is suitable for use in footwear parts such as soles and has well-balanced properties such as lightness, heat shrinkability, compression set, and mechanical strength. An object of the present invention is to provide a foam made of foam and footwear parts using the same.

The present invention relates to the following [1] to [15].
[1]
An ethylene-based copolymer formed by copolymerizing only ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies all of the following requirements (a), (b), (c), and (d). Copolymer (A) and
An ethylene copolymer ( ^B ) An ethylene copolymer composition characterized by comprising;
(a) The vinyl group content per 1000 carbon atoms as determined by ¹ H-NMR is in the range of 0.003 to 0.3.
(b) MFR ₁₀ /MFR _2.16 is in the range of 7 to 20. (However, MFR ₁₀ is the melt flow rate measured at 190℃ and 10kg load according to the method of ASTM D1238, and MFR _2.16 is the melt flow rate measured at 190℃ and 2.16kg load according to the method of ASTM D1238. .)
(c) The density is in the range of 0.875 to 0.910 g/cm ³ .
(d) The melt flow rate (MFR _2.16 ) measured by the method of ASTM D1238 at 190°C and a load of 2.16 kg is in the range of 0.01 to 200 g/10 minutes.

[2]
The ethylene copolymer (A) has a content of structural units derived from ethylene in the range of 60 to 98 mol%, and a content of structural units derived from α-olefin having 3 to 20 carbon atoms is 2 to 40 mol%. % of the ethylene copolymer composition according to [1].
[3]
The ethylene copolymer composition according to [1] or [2], wherein the ethylene copolymer (A) has a melting point in the range of 50 to 120°C.

[4]
The ethylene copolymer composition according to any one of [1] to [3], wherein the ethylene copolymer (A) is an ethylene/1-butene copolymer.
[5]
The mass ratio [(A)/(B)] of the ethylene copolymer (A) and the ethylene copolymer (B) is in the range of 5/95 to 80/20. The ethylene copolymer composition according to any one of [1] to [4].

[6]
The ethylene copolymer composition according to any one of [1] to [5], further comprising an ethylene/polar monomer copolymer (C).
[7]
The mass ratio [(A)/(C)] of the ethylene copolymer (A) and the ethylene/polar monomer copolymer (C) is in the range of 1/99 to 39/61. The ethylene copolymer composition according to [6].

[8]
The ethylene copolymer composition according to any one of [1] to [7], further comprising a blowing agent (D), a crosslinking agent (E), or a combination thereof.
[9]
The ethylene copolymer composition according to any one of [1] to [8], further comprising a crosslinking aid (F).

[10]
A foam obtained by crosslinking and foaming the ethylene copolymer composition according to [8] or [9].
[11]
A laminate comprising a layer made of the foam described in [10] and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather.

[12]
Footwear characterized by using the foam described in [10] or the laminate described in [11].
[13]
A footwear component characterized by using the foam described in [10] or the laminate described in [11].

[14]
The footwear component according to item [13], wherein the footwear component is a midsole, an inner sole, or a sole.
[15]
A method for producing a foam, comprising the step of foaming the ethylene copolymer composition according to any one of [1] to [9].

According to the present invention, a composition is suitable for use in footwear parts such as soles, and is capable of producing a crosslinked foam having well-balanced and excellent properties such as lightness, heat shrinkability, compression set, and mechanical strength; Foams and laminates using the composition, and footwear parts and footwear using the same can be provided.

The present invention will be explained in detail below.
<Ethylene copolymer composition>
The ethylene copolymer composition according to the present invention includes an ethylene copolymer (A) and an ethylene copolymer (B), which will be described later. Further, if necessary, an ethylene/polar monomer copolymer (C), a blowing agent (D), a crosslinking agent (E), and other components can be further included.

Ethylene copolymer (A)
The ethylene copolymer (A) according to the present invention is a copolymer consisting only of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably ethylene and an α-olefin having 3 to 10 carbon atoms. It is a copolymer with That is, the ethylene copolymer (A) according to the present invention is a copolymer consisting of a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 20 carbon atoms.

Examples of α-olefins having 3 to 20 carbon atoms which are copolymerization components include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1 -octene, 1-decene, 1-dodecene, 1-tetradecene, etc. The α-olefin having 3 to 20 carbon atoms is preferably an α-olefin having 3 to 10 carbon atoms. The α-olefin having 3 to 20 carbon atoms, which is a copolymerization component, may be used alone or in combination of two or more types. One type may be used alone, or two or more types may be used.
Among these, the ethylene copolymer (A) according to the present invention is particularly preferably an ethylene/1-butene copolymer.

The type of α-olefin constituting the ethylene copolymer (A) is clear depending on the type of copolymer monomer used to produce the ethylene copolymer (A), but the α-olefin in the ethylene copolymer (A) - The type of olefin can be determined by, for example, measuring the ¹³ C-NMR spectrum of a sample obtained by uniformly dissolving about 200 mg of an ethylene copolymer in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube at a temperature of 120°C and a frequency of 25.05 MHz. , a spectral width of 1500 Hz, a pulse repetition time of 4.2 seconds, and a 45° pulse width of 6 μsec.

In the present invention, the content of ethylene-derived structural units (ethylene content) in the ethylene copolymer (A) is not particularly limited, but is usually 50 to 99 mol% of the total structural units, preferably It is in the range of 60 to 98 mol%, more preferably 75 to 97 mol%. In addition, the content of structural units derived from α-olefins having 3 to 20 carbon atoms (α-olefin content) in the ethylene copolymer (A) is usually 1 to 50 mol% of the total structural units, preferably It is in the range of 2 to 40 mol%, more preferably 3 to 25 mol%.

The ethylene copolymer (A) according to the present invention satisfies the following requirements (a), (b), (c) and (d) at the same time.
(a) The vinyl group content per 1000 carbon atoms as determined by ¹ H-NMR is in the range of 0.003 to 0.3.
(b) MFR ₁₀ /MFR _2.16 is in the range of 7 to 20.
(c) The density is in the range of 0.875 to 0.910 g/cm ³ .
(d) Melt flow rate (MFR _2.16 ) is in the range of 0.01 to 200 g/10 minutes.

Each of these requirements will be further explained below.
(a) Vinyl group content
The ethylene copolymer (A) according to the present invention has a vinyl group content per 1000 carbon atoms determined by ¹ H-NMR of 0.003 to 0.3, preferably 0.01 to 0. The number is in the range of 2, more preferably 0.02 to 0.1, and still more preferably 0.025 to 0.09.
A specific method for measuring the vinyl group content (amount of vinyl double bonds) will be described in detail in the measurement and evaluation methods of Examples described later.

In the ethylene copolymer (A) according to the present invention, the vinyl group is usually present at the terminal end of the copolymer. The ethylene copolymer (A) according to the present invention has a content of vinyl groups per 1000 carbon atoms within the above range, and has crosslinkability. It is preferable that the vinyl group content is within the above range because the resulting molded product has excellent mechanical strength. If the content of vinyl groups exceeds 0.3 per 1,000 carbon atoms in the ethylene copolymer (A), the amount of vinyl groups in the copolymer will be too large, resulting in crosslinking and polymerization during thermoforming. Cutting of the combined main chain becomes excessively likely to occur, which may cause problems such as fluctuations in MFR _2.16 during molding and discoloration.

(b) MFR ₁₀ /MFR _2.16
The ethylene copolymer (A) according to the present invention has an MFR ₁₀ /MFR _2.16 of 7 to 20, preferably 7.2 to 15, more preferably 7.5 to 12. Here, MFR ₁₀ is the melt flow rate (g/10 minutes) measured at 190°C and 10 kg load according to the method of ASTM D1238, and MFR2.16 is the melt flow rate measured at 190°C and 2.16 kg load according to the method of ASTM D1238. This is the measured melt flow rate (g/10 minutes).

MFR ₁₀ /MFR _2.16 is a value that is considered to be one of the indicators of the degree of long chain branching of a copolymer, and when the MFR ₁₀ /MFR _2.16 value is in the above range, it is specified that the copolymer has long chain branching. be done. When the MFR ₁₀ /MFR _2.16 value is less than 7, it indicates that there is little long chain branching. If the MFR ₁₀ /MFR _2.16 value of the ethylene copolymer is less than 7, when a crosslinked foam is produced from a composition containing a large amount of the ethylene copolymer, the accuracy of the shape of the crosslinked foam obtained will be low, and the crosslinked foam will not be as accurate. There may be variations in the dimensions. Furthermore, if the MFR ₁₀ /MFR _2.16 value of the ethylene copolymer is too large, exceeding 20, physical properties such as strength may deteriorate.

(c) Density The ethylene copolymer (A) according to the present invention has a density of 0.875 to 0.910 g/cm ³ , preferably 0.876 to 0.910 g/cm ³ , more preferably 0.876 ~0.908g/cm ³ . Note that the density of the ethylene copolymer (A) is a value measured at 23° C. according to ASTM D1505. When the density satisfies such a range, the resulting molded product or crosslinked foam has an excellent balance between flexibility and strength, and between rigidity and impact strength, which is preferable.

(d) Melt flow rate (MFR _2.16 )
The ethylene copolymer (A) according to the present invention has a melt flow rate (MFR _2.16 ) in the range of 0.01 to 200 g/10 minutes as measured by the method of ASTM D1238 at 190°C and a load of 2.16 kg. , preferably in the range of 0.1 to 100 g/10 minutes, more preferably 0.1 to 40 g/10 minutes, even more preferably 0.1 to 25 g/10 minutes, particularly preferably 0.1 to 10 g/10 minutes. It is desirable to have one.

The melt flow rate (MFR _2.16 ) of the ethylene copolymer (A) tends to decrease as the molecular weight increases. The method for adjusting the molecular weight will be described in the section "Production of ethylene copolymer (A)". It is preferable that MFR _2.16 is less than the above upper limit value in order to improve the strength of the obtained molded product, and that MFR _2.16 is more than the above lower limit value, it is preferable that the ethylene polymer (A) has a flow rate during melt molding. This is preferable in terms of improved properties.

(e) Mw/Mn
The ethylene copolymer (A) according to the present invention is not particularly limited, but is calculated as the ratio of the weight average molecular weight Mw determined from the measured value by gel permeation chromatography (GPC) and the number average molecular weight Mn. The molecular weight distribution (Mw/Mn) is preferably 1.5 to 3.5, more preferably 1.5 to 3.0. Mw/Mn can be set within the above range by appropriately selecting the polymerization catalyst as described in the section of the olefin polymerization catalyst. Furthermore, it is preferable that the amount is within the above range from the viewpoint of improving melt moldability and strength of the obtained molded product.

(f) Melting point (Tm)
The ethylene copolymer (A) according to the present invention is not particularly limited, but has a melting point (Tm) determined from a DSC endothermic curve of usually 40 to 130°C, preferably 50 to 120°C, or more. Preferably it is in the range of 55 to 110°C. It is preferable that the melting point of the ethylene copolymer (A) is within the above range from the viewpoint of balance between impact resilience and thermal shrinkage.

<Method for producing ethylene copolymer (A)>
The ethylene copolymer (A) according to the present invention may be one that satisfies the above-mentioned requirements (a), (b), (c), and (d), and there are no particular limitations on the manufacturing method thereof. However, it can be suitably produced, for example, by copolymerizing ethylene and at least one α-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst.

- Catalyst for olefin polymerization The ethylene copolymer (A) of the present invention has the above-mentioned characteristics, and the method for producing it is not limited in any way, but for example, the following catalyst components [A] and [ It can be produced by copolymerizing ethylene and one or more selected from α-olefins having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst consisting of [B].
[A] A crosslinked metallocene compound represented by the following general formula [I].

（式［Ｉ］中、Ｍは遷移金属を表し、ｐは遷移金属の原子価を表し、Ｘは同一でも異なっていてもよく、それぞれは水素原子、ハロゲン原子または炭化水素基を表し、Ｒ¹およびＲ²は同一でも異なっていてもよいＭに配位したπ電子共役配位子を表し、ＱはＲ¹とＲ²とを架橋する２価の基を表す。）

(In formula [I], M represents a transition metal, p represents the valence of the transition metal, X may be the same or different, each represents a hydrogen atom, a halogen atom, or a hydrocarbon group, and R ¹ and R ² represent a π-electron conjugated ligand coordinated to M, which may be the same or different, and Q represents a divalent group bridging R ¹ and R ^2. )

[B] (b-1) organoaluminumoxy compound,
(b-2) a compound that reacts with the metallocene compound [A] to form an ion pair; and (b-3) at least one compound selected from organoaluminum compounds.

Copolymerization is carried out, for example, by solution polymerizing one or more monomers selected from ethylene and α-olefin in the presence of such an olefin polymerization catalyst at a temperature of 0 to 200°C in the presence of a solvent. be able to.

However, the ethylene copolymer (A) according to the present invention is not limited to the above production method as long as it satisfies the above-mentioned characteristics. For example, in copolymerization, a metallocene having a structure different from the above formula [I] A compound may be used, a co-catalyst other than the catalyst component [B] may be used, or two or more known ethylene copolymers may be used for reactor blending, physical blending, etc. It may be prepared by any method.

Hereinafter, ethylene-based copolymerization in which ethylene and one or more types of α-olefins having 3 to 20 carbon atoms are copolymerized in the presence of an olefin polymerization catalyst containing catalyst components [A] and [B] The above-mentioned method for producing the composite (A) will be further explained.

Catalyst component [A]
Catalyst component [A] is a crosslinked metallocene compound represented by the above formula [I]. In the above formula [I], examples of the transition metal represented by M include Zr, Ti, Hf, V, Nb, Ta, and Cr, and preferred transition metals are Zr, Ti, and Hf, and more preferred transition metals are Zr, Ti, and Hf. The transition metal is Zr or Hf.

In general formula [I], the π-electron conjugated ligands represented by R ¹ and R ² include η-cyclopentadienyl structure, η-benzene structure, η-cycloheptatrienyl structure, and η-cyclo Examples include ligands having an octatetraene structure, and a particularly preferred ligand is a ligand having an η-cyclopentadienyl structure. Examples of the ligand having an η-cyclopentadienyl structure include a cyclopentadienyl group, an indenyl group, a hydrogenated indenyl group, and a fluorenyl group. These groups are further substituted with a halogen atom, a hydrocarbon group such as alkyl, aryl, aralkyl, alkoxy, or aryloxy, a silyl group containing a hydrocarbon group such as trialkylsilyl group, or a linear or cyclic alkylene group. Good too.

In the general formula [I], the group bridging R ¹ and R ² represented by Q is not particularly limited as long as it is a divalent group, but for example, a straight chain or branched alkylene group, an unsubstituted or Examples include substituted cycloalkylene groups, alkylidene groups, unsubstituted or substituted cycloalkylidene groups, unsubstituted or substituted phenylene groups, silylene groups, dialkyl-substituted silylene groups, germyl groups, and dialkyl-substituted germyl groups.

As the catalyst component [A], metallocene complexes used in the examples described later can be specifically exemplified, but the catalyst component [A] is not limited to these compounds.
Such catalyst component [A] is preferably used together with catalyst component [B] as an olefin polymerization catalyst.

Catalyst component [B]
When catalyst component [A] is used as a component of an olefin polymerization catalyst for producing the ethylene copolymer (A), the olefin polymerization catalyst includes (b-1) an organoaluminumoxy compound, (b-2) a catalyst It is preferable to include a catalyst component [B] composed of a compound that reacts with component [A] to form an ion pair, and at least one compound selected from (b-3) organoaluminum compounds. Here, the catalyst component [B] is preferably used in any one of the following embodiments [c1] to [c4] from the viewpoint of polymerization activity and properties of the produced olefin polymer.
[c1] (b-1) Organoaluminumoxy compound only,
[c2] (b-1) organoaluminumoxy compound and (b-3) organoaluminum compound,
[c3] (b-2) a compound that reacts with the catalyst component [A] to form an ion pair; and (b-3) an organoaluminum compound;
[c4] A compound that reacts with (b-1) an organoaluminumoxy compound and (b-2) catalyst component [A] to form an ion pair.

However, when using a metallocene compound in which Q is a silylene group in the general formula [I] as the catalyst component [A], as the component [B], it reacts with the catalyst component [A] (b-2) to form ions. Compounds that form a pair are not used, and only [c1] and [c2] are employed even in the above-mentioned preferred [B] components; [c1] to [c4].

Each component that can constitute the catalyst component [B] will be specifically explained below.
(b-1) Organoaluminumoxy compound
As the organoaluminumoxy compound (b-1), conventionally known aluminoxane can be used as is. Specifically, compounds represented by the following general formula [II] and/or general formula [III] can be mentioned.

（式［II］または［III］中、Ｒは炭素数１～１０の炭化水素基、ｎは２以上の整数を示す。）で代表される化合物を挙げることができ、特にＲがメチル基であるメチルアルミノキサンでｎが３以上、好ましくは１０以上のものが利用される。（一般式［II］または［III］においてRがメチル基である有機アルミニウムオキシ化合物を、以下「メチルアルミノキサン」と呼ぶ場合がある。）

(In the formula [II] or [III], R is a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 2 or more.) In particular, R is a methyl group. A certain methylaluminoxane in which n is 3 or more, preferably 10 or more is used. (An organoaluminumoxy compound in which R is a methyl group in general formula [II] or [III] may be hereinafter referred to as "methylaluminoxane.")

Furthermore, as the organoaluminumoxy compound (b-1), it is also preferable to use a methylaluminoxane analog that dissolves in saturated hydrocarbons, and examples thereof include modified methylaluminoxane such as the following general formula [IV].

（式［IV］中、Ｒは炭素数２～２０の炭化水素基、ｍ、ｎは２以上の整数を示す。）

(In formula [IV], R is a hydrocarbon group having 2 to 20 carbon atoms, and m and n are integers of 2 or more.)

The modified methylaluminoxane represented by the general formula [IV] is prepared using trimethylaluminum and an alkyl aluminum other than trimethylaluminum (for example, the manufacturing method is disclosed in US4960878, US5041584, etc.), and is available from manufacturers such as Tosoh Finechem Co., Ltd. Products prepared using aluminum and triisobutylaluminum, in which R is an isobutyl group, are commercially produced under the trade names MMAO and TMAO (for example, see "Tosoh Research and Technical Report" Vol. 47, 55 (2003)). ).

Furthermore, as the organoaluminumoxy compound (b-1), benzene-insoluble organoaluminumoxy compounds exemplified in JP-A-2-78687 may be used, and boron represented by the following general formula [V] may be used. An organoaluminumoxy compound containing the above may also be used.

（式［V］中、Ｒ^cは炭素原子数が１～１０の炭化水素基を示す。Ｒ^dは、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子または炭素原子数が１～１０の炭化水素基を示す。）
なお、上述した（b-1）有機アルミニウムオキシ化合物中には若干の有機アルミニウム化合物が混入していても差し支えない。

(In formula [V], R ^c represents a hydrocarbon group having 1 to 10 carbon atoms. R ^d may be the same or different from each other, and R d may be a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 10 carbon atoms. )
Note that there is no problem even if some organoaluminum compound is mixed in the above-mentioned (b-1) organoaluminumoxy compound.

(b-2) Compound that reacts with the catalyst component [A] to form an ion pair A compound (b-2) that reacts with the catalyst component [A] to form an ion pair (hereinafter referred to as "ionic compound (b-2)"-2)". Examples include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in JP-A-3-207703, JP-A-3-207704, and USP5321106. Furthermore, examples of the ionic compound (b-2) include heteropoly compounds and isopoly compounds.

In the present invention, the ionic compound (b-2) preferably employed is a compound represented by the following general formula [VI].

In formula [VI], R ^{e +} includes H ⁺ , a carbenium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptyltrienyl cation, a ferrocenium cation having a transition metal, and the like. R ^f to R ⁱ may be the same or different and are organic groups, preferably aryl groups.

Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris(methylphenyl)carbenium cation, and tris(dimethylphenyl)carbenium cation.

Specifically, the ammonium cation includes trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation. , N, N-dialkylanilinium cations such as N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation, diisopropylammonium cation, dicyclohexyl Examples include dialkylammonium cations such as ammonium cations.

Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris(methylphenyl)phosphonium cation, and tris(dimethylphenyl)phosphonium cation.

Among the above, R ^e+ is preferably carbenium cation, ammonium cation, etc., and particularly preferably triphenylcarbenium cation, N, N-dimethylanilinium cation, and N, N-diethylanilinium cation.

Specifically, the ionic compound (b-2) which is a carbenium salt includes triphenylcarbenium tetraphenylborate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(3,5- Examples include ditrifluoromethylphenyl)borate, tris(4-methylphenyl)carbeniumtetrakis(pentafluorophenyl)borate, and tris(3,5-dimethylphenyl)carbeniumtetrakis(pentafluorophenyl)borate.

Examples of the ionic compound (b-2) that is an ammonium salt include trialkyl-substituted ammonium salts, N,N-dialkylanilinium salts, and dialkylammonium salts.

Specific examples of the ionic compound (b-2) which is a trialkyl-substituted ammonium salt include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium Tetrakis(p-tolyl)borate, Trimethylammoniumtetrakis(o-tolyl)borate, Tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, Triethylammoniumtetrakis(pentafluorophenyl)borate, Tripropylammoniumtetrakis(pentafluorophenyl)borate phenyl)borate, tripropylammonium tetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(4-trifluoromethyl) phenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-ditrifluoromethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(o-tolyl)borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethyl Ammonium tetrakis(p-tolyl)borate, Dioctadecylmethylammoniumtetrakis(o-tolyl)borate, Dioctadecylmethylammoniumtetrakis(pentafluorophenyl)borate, Dioctadecylmethylammoniumtetrakis(2,4-dimethylphenyl)borate, Dioctadecyl Methylammonium tetrakis(3,5-dimethylphenyl)borate, dioctadecylmethylammoniumtetrakis(4-trifluoromethylphenyl)borate, dioctadecylmethylammoniumtetrakis(3,5-ditrifluoromethylphenyl)borate, dioctadecylmethylammonium, etc. can be mentioned.

Specifically, the ionic compound (b-2) which is an N,N-dialkylanilinium salt includes, for example, N,N-dimethylanilinium tetraphenylborate, N,N-dimethylanilinium tetrakis(pentafluorophenyl ) borate, N,N-dimethylanilinium tetrakis(3,5-ditrifluoromethylphenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N ,N-diethylanilinium tetrakis(3,5-ditrifluoromethylphenyl)borate, N,N-2,4,6-pentamethylanilinium tetraphenylborate, N,N-2,4,6-pentamethylanili Examples include nium tetrakis(pentafluorophenyl)borate.

Specific examples of dialkylammonium salts include di(1-propyl)ammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium tetraphenylborate, and the like.

As other ionic compounds (b-2), ionic compounds disclosed by the present applicant (Japanese Patent Application Laid-Open No. 2004-51676) can also be used without restriction.
The above ionic compound (b-2) may be used alone or in a mixture of two or more.

(b-3) Organoaluminum compound As the organoaluminum compound (b-3), for example, an organoaluminum compound represented by the following general formula [VII], a Group 1 metal and aluminum represented by the following general formula [VIII] Examples include complex alkylated products with.

R ^a _m Al (OR ^b ) _n H _p X _q … [VII]
(In formula [VII], R ^a and R ^b may be the same or different from each other and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, and X represents a halogen atom, m is 0<m≦3, n is 0≦n<3, p is 0≦p<3, q is a number of 0≦q<3, and m+n+p+q=3.)

Specific examples of the organoaluminum compound represented by the above general formula [VII] include tri-n-alkylaluminum such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, trihexylaluminum, and trioctylaluminum;
Tri-branched alkyl aluminum such as triisopropyl aluminum, triisobutyl aluminum, tri sec-butyl aluminum, tri tert-butyl aluminum, tri 2-methylbutyl aluminum, tri 3-methylhexyl aluminum, tri 2-ethylhexyl aluminum;
Tricycloalkyl aluminum such as tricyclohexyl aluminum and tricyclooctyl aluminum;
triaryl aluminum such as triphenyl aluminum and tritolyl aluminum;
Dialkyl aluminum hydride such as diisopropyl aluminum hydride, diisobutyl aluminum hydride;
Isoprenyl aluminum, etc., represented by the general formula (iC ₄ H ₉ ) _x Al _y (C ₅ H ₁₀ ) _z (in the formula, x, y, and z are positive numbers, and z≦2x), etc. alkenylaluminum;
Alkylaluminum alkoxides such as isobutylaluminum methoxide and isobutylaluminum ethoxide;
Dialkyl aluminum alkoxides such as dimethyl aluminum methoxide, diethylaluminum ethoxide, dibutyl aluminum butoxide;
Alkylaluminium sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide;
Partially alkoxylated alkyl aluminum having an average composition of the general formula R ^a _2.5 Al(OR ^b ) _0.5 ;
Alkylaluminum aryoxides such as diethylaluminium phenoxide and diethylaluminium (2,6-di-t-butyl-4-methylphenoxide);
Dialkyl aluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride;
Alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide;
partially halogenated alkyl aluminums such as alkyl aluminum dihalides such as ethylaluminum dichloride;
Dialkyl aluminum hydride such as diethylaluminum hydride and dibutyl aluminum hydride;
Other partially hydrogenated alkyl aluminum dihydrides such as ethyl aluminum dihydride, propyl aluminum dihydride;
Mention may be made of partially alkoxylated and halogenated alkylaluminiums, such as ethylaluminum ethoxy chloride, butylaluminum butoxychloride, ethylaluminum ethoxybromide, and the like.

M ² AlR ^a ₄ … [VIII]
(In formula [VIII], M ² represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms.) Complex alkylated product of Group 1 metal and aluminum. Examples of such compounds include LiAl(C ₂ H ₅ ) ₄ and LiAl(C ₇ H ₁₅ ) ₄ .

Compounds similar to the compound represented by the above general formula [VII] can also be used, such as organoaluminum compounds in which two or more aluminum compounds are bonded via a nitrogen atom. Specific examples of such compounds include (C ₂ H ₅ ) ₂ AlN(C ₂ H ₅ )Al(C ₂ H ₅ ) ₂ and the like.

(b-3) As the organic aluminum compound, trimethylaluminum and triisobutylaluminum are preferably used from the viewpoint of easy availability.

・Production of ethylene copolymer (A) The ethylene copolymer (A) according to the present invention is produced by combining at least ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of the above-mentioned olefin polymerization catalyst. It can be suitably produced by copolymerizing one type. Copolymerization can be performed, for example, by solution polymerization in the coexistence of a solvent. The polymerization temperature here is not particularly limited, but may be, for example, 140°C or higher, preferably 150°C or higher. It is preferable to carry out the copolymerization reaction at such a temperature because the MFR ₁₀ /MFR _2.16 of the resulting ethylene copolymer (A) can be increased and the vinyl group content can be increased. .

During polymerization, the usage and order of addition of each component can be arbitrarily selected, but for example, a method can be exemplified in which catalyst component [A] and catalyst component [B] are added to the polymerization vessel in any order. .
In the above method, two or more of each catalyst component may be contacted in advance.

When producing the ethylene copolymer (A) of the present invention by copolymerizing ethylene with at least one type of α-olefin having 3 to 20 carbon atoms using the above catalyst for olefin polymerization, the catalyst Component [A] is used in an amount of usually 10 ^-9 to 10 ^-1 mol, preferably 10 ^-8 to 10 ^-2 mol per liter of reaction volume.

Component (b-1) has a molar ratio [(b-1)/(M)] between component (b-1) and all transition metal atoms (M) in component [A] of usually 1 to 10,000, It is preferably used in an amount of 10 to 5,000. Component (b-2) has a molar ratio [(b-2)/(M)] of all transition metals (M) in component [A] of usually 0.5 to 50, preferably 1 to 20. It is used in such amount that Component (b-3) is used in an amount that is usually 0 to 5 mmol, preferably about 0 to 2 mmol per liter of polymerization volume.

Here, the molar ratio of ethylene to the α-olefin having 3 to 20 carbon atoms may be appropriately selected depending on the properties of the desired ethylene copolymer (A), and is not particularly limited. , ethylene:α-olefin=10:90 to 99.9:0.1, preferably ethylene:α-olefin=30:70 to 99.9:0.1, more preferably ethylene:α-olefin=50: 50-95.0:5.0.

Examples of α-olefins having 3 to 20 carbon atoms include linear or branched α-olefins such as propylene, 1-butene, 2-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, Examples include 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene. Among these α-olefins, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene are particularly preferably used. In the present invention, among these, α-olefins having 3 to 10 carbon atoms are more preferably used.

"Solution polymerization", which is preferably employed in the production of the ethylene copolymer (A), is a general term for methods in which polymerization is carried out in a state where the polymer is dissolved in a hydrocarbon solvent inert to the copolymerization reaction. The polymerization temperature in the solution polymerization according to the present invention can generally be in the range of about 0 to 200°C, but preferably 140°C or higher, more preferably 150°C or higher.

In the solution polymerization according to the present invention, if the polymerization temperature is lower than 0°C, the polymerization activity will be extremely reduced, making it impractical in terms of productivity. Content may decrease. In addition, in the polymerization temperature range of 0°C or higher, as the temperature increases, the solution viscosity during polymerization decreases, the heat of polymerization can be easily removed, and the vinyl group content of the ethylene copolymer (A) increases. do. However, if the polymerization temperature exceeds 200°C, the polymerization activity may be extremely reduced. The ethylene copolymer (A) according to the present invention has a relatively high MFR ₁₀ /MFR _2.16 value and has a relatively large vinyl group content, so the temperature of the ethylene copolymer (A) is 140°C or higher, preferably 150°C or higher. It is preferable to carry out the copolymerization at a relatively high temperature.

The polymerization pressure is usually normal pressure to 10 MPa gauge pressure, preferably normal pressure to 8 MPa gauge pressure, and the copolymerization can be carried out in any of the batch, semi-continuous, and continuous methods. The reaction time (average residence time when the copolymerization reaction is carried out in a continuous manner) varies depending on conditions such as catalyst concentration and polymerization temperature, and can be selected as appropriate, but is usually 1 minute to 3 hours, preferably The duration is 10 minutes to 2.5 hours. Furthermore, it is also possible to carry out the polymerization in two or more stages with different reaction conditions. The molecular weight of the obtained ethylene copolymer (A) can also be adjusted by changing the hydrogen concentration in the polymerization system and the polymerization temperature. Furthermore, it can also be adjusted by adjusting the amount of catalyst component [B] used. When hydrogen is added to the polymerization system, the appropriate amount is about 0.001 to 5,000 NL per 1 kg of the ethylene copolymer produced. Furthermore, the amount of vinyl groups in the resulting ethylene copolymer (A) can be increased by increasing the polymerization temperature and minimizing the amount of hydrogenation. In addition, the MFR ₁₀ /MFR _2.16 of the obtained ethylene copolymer (A) is an indicator that the larger the value is, the more long chain branching structures are contained, but in the case of coordination polymerization as in the examples below It is thought that the long chain branched structure in the ethylene copolymer (A) is generated by reinsertion of a molecular chain (macromonomer) having a terminal vinyl group generated by a β-hydrogen elimination reaction. . Therefore, the value of MFR ₁₀ /MFR _2.16 of the ethylene copolymer (A) is controlled by increasing or decreasing the ratio of macromonomer concentration to ethylene concentration in the solution ([macromonomer]/[ethylene]). be able to. Generally, when the [macromonomer]/[ethylene] is high, the amount of long chain branches in the ethylene polymer increases, and when the [macromonomer]/[ethylene] is low, the amount of long chain branches in the ethylene polymer increases. descend. Specific methods for increasing or decreasing [macromonomer]/[ethylene] in the solution include the following methods [1] to [4].

[1] Polymerization temperature The higher the polymerization temperature, the more likely the β-hydrogen elimination reaction will occur. Therefore, if the polymerization temperature is increased, the ratio of [macromonomer]/[ethylene] increases, and the amount of long chain branching in the ethylene copolymer increases.

[2] Polymer concentration If the polymer concentration in the solution is increased, the macromonomer concentration will also be relatively high, so [macromonomer]/[ethylene] will increase, and the amount of long chain branching in the ethylene copolymer will increase. To increase.

[3] Ethylene conversion rate If the ethylene conversion rate is increased, the ethylene concentration in the solution decreases, the [macromonomer]/[ethylene] ratio increases, and the amount of long chain branching in the ethylene copolymer increases. .

[4] Solvent type When the polymerization solvent is used as a low boiling point solvent, the ethylene concentration in the solution decreases, the [macromonomer]/[ethylene] ratio increases, and the amount of long chain branches in the ethylene copolymer increases. do.

In addition to controlling the β-hydrogen elimination reaction, it is also possible to increase or decrease the [macromonomer]/[ethylene]) by controlling the chain transfer reaction to Al, and the amount of long chain branching in the ethylene polymer. can also be changed.

The solvent used in solution polymerization is usually an inert hydrocarbon solvent, preferably a saturated hydrocarbon having a boiling point of 50° C. to 200° C. under normal pressure. Specific examples thereof include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Note that aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane also fall within the category of "inert hydrocarbon solvents" involved in the high-temperature solution polymerization of the present invention, and their use is prohibited. It is not intended to limit. As mentioned above, in the high-temperature solution polymerization according to the present invention, not only aromatic hydrocarbon-soluble organic aluminum oxy compounds, which have been frequently used in the past, but also MMAO, which is soluble in aliphatic hydrocarbons and alicyclic hydrocarbons, can be used. Modified methylaluminoxane such as can be used. As a result, if aliphatic hydrocarbons or alicyclic hydrocarbons are used as solvents for solution polymerization, the possibility of aromatic hydrocarbons being mixed into the polymerization system or the produced ethylene polymer can be almost completely eliminated. It became possible to do so. That is, the high-temperature solution polymerization method according to the present invention is characterized in that it can reduce the environmental load and minimize the impact on human health.

In order to suppress variations in physical property values, the ethylene copolymer (A) obtained by the polymerization reaction and other components added as desired are melted by any method and subjected to kneading, granulation, etc. is preferable.

- Graft modification The ethylene copolymer (A) of the present invention may be used after being partially or entirely graft modified with a polar monomer.

Examples of this polar monomer include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, epoxy group-containing ethylenically unsaturated compounds, aromatic vinyl compounds, unsaturated carboxylic acids or derivatives thereof, vinyl ester compounds, chlorinated Examples include vinyl and carbodiimide compounds.

As the polar monomer, unsaturated carboxylic acids or derivatives thereof are particularly preferred. Examples of unsaturated carboxylic acids or derivatives thereof include unsaturated compounds having one or more carboxylic acid groups, esters of compounds having carboxylic acid groups and alkyl alcohols, unsaturated compounds having one or more carboxylic anhydride groups, etc. Examples of the unsaturated group include a vinyl group, a vinylene group, and an unsaturated cyclic hydrocarbon group.

Specific compounds include, for example, acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid [trademark] (endocys-bicyclo[2.2.1] hepto -5-ene-2,3-dicarboxylic acid); or derivatives thereof, such as acid halides, amides, imides, anhydrides, and esters. Specific examples of such derivatives include maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate, and the like.

These unsaturated carboxylic acids and/or derivatives thereof can be used alone or in combination of two or more. Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, and maleic acid, nadic acid, or their acid anhydrides are particularly preferred.

Modification is obtained by graft polymerizing a polar monomer onto the object to be modified. When graft polymerizing the polar monomer as described above to the object to be modified, the polar monomer is usually used in an amount of 1 to 100 parts by weight, preferably 5 to 80 parts by weight, based on 100 parts by weight of the object to be modified. used. This graft polymerization is usually carried out in the presence of a radical generator.

As the radical generator, for example, the same radical generators as those listed below in the radical generator (C) can be used.

The radical generator can be used by being mixed with the object to be modified and the polar monomer as it is, but it can also be used after being dissolved in a small amount of an organic solvent. As this organic solvent, any organic solvent that can dissolve the radical generator can be used without particular limitation.

Further, when graft polymerizing a polar monomer onto the object to be modified, a reducing substance may be used. When a reducing substance is used, the amount of polar monomer grafted can be increased. Graft modification of the object to be modified with a polar monomer can be performed by a conventionally known method.

The amount of modification (the amount of polar monomer grafted) of the modified product obtained in this way is usually 0.1 to 50% by mass, preferably 0.2 to 30% by mass, when the modified product is 100% by mass, and The content is preferably 0.2 to 10% by mass.

When a part or all of the ethylene copolymer (A) of the present invention is graft-modified with a polar monomer and used, it has excellent adhesion and compatibility with other resins, and the wettability of the surface of the obtained molded product. may be improved.

Furthermore, when the content of a polar monomer, such as an unsaturated carboxylic acid and/or a derivative thereof, is within the above range, part or all of the ethylene copolymer (A) of the present invention is graft-modified and used. , exhibits high adhesive strength to polar group-containing resins (eg, polyester, polyvinyl alcohol, ethylene/vinyl alcohol copolymer, polyamide, PMMA, polycarbonate, etc.).

In addition, the graft-modified ethylene copolymer (A) obtained by graft-modifying part or all of the ethylene copolymer (A) of the present invention may be used within a range that does not impair the properties of the modified product. , other polymers such as thermoplastic resins and elastomers can be blended. Their formulation may be at the graft modification stage or mixed after modification.

Ethylene copolymer (B)
The ethylene copolymer (B) according to the present invention is a copolymer obtained by copolymerizing only ethylene and an α-olefin having 3 to 20 carbon atoms, preferably ethylene and an α-olefin having 3 to 20 carbon atoms. This is a copolymer formed by copolymerizing only 10 α-olefins. That is, the ethylene copolymer (B) according to the present invention is a copolymer consisting of a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 20 carbon atoms, and preferably, a structural unit derived from ethylene. It is a copolymer consisting of a structural unit derived from an α-olefin having 3 to 10 carbon atoms. The type of α-olefin having 3 to 20 carbon atoms, which is a copolymerization component, and the method for identifying it are the same as those for the ethylene copolymer (A).

In the present invention, the content of ethylene-derived structural units (ethylene content) in the ethylene copolymer (B) is not particularly limited, but is usually 50 to 99 mol% of the total structural units,
It is preferably in the range of 60 to 98 mol%, more preferably 70 to 95 mol%. In addition, the content of structural units derived from α-olefins having 3 to 20 carbon atoms (α-olefin content) in the ethylene copolymer (B) is usually 1 to 50 mol%, preferably 1 to 50 mol% of the total structural units. It is in the range of 2 to 40 mol%, more preferably 5 to 30 mol%.

The density of the ethylene copolymer (B) according to the present invention is usually 0.850 to 0.873 g/cm ³ , preferably 0.853 to 0.873 g/cm ³ , more preferably 0.855 to 0.873 g/cm 3 . It is in the range of 870 g/cm ³ . Note that the density of the ethylene copolymer (B) is a value measured at 23° C. according to ASTM D1505.

The ethylene copolymer (B) according to the present invention is not particularly limited, but is calculated as the ratio of the weight average molecular weight Mw determined from the measured value by gel permeation chromatography (GPC) and the number average molecular weight Mn. The molecular weight distribution (Mw/Mn) is preferably 1.5 to 3.5, more preferably 1.5 to 3.0.

Although the ethylene copolymer (B) according to the present invention is not particularly limited, the melt flow rate (MFR _2.16 ) measured by the method of ASTM D1238 at 190°C and a load of 2.16 kg is usually 0. A desirable range is 1 to 100 g/10 minutes, preferably 0.1 to 80 g/10 minutes, and more preferably 0.1 to 40 g/10 minutes.

Such an ethylene copolymer (B) can be appropriately produced by a known method for producing a low-density ethylene/α-olefin copolymer, or a commercially available product may be used. In the present invention, commercially available products that can be suitably used as the ethylene copolymer (B) include (trade name: Tafmer (registered trademark), manufactured by Mitsui Chemicals, Inc.), (trade name: Engage (registered trademark)), trademark), manufactured by The Dow Chemical Company), etc.

In the ethylene copolymer composition of the present invention, the content of the ethylene copolymer (B) is not particularly limited, but the mass ratio [ (A)/(B)] is usually in the range of 1/99 to 95/5, preferably 5/95 to 80/20, more preferably 10/90 to 75/25. When the blending ratio of the ethylene copolymer (A) and the ethylene copolymer (B) satisfies such a range, it is preferable because it provides an excellent balance between impact resilience, thermal shrinkage, and mechanical properties.

Ethylene/polar monomer copolymer (C)
The ethylene copolymer composition of the present invention may contain an ethylene/polar monomer copolymer (C).
Examples of the polar monomer of the ethylene/polar monomer copolymer (C) according to the present invention include unsaturated carboxylic acids, salts thereof, esters thereof, amides thereof, vinyl esters, and carbon monoxide. More specifically, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride, lithium and sodium of these unsaturated carboxylic acids, Salts of monovalent metals such as potassium, salts of polyvalent metals such as magnesium, calcium, zinc, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate , unsaturated carboxylic acid esters such as ethyl methacrylate, isobutyl methacrylate, and dimethyl maleate, vinyl esters such as vinyl acetate and vinyl propionate, and one or more types of carbon monoxide and sulfur dioxide. I can do it.

More specifically, the ethylene/polar monomer copolymer (C) includes ethylene/unsaturated carboxylic acid copolymers such as ethylene/acrylic acid copolymers, ethylene/methacrylic acid copolymers, and the above-mentioned ethylene/unsaturated Ionomers in which some or all of the carboxyl groups of carboxylic acid copolymers are neutralized with the above metals, ethylene/methyl acrylate copolymers, ethylene/ethyl acrylate copolymers, ethylene/methyl methacrylate copolymers, Ethylene/unsaturated carboxylic acid ester copolymers such as ethylene/isobutyl acrylate copolymer, ethylene/n-butyl acrylate copolymer, ethylene/isobutyl acrylate/methacrylic acid copolymer, ethylene/n-butyl acrylate - Ethylene/unsaturated carboxylic acid ester/unsaturated carboxylic acid copolymers such as methacrylic acid copolymers, ionomers in which some or all of the carboxyl groups are neutralized with the above metals, and ethylene/vinyl acetate copolymers Typical examples include ethylene/vinyl ester copolymers such as .

Among these, copolymers of ethylene and polar monomers selected from unsaturated carboxylic acids, their salts, their esters, and vinyl acetate are particularly preferred, and in particular, ethylene/(meth)acrylic acid copolymers or their ionomers, and ethylene - (Meth)acrylic acid/(meth)acrylic acid ester copolymer or its ionomer, ethylene/vinyl acetate copolymer is preferred, and ethylene/vinyl acetate copolymer is most preferred.

The above-mentioned ethylene/polar monomer copolymer (C) preferably has a polar monomer content of usually 1 to 50% by mass, particularly 5 to 45% by mass, although it varies depending on the type of polar monomer. Considering moldability, mechanical strength, etc., such an ethylene/polar monomer copolymer should have a melt flow rate of 0.05 to 500 g/10 min at 190°C and a load of 2.16 kg, especially 0. It is preferable to use 1 to 100 g/10 minutes. Copolymers of ethylene and unsaturated carboxylic acids, unsaturated carboxylic esters, vinyl esters, etc. can be obtained by radical copolymerization at high temperature and high pressure. A copolymer of ethylene and a metal salt of an unsaturated carboxylic acid (ionomer) can be obtained by reacting an ethylene/unsaturated carboxylic acid copolymer with a corresponding metal compound.

When the ethylene/polar monomer copolymer (C) according to the present invention is an ethylene/vinyl acetate copolymer, the vinyl acetate content in the ethylene/vinyl acetate copolymer is usually 10 to 30% by mass, preferably 15% by mass. ~30% by weight, more preferably 15~25% by weight.

In addition, this ethylene/vinyl acetate copolymer has a melt flow rate (MFR; ASTM D1238, 190°C, load 2.16 kg) of usually 0.1 to 50 g/10 minutes, preferably 0.5 to 20 g/10 minutes. min, more preferably 0.5 to 5 g/10 min.

In the ethylene copolymer composition of the present invention, the ethylene/polar monomer copolymer (C) is an optional component, but when used, the resulting foam layer is made of polyurethane, rubber, leather, etc. It has excellent adhesion to other layers and is also preferred as a laminate.

In particular, when the ethylene/polar monomer copolymer (C) is a copolymer of ethylene and an unsaturated carboxylic acid, when used in the above ratio, the tear strength properties and other layers made of polyurethane, rubber, leather, etc. A composition that can provide a crosslinked foam with excellent adhesive properties can be obtained.

In the ethylene copolymer composition of the present invention, the content of the ethylene/polar monomer copolymer (C) (component (C)) is not particularly limited. The mass ratio [(A)/(C)] of (A) (component (A)) is usually 1/99 to 39/61, preferably 1/99 to 29/71, more preferably 1/99 to The range is 19/81. When the blending ratio of component (A) and component (C) satisfies such a range, it is preferable because moldability is excellent.

Foaming agent (D)
The ethylene copolymer composition of the present invention may contain a blowing agent (D) if necessary. The ethylene copolymer composition containing the blowing agent (D) is suitably used for producing foams and crosslinked foams.

When the ethylene copolymer composition of the present invention contains a blowing agent (D), the content depends on the type of blowing agent (D), but the content of the ethylene copolymer (A), ethylene copolymer The blowing agent (D) is 0% for a total of 100 parts by mass of the polymer (B) and optionally the ethylene/polar monomer copolymer (C) and other resin components (i.e. 100 parts by mass of all resin components). The amount is desirably in the range of .1 to 30 parts by weight, preferably 0.1 to 25 parts by weight, and more preferably 0.5 to 20 parts by weight.

In the present invention, as the blowing agent (D), either a chemical blowing agent or a physical blowing agent can be used.

Specifically, chemical blowing agents include:
azodicarbonamide (ADCA),
1,1'-azobis(1-acetoxy-1-phenylethane),
dimethyl-2,2'-azobisbutyrate,
dimethyl-2,2'-azobisisobutyrate,
2,2'-azobis(2,4,4-trimethylpentane),
1,1'-azobis(cyclohexane-1-carbonitrile),
Azo compounds such as 2,2'-azobis[N-(2-carboxyethyl)-2-methyl-propionamidine];
Nitroso compounds such as N,N'-dinitrosopentamethylenetetramine (DPT);
4,4'-oxybis(benzenesulfonylhydrazide),
Hydrazine derivatives such as diphenylsulfone-3,3'-disulfonylhydrazide;
Semicarbazide compounds such as p-toluenesulfonyl semicarbazide;
Organic pyrolytic blowing agents such as trihydrazinotriazine, and
Bicarbonates such as sodium bicarbonate and ammonium bicarbonate; carbonates such as sodium carbonate and ammonium carbonate;
Nitrite salts such as ammonium nitrite,
Examples include inorganic thermally decomposable blowing agents such as hydrogen compounds. Among these, azodicarbonamide (ADCA) and sodium hydrogen carbonate are particularly preferred.

Physical blowing agents that do not necessarily involve chemical reactions during foaming include various aliphatic hydrocarbons such as methanol, ethanol, propane, butane, pentane, and hexane; dichloroethane, dichloromethane, carbon tetrachloride, etc. Examples include various chlorinated hydrocarbons; organic physical blowing agents such as various fluorinated chlorinated hydrocarbons such as chlorofluorocarbons; and inorganic physical blowing agents such as air, carbon dioxide, nitrogen, argon, and water. Among these, carbon dioxide, nitrogen, and argon are the best because they do not require steaming, are inexpensive, and have extremely low environmental pollution and ignition potential.

When a physical foaming agent is used as the foaming agent (D) in the present invention, there is no decomposed residue of the foaming agent, so that mold staining can be prevented during crosslinking and foaming of the composition. Moreover, since the physical foaming agent is not in powder form, it has excellent kneading properties. In addition, when this physical foaming agent is used, it is possible to prevent the resulting foam from having an unpleasant odor (such as an ammonia odor generated when ADCA is decomposed).

Further, in the present invention, as the blowing agent (D), the above-mentioned chemical blowing agents can be used as long as they do not cause adverse effects such as odor and mold staining. These may be used alone, in combination of two or more, and in combination with a physical foaming agent and a chemical foaming agent.

As a storage method for physical blowing agents, for small-scale production, carbon dioxide, nitrogen, etc. can be used in a cylinder and supplied to injection molding machines, extrusion molding machines, etc. through pressure reducing valves. In some cases, the pressure is increased using a pump, etc., and then supplied to an injection molding machine, an extrusion molding machine, etc.

In addition, if it is a facility that manufactures foamed products on a large scale, a storage tank for liquefied carbon dioxide, liquefied nitrogen, etc. will be installed, and the gas will be vaporized through a heat exchanger, and then transferred to injection molding machines and extrusion molding machines via piping and pressure reducing valves. etc.
Further, in the case of a liquid physical foaming agent, the storage pressure is preferably in the range of 0.13 to 100 MPa.

When a chemical blowing agent is used as the blowing agent (D), the chemical blowing agent is an ethylene copolymer (A), an ethylene copolymer (B) and, if necessary, an ethylene/polar monomer copolymer (C ) and other resin components (i.e., 100 parts by mass of all resin components), usually 2 to 30 parts by mass, preferably 3 to 20 parts by mass, more preferably 5 to 15 parts by mass. used. However, the amount of the chemical blowing agent used can be increased or decreased as appropriate depending on the desired expansion ratio since the amount of gas generated varies depending on the type and grade of the blowing agent used.

In addition, when using a physical blowing agent as the blowing agent (D), the amount of the physical blowing agent to be added is appropriately determined depending on the desired expansion ratio. Usually 0.1 to 15 parts by mass based on a total of 100 parts by mass of the polymer (B) and, if necessary, the ethylene/polar monomer copolymer (C) and other resin components (i.e., 100 parts by mass of all resin components). , preferably 0.5 to 10 parts by mass.

The ethylene copolymer composition of the present invention may contain a foaming aid together with the foaming agent (D), if necessary. The foaming aid acts to lower the decomposition temperature of the foaming agent (D), promote decomposition, and homogenize the bubbles. Examples of such foaming aids include zinc oxide (ZnO), zinc stearate, organic acids such as salicylic acid, phthalic acid, stearic acid, and oxalic acid, and urea or its derivatives.

Crosslinking agent (E)
The ethylene copolymer composition of the present invention may contain a crosslinking agent (E) if necessary. The ethylene copolymer composition containing the crosslinking agent (E) is suitably used for producing crosslinked molded articles and crosslinked foams.

As the crosslinking agent (E), any radical generator that acts as a crosslinking agent can be used without particular limitation.
When the ethylene copolymer composition of the present invention contains a crosslinking agent (E), its content is appropriately determined depending on the characteristics of the resin component and the desired degree of crosslinking. A), the ethylene copolymer (B), and if necessary the ethylene/polar monomer copolymer (C) and other resin components, preferably based on a total of 100 parts by mass (i.e., 100 parts by mass of all resin components). is preferably in the range of 0.1 to 2.0 parts by weight, more preferably 0.3 to 1.8 parts by weight, even more preferably 0.6 to 1.6 parts by weight. When an ethylene copolymer composition containing the crosslinking agent (E) in such an amount is used, a molded article or a foam molded article having an appropriate crosslinked structure can be produced.

As the crosslinking agent (E), organic peroxides are preferably used, specifically,
dicumyl peroxide,
di-t-butyl peroxide,
2,5-dimethyl-2,5-di-(t-butylperoxy)hexane,
2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3,
1,3-bis(t-butylperoxyisopropyl)benzene,
1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,
n-butyl-4,4-bis(t-butylperoxy)valerate,
benzoyl peroxide,
p-chlorobenzoyl peroxide,
2,4-dichlorobenzoyl peroxide,
t-butyl peroxybenzoate,
t-butyl perbenzoate,
t-butylperoxyisopropyl carbonate,
diacetyl peroxide,
lauroyl peroxide,
Examples include organic peroxides such as t-butylcumyl peroxide. Among these, dicumyl peroxide is preferred.

When the ethylene copolymer composition of the present invention contains a crosslinking agent (E), it is also preferable to contain a crosslinking aid together with the crosslinking agent (E), if necessary. Examples of crosslinking aids include sulfur, p-quinonedioxime, p,p'-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N , N'-m-phenylene dimaleimide; or divinylbenzene, triallyl cyanurate (TAC), triallyl isocyanurate (TAIC).

In addition, as a crosslinking aid, polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate; polyfunctional methacrylate monomers such as vinyl butyrate and vinyl stearate; Examples include vinyl monomers. Among these, triallyl cyanurate (TAC) and triallyl isocyanurate (TAIC) are preferred.

In the ethylene copolymer composition of the present invention, such a crosslinking aid has a mass ratio of crosslinking aid to crosslinking agent (E) [crosslinking aid/crosslinking agent (E)] of 1/30 to 1/30. It is desirable to use the amount in an amount of 5/1, preferably 1/20 to 3/1, more preferably 1/15 to 2/1, particularly preferably 1/10 to 1/1.

Optional Components The ethylene copolymer composition of the present invention may contain components other than the above-mentioned components as optional components, as necessary, to the extent that the object of the present invention is not achieved.For example, fillers , heat-resistant stabilizers, weather-resistant stabilizers, flame retardants, hydrochloric acid absorbers, various additives such as pigments, and resin components other than the above-mentioned components (A) to (C). Examples of various additives include those known as additives that can be added to olefin resins.

Preparation of Ethylene Copolymer Composition The ethylene copolymer composition of the present invention can be prepared by mixing the above-mentioned components sequentially or simultaneously by a known method. The ethylene copolymer composition of the present invention is also preferably in the form of pellets, sheets, or the like.

The pellets of the ethylene copolymer composition of the present invention contain an ethylene copolymer (A), an ethylene copolymer (B), and, if necessary, an ethylene/polar monomer copolymer (C), a foamed Agent (D), crosslinking agent (E), and optional components such as additives are mixed in the above-mentioned proportions using a Henschel mixer, etc., and then mixed with a kneading machine such as a Banbury mixer, roll, or extruder to form the foaming agent (D). It can be prepared by melting and plasticizing at a temperature at which the crosslinking agent (E) and the crosslinking agent (E) do not decompose, uniformly mixing and dispersing it, and using a granulator. Examples of methods for crosslinking and foaming include crosslinking by heat treatment and crosslinking by ionizing radiation, as described later. In the case of crosslinking by heat treatment, the composition preferably contains a crosslinking agent (E) and a crosslinking aid (E). Further, in the case of crosslinking using ionizing radiation, a crosslinking aid may be added.

Further, the sheet of the ethylene copolymer composition of the present invention can be prepared, for example, by using the pellets obtained as described above using an extruder or a calendar molding machine. Alternatively, the components constituting the ethylene copolymer composition are kneaded using a Brabender or the like, and then formed into a sheet using a calendar roll, formed into a sheet using a press molding machine, or kneaded using an extruder. A foamable sheet in an uncrosslinked and unfoamed state can be prepared by a method of forming a sheet through a rear T-die or an annular die.
The ethylene copolymer composition of the present invention can be used for various molding applications such as injection molding and foam molding, and can also be suitably used for producing crosslinked products or crosslinked foams.

<Production of foam>
In the present invention, a foam such as a crosslinked foam can be manufactured using the above-described ethylene copolymer composition of the present invention. For producing the foam, an ethylene copolymer composition containing a blowing agent (D), a crosslinking agent (E), or a combination thereof is preferably used.

The ethylene copolymer composition used for producing the foam is in an uncrosslinked and unfoamed state, and may be in a molten state, or may be in the form of pellets or sheets solidified by cooling.
The foam of the present invention (non-crosslinked or crosslinked foam) can be prepared, for example, by the following method, although there are no particular limitations on the method for producing it.

For example, a sheet made of the ethylene copolymer composition of the present invention described above can be obtained using a calendar molding machine, a press molding machine, or a T-die extruder. When forming the sheet, it is preferable to form the sheet at a temperature below the decomposition temperature of the blowing agent (D) and the crosslinking agent (E) such as organic peroxide. It is preferable to form the sheet under temperature conditions that result in the following state.

As a method for producing a primary foam from a sheet made of an ethylene copolymer composition, for example, a mold heated at 130 to 200°C is heated to a temperature of 1.0 to 1.2 with respect to the volume of the mold. The primary foam (non-crosslinked ^or cross-linked foam). That is, a foam (non-crosslinked or crosslinked foam) is produced by heat treatment. Note that since the holding time depends on the thickness of the mold, it can be increased or decreased as appropriate beyond this range.

The shape of the mold for the (crosslinked) foam is not particularly limited, but a mold having a shape that allows a sheet to be obtained is usually used. It is preferable that this mold has a completely sealed structure so that gas generated during decomposition of the molten resin and the blowing agent does not escape. Further, as the mold, a mold with a tapered inner surface is preferable from the viewpoint of mold release properties of the resin.

In addition to the method described above, the foam of the present invention can also be produced by an extrusion foaming method in which the ethylene copolymer composition is extruded from an extruder, released into the atmosphere, and foamed at the same time. That is, a foam can be manufactured by heat treatment.

Alternatively, the ethylene polymer composition is injected into a mold at a temperature below the decomposition temperature of the blowing agent (D) and the crosslinking agent (E), and maintained at a temperature of, for example, about 130°C to 200°C within the mold. A method of crosslinking and foaming (injection foaming method) can also be mentioned. That is, a foam can be manufactured by heat treatment.

The foam obtained by the above method can be given a predetermined shape by compression molding. Examples of compression molding conditions at this time include: mold temperature of 130 to 200°C, mold clamping pressure of 30 to 300 kgf/cm ² , compression time of 5 to 60 minutes, and compression ratio of 1.1 to 3.0. , preferably in the range of 1.3 to 2.

In addition, in order to obtain a crosslinked foam by a crosslinking method using ionizing radiation irradiation, for example, an ethylene copolymer composition containing a blowing agent (D) which is an organic pyrolytic foaming agent is mixed with an organic pyrolyzable foam. The resulting kneaded product is melt-kneaded at a temperature below the decomposition temperature of the blowing agent, and the resulting kneaded product is formed into a sheet, for example, to obtain a sheet-like foam, and then ionizing radiation is applied to the obtained sheet-like foam. After crosslinking the sheet-like foam by irradiating a predetermined amount, the obtained sheet-like cross-linked foam is heated to a temperature higher than the decomposition temperature of the organic pyrolyzable foaming agent to foam it, thereby forming a sheet-like cross-linked foam. You can get a body. That is, a foam can be manufactured by heat treatment. As the ionizing radiation, α rays, β rays, γ rays, electron beams, neutron beams, X rays, etc. are used. Among these, cobalt-60 gamma rays and electron beams are preferably used.

The product shape of the foam includes, for example, a sheet shape, a thick board shape, a net shape, a molded product, and the like.
A secondary foam can be manufactured by applying a predetermined shape to the crosslinked foam obtained as described above by compression molding. Examples of compression molding conditions at this time include: mold temperature of 130 to 200°C, mold clamping pressure of 30 to 300 kgf/cm ² , compression time of 5 to 60 minutes, and compression ratio of 1.1 to 3.0. is within the range of

Among the above manufacturing methods, it is preferable to heat-treat the ethylene polymer composition to obtain a foam. The foam according to the present invention is preferably a crosslinked foam.

The foam of the present invention obtained by foaming the ethylene polymer composition of the present invention preferably has a specific gravity of 0.03 to 0.30. Furthermore, there are no particular restrictions on the compression set (CS, %) and specific gravity (d) of the foam according to the present invention, but it is preferable that the foam satisfies CS≦-279×(d)+95 to be lightweight and compression set. This is preferable because it can provide a foam with small distortion. The foam of this other embodiment is also preferably used in the laminate, footwear, or footwear parts described below.

<Laminated body>
The laminate of the present invention is a laminate having a layer made of the foam of the present invention described above and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather.

The above-mentioned polyolefins, polyurethanes, rubbers, leathers, and artificial leathers are not particularly limited, and conventionally known polyolefins, polyurethanes, rubbers, leathers, and artificial leathers can be used. Such a laminate is particularly suitable for use as footwear or footwear parts.

<Footwear and footwear parts>
The footwear or footwear parts of the present invention are made using the above-described foam or laminate of the present invention. Examples of footwear parts include shoe soles, shoe midsoles, inner soles, soles, and sandals. Since the footwear or footwear component of the present invention uses the foam or laminate of the present invention, it is lightweight and can suppress deformation due to long-term use.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

In the following Examples and Comparative Examples, various physical properties were measured or evaluated as follows.
[Evaluation of physical properties of copolymer]
Double bond amount
The amount of double bonds was determined by ¹ H-NMR measurement of the ethylene/α-olefin copolymer (“ECX400P nuclear magnetic resonance apparatus” manufactured by JEOL Ltd.). Here, as signals derived from double bonds, vinyl type double bonds, vinylidene type double bonds, 2-substituted olefin type double bonds, and 3-substituted olefin type double bonds are observed. The amount of double bonds was quantified from the integrated intensity of each signal. The main chain methylene signal of the ethylene/α-olefin copolymer was used as a chemical shift standard (1.2 ppm).

各式中、＊は水素原子以外の原子との結合手を示す。

In each formula, * indicates a bond with an atom other than a hydrogen atom.

The peaks of each hydrogen atom a to e are observed near the following.
・Peak of hydrogen atom a: 4.60 ppm
・Peak of hydrogen atom b: 4.85ppm
・Peak of hydrogen atom c: 5.10ppm
・Peak of hydrogen atom d: 5.25 ppm
・Peak of hydrogen atom e: 5.70ppm
The quantitative formula for the amount of double bonds is as follows.
・Amount of vinyl double bonds = {(integrated intensity of signal b) + (integrated intensity of signal e)}/3
・Amount of vinylidene double bonds = (integrated intensity of signal a)/2
・Disubstituted olefin type double bond amount = (integrated intensity of signal d)/2
・Trisubstituted olefin type double bond amount = (integrated intensity of signal c)

From these results, the vinyl group content per 1000 carbon atoms (vinyl double bond amount) and the vinylidene group content per 1000 carbon atoms (vinylidene double bond amount) were determined.

density d
Density d (g/cm ³ ) was determined at 23° C. according to ASTM D1505.
MFR
MFR (melt flow rate, g/10 min) was determined at 190° C. according to ASTM D1238. The measured value at a load of 2.16 kg was defined as MFR _2.16 , and the measured value at a load of 10 kg was defined as MFR ₁₀ .

Molecular weight distribution (Mw/Mn)
It was determined by gel permeation chromatography (GPC) using orthodichlorobenzene solvent at 140°C. The measurement was performed as follows using a gel permeation chromatograph Alliance GPC-2000 manufactured by Waters. The separation columns were two TSKgel GNH6-HT and two TSKgel GNH6-HTL, and the column sizes were 7.5 mm in diameter and 300 mm in length, the column temperature was 140°C, and the mobile phase was Using o-dichlorobenzene (Wako Pure Chemical Industries) and 0.025% by mass of BHT (Takeda Pharmaceutical) as an antioxidant, it was moved at 1.0 ml/min, the sample concentration was 15 mg/10 ml, and the sample injection amount was The volume was 500 μl, and a differential refractometer was used as a detector. Standard polystyrene was manufactured by Tosoh Co., Ltd. when the molecular weight was Mw<1000 and Mw>4×10 ⁶ , and manufactured by Pressure Chemical Co., Ltd. when 1000≦Mw≦4×10 ⁶ .

Melting point (Tm)
Using a differential scanning calorimeter (SII DSC220), about 5.0 mg of the sample was heated from 30° C. to 200° C. at a heating rate of 10° C./min in a nitrogen atmosphere, and held at that temperature for 10 minutes. It was further cooled down to 30°C at a temperature decreasing rate of 10°C/min, held at that temperature for 5 minutes, and then heated to 200°C at a temperature increasing rate of 10°C/min. The endothermic peak observed during this second temperature rise was defined as the melting peak, and the temperature at which the melting peak appeared was determined as the melting point (Tm).

[Evaluation of physical properties of crosslinked foam]
specific gravity
Specific gravity was measured according to JIS K7222. If the foam was a cube, the sample was sampled from within 20 mm or more from each of the four sides of the plane of maximum area, and with the skin remaining from the surface of the parallel plane. For example, in the case of a midsole, samples were prepared with skins left on both substantially parallel plane surfaces at least 20 mm inside each end.

Measurements are taken as an average of 5 parts of the foam. Further, the difference between the maximum value and the minimum value of the measured specific gravity of the five parts, which is a measure of the uniformity of the quality of the foam, is preferably 0.08 or less, and more preferably 0.06 or less. . When the range exceeds 0.08, it means that the quality of the molded product (hardness, mechanical properties, compression set, etc.) is not constant.

Asker C Hardness Asker C hardness was measured in a 23°C environment according to the "Spring Hardness Test Type C Test Method" described in Appendix 2 of JIS K7312-1996.

Repulsion Resilience Repulsion resilience was measured according to JIS K6255. A sample was prepared in the same manner as the sample used for the compression set (CS) in (2) above, and was measured in an atmosphere of 23°C.

Interlaminar tear strength The interlaminar tear strength was measured at a test temperature of 23° C. using an Intesco 205X testing machine. A sample prepared in the shape of a strip with a width of 25 mm and a thickness of 15 mm was set at a distance of 30 mm between chucks, and peeled off in the thickness direction at a test speed of 50 mm/min. The interlaminar tear strength S (N/mm) was calculated using the following formula.
S=S0/S1
S0: tearing stress (N)
S1: Sample width (mm)

Compression set (CS)
Compression set (CS) was measured according to JIS K6262. The sample used was one in which the foam was cut into a cylinder with a diameter of 30 mm and a thickness of 15 mm or more, and each of the two parallel planes of the cylinder was extracted from the surface of the parallel plane, and the thickness was 10 mm with the skin remaining on one side. there was.

Note that even if the foam to be sampled is a three-dimensional object of various shapes, cut it into a cylinder with a diameter of 30 mm and a thickness of 15 mm or more, extract each of the two parallel planes of the cylinder from the surface of the parallel plane, A sample was prepared with a thickness of 10 mm with the skin left on one side.

A cylindrical dumbbell mold can be used to cut the foam into a cylindrical shape and to cut the foam from parallel plane surfaces. This sample was compressed by 50% and allowed to stand at 50° C. for 6 hours, and was then released from compression and measured 30 minutes later. Compression set (CS) (%) was calculated using the following formula.

CS=(t0-t1)/(t0-t2)×100
t0: Sample original thickness (mm)
t1: Thickness (mm) 30 minutes after removing the sample from the compression device
t2: Spacer thickness (mm)

Heat Shrinkage Rate The heat shrinkage rate was measured after the molded foam was heat treated in a 70°C environment for 60 minutes, taken out in a 23°C environment and 30 minutes later. Thermal shrinkage rate (Sh) (%) was calculated using the following formula.
Sh=s1/s0×100
s0: Vertical length of sample before heat treatment (mm)
s1: Vertical length of sample after heat treatment (mm)

[Example 1]

Production of ethylene/1-butene copolymer (A-1) Using a stainless steel polymerization vessel with an internal volume of 100 L equipped with a stirring blade (stirring rotation speed = 250 rpm), the polymerization temperature was 130°C and the polymerization pressure was 2.5 MPaG. , ethylene and 1-butene were copolymerized continuously. From the side of the polymerization vessel, 22 L of dehydrated hexane, 4.8 kg of ethylene, and 2.0 kg of 1-butene are added every hour, and 100 NL of hydrogen and di(p-tolyl)methylene (cyclopentadienyl) ( A copolymerization reaction was carried out by continuously feeding 0.003 mmol of octamethyloctahydrodibenzofluorenyl)zirconium dichloride, 1.5 mmol of methylaluminoxane in terms of aluminum, and 5 mmol of triisobutylaluminum. The hexane solution of the produced ethylene/1-butene copolymer was passed through the outlet provided on the side wall of the polymerization vessel, and the opening degree of the liquid level control valve was adjusted so as to maintain the amount of solution in the polymerization vessel at 28 L. It was continuously discharged. The hexane solution of the obtained ethylene/1-butene copolymer was introduced into a heater and heated to 180°C, and 80 mL of methanol was added every hour as a catalyst deactivator to stop the polymerization, followed by devolatilization under reduced pressure. By continuously transferring the product to a process and drying it, an ethylene/1-butene copolymer (A-1) was obtained.

The ethylene/1-butene copolymer (A-1) obtained as described above has a density d of 0.905 g/cm ³ , an MFR _2.16 of 0.5 g/10 min, and an MFR ₁₀ of 3.9 g/10 min. , Mw/Mn was 2.1, the amount of vinyl double bonds was 0.049/1000C, the melting point was 94°C, and the yield was 7.0 kg/hour.

Production of ethylene/1-butene copolymer (B-1) Using a stainless steel polymerization vessel with a substantial internal volume of 1 L (stirring rotation speed = 500 rpm) equipped with a stirring blade, at a polymerization temperature of 125°C, in a full liquid state. Copolymerization of ethylene and 1-butene was carried out continuously. Each hour, 1.73 L of hexane, 56 g of ethylene, and 100 g of 1-butene are added to the liquid phase from the side of the polymerization vessel, and 0.4 NL of hydrogen and bis(p-tolyl)methylene (cyclopentadienyl) ( 1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dichloride 0.00015 mmol of methylaluminoxane/toluene solution and 1.0 mmol of triisobutylaluminum were continuously supplied at a rate of 0.075 mmol and triisobutylaluminum at a rate of 1.0 mmol, and the copolymerization reaction was carried out by maintaining the polymerization pressure at 3.8 MPaG. The continuously obtained hexane solution of the ethylene/1-butene copolymer was stored in a hold drum, and 0.2 ml of methanol was added thereto as a catalyst deactivator every hour to stop the polymerization.

The hexane solution of the obtained ethylene/1-butene copolymer was extracted every hour, and the polymer was precipitated from the polymerization solution in 2 L of methanol, and dried under vacuum at 130°C for 10 hours to form an ethylene/1-butene copolymer. Combined product (B-1) was obtained.

The ethylene/1-butene copolymer (B-1) obtained as described above has a density d of 0.861 g/cm ³ , an MFR _2.16 of 0.5 g/10 min, and an MFR ₁₀ of 5.1 g/10 min. , Mw/Mn was 2.0, the amount of vinyl double bonds was 0.020/1000C, and the yield was 49.0 g/hour.

Production of crosslinked foam 5 parts by mass of the ethylene/1-butene copolymer (A-1) obtained above, 20 parts by mass of the ethylene/1-butene copolymer (B-1), ethylene vinyl acetate copolymer ( VA content = 28 wt%) [Product name Evaflex EV270] 75 parts by mass, acrylate derivative masterbatch [Product name ZnRicon50] 0.6 parts by mass, zinc oxide 2.0 parts by mass, stearic acid 0.7 parts by mass, acrylate derivative Masterbatch [trade name IB50] 0.6 parts by mass, titanium oxide 5.0 parts by mass, zinc stearate 1.0 parts by mass, dicumyl peroxide (DCP) 1.0 parts by mass, azodicarbonamide 3.9 parts by mass , and 2 parts by mass of silicone rubber (trade name CF201U, manufactured by Dow Corning) was kneaded with a roll for 10 minutes at a roll surface temperature of 120°C, and then kneaded in a single screw extruder equipped with a twin taper screw. The mixture was pelletized at a temperature below (approximately 130°C) at which the mixture did not start crosslinking or foaming.

The obtained pellets were put into an injection foam molding machine (manufactured by King Steel) to obtain a crosslinked foam. The mold conditions are 100 kg/cm ² , 170°C, 7 minutes, and the injection foaming conditions (injection cylinder conditions) are injection pressure 90 kg/cm ² and cylinder temperature settings: C1/C2/C3/C4 = 80/85. /90/95°C, injection speed: C1/C2/C3/C4=28/26/24/22%. The mold size was 10 mm thick, 180 mm long, and 60 mm wide.

Immediately after molding, the obtained crosslinked foam was annealed at 60°C for 30 minutes, and after 24 hours, specific gravity, compression set, Asker C hardness, impact resilience, interlaminar tear strength, and heat shrinkage were measured according to the above methods. did. The results are also shown in Table 1.

[Example 2]
Production of crosslinked foam, evaluation of physical properties, and evaluation of molding stability
In Example 1, 10 parts by mass of ethylene/1-butene copolymer (A-1), 15 parts by mass of ethylene/1-butene copolymer (B-1), and 4.1 parts by mass of azodicarbonamide. A crosslinked foam was produced and its physical properties were evaluated in the same manner as in Example 1, except for the following. The results are also shown in Table 1.

[Comparative example 1]
Production of ethylene/1-butene copolymer (A'-2)
Copolymerization of ethylene and 1-butene was carried out continuously at a polymerization temperature of 130° C. in a full liquid state using a stainless steel polymerization vessel with a substantial internal volume of 1 L equipped with stirring blades (stirring rotation speed = 500 rpm). . Each hour, 1.82 L of hexane, 56 g of ethylene, and 40 g of 1-butene are added to the liquid phase from the side of the polymerization vessel, and 0.6 NL of hydrogen and bis(p-tolyl)methylene (cyclopentadienyl) ( 1,1,4,4,7,7,10,10-octamethyl-1,2,3,4,7,8,9,10-octahydrodibenz(b,h)-fluorenyl)zirconium dichloride 0.0001 mmol of methylaluminoxane/toluene solution, 0.05 mmol of aluminum equivalent, and 1.0 mmol of triisobutylaluminum were continuously supplied at a rate of 1.0 mmol, and the copolymerization reaction was carried out by maintaining the polymerization pressure at 3.8 MPaG. The continuously obtained hexane solution of the ethylene/1-butene copolymer was stored in a hold drum, and 0.2 ml of methanol was added thereto as a catalyst deactivator every hour to stop the polymerization.

The obtained hexane solution of the ethylene/1-butene copolymer was extracted every hour, and the polymer was precipitated from the polymerization solution in 2 L of methanol, and dried under vacuum at 130°C for 10 hours to form the ethylene/1-butene copolymer. Combined product (A'-2) was obtained.

The ethylene/1-butene copolymer (A'-2) obtained as described above has a density d of 0.905 g/cm ³ , an MFR _2.16 of 1.2 g/10 min, and an MFR ₁₀ of 7.9 g/cm 3 . 10 min, Mw/Mn was 2.0, the amount of vinyl double bonds was 0.020 pieces/1000C, the melting point was 94°C, and the yield was 43.5 g/hour.

Production of crosslinked foam, evaluation of physical properties, and evaluation of molding stability In Example 1, the ethylene/1-butene copolymer (A-1) was replaced with the ethylene/1-butene copolymer (A'-2). Otherwise, a crosslinked foam was produced and its physical properties were evaluated in the same manner as in Example 1. The results are also shown in Table 1.

[Comparative example 2]
Production of crosslinked foam, evaluation of physical properties, and evaluation of molding stability
In Comparative Example 1, 10 parts by mass of ethylene/1-butene copolymer (A'-2), 15 parts by mass of ethylene/1-butene copolymer (B-1), and 3.8 parts by mass of azodicarbonamide. A crosslinked foam was produced and its physical properties were evaluated in the same manner as in Comparative Example 1 except that The results are also shown in Table 1.

[Comparative example 3]
Production of crosslinked foam, evaluation of physical properties, and evaluation of molding stability
Comparative Example 1 except that the ethylene/1-butene copolymer (A'-2) was 0 parts by mass and the ethylene/1-butene copolymer (B-1) was 25 parts by mass. A crosslinked foam was produced and its physical properties were evaluated in the same manner as in Example 1. The results are also shown in Table 1.

架橋発泡体の評価結果および成形安定性評価結果
特定のエチレン・α－オレフィン共重合体を含有する本発明のエチレン系共重合体組成物を用いた実施例１～２は、ビニル基含量の少ないエチレン・α－オレフィン共重合体を用いた比較例１～２や、エチレン・α－オレフィン共重合体を用いていない比較例３と比べ、熱収縮率に優れ、圧縮永久歪みが小さい傾向が認められる。

Crosslinked foam evaluation results and molding stability evaluation results Examples 1 and 2 using the ethylene copolymer composition of the present invention containing a specific ethylene/α-olefin copolymer have a low vinyl group content. Compared to Comparative Examples 1 and 2 that used an ethylene/α-olefin copolymer and Comparative Example 3 that did not use an ethylene/α-olefin copolymer, it was observed that the heat shrinkage rate was excellent and the compression set tended to be small. It will be done.

The ethylene copolymer composition of the present invention is suitable for the production of various molded bodies and foams, and is particularly suitable for the production of crosslinked molded bodies and crosslinked foams, and can be used for conventionally known uses without restriction. I can do it. For example, the ethylene copolymer composition of the present invention, and molded articles, foams, and laminates using the same, can be used for automobile interiors and exteriors, such as automobile interior skin materials, weather strip sponges, body panels, steering wheels, and side shields. Parts; Civil engineering and construction materials such as soil improvement sheets, water supply boards, and noise prevention walls; Industrial parts; Footwear parts such as shoe soles and sandals; Electrical and electronic parts such as wire sheathing materials, connectors, and cap plugs; Golf clubs Sports and leisure goods such as grips, baseball bat grips, swimming fins, and underwater glasses; miscellaneous goods such as gaskets, waterproof cloth, garden hoses, belts, drain sheets, and cosmetic puffs. In particular, it can be suitably used as footwear parts such as shoe soles, shoe midsoles, inner soles, soles, and sandals.

Claims (15)

An ethylene-based copolymer formed by copolymerizing only ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies all of the following requirements (a), (b), (c), and (d). Copolymer (A) and
An ethylene copolymer ( ^B ) An ethylene copolymer composition characterized by comprising;
(a) The vinyl group content per 1000 carbon atoms as determined by ¹ H-NMR is in the range of 0.003 to 0.3.
(b) MFR ₁₀ /MFR _2.16 is in the range of 7 to 20. (However, MFR ₁₀ is the melt flow rate measured at 190℃ and 10kg load according to the method of ASTM D1238, and MFR _2.16 is the melt flow rate measured at 190℃ and 2.16kg load according to the method of ASTM D1238. .)
(c) The density is in the range of 0.875 to 0.910 g/cm ³ .
(d) The melt flow rate (MFR _2.16 ) measured by the method of ASTM D1238 at 190°C and a load of 2.16 kg is in the range of 0.01 to 200 g/10 minutes. The ethylene copolymer (A) has a content of structural units derived from ethylene in the range of 60 to 98 mol%, and a content of structural units derived from α-olefin having 3 to 20 carbon atoms is 2 to 40 mol%. % of the ethylene copolymer composition. The ethylene copolymer composition according to claim 1 or 2, wherein the ethylene copolymer (A) has a melting point in the range of 50 to 120°C. The ethylene copolymer composition according to any one of claims 1 to 3, wherein the ethylene copolymer (A) is an ethylene/1-butene copolymer. The mass ratio [(A)/(B)] of the ethylene copolymer (A) and the ethylene copolymer (B) is in the range of 5/95 to 80/20. The ethylene copolymer composition according to any one of claims 1 to 4. The ethylene copolymer composition according to any one of claims 1 to 5, further comprising an ethylene/polar monomer copolymer (C). The mass ratio [(A)/(C)] of the ethylene copolymer (A) and the ethylene/polar monomer copolymer (C) is in the range of 1/99 to 39/61. The ethylene copolymer composition according to claim 6. The ethylene copolymer composition according to any one of claims 1 to 7, further comprising a blowing agent (D), a crosslinking agent (E), or a combination thereof. The ethylene copolymer composition according to any one of claims 1 to 8, further comprising a crosslinking aid (F). A foam obtained by crosslinking and foaming the ethylene copolymer composition according to claim 8 or 9. A laminate comprising a layer made of the foam according to claim 10 and a layer made of at least one material selected from the group consisting of polyolefin, polyurethane, rubber, leather, and artificial leather. Footwear characterized by using the foam according to claim 10 or the laminate according to claim 11. A footwear component comprising the foam according to claim 10 or the laminate according to claim 11. 14. The footwear component according to claim 13, wherein the footwear component is a midsole, an inner sole, or a sole. A method for producing a foam comprising the step of foaming the ethylene copolymer composition according to any one of claims 1 to 9.