JP2024057981A - 3-methyl-1-butene copolymer, its production method, and 3-methyl-1-butene copolymer composition - Google Patents

Abstract

[Problem] To provide a 3-methyl-1-butene copolymer and a 3-methyl-1-butene copolymer composition that have excellent heat resistance, can suppress thermal degradation during processing, and achieve both toughness and strength, and a method for producing the 3-methyl-1-butene copolymer. [Solution] A 3-methyl-1-butene copolymer that contains a 3-methyl-1-butene copolymer resin, has a melting point of 265.0 to 290.0°C, and has a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1): Y>(-X/16)+42.5 Formula (1) [Selected Figure] None

Description

The present invention relates to a 3-methyl-1-butene copolymer, a method for producing the same, and a 3-methyl-1-butene copolymer composition.

3-Methyl-1-butene polymers are widely known as high-melting polyolefins that can have a melting point of about 305°C. Therefore, 3-methyl-1-butene polymers require high processing temperatures, which may cause the resin to deteriorate during processing. To avoid resin deterioration during processing, a technique is known for lowering the melting point of 3-methyl-1-butene polymers and widening the processing temperature range. For example, efforts have been made to lower the melting point of the polymer by copolymerization (see, for example, Patent Document 1). However, by making 3-methyl-1-butene polymers into copolymers, although the melting point is lowered and the toughness seen in tensile elongation is improved, there is a problem of a decrease in mechanical properties such as tensile strength.

On the other hand, as a method for achieving both toughness and strength in a polymer, for example, a multi-stage polymerization method for obtaining a composition with a varied copolymerization composition is known (for example, Patent Document 2).
Patent Document 2 discloses a composition comprising three types of 3-methyl-1-butene polymers having different heats of fusion for the purpose of achieving excellent heat resistance and extensibility represented by Vicat softening point, and mechanical strength such as impact strength and tear strength, and discloses that the composition is produced by a three-stage polymerization method.
As another method for achieving both toughness and strength in a polymer, for example, multi-stage addition of hydrogen is known (for example, Patent Documents 3 to 5).
Patent Document 3 discloses a polymerization method in which, when homopolymerizing ethylene or copolymerizing ethylene with an α-olefin, a polymerization reaction is carried out in two stages in the presence of hydrogen, in which the amount of hydrogen added is changed in each stage to obtain polymers having different viscosity average molecular weights.
Patent Document 4 discloses a polypropylene having high fluidity, high melting point and high crystallinity. Specifically, Patent Document 4 discloses that the polypropylene preferably comprises a polypropylene component A having high fluidity and high stereoregularity and a polypropylene component B having low fluidity and high stereoregularity, and that the polypropylene component A and the polypropylene component B can be produced by multi-stage polymerization while changing the amount of hydrogen added.
Furthermore, Patent Document 5 discloses a method for producing a composition containing two or more kinds of branched α-olefin polymers having different intrinsic viscosities by a multi-stage polymerization process, in which the amount of added hydrogen is changed in each stage.

Japanese Patent Application Laid-Open No. 61-103910 Japanese Patent Application Laid-Open No. 64-143 Japanese Patent Application Laid-Open No. 56-22304 Japanese Patent Application Laid-Open No. 6-329726 Japanese Patent Application Laid-Open No. 63-20307

The composition made of the 3-methyl-1-butene polymer of Patent Document 2 is excellent in mechanical strength such as stretchability, impact strength, and tear strength, but the melting point is not sufficiently lowered. Moreover, the technology of Patent Document 2 tends to reduce the transparency of the polymer.
Patent Document 3 does not consider polymers using 3-methyl-1-butene as a monomer. Patent Documents 4 and 5 describe that 3-methyl-1-butene can be used as a monomer, but do not specifically disclose examples using this monomer or the effects thereof.
Therefore, the present invention provides a 3-methyl-1-butene copolymer and a 3-methyl-1-butene copolymer composition which have excellent heat resistance, are capable of suppressing thermal degradation during processing, and have both toughness and strength, and a method for producing the 3-methyl-1-butene copolymer.

As a result of intensive research aimed at solving the above problems, the present inventors have conceived of the present invention described below and found that the problems can be solved.
That is, the present invention is as follows.

[1] A 3-methyl-1-butene copolymer containing a 3-methyl-1-butene copolymer resin, having a melting point of 265.0 to 290.0°C, and having a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1):
Y>(-X/16)+42.5 Equation (1)
[2] The 3-methyl-1-butene copolymer resin is a resin obtained by a multi-stage polymerization method,
The multi-stage polymerization method includes a first step and a second step,
In the first step, a 3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec ^-1 measured by a capillograph at 320°C is produced;
The 3-methyl-1-butene copolymer according to the above [1], which is obtained by further polymerizing the 3-methyl-1-butene copolymer resin produced in the first step in the second step.
[3] The 3-methyl-1-butene copolymer resin is a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms, according to the above [1] or [2].
[4] The 3-methyl-1-butene copolymer according to [3] above, wherein the content of structural units derived from the α-olefin in the 3-methyl-1-butene copolymer is more than 0 mol% and not more than 20 mol%.
[5] A method for polymerization comprising: a first step of continuously supplying hydrogen to 3-methyl-1-butene at a hydrogen flow rate of 0.01 to 75 mL/(h·L) per unit volume based on the initial charge volume of the 3-methyl-1-butene; and a second step of continuously supplying hydrogen to 3-methyl-1-butene at a hydrogen flow rate of 50 to 1000 mL/(h·L) per unit volume based on the initial charge volume of the 3-methyl-1-butene used in the first step,
A method for producing a 3-methyl-1-butene copolymer, wherein the hydrogen flow rate in the first step is different from the hydrogen flow rate in the second step.
[6] A 3-methyl-1-butene copolymer composition comprising a 3-methyl-1-butene copolymer resin, having a melting point of 265.0 to 290.0°C, and having a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1):
Y>(-X/16)+42.5 Equation (1)
[7] The 3-methyl-1-butene copolymer composition according to the above item [6], which contains at least one of the above 3-methyl-1-butene copolymer resins having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec-1 measured by capillography at 320°C.
[8] The 3-methyl-1-butene copolymer according to any one of [1] to [4] above, and the 3-methyl-1-butene copolymer composition according to [6] or [7] above. A resin composition comprising at least one selected from the group consisting of the 3-methyl-1-butene copolymer composition.

Furthermore, the following embodiments are also preferred.
[9] The 3-methyl-1-butene copolymer composition according to the above [6] or [7], wherein the 3-methyl-1-butene copolymer resin is a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms.
[10] The 3-methyl-1-butene copolymer composition according to [9] above, wherein the content of the structural unit derived from the α-olefin in the 3-methyl-1-butene copolymer composition is more than 0 mol % and not more than 20 mol %.

The present invention can provide a 3-methyl-1-butene copolymer and a 3-methyl-1-butene copolymer composition that have excellent heat resistance, are capable of suppressing thermal degradation during processing, and have both toughness and strength, as well as a method for producing the 3-methyl-1-butene copolymer.

Hereinafter, the present invention will be described based on an example of an embodiment. However, the embodiment described below is an example for embodying the technical idea of the present invention, and the present invention is not limited to the following description.
In addition, in this specification, preferred embodiments are shown, but a combination of two or more of the individual preferred embodiments is also a preferred embodiment. When there are several numerical ranges for matters shown as numerical ranges, the lower limit value and the upper limit value can be selectively combined to form a preferred embodiment.
In this specification, when a numerical range is stated as "XX to YY", it means "XX or more and YY or less".

The 3-methyl-1-butene copolymer of the present embodiment contains a 3-methyl-1-butene copolymer resin, has a melting point of 265.0 to 290.0°C, and has a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1).
Y>(-X/16)+42.5 Equation (1)
The 3-methyl-1-butene copolymer composition of the present embodiment (hereinafter also referred to as the "copolymer composition") contains a 3-methyl-1-butene copolymer resin, has a melting point of 265.0 to 290.0°C, and has a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1):
Y>(-X/16)+42.5 Equation (1)
The 3-methyl-1-butene copolymer and copolymer composition of the present embodiment can achieve both toughness and strength by satisfying the above formula (1). That is, the 3-methyl-1-butene copolymer and copolymer composition have high mechanical properties such as tensile strength, are useful as molded members, and are expected to have excellent toughness as seen in tensile elongation and excellent impact resistance of molded products. In addition, the 3-methyl-1-butene copolymer and copolymer composition have a melting point in a specific range, and thus have excellent heat resistance while suppressing thermal degradation during processing. That is, the 3-methyl-1-butene copolymer and copolymer composition can be easily molded at a wide range of processing temperatures while having excellent heat resistance, and in addition, it is expected that decomposition gas is suppressed during melt kneading, resulting in excellent moldability.
In this embodiment, the term "3-methyl-1-butene copolymer" refers to a polymer produced by a series of polymerization reactions in the same polymerization reactor, and contains two or more copolymers of 3-methyl-1-butene and unsaturated hydrocarbons. The term "3-methyl-1-butene copolymer composition" refers to a composition obtained by blending two or more copolymers of 3-methyl-1-butene and unsaturated hydrocarbons produced in the respective polymerization reactors. The term "3-methyl-1-butene copolymer resin" (hereinafter also referred to as "copolymer resin") refers to the copolymer of 3-methyl-1-butene and unsaturated hydrocarbons contained in the 3-methyl-1-butene copolymer and the 3-methyl-1-butene copolymer composition.

<3-Methyl-1-butene Copolymer and Copolymer Composition>
[Melting point]
The 3-methyl-1-butene copolymer and the copolymer composition have a melting point of 265.0 to 290.0°C.
When the melting point of the 3-methyl-1-butene copolymer or copolymer composition is less than 265.0° C., the heat resistance becomes insufficient. When the melting point of the 3-methyl-1-butene copolymer or copolymer composition is more than 290.0° C., the processing temperature needs to be increased, and there is a risk of significant thermal degradation during processing.
From the viewpoint of easily obtaining a balance between even better heat resistance and a wide range of processing temperatures, the melting point of the 3-methyl-1-butene copolymer and the copolymer composition is preferably 270.0 to 290.0°C, more preferably 275.0 to 290.0°C.
The melting point can be adjusted by the type and content of monomers other than 3-methyl-1-butene, and the addition and content of crystallinity control additives such as a crystal nucleating agent and a crystal retarder.
The melting point can be measured by the method described in the Examples.

[Formula (1)]
The 3-methyl-1-butene copolymer and the copolymer composition have a breaking elongation X (%) and a yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 that satisfy the following formula (1).
Y>(-X/16)+42.5 Equation (1)
When the 3-methyl-1-butene copolymer and copolymer composition do not satisfy the above formula (1), the balance of mechanical properties of the molded article is poor, and both or either of the strength and impact resistance are insufficient.
The above formula (1) is a formula derived from the balance between toughness and strength of the molded body based on the examples and comparative examples. Specifically, using the numerical values of the breaking elongation and yield elongation obtained in the examples and comparative examples, the horizontal axis represents breaking elongation and the vertical axis represents yield strength, and a straight line and its slope were obtained from a plot that was excellent in both breaking elongation and yield elongation, and formula (1) was obtained.
In addition, in the case of 3-methyl-1-butene copolymers and copolymer compositions, when the melting point is lowered, the toughness is generally improved but the strength tends to decrease. However, the 3-methyl-1-butene copolymer and copolymer composition of the present embodiment can realize an excellent balance between toughness and strength by satisfying formula (1) while having the above-mentioned melting point.

The lower limit of the breaking elongation X of the 3-methyl-1-butene copolymer and the copolymer composition is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more. The upper limit of the breaking elongation X is preferably 200% or less, more preferably 100% or less, even more preferably 50% or less, and even more preferably 35% or less. That is, the breaking elongation X is preferably 5 to 200%.
The breaking elongation X can be adjusted by the amount of hydrogen or comonomer added in the polymerization reaction, the time and timing of addition, the method of addition, and the like.

The yield strength Y of the 3-methyl-1-butene copolymer and the copolymer composition is preferably 35 to 50 MPa, more preferably 40 to 50 MPa.
The yield strength Y can be adjusted by the amounts of hydrogen and comonomers added in the polymerization reaction, the time and timing of their addition, the method of addition, and the like.
The breaking elongation X and the yield strength Y are measured in accordance with JIS K 7161-1:2014, and more specifically, can be measured by the method described in the Examples. In the Examples, when measuring the breaking elongation and the yield strength, additives such as an alkyl radical scavenger and an antioxidant are added to the 3-methyl-1-butene copolymer and the copolymer composition to prepare a test specimen. The 3-methyl-1-butene polymer is poorly soluble in a solvent and has a high melting point, and is therefore susceptible to thermal degradation due to high-temperature processing. Therefore, when preparing a test specimen, the additives are added to prevent the thermal degradation.

[Melt Viscosity]
The 3-methyl-1-butene copolymer and copolymer composition preferably have a melt viscosity of 30 to 300 Pa·s, more preferably 50 to 150 Pa·s, at a shear rate of 1216 sec ^-1 measured by capillograph at 320°C. If the melt viscosity of the 3-methyl-1-butene copolymer and copolymer composition is within the above numerical range, the 3-methyl-1-butene copolymer and copolymer composition have a good balance between moldability and mechanical properties, which is preferable.
In this embodiment, the melt viscosity can be measured by the method described in the Examples. In the Examples, additives such as an alkyl radical scavenger and an antioxidant are added when measuring the melt viscosity of the 3-methyl-1-butene copolymer, the copolymer composition, and the copolymer resin. Since the 3-methyl-1-butene polymer is poorly soluble in a solvent and has a high melting point, there is a risk that the melt viscosity may change due to thermal degradation during the measurement of the melt viscosity. Therefore, in order to measure the original melt viscosity, the 3-methyl-1-butene copolymer, the copolymer composition, and the copolymer resin are thermally stabilized by the additives, thereby preventing the change in the melt viscosity.

[Copolymer resin]
The copolymer resin is a 3-methyl-1-butene copolymer and a copolymer of 3-methyl-1-butene and an unsaturated hydrocarbon contained in the copolymer composition.
The unsaturated hydrocarbon may, for example, be an α-olefin.
From the viewpoint of allowing the physical properties of 3-methyl-1-butene to be suitably exhibited and having good copolymerizability, the copolymer resin is preferably a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms.

The content of structural units derived from an α-olefin in the 3-methyl-1-butene copolymer and the copolymer composition is preferably more than 0 mol % and 20 mol % or less.
From the viewpoint of favorably exerting the physical properties of the α-olefin, the content of the structural unit derived from the α-olefin in the 3-methyl-1-butene copolymer and the copolymer composition is more preferably 0.1 mol % or more, and further preferably 0.5 mol % or more.
In addition, from the viewpoint of suitably maintaining the physical properties of 3-methyl-1-butene, the content of structural units derived from α-olefin in the 3-methyl-1-butene copolymer and the copolymer composition is more preferably 15 mol % or less, and further preferably 10 mol % or less.
The content of the structural unit derived from an α-olefin in the 3-methyl-1-butene copolymer and the copolymer composition can be determined by a Fourier transform infrared spectrophotometer (FT-IR). Specifically, it can be measured by the method described in the examples.

From the viewpoint of optimally exerting the physical properties of 3-methyl-1-butene, the α-olefin having 2 to 20 carbon atoms is preferably an α-olefin having 4 to 16 carbon atoms, and more preferably an α-olefin having 4 to 12 carbon atoms. In addition, the α-olefin having 2 to 20 carbon atoms may be linear or branched.

Examples of α-olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinylcyclohexene, and vinylnorbornane.
The α-olefins having 2 to 20 carbon atoms may be used alone or in combination of two or more kinds.

<Method of producing 3-methyl-1-butene copolymer>
[Multi-stage polymerization method]
The 3-methyl-1-butene copolymer of the present embodiment is a polymer produced by a series of polymerization reactions in the same polymerization reactor, and contains two or more copolymers of 3-methyl-1-butene and unsaturated hydrocarbons, and can be produced, for example, by a multistage polymerization method. The above-mentioned "copolymer of 3-methyl-1-butene and unsaturated hydrocarbon" has the same meaning as the above-mentioned copolymer resin. That is, a polymer (3-methyl-1-butene copolymer) containing two or more copolymer resins can be produced by a series of polymerization reactions carried out in the same polymerization reactor by the multistage polymerization method.
In a preferred example of this embodiment, the copolymer resin is a resin obtained in each step of a multi-stage polymerization method, the multi-stage polymerization method including a first step and a second step, in which a 3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec ⁻¹ measured by capillography at 320° C. is produced in the first step, and the 3-methyl-1-butene copolymer produced in the first step is further polymerized in the second step.
The multi-stage polymerization method is not limited to the two stages of the first and second steps, but may have three or more polymerization steps.

The copolymer resin produced in the first step has a melt viscosity of 100 to 200 Pa·s, which is preferable since it has an excellent balance between mechanical strength and impact resistance.
From the viewpoint of the balance between mechanical strength and impact resistance, the melt viscosity of the copolymer resin produced in the first step is more preferably 120 to 200 Pa·s, and further preferably 120 to 180 Pa·s.
In the second step, the copolymer resin produced in the first step is further polymerized, so that the copolymer resin produced in the second step can be dispersed in the copolymer resin produced in the first step. At this time, by adjusting the supply amount of a molecular weight modifier such as hydrogen in the first step and the second step, 3-methyl-1-butene copolymer resins having different physical properties such as melt viscosity can be produced in each step.
It is difficult to specify the melt viscosity of the copolymer resin produced in the second step alone, because the copolymer resin produced in the second step necessarily contains the copolymer resin produced in the first step.

(Hydrogen flow rate)
In the above multi-stage polymerization method, it is preferable to adjust the amount of hydrogen supplied in the first step and the second step.
That is, the method for producing a 3-methyl-1-butene copolymer of the present embodiment includes a first step in which 3-methyl-1-butene is used and hydrogen is continuously supplied and polymerized at a hydrogen flow rate per unit volume of 0.01 to 75 mL/(h·L) based on the initial charge volume of 3-methyl-1-butene, and a second step in which hydrogen is continuously supplied and polymerized at a hydrogen flow rate per unit volume of 50 to 1000 mL/(h·L) based on the initial charge volume of 3-methyl-1-butene used in the first step, and is characterized in that the hydrogen flow rate in the first step is different from the hydrogen flow rate in the second step.

In the first step, the hydrogen flow rate per unit volume based on the initial charged volume of 3-methyl-1-butene is 0.01 to 75 mL/(h·L), which is preferable because it provides an excellent balance between reactivity and mechanical properties.
From the viewpoint of the balance between reactivity and mechanical properties, the hydrogen flow rate in the first step is more preferably 1 to 75 mL/(h·L), and further preferably 1 to 65 mL/(h·L).
In the second step, the hydrogen flow rate per unit volume based on the initial charge volume of 3-methyl-1-butene used in the first step is 50 to 1000 mL/(h·L), which is preferable because it provides an excellent balance between reactivity and mechanical properties.
From the viewpoint of the balance between reactivity and mechanical properties, the hydrogen flow rate in the second step is more preferably 50 to 500 mL/(h·L), and further preferably 65 to 500 mL/(h·L). From the viewpoint of the balance between reactivity and mechanical properties, the hydrogen flow rate in the second step is more preferably larger than the hydrogen flow rate in the first step.
In the multi-stage polymerization method, the catalyst and polymerization conditions described below can be preferably used.

<Method of producing copolymer composition>
[Method of mixing two or more copolymer resins]
The 3-methyl-1-butene copolymer composition of the present embodiment is a composition obtained by blending two or more types of copolymers of 3-methyl-1-butene and unsaturated hydrocarbons produced in respective polymerization reactors. The above-mentioned "copolymer of 3-methyl-1-butene and unsaturated hydrocarbon" has the same meaning as the above-mentioned copolymer resin. The copolymer composition can be produced, for example, by mixing two or more types of the above-mentioned copolymer resins produced in separate polymerization reactors. The above-mentioned mixing may be, for example, simply mixing powders or pellets of two or more types of copolymer resins, or may be mixed by melt kneading.

In the above mixing method, it is preferable that the two or more copolymer resins have different melt viscosities.
Specifically, the 3-methyl-1-butene copolymer composition of the present embodiment is preferably formulated with at least one 3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec ^- 1 measured by a capillograph at 320°C.
In the mixing method, the melt viscosity of at least one of the two or more copolymer resins is 100 to 200 Pa·s, which is preferable because it provides an excellent balance between mechanical strength and impact resistance. From the viewpoint of the balance between mechanical strength and impact resistance, the melt viscosity of the at least one copolymer resin is more preferably 120 to 200 Pa·s, and even more preferably 120 to 180 Pa·s.

In addition, in the mixing method, among the two or more copolymer resins, the melt viscosity of at least one copolymer resin different from the above-mentioned "3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s" is preferably 10 to 150 Pa·s, more preferably 30 to 150 Pa·s, and even more preferably 30 to 140 Pa·s. The melt viscosity of 10 to 150 Pa·s is preferable because it is easy to achieve excellent processability during molding.

After two or more types of copolymer resins having different melt viscosities are mixed, it is difficult to specify the melt viscosity of each copolymer resin alone, because it is difficult to separate and measure the melt viscosity of each of the two or more copolymer resins after mixing.
In the method of mixing two or more copolymer resins, the catalyst and polymerization conditions described below can be preferably used.

[catalyst]
(Polymerization catalyst)
In both the above-mentioned multi-stage polymerization method and the method of mixing two or more copolymer resins, the polymerization reaction using 3-methyl-1-butene (hereinafter simply referred to as "polymerization reaction") is not particularly limited, and can be carried out using a catalyst containing a compound having a transition metal atom of Group 4 of the periodic table. In particular, the polymerization of 3-methyl-1-butene is preferably carried out in the presence of a well-known catalyst such as a metallocene catalyst or a Ziegler-Natta catalyst.
Specific examples of the transition metal atom of Group 4 of the periodic table used in the catalyst include titanium, zirconium, and hafnium, with titanium being preferred.

The catalyst containing a compound having a Group 4 transition metal atom of the periodic table may be supplied to the polymerization reaction system as a solid, or may be suspended or dissolved in an inert organic solvent (preferably a saturated aliphatic hydrocarbon) and then supplied to the polymerization reaction system.

The catalyst is preferably a supported catalyst supported on a carrier.
A preferred example of the supported catalyst is a magnesium-supported titanium catalyst in which the compound having a Group 4 transition metal atom of the periodic table is titanium chloride and the support is magnesium chloride, which is a so-called Ziegler-Natta catalyst.
Specifically, the solid magnesium-supported titanium catalyst is obtained by contacting a magnesium compound suspended in an inert hydrocarbon solvent with a liquid titanium compound and, if necessary, an electron donor compound having an ester bond or an ether bond. The magnesium-supported titanium catalyst has a titanium atom, a magnesium atom, a halogen atom, and a plurality of ester bonds or ether bonds.

Examples of inert hydrocarbon solvents used in the production of the magnesium-supported titanium catalyst include hexane, decane, and dodecane. Examples of magnesium compounds include anhydrous magnesium chloride, diethoxy magnesium, and methoxy magnesium chloride. Examples of compounds having an ester bond as an electron donor with multiple atoms in between include alkyl benzoate (the alkyl group preferably has 1 to 8 carbon atoms), alkyl p-toluate (the alkyl group preferably has 1 to 8 carbon atoms), alkyl pivalate (the alkyl group preferably has 1 to 8 carbon atoms), dialkyl phthalate (the alkyl group preferably has 1 to 8 carbon atoms), dialkyl malonate (the alkyl group preferably has 1 to 8 carbon atoms), and dialkyl succinate (the alkyl group preferably has 1 to 8 carbon atoms). Examples of compounds having an ether bond as an electron donor with multiple atoms in between include 2-isobutyl-2-isopropyl-1,3-dimethoxypropane and 2-isopentyl-2-isopropyl-1,3-dimethoxypropane.

The molar ratio of halogen atoms and titanium atoms in the magnesium-supported titanium catalyst (halogen atoms/titanium atoms) is usually 2 to 100, preferably 4 to 90. The molar ratio of electron donor compounds having ester bonds or ether bonds and titanium atoms in the magnesium-supported titanium catalyst (electron donor compounds/titanium atoms) is usually 0.01 to 100, preferably 0.2 to 10. The atomic ratio of magnesium atoms and titanium atoms in the magnesium-supported titanium catalyst (magnesium atoms/titanium atoms) is usually 2 to 100, preferably 4 to 50.

When the above polymerization reaction is carried out by a liquid phase polymerization method, it is preferable to use a solid titanium catalyst in an amount of usually 0.001 to 2 millimoles, preferably 0.005 to 1 millimoles, calculated as titanium atoms per 1 L of total liquid volume.

Examples of catalysts containing a compound having a transition metal atom of Group 4 of the periodic table include solid titanium trichloride catalysts described in JP-A-54-107989 and the like; magnesium-supported titanium catalysts described in JP-A-57-63310, JP-A-58-83006, JP-A-3-706, JP-P3476793, JP-P4-218508, JP-P2003-105022 and the like; metallocene catalysts described in WO 2014/050817, WO 01/53369, WO 01/27124, JP-A-3-193796, or JP-P02-41303 and the like; carrier-supported metallocene catalysts described in JP-A-2009-144148 or JP-P2022-37931; non-patent literature Polyolefins Journal, Vol. 4, No. 1, p. 123-136 (2017), or the non-patent literature Macromolecules, Vol. 40, p. 4130-4137 (2007), so-called postmetallocene catalysts having titanium atoms or hafnium atoms are preferably used.

The catalyst may be one produced by referring to the above-mentioned known literature, or may be a commercially available product.
Commercially available solid titanium trichloride catalysts include, for example, "Solvay Catalyst CATA-1" manufactured by Tosoh Finechem Co., Ltd. Commercially available magnesium-supported titanium catalysts include, for example, "THC Series" manufactured by Toho Titanium Co., Ltd. and "PolyMax Series" manufactured by Clariant Co., Ltd. Commercially available metallocene catalysts include, for example, "rac-Dimethylsilylbis(1-indenyl)zirconium dichlorid" manufactured by Strem.

(Co-catalyst component)
In the above polymerization reaction, it is preferable to use a cocatalyst.
The cocatalyst component is preferably an organometallic compound catalyst component, specifically an organoaluminum compound or a hydrolyzed polymer thereof. The organoaluminum compound is represented by, for example, R ^a _n AlX _3-n .

R ^a in R ^a _n AlX _3-n is preferably a hydrocarbon group having 1 to 12 carbon atoms, such as an alkyl group, a cycloalkyl group, or an aryl group.
Specific examples of the hydrocarbon group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, and a tolyl group.
In R ^a _n AlX _3-n , X is preferably a halogen atom or a hydrogen atom, and n is preferably an integer of 1 to 3.

Specific examples of the organoaluminum compound represented by R ^a _n AlX _3-n include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum; dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, and dimethylaluminum bromide; alkylaluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide; alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, and ethylaluminum dibromide; and alkylaluminum hydrides such as diethylaluminum hydride and diisobutylaluminum hydride.
Of the above specific examples, trialkylaluminum such as triethylaluminum and triisobutylaluminum are preferred.

For example, when the catalyst containing a compound having a Group 4 transition metal atom of the periodic table is a magnesium-supported titanium catalyst component, the amount of the cocatalyst component added may be an amount that produces typically 0.1 to 10,000 g, preferably 1 to 5,000 g, of polymer per gram of the magnesium-supported titanium catalyst component, and is typically 0.1 to 1,000 mol, preferably 0.5 to 500 mol, more preferably 1 to 200 mol per mol of titanium atom in the magnesium-supported titanium catalyst component.

[Polymerization reaction]
The polymerization reaction can be carried out by a liquid phase polymerization method such as solution polymerization, suspension polymerization (slurry polymerization), bulk polymerization, or a gas phase polymerization method, or by other known polymerization methods. The polymerization reaction is preferably a suspension polymerization method.

[solvent]
When the polymerization reaction is carried out by a liquid phase polymerization method, a solvent may not be used, or an inert hydrocarbon may be used as the solvent.
Examples of the inert hydrocarbon solvent include saturated hydrocarbons such as pentane, cyclopentane, hexane, cyclohexane, heptane, isoheptane, and isooctane; and aromatic hydrocarbons such as benzene and toluene.
The solvent may be used alone or in combination of two or more kinds.

[Polymerization conditions]
(Polymerization method)
The polymerization reaction can be carried out in any of a batch system, a semi-continuous system, and a continuous system. The polymerization reaction can also be carried out in two or more stages by changing the reaction conditions.
(Polymerization temperature)
The polymerization temperature in the above polymerization reaction is usually 10 to 150° C., and preferably 30 to 120° C. If the polymerization temperature is within the above range, the progress of the polymerization reaction can be promoted while maintaining good catalytic activity, and the productivity can be improved.
(Polymerization Pressure)
The polymerization pressure in the above polymerization reaction is usually from normal pressure to 5 MPaG, preferably from 0.05 to 4 MPaG. If the polymerization pressure is within the above range, devices such as a high pressure-resistant reactor or an exhaust pump are not required, which is economically advantageous.
(Polymerization time)
The polymerization time in the above polymerization reaction is usually 0.1 to 10 hours, preferably 0.5 to 5 hours. If the polymerization time is within the above range, the deterioration of the physical properties of the polymer caused by thermal degradation is suppressed, and it is easy to produce a polymer with good physical properties.
(Termination of Polymerization)
The polymerization reaction may be terminated by removing the monomer by distillation or filtration, or may be terminated by adding any polymerization terminator as necessary. As the polymerization terminator, a compound that reacts with a catalyst containing a compound having a transition metal atom of Group 4 of the periodic table is preferable. Examples of the polymerization terminator include compounds having active protons such as water, alcohol, primary amine, secondary amine, thiol, and Brestedt acid, ether, phosphine, tertiary amine, thioether, carbon dioxide, and oxygen molecules.
The polymerization terminator may be used alone or in combination of two or more kinds.

[Additive]
If necessary, additives may be added to the polymerization reaction system. Examples of the additives include silane compounds such as methyl(cyclohexyl)dimethoxysilane, ester compounds such as ethyl benzoate, ether compounds such as 2,2-alkyl-substituted-1,3-dimethoxypropane, and amine compounds such as 2,2,6,6-tetramethylpiperidine.
The additives may be used alone or in combination of two or more kinds.

[Removal of catalyst components]
After the above-mentioned polymerization reaction, it is preferable to carry out a step of removing the catalyst components contained in the 3-methyl-1-butene copolymer and the copolymer resin used in the copolymer composition. The method for removing the catalyst components is not particularly limited and may be a known method. For example, there is a method in which an alcohol such as isobutanol or 2-propanol is added to the crude 3-methyl-1-butene copolymer and the crude copolymer resin obtained by the above-mentioned polymerization reaction, the mixture is stirred at a temperature of about 10 to 100°C, and the 3-methyl-1-butene copolymer and the copolymer resin are separated, and a method in which an alcohol such as isobutanol or 2-propanol and a mineral acid such as hydrochloric acid or nitric acid are added to the crude 3-methyl-1-butene copolymer and the crude copolymer resin obtained by the above-mentioned polymerization reaction, the mixture is treated at a temperature of about 10 to 100°C, and the 3-methyl-1-butene copolymer and the copolymer resin are separated, and the like.
The above-mentioned catalyst component removal operation may be carried out on the polymer slurry immediately after the polymerization reaction, or may be carried out after removing unreacted monomers and the reaction solvent from the polymer slurry by distillation or filtration, or may be carried out after carrying out the operation of removing soluble components described below.

[Removal of soluble components]
The crude 3-methyl-1-butene copolymer and crude copolymer resin after the above-mentioned polymerization reaction may contain a polymerization component (hereinafter referred to as "soluble component") that is soluble in a heated hydrocarbon solvent (a hydrocarbon compound having 4 to 20 carbon atoms that may have a branched or cyclic structure). Although the details of the soluble component are not clear, the soluble component may be an oligomer component of the 3-methyl-1-butene copolymer resin, a polymer component with low stereoregularity, a polymer component with a low content of structural units derived from 3-methyl-1-butene, and the like. Therefore, when the soluble component is contained in the crude 3-methyl-1-butene copolymer, the method for producing the 3-methyl-1-butene copolymer of this embodiment may include a step of removing the soluble component, or the 3-methyl-1-butene copolymer may be used for various applications without removing the soluble component.
The method for removing the soluble components is not particularly limited and may be a known method. Examples of the soluble component removal procedure include a method in which a hydrocarbon solvent such as heptane is added to the obtained crude 3-methyl-1-butene copolymer and crude copolymer resin, the mixture is stirred at a temperature of about 50 to 100°C, and the solution is then filtered. In addition, since the soluble components dissolve in the unreacted monomers in the same manner as in the above-mentioned hydrocarbon solvent, the soluble components can also be removed by a method in which the polymer slurry obtained by the above-mentioned polymerization reaction is stirred at a temperature of about 50 to 100°C, and the solution is then filtered. These removal procedures may be repeated.
The soluble components may be removed from the polymer slurry immediately after the polymerization reaction, or may be removed from the polymer slurry by distillation or filtration to remove unreacted monomers and reaction solvent.

[Drying of 3-methyl-1-butene copolymer and copolymer resin]
In the method for producing the 3-methyl-1-butene copolymer of the present embodiment, after the above-mentioned first and second steps and various steps carried out as necessary, a step of drying the obtained 3-methyl-1-butene copolymer may be carried out. Similarly, with regard to the copolymer resin used in the copolymer composition, the copolymer resin may be dried after the above-mentioned polymerization reaction and various steps carried out as necessary.
The drying is not particularly limited and may be performed by a known method. For example, drying may be performed by removing volatiles under conditions of normal pressure to 1 mmHg and 20 to 200° C. During drying, the 3-methyl-1-butene copolymer and copolymer resin may be left stationary, may be fluidized by blowing air or an inert gas, or may be fluidized by a mechanical method such as an agitating rotary blade type dryer, a rotary type dryer, a continuous tray type dryer, or a fluidized type dryer.

<Resin Composition>
The resin composition of the present embodiment contains at least one selected from the group consisting of the above-mentioned 3-methyl-1-butene copolymer and the 3-methyl-1-butene copolymer composition.
The above resin composition may contain additives such as alkyl radical scavengers, antioxidants, antacids, light stabilizers, antistatic agents, flame retardants, pigments, polymerization inhibitors, heavy metal deactivators, ultraviolet absorbers, nucleating agents, clarifying agents, lubricants, fluorescent brightening agents, and rust inhibitors as optional components, so long as the effects of the present invention are not impaired.
The optional components may be used alone or in combination of two or more.

[Alkyl radical scavengers]
The term "alkyl radical scavenger" refers to a compound that reacts with an alkyl radical derived from a 3-methyl-1-butene copolymer or a copolymer composition and then has the function of stabilizing the radical, and serves to suppress a chain reaction of main chain scission initiated by the alkyl radical.
The alkyl radical scavenger preferably contains at least one selected from the group consisting of an acrylphenol compound and a benzofuranone compound.
The alkyl radical scavengers may be used alone or in combination of two or more kinds.

Acrylphenol Compounds
The acrylic phenol compound used as the alkyl radical scavenger can be represented, for example, by the following general formula (I).

In formula (I), R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 9 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.
The alkyl group having 1 to 9 carbon atoms may be either linear or branched.
Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n-nonyl group.
^R1 is preferably a hydrogen atom.
^R2 is preferably a hydrogen atom or a methyl group, more preferably a methyl group.
R ³ , R ⁴ , R ⁵ and R ⁶ are each independently preferably an alkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 5 carbon atoms, and even more preferably a 1,1-dimethylpropyl group.

Examples of the acrylic phenol compound represented by general formula (I) include 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2,4-di-t-butyl-6-[1-(3,5-di-t-butyl-2-hydroxyphenyl)ethyl]phenyl acrylate, and 2-t-butyl-6-[(3-t-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenyl acrylate.
As the alkyl radical scavenger, a commercially available product may be used. Examples of the acrylic phenol compound represented by the general formula (I) include products sold under the trade names "Sumilizer (registered trademark) GS" and "Sumilizer (registered trademark) GM" manufactured by Sumitomo Chemical Co., Ltd.

<Benzofurano compounds>
The benzofuranone compound used as the alkyl radical scavenger can be represented, for example, by the following general formula (II).

In formula (II), R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ⁹ and R ¹⁰ each independently represent an alkyl group having 1 to 9 carbon atoms.
Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, and a t-butyl group.
The alkyl group having 1 to 9 carbon atoms may be linear or branched. Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n-nonyl group.
R ⁷ and R ⁸ are each independently preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group.
R ⁹ and R ¹⁰ each independently represent preferably an alkyl group having 1 to 4 carbon atoms, more preferably a t-butyl group.

Examples of the benzofuranone compound represented by the general formula (II) include 5,7-di-t-butyl-3-(3,4-di-methyl-phenyl)-3H-benzofuran-2-one, 5,7-di-t-butyl-3-(3,4-di-propyl-phenyl)-3H-benzofuran-2-one, and 4-t-butyl-2-(5-t-butyl-2-oxo-3H-benzofuran-3-yl)phenyl-3,5-di-t-butyl-4-hydroxybenzoate.
As the alkyl radical scavenger, a commercially available product may be used. Examples of the benzofuranone compound represented by the general formula (II) include "Irganox (registered trademark) HP-136" manufactured by BASF and "Revonox (registered trademark) 501" manufactured by Chitec.

<Amount of ingredients>
The amount of the alkyl radical scavenger to be blended per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is preferably 0.01 to 1.00 part by mass.
If the amount of the alkyl radical scavenger is within the above range, the physical properties can be kept stable during melt kneading. In addition, there is no risk of the alkyl radical scavenger bleeding out or impairing the physical properties required for the resin composition, such as deterioration of hygroscopicity. In addition, there is no risk of decomposition gas being generated during melt molding, resulting in molding defects.

From the viewpoint of making it easier to exert the effect of the alkyl radical scavenger, the amount of the alkyl radical scavenger blended per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is more preferably 0.02 parts by mass or more, and even more preferably 0.05 parts by mass or more.
From the viewpoint of the balance between the effect of the alkyl radical scavenger and economic efficiency, the amount of the alkyl radical scavenger per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is more preferably 0.80 parts by mass or less, and even more preferably 0.70 parts by mass or less.
When two or more types of alkyl radical scavengers are blended, the amount of the alkyl radical scavengers blended means the total amount of the alkyl radical scavengers blended.

[Antioxidant]
From the viewpoint of heat aging resistance, in the melt kneading step, at least one antioxidant selected from the group consisting of a phenol-based antioxidant and a phosphorus-based antioxidant may be further blended and melt kneaded. In addition, in the melt kneading step, melt kneading may be performed without blending an antioxidant.
The antioxidants may be used alone or in combination of two or more.

<Phenol-based antioxidant>
Examples of the phenol-based antioxidant include pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-t-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and octaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]. Decyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, thiodiethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 3,3',3'',5,5',5''-hexa-t-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, ethylene bis (oxyethylene)bis[3-(5-t-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,6-di-t-butyl-4-[4,6-bis(octylthio)-1,3,5-triazin-2-ylamino]phenol, 3,9-bis[2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl]-2, Examples of such compounds include 4,8,10-tetraoxaspiro(5,5)undecane, 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-t-butyl-m-cresol), 6,6'-di-t-butyl-4,4'-butylidene di-m-cresol, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate, and benzenepropionic acid 3,5-bis-(1,1-dimethylethyl)-4-hydroxy-C7-C9 branched alkyl ester.

The phenol-based antioxidant may be a commercially available product, such as the "Adekastab (registered trademark) AO series" manufactured by ADEKA Corporation or the "Irganox (registered trademark) series" manufactured by BASF Japan.

<Phosphorus-based antioxidant>
Examples of phosphorus-based antioxidants include 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene phosphonite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, di-t-butyl-m-cresyl phosphonite, and diethyl[(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl]phosphone. phosphate, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphonite, 3,9-bis(octadecyoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris(2,4-di-t-butylphenyl)phosphite, tris(nonylphenyl)phosphite, tetra-C12-15-alkyl Examples of such phosphite include [propane-2,2-diylbis(4,1-phenylene)]bis(phosphite), 2-ethylhexyldiphenylphosphite, isodecyldiphenylphosphite, trisisodecylphosphite, triphenylphosphite, and 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane.

Phosphorus-based antioxidants may be commercially available products, such as "ADEKA STAB (registered trademark) PEP series" and "ADEKA STAB (registered trademark) HP series" manufactured by ADEKA Corporation, "Irgafos (registered trademark) series" manufactured by BASF Japan, and "HOSTANOX (registered trademark) P-EPQ" manufactured by Clariant.

<Other antioxidants>
In the melt-kneading step, antioxidants other than the phenol-based antioxidant and the phosphorus-based antioxidant may be added as long as the effects of the present invention are not impaired. Examples of antioxidants other than the phenol-based antioxidant and the phosphorus-based antioxidant include sulfur-based antioxidants and amine-based antioxidants.

<Amount of ingredients>
From the viewpoint of more easily exhibiting heat aging resistance, the blending amount of the antioxidant per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is preferably 0.01 part by mass or more, more preferably 0.10 part by mass or more.
From the viewpoint of economy, the blending amount of the antioxidant per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is preferably 1.00 part by mass or less, more preferably 0.80 part by mass or less.
That is, the blending amount of the antioxidant per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition is preferably 0.01 to 1.00 part by mass.
When two or more antioxidants are used, the amount of the antioxidants mentioned above means the total amount of the antioxidants.

<Antacids>
From the viewpoint of suppressing deterioration due to acid components generated from residual metals and the like, it is preferable to further add an antacid agent in the melt-kneading step.
Antacids include barium laurate, calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, zinc oleate, and magnesium 12-hydroxystearate.
The antacids may be used alone or in combination of two or more.

The amount of antacid to be added per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition can be determined appropriately according to the application, and may be, for example, 0.01 to 200 parts by mass.

<filler>
Depending on the application of the 3-methyl-1-butene copolymer or the copolymer composition, a filler may be further blended and melt-kneaded in the melt-kneading step, or a filler may be blended with the resin composition and then melt-kneaded again.
Examples of the filler include fibrous compounds such as glass fiber, alumina fiber, resin fiber, carbon fiber, and cellulose fiber; flat compounds such as mica, talc, montmorillonite, and flat aluminum; spherical compounds such as glass beads, shirasu balloons, and acrylic balloons; needle-shaped compounds such as needle-shaped metal titanate, wollastonite, needle-shaped silica, and tin oxide; powdered metal titanate, finely powdered wood chips, titanium oxide, calcium carbonate, silica, and alumina; and the like. These fillers may be surface-treated with, for example, a silane coupling agent. A compatibilizer may also be used to enhance the dispersibility of the filler.
The fillers may be used alone or in combination of two or more.

The amount of filler to be blended per 100 parts by mass of the 3-methyl-1-butene copolymer or copolymer composition can be determined appropriately according to the application, and may be, for example, 0.01 to 300 parts by mass.

[Melting and kneading conditions]
<Inert atmosphere>
Depending on the application of the 3-methyl-1-butene copolymer or the copolymer composition, in the melt kneading step, melt kneading is performed by injecting an inert gas into the inside of a melt kneader, or by degassing the inside of the melt kneader under reduced pressure.
In order to suppress deterioration of the physical properties of the melt-kneaded 3-methyl-1-butene copolymer or copolymer composition due to oxygen and to maintain good mechanical properties, it is preferable to melt-knead the copolymer or copolymer composition in an inert atmosphere or in a low-oxygen state.
In this specification, the term "low oxygen state" refers to a state in which the oxygen concentration is lower than that before the degassing by depressurizing the inside of the melt kneader. In the "low oxygen state", the oxygen concentration inside the melt kneader is preferably 5% or less, more preferably 2% or less, and even more preferably 1% or less. The oxygen concentration is measured using an oxygen concentration meter such as a diaphragm-type galvanic type.

The method of injecting an inert gas into the melt kneader to melt and knead may be, for example, to inject each component into the melt kneader while injecting an inert gas into the melt kneader to perform melt kneading, or to inject an inert gas into the melt kneader after injecting each component into the melt kneader to perform melt kneading. Also, the inert gas may be continuously injected into the melt kneader during melt kneading.
The method of injecting the inert gas can be carried out depending on the equipment provided in each melt kneader. For example, the inert gas may be injected from a gas supply section such as an inert gas provided in the melt kneader, from a supply section for each component provided in the melt kneader, or from a gas vent vent provided in the melt kneader.
There is no limitation on the injection method as long as the inert gas can be injected into the entire area from the inert gas supply section to the heating section where melting and kneading are performed, and melting and kneading can be performed.
Examples of inert gases include nitrogen gas, helium gas, neon gas, argon gas, krypton gas, and carbon dioxide gas, with nitrogen gas being preferred from the viewpoints of availability and versatility.

The method of degassing the inside of the melt kneader under reduced pressure and melt kneading may be, for example, to feed each component into the melt kneader, and then degass the inside of the melt kneader under reduced pressure and melt kneading. During melt kneading, degassing the inside of the melt kneader under reduced pressure may be performed intermittently or continuously.
The method of degassing the inside of the melt kneader under reduced pressure can be carried out according to the equipment provided in each melt kneader, and may be carried out through a vacuum vent, for example.
There are no limitations on the method of degassing the inside of the melt kneader under reduced pressure, so long as melt kneading can be performed under a low-oxygen condition.
When degassing under reduced pressure, the inside of the melt kneader can be brought into a vacuum state of, for example, 50 kPa or less and 0.1 kPa or more.

The melt kneader may be a single-screw extruder, multi-screw extruder, kneader, Banbury mixer, or the like, which is equipped with equipment capable of melt kneading by injecting an inert gas into the melt kneader, or equipment capable of melt kneading by depressurizing and degassing the inside of the melt kneader.

<Temperature, time, etc.>
In the melt kneading step, the melt kneading is preferably carried out at 300 to 380° C. depending on the application of the 3-methyl-1-butene copolymer or the copolymer composition.
If the melt kneading temperature is 300° C. or higher, the 3-methyl-1-butene copolymer or copolymer composition melts, and the alkyl radical scavenger and additives are well dispersed. If the melt kneading temperature is 380° C. or lower, decomposition of the 3-methyl-1-butene copolymer or copolymer composition and the alkyl radical scavenger and other raw materials can be suppressed.
From the viewpoint of thoroughly dispersing the alkyl radical scavenger and additives throughout the 3-methyl-1-butene copolymer or copolymer composition, the melt kneading temperature is more preferably 310° C. or higher.
From the viewpoint of suppressing significant decomposition of the raw materials, the melt-kneading temperature is more preferably 380° C. or lower, and further preferably 360° C. or lower.

The melt-kneading time can be adjusted depending on the size of the kneading device, etc. For example, it may be 1 to 15 minutes, but is not limited to this numerical range of melt-kneading time. In this embodiment, the "melt-kneading time" refers to the time the mixer is rotating in a batch kneader, and the residence time of the raw materials in the device in the case of a continuous extrusion kneader.

The rotation speed of the mixer during melt kneading may be 80 rpm or more, or 100 rpm or more, and may be 400 rpm or less, or 350 rpm or less.
After the melt-kneading, the melt-kneaded 3-methyl-1-butene copolymer, 3-methyl-1-butene copolymer composition or resin composition is taken out of the melt-kneader and cooled.

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these.

In the examples and comparative examples, measurements or evaluations were carried out by the following methods.
[Melt Viscosity]
100 parts by mass of the 3-methyl-1-butene copolymer resin of the first step in Example 1 and the 3-methyl-1-butene copolymer obtained in the examples and comparative examples were mixed with 0.2 parts by mass of pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], product name "AO-60", manufactured by ADEKA Corporation, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetrakis ... A dry blend was prepared by mixing 0.2 parts by mass of 3,9-diphosphaspiro[5.5]undecane (trade name "PEP-36" manufactured by ADEKA Corporation), 0.1 parts by mass of 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate (trade name "Sumilizer GS" manufactured by Sumitomo Chemical Co., Ltd.), and 0.25 parts by mass of zinc stearate. The melt viscosity (Pa s) was measured using a capillary rheometer ("Capillography 1C" manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of a barrel temperature of 320° C. and a shear rate of 1216 sec ⁻¹ (capillary: inner diameter 1.0 mm × length 10 mm, extrusion rate 10 mm/min).

[Melting point]
The 3-methyl-1-butene copolymers obtained in the examples and comparative examples were heated from 30° C. to 320° C. at a rate of 10° C./min under a nitrogen flow rate (100 mL/min) using a differential scanning calorimeter (TA Instruments, “DSC25”), held at 320° C. for 5 minutes, and then cooled to −70° C. at a rate of 10° C./min. The melting points were evaluated when the copolymers were held at −70° C. for 5 minutes and then heated to 320° C. at a rate of 10° C./min.

[Breaking elongation, yield strength]
(1) Preparation of Test Pieces 100 parts by mass of the 3-methyl-1-butene copolymer obtained in the Examples and Comparative Examples was mixed with 0.2 parts by mass of pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], trade name "AO-60" manufactured by ADEKA Corporation, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, trade name "PEP- A dry blend of 0.2 parts by mass of "Acetone No. 36" manufactured by ADEKA Corporation, 0.1 parts by mass of 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate (trade name "Sumilizer GS") manufactured by Sumitomo Chemical Co., Ltd., and 0.25 parts by mass of zinc stearate was performed, and the mixture was melt-kneaded under a nitrogen atmosphere at 50 rpm and 320° C. using a small kneader (DSMXplore Micro 15 Compounder).
After melt-kneading for 2 minutes, a small test piece (a 1BA-type dumbbell test piece according to JIS 7161-2, Appendix A) was molded using a small injection molding machine (Micro Injection Molding Machine 10 cc, manufactured by DSMXplore) attached to the small kneader under the conditions of an injection pressure of 0.3 MPa, a retention time in the mold of 35 seconds, and a mold temperature of 180°C.
(2) Measurement The prepared dumbbell test pieces were stored at 23°C and 49% humidity for 24 hours or more, and the breaking elongation X (%) and yield strength Y (MPa) were measured at 23°C, 49% humidity, and a tensile speed of 5 mm/min using a universal material testing machine (Instron Corporation, "INSTRON5900R-5666") in accordance with JIS K 7161-1: 2014. The measurement was performed five times, and the average value was used.

[Content of structural units derived from comonomers]
The content ratio of structural units derived from α-olefins (comonomers) other than 3-methyl-1-butene in the 3-methyl-1-butene copolymers obtained in the examples and comparative examples was determined as follows by IR measurement using an FT-IR (manufactured by Ailent Technologies, device name "cary 600 series FTIR spectrometer") as an analytical device by the ATR method.
A calibration curve was prepared from the ratio of the peak area of the deformation vibration at 1,461 cm ⁻¹ originating from the main chain methylene group of the 3-methyl-1-butene homopolymer to the peak area of the deformation vibration at 727 cm ⁻¹ originating from the side chain methylene group of the α-olefin homopolymer, and the addition ratio of each resin. The IR measurement was carried out on the 3-methyl-1-butene copolymers obtained in the examples and comparative examples, and the obtained measured values were inserted into the calibration curve to determine the content ratio of the structural unit originating from an α-olefin other than 3-methyl-1-butene.

Preparation of Titanium Catalyst Component
[Production Example 1]
47.6g (500mmol) of anhydrous magnesium chloride, 250mL of decane and 234mL (1.5mol) of 2-ethylhexyl alcohol were reacted at 130°C for 2 hours to obtain a homogeneous solution. The homogeneous solution thus obtained was cooled to room temperature, and then dropped into 2L (18mol) of titanium tetrachloride maintained at -20°C over 1 hour. After the charging was completed, the temperature of this mixture was raised to 110°C over 2 hours, and when it reached 110°C, 42.4mL (160mmol) of dibutyl phthalate was added, and the mixture was maintained at the same temperature for 2 hours under stirring. After the reaction for 2 hours was completed, the mixture was left to stand and the supernatant was removed. Decane and hexane were added thereto, and the solid components were washed three times, then resuspended in 2L of titanium tetrachloride, and the mixture was again heated and reacted at 110°C for 2 hours. After the reaction was completed, the mixture was left to stand again using decane and hexane, and the supernatant was repeatedly removed, and the mixture was thoroughly washed until no free titanium compounds were detected in the washings. The resulting suspension was dried under reduced pressure at room temperature for 6 hours to obtain a dried titanium catalyst component having a composition of 4.0 mass% titanium atoms, 56.0 mass% chlorine atoms, 17.0 mass% magnesium atoms, and 11.0 mass% ethyl benzoate.

Synthesis of 3-methyl-1-butene copolymer
[Example 1]
A 20 L stainless steel autoclave was charged with 8.0 kg of 3-methyl-1-butene, 0.6 kg of 1-decene, 50 g of triethylaluminum diluted with hexane to a concentration of 1 mol/L, and 4 g of the titanium catalyst component produced in Production Example 1, and a polymerization reaction was carried out for 2 hours while continuously supplying hydrogen at a rate of 10 mL/min at 70° C. Here, a portion of the polymerization slurry was withdrawn, and the viscosity of the copolymer resin excluding the solvent-soluble polymer produced at this stage was measured, resulting in a melt viscosity of 152 Pa·s. Thereafter, the hydrogen flow rate was changed to a rate of 40 mL/min, and polymerization was continued.
After changing the hydrogen flow rate, 200 g of isoamyl alcohol was injected after 2 hours to stop the reaction and drive out excess unreacted monomers. Then, 2 kg of normal heptane was introduced, and the mixture was stirred at 60°C for 30 minutes, after which the solids were filtered off with a pressure filter. This operation was repeated twice, and the solvent was changed from 2 kg of normal heptane to 3 kg of 2-propanol, and the same operation was repeated twice. 7.7 kg of the crude 3-methyl-1-butene copolymer obtained during the process was placed in a 50 L container equipped with a stirrer, and then 8 kg of 1 mol/L hydrochloric acid and 16 kg of 2-propanol were added and stirred for 1 hour. This suspension was filtered off by vacuum filtration and washed with 10 kg of 2-propanol. This crude 3-methyl-1-butene copolymer was placed in a 50 L container equipped with a stirrer, and then 20 kg of 2-propanol was added and stirred for 1 hour. This suspension was filtered off by vacuum filtration and washed with 10 kg of 2-propanol. The resulting washed 3-methyl-1-butene copolymer was dried under reduced pressure at 80° C. for 2 days to obtain 3.2 kg of a 3-methyl-1-butene copolymer.
The melting point of the obtained 3-methyl-1-butene copolymer was 286.7°C, and the melt viscosity was 133 Pa·s. The content of structural units derived from the comonomer 1-decene was 0.8 mol%. In addition, the breaking elongation and yield strength were measured by the above-mentioned methods. The results are shown in Table 1.
The unit of hydrogen flow rate "mL/min" in the first and second steps is converted into a hydrogen flow rate per unit volume "mL/(h·L)" based on the initial charged volume of 3-methyl-1-butene based on the following formula (A), and the converted values are shown in Table 1. The same applies to Comparative Examples 1 and 2.
b = a x 60 / V0 Formula (A)
In the above formula (A), a represents the hydrogen flow rate (mL/min), V0 represents the initial charged volume of 3-methyl-1-butene (L), and b represents the hydrogen flow rate per unit volume (mL/(h·L)).

[Comparative Example 1]
A 3-methyl-1-butene copolymer was synthesized in the same manner as in Example 1, except that hydrogen was continuously supplied at a flow rate of 40 mL/min for 4 hours.
The melting point of the obtained 3-methyl-1-butene copolymer was 290.1°C and the melt viscosity was 74 Pa·s. The content of structural units derived from the comonomer 1-decene was 0.5 mol%. The breaking elongation and yield strength were measured by the above-mentioned methods. The results are shown in Table 1.

[Comparative Example 2]
A 3-methyl-1-butene copolymer was synthesized in the same manner as in Example 1, except that hydrogen was continuously supplied at a flow rate of 20 mL/min for 4 hours.
The melting point of the obtained 3-methyl-1-butene copolymer was 289.4°C, and the melt viscosity was 56 Pa·s. The content of structural units derived from the comonomer 1-decene was 0.6 mol%. In addition, the breaking elongation and yield strength were measured by the above-mentioned methods. The results are shown in Table 1.

From Table 1, it can be seen that the 3-methyl-1-butene copolymer obtained in the examples satisfies the formula (1) Y>(-X/16)+42.5 while significantly lowering the melting point, and has an excellent balance between the breaking elongation and the yield strength. Therefore, it can be seen that the 3-methyl-1-butene copolymer of this embodiment has excellent heat resistance while suppressing thermal degradation during processing, and achieves both toughness and strength.

Claims (8)

Contains a 3-methyl-1-butene copolymer resin,
The melting point is 265.0 to 290.0°C,
The breaking elongation X (%) and yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 satisfy the following formula (1):
3-Methyl-1-butene copolymer.
Y>(-X/16)+42.5 Equation (1) The 3-methyl-1-butene copolymer resin is a resin obtained by a multi-stage polymerization method,
The multi-stage polymerization method includes a first step and a second step,
In the first step, a 3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec ^-1 measured by a capillograph at 320°C is produced;
In the second step, the 3-methyl-1-butene copolymer resin produced in the first step is further polymerized.
The 3-methyl-1-butene copolymer according to claim 1. The 3-methyl-1-butene copolymer according to claim 1 or 2, wherein the 3-methyl-1-butene copolymer resin is a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms. The 3-methyl-1-butene copolymer according to claim 3, wherein the content of structural units derived from the α-olefin in the 3-methyl-1-butene copolymer is more than 0 mol% and not more than 20 mol%. The method includes a first step of polymerizing 3-methyl-1-butene by continuously supplying hydrogen at a hydrogen flow rate of 0.01 to 75 mL/(h·L) per unit volume based on the initial charge volume of the 3-methyl-1-butene, and a second step of polymerizing 3-methyl-1-butene by continuously supplying hydrogen at a hydrogen flow rate of 50 to 1000 mL/(h·L) per unit volume based on the initial charge volume of the 3-methyl-1-butene used in the first step,
A method for producing a 3-methyl-1-butene copolymer, wherein the hydrogen flow rate in the first step is different from the hydrogen flow rate in the second step. Contains a 3-methyl-1-butene copolymer resin,
The melting point is 265.0 to 290.0°C,
A 3-methyl-1-butene copolymer composition, in which the breaking elongation X (%) and the yield strength Y (MPa) measured in accordance with JIS K 7161-1:2014 satisfy the following formula (1):
Y>(-X/16)+42.5 Equation (1) The 3-methyl-1-butene copolymer composition according to claim 6, which contains at least one 3-methyl-1-butene copolymer resin having a melt viscosity of 100 to 200 Pa·s at a shear rate of 1216 sec ^-1 measured by capillograph at 320°C. A resin composition comprising at least one selected from the group consisting of the 3-methyl-1-butene copolymer according to any one of claims 1 to 4 and the 3-methyl-1-butene copolymer composition according to claim 6 or claim 7.