WO2024080319A1

WO2024080319A1 - 3-methyl-1-butene, and production method of 3-methyl-1-butene polymer

Info

Publication number: WO2024080319A1
Application number: PCT/JP2023/036951
Authority: WO
Inventors: 裕輔村田; 直行片山; 翼稲田; 佑樹松原; 悠佐藤
Original assignee: 株式会社クラレ
Priority date: 2022-10-13
Filing date: 2023-10-12
Publication date: 2024-04-18

Abstract

3-Methyl-1-butene that has a purity determined by gas chromatography of 99.5000-99.9940% and contains 0.0070-0.1700% of 2-methyl-1-butene as an impurity.

Description

Method for producing 3-methyl-1-butene and 3-methyl-1-butene polymer

The present invention relates to a method for producing 3-methyl-1-butene and 3-methyl-1-butene polymers.

3-Methyl-1-butene polymers are widely known as high melting point polyolefins.
It is known that 3-methyl-1-butene has a branched structure and therefore has a lower polymerization activity than α-olefins having a linear structure such as propylene, and there is a problem that a large amount of catalyst is required for the production of a 3-methyl-1-butene polymer. In order to address this problem, for example, catalysts for increasing the activity of polymerization have been studied (for example, see Patent Document 1).

On the other hand, 3-methyl-1-butene is produced by the dehydration reaction of 3-methyl-1-butanol (isoamyl alcohol), usually producing 2-methyl-1-butene and 2-methyl-2-butene as by-products (see, for example, Patent Document 2).
It is also known that the by-produced 2-methyl-1-butene and 2-methyl-2-butene can be purified and removed by distillation (see, for example, Patent Documents 3 and 4).
Furthermore, Patent Document 3 describes that high purity 3-methyl-1-butene is suitable for using 3-methyl-1-butene as a comonomer, and that "if the water content therein exceeds 50 ppm, the catalyst used in the polymerization, for example a metallocene catalyst or a Ziegler-Natta catalyst, is damaged by hydrolysis," and that "preferably, 3-methyl-1-butene is more than 98%, more preferably more than 99.0%, and particularly preferably more than 99.5%. In addition, Patent Document 4 describes that "a mixture in which the mass proportion of 3-methylbut-1-ene is at least 90 mass% and the mass proportion of 2-methylbut-1-ene, 2,2-dimethylprop-1-ene and/or 3-methylbut-2-ene is less than 10 mass%" can be used as a monomer or comonomer.

Japanese Patent Application Laid-Open No. 05-194650 International Publication No. 2005/080302 JP 2012-528097 A US Patent Application Publication No. 2009/0163687

As described above, in Patent Document 1, catalysts are examined to increase the polymerization activity, but the purity of 3-methyl-1-butene is not examined.
As described in Patent Documents 3 and 4, from the viewpoint of polymerization activity, the higher the purity of 3-methyl-1-butene, the more advantageous it is. On the other hand, for example, repeated distillation purification, setting harsh purification conditions, or using a special purification device in order to increase the purity of 3-methyl-1-butene is not necessarily advantageous from the viewpoint of economy. Patent Document 3 does not describe the allowable amount of 2-methyl-1-butene to maintain the high polymerization activity and moldability of 3-methyl-1-butene. In addition, Patent Document 4 describes that the mass ratio of 2-methylbut-1-ene, 2,2-dimethylprop-1-ene, and/or 3-methylbut-2-ene in the mixture is preferably 1 mass% or less, more preferably 0.001 to 1 mass%, but does not describe the balance between the high polymerization activity of 3-methyl-1-butene, moldability, and economy.

The present invention provides 3-methyl-1-butene that can achieve both high polymerization activity, moldability, and economic efficiency, and a method for producing 3-methyl-1-butene polymers using the same.

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

[1] 3-methyl-1-butene having a purity of 99.5000 to 99.9940% as determined by gas chromatography and containing 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity.
[2] A process for polymerizing 3-methyl-1-butene, wherein the 3-methyl-1-butene has a purity of 99.5000 to 99.9940% as determined by gas chromatography, and the 3-methyl-1-butene contains 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity.
A method for producing a 3-methyl-1-butene polymer.
[3] The method for producing a 3-methyl-1-butene polymer according to the above [2], wherein the polymerization is carried out in the presence of a catalyst containing a compound having a transition metal atom of Group 4 of the periodic table.
[4] The method for producing a 3-methyl-1-butene polymer according to the above [3], wherein the catalyst is supported on a carrier.
[5] A resin composition comprising a 3-methyl-1-butene polymer produced by the method for producing a 3-methyl-1-butene polymer according to any one of [2] to [4] above.

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".
In this specification, the term "polymerization activity" means the activity of a catalyst that directly or indirectly promotes the polymerization reaction of 3-methyl-1-butene to produce a 3-methyl-1-butene polymer. The polymerization activity is indicated by the mass of a polymer produced by a polymerization reaction relative to the mass of the catalyst used, and is specifically calculated by the method described in the Examples.
In this specification, the term "liquid" refers to a state in which the material has fluidity in an environment of 1 atmospheric pressure and 25° C. The term "solid" refers to a state in which the material does not have fluidity in an environment of 1 atmospheric pressure and 25° C.

The 3-methyl-1-butene of this embodiment is characterized in that the purity determined by gas chromatography is 99.5000 to 99.9940% and that it contains 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity.
Here, the purity "99.5000 to 99.9940%" is the ratio of the peak area of 3-methyl-1-butene to the sum of the peak areas of all compounds (100%) when 3-methyl-1-butene containing impurities is measured by gas chromatography. Similarly, "0.0070 to 0.1700%" is the ratio of the peak area of 2-methyl-1-butene to the sum of the peak areas (100%) when 3-methyl-1-butene containing impurities is measured by gas chromatography. More specifically, it is determined by the method described in the Examples. As described in detail in the Examples, the purity is the peak area % of gas chromatography, and is simply expressed as "%" in this specification. When 3-methyl-1-butene is, for example, 0.0070%, the purity of 3-methyl-1-butene is naturally 99.9930% or less.
Here, in the measurement by gas chromatography, as exemplified in the examples described later, the detection sensitivity of 3-methyl-1-butene and 2-methyl-1-butene is the same. The detection sensitivity of 2-methyl-2-butene, and the detection sensitivity of 3-methyl-1-butene and 2-methyl-1-butene are also the same. Thus, in this embodiment, the peak area intensity ratio of 3-methyl-1-butene to 2-methyl-1-butene determined by gas chromatography is in the range of 99.9940:0.0070 to 99.5000 to 0.1700. Thus, a composition (e.g., a solution) containing 3-methyl-1-butene that satisfies this range of peak area intensity ratio is also one aspect of this embodiment.

Although the 3-methyl-1-butene of the present embodiment contains 2-methyl-1-butene as an impurity in the above-mentioned numerical range, the polymerization activity retention rate is 90% or more, and both high polymerization activity and economic efficiency can be achieved.
In addition, the 3-methyl-1-butene of the present embodiment contains 2-methyl-1-butene as an impurity in the above numerical range, so that the 3-methyl-1-butene polymer is more likely to have fluidity suitable for molding, and moldability, particularly injection moldability, is more likely to be obtained. Moldability and fluidity can be evaluated, for example, by measuring the melt flow rate according to the method described in the Examples section below. The 3-methyl-1-butene of the present embodiment has a melt flow rate measured by the above method of preferably 1.0 g/10 min or more, more preferably 1.1 g/10 min or more, even more preferably 1.2 g/10 min or more, and even more preferably 1.3 g/10 min or more. The upper limit of such melt flow rate is not particularly limited, but is, for example, 300 g/10 min or less, preferably 100 g/10 min or less, more preferably 50 g/10 min or less, and even more preferably 10 g/10 min or less.
In addition, if the amount of 2-methyl-1-butene is within the above range, an excessive increase in the melt flow rate, which is an index of molecular weight, can be suppressed.
Therefore, the 3-methyl-1-butene polymer obtained by polymerizing the above-mentioned 3-methyl-1-butene is likely to have a flowability suitable for molding, and is expected to have excellent retention of mechanical properties due to retention of molecular weight.
In addition, the 3-methyl-1-butene of the present embodiment contains 2-methyl-1-butene as an impurity as described above, but in other words, the present embodiment can be said to be a mixture containing 3-methyl-1-butene and 2-methyl-1-butene. Preferably, the 3-methyl-1-butene of the present embodiment does not contain isobutene, 3-methyl-1-butanol, and di-(3-methylbutyl)ether, or the amounts of these are below the detection limit.

<3-Methyl-1-butene>
[Purity of 3-methyl-1-butene]
The purity of 3-methyl-1-butene in this embodiment is 99.5000 to 99.9940%. If the purity of 3-methyl-1-butene is less than 99.5000%, the polymerization activity decreases, and therefore, it is not economical to produce a 3-methyl-1-butene polymer. If the purity of 3-methyl-1-butene exceeds 99.9940, the reflux ratio in the distillation step of crude 3-methyl-1-butene becomes excessive, and therefore, it is not economical to produce 3-methyl-1-butene. If the purity of 3-methyl-1-butene is 99.9940 or less, it is possible to suppress a decrease in the fluidity (melt flow rate) of the 3-methyl-1-butene polymer, and therefore, it is possible to maintain good injection moldability in particular.
The purity of 3-methyl-1-butene is preferably 99.6000 to 99.9940%, more preferably 99.7000 to 99.9940%, even more preferably 99.7000 to 99.9500%, and still more preferably 99.8000 to 99.9500%.

[impurities]
The 3-methyl-1-butene of this embodiment contains 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity. If the content of 2-methyl-1-butene is less than 0.0070%, the reflux ratio in the distillation step of crude 3-methyl-1-butene becomes excessive, so that 3-methyl-1-butene cannot be produced economically. In addition, the fluidity (melt flow rate) of the 3-methyl-1-butene polymer is too low, and moldability, particularly injection moldability, may be impaired. If the content of 2-methyl-1-butene exceeds 0.1700%, the polymerization reaction is inhibited, so that the amount of catalyst used is increased, and the polymerization activity is reduced, which is not economical. In addition, the molecular weight of the polymer is reduced, so that mechanical properties may also be reduced.
The content of 2-methyl-1-butene in 3-methyl-1-butene (hereinafter sometimes referred to as "contamination amount") is preferably 0.0200 to 0.1600%, more preferably 0.0400 to 0.1500%.

3-methyl-1-butene may contain 2-methyl-2-butene as an impurity. The content of 2-methyl-2-butene in 3-methyl-1-butene is preferably 0.0000 to 0.2000%, more preferably 0.0010 to 0.1500%. If the content of 2-methyl-2-butene is 0.0000 to 0.2000%, the polymerization reaction proceeds well, the amount of catalyst used can be avoided to be excessive, and the polymerization activity does not decrease, making it economical. In addition, if the lower limit of the content of 2-methyl-2-butene is 0.0010% or more, there is no risk of the reflux ratio in the distillation process of crude 3-methyl-1-butene becoming excessive, so this is more preferable.

The influence of the presence of the above impurities on the polymerization reaction of 3-methyl-1-butene is presumed to be as follows.
In the polymerization reaction using 3-methyl-1-butene in this embodiment, coordination polymerization can be carried out, and in this polymerization reaction, a main chain extension reaction proceeds. However, the impurities 2-methyl-1-butene and 2-methyl-2-butene have an inhibitory effect on the polymerization reaction. Compared to linear α-olefins such as 1-butene, 3-methyl-1-butene, which has a bulky branched alkyl group, has a slow main chain extension reaction, so the inhibitory effect cannot be ignored, and even a small amount of the impurities can lead to a decrease in polymerization activity and also cause a decrease in molecular weight, i.e., a decrease in viscosity.
On the other hand, since the effect of molecular weight reduction (viscosity reduction) is greater than the decrease in polymerization activity, the favorable effect of imparting favorable resin properties such as appropriate fluidity and the favorable economic effect of suppressing the decrease in distillation load are considered to be greater than the adverse economic effect of the increase in catalyst usage caused by the inclusion of the above impurities. Therefore, it is advantageous to mix the above impurities in a specific amount.
Therefore, the above impurities and their amounts are one of the factors that affect the balance between polymerization activity, moldability, economic efficiency, and resin physical properties.

[Production method of crude 3-methyl-1-butene]
An example of a method for producing crude 3-methyl-1-butene is a method for obtaining the crude 3-methyl-1-butene by dehydrating 3-methyl-1-butanol. The dehydration reaction of 3-methyl-1-butanol can be carried out by a method known as a dehydration reaction of a primary alcohol, and a method using an acidic substance as a catalyst is preferred.
The acidic substance used as a catalyst in the dehydration reaction of 3-methyl-1-butanol is not particularly limited, and examples thereof include inorganic acids or salts thereof, such as hydrochloric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, sodium hydrogen sulfate, potassium hydrogen sulfate, potassium dihydrogen phosphate, sodium hydrogen sulfite, and potassium hydrogen sulfite; sulfonic acids, such as methanesulfonic acid, benzenesulfonic acid, and toluenesulfonic acid; carboxylic acids, such as acetic acid, propionic acid, benzoic acid, and terephthalic acid; heteropolyacids, such as phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, and silicomolybdic acid; solid acids, such as silica, γ-alumina, silica-alumina, Al ₂ O ₃ —Cr ₂ O ₃ , Al ₂ O ₃ —ZrO ₂ , Al ₂ O ₃ —TiO ₂ , titania, silica-titania, and niobium oxide; and acidic ion exchange resins, such as sulfonic acid-based ion exchange resins and carboxylic acid-based ion exchange resins. These acidic substances may be used alone or in combination of two or more.

The above inorganic acids or salts thereof, sulfonic acids, carboxylic acids, heteropolyacids, etc. may be used by being adsorbed and supported on activated carbon, alumina, silica, etc. The solid acids may be modified in order to control the reactivity.
Among these, preferred are alumina-based acidic substances such as γ-alumina, silica-alumina, Al ₂ O ₃ —Cr ₂ O ₃ , Al ₂ O ₃ —ZrO ₂ , and Al ₂ O ₃ —TiO _2. The alumina-based acidic substance may further contain an alkali metal such as lithium or potassium, an alkaline earth metal such as magnesium or barium, or a rare earth metal such as lanthanum.
When the acidic substance is in a solid state, there is no particular limitation on its shape and size, and any shape and size, such as powder, granules, pellets, or cylinders, can be used depending on the shape or size of the reactor.
Specific examples of γ-alumina include those manufactured by JGC Catalysts and Chemicals under the product names N611, N612, N613, and E30, and those manufactured by Mizusawa Industrial Chemicals under the product name Neobead GB.

The embodiment of the dehydration reaction of 3-methyl-1-butanol is not particularly limited, and the reaction can be carried out in a batch or continuous manner. From the viewpoints of ease of operation, productivity, etc., a continuous reaction method using a solid (preferably alumina-based) acidic substance and a normal fixed bed reaction apparatus such as a single-tube or multi-tube type is preferred.
The reaction temperature for the dehydration reaction of 3-methyl-1-butanol is not particularly limited, but in the case of a continuous reaction using a fixed bed reactor, the reaction temperature is preferably in the range of 150 to 350° C., more preferably in the range of 200 to 320° C., so that the reaction is usually carried out under gas phase conditions. The reaction pressure is also not particularly limited, but is usually preferably in the range of 0.003 to 0.5 MPaG, more preferably in the range of 0.03 to 0.3 MPaG.
In the case of a continuous reaction using a fixed-bed reactor, the supply rate of 3-methyl-1-butanol may vary depending on the packed volume of a solid (preferably alumina-based) acidic substance, the reaction temperature, the reaction pressure, etc., but is usually preferably in the range of 0.1 to 10,000 hr ⁻¹ , more preferably 10 to 3,000 hr ⁻¹ , in terms of the gas hourly space velocity (GHSV) of the vaporized gas of 3-methyl-1-butanol.
In order to dilute 3-methyl-1-butanol, a solvent that does not adversely affect the reaction may be used in the presence of the solvent. Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, and cyclooctane. When the reaction is carried out in a gas phase, an inert gas such as nitrogen or argon may be supplied to a fixed bed reactor together with 3-methyl-1-butanol to dilute the reaction.

[Method for purifying crude 3-methyl-1-butene]
The reaction mixture containing 3-methyl-1-butene obtained by the above-mentioned dehydration reaction of 3-methyl-1-butanol can be purified by a method such as distillation or extraction that is usually used for purifying organic compounds.
In the dehydration reaction of 3-methyl-1-butanol, water is by-produced in an amount approximately equimolar to the obtained product. Most of the by-produced water is separated into layers from the crude 3-methyl-1-butene, and is therefore preferably removed by liquid separation. During liquid separation, the aqueous layer may contain a small amount of organic components, mainly 3-methyl-1-butene. Therefore, the organic components present in the aqueous layer may be recovered by distillation or the like.
The crude 3-methyl-1-butene obtained by removing the water layer from the reaction mixture containing 3-methyl-1-butene contains a small amount of water. If the water content exceeds 50 ppm by mass, the catalyst containing a compound having a transition metal atom of Group 4 of the periodic table used in the polymerization described below will be damaged by hydrolysis, so it is preferable to remove the water contained in the crude 3-methyl-1-butene in a small amount. The removal of the water contained in the small amount can be achieved by a typical method for removing water in organic compounds, such as a chemical removal method in which the crude 3-methyl-1-butene is brought into contact with a chemical substance that reacts with water, such as metallic sodium or sodium hydride, a physical removal method in which the crude 3-methyl-1-butene is brought into contact with a porous substance that selectively adsorbs water, such as molecular sieves, alumina, or zeolite, or a mechanical removal method using a distillation column or a permeation membrane device. From the viewpoint of ease of operation and economic efficiency, the physical removal method and the mechanical removal method are preferred, and the physical removal method using molecular sieves is particularly preferred.

The crude 3-methyl-1-butene from which the above-mentioned trace amounts of water have been removed may also contain so-called low boilers. As used herein, "low boilers" refers to a group of components of a liquid substance mixture, each of which has a boiling point at a lower temperature than the boiling point of 3-methyl-1-butene or a vapor pressure higher than the vapor pressure of 3-methyl-1-butene.
Low boilers are, for example, isobutene, mostly residues from the production of 3-methyl-1-butanol.

The crude 3-methyl-1-butene obtained by removing the above-mentioned trace amounts of water may also contain so-called high boilers. As used herein, "high boilers" refers to a group of components of a liquid substance mixture, each of which has a boiling point at a higher temperature than the boiling point of 3-methyl-1-butene or a vapor pressure lower than the vapor pressure of 3-methyl-1-butene.
Examples of high boiling points include 2-methyl-1-butene and 2-methyl-2-butene produced by isomerization of 3-methyl-1-butene, 3-methyl-1-butanol that did not react during dehydration of 3-methyl-1-butanol to 3-methyl-1-butene, and di-(3-methylbutyl) ether that is generated during dehydration.

The low boiling point and high boiling point substances can be removed by a method generally used for refining organic compounds, such as distillation, extraction, etc. From the viewpoints of operational simplicity and economic efficiency, purification by distillation is preferred.
The distillation column used for purifying crude 3-methyl-1-butene usually has 20 to 120 theoretical plates, preferably 40 to 100 theoretical plates. The crude 3-methyl-1-butene is usually fed to the middle part of the column.
The reflux ratio is preferably between 0.5 and 4.0, more preferably between 1.2 and 3.0, depending on the number of columns to be realized, the composition of the column feed, and the required purity of the top product and bottom product. If the reflux ratio is 0.5 to 4.0, the crude 3-methyl-1-butene can be purified well. In particular, if the reflux ratio is 1.2 or more, 3-methyl-1-butene with the required purity in the polymerization step can be more easily obtained. If the reflux ratio is 3.0 or less, the energy required for coagulation and re-evaporation of the distilled 3-methyl-1-butene can be suppressed, and the pump for refluxing the distillation column is not overloaded, which is more economical. In addition, since the reflux ratio is 4.0 or less, the decrease in the fluidity (melt flow rate) of the 3-methyl-1-butene polymer can be suppressed, and therefore, the injection moldability can be particularly maintained good.
The operating pressure of the column is preferably 0.1 to 2.0 MPa (absolute pressure), more preferably 0.1 to 1.0 MPa (absolute pressure), and further preferably 0.12 to 0.5 MPa (absolute pressure). When the operating pressure of the column is 0.1 to 2.0 MPa, the crude 3-methyl-1-butene can be purified well. In particular, when the operating pressure of the column is 0.12 MPa or more, there is no risk of the boiling point of the distillate becoming too low, and 3-methyl-1-butene can be sufficiently coagulated. When the operating pressure is 0.5 MPa or less, an expensive distillation column with high pressure resistance is not required, which is more economical.

Distillation columns used in the purification of crude 3-methyl-1-butene may be equipped with internals consisting of, for example, trays, rotating internals, random packing and/or structured packing.
Examples of trays include trays having orifices or slits in the tray plate; trays having a neck or chimney that are covered with a bubble cap, hood or shroud; trays having orifices in the tray plate that are covered with a movable valve; trays with special structures; and the like.
In columns with rotating internals, the reflux can be sprayed, for example, by means of a rotating funnel or spread as a film on the heated tube walls by means of a rotor.
An example of an internal structure made of random packing is a column having a random stack of various packings. The material of the packing is not particularly limited, and examples thereof include steel, stainless steel, copper, carbon, ceramic, porcelain, glass, plastic, etc. The shape of the packing is also not particularly limited, and examples thereof include spheres, rings with smooth or shaped surfaces, rings with internal webs or wall cutouts, wire mesh rings, saddles, and spirals.
Packings with regular or ordered geometry may consist, for example, of thin plates or woven fabrics. Internal structures consisting of ordered packings are, for example, Sulzer woven packings BX made of metal or plastic, Sulzer layered packings from metal sheets, Sulzer's high-performance packings such as Mellapak, Mella-pakPlus, structured packings from Sulzer (Optiflow), Montz (BSH) and Kuehni (Rombopak).

<Method of producing 3-methyl-1-butene polymer>
The method for producing a 3-methyl-1-butene polymer of the present embodiment includes a step of polymerizing 3-methyl-1-butene, and is characterized in that the 3-methyl-1-butene has a purity of 99.5000 to 99.9940% as determined by gas chromatography and contains 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity.
Examples of the 3-methyl-1-butene used in the method for producing a 3-methyl-1-butene polymer include the 3-methyl-1-butene of the present embodiment described above.
Here, the 3-methyl-1-butene to be polymerized has a peak area intensity ratio of 3-methyl-1-butene to 2-methyl-1-butene determined by gas chromatography in the range of 99.9940:0.0070 to 99.5000 to 0.1700. Preferably, the 3-methyl-1-butene to be polymerized does not contain isobutene, 3-methyl-1-butanol, and di-(3-methylbutyl)ether or the contents of these components are below the detection limit.

[Comonomer]
In the step of polymerizing 3-methyl-1-butene, an olefin other than 3-methyl-1-butene can also be used as a comonomer.
When the above olefin is used, the 3-methyl-1-butene polymer produced is a copolymer of 3-methyl-1-butene and an olefin. The olefin may be, for example, an α-olefin having 2 to 20 carbon atoms.
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.

From the viewpoint of favorably exhibiting the properties of a 3-methyl-1-butene polymer, such as excellent heat resistance and a high melting point, the content of structural units derived from 3-methyl-1-butene in the 3-methyl-1-butene polymer is preferably 90 to 100 mol %, more preferably 95 to 100 mol %.
The content of the structural unit derived from the α-olefin in the copolymer can be determined by a Fourier transform infrared spectrophotometer (FT-IR). Specifically, it can be measured by the method described in the examples.

[catalyst]
(Polymerization catalyst)
In the step of subjecting 3-methyl-1-butene to polymerization, the polymerization reaction is not particularly limited, and the product can be produced using a catalyst containing a compound having a transition metal atom of Group 4 of the periodic table. Among them, 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 the inert hydrocarbon solvent used in the production of the magnesium-supported titanium catalyst include hexane, decane, and dodecane. Examples of the magnesium compound include anhydrous magnesium chloride, diethoxy magnesium, and methoxy magnesium chloride. Examples of the electron donor compound having an ester bond 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 the electron donor compound having an ether bond 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 to titanium atoms in the magnesium-supported titanium catalyst (halogen atoms/titanium atoms) is usually 2 to 100, and preferably 4 to 90. The molar ratio of electron donor compounds having ester bonds or ether bonds to titanium atoms in the magnesium-supported titanium catalyst (electron donor compounds/titanium atoms) is usually 0.01 to 100, and preferably 0.2 to 10. The atomic ratio of magnesium atoms to titanium atoms in the magnesium-supported titanium catalyst (magnesium atoms/titanium atoms) is usually 2 to 100, and 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.

Catalysts containing compounds having a transition metal atom of Group 4 of the periodic table include, for example, the solid titanium trichloride catalysts described in JP-A-54-107989, etc.; the magnesium-supported titanium catalysts described in JP-A-57-063310, JP-A-58-83006, JP-A-03-000706, Japanese Patent No. 3476793, JP-A-04-218508, JP-A-2003-105022, etc.; Metallocene catalysts described in Publication No. 2014/050817, International Publication No. 01/53369, International Publication No. 01/27124, JP-A-03-193796, or JP-A-02-041303, etc.; carrier-supported metallocene catalysts described in JP-A-2009-144148 or JP-A-2022-037931; so-called postmetallocene catalysts having titanium atoms or hafnium atoms described in non-patent literature Polyolefins Journal, Vol. 4, No. 1, pp. 123-136 (2017), or non-patent literature Macromolecules, Vol. 40, pp. 4130-4137 (2007), etc.; and the like 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 dichloride" 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 magnesium-supported titanium catalyst component, and is typically 0.1 to 1000 mol, preferably 0.5 to 500 mol, more preferably 1 to 200 mol per mole 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, and preferably from 0.05 to 4 MPaG. If the polymerization pressure is within the above range, devices such as a high pressure-resistant reactor and 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.The polymerization terminator is preferably a compound that reacts with a catalyst containing a compound having a transition metal atom of Group 4 of the periodic table.The polymerization terminator may be, for example, a compound having an active proton such as water, alcohol, primary amine, secondary amine, thiol, and Brestedt acid, or an ether, phosphine, tertiary amine, thioether, carbon dioxide, and oxygen molecule.
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 hydrogen, 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]
In the method for producing a 3-methyl-1-butene polymer according to the present embodiment, it is preferable to carry out a step of removing catalyst components contained in the polymer after the above-mentioned polymerization reaction. The method for removing the catalyst components is not particularly limited and may be a known method. For example, there may be mentioned a method in which an alcohol such as isobutanol or 2-propanol is added to the crude 3-methyl-1-butene polymer obtained by the above-mentioned polymerization reaction, the mixture is stirred at a temperature of about 10 to 100° C., and the polymer is 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 polymer obtained by the above-mentioned polymerization reaction, the mixture is treated at a temperature of about 10 to 100° C., and the polymer is separated.
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 polymer after the above-mentioned polymerization reaction may contain a polymerization component (hereinafter referred to as a "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 details of the soluble component are not clear, the soluble component may be an oligomer component of the 3-methyl-1-butene polymer, a polymer component with low stereoregularity, a polymer component with a low content of structural units derived from 3-methyl-1-butene, or the like. Therefore, when the soluble component is contained in the crude 3-methyl-1-butene polymer, the production method of the 3-methyl-1-butene polymer of the present embodiment may include a step of removing the soluble component, or the 3-methyl-1-butene polymer 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 polymer, 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 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 polymer]
In the method for producing a 3-methyl-1-butene polymer of the present embodiment, after the above-mentioned step of subjecting 3-methyl-1-butene to polymerization and various steps which are performed as necessary, a step of drying the obtained 3-methyl-1-butene polymer may be performed.
The drying is not particularly limited and may be performed by a known method. For example, the drying may be performed by removing volatile components under conditions of normal pressure to 1 mmHg and 20 to 200° C. During drying, the 3-methyl-1-butene polymer may be left stationary, may be fluidized by blowing air or an inert gas, or may be fluidized by a mechanical method such as using an agitating rotary blade type dryer, a rotary type dryer, a continuous tray type dryer, or a fluidized type dryer.

[Melting point of 3-methyl-1-butene polymer]
The melting point of the 3-methyl-1-butene polymer produced by the production method for a 3-methyl-1-butene polymer of the present embodiment is preferably 270 to 310° C., more preferably 280 to 305° C. When the melting point of the 3-methyl-1-butene polymer is within the above range, the 3-methyl-1-butene polymer has excellent heat resistance and can suitably exhibit the properties of a high melting point 3-methyl-1-butene polymer.
The melting point can be measured by the method described in the Examples.

<Resin composition containing 3-methyl-1-butene polymer>
The present embodiment can provide a resin composition containing a 3-methyl-1-butene polymer produced by the above-mentioned method for producing a 3-methyl-1-butene polymer.
The 3-methyl-1-butene polymer contained in the resin composition uses 3-methyl-1-butene as a monomer, in which the amount of the impurity 2-methyl-1-butene is limited. The 3-methyl-1-butene polymer exhibits excellent heat resistance by taking advantage of the high melting point of the 3-methyl-1-butene polymer, and is expected to have excellent mechanical property retention due to molecular weight retention by being more likely to have suitable fluidity for molding. Therefore, the same advantages can be expected for a resin composition containing the 3-methyl-1-butene polymer.

In addition to the 3-methyl-1-butene polymer, the resin composition may contain additives such as an antioxidant, an alkyl radical scavenger, an antacid, a filler, a light stabilizer, an antistatic agent, a flame retardant, a pigment, a polymerization inhibitor, a heavy metal deactivator, an ultraviolet absorber, a nucleating agent, a clarifying agent, a lubricant, a fluorescent brightening agent, and a rust inhibitor, as long as the effects of the present embodiment are not impaired.
The additives may be used alone or in combination of two or more kinds.

The resin composition can be produced by melt-kneading the 3-methyl-1-butene polymer and additives that can be added as needed using a known mixer. Examples of the mixer include a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, and a roll.

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

<1> 3-Methyl-1-butene With respect to the 3-methyl-1-butene obtained in the examples and comparative examples, the physical properties were measured or evaluated by the following methods.

[Composition ratio (Gas Chromatography (GC) analysis)]
The analysis of crude 3-methyl-1-butene and the analysis of purified 3-methyl-1-butene were carried out using a gas chromatograph GC2014 (Shimadzu Corporation: FID detector) and a capillary column (Agilent Technologies: DB-1, length 30 m, inner diameter 0.32 mm, film thickness 5.0 μm) in accordance with JIS K0114:2012 under the following conditions.
Column temperature: 40°C (10 min) → 5°C/min → 150°C (0 min) → 10°C/min → 280°C (5 min)
FID temperature: 250°C
Injection port temperature: 250°C
Carrier gas: Nitrogen Make-up gas: Nitrogen Injection amount: 0.2 μL
Column gas flow rate: 1.08 mL/min Split ratio: 50
The purity of each component in the crude 3-methyl-1-butene was determined from "GC peak area %," that is, "the percentage of the peak area of each compound to the sum of the peak areas of all compounds." Each analysis was performed three times, and the average value was used.
In addition, 3-methyl-1-butene, 2-methyl-1-butene, and 2-methyl-2-butene had the same peak detection sensitivity per the same mass, volume, and mole number. Therefore, the GC peak area % that represents the purity of each component (3-methyl-1-butene, 2-methyl-1-butene, and 2-methyl-2-butene) in the purified 3-methyl-1-butene is simply represented as "%" in this specification.

[Economics]
In the production of 3-methyl-1-butene, the reflux ratio was used as an index of economic efficiency and was evaluated. A reflux ratio of 4.0 or less was evaluated as "good" economic efficiency, and a reflux ratio of more than 4.0 was evaluated as "poor" economic efficiency.

<Production of crude 3-methyl-1-butene by dehydration reaction of 3-methyl-1-butanol>
[Production Example 1]
A stainless steel reaction tube with an inner diameter of 22 mm and a length of 1500 mm equipped with an evaporator was filled with 228 g (about 340 mL) of γ-alumina catalyst, and heated to 275° C. near the γ-alumina in the reaction tube. 3-Methyl-1-butanol (manufactured by Kuraray Co., Ltd., GC purity 99%) was introduced into the reaction tube at 7.6 mL/min (GHSV420 h ⁻¹ ). The reaction pressure was 0.02 MPaG. The gas coming out of the reactor was once cooled in a pipe cooled to 3° C., and then collected as a liquid in a trap cooled to about −79° C. The organic layer of the obtained liquid was transferred to a tank containing molecular sieves 4A (100 g of molecular sieves 4A was used per kg of organic layer), and water was removed to 0.0001 mass% or less. The organic layer thus obtained was analyzed by gas chromatography using the above method, and the composition was shown in Table 1.

<Purification of crude 3-methyl-1-butene>
[Example 1]
The crude 3-methyl-1-butene obtained in Production Example 1 was continuously fed to a pressure distillation tower having a tower length of 3000 mm, a tower diameter of 50A, and a theoretical number of 50 plates, from the 25th plate position counting from the top. The operation was performed under the conditions of a weight ratio of the distillate flow rate to the feed flow rate of about 0.75, an absolute pressure of 0.17 MPa, and a reflux ratio (weight ratio) of 2.3. The top temperature was 36°C, the tower bottom temperature was 48°C, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "E-1"). The obtained purified 3-methyl-1-butene was analyzed by gas chromatography using the above method. The results are shown in Table 2.

[Example 2]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 2.8 among the conditions described in Example 1, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "E-2"). The results of the gas chromatography analysis are shown in Table 2.

[Example 3]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 2.0 among the conditions described in Example 1, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "E-3"). The results of gas chromatography analysis are shown in Table 2.

[Comparative Example 1]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 4.7 among the conditions described in Example 1, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "C-1"). The results of gas chromatography analysis are shown in Table 2.

[Comparative Example 2]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 1.7, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "C-2"). The results of gas chromatography analysis are shown in Table 2.

[Example 4]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 3.0, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "E-4"). The results of gas chromatography analysis are shown in Table 3.

[Example 5]
Distillation was carried out in the same manner as in Example 1, except that the reflux ratio was changed to 4.0, and purified 3-methyl-1-butene was obtained as a distillate (hereinafter referred to as "E-5"). The results of gas chromatography analysis are shown in Table 3.

From Table 2, it can be seen that in Examples 1 to 3, 3-methyl-1-butene with a purity of 99.5000% or more was economically obtained at reflux ratios of 2.0, 2.3, and 2.8. From Table 3, it can be seen that in Examples 4 and 5, 3-methyl-1-butene with a purity of 99.5000% or more was economically obtained at reflux ratios of 3.0 and 4.0.
In Comparative Example 1, high-purity 3-methyl-1-butene could be obtained, but the reflux ratio needed was as high as 4.7, which is economically very disadvantageous.
In Comparative Example 2, 3-methyl-1-butene could be purified at a small reflux ratio, but the impurity 2-methyl-1-butene was contained at 0.2297%. In Comparative Example 2, the economic efficiency of 3-methyl-1-butene was evaluated as "good", but when the 3-methyl-1-butene (C-2) obtained in Comparative Example 2 was subjected to polymerization, the polymerization activity was reduced as shown in Comparative Example 4 described later, so that it was not economical.

<2> 3-Methyl-1-butene Polymers With respect to the 3-methyl-1-butene polymers obtained in the examples and comparative examples, various physical properties were measured or evaluated by the following methods.

[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 1,461 cm ^-1 bending vibration derived from the main chain methylene group of the 3-methyl-1-butene homopolymer to the peak area of 727 cm ^-1 bending vibration derived 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 structural units derived from α-olefins other than 3-methyl-1-butene.

[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 measured when the copolymers were held at −70° C. for 5 minutes and then heated to 320° C. at a rate of 10° C./min.

[Polymerization Activity]
The polymerization activity was calculated by the following formula.
Polymerization activity=mass (g) of 3-methyl-1-butene copolymer obtained by polymerization reaction ÷ mass (g) of catalyst added to polymerization reaction system
The higher the polymerization activity value, the smaller the amount of catalyst required to produce a polymer, which is economically advantageous.

[Activity retention rate]
The ratio (%) of 2-methyl-1-butene in 3-methyl-1-butene shown in Table 2 was plotted on the horizontal axis x, and the polymerization activity when polymerized at that composition was plotted on the vertical axis y, and an approximation of a linear function was performed to calculate the intercept. The y intercept on the vertical axis means the ideal activity value when the ratio of 2-methyl-1-butene is 0.000%. The activity retention was calculated using the following formula: Activity retention (%) = [Polymerization activity when 3-methyl-1-butene containing a specific concentration of 2-methyl-1-butene is polymerized ÷ y intercept] × 100
If the activity retention rate is low, it is necessary to increase the amount of catalyst used when the same amount of polymer is required to be produced, which is not economical.The activity retention rate is preferably 90% or more.

[Melt flow rate (MFR)]
As antioxidants, ADK STAB (registered trademark) AO-80 (manufactured by ADEKA Corporation), ADK STAB (registered trademark) PEP-36 (manufactured by ADEKA Corporation), and zinc stearate were used, and these antioxidants were added to the 3-methyl-1-butene polymers obtained in the Examples and Comparative Examples so that the AO-80 content was 0.65% by mass, the PEP-36 content was 1.33% by mass, and the zinc stearate content was 0.25% by mass, based on 100% by mass of the resin composition, and the mixture was melt-kneaded at 320° C. in a kneader to obtain a resin composition containing a 3-methyl-1-butene polymer.
The melt flow rate (MFR) of the obtained resin composition was measured in accordance with JIS K 7210:2014 (320°C, 2.16 kg load).
[Moldability]
Generally, the higher the MFR, the smaller the molecular weight and the higher the fluidity, and the lower the mechanical strength. Fluidity varies depending on the molding conditions, but in the case of injection molding, film molding, and spinning, especially injection molding, if the fluidity is too low, moldability is impaired. The above MFR was used as an index of moldability and was evaluated. When the MFR was less than 1.0 g/10 min, it was rated as "poor," and when it was more than 1.0 g/10 min, it was rated as "good."

[Economics]
In the production of 3-methyl-1-butene copolymers, the polymerization activity and activity retention were used as indicators of economic efficiency and were evaluated. An activity retention of 90% or more was evaluated as "good" economic efficiency, and an activity retention of less than 90% was evaluated as "poor" economic efficiency.

<Production of 3-methyl-1-butene copolymer>
[Example 6]
In a 1L stainless steel autoclave, 640g of 3-methyl-1-butene (E-1) obtained in Example 1, 48g of 1-decene, 5g of triethylaluminum solution diluted with hexane to a concentration of 1 mol/L, and 0.550g of magnesium-supported titanium catalyst (THC A, manufactured by Toho Titanium Co., Ltd.) were added, and a polymerization reaction was carried out at 70°C for 2 hours. After 2 hours, 10g of isoamyl alcohol was injected to stop the reaction, and excess unreacted monomer was expelled. Then, 200g of normal heptane was introduced, and the mixture was stirred at 60°C for 30 minutes, after which the solid content was filtered off with a pressure filter. This operation was repeated twice, and then the solvent was changed from 200g of normal heptane to 150g of 2-propanol, and the same operation was repeated twice.
The obtained crude 3-methyl-1-butene copolymer (71 g) was placed in a 1 L container equipped with a stirrer, and then 1 mol/L hydrochloric acid (100 g) and 2-propanol (200 g) were added and stirred for 1 hour. The suspension was filtered by vacuum filtration and washed with 200 g of 2-propanol. The crude 3-methyl-1-butene copolymer was placed in a 1 L container equipped with a stirrer, and then 200 g of 2-propanol was added and stirred for 1 hour. The suspension was filtered by vacuum filtration and washed with 200 g of 2-propanol. The obtained washed 3-methyl-1-butene copolymer was dried under reduced pressure at 80 ° C. for 1 day to obtain 61.05 g of 3-methyl-1-butene copolymer.
The obtained 3-methyl-1-butene copolymer was subjected to the above-mentioned measurements, and the melting point was found to be 295° C. The content of structural units derived from the comonomer 1-decene in the 3-methyl-1-butene copolymer was 1.2 mol %. The content of structural units derived from 3-methyl-1-butene calculated from the content of structural units derived from 1-decene was 98.8 mol %.
Moreover, the various physical properties of the resulting 3-methyl-1-butene copolymer were measured and evaluated by the above-mentioned methods. The results are shown in Table 4.

[Examples 7 and 8 and Comparative Examples 3 and 4]
A 3-methyl-1-butene copolymer was produced in the same manner as in Example 6, except that the monomer (3-methyl-1-butene) used was changed according to Table 4. The various physical properties of the obtained 3-methyl-1-butene copolymer were measured and evaluated by the above-mentioned methods. The results are shown in Table 4.

[Examples 9 and 10]
A 3-methyl-1-butene copolymer was produced in the same manner as in Example 6, except that the monomer (3-methyl-1-butene) used was changed according to Table 5. The various physical properties of the obtained 3-methyl-1-butene copolymer were measured and evaluated by the above-mentioned methods. The results are shown in Table 5.

In Table 4, a comparison between Examples 6 to 8 and Comparative Example 4 shows that the smaller the amount of 2-methyl-1-butene mixed in the monomer, the higher the polymerization activity and activity retention. In Table 5, a comparison between Examples 9 and 10 and Comparative Example 4 shows that the smaller the amount of 2-methyl-1-butene mixed in the monomer, the higher the polymerization activity and activity retention.
In Example 7, the amount of 2-methyl-1-butene mixed in the monomer E-2 was 0.0438%, and the MFR was 1.4 g/10 min. In contrast, in Comparative Example 3, the amount of 2-methyl-1-butene mixed in the monomer C-1 was as very small as 0.0049%, so that the polymerization activity was high but the MFR was 0.9 g/10 min, which was less than 1.0 g/10 min., and therefore it is understood that the 3-methyl-1-butene copolymer has poor fluidity and poor moldability.
In Examples 8 to 10, the amount of 2-methyl-1-butene in the monomer E-3 was 0.1512%, 0.0330%, and 0.0097%, respectively, and the activity retention was 92%, >99%, and >99%, respectively. On the other hand, in Comparative Example 4, the amount of 2-methyl-1-butene in the monomer C-2 was 0.2297%, and the activity retention was reduced to 88%, which is economically unfavorable.

Tables 4 and 5 show that 3-methyl-1-butene having a purity within a specific numerical range and a mixed amount of 2-methyl-1-butene within a specific numerical range can achieve both high polymerization activity and economic efficiency, and furthermore, 3-methyl-1-butene-based polymers and resin compositions thereof using this 3-methyl-1-butene tend to have fluidity (moldability) suitable for molding.

Claims

3-Methyl-1-butene having a purity of 99.5000-99.9940% as determined by gas chromatography and containing 0.0070-0.1700% of 2-methyl-1-butene as an impurity.
The process includes a step of polymerizing 3-methyl-1-butene,
The 3-methyl-1-butene has a purity of 99.5000 to 99.9940% as determined by gas chromatography;
The 3-methyl-1-butene contains 0.0070 to 0.1700% of 2-methyl-1-butene as an impurity.
A method for producing a 3-methyl-1-butene polymer.
The method for producing a 3-methyl-1-butene polymer according to claim 2, wherein the polymerization is carried out in the presence of a catalyst containing a compound having a Group 4 transition metal atom of the periodic table.
The method for producing a 3-methyl-1-butene polymer according to claim 3, wherein the catalyst is supported on a carrier.
A resin composition comprising a 3-methyl-1-butene polymer produced by the method for producing a 3-methyl-1-butene polymer according to any one of claims 2 to 4.