JP6673315B2 - Method for producing polymer - Google Patents

Description

  The present invention relates to a method for producing a polymer.

  Conventionally, as a polymer having excellent mechanical properties, a polymer of ethylene and aromatic vinyl (ethylene-aromatic vinyl polymer) is known (for example, Patent Document 1).

JP-A-3-250007

  Under these circumstances, the present inventors produced a polymer of ethylene and styrene (ethylene-styrene polymer) based on the example of Patent Document 1, and the obtained polymer was oxidatively degraded when heat was applied. It became clear that the film was easy to perform (insufficient oxidation deterioration resistance).

  In view of the above circumstances, an object of the present invention is to provide a method for producing a polymer capable of producing a polymer having excellent oxidation resistance.

As a result of the present inventors' earnest studies on the above problems, (i) when the above-mentioned ethylene-styrene polymer is produced by the method described in Patent Document 1, a head-to-head chain of styrene units ([- _{CH 2 -CH (C 5 H 6} ) -] [- CH (C 5 H 6) -CH 2 -]) and / or head - tail chain _{([-CH (C 5 H 6} ) -CH 2 -] [ —CH (C ₅ H ₆ ) —CH ₂ —]) is present in a small amount, but it is difficult to completely eliminate the chain. (Ii) The binding energy of the chain is small, and It has been found that it is easily broken by oxidation. In the following, among the chains of styrene units, chains other than the tail-to-tail chain ([—CH (C ₅ H ₆ ) —CH ₂ —] [— CH ₂ —CH (C ₅ H ₆ ) —]) That is, the head - head chain _{([-CH 2 -CH (C 5} H 6) -] [- CH (C 5 H 6) -CH 2 -]) and head - tail chain _([-CH (C 5 _{H 6 ) -CH 2 -] [- CH} (C 5 H 6) -CH 2 -]) are collectively referred to as "styrene chain". Similarly, among the chains of the aromatic vinyl units, a chain other than the tail-to-tail chain, that is, the head-to-head chain and the head-to-tail chain are collectively referred to as an “aromatic vinyl chain”.
The present invention is based on the above findings, and the specific configuration is as follows.

(1) A method for producing a polymer, comprising producing a polymer by reacting a diene polymer with an aromatic hydrocarbon which may have a substituent in the presence of a Lewis acid catalyst,
The diene-based polymer is composed of a repeating unit represented by the formula (3) described later and / or a repeating unit represented by the formula (4) described later, and is represented by the formula (3) among all the repeating units. The proportion of the repeating unit is 20 mol% or more, and the proportion of the repeating unit represented by the above formula (4) among all the repeating units is 80 mol% or less;
The polymer has a repeating unit represented by the formula (1) described later and / or a repeating unit represented by the formula (2) described later and a repeating unit represented by the formula (3) described later and / or And the proportion of the total of the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2) among all the repeating units is 0. It is more than 100 mol% and not more than 100 mol%, and the proportion of the total of the repeating unit represented by the above formula (3) and the repeating unit represented by the above formula (4) among all the repeating units is 0 mol% to 100 mol. %, And the proportion of the total of the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (3) among all the repeating units is 20 mol% or more. Of which is expressed by the above equation (2) Repeating units and the total proportion of the repeating unit represented by formula (4) is 80 mol% or less, the production method of the polymer is.
(2) The method for producing a polymer according to the above (1), wherein the aromatic hydrocarbon is an aromatic hydrocarbon having a substituent.
(3) The method for producing a polymer according to (2), wherein the substituent is an electron donating group.
(4) The method for producing a polymer according to (3), wherein the electron donating group is an alkoxy group.

  As described below, according to the present invention, it is possible to provide a method for producing a polymer capable of producing a polymer having excellent resistance to oxidation degradation.

Hereinafter, the method for producing the polymer of the present invention will be described.
In this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.

The method for producing the polymer of the present invention (hereinafter, also simply referred to as “the method of the present invention”)
In the presence of a Lewis acid catalyst, a polymer is produced by reacting a diene polymer with an aromatic hydrocarbon which may have a substituent, a method for producing a polymer,
The diene polymer comprises a repeating unit represented by the formula (3) described later and / or a repeating unit represented by the formula (4) described later, and is represented by the formula (3) among all the repeating units. The proportion of the repeating unit is 20 mol% or more, and the proportion of the repeating unit represented by the above formula (4) among all the repeating units is 80 mol% or less;
The above-mentioned polymer has a repeating unit represented by the following formula (1) and / or a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3) and / or the following formula (4) ), And the proportion of the total of the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2) among all the repeating units is more than 0 mol% 100 Mol% or less, and the proportion of the total of the repeating unit represented by the above formula (3) and the repeating unit represented by the above formula (4) among all the repeating units is 0 mol% or more and less than 100 mol%. The proportion of the total of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (3) in all the repeating units is 20 mol% or more, and the formula ( Repeated unit represented by 2) And the proportion of the total amount of the repeating unit represented by formula (4) is 80 mol% or less, a method for producing a polymer.

  It is not clear why the polymer obtained by the method of the present invention (hereinafter, also referred to as “the polymer of the present invention”) has excellent resistance to oxidation deterioration. It is considered that the polymer of the present invention does not have an aromatic vinyl chain having a small binding energy, so that it is difficult to be cut by oxidation when heated.

[Polymer]
First, the polymer of the present invention will be described using specific examples.
The following structural formula relates to one embodiment in which the polymer of the present invention is a polymer composed of a repeating unit represented by the formula (1) described below and a repeating unit represented by the formula (3) described later. It represents a part of the polymer (a part of the polymer chain). In the structural formula, Ph represents a phenyl group, and the number represents the number of the formula.

  The above structural formula has the same structure as that obtained by copolymerizing olefin (O), styrene (S) and butadiene (B) as follows.

Here, when styrene (S) is adjacent to each other, the tail-to-tail chain ([—CH (C ₅ H ₆ ) —CH ₂ —] [— CH ₂ —CH (C ₅ H ₆ ) —] ), And no head-to-tail or head-to-head linkage occurs. Thus, the polymer of the present invention has no styrene chain (aromatic vinyl chain).

  Hereinafter, each repeating unit will be described.

In the formulas (1) and (2), ^one of R ¹ and R ² represents an aromatic hydrocarbon group which may have a substituent, and the other represents a hydrogen atom.
In the formulas (1) to (4), R ^x and R ^y represent a hydrogen atom, an alkyl group or a halogen atom. However, at least one of R ^x and R ^y represents a hydrogen atom.

In the polymer of the present invention, the order of each repeating unit is not particularly limited.
The repeating unit represented by the above formula (3) does not distinguish between geometric isomers. That is, the repeating unit represented by (3) includes both a cis structure and a trans structure.

(Aromatic hydrocarbon group)
As described above, in the formulas (1) and (2), R ¹ and R ² each represent an aromatic hydrocarbon group which may have a substituent. The aromatic hydrocarbon group may be an aryl group or a heteroaryl group. That is, the aromatic hydrocarbon group may be a heterocyclic aromatic hydrocarbon group (heteroaryl group).
The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having a substituent, because the effect of the present invention is more excellent with respect to the obtained polymer. Hereinafter, "the effect of the present invention is more excellent with respect to the obtained polymer" is simply referred to as "the effect of the present invention is more excellent".

The ring constituting the aromatic hydrocarbon group is not particularly limited, but is preferably an aromatic hydrocarbon ring having 3 to 30 carbon atoms, and is preferably an aromatic ring having 6 to 20 carbon atoms, because the effect of the present invention is more excellent. More preferably, it is a group hydrocarbon ring.
Specific examples of the ring constituting the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, an oxazole ring, a furan ring, and a pyridine ring.

<Substituent>
The substituent is not particularly limited, but is preferably an electron donating group because the effect of the present invention is more excellent.
In the present specification, the electron donating group refers to a substituent having a Hammett's substituent constant σ _p value of 0 or less. The lower limit of the Hammett's substituent constant [sigma] _p value of the electron donating group is not particularly limited, but is preferably -0.8 or more, because the effect of the present invention is more excellent.
Here, the Hammett's substituent constant σ _p value will be described. Hammett's rule was introduced in 1935 by L.H. in 1935 to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. The substituent constants determined by Hammett's rule include a σ _p value and a σ _m value, and these values can be found in many general books. A. Dean ed., "Lang's and book of Chemistry", 12th edition, 1979 (McGraw-Hill) and extra edition of "Chemistry", No. 122, pp. 96-103, 1979 (Nankodo). In the present specification, the electron donating group is limited or described by Hammett's substituent constant σ _p, but this is limited only to a substituent having a known value in the literature found in the above-mentioned textbook. It does not mean that. Even if the value is unknown in the literature, it includes a substituent included in the range when measured based on the Hammett rule.

Specific examples of the electron donating group include a hydroxy group or a salt thereof, a mercapto group or a salt thereof, an alkyl group (preferably having 1 to 30 carbon atoms), an alkoxy group (preferably having 1 to 30 carbon atoms), and an aryloxy group. Group (preferably having 6 to 20 carbon atoms), a heterocyclic oxy group, an alkylthio group (RS-: R represents an alkyl group (preferably having 1 to 30 carbon atoms)), an arylthio group (preferably having 6 carbon atoms). To 20), a heterocyclic thio group, an amino group, and an alkylamino group (R ¹ R ² N—: R ¹ and R ² each independently represent a hydrogen atom or an alkyl group (preferably having 1 to 30 carbon atoms). However, at least one of R ¹ and R ² represents an alkyl group), an arylamino group (preferably having 6 to 20 carbon atoms), a heterocyclic amino group, and the like. Among them, a group having a Hammett's substituent constant σ _p value of −0.15 or less is preferable because the effect of the present invention is more excellent. Specifically, it is preferably a group other than an alkyl group having a Hammett's substituent constant σ _p value of more than -0.15, and more preferably an alkoxy group.

  In addition, when the said aromatic hydrocarbon group has two or more substituents, it may combine with each other and may form a ring. For example, propylenyl groups substituting carbons adjacent to a phenyl group may be bonded to each other to form a benzene ring (to be a naphthyl group as a whole).

  Examples of the aromatic hydrocarbon group having a substituent include a tolyl group (toluene group), a methoxyphenyl group (anisole group), and a naphthyl group.

[R ^x and R ^y ]
As described above, in the formulas (1) to (4), R ^x and R ^y represent a hydrogen atom, an alkyl group, or a halogen atom. However, at least one of R ^x and R ^y represents a hydrogen atom.
It is preferable that ^Rx and ^Ry are hydrogen atoms because the effect of the present invention is more excellent.
The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group, because the effect of the present invention is more excellent.
The halogen atom is not particularly limited, but is preferably a chlorine atom because the effect of the present invention is more excellent.

[Ratio of repeating unit]
Hereinafter, the ratio of each repeating unit will be described.
The polymer of the present invention comprises a repeating unit represented by the above formula (1) and / or a repeating unit represented by the above formula (2) and a repeating unit represented by the formula (3) and / or Since it is composed of the repeating unit represented by the formula (4), the proportion occupied by the repeating unit represented by the above formula (1) and the proportion occupied by the repeating unit represented by the above formula (2) among all the repeating units The sum of the proportion occupied by the repeating unit represented by the above formula (3) and the proportion occupied by the repeating unit represented by the above formula (4) is 100 mol%.

<Formula (1)>
The proportion occupied by the repeating unit represented by the repeating unit represented by the above formula (1) (hereinafter, also referred to as “d1”) among all the repeating units is from 1 to 50 because the effect of the present invention is more excellent. Mol%, more preferably 5 to 40 mol%.

<Formula (2)>
The proportion of the repeating unit represented by the formula (2) among all the repeating units (hereinafter, also referred to as “d2”) is from 1 to 50 because the effect of the present invention is more excellent. Mol%, more preferably 5 to 40 mol%.

<Equation (3)>
The proportion of the repeating unit represented by the above formula (3) among all the repeating units (hereinafter, also referred to as “d3”) is from 30 to 95 because the effect of the present invention is more excellent. Mol%, more preferably 60 to 90 mol%.

<Equation (4)>
The proportion occupied by the repeating unit represented by the repeating unit represented by the above formula (4) (hereinafter, also referred to as “d4”) in all the repeating units is from 1 to 70, because the effect of the present invention is more excellent. Mol%, more preferably 5 to 60 mol%.

<Equation (1) + Equation (2)>
Among all the repeating units, the proportion of the total of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) (hereinafter, also referred to as “d1 + d2”) is more than 0 mol% 100 Mol% or less. Especially, from the reason that the effect of the present invention is more excellent, it is preferred that it is 1 to 50 mol%, and it is more preferred that it is 5 to 40 mol%.

<Equation (3) + Equation (4)>
The proportion of the total of the repeating unit represented by the above formula (3) and the repeating unit represented by the above formula (4) (hereinafter, also referred to as “d3 + d4”) in all the repeating units is 0 mol% or more and 100 mol% or more. Less than mol%. Especially, from the reason that the effect of the present invention is more excellent, it is preferred that it is 51-99 mol%, and it is more preferred that it is 60-95 mol%.
As described above, d3 + d4 may be 0 mol%. That is, the polymer of the present invention may be a polymer having neither the repeating unit represented by the formula (3) nor the repeating unit represented by the formula (4). In other words, the polymer of the present invention may be a polymer comprising the repeating unit represented by the above formula (1) and / or the repeating unit represented by the above formula (2).

<Equation (1) + Equation (3)>
The proportion of the total of the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (3) among all the repeating units (hereinafter, also referred to as “d1 + d3”) is at least 20 mol%. is there. Especially, from the reason that the effect of the present invention is more excellent, it is preferred that it is 30-99 mol%, and it is more preferred that it is 50-99 mol%.

<Equation (2) + Equation (4)>
The proportion of the total of the repeating unit represented by the above formula (2) and the repeating unit represented by the above formula (4) among all the repeating units (hereinafter, also referred to as “d2 + d4”) is 80 mol% or less. is there. Especially, from the reason that the effect of the present invention is more excellent, it is preferred that it is 0.01-70 mol%, and it is more preferred that it is 1-50 mol%.
The above d2 + d4 may be 0 mol%. That is, the polymer of the present invention may be a polymer having neither the repeating unit represented by the above formula (2) nor the repeating unit represented by the above formula (4). In other words, the polymer of the present invention may be a polymer comprising a repeating unit represented by the above formula (1) and / or a repeating unit represented by the above formula (3).

  Hereinafter, the ratio (molar ratio) of d1, d2, d3, and d4 is also referred to as “d1 / d2 / d3 / d4”.

(Molecular weight)

<Weight average molecular weight>
The weight average molecular weight (Mw) of the polymer of the present invention is not particularly limited, but is preferably from 100 to 10,000,000, and more preferably from 200 to 1,000,000, for the reason that the effect of the present invention is more excellent. Is more preferable.

<Number average molecular weight>
The number average molecular weight (Mn) of the polymer of the present invention is not particularly limited, but is preferably from 100 to 10,000,000, and more preferably from 200 to 1,000,000, for the reason that the effect of the present invention is more excellent. Is more preferable.

<Molecular weight distribution>
The molecular weight distribution (Mw / Mn) of the polymer of the present invention is not particularly limited, but is preferably 10 or less, more preferably 5 or less, because the effect of the present invention is more excellent. The lower limit of the molecular weight distribution is not particularly limited, but is usually 1.0 or more.

The above Mw and Mn are values in terms of standard polystyrene obtained by gel permeation chromatography (GPC) measurement under the following conditions.
・ Solvent: tetrahydrofuran ・ Detector: RI detector

〔Glass-transition temperature〕
The glass transition temperature (Tg) of the polymer of the present invention is not particularly limited, but is preferably −150 to 200 ° C., and more preferably −120 to 150 ° C., because the effect of the present invention is more excellent. .
In this specification, the glass transition temperature (Tg) is measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC), and calculated by the midpoint method.

[Application]
Since the polymer of the present invention has excellent mechanical properties and excellent resistance to oxidation deterioration, it can be suitably used for various plastic materials and rubber materials.

[Method for producing polymer]

As described above, in the method of the present invention, a diene polymer is reacted with an aromatic hydrocarbon which may have a substituent in the presence of a Lewis acid catalyst.
The reason why the above-mentioned polymer of the present invention can be obtained by the method of the present invention is presumed to be as follows. That is, a proton is added to the double bond of the diene polymer by the Lewis acid catalyst to generate a carbocation. Then, it is considered that the above-mentioned polymer of the present invention can be obtained by electrophilic substitution of the aromatic hydrocarbon which may have a substituent with the generated carbocation (Friedel-Crafts type) ).

Hereinafter, specific examples of the method of the present invention will be described using reaction formulas.
The following reaction formula shows an example in which the Lewis acid catalyst is aluminum chloride (AlCl ₃ ), the diene-based polymer is butadiene rubber (BR), and the aromatic hydrocarbon is toluene. (A part of the polymer chain). In the reaction formula, Ty represents a tolyl group.

As shown in the above reaction formula, part of the double bond of the butadiene rubber becomes a single bond and has a structure in which a tolyl group derived from toluene is bonded. The rest remains a double bond. Thus, the above-mentioned polymer of the present invention is obtained.
When the ratio of all double bonds reacted is referred to as “denaturation ratio”, the denaturation ratio in the above reaction formula is about 56% (= 5/9). The modification rate can be changed, for example, by adjusting the reaction temperature, the reaction time, and the ratio of the amount of the aromatic hydrocarbon which may have a substituent to the amount of the diene-based polymer used.

  Hereinafter, the components used in the method of the present invention will be described.

(Diene polymer)
The diene-based polymer is composed of a repeating unit (1,4-structure) represented by the above formula (3) and / or a repeating unit (vinyl structure) represented by the above formula (4). The proportion of the repeating unit represented by the above formula (3) is at least 20 mol%, and the proportion of the repeating unit represented by the above formula (4) among all the repeating units is at most 80 mol%. Is a polymer.

The repeating unit represented by the above formula (3) and the repeating unit represented by the above formula (4) are as described above.
In the diene polymer, the order of each repeating unit is not particularly limited.
The repeating unit represented by the above formula (3) does not distinguish between geometric isomers. That is, the repeating unit represented by (3) includes both a cis structure and a trans structure.

  As described above, in the diene-based polymer, the proportion of the repeating unit represented by the formula (3) among all the repeating units is 20 mol% or more. Especially, from the reason that the effect of the present invention is more excellent, it is preferred that it is 30-95 mol%, and it is more preferred that it is 60-90 mol%.

  As described above, in the diene-based polymer, the proportion of the repeating unit represented by the formula (4) among all the repeating units is 80 mol% or less. Among them, from the reason that the effect of the present invention is more excellent, it is preferably 1 to 70 mol%, more preferably 5 to 60 mol%.

  Hereinafter, "the proportion (mol%) of the repeating unit (1,4-structure) represented by the above formula (3) among all the repeating units, and the proportion (mol%) of the whole repeating unit represented by the above formula (4) The ratio (mol%) of the repeating unit (vinyl structure) "is also referred to as" 1,4-structure / vinyl structure ".

  Specific examples of the diene polymer include butadiene rubber (BR), isoprene rubber (IR), and chloroprene rubber (CR). Among them, BR is preferable because the effect of the present invention is more excellent.

  The molecular weight of the diene polymer is not particularly limited. Preferred embodiments of Mw, Mn and Mw / Mn of the diene-based polymer and the reason thereof are the same as those of the polymer of the present invention described above.

(Lewis acid catalyst)
The Lewis acid catalyst is not particularly limited, and a known Lewis acid catalyst can be used.
Specific examples of the Lewis acid catalyst include, for example, aluminum chloride, aluminum bromide, iron chloride, iron bromide, titanium chloride, titanium bromide, and the like. Aluminum is preferred.

  The use amount of the Lewis acid catalyst is not particularly limited, but is preferably 0.1 to 10% by mass based on the use amount of the diene-based polymer because the effect of the present invention is more excellent.

(Aromatic hydrocarbon)
The aromatic hydrocarbon is not particularly limited.
Specific examples and preferable embodiments of the aromatic hydrocarbon include, for example, an aromatic hydrocarbon obtained by adding a hydrogen atom to a bonding position of the above-described aromatic hydrocarbon group. More specifically, for example, toluene obtained by adding a hydrogen atom to the bonding position of the tolyl group, anisole obtained by adding a hydrogen atom to the bonding position of the methoxyphenyl group, a hydrogen atom at the bonding position of the naphthyl group And naphthalene obtained by the addition. In addition, the reason of a suitable aspect is the same as the above-mentioned aromatic hydrocarbon group.

  The amount of the aromatic hydrocarbon to be used is not particularly limited, but is preferably from 1 to 100,000% by mass based on the amount of the diene-based polymer, because the effect of the present invention is more excellent.

(Reaction conditions)
In the method of the present invention, the reaction conditions are not particularly limited, but the reaction temperature is preferably 40 to 120 ° C. for the reason that the effect of the present invention is more excellent, and the reaction time is the reason that the effect of the present invention is more excellent. From 0.1 to 1000 hours.

(Reaction stop method)
In the method of the present invention, the method for terminating the reaction is not particularly limited, and examples thereof include a method of inactivating the Lewis acid catalyst with an alcohol (preferably, methanol).

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

(Production of polymer)
A polymer was produced as described below.

<Example 1>
30 g of BR (Mw = 8,100, Mw / Mn = 1.1, 1,4-structure / vinyl structure = 69/31) was dissolved in toluene (300 mL) and heated to 80 ° C., and then aluminum chloride (2 .0 g) and stirred for 8 hours. Thereafter, the reaction was stopped by adding methanol. Then, the reaction solution was concentrated under reduced pressure, and the concentrated reaction solution was poured into methanol (500 mL) to separate a methanol-insoluble component, thereby obtaining 35 g of a polymer.
The obtained polymer has a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2), and a repeating unit represented by the above formula (3) and the above formula It was a polymer comprising the repeating unit represented by (4). Here, in the formulas (1) and (2), ^one of R ¹ and R ² represents a tolyl group, and the other represents a hydrogen atom. In the formulas (1) to (4), ^Rx and ^Ry represent a hydrogen atom.
Moreover, d1 / d2 / d3 / d4 of the obtained polymer was 7/3/62/28, Mw was 9,800, Mw / Mn was 1.7, and Tg was -7 ° C.

<Example 2>
30 g of BR (Mw = 4.6 × 10 ⁵ , Mw / Mn = 2.9, 1,4-structure / vinyl structure = 99/1) is dissolved in anisole (300 mL), heated to 80 ° C., and then chlorided. Aluminum (1.0 g) was added and stirred for 4 hours. Thereafter, the reaction was stopped by adding methanol. Then, the reaction solution was concentrated under reduced pressure, and the concentrated reaction solution was poured into methanol (500 mL) to separate a methanol-insoluble component, thereby obtaining 38 g of a polymer.
The obtained polymer has a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2), and a repeating unit represented by the above formula (3) and the above formula It was a polymer comprising the repeating unit represented by (4). Here, in the formulas (1) and (2), ^one of R ¹ and R ² represents a methoxyphenyl group, and the other represents a hydrogen atom. In the formulas (1) to (4), ^Rx and ^Ry represent a hydrogen atom.
In addition, d1 / d2 / d3 / d4 of the obtained polymer was 15 / 0.2 / 84 / 0.8, Mw was 3.4 × 10 ⁵ , Mw / Mn was 2.6, and Tg was −65 ° C. Met.

<Example 3>
30 g of BR (Mw = 8,100, Mw / Mn = 1.1, 1,4-structure / vinyl structure = 69/31) was dissolved in anisole (300 mL) and heated to 80 ° C., and then aluminum chloride (1 .0 g) and stirred for 8 hours. Thereafter, the reaction was stopped by adding methanol. Then, the reaction solution was concentrated under reduced pressure, and the concentrated reaction solution was poured into methanol (500 mL) to separate a methanol-insoluble component, thereby obtaining 85 g of a polymer.
The obtained polymer was a polymer comprising the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2). Here, in the formulas (1) and (2), ^one of R ¹ and R ² represents a methoxyphenyl group, and the other represents a hydrogen atom. In the formulas (1) and (2), ^Rx and ^Ry represent a hydrogen atom.
Moreover, d1 / d2 / of the obtained polymer was 69/31, Mw was 9,200, Mw / Mn was 1.5, and Tg was 123 ° C.

<Comparative Example 1>
Referring to Example 1 of Patent Document 1, an ethylene-styrene polymer was produced by polymerizing ethylene and styrene. The presence of a styrene chain (aromatic vinyl chain) in the obtained polymer was confirmed.

  The structure of the obtained polymer is summarized in Table 1 below.

In Table 1, the column of aromatic hydrocarbon group represents an aromatic hydrocarbon group represented by R ¹ or R ² in the above formulas (1) and (2).
In Table 1, the columns of d1 to d4, d1 + d2, d3 + d4, d1 + d3, and d2 + d4 represent the above-described d1 to d4, d1 + d2, d3 + d4, d1 + d3, and d2 + d4, respectively.
In Table 1, the column of aromatic vinyl chain indicates the presence or absence of the above-mentioned aromatic vinyl chain.

(Oxidation degradation resistance)
Each obtained polymer was heated, and the Mw retention ratio before and after heating (= Mw after heating / Mw before heating) was determined. As a result, as compared with a polymer having an aromatic vinyl chain obtained by the method of Comparative Example 1, the polymer does not have an aromatic vinyl chain obtained by the method of Examples 1 to 3, which is the method of the present invention. The polymer had a high Mw retention rate and exhibited excellent oxidation degradation resistance.

  Further, while the method of Comparative Example 1 required the synthesis of a catalyst (the synthesis of the catalyst required 30 hours or more), the methods of Examples 1 to 3 were extremely simple.

Claims (4)

In the presence of a Lewis acid catalyst, a polymer is produced by reacting a diene polymer with an aromatic hydrocarbon which may have a substituent, a method for producing a polymer,
The diene-based polymer is composed of a repeating unit represented by the following formula (3) and / or a repeating unit represented by the following formula (4), and among all the repeating units, a repeating unit represented by the formula (3) Is 20 mol% or more, and the proportion of the repeating unit represented by the formula (4) is 80 mol% or less in all the repeating units,
The polymer has a repeating unit represented by the following formula (1) and / or a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3) and / or the following formula (4) ), And the proportion of the total of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) among all the repeating units is 1 mol% or more and 100 or more. Mol% or less, and the proportion of the total of the repeating unit represented by the formula (3) and the repeating unit represented by the formula (4) in all the repeating units is 0 mol% or more and 99 mol% or less. And the proportion of the total of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (3) in all the repeating units is 20 mol% or more, and the formula ( Repeated unit represented by 2) And is 80 mol% or less the ratio of the total amount of the repeating unit represented by the formula (4), the production method of the polymer.

In the formulas (1) and (2), ^one of R ¹ and R ² represents an aromatic hydrocarbon group which may have a substituent, and the other represents a hydrogen atom. However, a hydroxy group is excluded from the substituent. In addition, a group having a group represented by the following formula (X) and a group having a group represented by the following formula (Y) are excluded from the aromatic hydrocarbon group which may have a substituent. .
In the formulas (1) to (4), R ^x and R ^y represent a hydrogen atom, an alkyl group or a halogen atom. However, at least one of R ^x and R ^y represents a hydrogen atom.
_{^{* -C (R Z) 2 -CR}} Z R W -CR Z R W -C (R Z) 2 - * (X)
_{^{* -CR Z R W -C (R}} Z) 2 -CR Z R W -C (R Z) 2 - * (Y)
In formula (X) and (Y), R ^Z represents a hydrogen atom or a substituent, R ^W represents an aromatic hydrocarbon group which may have a substituent, and * represents a bonding hand. A plurality of ^RZs may be the same or different. A plurality of ^RWs may be the same or different.   The method for producing a polymer according to claim 1, wherein the aromatic hydrocarbon is an aromatic hydrocarbon having a substituent.   The method for producing a polymer according to claim 2, wherein the substituent is an electron donating group.   The method for producing a polymer according to claim 3, wherein the electron donating group is an alkoxy group.