WO2025169726A1 - Metal residue remover, metal residue remover system, production method for hydrogenated conjugated diene polymer, and hydrogenated conjugated diene polymer composition - Google Patents

Abstract

A metal residue remover that forms a complex with a metal residue when added to a polymer solution containing the metal residue, the topological polar surface area (TPSA) of the remover being 138 or less.

Description

Metal residue remover, metal residue remover system, method for producing hydrogenated conjugated diene polymer, and hydrogenated conjugated diene polymer composition

The present invention relates to a metal residue remover, a metal residue remover system, a method for producing a hydrogenated conjugated diene polymer, and a hydrogenated conjugated diene polymer composition.

In recent years, thermoplastic elastomers have come into widespread use in a wide range of fields as soft materials with rubber elasticity that do not require a vulcanization process and can be molded and recycled in the same way as thermoplastic resins.

Examples of such thermoplastic elastomers include polymers of conjugated diene compounds such as 1,3-butadiene and isoprene, or copolymers of conjugated diene compounds with vinyl aromatic compounds such as styrene that are copolymerizable with the conjugated diene compounds. These are highly useful as modifiers or adhesives for various materials such as impact-resistant transparent resins, polyolefins, polystyrene resins, and asphalt.

Furthermore, hydrogenated conjugated diene polymers, in which hydrogen is added to the olefinic double bonds contained in the conjugated diene polymers, have excellent weather resistance. Utilizing this characteristic, the hydrogenated conjugated diene polymers are used in automobile parts, home appliance parts, electrical wire coatings, medical parts, miscellaneous goods, footwear, protective films, adhesives, and more.

Generally, conjugated diene polymers are produced by living anionic polymerization using alkyllithium or the like as a polymerization initiator. Furthermore, after polymerization, the olefinic double bonds are subjected to a hydrogenation reaction (hereinafter also referred to as "hydrogenation reaction" or "hydrogenation reaction") using a transition metal as a catalyst, thereby obtaining the hydrogenated conjugated diene polymer.

Various methods have been reported for hydrogenating conjugated diene polymers having olefinic double bonds.
For example, a method is known in which a conjugated diene polymer is hydrogenated using a catalyst that combines a compound of a metal of Group VIII of the periodic table, particularly nickel or cobalt, with a predetermined reducing agent such as an alkylaluminum compound. Another method is known in which an unsaturated double bond of a conjugated diene polymer is hydrogenated using a catalyst that combines a compound of titanium, which is a metal of Group IV of the periodic table, such as a bis(cyclopentadienyl)titanium compound, with a predetermined reducing agent such as an alkylaluminum compound or an alkyllithium compound.

As described above, thermoplastic elastomers, particularly the above-mentioned conjugated diene polymers and hydrogenated conjugated diene polymers, contain metal residues derived from polymerization initiators, hydrogenation catalysts, and the like in the production process.
Metal residues in polymer solutions can cause various quality problems, such as lumps in the product, rough surfaces of molded products, discoloration, reduced transparency, and clogged filters during processing, so they must be efficiently removed during the manufacturing process.

As a specific method for producing a conjugated diene polymer, Patent Document 1 discloses a method for producing a conjugated diene polymer using an organolithium compound and a titanocene compound.

JP 2014-129479 A

As mentioned above, metal catalysts are generally used to produce conjugated diene polymers, resulting in polymer solutions containing metal residues. These metal residues pose a problem in that they can potentially lead to a decline in the quality of the polymer product.

In view of the problems of the prior art described above, the present invention aims to provide a metal residue remover that efficiently removes metal residues from polymer solutions containing such metal residues, a metal residue remover system containing the metal residue remover, a method for producing a hydrogenated conjugated diene polymer using the same, and a hydrogenated conjugated diene polymer composition.

The present inventors have conducted extensive research to solve the problems of the conventional techniques described above, and as a result have found that a high metal removal effect can be achieved by using a metal residue remover in which the TPSA (Topological Polar Surface Area) is specified to be equal to or less than a predetermined value for a polymer solution containing metal residues, and have thus completed the present invention.
That is, the present invention is as follows.

[1]
A metal residue remover that forms a complex with a metal residue when added to a polymer solution containing the metal residue,
TPSA (Topological Polar Surface Area) is 138 or less;
Metal residue remover.
[2]
an organic compound having at least two polar functional groups;
The metal residue remover according to [1] above.
[3]
one of the at least two polar functional groups
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to [2] above.
[4]
A metal residue remover having one each of the following functional group 1 and the following functional group 2,
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The functional group 2 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
a secondary amino group, and an imino group;
The metal residue remover according to any one of [1] to [3] above.
[5]
A metal residue remover having one each of the following functional group 1 and the following functional group 2,
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The functional group 2 is
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is selected from the group consisting of a secondary amino group and an imino group;
When the functional group 1 and the functional group 2 are all any one selected from the group consisting of a hydroxy group (excluding a hydroxy group in a carboxyl group) and an ether group (excluding an ether group in an ester group), there are three or more atoms other than O atoms between any O atom contained in the functional group 1 and the functional group 2 and any other O atom.
The metal residue remover according to any one of [1] to [3] above.
[6]
A metal residue remover having three or more of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to any one of [1] to [3] above.
[7]
A metal residue remover having three of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
When all of the three functional groups 1 are selected from the group consisting of hydroxy groups (excluding hydroxy groups in carboxyl groups) and ether groups (excluding ether groups in ester groups), there are three or more atoms other than O atoms between any O atom contained in the functional group 1 and any other O atom.
The metal residue remover according to any one of [1] to [3] above.
[8]
A metal residue remover having four or more of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to any one of [1] to [3] above.
[9]
The metal residue is at least one selected from the group consisting of alkali metals, alkaline earth metals, transition metals, and earth metals.
The metal residue remover according to any one of [1] to [8] above.
[10]
The metal residue is at least one selected from the group consisting of lithium, nickel, cobalt, titanium, and aluminum.
The metal residue remover according to any one of [1] to [9] above.
[11]
The metal residue is at least one selected from the group consisting of nickel, cobalt, and titanium.
The metal residue remover according to any one of [1] to [10] above.
[12]
The metal residue is at least one selected from the group consisting of lithium and titanium.
The metal residue remover according to any one of [1] to [11] above.
[13]
The metal residue is titanium.
The metal residue remover according to any one of [1] to [12] above.
[14]
The polymer solution is a conjugated diene-based polymer solution.
The metal residue remover according to any one of [1] to [13] above.
[15]
The polymer solution is a hydrogenated conjugated diene-based polymer solution.
The metal residue remover according to any one of [1] to [14] above.
[16]
the solvent of the polymer solution is any one selected from the group consisting of cyclohexane, normal hexane, methylcyclohexane, and mixtures thereof;
The metal residue remover according to any one of [1] to [15] above.
[17]
the metal residue is titanium originating from a hydrogenation catalyst,
the metal residue removing agent is added in an amount of 10 in a molar ratio relative to the titanium constituting the hydrogenation catalyst in the polymer solution, thereby forming a complex with titanium that accounts for 36 mass % or more of the total titanium in the polymer solution;
The metal residue remover according to any one of [1] to [16] above.
[18]
The metal residue remover has a structure shown in formula (I):
The metal residue remover according to any one of [1] to [17] above.

 

In formula (I), R ¹ is any one selected from the group consisting of C(R ³ ) ₂ OH, C(R ³ )═O, hydrogen, an alkyl group containing 1 to 3 carbon atoms, and an alkoxy group containing 1 to 3 carbon atoms;
^R2 is any one selected from the group consisting of C( ^R3 ) _2OH and C( ^R3 )=O;
Each ^R3 is independently any one selected from the group consisting of hydrogen and an alkyl group containing 1 to 3 carbon atoms.

[19]
The metal residue remover has a structure shown in formula (II):
The metal residue remover according to any one of [1] to [17] above.

 

In formula (II), R ⁴ is any one selected from the group consisting of hydrogen and alkyl groups containing 1 to 3 carbon atoms.

[20]
The metal residue remover has a structure shown in formula (III):
The metal residue remover according to any one of [1] to [17] above.

 

In formula (III), each R ⁵ is independently an alkylene group containing 1 to 4 carbon atoms.

[21]
The molecular weight of the metal residue removing agent is 250 or less.
The metal residue remover according to any one of [1] to [20] above.
[22]
The metal residue remover according to any one of [1] to [21] above,
A surfactant,
containing
Metal residue remover system.
[23]
The surfactant is an aliphatic carboxylic acid having 8 to 18 carbon atoms.
The metal residue remover system according to [22] above.
[24]
Step 1: obtaining a conjugated diene polymer in the presence of a polymerization initiator, and hydrogenating the conjugated diene polymer in the presence of a hydrogenation catalyst to obtain a hydrogenated conjugated diene polymer solution;
a step 2 of mixing the metal residue removing agent according to any one of claims 1 to 21 with the hydrogenated conjugated diene polymer solution to obtain a complex;
and a step 3 of separating the complex to separate and recover the hydrogenated conjugated diene polymer.
A method for producing a hydrogenated conjugated diene polymer.
[25]
In the step 2, a surfactant is mixed in an amount of 0.5 parts by mass or less relative to 100 parts by mass of the hydrogenated conjugated diene-based polymer.
The method for producing the hydrogenated conjugated diene polymer according to [24] above.
[26]
The surfactant is an aliphatic carboxylic acid having 8 to 18 carbon atoms.
The method for producing the hydrogenated conjugated diene polymer according to [25] above.
[27]
The method for separating the complex in step 3 is extraction into an aqueous layer.
The method for producing a hydrogenated conjugated diene polymer according to [25] or [26] above.
[28]
In the step 2, the metal residue removing agent is added in an amount of 0.001 to 10 parts by mass per 100 parts by mass of the hydrogenated conjugated diene polymer solution.
The method for producing a hydrogenated conjugated diene polymer according to any one of [24] to [27].
[29]
A method for removing metal residue comprising the steps of: removing a hydrogenated conjugated diene polymer; removing metal residue; and removing the metal residue remover according to claim 1.
The content of the metal residue remover is 0.1 to 100 ppm.
Hydrogenated conjugated diene polymer composition.

The present invention provides a metal residue remover that can efficiently remove metal residues remaining in a polymer solution, and a hydrogenated conjugated diene polymer with low metal residues.

The following describes in detail the form for implementing the present invention (hereinafter referred to as the "present embodiment"). The present invention is not limited to the following embodiment, and can be implemented in various modifications within the scope of its gist.

[Metal residue remover]
The metal residue remover of the present embodiment is
The metal residue remover forms a complex with the metal residue when added to a polymer solution containing the metal residue, and has a TPSA (Topological Polar Surface Area) of 138 or less.
By having the above-described configuration, the metal residue remover of the present embodiment can efficiently remove metal residue remaining in the polymer solution.
The metal residue remover of this embodiment has a moderate polarity, which allows it to strongly interact with metal atoms to form complexes, thereby exerting the effect of removing metal residues.

From the viewpoint of interaction with metal atoms, the metal residue remover of this embodiment is preferably an organic compound having a polar functional group. Among polar functional groups, hydroxy groups (excluding hydroxy groups in carboxyl groups), carbonyl groups (excluding carbonyl groups in carboxyl groups), ether groups (excluding ether groups in ester groups), primary amino groups, secondary amino groups, tertiary amino groups, and imino groups tend to interact strongly with metal atoms. In particular, hydroxy groups (excluding hydroxy groups in carboxyl groups), carbonyl groups (excluding carbonyl groups in carboxyl groups), ether groups (excluding ether groups in ester groups), amino groups, and imino groups tend to interact strongly with metal atoms in this order, and among amino groups, tertiary amino groups, secondary amino groups, and primary amino groups tend to interact strongly with metal atoms in this order.
In general, the more polar functional groups there are, the higher the polarity tends to be. Among the polar functional groups, the polarity tends to be higher when there is a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, or an imino group. Among these polar functional groups, the polarity tends to be higher in the order of hydroxy group (excluding the hydroxy group in a carboxyl group), amino group, carbonyl group (excluding the carbonyl group in a carboxyl group), imino group, and ether group (excluding the ether group in an ester group). Among amino groups, the polarity tends to be higher in the order of primary amino group, secondary amino group, and tertiary amino group.
In general, the more polar functional groups there are, the more likely they are to interact strongly with metal atoms.
Furthermore, when heteroatoms in the polar functional group are spaced apart at an appropriate distance, they tend to interact strongly with the metal atom. Specifically, the distance is preferably 1 to 5 atoms, more preferably 2 to 5 atoms, and even more preferably 3 to 4 atoms.

(TPSA)
The metal residue remover of this embodiment has a TPSA (Topological Polar Surface Area) of 138 or less.
TPSA is the topological polar surface area, which is the area value of the polar portion of the molecular surface.
Generally, from the viewpoint of being compatible with the polymer solution in which a solvent of low polarity such as normal hexane or cyclohexane is used and promoting the reaction with the metal residue in the polymer solution, the metal residue removing agent of the present embodiment has a TPSA of 138 or less, preferably 115 or less, more preferably 90 or less, even more preferably 80 or less, and still more preferably 70 or less.
On the other hand, from the viewpoint of strongly interacting with metal atoms in metal residues, the metal residue remover of the present embodiment has a TPSA of preferably 1 or more, more preferably 21 or more, even more preferably 24 or more, still more preferably 33 or more, and still more preferably 41 or more.
TPSA can be controlled to fall within the above-mentioned range by adjusting the type and number of polar functional groups that constitute the metal residue remover of this embodiment.

(polar functional group)
The metal residue remover of the present embodiment is preferably an organic compound having at least two polar functional groups, from the viewpoint of strongly interacting with metal atoms in the metal residue.
The polar functional group is not limited to the following, as long as it is generally recognized in the field of metal residue removers used in polymer solutions, and examples thereof include a hydroxy group, a carbonyl group, an ether group, a primary amino group, a secondary amino group, a tertiary amino group, an imino group, a carboxyl group, a cyano group, a boryl group, a mercapto group, a thiocarbonyl group, a thioether group, a sulfoxide group, a sulfone group, a phosphino group, and a phosphine oxide group.

From the viewpoint of strongly interacting with the metal atoms in the metal residue, it is preferable that at least one of the polar functional groups in the metal residue remover of this embodiment is selected from the group consisting of a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group.
From the viewpoint of strong interaction with metal atoms, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, or a primary amino group is more preferred, in that order.
From the viewpoint of increasing polarity, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group), in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are preferred, in that order.

From the viewpoint of achieving an excellent balance between the strength of interaction with metal atoms in metal residues and polarity, the metal residue remover of the present embodiment preferably has one functional group 1 and one functional group 2, wherein the functional group 1 is any one selected from the group consisting of a hydroxy group (excluding hydroxy groups in carboxyl groups), a carbonyl group (excluding carbonyl groups in carboxyl groups), an ether group (excluding ether groups in ester groups), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group, and the functional group 2 is any one selected from the group consisting of a hydroxy group (excluding hydroxy groups in carboxyl groups), a carbonyl group (excluding carbonyl groups in carboxyl groups), an ether group (excluding ether groups in ester groups), a secondary amino group, and an imino group.
From the viewpoint of strong interaction with metal atoms, the functional group 1 is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, and a primary amino group are more preferred, in that order.
From the viewpoint of increasing polarity, the functional group 1 is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group) in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are more preferred in that order.
From the viewpoint of strong interaction with metal atoms, the functional group 2 is preferably a hydroxy group (excluding a hydroxy group in a carboxyl group), a carbonyl group (excluding a carbonyl group in a carboxyl group), an ether group (excluding an ether group in an ester group), a secondary amino group, or an imino group, in that order.
From the viewpoint of increasing polarity, the functional group 2 is preferably, in this order, a hydroxy group (excluding a hydroxy group in a carboxyl group), a secondary amino group, a carbonyl group (excluding a carbonyl group in a carboxyl group), an imino group, and an ether group (excluding an ether group in an ester group).

Furthermore, from the viewpoint of achieving an excellent balance between the strength of interaction with metal atoms in metal residues and polarity, the metal residue remover of this embodiment has one each of functional group 1 and functional group 2, wherein functional group 1 is any one selected from the group consisting of a hydroxy group (excluding hydroxy groups in carboxyl groups), a carbonyl group (excluding carbonyl groups in carboxyl groups), an ether group (excluding ether groups in ester groups), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group, and functional group 2 is any one selected from the group consisting of a carbonyl group (excluding carbonyl groups in carboxyl groups), an ether group (excluding ether groups in ester groups), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group. It is preferable that the functional group 1 and the functional group 2 are any one selected from the group consisting of a ter group (excluding an ether group in an ester group), a secondary amino group, and an imino group. Furthermore, from the viewpoint of reactivity with metal atoms in metal residues, when all of the functional group 1 and the functional group 2 are any one selected from the group consisting of a hydroxy group (excluding a hydroxy group in a carboxyl group) and an ether group (excluding an ether group in an ester group), it is preferable that there are three or more atoms other than O atoms between any O atom contained in the functional group 1 and the functional group 2 and any other O atom.
From the viewpoint of strong interaction with metal atoms, the functional group 1 is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, and a primary amino group are more preferred, in that order.
From the viewpoint of increasing polarity, the functional group 1 is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group) in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are more preferred in that order.
From the viewpoint of strong interaction with metal atoms, the functional group 2 is preferably a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), a secondary amino group, or an imino group, in that order.
From the viewpoint of increasing polarity, the functional group 2 is preferably, in this order, a secondary amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, and an ether group (excluding the ether group in an ester group).

Furthermore, from the viewpoint of achieving an excellent balance between the strength of interaction with metal atoms in metal residues and polarity, the metal residue remover of the present embodiment is a metal residue remover having three or more functional groups 1, and it is preferable that the functional groups 1 are at least one type of functional group selected from the group consisting of a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group.
From the viewpoint of strong interaction with metal atoms, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, or a primary amino group is more preferred, in that order.
From the viewpoint of increasing polarity, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group), in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are preferred, in that order.
The three or more functional groups 1 may be of one type alone or of two or more types.

Furthermore, from the viewpoint of achieving an excellent balance between the strength of interaction with metal atoms in metal residues and polarity, the metal residue remover of the present embodiment is a metal residue remover having three functional groups 1, and it is preferable that the functional group 1 is at least one type of functional group selected from the group consisting of a hydroxy group (excluding a hydroxy group in a carboxyl group), a carbonyl group (excluding a carbonyl group in a carboxyl group), an ether group (excluding an ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group.
From the viewpoint of strong interaction with metal atoms, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, or a primary amino group is more preferred, in that order.
From the viewpoint of increasing polarity, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group), in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are preferred, in that order.
The metal residue removing agent of the present embodiment is a metal residue removing agent having three functional groups 1, wherein the functional group 1 is at least one functional group selected from the group consisting of a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group, and when all of the three functional groups 1 are selected from the group consisting of a hydroxy group (excluding the hydroxy group in a carboxyl group) and an ether group (excluding the ether group in an ester group), it is preferable that there be three or more atoms other than O atoms between any O atom contained in the functional group 1 and any other O atom. In other words, it is preferable that there be three or more atoms other than O atoms between all pairs obtained by arbitrarily selecting two O atoms from the functional group 1.
Specifically, diethylene glycol and glycerol do not have three or more atoms other than O atoms between any two O atoms, and trimethylolmethane has three or more atoms other than O atoms between any two O atoms.
The three functional groups 1 may be of one type alone or of two or more types.

Furthermore, from the viewpoint of achieving an excellent balance between the strength of interaction with metal atoms in metal residues and polarity, the metal residue remover of the present embodiment is a metal residue remover having four or more functional groups 1, and it is preferable that the functional groups 1 are at least one type of functional group selected from the group consisting of a hydroxy group (excluding a hydroxy group in a carboxyl group), a carbonyl group (excluding a carbonyl group in a carboxyl group), an ether group (excluding an ether group in an ester group), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group.
From the viewpoint of strong interaction with metal atoms, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), a carbonyl group (excluding the carbonyl group in a carboxyl group), an ether group (excluding the ether group in an ester group), an amino group, or an imino group, in that order. Among amino groups, a tertiary amino group, a secondary amino group, or a primary amino group is more preferred, in that order.
From the viewpoint of increasing polarity, the polar functional group is preferably a hydroxy group (excluding the hydroxy group in a carboxyl group), an amino group, a carbonyl group (excluding the carbonyl group in a carboxyl group), an imino group, or an ether group (excluding the ether group in an ester group), in that order. Among amino groups, a primary amino group, a secondary amino group, and a tertiary amino group are preferred, in that order.
The four or more functional groups 1 may be of one type alone or of two or more types.

(Characteristics of metal residue remover)
As described above, the metal residue remover of this embodiment forms a complex with the metal residue when added to a polymer solution containing the metal residue.
From the viewpoint of efficiently removing metal residues from a polymer solution, for example, when the polymer solution contains titanium constituting a hydrogenation catalyst, by adding the metal residue removing agent of this embodiment in a molar ratio (metal residue removing agent/titanium) of 10 relative to the titanium constituting the hydrogenation catalyst, it is preferable to form complexes with 36 mass % or more of the total titanium in the polymer solution, more preferably form complexes with 50 mass % or more of the titanium, even more preferably form complexes with 60 mass % or more of the titanium, and even more preferably form complexes with 70 mass % or more of the titanium.
By adjusting the type, number, and positional relationship of the polar functional groups constituting the metal residue remover and adjusting the TPSA to 138 or less, the ability to form a complex with titanium is improved, and the above numerical range can be achieved.

(Suitable Structure of Metal Residue Remover)
From the viewpoint of efficiently removing metal residues in a polymer solution, the metal residue remover of the present embodiment is preferably an organic compound having a structure represented by the following formula (I), formula (II), or formula (III):

 

In formula (I), R ¹ is any one selected from the group consisting of C(R ³ ) ₂ OH, C(R ³ )═O, hydrogen, an alkyl group containing 1 to 3 carbon atoms, and an alkoxy group containing 1 to 3 carbon atoms.
Among these, from the viewpoint of achieving an excellent balance between the strength of interaction with the metal atoms in the metal residue and polarity, R ¹ is preferably any one of C(R ³ ) ₂ OH, C(R ³ )═O, hydrogen, an alkyl group containing 1 to 2 carbon atoms, and an alkoxy group containing 1 to 2 carbon atoms, more preferably any one of C(R ³ ) ₂ OH, C(R ³ )═O, hydrogen, an alkyl group containing 1 carbon atom, and an alkoxy group containing 1 carbon atom, and even more preferably C(R ³ ) ₂ OH.
^R2 is any one selected from the group consisting of C( ^R3 ) _2OH and C( ^R3 )=O.
Among these, from the viewpoint of achieving an excellent balance between the strength of the interaction with the metal atoms in the metal residue and the polarity, ^R2 is preferably either hydrogen or an alkyl group containing 1 to 3 carbon atoms, more preferably either hydrogen or an alkyl group containing 1 to 2 carbon atoms, and even more preferably either hydrogen or an alkyl group containing 1 carbon atom.
Each ^R3 is independently any one selected from the group consisting of hydrogen and an alkyl group containing 1 to 3 carbon atoms.
Among these, from the viewpoint of excellent polarity balance, ^R3 is preferably either hydrogen or an alkyl group containing 1 to 3 carbon atoms, more preferably either hydrogen or an alkyl group containing 1 to 2 carbon atoms, and even more preferably either hydrogen or an alkyl group containing 1 carbon atom.
Metal residue removers that have a structure in which these polar functional groups are present in such a number and positional relationship tend to be able to strongly interact with the metal atoms in the metal residue, and by forming a highly polar metal complex, tend to be able to more efficiently remove metal residue.

 

In formula (II), R ⁴ is any one selected from the group consisting of hydrogen and alkyl groups containing 1 to 3 carbon atoms.
Among these, from the viewpoint of achieving a good balance between the strength of the interaction with the metal atoms in the metal residue and polarity, ^R4 is preferably either hydrogen or an alkyl group containing 1 to 2 carbon atoms, and from the viewpoint of easy handling, ^R4 is preferably an alkyl group containing 1 to 3 carbon atoms, more preferably an alkyl group containing 1 to 2 carbon atoms, and even more preferably an alkyl group containing 2 carbon atoms.
Metal residue removers that have a structure in which these polar functional groups are present in such a number and positional relationship tend to be able to strongly interact with the metal atoms in the metal residue, and by forming a highly polar metal complex, tend to be able to more efficiently remove metal residue.

 

In formula (III), each R ⁵ is independently an alkylene group containing 1 to 4 carbon atoms.
Among these, from the viewpoint of achieving an excellent balance between the strength of interaction with the metal atoms in the metal residue and polarity, ^R5 is preferably an alkylene group containing 1 to 3 carbon atoms, more preferably an alkylene group containing 2 to 3 carbon atoms, even more preferably an alkylene group containing 2 carbon atoms, and still more preferably an ethylene group.
Metal residue removers that have a structure in which these polar functional groups are present in such a number and positional relationship tend to be able to strongly interact with the metal atoms in the metal residue, and by forming a highly polar metal complex, tend to be able to more efficiently remove metal residue.

(Molecular weight of metal residue remover)
From the viewpoint of ease of handling and economic efficiency, the molecular weight of the metal residue removing agent of the present embodiment is preferably 250 or less, more preferably 200 or less, even more preferably 170 or less, and even more preferably 150 or less.

[Polymer solution]
As described above, the metal residue remover of this embodiment forms a complex with the metal residue when added to a polymer solution containing the metal residue.
The polymer solution to which the metal residue remover of the present embodiment is added is not particularly limited as long as it is one that is commonly used in the field in which the metal residue remover is applied, and examples thereof include solutions containing the following polymers and solvents.

(polymer)
The polymer constituting the polymer solution to which the metal residue removing agent of the present embodiment is added is not particularly limited as long as it is one that is generally used in the field in which the metal residue removing agent is applied. For example, polymers obtained by polymerizing various compounds in the presence of a polymerization initiator, polymers obtained by hydrogenating various monomer units in the presence of a hydrogenation catalyst, and polymers obtained by chemical modification such as denaturation can be used.
Specific examples include conjugated diene polymers, hydrogenated conjugated diene polymers, olefin polymers, cyclic olefin polymers, and hydrogenated cyclic olefin polymers.
Among these, conjugated diene polymers are preferred, and hydrogenated conjugated diene polymers are more preferred, since the polymer solutions are generally easy to handle.

<Conjugated Diene Polymer>
The conjugated diene polymer is preferably a polymer containing a vinyl aromatic monomer unit and a conjugated diene monomer unit.

[Conjugated diene compounds]
The conjugated diene monomer units constituting the conjugated diene polymer are formed by polymerizing a conjugated diene compound.
Examples of the conjugated diene compound include, but are not limited to, conjugated diene compounds containing 4 to 15 carbon atoms, such as 1,3-butadiene, isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene, phenylbutadiene, α-farnesene, β-farnesene, and 1,3,7-octatriene.
Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of economy.

[Vinyl aromatic compounds]
The vinyl aromatic monomer units constituting the conjugated diene polymer are formed by polymerizing a vinyl aromatic compound.
Examples of vinyl aromatic compounds include, but are not limited to, styrene, styrenes substituted with alkyl groups such as α-methylstyrene, p-methylstyrene, and p-tert-butylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, 2-vinylpyridine, 4-vinylpyridine, vinylnaphthalene, and vinyl allyl compounds such as vinylnaphthalenes substituted with alkyl groups.
Among these, styrene is preferred from the viewpoint of economy.

[Polymerization initiator]
The polymerization initiator used in the production of the polymer is not particularly limited, and examples thereof include organic alkali metal compounds such as aliphatic hydrocarbon alkali metal compounds, aromatic hydrocarbon alkali metal compounds, and organic amino alkali metal compounds, which are generally known to have anionic polymerization activity for vinyl aromatic compounds and conjugated dienes.
The organic alkali metal compound is not limited to the following, but is preferably an aliphatic or aromatic hydrocarbon lithium compound having 1 to 20 carbon atoms, and examples thereof include compounds containing one lithium atom per molecule, dilithium compounds containing multiple lithium atoms per molecule, trilithium compounds, tetralithium compounds, and multilithium compounds. Specific examples include n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, n-hexyllithium, benzyllithium, phenyllithium, tolyllithium, a reaction product of diisopropenylbenzene with sec-butyllithium, and a reaction product of divinylbenzene with sec-butyllithium and a small amount of 1,3-butadiene.
The amount of such a polymerization initiator used can be any amount commonly used in the field of polymer production, and can be adjusted appropriately depending on the molecular weight of the target polymer.

<Hydrogenated conjugated diene polymer>
The hydrogenated conjugated diene polymer is preferably a polymer obtained by hydrogenating the conjugated diene polymer using a hydrogenation catalyst.

[Hydrogenation catalyst]
The hydrogenation catalyst is not particularly limited, and examples thereof include known catalysts: (1) supported heterogeneous hydrogenation catalysts in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like; (2) so-called Ziegler-type hydrogenation catalysts in which a transition metal salt such as an organic acid salt or an acetylacetone salt of Ni, Co, Fe, Cr, or the like is used with a reducing agent such as an organoaluminum; and (3) homogeneous hydrogenation catalysts such as so-called organometallic complexes of organometallic compounds such as Ti, Ru, Rh, Zr, or the like.
Specific examples include the hydrogenation catalysts described in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, and 2-9041.
Suitable hydrogenation catalysts include titanocene compounds, nickel-based Ziegler-type hydrogenation catalysts, cobalt-based Ziegler-type hydrogenation catalysts, and mixtures thereof.

Examples of the titanocene compound include, but are not limited to, compounds described in JP-A-8-109219. Specific examples include compounds having at least one ligand having a (substituted) cyclopentadienyl skeleton, an indenyl skeleton, or a fluorenyl skeleton, such as biscyclopentadienyltitanium dichloride and monopentamethylcyclopentadienyltitanium trichloride, and compounds obtained by reducing these titanocene compounds with a reducing organic compound.
Examples of the reducing organic compound include, but are not limited to, organic alkali metal compounds such as organolithium compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

The nickel-based Ziegler hydrogenation catalyst includes a catalyst containing a nickel compound and an organoaluminum compound. Examples of the nickel compound include, but are not limited to, nickel acetate, nickel propionate, nickel butanoate, nickel valerate, nickel hexanoate, nickel octanoate, nickel 2-ethylhexanoate, nickel decanoate, nickel neodecanoate, nickel benzoate, nickel naphthoate, nickel acetylacetonate, and nickel dibenzoylmethanate. Examples of the organoaluminum compound include, but are not limited to, trimethylaluminum, triethylaluminum, and triisobutylaluminum.

The cobalt-based Ziegler hydrogenation catalyst includes a catalyst containing a cobalt compound and organoaluminum. Examples of the cobalt compound include, but are not limited to, cobalt acetate, cobalt propionate, cobalt butanoate, cobalt valerate, cobalt hexanoate, cobalt octanoate, cobalt 2-ethylhexanoate, cobalt decanoate, cobalt neodecanoate, cobalt benzoate, cobalt naphthoate, cobalt acetylacetonate, and cobalt dibenzoylmethanate. Examples of the organoaluminum include, but are not limited to, trimethylaluminum, triethylaluminum, and triisobutylaluminum.

(metal residue)
The metal residue contained in the polymer solution to which the metal residue remover of this embodiment is added is preferably at least one selected from the group consisting of alkali metals, alkaline earth metals, transition metals, and earth metals.
In the production of polymers, compounds commonly used as polymerization initiators, hydrogenation catalysts, and reducing agents for hydrogenation catalysts contain lithium, nickel, cobalt, titanium, aluminum, and the like, and therefore the metal residue is preferably one of these metals. In particular, compounds commonly used as hydrogenation catalysts contain nickel, cobalt, and titanium, and therefore the metal residue is more preferably one of these metals. In particular, compounds used as highly active hydrogenation catalysts contain titanium, and therefore the metal residue is even more preferably titanium. Furthermore, from the viewpoint of producing a polymer solution with a small amount of metal residue, the metal residue contained in the polymer solution to which the metal residue remover of this embodiment is added is even more preferably lithium or titanium.

(solvent)
The solvent of the polymer solution to which the metal residue removing agent of the present embodiment is added is not particularly limited as long as it is one that is commonly used in the field of polymer production, and examples thereof include aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclohexane, cycloheptane, and methylcycloheptane; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.
From the viewpoint of polymer solubility and economic efficiency, cyclohexane, normal hexane, methylcyclohexane, or a mixture thereof is preferred.
In order to extract the metal residue into the aqueous layer, the solvent must have low polarity and be immiscible with water. From the viewpoint of separability from water, the solvent for the polymer solution is preferably cyclohexane, normal hexane, methylcyclohexane, or a mixture thereof.
From the viewpoint of economy, cyclohexane, normal hexane, or a mixture thereof is more preferred.

[Metal residue remover system]
The metal residue removing agent system of this embodiment contains the metal residue removing agent of this embodiment described above and a surfactant.
By using the metal residue remover system of this embodiment, metal residues in a polymer solution can be efficiently removed.

(Surfactant)
The surfactant used in the metal residue remover system of this embodiment is not particularly limited as long as it is a surfactant that is commonly used, but examples thereof include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. These surfactants may be used singly or in combination of two or more.

Anionic surfactants include, but are not limited to, carboxylic acid types such as aliphatic carboxylates and polyoxyethylene alkyl ether carboxylates; sulfonic acid types such as alkanesulfonates and alkylbenzenesulfonates; sulfate esters such as alkyl sulfates and polyoxyethylene alkyl ether sulfates; and phosphate ester types such as alkyl phosphates and polyoxyethylene alkyl ether phosphates. These may also be used in the form of free acids.

Furthermore, polymeric anionic surfactants can be used as anionic surfactants. Examples of polymeric anionic surfactants include, but are not limited to, polycarboxylic acids and their salts; sulfonic acid group-containing polymers and their salts; and other anionic polymers such as carboxymethyl cellulose, sodium alginate, and rosin soap. Examples of polycarboxylic acids and their salts include, but are not limited to, (meth)acrylic acid polymers and their salts; polymers of unsaturated dibasic acids such as maleic anhydride, maleic acid, fumaric acid, and itaconic acid, or copolymers with other monomers and their salts. Examples of sulfonic acid group-containing polymers include, but are not limited to, lignin sulfonic acid, formalin condensates of naphthalene (or alkylnaphthalene) sulfonic acid, formalin condensates of benzene (or alkylbenzene) sulfonic acid, formalin condensates of aromatic sulfonic acids such as formalin condensates of creosote oil sulfonates, and vinyl sulfonic acid polymers.

Examples of cationic surfactants include, but are not limited to, alkylamine salt types such as monoalkylamine salts, dialkylamine salts, and trialkylamine salts; quaternary ammonium salt types such as alkyltrimethylammonium halides, dialkyldimethylammonium halides, and alkylbenzalkonium chloride; and the like.

Nonionic surfactants include, but are not limited to, ester types such as glycerin fatty acid esters and sorbitan fatty acid esters; ether types such as polyoxyethylene alkyl ethers and polyoxyethylene alkylphenyl ethers; ester ether types such as fatty acid polyethylene glycols and fatty acid polyoxyethylene sorbitan; and alkanolamide types such as fatty acid alkanolamides.

Amphoteric surfactants include, but are not limited to, carboxybetaine types such as alkylbetaine and fatty acid amidopropyl betaine; 2-alkylimidazoline derivative types such as 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine; glycine types such as alkyldiethylenetriaminoacetic acid; and amine oxide types such as alkylamine oxide.

From the viewpoint of metal residue removal efficiency, anionic surfactants are preferred as surfactants. From the viewpoint of metal residue removal efficiency, aliphatic carboxylic acids, polycarboxylates, and polyoxyethylene alkyl ether phosphates are preferred as anionic surfactants. Of these, aliphatic carboxylic acids having 8 to 18 carbon atoms are more preferred.

<Aliphatic carboxylic acid>
From the viewpoints of economy and ease of handling, the aliphatic carboxylic acid is preferably an aliphatic carboxylic acid having 8 to 18 carbon atoms. Specific examples include, but are not limited to, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, palmitoleic acid, oleic acid, and linoleic acid. These may be used alone or in combination of two or more.

<Polycarboxylate>
From the viewpoints of economy and ease of handling, the polycarboxylate is preferably a sodium salt of an olefin-maleic acid copolymer or a sodium salt of a styrene-maleic acid copolymer. Specific examples include, but are not limited to, Polystar OM, OMR, A-1060, and SMX-1H manufactured by NOF Corporation, and XIRAN 2000HNa, 3000HNa, 3500HNa, and 3600HNa manufactured by Polyscope Polymers BV. These may be used alone or in combination of two or more.

<Polyoxyethylene alkyl ether phosphate calcium salt>
From the viewpoints of economy and ease of handling, the polyoxyethylene alkyl ether phosphate is preferably a polyoxyethylene alkyl ether calcium phosphate. Specific examples include, but are not limited to, ADEKACOL PS-440E, PS-810E, and PS-807 manufactured by ADEKA CORPORATION, and Phosphanol RB-410, RD-510Y, RL-310, RS-610, and RS-710 manufactured by Toho Chemical Industry Co., Ltd. These may be used alone or in combination of two or more.

[Method for producing hydrogenated conjugated diene polymer]
The method for producing a hydrogenated conjugated diene polymer of this embodiment includes the steps of:
The method includes Step 1 of obtaining a conjugated diene polymer in the presence of a polymerization initiator and hydrogenating the conjugated diene polymer in the presence of a hydrogenation catalyst to obtain a hydrogenated conjugated diene polymer solution; Step 2 of mixing the hydrogenated conjugated diene polymer solution with the metal residue removing agent of the present embodiment described above to obtain a complex; and Step 3 of separating the complex to separate and recover the hydrogenated conjugated diene polymer.

(Process 1)
In the method for producing a hydrogenated conjugated diene polymer of this embodiment, step 1 is a step of obtaining a hydrogenated conjugated diene polymer solution, which comprises a polymerization reaction to obtain a conjugated diene polymer in the presence of a polymerization initiator and a hydrogenation reaction of the conjugated diene polymer in the presence of a hydrogenation catalyst.

<Polymerization reaction>
As a method for polymerizing a conjugated diene polymer using an organic alkali metal compound as a polymerization initiator, a conventionally known method can be applied.
Although not particularly limited, for example, batch polymerization, continuous polymerization, or a combination thereof may be used.
The polymerization temperature is preferably 0°C to 180°C, more preferably 30°C to 150°C.
The polymerization time varies depending on the conditions, but is usually within 48 hours, preferably 0.1 to 10 hours.
The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas.
The polymerization pressure is not particularly limited as long as it is set within a pressure range that allows the monomer and solvent to be maintained in a liquid phase within the above temperature range.
Furthermore, it is preferable to take care to prevent impurities such as water, oxygen, carbon dioxide gas, etc. that may inactivate the catalyst and living polymer from being mixed into the polymerization system.

Furthermore, at the end of the polymerization reaction step, a required amount of a bifunctional or higher functional coupling agent may be added to carry out a coupling reaction.
As the bifunctional coupling agent, conventionally known ones can be used, and examples thereof include, but are not limited to, alkoxysilane compounds such as trimethoxysilane, triethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dichlorodimethoxysilane, dichlorodiethoxysilane, trichloromethoxysilane, and trichloroethoxysilane; dihalogen compounds such as dichloroethane, dibromoethane, dimethyldichlorosilane, and dimethyldibromosilane; and acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalate esters.
Furthermore, the tri- or higher functional polyfunctional coupling agent can be a conventionally known one, and is not particularly limited. Examples include polyhydric epoxy compounds such as tri- or higher hydric polyalcohols, epoxidized soybean oil, diglycidyl bisphenol A, and 1,3-bis(N-N'-diglycidylaminomethyl)cyclohexane; halogenated silicon compounds represented by the general formula R _4-n SiX _n (where R is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen, and n is an integer of 3 to 4), such as methylsilyl trichloride, t-butylsilyl trichloride, silicon tetrachloride, and bromides thereof; and halogenated tin compounds represented by the general formula R _4-n SnX _n (where R is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen, and n is an integer of 3 to 4), such as methyltin trichloride, t-butyltin trichloride, and tin tetrachloride. Dimethyl carbonate, diethyl carbonate, and the like may also be used.

<Denaturation reaction>
In the method for producing a hydrogenated conjugated diene copolymer according to the present embodiment, a modified conjugated diene copolymer having an atomic group bonded thereto may be obtained. The atomic group having a functional group is preferably bonded as a step preceding the hydrogenation step described below.

The "atomic group having a functional group" is not limited to the following, but examples include atomic groups containing at least one functional group selected from the group consisting of hydroxyl, carboxyl, carbonyl, thiocarbonyl, acid halide, acid anhydride, carboxylic acid, thiocarboxylic acid, aldehyde, thioaldehyde, carboxylic ester, amide, sulfonic acid, sulfonate, phosphate, phosphate ester, amino, imino, nitrile, pyridyl, quinoline, epoxy, thioepoxy, sulfide, isocyanate, isothiocyanate, silicon halide, silanol, alkoxysilicon, tin halide, boronic acid, boron-containing, boronate salt group, alkoxytin, and phenyltin. Atomic groups containing at least one functional group selected from the group consisting of hydroxyl, epoxy, amino, silanol, and alkoxysilane are particularly preferred.

The "atomic group having a functional group" can be formed by using a modifying agent.
Examples of the modifying agent include, but are not limited to, tetraglycidyl meta-xylylene diamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, ε-caprolactone, δ-valerolactone, 4-methoxybenzophenone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, and N-methylpyrrolidone.

The modified conjugated diene polymer is not particularly limited, but can be obtained, for example, by anionic living polymerization using a polymerization initiator having a functional group or an unsaturated monomer having a functional group, or by addition reaction of a modifier that forms or contains a functional group at the living end.
As another method, the polymer can be obtained by reacting a conjugated diene polymer with an organic alkali metal compound such as an organolithium compound (metallation reaction), and then adding a modifier having a functional group to the conjugated diene polymer to which the organic alkali metal compound has been added.
In the case of a method using a metalation reaction, a modified hydrogenated conjugated diene copolymer can also be produced by obtaining a hydrogenated conjugated diene polymer, subjecting the polymer to a metalation reaction, and then reacting the polymer with a modifier.
The temperature at which the modification reaction is carried out is preferably 0 to 150° C., more preferably 20 to 120° C. The time required for the modification reaction varies depending on other conditions, but is preferably within 24 hours, more preferably 0.1 to 10 hours.
In such a modified conjugated diene polymer, the modified conjugated diene polymer may contain a part of an unmodified conjugated diene polymer mixed therein.

The modified conjugated diene copolymer may be a secondarily modified conjugated diene copolymer obtained by reacting the modified conjugated diene copolymer with a secondarily modifying agent reactive with the functional groups of the modified conjugated diene copolymer.
Examples of the secondary modifying agent include, but are not limited to, a modifying agent having a functional group selected from a carboxyl group, an acid anhydride group, an isocyanate group, an epoxy group, a silanol group, and an alkoxysilane group, and the secondary modifying agent has at least two functional groups selected from these functional groups.
However, when the functional group of the secondary modifier is an acid anhydride group, the secondary modifier may have one acid anhydride group. When the secondary modifier is reacted with the modified conjugated diene copolymer as described above, the amount of the secondary modifier used is preferably 0.3 to 10 mol, more preferably 0.4 to 5 mol, and even more preferably 0.5 to 4 mol per equivalent of the functional group bonded to the modified conjugated diene copolymer.
The method for reacting the modified conjugated diene copolymer with the secondary modifier is not particularly limited and may be any known method. For example, the melt-kneading method described below, or a method in which each component is dissolved or dispersed and mixed in a solvent or the like and reacted, etc. are included. Note that these secondary modifications are preferably carried out after the hydrogenation step.
Examples of secondary modifying agents include, but are not limited to, maleic anhydride, pyromellitic anhydride, 1,2,4,5-benzenetetracarboxylic dianhydride, toluylene diisocyanate, tetraglycidyl-1,3-bisaminomethylcyclohexane, and bis-(3-triethoxysilylpropyl)-tetrasulfane.

In addition, in the method for producing a hydrogenated conjugated diene copolymer according to this embodiment, a modified conjugated diene copolymer graft-modified with an α,β-unsaturated carboxylic acid or a derivative thereof, such as an anhydride, ester, amidation, or imidation product thereof, may be obtained in step 1. Examples of α,β-unsaturated carboxylic acids or derivatives thereof include, but are not limited to, maleic anhydride, maleic anhydride imide, acrylic acid or its ester, methacrylic acid or its ester, and endo-cis-bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid or its anhydride. The amount of α,β-unsaturated carboxylic acid or its derivative added is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the hydrogenated conjugated diene copolymer. The reaction temperature for graft modification is preferably 100 to 300°C, more preferably 120 to 280°C. The graft modification method is not limited to the following, but for example, the method described in JP-A-62-79211 can be applied.

<Hydrogenation reaction>
In the method for producing a hydrogenated conjugated diene polymer of this embodiment, the above-described non-hydrogenated unmodified or modified conjugated diene polymer is obtained, and then the non-hydrogenated unmodified or modified conjugated diene polymer is subjected to a hydrogenation reaction using the above-described hydrogenation catalyst to obtain a hydrogenated conjugated diene polymer.
The hydrogenation reaction temperature is generally preferably in the range of 0 to 200°C, more preferably in the range of 30 to 150°C.
The pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and even more preferably 0.3 to 5 MPa.
The hydrogenation reaction time is usually preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours.
The hydrogenation reaction may be a batch process, a continuous process, or a combination thereof.
In the method for producing the hydrogenated conjugated diene polymer of this embodiment, various stabilizers such as phenol-based stabilizers, phosphorus-based stabilizers, sulfur-based stabilizers, and amine-based stabilizers may be added.

(Step 2)
In the method for producing a hydrogenated conjugated diene polymer of this embodiment, step 2 is a step of mixing the metal residue removing agent of this embodiment with a hydrogenated conjugated diene polymer solution.
In step 2, the metal residue contained in the hydrogenated conjugated diene polymer solution obtained in step 1 is brought into sufficient contact with the metal residue remover of the present embodiment to obtain a complex, which makes it easier to separate the metal residue in step 3 described below.
As described above, the metal residue removing agent of the present embodiment forms a complex with metal residues and has a TPSA of not more than 138. From the viewpoint of efficiently removing metal residues in a polymer solution, it is preferable that the agent have the various structures described above.
The mixing time of the metal residue removing agent and the hydrogenated conjugated diene polymer solution is preferably 10 seconds or longer, more preferably 1 minute or longer, even more preferably 5 minutes or longer, and even more preferably 30 minutes or longer, from the viewpoint of efficiently removing metal residues in the hydrogenated conjugated diene polymer solution.
The mixing temperature is preferably 20 to 90°C, more preferably 30 to 80°C, and even more preferably 40 to 70°C, from the viewpoint of efficiently removing metal residues in the hydrogenated conjugated diene polymer solution.

From the viewpoint of ease of handling, the metal residue removing agent may be liquefied by dissolving or melting it in a solvent, etc., and then added to the hydrogenated conjugated diene polymer solution. For example, by dissolving a solid metal residue removing agent in a solvent, it can be handled as a solution, and by dissolving a liquid metal residue removing agent in a solvent, it can be handled as a solution with reduced viscosity.
The solvent for dissolving the metal residue remover is not particularly limited as long as it is a commonly used solvent, and examples thereof include water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, dimethylformamide, dimethyl sulfoxide, acetonitrile, acetone, methyl ethyl ketone, tetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, chloroform, dichloromethane, carbon disulfide, diethyl ether, n-propyl ether, n-butyl ether, benzene, toluene, o-xylene, m-xylene, p-xylene, cyclohexane, normal hexane, and mixed solvents thereof.

In the step 2, the surfactant may be added.
The surfactant is preferably added in an amount of 0 to 0.5 parts by mass relative to 100 parts by mass of the hydrogenated conjugated diene polymer. From the viewpoint of improving the compatibility of the metal residue remover with the hydrogenated conjugated diene polymer solution, the amount is preferably 0.001 parts by mass or more, and more preferably 0.01 parts by mass or more. On the other hand, from the viewpoints of economy and suppressing the residue of aliphatic carboxylic acids in the polymer product, the amount is preferably 0.3 parts by mass or less, and more preferably 0.1 parts by mass or less.

As surfactants, anionic surfactants are preferred from the viewpoint of metal residue removal efficiency. As anionic surfactants, aliphatic carboxylic acids, polycarboxylates, and polyoxyethylene alkyl ether phosphates are preferred from the viewpoint of metal residue removal efficiency. As aliphatic carboxylic acids, aliphatic carboxylic acids having 8 to 18 carbon atoms are preferred from the viewpoints of economy and ease of handling. As polycarboxylates, sodium salts of olefin-maleic acid copolymers and sodium salts of styrene-maleic acid copolymers are preferred. As polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl ether calcium phosphates are preferred. Of these, aliphatic carboxylic acids having 8 to 18 carbon atoms are more preferred.

In step 2, the metal residue remover of this embodiment is preferably added in an amount of 0.001 to 10 parts by mass per 100 parts by mass of the hydrogenated conjugated diene polymer solution. From the viewpoint of more efficient removal of metal residues, 0.003 parts by mass or more is preferred, 0.01 parts by mass or more is more preferred, 0.03 parts by mass or more is even more preferred, and 0.1 parts by mass or more is even more preferred. On the other hand, from the viewpoints of economy and low residue in the polymer, 8 parts by mass or less is preferred, 3 parts by mass or less is more preferred, 1 part by mass or less is more preferred, and 0.5 parts by mass or less is even more preferred.

(Step 3)
In the method for producing a hydrogenated conjugated diene polymer of this embodiment, step 3 is a step of separating the complex obtained in step 2 to separate and recover a hydrogenated conjugated diene polymer.
In step 3, the metal residue contained in the hydrogenated conjugated diene polymer solution is separated, and the hydrogenated conjugated diene polymer from which the metal residue has been removed is recovered.

The method for separating the complex is not particularly limited, as long as it is one commonly used in this field, but examples include extraction into an aqueous layer, extraction into an alcohol layer, adsorption onto a porous solid, filtration, and sedimentation. Of these, extraction into an aqueous layer is preferred due to its economical advantages.

In the method for producing a hydrogenated conjugated diene polymer according to this embodiment, removal of the metal residue is finally completed by separating the hydrogenated conjugated diene polymer from the aqueous phase. The method for separating the hydrogenated conjugated diene polymer from the aqueous phase is not particularly limited as long as it is a method commonly used in the art. Examples of the method include: removing the aqueous phase from a mixture of a hydrogenated conjugated diene polymer solution and an aqueous phase by static separation, centrifugation, countercurrent extraction, or the like, and then drying the hydrogenated conjugated diene polymer solution to recover the hydrogenated conjugated diene polymer; precipitating and recovering the hydrogenated conjugated diene polymer by adding a polar solvent that is a poor solvent for the hydrogenated conjugated diene polymer solution, such as acetone or alcohol; pouring the hydrogenated conjugated diene polymer solution into boiling water with stirring and removing the solvent by steam stripping; and directly heating the hydrogenated conjugated diene polymer solution to remove the solvent.
From the viewpoint of economy, the method of removing the solvent by steam stripping and the method of directly heating the hydrogenated conjugated diene polymer solution to distill off the solvent are preferred, and the method of removing the solvent by steam stripping is more preferred.

[Hydrogenated conjugated diene polymer composition]
The hydrogenated conjugated diene polymer composition of the present embodiment contains a hydrogenated conjugated diene polymer, metal residue, and the metal residue removing agent of the present embodiment, and the content of the metal residue removing agent is 0.1 to 100 ppm.
From the viewpoint of reducing the amount of metal residue added and achieving excellent economy, the content of the metal residue remover is preferably 50 ppm or less, more preferably 30 ppm or less, even more preferably 10 ppm or less, and even more preferably 5 ppm or less.
By adding a metal residue remover, the amount of metal residue can be effectively reduced, and the metal residue forms a complex with the metal residue remover, which effectively reduces the change in the b value of the molded body before and after heating and the haze value of the molded body.
The b value and haze value of the sheet-shaped molded article of the hydrogenated conjugated diene polymer of this embodiment before and after heating can be measured by the methods described in the Examples below.

The present invention will be explained in detail below based on examples, but the present invention is not limited to these.

[Preparation of hydrogenation catalyst]
In the examples and comparative examples described later, the hydrogenation catalyst used in producing the hydrogenated conjugated diene polymer was prepared by the following method.

(Preparation Example 1)
<Preparation of hydrogenation catalyst A>
A reaction vessel equipped with a stirrer was purged with nitrogen and charged with 1 L of dried and purified cyclohexane. Next, 100 mmol of bis(η5-cyclopentadienyl)titanium dichloride was added. While stirring thoroughly, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the mixture was allowed to react at room temperature for approximately 3 days. This yielded hydrogenation catalyst A.

(Preparation Example 2)
<Preparation of hydrogenation catalyst B>
A reaction vessel equipped with a stirrer was purged with nitrogen and charged with 1 L of dried and purified cyclohexane. Next, a cyclohexane solution of nickel (II) 2-ethylhexanoate (100 mmol in terms of Ni) was added. While stirring thoroughly, a cyclohexane solution containing 300 mmol of triethylaluminum was added over 10 minutes, and the mixture was allowed to react at room temperature for 30 minutes. This yielded hydrogenation catalyst B.

(Preparation Example 3)
<Preparation of hydrogenation catalyst C>
A reaction vessel equipped with a stirrer was purged with nitrogen and charged with 1 L of dried and purified cyclohexane. Next, a cyclohexane solution of cobalt (II) neodecanoate (100 mmol in terms of Co) was added. While thoroughly stirring, a cyclohexane solution containing 300 mmol of triethylaluminum was added over 10 minutes, and the mixture was allowed to react at room temperature for 30 minutes. This yielded hydrogenation catalyst C.

[Preparation of polymer solution]
(Production Example 1)
<Preparation of Polymer Solution 1>
Batch polymerization was carried out in the following manner using a 100 L tank reactor equipped with a stirrer and a jacket.
First, 45 kg of cyclohexane was charged into a reactor, and the temperature was adjusted to 55°C. After that, the total amount of butadiene monomer and styrene monomer (hereinafter referred to as total monomers) to be charged into the reactor was 8,000 g, which was 100 parts by mass, and 0.150 parts by mass of n-butyllithium (hereinafter also referred to as "nBL") and 0.4 moles of N,N,N',N'-tetramethylethylenediamine (hereinafter also referred to as "TMEDA") per mole of nBL were added.
Next, 15 parts by mass of styrene was added over 5 minutes, and the mixture was then allowed to react for a further 15 minutes.
Next, a cyclohexane solution (concentration: 40% by mass) containing 70 parts by mass of butadiene was continuously added to the reactor at a constant rate over 30 minutes, and then the reaction was continued for another 15 minutes.
Next, 15 parts by mass of styrene was added over 5 minutes, and the mixture was then allowed to react for a further 15 minutes.
Three minutes after the reaction temperature reached the maximum temperature of 85°C, 1.0 mole of methanol was added per mole of nBL to terminate the polymerization reaction, thereby obtaining a cyclohexane solution (polymer solution 1) having a conjugated diene polymer concentration of 15 mass%.
The amount of metal contained in the obtained polymer was measured by elemental analysis using inductively coupled plasma (ICP). The measurement results of the content concentration of metal residue in the polymer are shown in Table 1 below.

(Production Example 2)
<Preparation of Polymer Solution 2>
To the polymer solution 1 obtained in Production Example 1, the hydrogenation catalyst A was added in an amount of 100 ppm in terms of titanium per 100 parts by mass of the conjugated diene polymer, and a hydrogenation reaction was carried out for 45 minutes at a hydrogen pressure of 0.9 MPa and a temperature of 90°C, thereby obtaining a cyclohexane solution (polymer solution 2) having a hydrogenated conjugated diene polymer concentration of 15% by mass.
The amount of metal contained in the obtained polymer was measured by elemental analysis using ICP. The measurement results of the content concentration of metal residue in the polymer are shown in Table 1.

(Production Example 3)
<Preparation of Polymer Solution 3>
The hydrogenation catalyst A was changed to hydrogenation catalyst B, and 600 ppm of nickel was added. The hydrogenation reaction was carried out at a hydrogen pressure of 0.98 MPa and a temperature of 75°C for 480 minutes under the same conditions as in (Production Example 2), to obtain polymer solution 3.
The amount of metal contained in the obtained polymer was measured by elemental analysis using ICP. The measurement results of the content concentration of metal residue in the polymer are shown in Table 1.

(Production Example 4)
<Preparation of Polymer Solution 4>
The hydrogenation catalyst A was changed to hydrogenation catalyst C, 600 ppm of cobalt was added, and the hydrogenation reaction was carried out at a hydrogen pressure of 2.0 MPa and a temperature of 150°C for 600 minutes under the same conditions as in (Production Example 2), to obtain polymer solution 4.
The amount of metal contained in the obtained polymer was measured by elemental analysis using ICP. The measurement results of the content concentration of metal residue in the polymer are shown in Table 1.

(Production Example 5)
<Preparation of Polymer Solution 5>
The cyclohexane initially charged was changed to a mixed solvent containing 90% by mass of cyclohexane and 10% by mass of n-hexane, and the other conditions were the same as in (Production Example 1), to obtain a polymer solution 5'.
Polymer solution 5 was obtained by changing polymer solution 1 to polymer solution 5', and the other conditions were the same as in (Production Example 2).
The amount of metal contained in the obtained polymer was measured by elemental analysis using ICP. The measurement results of the content concentration of metal residue in the polymer are shown in Table 1.

(Production Example 6)
<Production of Polymer 6>
The amount of hydrogenation catalyst A was changed to 20 ppm in terms of titanium per 100 parts by mass of the conjugated diene polymer, the hydrogen pressure during the hydrogenation reaction was changed to 1.5 MPa, the temperature to 50°C, and the time to 240 minutes, but the other conditions were the same as in (Production Example 2), and polymer solution 6 was obtained.
Using a 10 L tank reactor equipped with a stirrer and a jacket, Polymer 6 was produced by the following method.
5000 g of polymer solution 6 was placed in a 10-liter reactor and heated to 50° C. with stirring. Subsequently, 3.7 mmol (0.10 parts by mass relative to 100 parts by mass of the polymer) of lauric acid was added to the polymer solution, and the mixture was stirred at 50° C. for 5 minutes. Thereafter, 150 g of ultrapure water was added, and the mixture was stirred at 50° C. for 30 minutes to obtain a polymer solution.
A 10 L vessel equipped with a stirrer was charged with 5 kg of hot water at 95°C, and 50 g of the mixed solution of the polymer solution and ultrapure water obtained as described above was added thereto over a period of 5 minutes, thereby carrying out steam stripping.
After stirring for 10 minutes, the aggregated polymer crumbs were collected, and then the polymer crumbs were dehydrated and vacuum dried to remove the water, thereby obtaining Polymer 6.
The amount of metal contained in the obtained polymer was measured by elemental analysis using ICP. The measurement results of the content concentration of metal residue in the polymer are shown in Table 1.

[Examples A1 to A29, Comparative Examples A1 to A2: Metal Residue Remover]
The metal residue removers used in the examples and comparative examples described below are shown below.
The numbers in brackets [ ] following the compound names indicate that the compounds are compounds that can be represented by the above formulas (I) to (III).
Compound 1: Ethylene glycol Compound 2: 1,3-propanediol Compound 3: 3-amino-1-propanol Compound 4: 3-(methylamino)-1-propanol Compound 5: 2-(dimethylamino)ethanol Compound 6: 3-(dimethylamino)-1-propanol Compound 7: Ethylene glycol monomethyl ether Compound 8: Hydroxyacetone [(I)]
Compound 9: Methyl glycolate [(I)]
Compound 10: Diacetyl [(I)]
Compound 11: Glyoxal [(I)]
Compound 12: 1,3-dihydroxyacetone [(I)]
Compound 13: Diethylene glycol Compound 14: Glycerol Compound 15: 3-methoxy-1,2-propanediol Compound 16: 1,2,3-cyclohexanetriol Compound 17: 1,2,6-hexanetriol Compound 18: Diethanolamine Compound 19: 3-(dimethylamino)-1,2-propanediol Compound 20: 1-monoacetin Compound 21: Trimethylolmethane [(II)]
Compound 22: Trimethylolethane [(II)]
Compound 23: Trimethylolpropane [(II)]
Compound 24: Triethylene glycol Compound 25: N-(3-aminopropyl)diethanolamine Compound 26: N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine Compound 27: Triethanolamine [(III)]
Compound 28: Diethyl 2-hydroxymalonate Compound 29: Diethyl ketomalonate Compound 30: Ethylenediaminetetraacetic acid Compound 31: N-hydroxyethylethylenediaminetriacetic acid

[Characteristics of metal residue remover]
The properties of Compounds 1 to 31, such as TPSA, polar functional group, minimum inter-O atom distance, and molecular weight, are shown in Tables 2 to 4.
The TPSA calculated from the structure of the compound is shown in the TPSA row.
In the polar functional group row, if the compound has any of a hydroxy group (excluding hydroxy groups in carboxyl groups), a carbonyl group (excluding carbonyl groups in carboxyl groups), an ether group (excluding ether groups in ester groups), a primary amino group, a secondary amino group, a tertiary amino group, and an imino group, it is represented as a hydroxy group, a carbonyl group, an ether group, a primary amino group, a secondary amino group, a tertiary amino group, and an imino group, respectively. If the compound contains multiple polar functional groups of the same type, the same number of groups are represented.
In the row of the minimum inter-O atom distance, when the polar functional group contains only a hydroxy group (excluding a hydroxy group in a carboxyl group) or an ether group (excluding an ether group in an ester group), the smallest value among the number of atoms other than O atoms between two O atoms is shown.
The molecular weight column lists the molecular weight of the compound.

[Preparation of polymer solution using metal residue remover]
Example 1
Using a 10 L tank reactor equipped with a stirrer and a jacket, metal residues were removed from the polymer solution by the following method.
5000 g of the polymer solution 2 obtained in the above (Production Example 2) was placed in a 10 liter reactor and heated to 50° C. with stirring.
Subsequently, 35 mmol of Compound 1 was added as a metal residue remover, and the mixture was stirred for 5 minutes at 50° C. After that, 150 g of ultrapure water was added, and the mixture was stirred for 30 minutes at 50° C. to obtain a polymer solution.
A 10 L vessel equipped with a stirrer was charged with 5 kg of hot water at 95°C, and 50 g of the mixed solution of the polymer solution and ultrapure water obtained as described above was added thereto over a period of 5 minutes, thereby carrying out steam stripping.
After stirring for 10 minutes, the aggregated polymer crumbs were collected, and then the polymer crumbs were dehydrated and vacuum dried to remove the water.
The amount of metal residue in the polymer obtained after drying was measured by ICP, and the removal rate (%) of metal residue in the polymer was calculated.
The calculated results of the removal rate (%) of metal residue in the polymer are shown in Table 5.

Examples 2 to 145
Polymers were obtained under the same conditions as in Example 1, except that the types of polymer solutions and metal residue removers in Example 1 were changed as shown in Tables 5 to 19.
The amount of metal residue in the resulting polymer was measured by ICP, and the removal rate (%) of metal residue in the polymer was calculated.
The calculated results of the removal rate (%) of metal residue in the polymer are shown in Tables 5 to 19.

 

Examples 146 to 174
The type of polymer solution and the type of metal residue removing agent in Example 1 were changed as shown in Tables 20 to 22, the polymer solution was placed in a reactor, and heated to 50°C with stirring. Then, before the metal residue removing agent was added, 3.7 mmol (0.10 parts by mass relative to 100 parts by mass of the polymer) of lauric acid, which is an aliphatic carboxylic acid, was added as a surfactant to the polymer solution. The other conditions were the same as in Example 1 to obtain a polymer.
The amount of metal residue in the resulting polymer was measured by ICP, and the removal rate (%) of metal residue in the polymer was calculated.
The calculation results of the metal residue removal rate (%) in the polymer are shown in Tables 20 to 22.

Examples 175 to 184
The type of polymer solution and the type of metal residue removing agent in Example 1 were changed as shown in Tables 23 and 24, and simultaneously with the addition of ultrapure water, the surfactants shown in Tables 23 and 24 were added in the amounts shown in Tables 23 and 24. Polymers were obtained under the same conditions as in Example 1.
In Tables 23 and 24, surfactant A represents a polyoxyethylene alkyl ether calcium phosphate (Phosphanol RL-310, manufactured by Toho Chemical Industry Co., Ltd.), and surfactant B represents a sodium salt of styrene-maleic acid copolymer (XIRAN3500HNa, manufactured by Polyscope Polymers BV).
The amount of metal residue in the resulting polymer was measured by ICP, and the removal rate (%) of metal residue in the polymer was calculated.
The calculated results of the removal rate (%) of metal residue in the polymer are shown in Tables 23 and 24.

Comparative Examples 1 and 2
A polymer was obtained in the same manner as in Example 1, except that the type of polymer solution and the type of metal residue remover in Example 1 were changed as shown in Table 25.
The amount of metal residue in the resulting polymer was measured by ICP, and the removal rate (%) of metal residue in the polymer was calculated.
The calculated results of the removal rate (%) of metal residue in the polymer are shown in Table 25.

[Examples 185 to 192, Comparative Examples 3 and 4]
The polymers described in the Examples and Comparative Examples in Table 26 were molded into sheets having a thickness of 2 mm, and the change in b value and haze upon heating were measured as follows.
The measurement results obtained are shown in Table 26.

(Measurement of change in b value upon heating)
The hydrogenated conjugated diene polymer was compression molded to prepare a sheet-like molded product having a thickness of 2 mm, which was used as a measurement sample.
The b value of the sheet-like molded product was measured using a color difference meter (SM-T45 manufactured by Suga Test Instruments Co., Ltd.).
The sheet-like molded product was heated in an air atmosphere at 100° C. for 120 minutes, and then cooled to room temperature, and the b value was measured in the same manner.
The change in b value was calculated by subtracting the b value of the sheet-form molding before heating from the b value of the sheet-form molding after heating, and the evaluation was made according to the value as follows.
◎: Less than 8 〇: 8 or more but less than 10 △: 10 or more but less than 15 ×: 15 or more

(Haze measurement)
The hydrogenated conjugated diene polymer was compression molded to prepare a sheet-like molded product having a thickness of 2 mm, which was used as a measurement sample.
The haze (%) of the sheet-like molded body was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH-8000), and the haze was evaluated as follows according to the measured value.
◎: Less than 9 〇: 9 or more but less than 12 △: 12 or more but less than 15 ×: 15 or more

This application is based on a Japanese patent application (patent application No. 2024-018631) filed with the Japan Patent Office on February 9, 2024, the contents of which are incorporated herein by reference.

The metal residue remover for polymer solutions and the method for producing polymers using the same of the present invention have industrial applicability as a method for removing catalyst residues remaining in polymer solutions.

Claims (29)

A metal residue remover that forms a complex with a metal residue when added to a polymer solution containing the metal residue,
TPSA (Topological Polar Surface Area) is 138 or less;
Metal residue remover. an organic compound having at least two polar functional groups;
The metal residue remover according to claim 1 . one of the at least two polar functional groups
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to claim 2. A metal residue remover having one each of the following functional group 1 and the following functional group 2,
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The functional group 2 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
a secondary amino group, and an imino group;
The metal residue remover according to claim 1 . A metal residue remover having one each of the following functional group 1 and the following functional group 2,
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is any one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The functional group 2 is
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
is selected from the group consisting of a secondary amino group and an imino group;
When the functional group 1 and the functional group 2 are all any one selected from the group consisting of a hydroxy group (excluding a hydroxy group in a carboxyl group) and an ether group (excluding an ether group in an ester group), there are three or more atoms other than O atoms between any O atom contained in the functional group 1 and the functional group 2 and any other O atom.
The metal residue remover according to claim 1 . A metal residue remover having three or more of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to claim 1 . A metal residue remover having three of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
When all of the three functional groups 1 are selected from the group consisting of hydroxy groups (excluding hydroxy groups in carboxyl groups) and ether groups (excluding ether groups in ester groups), there are three or more atoms other than O atoms between any O atom contained in the functional group 1 and any other O atom.
The metal residue remover according to claim 1 . A metal residue remover having four or more of the following functional groups 1:
The functional group 1 is
Hydroxy groups (excluding hydroxy groups in carboxyl groups),
carbonyl group (excluding the carbonyl group in a carboxyl group),
ether groups (excluding ether groups in ester groups);
at least one functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imino group;
The metal residue remover according to claim 1 . The metal residue is at least one selected from the group consisting of alkali metals, alkaline earth metals, transition metals, and earth metals.
The metal residue remover according to claim 1 . The metal residue is at least one selected from the group consisting of lithium, nickel, cobalt, titanium, and aluminum.
The metal residue remover according to claim 1 . The metal residue is at least one selected from the group consisting of nickel, cobalt, and titanium.
The metal residue remover according to claim 1 . The metal residue is at least one selected from the group consisting of lithium and titanium.
The metal residue remover according to claim 1 . The metal residue is titanium.
The metal residue remover according to claim 1 . The polymer solution is a conjugated diene-based polymer solution.
The metal residue remover according to claim 1 . The polymer solution is a hydrogenated conjugated diene-based polymer solution.
The metal residue remover according to claim 1 . the solvent of the polymer solution is any one selected from the group consisting of cyclohexane, normal hexane, methylcyclohexane, and mixtures thereof;
The metal residue remover according to claim 1 . the metal residue is titanium originating from a hydrogenation catalyst,
the metal residue removing agent is added in an amount of 10 in a molar ratio relative to the titanium constituting the hydrogenation catalyst in the polymer solution, thereby forming a complex with titanium that accounts for 36 mass % or more of the total titanium in the polymer solution;
The metal residue remover according to claim 1 . The metal residue remover has a structure shown in formula (I):
The metal residue remover according to claim 1 .
(In formula (I), R ¹ is any one selected from the group consisting of C(R ³ ) ₂ OH, C(R ³ )═O, hydrogen, an alkyl group containing 1 to 3 carbon atoms, and an alkoxy group containing 1 to 3 carbon atoms;
^R2 is any one selected from the group consisting of C( ^R3 ) _2OH and C( ^R3 )=O;
Each ^R3 is independently selected from the group consisting of hydrogen and an alkyl group containing 1 to 3 carbon atoms. The metal residue remover has a structure shown in formula (II):
The metal residue remover according to claim 1 .
(In formula (II), ^R4 is any one selected from the group consisting of hydrogen and alkyl groups containing 1 to 3 carbon atoms.) The metal residue remover has a structure shown in formula (III):
The metal residue remover according to claim 1 .
(In formula (III), each ^R5 is independently an alkylene group containing 1 to 4 carbon atoms.) The molecular weight of the metal residue removing agent is 250 or less.
The metal residue remover according to claim 1 . The metal residue remover according to any one of claims 1 to 21,
A surfactant,
containing
Metal residue remover system. The surfactant is an aliphatic carboxylic acid having 8 to 18 carbon atoms.
23. The metal residue remover system of claim 22. Step 1: obtaining a conjugated diene polymer in the presence of a polymerization initiator, and hydrogenating the conjugated diene polymer in the presence of a hydrogenation catalyst to obtain a hydrogenated conjugated diene polymer solution;
a step 2 of mixing the metal residue removing agent according to any one of claims 1 to 21 with the hydrogenated conjugated diene polymer solution to obtain a complex;
and a step 3 of separating the complex to separate and recover the hydrogenated conjugated diene polymer.
A method for producing a hydrogenated conjugated diene polymer. In the step 2, a surfactant is mixed in an amount of 0.5 parts by mass or less relative to 100 parts by mass of the hydrogenated conjugated diene-based polymer.
The method for producing the hydrogenated conjugated diene polymer according to claim 24. The surfactant is an aliphatic carboxylic acid having 8 to 18 carbon atoms.
The method for producing the hydrogenated conjugated diene polymer according to claim 25. The method for separating the complex in step 3 is extraction into an aqueous layer.
The method for producing the hydrogenated conjugated diene polymer according to claim 25. In the step 2, the metal residue removing agent is added in an amount of 0.001 to 10 parts by mass per 100 parts by mass of the hydrogenated conjugated diene polymer solution.
The method for producing the hydrogenated conjugated diene polymer according to claim 24. A method for removing metal residue comprising the steps of: removing a hydrogenated conjugated diene polymer; removing metal residue; and removing the metal residue remover according to claim 1.
The content of the metal residue remover is 0.1 to 100 ppm.
Hydrogenated conjugated diene polymer composition.