JP2002241493A - Bromination method of aromatic polymeric compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for brominating an aromatic polymeric compound relatively hard to undergo an electrophilic substitution reaction with a high yield under mild conditions. SOLUTION: The bromination method of an aromatic polymeric compound comprises reacting N-bromosuccinimide with an aromatic polymeric compound represented by general formula (1) (wherein -Z- is -SO2- or -CO-; x and y are each 0.01-0.99, the sum of x and y being 1; and -Ar- is an optionally hetero-atom- containing 4-18C aromatic divalent group and may have a substituent) in the presence of a strong acid in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for brominating an aromatic polymer compound.

[0002]

2. Description of the Related Art Brominated aromatic polymer compounds are:
Similar to the brominated compound of a low-molecular-weight aromatic compound, since a bromo group as a substituent can be relatively easily converted to various other substituents, an intermediate such as an ion-exchange resin, a flame retardant, an ion It is useful as an intermediate for conductive polymers, electrically conductive polymers, insulating materials, and the like. Conventionally, as a method for brominating an aromatic polymer compound, for example, a method using bromine as a bromination reagent is known (for example, Polymer, 1989, Vol. 30, June, 1137-).
1142.). However, in the method using bromine as such a bromination reagent, it is not easy to bromide an aromatic polymer compound having low activity in an electrophilic substitution reaction. There are industrial problems such as requiring time or high temperature conditions.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for brominating an aromatic polymer compound which is relatively insensitive to an electrophilic substitution reaction with a good yield under mild conditions. .

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, the N-bromosuccinimide was allowed to act relatively in an organic solvent in the presence of a strong acid. The present inventors have found that even an aromatic polymer compound which is less susceptible to an electrophilic substitution reaction can be brominated with a good yield under mild conditions, and have completed the present invention.

That is, the present invention relates to a compound represented by the general formula (1): (Wherein, -Z- is -SO ₂ - represents or -CO-, x
And y represent 0.01 to 0.99, respectively, the sum of x and y is 1, and -Ar- is an aromatic divalent group having 4 to 18 carbon atoms which may contain a hetero element. And -Ar- may have a substituent. The present invention provides an industrially excellent method for brominating an aromatic polymer compound characterized by allowing N-bromosuccinimide to act on the aromatic polymer compound represented by the formula (1). The aromatic polymer compound represented by the general formula (1) may be a random copolymer, an alternating copolymer, or a block copolymer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
According to the method for brominating an aromatic polymer compound of the present invention, the bromination does not proceed at all by a conventionally known method,
Alternatively, even in the case of an aromatic polymer compound in which bromination proceeds only under strong conditions, bromination can be performed with a high yield under relatively mild conditions.

The objects of bromination in the present invention include:
For example, an aromatic polymer compound represented by the formula (1) may be mentioned.

In the formula, the divalent group represented by -Z- is -SO
Represents _2- or -CO-. x and y mean the molar ratio of the comonomer used in synthesizing the copolymer in the copolymer, and represent 0.01 to 0.99, respectively, and the sum of x and y is 1. -Ar- represents an aromatic divalent group which may contain a hetero element having 4 to 18 carbon atoms, and may have a substituent. In many cases, the -Ar- moiety is more susceptible to electrophilic substitution than the diphenylsulfone or benzophenone moiety, so that a larger y facilitates obtaining a copolymer having a higher degree of bromination as a whole. Generally, y can be adjusted in the range of 0.1 to 0.9 to adjust various physical properties of the copolymer to a desired range.

-Ar- represents an aromatic divalent group which may contain a hetero element having 4 to 18 carbon atoms.
r- may have a substituent.

Examples of the substituent which -Ar- may have include, for example, the following, but the number of substituents is allowable as long as bromination is not hindered. A straight-chain or branched alkyl group which may be substituted with a hydroxyl group or a halogen atom, such as a methyl group, an ethyl group, a 2-propyl group, a t-butyl group, a hydroxymethyl group, and a trifluoromethyl group; a methoxy group Linear or branched alkoxy groups which may be substituted with a halogen atom, such as, ethoxy, trifluoromethoxy, etc .; phenyl, methylphenyl, methoxyphenyl, biphenyl, phenoxyphenyl, chlorophenyl , Such as a sulfophenyl group, an alkyl group, an alkoxy group, a phenyl group,
A phenyl group optionally substituted with a phenoxy group, a halogen atom or a sulfo group; a phenoxy optionally substituted with an alkyl group such as a phenoxy group, a methylphenoxy group, a methoxyphenoxy group, a sulfophenoxy group, an alkoxy group or a sulfo group Alkyloxycarbonyl groups such as ethoxycarbonyl groups; alkylcarbonyloxy groups such as ethylcarbonyloxy groups; aminocarboxy groups or N-alkylaminocarboxy groups; and nitrogen atoms such as amino groups and dimethylamino groups substituted with alkyl groups An optionally substituted amino group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom (to the extent that it can be further brominated) and an iodine atom; a ureido group; an acylamino group;
Carboxyl group; hydroxy group; cyano group; sulfo group;
And an aminosulfonyl group.

Representative examples of -Ar- include, for example, the following divalent groups. o-phenylene group, m-
Phenylene group, p-phenylene group, naphthalene-1,4
-Diyl group, naphthalene-1,5-diyl group, naphthalene-2,6-diyl group, naphthalene-2,3-diyl group, biphenyl-4,4'-diyl group, biphenyl-
3,3′-diyl group, p-terphenyl-4,4 ″ -diyl group, 2,2-diphenylpropane-4 ′, 4 ″ -diyl group, fluorene-2,2′-diyl group, fluorene Hydrocarbon divalent groups such as -3,3'-diyl group, carbazole-2,2'-diyl group, carbazole-3,
3'-diyl group, thiophen-2,5-diyl group, dibenzothiophen-2,5-diyl group, furan-2,5-
Diyl group, dibenzofuran-2,2'-diyl group, dibenzofuran-3,3'-diyl group, diphenylamine-
Divalent groups containing a hetero atom such as 4,4'-diyl group and diphenylether-4,4'-diyl group;

Typical examples of -Ar- having a substituent include biphenyl-2,5-diyl, N-ethylcarbazole-2,2'-diyl, and N-ethylcarbazole-3,3'-diyl. Group, 3,3'-diphenylbiphenyl-4,4'-diyl group, 3,3'-bisphenoxybiphenyl-4,4'-diyl group, (3,3'-diphenyl) diphenylether-4,4'- Diyl group, (3
3'-bisphenoxy) diphenyl ether-4,4'-
And a diyl group and a diphenyl ether-2,5-diyl group.

Among them, -Ar- is preferably a phenylene group which may be substituted or a biphenyldiyl group which may be substituted, and m-phenylene group, p-
A phenylene group, a biphenyl-4,4'-diyl group and a biphenyl-3,3'-diyl group are particularly preferred.

The aromatic polymer compound of the formula (1) may be a random copolymer, an alternating copolymer or a block copolymer. A ratio and a polymerization method are selected, and a copolymer can be obtained according to a known method.

The bromination method of the present invention is characterized in that N-bromosuccinimide is allowed to act on an aromatic polymer compound represented by the general formula (1) in an organic solvent in the presence of a strong acid. However, as the strong acid used here, mineral acids such as sulfuric acid and hydrochloric acid, and trifluoroacetic acid are preferable, and among them, sulfuric acid is particularly preferable. As the organic solvent used here, halogenated methanes or halogenated ethanes are preferable. Here, the halogenated methanes mean a group of compounds in which one to four of the four hydrogen atoms of methane are substituted with halogen atoms. The same meaning applies to halogenated ethanes. As the organic solvent to be used, methylene chloride or chloroform is particularly preferable. In selecting an organic solvent, it is preferable that the solubility of the aromatic polymer compound used is as high as possible. The ratio of the strong acid to the organic solvent is such that the organic solvent is added to 1 part by weight of strong acid.
The amount is preferably 3 to 20 parts by weight, and usually 5 to 10 parts by weight of the organic solvent is preferably used for 1 part by weight of the strong acid.
Mixing can be performed in an arbitrary order, and a method in which an aromatic polymer compound and N-bromosuccinimide which is a brominating reagent are added to a premixed place may be used. A method in which a strong acid, for example, sulfuric acid is gradually added to an organic solvent solution or slurry of the reagent is preferable.

The reaction temperature of the bromination depends on the nature of the aromatic polymer compound as a substrate, but is usually from 0 ° C. to 30 ° C.
It is preferable to carry out in the range of. When sulfuric acid is used as the strong acid, if the reaction temperature is too high, the sulfonation reaction may proceed. In general, when a large amount of bromination reagent is used, the degree of bromination increases. However, the bromination yield (the yield of bromine consumed by reacting with the aromatic polymer compound relative to the amount of bromine used). ) Depends on the properties of the aromatic polymer compound as a substrate. As a method for removing and purifying the brominated aromatic polymer compound, an ordinary method can be used. For example, a brominated aromatic polymer compound is precipitated by adding a poor solvent, and the target product is taken out by filtration or the like, followed by washing with water or reprecipitation purification using a good solvent and a poor solvent. It can be carried out.

The degree of bromination of the aromatic polymer compound is N
It can be determined by ordinary means such as MR measurement and organic element analysis.

[0018]

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

Embodiment 1 A random copolymer of the above structural formula (4,4′-dichlorodiphenylsulfone, 4,4′-dihydroxydiphenylsulfone, 4,4′-biphenol) is placed in a 500 ml four-necked flask equipped with a mechanical stirrer by a known method. 15.0 g (obtained by copolymerization) (10.1 mmol of a unit derived from 4,4'-biphenol) and 3.62 g (20.3 mmol) of N-bromosuccinimide were added, and dissolved in 200 ml of methylene chloride under a nitrogen atmosphere. Under ice-cooling, 20.0 g of concentrated sulfuric acid 30
When the solution was dropped over a period of minutes, a precipitate was formed in the middle and eventually became a laver-like mass. After dropping, add 3 drops under ice-cooling.
After stirring for an hour, the reaction mixture was poured into ice, a small amount of sodium sulfite was added, and the mixture was stirred. After neutralization with an aqueous solution of sodium hydroxide, the solution was concentrated under reduced pressure with an evaporator, and the resulting slurry was filtered by suction. The precipitate obtained was washed repeatedly with water and dried under reduced pressure. Part of the polymer is chloroform /
After reprecipitation purification with methanol, elemental analysis revealed that
B per one unit derived from 4,4'-biphenol
It was found that r substituted about 1.8. Elemental analysis: C: 58.0% H: 3.2% S: 11.0% Br: 8.5% 1.8 Br calculated: C: 59.1% H: 3.2% S: 11.2% Br: 8.8%

Embodiment 2 In a 500 ml four-necked flask equipped with a mechanical stirrer, 15.0 g of an alternating copolymer of the above structural formula (obtained by copolymerization of 4,4′-dichlorodiphenyl sulfone, 4,4′-biphenol by a known method) ( 37.5 mmol of a unit derived from 4,4′-biphenol), 35.0 g (197 mmol) of N-bromosuccinimide, and 202 g of methylene chloride,
The mixture was stirred under a nitrogen atmosphere. To this suspension, 99.6 g of concentrated sulfuric acid was added dropwise over 75 minutes under ice-cooling, and a laver-like product was precipitated in the middle. After completion of the dropwise addition, the mixture was stirred under ice-cooling for one and a half hours, then, the reaction mixture was poured into ice, and a small amount of sodium sulfite was added and stirred. The precipitate obtained by concentrating under reduced pressure with an evaporator and forming an aqueous slurry by suction filtration was repeatedly washed with water while performing a neutralization operation, and then dried under reduced pressure. Elemental analysis of the resulting polymer showed that
It was found that about 2.1 units of Br were substituted for one unit derived from 4'-biphenol. Elemental analysis: C: 46.7% H: 2.6% S: 5.4% Br: 29.1% 2.1 Br calculated: C: 50.9% H: 2.5% S: 5.6% Br: 29.6%

[0021]

According to the bromination method of the present invention, an aromatic polymer compound can be brominated smoothly and in good yield under milder conditions than the conventionally known method.

Claims (4)

[Claims] 1. A compound of the formula (1) in an organic solvent in the presence of a strong acid (Wherein, -Z- is -SO ₂ - represents or -CO-, x
And y represent 0.01 to 0.99, respectively, the sum of x and y is 1, and -Ar- is an aromatic divalent group having 4 to 18 carbon atoms which may contain a hetero element. And -Ar- may have a substituent. A method for brominating an aromatic polymer compound, wherein N-bromosuccinimide is allowed to act on the aromatic polymer compound represented by the formula (1). 2. An aromatic polymer compound (1) comprising -A
The method according to claim 1, wherein r- is a phenylene group which may have a substituent or a biphenyldiyl group which may have a substituent. 3. The method according to claim 1, wherein the strong acid is sulfuric acid. 4. The method according to claim 1, wherein the organic solvent contains at least one selected from halogenated methanes and halogenated ethanes.