JP3371323B2 - Method for sulfonating aromatic polymer - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for sulfonation of aromatic polymers.

[0002]

2. Description of the Related Art Sulfonation of aromatic polymers is carried out by adjusting the amounts of the raw material to be sulfonated and the sulfonating agent.

However, in the same step, since the aromatic polymer is generally insoluble in water, the sulfonation reaction is carried out by dissolving it in a solvent.

Therefore, after sulfonation of the aromatic polymer, water is added to the reaction system to dissolve the sulfonated product,
Next, it is common to recover and remove the solvent from the same system. For example, JP-A-63-189404 and JP-A-2-2
In Japanese Patent No. 58802, static separation by batch processing is performed, and in Japanese Patent Laid-Open No. 6-298852, continuous static separation is performed by providing an average residence time of a predetermined time. In JP-A-8-895, water-solvent separation by heating distillation is performed,
Each has been proposed.

[0005]

In the above-mentioned sulfonation reaction, the reaction rate extremely decreases when water is contained in the system. Therefore, in order to reuse the solvent for the reaction, the water must be completely removed. Is a necessary condition.

However, in the above-mentioned technique, for example, static separation, the sulfonated product of the aromatic polymer, which is a reaction product, acts as a surfactant, and the boundary between the water layer and the solvent layer becomes unclear, and separation becomes difficult. . Further, in the solvent recovery by distillation, since a solvent such as a chlorine-based hydrocarbon and water become an azeotropic mixture, it is difficult to completely remove water from the solvent,
A purification / dehydration step of the recovered solvent is required.

For this reason, there are problems in that work efficiency is reduced and additional auxiliary equipment is required.

In view of the above, the present invention aims to make it possible to recover the solvent used in the sulfonation reaction of an aromatic polymer in a state of not containing water, and further to reuse the solvent to improve efficiency. The purpose is to construct a sulfonation system.

[0009]

In order to solve the above problems, the present invention provides a solvent continuously supplied with a weight average molecular weight.
The amount is added and dissolved 100,000 1,000,000 aromatic polymer performs sulfonation reaction and then supplying sulfonating agent to the solution, and separating the solid reaction product precipitated at this time and solvent, separation Sulfonation of an aromatic polymer, in which the recovered solvent is returned and used again in the sulfonation reaction .
Is the way.

In the present invention, the sulfonated product of the aromatic polymer is solidified to separate it from the solvent.
There is no need to add water to the reaction system.

Therefore, the solvent separated here does not contain water and can be returned and reused as it is.

Although any solvent can be used as the solvent, an aliphatic cyclic hydrocarbon is preferable.

On the other hand, the reaction solid matter separated from the reaction system may be dried as it is to form a sulfonated product of an aromatic polymer, or it may be dissolved in water or an aqueous alkali solution to prepare a sulfonated aromatic polymer. It may be an aqueous solution.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the aromatic polymer used as the substance to be sulfonated is, for example, polystyrene, poly-α-methylstyrene, styrene-butadiene, styrene-acrylonitrile, styrene-butadiene-acrylonitrile, styrene- ( (Meth) acrylic acid, styrene- (meth) acrylic acid ester (carbon number 1
~ 4 aliphatic hydrocarbons), styrene-acrylonitrile- (meth) acrylic acid esters (aliphatic hydrocarbons having 1 to 4 carbon atoms), styrene-butadiene- (meth) acrylic acid esters (fatty acids having 1 to 4 carbon atoms) Group hydrocarbons), styrene-maleic anhydride, styrene-itaconic anhydride, and other styrenic polymers.

Of these, preferred are styrene-butadiene, styrene-acrylonitrile, styrene-butadiene-acrylonitrile, styrene-maleic anhydride, styrene-acrylonitrile- (meth) acrylic acid ester (aliphatic hydrocarbons having 1 to 4 carbon atoms). ), Styrene-butadiene- (meth) acrylic acid ester (aliphatic hydrocarbon having 1 to 4 carbon atoms). More preferred are styrene-butadiene, styrene-acrylonitrile, styrene-butadiene-acrylonitrile, and styrene-maleic anhydride.

These copolymers may be used alone or as a mixture of a plurality of them,
It may also be used as a mixture with polystyrene or another polymer.

Examples of the polymers other than the above include polyphenylene ether, polyphenylene sulfide, polycarbonate, polyamide (so-called nylon), polyethylene terephthalate, polybutylene terephthalate and the like.

These polymers may be used alone or in combination of two or more.

As the aromatic polymer used, for example, used waste materials may be reused, facial dyes, stabilizers,
Additives such as flame retardants, plasticizers, fillers and other auxiliary agents may be included.

Further, it may be a mixture of used resin waste and new material.

The above-mentioned aromatic polymer has a molecular weight of 100.
It is preferably -50,000,000, more preferably 200-1,000,000.

Examples of the sulfonating agent include sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid and concentrated sulfuric acid, and among these, sulfuric anhydride is preferable.

These sulfonating agents may be used alone or in combination of two or more. The addition amount is preferably 0.1 to 300 mol% with respect to the aromatic unit, and more preferably 1 to 300 mol%.
It is in the range of 200 mol%.

The sulfonating agent may be used in combination with a Lewis base. Examples of the Lewis base include alkyl phosphates (triethyl phosphate, trimethyl phosphate, etc.), dioxane, acetic anhydride, ethyl acetate, ethyl palmitate, diethyl ether, thioxane and the like.

The addition amount of these Lewis bases is 0.01 to 30 with respect to the aromatic unit in the aromatic polymer.
It is preferably 0 mol%, more preferably 0.5 to
It is 100 mol%. If the amount of the Lewis base added is too small, a gelled product is likely to be generated during the sulfonation reaction, and if it is too large, the sulfonation reaction itself is difficult to proceed and the yield is lowered.

As the solvent at the time of reaction, aliphatic halogenated hydrocarbons having 1 to 2 carbon atoms (preferably 1,2-dichloroethane, chloroform, dichloromethane, 1,1-dichloroethane etc.), nitromethane, nitrobenzene, aliphatic cyclics It is a hydrocarbon (preferably cyclohexane, methylcyclohexane, cyclopentane, etc.), preferably an aliphatic cyclic hydrocarbon. This is because the aliphatic cyclic hydrocarbon easily dissolves the unreacted aromatic polymer, while the sulfonated aromatic polymer which is a reaction product does not dissolve at all, and the solvent and the reaction solid matter are removed from the slurry reaction solution. This is because it becomes easier to separate (aromatic polymer sulfonate).

These solvents may be used alone or as a mixture of two or more. In mixing in the above solvent, the mixing ratio is not particularly limited.

Alternatively, the above solvent may be mixed with another solvent. Solvents that can be mixed and used include paraffin hydrocarbons (having 1 to 7 carbon atoms), acetonitrile,
Examples thereof include carbon disulfide, tetrahydrofuran, tetrahydropyran, 1,2-dimethoxyethane, acetone, methyl ethyl ketone and thiophene. Of these, paraffinic hydrocarbons (having 1 to 1 carbon atoms) are preferable.
7), tetrahydrofuran, acetone, acetonitrile.

The mixing ratio with these other solvents is not particularly limited, but is preferably in the range of 1 to 100% by volume.

A sulfonation reaction is carried out using the above aromatic polymer, a sulfonating agent, a Lewis base and a solvent. In the present invention, the reaction solid product formed in the reaction system is neutralized before neutralizing the formed sulfonated product. And the solvent are separated, and the solvent is recovered as it is and used again in the reaction. On the other hand, the reaction solid is dried to remove the residual solvent or dissolved in water or an alkaline aqueous solution.

In this case, as the alkaline substance used in the alkaline aqueous solution, oxides, hydroxides, carbonates and acetates of alkali metals (sodium, lithium, potassium etc.) and alkaline earth metals (magnesium, calcium etc.) are used. Compounds such as sulfates and phosphates, ammonia, various (1 to 3 alkyl) amine compounds and the like are gradually added as they are or in the state of an aqueous solution to complete the neutralization treatment.

The amount of water (alkaline aqueous solution) added varies depending on the molecular weight, but is 0.5 per 1 part by weight of the polymer.
-100 parts by weight, and more preferably 1
It is from 50 to 50 parts by weight.

Next, a series of steps for sulfonating an aromatic polymer will be described with reference to FIG.

To sulfonate the aromatic polymer, the solvent is continuously supplied from the solvent tank 1 by the pump 2, and the aromatic polymer is added to and dissolved in the solvent [(a) in FIG. 1]. Alternatively, in order to sulfonate the aromatic polymer, an aromatic polymer dissolved in a solvent may be added.

At this time, the solution may or may not be heated, but it is desirable to heat it in order to improve the treatment capacity.

The time required for dissolving the aromatic polymer in the solvent is slightly affected by the temperature and concentration of the solution, the molecular weight and type of the aromatic polymer used, but is usually 10 minutes to 2 minutes.
It's time.

The concentration of the aromatic polymer solution at this time is 1 to 30% by weight when a chlorine-based solvent is used,
It is preferably 5 to 20% by weight, and when a non-chlorine-based solvent is used, it is 0.5 to 20% by weight, preferably 1 to 15% by weight.

Then, a Lewis base is injected if necessary [(b) in FIG. 1].

It is preferable to add a Lewis base in order to suppress the crosslinking reaction at the time of sulfonation. The Lewis base may be dissolved in the solvent at the same time as the above aromatic polymer. It is advantageous in terms of work efficiency to add them at the same time.

Next, the sulfonating agent is injected into the aromatic polymer solution at a mixing ratio such that the desired sulfonation rate is obtained [(c) in FIG. 1].

The temperature of the solution at this time is 0 to 100 ° C., preferably 20 to 80 ° C., although it depends on the kind of the solvent.

It is desirable that the sulfonating agent be added dropwise so that the reaction does not run away.

After the injection of the sulfonating agent, the reaction product is precipitated in the form of slurry as the reaction proceeds. The reaction time is 10 minutes to 2 hours, depending on the temperature. The deposited slurry (reaction solid) is separated from the solvent by the solid-liquid separator 3.

After completion of the reaction, it is desirable to cool the reaction solution in order to accelerate the precipitation of the slurry.

The above reaction may be carried out in the atmosphere or in an inert gas such as nitrogen, but it may be carried out under an inert gas to prevent the oxidation of the aromatic polymer. desirable.

The raw materials may be mixed in either the reaction tank or the line mixer.

The separated solvent is returned to the solvent tank 1 by the pump 4 and the like, and is returned to the original line again.

The returned solvent loss is replenished from the solvent replenishment tank 5 at any time.

Although the unreacted Lewis base and sulfonating agent are partially mixed in the solvent returned, the amount of these raw materials added becomes constant because the steady state is achieved by continuous operation.

The separated slurry is (1) heated as it is in the dryer 6 or dried by vacuum or both to be a solid aromatic sulfonate.

(2) In the dissolution tank 7, an aqueous solution of an aromatic polymer dissolved in water and having sulfonic acid introduced therein is obtained.

(3) In the dissolution tank 8, an aromatic polymer solution neutralized with an alkaline aqueous solution and introduced with a sulfonate is prepared.

As the solid-liquid separator 3 for separating the solvent and the slurry, a sedimentation separator, a filtration device (plate type, cylindrical type,
Disk type, belt type, etc., squeezing device (filter press type, tube press type, screw press type, belt press type, tower press type, disc press type, etc.), centrifuge (decanter type, screw discharge type, extrusion) (Plate type, etc.), levitation separator, cyclone, etc.

2 and 3 show a concrete example of the solid-liquid separator.

The apparatus shown in FIG. 2 has two dissolution tanks 11 each having a mesh M for filtering the slurry, which is installed in the tank.
12 are provided, and each of the dissolution tanks 11 and 12 is provided with a stirrer 13 and 14, a reaction solution supply line for supplying the reaction solution into the tanks, and a water system supply for supplying water or an alkaline aqueous solution. A line, a return line for recovering the solvent in the tank, and an aqueous solution recovery line are provided.

The reaction liquid supply line has an open / close valve 1
5 and 16, the water supply line is an open / close valve 17,
18, the return line is opened / closed by open / close valves 19 and 20, and the aqueous solution recovery line is opened / closed by open / close valves 21 and 22, respectively.

In this apparatus, one tank, for example, the melting tank 1
In 2, the opening / closing valve 16 for supplying the reaction solution is opened, the reaction solution is supplied into the tank, the reaction solid is trapped in the mesh M, and the opening / closing valve 20 is opened to return the solvent to the return line. To be done.

In the other dissolution tank 11, the reaction liquid supply line and the solvent return line, that is, the opening / closing valve 15 and the opening / closing valve 19 are closed, and the opening / closing valve 17 is opened to trap the reaction solids trapped in the mesh M. Water or an alkaline aqueous solution is injected to dissolve the water, and an aqueous solution of aromatic sulfonic acid and aromatic sulfonate is produced. This aqueous solution is recovered from the aqueous solution recovery line by opening the opening / closing valve 21.

The above operation is alternately repeated in the dissolution tank 11 and the dissolution tank 12.

On the other hand, the apparatus shown in FIG. 3 uses a triangular-pyramidal mesh S, and the reaction solution supply pipe 32 is located above the dissolution tank 31, and the solvent recovery pipe 3 is slightly projected from the bottom.
3 is provided, and the solvent recovery pipe 33 is covered with a triangular pyramid-shaped mesh S.

In this apparatus, the reaction liquid is supplied from the upper reaction liquid supply pipe 32. At this time, the reaction solid is trapped in the mesh S and gradually dropped to the lower part of the tank by gravity. The dropped reaction solid is dissolved in water and alkaline water to produce an aqueous solution of an aromatic polymer into which sulfonic acid or sulfonate has been introduced.

Further, the solvent passes through the triangular pyramid-shaped mesh S and is returned to the reaction line by the lower solvent recovery pipe 33.

By the method and apparatus described above, the solvent used in the sulfonation reaction is recovered in a water-free state without coming into contact with water, the alkaline compound, or the aqueous solution thereof. As a result, the recovered solvent can be reused as it is for the sulfonation reaction, leading to improved work efficiency, effective use of resources, and cost reduction.

[0064]

As is apparent from the above description, according to the present invention, the solvent used in the sulfonation reaction of the aromatic polymer can be reused in the reaction as it is, and the working efficiency can be improved. It is possible to improve resources, effectively use resources, and reduce costs.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining a process of sulfonating an aromatic polymer.

FIG. 2 is a schematic diagram showing an example of a solid-liquid separator.

FIG. 3 is a schematic view showing another example of a solid-liquid separator.

Continuation of front page (56) Reference JP-A-63-189406 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 6/00-6/28 C08F 8/00-8 / 50

Claims (4)

(57) [Claims] 1. A weight average molecule in a continuously supplied solvent.
The amount is added and dissolved 100,000 1,000,000 aromatic polymer performs sulfonation reaction and then supplying sulfonating agent to the solution, and separating the solid reaction product precipitated at this time and solvent, separation A sulfonation method of an aromatic polymer, characterized in that the solvent is returned and used again in the sulfonation reaction. 2. The aromatic polymer sulfonation method according to claim 1, wherein the separated reaction solid is dried as it is to obtain a sulfonated product of the aromatic polymer. 3. The sulfonated aromatic polymer according to claim 1, wherein the separated reaction solid is dissolved in water or an aqueous alkali solution to obtain an aqueous solution of a sulfonate-introduced aromatic polymer. Method. 4. The method of sulfonation of an aromatic polymer according to claim 1, wherein the solvent is an aliphatic cyclic hydrocarbon.