JPS5850648B2 - Method for producing graft polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a graft polymer, which comprises graft polymerizing a vinyl monomer to coal.

Sewage or organic wastewater is treated by various water treatment methods to prevent pollution, but the sludge generated during this process has poor dewatering properties and contains a lot of moisture, so even if it is incinerated, it requires a large amount of subsidy. Fuel is required, and it is desirable to remove as much water as possible in the dehydration process.

In recent years, sludge has been treated using various organic flocculants such as polyacrylamide, its partially hydrolyzed product, sodium polyacrylate, and polyaminoalkyl (meth)acrylate to improve dewatering properties. Although the sludge has excellent flocculation properties, the flocs tend to collapse during the subsequent treatment process, causing clogging of offshore wood.
In fact, sufficient dehydration cannot be achieved by using only these organic flocculants.

Therefore, in order to improve the drawbacks of the above-mentioned organic flocculants, water treatment agents have been proposed in which these organic flocculants are grafted onto coal.

Because this coal-grafted polymer has coal as a core and an organic flocculant grafted onto it, the flocs settle at a higher rate after flocculation and have excellent dewatering properties compared to organic flocculants alone. Since the resulting dehydrated cake contains a large amount of coal, it is self-combustible and is extremely advantageous when incinerated.

However, it is actually extremely difficult to efficiently produce a coal graft polymer with excellent cohesiveness and dehydration properties, that is, a polymer completely grafted onto coal.

That is, simply adding pulverized coal to an aqueous vinyl monomer solution does not increase the graft polymerization rate, that is, the ratio of the amount of polymer grafted to coal to the amount of vinyl monomer charged.

Conventionally, various graft polymerization methods have been proposed to increase the graft polymerization rate in a graft polymerization method in which coal is added to an aqueous vinyl monomer solution.

For example, (1) a mechanical treatment method, that is, a method in which vinyl monomer is grafted onto the surface of coal while pulverizing it; (2)
There are methods such as 3) radiation method using a catalyst.

However, although method (1) improves the graft polymerization rate somewhat, on the other hand, the molecular weight decreases due to the intense grinding energy, making it impossible to produce a graft polymer with excellent cohesiveness and dehydration properties.

In addition, although the method (2) generally produces more homopolymers and improves the polymerization rate of monomers, it has the disadvantage that the graft polymerization rate cannot be increased to that extent.

Furthermore, method (3) is highly dangerous because it involves the use of radiation, and also increases industrial equipment costs.

In view of these circumstances, the present inventors have conducted extensive research on a method for producing a coal graft polymer with an increased graft polymerization rate. As a result, the present inventors have found that by pre-treating coal to a pH of 2 or less with a hydrogen peroxide solution, As a result of learning that the graft polymerization rate can be significantly increased and conducting further research based on this knowledge, the present invention was completed.

That is, the present invention treats coal with an acidic solution having a pH of 2 or less,
The present invention relates to a method for producing a graft polymer, which comprises subsequently treating with a hydrogen peroxide solution or with a hydrogen peroxide solution having a pH of 2 or less, and grafting a vinyl monomer onto the treated product.

The coal used in the present invention is preferably pulverized.
The degree of grinding is approximately 24 meshes or less, preferably 100 meshes or less, and preferably 400 meshes or more.

According to the invention, it is in particular necessary to treat the coal with an acidic solution having a pH of 2 or less and then with a hydrogen peroxide solution, or to treat it with a hydrogen peroxide solution having a pH of 2 or less.

The acidic solution having a pH of 2 or less is preferably an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid, but may also be an organic acid such as acetic acid, formic acid or propionic acid.

Further, as the hydrogen peroxide solution having a pH of 2 or less, a mixed aqueous solution of the above acid and hydrogen peroxide is exemplified.

Regarding the method of treating coal with an acidic solution with a pH of 2 or less and then with a hydrogen peroxide solution, first of all, when treating coal with an acidic solution with a pH of 2 or less, there are no particular limitations on the treatment temperature, but the treatment For operational reasons, the temperature is 100°C or lower, preferably 20 to 80'C.

The treatment time cannot be specified because it varies slightly depending on the particle size of the coal and the treatment temperature, but approximately 2 to 6 hours is sufficient.

Next, the coal treated with the acidic solution is subjected to treatment with a hydrogen peroxide solution after washing with water or as it is.

Regarding the hydrogen peroxide solution used in the present invention, its concentration as H2O2 is preferably 10% by weight or more, preferably 20% by weight or more from the viewpoint of the graft polymerization rate.

Regarding the treatment conditions for the hydrogen peroxide solution, the treatment temperature is in the range of 10 to 60 DEG C., but below 10 DEG C., the reaction takes a long time, and when the upper limit is exceeded, the graft polymerization rate decreases significantly.

The treatment time will vary depending on the concentration of hydrogen peroxide, treatment temperature, etc., but generally 3 to 5 hours is sufficient.

By the way, in the method for treating coal of the present invention, as described above, coal may be first treated with an acidic solution and then treated with a hydrogen peroxide solution. From the viewpoint of solution stability, the present inventors recommend a method of treating coal using a hydrogen peroxide solution with a pH of 2 or less.

Regarding the conditions for treating coal with a hydrogen peroxide solution having a pH of 2 or less, the conditions for treating coal treated with an acidic solution as described above with a hydrogen peroxide solution may be followed.

Next, the treated coal is washed with water, dried if necessary,
Subjected to graft polymerization.

Regarding the drying temperature, it is desirable to set it to 50° C. or lower, and if the upper limit is exceeded, the kraft polymerization rate cannot be increased.

The graft polymerization rate can be greatly increased simply by mixing the coal treated as described above with the vinyl monomer aqueous solution described below.

The effects of this invention will now be specifically explained as follows.

Specific example 1 Contents 1. Using 100 to 300 mesh of coal 121 and the acid listed in Table 1 in an OOOwLl beaker, adjust the pH to
Add 360 g of the prepared 20% hydrogen peroxide solution, and
After stirring at 0°C for 4 hours, the mixture was washed with water and dried under reduced pressure at 20°C.

Next, 6.0 g of dimenalaminoethyl methacrylate methyl chloride salt and 34.0 g of ion-exchanged water were added to a reaction vessel having a content of 300 rnl and equipped with a stirrer, a nitrogen introduction tube, and a thermometer.
．． 9 was taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 80°C.

Add 60% of the treated coal to this, respectively. (Bi' and 0.15 g of ferrous chloride were added, stirred, and then polymerized for 10 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain each graft polymer.

As comparative examples, graft polymers were produced in the same manner as above using coal treated in the same manner with a hydrogen peroxide solution to which no acid was added, and coal that was not treated with hydrogen peroxide at all, and the graft polymerization rate was determined.

The results are shown in Table 1. As shown in the table above, coal is
By treating with a hydrogen peroxide solution of H2 or less, the graft polymerization rate can be significantly increased compared to the case of no treatment or the case of simply treating with a hydrogen peroxide solution.

Vinyl monomers that can be used in the present invention include dimethylamine ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, tertiary salts thereof such as hydrochloride, sulfate, and acetate, and methyl chloride, dimethyl sulfate, and diethyl chloride. Quaternary salts quaternized with sulfuric acid, water-soluble vinyl monomers such as acrylic acid, methacrylic acid, acrylamide, and methacrylamide, hydrophobic monomers such as styrene, vinyl acetate, nisal acrylate, methacrylic acid ester, and acrylonitrile. Depending on the purpose of use, these may be used in combination.

Conditions for producing a graft polymer in which the above-mentioned vinyl monomer is treated with an acidic solution having a pH of 2 or less as described above, and then treated with a hydrogen peroxide solution, or graft polymerized onto coal treated with a hydrogen peroxide solution having a pH of 2 or less. As for the heptamer concentration, it varies depending on the type of monomer, but is generally in the range of 20 to 85% by weight.

Although there are no restrictions on the amount of coal added, the degree of polymerization generally decreases as the ratio of coal added to the monomer increases.

Regarding the reaction temperature, 20 to 80°C is desirable.

The polymerization time varies depending on the type of monomer, the degree of pulverization of coal, manufacturing conditions, etc., but approximately 5 to 15 hours is sufficient.

In the present invention, a polymer with a high graft polymerization rate can be obtained by simply mixing the coal treated as described above with a vinyl monomer, but in order to further accelerate the polymerization rate or take into account the use of existing equipment, This does not prevent the use of catalysts, ultraviolet light, and radiation during polymerization.

The graft polymer obtained by the present invention can be used as a water treatment agent and for coal-oil mixed fuel.

Below, actual cases of the present invention are listed and further explained.

Example 1゜100 to 300 in a beaker with an internal capacity of 1,000rfLl
A mesh coal of 250.9 mm was taken, to which 500.9 of hydrochloric acid with a pH of 0.5 was added, stirred for 3 hours, and then washed with water.

Next, 500.9 g of 30% hydrogen peroxide solution was added to the coal treated as above, and after stirring at 40'C for 5 hours,
It was filtered, washed with water, and dried under reduced pressure at 20°C.

Next, acrylamide 12.8.
! 9. Dimethylaminoethyl methacrylate methyl chloride salt 37.3f ion-exchanged water 50.0.9 was taken, stirred and dissolved while purging with nitrogen, and the liquid temperature was set at 60°C.

This was combined with the above-treated coal 1009 and ferrous chloride 0.
45.9 was added and stirred, followed by polymerization for 9 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain graft polymer 147.5. ! I got a 9.

(Graft polymerization rate 95%) Example 2, Content: t, 250 g of coal of 100 to 300 mesh was taken into a beaker of oooml, nitric acid 501 of pH 0.7 was added thereto, and after stirring for 3 hours, washing with water was carried out. went.

Next, 75 CBi' of a 20% hydrogen peroxide solution was added to the coal treated as described above, and the mixture was stirred at 50°C for 5 hours, filtered and washed with water, and dried under reduced pressure at 20°C.

Next, acrylamide 6.4.9.
18.79 grams of acrylic acid, 10.4 grams of caustic soda, and 1 ounce of ion-exchanged water were taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 80.degree.

To this, the above-treated coal 100.9 and ferrous chloride 0
．． 45.9 was added and stirred, and then polymerization was carried out for 8 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain graft polymer 134.1.

(Graft polymerization rate 96.0%) Example 3゜In a vertical beaker with an internal capacity of 1,000, 120 g of coal of 100 to 300 meshes and 20% 20% adjusted to pH 1.5 with sulfuric acid.
Hydrogen peroxide solution 36051' was added thereto, and the mixture was stirred at 40°C for 5 hours, filtered and washed with water, and dried under reduced pressure at 20°C.

Next, 5.1 g of acrylamide was placed in a reaction vessel with a content capacity of 500 rILl equipped with a stirrer, a nitrogen inlet tube, and a thermometer.
Dimethylaminoethyl methacrylate methyl chloride salt 14
．． 113 g of ion-exchanged water was taken and dissolved with stirring while purging with nitrogen, and the liquid temperature was set at 500C.

To this, the above-treated coal 200.1 and ferrous chloride 0
．． 91. ! After adding il and stirring, polymerization was carried out for 10 hours.

This polymer was thoroughly washed with water at 60°C and dried under reduced pressure to obtain graft polymer 218.4. ! I got a 9.

(Graft polymerization rate 92%) Example 4゜In a beaker with an internal capacity of 1,000 ml,
Add 120 g of mesh coal and 360 g of 20% hydrogen peroxide solution adjusted to pH 0.5 with hydrochloric acid, and
After stirring for an hour, the mixture was washed with water and dried under reduced pressure at 20°C.

Next, a stirrer with an internal capacity of 500 rIll, a nitrogen introduction pipe,
Styrene 100 is placed in a reaction vessel fitted with a thermometer and a cooling tube.
g and 100 g of the coal treated above were added, stirred, and polymerized in SO'C for 15 hours while purging with nitrogen.

This polymer was filtered, thoroughly washed with benzene, and dried under reduced pressure to obtain 183.2 g of a graft polymer.

(Graft polymerization rate 83.2%)

Claims (1)

[Claims] 1. A method of producing a graft polymer by treating coal with an acidic solution having a pH of 2 or less and then treating it with a hydrogen peroxide solution, or by treating it with a hydrogen peroxide solution having a pH of 2 or less and grafting a vinyl monomer onto the treated product. Production method.