JPH03265605A - New dimethylamnomethyl-diethylaminomethylpoly(meth) acrylamide - Google Patents

Abstract

PURPOSE:To obtain a poly(meth)acrylamide resin useful as a high-grade flocculant/dewatering agent, having dimethylamino groups and diethylamino groups in a ratio in a specified range. CONSTITUTION:A poly(meth)acrylamide resin of a mol.wt. of 500000-17000000, comprising repeating units of the formula [wherein R is H or methyl; and X is a group of the formula: -CH2Y (wherein Y is dimethylamino or diethylamino) or H], wherein the degree of substitution by X in the above formula is 1-90mol%, desirably 20-60mol%, and the ratio of the dimethylamino groups the diethylamino groups represented by Y is 99:1-50:50. In this way, a dimethylaminomethyl-diethylaminomethylpoly(meth)acrylamide useful as a high- grade flocculant/dewatering agent can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel Mannich type poly(meth)acrylamide resin useful as a polymer flocculant.

[Conventional technology]

Conventionally, among polymer flocculants, Mannich type flocculants, that is, dimethylaminomethyl polyacrylamide and dimethylamine, are used as a compound powder obtained by aminomethylating polyacrylamide with dialkylamino and formalin. The main reasons for this are that dimethylamino is lower in price than other aminos, and that higher amines have problems with residual odor from unreacted aminos, and that higher amines Because of its poor compatibility with polymers, reaction rate (aminomethylation rate)
Even if synthetic research has been carried out, it has not been commercially available due to the difficulty of obtaining high flocculation performance.

Furthermore, Mannich-type, or dimethylaminomethylpolyacrylamide-type, flocculants are rarely used alone for sludge, and at present they are always mixed with anionic compounds to maintain flocculation performance. No flocculant that alone is highly effective on all types of sludge has been publicly available. Furthermore, when carrying out the Mannich reaction with dimethylamine alone, a large excess of dimethylamine must be used to increase the molar ratio of formaldehyde in order to increase the colloidal equivalent, and even if a large amount of dimethylamine is used, formaldehyde alone cannot be used. It was difficult to suppress the generation of gelled products due to crosslinking.

[Problem to be solved by the invention]

In view of the above-mentioned circumstances, the inventor of the present invention solved the above-mentioned drawbacks and problems, and created a product that has high yield, high quality, and can be independently adapted to any kind of sludge, using a completely closed process. As a result of extensive research to ensure stable production,
Surprisingly, a Mannich base in the form of dimethylaminomethyl-diethylaminomethylpoly(meth)acrylamide, which is a mixture of dimethylamone and diethylamine, has an extremely effective flocculating ability, and has a very high flocculation ability during the reaction and when it is commercialized. It was discovered that the stability was significantly improved, and the present invention was completed.

[Means to solve the problem]

The dimethylagotsumethyl-diethylaminomethyl poly(meth)acrylamide of the present invention has the following formula (I): where R represents a hydrogen atom or a methyl group, and X represents the formula -
CH2Y (wherein, Y represents a dimethylamino group or a diethylamino group) or a hydrogen atom.

] Molecule 1i500,000 to 170 consisting of repeating units shown by
00,000 poly(meth)acrylic acid resin, the substitution rate of X in the above formula is 1 to 90 mol%, preferably 20 to 60 mol%, and the ratio of diethylamino groups to diethylamino groups represented by is 99:1 to 50:50.

The polymer compound of the present invention can be produced, for example, as follows.

That is, polyacrylamide or polymethacrylamide is reacted with a mixture of diethylamine and diethylamine in a molar ratio of 99:1 to 5:50, respectively, and a molecular salt of amine and formaldehyde. The water content of the reaction system is maintained at a high concentration of 30 to 70% and in a high viscoelastic range, and the reaction is carried out under pressure using a sealed kneader. After the reaction is completed, the pressure is reduced. While foaming, add a water-soluble salt powder or a water-soluble organic compound as a disintegrating agent, and finely disintegrate the particles into particles suitable for drying. The polymer compound of the present invention can be produced by drying using an air fluidized dryer.

During the production, formaldehyde and amines [i.e.
It is necessary to react a mixture of dimethylamine and diethylamine] in advance to form a molecular compound. At this time, the amines are a mixture of dimethylamine and diethylamine, each with a molar ratio of 9.
9:l~50:50, preferably 95:5~70
: Use one with a value of 30.

If the blending molar ratio is outside the above range, the cation colloid equivalent of the methylated product to be produced, that is, the aminomethyl group production rate will decrease.

In addition, the water content of the reaction system is 30 to 70%, preferably 4
It is 0-60%. If the water content is less than 30%, uniform dissolution will not be achieved, and molecular cleavage will rapidly increase.
If it exceeds 70%, the reaction rate will be slow and it will be difficult to obtain a high cationic colloid equivalent.

〔Example〕

Next, the present invention will be explained in more detail by showing Examples and Comparative Examples.

Example】.

254 kg of 50% dimethylamine aqueous solution and 50 kg of 50% diethylamine aqueous solution were mixed with 27 kg of 37% formalin.
4. 90% purity acrylic straw volimer 3
Together with 33 kg, the mixture was charged into a 2000 f bottom discharge type jet blade kneader while stirring. There was almost no sudden heat generation in the system even after the addition, and the reaction was carried out in a closed system while maintaining the temperature at 50°C±1°C. At the start of the reaction, the slurry remains, and after about 5 minutes it becomes a paste.
After 2 minutes, it became rubber-like with high viscoelasticity. The internal pressure at the start is close to normal pressure, but as soon as it becomes like a rubber with high viscoelasticity, the internal pressure decreases to 0.1 kg/cd, and from the start of the reaction the internal pressure is 2.
The pressure reached a maximum of 0.4 kg/cj at 0 minutes, and gradually decreased to almost normal pressure at 40 minutes from the start of the reaction. At this time, 4 kg of sodium sulfite and 20 kg of soda carbonate powder were added, and the system was kept at a vacuum level of 30 to 60 torr.The reactants were foamed and crushed, and when soda carbonate was added and left for about 15 minutes, 0.5 stiffness ~ 3.0
Uniform mixed crystal grains mainly composed of millimeters are obtained. Sodium carbonate was added for 20 minutes, and at 60 minutes from the start of the reaction, the automatic discharge screw of the liquid phase line was reversed and the discharge valve was opened for 30 minutes.
00 f conical dryer. When the injection is completed, the conical automatic valve is closed and the jacket temperature is 70°.
C ± 1°C, decompression degree 10 to 20 Torr, 60
After drying for minutes, 569.6 kg of product with a purity of 90.1% (the main impurity is water) is obtained, the particles of which are O11~
It has a uniform spherical shape with a main body size of 2.5 mm, and the theoretical yield of this product is 99.6%.The analytical values of the product are that the undissolved powder is 0.45%, and the colloid equivalent value is 4.9 milliequivalents. /gram, and the intrinsic viscosity was 9.1.

Furthermore, the polymer compound obtained in this example had the following formula (Ia
): [Wherein, X represents a group represented by the formula -CH,Y (wherein, Y represents a dimethylamino group or a diethylamino group) or a hydrogen atom. ] It consists of a repeating unit shown by, and has a molecular weight of 65
00,000, the substitution rate of X in the above formula is 50%, and the ratio of dimethylamino group to diethylamino group represented by Y is 80.
: It was 20.

Comparative Example 1 Dimethylaminomethyl polyacrylamide was produced in the same manner as in Example 1 except that diethylamine was used as the dialkylamine. The raw materials used, manufacturing conditions, and results are shown in Tables 1 and 2, respectively. In addition, the cation equivalents when changing the ratio of diethylamine to dimethylamine are shown in Figure 1, and the differences in aggregation properties between the dimethylaminomethyl polyacrylic acid system and the dimethyl acetate methyl-diethylaminomethyl polyacrylamide system of the present invention. This is shown in Figure 2.

(Margins below this page) Table 1: Purity conversion amount for this analysis Table 2 Next, the performance of the product of the present invention will be explained in detail with reference to the attached drawings.

FIG. 1 shows the cation colloidal equivalent of the aminomethylated product produced by varying the molar ratio of diethylamine (DEA) and diethylamine (DMA), that is, the aminomethyl radical conversion rate.

The ratio of polyacrylamide (P) to formaldehyde (F), F/P (0,716), and the ratio of amine (A) to formaldehyde (F), A/F・(1,73), are kept constant. With diethylamine (M) alone (zero addition of diethylamine), the colloidal equivalent is around 3.0, but as diethylamine (E) is added, diethylamine increases to nearly 20 mol% (E/M ratio). It reaches a peak, and as the amount is further increased, the colloidal equivalent decreases.

This is when the ratio of polymer (P) to water (H) in the reaction system is kept at 5°150, and by increasing the amount of jetylamine, the polarity in the system decreases and the polymer precipitates and separates. When increasing the amount of amine or using higher amines, the amount of water can be increased drastically, but it does not respond immediately to the high concentration reaction of the present invention. When higher amines are used, problems such as the odor of residual unreacted amines arise, but it is possible to increase the colloid equivalent and improve the coagulation performance.

FIG. 2 shows the relationship between colloid equivalent and flocculation performance. The flocculation performance (index) was expressed as the total flocculation performance using self-supporting properties, flocking properties, peelability, filtration properties, filtrate clarity, and dehydrated cake water content as indices. The molecular weight of the polymer used in this test was kept approximately constant. Dimethylaminomethyl polyacrylamide type (M) has low performance when used alone;
20% of anionic flocculant (polyacrylic acid, polysulfomethylated polyacrylamide, etc.) was added, and diethylaminomethyl and dimethylaminomethyl polyacrylamide types (E/M) were used alone.

It has been revealed that the aminomethylated product according to the present invention exhibits remarkable flocculation performance when used alone as compared to known aminomethylated products.

FIG. 3 shows the stability during reaction, that is, the rate of gel (crosslinking) generation.

The dimethylamine type (M) has a remarkable rate of gel formation during the reaction, and when the A/F ratio is set to 1.4, the H type suddenly becomes unstable and a good product cannot be obtained. E/? For type l, the A/F ratio is set to 1.7 rather than 1.7.
Even if it is set to 4, the stability is excellent, and even if the F/P ratio is increased and the colloid equivalent is increased, the formation of gel can be suppressed.

Figure 4 shows the stability of the product over time at room temperature. When we compared the stability of products that were commercialized and left at room temperature over the summer, we found that type H began to form a gel rapidly after being in stock for 3 to 4 months, and type E/M did not gel until 8 months had passed. It is stable.

Although preferred specific examples of the polymer compound of the present invention and the method for producing the same have been described above, it is also possible to make various changes thereto without departing from the spirit of the present invention.
This also falls within the scope of the present invention.

〔Effect of the invention〕

According to the present invention, it is possible to provide a novel dimethylaminomethyl-diethylaminomethyl poly(meth)acrylamide useful as a high-grade coagulation dehydrating agent.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the molar ratio of diethylamine (DEA) and diethylamine (DMA) and the cation colloid equivalent. FIG. 2 is a diagram showing the relationship between colloid equivalent and flocculation performance. FIG. 3 is a diagram showing stability during reaction. FIG. 4 is a diagram showing the stability of the product over time at room temperature.

Claims (1)

[Claims] 1. The following formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R represents a hydrogen atom or a methyl group, and X represents the formula -
CH_2Y (wherein, Y represents a dimethylamino group or a diethylamino group) or a hydrogen atom. ] Molecular weight consisting of repeating units shown by 500,000 to 1,700
In the ten thousand poly(meth)acrylamide resins, the substitution rate of X in the above formula is 1 to 90 mol%, preferably 2
A dimethylaminomethyl-diethylaminomethyl poly(meth)acrylamide having a content of 0 to 60 mol% and characterized in that the ratio of dimethylamino groups to diethylamino groups represented by Y is 99:1 to 50:50.