JPS6257617A - High molecular flocculant composition - Google Patents

Abstract

PURPOSE:To improve the storage stability of a high molecular focculant by using the high molecular flocculant contg. a polyacrylamide Mannich modified material and an aminoalcohol having a specified structural formula. CONSTITUTION:The homopolymer of acrylamide or methacrylamide or the copolymer with a vinyl monomer copolymerizable with the monomers is allowed to react with formaldehyde and dialkylamine to obtain a polyacrylamide Mannich modified material. From 1-30wt% compd. having a structural formula shown by the formula (R<1> and R<2> are 1-3 C alkyl groups and R<3> is a 1-3 C alkylene group) is incorporated into the polyacrylamide Mannich modified material to form a high molecular flocculant. The high molecular flocculant has excellent storage stability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to polymeric flocculant compositions endowed with long-term stability.

[Conventional technology]

Processing of suspensions discharged from various processes in factory wastewater, water and sewage, and chemical industries, concentration and dewatering of the resulting sludge, discharged from paper making and cleaning processes of M Paper Industries and Pulp Industries, etc. A method of using polymer flocculants in each building has been proposed and put into practical use for purposes such as recovering white water. Among these, polyacrylamide-based Mannich-modified products have strong cabonic properties, easily neutralize the charge 'f of negatively charged suspended solids, and exhibit excellent aggregation effects, so research into practical application is being actively pursued. It is being

Mannich modified polyacrylamide.

Carbamoyl group l mole f of acrylamide polymer
C. An aminoalkylated acrylamide polymer obtained by the action of 0.1 to 2.0 moles of formaldehyde and 0.2 to 4.0 moles of dialkylamine, and the polymer chain contains, at once, It contains three types of structural units: -Cn, -cH-, C0NHCH,OH.

Therefore, Mannich modifications are susceptible to hydrolysis and, as a result, a decrease in cation density. Also, N
- Methylol groups are extremely reactive, and when stored in a solution state, the N-methylol groups of and cause cross-linking reactions between or within molecules, and especially under acidic conditions, cleavage formation reactions occur, resulting in gelation (insoluble matter). (formation), which significantly reduces the product value.

For this reason, various methods have been proposed to improve storage stability (e.g., Japanese Patent Application Laid-Open No. 57-31904, Publication No. 49-1999).
15952, Special Publication No. 49-15953, Special Publication No. 57-8
801) has been done.

[Problem that the invention seeks to solve]

In general, the higher the concentration (5% or more) of polymer flocculants is, the better it is, and since they are often exposed to high temperatures of around 40°C in the IL field, it is better to store them with some leeway in the storage period. It is necessary for at least one month. Therefore, there is a need for a Mannich modified product that satisfies all of these conditions and has excellent storage stability. However, the conventional method described above could not satisfy all of the above conditions.

[Means for Solving the Problems] The present invention was made for the purpose of developing a polymer flocculant composition containing a polyacrylamide-based Mannich modified product that satisfies the above requirements regarding storage stability. This is a polymer flocculant composition characterized by containing a polyacrylamide-based Mannich modified product and a compound represented by formula 1.

In the formula, R' and R'' represent an alkyl group having 1 to 3 carbon atoms;
3 represents a γ-alkylene group having 1 to 3 carbon atoms.

In the present invention, polyacrylamide refers to a homopolymer of acrylamide or methacrylamide, or a copolymer of any of these heptamers with another vinyl monomer copolymerizable.

The polyacrylamide-based Mannich-modified product may be a modified product obtained by reacting the above polymer with formaldehyde and dialkylamine in a conventional manner, or a Mannich-modified polyacrylamide or methacrylamide monomer may be previously Mannich-modified in a conventional manner. A modified polymer obtained by polymerizing the thus-obtained Mannich-modified supermer with other copolymerizable vinyl monomers may also be used.

In order to enhance the storage stability of this Mannich-modified polyacrylamide-based product, this product contains a compound represented by the above formula 1.

Specifically, the compound represented by Formula 1 is N,N-dimethylmethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine SN, N-diethylpropanolamine, N.

N-dipropylethanolamine and the like fall under this category.

The blending ratio of these N,N-dialkylalkanolamines is 1 to 30% by weight, preferably 5 to 15% by weight, based on the Mannich-modified polyacrylamide product. t
In addition, as a blending method, a predetermined amount of N,N-dialkylalkanolamine may be added to an aqueous solution containing the L, polyacrylamide-based Mannich-modified product, or N may be added to the polyacrylamide-based polymer in advance before Mannich modification.

N-dialkylalkanolamine lTr may be added in a fixed amount, and formaldehyde and dimethylamine may be added to this aqueous solution to Mannich modification according to a conventional method.Furthermore, when producing a polymer from Mannich-modified heptamine, A predetermined amount of N, N is added to this Mannich modified monomer.
- Polymerization may be carried out after adding cyfurkyl alkanolamine.

The polymer flocculant composition containing the polyacrylamide-based Mannich modified product obtained in this way can be used as a sedimentation accelerator for suspended solids,
It can be effectively used as a sludge concentration and dehydration accelerator, a white water retention improver, and a paper strength enhancer.

[For production]

Although the effect of this invention is not clear, the N,N-dialkylalkanolamine represented by formula 1 participates or reacts with the N-methylol group in the polyacrylamide-based Mannich modified product, and the N-methylol group It is presumed that this prevents gelation caused by cross-linking reaction.

[Embodiments of the invention]

Example 1 Acrylamide monomer was dissolved in water at 2.0 mol/l,
Sodium metaperiodate was used as an initiator in % O, OS, based on the monomer, and polymerization was carried out at 45 DEG C. for 8 hours to give a polyacrylamide aqueous solution of 5.9 (dl/W-).

Next, to this polymer aqueous solution was added tL of a mixture of 37% Polmarine, 50%, and a dimethylamine aqueous solution (equal mole as formalin to polyacrylamide, 1.4 times mole as dimethylamine to polyacrylamide) ft, and heated to 40°C.
The mixture was reacted for 4 hours to obtain an aqueous Mannich-modified polyacrylamide solution at 30°C. The intrinsic viscosity of this polymer is 6
．． 4 (dl/)), the colloidal equivalent value is 6.6(me(!/?)) at p)l4, -0.0(me
q/i).

This Mannich modified aqueous solution of polyacrylamide was diluted with water to make an aqueous solution in a 10-layer lid, and 51[41% N,N-dimethylethanolamine was added to the polymer, and the change over time was observed at 40°C. saw. The results are shown in the table.

Example 2 The same operation as in Example 1 was performed except that 10% by weight of N,N-dimethylethanolamine was added, and the changes over time were observed. The results are shown in the table.

Example 3 The same operation as in Example 1 was performed except that 5% by weight of N,N-dimethylethanolamine in Example 1 was changed to 210% by weight of N,N-dimethylpropanolamine, and changes over time were observed. saw. The results are shown in the table.

Example 4 In Example 1, N,N-dimethylethanolamine t
-1! The same operation as in Example 1 was performed except that the amount of % was added, and the changes over time were observed. The results are shown in the table.

Example 5 The same procedure as in Example 1 was performed except that 30% by weight of N,N-dimethylethanolamine was added, and the changes over time were observed. The results are shown in the table.

Comparative Example 1 An aqueous solution of the Mannich-modified polyacrylamide containing 1O w/f% obtained in Example 1 (g) was left at 1140° C. to observe changes over time. The results are shown in the table.

Comparative Example 2 1N hydrochloric acid was added to the Mannich modified water bath solution of polyacrylamide of io weight % obtained in Example 1 to adjust the pH
After adjusting the temperature to 3, it was left at 40°C to observe changes over time.

The results are shown in the full table.

Comparative Example 3 1 Oit% of hydroxylamine hydrochloride was added to the 10wt% Mannich modified polyacrylamide water bath solution obtained in Example 1, and then the pH was adjusted to 3 with hydrochloric acid. It was left at ℃ and observed changes over time. The results are shown in the table.

From this table, it can be seen that the amount of N,N-dialkylalkanolamine added is 1 to 3. It can be seen that the results are good within the Oi test range, and that there is almost no change in the intrinsic viscosity or colloid equivalent value even after 30 days. In particular, it can be seen that the weight range of 5 to 15 weight is extremely good.

On the other hand, in Comparative Example 1 showing the conventional method.

Both increase the intrinsic viscosity, decrease the positive colloid equivalent value at pH 4, and negative colloid equivalent value at pHI Off.
An increase in 1lI was observed, and after 30 days, some of the water contained
Glycide was produced. In addition, in Comparative Examples 2 and 3, after 2.5 days, they were not dissolved at all in water and clearly formed a gelled product.

[Effects of the Invention] The polymer flocculant composition of the present invention, in the form of a highly concentrated aqueous solution of about 10%, shows almost no change in product quality even when stored for one month at a high temperature of 40°C, and is extremely stable. Shows good storage stability. Therefore, there is no need for refrigerated storage as in the past.

Claims (1)

[Scope of Claims] 1. A polymer flocculant composition comprising a polyacrylamide Mannich-modified product and a compound represented by formula 1. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[1] In the formula, R^1 and R^2 are alkyl groups having 1 to 3 carbon atoms, and R
^3 represents an alkylene group having 1 to 3 carbon atoms, respectively. 2. The composition according to claim 1, wherein the polyacrylamide system is polyacrylamide or polymethacrylamide. 3. The composition according to claim 1 or 2, wherein the compound represented by formula 1 is N,N-diethylethanolamine or N,N-dimethylpropanolamine.