JPH0680087B2 - Method for producing improved water-soluble acrylic amide polymer - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a water-soluble acrylamide polymer having improved dust generation and solubility.

Acrylic amide polymers are widely used in various fields such as coagulants for wastewater treatment, sticky agents for papermaking, sludge dewatering aids, chemicals for oil recovery, etc., but are generally supplied in the form of powder, When used in the above fields, these polymer powders are dissolved in water and used in a water-soluble form.

Problems to be Solved by the Invention At the time of this melting operation, since the polymer powder also contains fine particles, dust easily forms, which is often pointed out as an environmental problem. In addition, there are many cases in which so-called "maco" occurs and a long dissolution time is required.

In order to avoid the above-mentioned drawbacks due to such powder, it may be supplied in the form of gel in which the polymer content is about 20% by weight.
In this case, even if the slicing work is performed by shredding with a shredder such as an electric meat grinder, it is difficult to make the particles finer than in the powder product, and thus a long dissolution time is required. In addition, a paste-like product with a polymer content of 10% by weight or less is also used in part, but a gel-like product,
The problems common to pasty products are uneconomical, such as increased transportation costs and storage costs due to the low solid content.

An object of the present invention is to provide a method for producing a water-soluble polymer composition containing a high molecular weight and good water-soluble acrylamide polymer as a main component.

Means for Solving the Problems That is, the present invention, in the method for producing a water-soluble acrylic amide-based polymer containing hydrogel particles and a surfactant,
The hydrogel particles obtained by the usual manufacturing method are introduced into the drying step, and the polymer content in the hydrogel particles is 50 to 85% by weight.
After being dried to the state of containing, it is pulverized or is not pulverized and is humidified and granulated by using an aqueous solution of a surfactant, thereby improving dust generation and solubility. It is a method for producing a water-soluble acrylic amide polymer.

Action Hereinafter, the constituent features of the present invention will be described together with the action.

The present invention is a method for producing a water-soluble acrylic amide-based polymer, which comprises an acrylic amide-based polymer as a main component and which contains a small amount of a surfactant. As a monomer to be polymerized to obtain an acrylamide polymer, there are a case where only acrylate is used and a case where a copolymerizable with this is used in combination. Examples of the copolymerizable monomer include methacrylamide, methyl (meth) acrylate, and (meth)
(Meth) acrylic acid esters such as ethyl acrylate,
Acrylic acid and its salts, methacrylic acid and its salts, 2
Amidosulfonic acid such as acrylamido-2-methylpropanesulfonic acid and salts thereof, aminoalkyl esters such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate and salts thereof, amino such as dimethylaminopropylmethacrylamide Examples thereof include alkylamides and salts thereof.

The polymer may be any type of anion, cation and nonion, and may be a homopolymer or a copolymer.

The polymerization method of the acrylamide polymer is generally an ordinary free radical initiation polymerization, and in the case of aqueous solution polymerization, an ordinary radical initiator in an aqueous solution of the monomer concentration of 15 to 85% by weight, For example, one kind or two kinds or more selected from a peracid initiator, a redox initiator and an azo initiator is used for polymerization. The acrylic amide polymer is
After completion of the polymerization, various modifications such as a method of performing a hydrolysis reaction with an alkali to convert it into an anionic carboxyl group, a Mannich reaction, a method of introducing a cationic amino group by a Hoffmann decomposition reaction, etc. Good. Usually, the hydrogel particles having a polymer content of 20% by weight or more obtained by the above method are introduced into a drying step and dried to obtain hydrogel particles having a water content of 20 to 95% by weight.

In the present invention, during the drying process of the hydrogel particles as described above, the acrylamide polymer content is 50 to 85 wt%, preferably 60 to 80 wt% and water 50 to 15 wt%, preferably 40 to 20 wt%. %, And pulverize with a cutting machine or without using hydrogel particles having a particle size of 2 mm or less, and wet granulation with a surfactant aqueous solution or mixed solution. Drying is usually performed at 70-100 ° C.

In this case, if the polymer pure content is less than 50% by weight, the water content is increased, so that the powder particles cause caking and the product transportation cost increases, which is not preferable. On the other hand, the polymer content is 85
If it exceeds 5% by weight, dusting occurs, and it tends to become "makko" when dissolved. The particle size of 2 mm or less is for increasing the dissolution rate.

In the present invention, with respect to the water-containing gel particles, a polymer content of 500 to 20000 ppm of a surfactant is added,
Specific examples of the surfactant include polyethylene glycol having an average molecular weight of 400 or more, polypropylene glycol, or polyoxyalkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene / polyoxypropylene block polymer. , Nonionic surfactants such as polyoxyethylene sorbitan fatty acid ester and sorbitan fatty acid ester. Among these, sorbitan monooleate and polyethylene glycol having an average molecular weight of 1000 or more are particularly preferable. As the surfactant, a surfactant other than these, inorganic salts, oils and the like can be further contained. This surfactant is for preventing caking during storage of the hydrogel particles, if it is less than 500 ppm, the caking prevention is insufficient, and if it exceeds 20,000 ppm, the composition becomes sticky and the fluidity is high. It deteriorates and the handling becomes worse.

The polymer content obtained as described above is 50 to 85% by weight.
500 to 20000ppm based on the polymer content of hydrogel particles
Of surfactant. In order to contain the surfactant, it may be added as an aqueous solution or a mixed solution by an addition means such as spraying and kneading. By doing so, the water-containing gel particles absorb water to form a gel, and fine particles of about 0.1 mm or less are stuck to each other to be granulated to obtain granules of about 2 mm or less that do not stand up.

The surface thereof is almost covered with a surfactant, and even if it is stored under a load for a long period of time, caking is prevented, dust is not generated at all, and solubility is excellent.

Examples The present invention will be further described with reference to the following examples.

Example 1 A copolymer hydrogel having a molar ratio of acrylic amide and sodium acrylate of 85:15 obtained by a usual production method (polymer pure content 30% by weight, moisture 70% by weight) was introduced into a drying step, 60% by weight polymer content after drying at 80 ℃
Of water-containing gel particles.

This was charged into a rotary drum type mixing granulator at a rate of 1000 g, and while being rotated, the surfactant aqueous solution was changed as shown in Table 1 and sprayed, and mixed by stirring for 30 minutes. Table 1 shows these conditions and the evaluation results.

Example 2 Example 2 was repeated except that the water-containing gel taken out from the drying step of Example 1 had a polymer content shown in Table 2. A was used as the surfactant.

The symbols of the surfactant product names in Table 1 represent the following, and the evaluation was carried out by the following method.

1) Surfactant Product name A: Sorbitan monolaurate (Product name Leodol SP ・ L1
0) B: Polyethylene glycol monooleate (trade name Emanone 4110) C: Polyoxyethylene higher alcohol ether (trade name Emulgen 707) D: Polyoxyethylene sorbitan monooleate (trade name Leodol TW-0120) E: Polyoxyethylene Polyoxypropylene block polymer (brand name Emulgen PP-230) F: Polyethylene glycol # 400 G: 〃 # 6000 2) Evaluation test and evaluation standard (1) Powder standing test Drop 100g of sample from 50cm height, drop point Than 30
The light transmittance was measured on a 5 × 5 cm horizontal glass plate placed at a distance of cm. The transmittance is 480 nm using a spectrophotometer.
It was measured at.

(2) Mako generation during dissolution 1g of sample was dropped at a time in 1000ml of still water, then
After stirring at 400 rpm for 60 minutes, the undissolved content was filtered through a 150 mesh wire net and evaluated.

(3) 200 g of caking sample was filled in a plastic bag and sealed, and a weight of 100 g / cm ² was added for one week, and the state of once granulated and united by weight was observed.

◎… No solidification at all ○… Slightly blocky, but it collapses when touched lightly.

Δ: Solidification is seen and the material collapses when crushed.

×: It is difficult to unravel with a complete block.

(4) Solubility Add 1 g of sample to 1000 ml of water stirred at 400 rpm,
After dissolving for 90 minutes, filter with a 150 mesh wire net and observe the insoluble matter.

EFFECTS OF THE INVENTION According to the present invention, a water-soluble polymer composition containing a high-molecular-weight and water-soluble good acrylic amide polymer as a main component, which has not been obtained in the prior art, is very simple and inexpensive. Can be obtained.

Further, the composition of the present invention is notable for caking even after long-term storage under load, has no powdering at the time of use, is easy to handle, and hardly dissolves in water. .

Claims (1)

[Claims] 1. In a method for producing a water-soluble acrylamide polymer containing hydrogel particles and a surfactant, the hydrogel particles obtained by an ordinary production method are introduced into a drying step,
After being dried until the polymer content in the hydrogel particles is 50 to 85% by weight, it is pulverized or is not pulverized and is subjected to humidification granulation using an aqueous surfactant solution. A method for producing a water-soluble acrylic amide polymer having improved dusting and solubility.