JPH0788456B2 - Method for producing water-soluble polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a water-soluble polymer composition containing a water-soluble acrylamide polymer as a main component and having good solubility and handleability.

BACKGROUND ART Acrylamide-based polymers are widely used in various fields such as coagulants for wastewater treatment, thickeners for papermaking, sludge dewatering aids, chemicals for oil recovery, etc. When used in the field, these polymer powders are dissolved in water and provided in the form of an aqueous solution.

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, it is difficult to make the particles finer than those of the powdered product, even if the product is shredded by a shredder such as an electric meat grinder during the melting work, and thus a long melting time is required. In addition, some paste products with a polymer content of 10 wt% or less are also used, but the common problems with gel products and paste products are non-economical factors such as increased transportation costs and storage costs due to low solid content. Is.

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

Means for Solving the Problems That is, the present invention comprises hydrogel particles of an acrylamide polymer and a surfactant, and the surfactant is 500 to 20000 ppm with respect to the polymer content of the particles. A water-soluble polymer composition and (2) a method for producing a water-soluble polymer composition containing a hydrogel particle of an acrylamide polymer and a surfactant,
Acrylamide-containing hydrogel particles having a polymer content of 20% by weight or more are cut into fine particles so as to have a particle size of 3 to 10 mm and dried to a polymer content of 85 to 95% by weight. After pulverizing to a pulverized product with a particle size of 2 mm or less, add 500 to 20000 ppm of surfactant to the pulverized polymer content of this pulverized product, and moisturize granulation so that the polymer content is 50 to 85% by weight. And a method for producing a water-soluble polymer composition.

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

The composition of the present invention comprises an acrylamide polymer as a main component and a small amount of a surfactant contained therein.
The monomer to be polymerized to obtain the acrylamide polymer may be acrylamide alone or may be a monomer copolymerizable with acrylamide. Examples of the copolymerizable monomer include methacrylamide, methyl (meth) acrylate,
(Meth) acrylic acid esters such as ethyl (meth) acrylate, acrylic acid and salts thereof, methacrylic acid and salts thereof, amide sulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid and salts thereof, dimethylamino Examples thereof include aminoalkyl esters such as ethyl (meth) acrylate and diethylaminoethyl (meth) acrylate and salts thereof, and aminoalkylamides such as dimethylaminopropylmethacrylamide and salts thereof.

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

The acrylamide polymer is generally polymerized by free radical initiation, and in the case of aqueous solution polymerization, an ordinary peroxide initiator is added to an aqueous solution having the above monomer concentration of 15 to 85% by weight. Polymerization is carried out using one kind or two or more kinds among redox initiators and azo initiators. still,
Acrylamide-based polymers, after the completion of polymerization, various modifications,
For example, a method of carrying out a hydrolysis reaction with an alkali to convert it into an anionic carboxyl group, and a Mannich reaction may be carried out by a method of introducing a cationic amino group by a Hoffmann decomposition reaction. Usually, the polymer obtained by the above method is dried in the drying step to obtain hydrogel particles having a water content of 20 to 95% by weight.

In the present invention, among the hydrogel particles as described above, the acrylamide polymer is 50 to 85% by weight, preferably 60 to 80%.
Wt% and moisture 50 to 15 wt%, preferably 40 to 20 wt%
The hydrous gel particles having a particle size of 2 mm or less are used.

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.

The composition of the present invention, with respect to the water-containing gel particles, is one in which a surfactant of 500 to 20000 ppm is blended per polymer pure content, and as a specific example of the surfactant contained in the composition of the present invention, the average molecular weight is 400+ polyethylene glycols,
Similarly, nonionic surfactants such as polypropylene glycol, polyoxyalkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, etc. Can be mentioned.
Of 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 effective for preventing caking of the hydrogel particles during storage, and if it is less than 500 ppm, caking prevention is insufficient, and this caking also causes "maco" during dissolution. On the other hand, if it exceeds 20,000 ppm, the cost becomes high and the composition becomes sticky, resulting in poor fluidity and poor handleability.

As a preferred method for producing such a water-soluble polymer composition, first, an acrylamide polymer is obtained as a hydrogel particle having a polymer content of 20% by weight or more and a particle diameter of 3 to 10 mm in a usual production method. This is dried to a polymer content of 85 to 95% by weight, and the polymer is finely divided into particles having a predetermined particle size, and this is re-wet to obtain a polymer content of 50 to 85% by weight, preferably 60 to 80% by weight. Gel particles.

The reason why the polymer pure content is once dried to 85 to 95% by weight and then humidified to the polymer pure content of 50 to 85% by weight is because the polymer is extremely difficult to be finely granulated in the hydrogel state.

That is, in the usual production method, the polymer content is, for example, 20 to 35.
The wt% hydrogel particles are chopped to a particle size of 3-10 mm using a cutter, preferably a cutter mill, or a meat chopper, and then dried to a polymer content of 85-95 wt%. This dry gel particle can be easily
It is crushed to a powder of 2 mm or less.

When a predetermined amount (amount necessary to contain 500 to 20000 ppm relative to the polymer content) of the pulverized product obtained as described above and a surfactant and water are added separately or as an aqueous solution and kneaded. , The dried gel particles absorb water to form a gel,
Fine powder finer than about 0.1 mm is stuck and granulated to form a granule of 2 mm or less that does not stand up. Then, the surface thereof is almost covered with the surfactant, and when it is stored, caking is prevented, handling is easy, and a highly soluble product is obtained.

The composition of the present invention obtained as described above will be described below with reference to Examples.

Example A powdery polymer produced by an ordinary production method (90% by weight of polymer, 10% by weight of water, molar ratio of acrylamide and sodium acrylate is 85:15, particle size is 2 mm or less) 1000 g of each is produced by rotary drum type mixing granulation. We put it in a machine and, while rotating it, spray the added water in which the surfactant was dissolved with a hand-push type sprayer, about 30
Stir and mix for minutes. The test conditions and the evaluation results of the products are shown in Tables 1 and 2.

Also, the same experiment was conducted using a wet extrusion type granulator, and the same result as that of the rotary drum type mixing granulator was obtained.

The symbols of the surfactant product names in Tables 1 and 2 represent the following, and the evaluation was performed 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 criteria (1) Powder standing test Drop 100 g of sample from a height of 50 cm, and drop point Than 30
The light transmittance was measured on a 5 × 5 cm horizontal glass plate placed at a distance of cm. The light transmittance is 48 wavelength using a spectrophotometer.
It was measured at 0 nm.

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

Effects of the Invention As described in detail above, since the surface of the composition of the present invention is coated with a surfactant, caking does not occur even after long-term storage under load, and it is easy to handle without powdering at the time of use. The effects of the invention are remarkable, such as the fact that when dissolved in water, it does not easily become a cocoon. Further, according to the present invention, a water-soluble polymer composition having a high molecular weight and a water-soluble good acrylamide polymer as a main component, which has not been obtained in the prior art, can be obtained very easily and inexpensively. To be

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hikada Tsuboi 2636-23 Noba-cho, Konan-ku, Yokohama-shi, Kanagawa Prefecture (56) References JP-A-53-81555 (JP, A) JP-A-49-3950 (JP) , A) JP 52-121658 (JP, A) JP 51-47937 (JP, A) JP 54-103450 (JP, A) JP 55-131055 (JP, A) JP 56-88463 (JP, A) JP-A-57-73039 (JP, A) JP-A-57-49643 (JP, A) JP-A-57-90035 (JP, A)

Claims (2)

[Claims] 1. A method for producing a water-soluble polymer composition comprising acrylamide polymer hydrogel particles and a surfactant, wherein the acrylamide hydrogel particles having a polymer content of 20% by weight or more are granulated. The product was cut into fine particles with a diameter of 3 to 10 mm, dried to a polymer content of 85 to 95% by weight, and then the dried product was crushed to obtain a crushed product having a particle size of 2 mm or less. A water-soluble polymer composition characterized by being humidified and granulated so that the polymer content is 50 to 85 wt% while adding a surfactant of 500 to 20000 ppm to the polymer content of the pulverized material together with water. Manufacturing method. 2. The method according to claim 1, wherein the humidification granulation is carried out by using a rotary drum type granulator, a ribbon mixer type powder mixer, a fluidized granulation coating machine, a wet extrusion type granulator, and a powder kneader. A method for producing the water-soluble polymer composition according to the item (1).