JP2598017B2 - Method for producing water-soluble cationic polymer - Google Patents

Description

The present invention relates to a method for producing a water-soluble cationic polymer.

[Prior Art] Water-soluble polymers are widely used in many industrial fields and occupy an important position in the industry. Typical examples of the use include solid-liquid separation agents in the manufacturing process; coagulating sedimentation agents in industrial wastewater treatment; dewatering aids for sludge in sewage and human waste treatment; papermaking agents such as paper strength agents and filler retention improvers;
Soil improvers; thickeners; oil recovery agents, and the like.

Various methods are used for producing a water-soluble polymer, and the most common method is an aqueous solution polymerization method.

As an example of industrially carrying out aqueous solution polymerization, an example using a photoinitiator in the form of a sheet is disclosed in JP-A-52-1264.
Japanese Unexamined Patent Publication No. 94-133287 and Japanese Unexamined Patent Publication No. Sho 53-133287 disclose a method of irradiating light in a sheet shape by covering the surface with a film.
It is disclosed in JP-A-61-611303 and JP-A-61-221202.

[Problems to be Solved by the Invention] However, when the sheet-like water-soluble cationic polymer is produced by the above-mentioned method, the resulting water-soluble polymer has a strong adhesive force, and this is likely to be the inner wall of the container after polymerization or the polymerization. However, there is a drawback in that the film sticks to the film used in this case, and it takes much time and effort to release the polymer therefrom.

As a solution to this, it is conceivable to spray or apply a release agent to the inner wall of the container or the film before the polymerization, but such a treatment is not practical.

[Means for Solving the Problems] The present inventors have conducted intensive studies in view of the above-described prior art, and as a result, when a specific surfactant is added to a monomer and polymerized, the above problems are solved. They found what they could do and completed the present invention.

The method for producing a water-soluble cationic polymer of the present invention is characterized in that, when a water-soluble cationic monomer solution is polymerized by irradiating light in a container having a depth of 50 mm or less, a cation is added to the water-soluble cationic monomer solution. It is characterized by adding 0.01 to 2.0% by weight of a system surfactant.

The water-soluble cationic polymer in the present invention means a polymer that can give a cation when the polymer is dissolved in water. Further, a water-soluble cationic monomer is a monomer capable of producing a polymer that dissociates to give a cation when a polymer obtained by polymerizing the monomer is dissolved in water. means.

Examples of the water-soluble cationic monomer used in the present invention include tertiary amine salts and quaternary ammonium salts. Examples of the tertiary amine salt include tertiary amine salts such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 3-dimethylamino-2-hydroxypropyl (meth) acrylate, and dimethylaminopropyl (meth) acrylamide.
Salts obtained by neutralizing a secondary amine with an acid such as hydrochloric acid or sulfuric acid are mentioned. As quaternary ammonium salts,
For example, dimethyldiallylammonium salt, diethyldiallylammonium salt and the like can be mentioned, and a salt obtained by quaternizing the above tertiary amine with an alkyl halide, dimethyl sulfate or the like can also be used. Here, examples of the alkyl halide used for quaternization include methyl chloride, methyl bromide, methyl iodide and the like. These can be used alone or in combination of two or more.

In carrying out the method of the present invention, the monomer concentration may be any concentration as long as the uniformity of the system can be maintained, and is not particularly limited. On an industrial scale, it is desirable to carry out the process at a high monomer concentration. This is because when the monomer concentration is low, the drying cost is high, the transportation cost is high for a liquid product, and the production of a high molecular weight polymer requires a long time.

Therefore, the concentration of the cationic monomer in the aqueous polymerization solution is 25 to 90% by weight, preferably 45 to 85% by weight.

In the method of the present invention, a nonionic monomer such as acrylamide, methacrylamide, dimethylacrylamide, and hydroxyethyl methacrylate can be added to the above-mentioned cationic monomer as needed. The amount of the nonionic monomer used is preferably in the range of 90 to 10 parts by weight based on 10 to 90 parts by weight of the cationic monomer.

The cationic surfactant used in the method of the present invention is not particularly limited, but preferably contains a quaternary ammonium salt as a hydrophilic group in the molecule. Examples thereof include tetraalkyl quaternary ammonium salts. Salts, trialkylbenzyl quaternary ammonium salts, alkylpyridinium salts, and alkylquinolinium salts.

The necessary amount of these cationic surfactants varies depending on the properties of the homopolymer, copolymer, gel concentration, etc., and is generally difficult to determine, but 0.01% based on the weight of the water-soluble cationic monomer solution. ２2% by weight. If it is less than 0.01% by weight, there is no effect, and if it exceeds 2% by weight, no increase in the effect is observed, which is economically disadvantageous.

In the method of the present invention, in order to adjust the degree of polymerization of the obtained polymer, a chain transfer agent exhibiting acidity may be added in a range of 2 to 2000 ppm based on the water-soluble cationic monomer solution. Examples of the chain transfer agent used include mercapto group-containing compounds such as thioglycolic acid and mercaptopropionic acid, and phosphorus-containing compounds such as phosphorous acid and hypophosphorous acid.

Photoinitiators that can be used in the method of the present invention may be generally known initiators, and typical examples thereof include benzoin, benzoin alkyl ether, and anthraquinone derivative.

The amount of the photoinitiator used is in the range of 10 to 2000 ppm based on the water-soluble cationic monomer solution. Below 10 ppm,
The effect as a polymerization initiator is small, and if it exceeds 2000 ppm, it becomes difficult to obtain a high-viscosity polymer, which is not preferable.

The container having a depth of 50 mm or less used for polymerizing the cationic monomer solution is not particularly limited, but a box-shaped container or a continuous production facility provided with weirs on both sides of an endless belt is preferable. If the depth of the container is deeper than 50 mm, the polymerization in the thickness direction is not uniform, which is disadvantageous. Also,
Bags made of a light-transmitting plastic film can also be used.

Polymerization, a film such as a polytetrafluoroethylene film showing non-adhesiveness to the polymer is spread in the above-mentioned container, a predetermined amount of the above-mentioned polymerization solution is put therein, and the surface thereof is placed under an inert atmosphere. Polymerization is performed by irradiating light from above in a plastic film or in a plastic bag. After the polymerization, the polymer is taken out of the container, and when a film is used, it is peeled off.

As the plastic film covering the surface, a light-transmitting film is used, but a film having a low oxygen permeability is preferable, and it is preferable to select a film in consideration of heat resistance.
As the film to be used, a film in which polyvinylidene chloride is applied to polyethylene terephthalate is preferable.The light used in the polymerization step of the present invention includes light of various wavelengths depending on the combination with the initiator. In terms of absorption by itself and photon energy, 30
Light having a wavelength in the range of 0-500 nm is desirable. Examples of the light source that provides light of 300 to 500 nm include a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a fluorescent chemical lamp.

 Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 929 g of an aqueous solution of dimethylaminoethyl methacrylate methyl chloride quaternary salt having a monomer concentration of 80% and 371 g of a 50% aqueous acrylamide solution were collected.

Benzoin ethyl ether 100ppm, ethylenediamine tetraacetic acid disodium salt 50ppm, phosphorous acid 5
A solution to which each was added so as to be 00 ppm was prepared. To this prepared solution, a high amine 1622 (cationic surfactant) manufactured by ROHM & HASS, respectively, was added in an effective amount of 0, 0.01, 0.05, and 0.
It was added so as to be 10, 0.5 and 1.0% by weight.

The temperature of the monomer solution was adjusted to 30 ° C., and 10 N sulfuric acid was added with stirring to adjust the pH to 4.5 ± 0.1.

Perform nitrogen replacement for 30 minutes, make a weir around the stainless steel plate to a depth of 20 mm, attach a polytetrafluoroethylene film on it and make a container with a bottom of about 23 cm × 23 cm, The monomer solution was poured and the top was covered with a film of polyethylene terephthalate coated with polyvinylidene chloride (12 + 4μ). Then, ultraviolet light was irradiated from above using a fluorescent chemical lamp manufactured by Mitsubishi Electric Corporation at an irradiation intensity of ² W / m ² for 50 minutes, and then at 50 W / m ² for 10 minutes.

The obtained gel polymer was taken out of the container with the cover film attached. After cutting the peripheral part 1.5 cm with scissors, it was further cut into strips of 5 cm × 10 cm. After a 5 cm wide film was peeled off from the sample by 5 cm by hand, a portion of the film having a width of 5 cm and a length of 3 cm was sandwiched by a clamp, and a tensile tester (Tensilon; Toyo Baldwin Co., Ltd.) was used to pull the film at a pulling speed of 5 cm / min. Was used to measure the peel strength. Five measurements were made and the average was determined.

 The results are shown in Table 1 below.

Example 2 Instead of the aqueous solution of quaternary methyl chloride of dimethylaminoethyl methacrylate in Example 1, an aqueous solution of quaternary salt of methyl chloride of dimethylaminoethyl acrylate was used.
A polymer was produced in the same manner as in Example 1 except that the addition was performed so as to be 5, 0.10, 0.5, and 1.0%. The results are shown in Table 2 below.

Example 3 In Example 1, the monomer was an aqueous solution of a quaternary salt of methyl chloride of dimethylaminoethyl methacrylate alone, and 10 ppm of β-mercaptopropionic acid was added instead of phosphorous acid to adjust the pH to 3.5 ± 0.1. Example 1 except for
A polymer was produced in the same manner as described above. The results are shown in Table 3.

[Effects of the Invention] According to the present invention, in producing a water-soluble cationic polymer, a cationic surfactant is added to an aqueous monomer solution, and the pH is adjusted, whereby the obtained polymer and the polymer are polymerized. Removability from a container or a film sometimes used can be improved. Therefore, not only long-term continuous production is possible, but also a film to be used can be thin enough to withstand peeling, and the effect is economically significant.

Continued on the front page (72) Inventor Kenichi Inukai 20-1 Miyukicho, Otake City Inside Mitsubishi Rayon Co., Ltd. (72) Inventor Nagayuki Takahashi 3 Kaigandori, Toyama City Diafloc Co., Ltd. In-house (72) Inventor Yoji Wada Noda 138 Ichitsutsutsuka Diafloc Co., Ltd.

Claims (2)

(57) [Claims] When a water-soluble cationic monomer solution containing a photoinitiator is polymerized by irradiating light in a container having a depth of 50 mm or less, a cationic surfactant is added to the water-soluble cationic monomer solution. Characterized by adding 0.01 to 2.0% by weight of the agent,
A method for producing a water-soluble cationic polymer. 2. The method for producing a water-soluble cationic polymer according to claim 1, wherein the cationic surfactant contains a quaternary ammonium salt as a hydrophilic group in the molecule.