JPS6361059B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing wastewater treatment materials. More specifically, the present invention relates to a wastewater treatment material made of open-cell urethane foam containing anionic groups in its molecules. The present inventors previously made an invention regarding a wastewater oil treatment material using open-cell urethane foam having a cationic group (basic group) (Japanese Patent Application No. 51-117651). Relatedly, in particular, the present invention is a method for producing an anionic group-containing polyurethane foam that can introduce anionic groups into the molecules of the urethane foam and utilize the polarity of the anionic groups as a wastewater treatment material. Conventionally, well-known water treatment materials include nonwoven fabrics such as polypropylene, polyethylene, or nylon fibers, ordinary polyurethane foam (which does not have ionic groups in its molecules), and activated carbon or ion exchange resins. . However, when considering these from the perspective of water treatment materials, they do not necessarily have sufficient characteristics. That is, from the perspective of the field of wastewater treatment that contains substances with cationic groups (basic substances), which are the target substances to be treated in the present invention, none of these fiber-based water treatment materials have polarity. Therefore, the adsorption filtration effect of treated substances in wastewater is exclusively a physical adsorption effect by the so-called micro gaps between fibers, and therefore, the treated substances that can be collected by this method are only coarse particles. Therefore, it is almost impossible to treat fine particles such as dye particles or water-soluble substances. Furthermore, with regard to the adsorption effect of activated carbon, the surface of activated carbon itself does not have polarity, and only the physical adsorption effect due to the microporous structure of activated carbon exists, and this effect cannot be said to be sufficient. Furthermore, ion exchange resins only perform electrostatic adsorption and have a low physical adsorption effect. Recently, more and more porous type ion exchange resins have been developed, but they do not have the highly porous foam structure required by the production method of the present invention, and therefore the physical adsorption effect of fine particles is not sufficient. Since its form is pellet-like, it is not always convenient to handle. Therefore, in order to eliminate these drawbacks, the present inventors developed a method for treating wastewater containing substances with cationic groups, which have traditionally been considered difficult to treat.
The present invention was developed as a result of intensive research into treatment materials suitable for adsorption treatment, especially adsorption materials for water-soluble or fine particulate cationic group-containing substances, which are difficult to treat with conventional adsorption treatment materials. It is. In other words, the method for producing the wastewater treatment material of the present invention chemically removes substances having cationic groups such as basic dyes, cationic dyes, and other amine-based substances in wastewater using the anionic groups in the open-cell polyurethane foam. In addition to adsorbing to the polyurethane foam, the microcellular structure unique to the open-cell polyurethane foam has physical adsorption due to hydrophobic bonds, etc., thereby producing an anionic group-containing polyurethane foam with good adsorption properties. In particular, it has been found that the anionic group-containing polyurethane foam produced according to the present invention exhibits an unexpectedly remarkable adsorption ability as a wastewater treatment material. The essential parts of the present invention are that component (a) is a polyfunctional polyoxylalkylene polyol, component (b) is an aliphatic or aromatic polyisocyanate, singly or in a mixture, and component (c) acts as an anionic group. 1 active hydrogen having a carboxylic acid group or a sulfonic acid group capable of reacting with the organic polyisocyanate component.
A chain extender component having ~3 components, with the above three components ABC as the main components, and the ionic group content concentration of component C being required to be 0.5 to 10 weight percent with respect to the total amount of the three components ABC. , a method for producing anionic group-containing urethane foam wastewater treatment material made of polyurethane foam having soft or semi-rigid open cells. Next, three main components in the production of the anionic group-containing wastewater treatment material according to the present invention will be explained. Component a (polyol) is a polyfunctional polyoxyalkylene polyol, and this polyoxyalkylene polyol is generally used for producing polyurethane, such as tetrafuran, ethylene oxide, propylene oxide, butylene. It is a polymerization product or copolymer such as oxide, and has a molecular weight of about 200 to 10,000, preferably 200 to 8,000. As component b (polyisocyanate), aliphatic or aromatic polyisocyanates may be used alone or in mixtures. That is, this polyisocyanate is an aliphatic or aromatic polyisocyanate, such as 2.4-tolylene diisocyanate, 2.6-tolylene diisocyanate or a mixture thereof, 4.4'-diphenylmethane diisocyanate, 1.5-naphthylene diisocyanate, In addition, there are polyphenyl polyisocyanates (eg, triphenyl-P-triisocyanate, etc.). Preferably, an 80:20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate and a mixture of polyphenyl polyisocyanate are used. Component c (chain extender) is a particularly important component in the present invention, and has a carboxylic acid group or a sulfonic acid group that can act as an anionic group, and is not reactive with the polyisocyanate component. Compounds having 1 to 3 active hydrogen atoms, particularly those having a carboxylic acid group, include, for example, dimethylolpropionic acid, or a reaction product of a derivative compound from glycerin and maleic anhydride, that is, A compound having an ester bond and a terminal carboxyl group resulting from a ring-opening reaction of maleic anhydride, which is an acid anhydride, with the OH group of glycerin is suitable. Moreover, examples of those having a sulfonic acid group include sodium benzidine sulfonate and taurine. The urethane foam with anionic groups obtained by foaming the urethane by simply mixing and stirring the above three important components a, b, and c is as follows:
All have communicating cells, and the concentration of ionic groups is
It is necessary that the content be in the range of 0.5 to 10% by weight, because if it is less than 0.5% by weight, the adsorption to substances with cationic groups will be poor, and if it is more than 10% by weight, the physical properties of the urethane foam will be poor. deterioration, leading to disadvantages such as brittleness. Describing the urethane foaming reactions of the main components a, b, and c in the present invention, the isocyanate index is
It is desirably 100-110, preferably 103-107. The polyurethane foam has a specific gravity of 0.02 to 0.10, preferably 0.03 to 0.07. Next, in the present invention, the above-mentioned components a, b, and c3 are used as main components, but it is of course possible to add a blowing agent or the like as necessary. next,
The present invention will be explained in more detail with reference to Examples. Example 1 (Urethane foam manufacturing method) Table 1 Polyurethane foaming stock solution composition with anionic group EP240: 5 parts by weight FA103: 5 MDI-CR: (NCO index 102) Chain extender with anionic group 100 Water 2 〃 SH-194 1 〃 Freon-11 10 〃 (Note) EP240: Trifunctional polyol, OH value 25 (manufactured by Mitsui Nisso Urethane Co., Ltd.) FA103: Trifunctional polyol, OH value 50 (manufactured by Sanyo Chemical Industries, Ltd.) MDI -CR: Crude MDI, a mixture of diisocyanate of diphenylmethane and higher polyisocyanate (manufactured by Mitsui Nisso Urethane Co., Ltd.) Chain extender with anionic group: AM-30 (a derivative of glycerin and propylene oxide, a trifunctional polyol) ...manufactured by Asahi Denka Co., Ltd.) and maleic anhydride, the maleic anhydride undergoes a ring-opening reaction and has an ester bond and a terminal carboxyl group. SH-194: Silicone foam stabilizer (manufactured by Toray Silicone Co., Ltd.) Freon-11: Foaming agent trichloromonofluoromethane (manufactured by Daikin Industries, Ltd.) Mix and stir the ~ ingredients shown in Table 1 above and mold this. was injected and foamed. After foaming and solidification, the mold was removed. The properties of this obtained polyurethane foam are:
As shown in Table 2. Table 2 Characteristic specific gravity of anionic group-containing urethane foam: 0.05 Cell structure: Open cell average cell size: 0.7 mm (diameter) Ionic group content concentration: 5% by weight (-
(as COOH) Example 2 (Wastewater Treatment Part 1) Demonstrates the effect of treating dyeing wastewater using the urethane foam produced in Example 1 as a wastewater treatment material (static adsorption effect) The raw water concentration was set to 0.5 g/ Place the adjusted model dyeing wastewater 1 in beakers, and add 5g of anionized urethane foam treatment material to each beaker.
5 g of gel-type cation exchange resin and 5 g of ordinary urethane foam were weighed out, and after being immersed and left standing for 3 days, the concentration of the remaining solution was measured by absorbance using a spectrophotometer. The results are shown in Table 3.

[Table] Example 3 (Wastewater treatment part 2) Showing the effect of treating diethanolamine-containing wastewater using the wastewater treatment material according to the present invention (dynamic adsorption effect) (1) Adsorbent: a○ Contains anionic groups Urethane foam b○ Normal urethane foam (2) Adsorption column used: Diameter 2.8cm, height 40cm (packing height) (3) Adsorbent packing density: 0.1g/cm ³ (28g) (4) Water flow rate: 1 m/H (downward flow) (5) COD analysis method: Oxygen consumption by potassium permanganate at 100°C Table 4 shows the so-called dynamic adsorption results performed by the above method.

[Table] As shown in the examples above, the method for producing the polyurethane foam of the present invention is extremely simple, and the polyurethane foam produced according to the present invention can be used as a wastewater treatment material to remove a trace amount of substances having cationic groups. Even in wastewater containing wastewater, the present invention allows the anionic groups necessary as a wastewater treatment material to be easily introduced into the molecular skeleton during the manufacturing process, which chemically adsorbs cationic group-containing substances and The fine cell structure of the open-cell polyurethane, which is unique to the wastewater treatment material of the invention, physically adsorbs and collects wastewater, and wastewater can be easily treated due to the synergistic effect of so-called chemical adsorption and physical adsorption. . Moreover, in the manufacturing method of the present invention, a soft or semi-hard urethane foam can be manufactured by arbitrarily selecting the three main components a, b, and c.
In addition, in order to select the ionic group content concentration from 0.5 to 10% by weight, it is only necessary to select component c appropriately, and the foam obtained by this method is extremely easy to process from the foamed slab, and waste water The treatment material can be processed into any shape such as powder, chips, plate, prismatic, cylindrical, etc., and can be processed into any shape suitable for the wastewater treatment method, such as adsorption tower method, filtration method, belt method, etc. Alternatively, it can be processed into the optimal shape for each method, such as an adsorption mat method in a wastewater pit. This is one of the features of the treated material obtained by the manufacturing method of the present invention, which is not found in other treated materials or adsorbents. Therefore, its application fields are wide, such as dyeing wastewater, plating wastewater, fishery processing wastewater, and other metal chemical processing wastewater. It is also possible to use the anionic group-containing polyurethane foam and the cationic group-containing polyurethane foam produced according to the invention in series.

Claims (1)

[Scope of Claims] 1. In producing an anionic group-containing polyurethane foam for wastewater treatment material having soft or semi-rigid open cells with an ionic group content concentration of 0.5 to 10% by weight, component a: polyfunctional polyurethane foam. Oxyalkylene polyol Component b: aliphatic or aromatic polyisocyanate alone or a mixture thereof, component c: having a carboxylic acid group or sulfonic acid group that can act as an anionic group (acidic group), and containing the above-mentioned organic A chain extender having 1 to 3 active hydrogens capable of reacting with a polyisocyanate component, an anion for wastewater treatment materials characterized by blending the above three main components a, b, and c and mixing and stirring to react. Method for producing group-containing polyurethane foam. 2. A method for producing an anionic group-containing polyurethane foam for wastewater treatment materials as set forth in claim 1, characterized in that the isocyanate index is 100 to 110 and the specific gravity of the polyurethane foam is 0.02 to 0.10.