JPS5951967A - Sequestering agent - Google Patents

Abstract

PURPOSE:To provide a high-quality sequestering agent excellent in biodegradability, well suited for use in detergent builders, etc., by incorporating an isotactic poly[(meth)acrylic acid] having a specific average MW or its salts as an active component. CONSTITUTION:Isotactic poly(methacrylic acid) having an average MW of 500- 10,000 or isotactic poly(acrylic acid) having an average MW of 500-50,000 is prepd., e.g., by polymerizing methyl (meth)acrylate in the presence of phenylmagnesium bromide in a solvent such as dry toluene. The intended sequestering agent is yielded by incorporating an alkali metallic salt or amine salt of the resulting isotactic poly[(meth)acrylic acid]. The sequestering agent is well suited for waste-water treating agents, detergent builders, removers of boiler scales, etc.

Description

[Detailed description of the invention] The present invention relates to phosphorus-free sequestering agents.

Contained in industrial wastewater or soil discarded from various German industries such as mines, refining factories, metal processing plants, and textile factories.
Various metal ion sequestering agents are known as a means of removing harmful heavy metals, such as condensed phosphates and polyamine condensates of late acrylic esters. however,
These have drawbacks such as being expensive because they require complicated manufacturing processes, and requiring a large amount of neutralizing agents, which limits the processing range because the pH range is on the high alkaline side. .

Currently, when preparing a detergent containing a surfactant as a main component, it is important to use a pill composition as an auxiliary component to the main active ingredient in order to improve the detergent performance.

Inorganic salts that exhibit alkalinity when dissolved in water are generally known as horse mackerel detergent builders and pear scales. These include carbonates, bicarbonates, phosphates, condensed IJ4' salts, silicates, borates, etc. of alkali metals, especially sodium and potassium.

Also, when made into a stock solution, complex compounds,
Alkali metal groups of organic carboxylic acids that form chelate compounds, ammonium salts, mono-di-triethanolamine salts, etc., such as nitrilotriacetate, ethylenediaminetetraacetate, citrate, succinate, tartrate, fumar Acid salts, maleate salts, glucosic acid salts, etc. are also known as birch salts.

Furthermore, polymerized aliphatic polycarboxylic acid salts are known to be effective as virgoos. These include polymaleic acid, polyitaconic acid, 71Vfin-
Salts of maleic acid copolymers, salts of alkyl vinyl ether/maleic acid copolymers, and the like are known.

Among these many virgoo compositions, phosphate, Ah
Compound II# acid salt is the most effective and is used in large quantities. The amount of other compounds to be used is limited in terms of positive results, workability, safety, etc., and currently they are not used except in special cases.

However, when phosphates and condensed phosphate builders are discharged as wastewater after trenching, they flow into lakes and rivers, promoting algae growth and causing eutrophication. Builders that do not include this groove are being developed, and many builders have been proposed.

For example, polymer electrolytes have poor biodegradability and have not yet achieved the same level of effectiveness as sodium tripolyphosphate. In addition, compounds containing nitrogen have recently been reported, but nitrogen, like phosphorus, is a source of eutrophication and is therefore undesirable.

The present inventors have been conducting intensive studies to find a metal ion sequestering agent with excellent biodegradability that can replace phosphates and Inai phosphates. Tactical poly(methacrylic acid) or average molecular weight 500
The inventors have discovered that interactive poly(acrylic acid) having ~s o, o o o, or their alkali metal or amine salts are biodegradable and have excellent performance as metal ion sequestering agents, and have thus arrived at the present invention. .

Is the sequestering agent used in the present invention as a detergent builder equivalent to or more effective than phosphorus builders such as sodium tripolyphosphate? Not only can it be used alone, but it can also be used in combination with a phosphorus-based builder to reduce the amount used, and it is also possible to reduce the amount of activators mixed together.

Furthermore, the sequestering agent of the present invention is extremely effective in preventing the formation of scale in boilers and the like and in removing the formed scale.

Furthermore, the metal ion pricking agent of the present invention is also extremely useful for the decontamination treatment of soil A contaminated with harmful metals.

Furthermore, the sequestering agent of the present invention can be used in products whose decomposition and deterioration are accelerated due to the presence of trace amounts of metal ions; It is also effective for stabilizing plastics, etc., and can also be used as an electrolyte for air plating.

Moreover, since the sequestering agent of the present invention has good biodegradability, the environment will not be polluted by the waste water and wastewater used for the above-mentioned purposes.

In the present invention, isotactic poly(methacrylic acid) or isotactic poly(acrylic acid) salts (1) may be used as alkali metals such as sodium, potassium, and lithium; as amines, ammonia, mono-, di- Alternatively, triethanolamine, morboline, etc. may be used, and these salts may naturally be partial salts.

The molecular weight of the intact poly(methacrylic acid) or its salt ranges from about 500 to 10,000, preferably from aoo to 7,000, most preferably from 1,000 to 5,000; The molecular weight range of poly(acrylic acid) or its salt is about 500 to so, ooo
and preferably 800 to 30,000 1,
Most preferably, the range is from 000 to 20,000. Further, the poly(methacrylic acid) and poly(acrylic acid) (salt) of the present invention may be a copolymer of both.

In addition, isotactic poly(methacrylic acid) (salt) or intact poly(acrylic) (
m) is preferably a homopolymer, but may also be a copolymer with a small proportion of other comonomers that can be co-merged.

Examples of the comonomer include maleic anhydride, methyl vinyl ether, vinyl acetate, vinylpyrrolidone, itaconic acid, aconitic acid, citraconic acid, fumaric acid,
Examples include styrene, butadiene, imprene, etc.

The compound of the present invention can be blended with either an anionic activator or a nonionic activator, and can be arbitrarily blended with various known activators regardless of their type. The compounds can be used alone as detergent builders or in combination with inorganic or organic pond builders. For example, it can completely or partially replace a phosphorus-based builder such as sodium tripolyphosphate. Moreover, even if it coexists with various compounds that are commonly added to the cleaning composition, its effectiveness will not be impaired in any way.

The amount of the compound of the present invention added to the detergent composition is not particularly limited, and a sufficient effect can be obtained with the same amount of 1 & 2 as the general builder loading.

Hereinafter, according to synthesis examples and practical examples of compounds according to the present invention, υ
The present invention will be explained. It should be noted that the term r % J simply means ``heavy lid person'' unless otherwise specified.

Synthesis Example 1 Synthesis of Inotactic Poly (sodium methacrylic acid) (hereinafter abbreviated as t-PMA) Dried in a flask equipped with a stirrer, a thermometer, a nitrogen inlet pipe and an exhaust pipe, and a sample inlet with a syringe cap. Under the conditions shown in Table 1 while flowing nitrogen, dry toluene and a 3.2M phenylmagnesium bromide/ether solution were weighed out, and methyl methacrylate (MMA) was added using a syringe while stirring while keeping it at -5 to 2°C. The mixture was injected and the reaction was carried out at this temperature for 24 hours. Next, methanol was gradually added to stop the polymerization, and the reaction mixture was added to 8% hydrochloric acid (1j) with stirring, and the precipitated white oligomer was vacuumed and dried.

Next, dissolve in 150 mJ of acetone and remove insoluble matter.

Then, the p solution was poured into 8 qb hydrochloric acid (1 NO) to remove the catalyst component in the oligomer. Next, the precipitated oligomer was washed with water,
Furthermore, a coffin was made by repeating the process of dissolving the oligomer in a small amount of acetone, then pouring it into a large amount of water and reprecipitating it. The obtained oligomer was dried under reduced pressure at 60°C to obtain isotactic poly(methyl methacrylate) ( PMMA
) was obtained. pM for methyl ester by vPO method
n was determined, and the molecular structure was further confirmed by engineering R, elemental analysis, and NMR. Next, the mixture was heated and saponified with 1.5 times the equivalent of 20% sodium hydroxide at 130° C. for about 3 days to obtain ■tl PMA.

Incidentally, the molecular weight of -PMA was calculated from the molecular weight of the corresponding methyl ester. The synthesis conditions, conversion rate, and analysis results are shown in Table 1.

Synthesis 2 Synthesis of isotactic poly(sodium acrylate) (hereinafter abbreviated as It-FA) Methyl acrylate (MA)'i
Phenylmagnesium bromide (PhM) is used as an anion catalyst.
gBr ) or lithium tetrahydride aluminate (h
iA, g) ill) s Solution-covered polymerization was carried out at low temperature using dry toluene as a solvent, and the reaction was stopped by adding methanol. The reaction mixture was poured into methanol acidified with hydrochloric acid and stirred to decompose the catalyst components. Thereafter, fractional precipitation was performed to separate oligomers with the desired molecular weight. In order to remove the catalyst component from the oligomer, the process of dissolving it in acetone, filtering it, condensing the solution, pouring it into a large amount of water and reprecipitating it was repeated.The oligomer made of silk was dried under reduced pressure at 60°C. Isotactic poly(methyl acrylate) (PMA) was obtained.These methyl esters were subjected to elemental analysis and NMR structure confirmation.Next, the methyl esters were diluted with 1.2 to 2.
The product was saponified by heating with a 0% aqueous sodium hydroxide solution for 24 hours or more, dissolved in a small amount of water, and poured into a large amount of ethanol to be reprecipitated repeatedly to make cloth. Drying was carried out under reduced pressure at 100° C. to obtain a t-FA having almost the theoretical capacity.

In the same manner, the molecular weight of t-FA was converted from the molecular weight of the corresponding methyl ester. Synthesis conditions and analysis results are shown in Table 2.

In the cleaning power test, cotton face-agga (1A) contaminated cloth was used as the naturally contaminated cloth, and the judgment was made using Bahθffe o paired comparison method 4
A visual inspection was performed, and for comparison, commercially available sodium tripolyphosphate and sodium oxadiacetate were also tested each time.

The washing conditions and detergent composition are as follows.

1) Washing detergent a, #0.12 Washing temperature 25℃ Washing time 11JL 8 minutes use Washing machine x Garden spiral type electric washing Isoba Ratio
1:3.

1. Historical water 3°DB tap water 11) Rinse water Temperature: 25°C Rinse time using washing machine: 3 minutes 111) Detergent composition sample builder Section 25, No. 2 Sodium silicate 5 qb Anhydrous sodium carbonate 3 Thicarboxymethyl cellulose (OMO) 0. 59
6 Anhydrous Sodium Sulfate 46.5% The results of the detergency test are shown in Table 3.

In the same evaluation, the effect of sodium oxadiacetate was set as 0 and the effect of sodium tripolyphosphate as 10.

It is a thing.

Example: In a 50 d beaker equipped with a rotor, remove 10 sample builders and add 1. Dissolve 50*l of OX 10M calcium chloride aqueous solution, add 1 me of 4.0M potassium chloride water bath solution as an ionic strength t3 adjuster to adjust the ionic strength μ=0.08, and place in a constant temperature bath at 30℃. After stirring, the calcium ion strength after 10 minutes was measured using a calcium ion electromagnetic image (Orion MODJICL 95-20).
Using an ion meter (Toa Kamegi Kogyo KK Kogyo M, -
20Et), and the calcium ions sequestered by sample builder 12 were expressed as calcium carbonate true values. The results are shown in Cloth-4.

Table 4 Calcium ion sequestering ability Example 3 1. Using 0 and 11/7 aqueous solutions of each sample. Tl5K01
A biodegradability test was conducted according to 02.

The results are shown in Table-5.

Table 5 Biodegradability Test *1 Heterotactic poly(sodium acrylic) with average molecular weight 7000 $2 Poly(sodium 2-hydroxyacrylate) with average molecular weight 370 Samples shown in Example Table 6 A washing power test was conducted in the same manner as in Example 1. Further, the dispersion power of manganese dioxide was evaluated by the method shown below. The results are shown in Table-6.

<Manganese dioxide dispersion force evaluation method> 50mJ scaled co-separation test/U, manganese dioxide 1
．． After removing 50 d of a 0.05% aqueous sample solution and digging up and down 100 times, it was left to stand in a constant temperature bath at 25° C. for 4 hours. Next, 15 m/ml of the suspension was collected without disturbing the test results as much as possible. The manganese dioxide member in the collected suspension was measured by the potassium permanganate method. The dispersion power was expressed by the town administration of manganese dioxide that was left standing in 100 yxe of liquid. The results are shown in Table 6.

Table 6 Detergent power and manganese dioxide dispersion power *1: Heterotactic poly(sodium acrylate) with average molecular length of 920: The same applies to other FAs.

Example 5 Using 0.11/l aqueous solution of each sample, JIS K01
A biodegradability test was conducted according to 02.

The results are shown in Table-7.

Table 7 Biodegradability Test Example 6 In order to examine the effectiveness of the sequestering agent of the present invention as a soil treatment agent, the following test was conducted using cadmium-contaminated soil. A ±1 face contaminated with 20 ppm cadmium was exposed to a direct i10 (2M cylinder with 1m light filling, 0.0596
A metal ion sequestering agent aqueous solution of 10,100 O' was flowed. The amount of cadmium in the contaminated soil was then measured. The results are shown in Table-8.

Table 8 Example: In order to examine the scale prevention effect of the sequestering agent of the present invention, a sequestering agent (t-PMA-2120) was dissolved in boiler water to a concentration of 10 ppm, and the sequestering agent (T-PMA-2120) was dissolved for one year. I drove.

As a result, no scale was observed.

Claims (1)

[Claims] Poly(methacrylic acid) with an average molecular weight of 500-10,000 or an average molecular weight of 500-s
A metal ion chaining agent containing as an active ingredient an isotactic polybiacrylic acid having the following: