JPH0459614A - Aqueous solution of silicic acid at ph5-7 - Google Patents

Abstract

PURPOSE:To obtain a neutral aqueous solution of silicic acid containing the silicic acid at a high concentration by adding a specific solubilizing agent to a silicate. CONSTITUTION:One or two or more solubilizing agents selected from ethylene glycol, glycerol, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soybean protein hydrolyzed multiple amino acids and urea are added to an aqueous solution of a silicate and the pH is then regulated to 5-7 with an acid. The weight ratio of the silicate: solubilizing agents is preferably (1:0.1)-(1:1.0). If the aforementioned silicic acid solution is used as a fertilizer, the silicate used is preferably a potassium salt and the acid for regulating the pH is preferably phosphoric acid.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides an aqueous solution containing a high concentration of silicate showing p) 15 to 7, and a highly concentrated silicate containing trace components necessary for plant growth. It relates to aqueous solutions.

(Prior art) Silicic acid promotes the activity of plant roots and the assimilation of ammonia nitrogen, and not only improves nitrogen tolerance and resistance to adverse environments, but also affects fertility and abnormal symptoms during the reproductive growth period. has been clarified and is recognized as a fertilizer, but silicic acid present in soil solution is generally the source of plant silicon. For example, when sodium silicate dissolves in water, it exists separated into positively charged sodium ions and negatively charged silicate ions, and the solution is alkaline. When this is neutralized with an acid, the silicate ion loses its charge and becomes molecular silicic acid. When the concentration of molecular silicic acid becomes high, it aggregates in a solution and comes to exist in a molecularly dispersed state, and when it is further concentrated, it comes to exist in a sol state. On the other hand, it has been shown that plants absorb molecular silicic acid in soil solutions, and that they absorb silicic acid best in neutral or slightly acidic solutions. However, the saturation concentration of molecular silicic acid in neutral conditions is only 120 to 140 μ/l, and generally soil solutions are 30 to 40 μ/l! It is said that it contains molecular silicic acid. Therefore, it is impossible to rapidly apply the required amount of silicic acid to plants at the time when they need it, or to arbitrarily adjust the addition of silicic acid.

In addition, there are plants in which the absorption of silicic acid is poor and the effect is difficult to manifest unless the silicic acid concentration is 100 mg/f or more. If a highly concentrated neutral solution of silicic acid can be replaced in this way, it is expected that the applications of silicic acid fertilizers will expand.

(Problems to be Solved by the Present Invention) The first object of the present invention is to provide a silicic acid solution that is neutral and contains high concentration of silicic acid, and is further useful as a fertilizer containing plant nutrients, especially as a foliar fertilizer. The second objective is to provide a silicic acid-containing solution.

(Means and effects for solving the problem) Water-soluble silicates dissolve in water and exhibit alkalinity. Are these alkaline waters? As a method of preventing gelation of silicates of g f&, gelation inhibitors selected from acrylic acid polymers, their metal salts, lime alcohol, water-soluble salts of tungstic acid, molyphdic acid, and selenic acid, and ethylene glycol, etc. A method of adding alcohol is described in US Pat. No. 4,487,712. However, as mentioned above, it has been revealed that silicic acid is neutral or weakly acidic and is absorbed by plants as molecular silicic acid. Since molecular silicic acid has significantly different properties from silicate ions, the above US patent cannot be applied to molecular silicic acid. As a result of various studies, it was recognized that a highly concentrated neutral silicate aqueous solution could be stably produced by adding certain proteins, amino acids, diols, and triols to silicate, or by solubilizing molecular silicic acid. .

That is, the present invention uses one or more solubilizing agents selected from ethylene glycol, glycerin, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soybean proteolytic synthetic amino acids, and urea. Contains, pH 5-7
silicic acid aqueous solution, and silicate aqueous solution containing one or more types selected from ethylene glycol, glycerin, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soybean proteolytic integrated amino acids, and urea. By adjusting the pH to 5-7 with an acid after adding the solubilizing agent,
This is a method for producing an aqueous silicic acid solution having a pH of 5 to 7.

The silicates mentioned here include silicates such as alkali ortho-silicic acid, alkali meta-silicic acid, alkali tetra-silicic acid, and alkali silicic acid, and the present invention will be explained below using sodium ortho-silicate as an example.

Sodium orthosilicate (2Na, O・5iOz・nH
zo) When an acid is added to a 0.5% aqueous solution to adjust the pH of the solution, the solutions adjusted to pH 3, 4, 8, 9, and 10 do not produce precipitation even after 13 days, but the solutions with pH 5, 6 The solution adjusted to pH 7 immediately forms a precipitate and becomes cloudy, and the white turbidity is most significant at pH 6. That is, at neutral pH, silicic acid exists with the minimum solubility as molecular silicic acid, and this leads us to believe that silicic acid is dissolved in different forms on the acidic side and the alkaline side. The present invention is neutral or acidic, i.e. pi(5
Since the aim is to obtain a highly concentrated solution of molecular silicic acid with a pH of around 7.5%, various substances are added as solubilizers to a 0.5% sodium orthosilicate aqueous solution, and the pH is adjusted to 5-7 with an acid. The solubilizing power was measured as the time it took for the crystals to precipitate after being left at room temperature, and it was thought that the longer the time, the stronger the solubilizing power. First, the amount of solubilizing substance added to sodium orthosilicate is adjusted from 10% to 100% by weight.
We measured the time until the crystals precipitated at pH 1, and found that the solubilizing power may differ somewhat depending on the amount of the solubilizing substance added.
% to 20% was considered to be sufficient, so subsequent measurements were carried out by adding 10% by weight of the solubilizing substance to the silicate.

These crystals include diols such as ethylene glycol, diethylene glycol, dipropylene glycol, triols such as glycerin; proteins such as casein or gelatin; and arginine.

It was found that amino acids such as histidine, L-glutamic acid, soybean proteolytic integrated amino acids, and urea have solubilizing power. These solubilizing substances generally have a low solubilizing power at pH 6, and their solubilizing powers at pH 5 and 7 are somewhat higher than that at pH. However, gelatin among the above substances is unique in that it does not exhibit solubilizing power at pH 5, but has particularly excellent solubilizing power at pH 6, and dipropylene glycol has extremely excellent solubilizing power at pH 7. The growth of the precipitated crystals is slow and the emulsion continues, making it difficult for the crystals to be deposited.

The silicate solution with pH 5-7 obtained by this method is stable;
Even when trace components essential for plant growth, such as iron-zinc, calcium, magnesium, and organic complexes of other metals, are added to the obtained silicate solution, silicic acid does not precipitate.

Therefore, silicate solutions to which trace amounts of essential metal complexes have been added are extremely effective as fertilizers, especially foliar fertilizers. In this case, the amount of metal complex added is generally sufficient at a concentration used as a foliar fertilizer, and the chelating agent used for the metal complex is ED
These include TA, polyphenolic acid, lignosulfonic acid, citric acid, and amino acids. When the silicic acid solution of the present invention is used as a fertilizer, it is natural that the silicate used is preferably a potassium salt, and the acid for adjusting pH is preferably phosphoric acid.

(Example) EXAMPLES The present invention will be specifically described below with reference to Examples.

<Example 1> Sodium orthosilicate (2NazO・5iOz・nHzo
) Add dipropylene glycol to the 0.5% solution and
The pH was adjusted to 7.0 with Cfi, the mixture was left at room temperature, and the number of days until crystals precipitated was measured, and the results shown in Table 2 were obtained.

Table I Table■ <Example 2> Various solubilizers were added to a 0.5% sodium orthosilicate solution, the pH was adjusted to 5 and 6.7 with HC/2, respectively, and crystals were precipitated by standing at room temperature. We measured the number of days it took to do so. The results are shown in Table ■.

Note 1: The numbers in the table are the number of days until crystals precipitate2.
The prepared filtrate was tested.

<Example 3> Frewat Fe (content 13.5-13.7%) and Frewat Zn (content 15.4) chelated with EDTA in a 0.5% sodium orthosilicon and 0.2% dipropylene glycol solution ~5-7%), Flewat C
a (content 3.8-4.1%) and Frewat Mg
(Content: 2.2-2.4%) (Kurewasoto metals manufactured by Teikoku Kagaku Sangyo ■) were added to the respective metal concentrations shown in Table I [1-(1) to (4), The pH was adjusted to 7.0, and the number of days until crystals precipitated after being left at room temperature was measured, and the results shown in Table I [1-(1) to (4)] were obtained.

Table I [1-(2) Watercress Table II [-(3) In case of addition of Flewarat Zn In case of addition of Ca ~ (1) In case of addition of Tarewat Fe Table 1111-(
4) Reference example 1 in case of addition of Flewalato Mg> Sodium orthosilicate 0.5%, 1%, 1.5% and 2
0.2% dipropylene glycol was added to each solution, the pH was adjusted to 7.5, 8.0, and 9.0 with HCl, and the number of days until crystals precipitated after being left at room temperature was measured. . The results are shown in Table ■.

The result of (2) was obtained.

Table V-(1) When ammonium sulfate is added Table V-(2) When phosphoric acid-potassium is added <Reference Example 2> Ammonium sulfate is added to each of 0.5% sodium orthosilicate and 0.05% dipropylene glycol solutions. and phosphoric acid-potassium are both 0. Add OOl, 0.01, 0.1 and 1%, adjust the pH to 7.00 with HCl2, leave it at room temperature and measure the number of days until crystals precipitate. 1: Marked *1 in Table V-(1) indicates that a white precipitate was formed after the addition of phosphoric acid (Reference Example 3) Both ammonium sulfate and potassium phosphoric acid were added to each of the 0.5% sodium orthosilicate and 0.05% urea solutions. 0.00
Add 1, 0.01, 0.1 and 1% and pH with HCl.
was adjusted to 7.00 and left at room temperature to measure the number of days until crystals precipitate. As a result, the same results as in Example 5 were obtained.

(Effects of the Invention) The solubilizer according to the present invention is effective even when the pH of the silicate solution is 7 or more, and stabilizes the highly concentrated silicate solution and prevents silicate precipitation. The addition of solubilizers according to the invention can be used as stabilizers of silicate solutions over a wide pH range.

Procedural amendment July 30, 1990 Director General of the Patent Office Satoshi Uematsu1, Indication of the case Patent Application No. 2-1667472, Name of the invention silicic acid aqueous solution with pH 5 to 73, Person making the amendment Relationship to the case Patent applicant name: Akama 4, Ltd., agent: 105 ff103 (43]) 1831 Address:
Mori Building, 40 Toranomon, 5-13-1 Toranomon, Minato-ku, Tokyo Name (6538) Patent attorney Tsumi Yamashita P5, subject to amendment
-1- Contents of amendment in Column 6 of Detailed Description of the Invention in the Specification (1) "Crystal" in line 3 of page 7 of the specification is corrected to "result".

(2) Correct r pHJ on page 7, line 11 of the specification to rpH6J.

Claims (4)

[Claims] (1) One or two selected from ethylene glycol, glycerin, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soybean proteolytic integrated amino acids, and urea.
An aqueous silicic acid solution containing at least one solubilizer and having a pH of 5 to 7. (2) Silicate: Solubilizer in a weight ratio of 1:0.1 to 1:1
．． The silicic acid aqueous solution according to claim 1, wherein the silicic acid aqueous solution is 0. (3) Claim 1 containing one or more complexes selected from complexes of iron, zinc, calcium, and magnesium.
Or the silicic acid aqueous solution according to 2. (4) One or more solubilizing agents selected from ethylene glycol, glycerin, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soybean proteolytic integrated amino acids, and urea in the silicate aqueous solution. A method for producing a silicic acid aqueous solution having a pH of 5 to 7, by adding , and then adjusting the pH to 5 to 7 with an acid. (5) The method for producing a silicate aqueous solution having a pH of 5 to 7 according to claim 4, wherein the solubilizer is added in a weight ratio of silicate:solubilizer of 1:0.1 to 1:1.0.