WO2007113826A2

WO2007113826A2 - Hydrophobic formulations

Info

Publication number: WO2007113826A2
Application number: PCT/IL2007/000431
Authority: WO
Inventors: Yoram Tsivion
Original assignee: Future Tense Technological Development & Entrepreneuship Ltd.
Priority date: 2006-04-03
Filing date: 2007-04-01
Publication date: 2007-10-11
Also published as: AU2007232075A1; WO2007113826A3; GB0606617D0

Abstract

Tetra ethyl ortho silicate (TEOS) was found to be a useful formulating agent for relatively hydrophobic agents. Phosphorous acid is dispersible in TEOS whereas anhydrides of phosphoric acid and boron are soluble in TEOS to some extent. Potassium hydroxide is also soluble in TEOS. Some surfactants are soluble in TEOS. TEOS is a useful formulating agent for agricultural chemical agents.

Description

HYDROPHOBIC FORMULATIONS

FIELD OF THE INVENTION

5 The present invention relates to the formulating of chemicals. More specifically the invention relates to hydrophobic formulations.

BACKGROUND OF THE INVENTION

Formulating agents are used in the preparation of active products to be io administered to target objects such as organs and crops. In agriculture, often, the chemical agents to be applied to the crops are distributed carried by water ejected from a sprayer. The active agents can be hydrophobic to various extents, and in such cases the intervention of a formulating agent is required to assist the active agent in dispersing in the aqueous carrier.

15.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Tetra ethyl ortho silicate (also known as silicic acid tetra ethyl ester, tetra ethyl silicate, or ethyl silicate) is a common product used for weatherproofing and in several industries as a source of silicon and silicate. 0 Tetra ethyl ortho silicate, hereinafter referred to as TEOS, is very sparingly soluble in water, and is decomposed in water (The Merck index, eleventh edition, ethyl silicate). The decomposition occurs as the ester bonds between the silicate and the ethyl residues are hydrolyzed. The resulting products are silicic acid and ethanol. In accordance with the present invention, TEOS is used as a formulating agent for various active substances as in the agricultural practice. The usefulness of TEOS as a formulating agent for agricultural use is described hereinafter in several examples. Primarily, however, it was found that TEOS supplied by Sigma Aldrich as such was easily and homogeneously dispersed in water. For example, 0.5 millilitres (mis) of TEOS mixed in a 100 mis of water form a homogeneous and stable white suspension for the duration of hours. Further examples including useful chemical agents are described next.

Example 1

Phosphorous acid is used for fertilising, and for the control of several diseases in crops. Five grams of phosphorous acid, 99%, (supplied by Sigma

Aldrich) was mixed with 40 mis of TEOS, and stirred vigorously for one day. At the end of the stirring period, a milky white suspension formed. The suspension would settle slowly, and after a few hours of rest, the suspended particles would settle completely. The settled suspension would be re-suspended by shaking at any time during at least a year after settling, without any apparent loss of dispersibility.

Example 2 To 40 mis of TEOS 14 mis of Agral^® 90 (nonyl phenoxy polyethoxy ethanol), hereinafter referred to as Agral wetter, were added until fully dissolved. The solution was stable for a year at least.

Example 3

To the product of sample 2, three mis of Silwet L77 wetter were added and forming a stable clear solution.

Example 4

To the product of example 1 , 14 mis of Agral wetter were added, fully dissolving in the clear fraction.

Example 5

Boron in several forms is used for fertilising crops. Forty mis of TEOS were mixed with 5 grams of boron oxide (B₂O₃) (by Sigma Aldrich). The mixture was stirred vigorously for two days at room temperature forming a homogeneous clear solution. The solution was stable for at least 6 months.

Example 6

Twenty mis of TEOS were mixed with 3 grams of phosphorous pentoxide (P₂O5 ) (by Sigma Aldrich). The mixture was stirred and heated to 8O⁰C for an hour until a stable clear solution formed.

Example 7 To the product of example 6 10 mis of Triton^®X 100, a non ionic surfactant were added, forming a clear solution, which was stable for at least three months.

Example 8

Forty mis of TEOS were mixed with 3 grams of pyrophosphoric acid

(by Sigma Aldrich). The mixture was stirred and heated to 8O⁰C for an hour until a slightly hazy solution formed which was stable for at least two days.

Example 9

To 10 grams of TEOS were added 2 grams of polyphosphoric acid (by Sigma Aldrich). After two hours of vigorous mixing at room temperature a rather clear solution was obtained. Notably, the mixing of polyphosphoric acid is better than that of pyrophosphoric acid.

Example 10

To 10 grams of TEOS were added 2 grams of technical grade potassium hydroxide (KOH), after two hours of mixing at room temperature, a clear solution was obtained. The solution was stable for at least a year.

Phytotoxicity

To examine the effect of TEOS as a formulating agent for agrochemicals, the TEOS and various mixtures thereof were sprayed onto plant leaves. To water, 0.5 millilitre of the product of example 2 was added, mixed, and then sprayed on tomatoes, petunia and roses. No phytotoxic effect was observed within about two weeks. To water, 0.5 millilitres of the product of example 3 was added and mixed, and then sprayed on tomatoes, petunia and roses. No phytotoxic effect was observed within about two weeks. To water, 0.5 millilitres of the product of the well - shaken example 4 was added and after mixing sprayed on tomatoes, petunia and roses. No phytotoxic effect was observed within about two weeks. To water, 0.5 millilitres of the product of example 6 was added and mixed, and then sprayed on tomatoes, petunia and roses. No phytotoxic effect was observed within about two weeks. To water, 0.5 millilitres of the product of example 5 was added and mixed, and then sprayed on tomatoes, petunia and roses. No phytotoxic effect was observed within about two weeks.

Usefulness of the novel formulating agents and novel formulations

It was found that TEOS, a hydrophobic liquid, is dispersible in water and is not harmful to plants when sprayed at 0.5% (volumetric) concentration. TEOS was found to be miscible with certain well recognised surfactants utilised in agriculture (Agral wetter and Silwet L-77 wetter) and other surfactants used in miscellaneous fields of technology (Triton X 100). It was found that it is possible to dissolve or disperse the nutritive elements, phosphorus and boron in oxidised but less hydrated forms than customarily employed in agriculture. Thus boron oxide is considered sometimes as the anhydrous boric acid, and phosphorous acid is a form of phosphorus oxide which contains one less hydroxide as compared to phosphoric acid. Both boric acid and phosphoric acid are administered to plants for fertilising. The usefulness of TEOS is therefore in the formation of combinations with agents for storage or application. Phosphorous acid can be oxidized to phosphate in water, and in the storage in TEOS it is maintained seemingly fit for spraying, unchanged.

Experimentally, the addition of regular phosphoric acid to TEOS does not provide a useful solution or suspension, which is explainable due to the elevated hydrophilic nature of phosphate. The miscibility of pyrophosphate and polyphosphate in TEOS is explainable due to their reduced hydrophilic nature.

However, this explanation contradicts the good miscibility of KOH with TEOS.

Claims

1. A liquid composition consisting of tetra ethyl ortho silicate (TEOS) containing useful chemical agents

2. A composition as in claim 1 containing also at least one surfactant.

3. A composition as in claim 1 wherein said composition is a solution.

4. A composition as in claim 1 wherein said composition is a suspension.

5. A composition as in claim 1 containing a surfactant and phosphorous acid.

6. A composition as in claim 1 containing phosphorus oxide.

7. A composition as in claim 1 containing boron oxide.

8. A composition as in claim 4 containing phosphorous acid.

9. A composition as in claim 1 containing also pyrophosphoric acid.

10. A composition as in claim 1 containing also polyphosphoric acid.

11. A composition as in claim 1 containing also potassium.

12. A method for preparing hydrophobic formulations using tetra ethyl ortho silicate (TEOS) as a formulating agent.

13. A method for preparing hydrophobic formulations using tetra ethyl ortho silicate (TEOS) as in claim 12 wherein potassium hydroxide is used as a source of potassium.