Synthesis of dimer acid based oil emulsifier for oil dispersion formulations

Abstract

The invention relates to the synthesis of an oil emulsifier for use in oil dispersion (OD) type formulations, one of the pesticide applications. In particular, the invention relates to a dimer acid-based oil emulsifier which can be substituted for the ethoxylated castor oil-based oil emulsifier used in oil dispersion (OD) formulations.

Description

[0001] Synthesis of Dimer Acid Based Oil Emulsifier for Oil Dispersion Formulations

[0002] Technical Area

[0003] The invention relates to the synthesis of an oil emulsifier for use in oil dispersion (OD) type formulations, one of the pesticide applications.

[0004] In particular, the invention relates to a dimer acid-based oil emulsifier which can be substituted for the ethoxylated castor oil-based oil emulsifier used in oil dispersion (OD) formulations.

[0005] State of the Art

[0006] An oil dispersion (OD) is a stable suspension of active ingredient(s) in an organic liquid, which may contain other dissolved active ingredient(s), intended to be diluted with water before use.

[0007] Oil dispersions (OD) in agrochemicals help to utilize various agrochemical active ingredients such as pesticides, fungicides and herbicides in agricultural formulations. The oil component in this type of formulation helps disperse and dissolve the active ingredients, increasing their efficacy and ease of application. Oils also act as adjuvants (spreaders), allowing the formulation to penetrate and spread on plant surfaces and to be easily absorbed by the plant. The types of oil used in such formulations can be petroleum-based oils (e.g. paraffinic, naphthenic or aromatic oils), vegetable oils (e.g. soybean, canola, sunflower) or methylated seed oils (e.g. methylated soybean or rapeseed oil). However, vegetable oils are mostly used in OD formulations. OD formulations are usually emulsions or microemulsions in which the oil is dispersed in an aqueous phase. Emulsifiers are used to emulsify the oil. These emulsifiers stabilize oil dispersion. The oil content in agricultural formulations can typically range from 5 to 50 per cent, depending on the specific application and requirements.

[0008] Oil dispersions allow for better dissolution and dispersion of the active ingredients, as well as better spreading, wetting and absorption of the active ingredients on plant surfaces. At the same time, loss of active pharmaceutical ingredients due to evaporation is reduced and rain fastness is increased. Fatty acid esters of ethoxylated castor oil are used as oil emulsifiers in OD formulations. Such products are commercially available by companies. Products such as Alkamul’s V02003 of Solvay company, Toximul 8240 of Stefan company and Atlox 4914 of Croda company can be given as examples. Ethoxylated castor oil, which is the raw material from which these products are generally made, is easily commercially available. However, the ethoxylation process carried out during the production of this product is a troublesome process. During this ethoxylation, the ethoxylated chains are not in the same proportions and length, and at the same time, due to the nature of the reaction, the triester structure of castor oil may be disrupted. The product resulting from this reaction is a mixture of ethoxylated chains of different lengths. The fact that the product is a mixture makes it difficult to achieve the same properties at each production stage. For this reason, it is necessary to use a chemical substance that can be used instead of ethoxylated castor oil, and which is subjected to less change during its production. In the state of the art, there is no information on the use of such a structure in agrochemical formulations.

[0009] In the literature search, applications numbered JP7471022 and W02003106010 were found. Although there is a synthesis of dimer acid and peg in the related applications, this synthesis is carried out without esterification with free fatty acid. In addition, there is no mention of use in agrochemical formulations in these applications.

[0010] As a result, due to the above-mentioned negativity and the inadequacy of the existing solutions on the subject, it has become necessary to make a development in the relevant technical field.

[0011] Brief Description of Invention

[0012] The present invention is to provide a dimer acid-based oil emulsifier which fulfils the above- mentioned requirements, eliminates all disadvantages and brings some additional advantages, and can be substituted for ethoxylated castor oil-based oil emulsifier used in OD formulations.

[0013] The invention is inspired by the current situation and aims to solve the above-mentioned disadvantages.

[0014] The main object of the invention is to provide a product obtained from dimer acid modified with polyethylene glycol (PEG) to replace ethoxylated castor oil. One object of the invention is to synthesize an oil emulsifier whose chemical structure does not contain a mixture and to provide a product which can be used in OD formulations.

[0015] Another object of the invention is to provide a product which is more stable in water and gives a more effective oil emulsion.

[0016] The other object of the invention is to provide a product which serves the same purpose but has a different chemical structure, which will reduce the dependence on the generally accepted ethoxylated castor oil thanks to its structural and characteristic properties.

[0017] In order to fulfil the aforementioned objects, the invention is a dimer acid-based oil emulsifier for use in oil dispersion (OD) formulations, comprising dimer acid, polyethylene glycol, organic acid catalyst and unsaturated fatty acid.

[0018] In order to fulfil the above-mentioned objects, the invention provides a method of obtaining a dimer acid-based fat emulsifier for use in oil dispersion (OD) formulations, comprising esterification of dimer acid by reaction with polyethylene glycol and oleic acid under organic acid catalysis.

[0019] The structural and characteristic features and all the advantages of the invention will be more clearly understood with the detailed description given below, and therefore the evaluation should be made by taking this detailed description into consideration.

[0020] Detailed Description of the Invention

[0021] In this detailed description, the method of the invention is described solely for the purpose of a better understanding of the subject matter and without any limiting effect.

[0022] The invention relates to a dimer acid-based oil emulsifier to be used as a substitute for ethoxylated castor oil in an oil dispersion (OD) formulation. The dimer acid-based oil emulsifier of the invention comprises dimer acid, polyethylene glycol, organic acid catalyst and unsaturated fatty acids. The The dimer acid-based oil emulsifier of the invention preferably comprises Dimer Acid, polyethylene glycol, P-toluene sulphonic and oleic acid, and the usable and preferred amounts of the formulation by weight are given in Table 1 . Tablo 1 Bulu§ konusu yag emulgatdru formulasyonun reqetesi

[0023] The dimer acid-based oil emulsifier of the invention preferably comprising 15-50 wt. % dimer acid, 20-55 wt. % polyethylene glycol, 25-50 wt. % oleic acid as unsaturated fatty acid and 0.1 -2 wt. % P-toluene sulphonic as organic acid catalyst. The inventive emulsifier preferably comprises 29.1 wt. % dimer acid, 41 .3 wt. % PEG, 29.1 wt. % oleic acid as unsaturated fatty acid and 0.5 wt. % P-toluene sulphonic acid as organic acid catalyst.

[0024] The dimer acid in the dimer acid-based fat emulsifier formulation of the invention is preferably synthesized in unsaturated fatty acids. In one embodiment, the inventive dimer acid-based fat emulsifier comprises a hydrogenated and saturated form of the dimer acid.

[0025] The polyethylene glycol in the formulation of the inventive dimer acid-based fat emulsifier is preferably in liquid or solid form.

[0026] In the inventive dimer acid-based fat emulsifier, dimer acid is esterified by reacting with polyethylene glycol and oleic acid under organic acid catalysis. The organic acid catalyst mentioned herein is preferably p-toluene sulphonic acid.

[0027] Herbicides, pesticides and fungicides are used as active substances in agrochemicals. When these active substances are applied as oil dispersions, they show better spreading and better absorption properties on plant surfaces, as well as lower evaporation and lower rain exposure. The active drug substance, oil (usually soya, canola or sunflower oil) and oil emulsifier together form an oil dispersion type product. During the application, this oil dispersion is mixed with water and applied to the designated area in quantities suitable for the drug and plant species. The oil emulsifier here is synthesized in the form of glycerol ester of ethoxylated fatty acids. Today, the most widely used oil emulsifier is the fatty acid ester of ethoxylated castor oil. There is also a product called Alkamuls V02003 of Solvay company, which dominates the whole world market. As an alternative to this product, there is no product containing a different chemical formula. This invention focuses on this point.

[0028] In the invention, dimer acid, which is completely vegetable origin and biodegradable like castor oil, is used. Dimer acid is obtained by heating free fatty acids in the presence of clay catalysts and in nitrogen environment. In terms of its general structure, bifunctional molecules are formed. In addition to bifunctional carboxylic acid, small amounts of monofunctional and trifunctional acid molecules are also formed. If necessary, this mixture is separated and purified and hydrogenated to obtain a completely fused structure. In order to eliminate the irregularities in the ethoxylation of castor oil, dimer acid is reacted with polyethylene glycol (PEG), which is considered an ethoxylate polymer, readily synthesized and commercially available. The PEG to be used has different molecular weights and can be found in liquid and solid form. PEG products in liquid form (such as PEG 200, PEG 400, PEG 600) are preferred for ease of use and production, but which of these PEG products to use also depends on the stability of the final emulsion application. Unsaturated fatty acid (preferably oleic acid), which plays an active role in the functioning of the oil dispersion, is added to the same reaction medium and the esterification reaction is carried out in the presence of a suitable esterification catalyst. The use of saturated fatty acids instead of unsaturated fatty acids greatly affects the fluidity of the resulting product and causes crystallization of the drug by polarity incompatibility with some active drug substances used. Therefore, unsaturated fatty acids are used in the invention. The fatty acid used is preferably oleic acid. Other unsaturated fatty acids can be used instead of oleic acid, but this preference causes an increase in product cost. Because other unsaturated fatty acids are much more expensive than oleic acid. The esterification catalyst used in the reaction was chosen as p-toluene sulphonic acid, an organic acid catalyst. If different acid catalysts are selected, the reaction temperature, time and the amount of catalyst used also vary. The esterification catalyst used must be organic based to avoid any cleaning of the product at the end of the reaction. Therefore, inorganic catalysts are not used. The progress of the reaction is monitored by both the amount of water collected and the gradually decreasing acid number. The method of obtaining a dimer acid-based fat emulsifier according to the invention comprises the esterification of dimer acid by reaction with polyethylene glycol and oleic acid under organic acid catalysis.

[0029] The synthesis of the inventive dimer acid-based oil emulsifier comprises the following steps. i. Preparation of dimer acid, polyethylene glycol, organic acid catalyst and unsaturated fatty acid by weighing, ii. Providing esterification of dimer acid by heating the mixture to a temperature range of 80- OO'C under vacuum with stirring at normal stirring speeds (esterification of dimer acid by reacting with polyethylene glycol and oleic acid under organic based acid catalyst) ill. Monitoring the progress of the reaction and cooling the reaction when it reaches the desired level, iv. Removal of the synthesized oil emulsifier into a closed container

[0030] A preferred embodiment of the synthesis of the dimer acid-based fat emulsifier of the invention comprises the following steps.

[0031] Step 1 : Preparation of Dimer Acid, Polyethylene glycol, organic acid catalyst and unsaturated fatty acids in amounts determined in stoichiometric ratios by weighing,

[0032] It is preferably prepared by weighing Dimer Acid in the range of 15-50 wt.%, Polyethylene glycol in the range of 20-55 wt.%, oleic acid as unsaturated fatty acid in the range of 25-50 wt.% and P- toluene sulphonic as organic acid catalyst in the range of 0.1 -2 wt.%.

[0033] Step 2: All these chemicals are taken into a reaction vessel with stirrer, condenser and vacuum pump and the mixture is stirred at normal stirring speeds and heated to a temperature range of 80-90‘C under a vacuum at a pressure of 200-400 mmH G, so that the dimer acid is esterified by reacting with polyethylene glycol and oleic acid in the presence of organic-based acid catalyst.

[0034] Step 3: Monitoring the progress of the reaction, where the progress is monitored by the theoretical amount of water collected and the gradually decreasing acid number. When the acid number decreases to 10-14 mgKOH / g or when the theoretically calculated amount of water is collected, the reaction is cooled. Step 4: The synthesized oil emulsifier is then stored in a closed, light-proof container.

[0035] An emulsion test was applied to the prepared oil emulsifier to measure its performance. For this test, 20% oil emulsifier and 80% oil were mixed until homogenous and clear. Then, 5 grams of this mixture was taken and added into 95 grams of water and the emulsion quality was analyzed.

[0036] According to the quality examination applied (w.r.t. the state of the art), a positive result was obtained for the inventive product.

Claims

CLAIMS1 . A dimer acid-based fat emulsifier for use in oil dispersion (OD) formulations, characterized by comprising; dimer acid, polyethylene glycol, organic acid catalyst and unsaturated fatty acid.

2. The emulsifier according to claim 1 , characterized in that; the said unsaturated fatty acid is oleic acid and said organic acid catalyst is p-toluene sulphonic acid.

3. The emulsifier according to claim 2, characterized by comprising; Dimer Acid in the range of 15-50%, Polyethylene glycol in the range of 20-55%, oleic acid in the range of 25-50% and P-toluene sulphonic in the range of 0.1 -2% by weight.

4. The emulsifier according to claim 1 , characterized in that; the dimer acid is synthesized in unsaturated fatty acids.

5. The emulsifier, according to claim 1 , characterized by comprising; hydrogenated and saturated dimer acid.

6. The emulsifier, according to claim 1 , characterized in that; the polyethylene glycol is in liquid or solid form7. A method of obtaining a dimer acid-based fat emulsifier for use in oil dispersion (OD) formulations, characterized by comprising; the dimer acid is esterified by reaction with polyethylene glycol and oleic acid under organic based acid catalysis.

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