JPS59177122A - Dispersant - Google Patents

Abstract

PURPOSE:To provide a dispersant having excellent oil dispersibility to a non- polar or polar powder, obtained by containing high purity sorbitol fatty acid monoester which is an esterified product of sorbitol and higher fatty acid. CONSTITUTION:An oil dispersant comprises an esterified product of sorbitol and 12C or more higher fatty acid containing 50% or more of sorbitol fatty acid ester of which the sorbitor fatty acid monoester content is 60wt% or more and shows excellent oil dispersibility to a polar powder such as red oxide or titanium similarily to a non-polar powder such as carbon. As the above-mentioned higher fatty acid, straight chain or branched chain saturated or unsaturated fatty acids, such as, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, isopalmitic acid or isostearic acid are used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil-based dispersant containing highly purified sorbitol monofatty acid ester and having excellent dispersibility.

Conventionally, sorbitan monofatty acid esters have been widely used as dispersants in oil, either alone or in combination with other dispersants. Applications of darkening dispersants include, for example, inks and paints in which carbon and titanium are dispersed in mineral oil, and lipsticks in which red iron and titanium are dispersed in animal and vegetable oils. There is also active research into dispersing coal powder into oil and co-firing it.

However, unlike dispersion in aqueous systems, dispersion in fats and oils currently lacks a good dispersant, and for example, the concentration used is 10 to 100 times that of aqueous systems, making it extremely inefficient. Furthermore, since there is no good dispersant, the dispersoid must be made into fine particles, the types of dispersion medium are limited, and the viscosity of the dispersion medium must be increased.

Conventionally used sorbitan monofatty acid esters or sorbitol monofatty acid esters are synthesized by directly esterifying higher fatty acids with sorbitan or sorbitol in the presence of a catalyst. Therefore, sorbitol undergoes intramolecular condensation and changes to sorbitan and isosorbite, resulting in fatty acid monoesters and diesters of sorbitol, sorbitan, and insorbite.

Triesters are mixed. An example of the proportions of these components present in the product is shown in Table 1, where sorbitan fatty acid ester is the most abundant, and sorbitol fatty acid ester is small at around 10 percent.

Sorbitan fatty acid monoesters have been commercially available from many manufacturers since around the 1930s, but there are no major differences in their compositions.

Table 1 Composition of commercially available nurbitan monolaurate ester (gas chromatography analysis) Composition Weight composition ratio (1) The present inventors have determined that high-purity synthetic products (purity A detailed study of the dispersibility in oil (more than 90%) revealed that insorbite monofatty acid ester has almost no dispersion ability, and sorbitan monofatty acid ester has some dispersion ability, but it is not sufficient. Monofatty acid esters were found to have unexpectedly excellent dispersibility in oil.

Commercially available sorbitan monooleate is widely used as a dispersant in oil, but since it is nonionic, it is effective in dispersing nonpolar powders such as carbon, but it is effective in dispersing nonpolar powders such as red iron and titanium. The body has no effect. However, the sorbitol monooleate of the present invention
It not only has excellent dispersibility for carbon, but also for polar powders such as red iron oxide and titanium. This was completely unknown until now and could not have been predicted using conventional common sense.

The present inventors have completed the present invention by discovering that sorbitol monofatty acid ester having a specific composition range has extremely excellent dispersibility in oil.

That is, the present invention uses sorbitol fatty acid ester having a monofatty acid ester content of 60% by weight or more.
Contains 0 weight factor or more. This invention relates to an in-oil dispersant characterized by being composed of an esterification product of sorbitol and a higher fatty acid having 12 or more carbon atoms, and such a dispersant is commercially available as a conventional sorbitan fatty acid ester or a sorbitol fatty acid ester. It was found that the dispersibility in oil was several times that of the one with the same composition.

The sorbitol monofatty acid ester of the present invention cannot be produced by a commonly used high-temperature esterification reaction under an alkali catalyst, but can be produced, for example, by the method shown in the synthesis example.

The higher fatty acids having 12 or more carbon atoms in the present invention are linear or branched saturated fatty acids and unsaturated fatty acids, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, isopalmitic acid, and isostearic acid.
'Hereinafter, the present invention will be explained in more detail with reference to synthesis examples and examples, but the present invention is not limited thereto.

Synthesis Example 1 (Synthesis of sorbitol monooleate) Sorbitol (0.3 mol) is dissolved in DMF1[[d, and pyridine (0.12 mol) is added. Oleic acid triglyceride (0.1 mol) was added dropwise to it at 30-90°C,
React at that temperature for 4-5 hours. After the reaction, the solvent is distilled off, n-butanol is added, and the mixture is washed with water. n-Butanol is distilled off to obtain a crude product.

The crude product is recrystallized from methanol to give sorbitol monooleate. The yield I of the obtained sorbitol monooleate is 24.9 t (yield 58 qb). ()
Purity by LO is 98%.

Synthesis Example 2 (Synthesis of Sorbitol Monooleate) Sorbitol (0.3 mol) and oleic acid (CO, S mol) are reacted at 230°C for 4 to 5 hours in the presence of NaOH (0.2f). After the reaction, it was neutralized to obtain a crude product (120 t
). The crude product was separated by column chromatography (silica gel-chloroform:acetone=7:3) to obtain sorbitol monooleate. The purity of the obtained crude product according to GOI- was 99.

Synthesis Example 5 Sorbitol (1 mol) and oleic acid chloride (0,
7 mol) at 110°C. During the reaction, hydrochloric acid gas generated in a reduced pressure system is released from the reaction system.

The reaction product is washed with water to remove unreacted sorbitol. The reaction product contained 80 ft. of sorbitol monooleate.

Examples 1-4. Comparative Examples 1 to 5 0.2 portions of a dispersant having the composition shown in Table 2 were dissolved in mineral oil, and 1% of each of powders with different polarities (carbon, titanium, red iron) were dispersed, and the dispersibility was evaluated. The results are shown in Table 2. The dispersants of Examples 1 to 4 showed very good dispersibility.

Example 5 Dispersion of coal powder in heavy oil 1% of the sorbitol monooleate of the present invention was added to a 1/1 system of heavy oil/coal powder and thoroughly kneaded. The obtained system Fi exhibited excellent fluidity and dispersion stability. This sample was useful as a fuel.

Example 6 Lipstick Ceresin 10.0w
t% ester gum 9.0
Carnauba wax 5.0 Cetyl isooctanoate (N-KKOLC-0) 20.
0α-olefin oligomer (Nko KKOL 5yncelane30)
10.0 polybutene
5.0 Sorbitol monooleate
5.0 pigment suitable
The lipstick obtained with a fragrance preservative of castor oil of 100.0 had excellent gloss and very good pigment dispersibility.

Claims (1)

[Claims] A dispersant in oil characterized by comprising a sorbitol fatty acid ester having a sorbitol monofatty acid ester content of 60% or more.