GB2418202A

GB2418202A - Monoglycerides from glycerol

Info

Publication number: GB2418202A
Application number: GB0420627A
Authority: GB
Inventors: Hiroki Sawada; Jirou Hashimoto; Haruya Minou; Toshitsugu Maeda
Original assignee: Infineum International Ltd
Current assignee: Infineum International Ltd
Priority date: 2004-09-17
Filing date: 2004-09-17
Publication date: 2006-03-22
Also published as: GB0420627D0; JP2006083390A

Abstract

The invention provides a monoglyceride produced by reacting glycerin with at least one acyl-containing compound selected from fatty acids and glycerin esters. The reaction takes place in the presence of a catalyst containing at least one metal selected from iron, cobalt and manganese in an amount of 0.1 to 60 ppm in terms of metal (weight ratio to the total weight of glycerin and the acyl-containing compound). Alternatively the reaction comprises the step of maintaining the amount of water at 500 to 5000 ppm in the reaction system after the degree of conversion in the reaction of glycerin with fatty acid reaches 90% or more based on the fatty acid, or during the ester exchange reaction of glycerin with glycerin ester.

Description

24 1 8202

MONOGLYCERIDE-CONTAINING COMPOSITIONS

The present invention relates to monoglyceride-containing compositions having a high monoglyceride content.

Monoglycerides used widely as surfactants and the like in cosmetics, foods, and industrial emulsifiers or lubricants are produced by esterification reaction of glycerin with fatty acid or by ester exchange reaction of glycerin with fats or oils.

These reactions are carried out in the absence or presence of a catalyst, and generally a mixture of glycerin, monoglyceride, diglyceride and triglyceride is formed. The reaction system is usually a heterogeneous system, and the amount of monoglycerides formed is influenced by the solubility of glycerin in the fatty acid phase or a formed ester phase Thus even if the amount of glycerin used is increased, the content of monoglyceride cannot be increased. Accordingly, when higher performance (that is, high-purity) monoglycerides are to be obtained, purification by molecular distillation '. . is carried out. . ' . US-A 2474740 and US-A 2478354 disclose a method of accelerating the ester ë exchange reaction of 5 to 15% water-containing glycerin with fat and oil in the . .

absence of a catalyst. A problem with this method is that a pressurized system for.....

maintaining the amount of water required, and also that the unreacted fatty acid;- . remains in a considerable amount.

US-A 2206167 discloses a process for producing monoglycerides from glycerin and fats and oils by ester exchange reaction using an alkali (e. g. Na) soap as a catalyst. A disadvantage with this process is that when the unreacted glycerin is removed by distillation after the reaction, the alkali should previously be neutralized at high temperatures in order to prevent the content of monoglyceride from being decreased due to reverse reaction, and also that a neutral salt which cannot be separated even by filtration remains in the product.

US-A 2628967 discloses a process for producing monoglycerides by reacting glycerin or ethylene glycol with fatty acid or glycerin polyester at high temperatures 2004M013 GB in the presence of a specific transition metal (e.g. iron) catalyst. A disadvantage is that although neutralization of the catalyst is not necessary, the amount of the catalyst used is 80 to 1700 ppm in terms of metal, thus making the product hardly usable as it is owing to a large amount of insolubles. Also, because reverse reaction upon removal of glycerin by distillation promotes reduction in the content of monoglyceride, the catalyst should previously be removed by filtration or Recantation after cooling.

Further, there is a problem that in the filtration, the rate of filtration is lowered due to the remaining glycerin, whereas the Recantation results in lower yield. There is also a feature undesirable from the viewpoint of the process that heating should be conducted again to remove the unreacted glycerin by distillation.

In a first aspect, the present invention provides a monoglyceridecontaining composition obtainable by a process comprising the step of reacting glycerin with at least one acyl-containing compound selected from the group consisting of a fatty acid l5 and a glycerin ester; using a catalyst comprising at least one metal selected from the group consisting of iron, cobalt and manganese in an amount of 0.1 to 60 ppm in terms of metal as a weight ratio thereof to the total weight of the glycerin and the ..

acyl-containing compound. ..

In a second aspect, the present invention provides a monoglyceridecontaining.. ..

composition obtainable by a process comprising the step of reacting glycerin with at.. .

least one acyl-containing compound selected from the group consisting of a fatty acid and a glycerin ester, wherein the amount of water is maintained at 500 to 5000 ppm in the reaction system after the degree of conversion in the reaction of glycerin with fatty acid reaches 90% or more based on the fatty acid, or during the ester exchange reaction of glycerin with glycerin ester.

The present invention provides a monoglyceride-containing composition having a high content of monoglyceride from glycerin and fatty acid or glycerin ester, without using an expensive concentrator such as molecular distillation apparatus or a special high-speed stirring shearing machine.

2004M013 GB 3 The glycerin used in the present invention is not particularly important, but is preferably the one having a purity of 95 wt% or more.

The acyl-containing compound selected from fatty acid and glycerin ester, used in the present invention, is a compound having any of branched, linear, saturated and unsaturated acyl groups. Preferably, the number of carbon atoms in the acyl group is 12 to 30, more preferably 14 to 22.

Examples of the fatty acid used in the present invention include a single fatty acid such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid and linolenic acid, or fatty acid mixtures such as soybean oil fatty acid, rapeseed oil fatty acid and tall oil fatty acid. From the viewpoint of low temperature fluidity relating to handling of the monoglyceride-containing composition, the fatty acid is preferably one having an iodine value of 80 or more, more preferably 130 or more. Particularly preferred fatty acids include oleic acid, linoleic acid, linolenic acid, soybean oil fatty acid, rapeseed oil fatty acid and tall oil fatty acid. :

Preferably, the glycerin ester used in the present invention comprises triesters and diesters composed of the fatty acid and glycerin, as well as a mixture thereof .e The monoester may be contained in the glycerin ester. . From the viewpoint of obtaining a monoglyceride-containing composition having a high content of monoglyceride and improving productivity per batch, the reaction ratio of glycerin to the acylcontaining compound in the present invention is determined such that the amount of glycerin is preferably 1 mole or more, more preferably 1 to 3 moles, still more preferably 1.5 to 3 moles, per mole of the acyl group in the acyl-containing compound.

Preferably, the catalyst contains at least one metal selected from iron, cobalt and manganese, or a compound thereof. Suitable iron-containing catalysts include elemental iron, oxides and hydroxides such as Fe2O3, Fe2O4, FeOH, metal soaps such as iron acetate, iron propionate, iron stearate and iron oleate, and chlorides such as 2004M013 GB 4 iron (II) chloride and iron (III) chloride. Suitable cobalt- containing catalysts include elemental cobalt, CoO, CO3O4, cobalt carbonate, cobalt stearate, cobalt (II) chloride and the like. Suitable manganese-containing catalysts include elemental manganese, manganese dioxide, trimanganese tetroxide, manganese stearate and the like.

Preferably, the catalyst is an iron-containing catalyst, particularly preferably iron hydroxide. Preferably, the amount of the catalyst used is 0.1 to 60 ppm, more preferably 0.5 to 10 ppm, still more preferably 0.5 to 5 ppm in terms of metal.

From the viewpoint of increasing the monoglyceride content and reducing the amount of free fatty acid, the process used to produce the composition of the present invention comprises the step of regulating the water content of the reaction system in an amount of preferably 500 to 5000 ppm, more preferably 600 to 4000 ppm, still more preferably 600 to 3000 ppm, further more preferably 1000 to 3000 rpm, after the degree of conversion (defined in equation (I) below) in the reaction of glycerin with fatty acid reaches 90% or more based on the fatty acid, or during the ester exchange reaction of glycerin with glycerin ester. Although the role of water in the process of the present invention is not clearly understood, it is thought that the glycerin ester is partially hydrolyzed, releasing a small amount of fatty acid which in turn exerts catalytic action on the ester exchange reaction. ..

20....

The amount of water can be regulated by regulating the amount of an inert gas such as nitrogen introduced into the reaction vessel. Inert gas can be introduced into the reaction solution and/or to the space over the reaction solution, while the amount of water in the reaction solution can be measured with a water meter. The inert gas is supplied preferably continuously or intermittently. If the reaction becomes deficient in water, such as may happen in the reaction of glycerin with glycerin ester, the amount of water in the system can be regulated in the above range preferably by adding water. Addition of water may be combined with the introduction of an inert gas such as nitrogen into the reaction vessel.

I - [weight of unreacted fatty acid] Degree of conversion (%) = ------------- x 100 (I) [weight of charged fatty acid] 2004M013 GB 5 The temperature in the reaction of glycerin with the acyl- containing compound is preferably 180 C or more from the viewpoint of improving both the solubility of glycerin in an oil layer and the rates of esterification reaction and ester exchange reaction, and is preferably 270 C or less from the viewpoint of preventing formation of diglycerin as a byproduct. Specifically, the reaction temperature is preferably 180 to 270 C, more preferably 200 to 260 C, still more preferably 240 C to 255 C. When the reaction temperature is 250 C or more, the reaction time is preferably 12 hours or less, more preferably 7 hours or less, stir] more preferably 5 hours or less, although the reaction time may be varied depending on the reaction temperature because heating at high temperatures for a long time leads to an increase in the amount of byproduct diglycerin as a condensate of glycerin.

The monoglyceride-containing composition having a high content of monoglyceride can be used as it is, but glycerin, and the metalcontaining catalyst when used, are preferably removed. When glycerin and the metal-containing catalyst are removed, it is preferable from the viewpoint of productivity that the glycerin is distilled away in the presence of the metal-containing catalyst. If the metal ..

containing catalyst is filtered off before the glycerin is distilled away, the reaction mixture must first be cooled to 100 C or less to prevent arising from the heat . ...

resistance of the filtering material and the removability of the catalyst. The reaction mixture must then be heated again to high temperatures in order to distill glycerin away. This makes the process complicated The process used to produce the composition of the present invention is free of such complications. Further, in the process involving first distilling glycerin away and then filtering the metal-containing catalyst off, the highly viscous glycerin is not present at the time of filtration, and thus it is also advantageous in that the speed of filtration can be increased. Specifically, after the reaction, the glycerin is distilled away under reduced pressure, aided if necessary, by supplying water vapor under reduced pressure, and then the metal containing catalyst is removed by filtration.

The glycerin can be distilled away in a batch system or in a continuous system with for example, a thin film distillation apparatus. When the glycerin is distilled 2004M013 GB 6 away in the batch system, there are employed conditions under which the temperature is preferably 200 C or less, preferably 180 C or less, and the pressure is preferably 53 kPa or less, more preferably 2. 7 kPa or less. Filtration can be easily carried out with a zeta potential filter. s

The monoglyceride content of the composition of the present invention refers to a content determined according to the following equation (II) after GPC analysis (gel permeation chromatography), that is, the ratio by area of monoglyceride to the total of monoglyceride, diglyceride and triglyceride in GPC analysis.

Monoglyceride content (%) = MG/[MG + DG + TG]xlOO (II) Where; MG: Area of monoglyceride in GPC. .

DG: Area ofdiglycerideinGPC. . .

TG: Area of triglyceride in GPC. The monoglyceride-containing compositions of the present invention have..

high monoglyceride content of 55 % or more, for example 65% or 75% or more.

Examples...

The monoglyceride content was determined by GPC analysis. As the columns, TSK gel G2000HXL and TSK gel GlOOOHXL manufactured by Tosoh Corporation were connected in series, and RI (differential refractometer) was used as the detector, and THE (tetrahydrofuran) was used as the eluent.

The content of glycerin and diglycerin was quantified by GC analysis (gas chromatography), and the content of iron was quantified by ICP analysis (inductively coupled plasma-emission spectrometry).

Example 1

2004M013 GB 7 A 2-L four-necked flask equipped with a stirrer, a dehydration tube-cooling tube, a thermometer and a nitrogen inlet tube was charged with 480 g glycerin and 750 g tall oil fatty acid [glycerin/fatty acid (molar ratio) = 2.0], then iron hydroxide suspended in a small amount of water was added thereto in an amount of 2 ppm in terms of iron, and nitrogen was introduced at 100 mL/min. into a space over the solution, while the solution was heated over about 1.5 hours to 250 C under stirring at 400 r/min. After 250 C was reached, the mixture was reacted at that temperature for 4 hours. The acid value, water content and monoglyceride content were analyzed with time, and as a result, the water content was changed in the range of 700 to 1900 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the product after the reaction was 67%.

Subsequently, the reaction mixture was reflexed under reduced pressure, whereby the mixture was cooled to 170 C, then the glycerin was distilled away at a reduced pressure of 2.7 kPa or less, water vapor was supplied at 150 C at 2 kPa for 2 hours, and then the product was subjected to adsorption filtration with Zeta Plus 30S (manufactured by Cuno, Inc.) under pressure, to give a monoglyceride- containing composition. The monoglyceride content in the composition was 64%, the acid value .- was 0.2 mg KOH/g, the glycerin content was 0.3 wt-%, the diglycerin content was 0.3 .. . wt-%, and the iron content was 0.1 ppm or less. :- .

Example 2

The reaction was carried out in the same manner as in Example l except that iron stearate was used in place of iron hydroxide. The monoglyceride content in the product after the reaction was 65%, and the water content was changed in the range of 600 to 1300 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the composition after the adsorption filtration was 62%, the acid value was 0.2 mg KOH/g, the glycerin content was 0.4 wt-%, the diglycerin content was 0.4 wt-%, and the iron content was 0.1 ppm or less.

2004M013 GB 8

Example 3

The reaction was carried out in the same manner as in Example 1 except that nitrogen was blown at 100 mL/min. into the solution, and the reaction was carried out for 6 hours. The glycerin was removed and adsorption filtration was conducted in the same manner. The monoglyceride content in the product after the reaction was 63%, and the water content was changed in the range of 300 to 400 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the composition after the adsorption filtration was 61%, the acid value was 0. 3 mg KOH/g, the glycerin content was 0.4 wt-%, the diglycerin content was 0.5 wt-%, and the iron content was 0.1 ppm or less.

Example 4

The reaction was carried out in the same manner as in Example 1 except that iron (II) chloride.4H2O was used in place of iron hydroxide and added in an amount of 10 ppm in terms of iron, and the glycerin was removed and adsorption filtration was conducted in the same manner. The monoglyceride content in the product after the reaction was 66%, and the water content was changed in the range of 600 to 1500 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the composition after the adsorption filtration was 63%, the acid value was 0.2 mg KOH/g, the glycerin content was 0.5 wt-%, the diglycerin content was 0.3 wt-%, and the iron content was 0.1 ppm or less.

Example 5

The reaction was carried out in the same manner as in Example 1 except that soybean oil was used in place of tall oil fatty acid and charged in such an amount that the amount of glycerin was 2 moles per mole of acyl group in the soybean oil, and iron hydroxide was added in an amount of 10 ppm in terms of iron, and the reaction time was changed to 10 hours. The glycerin was removed and adsorption filtration was conducted in the same manner. The monoglyceride content in the product after the reaction was 64%, and the water content was changed in the range of 600 to 1400 2004M013 GB 9 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the composition after the adsorption filtration was 61%, the acid value was 0.4 mg KOH/g, the glycerin content was 0.4 wt-%, the diglycerin content was 0.9 wt-%, and the iron content was 0.1 ppm or less.

Example 6

A 2-L four-necked flask equipped with a stirrer, a dehydration tubecooling tube, a thermometer and a nitrogen inlet tube was charged with 480 g glycerin and 750 g tall oil fatty acid [glycerin/fatty acid (molar ratio) = 2.0], and nitrogen was introduced at 100 mL/min. into a space over the solution in the flask, while the solution was heated over about 1.5 hours to 250 C under stirring at 400 rpm. After 250 C was reached, the mixture was reacted at that temperature for 6 hours. The acid value, water content and monoglyceride content were analyzed with time, and as a result, the degree of conversion based on the fatty acid upon reaching 250 C was 93%, the water content at a degree of conversion of 90% or more based on the fatty acid was 700 to 2200 ppm, the degree of conversion upon conclusion of the reaction...

was 99%, and the monoglyceride content was 61%. . . .

Example 7. . :.

The reaction was carried out in the same manner as in Example 6 except that nitrogen was blown at 30 mL/min. into the solution, and the reaction was carried out at 250 C for 6 hours. The degree of conversion based on the fatty acid upon reaching 250 C was 93%, the water content at a degree of conversion of 90% or more based on the fatty acid was 600 to 900 ppm, the degree of conversion upon conclusion of the reaction was 99%, and the monoglyceride content was 60%.

Comparative Example I The reaction was carried out in the same manner as in Example 3 except that iron hydroxide was not added, and the glycerin was removed and adsorption filtration 2004M013 GB 10 was conducted in the same manner. The monoglyceride content in the product after the reaction was 54%, and the water content was changed in the range of 300 to 400 ppm when the degree of conversion based on the fatty acid was 90% or more. The monoglyceride content in the composition after the adsorption filtration was 51%, the acid value was 0. 3 mg KOH/g, the glycerin content was 0.4 wt-% and the diglycerin content was 0.7 wt-%.

Comparative Example 2 The reaction was carried out in the same manner as in Example 3 except that sodium hydroxide was used in place of iron hydroxide and added in an amount of 10 ppm in terms of sodium, and the glycerin was removed by distillation under reduced pressure without neutralization. The monoglyceride content in the composition after glycerin distillation was 48%, the glycerin content was 3.1 wt-% and the diglycerin content was 0.7 wt-%. . ' Comparative Example 3...

The reaction was carried out in the same manner as in Example 6 except that nitrogen was blown at 100 mL/min. into the solution, and the reaction was carried out at 250 C for 6 hours. The degree of conversion based on the fatty acid upon reaching . . . 250 C was 94%, the water content at a degree of conversion of 90% or more based on. . :.

the fatty acid was 300 to 400 ppm, the degree of conversion upon conclusion of the reaction was 99%, and the monoglyceride content was 54 area-%.

Claims

2004M013 GB 11 Claims: 1. A monoglyceride-containing composition

obtainable by a process comprising the step of reacting glycerin with at least one acyl- containing compound selected from the group consisting of a fatty acid and a glycerin ester; using a catalyst comprising at least one metal selected from the group consisting of iron, cobalt and manganese in an amount of 0.1 to 60 ppm in terms of metal as a weight ratio thereof to the total weight of the glycerin and the acyl-containing compound.
2. A composition according to claim 1, wherein at least one mole of glycerin is used and is reacted per mole of the acyl group in the acylcontaining compound.
3. A composition according to claim 1 or 2, wherein glycerin is reacted with the acyl-containing compound and then the glycerin is distilled away in the presence of the catalyst. '
4. A composition according to any one of claims 1 to 3, wherein the metal is...

iron. .
5. A composition according to any one of claims 1 to 4, wherein the process ' comprises maintaining the amount of water in the reaction system at 500 to 5000 ppm, . after the degree of conversion in the reaction of glycerin with fatty acid reaches 90% or more based on the fatty acid; or during the ester exchange reaction of glycerin with glycerin ester.
6. A composition according to any one of claims 1 to 5, wherein the number of carbon atoms in the acyl group in the acyl-containing compound is 12 to 30.
7. A composition according to any one of claims 1 to 6, wherein the reaction temperature is 180 to 270 C.

2004M013 GB 12
8. A composition according to any one of claims 1 to 7, wherein the monoglyceride content in the monoglyceride-containing composition as determined by GPC analysis is 55% or more.
9. A monoglyceride-containing composition obtainable by a process comprising the step of reacting glycerin with at least one acylcontaining compound selected from the group consisting of a fatty acid and a glycerin ester, wherein the amount of water is maintained at 500 to 5000 ppm in the reaction system after the degree of conversion in the reaction of glycerin with fatty acid reaches 90% or more based on the fatty acid, or during the ester exchange reaction of glycerin with glycerin ester.
10. A composition according to claim 9, wherein at least one mole of glycerin is used and is reacted per mole of acyl group in the acylcontaining compound.
11. A composition according to claim 9 or 10, wherein the number of carbon '.

atoms in the acyl group in the acyl-containing compound is
12 to 30. . 12. A composition according to any one of 9 to 11, wherein the reaction,,. .

temperature is 180 to 270 C. ' '
13. A composition according to any one of claims 9 to 12, wherein the. .:.

monoglyceride content in the monoglyceride-containing composition as determined by GPC analysis is 55% or more.