JPH02164886A - Production of powdery high-hlb sucrose fatty acid ester - Google Patents

Abstract

PURPOSE:To obtain the title compound industrially and advantageously without using an organic solvent by adjusting a synthetic reaction mixture of sucrose fatty acid ester containing unreacted substances by water medium method to neutral pH, adding water and a neutral salt to the mixture, washing formed precipitate with acidic water, ultrafiltering washed solution and spray-drying. CONSTITUTION:A synthetic reaction mixture of sucrose fatty acid ester containing the aimed substance of sucrose fatty acid ester, unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap and fatty acid by water medium method is adjusted to a neutral range, preferably pH6.2-8.2 and heated to preferably 50-80 deg.C. Then the mixture is blended with water and a neutral salt (preferably salt, Glauber's salt, potassium lactate or potassium acetate) and formed precipitate is washed with acidic water (preferably pH 3.0-5.5 at 10-40 deg.C). The washed solution is ultrafiltered and spray-dried to give the aimed ester.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an industrial method for producing powdered high HLB sucrose fatty acid esters. More specifically, the present invention provides powdery high-H
This invention relates to a method for industrially producing LB sucrose fatty acid ester. [Prior Art] (Background) Currently, sucrose fatty acid esters (
(hereinafter abbreviated as <<SE>)) is produced by industrially reacting sucrose with 08-C22 higher fatty acid methyl ester in a solvent (dimethylformamide, dimethyl sulfoxide, etc.) under an appropriate catalyst (solvent method). :Special public school 1977-1
3102) or by making sucrose into a molten mixture with fatty acid soap using water without using a solvent, and then reacting it with higher fatty acid methyl ester in the presence of a catalyst (water medium method: Japanese Patent Publication No. 14485/1985). It has been obtained. However, in both of these two synthesis methods, the reaction mixture contains, in addition to the target SH, unreacted sugars, unreacted fatty acid methyl esters, residual catalysts, soaps, free fatty acids, etc. Among these impurities, impurities that exceed a specified amount must be removed before becoming a product. In particular, the former solvent method requires complicated steps to remove high-temperature polar solvents such as DMF, whose regulations have become particularly strict in recent years. On the other hand, according to the latter aqueous method, there is no fear that the reaction solvent will be mixed into the reaction mixture, but since it contains a large amount of impurities, a large amount of organic solvent (hereinafter referred to as However, the use of solvents for purification brings about many industrial disadvantages as described below. ■ Risk of explosion or fire. ■ Explosion-proofing of electrical equipment in preparation for ■ above. ■ Seal the manufacturing equipment in preparation for the above ■. ■ The entire building will be made into a fire-resistant structure in preparation for ■ above. ■ Increase in fixed costs due to ■, ■, and ■ above. ■ Increased cost due to solvent wastage. ■ Negative effects due to residual solvent remaining in product SH. ■ Negative impact on employees' health, which in turn increases the number of shifts and costs due to increased number of shifts to prevent this. The disadvantages resulting from the use of these solvents pose a particularly significant hindrance, especially when industrial production of SH is intended. Therefore, S
The development of a purification technique that eliminates the need for the use of purification solvents during E purification is a pressing need in the industry. (Problems with the Prior Art) Therefore, purification methods that do not use organic solvents have been studied. For example, (1) precipitation method of SH using an acidic aqueous solution (British Patent No. 809,815 (1959)
)) (2) A method of precipitation of SE using a general neutral salt aqueous solution (Japanese Patent Publication No. 42-8850) is known. In addition to the above purification, since water is used as a purification solvent, the necessary SE is obtained as a hydrated product, so in order to make water-based purification industrially possible, it is necessary to further
drying methods shall be considered. That is, the water-containing SE to be dried here is normally in the form of an aqueous solution if the water content is 80% or more, and in the form of a slurry if the water content is less than 80%. The viscosity of these SH hydrates generally increases rapidly from around 40'O and reaches the highest value around 50°C, but when the temperature exceeds 50°C, the viscosity decreases rapidly, which is a very unique viscosity behavior. (Published by the applicant company (Sugar Ester Story) +08 pages). Therefore, attempts to simply evaporate water by heating under vacuum are virtually impossible due to the significant foaming properties. Especially in the final stage of water evaporation, SE itself has a low softening point or melting point (for example, the softening point of sucrose monostearate is around 52°C, and the melting point of sucrose distearate is around 110°C). It has a tendency to retain any remaining water, which makes dehydration more difficult. If the temperature during heating is high and the contact time with the heat transfer body is long, SE itself will decompose, causing not only strong coloring and caramelization, but also decomposition,
The acid value also rises due to the free fatty acids (Special Publications Publication No. 37)
-9988). In addition, the latent heat of vaporization of water is unusually high compared to the solvent (
500 kcal/kg-820 or more) and the high evaporation temperature are also factors that make drying difficult. Therefore, even when using a so-called flash dryer, which heats the slurry and continuously supplies it to a vacuum chamber and discharges it, as another type of drying method, for example, the large latent heat of water makes it difficult to dry the slurry sufficiently. There are various difficulties in dehydration and drying, and even if these difficulties can be overcome, SE is in a molten state after being dehydrated and dried under vacuum, so the melting point cannot be determined after taking it out of the dryer. It requires many steps, including cooling by blowing cold air, solidifying, and finally pulverizing in a pulverizer, and the final pulverizing step is accompanied by concerns about dust explosions. Therefore, solving the various problems associated with drying as described above is an important step for realizing the present aqueous method production. (Margin below)

[Problem to be solved by the invention]

Therefore, the problem to be solved by the present invention is to solve the problem without using any solvent in the reaction process or the purification process.
The aim is to solve all the problems caused by the use of reaction solvents and purification solvents by developing a technology to obtain industrially produced powdered high HLB-3E. (Concept of the Invention) Therefore, the present inventor aimed to (a) minimize the amount of SE dissolved in the aqueous phase, (llI) avoid decomposition of unreacted sugar, and (c) purify the precipitated SE. As a result of many salting-out experiments aimed at solving the three problems of powdering in a state of Under the combination of the concentration of the reactive salt and the amount of water, a favorable phenomenon occurs in which not only a large proportion of SE precipitates, but also salts derived from the catalyst are dissolved in the aqueous phase in addition to the unreacted axes. I found it. Then, after dissolving the precipitated SE in water again, the reprecipitation operation with an aqueous solution of a neutral salt is repeated, and after removing the remaining unreacted sugar contained in the SH, this It was found that by adding acidic water with an appropriate pH to the precipitate and stirring, the high HLB content in the precipitate was transferred to the acidic aqueous phase, and the low HLB content remained in the remaining precipitate. . Incidentally, it was impossible to recover the high HLB-3E that had migrated into the aqueous phase using conventional technology, but as a result of research, the inventor found that such recovery could be done in the form of an aqueous solution by using an ultrafiltration membrane. It was discovered that by spray-drying this aqueous solution, it could be turned into powder without degrading quality. Thus, without using any organic solvent from the SE reaction mixture. (1) to remove impurities, (2) to obtain powdered SE of high
It has become industrially possible to separate E to suit its purpose. (Summary) The present invention is based on the above-mentioned discovery, and a reaction mixture containing the target sucrose fatty acid ester, unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap, and fatty acid in a neutral region. The production of a powdered high HLB sucrose fatty acid ester is characterized by adjusting the pH to a pH of The method is summarized. (Skeleton of the Invention) Therefore, the present invention consists of the following steps. (1) Removal of impurities from the crude SE reaction mixture (
salting out process). (II) Step of washing impure SE precipitate (fractionation step). (m) High HLB-3H recovery step (ultrafiltration step). (IV) Dehydration process (spray drying process) of recovered high HLB-3E. Below, we will discuss various matters related to the invention. (Aqueous medium method SE synthesis reaction mixture) The method for producing SE by water medium method synthesis is a method in which sucrose is made into a molten mixture with fatty acid soap in the presence of water, and then reacted with higher fatty acid methyl ester in the presence of a catalyst. (Japanese Patent Publication No. 51-14485, etc.), and its feature is that the reaction mixture contains more soap than the mixture synthesized by the solvent method, but has the advantage that it does not contain any residual reaction solvent. It is. The SE reaction mixture synthesized by the aqueous method generally has a composition in the following range. Sucrose fatty acid ester = 15-74% unreacted sugar
-1.0-80% unreacted fatty acid methyl ester = 0.5-10% neutral 4 derived from potassium carbonate
=0.05-7% soap =10
~50% fatty acids; 0.5-10%
At this time, the ester distribution of SE is monoester 10~
75% (diester or higher is 80-25%). The fatty acid roots mainly contained in each of fatty acid methyl esters, soaps, and fatty acids are saturated and have a common CI
It has a carbon number of 6 to C22. (Addition of water) Next, water was added to the above reaction mixture, water: reaction mixture -5 = 1 to 40:1 (weight ratio)... (1
), more preferably, water:reaction mixture = 20:I (weight ratio)...in the ratio of formula (2), and the pH is preferably 6.2 to 82. is I) H7,5. In this case, the water addition ratio is outside the above range, e.g.
If the ratio of water to reaction mixture is less than 5, the resulting aqueous solution will have a high viscosity, making subsequent operations substantially difficult. Conversely, the quantitative ratio of water and reaction mixture is 40.
If too much water is added, the viscosity will be reduced and subsequent operations will be easier, but on the other hand, a large amount of energy will be required to remove the water when recovering unreacted sugar, etc. As a result, economic efficiency will be lost. Furthermore, the pl of the aqueous solution is preferably adjusted between p) 18.2 and 8.2 in order to avoid decomposition of the target SE. Under hydrogen ion concentrations of pH 8.2 or higher, there is a risk of quantitative SE decomposition due to alkali.
If exposed to high temperatures above 0°C, there is a risk of acid decomposition. (Salting out) The aqueous solution of the SE reaction mixture, pH adjusted as above,
Maintain the temperature at 50-80°C as much as possible and add neutral salt. The present inventors discovered that when an aqueous solution containing precipitated SE obtained by adding a neutral salt was heated to 50 to 80°C, the added neutral salt was converted into lactate, acetate, common salt, or mirabilite. In any case, by setting the concentration of neutral salt at 6%,
We have discovered a phenomenon in which a large proportion of SE precipitates. This phenomenon is a unique phenomenon and has important value for the purposes of the invention. By cleverly utilizing this fact, ■ Unreacted sugar ■ Salt derived from the catalyst ■ Added neutral salt migrates to the aqueous phase, and the precipitated SE cake (i.e.,
This makes it possible to separate it from the slurry (sludge-like slurry). Table 1 shows this phenomenon in more detail. In the same table, weight of SE dissolved in the aqueous phase = Y [g] Weight of precipitated SE - X [g] Total SE (X+Y) [g] dissolved in the aqueous phase If the weight ratio of SE that is -φ [%] is given, φ is defined by the following formula (3). Here, the following conditions: Temperature = 75°C, pH = 7.8, Water: 5E = 20.1 (weight ratio) Fatty acid residue - Composition of stearic acid SE Sucrose fatty acid ester Unreacted fatty acid methyl ester - 2% Soap = 2% = 84% Fatty acid -1% Others = 1% cy) Ester distribution in SE: Monosful = 73% Diester or more = 27% Table 1 Removal of sucrose, neutral salts, etc. can. (Left below) *Total salt = 10 salts derived from the catalyst 10 added neutral salts By determining the amount of dissolved neutral salts in this way, it is possible to approach φ = O (i.e., a large proportion of SE The precipitated SE is collected by filtration or centrifuged and dissolved in the aqueous phase (washing).In the salting out step, a large proportion of the reaction mixture is removed from the aqueous solution by adding a neutral salt. The precipitated SE is in a water-containing state, that is, in the form of a slurry. This product contains impurities such as salts and sucrose, although in relatively small amounts. As a result of intensive research into a method for purifying this impure slurry, the inventor found that good results could be obtained by washing it with acidic water. That is, the above impure SE slurry was mixed with p) l=3. (1~5
．． Impurities are eluted by washing with acidic water adjusted to pH 5. Acids used here include, for example, hydrochloric acid,
Mineral alcohols such as sulfuric acid and organic acids such as vinegar and lactic acid are suitable, but as long as they are edible, they are not limited to those listed separately. Note that the temperature of the acidic water is suitably 10 to 40°C. By washing under such conditions, impurities desired to be removed from the cake side (sugar, added neutral salt, salt derived from the catalyst, etc.) can be transferred to the aqueous phase side. In the following cleaning operation, if the temperature of the acidic water exceeds 40°C, if the operation lasts for a long time, for example, several months, there is a concern that not only will the SE decompose, but also the viscosity will increase. operation becomes difficult. On the other hand, maintaining the temperature at a low temperature of 10° C. or lower requires a refrigerator that is not economical. Therefore, it is generally preferable to operate at a temperature of 10 to 40°C, especially around room temperature. In addition, when washing the SE cake with this acidic water,
SE consists of the unreacted side contained in this cake, the added neutral salt, and the salt by-produced by neutralization of the catalyst.
It is desirable that the SE cake be shredded in the acidic water to the smallest possible particle size in order to liberate the particles of impurities that it contains, as they need to be removed from the cake. This purpose can be efficiently achieved, for example, by a subdividing device such as a mixer (for example, manufactured by Tokushu Kiki Kogyo ■ (Homomixer)), a homogenizer, or a colloid mill (for example, under the trade name (Mycoreuter)), and the unreacted On the other hand, the salts derived from the catalyst and the neutral salts migrate from the cake with the total ratio WjsE to the quasi-wood phase by 2°. At this time, a remarkable phenomenon occurs in which high HLB-3E from the precipitate begins to dissolve into the acidic water side. This high HLB
The dissolution tendency of -5H in water varies depending on factors such as the temperature and pH of the system, but for example, when the pH is about 3.5 at room temperature, it is as shown in attached Figure 1. Here, since high HLB-3E has high water solubility, let us assume that it is named as (water-soluble SEA>) and Y'
Give °. Y has a high HLB and therefore exhibits high water solubility. For this reason, it does not precipitate even in acidic aqueous solutions and normally dissolves in the solutions. On the other hand, low HLB-3E has low water solubility, so
Generally, there is a tendency to precipitate at a certain level of acidity. Therefore, we tentatively named this (sedimentation SE>) and used the sign as °X''
give. X has a low HLB and therefore tends to precipitate from acidic aqueous solutions. The above ff11 diagram is a triangular coordinate system in which the sum of monoester, diester, and triester champions is expressed as 100%. In the figure, point M represents the composition of the original sample SE. The X point represents the composition of precipitable SE with low HLB SE. Point Y is a high HLB SE and represents the composition of water-soluble SE. The subscript 1.2.3 represents the different SEs of the ester distribution. For example, in the same figure, the ester distribution M2 (monoester - 73%, diester - 22%), diester =
If an aqueous solution with a pH of 3.5 is added to an SE sample with an SE concentration of 3% (5%), the SE becomes (X2
) with the ester distribution (monoester = 68%, diester -25%, triester = 7%) and (Y2) with the ester distribution (monoester = 84%,
Diesters - 13%, triesters = 3%). The weight of X2 and Y2 to be divided, that is, Wx2 and WY2
From the properties of triangular coordinates, WN2 = WX2 + WY2−===(a) WY2・
Notification - WN2/Revised... (b) (However, Y2
M2 is the distance between point M2 and point Y2, X2 M2 is ×2
The distance between point and M2 point, WN2 is M2(7) weight, WN2
is the weight of x2, WY2 is the weight of Y2, where the weight is the value as a dry product). Thus, SEs with a relatively high monoester content (i.e., SEs with high HLB) are more soluble in acidic water,
By cleverly utilizing the property that relatively low monoester SEs (i.e., low HLB SEs) tend to exist on the precipitation side, we can quantitatively divide SEs into high-HLB and low-HLB SEs. Can be divided. Furthermore, the higher the monoester content in SE, the more SE dissolves in water.
If the amount of (Y) increases and vice versa, 5E dissolves in water.
A tendency for the amount of (Y) to decrease was also discovered. Thus, since the acidic aqueous solution obtained in this washing step contains a relatively large amount of high HLB-3E, it is separated by filtration or centrifugation from precipitated SE, which is mainly comprised of low HLB SE. The obtained filtrate (or supernatant) needs to be further purified because it contains smaller amounts of salt, sucrose, etc. in addition to high HLB SH. (Ultrafiltration) Therefore, the present inventors conducted intensive studies on means for removing small amounts of salt and sucrose contaminating the above-mentioned high HLB-SE-containing impure filtrate. As a result, the use of an ultrafiltration membrane was found. I found it useful for this purpose. It is known that SEs coalesce with each other under certain conditions in an aqueous solution to form an aggregate of high molecular weight micelle structures (see p. 102 of the above publication). By the way, regarding the types of SH, monoesters, diesters, and triesters are those in which 1 to 3 fatty acid residues are bonded to each of the oxygen atoms of the three primary hydroxyl groups of the sucrose molecule. It's called ester. As is well known, although monoesters have greater hydrophilicity than diesters and triesters, the degree of micelle formation in water is small, resulting in relatively low molecular weight (small molecular diameter) SE micelle aggregates. form. On the other hand, diesters and triesters have relatively low hydrophilicity but have extremely high micelle-forming ability, so they form SE micelle aggregates with extremely large molecular weights (ie, large molecular diameters) in water. Commercially available SEs are rarely produced as a single monoester, but are usually produced as a mixed composition with a monoester content of, for example, 70%, 50%, 30%, etc. The present inventors have found that, for example, SE with a high monoester content of 70% creates SE aggregates with lower molecular weight than SH with a low monoester content of 50%, so that the aggregate size increases accordingly. Small microscopic diameter and therefore monoester content of 50% for ultrafiltration membranes with constant pore size
Therefore, it is undesirable that it tends to pass through the membrane together with unreacted sugars and by-product salts from the catalyst (salts obtained by neutralizing the catalyst with acid). I learned that I have a tendency. Therefore, as a countermeasure to this problem, the present inventors have proposed that when it is desired to remove unreacted sugars, catalyst-derived salts, etc. from impure SE with a high monoester content,
It is better to select a filtration membrane (with small pore size), and
On the contrary, in the case of SE with a low monoester content, it has been found that it is convenient to select a filtration membrane with a high molecular weight cutoff (that is, a large pore size) in order to speed up the processing speed. In addition, the inventors believe that among the substances contained in the reaction mixture, unreacted fatty acid methyl ester, soap, and fatty acid exist in a state encapsulated in the micelle structure aggregate of SE. It has also been confirmed from many experimental results that it is virtually impossible to separate SE and these three substances by means of filtration. From many experiments, we can conclude that ultrafiltration membranes (with an appropriate molecular weight cutoff) using pressure as a driving source
The impurities that can pass through with water are mainly sucrose containing unreacted sugars, salts derived from catalysts, and neutral salts that have been added to the membrane. Substances that cannot pass through include SE, unreacted fatty acid methyl ester, soap, and free fatty acids. In this process, by cleverly utilizing these facts and selecting an ultrafiltration membrane with an appropriate molecular weight cutoff, unreacted sugars and catalyst-derived salts are separated by SE, unreacted fatty acid methyl ester, It attempts to separate and remove soap and fatty acids. (Molecular weight of the substance to be filtered) In order to select an ultrafiltration membrane with an appropriate molecular weight cutoff, it is necessary to know the approximate molecular weight of the substance to be filtered. The molecular weights of these single substances relevant to the invention are as follows. ○ Sucrose = 342 0 Fatty acid methyl ester of water reaction Stearic acid methyl ester - 280 0 When using hydrochloric acid generated by neutralization of catalyst (K2 C03) → Potassium lactate - 128 When using acetic acid → Potassium acetate = 88 0 When using neutral salt salt = 585 05E (as a monomer that does not form micelle aggregates) Sucrose monostearate 1. fioO Sucrose disodistearate = 858 Sucrose tristearate - 1116 0 Ishie stearin butyric acid - 298 Potassium stearate - 314 0 Fatty acid stearin butyric acid = 276 0 Water - 18 By the way, the appearance of the micellar structure aggregate of SE is the molecular weight (
(hereinafter referred to as the molecular weight of the SE micelle aggregate) is assumed as follows. Since SE in an actual aqueous solution forms a micelle aggregate in water, for example, if the number of SE micelles is 10, the molecular weight of the micelle aggregate is 100% of the monoester.
As %, ◇Molecular weight of monoester monomer (Boo)X 10=e
,oo. Assuming 100% diester, ◇Molecular weight of diester monomer (850) x 10 = 8,
Assuming 580 triester 100%, ◇Trinis 7Jl/(7) Molecular weight (1,116)XIO
=11,180 Since an actual SE is a mixture of monoester, diester, and triester, it is better to define the average molecular weight as the molecular weight of the SE micelle aggregate. (Molecular weight cutoff of ultrafiltration membrane) A membrane suitable for the purpose of the invention is selected as follows. First, with a filtration membrane with a molecular weight cutoff of 200, even if the reaction mixture in the aqueous solution state is supplied to the water membrane under pressure to remove salts generated from the unreacted side and the catalyst (K2 CO3),
The ultrafiltration membrane can separate water, catalyst (K2
CO3). Molecular weight cutoff 200
Since sucrose with a larger molecular weight of 342 does not pass through the ultrafiltration membrane at all, the unreacted side cannot be separated and removed by SE. Next, in the case of an ultrafiltration membrane with a molecular weight cutoff of 5,000,
Since the sucrose and the salt from the catalyst each have a molecular weight of less than 5.000, they can easily pass through the micropores of the ultrafiltration membrane. SE constitutes the above-mentioned micelle east coalescence, and if we assume that the number of micelles is 10, the molecular weight of the SE micelle aggregate is estimated to be e, ooo or more. It is assumed that when the molecular weight is greater than 5.000, the micelle aggregate cannot pass through the micropores, and this assumption was confirmed experimentally. Separately, the case of a filtration membrane with a molecular weight cutoff of 1,000 was also investigated, and the results were as expected. In this way, by appropriately selecting the molecular weight cutoff of the ultrafiltration membrane, it becomes possible to remove impurities including unreacted side from impure SE. (Conditions that the ultrafiltration membrane should have) The unreacted side contained in the SE reaction mixture and the catalyst (K2C
When attempting to separate the salts that are by-produced from 03) from the SE, unreacted fatty acid methyl esters, and fatty acids, the ultrafiltration membrane must have the following conditions: If it has a molecular weight, ■ it must have resistance to physical external force. ■ Must be heat resistant and not decomposed by microorganisms. ■ Appropriate molecular weight cutoff and large processing capacity. ■ Long service life. ■ Availability of economical pricing offers. etc. Since there has been remarkable progress in technology in the production of ultrafiltration membranes in recent years, there are commercially available membranes that meet the above conditions. (Ultrafiltration conditions) The aqueous solution containing the water-soluble (Y) obtained in the previous step is neutralized by adding an alkali prior to the main ultrafiltration, and the liquid property is adjusted to PN 6.
．． 2 to 8.2, preferably around pl (7.5).If the pH of the neutralizing solution exceeds 8.2, SE decomposition will proceed, and if the pH is less than 6.2, SE micelle aggregates will occur. This makes it difficult to form SE, which is undesirable as it causes SE to flow out of the ultrafiltration membrane or clog the pores.The temperature of the aqueous solution during filtration is preferably 80°C or lower, regardless of the type of fatty acid methyl ester. , there is a concern that SE will decompose if the temperature exceeds the same temperature.The inventors have found that the maximum filtration rate is obtained when the temperature is particularly within the temperature range of 40 to 60 °C. Filtration temperature 4
When the temperature is adjusted to 0 to 60°C, preferably about 50°C, unreacted sugars, salts from the catalyst (K2c:03), and added neutral salts pass through the filtration membrane most efficiently together with water, for reasons explained below. do. The reason for this is that at 40 to 60°C, the molecules of SE micelle aggregates become gigantic, resulting in a decrease in the total number of micelle aggregates, and substances that are not originally involved in the formation of micelle aggregates, such as unreacted sugars, are It is presumed that this is because it becomes difficult to resist the resistance of SH, making it easier for unreacted sugars, etc. to pass through. It is known that an SE aqueous solution generally exhibits its maximum viscosity between 40 and 60°C (cited above, p. 103);
This suggests that it can have the maximum molecular weight within that temperature range, and this fact also explains why unreacted sugars etc. exhibit the maximum passing rate in the range of 40 to 60°C. Thus, the reaction mixture aqueous solution containing SE maintained at 40-60°C was pumped at 1-20 Kg/cm2G.
Pressure is applied as a driving source to pH 8.2~
It is brought into contact with an ultrafiltration membrane in a hydrogen ion concentration range of 8.2. As a filtration membrane, a cellulose-based membrane is not only physically weak but also easily attacked by microorganisms, so it is not very desirable for practical purposes. Practically preferred are membranes made of polysulfonic acid or polyvinylidene fluoride reinforced with a support layer. Both of these types of filtration membranes are currently commercially available, and have excellent heat resistance, acidity, and alkali resistance, are resistant to external physical forces, and, moreover, microorganisms do not grow on the membrane surface. As mentioned above, when determining the molecular weight cutoff of a filtration membrane, S
Unreacted sugars, etc. are efficiently separated without leaking E.
It is important to select one that also has a high filtration rate. As a result of study, the inventors found that the molecular weight cutoff of the membrane was 1, which satisfies the desired conditions of no leakage of SH, no loss of separation of unreacted sugars and by-product salts, and high filtration rate. A filtration membrane with a molecular weight cut off of 5,000 is most preferable because it is preferably in the range of 000 to 100,000, and in particular, it does not leak SH and is suitable for processing on an industrial scale. I discovered that. Membranes with a molecular weight cutoff of more than 5,000 cause SE leakage, albeit slightly, while membranes with a molecular weight cutoff of less than 5,000 reduce the filtration rate. However, in either case, it does not bring about such a disadvantage that it is not industrially profitable. Among the currently commercially available filtration membranes, those suitable for the purpose of the invention include, for example, the ultrafiltration membrane sold by Toshi Engineering ■, product name <<TERP-E-5)) (polyvinylidene fluoride). ,((TERP-HF-10>>
(Polysulfone type) and <<TERP-) IF-100
>> (Polysulfone type) etc. Through the above ultrafiltration treatment, impurities such as sucrose and salts are removed from the pickling solution of the salting-out precipitate, resulting in high purity, high HLB.
-5E (Y) is usually recovered in the form of a 5-15% aqueous solution. The monoester content of this high HLB-3E (Y) is, for example, as shown in the example shown in the attached Figure 1, when the crude SE, which initially had a monoester content of 73%, was changed to a monoester content of 84% (cy) by pickling. -5E and low HLB-3E with a monoester content of 68%. Such high HLB-3E has conventionally been considered impossible to produce industrially. (Spray Drying) The above high HLB-3E aqueous solution can be concentrated to a concentration of about 25% by ordinary vacuum concentration.
In solution form, it is inconvenient to handle and distribute. However, based on the results of numerous experiments, the present inventor found that the use of spray drying means is optimal for dehydrating the above-mentioned high HLB-3E aqueous solution. Incidentally, as mentioned above, even when using a normal vacuum dryer such as a so-called groove-type agitating dryer, slurry is continuously supplied, heated, and released into a vacuum chamber. Even when using a so-called flash dryer, it is possible to avoid quality deterioration phenomena such as an increase in the acid value of the treated SE, coloring, and caramelization due to the viscosity characteristics and low melting point of SE. Furthermore, in the case of the back beach, the risk of dust explosion cannot be ignored. However, by employing the spray drying means discovered by the inventor, the drawbacks of the existing drying means can be solved at once. In the drying step of the present invention, the water-containing sucrose fatty acid ester in an aqueous solution state is continuously supplied to the spray drying tower via a pump, and is turned into fine atomized particles by spraying from a nozzle or centrifugal force from a rotating disk. Divide and contact with drying air stream. This significantly increases the evaporation area of water, and therefore dehydration and drying can be completed within an extremely short time (within a few seconds after spraying). Note that as the atomization means, it is desirable to use a rotating disk because the viscosity of the hydrous sucrose fatty acid Nistyl is high. (Spray drying conditions) The supply temperature of the aqueous solution of sucrose fatty acid ester is 40 to 80
Although the temperature can be changed arbitrarily between 40 and 60 degrees centigrade, it is preferable to select a temperature in the range of 40 to 60 degrees centigrade from the viewpoint of quality. When the above solution or aqueous solution is atomized by a rotating disk,
For example, when the diameter of the disk is 5 to 10 cmφ, 15,0
A rotation speed of 00 to 24.00 rpm is suitable. The air blown into the tower should have more than the amount of heat needed to evaporate the water in the solution or aqueous solution, so if the air temperature is low, a larger amount of air is required. The air temperature at this time may be in a wide range of 10 to 100°C, but it is advantageous to select a temperature between 60 and 80°C in consideration of drying efficiency and prevention of thermal decomposition of the target sucrose fatty acid ester. be. The humidity in the blown air is also related to the drying efficiency as well as the air temperature. It is economical for the absolute humidity suitable for work to be approximately within the range of . Conditions such as the required volume, required tower diameter, and required surface area of the spray drying tower are designed on the premise of the above spray conditions. If the tower design and operating conditions are suitable, powdered dry sucrose fatty acid ester with a moisture content of less than 5% is continuously discharged from the bottom of the spray drying tower. The resulting product has a short thermal history, so it is of excellent quality and requires almost no drying personnel.

[Effect]

After adding acid to the sucrose fatty acid ester production reaction mixture containing unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap, and fatty acid to be synthesized using the aqueous medium method and adjusting the pH to a neutral range, water, neutral When salt is added and salted out at an appropriate temperature, sucrose fatty acid ester, unreacted fatty acid methyl ester, soap, and fatty acid are precipitated, and a large proportion of SE can be recovered as a precipitated phase. Next, this precipitate is washed with acidic water, and the washing liquid is ultrafiltered to remove contaminating sucrose in the precipitate that has migrated into the washing liquid, added neutral salts, and by-products due to neutralization of the catalyst. A highly purified aqueous solution of HLB-3E from which impurities such as salts have been removed is obtained. Finally, by spray drying this aqueous solution, high quality HLB-3E is continuously produced as a powder with good flowability, thus high HLB-3E is produced without using any solvent.
Industrial production of powdered SE with B value becomes possible.

【Example】

Hereinafter, embodiments of the invention will be specifically explained using Examples, but each example is of course for illustrative purposes and has no direct relation to the technical scope of the invention. After neutralizing the aqueous method SE reaction mixture with the composition shown in Table 2 below with milk, add 2.000 kg of water to 100 kg of dried dry matter.
g was added and dissolved. LoOKg of salt was added to this aqueous solution, heated to 80℃, heated to temperature A, and the precipitated cake was separated by filtration, with a solid content of 45.0.
Got % cake. Table-2 Terminal ester distribution: 65% monoester, diester and above
235%. Add room temperature hydrochloric acid water (pH 3,8) 2000 to the above cake.
When Kg was added, SE was immediately precipitated as a white precipitate. Next, the acidic aqueous solution (pH 3.8) containing this precipitate was sufficiently stirred using a homomixer (described above), and then the precipitate was collected by filtration. This precipitate was washed twice by adding acetic acid water again, and after adjusting the pH to 7.5 with caustic soda, the precipitate contained 32% solids, and the dry matter was as follows:
It had a composition of 3. Table 3 On the other hand, the amount of filtrate produced when the precipitate was washed with acidic water amounted to about 6,000 kg in the second operation. The solid content contained in this 8,000 kg of filtrate is shown in the table below.
It was as follows. Table-4 This filtrate was adjusted to 1 (P = 1,000 kg) to 17.5,
Ultrafiltration membrane manufactured by Toshi Engineering ■ (TERP-E
-5>> (molecular weight cut off 5,000) was sent to a spiral type (4" x 1 m) cylindrical pressure filtration unit with a membrane area of 80 m' under the following conditions. Temperature = 49°C to 50°C 1 Discharge rate from the filtration membrane = 35-45 (kg / min), circulation rate of the filtration membrane = 200-220 (kg / min), after about 145 minutes, 170 kg of concentrated solution is added to 51120 kg of water
After adding Kg and stirring, the solution was sent to the ultrafiltration membrane again under the same conditions. As a result of repeating this operation four times, the composition of the concentrated liquid (in dry form) was as shown in Table 5 below. Table 5 The solid content concentration of this aqueous solution was 10.1%. This aqueous solution was heated and concentrated under vacuum to bring the solid concentration to 24.
% and then spray-dried under the following conditions. Spray drying tower diameter: 2.0 mφ Length of straight cylinder: 1.5 m Rotating disk (disc) diameter: 10 cmφ Disk rotation speed: 2
4,00 Orpm Inlet air temperature = 70°C Powdered SE obtained from the bottom of the spray drying tower has a moisture content of 1.
9%, bulk specific gravity 0.42, no coloration due to overheating, and good fluidity. Drying could be continued stably, and the composition of the obtained powder was as shown in Table 6 below. Table 6 *Monoester in SE - 79.0% Diester or more = 21.0% Thus, in the ester distribution in the initial reaction mixture, the monoester content was 650% (diester or more 35%).
) increased to monoester-containing i 78 and 0%, resulting in an SE showing a correspondingly higher HLB value.

【Effect of the invention】

As explained above, the present invention is directed to industrially producing purified powdered sucrose fatty acid ester with high HLB without using any solvent from a water-based sucrose fatty acid ester reaction mixture. By being able to provide a means to tighten the system, the following great effects can be achieved. (1) Sucrose fatty acid ester can be purified using only inexpensive water. (2) Since the sucrose fatty acid ester can be dried under normal pressure within a short time, there is no thermal deterioration of the product. (3) There is no need to worry about solvent explosion or fire, and therefore there is no need for expensive explosion-proof electrical equipment. (4) There is no concern that the reaction solvent or purification solvent will mix into the product. (5) Improve the sanitary environment at +111. (6) It can be industrialized at low cost.

[Brief explanation of the drawing]

FIG. 1 is a ternary graph showing the relationship between the ester composition of SE and its solubility in acidic water.

Claims (1)

[Claims] 1. In addition to the target sucrose fatty acid ester, unreacted sugar,
The aqueous sucrose fatty acid ester synthesis reaction mixture containing unreacted fatty acid methyl ester, catalyst, soap, and fatty acid is adjusted to a pH in the neutral range, and the resulting precipitate is acidified by adding water and neutral salts. After washing with water and ultrafiltering the washing liquid,
A method for producing a powdered high HLB sucrose fatty acid ester, which comprises spray drying. 2 The composition of the reaction mixture is: Unreacted sucrose = 1.0-80.0% Unreacted fatty acid methyl ester = 0.5-10.0% Catalyst = 0.05-7.0% Soap = 0. The method according to claim 1, wherein the fatty acid content is 5 to 60.0% and fatty acid = 0.5 to 10.0%. 3. The method according to claim 1, wherein the reaction mixture is adjusted to a pH of 6.2 to 8.2. 4. The method according to claim 1, wherein the reaction mixture after pH adjustment is heated to 50-80°C. 5. The method according to claim 1, wherein the weight ratio of water added to the reaction mixture and the reaction mixture is water:reaction mixture = 5:1 to 40:1. 6 The acid used to adjust the pH of the reaction mixture is lactic acid,
4. The method according to claim 1, wherein the acid is any acid selected from the group consisting of acetic acid, hydrochloric acid and sulfuric acid. 7 The fatty acid radical mainly contained in each of the fatty acid methyl ester, soap, and fatty acid in the reaction mixture has a carbon number of 1.
3. A method according to claim 1 or 2, having from 8 to 22 common saturated fatty acid roots. 8. The method according to claim 1 or 6, wherein the neutral salt added to the reaction mixture is any salt selected from the group consisting of common salt, mirabilite, potassium lactate, and potassium acetate. 9 Ester distribution of sucrose fatty acid ester is 10 to 75% as monoester content (diester or more is 80%
25%). 10. The method according to claim 1, wherein the acidic water has a pH value of 3.0 to 5.5. 11. Claim 1, wherein the temperature of the acidic water is 10 to 40°C.
or the method described in 10. 12. The method according to claim 1, wherein the ultrafiltration membrane is made of a polysulfone-based or polyvinylidene fluoride-based resin. 13 The molecular weight cutoff of the ultrafiltration membrane is 1,000-100
13. The method of claim 12, wherein the amount is 0.000. 14 The pressure as a driving source during ultrafiltration is 1.0 to 2.
The method according to claim 1, wherein the amount is 0.0 kg/cmG. 15 The pH of the reaction mixture aqueous solution during ultrafiltration is 6.2
8.2. 16 The temperature of the reaction mixture aqueous solution during ultrafiltration is 40~
The method according to claim 1 or 15, wherein the temperature is 60°C. 17. The method according to claim 1, wherein the slurry of the precipitate to be spray dried has a solids content of 4 to 40% and a moisture content of 96 to 60%. 18 The humidity and temperature of the blown air during spray drying are as follows: absolute humidity = 0.008 to 0.05 [(kg・water)/(k
The method according to claim 1, wherein the temperature is within the range of 10.0 to 100.0°C. 19. The manufacturing method according to claim 1, wherein the composition of the powdered sucrose fatty acid ester of the product is within the following range. Moisture = 0.5-5.0% Unreacted fatty acid methyl ester = 0.5-10.0% Soap = 0.5-60.0% Fatty acid = 0.5-10.0% Sucrose fatty acid ester = 98 .0~15.0%