JP4729238B2 - Method of purifying a composition comprising an internal dehydration product of at least one hydrogenated sugar - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel process for the purification of compositions containing an internal dehydration product of at least one hydrogenated sugar.
The invention also relates to the preparation of the purified composition thus obtained, in particular in the preparation of polymeric or non-polymeric, biodegradable or non-biodegradable products or mixtures intended for the chemical, pharmaceutical, cosmetic and food industries. Also related to use.
[0002]
Finally, the present invention also relates to a novel product obtained according to the above process, but this kind of composition has specific characteristics regarding purity and a predetermined impurity content.
[0003]
The expression “hydrogenated sugar” for the purposes of the present invention is in particular:
Hexitol, such as sorbitol, mannitol, iditol, galactitol, etc.
Pentitol, such as arabitol, ribitol, xylitol, etc., and
Tetriitol, such as erythritol,
Is understood to mean
[0004]
The expression “internal dehydration product” is obtained by any method, in one or more steps, by removing one or more water molecules from the original internal structure of a hydrogenated sugar such as those described above, It is understood to mean any product.
[0005]
This is preferably an internal dehydration product of hexitol, in particular dianhydrohexitol or “isohexide”, for example isosorbide (1,4-3,6-dianhydrosorbitol), isomannide (1, 4-3,6-dianhydromannitol), or isoidide (1,4-3,6-dianhydroiditol).
[0006]
[Prior art]
Among these doubly dehydrated hydrogenated sugars, isosorbide is currently the most numerous industrial application being developed or at least planned. These are especially
The preparation of isosorbide = 2-nitrate, 5-nitrate, or 2,5-dinitrate useful in the therapeutic treatment of diseases, in particular heart and / or vascular diseases, as described in US 4,371,703;
Alkylated, especially dimethylated, especially useful as solvents for the preparation of pharmaceutical or cosmetic compositions (US Pat. No. 4,082,881) or also as active ingredients in oral hygiene compositions (European patent 315334) Preparation of a derivative of isosorbide;
Preparation of articles based on polyvinyl alcohol (US Pat. No. 4,529,666), polyurethane based (US Pat. No. 4,383,051) or polyester further comprising “terephthaloyl” type monomer units;
-Preparation of biodegradable gun condensate (International application WO99 / 45054);
The preparation of aqueous lacquers (US Pat. No. 4,418,174) or compositions having adsorption and / or coloring action (US Pat. No. 5,766,679);
About.
[0007]
For many of the above applications of isosorbide and other hydrogenated sugar internal dehydration products, especially other isohexides, it is generally necessary to subject the composition directly resulting from the actual ion dehydration process to a purification treatment. . This is particularly true for any hydrogenated sugar (eg, sorbitol) that is subjected to such a process during the process, in addition to the desired dehydration product (eg, isosorbide), various by-products such as:
Isomers of the desired product, for example isosorbide isomers such as isomannide and iidoide,
A product that is less dehydrated than the desired product or its isomer, such as sorbitan, mannitan, or iditan,
Derivatives resulting from oxidation or more generally degradation of the products mentioned above (these derivatives are for example deoxymonoanhydrohexitol, monoanhydropentitol, if the desired product is isosorbide, Including by-products such as monoanhydrotetritol, anhydrohexose, hydroxymethylfurfural, or glycerin),
-Derivatives resulting from the polymerization of the products mentioned above, and / or
・ Highly colored species, whose properties are not well clarified,
This is because it tends to be converted to.
[0008]
In general, all or some of these various categories of by-products or impurities are generated, regardless of the magnitude, during the actual process of dehydration of the hydrogenated sugar. Is irrelevant to the conditions and measures in the process, for example,
-Properties and form of dehydration acid catalyst used (inorganic acid, organic acid, cationic resin, etc.),
The amount of water or organic solvent in the initial reaction medium, or
・ Purity of hydrogenated sugar composition used as a raw material, such as sorbitol,
It should be noted that it is irrelevant.
[0009]
Various techniques have been recommended for the purpose of obtaining a composition with improved purity derived from the dehydration process, such as an isohexide composition, which adjusts the reaction conditions during the process. It may be an “direct” method, and / or an “indirect” method by applying one or more purification treatments after said step.
[0010]
By way of example, British Patent 613,444 describes the preparation of an isosorbide composition by dehydration in a water / xylene medium, which is then treated by distillation and then recrystallised from an alcohol / ether mixture. Is performed.
[0011]
A purification process combining distillation and recrystallization from lower aliphatic alcohols (ethanol, methanol) is also recommended in International Patent WO 00/14081. This document further shows that when distillation is the only possible purification step, it is advantageous to carry out the step in the presence of sodium borohydride.
[0012]
Another author has also performed the distillation step in the presence of a boron-containing compound, particularly in the presence of an anion resin pre-charged with borate ions or in the presence of boric acid, as described in U.S. Pat.No. 3,160,641. Recommended.
[0013]
US Pat. No. 4,408,061 and European Patent 323,994 describe the use of specific dehydration catalysts (gaseous hydrogen halide and liquid hydrogen fluoride, respectively), which are advantageously combined with a carboxylic acid as a cocatalyst. This is followed by distillation of the crude isosorbide or isomannide obtained.
[0014]
U.S. Pat. After seeding, crystallization from water is mentioned.
[0015]
European Patent 380,402 describes, as part thereof, dehydration of hydrogenated sugars in the presence of hydrogen under pressure and a specific catalyst based on a combination of copper and a Group VIII noble metal or gold. These conditions are said to be able to significantly reduce the formation of polymeric nature of impurities during the actual dehydration process.
[0016]
More recently, European Patent 915,091 describes the possibility of further advantageously reducing the production of such unwanted polymers by using an acid stable hydrogenation catalyst during the dehydration process.
[0017]
As a result of the above steps, the production of a high purity composition based on isohexide or other dehydrated hydrogenated sugar generally involves at least a predetermined time at least:
-Expensive things such as hydrogen with hydrogenation catalyst and cocatalyst,
Any use that is highly regulated in any case, such as organic solvents, and possibly dangerous for humans and the environment,
-Those that are not very effective in terms of yield, such as crystallization from water,
It is necessary to use any one of the means.
[0018]
Furthermore, the above patents generally do not address the issue of stability over time of the resulting purified composition, including those that are decolorized somewhat during the purification process.
[0019]
[Problems to be solved by the invention]
According to the applicants, in fact, so far a composition having, for example, a purity (dry / dry) of at least 98.5%, white (as a powder) or colorless (as a solution) and excellent stability It has not been possible to effectively prepare (e.g. isosorbide) in industrial practice without the need to continuously perform a distillation step followed by a crystallization step from an organic solvent.
[0020]
[Means for Solving the Problems]
In fact, the alternative route consisting of a simple distillation of the medium derived from the dehydration process and its conversion to a “massed” type composition by cooling, in particular in terms of purification (yellow to brown) ) And stability, it is impossible to obtain satisfactory results. By carrying out the further step of treating the pre-dissolved distillate with granular activated carbon before evaporation, a composition which is improved in terms of color can be obtained, but in terms of purity it is not improved at all. Furthermore, such compositions have a relatively limited stability over time. Applicants can obtain, after extensive research, a composition based on isohexide and other dehydrohydrogenated sugars of high purity and excellent stability without the need for a crystallization step from a solvent medium And this has been found to be possible by performing at least one decolorization step and at least one ion exchange step in a specific order.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
More particularly, the subject of the present invention is a method for the purification of a composition containing an internal dehydration product of at least one hydrogenated sugar comprising:
a) the optional step of treating the composition with at least one decolorizing means after or without redissolving;
b) subsequently treating the optionally decolorized composition with at least one ion exchange means;
c) subsequently treating the resulting composition with at least one decolorizing means;
A purification method characterized by comprising:
[0022]
According to one advantageous variant of the method, the method comprises:
a) treating the composition with activated carbon, preferably in granular form, after or without redissolving;
b) subsequently treating the resulting composition with at least one ion exchange means;
c) the subsequent treatment of the resulting composition with activated carbon, preferably activated carbon in granular form;
It is characterized by including.
[0023]
More preferably, the activated carbon used is
In step a) is in granular form,
In step c) it is in powder form.
[0024]
According to another variant, the ion exchange means used in step b) comprises at least one anionic resin and at least one cationic resin. Preferably, the means consists of a mixed bed of an anionic resin and a cationic resin, or a series of cationic resins followed by an anionic resin, or a series of anionic resins followed by a cationic resin. In a very advantageous way, the resins used are strong cationic resins and strong anionic resins.
[0025]
According to another embodiment of the process according to the invention, this is a process in which the composition obtained according to step c) is subjected to a concentration treatment in order to obtain a product “agglomerated” after optional filtration, and then optionally A step of carrying out the crystallization treatment, in particular comprising a step c) of carrying out the crystallization treatment by organic solvent and / or drying.
[0026]
The composition subjected to the purification method according to the present invention contains the internal dehydration product of at least one hydrogenated sugar as described above, and the dehydration may be complete or partial.
[0027]
In general, the composition comprises a mixture of several of these products, one of which predominates based on weight. The primary purpose of the purification process according to the invention is to give these compositions improved properties in terms of stability and coloration, while all other components contained in said compositions. Maintaining a specific hydrogenated sugar weight percentage at a dry matter ("DM") content and optionally increasing it.
[0028]
These compositions can be obtained according to the dehydration step described in any of the above-mentioned patent documents and subsequently according to any distillation step. Nevertheless, the method according to the invention is also advantageously applicable to compositions already purified by crystallization from a solvent medium or water, if desired, in which case the composition is It is generally redissolved as processed according to the invention.
[0029]
The composition subjected to the purification process according to the invention advantageously has an isohexide composition, i.e. regardless of its origin, its nature, its form of provision, and its composition, isohexide with one or more other isohexides. Or a composition containing it in a single form. In any case, the isohexide is most abundant in the composition and is generally the dominant species in DM.
[0030]
Thus, according to the predominantly weight-based nature of isohexide, this may in particular comprise an isosorbide, isomannide or isogalactide composition.
[0031]
According to a preferred variant, the composition subjected to the purification method according to the invention consists of an isosorbide composition.
[0032]
Applicants have surprisingly found that by using such a purification method, ie a combination of decolorization followed by a continuous ion exchange means, a composition improved in terms of stability can be obtained.
[0033]
The expression “stability” is understood to mean the stability of the composition over time, in particular with regard to pH change, electrical conductivity, and / or the content of certain impurities. These include in particular formic acid and generally ionic species, but not all of these products have been specifically studied in the prior art described above. Applicant believes that in any case, all or some of these products may serve as "accelerating" and / or "inducing agents" for the instability of the composition envisaged herein. .
[0034]
This result is based on experiments conducted by the Applicant, in particular the purified composition obtained by using the decolorization and ion exchange means individually or in combination in the reverse order (decoloration followed by ion exchange). It is even more surprising because it has been shown that it is quite impossible to obtain similar performance in terms of object stability.
[0035]
For example, when an isosorbide composition that has been passed through an activated carbon column in advance is passed through a strong anion resin and then a strong anion resin, the decolorized isosorbide thus obtained may have a destabilizing effect. Observed. Applicants have specifically noted that such use not in accordance with the present invention allows the isosorbide composition to be applied to the isosorbide composition even during short-term (2 days) storage at relatively low temperatures (60 ° C.) 1) overall Acidification (measurement of pH), in particular 2) producing formic acid, as well as 3) increasing the tendency to produce ionic species (overall measurement of electrical conductivity), leading to an undesirable effect I found out.
[0036]
In this case, when the second decolorizing means, which is powdered activated carbon, was used before the treatment with the resin, this tendency could not be remarkably reduced.
[0037]
Conversely, when similar activated carbon was used after treatment with the same resin, this was in accordance with the present invention, but strangely, during similar storage treatment, it was acidified to remove formic acid and ionic species. It was possible to obtain an isosorbide composition in which a clear decrease in the tendency to occur was observed.
[0038]
Thus improved compositions of isosorbide and isomannide, in particular for the preparation of an improved composition of isohexide and another dehydrated hydrogenated sugar (sorbitan, mannitan, iditan, galactitanium, xylitan, rivitan or erythritan) Simple and effective means are available for the preparation of
[0039]
By this means, in particular isosorbide or isomannide compositions,
The isosorbide or isomannide purity is at least 98.5%, preferably at least 99.0%;
The formic acid content in free and / or salt form is at most 0.01%,
(These percentages are expressed as dry weight relative to the total dry weight of the composition)
Preferably, the electrical conductivity is at most 20 microsiemens per centimeter (20 μS / cm),
The production of the composition becomes possible.
[0040]
The electrical conductivity is, if necessary, a value of 5% by diluting the dry matter (DM) content of the isosorbide composition by diluting it in distilled water or concentrating it under vacuum. It is measured according to test A, consisting of adjusting and then measuring the electrical conductivity of the 5% composition thus obtained.
[0041]
Surprisingly, by this means, especially when combined with a crystallization step before or after, an isosorbide composition can be produced, which is at least 99.5%, preferably at least 99.6%, eg as further exemplified It was characterized as having a purity on the order of 99.8%.
[0042]
The method according to the invention is also an isosorbide or isomannide composition, wherein the isosorbide or isomannide purity is at least 98.5%, preferably at least 99.0%,
The total monoanhydropentitol content is at most 0.1%, preferably at most 0.07%;
The total monodeoxy- and dideoxymonoanhydrohexitol content is at most 0.08%;
(These percentages are expressed as dry weight relative to the total dry weight of the composition)
Allows the production of the composition.
[0043]
As already mentioned, this method makes it possible to produce isosorbide compositions characterized as having a purity of at least 99.5%, preferably at least 99.6%.
[0044]
The content of isosorbide and other dehydrated hydrogenated sugars is conventionally measured by gas chromatography (GC).
[0045]
The formic acid content is conventionally measured by high performance liquid chromatography (HPLC).
[0046]
To the best of Applicants' knowledge, the isosorbide or isomannide composition thus characterized constitutes a new industrial product. Since these can be obtained according to the invention without necessarily including the step of crystallization from the organic solvent medium of step d) and / or using a final drying step, these compositions are advantageously May not contain any trace amount of organic solvent for a given application.
[0047]
The internal dehydration product of isosorbide and other hydrogenated sugars such as isomannide obtained by the present invention may be provided in various liquid or solid forms, particularly in the form of purified distillate, aggregated product, or It can be provided in the form of a mixture of well-divided crystals. Said solid form may have a further white color and a water content of at most 1%, preferably at most 0.6%, in particular 0.10 to 0.55%.
[0048]
In view of their purity, stability, and / or color properties, these compositions are used in many industries, especially synthetic intermediates, comonomers (including chain extenders), solvents, plasticizers, lubricants, fillers. As an agent, sweetener and / or active ingredient, advantageously used in the preparation of polymeric or non-polymeric, biodegradable or non-biodegradable products or mixtures intended for the chemical, pharmaceutical, cosmetic and food industries Can be done.
[0049]
The invention is explained in more detail with the aid of the following non-limiting examples.
[0050]
【Example】
(Example 1)
1 kg of a 70% DM-containing sorbitol solution and 7 g of concentrated sulfuric acid, marketed by the applicant under the name “NEOSORB® 70/02”, are charged into a coated stirred reactor. The resulting mixture is heated under vacuum (pressure is about 100 mbar) for 5 hours to remove the water contained in the original reaction medium and the water resulting from the sorbitol dehydration reaction.
[0051]
The crude reaction product is cooled to approximately 100 ° C. and then neutralized with 11.4 g of 50% sodium hydroxide solution. The neutralized isosorbide composition is then distilled under vacuum (pressure is about 50 mbar).
[0052]
The slightly colored (light yellow) crude isosorbide distillate is then dissolved in distilled water to give a solution containing 40% DM.
[0053]
This solution is then permeated through a “CECA DC 50” type activated carbon column at a rate of 0.5 BV / hour (bed volume / hour). The decolorized isosorbide composition thus obtained was then continuously fed through a column of “PUROLITE C 150 S” type strong cation resin and then a column of “AMBERLITE IRA 910” type strong anion resin at a rate of 2 BV / hour. And let it pass.
[0054]
This solution is then treated with powdered activated carbon of the “NORIT SX +” type at 20 ° C. for 1 hour.
The activated carbon used is in an amount of 5% expressed as dry weight / dry weight of solution.
[0055]
After filtration, the isosorbide solution is concentrated under vacuum. The resulting molten solid crystallizes in the form of large crystalline “agglomerated products” upon cooling, which is then ground to obtain a white powder having a moisture content of 0.3%, ie 99.7% DM.
[0056]
This isosorbide composition, obtained according to the present invention, has the following characteristics (percentages are expressed relative to the total weight of the composition).
Water: 0.3%
Isosorbide: 98.8%
Isomannide: 0.3%
Other dianhydrohexitols: 0.3%
Monoanhydropentitol: <0.025%
Deoxyhexitol: <0.070%
Formic acid: <0.0005%
pH *: 6.6
Electrical conductivity *: <20μS / cm
*: Measured after diluting the composition to DM 5%.
[0057]
The resulting composition is in accordance with the present invention, but has an isosorbide purity of 98.8 / 99.7, or about 99.1%.
[0058]
20 g of this isosorbide agglomerated product is placed in a co-plastic plastic container and stored in an oven at 60 ° C. After 2 days of storage under these conditions, the composition changed slightly with respect to pH (a decrease of 0.6 pH units), but in particular there was no significant change in its isosorbide purity, its formic acid concentration, and its electrical conductivity. It can be seen that the formic acid concentration and electrical conductivity are maintained at a very low level.
[0059]
(Example 2)
In these tests, the crude isosorbide distillate obtained in Example 1 is purified according to another variant not according to the invention, ie each according to the following:
Test 1: The distillate is crystallized in the form of agglomerated products just by treatment with granular activated carbon.
Test 2: The distillate is crystallized (aggregated) only by treatment with resin (strong anion followed by strong anion).
Test 3: The distillate is first treated with activated carbon, then treated with resin (strong anion followed by strong anion), and then crystallized (aggregated).
Test 4: The distillate is continuously treated with granular activated carbon followed by powdered activated carbon, then filtered, treated with resin, and crystallized (aggregated).
[0060]
All the isosorbide compositions immediately after obtained from these methods are in total,
Very little or significantly lower pH than that obtained in Example 1, ie pH from 5.6 (Test 2) to about 6.5 (Tests 3 and 4),
Electrical conductivity of less than 20 μS / cm (tests 2 to 4) or slightly higher (23 μS / cm—test 1), and
-Formic acid concentration less than 0.0005% or 5ppm (tests 2-4) or slightly higher (0.0015% or 15ppm-test 1),
It is observed that
[0061]
However, under storage conditions similar to those described in Example 1, all these compositions
At least 3 times, in particular 4 times (Test 4) to 5 times (Test 3) a significant pH reduction compared to the values observed in Example 1;
Generation of formic acid significantly more marked than in Example 1 (the level of formic acid further exceeds 0.01%, reaches 0.02% (Test 4), and further exceeds 0.04% (Test 3) 0.08% (Test 2)).
Indicates.
[0062]
Furthermore, the compositions derived from tests 2 and 3 reach an electrical conductivity of 40 μS / cm in only 2 days (test 3) and even exceed the value of 80 μS / cm (test 2) shows a very significant tendency to generate ionic species during storage.
[0063]
Thus, very surprisingly, as envisaged in Example 1 by the applicant, the method according to the invention which contemplates the use of the decoloring means after the ion exchange means is all described in Example 2. It is possible to obtain a composition that is much more stable than the composition obtained according to the above method, in this case, a composition of isosorbide.
[0064]
This improvement by the use of these two specific means in a specific order is achieved when these means are used separately (Tests 1 and 2) or when these means are combined but used in the reverse order (implementation In view of the respective effects obtained in Examples 3 and 4), it is even more unexpected.
[0065]
(Example 3)
In these tests, after obtaining a crude disorbate of isosorbide according to the present invention, it is processed in the same manner as in Example 1, but with certain variations, each with the following exceptions:
Test 5: The agglomerated product obtained in Example 1 is dissolved in methanol when heated. The resulting solution containing 75% DM is cooled to room temperature of about −15 ° C. and converted to a mixture of crystals that are more divided than the initial aggregated product.
Test 6: The sorbitol composition used as a raw material in the actual dehydration process was previously purified by chromatography using a “PCR 432” type PUROLITE column in calcium form.
Test 7: Distillation process with 0.5% NaBH _Four (Dry / Dry)
Test 8: After treatment with granular activated carbon, according to the present invention, a solution containing 40 DM%, treated with cationic and anionic resins and then with powdered activated carbon, was itself distilled. Crystallization of the resulting isosorbide aggregate product from methanol results from re-dissolution of the isosorbide crystals obtained according to a conventional method in water.
[0066]
All compositions obtained according to the invention have a water content of 0.1% (test 8) to 0.5% (test 5) and still (slightly) higher purity than the product from Example 1. The isosorbide purity is 99.2% (Test 7) to 99.6% (Tests 5, 6, and 8).
[0067]
It is actually surprising that such a level of purity (99.6%) is obtained, in particular without any crystallization step according to test 6.
[0068]
This product and that produced by tests 5, 7, and 8 actually have excellent stability and specific impurity levels during storage according to the present invention.
[0069]
Example 4
The crude distillate as obtained in Example 1 is dissolved in 2-propanol at a temperature of 60 ° C. to obtain a solution containing 75% dry matter (DM). The solution is then slowly cooled at 10 ° C. over 5 hours. Add recrystallized isosorbide seeds at 40 ° C.
[0070]
The crystals are then drained in a centrifuge and washed with a small amount of 2-propanol.
After drying under vacuum, the crystals are redissolved in water to obtain DM40%.
[0071]
This solution is permeated through a column of granular activated carbon (CPG 12-40) at a rate of 0.5 BV / hour. The isosorbide composition thus obtained is then passed continuously at a rate of 2 BV / hour through a column of a strong cation resin such as that described in Example 1 of this application and then through a column of a strong anion resin.
[0072]
The composition is then treated with powdered activated carbon of the “NORIT SX +” type for 1 hour at 20 ° C.
The activated carbon used is 0.2% expressed as dry weight / dry weight of the solution.
[0073]
After filtration, the isosorbide solution is concentrated under vacuum. The resulting molten solid crystallizes in the form of an agglomerated product upon cooling and is then ground to obtain a white powder having a water content of 0.2% moisture content.
[0074]
This isosorbide composition, obtained according to the present invention, has the following characteristics (percentages are expressed relative to the total weight of the composition).
Water: 0.2%
Isosorbide: 99.6%
Isomannide: not detected
Other dianhydrohexitols: 0.03%
Monoanhydropentitol: not detected
Deoxyhexitol: not detected
Formic acid: <0.0005%
pH *: 6.5
Electrical conductivity *: <20μS / cm

[0075]
Its isosorbide purity is therefore 99.6 / 99.8, ie about 99.8%.
[0076]
20 g of this isosorbide agglomerated product is placed in a co-plastic plastic container and stored in an oven at 60 ° C. It can be seen that after 14 days of storage, its isosorbide purity and its formic acid concentration have not changed.
[0077]
(Example 5)
700 g of mannitol, 300 g of water, and 21 g of concentrated sulfuric acid are charged to the coated stirred reactor. The resulting mixture is heated under vacuum (40 mbar) for 8 hours to remove moisture contained in the reaction medium and moisture from the mannitol dehydration reaction.
[0078]
The crude reaction product is neutralized with 50% sodium hydroxide solution. The isosorbide composition is then distilled under vacuum.
The crude distillate is then dissolved in water to give 40% DM.
[0079]
This solution is then permeated through a column of granular activated carbon (CPG 12-40) at a rate of 0.5 BV / hour. The isomannide composition thus obtained is then continuously passed through a column of strong cation resin such as that described in Example 1 and then a column of strong anion resin at a rate of 2 BV / hour.
[0080]
The composition is then treated with powdered activated carbon of the “NORIT SX +” type for 1 hour at 20 ° C.
The activated carbon used is in an amount of 5% expressed as dry weight / dry weight of solution.
[0081]
After filtration, the isomannide solution is concentrated under vacuum. The resulting molten solid crystallizes in the form of agglomerated products upon cooling and is then ground to obtain a white powder having a water content of 0.3% water content.
[0082]
This isomannide composition, obtained according to the present invention, has the following characteristics (percentages are expressed relative to the total weight of the composition):
Water: 0.5%
Isomannide: 98.0%
Isosorbide: 0.9%
Other dianhydrohexitols: 0.3%
Formic acid: <0.0005%
pH *: 6.5
Electrical conductivity *: <20μS / cm

[0083]
Its isomannide purity is therefore 98 / 99.5, ie about 98.5%.
[0084]
20 g of this agglomerated product of isomannide is charged into a co-plastic plastic container and stored in an oven at 60 ° C. It can be seen that after 14 days of storage, its isosorbide purity and its formic acid concentration have not changed.

Claims (11)

A method for the purification of a composition comprising at least one dianhydrohexitol comprising:
a) an initial step of distilling said composition;
The b) before SL composition, subsequently treating with at least one ion-exchange means;
c) a step of subsequently treating the resulting composition with activated carbon ;
A purification method comprising: a) an initial step of distilling said composition;
b) said composition, process subsequently treated with activated carbon particle-like form;
c ) subsequently treating the resulting composition with at least one ion exchange means;
step of d) resulting composition is treated with activated carbon continue can powdery form;
The method of claim 1, comprising: The method according to claim 1 or 2, characterized in that the ion exchange means comprises at least one strong anion resin and at least one strong cation resin. The composition obtained by step d), subjected to a concentration treatment in order to obtain the "agglomerated" product, then in subjecting the crystallization process by organic solvents及beauty Drying, step e) further comprise The method according to claim 1, characterized in that: At least one dianhydro f alkoxy compositions containing Torr, characterized in der Rukoto Lee Sosorubido or isomannide composition method according to any one of claims 1 to 4 above. An isosorbide or isomannide composition obtainable by the method according to any one of claims 1 to 5 ,
- isosorbide or isomannide purity, a 99.0% even without a small,
The formic acid content in free and / or salt form is at most 0.01%,
(These percentages are expressed as dry weight relative to the total dry weight of the composition)
- electrical conductivity, is the largest in the 20μS / cm,
The composition characterized by the above-mentioned. An isosorbide or isomannide composition according to claim 6 comprising
The total monoanhydropentitol content is at most 0.1 % ,
The total monodeoxy- and dideoxymonoanhydrohexitol content is at most 0.1 % ,
(These percentages are expressed as dry weight relative to the total dry weight of the composition)
The composition characterized by the above-mentioned. 8. Composition according to claim 6 or 7, characterized in that it has a purity of at least 99.5 % . And wherein the free of organic solvent, the composition according to any one of claims 6-8. - white, and 1% water content in-up,
The have the form of the purified distillate in the form of aggregate product, or characterized by Oh Rukoto in the form of a mixture of crystalline, set composition as claimed in any one of claims 6-9. Chemical, pharmaceutical, cosmetic, and contemplates the food industry, synthetic intermediates, comonomer containing a chain extender, a solvent, a plasticizer, a lubricant, a filler, as a sweetener, and / or active ingredient, polymeric or non-polymeric, in the preparation of biodegradable or non-biodegradable products or mixtures, the use of the set composition as claimed in any one of claims 6 to 10.