MXPA96006649A - Glucuronilo-arabinaratos, its procedure debtention and applications of these products - Google Patents

Abstract

The present invention relates to a compound that is either (a) glucuronyl- (alpha, 1-3) -arabinárico acid, b) a glucuronil- (alfa, 1-3) arabinárico acid salt, (c) a polymer which consists essentially of a chain of anhydroglucuronyl units linked by alpha, 1-4 glycosidic linkages, the chain of which is linked by a (alpha, 1-3) glycosidic linkage to a terminal unit of the arabinárico acid, (d) a polymer such as in ( c) where some but not all of the anhydroglucuronyl units are replaced with anhydroglucosyl units, or (e) a salt of a polymer as in (c) or (

Description

GLUCURONILO-ARABINARATES, THE PROCESS FOR OBTAINING AND APPLYING THESE PRODUCTS The present invention relates to glucuronyl arabinarates as new industrial products. It also relates to a process for obtaining these products as well as to their application as sequestering and dispersing agents in the bleach compositions. Other features and advantages of the present invention will appear on reading the description given below. In the present invention, it is designated by the term glucuronyl-arabinarates not only glucuronyl acid (a 1-3) arabinárico (or its salts) but also to the polygluuronil-arabinaratos, which are molecules of polymeric nature constituted essentially by a chain of anhydro-glucuronicos reasons related to each other by an osídica relation (to, 1-4) and covalently bound by the same type of relationship (a, 1-3) to a terminal arabinárico acid unit. Subsequently, it will be said that glucuronyl (a, 1-3) arabinárico acid, composed of a glucuronil motif and a terminal unit of arabinárico acid, has a GP (degree of polymerization) of 2. A glucuronilo-arabinárico acid composed of two reasons glucuronil will possess a GP of 3 and so on.

In the products of the invention, these glucuronil motifs, also called anhydro-glucuronic, may alternate more or less frequently and more or less repetitively, with anhydro-glucosidic motifs also called glucosyl, that is to say non-oxidized ones. It is known that products whose structure resembles those of the present invention can be obtained: polyglucuronyl glycates by the action of nitric acid on cold starch (Food, Sci. Technol 1985, vol 14, chap. page 286, KIEBOOM and VAN BEKKUM). The polymers in question then comprise an anhydroglucuronyl motif for an approximately anhydroglucosyl motif and, unlike the products of the invention, their terminal unit is constituted by a glucaric acid. Other polygluzuronyl-glucarate containing more anhydroglucuronyl motifs with respect to the anhydroglucosyl motifs can be obtained according to the methods of international patent application WO 94/28030 by the action of dioxide or nitrogen tetroxide on starches. The polygluzuronyl-glucarate in question can comprise between 70 to 95% of anhydroglucuronyl motifs between 5 to 30% of anhydroglucosyl motifs. Other polygluconyl glucosides containing at least 90% anhydroglucuronyl motifs per 10% anhydroglucosyl motifs can be obtained by the process described in the international patent application WO 95/07303. The process described in this worldwide patent application consists of oxidizing starch hydrolysates by the action of hypohalites in the presence of catalytic amounts of a binary or tertiary alkyl nitroxyl such as l-oxy-2, 2,6,6-tetramethylpiperidine. However, this method does not serve to oxidize relatively heavy oligosaccharides (GP greater than 15) in its terminal hemiacetal or ketonic function. This results in that a substantial amount of high GP polyglucuronyl glucuronates remains within the lower GP polygluuronyl glycates and that the products obtained are not stable in alkaline or heat media. Glucosyl arabinonates, products whose structure also resembles the structure of the products according to the present invention, can be obtained by oxidative alkaline degradation of various disaccharides by air or oxygen. Under these conditions, as explained in German patent DE 618,164, maltose provides the glucosyl (a, 1-3) arabinonate or, as explained in US Pat. No. 4,618,675, palatinose provides the glucosyl (a, 1) -5) arabinonate. It is understood that these products are different from the present invention due to the fact that their terminal unit is an arabinonic acid and not an arabinárico acid. They are also different because the other constituent unit of the molecule is necessarily an anhydroglucosyl radical and not an anhydroglucuronyl radical. Nevertheless, products according to the invention may also contain anhydroglucosidic motifs since they also contain at least one anhydroglucuronyl motif and one terminal end of arabinárico acid. Finally, other products whose structure also resembles that of the products of the present invention can be obtained by the catalytic oxidation of starch hydrolysates by oxygen from the air and by catalysts of noble metal fixed on carbon as indicated in US Pat. No. 4,985. 553 of which the Applicant Company is a transferee. The products obtained by this process are polyglucosyl gluconates. All these glucuronyl-glucostes, glucosyl-arabinonates and glucosyl-gluconates of the prior art have carboxylic functions and, at various levels but like other carboxylic acids such as citric acid, gluconic acid or polyacrylic acids, have sequestering properties that allow these products act as "builders" or "cobuilders" in the leach formulations.

However, none of them brings together all the following qualities by themselves and to a certain degree: - high sequestering power, - high dispersing power, - high biodegradability - high stability, - interesting price, which are those that lend themselves to a "builder" or "cobuilder" perfect. In addition, the tendency is that bleach compositions become increasingly concentrated in really active products: surfactants, enzymes, bleaching agents, there is less room for the system "builder-cobuilder" whose main role is ultimately reduced to correct only the imperfections of the washing waters and, in particular, their content of alkaline earth salts. Therefore, it was necessary to carry out a product capable of serving as a "builder" or "cobuilder" in modern bleach compositions and having all the qualities mentioned above simultaneously. The Applicant Society realized that such a need could be met thanks to the glucuronyl arabinarates of the invention. At the end of numerous experiments, the Applicant Society demonstrated that it was possible to industrially manufacture such products with few raw materials and procedures.

COSTOSOS; - that the sequestering and dispersing powers of these products were of a level such that their use in the bleaches resulted in very low rates of redeposition and embedding rates of the fabrics washed with these lyes, - - that such products were easily biodegradable; - that such products were sufficiently stable to withstand at the same time the thermal pressures related to the drying process of the bleach compositions and the chemical pressures related to the stability of the organic molecules in these highly alkaline bleach compositions. Of the foregoing, the major drawback of the compositions of bleach of oxidized starch hydrolysates according to the prior art, whether it is glucuronyl-glucarate, glucosyl-arabinonates or glucosyl-gluconate, is the persistence, in these oxidized starch hydrolysates, of reducing hemiacetal ends unstable to heat and in alkaline medium. Of course such a defect is redhibitory and is discovered by a yellow-brown coloration of bleach powders or liquid liquors, at best after a short period of storage, in the worst case since its formulation. A particular procedure for obtaining the glucuronyl arabinarates according to the invention allows, as will be known later, to obtain products that do not have this defect. In the first instance, the present invention thus concerns glucuronyl-arabinarates as new products. Preferably, it concerns glucuronyl-arabinarate compositions having an average degree of polymerization greater than or equal to 2. Optimally, the products of the invention have an average degree of polymerization of between 2 and 50 and, excellently, between 2 and 10. This is explained by the fact that the glucuronyl-arabinarate compositions according to the invention having the preferred GP means, develop the highest sequestering powers. According to the present invention, the preferred glucuronyl-arabinarate compositions are those containing between 100% to 50% of anhydroglucuronyl motifs, preferably between 99% to 60% of anhydroglucuronyl motifs, this percentage being expressed in relation to the amount of anhydroglucuronyl and anhydroglucosyl motifs.

These preferences are explained by the fact that, on the one hand, it is difficult to completely oxidize all the primary alcohol functions of any polyglucan and, on the other hand, due to the fact that below the indicated thresholds, the sequestering and dispersing properties of glucuronyl-arabinarates no longer appear so satisfactorily during the use of these products in bleach formulations. Anyway, the compositions according to the invention contain less than 1%, preferably less than 0.7% and optimally less than 0.5% of free reducing sugars, expressed in free glucose equivalents and measured with the BERTRAND method. The reason for these preferences is that above the indicated limits, these free reducing sugars that reveal the presence of hemiacetalic extremes, would be the cause of too many marked phenomena of instability to the heat and the alkalinity of the bleach compositions in which the products would enter. of the invention. According to another aspect of the present invention, a process for obtaining the glucuronyl arabinarates according to the invention consists in: during a first stage, in proceeding to the oxidative alkaline degradation of a starch hydrolyzate in order to obtain glucosyl arabinonates, a second step, in proceeding to the selective oxidation of all or part of the primary alcohol functions of these glucosyl-arabinonates. In the present invention, the term "glycosyl arabinonates" includes glucosyl (a, 1-3) arabinonate as well as polyglycosyl arabinonates, ie, the molecules consisting of a chain of at least two anhydroglucosidic motifs covalently related to a terminal molecule of arabinonic acid. For starch hydrolyzate, the Applicant Company wants to designate all types of starch that suffered the action of acids or enzymes or both in order to obtain the solubility in water and the reduction of molecular mass. Accordingly, it is dextrins, maltodextrons, glucose syrups, maltose syrups and, in particular, those whose degree of average polymerization corresponds to the degree of average polymerization of the products of the invention that are preferred. By oxidative alkaline degradation, the processes consisting of subjecting aqueous solutions of oxidizable compounds to the action of finely divided air or oxygen in a very alkaline medium are designated. This oxidation can be catalyzed by various promoters, for example methylene blue as indicated in US Pat. No. 2,587,906 or by a redox couple consisting of anthraquinone-2-monosulfonic acid and hydrogen peroxide.

(HENDRICKS, KUSTER and MARÍN, Carb. Res, 214 (1991) 71-85).

This oxidation can be carried out at atmospheric pressure by means of air or under pressure by means of oxygen, as disclosed in US Pat. No. 4,125,559. Although these reactions of oxidative alkaline degradation of reducing sugars have always been carried out on mono- or disaccharides, such as glucose, mannose, fructose, maltose or lactose, the Applicant Society observed that the teaching of documents The above mentioned could also be extended to the polysaccharides provided with a reducing power provided by a hemiacetal or ketonic function. This reaction of oxidative alkaline degradation is translated by the formation, from a residue carrying this hemiacetalic or ketonic function, of a residue having lost a carbon atom and which becomes a carrier of a carboxylic function. From this carbon atom from the carrier residue of the reducing hemiacetal or ketonic function, formic acid is formed concomitantly. In this first stage of oxidative alkaline degradation according to the process according to the invention, consequently the various starch hydrolysate compounds namely glucose, maltose, oligoglucosyl-glucose and polyglycosyl-glucose are respectively converted into arabinonate, glucosyl -arabinonate, oligoglucosyl-arabinonate and polyglucosyl-arabinonate with simultaneous formation of formate. This reaction of alkaline oxidative degradation by appearing at least two molecules of acid (one molecule of arabinonate or of glucosyl-arabinonate and one molecule of formate) per molecule of reducing sugar made, it is necessary to foresee a sufficient alkaline reserve to carry out the reaction or add the alkali according to its consumption by reaction. In general, it is convenient to use between 2.1 to 3 moles and, preferably, between 2.2 to 2.4 moles of soda or potash per mole of hemiacetal or ketonic function to be oxidized; however other alkalis used in these same proportions may also agree. The concentration of the starch hydrolysates subjected to this oxidation step is of little importance as long as there are reactors provided with efficient agitation and aeration means. However, it is preferable to proceed to the step of oxidative alkaline degradation on aqueous solutions of starch hydrolyzate of a concentration of between 10 to 60% and, preferably, of 25 to 40% of dry matter. This oxidation stage being very exothermic, it is convenient to use reactors equipped with an efficient cooling device. It is preferred to carry out this oxidation step at a temperature between 20 and 70 ° C and, preferably, between 25 and 65 ° C. It is important to note that, in general, the lowest temperatures allow to obtain the best selectivities but to the detriment of the speed of reaction. Conversely, the higher temperatures allow to decrease the reaction time and can be used when a slight depolymerization of the starch hydrolyzate as well as the obtaining of percentages of carbonic, oxalic, glyceric, glycolic, lactic, erythronic, metasacarinic, dihydroxybutyric acids, etc ... are not detrimental to the correct development of the process nor to the use of the products obtained for the realization of the bleach compositions. When working or not in the presence of oxidation catalysts (methylene blue, anthraquinone-2-monosulfonic acid, hydrogen peroxide, ...), it is preferred to continue the reaction until obtaining a content of higher reducing sugars * measured by the BERTRAND method, between 0.1 and 0.2%, preferably between 0.2 and 1%, this content being expressed as a percentage by weight of glucose equivalent in relation to the dry matter content of the reactor. It will be noted that it would not be reasonable to prolong the reaction beyond this threshold of reducing sugars because the next stage will allow its reduction.

In fact it is one of the main advantages of the process of the invention to provide products whose content of reducing sugars is at such a low value that they almost no longer show any sensitivity to heat or alkaline media, even after prolonged storage periods. At the end of this oxidative alkaline degradation reaction, the catalyst is eventually extracted by percolating the reaction medium on a column of activated carbon, for example. The second step of the process according to the invention consists in selectively oxidizing all or a portion of the primary alcohol functions of the glucosyl arabinonates obtained in the previous step. It can be carried out in various ways. For example, the oxidation processes with nitric acid, dioxide or nitrogen tetraoxide can be used as indicated above. However, these procedures require the neutralization of the surplus of alkali necessary for carrying out the first stage and also force the product obtained after this first stage to dry. It is therefore preferred to proceed with this oxidation of the primary alcohol functions by an effective method in an alkaline medium and capable of using the surplus alkali used during the first stage. Also, as it is preferred to avoid an intermediate drying of the glucosyl arabinonate, it is preferred to use an effective method on the aqueous solutions of glucosyl arabinonates. A particularly preferred oxidation method according to the process according to the invention is that described in the international patent application WO 95/07303, which makes it possible to obtain poly-a-glucuronic acids from starch or inulin hydrolysates. In the process according to the invention, the glucosyl arabinonates obtained during the previous step are subjected to the action of a hypohalite in the presence of a catalytic amount of a binary or tertiary alkyl nitroxyl cation. Since this oxidation reaction develops best at a pH of between 9 and 13, the excess alkali necessary for carrying out the previous oxidation step is used very well. As in the aforementioned patent application, it is preferred to use as l oxidation catalyst l-oxy-2, 2, 6,6-tetramethylpiperidine, hereinafter referred to as TEMPO. During this oxidation reaction, the actual oxidant is the nitrosonium cation which is reduced in hydroxylamine when a primary alcohol function is oxidized as a function of the carboxylic acid. This nitrosonium cation is regenerated in situ by an oxidant easily constituted by a hypochlorite / bromide couple. During the reaction, a constant pH is maintained by the addition of a base which is preferably the same base as that used during the first oxidation step. All or a portion of the anhydroglucosyl motifs of the glucosyl arabinonates are thus oxidized in anhydroglucuronyl motifs and the terminal arabinonic acid is thus oxidized in arabinic acid. This reaction of oxidation of the primary alcohol functions is carried out according to this patent application WO 95/07303 at a temperature below 30 ° C, preferably between 0 and 5 ° C and at a dry matter concentration of 7 to 15 grams per liter of water approximately as indicated in patent application WO 95/0703. However, the Applicant Society observed that it was possible to use much higher concentrations and much higher temperatures up to 50 ° C without any problem, which translates into lower reactor volumes and the possibility of not using refrigeration units. TEMPO is added at a rate of between 0.1 to 2.5% by weight relative to the glucosyl-arabinonate weight to be oxidized in glucuronyl-arabinarate. The sodium hypochlorite is made at a rate of 2 moles per mole of primary alcohol to be oxidized.

In practice, however, it is preferred to use up to 10% NaOCl in excess relative to the stoichiometry of the reaction. Therefore sodium hypochlorite is made taking into account this excess, preferably at a ratio between 1.1 to 2.2 moles per mole of primary alcohol according to the desired degree of oxidation, which can vary from 50 to 100%. As a co-oxidant, sodium bromide can be added at a rate of between 0.1 to 1 mole and, preferably, at a rate between 0.2 to 0.5 mole per mole of NaCOl made in order to accelerate the oxidation reaction. In general, oxidation is complete after 1 hour. At this point, the content of reducing sugars in the reaction medium is still low and generally becomes less than 0.5%, generally at 0.2%. Subsequently, the extraction by ether of the reaction medium or, better said, its percolation is carried out on a column of granular activated carbon to remove the TEMPO. After the filtration of the purified reaction medium, it is generally proceeded to its concentration until a dry matter of 20% is obtained and, possibly, to its dehydration if it is desired that the products of the invention enter the composition of bleaches presented under the powder form.

Such dehydration is not necessary if it is desired to formulate liquid liquors. Also, if desired, it is possible, after concentration but before drying, to proceed with the elimination of the sodium chloride formed during the second stage of the process as well as the elimination of sodium bromide, which was optionally added as a co-oxidant, by techniques known to the artisan as ion exclusion chromatography on strong cationic resins. The example given below is intended to illustrate and ensure that the invention is better understood. Example 1; stage: oxidative alkaline degradation of a starch hydrolyzate In a fermentation apparatus equipped with glass vat BIOLAFITTE brand, with a useful capacity of 20 liters, introduce 2995 grams of water and 1591 grams of soda to form 4586 grams of a soda lye to 34.7%. In this lye 55 grams of anthraquinone-2-monosulfonate of sodium and 18.2 ml of hydrogen peroxide are added to 110 volumes. The fermentation apparatus is ventilated with an air flow rate of 20 liters per minute by stirring at a rate of 1000 revolutions per minute.

After having stirred this mixture at 25 ° C for 30 minutes, the temperature is raised to 45 ° C. A total of 18,344 grams of a glucose syrup obtained by acid hydrolysis of corn starch are added progressively and regularly in 3 hours and 30 30 minutes, with a dry matter of 50% and a GE of 37 (a mean degree of polymerization equal to 2.7). ). The temperature is then set at 55 ° C and agitation and ventilation are continued for 2 hours and 30 minutes. The content of reducing sugars in the reaction medium is reduced to 0.3 / 100g of dry matter of glucose syrup.

(Initially it was 37g / 100g). Subsequently the reaction medium is percolated on a column of granular activated carbon in order to remove the sodium salt of anthraquinone-2-monosulfonic acid. 2nd stage: selective oxidation of the primary alcohols functions of the alicosyl arabinonate In a stirred tank of a total volume of 35 liters containing 8 liters of water, 1146 grams of the solution obtained in the previous stage (corresponding to 459 g of dry matter of glucose syrup made in the previous stage) and the whole is cooled to 5 ° C. 42.7 grams of sodium bromide and 4.17 grams of TEMPO are added. After having left the dissolution of these ingredients, which lasts a few minutes, 2.9 liters of a solution of sodium hypochlorite at 157 g / l (water of javeline at 48 ° chlorometric) previously diluted to 25 is added at once. % and adjusted to a pH of 10.4 by hydrochloric acid. The temperature is maintained at 5 ° C by adding a little ice and the pH at 10.4 by continuous addition of 10% soda. After 60 minutes, the soda consumption becomes negative, indicating the end of the reaction. The TEMPO is extracted by percolation of the reaction medium on a column of granular activated carbon, and then the purified reaction medium is concentrated after filtration to a concentration of 20% dry matter. The crude glucuronil-arabinarate thus obtained reveals the following analysis, the percentages being expressed on the dry matter of the concentrated reaction medium: - Degradation products (oxalate, glycerate, glycolate, lactate ...) 1% - Active material (glucuronil-arabinaratos ) 39.6% - NaCl 51-5% - NaBr 3.1% - Formate 4.8% - Rate of sodium carboxylate (by weight of% active material) 17.5% Is a conversion rate that is close to 100% - Rate of reducing sugars (on total dry matter) 0.15% (about active material) 0.38 * - Degree of polymerization (GP) mean of active material 2.7% Example 2; The active substance of the product obtained in Example 1 was enriched by means of an ion exclusion chromatographic technique on strong cationic resins. Thus, a product consisting of only 5% sodium chloride and which was atomized to obtain a white powder. This powder was used to replace the polyacrylates in a bleach formula at the rate of 1 part of glucuronil-arabinarates thus enriched by 1 part of polyacrylates. Not only do the powders obtained not color during storage but also present very interesting bleach qualities because after having made 25 consecutive washings of samples of cotton and cotton / polyester fabrics, the whiteness indices obtained are superior to the polyacrylate control. In addition, the rate of organic inscrutations is significantly lower.

Claims (10)

1. CLAIMS 1. Glucuronilos-arabinaratos.
2. 2. Glucuronyl-arabinarate compositions with a mean degree of polymerization equal to or greater than 2.
3. 3. Compositions of glucuronyl-arabinarates with an average degree of polymerization of between 2 and 50 and, preferably, between 2 to 10.
4. 4. Compositions of glucuronilo-arabinaratos according to any of claims 1 to 3, characterized by containing between 100% and 50%, preferably between 99% and 60% of anhydroglucuronyl motifs.
5. 5. Glucuronyl-arabinarate compositions according to claim 4, characterized by containing less than 1%, preferably less 0.7% and optimally less than 0.5% free reducing sugars.
6. 6. Procedure for the manufacture of glucuronil arabinarates, characterized in that: - during a first stage, the oxidative alkaline degradation of a starch hydrolyzate is carried out in order to obtain glucosyl arabinonates, - during a second stage, in proceed to the selective oxidation of all or part of the primary alcohol functions of these glucosyl-arabinonates.
7. Process for the manufacture of glucuronyl arabinarates according to claim 6, characterized in that the second step is carried out by the action of a hypohalite in the presence of a catalytic amount of a binary or tertiary alkyl nitroxyl cation.
8. Process for the manufacture of glucuronyl arabinarates according to claim 7, characterized in that the binary or tertiary alkyl nitroxyl cation is the nitro-nionium cation.
9. Process for the manufacture of glucuronyl arabinarates according to one of claims 7 and 8, characterized in that the hypohalite is sodium hypochlorite and that it is carried out at a ratio of 1.1 to 2.2 moles per mole of primary alcohol to be oxidized.
10. 10. Use of glucuronil-arabinarates for the formulation of bleach compositions.