Crystalline forms of s,s-ethylenediamine-n,n'-disuccinic acid, respective methods and uses

Abstract

Described herein is a crystalline form of S,S-ethylenediamine-N,N'-disuccinic acid, selected from the group consisting of crystalline form B, crystalline form C and crystalline form F, as well as a composition comprising at least one of said crystalline forms of S,S-ethylenediamine-N,N'-disuccinic acid. Further is described herein the use of said crystalline forms of S,S-ethylenediamine-N,N'-disuccinic acid as stabilizing or complexing agents in detergent compositions and / or cosmetic compositions, or their use for the production of detergent compositions and / or cosmetic compositions. Moreover, methods of making of said crystalline forms of S,S-ethylenediamine-N,N'-disuccinic acid are described herein.

Description

Crystalline forms of S,S-ethylenediamine-N,N‘-disuccinic acid, respective methods and usesThe present invention relates to a crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid, selected from the group consisting of crystalline form B, crystalline form C and crystalline form F, as well as to a composition comprising at least one of said crystalline forms of S,S-ethylenediamine-N,N‘-disuccinic acid. The present invention further relates to the use of said crystalline forms of S,S-ethylenediamine-N,N‘-disuccinic acid as stabilizing or complexing agents in detergent compositions and / or cosmetic compositions, or to their use for the production of detergent compositions and / or cosmetic compositions. Moreover, the present invention relates to methods of making said crystalline forms of S,S-ethylenedia- mine-N,N‘-disuccinic acid. S,S-ethylenediamine-N,N‘-disuccinic acid [“(S,S)-EDDS”, CAS RN 20846-91-7] is a biodegradable chelating agent that, i.a., offers an alternative to ethylenediamine tetraacetic acid (“EDTA”), of which 80 million kilograms are produced annually. Under natural conditions, EDTA has been found to convert to ethylenediaminetriacetic acid and then to cyclize to the diketopiperazine, which accumulates in the environment as a persistent organic pollu- tant. (S,S)-EDDS was developed commercially as a biodegradable chelator and stabilizing agent in detergent and cosmetic formulations. When ethylenediamine-N,N‘-disuccinic acid (alsoreferred to as “EDDS” hereinafter) is applied in chemical-enhanced soil remediation inexcessive case (e.g., when applied for ex-situ soil washing), higher extraction efficiency for heavy metals can be achieved and the amount of extraction is less independent with the EDDS dosage. On the other hand, during soil remediation which involves continuous flushing, metal extraction is often limited by the amount of EDDS. Under EDDS deficiency, initial unselective extraction of heavy metals was observed, followed by heavy metal exchange and re-adsorption of heavy metals that have lower stability constant with EDDS.EDDS has two chiral centers, and as such, three stereoisomers. These are the enantiomeric (R,R)- and (S,S)- isomers and the achiral meso-(R,S)-isomer. As a biodegradable replacement for EDTA, only the (S,S)-stereoisomer is of interest. The (R,S)- and (R,R)- stereoisomers are less biodegradable, whereas the (S,S)-stereoisomer has been shown to be very effectively biodegraded even in highly polluted soils.EDDS was first synthesized from maleic acid and ethylenediamine. S.S-EDDS can be produced stereoselectively by the alkylation of an ethylenedibromide with L-aspartic acid. Racemic EDDS is produced by the reaction of ethylenediamine with fumaric acid or maleic acid. Some microorganisms have been manipulated for industrial-scale synthesis of S,S- EDDS from ethylenediamine and fumaric acid or maleic acid (see e.g. Takahashi, R.; et al. "Production of (S,S)-Ethylenediamine-N,N'-disuccinic Acid from Ethylenediamine and Fumaric Acid by Bacteria", Biosci. Biotechnol. Biochem. 63 (7) (1999), 1269-1273. doi: 10.1271 / bbb.63.1269).J.A. Neal et al. in Inorganic Chemistry, Vol. 7, No. 11 (1968) 2405-2412 discuss a hydrate form of a sodium cobalt (III) complex of EDDS, including a monohydrate form of EDDS. EDDS was prepared from L-aspartic acid and 1 ,2-dibromoethane.F.E. Scarborough et al. in Acta Cryst. B32 (1976) 2715- 2717 report of an N,N’-ethylenedi- aminedisuccinic acid pentahydrate, which corresponds to (S,S)-EDDS form A as discussed herein. EDDS was reported to have been prepared according to the method of Neal and Rose (1968).Document EP 1 033 362 A1 describes columnar crystals of S,S-ethylenediamine-N,N’- disuccinic acid with high bulk density and a method of obtaining the same.Document EP 0 267 653 A2 deals with a detergent composition containing ethylenedia- mine-N,N’-disuccinic acid.Document WO 98 / 24400 A2 reports of the use of bis(dicarboxylic acid) diaminoalkylene derivatives as biologically degradable complexing agents for alkaline earth metal ions and heavy metal ions.In the light of the existing prior art there is, however, still a need for a stable, uniform solid form of S,S-ethylenediamine-N,N‘-disuccinic acid with a defined water content as low as possible and a low hygroscopicity. Such a desired solid form of S,S-ethylenediamine-N,N‘- disuccinic acid (S,S-EDDS) is expected to have properties beneficial for use in industry, e.g. good storage stability under usual environmental conditions as well as under conditions of elevated temperature and humidity, lower molecular weight when compared with solid forms of S,S-EDDS with a higher water content, like known form A (which is an advantage during transportation and storage), and easier dosing (due to a stable, uniform stoichiometric composition).Correspondingly, it was a primary object of the present invention to provide stable, uniform solid forms of S,S-ethylenediamine-N,N‘-disuccinic acid with a water content as low as possible and with a low tendency to attract water (i.e. with low hygroscopicity).It was another object of the present invention to provide methods of making said stable, uniform solid forms of S,S-ethylenediamine-N,N‘-disuccinic acid as well as respective uses thereof, wherein the favourable properties of said solid forms of S,S-ethylenediamine-N,N‘- disuccinic acid would be particularly relevant.It has now been found that the primary object and other objects of the present invention can be accomplished by a crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid, selected from the group consisting of:- crystalline form B, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, or all of the following reflections, quoted as 20- values (in °): 10.7 ± 0.2, 13.2 ± 0.2, 15.7 ± 0.2 and 19.4 ± 0.2;- crystalline form C, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, at least four, or all of the following reflections, quoted as 20-values (in °): 9.1 ± 0.2, 18.2 ± 0.2, 19.0 ± 0.2, 20.3 ± 0.2 and 31 .9 ± 0.2; and- crystalline form F, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, at least four, at least five, or all of the following reflections, quoted as 20-values (in °): 9.1 ± 0.2, 13.9 ± 0.2, 19.3 ± 0.2, 20.9 ± 0.2, 21 .6 ± 0.2 and 35.1 ± 0.2.Crystalline form B of S.S-EDDS as described herein was found to be a dihydrate and thus has a considerably lower water content than the previously known pentahydrate of form A (see above). Form B of S.S-EDDS has also been found to be more stable than form A (shown e.g. by a lowertendency to loose water) and thus betterto dose and to characterize. Furthermore, form B is less hygroscopic, shows higher crystallinity and is easier to prepare (with a defined water content) than previously reported monohydrate forms of S.S-EDDS.Preferred is therefore a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form B of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein preferably said crystalline form B displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values (in °): 24.3 ± 0.2, 25.7 ± 0.2, 26.1 ± 0.2, 28.0 ± 0.2 and 30.9 ± 0.2.Also preferred is a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention (or a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form B displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation all of the following reflections, quoted as 20-values (in °): 10.7 ± 0.2; 13.2 ±0.2; 15.7 ± 0.2; 16.1 ± 0.2; 16.8 ± 0.2; 17.4 ± 0.2; 18.2 ± 0.2; 19.4 ± 0.2; 20.9 ± 0.2: 21 .4 ±0.2; 22.6 ± 0.2; 24.3 ± 0.2; 25.7 ± 0.2; 26.1 ± 0.2; 26.9 ± 0.2; 28.0 ± 0.2; 28.7 ± 0.2; 30.2 ±0.2; 30.9 ± 0.2; 31 .7 ± 0.2; 32.4 ± 0.2; 33.1 ± 0.2; 34.5 ± 0.2; 35.7 ± 0.2; 36.4 ± 0.2; 37.8 ±0.2; 38.5 ± 0.2.Crystalline form C of S.S-EDDS as described herein was found to be an anhydrate and thus has a considerably lower water content than previously known pentahydrate of form A (see above) and an even lower water content than form B as described herein. Form C of S.S-EDDS has also been found to be more heat-stable than both forms A and B and has been found to be stable under ambient conditions for at least three days. Moreover, form C of S.S-EDDS has been found to not be hygroscopic.Preferred is therefore a crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form C of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein preferably said crystalline form C displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values (in °): 24.4 ± 0.2, 24.9 ± 0.2, 25.8 ± 0.2, 30.7 ± 0.2 and 33.3 ± 0.2.Also preferred is a crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention (or a crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form C displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation all of the following reflections, quoted as 20-values (in °): 9.1 ± 0.2; 16.4 ± 0.2; 18.2 ± 0.2; 19.0 ± 0.2; 20.3 ± 0.2; 24.4 ± 0.2; 24.9 ± 0.2; 25.8 ± 0.2; 27.6 ± 0.2; 30.7 ± 0.2; 31 .9 ± 0.2; 33.3 ± 0.2; 37.9 ± 0.2; 38.5 ± 0.2.Crystalline form F of S,S-EDDS as described herein was also found to be an anhydrate and thus has a considerably lower water content than previously known pentahydrate of form A (see above) and an even lower water content than form B as described herein. Crystalline form F of S,S-EDDS has also been found to be more heat-stable than forms A, B and C and has further been found to be stable under ambient conditions for at least three months. Moreover, form F of S,S-EDDS has been found to not be hygroscopic.Preferred is therefore a crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form F of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein preferably said crystalline form F displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values (in °): 21.8 ± 0.2, 25.8 ± 0.2, 30.9 ± 0.2 and 33.9 ± 0.2.Also preferred is a crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention (or a crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form F displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation all of the following reflections, quoted as 20-values (in °): 9.1 ± 0.2; 13.9 ± 0.2; 16.4 ± 0.2; 18.2 ± 0.2; 18.9 ± 0.2; 19.3 ± 0.2; 19.6 ± 0.2; 19.9 ± 0.2; 20.3 ± 0.2; 20.9 ± 0.2; 21 .6 ± 0.2; 21 .8 ± 0.2; 22.5 ± 0.2; 23.5 ± 0.2; 24.2 ± 0.2; 24.9 ± 0.2; 25.8 ± 0.2; 26.3 ± 0.2;28.1 ± 0.2; 29.0 ± 0.2; 30.9 ± 0.2; 31 .6 ± 0.2; 32.1 ± 0.2; 33.3 ± 0.2; 33.9 ± 0.2; 35.1 ± 0.2;36.1 ± 0.2; 36.8 ± 0.2; 38.1 ± 0.2; 39.1 ± 0.2; 39.1 ± 0.2.Moreover is preferred a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form B of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form B is a dihydrate.Furthermore preferred is a crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form C of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form C is an anhydrate.And there is also preferred a crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein (or a crystalline form F of S,S-eth- ylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), wherein said crystalline form F is an anhydrate.The present invention also pertains to a composition, preferably selected from the group consisting of cleaning composition, detergent composition (preferably comprising water softener and / or water deionizer) and cosmetic composition (preferably selected from the group consisting of solid cleaning composition, solid detergent composition and solid cosmetic composition), comprising at least one crystalline form of S,S-ethylenediamine-N,N‘- disuccinic acid selected from the group consisting of crystalline form B according to the present invention (or a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), crystalline form C according to the present invention (or a crystalline form C of S,S-ethylenediamine-N,N‘- disuccinic acid according to the present invention as described herein as being preferred) and crystalline form F according to the present invention (or a crystalline form F of S,S- ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred).Generally, all aspects of the present invention discussed herein in the context of the crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein apply mutatis mutandis o the composition comprising at leastone crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein, and vice versa.It was found by the present inventors that solid forms B, C and F of S.S-EDDS as described herein are stable, uniform solid forms of S,S-ethylenediamine-N,N‘-disuccinic acid with low water contents (or no defined water content, respectively) and a low hygroscopicity (or showing no hygroscopicity, respectively). A composition comprising one or more of such solid forms of S.S-EDDS therefore has beneficial properties, e.g. good storage stability under usual environmental conditions as well as under conditions of elevated temperature and humidity, and a highly defined content of S.S-EDDS (due to its stable, uniform stoichiometric composition).The present invention then also pertains to the use of a crystalline form of S,S-ethylenedi- amine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B according to the present invention (or a crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), crystalline form C according to the present invention (or a crystalline form C of S,S-ethylenediamine- N,N‘-disuccinic acid according to the present invention as described herein as being preferred) and crystalline form F according to the present invention (or a crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred), as a stabilizing agent or complexing agent in cleaning compositions, detergent compositions and / or cosmetic compositions, or for the production of cleaning compositions, detergent compositions and / or cosmetic compositions, preferably on industrial scale.Generally, all aspects of the present invention discussed herein in the context of the crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or of the composition comprising at least one crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein, apply mutatis mutandis io the use of a crystalline form of S,S-ethylenedia- mine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein, and vice versa.Due to their beneficial properties, in particular due to their good storage stability under usual environmental conditions as well as under conditions of elevated temperature and humidity, and due to their easy dosing (due to their stable, uniform stoichiometric compositions), thecrystalline forms B, C and F of S.S-EDDS as described herein, or their mixtures, are particularly suited for use in the production of detergent compositions and / or cosmetic compositions in industry. This is particularly true where larger quantities of said solid forms of S,S- EDDS need to be transported, stored and / ordosed for industrial use, e.g. forthe production of detergent compositions and / or cosmetic compositions in industry.The publication IPCOM000274907D published on www.IP.com is regarded as Reference RF1 , which is incorporated herein by reference in its entirety. The publication Prior Art Disclosure; Issue 684; paragraphs

[3000] to

[3061] ; ISSN: 2198-4786; published: February 12, 2024 will be regarded as Reference RF2, which is incorporated herein by reference in its entirety.The phrase "cleaning composition", as used herein, includes compositions and formulations designed for cleaning soiled material. Such compositions and formulations include those designed for cleaning soiled material or surfaces of any kind, more preferably compositions for Fabric and Home Care. “Cleaning compositions” are defined in more detail in paragraphs

[0001] ,

[0002] ,

[0004] and

[0007] of Reference RF1.“Compositions for Fabric and Home Care” include cleaning compositions and formulations including but not limited to laundry cleaning compositions and detergents and hard surface cleaning compositions including dish washing compositions, more preferably liquid laundry formulations, solid laundry compositions, liquid manual dish wash formulations, automatic dish wash (ADW) gels and automatic dish wash (ADW) solid compositions. “Compositions for Fabric and Home Care” are defined in more detail in paragraph

[0003] of Reference RF1.The cleaning compositions of the invention including the (or at least one of the) inventive crystalline form(s) of S,S-ethylenediamine-N,N‘-disuccinic acid (i.e. forms B, C and F, as specified above - also referred to hereinafter as the “inventive builder(s)”) may - and preferably do - contain adjunct cleaning additives (also abbreviated herein as “adjuncts”), such adjuncts being preferably in addition to a surfactant system as defined before.Suitable adjunct cleaning additives include polymers, surfactants or surfactant systems, further builders, cobuilders, enzymes, enzyme stabilizing systems, structurants or thickeners, clay soil removal / anti-redeposition agents, solubilizing agents, chelating agents, bleaching compounds, bleaching agents, bleach activators, bleach catalysts, brighteners, malodor control agents, pigments, dyes, opacifiers, hueing agents, dye transfer inhibitingagents, chelating agents, suds boosters, suds suppressors (antifoams), color speckles, silver care, anti-tarnish and / or anti-corrosion agents, alkalinity sources, pH adjusters, pH- buffer agents, hydrotropes, scrubbing particles, antibacterial agents, anti-oxidants, softeners, carriers, processing aids, pro-perfumes, dye fixation agent and perfumes.In preferred embodiments, the cleaning compositions comprise the inventive builder(s) (as specified above) and a polymer, preferably cleaning polymers and / or soil release polymers. “Cleaning polymers and soil release polymers” are defined in more detail in paragraphs

[0032] to

[0034] of Reference RF1 . These polymers include polycarboxylates, alkoxylated polyalkylenamines, alkoxylated polyalkylenimines, polyether-based polymers, rheologymodifying polymers, dye inhibition polymers and soil release polymers as defined in more detail in paragraphs

[3035] to

[3044] of Reference RF2.Polymers may include, without limitation, “multifunctional alkoxylated polyethylene imines”, “multifunctional alkoxylated diamines” and also terephthalic acid-based polyesters like Clariant’s TexCare®, such as TexCare® SRN 170, TexCare® SRN 172, TexCare® SRN 260, TexCare® SRN 260 SG Terra and TexCare® SRA 300 as well as distinct combinations of all of the before mentioned polymers. Also included are graft polymers comprising a polyalkylene oxide based backbone with grafted side chains of vinyl ester monomer and optionally N-vinylpyrrolidone monomers.In preferred embodiments, the cleaning compositions comprise the inventive builder(s) (as specified above) and a surfactant or surfactant system. “Surfactants” are anionic, non-ionic, cationic, amphoteric and zwitter-ionic surfactants defined in more detail in paragraphs

[3008] to

[3034] of Reference RF2. In addition, these surfactants are also described in more detail in paragraphs

[0008] to

[0013] of Reference RF1 .Anionic surfactants for inventive cleaning compositions include linear alkylbenzenesulfonates (LAS), alkyl sulfates (AS), alkyl alkoxy sulfates (AES), alkyl alkoxy carboxylates, modified alkylbenzene sulfonate (MLAS), methyl ester sulfonate (MES), alkyl sulfosuccinates, alpha-olefin sulfonate (AOS), alkyl polyglycosides (APG) and biosurfactants, such as rhamnolipids and sophorolipids. Non-ionic surfactants for inventive cleaning compositions include alkoxylates, alkoxylated alcohols, alkoxylated fatty acids and alkoxylated (polysaccharides. Cationic surfactants for inventive cleaning compositions include surfactants comprising a quaternary ammonium. Amphoteric surfactants for inventive cleaning compositions include amine oxides. Zwitter-ionic surfactants for inventive cleaning compositions include betaines.In preferred embodiments, the cleaning compositions comprise the inventive builder(s) (as specified above) and an additional builder. “(Additional) builders” are defined in more detail in paragraphs

[0014] to

[0018] of Reference RF1. These builders include non-phosphate based builders (NPB) and phosphonates (CoP) described in more detail in paragraphs

[3001] to

[3005] of Reference RF2.Additional builders may include, without limitation, methylglycinediaceticacid (MGDA), ethylenediaminedisuccinic acid (EDDS, any isomers thereof), glutamic acid diacetate (GLDA), citric acid and salts thereof. In preferred embodiments, the cleaning compositions comprise the inventive builder(s) and an enzyme. “Enzymes” are defined in more detail in paragraphs

[0020] to

[0027] of Reference RF1 .Enzymes may include hydrolases, such as proteases, amylases, lipases, DNases, cellulases, hemicellulases, phospholipases, esterases, mannanases, xylanases, dispersins, ox- idoreductases, cutinases, pectate lyases, pectinases, lactases and peroxidases. In more preferred embodiments, the cleaning composition comprises, in addition to the inventive builder(s), a protease and a protease stabilizing system comprising a peptide aldehyde.In preferred embodiments, the cleaning compositions comprise the inventive builder(s) and a biocide. “Biocides” are defined in more detail in paragraphs

[0035] and

[0036] of Reference RF1 . These biocides also include compounds as defined in more detail in paragraphs

[3006] and

[3007] of Reference RF2.Biocides may include, without limitation, 2-phenoxyethanol and 4,4’-dichoro 2-hydroxydi- phenylether.Further adjunct cleaning additives are included and described in more detail in paragraphs

[0005] ,

[0006] ,

[0019] ,

[0028] to

[0031] and

[0037] to

[0039] of Reference RF1.Liquid laundry formulations, solid laundry compositions, liquid manual dish wash formulations, automatic dish wash (ADW) gels and automatic dish wash (ADW) solid compositions comprising inventive builder(s) are defined in more detail in paragraph

[0043] of Reference RF1.The present invention further pertains to a method of making and / or isolating solid (crystalline) form B of S,S-ethylenediamine-N,N‘-disuccinic acid (also referred to as “S,S-EDDS”), at least comprising the steps:51) providing or preparing solid (crystalline) form A of S.S-EDDS, or a mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S,S- EDDS hydrates, preferably comprising solid form B of S.S-EDDS; and52) subjecting the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid (crystalline) form B of S.S-EDDS, as provided or prepared in step S1), to reduced pressure of < 30 hPa and to a temperature in the range of from > 60 to < 90 °C, to constant weight (or until constant weight is reached); preferably to receive solid (crystalline) form B of S.S-EDDS, or to receive a mixture that comprises a higher proportion of solid (crystalline) form B of S.S-EDDS than an (or than the) initial mixture as (was) provided or prepared in step S1), preferably as determined according to one or more than one method selected from the group consisting of powder X-ray diffraction (also abbreviated to “PXRD” hereinafter), Karl Fischer water titration and thermogravimetric analysis; preferably wherein said mixture that comprises a higher proportion of solid (crystalline) form B of S.S-EDDS than an (or than the) initial mixture as provided or prepared in step S1) comprises > 85 mass-%, more preferably > 90 mass-%, of solid (crystalline) form B of S,S- EDDS, preferably as determined according to one or more than one method selected from the group consisting of powderX-ray diffraction, Karl Fischer water titration and thermogravimetric analysis.Generally, all aspects of the present invention discussed herein in the context of the crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or of the composition comprising at least one crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein and / or to the use of a crystalline form of S,S-ethylenediamine-N,N‘-disuc- cinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein, apply mutatismutandis to the method of making and / or isolating solid form B of S,S-ethylenediamine- N,N‘-disuccinic acid, and vice versa.S.S-EDDS can be prepared from L-aspartic acid and 1 ,2-dibromoethane, as described by J.A. Neal et al. in Inorganic Chemistry, Vol. 7, No. 11 (1968) 2405-2412. Solid (crystalline) form A of S.S-EDDS can be obtained as reported in F.E. Scarborough et al. in Acta Cryst. B32 (1976) 2715- 2717. Solid (crystalline) form A of S.S-EDDS or a mixture comprising solid (crystalline) form A of S.S-EDDS and optionally other solid (crystalline) forms of S,S- EDDS hydrates, in particular further comprising solid (crystalline) form B of S.S-EDDS, can also be prepared from e.g. ethylenediamine and fumaric acid in a biocatalytic process involving an EDDS synthase, as is further explained and disclosed below.As used herein, an “EDDS synthase” is an enzyme, which catalyzes the formation of eth- ylenediamine-N,N'-disuccinic acid and has a broad substrate spectrum. Otherterms of this enzyme are known to the person skilled in the art and include e.g. the term “EDDS lyase”.Biocatalytic processes producing S.S-EDDS and involving an EDDS synthase are known and are e.g. described in document EP 1 043 400 A1 , or by Yang et al. in Process Biochemistry 97 (2020) 96-103, or by Takahashi et al. in Biosci. Biotechnol. Biochem. 63 (7) (1999), 1269-1273. As was confirmed by own experiments, processes (including biocatalytic processes) wherein S.S-EDDS is produced and recovered as a product from aqueous media and dried under ambient conditions (about room temperature, which is 25 °C as used herein; ambient pressure) usually yield solid form A of S.S-EDDS (i.e. a pentahydrate).It has been found that crystalline form A of S,S-ethylenediamine-N,N‘-disuccinic acid displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation the following most prominent reflections, quoted as 20-values (in °): 10.0 ± 0.2, 12.4 ± 0.2, 14.7 ±0.2, 16.0 ± 0.2, 17.9 ± 0.2, 18.9 ± 0.2, 20.0 ± 0.2, 20.2 ± 0.2, 21.8 ± 0.2, 22.5 ± 0.2, 23.3 ±0.2, 24.4 ± 0.2, 24.9 ± 0.2, 25.9 ± 0.2, 28.6 ± 0.2, 29.3 ± 0.2, 30.8 ± 0.2, 31 .3 ± 0.2, 31 .6 ±0.2, 32.2 ± 0.2, 34.4 ± 0.2, 36.2 ± 0.2, 36.7 ± 0.2 and 37.8 ± 0.2.Even more prominent reflections of crystalline form A of S,S-ethylenediamine-N,N‘-disuc- cinic acid in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation are the following, quoted as 20-values (in °): 10.0 ± 0.2, 14.7 ± 0.2, 17.9 ± 0.2, 18.9 ± 0.2, 20.2 ± 0.2, 21 .8 ± 0.2, 22.5 ± 0.2, 24.9 ± 0.2, 25.9 ± 0.2, 29.3 ± 0.2, 30.8 ± 0.2, 34.4 ± 0.2 and 36.7 ± 0.2.Preferred is a method of making and / or isolating solid (crystalline) form B of S,S-ethylene- diamine-N,N‘-disuccinic acid as described herein (or a method of making and / or isolating solid form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred) wherein in step S1) the solid (crystalline) form A of S.S-EDDS or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, is provided resulting from a biocatalytic production process or prepared by a biocatalytic production process (preferably involving an EDDS synthase); and / or in step S2) the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, as provided or prepared in step S1), is subjected to reduced pressure in the range of from > 10 hPa to < 30 hPa and to a temperature in the range of from > 60 to < 85 °C, preferably in the range of from > 65 to < 82 °C, to constant weight (or until constant weight is reached).It has been found by own experiments that solid dihydrate (crystalline) form B of S.S-EDDS can be obtained under the specific conditions of temperature and reduced pressure as defined here above from solid (crystalline) forms of S.S-EDDS hydrates which have a higher water content, in particular from solid (crystalline) pentahydrate form A of S.S-EDDS.The present invention also pertains to a method of making and / or isolating solid (crystalline) form C of S,S-ethylenediamine-N,N‘-disuccinic acid, at least comprising the steps:51) providing or preparing solid (crystalline) form A of S.S-EDDS, or a mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S,S- EDDS hydrates, preferably comprising solid form B of S.S-EDDS; and52) subjecting the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, as provided or preparedin step S1), to a temperature in the range of from > 120 to < 165 °C, preferably to constant weight (or until constant weight is reached), preferably for a duration in the range of from > 5 min. to < 5 hours (depending on the amount / mass of the solid (crystalline) form A of S.S-EDDS, orthe mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S,S- EDDS hydrates which was used at the start of step S2)); preferably to receive solid (crystalline) form C of S.S-EDDS.Generally, all aspects of the present invention discussed herein in the context of the crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or of the composition comprising at least one crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein and / or to the use of a crystalline form of S,S-ethylenediamine-N,N‘-disuc- cinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or to the method of making and / or isolating solid form B of S,S-ethylenediamine-N,N‘-disuccinic acid, apply mutatis mutandis to the method of making and / or isolating solid form C of S,S- ethylenediamine-N,N‘-disuccinic acid, and vice versa.Preferred is a method of making and / or isolating solid (crystalline) form C of S,S-ethylene- diamine-N,N‘-disuccinic acid as described herein (or a method of making and / or isolating solid (crystalline) form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred) wherein in step S1) the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, is provided resulting from a biocatalytic production process or prepared by a biocatalytic production process; and / or in step S2) the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, as provided or prepared instep S1), is subjected to a temperature in the range of from > 130 to < 160 °C, preferably in the range of from > 135 to < 155 °C, preferably to constant weight (or until constant weight is reached), preferably for a duration in the range of from > 10 min. to < 4 hours (depending on the amount / mass of the solid (crystalline) form A of S.S-EDDS, or the mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates which was used at the start of step S2)).It has been found in own experiments that solid anhydrate (crystalline) form C of S.S-EDDS can be obtained under the specific conditions of temperature as defined above from solid (crystalline) forms of S.S-EDDS hydrates, in particular from solid (crystalline) pentahydrate form A of S.S-EDDS.The present invention also pertains to a method of making and / or isolating solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid, by recrystallizing solid form A of S.S-EDDS, or a mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates (preferably a mixture comprising solid forms A and B of S.S-EDDS), in an organic solvent, preferably until completion of re-crystallization (preferably process monitoring using PXRD); and / or wherein the method at least comprises the steps:51) providing or preparing solid (crystalline) form A of S.S-EDDS, or a mixture comprising solid (crystalline) form A of S.S-EDDS and other solid (crystalline) forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, in an organic solvent, to receive a solution or suspension (preferably a suspension); and52) subjecting the solution or suspension as received in step S1) to a temperature in the range of from > 65 to < 130 °C once (one time) or more than once (more than one time, preferably several times), preferably with intermittent cooling to room temperature;preferably until solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid has formed, preferably as determined by powder X-ray diffraction; and / or for a duration in the range of from > 1 hour < 24 hours each time; preferably to receive (preferably solely) solid (crystalline) form F of S,S-EDDS.Generally, all aspects of the present invention discussed herein in the context of the crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or of the composition comprising at least one crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein and / or to the use of a crystalline form of S,S-ethylenediamine-N,N‘-disuc- cinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to the present invention as described herein and / or to the method of making and / or isolating solid form B of S,S-ethylenediamine-N,N‘-disuccinic acid and / or to the method of making and / or isolating solid form B of S,S-ethylenediamine-N,N‘- disuccinic acid, apply mutatis mutandis io the method of making and / or isolating solid form F of S,S-ethylenediamine-N,N‘-disuccinic acid, and vice versa.The organic solvent in which solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates (preferably a mixture comprising solid forms A and B of S.S-EDDS) is recrystallized, or which is used in step S1) as defined here above, preferably is a dipolar aprotic organic (preferably water-miscible) solvent or a mixture of such dipolar aprotic organic (preferably water-miscible) solvents, more preferably an aprotic dipolar organic (preferably water-miscible) solvent, wherein preferably said dipolar aprotic solvent (or each respective dipolar aprotic solvent in a respective mixture) has a boiling point sufficiently high so that applying the desired temperature to the solution or suspension in step S2) is possible. The skilled person knows respective organic solvents and can select appropriate organic solvents, ortheir mixtures, accordingly. A dipolar aprotic organic (preferably water-miscible) solvent as used in the abovedescribed method according to the present invention preferably has a water content of < 5 %, more preferably of < 3 % and still more preferably of < 1 %.The term “until completion of re-crystallization” as used here above, forthe purposes of the present invention preferably means that the solid (crystalline) form F of S.S-EDDS as received by the method of making and / or isolating solid form F of S,S-ethylenediamine-N,N‘- disuccinic acid described above, does not contain more than 5 mass-% of hydrates of S,S- EDDS, as determined according to one or more than one method selected from the group consisting of powder X-ray diffraction, Karl Fischer water titration and thermogravimetric analysis.Where in step S2) of the method of making and / or isolating solid (crystalline) form F of S,S- ethylenediamine-N,N‘-disuccinic acid as described here above the solution or suspension as received in step S1) is subjected to a temperature in the range of from > 65 to < 130 °C once or more than once until solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuc- cinic acid has formed, step S2) is preferably carried out until form F of S.S-EDDS is the only solid form of S.S-EDDS present at the end of step S2), preferably as determined by powder X-ray diffraction. Step S2) may, however, also be carried out until a desired (lower) proportion (or amount) of form F of S.S-EDDS has formed in step S2) (preferably as determined by powder X-ray diffraction, process monitoring).Preferred is a method of making and / or isolating solid (crystalline) form F of S,S-ethylene- diamine-N,N‘-disuccinic acid as described herein (or a method of making and / or isolating solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention as described herein as being preferred) wherein the solid form A of S.S-EDDS or the mixture comprising solid form A of S,S- EDDS and other solid forms of S.S-EDDS hydrates, preferably comprising solid form B of S.S-EDDS, preferably as provided or prepared in step S1), is provided resulting from a biocatalytic production process (preferably involving an EDDS synthase) or prepared by a biocatalytic production process (preferably involving an EDDS synthase); and / or wherein in step S2) the solution or suspension as received in step S1) is subjected to a temperature in the range of from > 65 to < 120 °C, preferably in the range of from > 65 to < 110 °C, several times (preferably > two times to < five times), preferably with intermittent cooling to room temperature; preferablyuntil solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid has formed, preferably as determined by powder X-ray diffraction; and / or for a duration in the range of from > 90 minutes < 18 hours each time; and / or wherein the organic solvent, preferably the organic solvent in step S1), is a dipolar aprotic, preferably water-miscible, solvent, preferably selected from the group consisting of 1 ,4-dioxane, dimethyl formamide, dimethylsulfoxide and mixtures thereof, more preferably the organic solvent in step S1) comprises or is 1 ,4-dioxane (preferably 1 ,4-dioxane with a water content < 5 mass-%, more preferably 1 ,4-dioxane with a water content < 3 mass-%, and even more preferably 1 ,4-dioxane with a water content of < 1 mass-%); and / or further comprising the (additional) step:S3) isolating any precipitate received from step S2), preferably by filtration, and subjecting the isolated precipitate to reduced pressure of < 30 hPa and a temperature in the range of from > 15 to < 90 °C, preferably of from > 15 to < 60 °C, more preferably of from > 15 to < 40 °C, preferably to constant weight (or until constant weight is reached), preferably for a duration in the range of from > 4 to < 24 hours, more preferably of from > 6 to < 12 hours.In a preferred variant of the method of making and / or isolating solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to the present invention, the solution or suspension (preferably the suspension) as received in step S1) is subjected to a temperature in the range of from > 65 to < 120 °C, preferably in the range of from > 65 to < 110 °C, two times, or three times, or four times, or five times, preferably for a duration in therange of from > 90 min. to < 8 hours each time, preferably with intermittent cooling to room temperature.It has been found in own experiments that anhydrate (crystalline) form F of S.S-EDDS can be obtained under the specific conditions of temperature and reduced pressure as defined above from solid (crystalline) forms of S.S-EDDS hydrates, in particular from solid (crystalline) pentahydrate form A of S.S-EDDS.Without wishing to be bound by theory, it is presently assumed that anhydrate (crystalline) form F of S.S-EDDS may be a better crystalline version of anhydrate (crystalline) form C of S.S-EDDS, as might be concluded from a comparison of the respective PXRD diagrams.The present invention is further described and illustrated with reference to the figures appended herewith.Fig. 1 : Fig. 1 shows an X-ray powder diffraction diagram of the crystalline S,S-ethylene- diamine-N,N‘-disuccinic acid form A, measured at 25 °C and using Cu Ka-radia- tion.Fig. 2: Fig. 2 shows an X-ray powder diffraction diagram with marked peak positions of the crystalline S,S-ethylenediamine-N,N‘-disuccinic acid form A, measured at 25 °C and using Cu Ka-radiation.Fig. 3: Fig. 3 shows an X-ray powder diffraction diagram of the crystalline S,S-ethylene- diamine-N,N‘-disuccinic acid form B according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 4: Fig. 4 shows an X-ray powder diffraction diagram with marked peak positions of the crystalline S,S-ethylenediamine-N,N‘-disuccinic acid form B according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 5: Fig. 5 shows an X-ray powder diffraction diagram of the crystalline S,S-ethylene- diamine-N,N‘-disuccinic acid form C according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 6: Fig. 6 shows an X-ray powder diffraction diagram with marked peak positions of the crystalline S,S-ethylenediamine-N,N‘-disuccinic acid form C according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 7: Fig. 7 shows an X-ray powder diffraction diagram of the crystalline S,S-ethylene- diamine-N,N‘-disuccinic acid form F according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 8: Fig. 8 shows an X-ray powder diffraction diagram with marked peak positions of the crystalline S,S-ethylenediamine-N,N‘-disuccinic acid form F according to the present invention, measured at 25 °C and using Cu Ka-radiation.Fig. 9: Fig. 9 shows a thermogravimetric analysis (TGA) diagram of the crystalline S,S- ethylenediamine-N,N‘-disuccinic acid form B according to the present invention, measured at a heating rate of 10 °C / min.Fig. 10: Fig. 10 shows a thermogravimetric analysis (TGA) diagram of the crystalline S,S- ethylenediamine-N,N‘-disuccinic acid form C according to the present invention, measured at a heating rate of 10 °C / min.Fig. 11 : Fig. 11 shows a thermogravimetric analysis (TGA) diagram of the crystalline S,S- ethylenediamine-N,N‘-disuccinic acid form F according to the present invention, measured at a heating rate of 10 °C / min.Brief description of sequences:SEQ ID NO.: 1 to 2 are the amino acid sequences of an EDDS synthase from Chelatococ- cus asaccharovorans and Chelatovirans sp. BNC1 respectively, (as is further described here below). SEQ ID NO.: 15 and 16 are the corresponding nucleic acid sequences.SEQ ID NO.: 3 to 14 and SEQ ID NO. 29 to 38 are amino acid sequences of EDDS synthase variants. SEQ ID NO.: 21 to 28 and 39 to 48 are the corresponding nucleic acid sequences.The following examples are meant to further explain and illustrate the present invention without limiting its scope.The DNA sequence encoding the EDDS synthase (SEQ ID NO.:1 or SEQ ID NO.: 2) was generated using standard codon usage of Escherichia coli. The DNA sequences according to SEQ ID NOs.: 15 and 16 were synthesized (BioCat GmbH) and cloned into the plasmid pDHE19.2 (Ress-Loeschke, M. et al., DE 19848129, 1998, (BASF AG)). The gene of interest lies under control of a rhamnose inducible promoter (rhaBAD). The resulting plasmids were used to transform competent cells (Chung, C.T. et al., Proc Natl Acad Sci U S A, 1989, 86, 2172) of the E. coli strain TG10, pAgro, pHSG575 (E. coli TG10 (Kesseler, M. et al., W02004050877A1 , 2004, (BASF AG)). The strain is a rhaA- derivate of E. coli TG (DSMZ 6056) transformed with pHSG575 (Takeshita, S. et al., Gene, 1987, 61 , 63) and pAgro4 (pBB541 in Tomoyasu, T. et al., Mol. Microbiol., 2001 , 40, 397).All EDDS synthases disclosed herein are suited and can be used for preparing, in a bio- catalytic reaction, S,S-EDDS. S.S-EDDS is preferably received from such biocatalytic processes in its solid (crystalline) form A, or in a mixture of its solid (crystalline) forms A and B, as described herein. Without wishing to be bound by theory, it is assumed that the conditions (temperature, time, vacuum) under which S.S-EDDS as received from said biocatalytic processes is dried has an impact on the exact product (usually crystalline forms A of S.S-EDDS, or a mixture of crystalline forms A and B, respectively) received from said biocatalytic processes.E. coli strains producing an EDDS synthase having an amino acid sequence according to SEQ ID NO.:1 or SEQ ID NO.: 2 as obtained in example 1 were cultivated in a small-scale stirred fermentation system. To generate material for inoculation, a seed train consisting of two steps using shake flasks was performed. In a first pre-culture, a 250 mL shake flask filled with 25 mL LB medium was cultivated for 8 hrs, whereas in the second pre-culture a 1 L shake flask with 100 mL defined mineral salt medium was used. After 16 hrs, cultivation was stopped and a small portion of the second pre-culture was used to inoculate the main culture.The main culture fermentation process was a fed-batch process using a defined mineral salt medium. A carbon-vitamin-salt mixture was added using a defined feed profile during cultivation. The pH was controlled via addition of NH4(OH) and EDDS synthase production was induced by adding a rhamnose-IPTG (0,5 g / L rhamnose and 0.1 mM IPTG) solution at an oxygen transfer rate of 50 mM / h. Dissolved oxygen was actively controlled via stirrer speed and aeration to avoid oxygen limited conditions. After 48 hrs, fermentation was stopped and the whole cell biocatalyst was harvested.Example 3: Spray-drying of the biocatalystFor concentration and for improving the storage stability of the whole cell biocatalyst, the material obtained after fermentation (see example 2 above) was further processed. During the biocatalyst processing, cell disruption of the whole cell biocatalyst was applied.The whole cell biocatalyst in culture medium was spray-dried with a 2-flu id-nozzle spray dryer (Biichi) at an inlet temperature of 80 °C and an outlet temperature of 42-44 °C. The spray-drying conditions applied are shown in table 1 below: Table 1 : Spray-drying conditions of whole cell biocatalyst in culture mediumExample 4: Synthesis of S.S-EDDSAfter cell harvest and downstream processing, the biocatalyst was used for S,S-EDDS synthesis. Biocatalyst material comprising the S,S-EDDS synthase according to SEQ ID NO.: 1 was applied.Fumaric acid (9.54 g), magnesium hydroxide (3.56 g) and ethylenediamine (2.50 g) were added to water (63.5 mL) with vigorous stirring and heated to 50 °C for 10 min. and then allowed to cool to 40 °C. The pH of the resulting solution was adjusted to 8.5 with NaOH (25 % w / w in water) and then 209.6 mg of the biocatalyst, which was spray-dried (for prep- aration see example 3 above), was added (200 mg cell dry weight, prepared as described above).The reaction mixture was stirred for 5 hrs at 40 °C. During this time, the pH was adjusted to 8.5 using NaOH (25 % w / w in water). After 5 hrs, HPLC analysis showed a concentration of 432 mM EDDS, 49 mM malic acid and 37 mM fumaric acid. Table 2: Amounts of substrate (fumaric acid), by-product (malic acid) and product (S,S- EDDS) overtime in the synthesis of S,S-EDDS with a biocatalyst mixture processed by spray-dryingTurnover after 300 min: 87%Reaction velocity: 3.53 mM / minSpecific activity: 1 .43 kU / g2705.8 g water were placed in a 4 L miniplant reactor with propeller stirrer (300 U / min), thermostat, IT-thermometer, pH probe, cooling device and dropping funnel. 406.3 g fumaric acid and 112.3 g Mg(OH)2 were added. Subsequently, 106.4 g ethylenediamine were added over 3 min. The pH value of the mixture so received was adjusted with 28.55 mL aqueous NaOH solution (25 % w / w in water) to pH 8.49. To this receiving mixture, 8.86 g of spray-dried biocatalyst (EDDS synthase, for preparation see example 3 above) were added as aqueous suspension. The resulting mixture was stirred at 40 °C for 26.5 hrs. The pH value was continuously monitored and adjusted to about pH 8.5 by addition of aqueous NaOH (25% w / w in water) as necessary.For separation of the biocatalyst, 17.72 g Celite 503 were added and the resulting mixture was brought to and held at 80 °C for 1 h. Then, the resulting suspension was filtered (G4) and dried in vacuum. The filtrate was heated to 40 °C and the pH value was adjusted to pH 3.3 by addition of 47 % sulfuric acid (680 g). The resulting solution was heated to 60 °C, stirred for 1 h and then cooled overnight to 20 °C.The resulting precipitate was filtered (pore size 1) and washed three times with 875 mL water each time. The wet solid material was dried overnight at 80 °C and 30 mbar (30 hPa) to constant weight. 478.34 g of S,S-EDDS form B, was obtained. The respective PXRD diagram is shown in Fig. 3 and discussed above2705.8 g water were placed in a 4 L miniplant reactor with propeller stirrer (300 U / min), thermostat, IT-thermometer, pH probe, cooling device and dropping funnel. 406.3 g fumaric acid and 151 .7 g Mg(OH)2 were added. Subsequently, 106.4 g ethylenediamin were added over 3 min. The pH value of the mixture so received was adjusted with 28.55 mL aqueous NaOH solution (25 % w / w in water) to pH 8.49. To this receiving mixture, 8.86 g of spray- dried biocatalyst (EDDS synthase, for preparation see example 3 above) were added as aqueous suspension. The resulting mixture was stirred at 40°C for 26.5 h. The pH valuewas continuously monitored and adjusted to about pH 8.5 by addition of aqueous NaOH (25 % w / w in water) as necessary.For separation of the biocatalyst, 17.72 g Celite 503 were added and the resulting mixture was brought to and held at 80 °C for 1 h. Then, the resulting suspension was filtered (G4) and dried in vacuum. The filtrate was heated to 40 °C and the pH value was adjusted to pH 3.3 by addition of 47 % sulfuric acid (680 g). The resulting solution was heated to 60°C stirred for 1 h and then cooled over night to 20°C.The resulting precipitate was filtered (pore size 1) and three times washed with 875 mL water each time. The wet solid material was dried over night at 60 °C and 30 mbar (30 hPa) to constant weight. 531.12 g SS-EDDS (mixture of A and B form) was obtained.10 g solid S,S-EDDS (mixture of forms A and B, for preparation see example 6 above) was suspended in 50 mL deionized water and stirred for 3 days. The solid material received was filtered and dried at room temperature to yield S,S-EDDS, form A. The respective PXRD diagram is shown in Fig. 1 and discussed above.Wet preparation of S,S-EDDS, form C10 g solid S,S-EDDS (mixture of forms A and B, for preparation see example 6 above) was suspended in 100 mL ethanol. The resulting suspension was heated to reflux and stirred for 3.5 hrs. Thereafter, the suspension was cooled to 50 °C, filtered and the solid filtration residue was dried in vacuum (30 mbar I 30 hPa) at room temperature to yield S,S-EDDS, form C.8.2 Dry preparation of S,S-EDDS, form CApproximately 50 mg solid S,S-EDDS (mixture of forms A and B, for preparation see example 6 above) was brought to and held at 150 °C for 15 min. S,S-EDDS, form C was received. The respective PXRD diagram is shown in Fig. 5 and discussed above.11 g solid S.S-EDDS (mixture of forms A and B, for preparation see example 6 above) was suspended in 65 mL 1 ,4-dioxane. The resulting suspension was stirred at 70 °C for 3 hrs and then cooled to room temperature, followed by further heating to 80 °C and stirring for 2 hrs. Thereafter, the suspension was cooled again to room temperature. Afterwards, the suspension was consecutively heated three times to reflux and stirred for 7 hours, each time followed by cooling to room temperature.The resulting suspension was filtered, washed with 1 ,4-dioxane and dried in vacuum (30 mbar / 30 hPa) at room temperature overnight, to yield S.S-EDDS, form F. The respective PXRD diagram is shown in Fig. 7 and discussed above.of solid forms of S.S-EDDSPowder X-Ray Diffraction (“PXRD”) diagrams were recorded with a PANalytical X'Pert Pro X-ray diffractometer using Cu Ka-radiation in reflection geometry (Bragg-Brentano). Each sample was placed in a silicon single crystal sample holder of 0.2 mm depth and gently and precisely flattened. The tube voltage was 45 kV and current was 40 mA. The PXRD data were collected at room temperature (25 °C) in the range from 20 = 3.0°-40.0° with increments of 0.017° and measurement times of 20 to 200 s / step.diagram of S.S-EDDS, form BThe powder X-ray diffraction diagram of S.S-EDDS, form B (for preparation see example 5 above) at 25 °C and using Cu Ka-radiation displayed the following reflections, quoted as 20-values in °: 10.7 ± 0.2; 13.2 ± 0.2; 15.7 ± 0.2; 16.1 ± 0.2; 16.8 ± 0.2; 17.4 ± 0.2; 18.2 ±0.2; 19.4 ± 0.2; 20.9 ± 0.2: 21 .4 ± 0.2; 22.6 ± 0.2; 24.3 ± 0.2; 25.7 ± 0.2; 26.1 ± 0.2; 26.9 ±0.2; 28.0 ± 0.2; 28.7 ± 0.2; 30.2 ± 0.2; 30.9 ± 0.2; 31 .7 ± 0.2; 32.4 ± 0.2; 33.1 ± 0.2; 34.5 ±0.2; 35.7 ± 0.2; 36.4 ± 0.2; 37.8 ± 0.2; 38.5 ± 0.2.Figures 3 and 4 each show a powder X-ray diffraction diagram of S.S-EDDS, form B.diagram of S.S-EDDS, form CThe powder X-ray diffraction diagram of S.S-EDDS, form C (for preparation see example8.2 above) at 25 °C and using Cu Ka-radiation displayed the following reflections, quotedas 20-values in °: 9.1 ± 0.2; 16.4 ± 0.2; 18.2 ± 0.2; 19.0 ± 0.2; 20.3 ± 0.2; 24.4 ± 0.2; 24.9± 0.2; 25.8 ± 0.2; 27.6 ± 0.2; 30.7 ± 0.2; 31 .9 ± 0.2; 33.3 ± 0.2; 37.9 ± 0.2; 38.5 ± 0.2.Figures 5 and 6 each show a powder X-ray diffraction diagram of S.S-EDDS, form C.10.3 PXRD diagram of S.S-EDDS, form FThe powder X-ray diffraction diagram of S.S-EDDS, form F (for preparation see example 9 above) at 25 °C and using Cu Ka-radiation displayed the following reflections, quoted as 20-values in °: 9.1 ± 0.2; 13.9 ± 0.2; 16.4 ± 0.2; 18.2 ± 0.2; 18.9 ± 0.2; 19.3 ± 0.2; 19.6 ±0.2; 19.9 ± 0.2; 20.3 ± 0.2; 20.9 ± 0.2; 21 .6 ± 0.2; 21 .8 ± 0.2; 22.5 ± 0.2; 23.5 ± 0.2; 24.2 ±0.2; 24.9 ± 0.2; 25.8 ± 0.2; 26.3 ± 0.2; 28.1 ± 0.2; 29.0 ± 0.2; 30.9 ± 0.2; 31 .6 ± 0.2; 32.1 ±0.2; 33.3 ± 0.2; 33.9 ± 0.2; 35.1 ± 0.2; 36.1 ± 0.2; 36.8 ± 0.2; 38.1 ± 0.2; 39.1 ± 0.2; 39.1 ±0.2.Figures 7 and 8 each show a powder X-ray diffraction diagram of S.S-EDDS, form F.of solid forms of S.S-EDDSThermogravimetric analyses (TGA) data were recorded with a TG / DTA 7200 (Sil Nano Technology Inc). The samples were placed in platinum standard pans. The sample size in each case was 2 to 10 mg. The heating rate was 10 °C / min. The samples were purged with a stream of synthetic air during the experiment.Thermogravimetric analysis of S.S-EDDS, form AA TGA diagram of S.S-EDDS, form A shows that weight loss already begins at room temperature, which makes form A an unstable solid form of S.S-EDDS. Up to 98 °C, the weight loss of 13.6 wt.-% can be attributed to the loss of approximately 3 mol water (14.3 wt%). Between 98 and 154 °C, a further weight loss of 8.9 wt.-% can be observed, which corresponds to further loss of approximately two mol water (9.5 wt.-%). Decomposition begins at above 170 °C.1 1.2 Thermogravimetric analysis of S.S-EDDS, form BFigure 9 shows a TGA diagram of S.S-EDDS, form B. Between 77 °C and 152 °C, a weight loss of about 1 1 wt.-% was observed, corresponding to a loss of 2 molecules of water permolecule of S,S-EDDS. It can further be seen from figure 9 that decomposition of this form begins at above 177 °C.1 1.3 Thermogravimetric analysis of S.S-EDDS, form CFigure 10 shows a TGA diagram of S.S-EDDS, form C. It can be seen from figure 10 that decomposition of this form begins above 160°C (weight change in TGA experiment > 0.2 wt-% occurred at 162°C). No significant weight loss can be observed up to the beginning of decomposition.Thermogravimetric analysis of S.S-EDDS, form FFigure 11 shows a TGA diagram of S.S-EDDS, form F. It can be seen from figure 1 1 that decomposition of this form begins at above 170 °C (weight change in TGA experiment occurred at > 0.2 wt-% at 179°C). No significant weight loss can be observed up to the beginning of decomposition.of solid forms of S.S-EDDSApproximately 5 g of each sample of solid S.S-EDDS forms were exposed for 72 hrs to an atmosphere of 70 % relative humidity at 35 °C and the weight of the sample was determined before and after this treatment. The weight differences were noted as percentage relative to the weight of the sample before treatment and are reported here below:Hygroscopicity of S.S-EDDS, form BS.S-EDDS form B was found to be slightly hygroscopic (5.3 % weight gain).12.2 Hygroscopicity of S.S-EDDS, form CS.S-EDDS form C was found to be not hygroscopic (0.02 % weight loss).Hygroscopicity of S.S-EDDS, form FS.S-EDDS form F was found to be not hygroscopic (0.2 % weight gain).

Claims

Claims:

1. Crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid, selected from the group consisting of:- crystalline form B, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, or all of the following reflections, quoted as 20-values in °: 10.7 ± 0.2, 13.2 ± 0.2, 15.7 ± 0.2 and 19.4 ± 0.2;- crystalline form C, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, at least four, or all of the following reflections, quoted as 20-values in °: 9.1 ± 0.2, 18.2 ± 0.2, 19.0 ± 0.2, 20.3 ± 0.2 and 31.9 ± 0.2; and- crystalline form F, which in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation displays at least three, at least four, at least five, or all of the following reflections, quoted as 20-values in °: 9.1 ± 0.2, 13.9 ± 0.2, 19.3 ± 0.2, 20.9 ± 0.2, 21 .6 ± 0.2 and 35.1 ± 0.2.

2. Crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid, as defined in claim 1 , wherein preferably said crystalline form B displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values in °: 24.3 ± 0.2, 25.7 ± 0.2, 26.1 ± 0.2, 28.0 ± 0.2 and 30.9 ± 0.2.

3. Crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid, as defined in claim 1 , wherein preferably said crystalline form C displays in an X-ray powder diffraction diagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values in °: 24.4 ± 0.2, 24.9 ± 0.2, 25.8 ± 0.2, 30.7 ± 0.2 and 33.3 ± 0.2.

4. Crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid, as defined in claim 1 , wherein preferably said crystalline form F displays in an X-ray powder diffractiondiagram at 25 °C and using Cu Ka-radiation one, more than one, or all of the following further reflections, quoted as 20-values in °: 21.8 ± 0.2, 25.8 ± 0.2, 30.9 ± 0.2 and 33.9 ± 0.2.

5. Crystalline form B of S,S-ethylenediamine-N,N‘-disuccinic acid according to anyone of claims 1 or 2, wherein said form B is a dihydrate.

6. Crystalline form C of S,S-ethylenediamine-N,N‘-disuccinic acid according to anyone of claims 1 or 3, wherein said form C is an anhydrate.

7. Crystalline form F of S,S-ethylenediamine-N,N‘-disuccinic acid according to anyone of claims 1 or 4, wherein said form F is an anhydrate.

8. Composition, preferably selected from the group consisting of cleaning composition, detergent composition, preferably water softener and / or water deionizer, and cosmetic composition, comprising at least one crystalline form of S,S-ethylenediamine- N,N‘-disuccinic acid selected from the group consisting of crystalline form B as defined in anyone of claims 1 or 2, crystalline form C as defined in anyone of claims 1 or 3 and crystalline form F as defined in anyone of claims 1 or 4.

9. Use of a crystalline form of S,S-ethylenediamine-N,N‘-disuccinic acid selected from the group consisting of crystalline form B, crystalline form C and crystalline form F according to anyone of claims 1 to 7, as a stabilizing agent or complexing agent in cleaning compositions, detergent compositions and / or cosmetic compositions, or for the production of cleaning compositions, detergent compositions and / or cosmetic compositions.

10. Method of making and / or isolating solid form B of S,S-ethylenediamine-N,N‘-disuc- cinic acid, comprising the steps:51) providing or preparing solid form A of S.S-EDDS, or a mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates; and52) subjecting the solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, as provided orprepared in step S1), to reduced pressure of < 30 hPa and to a temperature in the range of from > 60 to < 90 °C, to constant weight; preferably to receive solid form B of S.S-EDDS, or to receive a mixture that comprises a higher proportion of solid form B of S.S-EDDS than an initial mixture as provided or prepared in step S1).11 . Method according to claim 10, wherein in step S1) the solid form A of S.S-EDDS or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates is provided resulting from a biocatalytic production process or prepared by a biocatalytic production process; and / or in step S2) the solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, as provided or prepared in step S1), is subjected to reduced pressure in the range of from > 10 hPa to < 30 hPa and to a temperature in the range of from > 60 to < 85 °C, preferably in the range of from > 65 to < 82 °C, to constant weight.

12. Method of making and / or isolating solid form C of S,S-ethylenediamine-N,N‘-disuc- cinic acid, comprising the steps:51) providing or preparing solid form A of S.S-EDDS, or a mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates; and52) subjecting the solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, as provided or prepared in step S1), to a temperature in the range of from > 120 to < 165 °C, preferably to constant weight; preferably to receive solid form C of S.S-EDDS.

13. Method according to claim 12, wherein in step S1) the solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, is provided resulting from a biocatalytic production process or prepared by a biocatalytic production process; and / or in step S2) the solid form A of S.S-EDDS, or the mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, as provided or prepared in step S1), is subjected to a temperature in the range of from > 130 to < 160 °C, preferably in the range of from > 135 to < 155 °C, preferably to constant weight.

14. Method of making and / or isolating solid form F of S,S-ethylenediamine-N,N‘-disuc- cinic acid, by recrystallizing solid form A of S.S-EDDS, or a mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, in an organic solvent, preferably until completion of re-crystallization; and / or wherein the method comprises the steps:51) providing or preparing solid form A of S.S-EDDS, or a mixture comprising solid form A of S.S-EDDS and other solid forms of S.S-EDDS hydrates, in an organic solvent, to receive a solution or suspension; and52) subjecting the solution or suspension as received in step S1) to a temperature in the range of from > 65 to < 130 °C once or more than once, preferably with intermittent cooling to room temperature; preferablyuntil solid form F of S,S-ethylenediamine-N,N‘-disuccinic acid has formed, preferably as determined by powder X-ray diffraction; and / or for a duration in the range of from > 1 hour < 24 hours each time; preferably to receive solid form F of S,S-EDDS.

15. Method according to claim 14, wherein the solid form A of S.S-EDDS or the mixture comprising solid form A of S,S-EDDS and other solid forms of S.S-EDDS hydrates, preferably as provided or prepared in step S1), is provided resulting from a biocatalytic production process or prepared by a biocatalytic production process; and / or wherein in step S2) the solution or suspension as received in step S1) is subjected to a temperature in the range of from > 65 to < 120 °C, preferably in the range of from > 65 to < 110 °C, several times, preferably with intermittent cooling to room temperature preferably until solid (crystalline) form F of S,S-ethylenediamine-N,N‘-disuccinic acid has formed, preferably as determined by powder X-ray diffraction; and / or for a duration in the range of from > 90 minutes < 18 hours each time; and / orwherein the organic solvent, preferably the organic solvent in step S1), is a dipolar aprotic solvent, preferably selected from the group consisting of 1 ,4-diox- ane, dimethyl formamide, dimethylsulfoxide and mixtures thereof, more preferably the organic solvent in step S1) comprises or is 1 ,4-dioxane, preferably 1 ,4-dioxane with a water content of < 5 mass-%; and / or further comprising the stepS3) isolating any precipitate received from step S2), preferably by filtration, and subjecting the isolated precipitate to reduced pressure of < 30 hPa and a temperature in the range of from > 15 to < 90 °C, preferably of from > 15 to < 60 °C, more preferably of from > 15 to < 40 °C, preferably to constant weight, preferably for a duration in the range of from > 4 to < 24 hours, more preferably of from > 6 to < 12 hours.

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