Sodium methyl glycine-N,N-diacetic acid compound, process to prepare it and use thereof

Patent metadata

Field	Value
Publication number	US-10829719-B2
Application number	US-201816629214-A
Country	US
Kind code	B2
Filing date	Jul 3, 2018
Priority date	Jul 7, 2017
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A solid composition, methods for preparing and using the composition, and a rehydrated crystal are disclosed. An exemplary solid composition contains at least about 2 wt % of methyl glycine-N,N-diacetic acid trisodium salt of crystal type III, based on the total weight of crystalline methyl glycine-N,N-diacetic acid trisodium salt compounds, wherein the crystal type III is the form of a crystal, comprising a crystalline modification characterized by the reflections enlisted below when analyzed with X-ray diffraction analysis using Cu Kα radiation:

Type III

2Θ
d (Å)

5.8
15.2

7.5
11.8

8.1
10.9

9.5
9.3

11.7
7.6

13.9
6.4

15.1
5.9

16.5
5.4

17.3
5.1

18.5
4.8

19.1
4.65

20.1
4.4.

First claim

The invention claimed is:

1. A solid composition containing at least about 2 wt % of methyl glycine-N,N-diacetic acid trisodium salt of crystal type III, based on the total weight of crystalline methyl glycine-N,N-diacetic acid trisodium salt compounds, wherein the crystal type III is the form of a crystal, comprising a crystalline modification characterized by the reflections enlisted below when analyzed with X-ray diffraction analysis using Cu Kα radiation:

Type III

2Θ
d (Å)

5.8
15.2

7.5
11.8

8.1
10.9

9.5
9.3

11.7
7.6

13.9
6.4

15.1
5.9

16.5
5.4

17.3
5.1

18.5
4.8

19.1
4.65

20.1
4.4.

2. The composition containing methyl glycine-N,N-diacetic acid trisodium salt in the form of the crystal type III modification of claim 1 and less than 20 wt % of methyl glycine-N,N-diacetic acid trisodium salt in another crystalline modification, based on the total weight of methyl glycine-N,N-diacetic acid trisodium salt crystalline compounds in the composition.

3. The composition of claim 2 wherein the composition has a degree of crystallinity of higher than 10%.

4. The composition of claim 2 further comprising a compound selected from the group of a chelating agent, a builder, a surfactant, a descaling agent, and an anti-corrosion agent.

5. A method for preparing the composition containing methyl glycine-N,N-diacetic acid trisodium salt of the crystal type III of claim 1 , the method comprising:
subjecting a composition containing methyl glycine-N,N-diacetic acid trisodium salt with a crystalline modification characterized by the type I reflections listed below when analyzed with X-ray diffraction analysis using Cu Kα radiation to a heat treatment at a temperature of between about 75 and about 200° C., a low pressure treatment at a pressure that is between 0 and 1 bar, or to both a heat treatment and a low pressure treatment simultaneously or one after the other

type I

2Θ
d (Å)

8.2
10.8

10.5
8.4

15.6
5.7

16.5
5.4

17.1
5.2

18.1
4.9

18.8
4.7

21
4.25

21.4
4.15

22.6
3.9

23.7
3.75

24.7
3.6.

6. The method of claim 5 wherein the heat treatment and/or low pressure treatment is performed for a period between 1 minute and 24 hours.

7. A method for converting the methyl glycine-N,N-diacetic acid trisodium salt of crystal type III of claim 1 into a methyl glycine-N,N-diacetic acid trisodium salt with a crystalline modification of hydrated crystal type I wherein hydrated crystal type I is characterized by the reflections listed below when analyzed with X-ray diffraction analysis using Cu Kα radiation:

type I

2Θ
d (Å)

8.2
10.8

10.5
8.4

15.6
5.7

16.5
5.4

17.1
5.2

18.1
4.9

18.8
4.7

21
4.25

21.4
4.15

22.6
3.9

23.7
3.75

24.7
3.6

Assignees

• Nouryon Chemicals Int Bv

Inventors

• Schomaker Elwin
• Van Haeren Paulus Johannes Cornelis
• Heus Martin
• Doppen Roy Gérard

Classifications

• C07C227/42 Primary

  Crystallisation · CPC title

• C07C229/16

  to carbon atoms of hydrocarbon radicals substituted by amino or carboxyl groups, e.g. ethylenediamine-tetra-acetic acid, iminodiacetic acids · CPC title

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• C11D3/33 Primary

  Amino carboxylic acids · CPC title