WO 2016/102591 PCT/EP2015/08UI31
-21 -
CLAIMS

10

1. Powder composition comprising particles, which particles comprise
at least 75 % by weight of an alkali metal bicarbonate,
less than 15 % by weight of an alkali metal carbonate,
less than 20 % by weight of water, and
0.02 to 10 % by weight of an amino acid or a salt thereof.
2. Powder composition according to claim 1, wherein the amino acid is an
a-amino acid, preferably with a hydrophobic side chain.

3. Powder composition according to claim 1 or 2, wherein the amino acid is
15 an a-amino acid according to formula (I)

20

or a salt thereof, wherein R is hydrogen, or an alkyl, or an optionally substituted aryl or an optionally substituted heteroaryl group, preferably a CI to C6 alkyl group.
4. Powder composition according to any one of the preceding claims, wherein the particles have a particle size distribution of D50 of at most 25 um.

25 5. Powder composition according to any one of the preceding claims,
wherein the particle size distribution of the particles show a span, which is defined by span = (D90 - Dio)/D5o, of lower than 1.8.

WO 2016/102591

PCT/EP2015/081031

-22-
6. Powder composition according to any one of the preceding claims, having an angle of repose of less than 60°, in particular between 15° and 30°.
5 7. Powder composition according to any one of the preceding claims,
having a bulk density of at least 300 kg/m3, preferably at least 400 kg/km3.
8. Process for preparing alkali metal bicarbonate particles by co-grinding of
10 the alkali metal bicarbonate in the presence of 0.02 to 10 parts by weight
of an amino acid, per 100 parts by weight of the substance undergoing milling.
9. Process for preparing alkali metal bicarbonate particles by spray-drying
15 of an aqueous solution comprising 1 to 10 % by weight of the alkali
metal bicarbonate and 1 to 10000 ppm of an amino acid or a salt thereof.
10. Process for preparing alkali metal bicarbonate particles according to
claims 8 or 9, wherein the amino acid is an a-amino acid, preferably with
20 a hydrophobic side chain.
11. Process for preparing alkali metal bicarbonate particles according to any
one of claims 8 to 10, wherein the amino acid is an a-amino acid
according to formula (I)
25
wherein R is hydrogen, or an alkyl, or an optionally substituted aryl or an optionally substituted heteroaryl group, preferably a CI to C6 alkyl group.

WO 2016/102591

PCT/EP2015/081031

-23-
12. Process for preparing alkali metal bicarbonate particles according to any one of claims 8 to 11, wherein the particles have a particle size distribution of D50 of at most 25 p.m.
5 13. Process for preparing alkali metal bicarbonate particles according to any
one of claims 8 to 12, the particle size distribution of the particles show a span, which is defined by span = (D90 - D10) ID50, of lower than 1.8.
14. Powder composition comprising particles comprising an alkali metal
10 bicarbonate, which particles are obtainable by a process according to any
one of claims 8 to 13.
15. Powder composition comprising particles comprising an alkali metal
bicarbonate according to claim 14, having an angle of repose of between
15 15° and 30° and/ or a bulk density of at least 300 kg/m3, preferably at
least 400 kg/km3.
16. Use of an amino acid as additive for reducing the angle of repose, and/or
for reducing the mean particle size, and/or increasing the bulk density
20 and/or increasing the dissolution time of alkali metal bicarbonate
particles.
17. Use according to claim 16, wherein the alkali metal bicarbonate particles
are obtained by a spray-drying process, in particular by a spray-drying
25 process according to claims 9 to 13.
18. Use of a powder composition according to any of claims 1 to 7, Hand
15 as a leaving agent for food, and as a foaming agent for polymers.