	US 11,851,528 B2
	Process for preparing a polyamide, a nylon salt to be used therein and a process for making the salt
Bas Van Laarhoven, Echt (NL); Christiaan Johannes Cornelis Stoelwinder, Echt (NL); and Mark Helmsing, Echt (NL)
Assigned to DSM IP ASSETS B.V., Heerlen (NL)
Filed by DSM IP ASSETS B.V., Heerlen (NL)
Filed on Oct. 28, 2021, as Appl. No. 17/513,665.
Application 17/513,665 is a division of application No. 16/778,822, filed on Jan. 31, 2020, granted, now 11,299,589.
Application 16/778,822 is a division of application No. 15/329,270, granted, now 10,584,206, previously published as PCT/EP2015/073639, filed on Jul. 29, 2015.
Claims priority of application No. 14178927 (EP), filed on Jul. 29, 2014.
Prior Publication US 2022/0098368 A1, Mar. 31, 2022
Int. Cl. C08G 69/30 (2006.01); C08G 69/26 (2006.01); C08G 69/28 (2006.01); B01J 2/04 (2006.01); C07C 51/41 (2006.01); C07C 209/68 (2006.01); C08J 3/12 (2006.01)

CPC C08G 69/30 (2013.01) [B01J 2/04 (2013.01); C07C 51/412 (2013.01); C07C 209/68 (2013.01); C08G 69/26 (2013.01); C08G 69/265 (2013.01); C08G 69/28 (2013.01); C08J 3/12 (2013.01); C08J 2377/06 (2013.01)]

8 Claims

1. A process for preparing a polyamide comprising conducting direct solid state polymerization (DSSP) of a diammonium dicarboxylate salt, wherein

the diammonium dicarboxylate salt is a granulate salt material prepared by fluidized bed spray granulation of an aqueous solution or slurry comprising diammonium dicarboxylate salt dissolved or dispersed in an aqueous medium, and wherein

the diammonium dicarboxylate salt has the following physical properties:

(a) a particle size distribution with a median particle size (d50) in the range of 200-1000 μm, measured by laser granulometry with the method according to ISO 13320-1 at 20° C., and

(b) a tapped bulk density in the range of 350-750 kg/m³, measured by the method according to ASTM D6393.