I was under the impression he had asked for captaincy to sign the new contract. I thought i had read it somewhere. I am probably wrong. My bad then.
Edit: It took me a bit time but i found it. According to a report from Di Marzio in June of 2014, Juventus were offering more to Rano than Inter. So he asked for the captain's armband as well to accept our lower offer instead of Juve's. Ieven found reports saying that our directors almost forced Mazzarri to give him the captaincy. Here's GDM report as i found it on SempreInter:
Sky: Inter ahead for Ranocchia but offer less than Juventus
Gianluca Di Marzio of “Sky” has given some insight on the Ranocchia-Inter contract saga. The journalist outlined that Antonio Conte is pressing to have the player at Juve next season. However, the player seems to be keen on remaining at Inter next season, despite Inter offering him less money. His terms are that he receives consideration from the club related to the captain’s armband for next season, which he would appreciate.
Source: FCInterNews.it