Chat Bans are exactly what they sound like – a way to remove a player's ability to use the chat while playing a match. According to Psyonix, the conduct that qualifies you for a Chat Ban is the same type of behavior that can land you a Game Ban. The game's Language Ban system that is used to find racial, gender, and homophobic slurs, as well as other inappropriate language, will be used by the Chat Ban system to locate instances of infringement.
It's important to note that not only do Chat Bans affect your ability to Rocket League Keys type messages, but will affect your ability to utilize Quick Chat as well. Affected players will only be able to use Quick Chat functions every five seconds. It's also important to note that the bans will not extend to Private Matches.
When a Chat Ban is levied against your account, you'll receive an in-game notification that will tell you how long you have been banned for. Further, you will be notified with a pop-up in the main menu if a report you filed against another player led to any action. In this feedback, the player's name will not be provided.