Polyisobutylene-based compositions for golf balls

A golf ball, comprising:

• a core;
• a polyurea intermediate casing layer produced by a reaction of ingredients comprising an isocyanate, amine-terminated polyisobutylene, and amine-terminated cross-linking agent;
• and
• a polymeric cover material, wherein the cover material comprises a thermoplastic or thermoset material and does not include a polyurea formed by reacting an isocyanate, amine-terminated polyisobutylene, and amine-terminated cross-linking agent.

A golf ball, comprising:

• a core;
• a polymeric intermediate layer, wherein the intermediate layer comprises a thermoplastic or thermoset material and does not include a polyurea formed by reacting an isocyanate, amine-terminated polyisobutylene, and amine-terminated cross-linking agent;
• and
• a polyurea cover material produced by a reaction of ingredients comprising an isocyanate, amine-terminated polyisobutylene, and amine-terminated cross-linking agent.