Trimonium..." means a quaternary trimethylammonium salt, "hydrolyzed soy protein" means hydrolyzed soy proteins.
Propyltrimonium hydrolyzed soy protein is used in cosmetic formulations. The mixture of substances acts as an antistatic agent (reduces static electricity by neutralizing the electrical charge on the surface, e.g. of hair) and as a combability aid (reduces or prevents tangling of the hair due to changes or damage on the hair surface and thus improves combability).