Patent ID: 7754097

Claim:
A coolant concentrate having improved storage stability, the concentrate consisting of: at least 90 wt % freezing point depressant, based on the total weight of the coolant concentrate; at least one phosphate or the alkali metal or alkaline earth metal salt thereof, a nitrite, and one or more corrosion inhibitors selected from the group consisting of organic acids; azole type compounds; nitrates; borates; benzoates; molybdates, and alkali metal or alkaline earth metal salts thereof; at least one stabilizer selected from the group consisting of polyacrylate polymers of the formula: where R 1 is H; R 4 is a terminating group; X is and R 2 and R 3 are each independently hydrogen, an alkali metal or an alkaline earth metal, and the sum of m and n provide a number average equivalent weight of less than 6500, and optionally at least one additive selected from the group consisting of water, antifoam agents, lubricants, colorants, dispersants, anti-scaling agents, wetting agents, surfactants, pH adjusting and buffering agents.