United States Patent No. 4,597,884 (“the ’884 patent”) issued on July 1, 1986 for ICE AND SNOW MELT and is expired.

There are many materials used to melt snow and ice such as calcium chloride, sodium chloride (rock salt), CMA (calcium-magnesium-acetate) and the material of the ’884 patent. Since ice and snow melting materials have a lower freezing point than water, these materials can be used to melt snow and ice. Further, snow and ice melting materials add traction to the road. These are attractive characteristics for certain cities that may be completely shut down without proper snow removal equipment on streets, bridges and sidewalks. Salt is commonly used to aid in melting ice and snow. However, salt is corrosive and accelerates the rusting of automobiles. In addition, using large amounts of salt on roads allows the salt to enter the environment in large quantities posing risks to fish, lake and stream ecosystems, plants, animals and birds.

The ’884 patent relates to a material for melting snow and ice. The ’884 patent is composed of two materials: 1) a solid melting material and 2) a liquid phase melting compound. Urea, a non-corrosive material, may be used as the solid melting material. Unfortunately, while urea has snow and ice melting characteristics, urea has a long melting activation time. The melting activation time is defined by the amount of time that lapses after application of a melting material to the ice or snow and before melting begins. Urea may be blown away by wind before melting the snow or ice. The ’884 patent discloses coating the solid urea with a liquid phase melting compound. The liquid phase melting compound has a short melting activation time making up for the deficiencies of the solid urea, while still having desirable non-corrosive characteristics.

Filed under: Dead Patents by lbarbin