The present invention is directed to non-flammable materials such as thermal insulation, thermal barriers, which include but not limited to foam, panels, sheets, and methods of making these non-flammable materials from water-soluble alkali metal silicates and fillers.
Thermal insulation is known for use in houses, buildings, pipes, ductwork, and many other applications. The best-known thermal insulation is fiberglass insulation, sold commercially by, for example, Owens Corning (Toledo, Ohio) and Johns Manville. Although this thermal insulation is very popular, it possesses a relatively low “R” value and reduced thermal insulating properties as it absorbs moisture.
There are several different types of petroleum-based foam such as polyurethane and polystyrene. Polyurethane and other petroleum-based foams have been used for many years and have substantially better R-value as compared to fiberglass insulation. However, petroleum-based foams have several disadvantages. First, they are flammable and can give off toxic fumes if burned. Second, since they are made from petroleum products, such materials are generally bad for the environment if they are not disposed of properly.
U.S. Pat. No. 5,035,951 relates to coatings useful for protecting materials against the effects of overheating. More particularly, the patent relates to intumescent coatings which, when exposed to flame temperatures, provide heat absorptive and insulative thermal barriers. The patent discloses an aqueous mixture of a water-soluble alkali metal silicate, a hydrated metal silicate clay, and an inorganic particulate material which, when exposed to flame temperatures, endothermically releases a nonflammable gas. The sodium and potassium silicates utilized in this coating have softening points of 1200 and 1280° F., and flow points of 1545 and 1660° F., respectively. This composition utilizes clay and other materials that give the composition the ability to withstand temperatures up to 3200-3400° F.
There is a need for foam insulation that possesses a high “R” value and which is nontoxic, nonflammable, and that is not detrimental to the environment. The present invention is believed to be an answer to that need.
U.S. Pat. No. 7,744,783 describes methods of preparing a non-flammable thermal insulation foam, comprising the steps of (a) providing a mixture comprising (1) at least one water-soluble alkali metal silicate, (2) at least one filler, and (3) at least one inorganic material which releases non-flammable gases when exposed to heat; and (b) applying the mixture to a support or mold; and (c) heating the mixture to form the non-flammable thermal insulation foam.
From the above, it is therefore seen that there exists a need in the art to overcome the deficiencies and limitations described herein and above.