Method of sealing interior mine surface with a fire retardant hydrophilic polyurethane foam and resulting product
AssigneeW. R. Grace & Co.
InventorsGlenn E. Fulmer, Robert M. Murch
Life of this patent
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Abstract
A fire-retarding polyurethane foam is applied to the interior surfaces of a mine such as mine shafts, entries and tunnels. The coating is applied by spraying a mixture of foam-forming ingredients including a hydrophilic polyoxyalkylene urethane prepolymer and a large amount of an aqueous slurry containing a phosphorous compound, alumina trihydrate and a char-forming material such as starch or wood cellulose. The foam coating acts as a protective sealant, and it can also be applied on other surfaces where insulation and fire retardancy are desired.
Claims22
A method of sealing the interior surface of a mine with a fire-retarding polyurethane foam comprising spraying one the exposed surfaces of the mine, under foam-forming conditions, a foam-forming mine sealant composition comprising
- a. hydrophilic polyoxyalkylene urethane prepolymer,
- b. water in an amount of at least 20 moles of water for every mole of NCO groups in the prepolymer, and
- c. at least a three part fire-retarding additive mixture comprising
- (1) a phosphorous fire-retardant compound,
- (2) alumina trihydrate carried in the water phase, and
- (3) a water-dispersible and combustible organic carbon compound having from 0.1 to 1.0 hydroxyl group for every carbon atom present in said carbon compound, said carbon compound being carried in the water phase and being present from about 5 to about 30 parts by weight based on 100 parts by weight of the prepolymer, provided that when said carbon compound is wood cellulose it is present from about 2 to about 10 parts by weight of the prepolymer, and said carbon compound not functioning as a gelatinizing agent at the concentration employed.
A fire-retarding coated mine interior comprising a mine interior surface having deposited thereon a fire-retarding polyurethane foam mine sealant prepared by
- a. mixing a foam-forming mine sealant composition comprising
- (1) hydrophilic polyoxyalkylene urethane prepolymer,
- (2) water in an amount of at least 20 moles of water for every mole of NCO groups in the prepolymer, and
- (3) at least a three-part fire-retarding additive mixture comprising
- (i) a phosphorous fire-retardant compound,
- (ii) alumina trihydrate carried in the water phase, and
- (iii) a water-dispersible and combustible organic carbon compound having from 0.1 to 1.0 hydroxyl group for every carbon atom present in said carbon compound, said carbon compound being carried in the water phase and being present from about 5 to about 30 parts by weight based on 100 parts by weight of the prepolymer, provided that when said carbon compound is wood cellulose it is present from about 2 to about 10 parts by weight of the prepolymer, and said carbon compound not functioning as a gelatinizing agent at the concentration employed, and
- b. spraying the mixture onto the mine interior surface.
A fire-retarding and insulating member comprising a substrate having coated thereon a fire-retarding polyurethane foam prepared by
- a. mixing a foam-forming composition comprising
- (1) hydrophilic polyoxyalkylene urethane prepolymer,
- (2) water in an amount of at least 20 moles of water for every mole of NCO groups in the prepolymer, and
- (3) at least a three-part fire-retarding additive mixture comprising
- (i) a phosphorous fire-retardant compound,
- (ii) alumina trihydrate carried in the water phase, and
- (iii) a water-dispersible and combustible organic carbon compound having from 0.1 to 1.0 hydroxyl group for every carbon atom present in said carbon compound, said carbon compound being carried in the water phase and being present from about 5 to about 30 parts by weight based on 100 parts by weight of the prepolymer, provided that when said carbon compound is wood cellulose it is present from about 2 to about 10 parts by weight of the prepolymer, and said carbon compound not functioning as a gelatinizing agent at the concentration employed, and
- b. spraying the mixture onto the substrate.
Dependencies are inferred from the claim text.