Erosion resistant coatings for leading edges of airfoils
AssigneeHontek Corporation
InventorShek C. Hong
Life of this patent
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Abstract
A polyurethane or polyurea coating for use in protecting a leading edge substrate on an airfoil against liquid or solid particle erosion, the composition made from an isocyanate-terminated prepolymer and curing agents, such as polyaspartic esters, aldimines and ketimines with optional flatting agent for matte coatings.
Claims38
A polyurethane or polyurea rain erosion resistant coating composition for protecting a leading edge substrate on an airfoil against liquid and solid particle erosion, comprising:
- an isocyanate-terminated prepolymer with an isocyanate content of about 0.5 to about 40 weight percent, based on the weight of the prepolymer;
- a curing agent selected from the group consisting of an aldimine, a ketimine, a polyaspartic ester, a polyamine, a polyol and mixtures thereof;
- and
- a flatting agent, having a particle size of about 1 to about 20 micrometers present at a level of about 1 to about 15 weight percent based on the total weight of the said polyurethane or polyurea coating composition, and selected from the group consisting of silica, polymeric beads, talc, alumina, calcium carbonate, urea-formaldehydes and mixtures thereof;
- said polyurethane or polyurea rain erosion resistant coating composition in dry cured form having a tensile strength greater than 1000 psi (70 kg/cm2), an elongation at break greater than 350%, a tensile set after break of less than 150%, and a Shore A hardness of 44A to 95A as measured at 68° F., a matte finish as measured according to ASTM D 523-89 (1999) with an 85 degree surface gloss less than 15, and having a rain erosion resistance of greater than or equal to 70 minutes.
A polyurethane coating composition for protecting a leading edge substrate on an airfoil against liquid and solid particle erosion comprising:
- a water based polyurethane dispersion with a flatting agent dispersed therein, said flatting agent having a particle size of about 1 to about 20 micrometers present at a level of about 1 to about 15 weight percent based on the total weight of the said polyurethane coating composition, and selected from the group consisting of silica, polymeric beads, talc, alumina, calcium carbonate, urea-formaldehydes and mixtures thereof, said water based polyurethane dispersion in dry form having a tensile strength greater than 1000 psi (70 kg/cm2), an elongation at break greater than 350%, a tensile set after break of less than 150%, and a Shore A hardness of 44A to 95A as measured at 68° F., having a matte finish as measured according to ASTM D 523-89 (1999) with an 85 degree surface gloss less than 15, and having a rain erosion resistance of greater than or equal to 70 minutes.
Dependencies are inferred from the claim text.