Elastomeric Coatings Having Hydrophobic and/or Oleophobic Properties

Abstract

This disclosure deals with novel formulations to create highly durable hydrophobic, superhydrophobic, oleophobic and/or superoleophobic surfaces that can be nearly transparent. The formulations of this invention can be applied by dip, spray and painting processes.

1 . A system for forming a coating comprising:
 A) a first component which comprises:
 i) an elastomeric binder comprising one or more styrenic block copolymers, wherein said elastomeric binder comprises from about 10% to about 30% of said one or more styrenic block copolymers by weight; 
 ii) optionally, one or more independently selected first particles having a size of about 30 microns to about 225 microns, wherein, when said first particles are present, the first component comprises from about 0.01% to about 5% of said first particles by weight; and 
 iii) one or more solvents; and 
   B) a second component which either comprises:
 i) one or more independently selected second particles having a size of about 1 nanometer to about 25 microns, wherein said second particles comprise one or more independently selected alkyl, haloalkyl, or perfluoroalkyl moieties bound, either directly or indirectly, to said second particles, and 
 ii) optionally, one or more solvents; 
   or comprises per 100 parts by weight:
 i) 0.1 to 3.5 parts by weight of one or more independently selected second particles having a size of about 1 nanometer to about 25 microns, wherein said second particles comprise one or more independently selected alkyl, haloalkyl, or perfluoroalkyl moieties bound, either directly or indirectly, to said second particles, or one or more siloxanes or silazanes associated with said second particles; 
 ii) 0.1 to 1.0 parts by weight of a fluorinated polyolefin;
 and/or
 0.06 to 0.6 parts by weight of a Fluoroethylene-Alkyl Vinyl Ether (FEVE) copolymer, having an average molecular weight of about 1,000 to 3,000; 
 
 
   and
 iii) one or more solvent for the remainder of a total of 100 parts by weight; wherein a coating formed by said system has an elongation at break greater than about 200% and an arithmetical mean roughness value from about 3 microns to about 20 microns, or a ten point mean roughness from about 7 microns to about 100 microns. 
   
     
     
         2 . The system of  claim 1 , wherein one or more of the styrenic block copolymers has a rubber phase crosslinked to the polystyrene phase. 
     
     
         3 . The system according to  claim 1 , wherein one or more of the styrenic block copolymers has a rubber phase comprising polybutadiene, polyisoprene, polyolefin or a mixture of any of those rubber phase components (e.g., linear triblock copolymers of styrene and ethylene/butylene with a polystyrene content of about 8% to about 36% by weight or mixtures of any two or more, three or more, or four or more of such triblock copolymers, any one or more of which may optionally comprise 1% to 3% or 1.4% to 2.0% maleic anhydride). 
     
     
         4 . The system according to  claim 2 , wherein said rubber component comprises 60%-80%, of the elastomer by weight, based on the dry weight of the elastomer present in the first component not including any contribution by the first particles or other materials present in the first component. 
     
     
         5 . The system according to  claim 1 , wherein said first component further comprises one or more colorants, UV stabilizers, antioxidants, rheological agents, and/or fillers. 
     
     
         6 . The system according to  claim 1 , wherein said first component further comprises up to 30% by weight of one or more tackifiers, wherein said one or more styrenic block copolymers and said one or more tackifiers together comprise up to about 30% by weight of said first component. 
     
     
         7 . (canceled) 
     
     
         8 . The system according to  claim 1 , wherein said elastomeric binder comprises one, two, three, or more triblock copolymers. 
     
     
         9 . The system according to  claim 1 , wherein said elastomeric binder comprises one or more styrenic block copolymers of styrene and ethylene/butylene with a polystyrene content of about 8% to about 36% by weight, or mixtures of any two or more, three or more, or four or more of such triblock copolymers. 
     
     
         10 . The system according to  claim 1 , wherein one or more of said styrenic block copolymers present in the elastomeric binder comprise maleic anhydride or a first and a second maleated triblock copolymer of styrene and ethylene/butylene wherein:
 said first maleated triblock copolymer of styrene and ethylene/butylene has a polystyrene content from about 8% to about 14%, with 0.4% to 1.6% substitution of maleic anhydride by weight of the first triblock copolymer; and   said second maleated triblock copolymer of styrene and ethylene/butylene has a polystyrene content of about 22% to about 32%, with 1.1% to 2.5% substitution of maleic anhydride by weight of the second triblock copolymer.   
     
     
         11 .- 14 . (canceled) 
     
     
         15 . The system according to  claim 1 , wherein said first particles are selected from the group consisting of: glass, ceramic, rubber, plastic, thermoplastic, wood, cellulose, metal oxides, silicon dioxide, silicates, tectosilicates, germanium dioxide, plastic particles, carbide particles, nitride particles, boride particles (e.g., zirconium or titanium boride), spinel particles, diamond particles, fly ash particles, fibers and hollow glass spheres, hollow glass particles or hollow plastic particles (e.g., glass, polymer, plastic or thermoplastic particles, spheres, or microspheres), wherein said first particles optionally comprise a colorant (e.g., colored or pigmented glass particles, plastic particles, rubber particles, hollow glass or hollow plastic particles). 
     
     
         16 .- 19 . (canceled) 
     
     
         20 . The system according to  claim 1 , wherein said second particles comprise a metal oxide, an oxide of a metalloid, a silicate, or a glass, wherein said second particles have an average size in the range of from 1 nm to 100 nm or from 2 nm to 200 nm. 
     
     
         21 .- 24 . (canceled) 
     
     
         25 . The system according to  claim 1 , wherein said one or more hydrophobic or oleophobic moieties result from contacting the second particles with one or more silanizing agents of formula (I):
   R 4-n Si—X n   (I)
   where n is an integer from 1 to 3;
 each R is independently selected from
 (i) alkyl or cycloalkyl group optionally substituted with one or more fluorine atoms, 
 (ii) C 1 to 20  alkyl optionally substituted with one or more substituents independently selected from fluorine atoms and C 6 to 14  aryl groups, which aryl groups are optionally substituted with one or more independently selected halo, C 1 to 10  alkyl, C 1 to 10  haloalkyl, C 1 to 10  alkoxy, or C 1 to 10  haloalkoxy substituents, 
 (iii) C 2 to 8  or C 6 to 20  alkyl ether optionally substituted with one or more substituents independently selected from fluorine and C 6 to 14  aryl groups, which aryl groups are optionally substituted with one or more independently selected halo, C 1 to 10  alkyl, C 1 to 10  haloalkyl, C 1 to 10  alkoxy, or C 1 to 10  haloalkoxy substituents, 
 (iv) C 6 to 14  aryl, optionally substituted with one or more substituents independently selected from halo or alkoxy, and haloalkoxy substituents, 
 (v) C 4 to 20  alkenyl or C 4 to 20  alkynyl, optionally substituted with one or more substituents independently selected from halo, alkoxy, or haloalkoxy, and 
 (vi) —Z—((CF 2 ) q (CF 3 )) r , wherein Z is a C 1 to 12  or a C 2 to 8  divalent alkane radical or a C 2 to 12  divalent alkene or alkyne radical, q is an integer from 1 to 12, and r is an integer from 1 to 4; 
 
 each X is independently selected from —H, —Cl, —I, —Br, —OH, —OR 2 , —NHR 3 , or —N(R 3 ) 2  group; 
 each R 2  is an independently selected C 1 to 4  alkyl or haloalkyl group; and 
 each R 3  is an independently selected H, C 1 to 4  alkyl, or haloalkyl group. 
   
     
     
         26 . (canceled) 
     
     
         27 . The system according to  claim 25 , wherein R is —Z—((CF 2 ) q (CF 3 )) r , wherein Z is a C 1 to 12  divalent alkane radical or a C 2 to 12  divalent alkene or alkyne radical, q is an integer from 1 to 12, and r is an integer from 1 to 4. 
     
     
         28 . The system according to  claim 25 , wherein n is 1, 2, or 3. 
     
     
         29 .- 33 . (canceled) 
     
     
         34 . The system according to  claim 1 , wherein said second particles are treated with a silanizing agent selected from the group consisting of: (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane; (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane; (tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane; (heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethyl(dimethylamino)silane; (heptadecafluoro-1,1,2,2-tetrahydrodecyl)tris(dimethylamino)silane; n-octadecyltrimethoxysilane; n-octyltriethoxysilane; nonafluorohexyldimethyl(dimethylamino)silane; dimethyl dichlorosilane; hexamethyldisilazane; octyltrimethoxysilane, and polydimethylsiloxane. 
     
     
         35 . (canceled) 
     
     
         36 . The system according to  claim 1 , wherein said first component and/or said second component further comprises an independently selected solvent and/or propellant. 
     
     
         37 .- 39 . (canceled) 
     
     
         40 . The system according to  claim 1 , wherein said elastomeric binder has an ultimate strength greater than about 20 Mega Pascals (MPa) according to ASTM D412. 
     
     
         41 - 62 . (canceled)