Silicones having improved chemical resistance and curable silicone compositions having improved migration resistance

Abstract

A composition is prepared by mixing components including: (I) a polyorganosiloxane having an average of at least two unsaturated organic groups per molecule, with the proviso that component (I) is free of fluorine atoms; optionally (II) an organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, with the proviso that component (II) is free of fluorine atoms; (III) a hydrosilylation catalyst; (IV) a fluoroorganosilicone, with the provisos that (1) component (IV) has at least one functional group reactive with component (I), component (II), or both, (2) when component (II) is not present, then component (IV) has an average of at least two silicon-bonded hydrogen atoms per molecule, and (3) component (IV) is added to the composition in an amount sufficient to provide chemical resistance to a cured product of the composition; and (V) an adhesion promoter.

1 . A composition prepared by mixing components comprising: 
 (I) a polyorganosiloxane having an average of at least two unsaturated organic groups per molecule, 
 with the proviso that component (I) is free of fluorine atoms;  
   optionally (II) an organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, 
 with the proviso that component (II) is free of fluorine atoms;  
   (III) a hydrosilylation catalyst;    (IV) a fluoroorganosilicone, 
 with the provisos that  
 (1) component (IV) has at least one functional group reactive with component (I), component (II), or both,  
 (2) when component (II) is not present, then component (IV) has an average of at least two silicon-bonded hydrogen atoms per molecule, and  
 (3) component (IV) is added to the composition in an amount sufficient to provide chemical resistance to a cured product of the composition; and (V) an adhesion promoter,  
 with the proviso that component (IV) and component (V) are added to the composition in amounts sufficient to provide resistance to Bleed to the composition.  
   
     
     
         2 . The composition of  claim 1 , where component (I) comprises a polyorganosiloxane of the formula: 
 (a) R 1   3 SiO(R 1   2 SiO) α (R 1 R 2 SiO) β SiR 1   3 ,    (b) R 3   2 R 4 SiO(R 3   2 SiO) χ (R 3 R 4 SiO) δ SiR 3   2 R 4 , or    (c) a combination thereof, where 
 α has an average value of 0 to 2000,  
 β has an average value of 2 to 2000,  
 each R 1  is independently a monovalent organic group,  
 each R 2  is independently an unsaturated monovalent organic group,  
 χ has an average value of 0 to 2000,  
 δ has an average value of 0 to 2000,  
 each R 3  is independently a monovalent organic group, and  
 each R 4  is independently an unsaturated monovalent organic group.  
   
     
     
         3 . The composition of  claim 1 , where component (I) comprises: 
 i) dimethylvinylsiloxy-terminated polydimethylsiloxane,    ii) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),    iii) dimethylvinylsiloxy-terminated polymethylvinylsiloxane,    iv) trimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),    v) trimethylsiloxy-terminated polymethylvinylsiloxane,    vi) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylphenylsiloxane),    vii) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/diphenylsiloxane),    viii) phenyl,methyl,vinyl-siloxy-terminated polydimethylsiloxane,    ix) dimethyl-acryloyloxypropyl-siloxy-terminated polydimethylsiloxane,    x) dimethyl-methacryloyloxypropyl-siloxy-terminated polydimethylsiloxane,    xi) dimethylhexenylsiloxy-terminated polydimethylsiloxane,    xii) dimethylhexenylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),    xiii) dimethylhexenylsiloxy-terminated polymethylhexenylsiloxane,    xiv) trimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),    xv) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylcyanopropylsiloxane), or    xvi) combinations thereof.    
     
     
         4 . The composition of  claim 1 , where component (I) comprises an MQ resin consisting essentially of R 5   3 SiO 1/2  units and SiO 4/2  units, a TD resin consisting essentially of R 5 SiO 3/2  units and R 5   2 SiO 2/2  units, an MT resin consisting essentially of R 5   3 SiO 1/2  units and R 5 SiO 3/2  units, an MTD resin consisting essentially of R 5   3 SiO 1/2  units, R 5 SiO 3/2  units, and R 5   2 SiO 2/2  units, or a combination thereof, where 
 each R 5  is a monovalent organic group of 1 to 20 carbon atoms, and    the resin contains an average of 3 to 30 mole percent of unsaturated organic groups.    
     
     
         5 . The composition of  claim 1 , where component (II) is present and component (II) comprises siloxane units selected from HR 6   2 SiO 1/2 , R 6   3 SiO 1/2 , HR 6 SiO 2/2 , R 6   2 SiO 2/2 , R 6 SiO 3/2 , SiO 4/2 , or combinations thereof; where each R 6  is independently selected from monovalent organic groups free of aliphatic unsaturation.  
     
     
         6 . The composition of  claim 1 , where component (II) is present and component (II) comprises a compound of the formula: 
 (a) R 7   3 SiO(R 7   2 SiO) ε (R 7 HSiO) φ SiR 7   3 , or    (b) R 8   2 HSiO(R 8   2 SiO) γ (R 8 HSiO) η SiR 8   2 H,    (c) a combination thereof, where 
 ε has an average value of 0 to 2000,  
 φ has an average value of 2 to 2000,  
 each R 7  is independently a monovalent organic group free of aliphatic unsaturation,  
 γ has an average value of 0 to 2000,  
 η has an average value of 0 to 2000, and  
 each R 8  is independently a monovalent organic group free of aliphatic unsaturation.  
   
     
     
         7 . The composition of  claim 1 , where component (II) is present and component (II) comprises: 
 i) dimethylhydrogensiloxy-terminated polydimethylsiloxane,    ii) dimethylhydrogensiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane),    iii) dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane,    iv) trimethylsiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane),    v) trimethylsiloxy-terminated polymethylhydrogensiloxane,    vi) a resin consisting essentially of H(CH 3 ) 2 SiO 1/2  units and SiO 4/2  units, and    vii) combinations thereof.    
     
     
         8 . The composition of  claim 1 , where component (III) comprises a platinum metal, a rhodium metal, or an organometallic compound.  
     
     
         9 . The composition of  claim 1 , where component (III) comprises a microencapsulated hydrosilylation catalyst.  
     
     
         10 . The composition of  claim 1 , where component (IV) comprises a compound of the formula: 
 (a) R 9   3 SiO(R 9   2 SiO) ι (R 9 R 10 SiO) θ SiR 9   3 ,    (b) R 11   2 R 12 SiO(R 11   2 SiO) κ (R 11 R 12 SiO) λ SiR 11   2 R 12 ,    (c) F 3 C(CF 2 ) ν R 13 —Si—[O—Si(R 14 ) 2 (R 15 )] 3 ,    (d) a resinous or branched structure consisting essentially of R 15 R 14   2 SiO 1/2  units, CF 3 (CF 2 ) ν R 13 SiO 3/2  units, and optionally SiO 4/2  units, or    (e) a combination thereof; where 
 ι has an average value of 0 to 2000,  
 θ has an average value of 1 to 500,  
 each R 9  is independently a hydrogen atom or a monovalent organic group, with the proviso that at least one R 9  is a hydrogen atom or an unsaturated monovalent organic group;  
 each R 10  is independently a fluoro-functional organic group;  
 κ has an average value of 0 to 2000;  
 λ has an average value of 0 to 500;  
 each R 11  is independently a hydrogen atom or a monovalent organic group, with the proviso that at least one R 11  is a hydrogen atom or an unsaturated monovalent organic group;  
 each R 12  is independently a fluoro-functional organic group;  
 each R 13  is independently a divalent organic group;  
 each R 14  is independently a monovalent hydrocarbon group free of aliphatic unsaturation;  
 ν is 0 to 10; and  
 each R 15  is independently a hydrogen atom or an unsaturated monovalent organic group.  
   
     
     
         11 . The composition of  claim 1 , where component (IV) comprises 
 i) dimethylvinylsiloxy-terminated polymethyl3,3,3-trifluoropropyl siloxane,    ii) dimethylvinylsiloxy-terminated poly(methylhydrogensiloxane/methyl-6,6,6,5,5,4,4,3,3-nonafluorohexylsiloxane),    iii) trimethylsiloxy-terminated poly(methylhydrogensiloxane/methyl-6,6,6,5,5,4,4,3,3-nonafluorohexylsiloxane),    iv) trimethylsiloxy-terminated poly(methylhydrogensiloxane/methyl-6,6,6,5,5,4,4,3,3-nonafluorohexylsiloxane), or    v) combinations thereof.    
     
     
         12 . The composition of  claim 1 , where component (V) comprises a transition metal chelate, an alkoxysilane, a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane, or a combination thereof.  
     
     
         13 . The composition of  claim 1 , where component (V) comprises an unsaturated alkoxysilane, an epoxy-functional alkoxysilane, an epoxy-functional siloxane, or a combination thereof.  
     
     
         14 . The composition of  claim 1 , where component (V) comprises an alkoxysilane of the formula R 28   μ Si(OR 29 ) (4-μ) , where 
 μ is 1, 2, or 3,    each R 28  is independently a monovalent organic group, with the proviso that at least one R 28  is an unsaturated organic group or an epoxy-functional group, and    each R 29  is independently an unsubstituted, saturated hydrocarbon group of at least 1 carbon atom.    
     
     
         15 . The composition of  claim 1 , where component (V) comprises 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (epoxycyclohexyl)ethyldimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyl trimethoxysilane, 3-acryloyloxypropyl triethoxysilane, or combinations thereof.  
     
     
         16 . The composition of  claim 1 , where component (V) comprises a reaction product of a hydroxy-terminated polyorganosiloxane with an epoxy-functional alkoxysilane or an unsaturated alkoxysilane, or a physical blend of a hydroxy-terminated polyorganosiloxane with an epoxy-functional alkoxysilane or an unsaturated alkoxysilane.  
     
     
         17 . The composition of  claim 1 , further comprising (VI) an unsaturated ester-functional compound, (VII) a void reducing agent, (VIII) a pigment, (IX) a filler, (X) a cure modifier, (XI) a rheology modifier, (XII) a spacer, or a combination thereof.  
     
     
         18 . The composition of  claim 1 , further comprising an acid acceptor, an anti-oxidant, a stabilizer, a flame retardant, a flow control additive, a reactive diluent, an anti-settling agent, a silylating agent, a desiccant, a blowing agent, or combinations thereof.  
     
     
         19 . A kit comprising Part A and Part B, where Part A comprises 
 (I) a polyorganosiloxane having an average of at least two unsaturated organic groups per molecule, with the proviso that component (I) is free of fluorine atoms,    (III) a hydrosilylation catalyst,    optionally (IV) a fluoroorganosilicone, 
 with the provisos that  
 (1) component (IV) has at least one functional group reactive with component (I), component (II), or both,  
 (2) when component (II) is not present in the kit, then component (IV) has an average of at least two silicon-bonded hydrogen atoms per molecule, and  
 (3) component (IV) is added to the composition in an amount sufficient to provide chemical resistance to a cured product of the composition;  
   optionally (V) an adhesion promoter, 
 with the proviso that components (IV) and (V) are added in amounts sufficient to provide resistance to Bleed to a composition prepared by combining Part A and Part B,  
   optionally (VI) an unsaturated ester-functional compound,    optionally (VII) a void reducing agent,    optionally (VIII) a pigment,    optionally (IX) a filler,    optionally (X) an cure modifier,    optionally (XI) a rheology modifier, and    optionally (XII) a spacer; and    Part B comprises    optionally(I) a polyorganosiloxane having at least two terminally-unsaturated organic groups per molecule,    optionally (II) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule, where component (II) is free of fluorine atoms,    optionally (IV) a fluoroorganosilicone 
 with the provisos that  
 (1) component (IV) has at least one functional group reactive with component (I), component (II), or both,  
 (2) when component (II) is not present in the kit, then component (IV) has an average of at least two silicon-bonded hydrogen atoms per molecule, and  
 (3) component (IV) is added to the composition in an amount sufficient to provide chemical resistance to a cured product of the composition; optionally (V) an adhesion promoter,  
 with the proviso that components (IV) and (V) are added in amounts sufficient to provide resistance to Bleed to a composition prepared by combining Part A and Part B,  
   optionally (VI) an unsaturated ester-functional compound,    optionally (VII) a void reducing agent,    optionally (VIII) a pigment,    optionally (IX) a filler,    optionally (X) an cure modifier,    optionally (XI) a rheology modifier, and    optionally (XII) a spacer;    with the provisos that    at least one of Part A and Part B contains component (IV),    at least one of Part A and Part B contains component (V), and    Part B contains at least one of components (II), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), and (XII).    
     
     
         20 . The kit of  claim 19 , further comprising information or instructions or both as how to use the kit, how to combine Part A and Part B, or how to cure the resulting combination, or combinations thereof.  
     
     
         21 . A method comprising: 
 1) adding a fluoroorganosilicone and an adhesion promoter to a composition, where the composition comprises 
 (I) a polyorganosiloxane having an average of at least two unsaturated organic groups per molecule, 
 with the proviso that component (I) is free of fluorine atoms;  
 
 optionally (II) an organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule, and 
 with the proviso that component (II) is free of fluorine atoms;  
 
 (III) a hydrosilylation catalyst; and  
   the fluoroorganosilicone has at least one functional group reactive with component (I), component (II), or both, and    the fluoroorganosilicone is added in an amount sufficient to provide chemical resistance to a cured product of the composition; and    the fluoroorganosilicone and the adhesion promoter are added in amounts sufficient to provide resistance to Bleed to the composition; and    the fluoroorganosilicone has at least one functional group reactive with component (I), component (II), or both; and    when component (II) is not present in the composition, then the fluoroorganosilicone has an average of at least two silicon-bonded hydrogen atoms per molecule; and    the fluoroorganosilicone is added to the composition in an amount sufficient to provide chemical resistance to a cured product of the composition.    
     
     
         22 . A method comprising: 
 (1) applying the composition of  claim 1  to a substrate, and    (2) curing the composition.    
     
     
         23 . The method of  claim 22 , where the substrate comprises an epoxy, a polycarbonate, a poly(butylene terephthalate) resin, a polyamide resin, a blend of polyamide resin with syndiotactic polystyrene, an acrylonitrile-butadiene-styrene, a styrene-modified poly(phenylene oxide), a poly(phenylene sulfide), a vinyl ester, a polyphthalamide, a polyimide, silicon, aluminum, a stainless steel alloy, titanium, copper, nickel, silver, gold, or combinations thereof.  
     
     
         24 . A method comprising 
 (1) applying the composition of  claim 1  to a first substrate,    (2) applying a second substrate to the composition, and    (3) curing the composition;    where one of the first substrate and the second substrate is a semiconductor die.    
     
     
         25 . A method comprising: 
 (a) applying the composition of  claim 1  to one or more substrates, and    (b) curing the composition.    
     
     
         26 . A method comprising: 
 (1) applying the composition of  claim 1  onto a housing,    (2) placing a lid over the housing such that the edges of the lid are in contact with the composition to form an assembly, and    (3) curing the composition to form a sealed housing.    
     
     
         27 . A method comprising: 
 (1) applying the composition of  claim 1  over an electronic circuit board, and    (2) curing the composition to produce a sealed circuit board.    
     
     
         28 . A method comprising: 
 (1) applying the composition of  claim 1  on an electronic substrate,    (2) attaching a semiconductor die to the composition,    (3) curing the composition to produce a bonded composite.    optionally (4) repeating steps (1) to (3) to attach one or more additional semiconductor dice to the semiconductor die,    optionally (5) wire bonding the semiconductor die or semiconductor dice,    optionally (6) cleaning,    optionally (7) overmolding the semiconductor die or semiconductor dice with a molding compound, and    optionally (8) attaching solder balls to form a finished package.