Alkyl sulfate / alkyl ether sulfate gypsum foamer

Abstract

A surfactant composition is disclosed comprising a first alkyl sulfate surfactant, optionally a second alkyl sulfate surfactant, and optionally an alkyl ether sulfate. The first and second alkyl sulfate surfactants have Formula (1): R1—OSO3−+M1(1) and the ether sulfate has Formula (2): R2—(OCH2CH2)yOSO3−30 M2(2) in which R1 and R2 are independently selected linear or branched alkyl or a combination thereof having from 6 to 14 carbon atoms, y has an average value from 0.1 to 5, and M1 and M2 are cations independently selected from sodium, calcium, ammonium, or a combination of two or all of these. Use of the composition as a foaming agent for gypsum slurries, and of the gypsum slurries for formation of gypsum boards, are disclosed.

1 . A surfactant composition comprising:
 30% to 60% by weight of a first alkyl sulfate surfactant having Formula (1):
   R 1 —OSO 3   −   + M 1   (1)
 
   
       in which R 1  is linear or branched alkyl having from 6 to 14 carbon atoms and M 1  is a cation selected from sodium, calcium, ammonium, or a combination of two or all of these;
 40% to 70% by weight of a second alkyl sulfate surfactant different from the first alkyl sulfate surfactant, also having Formula (1):
   R 1 —OSO 3   −   + M 1   (1)
 
 
 
       in which R 1  is linear or branched alkyl having from 6 to 14 carbon atoms and M 1  is a cation selected from sodium, calcium, ammonium, or a combination of two or all of these; and
 0% to 7% by weight of an alkyl ether sulfate comprising Formula (2):
   R 2 −(OCH 2 CH 2 ) y OSO 3   −   + M 2   (2)
 
 
 
       in which R 2  is branched alkyl or linear alkyl or a combination thereof having from 6 to 14 carbon atoms, y has an average value from 0.1 to 5, and M 2  is a cation selected from sodium, calcium, ammonium, or a combination of two or all of these. 
     
     
         2 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 8-10  alkyl sulfate, and the alkyl ether sulfate is a C 6  alkyl ether sulfate. 
     
     
         3 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 9  alkyl sulfate, and the alkyl ether sulfate is a C 6  alkyl ether sulfate. 
     
     
         4 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8-10  alkyl sulfate, the second alkyl sulfate is a C 9-11  alkyl sulfate, and the alkyl ether sulfate is a C 6  alkyl ether sulfate. 
     
     
         5 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 9-11  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 6  alkyl ether sulfate. 
     
     
         6 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 6  alkyl ether sulfate. 
     
     
         7 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 8-10  alkyl sulfate, and the alkyl ether sulfate is a C 8-10  alkyl ether sulfate. 
     
     
         8 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 9  alkyl sulfate, and the alkyl ether sulfate is a C 8-10  alkyl ether sulfate. 
     
     
         9 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8-10  alkyl sulfate, the second alkyl sulfate is a C 9-11  alkyl sulfate, and the alkyl ether sulfate is a C 8-10  alkyl ether sulfate. 
     
     
         10 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 9-11  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 8-10  alkyl ether sulfate. 
     
     
         11 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 8-10  alkyl ether sulfate. 
     
     
         12 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 8-10  alkyl sulfate, and the alkyl ether sulfate is a C 9-11  alkyl ether sulfate. 
     
     
         13 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 9  alkyl sulfate, and the alkyl ether sulfate is a C 9-11  alkyl ether sulfate. 
     
     
         14 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8-10  alkyl sulfate, the second alkyl sulfate is a C 9-11  alkyl sulfate, and the alkyl ether sulfate is a C 9-11  alkyl ether sulfate. 
     
     
         15 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 9-11  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 9-11  alkyl ether sulfate. 
     
     
         16 . The surfactant composition of  claim 1 , in which the first alkyl sulfate is a C 8  alkyl sulfate, the second alkyl sulfate is a C 10-12  alkyl sulfate, and the alkyl ether sulfate is a C 9-11  alkyl ether sulfate. 
     
     
         17 . The surfactant composition of  claim 1 , in which the average degree of ethoxylation is 0.8 to 3 moles of ethylene oxide per mole of alkyl ether sulfate. 
     
     
         18 . The surfactant composition of  claim 1 , in which the average degree of ethoxylation is 1.8 to 2.8 moles of ethylene oxide per mole of alkyl ether sulfate. 
     
     
         19 . The surfactant composition of  claim 1 , in which the average degree of ethoxylation is about 2 moles of ethylene oxide per mole of alkyl ether sulfate. 
     
     
         20 . The surfactant composition of  claim 1 , in which the average degree of ethoxylation is about 2.2 moles of ethylene oxide per mole of alkyl ether sulfate. 
     
     
         21 . The surfactant composition of  claim 1 , in which the average degree of ethoxylation is about 2.4 moles of ethylene oxide per mole of alkyl ether sulfate. 
     
     
         22 . A surfactant composition comprising:
 from 70 to 100 wt. % by total surfactant weight of a linear or branched alkyl sulfate; and   from 0 to 30 wt. % by total surfactant weight of a linear or branched alkyl ether sulfate; in which   the linear or branched alkyl sulfate comprises the structure of Formula (1):
   R 1 —OSO 3   −   + M 1   (1)
 
   
       in which R 1  is linear or branched alkyl having from 6 to 14 carbon atoms and M 1  is a cation;
 the linear or branched alkyl ether sulfate comprises the structure of Formula (2):
   R 2 —(OCH 2 CH 2 ) y OSO 3   −   + M 2   (2)
 
 
 
       in which R 2  is branched alkyl or linear alkyl or a combination thereof having from 6 to 14 carbon atoms, y has an average value from 0.1 to 5, M 2  is a cation, and
 M 1  and M 2  are independently selected, and can be the same or different. 
 
     
     
         23 . A gypsum slurry comprising gypsum, water, and the surfactant composition of  claim 22   
     
     
         24 . A gypsum board comprising a core and facing sheets, the core comprising the gypsum slurry of  claim 23  and having multiple foam voids. 
     
     
         25 . A surfactant composition comprising:
 from 91 to 99.5 wt. % by total surfactant weight of a linear or branched alkyl sulfate having the structure of Formula (1), an average number of carbon atoms, n m , in R 1  between 10 and 11, and the following proportions by weight of species of Formula (1):
 7% to 12% in which R 1  is straight or branched C 9 H 19 ; 
 42% to 59% in which R 1  is straight or branched C 10 H 21 ; 
 15% to 29% in which R 1  is straight or branched C 11 H 23 ; 
 7% to 15% in which R 1  is straight or branched C 12 H 25 ; and 
   from 0.5 to 9 wt. % by total surfactant weight of a linear or branched alkyl ether sulfate having the structure of Formula (2), an average number of carbon atoms, n m , in R 2  between 10 and 11, and an average value of y from 0.5 to 2.5.   
     
     
         26 . A gypsum slurry comprising gypsum, water, and the surfactant composition of  claim 25 . 
     
     
         27 . A gypsum board comprising a core and facing sheets, the core comprising the gypsum slurry according to  claim 26  having multiple foam voids. 
     
     
         28 . A surfactant composition comprising:
 from 97.5 to 99.5 wt. % by total surfactant weight of a linear or branched alkyl sulfate having the structure of Formula (1), an average number of carbon atoms, n m , in R 1  between 9 and 10, and the following proportions by weight of species of Formula (1):
 25% to 47% in which R 1  is straight or branched C 8 H 17 ; 
 38% to 55% in which R 1  is straight or branched C 10 H 21 ; 
 12% to 20% in which R 1  is straight or branched C 12 H 25 ; and 
   from 0.5 to 2.5 wt. % by total surfactant weight of a linear or branched alkyl ether sulfate having the structure of Formula (2), an average number of carbon atoms, n m , in R 2  between 9 and 10, and an average value of y from 0.5 to 2.5.   
     
     
         29 . A gypsum slurry comprising gypsum, water, and the surfactant composition of  claim 28 . 
     
     
         30 . A gypsum board comprising a core and facing sheets, the core comprising the gypsum slurry according to  claim 29  and having multiple foam voids.