Patent Publication Number: US-2018042221-A1

Title: Freeze stable tetrakis(hydroxymethyl) phosphonium sulfate formulations

Description:
This invention relates to formulations of tetrakis(hydroxymethyl)phosphonium sulfate (THPS) which do not freeze when stored at low temperatures. 
     Formulations of biocidal active ingredients often are stored or used under conditions including extremely low temperatures, including, e.g., oil and gas extraction. Compositions containing THPS and various solvents have been reported in the literature, but compositions which are stable at low temperatures are not known. For example, WO2015/017705 discloses compositions containing THPS and various solvents, but this reference does not suggest the compositions claimed herein. 
     STATEMENT OF THE INVENTION 
     The present invention is directed to a composition comprising:
     (a) tetrakis(hydroxymethyl)phosphonium sulfate (THPS); (b) water; and (c) 1,2-propanediol; wherein the weight percentages of (a), (b) and (c) are within the area on a ternary phase diagram for (a), (b) and (c) bounded by five points: (A) 20% THPS/40% water/40% 1,2-propanediol; (B) 20% THPS/20% water/60% 1,2-propanediol; (C) 65% THPS/22% water/13% 1,2-propanediol; (D) 65% THPS/25% water/10% 1,2-propanediol; and (E) 40% THPS/28% water/32% 1,2-propanediol.   

     The present invention is further directed to a composition comprising:
     (a) tetrakis(hydroxymethyl)phosphonium sulfate (THPS); (b) water; and (c) ethylene glycol; wherein the weight percentages of (a), (b) and (c) are within the area on a ternary phase diagram for (a), (b) and (c) bounded by the three points: (J) 7% THPS/44% water/50% ethylene glycol; (K) 25% THPS/14% water/61% ethylene glycol; and (L) 68% THPS/22% water/10% ethylene glycol.   

     The present invention is further directed to a composition comprising:
     (a) tetrakis(hydroxymethyl)phosphonium sulfate (THPS); (b) water; and (c) glycerine; wherein the weight percentages of (a), (b) and (c) are within the area on a ternary phase diagram for (a), (b) and (c) bounded by the three points: (0) 10% THPS/45% water/45% glycerine; (P) 10% THPS/25% water/65% glycerine; and (Q) 44% THPS/18% water/38% glycerine.   

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a ternary phase diagram for THPS/water/1,2-propanediol, with the claimed area marked by the points A, B, C, D and E which are the vertices of a polygon. The symbol “▴” indicates a point for which the mixture of that composition is a free-flowing single liquid phase after 24 hour storage at −40° C. The symbol “▪” indicates a point for which the mixture is solid under these conditions and “♦” indicates a point for which the mixture is either an extremely viscous fluid or a fused glassy solid under these conditions. 
         FIG. 2  is a ternary phase diagram for THPS/water/ethylene glycol. The symbols are the same as those indicated for  FIG. 1 . The claimed area is marked by the points J, K and L, which are the vertices of a triangle. 
         FIG. 3  is a ternary phase diagram for THPS/water/glycerine. The symbols are the same as those indicated for  FIG. 1 . The claimed area is marked by the points O, P and Q, which are the vertices of a triangle. 
         FIG. 4  is a ternary phase diagram for THPS/water/methanol. The symbols are the same as those indicated for  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION F THE INVENTION 
     Unless otherwise specified, temperatures are in degrees centigrade (° C.), and references to percentages are by weight (wt %). All operations were performed at room temperature (20-25° C.), unless otherwise specified. 1,2-propanediol is also known as propylene glycol (PG). A polygon is a plane figure having at least three sides, with all sides being straight lines. 
     Compositions of THPS, water and PG within the scope of this invention are those for which the weight percentages are within the polygon defined by the five points, A, B, C, D and E listed above on a ternary phase diagram for THPS, water and PG. In one preferred embodiment of the invention, the composition is within the area defined by the points: (A), (B); (F) 30% THPS/20.5% water/49.5% 1,2-propanediol; and (G) 30% THPS/34% water/36% 1,2-propanediol; or the area defined by the points: (C), (D), (H) 47% THPS/27% water/26% 1,2-propanediol; and (I) 47% THPS/21.5% water/21.5% 1,2-propanediol. Each of the two areas in the preceding description is a trapezoid. 
     Compositions of THPS, water and ethylene glycol within the scope of this invention are those for which the weight percentages are within the triangle defined by the three points, J, K and L listed above on a ternary phase diagram for THPS, water and ethylene glycol. In one preferred embodiment of the invention, the composition is within the area defined by the points: (M) 20% THPS/39% water /41% ethylene glycol; (N) 24% THPS/18% water/58% ethylene glycol; and (L). 
     Compositions of THPS, water and glycerine within the scope of this invention are those for which the weight percentages are within the triangle defined by the three points, O, P and Q listed above on a ternary phase diagram for THPS, water and glycerine. In one preferred embodiment of the invention, the composition is within the area defined by the points: (R) 15% THPS/37% water/ 48% glycerine; (S) 15% THPS/28% water/57% glycerine; and (Q) 
     The composition may contain small amounts of other ingredients, e.g., solvents, process impurities associated with the commercial active ingredient, surfactants, defoamer agents, dispersing agents, brand identification markers; preferably no more than 5 wt % of other ingredients, preferably no more than 4 wt %, preferably no more than 3 wt %, preferably no more than 2 wt %, preferably no more than 1 wt %, preferably no more than 0.5 wt %, preferably no more than 0.3 wt %. A composition containing other ingredients is evaluated by normalizing the total of the weight percentages of THPS, water and 1,2-propanediol to 100%; 
     the composition is within the scope of the present invention if the point on a ternary phase diagram representing these normalized amounts is within the stated area. 
     The composition of the present invention is a free-flowing liquid even after storage at −40° C. Known aqueous solutions of THPS are not physically stable under these conditions. The prior art provided no indication that one could make a solution of THPS that would not freeze or phase-separate at −40° C. 
     EXAMPLES 
     Example 1 
     To a glass sample vial was added: (i) commercial aqueous solution of bis[tetrakis(hydroxymethyl)phosphonium] sulfate containing 76.5 wt % THPS and (ii) water, or an alcohol selected from methanol, ethanol or isopropanol (IPA), or a combination of water and one of the listed alcohols in an amount sufficient to produce a 20 g sample. Each sample was then placed in a −40° C. freezer. The samples were observed after 24 hours and the physical form was noted in Table 1. Reexamination of the samples after several days revealed them to be unchanged from the original observation. Only those samples diluted with a combination of water and methanol appeared as free flowing homogeneous liquids. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Impact of Alcohol Diluents 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Sample 
                 THPS 
                 Water 
                 Alcohol 
                 MeOH 
                 EtOH 
                 IPA 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 control 
                 76.5% 
                 23.5% 
                 0.0% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 water only 
                 61.2% 
                 38.8% 
                 0.0% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 water only 
                 51.0% 
                 49.0% 
                 0.0% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 water only 
                 25.5% 
                 74.5% 
                 0.0% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 Alcohol 
                 61.2% 
                 18.8% 
                 20.0% 
                 small bi- 
                 bi-layer 
                 bi-layer 
               
               
                 Only 
                   
                   
                   
                 layer 
                 liquid 
                 liquid 
               
               
                   
                   
                   
                   
                 liquid 
               
               
                 Alcohol 
                 51.0% 
                 15.7% 
                 33.3% 
                 bi-layer 
                 bi-layer 
                 bi-layer 
               
               
                 Only 
                   
                   
                   
                 liquid 
                 liquid 
                 liquid 
               
               
                 Alcohol 
                 25.5% 
                 7.8% 
                 66.7% 
                 bi-layer 
                 bi-layer 
                 bi-layer 
               
               
                 Only 
                   
                   
                   
                 liquid/ 
                 liquid 
                 liquid 
               
               
                   
                   
                   
                   
                 solid 
               
               
                 Equal Blend 
                 61.2% 
                 28.8% 
                 10.0% 
                 Free 
                 Frozen 
                 Frozen 
               
               
                   
                   
                   
                   
                 flowing 
               
               
                   
                   
                   
                   
                 liquid 
               
               
                 Equal Blend 
                 51.0% 
                 32.3% 
                 16.7% 
                 Free 
                 Frozen 
                 Frozen 
               
               
                   
                   
                   
                   
                 flowing 
               
               
                   
                   
                   
                   
                 liquid 
               
               
                 Equal Blend 
                 25.5% 
                 41.2% 
                 33.3% 
                 Free 
                 Frozen 
                 Frozen 
               
               
                   
                   
                   
                   
                 flowing 
               
               
                   
                   
                   
                   
                 liquid 
               
               
                 Low 
                 61.2% 
                 33.8% 
                 5.0% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 Alcohol 
               
               
                 Low 
                 51.0% 
                 40.7% 
                 8.3% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 Alcohol 
               
               
                 Low 
                 25.5% 
                 57.8% 
                 16.7% 
                 Frozen 
                 Frozen 
                 Frozen 
               
               
                 Alcohol 
               
               
                 High 
                 61.2% 
                 23.8% 
                 15.0% 
                 bi-layer 
                 bi-layer 
                 bi-layer 
               
               
                 Alcohol 
                   
                   
                   
                 liquid 
                 liquid 
                 liquid/ 
               
               
                   
                   
                   
                   
                   
                   
                 solid 
               
               
                 High 
                 51.0% 
                 24.0% 
                 25.0% 
                 bi-layer 
                 bi-layer 
                 bi-layer 
               
               
                 Alcohol 
                   
                   
                   
                 liquid 
                 liquid 
                 liquid/ 
               
               
                   
                   
                   
                   
                   
                   
                 solid 
               
               
                 High 
                 25.5% 
                 24.5% 
                 50.0% 
                 bi-layer 
                 bi-layer 
                 bi-layer 
               
               
                 Alcohol 
                   
                   
                   
                 liquid 
                 liquid 
                 liquid/ 
               
               
                   
                   
                   
                   
                   
                   
                 solid 
               
               
                   
               
            
           
         
       
     
     Example 2 
     Comparative 
     To a glass sample vial was added commercial solution of bis[tetrakis(hydroxymethyl)phosphonium] sulfate solution, water and methanol in an amount sufficient to produce a 20 g sample. The composition of each sample is shown below in table 2. Each sample was then placed in a −40° C. freezer. The samples were observed after 24 hours and the physical form was noted in Table 2. Reexamination of the samples after several days revealed them to be unchanged from the original observation. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 THPS 
                 Water 
                 Methanol 
                 Condition 
               
               
                   
               
             
            
               
                     10% 
                     10% 
                     80% 
                 Free flowing liquid 
               
               
                 10.0% 
                 20.0% 
                 70.0% 
                 Free flowing liquid 
               
               
                 10.0% 
                 25.0% 
                 65.0% 
                 Free flowing liquid 
               
               
                 10.0% 
                 35.0% 
                 55.0% 
                 Free flowing liquid 
               
               
                 10.0% 
                 45.0% 
                 45.0% 
                 Free flowing liquid 
               
               
                 10.0% 
                 55.0% 
                 35.0% 
                 Free flowing liquid 
               
               
                 10.0% 
                 60.0% 
                 30.0% 
                 Frozen 
               
               
                 10.0% 
                 70.0% 
                 20.0% 
                 Frozen 
               
               
                     15% 
                     25% 
                     60% 
                 Free flowing liquid 
               
               
                 20.0% 
                 20.0% 
                 60.0% 
                 Bi-layer liquid 
               
               
                 20.0% 
                 30.0% 
                 50.0% 
                 Bi-layer liquid 
               
               
                 25.0% 
                 30.0% 
                 45.0% 
                 bi-layer liquid 
               
               
                 25.0% 
                 32.5% 
                 42.5% 
                 Free flowing liquid 
               
               
                 25.0% 
                 35.0% 
                 40.0% 
                 Free flowing liquid 
               
               
                 25.0% 
                 45.0% 
                 30.0% 
                 Free flowing liquid 
               
               
                 25.0% 
                 48.0% 
                 27.0% 
                 Free flowing liquid 
               
               
                 25.0% 
                 50.0% 
                 25.0% 
                 Frozen 
               
               
                 25.5% 
                  7.8% 
                 66.7% 
                 bi-layer liquid/solid 
               
               
                 25.5% 
                 24.5% 
                 50.0% 
                 bi-layer liquid 
               
               
                 25.5% 
                 41.2% 
                 33.3% 
                 Free flowing liquid 
               
               
                 25.5% 
                 57.8% 
                 16.7% 
                 Frozen 
               
               
                 25.5% 
                 74.5% 
                  0.0% 
                 Frozen 
               
               
                 30.0% 
                 30.0% 
                 40.0% 
                 Bi-layer liquid 
               
               
                 30.0% 
                 35.0% 
                 35.0% 
                 Bi-layer liquid 
               
               
                     30% 
                     35% 
                     35% 
                 Free flowing liquid 
               
               
                 30.0% 
                 42.5% 
                 27.5% 
                 Free flowing liquid 
               
               
                 30.0% 
                 47.0% 
                 23.0% 
                 Frozen 
               
               
                 30.0% 
                 57.0% 
                 13.0% 
                 Frozen 
               
               
                 40.0% 
                 30.0% 
                 30.0% 
                 bi-layer liquid 
               
               
                 40.0% 
                 33.0% 
                 27.0% 
                 Free flowing liquid 
               
               
                 40.0% 
                 40.0% 
                 20.0% 
                 Free flowing liquid 
               
               
                 40.0% 
                 42.0% 
                 18.0% 
                 Free flowing liquid 
               
               
                     40% 
                     45% 
                     15% 
                 Frozen 
               
               
                 50.0% 
                 37.0% 
                 13.0% 
                 Frozen 
               
               
                 50.0% 
                     28% 
                     22% 
                 Free flowing liquid 
               
               
                 51.0% 
                 15.7% 
                 33.3% 
                 bi-layer liquid 
               
               
                 51.0% 
                 24.0% 
                 25.0% 
                 bi-layer liquid 
               
               
                 51.0% 
                 32.3% 
                 16.7% 
                 Free flowing liquid 
               
               
                 51.0% 
                 40.7% 
                  8.3% 
                 Frozen 
               
               
                 51.0% 
                 49.0% 
                  0.0% 
                 Frozen 
               
               
                     60% 
                     27% 
                     13% 
                 Free flowing liquid 
               
               
                 61.2% 
                 18.8% 
                 20.0% 
                 small bi-layer liquid 
               
               
                 61.2% 
                 23.8% 
                 15.0% 
                 bi-layer liquid 
               
               
                 61.2% 
                 28.8% 
                 10.0% 
                 Free flowing liquid 
               
               
                 61.2% 
                 30.8% 
                  8.0% 
                 Free flowing liquid 
               
               
                 61.2% 
                 33.8% 
                  5.0% 
                 Frozen 
               
               
                 61.2% 
                 38.8% 
                  0.0% 
                 Frozen 
               
               
                 70.0% 
                 25.0% 
                  5.0% 
                 Frozen 
               
               
                 76.5% 
                 23.5% 
                  0.0% 
                 Frozen 
               
               
                   
               
            
           
         
       
     
     Example 3 
     To a glass sample vial was added commercial solution of bis[tetrakis(hydroxymethyl)phosphonium] sulfate solution, water and ethylene glycol in an amount sufficient to produce a 20 g sample. The composition of each sample is shown below in Table 3. Each sample was then placed in a −40° C. freezer. The samples were observed after 24 hours and the physical form was noted in Table 3. Reexamination of the samples after several days revealed them to be unchanged from the original observation. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Ethylene Glycol. 
               
            
           
           
               
               
               
               
            
               
                 THPS 
                 Water 
                 Ethylene Glycol 
                 Condition 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 10.0% 
                 40.0% 
                 50.0% 
                 Liquid 
               
               
                 25.0% 
                 35.0% 
                 40.0% 
                 Liquid 
               
               
                 25.5% 
                 7.8% 
                 66.7% 
                 Frozen 
               
               
                 25.5% 
                 24.5% 
                 50.0% 
                 Slightly Viscous 
               
               
                   
                   
                   
                 Liquid 
               
               
                 25.5% 
                 41.2% 
                 33.3% 
                 Frozen 
               
               
                 25.5% 
                 57.8% 
                 16.7% 
                 Frozen 
               
               
                 25.5% 
                 74.5% 
                 0.0% 
                 Frozen 
               
               
                 38.0% 
                 34.5% 
                 27.5% 
                 Partially Frozen 
               
               
                 50.0% 
                 30.0% 
                 20.0% 
                 Partially Frozen 
               
               
                 51.0% 
                 15.7% 
                 33.3% 
                 Slightly Viscous 
               
               
                   
                   
                   
                 Liquid 
               
               
                 51.0% 
                 24.0% 
                 25.0% 
                 Slightly Viscous 
               
               
                   
                   
                   
                 Liquid 
               
               
                 51.0% 
                 32.3% 
                 16.7% 
                 Frozen 
               
               
                 51.0% 
                 40.7% 
                 8.3% 
                 Frozen 
               
               
                 51.0% 
                 49.0% 
                 0.0% 
                 Frozen 
               
               
                 61.2% 
                 18.8% 
                 20.0% 
                 Frozen 
               
               
                 61.2% 
                 23.8% 
                 15.0% 
                 Slightly Viscous 
               
               
                   
                   
                   
                 Liquid 
               
               
                 61.2% 
                 28.8% 
                 10.0% 
                 Frozen 
               
               
                 61.2% 
                 33.8% 
                 5.0% 
                 Frozen 
               
               
                 61.2% 
                 38.8% 
                 0.0% 
                 Frozen 
               
               
                 65.0% 
                 25.0% 
                 10.0% 
                 Partially Frozen 
               
               
                 68.9% 
                 21.2% 
                 10.0% 
                 Viscous Liquid 
               
               
                 76.5% 
                 23.5% 
                 0.0% 
                 Frozen 
               
               
                   
               
            
           
         
       
     
     Example 4 
     To a glass sample vial was added commercial solution of bis[tetrakis(hydroxymethyl)phosphonium] sulfate solution, water and propylene glycol in an amount sufficient to produce a 20 g sample. The composition of each sample is shown below in Table 4. Each sample was then placed in a −40° C. freezer. The samples were observed after 24 hours and the physical form was noted in Table 4. Reexamination of the samples after several days revealed them to be unchanged from the original observation. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Propylene Glycol. 
               
            
           
           
               
               
               
               
            
               
                 THPS 
                 Water 
                 Propylene Glycol 
                 Condition 
               
               
                   
               
               
                     25% 
                     15% 
                     60% 
                 Very Viscous 
               
               
                     25% 
                     35% 
                     40% 
                 Slightly viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 25.5% 
                  7.8% 
                 66.7% 
                 Very viscous liquid 
               
               
                 25.5% 
                 24.5% 
                 50.0% 
                 Slightly viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 25.5% 
                 41.2% 
                 33.3% 
                 Frozen 
               
               
                 25.5% 
                 57.8% 
                 16.7% 
                 Frozen 
               
               
                 25.5% 
                 74.5% 
                  0.0% 
                 Frozen 
               
               
                     40% 
                     20% 
                     40% 
                 Very viscous liquid 
               
               
                     40% 
                     30% 
                     30% 
                 Frozen 
               
               
                     40% 
                     40% 
                     20% 
                 Frozen 
               
               
                 51.0% 
                 15.7% 
                 33.3% 
                 Very viscous liquid 
               
               
                 51.0% 
                 24.0% 
                 25.0% 
                 Slightly viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 51.0% 
                 32.3% 
                 16.7% 
                 Frozen 
               
               
                 51.0% 
                 40.7% 
                  8.3% 
                 Frozen 
               
               
                 51.0% 
                 49.0% 
                  0.0% 
                 Frozen 
               
               
                 61.2% 
                 18.8% 
                 20.0% 
                 Very viscous liquid 
               
               
                 61.2% 
                 23.8% 
                 15.0% 
                 Slightly viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 61.2% 
                 28.8% 
                 10.0% 
                 Frozen 
               
               
                 61.2% 
                 33.8% 
                  5.0% 
                 Frozen 
               
               
                 61.2% 
                 38.8% 
                  0.0% 
                 Frozen 
               
               
                 76.5% 
                 23.5% 
                  0.0% 
                 Frozen 
               
               
                   
               
            
           
         
       
     
     Example 5 
     To a glass sample vial was added commercial solution of bis[tetrakis(hydroxymethyl)phosphonium] sulfate solution, water and glycerine in an amount sufficient to produce a 20 g sample. The composition of each sample is shown below in table 2. Each sample was then placed in a −40° C. freezer. The samples were observed after 24 hours and the physical form was noted in table 1. Reexamination of the samples after several days revealed them to be unchanged from the original observation. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Glycerin. 
               
            
           
           
               
               
               
               
            
               
                 THPS 
                 Water 
                 Glycerine 
                 Condition 
               
               
                   
               
               
                 20% 
                 20% 
                 60% 
                 Very viscous liquid 
               
               
                 20% 
                 30% 
                 50% 
                 Slightly viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 20% 
                 40% 
                 40% 
                 Frozen 
               
               
                 30% 
                 15% 
                 55% 
                 Very viscous liquid 
               
               
                 30% 
                 25% 
                 45% 
                 Viscous liquid 
               
               
                 30% 
                 35% 
                 35% 
                 Frozen 
               
               
                 40% 
                 20% 
                 40% 
                 Viscous liquid 
               
               
                 45% 
                 15% 
                 40% 
                 Very Very viscous 
               
               
                   
                   
                   
                 liquid 
               
               
                 54% 
                 16% 
                 30% 
                 Very viscous liquid 
               
               
                 57% 
                 18% 
                 25% 
                 Very viscous liquid 
               
               
                 61% 
                 19% 
                 20% 
                 Viscous liquid