N-vinyl lactam interpolymers useful as thickening agents
This is a division of application Ser. No. 190,653, filed Oct. 19, 1971, and now abandoned, which application was a continuation-in-part of application Ser. No. 7,241, filed on Jan. 30, 1970, and now also abandoned. 
    
    
     The instant invention is directed to novel interpolymers which are useful as thickening agents in aqueous acid mediums. In particular, the instant invention is directed to interpolymers comprising N-vinyllactam or acrylamide, long-chain containing vinyl monomer units, and a cationic moiety. 
     The novel interpolymer compositions of the instant invention are of the type 
     
         A / B / C 
    
     which have been found to be extremely useful as thickeners in aqueous systems and particularly useful in aqueous acidic mediums. 
     Component A of the subject interpolymer is derived from approximately 20.0 to approximately 99 mole % of either acrylamide or an N-vinyllactam having the following general configuration: ##EQU2## wherein R 1  and R 2  are each selected from the group consisting of hydrogen, and alkyl containing 1 to 2 carbon atoms, and Y is selected from the group consisting of oxygen, sulfur, sulfur dioxide, &lt;NR 1 , and ##EQU3## wherein not more than two of the groups R 1  and R 2  are alkyl groups. n and n 1  may range from 0 to about 5 but only one of said n or n 1  may be 0. Lactams of this type include materials such as the N-vinyl-2-pyrrolidone disclosed in U.S. Pat. Nos. 2,265,450; 2,335,454; and 3,097,087 the disclosures of which are incorporated herein by reference. 
     Further compounds which are useful as the N-vinyllactam component of the subject interpolymer compositions are those which may be prepared according to known processes by N-vinylation of the corresponding lactam at elevated temperatures. A process of this type is disclosed in U.S. Pat. No. 2,317,084 the disclosure of which is incorporated herein by reference. Exemplary of such compounds are the N-vinyl substituted derivatives of the following lactam: 
     3,3-dimethyl-2-pyrrolidone 
     4,4-dimethyl-2-pyrrolidone 
     3-ethyl-2-pyrrolidone 
     3,5-dimethyl-3-pyrrolidone 
     4-ethyl-2-pyrrolidone 
     5-ethyl-2-pyrrolidone 
     3-methyl-2-pyrrolidone 
     4-methyl-2-pyrrolidone 
     5-methyl-2-pyrrolidone 
     3,3,5-trimethyl-2-pyrrolidone 
     2-piperidone 
     5,6-dimethyl-2-piperidone 
     4-ethyl-2-piperidone 
     6-ethyl-2-piperidone 
     6-ethyl-3-methyl-2-piperidone 
     3-methyl-2-piperidone 
     4-methyl-2-piperidone 
      5methyl-2-piperidone 
     6-methyl-2-piperidone 
     6-methyl-2-piperidone 
     2-caprolactam 
     3,6-dimethyl-2-caprolactam 
     4,6-dimethyl-2-caprolactam 
     4,7-dimethyl-2-caprolactam 
     7,7-diethyl-2-caprolactam 
     3-ethyl-2-caprolactam 
     5-ethyl-2-caprolactam 
     6-ethyl-2-caprolactam 
     7-ethyl-2-caprolactam 
     4-ethyl-6-methyl-2-caprolactam 
     6-methyl-2-caprolactam 
     6-ethyl-4-methyl-2-caprolactam 
     3-methyl-2-caprolactam 
     4-methyl-2-caprolactam 
     5-methyl-2-caprolactam 
     6-methyl-2-caprolactam 
     2-oxazinidinone 
     5-ethyl-2-oxazinidinone 
     4,5-dimethyl-2-oxazinidinone 
     5,5-dimethyl-2-oxazinidinone 
     2,2&#39;-dimethyl-4-oxothiazolidone 
     2-oxazolidinone 
     5-methyl-2-oxazolidinone 
     4-methyl-2-oxazolidinone 
     5-ethyl-2-oxazolidinone 
     4,5-dimethyl-2-oxazolidinone 
     3-morpholinone 
     5-methyl-3-morpholinone 
     5-ethyl-3-morpholinone 
     2-piperazonone 
     3,3-dimethyl-2-ketopiperazine 
     3-methyl-2-ketopiperazine 
     4-thiazolidone 
     2-methyl-4-thiazolidinone 
     2-thiazolidone 
     3-thiomorpholinone 
     2-pyrimidone 
     2-imidazolidones 
     It is, of course, understood that mixtures of any of the above or similar N-vinylated lactams may be employed in combination or alone in the interpolymers of the instant invention. Preferably, however, N-vinyl-2-pyrrolidone is employed as the lactam component of the instant composition and will be referred to hereinafter as vinyl pyrrolidone. 
     The interpolymers may contain a minor amount, e.g., 1-5 mole % of part of the lactam. In place of the acrylonitrile, the various substituted acrylonitriles (e.g. methacrylonitrile, ethacrylonitrile, etc.) may be suitably used. 
     The second component of the subject interpolymer composition is a long-chain containing vinyl monomer unit derived from a vinyl monomer represented by the formula: ##EQU4## wherein 
     Z represents hydrogen, halogen, lower alkyl or phenyl; 
     X represents a simple chemical bond, oxygen, sulfur, carboxy, or carbonamido; and 
     R represents the same or different hydrocarbon groups containing from about 6 to about 36 carbon atoms. 
     The hydrocarbon groups may be selected from normal-chain alkyl, branched-chain alkyl, cycloalkyl and alkylaryl. 
     It is to be noted that the preferred embodiments of the instant invention encompass those interpolymers wherein this particular moiety has as the R group a hydrocarbon group having 6 to 20 carbon atoms. It is further noted that the alkyl substituted moieties are preferred over the alkylaryl substituted ones, however, the alkyl aryl substituted units results in attaining highly satisfactory products. This particular component of the interpolymer is present in amounts of from about 0.5 to about 10 mole %. 
     As exemplary of those compounds employed as the second component of the novel interpolymers of the instant invention, there may be mentioned: 
     hexyl vinyl ether 
     heptyl vinyl ether 
     octyl vinyl ether 
     nonyl vinyl ether 
     decyl vinyl ether 
     hendecyl vinyl ether 
     dodecyl vinyl ether 
     tetradecyl vinyl ether 
     hexadecyl vinyl ether 
     octadecyl vinyl ether 
     myricyl vinyl ether 
     docosyl vinyl ether 
     cetyl vinyl ether 
     2-ethyl-1-butyl vinyl ether 
     2,6-dimethyl-4-heptyl vinyl ether 
     2,4,6,8-tetramethyl-1-nonyl vinyl ether 
     2-ethyl-1-decyl vinyl ether 
     isooctyl vinyl ether 
     2-ethylhexyl vinyl ether 
     isodecyl vinyl ether 
     tridecyl vinyl ether 
     cyclohexyl vinyl ether 
     decahydronaphthyl vinyl ether 
     hydroabietinyl vinyl ether 
     terpinyl vinyl ether 
     benzyl vinyl ether 
     β-phenylethyl vinyl ether 
     hydrocinnamyl vinyl ether 
     undecyl acrylate 
     lauryl acrylate 
     tridecyl acrylate 
     cetyl acrylate 
     octadecyl acrylate 
     myricyl acrylate 
     decyl acrylate 
     dodecylmethacrylate 
     cetyl methacrylate 
     octadecyl methacrylate 
     decyl α-ethyl acrylate 
     dodecyl-α-ethyl acrylate 
     tetradecyl α-ethyl acrylate 
     hexadecyl-α -ethyl acrylate 
     dodecyl α-chloroacrylate 
     tetradecyl-α-chloroacrylate 
     octadecyl-α-chloroacrylate 
     octadecyl α-bromoacrylate 
     hexyl α-phenyl acrylate 
     octyl α-phenyl acrylate 
     nonyl α-phenyl acrylate 
     decyl α-phenyl acrylate 
     dodecyl α-phenyl acrylate 
     decene-1 
     dodecene-1 
     hexadecene-1 
     octadecene-1 
     eicosene-1 
     vinyl laurate 
     vinyl palmitate 
     vinyl oleate 
     vinyl stearate 
     N-hexyl acrylamide 
     N-cetyl acrylamide 
     N-octadecyl acrylamide 
     N,n-dioctadecyl acrylamide 
     N-decyl methacrylamide 
     N,n-dioctyl methacrylamide 
     vinyl hexyl sulfide 
     vinyl dodecyl sulfide 
     vinyl tetradecyl sulfide 
     vinyl hexadecyl sulfide 
     vinyl octadecyl sulfide 
     N-vinyl-N-methyl lauramide 
     N-vinyl-N-ethyl myristamide 
     N-vinyl-N-methyl palmitamide 
     N-vinyl-N-methyl stearamide 
     N-vinyl-N-methyl oleamide 
     tetradecyl isopropenyl ether 
     hexadecyl isopropenyl ether 
     octadecyl isopropenyl ether 
     myricyl isopropenyl ether 
     It is, of course, understood that the above-noted compounds may be employed either alone or in combination in the interpolymers of the instant invention. 
     The third component of the interpolymers of the instant invention, i.e., Component C, is a cationic moiety or its precursor derived from various monomers. This moiety is present in the interpolymer in amounts of from about 0.5 to about 79.5 mole %. The useful cationic moieties include compounds having the formula: ##EQU5## wherein R 4  and R 5  each designate a hydrocarbon group having 1 to 4 carbon atoms and when taken together with the nitrogen atom to which they are attached, a ring of not more than 6 carbon atoms, R 6  represents a hydrocarbon group having 2 to 4 carbon atoms; and/or 
     
         CH.sub.2 = CHOCH.sub.2 CH.sub.2 N.sup.+(CH.sub.3).sub.3 X.sup.-(2) 
    
     wherein X represents halogen such as chlorine, bromine, or iodine; and/or ##EQU6## wherein R 7 , R 8  and R 9  each designate methyl, ethyl or hydroxyethyl, R 10  is hydrogen or methyl, and X is halogen. 
     The novel interpolymers of the instant invention should have a relative viscosity of from 2 to about 30 as a 1% weight to volume solution in methanol. Preferably the interpolymers have a relative viscosity of 3 or above. The novel interpolymer composition of the instant invention as previously noted is extremely useful in the thickening of aqueous mediums. Such mediums include water, water-alcohol mixtures, aqueous acids and latices. The interpolymer of choice for a particular purpose may be selected depending upon its molecular weight as defined by its relative viscosity, the hydrophobic nature of the interpolymer as determined by the ratio and length of the long-chain moieties and other factors as will be evident to one skilled in the art. 
     The instant invention will now be further explained by the following more detailed examples thereof. It is to be noted, however, that the instant invention is not deemed as being limited thereby. 
    
    
     EXAMPLE 1 
     The following solutions were prepared: 
     Solution A 
     (50% wt./vol. vinylpyrrolidone) 
     125.0 g. distilled vinylpyrrolidone made up to a total of 
     250.0 mls. with C.P. methanol in a volumetric flask 
     Solution B 
     (50% wt./vol. dimethylaminoethyl vinyl ether) 
     25.0 g. distilled dimethylaminoethyl vinyl ether made up to total of 
     50.0 mls. with C.P. methanol in a volumetric flask 
     Solution C 
     (5% wt./vol. catalyst solution) 
     1.250 g. Azobisisobutyronitrile made up to total of 
     25.0 mls. with C.P. methanol in a volumetric flask 
     Polymerization tubes of approximately 100 ml. capacity with 8 inch extensions of 8 mm. tube were charged as follows: 
     
                                           TABLE 1                                 
__________________________________________________________________________
           Tube 1  2       3       4       5                              
__________________________________________________________________________
Solution A 50 mls. 45.0 mls.                                              
                           44.0 mls.                                      
                                   42.5 mls.                              
                                           40.0 mls.                      
Solution B none     1.0 ml.                                               
                            1.0 ml.                                       
                                    2.5 ml.                               
                                            2.5 mls.                      
Solution C  0.5 ml.                                                       
                    0.5 ml.                                               
                            0.5 ml.                                       
                                    0.5 ml.                               
                                            0.5 ml.                       
Vinyl ether.sup.3                                                         
           none     2.0 g.  2.5 g.  2.5 g.  3.75 g.                       
Composition (mole % of                                                    
 Charge    PVP.sup.1 Control                                              
                   94.7 VP.sup.2                                          
                           93.7 VP 90.6 VP 88.1 VP                        
                   3.3 VE.sup.3 1618                                      
                           4.3 VE 1618                                    
                                   4.3 VE 1618                            
                                           6.6 VE 1618                    
                   2.0 DMAEVE.sup.4                                       
                           2.0 DMAEVE                                     
                                   5.1 DMAEVE                             
                                           5.3 DMAEVE                     
__________________________________________________________________________
 .sup.1 PVP - polyvinylpyrrolidone                                        
 .sup.2 VP - vinylpyrrolidone                                             
 .sup.3 VE - vinyl ether (2/3 n-hexadecyl vinyl ether and 1/3 n-octadecyl 
 vinyl ether)                                                             
 .sup.4 DMAEVE - dimethylaminoethyl vinyl ether                           
 
    
     The tubes were cooled to -75°C, evacuated by means of a vacuum pump to 20 mm., thawed and released with nitrogen then cooled to -75°C and evacuated to 20 mm. and sealed off. After thawing the tube contents to room temperature and shaking, the tubes were placed in a 65°C constant temperature bath for 19 hours. 
     The viscous products were each dissolved in 100 mls. C.P. methanol and the polymers precipitated by adding each to a mixture of 200 mls. heptane and 300 mls. diethyl ether. 
     The polymers were then dried in a vacuum oven at 40° to 45°C. and the weight, relative viscosity and equivalence/gram amine determined. The results are set forth in Table 2 below. 
     
                       TABLE 2                                                     
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Tube    Relative    Dried      Equivalence.sup.2 /                        
        Viscosity.sup.1                                                   
                    Weight     gram amine                                 
______________________________________                                    
1       4.216       24.6       none                                       
2       4.065       22.2       .00009                                     
3       4.029       22.2       .00009                                     
4       3.642       22.1       .00015                                     
5       3.440       20.7       .00015                                     
______________________________________                                    
 .sup.1 1% in methanol                                                    
 .sup.2 By titration                                                      
 
    
     EXAMPLE 2 
     The following solutions were prepared: 
     Solution A: 
     50% wt./vol. 92 parts vinylpyrrolidone, 8 parts vinyl 
     ether 1  comprising 
     92 grams distilled vinylpyrrolidone 
     8.0 grams vinyl ether 3   
     0.1 gram azobisisobutyronitrile made up to a total of 
     200 mls. with C.P. methanol in a volumetric flask 
     Solution B: 
     50% wt./vol. 90 parts vinylpyrrolidone, 4 parts vinyl 
     ether 1  and 6 parts 2-hydroxy-3-methacrylyloxypropyltrimethylammonium 
     chloride 
     90.0 grams distilled vinylpyrrolidone 
     4.0 grams vinyl ether 1   
     6.5 grams (91.8%) or (6.0 grams 100%) 2-hydroxy-3methacrylyloxypropyltrimethylammonium 
     chloride 
     0.1 gram azobisisobutyronitrile made up to a total of 
     200 mls. with C.P. methanol in a volumetric flask  1  Vinyl ether ( 2/3 n-hexadecyl vinyl ether and 1/3n-octadecyl vinyl ether) 
     Polymerization tubes of approximately 100 ml. capacity with 8 inch extensions of 8 mm. tube were charged as follows: 
     
                                           TABLE 3                                 
__________________________________________________________________________
Tube        1     2     3     4     5                                     
__________________________________________________________________________
Solution A 70 ml.                                                         
                 52.5  35.0  17.5  none                                   
Solution B none  17.5  35.0  52.5  70 ml.                                 
Composition (mole %)                                                      
           99.2 VP.sup.1                                                  
                 96.4 VP                                                  
                       96.0 VP                                            
                             95.7 VP                                      
                                   95.4 VP                                
 of Charge  0.8 VE.sup.2                                                  
                  2.9 VE                                                  
                        2.6 VE                                            
                              2.1 VE                                      
                                    1.6 VE                                
                  0.7 MA                                                  
                        1.4 MA                                            
                              2.2 MA                                      
                                    3.0 MA                                
__________________________________________________________________________
 .sup.1 VP -vinyl pyrrolidone                                             
 .sup.2 VE -                                                              
 .sup.3 MA - 2-hydroxy-3-methacrylyloxypropyltrimethylammonium chloride   
 
    
     The tubes were cooled to -75°C, evacuated by means of a vacuum pump to 20 mm. and released with nitrogen. This procedure was repeated two more times then the tubes were evacuated and sealed. After thawing and shaking the tubes were heated in a 65°C constant temperature bath for 18 hours. 
     The viscous products were each dissolved in 130 mls. C. methanol and precipitated by addition to 1 liter of diethyl ether. 
     The polymers were dried in a vacuum oven and analyzed with the following results: 
     
                       TABLE 4                                                     
______________________________________                                    
Tube    Relative    Dried      Equivalence.sup.2 /                        
        Viscosity.sup.1                                                   
                    Weight     gram amine                                 
______________________________________                                    
1        3.498      32.1 g.      none (control)                           
2        6.583      34.3 g.      .00004                                   
3        9.715      33.5 g.      .00005                                   
4       12.661      34.0 g.      .00005                                   
5       16.464      34.5 g.      .00017                                   
______________________________________                                    
 .sup.1 1% in methanol                                                    
 .sup.2 By titration                                                      
 
    
     EXAMPLE 3 
     Solutions of the subject interpolymers in 15% HCl were found to have the following viscosities as determined with a Brookfield Model LVF viscometer. 
     
                                           TABLE 5                                 
__________________________________________________________________________
                                   Rel. Visc.                             
                                           Polymer                        
                                                CPS                       
         Interpolymer              1% MeOH Conc.                          
                                                6 rpm.                    
__________________________________________________________________________
PVP.sup.1 Control (Example 1-No. 1)                                       
                                   4.21   4%   70                         
PVP Control (Example 1-No. 1)      4.21   2%   40                         
94.7 mole % VP.sup.2 /3.3 mole % VE.sup.3 /2.0 mole % DMAEVE.sup.4        
(Example 1-No.2)                   4.06   4%   46,000                     
94.7 mole % VP/ 3.3 mole % VE/ 2.0 mole % DMAEVE (Example 1-No.           
                                   4.06   3%   31,000                     
94.7 mole % VP/ 3.3 mole % VE/ 2.0 mole % DMAEVE (Example 1-No.           
                                   4.06   2%   8,500                      
93.7 mole % VP/ 4.3 mole % VE/ 2.0 mole % DMAEVE (Example 1-No.           
                                   4.02   4%   83,500                     
93.7 mole % VP/ 4.3 mole % VE/ 2.0 mole % DMAEVE (Example 1-No.           
                                   4.02   3%   50,000                     
93.7 mole % VP/ 4.3 mole % VE/ 2.0 mole % DMAEVE(Example 1-No.            
                                   4.02   2%   8,000                      
90.6 mole % VP/ 4.3 mole % VE/ 5.1 mole % DMAEVE (Example 1-No.           
                                   3.64   4%   18,500                     
90.6 mole % VP/ 4.3 mole % VE/ 5.1 mole % DMAEVE (Example 1-No.           
                                   3.64   3%   12,500                     
90.6 mole % VP/ 4.3 mole % VE/ 5.1 mole % DMAEVE (Example 1-No.           
                                   3.64   2%   7,900                      
88.1 mole % VP/ 6.6 mole % VE/ 5.3 mole % DMAEVE (Example 1-No.           
                                   3.44   4%   55,600                     
88.1 mole % VP/ 6.6 mole % VE/ 5.3 mole % DMAEVE (example 1-No.           
                                   3.44   3%   20,000                     
88.1 mole % VP/ 6.6 mole % VE/ 5.3 mole % DMAEVE (Example 1-No.           
                                   3.44   2%   9,500                      
93.4 mole % VP/ 6.6 mole % VE Control                                     
                                   3.58   2%   6,100                      
90.9 mole % VP/ 9.1 mole % VE Control                                     
                                   3.45   2%   7,100                      
99.2 mole % VP/ 0.8 % VE (Example 2-No. 1)                                
                                   3.49   2%   5,300                      
96.4 mole % VP/ 2.9 mole % VE/ 0.7 mole % G-MAC.sup.5 (Example 2-No.      
                                   6.58   2%   11,400                     
96.0 mole % VP/ 2.6 mole % VE/ 1.4 mole % G-MAC (Example 2-No.            
                                   9.71   2%   10,450                     
95.7 mole % VP/ 2.1 mole % VE/ 2.2 mole % G-MAC (Example 2-No.            
                                   12.66  2%   8,500                      
95.4 mole % VP/ 1.6 mole % VE/ 3.0 mole % G-MAC (Example 2-No.            
                                   16.46  2%   11,000                     
49.5 mole %    49.5 mole %     1.0 mole %                                 
__________________________________________________________________________
 .sup.1 PVP - polyvinyl pyrrolidone                                       
 .sup.2 VP - vinyl pyrrolidone                                            
 .sup.3 VE - vinyl ether (2/3 n-hexadecyl vinyl ether and 1/3 n-octadecyl 
 vinyl ether)                                                             
 .sup.4 DMAEVE - dimethylaminoethyl vinyl                                 
 .sup.5 G-MAC - 2-hydroxy-3-methacrylyloxypropyltrimethylamino chloride