Dispersions of acrylic polymer latex as additives for the inhibition of the deposition of paraffins in crude oils and compositions that contain them

Abstract

This invention relates to latex dispersions that are based on (co)polymers with one or more n-alkyl (meth)acrylate monomers with n a varying from 6 to 40, and optionally one or more monomers that are not very water-soluble of the (meth)acrylic and/or vinyl type, optionally one or more polar monomers that are selected from among the (meth)acrylamides and their derivatives and optionally one or more monomers that are selected from among the ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides. These dispersions are obtained by radical-type emulsion polymerization in the presence of water. They can be used as is for the inhibition of the deposition of paraffins that are contained in the crude petroleum hydrocarbons or else diluted in one or more solvents.

1 . A latex dispersion, comprising: 
 (1) 5 to 70, parts by weight of one or more (co)polymers, whose units come from:    A—50 to 100%, by weight of one or more monomers of n-alkyl (meth)acrylate, with n separating the number of carbon atoms in the alkyl and being 6 to 40,    B—0 to 50%, by weight of one or more (meth)acrylic or vinyl monomers having a water solubility of less than 5% at 20° C. selected from n-alkyl (meth)acrylates with n less than or equal to 6, 2-ethyl hexyl (meth)acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatates, vinyl pivalate, vinyl laurate, and styrenes,    C—0 to 50%, by weight of one or more polar monomers that are selected from (meth)acrylamides and their derivatives, N-methylolacrylamide, dialkylaminoethyl (meth)acrylates, the monoolefinic derivatives of sulfonic acid and phosphoric acid, acrylamidomethyl propane sulfonic acid, N-vinylpyrrolidone, vinylpyridine and its derivatives, and hydroxyalkyl (meth)acrylates,    D—either 0 to 0.5% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C=0%,    - or up to 40% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C≠0%.    (2) 0 to 30 parts by weight of a co-solvent or a mixture of co-solvents, parts by weight, selected ketones. methylethylketone or methylisobutylketone, aromatic solvents toluene, xylene and mixtures of aromatic hydrocarbons, alcohols butanol or isopropanol, glycols and polyglycol ethers ethylene or propylene glycol, diethylene glycol or dipropylene glycol,    
       (3) 0.1 to 10, parts by weight of one or more surfactants (ionic surfactants and/or nonionic surfactants and/or protective colloids such as polyvinyl alcohols and/or amphiphilic polymers that are selected from sulfates or sulfonates of fatty alcohols or alkylphenol, alkylbenzene sulfonates and sulfosuccinates, quaternary ammonium salts dimethyldialkylammonium chlorides and ethoxylated fatty alcohols).  
       (4) water (sufficient quantity for 100),  
       and optionally other components, comprising initiating agents, buffering agents, transfer agents and surfactants with a low hydrophilic-lipophilic balance.  
     
     
         2 . A latex dispersion according to  claim 1 , comprising as co-solvent(s) one or more liquid polyols, for which the amount of water represents more than 40% of the weight of solid polyol(s).  
     
     
         3 . A later dispersion according to  claim 1  comprising: 
 (1) about 30 to about 35 parts by weight of said (co)polymer(s),    (2) about 14 to about 18 parts by weight of said co-solvent or mixture of co-solvents,    (3) about 1 to about 4 parts by weight of said surfactants,    (4) the addition to 100 parts by weight of water, and at least one initiating agent, at least one transfer agent, and at least one buffering agent.    
     
     
         4 . A process for preparation of latex dispersions as defined in by  claim 1  comprising conducting radical-type emulsion polymerization in water of the monomers in the presence of surfactant(s) and optionally in the presence of one or more co-solvents.  
     
     
         5 . A process according to  claim 4 , wherein the radical-type initiating agents are selected from peroxides, persulfates, organic hydroperoxides and peroxides, hydrogen peroxide, peracids, diazo compounds, 4,4′ azobis(4-cyanopentanoic) acid, or 2,2-azobis(2-amidinopropane) hydrochloride or redox systems, or ammonium persulfate combined with sodium metabisulfite.  
     
     
         6 . A process according to  claim 4 , wherein the polymerization reaction is conducted over a range of temperatures of from 20 to 90° C., preferably for a period from 0.5 to 4 hours.  
     
     
         7 . A process according to  claim 4 , wherein the polymerization is performed in the presence of at least one buffering agent and/or at least one transfer agent.  
     
     
         8 . A process according to  claim 4 , comprising a post-addition of organic solvent(s), and/or surfactant(s), having an HLB that is less than or equal to 5.  
     
     
         9 . A process comprising adding to crude petroleum a latex dispersion as defined in  claim 1  to inhibit the deposition of paraffins in the crude petroleum  
     
     
         10 . A process according to  claim 9 , wherein said adding comprises direct addition in the crude oil, or in the form of dilute compositions that contain said dispersions and one or more solvents such as water and/or one or more organic solvents or latex co-solvents.  
     
     
         11 . A crude petroleum comprising a sufficient amount of a latex dispersion according to  claim 1 , to inhibit deposition of paraffins.  
     
     
         12 . A latex dispersion according to  claim 1  comprising B, C or D.  
     
     
         13 . A latex dispersion according to  claim 1 , wherein the A monomers comprise benenyl acrylates.  
     
     
         14 . A latex dispersion according to  claim 3 , wherein the A monomers comprise benenyl acrylates.  
     
     
         15 . A latex dispersion according to  claim 11 , comprising 5-25 parts by weight of said co-solvent or mixture of co-solvents.  
     
     
         16 . A latex dispersion according to  claim 15 , wherein said co-solvent or mixture of co-solvents comprises monomethyl ethers of dipropylene glycol.  
     
     
         17 . A latex dispersion according to  claim 15 , wherein said co-solvent or mixture of co-solvents comprise N-vinyl pyrrolidone.  
     
     
         18 . A latex dispersion according to  claim 1 , wherein said dispersion comprises: 
 (1) 5 to 58 parts by weight of one or more (co)polymers, whose units come from:    A—70 to 100% by weight of one or more monomers of n-alkyl (meth)acrylate with n being 14 to 30,    B—0 to 30% by weight of said one or more (meth)acrylic or vinyl monomers,    C—0 to 30% by weight of said one or more polar monomers,    D—either 0 to 0.5% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C=0%,    - or up to 40% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C≠0%.    (2) 5 to 25 parts by weight of said co-solvent or said mixture of co-solvents,    (3) 0.1 to 8 parts by weight of said one or more surfactants.    (4) water (sufficient quantity for 100),    and optionally other components comprising initiating agents, buffering agents, transfer agents and surfactants with a low hydrophilic-lipophilic balance.    
     
     
         19 . : A latex dispersion according to  claim 1 , wherein said dispersion comprises: 
 (1) 5 to 50 parts by weight of one or more (co)polymers, whose units come from:    A—70 to 100% by weight of one or more monomers of n-alkyl (meth)acrylate with n being 14 to 30,    B—0 to 30% by weight of said one or more (meth)acrylic or vinyl monomers,    C—0 to 30% by weight of said one or more polar monomers,    D—either 0 to 0.5% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C=0%,    - or up to 40% by weight of one or more monomers that are selected from ethylenically unsaturated monocarboxylic and/or dicarboxylic acids or anhydrides when C≠0%.    (2) 5 to 20 parts by weight of said co-solvent or said mixture of co-solvents,    (3) 0.5 to 5 parts by weight of said one or more surfactants.    (4) water (sufficient quantity for 100),    and optionally other components comprising initiating agents, buffering agents, transfer agents and surfactants with a low hydrophilic-lipophilic balance.    
     
     
         20 . A latex dispersion according to  claim 1 , wherein said one or more (meth)acrylic or vinyl monomers having a water solubility of less than 5% at 20° C. are selected from n-alkyl (meth)acrylates with n less than or equal to 6, 2-ethyl hexyl (meth)acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl versatates, vinyl pivalate, vinyl laurate, and ρ-methyl styrene.  
     
     
         21 . A latex dispersion according to  claim 1 , wherein of said co-solvent or mixture of co-solvents are selected from methylethylketone, methylisobutylketone, toluene, xylene, butanoyl, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and monomethyl or ethyl propylene or dipropylene glycol.  
     
     
         22 . A latex dispersion according to  claim 1 , comprising as co-solvents(s) one or more liquid polyols, for which the amount of water represents more than 50% of the weight of solid polyol(s).  
     
     
         23 . A process according to  claim 6 , wherein the polymerization reaction is conducted for a period from 0.5 to 4 hours.  
     
     
         24 . A process according to  claim 7 , wherein said at least one buffering as agent is sodium tetraborate and/or said at least one transfer agent is an alkyl mercaptan.  
     
     
         25 . A process according to  claim 8 , wherein said organic solvent(s), and/or surfactant(s) having an HLB that is less than or equal to 5 is a fatty sorbitan esters.