Additive composition for a metal working fluid

Abstract

An additive composition for a metalworking fluid which comprises a reaction product obtainable by the reaction between a molar excess of an anhydride and an amine, wherein the amine is at least one amino alkyl mono- or di- alkanolamine, in particular having a structural formula (I): HOOC—R—CO—NH—X—N(R′)—Y—O—CO—R′′—COOH, wherein: X represents an alkyl group having 1 to 12 carbon atoms, preferably, 2 to 8 carbon atoms and more preferably 3 to 6 carbon atoms; Y represents a hydrocarbyl group having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms; R′ represents an alkyl or alkanol groups having 2 to 12 carbon atoms; and R and R″ independently represent hydrocarbyl groups which have up to 48 carbon atoms, preferably 2 to 28; more preferably 6 to 13 carbon atoms.

We claim:  
     
         1 . An additive composition for a metalworking fluid, said additive composition comprising a reaction product obtainable by the reaction between a molar excess of an anhydride and an amine, wherein the amine is at least one amino alkyl mono- or di-alkanolamine.  
     
     
         2 . An additive composition as claimed in  claim 1  in which said anhydride comprises up to 50 carbon atoms, preferably 4 to 30 carbon atoms, more preferably 8 to 15 carbon atoms.  
     
     
         3 . An additive composition as claimed in  claim 1  or  claim 2  in which said anhydride is a polycarboxylic acid anhydride.  
     
     
         4 . An additive composition as claimed in  claim 3  in which said anhydride is a dicarboxylic acid anhydride.  
     
     
         5 . An additive composition as claimed in  claim 4  in which said anhydride is selected from the group consisting of succinic, phthalic, glutaric, pimelic, suberic, azelaic and sebacic anhydrides.  
     
     
         6 . An additive composition as claimed in any preceding claim in which said anhydrides further comprise aliphatic hydrocarbyl substituents.  
     
     
         7 . An additive composition as claimed in  claim 6  in which said substituents include C 1  to C 25 , preferably, C 4  to C 18 , more preferably, C 6  to C 12  alkyl and/or alkenyl groups, for example, a C 8  alkyl or alkenyl group.  
     
     
         8 . An additive composition as claimed in  claim 1  in which said anhydride is octenyl succinic anhydride.  
     
     
         9 . An additive composition as claimed in any preceding claim in which said amino alkyl di-alkanolamine preferably has an alkyl group of 1 to 12 carbon atoms, more preferably, 2 to 8 carbon atoms, and most preferably, 3 to 6 carbon atoms.  
     
     
         10 . An additive composition as claimed in any preceding claim in which the alkyl group of said amino alkyl dialkanolamine is selected from the group consisting of ethyl, propyl, butyl, pentyl and hexyl groups.  
     
     
         11 . An additive composition as claimed in any one of the preceding claims in which the amino alkyl di-alkanolamine has a di-alkanolamine group having 2 to 12 carbon atoms, preferably, 2 to 6 carbon atoms.  
     
     
         12 . An additive composition as claimed in  claim 11  in which the di-alkanolamine is derived from an unsubstituted and/or substituted diethanolamine, dipropanolamine, di-t-butanolamine, diisopropanolamine, 2,2′-iminbutanol, 3,3′-iminodipentanol-2, and/or N-(hydroxyethyl)-propanol amine.  
     
     
         13 . An additive composition as claimed in  claim 11  in which the di-alkylalkanolamine is aminopropyl di-iso-propanolamine (APDIPA).  
     
     
         14 . An additive composition as claimed in  claim 13  which comprises the reaction product of amino propyl di-iso-propanolamine and octenyl succinic anhydride, preferably in a mole ratio of amine to anhydride of 0.5:1.  
     
     
         15 . A compound having a structural formula (I):  
       HOOC—R—CO—NH—X—N(R′)—Y—O—CO—R″—COOH   (I).  wherein: 
 X represents an alkyl group having 1 to 12 carbon atoms, preferably, 2 to 8 carbon atoms and more preferably 3 to 6 carbon atoms;  
 Y represents a hydrocarbyl group having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms;  
 R′ represents an alkyl or alkanol group having 2 to 12 carbon atoms; and  
 R and R″ independently represent hydrocarbyl groups which have up to 48 carbon atoms, preferably 2 to 28, more preferably 6 to 13 carbon atoms.  
   
     
     
         16 . A compound as claimed in  claim 15  in which R and R″ independently comprise aliphatic hydrocarbyl substituents, preferably C 1  to C 25 , preferably, C 4  to C 18 , more preferably, C 6  to C 12  alkyl and/or alkenyl groups, for example, a C 8  alkyl or alkenyl group.  
     
     
         17 . A compound as claimed in  claim 15  in which R and R″ together with their associated COOH and CO groups are octenyl substituted succinate groups, X is an n-propyl group, Y is an isopropyl group and R′ is an isopropanol group.  
     
     
         18 . A process for preparing an additive composition as claimed in any one of  claims 1  to  14  or for preparing a compound as claimed in any one of  claims 15  to  17  which comprises reacting a molar excess of an anhydride and an amine, wherein the amine is at least one amino alkyl mono- or di- alkanolamine.  
     
     
         19 . A process as claimed in  claim 18  in which the mole ratio of amine to anhydride is in the range 0.1 to less than 1:1, preferably 0.2 to less than 1:1, more preferably 0.4 to less than 1:1 and most preferably 0.5:1.  
     
     
         20 . A process as claimed in  claim 18  or  19  in which the reaction is performed at a temperature of 80 to 200° C., preferably, 100 to 180° C., more preferably, 130 to 160° C.  
     
     
         21 . An additive composition as claimed in any one of  claims 1  to  14  which further comprises water and at least one lubricity additive selected from the group consisting of polyalkylene oxides, phosphate esters, fatty acids, fatty acid esters and derivatives thereof.  
     
     
         22 . A metalworking fluid comprising an additive composition as claimed in any one of  claims 1  to  14  or  21 , or as prepared by a process as claimed in any one of  claims 18  to  20  or comprising a compound as claimed in any one of  claims 15  to  17 .  
     
     
         23 . A metalworking fluid as claimed in  claim 22  comprising 1 to 50 wt % of a reaction product of a process as claimed in any one of  claims 18  to  20 .  
     
     
         24 . A metalworking fluid as claimed in  claim 22  or  claim 23  further comprising at least one lubricity additive selected from the group consisting of polyalkylene oxides, phosphate esters, fatty acids, fatty acid esters and derivatives thereof.  
     
     
         25 . A metalworking fluid as claimed in  claim 24  which comprises by weight: water, 40-90%; Reaction Product, 2-50%; C 6 -C 12  Fatty acids/potassium salts, 5-15%; benzotriazole, 0-5%; defoamer, 0-1% and biocides, 0-1%.  
     
     
         26 . A method of metalworking which comprises employing a metalworking fluid as claimed in any one of  claims 22  to  25 .  
     
     
         27 . Use of an additive composition as claimed in any one of  claims 1  to  14  or  21 , or as prepared by a process as claimed in any one of  claims 18  to  20  or comprising a compound as claimed in any one of claims  15  or  17  as a corrosion inhibitor for a metalworking fluid.