Ethylene Diphosphinic Acids

Abstract

The invention relates to ethylene diphosphinic acids and salts thereof of general formula A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A, in which A, H and/or CR 5 R 6 —OH, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are the same or different, and denote independently from each other H, C 1 -C 20 alkyl, C 6 -C 20 aryl and or C 6 -C 20 aralkyl, and X denotes H, an alkali metal, an element of the second main and secondary group, an element of the third main and secondary group, an element of the fourth main and secondary group, an element of the fifth main and secondary group, an element of the sixth secondary group, an element of the seventh secondary group, an element of the eight secondary group and/or a nitrogen base. Also disclosed are a method for producing same and the use thereof.

1 . An ethylenediphosphinic acid or salt thereof having the formula (I)
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A  (I)
   where A is H and/or CR 5 R 6 —OH,   R 1 , R 2 , R 3 , R 4 , R 5 , R 6  are identical or different and are each, independently of one another, H, C 1 -C 20 -alkyl, C 6 -C 20 -aryl or C 6 -C 20 -aralkyl and   X is H, an alkali metal, an element of main or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8 and/or a nitrogen base.   
     
     
         2 . An ethylenediphosphinic acid or salt thereof as claimed in  claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6  are identical or different and are each, independently of one another, H, methyl, ethyl, n-propyl, i-propyl, n-butyl, tert-butyl, n-pentyl or phenyl. 
     
     
         3 . An ethylenediphosphinic acid or salt thereof as claimed in one or more of  claims 1  to  3 , wherein A is H and X is Li, Na, K; Mg, Ca, Zn, Sr; Al, Ce, La; Ge, Sn, Pb, Ti, Zr; Sb, Bi; Cr, Mo, W; Mn; Fe, Co or Ni. 
     
     
         4 . An ethylenediphosphinic acid or salt thereof as claimed in one or more of  claims 1  to  4 , wherein A is H and X is H, Na, Al, Zn, Ca, Mg, Ti or melamine. 
     
     
         5 . A process (1) for preparing ethylenediphosphinic acids and salts thereof having the formula (I)
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A  (I)
   where A is H and/or CR 5 R 6 —OH,   R 1 , R 2 , R 3 , R 4 , R 5 , R 6  are identical or different and are each, independently of one another, H, C 1 -C 20 -alkyl, C 6 -C 20 -aryl or C 6 -C 20 -aralkyl and   X is H or an alkali metal, wherein   a) a monophosphinic acid adduct of the formula (II)
   H—P(O)(OX)-A  (II)
 
    is reacted with acetylene and   b) if desired, the resulting ethylenediphosphinic acid of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
 
    is separated off from by-products.   
     
     
         6 . A process (2) for preparing ethylenebis(hydroxyalkylphosphinic acid) salts or ethylenediphosphinic acid salts of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
   
       where A, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and X is an alkali metal, an element of main group or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8 and/or a nitrogen base, wherein an ethylenebis(hydroxyalkylphosphinic acid) or ethylenediphosphinic acid of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
 
 
       where A, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and X is H, is reacted in a solvent system with a reactant I which is a compound of an alkali metal, of an element of main or transition group 2, of an element of main or transition group 3, of an element, of main or transition group 4, of an element of main or transition group 5, of an element of transition group 6, of an element of transition group 7, of an element of transition group 8 and/or a nitrogen base. 
     
     
         7 . A process (3) for preparing ethylenebis(hydroxyalkylphosphinic acid) salts or ethylenediphosphinic acid salts of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
   
       where A, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and X is an element of main group or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8 and/or a nitrogen base, wherein ethylenebis(hydroxyalkylphosphinic acid) or ethylenediphosphinic acid of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
 
 
       where A, R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and X is an alkali metal, is reacted in a solvent system with a reactant II to form another metal salt (not an alkali metal salt). 
     
     
         8 . The process as claimed in  claim 7 , wherein the reactant II is a borate, carbonate, hydroxocarbonate, hydroxocarbonate hydrate, mixed hydroxocarbonate, mixed hydroxocarbonate hydrate, phosphate, sulfate, sulfiate hydrate, hydroxosulfate hydrate, mixed hydroxosulfate hydrate, oxysulfate, acetate, nitrate, fluoride, fluoride hydrate, chloride, chloride hydrate, oxychloride, bromide, iodide, iodide hydrate, carboxylic acid derivative and/or alkoxide. 
     
     
         9 . A process (4) for preparing ethylenediphosphinic acid salts of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
   
       where R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and A is H and X is H, an alkali metal, an element of main or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8 and/or a nitrogen base, wherein an ethylenebis(hydroxyalkylphosphinic acid) of the type
   A-P(O)(OX)—CR 1 R 2 —CR 3 R 4 —P(O)(OX)-A
 
 
       where R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are as defined in  claim 1  and A is CR 6 R 6 —OH and X is H, an alkali metal, an element of main or transition group 2, an element of main or transition group 3, an element of main or transition group 4, an element of main or transition group 5, an element of transition group 6, an element of transition group 7, an element of transition group 8 and/or a nitrogen base, is heated. 
     
     
         10 . The process as claimed in  claim 9 , wherein heating is carried out at from 20 to 300° C., preferably from 50 to 200° C. 
     
     
         11 . The process as claimed in  claim 9  or  10 , Wherein heating is carried out in the presence of a protic acid which is a mineral acid (hydrochloric acid, sulfuric acid, phosphoric acid), carboxylic acid (formic acid, acetic acid, polymeric carboxylic acid), sulfonic acid, phosphonic acid, organically crosslinked carboxylic, sulfonic, phosphonic acid or a mixture thereof. 
     
     
         12 . The use of ethylenediphosphinic acids as claimed in at least one of  claims 1  to  5  as flame retardants, in particular flame retardants for clear coatings and intumescent coatings, flame retardants for wood and other cellulose-containing products, as reactive and/or nonreactive flame retardants for polymers, for producing flame-retarded polymer molding compositions, for producing flame-retardant polymer moldings and/or for the flame-resistant treatment of polyesters and cellulose pure and mixed woven fabrics by impregnation. 
     
     
         13 . The use of ethylenediphosphinic acids as claimed in at least one of  claims 1  to  5  as binders for foundry compositions, mold sands; as crosslinkers or accelerators in the curing of epoxy resins, polyurethanes and unsaturated polyester resins; as polymer stabilizers such as light stabilizers, free-radical scavengers and/or heat stabilizers for woven cotton fabrics, polymer fibers, plastics; as crop protection agents such as plant growth regulator, as herbicide, pesticide or fungicide; as therapeutic agent or additive in therapeutic agents for human beings and animals, e.g. as enzyme modulator, for the simulation of tissue growth, as sequestering agents, e.g. for the control of deposits in industrial water piping systems, in mineral oil recovery and in metal treatment agents; as mineral oil additive, e.g. as antioxidant and for increasing the octane number; as corrosion inhibitor in laundry detergent and cleaner applications, e.g. as decolorizing agent in electronics applications, e.g. in polyelectrolytes for capacitors, batteries and accumulators, and as free-radical scavengers in photosensitive layers; as aldehyde scavengers; as formaldehyde scavengers in adhesives, moldings, e.g. in building applications, automobile, shipbuilding, aircraft and space flight industries, and for electrical engineering, with it surprisingly having been found that the phosphinic acids of the invention can be used for reducing the liberation of aldehyde, and as acetaldehyde scavengers in plastic beverage bottles. 
     
     
         14 . A flame-retarded thermoplastic polymer molding composition containing from 0.5 to 45% by weight of ethylenediphosphinic acid as claimed in at least one of  claims 1  to  5  and from 0.5 to 99.5% by weight of thermoplastic polymer or mixtures thereof, with the sum of the components being 100% by weight. 
     
     
         15 . A flame-retarded thermoset composition containing from 0.1 to 45% by weight of ethylenediphosphinic acid as claimed in at least one of  claims 1  to  5 , from 40 to 89.9% by weight of unsaturated polyesters and from 10 to 60% by weight of vinyl monomers, with the sum of the components being 100% by weight. 
     
     
         16 . A flame-resistant epoxy resin containing from 0.5 to 50% by weight of ethylenediphosphinic acid as claimed in at least one of  claims 1  to  5 , from 5 to 99.5% by weight of an epoxy resin and from 0 to 20% by weight of a hardener, with the sum of the components being 100% by weight.