Patented Nov. 22, 1949 ' 2,488,662 PATENT 2,438,662 METAL onoAigo-rnosggglfrgs , Bruce B. Farrington, James 0. .Glaytomand Johns, , T. Rutherford, Berkeley, Qallivt}, yesswignorsjto . California _ Beseaijch._~._(,3,0rl10l1él,t,ifln San-FY5111 l” dementia .cersvraiion of. liélawai ‘ '*' No Drawing. Application June. 25,1946?» Serial No.~.6'79,2,62:.¢‘ " ' ' ' 7 Claims.‘ ..(_Cl. ZGOF-AZQLN 1 _ 2 : This-invention relates to high molecular weight, wateninsomble,,mineral oil-soluble zincand cad: ., miuinsalts of acid esters-of phosphoric, acid ,. ' The polyvalent metal saltsdof iaciduesters, of ; phosphoricuacid have value'asimprovement agents, 5 for mineral lubricating; oils. Thus, .theyare e?ec; ,. _ tiveywhen usednaloneyto increase the resistance phosphate5i to .obta-inwthe esire of suchioils-to oxidation andithey have particular u the l I " “ eféat ' “ ‘ value'ynwhenusedilin combination. with ;a poly- _ ' ' ‘ valent<=;metal..salt;of .anlalkylphenol, to inhibitlO of it‘v'is required“ 1 . - corrosionof alloy ibearingslsuch as copperelead > It'ls anobj‘e'ct of the present,y_inv,ention, to pro; , Unitedbearings' ‘States “Sewimwxampla Patent-.,,-No. ‘2,228,659 Famngton andcNeelyu et a1” , videeecleesnf.polyvalentgnetal's,‘tsbraéi'h ' 5511; “ et al.,»United States-PatentNo.x2,228,6'71. _ For convenience, these polyyalentmetal. salts T15 of acid-esters of phosphoric acidvwil-l-be frequently referred; to as polyvalent inetalphosphates- " , L pd ""2, r’ Y ~ " oi,’“ theainvention“l's‘alts‘ f ‘acidfestersiof ,to provide. Certain» of thesepolyvalentmetal phosphates, . phosp oric' "acid ,hIGIZLHIIIB , such~as the calciumandgbariurnsalts, are water- - watevrxsolii \ thaiilthe‘alkalin earthfmetalsaltsfj solubletointhatdi?iculty mineral a lubricatingsufficient is encountered extent; oilsa‘are orin theirpractice-sufficiently-40w; solubilitiesl Thus, I20 wear,of these" (wheniused uoricl'ationxlasalfester'sandwhich in 1mii‘leral, aaiiei‘eaus‘éas‘ lubricating 'v‘ils itmetal-‘phosphate is- a common practice in oil ‘in to relativelylarge disperse the rpolyvalent amount, > ’ " ‘ “ of thejorderof 50% ‘ on the weight of oil-phosphate 25 solution, to produce a concentrate or stock solu- " tion; This concentrate is stored a'ndrshipp'edhto be ‘ blended with" more oil to produce a ?nished prod- ' uct containing about 0.25 to 2.0% of phosphate.~ The aforesaid calcium andbarium phosphates are 30 _‘ , di?icult to blend homogeneously ,iPFQHSY-Ich‘coQM Thes Land.,otherllobiectsoftheyinvention will”. centrates; and erenanished oilscontainiaa lesser be apparentfffioimthe ensuing’ ,éiéscr‘ipiibnianeij; amounts are prone to form emulsions 0n agitation thei'apbended claims. " " " ' ‘ ' " withacceptance, ,water, ‘testsnwhich,‘or they may include,centrituging, ,fail ‘to ,pass, stringent 9315,35 salts‘of'aci‘dWe-l'iaiefdisco esteem éifed phosphoricacidai'e that thezincandeadmium superior}; high Speed. 7 v > in thatgthey .a‘re'characterif'zedby lowlwiater-solllr,. Certain,otherjpolyvalent metaL-QhQSphatessuQh v, bility‘ijand .‘hi‘gh ToihsOIubilityQj Moreover; they dog‘ as the alminum phosphates, although more. 011; , not_,_ca_ ‘e xcessiyé ,wear'lof \workinglba?s ‘of soluble , and, less water-soluble, ‘. cause, some .dif?: machinea ' I .lilbri‘cat'edlby .' mineral, oil's; oontaini'?gb'm culty,combustion owing engines,to wear. of such working-partsoi (ascylinder :andpiston, internal T40 them,‘The salts of the inventionarelof two types, de walls and'piston rings. v rived from the monojestersian Jtheh (ll-esters: Theabove-mentioned oil-Water ,solubilitygdi?'ie culties vcan .vbe solvediby.‘ employinguphosphoric, /0—,-R_1 O—,R1., esters of su?iciently high moleculanweight aloe-V845 :y o=13_‘_,p_R,, holswor,phenols,~but{to obviate. these di?iculties 3 ‘ \OH‘ \01; fullyfying--_- it radicalsis necessary, of excessively,by this means, :high to .useesteriv.molecula ; 11:;q Di'eateiswt weight.» These excessively highumolecular weight-m Mono-esters‘ , radicals are more expensive than.the._more,_com . - mon radicals of lowermolecular weight, contain 7. Sa1§$¢~9f;'th§;: mqno-gstersmaygbei pormalisaltsni ingu5 to 20 carbonatoms. Also, the ester‘ifyin‘g. I (Ml-‘511904) or acld salts (R1HPO4_M—R1HPQQ@=; radical functions primarily =las-an oil-solubilizingf. In theabpyertormulaaRrandRz-arehydrocarbon agent-4phosphate. and; isthe impartedbritha-zimreaeic effective-inhibiting}acacia (metaof'gthe~~.li 555 radieelsnwhich.mygbernonshrqrqcarbonsubstitueu..mncl substituted;lhowereabye M115 sine. (H .l oxygen-phosphoruszeareua sfl‘o.~tilee>.<teatthersa - . cadiainaeBasicsaltS.maye159llqeiiiprmeqlirema 2,488,662 4 either the mono- or the ii-esters. Normal salts solution by means of aqueous KOH and the acid of the types was freed by acidi?cation with hydrochloric acid. R1 R1 The dicetyl phosphoric acid was recrystallized twice from 95% ethyl alcohol and once from ab , o t t solute alcohol. It had a melting point of 63-64.5° o=r/ “\M o=rl'~o-M-o-i>=o C. and analyzed 5.78% phosphorus (theory 5.6%). The monocetyl phosphoric acid analyzed 9.73% PM 5 t phosphorus (theory 9.64%). ILA Both acids were white crystalline materials, the are preferred, and of these the salts of the di mono-ester having a ?aky appearance and the di esters are preferred as being more oil-soluble. The ester, a granular appearance. radicals R1 and R2 contain each not less than To prepare zinc monocetyl phosphate, the po 5 carbon atoms, preferably not less than 10 car tassium salt was reacted with an equivalent bon atoms, and preferably not more than 20 car amount of zinc chloride in alcohol solution at 150° bon atoms. These radicals may be alkyl (e. g., F. over a period of 5 hours. The mixture was then amyl, hexyl, octyl, decyl, lauryl, tetradecyl, cetyl cooled to precipitate white zinc monocetyl phos and eicosyl), alkylene (e. g., octenyl, hexadece phate, which was washed with hot water to re nyl), cycloaliphatic (e. g., napthenyl, cyclohexyl move potassium chloride and unreacted zinc and methylcyclohexyl), aryl (e. g., phenyl), al chloride, as shown by the appearance of only a karyl (e. g., methylphenyl and cetyl phenyl), or faint cloud on treating 100 cc. of ?ltrate with 10 aralkyl (e. g., benzyl, phenylstearyl and cetyl cc. of 0.05 N silver nitrate. The salt was then benzyl) radicals. Saturated aliphatic and cyclo washed with hot ethyl alcohol and dried in a desic aliphatic radicals and aryl radicals substituted cator at reduced pressure. by one or more saturated aliphatic or cycloali To prepare zinc dicetyl phosphate, dicetyl phos phatic radicals are preferred. phoric acid was reacted with zinc oxide under re Mixed radicals, e. g., alkyl-cycloaliphatic and flux for 7 hours, in a solvent consisting of two alkylalk-aryl, may be used. Likewise, mixed salts parts by volume of benzene and one of ethyl a1 of mono- and di-esters may be used, c. g., mixed cohol. The desired salt was obtained as a solid zinc salts of mono-cetyl phosphoric acid and di precipitate and was washed with ethyl alcohol and cetyl phosphoric acid. 30 extracted with hot benzene. The benzene was The parent esters of the salts of the inven evaporated and the precipitated salt was dried tion can be prepared by methods :well known in under reduced pressure. Analysis: Found, per the art. Certain of the parent esters, e. g., mono cent Zn, 5.9; per cent P, 5.4. Theory, per cent and dicetyl phosphates and mono- and dichol Zn, 5.6; per cent P, 5.4. esteryl phosphates are described in the literature. Cadmium mono-cetyl phosphate was prepared Exemplary methods of preparation are provided and puri?ed in the same manner as the corre sponding zinc salt, cadmium chloride hydrate by the speci?c examples below and by Plimmer eing used in place of zinc chloride. Analysis: and Burch, Journal of the Chemical Society, 1929, Found per cent Cd, 29.1; per cent P, 6.6. Theory, pages 279-291. per cent Cd, 25.9; per cent P, 7.2. The zinc and cadmium salts can be readily pre 4.0 Cadmium dicetyl phosphate was prepared by pared from the parent esters, or from alkali metal reacting potassium dicetyl phosphate with an salts of the same, by methods well known in the equivalent amount of cadmium chloride hydrate art, as exempli?ed by the speci?c examples and in alcohol at 150° F. The solid reaction product by Plimmer and Burch, op. cit. was washed with ethyl alcohol, dried, washed with Examples of salts of the invention are: normal hot benzene, recovered from benzene solution by zinc and cadmium mono-amyl phophates, normal evaporation of the solvent and dried under re zinc ,and cadmium mono-octyl phosphates, nor duced pressure. mal zinc and cadmium mono-lauryl phosphates, normal zinc and cadmium mono-eicosyl phos EXAMPLE 2 phates, normal zinc and cadmium mono-methyl 50 Mono-tart. amylphenyl phosphoric acid and zinc cyclohexyl phosphates, normal zinc and cadmium and cadmium salts of the same mono-benzyl phosphates and normal zinc and cadmium mono-cetylphenyl phosphates; also, the p-Tert. amylphenol was reacted with an equiv corresponding normal zinc and cadmium di-amyl, alent amount of phosphorus pentoxide at 300° F. di-octyl, di-lauryl, di-eicosyl, di-methylcyclo 55 for 3 hours. The reaction product was puri?ed hexyl, di-benzyl and dicetylphenyl phosphates. by recrystallization from petroleum ether to give The following speci?c examples will serve fur white, ?aky crystals, melting point 210-214“ F. ther to illustrate the preparation and properties The zinc salt was prepared by re?uxing one molec of the salts of the invention. ular proportion of the acid with 0.68 molecular EXAMPLE 1 60 proportion of zinc oxide in a solvent consisting of Mono- and di-cetyl phosphoric acids and zinc two parts by volume of benzene and one of ethyl alcohol for six hours. The solid reaction product _ and cadmium salts of the same ' was washed with 5% aqueous acetic acid to re A mixture of mono- and dicetyl phosphoric move unreacted zinc oxide, then with ethyl alcohol acids was prepared by reacting 76 parts by weight to remove unreacted acid, and dried under re of cetyl alcohol with a mixture of 17 parts of duced pressure.