INFORMATION

F O R E I G N D E T E R G E N T S FOR M O T O R OILS (SURVEY OF PATENTS FOR 1961-1964) A. V. V i l e n k i n

a n d N. F. B o g o m o l o v a

As a result of great increase in the speed of modern gasoline and diesel engines, very rigid demands are made of motor oils. One of these is the necessity for ensuring a high degree of cleanness for engine parts under different operating conditions. This requirement can be satisfied only by introducing special additives in the oil which raise its washing (detergent-dispersing) properties to the required level. Therefore, outside the Soviet Union, attention is focused on developing new and more efficient additives on a large scale and at a reasonable cost. Analysis and generalization of patents for detergents published during the 1961-1964 period makes it possible to get an idea about the trend of research by foreign investigators. In this survey patents were examined only for those additives which, in the opinion of authors of the patents, either have washing properties exclusively or in which these properties prevail over all other properties. Therefore, the patents for multipurpose additives, the washing properties of which are valued equally with other properties, were not included in this survey; they should be the subject of a separate examination. The majority of detergents may be classified as belonging to the following five types of compounds: products of the reaction between hydrocarbons (usually polybutenes of different molecular weight) and phosphoric sulfides, later subjected to hydrolysis and neutralized, the latter process being accomplished in the presence of different chemical compounds; oxidized mineral oils or hydrocarbons neutralized with oxides or hydrates of metal oxides; salts of sulfonic acids obtained by sulfuration of petroleum fractions or hydrocarbons; high-molecular-weight compounds obtained by means of polymerization or copolymerization of two or more monomers; derivatives of amines and imides. Phosphorosulfured Hydrocarbon Base Additives are usually obtained by treating different hydrocarbons with phosphoric sulfides, mostly P2S5, preference being given to polybutenes with molecular weight of 750-1500. Products of the reaction are hydrolyzedwith water vapor and neutralized. The detergents described in the patents differ from one another in the conditions under which they were obtained and mainly in the method of neutralization. Neutralization is accomplished with Ba oxide or hydroxide (less frequently Ca) in the presence of the following compounds: aliphatic alcohols C1-C2 [1], alkyl phenols [2], atkyl phenols with addition of NH4OH [3], formaldehyde [4], formic acid and methyl alcohol [5], orthophosphoric (or hypophosphorous) acid and methyl alcohol [6], dialkyldithiophosphoric acid and alcohols [7], thiophosphoric acid in combination with either dipolyamines or polyamines, for example, with triethylenetetramine [8]; sulfonic acids and aliphatic alcohols, for example, methanol [9], boric acid and aliphatic amines, forexample,ethylenediamine or triethanolamine [10]; boric/acid and polymers of unsaturated fatty acids, for example, obtainable during manufacture of sebacic acid from the residue of dry distillation of castor oil, which is a polymer product [11]. For neutralization of hydrolyte, the use of urea [12] and other derivatives of carbamic acid [13] either in pure form or in combination with MgO [14] is suggested; the effectiveness of these additives may be intensified by additional treatment with ethylene oxide. Very good results are obtained from double treatment of theproduct of reaction between polybutene and PzSs with Ba methylate dissolved in methyl alcohol [15]. The Ba content in the additive obtained in this manner is as high as 16%. For improving the washing properties of additives of this type, in a number of patents it is recommended: a) to remove inorganic phosphoric acids from hydrolite prior to its neutralization, for example, by treatment with aqueous solution of magnesium silicate and to accomplish the neutralization in cellos olve medium [16]; b) torrent with PzSs polybutene that was first chlorinated and containing 0.1 to 20 wt. % chlorine [17] or polybutene dissolved in selectively treated mineral oil, which also reacts with phosphoric sulfide [18]; c) to use the action of highly Translated from Khimiya i Tekhn01ogiya Topliv i Masel, No. 8, pp. 58-89, August, 1966.

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TABLE 1. The Content of Principal Elements in Phosphorosulfured Hydrocarbon Base Additives Patent no. in the published list

Content of elements, % Ba

11

13 15 t6 17 18 19

p

other elements

s

1,4

4

5 6

ionizing radiation on phosphorosulfured polybutene in place of hydrolysis and neutralization processes [19].

6,5 8,2 13,9

1~,8 6,9 8,7

1,0 1,4

1,2 1,7 1,2

0,1 0,9

07;

07;

1.5 0,9

B-0,3 N- 1,2 CO~- 1,0

The content of principal elements in some of the enumerated additives is given in Table 1.

0,8

TABLE 2. Results of Testing Phosphorosulfured Hydrocarbon Base Additives by CRC-L-I-545 Method

Patent ~dditive no in J . " , ]conc., tile pUD- r lished | % list [ 6

Additional additive and its concentration

5,5

0 , 8 %sulfured

3,3

dipelene

Surface size of upper piston slot coated with carbon deposits 120h --

7 11

17

2,8 0,5

1% zinc dialkvldithiophosphate

In some patents it is recommended that different petroleum fractions be used instead of polybutene. For example, an effective detergent for engine operation at different temperature conditions is obtained from the reaction between P2Ss and deasphalted and deparaffined residual oil (v~. 9 = 35 est. vise. index = 95) and neutralization of the reaction product with Paranoks-47 additive. The latter is an oil solution of alkylphenol sulfide treated with Ba(OH)2 in the presence of CO2 [20].

I

240 h I 480h 8

22 15 15

7

The high-washing properties of phosphorosulfured hydrocarbon base additives were confirmed by the results of tests in Caterpillar diesels according to CRC L1-545 method (Table 2). In every test, the piston remained clean and carbon deposits appeared only in the upper piston slot, occupying no more than 25% of its surface after 480 h of operation. Oxidized Hydrocarbon Base Additives are obtained by neutralization of oxidized oil fractions. Additives obtained by neutralization of organic acids may also be put in this category. In particular, the following acids are used for obtaining the additives: isostearic [21], oleic [22], sulfonic, naphthenic or alkylsalicyclic [23] and also certain other acids [24, 25]. Salts of Ca, Mg, Ba, Pb, Sn, Zn, Co, and Mn are obtained as a result of their neutralization.

Oil fractions used in the preparation of additives are oxidized by passing air through the product heated to 100-350~ First, a neutralizing reagent-oxide or hydroxide of alkali earth metal (Ba, Ca, Mg) is added to the oil being oxidized. For intensifying the effectiveness of Ba sulfonate [26] or ammonia [27]. A similar result is obtained by dissolving up to 1% Ba octyl or dodecyl phenolate in the neutralized and oxidized oil. Ordinarily from 3 to 12% Ba or other metal is contained in additives. Sulfonates and their derivatives base additives continue to occupy an important place among detergents. Particularly recommended is a highly basic sulfonate with higher Ca content than the stoichiometric ratio between the sulfonic acid residue and the metal calculated for an average salt. In these additives, this ratio is as high as 1:3128] or even 1:9 [29]. Also recommended are calcium and nickel salts of stearyleyclohexyltetralinsulfonic acid, tetradecyldicyclohexylbenzenesulfonic acid, and 2-oetyldodecyleyclohexyltetralinsulfonic acid [30], Ca dinonylnaphthalene sulfonate [31], monosulfonate of N-replaced aminopropylamines [32] and Na alkylaromatic sulfonates [33]. In certain eases, in order to increase alkalinity of the additive, the neutralized sulfonate is treated by blowing COz through it [34-36]. Effectiveness of the action of sulfonates may be increased by introducing oxyalkyl groups into the radical [34] or by combining these additives in the oil composition with other additives, for example, Mg naphthenate [37], disulfides [38], or Ba-salt of amylphenol sulfide [39], alkymide Of dicarboxylic acid containing polyolefin radical with molecular weight of 600-3000 [40], dispersions of hydrate of Ca oxide [41] or Ca alcoholate [42]. The additives enumerated above contain up to 5% Ca or other metals. The washing properties of sulfonates offered in the patents may be judged from the following examples. The effect of adding sulfonate to the oil and also mixing it with alkymide of diearboxylic acid [40] was evaluated in Pitier AV-1 engine. It was determined that if the oil without additive had a rating of 45, then it was possible by separately introducing sulfonate and alkymide in 3% concentration to raise the rating of engine piston cleanness to 94.2 and 91.7, respectively. Owing to synergetic

576

action displayed with the simultaneous addition of 2% sulfonam and 1 % alkymide to the oil, the rating of engine piston cleanness increased to 98.2. Another additive [41] in 2.7% concentration was added to the oil and tested in a Caterpillarengine according to CRC-L-I-545 method, using a fuel with 1% sulfurcontent. After 480 h of operation, cleanness of the engine piston had the rating of 99 and there was absolutely no deposit in the upper piston slot. Polymer and Copolymer Compounds Base Additives received ever increasing attention during the last 5 years, principally because they are ash-free additives with high detergent-dispersingaction. In most patents it is recommended that the additives be obtained by means of copolymerization of twomonomers containing polar and oleofilicgroups, for example, allyl alcohol and laurylmethacrylate [48],methallyl acetate and stearycrylate [43], laurylmethacrylate and acrylates containing polyglycol groups, for example, methopoly-

ethyleneglycolmethacrylate [44], glycidylmethacrylate and stearylmethacrylate [45], w-hydroxyamyl-or hexylmethacrylate and stearymethacrylate [46], dodecylmethacrylate and methacrylamidpolyethyleneglycol with molecular weight of 1000 [47], stearylmethacrylate and t3 -hydroxyethylmethacrylate [48]. Sometimes three or more monomers are involved in copolymerization. As examples of copolymers obtained in this way one can cite compounds that are formed by copolymerization of dodcyl-, oxadecyl- and glycidolmethacrylates [49], or the first two monomers and glycidolmethacrylate in which the epoxy group is related to primary alkylamines, for example, 2-ethylhexylamine, with formation of caprolactam-polyarnide chains [50], cetyl-, stearyl- and ~ -(N-2-oxazolidinonyl) ethylmethacrylates [51], octadecyl- and tridecylmethacrylates with potyethyleneglycol sulfide [ 52]. An effective copolymer additive was obtained by means of copolymerization of stearymethacrylate and acrolein and treating the obtained copolymer with hydroxylamine; thus, the copolymer contained polar groups of complex ester and oxime [53]. Effectiveness of the copolymer additives increases with simultaneous introduction into oii compositions of certain other compounds, for example, when combining a copolymer of vinyl pyridine andlalkylmethacrylate with N-(aminoalkyl)imidazole salt of alkylphosphoric acid [54], a copolymer of maleic acid and vinyl acetate with alkoxylated phosphorosulfured polybutene [55]. It is also recommended to add dialkylhydroxybenzene alcohol [56] or chrome alkylsalicylatein which alkyl has Cs-Cs0 [57]. It is of interestto note that with addition of isopropyl alcohol to copolymerized monomers, the yield of the final product increases materially [58]. Additives with good washing propertiesare also obtained with the base of graft-copolymers [59, 60] and metalcontaining polymers, for example, copper salt of partiallyhydrolyzed polymer of laurylmethacrylate [61] or polyisoburylene with molecular weight of 18,000, mixed with cornmemial amines and subjected to treatment in a homogenizer [62]. Effectivenes~ of the washing property of copolymer additives may be judged from the results of testing oils with these additives in engines. For example, oil with 10% Ca sulfonate, 1.2% zinc dihexyldithiophosphate and 1% additive in patent [43], in the course of tests according to CRC-L-I-545 method, caused only 10% fill-up of the upper piston slot, while without the polymer, the slot was 85% filled. In the case of testing by PL-2 method in a Chevrolet engine, SAE-30 oil which contained 12 mmol/kg Zn butylhexyldithiophosphate, the piston cleanness rating was only 3. Introduction in the oil of an additional 1% copolymers in patent [49] raised piston cleanness to 4.7 rating and in patent [50] to 5.4 rating. Derivatives of Amines and Imides are a second source for obtaining ash-free detergents. Imide derivatives of suceinic acid especially are widely recommended for these purposes. In particular, an exceptionally high degree of cleanness of parts in the cylinder-piston group in Caterpillar (L ~ I) and Chevrolet (PL = 2) engines was ensured by adding N-dimethylaminopropylalkenylsuccinimide to the oil [63]. Also noted was high effectiveness of such compounds as N-polyamine-C-alkenylsuccinimide [64] and alkenylsuccinimides of piperazine, including highmolecular-weight hydrocarbon radicals, for example, polybutene [65]. N,N'-(3, 6, 9-ttiazoundeeylene)-bis-polybutenesuccinimide and others similar to it [66]. Effectiveness of additives of the type under discussion increases when they are used in a mixture with alkylated bis-phenols [67] or Zn dithiophosphate [68].

577

Among other succinic acid derivatives m a y be mentioned products of the reaction of polyisobutylenesuccinic anhydride with tetraethylpentamine or d i e t h y l e n e t r i a m i n e [69]. Succinic acid with i m i d a z o l i n e [70] or phosphorosulfumd polybntene with linear polyamine [71]. Amines in pure form are seldom used as detergents. At the same t i m e , they enter into the composition of several derivatives possessing washing properties, as for example, the product of the reaction of a copolymer of m a l e i c anhydride and polybutene with N-(B - a m i n o a l k y l ) p i p e r a z i n e [72] or with aminomethylpyrrolidine [73], octadecanoyl-bls-[B - ( 2 - h e p t a d e c y l - l - i m i d a z o l y l ) e t h y l ] amine [74], etc. Sometimes amines are used in p l a c e of hydrocarbons [75] in the process of manufacturing additives, or as one of the components of additives. For e x a m p l e , amides with good washing properties are obtained by treating polyisobutylenepolycarboxylic a c i d with t e t r a e t h y l pentamine or with N , N ' - d i m e t h y l - l . 3 - d i a m i n o p r o p a n e [76]. Products for similar purposes are obtained from the reaction of polybutylene with thiophosphoric acid and polyamine and also from treatment of the product of reaction between olefins and SO2 with a primary amine [77]. The simple mixing of fatty acid polyamides with tetraethylpentamine makes it possible to obtain a sufficiently e f fective detergent that also has depressant action [78]. Compounds of Other Types are used c o m p a r a t i v e l y seldom as detergents. Nevertheless, special mention should be made of the appearance in the patents of compounds containing boron. Thus, borates of a c y l a t e d p o l y saccharides, for e x a m p l e , m o n o - 2 - e t h y l h e x a n e - l , 3 - b o r a t e - p o l y - ( d i l a u r y l m a n n o s i d e ) [79], different unsaturated esters of boric acid [80], etc. are offered for use. Introduction of boric a c i d in the reaction during manufacturing of certain well known detergents decreases the viscosity and increases the effectiveness of the latter [11, 81]. In concluding the survey, we will mention as before the fact that some attention is still given to detergents with alkylphenol compound base. In the patents one may encounter a new method for obtaining Ba alkylphenolate [82], offered are Sr-, Mg- and other salts of bis-(oxyphenyl)-alkylbenzene [83], (alkylphenyl)-polyethoxyethanol [84], complex salts of the products of alkylphenolaldehyde condensation [85, 86], Ba salt of ester carbonate of alkylphenol sulfide [87], and esters of oxyalkylamd alkylphenolformaldehyde resins [88]. PATENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28

5~/8

USA Pat. No. 29624931 for 1960. 29. British Pat. No. 970786 for 1964. 30. Belgian Pat. No. 619589 for 1962, 931. British Pat. No. 910738 for 1962. 32. FRG (Fed. Rep. Germ.) Pat. No. 1123479 for 1962. 33. USA Pat. No. 3073780 for 1963. 34. British Pat. No. 936650 for 1963. 35. Belgian Pat. No. 625376 for 1963. 36. USA Pat. No. 3089851 for 1963. 37. USA Pat. No. 3086940 for 1963. 38. USA Pat. No. 3086941 for 1963. 39. French Pat. No. 1278667 for 1962. 40. Belgian Pat. No. 608913 for 1962. 41. French Pat. No. 1330330 for 1963. 42. British Pat. No. 965325 for 1964. 43. USA Pat. No. 2987512 for 1961. 44. USA Pat. No. 3108960 for 1963. 45. BelgianPat. No. 626428 for 1963. 46. USA Pat. No. 3003964 for 1961. 47. 48. USA Pat. No. 2969324 for 1961, 49. USA Pat. No. 3071546 for 1963. 50. USA Pat. No. 3052529 for 1962. 51. FRG Pat. No. 1122526 for 1962. 52. USA Pat. No. 3055828 for 1962. 53. USA Pat. No. 3055829 for 1962. 54. USA Pat. No. 3069355 for 1962. 55. USA Pat. No. 3121690 for 1964. 56. USA p ~ No~ 3133019 for 1964.

USA Pat. No. 3057896 for 1962. French Pat. No. 1313054 for 1962. British Pat. No. 903976 for 1962. USA Pat. No. 2989564 for 1961. USA Pat. No. 3050464 for 1962. USA Pat. No. 3032501 for 1962. USA Pat. No. 3076841 for 1963. British Pat. No. 941441 for 1963. USA Pat. No. 2959545 for 1960. USA Pat. No. 2964474 for 1960. USA Pat. No. 3108961 for 1963. French Pat. No. 1360843 for 1964. USA Pat. No. 3041278 for 1962. Belgian Pat. No. 629945 for 1962. USA Pat. No. 3033790 for 1962. USA Pat. No. 3052648 for 1962. Dutch Pat. No. 103955 for 1963. British Pat. No. 947800 for 1964. British Pat. No. 917923 for 1963. British Pat. No. 896435 for 1962. USA Pat. No. 3095402 for 1963. USA Pat. No. 3114711 for 1963. French Pat. No. 1366096 for 1964. USA Pat. No. 3063971 for 1962. Dutch Pat. No. 106079 for 1963. USA Pat. No. 3116249 for 1963. British Pat. No. 959327 for 1964. FRG Pat. No. 1137158 for 1962.

57. 58. 59. 60. 81 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72.

USA Pat. No. 3052630 for 1962. British Pat. No. 861905 for 1961. USA Pat. No. 3067163 for 1962. Belgian Pat. No. 630311 for 1963. USA Pat. No. 3123563 for 1964. French Pat. No. 1347945 for 1964. USA Pat. No. 3018250 for 1962. USA Pat. No. 3131150 for 1964. USA Pat. No. 3024237 for 1962. USA Pat. No. 3154560 for 1964. British Pat. No. 946032 for 1964. USA Pat, No. 3018247 for 1962. British Pat. No. 922831 for 1963. French Pat. No. 137454I for 1964. Belgian Pat. No. 636554 for 1963. USA Pat. No. 3024195 for 1962.

73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 88. 84. 85. 86. 87. 88.

USA Pat. No. 2984673 for 1961. USA Pat. No. 3152080 for 1964. FRG Pat. No. 1078722 for 1960. French Pat. No. 1370506 for 1964. USA Pat. No. 3116257 for 1963. USA Pat. No. 3110673 for 1963. USA Pat. No. 3067192 for 1962. USA Pat. No. 3152166 for 1964. Belgian Pat. No. 633504 for 1963. USA Pat. No. 3062897 for 1962. FRG Pat. No. 1126055 for 1962. USA Pat. No. 3123570 for 1964. USA Pat. No. 3014868 for 1961. USA Pat. No. 3070576 for 1962. FRG Pat. No. 1152778 for 1964. USA Pat. No. 3096286 for 1963.

579