US3729417A - Quenching oil compositions - Google Patents

Abstract

QUENCHING OIL COMPOSITION OF THE INVENTION COMPRISES MINERAL QUENCHING OIL CONTAINING A SPECIFIC COMPOUND BELONGING TO (1) ALIPHATIC ACIDS OR DERIVATIVES THEREOF, (2) PHOSPHITES, (3) THIOPHOSPHITES, (4) PHOSPHATES, (5) ZINC DIALKYL DITHIOPHOSPHATES, (6) DISULFIDES, (7) TETRAALKYLTHIURAM SULFIDES, (8) DITHIOCARBAMATES OR (9) MERCAPTANES, SAID COMPOUND BEING CONTAINED IN THE RANGE OF 0.05 TO 5 WWEIGHT PARTS, BASED ON 100 WEIGHT PART OF THE MINERAL QUENCHING OIL. THE PRESENT QUENCHING OIL COMPOSITIONS ARE CAPABLE OF QUENCHING METALS AND, AT THE SAME TIME, IMPARTING LUBRICATING PROPERTY TO THE METALS QUENCHED THEREWITH.

Description

3,729,417 QUENCHING OIL COD [POSITIONS Kametaro Hashimoto and Hiroo Nakamura, Toyota-ski, Toshio Okada, Kyoto-fu, and Misngn Tanaka and Kazuto Fnkuhara, Kobe-511i, Japan, assignors to Toyota .Iidosha Kogyo Kabushiki Kaisha, Toyota-shi, Aichi-ken, and Nippon Grease Co., Ltd., Dojima, Kitaku, Osaka-ski, Japan No Drawing. Filed Feb. 12, 1970, Ser. No. 10,990 Claims priority, application Japan, Feb. 14, 1969, 44/ 11,199 Int. Cl. Cltlm 1/48 US. Cl. 25246.6 3 Claims ABSTRACT OF THE DISCLOSURE Quenching oil composition of the invention comprises mineral quenching oil containing a specific compound belonging to (1) aliphatic acids or derivatives thereof, (2) phosphites, (3) thiophosphites, (4) phosphates, (5) Zinc dialkyl dithiophosphates, (6) disulfides, (7) tetraalkylthiuram sulfides, (8) dithiocarbamates or (9) mercaptanes, said compound being contained in the range of 0.05 to 5 weight parts, based on 100 weight parts of the mineral quenching oil. The present quenching oil compositions are capable of quenching metals and, at the same time, imparting lubricating property to the metals quenched therewith.

This invention relates to new and useful quenching oil compositions and to the method of quenching metals therewith.

Hardening metals such as steel by quenching operation is well known in the art and various quenching oil compositions have been proposed for the purpose. By employing known compositions, however, the hardness of the metal quenched therewith increases but no lubricating property is imparted to the metal surface. In the prior method, therefore, the metal products hardened by quenching operation are further subjected to lubricating treatment whenever such property is required. Bolts used for securing a member to which high valuable stress is applied, for example, must effect a high order of fastening force, and therefore, after being hardened by quenching operation and washed with trichloroethylene, they are subsequently subjected to surface treatment to render the surface thereof lubricious. Thus the prior methods require two separate procedures and apparatuses for hardening the metal and for imparting lubricity to the metal. As far as the applicants are aware, no attempts have been heretofore made to obtain quenching oil compositions capable of quenching and at the same time imparting lubricating property to the metal surface quenched therewith.

One object of the invention is to provide a quenching oil composition whereby not only the hardness of metal quenched therewith is increased but also excellent lubricity can be imparted to the surface thereof.

Another object of the invention is to provide a quenching oil composition which makes it possible to conduct the step of hardening metal and, at the same time, the step of surface treatment of the metal for lubricity.

These and other objects and advantages of the invention will be apparent from the following description.

According to the researches of the present inventors it has now been found that when a specific compound is added to a conventional quenching oil of mineral origin in a predetermined amount and metal to be hardened is quenched with the resultant composition the hardness of the metal thus treated is increased and excellent lubricity is simultaneously imparted to the metal surface.

United States Patent 0 The specific compounds which display the above effect and which are used in the invention are classified into nine groups to follow:

( 1) An aliphatic acid compound having the formula of (R COO),,,R (I) wherein R is hydrogen, an alkyl of 15 to 17 carbon atoms or C H R is hydrogen, a lower alkyl of 1 to 6 carbon atoms, Cu (II) or Cd (II), and m is an integer of 1 when R is hydrogen or a lower alkyl or an integer of 2 when R is Cu or Cd;

(2) A phosphite having the formula of )a (II) wherein R is hydrogen, an alkyl of 4 to 12 carbon atoms, C H phenyl or an alkyl (C C phenyl but all of the R are not hydrogen;

(3) A thiophosphite having the formula of wherein R is an alkyl of 10 to 13 carbon atoms, R is phenyl or methyl phenyl, n is an integer of 1 to 3 and p is 0 when n is 3, an integer of 1 when n is 2 or an integer of 2 when n is 1;

(4) A phosphate having the formula of wherein R is an alkyl of 1 to 9 carbon atoms, [SI-chloroalkyl of l to 4 carbon atoms, *C H phenyl or methyl phenyl, q is an integer of 1 to 3, r is 0 when q is 3, an integer of 1 when q is 2 or an integer of 2 when q is l;

wherein R is an alkyl of 1 to 12 carbon atoms, phenyl or benzyl;

(7) A tetraalkylthiuram sulfide wherein R is a lower alkyl of 1 to 4 carbon atoms and v is an integer of 1 to 2;

(8) A dithiocarbamate having the formula of wherein R is an alkyl of 1 to 12 carbon atoms, phenyl or an alkyl (C -C phenyl, M is a divalent or trivalent metal, and w is an integer of 2 when M is divalent metal or an integer of 3 when M is trivalent metal; and

(9) A mercaptane having the formula of (VIII) wherein R is an alkyl of 8 to 18 carbon atoms or phenyl. Though any compounds belonging to the above groups (I) to (IX) can be eifectively used in the invention,

phosphites, thiophosphites, phosphates, zinc dialkyl dithiophosphates and dithiocarbamates are particularly desirable. Representative examples of aliphatic acid compounds of the Formula I are formic acid, ethyl formate, isoamyl formate, palmitic acid, heptadecanoic acid, stearic acid, cadmium stearate, oleic acid, ethyl oleate and cupric oleate. Of these formic acid, isoamyl formate, palymitic acid, heptadecanoic acid, cadimum stearate, oleic acid, ethyl oleate and cupric oleate are preferable, the most desirable being heptadecanoic acid. Examples of phosphites of the Formula II are dibutyl hydrogenphosphite, tributyl phosphite, trioctyl phosphite, bis(2- ethylhexyl) hydrogenphosphite, tri(2-ethylhexyl) phosphite, tridecyl phosphite, dilauryl hydrogenphosphite, trilauryl phosphite, trioleil phosphite, triphenyl phosphite, tricresyl phosphite, tris(nonylphenyl) phosphite, diphenyl nonylphenyl phosphite and phenyl diisodecyl phosphite. Of these tributyl phosphite, trioctyl phosphite, tridecyl phosphite, dilauryl hydrogenphosphite, trioleil phosphite, triphenyl phosphite, tricresyl phosphite, diphenyl-nonylphenyl phosphite, tris(nonylphenyl) phosphite and phenyl diisodecyl phosphite are preferable, the most desirable being dilauryl hydrogenphosphite, triphenyl phosphite, tricresyl phosphite and tris(nonylphenyl) phosphite. Examples of thiophosphites of the Formula III are tridecyl trithiophosphite, phenyl dilauryl dithiophosphite, diphenyl lauryl monothiophosphite and trilauryl trithiophosphite. Of theese phenyl dilauryl dithiophosphite, diphenyl lauryl monothiophosphite and trilauryl trithiophosphitc are preferable, the most desirable being phenyldilauryl dithiophosphite and diphenyl lauryl monothiophosphite. Examples of phosphates of the Formula IV are monomethyl phosphate, dimethyl phosphate, diethyl phosphate, diisopropyl phosphate, monobutyl phosphate, dibutyl phosphate, monooctyl phosphate, dioctyl phosphate, B-chloroethyl phosphate, di(B-chloroethyl) phosphate, dioleil phosphate, trioleil phosphate, triphenyl phosphate, tricresyl phosphate and bis(2-ethylhexyl) phosphate. Of these monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, monooctyl phosphate, dioctyl phosphate, mono(fi-chloroethyl) phosphate, di( 8- chloroethyl) phosphate, trioleil phosphate, triphenyl v phosphate, tricresyl phosphate and bis(2-ethylhexyl) phosphate are preferable, the most desirable being a 921-119 weight ratio mixture of monomethyl phosphate and dimethyl phosphate as Well as a 9:l-l:9 weight ratio mixture of Inonooctyl phosphate and dioctyl phosphate. Examples of zinc dialkyl dithiophosphates of the Formula V are zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc dihexyl dithiophosphate, zinc dioctyl dithiophosphate, zinc didecyl dithiophosphate and zinc dilauryl dithiophosphate. Of these zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl thiophosphate, zinc dihexyl dithiophosphate, zinc dioctyl dithiophosphate, and zinc dilauryl dithiophosphate are preferable, the most desirable being zinc dihexyl dithiophosphate. Examples of disulfides of the Formula VI are di-n-propyl disulfide, di-n-butyl disulfide, ditertiarybutyl disulfide, di-n-pentyl disulfide, ditertiaryhexyl disulfide, ditertiaryoctyl disulfide, dilauryl disulfide, diphenyl disulfide and dibenzyl disulfide. Of these ditertiarybutyl disulfide, dilauryl disulfide, diphenyl disulfide and dibenzyl disulfide are preferable, the most desirable being ditertiarybutyl disulfide. Examples of tetraalkyl thiuram sulfides of the Formula VH are tetramethyl thiuram disulfide, tetramethyl thiuram monosulfide, tetraethyl thiuram disulfide, tetrapropyl thiuram disulfide, tetrabutyl thiuram disulfide. Of these tetramethyl thiuram disulfide, tetraethyl thiuram disulfide and tetramethyl thiuram monosulfide are preferable, the most desirable being tetramethyl thiuram disulfide. Examples of dithiocarbamates of the Formula VIII are ferric dimethyl dithiocarbamate, cupric dimethyl dithiocarbamate, zinc dimethyl dithiocarbamate, zinc diethyl dithiocarbamate, zinc dipropyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dipentyl dithiocarbamate, zinc dihexyl dithiocarbamate, inc dioctyl dithiocarbamate, zinc didecyl dithiocarbamate, zinc dilauryl dithiocarbamate, cadmiurn dipropyl dithiocarbamate, cadmium dibutyl dithio carbamate, cadmium dipentyl dithiocarbamate, cadmium dihexyl dithiocarbamate, cadmium dioctyl dithiocarbamate, cadmium didecyl dithiocarbamate, cadmium dilauryl dithiocarbamate, lead dipropyl dithiocarbamate, lead dibutyl dithiocarbamate, lead dipentyl dithiocarbarnate, lead dihexyl dithiocarbamate, lead dioctyl dithiocarbamate, lead didecyl dithiocarbamate, lead dilauryl dithiocarbamate, lead diphenyl dithiocarbamate, antimony dipropyl dithiocarbamate, antimonyl dibutyl dithiocarbamate, antimony dipentyl dithiocarbamate, antimony dihexyl dithiocarbamate, antimony dioctyl dithiocarbamate, antimony didecyl dithiocarbamate, antimonyl dilauryl dithiocarbamatc and zinc ethylphcnyl dithiocarbamate. Of these ferric dimethyl dithiocarbamate, cupric dimethyl dithiocarbamate, Zinc dimethyl dithiocarbamate, zinc diethyl dithiocarbamate, zinc dipentyl dithiocarbamate, cadmium dipentyl dithiocarbamate, lead dipentyl dithiocarbamate, antimony dipentyl dithiocarbaamte and zinc ethylphenyl dithiocarbamate are desirable, the most preferable being cadmium dipentyl dithiocarbamate. Preferable examples of mercaptanes of the Formula IX are n-octyl mercaptane, n-dodecyl mercaptane, cetyl mercaptane, stearyl mercaptane, thiophenol and benzyl mercaptane. Of these benzyl mercaptane is most preferable.

The above compounds are added, alone or in mixture of more than 2 species to mineral quenching oil in the amount of 0.05 to 5 weight parts, based on weight parts of the quenching oil. The resultant composition of the invention is not only eifective as quenching oil but also imparts lubricating property to the surface of the metal quench therewith. The theoretical reason why the lubricating property is imparted to the metal surface treated with the present composition has not been made clear yet, but it is supposed that by the addition of the specific compound as above the metal treated with the present composition is covered with lubricating film which renders the metal surface lubricious. When the amount of the compound added is less than 0.05 weight part per 100 weight parts of quenching oil the resultant composition displays poor effect in rendering the metal surface treated therewith lubricious, while the composition containing more than 5 weight parts of the compound per 100 weight parts of quenching oil displays no better effect but rather adversely affects the cooling property and stability of the oil. Though preferable amount of the compound varies in accordance with the kinds f the compounds used, usually it is in the range of 0.1 to 2 weight parts, based on 100 weight parts of the quenching oil.

The quenching oils used in the invention are mineral oils obtained as distillates from various types of crude oils such as paraflinic or naphthenic crudes. The oils may have a flash point of higher than 0, preferably in the range of to 300 C., and a viscosity of more than 45 RW sec. at 50 C., preferably in the range of 50 to 150 RW sec. at 50 C.

Hardening metals such as steel may be made by any methods of quenching operation known in the art. In general it is conducted by heating the metal to a temperature higher than its critical temperature and quenching the metal by immersion in the present quenching oil composition. The present composition may also be used for quenching of tempered metal, whereby more excellent lubricity may be imparted to the metal surface. In using the present composition it is preferable to heat metal in an atmosphere containing no oxygen, such as in nitrogen or carbon dioxide gas atmosphere, since the presence of oxygen reduces the lubricity of the resultant metal.

For better understanding of the invention examples are given below.

The results of the measurement are shown in Table 1 below.

EXAMPLE 1 TABLE 1 Seventeen kinds of quenching oil compositions were Fatty acid compounds added prepared by adding fatty acid compounds shown in Table 5 Amount coefiiclent I b 1 d d h Comp. added of boundary f 1 P il erminfharnount to l 0 wing5 tsp}??? No. Name Formula (wt. parts) (at50 o.) o minera quenc mg or aving a vlscosity o 9.

1-A-1. F ld HCOOH 1. sec. afl50 C. an? a flash point of 178 C. 80 8 85 5.8

'Ro erpins 0 2.0 mm. in diameter and 29.9 in we 7 0 Q2906 1-B- o 0 H length were heated at 850 C. for 10 rmnutes in an at- 10 H 0 C5 1 0 0 2637 1B.2. do Hoooo H11 2.0 0.2918 mosphere of 9.1 volume ratio nnxture of argon and undo HCOOCZH 3- 0 0.8443 hydr(1)gen...The respect1ve..p1ns thus treated were immec p ti 0 5 00011 1 0 .3392 diatey immersed in respective quenching oil composi- 1C2 -d 0 H @0011 2.0 0. 3392 trons at 80C. for 5 mmutes, then washed with 'trichlorod8 0 11112100011 3.0 0. 3341 h l and d i d 15 1Dl Heplgdeoanoic CIBHKQCOQH 1.0 0.2586

a 1 The lubricity of the roller pms thus obtained was tested 1-0-2 do 015113300011 2.0 0.2573 by the method described in Jukuuke Junkatsu Binran, gigggg: (CWHMCOOhCd 0-4111? pp; 773-775 (1961) published by Nikkan Kogyo Shinbun- 1F1 01613 00101--.- 11% 3 0.5 0.41856 sha, Japan. In this method the roller pin to be tested was 11 33 C H COOCH 1.0 0.41490 rotatably supported by means of steel balls and the based 17 a3 2 5 portion of a pendulum was fixed to the pin so as to allow g (CWHBQCOWZCH 0 34048 the pendulum to swing integrally with the pin. To test 1-H-2 "do.. oflmsooonou 1.0 0.32384 the lubricity of the pin, the pendulum was swung in an omtrol 0 0 4432 atmosphere heated to 50 C. and the amplitude of the first stroke of swing and that of the fifth stroke were EXAMPLE 2 respectively measured. The coefficient of boundary fric- Twenty-four kinds of quenching oil compositions were tion was given by the following equation: prepared by adding phosphites shown in Table 1 above An in predetermined amount to 100 weight parts of mineral f=3 2 quenching oil the same as in Example 1.

Roller pins quenched with above compositions in the wherein f is coefficient of boundary friction, A0 is amsame manner as in Example 1 were measured to determine plitude of the first stroke and All is amplitude of the fifth coefficient of boundary friction as in Example 1 with the stroke. results shown in Table 2 below.

TABLE 2 Coefiicient Phosphites added Amount of boundary added friction Comp. No. Name Formula (wt. parts) (at C.)

(C4H90)3P 0.5 0. 41210 (0411.0)31 1.0 0. 23296 (C4HnO)sP 2.0 0.33280 (C4H0O)3P 3.0 0. 33920 (C8H170)3P 1. 0 0. 39680 (CsH17O)aP 2. 0 0. 39936 (C8H17O)3P 3. 0 0. 28416 (C10H210) 2. 0 0. 40064 (CrzHaaOhPOH O. 1 0. 40960 (CuHzsOhPOH O. 5 0. 23936 (CrzHasOhPOH 1. U 0. 07936 (CmHzaOhP 0H 2. 0 0. 13952 (C12Hz5O)2P 0H 3. 0 0. 23936 (CHE-3503) P 3. 0 0. 36224 2F1 Triphenyl phosphite (Q 0.5 0. 29952 .2 3 Sameas above. 1.0 0 22144 2.0 0 19968 3.0 0 28288 2-G-1 Tn'cresyl phosphite Q0 P 0.5 0 18944 2-G-2. d0 Same as above 1.0 0.17152 2-G d0 2.0 0.17153 2-04 do ..do 3.0 0.17152 2-H-1 Di hen lnon l hen 1 hos hite.. 1.0- 0.23680 2-H- do- Same as above 2.0 0.28680 z-H-a (10-. p 00-. 3.0 0.36608 2-1-1 Tris non l hen 1 hos hite 1.0 0.18560 2-1-1- Phenyl diisodecyl phosphite I 3.0 0.32128 OP(OC10H21)2 Control 7 EXAMPLE 3 Ten kinds of quenching oil compositions were prepared by adding thiophosphites shown in Table 3 below in predetermined amount to 100 weight parts of mineral quench- 8 the same manner as in Example 1 were measured to determine coefiicient of boundary friction as in Example 1 with the results shown in Table 4 below. In Table 4 the mixtures described in Compositions Nos. 4-A to 4-D ing on the Same as in Example L 5 mean 1:1 weight rat1o mlxtures of respective compounds.

TABLE 4 Coeflicient; Phosphate added Amount of boundary added friction Comp. No. Name Formula (wt. parts) (at; 50 C.)

iiid h h t (on P(0)OH nne ypospae a "iypriomethyl phosphate CH3OP(O)(OH): 36608 x ure Dibutyl phosphate (C4HoO)zP (0)011 4 B 1 "{Monobuty1phosphate. olntomoxonh 443-2 Same as Comp. No. 4-B Same as Comp. N0. -B-l- 0.5 0. 13312 4-B3 do do 1. 0 0. 12544 (CaH17O)aP 0 011 CH170P(O)(OH)I 16640 Same as Comp. N 0. 4-0-1. 0.5 0. 18432 1.0 0.22016 J 2. 0 0. 23552 do 3.0 0.30080 4-D-1 "{DiQS-chMmethyl) phosphate (ClCH2CHzO)zP(O)OH 0 1 0 23808 M0no(B-chlorocthyl) phosphate.-. ClOHzCHzOP(O)(OII)-g 4-D-2 Same as Comp. No.i-D-l Same as Comp. No. 4D1 0.5 0.20224 do do 1. 0 0. 29932 (CmHasOhPO 1.0 0.21888 (C1sHaaO)sPO 2. 0 0.23424 d0 (C1sHs5O)sPO 3.0 0.24704 4-F-l Triphenyl phosphate- 1.0 0.3379

4-F-2 Same as above 2. 0 0. 3764 4-F-3 do do 3. 0 0. 3789 4-G-1 Tricresyl phosphate 1.0 0.3123

4-G-2 do Same as above 2. 0 0. 2726 4-G-X do (in 3. O 0. 3072 4H1 Bis(2-ethylhexy1) phosphate (CsH17O)aP(O)OH 0.5 0.2726 4-H-2 do (C5Hr70)7P (O)OH 1. 0 0. 2445 4-H-'- -do (CaH17O)zP(O)OH 2. 0 0. 2253 Control 0 0. 44032 EXAMPLE 5 Roller pins quenched with above compositions in the same manner as in Example 1 were measured to determine coeflicient of boundary friction as in Example 1 with the results shown in Table 3 below.

Thirty-two kinds of quenching oil compositions were prepared by adding zinc dialkyl dithiophosphates shown in Table 5 below in predetermined amount to 100 weight parts of mineral quenching oil the same as in Example 1.

' TABLE 3 Coeflicient Thiophosphite added Amount of boundary a e friction Comp No. Name Formula (wt. parts) (at C.)

3A1.... Phenyl dilauryl dithiophosphite 0. 5 0. 20224 3-A-2 .do Same as above 1. o 0. 17408 3-A-3 do-.. o-.- 2. 0 0. 18816 3A 3.0 0.22012 3. B1. Diphenyllauryl monothiophosphite. 0. 5 0. 35328 CnHzs S P- O 3-13-2 do Same as above 1. 0 0. 35327 3-Bi do.-- 2.0 0. 21888 3-13-4- .do .do 3. 0 0. 22528 3-0-1--. Trilauryl trithiophosphite (0|2H25S) 3P 2. 0 0. 3942!. 3-0-2 0-. (C12H25S)3P 3 0 0. 38784 Contr l 0 0. 4.4032

EXAMPLE 4 Roller pins quenched with the above compositions in the same manner as in Example 1 were measured to determine coeflicient of boundary friction as in Example 1 with the results shown in Table 5. In Table 5 the mixture described incompositidns Nos. S-C to S-E are 1:1 weight ratio mixtures of respective compounds.

TABLE 5 Amount Coeflicient Zine dlalkyl dithiophosphate added added of boundary (wt. friction Comp. No. Name Formula parts) (at 50 C.)

5-A-1 Zine (lipentyl dithiophos- C5H110 S 0. 1 0.33152 phate.

/P\ -Zn CaHnO S 5-A-9 dn Same as above 0.3 0. 19200 5 q An (in 0. 5 0.16640 5 A. 4 do do 1. 0 0. 16640 5-A5-- do an 2.0 0.17280 5 .A. fi do 7 do 3. 0 0. 20480 5B-1. Zinc dihexyl dithiophos- CQHISO S 0.05 0.41600 phate.

/P\ Zn Co iaO S 5-]3-2 I fin Same as above 0.1 0.23168 5.3 q dn (in 0.5 0.15360 4 do do 1.0 0.14208 .5 (in do 2.0 0.16728 5 B 5 fln do 3. 0 0. 17208 5 B..7 fin do 4. 0 0. 18560 5-13-51 do do 5. 0 0. 18562 Mixture Zinc dibutyl dithlophos- C4Ho0 S phate. CtHoO S 2 5-0-1- 0.1 0.41728 Zine dioetyl dithiophos- CaHuO S phate.

/P\ Zn CaHnO S a 5-0-2 Same as Comp. No. 5G-1 Same as Comp. N 0. 543-1.. 0.3 0.21888 5-0 a An rln 0.5 0.16384 5-0-4 (in 110 1. 0 0. 15372 5-6-5 fln do 2. 0 0. 17792 543. do d 3.0 0. 19584 Mixture- Zinc dihexyl dithiophos- 06BX20 S phate.

/P\ Zn CaHnO S 9 5-D1..---'.". 0. 1 0. 38656 Zinc dioctyl dithlophos- CBHIJO 8 photo.

/P\ Zn CaHnO S I 5-D-2 Same as Comp. N0. 5Dl Same as Comp No. 5-D-1.-- 0.3 0.28672 5.13:; do do 0. 5 0. 22100 4 (in do 1. 0 0. 19200 5 D..5 (In do 2. 0 0. 17280 5-.D-6 fin fln 3. 0 0. 20992 lgigtlgled ldithi h C H 0 S c propy op osx 1 r phate.

- /P Zn CsH7O S a 6-E1....'. 0. 1 0. 38400 Zinc dllauryl dithiophos- (3121126 5 phate. V A

/P\ Zn (312 25 S 2 Same as Comp. No. 5-E-1. Same as Comp. No. li-E-l- 0. 3 0. 23040 a dn 0. 5 0. 21248 fin fin 1. 0 0. 19968 fin do 2. 0 0. 14208 fin do 3. 0 0. 17152 Control 0 0. 44032 EXAMPLE 6 Roller pins quenched with the above compositions in Eleven kinds of quenching oil compositions were preg gq i i a W measured to pared by adding disulfides shown in Table 6 below in pre- 6 coe Glen 0 ary nctlon as m Example I 1 with the results shown 1n Table 6.

determined amount to 100 weight parts of mineral quenchoil the same as Example 1.

W v -.T-ABLE..6 antry... da

. 1 Coefiicient- Disulfides added m w. Amount. or'boundary, added rietion Comp. No. Name Formula v ..(wt.parts)- 011150 0.).v

6A1- Ditertiarybuty1disulfide (CH3):CSSO(CH:)3 I 0.5 0.2650 6-A-2 s)aCSSC 11m 1-. 0 o. 2057 (GHa)aCSSO (CHM 2. 0 0. 3584 CflHflS-SCBHH I 1. 0 0. 3520 d C12 25SSC1aHz5 2.0 0.3290

s-c-1.--.- Diphenyl disulfide M3408 6-0-2 do Sameasabovm. 0.5 0.38784 6-0 m--- do. I 1.0 0.40448 .1 0.33408 6-D-1 D1benzyld1sulfide- Q J Q Same as above 0.5 0.38784 do- 1.0 0.40448 EXAMPLE 7 20 EXAMP 8 Seven kinds of quenching oil' compositions were pre-- pared by adding tetraalkyl thiuram sulfides shown in Table 7 below in predetermined amount to 100 weight parts of mineral quenching oil the same as in Example 1.

Roller pins quenched with the above compositions in the same manner as in Example .1 were measured to determine coefiicient of boundary friction as in Example 1 with the results shown in Table 7 below.

Twenty-four kinds of quenching oil compositions were prepared by adding carbamate's'shown in Table 8 below in predetermined amount to 100 weight parts of mineral 3 quenching oil the same as in Example 1.

Rollerpins quenched with the above compositions in the same manner as in Example 1 were measured to TABLE 7 Coeflicient Tetraalkyl thiuram disulfides added Amount. of boundary added tnction Comp. No. Name Formula (wt. parts) (at.50 C.)

7-A-1 Tetramethyl thiuram disulfide CH; v/CH 0.5 0.2790

'lf' if* (1H3 S S I CH 7A2 on Same as above 1. 0 0. 2726 7 A 2 dn (in v 2.0 0.2221 745-1 rln 02H. can o. 5 o. 2867 il ii* (32H: S S 2 743-2.. an Sameasabovo.-. 1.0 0.3046

7-0-1 Tetramethylthiurarn monosulfideu in'u H C\ 70H; .-0.5 v 0. 2010 )N-(If.-SIZ-f%.-'-N\" w i f f 1130-... s... Ls... ..GH;.I. HI... .I. 7-0-2 do Same as above 1.0 O. 2957 Contr -0 "0.44032 determine coefficient of boundary friction as in Example 1 with the results shown in Table 8 below.

TABLE 8 .1 Coeflicient Carbamates added Amount of boundary Comp. added friction No. Name Formula (Wtparts) (at 50 8-A1 Ferric dimethyl' dithiocarbamate-... S .0.5 0.3686

. CH3 Y N- S Fe CH3 8-B-1. Oupric dlmethyldithiocarbainatmts's. I .s W, GET. H

S Cu CH3 1 8C-1.-:.. Zine dlmethyl dlthioearbamate.. CH fi 0.5 0.286!

N-C-S Zn CH3 -g 8D-1--... Zinc dlethyl dithiocarbamate.-. v 02H fi 0.5 0.3136

' NCS Zn I 01116 2 Y 8-D-2- d0 -41... "I.-. as $3665". 0 p O. 2778 8-D-3. ......d0.-. I 2.0 0.2458

TABLE 8--Continued Coefiioient Carbamates added Amount of boundary Comp. added in'ction No. Name Formula (wt. parts) (at 50 C.)

8-E1..... Zinc dipentyl dithiocarbamate C H i 0. 3 0. 40960 N-C- S Zn C5Hu 8-E-2 do--. Sameasabove 0.5 0.40832 8-E-"l doo. 1 0 0. 39296 8E4 do dn 2. 0 0. 39040 8E-5 dn dn 3. 0 0 39936 8-F-1 Cadmium dipentyl dithioearbamate- C H f! 0. 0. 34304 NC- S Cd 5 11 2 8-F- do--. Same as above 0.50 0.28544 S-F-i dodo. 1. 0 0. 28416 8-G1 Lead dipentyl dithiocarbamate C H i 1 0 0.41344 NC-S Pb a u 8-G2 do. e Same as above -r. 1. 5 0. 40704 8-G- do do. 2.5 0.37248 8-H-1 Antimony dipentyl dithiocarbamate.. C H S 0.25 0.41344 N S S b Cs n 8-H- do- Same as above 0. 5 0. 37504 8H dodo- 1. 0 0. 32768 8-H d0- do- 1. 5 0. 35200 8-H-5 dodo. 2. 5 0. 40192 8-1-1 Zinc ethylphenyl dithiocarbamatei 0. 5 0. 3418 8-1-2 4 dn e w Same as above ..z 1. 0 0. 3059 Contr 0 0. 44032 EXAMPLE 9 40 EXAMPLE 10 Seventeen kinds of quenching oil compositions were prepared by adding mercaptanes shown in Table 9 below in predetermined amount to 100 weight parts of mineral uenching oil the same as in Example 1. q Roller pins quenched with the above compositions in the a? 5 39 the same manner as in Example 1 were measured to de- Queue Hg 0 use termine coefficient of boundary friction as in Example 1 (A) viscosity 66.0 RW sec. at 0, flash point 188 C.

1.0 weight part of zinc dihexyl dithiophosphate was added to weight parts of three kinds of mineral quenching oils having the following properties to produce with the results shown in Table 9 below. (B) Viscosity 65.0 RlW sec. at 50 C., flash point 186 C.

TABLE 9 Amount Coetfieient Mercaptanes added added of boundary (wt. friction Comp. No. Name Formula parts) (at 50 C.)

9-A-1 n-Octyl mercaptane CsHnSH 0.5 0.3571 9-A- do- CsHnSH 1. 0 0.3341 9-A-4 d0- CsHnSH 2. 0 0. 3136 9-B-1 n-Dodecyl mercaptane CnHnSH 0.5 0.3712 9-B-2 (10.. CuHzsSH 1. 0 0. 3123 9-B' do. 0121125811 2. 0 0.3046 9-0-1 n-Cetyl mercaptane CmHnSH 2.0 0.41600 9-C- do-. CmHaa H 3.0 0.39296 9-D-1 Stearyl mercaptane- ClSHsaSH 0.5 0.3814 9-D-2 do 0121137311 1. 0 0. 3405 9--D-"' d0- CmHzwSH 2. 0 0. 3277 9-E- Thiflphennl 0.5 0.3098

9-E- do-- Same as above-.---.:::::::::; 1.0 0.2842 9-14] 2 dn do- 2.0 0.2405

9F1.....::...-. Benzyl mercaptane. 0.5 0.3008

CH: S H

9-F-2 do- W Same as above .;.'......;;...s 1. 0 0.2624 9F-'* d0- 6.0- 2. 0 0. 2458 Contr 0 0.44032 15 (C) viscosity 775.8 RlW sec. at 50 C., flash point 282 Roller pins quenched with the above compositions in the same manner as in Example 1 were measured for coefiicient of boundary friction as in Example 1 with the results shown in Table 10 below.

EXAMPLE 1 l Bolts made of chromium steel (SAE 5140), 10 mm. in diameter, 27 mm. in length and 1.25 in screw-thread pitch, were heated at 850 C. in nitrogen gas atmosphere and were immediately immersed respectively for minutes in three kinds of the present quenching oil compositions. The resultant cooled bolts were again tempered in a nitrogen gas atmosphere at 500 C. for 2 hours, and respectively immersed in the above quenching oil compositions for 5 minutes.

The fastening force and the fastening torque were measured by a strain gauge with respect to the above resultant bolts to determine the relation therebetween. The results are shown in Table 11, in which the same composition numbers as those in Tables 1 to 9 refer to the same compositions.

TABLE 11 Forces (ton) Torques (kg.-cm.)- 500 600 700 800 900 As apparent from the foregoing examples, the compositions of the present invention obtained by adding specific compounds included in the groups (I) to (IX) to quenching oils of mineral origin can impart lubricity to quenched metals. None of these compounds will exert any adverse effect on the inherent properties of the quenching oils, provided they are added to the quenching oils in the amount of 0.05 to 5 weight parts based on 100 weight parts of the latter. This is clarified in Table 12 showing the cooling ability of the typical compositions of the present invention as measured in accordance with the method provided in HS K 2526. The quenching oil used in this test was the same as that in Example 1, the same compositions as those in Tables 1 to 9 being referred to by the same numerals.

What we claim is:

1. A method of simultaneously hardening metal and imparting excellent lubricity to the metal surface which comprises quenching said metal in a quenching oil composition which comprises a mineral quenching oil in major amounts and 0.05 to 5 weight parts, based on 100 weight parts of mineral quenching oil, of at least one zinc dialkyl dithiophosphate having the formula of:

wherein R is an alkyl of 1 to 12 carbon atoms.

2. The method of claim 1 wherein the zinc dialkyl dithiophosphate is at least one species selected from the group consisting of zinc dipropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc dipentyl dithiophosphate, zinc dihexyl dithiophosphate, zinc dioctyl dithiophosphate and zinc dilauryl dithiophosphate.

3. The method of claim 2 in which the zinc dialkyl dithiophosphate is zinc hexyl dithiophosphate.

References Cited UNITED STATES PATENTS 2,316,080 4/1943 Loane et al 25246.6 X 2,536,403 1/ 1951 Wallace et a1. 252-32.7 HC X 3,361,668 1/1968 Wiese 25232.7 E 3,657,640 3/1971 Stroh 252-59 OTHER REFERENCES Gruse et al.: Chemical Technology of Petroleum, 3rd ed. (1960), pp. 525-532 and 537.

Handbook of Chemistry and Physics, Rubber Pub. 00., 44th ed. (1962-1963) p. 2252, viscosity conversion graph.

DANIEL E. WYMAN, Primary Examiner W. H. CANNON, Assistant Examiner US. Cl. X.R.

148-18, 29; 252r32.7 HC,