6276
Vol. 74
NOTES 1'ALII.E I RESULTSU F \YEAR ~ L W A S C R E ~ ~ I S N T S USING TiiE SHELLITOURl3~i.1,\{'EAR TESI'ER
Steel ~
- Steel--
5 kg.
Oil Load
hl.ctliylsilicone h l c thyl-~-chloropheiiylsilico~ic hlethy 1-m-chloropheuylsiliconc
-----
10 kg.
20 kg.
nil
~
-
-
-
5 kg.
Iioorn teinpcrature, 1 hour a t GOO r.p.ni. 0 . 3 3 niiii.n 0.49 iiini. .. 0.59 1 m i . .21 . 33 .. .42 .. .35 0.53 .. Room Temperature, 1 hour a t 1200 r.p.ni.
10 kg.
.... -.. 20 kg.
2 . 3 3 inin. 0.60 .39
!1.60
Brass
~
Methyl-m-chlorophen ylsilicone 0.41 0.49 .. 0.42 0.59 " Average diameter of wear scar, in inm., oil the three stationary balls in the Shell Four Ball Wear Tester.
cyclotrisiloxane was isolated from the hydrolysis product of metliyl-~-chlurophenyldichlorosilane. The chlorophenyl-containing organopolysiloxanes were prepared by the reaction of hexamethyldisiloxane and methylchlorophenylpolysiloxanes in the presence of sulfuric acid. It was of interest to note that only negligible cleavage of the chlorophenyl-to-silicon bond occurred during the equilibration reaction whereas extensive cleavage of the phenyl-to-silicon bond occurs under similar conditions in plienylsiloxanes. I t has been found that when these chlorophenylcontaining organopolysiloxane oils are used as lubricants they reduce the wear of steel and brass bearings over that obtained by use of the conventional methylsilicone oils. The oils were evaluated on the Shell Four Ball Wear Tester and the results of these tests are given in Table I. Experimental moles Methyl - p - chlorophenyldichlorosilane. --Three (374.5 9.) of p-chlorobromobenzene and 7 2 g. ( 3 moles) of 1.iof anmagnesium turnings w a e allowed t o react in 1 .. hydrous ether. After the reaction had proceeded to completion the ether solution of p-chlorophenylmagnesium bromide was added slowly with stirring to 470 g. of methyltrichlorosilane in 1 1. of anhydrous ether. After complete reaction had been effected the ether was stripped from the reaction flask and chlorosilanes were recovered by a very rapid vacuum distillation. By use of an efficient rectification column 197.2 g. of methyl-p-chlorophenyldichlorosilane, 11.p. 161-164° (99-100 mm.), was recovered (34% yield!. Anal. Calcd. for C7H7SiCls: C1 (hydrolyzahle), 31.4.4. Found: C1 (hydrolyzable), 30.9. Methylbis-p-chlorophenylchlorosilane.--The low yield of methyl-p-chlorophenyldichlorosilane is due in part to thr formation of mcthylbis-p-chlorophenylchlorosilane. In a sccond preparation of nictiiyl-p-chlorophcnvldichlorosilati(, !1 moles of p-chloritl~rornobr~i~c~~e was used. 1:roiii this run it was possible to separate cleanly methylbis-P-chlorophenylciilorosilane from thc high boiling residuc, h.1). 187' ( 5 111111. 1.
. 1 ?tal. Calcd. for CI.HIISiCla: C1 (hydrolyzable), 112 1 ) ; Cl (total), 33.59. Found: C1 (hydrolyzable), 11.5, 11.5; CI (total), 31.5, 34 .O, 33 .e, 33.3, 33.1. Methyl-m-chlorophenyldich1orosilane.-To a mixture of 111 g. of magnesium turnings in 3 1. of anhydrous ether wiis ;itldetl dropwise 1000 g. of in-bromochlorobenzene. \\-hen the re:rctioti had run to completion the solution of the Grigturd reagent was added dropwise with stirring, to a solution ( I F 1000 g. of methyltrichlorosilai~cin ,500 ml. o f anhydrotic ivther. Ihtillation of the reaction product gal j yicld 1I ,670) of i~ictliyl-~~i-chlc~rophenyldich!oro i T , ( I o tril imn.i. .1nu1. C:iIcd. for C7H7SiCI:: C1 (hydrolyzal)le'i, : : I . [-I: ('1 (total), 47 l i i Voiind: c'1 (1ivrlrolyz;~hlci. ::I .2; ('I i tot;.1l 1, 47.11. .- .. , I ) !\'
I
FaLni~
