Patented Sept. 4, 1951 ... ??? .. 2,566,956 UNITED STATES PATENT office

George Wesley Pedlow, Jr. and Carl Shelley. Miner, Jr., Evanston, Ill., assignors to Minne sota Mining & Manufacturing Company, St. Paul, Minn., a corporation of Delaware Application December 31, 1942, Serial No. 40,904 1 Claim. (Cl. 260-4488) 1. The present invention relates to organic silicon It will be noted that this procedure does not yield Compounds and to products or articles involving 'an alkoxy silicane, nor an alkoxy chloro sili the same, and to methods for producing such cane; rather it yields an alkyl silicane or an alkyl Compounds. chloro silicane, such as: - Certain of the organic silicon compounds in s C question may be regarded as silicon tetrachloride, \sic, SiCl4 (which is derivable from silica, SiO2), in which at least one of the chlorine atoms is re ' ... - ??” placed by an organic radical, particularly an in which the carbon atom of the alkyl group alkoxy radical, yielding, compounds such as (or of an aryl group) is joined directly to the sili ... (RO)2SiCl2 and where the compounds in ques con atom; whereas in alkoxy silicon compounds tion have certain special properties and novel there is an oxygen atom intervening between the '-characteristics and/or are adapted for new and carbon atom of the alkyl group and the silicon valuable uses. The invention as a Whole will atom, which materially alters the nature of the be more fully explained hereinafter. 5 product:: - Further, the Grignard reaction is very Heretofore others have produced certain or expensive and hence unsuitable for ordinary large ganic silicon containing products, starting with scale commercial operations, at least in many silicon tetrachloride, SiCl4. Silicon tetrachloride cases and, in fact, in most cases unless magne is a chemical product which has long been known. sium becomes much cheaper. This reaction also - It can readily be produced in different ways in 20 involves the use of large volumes of anhydrous cluding, by blowing chlorine through a tower ‘ether, which is not only expensive but is hazard packed With Sand and coke and of Controlled tem ous and difficult to handle. -" ' ? - - - - - .. `? •?’ - - …. perature and other conditions. Thus silicon tet Another procedure which has been tried is the rachloride is a readily available material. Wurtz Reaction, an ordinary application of which One material which has been known for quite 25 -Some time, and which is derivable from Silicon C tetrachloride, is ethyl orthosilicate, i. e. CH,Cl + 2Na + C-de-CI – CH-SiC), + 2NaCl . which may also be referred to as tetra-ethoxy That is, phenyl chloride (otherwise known as silicane. This can be produced by the reaction 30 chloro benzene) plus silicon tetrachloride plus of silicon tetrachloride and ethyl under sodium will (to some extent) tend to yield phenyl certain conditions, so that the ethoxy radical trichloro silicane plus Sodium chloride. replaces the chlorine and HCl is evolved. This However this reaction, where it is desired to ... reaction has not proved too difficult because the replace part of the chlorine atoms of silicon tet hydrogen chloride does not react readily with 35 rachloride with phenyl or other aryl or alkyl ethyl alcohol. In fact, HCl does not react readily groups, tends...to result in a mixture of all pOS with primary alcohols in general. sible phenylor other arylor alkyl Substituted.sili However hydrogen chloride is quite reactive canes. There is also a tendency for the phenyl with other alcohols; and this fact has interfered chloride, or equivalent, in the presence of sodium, with the production of interaction products of 40 to produce diphenyl, or equivalent, which fur silicon tetrachloride and alcohols, excepti for pri ther detracts from the practical worth of such a mary alcohols. For example, see “Alkyl Ortho process. For example, in endeavoring to pro silicates' by A. W. Dearing and E. Emmet Reid, duce Phi2SiCl2, i. e. diphenyl, dichloro silicane, we Journal American Chemical Society, vol. 50, have found that it is difficult to secure a yield 1928, page 3058: The writers tried one secondary better than 15-20 percent. -- alcohol, i. e. , but were unable The Friedel-Crafts type of reaction may also to produce an alkyl silicate of any kind this way; be considered. A typical Friedel-Crafts reaction so they otherwise employed only primary alcohols is: ------in their work. Alcohols other than primary alco 50 , " Al Cla hols have a natural tendency to form the corre * 3. - ?? + C2HC1 --> CH3-C2H5 -- HCl sponding alkyl chloride and SiO2 when it is at It might also be assumed that the following re tempted to react such an alcohol with silicon action will occur, but it has not been successfully tetrachloride. completed, insofar as we are aware: Other procedures have been employed in at SS - Al Cls tempts to produce certain so-called organic sili | 3. CBI : --; SiCl4 ----» : CHSiCls - HCl ...... con-containing compounds. Thus the Friedel-Crafts reaction appears un one such procedure (which has advantages for workable in this connection, the Wurtz reaction certain purposes) involves the use of the Grig appears, impractical from the point of view of nardtion, noteEugenereagent. For G. example, Rochow as Patent a general No. 2,258,218.0 illustra many commercial conditions, and the production 2,566,956 3 of normal alkoxy silicanes such as tetra-ethoxy has the unique characteristic of having alkoxy Silicane appeared unpromising because of the in groupS attached to Silicon, Where the compound stability of such products toward hydrolysis. Of itself is resistant to both neutral and alkaline hy the various reactions and products above dis drolysis. Compounds of this character, upon cuSSed, the Grignard reaction and the products 5 heating to moderate temperatures, above the produced thereby (having a carbon to silicon, . respective melting point of each, Will polymerize -C-Si-, linkage), in Spite of the high cost to form resins Which may be controlled to a clear of Such reaction, apparently appeared most colorleSS, Water-resistant fusible character. prOImiSing: See Eugene C. Rochow PatentS NoS. The tern alkoxy Silicane is used herein to des 2,258,218, 2,258,219, 2,258,220, 2,258,221 and O ignate compounds in which at least one of the va 2,258,222. lences of Silicon is taken up by an alkoxy group We have, however, discovered an important and the other Valences may be Satisfied by one or class of organic-silicon compounds which do not more groupS Or atoms Such as chlorine, oxygen, have molecules with a carbon to silicon linkage, hydroxyl, amino, alkoxy, alkyl, aryl, etc. and furthermore which have a carbon-oxygen Insofar as We are aWare no one prior to Our Silicon (-C-O-SI-) linkage and yet do not invention ever produced an alkoxy Silicane or have the short-comings. of normal alkyl ortho other organic-Silicon compound of any type (e.g. Silicates, Such as ethyl orthosilicates (also re an alkoxy chloro Silicane) Which could be hy ferred to as tetra-ethoxy silicane). We have drolyzed to produce a compound having alkoxy also found that we can produce organic-silicon groupS attached to Silicon, Which latter compound compounds, e. g. starting with Silicon tetrachlo is resistant to neutral and/or alkaline hydrolysis; ride (SiCl4), in which only a portion, e. g. two, neither has there ever been produced, insofar as of the chlorine atoms are replaced by alkoxy We are aWare, an alkoxy Silicane containing one groups. This we have been able to accomplish or more other groups or atoms (in addition to the by employing a tertiary alcohol, e. g. tertiary : 5 tert-alkoxy group or groupS), and Which corn butyl alcohol or tertiary-amyl alcohol, for reac pound is stable to Ordinary neutral or alkaline tion with Silicon tetrachloride (under particular hydrolysis. conditions which avoid the undesirable produc Saying Somewhat the Same thing in other tion of tertiary-butyl chloride, or the like, plus Words, insofar as We knoW no One prior to our SiO2). Insofar as we know, no one prior to our 30 invention ever produced an alkoxy chloro Silicane invention has ever reacted a tertiary alcohol with in which the chlorines can be removed by hydrol silicon tetrachloride; or produced organic silicon ysis, e.g. by alkaline hydrolysis, using an alkaline compounds such as we have been able to produce. material, Such as ammonia, or pyridine, which is We have furthermore, been able to carry out our soluble both in Water and in the alkoxy chloro operations with good yields (e.g. 80 percent or Silicane, where the alkoxy groups are stable, i. e. better). So as to replace two chlorine atoms of 35 unaffected by such hydrolysis. the silicon tetrachloride, instead of all four chlo It is an object of Our invention to produce al rine atoms, as in the making of ethyl orthosili koxy silicanes, especially tertiary-alkoxy sili cate, (C2H5O)4Si. By employing different condi canes, of the type above indicated, which can be tions we can also replace either one or three chlo 40 hydrolyzed to produce the corresponding alkoxy rine atoms, as desired. ... silicanes which are resistant to neutral and/or We have produced various compounds of the alkaline hydrolysis. It is also an object of our type just referred to, including, for example, di invention to produce alkoxy Silicanes, having tertiary-butoXy dichloro silicane, one or more other groups attached to Silicon in addition to the alkoxy group or groups, which ((CH3)3CO)2SiCl2 compounds are stable against neutral and alka di-tertiary-amoxy dichloro silicane, line hydrolysis. It is also an object to provide resins, as above indicated, by polymerizing the type of compound last-mentioned. Employing compounds as above indicated, e. g. di-teritary CHV 50 alkoxy dichloro Silicanes, as intermediates and and bis (di-chloro-tertiary-butoxy) dichloro producing other compounds and/or treated arti silicane. cles therefrom, and such resulting compounds and/or treated articles, constitute further ob jects and advantages hereof. These and other These compounds can be hydrolyzed under con 55 objects and advantages will appear from the de trolled alkaline conditions, e. g. in the presence Scription taken as a whole. V of aqueous ammonia or aqueous pyridine, to re Illustrative and advantageous procedures for move the chlorine atoms and to yield an alkoxy preparing our tertiary-alkoxy chloro silicanes Silicane which latter is resistant to neutral or Will now be given. However, it will be under alkaline hydrolysis. The last mentioned com (50 stood that our novel products are contemplated pound may be a di-tertiary-alkoxy di-hydroxy irrespective of the particular method of produc silicane, [(CH3)3CO)2Si(OH)2 or some varia tion described. tion thereof. In some cases said compound, de pending on the manner-of-hydrolysis, may have Process for the manufacture of di-tert-amoa a molecular formula of generally the following 65 - dichloro silicane fype: , . Materials to be employed and proportions: ((CH3);? old-o-do ?(CH)] Matecial Weights Moles Another possible structure, depending upon con ?? Paris ditions of hydrolysis, is Silicon tetrachloride------50 3.00 fyridine------498, 6.33 - - - ((CH3)3COlsi=o Tertiary-amyl-alcoho 528 6.00 Benzene (assolvent)--- 1,050 ------?? - Whatever the exact molecular structure of this Benzene (for washing C5H5N·HCl) ------1?------!? 100 compound in any particular case, the compound is 6 the benzene and silicon tetrachloride are by weight (85% of theoretical yield) of di-tert placed in the reaction vessel, preferably glass amoxy dichloro silicane is obtained. lined, and cooled to about 10° C. by means of brine In the preparation of di-tertiary-butoxy di or other heat exchange medium. While Stirring chloro silicane the process is substantially iden the solution, the pyridine is slowly added, the tical with that above described except that 444 temperature being kept below 20 C. during the parts by Weight (6.0 mols) of tertiary-butyl addition. The addition of the pyridine requires alcohol are used in place of 528 parts of tertiary a substantial period of time, e. g. from 1 to 2 amyl alcohol above indicated. The boiling point hours, depending on the efficiency of the cooling of the di-tertiary-butoxy dichloro silicane is system. Throughout the entire addition the O 66° C. at 11 mm. absolute pressure. pyridine and silicon tetrachloride react to form Similarly, dichloro-tert-butyl alcohol, 1-ethyl a white precipitate which toward the end forms , dihydroterpineol, terpineol and a fairly thick paste with the benzene. The for linalool react with silicon tetrachloride in the mation of this white precipitate on the Walls of preSence of pyridine, yielding respectively; bis the reaction vessel as a result of the interac 5 (dichloro-tert-butoxy) dichloro silicane, B. P. tion of the vapors of the reactants can be reduced 173-6° C. at 10 mm.; bis (1-ethylcyclohexoxy) to a minimum by having the pyridine inlet extend dichloro silicane, B. P. 170—3° C. at 5 mm.; bis to within a few inches of the surface of the ben (dihydroterpineoxy) dichloro silicane, B. P. zene. After addition of the pyridine is complete 195 C. at 7 mm., and diterpineoxy and 20 dilinalooxy dichloro silicanes which latter two the mixture is stirred, e.g. an additional 15 min compounds could not be distilled without decom utes,The more tert-amyl Or leSS. alcohol is then ?* added,* * ? ? ? all? ? ? at position at 5 mm. pressure. The average yield once. The temperature rises slowly at first, but was about 75-80% of the theoretical in all cases. once above about 30° C. it rises rather quickly. Procedure for making tri-tertiary-butoacy chloro Unless the dimensions of the reaction vessel are 25 Silicane sufficiently restricted, it is desirable to employ internal cooling coils or elements, so that loss of One method of making this compound will be material due to overheating will be avoided. It briefly described. has been found convenient to allow the tempera A solution of 98.0 parts of di-tert-butoxy di ture to rise to about 40-45° C. then, by controlled 30 chloro Silicane, 31.6 parts of pyridine and 75 parts cooling, it is kept at this temperature until the of tert-butyl alcohol was allowed to stand in a reaction subsides. This requires about 1.5 to 2 closed container for 72 hours or until the pre hours, more or less. The mixture is then heated cipitation of pyridine hydrochloride ceased. The slowly over a period of about 45 minutes to reflux mixture was then filtered, the precipitate washed temperature. The slow heating tends to form with benzene, and the filtrate fractionally dis a granular pyridine hydrochloride which lends tilled. Tri-tert-butoxy chloro silicane (55 parts) itself well to subsequent filtration. Refluxing is was collected at 76° C. at 7 mm. pressure. then continued for about two hours, to insure Process for making tertiary-butoacy trichloro completion of the reaction. It is then cooled and silicame filtered to remove the pyridine hydrochloride, re .it) covering both the filtrate and filter cake. What In One method of making tert-butoxy trichloro is ordinarily a very slow filtration can be accom silicane 37 parts of tert-butyl alcohol were added plished quickly by forming a bed of a filter-aid to the reaction product of 39.5 parts pyridine and such as 'Filter Cel' or “Super Cel' on the filter 85 parts of silicon tetrachloride in 250 parts of ing medium, such as cloth. This can be done by Solvent. The reaction was carried out in essen suspending 15-20 parts of the filter-aid in 200 tially the same manner as described hereinabove 300 parts of benzene and filtering this suspen for the preparation of di-tert-amoxy dichloro sion through the filtering apparatus. The ben Silicane except for the proportions of reactants zene can be used later for washing purposes. The as indicated. Upon working up the products the pyridine hydrochloride is substantially free of yield of tert-butoxy trichloro silicane averaged filtrate and then Washed with benzene until Sub about 38% of the theoretical in several runs. In stantially free of the di-tertiary-amoxy dichloro these runs variations in time, temperature and silicane product. solvent seemed to have little effect on the yield The filtrate and washings are combined, and of product. the benzene is distilled off at atmospheric pres The above procedure was less satisfactory for sure. When there is no further benzene distill the making of tertiary-amoxy trichloro silicane. late the product is cooled and the distillation We found, however, that by changing the order of continued at reduced pressure, e. g. an absolute addition of the reactants we got materially im pressure of 10 to 100 mm., to separate the di-ter proved yields of tertiary-alkoxy trichloro sili tiary-amoxy dichloro silicane product from re 60 canes. This improved procedure will now be de maining materials (i.e., products of side, react Scribed. tions, impurities, etc.). The product decomposes Improved process for the manufacture of ter when distilled at atmospheric pressure. A glass tiary-butoacy trichlorosilicane lined still, suitable for vacuum distillation, may be employed for both the distillation at atmos 35 This method involves the slow addition of a pheric pressure and the subsequent distillation at mixture of 37 parts (0.5 mol) of tertiary-butyl reduced pressureS. alcohol and 39.5 parts (0.5 mol) of pyridine to a After a Small amount of low boiling material Solution of 200 C. C. of petroleum ether (boiling (mostly benzene) is removed in the vacuum dis range 35-60° C.) and 85 parts (0.5 mol) of silicon tillation, the major portion of the product boils 70 tetrachloride, cooled to about 17 C. The mix at 105° C. at 22 mm. absolute pressure. The dis ture was kept at this.temperature during the ad tillate is sometimes cloudy with pyridine hydro dition which required five (5) hours and then it, chloride, but this settles out on standing and has was heated to 30° C. over a four (4) hour period. proved to be of no consequence when the prod The reaction mixture stood overnight and was uct is used in other reactions. About 700 parts then stirred for five (5) hours at 30°C., filtered 7 8. and the product distilled. 71.5 parts (0.39 mol) may be prepared by the addition of a mixture of tertiary-butoxy trichloro silicane (B. P. 70-C. pf tertiary-butyl alcohol and pyridine to silicon at 87 mm.) was obtained, representing a yield of tetrachloride in a suitablesolvent. - 69% of the theoretical. The temperature of the reactions in the herein This improved method, when applied to the above examples can be varied. Although reac preparation of tertiary-amoxy trichloro silicane tion takes place between silicon tetrachloride, and (B.P. 78° C. at 55 mm.), resulted in a 79% yield tertiary alcohols in the presence of pyridine at of this compound. This is an outstanding im low temperatures it proceeds only slowly below provement in yield of this compound over that 30° C. The rate increases rapidly as the tem obtained with the procedure first discussed for 0. perature is increased above about 30° C. and is making tertiary-alkoxy-trichlorosiilcanes. very fast at the boiling point of benzene. The En respect to proportions of reactants-employed preferred temperature for the preparation of di in the procedures for making tertiary-alkoxy tertiary-alkoxy dichloro silicones is 45+10° C, strichlorosilicanes, and comparing them with the since in this range of temperatures the rate of hereinabove described procedure for making di s reaction is satisfactory and at the same time tertiary-alkoxydichloro silicanes, it will be noted the reaction can be easily controlled. The ithat the difference does not consist in simply amount and time of heating of the reaction mix lowering the proportion of alcohol to the silicon ture after all of the ingredients are present tetrachloride, but, however unexpected it may depend largely on the rate of reaction and are Seen, it is also very important that the propor 20 not limited to the time and temperature given tion of pyridine to the silicon tetrachloride be in the hereinabove examples. lowered, as illustrated by the proportions given As hereinabove indicated, the alkoxy chloro in the respective examples. silicanes described and illustrated hereinabove This was shown by the observation in the above may advantageously be employed as interme improved process for preparing tertiary-butoxy 25 diates in making other materials. A very brief trichloro silicane, that if double the quantity of skeleton outline of such derivative materials, pre pyridine Were used (the quantities of otherma pared by us, is appended hereto as a drawing, to terials and the conditions were otherwise the be made a part of this, application. It will be Same), no tertiary-butoxy trichloro silicane was understood that this skeleton outline is not in obtained, but instead di-tertiary-butoxy dichloro 30 tended to be in any way comprehensive, but Silicane Was produced in a theoretical yield of simply illustrative, and an aid in understanding -87% based on the quantity of alcohol used. In certain of the products produced in their general .this example approximately half of the silicon relation to each other. It will be noted, for ex -tetrachloride did not enter at all into reaction ample, that the skeleton outline shown in the With the tertiary-butyl alcohol. 35 appended drawing is all prepared on the basis It will be understood that the hereinabove ex of compounds derived from tertiary-butyl alcohol amples are intended to be illustrative only, and With the other reactants. A generally analogous that the invention is generic to the process outline could be prepared with compounds de wherein a tertiary alcohol is caused to react with rived from tertiary-amy alcohol and other ter silicon tetrachloride in the presence of pyridine tiary alcohols, of which several other illustrations and/or with the reaction product of pyridine and are given hereinabove. It will also be understood silicon tetrachloride or With a tertiary-alkoxy that where the compounds di-tertiary-butoxy trichloro silicane, or a di-tertiary-alkoxy dichloro dichloro silicane or tri-tert-butoxy chloro sili Silicane in the presence of pyridine. The groups cane are shown that we also comprehend com attached to the carbinol carbon may be aliphatic pounds which contain unlike alkoxy radicals or 'aromatic; if aliphatic, they may be saturated 5 Such as tertiary-butoxy tertiary-amoxy dichloro gor unsaturated, and if cyclic, they can contain a silicane, tertiary-butoxytertiary-amoxy dichloro hetero atom Such as oxygen, in the furan ring or tertiary-butoxy chloro silicane, etc. sulfur. in the thiophene ring. They can be sub Additional products comprehended herein are Stituted by additional groups which are unreac those derived by reaction of silicon oxychloride tive toward Silicon tetrachloride such as halogen, With tertiary alcohols. in the presence of pyridine. nitro, alkoxy, or acetoxy. If aromatic, they can Silicon oxychloride, Si2OCls, is an intermediate also be Substituted with additional groups unre in the formation of silicon tetrachloride and active toward silicon tetrachloride such as alkyl undergoes the same general type of reactions as or any of the:groups described above. the latter. For example, by reaction of this mate The solvent used for the reaction must be; sub rial with tertebutyl alcohol in various amounts stantially inert to reactants and its properties a number of new products may be prepared of should be. Such that it can be readily separated which the following are examples: from the product. Such solvents includealiphatic or aromatic hydrocarbons, ethers and cyclic I. Sym-tetra-tert-butoxy dichloro siloxane. ethers, etc., as well as their halogenated deriva 60 II. Di-tert-butoxy tetrachloro siloxane. tives. In some cases it may be desirable to use III. Penta-tert-butoxy chloro siloxane. one of the reactants as a solvent, e.g. pyridine Hydrolysis of I with aqueous pyridine yields tetra or other tertiary-amine as Well as tertiary-butyl tert-butoxy dihydroxy siloxane which latter is alcohol or other tertiary alcohol may be used. 65 also obtained by hydrolysis of di-tert-butoxy However, in general the lower boiling hydro dichloro silicane under special conditions. Hy carbons are preferred because of their low cost, drolysis of II with aqueous pyridine gives: a resin, the ease with which the pyridine hydrochloride which is quite similar to the hereinbelow described can be removed from them by filtration, and resin obtained by the hydrolysis of di-tert-butoxy also the fact that they can be readily separated 70 dichloro ?silicane. - from the product by distillation. Compounds which distinguish over the prior The order of addition of reactants in many art in a manner parallel to or analogous to the cases (particularly in the preparation of "di distinctions possessed...by the silicon compounds tertiary-alkoxy dichlorosilicanes) is not a critical point, : e.g. di-tertiary-butoxy dichloro silicane s groups.herein illustrated,III. to IV of butthe whichperiodic contain table othera metal than of

3,566,956 ? 11 12 - Nam? Formula Physical Constants Analysis Appearance. D???-but?y Diacetoxy Sill- (s-Buoyst(?????): - - - - - 2.go C.7 mm, not Acid No. 374, Cale,854. Limpid liquid. Dimethyl Dilinaloyl Silicate. (CHO)2Si(CoH17O2------| b. p. 177—8° C./7 mm.-.-.-.-.-.-.- SiO2.5.0, Theory 15.2 siä:äy viscous DiethylDiterpinyi silicate. (??,???»si(C????». b.???-300' c.6 mm., np2 | SiO2 14.2, Theory 14,1- ID?. Bis(4-acetoxy-2-methyl-2- (CH3O)2Si(C8HisO3)*------b. p. 163-6' C.|5 mm., nD20 | SiO2 14.8, Theory 14.7. Do. pentggy) IQirrethoxy. Silic?rne. , 1.4262, ...... - - - B????? methyl) Dimethyl (CH3O)2SiOC(CH)3'------b. p. 205-8° C.|5 mm------| SiO2 10.7, Theory 9.9. Do. Biscathyl-2,4-pentanediol) (CeBaO2)2Si------b. g-10 C./9 mm., f. p. sig2804, Theory White crystals. . . Isopropyl orthosilicate------(CH3)2CHO4Si------b.p.59°C.f4 mm., nD201.3855. SiO2 20.8, Theory 20.8- Limpid liquid. CH Di-sec-butoxy-dichloro Silicane (??,??????????? ? - ? - ? - ? - - ' b. p. 93-95° C.I22 mm------Cl 26, Theory 29------Fuming liquid. - In the above table where an asterisk occurs be of these resinous materials. For example, a crude. side the indicated formula of a compound, this has di-tert-alkoxy dichlorosilicane may be hydrolyzed been done because we do not feel that we have suf 20 directly in the original reaction mixture with no ficient evidences as yet to be sure that this is necr preliminary purification of this mixture. This essarily the correct formula. In the case of some may be accomplished by adding to the crude re Of the formulae given it is to be understood that action mixture the required amount of a basie the actual molecular weight may be represented material, Such as Sodium carbonate dissolved in by that indicated by the formula, when multiplied water. The Organic layer is then separated, the by some integral number in excess of 1; that is Solvent renewed by distillation and the product the compound itself is a polymer. In certain cases. heated until the desired degree of hardness is at In respect to some of the compounds, because ..' tained. of the complexity of their formulae, it is doubtful. However, the use of a di-tert-alkoxy dichloro whether it will ever be possible to accurately prove 30 silicane which has been previously purified by dis their chemical structure; however, it is believed tillation is preferred because of the improved to be helpful to indicate what their structure control over the purity and properties of the final probably is, based upon such data as we have, resin. The following example will serve to illus and in any event there is considerable certainty trate a preferred procedure for the preparation about certain characteristics of the molecule, or of a resin from dirtert-amoxy dichlorosilicane. functional groups, which is the important thing In a suitable reaction vessel is placed 150 parts in determining the reactivity, stability under vari of concentrated aqueous ammonia. The am ous conditions and like characteristics, of the . . monia solution is cooled to 15-20 C. and with product. good agitation 68 parts of distilled di-tert-amoxy In the making of various derivative products dichloro Silicane, B. P. 105 C./22 mm., is gradual from tertiary-alkoxy chloro silicanes, for exam 40 ly added over a 30 minute period keeping the tem ple as indicated in the attached drawing, and . perature at 15-20 C. Agitation is continued for also in the table presented hereinabove, it is im 15 minutes. The layers which have formed are portant to note that in many cases purification of Separated and the aqueous layer extracted with the tertiary-alkoxy choro Silicane is not neces benzene, which is then added to the oil layer. . . . . sary and that the derivative may be made direct-4 The benzene solution of the product is filtered ly, often even in the same reaction vessel, with to remove traces of solid impurities. The filtrate is the crude tertiary-alkoxy chloro silicane. To then distilled at atmospheric pressure until all illustrate, the crude di-tertiary-butoxy dichloro of the benzene is removed. The product is then silicane. (which is made up i of about 85% di heated, the time and temperature of the heating tertiary-butoxy dichloro silicane) may be react being determined by the properties desired in the ed directly with allyl alcohol and pyridine to final resinous product, which may vary from a produce di-tertiary-butyl diallyl silicate (about viscous oil through a soft, tacky resin to a hard 73% yield); or with acetic acid and pyridine to and brittle resin which may be either fusible, or produce di-tertiary-butoxy diacetoxy silicane infusible. For example, the product of the above (76% yield); or with diethylene glycol and pyri 55 reaction was heated at atmospheric pressure at dine to produce di-tertiary-butyl (diethylene gly- , 245-55° C. for 30 minutes and then at the same - eo) silicate (90% yield) ; etc., the ultimate proå- . temperature at 30 mm. pressure for 1 hour. At uct in each case may then be purified as desired. the end of this treatment the product (37.4 parts) As already indicated, one of the important uses was still fluid before cooling, but at room temper of alkoxy chloro silicanes is as intermediates in 60 ature it was a clear, almost colorless, hard and the production of other products or as reactants. - brittle resin. Analysis of this sample gave a value - or treating agents in the production of improved for silicon of 18.5%. articles. Procedures involving such use of ter The conditions of time and temperature in the tiary-alkoxy chloro silicanes, and the ultimate hydrolysis of the di-tert-amoxy dichloro silicane products resulting therefrom will now be de 65 may be varied greatly from those indicated in 2 seribed briefly. ... the preceding example. For example, such a hy drolysis has been successfully carried/ out at 70° Production of a resin from di-tertiary-butory .. C. The time in any case need only be sufficient dichloro silicane to assure completion of the hydrolysis which oc When - dialkoxy - dichloro silicanes and/or al 70 curs much more rapidly as the temperature is in koxy trichlorosilicanes are hydrolyzed in the pres creased. - ence of an acid acceptor, and the hydrolysis prod Resins of the type hereinabove indicated may ucts therefrom are further heated, the end... also be prepared by an indirect procedure involv products obtained are of a resinous nature. Vari ing the conversion of a di-tert-alkoxy dichloro Ous methods can be employed for the production 5 Silicane to a di-tert-alkoxy diamino silicane by 2,566,956 13 14 reaction of the former with anhydrous ammonia. The liquids and crystalline solids hereinabove de The di-tert--alkoxy diamino silicane may be hy scribed and derived from the tert-alkoxy chloro drolyzed by water alone, the product is then sep silicanes are useful as plasticizing agents for, na arated and heated as in the preceding example. tural and/or synthetic resins such as cellulose Tert-alkoxy trichloro silicanes are even more esters and ethers or the silicon resins herein des readily converted to resins than the di-tert-al scribed. They may be used alone or in admixture koxy dichloro silicanes. For example, water is With other plasticizers known to those familiar gradually added to a cooled pyridine solution of with the art. They may be used as ingredients in tert-butoxy trichlorosilicane to hydrolyze the lat extreme pressure lubricants and are also appli ter. The product is extracted from the aqueous O cable as paint media or as ingredients in Waxes layer by means of a suitable solvent such as ben and polishes. The resinous products derived from zene. Evaporation of the solvent leaves a clear, tert-alkoxy chloro silicanes are useful as Water colorless, brittle resin which is similar to the more proof coatings for wood, metal, paper, etc., either brittle of the resins derived from the di-tert-al alone or modified with plasticizers or other plas koxy dichloro silicanes. Other generally parallel ls tics. They are also useful as ingredients in ad reactions and parallel types of products may be hesives, paints and lacquers. prepared by starting with a different specific ter Di-tertiary-butoxy diacetoxy silicane and an tiary-alkoxy chloro silicane, and a whole series of alogous compounds may be made in generally the such resins may be produced by employing dif same manner as is indicated in connection with ferent alkoxy chloro silicanes. This is somewhat 20 the orthosilicates except that the appropriate or indicated in the skeleton outline shown in the ganic acid is employed along with the tertiary attached drawing and is further indicated by the alkoxy chloro silicane and pyridine. As an alter other particular tertiary-alkoxy chloro silicanes native method, these products may be prepared shown in the table presented above. by the reaction of an alkoxychloro silicane with These resins, when produced under moderate 25 a salt of the organic acid, e. g. sodium acetate. heating conditions are thermoplastic and are solu Other somewhat analogous compounds, which ble in common organic solvents, e. g. benzene, may be termed as amino or substituted amino ethyl alcohol, petroleum ether, etc. However silicanes, include such materials as di-tertiary upon long heating these resins ultimately become butoxy diamino silicane and di-tertiary-butoxy infusible and also insoluble. The resins are in dianilino silicane, both of which are shown in the soluble in and unaffected by water whether in the accompanying drawing. The former may be thermoplastic or the infusible state. made by adding anhydrous ammonia, to di The tertiary-alkoxy chloro silicanes may also tertiary-butoxy dichloro Silicane employing an be employed as intermediates in producing vari organic solvent such as benzene as a diluent. ous orthosilicates by reaction with alcohols, gly The ammonia removes and replaces the chlorine cols and the like. Illustrations of orthosilicates atoms in the di-tertiary-butoxy dichloro silicane and their production are indicated in the outline molecule. appearing in the appended drawing; they include The procedure for making and the type of re di-tertiary-butyll diallyll silicate; di-tert-butyll (2- action involved in making di-tertiary-butoxy ethyl-2-nitro-1,3 propanediol) silicate; di-tert 40 dianilino silicane is analogous to that for the butyl (diethylene glycol) silicate and di-tert-butyl product just discussed, except that aniline is (2-methyl-2,4-pentanediol) silicate. In making employed as the reactant with di-tertiary orthosilicates, such as those just illustrated, and butoxy dichloro silicane. It Will be understood others of this general type, the appropriate alco that by using the same tertiary-alkoxy chloro hol or glycol, as the case may be, is added to a 45 silicane and other amines or ammonia, deriva mixture of the alkoxy chloro silicane in the pres tives, various other derivative products are made ence of excess pyridine, the reactant mixture be in accordance with our invention. It will also ing diluted with a SUitable Solvent Such as benzene be understood that by using specifically different to provide a reaction mixture which can be readi tertiary-alkoxy chloro silicanes and by using the ly agitated. 50 same or different amines, ammonia, or ammonia, These compounds show an unexpected stability derivatives, further derivative products may be toward the action of water, whereas ethyl ortho produced and are likewise comprehended. silicate is very susceptible to hydrolysis even by Another illustration of the use of tertiary the moisture vapor of the atmosphere. When alkoxy chloro silicanes in the production of use ethyl Orthosilicate is placed in direct contact ful derivative products and procedure for pro with water it begins to gel almost immediately ducing the same is illustrated by the following: and after a short time it is completely hydrolyzed . . Process for the manufacture of silicon to silica. However, in the novel organic-silicon alkyd-type i resins compounds herein described which contain a group derived from a tertiary alcohol, the result 60 To a solution of 9 parts of pyridine in 20 parts ing compound is remarkably stable toward such of linseed monoglyceride was added 15 parts of hydrolysis. For example, a sample of triethyl di-tert-amoxy dichloro silicane Over a period of tert-amylsilicate was not noticeably affected after 20 minutes. The temperature rose to 54° C. dur direct contact with water for a period of over four ing the reaction. 50 parts of benzene was added months. It also remained unchanged after 6 65 and the mixture refluxed 2 hours after which it hours heating and rapid stirring at 90° C. with was cooled, filtered and Washed three times with 15% aqueous ammonia. As an additional example 50 parts of water. The benzene was then dis of the stability of such compounds toward alkaline tilled off and the viscous product heated to hydrolysis, we have found that di-n-propyl di 150° C. for 1 hour in an atmosphere of nitrogen. tert-amyl silicate after three hours refluxing with 70 The yield of product was 22 parts. - - - - - 20% aqueous is less than 15% Flowouts of this product about 0.0015 inch hydrolyzed. thick on glass were baked at 150° C. for 1 hour. The products hereinabove described may be The resulting film was light yellow, hard, trans fluid or viscous liquids, crystalline solids, or resins parent and showed good adherence to the glass. which may be soft and sticky or hard and brittle. 75 It was about 0.001 inch thick. It showed no in 3,566,956 15 16 dication of exuding, but water caused it to blush. Hereinabove. we have described and illustrated. However, upon drying it regained its transpar alkoxy chlorosilicanes having important novel ency. and useful characteristics. Warious other comr A similar, but somewhat softer film was pre pounds of the same general type, even if not pared by using an equal amount of di-tert specifically mentioned herein, are likewise con butoxy dichloro silicane in place of the tertiary prehended by this disclosure. In describing de amyl compound in the above reaction. It was rivative products and articles which can be made also found that the hardness of the resulting filna from the novel alkoxy chloro Silicanes herein re could be appreciably increased by Substituting ferred to, it will be evident that We have also tert-butoxy trichlorosilicane for one-third of the 0. been obliged to resort to Specific illustrations di-tert-butoxy dichloro silicane. which, of necessity, must be restricted in num-: It is evident that many changes can be made ber. However it will also be clear in this respect. on the process as given in the above example that various other derivative products and ar such as quantities of reactants, time and temper ticles will readily occur to those skilled in the art ature of reaction etc., without departing from 5 in the light of the illustrations and the disclos the Spirit of the invention. sure given herein. In short it will be understood The above products resemble the familiar lin that the various illustrations given herein are seed modified polyhydric alcohol-polybasic acid exemplary only of the broader and more compre alkyds and can be substituted in many instances hensive phases of this invention and are not to where the latter are used. 20 be regarded as limitative. All embodiments . Another illustrative use of the tertiary-alkoxy within the scope of this disclosure and/or of the chloro silicanes is exemplified by its use in treat appended claim, which distinguish Over the prior ing cotton fabrics to give them new and in art, are contemplated. . . . proved characteristics, including particularly What we claim is: water repellency. There follows a description of 25 Di-tertiary amoXy dichloro Silicane. Such procedure: Treatment of cloth, with tertiary-alkoacy chloro GEORGE WESLEY PEDLOW, JR. silicanes CARL SHIELLEY MINER, JR. Cotton muslin cloth was immersed in a solu 30 REFERENCES CTED tion of 100 parts of di-tertiary-amoxy dichloro silicane in 800 parts of pyridine for a period of The following references are of record in the 20 minutes to 1 hour at a temperature prefer file of this patent: ably of the order of 80-100° C., with Suitable agi UNITED STATES PATENTS tation. The cloth was then washed thoroughly 35 Number Name Date to remove the pyridine and unreacted di 1,918,338 Kaufmann ------July 18, 1933 tertiary-amoxy dichloro silicane. The di-ter 1932,255 Sherrand et al. --- Oct. 24, 1933. tiary-amoxy dichloro silicane apparently formed 2,053,474 Graves ------Sept. 8, 1936 a chemieal product With the cellulose Which con . ,2 ,09 348 . . . Shipp ??-????????? - .Oet ,26 1937 stitutes the essential material of the cloth, by rer 40 2,150,507 Kropa ------Mar. 14, 1939 acting with the hydroxyl groups of the cellulose 2,197,462 Bent ------Apr. 16, 1940 molecule, and apparently producing compounds 2,405,988 Barry ------Aug. 20, 1946 which may be regarded as orthosilicates or anal 2,438,736 . Barry ------Mar. 30, 1948 ogous thereto. In addition to the above preferred procedure, FOREIGN PATENTS Similar cloth was treated for different lengths of Number Country Date time at 80° C. and the comparative results of 160,684 Switzerland ------June 1, 1933 these different time conditions of treatment are shown in the table hereinafter. Included also OTHER REFERENCES is the per cent ash of Samples of the fabric. 50 Uchida: “Chemical Abstracts,' vol. 27, page The water repellency of the treated fabric, in 34.64 (1933). each case was evaluated by the immersion test Kalinin: "Chemical Abstracts,” vol. 35, page described by Slowinske, Amer. Dyestuff Reporter 2470(1941)? 30, 6 (1941). This involved the immersion of a Wolnov: “Chemical Abstracts,' vol. 34, page 3' by 3' weighed, air dried sample in water at 55 5048 (1940). - 80° F. for 20 minutes. The sample was then Beilstein: “Handbuch der Org. Chem.,' vol. I, placed between blotters, run through a wringer 4th ed., pages 334-335. once and weighed. The increase in weight, rep Kalinin: “Chemical Abstracts,' vol. 32, page resenting the water absorption, is given in per 6227 (1938). cent in the following table. The values are the 60 Backer: “Rec. Trav. Chim. des Pays Bas,'' vol. average of two determination. 61, pages 500-512 (published June 1942). FABLE SHOWING COMPARATIVE RESULTS ON CILOTH Hackh: “Chemical Dictionary,º 3rd ed. (1944), TFREATMENT page 33, Blakerton Co., publishers. - Time of treatment in minutes at 80° C. Karrer: “,” 3rd Eng. ed. 65 (1947) page 23, Elsevier, publishers. Tenp------0 0 1 20 30 40- 60. 90 Chemical Abstracts, 1945, pages 5882, 5877. Merriam-Webster's International Dictionary, Per Cent Moisture absorption------70. 65 53 51 34 30 32 Unabridged, 2nd edition, (1939), page 67. . Per Cent Ash------0.81.912.352.702.933.403.50 70