PROCESS FOR THE PRODUCTION OF DIARALKYLDICHLOROSILANES AND THEIR USE IN MANUFACTURE OF POLYSILOXANE

Abstract: Novel diaralkyldichlorosilanes of the general formula (I) (wherein R¹ and R² each represent hydrogen or C₁ to C₄ alkyl, R³ and R⁴ each represent C₁ to C₄ alkyl, p and q are 0 to 3; provided that R¹ and R² are not hydrogen when p and q are 0) can be made from dichlorosilane and the corresponding styrene compounds and are useful as monomers for produc­ ing polysiloxanes and as intermediates for synthesizing organosilicon compounds.

Description: "NOVEL DIARALKYLDICHLOROSILANES, PROCESS FOR THEIR PRODUCTION AND THEIR USE IN MANUFACTURE OF POLYSILOXANES" The present invention relates to novel organosilicon compounds, and in particular to diaralkyldichlorosilanes. Of the organosilicon compounds, diorganodichiorosilanes are very important corn pounds for use as bifuhctional monomers in manufacturing polysiloxanes. Dialkyldichloros ilanes and diphenyldichlorosilanes have heretofore been generally known, but diaralkyldichlorosilanes have never been reported. Dichlorosilanes having an aralkyl group are found in US Patent No. 2. 618. 646 and elsewhere, but are limited to those having one aralkyl group. In recent years, along with the development of the silicone resin industry, a need for novel organosilicon compounds with modified properties has arisen. The present inventors have prepared dichlorosilanes having two aralkyl groups for the first time. The compounds of the present invention are diaralkyldichlorosilanes expressed by the general formula EMI2.1 R1 and Rê are the same or different and each represent hydrogen or C1 to C4 alkyl, p and q are the same or different and each represents 0, 1, 2 or 3, when p or q is 1 then R or R4 is C1 to C4 alkyl and when p or q is 2 or 3 then each R3 or R is the same or different and is C1 to C4 alkyl. The compound wherein R1 and R2 are hydrogen and p and q are 0 is excluded, and the present compounds are thus alkyl substituted diphenethyldichloros ilanes. Of the coin pounds expressed by the general formula (I), the preferred ones are those wherein p and q are both 0, ie di-ss-phenylalkyldichlorosilanes (wherein the alkyls may be the same or different but not both ethyl);those wherein p and q are both 1, ie di-P -tolyalkyldichlorosilanes, and those wherein one of p and q is 0 and the other is 1, ie -phenylalkyl. /3 -'tolylalkyldichlorosilanes. Concrete examples of the compounds of the present invention include: di-ss-phenylpropyldichlorosilane di-ss -phenylbutyldichlorosilane di-ss-phenylpentyldichlorosilane di-/3 -phenylhexyldichlorosilane di-ss -tolylethyldichlorosilane di-ss -tolylpropyldichlorosilane di-ss -tolylbutyldichlorosilane di-/3 t ol ylhe xyld ichlor os ilane ss-tolylethy.ss-tolylpropyldichlorosilane p -tolylethyl.ss-tolylbutyldichlorosilane ss-tolylpropyl.ss-tolylbutyldichlorosilane ss-phenylethyl.ss-tolylethyldichlorosilane, and p-phenylethyl.ss-tolylpropyldichlorosilane. The corn pounds of the present invention are not restricted to those wherein p and q are selected from 0 and 1. For example the possible aralkyl substituents of compounds of the invention further include xylyl, eg 2, 3-xylyl, where there are two methyl groups on the phenyl ring, and mesityl where there are three methyl groups on the phenyl ring. 3 4 Moreover, R and R need not be confined to methyl groups. For instance, the possible aralkyl substituents further include cumyl. The present invention provides a process for producing the compounds of the general formula (I). The process is carried out as shown in the following equations (A) and (B): Equation (A) EMI4.1 Equation (B) EMI4.2 (wherein RÚ, Rê, q ,R and R4 are as defined above). Firstly, dichlorosilane (II) is subjected to an addition reaction with a styrene compound (III) which is styrene itself or a styrene derivative, at a temperature of 30 to 200 C in the presence of a catalyst which is a complex of a transition metal of group VIII of the Periodic Table and a phosphine compound, to form a monoaralkyldichlorosilane (IV), as shown in the above equation (A). Next, this monoaralkyldichlorosilane (IV) is subjected to an addition reaction with a styrene compound (V) which is styrene itself or a styrene derivative, at a temperature of 10 to 200 C in the presence of a catalyst which is a complex of a transition metal of group VIII of the Periodic Table and a phosphine compound or in the presence of chloroplatinic acid (except that where R2 is hydrogen, chloroplatinic acid is not employed) to form a diaralkyldichlorosilane (I), as shown in the equation (B) Concrete examples of the styrene derivatives include a-methylstyrene, -m ethylstyrene, a a-ethylstyrene, a a-propylstyrene, a -butylstyrene, methylstyrenes (vinyltoluenes), a -methyl- methylstyrenes, a - ethyl-methylstyrenes, a - propyl-methylstyrenes, a -butylmethylstyrenes, etc. For methylstyrene and the methylstyrene derivatives, the ortho- meta- or para-compounds or mixtures thereof can be used. The complex of a transition metal of group VIII of the Periodic Table and a phosphine compound is preferably a complex represented by the general formula of MXn (PR 3)m wherein RO is phenyl (hereinafter abbreviated to Ph), aryl, alkyl or aralkyl; M is a metal selected from ruthenium, rhodium, nickel and platinum; X is a covalently bound halogen or hydrogen atom, a covalently bound substituted silyl group, or a non-covalently bound carbon monoxide molecule or aromatic hydrocarbon compound; n is an integer of 0 to 4 and m is an integer of 2 to 4, provided that The transition metal phosphine compound complex can be, for instance, RhH (P Ph3)4, RhH (CO) (PPh3)3ZRhCt(CO)(PPh3)3, RhC(PPh)3)3, RuC2(PPh3)3, RUHCl (PPh3)3[C6H6], RuHCl(PPh3)3 33 [C6H5CH3], RuH3(PPh3)3[PPh3)3[Si(OCH3)3], RuH3(PPh3)3[Si(OCH3)2Ph], RuH(PPh3)3[Si(C2H5)2Cl],RuH2(PPh3)4, NiCl2(PPh3)2 or Pt(PPh3)4. Particularly when the styrene derivatives has no substituent at the a-position, the use of Pt(PPh3)4 is preferable. The diaralkyldichlorosilanes of the present invention are novel compounds and useful as monomers for polysiloxanes for use in improving the properties of silicone oils and varnishes employed for electrical insulating materials, lubricating oils, water repellants, paints and lacquers, release agents, etc. Further it is possible to utilize them as intermediates for synthesizing novel organosilicon compounds. Diaralkyldichlorosilanes of the present invention, when heated with water, form silanols and/or cyclic siloxanes, which, in turn, when heated in the presence of an acid or a base as a catalyst, are polycondensed to form polymers. Further, it is also possible to hydrolyze at least one diaralkyldichlorosilane of the present invention together with at least one other organodichlorosilanc and then copolycondense the resulting silanols and/or cyclic siloxanes. The present invention is illustrated by the following non-limiting examples. Reference is made in the examples to the accompanying drawings, in which: Figure 1 shows the infrared ray absorption spectra (abbreviated to IR) of the product of Example 1, di-ss-phenyl- propyldichlorosilane; Figure 2 shows the nuclear magnetic resonance spectra (NMR) of the product of example 1; Figure 3 shows the IR of the intermediate in Example 2, mono-B- tolylethyldichlorosilane; Figure 4 shows the NMR of the intermediate in Example 2; Figure 5 shows the IR of the product of Example 2, di-B- tolylethyldichlorosilane; and Figure 6 shows the NMR of the product of Example 2. Example 1 &alpha;-Methylstyrene (154 g 1. 3 mol) and chlorotris(triphenylphosphine)rhodium [RhCl(PPh3)5] (0. 9 g 1.0 x 10-3 mol) were introduced into a 500 ml stainless steel pressure reactor, which was then closed. The reactor was cooled in a dry ice-methanol bath, and dichlorosilane (101 g 1. 0 mol) was introduced through an introduction tube and the reactor sealed. Reaction was carried out with stirring at 70 C for 7 hours. The resulting reaction liquid was distilled in vacuo to obtain 192 g of a product having a boiling point of 103 C/9. 5 mmHg. The IR spectra of the product showed -1 an absorption specific to Si-H at 2, 205 cm , and the NMR spectra proton signals of Si-H, -CH2-Si, -CH- and CH C H at 5 28, 1. 54, 3. 13, 1. 35 and 7 19 6 (ppm) respectively. Thus it was confirmed that the product was mono--phenylpropyldichlorosilane [CH3CH(C 21. The ss-phenylpropyldichlorosilane (66 g 0. 3 mol), -chloroplatinic acid (0 031 g, 6 x 10-5 mol) and a-methyl- styrene (71 g, 0. 6 mol) were fed into a flask to carry out reaction at 20 - 30 0C- for 5 hours. The reaction liquid was distilled in vacuo to obtain 85 g of a product having a boiling point of 0 20 160 - 161 C/2. 5 mmHg. This product had an nD of 1. 5446; its IR is shown in Figure 1 and its NMR in Figure 2. Thus it was confirmed that this product was di-ss-phenylpropyldichlorosilane [(C6H5.CH. CH3CH2)2SiC SICL 2 Example 2 Vinyltoluene [molar ratio of meta-form (m): para-form (p) = 65:35] (154 g 1. 3 mol) and chlorotris (triphenylphosphine ) rhodium [RhCt(PPh3)1 (0, 9 g 1. 0 x 10 mol) were introduced into a 500 mXstainless steel pressure reactor, which was then closed. The reactor was cooled in a dry ice-methanol bath, and dichlorosilane (101 g (1. 0 mol) was introduced therein through an introduction tube, and the reactor then sealed. Reaction was carried out at 70 C for 8 hours. The resulting reaction liquid was distilled in vacuo to obtain 196. 7 g of a product having a boiling point of 110 C/10 mmHg. This product had the IR shown in Figure 3 and the NMR shown in Figure 4 Thus it was confirmed that the product was mono- - tolylethyldichlorosilane (a mixture of m -form with p-form). The ss-tolylethyldichlorosilane (109. 5 g, 0. 5 mol), tetrakis (triphenylphosphine)platinum (O)[Pt(PPh3)4] (0. 62 g 5 x 10 4 mol) and vinyltoluene [m p (molar ratio) = 65:35] (118 g, 1. 0 mol) were fed into a 500 flask, and reaction was carried out under nitrogen atmosphere at 100 C for 8 hours. The resulting reaction liquid was distilled to obtain 153. 7 g of a product having a boiling point of 186 - 187 C/3 mmHg. This product had an 20 of nD 1. 5463 and exhibited the IR shown in Figure 5 and the NMR shown in figure 6. Thus it was confirmed that this product was di-B- tolylethyldichlorosilane [(CH3C6H4CH2CH2)2SiCl2]. Example 3 Dichlorosilane (31. 7 g, 314 millimols), styrene (56. 3 g, 541 millimols) and chlorotris (triphenylphosphine)rhodium (0. 2182 g, 2. 36 x 10-4 mol) were introduced into a 200 stainless steel reactor, which was then closed. Reaction was carried out with stirring on heating in an oil bath at 15OOC for 20 hours. The resulting reaction liquid was distilled in vacuo to obtain 45. 7 g of mono-ss-phenylethyldichlorosilane. The mono-ss-phenylethyldichlorosilane (41 g, 0. 2 mol), chloroplatinic acid (0, 02 g, 4 x 10 5 mol) and a -methyistyrene (47. 3 g, 0. 4 mol) were fed into a flask to carry out reaction at 20 - 30 0C for 5 hours to obtain ss-phenylethyl.ss-phenylpropyl- dichlorosilane. Example 4 Mono-ss-phenylpropyldichlorosilane as obtained in Example 1 (66 g, 0. 3 mol), styrene (104 g, 1. 0 mol) and tetrakis(tri -5 phenylphosphine)platinum(O) (0. 08 g, 6. 42 x 10 mol) were introduced into a 300 mt stainless steel reactor, and reaction was carried out with stirring by heating in an oil bath at 100 C for 15 hours to obtain /3 -phenyl. /3 -phenylpropyldichloros ilane. Comparative Example 1 Dichlorosilane (30. 9 g, 0 3 mol), styrene (56. 5 g, 0. 543 mol) and an isopropanol solution (50 mQ) of chloroplatinic acid jH2PtC6. 6H2O](4.83 x 10-6 mol) were introduced into a 200 ml stainless steel reactor. Reaction was carried out with stirring on heating in an oil bath at 500C for 15 hours. The resulting reaction liquid resinified. Example 5 Di-/3 -phenylpropyldichlorosilane (145 g) as obtained in Example 1 was dropwise added with stirring to 200 g of a waterdiisopropyl ether mixture (water 165 g and diisopropyl ether 40 g) maintained at 60 C, over one hour, and after the addition, reaction was carried out with stirring for 4 hours. The aqueous phase portion of the resulting reaction liquid was removed, and the ether solution of the resulting product was washed five times with 50 ml of water. After the washed water became alkaline, 50 ml of toluene was added to the ether solution, and toluene, ether and water were removed by vaporization at 100 C in vacuo to obtain 105 g of a product. To this product (96 g) were added 3. 0 g of hexamethyldisiloxane, and further, with stirring, 1 ml of a 10% aqueous solution of tetramethylammonium hydroxide [(CH3)4NO0H] and 10 ml of toluene, and the mixture was heated up to 80 C. The water of the 10% aqueous solution was distilled off by blowing nitrogen gas into the reaction liquid, followed by reaction with stirring at 80 C for 10 hours. After the reaction, 75 ml of toluene was added to obtain a toluene solution, which was then washed three times with 80 ml of water. After the solution became neutral, toluene was distilled off at 100 C to obtain 93. 0 g of a polysiloxane.

Claims: CLAIMS: 1. A diaralkyldichlorosilane of the general formula (I) EMI12.1 wherein RÚ and Rê are the same or different and each represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, p and q are the same or different and each represents 0, 1, 2 or 3, 3 4 when p and/or q is 1 then R and/or R, as the case may be, is an alkyl group having from 1 to 4 carbon atoms and when p and/or q is 2 or 3 then each R3 and/or R4, as the case may be, is the same or different and is an alkyl group having from 1 to 4 carbon atoms f provided that R1 and R2 are not both hydrogen atoms when p and q are both 0. 2 A compound according to claim 1 which is a phenylalkyldichlorosilane wherein the alkyl groups are the same or different but not both ethyl. 3 A compound according to claim 2 which is di-/3- phenylpropyldichloros ilane. 4. A compound according to claim 1 which is a tolylalkyldichloros ilane. 5 A compound according to claim 4 which is di-ss- tolylethyldichlorosilane. 6. A compound according to claim 1 which is a ss-phenylalkyl. ss -tolylalkyldichlorosilane. 7 A process for producing a diaralkyldichlorosilane expressed by the general formula (I) EMI13.1 (wherein RÚ and Rê are the same or different and each represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, p and q are the same or different and each represents 0, 1, 2 or 3, when p and/or q is 1 then R and/or R4, as the case may be, is an alkyl group having from 1 to 4 carbon atoms and when p and/or q is 2 or 3 then each R and/or R4, as the case may be, is the same or different and is an alkyl group having from 1 to 4 carbon atoms; provided that R1 and R2 are not both hydrogen atoms when p and q are both 0) which process comprises: subjecting dichlorosilane (II) to an addition reaction with a styrene compound (III) which is styrene itself, or a styrene derivative EMI14.1 (wherein R1, p and R3 each have the same definition as above), at a temperature of 30 to 200 C in the presence of a catalyst which is a complex of a transition metal of group VIII of the Periodic Table and a phosphine compound, to form a monoaralkyldichlorosilane expressed by the general formula (IV) EMI15.1 and then subjecting the monoaralkyldichlorosilane to an addition reaction with a styrene compound (V) which is styrene itself or a styrene derivative EMI15.2 (wherein R, q and R4 each have the same definition as above), at a temperature of 10 to 2000C in the presence of a catalyst which is a complex of a transition metal of group VIII of the Periodic Table and a phosphine compound, or is chloroplatinic acid (unless R2 in the general formula (V) is hydrogen atom). 8. A process according to claim 7 wherein the catalyst is a complex expressed by the general formula MX (PR0) n 3m wherein Ro is phenyl, aryl, alkyl or aralkyl; M is a metal selected from ruthenium, rhodium, nickel, and platinum; X is a covalently bound halogen or hydrogen atom, a covalentlybound substituted silyl group, or a non-covalently bound carbon monoxide molecule or aromatic hydrocarbon compound;n is an integer of 0 to 4 and m is an integer of 2 to 4, provided that 3 s (n+m) s 7. 9. A process for producing polysiloxanes which comprises hydrolyzing at least one diaralkyldichlorosilane according to any of claims 1 to 6, optionally together with at least one other organodichiorosilane, followed by polycondensation. 10. A polysiloxane obtained by a process according to claim 9.

Inventors: KOGA, ISAO, OHTAKE, NOBUMASA, TERUI, YOHJI
Applicants: CHISSO CORPORATION
Application year: 1979
Main classification: C07F7
IPC codes: C07F7, C08G77