SU802311A1 - Method of preparing alkoxysiloxane oligomers - Google Patents

Description

54 METHOD OF OBTAINING ALCOXYLESOXANE OLIGOMERS

The invention relates to the production of organosilicon compounds containing functional groups on silicon atoms, in particular alkoxysiloxane oligomers, such an invention can be used in the synthetic rubber industry and in the rubber industry, and the resulting oligomers for the manufacture of thermal, freezing and oil-resistant organosilicon polymers, as well as organosilicon oligomers with other functional groups. A known method for producing this xylosiloxane oligomers by hydrolysis of dimethyldiethoxysilane in an aqueous-alcoholic medium. The disadvantage of this method is that during hydrolysis a complex mixture of oligomers is formed and it is not possible to obtain diethoxyoligomethyl siloxanes with a given number of silicon atoms in a molecule. A method is known for producing alkoxy siloxane oligomers of a given molecular weight by condensation reaction of a siloxane oligomer with terminal hydroxyl groups with organoxypxychysychum hCsul heated to p prn.-1 gt and a catalyst of sukvalinalny clay, silicon, ovine, drawing, drawing, drawing, silicon dioxide, silicon, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silicon dioxide, silica gel, silica gel, silicon dioxide. preparation of the initial oligomer with hydroxyl groups, the need to separate the catalyst from the reaction products by filtration, which is associated with the complication of technological equipment and the loss the desired product, and finally, a high reaction temperature. A known method for producing alkoxysiloxane oligomers of a given molecular weight by reacting chlorine-containing oligomers with alcohol HD. The disadvantage of the method is the need to obtain a chlorosiloxane oligomer, which is a difficult task, in addition, the method is also complicated by filtering the reaction products from pyridine hydrochloride. A large amount of solvent is used in the synthesis (the ratio of chlorosiloxane to benzene is 1: 2). A known method for producing an alkoxysiloxane oligomer by reacting octamethylcyclotetrasiloxdia or a siloxane polymer with spirits when heated in the presence of a catalyst of sulfuric acid with i in the cadre: - with a danzeous azeotropic distillation: 4) 4. The disadvantage of this method is that water that needs to be distilled off as an azeotrope with toluene or benzene. The synthesis uses a large amount of solvent / (approximately equal to the amount of cyclosiloxane). In addition, it is necessary to neutralize the sulfuric acid and filter the reaction products. The duration of the synthesis is long: from 24 to 54 hours. Low-molecular oligomers with two and three, silicon atoms in molecules, are obtained. A method of producing alkoxy siloxane oligomers is known by splitting hexamethyl cyclotrisiloxane with alcohol in the presence of a catalyst: HC1, HCl 3, or silica-alumina in a solvent 5. The disadvantage of this method is the use of a solvent for azeotropic distillation of water. You get low molecular weight oligomers with three silicon atoms in the chain. In addition, only highly reactive cyclotrisiloxanes are used in this process. The aluminosilicate and perchloric acid {after neutralization with chalk) are removed from the reaction products by filtration. Crashes with the use of octamethylcyclotetrasiloxane and dimethyl diethoxysilane in glass ampoules with the presence of catalytic amounts of sulfuric acid b The disadvantages of this method are in need; obtaining both low molecular weight and high molecular weight dialkoxysiloxane oligomero in a given molecular weight by splitting cyclosiloxanes with dimethyldiethoxysilane in the presence of potassium silicate, caustic soda or potassium at a temperature of 50–200 ° C, preferably 7. Catalyst as a catalyst. Not necessary: Remove catalyst from the reaction products by filtration or centrifugation, which leads to the condition of the technological process and the loss of the target product, as well as a high temperature reaction. The purpose of the invention is to simplify the process of producing alkoxysiloxane oligomero ;. This goal is achieved by using as a catalyst the reaction of the cleavage of cyclosiloxanes by alkoxysilanes — redn. phosphorus (P4) and iodine (1) with a ratio of P: I equal to 1: 2-1: 5. The essence of the method lies in the fact that cyclosiloxanes of the general formula () n, where R and R are an alkyl, halogen or aryl radical, for example methyl, 3,3,3-trifluoropropyl, phenyl, т 3 or 4, is reacted with alkoxy silyl compounds of the general formula () Si where R is an alkyl radical, for example ethyl or propyl, Rl, R, R is an alkoxy group or an organic radical, for example methyl in the presence of a catalyst-mixture of red phosphorus with iodine with a ratio of R: l equal to 1: 2 - 1: 5, in the amount of 0 , 5-1 wt.% From the mixture of initial reagents. The reaction temperature is from 20 to 120 ° C, preferably 50-100s. The duration of the reaction is from 0.2 to 15 hours, preferably from 0.5 to 5 hours, and is determined by the change in the refractive index of the reaction mixture. At the time of completion of the reaction, the refractive index of the reaction mixture becomes constant. - The number of siloxane units (p) in alkoxy oligomers is determined by the ratio of cyclosiloxane and alkoxysilane: with an increase in this ratio, the molecular weight of the alkoxysiloxane oligomer increases. The preferred ratio is from 2: 1 to 70: 1. The reaction catalyst is removed from the reaction mixture during the distillation of volatile products from alkoxy oligomers. As a result of the reaction, Gshkoxysiloxane oligomers are obtained from the molecule. 800-35000 with a specific mass. Example 1. To 20g of octamethylcyclotetrasiloxane, 4 g of dimethyldiethoxysilane (molar ratio 2.5: 1) and 0.2404 g {1 may.% Of the mixture of initial reagents) of the catalyst — a mixture of P 0.011 2 g and 2 0.2292 g (ratio R: L. in r-atoms 1: 5). The reaction mixture is stirred at 15.5 hours in an instrument protected from moisture in the air. After removal of low-boiling products in a dry nitrogen atmosphere at a residual pressure of 4 mm Hg. and temperature in the male: a 19.69 g (95%) alkoxy oligomer with a molecular weight of 1260, calculated from the alkoxy group content of 7.14 wt.%, is determined by reaction GLC analysis). According to the analysis, the resulting oligomer has the formula C HjOElCHj) Siol.Si (CH3) 20C2H5 Example 2. Of the 20 g of hexamethylcyclotrisiloxane, 4 g of dimethyl-. diethoxysilane (molar ratio 3.3: 1) and OL200 g (0.5 wt.%) catalyst - mixture P 0.0130 g

HtJj 0.1070 g (P: 3 ratio in g-atoms 1: 2) by heating for 20 minutes at 100 ° C and distilling off volatile products, under the conditions of Example 1, 20.16 g (91.3%) are obtained alkoxy oligomer with a molecular weight of 1285 (calculated on the content of diethoxy groups — 7.0 wt.%, which is determined by reaction GLC analysis, which corresponds to the formula ".O., H50L (CH,), (CH3) 30C, H

Example 3. Of 15 g of hexamethyl cyclotrisiloxane, 0.15 g of dimethyldiethoxysilane (66.6: 1 molar ratio) and 0.0757 g (0.5 wt.%) Of the catalyst, a mixture of P 0.0045 g and Ij 0, 0722 g (P: U ratio in g-atoms 1: 5) when heated with stirring for 10 min while the product is deactivated at a temperature of 150 ° C in a bath and 3 mm Hg. 8.91 g (91.5%) of alkoxy oligomer with a molecular weight of 28,000 are obtained (calculated on the content of diethoxy groups — 0.32% by weight, which is determined by GLC analysis). This corresponds to the formula

n "l l26 0 ° Tb 20S f

Example 4. To 15 g of 1,3,5-trimethyl-1, 3,5-tris (s, 3,3-trifluoropropyl) cyclotrisiloxane and 0.08 g of dimethyldiethoxysilane (66.6: 1 molar ratio) are added 0 , 0753 g (o, 5 wt.%) Of catalyst-mixture P 0.0035 g and tij 0.0718 g (P ratio: in g-atoms 1: 5) and the reaction mixture is heated at 3 hours. After distillation, the volatile 14.78 g (98%) of alkoxy oligomers with a molecular weight of 31,200 (calculated by the content of ethoxy groups of 0.29% by weight, determined by titration), which corresponds to the formula

Р2 "50 СНз1СГзСН2СН2) (СНз) ,, OS, AND

 1.3820.

Example 5. To 20 g of octamethylcyclotetrasiloxane were added 1.12 g of tetraethoxysilane (molar ratio 12.5: 1) and 0.2100 g (l wt.%) Of the catalyst mixture P4 0.0098 g and Oj 0.2002 g ( the ratio of P: jf in g-atoms is 1: 5). The reaction mixture was stirred at 100 ° C for 4 hours and after deacouling, under the conditions of Example 1, 16.82 g (92.2%) of an alkoxy oligomer with a molecular weight of 3888 were obtained (according to the content of ethoxy groups, determined by reaction GLC analysis 4, 6 wt.%). This corresponds to the formulas

.

p 1.4050.

Example 6. Of 20 g of 1,1,3,3,5-pentamethyl-5-phenylcyclotrisiloxane, 0.39 g of dimethyldiethoxysilane (molar ratio 26.6: 1 / and 0.1029 g (0.5 wt.% catalyst mixture of P4 0.0044 g and Jj of 0.0985 g (P ratio: in g-atoms 1: 5) after heating for 3.5 hours while the product is lost, indicated in Example 3, 20 g (98.5% a) alkoxy oligomer with a molecular weight of 7668 (based on the content of the methoxy groups, which is determined by the reaction GLC analysis of 1.17 wt.%, which corresponds to the formula

; S.,) 25; about 5 sne1SbN5)

26,6

.f | s; (CHjUOC, iH5

p 1.4690. Example 7. 11.1 g of octamethylcyclotetrasiloxane, 0.68 g of trimethylpropoxysilane (molar ratio 7.5: 1) and 0.1163 g (1 wt.%) Of the catalyst - a mixture of P 0.0055 g and I2 0.1109 g { The ° P: I ratio in g-atoms 1: 5) is heated for 10 hours at 100 ° C and set free under the conditions of Example 1. 9.3 g (yield 80%) of an alkoxy oligomer with a molecular weight of 2350 are obtained (calculated from the content of propoxy - 2.53% by weight, which is determined by reaction GLC analysis). This corresponds to the formula

 C (CH) (CH3) C Thus, alkoxysiloxane oligomers with different desired molecular weights can be obtained from cyclosiloxanes and alkoxysilanes using a mixture of red phosphorus with iodine as a catalyst. Such a catalyst is easily removed when the reaction mass is removed from the reaction mixture after completion of the reaction, which allows to obtain alkoxysiloxaces free from impurities, and greatly simplifies the process.

Claims (3)

Invention Formula The method of producing alkoxysiloxane oligomers by the interaction of organocyclosiloxanes with alkoxysilanes in the presence of a catalyst, characterized in that, in order to simplify the process, a mixture of red phosphorus and iodine with a P: 3 ratio of 1: 2 - 1: 5 is used in the amount of 0 , 51 wt.% From the initial reagents. Sources of information taken into account in the examination .1. Kuznetsova V.N. and others. Synthesis of linear ot, (0- (diztoksi) - ioC, 60- (dihydroxybutoxy) oligomethylsiloxanes. Synthesis and physico-chemical polymers Kiev, Naukova Dumka, Issue 15, 1975, p. 139. 2. The patent of France 1495011, cl. From 08 published. 1967. 7 802.И18 3. Lnlrianov KA and others. Snptez-triFeshiprnsiloksg.sho.-Journal ofiiatMi 01, () - digilroxy- and k:, (0-diethoxy1 oli-.imii, 1970, vol. 40, v. J, d. 706. organosiloxanes. -Arnsky chemical-6. USSR copyright map Journal of Cues, 1968, 21, p. 317.№ 260176, cl. C 08 O 77/18, 1969. but. U.S. Patent 2,831,199 cl. 260-448, published. 19G59., 7. US patent 5. Kuznetsova A. G. et al. Synthesis of cells. 260-448.8, publ. (proto1,5-dialkoxy-1,3,5-trimethyl-1,3,5-type).