JPH0499782A - Production of cyclic silicone - Google Patents

Abstract

PURPOSE:To easily produce a large amount of a cyclic silicone having a specific number of siloxane units and difficult to be produced in a mass by reacting a dihydroxyorganopolysiloxane with a dihalogenosilane derivative. CONSTITUTION:The objective compound of formula III is produced by reacting an alpha, omega-dihydroxyorganopolysiloxane of formula I (R<1> and R<2> are alkyl, alkenyl, aryl or halogenated alkyl; n is 3-11) with a dihalogenosilane derivative of formula II (X is halogen; m is 0-12). The starting raw material of formula I can be produced by reacting a cyclic silicone of formula IV with a chlorosilane of formula V in the presence of water and an inorganic solid compound and hydroxylating the resultant alpha, omega-dihydrogen organopolysiloxane of formula VI.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a cyclic silicone, and more particularly to a method for easily producing a cyclic silicone having 6 or more siloxane units in large quantities.

[Prior art and problems to be solved by the invention] In general, cyclic silicones that are easily available industrially include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane, each having 5 or less siloxane units. Are known. In particular, octamethylcyclotetrasiloxane is produced in large quantities as a key raw material for various silicone products such as silicone oil, and octamethyltetrasiloxane and decamethylcyclopentasiloxane are also used as low-viscosity volatile oils for cosmetics and other products. Demand has been high in recent years.

On the other hand, cyclic silicones with 6 or more siloxane units have higher viscosity and lower volatility than those with 5 or less siloxane units, and are therefore expected to be used as new silicone oils.

This cyclic silicone having 6 or more siloxane units is placed in a very small amount in the mixture of high-boiling components during the production of octamethylcyclotetrasiloxane, but it is not possible to separate and obtain a specific cyclic silicone as a single product in large quantities from the mixture. It was difficult.

Conventionally, as a method for producing such a cyclic silicone having 6 or more siloxane units, there has been a method in which octamethylcyclotetrasiloxane is heated in the presence of a trace amount of potassium hydroxide [G'', J.

5lusarczuk et al., Journal of A
mericanChemical 5ociety
), Volume 87, No. 11, Page 931, 1965] is known. However, since the reaction in this production method is an equilibration reaction of cyclic silicone, it is essentially difficult to obtain a large amount of cyclic silicone having a specific number of siloxane units. Also, British Patent No. 1.162.
No. 075 discloses a method in which hexamethylcyclotrisiloxane is reacted with a hydrogen halide catalyst in a herosilane solvent. However, the cyclic silicone produced is limited to a mixture of siloxane units such as 6.9.12, and there is a drawback that it is impossible to obtain a cyclic silicone with a siloxane unit number other than a multiple of 3.

Therefore, it has been desired to develop a method for producing a desired cyclic silicone having a number of siloxane units of 6 or more in large quantities.

[Means to solve the problem]

Under these circumstances, the present inventors conducted various studies to solve the above problems, and found that it is possible to easily solve the above problems by reacting an α,ω-dihydroxyorganopolysiloxane having a certain siloxane chain length with a dihalogenosilane derivative. The number of siloxane units with a constant number of siloxane units is 6
It was discovered that the above cyclic silicone can be obtained, and the present invention was completed.

The present invention is shown by the following reaction formula.

(II) (I) (In the formula, R1 and R2 represent an alkyl group, an alkenyl group, an aryl group, or a halogenated alkyl group, which may be the same or different, X' represents a halogen atom, and n represents 3 to
represents an integer of 11, m represents an integer of 0 to 12, and 1 represents 6
20) That is, the present invention is based on the general formula (II)
α is expressed as .

Funato (D) is added to ω-dihydroxyorganopolysiloxane.
This is a method for producing a cyclic silicone represented by -Funenin (I), which is characterized by reacting a dihalogenosilane derivative represented by I).

- Saito (1) indicating the raw material and target compound of the present invention;
In (IT) and (III), R1 and R2 are an alkyl group, an alkenyl group, an aryl group, or a halogenated alkyl group, which may be the same or different. Among these, the alkyl group preferably has 1 to 10 carbon atoms, and specific examples include methyl group, ethyl group, propyl group,
Isopropyl group, n-butyl group, tert-butyl group,
Examples include pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group. Further, the alkenyl group preferably has 2 to 6 carbon atoms, and specific examples thereof include vinyl group, 1-propenyl group, allyl group, 1-butenyl group, and 2-pentenyl group. Further, specific examples of the aryl group include a phenyl group, and specific examples of the halogenated alkyl group include a 3.3.3-)lifluoropropyl group.

α,ω-Dihydroxyorganopolysiloxane (II) used as a raw material in the present invention can be produced, for example, according to the following reaction formula.

The following margins (in the formula, Rl, R2 and n have the same meanings as above), i.e., cyclic silicone (Iv'), chlorosilane (
V) and water in the presence of an inorganic solid compound to obtain α
, ω-dihydride organopolysiloxane (VI
), and then hydroxylation of this gives α, ω-
Dihydroxyorganopolysiloxane (I[) is obtained. In addition, the number of siloxane units can be extended by hydroxylating α,ω-dihydrolysoxane (■) to form α,ω-dihydroxyorganopolysiloxane (■) and reacting this with chlorosilane (V). α,ω-dihydrogen-organopolysiloxane (VI) is obtained, which is further hydroxylated to produce α,ω-dihydroxyorganopolysiloxane (I).
I) is obtained.

α,ω-dihydrogenorganopolysiloxane (I
T) starting material for the production of cyclic silicone (IV
), for example, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, tetradecamethylcycloheptasiloxane,
Hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane, hexakis(3,3,3-)lifluoropropyl)cyclotrisiloxane, octakis(3,3,3-trifluoropropyl)cyclotrisiloxane, fluoropropyl) cyclotetrasiloxane, etc. still,
Among these, as the cyclic silicone in which n is 6 or more, the cyclic silicone obtained by the production method of the present invention may be repeatedly used. Examples of the chlorosilane (V) include dimethylchlorosilane, diethylchlorosilane, diphenylchlorosilane, bis(3,3,3-)lifluoropropyl)chlorosilane, methylethylchlorosilane, and methylphenylchlorosilane.

In the reaction between compound (IV) and compound (V), an inorganic solid compound is used as a catalyst, but it is preferably one that is insoluble in the reaction solution and uniformly dispersed, such as silica gel, titanium dioxide, silica/alumina, etc. Among them, silica gel is particularly preferred. Incidentally, the silica gel herein refers to an amorphous silicic acid polymer, and any type of silica gel can be used in this reaction, but it is preferable that the particle size is smaller because the reaction rate can be increased with a smaller amount used.

The amount of chlorosilane (V) used in this reaction is:
It is preferably about 2 to 10 times the molar amount, more preferably 2 to 4 times the molar amount, particularly about 3 times the molar amount, relative to the mottled silicone (IV), and
The amount of inorganic solid compound to be used is 1 to 1 per cyclic silicone.
The amount of water used is preferably 50% by weight, and the amount of water used is preferably 1 to 500 times, particularly 5 to 20 times, the cyclic silicone. A reaction solvent may or may not be used, but when a solvent is used, it is preferable to use a hydrocarbon solvent that is immiscible with water, such as pentane, hexane, heptane, benzene, toluene, or the like.

Although this reaction varies depending on the reactivity of the cyclic silicone (■), it is usually
It will be completed in ~5 hours.

Hydroxylation of the obtained α,ω-dihydrogenorganoborisiloxane (V[) has been described, for example, in the journal
Talented Organic Chemistry (Journal)
of Organic Chemistry), 31
The reaction may be carried out in the presence of palladium on carbon in a dioxane buffer at 0° C. to room temperature for 1 to 10 hours according to the description in Vol., p. 885 (1966).

Further, the reaction from α,ω-dihydrogenorganopolysiloxane (■) to α,ω-dihydroxyorganopolysiloxane is similarly carried out according to the description in the above-mentioned literature. The reaction between the obtained α,ω-dihydroxyorganopolysiloxane (■) and chlorosilane (V) is carried out by reacting 2 equivalents of chlorosilane (V) in the presence of a base. Using this method, starting from easily available hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane, the desired number of siloxane units can be obtained using α, ω-
A dihydrogenorganopolysiloxane (VI) can be obtained.

Further, as the dihalogenosilane derivative (III) which is the other raw material in the reaction of the present invention, those with X=CI are particularly preferable because they are easy to obtain and handle. Specific examples of dichlorosilane, diethyldichlorosilane, dipropyldichlorosilane, diphenyldichlorosilane, bis(3,3,3-trifluoropropyl)dichlorosilane, ethylmethyldichlorosilane, methylphenyldichlorosilane , methyl 3.3.3-)lifluoropropyldichlorosilane, and the like.

Further, in the formula (I [I), m is 1 or 2, for example, commercially available 1,3-dihydrogentetramethyldisiloxane, 1,5-dihydrogenhexamethyltrisiloxane, etc.・Chemical Society (Journal of America
an Chemical 5ociety), vol. 80,
PdCj! in carbon tetrachloride solvent as described on page 5083 (1958). , 1 at 0°C to 100°C using a catalyst.
It can be obtained by reacting for ~10 hours. Further, a compound in which m is 3 or more can be obtained by subjecting the α,ω-dihydrogenorganopolysiloxane obtained by the method described above to α,ω-dichlorination using the method described above.

In the production method of the present invention, the target cyclic silicone (I
) depending on the number of siloxane units.

A plurality of combinations of ω-dihydroxyorganopolysiloxane (II) and dialkyldihalogenosilane or α,ω-dihalogenoorganoborisiloxane (■') are conceivable, and they may be selected as appropriate based on the ease of obtaining the raw materials. For example, in the case of tetradecamethylcycloheptasiloxane, α,ω-dihydroxyorganopolysiloxane (
In II), when R1=R2=methyl and n=4, it is preferable to use dimethyldichlorosilane as the dialkyldihalogenosilane (III). In addition, in the case of hexadecamethylcyclooctasiloxane, R'=R2-methyl in α,ω-dihydroxyorganopolysiloxane (II),
n=4, α,ω-dihalogenoorganopolysiloxane (III) for R' = R2=R2, m=1, X
=CI! It is preferable to use one.

α,ω-dihydroxyorganopolysiloxane (II)
The reaction between and dihalogenosilane derivative (III) is carried out in the presence of a base such as pyridine, in a hydrocarbon solvent such as pentane, hexane, heptane, benzene, or toluene, or in a halogenated hydrocarbon solvent such as chloroform or dichloromethane. Just go.

Since this reaction is a ring-closing reaction involving two molecules, it is preferable for the reaction solution to be as dilute as possible in order to improve the yield. That is, specifically, a solution of α,ω-dihydroxyorganopolysiloxane (I[) at a low concentration and a solution of a base and a dihalogenosilane derivative (III) at a low concentration as much as possible in an organic solvent. It is preferable to drop them at the same speed over as long a time as possible. The concentration of the reaction solution is selected from 0.001 to 10 mol/1, preferably 0.05 to 1 mol/I! It is. The dropping time is selected from 1 to 100 hours, preferably 5 to 20 hours.

〔Example〕

The present invention will be described below with reference to Reference Examples and Examples, but the present invention is not limited to these Examples.

Reference Example 1 1.11-Dihydrogendodemethylhexasiloxane [-In Funato (II), R' = R'CL, n
= 4] Synthesis: A 1 flask equipped with a dropping funnel is charged with 500 g of octamethylcyclotetrasiloxane, 304.2 g of water, and 50.5 g of silica gel (Kieselgel 60.250-400 mesh manufactured by Merck & Co.).

dimethylchlorosilane 479 while stirring thoroughly,
6 g was added dropwise over 30 minutes. After 30 minutes, return the flask to room temperature and continue stirring. After 4 hours, stirring is stopped and the Kieselgel is filtered. The obtained filtrate is distilled to remove excess dimethylchlorosilane. The obtained solution was transferred to a separatory funnel, and twice with 500 mf of water, 500 mf of a saturated aqueous sodium bicarbonate solution, and then 5.00 mf! Separate the solution twice with water. After completely removing the water in the solution by azeotroping with benzene, distillation under reduced pressure yielded 341 g of 1,11-dihydrodiendomethylhexasiloxane (yield: 4
7%) obtained. 198.5g (39.7%) of the raw material octamethylcyclotetrasiloxane was recovered. The yield calculated based on the reacted octamethylcyclotetrasiloxane is 78%.

Example 1 Tetradecamethylcycloheptasiloxane (- general formula (I
) for R' = R'' = CH8, A = 7): 446.3 g of phosphoric acid M buffer solution at pH = 7.3, 2.21 g of 1,4 dioxane! and 5% palladium on carbon 22,
3 g is placed in a 51 3-hole flask equipped with a stirrer. To this, 270 g of 1,11-dinohydrodiendomethylhexasiloxane synthesized in Reference Example 1 was added dropwise over 1 hour. Stirring is continued for 1 hour after the completion of the dropwise addition. The 5% palladium on carbon is then filtered and benzene 21 is added. At this time, the solution separates into two layers, so the lower aqueous layer is separated.

Next, 0.41 g of water is added to wash the benzene layer.

Repeat this operation two more times. Obtained 1, 11-
A solution of dihydroxydodecamethylhexasiloxane in benzene was concentrated under reduced pressure to 1.51, and 31 of benzene was charged into a 10f three-neck flask equipped with a stirring device. While stirring well, add 81.3 g of dimethylchlorosilane and 9 g of pyridine.
9 g of benzene solution 1.51 and 1.11-dihydroxydodecamethyl hexasiloxane benzene solution 1.51
was added dropwise at the same speed over 12 hours. Stirring is continued for 2 hours after completion of the dropwise addition.

Next, the precipitated pyridine hydrochloride is filtered. The total volume of filtration is 2I! Concentrate under reduced pressure until 0.51% of water is added to the benzene layer twice, and add 10% NaHCO3 solution to 0.51% of the benzene layer.
Wash twice with water and finally twice with water 0.51.

Benzene was distilled off under reduced pressure and the resulting solution was distilled under reduced pressure to obtain 150% tetradecamethylcycloheptasiloxane.
．． 5 g (yield 46.3%) is obtained.

Physical properties Boiling point: 91.5°C (0.15mm) Ig) MS: 50
4 (M"-15) IR: 1056 cm-'(Si-0)"Si-N
MR; ppm (δ) (in heavy benzene, TMS standard) -22
,22'II-NMR; ppm (δ) (in heavy benzene, C,11,δ-7,
15 standard) 0.2 (s) Example 2 Hexadecamethylcyclooctasiloxane (- general formula (I
) for R' = R2 = CL, f = 8): 430 g of phosphate buffer solution of p11 = 7.3, 2.1 g of 1,4-dioxane and 5% palladium on carbon 1017
g is placed in a 51 three-hole flask equipped with a stirrer. To this, 251.7 g of 1,11-dinohydrodiendomethylhexasiloxane synthesized in Reference Example 1 was added dropwise over 1 hour. Stirring is continued for 1 hour after the completion of the dropwise addition. Next, filter 5% palladium on carbon and remove benzene 21
Add. At this time, the solution separates into two layers, so the lower aqueous layer is separated.

Next, 0.41 g of water is added to wash the benzene layer.

Repeat this operation two more times. A benzene solution of 11-dihydroxydodecamethylhexasiloxane (11-dihydroxydodecamethylhexasiloxane obtained) was concentrated under reduced pressure to 1.51, and benzene 31 was charged into a 10f three-neck flask equipped with a stirring device. While stirring well, add 122.5 g of 1,3-dichlorotetrasiloxane.
and 95.4 g of pyridine in a benzene solution of 1.51 and 1.
A solution of 1.5 liters of 11-dihydroxydodecamethylhexasiloxane in benzene was added dropwise at the same rate over 12 hours. Stirring is continued for 2 hours after completion of the dropwise addition. Subsequently, the precipitated pyridine hydrochloride is filtered. The filtrate is concentrated under reduced pressure to a total volume of 3. Benzene layer 2 times with 0.51 water, 2 times with 10% NaHCO + solution 0.51, and finally water 0.
．． Wash twice with 51. Benzene is distilled off under reduced pressure, and the resulting solution is distilled under reduced pressure to obtain 127.3 g (yield: 35.6%) of hexadecamethylcyclooctasiloxane.

Physical property value: 93.0°C (0.13mmHg) MS: 578
(M"-15) IR; 1056 am-'(Si-0)"Si-N
MR: ppm (δ) (in heavy benzene, 7MS standard) -22
,30'H-NMR; J]J][11(δ) (in heavy benzene, C6H6δ=
7.15 Standard) 0.2 (s) [Effects of the Invention] According to the production method of the present invention, cyclic silicone having a specific number of siloxane units of 6 or more, which was previously difficult to produce in large quantities, can be produced in large quantities. can be obtained easily.

that's all Procedural amendment (voluntary)

Claims (1)

[Claims] 1. The following general formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, R^1 and R^2 may be the same or different alkyl groups, alkenyl group, aryl group, or halogenated alkyl group, and n is an integer from 3 to 11), the following general formula (III) ▲ Numerical formula, chemical formula, table etc.▼(III) (In the formula, R^1 and R^2 have the same meanings as above, and
represents a halogen atom, and m represents an integer from 0 to 12) The following general formula (I) is characterized by reacting a dihalogenosilane derivative represented by ) (wherein R^1 and R^2 have the same meanings as above, l
represents an integer of 6 to 20). A method for producing a cyclic silicone.