JPH06321968A - Production of cyclotrisiloxane - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a method for producing cyclotrisiloxane easily under mild conditions with good yield and without producing a by-product which is troublesome to process. [Structure] A hydrotrisiloxane of the formula (1) in which one hydrogen atom is bonded to each silicon atom at both ends is hydrolyzed in the presence of a dehydrogenation catalyst in a non-aqueous solvent. 2) A method for producing cyclotrisiloxane. (However, R ¹ and R ² are unsubstituted or substituted monovalent hydrocarbon groups, and even if they contain nitrogen, sulfur, oxygen heteroatoms or> C = 0,> S = 0 in the carbon chain. Good)

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily and selectively producing cyclotrisiloxane having various functional groups introduced into side chains. These cyclotrisiloxanes are useful as raw materials for organopolysiloxanes having various functions, and also having good monodispersity and containing few low-molecular components.

[0002]

2. Description of the Related Art Conventionally, the most widely used cyclotrisiloxane in the silicone industry is hexamethylcyclotrisiloxane in which all organic groups bonded to silicon atoms are methyl groups. There is a method of hydrolyzing dichlorodimethylsilane as a manufacturing method thereof. In this method, most of the cyclic siloxanes produced have a larger ring than cyclotetrasiloxane. Can only be obtained in yields below 10%. Hexamethylcyclotrisiloxane can also be obtained by cracking by heating in the presence of an alkali compound such as sodium hydroxide or potassium hydroxide from a compound having a larger ring than cyclotetrasiloxane, but the reaction and outflow It is slow and not useful when considering industrialization.

Also, Japanese Patent Publication Nos. 41-10916 and 47-49200.
As disclosed in US Pat. No. 3590064 and the following general formula (3)

[Chemical 3] (However, X is a chlorine atom or an acetoxy group) There is also a method of cyclizing a trisiloxane represented by the formula (3) by reacting it with an alkali metal carbonate or the like to cyclize it. There is a problem that a large amount of salt is precipitated during the synthesis of the trisiloxane and the subsequent cyclization reaction.

Furthermore, in recent years, with the development of industry, development of silicones having high functionality has been desired. That is, in order to improve heat resistance, chemical resistance, solvent resistance, low surface tension, releasability, flexibility, strength, etc., the side chain is a group other than a methyl group, such as an alkyl group having 2 or more carbon atoms. This is the development of silicones containing phenyl groups, alkyl ether groups, fluorine-containing groups, etc. As a raw material for synthesizing such a silicone polymer, cyclotrisiloxane having a group other than a methyl group introduced into its side chain is useful.

Under these circumstances, it has been attempted to synthesize cyclotrisiloxane having a group other than a methyl group introduced into its side chain. For example, JP-A-3-77893 discloses a fluorine-containing group in the side chain. A method of synthesizing the introduced cyclotrisiloxane is disclosed. This synthetic method is represented by the general formula (4)

[Chemical 4] (Wherein R _f is a fluorine-containing group and X is a halogen group) and a dihalogenosilane compound represented by the general formula (5)

[Chemical 5] In the presence of an acid acceptor, a dihydroxydisiloxane represented by is dehydrohalogenated to obtain cyclotrisiloxane. However, also in this method, when a large amount of salt such as an amine salt is deposited and the deposited salt is removed by washing with water or the like, it is uneconomical to wastewater treatment at a high cost in consideration of water pollution.

[0006]

Under the circumstances as described above, the present invention provides a method for producing cyclotrisiloxane, in which the desired product can be easily obtained in a high yield and a troublesome by-product of the treatment does not occur. It was made in an attempt.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that one Si is provided at each end.
The present invention has been completed by finding that the hydrolysis reaction of a hydrotrisiloxane having a —H group under a specific condition is sufficient. That is, the present invention has the general formula (1)

[Chemical 6] Wherein the hydrotrisiloxane represented by the formula (3) is hydrolyzed in the presence of a dehydrogenation catalyst in a non-aqueous solvent.

[Chemical 7] A method for producing cyclotrisiloxane represented by
R ¹ and R ² are unsubstituted or substituted monovalent hydrocarbon groups and may contain nitrogen, sulfur, oxygen heteroatoms or> C = O,> S = O in the carbon chain) It is a summary.

The present invention will be described in detail below. R ¹ and R ² in the general formula (1) or the general formula (2) are unsubstituted or substituted monovalent hydrocarbon groups, and examples of such groups include a methyl group, an ethyl group and a propyl group. Alkyl group, cycloalkyl group such as cyclohexyl group, vinyl group, allyl group, alkenyl group such as isopropenyl group, phenyl group, aryl group such as tolyl group, or 3,3,3-trifluoropropyl group, 6, 6,6,5,5,4,4,
Examples thereof include 3,3-nonafluorohexyl group, chloromethyl group, and 3-chloropropyl group, and the like in which hydrogen atoms of these groups are partially substituted with halogen atoms and the like. Examples of R ¹ and R ² include highly fluorinated groups, such as C ₄ F ₉ CH ₂ CH ₂ CH _2- , C ₈ F ₁₇ CH ₂ CH _2- , C ₃ F ₇ OCF (CF ₃ ) CF ₂ OCF ₂ C
F ₂ CH ₂ CH _2- , C ₃ F ₇ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) CF ₂ O (CH ₂ ) _3- , C ₃ F ₇ OCF (CF ₃ ) CF ₂
OCF (CF ₃ ) CONH (CH ₂ ) _3- , C ₈ F ₁₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OOCCH ₂ CH _2- , C ₃ F ₇ O [CF (CF ₃ ) CF ₂ O]
₃ CF (CF ₃ ) CH ₂ CH _2- and the like are exemplified. These groups have nitrogen in the middle of the carbon chain,
Heteroatoms of sulfur and oxygen or> C = O,> S = O may be contained, and R ¹ and R ^{2 in} one molecule may be the same or different.

The production method of the present invention is characterized in that the hydrotrisiloxane represented by the general formula (1) is used as a raw material and is hydrolyzed in the presence of a dehydrogenation catalyst in a non-aqueous solvent. The starting material, hydrotrisiloxane, can be prepared by a known method (see JP-A-3-197484). The water used for the hydrolysis reaction may be tap water, but deionized water or distilled water is preferred if possible. The amount of water may be 0.7 to 10.0 times mol, preferably 1.0 to 3.0 times mol, of the hydrotrisiloxane represented by the formula (1). Hydrolysis reaction is 10 to 90
It may be carried out at ℃, but is preferably 30 to 70 ℃.

As the dehydrogenation catalyst, an element of Group VIII of the Periodic Table or a compound thereof, for example, chloroplatinic acid, alcohol-modified chloroplatinic acid (see US Pat. No. 3220972), a complex of chloroplatinic acid and an olefin ( US Patent No.
No. 3159601, No. 3159662, No. 3775452), platinum black or palladium supported on a carrier such as alumina, silica, carbon, rhodium-
Examples thereof include an olefin complex and chlorotris (triphenylphosphine) rhodium (Wilkinson's catalyst), but one having palladium supported on carbon is preferable. These catalysts may be dissolved in an alcohol-based, ketone-based, ether-based, chlorinated hydrocarbon-based, or hydrocarbon-based solvent, if necessary.

As the non-aqueous solvent, those which are well mixed with cyclotrisiloxane produced by the reaction in an arbitrary ratio are preferable, and 0.01 to 100 times by weight of the hydrotrisiloxane represented by the formula (1), It is preferable to use 0.2 to 10 times the amount. Examples of such a solvent include hydrocarbon systems such as n-hexane, cyclohexane, toluene, petroleum ether and xylene, ethers such as diethyl ether, n-butyl ether, dioxane and tetrahydrofuran, acetone, methyl ethyl ketone, dibutyl ketone, acetic acid. Examples include ketones such as ethyl, esters, methylene chloride, chlorobenzene, chlorinated hydrocarbons such as chloroform, nitriles such as acetonitrile, and fluorine such as trifluorobenzene and metaxylene hexafluoride. Therefore, they may be used alone or, if necessary, may be used in combination with two or more kinds of solvents.

In the production method of the present invention, hydrogen gas is generated as the reaction progresses, so it is desirable to carry out the reaction while replacing the inside of the reaction vessel with an inert gas such as nitrogen.

[0013]

【Example】

Example 1 In a 1 L four-necked flask equipped with a stirrer, a thermometer and a Dimroth condenser, 5% loaded Pd / carbon 0.5 g, n-hexane was added.
After charging 59.0 g, THF 5.0 g and pure water 5.4 g, the internal temperature was raised to 50 ° C. with stirring while flowing nitrogen gas at a flow rate of 50 ml / min, and then the following structural formula

[Chemical 8] 59.1 g of hydrotrisiloxane of was added dropwise over 20 minutes.

After completion of dropping, 5% Pd / carbon was filtered off,
When the filtrate was rectified, the following structural formula

[Chemical 9] Of cyclotrisiloxane was obtained with a yield of 75%. Boiling point 81 ℃ /
55 mmHg

Example 2 The following structural formula

[Chemical 10] 69.5 g of hydrotrisiloxane, 80.0 g of n-hexane,
The reaction was performed in the same manner as in Example 1 except that 8.0 g of THF and 6.3 g of pure water were used, and the yield was 81% with the following structural formula.

[Chemical 11] Of cyclotrisiloxane was obtained. Boiling point 78 ℃ / 18mmHg

Example 3 The following structural formula

[Chemical 12] 52.2 g of hydrotrisiloxane, 60.0 g of n-hexane,
The reaction was performed in the same manner as in Example 1 except that 4.0 g of THF and 6.3 g of pure water were used, and hexamethylcyclotrisiloxane was obtained with a yield of 69%. Boiling point 134 ℃ / 760mmHg, melting point 62〜
64 ° C

Example 4 The following structural formula

[Chemical 13] Was used in the same manner as in Example 1 except that 67.6 g of hydrotrisiloxane, 90.0 g of toluene, 8.0 g of methyl ethyl ketone (MEK), and 6.3 g of pure water were used, and the yield was 77%.

[Chemical 14] Of cyclotrisiloxane was obtained. Boiling point 82 ℃ / 2mmHg

Example 5 The following structural formula

[Chemical 15] 73.5 g of hydrotrisiloxane, 80.0 g of n-hexane,
The reaction was performed in the same manner as in Example 1 except that 20.0 g of n-butyl ether and 6.3 g of pure water were used, and the following structural formula was used at a yield of 70%.

[Chemical 16] Of cyclotrisiloxane was obtained. Boiling point 107 ℃ / 2mmHg

Example 6 The following structural formula

[Chemical 17] 76.0 g of hydrotrisiloxane, benzotrifluoride
The reaction was performed in the same manner as in Example 1 except that 70.0 g, MEK10.0 g, and pure water 6.3 g were used, and the yield was 75% with the following structural formula.

[Chemical 18] Of cyclotrisiloxane was obtained. Boiling point 103 ℃ / 100mmHg

Example 7 The following structural formula

[Chemical 19] Hydrotrisiloxane of 160.0g, metaxylene hexafluoride (hereinafter MXHF) 160.0g, THF 10.0g, pure water
The reaction was performed in the same manner as in Example 1 except that 8.1 g was used, and the yield was 85% with the following structural formula.

[Chemical 20] Of cyclotrisiloxane was obtained. Boiling point 112 ℃ / 3mmHg

Example 8 The following structural formula

[Chemical 21] Hydrotrisiloxane of 139.3g, MXHF140.0g, ME
The reaction was performed in the same manner as in Example 1 except that K10.0 g and pure water 8.1 g were used, and the yield was 83% with the following structural formula.

[Chemical formula 22] Of cyclotrisiloxane was obtained. Boiling point 114 ℃ / 3mmHg

Example 9 The following structural formula

[Chemical formula 23] Hydrotrisiloxane of 188.0g, MXHF250.0g, ME
The reaction was performed in the same manner as in Example 1 except that K20.0 g and pure water 8.1 g were used, and the following structural formula was used with a yield of 83%.

[Chemical formula 24] Of cyclotrisiloxane was obtained. Boiling point 120 ℃ / 4mmHg

[0023]

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a novel method for producing cyclotrisiloxane under mild conditions with ease and without producing a by-product which is troublesome to process. By the method of the present invention, cyclotrisiloxane having various groups in the side chain can be produced, and since this cyclotrisiloxane is extremely useful as a raw material for polysiloxane,
The effect of the present invention is extremely large.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takashi Matsuda No. 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma Prefecture 10 Shinetsu Chemical Industry Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Tomofumi Sudo Matsui, Usui-gun, Gunma Prefecture Tamachi Daiji Hitomi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (3)

[Claims] 1. A compound represented by the general formula (1): Wherein the hydrotrisiloxane represented by the formula (3) is hydrolyzed in the presence of a dehydrogenation catalyst in a non-aqueous solvent. The manufacturing method of cyclotrisiloxane shown by these. (However, R ¹ and R ² are unsubstituted or substituted monovalent hydrocarbon groups, and even if they contain nitrogen, sulfur, oxygen heteroatoms or> C = O,> S = O in the carbon chain. Good) 2. The method for producing cyclotrisiloxane according to claim 1, wherein the amount of water used for the hydrolysis is 0.7 to 10.0 times the mole of hydrotrisiloxane. 3. The method for producing cyclotrisiloxane according to claim 1, wherein the non-aqueous solvent used for hydrolysis can dissolve cyclotrisiloxane produced.