JP2001151889A - Method for producing branched silicone oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and stably producing branched silicone oil having stable physical properties because the silicone oil does not contain reactive groups such as an alkoxy group, especially the branched silicone oil having hydrogen-silicon bond. SOLUTION: This method for producing the branched silicone oil is to formulate 100 pts.wt. of a first organopolysiloxane represented by chemical formula 1 with 0.1-100 pts.wt. of a second organopolysiloxane represented by chemical formula 2, and then to perform condensation and equilibration of the organopolysiloxane mixture in the presence of an acidic catalyst, wherein R1 and R5 are each a 1-20C monovalent hydrocarbon group; m is 3 to 7; i is 1 to 100; and j is 0 to 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a branched silicone oil, and more particularly to a method for easily producing a physically stable branched silicone oil.

[0002]

2. Description of the Related Art Branched silicone oils not only have excellent low-temperature properties, but also can have three or more units of terminal functional groups in one molecule. (See, for example, Japanese Patent Publication Nos.
9-43515 and 59-43394). In recent years, it has been practiced to greatly improve the defoaming durability by using it as a component of a silicone antifoaming agent (Japanese Patent Laid-Open No. Hei 5-271689).

Conventionally, as a method for producing a branched silicone oil, a method comprising condensing a hydrolyzate of an alkyltrichlorosilane and a dialkylpolysiloxane using an equilibration catalyst (European Patent No. 31532), R ₃ Si
A method of reacting an organopolysiloxane having a hydroxyl group composed of O _1/2 unit and SiO ₂ unit with a diorganopolysiloxane having silanol groups at both ends with a condensation catalyst or an equilibration catalyst (No. 217501); A method in which diorganopolysiloxane and a vinyl monomer or a diorganopolysiloxane having a vinyl group are mixed and reacted using a radical initiation catalyst (see 273448).
No.) are known.

[0004] However, these production methods have disadvantages in that the characteristics of the oil are not constant because the finished viscosity varies due to the nature of the reaction. There is also a method in which an alkyltrimethoxysilane or a hydrolyzed condensate thereof is used as an RSiO _3/2 unit source to carry out an equilibrium reaction with a dialkylpolysiloxane. Disadvantageously, the desired product cannot be obtained stably. Further, when a reaction product having a hydrogen-silicon bond is used, when a reaction is performed using a basic catalyst as a catalyst, hydrogen gas is generated, and therefore, a method for producing a branched silicone oil having a hydrogen-silicon bond is as follows. It was especially difficult.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a branched silicone oil having stable physical properties because it does not contain a reactive group such as an alkoxy group, particularly a branched silicone oil having a hydrogen-silicon bond. It is to provide a method for stable production.

[0006]

The subject of the present invention is the following chemical formula 1

Embedded image Chemical formula 2 below

Embedded image Chemical formula 3 below

Embedded image And the following chemical formula 4:

Embedded image A first organopolysiloxane represented by at least one chemical formula selected from the group consisting of

Embedded image Is mixed so that the weight ratio of the second organopolysilyloxane to 100 parts by weight of the first organopolysilyloxane is 0.1 to 100 parts by weight, and the presence of an acidic catalyst A method for producing a branched silicone oil in which the organopolysilyloxane mixture is condensed and equilibrated below (wherein R ¹ , R ² ,
R ³ , R ⁴ and R ⁵ may be the same or different from each other, and a monovalent hydrocarbon group having 1 to 20 carbon atoms, m is 3 to
7, k is 1 to 7, 1 is 0 to 6, n and p are each 0 or more, q is 1 or more, i is 1 to 100, and j is 0 to 100. ).

Further, i is 2 and j is 0.
You may. Further, in the above production method, the acidic catalyst
Selected from the group consisting of sulfuric acid, hydrochloric acid, and organic sulfonic acids
At least one selected acidic catalyst, said condensation catalyst comprising:
After performing the equilibration reaction at room temperature,
A step of neutralizing the catalyst may be included. Further, the first o
The luganopolysiloxane is represented by Formula 2 and Formula 4
Represented by at least one chemical formula selected from the group consisting of
At least 0.1% by weight of the organopolysiloxane
May be included. The invention also relates to monofunctional [R₃SiO
_1/2] / Bifunctional ([R₃SiO_2/2] And [RH
SiO_2/2]) / Trifunctional [RSiO _3/2] = 0.
5-15 / 70-99 / 0.5-15 (atomic ratio of silicon
(%)) (Branch type silicone oil having the structure
Wherein R may be the same or different,
It is a group determined by the organopolysiloxane of the material. )
Is a method for producing the above.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Organopolysiloxanes represented by the above Chemical Formulas 1 to 4 are manufactured industrially and are commercially available. For example, as Chemical Formula 1, Sx manufactured by Shin-Etsu Chemical Co., Ltd.
-4, Chemical formula 2 as KF-99 manufactured by Shin-Etsu Chemical Co., Ltd.
02, KF-97 manufactured by Shin-Etsu Chemical Co., Ltd. as Chemical Formula 3.
01 and KF-9 manufactured by Shin-Etsu Chemical Co., Ltd.
9 and others. The organopolysiloxane represented by Chemical Formula 5 can be produced, for example, by a known method such as a dehydrogenation reaction of the organopolysiloxane represented by Chemical Formula 4 with water in the presence of a palladium-carbon catalyst. .

Specifically, R in these chemical formulas 1 to 5
¹ , R ² , R ³ , R ⁴ , and R ⁵ may be the same or different, and each may be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group,
Octyl, nonyl, decyl, dodecyl, alkyl such as tetradecyl, hexadecyl, octadecyl, cycloalkyl such as cyclohexyl, alkenyl such as vinyl and allyl, phenyl and tolyl An aryl group, or a chloromethyl group in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, or the like, 3-chlorodelopyryl group, 3,3,3-trifluoropropyl Group,
At least one unsubstituted or substituted monovalent organic group having 1 to 20 carbon atoms selected from a cyanoethyl group and the like,
Preferably, 90 mol% or more of the monovalent organic groups are methyl groups.

Further, n and p + q are 10 to 1, respectively.
000 is preferred. i is 1 to 100. This is because those having a value of more than 100 have a high viscosity and are difficult to handle.
Desirably, it is 0. Also, j is from 0 to 100, and when j is larger than 100, R (0
H) This is because the content of the SiO- unit relatively decreases, and it is necessary to increase the blending amount, which is not efficient.
In particular, i is preferably 0 to 10.

The amount of the second organopolysiloxane represented by the chemical formula 5 is 100 parts by weight of the first organopolysiloxane.
It is 0.01 to 100 parts by weight, preferably 0.5 to 15 parts by weight based on parts by weight. If the amount is less than 0.01 part by weight, the low-temperature properties and defoaming properties of the obtained branched silicone oil become insufficient, and if it is more than 100 parts by weight, a fine gel-like substance is produced as a by-product.

[0012] The structure of the finally obtained branched silicone oil, monofunctional _{[R 3 SiO 1/2]} / bifunctional _{([R 2 SiO 2/2]} and _[RHSiO 2/2]) /
Trifunctionality [RSiO _3/2 ] = 0.5-15 / 70-9
9 / 0.5 to 15 (atomic ratio of silicon (%);
R may be the same or different, and is a group determined by the starting organopolysiloxane. ) Is preferably set. By doing so, it is possible to obtain a branched organopolysiloxane exhibiting excellent low-temperature characteristics and defoaming characteristics. The viscosity of the branched organopolysiloxane obtained in this case is about 10 to 50,000 mPa · S at 25 ° C.

The reaction in the present invention includes a step of conducting a condensation and equilibration reaction at room temperature in the presence of an acidic catalyst, and a step of further neutralizing the acidic catalyst. These acidic catalysts mainly carry out a hydroxyl group condensation reaction and an accompanying equilibrium reaction.
At least one selected from the group consisting of inorganic acids such as sulfuric acid and hydrochloric acid, and organic acids such as organic sulfonic acid and carboxylic acid.
Various acidic catalysts are used, preferably sulfuric acid, hydrochloric acid and organic sulfonic acids, more preferably sulfuric acid. The addition weight of this acidic catalyst to the whole organopolysiloxane is 0.5 to
It is 10% by weight, preferably 1 to 7% by weight.

The catalyst is preferably added in two or more portions in order to prevent the fine gel-like substance from being formed as a by-product. That is, to the siloxane, a small amount of the above-mentioned acidic catalyst is first added, and the mixture is stirred at room temperature for 1 to 5 hours.
This is a method of stirring for 10 hours. In this case, the amount of the acidic catalyst to be added first is usually 0.02 to 2 parts by weight, preferably 0.05 to 1 part by weight.

After adding all the acidic catalyst and stirring for 1 to 10 hours, water is added. This is because the sulfonyl group is bonded to the terminal group of the siloxane, which is converted into a hydroxyl group and further condensed. The amount of water added
If the amount is too small or too large with respect to the acidic catalyst, the above reaction becomes difficult to occur. Therefore, the amount is 20 to 60 parts by weight, preferably 30 to 50 parts by weight, based on 100 parts by weight of the acidic catalyst. After addition of water, the mixture is further stirred at room temperature for 0.5 to 3 hours to terminate the condensation reaction. After separating the spent acid, the remaining acidic catalyst is subjected to neutralization and dehydration. The neutralizing agent is not particularly limited as long as it is suitable for this purpose, but sodium carbonate, sodium hydroxide, sodium hydrogen carbonate, potassium carbonate, potassium hydroxide and the like are preferable. At this time, the addition of a dehydrating agent such as sodium sulfate is also effective in some cases for the subsequent filtration and purification.

[0016]

According to the present invention, a branched silicone oil having stable physical properties can be obtained because it does not contain an alkoxy group or the like which is not easily converted, which can be a terminal group, and is a simple method. Further, a branched silicone oil having a hydrogen-silicon bond, which is difficult to obtain when a basic catalyst is used, can be obtained.

[0017]

The present invention will be described in more detail with reference to the following examples.
However, it is not intended that the present invention be limited to these.
Absent. Unless otherwise specified, “%” means “% by weight”.
means.Example 1  1,1,1,3,5, as organopolysiloxanes
7,7,7-octamethyl-3,5-dihydroxytet
62.9 g of lasiloxane, octamethylcyclotetracy
400 g of roxane and an average structural formula represented by the following chemical formula 6

[0018]

Embedded image

Methylhydrosiloxane represented by the formula
Using 7 g, 1.5 g of 97% sulfuric acid (manufactured by Ishizu Pharmaceutical Co., Ltd.) as an acidic catalyst was added at room temperature, and the mixture was stirred for 2 hours. Then, 13.5 g of 97% sulfuric acid was further added, and the mixture was stirred at room temperature for 6 hours. Then, after adding 7.5 g of water and stirring at room temperature for 2 hours,
After separating the waste acid, 15 g of sodium hydrogen carbonate and 15 g of sodium sulfate were added, and the mixture was further stirred for 2 hours. After confirming the neutrality with PH test paper, the mixture was filtered under pressure to obtain a branched silicone oil having a hydrogen-silicon bond and a viscosity at 25 ° C of 60 mPa · S. This was subjected to structural analysis by ²⁹ Si-NMR. [(CH ₃ ) ₃ SiO _1/2 ] /
[(CH ₃ ) ₂ SiO _2/2 ] / [CH ₃ HSiO
_2/2 ] / [CH ₃ SiO _3/2 ] = 6.4 / 79.0.
/8.8/5.8 (mol%).

[0020]Example 2  1,1,1,3,5, as organopolysiloxanes
7,7,7-octamethyl-3,5-dihydroxytet
33.7 g of lasiloxane and octamethylcyclote
Example 1 was repeated except that 429.5 g of Torasiloxane was used.
Similarly, the viscosity at 25 ° C. is 200 mPa · S
Obtaining a branched silicone oil having a hydrogen-silicon bond
Was. this²⁹When the structure was analyzed by Si-NMR
[(CH₃) ₃SiO_1/2] / [(CH₃)₂SiO
_2/2] / [CH₃HSiO_2/2] / [CH₃SiO
_3/2] = 3.5 / 84.2 / 9.2 / 3.1 (mol
%).

[0021]Example 3  1,1,1,3,5, as organopolysiloxanes
7,7,7-octamethyl 3,5-dihydroxytetra
33.7 g of siloxane and octamethylcyclotetra
Same as Example 1 except that 470.5 g of siloxane was used
And the viscosity at 25 ° C is 200 mPa · S.
Mold silicone oil was obtained. this²⁹By Si-NMR
When the structure was analyzed, [(CH₃)₃SiO_1/2] /
[(CH₃)₂SiO_2/2] / [CH₃Si
O_3/2] = 3.4 / 93.2 / 3.4 (mol%)
It was good.

[0022]Comparative Example 1  1,1,1,3,5, as organopolysiloxanes
7,7,7-octamethyl 3,5-dihydroxytetra
62.9 g of siloxane, octamethylcyclotetrasilo
400 g of xane and methyl having an average structural formula of the above Chemical Formula 6
Potassium hydroxide using 38.7 g of hydrosiloxane
0.2g and mixed at 150-160 ° C
The gel was formed after 30 minutes.

Claims (5)

[Claims] 1. The following chemical formula 1 The following chemical formula 2 The following chemical formula 3 And the following chemical formula 4: A first organopolysiloxane represented by at least one chemical formula selected from the group consisting of: Is mixed so that the weight ratio of the second organopolysilyloxane to 100 parts by weight of the first organopolysilyloxane is 0.1 to 100 parts by weight, and the presence of an acidic catalyst A method for producing a branched silicone oil in which the organopolysilyloxane mixture is condensed and equilibrated below (wherein R ¹ , R ² ,
R ³ , R ⁴ and R ⁵ may be the same or different from each other, and a monovalent hydrocarbon group having 1 to 20 carbon atoms, m is 3 to
7, k is 1 to 7, 1 is 0 to 6, n and p are each 0 or more, q is 1 or more, i is 1 to 100, and j is 0 to 100. ). 2. The method according to claim 1, wherein i is 2 and j is 0. 3. The method according to claim 1, wherein the acidic catalyst is at least one acidic catalyst selected from the group consisting of sulfuric acid, hydrochloric acid, and organic sulfonic acid. 3. The production method according to claim 1, further comprising a step of neutralizing the acidic catalyst. 4. The composition of claim 1, wherein the first organopolysiloxane comprises at least 0.1 part by weight of an organopolysiloxane represented by at least one chemical formula selected from the group consisting of Chemical Formulas 2 and 4. 4. The production method according to any one of 3. 5. The monofunctional _{[R 3 SiO 1/2]} / difunctional _{([R 2 SiO 2/2} ] and _{[RHSiO 2/2])}
/ Trifunctionality [RSiO _3/2 ] = 0.5-15 / 70-
A branched silicone oil having a structure of 99 / 0.5 to 15 (silicon atomic ratio (%)) (wherein R may be the same or different, and is a group determined by a raw material organopolysiloxane; The method according to any one of claims 1 to 4 for producing (a).