JP2666371B2 - Method for producing fluorosilicone oil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a fluorosilicone oil.

[Prior Art] Conventionally, it is known that a fluorosilicone oil homopolymer having a fluoroalkyl group can be obtained by polymerization of a cyclic polysiloxane using an acid or an alkali as a catalyst. For example, JP-B-35-8345, JP-B-47-47880,
JP-A-50-132100 discloses a polymerization method by acid contact.
JP-A-50-143900, JP-A-56-92921 and JP-B-57-59855 disclose a polymerization method using an alkali catalyst. On the other hand, a method for producing a copolymer comprising a siloxane component having a trifluoropropyl group as a fluoroalkyl group and a siloxane component not containing a fluoroalkyl group is disclosed in JP-A-51-134795 and JP-A-51-134796. Kaisho 51
No. 134798, JP-A-51-141000, and JP-B-55-50056.

However, these are all polymerization methods using an alkali catalyst, and when this method was applied to the production of a copolymer oil containing a long-chain fluoroalkyl group, it was found that the viscosity was difficult to adjust.

Further, Japanese Patent Application Laid-Open No. 62-71506 discloses a method for synthesizing a copolymer oil containing a long-chain fluoroalkyl group. It consists of two reaction steps, first hydrolyzing long-chain fluoroalkyl group-containing dichlorosilane in the presence of the monomer to be copolymerized and an aqueous alkali solution, and then reacting the hydrolyzate with a chain transfer agent. Is added, and a polymerization reaction is caused by trifluoromethanesulfonic acid. This method is complicated because it involves two reaction steps. In addition, in the first-stage reaction, cyclic siloxanes or linear siloxanes containing tetramers or longer containing a long-chain fluoroalkyl group relatively inactive to trifluoromethanesulfonic acid are generated. A remarkable molecular weight distribution occurs during the polymerization reaction, and in extreme cases, a large amount of volatile fraction is generated.

[Problems to be Solved by the Invention] Conventionally, when a cyclic siloxane having a trifluoropropyl group is polymerized to produce a fluorosilicone oil, a cyclic trisiloxane or a cyclic tetrasiloxane is usually opened in the presence of an alkali catalyst. It had been polymerized.
However, when producing a fluorosilicone oil having a fluoroalkyl group longer than a trifluoropropyl group, there has been a problem that if polymerization is carried out using an alkali catalyst, the polymerization does not proceed or is extremely slow.
It is also known that polymerization proceeds by polymerization in a mixed system of an alkali catalyst and a crown ether or the like, and that a polymer is obtained.However, in this method, it is difficult to control the molecular weight. However, there is a problem that a large amount is easily generated.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and is 1 to 99.9 mol based on the total of the following cyclic trisiloxane (1) and the following cyclic siloxane (2). % (1),
0.1 to 99 mol% of (2) based on the sum of (1) and (2), and 0.01 to 99 mol% based on the sum of (1) and (2)
A process for producing a fluorosilicone oil characterized by reacting 50 mol% of a disiloxane (3) in the presence of trifluoromethylsulfonic acid.

Cyclic trisiloxane (1): RfCH ₂ CH ₂ — (Rf has 2 carbon atoms
Cyclic trisiloxane having a 2-perfluoroalkylethyl group represented by the following formula:

Cyclic siloxane (2): a cyclic siloxane represented by R ² R ³ SiO _n (R ² and R ³ are each a lower alkyl group or an aryl group, and n is an integer of 3 to 6).

In the present invention, the cyclic trisiloxane (1) is RfCH ₂ C
It has a 2-perfluoroalkylethyl group represented by H ₂ (Rf is a perfluoroalkyl group having 2 to 9 carbon atoms).

It is important that the cyclic trisiloxane (1) is a cyclic trimer. A cyclic compound having a tetramer or more such as a cyclic tetrasiloxane has extremely low ring-opening polymerization reactivity, and it is difficult to produce a substantially useful fluorosilicone oil. As the perfluoroalkyl group of the 2-perfluoroalkylethyl group, those having 2 to 9 carbon atoms are employed, and may be linear or branched. , Volatility and moisture resistance are preferred. Further, a perfluoroalkyl group having 3 to 6 carbon atoms, particularly 4 carbon atoms, is preferred from the viewpoint that the produced fluorosilicone oil has excellent heat resistance, cold resistance, and solvent resistance and is easy to produce. Examples of such a cyclic trisiloxane (1) include those represented by RfCH ₂ CH ₂ (R ¹ ) SiO ₃ . Here, Rf is the same as above,
R ¹ is a lower alkyl group or an aryl group. In particular, R ¹
Is preferably an alkyl group having about 1 to 3 carbon atoms or a phenyl group. When R ¹ is an alkyl group having an excessively large number of carbon atoms, solvent resistance and the like tend to decrease, which is not preferable. Most preferably, R ¹ is a methyl or phenyl group.

As the cyclic siloxane (2), those copolymerizable with the cyclic trisiloxane (1) described above are employed. Such a cyclic siloxane (2) is represented by R ² R ³ SiO _n . Here, R ² and R ³ are a lower alkyl group and an aryl group, respectively, and n is an integer of 3 to 6. R ² , R
³ may be the same or different groups, and particularly preferably an alkyl group having about 1 to 3 carbon atoms or a phenyl group. Further, the cyclic siloxane (2)
It is a cyclic siloxane of cyclic trimer to hexamer. If the cyclic siloxane is larger than the hexamer, the ring-opening polymerization reactivity is low, which is not preferable. Particularly, trimer or tetramer, that is, cyclic trisiloxane or cyclic tetrasiloxane is preferable.

In the present invention, the cyclic trisiloxane (1) and the cyclic siloxane (2) are each 1 to 99.9 with respect to the total of both.
The reaction is conducted in the range of 0.1 mol%, 0.1 to 99 mol%. In particular, 10 to 75 mol% and 25 to 90 mol% are preferable, respectively. In the method of the present invention, since the cyclic trisiloxane (1) and the cyclic siloxane (2) can be reacted at various ratios, the amount to be reacted can be appropriately selected according to the desired physical properties. .

In the present invention, disiloxane (3) is R ⁴ (CH
₃ ) ₂ SiOSi (CH ₃ ) R ⁵ is preferably employed. Here, R ⁴ and R ⁵ are each CH ₃ or Rf′CH ₂ CH ₂
And Rf 'is a perfluoroalkyl group having 1 to 9 carbon atoms. The disiloxane (3) in the present invention has a function of sealing the end of the produced fluorosilicone oil. Depending on the amount of the disiloxane (3),
The molecular weight of the produced fluorosilicone oil is adjusted. In particular, by employing disiloxane, a fluorosilicone oil having a stable molecular weight distribution and stable physical properties can be obtained, and other linear polysiloxanes cannot be employed. By adjusting the amount of disiloxane (3), fluorosilicone oils of various molecular weights or viscosities can be produced. In the present invention, the cyclic trisiloxane (1) and the cyclic siloxane (2) can be produced. The amount to be used can be appropriately determined in the range of 0.01 to 50 mol% based on the total amount. Especially 0.5-30
Molar% is preferred. The amount of the disiloxane (3) used is appropriately changed depending on the types of the cyclic trisiloxane and the cyclic siloxane, but the viscosity of the fluorosilicone oil to be produced is 50 to 10,000 centistokes (25 ° C.), especially 100 to 100 centistokes.
It is preferable to select so as to be about 3,000 centistokes (25 ° C.).

In the present invention, the above-mentioned cyclic trisiloxane (1), cyclic siloxane (2) and disiloxane (3) are reacted in the presence of a strong acid catalyst. Here, as the strong acid catalyst, those which are employed from fluoroalkyl sulfonic acids but have a fluoroalkyl group having an excessively large number of carbon atoms become solid at room temperature, and form cyclic trisiloxane (1), cyclic siloxane (2) and disiloxane. It is not preferable because the compatibility with (3) becomes small and the catalytic activity becomes low, which causes a problem that the reaction becomes extremely high or requires a long time. The strong acid catalyst in the present invention is trifluoromethylsulfonic acid (CF ₃ SO ₃ H). In the present invention, the use amount of the strong acid catalyst is not particularly limited, and an amount that can achieve a practical polymerization rate is employed. Preferably, it is used in an amount of 0.01 to 1% by weight based on the total amount of (1), (2) and (3).

The polymerization temperature is not particularly limited, but is usually from 0 ° C to 150 ° C, preferably from room temperature to 100 ° C. If the temperature is lower than room temperature, cooling is required, which is not only disadvantageous in energy but also slows down the reaction rate. Disiloxane (3) above 100 ° C
In the case of (CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ , since its boiling point is 100 ° C., the vapor pressure becomes high, which makes effective use difficult and also requires a pressure-resistant container. In addition, there is a problem that the viscosity varies depending on the reaction container.

The properties of the oil produced according to the present invention, such as surface tension and refractive index, can be accurately changed by changing the copolymer composition as described later. Therefore, a fluorosilicone oil having various physical properties in the application field of the finely divided silicone oil can be produced, and can be used without any particular limitation on its use conditions.

For example, a heat pump, lubricating property, oxidative stability, and inertness against rubber and plastics, etc. are used to make the oil of a vacuum pump excellent in heat resistance, cold resistance, lubricity, and viscosity-temperature characteristics. Etc., using traction oil,
Hydraulic oil such as brake oil and coupling oil, instrumentation for automobiles and aircraft, anti-vibration oil for player pickup, etc.
Utilizing properties such as lubricity in damper oils such as dash pot dampers and shock absorbers, and utilizing properties such as low surface tension as lubricants for thermal transfer recording receivers, magnetic recording media, magnetic heads, impregnated bearings, etc. Release agents, release agents, copying agents, roll compositions for electrophotographic machines or their surface coating agents, film blocking inhibitors for thermal transfer recording ink sheets, liquid crystal compositions, water and oil repellency, low surface tension, Oils, hair dyes, shampoos, cosmetics such as makeup cosmetics, lipsticks, hair cosmetics, antiperspirants, deodorants, etc., making use of their low reflectivity, flexibility, and being physiologically inert. For oils used in hair treatment agents such as rinses, and for oxygen-supplying ability, oils used in gel-like composition are used, and oil repellency, low reflection, flexibility, and lubricity are used. Finishing agent raw material, water repellent raw material Utilizes high-breakdown voltage, low hygroscopicity, etc. for fiber treatment agents such as deep color processing agents, sewing thread lubrication agents, etc., and heat resistant to transformer oil, condenser oil, cable oil, etc. A plastic as a leveling agent, an anti-blocking agent, an anti-color unevenness agent, an anti-yuzu skin agent, etc., utilizing a unique surface characteristic, etc., as a heat medium, utilizing excellent oxidation resistance and a low vapor pressure. Utilizes heat resistance, cold resistance, oxidative stability, lubricity, flexibility, etc. as additives to polymer materials such as paints, and rubber and resin plasticity, modifiers, heat resistance, chemical and physiological Inert, insoluble in many other substances, etc., used as defoamer, heat resistant, chemical resistant, water resistant, lubricating, etc. to use grease, compound base oil In addition, differential pressure gauge liquid of various other measuring instruments,
Foam stabilizer, compounding oil for wax, toner treatment agent, oil sealant, rust inhibitor, antistatic agent, anti-fog agent, cooling oil,
It can be used as an additive to pharmaceuticals, a polishing agent, a surface treatment agent for glass ceramics, powders and the like.

EXAMPLES Example _{1 [(C 4 F 9 CH} 2 CH 2) (CH 3) SiO] 3 20g, [(CH 3) 2 SiO]
₃ 20 g and (CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ 0.68 g were charged into a 400 ml flask under an argon atmosphere and kept at 70 ° C. 0.15g CF ₃ SO ₃
H was further added, and the mixture was stirred for 6 hours. As a result, a liquid having a substantially constant viscosity was obtained. This liquid was dissolved in 100 ml of 1,1,2 trifluorotrifluoroethane (hereinafter, referred to as R-113) at room temperature, and washed with water.

After drying the separated organic layer over MgSO _4, filtered over MgSO _4, remove the R-113 by an evaporator. Next, the obtained liquid was distilled at 200 ° C. under a reduced pressure of 1 mmHg to obtain 3.1 g of volatile matter and 34.7 g of liquid. This liquid had a viscosity of 300 centistokes at 25 ° C.

Example 2 The amount of (CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ in Example 1 was changed to 1.35.
An oil of 113 centistokes was obtained by the same operation except that the amount was changed to g, and an oil of 1,000 centistokes was obtained by adjusting the amount of (CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ to 0.36 g.
As described above, according to the present method, oils of various viscosities can be synthesized with good reproducibility by changing the amount of disiloxane as a chain transfer agent with respect to the charged amount of cyclic siloxane.

Comparative Example _{1 [(C 4 F 9 CH} 2 CH 2) (CH 3) SiO] 3 10.3g, [(CF 3 CH 2 C
H ₂ ) (CH ₃ ) SiO] ₃ 5.16 g, (CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ 0.915 g
And 16.4 mg of CF ₃ SO ₃ H were polymerized at 25 ° C. for 24 hours.
After the completion of the polymerization, 16.2 g of a copolymer was obtained by the same post-treatment as in Example 1 except that the distillation temperature was changed to 100 ° C. ¹ Hnmr and ¹⁹ Fnmr analyzes confirmed that this copolymer was a copolymer having substantially the same composition as the monomer composition used for the polymerization. The viscosity at 25 ° C. was 42 centistokes.

EXAMPLE _{3 [(C 4 F 9 CH} 2 CH 2) (CH 3) SiO] 3 20.3g, [(CF 3 CH 2 C
H ₂ ) (CH ₃ ) SiO] ₃ 10.6 g, [(CH ₃ ) SiO] ₃ 0.28 g, (C
When H ₃ ) ₃ SiOSi (CH ₃ ) ₃ 0.054 g and CF ₃ SO ₃ H 31.2 mg were subjected to polymerization and post-treatment in the same manner as in Example 2, 29.3 g of a copolymer was obtained. ¹ Hnmr and ¹⁹ Fnmr analyzes confirmed that this copolymer was a copolymer having substantially the same composition as the monomer composition used for the polymerization. The viscosity at 25 ° C is 20,0
It was 00 centistokes.

Comparative Example 2 CF ₃ SO ₃ H in Example 1 was replaced with KOH and N [CH ₂ CH ₂ OCH ₂ OC
H ₃ ] The same operation was carried out except that the equimolar complex of ₃ was used.
Volatiles and 83% liquid. The viscosity of the liquid was 3440 centistokes at 25 ° C. This is significantly higher than the theoretically expected viscosity (about 330 centistokes), indicating that CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ is not acting as a molecular weight regulator.

Example 4, the ratio of Comparative Example _{3 [(C 4 F 9 CH} 2 CH 2) (CH 3) SiO] 3 [(C 4 F 9 CH
_{2 CH 2) (CH 3)} SiO] 3 and [(CH _{3) 2} SiO] implementing those varied in the range of 1 to 99.9 mol% based on the total of ₃ likewise copolymerized as in Example 1 Example 4 or [(C ₄ F ₉ CH ₂ C
H ₂ ) (CH ₃ ) SiO] ₃ and [(CF ₃ CH ₂ CH ₂ ) (CH ₃ ) SiO] ₃
Comparative Example 1 by changing the total amount of
A fluorosilicone oil having a copolymerization ratio as Comparative Example 3 was obtained by copolymerization in the same manner as in Example 1. The measurement results of the surface tension and the refractive index of each oil are shown in FIG. 1 and FIG.

[Effect of the Invention] The production method of the present invention can easily produce a fluorosilicone oil having an arbitrary composition and viscosity. Therefore, it is extremely effective for producing fluorosilicone oil having various required physical properties in the application field of the finely divided silicone oil.

[Brief description of the drawings]

Figure 1 was obtained in Example _{4 (C 4 F 9 CH 2} CH 2) (CH 3) a SiO units and (CH ₃₎ fluorosilicone oil consisting of ₂ SiO units _{(C 4 F 9 CH 2 CH} 2 ) (CH ₃ ) SiO unit content (% by weight)
FIG. 2 is a graph showing the surface tension (dyn / cm) with respect to, and FIG. 2 shows the results obtained from the (C ₄ F ₉ CH ₂ CH ₂ ) (CH ₃ ) SiO unit and the (CH ₃ ) ₂ SiO unit obtained in Example 4. And the (C ₄ F ₉ CH ₂ CH ₂ ) (CH ₃ ) S obtained in Comparative Example 3
(C ₄ F ₉ CH ₂ CH ₂ ) (C) of fluorosilicone oil (symbol 2) consisting of iO units and (CF ₃ CH ₂ CH ₂ ) (CH ₃ ) SiO units
H ₃₎ is a graph showing the refractive index with respect to SiO unit content (wt%).

Claims (3)

(57) [Claims] 1 to 99.9 mol% of the total of the following cyclic trisiloxane (1) and the following cyclic siloxane (2), and 0.1 to 99 mol% of the total of (1) and (2). %
0.01 with respect to (2) and the sum of (1) and (2)
A method for producing a fluorosilicone oil, comprising reacting 50 mol% of disiloxane (3) in the presence of trifluoromethylsulfonic acid. Cyclic trisiloxane (1): RfCH ₂ CH ₂ — (Rf has 2 carbon atoms
Cyclic trisiloxane having a 2-perfluoroalkylethyl group represented by the following formula: Cyclic siloxane (2): a cyclic siloxane represented by R ² R ³ SiO _n (R ² and R ³ are each a lower alkyl group or an aryl group, and n is an integer of 3 to 6). 2. The method of claim 1, wherein the cyclic trisiloxane (1) is RfCH ₂ CH
^{_{2 (R 1) SiO 3 (}} Rf is a perfluoroalkyl group having 2 to 9 carbon atoms, R ¹ represents a lower alkyl group or an aryl group) The method of manufacturing according to claim 1, wherein the fluorosilicone oil is represented by. 3. The method according to claim 1, wherein the disiloxane (3) is R ⁴ (CH ₃ ) ₂ SiOSi (C
H ₃ ) ₂ R ⁵ (R ⁴ and R ⁵ are each CH ₃ or Rf′CH ₂ CH ₂ , R
f 'is a perfluoroalkyl group having 1 to 9 carbon atoms)
The method for producing a fluorosilicone oil according to claim 1 or 2, which is represented by the following formula: