JPH09221489A - Organohydrogen cyclotetrasiloxane containing fluorine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound as a specific organohydrogen cyclotetrasiloxane, capable of markedly improving the physical characteristics of a produced polymer in the case of using the compound as a cross-linking agent for a silicone containing fluorine. SOLUTION: This new cyclotetrasiloxane containing fluorine is expressed by formula I [(n) is an integer of 4-12; (m) is an integer of 1-3] and can markedly improve the physical characteristics of an obtained silicone polymer containing fluorine in the case of using the compound as a cross-linking agent for a silicone containing fluorine. The compound is obtained e.g. by a hydrosilylation reaction of methylhydrogen cyclotetrasiloxane expressed by Formula II with an unsaturated compound containing fluorine expressed by the formula: F-(CF2 )n -CH2 -CH=CH2 in the presence of a platinum catalyst such as chloroplatinic acid, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel fluorine-containing organohydrogencyclotetrasiloxane,
Especially when used as a crosslinking agent for fluorine-containing silicone,
The present invention relates to a fluorine-containing organohydrogencyclotetrasiloxane capable of significantly improving the physical properties of the obtained fluorine-containing silicone polymer.

[0002]

2. Description of the Related Art Conventionally, general formula (2):

[0003]

Embedded image

A fluorine-containing organohydrogencyclotetrasiloxane represented by the formula: wherein R _f is a C ₄ -C ₁₂ perfluoroalkyl group, and p and q are integers of 3-10. It is generally and substantially disclosed in JP-A 7-53719. However, neither a specific compound nor its usefulness is described at all.

[0005]

Therefore, an object of the present invention is to provide a novel fluorine-containing silicone polymer which can remarkably improve the physical properties of the obtained fluorine-containing silicone polymer when used as a crosslinking agent for the fluorine-containing silicone. A fluorine organohydrogencyclotetrasiloxane is provided.

[0006]

That is, the present invention provides a compound represented by the general formula (1):

[0007]

Embedded image

[Wherein n is an integer of 4 to 12 and m is 1
Is an integer of 3 to 3].

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The fluorine-containing organohydrogencyclotetrasiloxane of the present invention, as described above,
It is represented by the general formula (1). In the general formula (1), the carbon atom number (n) of the perfluoroalkyl group is an integer of 4 to 12, and preferably an integer of 4 to 8. When n is less than 4, the effect of the fluorine group is small, and the compatibility with, for example, fluorine-containing silicone becomes poor. On the other hand, when it is greater than 12, the crystallinity of the fluorine portion is too strong, and the compatibility with, for example, fluorine-containing silicone becomes poor. The perfluoroalkyl group is
Trimethylene group _{(-CH 2 -CH 2 -CH 2 -} ) bonded to a silicon atom via a. The m is an integer of 1 to 3, preferably 1.

The following are specific examples of the fluorine-containing organohydrogencyclotetrasiloxane of the present invention.

[0011]

Embedded image

The fluorine-containing organohydrogencyclotetrasiloxane of the present invention has, for example, the formula (3):

[0013]

Embedded image

Methyl hydrogencyclotetrasiloxane represented by the following formula and the general formula (4): F- (CF ₂ ) _n -CH ₂ -CH = CH ₂ (4) [wherein n has the same meaning as described above] ] It is easily obtained by subjecting the unsaturated compound represented by the formula [1] to a hydrosilylation reaction in the presence of a catalyst. This unsaturated compound can be obtained, for example, by the method described in JP-A-48-34805.

The reaction molar ratio [(A) / (of the methylhydrogencyclotetrasiloxane represented by the formula (3) [(A)] and the unsaturated compound represented by the general formula (4) [(B)] B)]
Is determined by the desired value of m, and when m = 1, it is usually in the range of 1/1 to 3/1, preferably 1.5 / 1 to 2.5 /
It is in the range of 1. When m = 2, usually 0.3 / 1
~ 1/1 is sufficient, and when m = 3, usually 0.1 / 1 ~ 0.5 / 1
Is fine.

As the catalyst, any conventionally known catalyst can be used for the hydrosilylation reaction without particular limitation, and examples thereof include chloroplatinic acid, a salt of platinum and a complex of platinum. The amount of this catalyst may be a so-called catalytic amount, such as SiH in methylhydrogencyclotetrasiloxane represented by the formula (3).
Usually, 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mol (platinum metal conversion) is sufficient for 1 mol.

In the above reaction, a solvent may be used if necessary, and examples thereof include aliphatic hydrocarbons; aromatic hydrocarbons; halogen-substituted products thereof; alcohols and the like.

The above reaction is carried out under atmospheric pressure or in a closed system, by mixing both raw materials at once, or by mixing one raw material while dropping it into the other raw material. The reaction temperature may be usually 50 to 200 ° C, preferably 70 to 110 ° C. The reaction time is appropriately determined depending on the production scale and is usually 5 minutes to 10 hours. A preferred production method is to charge methylhydrogencyclotetrasiloxane represented by the formula (3) and the catalyst into a reactor under atmospheric pressure, and then heat to a temperature of 80 to 120 ° C.
In this method, the unsaturated compound represented by (4) is added dropwise. The progress of the reaction can be confirmed by gas chromatography. After completion of the reaction, the desired product may be isolated by distillation or the like, if necessary.

Utility The fluorine-containing organohydrogencyclotetrasiloxane of the present invention is used, for example, as a crosslinking agent. That is, the fluorine-containing silicone polymer can be produced by subjecting the organopolysiloxane having an aliphatic unsaturated bond and the fluorine-containing organohydrogencyclotetrasiloxane of the present invention to a hydrosilylation reaction. In particular, when the organopolysiloxane having an aliphatic unsaturated bond has a fluorine-containing group (that is, when it is a fluorine-containing silicone), the compatibility is high, and therefore the effect as a crosslinking agent is excellent. Then, the physical properties of the obtained fluorine-containing silicone polymer can be remarkably improved. Further, the fluorine-containing organohydrogencyclotetrasiloxane of the present invention can be ring-opening polymerized alone to produce a silicone polymer having a fluorine-containing group and a hydrosilyl group. Since these fluorine-containing silicone polymers are excellent in solvent resistance, cold resistance, water and oil repellency, various applications are expected. For example, packing, gaskets that come into contact with industrial oil or fuel oil,
Examples include diaphragms and hoses, as well as chemical reactor seals and packings. Further, the fluorine-containing organohydrogencyclotetrasiloxane of the present invention can introduce a functional substituent into the hydrosilyl group, and is therefore useful as an intermediate for the production of various functional organosilicon compounds. Examples of the functional substituent include a glycidyl group and a trimethoxysilyl group. The resulting functional fluorine-containing organohydrogencyclotetrasiloxane is useful, for example, as an additive for improving the adhesiveness of the precursor and the fluorine-containing silicone.

Hereinafter, the present invention will be described with reference to examples.

[0021]

【Example】

Example 1 A glass reactor having an internal volume of 300 mL equipped with a stirrer, a cooling tube, a thermometer and a dropping funnel was charged with the formula (3):

[0022]

[Chemical 6]

120 g (0.50 mol) of methyl hydrogen cyclotetrasiloxane represented by: 60 g of toluene, chloroplatinic acid and the formula:

[0024]

Embedded image

0.078 g (2.0 × 10 ^-6 mol of platinum metal equivalent) of a toluene solution of a complex with vinylsiloxane (platinum content: 0.5% by weight) represented by: was charged and heated to 100 ° C.
Thereafter, 115 g (0.25 mol) of an unsaturated compound represented by the formula: CH ₂ = CHCH _2- (CF ₂ ) ₈ -F was added dropwise with a dropping funnel over 2 hours. After the completion of dropping, the temperature was maintained at the same temperature for 10 minutes, and the disappearance of the unsaturated compound was confirmed by gas chromatography.

232 g of the reaction product thus obtained was subjected to simple distillation and redistillation to obtain the compound of the formula (7): 103 to 104 ° C./3 mmHg.

[0027]

Embedded image

110 g (purity 97%) of a fluorine-containing organohydrogencyclotetrasiloxane represented by the following formula was obtained.
The NMR and IR data of this product are shown in Table 1, and the IR spectrum is shown in FIG.

Example 2 In Example 1, the formula: CH ₂
= CHCH _2- (CF ₂ ) ₈ -F instead of the unsaturated compound represented by
The same operation was performed except that an unsaturated compound represented by the following formula: CH ₂ = CHCH _2- (CF ₂ ) ₄ -F was used, and the formula (8):

[0030]

Embedded image

A fluorine-containing organohydrogencyclotetrasiloxane represented by the following formula was obtained.

[0032]

[Table 1]

[0033]

According to the present invention, a novel fluorine-containing organohydrogencyclotetrasiloxane is provided. This fluorine-containing organohydrogencyclotetrasiloxane, when used as a crosslinking agent for fluorine-containing silicone, can remarkably improve the physical properties of the obtained fluorine-containing silicone polymer and is industrially useful.

[Brief description of drawings]

FIG. 1 is an IR spectrum of the fluorine-containing organohydrogencyclotetrasiloxane of Example 1.

Claims (1)

[Claims] 1. General formula (1): [In the formula, n is an integer of 4 to 12 and m is an integer of 1 to 3] Fluorine-containing organohydrogencyclotetrasiloxane.