JPH0615614B2 - Polysilethylene siloxane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field The present invention relates to novel polysilethylene siloxanes which have been extensively published in the literature.

(Prior Art) Dimethylpolysiloxane is excellent in heat resistance, cold resistance, and weather resistance, and also has excellent properties such as rubber elasticity, releasability, and electrical characteristics. As a main component of various rubber materials and coating materials, It is used in a wide range of fields such as building materials, transportation equipment, home appliances, and office machines. Such characteristics of dimethylpolysiloxane are derived from the fact that the bond energy of the siloxane bond, which is the main chain, is large, it has ionic bondability, and the intermolecular cohesive force of siloxane molecules is small.

(Problems to be Solved by the Invention) However, dimethylpolysiloxane has drawbacks such that the main chain is likely to be cleaved by an ionic reagent such as acid or alkali, and mechanical strength characteristics are unsatisfactory. .

Therefore, an object of the present invention is to provide a novel polysiloxane compound in which the above-mentioned drawbacks of dimethylpolysiloxane are eliminated.

(Means for Achieving the Object) The polysilethylene siloxane of the present invention has the following general formula [I]: In the formula, R represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, plural Rs may be the same or different groups, and n is an integer of 10 to 1,000. .

That is, the present invention has succeeded in eliminating the above-mentioned drawbacks of dimethylpolysiloxane by introducing a silethylene bond into the siloxane main chain.

In the above general formula [I], the group R has 1 to 8 carbon atoms.
Specific examples of the monovalent hydrocarbon group include a methyl group, an ethyl group, a propyl group and the like, a fixed alkyl group having 8 or less carbon atoms, a cycloalkyl group such as a cyclohexyl group, a vinyl group, an allyl group, Examples thereof include alkenyl groups such as isopropenoxy group, aryl groups such as phenyl group, tolyl group and naphthyl group, aralkyl groups such as benzyl group and 2-phenylethyl group. The plurality of Rs may be the same group or different groups. In the present invention, the most preferred R is a lower alkyl group, especially a methyl group.

Further, in the general formula [I], n is an integer of 10 to 1,000, and in relation to such a value of n, the polysilethylene siloxane of the present invention has a viscosity of 25 to 500,000c at 25 ° C.
St, preferably in the range of 1,000-100,000 cSt.

Production Method The polysilethylene siloxane of the present invention can be synthesized by various methods, but typically, the following general formula [II], In the formula, R is as described above, and a 5-membered emotional silethylene siloxane represented by the following formula [III], In the formula, R is as described above, and can be synthesized by ring-opening polymerization using divinylsiloxane represented by:

This ring-opening polymerization is generally carried out in the presence of a polymerization catalyst at 50
It is performed by heating to a temperature of ~ 200 ° C. As the polymerization catalyst to be used, hydroxides and silanolates of alari metals such as lithium, potassium and sodium are preferably used, and in addition, acid catalysts and alkali catalysts used for ring-opening polymerization of ordinary dimethylpolysiloxane are also used. Can be used. Such a polymerization catalyst varies depending on its type,
Generally, it is preferable to use 0.001 to 1 part by weight per 100 parts by weight of 5-membered cyclic silethylene siloxane. The above-mentioned chain transfer agent is preferably used in a proportion of 0.1 to 15 parts by weight per 100 parts by weight of 5-membered cyclic silethylene siloxane.

Polysilethylene Siloxane The thus obtained polysilethylene siloxane of the present invention has a molecular structure represented by the above general formula [I], and has a high level of chemical resistance, water repellency and electrical characteristics. It is a liquid polymer that is extremely useful as the main component of a strong and highly stretchable elastomer. For example, a rubber cured product having the above-mentioned properties can be obtained by curing the polysilethylene siloxane of the present invention by a crosslinking reaction applied to a usual silicone compound.

(Example) Example 1 A 300 ml four-necked flask equipped with a cooling tube, a stirring blade, and a thermometer was charged with the following formula, 100 g (0.625 mol) of cyclic siloxane represented by 0.35 g (2.08 × 10 ⁻³ mol) of divinyldisiloxane represented by was charged and heated to 100 ° C. with mixing and stirring.

Next, potassium-silanolate was added to this mixed solution as Si.
When added so that the / K ratio became 5,000, heat was generated after 2 minutes and the internal temperature rose to 150 ° C. Bath temperature 100 ℃ as it is
After aging for 3 hours, 1 g of tetrachloroethane was added as a neutralizing agent, and further aging was performed at 100 ° C. for 1 hour.

Next, the mixture was cooled to room temperature, 0.5 g of activated carbon was added and stirred for 1 hour, and then 50 g of toluene was added to dissolve the produced polymer. The solution was pressurized, and the solution was vacuum stripped at 100 ° C. and 3 mmHg for 2 hours by an evaporator to obtain 90.5 g of an oily substance.

The viscosity of this oil at 25 ° C. was 4,881 cSt.

Also, this oil was analyzed by GPC, vinyl group quantification, infrared absorption spectrum, ¹ H-NMR,
The results were as follows.

GPC; Measuring instrument Tosoh Corp. HLC-8020 Measuring conditions Column: G2500 + G4000 (1 each) Solvent: Freon-113 Flow rate: 1 ml / min Detector: Differential refractometer Temperature: 35 ° C The chart is shown in Fig. 1. .

As is clear from this chart, a monodisperse pattern was shown.

Vinyl group determination; 0.004 mol / 100g ¹ H-NMR; internal standard CHCl ₃ δ (ppm) 0.15 (s, Si-CH ₃ , 12H) 0.50 (s, Si-CH ₂ , 12H) infrared absorption spectrum in CCl ₄ A chart is shown in FIG.

Si-O: 1060 cm ^-1 Si-CH ₃ : 1255 cm ^{-1 From the} above results, the above oil was It was confirmed that the polymer was represented by

(Effect of the Invention) According to the present invention, a novel polysilethylenesiloxane compound capable of forming a rubber cured product having excellent resistance to acids, alkalis and the like and having excellent mechanical strength is obtained. Was given.

[Brief description of drawings]

FIG. 1 is a diagram showing a GPC chart of the polymer synthesized in Example 1, and FIG. 2 is a diagram showing an infrared absorption spectrum of the polymer synthesized in Example 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sai Minami 2-13-1, Isobe, Gunma Prefecture Annabe City Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Toshio Takago Annaka Gunma Prefecture 2-13-1 Ichiisobu Shin-Etsu Chemical Co., Ltd. Silicon Electronic Materials Research Laboratory (56) References JP-A-55-116728 (JP, A)

Claims (1)

[Claims] 1. The following general formula [I]: In the formula, R represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, plural Rs may be the same or different from each other, and n is an integer of 10 to 1,000. Polysilethylene siloxane.