JPH0465429A - Polysilethylene siloxane - Google Patents

Abstract

PURPOSE:To provide the title new polymer of a specific formula, capable of giving rubber cured products highly resistant to acids, alkalis etc. and also excellent in mechanical strength. CONSTITUTION:The objective polymer of formula I (R is 1-8C monovalent hydrocarbon: n is 10 - 1000). The present polymer can be synthesized through the following process: a five-membered cyclic silethylene siloxane of formula III obtained by hydrolysis of a dichlorosilane of formula II is put to ring opening polymerizaton at pref. 50 - 150 deg.C using water as chain transfer agent in the presence of a polymerization catalyst such as an alkali metal hydroxide or silanolate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a novel polysilethylene siloxane that has not been described in any literature.

(Prior art) Dimethylpolysiloxane has excellent heat resistance, cold resistance, and weather resistance, as well as excellent properties such as rubber elasticity, mold release properties, and electrical properties, and is used as the main component of various rubber materials, coating materials, etc. It is used in a wide range of fields such as building materials, transportation equipment, home appliances, and office equipment.

Such characteristics of dimethylpolysiloxane originate from the fact that the siloxane bond in the main chain has a large bond energy, has ionic bonding properties, and the intermolecular cohesive force of the siloxane molecules is small.

(Problems to be Solved by the Invention) However, dimethylpolysiloxane has drawbacks such as its main chain being easily cleaved by ionic reagents such as acids and alkalis, and its mechanical strength properties being unsatisfactory. .

Accordingly, an object of the present invention is to provide a novel polysiloxane compound that eliminates the above-mentioned drawbacks of dimethylpolysiloxane.

(Means for achieving the object) The polysilethylene siloxane of the present invention has the following general formula (
1) In the formula, R represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, the plurality of R's may be the same or different groups, and n is an integer of 10 to 1,000. There is, expressed as.

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

In the above general formula (1), the group R has 1 to 8 carbon atoms.
A monovalent hydrocarbon group, specifically, a lower alkyl group having 8 or less carbon atoms such as a methyl group, an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, a vinyl group, an allyl group, Alkenyl groups such as isopropenoxy groups, aryl groups such as phenyl groups, tolyl groups, naphthyl groups,
Examples include aralkyl groups such as benzyl group and 2-phenylethyl group. These plural R's may be the same group or different groups.
In the present invention, the most preferred R is a lower alkyl group, particularly a methyl group.

Further, in the general formula CI), 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 500,000 at 25°C. cSt, preferably 1,00
It ranges from 0 to 100,000 cSt.

Although the polysilethylene siloxane of the present invention can be synthesized by various methods, it is typically synthesized by the following general formula (II), RR CI-Si-CHzCHz-5iO-CI (
If) RR where R is as described above, a method of hydrolyzing dichlorosilane represented by, and the following formula (n[) obtained thereby, where R is as described above, represented by The five-membered cyclic silethylene siloxane can be synthesized by ring-opening polymerization using water as a chain transfer agent.

This ring-opening polymerization is generally carried out in the presence of a polymerization catalyst.
It is carried out by heating to a temperature of 0 to 150°C. As the polymerization catalyst to be used, hydroxides and syralates of alkali metals such as lithium, potassium, and sodium are preferably used, and in addition, acid catalysts and alkali catalysts commonly used for ring-opening polymerization of dimethylpolysiloxane are used. etc. can also be used. Although the polymerization catalyst varies depending on its type, it is generally preferable to use it in a proportion of 0.001 to 1 part by weight per 100 parts by weight of the 5-membered cyclic silethylene siloxane.

Polysilethylene siloxane The thus obtained polysilethylene siloxane of the present invention has a silethylene bond and a siloxane bond in the main chain, and a silanol group at both ends, as represented by the above-mentioned general 2 (T). have. This polysilethylene siloxane is a liquid polymer that is excellent in properties such as chemical resistance, water repellency, and electrical properties, and is extremely useful as a main component of elastomers with high strength and high elongation. For example, a cured rubber product having the above characteristics can be obtained by curing the polysilethylene siloxane of the present invention by a crosslinking reaction applied to ordinary silicone compounds.

(Example) 100 g (0,625 mol) of cyclic siloxane represented by the following formula, 10 g (0,625 mol) of acetonitrile, and 37.5 μm of water ( 2,08xlO-'mol) was charged and heated to 95°C while stirring.

Next, add 0.1 g of tetraglyme and S
When potassium syralate was added in such an amount that the ratio was 4.000, heat was generated after 5 minutes and the internal temperature was 10
The temperature rose to 5℃. After the mixture was aged for 3 hours at a bath temperature of 100°C, tetrachloroethane Ig was added as a neutralizing agent, and further aged 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. This solution was heated in a pressurized furnace, and the furnace liquid was stripped under reduced pressure using an evaporator at 100° C. for 2 hours to obtain 91.2 g of an oily substance.

The viscosity of this oil at 25°C was 4.500 cSt.

When this oil was analyzed by GPC, OH group amount infrared absorption spectrum, and 'H-NMR, the following results were obtained.

GPC; Measuring equipment: Tosoh Corporation HLC-8020 Measuring conditions Column: G2500 + G4000 (1 each) Solvent: Freon-113 Flow rate: 111/sin Detector: Differential refractometer Temperature: 35°C The chart is shown in Figure 1 .

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

OH group amount 0.04 mol/100g 'H-NMR, CCI! , 4, internal standard CHCl 3
δ(ppll) 0.16 (s, 5i-CH3,12H) 0.51
(S, 5i-CI(z, 4H) infrared absorption spectrum; a chart is shown in FIG. 2.

Si-0: 1060C1+1-'Si-CH3
+1255C111-' From the above results, it was confirmed that the above oil was a polymer represented by the following formula in FIG.

(Effects of the Invention) According to the present invention, a novel polysilethylene siloxane compound capable of forming a cured rubber product having excellent resistance to acids, alkalis, etc. and excellent mechanical strength can be obtained. It was done.

[Brief explanation 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. [TIME]

Claims (1)

[Claims] (1) The following general formula [I], ▲Mathematical formula, chemical formula, table, etc.▼[I] In the formula, R represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, and multiple R's are the same as each other. or may be a different group, n is an integer from 10 to 1,000, polysilethylene siloxane represented by: