JPH0341123A - Poly(disilene/ethylene) and its production - Google Patents

Abstract

PURPOSE:To produce easily the subject high-mol.wt. polymer composed of alternating ethylene parts and Si-Si bonds under mild conditions by polycondensing a specified disilylethane with an alkali metal by using a diluent. CONSTITUTION:A 1-silyl-2-silylethane of formula I [wherein R<1>-R<4> are each a (substituted) alkyl; and X is Cl, Cr or I] is polycondensed with an alkali metal by using a diluent to produce a poly(disilene/ethylene) wherein the main chain is represented by formula II (wherein (n)>=3), and the substituents on the silicon atoms in each repeating unit of the main chain are alkyls. According to the above process, the polymer having alternating ethylene parts and Si-Si bonds can be produced easily under mild conditions, and a polymer of a mol.wt. >150000 which could not be obtained by a conventional process can be obtained. The above polymer is useful as a material of silicon carbide ceramics, as a functional polymer such as a photoreactive polymer, or as a chemical-resistant polymer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to poly(disilene-ethylene), which is a type of polycarbosilane, in which disylene moieties and ethylene moieties are arranged alternately in the main chain, and their This relates to a manufacturing method. Poly(disilene-ethylene)s are useful as raw materials for silicon carbide ceramics, as functional polymers such as photoreactive polymers, and as chemical-resistant polymers.

[Prior art and its problems] Conventionally, only the following two methods are known as methods for producing poly(disilene-ethylene).

Fll, the vapor of 2-bis(chlorosilyl)ethane is brought into contact with the vapor of metallic sodium or potassium under reduced pressure and at a temperature above 250°C to form 1,2-disilacyclobutane, which is condensed at a low temperature, which is then Polymerize at temperatures above room temperature.

(Published Patent Publications 1985-500690 and 5006
91. L, E.

Gnse l'ni kov, Yu, P, Po
1yakov, N.S., Nametk in, D.
ok l.

Akad, Nauk, 5SSR, 253, I 13
3 (1980)) (2) 1.2-Bis(chlorosilyl)ethane is allowed to interact with potassium and/or sodium at a temperature of 200<0>C. (L 1.Tver
dokhlebova, O, I, 5utkevich,
I., A., Ronova, Yu, P., Pol.
yakov, L, Ye, Guse l' nik.

V, S, A, Pavlova, Vysokom
ol, 5 oed in, Ser, A, 30
．． 1070 (+988)).

However, method (1) is said to be able to obtain polymers with a molecular weight of up to 140,000, but because it is a gas phase reaction, it requires the use of special equipment, and because it uses alkali metal vapor. This poses a practical problem in that it is extremely dangerous.

In addition, method (2) requires a high temperature of 200°C;
The molecular weight of the resulting clear product (Badisilene-ethylene) is:
This method has a problem in that the maximum number is about 24,000.

[Problem of invention]

The present invention provides an industrially advantageous manufacturing method for vine poly(disilene-ethylene) that avoids the above-mentioned problems, and a poly(disilene-ethylene) having a molecular weight of 1,150,000 or more obtained thereby. Its task is to provide.

[Means for Solving the Problems] As a result of intensive research to solve the above-mentioned problem a, the present inventors have discovered that 1-halosily-2-halosilylethanes are reacted with an alkali metal using a diluent. It was discovered that poly(disilene-ethylene)s could be obtained under mild conditions by doing so, and the present invention was achieved.

According to the present invention, in 3, R″, R″, R1, and R″′ represent an alkyl group that may have a substituent, and X represents chlorine, bromine, or iodine. Provided is a method for producing poly(disilene-ethylene) by polycondensing silyl-2-silylethanes with an alkali metal using a diluent, and the molecule *rs obtained by this method.
The main chain of o, ooo or more is represented by the general formula % (in the formula, n represents an integer), and the substituent on silicon in each main chain repeating unit has a substituent. Poly(disilene-ethylene)s are provided which are optionally alkyl groups.

The alkyl group preferably has 1 to 8 carbon atoms, but the number of carbon atoms is not particularly limited. Furthermore, the alkyl group may have an inert substituent such as an alkoxy group.

In the production method of the present invention, l-
Various silyl-2-silylethanes are used, and the silyl group moiety is 1,2-bis(chlorodimethylsilyl)ethane, to give an example of these 1-silyl-2-silylethanes of one hagelon. , 1,2-bis(bromodimethylsilyl)ethane, 1,2-bis(iododimethylsilyl)ethane, 1,2-bis(chlorodimethylsilyl)ethane, I-(chlorodimethylsilyl)-2-(chloromethyl Examples include ethylsilyl)ethane and 1,2-bis(chloromethylethylsilyl)ethane.

In the production method of the present invention, examples of the alkali metals used include lithium, sodium, potassium, etc., and these can be used alone, as a mixture, or as an alloy.

It is preferable that it be in a dispersed or liquid form, but depending on the reaction conditions, it can also be used as a lump.

The molar ratio of the alkali metal and 1,2-bis(silyl)ethanes is preferably 2:l, but can be arbitrarily selected within the range of IO:I to 2:l.

The diluent used in the production method of the present invention may be any diluent that does not react with halosilanes and alkali metals. To illustrate this, hexane,
Examples include benzene, toluene, xylene, and ethylbenzene.

The manufacturing method of the present invention can be carried out at any temperature above room temperature. When a bulk alkali metal is used and the reaction is carried out at a temperature close to room temperature, it is desirable to activate the surface of the alkali metal by ultrasonic irradiation or the like.

By the production method of the present invention, poly(tetramethyldisilene-ethylene), poly(tetraethyldisilene-ethylene), poly(1,2-dimethyl-1,2-diethyldisilene-ethylene), poly(1,1 ,2-1-dumethyl-2
-ethyldisilene-ethylene), etc. In the present invention, polycondensates with various molecular weights can be produced, but among them, those with a molecular weight of +50,000 or more are new substances.

The produced polymer can be easily separated from the reaction mixture by extraction with a heated solvent after hydrolysis of the reaction solution.

[Effect of the invention] By the method of 2fm Akira, poly(disilene-ethylene) having alternating ethylene moieties and 5i-5i bonds can be easily produced under mild conditions, and it is also possible to produce poly(disilene-ethylene)s having alternating ethylene moieties and 5i-5i bonds, and it is also possible to produce poly(disilene-ethylene)s having alternating ethylene moieties and 5i-5i bonds. A polymer having a molecular weight exceeding 150,000 is provided, and its industrial significance is extremely large.

[Example 1] Next, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 1,2-bis(chlorodimethylsilyl)ethane 5mmo
1.06 g of 40% sodium dispersion (light oil) heated to 80°C in toluene (51112) solution
of toluene (lomQ) chiller, and then add 12
The mixture was heated at 80° C. for an hour. After cooling, first a mixture of acetic acid and ethanol (1:I) I- was added, and then water 10- was added.

After extraction with boiling benzene (5-) three times and drying the solvent,
Ethanol (5dX3) and cold benzene (10dX3)
0.19 g of colorless powder was obtained.

The IR spectrum (KBr disk) of the PCI is 2940 (S), 2860 (S), +240 (S),
1132 (s), +056 (m), 832 (S), 7
70(s), 720(m), 695(S), 608(
s) cm-', and °HNM at 60 °C
The R spectrum (C,H,) showed signals at 0.79 (s, 4H) and 0.24 (S, 12H) pl) m.

In addition, the intrinsic viscosity [η] at 60.0°C in benzene is 1.
746Q/g, and the intrinsic viscosity [η] in toluene at 70.0°C is 1.66 dn/g, which is based on the literature (Vy
sokomol.

5oedin, , Ser, A, 30.1070 (19
The viscosity average molecular weight was calculated from the relational expression between viscosity and molecular weight described in 88)), and was found to be Rv=192,000.

Comparative Example 1 The reaction and post-treatment were performed in the same manner as in Example 1 except that toluene was not used, and as a result, 0.12 g of polymer was obtained. The intrinsic viscosity [η] of this product in toluene at 70.0°C is 0.
．． 64djl/g, and the viscosity average molecule IIC'Mv=
It was calculated as 36,000.

Comparative Example 2 The same procedure as in Comparative Example 1 was carried out except that the reaction temperature was 200°C, and as a result, 0.21 g of polymer was obtained.

The intrinsic viscosity [η] of this product in toluene at 70.0° C. was 0.57 dn/g, which was calculated to be 30,000.

Viscosity average molecular weight Mv・

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R^1, R^2, R^3, R^4 are alkyl groups that may have substituents. (X represents a chlorine, bromine or iodine atom) is polycondensed with an alkali metal using a diluent. There are chemical formulas, tables, etc. ▼ (In the formula, n represents an integer of 3 or more) Poly(disylene-ethylene), where the substituent on the silicon in each main chain repeating unit is an alkyl group. Production method. (2) The main chain is represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (in the formula, n represents an integer), and the substituents on the silicon in each main chain repeating unit have substituents. An optional alkyl group with a molecular weight of 15
0,000 or more poly(disylene-ethylene).