JPH0225370B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polymers. Conventionally, the polymerization of trimethylsilylacetylene, a silicon-based acetylene, was carried out using Wcl ₆ as the main catalyst and tetrabutyltin as a co-catalyst (Higashimura, Masuda, et al., p. 208 of the 1957 Society of Polymer Science Annual Meeting Proceedings). However, the obtained polymer contained many insoluble materials in the solvent, and even the dissolved material had a low molecular weight, and its practical value was low. Under these circumstances, the present inventors have arrived at the present invention as a result of intensive studies. That is, the present invention is based on the general formula (In the formula, R is a C ₁ to C ₁₂ linear or branched alkyl group.) TaX ₅ or NbX ₅ (such asゞしX is Cl
Or Br. ) and an organoaluminum compound as a cocatalyst 1
- A method for producing monoalkyldimethylsilylpropyne polymers. TaCl ₅ , NbX ₅ (X is a halogen, _e.g. Cl or Br) used as a polymerization catalyst;
TaBr ₅ , etc., and NbX ₅ as Nbcl ₅ , etc.
Examples include NbBr ₅ , and a mixture of two or more types can also be used. Among these, Tacl ₅ and TaBr ₅ are preferred because they yield polymers with a practical degree of polymerization. The organoaluminum used as a cocatalyst is trialkyl (the number of carbon atoms in the alkyl group is usually 1).
~5) aluminum (trimethylaluminum, triethylaluminum, tri-n- or isopropylaluminum, tri-n- or isobutylaluminum, etc.), mono- or dihalo (Cl, Br, etc.) di- or monoalkylaluminium (alkyl group of trialkylaluminum) Compounds in which one or two chlorine groups are substituted with (eg, monochlorodimethylaluminum, dichloromethylaluminum, monochlorodiethylaluminum, dichloroethylaluminum, etc.) and mixtures of two or more thereof can be mentioned. Among these, triethylaluminum, monochlorodiethylaluminum, and dichloroethylaluminum are preferred from the standpoint of obtaining a polymer with a high polymerization yield and high degree of polymerization. 1-monoalkyl (C ₁ -
₁₂ ) In dimethylsilylpropyne, examples of the C ₁ to ₁₂ straight chain alkyl of R in general formula (1) include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl octyl, nonyl, decyl, and dodecyl groups. . Examples of the branched alkyl group include isobutyl group and tert-butyl group. Examples of the 1-monoalkyldimethylsilylpropyne represented by the general formula (1) include 1-trimethylsilylpropyne, 1-mono-n-propyldimethylsilylpropyne, 1-mono-n-hexyldimethylsilylpropyne, 1-mono-n-hexyldimethylsilylpropyne, Examples include mono-n-decyldimethylsilylpropyne. The 1-monoalkyldimethylsilylpropyne represented by the general formula (1) may be a single monomer or may be a mixture of two or more monomers. During polymerization, the amount of TaX ₅ and/or NbX ₅ used as the main polymerization catalyst is 1-monoalkyl (C ₁ to ₁₂ ).
The amount is usually 0.01 to 20 mol%, preferably 0.5 to 5 mol%, based on dimethylsilylpropyne. If the amount used is less than 0.01 mol%, polymerization will not start or the polymerization yield will be extremely low, and if it exceeds 20 mol%, the molecular weight of the polymer will become low. The amount of the organoaluminum compound used as a cocatalyst is the same as that of the polymerization catalyst TaX ₅ and/or NbX ₅ .
The molar ratio is usually 1:1 to 0.01:1, preferably 1:1 to 0.1:1. When the cocatalyst has a molar ratio of less than 0.01, the molecular weight of the obtained polymer is high when the monomer of general formula (1) has 1 to 3 carbon atoms in the alkyl group, but A polymer with _a high molecular weight ( _C5-12 ) cannot be obtained, and when it exceeds 1, the molecular weight of the obtained polymer becomes low. Furthermore, by adjusting the ratio of the main catalyst to the cocatalyst within the above range, polymers with various molecular weights can be produced. Polymerization of 1-monoalkyl _{( C1-12} ) dimethylsilylpropyne using a main polymerization catalyst and a cocatalyst is usually carried out in the presence of a solvent. As a solvent, aromatic hydrocarbons (benzene, toluene, xylene, etc.); halogenated hydrocarbons (carbon tetrachloride, 1,2-
dichloroethane, etc.); alicyclic hydrocarbons (cyclohexane, etc.), and mixtures of two or more of these. Monomer concentration is typically relative to the solvent
The amount is 0.1 to 5 mol/, preferably 1 to 2 mol/. Although there is no particular restriction on the order in which the monomer, polymerization catalyst, and cocatalyst are added, the monomer is usually added after a predetermined amount of the polymerization catalyst and cocatalyst are added to the solvent and brought to a predetermined polymerization temperature. Conversely, the catalyst and cocatalyst may be added after the monomer solution is brought to a predetermined temperature. The polymerization temperature can be changed arbitrarily from room temperature to the boiling point of the solvent exceeding 100°C, but preferably 50°C.
~100℃. The polymerization time varies depending on the polymerization temperature, but if the polymerization temperature is 50 to 100°C, it is several hours to several tens of hours. Purification of the polymer polymerized as described above is as follows:
This can be carried out by a conventional method such as adding a polymer solution to a large amount of food solvent (for example, methanol) to precipitate the polymer, and then drying it separately. The obtained monoalkyl (C ₁ - ₁₂ ) dimethylsilylpropyne polymer has a high molecular weight and an intrinsic viscosity of usually 0.5 (dl/g) or more. The polymer is soluble in aromatic hydrocarbons (benzene, toluene, xylene, etc.); halogenated hydrocarbons (carbon tetrachloride, chloroform, etc.); alicyclic hydrocarbons (cyclohexane, etc.), and mixtures of two or more of these. . The present invention is capable of polymerizing monoalkyl ( _C1 - _C12 ) dimethylsilylpropyne in high yield regardless of whether the alkyl group is short or long, and the molecular weight of the obtained polymer is sufficiently large. We provide a manufacturing method that has this effect. Furthermore, by changing the ratio of the main catalyst to the cocatalyst, practical polymers having various molecular weights depending on the intended use can be obtained. The resulting polymers are expected to be applied as various functional polymer materials including electronic materials. The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. Examples 1 to 8 20 myctyl of polymerization catalyst was added to polymerization solvent 1 shown in Table 1 under a dry nitrogen atmosphere, and a cocatalyst was added in a molar ratio to the polymerization catalyst shown in Table 1. After this reaction solution was heated to 80°C, it contained the alkyl groups shown in Table 1. 1.0 mol of 1-monoalkyldimethylsilylpropyne monomer was added.
The reaction solution becomes viscous after a while. 80 as is
The polymerization reaction was carried out at ℃ for 24 hours. The resulting polymer was precipitated by pouring the polymerization solution into a large amount of methanol, and then dried separately. The yield (%) of the polymer was calculated based on the amount of monomer charged. The intrinsic viscosity ([η]) of the polymer was measured and calculated in toluene at 30°C according to a conventional method. These results are also listed in Table 1.

[Table] Examples 9 to 15 Copolymerization studies of two types of 1-monoalkyldimethylsilylpropyne monomers listed in Table 2 were conducted. In this case (in Examples 9 to 15), toluene was used as the solvent, Tacl ₅ was used as the polymerization catalyst, and 20 ml of Al(C ₂ H ₅ ) ₃ was used as the co-catalyst. Monomer concentration, polymerization temperature, and time are as in Examples 1 to 8.
The same conditions were used. The results are also listed in Table 2.

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Claims (1)

[Claims] 1. General formula (In the formula, R is a C ₁ to C ₁₂ linear or branched alkyl group.) TaX ₅ and/or NbX are used as the main polymerization catalyst when polymerizing 1-monoalkyldimethylsilylpropyne represented by _Five
(X is halogen) and an organoaluminum compound as a cocatalyst. 2. The production method according to claim 1, wherein the organoaluminum compound is a compound selected from the group consisting of (i) trialkylaluminum and (ii) mono-, dihalodi- or mono-alkylaluminum. 3 The molar ratio of polymerization main catalyst and cocatalyst is 1:1 or more.
10.01 The manufacturing method according to claim 1 or 2.