JPH01132609A - Continuous polymerization of liquid copolymer - Google Patents

Abstract

PURPOSE:To obtain a liquid copolymer of a desired viscosity, by continuously copolymerizing a butane/butylene fraction obtained by the thermal cracking of petroleum with isoprene in the presence of a Friedel-Crafts catalyst while controlling the water concentration in the system and the conversion. CONSTITUTION:Butadiene is removed from a 4C fraction formed from the thermal cracking of petroleum to obtain a butane/butylene fraction. This fraction is continuously copolymerized with isoprene in the presence of a Friedel- Crafts catalyst to an isobutylene conversion <=90% while the water concentration in the system is being kept at 50ppm or below. In this way, a butylene/isoprene liquid copolymer of a relatively high-MW and a controlled viscosity can be produced continuously. The obtained liquid copolymer is highly vulcanizable and can be used desirably as a tackifier or softener for resin and rubber or the like.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to the so-called spent butane-butylene fraction, or below, the BB fraction, which is obtained by removing butadiene from the C4 fraction produced by thermal decomposition of petroleum by solvent extraction or the like. The present invention relates to a continuous copolymerization method of a liquid copolymer of (abbreviated as ) and isoprene. Specifically, the present invention relates to a continuous polymerization method for a butylene-isoprene liquid copolymer, which is characterized in that a continuous method is used to control the viscosity of the product, and in particular, the raw material conversion rate and raw material water concentration are controlled.

[Prior Art] Conventionally, a BB fraction containing butylene such as isobutylene and butene, obtained by removing butadiene from a C4 fraction produced by thermal decomposition of petroleum, and styrene or diene are co-coated in the presence of a 7-Riedel-Crauch catalyst. A method for obtaining a liquid copolymer by polymerization is generally known, and for example, a method for producing a BB fraction-diene copolymer is disclosed in JP-A-61-55107.

[Problems to be Solved by the Invention] However, in the examples in JP-A No. 61-55107, a batch reactor is used, and this polymerization method uses relatively high polymers for the following reasons. It is not possible to produce the copolymer nor to control the viscosity of the resulting copolymer. Firstly, water in the reaction solution has the effect of turning the produced copolymer into a low-molecular-weight mineral and reducing its viscosity, but in a batch-type reactor, it is inevitable to avoid water entering the reactor. As a result, it is difficult to remove moisture sufficiently. Secondly, there are two possible methods of supplying the catalyst in the four-part system: adding the catalyst to the raw material liquid before the start of the reaction and adding it at appropriate times during the reaction, but in either case, the catalyst is supplied in batch mode. As long as the formula is adopted, in the former case, most of the catalyst will be deactivated due to moisture and other impurities in the raw material liquid at the initial stage, and in the latter case, it will be difficult to control the temperature stably due to the sudden temperature upper limit. Therefore, a uniform product cannot be obtained. Third, when the reaction is sufficiently completed, that is, when the conversion rate of the reaction raw material is 100% or close to 100%, the copolymer produced due to overreaction of the butenes in the raw material 8B fraction is The inventors' experiments have found that the molecular weight and viscosity are significantly lowered. That is, in continuous copolymerization with isoprene, it is important to control the conversion rate of the raw material, but the method in the publication does not disclose a continuous method, and there is nothing to suggest about controlling the conversion rate.

[Means for Solving the Problems] Therefore, as a result of intensive studies to solve the above problems, the present inventors used a continuous method instead of a batch method, and lowered the raw material moisture concentration to 50 ppm or less. By continuously supplying the BB fraction and isobutylene to the reactor and performing copolymerization while controlling the conversion rate of isobutylene to 90% or less, the 8B fraction and isoprene, which have a relatively high molecular weight and a controlled viscosity, are produced. The present invention was completed by discovering which liquid copolymer can be produced. The continuous method in the present invention is also highly practical from an industrial standpoint.

[Function] In the present invention, the BB fraction is used as a raw material, and its typical composition is as follows: Isobutene 40% by weight or more Butenes 25-50% by weight Other butanes The above BB fraction and isoprene are continuous. The isoprene supply amount is o, oi ~ 0.2 ON/N/hr of raw material solution, preferably 0.01~0.15 β/N/hr of raw material solution! There is ll/hrl'.

As the Friedel-Crafts catalyst, aluminum chloride, titanium tetrachloride, boron trifluoride, etc. can be used.
A solid Friedel-Crafts catalyst, such as aluminum chloride, can be dispersed in polybutene or hydrogenated polybutene and fed to the feed liquor. The supply amount is 0.25 to 2.5 J/raw material liquid Jl/hr,
Preferably, 0.5 to 0.150/J/hr of raw material liquid is appropriate. Outside this range, the yield or molecular weight of the product may decrease.

In the polymerization reaction of the present invention, the butanes coexisting in the BB fraction act as a diluent, so no particular solvent is required, but it is also possible to use a solvent other than butanes that is inert to the reaction. be. In this case, it is appropriate to use saturated hydrocarbons or halides of saturated hydrocarbons. For example, saturated hydrocarbons such as ethane, propane, butane, pentane, hequinane, petroleum ether, and naphtha, or halogenated hydrocarbons such as methyl chloride, methyl chloride dichloride, carbon tetrachloride, ethyl chloride, and di-methylene can be used. .

The polymerization reaction is carried out at -30 to 50°C, preferably -30 to 40°C.
It is. If it is lower than -30°C, the molecular weight and viscosity of the product will become too large, and if it is higher than 50°C, the molecular weight and viscosity of the product will be too small, making it impossible to obtain a liquid copolymer having desirable physical properties.

In the present invention, if the conversion rate of the raw materials is too high, the resulting copolymer will have a low molecular weight and low viscosity, so reaction variables such as catalyst amount, reaction temperature, and LH8V are appropriately selected.
It is important to control the isobutylene conversion rate in the raw material liquid to 90% or less.

Further, the presence of water in the raw material causes a decrease in the molecular weight of the produced copolymer, and in extreme cases copolymerization does not proceed, so the raw material is sufficiently dried to control the water concentration to 50 ppm or less. This is accomplished by thoroughly drying the raw material, measuring and monitoring the moisture concentration at the outlet of the reactor, and feeding the results back to the raw material drying process. The reaction pressure may be sufficient as long as the reaction phase maintains a liquid phase.

The reaction time is liquid hourly space velocity (LH8V), 0.01~
100 hr, preferably 0.1 to 50 hr is appropriate.

The copolymer of the present invention can be obtained by continuously extracting the reaction solution from the reactor, deactivating the catalyst with sodium hydroxide, etc., and removing unreacted components by distillation or the like.
According to the present invention, a liquid copolymer is obtained by copolymerizing butylene and isoprene in 881 minutes, and the obtained copolymer of BB fraction and isoprene has high vulcanizability and imparts tackiness to resins or rubbers. It is useful as an additive for agents, softeners, etc.

[Example] Hereinafter, the present invention will be described in more detail with reference to Examples.

Examples 1 to 5 Raw material B having the composition shown in Table 1 was placed in a 2ρ autoclave equipped with a stirrer and cooled by an external cooling method.
Polymerization was carried out by continuously feeding a mixed solution of fraction B and isoprene and a slurry aluminum chloride catalyst dispersed in polybutene from a separate line. The liquid continuously discharged from the reactor was washed with sodium hydroxide and water to stop the reaction, and after volatilizing unreacted monomers, it was distilled to obtain the desired copolymer.

LH8V was 1.0, and the inside of the autoclave was pressurized to 6 Q/ci so that the raw materials maintained a liquid phase.

The stirring speed is 1. OOOrpm. The reaction temperature, amount of catalyst, isoprene feedstock, and conversion rate of isobutylene are shown in Table 2.

The composition of the raw material Be fraction used is shown in Table 1.

In order to sufficiently dry the raw material liquid, it was passed through a column packed with molecular sieves and then continuously supplied to the reactor.

The viscosity and molecular weight of the copolymer of Be fraction and isoprene produced by the above procedure are also shown in Table 2.

Comparative Examples 1 and 2 In Comparative Example 1, the same amount of isoprene as in Example 3 was supplied, a larger amount of catalyst was supplied, and the isobutylene conversion rate was increased. As is clear from Table 2, both the viscosity and the molecular weight are smaller compared to Example 3. Furthermore, Comparative Example 2 showed a case where the water concentration in the raw material fraction was higher than that in Example 3. In this case, the copolymerization reaction itself did not occur.

Table 1 Raw material 88 fraction composition Branch office Concentration (weight%) Butanes 19.0 Isobutylene 45.5 Butenes 35.1 Others 0.4 (Margin below)

Claims (6)

[Claims] (1) A butane/butylene fraction obtained by removing butadiene from the C_4 fraction produced by thermal decomposition of petroleum and isoprene in the presence of a Friedel-Crafts catalyst while keeping the water concentration in the system at 50 ppm or less. A method for continuously polymerizing a butylene-isoprene liquid copolymer, which comprises continuously copolymerizing so that the conversion rate of isobutylene is 90% or less. (2) The polymerization method according to claim 1, wherein the copolymer produced has a viscosity in the range of 500 to 70,000 cSt (100°C). (3) The polymerization method according to claim 1, wherein the polymerization temperature is in the range of -30 to 50°C. (4) Friedel-Crafts catalyst supply amount is 0.25~
The polymerization method according to claim 1, wherein the amount is 2.5 g/l/hr of raw material solution. (5) The polymerization method according to claim 1, wherein the supply amount of isoprene is 0.01 to 0.20 l/l/hr of raw material solution. (6) The polymerization method according to claim 1, wherein the Friedel-Crafts catalyst is aluminum chloride.