JPH03287605A - Production of polymer - Google Patents

Abstract

PURPOSE:To produce a polymer while facilitating the control of the polymerization rate, the molecular weight of the polymer, etc., by polymerizing a cationically polymerizable vinyl monomer in the presence of a thioether or a thioamide by using an initiator system comprising an organic compound having a specified functional group and a Lewis acid. CONSTITUTION:An initiator system comprising an organic compound having a functional group of the formula (wherein R<1> is H, alkyl or aryl; R<2> is alkyl or aryl; and X is halogen, alkoxy or acyloxy), e.g. 2-chloro-2-phenylpropane, and a Lewis acid is prepared. A cationically polymerizable vinyl monomer (e.g. isobutylene) is polymerized in the presence of a sulfur compound selected between a thioether and a thioamide (e.g. dimethyl thioether) by using this initiator system. In this way, a polymer having a narrow mol.wt. distribution and a controlled mol.wt. can be produced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a polymer by improved cationic polymerization of a cationically polymerizable vinyl monomer, and more specifically, a method for controlling the polymerization reaction rate in a cationic polymerization method. This invention relates to a method for producing polymers, block copolymers, terminally functional polymers, or macromonomers whose molecular weight distribution is narrow and whose molecular weight and structure are arbitrarily controlled from low molecular weight to high molecular weight. It is something.

<Prior art> Generally, when a Lewis acid is used to perform cationic polymerization of a cationically polymerizable vinyl monomer, chain transfer reactions and termination reactions easily occur because carbenillam ions, which are propagating species, are unstable. However, it has been difficult to arbitrarily control the molecular weight and obtain a polymer with a narrow molecular weight distribution, and furthermore, it has been difficult to obtain a block copolymer.

From the viewpoint of controlling the molecular weight of the polymer, conventionally, when performing cationic polymerization by combining a proton-donating compound such as a high alcohol with a Lewis acid, compounds such as amides, esters, and pyridines were allowed to be present in the polymerization system. It has been shown that higher molecular weight polymers can be obtained by this method. However, it is difficult to control the molecular weight and obtain a polymer with a narrow molecular weight distribution, and furthermore, since the polymerization reaction ends within several tens of seconds, it is practically difficult to sufficiently remove the heat of polymerization.

In addition, an attempt to synthesize a block polymer was made using tJs3994.
993 and US 4,276.394, these methods produce not only block copolymers but also respective homopolymers in non-negligible amounts, requiring fractionation operations. Moreover, the polymerization method is also complicated.

Since living polymerization does not involve transfer or termination reactions, it is easy to control the molecular weight, making it possible to synthesize block copolymers, giving polymers with a narrow molecular weight distribution, and controlling the polymerization rate. Therefore, many attempts have been made to find living polymerization systems in cationic polymerization as well.

In recent years, an example of so-called living cationic polymerization has been reported, which suppresses the isomerization, chain transfer reaction, and termination reaction of the growing carbenilam ion in cationic polymerization.

For example, Takushita et al. (Macromolecules, 1
7, 265 (1984)) reported that cationic living polymerization was possible by polymerizing vinyl ether using an initiator containing a combination of hydrogen iodide and iodine.

However, polymerization using this initiator is limited to JII 1, which has a large electron-donating alkoxyl group and is highly cationically polymerizable, and the initiator is unstable and difficult to handle. There was a problem.

On the other hand, Xennedy et al. (JP 62-48704, JP 64-62308) used organic carboxylic acids, esters, or ethers as initiators in combination with Lewis acids to polymerize olefin monomers such as isobutylene.
It was shown that cationic living polymerization is possible even in olefin monomers. However, there are many problems with this method for direct industrial use.

Kennedy et al. prefer boron trichloride, which has low polymerization activity, as the Lewis acid. This is thought to be because when the polymerization activity of the Lewis acid is high, various side reactions occur, making it difficult to control the molecular weight of the polymer.In fact, when titanium tetrachloride, which has a high polymerization activity, is used, the molecular weight and Difficult to control speed.

Furthermore, in general, in cationic polymerization, the polymerization rate is greatly influenced by the state of dissociation of ion pairs of growing species, and if a nonpolar solvent such as butane or pentane in which ion pairs do not dissociate is used, the polymerization rate decreases. Therefore, if boron trichloride, which has low polymerization activity, is used, polymerization will not proceed unless a polar solvent such as methyl chloride is used as a solvent.

In the case of Kennedy et al., the polar solvent that gives good polymerization results is a poor solvent for the polyisobutylene produced, so when the molecular weight of the polyisobutylene exceeds 5000, the polymer precipitates in the system and the growth active species Reactivity is extremely reduced. Therefore, in order to obtain a high molecular weight polymer with controlled molecular weight, the polymerization must be carried out at an extremely high polymerization rate in order to complete the polymerization before the polymer precipitates, but this can be done in a short period of time. Accompanied by the generation of large amounts of heat.

Furthermore, it is impossible to obtain a block copolymer by sequentially adding monomers in a poor solvent system because of precipitation of the polymer.

An example of living cationic polymerization carried out in a specific mixed solvent is described in JP-A-63-205304.

However, this method also has the same problems as the method of Kennedy et al., and cannot be said to be a method for easily obtaining a polymer with a controlled molecular weight.

(Problems to be Solved by the Invention) When polymerizing a cationically polymerizable vinyl monomer, the present inventors have developed an arbitrary polymer that can control the molecular weight over a wide range and has a narrow molecular weight distribution. As a result of intensive research to find a method capable of polymerizing at a polymerization rate of It was discovered that by using an initiator system consisting of an organic compound having After completion of the process, a block copolymer can be synthesized by successively adding other vinyl monomers to this polymerization solution.
Based on this knowledge, we have completed the present invention.

(Means for solving problems) According to the present invention, the following 1.2 and 3 are provided.

1. A method of polymerizing at least one cationically polymerizable vinyl monomer using an initiator system consisting of an organic compound having a functional group shown in formula (1) and a Lewis acid, in which the polymerization is carried out using thioethers, thioamides, etc. A method for producing a polymer of vinyl monomers, characterized in that the method is carried out in the presence of a sulfur-containing compound selected from the group consisting of:

1 C-X (1) 2 2, the manufacturing method according to claim 1, wherein the polymer is a block copolymer.

3. After the polymerization of one type of cationically polymerizable vinyl monomer is substantially completed, another type of cationically polymerizable vinyl monomer is subsequently added to complete the polymerization. A method for producing a block copolymer.

As an initiator used in the present invention, an organic compound having a functional group shown in formula (1) (hereinafter referred to as an initiator compound) is a halogen compound such as 2-chloro-2-
Phenylpropane, bis(2-chloro-2-propyl)benzene, tris(2-chloro-2-propyl)benzene, bis(2-chloro-2-propyl)-1-butylhenzene, bis(2-chloro-2-propyl) ) biphenyl,
Bis(2-chloro-2-propyl)phenanthrene, bis(2-chloro-2-propyl)phenylethane, bis(2-chloro-2-propyl)phenylpropane, 2-
Chloro-2,4,4-trimethylpentane, 2,4,4
．． 6-tetramethyl-2,6-dichlorohebutane, 2,
4.6-) riftyl-2,4,6-dolichlorohebutane, 2,4-dimethyl-2,4-dichlorobencune, 2
, 5-dimethyl-2,5-dichlorohexane, 2.5-
Dimethyl-2,5-dichloro-3-hexyne, 2,5.
Examples include 8-trimethyl-2,5,8-trichlorononane, triphenylchloromethane, 2-chloropropane, 2-chlorobutane, t-butyl chloride, 1-chloroethylbenzene, and the like.

In addition, as a compound having an alkoxy-# group, 2-
Methoxy-2-phenylpropane, bis(2methoxy-
2-propyl>benzene, tris(2-methoxy-2-
propyl)benzene, bis(2-methoxy-2-propyl)-1-butylhenzene, bis(2-methoxy-2-
propyl)biphenyl, bis(2-methoxy-2-propyl)phenanthrene, bis(2-methoxy-2-propyl)phenylethane, bis(2-methoxy-2-propyl)phenylpropane, 24.4-)rifthyl-2 −
Methoxypentane, 2,4.4.6-tetramethyl-2
, 6-dimethoxyhebutane, 2,4,6-trimethyl-2,4,6-)dimethoxyhebutane, 24dimethyl-
2,4-zume1xypenkun, 2.5 dimethyl-2,5
-dimethoxyhexane, 25-dimethyl-2,5-dimethoxy-3-hexyne, 2,5.8-trimethyl-2,
Examples include 5,8-trimethoxynonane, t-butyl methyl ether, 5ec-butyl methyl ether, isopropyl methyl ether, and the like.

In addition, as compounds having an acyloxy group, 2-acetoxy-2-phenylpropane, bis(2-acetoxy-2-propyl)benzene, tris(2-acetoxy-2-propyl)
2-propyl>benzene, bis(2-acetoxy-2-
propyl)-1-butylbenzene, bis(2-acetoxy-2-propyl)biphenyl, bis(2-acetoxy-2-propyl)phenanthrene, bis(2-acetoxy-2-propyl)phenylethane, bis(2-acetoxy-2-propyl)- 2-propyl) phenylpropane, 2.4.4-
Trimethyl-2-acetoxypentane, 2.3, 3.6
-tetramethyl-2,6-diacetoxyhebutane, 2,
4.6- Trimethyl-2,4,6-triacetoxyhebutane, 2,4-dimethyl-2,4-diacetoxypenkune, 2,5-dimethyl-2,5-diacetoxyhexane, 2.5- Dimethyl-2,5-diacetoxy-3-hexyne, 2.5.8-trimethyl-2゜5.8-4-diacetoxynonane, triphenylmethyl acetate, t-
Examples include butyl acetate, 5ec-butyl acetate, isopropyl acetate, and the like.

Furthermore, metal halides are used as Lewis acids, such as BCl2, BF3, BF30Etz, TiCj!
4゜5nC1a, 11cls, A I RCl
z, A121° (R is a lower alkyl group having 1 to 5 carbon atoms), 5b (1!7°5bFS, WCl5.Mo
Specific examples include Cj2s% TaCJs.

Further, specific examples of sulfur-containing compounds such as thioethers or thioamides include dimethylthioether, diethylthioether, dipropylthioether, dibutylthioether, ethylmethylthioether, methyloctylthioether, ethylbutylthioether, diallylthioether, Examples of the thioamides include methylphenyl ether, diphenylthioether, dibenzylthioether, trimethylene sulfide, thiophene, and tetrahydrothiophene. Examples of thioamides include acetothioamide and henzothioamide.

Examples of cationically polymerizable vinyl compounds include isobutylene, propylene, 1-butene, 2-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene,
-Methyl-1-pentene, hexene, vinylcyclohexane, styrene, methylstyrene, t-butylstyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, α-methylstyrene, β-methylstyrene, dimethylstyrene, butadiene, isoprene, cyclopenta Examples thereof include diene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, methyl propenyl ether, ethyl propenyl ether, β-pinene, indene, acenaphthylene, and the like.

The organic solvent used in the present invention is not particularly limited as long as it does not adversely affect the collective activity of the initiator, but may include butane,
Aliphatic organic solvents such as pentane, hexane and heptane, aromatic organic solvents such as benzene, toluene and xylene, nitro compounds such as nitromethane and nitroethane, or
Examples include halogenated organic solvents and mixed solvents thereof.

The polymerization temperature is not particularly limited as long as it is -120 to 50°C, and preferably -100 to 20°C.

The polymerization time is not particularly limited, and the polymerization rate can be controlled by the amounts of the initiator compound, Lewis acid, and sulfur-containing compound. Moreover, the molecular weight can be regulated by the ratio of the initiator compound concentration to the vinyl compound concentration.

In addition, when producing a block copolymer, a type of cationically polymerizable vinyl compound, an initiator compound, a Lewis acid, and a sulfur-containing compound are introduced into the polymerization system, and after substantially completing the polymerization, Subsequently, a block copolymer can be produced by adding another type of cationically polymerizable vinyl compound to the system and further polymerizing it.

The mixing ratio of the initiator compound, Lewis acid, sulfur-containing compound, and vinyl monomer is determined by the number of moles of the functional group (hereinafter referred to as the functional group concentration) shown in formula fl), where the Lewis acid serves as the starting point for polymerization of the initiator compound. The molar ratio of the Lewis acid is 1 to 100 times the functional group concentration of the initiator compound, and the sulfur-containing compound is The molar ratio to the group concentration is 0.
01 to 100 times is preferable. Conditions in which the sulfur-containing compound is in excess of the Lewis acid are not preferred because the polymerization will actually stop. Moreover, the polymerization rate can be controlled by the Lewis acid concentration.

(Effects of the Invention) Thus, according to the present invention, when polymerizing a cationically polymerizable vinyl monomer, sulfur By performing polymerization in the coexistence of contained compounds, the polymerization rate can be controlled and the molecular weight distribution is narrower than with conventional techniques.
Polymers with controlled molecular weight and end structure are provided.

Further, according to the method of the present invention, a block copolymer whose molecular weight can be arbitrarily controlled is provided by sequentially polymerizing at least two different cationically polymerizable vinyl monomers. Further, by adding a compound having a functional group that reacts with growing carhenium ions, a functional group can be introduced at the end.

The present invention will be explained in more detail with reference to Examples below. Note that the percentages in Examples and Comparative Examples are based on weight unless otherwise specified.

(Example 1) 0.0% isobutylene was placed in a glass container under a dry nitrogen atmosphere.
56 g (10 mmol), 2-methoxy-2-phenylpropane (CumOMe) 1.5 rig
(10u 111o & )dimethylthioether1.
9■ (30μmol1), methylene chloride 4.0ml, n
-Hexane 4.0mj! was added and cooled to -50°C.

Next, 0.3 M TiCl cooled to -50°C in advance
4 ・Methylene chloride/n-hexane (volume ratio l/1
) solution 1.0 ml (TiCj!.

0.311111 Iol) was added to start polymerization. After a predetermined time, 3.0 ml of methanol was added to stop the polymerization, and the solvent was removed to obtain the desired polymer.

Number average molecular weight (Mn) and Mw/Mn (Mw is weight average molecular weight) were measured using GPC (Tosoh Corporation HLC-
8020). In addition, assuming that all the initiators work effectively and that no chain transfer reaction or termination reaction occurs during polymerization, the theoretical molecular weight (M, W).

calcd,) was calculated using the following formula. In addition, conv,
(%) is the polymerization conversion rate.

Polymerization times and results are shown in Table 1.

As shown in Example 1, with polymerization time, conv.

It can be seen that Mn increases and Mn increases.

(Example 2) Isobutylene (I) was placed in a glass container under a dry nitrogen atmosphere.
B) 0.56g (10wrmo&), 2-methoxy-
2-phenylpropane (CumO) 1.5■ (1
0μm1lol), dimethylthioether 1.9■<3
0 μIlo&), 4 ml methylene chloride, 4 ml fi-hexane. On& was added and cooled to -68°C. Next, 0.3 M Ti (J 4
・Methylene chloride/n-hexane (volume ratio 1/1) solution 1
Tall (TiC, l!a 0.3 mmol) was added to start polymerization.

After 8 hours, 1.2 rm of a 4.4M styrene/methylene chloride/n-hexane (volume ratio 1/1) solution was added to the reaction solution.
l! (5.4 mmol) was added. Styrene addition 1
After 3 hours, methanol 51111 was added to stop the polymerization, and the solvent was removed under reduced pressure to obtain the desired polymer. Table 2 shows the results.

Furthermore, in the molecular weights of the obtained polymers in Table 2, (1) is the molecular weight of the isobutylene homopolymer, and (2) is the molecular weight of the isobutylene homopolymer.

is the molecular weight of the copolymer.

(Example 3) Inoethylene was polymerized under the same conditions as in Example 1, using 30μ11ot' of henzothioamide as the sulfur-containing compound. The results are shown in Table 3.

Claims (1)

[Claims] 1. A method for polymerizing at least one cationically polymerizable vinyl monomer using an initiator system consisting of an organic compound having a functional group represented by formula (1) and a Lewis acid, 1. A method for producing a vinyl monomer polymer, characterized in that step 1 is carried out in the presence of a sulfur-containing compound selected from the group consisting of thioethers and thioamides. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (In formula (1), R^1 is hydrogen, alkyl group, aryl group, R^2 is alkyl group, aryl group, X is halogen, alkoxy 2. The method according to claim 1, wherein the polymer is a block copolymer. 3. After the polymerization of one type of cationically polymerizable vinyl monomer is substantially completed, another type of cationically polymerizable vinyl monomer is subsequently added to complete the polymerization. A method for producing a block copolymer.