JPH0236204A - Production of isobutylene-based polymer having functional terminal - Google Patents

Abstract

PURPOSE:To obtain at low cost the title polymer for, e.g., adhesives by polymerizing a cationically polymerizable monomer including isobutylene in an inert solvent using a catalyst made up of a specific metal halide and an initiator combined with chain transfer agent. CONSTITUTION:The objective polymer can be obtained by polymerizing a cationically polymerizable monomer including isobutylene in an inert solvent (e.g., methylene chloride) using a catalytic system, a combination of (A) a metal halide of formula SnX4 (X is halogen) or formula TiX4 (e.g., titanium tetrachloride) with (B) an initiator combined with chain transfer agent consisting of an aromatic compound having substituent, of the formula [Y is halogen, RCOO (R is monovalent organic group) or RO; R1 is H; R2 is H or (substituted) monovalent hydrocarbon group] [e.g., p-bis (chloromethyl)durene].

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing isobutylene-based polymers having functional ends. More specifically, the present invention provides a method for cationically polymerizing a cationically polymerizable monomer containing isobutylene by reacting it in the presence of a specific initiator/chain transfer agent and a metal halide, thereby producing a polymer having a halogen atom or functionality. The present invention relates to a method for producing a polymer containing a high content of isobutylene-based polymer in which a group is present at the end of the molecule.

BACKGROUND ART AND PROBLEMS Polymers having a functional group such as a hydroxyl group at the end of the molecule can be cured by forming bonds between the polymers using the functional group. Such polymers are called telechelic polymers and are used as adhesives, sealants, coatings, and the like. Typical examples of telechelic polymers include polyethers and polyesters having hydroxyl groups at the molecular ends, and these polymers can be cured using polyisocyanate compounds.

Recently, a terminally functional polymer using polyisobutylene as the main chain has been proposed (US Pat. No. 4,276,394). Polyisobutylene inherently has excellent weather resistance, electrical properties such as electrical insulation and dielectric properties, and gas barrier properties, and therefore, such terminally functional polyisobutylene is expected to be used in a variety of new applications. .

The above-mentioned US Pat. No. 4,276,394 discloses that the terminal-functional isobutylene-based polymer is produced by a method called the Vinifer method, in which isobutylene is cationically polymerized in the presence of an initiator/chain transfer agent and a catalyst. It is also described that various compounds can be used as initiators and chain transfer agents and catalysts in the Vinifer process. However, in reality, the initiator and chain transfer agent is a compound capable of producing a tertiary carbon cation to which an aromatic ring, which is a stable carbon cation, is bonded (hereinafter referred to as a "tertiary carbon cation generating compound"). ), specifically 1
, 4-bis(α-,chloroisopropyl)benzene (hereinafter referred to as rp-DCCJ). The polymerization reaction formula of isobutylene when pDCC is used as an initiator and chain transfer agent is shown below.

CQ C(CH3) 2GC(CH3) 2 CQ+n
CH2C(CH3) 2 Furthermore, according to the method described in the above US patent specification, when a strong Lewis acid is used as a catalyst, a side reaction (cyclization reaction) that produces an indanyl group as shown in the following formula occurs, and the terminal functional In reality, only BcQ3, which is a mild Lewis acid, is used as a catalyst.

C(CH3)2QC(CH3)2-eH2C(CH3)
2) However, it is difficult to obtain tertiary carbon cation-forming compounds used as initiators and chain transfer agents. In particular, it is extremely difficult to obtain a compound as shown in the following formula in which the hydrogen atom on the aromatic ring is replaced with a methyl group or the like in order to avoid the side reactions mentioned above.

Primary to secondary carbon cations to which aromatic rings are attached are considered to be fairly stable carbon cations, although not as much as tertiary carbon cations. Therefore, 1st class to 2nd class
Compounds capable of producing primary carbon cations, especially compounds capable of producing primary carbon cations (e.g. CQ CR2C6H
ACR2CQ, etc.) are inexpensive and easily available. Further, in order to avoid side reactions, compounds capable of producing a carbon cation bonding an aromatic ring in which the hydrogen atom on the aromatic ring is substituted, such as the compound shown by the following formula, are also easily available.

Therefore, it would be very beneficial if a compound capable of producing a primary or secondary carbon cation to which an aromatic ring is bonded could be used as an initiator and chain transfer agent.

However, according to the research of the present inventor, an initiator and chain transfer agent (e.g. Ca
It was found that even when trying to polymerize isobutylene in the presence of Cl2C6HACH2C (LitoB (13), the polymerization reaction did not proceed.

The object of the present invention is to provide primary to secondary aromatic rings to which aromatic rings are bonded.
The object of the present invention is to provide a method for polymerizing isobutylene using a compound capable of producing carbon cations as an initiator and a chain transfer agent.

SUMMARY OF THE INVENTION The present invention provides for the polymerization of cationically polymerizable monomers containing isobutylene in an inert solvent using a catalyst system consisting of a metal halide and an initiator/chain transfer agent to form functional terminals. In producing an isobutylene polymer having
A compound having an aromatic ring as the above-mentioned initiator and chain transfer agent, wherein the following group Y-C-(I) is present on the aromatic ring [Here, Y is a halogen atom, an RCOO- group, or an RO
- represents a group (R is a monovalent organic group). R1 is a hydrogen atom, R
2 represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. ] A compound having as a substituent (hereinafter referred to as "aromatic ring compound") is used, and 5 is used as the metal 10-genide.
nX4 or T1X4 (where X represents a halogen atom.

) is used to produce an isobutylene polymer having a functional end.

In this specification, the cationic polymerizable monomer containing isobutylene is not limited to a monomer consisting only of isobutylene, but is 50% by weight of isobutylene.
(hereinafter simply referred to as "%") means a monomer in which the following is substituted with a cationically polymerizable monomer that can be copolymerized with isobutylene.

Examples of cationically polymerizable monomers that can be copolymerized with isobutylene include olefins having 3 to 12 carbon atoms, conjugated dienes, vinyl ethers, aromatic vinyl compounds, vinylsilanes, allylsilanes, and the like. Among these, olefins having 3 to 12 carbon atoms and conjugated dienes are preferred.

Specific examples of cationic polymerizable monomers that can be copolymerized with the isobutylene include propylene, 1-butene,
2-butene, 2-methyl-1-butene, 3-methyl-1
-Butene, pentene, 4-methyl-1-pentene, hexene, vinylcyclohexane, butadiene, isoprene, cyclopentadiene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, α-methylstyrene, dimethylstyrene, monochlorostyrene, dichlorostyrene , β-pinene, indene,
Vinyltrichlorosilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, divinyldimethylsilane, 1°3-divinyl-1,1,3,3-tetramethyl Disiloxane, trivinylmethylsilane, tetravinylsilane, allyltrichlorosilane, allylmethyldichlorosilane, allyldimethylchlorosilane, allyldimethylmethoxysilane, allyltrimethylsilane, diallyldichlorosilane, diallyldimethoxysilane, diallyldimethylsilane, γ-methacryloyloxypropyl Examples include trimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and the like. Among these, propylene, 1-butene, 2-butene, styrene, butadiene, isoprene, cyclopentadiene, etc. are preferred. These cationic polymerizable monomers that can be copolymerized with isobutylene may be used alone or in combination with isobutylene.

Examples of the aromatic ring compound that is an initiator and chain transfer agent used in the present invention include a halogen atom in which Y is substantially bonded to a primary or secondary carbon atom at the benzyl position, RCOO-
or R- group (where R is a monovalent organic group).

As a specific example of R, a substituted or unsubstituted C hydrocarbon group is preferable, a C1-3 alkyl group is more preferable, and a methyl group is most preferable.

Further, when R2 in general formula (I) is a monovalent hydrocarbon group, C1-10 hydrocarbon group is most likely, and C1
-3 is more preferably an alkyl group, and most preferably a methyl group. The aromatic ring constituting the aromatic ring compound used in the present invention may be formed by a condensation reaction or may be a non-condensed ring.

Specific examples of such aromatic rings include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring,
Biphenyl in which two or more aromatic rings exist, such as pyrene ring, Ph-(CH2')Q-Ph group (ph is a phenyl group, Q
is an integer from 1 to 10), phoph, etc. may of course also be used.

These aromatic rings are usually substituted with 1 to 6, preferably 2 to 5, groups represented by the above general formula (I). Furthermore, on these aromatic rings, linear and/or branched aliphatic hydrocarbon groups having 1 to 20 carbon atoms, hydroxyl groups,
A group having a functional group such as an ether group or a vinyl group, or a halogen atom may be substituted.

Specific examples of the initiator and chain transfer agent include, for example: Compound E Compound G Compound■ Compound J etc., and among these, compound C is preferred.

Among the above compounds A-J, specific examples of preferred compounds are as follows.

(n is the same as above) (n is the same as above) These compounds are components used as initiators and chain transfer agents, and the molecular weight of the obtained polymer can be controlled by the amount used. In the present invention, it is preferable to use the above compound in a proportion of about 0.01 to 20%, preferably about 0.1 to 10%, based on the cationically polymerizable monomer containing isobutylene.

Further, the metal halide used in the present invention is -
It is a compound represented by 5nX4 or TiXz (X is the same as above). Among these, especially 5nCQL and Ti
CQ4 is preferred.

The amount of the metal halide used is preferably about 0.1 to 10 times, and 2 to 1 times, the number of moles of the initiator and chain transfer agent.
About 5 times is more preferable.

In the present invention, a wide variety of conventionally known polymerization solvents can be used as long as they are inert solvents, and specific examples thereof include chloromethane, chloroform, carbon tetrachloride,
Chloroethane, methylene chloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1.1-trichloroethane, 1,1゜2-trichloroethane, 1,1,2.2
Examples include chlorinated hydrocarbon compounds such as -tetrachloroethane and tetrachloroethylene, and nitro compounds such as n-hexane and nitroethane. These may be used alone or in a mixture of two or more.

When carrying out the method of the present invention, a solvent, an initiator/chain transfer agent, a catalyst (metal halide), etc. are charged into one container, and then a monomer is added (a batch method may be used, or the solvent, monomer, A continuous method may be used in which an initiator/chain transfer agent, a catalyst (metal halide), etc. are continuously introduced into a system to react, and then taken out.

In the method of the present invention, the polymerization temperature is 10 to -1
Approximately 309C is preferable, more preferably -20 to -8
The temperature is preferably about 0°C, and the polymerization time is usually 0.5 to 6
It is about 0 minutes, preferably about 1 to 30 minutes. The monomer concentration during polymerization is preferably about 0.1 to 8 mol, more preferably about 0.5 to 5 mol.

In the present invention, the termination of the polymerization reaction of the cationic polymerizable monomer is not particularly limited, and any conventional and commonly used means can be applied. In the present invention, it is particularly preferable to stop the polymerization reaction by adding alcohol such as methanol.

Effects of the Invention In the method of the present invention, the compound capable of producing a primary or secondary carbon cation bonded to an aromatic ring, which is used as an initiator and chain transfer agent, is an inexpensive and easily available compound. , metal halides are also cheaper than BCQ3. Therefore, according to the present invention, an isobutylene polymer can be obtained at a very low cost.

Furthermore, according to the method of the present invention, it is possible to use an initiator and chain transfer agent having an aromatic ring in which the hydrogen atoms on the aromatic ring are substituted, so an isobutylene polymer with high terminal functionality can be easily obtained at low cost. be able to.

According to the method of the present invention, an isobutylene-based polymer having a high content of a functional terminal based on a halogen atom or an ester or alkoxy content and a small molecular weight distribution can be obtained.Examples are listed below. The present invention will be further clarified.

Example 1 A 1Q pressure-resistant glass autoclave was equipped with a stirring blade, a three-way cock, and a vacuum line, and the polymerization container was dried by heating it at 100°C for 1 hour while evacuated with the vacuum line, and after cooling to room temperature, The pressure was returned to normal pressure with nitrogen using a three-way cock.

Then, while nitrogen was flowing from one side of the three-way stopcock, 290 ml of methylene chloride, a polymerization solvent, was dried by calcium hydride treatment using a syringe and placed in an autoclave.
introduced. Furthermore, p-bis(talolomethyl)durene 1
A solution of 50 mmoles of methylene chloride in which 0 mmol was dissolved was added.

Next, a pressure-resistant glass liquefied gas sampling tube with a needle valve containing 40 g of isobutylene dehydrated by passing through a column filled with barium oxide was connected to a three-way cock, and the container body was placed on dry ice at -70°C. - The polymerization container was immersed in an acetone bath and cooled for 1 hour while stirring the inside of the polymerization container. After cooling, the pressure inside the reactor was reduced using a vacuum line, a two-dollar valve was opened, and isobutylene was introduced into the polymerization container from a pressure-resistant glass liquefied gas collection tube. Thereafter, the pressure was returned to normal by flowing nitrogen through one of the three-way cocks, and cooling was continued for 1 hour while stirring to cool the inside of the polymerization vessel to -35°C.

Next, 40 mmol of titanium tetrachloride was added using a syringe through a three-way stopcock to start polymerization, and after 30 minutes, methanol, which had been cooled in advance to below -40°C, was added to stop the polymerization. It was stopped.

After termination of the polymerization, the polymerization container was returned to room temperature, the reaction mixture was taken out into an eggplant-shaped flask, unreacted isobutylene, methylene chloride, and methanol were distilled off, and the remaining polymer was
After dissolving in n-hexane at 0 threshold, the solution was washed with water repeatedly until it became neutral.

Thereafter, this n-hexane solution was concentrated to 80 mf2, and the concentrated solution was poured into IQ acetone to precipitate and separate the polymer.

The polymer thus obtained was again 400 mQ of n
- by dissolving in hexane, drying over anhydrous magnesium sulfate, filtering, and removing n-hexane under reduced pressure.
An isobutylene polymer was obtained.

The yield is calculated from the yield of the obtained polymer, and M
n and Mw/Mn were determined by GPC method, and the terminal structure was determined by
It was determined by measuring and comparing the intensities of proton resonance signals belonging to each structure by H-NMR (300 MHz) method. The results are shown in Table 2 below.

Examples 2 to 6 Polymers were produced and evaluated in the same manner as in Example 1, except that the overall scale was downsized and the types and amounts of the initiator/chain transfer agent and catalyst were changed as shown in Table 1 below. did. The results are shown in Table 2 below.

Examples 7 to 12 The overall scale was reduced by changing the polymerization solvent methylene chloride to 1,1-dichloroethane, and changing the type and amount of the initiator/chain transfer agent and catalyst as shown in Table 3 below. A polymer was produced and evaluated in the same manner as in Example 1, except for the following. The results are shown in Table 4 below.

As is clear from the results in Tables 2 and 4 above, the molecular weight of the polymer of the present invention obtained under the above conditions was set at Mn
It can be seen that the distribution is close to that of CH3 and the distribution is narrow and good, and that the desired CH3-C-CQ group is introduced at a high rate at the molecular terminal of the polymer.

In addition, Ar of the phenyl group, which is the core of the initiator and chain transfer agent,
By further adding a solvent such as nitroethane to this polymerization system, side reactions can be suppressed, and -C(C
It can be seen that a polymer containing a high proportion of H3)2 CQ groups was obtained, and the molecular n distribution of the polymer was sharper.

Furthermore, by controlling the polymerization termination conditions, it is also possible to produce a functionally terminated polymer having an RC-0 group or an RO group at the end, which contains the functional group of the initiator and chain transfer agent as it is at the end of the polymer.

(that's all)

Claims (4)

[Claims] (1) To produce an isobutylene-based polymer having a functional end by polymerizing a cationically polymerizable monomer containing isobutylene in an inert solvent using a catalyst system consisting of a metal halide and an initiator/chain transfer agent. A compound having an aromatic ring as the above-mentioned initiator and chain transfer agent, on which the aromatic ring has the following group ▲ mathematical formula, chemical formula, table, etc. ▼ (I) [Here, Y is a halogen atom or RCOO- group or RO
- represents a group (R is a monovalent organic group). R_1 represents a hydrogen atom, and R_2 represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. ] as a substituent, and SnX_4 or TiX_4 (herein, X represents a halogen atom) as the metal halide, a method for producing an isobutylene polymer having a functional end. . (2) The initiator and chain transfer agent has a general formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, Z represents a lower alkyl group or a halogen atom. Y
is the same as above. ] The method according to claim 1, wherein the compound is a compound represented by: (3) The initiator and chain transfer agent is p-bis(chloromethyl)
durene, p-bis(methoxymethyl)durene and p
-bis(acetoxymethyl)durene. (4) SnCl_4 or TiC as metal halide
2. The method according to claim 1, wherein l_4 is used.