JP2000344814A - Cationic polymerization process and catalyst used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain a polymer which is free of clouding owing to the precipitation of a catalyst by polymerizing a cationic polymerizable monomer in the presence of a catalyst composed of an arylboron fluoride compound and a protonic acid or its derivative. SOLUTION: As the protonic acid or its derivative, it is preferred to use a compound that has at least one proton-generating group and at least one aromatic hydrocarbon residue and also has a structure wherein the aromatic hydrocarbon residue is substituted with at least two halogen atoms. The arylboron fluoride compound is favorably used such that the value of the cationic polymerizable monomer/the arylboron fluoride compound (molar ratio) is 10 to 10,000. The protonic acid or its derivative is used in such a may that a theoretical formation ratio (molar ratio) of the cationic polymerizable monomer/the adduct of the cationic polymerizable monomer and the protonic acid or its derivative is 2 to 10,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an industrially useful cationic polymerization method and a cationic polymerization catalyst used therein.

[0002]

2. Description of the Related Art Conventionally, as a cationic polymerization method using a catalyst, for example, Polym. Prepr. 28
(1), 176 (1987) and 28 (2), 224
(1987), Makromol. Chem. , Mac
romol. Symp. 13/14, 433-441
(1988) discloses the polymerization of styrene using acetate or haloacetate / BCl3.
l. Chem. , Rapid Commun. 11,5
25-533 (1990), Macromolecul
es 24, 2122-2123 (1991), Mac
romolecules 24, 3988-3992 (1
991), Makromol. Chem. , Macro
mol. Symp. 47, 67-81 (1991), M
acromolecules 25, 2587-2591
(1992) describes the polymerization of vinyl ethers using acetate or haloacetate / zinc salts.
moleculars 25, 6400-6406 (199
2) discloses polymerization of vinyl ethers using a benzoic acid derivative. However, in any of these polymerization methods, depending on the use, the reaction solution may become cloudy after the reaction is stopped, or the resin obtained by depositing the catalyst after removing the solvent may become cloudy.

Further, J. A. Polym. Sci. A: P
Olym Chem 35: 581-585 (199
6) reports a method using an immobilized carboxylic acid, that is, a cation exchange resin. However, according to this method, since the carboxylic acid used is a crosslinked product and the reaction proceeds in a heterogeneous system, the reaction rate is relatively slow, which is industrially disadvantageous.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an efficient cationic polymerization method and a cationic polymerization method used in any application without causing catalyst precipitation and clouding of the polymer. To provide a catalyst for use.

[0005]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems. As a result, in cationic polymerization, first, a protonic acid or a derivative thereof is added to a cationically polymerizable monomer to form an adduct, and the adduct is activated with an arylboron fluoride compound to efficiently perform the adduct. It has been found that a polymer can be produced and that the catalyst does not precipitate and the polymer does not become cloudy, and the present invention has been completed.

That is, the cationic polymerization method according to the present invention is a cationic polymerization method in which a cationically polymerizable monomer is polymerized in the presence of a catalyst, wherein the catalyst is a fluoroaryl boron compound, a protonic acid or And its derivatives. The cationic polymerization catalyst according to the present invention comprises a fluoroaryl boron compound and a protonic acid or a derivative thereof.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail. The cationic polymerization method of the present invention,
A cationic polymerization method for polymerizing a cationically polymerizable monomer in the presence of a catalyst, wherein a fluoroaryl boron compound and a protonic acid or a derivative thereof are used as the catalyst. First, a proton acid or a derivative thereof is added to a cationically polymerizable monomer to form an adduct, and an active species can be easily generated by allowing the fluoroaryl boron compound to act on the adduct. The cationic polymerizable monomer can be efficiently polymerized by the active species.

In the present invention, the fluorinated arylboron compound is a boron compound having at least one aromatic ring substituted by at least one fluorine. Specifically, for example, trispentafluorophenylborane, pentafluorophenyldifluoroborane, bispentafluorophenylfluoroborane and the like can be mentioned.

The above-mentioned protonic acid or its derivative is not particularly restricted but includes, for example, acetic acid, fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, dibromoacetic acid, tribromoacetic acid. , Iodoacetic acid, diiodoacetic acid, triiodoacetic acid, methanesulfonic acid, hypochlorous acid,
Alternatively, derivatives of these exemplified compounds, hydrogen chloride,
Hydrogen bromide, hydrogen iodide and the like.

In the present invention, the protic acid or a derivative thereof may be the above-mentioned compound, but in particular, at least one proton-generating group and at least one
Compounds having two aromatic hydrocarbon residues and having a structure in which the aromatic hydrocarbon residues are substituted with at least two halogen atoms are preferred. The adduct formed by the addition reaction between the compound having such a structure and the cationically polymerizable monomer is easily activated by the fluorinated arylboron compound, so that the cationically polymerizable monomer is efficiently polymerized. be able to.

[0011] Examples of the proton generating group in the compound suitable as the protonic acid or a derivative thereof include a hydroxyl group, a mercapto group, a carboxyl group, a phosphoric acid group and a phosphorous acid group. When two or more of these functional groups are present, they may be the same functional group or different functional groups, but are preferably the same functional groups in terms of reactivity.

The aromatic hydrocarbon residue in the compound suitable as the protonic acid or a derivative thereof may be, for example, a typical phenyl group.
When there are two or more aromatic hydrocarbon residues, the respective aromatic rings may or may not be condensed with each other. Examples of the former include naphthyl and anthracenyl groups, and examples of the latter include biphenyl and terphenyl.

Examples of the halogen atom in the compound suitable as the protonic acid or a derivative thereof include fluorine, chlorine, bromine and iodine, and other electron-withdrawing groups such as a cyano group and a nitro group. It may be substituted. Two or more electron withdrawing groups selected from these may be the same functional group or different functional groups.

Specific examples of the substance suitable as the above-mentioned protonic acid or its derivative are shown below, but are not limited thereto. For example, substituted products such as difluorophenol, dichlorophenol, dibromophenol, and diiodophenol; substituted products such as difluorothiophenol, dichlorothiophenol, dibromothiophenol, and diiodothiophenol; difluorobenzoic acid, dichlorobenzoic acid, and dibromobenzoic acid Substitutes such as acid and diiodobenzoate; Substitutes such as difluorophenyl phosphate, dichlorophenyl phosphate, dibromophenyl phosphate and diiodophenyl phosphate; difluorophenyl phosphite and dichlorophenyl phosphite And substituted products such as dibromophenyl phosphite and diiodophenyl phosphite; and the like.

Further, for example, trifluorophenol,
Substitutes such as trichlorophenol, tribromophenol, and triiodophenol; substitutions such as trifluorothiophenol, trichlorothiophenol, tribromothiophenol, and triiodothiophenol; trifluorobenzoic acid, trichlorobenzoic acid, and tribromobenzoic acid , Triiodobenzoic acid, etc .; trifluorophenyl phosphate, trichlorophenyl phosphate, tribromophenyl phosphate, triiodophenyl phosphate, etc .; trifluorophenyl phosphite, trichlorophenyl Substitutes such as phosphite, tribromophenyl phosphite, triiodophenyl phosphite; and the like.

Further, for example, a substituent such as tetrafluorophenol, tetrachlorophenol, tetrabromophenol, tetraiodophenol and the like; a substituent such as tetrafluorothiophenol, tetrachlorothiophenol, tetrabromothiophenol and tetraiodothiophenol A substituent such as tetrafluorobenzoic acid, tetrachlorobenzoic acid, tetrabromobenzoic acid, or tetraiodobenzoic acid; tetrafluorophenyl phosphate;
Substitutes such as tetrachlorophenyl phosphate, tetrabromophenyl phosphate, tetraiodophenyl phosphate; tetrafluorophenyl phosphite, tetrachlorophenyl phosphite, tetrabromophenyl phosphite, tetraiodophenyl Substitutes such as phosphite; and the like.

Further, for example, substituted products such as pentafluorophenol, pentachlorophenol, pentabromophenol and pentaiodophenol; substituted products such as pentafluorothiophenol, pentachlorothiophenol, pentabromothiophenol and pentaiodothiophenol A substituent such as pentafluorobenzoic acid, pentachlorobenzoic acid, pentabromobenzoic acid, pentaiodobenzoic acid; pentafluorophenyl phosphate;
Substitutes such as pentachlorophenyl phosphate, pentabromophenyl phosphate, pentaiodophenyl phosphate; pentafluorophenyl phosphite, pentachlorophenyl phosphite, pentabromophenyl phosphite, pentaiodophenyl Substitutes such as phosphite; and the like. One of the above-described initiators may be used alone, or two or more of them may be used in combination.

In the present invention, examples of the cationically polymerizable monomer include vinyl ethers, styrenes, epoxides, N-vinyl carbazole and the like. Specifically, examples of the vinyl ethers include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, n-hexyl, t-amyl, cyclohexyl, and n
Aliphatic hydrocarbon residues such as octyl, n-decyl, n-dodecyl, lauryl, stearyl (octadecyl), and 2-ethylhexyl, or oxygen-containing aliphatic groups such as 2-butoxyethyl and methyl-trioxyethylene; Examples thereof include vinyl ethers having a hydrocarbon residue, an alkyl halide residue such as a 2-chloroethyl group, or an aromatic hydrocarbon residue such as phenyl and benzyl. Examples of the styrenes include styrene, p-methylstyrene, chloromethylstyrene, p-methoxystyrene, p-butoxystyrene, and α-methylstyrene. Examples of the epoxides include ethylene oxide, propylene oxide, butylene oxide, oxetane, epoxybutene, cyclohexene oxide, styrene oxide, ethylene sulfide, propylene sulfide, and thiethane. These cationically polymerizable monomers may be used as a mixture of two or more kinds within a range that does not cause a chain transfer reaction or a termination reaction of polymerization, or when the active terminal is stable, one kind of polymerization is completed. At this point, a different kind of monomer may be appropriately added to further extend the main chain.

In the present invention, the protonic acid or its derivative may be directly polymerized together with the catalyst in the whole amount of the cationically polymerizable monomer used for the polymerization,
Alternatively, it is also possible to activate a part of the total amount of the cationically polymerizable monomer used in the polymerization with a catalyst to start the polymerization reaction, and then to polymerize by adding the remaining cationically polymerizable monomer. it can. In the latter case, the cationically polymerizable monomer used first and the remaining cationically polymerizable monomer to be added after the polymerization is started may be of the same type or different types of monomers. Is also good.

In the present invention, the amount of the fluorinated arylboron compound is not particularly limited, but preferably, the amount of the cationically polymerizable monomer / the amount of the fluorinated arylboron compound (molar ratio) = 10 to 10,000. , Preferably 100
It is preferably from 1,000 to 1,000. If the amount of cationically polymerizable monomer / the amount of the fluorinated arylboron compound (molar ratio) is less than 10, the polymerization rate becomes too fast to control the reaction, and if it is more than 10,000, the reaction rate becomes slow. is there.

In the present invention, the amount of the protonic acid or its derivative used is not particularly limited, but the total amount of the cationically polymerizable monomer / addition of the cationically polymerizable monomer with the protonic acid or its derivative Theoretical amount of body formation (molar ratio)
= 2 to 10000, preferably 2 to 5000. If the total amount of the cationic polymerizable monomer / theoretical amount of the adduct (molar ratio) is smaller than 2, the polymer may not be formed,
If it is larger than 0, the viscosity of the system may be too large, which is not preferable.

In the present invention, a solvent can be used to remove the heat of reaction. The solvent that can be used is not particularly limited as long as it is inert to the reaction and can dissolve the produced polymer. Examples thereof include aliphatic hydrocarbon solvents such as n-hexane and cyclohexane, and benzene. , Toluene, xylene, mesitylene, etc., aromatic hydrocarbon solvents, acetone, methyl ethyl ketone, cyclohexanone, etc. ketone solvents, dimethyl ether, diethyl ether, diphenyl ether, dibenzyl ether, etc. ether solvents, methylene chloride, chloroform, etc. halogenation A polar aprotic solvent such as an alkyl solvent and acetonitrile can be used. These are 1
They may be used alone or in combination of two or more. The amount of the solvent is not particularly limited as long as the polymerization rate is not significantly reduced, but is preferably 0.01 to 50 times the weight of the cationically polymerizable monomer.
More preferably, it is 0.5 to 10 times.

In the present invention, the polymerization reaction temperature is preferably 100 ° C. or lower in consideration of the dissociation and decomposition of the adduct formed as an intermediate, although it depends on the kind of the cationically polymerizable monomer. The reaction time is not particularly limited and may be appropriately set according to the progress of the reaction. In the present invention, any of a batch format, a semi-batch format, and a continuous format may be adopted as a reaction format. When the batch format and the semi-batch format are employed, the method of supplying the raw materials is not particularly limited. Specifically, for example, a part of the cationically polymerizable monomer, a protonic acid or a derivative thereof,
If necessary, a solvent is first charged, and the atmosphere is replaced with nitrogen that has been sufficiently dried. Thereafter, the temperature is maintained at a predetermined temperature. To Next, the remaining cationically polymerizable monomers are collectively or divided,
Alternatively, it is introduced into the reactor at a constant rate. Thereafter, the polymerization starts with heat generation, and as the polymerization proceeds to a large extent, the calorific value decreases and no temperature rise is observed. Therefore, in order to complete the polymerization, it is preferable to leave the mixture as it is for a while. At this time, if necessary, the mixture may be gradually heated to completely consume the unreacted monomer. After termination of the reaction, for example, amines such as triethylamine, alkalis such as an aqueous KOH solution, alcohols such as methanol or ethanol, and the like can be added to stop the polymerization.

The catalyst for cationic polymerization of the present invention comprises the above-mentioned fluorinated aryl boron compound and the above-mentioned protonic acid or its derivative. The mechanism of action as a catalyst is not particularly clear, but the protonic acid or its derivative first adds to the cationically polymerizable monomer to form an adduct, and the fluoroaryl boron compound activates the adduct. Thus, it is presumed that it functions as a catalyst and can effectively polymerize the cationically polymerizable monomer.

[0025]

EXAMPLES Examples and comparative examples according to the present invention will be described below, but the present invention is not limited by these examples. Example 1 5.0 g of isobutyl vinyl ether and 0.01 g of dichloroacetic acid were charged and mixed in a 100 ml eggplant-shaped flask sufficiently purged with dry nitrogen to completely dissolve dichloroacetic acid, and then 45 g of toluene was added. ,
The system was cooled to 0 ° C. while purging with nitrogen. Then, a trispentafluorophenylborane / toluene solution (0.0051 g / 0.5 g) was added to the eggplant flask. When stirring was continued with a magnetic stirrer, the exotherm started several minutes after the addition, and after reacting for 30 minutes,
The polymerization was stopped by adding triethylamine. After completion of the reaction, the reaction solution was collected and subjected to gas chromatography (column: SPB-1 manufactured by Spelco, 30 mx 0.53 mm x 1.5
When the unreacted monomer was analyzed at μm), the monomer conversion was 100%. In addition, gel permeation chromatography (column: Tosoh, Shode
x: KF-805L, KF-80 / polystyrene conversion)
The peak molecular weight and the molecular weight distribution were measured to be 32,000 and 1.18, respectively. Further, when the reaction solution was allowed to stand for one month, the reaction solution was colorless and transparent with no turbidity due to deposition of the catalyst.

Example 2 1 sufficiently substituted with dry nitrogen
In a 00 ml eggplant-shaped flask, 5.17 g of isobutyl vinyl ether and 0.0106 g of pentafluorobenzoic acid are charged and mixed to completely dissolve pentafluorobenzoic acid, and then 45.05 g of toluene (partly left). And cooled to 0 ° C. while purging with nitrogen. Then, 0.0260 g of trispentafluorophenylborane was dissolved in a part of the toluene and added to the eggplant flask. When stirring was continued with a magnetic stirrer, heat generation started several minutes after the addition, and the mixture was allowed to react for 30 minutes. Thereafter, triethylamine was added to terminate the polymerization. After completion of the reaction, the obtained reaction solution was analyzed in the same manner as in Example 1, and the monomer conversion was 10%.
It was 0%. The peak molecular weight and molecular weight distribution are
They were 654,000 and 1.49, respectively. Further, when the reaction solution was allowed to stand for one month, the reaction solution was colorless and transparent with no turbidity due to deposition of the catalyst.

Comparative Example A reaction was conducted in the same manner as in Example 1 except that 0.5 ml of an Et ₂ AlCl / hexane solution was used instead of the trispentafluorophenylborane / toluene solution. About the obtained reaction liquid, Example 1
When the same analysis was performed as in the above, the monomer conversion was 95%
Met. The apex molecular weight and the molecular weight distribution were 28,000 and 2.30, respectively. When this reaction solution was left for several days, precipitation and coloring of the catalyst were observed in the reaction solution,
Thereafter, the turbidity gradually increased.

[0028]

According to the present invention, it is possible to provide a cationic polymerization method and a cationic polymerization catalyst to be used which are efficient, in which the catalyst does not precipitate and the polymer does not become cloudy in any application, and is efficient. Can be.

Claims (4)

[Claims] 1. A cationic polymerization method in which a cationically polymerizable monomer is polymerized in the presence of a catalyst, wherein a fluorinated aryl boron compound and a protonic acid or a derivative thereof are used as the catalyst. Cationic polymerization method. 2. The protonic acid or derivative thereof has at least one proton generating group and at least one aromatic hydrocarbon residue, and the aromatic hydrocarbon residue is substituted with at least two halogen atoms. The cationic polymerization method according to claim 1, which is a compound having a modified structure. 3. A catalyst for cationic polymerization comprising a fluoroaryl boron compound and a protonic acid or a derivative thereof. 4. The protonic acid or derivative thereof has at least one proton generating group and at least one aromatic hydrocarbon residue, and the aromatic hydrocarbon residue is substituted with at least two halogen atoms. The catalyst for cationic polymerization according to claim 3, which is a compound having a modified structure.