Method for producing amidomethylated vinyl aromatic polymers

Abstract

The present invention relates to a process for preparing amidomethylated vinyl aromatic polymers.

Description

[Technical Field]

[0001] The present invention relates to a method for preparing amidomethylated vinyl aromatic polymers. [Background technology]

[0002] The preparation of amidomethylated vinylaromatic polymers has been known for a long time. Patent Document 1 discloses that crosslinked styrene bead polymers can be condensed with N-hydroxymethylphthalimide in the presence of a swelling agent and a Friedel-Crafts catalyst. The drawbacks of this method are that N-hydroxymethylphthalimide must first be prepared from phthalimide, water must be distilled off during the reaction, hydrohalic acid must be added, and the yield of amidomethylated vinylaromatic polymers is insufficient.

[0003] A further method for preparing amidomethylated vinylaromatic polymers is known from Patent Document 2, in which phthalimide, paraformaldehyde, and sulfuric acid are reacted in one step in the presence of 1,2-dichloroethane as a swelling agent and a vinylaromatic bead polymer. Here, a different swelling agent is described as an alternative to 1,2-dichloroethane. A disadvantage of this method as well is the insufficient yield of amidomethylated vinylaromatic polymer.

[0004] A further one-step method for preparing amidomethylated vinyl aromatic polymers is known from Patent Document 3, in which the swelling agent used is 1,3-dichloropropane. This swelling agent can only be industrially separated from the product by complex methods, and therefore its use is relatively expensive. Moreover, 1,3-dichloropropane is suspected of being carcinogenic, and therefore is not a usable swelling agent.

[0005] Patent Document 4 discloses an amidomethylation method in the presence of benzotrifluoride, which is found to produce hydrofluoric acid, which causes corrosion of the reactor, and therefore this method is also unusable.

[0006] Patent document 5 discloses a method in which amidomethylation is carried out in the presence of bromoalkyl derivatives. However, these compounds are currently being considered to what extent they also have toxic properties that may limit their use. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] German Patent Application Publication No. A2211134 [Patent Document 2] U.S. Patent No. A4232125 [Patent Document 3] European Patent Application Publication No. A3012272 [Patent Document 4] European Patent No. B3478727 [Patent Document 5] European Patent No. B3581595 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, there remains a need for a process that overcomes the shortcomings of the prior art and that allows for the preparation of amidomethylated vinyl aromatic polymers in good yield. [Means for solving the problem]

[0009] Surprisingly, it has now been found that the reaction of a vinyl aromatic polymer with condensed formaldehyde and a protic acid in the presence of a C1-C5-difluoroalkane leads to an amidomethylated vinyl aromatic polymer in high yield. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention therefore comprises the step of: mixing at least one vinyl aromatic polymer with at least one compound of formula (I) [ka] (wherein R1 = -C(H(C1-C6-alkyl))- or -CH2- and R2 = -C(H(C1-C6-alkyl))- or -CH2-, or R1 and R2 are two carbon atoms of an aromatic C6 ring optionally substituted with one or two C1-C6-alkyl groups, or R1 and R2 are each -CH=) or a salt thereof, A method for preparing an amidomethylated vinyl aromatic polymer is provided, which comprises reacting at least one condensed formaldehyde in the presence of at least one protonic acid and at least one linear or branched C1-C5-difluoroalkane, or at least one cyclic C5-difluoroalkane, or a mixture of these compounds.

[0011] Preferably, R1 and R2 combine to form a C1-C6 alkyl-substituted aromatic C6 ring. More preferably, R1 and R2 form a benzene ring optionally substituted with C1-C4 alkyl. The compound of formula (I) is particularly preferably phthalimide, succinimide, or maleimide. The compound of formula (I) is even more preferably phthalimide. When phthalimide is used, phthalimide-methylated polymers are prepared according to the present invention. Salts of compounds of formula (I) are preferably understood to be addition products of inorganic or organic alkalis, such as ammonium salts and alkali metal or alkaline earth metal salts, with the compound of formula (I). Any salts used are more preferably sodium and potassium salts of compounds of formula (I).

[0012] In the context of the present invention, C1-C6-alkyl and C1-C4-alkyl are straight-chain, branched or cyclic alkyl radicals having 1 to 6 or 1 to 4 carbon atoms, for example and preferably C1-C6-alkyl is methyl, ethyl, n-propyl, isopropyl, n-, i-, s- or t-butyl, cyclopropyl, n-propyl, 1-methylbutyl.

[0013] For example and preferably, C1-C4-alkyl is methyl, ethyl, n-propyl and isopropyl.

[0014] The C1-C5-difluoroalkane is preferably a C1-C3-difluoroalkane, for example and preferably difluoromethane, 1,1-difluoroethane, 1,2-difluoroethane, 1,1-difluoropropane, 1,2-difluoropropane, 1,3-difluoropropane, 1,1-difluorobutane, 1,2-difluorobutane, 1,3-difluorobutane, 1,4-difluorobutane, 2,3-difluorobutane, 1,3-difluoro-2-methylpropane, 1,1-difluoropentane, 1,2-difluoropentane, 1,3-difluoropentane, 1,4-difluoropentane, 1,5-difluoropentane, 2,3-difluoropentane, 2,4-difluoropentane, and 1,5-difluoropentane, or a mixture of these compounds. The cyclic C5-difluoroalkane is preferably 1,1-difluorocyclopentane and 1,2-difluorocyclopentane. More preferably, the C1-C5-difluoroalkane is difluoromethane, difluoroethane, and difluoropropane. Most preferably, the C1-C5-difluoroalkane and C1-C3-difluoroalkane are difluoromethane and 1,3-difluoropropane.

[0015] C1-C5-difluoroalkanes and cyclic C5-difluoroalkanes are swelling agents for the polymer, but also act as solvents for other reactants in the amidomethylation reaction. It is also possible to add additional organic swelling agents to the amidomethylation reaction. The additional organic swelling agents added can be, for example and preferably, benzotrifluoride, dibromomethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,3-dichloropropane, 1,4-dichlorobutane, 1,6-dichlorohexane, methylene chloride, carbon tetrachloride, trichloroethane, chlorobenzene, 1,2-dichlorobenzene, or nitro-substituted hydrocarbons such as nitropropane, nitrobenzene, or, for example, cyclic hydrocarbons such as cyclohexane and methylcyclohexane. It is preferred not to use additional swelling agents and / or solvents.

[0016] Preferably, the weight-based amount of C1-C5-difluoroalkane and / or cyclic C5-difluoroalkane in the swelling agent used is 80% to 100% by weight. More preferably, the weight-based amount of C1-C5-difluoroalkane and / or cyclic C5-difluoroalkane in the swelling agent used is 90% to 100% by weight. Most preferably, the weight-based amount of C1-C5-difluoroalkane and / or cyclic C5-difluoroalkane in the swelling agent used is 98% to 100% by weight.

[0017] Condensed formaldehyde means a condensation product of formaldehyde. Compounds of this type are prepared by conventional methods known to those skilled in the art. Compounds used as condensed formaldehyde include, for example, and preferably, compounds of formula (II): [ka] (wherein n=8 to 100). It is preferable to use a compound of formula (II) where n=8 to 30.

[0018] However, it is also possible to use cyclic condensates such as trioxane. The condensed formaldehyde used is more preferably paraformaldehyde or trioxane, or a mixture of these compounds. The condensed formaldehyde used is most preferably paraformaldehyde.

[0019] The protonic acid used may be, for example, an inorganic or organic protonic acid. The inorganic protonic acid used may be, for example, hydrochloric acid, sulfuric acid, oleum, nitric acid, nitrous acid, sulfurous acid, aliphatic or aromatic methane-, benzene- or toluenesulfonic acid, or phosphoric acid. The organic protonic acid used may be, for example, oxalic acid, acetic acid, or formic acid. It is preferable to use an inorganic protonic acid. The protonic acid used is more preferably sulfuric acid or oleum.

[0020] The polymer of the present invention is preferably spherical. The polymer preferably has a diameter of 200 μm to 1000 μm. A polymer in the shape of a bead is called a bead polymer.

[0021] In the context of the present invention, the term "vinyl aromatic" includes polyvinyl aromatic and monovinyl aromatic monomers. A vinyl aromatic polymer is prepared, for example, using at least one monovinyl aromatic compound and at least one polyvinyl aromatic compound. However, it is also possible to use a mixture of two or more monovinyl aromatic compounds and a mixture of two or more polyvinyl aromatic compounds. It is preferred to prepare a vinyl aromatic polymer by using at least one monovinyl aromatic compound and at least one polyvinyl aromatic compound.

[0022] The monovinyl aromatic compounds used in connection with the present invention are preferably styrene, vinyltoluene, ethylstyrene, α-methylstyrene, chlorostyrene and chloromethylstyrene.

[0023] It is particularly preferable to use styrene or a mixture of styrene with the aforementioned monomers.

[0024] In the context of the present invention, preferred polyvinylaromatic compounds are divinylbenzene, divinyltoluene, trivinylbenzene, triallyl isocyanurate, divinylnaphthalene or trivinylnaphthalene.

[0025] The polyvinylaromatic compound is preferably used in an amount of 1 to 20% by weight, more preferably 2 to 12% by weight, and most preferably 4 to 10% by weight, based on the monomer or its mixture with further monomers. The type of polyvinylaromatic compound (crosslinker) is selected with reference to the subsequent use of the polymer. In many cases, divinylbenzene is preferred. Commercially available divinylbenzene grades, which in addition to divinylbenzene isomers also contain ethylvinylbenzene, are sufficient for most applications.

[0026] In a preferred embodiment, the vinyl aromatic polymer is a styrene / divinylbenzene-crosslinked copolymer.

[0027] In a preferred embodiment of the present invention, microencapsulated monomer droplets are used.

[0028] Possible materials for the microencapsulation of the monomer droplets are those known for use as complex coacervates, in particular polyesters, natural and synthetic polyamides, polyurethanes, polyureas.

[0029] Gelatin, a natural polyamide, is particularly well suited, for example and preferably. It is employed in particular as a coacervate and complex coacervate. For the purposes of the present invention, gelatin-containing complex coacervates are understood to mean, in particular, a combination of gelatin with a synthetic polyelectrolyte. Suitable synthetic polyelectrolytes are, for example, copolymers containing units of maleic acid, acrylic acid, methacrylic acid, acrylamide, and methacrylamide. The use of acrylic acid and acrylamide is particularly preferred. Gelatin-containing capsules can be hardened with conventional hardeners such as formaldehyde or glutaric dialdehyde. The encapsulation of monomer droplets with gelatin, gelatin-containing coacervates, and gelatin-containing complex coacervates is described in detail in EP-A0 046 535. Methods of encapsulation with synthetic polymers are known. One highly suitable method is phase interface condensation, in which a reactive component, such as an isocyanate or acyl chloride, dissolved in the monomer droplets is reacted with a second reactive component, such as an amine, dissolved in the aqueous phase.

[0030] The optionally microencapsulated monomer droplets optionally contain an initiator or a mixture of initiators to induce polymerization. Initiators suitable for the method of the present invention are preferably peroxy compounds such as dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butylperoxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane or tert-amylperoxy-2-ethylhexane, and azo compounds such as 2,2'-azobis(isobutyronitrile) or 2,2'-azobis(2-methylisobutyronitrile). Most preferably, dibenzoyl peroxide is used.

[0031] The initiator is preferably used in an amount of 0.05% to 2.5% by weight, more preferably 0.1% to 1.5% by weight, based on the monomer mixture.

[0032] In order to generate a macroporous structure in the polymer, a porogen can be optionally used as an additional additive in the optionally microencapsulated monomer droplets. Suitable porogens include organic solvents that are poor solvents and / or swelling agents for the polymer being formed. Hexane, octane, isooctane, isododecane, methyl ethyl ketone, butanol or octanol, and their isomers are preferred. Isododecane is particularly preferred as the porogen. It is preferred to use a porogen in the preparation of the amidomethylated vinyl aromatic polymer of the present invention.

[0033] The terms "microporous" and "gel-form" / "macroporous" have already been explained in detail in the technical literature.

[0034] For the purposes of the present invention, preferred polymers have a macroporous structure.

[0035] In the context of the present invention, "macroporous" preferably means that the average diameter of the pores in the polymer is ≥ 25 nm. More preferably, the pores in the macroporous polymer have an average diameter of 30 nm to 1000 nm. Most preferably, the pores in the macroporous polymer have an average diameter of 30 nm to 100 nm.

[0036] In the context of the present invention, "gel form" means a gel having a BET surface area of ​​≦2 m 2 / g. The BET surface area of ​​the polymer when in gel form is preferably 0.02 m 2 / g~2m 2 / g.

[0037] The optionally microencapsulated monomer droplets may also optionally contain up to 30% by weight (based on monomers) of a crosslinked or uncrosslinked polymer. Preferred polymers are derived from the aforementioned monomers, particularly preferably styrene.

[0038] The polymers can be prepared in heterodisperse or monodisperse form. The preparation of heterodisperse polymers is achieved by common methods known to those skilled in the art, for example, using suspension polymerization.

[0039] In the process of the present invention, the preparation of monodisperse vinyl aromatic polymers is preferred.

[0040] In this application, a monodisperse material is one in which at least 90% by volume or 90% by weight of the particles have a diameter within ±10% of the modal diameter.

[0041] For example, for a material with a modal diameter of 0.5 mm, at least 90% by volume or 90% by mass is within the particle size interval of 0.45 mm to 0.55 mm; for a material with a modal diameter of 0.7 mm, at least 90% by volume or 90% by mass is within the particle size interval of 0.77 mm to 0.63 mm.

[0042] Monodisperse polymers can be prepared by methods known in the literature. The aqueous phase involved in the preparation of monodisperse vinyl aromatic polymers may optionally contain a dissolved polymerization inhibitor. Preferably, the aqueous phase does not contain a dissolved polymerization inhibitor. Both organic and inorganic inhibitors are useful for the purposes of the present invention. Examples of inorganic inhibitors include nitrogen compounds such as hydroxylamine, hydrazine, sodium nitrite and potassium nitrite, salts of phosphorous acid such as sodium hydrogen phosphite, and sulfur compounds such as sodium dithionite, sodium thiosulfate, sodium sulfite, sodium hydrogen sulfite, sodium thiocyanate and ammonium thiocyanate. Examples of organic inhibitors are phenolic compounds such as hydroquinone, hydroquinone monomethyl ether, resorcinol, catechol, tert-butylcatechol, pyrogallol, and condensates of phenols with aldehydes. Suitable organic inhibitors also include nitrogen compounds. These include, for example, hydroxylamine derivatives such as N,N-diethylhydroxylamine, N-isopropylhydroxylamine, and sulfonated or carboxylated N-alkylhydroxylamines or N,N-dialkylhydroxylamine derivatives; hydrazine derivatives such as N,N-hydrazinodiacetic acid; and nitroso compounds such as N-nitrosophenylhydroxylamine, N-nitrosophenylhydroxylamine ammonium salt, or N-nitrosophenylhydroxylamine aluminum salt. The concentration of the inhibitor is preferably 5 to 1000 ppm, more preferably 10 to 500 ppm, and even more preferably 10 to 250 ppm, based on the aqueous phase. The use of resorcinol as a polymerization inhibitor is preferred. The use of a polymerization inhibitor is preferred.

[0043] Polymerization of the optionally microencapsulated monomer droplets to form the monodisperse vinyl aromatic polymer is optionally carried out in the presence of one or more protective colloids in the aqueous phase, as described above. Useful protective colloids include natural or synthetic water-soluble polymers, such as gelatin, starch, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid, or copolymers formed from (meth)acrylic acid and (meth)acrylic acid esters. Very useful protective colloids also include cellulose derivatives, particularly cellulose esters and cellulose ethers, such as carboxymethyl cellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose, and hydroxyethyl cellulose. Gelatin is particularly suitable and is preferably used. The amount of protective colloid used is preferably 0.05% to 1% by weight, more preferably 0.05% to 0.5% by weight, based on the aqueous phase.

[0044] The polymerization to form the monodisperse vinyl aromatic polymer can optionally be carried out in the presence of a buffer system. A buffer system that adjusts the pH of the aqueous phase at the start of the polymerization to a value between 14 and 6, preferably between 12 and 8, is preferred. Under these conditions, protective colloids containing carboxylic acid groups are present completely or partially as salts, which favorably influence the action of the protective colloid. Particularly suitable buffer systems contain phosphates or borates. For the purposes of the present invention, the terms "phosphate" and "borate" also include the ortho-form condensates of the corresponding acids and salts. The concentration of the phosphate / borate in the aqueous phase is preferably 0.5 to 500 mmol / l, more preferably 2.5 to 100 mmol / l.

[0045] The agitation speed in the polymerization is not very important and does not affect particle size. A sufficiently low agitation speed is utilized to maintain the suspended monomer droplets in suspension and to facilitate removal of the heat of polymerization. Various agitator types can be used for this operation. A particularly suitable agitator is an axial-action gate agitator.

[0046] The volume ratio of the encapsulated monomer droplets to the aqueous phase is preferably 1:0.75 to 1:20, more preferably 1:1 to 1:6.

[0047] The polymerization temperature depends on the decomposition temperature of the initiator used. This is preferably 50°C to 180°C, more preferably 55°C to 130°C. The polymerization preferably lasts for 0.5 hours to several hours. It has been found useful to use a temperature program in which the polymerization is initiated at a low temperature, for example, 60°C, and the reaction temperature is increased as the polymerization conversion rate increases. In this way, for example, it is possible to very efficiently meet the requirements for steady reaction progress and high polymerization conversion rate. After polymerization, the polymer is isolated by conventional methods, preferably by filtration or decantation, and optionally washed.

[0048] A vinyl aromatic polymer is reacted with at least one compound of formula (I), at least one condensed formaldehyde in the presence of a C1-C5-difluoroalkane or a cyclic C5-difluoroalkane, or a mixture of these compounds, and in the presence of at least one protonic acid to form an amidomethylated vinyl aromatic polymer.

[0049] For example, the vinyl aromatic polymer can be first swollen in the presence of a C1-C5-difluoroalkane and / or a cyclic C5-difluoroalkane, and then mixed in this state with a mixture formed from the compound of formula (I), condensed formaldehyde, and protonic acid. However, it is equally possible to first add the compound of formula (I) to the crosslinked polymer in the presence of a C1-C5-difluoroalkane and / or a cyclic C5-difluoroalkane, then add the condensed formaldehyde, and then add the protonic acid. Alternatively, the protonic acid can be added to the compound of formula (I), condensed formaldehyde, C1-C5-difluoroalkane, and / or cyclic C5-difluoroalkane that have been initially charged, and then the vinyl aromatic polymer can be added thereto. Preferably, the crosslinked polymer is first swollen in the presence of a C1-C5-difluoroalkane and / or a cyclic C5-difluoroalkane, then the compound of formula (I) or condensed formaldehyde is added, and then a protonic acid is added. The C1-C5-difluoroalkane and / or the cyclic C5-difluoroalkane is preferably separated by distillation or reduced pressure. The reaction product is post-treated by a method known to those skilled in the art. The reaction mixture is preferably heated. The reaction is preferably carried out as a one-pot reaction.

[0050] Preferably, the weight ratio of C1-C5-difluoroalkane and / or cyclic C5-difluoroalkane to vinyl aromatic polymer is 15:1 to 3:1. More preferably, the weight ratio of C1-C5-difluoroalkane and / or cyclic C5-difluoroalkane to vinyl aromatic polymer is 10:1 to 4:1.

[0051] The molar ratio of aromatic groups in the vinyl aromatic polymer to the compound of formula (I) is preferably 0.2:1 to 2.5:1, and more preferably 0.5:1 to 1.8:1.

[0052] The molar ratio of the compound of formula (I) to the condensed formaldehyde is preferably 0.7:1 to 1.3:1, and more preferably 0.95:1 to 1.1:1.

[0053] The molar ratio of the compound of formula (I) to the protonic acid used is preferably 10:1 to 1:10. The molar ratio of the compound of formula (I) to the protonic acid used is more preferably 1:1 to 1:10.

[0054] When the protonic acid used is sulfuric acid, the concentration of the sulfuric acid used is preferably 70% by weight to 100% by weight, and more preferably 90% by weight to 100% by weight.

[0055] The reaction temperature for converting the vinyl aromatic polymer to the amidomethylated vinyl aromatic polymer is preferably 0°C to 130°C. The reaction is preferably carried out at a pressure and temperature at which the solvent is liquid. The pressure is preferably 1 to 60 bar. The reaction temperature is preferably 30°C to 90°C.

[0056] Amidomethylated vinylaromatic polymers are important intermediates, particularly for the preparation of ion exchangers and chelating resins. Thus, for example, ion exchangers, particularly anion exchangers, and chelating resins can be prepared from the amidomethylated vinylaromatic polymers prepared by the process of the present invention.

[0057] The amidomethylated vinylaromatic polymer can then be converted into an aminomethylated vinylaromatic polymer in a further step. The amidomethylated vinylaromatic polymer is preferably further converted into an aminomethylated vinylaromatic polymer. The conversion is preferably carried out by treating the amidomethylated vinylaromatic polymer with an aqueous or alcoholic solution of an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, at a temperature of 100°C to 250°C, preferably 120°C to 190°C. The conversion is preferably carried out with an alkali metal hydroxide or alkaline earth metal hydroxide, or a mixture of these compounds, more preferably an alkali metal hydroxide, especially sodium hydroxide. The conversion is preferably carried out in the presence of an aqueous or alcoholic solution of an alkali metal hydroxide. The concentration of the sodium hydroxide solution is in the range of 10% to 50% by weight, preferably 20% to 40% by weight.

[0058] The aminomethylated vinyl aromatic polymer formed here can be washed with thoroughly deionized water to remove the alkali.

[0059] The aminomethylated vinyl aromatic polymers can be reacted with additional alkylating agents to give anion exchangers or chelating resins, or can be used as ion exchangers.

[0060] Additionally, the aminomethylated vinyl aromatic polymers of the present invention can be reacted with halomethyl nitrogen heterocycles, such as 2-chloromethylpyridine, 3-chloromethylpyridine, or 4-chloromethylpyridine, to prepare chelating resins.

[0061] The present invention provides a novel method for preparing amidomethylated vinyl aromatic polymers, particularly phthalimidomethylated and aminomethylated polymers, in high yield while taking environmental considerations into account. [Example]

[0062] Example 1 1.1 Preparation of monodisperse macroporous polymers based on styrene, divinylbenzene, and ethylstyrene First, 3000 g of purified water was charged into a 10 L glass reactor, and a solution of 10 g of gelatin, 16 g of disodium hydrogen phosphate·12-dihydrate, and 0.73 g of resorcinol in 320 g of deionized water was added and mixed. The temperature of the mixture was adjusted to 25°C. Then, while stirring, 3200 g of microcapsule monomer droplets with a narrow particle size distribution (used in the form of a commercial isomeric mixture of divinylbenzene and ethylstyrene (80% divinylbenzene)), 0.4% by weight of dibenzoyl peroxide, 58.4% by weight of styrene, and 37.5% by weight of isododecane (a technical isomeric mixture with a high proportion of pentamethylheptane) are added, followed by microcapsules consisting of a formaldehyde-hardened complex coacervate composed of gelatin, a copolymer of acrylamide and acrylic acid, and 3200 g of an aqueous phase having a pH of 12.

[0063] The mixture is stirred and polymerized completely by increasing the temperature according to a temperature program starting at 25° C. and ending at 95° C. The mixture is cooled, washed through a 32 μm sieve, and then dried at 80° C. under reduced pressure.

[0064] This gives 1893 g of polymer with a narrow particle size distribution: the average diameter of the pores in the polymer is 42 nm.

[0065] 1.2. Preparation of phthalimidomethylated monodisperse macroporous polymers with swelling agent 1,3-difluoropropane A round-bottom flask is first charged with 29.5 g of 1,3-difluoropropane. 4.1 g of the polymer from Example 1.1, 5.9 g (0.04 mol) of phthalimide, and 1.2 g (0.04 mol) of paraformaldehyde (n = 8-30) (96 wt%) are added, and the mixture is then left under stirring at room temperature for 30 minutes. 14.6 g (0.14 mol) of sulfuric acid (96 wt%) is added dropwise within 30 minutes, and the mixture is then stirred at 40 °C for 24 hours. The beads are then separated using a sieve and washed with water, acetone, and water. Volume yield: 23 ml Nitrogen content (after drying): 5.1% by weight

[0066] In the context of the present invention, yield means the degree of functionalization of the polymer, expressed by the nitrogen content, which is greater in the inventive examples than in the comparative examples.

[0067] Example 2 Comparative Example (not of the present invention) 2.1 Preparation of phthalimidomethylated monodisperse macroporous polymers with swelling agent 1,2-dichloroethane A round-bottom flask is first charged with 29.7 g of 1,2-dichloroethane. 4.1 g of the polymer from Example 1.1, 5.9 g (0.04 mol) of phthalimide, and 1.2 g (0.04 mol) of paraformaldehyde (n = 8-30) (96 wt%) are added, and the mixture is then left under stirring at room temperature for 30 minutes. 14.6 g (0.14 mol) of sulfuric acid (96 wt%) is added dropwise within 30 minutes, and the mixture is then stirred at 40 °C for 24 hours. The beads are then separated using a sieve and washed with water, acetone, and water. Volume yield: 25 ml Nitrogen content (after drying): 4.9% by weight

Claims

1. At least one vinyl aromatic polymer is reacted with at least one compound of formula (I) 【Chemistry 1】 (In the formula, R １ = -C(H(C １ ~C ６ -alkyl))- or -CH ２ - and R ２ = -C(H(C １ ~C ６ -alkyl))- or -CH ２ - or R １ and R ２ is one or two C １ ~C ６ - an aromatic C optionally substituted with an alkyl group ６ two carbon atoms of the ring, or R １ and R ２ each is —CH═) or a salt thereof; at least one condensed formaldehyde; in the presence of at least one protonic acid, and At least one linear or branched chain C １ ~C ５ -difluoroalkane or at least one cyclic C ５ in the presence of a difluoroalkane or a mixture of these compounds 1. A method for preparing an amidomethylated vinyl aromatic polymer, comprising reacting

2. Said C １ ~C ５ 2. The method according to claim 1, wherein the difluoroalkane is selected from the group consisting of difluoromethane, 1,1-difluoroethane, 1,2-difluoroethane, 1,1-difluoropropane, 1,2-difluoropropane, 1,3-difluoropropane, 1,1-difluorobutane, 1,2-difluorobutane, 1,3-difluorobutane, 1,4-difluorobutane, 2,3-difluorobutane, 1,3-difluoro-2-methylpropane, 1,1-difluoropentane, 1,2-difluoropentane, 1,3-difluoropentane, 1,4-difluoropentane, 1,5-difluoropentane, 2,3-difluoropentane, 2,4-difluoropentane and 1,5-difluoropentane, or mixtures of these compounds.

3. The C used １ ~C ５ 3. The process according to claim 1, wherein the difluoroalkane is difluoromethane or 1,3-difluoropropane.

4. The cyclic C ５ 4. The process according to claim 1, wherein the difluoroalkanes are 1,1-difluorocyclopentane and 1,2-difluorocyclopentane.

5. 5. The method according to claim 1, wherein the condensed formaldehyde used is paraformaldehyde or trioxane, or a mixture of these compounds.

6. A method according to any one of claims 1 to 5, characterized in that the vinyl aromatic bead polymer used is a styrene-divinylbenzene copolymer.

7. 7. The method according to claim 1, wherein the compound of formula (I) used is phthalimide or a salt thereof.

8. A method according to any one of claims 1 to 7, characterized in that the vinyl aromatic polymer used is a monodisperse vinyl aromatic polymer.

9. 9. The method according to claim 1, wherein the pores of the vinyl aromatic polymer used have a diameter of ≧25 nm.

10. C １ ~C ５ A method according to any one of claims 1 to 9, characterized in that the weight ratio of difluoroalkane to said vinyl aromatic polymer is between 10:1 and 4:

1.

11. 11. The method of any one of claims 1 to 10, wherein the molar ratio of the aromatic groups in the vinyl aromatic bead polymer to the compound of formula (I) is from 0.5:1 to 1.8:

1.

12. 12. The process according to any one of claims 1 to 11, characterized in that the molar ratio of the compound of formula (I) to the condensed formaldehyde is between 0.95:1 and 1.1:

1.

13. 13. The process according to any one of claims 1 to 12, characterized in that the molar ratio of the compound of formula (I) to the protic acid used is between 10:1 and 1:

10.

14. 14. The method according to any one of claims 1 to 13, characterized in that the reaction temperature for converting the vinyl aromatic polymer into the amidomethylated vinyl aromatic polymer is between 30°C and 90°C.

Images