Boosted styrene polymerization retarder and method of use

Abstract

A product and method for reducing fouling of a vinyl aromatic monomer including an effective amount of one or more sulfonic acids in combination with an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders, or mixtures thereof.

Description

BOOSTED STYRENE POLYMERIZATION RETARDER AND METHOD OF USECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of United States Provisional Application Serial No. 63 / 633,293 filed April 12, 2024, the contents of which is incorporated herein by reference.FIELD

[0002] The disclosed technology relates to products, compositions, and methods for reducing fouling during production of vinyl aromatic monomers, such as styrene monomers. In particular, the disclosed technology relates to products, compositions, and methods for reducing fouling during production of vinyl aromatic monomers, comprising polymerization inhibitors, polymerization retarders, and sulfonic acids.BACKGROUND

[0003] During the production and purification of vinyl monomers, such as styrene, polymer is generated due to thermal polymerization of the vinyl monomers, and occasionally, co-polymerization with other contaminant reactive monomer species. The amount of polymer depends on temperature, time, the presence of any catalysts or contaminants, and any other reactive monomers (e.g. divinylbenzene). The undesired polymer can foul process equipment and piping and cause a number of processing, production, and product quality problems such as product contamination.

[0004] Hence, it is desirable to minimize the amount of polymer to be able to meet production and reliability goals. The conventional approach is to use a combination of at least one true polymerization inhibitor and a polymerization retarder to minimize the amount of polymer produced, and prevent the associated fouling and heat transfer problems. However, conventional treatment programs contain highly toxic components, very expensive components, or both.

[0005] A different approach for fouling control in vinyl aromatic monomer production processes is needed.SUMMARY

[0006] The disclosed technology provides for controlling fouling of vinyl aromatic monomers, such as styrene monomers, using products and compositions comprising polymerization inhibitors, polymerization retarders, and sulfonic acids.

[0007] Various aspects of the disclosure relate to a product for reducing fouling during the production of a vinyl aromatic monomer comprising an effective amount of one or more sulfonic acids in combination with an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders, or mixtures thereof.

[0008] In various aspects, the product may include a first composition comprising an effective amount of one or more sulfonic acids and a second composition comprising a mixture of an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

[0009] In various aspects, the product may include a first composition comprising an effective amount of one or more sulfonic acids, a second composition comprising an effective amount of one or more polymerization inhibitors, and a third composition comprising an effective amount of one or more polymerization retarders.

[0010] In various aspects, the product may include a first composition comprising an effective amount of one or more sulfonic acids, and a second composition comprising an effective amount of one or more polymerization retarders.

[0011] Various aspects of the disclosure additionally relate to a method of controlling fouling of a vinyl aromatic monomer comprising adding to the monomer an effective amount of one or more sulfonic acids in combination with an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders, or mixtures thereof.

[0012] In various aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more sulfonic acids, and a second composition comprising an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

[0013] In various aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more sulfonic acids, a second composition comprising an effective amount of one or more polymerization inhibitors, and a third composition comprising an effective amount of one or more polymerization retarders.

[0014] In various aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more sulfonic acids, and a second composition comprising an effective amount of one or more polymerization retarders.BRIEF DESCRIPTION OF THE FIGURES

[0015] Those of skill in the art will understand that the figures, described below, are for illustrative purposes only. The figures are not intended to limit the scope of the present teachings in any way.

[0016] FIG. 1 illustrates the amount of polymer formed in a styrene / divinylbenzene (DVB) mixture after treatment with an embodiment of the product of the disclosure, as compared to conventional treatment.

[0017] FIG. 2 illustrates the percent polymer formed in a styrene / divinylbenzene (DVB) mixture after treatment with another embodiment of the product of the disclosure, as compared to conventional treatment.

[0018] FIG. 3 illustrates the percent polymer formed in a styrene / divinylbenzene (DVB) mixture after treatment with various embodiments of the product of the disclosure.

[0019] FIG. 4 illustrates the percent polymer formed in a styrene / divinylbenzene (DVB) mixture after treatment with various embodiments of the product of the disclosure.

[0020] FIG. 5 illustrates the percent polymer formed in a styrene / divinylbenzene (DVB) mixture after treatment with various embodiments of the product of the disclosure.DETAILED DESCRIPTION

[0021] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, is not limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Range limitations may be combined and / or interchanged, and such ranges are identified and include all the sub-ranges stated herein unless context or language indicates otherwise. Other than in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions and the like, used in the specification and the claims, are to be understood as modified in all instances by the term “about”.

[0022] “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, or that the subsequently identified material may or may not be present, and that the description includes instances where the event or circumstance occurs or where the material is present, and instances where the event or circumstance does not occur or the material is not present.

[0023] As used herein, the terms “comprises”, “comprising”, “includes”, “including”, “has”, “having”, or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article or apparatus that comprises a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0024] The singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0025] The disclosed technology provides for products and methods for reducing fouling of vinyl aromatic monomers, such as styrene monomers, using compositions comprising polymerization inhibitors, sulfonic acids, and, optionally, polymerization retarders.

[0026] The products, compositions, and methods disclosed herein have been found to be effective in reducing the amount of undesirable polymers in styrene production processes, for example, insoluble crosslinked divinylbenzene-styrene copolymers.

[0027] As used herein, the term “polymerization inhibitor” refers to chemical compounds added to monomers, such as vinyl aromatic monomers, to prevent their autopolymerization.

[0028] As used herein, the term “polymerization retarder” refers to molecules that reduce the rate of polymerization of monomers such as vinyl aromatic monomers.

[0029] As used herein, the term “an effective amount” refers to any amount of a sulfonic acid, polymerization inhibitor and / or polymerization retarder that is effective in inhibiting polymerization of a vinyl aromatic monomer.

[0030] In various aspects of the disclosed technology, a product for controlling fouling of a vinyl aromatic monomer is disclosed. In various aspects, the product may include an effective amount of one or more sulfonic acids, and an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders. In some aspects, the product may include an effective amount of one or more sulfonic acids, an effective amount of one or more polymerization retarders, and, optionally, an effective amount of one or more polymerization inhibitors.

[0031] In some aspects, the product may include a first composition including an effective amount of one or more sulfonic acids, and a second composition including an effective amount of one or more polymerization retarders.

[0032] In some aspects, the product may include a first composition including an effective amount of one or more sulfonic acids, and a second composition including an effective amount of one or more polymerization inhibitors.

[0033] In some aspects, the product may include a first composition including an effective amount of one or more sulfonic acids, and a second composition including an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

[0034] In other aspects, the product may include a first composition including an effective amount of one or more sulfonic acids, a second composition including an effective amount of one or more polymerization inhibitors, and a third composition comprising an effective amount of one or more polymerization retarders.

[0035] In various aspects, suitable sulfonic acids may include any sulfonic acid capable of catalyzing a polymerization inhibitor or retarder reaction when used in combination with a polymerization inhibitor and / or polymerization retarder. In some aspects, suitable sulfonic acids may include, but are not limited to, dodecyl benzene sulfonic acid (DDBSA).

[0036] In various aspects, the sulfonic acids may be present in an amount of between about 1 ppm to about 1000 ppm, or about 1, 10, 50, 100, 150, 200, 250, 300, 350, 400, 450,500, 550, 600, 650, 700, 750, 800, 850, 900, 950, or 1000 ppm, or about 1 ppm to about 100 ppm or about 1 ppm to about 50 ppm, or about 50 ppm to about 100 ppm, or any amount between any of these values.

[0037] In various aspects, suitable polymerization inhibitors may include any compound added to monomers, such as vinyl aromatic monomers, that prevent their autopolymerization. In some aspects, suitable polymerization inhibitors may include, but are not limited to, hydroxylamine derivatives, phenolic-containing inhibitors, stable nitroxyl radicals, or combinations thereof.

[0038] Suitable hydroxylamine derivatives may include, but are not limited to, hydroxylamines having the functional group — NOH — and the general formula Rl-NOH — R2. R1 and R2 may be the same or different and are hydrogen, alkyl, aryl, alkaryl, or hydroxyalkyl groups and may have three to about twenty carbon atoms. In some aspects, suitable hydroxylamine derivatives include 2-propanol, l,l'-(hydroxyimino)bis, 1,1'- (hydroxyimino)dipropan-2-ol, bis l,l-(2-Propanol)-hydroxyimine, or N,N-bis(2- hydroxypropyl)hydroxylamine (HPHA). In various aspects, suitable polymerization inhibitors may further include phenolic containing inhibitors, such as 4-tert-butylcatechol, butylated hydroxy toluene, 2,6-ditertbutylphenol, and combinations thereof.

[0039] In various aspects, the polymerization inhibitors may be formulated with a stable free radical. Suitable stable free radicals may include, but are not limited to, nitroxylcompounds, such as 4-hydroxy-2,2,6,6-tetramethyl-l-piperidinyloxy, or tetramethylpiperidino-N-oxyl, or l-oxyl-2,2,6,6-tetramethyl-4-piperidinol, or the like.

[0040] In various aspects, suitable polymerization retarders may include any molecule that reduces the rate of polymerization of monomers, such as vinyl aromatic monomers. In various aspects, suitable polymerization retarders may include, but are not limited to, dinitro phenolic compounds, including 2,6-dinitro-p-cresol, 2,4-dinitrophenol, 2,4-dinitro-o-cresol, and 2, 4-dinitro-6-sec -butylphenol; quinone methide and quinone methide derivatives. The quinone methide (QM) compound has the formula:

[0041] wherein R3 and R4 are independently H, Cl to C18 alkyl, C5 to C12 cycloalkyl; or C7 to C15 phenylalkyl, and R5 is aryl, or aryl substituted with Cl to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy or mixtures thereof. In various aspects, suitable quinone methide derivatives may include 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone.

[0042] In various aspects, the polymerization inhibitors and polymerization retarders are included in any amount that is sufficient to inhibit polymerization of vinyl aromatic monomers. In some aspects of the method, concentrations of polymerization retarders and / or polymerization inhibitors may range from about 1 ppm to about 10000 ppm or about 1, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, or 10000 ppm, or any amount in between any of these values. These amounts may vary according to the conditions under which the vinyl aromatic monomer is being processed, contaminants in the system, and the temperature of the system. At higher processing temperatures and higher monomer contamination, larger amounts of polymerization inhibitors and polymerization retarders may be required.

[0043] In various aspects, the first composition, second composition and / or third composition may include a liquid carrier. Suitable liquid carriers may include, but are not limited to, water, non-polar organic solvents, and combinations thereof. In some aspects, suitable liquid carriers may include toluene, ethyl benzene, aromatic solvent, or the like.

[0044] In various aspects, the product of the disclosure may further include an amine, an amine-based polymer, or mixtures thereof. Without being bound by theory, it is believed that amines, amine-based polymers, and mixtures thereof may be effective in reducing the corrosivity of the sulfonic acid component of the product of the disclosure. Accordingly, the amine, amine-based polymer, or mixture thereof, may be used in a method to reduce the corrosivity of the product of the disclosure. Suitable amines may include, but are not limited to, diethanolamine (DEA), diisopropanolamine (DIPA), or the like. Suitable amine-based polymers may include reaction product of formaldehyde with 4-nonylphenol and ethylene diamine, or the like.

[0045] In various aspects, the amine, amine-based polymer, or mixture thereof may be present in the product in an amount of from 1 ppm to an equivalent concentration of sulfonic acid that is present in the product, or from about 1 ppm to about 1000 ppm, or about 1, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, or any amount between any of these values. In some aspects, the amine, amine- based polymer, or mixture thereof, may be present in the product in a ratio of 1 part amine, amine-based polymer, or mixture thereof to 18 parts sulfonic acid.

[0046] In various aspects, the product of the disclosure may further include tetrapropenyl-butanedioic acid.

[0047] In various aspects, the product of the disclosed technology may be used in a method of inhibiting the polymerization of vinyl aromatic monomers. In various aspects, the method may include adding to the monomer an effective amount of one or more sulfonic acids, an effective amount of one or more polymerization inhibitors, and, optionally, an effective amount of one or more polymerization retarders. In some aspects, the method may include adding to the monomer an effective amount of one or more sulfonic acids, an effective amount of one or more polymerization retarders, and, optionally, an effective amount of one or more polymerization inhibitors.

[0048] In some aspects, the method may include adding a first composition including an effective amount of one or more sulfonic acids, and a second composition including an effective amount of one or more polymerization retarders.

[0049] In some aspects, the method may include adding a first composition including an effective amount of one or more sulfonic acids, and a second composition including an effective amount of one or more polymerization inhibitors.

[0050] In some aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more sulfonic acids and a secondcomposition comprising an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

[0051] In other aspects, the method may include adding to the monomer a first composition comprising an effective amount of one or more sulfonic acids, a second composition comprising an effective amount of one or more polymerization inhibitors, and a third composition comprising an effective amount of one or more polymerization retarders.

[0052] In various aspects of the method, sulfonic acids may include any sulfonic acid capable of enhancing the dispersibility of polymers generated due to thermal polymerization of vinyl aromatic monomers when used in combination with a polymerization inhibitor and / or polymerization retarder. In some aspects, suitable sulfonic acids may include, but are not limited to, dodecyl benzene sulfonic acid (DDBSA).

[0053] In various aspects, the sulfonic acids may be present in an amount of between about 1 ppm to about 1000 ppm, or about 1, 10, 50, 100, 150, 200, 250, 300, 350, 400, 450,500, 550, 600, 650, 700, 750, 800, 850, 900, 950, or 1000 ppm, or about 1 ppm to about 100 ppm or about 1 ppm to about 50 ppm, or about 50 ppm to about 100 ppm, or any amount between any of these values.

[0054] In various aspects of the method, suitable polymerization inhibitors may include any compound added to monomers, such as vinyl aromatic monomers, that prevent their autopolymerization. In some aspects, suitable polymerization inhibitors may include, but are not limited to, hydroxylamine derivatives, phenolic-containing inhibitors, stable nitroxyl radicals, or combinations thereof.

[0055] Suitable hydroxylamine derivatives may include, but are not limited to, hydroxylamines having the functional group — NOH — and the general formula Rl-NOH — R2. R1 and R2 may be the same or different and are hydrogen, alkyl, aryl, alkaryl, or hydroxyalkyl groups and may have three to about twenty carbon atoms. In some aspects, suitable hydroxylamine derivatives include 2-propanol, l,l'-(hydroxyimino)bis, 1,1'- (hydroxyimino)dipropan-2-ol, bis l,l-(2-Propanol)-hydroxyimine, or N,N-bis(2- hydroxypropyl)hydroxylamine (HPHA). In various aspects, suitable polymerization inhibitors may further include phenolic containing inhibitors, such as 4-tert-butylcatechol, butylated hydroxy toluene, 2,6-ditertbutylphenol, and combinations thereof.

[0056] In various aspects, the method may further include addition of a stable free radical. Suitable stable free radicals may include, but are not limited to, nitroxyl compounds, such as 4-hydroxy-2,2,6,6-tetramethyl-l-piperidinyloxy, or tetramethylpiperidino-N-oxyl, or l-oxyl-2,2,6,6-tetramethyl-4-piperidinol, or the like.

[0057] In various aspects of the method, suitable polymerization retarders may include any molecule that reduces the rate of polymerization of monomers, such as vinyl aromatic monomers. In various aspects, suitable polymerization retarders may include, but are not limited to, dinitro phenolic compounds, including 2,6-dinitro-p-cresol, 2,4-dinitrophenol, 2,4- dinitro-o-cresol, and 2, 4-dinitro-6-sec -butylphenol; quinone methide; and quinone methide derivatives. The quinone methide (QM) compound has the formula:

[0058] wherein R3 and R4 are independently H, Cl to C18 alkyl, C5 to C12 cycloalkyl; or C7 to C15 phenylalkyl, and R5 is aryl, or aryl substituted with Cl to C6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy or mixtures thereof. In various aspects, suitable quinone methide derivatives may include 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone.

[0059] In various aspects, the polymerization inhibitors and polymerization retarders are included in any amount that is sufficient to inhibit polymerization of vinyl aromatic monomers. In some aspects of the method, concentrations of polymerization retarders and / or polymerization inhibitors may range from about 1 to about 10000 ppm or about 1, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, or 10000 ppm, or any amount in between any of these values. These amounts may vary according to the conditions under which the vinyl aromatic monomer is being processed, contaminants in the system, and the temperature of the system. At higher processing temperatures and higher monomer contamination, larger amounts of polymerization inhibitors and polymerization retarders may be required.

[0060] In various aspects of the method, the first composition, second composition and / or third composition may include a liquid carrier. Suitable liquid carriers may include, but are not limited to, water, non-polar organic solvents, and combinations thereof. In some aspects, suitable liquid carriers may include toluene, ethyl benzene, aromatic solvent, or the like.

[0061] In various aspects, the method may further include adding to the monomer an amine, an amine-based polymer, or mixtures thereof. Suitable amines may include, but are not limited to, diethanolamine (DEA), diisopropanolamine (DIP A), or the like. Suitable amine- based polymers may include reaction product of formaldehyde with 4-nonylphenol and ethylene diamine, or the like.

[0062] In various aspects, the amine, amine-based polymer, or mixture thereof may be added in an amount of from 1 ppm to an equivalent concentration of sulfonic acid that is added to the monomer, or from about 1 ppm to about 1000 ppm, or about 1, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, or any amount between any of these values. In some aspects, the amine, amine -based polymer, or mixture thereof, may be added in a ratio of 1 part amine, amine-based polymer, or mixture thereof to 18 parts sulfonic acid.

[0063] In various aspects, the method may further include adding to the monomer tetrapropenyl-butanedioic acid.

[0064] In various aspects, the method may include inhibiting polymerization of any vinyl aromatic monomer, including, but not limited to, styrene, bromostyrene, divinylbenzene and a- methylstyrene monomers, and combinations thereof.EXAMPLES

[0065] The present technology will be further described in the following examples, which should be viewed as being illustrative and should not be construed to narrow the scope of the disclosed technology or limit the scope to any particular embodiments.

[0066] Example 1

[0067] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with 30 ppm of hydroxylamine, 350 ppm of a composition including a quinone methide derivative and a phenol, and 50 ppm of DDBSA. The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 3 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 1).

[0068] Example 2

[0069] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with 30 ppm of hydroxylamine, 250 ppm of a composition including a quinone methide derivative and a phenol, and 50 ppm of DDBSA. The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 3 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 2)

[0070] Example 3 (Comparative)

[0071] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with 30 ppm of hydroxylamine, and 350 ppm of a composition including a quinone methide derivative and a phenol. The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 3 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 1).

[0072] Example 4 (Comparative)

[0073] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with 30 ppm of hydroxylamine, and 300 ppm of a composition including a quinone methide derivative and a phenol. The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 3 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 2).

[0074] As shown in FIGS. 1 and 2, the styrene / DVB mixtures of Examples 1 and 2, which were treated with a combination of a polymerization inhibitor, a polymerization retarder, and a sulfonic acid, exhibited reduced polymer formation when compared to the styrene / DVB mixtures of Examples 3 and 4, which were only treated with a polymerization inhibitor and polymerization retarder.

[0075] Example 5

[0076] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with the following treatment programs:

[0077] 30 ppm of hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 6.7 ppm reaction product of formaldehyde with 4-nonylphenol and ethylene diamine;

[0078] 30 ppm of hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 12 ppm DEA;

[0079] 30 ppm of hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 12 ppm DIPA;

[0080] 30 ppm of hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA.

[0081] The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 5 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 3).

[0082] Example 6

[0083] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with the following treatment programs:

[0084] 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 6.7 ppm reaction product of formaldehyde with 4-nonylphenol and ethylene diamine;

[0085] 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 12 ppm DEA;

[0086] 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 3.4 ppm reaction product of formaldehyde with 4-nonylphenol and ethylene diamine + 6 ppm DEA;

[0087] 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA.

[0088] The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 5 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was thenfiltered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 4).

[0089] Example 7

[0090] Reagent grade styrene with 100 ppm reagent grade divinylbenzene (DVB) was filtered through basic alumina to remove a stock 4-tertbutylcatechol (TBC) inhibitor. The styrene / DVB mixture was treated with the following treatment programs:

[0091] 30 ppm hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA;

[0092] 30 ppm hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 6.7 ppm reaction product of formaldehyde with 4-nonylphenol and ethylene diamine;

[0093] 30 ppm hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 12 ppm DEA;

[0094] 30 ppm hydroxylamine + 280 ppm quinone methide derivative plus phenol + 120 ppm of DDBSA + 12 ppm DIPA.

[0095] The treated mixture was sealed, purged with argon, and heated in an oil bath to 120°C for 5 hours. Periodically, the treated styrene / DVB mixture was sampled during the heating period and added to methanol to precipitate any polymer. This polymer was then filtered and weighed in order to calculate the percent polymer formed. This percent polymer data was then plotted against the sampling time to give an indication of treatment program efficacy. (See FIG. 5).

[0096] While embodiments of the disclosed technology have been described, it should be understood that the present disclosure is not so limited and modifications may be made without departing from the disclosed technology. The scope of the disclosed technology is defined by the appended claims, and all devices, processes, and methods that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.

Claims

CLAIMS1. A product for reducing fouling during the production of a vinyl aromatic monomer comprising an effective amount of one or more sulfonic acids in combination with an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders, or mixtures thereof.

2. The product of claim 1, wherein the product comprises: a first composition comprising an effective amount of one or more sulfonic acids; and a second composition comprising a mixture of an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

3. The product of claim 1, wherein the product comprises: a first composition comprising an effective amount of one or more sulfonic acids; a second composition comprising an effective amount of one or more polymerization inhibitors; and a third composition comprising an effective amount of one or more polymerization retarders.

4. The product of claim 1, wherein the product comprises: a first composition comprising an effective amount of one or more sulfonic acids; and a second composition comprising an effective amount of one or more polymerization retarders.

5. The product of any one of claims 1-3, wherein the one or more polymerization inhibitors comprises one or more phenolic containing inhibitors, one or more hydroxylamines, one or more stable nitroxyl radicals, or combinations thereof.

6. The product of claim 5, wherein the phenolic containing inhibitor is selected from 4- tert-butylcatechol, butylated hydroxy toluene, 2,6-ditertbutylphenol, and combinations thereof.

7. The product of claim 6, wherein the phenolic containing inhibitor is 2,6- ditertbutylphenol .

8. The product of claim 5, where in the one or more hydroxylamines comprises N,N-bis(2- hydroxypropyl)hydroxylamine (HPHA) .

9. The product of claim 5 wherein the one or more stable nitroxyl radicals comprises 4- hydroxy-2,2,6,6-tetramethyl-l-piperidinoxy.

10. The product of claim 5, wherein the one or more polymerization inhibitors comprises HPHA and 4-hydroxy-2,2,6,6-tetramethyl-l-piperidinoxy.

11. The product of any one of claims 1-4, wherein the one or more polymerization retarders comprises dinitro phenolic compounds, quinone methide, quinone methide derivatives, or combinations thereof.

12. The product of claim 11, wherein the dinitro phenolic compound is selected from the group consisting of 2,6-dinitro-p-cresol, 2,4-dinitrophenol, 2,4-dinitro-o-cresol, and 2,4- dinitro-6-sec -butylphenol, and combinations thereof.

13. The product of claim 12, wherein the dinitro phenolic compound is 2,4-dinitro-6-sec- butylphenol.

14. The product of claim 11, wherein the quinone methide derivative is 2,6-di-tert-butyl-4- benzylidene-cyclohexa-2,5-dienone.

15. The product of any one of claims 1-14, wherein the one or more sulfonic acids comprises dodecyl benzene sulfonic acid.

16. The product of any one of claims 1-3, wherein the one or more polymerization inhibitors is present in an amount of between about 1 ppm to 10000 ppm.

17. The product of any one of claims 1-4, wherein the one or more polymerization retarders is present in an amount of between about 1 ppm to about 10000 ppm.

18. The product of any one of claims 1-17, wherein the one or more sulfonic acids is present in an amount of about 1 ppm to about 1000 ppm.

19. The product of claim 18, wherein the one or more sulfonic acids is present in an amount of about 50 ppm.

20. The product of any one of claims 1-19, wherein the product further comprises an amine, an amine-based polymer, or mixtures thereof.

21. The product of claim 20, wherein the amine comprises diethanolamine (DEA) or diisopropanolamine (DIP A).

22. The product of claim 20, wherein the amine-based polymer comprises a reaction product of formaldehyde with 4-nonylphenol and ethylene diamine.

23. The product of claim 20, wherein the amine, amine-based polymer, or mixture thereof is present in the product in a concentration of 1 ppm to 1000 ppm.

24. The product of claim 23, wherein the amine, amine-based polymer, or mixture thereof is present in a ratio of 1 part amine, amine-based polymer, or mixture thereof to 18 parts sulfonic acid.

25. The product of any one of claims 1-24, wherein the product further comprises tetrapropenyl-butanedioic acid.

26. A method of reducing fouling during the production of a vinyl aromatic monomer comprising: adding to the monomer an effective amount of one or more sulfonic acids in combination with an effective amount of one or more polymerization inhibitors, or an effective amount of one or more polymerization retarders, or mixtures thereof.

27. The method of claim 26, wherein the method comprises adding to the monomer: a first composition comprising an effective amount of one or more sulfonic acids; and a second composition comprising a mixture of an effective amount of one or more polymerization inhibitors and an effective amount of one or more polymerization retarders.

28. The method of claim 26, wherein the method comprises adding to the monomer: a first composition comprising an effective amount of one or more sulfonic acids; a second composition comprising an effective amount of one or more polymerization inhibitors; and a third composition comprising an effective amount of one or more polymerization retarders.

29. The method of claim 26, wherein the method comprises adding to the monomer: a first composition comprising an effective amount of one or more sulfonic acids; and a second composition comprising an effective amount of one or more polymerization retarders.

30. The method of any one of claims 26-28, wherein the one or more polymerization inhibitors comprises one or more phenolic containing inhibitors, one or more hydroxylamines, one or more stable nitroxyl radicals, or combinations thereof.

31. The method of claim 30, wherein the phenolic containing inhibitor is selected from the group consisting of 4-tert-butylcatechol, butylated hydroxy toluene, 2,6-ditertbutylphenol, and combinations thereof.

32. The method of claim 31, wherein the phenolic containing inhibitor is 2,6- ditertbutylphenol .

33. The method of claim 30, wherein the one or more hydroxylamines comprises N,N- bis(2-hydroxypropyl)hydroxylamine (HPHA).

34. The method of claim 30, wherein the one or more stable nitroxyl radicals comprises 4- hydroxy-2,2,6,6-tetramethyl-l-piperidinoxy.

35. The method of claim 30, wherein the one or more polymerization inhibitors comprises HPHA and 4-hydroxy-2,2,6,6-tetramethyl-l-piperidinoxy.

36. The method of any one of claims 26-29, wherein the one or more polymerization retarders comprises dinitro phenolic compounds, quinone methide, quinone methide derivatives, or combinations thereof.

37. The method of claim 36, wherein the dinitro phenolic compound is selected from the group consisting of 2,6-dinitro-p-cresol, 2,4-dinitrophenol, 2,4-dinitro-o-cresol, and 2,4- dinitro-6-sec -butylphenol, and combinations thereof.

38. The method of claim 37, wherein the dinitro phenolic compound is 2,4-dinitro-6-sec- butylphenol.

39. The method of claim 36, wherein the quinone methide derivative is 2,6-di-tert-butyl-4- benzylidene-cyclohexa-2,5-dienone.

40. The method of any one of claims 26-39, wherein the one or more sulfonic acids comprises dodecyl benzene sulfonic acid.

41. The method of any one of claims 26-28, wherein the one or more polymerization inhibitors is present in an amount of between about 1 ppm to 10000 ppm.

42. The method of any one of claims 26-29, wherein the one or more polymerization retarders is present in an amount of between about 1 ppm to about 10000 ppm.

43. The method of any one of claims 26-42, wherein the one or more sulfonic acids is present in an amount of about 1 ppm to about 1000 ppm.

44. The method of claim 43, wherein the one or more sulfonic acids is present in an amount of about 50 ppm.

45. The method of any one of claims 26-44, wherein the method further comprises adding to the monomer an amine, an amine-based polymer, or mixtures thereof.

46. The method of claim 45, wherein the amine comprises diethanolamine (DEA) or diisopropanolamine (DIP A).

47. The method of claim 45, wherein the amine-based polymer comprises a reaction product of formaldehyde with 4-nonylphenol and ethylene diamine.

48. The method of claim 45, wherein the amine, amine-based polymer, or mixture thereof is added in a concentration of 1 ppm to 1000 ppm.

49. The method of claim 45, wherein the amine, amine-based polymer, or mixture thereof is present in a ratio of 1 part amine, amine-based polymer, or mixture thereof to 18 parts sulfonic acid.

50. The method of any one of claims 26-49, wherein the vinyl aromatic monomer is selected from the group consisting of styrene, bromostyrene, divinylbenzene, a-methylstyrene and combinations thereof.

51. The method of any one of claims 26-50, wherein the method further comprises adding tetrapropenyl-butanedioic acid.

52. A method of reducing the corrosivity of the product of any one of claims 1-19, by adding to the product an amine, an amine-based polymer, or mixtures thereof.

53. The method of claim 52, wherein the amine comprises diethanolamine (DEA) or diisopropanolamine (DIP A).

54. The method of claim 52, wherein the amine-based polymer comprises a reaction product of formaldehyde with 4-nonylphenol and ethylene diamine.

55. The method of claim 52, wherein the amine, amine-based polymer, or mixture thereof is added in a concentration of 1 ppm up to an equivalent concentration of sulfonic acid.

56. The method of claim 52, wherein the amine, amine-based polymer, or mixture thereof is present in a ratio of 1 part amine, amine-based polymer, or mixture thereof to 18 parts sulfonic acid.

57. The method of any one of claims 52-56, wherein the method further comprises adding tetrapropenyl-butanedioic acid.

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