Quinone methide and ammonium salt antipolymerant composition and method

Abstract

To provide compositions and methods for inhibiting polymerization of a monomer (e.g., styrene) composition, a quinone methide polymerization retarder and an ammonium salt.SOLUTION: There are described compositions and methods for inhibiting polymerization of a monomer (e.g., styrene) composition, a quinone methide polymerization retarder and an ammonium salt. In a mixture, the ammonium salt improves the efficacy of the quinone methide polymerization retarder and provides greater antipolymerant activity. In turn, the mixture reduces or prevents apparatus fouling and improves the purity of monomer streams.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 913,934, filed October 11, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to compositions comprising a quinone methide and an amine salt, and the use of this combination as a polymerization inhibitor composition to prevent premature polymerization of monomers. [Background technology]

[0003] For example, high-temperature processing of hydrocarbon streams rich in ethylenically unsaturated monomers, such as styrene, isoprene, and butadiene, can be very difficult. In various chemical industrial processes, the use of high temperatures to purify these monomers can lead to undesirable and problematic polymers. These vinyl monomers undergo undesirable polymerization via radical polymerization, especially at high temperatures. Similarly, transportation and storage of hydrocarbon streams containing vinyl species can result in premature polymerization unless polymerization inhibitors are added to the stream. The polymers thus formed can precipitate from solution and foul process equipment. These undesirable polymerization reactions also result in lost production efficiency and the consumption of valuable products. Contaminant removal is required. Physical removal or cleaning of contaminated equipment is often costly. Undesirable polymerization reactions are particularly problematic in compositions containing vinyl aromatic monomers.

[0004] To prevent undesired polymerization reactions, free radical polymerization inhibitors are often added to process streams or stored compositions. However, these compounds are generally consumed very rapidly. For example, if an emergency occurs due to mechanical or processing problems and an inhibitor cannot be added, the previously added inhibitor is rapidly consumed. Undesired polymerization reactions then rapidly recur.

[0005] Examples of polymerization inhibitors known in the art include dialkylhydroxylamines, such as hydroxypropylhydroxylamine (HPHA), and stable nitroxide free radicals. Other inhibitors include N,N'-dialkylphenylenediamines, N,N'-diarylphenylenediamines, and N-aryl-N'-alkylphenylenediamines. Quinone diimide compounds are another class of inhibitors.

[0006] Polymerization inhibitors such as sulfur and dinitrophenol (DNP) compounds, typified by 2,6-dinitrophenol, 2,4-dinitrocresol, and 2-sec-butyl-4,6-dinitrophenol (DNBP), were initially used. However, DNP and sulfur polymerization inhibitors have been shown to be effective against NO X and SO X DNP-based polymerization inhibitors release toxic emissions, making their use questionable. Furthermore, the safety of personnel handling DNP-based polymerization inhibitors is a major concern due to their high toxicity.

[0007] Other types of polymerization inhibitor compounds, often called "retarders," slow the rate of polymerization reactions. However, they are not as effective as polymerization inhibitors, especially stable nitroxide free radicals. However, polymerization retarders are typically not consumed as quickly as polymerization inhibitors, and therefore tend to be more useful in emergency shutdown situations.

[0008] One class of compounds designed to function as a safer alternative to DNP retarders is based on quinone methide chemistry. Quinone methides slow the rate of polymer formation under static conditions, eliminating the need for frequent refeeding to the process stream. However, some quinone methide compounds may not exhibit good stability or may be less effective at inhibiting the rate of polymerization compared to DNP and other NO-based polymerization inhibitors. Examples of quinone methide compounds can be found in U.S. Patents 4,003,800, 5,583,247, and 7,045,647. Summary of the Invention [Problem to be solved by the invention]

[0009] Technical challenges remain in this field related to the efficacy of compounds used to inhibit or slow polymerization reactions, as well as stability and safety concerns. Despite concerns about toxicity, DNP-based polymerization inhibitors remain the most efficient retarders available. Due to safety concerns, there is a need for polymerization inhibitor formulations that are at least as effective as DNP-type retarders but are non-toxic. [Means for solving the problem]

[0010] The present disclosure relates to compositions and methods that include or utilize a quinone methide polymerization retarder and an ammonium salt. The ammonium salt, in various embodiments, improves the effectiveness of the quinone methide polymerization inhibitor to a level comparable to that of nitro- or nitroxide-containing polymerization inhibitors. The compositions and methods can be used to inhibit the polymerization of ethylenically unsaturated monomers, such as styrene and butadiene, in a variety of processes and situations, including the purification, fractionation, separation, compaction, transportation, and storage of various compositions. The use of the compositions of the present invention also reduces contamination of process, transportation, and storage equipment. In turn, polymer contamination of purified monomer products can be significantly reduced, reducing maintenance costs for the equipment used to produce such monomer products.

[0011] In embodiments, the present invention provides a composition comprising a quinone methide and an ammonium salt.

[0012] An exemplary quinone methide is a compound of formula I: [ka] In the formula, R 1 and R 2 is independently selected from C4-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl; R3 and R 4 are independently -H, C1-C18 alkyl, phenyl, substituted phenyl, C5-C12 cycloalkyl, -CN, -COOH, -C=CHR 5 , -C≡CR 5 , -COOR 5 , -COR 5 , -OCOR 5 , -CONHR 5 Selected from R 5 is selected from H, C1-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl, and substituted phenyl.

[0013] In some embodiments, the quinone methide retarder is a compound of formula II: [ka] In the formula, R 1 and R 2 are independently selected from hydrogen, C4-C18 alkyl, C5-C12 cycloalkyl, aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl; R 3 is hydrogen, C1-C18 alkyl, C5-C12 cycloalkyl, C5-C12 It is selected from heterocycloalkyl, aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl.

[0014] In some embodiments, R 1 and R 2 are independently selected from hydrogen, C4-C18 alkyl, or more specifically, are independently selected from t-butyl, t-amyl, t-hexyl, t-octyl, or t-decyl. 3 is selected from aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl, and more particularly is aryl.

[0015] Exemplary ammonium salts include cations of formula III: [ka] In the formula, R 1 , R 2 , R 3 , and R 4 are independently selected from (a) -H, (b) a carbon-containing group, (c) an oxygen-containing group, and (d) an oxygen- and carbon-containing group. Exemplary cations include monoprotonated ammonium cations, diprotonated ammonium cations, triprotonated ammonium cations, and quaternary ammonium cations.

[0016] A quaternary ammonium cation is one in which the nitrogen is 1 , R 2 , R 3 , and R 4 For example, a quaternary ammonium cation is one that is directly bonded to a carbon atom in each of R 1 , R 2 , R 3 , and R 4 may be independently selected from alkyl, aryl, arylalkyl, and alkylaryl.

[0017] Other exemplary ammonium salts include cations of formula IV: [ka] In the formula, R 5 is a monovalent or polyvalent carbon-containing group, y is an integer ranging from 1 to 4, and R 6 , R 7 , and R 8 are independently selected from (a)-(d) as described with respect to Formula I.

[0018] Exemplary ammonium salts include carboxylate groups such as acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, 2-methylbutanoate, pivalate, caproate, 2-methylvalerate, 3-methylvalerate, 4-methylvalerate, 2,2-2,2-dimethylbutanoate, 2-ethylbutanoate, heptanoate, 2-methylcaproate, 3-methylcaproate , 4-methylcaproate, 5-methylcaproate, 2,2-dimethylvalerate, 2-ethylvalerate; caprylate, 2-methylheptanoate, 3-methylheptanoate, 4-methylheptanoate, 5-methylheptanoate, 6-methylheptanoate, 2,2-dimethylcaproate, 2-ethylcaproate, and 2-propylvalerate, and anions including combinations thereof.

[0019] In embodiments, the ammonium salt has the properties of an ionic liquid at room temperature.

[0020] In embodiments, the quinone methide is present in a molar amount greater than the ammonium salt.

[0021] In embodiments, the compositions of the present disclosure are used to inhibit polymerization of monomers in a composition. In embodiments, the compositions of the present disclosure are used in a synthesis, purification, or purification process of a polymerizable monomer. In embodiments, the compositions of the present disclosure are used in the storage or transportation of a polymerizable monomer.

[0022] In an embodiment, the present invention provides a method for inhibiting polymerization of a monomer in a composition. The method includes providing a composition containing a polymerizable monomer or a compound capable of forming a polymerizable monomer, a quinone methide, and an ammonium salt. The composition can be provided by adding the quinone methide and the ammonium salt to the composition simultaneously or at different times. In the composition, polymerization of the polymerizable monomer is inhibited in the presence of the quinone methide and the ammonium salt.

[0023] For the combination of exemplary quinone methides (QMCinn, QMPh) with exemplary ammonium salts (TIPA-2-EH, DIHA-2-EH), and the experimental studies described herein, the combinations provided improved polymerization inhibitor activity over compositions having only the quinone methide, and even over the nitro-containing polymerization inhibitor DNBP. Improvements were observed throughout the testing period of the polymerization inhibitors.

[0024] In embodiments, the polymerizable monomer contains a vinyl or ethylenically unsaturated group or is selected from the group consisting of acrylic acid, acrylonitrile, alkylated styrene, butadiene, chloroprene, divinylbenzene, ethyl acrylate, ethyl methacrylate, isoprene, methacrylic acid, methyl methacrylate, methyl acrylate, α-methylstyrene, methacrylonitrile, styrene, styrene sulfonic acid, vinyl toluene, and vinyl pyridine.

[0025] In embodiments, the method is performed during the purification or processing of one or more components of the composition and / or is performed prior to storage or transport of the second composition. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a graph of the amount of polystyrene polymer formed from a styrene monomer solution in the presence of a quinone methide polymerization retarder (7-cinnamylquinone methide, QMCinn), in combination with an ammonium salt (triisopropanolammonium 2-ethylhexanoate, TIPA-2-EH), and compared to QMCinn and a nitrophenol-based polymerization inhibitor (DNBP) used alone.

[0027] [Figure 2]FIG. 1 is a graph of the amount of polystyrene polymer formed from a styrene monomer solution in the presence of a quinone methide polymerization retarder (7-phenylquinone methide, QMPh) in combination with different ammonium salts (diethylhydroxylammonium 2-ethylhexanoate, DEHA-2-EH), as well as compared to QMPh and DNBP used alone.

[0028] [Figure 3] 1 is a graph of the amount of polystyrene polymer formed from a styrene monomer solution in the presence of quinone methide polymerization retarders QMPh and TIPA 2-EH, and compared to QMPh and a nitrophenol-based polymerization inhibitor (DNBP) used alone. DETAILED DESCRIPTION OF THE INVENTION

[0029] Although this disclosure provides reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Reference to various embodiments does not limit the scope of the claims appended hereto. Moreover, any examples set forth herein are not intended to be limiting, but merely to set forth some of the many possible embodiments of the appended claims.

[0030] Additional advantages and novel features of the present invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by routine experimentation in practicing the invention.

[0031] The present disclosure provides a composition comprising a quinone methide polymerization retarder and an ammonium salt for use in the composition to prevent the undesired formation of polymers. The ammonium salt can improve the polymerization inhibitor effectiveness of the quinone methide polymerization retarder, which in turn can provide better polymerization inhibitor activity when used in a monomer-containing composition. The present disclosure also provides a method of using the quinone methide polymerization retarder and the ammonium salt in a method for inhibiting the polymerization of monomers in a monomer-containing composition, such as a vinyl aromatic monomer-containing composition.

[0032] An embodiment of the present disclosure provides a composition for inhibiting monomer polymerization, comprising a quinone methide polymerization retarder and an ammonium salt. Optionally, the composition can contain one or more other components, such as an organic solvent. Optionally, other polymerization inhibitors, such as nitroxide group-containing polymerization inhibitors, can be used or can be omitted from the composition of the present disclosure.

[0033] The composition containing these components (and any one or more optional components) can be in a desired form, such as a liquid form, a dry form, or a suspension or dispersion. The quinone methide and ammonium salt can be in a desired physical state in the composition, such as a dissolved state, a partially dissolved state, a suspended state, or a dry mixture. The quinone methide and ammonium salt can also be in a desired form in the composition, such as a particulate form. If one or more of the components are in a particulate form, the particles can optionally be described in terms of particle size (e.g., particles of a certain size range) and / or shape. The form of the composition and the state of the components therein can be selected by the selection of the quinone methide and ammonium salt, based on an understanding of the physical properties of each compound. The form of the composition and the state of the components therein can also be affected by the inclusion of one or more optional components, such as a solvent or solvent mixture, or other excipient compounds, such as surfactants, dispersants, etc. The form of the composition and the state of the components therein can also be affected by temperature, and the properties of the composition can be arbitrarily described in the context of a particular temperature (e.g., a storage temperature of 5°C or below, room temperature (25°C), or a temperature used to synthesize and / or process the monomer (e.g., above about 100°C, about 150°C, about 175°C, etc.)).

[0034] In a preferred embodiment, the ammonium salt is in liquid form (e.g., in the form of an "ionic liquid"). Ammonium salts in liquid form can be measured over a certain temperature range. Ammonium salts can be described as liquid at a certain temperature, such as about room temperature (about 25°C). The physical properties of ammonium salts are typically determined when they are in pure or substantially pure form.

[0035] In embodiments, the ammonium salt may be in liquid form at both the storage temperature and the operating temperature. The "storage temperature" may range from about 5°C to about 40°C, or from about 15°C to about 30°C. A typical storage temperature is room temperature. The "operating temperature" may be one or more temperatures commonly used to purify or process monomer streams, such as greater than 50°C, greater than 80°C, for example, from about 100°C to about 400°C, from about 100°C to about 200°C, or from about 100°C to about 150°C.

[0036] In embodiments, the ammonium salt may be in solid form at storage temperatures and liquid at operating temperatures. For example, the ammonium salt may be in solid form at temperatures below about 50°C, below about 40°C, below about 30°C, below about 20°C, or below about 10°C, and may be liquid at temperatures above about 50°C, above about 80°C, or above about 100°C. For example, in some embodiments, the ammonium salt may have a melting point in the range of about 10°C to about 100°C, or about 10°C to about 80°C.

[0037] Eike, DM, et al. (Green Chemistry, 5:323-328, 2003) describe a quantitative structure-property relationship (QSPR) method for correlating and predicting the melting points of organic salts based on ammonium cations.

[0038] As discussed herein, compositions comprising a quinone methide and an ammonium salt can optionally include other ingredients in the composition (e.g., described in terms of a composition "comprising" a quinone methide and an ammonium salt). For example, such compositions can include other ingredients such as a solvent, surfactant, dispersant, etc. If an optional ingredient is present in the composition, it can be described in terms of its amount by weight relative to one or both of the quinone methide and ammonium salt in the composition. The optional ingredient can be present in an amount greater or less by weight than either the quinone methide or the ammonium salt, or the total amount of the quinone methide and ammonium salt.

[0039] Compositions containing quinone methides and ammonium salts, and any one or more optional components, can be described in terms of the relative amounts of the components by weight. In a composition in which a particular component is the "predominant" component, that component is greater by weight than any other component. For example, in a composition in which components A, B, and C are present at 48% (by weight), 47% (by weight), and 5% (by weight), component A is the predominant component in the composition. When component A accounts for more than 50% (by weight) of the composition, it constitutes the majority of the composition.

[0040] As used herein, the terms "optional" or "optionally" mean that the subsequently described thing (e.g., compound), event (e.g., processing step), or circumstance can occur, but need not occur, and that the description includes cases where the thing, event, or circumstance occurs as well as cases where it does not occur.

[0041] The compositions of the present disclosure can include the listed compounds and, optionally, can include other components in the composition, but in very small amounts (e.g., described with respect to a composition "consisting essentially of" the listed components). For example, such compositions can include one or more other components, but not in amounts greater than about 1% (by weight), about 0.5% (by weight), or about 1% (by weight) of the total composition. A composition consisting essentially of a quinone methide and an ammonium salt (e.g., dissolved in a solvent) can optionally include one or more other components, but in amounts less than about 1% (by weight) of the total composition. In a composition "consisting of" the listed components, no other components are present in measurable amounts other than the listed components.

[0042] As used herein, for example, when describing embodiments of the present disclosure, the terms "substantially" and "essentially consisting of" modify the type or amount, property, measurable amount, manner, location, value, or range of a component in a composition refer to variations that do not affect the generally recited composition, property, amount, manner, location, value, or range in a manner that invalidates the intended composition, property, amount, manner, location, value, or range. Examples of intended properties include, by way of non-limiting example only, dispersibility, stability, speed, solubility, etc., and intended values ​​include the weight of added components, the concentration of added components, etc. Effects on modified processes include effects caused by variations in the type or amount of materials used in the process, variations in machine settings, the effect of ambient conditions on the process, etc., where the manner or degree of the effect does not invalidate one or more intended properties or results, and similar approximation considerations. When modified by the terms "substantially" or "essentially consisting of," the claims appended hereto include equivalents of these types and amounts of materials.

[0043] As used herein, for example, when describing embodiments of the present disclosure, the term "about" when used to modify the amount, concentration, volume, process temperature, process time, yield, flow rate, pressure, and similar values ​​and ranges of components in a composition refers to variations in numerical quantities that may arise, for example, from typical measuring and handling procedures used to make a compound, composition, concentrate, or use formulation; from accidental errors in these procedures; from differences in the manufacture, source, or purity of starting materials or components used to carry out the method; and from similar approximation considerations. The term "about" also encompasses amounts that differ due to degradation of a formulation having a particular initial concentration or mixture, and amounts that differ due to mixing or processing a formulation having a particular initial concentration or mixture. When modified by the term "about," the appended claims include equivalents of these quantities. Furthermore, when "about" is used to describe any range of values, unless otherwise limited by context, a statement such as "about 1 to 5" means "1 to 5," "about 1 to about 5," "1 to about 5," and "about 1 to 5."

[0044] The compositions and methods of the present disclosure include or use polymerization retarders having quinone methide chemistry. Quinone methides are chemically characterized by a cyclohexadiene group (or its derivatives), a carbonyl group, and an exocyclic methylene group. Monocyclic quinone methides are well known as polymerization retarders, although polycyclic (bicyclic, tricyclic, etc.) quinone methide compounds are also known.

[0045] In some embodiments, the quinone methide retarder is a compound of Formula I: [ka] In the formula, R 1 and R 2 is independently selected from C4-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl; R 3 and R 4are independently -H, C1-C18 alkyl, phenyl, substituted phenyl, C5-C12 cycloalkyl, -CN, -COOH, -C=CHR 5 , -C≡CR 5 , -COOR 5 , -COR 5 , -OCOR 5 , -CONHR 5 Selected from R 5 is selected from H, C1-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl, and substituted phenyl. 1 and R 2 is independently selected from C4 to C18 alkyl, preferably C4 to C6 straight or branched alkyl, such as tert-butyl.

[0046] Exemplary quinone methide retarders include 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone, 2,6-di-tert-butyl-4-(4-nitrobenzylidene)-cyclohexa-2,5-dienone, 2,6-di-tert-butyl-3-(4-nitrobenzylidene)-cyclohexa-2,5-dienone, 2,6-di-tert-butyl-4-(4-cyanobenzylidene)-cyclohexa-2,5-dienone, 2,6-di-tert-butyl-4-(4-methoxybenzylidene)-cyclohexa-2,5-dienone, and 2,6-di-tert-butyl-4-(3,5-di-tert-butyl-4-hydroxybenzylidene)-cyclohexa-2,5-dienone. See, for example, U.S. Patent No. 5,616,774 and U.S. Application Publication No. 2006 / 0163539.

[0047] An exemplary quinone methide 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone has the following structure: [ka] It is referred to herein as "7-phenylquinone methide" and "QMPh" or "PhQM."

[0048] In some embodiments, the quinone methide retarder is a compound of formula II: [ka] In the formula, R 1 and R 2 are independently selected from hydrogen, C4-C18 alkyl, C5-C12 cycloalkyl, aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl; R 3 is selected from hydrogen, C1-C18 alkyl, C5-C12 cycloalkyl, C5-C12 heterocycloalkyl, aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl.

[0049] In some embodiments, R 1 and R 2 are independently selected from hydrogen, C4-C18 alkyl, or more specifically, are independently selected from t-butyl, t-amyl, t-hexyl, t-octyl, or t-decyl. 3 is selected from aryl, C7-C15 arylalkyl, and C7-C15 alkylaryl, and more particularly is aryl.

[0050] Exemplary quinone methides of Formula II include 2,6-di-tert-butyl-4-(3-phenylallylidene)cyclohexa-2,5-dienone (referred to herein as "7-cinnamylquinone methide" and "7-Cinn-QM"), which is described in U.S. Pat. No. 9,957,209 (Masere and Colorado), the disclosure of which is incorporated herein by reference. 7-Cinn-QM has the following structure: [ka]

[0051] The ammonium salts of the present disclosure can provide improvements in the effectiveness of quinone methide polymerization retarders when used in combination (compared to compositions that do not contain ammonium salts). Without being bound to a particular theory or mechanism, the ammonium salts may enhance the functionality of the quinone methide retarders. For example, the ammonium salts may enhance the ability of the quinone methide retarder to retard polymerization or may enhance the functional life of the quinone methide retarder, thereby allowing it to more effectively retard polymerization over a period of time.

[0052] The compositions and methods of the present disclosure include or use ammonium salts.Ammonium salts include ammonium-containing cations and anions.Ammonium-containing cations can be symmetrical, for example, when the four R groups attached to the positively charged nitrogen are the same, or asymmetrical, for example, when there is one or more differences between the four R groups attached to the positively charged nitrogen.In many embodiments, ammonium-containing cations are protonated, and one or more of the four R groups attached to the nitrogen of the ammonium salt are hydrogen.Exemplary ammonium cations include monoprotonated ammonium cations, diprotonated ammonium cations, and triprotonated ammonium cations.

[0053] The anion of the ammonium salt can be an organic or inorganic anion. In some embodiments, the anion is derived from an acidic compound, such as from a carboxylic acid, a sulfonic acid, a nitric acid, a phosphonic acid, or a combination thereof. Thus, exemplary anions include carboxylate, sulfonate, nitrate, phosphate, etc.

[0054] In embodiments, the ammonium salt comprises a cation of formula III. [ka]

[0055] In Formula III, R 1 , R 2, R 3 , and R 4 are independently selected from (a) —H, (b) a carbon-containing group, (c) an oxygen-containing group, and (d) an oxygen- and carbon-containing group.

[0056] Other exemplary ammonium salts include the cation of formula IV: [ka] In the formula, R 5 is a monovalent or polyvalent carbon-containing group, y is an integer ranging from 1 to 4, and R 6 , R 7 , and R 8 is independently selected from (a) through (d) as described.

[0057] In certain embodiments of Formula III, R 1 , R 2 , R 3 , and R 4 At least three of the In certain embodiments of Formula IV, R 6 , R 7 , and R 8 At least two of (b) through (d) are any one or combination of (b) through (d). In embodiments of Formula III or IV, (b) the carbon-containing group can be composed of carbon, oxygen, and hydrogen; (c) the oxygen-containing group can be composed of oxygen and hydrogen; and (d) the oxygen- and carbon-containing group can be composed of carbon, oxygen, and hydrogen, or any combination of (b) through (d). In compounds of Formula III and IV consisting of certain atoms, no other atom types are present in the group other than those listed. In embodiments having a group consisting of certain atoms, the cation of the ammonium salt can have (a) a total amount of carbon atoms ranging from 0 to 18, 1 to 12, or 2 to 10; (b) a total amount of oxygen atoms ranging from 0 to 6, 1 to 4, or 1 to 3; (c) a total amount of hydrogen atoms ranging from 4 to 40, 6 to 30, or 8 to 24; or any combination of (a) through (c).

[0058] In other embodiments, the R groups of Formulas III and IV can include the listed atoms or chemistries, and optionally, can include other atoms or chemistries. Exemplary groups that include oxygen atoms can include chemistries such as hydroxyl, carbonyl, ester, and ether. In embodiments, the R groups of Formula III can include chemistries such as hydroxyl, carbonyl, ester, and ether. 1 , R 2 , R 3 , and R 4 or R of formula IV 6 , R 7 , and R 8 In embodiments, one or more of R in Formula III has one oxygen-containing group selected from hydroxyl, carbonyl, ester, and ether. 1 , R 2 , R 3 , and R 4 one or more of the R of formula IV has two or three oxygen-containing groups, or 6 , R 7 , and R 8 has one or two oxygen-containing groups selected from hydroxyl, carbonyl, ester, and ether, or a combination thereof.

[0059] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8are independently selected from oxygen- and carbon-containing groups that are linear or branched C1-C18 hydroxyalkyl or C6-C18 hydroxyaryl groups, linear or branched C1-C12 hydroxyalkyl or C6-C12 hydroxyaryl groups, linear or branched C1-C8 hydroxyalkyl or C6-C8 hydroxyaryl groups, or linear or branched C1-C6 hydroxyalkyl or C6-C6 hydroxyaryl groups. Exemplary hydroxyalkyl groups include hydroxymethyl, 1- or 2-hydroxyethyl, 1-, 2-, or 3-hydroxypropyl, 2-hydroxyisopropyl, 1-, 2-, 3-, or 4-hydroxybutyl, and 1-, 2-, or 3-hydroxyisobutyl. An exemplary hydroxyaryl group is 2-hydroxyphenyl.

[0060] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8 one, two, or three of the groups have an oxygen- and carbon-containing group of formula VIII; [ka] In the formula, R 15 , R 16 , R 17 , R 18 , and R 19 are independently H, C1 to C 18 Alkyl, aryl, alkylaryl, arylalkyl, and -OR 20 Selected from OR 20 is R 15 ~R 19 and Formula VIII has the same meaning as any one of the groups represented by at least one -OR 20 In some embodiments, one -OR 20 group, or R 16 and R17 are divalent hydrocarbon-containing groups that combine together to form a cyclic alkyl or aryl group, and y is an integer ranging from 1 to 3.

[0061] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8 one, two, or three of the groups have an oxygen- and carbon-containing group of formula V; [ka] In the formula, R 10 , R 11 , R 12 , R 13 , and R 14 are independently H, C1 to C 18 It is selected from alkyl, aryl, alkylaryl, and arylalkyl.

[0062] Some exemplary cations of Formula VIII include R 16 and R 17 are linked together to form a cyclic alkyl or aryl group, such as N,N,N-tris(2-hydroxyphenyl)ammonium, and N,N-bis(2-hydroxyphenyl)hydroxylammonium.

[0063] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8wherein one, two, or three of the groups are independently selected from a carbon-containing group that is a straight-chain or branched C1-C12 alkyl group, a straight-chain or branched C1-C8 alkyl group, or a straight-chain or branched C1-C6 alkyl group. Exemplary alkyl groups include: Methyl, ethyl, Propyl, isopropyl, Butyl, isobutyl, sec-butyl, tert-butyl, Pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, cyclohexyl, 1-, 2-, and 3-methylbutyl, 1,1-, 1,2-, or 2,2-dimethylpropyl, 1-ethylpropyl, 1-, 2-, 3-, or 4-methylpentyl, 1,1-, 1,2-, 1,3-, 2,2-, 2,3-, or 3,3-dimethylbutyl, 1- or 2-ethylbutyl, 1-ethyl-1-methylpropyl, and 1,1,2- or 1,2,2-trimethylpropyl; heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 4,4-dimethylpentyl, cycloheptyl, 1-methylcyclohexyl, and 2-methylcyclohexyl, octyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 5-ethylhexyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3-ethyl-2-methylpentyl, 3-ethyl-3-methylpentyl, 2,2,3-trimethylpentyl, 2,2,4-trimethylpentyl, 2,3,3-trimethylpentyl, 2,3,4-trimethylpentyl, and 2,2,3,3-tetramethylbutyl; and Nonyl, decyl, undecyl, and dodecyl.

[0064] In some embodiments, R of Formula III 1 , R 2 , R 3 , and R 4 or R of formula IV 6 , R 7 , and R 8 are independently selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0065] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8 One, two, or three of the groups are hydroxyl.

[0066] In some embodiments, in the ammonium salt cation of Formula III, R 1 , R 2 , R 3 , and R 4 One of the groups is hydroxyl and R 1 , R 2 , R 3 , and R 4 In some embodiments, in the ammonium salt cation of formula IV, two or three of R 6 , R 7 , and R 8 One of the groups is hydroxyl and R 6 , R 7 , and R 8wherein one or two of the groups are a straight-chain or branched C1-C6 hydroxyalkyl group, or a straight-chain or branched C1-C6 alkyl group or an aryl group. Exemplary hydroxyalkyl groups include hydroxymethyl, 1- or 2-hydroxyethyl, 1-, 2-, or 3-hydroxypropyl, 2-hydroxyisopropyl, 1-, 2-, 3-, or 4-hydroxybutyl, and 1-, 2-, or 3-hydroxyisobutyl, or a straight-chain or branched C1-C6 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, or tert-butyl.

[0067] Some exemplary cations of ammonium salts having a hydroxyl group and two hydroxyalkyl groups include, but are not limited to, di(hydroxyethyl)-hydroxylammonium and di(hydroxypropyl)-hydroxylammonium, or those having a hydroxyl group and two hydroxyaryl groups include N,N-bis(2-hydroxyphenyl)hydroxylammonium, N,N-bis(4-hydroxyphenyl)hydroxylammonium, which are shown below. An exemplary cation of an ammonium salt having a hydroxylated alkylaryl group is di(2-hydroxy,2-phenylethyl)-hydroxylammonium, shown below. [ka]

[0068] Some exemplary cations of ammonium salts having a hydroxyl group and two alkyl groups include, but are not limited to, diethylhydroxylamine and dipropylhydroxylamine. Some exemplary cations of ammonium salts having a hydroxyl group and two aryl groups include, but are not limited to, N,N-dibenzylhydroxylammonium. The structure is shown below. [ka]

[0069] In some embodiments, in the ammonium salt, R of Formula III 1 , R 2 , R 3 , and R 4 or one, two, three, or four of R of formula IV 6 , R 7 , and R 8 One, two, or three of the groups are hydroxyl.

[0070] In some embodiments of Formula III, the oxygen- and carbon-containing group is selected from the group consisting of 2-benzoxazolyl, adipyl, glutaryl, succinyl, malonyl, acetyl, acrylyl, methacrylyl, caproyl, benzoyl, phthaloyl, terephthaloyl, carbethoxy, carbonyl, and formyl. In some embodiments of Formula III, the carbon-containing group is a nitrogen- and carbon-containing group, such as selected from the group consisting of 1,3,5-sym-triazinyl, 2-benzimidazolyl, 2-pyridyl, and 2-pyrazinyl. In some embodiments of Formula III, the carbon- and oxygen-containing group is a nitrogen-, oxygen-, and carbon-containing group, such as selected from the group consisting of 2-pyrimidinyl and aminocarbonyl. In some embodiments of Formula III, the carbon-containing group is an oxygen-, sulfur-, and carbon-containing group, such as 3-mercaptopropionyl.

[0071] In some embodiments, the ammonium salt comprises a cation of formula IV, as described herein: [ka] More specifically, a cation of formula VI: [ka] In the formula, R 6 , R 7 , and R 8is independently selected from (a) —H, (b) a carbon-containing group, (c) an oxygen-containing group, and (d) an oxygen- and carbon-containing group. 6 , R 7 , and R 8 At least one of the groups is a linear or branched C1 to C12 alkyl group, an aryl group, or a C1 to C12 arylalkyl group.

[0072] Some exemplary cations of phenylenediammonium salts include N,N'-di-sec-butylphenylenediammonium, N-sec-butyl-N'-phenylphenylenediammonium, N,N'-di-phenylphenylenediammonium, N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediammonium, and N-1,4-dimethylpentyl-N'-phenyl-p-phenylenediammonium, which are shown below. [ka]

[0073] The cation of the ammonium salt can be optionally described with reference to the number and type of atoms in the cation. In embodiments, the cation of the ammonium salt has (a) nitrogen atoms in an amount ranging from 1 to 4, or preferably 1 or 2, (b) carbon atoms in an amount ranging from 0 to 18, 1 to 12, or 2 to 10, (c) oxygen atoms in an amount ranging from 0 to 6, 1 to 4, or 1 to 3, (d) hydrogen atoms in an amount ranging from 4 to 40, 6 to 30, or 8 to 24, or any combination of (a)-(d).

[0074] In some preferred embodiments, the cation of the ammonium salt has (a) 1 or 2 nitrogen atoms, (b) an amount of carbon atoms ranging from 6 to 12, (c) an amount of oxygen atoms ranging from 2 to 5, and (d) an amount of hydrogen atoms ranging from 16 to 28. In some preferred embodiments, the cation of the ammonium salt has (a) 1 or 2 nitrogen atoms, and (b) an amount of carbon atoms ranging from 8 to 10, (c) an amount of oxygen atoms ranging from 3 to 4, and (d) an amount of hydrogen atoms ranging from 19 to 25.

[0075] In other preferred embodiments, the cation of the ammonium salt has a nitrogen atom and (a) an amount of carbon atoms ranging from 2 to 6; (b) 1, 2, or 0 oxygen atoms; and (c) an amount of hydrogen atoms ranging from 8 to 16. In some preferred embodiments, the cation of the ammonium salt has a nitrogen atom and (a) an amount of carbon atoms ranging from 3 to 5, (b) 1 oxygen atom, and (c) an amount of hydrogen atoms ranging from 10 to 14.

[0076] In a preferred embodiment of Formula III, R 1 , R 2 , R 3 , and R 4 One or two of the is —H, and R in formula IV 6 , R 7 , and R 8 One or two of the is -H.

[0077] The ammonium salts may optionally be based on a mixture of different cations, such as a mixture of different cations according to the general formulas III and / or IV described herein. Thus, in a composition or method using a quinone methide polymerization retarder, there may be two or more different cation species of formula III and / or IV that form two or more different ammonium salts.

[0078] In embodiments, the ammonium salt comprises an anion comprising a carboxylate group, a sulfonate group, a phosphonate group, a nitrate group, a nitrite group, or a combination thereof. Other anions of the ammonium salt include aldonates, aldates, urosonates, and carboxylic acid uronates of sugar acids. Some preferred anions include a carboxylate group, such as that found in gluconate. Another exemplary anion is ascorbate.

[0079] The cation of the ammonium salt can be an organic anion containing a desired number of carbon atoms. In embodiments, the organic anion has a number of carbon atoms ranging from 2 to 18, 3 to 12, or 4 to 10. The organic anion can also have a desired number of oxygen atoms, such as 2, 3, or 4.

[0080] In embodiments, the organic anion of the ammonium salt is acetate (ethanoate); Propionate (propanoate); butyrate (butanoate), isobutyrate (2-methylpropanoate); Valerate (pentanoate), isovalerate (3-methylbutanoate), 2-methylbutanoate, pivalate (2,2-dimethylpropanoate); Caproate (hexanoate), 2-methylvalerate, 3-methylvalerate, 4-methylvalerate, 2,2-2,2-dimethylbutanoate, 2-ethylbutanoate; Heptanoate (enanthate), 2-methylcaproate, 3-methylcaproate, 4-methylcaproate, 5-methylcaproate, 2,2-dimethylvalerate, 2-ethylvalerate; The anion may be a carboxylate-containing anion selected from the group consisting of caprylate (octanoate), 2-methylheptanoate, 3-methylheptanoate, 4-methylheptanoate, 5-methylheptanoate, 6-methylheptanoate, 2,2-dimethylcaproate, 2-ethylcaproate (2-ethylhexanoate), and 2-propylvalerate.

[0081] The ammonium salts may optionally be based on a mixture of different anions, such as a mixture of different carboxylate-containing anions as described herein. Thus, in a composition or method using a quinone methide polymerization retarder, there may be two or more different anionic species that form two or more different ammonium salts.

[0082] The ammonium salts can optionally be described with reference to molar mass, such as molar mass limits or molar mass ranges. The ammonium salts can be of any desired molecular weight, such as suitable for use with quinone methides in polymerization inhibitor compositions or methods.

[0083] In embodiments, the ammonium salt has a molar mass of less than about 1000 g / mol, less than 900 g / mol, less than 800 g / mol, less than 700 g / mol, less than 600 g / mol, less than 500 g / mol, less than 450 g / mol, less than 400 g / mol, less than 375 g / mol, or less than 350 g / mol. In embodiments, the ammonium salt has a molar mass of about 120 g / mol or more, about 130 g / mol or more, about 140 g / mol or more, or about 150 g / mol or more. The molar mass range of the present disclosure can be based on any two of the lower and upper limits described herein (e.g., a range of about 120 g / mol to about 1000 g / mol).

[0084] In other embodiments, the ammonium salt can have a molar mass greater than about 1000 g / mol.For example, the high molecular weight ammonium salt can be in the form of a polymeric ammonium salt.Polymeric ammonium salts, including polymeric quaternary ammonium salts, are known in the art.See, for example, U.S. Patent Nos. 2,595,225, 4,247,476, and U.S. Patent Application Publication No. 2006 / 0062753.

[0085] In some embodiments, the ammonium salt is formed by reacting an amine reactant compound with an acid. The reaction results in protonation of the nitrogen atom of the amine reactant compound to form an amine cation and a deprotonated anion of the acid. The reaction of the amine reactant compound with the acid is carried out in a solvent or neat (i.e., using only the amine compound and the acid).

[0086] In some embodiments, the solvent used in the reaction of the amine compound with the acid includes a polar aprotic solvent. Exemplary polar aprotic solvents include ethyl acetate, dichloromethane (DCM), tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, and hexamethylphosphoric triamide (HMPT).

[0087] Exemplary amine reactant compounds have formula VII: NR 9 R 10 R 11 wherein R 9 , R 10 , and R 11 are independently selected from (a) a carbon-containing group, (b) an oxygen-containing group, and (c) an oxygen- and carbon-containing group. In embodiments, (a) the carbon-containing group can be composed of carbon, oxygen, and hydrogen; (b) the oxygen-containing group can be composed of oxygen and hydrogen; and (c) the oxygen- and carbon-containing group can be composed of carbon, oxygen, and hydrogen, or any combination of (a)-(c). Exemplary groups containing oxygen atoms can include chemistries such as hydroxyl, carbonyl, ester, and ether. In embodiments, R 9 , R 10 , and R 11 In embodiments, one or more of R has one oxygen-containing group selected from hydroxyl, carbonyl, ester, and ether. 9 , R 10 , and R 11 One or more of have two or three oxygen-containing groups selected from hydroxyl, carbonyl, ester, and ether, or combinations thereof.

[0088] In some embodiments, in the amine reactant compound, R 9 , R 10 , and R 11wherein one, two, or three are independently selected from oxygen and carbon-containing groups that are straight-chain or branched C1-C12 alkoxy groups, straight-chain or branched C1-C8 alkoxy groups, or straight-chain or branched C1-C6 alkoxy groups. Exemplary alkoxy groups, such as methoxy, ethoxy, isopropoxy, and the like, are represented by R in Formula III. 1 , R 2 , R 3 , and R 4 are described with reference to the group R 9 , R 10 , and R 11 may be used for any one or more of the following:

[0089] In some embodiments, in the amine reactant compound, R 9 , R 10 , and R 11 wherein one, two, or three of the carbon-containing groups are independently selected from a straight-chain or branched C1-C12 alkyl group, a straight-chain or branched C1-C8 alkyl group, or a straight-chain or branched C1-C6 alkoxy group. Exemplary alkyl groups, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, and the like, are represented by R in Formula III. 1 , R 2 , R 3 , and R 4 The R 9 , R 10 , and R 11 may be used for any one or more of the following:

[0090] In some embodiments, in the amine reactant compound, R 9 , R 10 , and R 11 One, two, or three of the groups are hydroxyl (-OH).

[0091] Exemplary amine reactant compounds include trialkanolamines (trisalkanolamines), such as triethanolamine (TEA), triisopropanolamine (TIPA), tributanolamine, N,N-bis(2-hydroxyethyl)-N-(2-hydroxypropyl)amine (DEIPA), N,N-bis(2-hydroxypropyl)-N-(hydroxyethyl)amine (EDIPA), tris(2-hydroxybutyl)amine, hydroxyethyldi(hydroxypropyl)amine, hydroxypropyldi(hydroxyethyl)amine, tri(hydroxypropyl)amine, hydroxyethyldi(hydroxy-n-butyl)amine, hydroxybutyldi(hydroxypropyl)amine, and combinations thereof.

[0092] Other exemplary amine reactant compounds include dialkanolalkylamines (monoalkyldialkanolamines), such as N,N-bis(2-hydroxyethyl)ethylamine, methyldiethanolamine, methyldiisopropanolamine (MDIPA), N-propyldiethanolamine, N-butyldiethanolamine, and N-methyldipropanolamine.

[0093] Other exemplary amine reactant compounds include dialkylalkanolamines (monoalkanoldialkylamines), such as N,N-diethylisopropanolamine (diethylamino-propanol), N,N-diethylethanolamine (diethylaminoethanol), N-(2-hydroxyethyl)dimethylamine (dimethylethanolamine), and dimethylpropanolamine.

[0094] Other exemplary amine reactant compounds include dialkylhydroxylamines such as dimethylhydroxylamine, N,N-diethylhydroxylamine, dipropylhydroxylamine, N,N-diisopropylhydroxylamine, N,N-dibutylhydroxylamine, N,N-diiso-butylhydroxylamine dipentylhydroxylamine, N,N-dihexylhydroxylamine, and N,N-di(4-methylpentyl)hydroxylamine.

[0095] Other exemplary amine reactant compounds include dialkanol hydroxyls Amines such as diethanolhydroxylamine are included.

[0096] For the preparation of compounds containing the cation of Formula IV, exemplary amine reactant compounds (which can be used, for example, to make phenylenediammonium-based compounds) include alkyl and / or aryl derivatives of ortho-phenylenediamine and para-phenylenediamine compounds, such as N,N'-dimethyl-o-phenylenediamine, N,N'-dimethyl-p-phenylenediamine, N,N'-diethyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine; N-methyl-N'-phenyl-p-phenylenediamine, N-ethyl-N'-phenyl-p-phenylenediamine, N-phenyl-N'-propyl-p-phenylenediamine, N-butyl- N-phenyl-p-phenylenediamine, N-phenyl-N'-sec-butyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-isobutyl-N'-phenyl-p-phenylenediamine, N-phenyl-N'-tert-butyl-p-phenylenediamine, N-phenyl-N'-n-pentyl-p-phenylenediamine, N-phenyl-N'-n-hexyl-p-phenylenediamine, N-(1-methylhexyl)-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine.

[0097] Ammonium salts can be prepared by reacting an amine reactant compound with an organic acid, such as a monofunctional carboxylic acid. Exemplary monofunctional carboxylic acids include acetic acid, propionic acid (propanoate); butyric acid, isobutyric acid; valeric acid, isovaleric acid, 2-methylbutanoic acid, pivalic acid; capric acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-2,2-dimethylbutanoic acid, 2-ethylbutanoic acid; heptanoic acid, 2-methylcaproic acid, 3-methylcaproic acid, 4-methylcaproic acid, 5-methylcaproic acid, 2,2-dimethylvaleric acid, 2-ethylvaleric acid; caprylic acid, 2-methylheptanoic acid, 3-methylheptanoic acid, 4-methylheptanoic acid, 5-methylheptanoic acid, and 6-methylheptanoic acid. Other acids that can be reacted with the amine reactant compound include diacids (bifunctional acids) as described herein.

[0098] The ammonium salts can be formed by reacting an amine reactant compound and a monofunctional acid in equimolar or nearly equimolar amounts. Alternatively, if the acid is a difunctional acid, such as a dicarboxylic acid, the amine reactant can be reacted with a diacid in a 2:1 molar ratio. Exemplary diacids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, suberic acid, azelaic acid, and sebacic acid.

[0099] In some embodiments, the ammonium salt is formed by reacting an amine reactant with an acid in the presence of a solvent or solvent mixture. Solvents that can be used to react an amine compound with an acid include polar aprotic solvents. Exemplary polar aprotic solvents include ethyl acetate, dichloromethane (DCM), tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, and hexamethylphosphoric triamide (HMPT), as well as combinations thereof. Other solvents that can be used to react an amine compound with an acid include aprotic solvents such as aprotic hydrocarbon-based solvents. Exemplary nonpolar aprotic solvents include toluene, cyclohexane, hexane, heptane, xylene, and carbon tetrachloride.

[0100] The amine reactant compound and the acid can be present in the solvent at any desired concentration, which is selected to optimize the reaction of the two components. In an exemplary embodiment, the amine reactant compound and the acid are present together in a weight amount of the solvent-based reaction composition ranging from about 5% (by weight) to about 50% (by weight), or from about 15% (by weight) to about 40% (by weight). The reaction can be carried out at a desired temperature with stirring, such as facilitated by using a magnetic stirrer.

[0101] After the desired reaction period and formation of the ammonium salt, the reaction composition may exhibit an increase in viscosity. The solvent can then be removed using low pressure (e.g., by vacuum), optionally with heat. Depending on the type of amine reactant compound and acid used, after solvent removal, the ammonium salt may have the properties of a solid or an (ionic) liquid.

[0102] In embodiments, the ammonium salt may be in the form of an ionic liquid at room temperature or at temperatures between room temperature and the temperature used in combination with the quinone method to inhibit polymerization of the monomer in the monomer-containing composition. In embodiments, the ammonium salts of the present disclosure are expected to have very high boiling points and therefore remain in a liquid state at high temperature conditions (e.g., above 300°C or above 400°C) during monomer processing. In some cases, the determination of whether an ammonium salt is an ionic liquid is determined at room temperature (about 25°C).

[0103] The present disclosure also provides a composition comprising a quinone methide and an ammonium salt.

[0104] In some embodiments, the quinone methide polymerization retarder and the ammonium salt (including one or more optional components) are present in a composition comprising a solvent or a combination of solvents. The solvent or combination of solvents can be selected so that one or more of the quinone methide polymerization retarder and the ammonium salt are soluble in the solvent or combination of solvents. If the ammonium salt is a liquid at ambient conditions, a miscible solvent can be selected. In embodiments, if the ammonium salt is a liquid, it can also function as a solvent and can be used to at least partially solvate the quinone methide polymerization retarder.

[0105] Useful solvents include any solvent in which the combination of quinone methide polymerization retarder and ammonium salt (and optionally inhibitor) is soluble or can be stably suspended in. In some embodiments, the solvent or solvent combination can be selected from water-soluble or water-miscible solvents, such as glycol-based solvents, and hydrophobic or hydrocarbon solvents, such as aromatic solvents, paraffinic solvents, or a mixture of both.

[0106] Exemplary glycol solvents include, but are not limited to, C1-C8 glycols such as ethylene glycol, propylene glycol, diethylene glycol, and triethylene glycol, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycols, ethers of such glycols such as dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and low molecular weight polypropylene glycols, and combinations thereof. Commercially available solvents such as Butyl Carbitol and Butyl CELLOSOLVE™, which contain primarily Butyl CARBITOL™, primarily ethylene glycol monobutyl ether, can be used and are available from DOW.

[0107] Other exemplary hydrophobic or hydrocarbon solvents include heavy aromatic naphtha, toluene, ethylbenzene, isomeric hexanes, benzene, xylenes such as ortho-xylene, para-xylene, or meta-xylene, and mixtures of two or more thereof.

[0108] In some embodiments, the solvent is selected from glycol and aromatic naphtha and combinations thereof.

[0109] The amount of quinone methide polymerization retarder and ammonium salt (including one or more optional components, such as polymerization inhibitors) in the solvent or combination of solvents can be described in one or more ways, for example, by the percent solids (by weight) of these components in the composition or by the molar amounts in the composition.

[0110] The compositions of the present disclosure can be made using any desired method, for example, a preparation of the quinone methide polymerization retarder and ammonium salt (including one or more optional ingredients), and optionally a solvent, such as a commercially available preparation, can be obtained by the user and then combined and stored, or alternatively, can be added together, for example, at some point in the usage procedure.

[0111] When used in combination with a quinone methide retarder, the ammonium salt can improve the retarder's effectiveness as a polymerization inhibitor. For example, the use of an ammonium salt in combination with a quinone methide retarder can inhibit the polymerization of the monomer to a greater extent than the use of the retarder alone or the ammonium salt alone.

[0112] The amounts of quinone methide polymerization retarder and ammonium salt in the composition can be described in various ways, such as by the weight percent (% wt) of each component in the composition or by the molar amounts of the compounds. The compounds can also be described in terms of their weight ratios in the composition or in terms of their relative amounts to one another.

[0113] In some embodiments, the amount of quinone methide polymerization retarder (measured as weight percent or molar amount) in the composition is greater than the amount of ammonium salt. For example, the amount of quinone methide polymerization retarder can be about 1.5 times greater, about 2 times greater, about 2.5 times greater, about 3 times greater, about 3.5 times greater, about 4 times greater, about 4.5 times greater, or about 5 times greater than the amount of ammonium salt (weight percent or molar amount) in the composition. As another example, the amount of quinone methide polymerization retarder can be about 1.5 times to about 1000 times, 1.5 times to about 250 times, 1.5 times to about 100 times, or about 1.5 times to about 50 times, or about 1.5 times to about 25 times, or about 1.5 times to about 15 times, or more, greater than the amount of ammonium salt (weight percent or molar amount) in the composition.

[0114] The amounts of quinone methide and ammonium salt in the composition can optionally be described in terms of their molar ratios to each other. In embodiments, the quinone methide and ammonium salt are present in a molar ratio ranging from greater than 1:1 to about 1000:1, greater than 1:1 to about 250:1, greater than 1:1 to about 100:1, greater than 1:1 to about 50:1, greater than 1:1 to about 25:1, greater than 1:1 to about 20:1, or greater than 1:1 to about 15:1, respectively.

[0115] A composition comprising a predetermined amount of a quinone methide polymerization retarder and an ammonium salt can be prepared such that when the composition is added to a monomer composition or a composition capable of forming a monomer, both the quinone methide polymerization retarder and the ammonium salt are at working concentrations in the monomer composition. Various working ranges of the quinone methide polymerization retarder and the ammonium salt are described herein.

[0116] Optionally, polymerization inhibitors, such as those capable of forming stable nitroxide groups, can be used in small amounts along with the quinone methide polymerization retarder and ammonium salt, or can be omitted from the composition entirely.

[0117] In the presence of polymerizable monomers, a "polymerization inhibitor" inhibits the formation of polymer from those monomers during an induction period. After the induction period has elapsed, polymer formation occurs at substantially the same rate as it would form in the absence of the polymerization inhibitor.

[0118] "Polymerization retarders," such as the quinone methide compounds disclosed herein, do not exhibit an induction time, but instead, once added to a polymerizable monomer composition, reduce the rate at which polymer formation occurs compared to the rate at which it would have formed in the absence of the composition of interest.

[0119] In contrast to polymerization retarders, polymerization inhibitors are generally consumed rapidly. Polymerization retarders slow the rate of polymerization reactions, but generally not as effectively as polymerization inhibitors. However, polymerization retarders are usually not consumed as quickly as polymerization inhibitors.

[0120] Polymerization inhibitors and retarders may generally be considered "polymerization inhibitors," which are compounds capable of inhibiting or reducing the formation of polymers from one or more radically polymerizable compounds.

[0121] Exemplary polymerization inhibitors having an N to O bond that can be used in small amounts or can be completely excluded from the composition include nitroxides, amine oxides, hydroxylamines, nitro, nitroso, and nitrone-containing compounds. For example, in a composition comprising a polymerizable monomer, a quinone methide, and an ammonium salt, the nitroxyl group-containing polymerization inhibitor can optionally be present in an amount of less than 50 ppm, less than 25 ppm, less than 10 ppm, less than 5 ppm, less than 2.5 ppm, less than 2 ppm, less than 1.5 ppm, less than 1 ppm, less than 0.75 ppm, or less than 0.5 ppm, or can be completely excluded from the composition.

[0122] For example, in a composition comprising a polymerizable monomer and a nitrogen- and oxygen-containing aromatic polymerization inhibitor, the nitroxyl group-containing polymerization inhibitor can optionally be present in an amount less than 50 ppm, less than 25 ppm, less than 10 ppm, less than 5 ppm, less than 2.5 ppm, less than 2 ppm, less than 1.5 ppm, less than 1 ppm, less than 0.75 ppm, or less than 0.5 ppm.

[0123] Exemplary nitroxide-containing polymerization inhibitors that can be used in small amounts or excluded from the composition entirely include 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl (HTMPO), 4-oxo-2,2,6,6-tetramethylpiperidinyl-1-oxyl (OTEMPO), 1-hydroxy-2,2,6,6-tetramethylpiperidine (TEMPOH), 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine (HTMPO), 1- ... H), and 1-hydroxy-4-oxo-2,2,6,6-tetramethylpiperidine (OTEMPOH), N,N-diethylhydroxylamine, and N-isopropylhydroxylamine, di-tert-butylnitroxyl, 1-oxyl-2,2,6,6-tetramethyl-4-n-propoxypiperidine, 1-oxyl-2,2,6,6-tetramethyl-4-n-butoxypiperidine, 1-oxyl-2,2,6,6-tetramethyl-4-t-butoxypiperidine, 1-oxyl-2,2,6,6-tetramethyl-4-s-butoxypiperidin methyl-4-(2-methoxyethoxy)piperidine, 1-oxyl-2,2,6,6-tetramethyl-4-(2-methoxyethoxyacetoxy)piperidine, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl butyrate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl octanoate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl laurate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl benzoate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 4-tert-butylbenzoate, 1-oxyl-2,2,6,6-tetramethyl-4-allyloxy-piperidine, 1-oxyl-2,2,6,6-tetramethyl-4-acetamidopiperidine, 1-oxyl-2,2,6,Examples of suitable hydroxybenzoates include, but are not limited to, 6-tetramethyl-4-(N-butylformamido)piperidine, N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-caprolactam, N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-dodecylsuccinimide, 1-oxyl-2,2,6,6-tetramethyl-4-(2,3-dihydroxypropoxy)piperidine, 1-oxyl-2,2,6,6-tetramethyl-4-(2-hydroxyl-4-oxapentoxy)piperidine, and mixtures thereof. (See, for example, U.S. Pat. No. 9,266,797.) Any of these compounds can be present in the polymerizable monomer composition in very small amounts (less than 50 ppm, 25 ppm, 10 ppm, etc., as described herein) or can be completely excluded from the composition.

[0124] Other exemplary nitroxide-containing polymerization inhibitors that can be used in small amounts or excluded from the composition entirely include bis-nitroxide and tris-nitroxide polymerization inhibitors, such as bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) succinate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, bis(1-oxyl-2,2,6,6-tetramethyl-piperidin-4-yl) n-butyl malonate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate, bis(1-oxyl-2,2,6,6-tetramethylpiperidine N,N'-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)isophthalate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)terephthalate, bis(1-oxyl)-2,2,6,6-tetramethylpiperidin-4-yl)hexahydroterephthalate, N,N'-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipamide, 2,4,6-tris-[N-butyl-N-(1-oxyl-2,266-tetramethylpiperidin-4-yl)]-s-triazine, 2,4,6-tris-[N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)]-s-triazine, 4,4'-ethylenebis(1-oxyl-2,2,6,6-tetramethylpiperazin-3-one), and mixtures thereof. (See, e.g., U.S. Pat. No. 9,266,797.) Any of these compounds can be present in the polymerizable monomer composition in very small amounts (less than 50 ppm, 25 ppm, 10 ppm, etc. as described herein) or can be excluded from the composition entirely.

[0125] Optionally, the composition comprising the quinone methide polymerization retarder and ammonium salt of the present disclosure may comprise R 1 may further comprise a stabilizer compound which is a primary amine such as NH 1 is a linear, branched, or cyclic alkyl group of 4 to 24, 6 to 24, or 8 to 24 carbons, or R 2 NHR 3and other secondary amine stabilizers such as R 2 and R 3 are independently selected from linear, branched, or cyclic alkyl groups of 1 to 23 carbon atoms, with the proviso that R 2 and R 3 is in the range of 4 to 24, 6 to 24, or 8 to 24 carbons, as disclosed in U.S. Application Publication No. 2020 / 0017610 (Masere et al.).

[0126] The method for inhibiting polymerization of monomers in a monomer-containing composition can be carried out by adding a quinone methide polymerization retarder and an ammonium salt component (including one or more optional components) to a composition containing polymerizable monomers. The quinone methide can be added to the monomer composition simultaneously with the ammonium salt, before the addition of the ammonium salt, or after the addition of the ammonium salt, or any combination thereof. The method of adding the quinone methide and the ammonium salt can be carried out to provide a desired concentration of these compounds in the monomer composition at any one or more points during the treatment process.

[0127] The quinone methide polymerization retarder inhibits the polymerization of polymerizable monomers, and the presence of an ammonium salt improves the effectiveness of the quinone methide polymerization retarder.

[0128] The polymerizable monomers subjected to polymerization retardation can contain vinyl or ethylenically unsaturated groups. For example, quinone methide and ammonium salt components can be added to a composition containing one or more of the following polymerizable monomers: acrolein, acrylic acid, acrylonitrile, alkylated styrene, butadiene, chloroprene, divinylbenzene, ethyl acrylate, ethyl methacrylate, isoprene, methacrylic acid, methyl methacrylate, methyl acrylate, α-methylstyrene, methacrylonitrile, styrene, styrene sulfonic acid, vinyl acetate, vinyl toluene, and vinyl pyridine.

[0129] The polymerizable monomer can be present in a crude mixture of compounds, a semi-purified mixture of compounds, or a fully purified mixture of compounds. For example, the quinone methide polymerization retarder and ammonium salt components can be added to a process stream containing the polymerizable monomer. In the method, the components can be added before, during, or after (or a combination thereof) a processing step, such as distillation, in which the compounds in the composition are separated from each other. The components can inhibit polymerization of the monomer at any one or more stages of the processing system, thereby reducing or preventing equipment contamination.

[0130] Alternatively, the quinone methide polymerization retarder and ammonium salt components can be added to a process stream containing compounds (e.g., monomer precursors) that can form polymerizable monomers. For example, in a composition containing compounds that can form polymerizable monomers as undesirable by-products, the presence of the quinone methide polymerization retarder and ammonium salt can inhibit polymerization of the monomers when they are formed as by-products, thus reducing or preventing contamination of equipment.

[0131] In some embodiments, the quinone methide polymerization retarder and the ammonium salt are introduced into a monomer-containing composition to provide the desired amounts of each reagent in the composition. The quinone methide polymerization retarder and the ammonium salt can be introduced simultaneously, such as from a composition in which the components are mixed, or can be delivered individually or in partial combination, sequentially, or overlappingly. The resulting introduction of the components into the monomer-containing composition can provide the quinone methide polymerization retarder and the ammonium salt at the desired concentrations.

[0132] For example, at a polymerizable monomer concentration in the range of 0.05 to 50,000 ppm, a quinone methide polymerization retarder can be introduced to provide a retarder in an amount in the range of 125 to 250 ppm, and an ammonium salt can be introduced to provide an ammonium salt in an amount in the range of 5 to 25 ppm. Alternatively, a quinone methide polymerization retarder can be introduced to provide a retarder in an amount in the range of 150 to 225 ppm, and an ammonium salt can be introduced to provide an ammonium salt in an amount in the range of 12 to 20 ppm.

[0133] In some implementations, the quinone methide polymerization retarder and ammonium salt are optionally used in small amounts with a polymerization inhibitor, such as a nitroxide-containing polymerization inhibitor (e.g., HTEMPO), or the nitroxide-containing polymerization inhibitor can be completely eliminated from the process. For example, in some implementations, the polymerization inhibitor is added to a polymerizable monomer composition, such as a process stream, before adding the quinone methide polymerization retarder and ammonium salt. The polymerization inhibitor can be added over a period of time, and then the quinone methide polymerization retarder and ammonium salt can be added after that period (i.e., sequentially), or the addition of the polymerization inhibitor, quinone methide polymerization retarder, and ammonium salt to the polymerizable monomer composition can overlap. In other implementations, the polymerization inhibitor, quinone methide polymerization retarder, and ammonium salt can be added simultaneously to the polymerizable monomer composition. The use of a quinone methide and ammonium salt can significantly reduce the amount of polymerization inhibitor in the monomer composition.

[0134] The term "fouling" refers to the formation of polymers, prepolymers, oligomers, and / or other materials that become insoluble in a stream and / or precipitate from the stream and deposit on the equipment under the conditions of operation of the equipment. Quinone methide polymerization retarders potentiated with ammonium salts, in turn, can be referred to as "anti-fouling" because they prevent or reduce such formation.

[0135] Optionally, the ability of the composition of the present disclosure to inhibit polymerization can be illustrated by comparing it with a composition that does not contain an ammonium salt. The effect of the ammonium salt can be understood by measuring the formation of a polymer (e.g., polystyrene) over time in a monomer (e.g., styrene) composition (comparison of a retarder but not containing an ammonium salt) in the presence of a composition containing a quinone methide polymerization retarder and an ammonium salt. For example, a composition of the present disclosure containing a quinone methide polymerization retarder and an ammonium salt improves the inhibition of monomer polymerization by more than about 1.2 times, more than about 1.4 times, more than about 1.4 times, more than about 1.5 times, more than about 2 times, more than about 3 times, more than about 4 times, more than about 5 times, more than about 6 times, more than about 7 times, more than about 8 times, more than about 9 times, and in some cases more than about 10 times, compared to a composition containing a quinone methide polymerization retarder but not containing an ammonium salt under the same conditions.

[0136] For the combination of exemplary quinone methides (QMCinn, QMPh) with exemplary ammonium salts (TIPA-2-EH, DIHA-2-EH), and the experimental studies described herein, the combinations provided improved polymerization inhibitor activity over compositions having only the quinone methide, and even over the nitro-containing polymerization inhibitor DNBP. Improvements were observed throughout the testing period of the polymerization inhibitors.

[0137] The combination provided improved inhibitor activity over QMCinn alone across most time points tested, with the improvement becoming more pronounced over time, with the combination of QMCinn and TIPA-2-EH showing over 6-fold improvement over QMCinn at the last time point (120 min), even when QMCinn was used at lower concentrations. The combination of QMCinn and TIPA-2-EH also outperformed the nitro-containing inhibitor DNBP at most time points measured.

[0138] The quinone methide polymerization retarder and ammonium salt components (and any other optional components) may be used in conjunction with compositions containing polymerizable monomers and "process equipment" associated with the process that may be subject to fouling from monomer polymerization, such as reactors, reactor beds, piping, valves, distillation columns, trays, condensers, heat exchangers, compressors, fans, impellers, pumps, recirculators, intercoolers, sensors, etc. The term also includes sets of these components where multiple components are part of a "system."

[0139] In one preferred method of use, the disclosed composition, which includes a quinone methide polymerization retarder, an ammonium salt, and a solvent (e.g., glycol), is used in a process involving a distillation column used to separate and purify vinyl monomers, such as styrene. For example, in processes known in the art, ethylbenzene can be subjected to a catalytic dehydrogenation reaction, resulting in the formation of styrene. The styrene-containing reaction product also includes other materials, such as aromatic compounds, such as toluene and benzene, unreacted ethylbenzene, and polymers. This mixture of compounds is typically fractionally distilled using one or more distillation columns. Heat is typically used to aid in the separation of components within the distillation column. After distillation, the fractionated components can be separated into pure product streams of increasing purity. Optionally, the quinone methide polymerization retarder and ammonium salt are used in conjunction with a polymerization inhibitor, such as a nitroxide-containing polymerization inhibitor (e.g., HTEMPO), in the distillation column used to separate and purify vinyl monomers.

[0140] The quinone methide polymerization retarder and the ammonium salt-containing composition can be introduced into the stream leading from the reaction bed to the distillation column, or can be added directly to the distillation column. The composition can be added before heating the monomer composition or while heating the monomer composition in the distillation column. In embodiments, the ammonium salt has a boiling point higher than that of the desired compound or distillate (e.g., a monomer such as styrene) being fed to the distillation column, and during the distillation process, the desired compound is separated from the ammonium salt due to the temperature difference. In embodiments, the boiling point difference between the desired compound and the ammonium salt is about 10°C or higher, about 15°C or higher, about 20°C or higher, about 25°C or higher, about 30°C or higher, about 35°C or higher, about 40°C or higher, about 45°C or higher, or about 50°C or higher.

[0141] Alternatively, or in addition to adding the quinone methide polymerization retarder and ammonium salt-containing composition during the distillation process, the composition can optionally, or additionally, be added to a distillation effluent stream, such as a purified styrene stream. Optionally, a nitroxide-containing polymerization inhibitor (such as HTEMPO) can be added to the distillation effluent stream before or together with the quinone methide polymerization retarder and ammonium salt.

[0142] The quinone methide polymerization retarder and ammonium, optionally with one or more other components, can be used with any "hydrocarbon process stream" that may contain unsaturated monomers to stabilize the stream during transportation and storage. In some implementations, the quinone methide polymerization retarder and ammonium salt components can be used in conjunction with a "petroleum product," which refers to any hydrocarbon product obtained from an underground reservoir, any product derived therefrom, or any mixture thereof. The polymerizable monomer can be contained in the petroleum product or chemically derived from the petroleum product. Non-limiting examples of petroleum products include, but are not limited to, crude oil, reduced crude oil, crude distillate, heavy oil, or by-products of petroleum product processing such as bitumen, hydrotreated oil, refined oil, thermal cracking, hydrotreating, or phase separation, or a mixture of two or more thereof. A liquid petroleum product is a petroleum product that is substantially liquid at 20°C.

[0143] The quinone methide polymerization retarder and ammonium salt components can be added to or present in a "petroleum process stream," which refers to any petroleum product placed within a petroleum process facility in fluid contact with its interior surfaces.

[0144] The petroleum process stream may contain one or more polymerizable monomers or may be formed as a by-product. The process stream may be substantially static, such as a petroleum product placed in a settler (separator) or storage vessel for a selected contact period, such as up to two years. The process stream may be substantially dynamic, such as a liquid petroleum product placed in a pipe during transport of the product from a first location to a second location. In some embodiments, the process stream includes one or more additional components associated with petroleum processing, and such components are not particularly limited.

[0145] "Petroleum process equipment" or "petroleum processing apparatus" refers to a man-made object having an inner surface containing metal, and further comprising one or more petroleum products thereon, for any period of time and at any temperature, as determined by context. Petroleum process equipment includes items for removing petroleum products from underground reservoirs, transporting one or more petroleum products from a first location to a second location, or separating, refining, treating, separating, distilling, reacting, metering, heating, cooling, or containing one or more petroleum products.

[0146] In embodiments, compositions comprising a quinone methide polymerization retarder and an ammonium salt are thermally stable and have retarder activity in process streams or other polymerizable monomer-containing compositions at temperatures of from about 20°C to about 400°C, e.g., from about 100°C to about 400°C, or from about 100°C to about 350°C, or from about 100°C to about 300°C, or from about 100°C to about 250°C, or from about 100°C to about 200°C, or from about 100°C to about 150°C.

[0147] In embodiments, a composition comprising a quinone methide polymerization retarder and an ammonium salt can be introduced into a composition comprising a polymerizable monomer, such as a liquid petroleum process stream, in a batch, continuous, or semi-continuous manner. In some embodiments, the quinone methide polymerization retarder and ammonium salt (and any other optional components) are introduced manually, while in other embodiments, their introduction is automated. In embodiments, the amount of quinone methide polymerization retarder and ammonium salt introduced over a selected unit of time varies depending on the variable composition of the associated process stream. Such variability in the feed can be achieved manually by periodically testing the internal surfaces of the process equipment, after adjusting the amount of composition up or down based on test results, or automatically by monitoring one or more conditions internal to the petroleum process equipment and signaling the need to apply more composition to the process stream.

[0148] In some embodiments, the quinone methide polymerization retarder and ammonium salt are added to a petroleum product that is crude oil, reduced crude oil, heavy oil, bitumen, coker charge, hydrotreater influent, hydrotreater effluent, flash crude oil, light cycle oil, or a diesel or naphtha refinery stream. In embodiments, the compounds are added to petroleum process equipment traditionally associated with the gathering, processing, transporting, or storing one or more of crude oil, reduced crude oil, crude oil distillate, heavy oil, bitumen, coker charge, flash crude oil, light cycle oil, or a diesel or naphtha refinery stream, and including piping and related infrastructure used to fluidly connect process equipment items to facilitate processing of the process streams located therein.

[0149] Equipment containing a polymerizable monomer-containing composition treated with a quinone methide polymerization retarder and an ammonium salt and any other optional ingredients can reduce or eliminate fouling of the interior surfaces of the equipment. In embodiments, fouling is measured as a relative increase in solids retention in the treated composition compared to solids retention in the untreated composition over the same period. In embodiments, fouling is measured as a relative decrease in the weight or volume of sediment resulting from a selected period of contact of a treated process stream within the relevant item of process equipment compared to the same period of contact of the process equipment with a corresponding untreated process stream. Stated differently, the reduction in fouling is the relative decrease in the measured weight or volume of solids deposited or precipitated from process equipment contacted with a treated process stream over a selected period of time when compared to the weight or volume of solids deposited or precipitated from an untreated process stream over the same period of time.

[0150] Quinone methide polymerization retarders and ammonium salts can also inhibit undesired polymerization and fouling of process equipment in primary fractionation processes, light ends fractionation, non-aromatic vinyl halide fractionation and stabilization, process gas compression, dilution steam systems, caustic towers, quench towers, quench water separators (pyrolysis gasoline), butadiene extraction, propane dehydrogenation, diesel and gasoline fuel stabilization, olefin metathesis, styrene refining, hydroxyhydrocarbon refining, stabilization of vinyl monomers during transportation and storage, or retard polymerization of resins and compositions containing ethylenically unsaturated species.

[0151] The quinone methide polymerization retarder and ammonium salt can be added at one or more locations at any given time in the process. For example, such compositions can be added directly to an interstage cooler or compressor, or upstream of an intercooler or compressor. The quinone methide polymerization retarder and ammonium salt can be added continuously or intermittently to process equipment as needed to prevent or reduce fouling.

[0152] The quinone methide polymerization retarder and ammonium salt can be introduced into the desired system by any suitable method. For example, they may be added as a neat or diluted solution. In some embodiments, the composition containing the quinone methide polymerization retarder and ammonium salt can be applied as a solution, emulsion, or dispersion that is sprayed, dripped, poured, or injected into the desired opening in the system or into process equipment or process condensate. In some embodiments, the composition can be added with cleaning oil or tempered water.

[0153] After introducing the composition into the process equipment, the treated process equipment may be observed to have less buildup on the equipment than process equipment without the addition of the composition. The reduction or prevention of fouling may be assessed by any known method or test. In some embodiments, the reduction or prevention of fouling may be assessed by measuring the time it takes for samples to gel with and without the antifoulant composition. See the Experimental Section for further details. [Example]

[0154] Example 1: Polymerization inhibitor activity of QMCinn (comparison)

[0155] To test the ability of polymerization inhibitor compounds to inhibit the formation of polystyrene from a styrene monomer solution, stabilizer-free styrene was freshly prepared by removing 4-tert-butylcatechol (TBC) immediately before use to prepare a solution of 0.679 mmol of 7-cinnamylquinone methide (QMCinn, 2,6-di-tert-butyl-4-(3-phenylallylidene)cyclohexa-2,5-dienone, U.S. Patent No. 9,957,209) and styrene. The solution was transferred in 10 mL aliquots to 24 pressure tubes. After removing dissolved oxygen from the solution, the test tubes were capped using PTFE screw caps equipped with fluoroelastomer (FETFE) O-rings. All tubes were placed in a heating block preheated to 120 °C. Four reaction tubes were removed from the heating block at 20-minute intervals. To quench the polymerization, the four tubes were immediately placed in an ice bath, followed by immediate dilution of the reaction mixture with toluene. A proprietary method was used to determine the concentration of polystyrene product in the reaction mixture. This method was used to test the polymerization inhibitor activity of the quinone methides QMCinn (Example 1) and QMPh (Example 2), the nitro-containing polymerization inhibitor DNBP (Example 3), a combination of QMCinn with the ammonium salt TIPA-2-EH (Example 9), a combination of QMPh with the ammonium salt DIHA-2-EH (Example 10), and a combination of QMPh with the ammonium salt TIPA-2-EH (Example 11). The polymerization inhibitor activity of QMCinn without the ammonium salt is shown in Table 1.

[0156] Example 2: Polymerization inhibitor activity of QMPh (comparison)

[0157] The polymerization inhibitor activity of 7-phenylquinone methide (QMPh, 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone, U.S. Patent Application Publication No. 2006 / 0163539) was tested at a concentration of 0.679 mmol with styrene according to the method described in Example 1. The polymerization inhibitor activity of QMCinn without ammonium salt is shown in Tables 2 and 3.

[0158] Example 3: Polymerization inhibitor activity of DNBP (comparison)

[0159] The polymerization inhibitor activity of the nitro-group-containing polymerization inhibitor 2-sec-butyl-4,6-dinitrophenol (DNBP) was tested at a concentration of 0.679 mmol in freshly prepared styrene according to the method described in Example 1. The polymerization inhibitor activity of DNBP is shown in Tables 1-3.

[0160] Example 4: Synthesis of triisopropylammonium acetate ionic liquid (TIPA-Ac)

[0161] The ammonium salt triisopropylammonium acetate (TIPA-Ac) was prepared using the following process: 30.543 g (151.7 mmol) of a liquid solution of triisopropanolamine (TIPA, 95% w / w) and 8.73 mL (151.7 mmol) of concentrated acetic acid (99.6% w / w) were added to 100 g of toluene. The reaction mixture was stirred at ambient temperature until the TIPA dissolved into the solution and it became opaque. After mixing was stopped, two liquids formed upon settling. The toluene was removed using a vacuum, leaving a viscous liquid, amber in color.

[0162] Example 5: Synthesis of triisopropylammonium ethylhexanoate ionic liquid (TIPA-EH)

[0163] The ammonium salt triisopropylammonium ethylhexanoate (TIPA-EH) was prepared using the following process: 19.411 g (96.41 mmol) of a liquid solution of triisopropanolamine (TIPA, 95% w / w) and 15.4 mL (14.04 g, 96.41 mmol) of 2-ethylhexanoic acid were added to 300 g of toluene at ambient temperature.

[0164] Example 6: Triethylammonium acetate (TEA-Ac) ionic liquid

[0165] The ammonium salt triethylammonium acetate (TEA-Ac) was prepared using the following process: A liquid solution of 7.836 g (77.44 mmol) of triethylamine (TEA) and 77.44 mmol of acetic acid was added to 300 g of toluene at ambient temperature.

[0166] Example 7: Synthesis of N,N-diethylhydroxylammonium 2-ethylhexanoate ionic liquid (DEHA-2-EH)

[0167] The ammonium salt N,N-diethylhydroxylammonium 2-ethylhexanoate (DEHA-2-EH) was prepared using the following process: 29.090 g (319.8 mmol) of a liquid solution of diethylhydroxylamine (DEHA) and 46.586 g (319.8 mmol) of 2-ethylhexanoic acid were added to 300 g of toluene. The reactants were mixed in toluene for 10 minutes, and then the toluene was removed to yield a yellow, clear liquid.

[0168] Example 8: Synthesis of di(hydroxypropyl)hydroxylammonium 2-ethylhexanoate ionic liquid (DHPHA-2-EH)

[0169] The ammonium salt di(hydroxypropyl)hydroxylammonium 2-ethylhexanoate ionic liquid (DHPHA-2-EH) was prepared using the following process: A liquid solution of 3.418 g (25.149 mmol) of di(hydroxypropyl)-hydroxylamine (DEHA) and 3.627 g (25.149 mmol) of 2-ethylhexanoic acid was added to 300 g of toluene at ambient temperature.

[0170] Example 9: Composition of QMCinn and Triisopropanolammonium 2-ethylhexanoate Ionic Liquid

[0171] The polymerization inhibitor activity of the combination of QMCinn (see Example 1) used at 0.611 mmolal (a 90% reduction from 0.679 mmolal) and TIPA-2-EH at 0.0679 mmolal (Example 5, used at an 11% mmolal concentration of QMCinn) was measured in the presence of stabilizer-free styrene using the method described in Example 1. The polymerization inhibitor activity of the combination, as well as the data for QMCinn and DNBP used alone, is shown in Table 1.

[0172] The combination of QMCinn and TIPA-2-EH showed improved inhibitor activity over QMCinn alone across most time points tested, and the combination of QMCinn and TIPA-2-EH showed a greater than six-fold improvement over QMCinn at the last time point (120 min), even when lower concentrations of QMCinn were used. The combination of QMCinn and TIPA-2-EH also outperformed the nitro-containing inhibitor DNBP across most time points measured.

[0173] [Table 1]

[0174] Example 10: Composition of QMPh and N,N-diethylhydroxylammonium 2-ethylhexanoate ionic liquids

[0175] The polymerization inhibitor activity of the combination of 0.611 mmol of QMPh and 0.0679 mmol of N,N-diethylhydroxylammonium 2-ethylhexanoate ionic liquid (DIHA-2-EH) was determined in the presence of stabilizer-free styrene using the method described in Example 1. The polymerization inhibitor activity of the combination, as well as data for QMPh and DNBP used alone, is shown in Table 2.

[0176] The combination of QMPh and DIHA-2-EH showed improved inhibitory activity over QMPh alone at all time points tested, and showed a greater than 10-fold improvement over QMPh at the early time point (20 min), even when QMPh was used at a lower concentration in the combination. The combination of QMPh and DIHA-2-EH also showed inhibitory activity comparable to that of the nitro-containing inhibitor DNBP.

[0177] [Table 2]

[0178] Example 11: Composition of QMPh and Triisopropanolammonium 2-ethylhexanoate Ionic Liquids

[0179] The polymerization inhibitor activity of the combination of 0.611 mmol of QMPh and 0.0679 mmol of N,N-triisopropanolammonium 2-ethylhexanoate (TIPA 2-EH) ionic liquid was determined in the presence of stabilizer-free styrene using the method described in Example 1. The polymerization inhibitor activity of the combination, as well as data for QMPh and DNBP used alone, is shown in Table 3.

[0180] The combination of QMPh and TIPA 2-EH showed improved inhibitory activity over QMPh alone at all time points tested, ranging from approximately 1.3 to approximately 4 times higher than QMPh alone, even when QMPh was used at lower concentrations in the combination. The combination of QMPh and TIPA 2-EH also showed inhibitory activity comparable to that of the nitro-containing inhibitor DNBP at early time points.

[0181] [Table 3]

Claims

1. A composition comprising a quinone methide and an ammonium salt.

2. The quinone methide has Formula I: 【Chemical 1】 wherein R １ and R ２ is independently selected from C4-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl; R ３ and R ４ are independently —H, C1 to C18 alkyl, phenyl, substituted phenyl, C5 to C12 cycloalkyl, —CN, —COOH, —C═CHR ５ , -C≡CR ５ , -COOR ５ , -COR ５ , -OCOR ５ , -CONHR ５ and R ５ The composition of claim 1, wherein is selected from H, C1-C18 alkyl, C5-C12 cycloalkyl, phenyl, and C7-C15 cycloalkyl, and substituted phenyl.

3. The composition of claim 2, wherein the quinone methide is a 7-phenyl quinone methide.

4. The ammonium salt has the formula III: 【Chemistry 2】 a cation of １ , R ２ , R ３ , and R ４ are independently selected from (a) —H, (b) a carbon-containing group, (c) an oxygen-containing group, or (d) an oxygen- and carbon-containing group), or a group represented by Formula IV: 【Chemistry 3】 a cation of ５ is a monovalent or polyvalent carbon-containing group, y is an integer ranging from 1 to 4, and R ６ , R ７ , and R ８ are independently selected from (a)-(d) as described.

5. In the cation of formula III, R １ , R ２ , R ３ , and R ４ or in the cation of formula IV, R ６ , R ７ , and R ８ The composition of claim 4, wherein at least two of are any one of (b) to (d) or a combination thereof.

6. 6. The composition of claim 4 or 5, wherein (b) the carbon-containing group consists of carbon, oxygen, and hydrogen; (c) the oxygen-containing group consists of oxygen and hydrogen; and (d) the oxygen- and carbon-containing group consists of carbon, oxygen, and hydrogen, or any combination of (b) to (d).

7. 7. The composition of any one of claims 1 to 6, wherein the cation of the ammonium salt is: (a) a total amount of carbon atoms in the range of 0 to 18, 1 to 12, or 2 to 10; (b) a total amount of oxygen atoms in the range of 0 to 6, 1 to 4, or 1 to 3; (c) a total amount of hydrogen atoms in the range of 4 to 40, 6 to 30, or 8 to 24, or any combination of (a) to (c).

8. The composition of any one of claims 4 to 7, wherein the carbon-containing group is selected from C1 to C18 alkyl, aryl, alkylaryl, and arylalkyl.

9. The carbon-containing group is (a) a straight-chain or branched C1-C12 alkyl group or selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl; (b) a C1-C12 cycloalkyl group or selected from the group consisting of cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl; (c) a C1-C14 aryl group or selected from the group consisting of phenyl, ethylphenyl, tolyl, naphthyl, and anthracyl; or (d) a linear or branched C1 to C12 alkylene group, or selected from the group consisting of allyl and isobutenyl.

10. The oxygen and carbon containing group has the formula VIII: 【Chemistry 4】 wherein R １５ , R １６ , R １７ , R １８ , and R １９ However, independently, H, C １ ~C １８ Alkyl, aryl, alkylaryl, arylalkyl, and —OR ２０ is selected from OR ２０ But, R １５ ~R １９ and Formula VIII has the same meaning as any one of the groups represented by at least one -OR ２０ group or R １６ and R １７ 10. The composition of any one of claims 4 to 9, wherein are divalent hydrocarbon-containing groups linked together to form a cyclic alkyl or aryl group, and y is an integer ranging from 1 to 3.

11. 11. The composition of any one of claims 4 to 10, wherein the oxygen- and carbon-containing group is a straight-chain or branched C1 to C18 hydroxyalkyl group or is selected from the group consisting of hydroxymethyl, 1- or 2-hydroxyethyl, 1-, 2-, or 3-hydroxypropyl, 2-hydroxyisopropyl, 1-, 2-, 3-, or 4-hydroxybutyl, and 1-, 2-, or 3-hydroxyisobutyl.

12. 11. The composition of any one of claims 4 to 10, wherein the oxygen- and carbon-containing group is selected from the group consisting of 2-benzoxazolyl, adipyl, glutaryl, succinyl, malonyl, acetyl, acrylyl, methacrylyl, caproyl, benzoyl, phthaloyl, terephthaloyl, carbethoxy, carbonyl, and formyl.

13. 8. The composition of any one of claims 4, 5, or 7, wherein the carbon-containing group is a nitrogen- and carbon-containing group selected from the group consisting of 1,3,5-sym-triazinyl, 2-benzimidazolyl, 2-pyridyl, and 2-pyrazinyl.

14. 8. The composition of any one of claims 4, 5, or 7, wherein the carbon and oxygen containing group is a nitrogen, oxygen, and carbon containing group such as selected from the group consisting of 2-pyrimidinyl and aminocarbonyl.

15. The composition of any one of claims 4 to 8, wherein the carbon-containing group is an oxygen, sulfur and carbon-containing group, such as 3-mercaptopropionyl.

16. 6. The composition of claim 4 or 5, wherein the oxygen-containing group is hydroxyl.

17. R １ , R ２ , R ３ , and R ４ is —H or R ６ , R ７ , and R ８ The composition of any one of claims 4 to 16, wherein one of is -H.

18. The ammonium salt is represented by formula VI: 【Chemistry 5】 wherein R ６ , R ７ , and R ８ The composition of any one of claims 4 to 17, wherein:

19. 19. The composition of any one of claims 4 to 18, wherein the cation is selected from the group consisting of N,N-triisopropanolammonium, N,N,N-tris(2-hydroxy-2-phenyl)ammonium, N,N-diethylhydroxylammonium, N,N-di-isopropylammonium, N,N-dibenzylhydroxylammonium, N,N-bis(2-hydroxy-2-phenyl)hydroxylammonium (N,N-bis(2-hydroxyphenyl)hydroxyl-ammonium), N,N-bis-(3-butoxy-2-hydroxypropyl)hydroxylamine, N,N'-di-sec-butylphenylenediammonium, N-sec-butyl-N'-phenylphenylenediammonium, N,N'-di-phenylphenylenediammonium, N,N-di-propyl-butylphenylenediammonium, N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediammonium, and N-1,4-dimethylpentyl-N'-phenyl-p-phenylenediammonium.

20. The composition of any one of claims 1 to 19, wherein the ammonium salt comprises an anion comprising a carboxylate group, a sulfonate group, a phosphonate group, a nitrate group, or a combination thereof.

21. 21. The composition of claim 20, wherein the anion comprises a carboxylate group.

22. 20. The composition of claim 18 or 19, wherein the amount of carbon atoms in the anion ranges from 2 to 18, 3 to 12, or 4 to 10.

23. The composition according to any one of claims 20 to 22, wherein the amount of oxygen atoms of the anion is in the range of 2 to 4.

24. The anion is Acetate (Ethanoate); Propionate (propanoate); Butyrate (butanoate), isobutyrate (2-methylpropanoate); Valerate (pentanoate), isovalerate (3-methylbutanoate), 2-methylbutanoate, pivalate (2,2-dimethylpropanoate); Caproate (hexanoate), 2-methylvalerate, 3-methylvalerate, 4-methylvalerate, 2,2-2,2-dimethylbutanoate, 2-ethylbutanoate; Heptanoate (enanthoate), 2-methylcaproate, 3-methylcaproate, 4-methylcaproate, 5-methylcaproate, 2,2-dimethylvalerate, 2-ethylvalerate; 22. The composition of claim 21, wherein the hydroxybenzoate is selected from the group consisting of caprylate (octanoate), 2-methylheptanoate, 3-methylheptanoate, 4-methylheptanoate, 5-methylheptanoate, 6-methylheptanoate, 2,2-dimethylcaproate, 2-ethylcaproate (2-ethylhexanoate), and 2-propylvalerate.

25. 25. The composition of any one of claims 1 to 24, wherein the quinone methide is present in a molar amount greater than the ammonium salt.

26. The composition of any one of claims 1 to 25, consisting essentially of said quinone methide and said ammonium salt.

27. The composition of any one of claims 1 to 25, further comprising an organic solvent.

28. 26. The composition of any one of claims 1 to 25, further comprising a polymerization inhibitor compound selected from the group consisting of nitroxide-containing compounds, amine oxide-containing compounds, hydroxylamine-containing compounds, nitroso-containing compounds, and nitrone-containing compounds.

29. Use of a composition according to any one of claims 1 to 28 for inhibiting the polymerization of monomers in the composition.

30. Use of the composition according to any one of claims 1 to 28 for the synthesis, purification or purification process of polymerizable monomers.

31. Use of a composition according to any one of claims 1 to 28 for storing or transporting polymerizable monomers.

32. 1. A method for inhibiting polymerization of a monomer in a composition, the method comprising: providing a composition comprising a polymerizable monomer or a compound capable of forming a polymerizable monomer, a quinone methide, and an ammonium salt; The method, wherein the polymerization of the polymerizable monomer is inhibited in the presence of a quinone methide, an ammonium salt.

33. 33. The method of claim 32, comprising simultaneously adding the quinone methide and the ammonium salt to a composition comprising a polymerizable monomer or a compound capable of forming a polymerizable monomer.

34. 34. The method of claim 33, wherein the method comprises adding the quinone methide to the composition before the ammonium salt or adding the quinone methide to the composition and the ammonium salt.

35. The method of any one of claims 32 to 34, wherein the polymerizable monomer comprises a vinyl or ethylenically unsaturated group.

36. 36. The method of any one of claims 32 to 35, wherein the polymerizable monomer is selected from the group consisting of acrylic acid, acrylonitrile, alkylated styrene, butadiene, chloroprene, divinylbenzene, ethyl acrylate, ethyl methacrylate, isoprene, methacrylic acid, methyl methacrylate, methyl acrylate, α-methylstyrene, methacrylonitrile, styrene, styrene sulfonic acid, vinyl toluene, and vinyl pyridine.

37. The method of any one of claims 32 to 36, wherein the composition comprises one or more non-polymerizable hydrocarbons.

38. 38. The method of any one of claims 32 to 37, carried out during the purification or processing of one or more components of the composition.

39. 38. The method of any one of claims 32 to 37, carried out before storing or transporting the second composition.

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