Synergistic fouling inhibitor composition and method of using the same
A synergistic blend of stable nitroxide radicals, phenothiazines, and functional solvents addresses the issue of polymerization inhibitor degradation under acidity, effectively inhibiting monomer polymerization and preventing equipment fouling.
Patent Information
- Application Number
- JP2025500323
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-07-08
- Filing Date
- 2023-07-06
- Publication Date
- 2025-07-10
AI Technical Summary
Conventional polymerization inhibitors, such as stable free radicals, deteriorate under acidic conditions, leading to ineffective inhibition of ethylenically unsaturated monomer polymerization, resulting in equipment fouling and production inefficiencies.
A composition comprising a stable nitroxide radical or derivative, phenothiazine or derivative, and optionally substituted imidazoline or sulfone in a functional solvent, which demonstrates synergistic polymerization inhibition even under acidic conditions.
The composition effectively inhibits the polymerization of ethylenically unsaturated monomers, including those under acidic conditions, reducing fouling and improving production efficiency by maintaining inhibitor effectiveness.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure generally relates to compositions comprising blends of polymerization inhibitors and methods of using the same. More specifically, the present disclosure relates to compositions comprising at least one compound having a stable nitroxide radical and a phenothiazine useful for inhibiting the polymerization of ethylenically unsaturated monomers in a functional solvent. The present disclosure further relates to a method for preparing a composition having a stable nitroxide radical or a derivative thereof, and a phenothiazine or a derivative thereof in a functional solvent.
Background Art
[0002] The production of ethylenically unsaturated monomers typically involves three stages: reaction, recovery, and purification. Distillation operations at elevated temperatures often accompany the recovery and purification stages. Ethylenically unsaturated monomers, such as vinyl acetate, acrylate, and methacrylate monomers, may be present in the process stream or in the purified products produced by various chemical industry processes. However, these monomer types may undesirably polymerize through radical polymerization, especially at elevated temperatures in the presence of a polymerization initiator. As a result, viscous or solid deposits of polymers can form on the surfaces of process equipment during industrial manufacturing, processing, handling, or storage. The resulting polymers can be problematic and can lead to "fouling" of the equipment and contamination of the product. Thus, this may require treating the equipment to remove the polymer or may require a treatment step to remove the polymer from the composition stream or the stored composition. These undesirable polymerization reactions consume valuable reagents, resulting in a decrease in production efficiency, and additional steps may be required to clean the equipment and / or remove the unwanted polymer.
Summary of the Invention
Problems to be Solved by the Invention
[0003] The early polymerization of these monomers is generally controlled by administering a polymerization inhibitor capable of reducing the early polymerization of the monomers. Conventional polymerization inhibitors include stable free radicals that can effectively capture carbon-centered radicals. Conventional polymerization inhibitors such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (HTEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl (OTEMPO) generally deteriorate under acidic environments, reducing their effectiveness as polymerization inhibitors. Therefore, there is a need to develop new polymerization inhibitors, particularly inhibitors that are stable under acidic conditions.
Means for Solving the Problems
[0004] A composition for inhibiting the polymerization of monomers is disclosed herein. The composition includes a first inhibitor compound having a stable nitroxide radical or a derivative thereof, a second inhibitor compound having a phenothiazine or a derivative thereof, and an optionally substituted imidazoline, phthalate, sulfone, or a functional solvent selected from the group consisting of combinations thereof. In some embodiments, the composition is useful for inhibiting the polymerization of ethylenically unsaturated monomers including (meth)acrylic acid, methyl methacrylate, acrylic acid, acrylic esters, methacrylamide sulfate, vinyl acetate, acrylonitrile, acrolein, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, and combinations thereof.
[0005] In some aspects, the first inhibitor compound has the formula (I):
Chemical formula
[0006] In some embodiments, the second inhibitor compound is a phenothiazine of formula (II), [Chemical formula] wherein R5 is hydrogen, C 1~20 alkyl, amine, C1-C 20 aryl, and C1-C 20 heteroaryl, and R6 is selected from the group consisting of H, Cl, CF3, and COCH3. In some embodiments, when R5 is aryl or heteroaryl, it can also be C1-C 12 aryl or C1-C 12 heteroaryl, respectively. In some embodiments, derivatives of the second inhibitor compound can include cases where the R5 group can be attached to nitrogen via an additional C1-C8 alkyl, linear or branched linker, and / or can be further substituted by C 1~20 alkyl or substituted or unsubstituted heterocyclyl. It should be further understood that this can include cases where it can be further substituted.
[0007] In some embodiments, the functional solvent is selected from the group consisting of optionally substituted imidazolines, phthalates, sulfones, and combinations thereof. Preferably, the functional solvent is a mixture of tetramethylene sulfone, water, and dimethyl phthalate, or a mixture of an optionally substituted imidazoline and dimethyl phthalate.
[0008] In some embodiments, the compositions of the present disclosure demonstrate synergy with respect to their ability to inhibit the polymerization of monomers. For example, in some embodiments, the compositions of the present disclosure demonstrate greater polymerization inhibition than the individual components present in the composition and control the dosage of the active ingredient.
[0009] In some embodiments, the compositions of the present disclosure are active even under acidic conditions, unlike conventional polymerization inhibitors known in the art. Thus, in some embodiments, the compositions of the present disclosure also include one or more acids. By way of example, and not limitation, acidic conditions can include a pH of from about 2 to about 7. As a further example, and not limitation, the acid monomer under acidic conditions can be acrylic acid, (meth)acrylic acid, or a hydrolyzed acrylate.
[0010] Also disclosed herein is a method of inhibiting the polymerization of a monomer. The method of inhibiting the polymerization of a monomer includes the step of adding a composition of the present disclosure to the monomer. Addition of the polymerization inhibitor composition of the present disclosure to the monomer inhibits the polymerization of the monomer.
[0011] The foregoing has outlined the features and technical advantages of the present disclosure so that the manner in which the following invention may be better understood may be better understood. Further features and advantages of the present disclosure, which form the subject matter of the claims of this application, will be described below. It should be understood by those skilled in the art that the disclosed concepts and specific embodiments may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present disclosure. It should also be recognized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the present disclosure as set forth in the appended claims.
Embodiments for Carrying Out the Invention
[0012] Various embodiments of the present disclosure are described below. The relationships and functions of the various elements of the embodiments can be more deeply understood by referring to the following detailed description. However, the embodiments are not limited to those expressly described herein.
[0013] The present disclosure relates to a composition comprising a blend of polymerization inhibitors and a method of using the same to inhibit the polymerization of ethylenically unsaturated monomers. The polymerization inhibitor composition of the present disclosure comprises at least one compound having a stable nitroxide radical or a derivative thereof and at least one compound having a phenothiazine or a derivative thereof in a functional solvent. The polymerization inhibitor composition can be a blend of a plurality of components including, in addition to the aforementioned compounds having a stable nitroxide radical or a derivative thereof and a phenothiazine or a derivative thereof, components.
[0014] In the presence of polymerizable monomers, a "polymerization inhibitor" inhibits the formation of polymers from those monomers during an induction time. After the induction time has elapsed, the formation of polymers occurs at a rate substantially the same as the rate at which it would form in the absence of the polymerization inhibitor.
[0015] Polymerization inhibitors and polymerization retarders can generally be regarded as "polymerization preventers", which are compounds capable of inhibiting or reducing the formation of polymers from one or more radically polymerizable compounds.
[0016] The term "fouling" refers to the formation of polymers, prepolymers, oligomers, and / or other materials that become insoluble in the flow and / or precipitate from the flow and deposit on the equipment under the conditions of operating the equipment. Similarly, the inhibitors, retarders, and amine stabilizer components and compositions of the present disclosure can be referred to as "fouling prevention" because they inhibit or reduce such formation.
[0017] The composition of the present disclosure The present disclosure relates to a composition for inhibiting monomer polymerization, comprising a first inhibitor compound having a stable nitroxide radical or a derivative thereof, and a second inhibitor compound having a phenothiazine or a derivative thereof, in a functional solvent. In some embodiments, the composition is for inhibiting monomer polymerization, and the monomer is an ethylenically unsaturated monomer. For example, the compositions of the present disclosure are useful for inhibiting the polymerization of ethylenically unsaturated monomers such as (meth)acrylic acid, methyl methacrylate, acrylic acid, acrylic esters, methacrylamide sulfate, vinyl acetate, acrylonitrile, acrolein, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, and combinations thereof, but are not limited thereto.
[0018] In some embodiments, the first inhibitor compound having a stable nitroxide radical is a compound of formula (I),
Chemical formula
[0019] In some embodiments, the second inhibitor compound having a phenothiazine or a derivative thereof is a compound of formula (II),
Chemical formula
[0020] In some embodiments, derivatives of stable nitroxide radicals can be hydroxylamines that can be prepared by the following reaction.
Chemical formula
[0021] Derivatives of stable nitroxide radicals can also be hydroxylamines that can be prepared by reaction with diethylhydroxylamine.
Chemical formula
[0022] In some embodiments, derivatives of stable nitroxide radicals can be salts that can contain one or more stable nitroxide radical moieties, either in radical form or reduced (hydroxylamine) form. In some embodiments, derivatives of stable nitroxide radicals can be phosphates or phosphites, and in certain embodiments, can further contain additional nitroxide radical moieties.
[0023] In some embodiments, the first inhibitor compound having a stable nitroxide radical or its derivative is
Chemical formula
[0024] In some embodiments, the second inhibitor compound having a phenothiazine or a derivative thereof is [Chemical formula] and is a compound selected from the group consisting of these and combinations thereof.
[0025] In some embodiments, the functional solvent may include imidazoline, phthalate, sulfone, or combinations thereof.
[0026] In some embodiments, the imidazoline is of formula (III), [Chemical formula] wherein R is selected from the group consisting of H, C1-C 30 alkyl, hydroxyl, C1-C 30 alkoxyl, amino, amide, C1-C 30 ester, and C1-C 30 carboxylate.
[0027] In some embodiments, the imidazoline is tall oil hydroxyethyl imidazoline or oleic acid hydroxyethyl imidazoline.
[0028] 20 In some embodiments, the phthalate is C1-C
[0029] phthalate, for example, by way of example and not limitation, dimethyl phthalate or dibutyl phthalate.In some embodiments, the sulfone can be tetramethylene sulfone. In some embodiments, one or more hydrogens in the sulfone can be replaced by halogen, alkyl, or amine. Further non-limiting examples of sulfones useful in the compositions of the present disclosure include 3-methylsulfone propane (CAS number 872-93-5) and 3-aminotetrahydrothiophene-1,1-dioxide hydrochloride (CAS number 51642-03-6).
[0030] In some embodiments, functional solvents can include imidazoline and dimethyl phthalate.
[0031] In some embodiments, the composition unexpectedly demonstrates a synergistic effect, and the combination of the first and second inhibitor compounds results in polymerization inhibition to a greater extent than expected for the combination.
[0032] In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 65 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 60 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 50 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 40 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 30 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 20 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 10 wt%. In some embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present at a concentration of about 5% to about 40 wt%.
[0033] For example, in certain embodiments, the first inhibitor compound having a stable nitroxide radical or a derivative thereof is present in the composition at a concentration of about 0.01 wt%, about 0.1 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, or about 65 wt%.
[0034] In some embodiments, the second inhibitor compound having a phenothiazine or its derivative is present in the composition at a concentration of about 0.01 wt% to about 15 wt%. In some embodiments, the second inhibitor compound having a phenothiazine or its derivative is present in the composition at a concentration of about 0.01 wt% to about 10 wt%. In some embodiments, the second inhibitor compound having a phenothiazine or its derivative is present in the composition at a concentration of about 5% to about 15 wt%.
[0035] For example, in certain embodiments, the second inhibitor compound having a phenothiazine or its derivative is present in the composition at a concentration of about 0.01 wt%, about 0.1 wt%, about 1 wt%, about 5 wt%, about 10 wt%, or about 15 wt%.
[0036] In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 100:1 to about 1:100. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 90:1 to about 1:90. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 80:1 to about 1:80. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 70:1 to about 1:70. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 60:1 to about 1:60. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 50:1 to about 1:50. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 40:1 to about 1:40. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 30:1 to about 1:30. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 20:1 to about 1:20. In some embodiments, the molar ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 10:1 to about 1:10.In some embodiments, the molar ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is from about 5:1 to about 1:5. In some embodiments, the molar ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is about 1:1. Preferably, the molar ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is from about 0.5:1 to about 5:1.
[0037] In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 100:1 to about 1:100. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 90:1 to about 1:90. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 80:1 to about 1:80. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 70:1 to about 1:70. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 60:1 to about 1:60. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 50:1 to about 1:50. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 40:1 to about 1:40. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 30:1 to about 1:30. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 20:1 to about 1:20. In some embodiments, the weight ratio of a first inhibitor compound having a stable nitroxide radical or a derivative thereof to a second inhibitor compound having a phenothiazine or a derivative thereof is from about 10:1 to about 1:10.In some embodiments, the weight ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is from about 5:1 to about 1:5. In some embodiments, the weight ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is about 1:1. Preferably, the weight ratio of the first inhibitor compound having a stable nitroxide radical or a derivative thereof to the second inhibitor compound having a phenothiazine or a derivative thereof is from about 0.5:1 to about 5:1.
[0038] In some embodiments, the functional solvent is from 1 wt% to 99 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 90 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 80 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 70 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 60 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 50 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 40 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 30 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 20 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 10 wt% of the composition. In some embodiments, the functional solvent is from 1 wt% to 5 wt% of the composition.
[0039] For example, in certain embodiments, the functional solvent is present in the composition at a concentration of about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 70 wt%, about 80 wt%, about 90 wt%, or about 99 wt%.
[0040] The composition may also optionally include one or more additional solvents. In certain embodiments, the additional solvent may be selected from water, esters, aromatic compounds, aliphatic compounds, amides, acylamides, alcohols, liquid polymers, and combinations thereof. Preferably, when an alcohol is used, the alcohol is, for example, but not limited to, the same as those used in manufacturing processes such as (meth)acrylate manufacturing processes.
[0041] In some embodiments, the composition also includes one or more ethylenically unsaturated monomers. Those skilled in the art will understand that there are many ethylenically unsaturated monomers that are compatible with the compositions of the present disclosure. For example, in some embodiments, the one or more ethylenically unsaturated monomers are selected from methyl methacrylate, acrylic acid, acrylic esters, methacrylamide sulfate, acrolein, acrylates, methacrylates, vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof. In certain embodiments, the composition also includes vinyl acetate. In certain embodiments, the composition also includes acrylonitrile. In certain embodiments, the composition also includes acrylates. In certain embodiments, the composition also includes methacrylates. In certain embodiments, the composition also includes 1,3-butadiene. In certain embodiments, the composition also includes styrene. In certain embodiments, the composition also includes isoprene. In certain embodiments, the composition also includes (meth)acrylic acid.
[0042] The compositions of the present disclosure are stable and remain useful polymerization inhibitors even under acidic conditions. Thus, the compositions of the present disclosure are useful for inhibiting premature polymerization of monomers during manufacturing processes, particularly those carried out under acidic conditions. For example, the compositions of the present disclosure are useful for preventing the polymerization of acrylates, which may include, but are not limited to, acrylonitrile, acrylic acid, methyl methacrylic acid and its esters, and vinyl acetate.
[0043] In certain embodiments, the compositions of the present disclosure are generally stable under acidic conditions and represent a significant improvement over conventional polymerization inhibitors known in the art. Thus, in some embodiments, the compositions also include one or more acids. For example, in some embodiments, the compositions also include one or more acids selected from the group consisting of mineral acids and carboxylic acids. Mineral acids include, but are not limited to, hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, perchloric acid, etc. Carboxylic acids include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, ethanic acid, caprylic acid, undecylic acid, lauric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, etc. In some embodiments, the compositions of the present disclosure also include hydrochloric acid. In some embodiments, the compositions of the present disclosure also include nitric acid. In some embodiments, the compositions of the present disclosure also include phosphoric acid. In some embodiments, the compositions of the present disclosure also include sulfuric acid. In some embodiments, the compositions of the present disclosure also include acetic acid. In some embodiments, the compositions of the present disclosure also include propionic acid. In some embodiments, the compositions of the present disclosure also include butyric acid. In some embodiments, the compositions of the present disclosure also include valeric acid.
[0044] In some embodiments, the composition can be combined with or used with additional anti-fouling agents, transition metal salts, antioxidants, or anti-foaming agents, such as hydroquinone, that can be injected together or separately in the methods of the present disclosure.
[0045] Methods of using the compositions of the present disclosure The present disclosure also relates to a method of inhibiting the polymerization of a monomer, comprising adding a composition of the present disclosure to the monomer. In some aspects, an effective amount of the composition of the present disclosure is added to the monomer, where the effective amount is any amount sufficient to inhibit the polymerization of the monomer.
[0046] In some embodiments, the monomer is an ethylenically unsaturated monomer. In some embodiments, the monomer is an ethylenically unsaturated monomer selected from vinyl acetate, acrylonitrile, acrylate, methacrylate, 1,3 - butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof, and is disclosed. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of vinyl acetate. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of acrylonitrile. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of acrylate. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of methacrylate. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of 1,3 - butadiene. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of styrene. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of isoprene. In some embodiments, the methods disclosed herein are useful for inhibiting the polymerization of (meth)acrylic acid.
[0047] The compositions of the present disclosure can be added to the fluid manually or automatically. The compositions can also be added continuously and / or intermittently. Automatic addition can be achieved by the use of a chemical injection pump. The chemical injection pump can be programmed to add a specific amount of the polymerization inhibitor composition or any of its components to the fluid at certain time intervals. In another embodiment, the chemical injection pump can be manually controlled to add a specific amount of the polymerization inhibitor composition or any of its components to the fluid. By adding the polymerization inhibitor composition of the present disclosure to the monomer, the polymerization of the monomer is inhibited.
[0048] In some embodiments, the monomer is provided as a neat liquid. In other embodiments, the monomer is provided in a solution hereinafter referred to as a "monomer solution".
[0049] In some embodiments, the monomer solution also contains one or more additional components selected from acids, organic solvents, water, and combinations thereof. For example, in some embodiments, the monomer solution contains one or more organic solvents selected from vinyl acetate, dimethyl phthalate, dimethylformamide, toluene, xylene, highly aromatic naphtha, acetonitrile, ethyl acetate, acetone, dichloromethane, tetrahydrofuran, hexane, dimethyl sulfoxide, N-methyl-2-pyrrolidone, methyl methacrylate, and combinations thereof. In some embodiments, the monomer solution contains one or more acids selected from hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, perchloric acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, ethanoic acid, caprylic acid, undecylic acid, lauric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and suberic acid. In some embodiments, the monomer solution contains water.
[0050] In some embodiments, the monomer solution has a pH value of about 1 to about 7. In some embodiments, the monomer solution has a pH value of about 2 to about 7. In some embodiments, the monomer solution has a pH value of about 1 to about 6. In some embodiments, the monomer solution has a pH value of about 2 to about 6. In some embodiments, the monomer solution has a pH value of about 3 to about 6. In some embodiments, the monomer solution has a pH value of about 4 to about 6. In some embodiments, the monomer solution has a pH value of about 5 to about 6.
[0051] In some embodiments, the composition is added to the monomer such that the total amount of the first inhibitor compound and the second inhibitor compound is present at about 0.1 ppm to 10,000 ppm. In some embodiments, the composition is added to the monomer such that the total amount of the first inhibitor compound and the second inhibitor compound is present at about 0.1 ppm to 5,000 ppm. In some embodiments, the composition is added to the monomer such that the total amount of the first inhibitor compound and the second inhibitor compound is present at about 0.1 ppm to 1,000 ppm. In some embodiments, the composition is added to the monomer such that the total amount of the first inhibitor compound and the second inhibitor compound is present at about 0.1 ppm to 500 ppm. In some embodiments, the composition is added to the monomer such that the total amount of the first inhibitor compound and the second inhibitor compound is present at about 10 ppm to 5,000 ppm.
[0052] The method of the present disclosure is useful for inhibiting premature polymerization of monomers during the manufacturing process, particularly during processes carried out under acidic conditions. For example, the method of the present disclosure is useful for preventing the polymerization of acrylates, which may include, but are not limited to, acrylonitrile, acrylic acid, methyl methacrylic acid and its esters, and vinyl acetate.
[0053] The method of the present disclosure is also useful for preventing premature polymerization of styrene during the manufacturing and purification processes.
[0054] The method of the present disclosure is also useful in the butadiene extraction process. This usefulness results from a balanced partition coefficient between the polar organic phase and the organic phase.
[0055] In some embodiments, the compositions of the present disclosure may include a first inhibitor compound in any of the functional solvents disclosed or contemplated herein. In other embodiments, the compositions of the present disclosure may include a second inhibitor compound in a functional solvent disclosed or contemplated herein. In some embodiments, it should be further understood that separate first and second inhibitor compositions may be injected separately at different process points, may be injected together, or may be combined in the methods of the present disclosure to produce a composition having both a first inhibitor compound and a second inhibitor compound in the solvent of the present disclosure.
[0056] In some embodiments, the compositions of the present disclosure
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[0057] In some embodiments, the compositions of the present disclosure
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[0058] Process for preparing the composition of the present disclosure The composition of the present disclosure can be prepared by a simple blend, for example, but not limited to, dissolving the first inhibitor compound and / or the second inhibitor compound in the same or different solvents, and combining the solutions when in different solvents. Alternatively, the composition can be prepared in situ by adding the first inhibitor compound, the second inhibitor compound, and the functional solvent to a process facility.
[0059] Related manufacturing processes can include, for example, but not limited to, methods for producing methyl methacrylate such as the ACH process of an oxidation process that can be divided into four units (MAA production unit, esterification unit, purification unit, and waste acid unit). The composition of the present disclosure or its components can be injected separately or together. In the purification unit, the first inhibitor compound or the second inhibitor compound can be injected alone or together.
[0060] In the ACH manufacturing process, three reactive monomers, methacrylic acid (MAA), methacrylamide sulfate, and methyl methacrylate (MMA) are present. All of these monomers readily polymerize, causing fouling problems. Usually, the polymerization occurs in the same place, resulting in complex and variable fouling problems. Fouling problems often occur in the esterification unit, purification unit, and waste acid unit. All of these units require inhibitors such as hydroquinone (HQ), phenothiazine (PTZ), and antioxidants that can be used to reduce the fouling problems. Due to the difference in reactivity between the monomers, the inhibitors cannot efficiently reduce or alleviate the fouling problems. For example, HQ and antioxidants are not effective at high temperatures against MAA and MMA fouling, and PTZ only functions against MAA fouling prevention at high temperatures. The compositions and methods disclosed herein can simultaneously solve the fouling problems caused by MMA and MAA. While inhibitor compounds can reduce fouling, functional solvents can move the formed polymer from the equipment, thereby minimizing fouling, reducing fouling agglomeration, and improving the operating time.
Example
[0061] Example 1 - Functional Solvent Performance Test As described in U.S. Patent No. 9,884,951 (incorporated herein by reference in its entirety), different compounds were tested to evaluate the solubility of methyl methacrylate (MMA) deposits from the field. Briefly, dimethyl phthalate (DMP), tall oil hydroxyethyl imidazoline (CAS No. 61791-39-7) (PR-471), polyoxyl stearyl ether (PSE), and tetramethylene sulfone (TS) were tested by placing a sample of MMA foulant particles in each solvent for 1 hour and taking photographs both at the start of the experiment and after 1 hour. The dispersion of the foulant without precipitate demonstrates the effectiveness of the solvent for removing the foulant.
[0062] By a similar method, different compounds and / or mixtures including 50% TS / 50% water (50% TS / H2O), 50% TS / 50% butyl carbitol (50% TS / BC), 30% TS / 70% water (30% TS / H2O), DMP, and 50% TS / 50% DMP (50% TS / DMP) were similarly tested. The incubation was either at room temperature or 80 °C for either 1 hour, 2.5 hours, or 24 hours. The results demonstrate that TS shows good miscibility with the selected compounds and that the formulations still function well when handling MMA deposits, either at room temperature or at high temperature.
[0063] Example 2: Fouling Prevention Performance Test The fouling prevention performance test was conducted by the test tube method. Briefly, a purified monomer (methacrylic acid or methyl methacrylate) was added to a test tube together with a small amount of benzoyl peroxide (BPO), then the fouling prevention formulation was added, nitrogen was bubbled into the liquid to remove oxygen from the liquid, and then the test tube was sealed tightly and heated to a specified temperature.
[0064] The combinations of 35 ppm of HTEMPO and 35 ppm of PTZ (number 1), 70 ppm of HQ (number 2), and the combination of 35 ppm of HQ and 35 ppm of PTZ (number 3) were each tested. In the MMA experiment, 35 ppm of each inhibitor (in the case of two inhibitors) or 70 ppm of HQ was added to 30 mL of monomer having 400 ppm of BPO in separate test tubes and heated at 125 °C for 1.5 hours. In the MAA experiment, the conditions were the same except that the reaction time of HQ was 0.5 hour, PTZ + HQ was 2.5 hours, and HTEMPO + PTZ was 7.5 hours. In all experiments, HTEMPO was dissolved in sulfonate and water (20% HTEMPO, 10% PTZ, 30% tetramethylene sulfone, 30% water, and 10% butyl carbitol).
[0065] The combination of HTEMPO - PTZ showed the best performance. In the test in MMA, the MMA liquid maintained an appearance like water, while the MMA in the control group became a viscous gel at the same reaction time. In the test in MAA, the MAA liquid became turbid at 7.5 hours, while the MMA in the control group became turbid at 1 hour and 2.5 hours respectively. With only PTZ, the time until turbidity was 5.5 hours. In a similar test, HTEMPO alone (50% HTEMPO, 25% sulfone, and 25% water) was able to inhibit polymerization at 0.25 hour. Therefore, the extension of the inhibition time to 7.5 hours shows a synergistic effect.
[0066] All of the compositions and methods disclosed and claimed in this specification can be made and executed without undue experimentation in light of this disclosure. The invention can be embodied in many different forms, and specific preferred embodiments of the invention are described in detail herein. This disclosure is illustrative of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. In addition, unless explicitly stated otherwise, the term "a" is intended to include "at least one" or "one or more". For example, "a compound" is intended to include "at least one compound" or "one or more compounds".
[0067] Any range indicated by either absolute or approximate terms is intended to cover both, and any definitions used herein are intended to be clarifying and not limiting. Numerical ranges and parameters setting forth the broad scope of the invention are approximations, although the numerical values set forth in specific examples are reported as accurately as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective test measurements. Further, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein (including all fractional and whole values).
[0068] Any composition disclosed herein can comprise, consist of, or consist essentially of any of the elements, components, and / or ingredients disclosed herein, or any combination of two or more of the elements, components, or ingredients disclosed herein.
[0069] Any method disclosed herein may include, consist of, or consist essentially of any method step disclosed herein, or any combination of two or more of the method steps disclosed herein.
[0070] The transitional term "comprising", which is synonymous with "including", "containing", or "characterized by", is inclusive or open-ended and does not exclude additional, unrecited elements, components, ingredients, and / or method steps.
[0071] The transitional term "consisting of" excludes any element, component, ingredient, and / or method step not specified in the claims.
[0072] The transitional term "consisting essentially of" limits the claims to the specified elements, components, ingredients and / or steps and those that do not substantially affect the basic and novel characteristics of the claimed invention.
[0073] Unless otherwise specified, all molecular weights referred to herein are weight average molecular weights, and all viscosities are measured at 25 °C using neat (undiluted) polymers.
[0074] As used herein, the term "about" refers to a quoted value that is within the error resulting from the standard deviation found in their respective test measurements, and where such error cannot be determined, "about" can refer to, for example, within 5% of the quoted value.
[0075] Furthermore, the present invention encompasses any and all possible combinations of some or all of the various embodiments described herein. It is also to be understood that various changes and modifications to the preferred embodiments of the invention described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. Accordingly, such changes and modifications are intended to be covered by the appended claims.
Claims
1. A composition for inhibiting monomer polymerization, comprising: a first inhibitor compound comprising a stable nitroxide radical or a derivative thereof; a second inhibitor compound comprising a phenothiazine or a derivative thereof; and a functional solvent comprising an anti-fouling agent selected from the group consisting of substituted imidazoline, phthalate, sulfone, and combinations thereof.
2. The first inhibitor compound is of formula (I): 【Chemical 1】 or a derivative thereof, wherein R is hydrogen, oxygen, C １ -C ２０ alkyl, hydroxyl, C １ -C ２０ alkoxyl, amino, amide, C １ -C ２０ ester, and C １ -C ２０ carboxylate, and each of R １ , R ２ , R ３ , and R ４ is independently a C １ -C ２０ alkyl group, the composition according to claim 1.
3. R １ 、 R ２ 、 R ３ 、 and R ４ The composition according to claim 2, wherein each of
4. The first inhibitor compound is [Chemical 2] 【Chemical Formula 3】 and the composition according to claim 1, selected from the group consisting of combinations thereof.
5. The second inhibitor compound is phenothiazine: [Chemical Formula 4] and the composition according to any one of claims 1 to 4.
6. The second inhibitor compound is a phenothiazine derivative of formula (II), [Chemical Formula 5] Wherein, R ５ is selected from the group consisting of hydrogen, alkyl, amine, aryl, and heteroaryl, and R ６ is H, Cl, CF ３ , and COCH ３ The composition according to any one of claims 1 to 4, which is selected from the group consisting of.
7. The second inhibitor compound is 【Chemical Formula 6】 and the composition according to any one of claims 1 to 4, selected from the group consisting of combinations thereof.
8. The imidazoline is selected from the group consisting of tall oil hydroxyethyl imidazoline and oleic acid hydroxyethyl imidazoline, and the composition according to any one of claims 1 to 7.
9. wherein the phthalate is C １ to C ２０ The composition according to any one of claims 1 to 7, which is a phthalate.
10. The phthalate is selected from the group consisting of dimethyl phthalate and dibutyl phthalate, and the composition according to any one of claims 1 to 7.
11. One or more hydrogens in the sulfone may be substituted by halogen, alkyl, or amine, and the composition according to any one of claims 1 to 7.
12. The sulfone is selected from the group consisting of tetramethylene sulfone, and the composition according to any one of claims 1 to 7.
13. The composition according to any one of claims 1 to 12, further comprising an additional solvent selected from the group consisting of water, ester, aromatic compound, aliphatic compound, amide, acylamide, alcohol, liquid polymer, and combinations thereof.
14. The functional solvent comprises tetramethylene sulfone, water, and dimethyl phthalate, and the composition according to any one of claims 1 to 12.
15. The first inhibitor compound is present in the composition at a concentration of about 5% to about 40% by weight, and the second inhibitor compound is present in the composition at a concentration of about 5% to about 25% by weight, and the composition according to any one of claims 1 to 14.
16. The composition according to any one of claims 1 to 15, wherein the first inhibitor compound and the second inhibitor compound are present in combination at a concentration of about 1% to about 99% by weight.
17. The composition according to any one of claims 1 to 16, wherein the first inhibitor compound and the second inhibitor compound are present in a molar ratio or weight ratio of about 0.1:1 to about 10:
1.
18. The composition according to any one of claims 1 to 17, wherein the functional solvent is present at a concentration of about 1% to about 99% by weight.
19. The composition according to any one of claims 1 to 18, further comprising methacrylic acid, methyl methacrylate, methacrylamide sulfate, or a combination thereof.
20. A method for inhibiting the polymerization of a monomer, the method comprising: adding the composition according to any one of claims 1 to 18 to the monomer.
21. The method according to claim 20, wherein the monomer is provided in a solution.
22. The method according to claim 21, wherein the solution further comprises one or more additional components selected from an acid, an organic solvent, and water.
23. The method according to any one of claims 20 to 22, wherein the monomer is an ethylenically unsaturated monomer.
24. The method according to any one of claims 20 to 23, wherein the composition is added to the monomer such that the combined concentration of the first inhibitor compound and the second inhibitor compound is from about 0.1 ppm to about 10,000 ppm.
25. The method according to any one of claims 20 to 24, wherein the monomer is selected from the group consisting of methyl methacrylate, acrylic acid, acrylic esters, methacrylamide sulfate, acrolein, acrylates, methacrylates, vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof.
26. The method according to any one of claims 20 to 23, wherein the composition is added to the monomer such that the combined concentration of the first inhibitor compound and the second inhibitor compound is from about 10 ppm to about 5,000 ppm.
27. The method according to any one of claims 20 to 24 and 26, wherein the monomer is selected from the group consisting of methacrylic acid, methyl methacrylate, methacrylamide sulfate, or a combination thereof.
28. Formula (I): [Chemical Formula 7] An inhibitor compound that is of or a derivative thereof, wherein R is hydrogen, oxygen, C １ -C ２０ alkyl, hydroxyl, C １ -C ２０ alkoxyl, amino, amide, C １ -C ２０ ester, and C １ -C ２０ carboxylate, and each of R １ , R ２ , R ３ , and R ４ is independently a C １ -C ２０ alkyl group, an inhibitor compound, and A composition comprising a functional solvent selected from the group consisting of optionally substituted imidazoline, phthalate, sulfone, and combinations thereof.
29. The inhibitor compound is 【Chemical 8】 or a derivative thereof, and the functional solvent comprises dimethyl phthalate and optionally an optionally substituted imidazoline or tetramethylene sulfone, the composition according to claim 28.
30. An inhibitor compound which is a phenothiazine derivative of formula (II), 【Chemical Formula 9】 In the formula, R ５ is selected from the group consisting of hydrogen, alkyl, amine, aryl, and heteroaryl, and R ６ is selected from the group consisting of H, Cl, CF ３ , and COCH ３ , and an inhibitor compound A composition comprising a functional solvent selected from the group consisting of optionally substituted imidazoline, phthalate, sulfone, and combinations thereof.
31. The inhibitor compound is 【Chemical 10】 and the functional solvent comprises dimethyl phthalate and optionally an optionally substituted imidazoline or tetramethylene sulfone, the composition according to claim 30.
32. A method for inhibiting the polymerization of a monomer, the method comprising adding the composition according to any one of claims 28 to 31 to the monomer.