Synergistic fouling inhibitor composition and method of using the same
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ECOLAB USA INC
- Filing Date
- 2023-07-06
- Publication Date
- 2026-06-24
AI Technical Summary
Conventional polymerization inhibitors, such as HTEMPO and OTEMPO, deteriorate in acidic environments, leading to ineffective polymerization inhibition, and phenothiazine solutions are prepared at low concentrations due to solubility issues, failing to adequately prevent fouling in methacrylic acid production processes.
A composition comprising phenothiazine or its derivatives and phenylenediamine or its derivatives, combined with specific solvents like pyrrolidone and phthalates, effectively inhibits the polymerization of ethylenically unsaturated monomers, including (meth)acrylic acid, methyl methacrylate, and others, even under acidic conditions.
The composition demonstrates synergistic polymerization inhibition, maintaining effectiveness under acidic conditions, reducing fouling and equipment contamination, and improving production efficiency by preventing premature polymerization.
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 phenothiazine and phenylenediamine, useful for inhibiting the polymerization of ethylenically unsaturated monomers in a solvent. The present disclosure further relates to a method of preparing a composition having phenothiazine or a derivative thereof, and phenylenediamine 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, can be present in the process stream or in the purified products produced by various chemical industry processes. However, these monomer types can undesirably polymerize through radical polymerization, especially at elevated temperatures in the presence of a polymerization initiator. As a result, solid deposits of the polymer can form on the surfaces of process equipment during industrial manufacturing, processing, handling, or storage. The resulting polymer 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 in an acidic environment, reducing their effectiveness as polymerization inhibitors. Therefore, there is a need to develop new polymerization inhibitors, particularly inhibitors that are stable under acidic conditions.
[0004] Methyl methacrylate plants are troubled by fouling problems that can occur in the methacrylic acid (MAA) production, esterification unit, purification unit, and waste acid unit. Phenothiazine (PTZ) solutions are typically prepared at low concentrations due to insufficient solubility, but a concentrated formulation is required to improve fouling prevention applications.
Means for Solving the Problems
[0005] A composition for inhibiting the polymerization of monomers is disclosed herein. The composition includes a first inhibitor compound having phenothiazine or a derivative thereof, a second inhibitor compound having phenylenediamine or a derivative thereof, and a solvent selected from the group consisting of pyrrolidone, an ester that is a phthalate, C3-C 10 , preferably C5-C 10 ethers, such as butyl carbitol, or 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.
[0006] In some embodiments, the first inhibitor compound has the formula (I):
Chemical formula
[0007] In some embodiments, the second inhibitor compound is a phenylenediamine of formula (II),
Chemical formula
[0008] In some embodiments, the solvent is selected from the group consisting of pyrrolidone, an ester that is a phthalate, C3-C 10 , preferably C5-C 10 ether, such as butyl carbitol, and combinations thereof.
[0009] 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 inhibition of polymerization than the individual components present in the composition and control the dosage of the active ingredient.
[0010] In some embodiments, the compositions of the present disclosure, unlike conventional polymerization inhibitors known in the art, are active even under acidic conditions. Thus, in some embodiments, the compositions of the present disclosure also contain one or more acids.
[0011] Methods of inhibiting the polymerization of monomers are also disclosed herein. A method of inhibiting the polymerization of monomers includes the step of adding a composition of the present disclosure to the monomer. The addition of the polymerization inhibitor composition of the present disclosure to the monomer inhibits the polymerization of the monomer.
[0012] The foregoing has outlined the features and technical advantages of the present disclosure in order that the following description of the invention may be better understood. Additional 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 can 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.
Best Mode for Carrying Out the Invention
[0013] 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 explicitly described herein.
[0014] 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 phenothiazine or a derivative thereof and at least one compound having a phenylenediamine or a derivative thereof in a solvent. The polymerization inhibitor composition can be a blend of a plurality of components including, in addition to the aforementioned compounds having a phenothiazine or a derivative thereof and a phenylenediamine or a derivative thereof, components.
[0015] 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 the polymer occurs at a rate substantially the same as the rate at which it would form in the absence of the polymerization inhibitor.
[0016] 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.
[0017] 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.
[0018] The composition of the present disclosure The present disclosure relates to a composition for inhibiting monomer polymerization, which comprises a first inhibitor compound having a phenothiazine or a derivative thereof and a second inhibitor compound having a phenylenediamine or a derivative thereof in a 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, but not limited to, (meth)acrylic acid, methyl methacrylate, acrylic acid, acrylate esters, methacrylamide sulfate, vinyl acetate, acrylonitrile, acrolein, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, and combinations thereof.
[0019] In some embodiments, the first inhibitor compound having a phenothiazine is a compound of formula (I),
Chemical formula
[0020] In some embodiments, the second inhibitor compound having a phenylenediamine or a derivative thereof is a compound of formula (II),
Chemical formula
[0021] In some embodiments, the first inhibitor compound having phenothiazine or a derivative thereof is
Chemical formula
[0022] In some embodiments, the second inhibitor compound having phenylenediamine or a derivative thereof is N,N-di-s-butyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-phenylenediamine, and a compound selected from the group consisting of combinations thereof.
[0023] In certain embodiments, other inhibitors such as antioxidants can be added and / or present in the compositions disclosed herein. Polymerization inhibitors such as HTEMPO can also be added, and in some embodiments, they are added as a separate stream. Dispersants such as tall oil fatty acid or oleic acid imidazoline can also be added and / or present in the compositions disclosed herein. In certain embodiments, the composition can further comprise an antioxidant. In certain aspects, all of the fouling prevention compounds can be blended and added in a single stream.
[0024] In some embodiments, the solvent is pyrrolidone, an ester that is a phthalate, C3-C 10 , preferably C5-C 10It may contain ether, such as butyl carbitol, or a combination thereof. In certain embodiments, the pyrrolidone contains N-methylpyrrolidine (CAS number 120-94-5).
[0025] In some embodiments, the pyrrolidine is of formula (III),
Chemical formula
[0026] In some embodiments, the pyrrolidine is of formula (IIIa).
Chemical formula
[0027] In some embodiments, the pyrrolidone is selected from the group consisting of N-methyl-2-pyrrolidone, 3-hydroxy-2-pyrrolidinone, 1-butylpyrrolidin-2-one, and combinations thereof.
[0028] In some embodiments, the phthalate is C1-C 20 The phthalate, for example, by way of example and not limitation, is dimethyl phthalate or dibutyl phthalate.
[0029] In some embodiments, the composition unexpectedly demonstrates a synergistic effect, and the combination of the first and second inhibitor compounds results in a greater degree of polymerization inhibition than expected for the combination.
[0030] In some embodiments, the first inhibitor compound having a phenothiazine 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 phenothiazine 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 phenothiazine 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 phenothiazine 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 phenothiazine 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 phenothiazine 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 phenothiazine or a derivative thereof is present at a concentration of about 5% to about 40 wt%.
[0031] For example, in certain embodiments, the first inhibitor compound having a phenothiazine 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%, or about 60 wt%. In certain embodiments, the first inhibitor compound having a phenothiazine or a derivative thereof comprises from at least 2 wt% of PTZ, at least 3 wt% of PTZ, at least 5 wt% of PTZ, at least 10 wt% or more of PTZ, up to a maximum of 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, or 60 wt% of PTZ.
[0032] In some embodiments, the second inhibitor compound having a phenylenediamine 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 second inhibitor compound having a phenylenediamine or a derivative thereof is present in the composition at a concentration of about 0.01 wt% to about 10 wt%.
[0033] For example, in certain embodiments, the second inhibitor compound having a phenylenediamine 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%, or about 20 wt%.
[0034] In some embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is from about 100:0.01 to about 0.01:100. In some embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine 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 phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is from about 10:1 to about 1:10. In some embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is from about 5:1 to about 1:5. In some embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is about 1:1.
[0035] In certain embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is from about 0.5:1 to about 5:1.
[0036] In certain embodiments, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is about 2:1 or about 8.85:1. By way of example and not limitation, the molar ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof can be about 2:1 or about 8:1.
[0037] In some embodiments, the weight ratio of a first inhibitor compound having phenothiazine or a derivative thereof to a second inhibitor compound having phenylenediamine or a derivative thereof is about 8:1.
[0038] In some embodiments, the solvent is 1 wt% to 99 wt% of the composition. In some embodiments, the solvent is 1 wt% to 90 wt% of the composition. In some embodiments, the solvent is 1 wt% to 80 wt% of the composition. In some embodiments, the solvent is 1 wt% to 70 wt% of the composition. In some embodiments, the solvent is 1 wt% to 60 wt% of the composition. In some embodiments, the solvent is 1 wt% to 50 wt% of the composition. In some embodiments, the solvent is 1 wt% to 40 wt% of the composition. In some embodiments, the solvent is 1 wt% to 30 wt% of the composition. In some embodiments, the solvent is 1 wt% to 20 wt% of the composition. In some embodiments, the solvent is 1 wt% to 10 wt% of the composition. In some embodiments, the solvent is 1 wt% to 5 wt% of the composition.
[0039] For example, in certain embodiments, the 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, by way of example and not limitation, the same as that used in a manufacturing process such as a (meth)acrylate manufacturing process.
[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] In some embodiments, the composition does not include phenol, nitroxyl radicals, nitroso group compounds, or hydroquinone.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] Methods of Using the Compositions of the Present Disclosure The present disclosure also relates to a method of inhibiting the polymerization of a monomer, which includes adding the 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, and the effective amount is any amount sufficient to inhibit the polymerization of the monomer.
[0047] 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.
[0048] 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 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.
[0049] 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".
[0050] In some embodiments, the monomer solution also includes one or more additional components selected from acids, organic solvents, water, and combinations thereof. For example, in some embodiments, the monomer solution includes one or more organic solvents selected from vinyl acetate, dimethyl phthalate, dimethylformamide, toluene, xylene, high-aromatic naphtha, acetonitrile, ethyl acetate, acetone, dichloromethane, tetrahydrofuran, hexane, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and combinations thereof. In some embodiments, the monomer solution includes 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 includes water.
[0051] 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 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.
[0052] 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 2,000 ppm.
[0053] 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 acrylonitrile, acrylic acid, methyl methacrylic acid and its esters, and acrylates which may include but are not limited to vinyl acetate.
[0054] The method of the present disclosure is also useful for preventing premature polymerization of styrene during the manufacturing and purification processes.
[0055] 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.
[0056] In some embodiments, the compositions of the present disclosure may include a first inhibitor compound in any solvent disclosed or contemplated herein. In other embodiments, the compositions of the present disclosure may include a second inhibitor compound in a solvent disclosed or contemplated herein. It should be further understood that in some embodiments, 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 solvents of the present disclosure.
[0057] In some embodiments, the compositions of the present disclosure
Chemical formula
Chemical formula
Chemical formula
Chemical formula
Chemical formula
Chemical formula
Chemical formula
[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 easily 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 differences in reactivity between the monomers, the inhibitors cannot efficiently reduce or mitigate 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), dimethyl phthalate (DMP) was tested to evaluate the solubility of methyl methacrylate (MMA) deposits from the field. Briefly, the solvent was tested by placing a sample of MMA foulant particles in DMP for 30 minutes to several hours and observing at both the start and after that time of the experiment. The dispersion of the foulant without precipitate demonstrated the effectiveness of the solvent for removing the foulant by gradually dissolving the formed foulant and reducing the fouling problem.
[0062] Example 2: Fouling Prevention Performance Test The fouling prevention performance test was conducted by the test tube method. Briefly, 30 mL of purified monomer (methacrylic acid) was added to a test tube together with a small amount of benzoyl peroxide (BPO) (400 ppm), then the fouling prevention formulation was added, nitrogen was blown into the liquid to remove oxygen from the liquid, and then the test tube was sealed tightly and heated at 125°C for 3 hours.
[0063] They were PTZ, HQ, PDA, and PTZ / PDA (phenothiazine / N-N-di-s-butyl-p-phenylenediamine) (from left to right) at a total of 70 ppm (equal parts of 35 ppm each when PTZ / PDA was mixed).
[0064] When polymerization occurred, the liquid became turbid, the formed polymer aggregated and precipitated to the bottom. The combination of PTZ / PDA showed the best performance without visible polymer in the flow, followed by PTZ, while HQ and PDA (N,N-di-s-butyl-p-phenylenediamine) alone were not efficient.
[0065] 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 particular 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 in a different way, 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".
[0066] Any range given in terms of 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 subranges subsumed therein (including all fractional and whole values).
[0067] Any composition disclosed herein can contain, 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.
[0068] 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.
[0069] 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, materials, and / or method steps.
[0070] The transitional term “consisting of” excludes any element, component, material, and / or method step not specified in the claims.
[0071] The transitional term “consisting essentially of” limits the claims to the specified elements, components, materials and / or steps and those that do not materially affect the basic and novel characteristics of the claimed invention.
[0072] 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.
[0073] 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 their errors cannot be determined, “about” can refer to, for example, within 5% of the quoted value.
[0074] 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 present 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, wherein the composition is A first inhibitor compound comprising phenothiazine or a derivative thereof, A second inhibitor compound comprising phenylenediamine or a derivative thereof, Pyrrolidone, phthalate ester, C ３ ~C １０ Preferably C ５ ~C １０ A composition comprising a solvent containing a fouling remover selected from the group consisting of ethers, such as butyl carbitol, and combinations thereof.
2. The first inhibitor compound or its derivative is of formula (I), 【Chemistry 1】 In the formula, R １ is selected from the group consisting of H and C １ ~C ８ alkyl groups, and R ２ is selected from the group consisting of H, C １ ~C ２０ alkyl, hydroxyl, amino, amide, ester, and carboxylate, the composition according to claim 1.
3. The first inhibitor compound or its derivative is 【Chemistry 2】 The composition according to claim 1, selected from the group consisting of and combinations thereof.
4. The second inhibitor compound or derivative thereof is of formula (II), 【Transformation 3】 In the formula, R ３ , R ４ , R ５ , and R ６ Each of them independently produces hydrogen and C １ ~C １０ Alkyl, C １ ~C １０ Ariel, C １ ~C １０ Heteroaryl, hydroxyl, C １ ~C １０ The composition according to claim 1, selected from the group consisting of alkoxyls, esters, and carboxylates.
5. The composition according to any one of claims 1 to 4, wherein the second inhibitor compound is selected from the group consisting of N,N-di-s-butyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, and N-(1,4-dimethylpentyl)-N'-phenyl-1,4-phenylenediamine.
6. The solvent comprises pyrrolidone of formula (III), 【Chemistry 4】 In the formula, R ７ However, hydrogen, C １ ~C ８ Selected from the group consisting of alkyl, aryl, and heteroaryl, R ８ However, hydrogen, C １ ~C ８ The composition according to any one of claims 1 to 4, selected from the group consisting of alkyl, aryl, and heteroaryl, wherein n is 0, 1, 2, 3, or 4.
7. The solvent comprises pyrrolidone of formula (IIIa), 【Transformation 5】 In the formula, R ７ However, hydrogen, C １ ~C ８ A composition according to any one of claims 1 to 4, selected from the group consisting of alkyl, aryl, and heteroaryl.
8. The composition according to claim 6, wherein the pyrrolidone is selected from the group consisting of N-methyl-2-pyrrolidone, 3-hydroxy-2-pyrrolidinone, 1-butylpyrrolidine-2-one, and combinations thereof.
9. The composition according to any one of claims 1 to 4, wherein the solvent comprises a phthalate, and the phthalate is selected from the group consisting of dimethyl phthalate.
10. The composition according to any one of claims 1 to 4, wherein the solvent comprises butyl carbitol.
11. The composition according to any one of claims 1 to 4, wherein the first inhibitor compound is present in the composition at a concentration of about 0% to about 50% by weight, and the second inhibitor compound is present in the composition at a concentration of about 0% to about 20% by weight.
12. The composition according to any one of claims 1 to 4, wherein the composition does not contain phenol, nitroxyl radical, nitroso group compound, or hydroquinone.
13. The composition according to any one of claims 1 to 4, further comprising monomers selected from the group consisting of (meth)acrylic acid, methyl methacrylate, acrylic acid, acrylic acid ester, methacrylamide sulfate, vinyl acetate, acrylonitrile, acrolein, acrylate, methacrylate, 1,3-butadiene, styrene, isoprene, and combinations thereof.
14. A method for inhibiting monomer polymerization, wherein the method is A method comprising adding the composition according to any one of claims 1 to 4 to the monomer.
15. The method according to claim 14, wherein the monomer is provided in a solution.
16. The method according to claim 14, wherein the monomer is an ethylenically unsaturated monomer.
17. The method according to claim 14, wherein the composition is added to the monomer such that the combined concentration of the first inhibitor compound and the second inhibitor compound is about 0.1 ppm to about 10,000 ppm.
18. The method according to claim 14, wherein the monomer is selected from the group consisting of (meth)acrylic acid, methyl methacrylate, acrylic acid, acrylic acid ester, methacrylamide sulfate, vinyl acetate, acrylonitrile, acrolein, acrylate, methacrylate, 1,3-butadiene, styrene, isoprene, and combinations thereof.
19. An inhibitor compound which is a phenothiazine derivative of formula (II), 【Transformation 6】 In the formula, R ５ However, R is selected from the group consisting of hydrogen, alkyl, amine, aryl, and heteroaryl. ６ However, H, Cl, CF ３ , and COCH ３ An inhibitor compound selected from the group consisting of, Pyrrolidone, phthalate ester, C ３ ~C １０ Preferably C ５ ~C １０ A composition comprising a solvent selected from the group consisting of ethers, for example, butyl carbitol.
20. The composition according to claim 19, wherein the solvent is N-methyl-2-pyrrolidone.
21. A method for inhibiting monomer polymerization, wherein the method is A method comprising adding the composition according to claim 19 or 20 to the monomer.