Shelf-life and transport stabilizers for polymerizable compounds.

Abstract

General formula (II) TIFF2023503208000028.tif60166 (in the formula, R 6 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 Alkyl groups include alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl. phenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 7 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20alkyl group, phenyl, carboxylic acid ester having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3, 4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with C1 to C6 alkyl, wherein C1 to C6 alkyl includes a straight or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 8 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20alkyl group, phenyl, carboxylic acid ester having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, and mixtures comprising one or more compounds of (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, including one or more of the following: phenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a straight-chain or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl.

Description

[Technical Field]

[0001] Chemical compounds containing one or more ethylenically unsaturated groups have a significant tendency to undergo free radical polymerization. Such compounds are therefore referred to as polymerizable compounds. The tendency of these compounds to undergo free radical polymerization means that they can be used as monomers to produce polymers, for example, through intentional free radical polymerization. However, the significant tendency of these compounds to undergo free radical polymerization is also a disadvantage in that undesirable spontaneous free radical polymerization can occur during storage and transportation, and also during chemical and / or physical processing, especially under the influence of energy, such as heat and / or light, for example, by distillation or rectification. Such uncontrollable polymerization can cause the gradual formation of polymer deposits, for example, on heated surfaces, which requires their removal, thereby reducing working time or even causing explosions. [Background technology]

[0002] It is therefore common practice to add substances that prevent or interfere with undesired spontaneous free-radical polymerization during storage and transport, as well as during chemical and / or physical processing, of ethylenically unsaturated compounds that have a tendency to free-radical polymerization, or mixtures containing such compounds. Such substances are generally and hereinafter referred to as polymerization inhibitors or polymerization stabilizers.

[0003] The polymerization stabilizer can be used in the form of an individual chemical compound or a mixture of compounds. Depending on the field of use, the polymerization stabilizer may have specific requirements. For example, for a polymerization stabilizer suitable as a stabilizer for transporting and storing ethylenically unsaturated compounds, it is important to be able to adjust the efficiency of the polymerization stabilizer, i.e., the degree of stabilization or inhibition of polymerization. Under the storage and / or transport conditions of the ethylenically unsaturated compounds, the polymerization stabilizer should sufficiently prevent or inhibit undesired spontaneous free radical polymerization, while the desired free radical polymerization of the ethylenically unsaturated compounds should be able to occur under appropriate polymerization conditions without the need to separate the polymerization stabilizer that is first used during storage and / or transport. It is important that the stabilizers used during storage and / or transportation do not have side effects during the desired polymerization if they are not separated out during the desired polymerization or act unintentionally as chain transfer agents (for information on polymerization chain transfer agents, see, for example, Ullmann's Encyclopedia of Industrial Chemistry, Polymerization Processes, 1. Fundamentals, 6 Free-Radical Polymerization, DOI 10.1002 / 14356007.21_305.pub3 or Ullmann's Encyclopedia of Industrial Chemistry, Polyacrylates, 4.1.1 Starting Materials, DOI 10.1002 / 14356007.a21_157.pub2).

[0004] In terms of global production, acrylic acid is undoubtedly one of the most important ethylenically unsaturated compounds. Typically, acrylic acid is stabilized against undesired spontaneous free-radical polymerization during storage and / or transport using 180 to 220 ppm by weight of hydroquinone monomethyl ether (MEHQ) based on the amount of acrylic acid. For adequate stabilization of acrylic acid against undesired spontaneous free-radical polymerization using MEHQ, it is essential that oxygen be dissolved in the acrylic acid in sufficient amounts. A sufficient amount of oxygen is typically dissolved in the acrylic acid when the acrylic acid is stored and / or transported under an atmosphere containing 5 to 21 vol% oxygen. Stabilization of acrylic acid with MEHQ during transport and / or storage is described, for example, in Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 6.1 Instability and Reactivity—Polymerization and 7.1. Bulk Storage Facilities and Accessories—General Considerations. In the desired polymerization of acrylic acid, e.g., to form polyacrylate, the dissolved oxygen content of the acrylic acid is reduced, thereby reducing the efficiency of MEHQ as a polymerization stabilizer, whereby acrylic acid is subjected to polymerization in the presence of MEHQ.

[0005] In addition to its use as a polymerization stabilizer during storage and / or transportation of acrylic acid, MEHQ is also used as a polymerization stabilizer during storage and / or transportation of methacrylic acid, acrylic acid esters, methacrylic acid esters, or mixtures containing one or more of the foregoing compounds. Acrylic acid or methacrylic acid will hereinafter be referred to as (meth)acrylic acid, and its esters will hereinafter be referred to as (meth)acrylic acid esters.

[0006] Due to its wide range of applications, MEHQ is one of the most important storage and / or transport stabilizers for polymerizable compounds in general, and for (meth)acrylic acid and (meth)acrylic acid esters in particular.

[0007] The polymerizable compound is stored in a suitable permanently installed container, such as a storage tank or other suitable storage vessel (see, for example, Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 7, Bulk Storage Facilities and Accessories). The storage of the polymerizable compound in each container is preferably at least 1 minute, more preferably at least 10 minutes, and particularly preferably at least 60 minutes. While the duration of storage under appropriate conditions is theoretically unlimited, the duration of storage is generally minimized for economic reasons. The storage of the polymerizable compound in each container is preferably at most 180 days, more preferably at most 90 days, and particularly preferably at most 30 days. Particularly preferred ranges result from any combination of the lower and upper range limits set forth above.

[0008] Transport of the polymerizable compound by ship, rail, and / or truck is usually in a suitable transportable container, such as a tank or other suitable vessel (see, for example, Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 9, Safe Transport of Acrylic Acid). The transportable container may, of course, be permanently installed, such as a tank in a ship or rail tanker. The container may, of course, be stored at a specific location for a certain period of time before being transported to another location. Transport of the polymerizable compound may be by pipeline or hose to a storage tank, for example, after purification of the polymerizable compound, during filling of the storage tank into a transportable container, and / or during filling of one transportable container into another. Transport of the polymerizable compound in each container is preferably for 10 seconds or more, more preferably 1 minute or more, particularly preferably 10 minutes or more, and most preferably 60 minutes or more. Although the duration under appropriate conditions is theoretically unlimited, the duration is generally reduced to a minimum for economic and safety reasons. The delivery time of the polymerizable compound in each container is preferably 180 days or less, more preferably 90 days or less, and particularly preferably 30 days or less. Particularly preferred ranges result from any combination of the lower and upper range limits stated above. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US 6 046 357 [Patent Document 2] DE 10 2012 223 695 A1 [Non-patent literature]

[0010] [Non-Patent Document 1] Ullmann's Encyclopedia of Industrial Chemistry, Polymerization Processes, 1. Fundamentals, 6 Free-Radical Polymerization, DOI 10.1002 / 14356007.21_305.pub3 [Non-patent document 2] Ullmann's Encyclopedia of Industrial Chemistry, Polyacrylates, 4.1.1 Starting Materials, DOI 10.1002 / 14356007.a21_157.pub2 [Non-patent document 3] Acrylic Acid, A Summary of Safety and Handling, 4th edition, 2013, 6.1 Instability and Reactivity-Polymerization [Non-patent document 4] Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 7.1. Bulk Storage Facilities and Accessories-General Considerations [Non-patent document 5] Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 7, Bulk Storage Facilities and Accessories [Non-patent document 6] Acrylic Acid, A Summary of Safety and Handling, 4th Edition, 2013, 9, Safe Transport of Acrylic Acid [Non-Patent Document 7] The Chemistry of Radical Polymerisation, 2nd edition, 2005, pp. 49-166 Summary of the Invention [Problem to be solved by the invention]

[0011] To reduce reliance on MEHQ, it was an object of the present invention to provide a mixture comprising (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate and one or more storage and / or transport stabilizers. The storage and / or transport stabilizers should ensure sufficient stabilization of the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate against undesired free radical polymerization. Furthermore, it would also be advantageous if, in the desired free radical polymerization, there was no need to separate the storage and / or transport stabilizers from the mixture prior to polymerization. The storage and / or transport stabilizers should therefore not act as chain transfer agents and / or inhibitors in the desired free radical polymerization.

[0012] In the context of the present invention, the compounds are suitable as storage and / or transport stabilizers for (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates, provided that said compounds, under comparable conditions, a) inhibits spontaneous free radical polymerization of liquid acrylic acid stored in an atmosphere containing 5 to 30 vol% oxygen with an efficiency of 75 percent or greater relative to the efficiency of an equimolar amount of MEHQ; and b) It inhibits the free radical polymerization of liquid acrylic acid stored in an atmosphere containing 96 to 100 vol% nitrogen and to which 1,000 to 15,000 ppm by weight of polymerization initiator is added with an efficiency of 130 percent or less, relative to the efficiency of an equimolar amount of MEHQ, and does not act as a chain transfer agent and / or inhibitor in the desired free radical polymerization, provided that an equivalent or similar polymer is obtained after polymerization. The nitrogen content of the atmosphere is preferably 99 to 100 vol%.

[0013] In a) and b), MEHQ is in each case used in an amount of 10 to 250 ppm by weight, preferably 35 to 45 ppm by weight, the values ​​in ppm by weight being relative to the amount of liquid acrylic acid used.

[0014] Equivalent or similar polymers are obtained when the polymers have approximately the same weight averages (measured according to the same GPC method). Approximately the same weight averages exist when the weight averages are within 20 percent of each other.

[0015] Polymerization initiators customarily used for the polymerization of (meth)acrylic acid and known to those skilled in the art (see, for example, The Chemistry of Radical Polymerization, 2nd edition, 2005, pages 49 to 166) are suitable as polymerization initiators. [Means for solving the problem]

[0016] The object is to provide a compound of general formula (II)

[0017] [ka]

[0018] (In the formula, R 6 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20Alkyl groups include alkanoyl having C1 to C8 alkyl, where C1 to C8 alkyl is a straight or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl. nyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 7 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20alkyl group, phenyl, carboxylic acid ester having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4- dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 8 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20and alkanoyl having C1 to C8 alkyl, wherein the C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein the C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4 2-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is achieved by one or more compounds of a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl), and a mixture comprising (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0019] C1 to C8 alkyl includes linear or branched C1 to C8 alkyl groups or cyclic C3 to C8 alkyl groups. Examples of C1 to C8 alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, cyclopentyl, n-hexyl, cyclohexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 2-methylhexyl, 2-ethylpentyl, 4-methylcyclohexyl, n-octyl, isooctyl or 2-ethylhexyl.

[0020] The present invention further provides the use of one or more compounds of general formula (II) as storage and / or transport stabilizers for (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates.

[0021] The present invention further provides a method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates during transportation and / or storage through the use of one or more compounds of general formula (II).

[0022] The present invention also provides a process for polymerizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates in the presence of one or more compounds of general formula (II).

[0023] The mixtures according to the invention are liquid under standard conditions.

[0024] explanation: General formula (I)

[0025] [ka]

[0026] In the compound, R 1 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20It includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 3 H, C2 to C 20 Alkyl, C2 to C 20 Alkyl is a straight or branched C2 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C2 to C8 alkyl, and more preferred alkyl groups are C2 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, and 4-isopropoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, where the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, where the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl.

[0027] In preferred compounds of general formula (I), R 1is H, C1 to C6 alkyl, C1 to C6 alkyl being a straight or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, phenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 is H or C1 to C6 alkyl, where C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group; R 3 is H.

[0028] this is, R 1is H, C1 to C6 alkyl, wherein C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, phenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group is optionally esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 is H or methyl, R 3 It is particularly preferred if is H.

[0029] The compound of general formula (I) is in equilibrium with its keto form.

[0030] [ka]

[0031] In its enol form, the compound of general formula (I) can undergo an addition reaction with (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate. In mixtures of the compound of general formula (I) with (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, the corresponding addition products can therefore be present. R 3 When is H, in addition to single addition, double addition can also occur.

[0032] The addition of (meth)acrylic acid to 5-methyl-2-phenyl-4H-pyrazol-3-one is illustrated by way of example by the addition of (meth)acrylic acid to a compound of general formula (I).

[0033] [ka]

[0034] By adding (meth)acrylic acid to 5-methyl-2-phenyl-4H-pyrazol-3-one, the (meth)acrylic acid ester can also be added to the compound of general formula (I). In addition to single addition, double addition is also conceivable.

[0035] Also disclosed are mixtures comprising one or more compounds of general formula (I) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0036] General formula (II)

[0037] [ka]

[0038] In the compound, R 6 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl. nyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 7 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20It includes an alkyl group, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, alkanoyl having C1 to C8 alkyl, and C1 to C8 alkyl is a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4-dimethylphenyl, 2-methyl ... hydroxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 8 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20It includes an alkyl group, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, alkanoyl having C1 to C8 alkyl, and C1 to C8 alkyl is a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4-dimethylphenyl, 2-methyl ... and (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a straight or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl.

[0039] In more preferred compounds of general formula (II), R 6 is H or C1 to C6 alkyl, where C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group; R 7 is H, C1 to C6 alkyl, where C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, alkanoyl having C1 to C6 alkyl, where C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group; R 8 is H or C1 to C6 alkyl, which includes a straight chain or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group.

[0040] Also disclosed are mixtures comprising one or more compounds of general formula (II) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0041] General formula (III)

[0042] [ka]

[0043] In the compound, R 9 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 It includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R10 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 11 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. and 4-isopropoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, where the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, where the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl.

[0044] Also disclosed are mixtures comprising one or more compounds of general formula (III) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0045] General formula (IV)

[0046] [ka]

[0047] In the compound, R 12 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20Alkyl group or cyclic C3 to C 20 It includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 13 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 14 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 15 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. nyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, 4-isopropoxyphenyl, NH, NH(CO)R 16 Contains R 16 is H, C1 to C6 alkyl, where C1 to C6 alkyl includes a straight or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, phenyl, tolyl, such as m- or p-tolyl, 4-methoxyphenyl or dimethylphenyl, such as 3,4-dimethylphenyl.

[0048] Also disclosed are mixtures comprising one or more compounds of general formula (IV) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0049] The C1 to C8 alkyl (meth)acrylate is preferably methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0050] The preparation of compounds of general formula (I), (II), (III) or (IV) is known to those skilled in the art or has been established by those skilled in the art on the basis of general knowledge in the art.

[0051] The total amount of compounds of general formula (I), (II), (III) or (IV) in the mixture is preferably 0.1 to 1000 ppm by weight, based on the total weight of the (meth)acrylic acid and the C1 to C8 alkyl (meth)acrylate present in the mixture. The total amount of compounds of general formula (I), (II), (III) or (IV) in the mixture is particularly preferably 1 to 900 ppm by weight, very particularly preferably 10 to 800 ppm by weight, in particular 10 to 500 ppm by weight, based in each case on the total weight of the (meth)acrylic acid and the C1 to C8 alkyl (meth)acrylate present in the mixture.

[0052] If the mixture comprises other components in addition to (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate and one or more compounds of general formula (I), (II), (III) or (IV), the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture according to the invention is preferably at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, even more preferably at least 40% by weight, even more preferably at least 50% by weight, even more preferably at least 60% by weight, even more preferably at least 70% by weight, even more preferably at least 80% by weight, even more preferably at least 90% by weight and particularly preferably at least 95% by weight, based on the total weight of the mixture.

[0053] Examples of other components are solvents, such as organic solvents, water or solvent mixtures, dissolved gases, such as air, minor components, co-stabilizers, or any desired mixture of two or more of these components.

[0054] Examples of minor components are by-products formed during the production and / or purification of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates and incompletely removed during the purification. Minor components can also be various contaminants introduced during the production, purification, and / or storage of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates. Minor components can also be introduced into the mixture in the same manner via compounds of general formula (I), (II), (III), or (IV).

[0055] Depending on the production and purification, (meth)acrylic acid may contain one or more minor components. Examples of minor components that may be present include water, di(meth)acrylic acid, acetic acid, propionic acid, one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, protoanemonin, maleic acid, maleic anhydride, allyl acrylate, or any desired mixture of two or more of the minor components. The content of the minor components is generally within the range of a detectable limit to 20,000 ppm by mass relative to the amount of (meth)acrylic acid.

[0056] The C1 to C8 alkyl (meth)acrylate may contain one or more minor components depending on the production and purification. Examples of minor components that may be present include water, (meth)acrylic acid, the alcohol of each (meth)acrylic acid ester, a propionate ester with the alcohol of each (meth)acrylic acid ester, an acetate ester with the alcohol of each (meth)acrylic acid ester, an ether of each (meth)acrylic acid ester alcohol, or any desired mixture of two or more of the minor components. The content of the minor components is generally within the range of a detectable limit to 20,000 ppm by mass relative to the amount of the (meth)acrylic acid ester.

[0057] The mixture according to the invention is preferably stored and / or transported under an oxygen-containing atmosphere, which preferably has an oxygen content of 5 to 30 vol.% oxygen, in particular 5 to 21 vol.% oxygen.

[0058] In order to achieve oxygen saturation of the mixture according to the invention as quickly as possible and / or to ensure a constant oxygen saturation, it is preferable to introduce an oxygen-containing gas into the mixture, which can be introduced, for example, via one or more nozzles positioned so that their openings reach into the mixture.

[0059] The oxygen-containing gas is, for example, air, a nitrogen-air mixture, or an oxygen-nitrogen mixture, excluding air, having an oxygen content of 5 to 30 vol. %. In addition to oxygen and nitrogen, the oxygen-nitrogen mixture may contain other gases, such as carbon dioxide, carbon monoxide, hydrogen, methane, one or more noble gases, or a mixture of two or more of the aforementioned gases.

[0060] The mixture can be produced by mixing one or more compounds of general formula (I), (II), (III), or (IV) with (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate. It may be convenient to produce a concentrate of the compound of general formula (I), (II), (III), or (IV) in (meth)acrylic acid, a C1 to C8 alkyl (meth)acrylate, and / or in a suitable solvent, and then dilute the concentrate thus obtained with (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate. The selection of a suitable solvent, which may be a solvent mixture, will be guided by general process considerations, such as solubility, miscibility, and potential side effects, as those skilled in the art. The (meth)acrylic acid and / or the C1 to C8 alkyl (meth)acrylate can be added to the concentrate, or the concentrate can be added to the (meth)acrylic acid and / or the C1 to C8 alkyl (meth)acrylate.

[0061] The mixture preferably includes a co-stabilizer. The co-stabilizer may be present in the mixture according to the present invention as an individual chemical compound or as a mixture of compounds. The co-stabilizer helps prevent or inhibit free radical polymerization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate. The co-stabilizer may act synergistically with the compound of general formula (I), (II), (III), or (IV) in preventing or inhibiting free radical polymerization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate. The co-stabilizer may be added to the mixture before and / or during storage and / or transportation. The co-stabilizer may be added to the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate together with or separately from the compound of general formula (I), (II), (III), or (IV). However, the co-stabilizer may already be added during the production and / or purification of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate, in which case the compound of general formula (I), (II), (III) or (IV) is subsequently added to the mixture.

[0062] The total amount of co-stabilizers in the mixtures according to the invention is preferably 0.1 to 5000 ppm by weight, based on the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture, more preferably 1 to 4000 ppm by weight, in particular 5 to 2500 ppm by weight, particularly preferably 50 to 750 ppm by weight, in each case based on the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture.

[0063] The amount of the costabilizer can be adjusted by adding or removing it. Methods for removing the costabilizer are known to those skilled in the art (see, for example, US Pat. No. 6,046,357). Examples of suitable methods include distillation, crystallization, ion exchange, extraction, reverse osmosis, and / or membrane processes. When selecting a suitable method or combination of methods, the skilled artisan will be guided by general knowledge in the art. When the compound of general formula (I), (II), (III), or (IV) is removed with the costabilizer, the costabilizer may optionally be replenished. When the content of the costabilizer in the mixture is reduced or eliminated, it may also be necessary to optionally increase the content of the compound of general formula (I), (II), (III), or (IV) to achieve the desired stabilization of the polymerization.

[0064] Examples of co-stabilizers are metal salts from the group of copper, manganese and cerium salts, phenothiazines, phenolic compounds, N-oxyls, phenylenediamines, nitroso compounds, urea, thiourea or mixtures of two or more of the aforementioned classes of substance. The co-stabilizers are preferably phenothiazines, phenolic compounds, N-oxyls or mixtures of two or more of the aforementioned classes of substance.

[0065] The copper salt is preferably a copper(I) and / or copper(II) salt having sufficient solubility in the polymerizable compound and in the mixture according to the invention. Examples of suitable copper salts include copper(II) phenolate, copper(II) acetylacetonate, copper(II) gluconate, copper(II) tartrate, copper(II) acetate, copper(II) formate, copper(II) nitrate, copper(II) hydroxide, copper(II) sulfate, copper(II) carbonate, copper(II) naphthenate, copper(II) acrylate, copper(II) halides such as copper(II) chloride, copper(II) salicylate, copper(II) sulfonate, copper(II) propionate, copper(II) octanoate, copper(I) chloride, copper(I) iodide, copper(I) bromide, copper(I) cyanide, copper(I) acetate, copper(I) oxide, copper(I) sulfate, copper complex salts such as Cu(NH3)4 with suitable counterions. +, ligand-stabilized copper complexes, such as those disclosed in DE 10 2012 223 695 A1, or any desired mixture of two or more of said copper salts. The copper salts can also be used in the form of their hydrates.

[0066] The manganese salt is preferably a manganese(II) salt that has sufficient solubility in the polymerizable compound and in the mixture according to the invention. Examples of suitable manganese salts include manganese(II) phenolate, manganese(II) acetylacetonate, manganese(II) gluconate, manganese(II) tartrate, manganese(II) acetate, manganese(II) formate, manganese(II) nitrate, manganese(II) hydroxide, manganese(II) sulfate, manganese(II) carbonate, manganese(II) naphthenate, manganese(II) acrylate, manganese(II) halides such as manganese(II) chloride, manganese(II) salicylate, manganese(II) sulfonate, manganese(II) propionate, manganese(II) octanoate, ligand-stabilized manganese complexes such as those disclosed in DE 10 2012 223 695 A1, or any desired mixture of two or more of the above-mentioned manganese salts. The manganese salt may also be used in the form of its hydrate.

[0067] The cerium salt is preferably a cerium(III) salt that has sufficient solubility in the polymerizable compound and in the mixture according to the invention. Examples of suitable cerium salts include cerium(III) phenolate, cerium(III) acetylacetonate, cerium(III) gluconate, cerium(III) tartrate, cerium(III) acetate, cerium(III) formate, cerium(III) nitrate, cerium(III) hydroxide, cerium(III) sulfate, cerium(III) carbonate, cerium(III) naphthenate, cerium(III) acrylate, cerium(III) halides such as cerium(III) chloride, cerium(III) salicylate, cerium(III) sulfonate, cerium(III) propionate, cerium(III) octanoate, ligand-stabilized cerium complexes such as those disclosed in DE 10 2012 223 695 A1, or any desired mixture of two or more of the above cerium salts. The cerium salt may also be used in the form of its hydrate.

[0068] Examples of phenothiazines are bis(α-methylbenzyl)phenothiazine, 3,7-dioctylphenothiazine, bis(α-dimethylbenzyl)phenothiazine or any desired mixture of two or more of said compounds.

[0069] Examples of phenolic compounds are hydroquinone, hydroquinone monomethyl ether, e.g., para-methoxyphenol (MEHQ), pyrogallol, catechol, resorcinol, phenol, cresol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-para-cresol, or any desired mixture of two or more of said compounds.

[0070] Examples of N-oxyls are di-tert-butyl nitroxide, 2,2,6,6-tetramethyl-4-hydroxypiperidyl-1-oxyl, 2,2,6,6-tetramethylpiperidyl-1-oxyl, 2,2,6,6-tetramethylpiperidineoxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidineoxyl, 4,4',4''-tris-1-(2,2,6,6-tetramethylpiperidinoxyl) phosphite, or any desired mixture of two or more of said compounds.

[0071] The present application further provides the use of one or more compounds of general formula (I), (II), (III) or (IV) as storage and / or transport stabilizers for (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates. Reference is made to all preferred embodiments already described. Embodiments that are characterized as particularly preferred, particularly highly preferred or preferred throughout the same formulation are also covered accordingly.

[0072] The present application further provides a method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates during transportation and / or storage through the use of one or more compounds of general formula (I), (II), (III) or (IV). Reference is made to all preferred embodiments already described. Embodiments characterized as particularly preferred, particularly highly preferred or preferred through similar formulations are also covered accordingly.

[0073] The method according to the invention comprises providing a mixture comprising one or more compounds of general formula (I), (II), (III) or (IV) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, the mixture being 50 to 100%, preferably 90 to 100%, more preferably 95 to 100% saturated with oxygen. The oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30% by volume, preferably having an oxygen content of 5 to 21% by volume.

[0074] The present invention also provides a process for polymerizing (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate in the presence of one or more compounds of general formula (I), (II), (III) or (IV), wherein the reaction mixture is saturated with oxygen to a level of 0 to 50%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0 to 1%, and most preferably 0 to 0.1%. The oxygen saturation refers to the oxygen saturation achieved when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30% by volume, preferably 5 to 21% by volume.

[0075] If the oxygen saturation of the reaction mixture is too high, the oxygen saturation can be reduced, for example, by introducing nitrogen into the reaction mixture and / or the atmosphere above the reaction mixture. The introduced nitrogen should be substantially oxygen-free, for example, the oxygen content is less than 1 vol. %, preferably less than 0.1 vol. %.

[0076] In addition to (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate, the reaction mixture may also contain other polymerizable compounds.

[0077] Reference is made to all preferred embodiments already described. Embodiments which are characterized as particularly preferred, particularly highly preferred or preferred through the same formulation are also covered accordingly.

[0078] The polymerization is preferably carried out at a temperature of from 50 to 150°C, more preferably from 70 to 120°C.

[0079] The polymerization is preferably carried out under a nitrogen atmosphere having a nitrogen content of 85 to 100 vol%, preferably 90 to 100 vol%, more preferably 99 to 100%. The oxygen content of the nitrogen atmosphere is less than 5 vol%.

[0080] The polymerization is preferably carried out in the presence of a polymerization initiator. Suitable polymerization initiators are those known to those skilled in the art, such as those described in The Chemistry of Radical Polymerisation, 2nd edition, 2005, pp. 49-166. The polymerization initiator is used in an effective amount.

[0081] Through the method according to the present invention, (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates, stored and / or transported and stabilized with one or more compounds of general formula (I), (II), (III), or (IV), can be polymerized without first separating the compounds of general formula (I), (II), (III), or (IV) from the reaction mixture to be polymerized. The reaction mixture can therefore be placed in the reactor used for polymerization in an initially stabilized form. By reducing the oxygen saturation in the reaction mixture, preferably by introducing nitrogen into the reactor space above the reaction mixture and / or by introducing nitrogen into the reaction mixture, the stabilizing effect of the compounds of general formula (I), (II), (III), or (IV) can be reduced to a level sufficient to allow polymerization of the reaction mixture to occur. The polymerization initiator can be added before, during, or after the reduction of oxygen saturation. For safety reasons, it is preferred if the polymerization initiator is added before the reduction of oxygen saturation. DETAILED DESCRIPTION OF THE INVENTION

[0082] The invention covers in particular the following embodiments:

[0083] 1.General formula (II)

[0084] [ka]

[0085] (In the formula, R 6 H, C1 to C 20 Alkyl, C1 to C 20Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 Alkyl groups include alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl. phenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 7 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20alkyl group, phenyl, carboxylic acid ester having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3, 4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with C1 to C6 alkyl, wherein C1 to C6 alkyl includes a straight or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 8 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20alkyl group, phenyl, carboxylic acid ester having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; alkanoyl having C1 to C8 alkyl, wherein C1 to C8 alkyl is a straight-chain or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group; cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example, 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, and mixtures comprising one or more compounds of (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, including one or more of the following: phenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a straight-chain or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl.

[0086] 2.R 6is H, C1 to C8 alkyl, wherein the C1 to C8 alkyl is a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, including alkanoyl having C1 to C8 alkyl, wherein the C1 to C8 alkyl is a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, for example 3,4-dimethylphenyl , 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 7is H, C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, phenyl, a carboxylic acid ester having a C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, an alkanoyl having a C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, phenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with C1 to C6 alkyl, wherein C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, or 4-isopropoxyphenyl; R 8is H, C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, phenyl, a carboxylic acid ester having a C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, an alkanoyl having a C1 to C8 alkyl, wherein the C1 to C8 alkyl includes a linear or branched C1 to C8 alkyl group or a cyclic C3 to C8 alkyl group, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, Mixtures according to embodiment 1, comprising 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may also be esterified with C1 to C6 alkyl, wherein C1 to C6 alkyl comprises a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl or 4-isopropoxyphenyl.

[0087] 3.R 6 is H or C1 to C6 alkyl, wherein C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group; R 7 is H, C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group; R 8is H or C1 to C6 alkyl, wherein C1 to C6 alkyl comprises a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group.

[0088] 4. The mixture according to any of embodiments 1 to 3, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0089] 5. A mixture according to any of embodiments 1 to 4, wherein the total amount of compounds of general formula (II) in the mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0090] 6. The mixture according to any of embodiments 1 to 5, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, in each case relative to the total weight of the mixture.

[0091] 7. The mixture contains (meth)acrylic acid, and the mixture contains the following components: a. 20 to 15,000 ppm by weight of water, relative to the total weight of (meth)acrylic acid present in the mixture; b. 100 to 20,000 ppm by weight of di(meth)acrylic acid, based on the total weight of (meth)acrylic acid present in the mixture c. 100 to 2000 ppm by weight of acetic acid, based on the total weight of (meth)acrylic acid present in the mixture d. 100 to 2000 ppm by weight of propionic acid, based on the total weight of (meth)acrylic acid present in the mixture e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde, relative to the total weight of (meth)acrylic acid present in the mixture; f. 0 to 2 ppm by mass of protoanemonin, based on the total mass of (meth)acrylic acid present in the mixture g. 0 to 1 ppm by weight of maleic acid, based on the total weight of (meth)acrylic acid present in the mixture h. 0 to 1 ppm by weight of maleic anhydride, based on the total weight of (meth)acrylic acid present in the mixture i. A mixture according to any of embodiments 1 to 3, or 5 or 6, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the total weight of (meth)acrylic acid present in the mixture.

[0092] 8. The mixture comprises one or more (meth)acrylic acid esters according to embodiment 4, wherein the mixture comprises the following components: a. 1 to 2000 ppm by weight of water, preferably 1 to 500 ppm by weight, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture. c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohols of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with alcohols of the respective (meth)acrylic acid esters, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture; f. A mixture according to any of embodiments 4 to 6 comprising 0 to 2000 ppm by weight of one or more ethers of respective (meth)acrylic acid ester alcohols, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 4 present in the mixture.

[0093] 9. The mixture according to any of embodiments 1 to 8, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere.

[0094] 10. The mixture according to embodiment 9, wherein the oxygen-containing atmosphere has an oxygen content of 5 to 30 vol.% oxygen, preferably 5 to 21 vol.% oxygen.

[0095] 11. The mixture according to embodiment 9 or 10, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere for at least 10 seconds, preferably at least 1 minute, more preferably at least 10 minutes, particularly preferably at least 60 minutes.

[0096] 12. The mixture according to any of embodiments 1 to 11, wherein the mixture comprises a costabilizer.

[0097] 13. The mixture according to embodiment 12, wherein the total amount of co-stabilizers present in the mixture is from 0.1 to 5000 ppm by weight, preferably from 1 to 4000 ppm by weight, in particular from 5 to 2500 ppm by weight, and more preferably from 50 to 750 ppm by weight, relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0098] 14. The mixture according to embodiment 12 or 13, wherein the co-stabilizer is a metal salt from the group consisting of copper, manganese and cerium salts, phenothiazines, phenolic compounds, N-oxyls, phenylenediamines, nitroso compounds, urea, thiourea or a mixture of two or more of the aforementioned classes of substances.

[0099] 15. Use of one or more compounds of general formula (II) as defined in any of embodiments 1 to 3 for storage and / or transport stabilization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates.

[0100] 16. Use according to embodiment 15, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0101] 17. Use according to embodiment 15 or 16, in which the compound of general formula (II) is used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, in particular 10 to 500 ppm by weight, based on the total weight of the amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate to be stabilized.

[0102] 18. (Meth)acrylic acid is stabilized and the stabilized (meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. Use according to embodiment 15 or 17, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, in each case relative to the amount of (meth)acrylic acid.

[0103] 19. One or more (meth)acrylic acid esters according to embodiment 16 are stabilized, and the stabilized (meth)acrylic acid esters are selected from the group consisting of the following components: a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 16; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 16; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 16; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 16. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 16; f. Use according to embodiment 16 or 17, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols, relative to the amount of the (meth)acrylic acid ester according to embodiment 16.

[0104] 20. A process for polymerizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates in the presence of one or more compounds of general formula (II) as defined in any of embodiments 1 to 3, wherein the reaction mixture is saturated with oxygen by 0 to 50%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0 to 1%, and most preferably 0 to 0.1%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0105] 21. The process according to embodiment 20, wherein the total amount of compounds of general formula (II) in the reaction mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the reaction mixture.

[0106] 22. The process according to embodiment 20 or 21, wherein the polymerization is carried out at a temperature of from 50 to 150°C, preferably from 70 to 120°C.

[0107] 23. The process according to any of embodiments 20 to 22, wherein the polymerization is carried out under a nitrogen atmosphere having a nitrogen content of 85 to 100 vol% and an oxygen content of less than 5 vol%, preferably a nitrogen content of 90 to 100 vol%, more preferably a nitrogen content of 99 to 100 vol%.

[0108] 24. The method according to any of embodiments 20 to 23, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0109] 25. (Meth)acrylic acid to be polymerized is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to any of embodiments 20 or 23, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate relative to the amount of (meth)acrylic acid.

[0110] 26. The (meth)acrylic acid ester to be polymerized is a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 24; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 24; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 24; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 24. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 24; f. The process according to embodiment 24, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 24.

[0111] 27. A method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates through the use of one or more compounds of general formula (II) as defined in any of embodiments 1 to 3.

[0112] 28. The method according to embodiment 27, wherein the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate is stabilized during storage and / or transportation.

[0113] 29. The method according to embodiment 27 or 28, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0114] 30. (Meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to embodiment 27 or 28, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the amount of (meth)acrylic acid.

[0115] 31. (Meth)acrylic acid ester is a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 29; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 29; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 29; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 29. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 29; f. The process according to embodiment 29, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 29.

[0116] 32. The method according to any of embodiments 27 to 31, wherein the method comprises providing a mixture comprising one or more compounds of general formula (II) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, wherein the mixture is saturated with oxygen by 50 to 100%, preferably 90 to 100%, more preferably 95 to 100%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0117] 33. The process according to embodiment 32, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the total weight of the mixture.

[0118] 34. The process according to any of embodiments 27 to 33, wherein the compounds of general formula (II) are used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, and in particular 10 to 500 ppm by weight, in each case relative to the total weight of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0119] 35.General formula (I)

[0120] [ka]

[0121] (In the formula, R 1 But H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20It includes an alkyl group, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 But H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes an alkyl group, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 3 But H, C2 to C 20 Alkyl, C2 to C 20 Alkyl is straight or branched C2 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes an alkyl group, and preferred alkyl groups are C2 to C8 alkyl, and more preferred alkyl groups are C2 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, and a mixture comprising one or more compounds of (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, wherein the carboxyl group is optionally esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl.

[0122] 36.R 1is H, C1 to C6 alkyl, wherein C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, phenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group is optionally esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 is —H or C1 to C6 alkyl; R 3 A mixture according to embodiment 35, wherein is H.

[0123] 37.R 1is H, C1 to C6 alkyl, wherein C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, phenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group is optionally esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 2 is H or methyl, R 3 A mixture according to embodiment 35, wherein is H.

[0124] 38. The mixture according to any of embodiments 35 to 37, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0125] 39. The mixture according to any of embodiments 35 to 38, wherein the total amount of compounds of general formula (I) in the mixture is 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, and in particular 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0126] 40. The mixture according to any of embodiments 35 to 39, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, in each case relative to the total weight of the mixture.

[0127] 41. A mixture comprising (meth)acrylic acid, and a. 20 to 15,000 ppm by weight of water, relative to the total weight of (meth)acrylic acid present in the mixture; b. 100 to 20,000 ppm by weight of di(meth)acrylic acid, based on the total weight of (meth)acrylic acid present in the mixture c. 100 to 2000 ppm by weight of acetic acid, based on the total weight of (meth)acrylic acid present in the mixture d. 100 to 2000 ppm by weight of propionic acid, based on the total weight of (meth)acrylic acid present in the mixture e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde, relative to the total weight of (meth)acrylic acid present in the mixture; f. 0 to 2 ppm by mass of protoanemonin, based on the total mass of (meth)acrylic acid present in the mixture g. 0 to 1 ppm by weight of maleic acid, based on the total weight of (meth)acrylic acid present in the mixture h. 0 to 1 ppm by weight of maleic anhydride, based on the total weight of (meth)acrylic acid present in the mixture i. A mixture according to any of embodiments 35 to 37, or 39 or 40, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the total weight of (meth)acrylic acid present in the mixture.

[0128] 42. The mixture comprises one or more (meth)acrylic esters according to embodiment 38, wherein the mixture comprises the following components: a. 1 to 2000 ppm by weight, preferably 1 to 500 ppm by weight, of water, in each case relative to the total weight of the (meth)acrylic esters according to embodiment 38 present in the mixture; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 38 present in the mixture; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohols of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 38 present in the mixture; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 38 present in the mixture; e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 38 present in the mixture; f. A mixture according to embodiment 38 comprising from 0 to 2000 ppm by weight of one or more ethers of respective (meth)acrylic acid ester alcohols, in each case relative to the total weight of (meth)acrylic acid esters according to embodiment 38 present in the mixture.

[0129] 43. The mixture according to any of embodiments 35 to 42, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere.

[0130] 44. The mixture according to embodiment 43, wherein the oxygen-containing atmosphere has an oxygen content of 5 to 30 vol.% oxygen, preferably 5 to 21 vol.% oxygen.

[0131] 45. The mixture according to embodiment 43 or 44, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere for at least 10 seconds, preferably at least 1 minute, more preferably at least 10 minutes, particularly preferably at least 60 minutes.

[0132] 46. ​​The mixture according to any of embodiments 35 to 45, wherein the mixture comprises a costabilizer.

[0133] 47. The mixture according to embodiment 46, wherein the total amount of costabilizers present in the mixture is 0.1 to 5000 ppm by weight, preferably 1 to 4000 ppm by weight, in particular 5 to 2500 ppm by weight, and more preferably 50 to 750 ppm by weight, relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0134] 48. The mixture according to embodiment 46 or 47, wherein the co-stabilizer is a metal salt from the group consisting of copper, manganese and cerium salts, phenothiazines, phenolic compounds, N-oxyls, phenylenediamines, nitroso compounds, urea, thiourea or a mixture of two or more of the aforementioned classes of substances.

[0135] 49. Use of one or more compounds of general formula (I) as defined in any of embodiments 35 to 37 for storage and / or transport stabilization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates.

[0136] 50. Use according to embodiment 49, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0137] 51. Use according to embodiment 49 or 50, in which the compound of general formula (I) is used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, in particular 10 to 500 ppm by weight, relative to the total weight of the amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate to be stabilized.

[0138] 52. (Meth)acrylic acid is stabilized and the stabilized (meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. Use according to embodiment 49 or 51, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, in each case relative to the amount of (meth)acrylic acid.

[0139] 53. One or more (meth)acrylic acid esters according to embodiment 50 are stabilized, and the stabilized (meth)acrylic acid esters are selected from the group consisting of the following components: a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 50; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 50; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 50; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 50. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 50; f. Use according to embodiment 50 or 51, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 50.

[0140] 54. A process for polymerizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates in the presence of one or more compounds of general formula (I) as defined in any of embodiments 35 to 37, wherein the reaction mixture is saturated with oxygen by 0 to 50%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0 to 1%, and most preferably 0 to 0.1%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0141] 55. The process according to embodiment 54, wherein the total amount of compounds of general formula (I) in the reaction mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the reaction mixture.

[0142] 56. The process according to embodiment 54 or 55, wherein the polymerization is carried out at a temperature of from 50 to 150°C, preferably from 70 to 120°C.

[0143] 57. The process according to any of embodiments 54 to 56, wherein the polymerization is carried out under a nitrogen atmosphere having a nitrogen content of 85 to 100 vol% and an oxygen content of less than 5 vol%, preferably a nitrogen content of 90 to 100 vol%, more preferably a nitrogen content of 99 to 100%.

[0144] 58. The method according to any of embodiments 54 to 58, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0145] 59. (Meth)acrylic acid to be polymerized is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to any of embodiments 54 or 57, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate relative to the amount of (meth)acrylic acid.

[0146] 60. The (meth)acrylic acid ester to be polymerized is a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 58; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 58; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 58; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 58. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 58; f. The method according to embodiment 58, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 58.

[0147] 61. A method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates through the use of one or more compounds of general formula (I) as defined in any of embodiments 35 to 37.

[0148] 62. The method according to embodiment 61, wherein the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate is stabilized during storage and / or transportation.

[0149] 63. The method according to embodiment 61 or 62, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0150] 64. (Meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to embodiment 61 or 62, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate relative to the amount of (meth)acrylic acid.

[0151] 65. (Meth)acrylic acid esters are a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 63; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 63; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 63; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 63. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 63; f. The process according to embodiment 63, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 63.

[0152] 66. The method according to any of embodiments 61 to 65, wherein the method comprises providing a mixture comprising one or more compounds of general formula (I) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, wherein the mixture is saturated with oxygen by 50 to 100%, preferably by 90 to 100%, more preferably by 95 to 100%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0153] 67. The process according to embodiment 66, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the total weight of the mixture.

[0154] 68. The process according to any of embodiments 61 to 67, wherein the compounds of general formula (I) are used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, and in particular 10 to 500 ppm by weight, in each case relative to the total weight of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0155] 69.General formula (III)

[0156] [ka]

[0157] (In the formula, R 9 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 It includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 10 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 11 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, and 2-pyridyl. , 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group is optionally esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl), and a mixture comprising one or more compounds of (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0158] 70. The mixture according to embodiment 69, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0159] 71. The mixture according to embodiment 69 or 70, wherein the total amount of compounds of general formula (III) in the mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0160] 72. The mixture according to any of embodiments 69 to 71, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, in each case relative to the total weight of the mixture.

[0161] 73. A mixture comprising (meth)acrylic acid, and a. 20 to 15,000 ppm by weight of water, relative to the total weight of (meth)acrylic acid present in the mixture; b. 100 to 20,000 ppm by weight of di(meth)acrylic acid, based on the total weight of (meth)acrylic acid present in the mixture c. 100 to 2000 ppm by weight of acetic acid, based on the total weight of (meth)acrylic acid present in the mixture d. 100 to 2000 ppm by weight of propionic acid, based on the total weight of (meth)acrylic acid present in the mixture e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde, relative to the total weight of (meth)acrylic acid present in the mixture; f. 0 to 2 ppm by mass of protoanemonin, based on the total mass of (meth)acrylic acid present in the mixture g. 0 to 1 ppm by weight of maleic acid, based on the total weight of (meth)acrylic acid present in the mixture h. 0 to 1 ppm by weight of maleic anhydride, based on the total weight of (meth)acrylic acid present in the mixture i. A mixture according to any of embodiments 69, 71, or 72, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the total weight of (meth)acrylic acid present in the mixture.

[0162] 74. The mixture comprises one or more (meth)acrylic esters according to embodiment 70, wherein the mixture comprises the following components: a. 1 to 2000 ppm by weight, preferably 1 to 500 ppm by weight, of water, in each case relative to the total weight of the (meth)acrylic esters according to embodiment 70 present in the mixture; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 70 present in the mixture; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 70 present in the mixture; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 70 present in the mixture; e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with alcohols of the respective (meth)acrylic acid esters, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 70 present in the mixture; f. A mixture according to any of embodiments 70 to 72 comprising from 0 to 2000 ppm by weight of one or more ethers of respective (meth)acrylic acid ester alcohols, in each case relative to the total weight of (meth)acrylic acid esters according to embodiment 70 present in the mixture.

[0163] 75. The mixture according to any of embodiments 69 to 74, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere.

[0164] 76. The mixture according to embodiment 75, wherein the oxygen-containing atmosphere has an oxygen content of 5 to 30 vol.% oxygen, preferably 5 to 21 vol.% oxygen.

[0165] 77. The mixture according to embodiment 75 or 76, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere for at least 10 seconds, preferably at least 1 minute, more preferably at least 10 minutes, particularly preferably at least 60 minutes.

[0166] 78. The mixture according to any of embodiments 69 to 77, wherein the mixture comprises a costabilizer.

[0167] 79. The mixture according to embodiment 78, wherein the total amount of co-stabilizers present in the mixture is 0.1 to 5000 ppm by weight, preferably 1 to 4000 ppm by weight, in particular 5 to 2500 ppm by weight, and more preferably 50 to 750 ppm by weight, relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0168] 80. The mixture according to embodiment 78 or 79, wherein the co-stabilizer is a metal salt from the group consisting of copper, manganese and cerium salts, phenothiazines, phenolic compounds, N-oxyls, phenylenediamines, nitroso compounds, urea, thiourea or a mixture of two or more of the aforementioned classes of substances.

[0169] 81. Use of one or more compounds of general formula (III) as defined in embodiment 69 for storage and / or transport stabilization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates.

[0170] 82. Use according to embodiment 81, in which the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0171] 83. Use according to embodiment 81 or 82, in which the compound of general formula (III) is used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, in particular 10 to 500 ppm by weight, relative to the total weight of the amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate to be stabilized.

[0172] 84. (Meth)acrylic acid is stabilized and the stabilized (meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. Use according to embodiment 81 or 83, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, in each case relative to the amount of (meth)acrylic acid.

[0173] 85. One or more (meth)acrylic acid esters according to embodiment 82 are stabilized, and the stabilized (meth)acrylic acid esters are selected from the group consisting of the following components: a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 82; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 82; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 82; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 82. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 82; f. Use according to embodiment 82 or 83, comprising from 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols, relative to the amount of (meth)acrylic acid ester according to embodiment 82.

[0174] 86. A process for polymerizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates in the presence of one or more compounds of general formula (III) as defined in embodiment 69, wherein the reaction mixture is saturated with oxygen by 0 to 50%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0 to 1%, and most preferably 0 to 0.1%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30% by volume, preferably having an oxygen content of 5 to 21% by volume.

[0175] 87. The process according to embodiment 86, wherein the total amount of compounds of general formula (III) in the reaction mixture is in each case from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the reaction mixture.

[0176] 88. The process according to embodiment 86 or 87, wherein the polymerization is carried out at a temperature of 50 to 150°C, preferably 70 to 120°C.

[0177] 89. The process according to any of embodiments 86 to 88, wherein the polymerization is carried out under a nitrogen atmosphere having a nitrogen content of 85 to 100 vol% and an oxygen content of less than 5 vol%, preferably a nitrogen content of 90 to 100 vol%, more preferably a nitrogen content of 99 to 100%.

[0178] 90. The method according to any of embodiments 86 to 89, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0179] 91. (Meth)acrylic acid to be polymerized is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to any of embodiments 86 or 89, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the amount of (meth)acrylic acid.

[0180] 92. The (meth)acrylic acid ester to be polymerized is a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 90; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 90; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 90; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 90. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 90; f. The process according to embodiment 90, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 90.

[0181] 93. A method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates through the use of one or more compounds of general formula (III) as defined in embodiment 69.

[0182] 94. The method according to embodiment 93, wherein the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate is stabilized during storage and / or transportation.

[0183] 95. The method according to embodiment 93 or 94, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0184] 96. (Meth)acrylic acid is the following component a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to embodiment 93 or 94, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the amount of (meth)acrylic acid.

[0185] 97. (Meth)acrylic acid esters are a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 95; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 95; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 95; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 95. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 95; f. The method according to embodiment 95, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 95.

[0186] 98. The method according to any of embodiments 93 to 97, wherein the method comprises providing a mixture comprising one or more compounds of general formula (III) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, wherein the mixture is 50 to 100%, preferably 90 to 100%, more preferably 95 to 100% saturated with oxygen, where oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0187] 99. The process according to embodiment 98, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the total weight of the mixture.

[0188] 100. The process according to any of embodiments 93 to 99, wherein the compounds of general formula (III) are used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, and in particular 10 to 500 ppm by weight, in each case relative to the total weight of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0189] 101.General formula (IV)

[0190] [ka]

[0191] (In the formula, R 12 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20 It includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and 2-ethoxyphenyl. , 3-ethoxyphenyl, 4-ethoxyphenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 13 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 14 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. phenyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl includes a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, or 4-isopropoxyphenyl; R 15 H, C1 to C 20 Alkyl, C1 to C 20 Alkyl is a straight or branched C1 to C 20 Alkyl group or cyclic C3 to C 20The alkyl group includes alkyl groups, and preferred alkyl groups are C1 to C8 alkyl, and more preferred alkyl groups are C1 to C6 alkyl, phenyl, cyanophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, dimethylphenyl, such as 3,4-dimethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl. nyl, 4-isopropylphenyl, benzyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, (carboxymethyl)phenyl, wherein the carboxyl group may be esterified with a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, (N,N-dimethylsulfonamido)phenyl, sulfonamidophenyl, a carboxylic acid ester having a C1 to C8 alkyl, such as -COOMe, an alkanoyl having a C1 to C6 alkyl, wherein the C1 to C6 alkyl is a linear or branched C1 to C6 alkyl group or a cyclic C3 to C6 alkyl group, 4-isopropoxyphenyl, NH, NH(CO)R 16 Contains R 16 is H, C1 to C6 alkyl, phenyl, tolyl, for example m- or p-tolyl, 4-methoxyphenyl or dimethylphenyl, for example 3,4-dimethylphenyl), and a mixture comprising (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate.

[0192] 102. The mixture according to embodiment 101, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0193] 103. The mixture according to embodiment 101 or 102, wherein the total amount of compounds of general formula (IV) in the mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0194] 104. The mixture according to any of embodiments 101 to 103, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, in each case relative to the total weight of the mixture.

[0195] 105. A mixture containing (meth)acrylic acid, and the mixture containing the following components: a. 20 to 15,000 ppm by weight of water, relative to the total weight of (meth)acrylic acid present in the mixture; b. 100 to 20,000 ppm by weight of di(meth)acrylic acid, based on the total weight of (meth)acrylic acid present in the mixture c. 100 to 2000 ppm by weight of acetic acid, based on the total weight of (meth)acrylic acid present in the mixture d. 100 to 2000 ppm by weight of propionic acid, based on the total weight of (meth)acrylic acid present in the mixture e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde, relative to the total weight of (meth)acrylic acid present in the mixture; f. 0 to 2 ppm by mass of protoanemonin, based on the total mass of (meth)acrylic acid present in the mixture g. 0 to 1 ppm by weight of maleic acid, based on the total weight of (meth)acrylic acid present in the mixture h. 0 to 1 ppm by weight of maleic anhydride, based on the total weight of (meth)acrylic acid present in the mixture i. A mixture according to any of embodiments 101, 103, or 104, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the total weight of (meth)acrylic acid present in the mixture.

[0196] 106. The mixture comprises one or more (meth)acrylic acid esters according to embodiment 102, wherein the mixture comprises the following components: a. 1 to 2000 ppm by weight, preferably 1 to 500 ppm by weight, of water, in each case relative to the total weight of the (meth)acrylic esters according to embodiment 102 present in the mixture; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 102 present in the mixture; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohols of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 102 present in the mixture; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with alcohols of the respective (meth)acrylic acid esters, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 102 present in the mixture; e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with alcohols of the respective (meth)acrylic acid esters, in each case relative to the total weight of the (meth)acrylic acid esters according to embodiment 102 present in the mixture; f. A mixture according to any of embodiments 102 to 104 comprising from 0 to 2000 ppm by weight of one or more ethers of respective (meth)acrylic acid ester alcohols, in each case relative to the total weight of (meth)acrylic acid esters according to embodiment 102 present in the mixture.

[0197] 107. The mixture according to any of embodiments 101 to 106, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere.

[0198] 108. The mixture according to embodiment 107, wherein the oxygen-containing atmosphere has an oxygen content of 5 to 30 vol.% oxygen, preferably 5 to 21 vol.% oxygen.

[0199] 109. The mixture according to embodiment 107 or 108, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere for at least 10 seconds, preferably at least 1 minute, more preferably at least 10 minutes, particularly preferably at least 60 minutes.

[0200] 110. The mixture according to any of embodiments 101 to 109, wherein the mixture comprises a costabilizer.

[0201] 111. The mixture according to embodiment 110, wherein the total amount of costabilizers present in the mixture is 0.1 to 5000 ppm by weight, preferably 1 to 4000 ppm by weight, in particular 5 to 2500 ppm by weight, and more preferably 50 to 750 ppm by weight, relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture.

[0202] 112. The mixture according to embodiment 110 or 111, wherein the co-stabilizer is a metal salt from the group consisting of copper, manganese and cerium salts, phenothiazines, phenolic compounds, N-oxyls, phenylenediamines, nitroso compounds, urea, thiourea or a mixture of two or more of the aforementioned classes of substances.

[0203] 113. Use of one or more compounds of general formula (IV) as defined in embodiment 101 for storage and / or transport stabilization of (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates.

[0204] 114. Use according to embodiment 113, in which the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or a mixture of two or more of said (meth)acrylic acid esters.

[0205] 115. Use according to embodiment 113 or 114, in which the compound of general formula (IV) is used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, in particular 10 to 500 ppm by weight, relative to the total weight of the amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate to be stabilized.

[0206] 116. (Meth)acrylic acid is stabilized and the stabilized (meth)acrylic acid is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. Use according to embodiment 113 or 115, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, in each case relative to the amount of (meth)acrylic acid.

[0207] 117. One or more (meth)acrylic acid esters according to embodiment 114 are stabilized, and the stabilized (meth)acrylic acid esters are selected from the group consisting of the following components: a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 114; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 114; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 114; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 114. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 114; f. Use according to embodiment 114 or 115, comprising from 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols, relative to the amount of the (meth)acrylic acid ester according to embodiment 114.

[0208] 118. A process for polymerizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates in the presence of one or more compounds of general formula (IV) as defined in embodiment 101, wherein the reaction mixture is saturated with oxygen by 0 to 50%, preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0 to 1%, and most preferably 0 to 0.1%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0209] 119. The process according to embodiment 118, wherein the total amount of compounds of general formula (IV) in the reaction mixture is from 0.1 to 1000 ppm by weight, preferably from 1 to 900 ppm by weight, more preferably from 10 to 800 ppm by weight, and in particular from 10 to 500 ppm by weight, in each case relative to the total weight of the amounts of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the reaction mixture.

[0210] 120. The process according to embodiment 118 or 119, wherein the polymerization is carried out at a temperature of 50 to 150°C, preferably 70 to 120°C.

[0211] 121. The process according to any of embodiments 118 to 120, wherein the polymerization is carried out under a nitrogen atmosphere having a nitrogen content of 85 to 100 vol% and an oxygen content of less than 5 vol%, preferably a nitrogen content of 90 to 100 vol%, more preferably a nitrogen content of 99 to 100 vol%.

[0212] 122. The method according to any of embodiments 118 to 121, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0213] 123. The (meth)acrylic acid to be polymerized is a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to any of embodiments 118 to 121, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the amount of (meth)acrylic acid.

[0214] 124. The (meth)acrylic acid ester to be polymerized is a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 122; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 122; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 122; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 122. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 122; f. The method according to embodiment 122, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 122.

[0215] 125. A method for stabilizing (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylates through the use of one or more compounds of general formula (IV) as defined in embodiment 101.

[0216] 126. The method according to embodiment 125, wherein the (meth)acrylic acid and / or C1 to C8 alkyl (meth)acrylate is stabilized during storage and / or transportation.

[0217] 127. The method according to embodiment 125 or 126, wherein the C1 to C8 alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

[0218] 128. (Meth)acrylic acid is the following component a. 20 to 15,000 ppm by mass of water relative to the amount of (meth)acrylic acid; b. 100 to 20,000 ppm by mass of di(meth)acrylic acid, based on the amount of (meth)acrylic acid; c. 100 to 2000 ppm by mass of acetic acid relative to the amount of (meth)acrylic acid; d. 100 to 2000 ppm by mass of propionic acid relative to the amount of (meth)acrylic acid; e. one or more aldehydes, such as acetaldehyde, acrolein, propionaldehyde, 2-furfural, 3-furfural, coumarone or benzaldehyde, in an amount of 0 to 1 ppm by weight of each aldehyde relative to the amount of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin relative to the amount of (meth)acrylic acid g. Maleic acid 0 to 1 ppm by mass relative to the amount of (meth)acrylic acid h. 0 to 1 ppm by mass of maleic anhydride relative to the amount of (meth)acrylic acid i. The process according to embodiment 125 or 126, comprising one or more of 0 to 30 ppm by weight, preferably 0 to 1 ppm by weight, of allyl acrylate, relative to the amount of (meth)acrylic acid.

[0219] 129. (Meth)acrylic acid esters are a. from 1 to 2000 ppm by weight, preferably from 1 to 500 ppm by weight, of water, in each case relative to the amount of (meth)acrylic ester according to embodiment 127; b. 1 to 2000 ppm by weight, preferably 1 to 100 ppm by weight, of (meth)acrylic acid, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 127; c. 0.01 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight, of alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 127; d. 0.1 to 2000 ppm by weight, preferably 10 to 1000 ppm by weight, of propionic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of the (meth)acrylic acid ester according to embodiment 127. e. 1 to 2000 ppm by weight, preferably 5 to 2000 ppm by weight, of acetic acid esters with the alcohol of the respective (meth)acrylic acid ester, in each case relative to the amount of (meth)acrylic acid ester according to embodiment 127; f. The process according to embodiment 127, comprising 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols relative to the amount of the (meth)acrylic acid ester according to embodiment 127.

[0220] 130. The method according to any of embodiments 125 to 129, wherein the method comprises providing a mixture comprising one or more compounds of general formula (IV) and (meth)acrylic acid and / or a C1 to C8 alkyl (meth)acrylate, wherein the mixture is saturated with oxygen by 50 to 100%, preferably 90 to 100%, more preferably 95 to 100%, where the oxygen saturation refers to the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%, preferably having an oxygen content of 5 to 21 vol%.

[0221] 131. The process according to embodiment 130, wherein the total amount of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate in the mixture is at least 5% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, more preferably at least 90% by weight, and particularly preferably at least 95% by weight, based on the total weight of the mixture.

[0222] 132. The process according to any of embodiments 125 to 131, wherein the compounds of general formula (IV) are used in a total amount of 0.1 to 1000 ppm by weight, preferably 1 to 900 ppm by weight, more preferably 10 to 800 ppm by weight, and in particular 10 to 500 ppm by weight, in each case relative to the total weight of (meth)acrylic acid and C1 to C8 alkyl (meth)acrylate present in the mixture. [Example]

[0223] The examples that follow do not limit the subject matter of the present invention.

[0224] [Table 1]

[0225] The acrylic acid used in the experiments was freshly distilled to remove the stabilizers contained therein. The distilled acrylic acid had a purity of more than 99.5% by mass. The secondary components present in the distilled acrylic acid were acetic acid (0.0726% by mass), diacrylic acid (0.0497% by mass) and propionic acid (0.0184% by mass).

[0226] The masses reported in the experimental descriptions, e.g. mass percent (wt%) or mass ppm values ​​relative to acrylic acid, are in each case based on the mass of acrylic acid used and include any secondary components contained therein.

[0227] Experiment to test polymerization inhibition under air or nitrogen: In a comparative experiment, an acrylic acid solution containing 40 ppm by weight of 4-methoxyphenol (MEHQ) was prepared, with the given ppm by weight value being based on the weight of acrylic acid used.

[0228] In further comparative experiments, mixtures of acrylic acid and compounds other than compounds of general formula (I), (II), (III) or (IV) were prepared, the molar amounts of the compounds used corresponding to the molar amount of MEHQ in the comparative experiments.

[0229] In the experiments of the present invention, mixtures of acrylic acid and compounds of general formula (I), (II), (III) and / or (IV) were prepared, and the molar amounts of compounds of general formula (I), (II), (III) and / or (IV) in the mixtures corresponded to the molar amount of MEHQ in the comparative experiments.

[0230] Exemplary dilution series: 2.5 g of an acrylic acid solution having an MEHQ content of 1000 ppm by weight relative to the weight of acrylic acid used was diluted with acrylic acid to an MEHQ content of 500 ppm by weight relative to the weight of acrylic acid used.

[0231] 2.5 g of the acrylic acid solution thus obtained were diluted with acrylic acid to an MEHQ content of 250 ppm by weight relative to the weight of acrylic acid used.

[0232] 2.5 g of the acrylic acid solution thus obtained were diluted with acrylic acid to an MEHQ content of 125 ppm by weight relative to the weight of acrylic acid used.

[0233] 2.5 g of the acrylic acid solution thus obtained were diluted with acrylic acid to an MEHQ content of 80 ppm by weight relative to the weight of acrylic acid used.

[0234] 2.5 g of the acrylic acid solution thus obtained were diluted with acrylic acid to an MEHQ content of 40 ppm by weight relative to the weight of acrylic acid used.

[0235] The initiator solution used was a freshly prepared toluene solution of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), with a 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) content of 6420 ppm by mass relative to the mass of toluene in the initiator solution.

[0236] Test for polymerization inhibition under air: 2.2 g of an acrylic acid solution containing 0.000715 mmol of each polymerization stabilizer was initially charged under air. 0.22 g of the initiator solution was added to the initially charged acrylic acid solution, and the mixture was homogenized. 1.9 ml of the mixture thus obtained was transferred to a 4.5 ml reaction vessel under air. The reaction vessel was sealed and equipped with a temperature sensor. The temperature sensor was extended into the mixture inside the reaction vessel.

[0237] The reaction vessel containing the mixture was then placed in a heating block heated to 40°C.

[0238] The temperature profile was measured over time once the mixture reached a temperature of 40° C. The time period from reaching 40° C. to reaching the maximum temperature was used as a reference value for the inhibitory capacity of each polymerization inhibitor.

[0239] For the mixture with MEHQ as a polymerization stabilizer, a temperature increase from 145°C to a maximum temperature of 185°C was measured, which lasted 42 seconds. The maximum temperature was reached 9188 seconds after the mixture had thermally equilibrated at 40°C. For the calculation of the efficiency of the polymerization stabilizer for MEHQ, the value at 9188 seconds was used as a 100 % This corresponds to an efficiency of

[0240] For the mixture with 5-methyl-2-phenyl-4H-pyrazol-3-one as the polymerization stabilizer, a temperature increase from 125°C to a maximum temperature of 165°C was observed, which lasted 48 seconds, and the maximum temperature was reached 7874 seconds after the mixture had thermally equilibrated at 40°C.

[0241] The efficiency of 5-methyl-2-phenyl-4H-pyrazol-3-one as a polymerization stabilizer relative to MEHQ was therefore 86 percent.

[0242] Testing for polymerization inhibition under nitrogen: 2.2 g of acrylic acid solution containing 0.000715 mmol of each polymerization stabilizer was initially charged under air. 0.22 g of initiator solution was added to the initially charged acrylic acid solution, and the mixture was homogenized. 1.9 ml of the mixture thus obtained was transferred to a 4.5 ml reaction vessel under air. The reaction vessel was sealed and equipped with a temperature sensor. The temperature sensor penetrated into the mixture in the reaction vessel. Nitrogen was introduced into the pressure-equalized reaction vessel above the initially charged mixture. The nitrogen flow rate was 3 to 4 l / h. The flow-in time was 20 seconds. The nitrogen had a purity of more than 99.9%.

[0243] The reaction vessel containing the mixture was placed in a heating block. The mixture was then heated to 40° C. in the heating block for 4 minutes.

[0244] The temperature profile was measured over time once the mixture reached a temperature of 40° C. The time period from reaching 40° C. to reaching the maximum temperature was used as a reference value for the inhibitory capacity of each polymerization inhibitor.

[0245] For the mixture with MEHQ as polymerization stabilizer, a temperature increase from 133°C to a maximum temperature of 173°C was measured, which lasted 54 seconds. The maximum temperature was reached 3978 seconds after the mixture had thermally equilibrated at 40°C. For calculation of the efficiency of the polymerization stabilizer relative to MEHQ, the value of 3978 seconds corresponds to 100% efficiency.

[0246] For the mixture with 5-methyl-2-phenyl-4H-pyrazol-3-one as the polymerization stabilizer, a temperature increase from 119°C to a maximum temperature of 159°C was observed, which lasted 66 seconds, and the maximum temperature was reached 1056 seconds after the mixture had thermally equilibrated at 40°C.

[0247] The efficiency of 5-methyl-2-phenyl-4H-pyrazol-3-one as a polymerization stabilizer was therefore 27 percent relative to MEHQ.

[0248] Results of tests with acrylic acid and compounds not according to the invention:

[0249] [Table 2A]

[0250] [Table 2B]

[0251] Results of tests with acrylic acid and the compound of the present invention:

[0252] [Table 3A]

[0253] [Table 3B]

[0254] [Table 3C]

[0255] [Table 3D]

[0256] [Table 3E]

[0257] [Table 3F]

[0258] Polymerization Experiment: A reaction vessel was charged with 450 g of deionized water under a nitrogen atmosphere. The initial reaction mixture was heated with stirring to 95° C. Once the temperature reached 95° C., three streams were fed while maintaining the temperature. Stream 1: 500g of acrylic acid delivered over 5 hours Stream 2: 15 g sodium hypophosphite in 35 g deionized water fed over 4.75 h Stream 3: 5 g sodium persulfate in 66.4 g deionized water fed over 5.25 h

[0259] After the addition of the three streams, the reaction mixture was stirred for an additional hour at 95° C. The reaction mixture was then cooled to room temperature and 80 g of deionized water was added.

[0260] In the inventive experiment, acrylic acid from stream 1 was stabilized with 280 ppm by weight of edaravone (5-methyl-2-phenyl-4H-pyrazol-3-one) relative to the weight of acrylic acid. In the comparative experiment, acrylic acid from stream 1 was stabilized with 200 ppm by weight of MEHQ relative to the weight of acrylic acid.

[0261] The obtained polymer was analyzed by GPC (calibration with Na-PAA standards, eluent 0.01 mol / l phosphate buffer, pH 7.4, distilled water containing 0.01 M NaN3).

[0262] [Table 4]

[0263] Testing with acrylates: Experiment to test polymerization inhibition under air or nitrogen: Experiments to test for polymerization inhibition under air or nitrogen were carried out using ethyl acrylate as the stabilizer to be removed. The ethyl acrylate used contained 10 to 20 ppm MEHQ by weight relative to the amount of ethyl acrylate and was filtered without pressure through Type 90 activated neutral alumina. For each 100 ml of stabilized ethyl acrylate, 20 g of Type 90 activated neutral alumina was used. After filtration, MEHQ was no longer detectable by HPLC analysis in the ethyl acrylate.

[0264] In a comparative experiment, an ethyl acrylate solution containing 13 ppm by weight of MEHQ was prepared, the ppm by weight being relative to the weight of ethyl acrylate present in the solution.

[0265] In further comparative experiments, mixtures of ethyl acrylate and compounds different from the compounds of general formula (I), (II), (III) or (IV) were prepared, the molar amounts of the compounds used corresponding to the molar amount of MEHQ in the comparative experiments.

[0266] In the experiments of the present invention, a mixture of ethyl acrylate and a compound of general formula (I), (II), (III) or (IV) was prepared, and the molar amount of the compound of general formula (I), (II), (III) or (IV) in the mixture corresponded to the molar amount of MEHQ in the comparative experiments.

[0267] Exemplary dilution series: 1.0 g of an ethyl acrylate solution having an MEHQ content of 500 ppm by weight relative to the weight of ethyl acrylate present in the solution was diluted with ethyl acrylate to an MEHQ content of 240 ppm by weight relative to the weight of ethyl acrylate in the solution.

[0268] 1.5 g of the ethyl acrylate solution thus obtained was diluted with ethyl acrylate to an MEHQ content of 80 ppm by weight relative to the weight of ethyl acrylate in the solution.

[0269] 1.5 g of the ethyl acrylate solution thus obtained was diluted with ethyl acrylate to an MEHQ content of 30 ppm by weight relative to the weight of ethyl acrylate in the solution.

[0270] 2.0 g of the ethyl acrylate solution thus obtained was diluted with ethyl acrylate to an MEHQ content of 13 ppm by weight relative to the weight of ethyl acrylate in the solution.

[0271] The initiator solution used was a freshly prepared toluene solution of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), with a 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) content of 6420 ppm by mass relative to the mass of toluene in the initiator solution.

[0272] Test for polymerization inhibition under air: 2.0 g of ethyl acrylate solution containing 0.00021 mmol of each polymerization stabilizer was initially charged under air. 0.17 g of initiator solution was added to the initially charged ethyl acrylate solution, and the mixture was homogenized. 1.9 ml of the mixture thus obtained was transferred to a 4.5 ml reaction vessel under air. The reaction vessel was sealed and equipped with a temperature sensor. The temperature sensor was extended into the mixture in the reaction vessel.

[0273] The reaction vessel containing the mixture was placed in a heating block heated to 40°C.

[0274] The temperature profile was measured over time once the mixture reached a temperature of 40° C. The time period from reaching 40° C. to reaching the maximum temperature was used as a reference value for the inhibitory capacity of each polymerization inhibitor.

[0275] For the mixture with MEHQ as polymerization stabilizer, a temperature increase of 8°C to a maximum temperature of 48°C was measured, which lasted for 1200 seconds. The maximum temperature was reached 29084 seconds after the mixture had thermally equilibrated at 40°C. In calculating the efficiency of the polymerization stabilizer relative to MEHQ, the value of 29084 seconds corresponds to 100% efficiency.

[0276] For the inventive mixture with 5-methyl-2-phenyl-4H-pyrazol-3-one as polymerization stabilizer, a temperature increase of 6°C to a maximum temperature of 46°C was observed, which lasted 1200 seconds. The maximum temperature was reached 28470 seconds after the mixture had thermally equilibrated at 40°C. The efficiency of 5-methyl-2-phenyl-4H-pyrazol-3-one as polymerization stabilizer was therefore 98 percent relative to MEHQ.

[0277] Testing for polymerization inhibition under nitrogen: 2.0 g of ethyl acrylate solution containing 0.00021 mmol of each polymerization stabilizer was initially charged under air. 0.17 g of initiator solution was added to the initially charged ethyl acrylate solution, and the mixture was homogenized. 1.9 ml of the mixture thus obtained was transferred to a 4.5 ml reaction vessel under air. The reaction vessel was sealed and equipped with a temperature sensor. The temperature sensor penetrated into the mixture in the reaction vessel. Nitrogen was introduced into the pressure-equalized reaction vessel above the initially charged mixture. The nitrogen flow rate was 3 to 4 l / h. The flow-in time was 20 seconds. The nitrogen had a purity of more than 99.9%.

[0278] The reaction vessel containing the mixture was placed in a heating block. The mixture was then heated to 40° C. in the heating block for 4 minutes.

[0279] The temperature profile was measured over time once the mixture reached a temperature of 40° C. The time period from reaching 40° C. to reaching the maximum temperature was used as a reference value for the inhibitory capacity of each polymerization inhibitor.

[0280] For the mixture with MEHQ as a polymerization stabilizer, a temperature increase of 73°C to a maximum temperature of 113°C was measured, which lasted for 240 seconds. The maximum temperature was reached 460 seconds after the mixture had been thermally equilibrated at 40°C. For the calculation of the efficiency of the polymerization stabilizer for MEHQ, the value at 460 seconds was calculated as 100 % This corresponds to an efficiency of

[0281] For the inventive mixture with 5-methyl-2-phenyl-4H-pyrazol-3-one as the polymerization stabilizer, a temperature increase from 80° C. to a maximum temperature of 120° C. was observed, which lasted 240 seconds. The maximum temperature was reached 426 seconds after the mixture had thermally equilibrated at 40° C. The efficiency of 5-methyl-2-phenyl-4H-pyrazol-3-one as a polymerization stabilizer was therefore 93 percent relative to MEHQ.

[0282] Results of tests with ethyl acrylate and the compound of the present invention:

[0283] [Table 5A]

[0284] [Table 5B]

[0285] Polymerization experiments with acrylates: Homopolymerization of n-butyl acrylate: Comparative experiment: A reaction vessel was charged with 210 g of n-butyl acetate, 14.7 g of n-butyl acrylate (stabilized with 15 ppm by weight of MEHQ relative to the amount of n-butyl acrylate), and 0.08 g of azobisisobutyronitrile (AIBN) under a nitrogen atmosphere. The initial reaction mixture was heated to 80° C. with stirring. 15 minutes after reaching a temperature of 80° C., two streams were fed while maintaining the temperature. Stream 1: 195.3 g of n-butyl acrylate (stabilized with 15 ppm by weight of MEHQ relative to the amount of n-butyl acrylate) and 100.5 g of n-butyl acetate fed over 2 h Stream 2: 0.98 g AIBN and 74.1 g n-butyl acetate fed over 3 h After addition of the stream, the reaction mixture was stirred at 80°C for 2 h and then cooled to 25°C.

[0286] Of the present invention: A reaction vessel was charged with 210 g of n-butyl acetate, 14.7 g of n-butyl acrylate (stabilized with 21 ppm by weight of 5-methyl-2-phenyl-4H-pyrazol-3-one relative to the amount of n-butyl acrylate), and 0.08 g of AIBN under a nitrogen atmosphere. The initial reaction mixture was heated to 80° C. with stirring. 15 minutes after reaching a temperature of 80° C., two streams were fed while maintaining the temperature. Stream 1: 195.3 g of n-butyl acrylate (stabilized with 21 ppm by weight of 5-methyl-2-phenyl-4H-pyrazol-3-one relative to the amount of n-butyl acrylate) and 100.5 g of n-butyl acetate, fed over 2 h Stream 2: 0.98 g AIBN and 74.1 g n-butyl acetate fed over 3 h After addition of the stream, the reaction mixture was stirred at 80° C. for 2 h and then cooled to room temperature.

[0287] The resulting polymer was analyzed by GPC (calibration with polystyrene standards, eluent: THF + 0.1% by volume of trifluoroacetic acid).

[0288] [Table 6]

[0289] Emulsion polymerization of n-butyl acrylate, styrene and methacrylic acid: Comparative experiment: A reaction vessel was charged with 250 g of demineralized water and 4 g of potassium peroxodisulfate under a nitrogen atmosphere. The initial reaction mixture was heated to 60° C. with stirring. At 60° C., 8 g of Feed Stream 1 was fed into the reaction mixture with stirring. Five minutes after addition, the remainder of Feed Stream 1 and Feed Stream 2 were fed into the reaction mixture with stirring at 60° C. The remainder of Feed Stream 1 was fed into the reaction mixture over 160 minutes, and Feed Stream 2 was fed over 150 minutes. Feedstream 1: 4 g sodium bisulfite, 100 g demineralized water Feedstream 2: 400 g styrene (stabilized with 20 ppm MEHQ by weight relative to the amount of styrene), 400 g n-butyl acrylate (stabilized with 15 ppm MEHQ by weight relative to the amount of n-butyl acrylate), 15 g methacrylic acid (stabilized with 200 ppm MEHQ by weight relative to the amount of methacrylic acid), 20 g Disponil FES 147 and 450 g demineralized water.

[0290] At the end of the addition of Feed Stream 1, the temperature of the reaction mixture was increased to 65° C. and the reaction mixture was held at this temperature for 1 h. The resulting dispersion was cooled to room temperature, adjusted to pH 7 with aqueous ammonia (25% by weight), and filtered through a sieve.

[0291] Of the present invention: A reaction vessel was charged with 250 g of demineralized water and 4 g of potassium peroxodisulfate under a nitrogen atmosphere. The initial reaction mixture was heated to 60° C. with stirring. At 60° C., 8 g of Feed Stream 1 was fed into the reaction mixture with stirring. Five minutes after addition, the remainder of Feed Stream 1 and Feed Stream 2 were fed into the reaction mixture with stirring at 60° C. The remainder of Feed Stream 1 was fed into the reaction mixture over 160 minutes, and Feed Stream 2 was fed over 150 minutes. Feedstream 1: 4 g sodium bisulfite, 100 g demineralized water Feedstream 2: 400 g of styrene (stabilized with 28 ppm edaravone by weight based on the amount of styrene), 400 g of n-butyl acrylate (stabilized with 21 ppm edaravone by weight based on the amount of n-butyl acrylate), 15 g of methacrylic acid (stabilized with 280 ppm edaravone by weight based on the amount of methacrylic acid), 20 g of Disponil FES 147, and 450 g of demineralized water.

[0292] At the end of the addition of Feed Stream 1, the temperature of the reaction mixture was increased to 65° C. and the reaction mixture was held at this temperature for 1 h. The resulting dispersion was cooled to room temperature, adjusted to pH 7 with aqueous ammonia (25% by weight), and filtered through a sieve.

[0293] [Table 7]

[0294] The average particle size (z-average) was determined as follows: Samples were analyzed on a Malvern Zetasizer Nano analyzer. Samples were diluted with Millipore water (pH 4) to a measurement concentration of 0.0005% and then determined by 5 μm filtration. Measurements were performed at 25°C.

[0295] The glass temperature was determined as follows: The polymer dispersion was dried under reduced pressure at 80° C. The glass temperature was determined by DSC. Before the measurement, the sample was cooled rapidly from 140° C. and then measured from −50° C. to 140° C. at 20 K / min.

[0296] The molar masses were determined by GPC (calibration with polystyrene standards, eluent: THF+0.1% by volume trifluoroacetic acid).

[0297] Residual monomer content was determined by headspace GC.

[0298] The amount of coagulum (aggregated polymer colloid in the apparatus and in the filter residue) was weighed.

Claims

1. General formula (II) 【Chemistry 1】 [In the formula, R 6 is H or C 1 From C 6 alkyl, 1 From C 6 The alkyl is a straight or branched C 1 From C 6 Alkyl group or cyclic C 3 From C 6 containing an alkyl group, R 7 is H, C 1 From C 6 Alkyl (C 1 From C 6 The alkyl is a straight or branched C 1 From C 6 Alkyl group or cyclic C 3 From C 6 containing alkyl groups), or C 1 From C 6 Alkanoyl having an alkyl group (C 1 From C 6 The alkyl is a straight or branched C 1 From C 6 Alkyl group or cyclic C 3 From C 6 containing an alkyl group, R 8 is H or C 1 From C 6 alkyl, 1 From C 6 The alkyl is a straight or branched C 1 From C 6 Alkyl group or cyclic C 3 From C 6 containing an alkyl group], and (meth)acrylic acid and / or C 1 From C 8 A mixture comprising alkyl (meth)acrylate, wherein the total amount of compounds of general formula (II) in the mixture is less than the total amount of (meth)acrylic acid and C present in the mixture. 1 From C 8 The amount of alkyl (meth)acrylate is 0.1 to 1000 ppm by mass relative to the total mass of the mixture.

2. C 1 From C 8 2. The mixture of claim 1, wherein the alkyl (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, or a mixture of two or more of said (meth)acrylic acid esters.

3. The total amount of the compound of general formula (II) in the mixture is determined by the ratio of the (meth)acrylic acid and C 1 From C 8 3. The mixture according to claim 1, wherein the amount of alkyl (meth)acrylate is from 10 to 500 ppm by weight relative to the total weight.

4. (Meth)acrylic acid and C in mixtures 1 From C 8 4. The mixture according to claim 1, wherein the total amount of alkyl (meth)acrylates is at least 5% by weight, relative to the total weight of the mixture.

5. The mixture comprises (meth)acrylic acid, and the mixture comprises the following components: a. 20 to 15,000 ppm by weight of water, relative to the total weight of (meth)acrylic acid present in the mixture; b. 100 to 20,000 ppm by weight of di(meth)acrylic acid, based on the total weight of (meth)acrylic acid present in the mixture c. 100 to 2000 ppm by weight of acetic acid, based on the total weight of (meth)acrylic acid present in the mixture d. 100 to 2000 ppm by weight of propionic acid, based on the total weight of (meth)acrylic acid present in the mixture e. one or more aldehydes, each of which is present in the mixture in an amount of 0 to 1 ppm by weight, relative to the total weight of (meth)acrylic acid; f. 0 to 2 ppm by mass of protoanemonin, based on the total mass of (meth)acrylic acid present in the mixture g. 0 to 1 ppm by weight of maleic acid, based on the total weight of (meth)acrylic acid present in the mixture h. 0 to 1 ppm by weight of maleic anhydride, based on the total weight of (meth)acrylic acid present in the mixture i. The mixture of any one of claims 1, 2, or 4, comprising 0 to 30 ppm by weight of one or more allyl acrylates, based on the total weight of (meth)acrylic acid present in the mixture.

6. The mixture comprises one or more (meth)acrylic acid esters as defined in claim 4, and the mixture comprises the following components: a. In each case, 1 to 2000 ppm by weight of water, relative to the total weight of the (meth)acrylic acid esters defined in claim 4 present in the mixture. b. In each case, 1 to 2000 ppm by weight of (meth)acrylic acid, relative to the total weight of the (meth)acrylic acid esters defined in claim 4 present in the mixture. c. 0.01 to 2000 ppm by weight of alcohol of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters as defined in claim 4 present in the mixture; d. 0.1 to 2000 ppm by weight of propionic acid esters with the alcohol of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters defined in claim 4 present in the mixture. e. 1 to 2000 ppm by weight of acetate esters with alcohols of each (meth)acrylic acid ester, in each case relative to the total weight of the (meth)acrylic acid esters as defined in claim 4 present in the mixture; f. The mixture according to any one of claims 3 to 5, comprising from 0 to 2000 ppm by weight of one or more ethers of the respective (meth)acrylic acid ester alcohols, in each case relative to the total weight of the (meth)acrylic acid esters defined in claim 4 present in the mixture.

7. 7. The mixture according to claim 1, wherein the mixture is stored and / or transported under an oxygen-containing atmosphere.

8. 8. The mixture of claim 1, wherein the mixture comprises a costabilizer.

9. (Meth)acrylic acid and / or C 1 From C 8 10. Use of one or more compounds of general formula (II) as defined in claim 1 for the storage and / or transport stabilization of alkyl(meth)acrylates.

10. (meth)acrylic acid and / or C in the presence of one or more compounds of general formula (II) as defined in claim 1 1 From C 8 A process for polymerizing alkyl (meth)acrylates, wherein the reaction mixture is 0 to 50% saturated with oxygen, where oxygen saturation means the oxygen saturation achieved at equilibrium when the mixture is stored and / or transported under standard conditions in an oxygen-containing atmosphere having an oxygen content of 5 to 30 vol%.

11. Through the use of one or more compounds of general formula (II) as defined in claim 1, (meth)acrylic acid and / or C 1 From C 8 A method for stabilizing alkyl (meth)acrylates.

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