Stabilization of Α-methylenelactones

Abstract

The invention relates to a process for production and / or storage of α-methylenelactones, wherein a α- methylenelactone is present in a vessel, the α-methylenelactone is a α-methylenelactone of the following Formula I: and R1 is hydrogen, or a C1 to C10, in particular C1 to C5, linear or branched alkyl group, in particular R1 is hydrogen or a methyl group, and the vessel contains a gaseous phase and a liquid phase, wherein the gaseous phase comprises less than 15 vol.-%, based on the total gaseous phase, of oxygen, and the liquid phase comprises - 50.0000 wt.-% to 99.9995 wt.-%, based on the total liquid phase, of the α-methylenelactone, - 0.0000 wt.-% to 49.9995 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2-methylene-4-ol-butyric acid, hydroxycarboxylic esters such as γ-butyrolactone, water, further monomers, and / or organic solvents, and - 0.0005 wt.-% to 0.2000 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II: and R2 is hydrogen, oxygen, OH NH2, OMe or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

Description

[0001] 231160W001

[0002] 1

[0003] Stabilization of o-methylenelactones

[0004] Description

[0005] The present invention relates to a process for production and / or storage of o-methylenelactones, wherein a o- methylenelactone is present in a vessel, the o-methylenelactone is a o-methylenelactone of the following Formula I and R1is hydrogen or a Ci to C10 linear or branched alkyl group and the storage vessel contains a gaseous phase and a liquid phase. The invention further relates to the use of the o-methylenelactone and a system for production and / or storage of o-methylenelactones. o-Methylenelactones are acrylic ester monomers and for example used in polymer latices, also referred to as polymer dispersions, which are commonly known in particular as binder or binder component, also termed co-binder, for coating compositions. In coating compositions, one of the important requirements is that they provide hardness to the coatings and adherence of the coating to the coated surface. Furthermore, optical qualities such as flexibility in coloration and therefore a colorless monomer as well as polymer are required.

[0006] The o-methylenelactone tulipalin (o-methylene-y-butyrolactone) for example is a naturally occurring vinyl monomer found in tulips. Tulipalin functions as defensive chemical in plants.

[0007] Tulipalin's exo-methylene double bond allows for polymerization of the monomers to form the polymeric compound poly(tulipalin). Tulipalin polymerizes in a manner similar to methyl methacrylate (MMA), a monomer used in the production of polymethyl methacrylate acrylic plastics (PMMA), also known as acrylic glass, Perspex or Plexiglas, and methacrylate-butadiene-styrene (MBS). Hence, tulipalin is considered a cyclic analog of methyl methacrylate and has the potential to replace fossil MMA or styrene monomers as a sustainable alternative. As a naturally occurring vinyl, tulipalin lends a reduced carbon footprint, biocompatibility and eco-friendly and renewable characteristics to the resulting polymers. Tulipalin readily copolymerizes with copolymerizing agents such as styrene, methacrylate and acrylate monomers, acrylic acid, methacrylic acid or acrylonitrile. In polymer producing industries, tulipalin can be potentially used in the production of materials such as coatings, films, paints, adhesives, plastics, resins, dispersions, rubber and / or sealants. Due to its potential as a sustainable alternative to fossil methyl methacrylate or styrene, tulipalin can be an important future industrial monomer. Hence, there is a need for an improved method for stabilizing tulipalin on an industrial scale during production, storage and transport.

[0008] Before use, in particular during synthesis, purification and storage, of the o-methylenelactone, care has to be taken that spontaneous polymerization is prevented as otherwise high polymerization energies are released and a save 231160W001

[0009] 2 handling of the o-methylenelactone in a production process and during storage and transport is not possible. The stability of the liquid o-methylenelactone monomer has to be ensured and improved without interference with desired properties profiles, in particular under preservation of colorlessness.

[0010] The preparation of o-methylenelactones and o-substituted hydrocarbylidene lactones is described in US 6,531 ,616 B2. A liable stabilization, in particular a stabilization also suitable for storage and transport of o-methylenelactones, where a stability for a longer period of time is required, is not addressed.

[0011] JP 2009-179610 A discloses a stabilization method of a composition containing a methylene lactone without further specification of the gaseous phase.

[0012] Apart from that and in view of the ongoing discussion about the impact of CO2 emissions, there is a demand of replacing at least partly fossil by bio-based carbon in monomers and thereby polymers. The term bio-based means that the monomers are at least partly prepared from renewable raw materials, such as plants, parts of plants, plant waste, biomass or the like. These products are referred to as bio-based and are characterized by having a traceable content of14C carbon. It is also possible that these materials are converted into suitable industrial feeds, such as bionaphtha. Such feeds typically enter the chemical production system, such as a steam cracker, where they are converted into products along the chemical value chain, such as acrylic acid, methacrylic acid, acrylic esters, methacrylic esters and others. The content of renewable material of these products is defined by the mass balance approach and can be allocated to these products.

[0013] Bio-based a-methylene-y-butyrolactone can be synthesized for example completely bio-based from carbohydrates as further described in WO 2023 / 052538 A1 .

[0014] Due to its potential as a sustainable alternative to methyl methacrylate, tulipalin has the potential to be an important industrial polymer. Hence, there is a need for an improved and save method for producing tulipalin on an industrial scale.

[0015] It was an object of the present invention to provide a process and a system to obtain a stable monomer liquid phase, which can be produced at least partly from renewable resources.

[0016] The problem is solved by a process for production and / or storage of o-methylenelactones, wherein a o- methylenelactone is present in a vessel, the o-methylenelactone is a o-methylenelactone of the following Formula I: 231160W001 and R1is hydrogen, or a Ci to C10, preferably Ci to C5, more preferably Ci to C4, linear or branched alkyl group, in particular R1is hydrogen or a methyl group, and the vessel contains a gaseous phase and a liquid phase, wherein the gaseous phase comprises less than 15 vol .-%, preferably less than 4 vol.-%, more preferably less than 1 vol.-%, even more preferably less than 0.1 vol.-%, even more preferably less than 0.01 vol.-%, even more preferably less than 0.001 vol .-%, even more preferably less than 0.0005 vol.-%, based on the total gaseous phase, of oxygen, and the liquid phase comprises or consists of

[0017] 50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the o-methylenelactone,

[0018] 0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2- methylene-4-ol-butyric acid, hydroxycarboxylic esters such as y-butyrolactone, water, further monomers, and / or organic solvents, and

[0019] 0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II: and R2is hydrogen, oxygen, OH, NH2, a methoxy group (OMe) or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

[0020] The invention further relates to the use of the o-methylenelactone produced and / or stored by the process according to the invention for production of coatings, films, paints, adhesives, plastics, resins, dispersions, rubber and / or sealants.

[0021] The invention also relates to use of the liquid phase comprising or consisting of

[0022] 50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the o-methylenelactone of the following Formula I: 231160W001

[0023] 4 wherein R1is hydrogen, or a Ci to C10, in particular Ci to C5, linear or branched alkyl group, in particular R1is hydrogen or a methyl group,

[0024] 0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2- methylene-4-ol-buty ric acid, hydroxycarboxylic esters such as y-buty rolactone, water, further monomers, and / or organic solvents, and

[0025] 0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II: and R2is hydrogen, oxygen, OH, NH2, a methoxy group (OMe) or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, for production of coatings, films, paints, adhesives, plastics, resins, dispersions, rubber and / or sealants.

[0026] Preferably the liquid phase is submitted to a polymerization step, wherein in particular a radical or ionic polymerization initiator is added and the liquid phase is heated to a polymerization temperature of more than 40°C, in particular more than 50°. In particular, the polymerization step is carried out in the presence of the polymerization inhibitor. The polymerization step is preferably carried out in the presence of the gaseous phase.

[0027] The problem is further solved by a system for production and / or storage of o-methylenelactones, comprising a vessel, wherein the o-methylenelactone is a o-methylenelactone of the following Formula I and R1is hydrogen, or a Ci to C10, preferably Ci to C5, more preferably Ci to C4, linear or branched alkyl group, in particular hydrogen or a methyl group, and the vessel contains a gaseous phase and a liquid phase, wherein the gaseous phase comprises less than 15 vol .-%, preferably less than 4 vol.-%, more preferably less than 1 vol.-%, even more preferably less than 0.1 vol.-%, even more preferably less than 0.01 vol.-%, even more preferably less 231160W001

[0028] 5 than 0.001 vol even more preferably less than 0.0005 vol based on the total gaseous phase, of oxygen, and the liquid phase comprises or consists of

[0029] 50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the a-methylenelactone,

[0030] 0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2- methylene-4-ol-butyric acid, hydroxycarboxylic esters such as y-butyrolactone, water, further monomers, and / or organic solvents, and

[0031] 0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II: and R2is hydrogen, oxygen, OH, NH2, a methoxy group (OMe) or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

[0032] In a preferred embodiment, the polymerization inhibitor is 4-hydroxy-2,2,6,6-tetramethylpiperidin-1 -oxyl.

[0033] By presence of the polymerization inhibitor, in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, in the defined concentrations and the presence of said gaseous phase, the a-methylenelactone is stabilized effectively. Only small amounts of the polymerization inhibitor, in particular 4-hydroxy-2, 2, 6, 6-tetramethylpiperidin-1 -oxyl, are required to achieve a reliable long-term stabilization of the liquid monomer. Further, the a-methylenelactone can be produced at least partially from biomass. Preferably, the a-methylenelactone is a bio-based monomer.

[0034] 4-hydroxy-2,2,6,6-tetramethylpiperidin-1 -oxyl is also referred to as HO-Tempo. In particular, the 4-hydroxy-2, 2,6,6- tetramethylpiperidin-1-oxyl is used as stabilizer, also referred to as polymerization inhibitor.

[0035] Here and throughout the specification, the term "(meth)acryl” includes both acryl and / or methacryl groups. Hence, the term "(meth)acrylate” includes acrylate and / or methacrylate.

[0036] Here and throughout the specification, the terms wt.-% and % by weight are used synonymously. 231160W001

[0037] 6

[0038] Here and throughout the specification, the term "bio-based monomer” means that the respective monomer is at least partly produced from molecules which are obtained from a bio-renewable resource, such as biomass. Such molecules are characterized by a content of bio-carbon of at least 90 mol-%, preferably at least 95 mol-%, e.g. 100 mol-%, based on the total amount of carbon atoms.

[0039] The term "bio-carbon” indicates that the carbon is of biological origin and comes from a biomaterial or renewable resources, respectively. Here and in the following renewable sources and bio-renewable sources are used synonymously and refer to sources of biological origin other than fossil sources. The content in bio-carbon and the content in biomaterial are expressions that indicate the same value. A material of renewable origin or biomaterial is an organic material wherein the carbon comes from the CO2 fixed recently (on a human scale) by photosynthesis from the atmosphere. A biomaterial (carbon of 100% natural origin) has an isotopic ratio14C / 12C greater than 10-12, typically about 1 .2* 10-12, while a fossil material has a zero ratio. Indeed, the isotopic14C is formed in the atmosphere and is then integrated via photosynthesis, according to a time scale of a few tens of years at most. The half-life of the14C is 5,730 years. Thus, the materials coming from photosynthesis, namely plants in general, necessarily have a maximum content in isotope14C. The determination of the content of biomaterial or of bio-carbon can be carried out in accordance with the standards ASTM D 6866-12, the method B (ASTM D 6866-06) and ASTM D 7026 (ASTM D 7026-04).

[0040] Here and throughout the specification, the prefixes Cn-Cmused in connection with compounds or molecular moieties each indicate a range for the number of possible carbon atoms that a molecular moiety or a compound can have. The term "Ci-Cnalkyl" denominates a group of linear or branched saturated or unsaturated hydrocarbon radicals having from 1 to n carbon atoms.

[0041] The term C1-C10 alkyl denominates a group of linear or branched saturated or unsaturated hydrocarbon radicals having from 1 to 10 carbon atoms. For example, the term C1-C4 alkyl denominates a group of linear or branched saturated hydrocarbon radicals having from 1 to 4 carbon atoms. Examples of alkyl include but are not limited to methyl, ethyl, n-propyl, isopropyl, 1 -methylethyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 1 -methylpropyl, 2- methylpropyl, 1 ,1 -dimethylethyl, pentyl, 1 -methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1 -ethylpropyl, hexyl, 1 , 1 -dimethylpropyl, 1 ,2-dimethylpropyl, heptyl, octyl, nonyl, decyl, 1 -ethyl propyl, 2-methyl-2-propen-1-yl, penten-1-yl, 2,6-dimethyl-5-hepten-1 -yl or 2,6-dimethyl-1 ,5-heptadien-1-yl. Preferably, R1is hydrogen, or a Ci to C4 alkyl group. Examples of Ci-C4-alkyl are for example methyl, ethyl, propyl, 1 -methylethyl, butyl, 1 -methyl propyl, 2- methylpropyl or 1 ,1 -dimethylethyl.

[0042] The a-methylenelactone is preferably a-methylene-y-butyrolactone. a-Methylene-y-butyrolactone is also referred to as alpha-methylene-gamma-butyrolactone, 2-methylene-y-butyrolactone, 3-methylideneoxolan-2-one or tulipalin. Methylene-y-butyrolactones, such as a-methylene-y-butyrolactone have an exocyclic double bond which is susceptible to a radical polymerization. 231160W001

[0043] 7

[0044] In a preferred embodiment, the liquid phase comprises 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, even more preferably 0.0005 wt.-% to 0.0060 wt.-%, even more preferably 0.0005 wt.-% to 0.0025 wt.-%, based on the total liquid phase, of the polymerization inhibitor.

[0045] The liquid phase comprises even more preferably 0.0010 wt.-% to 0.0100 wt.-%, 0.0010 wt.-% to 0.0090 wt.-%, even more preferably 0.0010 wt.-% to 0.0075 wt.-% and even more preferably 0.0015 wt.-% to 0.0060 wt.-%, based on the total liquid phase, of the polymerization inhibitor.

[0046] A mass ratio in the liquid phase between the polymerization inhibitor and the o-methylenelactone is preferably less than 11 xioA-5 (I MO5), more preferably less than 8x10A-5, even more preferably less than 6x10A-5, even more preferably less than 3x10A-5. A mass ratio in the liquid phase between the polymerization inhibitor and the a- methylenelactone is preferably in a range from 0.01 x10A-5 to 11 x10A-5, more preferably from 0.05x10A-5 to 8x10A-5, even more preferably from 0.1 x10A-5 to 6x10A-5, even more preferably from 0.1 x10A-5 to 3x10A-5.

[0047] In a preferred embodiment, the liquid phase comprises 98.0000 wt.-% to 99.9994 wt.-% of the o-methylenelactone, 0.0001 wt.-% to 1 .9900 wt.-% of residuals and 0.0005 wt.-% to 0.0100 wt.-% of the polymerization inhibitor, based on the total liquid phase.

[0048] The residuals in the liquid phase preferably comprise or consists of carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2-methylene-4-ol-butyric acid, hydroxycarboxylic esters such as y-butyrolactone, water, further monomers, and / or organic solvents.

[0049] The residuals are in particular different from the o-methylenelactone and the polymerization inhibitor. The further monomers can comprise or be selected from for example C2-Cio-al ky I (meth)acrylates or C2-C4-al ky I (meth)acrylates, in particular methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate or 2-ethyl-hexyl (meth)acrylate; monoethylenically unsaturated nitriles, such as acrylonitrile and / or vinylaromatic monomers such as styrene. The organic solvents can comprise or be selected from for example alkanes, alkenes, ketones, substituted aromatic hydrocarbons such as toluene, carboxylate ester such as acetates, and / or alcohols. The organic solvents can comprise or be selected from for example heptane, ethyl acetate, cylohexanol and / or 2-tertiary butylphenol. The carboxylic acids can comprise or be selected from for example itaconic acid and / or (meth)acrylic acid. The residuals can further comprise carboxylic esters such as itaconic acid methyl ester, aldehydes such as formaldehyde and / or dimers such as a dimer of o-methylene-y-butyrolactone.

[0050] Further, the residuals can comprise for example substituted methylene lactones, substituted 4-hydroxy-2- methylenebutanoic acid, and / or acids of the following Formulas III and IV, respectively: 231160W001

[0051] The vessel is in particular a reactor, a column, buffer container and / or a storage tank. The polymerization inhibitor, in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, can be present during synthesis, purification, storage, transport and / or polymerization of the o-methylenelactone.

[0052] The gaseous phase is preferably in contact with the liquid phase, more preferably in direct contact. In particular, the process comprises a step of contacting the gaseous phase with the liquid phase.

[0053] The liquid phase is preferably at least partly a continuous phase. The gaseous phase is preferably a continuous phase and / or a dispersed phase. The liquid phase can be flushed, in particular continuously, with the gaseous phase.

[0054] Particularly, the gaseous phase comprises less than 1.0 vol.-%, more particularly less than 0.1 vol.-%, for example less than 0.01 vol.-%, more preferably less than 0.001 vol .-%, even more preferably less than 0.0005 vol .-%, of oxygen, referring to the total gaseous phase. Oxygen is preferably absent in the gaseous phase. By the defined composition of the gaseous phase with reduced or highly reduced oxygen content or even absence of oxygen, respectively, the liquid phase is stabilized effectively.

[0055] Preferably, the gaseous phase consists to more than 85 vol.-%, more preferably to more than 96 vol .-%, even more preferably to more than 99 vol.-%, of an inert gas, in particular argon and / or nitrogen, referring to the total gaseous phase.

[0056] The process according to the invention preferably further comprises at least one of the following steps: a) synthesizing the o-methylenelactone, wherein the o-methylenelactone is obtained in a crude product solution, b) purifying the o-methylenelactone, in particular the crude product solution, wherein a purified product solution comprising the o -methylenelactone is obtained, c) transferring the o-methylenelactone, in particular the purified product solution, into the vessel, in particular a storage tank, and storage of the o-methylenelactone in the vessel, d) polymerizing the o-methylenelactone, wherein a radical or ionic polymerization initiator is added and the o-methylenelactone is heated to a polymerization temperature of more than 40°C, in particular more than 50°, 231160W001

[0057] 9 wherein the crude product solution is a first liquid phase and / or the purified product solution is a second liquid phase.

[0058] The process of the invention can comprise only one step or any combination of two or three steps or all steps of steps a) to d). Steps a), b), c) and / or d) are preferably performed in the given order.

[0059] The polymerization inhibitor is preferably added in step a), b) and / or c). The polymerization inhibitor can be added in at least two steps of steps a) to c).

[0060] Preferably, the polymerization in step d) is performed until a conversion of at least 75% is reached. The radical or ionic polymerization initiator is preferably a radical polymerization initiator and more preferably 2,2'-azobis(2- methylpropionitrile) (AIBN), sodium persulfate or a redox initiator.

[0061] The polymerization inhibitor can be present in the liquid phase during synthesizing and / or purifying the a- methylenelactone and / or be added to the o-methylenelactone after synthesizing and / or purifying. The liquid phase can be the crude product solution and / or the purified product solution. In particular, the crude product solution is a first liquid phase and / or the purified product solution is a second liquid phase. The first liquid phase and the second liquid phase can have same or different compositions, preferably different compositions.

[0062] Preferably, the o-methylenelactone is synthesized in presence of the polymerization inhibitor, in particular in presence of 0.0005 wt.-% to 0.2000 wt.-%, more preferably 0.0005 wt.-% to 0.1000 wt.-%, even more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, even more preferably 0.0005 wt.- % to 0.0060 wt.-%, even more preferably 0.0005 wt.-% to 0.0025 wt.-%, of the polymerization inhibitor, based on the crude product solution.

[0063] Preferably, the o-methylenelactone is purified in presence of the polymerization inhibitor, in particular in presence of 0.0005 wt.-% to 0.2000 wt.-%, more preferably 0.0005 wt.-% to 0.1000 wt.-%, even more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, even more preferably 0.0005 wt.-% to 0.0060 wt.- %, even more preferably 0.0005 wt.-% to 0.0025 wt.-%, of the polymerization inhibitor, based on the purified product solution.

[0064] In particular, the polymerization is carried out in presence of the polymerization inhibitor. More preferably, the polymerization is carried out in presence of 0.0005 wt.-% to 0.2000 wt.-%, more preferably 0.0005 wt.-% to 0.1000 wt.-%, even more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, even more preferably 0.0005 wt.-% to 0.0060 wt.-%, even more preferably 0.0005 wt.-% to 0.0025 wt.-%, of the polymerization inhibitor, based on the liquid phase. The polymerization is preferably carried out in the presence of the gaseous phase. 231160W001

[0065] 10

[0066] Synthesis a-Methylenelactones, such as a-methylene-y-butyrolactone, are commercially available. a-Methylenelactones, in particular a-methylene-y-butyrolactone, can be synthesized by lactonization of itaconic acid or itaconic acid methyl ester. In another embodiment, a-methylenelactones, in particular a-methylene-y- butyrolactone, can be synthesized by condensation of y-butyrolactone, in particular of 3-acy l-y-buty rolactone, with for example formaldehyde and / or paraformaldehyde. The condensation, which is in particular deacylating, is preferably induced by potassium carbonate. 3-acyl-y-butyrolactone can be formed for example by reaction of y-butyrolactone with diethyloxalate, alkylacetate or alkylformiate.

[0067] For example a-methylene-y-butyrolactone can be prepared from ethyl-oxalyl-y-butyrolactone sodium salt. In a preferred embodiment diethyl oxalate and y-butyrolactone, preferably in ethanol, are heated to a temperature of at least 50°C, more preferably to a temperature in a range from 55°C to 75°C, for example 65°C. Preferably, a solution of sodium methoxide, in particular in methanol, is added under agitation resulting in a first product mixture. The first product mixture is preferably cooled to a temperature of less than 30°C, for example to 25°C. The first product mixture, containing the ethyl-oxalyl-y-butyrolactone sodium salt, is preferably filtered, and a resulting solid cake, containing the ethyl-oxalyl-y-butyrolactone sodium salt, is optionally washed with ethanol and further optionally dried. The resulting solid cake is preferably dried, in particular for at least 2 hours, more preferably for at least 20 hours, under nitrogen at a temperature in a range from 20°C to 50°C, more preferably from 35°C to 45°C.

[0068] Preferably, the ethyl-oxalyl-y-butyrolactone sodium salt is mixed with potassium carbonate, water and methylene chloride, in particular under the gaseous phase of the invention, for example under nitrogen. The resulting second product mixture is preferably cooled to a temperature of less than 20°C, more preferably less than 15°C, for example to 10°C. Preferably, formaldehyde in water is added to the second product mixture. A resulting slurry is preferably filtered, wherein an organic phase, comprising the methylene chloride, of a resulting filtrate contains the a-methylene- y- butyrolactone. The polymerization inhibitor is preferably added to the organic phase of the resulting filtrate. The methylene chloride is preferably removed, for example by application of at least partial vacuum. A distillation step can follow.

[0069] US 2006 / 0084818 A1 discloses a method of producing unsubstituted and substituted alpha-methylene lactones by a gas phase reaction of starting lactones with formaldehyde in the presence of a catalyst derived from a hydrotalcite. a-Methylenelactones can be biobased, I. e. they can be obtained from biological sources. a-Methylene-y- butyrolactone can be produced from tetrahydro-3-furoic acid as described in US 6,362,346 B1 .

[0070] The a-methylenelactone can be synthesized by enzymatic conversion. a-Methylene-y-butyrolactone can be produced from itaconic acid by the process described in WO 2023 / 052538 A1 . The process includes the enzymatic 231160W001

[0071] 11 reduction of itaconic acid to 2-methylene-4-hydroxybutanoic acid which spontaneously lactonizes internally to 2- methylene-y-butyrolactone. The process includes the enzymatic production of Itaconyl-CoA, e. g. by using an acyl- CoA synthetase or a CoA transferase followed by the reaction with an oxidoreductase, e. g. an Acyl-CoA reductase, whereby itaconic acid semi-aldehyde is formed. Alternatively, itaconic acid semi-aldehyde can be obtained directly from itaconic acid by reaction with a carboxylic acid reductase. The itaconic acid semi-aldehyde is then reacted with an oxidoreductase, in particular an alcohol dehydrogenase or a 3-sulfolactaldehyde reductase to obtain 2-methylene- 4-hydroxybutanoic acid which spontaneously forms a-methylene-y-butyrolactone. In some cases a further enzyme for lactonization may be required, e.g. a thioesterase or a lactonase. For example, 2-methylene-4-hydroxybutyric- CoA may be obtained, depending on the enzyme used in the first step. In this case, 2-methylene-4-hydroxybutyric- CoA will be reacted with a thioesterase to obtain a-methylene-y-butyrolactone. The starting material itaconic acid can be produced by biotechnological processes from carbohydrates, such as glucose or glucose containing raw materials. A review is given by M. Okabe et al., Biotechnological Production of Itaconic Acid and its Biosynthesis from Aspergillus terreus, in Applied Microbiology and Biotechnology 84 (4), 2009, pp. 597 to 606 and by Garabed Antranikian in Angewandte Mikrobiologie, Springer-Verlag, Berlin / Heidelberg 2006, ISBN 3-540-24083-7, pp. 351 to 352.

[0072] Preferably, fermentation is involved in synthesizing the a-methylenelactone.

[0073] The term fermentation refers to a process which converts sugars, such as glucose, into cellular energy under anaerobic conditions, producing adenosine triphosphate (ATP), fermentation product and CO2. A fermentation product is one of the products of the fermentation process including organic acids or alcohols.

[0074] In particular, the a-methylenelactone is synthesized from a product of fermentation of a carbohydrate source selected from the group consisting of cellulose, hemicellulose, starch, sucrose, glucose, fructose, lactose, corn syrup, molasses, sugar beets, sugar cane and / or sugar palm.

[0075] In a preferred embodiment, at least one enzymatically catalyzed reaction step, more preferably three enzymatically catalyzed reaction steps, are involved in synthesizing the a-methylenelactone. Preferably, the a-methylenelactone, in particular a-methylene-y-butyrolactone, is synthesized from itaconic acid. In a preferred embodiment, the itaconic acid is derived from fermentation of a carbohydrate source selected from the group consisting of cellulose, hemicellulose, starch, sucrose, glucose, fructose, lactose, corn syrup, molasses, sugar beets, sugar cane and / or sugar palm. Preferably, the itaconic acid is derived from fermentation of a carbohydrate source derived from a raw material comprising cellulose, hemicellulose and / or starch.

[0076] More preferably, the synthesis of a-methylene-y-butyrolactone involves contacting a reaction mixture comprising itaconic acid with a first enzyme selected from at least one acyl-CoA synthetase, at least one CoA-transferase and at least one carboxylic acid reductase. In a preferred embodiment, the acyl-CoA synthetase is selected from the group 231160W001

[0077] 12 consisting of succinyl-CoA synthetase (SucCD) and malate-CoA ligase (MtkAB). In another embodiment, the CoA- transferase is Itaconate-CoA transferase (let).

[0078] Further, the synthesis of a-methylene-y-butyrolactone preferably involves contacting the reaction mixture with a second enzyme, wherein the second enzyme is at least one oxidoreductase, preferably an acyl-CoA reductase. In one embodiment, the oxidoreductase is an acyl-CoA reductase, preferably selected from succinyl-CoA reductase (Scr) and malonyl-CoA reductase (Mcr).

[0079] Further, the synthesis of a-methylene-y-butyrolactone preferably involves contacting the reaction mixture with a third enzyme, wherein the third enzyme is at least one oxidoreductase selected from the group consisting of alcohol dehydrogenase, lactaldehyde reductase, 3-sulfolactaldehyde reductase, succinate semialdehyde reductase and aldose / aldehyde reductase.

[0080] Further, the synthesis of a-methylene-y-butyrolactone might involve contacting the reaction mixture with a fourth enzyme selected from at least one thioesterase and at least one lactonase.

[0081] One or more, or all, steps of synthesis of a-methylene-y-butyrolactone may take place in a cell or organism comprising at least one of the enzymes.

[0082] Further details of the enzymatic pathway are described in WO 2023 / 052538 A1 .

[0083] Preferably, one step of the a-methylene-y-butyrolactone synthesis is cyclic esterification of 2-methy lene-4-ol-buty ric acid to form a-methylene-y-butyro-lactone. Lactones are formed by intramolecular esterification of hydroxycarboxylic acids, which takes place spontaneously if the ring that is formed is five- or six-membered.

[0084] Preference is given to a-methylenelactones, such as a-methylene-y-butyrolactone, which are bio-based and preferably have a content of bio-carbon of at least 90 mol-%, in particular at least 95 mol-% or at least 98 mol%, e.g. 100 mol-%, based on the total amount its of carbon atoms.

[0085] The polymerization inhibitor is preferably present or added in the synthesis step and / or purification step, when the a- methylenelactone is formed and / or concentrated. More preferably, the polymerization inhibitor is preferably added to a product mixture comprising at least 50 wt.-%, even more preferably at least 70 wt.-%, of the a-methylenelactone, based on the total product mixture, wherein the product mixture is the liquid phase.

[0086] Purification 231160W001

[0087] 13

[0088] In particular after completion of the enzymatic route of synthesis, the o-methylenelactone may be isolated by known methods, in particular by using organic solvents such as heptane, ethyl acetate, cylohexanol and / or 2-tertiary butylphenol. Preferably, the o-methylenelactone is isolated using heptane and 2-tertiary butylphenol.

[0089] In a preferred embodiment, the o-methylenelactone is purified by distillation, in particular steam distillation. In particular, the crude product solution is purified by distillation. Purifying the o-methylenelactone can comprise one or at least two distillation steps. The distillation can be performed batch-wise or continuously. The distillation is preferably performed in counter-current mode. Preferably a distillation bottom temperature is in a range from 40°C to 120°C, more preferably from 90°C to 120°C, in particular at a distillation bottom pressure in a range from 0.1 hPa to 150 hPa, preferably from 50 hPa to 120 hPa. Preferably a distillation top temperature is in a range from 40°C to 90°C, more preferably from 60°C to 80°C, in particular at a distillation top pressure in a range from 1 hPa to 100 hPa, preferably from 40 hPa to 80 hPa.

[0090] The vessel can be a column, in particular a distillation column, which might comprise separating internals such as packings or plates.

[0091] Further, the o-methylenelactone can be purified by melt crystallization. For melt crystallization the o- methylenelactone is in particular cooled to a temperature of less than - 35°C.

[0092] Storage

[0093] The vessel is in particular a storage tank. Preferably the vessel has an inner volume of at least 0.001 m3, more preferably in a range from 0.001 m3to 500.000 m3, even more preferably from 0.001 m3to 50.000 m3. The vessel comprises for example 70 vol.-% to 98 vol.-%, preferably 90 vol.-% to 95 vol.-%, of the liquid phase and 2 vol.-% to 30 vol.-%, preferably 5 vol.-% to 10 vol .-%, of the gaseous phase, based on the total inner volume of the vessel.

[0094] Preferably, the liquid phase in the vessel has a temperature in a range from - 20°C to 45°C, more preferably, in particular during storage, in a range from 10°C to 25°C.

[0095] Preferably, the o-methylenelactone is stored in the vessel for a duration of at least 24 hours. In one embodiment, the vessel containing the gaseous phase and the liquid phase is transported from a first location to a second location, for example by truck, ship and / or train.

[0096] Polymerization

[0097] The o-methylenelactone is preferably polymerized by adding a polymerization initiator. The polymerization initiator is preferably a, in particular water- or oil-soluble, radical or ionic polymerization initiator. The amounts of the polymerization initiator will generally not exceed 5 wt.-%, and, if present, are typically present in the range from 0.01 231160W001

[0098] 14 to 2.00 wt.-%, especially from 0.02 to 1 .00 wt.-%, based on the total amount of monomers to be polymerized (the a- methylenelactone).

[0099] Polymerizing the o-methylenelactone in step d) is preferably effectuated by emulsion polymerization, in particular radically initiated aqueous emulsion polymerization. The procedure for radically initiated emulsion polymerization of monomers in an aqueous medium has been described for example in Emulsion Polymerization in Encyclopedia of Polymer Science and Engineering, vol. 8, pages 659 ff. (1987); D.C. Blackley, in High Polymer Latices, vol. 1, pages 35 ff. (1966); H. Warson, The Applications of Synthetic Resin Emulsions, chapter 5, pages 246 ff. (1972); D. Diederich, Chemie in unserer Zeit 24, pages 135 to 142 (1990); Emulsion Polymerisation, Interscience Publishers, New York (1965); DE-A 40 03422; and Dispersionen synthetischer Hochpolymerer, F. Hblscher, Springer-Verlag, Berlin (1969).

[0100] In case of free-radically initiated aqueous emulsion polymerization the polymerization initiator is preferably a, in particular water-soluble, free-radical polymerization initiator. These may, in principle, be peroxides or azo compounds. Of course, redox initiator systems are also applicable. Peroxides used may, in principle, be inorganic peroxides such as hydrogen peroxide or peroxodisulfates such as the mono- or di-alkali metal or ammonium salts of peroxodisulfuric acid, for example the mono- and disodium, potassium or ammonium salts. Preferred free-radical initiators are inorganic peroxides, especially peroxodisulfates.

[0101] The aqueous radical emulsion polymerization is usually performed in the presence of one or more suitable surfactants. These surfactants typically comprise emulsifiers and provide micelles, in which the polymerization occurs, and which serve to stabilize the monomer droplets during aqueous emulsion polymerization and also growing polymer particles. The surfactants used in the emulsion polymerization are usually not separated from the polymer dispersion, but remain in the aqueous polymer dispersion obtainable by the emulsion polymerization of the a - methylenelactone.

[0102] The surfactant may be selected from emulsifiers and protective colloids. Protective colloids, as opposed to emulsifiers, are understood to mean polymeric compounds having molecular weights above 2000 Daltons, whereas emulsifiers typically have lower molecular weights. The surfactants may be anionic or nonionic or mixtures of nonionic and anionic surfactants. Anionic surfactants usually bear at least one anionic group which is typically selected from phosphate, phosphonate, sulfate and sulfonate groups. The anionic surfactants which bear at least one anionic group are typically used in the form of their alkali metal salts, especially of their sodium salts or in the form of their ammonium salts. Preferably, the surfactant will be used in such an amount that the amount of surfactant is in the range from 0.2 to 5.0 wt.-%, especially in the range from 0.3 to 4.5 wt.-%, based on the total monomers to be polymerized.

[0103] It has been found advantageous to perform the aqueous radical emulsion polymerization of the o-methylenelactone in the presence of a seed latex. A seed latex is a polymer latex which is present in the aqueous polymerization 231160W001

[0104] 15 medium before the polymerization of the o-methylenelactone is started. The seed latex may help to better adjust the particle size or the final polymer dispersion obtained in the aqueous radical emulsion polymerization.

[0105] Principally, every polymer latex may serve as a seed latex. Preference is given to seed latices, where the particle size of the polymer particles is comparatively small. In particular, the Z average particle diameter of the polymer particles of the seed latex, as determined by dynamic light scattering (DLS) at 20 °C, is preferably in the range from 10 nm to 80 nm, in particular from 10 nm to 50 nm. Preferably, the polymer particles of the seed latex is made of ethy lenically unsaturated monomers which comprise at least 95 wt.-%, based on the total weight of the monomers forming the seed latex, of one or more monomers selected from the group consisting of C2-Cio-al ky I esters of acrylic acid, in particular ethyl acrylate, n-butyl acrylate, n-hexyl acrylate, n-octyl acrylate, 2-ethyl-hexylacrylate, Ci-C4-alkyl methacrylates such as methyl methacrylate, monoethylenically unsaturated nitriles, such as acrylonitrile and vinylaromatic monomers as defined above such as styrene and mixtures thereof. In particular, the polymer particles of the seed latex is made of ethy lenically unsaturated monomers which comprise at least 95% by weight, based on the total weight of the monomers forming the seed latex, of one or more monomers selected from the group consisting of Ci-C4-alkyl methacrylates such as methyl methacrylate, monoethylenically unsaturated nitriles, such as acrylonitrile and vinylaromatic monomers as defined above such as styrene and mixtures thereof. The amount of seed latex, calculated as solids, may frequently be in the range of 0.01 to 10.00 wt.-%, preferably in the range of 0.05 to 5.00 wt.-%, in particular in the range of 0.05 to 3.00 wt.-%, based on the total weight of the monomers to be polymerized.

[0106] The polymerization of the o-methylenelactone can optionally be conducted in the presence of at least one chain transfer agent. Chain transfer agents are understood to mean compounds that transfer free radicals, and which reduce the molecular weight of the growing chain and / or which control chain growth in the polymerization. Examples of chain transfer agents are aliphatic and / or araliphatic halogen compounds.

[0107] The polymerization, in particular the aqueous radical emulsion polymerization, is preferably carried out at temperatures in the range from 0°C to 170°C, more preferably from 50°C to 100°C, more preferably from 60°C to 95°C and even more preferably form 70°C to 90°C. The polymerization, in particular the aqueous radical emulsion polymerization, can be conducted at a pressure of less than, equal to or greater than 1 atm (atmospheric pressure). Advantageously, the polymerization, in particular the aqueous radical emulsion polymerization, is conducted with exclusion of oxygen, for example under an inert gas atmosphere, for example under nitrogen or argon. In a preferred embodiment, the polymerization is performed under the gaseous phase of the present invention.

[0108] The polymerization may be a single stage polymerization or a multistage polymerization. In a single stage polymerization, the overall composition of the monomers to be polymerized, which are fed to a reactor under polymerization conditions, remains the same or almost the same, while in a multistage emulsion polymerization the overall composition of the monomers to be polymerized, which are fed to the reactor under polymerization conditions, is altered at least once. 231160W001

[0109] 16

[0110] Preferably, the a-methylenelactone is polymerized by copolymerization in step d), wherein a copolymer is obtained. More preferably, a dispersion for which the a-methylenelactone is used, contains the copolymer and an aqueous phase. Preferably, particles of the copolymer contained in the dispersion the a-methylenelactone is used for have a Z average particle diameter, as determined by quasi-elastic light scattering (QELS, ISO 13321 :1996), in the range from 50 nm to 500 nm, in particular in the range from 60 nm to 350 nm. The particle size distribution of the copolymer particles contained in the dispersion may be monomodal. The particle size distribution of the copolymer particles contained in the dispersion may also be polymodal.

[0111] The copolymer may form a single phase or it may form different phases, if the polymer particles contain different copolymers, which differ with regard to their monomer composition. Preferably, the copolymer comprises a polymer phase, which has a glass transition temperature Tg which does not exceed 50°C, in particular is at most 40°C, preferably in the range from -25°C to +50°C, especially in the range from -20°C to +40°C. The glass transition temperature Tg can be determined experimentally by the differential scanning calorimetry (DSC) method according to ISO 11357-2:2013.

[0112] It is frequently advantageous, when the dispersion, obtained on completion of the aqueous radical polymerization of the a-methylenelactone, is subjected to an after-treatment to reduce the residual monomer content. This after- treatment is affected either chemically, for example by completing the polymerization reaction using a more effective free-radical initiator system (known as postpolymerization), and / or physically, for example by stripping the aqueous polymer dispersion with steam and / or inert gas.

[0113] As the (co)polymer contained in the dispersion may contain acidic groups from monomers and optionally from the polymerization initiator, the dispersion obtained by polymerizing the a-methylenelactone is frequently neutralized, in particular prior to formulating it as a coating composition for example. The neutralization of acid groups of the (co)polymer is typically achieved by neutralizing agents known to the skilled of the art after polymerization and / or during the polymerization. For example, the neutralizing agent may be added in a joint feed with the monomers to be polymerized or in a separate feed. Suitable neutralizing agents include organic amines, alkali hydroxides and ammonium hydroxides. In particular, neutralization is achieved by using ammonia and / or alkali hydroxides such as sodium hydroxide or potassium hydroxide.

[0114] According to one group of embodiments, the a-methylenelactone is used for production of a water-borne coating composition, in particular a paint, containing white pigment. As white pigment they include, in particular, titanium dioxide, preferably in the rutile form. With particular preference, the water-borne coating composition comprises a white pigment, more particularly titanium dioxide, preferably in the rutile form, in combination with one or more fillers, such as chalk, talc or mixtures thereof, for example. In another preferred group of embodiments, the a- methylenelactone is used for production of a water-borne coating composition, which is applied as a clear-coat. In contrast to paints, clear-coats are essentially devoid of pigments and fillers. 231160W001

[0115] 17

[0116] The substrates coated with the waterborne coating composition produced from the o-methylenelactone, which is stabilized according to the invention, have excellent color properties as well as hardness, good adhesion properties such as high dry and wet alkyd adhesion and intercoat adhesion, good opacity, good stain removal properties and low dirt pick-up.

[0117] The invention is explained in more detail by the following examples and comparative examples.

[0118] Examples and comparative examples

[0119] One parameter for the tendency of a monomer solution to polymerize is the inhibition period (IP). This factor depends in particular from the monomer, and the optionally added polymerization inhibitor. To measure the IP of inventive and comparative examples the so-called grill test was used. Gas chromatography (GO) vials with a volume of 1 .5 mL were filled with liquid phase and gaseous phase. Directly after preparing the samples, the vials were fixed in a mounting of a drying oven (Nabertherm TR 60 / S with rotary drive) at a defined temperature. With about 12 cycles per minute of the rotary drive, the time until full solidification and thus polymerization, the inhibition period (IP) was measured. For this purpose, the progress of polymerization was monitored with a camera for a subsequent evaluation and determination of the IP. Values are given as a mean of a quintuple determination.

[0120] Where applicable, defined amounts of polymerization inhibitor were added. For measurements under inert atmosphere an argon stream was passed through the sample vials for 90 seconds before closing them.

[0121] Liquid phases of various compositions were exposed to elevated temperatures in presence of different gaseous phases. Stability of the liquid phase was observed over time at hand of visual inspection of the samples with regard to solidification of the sample.

[0122] In all samples the concentration of a-methylene-y-butyrolactone was more than 95 wt.-% in the liquid phase, based on the total liquid phase. As gaseous phase either air, containing 20 vol.-% of oxygen and 80 vol.-% of nitrogen, referring to the total gaseous phase, or an inert gas, containing 100 vol.-% argon, referring to the total gaseous phase, was applied.

[0123] Samples under air underwent a color change of the liquid phase to a red color before polymerization.

[0124] Different potential polymerization inhibitors were tested in the liquid phase to prevent polymerization of a-methylene- y-butyrolactone. The liquid phase either contained phenothiazine (PTZ), 4-methoxyphenol (MeHQ), 2,6-di-tert-butyl- 4-hydroxytoluene (BHT), N,N'-di(butan-2-yl)benzene-1 ,4-diamine (Kerobit BPD) or HO-TEMPO, or was free of potential polymerization inhibitors, and was stored at 100°C or 120°C, respectively. The achieved inhibition periods under the described conditions are summarized in tables 1 and 2. Each data point is the arithmetic mean of a 231160W001

[0125] 18 quintuple sample set. All tested potential polymerization inhibitors were present in the liquid phase in a concentration of 10 ppm (table 1) or 50 ppm (table 2), respectively, based on the total liquid phase.

[0126] Table 1

[0127] Table 2

[0128] Further, the concentration of HO-TEMPO was varied in the liquid phase. Here, the liquid phases were stored at 80°C or 100°C, respectively. The achieved inhibition periods under the different conditions are summarized in table 3. Each data point is the arithmetic mean of a quadruple sample set.

[0129] Table 3 231160W001

[0130] 19

[0131] Polymerization example 1

[0132] Polymerization of a-methylene-y-butyrolactone in butyl acetate stabilized with 10 ppm HO-TEMPO

[0133] A reactor equipped with stirrer, temperature control, nitrogen inlet and several injection possibilities was charged with 261.0 g butyl acetate, 19.6 g of a monomer mixture, comprising a-methylene-y-butyrolactone and 0.001 wt.-%, based on the total monomer mixture, of HO-TEMPO, and 0.1 g 2,2'-azobis(2-methylpropionitril). This initial reaction mixture was purged with nitrogen and heated to 80°C. At 80°C, a feed 1 was added over two hours and a feed 2 was added over three hours. The feed 1 comprised 260.4 g of the monomer mixture, comprising a-methylene-y-butyrolactone and 0.001 wt.-%, based on the total monomer mixture, of HO-TEMPO, in 134.0 g butyl acetate. The feed 2 comprised 1 .3 g 2,2'-azobis(2-methy Ipropionitril) in 24.7 g butyl acetate. After addition of the feed 1 and the feed 2, the reaction mixture was post-polymerized at 80°C for two hours and then cooled down to ambient temperature. A precipitated polymer powder was filtered off, washed thoroughly with methanol and dried.

[0134] A colorless polymer powder was obtained.

[0135] Polymerization example 2

[0136] Emulsion polymer with a-methylene-y-butyrolactone stabilized with 10 ppm HO-TEMPO

[0137] A reactor equipped with stirrer, temperature control, nitrogen inlet and several injection possibilities was charged with 244.3 g deionized water and 27.3 g of a polystyrene seed dispersion with a solid content of 33 wt.-% and a particle diameter of 30 nm. This initial reaction mixture was purged with nitrogen and heated to 85°C. At 85°C, 5.0 g of a feed 2 were added. After 5 min, a feed 1 and the remaining portion of the feed 2 were added over 180 min. The feed 1 comprised 400.5 g deionized water, 18.5 g Dowfax 2A1, 20.8 g Lutensol TO 82, 6.9 g acrylic acid, 13.9 g of an acrylamide solution comprising 50 wt.-% acrylamide in water, 152.7 g of a monomer mixture, comprising a- methylene-y-butyrolactone and 0.001 wt.-%, based on the total monomer mixture, of HO-TEMPO, and 527.4 g isobutyl acrylate. The feed 2 comprised 19.8 g of a sodium persulfate solution comprising 7 wt.-% sodium persulfate in water. After addition of the feed 1 and the feed 2, the reaction mixture was post-polymerized at 85°C for 30 min. Then a feed 3 and a feed 4 were added over 60 min. The feed 3 comprised 6.9 g of a t-butylhydroperoxide solution comprising 10 wt.-% of t-butylhydroperoxide in water. The feed 4 comprised 6.2 g of a Rongalit C solution comprising 10 wt.-% of Rongalit C in water. After addition of the feed 3 and the feed 4, the reaction mixture was cooled down to ambient temperature and neutralized with sodium hydroxide to a pH value in a range from 8 to 9.

[0138] A colorless dispersion was obtained. The dispersion was dried and mixed with dimethylacetamide. A colorless polymer gel was obtained.

Claims

231160W00120Claims1. A process for production and / or storage of o-methylenelactones, wherein a o-methylenelactone is present in a vessel, the o-methylenelactone is a o-methylenelactone of the following Formula I:and R1is hydrogen, or a Ci to C10, in particular Ci to C5, linear or branched alkyl group, in particular R1is hydrogen or a methyl group, and the vessel contains a gaseous phase and a liquid phase, wherein the gaseous phase comprises less than 15 vol .-%, in particular less than 4 vol.-%, based on the total gaseous phase, of oxygen, and the liquid phase comprises50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the o-methylenelactone,0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2-methylene- 4-ol-butyric acid, hydroxycarboxylic esters such as y-butyrolactone, water, further monomers, and / or organic solvents, and0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II:and R2is hydrogen, oxygen, OH, NH2, OMe or an alkyl-, ester- or amide group,231160W00121 wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

2. The process according to claim 1 , further comprising at least one of the following steps: a) synthesizing the o-methylenelactone, wherein the o-methylenelactone is obtained in a crude product solution, b) purifying the o-methylenelactone, in particular the crude product solution, wherein a purified product solution comprising the a -methylenelactone is obtained, c) transferring the o-methylenelactone, in particular the purified product solution, into the vessel and storage of the o-methylenelactone in the vessel, d) polymerizing the o-methylenelactone, wherein a radical or ionic polymerization initiator is added and the o -methylenelactone is heated to a polymerization temperature of more than 40°C, wherein the crude product solution is a first liquid phase and / or the purified product solution is a second liquid phase.

3. The process according to claim 1 or 2, wherein the liquid phase comprises 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of the polymerization inhibitor.

4. The process according to any of claims 1 to 3, wherein the o-methylenelactone is o-methylene-y- butyrolactone.

5. The process according to any of claims 2 to 4, wherein the polymerization inhibitor is added to the o- methylenelactone after synthesizing and / or purifying.

6. The process according to any of claims 2 to 5, wherein the o-methylenelactone is synthesized in presence of the polymerization inhibitor, in particular in presence of 0.0005 wt.-% to 0.2000 wt.-% of the polymerization inhibitor, based on the crude product solution.

7. The process according to any of claims 2 to 6, wherein the o-methylenelactone is purified in presence of the polymerization inhibitor, in particular in presence of 0.0005 wt.-% to 0.2000 wt.-% of the polymerization inhibitor, based on the purified product solution.

8. The process according to any of claims 2 to 7, wherein the crude product solution is purified by distillation.

9. The process according to any of claims 2 to 8, wherein fermentation is involved in synthesizing the a- methylenelactone.

10. The process according to any of claims 1 to 9, wherein the gaseous phase consists to more than 85 vol.-%, in particular more than 96 vol.-%, of an inert gas, in particular argon and / or nitrogen.231160W00111. The process according to any of claims 1 to 10, wherein the liquid phase in the vessel has a temperature in a range from - 20°C to 45°C.

12. The process according to any of claims 1 to 11 , wherein the o-methylenelactone is stored in the vessel for a duration of at least 24 hours.

13. The process according to any of claims 1 to 12, wherein the vessel containing the gaseous phase and the liquid phase is transported from a first location to a second location.

14. Use of the o-methylenelactone produced and / or stored by the process according to any of claims 1 to 13 for production of coatings, films, paints, adhesives, plastics, resins, dispersions, rubber and / or sealants.

15. Use of the liquid phase comprising50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the o-methylenelactone of the following Formula I:wherein R1is hydrogen, or a Ci to C , in particular Ci to C5, linear or branched alkyl group, in particular R1is hydrogen or a methyl group,0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals, in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2-methylene- 4-ol-butyric acid, hydroxycarboxylic esters such as y-butyrolactone, water, further monomers, and / or organic solvents, and0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II:231160W001and R2is hydrogen, oxygen, OH, NH2, OMe or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, for production of coatings, films, paints, adhesives, plastics, resins, dispersions, rubber and / or sealants.

16. System for production and / or storage of o-methylenelactones comprising a vessel, wherein the a- methylenelactone is a o-methylenelactone of the following Formula Iand R1is hydrogen, or a Ci to C10, in particular Ci to C5, linear or branched alkyl group, in particular hydrogen or a methyl group, and the vessel contains a gaseous phase and a liquid phase, wherein the gaseous phase comprises less than 15 vol .-%, in particular less than 4 vol.-%, based on the total gaseous phase, of oxygen, and the liquid phase comprises50.0000 wt.-% to 99.9995 wt.-%, preferably 80.0000 wt.-% to 99.9995 wt.-%, more preferably 90.0000 wt.- % to 99.9994 wt.-%, even more preferably 95.0000 wt.-% to 99.9994 wt.-%, based on the total liquid phase, of the o-methylenelactone,0.0000 wt.-% to 49.9995 wt.-%, preferably 0.0000 wt.-% to 19.9995 wt.-%, more preferably 0.0001 wt.-% to 9.9995 wt.-%, even more preferably 0.0001 wt.-% to 4.9900 wt.-%, based on the total liquid phase, of residuals in particular carboxylic acids such as itaconic acid, hydroxycarboxylic acids such as 2- methylene-4-ol-buty ric acid, hydroxycarboxylic esters such as y-buty rolactone, water, further monomers, and / or organic solvents, and0.0005 wt.-% to 0.2000 wt.-%, preferably 0.0005 wt.-% to 0.1000 wt.-%, more preferably 0.0005 wt.-% to 0.0500 wt.-%, even more preferably 0.0005 wt.-% to 0.0100 wt.-%, based on the total liquid phase, of a polymerization inhibitor, wherein the polymerization inhibitor is an aminoxyl radical of the following Formular II:231160W00124and R2is hydrogen, oxygen, OH, NH2, OMe or an alkyl-, ester- or amide group, wherein the polymerization inhibitor is in particular 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl.

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