Process for synthesizing alkylphenol methacrylate

Abstract

Object of invention is providing a process for synthesizing alkylphenol methacrylate, as product, having the general formula I: C35H34O2 (I), by providing alkylphenol, having the general formula II: C21H30O (II) and methacrylic acid anhydride (MAAH) having the general formula III: C8H10O3 (III) in the presence of at least one of the following catalysts: an alkyl titanate catalyst, a magnesium chloride catalyst, and / or sulfuric acid to a reactor comprising a motorised stirrer at a temperature in the range of 70 °C to 120 °C for a stirring time of at least 2h for this product mixture, wherein at least partially before and / or during the stirring step at least alkylphenol (educt1), MAAH and / or the catalyst are provided to the reactor, wherein MAAH is provided with an excess of at least 1.05, and the catalyst is provided at a concentration of at least 0.2 mol%, wherein the stirring step is followed by a distillation step by using a distillation device, wherein MAAH and the side product methacrylic acid is separated from the product mixture, wherein the catalyst is part of the product mixture, a precipitating step of the catalyst, wherein the catalyst is solidified and cardanol methacrylate is liquified, and a separation step, wherein the precipitated catalyst is separated from cardanol methacrylate.

Description

[0001] Process for synthesizing alkylphenol methacrylate

[0002] The invention provides a process for synthesizing alkylphenol methacrylates, preferably cardanol methacrylate.

[0003] Background:

[0004] Synthesis of cardanol methacrylate is known. According to US 2020 / 0263054 A1 (D2) synthesis of cardanol methacrylate via methacrylic acid anhydride. The document relates to modified cardanol as a reactive diluent for alkyd coatings and claimed is an alkyd coating composition comprising at least one alkyd resin and at least one reactive diluent selected from modified cardanol. In the example section of US 2020 / 0263054, it is described to produce cardanol methacrylate by reacting cardanol with methacrylic acid anhydride in the presence of 4-dimethylaminopyridine. After several extraction steps, filtration, and evaporation of the solvent, the pure cardanol methacrylate was obtained.

[0005] This synthesis has several disadvantages, as, e.g., the use of 4-dimethylaminopyridine which is highly toxic and dangerous to life by contact to skin. The use for industrial scaled production should be avoided. Moreover, the need of six extraction steps is also highly disadvantageous for an industrial production plant making the production overly complex.

[0006] Another synthesis of methacrylated derivates of cardanol is described in US 10,035,754 B2. According to this document, a three-step process is described. Therein, methacrylated cardanol (di) glycidyl ethers were obtained by a first step of synthesizing cardanol glycidyl ether, a second step of epoxidizing glycidyl ether which is then (third step) reacted to the methacrylated cardanol glycidyl ether.

[0007] An alternative process for the synthesis of cardanol methacrylate is described, wherein cardanol methacrylate is used as low viscosity vinyl ester monomer for UV-curable coatings based on renewable material. In the preparation section, the synthesis of cardanol methacrylate, cardanol is reacted with MAAH in dioxan using potassium carbonate as catalyst. After reaction for 3 h under nitrogen gas protection to prevent inhibition by free oxygen radicals, the mixture was vacuum filtrated, and the solvent was evaporated. The residual mixture was then washed with weak alkali and water by using two extraction steps. Finally, the residual water was removed by vacuum distillation. No exact information to yield and purity is made. (“Design, preparation and properties of novel renewable UV-curable copolymers based on cardanol and dimer fatty acids” (Progress in organic Coating, Vol 77 (2014), p. 388-394)

[0008] Disadvantages of this process are the high number of processing steps, such as filtration, distillation, two extractions, and distillation, which makes this process less applicable for an industrial scale synthesis. The object of the present invention is to provide a method for producing alkylphenol methacrylate, especially cardanol methacrylate, on an industrial scale, at high purity and at high yield.

[0009] These requirements could be solved by a reaction of alkylphenol (eductl) and methacrylic acid anhydride (MAAH, educt2) in the presence of a catalyst, followed by purification steps.

[0010] According to the inventive process for synthesizing alkylphenol methacrylate as product, having the general formula I wherein the functional group R1 is a linear C9-C17 alkyl chain having no, mono, di or tri unsaturation in the alkyl chain; by providing alkylphenol (educt 1), having the general formula II (II), wherein the functional group R2 is a linear C9-C17 alkyl chain having no, mono, di or tri unsaturation in the alkyl chain; and methacrylic acid anhydride (MAAH, educt 2) having the general formula III in the presence of at least one catalyst fed / charged to a reactor (220) comprising a motorised stirrer (222) at a temperature in the range of 70 °C to 120 °C for a stirring time of at least 2h for this product mixture (stirring step), wherein

[0011] - MAAH is charged with an excess of at least 1 .05;

[0012] - the catalyst is fed at a concentration of at least 0.2 mol%, wherein at least one of the following catalysts are provided: alkyl titanate,, magnesium chloride, lithium methanolate, mixture of lithium hydroxide and calcium oxide, mixture of lithium chloride and calcium oxide, calcium oxide, or sulfuric acid;

[0013] - the stirring step is followed by

[0014] - a distillation step by using a distillation device, wherein MAAH and the side product methacrylic acid is separated from the product mixture, wherein the catalysator is part of the product mixture.

[0015] “Separation step” means any useful separation process in using any useful separation device, such as but not limited to, e.g., a filter device (unit), centrifuge, decanter, sedimentation device and / or a combination thereof.

[0016] As an optional step, the substances are heated up to a temperature in the range of 70 °C to 120 °C, prior to feeding to the first reactor.

[0017] The “stirring time” is calculated from the end of the complete feeding of the alkylphenol (general formula II), MAAH (general formula III), and the catalyst to the reactor. The term “wt.-%” as used herein is meant as weight percentage and the term “mol%” as used herein means the percentage in molarity.

[0018] According to a preferred version of the process, alkylphenol methacrylate having the general formula I is cardanol methacrylate, wherein the functional group R1 is a linear C15 alkyl chain, and eductl alkylphenol having the general formula II is cardanol, wherein the functional group R2 is a linear C15 alkyl chain. According to a most preferred version of the process the functional group R1 is identical to the functional group R2

[0019] The distillation step by using a distillation device, wherein MAAH and the side product methacrylic acid is separated from the product mixture, wherein the catalysator is part of the product mixture is conducted at a vacuum as high as possible. As used herein, a “high vacuum” means “very low pressure”. Thus, the vacuum is preferably equal to 10 mbar or under 10 mbar, preferably equal to or under 2.5 mbar, most preferably equal to or under 0.1 mbar. Ideally, the vacuum is equal to or under 0.5 mbar. Usually, a vacuum of 0.45 - 0.25 is the highest vacuum limit in an industrial scale product line. According to a preferable embodiment of the process, the alkylphenol methacrylate as product have the general formula I, wherein alkylphenol methacrylate is a mixture defined by a first amount of alkylphenol methacrylate molecules according to the general formula I having a first functional group R1 .1 with a first chain length, and at least one further amount of alkylphenol methacrylate molecules according to the general formula I having another chain length R1 .2, wherein R1 .1 is different from R1 .2.

[0020] Thus, alkylphenol methacrylate as product mixture might contain functional groups R1 with different chain lengths.

[0021] Analogously, a preferable embodiment of the process can comprise the use of alkylphenol as educt having the general formula II, wherein alkylphenol is a mixture defined by a first amount of alkylphenol molecules according to the general formula II having a first functional group R2.1 with a first chain length, and at least one further amount of alkylphenol molecules according the general formula II having another chain length R2.2, wherein R2.1 is different from R2.2. Thus, alkylphenol as educt mixture might contain functional groups R2 with different chain lengths, meaning different numbers of carbon atoms.

[0022] In an advantageous embodiment of the process, a precipitating step of the catalyst is provided, wherein the catalyst is converted into a basic catalyst complex and alkylphenol methacrylate remains liquid; and the precipitation step is followed by

[0023] - a separation step, wherein the precipitated catalyst is separated from alkylphenol methacrylate. Thus, by implementing this enhanced embodiment of the process, an increased purity of alkylphenol methacrylate as product can be obtained.

[0024] According to a preferred embodiment, a preparation step is conducted, wherein at least partially before and / or during the stirring step at least alkylphenol (eductl), MAAH (educt2) and / or the catalyst are charged to the reactor.

[0025] According to another preferred embodiment of the process, the concentration of the at least one catalyst is as follows: a) alkyl titanate of 0.2 to 1 .2 mol%, preferable 0.3 to 0.8 mol%, most preferably 0.3 to 0.5 mol% wherein preferably the alkyl titanate is isopropylortho titanate; b) magnesium chloride of 0.1 to 1.0 mol%, preferably 0.15 to 0.5 mol%, most preferably 0.2 to 0.3 mol%; c) lithium methanolate of 2.0 to 10.0 mol%, preferably 3.0 to 7.5 mol%, most preferably 4.0 to 6.0 mol%; d) mixture of lithium hydroxide and calcium oxide each of 0.5 to 5.0 mol%, preferably 1 .0 to 2.5 mol%, most preferably 1 .5 to 2.0 mol%; e) mixture of lithium chloride and calcium oxide each of 0.5 to 5.0 mol%, preferably 1 .0 to 2.5 mol%, most preferably 1 .5 to 2.0 mol%; f) calcium oxide of 1 .5 to 10.0 mol%, preferably 2.0 to 6.0 mol%, most preferably 3.0 to 5.0 mol%; or g) sulfuric acid of 0.1 to 5.0 mol%, preferably 0.5 to 2.5 mol%, most preferably 0.75 to 1 .5 mol%.

[0026] The catalyst is preferably dissolved and / or diluted in a liquid phase, such as, but not limited to, e.g., water and / or an organic fluid, e.g., an alcohol, preferably a non-aromatic alcohol.

[0027] In an advantageous embodiment of the process, a precipitating step of the catalyst is provided, wherein the catalyst is an isopropylortho titanate and is converted into basic titanate complexes and alkylphenol methacrylate remains liquid; and the precipitation step is followed by

[0028] - a separation step, wherein the precipitated titanate complexes are separated from alkylphenol methacrylate, preferably form cardanol methacrylate. Thus, by implementing this enhanced embodiment of the process, an increased purity of alkylphenol methacrylate as product can be obtained. There are mainly two alternative separation steps possible: i) Isopropylortho titanate feed is in such a low concentration in the product mixture, e.g., equal to or under 1 .0 mol%, and / or as mentioned above, so that the titanate complexes remain dissolved in the product mixture; ii) Isopropylortho titanate feed is in such a high concentration in the product mixture, e.g. above 1 .0 mol%, so that the titanate complexes are precipitated into solvent salt and can be filtered off from the product mixture.

[0029] Without intending being bound to one single interpretation or teaching, the titanate complexes of the first alternative separation step are dissolved in the product mixture due to the presence of low concentrations of methacrylic acids as side products. The concentration of methacrylic acid in the product mixture downstream of the first reactor and first distillation device can be in the range of up to 1 .0 wt.-%, preferably up to 0.5 wt.-%, most preferably up to 0.4 wt.-%.

[0030] According to another preferred embodiment of the process, the excess of the MAAH is 1 .05 to 2.0, preferably 1 .1 to 1 .9, more preferably 1 .15 to 1 .8, most preferably 1 .2 to 1 .5.

[0031] In case of higher excess rates, the loss of MAAH in the outlet of distillation device during the distillation step is too high, which is a commercial disadvantage. Beside this, the formation of side products is increased parallel to the increased excess rate, which leads to a loss in yield.

[0032] According to another preferred embodiment of the process, the temperature range is 70 °C to 120 °C, preferably 85 °C to 105 °C, most preferably 90 °C to 100 °C. The temperature range is meant as being provided inside the stirring reactor, and / or the temperature of the stirred product mixture during the stirring step. The temperature range is preferably given for at least 80% of the stirring time, most preferably for at least 90%. According to a preferred embodiment, and with the option to decrease the stirring time, the feed streams of alkylphenol (eductl) and / or MAAH are heated up, analogously to the above-mentioned temperature ranges prior to entering the reactor.

[0033] According to another preferred embodiment of the process, the stirring time of the stirring step is 3.0 h to 10.0 h, preferably 4.0 to 10.0 h, most preferably 5.0 to 10.0 h.

[0034] According to another preferred version of this process embodiment, no feed stream leads from the reactor to the distillation device during the stirring step. With other words, preferably, there is no alteration in the mass of the product mixture inside the reactor during the stirring step.

[0035] According to another preferred embodiment of the process, the product mixture generated during the stirring step is purified in the distillation step with a thin film evaporator as distillation device by separating at least remaining MAAH and one side product as steam phase.

[0036] One of the side products might be methacrylic acid, contained in the steam phase.

[0037] The MAAH and methacrylic acid containing steam phase is released from the distillation device and preferably liquified in a condensation step. According to a preferred embodiment of the process, during the condensation step, the temperature is decreased, preferably down to 5 °C to 50 °C, most preferably down to 5 °C to 20 °C. By an advantageous further improved embodiment of the condensation step, pressure is at least temporarily increased up to 10 bar, preferably up to 5 bar, and most preferably up to 3 bar.

[0038] According to another preferred version of this process embodiment, the distillation step with the thin layer evaporator (230) is done at a temperature of 130 °C to 160 °C, preferably from 140 C to 150 °C, with a feed volume flow of at least 250 l / h, preferably from 300 l / h to 400 l / h.

[0039] The thin layer evaporation and the technical devices are well known. Preferably, the thin film evaporation is done under vacuum, wherein the vacuum is preferably in the range of 0,95 bar to 0,05 bar, most preferably in the range from 0,85 bar to 0,05 bar.

[0040] Process according any of the preceding claims, wherein the precipitating step of the catalyst includes i) adding sulfuric acid with a concentration of at least 30 wt.-% to the product mixture, preferably at least 40 wt.-%, most preferably at least 50 wt.-%, and wherein the step of adding sulfuric acid (acidifying step) is followed by ii) adding an alkaline substance, such as, but not limited to sodium carbonate (neutralisation step). According to another preferred embodiment of the process, the separation step separating the precipitated catalyst from cardanol methacrylate is a filtering step with a filter device, preferably a fleece filter or non-woven filter.

[0041] According to another preferred embodiment of the process, the process is a batch process.

[0042] One batch cycle is mainly defined by the filling of the main stirring reactor. However, subsequent process steps of an earlier batch cycle, such as but not limited to, e.g., precipitation step or separation step might still be running, while a later (new) batch cycle is started in refilling the main stirring reactor and / or starting the later stirring step.

[0043] Alkylphenol methacrylate, especially cardanol methacrylate, is used in large scale as comonomer in emulsion polymerization for acrylic binders providing functionality for post-crosslinking by oxygen. An alternative use is as oxygen scavenger to prevent oxygen inhibition in gel coat and other applications.

[0044] Herein after, embodiments of a preferable production line are shown as an example in two figures, showing embodiments of a production line and the related process in question. It is shown in

[0045] Figure 1 a first embodiment of the process unit and the related process and Figure 2 a second embodiment of the process unit and the related process.

[0046] The production line 100 as shown in figure 1 , comprises a storage unit 200, a stirring reactor 220, a distillation device 230, a condensing device 240, a filter device 260 and a control unit 300.

[0047] The storage unit 200 comprises at least one storage tank 202 for alkylphenol (eductl), herein cardanol (eductl), one storage tank 204 for MAAH (educt2) and one storage tank for the catalyst. Each storage tank 202, 204, 206 is connected to the reactor 220 by a respective feed line 102, 104, 106.

[0048] As an alternative process line 100 - not shown - at least one of the furnished educts cardanol, MAAH and / or the catalyst is charged via a feed line from a process unit upstream to the shown process line 100.

[0049] It is clear to a person skilled in the art, that multiple devices and technical details are known and needed to complete such a production line 100, such as but not limited to, e.g. pumps, valves, sensors, actors, mounting devices. Thus, such missing equipment is selected by a skilled person due to the respective need. Beside this, other details are simplified for better understanding. E.g., even though multiple feed lines are shown leading to the reactor 220, these need not be arranged like that. These feed lines might be connected to, e.g., one central feed line being in connection with the reactor 220. Analogously, further substances are known to achieve a stable process and / or product quality, such as, but not limited to stabilizers, inhibitors. These further substances might be added to the process as needed.

[0050] The reactor 220 is a stirred reactor having at least one motorized and controllable stirrer 222. The reactor 220 further comprises a heating device and / or is connected to a heating device, which is according to the shown embodiment of figure 1 a heating jacket 224 having a heating fluid feed and a heating fluid outlet symbolized by arrows with no reference numbers. The heating is done preferably by steam or a heating oil. The stirrer motor is symbolized by an M in a circle.

[0051] Downstream to the reactor 220, the distillation device 230 is located formed as a thin film evaporator, connected by line 110. By line 110, product mixture from the outlet is led from the reactor 220 into the distillation device 230. The thin film evaporator (distillation device 230) having at least one central wiper plate 232 which is motorized and controllable. The distillation device 230 comprises a first outlet at the bottom. From this first outlet bottom, line 112 leads to the filter device 260, and a second outlet at the upper part or head part is in connection with a top line 114 leading to a condensing device 240 located downstream to the distillation device 230.

[0052] The first distillation device 230 further comprises a heating device and / or is connected to a heating device (not shown), which is according to the shown embodiment of figure 1 an internal heating channel 234 having a heating fluid feed and a heating fluid outlet symbolized by arrows with no reference numbers.

[0053] By the bottom line 112, the product enriched first mixture is released from the distillation device 230, wherein the first mixture comprises the catalyst.

[0054] By the top line 114, a second mixture, preferably as a steam phase, containing remaining MAAH and side products, such as but not limited to methacrylic acid, is led to the condensing device 240, condensed therein and released via line 124 from the product line 100, preferably passed into, e.g., a storage tank (not shown).

[0055] The production line 100 comprises at least one control unit 300 being connected to at least one of the devices via data and / or power lines 302, symbolized by dashed lines. The control unit 300 comprises at least one central processor unit (CPU) and might be one central control unit and / or comprises decentralized subunits, wherein each having, e.g., local microprocessor (MPU).

[0056] The filter device 260 is a beneficial option and serves primarily to extract foreign parts from the product mixture. According to the example shown in figure 1 , catalyst remains as permeate fluid in the product mixture, leaving the production line 100 via line 120. This embodiment of a production line 100 as shown in figure 1 is preferably beneficial for the use of a type of catalyst that cannot be solidified by precipitation and / or having such low concentration, so that the catalyst salt would remain dissolved in the product mixture even after a precipitation reaction.

[0057] Figure 2 shows a process unit and a process with an additional section for purifying the product mixture. In contrary to the example as shown in figure 1 , a second stirred reactor 250 is connected by the bottom line 112 downstream to the (first) distillation device 230. By line 126, an outlet of said second stirred reactor 250 is connected to a sedimentation device 270 for liquid phase separation by mass density, connected downstream with a filter device 260. Within the stirred reactor 250, the precipitation of the catalyst is conducted, by adding sulfuric acid in a first step as explained together with the examples, followed by a neutralization step in adding an adequate amount of sodium carbonate to the product mixture. Therefore, the reactor 250 is connected to an acid feed line 116 and a caustic feed line 118, whereby advantageous pH-meter, mass flow meters, and other sensors or control devices are not shown. The (feed) line 126 connects the reactor 250 and the downstream sedimentation device 270. In the upper liquid phase present in the sedimentation device 270, the cardanol methacrylate rich product phase is derived and led to the filter device 260 through outlet line 128. The lower liquid phase in the sedimentation device 270, being the catalyst rich phase, is separated and released via outlet line 130. The total filling level of the sedimentation device 270 is indicated by a horizontal full line and reference number 272, and the theoretical parting line between both liquid phases is indicated by a horizontal dashed line 271 .

[0058] Analogously to the example of figure 1 , downstream to the reactor 250 a filter device 260 is located, to separate mainly foreign particles from the product releasable via outlet line 122. Product cardanol methacrylate permeates the filter device 260 and is released via line 120 from the production line 100.

[0059] This embodiment of a production line 100 as shown in figure 1 is preferably beneficial for the use of a type of catalyst having such low concentration, so that the catalyst salt would remain dissolved in the product mixture even after a precipitation reaction, but an ultrahigh purity and product quality shall be achieved.

[0060] Example

[0061] For the examples, a production line 100 as shown in figure 1 was used.

[0062] The synthesis of cardanol methacrylate from the eductl cardanol and MAAH (educt2) was conducted in reactor 220. The stirring time was 5 hours at a temperature inside the 4 m3reactor of 90 °C. MAAH was fed into the reactor 100 with a molar excess of 1 .2 over cardanol molarity in the presence of a catalyst as stated in Table 1 . The total volume of the product mixture inside reactor during the stirring step was about ~ 1250 liter. Therein, cardanol methacrylate having the formula: wherein said formula is defined as alkylphenol methacrylate having the general formula I comprises a functional group R1 having a chain length of C15.

[0063] The cardanol provided having the formula: wherein said formula is defined as alkylphenol having the general formula II comprises a functional group R2 having a chain length of C15.

[0064] The product mixture was transferred via line 110 into the thin film evaporator (distillation device 230) and is then purified to separate the methacrylic acid and remaining MAAH through top line 114 from the product mixture, exiting the distillation device through bottom line 112.

[0065] In an ultimate step in case of an isopropylortho titanate catalyst, this catalyst is precipitated inside the stirring reactor 250 by adding 0.16 mol% sulfuric acid. After neutralization with sodium carbonate to a neutral pH-value, catalyst as listed in Table 1 was precipitated, separated and cardanol methacrylate (permeate) with a purity of > 80% is obtained in yields above 85%, collected from line 120. During the examples? the precipitated catalyst was not separated from the product mixture by filtration due to its low concentration in the mixture (see Table 1). As described above, it was found that due to the low concentration of this transition metal catalyst, the respective salt derived by precipitation of alkyl titanate remains dissolved in the product mixture and could not be separated by filtering.

[0066] The comparable example was synthesized according to the process description in the paper “Design, preparation and properties of novel renewable UV-curable copolymers based on cardanol and dimer fatty acids” (Progress in organic Coating, Vol 77 (2014), p. 388-394.

[0067] Thus, cardanol was reacted with MAAH in dioxan using potassium carbonate as catalyst in a stirred reactor for 3 h. This stirring step was done under nitrogen gas protection to prevent inhibition by free oxygen radicals. The product mixture was vacuum filtered, and the solvent was evaporated. The residual liquid mixture was then washed with weak alkali and water by using two extraction steps. Finally, the residual water was removed by a second vacuum distillation.

[0068] The product purity was measured by Gas Chromatography using an Agilent 7890A device, the catalyst concentration was triggered by digestion method linked to emission spectroscopy using a CEM MARS6 and Thermo Fisher iCAP 7400 Duo device, the Iodine value was derived from titration with a Metrohm Titrino plus 848 device. To measure the water content in the product, a Metrohm Titrando 851 was used, and finally the acid content in the product was identified by titration method using a Metrohm Titrando 888.

[0069] Results of the inventive process (E1 - E4), as well as the comparative example (E0), are listed below in Table 1 .

[0070] Table 1 : Experiments and Comparison

[0071] It was found besides isopropylortho titanate, magnesium chloride (MgCI2) is also applicable as catalyst and cardanol methacrylate is obtained in high purity of > 85% and yields > 90 %.

[0072] Unfortunately, during distillation by thin film evaporation, a thin deposit layer of MgCI2 precipitate on the inner surfaces of the thin film evaporator (distillation device 230) appears, which efforts extensive cleaning procedures. Thus, MgCI2 is less useful when a thin film evaporator is used as separation equipment, i.e., distillation device.

[0073] Overall, it was found that a process according to the inventive embodiment has comparable product purity and a yield of cardanol methacrylate, which is at least ~1 .4 higher than the yield of the known process (Experiment E0) References

[0074] 100 production line

[0075] 102 feed line

[0076] 104 feed line

[0077] 106 feed line

[0078] 110 line

[0079] 112 bottom line (out)

[0080] 114 top line (out)

[0081] 116 feed line

[0082] 118 feed line

[0083] 120 product line

[0084] 122 line (out)

[0085] 124 line (out)

[0086] 200 storage unit

[0087] 202 storage tank (eductl)

[0088] 204 storage tank (MAAH, educt2)

[0089] 206 storage tank (catalyst)

[0090] 220 reactor (stirred, main)

[0091] 222 stirrer (motorised)

[0092] 224 heating jacket

[0093] 230 distillation device (main)

[0094] 232 Wiper plate

[0095] 234 heating channel, internal

[0096] 240 condensing device

[0097] 250 reactor (stirred, sub)

[0098] 260 filter device, filter unit

[0099] 270 sedimentation device

[0100] 271 filling level

[0101] 272 parting line

[0102] 300 control unit

[0103] 302 data line

Claims

Claims1 . Process for synthesizing alkylphenol methacrylate as product, having the general formula I(I), wherein the functional group R1 is a linear C9-C17 alkyl chain having no, mono, di or tri unsaturation in the alkyl chain; by providing alkylphenol, having the general formula II(II), wherein the functional group R2 is a linear C9-C17 alkyl chain having no, mono, di or tri unsaturation in the alkyl chain; and methacrylic acid anhydride (MAAH) having the general formula IIIin the presence of at least one catalyst provided to reactor (220) comprising a motorised stirrer (222) at a temperature in the range of 70 °C to 120 °C for a stirring time of at least 2 h for this product mixture (stirring step), wherein- MAAH is provided with an excess of at least 1 .05;- the catalyst is provided at a concentration of at least 0.2 mol%, wherein at least one of the following catalysts are provided: alkyl titanate, magnesium chloride, lithium methanolate, mixture of lithium hydroxide andcalcium oxide, mixture of lithium chloride and calcium oxide, calcium oxide, or sulfuric acid;- the stirring step is followed by- a distillation step by using a distillation device (230), wherein MAAH and the side product methacrylic acid is separated from the product mixture, wherein the catalyst is part of the product mixture,- a precipitating step of the catalyst, wherein the catalyst is solidified and cardanol methacrylate is liquified, and- a separation step, wherein the precipitated catalyst is separated from alkylphenol methacrylate.

2. Process according to claim 1 , wherein the alkylphenol methacrylate having the general formula I (I) is cardanol methacrylate, wherein the functional group R1 is a linear C15 alkyl chain.

3. Process according to claim 1 or 2, wherein the concentration of the at least one catalyst is as follows: a. alkyl titanate of 0.2 to 1 .2 mol%, preferably 0.3 to 0.8 mol%, most preferably 0.3 to 0.5 mol%, preferably isopropylortho titanate; b. magnesium chloride of 0.1 to 1.0 mol%, preferably 0.15 to 0.5 mol%, most preferably 0.2 to 0.3 mol%; c. lithium methanolate of 2.0 to 10.0 mol%, preferably 3.0 to 7.5 mol%, most preferably 4.0 to 6.0 mol%; d. mixture of lithium hydroxide and calcium oxide each of 0.5 to 5.0 mol%, preferably 1.0 to 2.5 mol%, most preferably 1 .5 to 2.0 mol%; e. mixture of lithium chloride and calcium oxide each of 0.5 to 5.0 mol%, preferably 1 .0 to 2.5 mol%, most preferably 1 .5 to 2.0 mol%; f. calcium oxide of 1 .5 to 10.0 mol%, preferably 2.0 to 6.0 mol%, most preferably 3.0 to 5.0 mol%; or g. sulfuric acid of 0.1 to 5.0 mol%, preferably 0.5 to 2.5 mol%, most preferably 0.75 to 1.5 mol%.

4. Process according to any of the preceding claims, wherein the excess of the MAAH is 1 .05 to 2, preferably 1 .1 to 1 .9, more preferably 1 .15 to 1 .8, most preferably 1 .2 to 1 .5.

5. Process according to any of the preceding claims, wherein the temperature range is 70 °C to 120 °C, preferably 85 °C to 105 °C, most preferably 90 °C to 100 °C.

6. Process according to any of the preceding claims, wherein the stirring time of the stirring step is 3h to 10h, preferably 4 to 10h, most preferably 5 to 10h.

7. Process according to claim 6, wherein no feed stream leads from the reactor (220) to the distillation device (230) during the stirring step.

8. Process according to any of the preceding claims, wherein at least partially before and / or during the stirring step at least alkylphenol (eductl), MAAH (educt2) and / or the catalyst are charged to the reactor (220).

9. Process according to any of the preceding claims, wherein product mixture generated during the stirring step is purified in the distillation step with a thin film evaporator as distillation device (230) by separating at least remaining MAAH and at least one side product as steam phase.

10. Process according to claim 9, wherein the distillation step with the thin film evaporator (230) is done at a temperature of 130 °C to 160 °C, preferably from 140 °C to 150 °C, with a feed volume flow of at least 250 l / h, preferably from 300 l / h to 400 l / h.

11. Process according any of the preceding claims, wherein the precipitating step of the catalyst includes i) adding sulfuric acid with a concentration of at least 30 wt.-% to the product mixture, preferably at least 40 wt.-%, most preferably at least 50 wt.-%, and wherein the step of adding sulfuric acid (acidifying step) is followed by ii) adding an alkaline substance, such as, but not limited to sodium carbonate (neutralisation step).

12. Process according to any of the preceding claims, wherein the separation step separating the precipitated catalyst from cardanol methacrylate is filtering with a filter device (260).

13. Process according to any of the preceding claims, wherein the process is a batch process.

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