Method for obtaining biogenic N-vinylformamide

Abstract

The present invention relates to a method for obtaining N-vinylformamide, comprising the reaction between acetaldehyde and formamide, one of which, preferably both, is at least partially renewable and non-fossil. The present invention also relates to a bio-sourced N-vinylformamide monomer, a bio-sourced polymer incorporating at least said monomer, and the use of said polymer in various technical fields.

Description

Technical Field

[0001] The present invention relates to a process for obtaining biogenic N-vinylformamide, comprising the reaction between acetaldehyde and formamide, one of which, preferably both, are at least partially renewable and non-fossil. The present invention relates to biogenic N-vinylformamide monomers, and to biogenic polymers obtained from at least one biogenic N-vinylformamide monomer according to the present invention. Finally, the present invention relates to the use of the biogenic polymers according to the present invention in various technical fields. Background Art

[0002] Ethylenically unsaturated monomers, such as N-vinylformamide, are widely used in the manufacture of water-soluble polymers.

[0003] N-vinylformamide (NVF) is obtained according to the reaction scheme below.

[0004]

[0005] There are many variants depending on the HX protecting agent used. NVF is usually synthesized by the so-called "alkoxy" method, in which the protecting agent is an alcohol, more preferably methanol. The synthesis is carried out in two steps, first obtaining hydroxyethylformamide from acetaldehyde and formamide. Hydroxyethylformamide is then converted into methoxyethylformamide by reaction with methanol and a catalyst. Methoxyethylformamide is then pyrolyzed at high temperatures to obtain N-vinylformamide.

[0006] Acetaldehyde is a raw material obtained from the oxidation of ethylene as described in the Wacker process. Ethylene is a fossil-based olefin currently produced by steam cracking of naphtha, which itself comes from crude oil refining. More recently, with the advent of shale gas production, various ethane dehydrogenation processes have been described for the production of ethylene.

[0007] Fossil-based ethylene contains various impurities that either remain or are converted by the Wacker process. In addition, acetaldehyde tends to oxidize to acetic acid due to the presence of oxygen in the Wacker process.

[0008] Formamide is obtained by reacting formic acid with ammonia. Formic acid is fossil-based and is obtained by the reaction between ethane and oxygen, as described in document US 3,056,833.

[0009] Document US 4,567,300 describes the formation of hydroxyethylformamide in the presence of acetaldehyde and formamide. In order to counteract the acidity present in the fossil-based acetaldehyde, the addition of a base, in this case potassium carbonate, is described in order to achieve a good conversion of the reactants and obtain high-quality hydroxyethylformamide.

[0010] Other variants for obtaining N-vinylformamide have been described, such as the so-called "hydrocyanic acid" process, in particular in document US 3,822,306. In this case, the protective agent is hydrocyanic acid which reacts with acetaldehyde. The yield is limited to only 75% and involves hydrocyanic acid, which is a highly toxic compound. N-vinylformamide can also be obtained according to another variant known as "bis ethylene formamide", described, for example, in document US 4,906,777.

[0011] In all cases, the three carbons of N-vinylformamide are derived from acetaldehyde and formamide.

[0012] In order to counteract the lower quality of N-vinylformamide resulting from the use of raw materials having a high proportion of impurities, strategies for purifying N-vinylformamide have been described.

[0013] Document US 4,818,505 describes a fractionation method on a column under very high vacuum (0.5 mbar or 1 bar = 10 5 The process of the present invention is carried out at 200 °C (100 °F) in order to separate the unreacted formamide from the previous step and N-vinylformamide. The mixture to be separated must be heated to high temperatures. N-vinylformamide is a reactive monomer by nature and part of the mixture to be separated will polymerize, which leads to yield losses, polymers that must be destroyed and to yield losses in the production unit (caused by the distillation column being stopped for cleaning).

[0014] Document WO 2018 / 108608 A1 discloses a polymer comprising: (a) 9.49 to 98 mol% of a compound of the formula [CH2-CR 1 ((C=O)-NR 2 -A-SO2-O - Q + )] units, wherein at least 10 wt% of these units of formula (1) contain 28 wt% to 100 wt% of biogenic carbon content; (b) 0.01 mol% to 5 mol% of crosslinking or branching units; (c) 0.01 mol% to 88.52 mol% of repeating neutral structural units; (d) 1.98 mol% to 20 mol% of repeating anionic structural units. Document WO 2018 / 108608 A1 does not teach polymers containing biogenic N-vinylformamide.

[0015] Document US2018 / 057445 relates to a method for producing N-vinylcarboxylic acid amides (e.g., N-vinylformamide and its intermediates). It does not describe the use of biogenic compounds.

[0016] The problem proposed to be solved by the present invention is to propose a new and improved polymer obtained from bio-sourced N-vinylformamide monomers. Summary of the invention

[0017] Surprisingly, the Applicant has found that the use of acetaldehyde and formamide, one of which, preferably both, are at least partially renewable and non-fossil, and preferably fully renewable, in a process for obtaining N-vinylformamide allows a significant improvement in the quality of the monomers obtained, and thus in their polymerization and in the application properties of the polymers obtained.

[0018] The Applicant has discovered this improvement in particular in the process for obtaining N-vinylformamide by the "alkoxy" process, in particular when the alcohol used as protecting agent is methanol or isopropanol, preferably methanol.

[0019] Without seeking to be bound by any particular theory, applicants propose the possibility that differences in the nature of impurities between fossil-based acetaldehyde and renewable and non-fossil-based acetaldehyde and / or between fossil-based formamide and renewable and non-fossil-based formamide are responsible for these unexpected technical effects.

[0020] “A and / or B” should be understood to mean A, or B, or A and B according to the present invention.

[0021] First and foremost, the present invention relates to a process for obtaining N-vinylformamide, which comprises the reaction between acetaldehyde and formamide, one of which, preferably both, are at least partially renewable and non-fossil.

[0022] The present invention also relates to N-vinylformamide, wherein the biogenic carbon content of N-vinylformamide is 5 wt % to 100 wt % relative to the total carbon mass in the N-vinylformamide, and the biogenic carbon content is measured according to ASTM D6866-21 method B.

[0023] The invention also relates to a polymer obtained by polymerizing at least one N-vinylformamide monomer obtained by the process according to the invention or as described in the process, and to the use of said polymer in various technical fields.

[0024] Using the present invention, the environmental goals inherent in new technological innovations can be achieved. In the present case, the use of renewable raw materials (in this case acetaldehyde and / or formamide) helps to significantly optimize the conversion process and the quality of the resulting monomers.

[0025] Applicants have discovered that the biogenic nature of formamide enables better conversion to N-vinylformamide and produces fewer impurities compared to fossil formamide.

[0026] Applicants have also found that the conversion percentage of formamide is greater when the acetaldehyde is at least partly of renewable and non-fossil origin compared to the fossil compound.

[0027] The Applicant has also found that the use of formamide of partly or entirely renewable and non-fossil origin and of acetaldehyde of partly or entirely renewable and non-fossil origin improves the process for obtaining N-vinylformamide compared to fossil compounds.

[0028] Applicants have also discovered that polymers obtained from partially or fully biogenic monomers of the invention are more biodegradable than polymers obtained from fossil monomers.

[0029] The applicant has also found that, in addition to better drainage properties, the polymers of the invention exhibit dry strength properties that are at least comparable to or even better than polymers obtained from fossil monomers. DETAILED DESCRIPTION

[0030] In the context of the present invention, the term "renewable and non-fossil" is used to indicate that the source of a chemical compound is derived from biomass or synthesis gas (syngas), i.e. produced by one or more chemical transformations of one or more natural and non-fossil raw materials. The term "biogenic" or "biogenic" may also be used to characterize a renewable and non-fossil source of a compound. Renewable and non-fossil sources of compounds include renewable and non-fossil raw materials from the circular economy that have previously been recycled one or more times in a biomass material recovery process, such as materials from polymer depolymerization or pyrolysis oil processing.

[0031] According to the invention, the "at least partly renewable and non-fossil" quality of a compound means a biogenic carbon content of preferably 5% to 100% by weight relative to the total carbon weight of said compound.

[0032] In the context of the present invention, ASTM D6866-21 Standard Method B is used to characterize the biogenic nature of chemical compounds and to determine the biogenic carbon content of said compounds. This value is expressed as the weight percentage (wt %) of biogenic carbon relative to the total carbon weight in said compound.

[0033] ASTM D6866-21 is a test method that teaches how to experimentally measure the biogenic carbon content of solid, liquid, and gaseous samples through radiocarbon analysis.

[0034] The standard primarily uses accelerator mass spectrometry (AMS) technology. This technique is used to naturally measure radionuclides present in a sample, where atoms are ionized and then accelerated to high energies before being separated and individually counted in a Faraday cup. This high-energy separation is extremely effective in filtering out isobaric interferences, so AMS is able to accurately measure the abundance of carbon 14 relative to carbon 12 (14C / 12C) with an accuracy of 1.10 -15 .

[0035] ASTM D6866-21 Standard Method B uses AMS and IRMS (Isotope Ratio Mass Spectroscopy). This test method can directly distinguish between present-day carbon-based carbon atoms and fossil-based carbon atoms. The carbon-14 relative to carbon-12 or carbon-14 relative to carbon-13 content of the product is measured against a modern carbon-based reference material recognized by the radiocarbon dating community (e.g., NIST's Standard Reference Material (SRM) 4990C) (oxalic acid).

[0036] The sample preparation method is described in the standard and does not require any special comments as it is a commonly used procedure.

[0037] The analysis, interpretation and reporting are described below. AMS is used to measure the isotopic ratio of carbon 14 to carbon 12 content or carbon 14 to carbon 13 content. The isotopic ratio of carbon 14 to carbon 12 content or carbon 14 to carbon 13 content is determined relative to a standard traceable to the NIST SRM 4990C modern reference standard. The "modern fraction" (fM) represents the carbon 14 content in the product being tested relative to a modern standard. It is often referred to as the modern carbon percentage (pMC), which is equivalent to fM (e.g. fM 1=100pMC).

[0038] All pMC values ​​obtained from radiocarbon must be corrected for isotope fractionation using the given stable isotope. If possible, the correction should be made using carbon-14 measured directly using AMS relative to the carbon-13 value. If this is not possible, the correction should be made using delta13C (δ13C) measured using IRMS, CRDS (Cavity Ring Down Spectroscopy) or any other equivalent technique that can provide an accuracy within plus or minus 0.3 parts per thousand.

[0039] "Zero pMC" indicates the complete absence of measurable 14C above background signal in the material, thus indicating a fossil (e.g. petroleum-based) carbon source. A value of 100 pMC indicates a completely "modern" carbon source. pMC values ​​between 0 and 100 indicate the proportion of carbon from fossil sources relative to "modern" sources.

[0040] Due to the continuing but diminishing impact of atmospheric nuclear testing programmes injecting 14C into the atmosphere, pMC may be higher than 100%. pMC values ​​need to be adjusted by an atmospheric correction factor (REF) to obtain the true biogenic content of the sample.

[0041] The correction factor is based on the excess 14C activity in the atmosphere at the time of the test. Based on measurements of CO2 in air in a rural area of ​​the Netherlands (Ludgervaard, Groningen), the REF value for 2015 was determined to be 102 pMC. The first edition of the standard in 2004 (ASTM D6866-04) had a reference value of 107.5 pMC, while the later edition ASTM D6866-10 (2010) had a reference value of 105 pMC. These data points represent a decrease of 0.5 pMC per year. Therefore, on January 2 of each year, the values ​​in Table 1 below are used as the REF values ​​until 2019, reflecting the same decrease of 0.5 pMC per year. Based on continuous measurements in the Netherlands (Ludgervaard, Groningen) until 2019, the REF value (pMC) for 2020 and 2021 has been determined to be 100.0. References reporting 14C and 13C carbon isotope ratio data are provided below, Roessler, N., Valenta, R. J., and van Cauter, S., "Time-Resolved Liquid Scintillation Counting," in Liquid Scintillation Counting and Organic Scintillator, Ross, H., Noakes, J. E., and Spaulding, J. D., eds., Lewis Publishers, Chelsea, MI, 1991, pp. 501-511. Allison, C. E., Francy, R. J., and Meijer, H. A. J., "Reference and Comparison Materials for Stable Isotopes of Light Elements," International Atomic Energy Agency, Vienna, Austria, IAEATEC H. D.C.-825, 1995.

[0042] The percentage of biogenic carbon content is calculated by dividing pMC by REF and multiplying the result by 100. For example, [102(pMC) / 102(REF)] x 100 = 100% biogenic carbon. The results are expressed as the weight percent (wt %) of biogenic carbon relative to the total carbon weight in the compound.

[0043] [Table 1]

[0044] REF Year oeLh 2015 102,0 2016 101，5 2017 101，0 2018 100，5 2019 100，0 2020 100，0 2021 100，0

[0045] Table 1: Percent Modern Carbon (pMC) References

[0046] In the context of the present invention, the term "segregated" refers to a material flow that is distinct and distinguishable from other material flows in a value chain (e.g. in a product manufacturing process) and is therefore considered to belong to a group of materials with equivalent properties, so that the same origin of the material, or its manufacture according to the same standards or specifications, can be traced and guaranteed throughout the value chain.

[0047] For example, this might be the case where a chemist exclusively purchases 100% bio-derived acetaldehyde from a single supplier who guarantees that the delivered acetaldehyde is 100% bio-derived, and the chemist processes this 100% bio-derived acetaldehyde separately from other potential sources of acetaldehyde to produce a compound. If the produced compound is made only from said 100% bio-derived acetaldehyde, then the compound is 100% bio-derived.

[0048] In the context of the present invention, the term “non-segregated”, in contrast to the term “segregated”, is understood to mean a material flow that cannot be distinguished from other material flows in the value chain.

[0049] To better understand this concept of separation, it is useful to review some basics of the circular economy and its practical application in approaches, especially chemical transformations.

[0050] According to the French Environment and Energy Management Agency (ADEME), the circular economy can be defined as an economic system of trade and production that seeks to increase efficiency and reduce environmental impact in the use of resources at all stages of the product (goods and services) life cycle, while developing individual well-being. In other words, it is an economic system committed to efficiency and sustainability, minimizing waste by optimizing the value generated by resources. It relies heavily on various conservation and recycling applications to move away from the current more linear "take-make-dispose" approach.

[0051] In chemistry, it is the science of converting one substance into another, meaning the reuse of materials that have already been used to make a product. In theory, all chemicals can be separated and therefore recycled separately from other chemicals. The reality is more complicated, especially in industry, meaning that even after separation, the compound is often indistinguishable from the same compound from other sources, complicating the traceability of recycled materials.

[0052] For this reason, various traceability models have been developed taking into account this industrial reality, allowing users in the chemical industry to manage their material flows with full knowledge of the facts and for the end customer to understand and know in a simple way the origin of the materials used to produce an object or commodity.

[0053] These models are developed to build transparency and trust throughout the value chain. Ultimately, this allows the end user or customer to choose more sustainable solutions by understanding the proportion of desired ingredients (e.g. biogenic properties) in an object or commodity, without having to autonomously control every aspect of the process.

[0054] One such model is what we defined earlier as “separation.” Some known examples where this model is applied are glass and some metals, where the material flows can be tracked separately.

[0055] However, chemicals are often used in complex combinations and individual cycles are often difficult to implement, especially due to high costs and highly complex flow management, making the "separate" model not always applicable.

[0056] Therefore, when it is not possible to distinguish the material streams, other models are applied, which are grouped together under the term "non-separated" and require consideration of the proportion of a particular stream relative to other streams, etc., without physically separating the streams. An example is the Mass Balance Approach.

[0057] The mass balance approach involves accurately tracking the proportion of one category (e.g. “recycled”) in a production system relative to the whole, in order to ensure that the contents of that category are proportionately and appropriately distributed in the finished product, based on an auditable accounting ledger.

[0058] For example, a chemist buys 50% bio-derived acetaldehyde from a supplier who guarantees that 50% of the delivered acetaldehyde is of bio-derived origin according to a mass or weight balance method and 50% is not of bio-derived origin, and the chemist uses this 50% bio-derived acetaldehyde together with another stream of 0% bio-derived acetaldehyde, the two streams being unidentifiable at some point in the production process, for example due to mixing. If the produced compound is made of 50 wt% of 50% bio-derived guaranteed acetaldehyde and 50 wt% of 0% bio-derived acrylonitrile, the compound is 25% bio-derived.

[0059] For example, in order to guarantee claimed “biosourced” figures and to encourage the use of recycled raw materials in the production of new products, a globally shared set of standardized rules (ISCC+, ISO 14020) has been developed to reliably manage material flows.

[0060] In the context of the present invention, the term "recycled" is understood to mean a source of compounds derived from a process of recycling materials considered as waste, i.e. one or more transformations of at least one material generally considered as waste, using at least one recycling process.

[0061] The term "water-soluble polymer" is understood to mean a polymer which dissolves in water at 25°C with stirring at a concentration of 20 g.L -1 A polymer that produces a clear aqueous solution.

[0062] Method of the present invention

[0063] The present invention therefore relates to a process for obtaining N-vinylformamide comprising the reaction between acetaldehyde and formamide, one of which, preferably both, are at least partly renewable and non-fossil.

[0064] More particularly and preferably, the compounds used to obtain N-vinylformamide and containing the carbon atoms to be found in the N-vinylformamide molecule are partially or completely renewable and non-fossil. These compounds are acetaldehyde and formamide.

[0065] The biogenic carbon content of acetaldehyde is preferably 5 wt% to 100 wt% relative to the total carbon mass in the acetaldehyde, the biogenic carbon content being determined according to ASTM D6866-21 Method B.

[0066] The formamide preferably has a biogenic carbon content of 5 wt % to 100 wt % relative to the total carbon mass in the formamide, the biogenic carbon content being determined according to ASTM D6866-21 Method B.

[0067] Throughout the invention, the biogenic carbon content of a compound that is at least partly renewable and non-fossil is specified, or the biogenic carbon content of the compound is specified to be 5 wt% to 100 wt%, preferably 10 wt% to 100 wt%, preferably 15 wt% to 100 wt%, preferably 20 wt% to 100 wt%, preferably 25 wt% to 100 wt%, preferably 30 wt% to 100 wt%, preferably 35 wt% to 100 wt%, preferably 40 wt% to 100 wt%, preferably 45 wt% to 100 wt%, preferably 50 wt% to 100 wt%, relative to the total carbon weight in the compound. 100wt%, preferably 55wt% to 100wt%, preferably 60wt% to 100wt%, preferably 65wt% to 100wt%, preferably 70wt% to 100wt%, preferably 75wt% to 100wt%, preferably 80wt% to 100wt%, preferably 85wt% to 100wt%, preferably 90wt% to 100wt%, preferably from 95wt% to 100wt%, preferably 97wt% to 100wt%, preferably 99wt% to 100wt%, wherein the biogenic carbon content is determined according to ASTM D6866-21 Method B.

[0068] Preferably, the biogenic carbon content of acetaldehyde is from 50 wt% to 100 wt%, preferably 100 wt%, relative to the total carbon mass in the acetaldehyde, the biogenic carbon content being determined according to ASTM D6866-21 Method B.

[0069] Preferably, the biogenic carbon content of the formamide is 100 wt % relative to the total carbon mass in the formamide, and the biogenic carbon content is determined according to ASTM D6866-21 Method B.

[0070] Preferably, the acetaldehyde is fully renewable and non-fossil. Preferably, formamide is fully renewable and non-fossil. Preferably, acetaldehyde and formamide are fully renewable and non-fossil.

[0071] The acetaldehyde and / or formamide, preferably both, may be non-isolated, partially isolated or completely isolated.

[0072] When acetaldehyde and / or formamide is fully renewable and non-fossil, it may be:

[0073] a) a fully recycled source and

[0074] a) 1) or completely separated;

[0075] a) 2) or partially separated;

[0076] a) 3) or non-separable;

[0077] b) or a partially recycled source and

[0078] b) 1) or completely separated;

[0079] b) 2) or partially separated;

[0080] b) 3) or non-separable;

[0081] c) or a completely non-recycling source and

[0082] c) 1) or completely separated;

[0083] c) 2) or partially separated;

[0084] c) 3) or non-separated.

[0085] In these various embodiments, when acetaldehyde and / or formamide are partially separated, the weight ratio between the "separated" portion and the "non-separated" portion is preferably 99:1 to 10:90, preferably 99:1 to 30:70, or more preferably 99:1 to 50:50.

[0086] Among these different embodiments, three embodiments a), three embodiments b) and embodiment c)1) are preferred. Among these embodiments, embodiments a)1), a)2), b)1), b)2) and c)1) are more preferred. The two most preferred embodiments are a)1) and b)1).

[0087] Preferably, acetaldehyde and / or formamide, preferably both, are partially or completely isolated.

[0088] Preferably, acetaldehyde and / or formamide, preferably both, are partially separated or fully recycled.

[0089] The industrial reality is that it is not always possible to obtain industrial quantities of bio-sourced, fully recycled and / or separated or highly recycled and separated acetaldehyde and / or formamide. Therefore, the above preferences may be more difficult to achieve at present. From a practical point of view, embodiments a) 3), b) 3) and c) are currently easier and more large-scale implementation. With the rapid development of circular economy technology, there is no doubt that the preferred mode that has been applied will soon be applied on a large scale.

[0090] When acetaldehyde and / or formamide are partly renewable and non-fossil, a distinction is made between a renewable fraction (biogenic) and a non-biogenic fraction. Obviously, each of these fractions can be according to the same embodiments a), b) and c) described above.

[0091] As for the biogenic portion of the partially biogenic acetaldehyde and / or formamide, the same preferences apply to the completely biogenic compounds.

[0092] However, with respect to the non-biogenic part of the partially biogenic compound, it is more preferred for a circular economy approach to have as large a recycling component as possible. Therefore, in this case, embodiments a)1), a)2), b)1), b)2), in particular a)1) and b)1) are preferred.

[0093] Acetaldehyde is preferably obtained from ethanol derived at least partly, preferably entirely, from biomass, or from ethylene derived at least partly, preferably entirely, from biomass.

[0094] Formamide is preferably obtained from formic acid derived at least partly, preferably entirely from biomass, or from ethyl formate derived at least partly, preferably entirely from biomass, or from the recovery of CO 2 , which is considered to be a renewable and non-fossil source.

[0095] Regarding the reaction of acetaldehyde with formamide to form N-vinylformamide, the skilled person can refer to the prior art. Preferably, the method for obtaining N-vinylformamide is by the "alkoxy" method, especially when the alcohol used as the protecting agent is methanol.

[0096] In the first step, acetaldehyde is contacted with formamide in the presence of a solvent and a base. Preferably, the reaction solvent is toluene and the base is potassium bicarbonate. The synthesis reactor is filled with a mixture of toluene and acetaldehyde.

[0097] Potassium bicarbonate is also mixed with formamide, and the mixture is then added continuously to the toluene and acetaldehyde mixture. This order of addition is preferred. In another embodiment, the formamide and potassium carbonate mixture are added sequentially to the toluene and acetaldehyde mixture. The reaction time is generally 0.5 hour to 10 hours, preferably 1 to 7 hours.

[0098] The molar ratio between acetaldehyde and formamide is usually 5: 1 to 1: 5, preferably 2: 1 to 1: 2. The reaction temperature is usually 0°C to 40°C, preferably 15°C to 30°C.

[0099] Hydroxyethylformamide crystallizes and precipitates in the reaction medium. In order to control the crystallization, the mixture of toluene and acetaldehyde is preferably seeded with hydroxyethylformamide crystals before the addition of the mixture of formamide and potassium bicarbonate.

[0100] At the end of the first step, the hydroxyethylformamide crystals are separated from the solvent by a filtration step. In a non-limiting manner, the filtration device can be a Nutsche filter, a filter press, a vertical or horizontal centrifuge, a rotary filter under vacuum or pressure, or simply a filter in the reactor if the reactor is equipped with a grid with a suitable mesh size at the drain to retain the hydroxyethylformamide crystals.

[0101] In the second step, methanol is added to the hydroxyethylformamide crystals. In this step, methanol acts as both a solvent and a reagent. The molar ratio between methanol and hydroxyethylformamide is generally 20:1 to 1:2, preferably 5:1 to 1:1.

[0102] The etherification reaction is carried out by an acid source, preferably a Bronsted acid ( Any organic or inorganic acid source may be suitable, but sulfuric acid is preferably selected.

[0103] The sulfuric acid is used both to neutralize the residual potassium bicarbonate used in the first step and as a catalyst for the reaction.

[0104] The reaction temperature is usually 5 to 80° C., more preferably 10 to 40° C. The reaction time between hydroxyethylformamide and methanol is 0.5 to 10 hours, more preferably 1 to 8 hours. The reaction product is methoxyethylformamide in liquid form.

[0105] The methoxyethylformamide is then purified to remove excess methanol and toluene. Preferably, the purification is carried out by at least one vacuum distillation column.

[0106] In the third and final step, the methoxyethylformamide thus obtained is subjected to a thermal decomposition reaction in the gas phase. The methoxyethylformamide is first heated to evaporate it. The methoxyethylformamide vapor is then introduced into the tubes of a pyrolyzer for thermal decomposition. The tubes are generally heated to a temperature of 200° C. to 600° C., preferably 250° C. to 550° C.

[0107] According to one embodiment, the process obtains N-vinylformamide by an alkoxylation process, using methanol as a protective agent, and the process preferably comprises thermal decomposition of N-vinylformamide at a temperature of 200° C. to 600° C. and at atmospheric pressure or under partial vacuum.

[0108] The pyrolyser may be operated at atmospheric pressure or under partial vacuum, preferably under partial vacuum, more preferably at a pressure of less than 100 mbar absolute.

[0109] The N-vinylformamide gas thus formed is usually cooled by a condenser or by a gas scrubber supplied with precooled liquid N-vinylformamide. The liquid thus obtained is a mixture of N-vinylformamide and methanol. An optional additional step is the evaporation of the methanol, for example in a falling film evaporator, flash evaporator, rotary evaporator or distillation column.

[0110] Monomers of the present invention

[0111] The present invention also relates to a biogenic N-vinylformamide having a biogenic carbon content of 5 wt% to 100 wt% relative to the total carbon mass in the N-vinylformamide, the biogenic carbon content being determined according to ASTM D6866-21 Method B. The same embodiments and preferences as in the "Methods" section apply to this section describing the monomers.

[0112] The present invention also relates to biogenic N-vinylformamide obtained by the reaction between acetaldehyde and formamide, wherein the acetaldehyde and / or the formamide, preferably both, have a biogenic carbon content of 5 wt% to 100 wt%, based on the total mass of carbon in the acetaldehyde and / or the formamide, wherein the biogenic carbon content is determined according to ASTM D6866-21 method B.

[0113] Preferably, acetaldehyde is fully renewable and non-fossil. Preferably, formamide is fully renewable and non-fossil. Preferably, acetaldehyde and formamide are fully renewable and non-fossil.

[0114] Throughout the invention, "biogenic N-vinylformamide" is understood to mean N-vinylformamide which originates at least partially, preferably completely, from biomass, i.e. is the result of one or more chemical transformations of one or more raw materials of natural, non-fossil origin. Biogenic N-vinylformamide may also be referred to as biogenic or bioderived N-vinylformamide.

[0115] Acetaldehyde and / or formamide, preferably both, may be non-isolated, partially isolated or completely isolated. The preferences in the "Process" section apply to this section describing the monomers.

[0116] In one embodiment, acetaldehyde and / or formamide, preferably both, may be partially or fully recycled. The preferences in the "Process" section apply to this section describing the monomers.

[0117] In this embodiment, the monomer of the present invention is obtained by a process comprising the following steps:

[0118] - recovery of at least one renewable and non-fossil raw material to obtain acetaldehyde and / or formamide;

[0119] - reacting the acetaldehyde and / or formamide to obtain N-vinylformamide monomer.

[0120] The polymer of the present invention

[0121] The present invention relates to a polymer obtained by polymerizing at least one N-vinylformamide monomer obtained by the process according to the present invention. The present invention also relates to a polymer obtained by polymerizing at least one N-vinylformamide monomer as described above. The same embodiments and preferences as in the "Process" section apply to this section.

[0122] The polymers according to the invention are preferably water-soluble or water-swellable. The polymers may also be superabsorbents.

[0123] The polymers of the invention may be homopolymers or copolymers with at least one N-vinylformamide monomer obtained according to the process of the invention or at least one N-vinylformamide monomer previously described and at least one different additional monomer, the latter preferably being chosen from at least one nonionic monomer, and / or at least one anionic monomer, and / or at least one cationic monomer, and / or at least one zwitterionic monomer, and / or at least one monomer comprising a hydrophobic group.

[0124] Thus, the copolymer may comprise at least one second monomer different from the first monomer of the present invention (the N-vinylformamide of the present invention), the second monomer being selected from nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, monomers comprising hydrophobic groups, and mixtures thereof.

[0125] The nonionic monomer is preferably selected from the group consisting of acrylamide, methacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-hydroxymethylacrylamide, N-vinylformamide (NVF), N-vinylacetamide, N-vinylpyridine and N-vinylpyrrolidone (NVP), N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine (ACMO), acryloyl chloride, glycidyl methacrylate, glyceryl methacrylate and diacetone acrylamide.

[0126] The anionic monomer is preferably selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, acrylamidoundecanoic acid, 3-acrylamido-3-methylbutyric acid, maleic anhydride, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, methylallylsulfonic acid, 2-sulfoethylmethacrylate, sulfopropylmethacrylate, sulfopropylacrylate, allylphosphonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanedisulfonic acid, and water-soluble salts of these monomers, such as their alkali metal salts, alkaline earth metal salts or ammonium salts. Acrylic acid (and / or its salts) and / or ATBS (and / or its salts) are preferred.

[0127] The cationic monomer is preferably selected from the group consisting of quaternized dimethylaminoethyl acrylate (ADAME), quaternized dimethylaminoethyl methacrylate (MADAME), dimethyldiallylammonium chloride (DADMAC), acrylamidopropyltrimethylammonium chloride (APTAC) and methacrylamidopropyltrimethylammonium chloride (MAPTAC).

[0128] The zwitterionic monomers may be derivatives of vinyl type units, in particular acrylamide, acrylic acid, allyl or maleic acid, having an amine or ammonium function (preferably a quaternary ammonium) and an acid function of the carboxylic acid (or carboxylate), sulfonic acid (or sulfonate) or phosphoric acid (or phosphate) type.

[0129] Monomers with hydrophobic properties can also be used to prepare the polymer. Preferably, they are selected from the group consisting of esters of (meth)acrylic acid with alkyl, arylalkyl, propoxylated, ethoxylated or ethoxylated and propoxylated chains; derivatives of (meth)acrylamide with alkyl, arylalkyl, propoxylated, ethoxylated, ethoxylated and propoxylated chains, or dialkyl; alkylarylsulfonates, or mono- or di-substituted amides of (meth)acrylamide with propoxylated, ethoxylated, or ethoxylated and propoxylated alkyl, arylalkyl chains; derivatives of (meth)acrylamide with propoxylated, ethoxylated, ethoxylated and propoxylated alkyl, arylalkyl or dialkyl chains; alkylarylsulfonates.

[0130] Each of these monomers may also be of biological origin.

[0131] According to the invention, the polymer may have a linear, branched, star, comb, dendritic or block structure. These structures can be obtained by selecting initiators, transfer agents, polymerization techniques such as controlled radical polymerization known as RAFT (reversible addition-fragmentation chain transfer), NMP (nitroxide mediated polymerization) or ATRP (atom transfer radical polymerization), incorporation of structural monomers, concentrations ...

[0132] According to the present invention, the polymer is preferably linear and structured. Structured polymer refers to a nonlinear polymer with side chains so that when the polymer is dissolved in water, a significant entanglement state is obtained, resulting in a very low gradient viscosity. The polymer of the present invention can also be cross-linked.

[0133] Additionally, the polymers of the present invention may be structured:

[0134] - by at least one structuring agent which may be chosen from the group consisting of polyethylenically unsaturated monomers (having at least two unsaturated functional groups), such as vinyl functional groups, in particular allyl, acrylic and epoxy functional groups, and mention may be made, for example, of methylenebisacrylamide (MBA), triallylamine or tetraallylammonium chloride or 1,2-dihydroxyethylenebis-(N-acrylamide), and / or

[0135] - by macroinitiators, such as polyperoxides, polyazo compounds and polytransfer agents, such as poly(co)polymers and polyols, and / or

[0136] -Functionalized polysaccharides.

[0137] The amount of branching / crosslinking agent in the monomer mixture is preferably less than 4 wt %, more preferably less than 1 %, even more preferably less than 0.5 wt % relative to the monomer content (weight). According to a specific embodiment, it can be at least equal to 0.00001 wt % relative to the monomer content.

[0138] In a specific embodiment, the polymer of the present invention can be a semi-synthetic and therefore semi-natural polymer. In this embodiment, the polymer can be synthesized by copolymerization of all or part of the grafting of at least one monomer of the present invention and at least one natural compound, and the natural compound is preferably selected from the group consisting of starch and its derivatives, polysaccharides and their derivatives, fibers, plant gums, animal glues or algin and its modified form. For example, plant gums can include guar gum, gum arabic, locust bean gum, tragacanth gum, guar gum, anthocyanin gum, tara gum, cassia gum, xanthan gum, ghatti gum, karaya gum, gellan gum, cyanogen algin, guar gum, soy gum, beta-glucan or dammar gum. The natural compound can also be gelatin, casein or chitosan. For example, algin can include sodium alginate or its acid, agar or carrageenan.

[0139] The polymerization is usually carried out by copolymerization or grafting, but is not limited thereto. Those skilled in the art can refer to the existing common knowledge in the field of semi-natural polymers.

[0140] The invention also relates to a composition comprising at least one polymer of the invention and at least one natural polymer, preferably selected from the natural polymers described previously. The weight ratio of synthetic polymer to natural polymer is generally 90:10 to 10:90. The composition may be in liquid, inverse emulsion or powder form.

[0141] Generally speaking, the polymer does not require the development of a specific polymerization method. In fact, it can be obtained according to all polymerization techniques known to those skilled in the art. Specifically, it can be solution polymerization; gel polymerization; precipitation polymerization; emulsion polymerization (aqueous phase polymerization or reverse phase polymerization); suspension polymerization; reactive extrusion polymerization; water-in-water polymerization; or micellar polymerization.

[0142] The polymerization is typically free radical polymerization, preferably by inverse emulsion polymerization or gel polymerization. Free radical polymerization includes free radical polymerization using UV, azo, redox or thermal initiators as well as controlled radical polymerization (CRP) techniques or matrix polymerization techniques.

[0143] The polymer of the present invention can be modified after being obtained by polymerization. This is called the post-modification of the polymer. All known post-modifications can be applied to the polymer of the present invention, and the invention further relates to the polymer obtained after the post-modification. Among the possible post-modifications developed below, it is possible to mention post-hydrolysis, post-modification by Mannich reaction, post-modification by Hofmann reaction and post-modification by glyoxalation reaction.

[0144] The polymer of the present invention can be obtained by subjecting at least one monomer obtained by the method of the present invention or a polymer obtained by polymerizing at least one monomer as previously described in the "Monomer" section to a post-hydrolysis reaction. Before the post-hydrolysis, the polymer comprises, for example, acrylamide or methacrylamide monomer units. The polymer may further comprise monomer units of N-vinylformamide. More specifically, the post-hydrolysis involves the reaction of a hydrolyzable functional group, preferably a non-ionic monomer unit, more preferably an amide or ester functional group, with a hydrolyzing agent. The hydrolyzing agent may be an enzyme, an ion exchange resin, an alkali metal or a suitable acid compound. Preferably, the hydrolyzing agent is a Bronsted base. When the polymer comprises amide and / or ester monomer units, the post-hydrolysis reaction produces carboxylate groups. When the polymer comprises vinylformamide monomer units, the post-hydrolysis reaction produces amine groups.

[0145] The polymer of the present invention can be obtained by subjecting at least one monomer obtained by the method of the present invention or a polymer obtained by polymerizing at least one monomer as previously described in the "Monomer" section to a Mannich reaction. More specifically, before the Mannich reaction, the polymer preferably comprises acrylamide and / or methacrylamide monomer units. The Mannich reaction is carried out in aqueous solution in the presence of a dialkylamine and a formaldehyde precursor. More preferably, the dialkylamine is dimethylamine and the formaldehyde precursor is formaldehyde itself. After the reaction, the polymer contains a tertiary amine.

[0146] The polymer of the present invention can be obtained by subjecting at least one monomer obtained by the process of the present invention or a polymer obtained by polymerizing at least one monomer as previously described in the "Monomer" section to a Hofmann reaction. Prior to the Hofmann reaction, the polymer preferably comprises acrylamide and / or methacrylamide monomer units. The so-called Hofmann degradation reaction is carried out in aqueous solution in the presence of alkaline earth metal and / or alkali metal hydroxides and alkaline earth metal and / or alkali metal hypohalides.

[0147] This reaction was discovered by Hofmann in the late 19th century and is used to convert an amide functional group into a primary amine functional group with one less carbon atom. The detailed reaction mechanism is as follows.

[0148] In the presence of a Brønsted base (eg soda), a proton is abstracted from the amide.

[0149]

[0150] The amide is formed and then reacts with the active chlorine (Cl2) of the chlorate (e.g. NaClO at equilibrium: ) to form N-chloroamide. The Bronsted base (e.g., NaOH) abstracts a proton from the chloroamide to form an anion. The anion loses a chloride ion to form a nitrene, which undergoes an isocyanate rearrangement.

[0151]

[0152] By the reaction between hydroxide ions and isocyanates, carbamates are formed.

[0153]

[0154] Decarboxylation of the carbamate (removal of CO2) affords the primary amine.

[0155]

[0156] In order to convert all or part of the amide functionality of a (co)polymer comprising amide groups into amine functionality, two main factors are involved (expressed in molar ratios). They are:

[0157] -Alpha = (alkali metal and / or alkaline earth metal subhalide / amide) and

[0158] - Beta = (alkali metal and / or alkaline earth metal hydroxide / alkali metal and / or alkaline earth metal subhalide).

[0159] Polymer of the present invention can also be obtained by carrying out glyoxalation on polymer obtained by at least one monomer obtained by method of the present invention or as previously described in "monomer" chapters and sections, wherein the polymer comprises at least one monomer unit (preferably acrylamide or methacrylamide) by glyoxalation. More specifically, glyoxalation relates to the reaction of at least one aldehyde on polymer, so that the polymer is functionalized. Preferably, aldehyde can be selected from glyoxal, glutaraldehyde, furan dialdehyde, 2-hydroxyhexanedial, succinaldehyde, starch dialdehyde, 2.2 dimethoxyacetaldehyde, diepoxy compounds, and combinations thereof. Preferably, the aldehyde compound is glyoxal.

[0160] According to the invention, the polymer may be in liquid, gel or solid form, when prepared including a drying step, such as spray drying, drum drying, radiation drying (such as microwave drying) or fluidized bed drying.

[0161] According to the invention, the water-soluble polymer preferably has a molecular weight of 10 to 40 million g / mol. The polymer may be a dispersant, in which case its molecular weight is preferably 1000 to 50,000 g / mol. The polymer may have a higher molecular weight, typically between 10 and 30 million g / mol. The molecular weight is understood to be the weight average molecular weight. The polymer of the invention may also be a superabsorbent capable of absorbing 10 to 500 times its weight in water.

[0162] The molecular weight is preferably determined by the intrinsic viscosity of the (co)polymer. The intrinsic viscosity can be measured by methods known to those skilled in the art, and can be calculated (x-axis) by the reduced viscosity values ​​of different (co)polymer concentrations and the curve is extrapolated to zero concentration by a graphical method that requires plotting the reduced viscosity values ​​(y-axis) relative to the concentration. The intrinsic viscosity values ​​are plotted on the y-axis or using the least square method. The molecular weight can then be determined using the Mark-Houwink equation:

[0163] [η] = KM α

[0164] [η] represents the intrinsic viscosity of the (co)polymer determined by a solution viscosity measurement method.

[0165] K represents an empirical constant.

[0166] M represents the molecular weight of the (co)polymer.

[0167] α represents the Mark-Houwink coefficient.

[0168] K and α depend on the specific (co)polymer-solvent system.

[0169] The comonomers combined with the monomers of the present invention to obtain the polymers of the present invention are preferably at least partially or more preferably completely renewable and non-fossil.

[0170] Therefore, in a preferred embodiment, the present invention relates to a polymer comprising:

[0171] at least 5 mol %, preferably at least 10 mol %, preferably from 20 mol % to 99 mol %, more preferably from 30 mol % to 90 mol % of a first monomer, said monomer being a monomer of the present invention, and

[0172] - at least 1 mol %, preferably 5 to 90 mol %, more preferably 10 to 80 mol %, of at least one second monomer comprising ethylenic unsaturation, which is different from the first monomer and is at least partly renewable and non-fossil.

[0173] Therefore, in a preferred embodiment, the present invention relates to a polymer comprising:

[0174] at least 5 mol %, preferably at least 10 mol %, preferably from 20 mol % to 99 mol %, more preferably from 30 mol % to 90 mol % of a first monomer, said monomer being a monomer of the present invention; and

[0175] - at least 1 mol %, preferably from 5 mol % to 90 mol %, more preferably from 10 mol % to 80 mol %, of at least one second monomer comprising ethylenic unsaturation, which second monomer is different from the first monomer and is at least partly renewable and non-fossil;

[0176] - at least 1 mol %, preferably 5 to 90 mol %, more preferably 10 to 80 mol % of at least one third monomer comprising ethylenic unsaturation, which is different from the first and second monomers and is at least partly renewable and non-fossil.

[0177] The polymers of the present invention may comprise four or more different monomers.

[0178] In a preferred embodiment, the second monomer and possible other monomers have a biogenic carbon content of 5 wt% to 100 wt%, preferably 10 wt% to 100 wt%, relative to the total carbon weight in the relevant monomers, and the biogenic carbon content is determined according to ASTM D6866-21 Method B.

[0179] In a preferred embodiment of the present invention, the second monomer and any additional monomers are selected from the group consisting of acrylamide, (meth)acrylic acid and / or its salts, 2-acrylamido-2-methylpropanesulfonic acid (ATBS) and / or its salts, N-vinylpyrrolidone (NVP), dimethylaminoethyl methacrylate and its quaternized forms, dimethyldiallylammonium chloride (DADMAC), 1 R 2 Substituted acrylamide, R 1 and R 2 Each independently is a straight or branched carbon chain C n H 2n+1 , where n is 1 to 10.

[0180] Throughout the present invention, it is understood that the mole percentages of monomers (excluding any crosslinking agent) of a polymer equal 100%.

[0181] The present invention also relates to a polymer obtained by polymerizing at least one N-vinylformamide monomer obtained by the process according to the present invention or the aforementioned N-vinylformamide monomer, which is then partially or completely hydrolyzed with acid or base to convert at least one N-vinylformamide monomer unit into N-vinylamine.

[0182] In this embodiment, the polymer before hydrolysis is a polymer preferably comprising at least 80 mol% of N-vinylformamide monomer units. Preferably, it is an N-vinylformamide homopolymer. The hydrolysis rate can be 20% to 100%, preferably 25% to 90%, even more preferably 30% to 80%, which hydrolysis rate represents the percentage of N-vinylformamide monomer units converted into vinylamine monomer units relative to the total amount of N-vinylformamide monomer units in the polymer before hydrolysis.

[0183] In this embodiment, the hydrolysis is preferably carried out on an N-vinyl formamide homopolymer. The polymer obtained after the hydrolysis is a vinyl formamide / vinyl amine copolymer or a vinyl amine homopolymer. The molar percentage of vinylamine units of the polymer (or homopolymer) is preferably between 20% and 100%, preferably between 25% and 90%, even more preferably between 30% and 80%.

[0184] Preferably, the biogenic carbon content of the polymer is between 5% and 100% by weight relative to the total carbon mass in the polymer of the invention, the biogenic carbon content being determined according to standard ASTM D6866-21 method B.

[0185] The invention also relates to the use of at least one N-vinylformamide monomer obtained by the process according to the invention or as described above for the synthesis of polymers.

[0186] Use of the polymers of the present invention

[0187] The invention also relates to the use of the polymers of the invention in: hydrocarbon (oil and / or gas) recovery; drilling and cementing; stimulation of hydrocarbon wells (oil and / or gas); for example hydraulic fracturing, structuring, diversion; water treatment in open, closed or semi-closed circuits; fermentation slurry treatment, sludge treatment; papermaking; construction; wood processing; hydraulic composition processing (concrete, cement, mortar and aggregates); mining; cosmetic formulations; detergent formulations; textile manufacturing; battery component manufacturing; geothermal energy; sanitary napkin manufacturing; or agriculture.

[0188] The invention also relates to the use of the polymers of the invention as flocculants, coagulants, adhesives, fixatives, viscosity reducers, thickeners, absorbents, drag reducers, dehydrating agents, drainage agents, charge retaining agents, water removers, conditioners, stabilizers, film formers, sizing agents, superplasticizers, clay inhibitors or dispersants.

[0189] Methods of using the polymers of the present invention

[0190] The invention also relates to various methods described below, in which the polymers of the invention are used to improve application properties.

[0191] The present invention also relates to a method for improving oil and / or gas recovery by cleaning an underground formation, comprising the following steps:

[0192] a. preparing an injection fluid by the polymer of the present invention and water or saline,

[0193] b. injecting the injection fluid into the underground formation,

[0194] c. Cleaning underground formations with injected fluids,

[0195] d. Recovery of aqueous mixtures of oil and / or gas.

[0196] The present invention also relates to a method for hydraulic fracturing of an underground oil and / or gas reservoir, comprising the following steps:

[0197] a. preparing an injection fluid from a polymer of the present invention with water or brine and with at least one proppant,

[0198] b. Injecting the fluid into a subterranean reservoir and fracturing at least a portion thereof to recover oil and / or gas.

[0199] In the method described above, the polymer is preferably a high molecular weight polymer (greater than 8 million Daltons). It is preferably linear. It is preferably in the form of a powder, an inverse emulsion, a partially dehydrated inverse emulsion, or in a "transparent" form, i.e. a dispersion of solid polymer particles in an aqueous or oily fluid. The powder form is preferably obtained by gelling or spray drying of an inverse emulsion. It also relates to a composition comprising an inverse emulsion of the polymer of the invention and solid particles of the polymer of the invention.

[0200] The present invention also relates to a method for increasing the production of an underground formation, comprising the following steps:

[0201] a. preparing an injection fluid by the polymer of the present invention and water or saline,

[0202] b. injecting the injection fluid into the underground formation,

[0203] c. Partial or complete plugging of a subterranean formation with injected fluids, either temporarily or permanently.

[0204] The invention also relates to a method for drilling and / or cementing a well in an underground formation, comprising the following steps:

[0205] a. preparing an injection fluid by the polymer of the present invention and water or saline,

[0206] b. Injecting drilling and / or cementing fluid into a subterranean formation via the drill bit during at least one step of drilling or cementing.

[0207] Drilling and cementing are two consecutive steps in drilling a well in an underground formation. The first step is drilling with a drilling fluid and the second step is cementing with a cementing fluid. The present invention also relates to a method of injecting an intermediate fluid ("spacer") between the drilling fluid and the cementing fluid, the intermediate fluid comprising at least one polymer of the present invention. The intermediate fluid prevents contamination between the cementing fluid and the drilling fluid.

[0208] When drilling and cementing a well, the polymers of the present invention can be used as fluid loss additives in well cement compositions to reduce fluid loss from the cement composition from the permeable formation or zone that is pumped into or through. During primary cementing, fluid (i.e., water) loss to the permeable formation or subterranean zone can cause premature gelling of the cement composition, bridging the annular space between the permeable formation or zone and the drill string cemented therein, which can prevent the cement composition from being placed along the entire length of the annulus.

[0209] The invention also relates to a method for inerting clay in a hydraulically setting composition for construction purposes, comprising the step of adding at least one clay inerting agent to the hydraulically setting composition or one of its components, characterized in that the clay inerting agent is a polymer according to the invention.

[0210] Clay absorbs moisture and leads to a deterioration in the properties of building materials. When the polymer according to the invention is used as a clay inhibitor, it allows in particular to avoid clay swelling which could lead to cracks and thus weaken any building.

[0211] The hydraulic composition may be concrete, cement, mortar or aggregate. Preferably, the polymer is added to the hydraulic composition or one of its components at a dosage of 2 to 200 ppm of inert agent relative to the weight of the aggregate.

[0212] In the method for inertizing clay, the clay includes but is not limited to 2:1 expanded clay (e.g., montmorillonite), or 1:1 expanded clay (e.g., kaolin) or 2:1:1 expanded clay (e.g., chlorite). The term "clay" generally refers to magnesium silicate and / or aluminum silicate, including layered silicates having a layered structure. However, in the present invention, the term "clay" also includes clays that do not have such a structure, such as amorphous clay.

[0213] The invention also relates to a method for making paper, paperboard, etc., wherein before forming the paper, the following steps are performed: at least one polymer of the invention is added to the fiber suspension at one or more injection points. The polymer may provide dry strength or retention properties or wet strength. It may also improve paper flatness, drainage and dewatering capabilities.

[0214] The method can be successfully used to manufacture packaging paper and paperboard, coated paper, hygiene and household paper, any type of paper, paperboard, etc.

[0215] The post-modified polymers described in the chapter "Polymers", in particular post-modified polymers by Hofmann reaction or by glyoxalation reaction, are particularly advantageous in processes for the manufacture of paper, board and the like.

[0216] Retention properties are understood to mean the ability to retain the suspended materials of the pulp (fibers, fines, fillers (calcium carbonate, titanium oxide)...) on the forming fabric and thus in the fibers that will constitute the final paper. The mode of action of retention aids is based on the flocculation of these suspended substances in water. In fact, the flocs formed are more easily retained on the forming sheet.

[0217] Filler retention involves the exclusive retention of fillers (small mineral species with little affinity for cellulose). Significant improvements in filler retention result in white water clarification by retaining the fillers in the sheet and increasing its grammage. It also allows replacing part of the fibers (the most expensive species in the composition of paper, paperboard or similar materials) with fillers (lower cost) to reduce manufacturing costs.

[0218] With respect to dewatering (or drainage) performance, it is the ability of the fiber mat to evacuate or drain the maximum amount of water so that the sheet dries as quickly as possible, especially during the manufacture of the sheet.

[0219] These two properties (retention and drainage) are intricately linked, one depends on the other, so the problem is to find the best compromise between retention and drainage. Usually, the skilled person refers to retention aids and drainage agents, because they are the same type of products used to improve both properties.

[0220] The fiber suspension is understood to mean a thick or thin stock consisting of water and cellulose fibers. A thick stock with a dry matter concentration of more than 1% or even more than 3% is located upstream of the fan pump. A thin stock with a dry matter concentration of generally less than 1% is located downstream of the fan pump.

[0221] The polymer can be added to the thick stock or the thin stock. It can be added at the level of the blower pump or the headbox. Preferably, the polymer is added before the headbox.

[0222] In the process for making paper, board etc. the polymer of the invention can be used alone or in combination with a second retention aid. Preferably, a second retention aid selected from organic polymers and / or inorganic microparticles is added to the fiber suspension.

[0223] This second retention aid added to the fiber suspension is preferably selected from anionic polymers in a broad sense, thus it can be (but not limited to) linear, branched, cross-linked, hydrophobic, associative and / or inorganic microparticles (e.g. bentonite, colloidal silica).

[0224] The invention also relates to a method for treating a suspension of solid particles in water resulting from mining or oil sands operations, comprising contacting the suspension with at least one polymer of the invention. This method can be carried out in a thickener, which is a holding area, usually in the form of a pipe section of several meters in diameter, with a conical bottom, in which the particles can settle. According to one embodiment, the aqueous suspension is conveyed to the thickener by a pipeline and the polymer is added to the pipeline.

[0225] According to another embodiment, a polymer is added to a thickener that already contains a suspension to be treated. In a typical beneficiation operation, the suspension is usually concentrated in a thickener. This results in a denser sludge discharged from the bottom of the thickener, and an aqueous fluid released from the treated suspension (referred to as liquid) is discharged from the top of the thickener by overflow. In general, the addition of a polymer increases the concentration of the sludge and increases the clarity of the liquid.

[0226] According to another embodiment, a polymer is added to the particle suspension during the process of conveying the suspension to a deposition area. Preferably, the polymer is added to a pipeline that conveys the suspension to the deposition area. It is on this deposition area that the treated suspension is spread in preparation for dehydration and solidification. The deposition area can be open (e.g., an unrestricted soil area) or closed, such as a trough or a small chamber.

[0227] An example of such treatment during the transport of the suspension is spreading a suspension treated with the polymer of the invention on soil in preparation for dewatering and solidification, and then spreading a second layer of the treated suspension on top of the solidified first layer. Another example is the continuous spreading of the suspension treated with the polymer of the invention so that the treated suspension continuously falls on the suspension previously discharged into the deposition area, thereby forming a large amount of treated material from which water has been extracted.

[0228] According to another embodiment, a water-soluble polymer is added to the suspension and subjected to a mechanical treatment, such as centrifugation, pressing or filtration.

[0229] The water-soluble polymer can be added simultaneously at different stages of the treatment of the suspension, ie, for example, in the pipeline conveying the suspension to the thickener and in the sludge leaving the thickener to be conveyed to a sedimentation area or to a mechanical treatment unit.

[0230] The present invention also relates to a method for treating urban or industrial water, comprising introducing at least one polymer of the present invention into the water to be treated. Effective water treatment requires the removal of dissolved compounds and dispersed and suspended solids in the water. Typically, this treatment is enhanced by chemicals such as coagulants and flocculants. These are typically added to the water stream before separation units (e.g., flotation and sedimentation).

[0231] The polymers of the present invention can be preferably used to coagulate or flocculate suspended particles in urban or industrial wastewater. Generally, they are used in combination with inorganic coagulants such as alum.

[0232] They can also be preferably used to treat the sludge produced by treating the wastewater. Sewage sludge (whether municipal sludge or industrial sludge) is the main waste generated by treatment plants from liquid wastewater. Generally speaking, sludge treatment includes dewatering. This dewatering can be carried out by centrifugation, filter press, belt press, electric dewatering, sludge drying reed bed, solar drying. It is used to reduce the sludge water concentration.

[0233] In the municipal or industrial water treatment method, the polymer of the present invention is preferably linear or branched. It is preferably in the form of a powder, an inverse emulsion or a partially dehydrated inverse emulsion. The powder form is preferably obtained from the inverse emulsion by gel or spray drying.

[0234] The invention also relates to an additive for a cosmetic, dermatological or pharmaceutical composition, said additive comprising at least one polymer according to the invention. The invention also relates to the use of a polymer according to the invention in the manufacture of said composition as a thickener, regulator, stabilizer, emulsifier, fixative or film former. The invention likewise relates to a cosmetic, dermatological or pharmaceutical composition comprising at least one polymer according to the invention.

[0235] In particular, reference may be made to the application FR2979821 on behalf of L'OREAL for the description of the manufacture of such compositions and other ingredients of such compositions. The composition may be in the form of a milk, lotion, gel, cream, gel cream, soap, bubble bath, balm, shampoo or conditioner. The use of the composition for the cosmetic or dermatological treatment of keratin materials such as the skin, scalp, eyelashes, eyebrows, nails, hair and / or mucous membranes is also an integral part of the invention. This use comprises applying the composition to the keratin material, possibly followed by rinsing with water.

[0236] The present invention also relates to an additive for a detergent composition, the additive comprising at least one polymer of the present invention. The present invention also relates to the use of the polymer of the present invention in the manufacture of the composition as a thickener, regulator, stabilizer, emulsifier, fixer or film former. The present invention also relates to a detergent composition for household or industrial use comprising at least one polymer of the present invention. In particular, the description of the other ingredients of such compositions and the preparation of such compositions can be made with reference to the applicant's application WO2016020622.

[0237] "Detergent compositions for household or industrial use" are understood to mean compositions for cleaning various surfaces, in particular textile fibers, hard surfaces of any kind (e.g. dishes, floors, windows, wood, metal or composite surfaces). Such compositions include, for example, detergents for washing clothes manually or in a washing machine, products for cleaning dishes manually or in a dishwasher, detergent products for washing the interior of the house (e.g. kitchen elements, toilets, furniture, floors, windows) and other cleaning products for general use.

[0238] The polymer used as an additive, e.g. thickener, for cosmetic, dermatological, pharmaceutical or detergent compositions is preferably crosslinked. It is preferably in the form of a powder, an inverse emulsion or a partially dehydrated inverse emulsion. The powder form is preferably obtained from the inverse emulsion by spray drying.

[0239] The invention likewise relates to a thickener for a pigment composition for textile printing, the thickener comprising at least one polymer according to the invention. The invention also relates to a sizing agent for textile fibers, the agent comprising at least one polymer according to the invention.

[0240] The invention also relates to a process for making a superabsorbent from the monomers of the invention, a superabsorbent obtained from at least one monomer of the invention for absorbing and retaining water in agricultural applications or for absorbing aqueous liquids in sanitary napkins. For example, the superabsorbent is a polymer of the invention.

[0241] The invention furthermore relates to a process for producing sanitary napkins, in which the polymers according to the invention are used, for example as superabsorbents.

[0242] The present invention also relates to the use of the polymer of the present invention as a battery binder. The present invention also relates to a battery binder composition comprising the polymer of the present invention, an electrode material and a solvent. The present invention also relates to a method for making a battery comprising preparing a gel comprising at least one polymer of the present invention and filling the battery. For example, lithium-ion batteries are used in a variety of products, including medical devices, electric vehicles, aircraft, and most importantly, consumer products such as laptops, mobile phones and cameras.

[0243] Typically, a lithium-ion battery (LIB) includes an anode, a cathode, and an electrolyte material (e.g., an organic solvent containing a lithium salt). More specifically, the anode and cathode (collectively referred to as "electrodes") are formed by mixing an electrode active material (anode or cathode) with a binder and a solvent to form a paste or slurry, which is then applied to a current collector (e.g., aluminum or copper) and dried to form a film on the current collector. The anode and cathode are then stacked and wound, and then loaded into a pressurized casing containing an electrolyte material, all of which together form a lithium-ion battery.

[0244] In lithium batteries, binders play an important role in mechanical and electrochemical performance. First, it helps to disperse the other ingredients in the solvent during the manufacturing process (some also act as thickeners) so that they are evenly distributed. Second, it holds the various components together, including the active component, any conductive additives, and the current collector, ensuring that all of these parts remain in contact. Through chemical or physical interactions, the binder connects these individual components, holding them together and ensuring the mechanical integrity of the electrode without material effects on electronic or ionic conductivity. Third, it often acts as an interface between the electrode and the electrolyte. In this role, it protects the electrode from corrosion or the electrolyte from depletion while facilitating ion transport across this interface.

[0245] Another important point is that the adhesives must have a certain degree of flexibility so that they do not break or develop defects. Brittleness can cause problems during the manufacturing or assembly of the battery.

[0246] Given all the roles it plays in the electrode (and the battery as a whole), binder selection is critical to ensuring good battery performance.

[0247] The invention furthermore relates to a process for producing sanitary napkins, in which the polymers according to the invention are used, for example as superabsorbents.

[0248] As mentioned earlier, the circular economy is an economic system that is committed to efficiency and sustainability by optimizing the value generated from resources to minimize waste. It relies heavily on various conservation and recycling practices to move away from the current more linear "take-make-dispose" path.

[0249] Therefore, as material recycling becomes a major concern, recycling processes are rapidly developing and are able to produce materials that can be used to create new compounds or objects. Recycling materials does not depend on the origin of the material, as long as it can be recycled, it is considered a technological advancement. Although the source of the material to be recycled may be renewable and non-fossil, it may also be fossil.

[0250] The specific purposes are as follows.

[0251] A process for obtaining N-vinylformamide comprises the reaction between acetaldehyde and formamide, one of which, preferably both, originates at least partially, preferably entirely, from a recovery process of renewable and non-fossil materials, or from fossil materials.

[0252] Preferably, acetaldehyde and / or formamide, preferably both, are completely "separated", i.e. separated from separate pipelines and processed separately. In another embodiment, they are (are) partly "separated" and partly "non-separated". In this case, the weight ratio between the "separated" part and the "non-separated" part is preferably between 99:1 and 25:75, preferably between 99:1 and 50:50. In another embodiment, they are (are) completely "non-separated".

[0253] N-vinylformamide can be obtained by reaction between acetaldehyde and formamide, said acetaldehyde and / or said formamide, preferably both, originating at least partly, preferably completely, from a recycling process of renewable and non-fossil materials, or from fossil materials.

[0254] A polymer obtained by polymerizing at least one N-vinylformamide monomer as previously described.

[0255] Use of polymers obtained by polymerizing at least one N-vinylformamide monomer as described above in: oil and / or gas recovery, drilling and cementing; oil and / or gas well stimulation (e.g. hydraulic fracturing, construction, diversion), water treatment in open, closed or semi-closed circuits, fermentation slurry treatment, sludge treatment, papermaking, construction industry, wood processing, hydraulic composition processing (concrete, cement, mortar and aggregates), mining, cosmetic formulations, detergent formulations, textile manufacturing, battery component manufacturing; geothermal energy; or agriculture.

[0256] Use of a polymer obtained by polymerizing at least one N-vinylformamide monomer as described above as a flocculant, coagulant, adhesive, fixative, viscosity reducer, thickener, absorbent, drag reducer, dehydrating agent, drainage agent, charge retaining agent, water remover, regulator, stabilizer, film former, sizing agent, superplasticizer, clay inhibitor or dispersant.

[0257] A polymer obtained according to a process comprising the steps of:

[0258] - recovery of at least one renewable and non-fossil or fossil raw material to obtain acetaldehyde and / or formamide;

[0259] - reacting the acetaldehyde with the formamide to obtain N-vinylformamide;

[0260] - polymerizing the N-vinylformamide and optionally another ethylenically unsaturated monomer. BRIEF DESCRIPTION OF THE DRAWINGS

[0261] Figure 1 The formation of NVF from acetaldehyde and formamide is shown.

[0262] Figure 2 The vacuum drainage performance at 1kg / mt and 1.5kg / mt is shown.

[0263] Example

[0264] The following examples relate to the synthesis of biogenic N-vinylformamide (hereinafter abbreviated to NVF) according to the invention, comprising the reaction between acetaldehyde (hereinafter abbreviated to ACH) and formamide (hereinafter abbreviated to FAM), one of which, preferably both, are at least partly of renewable and non-fossil origin (see Figure 1 ). They also relate to the synthesis and use of biosourced polymers obtained from at least one biosourced N-vinylformamide monomer of the invention.

[0265] The following examples are provided to best illustrate the advantages of the present invention.

[0266] Purity Test Description.

[0267] The synthesis of NVF is carried out in two steps. First, hydroxyethylformamide is obtained from acetaldehyde and formamide. Then, hydroxyethylformamide is converted into methoxyethylformamide (hereinafter referred to as MEF) by reacting with methanol and a catalyst. Then methoxyethylformamide is pyrolyzed at high temperature to obtain N-vinylformamide.

[0268] The purity of NVF was determined by high performance liquid chromatography, and the analytical conditions were as follows (Table 2):

[0269]

[0270] Table 2

[0271] Using these conditions, and by measuring the areas of the various impurity peaks, the purity of NVF can be calculated.

[0272] The quantification of formamide and methoxyethylformamide was performed by calibration with standards.

[0273] The retention time of formamide was 1.43 minutes, and the retention time of methoxyethylformamide was 4.5 minutes.

[0274] I. Synthesis of some biologically derived NVF

[0275] Example 1: Synthesis of NVF using partially renewable and non-fossil-derived FAM and fossil-derived ACH

[0276] By varying the source of formamide and its 14The percentages in C were tested for a set of: FAM CE1 of fossil origin and FAMs Inv 1 to Inv 7 of partially renewable and non-fossil origin (Table 3).

[0277] 14 The level of C is measured according to standard ASTM D6866-21 method B. This standard allows the characterization of the biogenic nature of a compound by determining its biogenic carbon level.

[0278] "Zero" wt% 14 C means that there is no measurable 14 C, thus indicating a fossil carbon source.

[0279] As shown in Table 3, non-fossil-derived formamide comes from various sources, such as the processing of residues from the pulp industry ("tall oil") or agricultural waste to form the precursors formic acid (via biomethanol) or ethyl formate (via bioethane), or from the treatment of municipal waste, biomass, or fermentation or carbon dioxide recovery. Even the amino part of the formamide can come from green ammonia.

[0280] The procedure for each test was as follows: 800 g of toluene was added to a 2000 mL reactor equipped with a jacket, stirrer and condenser.

[0281] The reactor was degassed with nitrogen to remove the air present therein.

[0282] The reactor was maintained at a temperature of 20° C. so that 235 g of acetaldehyde could be added thereto.

[0283] The feeding funnel was charged with 200 g of formamide containing 1.33 g of potassium bicarbonate.

[0284] 20% of the contents of the dropping funnel were added to the reactor within 30 minutes while maintaining the reaction medium at 20°C, and then 0.5 g of hydroxyethylformamide crystals were added to the reaction medium as crystallization seeds. After waiting for 30 minutes, the remaining amount of formamide and potassium bicarbonate in the dropping funnel were added to the reaction medium over a period of 3 hours. The temperature was maintained at 20°C throughout the reaction to prevent evaporation loss of acetaldehyde.

[0285] The hydroxyethylformamide is obtained as a white solid suspended in toluene, which is separated by Buchner filtration. The solid obtained is added again to the reactor, and then 430 g of methanol and 3.5 g of 98% concentrated sulfuric acid aqueous solution are added. The mixture is heated at a temperature of 25° C. for 2 hours. At the end of the reaction, 20% sodium hydroxide is added to neutralize the acidity of the medium caused by sulfuric acid. The sulfate is separated by filtration.

[0286] The liquid obtained is composed of methoxyethylformamide, toluene, methanol and by-products. The reactor condenser is replaced with a 20 cm high glass column filled with a Propack type filler. The entire mixture is placed under a vacuum of 10 mbar (1 bar=0.1 MPa) and the reactor is heated to 60 ° C. The light product fraction is discarded, and only the fraction corresponding to pure methoxyethylformamide is retained.

[0287] The pyrolyzer was equipped with a tube of 10 mm in diameter and 20 cm in length and heated by an external resistor. Methoxyethylformamide was charged into a jacketed reactor, the gas phase of which was connected to the inlet of the pyrolyzer. A 5° glycol water condenser was connected to the outlet of the pyrolyzer. The entire apparatus was placed under a vacuum of 90 mbar and the pyrolyzer was heated to a temperature of 430° C. The jacketed reactor was heated to a temperature of 150° C. to evaporate the methoxyethylformamide.

[0288] The pyrolysis gas was cooled by a condenser and collected in a glass flask. The obtained liquid was distilled under reduced pressure with a rotary evaporator to remove methanol. The remaining N-vinylformamide in the flask was weighed to determine the reaction yield relative to the starting formamide, and analyzed by liquid chromatography to determine the content of formamide and methoxyethylformamide impurities.

[0289]

[0290] Table 3 (CE=counterexample; Inv=embodiment according to the invention)

[0291] Applicants have discovered that the biogenic nature of formamide can lead to better conversions and produce fewer impurities.

[0292] Example 2: Synthesis of NVF using fossil-based FAM and partially renewable non-fossil ACH.

[0293] According to the scheme described above, by adjusting the source of ACH and its 14 The percentage of C was tested in a set of samples: ACH CE 2 of fossil origin and ACH Inv 8 to Inv 14 of partially renewable and non-fossil origin (Table 4).

[0294] Acetaldehyde of non-fossil origin comes from the treatment of residues from the pulp industry ("tall oil"), or from agricultural waste to form bioethanol or bioethane precursors, or from the treatment of municipal waste, biomass, or fermentation or carbon dioxide recovery.

[0295] As mentioned above, the content of various ACHs was determined according to standard ASTM D6866-21 method B. 14 C ratio.

[0296]

[0297] Table 4 (CE = counterexample; Inv = embodiment of the present invention)

[0298] Applicants have discovered that when the ACH is at least partially of renewable and non-fossil origin, the conversion percentage of FAM is greater.

[0299] Example 3: Synthesis of NVF used in the present invention

[0300] According to the previously described protocol, by adjusting the sources of FAM and ACH (see Examples 1 and 2) and their 14 A set of tests was conducted using the percentage of C: comparing monomer CE 3 and monomers M1 to M7 of the invention (Table 5).

[0301] monomer CE 3 M1 M2 M3 M4 M5 M6 M7 FAM Source CE 1 Inv 2 Inv 3 Inv 1 Inv 4 Inv 5 Inv 6 Inv 7 ACH Sources CE 2 Inv 8 Inv 9 Inv 10 Inv11 Inv 12 Inv 13 Inv 14 FAM conversion % 78 80 82 79 80 82 85 88 FAM in the obtained NVF (%) 2.5 2 1.9 2.1 2 1.5 1 0.9 MEF in NVF obtained (%) 4 3.7 3.6 3.5 3.7 2.1 1.8 1.2

[0302] Table 5 (CE = counterexample; Inv = embodiment of the present invention)

[0303] The Applicant has found that, according to the present invention, the use of FAM of partly or fully renewable and non-fossil origin and of ACH of partly or fully renewable and non-fossil origin makes it possible to optimize the process for obtaining NVF.

[0304] II. Synthesis and use of bio-sourced polymers of the present invention:

[0305] Example 4: Synthesis and biodegradability of polymers P1 to P4 according to the invention and comparative polymer CE 4 (Table 6)

[0306] 350 g of deionized water was added to a 1000 mL jacketed reactor equipped with a condenser and a stirrer.

[0307] The pH was adjusted to 6.5 by adding 75% phosphoric acid diluted in water or 20% sodium hydroxide diluted in water.

[0308] The solution thus obtained was heated to 80°C and bubbled with nitrogen for 30 minutes to eliminate all traces of dissolved oxygen.

[0309] The following were then added to the reactor:

[0310] 120 g of N-vinylformamide obtained according to one of the preceding examples are added continuously over 120 minutes.

[0311] - At the same time, 0.54 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride dissolved in 7 g of water was added continuously over 180 minutes.

[0312] After addition of the above reagents, the reaction medium is maintained at 80° C. for 60 minutes. A viscous liquid is then obtained.

[0313] 20 g of 40% strength sodium bisulfite and then 295 g of 25% sodium hydroxide are added to the reaction medium (wt% in water).

[0314] The hydrolysis of the polymer was therefore carried out at 80°C for 300 minutes.

[0315] The obtained product was cooled to 30°C, and then 130 g of a 22% concentrated hydrochloric acid aqueous solution was added to neutralize excess sodium hydroxide.

[0316] The biodegradability of the obtained polymers (after 28 days) was evaluated according to the OECD 302B standard (Table 6).

[0317]

[0318] Table 6 (CE = Counterexample)

[0319] The polymers P1 to P4 according to the invention obtained from monomers of partly or entirely biogenic origin are more biodegradable than the polymer CE 4 obtained from fossil monomers.

[0320] Example 5: Use of the polymer of the present invention as an additive in a papermaking process.

[0321] Retention aids are polymers added to cellulose fiber pulp prior to papermaking to improve the retention efficiency of the paper.

[0322] Type of pulp used: Recycled fiber pulp

[0323] Wet pulp is obtained by comminuting dry pulp to obtain a final water concentration of 1 wt%. It is a neutral pH pulp made from 100% recycled paperboard fibers.

[0324] A / Drainage Performance Assessment (DDA)

[0325] The DDA ("Dynamic Drainage Analyzer") can automatically determine the time (in seconds) required to drain a fiber suspension under vacuum. The polymer was added to the wet pulp (0.6 liters of pulp, 1.0 wt%) in the DDA drum at a speed of 1000 rpm (revolutions per minute):

[0326] T = 0 seconds: stirring pulp

[0327] T = 20 seconds: Add polymer

[0328] T=30 s: Stop stirring and drain under vacuum at 200 mbar for 70 s.

[0329] The pressure under the cloth is recorded as a function of time. When all the water has been drained from the fiber mat, air passes through it, resulting in a slope interruption in the curve, representing the pressure under the cloth as a function of time. The time recorded at the slope interruption (expressed in seconds) corresponds to the drainage time. The shorter the time, the better the vacuum drainage effect. The results are shown in Figure 1. Figure 2As shown (vacuum drainage performance at 1kg / mt and 1.5kg / mt).

[0330] The polymers P1 to P4 according to the invention enable significantly better vacuum drainage properties to be achieved than the CE4 polymer of fossil origin.

[0331] Performance in B / DSR applications (dry strength), grammage 90g.m - 2

[0332] The paper form is made using an automatic dynamic form. First, a pulp is prepared by dissociating 90 g of virgin kraft fiber in 2 liters of hot water for 30 minutes. The obtained pulp is then diluted to a total volume of 9 liters. Once the consistency is accurately measured, the necessary amount of pulp is removed to obtain a final weight of 90 g / m 2 of paper.

[0333] The pulp is then introduced into the trough of a dynamic paper machine and moderately stirred with a mechanical stirrer to homogenize the fiber suspension.

[0334] In manual mode, the pulp is pumped to the height of the nozzle to start the circuit. The blotting paper and the forming cloth are placed in the drum of the dynamic paper former, and then the drum is rotated at a speed of 1000m / min and a water wall is built. Various dry strength agents are then introduced into the stirred fiber suspension, with a contact time of 30 to 45 seconds for each polymer. The paper is then produced by projecting the pulp into the water wall (in automatic mode) through the nozzle 22 times back and forth. Once the water is drained and the automatic sorting is completed, the forming fabric with the formed fiber network is taken out of the trough of the dynamic former and placed on the table. The dry blotting paper is placed on one side of the wet fiber mat and pressed once with a roller. The whole is turned over and the cloth is cleverly separated from the fiber mat. The second dry blotting paper is placed and the paper (between the two blotting papers) is pressed once while providing a pressure of 4 bars, and then dried on a strong dryer at 117°C for 9 minutes. The two blotting papers are then removed and the paper is stored in a humidity and temperature controlled room (50% relative humidity and 23°C) overnight. All papers obtained by this procedure were then evaluated for wet and dry strength properties as follows.

[0335] The burst (Burst index) was measured according to TAPPI T403 om-02 standard using a MessmerBuchel M 405 burst tester. The results are expressed in kPa. The burst index is expressed in kPa.m2 / g and is determined by dividing this value by the basis weight of the paper tested. The results are expressed as a percentage improvement relative to the blank (Table 7).

[0336] The dry tensile strength was measured in the longitudinal direction using a Testometric AX tensile device. The results are expressed in km and as a percentage improvement relative to the blank (Table 7).

[0337]

[0338] Table 7 (CE = Counterexample)

[0339] The applicant has found that, in addition to better drainage properties, the inventive polymers P1 to P4 exhibit dry strength properties at least comparable to or even better than the comparative polymer CE4.

Claims

1. A process for obtaining N-vinylformamide, comprising the reaction between acetaldehyde and formamide, said acetaldehyde and / or said formamide being at least partially renewable and non-fossil; in, The acetaldehyde and / or formamide has a biogenic carbon content of 40 wt % to 100 wt % relative to the total carbon mass in the acetaldehyde, the biogenic carbon content being determined according to standard ASTM D6866-21 method B; The method is a method for obtaining N-vinylformamide by an alkoxylation process, methanol is used as a protective agent, and the method comprises thermally decomposing N-methoxyethylformamide at a temperature of 200° C. to 600° C. and atmospheric pressure or under partial vacuum, The alkoxylation process comprises the following steps: In the first step, acetaldehyde is contacted with formamide in the presence of a solvent and a base, hydroxyethylformamide crystallizes and precipitates in the reaction medium, and at the end of the first step, the hydroxyethylformamide crystals are separated from the solvent by a filtration step; In the second step, methanol is added to the hydroxyethylformamide crystals, the etherification reaction is catalyzed by an acid source, and the reaction product is methoxyethylformamide; In the third and final step, the methoxyethylformamide thus obtained is subjected to a thermal decomposition reaction in the gas phase.

2. The method according to claim 1, characterized in that The biogenic carbon content of the N-vinylformamide is between 40 wt % and 100 wt % relative to the total carbon mass in the N-vinylformamide, the biogenic carbon content being determined according to standard ASTM D6866-21 method B.

3. A biogenic N-vinylformamide, wherein the biogenic carbon content of the biogenic N-vinylformamide is 40 wt % to 100 wt % relative to the total carbon mass in the biogenic N-vinylformamide, and the biogenic carbon content is determined according to standard ASTM D6866-21 method B.

4. A biogenic N-vinylformamide obtained by the reaction between acetaldehyde and formamide, wherein the biogenic carbon content of the acetaldehyde and / or the formamide is 40 wt % to 100 wt % based on the total mass of carbon in the acetaldehyde and / or the formamide, respectively, and the biogenic carbon content is determined according to standard ASTM D6866-21 method B; The reaction comprises the following steps: In the first step, acetaldehyde is contacted with formamide in the presence of a solvent and a base, hydroxyethylformamide crystallizes and precipitates in the reaction medium, and at the end of the first step, the hydroxyethylformamide crystals are separated from the solvent by a filtration step; In the second step, methanol is added to the hydroxyethylformamide crystals, the etherification reaction is catalyzed by an acid source, and the reaction product is methoxyethylformamide; In the third and final step, the methoxyethylformamide thus obtained is subjected to a thermal decomposition reaction in the gas phase.

5. A polymer obtained by polymerizing at least one N-vinylformamide monomer obtained by the method according to any one of claims 1 or 2 or at least one N-vinylformamide monomer according to any one of claims 3 or 4 and partially or completely acid hydrolyzed or alkaline hydrolyzed to convert at least one N-vinylformamide monomer unit into N-vinylamine; The monomer has a biogenic carbon content of 40 wt % to 100 wt % relative to the total carbon mass of the monomer, the biogenic carbon content being determined according to ASTM D6866-21 Method B.

6. A method for making paper or paperboard, wherein: At least one polymer according to claim 5 is added to the fiber suspension at one or more injection points before forming the paper.

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