Crystal form of potassium 2-acrylamido-2-methylpropanesulfonate

Abstract

The present invention relates to the crystalline form of potassium 2-acrylamido-2-methylpropanesulfonate, ATBS.K, having a powder X-ray diffraction pattern that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

Description

[Technical Field]

[0001] The present invention relates to the crystalline form of 2-acrylamido-2-methylpropanesulfonic acid. More specifically, the present invention relates to the crystalline form of potassium 2-acrylamido-2-methylpropanesulfonic acid salt. The present invention also relates to a method for obtaining the crystalline form of potassium 2-acrylamido-2-methylpropanesulfonic acid salt, and polymers obtained from this crystalline form. [Background technology]

[0002] 2-acrylamido-2-methylpropanesulfonic acid, also known as ATBS, is widely used in various fields, including the petroleum and gas industry, mining, construction, textiles, water treatment (seawater desalination, mineral industry, etc.), and cosmetics, as an additive to acrylic fibers, or as a raw material for manufacturing polymers used as dispersants, thickeners, friction reducers, flocculants, or superabsorbents.

[0003] The reaction carried out in the method for producing 2-acrylamido-2-methylpropanesulfonic acid corresponds to the following reaction scheme, in which acrylonitrile is present in excess during the reaction to serve as both the reaction solvent and the reagent. Acrylonitrile is brought into contact with fuming sulfuric acid (oleum) and isobutylene.

[0004] [ka]

[0005] One of the by-products that can be generated during this synthesis is acrylamide.

[0006] 2-Acrylamido-2-methylpropanesulfonic acid is insoluble in acrylonitrile solvent. As a result, the reaction product exists as crystals suspended in the reaction solvent.

[0007] For example, U.S. Patent No. 6,448,347 and Chinese Patent No. 102351744 describe a method for the continuous production of 2-acrylamido-2-methylpropanesulfonic acid. The 2-acrylamido-2-methylpropanesulfonic acid is then typically separated from acrylonitrile by filtration and subsequently dried.

[0008] To reduce the amount of acrylonitrile and acrylamide remaining in the crystal, it is necessary to dry the 2-acrylamido-2-methylpropanesulfonic acid. These two compounds are classified as carcinogenic, mutagenic, or reproductively toxic (CMR). Therefore, in order to lower the levels of acrylonitrile and acrylamide, it is necessary to dehydrate the acrylonitrile as thoroughly as possible by effective filtration, and then dry the 2-acrylamido-2-methylpropanesulfonic acid.

[0009] Those skilled in the art will recognize that 2-acrylamido-2-methylpropanesulfonic acid crystals have a crystallographic configuration that produces needle-shaped solid crystals.

[0010] Needle-shaped crystals are known to those skilled in the art to have macroscopic properties that make handling and transporting the solid difficult (low solid fluidity, caking, low resistance to shear stress), and processing difficult (low filtration, difficulty in drying, abrasion).

[0011] In the case of 2-acrylamido-2-methylpropanesulfonic acid, further problems to be faced are generally the small particle size of the needle-shaped crystals, the density of the solid in question, and the explosiveness of the fine dust.

[0012] These macroscopic properties are directly related to the morphology of the crystal and its specific surface area. Needle-shaped crystals have a large specific surface area.

[0013] International Publication No. 2009 / 072480, Japanese Patent Publication No. 2008-307822, and Japanese Patent Publication No. 2003-137857 describe that the resulting 2-acrylamido-2-methylpropanesulfonic acid crystals are needle-shaped.

[0014] International Publication No. 2018 / 172676, filed by the present applicant, describes a novel form of 2-acrylamide-2-methylpropanesulfonic acid crystals, referred to as the "hydrated crystalline form of 2-acrylamide-2-methylpropanesulfonic acid." This novel crystalline form has different physicochemical properties from the needle-like form and imparts improved properties to polymers containing this novel form of 2-acrylamide-2-methylpropanesulfonic acid.

[0015] However, 2-acrylamido-2-methylpropanesulfonic acid, regardless of its form, remains a strong acid due to its sulfonic acid functional group and is highly corrosive to metals. Due to the powdery nature of 2-acrylamido-2-methylpropanesulfonic acid powder, there is also a risk of chemical burns if airborne particles come into contact with the skin or eyes, or are inhaled into the lungs during handling.

[0016] 2-Acrylamido-2-methylpropanesulfonic acid must be in aqueous form when used in polymerization. The aqueous phase may be used as is, i.e., in acid form, or after neutralization with an alkali metal, alkaline earth metal, or a molecule containing an unsubstituted or substituted amine functional group.

[0017] The shelf life of this aqueous solution is generally short. This is because self-polymerization occurs due to exposure to contaminants such as iron or its oxidized forms, which can result from corrosion of metal pipes or containers caused by temperature, UV light, or the acidic form of 2-acrylamido-2-methylpropanesulfonic acid. In addition, the temperature rise caused by the self-polymerization of 2-acrylamido-2-methylpropanesulfonic acid far exceeds the boiling point of water, increasing the pressure inside the container and potentially causing an explosion. Therefore, self-polymerization poses a certain risk to the safety of personnel and equipment. [Overview of the project] [Problems that the invention aims to solve]

[0018] The applicant has discovered a novel form of 2-acrylamido-2-methylpropanesulfonic acid, referred to as "crystalline form of potassium 2-acrylamido-2-methylpropanesulfonate," and hereafter also referred to as ATBS.K. This novel form avoids the neutralization step while simultaneously improving physicochemical and application properties (similar to the "hydrated crystal" form). It also reduces the risks of combustion, corrosion, and self-polymerization. Finally, the crystalline form of ATBS.K has a longer shelf life than aqueous solution of ATBS.K.

[0019] The use of the crystalline form of ATBS.K according to the present invention is consistent with environmental awareness principles and the impact that industry and humanity have on the planet. The novel form of the product means that it is safer for handlers to use and the energy load is reduced because a neutralization step is no longer required during the polymerization of ATBS and it is in powder form, which allows for the transport of more active raw material components (100% in powder compared to a maximum of 50% in solution). Furthermore, the improved shelf life of the product also means a reduction in waste caused by the increased amount of product required as a result of the performance degradation of overaged products. In addition, the improved performance of polymers obtained from the crystalline form of ATBS.K according to the present invention helps to reduce the amount of product required for the applications in which they are used, resulting in a reduction in overall water consumption and emissions of greenhouse gases such as CO2. [Means for solving the problem]

[0020] The object of the present invention is a specific form of 2-acrylamido-2-methylpropanesulfonic acid, which will hereafter be referred to as "crystalline form of potassium 2-acrylamido-2-methylpropanesulfonic acid salt".

[0021] The present invention also relates to a method for manufacturing the above-described embodiment of ATBS.K.

[0022] The present invention also relates to the use of the aforementioned forms of ATBS.K for producing water-soluble, water-swellable, or highly absorbent polymers.

[0023] The present invention also relates to a method for processing an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer at least partially obtained from the aforementioned form of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0024] The present invention also relates to a method for agglomerating an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer at least partially obtained from the aforementioned form of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0025] The present invention also relates to a method for enhanced recovery of hydrocarbons (petroleum and / or gas), comprising the following steps: a) A step of preparing an injection fluid containing at least one water-soluble polymer of 2-acrylamido-2-methylpropanesulfonic acid using water or brine; 2-acrylamido-2-methylpropanesulfonic acid is the embodiment of ATBS.K having, at least partially, a powder X-ray diffraction pattern before polymerization that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°; step; b) The step of injecting the injection fluid into the underground geological formation; c) A step of sweeping the underground geological formation using the injection fluid; d) A step of recovering the aqueous hydrocarbon mixture (a mixture containing water and hydrocarbons).

[0026] The present invention also relates to a fracturing fluid comprising at least one propane and at least one water-soluble polymer at least partially obtained from the aforementioned embodiment of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0027] The present invention also relates to a method for producing a fracturing fluid using at least one water-soluble polymer obtained at least partially from the above-mentioned form of ATBS.K having a powder X-ray diffraction pattern that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0028] The present invention also relates to a hydraulic fracturing method for unconventional underground reservoirs using a fracturing fluid according to the present invention.

[0029] The present invention also relates to a method for reducing friction using a fracturing fluid in hydraulic fracturing operations of unconventional underground reservoirs using a fracturing fluid according to the present invention.

[0030] The present invention also relates to the use of polymers obtained at least partially from the aforementioned forms of ATBS.K in well drilling or cementing; conformance, diversion; open, closed, or semi-closed circuit water treatment; fermentation broth treatment; sludge treatment; construction; paper or cardboard manufacturing; batteries; wood processing; hydraulic composition (concrete, cement, mortar, and aggregates); cosmetic preparation; detergent preparation; textile manufacturing; geothermal energy; diaper manufacturing; or agriculture.

[0031] Finally, the present invention also relates to the use of polymers obtained at least partially from the aforementioned forms of ATBS.K as coagulants, binders, viscosity reducers, thickeners, absorbents, water removers, filler retainers, dehydrators, conditioning agents, stabilizers, fixatives, film-forming agents, sizing agents, superplasticizers, clay inhibitors, or clay dispersants. [Modes for carrying out the invention]

[0032] The term "polymer" should be understood to mean a homopolymer or copolymer. The term "copolymer" should be understood to mean a polymer obtained from at least two different monomers. Therefore, it may be a copolymer of at least two monomers selected from hydrophilic anionic monomers, hydrophilic cationic monomers, hydrophilic nonionic monomers, hydrophilic zwitterionic monomers, hydrophobic monomers, and mixtures thereof.

[0033] The term "hydrophilic monomer" refers to an octanol-water partition coefficient K of 1 or less. ow It should be understood that this refers to a monomer having a partition coefficient K ow It is identified in a 1:1 volume ratio octanol-water mixture at 25°C and a pH of 6–8.

[0034] The terms "crystal" or "crystalline form" refer to a solid material in which its constituent elements (atoms, molecules, or ions, etc.) are arranged in a highly regular microscopic structure, forming a crystalline lattice that extends in all directions. Amorphous solids are not included.

[0035] The term "hydrophobic monomer" refers to an octanol-water partition coefficient greater than 1 K ow It should be understood that this refers to a monomer having a partition coefficient K ow It is identified in a 1:1 volume ratio octanol-water mixture at 25°C and a pH of 6–8.

[0036] Octanol-water partition coefficient K ow This represents the concentration (g / L) ratio of monomers between the octanol phase and the aqueous phase. This is defined as follows:

[0037]

number

[0038] According to the definition, a water-soluble polymer is defined as 10 g / L while stirring at 25°C. -1 This refers to a polymer that, when dissolved in water at a certain concentration, yields an aqueous solution.

[0039] "X and / or Y" should be understood to mean "X" or "Y" or "X and Y".

[0040] The present invention also includes all possible combinations of the various embodiments disclosed, whether they are preferred embodiments or given as examples. Furthermore, where ranges of values ​​are indicated, limit values ​​are included within those ranges. The disclosure also includes all combinations between the limit values ​​of these ranges. For example, the value range "1 to 20, preferably 5 to 15" means the ranges "1 to 5", "1 to 15", "5 to 20", and "15 to 20", as well as the disclosure of the values ​​1, 5, 15, and 20.

[0041] Crystal form of ATBS.K This invention relates to the crystalline form of potassium 2-acrylamido-2-methylpropanesulfonate (hereinafter referred to as ATBS.K) having a powder X-ray diffraction pattern with peaks at 2θ angles of 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; and 46.7°. The uncertainty of these peaks is generally on the order of ±0.1°.

[0042] X-ray crystallography, radiation crystallography, or X-ray diffraction is an analytical technique used to examine the structure of the crystalline substance at the atomic scale. This is based on the physical phenomenon of X-ray diffraction. A diffractometer using a copper X-ray source can be used.

[0043] Powders formed from a particular crystal phase always show diffraction peaks in the same direction. This diffraction pattern thus forms the true signature of the crystal phase. Therefore, it is possible to identify the nature of each crystal phase within a mixture or a pure product.

[0044] This signature is specific to each organic or inorganic compound and is in the form of a list of peaks located at the angle of 2θ (2-theta).

[0045] This technique is used for the characterization of different crystal forms, also called polymorphs, which may exist for a substance, particularly for the same chemical molecule.

[0046] Another aspect of the present invention relates to said crystal form of ATBS.K having a Fourier transform infrared spectrum including peaks at 3293 cm -1 , 3075 cm -1 , 3000 cm -1 , 2979 cm -1 , 1655 cm -1 , 1625 cm -1 , 1550 cm -1 , 1405 cm -1 , 1209 cm -1 , 1190 cm -1 , 1162 cm -1 , 1048 cm -1 , 979 cm -1 , 824 cm -1 , 803 cm -1 , 756 cm -1 , 633 cm -1 , 523 cm -1 . The uncertainty of these peaks is generally on the order of ±8 cm -1 .

[0047] Infrared measurement is performed, for example, with an 8cm single-reflection ATR polarizing accessory. -1 This is performed using a Perkin Elmer Spectrum 100 spectrometer with high precision, and is carried out by Fourier transform.

[0048] Fourier transform infrared spectroscopy is the analysis of vibrations emitted, absorbed, or scattered by molecules. This technique is highly sensitive to so-called short interactions (the influence of a unit mesh on bonding). In most cases, the Fourier transform infrared spectra of different crystal systems differ significantly. Therefore, the Fourier transform infrared spectra reflect the details of the crystal structure of chemical compounds.

[0049] Generally, and unless otherwise specified, X-ray diffraction patterns and infrared spectra are obtained at 20°C and an absolute pressure of 1 atmosphere (101,325 Pa).

[0050] Another aspect of the present invention relates to a crystalline form of ATBS.K having a minimum ignition energy of more than 500 mJ, preferably more than 1000 mJ.

[0051] Minimum ignition energy represents the minimum energy required to ignite a product (chemical compound). This energy can be electrical or thermal. Minimum ignition energy is essential information when considering the risk of explosion during product handling (transportation, storage, reaction, molding, etc.).

[0052] The minimum ignition energy depends on the properties (composition) of the powder and its polymer structure (particle size, crystal form, specific surface area).

[0053] For solids, this energy represents the minimum energy required for an electric spark that is likely to ignite cloud-like dust. The higher the minimum ignition energy, the lower the risk the solid poses when used, handled, or stored.

[0054] The minimum ignition energy is measured according to the NF EN 13821 standard.

[0055] Another aspect of the present invention relates to the crystalline form of ATBS.K that exhibits two thermal phenomena at 79.4°C and 207°C by differential scanning calorimetry. The uncertainty regarding the observation of these phenomena is generally on the order of 10°C (±10°C), and advantageously on the order of 5°C or less.

[0056] The aforementioned thermal phenomenon is measured by differential scanning calorimetry (DSC). This technique uses the measurement of the change in heat associated with the thermal denaturation of a compound when the compound is heated at a constant rate, for example, at a heating rate of 10°C / min.

[0057] Method for producing the above crystal form of ATBS.K The present invention also relates to a method for producing the crystalline form of ATBS.K, comprising at least the following sequential steps. 1) To form an aqueous solution or aqueous suspension SA2, mix 2-acrylamido-2-methylpropanesulfonic acid with an aqueous solution SA1 and at least one potassium salt base, preferably for at least 1 minute; 2) To form suspension S1, distill the aqueous solution or aqueous suspension SA2 at a pressure of 700 mbar or less; 3) Separating the suspension S1 into solid and liquid components, and isolating the crystals of the suspension S1 obtained at the end of step 2) in the form of composition C1. The resulting crystal is the crystal form of ATBS.K.

[0058] In step 1), "potassium salt base" should be understood to mean at least one inorganic potassium salt Brønsted base, such as potassium hydroxide, potassium carbonate, potassium bicarbonate, and mixtures thereof.

[0059] The temperature and mixing time in step 1) can vary, in particular, depending on the concentration of 2-acrylamido-2-methylpropanesulfonic acid, ATBS. Those skilled in the art will know how to adjust the temperature variation and mixing time to optimize the formation of the crystals.

[0060] The method for producing the crystalline form of ATBS.K can be carried out for any form of ATBS, such as needle-shaped or hydrated forms.

[0061] The above manufacturing method may be carried out with ATBS of any purity.

[0062] Therefore, the method may be carried out downstream of any type of method for producing ATBS. It may also be carried out on ATBS crystals that have already been obtained.

[0063] Step 1 of the method for producing the aforementioned crystalline form of ATBS.K): ATBS is produced by the manufacturing methods described above (acrylonitrile, fuming sulfuric acid, and isobutylene). 2-acrylamido-2-methylpropanesulfonic acid may be in the form of a fine powder, or it may be molded under controlled conditions by methods such as compression, granulation, or extrusion.

[0064] The addition of ATBS to the aqueous solution SA1 may be carried out before, after, or in parallel with the potassium salt base, preferably in parallel. Preferably, the aqueous solution SA1 is water.

[0065] The potassium salt base may be added as an aqueous solution. In this case, part or all of the aqueous solution of the potassium salt base may be aqueous solution SA1.

[0066] Advantageously, the concentration of potassium ATBS salt in the aqueous solution or aqueous suspension SA2 is 1% by weight to the saturation concentration, preferably 10% by weight to the saturation concentration, more preferably 20% by weight to the saturation concentration, more preferably 30% by weight to the saturation concentration, more preferably 40% by weight to the saturation concentration, and even more preferably 50% by weight to the saturation concentration, based on the weight of the aqueous solution or aqueous suspension SA2.

[0067] The ATBS and potassium salt base may be added all at once or in several stages. Adding them in several stages is preferable. Adding them all at once is preferable.

[0068] When added in several stages, the ATBS and the potassium salt base are added in portions.

[0069] When the ATBS and potassium salt base are added in portions, there is no limit to the number of portions, and advantageously there are at least two portions, preferably at least three portions.

[0070] There are no restrictions on the order in which the ATBS and potassium salt base are added. They may be added simultaneously (i.e., in parallel), one by one in sequence (first the ATBS, then the potassium salt base, or vice versa), or in a different manner (first portion of ATBS, then first portion of potassium salt base, then second portion of ATBS, then second portion of potassium salt base, etc.), and preferably they are added simultaneously.

[0071] If these are added one by one in sequence or by other means, the addition of the second compound (whether the ATBS or the potassium salt base) may begin before the addition of the first compound is completed.

[0072] The first portion F1 of ATBS advantageously corresponds to at least 1 mol%, preferably at least 5 mol%, more preferably at least 10 mol%, even more preferably at least 15 mol%, and even more preferably at least 20 mol% of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0073] The second portion F2 of ATBS advantageously corresponds to at least 1 mol%, preferably at least 5 mol%, more preferably at least 10 mol%, even more preferably at least 15 mol%, and even more preferably at least 20 mol% of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0074] The third portion F3 of ATBS advantageously corresponds to at least 1 mol%, preferably at least 5 mol%, more preferably at least 10 mol%, even more preferably at least 15 mol%, and even more preferably at least 20 mol% of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0075] In a particular embodiment, the method is carried out continuously, in which case the ATBS and the potassium salt base are added continuously.

[0076] The amount of ATBS in the aqueous solution or aqueous suspension SA2 is advantageously 10 to 90% by weight, preferably 20 to 85% by weight, and more preferably 30 to 80% by weight, relative to the total weight of the aqueous solution or aqueous suspension SA2.

[0077] The mixing step 1) (ATBS + potassium salt base) is advantageously carried out at a temperature of 0 to 90°C, preferably 5 to 60°C, more preferably 10 to 40°C, in order to obtain an aqueous solution or aqueous suspension SA2.

[0078] In certain embodiments, the aqueous solution or suspension SA2 may contain one or more organic solvents.

[0079] In some embodiments, the aqueous solution SA1 may contain one or more organic solvents.

[0080] The amount of organic solvent may vary depending on the temperature and the amount of ATBS or potassium salt base. This amount is not limited as long as it does not prevent obtaining the aforementioned crystalline form of ATBS.K. For those skilled in the art, the method for determining this limit is well known and is a normal procedure. Generally, aqueous solutions or aqueous suspensions SA2 contain more water (by volume) than organic solvent.

[0081] The one or more organic solvents are advantageously selected from the following compounds: - Organic acids, preferably carboxylic acids containing 1 to 8 carbon atoms; - Preferably amides containing 1 to 8 carbon atoms; - Alcohols that preferably contain 1 to 8 carbon atoms; - Preferably ketones containing 3 to 8 carbon atoms; - Ethers, which are advantageously composed of 2 to 8 carbon atoms; - Preferably esters containing 2 to 8 carbon atoms; - Alkanes, preferably containing 4 to 8 carbon atoms, more preferably 5 to 6 carbon atoms; - Preferably halogenated hydrocarbon compounds containing 1 to 8 carbon atoms; - Preferably nitriles containing 1 to 8 carbon atoms; or - These mixtures.

[0082] When an organic solvent is used in the present invention, the temperature can be adjusted so that the solvent-water mixture remains in a liquid state.

[0083] These compounds may be linear or branched. They may be saturated or contain unsaturated bonds. Unsaturated bonds correspond to double or triple bonds (e.g., C=C or C≡C).

[0084] The organic solvent is preferably selected from acrylonitrile, isopropanol, acetic acid, or a mixture thereof. The organic solvent is preferably acrylonitrile.

[0085] The organic solvent is generally a liquid at the temperature in which steps 2) and 3) are carried out. Furthermore, it is advantageously partially miscible with water, and preferably completely miscible with water.

[0086] The aforementioned organic solvent may, if necessary, be used to solubilize impurities or by-products present with the ATBS used to form the aqueous solution or aqueous suspension SA2. However, ATBS is not necessarily soluble in the aforementioned solvent.

[0087] In preferred embodiments of the present invention, the aqueous solution or aqueous suspension SA2 does not contain an organic solvent.

[0088] In a preferred embodiment of the present invention, the aqueous solution SA1 does not contain an organic solvent.

[0089] The time for mixing the aqueous solution SA1 and the ATBS is advantageously at least 1 minute, preferably 1 to 600 minutes, more preferably 5 to 400 minutes, and even more preferably 10 to 240 minutes.

[0090] The compounds in step 1) can be mixed using a variety of techniques. Examples, but not limited to, include stirrers, loop reactors, static mixers, microreactors, piston reactors, stirred filter dryers such as Nutsche, paddle mixers, double cone mixers, plowshare mixers, and disc mixers.

[0091] The pH in step 1) is advantageously controlled to be 6-14, preferably 8-14, more preferably 10-14, even more preferably 12-14, and even more preferably 13-14.

[0092] The amount of ATBS.K in the aqueous solution SA2 or aqueous suspension SA2 is advantageously 10 to 90% by weight, preferably 20 to 90% by weight, preferably 30 to 90% by weight, preferably 50 to 90% by weight, preferably 20 to 85% by weight, and more preferably 30 to 80% by weight, relative to the total weight of the aqueous solution or aqueous suspension SA2.

[0093] Step 2 of the method for producing the aforementioned crystalline form of ATBS.K): The distillation of the aqueous solution or aqueous suspension SA2 is carried out at a pressure of 700 mbar or less. This distillation is generally carried out in a vacuum distillation apparatus, which is typically an evaporator. Therefore, it is also referred to as "vacuum distillation" in this specification.

[0094] When an aqueous solution or aqueous suspension SA2 is distilled, typically by passing it through an evaporator, crystals of ATBS.K begin to form. Therefore, ATBS, at least one potassium salt base, and crystalline solid particles of ATBS.K coexist in the aqueous solution or aqueous suspension SA2.

[0095] The aqueous solution or aqueous suspension SA2 may be distilled using an evaporator. This may be a falling film evaporator, a rising film evaporator, a scraped thin film evaporator, a short-pass evaporator, a forced-circulation evaporator, a helical tube evaporator, or a flash evaporator. It may also be a continuous stirring reactor. Preferably, the distillation is carried out in a scraped thin film evaporator, a short-pass evaporator, or a forced-circulation evaporator. More preferably, the distillation is carried out in a scraped thin film evaporator.

[0096] Generally, an evaporator is a device that includes an inlet for the solution to be processed (aqueous solution or aqueous suspension SA2), an outlet for discharging the distilled solvent (water and any organic solvent), and an outlet for discharging the suspension S1.

[0097] The residence time of the aqueous solution or aqueous suspension SA2 in a distillation apparatus (preferably under reduced pressure), which is preferably an evaporator, i.e., the distillation time at a pressure of 700 mbar or less, is preferably between 1 second and 600 seconds, preferably between 3 seconds and 300 seconds, and more preferably between 30 seconds and 100 seconds. The residence time corresponds to the time required to carry out step 2), i.e., the time required to produce suspension S1 by distillation of the aqueous solution or aqueous suspension SA2. In other words, if an evaporator is used, it is the residence time of the ATBS (and / or the crystalline form of its potassium salt) between the inlet and outlet of the apparatus. This residence time varies depending on the amount of water (and any organic solvent), ATBS, and potassium salt base present in the aqueous solution or aqueous suspension SA2. To those skilled in the art, it is well known how to adjust this residence time for the purpose of obtaining the crystalline form of ATBS.K depending on the amount of components of the aqueous solution or aqueous suspension SA2.

[0098] The distillation may be carried out in a vertical or horizontal evaporator. Preferably, it is carried out in a vertical evaporator.

[0099] The aqueous solution or aqueous suspension SA2 can be circulated in a parallel or countercurrent flow with respect to the vapor generated by evaporation. Preferably, it is circulated in a countercurrent flow with respect to the vapor in the distillation apparatus. In other words, the aqueous solution or aqueous suspension SA2 is preferably introduced into the distillation apparatus, preferably into the evaporator, in a parallel or countercurrent flow with respect to the distilled solvent.

[0100] The aqueous solution or aqueous suspension SA2 may be circulated in one or more evaporators in series before obtaining the suspension S1. Preferably, it is circulated in a single evaporator.

[0101] The pressure during distillation is advantageously less than 1 to 700 mbar absolute pressure (1 mbar = 100 Pa). It is preferably less than 700 mbar absolute pressure, more preferably less than 600 mbar absolute pressure, more preferably less than 500 mbar absolute pressure, more preferably less than 400 mbar absolute pressure, more preferably less than 300 mbar absolute pressure, more preferably less than 200 mbar absolute pressure, more preferably less than 100 mbar absolute pressure, and even more preferably less than 50 mbar absolute pressure, and advantageously greater than 1 mbar absolute pressure. Absolute pressure corresponds to pressure relative to zero pressure (vacuum).

[0102] Generally, the pressure during distillation is preferably in the range of 10-700 mbar, preferably 20-700 mbar, preferably 40-700 mbar, more preferably 50-600 mbar, more preferably 50-500 mbar, more preferably 50-400 mbar, more preferably 50-300 mbar, more preferably 100-700 mbar, more preferably 200-700 mbar, more preferably 500-700 mbar, and more preferably 40-100 mbar.

[0103] In certain embodiments, step 2) includes step 2') (optionally performed) to assist in the evaporation of the solvent. Step 2') consists of raising the temperature of the aqueous solution or aqueous suspension SA2, in other words, the distillation according to step 2') is carried out under heating.

[0104] In some embodiments, in step 2), the aqueous solution or aqueous suspension SA2 is preferably heated to a temperature of 5°C to 95°C, preferably greater than 10°C to 60°C, and more preferably greater than 20°C to 40°C.

[0105] The heating during distillation can be carried out by various techniques. Examples, but not limited to, include heating with steam, heating with hot water, heating with electricity, heating by vapor compression, or heating using a heat pump. Therefore, the distillation apparatus may be a double-walled type in which a high-temperature heat-conducting fluid circulates between two walls.

[0106] The aqueous solution or aqueous suspension SA2 is preferably heated to a temperature of over 5°C to 95°C, preferably over 10°C to 60°C, and more preferably over 20°C to 40°C.

[0107] When the aqueous solution or aqueous suspension SA2 is heated, the temperature is preferably higher than the temperature in step 1).

[0108] The temperature of the aqueous solution or aqueous suspension SA2 is advantageously raised at a gradient of 0.1 to 10°C / hour, preferably 0.2 to 9°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0109] In some embodiments, the temperature of the aqueous solution or aqueous suspension SA2 is advantageously raised in a gradient of 10 to 150°C / hour, preferably 30 to 110°C / hour, more preferably 50 to 100°C / hour, and even more preferably 60 to 90°C / hour.

[0110] The temperature rise does not have to be constant throughout the entire process. For example, the aqueous solution or aqueous suspension SA2 may be heated at a rate of 5°C per hour for the first three hours, and then at a rate of 10°C per hour until the final temperature is reached.

[0111] According to another specific embodiment of the present invention, step 2) may include step 2'') (optionally performed) after or instead of step 2'), which helps to increase the productivity and profitability of the method of the present invention by promoting the crystallization of the potassium salt of the ATBS to the crystalline form. Step 2'') consists of lowering the temperature of the aqueous solution or aqueous suspension SA2.

[0112] The aqueous solution or aqueous suspension SA2 is advantageously cooled to a temperature of 5 to less than 95°C, preferably 10 to less than 60°C, more preferably 20 to less than 40°C, and even more preferably 10 to 40°C.

[0113] In some embodiments, step 2) further includes a cooling step.

[0114] The cooling step is advantageously carried out at a temperature of 5°C to 95°C, preferably more than 10°C to 60°C, and more preferably more than 10°C to 40°C.

[0115] In some embodiments, the temperature in the cooling step is reduced in a gradient of 0.1 to 8°C / hour, preferably 0.2 to 8°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0116] In some embodiments, the temperature of the cooling step is advantageously lower than the heating temperature of step 2) and / or step 1).

[0117] In some embodiments, the cooling step is performed on an aqueous solution or aqueous suspension SA2, and / or on a concentrated aqueous solution or aqueous suspension SA2, and / or on a suspension S1.

[0118] If the aqueous solution or aqueous suspension SA2 is cooled (step 2''), the temperature is advantageously lower than the temperature in step 2) and step 2') which is performed optionally.

[0119] According to a preferred embodiment, the temperature in step 2'') is the same as or lower than the temperature in step 1).

[0120] In some embodiments, no organic solvent or aqueous solution is added in step 2'' to obtain the ATBS.K crystals.

[0121] The temperature of the aqueous solution or aqueous suspension SA2 is advantageously decreased at a gradient of 0.1 to 8°C / hour, preferably 0.2 to 8°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0122] The rate of temperature decrease does not have to be constant throughout the entire process. For example, the aqueous solution or aqueous suspension SA2 may be cooled at a rate of 5°C per hour for the first 3 hours, and then at a rate of 8°C per hour until the final temperature is reached.

[0123] While the aqueous solution or aqueous suspension SA2 is being cooled, crystals of ATBS.K are formed, and suspension S1 is obtained.

[0124] In certain embodiments, crystals of previously obtained ATBS.K may be added during this step for the purpose of modifying the formation of suspension S1, a process referred to as crystal seeding, which allows for better control of the crystallization temperature, the particle size of the crystals, the particle size distribution, the purity of the final product, and possibly the yield. The crystals of potassium 2-acrylamido-2-methylpropanesulfonate added in this way have a powder X-ray diffraction pattern that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0125] According to a particular embodiment of the present invention, the solvent distilled in step 2) can be partially or entirely recycled to form the aqueous solution or aqueous suspension SA2 of step 1). In other words, the distilled solvent is advantageously at least partially recycled into the aqueous solution or aqueous suspension SA2.

[0126] According to another specific embodiment of the present invention, the distilled solvent may be partially or entirely recycled, with or without a pretreatment step, in step 4), which is optionally performed, to wash the ATBS.K crystals obtained after the solid-liquid separation of step 3).

[0127] The resulting suspension S1 advantageously contains 30 to 80% by weight, preferably 50 to 60% by weight, of the crystalline form of ATBS.K based on the total weight of the suspension S1.

[0128] In step 2), the pH is advantageously greater than 10, preferably greater than 11, more preferably greater than 12, and even more preferably 13-14.

[0129] Step 3 of the method for producing the aforementioned crystalline form of ATBS.K): The ATBS.K crystals contained in the suspension S1 obtained at the end of step 2) are isolated in the solid-liquid separation step and become composition C1.

[0130] The solid-liquid separation step can be carried out using a variety of techniques. Examples, but not limited to, include the use of a centrifuge, decanter, filter press, agitated filter, belt filter, disc filter, or rotary drum filter. The solid-liquid separation is preferably carried out using a centrifuge. The solid-liquid separation may also be carried out by gravity sedimentation.

[0131] Step 3) is advantageously carried out at a temperature of -20 to 40°C, preferably -5 to 30°C.

[0132] After step 3) of solid-liquid separation, the crystals of potassium 2-acrylamido-2-methylpropanesulfonate are preferably not dried.

[0133] The content of potassium 2-acrylamido-2-methylpropanesulfonate crystals in the isolated composition C1 is advantageously 40-99% by weight, preferably 60-99% by weight, more preferably 60-98% by weight, and even more preferably 80-99% by weight, relative to the weight of composition C1. The remainder of composition C1 may be water and / or solubilized ATBS.K, and optionally the potassium salt base introduced in step 1).

[0134] After the completion of step 3), the crystal is characterized as an ATBS.K crystal.

[0135] In a particular embodiment, all or part of the liquid phase obtained after the solid-liquid separation is used in the aqueous solution or aqueous suspension SA2 of step 1).

[0136] In step 4), the pH is advantageously controlled to 6-14, preferably 8-14, more preferably 10-14, even more preferably 12-14, and even more preferably 13-14.

[0137] Step 4 of the method for producing the aforementioned crystalline form of ATBS.K): In step 4), which may be performed as desired, the composition C1 containing the ATBS.K crystals obtained at the end of step 3) is washed with a washing solution.

[0138] The washing solution may be water, an aqueous solution of a potassium salt base (which may be saturated or unsaturated), or a solution of potassium 2-acrylamido-2-methylpropanesulfonate (preferably the crystalline form of ATBS.K) (which may be saturated or unsaturated), and is preferably a saturated solution of ATBS.K.

[0139] Examples of potassium salt solutions include potassium hydroxide, potassium carbonate, potassium bicarbonate, and mixtures thereof.

[0140] The cleaning solution may contain one or more organic solvents.

[0141] The amount of organic solvent may vary depending on the temperature and the amount of potassium 2-acrylamido-2-methylpropanesulfonate or potassium salt.

[0142] Advantageously, the cleaning solution does not contain organic solvents.

[0143] As already shown in Step 1), the organic solvent is advantageously selected from organic acids, amides, alcohols, ketones, ethers, esters, alkanes, halogenated hydrocarbon compounds, nitriles, or mixtures thereof. The organic solvent is preferably selected from acrylonitrile, isopropanol, acetic acid, or mixtures thereof. More preferably, the organic solvent is acrylonitrile.

[0144] In a particular embodiment, the composition C1 obtained at the end of step 3) is cleaned by spraying a cleaning solution onto the composition C1.

[0145] In a particular embodiment, the composition C1 obtained at the end of step 3) is washed by suspending the composition C1 in the washing solution.

[0146] The weight ratio of the cleaning aqueous solution to composition C1 obtained at the end of step 3) is advantageously 0.05:1 to 10:1, more preferably 0.1:1 to 5:1.

[0147] This washing step is advantageously carried out at a temperature of -5 to 40°C, preferably 0 to 30°C. Those skilled in the art will know how to adjust the temperature so as not to solubilize the ATBS.K crystals.

[0148] The ATBS.K crystals obtained at the end of step 4), which is performed as desired, can be isolated from the washing solution in the form of composition C2 by a solid-liquid separation step.

[0149] The solid-liquid separation step can be carried out using a variety of techniques. Examples, but not limited to, include the use of vertical or horizontal centrifuges, decanters, filter presses, belt filters, disc filters, push filters, or rotary drum filters. The solid-liquid separation may also be carried out by gravity sedimentation.

[0150] In certain embodiments, all or part of the recovered washing solution may be reused in step 4), with or without the pretreatment step.

[0151] In certain embodiments, all or part of the recovered washing solution may be used in the aqueous solution or aqueous suspension SA2 of step 1), with or without the pretreatment step.

[0152] The pH of the washing solution in step 5 is advantageously controlled to 6-14, preferably 8-14.

[0153] Step 5 of the method for producing the aforementioned crystalline form of ATBS.K): In step 5), which may be performed as desired, composition C1 obtained at the end of step 3) or composition C2 obtained at the end of step 4) is dried.

[0154] The drying step can be carried out using a variety of techniques. Examples, but not limited to, include the use of all convection, conduction, or radiation drying techniques (fluidized bed dryers, through-bed dryers, belt conveyor drying, microwaves, heated agitated filters, high-frequency radiation, infrared radiation, and spraying).

[0155] The drying operation may be carried out under atmospheric pressure, or under reduced pressure.

[0156] The drying step may be carried out discontinuously (batch drying) or continuously.

[0157] Other steps in the method for producing the aforementioned crystalline form of ATBS.K: In the process of the above-mentioned manufacturing method, i.e., in steps 1) to 5), and notwithstanding the foregoing steps, at least one polymerization inhibitor may be introduced for the purpose of preventing possible polymerization of ATBS or a salt thereof. This inhibitor may be selected, not limited to, hydroquinone, paramethoxyphenol, phenothiazine, 2,2,6,6-tetramethyl(piperidine-1-yl)oxyl, 4-hydroxy-2,2,6,6-tetramethyl(piperidine-1-yl)oxyl, phenylenediamine derivatives, or mixtures thereof.

[0158] The inhibitor is preferably paramethoxyphenol or 4-hydroxy-2,2,6,6-tetramethyl(piperidine-1-yl)oxyl.

[0159] The amount of the inhibitor introduced is preferably 0.001% to 5% by weight, more preferably 0.01% to 1% by weight, relative to the amount of ATBS introduced in step 1).

[0160] The inhibitor may be introduced in one or more of the steps of the method. Preferably, the additional amount of the inhibitor is introduced in step 1). More preferably, the inhibitor is a portion of the aqueous solution SA1 or aqueous solution or aqueous suspension SA2 introduced in step 1).

[0161] The above manufacturing method (steps 1) to 5)) may be carried out continuously or discontinuously (batch manufacturing).

[0162] polymer The present invention also relates to the use of a novel crystalline form of ATBS.K for the production of polymers.

[0163] Accordingly, the present invention also relates to polymers obtained at least from ATBS that are at least partially present in the crystalline form of ATBS.K having a powder X-ray diffraction pattern with peaks at 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7° (±0.1°) for 2θ angles.

[0164] The polymer is obtained at least in part from the crystalline form of ATBS.K, and, advantageously, from at least one other monomer selected from hydrophilic nonionic monomers, hydrophilic anionic monomers (different from the crystalline form of ATBS.K), hydrophilic cationic monomers, hydrophilic zwitterionic monomers, and hydrophobic monomers.

[0165] Therefore, the polymer may be a polymer or homopolymer of multiple different monomers.

[0166] Advantageously, at least 10 mol%, preferably at least 30 mol%, more preferably at least 50 mol%, and even more preferably at least 70 mol% of the ATBS used to obtain the polymer is the crystalline form of ATBS.K. Even more preferably, 100 mol% of the ATBS is the crystalline form of ATBS.K.

[0167] The polymer preferably contains 1 to 100 mol%, more preferably 2 to 60 mol%, more preferably 3 to 25 mol%, and preferably at least 10 mol%, more preferably at least 30 mol%, more preferably at least 50 mol%, and even more preferably at least 70 mol%, of the crystalline form of ATBS.K. Even more preferably, 100 mol% of the ATBS used is the crystalline form of ATBS.K.

[0168] In certain embodiments, the polymer advantageously comprises at least 10 mol%, preferably at least 20 mol%, more preferably at least 30 mol%, more preferably at least 40 mol%, more preferably at least 50 mol%, more preferably at least 60 mol%, more preferably at least 70 mol%, more preferably at least 80 mol%, and more preferably at least 90 mol%, and advantageously at least 10 mol%, preferably at least 30 mol%, more preferably at least 50 mol%, and even more preferably at least 70 mol%, the crystalline form of ATBS.K, and even more preferably 100% of the ATBS used is the crystalline form of ATBS.K.

[0169] In a particular embodiment, the polymer is a homopolymer of ATBS, and advantageously, at least 10 mol%, preferably at least 30 mol%, more preferably at least 50 mol%, and even more preferably at least 70 mol%, is the crystalline form of ATBS.K, and even more preferably, 100% of the ATBS used is the crystalline form of ATBS.K.

[0170] In a particular embodiment, the polymer is a homopolymer of the crystalline form of ATBS.K.

[0171] In a particular embodiment, the polymer is a polymer obtained from ATBS (at least 10 mol% thereof is advantageously the crystalline form of ATBS.K) and at least one nonionic monomer.

[0172] Polymer composition The polymer is obtained from the crystalline form of ATBS.K, and, advantageously, from at least one other monomer that can be selected from hydrophilic nonionic monomers, and / or hydrophilic anionic monomers, and / or hydrophilic cationic monomers, and / or hydrophilic zwitterionic monomers, and / or hydrophobic monomers, and mixtures thereof. The polymer may be a polymer or homopolymer of a plurality of different monomers.

[0173] Advantageously, the hydrophilic nonionic monomers that can be used in the present invention include, in particular, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide (e.g., N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamide, alkoxylated acrylates, N-vinylpyrrolidone, N-methylol(meth)acrylamide, N-vinylcaprolactam, N-vinylformamide (NVF), N-vinylacetamide, N-vinylimidazole, N-vinyl The water-soluble vinyl monomers are selected from the group including cucinimide, acryloylmorpholine (ACMO), glycidyl methacrylate, vinyl acetate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, isoprenol and its alkoxylated derivatives, hydroxyethyl (meth)acrylate and its alkoxylated derivatives, hydroxypropyl acrylate and its alkoxylated derivatives, and mixtures thereof. Among the nonionic monomers, the alkyl group is preferably C1-C5, and more preferably C1-C3. The alkyl group is preferably a linear alkyl group. Preferably, the hydrophilic nonionic monomer is acrylamide.

[0174] The polymer preferably comprises 0 to 99 mol%, preferably 40 to 98 mol%, and more preferably 75 to 97 mol%, of hydrophilic nonionic monomers.

[0175] Advantageously, apart from the crystalline form of ATBS.K, the hydrophilic anionic monomers that can be used in the present invention can be selected from a large group. These monomers may have a vinyl functional group (preferably acrylic, malee, fuma, malon, itacone, or allyl) and may contain a carboxylic acid group, a phosphonic acid group, a phosphoric acid group, a sulfate group, or a sulfonic acid group, or other anionic charged groups. Examples of suitable monomers include acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; C1-C3 hemiesters of itaconic acid; acryloyl chloride; crotonic acid; maleic acid; fumaric acid; 3-acrylamido-3-methylbutanoic acid; and strong acid monomers having a sulfonic acid functional group or a phosphonic acid functional group, such as vinyl sulfonic acid, vinyl phosphonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, sulfopropyl Examples include acrylates, allylphosphonic acid, ethylene glycol methacrylate phosphate, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), 2-acrylamido-2-methylpropanedisulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, diethylallylphosphonate, carboxyethyl acrylate, etc.; water-soluble salts of these monomers, such as alkali metal salts (different from the crystalline form of ATBS.K), alkaline earth metal salts, or ammonium salts; and mixtures thereof. Preferably, the hydrophilic anionic monomer is acrylic acid and / or a salt thereof.

[0176] The polymer advantageously contains 0 to 99 mol%, preferably 5 to 70 mol%, and more preferably 10 to 50 mol%, of hydrophilic anionic monomers (different from the crystalline form of ATBS.K). Above 5 mol%, these proportions also include monomers of the crystalline form of ATBS.K according to the present invention.

[0177] In certain embodiments, the hydrophilic anionic monomer, which is different from the crystalline form of ATBS.K, may be salinated.

[0178] According to the present inventors, chlorination refers to the -R of the anionic monomer. a The proton of at least one acidic functional group of the (=O)-OH type (in this case R represents P, S, or C) is replaced with a metal cation or an ammonium cation, -R a This means forming a (=O)-OX type salt (where X is a metal cation or an organic cation). In other words, the non-chlorinated form is the acidic form of the monomer, for example, in the case of a carboxylic acid functional group, R b -C(=O)-OH corresponds to the above monomer, while the chloride form of the monomer is R b -C(=O)-O - X + This corresponds to the form, X + This corresponds to an alkali cation or an organic cation. The chlorination of the acidic functional group of the branched-chain water-soluble polymer may be partial or whole. The chlorination form is advantageously equivalent to a salt of an alkali metal (Li, Na, K, etc.), an alkaline earth metal (Ca, Mg, etc.), or an ammonium (e.g., ammonium ion or tertiary ammonium). A preferred salt is a potassium salt.

[0179] The aforementioned chlorination may be carried out before, during, or after polymerization.

[0180] In certain embodiments, the polymer advantageously comprises 1 to 100 mol%, preferably 50 to 100 mol%, of hydrophilic anionic monomers in chloride form. These proportions include monomers in crystalline form of ATBS.K according to the present invention.

[0181] Advantageously, the hydrophilic cationic monomers that can be used in the present invention are selected from monomers derived from vinyl-type units (preferably acrylamide, acrylic, allyl, or malein), and these monomers have a phosphonium or quaternary ammonium functional group. Particularly, and without limitation, these may be mentioned: diallyldialkylammonium salts such as diallyldimethylammonium chloride (DADMAC); acidified or quaternary salts of dialkylaminoalkyl (meth)acrylamide, e.g., methacrylamide-propyltrimethylammonium chloride (MAPTAC), acrylamide-propyltrimethylammonium chloride (APTAC); acidified or quaternary salts of dialkylaminoalkyl acrylates such as quaternary or chlorinated dimethylaminoethyl acrylate (DMAEA); quaternary or chlorinated dimethylaminoethyl acrylates These include acidified or quaternized salts of dialkylaminoalkyl methacrylates such as noethyl methacrylate (DMAEMA); acidified or quaternized salts of N,N-dimethylallylamine; acidified or quaternized salts of diallylmethylamine; acidified or quaternized salts of diallylamine; vinylamines obtained by hydrolysis (basic or acidic) of an amide group -N(R2)-CO-R1 (where R1 and R2 are independently hydrogen atoms or alkylated chains having 1 to 6 carbon atoms), such as vinylamines obtained from the hydrolysis of vinylformamide; vinylamines obtained by Hoffmann decomposition; and mixtures thereof. Advantageously, the alkyl group is C1 to C7, preferably C1 to C3, and may be linear, cyclic, saturated, or unsaturated. Preferably, it is quaternized dimethylaminoethyl acrylate.

[0182] Methods for preparing quaternized monomers, such as using an RX-type quaternizing agent in which R is an alkyl group and X is a halogen or sulfate, are well known to those skilled in the art.

[0183] The term "quaternary amine" refers to a molecule that can alkylate a tertiary amine.

[0184] The quaternizing agent may be selected from dialkyl sulfates containing 1 to 6 carbon atoms or alkyl halides containing 1 to 6 carbon atoms. Preferably, the quaternizing agent is selected from methyl chloride, benzyl chloride, dimethyl sulfate, or diethyl sulfate. In addition, the present invention also includes DADMAC, APTAC, and MAPTAC monomers in which the counterion is a sulfate ion, fluoride ion, bromide ion, or iodide ion instead of a chloride ion.

[0185] The polymer preferably contains 0 to 20 mol%, more preferably 0 to 6 mol%, of hydrophilic cationic monomers.

[0186] Advantageously, the hydrophilic zwitterionic monomer may be a derivative of a vinyl-type unit (preferably acrylamide, acrylic, allyl, or malein), the monomer having a quaternary amine or ammonium functional group and a carboxylic acid (or carboxylate), sulfonic acid (or sulfonate), or phosphoric acid (or phosphate) functional group. In particular, and without limitation, may be mentioned, 2-((2-(acryloyloxy)ethyl)dimethylammonio)dimethylammonio)ethane-1-sulfonate, 3-((2-(acryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, [2-(acryloyloxy)ethyl](dimethylammonio)acetate Dimethylaminoethyl acrylate derivatives such as 2-((2-(methacryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(methacryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, and [2-(methacryloyloxy)ethyl](dimethylammonio)acetate. Dimethylaminopropylacrylamide derivatives such as noethyl methacrylate derivatives, 2-((3-acrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-acrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-acrylamidopropyl)dimethylammonio)butane-1-sulfonate, [3-(acryloyloxy)propyl](dimethylammonio)acetate, 2-((3-methacrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-methacrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-methacrylamidopropyl)dimethylammonio)butane-1-sulfonate, and [3-(methacryloyloxy)propyl](dimethylammonio)acetate, as well as mixtures thereof.

[0187] Other hydrophilic zwitterionic monomers, particularly those described by the applicant in the document of International Publication No. 2021 / 123599, may be used.

[0188] The polymer preferably contains 0 to 20 mol%, more preferably 0 to 10 mol% of hydrophilic zwitterionic monomer.

[0189] Partition coefficient K ow Hydrophobic monomers with a partition coefficient K greater than 1 can also be used in the production of the polymers according to the invention. These are preferably selected from the following list: (i) C4-C 30 alkyl chain, or (ii) arylalkyl (C4-C 30 alkyl, C4-C 30 aryl) chain, or (iii) propoxylated chain, or (iv) ethoxylated chain, or (v) (meth)acrylate ester with an ethoxylated and propoxylated chain; alkylaryl sulfonate (C4-C 30 alkyl, C4-C 30 aryl); (i) C4-C 30 alkyl chain, or (ii) arylalkyl (C4-C 30 alkyl, C4-C 30 aryl) chain, or (iii) propoxylated chain, or (iv) ethoxylated chain, or (v) monosubstituted or disubstituted (meth)acrylamide amide having an ethoxylated and propoxylated chain; anionic or cationic monomer derivatives of (meth)acrylamide or (meth)acrylic acid having a hydrophobic chain; vinylpyridine, and mixtures thereof. The hydrophobic monomer may contain a halogen atom, such as chlorine.

[0190] Among these hydrophobic monomers: - The alkyl group is preferably C4-C 20 and more preferably C4-C8. C6-C 20 alkyl is preferably linear, while C4-C5 alkyl is preferably branched. - The arylalkyl group is preferably C7-C 25and more preferably C7 - C 15 is. - The ethoxylated chain preferably contains 1 to 200, more preferably 6 to 100, and even more preferably 10 to 40 —CH2-CH2-O— groups. - The propoxylated chain preferably contains 1 to 50, more preferably 1 to 20 —CH2-CH2-CH2-O— groups.

[0191] Preferred hydrophobic monomers belonging to these classes are, for example, as follows: - n-hexyl (meth) acrylate, n-octyl (meth) acrylate, octyl (meth) acrylamide, lauryl (meth) acrylate, lauryl (meth) acrylamide, myristyl (meth) acrylate, myristyl (meth) acrylamide, pentadecyl (meth) acrylate, pentadecyl (meth) acrylamide, cetyl (meth) acrylate, cetyl (meth) acrylamide, oleyl (meth) acrylate, oleyl (meth) acrylamide, erucyl (meth) acrylate, erucyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, 2-ethylhexyl acrylate, C4 - C 22 hemiesters of itaconic acid, C4 - C 22 acidified or quaternized salts of dialkylaminoalkyl (meth) acrylates, C4 - C 22 acidified or quaternized salts of dialkylaminoalkyl (meth) acrylamides, vinylpyridine, acrylamide undecanoic acid, and mixtures thereof, - Cationic allyl derivatives of formula (I) or (II):

[0192]

Chemical formula

[0193] Where: R: independently an alkyl chain containing 1 to 4 carbons; R1: an alkyl or arylalkyl chain containing 8 to 30 carbons; X: A halide selected from the group consisting of bromides, chlorides, iodides, and fluorides, and any negatively charged counterion; Furthermore, preferably, a (meth)acryloyl-type hydrophobic cationic derivative corresponding to formula (III):

[0194] [ka]

[0195] During the ceremony: - A represents O or N-R5 (preferably, A represents N-R5). - R2, R3, R4, R5, R6, R7: Independently, alkyl chains containing hydrogen or 1 to 4 carbon atoms. - Q: An alkyl chain containing 1 to 20 carbon atoms, - R8: Alkyl or arylalkyl chain containing 8 to 30 carbon atoms, - X: A halide selected from the group consisting of bromides, chlorides, iodides, and fluorides, and any negatively charged counterion.

[0196] If the polymer is water-soluble, it is advantageous that it contains less than 5 mol% of hydrophobic monomers, the amount of which is adjusted so that the polymer maintains its water solubility.

[0197] In the present invention, monomers having fluorescent functional groups may be used. Monomers having fluorescent functional groups can be detected by any suitable method, such as fluorescence photometry using a fixed-wavelength fluorometer. Generally, monomers having fluorescent functional groups are detected at excitation and emission maxima, which can be identified using a scanning fluorometer.

[0198] Monomers having fluorescent functional groups are selected from, for example, the following monomers: sodium or potassium styrenesulfonate, styrenesulfonic acid, vinylimidazole and its derivatives, 9-vinylanthracene and its derivatives, N-9-xanthenylacrylamide and its derivatives, allyldibenzosverenol and its derivatives, cinconicin and its derivatives, quininone and its derivatives, cinconinone and its derivatives, N,N-dimethyl-N-[3-[N'-(4-methoxynaphthalimide)]]propyl-N-(2-hydroxy-3-allyloxy)propylammonium hydroxide, and mixtures thereof.

[0199] When functionalized with allyl, vinyl, or acrylic double bonds, other fluorescent compounds can be used, such as pyranine and its derivatives, coumarin and its derivatives, quinolaxin and its derivatives, pinacyanol and its derivatives, xanthohydrol and its derivatives, dabusil and its derivatives, 3-hydroxy-2-methylene-3-(1-naphthyl)propionic acid and its derivatives, rhodamine and its derivatives, N-dibenzoberylacrylamide and its derivatives, naphthalene derivatives, fluorescein and its derivatives, pyrene and its derivatives, carbostyryl and its derivatives, pyrazoline and its derivatives, and mixtures thereof.

[0200] In a preferred embodiment, the polymer does not contain monomers having fluorescent functional groups.

[0201] In certain embodiments, the polymer may comprise at least one cyclic monomer having a hydrolyzable functional group. Advantageously, the cyclic monomer having a hydrolyzable functional group, or the cyclic monomer itself, may be selected from cyclic ketene acetals, thionolactones, and mixtures thereof.

[0202] The cyclic ketene acetal is preferably selected from 2-methylene-1,3-dioxepane (MDO), 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), 2-methylene-4-phenyl-1,3-dioxolane (MPDL), 2-methylene-1,3,6-trioxocane (MTC), and mixtures thereof. Preferably, it is 2-methylene-1,3-dioxepane (MDO).

[0203] The thionolactone is preferably selected from dibenzo[c,e]oxepin(7H)-5-thione (DOT), ε-thionocaprolactone, 3,3-dimethyl-2,3-dihydro-5H-benzo[e][1,4]dioxepin-5-thione (DBT), and mixtures thereof. Preferably, it is 3,3-dimethyl-2,3-dihydro-5H-benzo[e][1,4]dioxepin-5-thione.

[0204] In certain embodiments, the polymer may include at least one group having a LCST.

[0205] According to the general knowledge of those skilled in the art, a group having a LCST corresponds to a group whose water solubility at a given concentration is modified above a certain temperature and depending on the salt concentration. This is a group having a heating transition temperature that determines the lack of affinity with the solvent. The lack of affinity with the solvent results in opacification or loss of transparency, which may be due to precipitation, aggregation, gelation, or thickening of the medium. The minimum transition temperature is known as the LCST (lower critical solution temperature). At each concentration of the group having a LCST, a heating transition temperature is observed. It is higher than the LCST, which is the minimum point on the curve. Below this temperature, the polymer is soluble in water, and above this temperature, the polymer loses its solubility in water.

[0206] In certain embodiments, the polymer may include at least one group having a UCST.

[0207] According to the general knowledge of those skilled in the art, a group having UCST corresponds to a group whose water solubility at a given concentration is modified below a certain temperature and depending on the salt concentration. This is a group that has a cooling transition temperature that determines the lack of affinity with the solvent. The lack of affinity with the solvent results in opacity or loss of transparency, which can be due to precipitation, aggregation, gelation, or viscosity increase of the medium. The highest transition temperature is known as UCST (upper critical solution temperature). At each concentration of a group having UCST, a cooling transition temperature is observed. It is lower than the UCST, which is the maximum point on the curve. Above this temperature, the polymer is soluble in water, and below this temperature, the polymer loses its solubility in water.

[0208] The amounts of different monomers are adjusted by those skilled in the art so as not to exceed 100 mol% when producing the polymer according to the present invention.

[0209] According to the present invention, the polymer may have a linear, branched, crosslinked, star-shaped, or comb-shaped structure. This structure can be obtained, according to the general knowledge of those skilled in the art, for example, by selecting initiators, transfer agents, polymerization techniques such as reversible addition-cleavage chain transfer (RAFT) polymerization, nitroxide-mediated polymerization (NMP), or atom transfer radical polymerization (ATRP), incorporating structural monomers, or selecting concentrations.

[0210] The polymer may be further structured with a branching agent. A structured polymer is a non-linear polymer having side chains such that, when dissolved in water, the polymer exhibits a high degree of entanglement, resulting in very high low-gradient viscosities.

[0211] The aforementioned branching agent is advantageous in that, - A structural agent may be selected from the group including polyethylene unsaturated monomers (having at least two unsaturated functional groups), vinyl functional groups, particularly allyl functional groups or acrylic functional groups, for example, methylenebisacrylamide (MBA), triallylamine, or tetraallylammonium chloride, or 1,2-dihydroxyethylenebis-(N-acrylamide). - A monomer having at least two epoxy functional groups - A monomer having at least one unsaturated and one epoxy functional group, - Transport agents such as polyperoxides, polyazoids, and polymercaptant polymers, as well as macroinitiators such as polyols. - Functionalized polysaccharides, - Water-soluble metal composite composed of the following: * Examples include, but are not limited to, metals with a valency greater than 3, such as aluminum, boron, zirconium, or titanium, and * Ligands having a hydroxyl functional group, Selected from.

[0212] The amount of branching agent in the polymer is advantageously less than 40,000 ppm by weight, preferably less than 10,000 ppm by weight, and more preferably less than 5,000 ppm by weight, relative to the total weight of the monomers of the polymer.

[0213] In a particular embodiment, the amount of branching agent is equal to at least 0.1 ppm by weight, preferably at least 1 ppm by weight, more preferably at least 10 ppm by weight, more preferably at least 100 ppm by weight, and even more preferably at least 1000 ppm by weight, relative to the total weight of the polymer monomer.

[0214] If the polymer is water-soluble and contains a branching agent, the polymer may remain water-soluble. Those skilled in the art will know how to adjust the amount of branching agent, and possibly the amount of transfer agent, required to obtain this result.

[0215] In a preferred embodiment, the polymer is a water-soluble polymer that does not contain a branching agent.

[0216] In certain embodiments, the polymer may include a transfer agent.

[0217] The aforementioned transport agent is preferably methanol; isopropyl alcohol; sodium hypophosphate; calcium hypophosphate; magnesium hypophosphate; potassium hypophosphate; ammonium hypophosphate; formic acid; sodium formate; calcium formate; magnesium formate; potassium formate; ammonium formate; 2-mercaptoethanol; 3-mercaptopropanol; dithiopropylene glycol; thioglycerol; thioglycolic acid; thiohydroacrylic acid; thiolactic acid; thiomalic acid; cysteine; aminoethanethiol; thioglycolate; allyl phosphite; allyl mercaptans such as n-dodecyl mercaptan; sodium methallysulfonate; calcium methallylsulfonate; magnesium methallylsulfonate; potassium methallylsulfonate; ammonium methallylsulfonate; trialkyl(C) 12 ~C 15 ) Selected from alkyl phosphites such as phosphites, dioleylhydrogen phosphites, and dibutyl phosphites; dialkyldithiophosphates such as dioctylphosphonates; tertiary nonyl mercaptans; 2-ethylhexyl thioglycolates; n-octyl mercaptans; n-dodecyl mercaptans; tertiary dodecyl mercaptans; iso-octyl thioglycolates; 2-ethylhexyl thioglycolates; 2-ethylhexyl mercaptoacetates; polythiols; and mixtures thereof. Preferably, sodium hypophosphate or sodium formate.

[0218] The amount of the transfer agent in the polymer is advantageously 0 to 100,000 ppm by weight, preferably 0 to 10,000 ppm by weight, more preferably 0 to 1,000 ppm by weight, and even more preferably 0 to 100 ppm by weight, relative to the total weight of the monomers of the polymer. If present, the transfer agent corresponds to at least 0.1 ppm by weight, preferably at least 1 ppm by weight, relative to the total weight of the monomers of the polymer.

[0219] In certain embodiments, the polymer does not contain a transfer agent.

[0220] Generally speaking, the polymer does not require the development of any specific polymerization method. In fact, it may be obtained using any polymerization technique well known to those skilled in the art. These include solution polymerization; gel polymerization; precipitation polymerization; emulsion polymerization (aqueous or reversed phase); suspension polymerization; reactive extrusion polymerization; water-in-water polymerization; or micelle polymerization.

[0221] The polymerization described above is generally radical polymerization, preferably by reverse-phase emulsion polymerization or gel polymerization. Radical polymerization includes free radical polymerization using UV initiators, azo initiators, redox initiators, or thermal initiators, as well as controlled radical polymerization (CRP) or matrix polymerization techniques.

[0222] Controlled radical polymerization technologies are not limited to, but include iodine transfer polymerization (ITP), nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP), reversible addition-cleavage chain transfer (RAFT) polymerization including MADIX (Macromolecular Design by Interchange of Xanthates) technology, various modifications of organometallic radical polymerization (OMRP), and organic heteroatom-mediated radical polymerization (OHRP).

[0223] The polymer may be partially or completely hydrolyzed after treatment.

[0224] The post-hydrolysis treatment is a hydrolysis reaction of the polymer after the polymer has been formed by the polymerization of the monomers. This step involves reacting the hydrolyzable functional groups of the monomer, preferably nonionic functional groups, and more preferably amide or ester functional groups, with a hydrolyzing agent. This hydrolyzing agent may be, for example, an enzyme, an ion exchange resin, or a Brønsted acid (e.g., a hydrohalic acid) or a Brønsted base (e.g., an alkali metal hydroxide or alkaline earth metal hydroxide). Preferably, the hydrolyzing agent is a Brønsted base. In the process of this post-hydrolysis treatment of the polymer, the number of carboxylic acid functional groups increases. In fact, carboxylate groups are generated by the reaction of the base with the amide or ester functional groups present in the polymer.

[0225] If the production of the polymer includes a drying step such as spray drying, drum drying, microwave drying, or drying in a fluidized bed, the polymer may be in the form of a liquid, gel, or solid.

[0226] The polymer advantageously has a molecular weight of at least 500,000 g / mol, preferably 500,000 to 40 million g / mol, and more preferably 5 million to 30 million g / mol. The molecular weight is determined by the weight-average molecular weight. The polymer may also have a molecular weight of 5,000 to 100,000 g / mol or 100,000 to 500,000 g / mol.

[0227] The molecular weight is determined by the intrinsic viscosity of the polymer. The intrinsic viscosity may be measured by methods known to those skilled in the art, and can be calculated from reduced viscosity values ​​for different polymer concentrations by a graphing method, which involves plotting the reduced viscosity value (y-axis) against the concentration (x-axis) and extrapolating the curve to zero concentration. The intrinsic viscosity value is plotted on the y-axis, or the least squares method is used. Subsequently, the molecular weight can be determined using the Mark-Houwink formula: [η]=KM α In the formula, [η] represents the intrinsic viscosity of the polymer as determined by the solution viscosity method. K represents the experimental constant. M represents the molecular weight of the polymer. α represents the Mark-Houwink coefficient. K and α vary depending on the specific polymer-solvent system.

[0228] Polymer properties If the polymer is water-soluble, it is advantageous to have a filter ratio (FR) of less than 1.5, preferably less than 1.3, and more preferably less than 1.1.

[0229] In this document, the term "filter ratio" is used to refer to a test used to determine the performance of a polymer solution under conditions similar to the permeability of sediment, and consists of measuring the time it takes for a given volume / concentration of solution to pass through a filter. FR generally compares the filterability of the polymer solution in two consecutive equal volumes, indicating the tendency of the solution to clog the filter. A lower FR indicates better performance.

[0230] The test used to determine the FR involves measuring the time it takes for a given volume of 1000 ppm (by weight) of polymer solution to pass through a filter. The solution is contained in a cell pressurized to 2 bar, and the filter has a diameter of 47 mm and a specified pore size. The FR is typically measured using filters with pore sizes of 1.2 μm, 3 μm, 5 μm, or 10 μm.

[0231] 100ml(t 100ml ), 200ml (t 200ml ), and 300ml (t 300ml The time required to obtain the filtrate is measured, and then FR is defined as follows:

[0232]

number

[0233] Time is measured to the nearest 0.1 seconds, rounded to the nearest whole number.

[0234] Therefore, FR represents the ability of the polymer solution to block the filter in two consecutive equivolumes.

[0235] The polymer used in the present invention has improved resistance to chemical and thermal decomposition compared to polymers of equivalent molecular weight obtained from ATBS that are not the crystalline form of ATBS.K.

[0236] The test used to determine resistance to chemical degradation involves preparing a polymer solution of a given concentration in a given brine under aerobic conditions and contacting it with a chemical contaminant such as iron or hydrogen sulfide. The viscosity of the polymer solution is measured before and after 24 hours of exposure to the contaminant. Viscosity measurements are performed under the same temperature and shear gradient conditions.

[0237] Tests used to determine resistance to physical degradation include preparing a polymer solution of a given concentration in brine of a given composition under anaerobic conditions (e.g., using an inert glove box inert with nitrogen), and aging it for a predetermined time in a stainless steel cell set to a given temperature. The stainless steel cell is then cooled to room temperature, and the viscosity of the polymer solution contained within the cell is measured and compared to its initial value. All handling of the stainless steel cell is carried out inside the glove box to avoid exposure to oxygen. The stainless steel cell is sealed to prevent oxygen from entering the solution during thermal aging. Viscosity measurements before and after aging are performed inside the glove box under the same temperature and velocity gradient conditions.

[0238] Resistance to chemical and thermal decomposition is quantified by a viscosity reduction value expressed as a percentage, and is determined after the completion of the test by the following:

[0239]

number

[0240] Method for processing a water suspension of solid particles The applicant has surprisingly discovered that using a water-soluble polymer obtained from the aforementioned crystalline form of ATBS.K improves the performance of suspension treatments including the following: - To increase the sludge concentration at the outlet of the concentration device, - When the suspension is discharged onto the ground, the steps include dewatering the suspension, drying it, solidifying it, and - Mechanical processing of the processed suspension.

[0241] Accordingly, the present invention relates to a method for processing an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer, the polymer being obtained from the crystalline form of ATBS.K. Therefore, the method comprises mixing the suspension with the water-soluble polymer.

[0242] Such processing may be carried out in a concentration device, which is generally a retention zone in the form of a section of tube several meters in diameter having a conical bottom into which particles can settle. In one specific embodiment, an aqueous suspension is transported to the concentration device by a pipe (pipeline), and the water-soluble polymer is added to the pipe.

[0243] In a particular embodiment, the water-soluble polymer is added to a concentrator that already contains a suspension to be processed. In one typical mineral processing operation, the suspension is often concentrated in a concentrator. This results in a higher concentration of sludge discharged from the bottom of the concentrator and an aqueous fluid (referred to as liquor) released from the processed suspension, which is discharged by overflow from the top of the concentrator. Adding the water-soluble polymer increases the concentration of the sludge and increases the clarity of the liquor.

[0244] In a particular embodiment, the water-soluble polymer is added to the particle suspension as the suspension is being transported through a pipe to a deposition zone. Preferably, the water-soluble polymer is added to the pipe transporting the suspension to the deposition zone. The treated suspension is spread over the deposition zone for dewatering and solidification. The deposition zone may be an open state, such as an undefined area of ​​the ground, or it may be a closed state, such as a basin or cell.

[0245] One example of these treatments while the suspension is being transported is to spread the suspension treated with the water-soluble polymer on the ground to dehydrate and solidify it, and then spread a second layer of the treated suspension on top of the first solidified layer.

[0246] Another example is to continuously spread the suspension treated with the water-soluble polymer so that the treated suspension falls continuously onto the suspension previously discharged into the deposition zone, thereby forming a mass of the treated material from which water is extracted.

[0247] In a particular embodiment, the water-soluble polymer is added to the suspension and then subjected to mechanical treatment such as centrifugation, pressing, or filtration.

[0248] The water-soluble polymer may be added simultaneously at different stages of the suspension processing process, namely, for example, in a pipe (pipeline) transporting the suspension to a concentrator and in the slurry exiting the concentrator, the slurry being transported to either a deposition zone or a mechanical processing device.

[0249] The water-soluble polymer may be added to the aqueous suspension to be treated in liquid or solid form. It may be added in the form of an emulsion (preferably a water-in-oil emulsion), an aqueous or oily multiphase particulate suspension, or a powder. Preferably, the water-soluble polymer is added in the form of an aqueous solution obtained from a concentrated form of the water-soluble polymer, such as a powder, a water-in-oil emulsion, or an aqueous or oily multiphase particulate suspension.

[0250] In a particular embodiment, the aqueous multiphase particulate suspension is preferably: - At least one water-soluble polymer in the form of solid particles with an average particle size of 5 to 500 μm, present in an amount of 15 to 60% by mass; - 15 to 45% by mass of at least one alkali metal salt and / or at least one alkaline earth metal salt; - At least one thickening agent other than the aforementioned water-soluble polymer; - At least 10% by mass of water, The suspension contains a Brookfield viscosity of 500 to 20,000 cps at a temperature of 20°C; and The suspension is 1.1-2 kg·L -1 It has a density of .

[0251] In a particular embodiment, the oily multiphase fine particle suspension is preferably: - At least one water-soluble polymer in the form of solid particles with an average particle size of 5 to 500 μm, present in an amount of 15 to 60% by mass; - At least one thickening agent other than the aforementioned water-soluble polymer; - At least 10% by mass of oil, The suspension contains a Brookfield viscosity of 500 to 20,000 cps at a temperature of 20°C; and The suspension is 0.6 to 1.4 kg·L -1 It has a density of .

[0252] Brookfield viscosity is measured using a Brookfield apparatus equipped with an LV module, which is rotatable at a speed of, for example, 30 rpm, and measurements are advantageously performed at 20°C. Density is measured at 20°C and a pressure of 1 atm, i.e., 101,325 Pa.

[0253] If the water-soluble polymer is a solid, it can be partially or completely dissolved in water using a polymer preparation unit such as a polymer slicing unit (PSU) disclosed in European Patent No. 2203245.

[0254] In certain embodiments, the water-soluble polymer is added to the suspension in combination with at least one other synthetic or natural polymer. These polymers may be added simultaneously or separately (before or after the addition of the water-soluble polymer). The other polymer may be water-soluble or water-swellable. It may be a dispersant, a coagulant, or a flocculant.

[0255] In certain embodiments, the water-soluble polymer is added to the suspension in combination with a salt, such as a calcium salt and / or a magnesium salt. The water-soluble polymer and the salt may be added simultaneously or separately. The salt may be inorganic or organic. Suitable salts include calcium chloride, calcium acetate, calcium sulfate, calcium nitrate, calcium hydroxide, calcium carbonate, magnesium chloride, magnesium acetate, magnesium sulfate, magnesium nitrate, magnesium hydroxide, magnesium carbonate, calcium formate, calcium gluconate, calcium propionate, tricalcium phosphate, and calcium succinate.

[0256] The amount of water-soluble polymer added to the aqueous suspension is advantageously 50 to 5000 g per ton of solid particles, preferably 250 to 2000 g / t, and more preferably 500 to 1500 g / t, based on the dry weight of the suspension. The amount varies depending on the properties and composition of the suspension being treated. Those skilled in the art will know how to adjust this amount, and such adjustments will be considered a matter of routine procedure.

[0257] According to the present invention, the method can be used to effectively process suspensions of solid particles, more specifically, mineral particles.

[0258] Aqueous suspensions of solid particles include all kinds of sludge, residue, or waste materials. More specifically, the suspensions arise from mineral extracts and are in the form of mineral particle suspensions. They may be industrial sludge or residues and all washing and waste products resulting from mining operations such as coal mines, diamond mines, phosphate mines, and metal mines (aluminum, platinum, iron, gold, copper, silver, etc.). The suspensions may also originate from oil sands extraction and may be sludge or extraction residues obtained from the processing of oil sands, for example. These suspensions generally include organic and / or inorganic particles such as clay, sediment, sand, metal oxides, and oil, for example, when mixed with water.

[0259] Generally, the suspension of solid particles is concentrated and contains 5% to 60% by weight of solid particles, preferably 20% to 50% by weight of solid particles, relative to the total weight of the suspension.

[0260] The method according to the present invention may also be useful for the treatment of residues from oil sands extraction that contain a large amount of clay, referred to as "fine powder" or "fine tailings," and for the treatment of fine tailings (MFTs), referred to as "mature fine tailings," which are the same fine residues that have accumulated for several years and contain an even larger amount of clay. The method according to the present invention may also be used for the treatment of so-called "new" residues, i.e., residues that arise directly from the process of separating bitumen from the soil from which it is extracted.

[0261] Method for agglomerating a suspension of solid particles in water The present invention also relates to a method for agglomerating an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer obtained from the crystalline form of ATBS.K having a powder X-ray diffraction pattern with peaks at 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7° (±0.1°).

[0262] All of the embodiments described above regarding methods for processing aqueous suspensions of solid particles are also applicable to methods for agglomerating aqueous suspensions of solid particles.

[0263] Methods for the Enhanced Recovery of Hydrocarbons (Petroleum and / or Gas) The present invention a) A step of preparing an injection fluid containing at least one water-soluble polymer of 2-acrylamido-2-methylpropanesulfonic acid using water or brine; 2-Acrylamide-2-methylpropanesulfonic acid is the crystalline form of ATBS.K having a powder X-ray diffraction pattern before polymerization that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°; step; b) The step of injecting the injection fluid into the underground geological formation; c) A step of sweeping the underground geological formation using the injection fluid; d) A step of recovering the aqueous hydrocarbon mixture, This relates to a method for the enhanced recovery of hydrocarbons (petroleum and / or gas) containing [unspecified substances].

[0264] If the water-soluble polymer used in the production of the injection fluid is in powder form, the average particle size of the water-soluble polymer is advantageously less than 1.5 millimeters, preferably less than 850 micrometers. The average particle size of the water-soluble polymer is advantageously greater than 5 μm.

[0265] The average particle size of the water-soluble polymer particles is the average particle size of the maximum dimensions, which is, for example, the diameter in the case of spherical particles. The average particle size is advantageously measured using a laser measuring device employing the prior art, which is part of the knowledge of those skilled in the art. For example, a Malvern Mastersizer, such as the MS2000, can be used for this purpose. Such devices can be used to measure the particle size distribution of particles in a liquid medium or in solid form by laser diffraction.

[0266] If the water-soluble polymer is in the form of particles, it can be dissolved in an aqueous medium in a dispersion device. A polymer slicing unit (PSU) described in U.S. Patent No. 8,186,871 is an example of a dispersion device that can be used to produce concentrated polymer aqueous solutions.

[0267] The water or brine used in the production of the injection fluid may be production water. “Production water” means all brine or non-brine, brine, seawater, or aquifer water from the hydrocarbon reservoir. This production water may be treated before the production of the injection fluid, as described in the International Publication No. 2018 / 020175 of the patent application.

[0268] The water-soluble polymer may be combined with a stabilizing compound. The stabilizing compound (stabilizer) may be a compound that adequately protects the polymer from, for example, thermal, chemical, and / or physical decomposition. Examples of suitable stabilizers are described in the international publication of the patent application 2010 / 133258.

[0269] Depending on the technology used, the injection fluid containing the water-soluble polymer may be injected alone or in combination with one or more chemical compounds that can be used for enhanced hydrocarbon (petroleum and / or gas) recovery. These chemical compounds may include the use of weak, strong, or very strong inorganic or organic bases that can saponify crude oil and generate surface-active species in situ that solubilize hydrocarbons, particularly petroleum. Examples include sodium carbonate or potassium carbonate, caustic soda, borate and metaborate compounds, amines, and basic polymer species. Another family of compounds often injected with polymers is the family of surface-active compounds, which are often anionic, zwitterionic, cationic, and sometimes nonionic. These compounds are rarely injected alone and are generally injected with co-surfactants and co-solvents to improve their compatibility and effectiveness in reservoirs (subterranean formations).

[0270] The injection fluid preferably contains 10 to 15,000 ppm by weight, preferably 50 to 10,000 ppm by weight, and more preferably 100 to 5,000 ppm by weight of a water-soluble polymer.

[0271] Surprisingly, the applicant has discovered that the water-soluble polymer obtained from the crystalline form of ATBS.K exhibits better filterability and better resistance to chemical and thermal decomposition than polymers of equivalent molecular weight obtained from 2-acrylamido-2-methylpropanesulfonic acid, which is not the crystalline form of ATBS.K. It is also known that filterability deteriorates with increasing molecular weight of the polymer. One advantage of the present invention is the possibility of obtaining water-soluble polymers with very high molecular weights that simultaneously exhibit good filterability. In addition, the concentration of water-soluble polymer required to bring the injection fluid to the target viscosity is reduced, which improves the economic conditions for recovering hydrocarbons (petroleum and / or gas) contained in subsurface formations.

[0272] The purpose of the water-soluble polymer according to the present invention is to thicken water injected into a reservoir (underground formation) containing hydrocarbons (petroleum and / or gas) in order to ensure mobility control without requiring crosslinking, i.e., chemical interchain crosslinking.

[0273] In a particular embodiment, a method for enhanced hydrocarbon (petroleum and / or gas) recovery includes the following steps: a) Step of preparing an injection fluid containing a water-soluble polymer with a molecular weight of more than 5 million g / mol: - The injectable fluid has a salt concentration of over 100 g / l, containing a maximum of 50 g / l of divalent salts; - The polymer comprises at least 80% mol of 2-acrylamido-2-methylpropanesulfonic acid, of which, advantageously, at least 50 mol%, preferably at least 70 mol%, and more preferably 100 mol%, of 2-acrylamido-2-methylpropanesulfonic acid is the crystalline form of ATBS.K before polymerization; - The concentration of the water-soluble polymer in the injection fluid is less than 3000 ppm by weight; - The pressurized fluid has viscosity V1 prior to shear step b); b) A step in which the pressurized fluid is sheared in order to obtain a viscosity reduction of more than 25% relative to V1, in this case:

[0274]

number

[0275] And in the formula, V1 is the viscosity of the injection fluid before the shear step at the temperature of the geological formation; V2 is the viscosity of the injection fluid after the shear step at the temperature of the geological formation; V water is the viscosity of the water used to produce the injection fluid at the temperature of the geological formation; c) The step of injecting the injection fluid into a subsurface formation, wherein the subsurface formation is a carbonate formation with a permeability of less than 300 millidarcy and a temperature of more than 100°C; c) A step of sweeping the underground geological formation using the injection fluid; d) A step of recovering the aqueous hydrocarbon (oil and / or gas) mixture.

[0276] The shearing step may be carried out using, for example, a valve, port, or pump.

[0277] Preferably, the concentration of the divalent salt in the injection fluid is 3 to 50 g / l.

[0278] A carbonate layer is a sedimentary rock layer in which the carbonate composition is at least 50%.

[0279] Fragmentation fluid The present invention relates to a fracturing fluid comprising an aqueous phase, at least one propping agent, and at least one water-soluble polymer obtained from 2-acrylamido-2-methylpropanesulfonic acid, which is the crystalline form of ATBS.K, having a powder X-ray diffraction pattern that includes peaks at positions where 2θ(±0.1°) is 13.1°;14.4°;16.3°;19.8°;23.5°;24.3°;26.9°;27.6°;29.3°;30.6°;31.6°;34.3°;36.1°;41.7°;44.6°;46.7°.

[0280] The aqueous phase is preferably selected from seawater, brine, and freshwater, with brine being preferable.

[0281] The brine is a solution containing water and an organic or inorganic salt. The salt may be a monovalent salt, a divalent salt, a trivalent salt, or a mixture thereof. Advantageously, the brine contains at least 1,000 mg / L of salt, preferably at least 5,000 mg / L, more preferably at least 10,000 mg / L, and even more preferably at least 50,000 mg / L of salt, and even more preferably the brine is saturated with salt.

[0282] The propping agent may be selected from an unspecified list of sand, ceramics, bauxite, glass beads, and resin-impregnated sand.

[0283] Advantageously, the amount of the propping agent in the crushing fluid is 0.5 to 40% by weight, preferably 1 to 25% by weight, and more preferably 1.5 to 20% by weight, relative to the total weight of the crushing fluid.

[0284] Advantageously, the crushing fluid contains a water-soluble polymer obtained from the crystalline form of ATBS.K in an amount of 0.001% to 1% by weight, preferably 0.002% to 0.2% by weight, relative to the total weight of the crushing fluid.

[0285] The aforementioned fracturing fluid is, for example, one described in document SPE 152596: - Clay swelling inhibitors such as potassium chloride or choline chloride, and / or - Biocides to prevent the growth of bacteria, especially sulfate-reducing bacteria. Sulfate-reducing bacteria can form viscous clumps that reduce pathway surfaces. Examples include glutaraldehyde, which is the most commonly used, or in practice formaldehyde, or isothiazolinone, and / or - Deoxidizing agents such as ammonium bisulfite to prevent the destruction of other components due to oxidation and corrosion of the press-fit pipe, and / or - N,N-dimethylformamide is preferred as a corrosion-preventive additive to protect the pipe from oxidation by residual oxygen, and / or - Lubricants such as petroleum distillates, and / or - Iron chelating agents such as citric acid, EDTA (ethylenediaminetetraacetic acid), phosphonates, and / or - Scale inhibitors such as phosphates, phosphonates, polyacrylates, or ethylene glycol. This may include other compounds known to those skilled in the art, such as the following.

[0286] Prior to being used in the crushing fluid, the water-soluble polymer according to the present invention may be in various solid or liquid forms. Preferably, it may be in the form of a powder, a water-in-oil reversed-phase emulsion, an aqueous multiphase fine particle suspension, or an oily multiphase fine particle suspension.

[0287] Method for manufacturing crushed fluid The present invention also relates to a method for producing a fracturing fluid by adding to water or brine at least one water-soluble polymer (as described above) obtained from 2-acrylamido-2-methylpropanesulfonic acid, which is the crystalline form of ATBS.K, wherein the water-soluble polymer is present before the formation of the fracturing fluid: - In powder form, - Or in the form of a water-in-oil reversed-phase emulsion, - Or in the form of an aqueous or oil-based multiphase fine particle suspension.

[0288] A method for producing a fracturing fluid according to the present invention preferably includes the step of adding at least one propping agent to the fluid, as previously described.

[0289] If the water-soluble polymer added to the crushing fluid is in powder form before the formation of the crushing fluid, the average particle size of the polymer particles is advantageously less than 1.5 millimeters, preferably less than 850 micrometers, and more preferably less than 200 micrometers. The average particle size of the water-soluble polymer particles is advantageously greater than 5 μm.

[0290] The average particle size of the water-soluble polymer particles is the average particle size of the maximum dimensions, which is, for example, the diameter in the case of spherical particles. The average particle size is advantageously measured using a laser measuring device employing the prior art, which is part of the knowledge of those skilled in the art. For example, a Malvern Mastersizer, such as the MS2000, can be used for this purpose. Such devices can be used to measure the particle size distribution of particles in a liquid medium or in solid form by laser diffraction.

[0291] If the water-soluble polymer according to the present invention is a solid, it can be partially or completely dissolved in water using a polymer preparation unit such as a polymer slicing unit (PSU) disclosed in European Patent No. 2203245.

[0292] If the water-soluble polymer added to the crushing fluid is in the form of a water-in-oil reversed-phase emulsion before the formation of the crushing fluid, the concentration of the water-soluble polymer in the emulsion is preferably 5 to 60% by weight, more preferably 15 to 40% by weight, relative to the weight of the emulsion.

[0293] In preferred embodiments of the present invention, the water-in-oil reverse-phase emulsion may contain 0.01% to 70% by weight, preferably 5% to 20% by weight, of organic and / or inorganic salts relative to the weight of the emulsion. The salts may be selected from an unlimited list of sodium chloride, sodium sulfate, sodium bromide, ammonium sulfate, ammonium chloride, lithium chloride, lithium bromide, potassium chloride, potassium bromide, magnesium sulfate, aluminum sulfate, and mixtures thereof. Preferred salts are ammonium chloride and ammonium sulfate.

[0294] If the water-soluble polymer added to the crushing fluid is in the form of an aqueous multiphase fine particle suspension before the formation of the crushing fluid, the suspension is preferably: - At least one water-soluble polymer in the form of solid particles with an average particle size of 5 to 500 μm, in an amount of 15 to 60% by weight; - 15-45% by weight of at least one alkali metal salt and / or at least one alkaline earth metal salt; - At least one thickening agent other than the aforementioned water-soluble polymer; - At least 10% by weight of water, The suspension contains a Brookfield viscosity of 500 to 20,000 cps at a temperature of 20°C; and The suspension is 1.1-2 kg·L -1 It has a density of .

[0295] If the water-soluble polymer added to the crushing fluid is in the form of an oily multiphase fine particle suspension before the formation of the crushing fluid, the suspension is preferably: - At least one water-soluble polymer in the form of solid particles with an average particle size of 5 to 500 μm, in an amount of 15 to 60% by weight; - At least one thickening agent other than the aforementioned water-soluble polymer; - At least 10% by weight of oil, The suspension contains a Brookfield viscosity of 500 to 20,000 cps at a temperature of 20°C; and The suspension is 0.6 to 1.4 kg·L -1 It has a density of .

[0296] Brookfield viscosity is measured using a Brookfield apparatus equipped with an LV module, which is rotatable at a speed of, for example, 30 rpm, and measurements are advantageously performed at 20°C. Density is measured at 20°C and a pressure of 1 atm, i.e., 101,325 Pa.

[0297] Hydraulic fracturing method for unconventional underground oil or gas reservoirs The present invention also relates to a method for hydraulic fracturing of an unconventional underground oil or gas reservoir, comprising, as previously described, producing a fracturing fluid and injecting the fracturing fluid into the underground reservoir.

[0298] The injection is carried out under pressure to form a fractured section that is distributed throughout the entire length of the production well.

[0299] If desired, at least one oxidizing compound and / or at least one surfactant compound are injected into the reservoir before, during, or after the formation of the crushed section.

[0300] Injecting surfactant compounds helps eliminate the viscosity produced by the polymer by inhibiting hydrophobic interchain interactions, while injecting oxidizing compounds destroys the polymer. In either case, injection can re-establish a fluid viscosity close to that of water.

[0301] Oxidizing compounds include bleach (aqueous solutions of hypochlorite), hydrogen peroxide, ozone, chloramine, persulfates, permanganates, and perchlorates.

[0302] The chemical properties of the surfactant compound are not important. It may be anionic, nonionic, amphoteric, zwitterionic, and / or cationic. The surfactant compound of the present invention preferably has an anionic charge.

[0303] Preferably, the surfactant compound used is selected from anionic surfactants and their zwitterions, selected from the group including derivatives such as alkyl sulfate, alkyl ether sulfate, aryl alkyl sulfate, aryl alkyl ether sulfate, alkyl sulfonate, alkyl ether sulfonate, aryl alkyl sulfonate, aryl alkyl ether sulfonate, alkyl phosphate, alkyl ether phosphate, aryl alkyl phosphate, aryl alkyl ether phosphate, alkyl phosphonate, alkyl ether phosphonate, aryl alkyl phosphonate, aryl alkyl ether phosphonate, alkyl carboxylate, alkyl ether carboxylate, aryl alkyl carboxylate, aryl alkyl ether carboxylate, polyalkyl ether, and aryl alkyl polyether.

[0304] An alkyl chain is defined as a branched or unbranched chain having 6 to 24 carbon atoms, which may or may not have multiple units and may optionally contain one or more heteroatoms (O, N, S). An arylalkyl chain is defined as a branched or unbranched chain having 6 to 24 carbon atoms, which contains one or more aromatic rings and optionally contains one or more heteroatoms (O, N, S).

[0305] For reasons of cost, stability, and availability, the most commonly used surfactant compounds are sulfonate or sulfate types in the form of alkali metal salts or ammonium salts.

[0306] A method for reducing friction of the fracturing fluid during hydraulic fracturing of unconventional underground oil or gas reservoirs. The present invention also relates to a method for reducing friction of a fracturing fluid in hydraulic fracturing operations of an unconventional underground oil or gas reservoir, comprising, as previously described, manufacturing the fracturing fluid and injecting the fracturing fluid into the underground reservoir.

[0307] Friction reduction reduces or eliminates losses (pressure) caused by friction during the injection of the crushing fluid.

[0308] Other uses of polymers Another aspect of the present invention relates to the use of a polymer obtained from the crystalline form of ATBS.K.

[0309] The present invention also relates to the use of this polymer in well drilling or cementing; conformance, diversion; open, closed, or semi-closed circuit water treatment; fermentation broth treatment; sludge treatment; construction; paper or cardboard manufacturing; batteries; wood processing; hydraulic composition (concrete, cement, mortar, and aggregates); cosmetic preparation; detergent preparation; textile manufacturing; geothermal energy; diaper manufacturing; or agriculture.

[0310] The present invention also relates to the use of this polymer as a coagulant, binder, absorbent, water remover, filler retainer, dehydrating agent, conditioning agent, stabilizer, fixative, film-forming agent, sizing agent, superplasticizer, clay inhibitor, or clay dispersant.

[0311] The present invention and its advantages will be better understood by referring to the following figures and examples provided to illustrate the invention in a non-limiting manner. [Brief explanation of the drawing]

[0312] [Figure 1] Figure 1 shows the proton NMR spectrum of the ATBS needle crystal obtained according to Example 1. [Figure 2] Figure 2 shows the proton NMR spectrum of the ATBS.K crystal obtained according to Example 2a. [Figure 3] Figure 3 shows the X-ray diffraction pattern of the ATBS crystal obtained according to Example 1. [Figure 4] Figure 4 shows the X-ray diffraction pattern of the ATBS.K crystal obtained according to Example 2a. [Figure 5] Figure 5 shows the Fourier transform infrared spectrum of the ATBS crystal obtained according to Example 1. [Figure 6] Figure 6 shows the Fourier transform infrared spectrum of the ATBS.K crystal obtained according to Example 2a. [Figure 7] Figure 7 shows the thermogram of the ATBS crystal obtained according to Example 1. [Figure 8] Figure 8 shows the thermogram of the ATBS.K crystal obtained according to Example 2a. [Figure 9] Figure 9 shows the particle size distribution of the ATBS crystals obtained according to Example 1. [Figure 10] Figure 10 shows the grain size distribution of the ATBS.K crystals obtained according to Example 2a. [Figure 11]Figure 11 shows an optical microscope image of the ATBS crystal obtained according to Example 1. [Figure 12a] Figure 12a shows an optical microscope image of the ATBS.K crystal obtained according to Example 2a. [Figure 12b] Figure 12b shows the thermogram of the ATBS.K crystal obtained according to Example 2b. [Figure 12c] Figure 12c shows the thermogram of the ATBS.K crystal obtained according to Example 2c. [Figure 12d] Figure 12d shows a photograph of the ATBS.K product obtained in solution according to Comparative Example 2b (according to U.S. Patent No. 6,331,647 (Example 27)). [Figure 12e] Figure 12e shows an optical microscope image of the ATBS.K crystal obtained according to Comparative Example 2c (according to International Publication No. 2013079507 (Example 3)). [Figure 12f] Figure 12f shows an optical microscope image of the ATBS.K crystal obtained according to Comparative Example 2d. [Figure 12g] Figure 12g shows an optical microscope image of the ATBS.K crystal obtained according to Comparative Example 2e. [Figure 13] Figure 13 shows the corrosion effect of ATBS, used in the form of an acid (Example 1) or as potassium salt crystals (Example 2a), on carbon steel sheets at 50°C after 15 days. [Figure 14] Figure 14 shows the friction reduction rate of the polymer as a function of time. [Figure 15] Figure 15 shows the friction reduction rate of homopolymers as a function of time. [Figure 16] Figure 16 shows the friction reduction rate of the terpolymer as a function of time. [Figure 17] Figure 17 shows the friction reduction rate of the post-hydrolyzed polymer as a function of time. [Figure 18] Figure 18 shows the effect of the ATBS form on the viscosity reduction of solutions of homopolymers P3 (the present invention) and P'3 (the acidic form of ATBS) in contact with different amounts of iron(II) contaminants. [Figure 19]Figure 19 shows the effect of the ATBS form on viscosity reduction when polymers P3 (the present invention) and P'3 (the acidic form of ATBS) are aged at 90°C. [Figure 20] Figure 20 shows the effect of the ATBS form on the viscosity reduction of solutions of homopolymers P5 (the present invention) and P'5 (the acidic form of ATBS) in contact with different amounts of iron(II) contaminants. [Examples]

[0313] Example 1: 2-acrylamido-2-methylpropanesulfonic acid (ATBS) (A H ) synthesis 1522 g of acrylonitrile containing 0.4% by weight of water and 180 g of fuming sulfuric acid (18% oleum) with a H2SO4 titer of 104% are added to a 2000 ml reactor equipped with a stirrer and a double jacket. The mixture is stirred for 1 hour, and the temperature of the sulfonated mixture is maintained at -20°C by cooling with the double jacket of the reactor.

[0314] 97 g of isobutylene is added to the sulfonated mixture at a rate of 1.6 g / min.

[0315] When adding isobutylene, the temperature of the mixture is controlled to 45°C. ATBS particles precipitate from the mixture, and the solid content is approximately 20% by weight. The reaction mixture is filtered through a Buchner funnel and dried under reduced pressure at 50°C. The resulting solid is 2-acrylamido-2-methylpropanesulfonic acid (ATBS A H It is in the form of a very fine white powder.

[0316] Observation with an optical microscope (Figure 11) was performed using ATBS A H This indicates that the aforementioned crystals have a needle-like shape.

[0317] Example 2a: Potassium 2-acrylamido-2-methylpropanesulfonate (ATBS.KA) K 2a) Formation of the aforementioned crystal form (the present invention) Add 477g of 28% (by weight in water) potassium hydroxide aqueous solution to a 1000ml reactor with a stirrer and double jacket. Add 452g of ATBS A H Add this to the mixture mentioned earlier.

[0318] The mixture is stirred at 10°C for 30 minutes to form an aqueous solution SA2.

[0319] The aqueous solution SA2 is heated to a temperature of 40°C under reduced pressure of 50 mbar for 20 minutes, then maintained at the same temperature under reduced pressure of 50 mbar for 30 minutes, and cooled to a temperature of 10°C. The cooling time from 40°C to 10°C is 6 hours. A suspension S1 of the ATBS.K crystals is obtained. The suspension S1 is filtered using a Robatel vertical centrifuge. ATBS.K K A solid of composition C1 containing 80% by weight of the aforementioned crystals of 2a is obtained.

[0320] Observation with an optical microscope (Figure 12a) shows that crystal A K This indicates that 2a has both cylindrical and plate-like forms.

[0321] Example 2b: ATBS potassium salt (ATBS.KA K 2b) Formation of the crystal form Except for distilling SA2 under 700 mbar, follow the procedure described in Example 2a to obtain ATBS.KA. K Prepare the aforementioned crystal 2b.

[0322] Optical microscope observation (Figure 12b) shows the crystal A obtained under these conditions. K 2b is ATBS.KA prepared in Example 2a. K This indicates that it is identical to the aforementioned crystal of 2a.

[0323] Example 2c: ATBS potassium salt (ATBS.KA K Formation of the crystal form in 2c) Except for shortening the cooling time to 3 hours and 45 minutes, the procedure for ATBS.KA was carried out according to the method described in Example 2a. K Prepare the aforementioned crystal of 2c.

[0324] Optical microscopy observation (Figure 12c) shows that the crystals obtained under these conditions are ATBS.KA K This indicates that it is identical to the aforementioned crystal of 2a.

[0325] Comparative Example 2a: Preparation of ATBS.K crystals under atmospheric pressure (1 bar) (CE-A K 2a) (Not obtained) The reaction is carried out according to the procedure described in Example 2a, except that SA2 is distilled under atmospheric pressure.

[0326] After the cooling step is complete, the aqueous solution SA2 does not form a suspension S1, and therefore cannot be filtered or centrifuged to isolate the ATBS potassium salt crystals.

[0327] Comparative Example 2b: Preparation of ATBS potassium salt crystals (CE-A K 2b) (Not obtained) The reaction was carried out according to the conditions described in Example 27 of U.S. Patent No. 6,331,647. Add 124 g of potassium hydroxide and 0.13 g of hydroquinone monomethyl ether to a 5000 ml reactor with a double jacket and a stirrer containing 400 g of water. Stir the medium until all of the potassium hydroxide is dissolved.

[0328] 632g ATBS A H Add the above mixture. Stir the mixture at 10°C for 30 minutes to form an aqueous solution of ATBS.K.

[0329] The resulting aqueous solution is filtered into a 3000 ml reactor equipped with an air purge tube and fitted with a distillation apparatus. The contents are heated and stirred while air is blown in below the water surface at 0.5 cubic feet per hour. The contents are heated to 50°C under reduced pressure of 933 mbar (approximately 700 milliliters of mercury). Once the water is removed, a yellowish, honey-like product is obtained. The product is then transferred to a Robatel vertical centrifuge, but no solid is recovered.

[0330] Since a solid sample could not be obtained, observation using an optical microscope was not possible (Figure 12d).

[0331] Comparative Example 2c: Preparation of ATBS potassium salt crystals (CE-A K 2c) (Not obtained) The reaction was carried out according to the conditions described in Example 3 of the International Patent Application Publication No. 2013079507.

[0332] 100 g of ATBS.K solution (16.77 wt%) is obtained according to Example 1 of International Publication No. 2013079507.

[0333] From the ATBS.K solution, 50 g of solvent is removed at room temperature under reduced pressure and while introducing air into the ATBS.K solution. Next, the formed solid is filtered, washed with acrylonitrile / methanol, and then dried overnight at 50°C.

[0334] Optical microscope observation (Figure 12e) was performed using ATBS.K CE-A. K This indicates that the dried solid of 2c does not correspond to the aforementioned crystal of ATBS.K according to the present invention.

[0335] Comparative example 2d: ATBS.K CE-A K Preparation of 2d (not according to the present invention) The reaction is carried out according to the procedure described in Example 2a, except that SA2 is distilled under 720 mbar.

[0336] ATBS.K CE-A K A solid of composition C1 containing 80% by weight of 2d crystals is obtained.

[0337] Optical microscope observation (Figure 12f) was performed using ATBS.K CE-A K This indicates that the 2d crystal does not correspond to the aforementioned crystal of ATBS.K according to the present invention.

[0338] Comparative example 2e: ATBS.K CE-A K Preparation of 2e (not according to the present invention) The reaction is carried out according to the procedure described in Example 2a, except that the cooling time is 3 hours and 20 minutes.

[0339] ATBS.K CE-A K A solid of Composition C1 containing 80% by weight of the crystals of 2e is obtained.

[0340] Optical microscopy observation (Figure 12g) shows that the crystals of ATBS.K CE-A K are not equivalent to the crystals of ATBS.K according to the present invention.

[0341] Example 3: ATBS A from Examples 1 and 2a H and ATBS.K A K NMR analysis of the 2a product ATBS A H and ATBS.K A K 2a is analyzed by proton nuclear magnetic resonance (NMR).

[0342] The sample is dissolved in D2O. The NMR apparatus is a Bruker model with a frequency of 400 MHz and a 5 mm BBO BB- 1 to which H is attached.

[0343] The two proton spectra (Figures 1 and 2) are similar, and the peak assignments are consistent with the molecular structure of ATBS or its potassium salt.

[0344] Example 4: ATBS A from Examples 1 and 2a H and ATBS.K A K Analysis of the 2a product by X-ray diffraction ATBS A H and ATBS.K A [[ID=*]] K The crystals of 2a are pre-ground to form a powder and analyzed by X-ray diffraction over an angular range of 10° to 90°. The apparatus used is a Rigaku MiniFlex II diffractometer equipped with a copper X-ray source.

[0345] ATBS.K A KThe crystal of 2a (Figure 4) shows an X-ray diffraction pattern with characteristic peaks at the positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

[0346] ATBS A H The same peak is not observed in the X-ray diffraction pattern (Figure 3).

[0347] Example 5: ATBS A H and ATBS.KA K Fourier transform infrared measurement of 2a The instrument used for Fourier transform infrared measurements is an 8cm² instrument equipped with a single-reflection ATR polarization accessory. -1 This is the Perkin Elmer Spectrum 100 with that level of precision.

[0348] ATBS A H and ATBS.KA K Sift 2a through to 100 μm. Dry the particles remaining on the sieve and place in a 60°C oven for at least 4 hours.

[0349] A few hundred milligrams of solid material are placed on the diamond of the ATR accessory, and pressure is applied manually using the accessory.

[0350] The following band (Figure 6) represents ATBS potassium salt A K The aforementioned crystal form of 2a is characteristic: 3293cm -1 , 3075cm -1 , 3000cm -1 , 2979cm -1 , 1655cm -1 , 1625cm -1 , 1550cm -1 , 1405cm -1 , 1209cm -1 , 1190cm -1 , 1162cm -1 , 1048cm -1, 979cm -1 , 824cm -1 , 803cm -1 , 756cm -1 , 633cm -1 , 523cm -1 .

[0351] ATBS A H The infrared spectrum (Figure 5) does not show the same peak.

[0352] Example 6: ATBS A from Examples 1 and 2a H and ATBS.KA K 2a Differential scanning calorimetry (DSC) of the product The device used is the Mettler DSC3.

[0353] ATBS A H and ATBS.KA K The crystals of 2a are analyzed under a nitrogen atmosphere with a heating gradient of 10°C / min. The initial temperature is 30°C, and the product is heated to 350°C.

[0354] ATBS A H The thermogram of the crystal (Figure 7) shows a thermal effect at a temperature of 195.15°C, which is generally considered to be the melting / decomposition point of 2-acrylamido-2-methylpropanesulfonic acid.

[0355] ATBS.KA K The thermogram of crystal 2a (Figure 8) shows two thermal phenomena at 79.4°C and 207°C.

[0356] In comparison, the thermogram of the crystal in Example 1 shows only one decomposition peak at 195.15°C, followed by two exothermic decomposition phenomena at 212.8°C and 288.4°C (Figure 7).

[0357] Example 7: ATBS A from Examples 1 and 2a H and ATBS.KA K Measurement of the minimum ignition energy (MIE) of the 2a product The minimum ignition energy is measured according to the NF EN 13821 standard.

[0358] The explosion force meter is a vertical Hartmann tube. The dust dispersion system is mushroom-shaped.

[0359] The total induction is less than 25 microhenries. The discharge voltage is 5kV to 15kV. The electrodes are made of brass and spaced at a minimum distance of 6mm.

[0360] Tests were conducted with different energies and dispersion masses, and the results are summarized in Tables 1 and 2.

[0361] ATBS.KA K In the aforementioned crystalline form of 2a, the needle-shaped ATBS A obtained in Example 1 is H It is clear that the risk of explosion is significantly lower than that.

[0362] [Table 1]

[0363] [Table 2]

[0364] Example 8: ATBS A from Examples 1 and 2a H and ATBS.KA K Particle size measurement of product 2a ATBS A H and ATBS.KA K The crystals of 2a are analyzed using laser diffraction to determine their particle size distribution.

[0365] The laser diffraction apparatus used is the Cilas 1190.

[0366] ATBS A H d of the crystal 50 The value is approximately 40 μm, and 90% of the particles are smaller than 100 μm (Figure 9).

[0367] ATBS.KA K d of crystal 2a 50 The value is approximately 600 μm, and 90% of the particles are smaller than approximately 1500 μm (Figure 10). ATBS.KA K The amount of particles smaller than 325 μm in the crystal of 2a is less than 10%.

[0368] Example 9: Evaluation of the corrosiveness of different forms of ATBS against carbon steel ATBS A H ,ATBS.KA K 2a, and ATBS.K CE-A K 20g each of 2c to 2e, 20 x 50mm 2 The material is deposited onto two carbon steel plates of the specified dimensions. The coated plates are placed in a 50°C oven for two weeks. At the same time, an uncoated control plate is placed under the same temperature conditions.

[0369] A photograph of the plate in this situation (Figure 13) is available at ATBS.KA. K Compared to crystal 2a, ATBS A H The plate that was in contact with the material shows visually more pronounced corrosion. These observations are confirmed by weighing the plate before and after the contact period.

[0370] Crystalline ATBS potassium salt CE-A K Tests 2c to 2e were also conducted. The results are shown in Table 3.

[0371] [Table 3]

[0372] Example 10a: ATBS.KA K Preparation of solution 2a 1000g ATBS.KA K The crystalline form of 2a and 1000 g of water are introduced into a 2000 ml double-jacketed reactor equipped with a condenser, pH meter, and stirrer. The pH of the mixture is greater than 12.

[0373] The resulting mixture is an aqueous solution of ATBS.K at a concentration of 50% by weight.

[0374] Example 10b: ATBS.K CE-A K Preparation of solution 2c ATBS.K CE-A K Using 2c crystals, the same protocol as in Example 10a is reproduced.

[0375] Example 10c: ATBS.K CE-A K Preparation of 2d solution ATBS.K CE-A K Using 2D crystals, the same protocol as in Example 10a is reproduced.

[0376] Example 10d: ATBS.K CE-A K Preparation of solution 2e ATBS.K CE-A K Using 2e crystals, the same protocol as in Example 10a is reproduced.

[0377] Example 11: Acid form of A H Preparation of ATBS.K solution 800g ATBS A H The mixture and 650g of water are introduced into a 2000ml double-jacketed reactor equipped with a condenser, pH meter, and stirrer. The pH of the mixture is less than 1.

[0378] Prepare a 50% by weight potassium hydroxide aqueous solution using a dropping funnel. Add this caustic solution to the reaction mixture over a period of 120 minutes. Maintain a temperature below 30°C.

[0379] The final pH of the aforementioned solution is 8-10.

[0380] Add 451 g of 50 wt% potassium hydroxide aqueous solution.

[0381] The resulting mixture is an aqueous solution of ATBS potassium salt at a concentration of 50% by weight.

[0382] Example 12: Effect of ATBS morphology and structure on preservation 500 g of 50% (by weight in water) aqueous solutions of ATBS.K prepared according to Examples 10a-10d and 11 were stored for 12 months to compare their stability over time by measuring and monitoring the appearance of ATBS.K homopolymers.

[0383] In parallel, ATBS (Acid A) in different solid forms H or potassium salt A K The stability of 2a) was also evaluated over the same period.

[0384] In this case, every three months, A H , A K 2a, and CE-A K Using the stored ATBS products from 2c to 2e, a fresh 500 g ATBS.K solution was prepared according to the preparation process described in Example 10a or 11.

[0385] The stability of the solid product was also evaluated by monitoring the amount of ATBS.K homopolymer present after that time.

[0386] The aforementioned solution was analyzed by liquid-phase steric exclusion chromatography using an Agilent 1260 chromatograph equipped with Aquagel-OH 20, 30, 40, and 50 columns capable of analyzing anionic polymers up to 600,000 g / mol of PEG equivalent.

[0387] The ATBS.K solution was diluted to 2000 ppm (by weight in water) before injection. The UV signal at 250 nm at the column outlet was integrated with respect to the polymer peak, and the results are detailed in Tables 4 and 5 below. A larger signal area indicates a higher polymer abundance and, therefore, lower product stability over time.

[0388] [Table 4]

[0389] [Table 5]

[0390] These results demonstrate that the crystalline form of ATBS.K of the present invention exhibits improved stability during storage, whether stored as a solid or in solution.

[0391] Example 13: Preparation of acrylamide (AM) / ATBS (75 / 25 mol%) polymer Example 13a: Polymer P1-A according to the present invention K 2a~P3-A K Preparation of 2a 628.3g of deionized water, 500g of 50% (by weight in water) acrylamide solution, 16.2g of urea, and 288.7g of ATBS.KA K Add the crystals from 2a to a 2000 ml beaker.

[0392] The resulting solution is cooled to 0-5°C, transferred to an adiabatic polymerization reactor, and bubbled with nitrogen for 30 minutes to remove all trace amounts of dissolved oxygen.

[0393] Next, the following are added to the reactor: - 0.75 g of 2,2'-azobisisobutyronitrile, - 1.5 ml of 5 g / L solution (in water) of 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, - 1.5 ml of 3 g / L solution of sodium hypophosphate (in water), - 2.25 ml of 1 g / L solution of tert-butyl hydroperoxide (in water), - 2.25 ml of a 1 g / L solution of ammonium iron(II) sulfate (Mohr's salt) in water.

[0394] After a few minutes, the nitrogen inlet is shut off and the reactor is closed. The polymerization reaction is carried out for 1 to 5 hours until the temperature reaches its peak. The resulting rubbery gel is cut into particles with a particle size of 1 to 6 mm.

[0395] Next, the gel is dried and pulverized to obtain polymer P1-A in powder form. K We obtain 2a.

[0396] Polymer P2-A K 2a and polymer P3-A K 2a is polymer P1-A K It is obtained by using the method for obtaining 2a and changing the amount of sodium hypophosphite. P2-A K 2a: 1.2 ml of a 3 g / l solution of sodium hypophosphite. P3-A K 2a: 1.5 ml of a 1 g / l solution of sodium hypophosphite.

[0397] Example 13b: Preparation of comparative polymer of ATBS / AM(75 / 25) Polymer P'1-A H P'2-A H , and P'3-A H 243g of ATBS A H And using 131.7 g of 50 wt% potassium hydroxide aqueous solution, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0398] Polymer P'1-CEA K 2c, P'2-CEA K 2c, P'3-CEA K 2c, ATBS CE-A K Using 2c, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0399] Polymer P'1-CEA K 2d, P'2-CEA K2d, P'3-CEA K 2d, ATBS CE-A K Using 2d, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0400] Polymer P'1-CEA K 2e, P'2-CEA K 2e, P'3-CEA K 2e, ATBS CE-A K Using 2e, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0401] Example 14: Preparation of ATBS homopolymer Polymer P4-A K 2a and P5-A K Adjust 2a so that the amount of monomer and excipients reaches the desired molar composition of ATBS 100 mol% (P4-A K 2a: 20 ml of 1 g / l sodium hypophosphite solution; P5-A K 2a: 3 ml of 1 g / l solution of sodium hypophosphite, polymer P1-A K Preparation of 2a is carried out according to the protocol described in Example 13a.

[0402] Polymer P'4-A H and P'5-A H These were 352.1g and 243g of ATBS A, respectively. H Furthermore, using 190.8 g of 50 wt% potassium hydroxide aqueous solution, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0403] Polymer P'4-CEA K 2c and P'5-CEA K 2c, ATBS CE-A K Using 2c, polymer P1-AK 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0404] Polymer P'4-CEA K 2d and P'5-CEA K 2d, ATBS CE-A K Using 2d, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0405] Polymer P'4-CEA K 2e and P'5-CEA K 2e, ATBS CE-A K Using 2e, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0406] Example 15: Preparation of a polymer of AM / ATBS / acrylic acid (AA) (71 / 9 / 20 mol%) Polymer P6-A K 2a is prepared by adjusting the amounts of monomer and excipient to reach the desired molar composition AM / ATBS / AA(71 / 9 / 20), and then preparing polymer P1 according to the protocol described in Example 13a.

[0407] Polymer P'6-A H Each contains 105.2g of ATBS A H And using 181.4 g of 50 wt% potassium hydroxide aqueous solution, polymer P1-A K The synthesis of 2a is obtained according to the protocol described.

[0408] Polymer P'6-CEA K 2c, ATBS CE-A K Using 2c, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0409] Polymer P'6-CEA K 2d, ATBS CE-A K Using 2d, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0410] Polymer P'6-CEA K 2e, ATBS CE-A K Using 2e, polymer P1-A K 2a~P3-A K The synthesis of 2a is obtained according to the protocol described.

[0411] Example 16: Preparation of a hydrolyzed polymer after AM / ATBS (90 / 10 mol%) Polymer P7-A K 2a is prepared by adjusting the amounts of monomer and excipient to reach the desired molar composition AM / ATBS(90 / 10) and following the protocol described in Example 13a for the preparation of polymer P1.

[0412] Next, 500.0 g of pre-cut gel is mixed with 22.5 g of 50% sodium hydroxide solution, and the mixture is heated and held at 90°C for 90 minutes.

[0413] Next, the gel is dried and pulverized to obtain polymer P7-A in powder form. K We obtain 2a.

[0414] Polymer P'7-A H 93.1g of ATBS A H And using 50.1 g of 50 wt% potassium hydroxide aqueous solution, polymer P7-A K The synthesis of 2a is obtained according to the protocol described.

[0415] Polymer P'7-CEA K 2c, ATBS CE-A K Using 2c, polymer P7-A K The synthesis of 2a is obtained according to the protocol described.

[0416] Polymer P'7-CEA K 2d, ATBS CE-A K Using 2d, polymer P7-A K The synthesis of 2a is obtained according to the protocol described.

[0417] Polymer P'7-CEA K 2e, ATBS CE-A K Using 2e, polymer P7-A K The synthesis of 2a is obtained according to the protocol described.

[0418] Example 17: Viscosity measurement of AM / ATBS (75 / 25 mol%) polymer solution The viscosity of the polymer prepared in Example 13 was measured at 25°C in a 0.5 M sodium chloride aqueous solution using a Brookfield LVT viscometer fitted with a UL adapter at 60 rpm.

[0419] Preparation of polymer solutions: Dissolve 500 mg of dry polymer in a beaker containing 290 ml of deionized water at a stirring speed of 500 rpm. Add 29.25 g of sodium chloride to the prepared solution. The solution is stirred at 700 rpm for 10 minutes to completely dissolve the salt. The prepared solution is filtered through a 200 μm mesh.

[0420] 16 ml of the prepared solution was transferred to a cylindrical tube, and viscosity measurements were performed using it. The viscosity results of the polymer solution are shown in Table 6.

[0421] [Table 6]

[0422] Polymers prepared using the novel crystalline form of ATBS.K have a higher viscosity than polymers prepared from conventional forms of ATBS.K or potassium salts of other crystalline forms.

[0423] Example 18: Preparation of a fracturing fluid for ATBS polymers The polymers of Examples 13-16 were dissolved in brine consisting of water, 85 g of sodium chloride (NaCl), and 33.1 g of calcium chloride (CaCl2·2H2O) per liter of brine, at a concentration of 10,000 ppm by weight, while stirring.

[0424] The resulting polymer saline solution is then injected at a concentration of 0.05 pptg (parts per 1000 gallons; 1 gallon = 3.78541 liters) into the brine that will be recycled for the subsequent flow-loop test.

[0425] Example 19: Flow loop friction reduction test of ATBS polymer To evaluate the friction reduction of each polymer, a flow loop tank is filled with 20 L of brine (the brine described in Example 18).

[0426] Next, the brine is recirculated through a flow loop at a rate of 24 gallons per minute. The polymer is added to the recirculating brine at a concentration of 0.5 pptg.

[0427] Thus, the friction reduction rate is determined by measuring the pressure fluctuations within the flow loop.

[0428] Figures 14-17 show polymers P1, P4, P6, and P7-A according to the present invention. K 2a, as well as comparative polymers P'1, P'4, P'6, and P'7-A H This graph shows the friction reduction rate as a function of time.

[0429] These figures show that the injection fluid according to the present invention improves friction reduction. In fact, friction reduction is improved when the polymer contains ATBS, which is the crystalline form of ATBS.K.

[0430] Example 20: Measurement of the filter ratio (FR) of an AM / ATBS (75 / 25 mol) polymer solution The filtration test was performed using the polymer described in Example 13.

[0431] Polymer solutions were prepared in brine containing water, 30,000 ppm NaCl, and 3,000 ppm CaCl2·2H2O (ppm by weight), at an active ingredient concentration of 1,000 ppm. The filter ratio (FR) was measured using a filter with a pore size of 1.2 μm, representing low-permeability sediments. The results are shown in Table 7.

[0432] [Table 7]

[0433] Table 7 shows that at equivalent molecular weights, polymers obtained from the aforementioned crystalline form of ATBS.K according to the present invention (P1-A K 2a, P2-A K 2a, and P3-A K It can be seen that 2a) always has a lower FR than polymers obtained from the amorphous form of ATBS.K or different crystalline forms of ATBS.K. This difference becomes increasingly pronounced as the molecular weight of the polymer increases.

[0434] Example 21: Measurement of resistance to chemical degradation of AM / ATBS(75 / 25) polymer solutions of equivalent molecular weight. Polymer P3-A of Example 13 K The resistance of comparative polymers of types 2a and P'3 to chemical degradation was tested in brine consisting of water, 37,000 ppm NaCl, 5,000 ppm Na2SO4, and 200 ppm NaHCO3 (ppm by weight), under aerobic conditions, in the presence of different concentrations of iron(II) (2, 5, 10, and 20 ppm). Polymer P3-A K 2a and P'3-A H Figure 18 shows the results obtained after contacting the solution with iron contaminants for 24 hours.

[0435] The results of the chemical degradation of all polymers P3 are detailed in Table 8.

[0436] [Table 8]

[0437] The results shown in Figure 18 and Table 8 are that at each iron(II) concentration, polymer P3-A K 2a is an equivalent comparative polymer P'3-A H and P'3-CEA K This demonstrates that the viscosity reduction is less than that of 2c~2e.

[0438] Example 22: Measurement of the thermal decomposition resistance of AM / ATBS(75 / 25) polymer solutions of equivalent molecular weight. Polymer P3-A of Example 13 K The thermal decomposition resistance of comparative polymers of types 2a and P'3 was tested in brine consisting of 30,000 ppm NaCl and 3,000 ppm CaCl2·2H2O (ppm by weight) under anaerobic conditions at an active ingredient concentration of 2,000 ppm. The polymer solution was aged at 90°C for 6 months.

[0439] Polymer P3-A K 2a and P'3-A H The results of the viscosity reduction of the solution are shown in Figure 19, and the results for all P3 polymers are detailed in Table 9 below.

[0440] [Table 9]

[0441] The results in Figure 19 and Table 9 are for polymer P3-A K 2a is an equivalent comparative polymer P'3-A H and P'3-CEA K This indicates less viscosity reduction compared to 2c~2e.

[0442] Example 23: Measurement of the filter ratio of a homopolymer solution of ATBS A filtration test was performed on polymers P4 to P5 prepared in Example 14 according to the procedure described in Example 20. The results are shown in Table 10.

[0443] [Table 10]

[0444] Table 10 shows that at equivalent molecular weights, polymers obtained from the aforementioned crystalline form of ATBS.K according to the present invention (P4 / 5-A K 2a) is an equivalent comparative polymer P'4 / 5-A H and P'4 / 5-CEA K It can be seen that the FR is always lower than 2c~2e. This difference becomes increasingly pronounced as the molecular weight of the polymer increases.

[0445] Example 24: Measurement of resistance of AM / ATBS / AA(71 / 9 / 20) polymer solution to chemical degradation Resistance to chemical degradation was tested on polymers P6 and P'6 prepared in Example 15, following the procedure described in Example 21. Polymer P6-A K 2a and P'6-A H Figure 20 shows the results obtained after contacting the solution with iron contaminants for 24 hours.

[0446] The results of the chemical degradation of all polymers P6 are detailed in Table 11.

[0447] [Table 11]

[0448] The results shown in Figure 20 and Table 11 indicate that at each iron(II) concentration, polymer P6-A K 2a is an equivalent comparative polymer P'6-A H and P'6-CEA K This demonstrates that the viscosity reduction is less than that of 2c~2e.

[0449] Example 25: Measurement of filter ratio of hydrolyzed polymer solution after AM / ATBS (90 / 10 mol%) A filtration test was performed on the polymer prepared in Example 16 according to the procedure described in Example 20. The results are shown in Table 12.

[0450] [Table 12]

[0451] The results indicate that the polymer P7-A of the present invention has a higher molecular weight. K 2a is comparative polymer P'7-A H and P'7-CEA K It is shown to have a lower FR compared to FRs of 2c to 2e.

[0452] Example 26: Treatment of coal mine wastewater Polymer P1-A K 2a, P'1-A H , and P'1-CEA K Dissolve 2c to 2e in tap water to obtain an aqueous solution with a polymer concentration of 0.4% by weight relative to the total weight of the solution. Stir the two solutions with a mechanical stirrer at 500 rpm until the polymer is completely dissolved and a clear, homogeneous solution is obtained.

[0453] A series of coagulation tests will be conducted on coal mine wastewater with a solid content of 18.2% by weight.

[0454] Each solution is added to 200g of coal mine wastewater in an amount equivalent to the polymer input amount of 280g of polymer per ton based on the dry material standard of the coal mine wastewater, and then thoroughly mixed by hand until optimal flocculation and water release are observed.

[0455] The results are expressed as NWR (Net Water Release), which corresponds to the total amount of water recovered one hour after the coagulation test minus the amount of water induced during the process of incorporating the polymer aqueous solution into the suspension. The same NWR after 24 hours, which is a good indicator of the maximum amount of water released, is also calculated.

[0456] The results are shown in Table 13.

[0457] [Table 13]

[0458] The results of this experiment clearly demonstrate that by using ATBS, which is the crystalline form of ATBS.K according to the present invention, it is possible to obtain a polymer that is more effective in coagulating coal mining wastewater from coal mines.

[0459] Example 27: Treatment of red mud derived from the Bayer process Another series of tests were conducted on Bayer-derived red mud with a solid content of 22.8% by weight, using 740 g of polymer per ton based on the dry weight of the red mud, according to the protocol described in Example 26. The results are shown in Table 14.

[0460] [Table 14]

[0461] The results of this experiment clearly demonstrate that by using ATBS, the crystalline form according to the present invention, it is possible to obtain a polymer that is more effective in agglomerating red clay derived from the Bayer process.

Claims

1. A crystalline form of potassium 2-acrylamido-2-methylpropanesulfonate having a powder X-ray diffraction pattern that includes peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

2. 3293 cm －１ 、3075 cm －１ 、3000 cm －１ 、2979 cm －１ 、1655 cm －１ 、1625 cm －１ 、1550 cm －１ 、1405 cm －１ 、1209 cm －１ 、1190 cm －１ 、1162 cm[[ID=2I]] －１ 、1048 cm －１ 、979 cm －１ 、824 cm －１ 、803 cm －１ 、756 cm －１ 、633 cm －１ 、523 cm －１ (±8 cm －１ ) having a Fourier transform infrared spectrum including peaks at, a crystalline form of 2-acrylamido-2-methylpropanesulfonic acid potassium salt, ATBS.K according to claim 1.

3. A crystalline form of ATBS.K according to claim 1 or claim 2, characterized by having a minimum ignition energy of more than 500 mJ.

4. The crystalline form of ATBS.K according to any one of claims 1 to 3, characterized by exhibiting two thermal phenomena at 79.4°C and 207°C (±10°C) by differential scanning calorimetry.

5. A method for producing the crystalline form of ATBS.K according to any one of claims 1 to 4, comprising at least the following sequential steps: 1) Aqueous solution or aqueous suspension SA ２ To form 2-acrylamido-2-methylpropanesulfonic acid, aqueous solution SA １ and the step of mixing with at least one potassium salt base; 2) Suspension S １ To form the aqueous solution or aqueous suspension SA ２ The step of distilling at a pressure of 700 mbar or less; 3) The suspension S １ The solid-liquid is separated, and the suspension S obtained at the end of step 2) is obtained. １ The crystals of composition C １ A step of isolating it in that form.

6. The aqueous solution or aqueous suspension SA ２ The amount of ATBS.K in the aqueous solution or aqueous suspension SA ２ The method according to claim 5, characterized in that it is 10 to 90% by weight of the total weight.

7. Step 2) In the aqueous solution or aqueous suspension SA ２ The method according to claim 5 or claim 6, characterized in that the material is heated, preferably at a temperature of 5°C to 95°C.

8. The method according to any one of claims 5 to 7, characterized in that step 2) further comprises a cooling step, which is preferably carried out at a temperature of 5°C to 95°C.

9. The method according to any one of claims 5 to 8, characterized in that the temperature of the cooling step is reduced in a gradient of 0.1 to 8°C / hour.

10. The suspension S １ However, the suspension S １ The method according to any one of claims 5 to 9, characterized in that it contains 30 to 90% by weight of the crystalline form of ATBS.K based on the total weight.

11. The method according to any one of claims 5 to 10, characterized in that the potassium salt is selected from potassium hydroxide, potassium carbonate, potassium bicarbonate, and mixtures thereof.

12. A polymer obtained at least partially from the crystalline form of ATBS.K having a powder X-ray diffraction pattern that includes peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

13. A method for processing an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer at least partially obtained from a crystalline form of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

14. A method for agglomerating an aqueous suspension of solid particles, comprising contacting the suspension with at least one water-soluble polymer at least partially obtained from a crystalline form of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

15. A method for enhanced hydrocarbon recovery, comprising the following steps: a) A step of preparing an injection fluid containing at least one water-soluble polymer of 2-acrylamido-2-methylpropanesulfonic acid using water or brine; The 2-acrylamido-2-methylpropanesulfonic acid is, before polymerization, at least partially, a powder X-ray diffraction pattern having peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°, which is the crystalline form of ATBS.K, step; b) The step of injecting the injection fluid into the underground geological formation; c) A step of sweeping the underground geological formation using the injected fluid; d) A step of recovering the aqueous hydrocarbon mixture, Methods that include...

16. A fracturing fluid comprising at least an aqueous phase, a propping agent, and at least one water-soluble polymer at least partially obtained from the crystalline form of ATBS.K having a powder X-ray diffraction pattern including peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

17. A method for producing a crushed fluid according to claim 14, comprising adding at least one water-soluble polymer obtained at least partially from the crystalline form of ATBS.K to water or brine, wherein the water-soluble polymer is obtained before the formation of the crushed fluid: - In powder form, - Or in the form of a water-in-oil reversed-phase emulsion, - Or in the form of an aqueous or oil-based multiphase fine particle suspension, A method wherein the crystalline form of ATBS.K has a powder X-ray diffraction pattern that includes peaks at positions where 2θ (±0.1°) is 13.1°; 14.4°; 16.3°; 19.8°; 23.5°; 24.3°; 26.9°; 27.6°; 29.3°; 30.6°; 31.6°; 34.3°; 36.1°; 41.7°; 44.6°; 46.7°.

18. A hydraulic fracturing method for an unconventional underground oil or gas reservoir, comprising: producing the fracturing fluid described in claim 16; and injecting the fracturing fluid into the underground reservoir.

19. A method for reducing friction of a fracturing fluid in hydraulic fracturing operations of an unconventional underground oil or gas reservoir, comprising: producing the fracturing fluid described in claim 16; and injecting the fracturing fluid into the underground reservoir.

20. Use of the polymer according to claim 12 in any application selected from well drilling; well cementing; conformance, diversion; open, closed, or semi-closed circuit water treatment; fermentation broth treatment; sludge treatment; construction; paper or cardboard manufacturing; batteries; wood processing; hydraulic composition treatment; cosmetic preparation; detergent preparation; textile manufacturing; geothermal energy; diaper manufacturing; and agriculture.

21. Use of the polymer according to claim 12 as a coagulant, binder, absorbent, water remover, filler retainer, dehydrating agent, conditioning agent, stabilizer, fixative, film-forming agent, sizing agent, superplasticizer, clay inhibitor or dispersant.

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