Patent Application
20240301111
The invention pertains to liquid, radiation curable composition suitable for additive manufacturing processes.
A well-established process of fabricating complex polymeric three-dimensional structure using stereolithography (SLA) and/or digital light processing (DLP) is called Vat-photopolymerization 3D printing or additive manufacturing (AM).
SLA/DLP processes utilizes CAD data of three-dimensional (3D) objects, which are converted to thin 2D slices. These 2D slices data are fed to a computer which controls a radiation sources such as laser or a light projector. Based on the 2D data, the radiation source would trace the pattern on a liquid radiation curable resin contained in the vat, leaving a solidified thin cross section of the corresponding 3D object. A thin layer of curable resin would be coated on the solidified cross section and the radiation source traces another cross section, obtained from the computer, on the resin layer to solidify over the previous solid layer. The process is repeated layer-by-layer to complete the fabrication of a 3D object. The 3D object is generally not fully cured and called green body, which could be subjected to post-curing processes to attain the final mechanical and thermal properties. Photopolymer for Vat-photopolymerization 3D printing or additive manufacturing (AM) technology is progressing from prototyping towards fabrication of functional end-use parts. One of the major challenges in using SLA/DLP based AM for manufacturing functional parts is the lack of high strength, high temperature resistant, durable liquid curable resin. Resin products available in the market are unable to provide the synergy of high strength, high temperature resistance and durability. Some of the high-strength resin materials currently available do not show acceptable durability or weatherability.
For example, U.S. Pat. No. 8,501,033 B2 describes a high strength liquid curable composition for three-dimensional printing. According to the composition disclosed in this document, high modulus of 2 to 3 GPa Young's modulus is attained. However, this composition contains a mixture of free radical and cationic curable moieties. It is known that such systems involving cationic curing moieties lead to limited shelf stability of the resin.
Attempts have been made to obtain high strength liquid curable resin using higher loading of methacrylate bisphenol type epoxides and other methacrylate monomers. Such resin compositions are described in U.S. Pat. No. 7,232,646B2 or US20180194885A1. The document US20180194885A1 shows such a composition which attains increased tensile strength of 35 to 40 MPa and a high Tg of 80° C. Such mechanical properties are not sufficient to meet the need of high-strength industrial applications. It is well-known in radiation curing polymer chemistry, that methacrylates are slow curing compared with acrylates. Consequently, the use of methacrylates results in lower green body strength during the additive manufacturing process. Furthermore, these compositions have a high number of aromatic moieties, which are susceptible to weathering induced degradation.
U.S. Ser. No. 10/357,435B2 discloses compositions with relatively lower loading of methacrylate bisphenol type epoxides to attain high strength resins. However, the viscosity of these compositions is significantly higher than resins with higher loading of methacrylate. Such compositions with higher viscosity are prone to generate processing limitations and may not be suitable for additive manufacturing of high-resolution objects.
It is thus an object of the present invention to provide a radiation curable composition in which the disadvantages of the prior art are at least reduced, which yields high strength objects after curing, that is suitable for additive manufacturing applications, and that achieves good weatherability.
This object is achieved by a liquid, radiation curable composition with a viscosity of 1500 cps or lower, said composition comprising the following components:
It is preferred that the sum of components a) to f) equals 100 weight percent.
The composition according to the invention can further comprise component g) additives to enhance processability and/or fillers in an amount of 0.01 to 30 weight percent. If component g) is present then the sum of components a) to g) equals 100 weight percent.
Surprisingly it was found that the resin composition according to the invention attains objects with high strength, high temperature resistance and at the same time excellent durability or weatherability using a single cure free radical system.
After curing, mechanical properties of the resin composition such as Young's modulus are in the range of at least 2.5 GPa and up to 5 GPa. Ultimate tensile strength and elongation at break are in the range of 70 to 120 MPa and 3.5%-7% respectively. Ultimate tensile strength, elongation at break and Young's modulus are determined according to ASTM D638.
The resin composition also leads to excellent thermal properties after curing. Heat distortion temperature lies in the range of 115° C. to 125° C. and glass transition temperature Tg is at least 90° C. and can reach up to 300° C. Heat distortion temperature was determined according to ASTM D648. Glass transition temperature Tg was determined at the onset of storage modulus in a dynamic mechanical analysis according to ASTM E1640.
The term “(meth)acrylate group” means either a methacrylate group, an acrylate group or a mixture of both.
The unique ratio of components a) to d) in the resin composition according to the invention results in a radiation curable liquid resin with a viscosity that is suitable for 3D printing applications and thus enabling superior processability. The viscosity of the liquid, radiation curable composition according to the invention preferably ranges from 100 to 1500 cps, 200-1500 cps, more preferably 300-1500 cps and most preferably 400-1500 cps. Viscosity is determined by applying the rotation rheometer method at 25° C. and 10 Hz.
The at least two aromatic (meth)acrylate groups in component a) of the liquid, radiation curable composition according to the invention are preferably aromatic di(meth)acrylates.
It is further preferred that component a) of the liquid, radiation curable composition according to the invention is selected from the group consisting of di(meth) acrylate of bisphenol A, Bisphenol A glycerolate di(meth)acrylate, bisphenol A ethoxylate (1 EO/phenol) di(meth)acrylate, bisphenol A ethoxylate (2 EO/phenol) di(meth)acrylate, bisphenol A ethoxylate (4 EO/phenol) di(meth)acrylate, bisphenol A propoxylate (1 PO/phenol) di(meth)acrylate, bisphenol A propoxylate (2 PO/phenol) di(meth)acrylate, bisphenol A propoxylate (4 PO/phenol) di(meth)acrylate, bis(naphthol) di(meth)acrylate, bis(naphthol) ethoxylate (1 EO/naphthol) di(meth)acrylate, bis(anthrol) di(meth)acrylate, bis(anthrol) ethoxylate (1 EO/naphthol) di(meth)acrylate, as well as Bisphenol F di(meth)acrylate, bisphenol F ethoxylate (1 EO/phenol) di(meth)acrylate, bisphenol F ethoxylate (2 EO/phenol) di(meth)acrylate, bisphenol F ethoxylate (4 EO/phenol) di(meth)acrylate, bisphenol F propoxylate (1 PO/phenol) di(meth)acrylate, bisphenol F propoxylate (2 PO/phenol) di(meth)acrylate, bisphenol F propoxylate (4 PO/phenol) di(meth)acrylate or mixtures thereof.
The above preferred embodiments of component a) are obtainable by an addition reaction of an aromatic glycidyl group-containing compound and a (meth)acrylic acid, such as aromatic glycidyl ether. Alternatively, those substances can be obtained by an esterification reaction of an aromatic alcohol and (meth)acrylic acid.
The liquid, radiation curable composition according to the invention is preferably characterized in that the at least two (meth)acrylate groups in component b) are acryloxy unsaturated functional groups and that the alicyclic moiety is tricyclodecane or a derivative of tricyclodecane.
It is further preferred that the alicyclic moiety is selected from the group consisting of 4,8-Bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-carboxy-tricyclo[5.2.1.02,6] decane, 4-hydroxymethyl-8-methoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-8-methoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-methoxycarbonyl-tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-butoxycarbonyl tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-butoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-butoxycarbonyl-tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-pentoxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-pentoxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-9-pentoxycarbonyl tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-9-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane. Most preferably from the addition and/or esterification reaction of 4,8-Bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-carboxy-tricyclo[5.2.1.02,6] decane.
Component b) is preferably obtained from the addition and/or esterification reaction of 4,8-Bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-carboxy-tricyclo[5.2.1.02,6] decane, 4-hydroxymethyl-8-methoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-8-methoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-methoxycarbonyl-tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-butoxycarbonyl tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-butoxycarbonyl-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-butoxycarbonyl-tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-pentoxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-pentoxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-9-pentoxycarbonyl tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-9-vinyloxycarbonyl-tricyclo[5.2.1.02,6]decane with (meth)acrylic acid.
Most preferably component b) is obtained from the addition and/or esterification reaction of 4,8-Bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane, 4-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6]decane, 3-hydroxymethyl-8-carboxy-tricyclo[5.2.1.02,6] decane, 3-hydroxymethyl-9-carboxy-tricyclo[5.2.1.02,6] decane with (meth)acrylic acid.
Difunctional components are perceived to be brittle after curing and the prior art suggests the use of monofunctional components (see e.g. US20180194885A1) for high strength resins. Surprisingly it could by shown that the resin composition according to the invention yields high strength mechanical properties by incorporating difunctional components.
Component c) according to the invention comprises at least two (meth)acrylate groups and at least one urethane linkage. For example, compounds formed by reacting an aliphatic polyol, for example a diol, with an aliphatic multifunctional isocyanate, for example, a diisocyanate, and then end-capping with an aliphatic hydroxy-functional (meth)acrylate or by reacting with an aliphatic multifunctional isocyanate, for example, a diisocyanate, and then end-capping with an aliphatic hydroxy-functional (meth)acrylate. The aliphatic polyol may be aliphatic polyether polyol or aliphatic hydrocarbon polyol. The aliphatic polyether polyols or aliphatic hydrocarbon polyol may be ethylene glycol, propylene glycol, tripropylene glycol, 1,3- or 1,4-butanediol, neopentylglycol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol. The aliphatic hydrocarbon diol/polyol may be hydroxyl terminated, fully or partially hydrogenated 1,2-propylene, butadiene, pentene, hexene. The aliphatic multifunctional isocyanate may be trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate. The hydroxy-functional (meth) acrylate may be 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth) acrylate, pentanediol mono(meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth)acrylate, glycerol mono (meth)acrylate, glycerol di (meth)acrylate, cyclohexane dimethanol mono(meth)acrylate, neopentyl glycol mono(meth) acrylate, trimethylolpropane di(meth)acrylate, and pentaerythritol tri(meth)acrylate. More preferably the aliphatic monomer, oligomer or polymer of component c) is obtained from the reaction of 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate.
Component d) could be a monomer or oligomer with at least one, e.g. with one, two or three (meth)acrylate groups having a terminal hydroxyl moiety. Examples for component d) with two or three (meth)acrylate groups are glycerol di (meth)acrylate, trimethylolpropane di(meth)acrylate, and pentaerythritol tri(meth)acrylate. According to the invention it is preferred that component d) is a monomer with one (meth)acrylate group having a terminal hydroxyl moiety. It is further preferred that the one (meth)acrylate group in component d) is a monofunctional acryloxy unsaturated functional group. Preferably component d) is an aliphatic monomer.
More preferably component d) is selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth) acrylate, pentanediol mono(meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth)acrylate, glycerol mono (meth)acrylate, cyclohexane dimethanol mono(meth)acrylate, neopentyl glycol mono(meth) acrylate or combinations thereof. In general component d) can be obtained by an addition reaction of a glycidyl group-containing compound and a (meth)acrylic acid, such as alkyl glycidyl ether and glycidyl (meth) acrylate and compounds which are obtainable by an esterification reaction of aliphatic alcohol and (meth)acrylic acid.
Component e) is preferably a free radical type photoinitiator selected from the group consisting of phosphine oxide-type photoinitiators and aromatic ketone-type photoinitiators or mixtures thereof.
The phosphine oxide-type of photoiniators may be a benzoyl diaryl phosphine oxide photoiniator, such as (2,4,6-trimethylbenzoyl) diphenylphosphine oxide or other phosphine oxide-type photo initiator, such as bis(2,4,6-trimethylbenzoyl)phenyphosphine or bis (2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and mixtures of phosphine oxide-type free radical photoinitiators. Examples of aromatic ketone-type free radical photoinitiators that may be used in the present invention include: 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, dimethoxyphenyl acetophenone, 2-methyl-1-4-methyl morpholinopropanone-1,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecyl-phenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-2(2-hydroxy-2-propyl)-ketone. Also, the photoinitiator may be a mixture of phosphine oxide-type free radical photoinitiators and aromatic ketone type free radical photoinitiators. More preferably component e) is selected from the group consisting of benzoyl diaryl phosphine oxide photoiniator, such as (2,4,6-trimethylbenzoyl) diphenylphosphine oxide or other phosphine oxide-type photo initiator, such as bis(2,4,6-trimethylbenzoyl)phenyphosphine or bis (2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.
Component f) can be any pigment that is known to the person skilled in the art. Preferably component f) is an organic or inorganic black pigment, examples of organic black are carbon black or aniline black and examples of inorganic black are titanium black and iron oxide.
Preferred embodiments of the liquid, radiation curable composition according to the invention:
In one preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
In another preferred embodiment of the liquid, radiation curable composition according to the invention, the composition has a viscosity in the range of 100 cps to 1500 cps and it comprises the following components:
The liquid, radiation curable composition according to the invention is a one-part system that requires no mixing of components immediately before the printing process. It is preferably curable through free radical curing in a single curing mechanism. More preferably the liquid, radiation curable composition according to the invention is curable by techniques selected from the group consisting of actinic radiation curing, electron beam curing, heat curing or combinations thereof.
The inventive liquid, radiation curable resin composition has a specific ratio of aliphatic to aromatic components for achieving high performance and durability or weatherability. Preferably the weight ratio of aromatic monomers or oligomers in the composition to aliphatic monomers or oligomers ranges from 5:95 to 50:50. More preferably the weight ratio of aromatic monomers or oligomers to aliphatic monomers or oligomers ranges from 5:95 to 30:70 (weight % aromatic:aliphatic).
Surprisingly it was also found that the mechanical properties and cure speed can be balanced by a unique ratio of methacrylate to acrylate in the liquid, radiation curable composition according to the invention. Preferably the weight ratio of methacrylate monomers or methacrylate oligomers to acrylate monomers or acrylate oligomers ranges from 80:20 to 20:80. More preferably the weight ratio of methacrylate monomers or methacrylate oligomers to acrylate monomers or acrylate oligomers ranges from 80:20 to 50:50 (weight % methacrylate:acrylate).
The resin composition according to the invention is especially suitable to be used in an additive manufacturing process or jetting process or a combination of both.
Such additive manufacturing processes or jetting processes for making a three-dimensional object are known in the art and generally comprising the steps of
Preferably the liquid, radiation curable composition is used in an additive manufacturing or jetting process comprising the repeated steps of depositing or layering and irradiating the composition to form a three-dimensional object, more preferably the composition is used in an additive manufacturing or jetting process comprising the repeated steps of depositing or layering, heating, degassing and irradiating, the composition to form a three-dimensional object.
The invention also encompasses a three-dimensional object generated by an additive manufacturing process using a liquid, radiation curable composition according to the invention. Such a three-dimensional object satisfies the criteria for a high strength resin and exhibits a Young's modulus of at least 2.5 GPa and up to 5 GPa, an ultimate tensile strength of at least 70 MPa and up to 120 MPa. The glass transition temperature Tg is at least 90° C. and can reach up to 300° C. Ultimate tensile strength, and Young's modulus are measured according to ASTM D638. Glass transition temperature Tg is determined at the onset of storage modulus in a dynamic mechanical analysis according to ASTM E1640.
The three-dimensional object generated by an additive manufacturing process using a liquid, radiation curable composition according to the invention does not only yield a high strength material it also exhibits excellent ageing and weatherability properties.
Mechanical properties such as ultimate tensile strength and elongation at break are maintained even after exposure to UV radiation, temperature and moisture for 200 hours and the change in ultimate tensile strength is less than 50% even after exposure to UV radiation, temperature and moisture for 800 hours.
Thus, the present invention encompasses a three-dimensional object generated by an additive manufacturing process using a liquid, radiation curable composition according to the invention said three-dimensional object retains at least 50% of its ultimate tensile strength after being subjected to aging according to ASTM G154 for 800 hours.
The combination of both, high strength and good weatherability has not been reported in the art. The mechanical, thermal and durability or weatherability properties of the fully cured three-dimensional object generated from the inventive single cure low viscosity, three-dimensional printable, radiation curable liquid resin formulations are significantly better than prior art products. The resin compositions according to the invention can be used for SLA/DLP based 3D printing/additive manufacturing of high strength, temperature stable automotive and industrials thermoset components.
The subject matter of the present invention is illustrated in more detail in the following examples, without any intention that the subject matter of the present invention be restricted to these examples.
The resin is prepared by mixing the chemical ingredients as mentioned in the tables in a mixing equipment. The thus prepared resin mixture is used to generate tensile specimen through DLP 3D printing process.
Ultimate tensile strength, elongation at break and Young's modulus were determined according to ASTM D638.
Glass transition temperature Tg was determined at the onset of storage modulus in a dynamic mechanical analysis according to ASTM E1640.
The viscosity of composition 1 measured by rotation rheometer method at 25° C. (10 Hz) was 800 cps.
The viscosity of composition 2 measured by rotation rheometer method at 25° C. (10 Hz) was 600 cps.
The ultimate tensile strength of the tensile specimen is above 70. Elongation at break lies in the required range of 3.5-7%. Modulus is greater than 2.5 GPa and reaches 2.96 GPa.
The viscosity of composition 3 measured by rotation rheometer method at 25° C. (10 Hz) was 671 cps.
The ultimate tensile strength of the tensile specimen is above 70 and reaches 84.1 MPa. Elongation at break lies in the targeted range of 3.5-7%. Modulus is greater than 2.5 GPa and reaches 2.99 GPa.
The viscosity of composition 4 measured by rotation rheometer method at 25° C. (10 Hz) was 792 cps.
The ultimate tensile strength of the tensile specimen is above 70 and reaches 78 MPa. Elongation at break lies in the required range of 3.5-7%. Modulus is greater than 2.5 GPa and reaches 3.09 GPa.
The ultimate tensile strength of the tensile specimen is above 70 MPa. Elongation at break lies within the targeted range of 3.5-7%. Modulus is greater than 2.5 GPa and reaches 2.79 GPa.
The ultimate tensile strength of the tensile specimen is above 70 MPa and reaches 75 MPa. Elongation at break lies within the targeted range of 3.5-7%. Modulus is greater than 2.5 GPa and reaches 3.47 GPa.
Composition 7 is a comparative example with component a) exceeding 50 weight % of the composition. This leads to a viscosity of 3570 cps determined by rotation rheometer method at 25° C. (10 Hz).
Properties of tensile specimen after printing of composition 7 in DLP 3D printing process could not be measured. The material was too brittle for testing and the viscosity of the composition is beyond the desirable range for printing. Going beyond the weight range of 50 weight percent of component a) according to the invention impacts the viscosity of the composition significantly.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20210550.8 | Nov 2020 | EP | regional |
| 21157664.0 | Feb 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/082241 | 11/19/2021 | WO |
