Photocurable polymer composition

Abstract

The present invention relates to a polymer formulation for three-dimensional (3D) printing of articles by stereolithography, the formulation comprising a functionalized polymer. The present invention further relates to a lithographic method for forming a 3D object incorporating the aforementioned polymer formulation.

Description

Technical Field

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 007,454, filed on April 9, 2020, and European Patent Application Publication No. 20185769.5, filed on July 14, 2020, the entire contents of each of these applications are hereby incorporated by reference herein for all purposes.

[0002] The present invention relates to a polymer formulation for three-dimensional (3D) printing of articles by stereolithography, the formulation comprising a functionalized polymer and a crosslinking agent. The present invention further relates to a lithography method for forming a 3D object incorporating the aforementioned polymer formulation.

Background Art

[0003] Polymer compositions are commonly used, for example, to manufacture articles for the automotive and aerospace industries, such as engine parts, and articles in the healthcare industry, such as implantable devices and dental prosthetics. These articles must exhibit good mechanical properties after manufacture, and they must retain a sufficient percentage of these properties over time, especially at their use temperature (sometimes above 150°C).

[0004] Lithography processes for the photofabrication of 3D articles from polymer materials have recently gained popularity due to their relative speed and simplicity. Generally, lithography processes involve the use of light, such as UV irradiation, to locally cure a polymerizable formulation at specific locations. The local curing enables the manufacture of three-dimensional articles.

[0005] Lithography processes generally use a polymerizable formulation that is liquid in order to obtain parts with good resolution. Polymerizable formulations that are liquid at room temperature are easier to use in the printing process, but they generally result in articles with mediocre mechanical properties and thermal stability.

[0006] The polymeric materials used in the lithography process need to be in a liquid state under the printing conditions. For certain polymeric materials such as high-performance polymers, this means that they need to be heated above the glass transition temperature (Tg) or the melting temperature (Tm). They also need to have functional groups that are photopolymerizable or crosslinkable, i.e., functional groups that react during the printing process when irradiating the layer of the polymerizable formulation. One of the challenges in applying the lithography method to high-performance polymers is that the material needs to maintain thermal stability at high temperatures while avoiding thermal polymerization of the photopolymerizable functional groups.

[0007] Another challenge is the identification of effective photopolymerizable groups and the synthetic methods for adding them to the materials to be printed to make the polymeric materials photopolymerizable.

[0008] Another challenge in the identification of valuable polymerizable formulations used in the lithography process is that it must be possible to manufacture 3D articles that exhibit good mechanical properties after photolithography and substantially retain these mechanical properties after exposure to high temperatures, for example above 150 °C.

[0009] The polymerizable formulation of the present invention provides a solution well-suited for 3D printing processes that can be carried out, for example, at room temperature or higher temperatures.

[0010] International Publication No. WO 2020 / 074332 A1 (Solvay) relates to a polymer formulation (F) containing a low molecular weight polymer having a photopolymerizable end group. Due to their low molecular weight, i.e., short chain length, these polymers have a high concentration of photopolymerizable groups and exhibit good printability.

[0011] The paper "Solvent-stable UV-cured acrylic polysulfone membranes" (2016) by Mehmood Mian Farrukh et al. concerns the effect of the presence of acrylic resin on polysulfone-based membranes prepared by UV curing of the polymer dope followed by a non-solvent induced phase separation process.

[0012] The paper "Synthesis, preparation and characterization of UV-cured methacrylated polysulfone-based membranes" (2015) by M. Sangermano et al. concerns a two-step method for the preparation of crosslinked polysulfone membranes, including non-solvent induced phase separation (NIPS) and a UV curing process.

[0013] These two papers also do not describe the poly(aryl ether sulfone) (PAES) polymer (P) of the present invention, nor the use of a polyfunctional photo-crosslinking agent that forms a polymer network with the polymer (P) after printing and curing due to the presence of photocurable groups on the polymer (P).

[0014] The polymerizable formulation of the present invention provides a solution suitable for high-temperature 3D printing processes, and also enables the production of 3D printed articles from a high molecular weight polymer formulation having a low concentration of photopolymerizable groups in order to achieve good printability and obtain 3D printed parts having excellent mechanical properties.

Summary of the Invention

[0015] The present invention relates to a polymer formulation (F) comprising a polymer (P) which is a poly(aryl ether sulfone) (PAES) polymer containing at least one, preferably two, photopolymerizable end groups in combination with a polyfunctional photo-crosslinking agent.

[0016] This polymer formulation (F) can be used, for example, in a photolithography process. In particular, the formulation (F) of the present invention can be incorporated into a lithography process in which light is used to cure the functionalized polymer. The formulation (F) of the present invention can be changed to a liquid state at a temperature below or above the Tg of the polymer (P) without visible change, and then cured by irradiation with UV light to produce a high thermal property material having a high Tg, high mechanical properties, and high thermal stability. The formulation (F) of the present invention can be effectively used in a 3D printing lithography process.

[0017] The present invention also relates to a method of manufacturing a three-dimensional (3D) article using an additive manufacturing system, comprising: - providing a polymer formulation (F) according to the present invention; - printing a layer of the 3D article from the polymer formulation (F); and a method comprising the steps of.

[0018] According to another embodiment of the present invention, the printing step comprises irradiating the polymer formulation (F) with UV light or visible light. The UV light can be, for example, laser light.

[0019] The present invention also relates to the use of a polymer formulation (F) for the production of at least partially obtained 3D articles and 3D objects by stereolithography (SLA) according to the method described above.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention relates to a formulation (F) comprising a PAES polymer (P) that can be used, for example, in a lithography process for the photolithography of three-dimensional (3D) articles.

[0021] Stereolithography is an additive manufacturing (AM) process that functions by aligning the focus of light, such as ultraviolet (UV) light or visible light, with a bath of a crosslinkable photopolymer resin. Complex 3D structures can then be built in a layer-by-layer manner.

[0022] The polymer (P) described in this specification can be 3D printed for manufacturing articles in combination with a crosslinking agent, for example, using stereolithography technology (SLA), inkjet technology, direct ink writing (DIW), or digital light processing (DLP).

[0023] The present invention relates to a polymer formulation (F) comprising one kind of poly(aryl ether sulfone) (PAES) polymer (P), wherein the polymer (P) is functionalized. More precisely, the polymer (P) contains at least one end group of formula (M1) or (M2):

Chemical formula

[0024] The polymer (P) preferably contains two end groups of formula (M1) or (M2), more preferably two end groups of formula (M1), and even more preferably two end groups of formula (M1) where R 2 is H.

[0025] According to the present invention, the number average molecular weight (Mn) of the polymer (P) is at least 12,000 g / mol, at least 13,000 g / mol, at least 14,000 g / mol, at least 15,000 g / mol, at least 17,000 g / mol, or at least 20,000 g / mol when measured by gel permeation chromatography (GPC) using methylene chloride as the mobile phase and polystyrene standards. Preferably, the number average molecular weight (Mn) of the polymer (P) is less than 50,000 g / mol, or less than 40,000 g / mol.

[0026] The formulation (F) containing the functionalized polymer (P) of the present invention can be used in a photolithography process. In particular, the polymer (P) and the polymer formulation (F) of the present invention can be incorporated into a lithography process in which light is used to cure the functionalized polymer.

[0027] The crosslinking ability of the formulation of the present invention can be evaluated by rheology. When the formulation (F) of the present invention is printed and irradiated with light such as UV light or visible light, it changes from a liquid to a solid. The change can be measured with a rotational rheometer. The transition from a liquid resin to a solid appears as an increase in the storage modulus G' and the loss modulus G''. The crossover of G' and G'' approximates the gel point, which means the conversion from a liquid to a gel during network formation. The gel point is an important engineering parameter for achieving a high-quality printed structure. By measuring G' of the formulation, the rigidity of the printed part can be evaluated, and thus the ability to support the next layer of the printed resin can be evaluated. The crossover of G' and G'' gives an indication of the crosslinking rate and the liquid-solid transition time.

[0028] In addition to the photopolymerizable (or crosslinkable) polymer (P), the formulation (F) of the present invention - at least one polyfunctional acrylate, and - at least one solvent, and - optionally at least one photoinitiator, and - optionally at least one blocker also contains.

[0029] The formulation (F) of the present invention is preferably a liquid. For example, the formulation (F) is a liquid at room temperature or above.

[0030] The polyfunctional acrylate is added to the formulation (F) as a crosslinking agent. That is, due to the presence of photopolymerizability on the polymer (P), a high molecular weight network is formed with the polymer (P) after printing and curing.

[0031] According to the present invention, a photoinitiator is a compound added to a formulation to convert absorbed light energy, UV or visible light, into chemical energy in the form of initiating species, such as free radicals or cations, among other things.

[0032] According to the present invention, a blocker is a compound added to capture unused radicals generated by a photoinitiator or to absorb a part of the incident UV energy. This compound enables improvement in the dimensional accuracy of the parts to be manufactured.

[0033] The polymer (P) described in the present invention is functionalized with a functional group, which is (meth)acrylate moiety (M1) and / or styrene (M2). The functional group is introduced as a post-polymerization modification, for example, as "terminal functionalization" at at least one end of the polymer chain, such as both ends of the polymer chain.

[0034] The formulation (F) of the present invention can contain two or more polymers (P), for example, two or three different polymers (P).

[0035] Poly(aryl ether sulfone) (PAES) P preferably has the following formula (L): [Chemical formula] [ In the formula, - Each R 1 is independently selected, for each aromatic ring, from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium; - Each i is independently zero or an integer from 1 to 4 for each aromatic ring; - T is a bond, -CH2-; -O-; -SO2-; -S-; -C(O)-; -C(CH3)2-; -C(CF3)2-; -C(=CCl2)-; -C(CH3)(CH2CH2COOH)-; -N=N- ;- R a C=CR b -(each R a and R b is independently of one another hydrogen, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C6-C18 aryl group 、 -(CH2) where m is an integer from 1 to 6 m - and -(CF2) m - 、 a straight-chain or branched aliphatic divalent group having up to 6 carbon atoms , or (which is a combination thereof) selected from the group consisting of of a PAES having a repeating unit (R PAES ).

[0036] In some embodiments, the polymer (P) of the present invention is - at least a repeating unit (R PAES ) of formula (L): [Chemical formula] and - at least one end group of formula (M): [Chemical formula] wherein, - each R 1 is independently of each aromatic ring selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium; - each i is independently of each aromatic ring zero or an integer from 1 to 4; - T is a bond, -CH2-; -O-; -SO2-; -S-; -C(O)-; -C(CH3)2-; -C(CF3)2-; -C(=CCl2)-; -C(CH3)(CH2CH2COOH)-; -N=N- ;- R a C=CR b -(each R a and R b is, independently of one another, hydrogen, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C6-C18 aryl group 、 -(CH2) where m is an integer from 1 to 6 m -and -(CF2) m - 、 a linear or branched aliphatic divalent group having up to 6 carbon atoms , or which are combinations thereof selected from the group consisting of ; - R 2 is H or CH3.

[0037] In some embodiments, the repeating unit (R PAES ) follows the following formula (L’):

Chemical formula

[0038] In some embodiments, the end groups of the polymer (P) follow the following formula (M’):

Chemical formula

[0039] According to one embodiment, i is zero for each R 1 . In other words, according to this embodiment, - the repeating unit (R PAES ) is the following formula (L’’):

Chemical formula

[0040] In some embodiments, P is a PAES having at least 50 mol% (based on the total number of moles in the polymer) of repeating units of formula (L), (L') or (L''), and contains at least one end group of formula (M), (M') or (M'').

[0041] In some embodiments, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeating units in the polymer (P) (based on the total number of moles in the polymer) are repeating units of formula (L), (L') or (L''), and P contains at least one end group of at least one of formula (M), (M') or (M''), for example, two end groups of formula (M), (M') or (M''). PAES ) and P contains at least one end group of at least one of formula (M), (M') or (M''), for example, two end groups of formula (M), (M') or (M'').

[0042] According to one embodiment of the present invention, P is a PAES in which T is selected from the group consisting of a bond, -SO2-, and -C(CH3)2-.

[0043] According to another embodiment of the present invention, P is at least 50 mol% (based on the total number of moles in the polymer) of the formula: [Chemical formula] (wherein R 1 and i are as described above) and is a PAES having a repeating unit selected from the group consisting of.

[0044] According to this embodiment, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeating units in the polymer (P) (based on the total number of moles in the polymer) are repeating units of the formula (L-A), (L-B), and / or (L-C) (R PAES ), and P contains at least one end group of at least one of the formulas (M), (M') or (M''), for example, two end groups of at least one of the formulas (M), (M') or (M'').

[0045] According to one embodiment, P is a PAES in which T is a bond. In other words, P is a functionalized poly(biphenyl ether sulfone) (PPSU).

[0046] According to one embodiment, P is - At least 50 mol% of the repeating units (mol% is based on the total number of moles in the polymer) are repeating units of the formula (L-A) (R PPSU ):

Chemical formula

Chemical formula

[0047] The polymer (P) of the present invention may be a homopolymer or a copolymer. When it is a copolymer, it can be a random, alternating or block copolymer.

[0048] In some embodiments of the present invention, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeating units in the polymer (P) are repeating units (R PPSU ) of formula (L-A), and P contains at least one end group of at least one of formula (M), (M') or (M''), for example two end groups of at least one of formula (M), (M') or (M'').

[0049] When the polymer (P) is a poly(biphenyl ether sulfone) (PPSU) copolymer, it has repeating units (R* PPSU ) different from the repeating units (R PPSU ), for example repeating units of formula (L-B) and / or formula (L-C) as described above, and / or repeating units of formula (L-D):

Chemical formula

[0050] The poly(biphenyl ether sulfone) (PPSU) polymer can be prepared by any method known in the art. This can be obtained, for example, by the condensation of 4,4'-dihydroxybiphenyl (biphenol) and 4,4'-dichlorodiphenyl sulfone in the presence of a base. The reaction of the monomer units occurs by nucleophilic aromatic substitution with the elimination of one unit of hydrogen halide as the leaving group. However, it should be noted that the structure of the resulting poly(biphenyl ether sulfone) does not depend on the nature of the leaving group. PPSU is then modified after polymerization to introduce a functional group at at least one end of the polymer chain. The functional group is acrylate, alkyl acrylate, or styrene.

[0051] According to one embodiment, P is a PAES in which T is -C(CH3)2-. In other words, P is a functionalized polysulfone (PSU).

[0052] According to one embodiment, P is - At least 50 mol% of the repeating units are repeating units of formula (L-B) (R PSU )(mol% is based on the total number of moles in the polymer):

Chemical formula

Chemical formula

[0053] In some embodiments of the present invention, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeating units in the polymer (P) are repeating units of formula (L-B) (R PSU ), and P contains at least one end group of at least one of formula (M), (M') or (M''), for example two end groups of at least one of formula (M), (M') or (M'').

[0054] When the polymer (P) is a polysulfone (PSU) copolymer, it has repeating units (R PSU ) different from the repeating units (R* PSU) For example, it may be composed of repeating units of the formulas (L-A), (L-C) and / or (L-D) described above in full.

[0055] According to one embodiment, P is a PAES in which T is -SO2-. In other words, P is a functionalized polyethersulfone (PES).

[0056] According to one embodiment, P is - At least 50 mol% of the repeating units are repeating units of the formula (L-C) (R PES ) (mol% is based on the total number of moles in the polymer):

Chemical formula

Chemical formula

[0057] According to one embodiment of the present invention, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeating units in the polymer (P) are repeating units of the formula (L-C) (R PES ), and P contains at least one end group of at least one of the formulas (M), (M') or (M''), for example two end groups of at least one of the formulas (M), (M') or (M'').

[0058] When the polymer (P) is a polyethersulfone (PES) copolymer, it has repeating units (R PESU ) different from the repeating units (R* PESU ), for example, it may be composed of repeating units of the formulas (L-A), (L-B) and / or (L-D) all described above.

[0059] Polyfunctional acrylate According to the present invention, the polyfunctional acrylate is a compound that is specifically added to the formulation (F) as a crosslinking agent, that is, to form a high molecular weight network with the polymer (P) after printing and curing due to the presence of photocurable groups on the polymer (P).

[0060] In some embodiments, the polyfunctional acrylate used in the formulation (F) of the present invention is trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxytriacrylate, trimethylolpropane propoxytriacrylate, pentaerythritol triacrylate (PETA), glyceryl propoxytriacrylate (GPTA), di(trimethylolpropane) tetraacrylate, glycerol propoxylate triacrylate, pentaerythritol tetraacrylate, 1,3,5-triacryloylhexahydro-1,3,5-triazine , B Selected from the group consisting of trimethylolpropane ethoxylate triacrylate, trimethylolpropane trimethacrylate, tris[2-(acryloyloxy)ethyl] isocyanurate, and mixtures thereof.

[0061] In some embodiments, the polyfunctional acrylate used in the formulation (F) of the present invention is of biological origin, for example, of castor oil origin.

[0062] The polyfunctional acrylate used in the formulation (F) of the present invention is preferably according to formula (I):

Chemical formula

Chemical formula

[0063] The polyfunctional acrylate crosslinking agent used in the formulation (F) of the present invention more preferably follows formula (III):

Chemical formula

[0064] The concentration of the polyfunctional acrylate in the formulation (F) may be at least 0.05% by weight, for example 0.05 - 30% by weight, for example 0.1% - 25% by weight, 0.2 - 20% by weight, or 0.5 - 15% by weight, based on the total weight of the formulation (F).

[0065] Solvent The concentration of the solvent may be 1 - 80% by weight, for example 2 - 75% by weight, 5 - 70% by weight or 10 - 65% by weight, based on the total weight of the formulation (F).

[0066] According to an embodiment of the present invention, the solvent is selected from the group consisting of N - methylpyrrolidone (NMP), N,N - dimethylformamide (DMF), N,N - dimethylacetamide (DMAC), 1,3 - dimethyl - 2 - imidazolidinone, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), and sulfolane.

[0067] Preferably, the solvent is a polar aprotic solvent. Preferably, the solvent is selected from the group consisting of N - methylpyrrolidone (NMP), dimethylacetamide (DMAc or DMA), N - cyclohexyl - 2 - pyrrolidone (CHP) and dimethyl sulfoxide (DMSO).

[0068] Photoinitiator In some embodiments, formulation (F) further comprises a photoinitiator. A photoinitiator is a compound that is added to the formulation, inter alia, to convert absorbed light energy, UV or visible light, into chemical energy in the form of initiating species, such as free radicals or cations. Based on the mechanism by which the initiating radicals are formed, photoinitiators are generally divided into two classes: - Type I photoinitiators undergo unimolecular bond cleavage upon irradiation to generate free radicals, - Type II photoinitiators undergo a bimolecular reaction in which the excited photoinitiator interacts with a second molecule (co-initiator) to generate free radicals.

[0069] The concentration of the photoinitiator in formulation (F) can be from 0.05 to 10% by weight, such as from 0.1 to 5% by weight, from 0.2 to 4% by weight or from 0.5 to 3% by weight, based on the total weight of formulation (F).

[0070] According to certain embodiments of the present invention, the photoinitiator is - Acetophenone - Anisoin - Anthraquinone - Anthraquinone-2-sulfonic acid, sodium salt monohydrate - (Benzene)tricarbonylchromium - Benzyl - Benzoin - Benzoin ethyl ether, benzoin isobutyl ether, benzoin methyl ether and benzophenone - 3,3’,4,4’-Benzophenone tetracarboxylic dianhydride - 4-Benzoylbiphenyl - 2-Benzyl-2-(dimethylamino)-4’-morpholinobutyrophenone - 4,4’-Bis(diethylamino)benzophenone - 4,4’-Bis(dimethylamino)benzophenone - Camphorquinone - 2-Chlorothioxanthen-9-one - (Cumene)cyclopentadienyliron(II) hexafluorophosphate - Dibenzoselenone - 2,2-Diethoxyacetophenone - 4,4’-Dihydroxybenzophenone - 2,2-Dimethoxy-2-phenylacetophenone - 4-(Dimethylamino)benzophenone - 4,4’-Dimethylbenzyl - 2,5-Dimethylbenzophenone - 3,4-Dimethylbenzophenone - Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methylpropiophenone and blend (e.g., 50 / 50 blend) - 4’-Ethoxyacetophenone - 2-Ethylanthraquinone - Ferrocene - 3’-Hydroxyacetophenone, 4’-hydroxyacetophenone, 3-hydroxybenzophenone and 4-hydroxybenzophenone - 1-Hydroxycyclohexyl phenyl ketone - 2-Hydroxy-2-methylpropiophenone - 2-Methylbenzophenone or 3-methylbenzophenone - Methyl benzoylformate - 2-Methyl-4’-(methylthio)-2-morpholinopropiophenone - Phenanthrenequinone - 4’-Phenoxyacetophenone - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide - Thioxanthen-9-one - Triarylsulfonium hexafluoroantimonate salt, mixed, 50% in propylene carbonate - Triarylsulfonium hexafluorophosphate salt, mixed, 50% in propylene carbonate, and - Mixtures thereof selected from the group consisting of.

[0071] Preferably, the photoinitiator is selected from the group consisting of 2,2-dimethoxy-2-phenylacetophenone (DMPA), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0072] Blocker In some embodiments, formulation (F) further contains a blocker. The blocker is a compound added to the formulation to (i) capture a predetermined amount of radicals formed by the photoinitiator during irradiation with UV light, (ii) capture unused radicals that may be present after the UV irradiation source is switched off, and / or (iii) absorb a portion of the energy carried to the system during UV irradiation.

[0073] The concentration of the blocker in formulation (F) can be 0.05 to 10% by weight, such as 0.1 to 5% by weight, 0.2 to 4% by weight, or 0.5 to 3% by weight, based on the total weight of formulation (F).

[0074] According to certain embodiments of the present invention, the blocker is - 2-Hydroxy-4-methoxybenzophenone (oxybenzene) - 1-(4-Methoxyphenyl)-3-(4-tert-butylphenyl)propane-1,3-dione (avobenzone) - Disodium 2,2'-(1,4-phenylene)bis(6-sulfo-1H-benzimidazole-4-sulfonate) (bisdisulzole disodium) - Hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (diethylamino hydroxybenzoyl hexyl benzoate) - Menthylo-aminobenzoate (menthyl anthranilate) - 2,2’-[6-(4-Methoxyphenyl)-1,3,5-triazine-2,4-diyl]bis{5-[(2-ethylhexyl)oxy]phenol} (bemotrizinol) - 2,4-Dihydroxybenzophenone - 2,2’,4,4’-Tetrahydroxybenzophenone - 4-Hydroxy-2-methoxy-5-(oxo-phenylmethyl)benzenesulfonic acid (sulisobenzone) - 2,2’-Dihydroxy-4,4’-dimethoxybenzophenone - 5-Chloro-2-hydroxybenzophenone - (2-Hydroxy-4-methoxyphenyl)-(2-hydroxyphenyl)methanone (dioxybenzone) - 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene - Sodium 2,2’-dihydroxy-4,4’-dimethoxybenzophenone-5,5’-disulfonate - (2-Hydroxy-4-methoxyphenyl)(4-methylphenyl)methanone (Mexenone) - (2-Hydroxy-4-octyloxy-phenyl)-phenyl-methanone (octabenzone) - 2-(1,2,3-Benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-(2,2,4,6,6-pentamethyl-3,5-dioxa-2,4,6-trisilaheptan-4-yl)propyl]phenol (drometrizole trisiloxane) - terephthalylidene dicamphor sulfonic acid (ecamsule) - 2-Ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate (octocrylene) - Diethylhexyl butamido triazone (isotrizinol) - 2-Ethoxyethyl 3-(4-methoxyphenyl)propenoate (cinoxate) - Isopentyl 4-methoxycinnamate (amylogallate) - 2,2'-Methylenebis[6-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol] (bis- octrizole) - 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol - 2,2'-Methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol] - 2-Hydroxy-4-(octyloxy)benzophenone - 2-Ethylhexyl 2-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-hydroxyphenoxy]ethyl ester - 2-tert-Butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol - 2-(2-Hydroxy-5-methylphenyl)benzotriazole - 2,4-Dinitrophenylhydrazine - N-(4-Ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine - Hexadecyl 3,5-bis-tert-butyl-4-hydroxybenzoate - 2-Ethyl-2'-ethoxy-oxalanilide, and - mixtures thereof is selected from the group consisting of

[0075] Preferably, the blocker is selected from the group consisting of avobenzone and 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene.

[0076] Optional components The formulation (F) of the present invention may contain at least one additive selected from the group consisting of fillers such as silica, antioxidants, antibacterial compounds, and antistatic compounds. The additives can be chemically inert species such as carbon black, silica (e.g., microsilica particles) and carbon nanotubes.

[0077] Manufacturing process of 3D articles The present invention also relates to a method for manufacturing a 3D article with an additive manufacturing system, comprising: - providing a polymer formulation (F) as described above; - printing a layer of the 3D article from the polymer formulation (F); - optionally, curing the 3D article at a temperature in the range of 50 to 450 °C, preferably 100 to 300 °C, more preferably 120 to 180 °C. The invention relates to a method comprising these steps.

[0078] According to one embodiment, the printing step comprises irradiating the polymer formulation (F), for example a layer of such a formulation (F) deposited on a printing surface, with UV light. The layer preferably has a size in the range of 5 μm to 300 μm, for example 20 μm to 150 μm.

[0079] The UV light can be, for example, laser light. The irradiation is preferably of sufficient intensity to cause substantial curing of the polymer formulation (F), for example a layer of such a formulation (F). Also, the irradiation is preferably of sufficient intensity to cause adhesion of the layer of the polymer formulation (F).

[0080] According to another embodiment of the present invention, a method for manufacturing a 3D article with an additive manufacturing system comprises: - providing a polymer formulation (F) as described above; - printing a layer of the 3D article from the polymer formulation (F) by: a) coating a layer of the formulation (F) onto a surface; b) irradiating the layer with UV light; c) coating the layer of the formulation (F) onto the previously irradiated layer; d) irradiating the layer with UV light; and e) repeating steps c) and d) a sufficient number of times to produce the 3D article. The method includes these steps.

[0081] According to one embodiment, the polymer formulation (F) is at room temperature during the process. Instead, the formulation can also be heated before and / or during printing, especially when the polymer concentration in the formulation is high. In this case, the temperature can be heated to a maximum of 130 °C, a maximum of 120 °C or a maximum of 110 °C before and / or during printing.

[0082] Use The present invention also relates to the use of the polymer (P) of the present invention or the polymer formulation (F) of the present invention for the manufacture of 3D objects / articles.

[0083] All of the embodiments described above with respect to the polymer (P) and the polymer formulation (F) equally apply to the use for the manufacture of 3D objects / articles.

[0084] The present invention also relates to a 3D object or 3D article obtained at least in part from the manufacturing method of the present invention using the polymer (P) or polymer formulation (F) described herein.

[0085] In some embodiments, the 3D article of the present invention contains at least 1 ppm, such as at least 2 ppm, at least 5 ppm, or at least 10 ppm of residual acrylate or residual styrene, detected by photoacoustic FTIR measurement.

[0086] 3D objects or articles that can be obtained by such a manufacturing method can be used in various end uses. In particular, embedded devices, dental prostheses, brackets, and complex shaped parts in the aerospace industry and underhood parts in the automotive industry can be mentioned.

[0087] If the disclosure of any patent, patent application, and publication incorporated herein by reference conflicts with the description of this application to the extent that it may obscure the terms, this description shall prevail.

[0088] Here, the present invention will be described in more detail in connection with the following examples, but the purpose is merely illustrative and not intended to limit the scope of the present invention.

Example

[0089] Raw materials N,N-Dimethylacetamide (DMAc) (anhydrous, 99.8%), potassium carbonate (K2CO3) (anhydrous, >99.0%), Celite® 545 filter aid, and sodium bicarbonate (NaHCO3) were purchased from Sigma-Aldrich and used as received. Bisphenol A (BPA, >99%), trimethylolpropane triacrylate (TPM, containing 600 ppm of monomethyl ether hydroquinone as an inhibitor), acryloyl chloride (>97%, containing 400 ppm of phenothiazine as a stabilizer), and 4,4'-dichlorophenyl sulfone (DCPS) were purchased from Aldrich and used as received. Hydrochloric acid, chloroform (HPLC grade), toluene, sodium chloride, methanol, and tetrahydrofuran were purchased from Fisher Chemical and used as received. Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (>98%) was purchased from TCI and used as received. Chloroform-d (CDCl3) (99.8% atomic D) was purchased from Cambridge Isotope Labs and used as received. N-Methylpyrrolidone (NMP, BioSolv) and N,N-dimethylformamide (spectroscopic grade) were purchased from Spectrum and used as received. Triethylamine was purchased from Acros Organics, stirred overnight over calcium hydride (Sigma-Aldrich, 95%), and then distilled at 90 °C before use.

[0090] Example 1 - Synthesis of polysulfone polymer Three acrylate-terminated PSU polymers (comparative and inventive) were prepared by the two-step procedure according to Table 1. In Step 1, a phenol-terminated PSU polymer was prepared and characterized as shown in Scheme 1 below. In Step 2, the phenol-terminated PSU polymer was converted to the corresponding acrylate-terminated PSU polymer as shown in Scheme 2 below. Thereafter, the polymers were characterized by DSC and TGA as detailed below. The results are shown in Table 2 below.

[0091]

Table 1

[0092] Scheme 1 (Synthesis of PSU Polymer - Step 1)

Chemical formula

Chemical formula

[0093] Step 1: Preparation of phenol-terminated PSU polymer with Mn = 20,000 g / mol Nitrogen adapter, Dean-Stark trap with condenser, and Teflon TMIn a three-necked round-bottom flask equipped with a glass mechanical stirrer with paddles, BPA (52.74 g, 0.2310 mol), DCPS (64.89 g, 0.2260 mol), and potassium carbonate (38.32, 0.2772 mol) were dispersed in anhydrous N,N-dimethylacetamide (400 mL) and toluene (200 mL). The heterogeneous solution was purged with N2 for 20 minutes and then heated to 160 °C, at which point the reaction was refluxed for 5 hours. Subsequently, the resulting toluene / water azeotropic mixture was withdrawn, and the polymerization was further heated at 180 °C for 12 hours, cooled to room temperature, and the resulting solution was filtered through Celite® to remove the salts formed during the polymerization process. To protonate the phenol chain ends, the solution was then neutralized using 1 M HCl solution in THF, and the final 20,000 Mn PSU polymer was isolated by precipitation into 4 L of MeOH. The resulting white powder was vacuum dried at 200 °C for 18 hours. The molecular weight was determined using GPC.

[0094] Step 2: Preparation of acrylate-terminated PSU polymer with Mn = 20,000 g / mol The phenol-terminated PSU polymer obtained in Step 1 (60.00 g, 0.003 mol) was weighed into a one-neck round-bottom flask containing chloroform (200 mL) and a magnetic stir bar. Next, N2 was bubbled through the resulting solution for 20 minutes, triethylamine (5.735 mL, 0.041 mol) was added dropwise, and at that point the solution was cooled to 0 °C using an ice bath. Acryloyl chloride (2.078 mL, 0.026 mol) was added dropwise to the stirred solution. After the addition was complete, the reaction was stirred at 0 °C for 20 minutes and then heated to 23 °C and stirred for an additional 12 hours. The final product was washed with 2 M aqueous HCl, the layers were separated, the organic layer was stirred on basic alumina for 1 hour, followed by washing three times each with 1 M NaOH, sodium bicarbonate solution, and again with brine, dried over MgSO4 for 2 hours, and then precipitated into MeOH to obtain a white powder, which was then isolated by vacuum drying overnight at 50 °C. The terminal group conversion of the phenol chain ends was 1It was confirmed by observing the peak shift by ¹H NMR. This was done by placing the three peaks characteristic of acrylate at 6.00, 6.31, and 6.59 ppm. In this case, since the four benzyl protons used to track the previous end group shift and only two protons can be seen, instead of the four used previously, those two are used. Since these two protons are also partially located under the aromatic peak of the main chain, the integration becomes high and the integration value of the acrylate peak becomes pseudo-low.

[0095] Characterization of PSU Polymer GPC 20 mg of PSU was dissolved in 20 mL of chloroform to produce a 1 mg / mL sample. The solution was filtered through a 450 nm PTFE filter and placed in a quartz cuvette with a 1 cm optical path length. Dynamic light scattering (DLS) using a Malvern Zetasizer Nano ZS confirmed the dissolution of single chains in chloroform without aggregation. Then, the sample was eluted at a flow rate of 1 mL / min on an Acquity APC XT column of a Waters Acquity Advanced Polymer chromatography system. Mn from the refractive index was determined by comparison with a polystyrene standard at 35 °C.

[0096] DSC Differential scanning calorimetry using a TA instruments Q1000 revealed the glass transition temperature (T g ) in heating / cooling / heating cycles of 20 / 5 / 20 °C / min, respectively. T g was obtained from the inflection point of the second heating cycle.

[0097] TGA Thermogravimetric analysis was performed on a TA Instruments Q50 using N2 filled gas at a temperature gradient of 10 °C / min from 25 °C to 800 °C.

[0098]

Table 2

[0099] Example 2 - Formulations Prepared for Photopolymerization According to Table 3 below, multiple formulations were prepared. 0.36 g of PSU polymer was weighed into a 2-drum vial together with 0.84 g of NMP. The solution was mixed with a VWR mini vortexer until a homogeneous solution was obtained. 9 mg of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator) and TMP (polyfunctional acrylate) were added to the solution, the vial was covered with aluminum foil, and mixed overnight on a VWR standard analog shaker table. Samples were used within 24 hours.

[0100] [Table 3]

[0101] Photopolymerization Experiments: To determine the suitability of specific formulations for printability, a series of photopolymerization experiments were conducted. To enable the solution to be processed by tank photopolymerization, it is desirable that the elastic modulus exceeds 30,000 Pa and the G ’ / G ” crossover time is less than 2 seconds. The photopolymerization experiments were carried out at 25 °C with a TA Instruments DHR-2. These measurements were performed with a Smart Swap geometry equipped with an Omnicure S2000 high-pressure mercury light source with a filter of 320 - 500 nm, a 20 mm disposable aluminum parallel plate, and a 20 mm quartz parallel plate lower geometry with a 1000 μm gap TM geometry. The UV intensity was measured using a Silverline radiometer equipped with a 20 mm attachment. The measurement parameters were set at a sampling frequency of 1 Hz, a strain of 0.1%, and a UV light intensity of 250 mW / cm 2 . The samples were exposed to UV light for 15 seconds 30 seconds after the start of the experiment. Data were analyzed using TA Instruments TRIOS software, and the storage modulus (G ’ ), loss modulus (G ”) and determined the crossover time.

[0102] Table 4 shows how the molecular weight (Mn) of the polymer affects printability based on the photorheology when the formulation contains only the polymer and the photoinitiator. Polymers with a molecular weight of less than 12,000 g / mol exhibit a storage modulus that enables printing, while the polymer of Comparative Example 3 with a molecular weight of 20,000 g / mol has an elastic modulus that is too low to be printable.

[0103] [Table 4]

[0104] Table 5 shows that by adding trifunctional acrylate, it is possible to obtain an elastic modulus high enough to print parts based on the photorheology of the acrylate-functionalized polysulfone polymer with Mn = 20,000 g / mol. This also shows a significant improvement in the crossover time.

[0105] [Table 5]

[0106] Example 3 - Formulation used in vat photopolymerization The formulation of the present invention was prepared by dissolving Polymer P3 (27.552 g, 23.85 wt%), TMP (6.888 g, 5.96 wt%), and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide photoinitiator (0.706 g, 0.612 wt%) in NMP (80.36 g, 69.57%).

[0107] Parts were manufactured using a laser-based VP apparatus.

[0108] Laser-based VP apparatus: The 405nm UV laser and optical train were extracted from Formlabs 1+ and used to deliver UV irradiation to the resin surface. An aluminum tank was used to hold the resin during the printing process. A stainless-steel build stage with a glass build platform was used as the stage for part manufacturing. A stainless-steel rotary overcoating system was used to overcoat the resin on the build platform.

[0109] Printing method A 65ml formulation was transferred to an aluminum tank, and the build platform was placed at the focal plane of the projector. After a short dipping process, the build platform was placed at a depth equal to the thickness of one layer from the resin surface. Then, a rotary overcoating blade was used to smooth the resin surface from the post-meniscus-free state. The pattern corresponding to the layer to be manufactured was rasterized onto the resin surface at a predetermined number of passes, laser power, and scan speed. These steps were repeated until the part was completed.

[0110] PreForm 2.3.3 was used to slice the STL file into 120-micron layers. A customized Python program was used to control the apparatus and the printing process.

[0111] A hexagonal open lattice with a wall thickness of 750 microns for the columns, a side wall size of 2 mm, a height of 24 mm, a width of 17 mm, and a length of 28 mm was constructed in Netfabb and extruded to a height of 24 mm to form the reference geometry.

[0112] Printing results Printing parameters: · Layer thickness = 120 microns · Intensity = 20 mW · Scan speed = 1550 mm / s · Number of passes per layer = 1

[0113] Feature resolution: Hexagonal walls were visible along the height of the part. The average wall thickness was approximately 2 mm.

[0114] The addition of TMP increased the elastic modulus of the cured gel, and as a result, a self-supporting structure was formed faster than in the formulation without TMP.

Claims

1. A polymer blend (F), based on the total weight of said polymer blend (F): - 1 to 50% by weight, based on the total weight of F, of at least one poly(aryl ether sulfone) (PAES) polymer (P) of formula (M1) or (M2): 【Chemical 1】 (wherein, -R ２ is H or CH ３ and - X is a bond or n ranges from 1 to 20 (CH ２ ) ｎ is) contains at least one end group of, the number average molecular weight (Mn) of the polymer (P) is greater than 12,000 g / mol as measured by gel permeation chromatography (GPC) using methylene chloride as the mobile phase and polystyrene standards, the polymer (P), - at least one polyfunctional acrylate, - at least one solvent, - optionally at least one photoinitiator, - optionally at least one blocker and comprising, said polymer (P) is of formula (L): 【Chemical 2】 [wherein, - each R1 is independently, for each aromatic ring, selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium; - each i is independently, for each aromatic ring, zero or an integer from 1 to 4; - T is a bond, -CH2-; -O-; -SO2-; -S-; -C(O)-; -C(CH3)2-; -C(CF3)2-; -C(=CCl2)-; -C(CH3)(CH2CH2COOH)-; -N=N-; -RaC=CRb- (each Ra and Rb are independently of each other hydrogen, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C6-C18 aryl group, -(CH2)m- and -(CF2)m- where m is an integer from 1 to 6, a straight-chain or branched aliphatic divalent group of up to 6 carbon atoms, or a combination thereof) selected from the group consisting of] a PAES containing repeating units (RPAES) of, said polyfunctional acrylate is of the following formula (I): 【Chemical 4】 (wherein, - R3 is H or alkyl having 1 to 5 carbon atoms, - R4 is of formula (II): 【Chemical Formula 5】 according to, where n varies between 0 and 10) or The polyfunctional acrylate is selected from the group consisting of trimethylolpropane propoxytriacrylate, pentaerythritol triacrylate (PETA), glyceryl propoxytriacrylate (GPTA), di(trimethylolpropane) tetraacrylate, glycerol propoxylate triacrylate, pentaerythritol tetraacrylate, 1,3,5-triacryloylhexahydro-1,3,5-triazine, trimethylolpropane ethoxylate triacrylate, trimethylolpropane trimethacrylate, tris[2-(acryloyloxy)ethyl] isocyanurate, and mixtures thereof. Polymer formulation (F). **Claim 2** T is selected from the group consisting of a bond, -SO ２ -, and -C(CH ３ ) ２ -, the polymer blend (F) according to claim 1. **Claim 3** The polymer formulation (F) according to claim 1 or 2, wherein the PAES polymer contains at least 50 mol% (based on the total number of moles in the polymer) of repeating units of formula (L). **Claim 4** The PAES polymer is at least 50 mol% (based on the total number of moles in the polymer) of the following formula (wherein R １ and i are as described above): [Chemical Formula 3] The polymer formulation (F) according to any one of claims 1 to 3, comprising repeating units selected from the group consisting of... **Claim 5** The polymer formulation (F) according to any one of claims 1 to 4, comprising at least 0.05% by weight of polyfunctional acrylate based on the total weight of the polymer formulation (F). **Claim 6** The repeating unit (R PAES) is of formula (L''): and is a unit of The terminal group of the polymer (P) is of formula (M''): The polymer formulation (F) according to any one of claims 1 to 5, which follows **Claim 7** The polyfunctional acrylate is selected from the group consisting of trimethylolpropane propoxytriacrylate, pentaerythritol triacrylate (PETA), glyceryl propoxytriacrylate (GPTA), di(trimethylolpropane) tetraacrylate, glycerol propoxylate triacrylate, pentaerythritol tetraacrylate, 1,3,5-triacryloylhexahydro-1,3,5-triazine, trimethylolpropane ethoxylate triacrylate, trimethylolpropane trimethacrylate, tris[2-(acryloyloxy)ethyl] isocyanurate, and mixtures thereof. The polymer formulation (F) according to any one of claims 1 to 6. **Claim 8** The polyfunctional acrylate is of the following formula (III): 【Chemical Formula 6】 The polymer blend (F) according to any one of claims 1 to 6, which is obtained by

9. - The solvent is selected from the group consisting of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone (DMI), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), and sulfolane, - The photoinitiator is selected from the group consisting of 2,2-dimethoxy-2-phenylacetophenone (DMPA), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and / or - The blocker is selected from the group consisting of avobenzone and 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, The polymer blend (F) according to any one of claims 1 to 8.

10. The polymer blend (F) according to any one of claims 1 to 9, wherein the number average molecular weight (Mn) of the polymer (P) is at least 12,000 g / mol.

11. A method for manufacturing a 3D article with an additive manufacturing system, comprising: - Providing a polymer blend (F) according to any one of claims 1 to 10, - Printing a layer of the 3D article from the polymer blend (F), - Optionally, curing the 3D article at a temperature in the range of 50 to 450 °C. A method comprising the above steps.

12. The method according to claim 11, wherein the step of printing a layer of the 3D article from the polymer blend (F) comprises irradiating the polymer blend (F) with light.

13. Use of the polymer blend (F) according to any one of claims 1 to 10, alone or in combination with other components, for the manufacture of a 3D object by stereolithography (SLA), direct ink writing (DIW), digital light processing (DLP), or an inkjet process.

14. Use of the polymer blend (F) according to any one of claims 1 to 10, alone or in combination with other components, for coating an article.

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