WATER-WASHABLE COMPOSITIONS FOR USE IN 3D PRINTING

Abstract

The present invention relates to radiation curable compositions, comprising (A1) at least one water-soluble reactive diluent (A1); (A2) at least one water-soluble reactive oligomer (A2); (B) at least one reactive component selected from the group consisting of a water insoluble reactive diluent (B1a), a slightly water-soluble reactive diluent (B1b) and a water insoluble, or slightly water-soluble reactive oligomer (B2); and (C) optionally a photoinitiator (C), wherein the amount of component (A1) and (A2) is greater than 20% by weight, especially 30% by weight based on the amount of components (A1), (A2), (B1a), (B1b) and (B2) and the amount of components (B1a), (B1b) and (B2) is greater than 10% by weight, especially 20% by weight based on the amount of components (A1), (A2), (B1a), (B1b) and (B2); radiation curable composition, comprising (A1′) at least one slightly water-soluble reactive diluent (B1b); (A2) at least one water-soluble reactive oligomer (A2); (B) at least one reactive component selected from the group consisting of a water insoluble reactive diluent (B1a) and a water insoluble, or slightly water-soluble reactive oligomer (B2); and (C) optionally a photoinitiator (C), wherein the amount of component (B1b) and (A2) is greater than 40% by weight, especially 50% by weight based on the amount of components (A2), (B1a), (B1b) and (B2) and the amount of components (B1a), (B1b) and (B2) is greater than 10% by weight, especially 20% by weight based on the amount of components (A2), (B1a), (B1b) and (B2). The radiation curable compositions can be cleaned by pure water with no assistance of any solvent or detergent. The printed three-dimensional products have clean, smooth, tack-free surface after washing with water and sufficient post-curing. The fully cured three-dimensional products are high-temperature resistant and have excellent mechanical performance above glass transition temperature, e.g. 200° C.

Claims

1.-17. (canceled)

18. A radiation curable composition, comprising (A1) at least one water-soluble reactive diluent (A1); (A2) at least one water-soluble reactive oligomer (A2); (B) at least one reactive component selected from the group consisting of a water insoluble reactive diluent (B1a), a slightly water-soluble reactive diluent (B1b) and a water insoluble, or slightly water-soluble reactive oligomer (B2); and (C) optionally a photoinitiator (C), wherein the amount of component (A1) and (A2) is greater than 20% by weight, especially 30% by weight based on the amount of components (A1), (A2), (B1a), (B1b) and (B2) and the amount of components (B1a), (B1b) and (B2) is greater than 10% by weight, especially 20% by weight based on the amount of components (A1), (A2), (B1a), (B1b) and (B2), or a radiation curable composition, comprising (A1′) at least one slightly water-soluble reactive diluent (B1b); (A2) at least one water-soluble reactive oligomer (A2); (B) at least one reactive component selected from the group consisting of a water insoluble reactive diluent (B1a) and a water insoluble, or slightly water-soluble reactive oligomer (B2); and (C) optionally a photoinitiator (C), wherein the amount of component (B1b) and (A2) is greater than 40% by weight, especially 50% by weight based on the amount of components (A2), (B1a), (B1b) and (B2) and the amount of component (B1a) and (B2) is greater than 10% by weight, especially 20% by weight based on the amount of components (A2), (B1a), (B1b) and (B2).

19. The radiation curable composition according to claim 18, wherein the water-soluble reactive diluent (A1) is selected from monofunctional (meth)acrylacrylamides, N-vinyloxazolidinones of formula ##STR00054## wherein R.sub.1, R.sup.2, R.sup.3 and R.sup.4 are independently of each other a hydrogen atom or an organic group having not more than 10 carbon atoms; polyethylene glycol (200) diacrylate (PEG200DA), polyethylene glycol (400) diacrylate, N-vinyl-caprolactam (NVC), N-vinyl-pyrrolidone (NVP) and N-vinyl-imidazole (VIM).

20. The radiation curable composition according to claim 18, wherein the water-soluble reactive diluent (A1) is selected from acryloylmorpholine, polyethylene glycol (200) diacrylate, N-vinyl-caprolactam (NVC), N-vinyloxazolidinone, N-vinyl-5-methyl oxazolidinone and mixtures thereof.

21. The radiation curable composition according to claim 18, wherein the water soluble oligomer (A2) is a water soluble urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, (meth)acrylic (meth)acrylate, or a mixture thereof, especially a water-dilutable (meth)acrylated polyurethane which is obtained from the reaction of at least one polyisocyanate compound (i), at least one polyester polyol (vi) comprising at least one polyethylene glycol segment and at least one pendant hydrophilic group, and at least one (meth)acrylated compound (iv) containing at least one reactive group capable to react with isocyanate groups.

22. The radiation curable composition according to claim 18, wherein the water insoluble oligomer (B2) is selected from polyester acrylates, polyether acrylates, epoxy acrylates, urethane acrylates and urethane methacrylates.

23. The radiation curable composition according to claim 18, wherein the water insoluble oligomer (B2) is obtained by reacting (b1) a hydroxyalkylacrylate, or hydroxyalkylmethacrylate, (b2) an aliphatic diisocyanate, an aliphatic polyisocyanate, a cycloaliphatic diisocyanate, a cycloaliphatic polyisocyanate, an aromatic diisocyanate, or an aromatic polyisocyanate, or mixtures thereof, (b3) a polyester polyol, which is derived from aliphatic dicarboxylic acids and aliphatic diols, and (b4) optionally a secondary polyol.

24. The radiation curable composition according to claim 22, wherein the water insoluble oligomer (B2) is obtained by reacting a polyalkylene glycol with a lactone of formula ##STR00055## at least one cycloaliphatic or asymmetric aliphatic diisocyanate and an hydroxyalkyl(meth)acrylate, or by reacting a lactone of formula (B2a) with at least one cycloaliphatic or asymmetric aliphatic diisocyanate and an hydroxyalkyl(meth)acrylate, wherein R.sup.113 is a divalent alkylene radical having 1 to 12 carbon atoms and which may optionally be substituted by C.sub.1 to C.sub.4 alkyl groups and/or interrupted by one or more oxygen atoms.

25. The radiation curable composition according to claim 22, wherein the water insoluble oligomer (B2) is obtained by reacting aliphatic, aromatic, or cyclic diisocyanates with hydroxyalkyl(meth)acrylate.

26. The radiation curable composition according to claim 23, wherein the water-insoluble reactive diluent (B1a) is selected from adamantyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, cyclodecyl (meth)acrylate, dicyclodecyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), trimethylolpropane ethoxy triacrylate (TMPEO3TA) and tricyclodecanedimethanol diacrylate.

27. The radiation curable composition according to claim 18, wherein the slightly water-soluble reactive diluent (B1b) is selected from cyclic trimethylolpropane formal acrylate, hydroxypropyl methacrylate, tripropylene glycol diacrylate, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate and triethylene glycol dimethacrylate (TEGDMA).

28. The radiation curable composition according to claim 18, which comprises TABLE-US-00025 Component Compound % by weight (A1) Acryloylmorpholine  9-59 (A2) Water dilutable aliphatic urethane acrylate 11-59 (B1b) Cyclic trimethylolpropane formal acrylate  9-59 (Q Photoinitiator 0.5-5   TABLE-US-00026 % by Component Compound weight (A1) Acryloylmorpholine   9-59 (A1) Polyethylene glycol (200) diacrylate 0.9-39 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B1a) Trimethylolpropane triacrylate 0.9-39 (C) Photoinitiator 0.5-5  TABLE-US-00027 % by Component Compound weight (A1) Acryloylmorpholine   9-59 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (B1a) Trimethylolpropane triacrylate 0.9-39 (B1b) Triethylene glycol dimethacrylate 0.9-39 (C) Photoinitiator 0.5-5  TABLE-US-00028 Component Compound % by weight (A1) Acryloylmorpholine   9-59 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (B1a) Trimethylolpropane triacrylate 0.9-39 (A1) Poly(ethylene glycol) diacrylate (average Mn 0.9-39 250; PEGDA250) (C) Photoinitiator 0.5-5  TABLE-US-00029 Component Compound % by weight (A1) N-vinyl-5-methyl oxazolidinone   9-59 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B2) 2-functional aliphatic urethane methacrylate 0.9-39 (B1b) Triethylene glycol dimethacrylate 0.9-29 (C) Photoinitiator 0.5-5  TABLE-US-00030 Component Compound % by weight (A1) N-vinyl-5-methyl oxazolidinone   9-59 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B2) Urethane methacrylate 0.9-29 (B1a) Trimethylolpropane triacrylate 0.9-29 (B1a) Ethoxylated (3) trimethylolpropane triacrylate 0.9-29 (C) Photoinitiator 0.5-5  TABLE-US-00031 Component Compound % by weight (B1b) 2- [[(Butylamino)carbonyl]oxy]ethyl acrylate 0.9-9  (A2) Water dilutable aliphatic urethane acrylate  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (B1a) Trimethylolpropane triacrylate 0.9-29 (B2) Urethane methacrylate 0.9-29 (C) Photoinitiator 0.5-5  TABLE-US-00032 Component Compound % by weight (A2) Water dilutable aliphatic urethane acrylate  21-59 (B1b) Cyclic trimethylolpropane formal acrylate  19-59 (B1a) Trimethylolpropane triacrylate 0.9-29 (B2) Urethane methacrylate 0.9-29 (B2) Urethane acrylate 0.9-29 (C) Photoinitiator 0.5-5  TABLE-US-00033 Component Compound % by weight (A1) N-Vinyl-caprolactam   9-59 (A2) Water dilutable aliphatic urethane acrylate  11-59 (B2) Urethane methacrylate 0.9-39 (B2) Urethane acrylate 0.9-59 (Q Photoinitiator 0.5-5 

29. The radiation curable composition according to claim 18, wherein the photoinitiator (C) is a compound of the formula ##STR00056## wherein R.sub.50 is unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl; or is cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted by one or more halogen, C.sub.1-C.sub.12alkyl, C.sub.1-C.sub.12alkoxy, C.sub.1-C.sub.12alkylthio or by NR.sub.53R.sub.54, or R.sub.50 is unsubstituted C.sub.1-C.sub.20alkyl or is C.sub.1-C.sub.20alkyl which is substituted by one or more halogen, C.sub.1-C.sub.12alkoxy, C.sub.1-C.sub.12alkylthio, NR.sub.53R.sub.54 or by —(CO)—O—C.sub.1-C.sub.24alkyl; R.sub.51 is unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl; or is cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted by one or more halogen, C.sub.1-C.sub.12alkyl, C.sub.1-C.sub.12alkoxy, C.sub.1-C.sub.12alkylthio or by NR.sub.53R.sub.54; or R.sub.51 is —(CO)R′.sub.52; or R.sup.51 is C.sub.1-C.sub.12alkyl which is unsubstituted or substituted by one or more halogen, C.sub.1-C.sub.12alkoxy, C.sub.1-C.sub.12alkylthio, or by NR.sub.53R.sub.54; R.sub.52 and R′.sub.52 independently of each other are unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl, or are cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted by one or more halogen, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4alkoxy; or R.sub.52 is a 5- or 6-membered heterocyclic ring comprising an S atom or N atom; R.sub.53 and R.sub.54 independently of one another are hydrogen, unsubstituted C.sub.1-C.sub.12alkyl or C.sub.1-C.sub.12alkyl substituted by one or more OH or SH wherein the alkyl chain optionally is interrupted by one to four oxygen atoms; or R.sub.53 and R.sub.54 independently of one another are C.sub.2-C.sub.12-alkenyl, cyclopentyl, cyclohexyl, benzyl or phenyl, or the photoinitiator (C) is a mixture of a compound of the formula (XII) and a compound of the formula ##STR00057## wherein R.sub.29 is hydrogen or C.sub.1-C.sub.18alkoxy; R.sub.30 is hydrogen, C.sub.1-C.sub.18alkyl, C.sub.1-C.sub.12hydroxyalkyl, C.sub.1-C.sub.18alkoxy, OCH.sub.2CH.sub.2—OR.sub.34, morpholino, S—C.sub.1-C.sub.18alkyl, a group —HC═CH.sub.2, —C(CH.sub.3)═CH.sub.2, ##STR00058## D, E and f are 1-3; c is 2-10; G.sub.1 and G.sub.2 independently of one another are end groups of the polymeric structure, preferably hydrogen or methyl; R.sup.34 is hydrogen, ##STR00059## R.sup.31 is hydroxy, C.sub.1-C.sub.16alkoxy, morpholino, dimethylamino or —O(CH.sub.2CH.sub.2O).sub.g—C.sub.1-C.sub.16alkyl; g is 1-20; R.sup.32 and R.sup.33 independently of one another are hydrogen, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.16alkoxy or —O(CH.sub.2CH.sub.2O).sub.g—C.sub.1-C.sub.16alkyl; or are unsubstituted phenyl or benzyl; or phenyl or benzyl substituted by C.sub.1-C.sub.12-alkyl; or R.sub.32 and R.sub.33 together with the carbon atom to which they are attached form a cyclohexyl ring; R.sub.35 is hydrogen, OR.sub.36 or NR.sub.37R.sub.38; R.sup.36 is hydrogen, C.sub.1-C.sub.12alkyl which optionally is interrupted by one or more non-consecutive O-atoms and which uninterrupted or interrupted C.sub.1-C.sub.12alkyl optionally is substituted by one or more OH, or R.sub.36 is ##STR00060## R.sub.37 and R.sub.38 independently of each other are hydrogen or C.sub.1-C.sub.12alkyl which is unsubstituted or is substituted by one or more OH; R.sub.39 is C.sub.1-C.sub.12alkylene which optionally is interrupted by one or more non-consecutive O, —(CO)—NH—C.sub.1-C.sub.12alkylene-NH—(CO)— or ##STR00061## with the proviso that R.sub.31, R.sub.32 and R.sub.33 not all together are C.sub.1-C.sub.16alkoxy or —O(CH.sub.2CH.sub.2O).sub.g—C.sub.1-C.sub.16alkyl, or the photoinitiator is a mixture of different compounds of the formula (XII), or the photoinitiator is a mixture of compounds of the formula (XII) and (XI).

30. Use of the radiation curable composition according to claim 18 in a photopolymerization 3D printing process, especially for producing dental molds.

31. Use according to claim 30, wherein the photopolymerization 3D printing process is vat photopolymerisation.

32. A method for producing a three-dimensional article, comprising a) providing the radiation curable composition according to claim 18, b) exposing the radiation curable composition to actinic radiation to form a cured crossection, c) repeating steps (a) and (b) to build up a green three-dimensional article, d) washing the three-dimensional article with pure water to remove the uncured, or partially cured components of the composition on the surfaces of the three-dimensional article; and e) post-curing the three-dimensional article.

33. The method according to claim 32, comprising a vat photopolymerization, wherein the radiation curable composition according to claim 18 in step b) is cured directly onto a translated or rotated substrate, and the irradiation is patterned via stereolithography, holography, LCD, or digital light projection (DLP).

34. A three-dimensional article produced by the method according to claim 32, or a three-dimensional article, which is a cured product of the radiation curable composition according to claim 18.

Description

EXAMPLES

Example 1

[0556] Photocurable Composition 1

TABLE-US-00015 Component Compound % by weight (A1) ACMO   9-59 (A2) UCECOAT ® 6569  11-59 (B1b) Cyclic trimethylolpropane formal   9-59 acrylate (C) Photoinitiator 0.5-5

Example 2

[0557] Photocurable Composition 2

TABLE-US-00016 Component Compound % by weight (A1) ACMO   9-59 (A1) Polyethylene glycol (200) diacrylate 0.9-39 (A2) UCECOAT ® 6569  11-59 (B1a) Trimethylolpropane triacrylate 0.9-39 (C) Photoinitiator 0.5-5

Example 3

[0558] Photocurable Composition 3

TABLE-US-00017 % by Component Compound weight (A1) ACMO   9-59 (A2) UCECOAT ® 6569  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (B1a) Trimethylolpropane triacrylate (TMPTA) 0.9-39 (B1b) Triethylene glycol dimethacrylate 0.9-39 (TEGDMA) (C) Photoinitiator 0.5-5

Example 4

[0559] Photocurable Composition 4

TABLE-US-00018 % by Component Compound weight (A1) ACMO   9-59 (A2) UCECOAT ® 6569  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (B1a) Trimethylolpropane triacrylate (TMPTA) 0.9-39 (A1) Poly(ethylene glycol) diacrylate (average 0.9-39 Mn 250; PEGDA250) (C) Photoinitiator 0.5-5

Example 5

[0560] Photocurable Composition 5

TABLE-US-00019 Component Compound % by weight (A1) N-vinyl-5-methyl oxazolidinone (NVMO)   9-59 (A2) UCECOAT ® 6569  11-59 (B2) GENOMER ® 4247 (urethane methacrylate) 0.9-29 (B1b) Triethylene glycol dimethacrylate 0.9-29 (TEGDMA) (C) Photoinitiator 0.5-5 

Example 6

[0561] Photocurable Composition 6

TABLE-US-00020 Component Compound % by weight (A1) N-vinyl-5-methyl oxazolidinone (NVMO)   9-59 (A2) UCECOAT ® 6569  11-59 (B2) GENOMER ® 4247 (urethane methacrylate) 0.9-29 (B1a) Trimethylolpropane triacrylate (TMPTA) 0.9-29 (B1a) Ethoxylated (3) trimethylolpropane triacrylate 0.9-29 (C) Photoinitiator 0.5-5 

Example 7

[0562] Photocurable Composition 7

TABLE-US-00021 Component Compound % by weight (B1b) 2-[[(Butylamino)carbonyl]oxy]ethyl acrylate 0.9-9  (Genomer ® 1122) (A2) UCECOAT ® 6569  11-59 (B1b) Cyclic trimethylolpropane formal acrylate   9-59 (LR 8887) (B1a) Trimethylolpropane triacrylate (TMPTA) 0.9-29 (B2) GENOMER ® 4247 (urethane methacrylate) 0.9-29 (C) Photoinitiator 0.5-5 

Example 8

[0563] Photocurable Composition 8

TABLE-US-00022 Component Compound % by weight (A2) UCECOAT® 6569  21-59 (B1b) Cyclic trimethylolpropane formal acrylate  19-59 (LR 8887) (B1a) Trimethylolpropane triacrylate (TMPTA) 0.9-29 (B2) GENOMER ® 4247 (urethane 0.9-29 methacrylate) (B2) Ebecryl ® 4587 (urethane acrylate) 0.9-29 (C) Photoinitiator 0.5-5 

Example 9

[0564] Photocurable Composition 9

TABLE-US-00023 % by Component Compound weight (A1) N-Vinyl-caprolactam (NVC)   9-59 (A2) UCECOAT ® 6569  11-59 (B2) GENOMER ® 4247 (urethane methacrylate) 0.9-39 (B2) Ebecryl ® 4587 (urethane acrylate) 0.9-59 (C) Photoinitiator 0.5-5 

[0565] Hot water having a temperature of less than 60° C. could improve the clearness after water washing, due to the solubility increase of slightly soluble monomers as well as the reduction of resin viscosity.

[0566] The cleaning liquid used is only pure water with no addition of organic solvent, alkali, acid, detergent, surfactant, absorbent or any extra chemicals to assist cleaning. The cleaning operation can be performed in various manners: apply heat, ultrasonic, different forms of different forms of water flow (static, vortex, shake, jet) etc.

[0567] After sufficient cleaning the surface of 3D printed object is dried by air completely before subjected to post-curing and further treatment(s).

[0568] Preparation of Inventive Photopolymers and Specimen for Mechanical Testing

[0569] The components of the photocurable compositions were mixed at a ratio as specified in Table 2 and 1.5 wt-% photoinitiator TPO by stirring at 70° C. for 30 minutes in a water bath using a 100 ml glass jar which was protected against daylight with aluminum foil. To start printing, the resulting clear mixtures were poured into the resin tank installed in MoonRay D75 DLP printer. The printing was conducted using the light source of 405 nm wavelength at the intensity of 3 mW/cm.sup.2. The thickness of the layer being cured at each time of irradiation was 50 μm. Stl files of standard specimens sliced for the desired layer were created and imported to the DLP printer. Specimens for tensile test were printed in x-direction and specimens for impact test were printed in y-direction. After finishing printing the specimens were removed from the picker, wiped off residual resins, water washed according to the above-described approaches for 60 seconds and air-blow dried for 30 seconds to obtain the cleaned specimens, which were post-cured in the NextDent™ LC 3D Printbox (equipped with UV-A and blue lamps) for 40 minutes.

[0570] After storage for 24 hours at 50% relative humidity the mechanical properties of the specimen were tested according to DIN EN ISO 527-1 (specimen type 5A) using Zwick Roell 10 kN Pro Line and DIN EN ISO 180 using a Zwick Roell HIT pendulum impact tester B5113.300 (5.5 J pendulum).

[0571] The viscosities of the photopolymers were determined at 50° C. at 100 s.sup.−1 shear rate using a cone/plate (60 mm diameter, 2° cone angle) rheometer (HR-1 Discovery, TA Instruments).

[0572] All UV doses were measured with a UV-Control 3CT, UV-technik meyer Gmbh.

TABLE-US-00024 Example Example 9 10 Example 11 Example 12 Component Wt-% Wt-% Wt-% Wt-% ACMO (A1) 39.4 32.9 — — UCECOAT ® 6569 (A2) 24.6 16.4 19.7  19.7 Cyclic trimethylolpropane formal 34.5 20.5 —  28.1 acrylate (B1b) Trimethylolpropane triacrylate 16.4 —  19.7 (TMPTA) (B1a) Poly(ethylene glycol) diacrylate — 12.3 — — (average Mn 250; PEGDA250) (A1) N-Vinyl-caprolactam (NVC) (A1) — — —  21.2 GENOMER ® 4247 (urethane — — 19.7   9.8 methacrylate) (B2) N-vinyl-5-methyl oxazolidinone 39.4 (NVMO) Triethylene glycol dimethacrylate 19.7 (TEGDMA) (B1b) Omnirad ® TPO (C) 1.50 1.50 1.5   1.50 Total 100.00 100.00 100  100.00 Viscosity [mPas] at 25° C./100 s.sup.−1 182 90 90  136.sup.1) E modulus [MPa] 1720 2660 2730 2430 Tensile strength at break [MPa].sup.2) 42 57 72  59 Elongation at break [%] 9.3 2.6 6.3   3.9 Tg [° C.] ( by DMA tan delta).sup.3) 73 129 .sup.1)Viscosity [mPas] at 30° C./100 s.sup.−1. .sup.2)Determined according to ISO 527-5A. 3)Dynamic mechanical analysis using the dissipation peak to determine the glass transition temperature of cured resin.

[0573] After the 3D product is formed by using 3D-printer and the compositions of Examples 9 to 12, any uncured composition is removed by washing with water. That means, the 3D printed object is just rinsed and/or soaked in pure water at room temperature for a short period of time (in particular less than 5 minutes to prevent water absorption) to dissolve any uncured, or partly cured composition.