RADIATION CURABLE AND PRINTABLE POLYSILOXANE COMPOSITION

Abstract

The present invention relates to radiation or dual radiation/moisture curable compositions based on (meth)acrylate- and silane-terminated polyorganosiloxanes that can be used as 3D printing materials and provide isotropic and elastomeric properties. The invention further relates to the use thereof as 3D printing materials and printing methods using said compositions.

Claims

1. Reactive curable printable composition, comprising a) at least one first polymer A comprising at least one terminal group of the general formula (I)
-A.sup.1-C(═O)—CR.sup.1═CH.sub.2   (I), wherein A.sup.1 is a divalent bonding group containing at least one heteroatom; and R.sup.1 is selected from H and C.sub.1-C.sub.4 alkyl, preferably H and methyl; and, optionally, at least one terminal group of the general formula (II)
-A.sup.2—SiXYZ   (II), wherein X, Y, Z are, independently of one another, selected from the group consisting of a hydroxyl group and C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy, and C.sub.1 to C.sub.8 acyloxy groups, wherein X, Y, Z are substituents directly bound with the Si atom or the two of the substituents X, Y, Z form a ring together with the Si atom to which they are bound, and at least one of the substituents X, Y, Z is selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkoxy and C.sub.1 to C.sub.8 acyloxy groups; and A.sup.2 is a divalent bonding group containing at least one heteroatom; wherein the polymer backbone of the at least one polymer A is a polyorganosiloxane; and, optionally, b) at least one second polymer B comprising at least one terminal group of the general formula (II)
-A.sup.2-SiXYZ   (II), wherein X, Y, Z are, independently of one another, selected from the group consisting of a hydroxyl group and C.sub.1 to C.sub.8 alkyl, C.sub.1 to C.sub.8 alkoxy, and C.sub.1 to C.sub.8 acyloxy groups, wherein X, Y, Z are substituents directly bound with the Si atom or the two of the substituents X, Y, Z form a ring together with the Si atom to which they are bound, and at least one of the substituents X, Y, Z is selected from the group consisting of a hydroxyl group, C.sub.1 to C.sub.8 alkoxy and C.sub.1 to C.sub.8 acyloxy groups; A.sup.2 is a divalent bonding group containing at least one heteroatom; and wherein the polymer backbone of the at least one polymer B is optionally a polyorganosiloxane; and wherein the composition is in form of a paste and has a yield stress of greater than 25, preferably 50 or more, more preferably 75 or more, wherein the yield stress is calculated using the formula: ${\tau }^{\frac{1}{2}}=k_{\mathrm{oc}}^{\frac{1}{2}}+k_c^{\frac{1}{2}}{\gamma }^{\frac{1}{2}},$ wherein τ is the shear stress, k.sub.oc is the Casson yield stress, k.sub.c is the Casson plastic viscosity and γ is the shear rate.

2. The reactive curable printable composition of claim 1, wherein said first polymer A comprises at least one terminal group of formula (II) and/or said composition comprises a second polymer B.

3. The reactive curable printable composition of claim 1, wherein the at least one polymer A (i) comprises at least two terminal groups of the general formula (I) or comprises at least one terminal group of formula (I) and at least one terminal group of formula (II); and/or (ii) comprises 1 to 100 mol-% of terminal groups of formula (I) and 99 to 0 mol-% of terminal groups of formula (II); and/or (iii) comprises (i) two or three terminal groups of formula (I) or (ii) one terminal group of formula (I) and one or two terminal group of formula (II), or (iii) two terminal groups of formula (I) and one terminal group of formula (II); and/or (iv) is a linear polymer.

4. The reactive curable printable composition of claim 1, wherein the at least one polymer A and/or the at least one polymer B have a polyorganosiloxane backbone.

5. The reactive curable printable composition of claim 1, wherein A.sup.1 and/or A.sup.2 comprises a substituted or unsubstituted ether, amide, carbamate, urethane, urea, imino, siloxane, carboxylate, carbamoyl, amidino, carbonate, sulfonate or sulfinate group, preferably a urea and/or urethane group.

6. The reactive curable printable composition of claim 1, wherein in formula (I) A.sup.1 is a group of formula (III)
—R.sup.11-A.sup.11-(R.sup.12-A.sup.12).sub.n-R.sup.13—  (III) wherein R.sup.11, R.sup.12, and R.sup.13 are independently a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms, preferably a substituted or unsubstituted (cyclo)alkylene or arylene residue with 1 to 14 carbon atoms; A.sup.11 and A.sup.12 are each independently a divalent group selected from —O—C(═O)—NH—, —NH—C(═O)O—, —NH—C(═O)—NH—, —NR″—C(═O)—NH—, —NH—C(═O)—NR″—, —NH—C(═O)—, —C(═O)—NH—, —C(═O)—O—, —O—C(═O)—, —O—C(═O)—O—, —S—C(═O)—NH—, —NH—C(═O)—S—, —C(═O)—S—, —S—C(═O)—, —S—C(═O)—S—, —C(═O)—, —S—, —O—, and —NR″—, wherein R″ can be hydrogen or a hydrocarbon moiety with 1 to 12 carbon atoms; and n is 0 or 1.

7. The reactive curable printable composition of claim 6, wherein R.sup.11 is a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms; A.sup.11 is a divalent group selected from —O—C(═O)—NH—, —NH—C(═O)—NH—, and —NR″—C(═O)—NH—, preferably —O—C(═O)—NH—; R.sup.13 is a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms, preferably a substituted or unsubstituted alkylene residue with 1 to 8 carbon atoms; n is 0 or 1, provided that if n is 1, R.sup.12 is a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms, preferably a substituted or unsubstituted (cyclo)alkylene residue or arylene residue with 1 to 14 carbon atoms; and A.sup.12 is a divalent group selected from —NH—C(═O)O—, —NH—C(═O)—NH—, and —NH—C(═O)—NR″—.

8. The reactive curable printable composition of claim 1, wherein A.sup.2 is a group of formula (IV)
—R.sup.21-A.sup.21-(R.sup.22-A.sup.22).sub.m-R.sup.23—  (IV) wherein R.sup.21, R.sup.22, and R.sup.23 are independently a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms; A.sup.21 and A.sup.22 are each independently a divalent group selected from siloxane, —O—C(═O)—NH—, —NH—C(═O)O—, —NH—C(═O)—NH—, —NR″—C(═O)—NH—, —NH—C(═O)—NR″—, —NH—C(═O)—, —C(═O)—NH—, —C(═O)—O—, —O—C(═O)—, —O—C(═O)—O—, —S—C(═O)—NH—, —NH—C(═O)—S—, —C(═O)—S—, —S—C(═O)—, —S—C(═O)—S—, —C(═O)—, —S—, —O—, and —NR″—, wherein R″ can be hydrogen or a hydrocarbon moiety with 1 to 12 carbon atoms; and m is 0 or 1.

9. The reactive curable printable composition of claim 8, wherein R.sup.21 is a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms; R.sup.23 is a bond or a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms; n is 0 or 1, provided that if n is 0, A.sup.21 is a divalent group selected from —O—, —O—C(═O)—NH—, —NH—C(═O)—NH—, and —NR″—C(═O)—NH—; and provided that if n is 1, A.sup.21 is a divalent group selected from —O—, —O—C(═O)—NH—, —NH—C(═O)—NH—, and —NR″—C(═O)—NH—; R.sup.22 is a divalent substituted or unsubstituted hydrocarbon residue with 1 to 20 carbon atoms; and A.sup.22 is a divalent group selected from —NH—C(═O)O—, —NH—C(═O)—NH—, and —NH—C(═O)—NR″—.

10. The reactive curable printable composition of claim 1, wherein (1) in formula (II), X, Y, and Z are, independently of one another, selected from a hydroxyl, a methyl, an ethyl, a methoxy, or an ethoxy group, wherein at least one of the substituents is a hydroxyl group, or a methoxy or an ethoxy group; and/or (2) R.sup.11, R.sup.21 and R.sup.23 in the general formulae (III) and/or (IV) are selected from a bond, methylene, ethylene, or n-propylene group.

11. The reactive curable printable composition of claim 1, wherein the composition further comprises c) at least one photoinitiator; d) at least one filler; and/or e) at least one catalyst.

12. The reactive curable printable composition according to claim 1, wherein the composition comprises, relative to the total weight of the composition, (1) 0.01 to 90 wt.-% of the at least one polymer A and, optionally, the at least one polymer B; (2) 0.01 to 5 wt.-% of the at least one photoinitiator; (3) 0.01 to 60 wt.-% of the at least one filler; and/or (4) 0.01 to 5.0 wt.-% of the at least one condensation catalyst.

13. Method for manufacturing a three-dimensional part by extruded filament fabrication, the method comprising: (a) printing a reactive curable printable composition according to any one of the preceding claims in a layer-by-layer manner to form the three-dimensional part; (b) curing the printed layers of the reactive curable printable composition to obtain the three-dimensional part.

14. The method of claim 13, wherein the curing step (b) comprises a first curing step comprising exposure of the printed layers to radiation, and a second curing step comprising exposing the printed layers to moisture.

Description

EXAMPLES

Example 1: (Meth)Acrylate-Terminated Polymers

[0196]

TABLE-US-00003 TABLE 1 (all amounts in wt.-%) Component/Formulation Polymer 1 Polymer 2 Polymer 3 PDMS Carbinol 3.000 (di-funct) 70.77 PDMS Carbinol 12.000 (di-funct) 88.57 PDMS Carbinol 25.000 93.27 IPDI 18.38 7.17 4.17 Hydroxy Ethyl Methacrylate 10.78 4.17 2.47 DOTL 0.07 0.09 0.09 Total 100 100 100 DOTL: Dioctyl tin dilaurate

[0197] In a first step, the polymer (Polydimethylsiloxane; PDMS), the isocyanate (IPDI) and the catalyst (DOTL) were mixed for 2.5 hours at 80° C. under nitrogen at 400 U/minute. The molar ratio of OH groups to NCO groups was 1:1. After the reaction, the reaction mixtures were allowed to cool to 25° C. and then the acrylate was added (in an amount that corresponds to a molar ratio of OH (polyol):NCO:OH (acrylate) of 1:1:1). Mixing was carried out for 3 hours at 25° C. The obtained Polymers 1 to 3 were cloudy liquids. The properties of these polymers are shown in Table 2.

TABLE-US-00004 TABLE 2 Polymer 1 Polymer 2 Polymer 3 Molecular weight (Mw) - PD  5355 - 1.39 27912 - 1.64 32394 - 1.61 (Polydispersity) (GPC)  373 - 1.04  313 - 1.05  363 - 1-04 Viscosity mPa.s 31390  5450  8690 NMR results No PDMS CH—OH 9% PDMS CH—OH No PDMS CH—OH No NCO high NCO high NCO trace HEMA trace HEMA trace HEMA Side reaction Side reaction leading Side reaction leading leading to CH—O—Si to CH—O—Si bond to CH—O—Si bond bond 24% 44% 34% Stability study viscosity 14 d RT 30840 Viscosity 28 d RT 28740 Viscosity 42 d RT 24250 Viscosity 14 d 50° C. 29620 Viscosity 28 d 50° C. 27290 Viscosity 42 d 50° C. 28720

[0198] Example 2: 3D Printing Formulation Based on (Meth)Acrylate-Terminated PDMS Polymers

TABLE-US-00005 TABLE 3 (all amounts in wt.-%) Component/Formulation Formulation 1 Formulation 2 Polymer 1 of Ex. 1 61.3 88.3 Viscoexcel 30 SG (fatty acid 37.2 — modified chalk filler) Silica HDK H-18 (silica filler) — 9.5 Omnirad TPO-L (photoinitiator) 1.0 1.4 Tinuvin 328 (light stabilizer) 0.5 0.7 Total 100 100 Color white translucent Tensile Strength (N/mm.sup.2) 7.4 8.9 Viscosity @ 1/s shear rate (25° C.; 568000 860000 mPa.s) Printability Yes Yes Yield stress >25 >25