US 12,234,366 B2
Method for the 3D printing of two-component polyurethane compositions
Didier Lootens, Küsnacht (CH); Maxime Liard, Zürich (CH); Nicolas Bernardini, Eaubonne (FR); Fleur Chaignon-Lesetre, Serifontaine (FR); and Antonio Corsaro, Regensdorf (CH)
Assigned to SIKA TECHNOLOGY AG, Baar (CH)
Appl. No. 17/291,174
Filed by SIKA TECHNOLOGY AG, Baar (CH)
PCT Filed Dec. 18, 2019, PCT No. PCT/EP2019/085951
§ 371(c)(1), (2) Date May 4, 2021,
PCT Pub. No. WO2020/127484, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 18215746 (EP), filed on Dec. 21, 2018.
Prior Publication US 2021/0363366 A1, Nov. 25, 2021
Int. Cl. B29C 64/106 (2017.01); B33Y 70/00 (2020.01); C08G 18/22 (2006.01); C08G 18/32 (2006.01); C08G 18/38 (2006.01); C08G 18/48 (2006.01); C08G 18/66 (2006.01); C08G 18/76 (2006.01); C09D 11/102 (2014.01); B29K 75/00 (2006.01); B33Y 10/00 (2015.01)
CPC C09D 11/102 (2013.01) [B33Y 70/00 (2014.12); C08G 18/227 (2013.01); C08G 18/3206 (2013.01); C08G 18/3876 (2013.01); C08G 18/4829 (2013.01); C08G 18/6674 (2013.01); C08G 18/7671 (2013.01); B29C 64/106 (2017.08); B29K 2075/00 (2013.01); B33Y 10/00 (2014.12)] 16 Claims
 
1. A method of applying a two-component polyurethane composition by means of 3D printing, comprising the steps of
providing a pumpable first component A comprising
at least one polyol A1 having an OH functionality in a range from 1.5 to 4 and an average molecular weight (number average) Mn in a range from 250 to 15 000 g/mol, and
at least one diol A2 having two hydroxyl groups joined via a C2 to C9 carbon chain, and
at least one compound T having at least one thiol group;
feeding the first component A to a continuous mixer comprising
an inlet,
a mixing region having at least one static or dynamic mixing element connected to the inlet,
an outlet into which the mixing region opens,
wherein the first component A is conveyed through the at least one inlet into the mixing region;
feeding a pumpable second component B into the mixing region of the continuous mixer, where the second component B comprises at least one polyisocyanate I;
mixing the first component A with the second component B in the mixing region of the continuous mixer to give a mixed curable polyurethane composition;
conveying the mixed curable polyurethane composition to the outlet; and
applying the mixed curable polyurethane composition in a 3D printing layer-by-layer manner under computer control according to a defined mass or shape;
wherein one of the two components A and B additionally includes at least one metal catalyst K for reaction of hydroxyl groups and isocyanate groups that is able to form thio complexes, and
a molar ratio of all the thiol groups in the at least one compound T to all metal atoms in the at least one metal catalyst K is between 1:1 and 250:1.