BINDER COMPOSITIONS FOR ADDITIVE MANUFACTURING COMPRISING LOW MOLECULAR WEIGHT POLYMERS INCLUDING ACRYLIC ACID REPEAT UNITS
Methods of additive manufacturing, binder compositions for additive manufacturing, and articles produced by and/or associated with methods of additive manufacturing are generally described.
1 - 41 . (canceled)
42 . A binder composition for additive manufacturing of metal objects by binder jetting, the binder composition comprising:
water;
a low molecular weight polymer including an acrylic acid repeat unit;
a cross-linking agent comprising a polyol, a multifunctional amine, and/or a multifunctional thiol; and
a pH modifier.
43 . The binder composition of claim 42 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 40 kDa.
44 . The binder composition of claim 42 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 6 kDa.
45 . The binder composition of claim 42 , wherein the binder composition has a viscosity of less than or equal to 20 cP at a printing temperature.
46 . The binder composition of claim 42 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 40 wt %.
47 . The binder composition of claim 42 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 25 wt %.
48 . The binder composition of claim 42 , wherein the pH of the binder composition is greater than or equal to 7.
49 . The binder composition of claim 42 , wherein the pH of the binder composition is greater than or equal to 4.
50 . The binder composition of claim 42 , wherein the pH modifier has a boiling point of less than or equal to 150° C.
51 . The binder composition of claim 42 , wherein the pH modifier is configured to be removed from the binder composition before the onset of a cross-linking reaction between the polymer including the acrylic acid repeat unit and the cross-linking agent.
52 . A three-dimensional composition formed by additive manufacturing, the composition comprising:
a metal powder; and
a binder composition, wherein the binder composition comprises:
water;
a low molecular weight polymer including an acrylic acid repeat unit;
a cross-linking agent comprising a polyol, a multifunctional amine, and/or a multifunctional thiol; and
a pH modifier.
53 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the metal powder is a steel powder.
54 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 40 kDa.
55 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 6 kDa.
56 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the binder composition has a viscosity of less than or equal to 20 cP at a printing temperature.
57 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 40 wt %.
58 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 25 wt %.
59 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the metal powder comprises a ferrous alloy having a chromium content of less than or equal to 2 wt %, and wherein the pH of the binder composition is greater than or equal to 7.
60 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the metal powder comprises a ferrous alloy having a chromium content of greater than or equal to 2 wt %, and wherein the pH of the binder composition is greater than or equal to 4.
61 . The three-dimensional composition formed by additive manufacturing of claim 52 , wherein the pH modifier has a boiling point of less than or equal to 150° C.
62 - 72 . (canceled)