# US 12,109,757 B2 · Three-dimensional printing with polyelectrolytes

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- Number: US 12,109,757 B2
- Document ID: US12109757B2
- Status: Granted
- Kind: B2
- Application number: 17/298,651
- Filed: 2019-08-06
- Published: 2022-05-19
- Granted: 2024-10-08
- Earliest claimed: 2019-08-06
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Hewlett-Packard Development Company, L.P.
- Inventors: Emre Hiro Discekici; Graciela Emma Negri Jimenez; Shannon Reuben Woodruff
- Web page: https://patentgrep.com/patent/US12109757B2

## CPC

- B29C 64/165: using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
- B29C 64/188: involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control (surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00)
- B33Y 10/00: Processes of additive manufacturing
- B33Y 70/00: Materials specially adapted for additive manufacturing
- B29K 2105/0032: {Pigments, colouring agents or opacifiyng agents}
- B29K 2995/002: Coloured
- B29K 2995/0092: hydrophilic
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS

## Abstract

A multi-fluid kit for three-dimensional printing can include a fusing agent comprising water and a radiation absorber, wherein the radiation absorber absorbs radiation energy and converts the radiation energy to heat. The multi-fluid kit can also include a detailing agent including an aqueous liquid vehicle and from about 1 wt % to about 12 wt % polyelectrolyte solubilized in the aqueous liquid vehicle at from about 90 wt % to 100 wt %. The polyelectrolyte can have a weight average molecular weight from about 1,000 Mw to about 12,000 Mw and can be water-absorbent at a water to polyelectrolyte weight ratio from about 2:1 to about 1,000:1.

## Claims

### Claim 1

A multi-fluid kit for three-dimensional printing, comprising:
a fusing agent comprising water and a radiation absorber, wherein the radiation absorber absorbs radiation energy and converts the radiation energy to heat; and
a detailing agent including:
an aqueous liquid vehicle; and
from about 1 wt % to about 12 wt % of a polyelectrolyte solubilized in the aqueous liquid vehicle at from about 90 wt % to 100 wt %, wherein the polyelectrolyte has a weight average molecular weight ranging from about 1,000 Mw to about 12,000 Mw and is water-absorbent at a water-to-polyelectrolyte weight ratio of from about 2:1 to about 1,000:1,
wherein the detailing agent is devoid of a radiation absorber.

### Claim 2 (depends on 1)

The multi-fluid kit of claim 1, wherein the polyelectrolyte is an anionic linear polyelectrolyte.

### Claim 3 (depends on 1)

The multi-fluid kit of claim 1, wherein the polyelectrolyte is fully dissociated in the aqueous liquid vehicle.

### Claim 4 (depends on 1)

The multi-fluid kit of claim 1, wherein the polyelectrolyte is selected from the group consisting of poly(acrylic acid sodium salt), poly(acrylic acid potassium salt), poly(acrylic acid lithium salt, poly(acrylic acid ammonium salt), and a combination thereof.

### Claim 5 (depends on 1)

The multi-fluid kit of claim 1, wherein the polyelectrolyte is present in the detailing agent in an amount ranging from about 4 wt % to about 8 wt %.

### Claim 6 (depends on 1)

The multi-fluid kit of claim 1, wherein the radiation absorber of the fusing agent is selected from the group consisting of a metal dithiolene complex, carbon black, a near-infrared absorbing dye, a near-infrared absorbing pigment, metal nanoparticles, a conjugated polymer, and a combination thereof.

### Claim 7 (depends on 1)

The multi-fluid kit of claim 1, wherein the fusing agent is colorless.

### Claim 8

A three-dimensional printing kit, comprising:
a powder bed material comprising from about 60 wt % to 100 wt % of polymer particles;
a fusing agent comprising water and a radiation absorber, wherein the radiation absorber absorbs radiation energy and converts the radiation energy to heat; and
a detailing agent including:
an aqueous liquid vehicle; and
from about 1 wt % to about 12 wt % of a polyelectrolyte solubilized in the aqueous liquid vehicle at from about 90 wt % to 100 wt %, wherein the polyelectrolyte has a weight average molecular weight ranging from about 1,000 Mw to about 12,000 Mw and is water-absorbent at a water to polyelectrolyte weight ratio of from about 2:1 to about 1,000:1,
wherein the detailing agent is devoid of a radiation absorber.

### Claim 9 (depends on 8)

The three-dimensional printing kit of claim 8, wherein the polymer particles are selected from the group consisting of polyamide 6 particles, polyamide 9 particles, polyamide 11 particles, polyamide 12 particles, polyamide 6/6 particles, polyamide 6/12 particles, polyethylene particles, thermoplastic polyurethane particles, thermoplastic polyamide particles, polypropylene, polyester particles, polycarbonate particles, polyether ketone particles, polyacrylate particles, polystyrene powder particles, wax particles, and a combination thereof.

### Claim 10 (depends on 8)

The three-dimensional printing kit of claim 8, wherein the polyelectrolyte is an anionic linear polyelectrolyte having a weight average molecular weight ranging from about 1,200 Mw to about 5,000 Mw.

### Claim 11 (depends on 8)

The three-dimensional printing kit of claim 8, wherein the radiation absorber of the fusing agent is selected from the group consisting of a metal dithiolene complex, carbon black, a near-infrared absorbing dye, a near-infrared absorbing pigment, metal nanoparticles, a conjugated polymer, and a combination thereof.

### Claim 12

A method of making a three-dimensional printed article, comprising:
iteratively applying individual powder bed material layers of polymer particles to a powder bed;
based on a three-dimensional object model, selectively applying a fusing agent onto the individual powder bed material layers at build areas where the three-dimensional printed article is being formed, wherein the fusing agent comprises water and a radiation absorber;
based on the three-dimensional object model, selectively applying a detailing agent onto individual powder bed material layers laterally at a border region between a first area where the powder bed material is contacted by the fusing agent and a second area where the powder bed material is not contacted by the fusing agent, wherein the detailing agent comprises an aqueous liquid vehicle and from about 1 wt % to about 12 wt % of a polyelectrolyte solubilized in the aqueous liquid vehicle at from about 90 wt % to 100 wt %, wherein the polyelectrolyte has a weight average molecular weight ranging from about 1,000 Mw to about 12,000 Mw, wherein the detailing agent is devoid of a radiation absorber; and
exposing the powder bed to energy to selectively fuse the polymer particles in contact with the radiation absorber to form a fused polymer matrix at individual powder bed material layers while retaining water associated with the polyelectrolyte at the border at a water-to-polyelectrolyte weight ratio of from about 2:1 to about 1,000:1.

### Claim 13 (depends on 12)

The method of claim 12, wherein the polyelectrolyte is selected from the group consisting of poly(acrylic acid sodium salt), poly(acrylic acid potassium salt), poly(acrylic acid lithium salt, poly(acrylic acid ammonium salt), and a combination thereof.

### Claim 14 (depends on 12)

The method of claim 12, wherein the selectively applying of the detailing agent to the build areas includes controlling a temperature of at least one layer of the three-dimensional printed article while being formed.