# US 12,594,717 B2 · Acriflavine fusing agents for three-dimensional printing

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- Number: US 12,594,717 B2
- Document ID: US12594717B2
- Status: Granted
- Kind: B2
- Application number: 18/572,714
- Filed: 2021-06-28
- Published: 2024-08-29
- Granted: 2026-04-07
- Earliest claimed: 2021-06-28
- Assignees: Peridot Print LLC
- Applicants: Peridot Print LLC
- Inventors: Emily Levin; Emre Hiro Discekici
- Web page: https://patentgrep.com/patent/US12594717B2

## 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)
- B29C 64/264: Arrangements for irradiation
- B29C 64/314: Preparation
- B33Y 10/00: Processes of additive manufacturing
- B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor
- B33Y 40/10: Pre-treatment
- B33Y 40/20: Post-treatment, e.g. curing, coating or polishing
- B33Y 70/00: Materials specially adapted for additive manufacturing
- B29K 2077/00: Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material
- B29K 2105/0032: {Pigments, colouring agents or opacifiyng agents}
- B29K 2105/251: {Particles, powder or granules (expandable particles B29K2105/046)}
- B29K 2995/002: Coloured
- B29K 2995/0094: Geometrical properties
- 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 fusing agent for three-dimensional printing can include an aqueous liquid vehicle and an acriflavine dye dissolved in the aqueous liquid vehicle. The aqueous liquid vehicle can include water, organic co-solvent, and surfactant.

## Claims

### Claim 1

A fusing agent for three-dimensional printing, the fusing agent consisting of:
an aqueous liquid vehicle consisting of water, an organic co-solvent, and a surfactant, wherein the water is present in an amount of from about 10 wt % to about 98 wt % with respect to a total weight of the fusing agent; and
an acriflavine dye dissolved in the aqueous liquid vehicle, wherein the acriflavine dye absorbs energy at a wavelength ranging from 350 nm to 500 nm.

### Claim 2 (depends on 1)

The fusing agent of claim 1, wherein the acriflavine dye is included in an amount of from about 0.5 wt % to about 18 wt % with respect to the total weight of the fusing agent.

### Claim 3 (depends on 2)

The fusing agent of claim 2, wherein the organic co-solvent is included in an amount of from about 1 wt % to about 40 wt % and the surfactant is included in an amount of from about 0.1 wt % to about 5 wt %, with respect to the total weight of the fusing agent.

### Claim 4 (depends on 1)

The fusing agent of claim 1, wherein the acriflavine dye is included in an amount of from about 8 wt % to about 18 wt % with respect to the total weight of the fusing agent.

### Claim 5 (depends on 1)

The fusing agent of claim 1, wherein the organic co-solvent is selected from the group consisting of 1,2 butanediol; 1,2-propanediol; 2,3-butanediol; 1,2-pentanediol; 2-methyl-2,4-pentanediol; 2-methyl-1,3-propanediol; tetrahydrofuran; ethylene glycol dimethyl ether; ethylene glycol; diethylene glycol;
triethylene glycol; propylene glycol; tripropylene glycol butyl ether; 2-pyrrolidone; 1-(2-hydroxyethyl)-2-pyrrolidone; and a combination thereof.

### Claim 6

A three-dimensional printing kit, comprising:
a polymer build material including from about 80 wt % to 100 wt % of polymeric particles; and
a fusing agent consisting of an aqueous liquid vehicle and an acriflavine dye dissolved in the aqueous liquid vehicle, wherein the aqueous liquid vehicle consists of water, an organic co-solvent, and a surfactant, and wherein the water is present in an amount ranging from about 10 wt % to about 98 wt % with respect to a total weight of the fusing agent,
wherein the acriflavine dye absorbs energy at a wavelength ranging from 350 nm to 500 nm.

### Claim 7 (depends on 6)

The three-dimensional printing kit of claim 6, wherein the polymeric particles comprise polyacetals, polyacrylates, polybutylene terephthalates, polycarbonates, polyesters, polyether ketones, polyethylene terephthalates, polyethylenes, polypropylenes, polystyrenes, polyurethanes, thermoplastic polyurethanes, polyamides, thermoplastic polyamides, a copolymer thereof, or a mixture thereof.

### Claim 8 (depends on 6)

The three-dimensional printing kit of claim 6, wherein the polymeric particles have a D50 particle size of from about 10 μm to about 150 μm.

### Claim 9 (depends on 6)

The three-dimensional printing kit of claim 6, wherein the organic co-solvent is present in an amount of from about 1 wt % to about 40 wt % with respect to the total weight of the fusing agent.

### Claim 10 (depends on 6)

The three-dimensional printing kit of claim 6, further comprising a second fluid agent, wherein the second fluid agent is a coloring agent including a liquid vehicle and a colorant, or a detailing agent including a detailing compound that reduces a temperature of the build material onto which the detailing agent is applied.

### Claim 11

A method for three-dimensional printing, the method comprising:
iteratively applying individual build material layers of a polymer build material including from about 80 wt % to 100 wt % of polymeric particles to a powder bed;
based on a three-dimensional object model, iteratively and selectively dispensing a fusing agent onto the individual build material layers, wherein the fusing agent consists of an aqueous liquid vehicle and an acriflavine dye dissolved in the aqueous liquid vehicle, wherein the aqueous liquid vehicle consists of water, an organic co-solvent, and a surfactant, wherein the water is present in an amount ranging from about 10 wt % to about 98 wt % with respect to a total weight of the fusing agent, and wherein the acriflavine dye absorbs energy at a wavelength ranging from 350 nm to 500 nm; and
iteratively exposing the powder bed to light energy having a peak wavelength of from about 365 nm to about 475 nm to selectively fuse the polymeric particles in contact with the acriflavine dye at the individual build material layers resulting in a fused three-dimensional object.

### Claim 12 (depends on 11)

The method of claim 11, wherein the light energy is provided by a light emitting diode having peak emission wavelength of about 435 nm or about 445 nm or about 450 nm or about 455 nm or about 460 nm.

### Claim 13 (depends on 11)

The method of claim 11, further comprising pre-heating the polymer build material to a pre-heat temperature that is from about 5° C. to about 85° C. below a melting point of the polymeric particles.

### Claim 14 (depends on 11)

The method of claim 11, wherein based on the three-dimensional object model, the method further comprises iteratively applying a second fluid agent to individual build material layers, wherein the second fluid agent is a coloring agent including a liquid vehicle and a colorant, or a detailing agent including a detailing compound that reduces a temperature of the build material onto which the detailing agent is applied.