Build material composition

Patent metadata

Field	Value
Publication number	US-12042859-B2
Application number	US-201816605123-A
Country	US
Kind code	B2
Filing date	Apr 12, 2018
Priority date	Mar 15, 2018
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

An example of a composition includes a host metal present in an amount of at least about 90 wt % based on a total weight of the composition. A flow additive is also present in an amount of less than about 10 wt % based on the total weight of the composition. The flow additive consists of an organic particle having crosslinked polymer chains, a glass transition temperature (T g ) of at least 90° C., and a primary particle diameter of 100 nm or less.

First claim

What is claimed is:

1. A build material composition for three-dimensional (3D) printing, the build material composition comprising:
host metal particles having an average particle size ranging from about 1 μm to less than 20 μm and present in an amount of from about 90 wt % to about 99.99 wt %, based on a total weight of the build material composition; and
a flow additive present in an amount of from about 0.01 wt % to about 10 wt % based on the total weight of the build material composition, wherein the flow additive consists of discrete organic particles each having crosslinked polymer chains, a glass transition temperature (T g ) of at least 90° C., and a primary particle diameter of 100 nm or less;
wherein the discrete organic particles of the flow additive do not adhere to the host metal particles.

2. The build material composition as defined in claim 1 wherein the build material composition is spreadable, having a Hausner Ratio less than 1.2.

3. The build material composition as defined in claim 1 wherein the crosslinked polymer chains are formed of:
a hydrophobic monomer having a T g of equal to or greater than 90° C. and water solubility lower than 0.1%; and
a multi-functional crosslinking monomer.

4. The build material composition as defined in claim 3 wherein each of the discrete organic particles includes:
from about 80 wt % to about 98 wt % of the hydrophobic monomer based on a total weight of the organic particle; and
from about 2 wt % to about 20 wt % of the multi-functional crosslinking monomer based on a total weight of the organic particle.

5. The build material composition as defined in claim 3 wherein:
the hydrophobic monomer is selected from the group consisting of isobornyl methacrylate, isobornyl acrylate, tert-butyl methacrylate, tert-butyl acrylamide, tert-butyl methacrylamide, N-phenylacrylamide, N-benzyl-methacrylamide, N-tert-octylacrylamide, cyclohexylmethacrylate, 4-tert-butylcyclohexyl methacrylate, benzhydryl methacrylate, methyl methacrylate, phenyl methacrylate, dihydrodicyclopentadienyl acrylate, 4-tert-butylstyrene, 2,6-dichlorostyrene, 2,5-dimethylstyrene, 4-methylstyrene, 3-methylstyrene, styrene, 2,4,6-trimethylstyrene, 4-acetoxystyrene, and combinations thereof; and
the multi-functional crosslinking monomer is selected from the group consisting of ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, N—N′-hexamethylenebisacrylamide, triethylene glycol dimethacrylate, zinc methacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, N—N′-ethylenebisacrylamide, N—N′-methylenebisacrylamide, 1,4-divinylbenzene, 1,3-divinylbenzene, and combinations thereof.

6. The build material composition as defined in claim 3 wherein the crosslinked polymer chains are further formed of a low T g monomer having a T g less than 90° C.

7. The build material composition as defined in claim 6 wherein each of the discrete organic particles includes:
from about 55 wt % to about 95 wt % of the hydrophobic monomer;
from about 5 wt % to about 40 wt % of the multi-functional crosslinking monomer; and
up to about 10 wt % of the low T g monomer.

8. The build material composition as defined in claim 6 wherein:
the hydrophobic monomer is selected from the group consisting of isobornyl methacrylate, isobornyl acrylate, tert-butyl methacrylate, tert-butyl acrylamide, tert-butyl methacrylamide, N-phenylacrylamide, N-benzyl-methacrylamide, N-tert-octylacrylamide, cyclohexylmethacrylate, 4-tert-butylcyclohexyl methacrylate, benzhydryl methacrylate, methyl methacrylate, phenyl methacrylate, dihydrodicyclopentadienyl acrylate, 4-tert-butylstyrene, 2,6-dichlorostyrene, 2,5-dimethylstyrene, 4-methylstyrene, 3-methylstyrene, styrene, 2,4,6-trimethylstyrene, 4-acetoxystyrene, and combinations thereof;
the multi-functional crosslinking monomer is selected from the group consisting of ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, N—N′-hexamethylenebisacrylamide, triethylene glycol dimethacrylate, zinc methacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, N—N′-ethylenebisacrylamide, N—N′-methylenebisacrylamide, 1,4-divinylbenzene, 1,3-divinylbenzene, and combinations thereof; and
the low T g monomer is selected from the group consisting of n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, ethyl acrylate, n-propyl acrylate, benzyl acrylate, and combinations thereof.

9. The build material composition as defined in claim 3 wherein the crosslinked polymer chains are further formed of an acidic monomer selected from the group consisting of 2-acrylamido-2-methy-1-propanesulfonic acid, methacrylic acid, and combinations thereof.

10. The build material composition as defined in claim 1 wherein each of the discrete organic particles has a degree of crosslinking of at least 2%.

11. The build material composition as defined in claim 1 wherein the flow additive is pyrolyzable at a pyrolysis temperature that is less than a sintering temperature of the host metal particles, wherein the sintering temperature ranges from about 500° C. to about 1800° C.

12. The build material composition as defined in claim 1 wherein the discrete organic particles of the flow additive are hydrophobic.

13. A three-dimensional (3D) printing kit, comprising:
a build material composition, including:
host metal particles having an average particle size ranging from about 1 μm to less than 20 μm and present in an amount of from about 90 wt % to about 99.99 wt %, based on a total weight of the build material composition; and
a flow additive present in an amount of from about 0.01 wt % to about 10 wt % based on the total weight of the build material composition, wherein the flow additive consists of discrete organic particles each having crosslinked polymer chains, a glass transition temperature (T g ) of at least 90° C., and a primary particle diameter of 100 nm or less,
wherein the discrete organic particles of the flow additive do not adhere to the host metal particles; and

a binder agent to be applied to at least a portion of a layer of the build material composition via an inkjet printhead to pattern a cross-section of an intermediate part.

14. The 3D printing kit as defined in claim 13 wherein the build material composition is spreadable, having a Hausner Ratio less than 1.25.

15. A method for making a three-dimensional printing build material composition, comprising:
co-polymerizing a hydrophobic monomer having a glass transition temperature (T g ) of equal to or greater than 90° C. and water solubility lower than 0.1% and a multi-functional crosslinking monomer to form discrete organic particles each having crosslinked polymer chains, a glass transition temperature (T g ) of at least 90° C., and a primary particle diameter of 100 nm or less in a dispersion;
separating the discrete organic particles from the dispersion to form a flow additive consisting of the discrete organic particles; and
combining host metal particles and the flow additive to form a build material mixture, the host metal particles having an average particle size ranging from about 1 μm to less than 20 lam and being present in an amount of from about 90 wt % to about 99.99 w

Assignees

• Hewlett Packard Development Co

Inventors

• Chen Tienteh
• Kasperchik Vladek

Classifications

• B22F10/10

  Formation of a green body · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F10/73 Primary

  of powder · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title