Crosslinkable polycarbonates for material extrusion additive manufacturing processes

Patent metadata

Field	Value
Publication number	US-2017113407-A1
Application number	US-201515317361-A
Country	US
Kind code	A1
Filing date	Jun 16, 2015
Priority date	Jun 16, 2014
Publication date	Apr 27, 2017
Grant date	—

Abstract

Methods of making articles using additive manufacturing processes are disclosed. The article is built up from a multitude of layers. At least one layer includes a modeling material comprising a cross-linkable polycarbonate resin containing a photoactive group derived from a benzophenone. When exposed to an effective dosage of ultraviolet radiation, the modeling material crosslinks. This improves various properties of the final article.

First claim

1 . A method of making an article, comprising:
depositing one or more layers of extruded material in molten form in a preset pattern, wherein at least one layer is formed from a modeling material; and exposing the modeling material to an effective dosage of ultraviolet radiation to cause cross-linking in the article; wherein the modeling material is a polymeric composition that comprises a cross-linkable polycarbonate resin containing a photoactive group derived from a benzophenone.

2 . The method of claim 1 , wherein the modeling material is continuously exposed to the ultraviolet radiation during the deposition thereof in molten form.

3 . The method of claim 2 , wherein the deposition of the modeling material occurs in a chamber that is flooded with the ultraviolet radiation, such that the modeling material is continuously exposed to the ultraviolet radiation during deposition of each layer.

4 . The method of claim 2 , wherein a directed ultraviolet light source is used to expose a specific portion of the modeling material in molten form to ultraviolet radiation during the deposition thereof.

5 . The method of claim 1 , wherein a given layer of the modeling material is exposed to the ultraviolet radiation after the deposition of the given layer is complete.

6 . The method of claim 5 , wherein the modeling material of the layer is still in molten form during exposure to the ultraviolet radiation, or is solidified prior to exposure to the ultraviolet radiation.

7 . The method of claim 1 , wherein the layers of the modeling material are exposed to the ultraviolet radiation in a specified pattern.

8 . The method of claim 1 , wherein the modeling material is exposed to the ultraviolet radiation after the deposition of the one or more layers is complete.

9 . The method of claim 1 , wherein the benzophenone from which the photoactive group is derived is a monohydroxybenzophenone.

10 . The method of claim 9 , wherein the cross-linkable polycarbonate resin is formed from a reaction comprising:
the monohydroxybenzophenone; a diol chain extender; and a first linker moiety comprising a plurality of linking groups, wherein each linking group can react with the hydroxyl groups of the monohydroxybenzophenone and the diol chain extender.

11 . The method of claim 10 , wherein the cross-linkable polycarbonate resin contains from about 0.5 mol % to about 5 mol % of endcap groups derived from the monohydroxybenzophenone.

12 . The method of claim 1 , wherein the benzophenone from which the photoactive group is derived is a dihydroxybenzophenone.

13 . The method of claim 12 , wherein the cross-linkable polycarbonate resin is formed from a reaction comprising:
the dihydroxybenzophenone; a diol chain extender; a first linker moiety comprising a plurality of linking groups, wherein each linking group can react with the hydroxyl groups of the dihydroxybenzophenone and the diol chain extender; and an end-capping agent.

14 . The method of claim 13 , wherein the dihydroxybenzophenone is 4,4′-dihydroxybenzophenone; the diol chain extender is bisphenol-A; and the first linker moiety is phosgene.

15 . The method of claim 12 , wherein the cross-linkable polycarbonate resin contains from about 0.5 mol % to about 50 mol % of repeating units derived from the dihydroxybenzophenone.

16 . The method of claim 1 , wherein the modeling material is exposed to from about 0.025 J/cm 2 to about 21 J/cm 2 of UVA radiation, or wherein the modeling material is exposed to ultraviolet radiation having a wavelength between 280 nm and 380 nm.

17 . The method of claim 1 , wherein at least one layer is formed from an extruded material that is different from the modeling material, or wherein each layer is formed from the modeling material.

18 . The article formed by the method of claim 1 .

19 . The article of claim 18 , wherein the article has a storage modulus of about 400 MPa to about 1,600 MPa as measured by ASTM D5023-2007.

20 . A method of making an article, comprising:
depositing one or more layers of extruded material in molten form in a preset pattern, wherein at least one layer is formed from a modeling material; and exposing the modeling material to an effective dosage of ultraviolet radiation to cause cross-linking in the article; wherein the modeling material is a polymeric composition that comprises a cross-linkable polycarbonate resin containing a photoactive group.

Assignees

• Sabic Global Technologies Bv

Inventors

• Cox Keith E
• Hocker Thomas
• Morizur Jean-Francois
• Evans Thomas L
• Flores Amanda Marie
• Johnson Peter
• Visjager Jeroen
• Bihari Malvika

Classifications

• B29C2035/0827

  using UV radiation · CPC title

• B33Y10/00 Primary

  Processes of additive manufacturing · CPC title

• B29C64/118 Primary

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B29C67/0055 Primary

  Operations & Transport · mapped topic