Photocurable compositions

• US 8,097,399 B2
• Filed: 03/21/2005
• Issued: 01/17/2012
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Patel, Ranjana, Zhao, Yong, Rhodes, Michael
• Primary Examiner(s): Hamilton, Cynthia
• Application Number:
  US10/593,746
• Publication Number:
  US 20070205528A1
• Time in Patent Office: 2,493 Days
• Field of Search: None
• US Class Current: 430/281.1
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29K 2033/00 Use of polymers of unsaturated acids or derivatives thereof as moulding material B29K2035/00 takes precedence
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021

Abstract

An optical moulding process is disclosed comprising the sequential steps of: (a)(y) forming a layer of a photocurable composition; and (bXz) irradiating selected areas of the composition in the layer with radiation from a radiation source, thereby curing the composition in said selected areas and repeating the steps a) and b) on top of an earlier cured layer to form a three dimensional structure, wherein the radiation source used in step b) is a non-coherent source of radiation and wherein the photocurable composition comprises at least two curable components: (i) 45%-95% (and preferably at least 50%, more preferably at least 60%, e.g. at least 70%) by weight of the total curable components in the composition is a first component that is photocurable and that is such that, when cured in the presence of a photocuring initiator by exposure to UV radiation having an energy of 30 mJ/cm², at least 90% of the component is cured within 50 milliseconds; and (ii) 5% to 55% (and preferably 10-40%, more preferably 15 to 30%, e.g. about 20%) by weight of the total curable components in the composition is a second component that results in the composition, on curing, shrinking, in a linear direction, by less than 3% and preferably that results in the composition having, after cure, a T_g of greater than 50° C., preferably at least 100° C. and more preferably at least 120° C.

Claims

1. An optical moulding composition comprising, in weight percent:

(a) at least two curable components;

(i) a first component in an amount of at least 80%, based on the total weight of the curable components in the composition, the first component comprising an acrylate and an acid amplified system comprising at least one cationically photocurable material, a cationic photocuring initiator, and an acid amplifier, the first component being photocurable and such that, when cured in the presence of a photocuring initiator by exposure to UV radiation having an energy of 30 mJ/cm², at least 90% by weight of the first component is cured within 50 milliseconds, and

(ii) a curable second component in an amount of at least 5% and at most 15% by weight of the total curable components in the composition, the second component being a compound having at least one terminal thiol group;

(b) 0.01 to 10%, by weight, of a radical photoinitiator,

(c) 0.001 to 5% by weight of a stabilizer, and

(d) 0 to 20% by weight of auxiliary materials.

2. A composition as claimed in claim 1, wherein at least 90% by weight of the first component is cured within 50 milliseconds, when the first component is cured in the presence of a photocuring initiator by exposure to UV radiation having an energy of 20 mJ/m².

3. A composition as claimed in claim 1, wherein the photocurable composition also contains 1 to 10% by weight of one or more flexibilisers or tougheners.

4. A composition as claimed in claim 1, wherein the first component includes a carbon-carbon double bond and the ratio of double bonds to thiol groups in the composition is 10:

1 to 2;

1.