Photosensitive compositions useful in three-dimensional part-building and having improved photospeed

• US 5,418,112 A
• Filed: 11/10/1993
• Issued: 05/23/1995
• Est. Priority Date: 11/10/1993
• Status: Expired due to Fees

• Current Assignee: W R Grace & Company - CONN (WR Grace & Company)
• Original Assignee: W R Grace & Company - CONN (WR Grace & Company)
• Inventors: Kumpfmiller, Ronald J., Mirle, Srinivas K.
• Primary Examiner(s): Chapman, Mark A.
• Application Number:
  US08/150,621
• Time in Patent Office: 559 Days
• Field of Search: 430/269, 430/284, 522/8, 522/10, 522/90, 522/100, 522/103
• US Class Current: 430/269
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: C08F 290/14 Polymers provided for in subclass C08G
• CPC Class Codes: C08G 18/48 Polyethers
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/029 Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur

Abstract

A method useful for stereolithography that yields enhanced photospeed, as well as a photocurable polymer composition well adapted for use with same, are disclosed.

A preferred combination includes 1,2-dimethoxy-2-phenyl acetophenone, benzophenone, and triphenyl phosphine combined with a polyurethane (meth)acrylate oligomer.

Claims

1. A method of manufacturing a three dimensional object from successive layers of a photocurable composition comprising the steps of:

(a) forming a layer of a photocurable polymer composition;

(b) exposing the layer to actinic radiation, thereby photocuring at least a portion of the layer;

(c) introducing a new layer of photocurable polymer composition into the exposed layer in (b);

(d) exposing the new layer in (c) to actinic radiation, thereby photocuring at least a portion of the layer in (c)

wherein the photocurable polymer composition is UV curable in air and comprises

A. a photoinitiator system which is

(1) at least one trivalent phosphorous compound;

(2) at least one photoinitiator; and

(3) a surface cure agent, and

B. a photopolymer which is an ethylenically unsaturated oligomer based on polyurethane, polyester or epoxy, wherein the photosensitive composition has a critical exposure energy E_c of less than about 1.5 mJ/cm² and

C. reactive diluents.

2. The method of claim 1, wherein (1) is an organic derivative of a phosphine.

3. The method of claim 1, wherein (1) is triphenyl phosphine.

4. The method of claim 1, wherein (2) is 2,2-dimethoxy-2-phenyl acetophenone.

5. The method of claim 1, wherein (3) is a substituted or unsubstituted benzophenone.

6. The method of claim 1, wherein oligomer B is a polyurethane (meth)acrylate.

7. The method of claim 1, wherein oligomer B is a reaction product of a polyether polyol, toluene diisocyanate and hydroxypropyl methacrylate.

8. The method of claim 1 wherein one of the reactive diluents C is ethoxylated trimethylol propane triacrylate.

9. The method of claim 1 wherein the photocurable polymer comprises, in weight percent:

(1) triphenylphosphine (0.1 to 5%);

(2) 2,2-dimethoxy-2-phenyl acetophenone (0.1 to 8%);

(3) benzophenone (0.1 to 5%).

10. The method of claim 1 wherein the photocurable polymer further comprises (4) stabilizers (0.1 to 3%).

11. The method of claim 10 wherein the stabilizers (4) are 2,6-di-tert-butyl-4-methyl phenol and 4-methoxy phenol.

12. The method of claim 11 wherein, in weight percent:

(1) is triphenylphosphine (0.2 to 3%);

(2) is 2,2-dimethoxy-2-phenyl acetophenone (1 to 4%);

(3) benzophenone (0.5 to 3%);

(4) is 2,6-di-tert-butyl-4-methyl phenol (0.1 to 1%) and 4-methoxyphenol (0.1 to 1%).