Photosensitive compositions based on acrylates

• US 5,476,749 A
• Filed: 09/09/1994
• Issued: 12/19/1995
• Est. Priority Date: 03/27/1991
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Ciba-Geigy Corporation (Novartis Ag)
• Inventors: Schulthess, Adrian, Hunziker, Max, Wiesendanger, Rolf, Steinmann, Bettina
• Primary Examiner(s): Chapman, Mark A.
• Application Number:
  US08/303,563
• Time in Patent Office: 466 Days
• Field of Search: 430/280, 430/269, 430/15, 522/92
• US Class Current: 430/269
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• 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 7/027 Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds G03F7/075 takes precedence

Abstract

A liquid photosensitive composition comprising

(1) 40 to 80% by weight of a urethane (meth)acrylate having a functionality of 2 to 4 and a molecular weight (Mw) of 500 to 10,000,

(2) 5 to 40% by weight of a hydroxyl group containing aliphatic or cycloaliphatic di(meth)acrylate,

(3) 0 to 40% by weight of a mono(meth)acrylate or of a mono-N-vinyl compound having a Mw of not more than 500,

(4) 0.1 to 10% by weight of a photoinitiator,

(5) 0 to 30% by weight of an aliphatic or cycloaliphatic di(meth)acrylate which differs from (2), of an aliphatic tri(meth)acrylate or of an aromatic di- or tri(meth)acrylate, and

(6) 0 to 5% by weight of customary additives, such that the proportion of components (1) to (6) together is 100% by weight.

The composition is a photosensitive composition which can be polymerised by irradiation with actinic light and which is suitable for the production preferably of three-dimensional objects by the stereolithographic technique.

Claims

1. A liquid photosensitive composition consisting of

(1) 40 to 80% by weight of a urethane (meth)acrylate having a functionality of 2 to 4 and a molecular weight (Mw) of 500 to 10,000 which is the reaction product of a hydroxyl-terminated polyurethane with acrylic acid or methacrylic acid or the reaction product of an isocyanate-terminated prepolymer with hydroxyalkyl acrylates or methacrylates,

(2) 5 to 40% by weight of a hydroxyl group containing aliphatic or cycloaliphatic di(meth)acrylate which is the reaction product of an aliphatic or cycloaliphatic epoxy resin with (meth)acrylic acid,

(3) 0 to 40% by weight of a mono(meth)acrylate or of a mono-N-vinyl compound having a Mw of not more than 500,

(4) 0.1 to 10% by weight of a photoinitiator, and 0 to 5% by weight of further additives, such that the proportion of components (1) to (4) and any further additives together is 100% by weight and wherein components (1) and (2) are chemically different.

2. A composition according to claim 1, consisting of

(1) 40 to 80% by weight of a urethane (meth)acrylate having a functionality of 2 to 4 and a molecular weight (Mw) of 500 to 10,000,

(2) 5 to 40% by weight of a hydroxyl group containing aliphatic or cycloaliphatic di(meth)acrylate,

(3) 5 to 40% by weight of a mono(meth)acrylate or of a mono-N-vinyl compound having a Mw of not more than 500,

(4) 0.1 to 10% by weight of a photoinitiator, and 0 to 5% by weight of further additives.

3. A composition according to claim 1, wherein component (1) is an aliphatic urethane acrylate.

4. A composition according to claim 1, wherein the hydroxyl group containing diacrylate (2) is a reaction product of a diglycidyl ether of 1,4-butanediol and acrylic acid.

5. A composition according to claim 1, wherein component (2) is a hydroxyl group containing cycloaliphatic di(meth)acrylate.

6. A composition according to claim 5, wherein component (2) is a reaction product of the diglycidyl ester of hexahydrophthalic acid or bis(3,4-epoxycyclohexylmethyl)adipate and (meth)acrylic acid.

7. A composition according to claim 1, wherein component (3) is a mono-N-vinyl compound.

8. A composition according to claim 7, wherein component (3) is N-vinylpyrrolidone.

9. A composition according to claim 1, wherein the photoinitiator (4) is a 1-hydroxyphenyl ketone.

10. A composition according to claim 1, wherein the photoinitiator (4) is a 1-hydroxycyclohexyl phenyl ketone.

11. A process for polymerising a composition as claimed in claim 1 by irradiation with actinic light.

12. A three-dimensional object which is formed from a plurality of solidified layers which adhere to one another and which layers are obtained by the photopolymerization of a composition as claimed in claim 1.

13. A liquid photosensitive composition according to claim 1, wherein the proportion of component (1) is about 60 to 80% by weight of the entire composition.

14. A process for the production of three-dimensional objects from the liquid photosensitive composition of claim 1 by lithographic methods, wherein a layer of said liquid photosensitive composition is irradiated over the entire surface or in a predetermined pattern with a UV/VIS light source, such that within the irradiated areas a layer solidifies in a desired layer thickness, then a new layer of said composition is formed on the solidified layer, which is likewise irradiated over the entire surface or in a predetermined pattern, and such that three-dimensional objects are formed from a plurality of solidified layers which adhere to one an other by repeated coating and irradiation.

15. A process according to claim 14, wherein a laser beam, preferably a computer-controlled laser beam, is used as source of irradiation.