Radiation curable composition for additive manufacturing processes

1. A radiation curable composition for additive-manufacturing processes, the composition comprising:

a (meth)acrylate component(s) not comprising a urethane moiety moiety as Component A1,

the (meth)acrylate component(s) comprising a polyether backbone to which (meth)acrylate moieties are attached and the (meth)acrylate component(s) characterized by a molecular weight Mw of at least 1,000 g/mol;

photo initiator as Component B;

a red dye, a yellow dye, an orange dye, or combination thereof as Component C, the red dye, the yellow dye, and the orange dye comprising a perylene moiety;

a blue dye as Component D,

the blue dye comprising a terephthalate moiety, and

the blue dye characterized by having a light absorption band in the range of 350 to 420 nm; and

optionally stabilizer as Component E.

2. The radiation curable composition according to claim 1 , the composition being characterized by the following features alone or in combination:

viscosity: less than 200 Pa*s at 23° C.;

pH value: 6 to 8;

light transmission: at least 40% for a path length of 1 mm using light having a wave length of 500 nm;

radiation curable with light having a wavelength in the range of 350 to 420 nm;

appearance: transparent;

color: red, yellow or orange.

3. The radiation curable composition according to claim 1 , the (meth)acrylate component(s) being characterized by the following features alone or in combination:

comprising at least 2 (meth)acrylate moieties;

molecular weight (Mw): from 1,000 to 20,000 g/mol;

viscosity: from 0.1 to 100 Pa*s at 23° C.

4. The radiation curable composition according to claim 1 , the red, orange or yellow dye being characterized by the following features alone or in combination:

solubility: soluble in triethylenglycoldi(meth)acrylate at 23° C.;

having a light absorption band in the range of 460 to 600 nm.

5. The radiation curable according to claim 1 , the blue dye being characterized by the following features alone or in combination:

solubility: soluble in triethylenglycoldi(meth)acrylate at 23° C.

6. The radiation curable composition according to claim 1 , the composition comprising in addition (meth)acrylate component(s) comprising an urethane moiety as Component A2, wherein Component A1 is present in a higher amount compared to Component A2.

7. A process of producing an elastomeric 3-dim article, the process comprising the step of processing the radiation curable composition described in claim 1 in an additive-manufacturing process comprising a radiation curing step using light with a wave length in the range from 350 to 420 nm.

8. The process of claim 7 , the elastomeric 3-dim article having the shape of an orthodontic or dental article, the dental article having the shape of a dental impression.

9. An elastomeric 3-dim article comprising the radiation curable composition as described in claim 1 in its cured state.

10. The elastomeric 3-dim article of claim 9 being characterized by the following features alone or in combination:

Tensile strength: from 0.5 to 50 MPa according to ISO/DIN 53504 (2015-8);

Elongation at break: from 10 to 1000% according to ISO/DIN 53504 (2015-8);

Shore hardness A: from 30 to 90 according to ISO/DIN 53505 (2000-8);

Light transmission: at least 50% for a path length of 1 mm at using light having a wave length in the range of 450 to 600 nm

Water contact angle: ≤100°;

Not sticky to surfaces of cured (meth)acrylates;

Color: red, orange or yellow.

11. A process of curing a radiation curable Composition II, the process comprising the steps of:

a) providing a radiation curable Composition I, the radiation curable Composition I being the radiation curable composition as described in claim 1 , b) processing the radiation curable Composition I in an additive-manufacturing process using radiation for curing the Composition I to obtain a transparent elastomeric 3-dim article having an outer side and an inner side, c) placing the radiation curable Composition II on the inner side of the transparent elastomeric 3-dim article, d) light curing the radiation curable Composition II from the outer side of the transparent elastomeric 3-dim article

the radiation curable Composition II being different from the radiation curable Composition I, the radiation curable Composition II comprising (meth)acrylate moieties, photo-initiator(s) and optionally filler(s).

12. The process of claim 11 , wherein the curing in step b) and step d) is done at different wave lengths.

13. The process of claim 11 ,

the radiation curing step b) being done at a wave length in the range from 350 to 420 nm,

the radiation curing step d) being done at a wave length in the range from 430 to 500 nm.

14. The process of claim 11 , the radiation curable Composition II being selected from a dental cement, a dental adhesive, or a dental composite material.

15. A kit of parts comprising:

a radiation curable Composition I, the radiation curable Composition I being the radiation curable composition as described in claim 1 , and

a radiation curable Composition II being different in its chemical composition from the radiation curable Composition I and being radiation curable within a wavelength in the range of 430 to 500 nm.