Radiation curable composition for water scavenging layer, and method of manufacturing the same

1. A photocurable resin composition comprising:

(A) 1-30% by weight of alkaline earth metal oxide particles selected from the group consisting of dehydrated CaO, dehydrated BaO and dehydrated MgO particles;

(B) 0.1-10% by weight of at least one photoinitiator, or any mixture thereof;

(C) 30-80% by weight of at least one acrylate or methacrylate component with a ClogP higher than 2, or any mixture thereof;

(D) 5-40% by weight of at least one monofunctional acrylate or methacrylate diluent component, or any mixture thereof;

(E) 5-30% by weight of at least one acrylate or methacrylate component with functionality equal or higher than 3, or any mixture thereof;

(F) 0.1-30% by weight of a polybutadiene acrylate or methacrylate, a silicone acrylate or methacrylate, or a two-mole ethoxylated bisphenol A di(meth)acrylate, or any mixture thereof;

based on the total weight of the composition;

wherein the photocurable resin exhibits a water content of less than 1000 ppm by weight;

wherein Mica is excluded from the group of (A) alkaline earth metal oxide particles; and

wherein the photocurable resin composition does not comprise any urethane (meth)acrylate, polyester (meth)acrylate, or polyethylene glycol (PEG) (meth)acrylate.

2. A photocurable resin composition according to claim 1 , wherein the alkaline earth metal oxide particles A exhibit an average particle diameter of 10 to 1000 nm.

3. A photocurable resin composition according to claim 1 , which exhibits a viscosity at 20° C. below 500 mPa·s,

and/or which exhibits a pot life at 60° C. longer than 29 days.

4. A photocurable resin composition according to claim 1 , wherein component (D) exhibits a ClogP higher than 2,

component (E) exhibits a ClogP higher than 1,

and/or component (F) exhibits a ClogP higher than 4.

5. A photocurable resin composition according to claim 1 , wherein component C is a 1,n-diol di(meth)acrylate of a diol of the formula HO—(CH 2 ) n —OH, whereby n is higher than 3.

6. A photocurable resin composition according to claim 1 , which, after curing, is transparent.

7. A photocurable resin composition according to claim 1 comprising at least:

(A) 4-20% by weight of dehydrated CaO, dehydrated BaO and/or dehydrated MgO particles (component A);

(B) 0.1-5% by weight of the photo initiator B;

(C) 40-70% by weight of component C;

(D) 10-30% by weight of the monofunctional (meth)acrylate diluent component D;

(E) 7-20% by weight of the (meth)acrylate component E with functionality equal or higher than 3; and

(F) 0.3-25% by weight of component F;

based on the total weight of the composition.

8. Method for preparing a photocurable resin composition according to claim 1 , comprising the steps of:

h) mixing and stirring together components C, D, E, and optionally F, in order to produce a mixture h, which is optionally dried, wherein component F is a polybutadiene acrylate or methacrylate, a silicone acrylate or methacrylate, or a two-mole ethoxylated bisphenol A di(meth)acrylate, or any mixture thereof;

i) incorporating dehydrated calcium, dehydrated barium and/or dehydrated magnesium oxide (component A) into the produced mixture h, so as to obtain a mixture i;

j) milling and/or grinding the produced mixture i, in order to downsize the average diameter of dehydrated calcium, dehydrated barium and/or dehydrated magnesium oxide particles, so as to produce a mixture j;

k) adding the photoinitiator B to the produced mixture j, so as to obtain a mixture k.

9. Method for preparing a photocurable resin composition according to claim 8 , wherein during the milling step j) the average particle diameter of the dehydrated CaO, dehydrated BaO and/or dehydrated MgO particles is reduced to the range of 10 to 1000 nm, and/or wherein the produced photocurable resin k exhibits a water content less than 1000 ppm by weight.

10. Method for manufacturing a multi layer barrier stack against water and oxygen penetration and diffusion, comprising the steps of:

m) depositing a first inorganic layer;

n) depositing onto said first inorganic layer, a first organic layer of the photocurable resin composition according to claim 1 ;

o) exposing said first organic layer to ultraviolet radiation, so as to solidify said first organic layer and to produce a transparent layer exhibiting water scavenging properties;

p) applying onto said first solidified organic layer, a second organic layer of a photocurable resin not containing metal oxide particles;

q) exposing said second organic layer to UV radiation, so as to solidify said second organic layer and to produce a transparent layer exhibiting planarization properties;

r) depositing onto said second solidified organic layer a second inorganic layer.

11. Method for manufacturing a multi layer barrier stack according to claim 10 , whereby the first organic layer exhibits a thickness between 10 and 100 micrometers, and/or whereby the second organic layer exhibits a thickness between 10 and 100 micrometers.

12. A method for manufacturing an opto-electric device, comprising the steps of:

providing an opto-electric element and/or layer,

providing an encapsulation comprising a multi layer barrier stack produced according to the method of claim 10 .

13. A multi layer barrier stack or opto-electric device, obtained by a method according to claim 10 .

14. A photocurable resin composition according to claim 1 , wherein component A comprises dehydrated CaO.

15. A photocurable resin composition according to claim 1 , wherein at least two (meth)acrylate functionalities are exhibited by component (F).

16. A photocurable resin composition according to claim 1 , wherein component (F) exhibits a ClogP higher than 2.

17. The photocurable resin composition according to claim 14 , wherein said dehydrated CaO have a calcium hydroxide content of less than 5% by weight and a calcium carbonate content of less than 1% by weight.