Release film for producing green sheet and method of producing release film for producing green sheet

1. A release film for producing a green sheet, the release film comprising:

a base material having a first surface and a second surface; and

a release agent layer provided at a side of the first surface of the base material, wherein the release agent layer is formed by irradiating an ultraviolet ray to a coated layer and curing the coated layer, and the coated layer is formed by coating a release-agent-layer-forming material on the side of the first surface of the base material, wherein the release-agent-layer-forming material includes an ultraviolet curable compound (A) having three or more reactive functional groups selected from a (meth)acryloyl group, an alkenyl group and a maleimide group in one molecule thereof, a polyorganosiloxane (B) and an α-aminoalkylphenone-based photopolymerization initiator (C),

wherein an average thickness of the release agent layer is in a range of 0.3 to 2 μm,

wherein an arithmetic average roughness Ra 1 of an outer surface of the release agent layer is 8 nm or less and a maximum projection height Rp 1 of the outer surface of the release agent layer is 50 nm or less, and

wherein an arithmetic average roughness Ra 2 of the second surface of the base material is in a range of 5 to 40 nm and a maximum projection height Rp 2 of the second surface of the base material is in a range of 60 to 500 nm.

2. The release film of claim 1 , wherein a solid component content of the polyorganosiloxane (B) in the release-agent-layer-forming material is in a range of 0.5 to 5 mass %.

3. The release film of claim 1 , wherein the polyorganosiloxane (B) is a polyorganosiloxane having a straight or branched molecular chain and includes at least one reactive functional group selected from a group consisting of a (meth)acryloyl group, an alkenyl group and a maleimide group, and

wherein the reactive functional group is bonded, at one or both of terminals of the molecular chain and a side chain of the molecular chain, to silicon atoms of the molecular chain, either directly or through a bivalent linking group.

4. The release film of claim 1 , wherein the base material is formed into a laminated body having laminated layers, and at least one of the laminated layers is an antistatic layer.

5. The release film of claim 2 , wherein the polyorganosiloxane (B) is a polyorganosiloxane having a straight or branched molecular chain and includes at least one reactive functional group selected from a group consisting of a (meth)acryloyl group, an alkenyl group and a maleimide group, and

wherein the reactive functional group is bonded, at one or both of terminals of the molecular chain and a side chain of the molecular chain, to silicon atoms of the molecular chain, either directly or through a bivalent linking group.

6. The release film of claim 2 , wherein the base material is formed into a laminated body having laminated layers, and at least one of the laminated layers is an antistatic layer.

7. The release film of claim 3 , wherein the base material is formed into a laminated body having laminated layers, and at least one of the laminated layers is an antistatic layer.

8. A method of producing a release film for producing a green sheet, the method comprising:

preparing a base material having a first surface and a second surface;

preparing a release-agent-layer-forming material that includes an ultraviolet curable compound (A) having three or more reactive functional groups selected from a (meth)acryloyl group, an alkenyl group and a maleimide group in one molecule thereof, a polyorganosiloxane (B) and an α-aminoalkylphenone-based photopolymerization initiator (C); and

forming a release agent layer by irradiating an ultraviolet ray to a coated layer and curing the coated layer,

wherein the coated layer is formed by coating the release-agent-layer-forming material on a side of the first surface of the base material,

wherein an average thickness of the release agent layer is in a range of 0.3 to 2 μm,

wherein an arithmetic average roughness Ra 1 of an outer surface of the release agent layer is 8 nm or less and a maximum projection height Rp 1 of the outer surface of the release agent layer is 50 nm or less, and

wherein an arithmetic average roughness Ra 2 of the second surface of the base material is in a range of 5 to 40 nm and a maximum projection height Rp 2 of the second surface of the base material is in a range of 60 to 500 nm.

9. The method of claim 8 , wherein, in the forming the release agent layer, the ultraviolet ray is irradiated in an air atmosphere.

10. The method of claim 9 , wherein a solid component content of the polyorganosiloxane (B) in the release-agent-layer-forming material is in a range of 0.5 to 5 mass %.

11. The method of claim 8 , wherein a solid component content of the polyorganosiloxane (B) in the release-agent-layer-forming material is in a range of 0.5 to 5 mass %.

12. The method of claim 8 , wherein, in the preparing the release-agent-layer-forming material, the polyorganosiloxane (B) is a polyorganosiloxane having a straight or branched molecular chain and includes at least one reactive functional group selected from a group consisting of a (meth)acryloyl group, an alkenyl group and a maleimide group, and

wherein the reactive functional group is bonded, at one or both of terminals of the molecular chain and a side chain of the molecular chain, to silicon atoms of the molecular chain, either directly or through a bivalent linking group.

13. The method of claim 9 , wherein, in the preparing the release-agent-layer-forming material, the polyorganosiloxane (B) is a polyorganosiloxane having a straight or branched molecular chain and includes at least one reactive functional group selected from a group consisting of a (meth)acryloyl group, an alkenyl group and a maleimide group, and

wherein the reactive functional group is bonded, at one or both of terminals of the molecular chain and a side chain of the molecular chain, to silicon atoms of the molecular chain, either directly or through a bivalent linking group.

14. The method of claim 11 , wherein, in the preparing the release-agent-layer-forming material, the polyorganosiloxane (B) is a polyorganosiloxane having a straight or branched molecular chain and includes at least one reactive functional group selected from a group consisting of a (meth)acryloyl group, an alkenyl group and a maleimide group, and

wherein the reactive functional group is bonded, at one or both of terminals of the molecular chain and a side chain of the molecular chain, to silicon atoms of the molecular chain, either directly or through a bivalent linking group.

15. A method of producing a release film for producing a green sheet, the method comprising:

preparing a base material having a first surface and a second surface;

preparing a release-agent-layer-forming material that includes an ultraviolet curable compound (A) having three or more reactive functional groups selected from a (meth)acryloyl group, an alkenyl group and a maleimide group in one molecule thereof, a polyorganosiloxane (B) and an α-aminoalkylphenone-based photopolymerization initiator (C); and

forming a release agent layer by irradiating an ultraviolet ray to a coated layer and curing the coated layer,

wherein the coated layer is formed by coating the release-agent-layer-forming material on a side of the first surface of the base material, and

wherein an arithmetic average roughness Ra 1 of an outer surface of the release agent layer is different than an arithmetic average roughness Ra 2 of the second surface.

16. The method of claim 15 , wherein a maximum projection height Rp 1 of the outer surface of the release agent layer is different than a maximum projection height Rp 2 of the second surface of the base material.

17. The method of claim 16 , wherein the maximum projection height Rp 1 of the outer surface of the release agent layer is less than the maximum projection height Rp 2 of the second surface of the base material.

18. The method of claim 17 , wherein an average thickness of the release agent layer is in a range of 0.3 to 2 μm.

19. The method of claim 18 , wherein the arithmetic average roughness Ra 1 is not greater than 8 nm and the arithmetic average roughness Ra 2 is in a range of 5 to 40 nm.

20. The method of claim 19 , wherein the maximum projection height Rp 1 is not greater than 50 nm and the maximum projection height Rp 2 is in a range of 60 to 500 nm.