Molding material, sheet molding compound, and fiber-reinforced composite material obtained using same
The present invention relates to a molding material, having: (A): a fiber substrate made of carbon fibers 5 mm or longer; (B): at least either an epoxy (meth)acrylate resin or an unsaturated polyester resin; (C): (C-1) inorganic fibrous filler with a cross-sectional area of at least 0.8 μm 2 , or (C-2) inorganic flaky filler with a cross-sectional area of at least 0.05 μm 2 , both of which have an aspect ratio of 2.0 or higher and a length of less than 3 mm; and (D): a polyisocyanate compound.
1. A molding material, comprising:
(A): a fiber substrate made of carbon fibers having a length of 5 mm or longer;
(B): at least one of an epoxy (meth)acrylate resin and an unsaturated polyester resin;
(C-1): an inorganic fibrous filler having a cross-sectional area of 0.8 μm 2 to 38.5 μm 2 , an aspect ratio of 2.0 or higher and a length of less than 3 mm; and
(D): a polyisocyanate compound.
2. The molding material according to claim 1 , wherein the inorganic fibrous filler (C-1) also has a weight-average fiber length of 210 μm or less and includes fibers having a length of 350 μm or shorter in an amount of 85 mass % or more.
3. The molding material according to claim 1 , wherein the inorganic fibrous filler (C-1) is made of milled carbon fibers.
4. The molding material according to claim 1 , wherein the inorganic fibrous filler (C-1) is included in the molding material in an amount of 0.2 mass % or more.
5. The molding material according to claim 1 , wherein the length of the carbon fibers of the fiber substrate (A) is 5 to 60 mm.
6. The molding material according to claim 1 , further comprising:
(E): a polymerization initiator.
7. The molding material according to claim 6 , wherein the molding material comprises 30 to 70 mass % of the fiber substrate (A), 30 to 70 mass % of the at least one of the epoxy (meth)acrylate resin and the unsaturated polyester resin (B), 0.2 to 20 mass % of the inorganic fibrous filler (C-1), 5 to 20 mass % of the polyisocyanate compound (D), and 0.1 to 5 mass % of the polymerization initiator (E).
8. A sheet molding compound, comprising:
the molding material according to claim 1 .
9. A fiber-reinforced composite material, obtained by heat-compression molding the molding material according to claim 1 .
10. A fiber-reinforced composite material, obtained by heat-compression molding the sheet molding compound according to claim 8 .
11. The molding material according to claim 1 , wherein the inorganic fibrous filler (C-1) does not include a fiber having a length of 3 mm or longer.