Production method for fibre-reinforced composite material, prepreg, particle-containing resin composition, and fibre-reinforced composite material

1. A production method for a fiber-reinforced composite material comprising:

stacking a prepreg plurally to obtain a prepreg-stacked body; and

heating the prepreg-stacked body to cure a resin,

wherein the prepreg comprises:

a reinforcing fiber layer including reinforcing fibers and a resin composition with which a space between fibers of the reinforcing fibers is impregnated and which contains (A) a benzoxazine resin, (B) an epoxy resin, and (C) a curing agent having 2 or more phenolic hydroxy groups in a molecule; and

a surface layer provided on at least one surface of the reinforcing fiber layer and containing (A) a benzoxazine resin, (B) an epoxy resin, (C) a curing agent having 2 or more phenolic hydroxy groups in a molecule, and (D) polyamide resin particles having an average particle size of 5 to 50 μm,

wherein the polyamide resin particles include (D1) first polyamide resin particles and (D2) second polyamide resin particles having a higher melting temperature measured in a composition constituting the surface layer than the melting temperature of the first polyamide resin particles

wherein a melting temperature of the (D1) first polyamide resin particles measured in the composition constituting the surface layer is 120 to 170° C.; and

a melting temperature of the (D2) second polyamide resin particles measured in the composition constituting the surface layer is 175 to 220° C.

2. The production method for a fiber-reinforced composite material according to claim 1 ,

wherein, when it is assumed that the melting temperature of the (D1) first polyamide resin particles measured in the composition constituting the surface layer is M 1 ° C. and

the melting temperature of the (D2) second polyamide resin particles measured in the composition constituting the surface layer is M 2 ° C.,

a value of (M 2 −M 1 ) is 5 or more.

3. The production method for a fiber-reinforced composite material according to claim 1 , wherein the surface layer contains 65 to 78 parts by mass of the (A) component, 22 to 35 parts by mass of the (B) component, 5 to 20 parts by mass of the (C) component, and 15 to 45 parts by mass of the (D) component when it is assumed that a total amount of the (A) component and the (B) component is 100 parts by mass.

4. The production method for a fiber-reinforced composite material according to claim 1 , wherein the (D1) first polyamide resin particles are polyamide 12 resin particles and the (D2) second polyamide resin particles are polyamide 1010 resin particles.

5. A prepreg comprising:

a reinforcing fiber layer including reinforcing fibers and a resin composition with which a space between fibers of the reinforcing fibers is impregnated and which contains (A) a benzoxazine resin, (B) an epoxy resin, and (C) a curing agent having 2 or more phenolic hydroxy groups in a molecule; and

a surface layer provided on at least one surface of the reinforcing fiber layer and containing (A) a benzoxazine resin, (B) an epoxy resin, (C) a curing agent having 2 or more phenolic hydroxy groups in a molecule, and (D) polyamide resin particles having an average particle size of 5 to 50 μm,

wherein the polyamide resin particles include (D1) first polyamide resin particles and (D2) second polyamide resin particles having a higher melting temperature measured in a composition constituting the surface layer than the melting temperature of the first polyamide resin particles,

wherein a melting temperature of the (D1) first polyamide resin particles measured in the composition constituting the surface layer is 120 to 170° C.; and

a melting temperature of the (D2) second polyamide resin particles measured in the composition constituting the surface layer is 175 to 220° C.

6. The prepreg according to claim 5 ,

wherein, when it is assumed that the melting temperature of the (D1) first polyamide resin particles measured in the composition constituting the surface layer is M 1 ° C. and

the melting temperature of the (D2) second polyamide resin particles measured in the composition constituting the surface layer is M 2 ° C.,

a value of (M 2 −M 1 ) is 5 or more.

7. The prepreg according to claim 5 , wherein the surface layer contains 65 to 78 parts by mass of the (A) component, 22 to 35 parts by mass of the (B) component, 5 to 20 parts by mass of the (C) component, and 15 to 45 parts by mass of the (D) component when it is assumed that a total amount of the (A) component and the (B) component is 100 parts by mass.

8. A fiber-reinforced composite material obtained by

stacking the prepreg according to claim 5 plurally, forming a plurality of sequential reinforcing layers and surface layers, and

performing heating under increased pressure.

9. The fiber-reinforced composite material according to claim 8 , wherein the (D1) first polyamide resin particles are polyamide 12 resin particles and the (D2) second polyamide resin particles are polyamide 1010 resin particles.

10. The fiber-reinforced composite material according to claim 8 , wherein the volume proportion {C 1 /(C 1 +C 2 )}×100 is 70% by volume or more, wherein:

(C 1 ) is the volume of polyamide resin contained between sequential reinforcing layers, and

(C2) is volume of polyamide resin contained in the reinforcing layers.

11. The fiber-reinforced composite material according to claim 8 , wherein the mode I interlaminar fracture toughness value (G1c) measured in accordance with ASTM D5528 is 300 J/m 2 or more.

12. The prepreg according to claim 5 , wherein the (D1) first polyamide resin particles are polyamide 12 resin particles and the (D2) second polyamide resin particles are polyamide 1010 resin particles.

13. A resin composition containing particles, comprising:

(A) a benzoxazine resin;

(B) an epoxy resin;

(C) a curing agent having 2 or more phenolic hydroxy groups in a molecule; and

(D) polyamide resin particles having an average particle size of 5 to 50 μm,

wherein the polyamide resin particles include polyamide 12 resin particles and polyamide 1010 resin particles.

14. The resin composition containing particles according to claim 13 , wherein the resin composition contains 65 to 78 parts by mass of the (A) component, 22 to 35 parts by mass of the (B) component, 5 to 20 parts by mass of the (C) component, and 15 to 45 parts by mass of the (D) component when it is assumed that a total amount of the (A) component and the (B) component is 100 parts by mass.