TOW PREPREG, COMPOSITE MATERIAL PRESSURE VESSEL, AND METHOD FOR MANUFACTURING SAME

1 . A tow prepreg, made by impregnating a reinforcing fiber bundle with a matrix resin composition comprising:

(A): an epoxy resin

(B): an epoxy resin curing agent; and

(C′): a pre-gelatinizing agent with a minimum viscosity temperature of 110° C. or lower,

wherein the minimum viscosity temperature is determined to be a temperature obtained at the minimum viscosity that appears on the highest temperature side when a sample is prepared by adding and dispersing homogeneously 10 parts by mass of the pre-gelatinizing agent (C′) to 100 parts by mass of a bisphenol-A epoxy resin with an epoxy equivalent weight of 190±6 g/eq to obtain a mixture, and by dissolving 10 parts by mass of a boron trichloride-octylamine complex into the mixture, and when the minimum viscosity of the sample is measured by increasing the temperature at a rate of 2° C./min.

2 . The tow prepreg according to claim 1 , wherein the pre-gelatinizing agent (C′) consists of core-shell particles.

3 . The tow prepreg according to claim 2 , wherein the core-shell particles are structured to have a core layer, which is a polymer made by polymerizing (meth)acrylate, and a shell layer, which is a polymer made by polymerizing at least one selected from the group consisting of a (meth)acrylate, a functional group-containing (meth)acrylate and a carboxyl group-containing vinyl monomer.

4 . The tow prepreg according to claim 1 , wherein an original particle shape is not observed in any magnification when the pre-gelatinizing agent (C′) is treated as follows:

a sample, which is prepared by adding and dispersing homogeneously 10 parts by mass of the pre-gelatinizing agent (C′) to 100 parts by mass of the bisphenol-A epoxy resin with an epoxy equivalent weight of 190±6 g/eq to obtain a mixture, and by dissolving 10 parts by mass of a boron trichloride-amine complex into the mixture, is poured into a 3 mm-thick molding frame and cured for 2 hours at 110° C. to obtain a 3 mm-thick cured resin plate;

the 3 mm-thick cured resin plate is fractured the same as in measuring the fracture toughness value of a cured resin in accordance with ASTM D5045; and

a fractured surface of the cured resin piece is observed at a magnification of 1000˜10000 times with a scanning electron microscope.

5 . The tow prepreg according to claim 1 , wherein the epoxy resin curing agent (B) is a boron trihalide-amine complex.

6 . The tow prepreg according to claim 1 , wherein the epoxy resin curing agent (B) is a boron trichloride-amine complex.

7 . The tow prepreg according to claim 1 , wherein a viscosity of the matrix resin composition at 30° C. is set at 5 Pa·s to 300 Pa·s.

8 . The tow prepreg according to claim 1 , wherein relative to 100 parts by mass of the matrix resin composition, a content of the epoxy resin (A) is set at 30 to 96.5 parts by mass, a content of the epoxy resin curing agent (B) is set at 0.5 to 50 parts by mass, and the content of the pre-gelatinizing agent (C′) is set at 3 to 20 parts by mass.

9 . The tow prepreg according to claim 1 , wherein the reinforcing fiber bundle is a carbon fiber bundle.

10 . A composite material pressure vessel, manufactured from the tow prepreg according to claim 1 .

11 . The composite material pressure vessel according to claim 10 , wherein the composite material pressure vessel is manufactured by winding the tow prepreg on a liner.

12 . A composite material pressure vessel, manufactured from a tow prepreg formed by impregnating a reinforcing fiber bundle with a matrix resin composition comprising:

(A): an epoxy resin;

(B): an epoxy resin curing agent; and

(C′): a pre-gelatinizing agent with a minimum viscosity temperature of 110° C. or lower,

wherein the minimum viscosity temperature is determined to be a temperature obtained at the minimum viscosity that appears on the highest temperature side when a sample is prepared by adding and dispersing homogeneously 10 parts by mass of the pre-gelatinizing agent (C′) to 100 parts by mass of a bisphenol-A epoxy resin with an epoxy equivalent weight of 190±6 g/eq to obtain a mixture, and by dissolving 10 parts by mass of a boron trichloride-octylamine complex into the mixture, and when the minimum viscosity of the sample is measured by increasing the temperature at a rate of 2° C./min.

13 . A method for manufacturing a composite material pressure vessel, the method comprising:

preparing a resin-impregnated reinforcing fiber bundle by impregnating a reinforcing fiber bundle with a matrix resin composition comprising

(A): an epoxy resin,

(B): an epoxy resin curing agent, and

(C′): a pre-gelatinizing agent with a minimum viscosity temperature of 110° C. or lower;

forming a tow prepreg by winding the resin-impregnated reinforcing fiber bundle on a bobbin;

unwinding pulling out tow prepreg from the bobbin;

obtaining a pressure vessel intermediate by filament-winding unwound tow prepreg on a liner; and

curing the matrix resin composition of the resin-impregnated reinforcing fiber bundle by applying heat on the pressure vessel intermediate

wherein the minimum viscosity temperature is determined to be a temperature obtained at the minimum viscosity that appears on the highest temperature side when a sample is prepared by adding and dispersing homogeneously 10 parts by mass of the pre-gelatinizing agent (C′) to 100 parts by mass of a bisphenol-A epoxy resin with an epoxy equivalent weight of 190±6 g/eq to obtain a mixture, and by dissolving 10 parts by mass of a boron trichloride-octylamine complex into the mixture, and when the minimum viscosity of the sample is measured by increasing the temperature at a rate of 2° C./min.

14 . A method for manufacturing a composite material pressure vessel, the method comprising:

forming a resin-impregnated reinforcing fiber bundle by impregnating a reinforcing fiber bundle with a matrix resin composition comprising

(A): an epoxy resin,

(B): an epoxy resin curing agent, and

(C′): a pre-gelatinizing agent with a minimum viscosity temperature of 110° C. or lower;

obtaining a pressure vessel intermediate by filament-winding the resin-impregnated reinforcing fiber bundle on a liner; and

curing the matrix resin composition contained in the resin-impregnated reinforcing fiber bundle by applying heat on the pressure vessel intermediate

wherein the minimum viscosity temperature is determined to be a temperature obtained at the minimum viscosity that appears on the highest temperature side when a sample is prepared by adding and dispersing homogeneously 10 parts by mass of the pre-gelatinizing agent (C′) to 100 parts by mass of a bisphenol-A epoxy resin with an epoxy equivalent weight of 190±6 g/eq to obtain a mixture, and by dissolving 10 parts by mass of a boron trichloride-octylamine complex into the mixture, and when the minimum viscosity of the sample is measured by increasing the temperature at a rate of 2° C./min.

15 . (canceled)