Fiber-reinforced molded product and method for manufacturing the same

A fiber-reinforced molded product comprising a core material and a fiber-reinforced material layered on both surfaces of the core material,

• wherein the core material is formed by impregnating a thermosetting resin foam having open cells with a thermosetting resin, and curing the thermosetting resin while compressing the thermosetting resin foam, wherein a compression rate defined by the formula (A1) below is in a range of 200 to 5000%
• the fiber-reinforced material is formed by impregnating a carbon fiber fabric with a thermosetting resin and curing the thermosetting resin,
• a resin ratio, defined by the formula (B1) below, of the thermosetting resins with which the thermosetting resin foam and the carbon fiber fabric are impregnated is in a range of 50 to 80%,
• the core material and the fiber-reinforced material are formed as a unitary body by the curing of the thermosetting resin with which the thermosetting resin foam is impregnated and the thermosetting resin with which the fiber-reinforced material is impregnated, and
• a flexural modulus of the fiber-reinforced molded product is 30 GPa or more:
• (A1) compression rate={(thickness of thermosetting resin foam before compressing−thickness of core material)/thickness of core material}×100;
• and
• (B1) resin ratio={(total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins−total weight of thermosetting resin foam and carbon fiber fabric before impregnating with thermosetting resins)/total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins}×100.

A method for manufacturing a fiber-reinforced molded product having a core material and a fiber-reinforced material layered on both surfaces of the core material, the core material being formed by impregnating a thermosetting resin foam having open cells with a thermosetting resin, and curing the thermosetting resin while compressing the thermosetting resin foam, and the fiber-reinforced material being formed by impregnating a carbon fiber fabric with a thermosetting resin and curing the thermosetting resin, the method comprising:

• an impregnation step including impregnating a carbon fiber fabric with a thermosetting resin to provide an impregnated carbon fiber fabric;
• a laminating step including placing the impregnated carbon fiber fabric on both surfaces of a thermosetting resin foam having open cells to provide a laminated body;
• and
• a compression heating step including compressing and heating the laminated body,
• wherein, in the impregnation step, the impregnating is carried out such that a resin ratio defined by the formula (B2) below is in a range of 50 to 80%,
• wherein, in the compression heating step, the compressing is carried out such that a compression rate defined by the formula (A2) below is 200 to 5000%, and
• wherein the compression heating step includes impregnating the thermosetting resin foam with the thermosetting resin pressed out of the carbon fiber fabric, and causing a curing reaction in the thermosetting resin to form the core material and the fiber-reinforced material, thereby forming the core material and the fiber-reinforced material as a unitary body:
• (B2) resin ratio={(total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins−total weight of thermosetting resin foam and carbon fiber fabric before impregnating with thermosetting resins)/total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins}×100;
• and
• (A2) compression rate={(thickness of thermosetting resin foam before compressing−thickness of core material)/thickness of core material}×100.

A method for manufacturing a fiber-reinforced molded product having a core material and a fiber-reinforced material layered on both surfaces of the core material, the core material being formed by impregnating a thermosetting resin foam having open cells with a thermosetting resin, and curing the thermosetting resin while compressing the thermosetting resin foam, and the fiber-reinforced material being formed by impregnating a carbon fiber fabric with a thermosetting resin and curing the thermosetting resin, the method comprising:

• an impregnation step including impregnating a thermosetting resin foam having open cells with a thermosetting resin to provide an impregnated thermosetting resin foam;
• a laminating step including placing a carbon fiber fabric on both surfaces of the impregnated thermosetting resin foam to provide a laminated body;
• and
• a compression heating step including compressing and heating the laminated body,
• wherein, in the impregnation step, the impregnating is carried out such that a resin ratio defined by the formula (B3) below is in a range of 50 to 80%,
• wherein, in the compression heating step, the compressing is carried out such that a compression rate defined by the formula (A3) below is 200 to 5000%, and
• wherein the compression heating step includes impregnating the carbon fiber fabric with the thermosetting resin pressed out of the thermosetting resin foam, and causing a curing reaction in the thermosetting resin to form the core material and the fiber-reinforced material, thereby forming the core material and the fiber-reinforced material as a unitary body:
• (B3) resin ratio={(total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins−total weight of thermosetting resin foam and carbon fiber fabric before impregnating with thermosetting resins)/total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins}×100;
• and
• (A3) compression rate={(thickness of thermosetting resin foam before compressing−thickness of core material)/thickness of core material}×100.

A method for manufacturing a fiber-reinforced molded product having a core material and a fiber-reinforced material layered on both surfaces of the core material, the core material being formed by impregnating a thermosetting resin foam having open cells with a thermosetting resin, and curing the thermosetting resin while compressing the thermosetting resin foam, and the fiber-reinforced material being formed by impregnating a carbon fiber fabric with a thermosetting resin and curing the thermosetting resin, the method comprising:

• an impregnation step A including impregnating a thermosetting resin foam having open cells with a thermosetting resin A to produce an impregnated thermosetting resin foam;
• an impregnation step B including impregnating a carbon fiber fabric with a thermosetting resin B to provide an impregnated carbon fiber fabric;
• a laminating step including placing the impregnated carbon fiber fabric on both surfaces of the impregnated thermosetting resin foam to provide a laminated body;
• and
• a compression heating step including compressing and heating the laminated body,
• wherein, in the impregnation step A and the impregnation step B, the impregnating is carried out such that a resin ratio defined by the formula (B4) below is in a range of 50 to 80%,
• wherein, in the compression heating step, the compressing is carried out such that a compression rate defined by the formula (A4) below is 200 to 5000%, and
• wherein the compression heating step includes causing a curing reaction in the thermosetting resin A with which the thermosetting resin foam is impregnated and in the thermosetting resin B with which the carbon fiber fabric is impregnated while keeping them in contact with each other, thereby forming the core material and the fiber-reinforced material as a unitary body:
• (B4) resin ratio={(total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins−total weight of thermosetting resin foam and carbon fiber fabric before impregnating with thermosetting resins)/total weight of thermosetting resin foam and carbon fiber fabric after impregnating with thermosetting resins}×100;
• and
• (A4) compression rate={(thickness of thermosetting resin foam before compressing−thickness of core material)/thickness of core material}×100.