A racket frame ( 10 ) including a laminate having not less than two fiber reinforced resinous layers layered one upon another and one or more modified fiber reinforced resinous layers ( 20 ) each containing a modified resinous composition, as a matrix resin, having a loss factor (=tan δ) not less than 0.5 nor more than 3.0, when the loss factor is measured at a temperature of 0° C. to 10° C. and a frequency of 10 Hz. A weight of the modified fiber reinforced resinous layers ( 20 ) is set to not less than 1% nor more than 10% of a weight of the fiber reinforced resinous layers.
1. A racket frame comprising a laminate including not less than two fiber reinforced resinous layers layered one upon another and one or more modified fiber reinforced resinous layers each containing a modified resinous composition, as a matrix resin, having a loss factor (=tan δ) not less than 0.5 nor more than 3.0 when said loss factor is measured at a temperature of 0° C. to 10° C. and a frequency of 10 Hz,
wherein a weight of said modified fiber reinforced resinous layers is set to not less than 1% nor more than 10% of a weight of said fiber reinforced resinous layers.
2. The racket frame according to claim 1 , wherein supposing that an overall thickness of said laminate is 100%, one or more said modified fiber reinforced resinous layers are disposed in a thickness range not more than 20% of said overall thickness of said laminate at both sides of a central position of said thickness.
3. The racket frame according to claim 2 , wherein a thermosetting resin is used as a resinous component of said modified resinous composition; said thermosetting resin is used as a resinous component of said of a matrix resin of said fiber reinforced resinous layer; and said loss factor (=tan δ) of said modified resinous composition is set to not less than 0.01 nor more than 0.5.
4. The racket frame according to claim 3 , wherein said modified resinous composition contains epoxy resin and one or more activators selected from a compound having benzotriazole groups and a compound having diphenyl acrylate groups; and
a tensile modulus of elasticity of a reinforcing fiber of said modified fiber reinforced resinous layer is set to not less than 150 GPa nor more than 600 GPa.
5. The racket frame according to claim 3 , comprising a head part forming an outline of a ball-hitting face thereof and a bifurcated throat part connected to said head part, wherein supposing that said ball-hitting face is regarded as a clock surface and that a top position of said ball-hitting face is 12 o'clock, said modified fiber reinforced resinous layer is disposed at one position or two or more positions selected from among a first position in a range of 11 o'clock to one o'clock, a second position in a range of three o'clock to five o'clock (nine o'clock to seven o'clock), and a third position disposed at said left and right throat parts.
6. The racket frame according to claim 2 , wherein said modified resinous composition contains epoxy resin and one or more activators selected from a compound having benzotriazole groups and a compound having diphenyl acrylate groups; and
a tensile modulus of elasticity of a reinforcing fiber of said modified fiber reinforced resinous layer is set to not less than 150 GPa nor more than 600 GPa.
7. The racket frame according to claim 2 , comprising a head part forming an outline of a ball-hitting face thereof and a bifurcated throat part connected to said head part, wherein supposing that said ball-hitting face is regarded as a clock surface and that a top position of said ball-hitting face is 12 o'clock, said modified fiber reinforced resinous layer is disposed at one position or two or more positions selected from among a first position in a range of 11 o'clock to one o'clock, a second position in a range of three o'clock to five o'clock (nine o'clock to seven o'clock), and a third position disposed at said left and right throat parts.
8. The racket frame according to claim 1 , wherein a thermosetting resin is used as a resinous component of said modified resinous composition; said thermosetting resin is used as a resinous component of said of a matrix resin of said fiber reinforced resinous layer; and said loss factor (=tan δ) of said modified resinous composition is set to not less than 0.01 nor more than 0.5.
9. The racket frame according to claim 8 , wherein said modified resinous composition contains epoxy resin and one or more activators selected from a compound having benzotriazole groups and a compound having diphenyl acrylate groups; and
a tensile modulus of elasticity of a reinforcing fiber of said modified fiber reinforced resinous layer is set to not less than 150 GPa nor more than 600 GPa.
10. The racket frame according to claim 8 , comprising a head part forming an outline of a ball-hitting face thereof and a bifurcated throat part connected to said head part, wherein supposing that said ball-hitting face is regarded as a clock surface and that a top position of said ball-hitting face is 12 o'clock, said modified fiber reinforced resinous layer is disposed at one position or two or more positions selected from among a first position in a range of 11 o'clock to one o'clock, a second position in a range of three o'clock to five o'clock (nine o'clock to seven o'clock), and a third position disposed at said left and right throat parts.
11. The racket frame according to claim 1 , wherein said modified resinous composition contains epoxy resin and one or more activators selected from a compound having benzotriazole groups and a compound having diphenyl acrylate groups; and
a tensile modulus of elasticity of a reinforcing fiber of said modified fiber reinforced resinous layer is set to not less than 150 GPa nor more than 600 GPa.
12. The racket frame according to claim 11 , comprising a head part forming an outline of a ball-hitting face thereof and a bifurcated throat part connected to said head part, wherein supposing that said ball-hitting face is regarded as a clock surface and that a top position of said ball-hitting face is 12 o'clock, said modified fiber reinforced resinous layer is disposed at one position or two or more positions selected from among a first position in a range of 11 o'clock to one o'clock, a second position in a range of three o'clock to five o'clock (nine o'clock to seven o'clock), and a third position disposed at said left and right throat parts.
13. The racket frame according to claim 1 , comprising a head part forming an outline of a ball-hitting face thereof and a bifurcated throat part connected to said head part, wherein supposing that said ball-hitting face is regarded as a clock surface and that a top position of said ball-hitting face is 12 o'clock, said modified fiber reinforced resinous layer is disposed at one position or two or more positions selected from among a first position in a range of 11 o'clock to one o'clock, a second position in a range of three o'clock to five o'clock (nine o'clock to seven o'clock), and a third position disposed at said left and right throat parts.