Mitsubishi Rayon Company, Limited

Mitsubishi Chemical Corporation

Mrc Composite Products Co., Ltd.

Mrc Composite Product Co., Ltd.

Tetsuya Atsumi

Tsutomu Ibuki

Ikuo Takiguchi

Kouji Shiga

Katsumi Anai

Takashi Kaneko

Manabu Kaneko

Masato Taguchi

Kenichi Watanabe

Tadayoshi Saitou

Tomoko Ishimoto

Youhei Miwa

Mikihiro Uchizono

Provided are an epoxy resin composition which contains an epoxy resin and a curing agent, and satisfies the following (1), (2), and (3):

Epoxy resin composition, and film, prepreg, and fiber-reinforced plastic using same

By completing curing in a short period of time even at low temperatures and using an epoxy resin composition as a matrix resin of a prepreg, it is possible to obtain a fiber-reinforced composite plastic product such as a fiber-reinforced tubular composite with excellent mechanical properties and, more particularly, excellent impact resistance. The epoxy resin composition includes A component, B component, C component, D component and E component, where the content rate of sulfur atoms is equal to or more than 0.2 wt % and equal to or less than 7 wt %, and the content rate of the C component is equal to or more than 1 wt % and equal to or less than 15 wt %. A component: epoxy resins, B component: reactive products of the epoxy resins and an amine compounds including the sulfur atom in a molecule (the unreacted epoxy resins and/or the amine compounds may be included), C component: polyamide compounds soluble in the A component, D component: urea compounds, and E component: dicyandiamide.

Epoxy resin composition and prepreg using the same, fiber-reinforced composite resin tubular body manufactured from the prepreg and manufacturing method therefor, and fiber-reinforced composite resin molded body

A shaft for a golf club comprises a plurality of fiber-reinforced resin layers. A plurality of circumferentially oriented metal wires are provided at intervals of 1 mm to 4 mm in an axial direction of the shaft having a length in an axial direction of more than 100 mm and less than 300 mm and being centered at a position of 3.25&#xd7;10mm from a larger-diameter end of the shaft.

Shaft for golf club

Golf club shaft

A golf club shaft is 35-50 percent lighter than a conventional shaft while maintaining the outer diameter and structural characteristics of conventional shafts. The shaft has at least four layers of fiber reinforced material. The fiber reinforced layers are from innermost to outermost: a first angled layer; a first straight layer; a second angled layer; and a second straight layer. The angled layers are formed by bonding together two materials, each with fibers aligned in different directions. The second angled layer maintains the proper strength and rigidity of the shaft while keeping the shaft as light weight as possible. Aligning the second layer's fibers at an angle of 35-75 degrees with respect to the longitudinal direction of the shaft ensures proper weight and strength characteristics of the shaft. The resulting shaft is light-weight and exhibits the flexural rigidity, flexural strength, torsional rigidity, torsional strength, and crushing strength of conventional shafts.

Shaft for light-weight golf clubs

A golf club shaft having an optimal set of materials and sloped sections provides appropriately high rigidity, ease of use, and is inexpensive and easy to manufacture. A sloped section expands toward a grip end of the shaft. The sloped section has a slope gradient from 15/1000 to 35/1000 and a length from 200 to 350 mm. The outer diameter of the grip end is from 18 to 25 mm. On the side of the sloped section toward an end, there is formed a semi-sloped section with a slope gradient from 4/1000 to 13/1000. A kick point is formed at a position from 40% to 46% from the small-diameter end relative to the total shaft length. The number of required parts is small while production is simple. The shaft is light, has appropriate hardness, and high rigidity at the grip. Furthermore, the strength of the shaft is balanced and provides a good feel when hitting a ball. Production of the golf club shaft can be accomplished with standard materials such as fiber-reinforced resins. By wrapping a fiber-reinforced resin around a mandrel and rolling the material on a base which is heated to an optimal temperature, the strength and rigidity of the shaft can be optimized. Multiple layers can be overlaid to provide any desired strength and rigidity required. The rolled shaft is then heated to set the resin and produce a golf club shaft of optimal performance and reduced cost.

Golf club shaft and method for manufacturing same

Growing community of inventors

Toyohashi, Japan

Tetsuya Atsumi