JP-7856806-B2 - Fiber-reinforced resin composite sheet, fiber-reinforced resin composite material, and resin molded product comprising the same

JP7856806B2JP 7856806 B2JP7856806 B2JP 7856806B2JP-7856806-B2

Inventors

金森尚哲
兼岩秀和
長谷川敬洋
中野結
佐藤史織

Assignees

フクビ化学工業株式会社

Dates

Publication Date: 20260511
Application Date: 20250226
Priority Date: 20200421

Claims (6)

A fiber-reinforced resin composite sheet comprising a flame-retardant resin film made of a thermoplastic resin composition having a glass transition temperature Tg of 90°C or higher, and a plurality of carbon fibers in which multiple carbon fibers opened from a carbon fiber bundle are oriented in the same direction and approximately half of each carbon fiber is impregnated into the flame- retardant resin film. The carbon fibers are impregnated in a manner that is exposed on both surfaces of the flame-retardant resin film, with approximately half of the fibers remaining unimpregnated. The flammability classification of the flame-retardant resin film determined in the UL94VTM combustion test compliant with the ASTM D4804 standard is VTM-0. The volume content Vf of the carbon fiber is 30% or more and 65% or less. The thickness of the fiber-reinforced resin composite sheet is 20 μm or more and 80 μm or less. The flammability classification of the fiber-reinforced resin composite sheet determined in the UL94-5V flammability test compliant with the ASTM D5048 standard is 5V-A or 5V-B. The thermoplastic resin composition comprises a polycarbonate resin and one or more flame retardants selected from halogen-based flame retardants, phosphorus-based flame retardants, silicone-based flame retardants, and inorganic flame retardants, and is a fiber-reinforced resin composite sheet.
The fiber-reinforced resin composite sheet according to claim 1 , wherein the thickness of the flame-retardant resin film is 5 μm or more and 50 μm or less.
The fiber-reinforced resin composite sheet according to claim 1 or 2 , wherein the thickness of the flame-retardant resin film is 5 μm or more and 40 μm or less, and the thickness of the fiber-reinforced resin composite sheet is 25 μm or more and 60 μm or less.
The fiber-reinforced resin composite sheet according to any one of claims 1 to 3 is a fiber-reinforced composite material in which multiple layers are laminated in the thickness direction, The fiber-reinforced composite material is a fiber-reinforced resin composite material in which a plurality of fiber-reinforced resin composite sheets are laminated in such a manner that the fiber directions of the carbon fibers have an angular difference in the two-dimensional direction.
The fiber-reinforced resin composite sheet according to any one of claims 1 to 3 is a fiber-reinforced composite material in which a plurality of chopped material shapes are laminated in the thickness direction, The chopped material is formed such that the fiber-reinforced resin composite sheet has a rectangle with a short side length of 2 mm or more and a long side length of 2 mm or more and a long side length of 80 mm or less. The fiber-reinforced composite material is a fiber-reinforced resin composite material in which a plurality of the chopped materials are laminated in such a state that the fiber directions of the carbon fibers are random in two dimensions.
A resin molded article comprising the fiber-reinforced resin composite material according to claim 4 or 5 .

Description

This invention relates to a fiber-reinforced resin composite sheet containing a flame-retardant resin film and reinforcing fibers. Fiber-reinforced resin composites are widely used materials, from components for sports and leisure applications to components for industrial applications such as automobiles and aircraft. Furthermore, fiber-reinforced resin composites are manufactured using prepregs, which are intermediate materials in which reinforcing materials consisting of long fibers (continuous fibers), such as reinforcing fibers, are impregnated into a resin matrix. Specifically, molded fiber-reinforced resin composite products can be obtained by laminating multiple prepregs and then heating and curing them, or by heating and cooling them to solidify them. Conventionally, thermosetting resins have been widely used as the resin for prepregs in the manufacture of fiber-reinforced resin composites due to their superior strength and rigidity (see, for example, Patent Document 1). However, prepregs using thermosetting resins have problems such as low impact resistance and difficulty in secondary processing. To solve these problems, prepregs in which reinforcing fibers are impregnated using thermoplastic resin in the matrix resin have been widely developed. With such prepregs, melting by heating and solidifying by cooling is easy, resulting in excellent operability during prepreg molding, and effects such as reduced production time can be expected, leading to cost reduction. Furthermore, in recent years, fiber-reinforced resin composites have also been used as materials for casings and components of smartphones, tablets, laptops, video cameras, mobile devices, and other electrical or electronic equipment. Casings and components of electrical or electronic equipment are susceptible to ignition and combustion due to heat generated from within the equipment or exposure to high-temperature environments. To prevent such accidents, the prepreg material needs to be flame-retardant. Generally, thermosetting resins have excellent flame retardancy, but thermoplastic resins have poor flame retardancy, and few thermoplastic resins possess sufficient flame retardancy on their own without the addition of flame retardants (see, for example, Patent Document 2). Therefore, when manufacturing fiber-reinforced resin composites requiring flame retardancy, thermosetting resins are mainly used as the matrix resin. However, depending on the type of molded product, such as the casings or components of electrical or electronic equipment, good moldability may be required for fiber-reinforced resin composite materials (hereinafter also referred to as "fiber-reinforced resin composite sheets") in order to increase the degree of freedom in shape. On the other hand, fiber-reinforced resin composite sheets using thermoplastic resin for the matrix resin have superior moldability compared to fiber-reinforced resin composite sheets using thermosetting resin, but have the problem of inferior strength. Depending on the type of casings or components of electrical or electronic equipment as described above, strength, such as tensile strength, may also be required. Japanese Patent Application Publication No. 8-118381Japanese Patent Publication No. 2005-239939 Therefore, the present invention aims to provide a fiber-reinforced resin composite sheet that possesses excellent flame retardancy, good moldability, and sufficient tensile strength under high-temperature conditions. A fiber-reinforced resin composite sheet according to the first aspect of the present invention is a fiber-reinforced resin composite sheet comprising a flame-retardant resin film made of a thermoplastic resin composition having a glass transition temperature Tg of 90°C or higher, and a plurality of reinforcing fibers laminated on the flame-retardant resin film in a state in which a plurality of reinforcing fibers opened from a reinforcing fiber bundle are oriented in the same direction. The flammability classification of the flame-retardant resin film determined in the UL94VTM combustion test compliant with the ASTM D4804 standard is VTM-0. The volume content Vf of the reinforcing fiber is 30% or more and 65% or less. The thickness of the fiber-reinforced resin composite sheet is 20 μm or more and 100 μm or less. The flammability classification of the fiber-reinforced resin composite sheet, as determined in the UL94-5V flammability test compliant with the ASTM D5048 standard, is 5V-A or 5V-B. Figure 1 shows an example of a schematic configuration of a manufacturing apparatus for fiber-reinforced resin composite sheets in this embodiment.Figure 2 shows an example of a method for cutting chopped material from a fiber-reinforced resin composite sheet in this embodiment.Figure 3 is a diagram illustrating a method for producing a laminated chopped sheet, which is an example of a fiber-reinforced resin composite material in this embodiment.Figure 4 is a cross-sectional view of a lamin