PREPREG AND FIBER-REINFORCED COMPOSITE MATERIAL

• Main Authors: SANO, Kentaro, KURODA, Taiki, UCHIDA, Hiroyuki, KAMAE, Toshiya
• Format: Patent
• Language: English; French; German
• Published: 14.10.2020
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

Disclosed is a prepreg comprising an epoxy resin composition containing [A] an epoxy resin and [B] a curing agent, and a reinforcing fiber, wherein the epoxy resin composition satisfies the following conditions (a) to (e): (a) [A1] an epoxy resin represented by the general formula (I) is contained as the epoxy resin [A] in an amount of 50 to 100 parts by mass in 100 parts by mass of the entire epoxy resin, and [A1'] an epoxy resin satisfying an inequality: n ≥ 2 among the component [A1] is contained in an amount of 50 to 80 parts by mass in 100 parts by mass of the entire epoxy resin;wherein, in the general formula (I), R1, R2and R3each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 or more; (b) the entire epoxy resin has an average epoxy equivalent of 165 to 265 g/eq; (c) a water absorption coefficient as determined when the epoxy resin composition is stored in an atmosphere at 85°C and 95%RH for 2 hours is 3.0% by mass or less based on 100% by mass of the epoxy resin composition; (d) [B1] an aromatic urea is contained as [B] a curing agent; and (e) the content of [B2] dicyandiamide of the curing agent [B] is 0.5 part by mass or less based on 100 parts by mass of the entire epoxy resin. The present invention provides a prepreg which achieves both high heat resistance and low color and does not cause white spots on the surface of a molded article, and is capable of obtaining a fiber-reinforced composite material having excellent appearance and is also capable of obtaining a fiber-reinforced composite material having high heat resistance even when curing is performed under the condition where moisture can be mixed therein.