Toray Industries, Inc.

Ichiro Taketa

Eisuke Wadahara

Narumichi Sato

Yuzo Fujita

Shiori Kawamoto

Akihiko Kitano

Yuta Naito

Masahiro Yamanouchi

Nobuyuki Arai

Yoshitaka Koyama

Reo Takaiwa

Takafumi Hashimoto

Hiroaki Sakata

Tetsuya Motohashi

Takuya Karaki

Chiasa Sato

Maurice Geli

Hiroaki Matsutani

A towpreg that is easy to unwind from a bobbin, has good width accuracy after unwinding and can produce a composite material with excellent heat resistance, and a resin composition that gives such a towpreg. A towpreg is characterized by being impregnated with an epoxy resin that contains an epoxy resin which is solid at 23° C. in an amount of 30 parts or more in 100 parts by mass of total epoxy resin components, contains a polyfunctional amine type epoxy resin which is liquid at 23° C. in an amount of 20 parts or more in 100 parts by mass of total epoxy resin components, and further contains a clay mineral.

Resin composition for carbon fiber composite material, towpreg

The present invention relates to a method for producing a towpreg by impregnating a plurality of fiber bundles with a resin to form a single towpreg, characterized in that the method comprises providing a stock of fiber bundles for preparing a towpreg; measuring a basis weight for each of the fiber bundles of said stock before impregnation by a resin; defining groups of fiber bundles from said stock based of the fiber basis weight, thereby providing determined fiber bundles; predicting a fiber basis weight of a towpreg when the plurality of fiber bundles is combined to form the towpreg, thereby providing a predicted fiber basis weight of a towpreg; and producing the towpreg using a combination of fiber bundles from all groups of determined fiber bundles in which the predicted fiber basis weight of the towpreg is in a range determined from a target value of a basis weight of a towpreg.

Method for producing towpreg

An intermediate base material is provided that is excellent in the conformity to three-dimensional shapes and that, when formed into a fiber reinforced plastic, develops good surface quality and high mechanical properties. According to one aspect, an incised prepreg is provided that has, in at least a partial region in a prepreg that contains unidirectionally oriented reinforcing fibers and a resin, a plurality of incisions that divide reinforcing fibers, wherein, in the case where a population is made up of the numbers of incisions contained in ten small circular regions of 10 mm in diameter randomly selected in the aforementioned region, a mean value for the population is 10 or greater and a coefficient of variation therefor is within 20%.

Incised prepreg, cross-ply laminate, and production method for incised prepreg

A substantially flat-plate-shaped laminated base material has at least a layer-shaped body &#x3b1; and a layer-shaped body &#x3b2; are layered or disposed side by side, the layer-shaped body &#x3b1; having one or more cut prepregs A in which reinforcing fibers oriented in one direction are impregnated with a resin composition, the volume fraction of fiber is 45-65%, and at least a portion of the reinforcing fibers are segmented into a fiber length of 10-300 mm by a plurality of cuts, and the layer-shaped body &#x3b2; having one or more base materials B in which reinforcing fibers having a fiber length in the range of 10-300 mm are impregnated with a resin composition.

Laminated base material and method of manufacturing fiber-reinforced plastic

A random mat material including fiber bundles, said fiber bundles including fibers having an average fiber length of 5 to 100 mm, and having an average number N of fibers in the fiber bundle that satisfies: wherein D is the average diameter of fibers in the fiber bundle, expressed in micrometers, and the standard deviation SDof the number of fibers in a fiber bundle satisfies:1,000&#x3c;SD&#x3c;6,000wherein at an end of the fiber bundle, the number of the fibers in a fiber bundle becomes less from center to edge of the fiber bundle in a fiber direction.

Carbon fiber random mat and carbon fiber composite material

A molded article of a fiber-reinforced resin contains at least a bundled aggregate [A] of discontinuous reinforcing fibers and a matrix resin [M], wherein the average layer thickness h in the molded article of the fiber-reinforced resin is 100 &#x3bc;m or less and the CV value of the average layer thickness h is 40% or less; and a compression molding method therefor. It is possible to reliably and greatly reduce the occurrence of stress concentration in the molded article and to thereby achieve higher mechanical properties and further reduce variation in the mechanical properties.

Molded article of fiber-reinforced resin and compression molding method therefor

An intermediate base material has high handleability and shape conformity to complicated shapes and serves to perform high-yield production, even by low pressure molding, of fiber reinforced plastic material that do not suffer from significant generation of molding defects, such as creases and voids, that can cause a decrease in strength and that has good mechanical characteristics, decreased variations therein, and high dimensional stability. The prepreg includes a layer containing reinforcement fibers impregnated with a resin composition and the impregnation rate with the resin composition in the prepreg is in a predetermined range. It is characterized by being an incised prepreg having a plurality of incisions, being at least partly formed of reinforcement fibers with a predetermined fiber length, and having a reinforcement fiber content by volume Vf in a predetermined range.

Notched pre-preg and notched pre-preg sheet

A prepreg includes a fiber layer containing unidirectionally arranged carbon fibers impregnated with a thermosetting resin and a resin layer existing on at least one side of the fiber layer and containing a thermosetting resin and a thermoplastic resin insoluble in the thermosetting resin. The prepreg contains carbon fibers having an areal weight of fibers of 120 to 300 g/mand has a weight fraction of resin of 25 to 50 mass %. An extreme value frequency of a surface geometry along a straight line perpendicular to the fibers of the prepreg is 30 points/mm or less when the prepreg has been exposed, for 24 hours, to a temperature at which a coefficient of interlayer friction is the lowest. Using sheets of the prepreg which are laid up, the coefficient of interlayer friction of the prepreg is measured at 10&#xb0; C. intervals in a temperature range of 40 to 80&#xb0; C. under the conditions: a pulling speed of 0.2 mm/min, a perpendicular stress of 0.1 bar, and a pulling displacement of 1 mm. The prepreg is suitable for aircraft structural members that exhibits high impact strength as a fiber-reinforced plastic and has excellent drapeability when formed into a prepreg laminate which is made to conform to a three dimensional shape.

Prepreg and method for manufacturing same

A process is capable of producing a high-quality fiber-reinforced plastic with good yield in a short molding cycle time despite being atmospheric pressure molding. The process characterized uses local contact heating to give different temperature conditions to produce a fiber-reinforced plastic by atmospheric pressure molding from a fiber-reinforced material which contains a reinforcing fiber impregnated with a thermosetting resin composition.

Process of producing fiber-reinforced plastic

Provided is a prepreg including: a fiber layer containing unidirectionally arranged carbon fibers impregnated with a first thermosetting resin; and a resin layer disposed on at least one side of the fiber layer and containing a second thermosetting resin and a thermoplastic resin that is insoluble in the second thermosetting resin. The prepreg is configured such that the areal weight of fibers and the weight fraction of resin in the prepreg are 120 to 300 g/mand 25 to 50 mass %, respectively, and in the case where a plurality of prepregs are laid up, and the coefficient of interlayer friction is measured every 10&#xb0; C. in a temperature range of 40 to 100&#xb0; C. at a pull-out speed of 0.2 mm/min under a perpendicular stress of 0.8 bar, the temperature at which the coefficient of interlayer friction is 0.02 or less is present within a temperature range of 40 to 100&#xb0; C. The prepreg exhibits high impact strength when formed into a fiber-reinforced plastic suitable for an aircraft structural member, and the prepreg also has excellent drapeability when a prepreg laminate is made to conform to a three dimensional shape.

Prepreg

A composite prepreg base includes a raw prepreg base comprising a fiber sheet including discontinuous reinforcing fibers arranged in one direction and having a fiber length of 1-300 mm and a matrix resin infiltrated into the fiber sheet; and an additional resin layer formed on at least one surface of the raw prepreg base. The composite prepreg base is produced by a process including (i) the step of preparing the raw prepreg base and (ii) the step of forming an additional resin layer on at least one surface of the raw prepreg base prepared. A layered base includes two or more sheets of the composite prepreg base which have been superposed so that the additional resin layer is present on at least one surface; and a fiber-reinforced plastic formed by heating and pressing the layered base.

Process for producing composite prepreg base, layered base, and fiber-reinforced plastic

A laminated base material includes a lamination and integration of prepreg base materials each of which includes many reinforcing fibers arranged substantially in one direction and a matrix resin adhered to the reinforcing fibers, wherein at least one of the laminated prepreg base materials is formed with a prepreg base material having, throughout its whole surface, many incisions each extending in a direction crossing the reinforcing fibers, substantially all of the reinforcing fibers divided by incisions, and wherein a length L of each of reinforcing fiber segments formed by the incisions is 10 to 100 mm, a thickness H of the prepreg base material is 30 to 300 &#x3bc;m, and a fiber volume content Vf of the reinforcing fibers is 45 to 65% and arranging directions of the reinforcing fibers between one and another laminated prepreg base materials have at least two directions different each other.

Prepreg base material, layered base material, fiber-reinforced plastic, process for producing prepreg base material, and process for producing fiber-reinforced plastic

A composite prepreg base which includes a raw prepreg base comprising a fiber sheet comprising discontinuous reinforcing fibers arranged in one direction and having a fiber length of 1-300 mm and a matrix resin infiltrated into the fiber sheet; and an additional resin layer formed on at least one surface of the raw prepreg base. The composite prepreg base is produced by a process including (i) the step of preparing the raw prepreg base and (ii) the step of forming an additional resin layer on at least one surface of the raw prepreg base prepared. Also provided are: a layered base including two or more sheets of the composite prepreg base which have been superposed so that the additional resin layer is present on at least one surface; and a fiber-reinforced plastic formed by heating and pressing the layered base.

A prepreg base material includes reinforcing fibers arranged substantially in one direction and a matrix resin between the reinforcing fibers, wherein the prepreg base material has substantially throughout its entire surface incisions, each incision extending in a direction substantially crossing the reinforcing fibers, wherein substantially all of the reinforcing fibers are divided by the incisions, a length (L) of each of reinforcing fiber segments formed by the incisions is in the range of 10 to 100 mm, a thickness H of the prepreg base material is in the range of 30 to 300 &#x3bc;m, and a fiber volume content by Vf of the reinforcing fibers is in the range of 45 to 65%.

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Ehime, Japan

Ichiro Taketa