JP2012201067A - Prepreg for robot fork, method of manufacturing the same, and method of manufacturing robot fork - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement fiber prepreg for a robot fork, which is light in weight, has high strength, and is inexpensive.SOLUTION: The prepreg for a robot fork is a sheet-like prepreg formed by containing reinforcement fiber and thermosetting resin. The reinforcement fiber is carbon fiber having a tensile elastic modulus 350 GPa or higher, and fineness 200-1,000 tex, and is oriented in one direction so that a carbon fiber mass per unit area becomes 250-450 g/m. Mass content of the thermosetting resin in the sheet-like prepreg is 15-30 mass%. A sum of lengths of impregnated parts of the sheet-like prepreg is 5% or more of a total length of the sheet-like prepreg. A release paper is arranged on at least one surface of the sheet-like prepreg. Peel resistance of the sheet-like prepreg and the release paper is 150-6,000 mN/25 mm. Composite compressive strength is 700 MPa or higher.

Description

  The present invention relates to a sheet-like reinforcing fiber prepreg, which is an intermediate substrate of a fiber-reinforced composite material that is lightweight, has excellent bending rigidity, and bending strength, and is used for industrial robot forks, and a method for manufacturing the same.

  In a manufacturing process of a liquid crystal display device, a color filter, and the like, when processing a glass substrate or the like, the substrate is transported using a robot fork. In recent years, with the increase in size of liquid crystal display devices, it has been required to transport a large glass substrate at the time of manufacture, and it is necessary to increase the length of the robot fork and increase the load transport capability.

  However, when a large glass substrate is loaded on a long robot fork, the amount of deflection at the free end of the robot fork inevitably increases, and further, the weight of the robot fork itself increases due to the increase in length. Therefore, the amount of deflection due to its own weight also increases. If the amount of deflection at the free end of the robot fork increases, the amount of deformation increases when supporting or transporting the glass substrate, and it is necessary to increase the vibration or reduce the transport speed to prevent it. It will interfere with sex.

  That is, the robot fork is required to reduce the weight of the fork itself and minimize the deflection of the fork, that is, high rigidity and strength. In order to meet these requirements, carbon fiber reinforced plastic (CFRP), which is highly rigid and lightweight in recent years, has been used, and a method of orienting carbon fibers in the longitudinal direction of the robot fork is used to increase bending rigidity. It is common (for example, patent document 1).

  However, in the present situation where the size is further increased, not only the weight of the substrate to be transported increases, but also the CFRP material used so far makes the robot fork itself heavy, and the deflection due to its own weight increases. There is a problem of end. When the deflection becomes large, not only the bending rigidity but also the bending strength needs to be further improved, and when the robot fork becomes heavy, the load on the robot drive system also increases, which affects the design and cost of the robot itself. I came.

  Moreover, in patent document 2, it is a robot fork whose cross section is a hollow rectangle, Comprising: Four surfaces which comprise this hollow rectangle are each equipped with a unidirectional fiber reinforced plastic (FRP) layer, and with respect to the loading surface at the time of use By reducing the thickness of the FRP layer that constitutes two surfaces that are substantially perpendicular to each other, the weight of the FRP layer is made smaller than the thickness of the loading surface, and a layer in which reinforcing fibers are oriented obliquely is included in the substantially right-angled layer. The method of reducing the shear deformation at the fork fixed end while increasing the bending rigidity is used.

  In this method, pitch-based carbon fibers with a high modulus of elasticity are used in order to obtain a certain rigidity. However, pitch-based carbon fibers are impregnated with resin and heat-cured when compared with polyacrylonitrile (PAN) -based carbon fibers. Since the composite has a low compressive strength, there is a problem that the bending strength is lowered due to insufficient compressive strength.

  Patent Document 3 relates to a robot forklift characterized by having heat resistance, outgas resistance characteristics, and conductivity while being light, having high bending rigidity and excellent vibration damping. There is a description that the carbon fiber to be used may be either PAN-based or pitch-based, but a method for covering the decrease in elastic modulus when using a PAN-based carbon fiber having a lower elastic modulus than the pitch-based one is disclosed. It has not been.

  From the above background, prepregs using carbon fibers that are rigid and lightweight, especially pitch-based carbon fibers with high elastic modulus, have excellent vibration damping properties in terms of their characteristics. There was a need for further improvements.

JP 2002-292592 A JP 2007-83388 A JP 2005-187198 A

  In view of the problems of the background art, the present invention maintains the same rigidity as a robot fork composed of a prepreg using a conventional carbon fiber, is lightweight, has good workability, and has higher strength than conventional. It is an object of the present invention to provide a sheet-like reinforcing fiber prepreg and a manufacturing method thereof for obtaining a low-cost robot fork.

This invention for achieving the said subject consists of following (1)-(4). That is,
(1) A sheet-like prepreg comprising a reinforcing fiber and a thermosetting resin, wherein the reinforcing fiber is a carbon fiber having a tensile modulus of 350 GPa or more and a fineness of 200 to 1000 tex, and has a unit area The carbon fiber mass per direction is oriented in one direction so as to be 250 to 450 g / m ² , the mass content of the thermosetting resin in the sheet-like prepreg is 15 to 30% by mass, and the sheet The sum of the lengths of the impregnated portions when measured by the following peel tape method of the sheet-like prepreg is 5% or more of the total length of the sheet-like prepreg, and a release paper is disposed on at least one side of the sheet-like prepreg The peeling resistance between the sheet-like prepreg and the release paper measured by the following method is 150 to 6000 mN / 25 mm, and the coating resistance measured by the following method is used. A prepreg for a robot fork having a compressive strength of 700 MPa or more.

(2) The carbon fiber has a filament number of 1000 to 15000 / yarn, a single yarn diameter of 3.5 to 6 μm in terms of a circular cross section, and a yarn width of 1 × 10 ⁻⁴ to The prepreg for a robot fork according to (1), which is 1.5 × 10 ⁻³ mm / filament.

(3) A carbon fiber having a tensile modulus of 350 GPa or more and a fineness of 200 to 1000 tex, and a composite fiber having a composite compressive strength measured by the following method of 700 MPa or more, is 250 to 450 g per unit area in one direction. / M ² , a resin film having a thermosetting resin and release paper on one side, and a resin film or release paper having a thermosetting resin and release paper on the other side A robot fork having a step of impregnating the thermosetting resin into the carbon fibers arranged in one direction by pressurizing with a heating roll group at a heating temperature of 90 to 130 ° C. and a linear pressure of 1500 to 30000 N / m. Of manufacturing prepreg for use.

  (4) A robot fork manufacturing method obtained using a core material having a hollow rectangular cross section and having a uniform taper, the core material having an outer diameter width of 60 to 120 mm and a high outer diameter at the tip. Is a core having a rectangular cross-section with a length of 10 to 30 mm, a height of the root portion of 30 to 60 mm, and a length of the tapered portion of 2800 to 3200 mm. For the robot fork according to (1) or (2), a prepreg layer is disposed, and a carbon fiber cloth prepreg is disposed on the innermost periphery and / or outermost periphery, and the middle layer of the upper and lower surfaces in the longitudinal direction of the core material. The prepreg or the prepreg for a robot fork manufactured by the method of (3) is laminated, and the carbon fiber cloth prepreg and the laminated thickness of the prepreg for the robot fork in the longitudinal direction are laminated. Total and 2~4mm of, and including the core material, after covering the laminated prepreg bag film, heat-curing, comprising the step of removing the core, a manufacturing method of a robot fork.

<Composite compression strength>
The composite compressive strength defined in the present invention is measured by the following method.

  That is, the sheet-like prepreg according to the present invention is cut, the number of layers is adjusted so as to be the closest to 1 mm thickness, the layers are laminated in the 0 ° direction, and heated in an autoclave according to the recommended curing profile of the resin used. Cured to obtain a molded body. The dimensions of the molded product and the 0 ° compressive strength (compressed strength in the axial direction of the molded product) of the molded product obtained in accordance with JIS-K7076 (1991) “In-plane compression test method of carbon fiber reinforced plastic” And the volume content of the fiber is calculated in terms of a value of 60%.

<Peeling resistance>
The peel strength between the sheet-like prepreg and the release paper defined in the present invention is measured by the following method.

  That is, a sheet-like prepreg carrying a release paper is cut into a strip shape having a width of 25 mm and a length of 300 mm with the carbon fiber direction as the length direction to obtain a test piece. Next, as shown in FIG. 1, the test piece 1 is folded using a double-sided adhesive tape having a size that can cover the entire test piece (for example, a double-sided tape T4000 manufactured by Sony Chemical Co., Ltd., width 50 mm). The release paper is pasted on the stainless steel support 2 having an angle θ of 165 °. Next, as shown in FIG. 2, the support 2 is mounted on the lower chuck 5 (fixed) of the tensile tester, and the peeling end of the release paper 4b that has been peeled off about 10 mm from the prepreg 4a in advance by the clip 6, Attached to the upper chuck 8 (movable) via the metal wire 7, pulls the release paper 4b at a pulling speed of 200 mm / min in an atmosphere of 23 ° C. and 50% RH, and peels it off from the prepreg 4a. Record above. Then, the top of the load crest is read from the higher five points and the bottom of the load valley is read from the lower five points, and a simple average value of these 10 points of load is obtained to obtain the peel strength. As the tensile tester, for example, a universal tensile tester such as Tensilon UTM-4L manufactured by Toyo Baldwin can be used.

<Peel tape method impregnation length>
The peel tape method impregnation length defined in the present invention is measured by the following method. That is, a sample cut in the entire width direction of a prepreg sheet having a width of 1000 mm is used as a test piece, and the test piece is tested. Adhesion after adhering from both sides of the test piece using an adhesive tape of a size that can cover the entire piece (for example, Nitto Denko Corporation, trade name: Dumplone Ace II, 50 mm × 60 m) A part where the carbon fibers in the prepreg are peeled in the layer by peeling off the tape and a part where the carbon fiber is peeled off without being peeled in the layer can be observed. The former is referred to as “unimpregnated portion” and the latter is referred to as “impregnated portion”. By this method, the length of the impregnated part is measured, and the ratio in the width direction of the test piece is calculated.

  According to the present invention, by using carbon fibers having specific characteristics, by reducing the resin content relative to the mass of carbon fibers oriented in one direction, the mechanical properties of the obtained sheet-like prepreg can be exhibited highly, While maintaining the lightness, the rigidity equivalent to that of a robot fork formed by molding a conventional carbon fiber prepreg can be maintained. Furthermore, since the composite formed by molding such a sheet-like prepreg has a high compressive strength, the bending strength is improved and the composite is suitably used for manufacturing a robot fork required to transport a large substrate.

It is a schematic perspective view of the sample used for the measurement of the peeling strength of a sheet-like prepreg. It is the schematic which shows the state which is measuring the peeling strength of a sheet-like prepreg. It is a schematic side view of the apparatus for manufacturing the carbon fiber prepreg which concerns on one embodiment of this invention.

  The carbon fiber used in the present invention is characterized in that the strand tensile elastic modulus determined by JIS R 7608 (2007) is 350 GPa or more, preferably 400 GPa or more, and preferably 650 GPa or less.

  The compressive strength (composite compressive strength) in the reinforcing fiber axis direction of the fiber composite material obtained by molding the sheet-like prepreg according to the present invention is required to be 700 MPa or more, and preferably 950 MPa or more. By setting the composite compressive strength to 700 MPa or more, the bending strength of the robot fork is increased, and the resultant load resistance is increased.

  As the carbon fiber, polyacrylonitrile-based (hereinafter sometimes referred to as PAN-based) carbon fiber and pitch-based carbon fiber are known, and the carbon fiber has a high tensile elastic modulus of 350 GPa or more, and this. Since it is necessary to make the composite compressive strength of the reinforcing fiber composite material obtained by molding a sheet-shaped prepreg using a high pressure of 700 MPa or more, it is preferable to use a PAN-based carbon fiber in the present invention.

  If the tensile modulus of the carbon fiber is 350 GPa or more and the composite compressive strength is 700 MPa or more, sufficient rigidity of the robot fork required for transporting a large glass substrate material such as 2800 mm × 3000 mm size can be obtained. it can. Furthermore, it is preferable that the tensile elasticity modulus of the carbon fiber is 650 GPa or less because the adhesion between the carbon fiber and the resin can be made within a certain range. In addition, the carbon fiber used in the present invention is required to have a fineness of 200 to 1000 tex, and preferably 400 to 600 tex.

Furthermore, in the sheet-like prepreg according to the present invention, the carbon fibers are oriented in one direction so that the mass of the carbon fibers per unit area in the prepreg is 250 to 450 g / m ² . By setting it to 250 g / m ² or more, the laminating time at the time of robot fork molding can be shortened, and by setting it to 450 g / m ² or less, productivity and impregnation of thermosetting resin at the time of prepreg processing are within a range where there is no problem. can do. From such a viewpoint, 300 to 400 g / m ² is more preferable.

  In this invention, the mass content rate which occupies for this sheet-like prepreg of the thermosetting resin used for a sheet-like prepreg needs to be 15-30 mass%. By setting the mass content of the thermosetting resin to 30% or less, the elastic modulus of the molded product can be exhibited high without using yarns with extremely high tensile elastic modulus, and the weight of the sheet-like prepreg is increased. , And an increase in the weight of the robot fork obtained by molding it can also be avoided. In addition, by setting the mass content of the thermosetting resin to 15% or more, it is possible to prevent unimpregnation between the carbon fiber bundles that occurs when the mass content is too low, and the incident occurs along with it. Generation of voids can also be suppressed.

  A prepreg having a mass content of 15-30% by mass of such a thermosetting resin is a carbon fiber having a single yarn diameter of 3.5-6 μm, more preferably 4-5.5 μm, in terms of a circular cross section. It is preferable to use it. Converting the diameter of a single yarn into a circular cross section means calculating the equivalent value of the diameter by calculating the cross section of the single yarn as a circle from the fineness of the carbon fiber bundle, the number of single yarns per bundle, and the density. In particular, in a sheet-like prepreg having a thermosetting resin mass content of 15 to 30% by mass, by making the carbon fiber diameter 6 μm or less, the expansibility of the carbon fiber during impregnation is improved, and When the thickness is 3.5 μm or more, it is possible to prevent generation of fluff during the production of carbon fiber or prepreg, and it is preferable because a sheet-like prepreg having a low mass content of the thermosetting resin can be produced with high quality. Further, the carbon fiber used in the present invention preferably has a filament number in the range of 1000 to 15000 / yarn. By setting the number of filaments to 1000 or more, productivity at the time of prepreg formation can be kept high, and by setting it to 15000 or less, even when producing a sheet-like prepreg with a low thermosetting resin mass impregnation rate. Can spread easily.

The yarn width of the carbon fiber used in the present invention is preferably 1 × 10 ^{−4 to} 1.5 × 10 ⁻³ mm / filament. By setting the yarn width of the carbon fiber to 1 × 10 ⁻⁴ mm / filament or more, it is possible to suppress single yarn breakage of the fiber that is peculiar to the high elastic yarn, and 1.5 × 10 ⁻³ mm / filament or less It is preferable because the thickness of the overlap between the carbon fibers can be further reduced, and a sheet-like prepreg having excellent surface smoothness can be produced.

  In the sheet-like prepreg according to the present invention, release paper is disposed on at least one surface thereof, and it is essential that the peeling resistance between the sheet-like prepreg and the release paper is 150 to 6000 mN / 25 mm. If the peel resistance between the sheet-like prepreg and the release paper is within the above range, the local content from the release paper that occurs when the adhesion between the sheet-like prepreg and the release paper, which is a low mass content of the thermosetting resin, is weak. Such as detachment and floating can be suppressed, and damage to the sheet-like prepreg during peeling and peeling in the layer direction of the release paper due to excessively high peel strength can be prevented. The range of preferable peeling resistance is 180 to 4000 N / 25 mm. After determining the type and amount of thermosetting resin used mainly for sheet-shaped prepregs, set the peel strength of the release agent used for the release paper, and select those within the above range. can do. As a preferable release paper, a silicone-coated prepreg process paper can be used, and it can be prepared by adjusting the composition and amount of silicone used as a release agent and conditions such as drying and heat treatment after coating.

  In the sheet-like prepreg according to the present invention, it is essential that the length of the impregnated portion measured by the above-described peel tape method is 5% or more of the entire length of the sheet-like prepreg. By setting the impregnation property to 5% or more, it is possible to obtain a robot fork having good impregnation property, good moldability and few voids. The impregnation property is preferably in the range of 5 to 20%. The length of the impregnation part can be set by adjusting the temperature, pressure, speed, etc. in prepreg formation after determining the type of fiber and resin.

That is, the sheet-like prepreg according to the present invention is a carbon fiber having a tensile modulus of 350 GPa or more and a fineness of 200 to 1000 tex, and a carbon fiber having a composite compressive strength measured by the above method of 700 MPa or more is unidirectional. resin arranged in per unit area 250~450g / m ^2, a resin film comprising a thermosetting resin and a release paper on one side, comprising a thermosetting resin and release paper on the other side to A film or release paper is placed, and the thermosetting resin is impregnated into the unidirectionally arranged carbon fibers by applying a heating temperature of 90 to 130 ° C. and a linear pressure of 1500 to 30000 N / m in a heating roll group. In the step of producing a prepreg having a mass content of 15 to 30% by mass in the sheet-like prepreg of the thermosetting resin. In this case, it can be set by adjusting the heating temperature, pressure and the like according to the specified ranges of the carbon fiber and the thermosetting resin.

  As the thermosetting resin used in the present invention, any resin used for the production of ordinary carbon fiber prepregs can be used. For example, epoxy resin, phenol resin, polyimide resin, cyanate resin, unsaturated polyester resin And vinyl ester resins. Among them, an epoxy resin having a curing temperature of 150 ° C. or less is preferable from the viewpoint of handleability and product mechanical properties, and fine particles made of rubber or resin are added to a thermosetting resin as a modifier in a part of the composition. Alternatively, a thermoplastic resin dissolved or dispersed in a thermosetting resin may be used.

  The thermosetting resin is preferably a thermosetting resin having a minimum viscosity of 0.1 to 300 poise. The minimum viscosity is more preferably 10 to 100 poise. If the viscosity is within this range, it is possible to prevent the thermosetting resin from protruding from the sheet-like prepreg during prepreg processing. In addition, unimpregnation of the single yarn between the carbon fiber bundles can be prevented, whereby the tearing between the carbon fiber bundles when the sheet-like prepreg is peeled from the release paper at the time of molding can be suppressed. Here, the resin viscosity is measured using a dynamic viscoelasticity method, and as a measuring device, for example, an RDA-II type device manufactured by Rheometrics, Inc. can be used. The minimum viscosity in the present invention means that when the temperature is raised from room temperature, the resin viscosity is once lowered and then the viscosity is increased, but this means the minimum viscosity value in this profile. Moreover, the temperature which shows this minimum viscosity is defined as minimum viscosity temperature. These characteristics are measured using such an apparatus under the conditions of vibration: 3.14 radians / second, heating rate: 1.5 ° C./min, parallel plate with a radius of 25 mm, and gap: 1.0 mm. .

  As described above, the sheet-like prepreg according to the present invention was obtained by applying the thermosetting resin to the release paper so that the resin mass content of the final prepreg was 15 to 30% by weight. After sandwiching the resin film from both surfaces of the carbon fiber oriented in the one direction, the resin film is pressed against at least one heating roll group, and the heating temperature is 90 ° C. to 130 ° C., the linear pressure is 1500 to 30000 N / It can manufacture suitably by the method of pressurizing with m. The resin film is not necessarily from both surfaces, and one side may be a resin film and the other side may be only release paper.

  When producing a sheet-like prepreg having a high mass content of carbon fibers per unit area and a low mass content of thermosetting resin, which is the object of the present invention, when impregnating carbon fibers with a thermosetting resin, By setting the processing temperature and the impregnation pressure within the above-described ranges, the resin can be sufficiently transferred, and poor impregnation in the sheet-like prepreg can be suppressed. Further, the thermosetting resin can be prevented from protruding from the sheet-like prepreg due to the processing temperature and the impregnation pressure being too high. From such a viewpoint, the sheet-like prepreg of the present invention is heated at a heating temperature of 90 ° C. to 130 ° C., and is pressurized at 1500 to 30000 N / m, thereby peeling the above-described sheet-like prepreg and release paper, and Occurrence of impregnation failure can be suppressed, and a sheet-like prepreg having good quality can be suitably manufactured. More preferably, the processing speed is 3 to 20 m / min, the heating temperature is 100 ° C. to 120 ° C., and the applied pressure is 3000 to 10000 N / m. In order to make the sum of the lengths of the impregnated portion measured by the peel tape method described above 5% or more of the total length of the prepreg, the impregnation temperature is adjusted to be the minimum viscosity of the thermosetting resin. The pressure and processing speed can be achieved by adjusting the thermosetting resin so that the amount of protrusion of the thermosetting resin from the sheet-like carbon fiber to the lower release paper at the time of impregnation is 1 to 20 mm.

  The robot fork obtained by using the sheet-like prepreg according to the present invention has a rectangular portion in cross section, for example, a reinforcing fiber prepreg is wound or pasted around a metal core, and a predetermined shape is formed on the outer peripheral surface thereof. The outer mold can be pressed and heated and pressurized with an autoclave or the like, and then the core material can be extracted.

The robot fork according to the present invention has an outer diameter width of 60 to 120 mm, an outer diameter height of 10 to 30 mm at the tip, a root portion height of 30 to 60 mm, and a tapered portion length of 2800 to 3200 mm. A core material having a rectangular cross section may be used, and it is preferable to wrap a cross prepreg sheet around the innermost periphery and / or outermost periphery for the purpose of reinforcing the rigidity in the non-fiber direction and facilitating the extraction of the core material. The cross prepreg sheet is an uncured sheet in which a matrix resin is impregnated with reinforcing fibers woven in a plurality of directions, and the reinforcing fibers are preferably woven carbon fibers, glass fibers, aramid fibers, and the like. . As a particularly preferred cross prepreg, a cross prepreg obtained by impregnating a plain woven cloth material (CO 6343B manufactured by Toray Industries, Inc.) having an elastic modulus of 230 GPa and a filament number of 3000 with a basis weight of 198 g / m ^{2 with} the thermosetting resin, etc. Is mentioned. The robot fork according to the present invention has a total thickness of 2 to 4 mm for the carbon fiber cloth prepregs positioned on the upper and lower surfaces in the longitudinal direction of the fork and the sheet-like prepregs according to the present invention disposed in the middle layer thereof. Is preferred. Stiffness necessary to transport a large glass substrate can be obtained by setting the total thickness to 2 mm or more, and suppressing the weight increase of the robot fork itself by setting the total thickness to 4 mm or less. it can. A sheet-like unidirectional prepreg in which a PAN-based carbon fiber having a normal elastic modulus is impregnated with a resin is laminated on the side surface of the hollow rectangular cross section so that the total thickness of the side surface is about 2 mm. Preferred unidirectional prepregs include T700SC-12K manufactured by Toray Industries, Inc., a tensile elastic modulus of 230 GPa, a mass per carbon fiber area of 300 g / m ² , and a resin mass content of 37%. The term “side surface” as used herein refers to a surface oriented in a direction perpendicular to the longitudinal direction of the robot fork.

  The robot fork according to the present invention can be manufactured by covering the prepreg laminated with the core material with a bag film, then heat-curing, and decentering the core material.

  Hereinafter, the present invention will be described with reference to examples.

(1) Materials used A. Carbon fiber Unless otherwise specified, carbon fiber has a tensile modulus of elasticity: 436 GPa, fineness: 445 tex, number of filaments: 12,000, fiber density of 1.84 g / cm ³ , and yarn width of 0.2 × 10 ⁻⁴ mm. Fiber was used.

B. Thermosetting resin
As the thermosetting resin, a resin composition prepared in advance with the following composition and having a minimum viscosity of 50 poise and a minimum viscosity temperature of 105 ° C. was used. Here, the resin viscosity is RDA-II type apparatus manufactured by Rheometrix Co., Ltd., operation mode: dynamic, vibration 3.14 radians / second, heating rate: 1.5 ° C./min, plate: parallel plate (radius 25 mm ), Gap: measured under the condition of 1.0 mm. The composition of the resin used is as follows.

(A) Base resin Bisphenol A type epoxy resin (jER828, manufactured by Mitsubishi Chemical Corporation)
Bisphenol A type epoxy resin (jER1001, manufactured by Mitsubishi Chemical Corporation)
Phenol novolac type epoxy resin (jER154, manufactured by Mitsubishi Chemical Corporation)
Polyvinyl formal (Vinyleck K, trade name, manufactured by Chisso Corporation)
Polymethylmethacrylate (Matsumoto Microsphere M, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
(B) Curing agent Dicyandiamide (jER Cure DICY7T, manufactured by Mitsubishi Chemical Corporation)
Omicure DDA5 (manufactured by PTI Japan)
(C) Curing accelerator 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU 99, manufactured by Hodogaya Chemical Co., Ltd.).

(2) Manufacturing method of sheet-like prepreg As shown in FIG. 3, the carbon fiber bundle 10 drawn out from the package 9 of a plurality of carbon fiber bundles is provided with a plurality of carbons via the alignment rolls 11 and 12 and the comb 13. The fiber bundles are aligned in parallel with each other in the form of a sheet to form the carbon fiber sheet 14.

  With respect to the carbon fiber sheet 14, an upper resin film 15 drawn out from a roll body 18 of the upper resin film is disposed on the upper surface side of the carbon fiber sheet 14 via the introduction rolls 16, 17, and the lower side The lower resin film 21 drawn out from the roll body 27 of the resin film is disposed on the lower surface side of the carbon fiber sheet 14 through the introduction rolls 19 and 20. Thus, the carbon fiber sheet 14 sandwiched between the resin films 15 and 21 from both sides or one side is heated by the heater 22 and the resin applied to the resin film is heated and softened, and is nipped by the impregnating rolls 23 and 26. By being pressed, the carbon fiber sheet 14 is impregnated with the resin. The carbon fiber sheet 14 impregnated with the resin is wound up and collected as a roll body 29 at the position of the take-up rolls 24 and 25, and the release paper 28 on the upper side after the resin is transferred to the carbon fiber sheet 14 side. The carbon fiber sheet 14 impregnated with the resin is wound up as a roll body 31 together with a release paper carrying the lower resin film 21 as a carbon fiber prepreg 30. In such a manufacturing method, the carbon fiber is impregnated with a thermosetting resin by sandwiching a resin film from both surfaces of a sheet in which the carbon fiber is aligned in one direction with a width of 1000 mm, and press-contacting the heated roll group. A prepreg was produced.

(3) Evaluation items and measurement method Prepreg mass per unit area; g / m ²
A sheet-like prepreg having a width of 1000 mm, having a length of 500 mm and a width of 200 mm, cut at three points from the end in the width direction at 100 mm intervals, is used as a sample, and the average value of three points obtained by weighing the sample with a balance is used as a unit. It was set as the prepreg mass per area. The width direction here means a direction perpendicular to the fiber direction aligned in one direction of the sheet-like prepreg.

B. Resin mass content:%
From the sample, the resin mass content was calculated by the method of JIS K 7071 (1988).

C. Weight measurement In a hollow rectangular cross-section core material having a uniform taper with the outer diameter of the tip portion being 80 mm wide and 16 mm height and the outer diameter of the root portion being 80 mm width and 45 mm height, the length of the tapered portion is 3000 mm. A bar-shaped member was prepared. Cross prepreg A (resin mass content: 30%) obtained by impregnating the above-mentioned thermosetting resin into a plain woven cloth material (CO6343B, manufactured by Toray Industries, Inc.) having an elastic modulus of 230 GPa and having a filament number of 3000 and a basis weight of 198 g / m ² And prepreg B in which the PAN-based carbon fibers in the present invention are aligned in one direction and impregnated with the thermosetting resin (M46JB-12K manufactured by Toray Industries, Inc., tensile elastic modulus 436 GPa, mass per carbon fiber area 345 g / m ² Prepreg C (T700SC-12K manufactured by Toray Industries, Inc., tensile elastic modulus 230 GPa, carbon, which is PAN-based carbon fiber having a resin mass content of 20%) and a normal elastic modulus and impregnated with the thermosetting resin. mass 300 g / ^{m 2} per area of the fiber, a resin mass content 37%), the sheet-like prepreg B Wei direction was laminated structure arranged in a direction oriented in the longitudinal direction of the rod. One layer of prepreg A on the innermost and outermost periphery, and prepreg B on the intermediate layer in the longitudinal direction of the robot fork are stacked so that the total thickness of the layer is 2.3 mm, and the prepreg is stacked on the intermediate layer on the side of the robot fork. C was laminated so that the total lamination thickness was 2 mm, and the whole was covered with a bag film, then cured by heating, and the weight of the robot fork removed from the core was measured. The weights of Examples 2 to 9 and Comparative Examples 1 to 6 are expressed as a ratio (%) when the weight of Example 1 is 1.

D. Measurement of bending strength and bending elastic modulus of composite The bending strength of the composite in the present invention is measured by the following method. Cut the sheet-shaped prepreg, adjust the number of layers so that the entire thickness is closest to 2 mm, stack in the 0 ° direction, and heat cure in an autoclave according to the recommended curing profile of the resin used to obtain a molded body It was. The dimensions of the molded body and the 0 ° bending strength (bending strength in the axial direction of the molded body) of the molded body obtained by molding were measured according to ASTM D790 “Bending characteristics of plastics, reinforced plastics and electrical insulating materials”. .

Example 1
The above-mentioned impregnation apparatus sandwiches a resin film coated so that the resin mass content is 20% from both surfaces of a sheet aligned in one direction so that the carbon fiber mass per unit area is 345 g / m ^2. After passing through a hot plate and metal nip roll heated to 120 ° C. with a linear pressure of 5800 N / m, after cooling to 25 ° C., peel off the upper release paper, cover with a polyethylene cover film, and wind up A sheet-like prepreg was obtained. Measurement and confirmation of sheet-shaped prepreg basis weight, resin content, compressive strength, peel tape, peel strength, and weight, as shown in Table 1, to obtain a sheet-shaped prepreg with good quality, handling during molding, and good mechanical properties I was able to.

(Example 2)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that the carbon fiber mass per unit area was 251 g / m ² . As shown in Table 1, a sheet-like prepreg having good quality, handleability during molding, and mechanical properties could be obtained.

(Examples 3 to 6)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that the heating temperature was changed to 90 ° C., 130 ° C., or the pressure condition was changed to 4000 N / m or 30000 N / m. As shown in Table 1, a sheet-like prepreg having good quality, handleability during molding, and mechanical properties could be obtained.

(Example 7)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that carbon fibers having a carbon fiber count of 6000 and carbon fiber basis weight of 223 tex were used. As shown in Table 1, a sheet-like prepreg having good quality, handleability during molding, and mechanical properties could be obtained.

(Example 8)
A sheet was produced in the same manner as in Example 1 except that carbon fiber having a single fiber diameter of 6.4 μm, a carbon fiber density of 1.88 g / cm ³ , a carbon fiber basis weight of 720 tex, and a tensile elastic modulus of 450 GPa was used. A prepreg was obtained. As shown in Table 1, a sheet-like prepreg having good quality and good handleability during molding could be obtained. As the mechanical properties, the compressive strength was slightly low, but it was in a range where there was no problem in transporting the glass substrate.

Example 9
A sheet was produced in the same manner as in Example 1 except that carbon fiber having a single fiber diameter of 5.2 μm, a carbon fiber density of 1.77 g / cm ³ , a carbon fiber basis weight of 450 tex, and a tensile elastic modulus of 392 GPa was used. A prepreg was obtained. As shown in Table 1, a sheet-like prepreg having good quality and good handleability during molding could be obtained. As the mechanical properties, the flexural modulus was slightly low, but the vibration damping property was in the range where there was no problem.

(Comparative Example 1)
The sheet-like prepreg used is a pitch-based prepreg carbon fiber, the single yarn diameter is 10.0 μm, the fiber density is 2.12 g / cm ³ , the carbon fiber basis weight is 2000 tex, the tensile elastic modulus is 640 GPa, and the mass per area of the carbon fiber is 340 g / m ² , resin mass content 30%), the same lamination thickness as in Example 1, molded by the same method, and evaluated for mechanical properties. As a result, a prepreg having low compression strength and inferior 0 ° bending strength was obtained. Obtained.

(Comparative Example 2)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that the resin content in the sheet-like prepreg was 35% and a release paper having a peel resistance of 160 mN / 25 mm from the prepreg was used. When the laminated thickness of the sheet-like prepreg was the same as that of Example 1 and was molded by the same method, a robot fork having an increased weight was obtained.

(Comparative Example 3)
A sheet-like prepreg was obtained by the same method as in Example 1 except that the resin content in the sheet-like prepreg was 10%. In the step of peeling the sheet-like prepreg from the release paper at the time of molding, between the prepreg layers As a result, peeling occurred and molding could not be performed.

(Comparative Example 4)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that the linear pressure during processing of the sheet-like prepreg was set to 900 N / m. The length of the impregnated portion measured with the peel tape measured by the above-mentioned method is 3%, and in the step of peeling the sheet-like prepreg from the release paper at the time of molding, peeling occurs between the prepreg layers, and molding is possible. could not.

(Comparative Example 5)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that a release paper having a peeling resistance of 100 mN / 25 mm with respect to the prepreg was used. However, the sheet-like prepreg was peeled off immediately and was inferior in handling during molding. .

(Comparative Example 6)
A sheet-like prepreg was obtained in the same manner as in Example 1 except that a release paper having a peel resistance of 8000 mN / 25 mm was used, but cracking in the fiber layer occurred before peeling from the release paper at the time of molding. Thus, the prepreg was inferior in handleability during molding.

(Comparative Example 7)
Example 1 except that a carbon fiber having 18000 carbon fiber filaments, a single yarn diameter of 5.5 μm, a carbon fiber density of 1.73 g / cm ³ , a carbon fiber basis weight of 745 tex, and a tensile elastic modulus of 294 GPa was used. The sheet-like prepreg was obtained by the same method as above, but the bending elastic modulus was inferior and the vibration damping property was large.

  The present invention can be applied to a robot fork for transferring a glass substrate for liquid crystal display and for transferring a semiconductor substrate. Moreover, the application range is not limited to these.

1 Test piece (prepreg)
2 Test piece support 3 Double-sided tape 4a Unidirectional prepreg 4b Release paper 5 Lower chuck 6 Clip 7 Metal wire 8 Upper chuck 9 Carbon fiber bundle package 10 Carbon fiber bundle 11 Alignment roll 12 Alignment roll 13 Comb 14 Carbon Fiber sheet 15 Upper resin film 16 Introduction roll 17 Introduction roll 18 Upper resin film roll body 19 Introduction roll 20 Introduction roll 21 Lower resin film 22 Heater 23 Impregnation roll 24 Take-up roll 25 Take-up roll 26 Impregnation roll 27 Lower resin film roll 28 Upper release paper 29 Upper release paper roll 30 Carbon fiber prepreg 31 Carbon fiber prepreg roll

Claims (4)

A sheet-like prepreg comprising a reinforcing fiber and a thermosetting resin, wherein the reinforcing fiber is a carbon fiber having a tensile elastic modulus of 350 GPa or more and a fineness of 200 to 1000 tex, and is a carbon per unit area The fiber mass is oriented in one direction so as to be 250 to 450 g / m ² , the mass content of the thermosetting resin in the sheet prepreg is 15 to 30% by mass, and the sheet prepreg The sum of the lengths of the impregnated portions when measured by the peel tape method described in the specification is 5% or more of the total length of the sheet-like prepreg, and a release paper is disposed on at least one side of the sheet-like prepreg. The peel resistance of the sheet-like prepreg and the release paper measured by the method described in the specification is 150 to 6000 mN / 25 mm, and A prepreg for a robot fork having a composite compressive strength measured by a method described in a document of 700 MPa or more. The carbon fiber has a filament number of 1000 to 15000 / yarn, a single yarn diameter of 3.5 to 6 μm in terms of a circular cross section, and a yarn width of 1 × 10 ^{−4 to} 1.5. The prepreg for a robot fork according to claim 1, wherein the prepreg is × 10 ⁻³ mm / filament. Carbon fiber having a tensile elastic modulus of 350 GPa or more and a fineness of 200 to 1000 tex, and a composite fiber having a composite compressive strength measured by the method described in the specification of 700 MPa or more is unidirectionally treated with 250 to A resin film having a thermosetting resin and release paper on one side and a resin film or release paper having a thermosetting resin and release paper on the other side are arranged at 450 g / m ^2. And a step of impregnating the thermosetting resin into the carbon fibers arranged in one direction by pressurizing with a heating roll group at a heating temperature of 90 to 130 ° C. and a linear pressure of 1500 to 30000 N / m. Manufacturing method of prepreg for forks. A method for producing a robot fork having a hollow rectangular cross section and having a uniform taper, the core material having an outer diameter width of 60 to 120 mm and an outer diameter height of 10 mm at the tip. It is a core material having a rectangular cross section with a height of 30 to 60 mm, a root part height of 30 to 60 mm, and a taper part length of 2800 to 3200 mm, and unidirectional prepreg layers are arranged on four surfaces of the core material, respectively. The carbon fiber cloth prepreg is disposed on the innermost periphery and / or the outermost periphery, and the prepreg for a robot fork according to claim 1 or 3 is formed on the middle layer of the upper and lower surfaces in the longitudinal direction of the core member. The robot folk prepreg manufactured by the method is laminated, and the total thickness of the carbon fiber cross prepreg and the robot fork prepreg in the longitudinal direction is 2 to 2. And mm, and including the core material, after covered with laminated prepreg bag film, heated and cured, having a leaving core to process, manufacturing method of a robot fork.

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