JP2019015399A - Screw-like molding - Google Patents

Abstract

To provide a screw-like molding that is light in weight and prevents the occurrence of rust, has excellent shape stability to humidity or the like, and has also excellent durability and strength.SOLUTION: A screw-like molding is obtained by using a fiber-reinforced resin material containing a reinforced fiber and a thermoplastic epoxy resin. The thermoplastic epoxy resin is preferably a reactive epoxy resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thread-shaped molded body having a thread portion such as a screw or a bolt, and more particularly to a thread-shaped molded body molded using a fiber reinforced resin material obtained by adding a resin to a reinforced fiber.

  Conventionally, screws are used to fasten members such as wood, metal, or plastic in buildings, such as houses and bridges, transport equipment such as cars and airplanes, or manufacturing equipment such as machine tools. Alternatively, a fastening member such as a bolt is used. These fastening members are generally made of metal, but the metal fastening members have problems such as large mass and rusting.

  Therefore, as a fastening member that is lightweight and does not generate rust, there is known a thread-like molded body using a thermoplastic resin, specifically, a resin composition in which a carbon fiber is contained in a nylon resin (Patent Document 1).

JP-A-1-259932

  However, a thread-like molded body using a nylon resin has high hygroscopicity. For this reason, when the screw-shaped molded body using nylon resin is used as a screw and the members are screwed together, the screw repeatedly contracts and expands due to being wet by rain or the influence of humidity change in the usage environment. As a result, there was a problem that the screw shape changed and the screw loosened. In addition, the thread-shaped molded body using the nylon resin cannot exhibit a sufficient effect in terms of durability and strength.

  An object of the present invention is to provide a screw-like molded body that is lightweight, does not rust, has excellent form stability against water, moisture, and the like, and has excellent durability and strength.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have reached the present invention. That is, this invention is the following structures (1)-(7), for example.

  (1) The thread-shaped molded body according to the present invention uses a fiber reinforced resin material containing a reinforced fiber and a thermoplastic epoxy resin.

  (2) Furthermore, in the screw-shaped molded body according to the present invention, the thermoplastic epoxy resin may be a reactive epoxy resin.

  (3) Furthermore, in the screw-shaped molded body according to the present invention, the length of the reinforcing fiber is preferably greater than 1 mm.

  (4) Furthermore, in the screw-shaped molded body according to the present invention, the reinforcing fiber may be a three-dimensional fiber structure.

  (5) Furthermore, in the screw-shaped molded body according to the present invention, the reinforcing fiber may be a tubular braid or a knitted fabric.

  (6) Furthermore, the screw-shaped molded body according to the present invention may have a fiber volume ratio (Vf value) of 20 to 80%.

  (7) Furthermore, the screw-shaped molded body according to the present invention preferably has a tensile strength of 80 MPa or more when measured according to JIS Z2241.

  According to the present invention, it is possible to realize a screw-like molded body that is lightweight, does not rust, has excellent form stability against water, moisture, and the like, and has excellent durability and strength.

It is a photograph of the screw-like molded object of Example 3 (state in which two wood screws immediately after injection molding are connected).

  Embodiments of the present invention will be described below. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, and the like shown in the following embodiments are merely examples and do not limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  The thread-shaped molded body according to the present embodiment is molded using a fiber reinforced resin material including a reinforced fiber and a thermoplastic epoxy resin. Specifically, the thread-shaped molded body is formed using a fiber reinforced resin material obtained by adding a thermoplastic epoxy resin to a reinforced fiber.

  The screw-shaped molded body according to the present embodiment has a screw shape such as a screw thread portion or a screw groove portion (hereinafter collectively referred to as a screw thread portion). Specifically, examples of the screw-like molded body include a fastening member such as a bolt, a screw, a wood screw, or a nut, and a turnbuckle, but are not limited thereto.

(Embodiment 1)
First, the thread-shaped molded body according to Embodiment 1 will be described.

  The thread-shaped molded body according to the present embodiment is formed by processing a fiber reinforced resin material impregnated with a thermoplastic epoxy resin into a three-dimensional fiber structure in which a bundle of reinforcing fibers is knitted. . A thread portion is provided on the surface portion of the thread-shaped molded body. The thread portion may contain a thermoplastic epoxy resin, and may further have reinforcing fibers.

  The reinforcing fiber present in the thread portion of the thread-shaped molded body is a reinforcing fiber constituting the three-dimensional fiber structure, and may be a long fiber. The reinforcing fiber present in the thread portion is a part of the reinforcing fiber constituting the three-dimensional fiber structure, and the reinforcing fiber constituting the three-dimensional fiber structure is a long fiber, so that the thread is formed. Since the reinforcing fibers of the threaded portion and the main body adjacent to the threaded portion are connected while being entangled, the shear strength of the threaded portion is increased, and a thread-like molded body having excellent tensile strength is obtained. It is done.

  Also, since the thermoplastic epoxy resin has a lower moisture content than other resins such as nylon resin, the use of a thermoplastic epoxy resin for the fiber reinforced resin material constituting the thread-shaped molded body can cause contact with water and humidity. It is possible to prevent the shape from being deformed due to repeated contraction and expansion of the thread-shaped molded body due to exposure to an environment in which the wet state and the dry state in the opposite case are repeated. Thereby, even if it joins a member using a screw-shaped molded object, it can suppress that a screw-shaped molded object loosens. In addition, by using a thermoplastic epoxy resin having a low water content, a thread-like molded body having excellent durability and strength can be obtained.

  In addition, by using a thermoplastic epoxy resin for the fiber reinforced resin material used in the thread-shaped molded body, it is easy to heat and pressurize the fiber reinforced resin material when forming a screw shape such as a screw thread. A screw shape can be formed.

  Moreover, by using a reactive thermoplastic epoxy resin as the resin used for the fiber reinforced resin material, the thermoplastic epoxy resin is impregnated into the bundle of reinforcing fibers, and the reinforcing fiber is also a thermoplastic epoxy resin. At the same time, it is easy to move to the thread portion, and a thread portion having excellent durability and strength can be formed. In addition, since the thermoplastic epoxy resin has entered the bundle of reinforcing fibers present in the center of the thread-shaped molded body, the thread-shaped molded body itself is excellent in strength.

  The fiber volume ratio (Vf value) of the thread-shaped molded body according to the present embodiment is preferably 20 to 80%. Preferably, the fiber volume ratio of the thread-shaped molded body is 40% to 70%, and more preferably 50 to 60%. If the fiber volume fraction of the thread-shaped molded body is lower than the lower limit (for example, 20%), the thread portion may be made of only a thermoplastic epoxy resin, and the tensile strength of the obtained thread-shaped molded body may be decreased. is there. In addition, if the fiber volume ratio of the thread-shaped molded body exceeds the upper limit (for example, 80%), there is a possibility that the reinforcing fiber of the thread portion is cut when the thread portion is formed. There is a possibility that the tensile strength of the formed thread-shaped molded product is lowered.

  In addition, when using a screw-shaped molded object for a wood screw etc., the thread part of a screw-shaped molded object may be comprised only by the thermoplastic epoxy resin without including a reinforced fiber. The reason is that the thermoplastic epoxy resin itself is excellent in strength, and further, the adhesiveness between the thermoplastic epoxy resin and the reinforcing fibers (particularly carbon fibers) is strengthened. As a result, when the strength of a member to be joined such as wood is not so strong, it is possible to join without any problem even if a thread-like molded body that does not contain reinforcing fibers in the thread portion is used for wood screws or the like. it can.

  In addition, the Vf value which shows the fiber volume ratio of a screw-shaped molded object can be calculated | required by the following formula | equation 1.

Vf value (%) = (W−ρ ₃ × V) / [(ρ ₂ −ρ ₃ ) × V] × 100 Equation 1

In Equation 1, W is the mass (g) of the thread-shaped molded body, V is the volume (cm ³ ) of the thread-shaped molded body, ρ ₂ is the density of reinforcing fibers in the thread-shaped molded body (g / cm ³ ), ρ ₃ represents the density (g / cm ³ ) of the resin used for the thread-shaped molded body. The resin used for the thread-shaped molded body is a thermoplastic epoxy resin when the resin constituting the fiber reinforced resin material is only a thermoplastic epoxy resin, but the resin constituting the fiber reinforced resin material. When the resin includes a resin other than the thermoplastic epoxy resin, it means the whole resin including not only the thermoplastic epoxy resin but also a resin other than the thermoplastic epoxy resin.

  The screw-shaped molded body in the present embodiment is particularly excellent in tensile strength, and the tensile strength when measured according to JIS Z2241 is preferably 400 MPa or more, and more preferably 450 MPa or more. The upper limit is not particularly limited, but is about 1000 MPa. The tensile strength of commercially available aluminum alloy screws is about 250 MPa, and the tensile strength of screws using a commercially available composite material of carbon fiber and polyetheretherketone is about 150 MPa. . Therefore, the thread-shaped molded body in the present embodiment has superior strength compared to these commercially available screws.

  Note that the thread height, the thread pitch, the length, and the thickness of the thread portion of the thread-shaped formed body can be arbitrarily set according to the intended use and strength. .

  Hereinafter, the reinforced fiber and the thermoplastic epoxy resin used for the screw-shaped molded body in the present embodiment, and the fiber reinforced resin material composed of the reinforced fiber and the thermoplastic epoxy resin will be described in detail.

<Reinforcing fiber>
First, the reinforcing fiber used for the screw-shaped molded body in the present embodiment will be described.

  Examples of the reinforcing fibers include inorganic fibers, organic fibers, or those using a combination of these. Specifically, carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, glass fiber, basalt fiber, para-aramid fiber, meta-aramid fiber, ultrahigh molecular weight polyethylene fiber, polyarylate Examples thereof include fibers, PBO (polyparaphenylene benzoxazole) fibers, polyphenylene sulfide (PPS) fibers, polyimide fibers, fluorine fibers, and polyvinyl alcohol (PVA fibers).

  From the viewpoint of light weight and high strength, it is preferable to use carbon fibers as reinforcing fibers. Carbon fibers such as PAN-based or pitch-based carbon fibers can be used, but are not particularly limited. Among these, from the viewpoint of balance between strength and elastic modulus, it is preferable to use PAN-based carbon fibers as reinforcing fibers.

  Further, the reinforcing fiber is preferably a continuous long fiber. In this case, from the viewpoint of high strength, the length of the reinforcing fiber, which is a long fiber, depends on the length and thickness of the thread-shaped molded body, but is preferably not less than the total length of the thread-shaped molded body. The reinforcing fiber may be longer than at least the thread height of the thread portion.

  A plurality of reinforcing fibers are preferably bundled. From the viewpoint of workability and the strength of the obtained thread-shaped molded body, it is preferable to bundle 100 or more reinforcing fiber single fibers, and more preferably 1000 or more reinforcing fiber single fibers. The upper limit of the number of single fibers of the reinforcing fiber is not particularly limited, but is appropriately determined according to the strength (such as thickness and length) of the target screw-shaped molded body and the required tensile strength. Just choose.

  Specifically, as bundles of reinforcing fibers, for example, 1000 (1K) bundles, 3000 (3K) bundles, and 6000 (6K) bundles of carbon fibers supplied from a carbon fiber manufacturer. 12,000 (12K) bundled product, 24000 (24K) bundled product, 40000 (40K) bundled product, 50000 (50K) bundled product, 60000 (60K) bundled product, etc. Can be used. Also, as bundles of reinforcing fibers, carbon fiber bundles of Torayca (registered trademark) yarn (T700SC-24000, etc.) manufactured by Toray Industries, Inc., carbon fiber bundles of Pyrofil (registered trademark) manufactured by Mitsubishi Chemical Corporation, Toho Tenax A bundle of Tenax (registered trademark) carbon fibers of a corporation (integrated with Teijin Limited from April 1, 2018), or a bundle of a plurality of these may be used. In addition, these carbon fiber bundles are excellent in productivity because the carbon fiber bundles wound around a drum or the like can be used as they are without performing a fiber opening treatment or the like. Note that the bundle of carbon fibers may have been subjected to fiber opening treatment. In addition, the carbon fiber bundle may be a non-twisted yarn, a twisted yarn, or a flame-retardant yarn, but is a non-twisted yarn from the viewpoint of allowing the thermoplastic epoxy resin to enter the bundle of reinforcing fibers. Good.

<Thermoplastic epoxy resin>
Next, the thermoplastic epoxy resin used for the thread-shaped molded body in the present embodiment will be described.

  As the thermoplastic epoxy resin, preferably, a reaction such as curing is started or accelerated by adding an additive such as a curing agent, a catalyst, a polymerization initiator, a polymerization accelerator, or heating. It is preferable that it is a reactive resin that is cured, and it is also desirable that it is thermoplastic even after being cured. Therefore, it is preferable to use a thermoplastic epoxy resin having a linear molecular structure so that the form can be changed by heating and / or pressure treatment after curing.

  By using such a thermoplastic epoxy resin, after producing a fiber reinforced resin material composed of a reinforced fiber and a thermoplastic epoxy resin, using this fiber reinforced resin material, a screw shape of an arbitrary shape at an arbitrary time. A molded body can be produced. Thereby, the inventory risk of the screw-like molded object as finished products, such as a screw, can be reduced.

  Moreover, you may produce a fiber reinforced resin material using what mix | blended other thermoplastic resins with the thermoplastic epoxy resin in the range which does not deviate from the objective of this invention.

  Such a reactive thermoplastic epoxy resin is liquid at room temperature before being cured with a curing agent, or is in a state of being dissolved or dispersed in a solvent, so that a fiber-reinforced resin material is produced. In this case, the thermoplastic epoxy resin can be easily impregnated into the bundle of reinforcing fibers. Thereby, in the fiber reinforced resin material, since the thermoplastic epoxy resin exists even inside the bundle of reinforcing fibers, the reinforcing fiber and the thermoplastic epoxy resin are sufficiently intertwined (for example, in contact with each other or firmly It is in a close contact state. For this reason, the screw-shaped molded object in this Embodiment has the outstanding intensity | strength. Moreover, the fiber reinforced resin material using the reactive thermoplastic epoxy resin has thermoplasticity even after being cured by reacting the thermoplastic resin, and the thermoplastic epoxy resin reaches the inside of the bundle of reinforced fibers. Since the thermoplastic epoxy resin easily moves during the heating and / or pressurizing treatment and the reinforcing fiber also easily moves, the threaded portion having a predetermined shape can be easily formed. That is, the formability of the thread portion is excellent.

  In addition, reactive thermoplastic resins, including reactive thermoplastic epoxy resins, have a smaller molecular weight than the unreacted thermoplastic resin used by heating and melting, and are less fluid. After reaction, it can be polymerized to a number average molecular weight of, for example, 10,000 or more to 30,000 or more, and the state of crosslinking can be adjusted, and the strength, flexibility, or heat deformability can also be adjusted. Is possible.

  On the other hand, the thermoplastic resin used by being melted by heat is generally not easy to impregnate the inside of the fabric even if it is a fabric using a bundle of thin carbon fibers. In the case of applying to a three-dimensional fiber structure in which reinforcing fibers are densely present, the thermoplastic resin is present only in the vicinity of the surface of the three-dimensional fiber structure. On the other hand, as in the present embodiment, by using a reactive thermoplastic epoxy resin, even in a three-dimensional fiber structure in which reinforcing fibers are densely present, the inside of the three-dimensional fiber structure Since the epoxy resin can be reacted and polymerized after impregnating the low molecular weight thermoplastic epoxy resin with excellent fluidity to the back, the resulting screw-shaped molded product has an internal structure of the screw-shaped molded product. Furthermore, the thermoplastic epoxy resin can be impregnated into the inside of the bundle of reinforcing fibers deep inside the thread-shaped molded body.

  In addition, the chemical structure of the thermoplastic resin may change after the reaction. For example, the thermoplastic epoxy resin becomes a phenoxy resin after the reaction. That is, the reactive thermoplastic epoxy resin in the present embodiment includes a resin that becomes a phenoxy resin after the reaction.

  Further, a thermosetting resin may be blended with the thermoplastic epoxy resin without departing from the object of the present invention.

  In addition, when the resin used for the screw-shaped molded body is composed only of a thermosetting resin, it cannot be molded by heating when molding the threaded part etc. It becomes. For this reason, not only is the production complicated, but the carbon fibers are cut, and the strength of the obtained thread-like molded product becomes insufficient. In addition, when a liquid or paste-like fiber reinforced resin material in which a thermosetting resin is added to a reinforcing fiber is stored without being cured and molded into a screw-shaped molded body at any time, the thermosetting resin is cured. In the meantime, it is necessary to store the fiber reinforced resin material in a frozen or refrigerated state, which increases the storage burden.

<Three-dimensional fiber structure>
Next, the three-dimensional fiber structure of reinforcing fibers used for the thread-shaped molded body in the present embodiment will be described.

  The three-dimensional fiber structure of reinforcing fibers in the present embodiment refers to a plurality of bundles of reinforcing fibers twisted or knitted, assembled, or a string-like braid or knitted fabric. The three-dimensional fiber structure is preferably a braided braid, knitted fabric or the like, and the center portion is not hollow, that is, the structure is not solid but solid. As an example, all the bundles of reinforcing fibers are oriented in the oblique direction, and the three-dimensional braided structure knitted into a three-dimensional shape while the bundles of reinforcing fibers are entangled or all the orientation directions of the yarn bundles are oblique. Examples include a three-dimensional braided structure in which a bundle of reinforcing fibers having an oblique component and a bundle of reinforcing fibers oriented in the braiding axis direction are mixed, as well as a yarn bundle having a direction. In addition, in JP-A-1-259932, JP-A-62-250258, and U.S. Pat. No. 4,312,261, the shape and manufacturing method for a three-dimensional fiber structure are described. The three-dimensional fiber structure disclosed in these documents can be used as appropriate.

  Moreover, although a cylindrical three-dimensional fiber structure may be used, in this case, another reinforcing fiber or a reinforcing fiber composite material may be disposed in the cylindrical portion. Thereby, even if it is a cylindrical three-dimensional fiber structure, the reinforced fiber which has high intensity | strength can be obtained.

  About a cylindrical three-dimensional fiber structure, the three-dimensional fiber structure which consists of a cylindrical braid can be manufactured by utilizing a string making machine using a bundle of a plurality of reinforcing fibers. Further, a three-dimensional fiber structure composed of a tubular knitted string can be manufactured by using a circular knitting machine or the like using a bundle of one or a plurality of reinforcing fibers. Further, at the time of such stringing or knitting, another reinforcing fiber or a reinforcing fiber composite material may be used as a core, and the surroundings may be assembled or knitted with a bundle of reinforcing fibers, or a tubular braid or knitted fabric After that, another reinforcing fiber or a reinforcing fiber composite material may be inserted into the cylindrical hollow portion.

  In addition, the shape of the cross section perpendicular to the length direction of the three-dimensional fiber structure in the present embodiment is, for example, a polygon such as a round cross section, an elliptical cross section, a triangular cross section, a quadrangular cross section, a pentagonal cross section, or a hexagonal cross section. There is no particular limitation.

  Moreover, what is necessary is just to set arbitrarily about the diameter (thickness) of the said cross section of a three-dimensional fiber structure according to the magnitude | size of the target screw-shaped molded object. Further, the length of the three-dimensional fiber structure is not particularly limited. When the screw-shaped molded body obtained using the three-dimensional fiber structure is a bolt, the length of the three-dimensional fiber structure is approximately the same as the length of the bolt from the viewpoint of tensile strength. preferable.

<Fiber-reinforced resin material A>
Next, the fiber reinforced resin material which comprises the screw-shaped molded object in this Embodiment is demonstrated.

  The fiber reinforced resin material in the present embodiment is made of thermoplastic epoxy resin up to the inside of the three-dimensional fiber structure of the above-mentioned reinforcing fiber and into the bundle of reinforcing fibers constituting the above-mentioned three-dimensional fiber structure. It was obtained by impregnation. In this case, it is preferable that the thermoplastic epoxy resin is impregnated between the individual fibers constituting the bundle of reinforcing fibers.

  The shape of the fiber reinforced resin material is rod-like, and the shape of the cross section perpendicular to the length direction is, for example, a polygon such as a round cross section, an elliptical cross section, a triangular cross section, a square cross section, a pentagonal cross section, or a hexagonal cross section. It is not particularly limited.

  Moreover, what is necessary is just to set arbitrarily about the diameter (thickness) of the said cross section of a fiber reinforced resin material according to the magnitude | size of the target screw-shaped molded object. The length of the fiber reinforced resin material is not particularly limited. When the screw-like molded body obtained using the fiber reinforced resin material is a bolt, the length of the fiber reinforced resin material is preferably approximately the same as the length of the bolt from the viewpoint of tensile strength. Further, when the length of the fiber reinforced resin material and the length of the bolt are approximately the same, the length of the reinforced fiber and the bundle of reinforced fibers constituting the fiber reinforced resin material compared to the length of the fiber reinforced resin material. The length of becomes longer.

<Manufacturing method of screw-shaped molded product>
Next, an example of the manufacturing method of the screw-shaped molded object which concerns on this Embodiment is demonstrated. In addition, the manufacturing method of the screw-shaped molded object which concerns on this Embodiment is not limited to the following method.

  When manufacturing the thread-shaped molded body according to the present embodiment, first, a three-dimensional fiber structure of reinforcing fibers is prepared. The method for producing the three-dimensional fiber structure is as described above.

  Next, a thermoplastic epoxy resin is applied to the three-dimensional fiber structure, so that the three-dimensional fiber structure is impregnated with the thermoplastic epoxy resin. Specifically, a thermoplastic epoxy resin solution is used to impregnate a three-dimensional fiber structure with a thermoplastic epoxy resin.

  The thermoplastic epoxy resin solution preferably contains at least a reactive thermoplastic epoxy resin, a solvent for dissolving or dispersing the thermoplastic epoxy resin, and a curing agent. The thermoplastic epoxy resin solution is not limited to a solution in which a solute is completely dissolved in a solvent, but may be an emulsion or a dispersion.

  Solvents contained in the thermoplastic epoxy resin solution include water, dimethylformamide, toluene, xylene, cyclohexane, methyl acetate, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methanol, ethanol, butanol Isopropyl alcohol, methyl cellosolve, cellosolve, or anone.

  The curing agent contained in the thermoplastic epoxy resin solution includes amine compounds such as aliphatic polyamines, polyaminoamides, ketimines, aliphatic diamines, aromatic diamines, imidazoles, and tertiary amines, phosphoric acid compounds, and acid anhydrides. Compounds, mercaptan compounds, phenol resins, amino resins, dicyandiamide, Lewis acid complex compounds, and the like.

  In addition, the thermoplastic epoxy resin solution includes additives such as a catalyst, a polymerization initiator, a polymerization accelerator, an antioxidant, an ultraviolet absorber, a pigment, a thickener, an emulsifier, and a dispersant. You may add in the range which does not deviate from the objective.

  In the present embodiment, the viscosity of the thermoplastic epoxy resin solution is preferably 5 to 1000 mPa · s. If the viscosity of the thermoplastic epoxy resin solution is 5 mPa · s or more, a sufficient amount of thermoplastic epoxy resin can be easily imparted to the three-dimensional fiber structure. In addition, the viscosity of the thermoplastic epoxy resin solution is preferably 10 mPa · s or more, more preferably 50 mPa · s or more, from the viewpoint of the amount of thermoplastic epoxy resin applied to the three-dimensional fiber structure. Further, if the viscosity of the thermoplastic epoxy resin solution is 1000 mP · s or less, the thermoplastic epoxy resin can easily penetrate into the bundle of reinforcing fibers (for example, carbon fibers) constituting the three-dimensional fiber structure. it can. The viscosity of the thermoplastic epoxy resin solution is more preferably 500 mPa · s or less, and further preferably 200 mPa · s or less.

  The three-dimensional fiber structure thermoplastic epoxy resin can be applied by a dip method in which the three-dimensional fiber structure is immersed in a thermoplastic epoxy resin solution, a dip nip method in which the thermoplastic epoxy resin solution is squeezed with a mangle after immersion, or a thermoplastic epoxy resin solution. A transfer method in which a thermoplastic epoxy resin is transferred from a kiss roll or the like to a three-dimensional fiber structure by being attached to a kiss roll or gravure roll, or a spray method in which a mist-like thermoplastic epoxy resin solution is applied to a bundle of reinforcing fibers Is mentioned. Also, in the dip method, transfer method, spray method, etc., the three-dimensional fiber structure to which the thermoplastic epoxy resin solution is adhered is brought into contact with a die, a roll or the like to bring the three-dimensional fiber structure and the carbon fiber bundle inside. The amount of the thermoplastic epoxy resin applied to the three-dimensional fiber structure can be adjusted by pushing the thermoplastic epoxy resin up to or removing excess thermoplastic epoxy resin.

  In addition, the amount of the thermoplastic epoxy resin solution applied to the three-dimensional fiber structure is adjusted so that the thread-shaped molded body has the above-mentioned preferable Vf value, or the heat in the thermoplastic epoxy resin solution is adjusted by the blending ratio of the solvent. It is good to adjust the application amount of the plastic epoxy resin.

  In the present embodiment, a bundle of carbon fibers is used as the reinforcing fiber constituting the three-dimensional fiber structure, and a thermoplastic epoxy resin solution having a relatively low viscosity is used. The thermoplastic epoxy resin can be infiltrated deeply.

  After applying the thermoplastic epoxy resin to the three-dimensional fiber structure, drying and / or heat treatment may be performed. Drying and heat treatment may be performed simultaneously or separately. In the stage of obtaining the fiber reinforced resin material, the thermoplastic epoxy resin may be completely reacted to complete the fiber reinforced resin material, but the reaction of the thermoplastic epoxy resin has stopped (or reacted) to some extent. In this state, the thermoplastic epoxy resin may be completely reacted when forming into a screw-shaped molded body or after molding.

  The temperature at which the thermoplastic epoxy resin applied to the three-dimensional fiber structure is dried or the temperature at which the heat treatment is performed depends on the thermoplastic epoxy resin, the curing agent, or the solvent. The heat treatment is preferably performed for about 1 minute to about 1 hour. More preferably, the drying is performed at 50 to 100 ° C. for 10 to 30 minutes, and the heat treatment is performed at 120 to 180 ° C. for 3 to 40 minutes. Such a range of conditions is preferable from the viewpoint of the quality and productivity of the fiber-reinforced resin material obtained.

  In this manner, a rod-like fiber reinforced resin material obtained by impregnating a thermoplastic epoxy resin into a string-like three-dimensional fiber structure can be obtained.

  Next, the fiber-reinforced resin material is heated and / or pressurized using a die having a shape such as a screw or bolt to be manufactured, thereby forming a screw-like molded body having a screw shape. Then, after cooling, it is taken out from the mold (mold), and unnecessary portions are cut. If burrs or the like are generated, the burrs or the like are removed to obtain screws or bolts to be manufactured.

  Examples of the method for heating and pressurizing the fiber reinforced resin material include a mold pressing method, an autoclave method, and a heating / cold pressing method. Further, these methods and the insert molding method may be combined.

  The temperature at the time of heating a fiber reinforced resin material is about 150-400 degreeC, for example. Moreover, the pressure at the time of pressurization of a fiber reinforced resin material is about 1-500 Mpa, for example, and pressurization time is about 1 minute-24 hours, for example. In addition, when pressurizing a fiber reinforced resin material, it is good to pressurize in a vacuum state. Further, preliminary heating may be performed before heating and / or pressurization.

  Further, two plate-shaped molds each having a screw shape formed on at least one of them are heated, and a bar-shaped fiber reinforced resin material is sandwiched between the two plate-shaped molds and pressed, and two sheets of the mold are pressed. By rolling the rod-shaped fiber reinforced resin material while shifting the relative position of the plate-shaped mold, it is possible to form a screw shape formed in the mold over the entire surface of the rod-shaped fiber reinforced resin material. From the viewpoint of productivity, it is preferable to use such a manufacturing method.

  In addition, before forming the fiber reinforced resin material with a mold having a shape such as a screw or bolt, the purpose is to heat and / or press the fiber reinforced resin material once so that the screw thread portion can be accurately formed. It may be preformed into a cylindrical shape or the like that is close to the size of the screw or the like to be manufactured. Further, preliminary heating may be performed before heating and / or pressurization.

  In addition, the three-dimensional fiber structure is molded into a screw-shaped molded body by simultaneously applying pressure using a mold in which a screw shape is formed during heat treatment immediately after applying the thermoplastic epoxy resin solution to the three-dimensional fiber structure. Also good.

  The thread-shaped molded body in the present embodiment is excellent in strength such as tensile strength, and is excellent in form stability and durability even in an environment where a wet state and a dry state are repeated. As a result, it is changed to metal screws used for various structures such as large buildings such as houses and bridges, transport equipment such as automobiles, trains, linear motor cars, airplanes, and manufacturing equipment such as machine tools. Thus, it is possible to use the thread-shaped molded body in the present embodiment.

  In addition, when using a screw-shaped molded body in a place where vibration is intense, such as in a transport machine, the screw-shaped molded body is heated after joining the members using the screw-shaped molded body, and the thermoplastic epoxy resin is heated. By tightening and fusing bolts and nuts by softening and melting, the occurrence of loosening of the thread-shaped molded body is suppressed even in places where the vibration is severe and the thread-shaped molded body tends to loosen. be able to.

(Embodiment 2)
Next, the screw-shaped molded body according to Embodiment 2 will be described.

  The thread-shaped molded body according to the present embodiment is formed by laminating a strip-shaped fiber reinforced resin material impregnated with a thermoplastic epoxy resin into a bundle of reinforcing fibers. In this case, the bundle of reinforcing fibers constituting the fiber reinforced resin material may be randomly stacked three-dimensionally, or one direction or a plurality of directions such as the length direction, the width direction, or the circumferential direction of the thread-shaped molded body. The direction may be laminated with directionality, or may be laminated in a state in which a three-dimensional random state and a state with directionality are combined.

  Further, the screw-like molded body according to the present embodiment has a thread portion (groove portion) having a thread (groove) on the surface, similarly to the screw-like molded body according to the first embodiment. The thread portion includes a thermoplastic epoxy resin, and preferably the thread portion includes a reinforcing fiber and a thermoplastic epoxy resin.

  The reinforcing fiber present in the thread portion is a reinforcing fiber contained in the strip-like fiber reinforced resin material (the reinforcing fiber exists across the thread portion and the main body portion). As described above, the reinforcing fibers present in the screw thread portion constitute a bundle of strip-like reinforcing fibers, and in a preferred embodiment, the bundle of reinforcing fibers constituting the strip-like fiber reinforced resin material is formed into a screw shape. Since the reinforcing fibers of the main body such as screws and the reinforcing fibers of the screw thread portion are combined while being entangled randomly in the body in three dimensions, the screw thread portion has excellent toughness. Since it is also excellent in the shear strength, it is possible to obtain a thread-shaped molded body having excellent tensile strength.

  Further, as in the first embodiment, since the thermoplastic epoxy resin is used for the fiber reinforced resin material constituting the screw-shaped molded body, the screw is used even in an environment where the wet state and the dry state are repeated. It can suppress that a shape molded object deform | transforms. Thereby, even if it joins a member using a screw-shaped molded object, it can suppress that a screw-shaped molded object loosens. Moreover, the thread-shaped molded object excellent in durability and intensity | strength can be obtained.

  Also, by using a thermoplastic epoxy resin for the fiber reinforced resin material used in the thread-shaped molded body, the fiber reinforced resin material can be heated and pressurized when forming a screw shape such as a threaded portion. Thus, a screw shape can be easily formed.

  Moreover, since the thermoplastic epoxy resin is impregnated into the bundle of reinforcing fibers of the fiber reinforced resin material, the reinforcing fiber is also included in the thread portion together with the thermoplastic epoxy resin when the fiber reinforced resin material is heated and / or pressurized. It becomes easy to move.

  Moreover, since the thermoplastic epoxy resin has entered the bundle of reinforcing fibers existing in the thread portion of the thread-shaped molded body and the central portion of the main body portion, the thermoplastic epoxy is heated during the heating / pressing of the fiber reinforced resin material. Reinforcing fibers can easily move to the threaded portion together with the resin, and the strength of the thread-shaped molded body itself is excellent.

  The fiber volume fraction (Vf value) of such a screw-shaped molded body is preferably 20 to 80%. Preferably, the fiber volume ratio of the thread-shaped molded body is 40% to 70%, more preferably 50 to 60%. If the fiber volume fraction of the thread-shaped molded body is lower than the lower limit (for example, 20%), the thread portion may be made of only a thermoplastic epoxy resin, and the tensile strength of the obtained thread-shaped molded body may be decreased. is there. In addition, if the fiber volume ratio of the thread-shaped molded body exceeds the upper limit (for example, 80%), when the thread portion is formed, the reinforcing fiber of the thread portion may be cut. There exists a possibility that the tensile strength of the obtained thread-shaped molded object may fall.

  The thread-shaped molded body in the present embodiment is also excellent in tensile strength as in the first embodiment. In the thread-shaped molded body formed by a press method using a mold, the tensile strength is 150 MPa or more. More preferably, it is 200 MPa or more. Moreover, in the screw-shaped molded body manufactured by the injection molding method or the transfer molding method, the tensile strength is preferably 80 Mpa or more, and more preferably 100 MPa or more. In order to improve the tensile strength of the thread-like molded body manufactured by the injection molding method or the transfer molding method, an insert molding method may be combined. For example, among the three-dimensional fiber structure (solid or tubular) of the first embodiment, the fiber reinforced resin material A, or the strip-shaped fiber reinforced resin material according to the present embodiment, it is thinner than the width of the mold. A fiber-reinforced resin material such as a linear or rod-like material that is almost the same as the mold length (at least longer than the length of the reinforced fiber contained in the thermoplastic resin injected by the injection molding method or transfer molding method) A method of injecting a resin for injection molding or transfer molding into the mold after arranging the fiber axis direction of this in the mold in accordance with the length direction of the thread-shaped molded body. In the insert molding method, when a cylindrical three-dimensional fiber structure is arranged in a mold, a resin for injection molding or transfer molding may be injected into the cylinder. Moreover, when using a screw-shaped molded object as a wood screw, the tensile strength of a screw-shaped molded object should just be 80 Mpa or more. In addition, although the upper limit of the tensile strength of a screw-shaped molded object should just be determined by a use, it is about 500 MPa, for example. Moreover, when manufacturing a screw-shaped molded object combining with an insert molding method, the upper limit of the tensile strength of a screw-shaped molded object is about 1000 MPa.

  Moreover, when using a screw-shaped molded object for a wood screw etc. similarly to the said Embodiment 1, the thread part of a screw-shaped molded object may be comprised only with the thermoplastic epoxy resin without including a reinforced fiber. .

  Note that the thread height, the thread pitch, the length, and the thickness of the thread portion of the thread-shaped formed body can be arbitrarily set according to the intended use and strength. .

<Strip-shaped fiber-reinforced resin material>
Here, the strip-shaped fiber reinforced resin material used when producing the screw-shaped molded body in the present embodiment will be described.

  The strip-like fiber-reinforced resin material in the present embodiment is obtained by impregnating a bundle of reinforcing fibers arranged in one direction with a thermoplastic epoxy resin. Specifically, the thermoplastic epoxy resin is impregnated even inside the bundle of reinforcing fibers.

  The shape of the strip-like fiber-reinforced resin material is not limited to the shape of a long rectangular and flaky strip, but is long in one direction (becomes the length direction) and in another direction different from the one direction ( (Longitudinal direction and width direction) includes a short length (bar shape), and is not limited to such a long shape, and the length in the length direction and the length in the width direction and / or the thickness direction. Includes those having the same shape, and further including those having such shapes and partially different thicknesses. As an example, the shape of the strip-like fiber reinforced resin material is a so-called strip shape, columnar shape, prismatic shape, chip shape, wire shape, needle shape, or cushion shape, but is not limited thereto.

  Further, the length of the strip-like fiber reinforced resin material and the length of the reinforced fiber contained in the fiber reinforced resin material may be substantially the same.

  The upper limit of the length of the strip-like fiber-reinforced resin material and the reinforcing fiber is almost determined by the size of the manufactured screw-like molded body, but as an example, it is about 1 mm or more and about 500 mm or less. The lengths of the strip-like fiber reinforced resin material and the reinforcing fibers are preferably 5 mm or more, and more preferably 10 mm or more. When the length of the fiber reinforced resin material and the reinforcing fiber is less than 1 mm, the reinforcing fiber included in the thread portion of the screw-shaped molded body cannot be entangled with the reinforcing fiber present in the main body portion of the screw-shaped molded body. In addition, the strength of the thread portion of the obtained thread-shaped molded body may be reduced.

<Fiber-reinforced resin material B>
Next, the fiber reinforced resin material which comprises the screw-shaped molded object in this Embodiment is demonstrated.

  The fiber-reinforced resin material in the present embodiment is formed by laminating the above-described strip-shaped fiber-reinforced resin material. In this case, the bundle of reinforcing fibers constituting the strip-shaped fiber reinforced resin material may be randomly stacked in three dimensions, or one of the lengthwise direction, the width direction, the circumferential direction, and the like of the screw-shaped molded body. It may be laminated with directionality in a direction or a plurality of directions, or may be laminated in a state where a three-dimensional random state and a state with directionality are combined.

  The bundle of reinforcing fibers constituting the strip-shaped fiber reinforced resin material is randomly laminated in three dimensions. The bundle of strip-shaped reinforcing fibers obtained by arranging a plurality of reinforcing fibers in one direction. Is a state in which the fiber axis direction of each bundle is randomly arranged and the bundle of the plurality of reinforcing fibers is laminated so as to overlap, more specifically, a plurality of strip-shaped reinforcements The bundle of fibers is partially overlapped so that the fiber axis directions of the bundles are random on each side of each bundle (for convenience, the side surface of the fiber-reinforced resin material is also referred to as a side). Each bundle is in a state in which the bundles are stacked at an angle with respect to the length direction of the thread-shaped molded body at least slightly in a slanted manner and folded on each other.

  In this way, bundles of reinforcing fibers initially arranged in one direction included in the strip-like fiber reinforced resin material randomly laminated in three dimensions and the reinforcing fibers constituting the same are bent, meandering, and spreading. It may be. In particular, in a screw-shaped molded body formed by heating and / or pressurization, the shape of the molded body is such that the concavo-convex shape of the molded body, the reinforcing fibers themselves or the bundle of reinforcing fibers bend or meander due to the entanglement of the bundles. There are many things. In addition, the concept of a bundle of strip-like fiber reinforced resin material randomly stacked in three dimensions is such that the reinforcing fiber or the bundle of reinforcing fibers is bent, meandered, or spread by pressurization or the like. Also included is a deformed state.

  Further, the fact that strip-like fiber reinforced resin materials are laminated with directionality in the length direction, width direction, circumferential direction, etc. is obtained by arranging a plurality of reinforcing fibers in one direction. A plurality of strip-shaped reinforcing fiber bundles, the fiber axis directions of the reinforcing fibers constituting the bundle are laminated in the same direction, and the fiber axis direction is the length direction of the obtained screw-shaped molded body, The one in a specific direction such as the width direction or the circumferential direction.

  For example, if it is long in one direction, such as a wood screw or a chopping bolt, the length direction of the wood screw or chopping bolt and a strip-like fiber reinforced resin material are formed (a bundle of strip-like reinforcement fibers If the arrangement is made to match the axial direction of the reinforcing fibers, the obtained wood screws and sizing bolts have improved tensile strength (particularly, tensile strength of the main body) in the length direction. In this case, the length of the reinforcing fiber is preferably substantially the same as the length of the wood screw or the dimension bolt from the viewpoint of improving the tensile strength. In addition, when using a strip-like fiber reinforced resin material shorter than the length of the wood screw or cutting bolt, from the viewpoint of improving the tensile strength of the main body, while aligning the fiber axis direction of the reinforcing fiber, It is preferable to arrange the bundles of reinforcing fibers so as to partially overlap each other.

  In addition, the length direction of a long one in a direction such as a wood screw or a cutting bolt intersects with the axial direction of the reinforcing fiber constituting the strip-like fiber reinforced resin material (constituting a bundle of strip-like reinforcing fibers). If it arrange | positions in this way, although the tensile strength of the main-body part will fall, the tensile strength of the thread part obtained as for a wood screw and a dimension cutting bolt will improve.

  Moreover, if it is hollow screw-shaped molded objects, such as a nut, the fiber of the reinforced fiber which comprises a strip-shaped fiber reinforced resin material along the circumferential direction (forms the bundle of strip-shaped reinforced fiber). If the axial directions are aligned, and more preferably, the reinforcing fibers are arranged so as to partially overlap in the fiber axial direction, the resulting nut has improved strength against cracking of the nut.

  In addition, the combination of a plurality of directions with directionality means that, for example, if it is long in one direction, such as a wood screw or a cutting bolt, the wood screw or cutting bolt The length direction and the axial direction of the reinforcing fibers constituting the strip-like fiber reinforced resin material (constituting a bundle of strip-like reinforcing fibers) are arranged together and the length direction and the strip-like fiber reinforced resin are arranged. Examples thereof include those arranged so as to intersect with the axial direction of the reinforcing fibers constituting the material (constituting a bundle of strip-like reinforcing fibers). By setting it as such a structure, the intensity | strength of the several direction and specific part of a molded object to be obtained can be improved.

  In addition, a stack of strip-like fiber reinforced resin materials is randomly stacked in three dimensions, such as a combination of a random state in three dimensions and a state having directionality. A state and a state of being laminated with a direction in a length direction, a width direction, a circumferential direction, etc., and a state of being laminated by combining a state with a direction in a plurality of directions, It is a mixture of screw-shaped molded products. By adopting such a configuration, the overall strength is excellent, and the strength of a specific portion can be reinforced.

  The thermoplastic epoxy resin and the reinforcing fiber used in the present embodiment are the same as the thermoplastic epoxy resin and the reinforcing fiber used in the first embodiment.

<Manufacturing method of screw-shaped molded product>
Next, an example of the manufacturing method of the screw-shaped molded object which concerns on this Embodiment is demonstrated. In addition, the manufacturing method of the screw-shaped molded object which concerns on this Embodiment is not limited to the following method.

  When manufacturing the thread-shaped molded body according to the present embodiment, first, a strip-shaped fiber-reinforced resin material is prepared.

  The strip-like fiber reinforced resin material can be produced as follows. Specifically, a thermoplastic epoxy resin is applied to a bundle of reinforcing fibers using a thermoplastic epoxy resin solution so that the bundle of reinforcing fibers is impregnated with the thermoplastic epoxy resin, and the obtained fiber reinforced resin material is arbitrarily added. A strip-like fiber-reinforced resin material can be obtained by cutting the length. The thermoplastic epoxy resin solution, the method for applying the thermoplastic epoxy resin solution, and the like are the same as those in the first embodiment.

  Next, a strip-shaped fiber reinforced resin material is laminated at random on a die having a shape such as a screw or bolt to be manufactured, and heated and / or pressurized to form a screw-like molded body having a screw shape. Thereafter, after cooling, the product is removed from the mold, and unnecessary portions are cut. If burrs or the like are generated, the burrs or the like are removed to obtain screws or bolts to be manufactured. Moreover, you may pre-heat before heating and / or pressurizing.

  In addition, before the strip-shaped fiber reinforced resin material is formed with a mold having a shape such as a screw or a bolt, the fiber reinforced resin material is heated and / or pressurized once so that the screw thread portion can be accurately formed. Then, it may be preformed into a cylindrical shape or the like. Moreover, you may pre-heat before heating and / or pressurizing.

  As a method for heating and pressurizing the strip-shaped fiber reinforced resin material, as in the first embodiment, a die pressing method, an autoclave method, a heating / cold pressing method, and the like can be given.

  The temperature at the time of heating a fiber reinforced resin material is about 150-400 degreeC, for example. Moreover, the pressure at the time of pressurization of a fiber reinforced resin material is about 1-500 Mpa, for example, and pressurization time is about 1 minute-24 hours, for example. In addition, when pressurizing a fiber reinforced resin material, it is good to pressurize in a vacuum state.

  Further, by sandwiching a fiber reinforced resin material formed in a strip shape between two heated plate-shaped screw-shaped dies, and shifting the relative position of the two plate-shaped dies while applying pressure, It is also possible to form a screw shape on the surface of the fiber reinforced resin material formed in the mold. In this case, it is preferable to use a strip-shaped fiber reinforced resin material preformed in a columnar shape or the like.

  Further, instead of heating and pressurizing the strip-like fiber reinforced resin material, as another manufacturing method, a screw-shaped molded body may be molded by combining an injection molding method, a transfer molding method, or an insert molding method with these. . When using an injection molding method, etc., a strip-like fiber reinforced resin material is put into an injection molding machine, etc., heated to melt the strip-like fiber reinforced resin material, injected into a mold, etc. A molded body can be produced. In the case of producing a thread-shaped molded body using an injection molding method, the Vf value of the thread-shaped molded body is preferably 10% to 60%, more preferably 20% to 50%. In the case of producing a thread-shaped molded body using the transfer molding method, the Vf value of the thread-shaped molded body is preferably 10% to 80%, more preferably 30% to 70%.

  When the Vf value of the thread-shaped molded body is smaller than the lower limit value (for example, 10%), the strength of the obtained thread-shaped molded body is decreased. On the other hand, when the Vf value of the thread-shaped molded body exceeds the above upper limit value (for example, 60%), the reinforced fibers contained in the strip-shaped fiber-reinforced resin material put into the injection molding machine are cut and the thread-shaped molding obtained is obtained. The strength of the body may be reduced. In a transfer molding machine, if the upper limit (for example, 80%) is exceeded, clogging may occur in the transfer molding machine.

  When the injection molding method is used, the length of the strip-like fiber-reinforced resin material (bundle of reinforcing fibers) is preferably more than 1 mm and not more than 20 mm, more preferably not less than 3 mm and not more than 15 mm. When the length of the strip-like fiber reinforced resin material (bundle of reinforcing fibers) is shorter than the lower limit (for example, 1 mm), the strength of the obtained thread-shaped molded body may be reduced. On the other hand, when the length of the strip-shaped fiber reinforced resin material (bundle of reinforced fibers) exceeds the upper limit (for example, 20 mm), clogging occurs in the injection molding machine, or the strip-shaped fiber reinforced resin material. There is a possibility that the reinforcing fiber contained in the is cut in the injection molding machine.

  When the transfer molding method is used, the length of the strip-shaped fiber reinforced resin material (bundle of reinforcing fibers) is not particularly limited, and a longer one than the injection molding method can be used. Depending on the size of the plunger of the transfer molding apparatus, the upper limit of the length of the strip-like fiber reinforced resin material (bundle of reinforcing fibers) may be 100 mm, 200 mm, or more. The lower limit of the length of the strip-like fiber reinforced resin material (bundle of reinforcing fibers) is the same as that of the injection molding method.

  By using the strip-like fiber reinforced resin material according to the present embodiment, not only bolts and screws, but also screw-like molded bodies such as nuts and turnbuckles whose screw threads do not face the outside are manufactured. Is possible.

  As mentioned above, although the screw-shaped molded object which concerns on this invention was demonstrated based on Embodiment 1, 2, this invention is not limited to Embodiment 1,2.

  For example, the surface of the rod-like (preferably columnar) three-dimensional fiber structure of the first embodiment or the rod-shaped (preferably columnar) molded with the fiber-reinforced resin material of the strip-like shape of the second embodiment. A surface of which a thread portion is formed of a thermoplastic epoxy resin may be used.

  In addition, it is realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, and forms obtained by making various modifications conceived by those skilled in the art to each of the above embodiments. Forms to be made are also included in the present invention.

  Hereinafter, although the specific Example of the screw-shaped molded object which concerns on this invention is described, this invention is not limited to these Examples. In the following examples, “parts” represents parts by mass.

  In addition, the various physical-property values in each evaluation item of A and B in a following example and a comparative example were performed with the following method.

[A: Tensile strength]
About the obtained thread-shaped molded object, the maximum test force (tensile strength) was measured by measuring according to JISZ2241. The tensile strength of the bolt was measured by attaching the bolt to an SS400 nut. Moreover, the wood screw screwed the wood screw into the piece of wood, and measured the tensile strength.

  In this example, the tensile strength (MPa: stress) was determined by dividing the measured value by the cross-sectional area of the outer diameter of the sample.

[B: Vf value]
The Vf value of the obtained thread-shaped molded body was obtained by the following formula 1.

Vf value (%) = (W−ρ ₃ × V) / [(ρ ₂ −ρ ₃ ) × V] × 100 Equation 1

In Equation 1, W is the mass (g) of the thread-shaped molded body, V is the volume (cm ³ ) of the thread-shaped molded body, ρ ₂ is the density of reinforcing fibers in the thread-shaped molded body (g / cm ³ ), ρ ₃ represents the density (g / cm ³ ) of the resin used for the thread-shaped molded body.

Example 1
In Example 1, a bundle of 24,000 carbon fibers (bundle of carbon fibers 24K) was used as a bundle of reinforcing fibers (PAN-based carbon fiber (Torayca (registered trademark) T700SC manufactured by Toray Industries, Inc.)). ).

  First, 110 carbon fiber bundles were installed in a stringing machine, and solid fibers were knitted into a three-dimensional shape while the bundles of reinforcing fibers were entangled with all the reinforcing fiber bundles oriented obliquely. A three-dimensional fiber structure was manufactured.

  Next, the following reactive thermoplastic epoxy resin solution was applied to the three-dimensional fiber structure by dipping.

[Thermoplastic epoxy resin solution (viscosity: 80 mPa · s)]
-Thermoplastic epoxy resin (DENATEITE XNR6850V, solid content 85 mass%, manufactured by Nagase ChemteX Corporation) 100 parts-Curing agent (DENATEITE XNH6850V, solid content 30 mass%, manufactured by Nagase ChemteX Corporation) 6.5 parts-Methyl ethyl ketone (MEK) 10 copies

  Subsequently, the three-dimensional fiber structure to which the thermoplastic epoxy resin solution is applied is passed through a die to adjust the shape, dried at 60 ° C. for 20 minutes, and then further heat-treated at 150 ° C. for 20 minutes while passing through the die. The reaction type thermoplastic epoxy resin is reacted to form a polymer, and the three-dimensional fiber structure is provided with the reaction type thermoplastic epoxy resin, and a substantially circular rod-like fiber reinforced resin material having a cross-sectional shape of about 15 mm in diameter. A was obtained. The glass transition point of the thermoplastic epoxy resin was 100 ° C. The Vf value of the obtained fiber reinforced resin material A was 50%.

  When the cut surface of the rod-like fiber reinforced resin material A cut was observed at 100 times using an electron microscope, the thermoplastic epoxy resin had entered the center of the bundle of carbon fibers.

  The viscosity of the thermoplastic epoxy resin solution used in this example was measured using a B-type viscometer (TVB-15 type viscometer: manufactured by Toki Sangyo Co., Ltd.). Measured at 20, 12 rpm and room temperature.

  Next, the rod-like fiber reinforced resin material A was put into a M12 screw mold and heated and pressurized at 200 ° C. and 20 MPa for 5 minutes using a vacuum press.

  Then, the screw-shaped molded object (bolt) was obtained by removing the thermoplastic epoxy resin which oozed out from the mold form.

  The appearance quality of the thread-shaped molded body thus obtained was good, and when the cross section of the thread-shaped molded body was observed at a magnification of 100 using an electron microscope, carbon fibers were present in the thread portion. In addition, it was found that the space inside the thread-shaped molded body was not confirmed and was filled with a thermoplastic epoxy resin. Further, the Vf value of the obtained thread-shaped molded body was 50%. Moreover, it was 400 MPa when the tensile strength of the obtained thread-shaped molded object was measured.

(Example 2)
In Example 2, as a bundle of reinforcing fibers, a bundle of 60,000 carbon fibers arranged in one direction (60K) was used (PAN-based carbon fiber: Pyrofil (registered trademark) manufactured by Mitsubishi Chemical Corporation). TRH50 60M).

  While pulling out the carbon fiber bundle as it was from the drum around which the carbon fiber bundle was wound, the following thermoplastic epoxy resin solution was applied to one side of the carbon fiber bundle using a kiss roll. In addition, the cross-sectional shape of the bundle of carbon fibers when pulled out from the drum was a flat shape.

[Thermoplastic epoxy resin solution (viscosity: 15 mPa · s or less (measurement limit value of the apparatus or less))]
-Thermoplastic epoxy resin (Reactive resin: DENATEITE XNR6850V: manufactured by Nagase ChemteX Corporation) 100 parts-Curing agent (DENATEITE XNH6850V: manufactured by Nagase ChemteX Corporation)
6.5 parts ・ Methyl ethyl ketone (MEK) 50 parts

  Next, the bundle of carbon fibers to which the thermoplastic epoxy resin solution was applied was brought into contact with four rolls (the upper and lower surfaces of the bundle of carbon fibers were alternately contacted twice, respectively), thereby squeezing the bundle of carbon fibers. After that, it is passed through a die, dried at 60 ° C. for 20 minutes, and subsequently subjected to heat treatment at 150 ° C. for 20 minutes to react with a reactive thermoplastic epoxy resin to form a polymer, and the reinforced fibers arranged in one direction A flat and long fiber-reinforced resin material having a cross-sectional shape of about 5 mm in width, in which a reactive thermoplastic epoxy resin was applied to the bundle, was obtained. The glass transition point of the thermoplastic epoxy resin was 100 ° C.

  Next, the obtained long fiber reinforced resin material is cut so as to have a length of 40 to 50 mm substantially perpendicular to the axial direction of the carbon fiber to obtain a strip-like fiber reinforced resin material having a flat cross section. It was. The Vf value of the fiber reinforced resin material thus obtained was 50%. In addition, since the used carbon fiber is a long fiber, the length of the carbon fiber in the obtained fiber reinforced resin material is the same as the length of a fiber reinforced resin material, and is 40-50 mm.

  When the cut surface of the strip-shaped fiber reinforced resin material was observed at 100 times using an electron microscope, it was found that the thermoplastic epoxy resin had entered the center of the bundle of carbon fibers.

  The viscosity of the thermoplastic epoxy resin solution used in this example was measured using a B-type viscometer (TVB-15 type viscometer: manufactured by Toki Sangyo Co., Ltd.). Measured at 20, 12 rpm and room temperature.

  Next, a plurality of the obtained strip-shaped fiber reinforced resin materials are randomly stacked in the M12 screw mold while the length direction of the fiber reinforced resin material is oriented in the screw length direction. Using a vacuum press, heating and pressurization were performed at 200 ° C. and 20 MPa for 5 minutes.

  Thereafter, the thermoplastic epoxy resin that exudes from the mold form was removed, and strip-shaped fiber reinforced resin materials (bundles of carbon fibers) were laminated (the fiber axis direction of each carbon fiber bundle was a screw. A screw-like molded body (bolt) that was slightly tilted and meandered while being roughly oriented with respect to the length direction of the shaped molded body, and was mutually folded.

  The appearance quality of the thread-shaped molded body thus obtained was good, and when the cross section of the thread-shaped molded body was observed at a magnification of 100 using an electron microscope, carbon fibers were present in the thread portion. In addition, it was found that the space inside the thread-shaped molded body was not confirmed and was filled with a thermoplastic epoxy resin. Further, the Vf value of the obtained thread-shaped molded body was 55%. Moreover, it was 200 Mpa when the tensile strength of the obtained screw-shaped molded object was measured.

(Example 3)
In Example 3, a bundle of 24,000 carbon fibers arranged in one direction (24K) was used as a bundle of reinforcing fibers (PAN-based carbon fiber: TORAYCA (registered trademark) T700 manufactured by Toray Industries, Inc. SC).

  The following thermoplastic epoxy resin solution was applied to one side of the carbon fiber bundle using a kiss roll while pulling out the carbon fiber bundle as it was without performing the fiber opening treatment from the drum around which the carbon fiber bundle was wound. In addition, the cross-sectional shape of the bundle of carbon fibers when pulled out from the drum was a flat shape.

[Thermoplastic epoxy resin solution (viscosity: 450 mPa · s)]
-Thermoplastic epoxy resin (Reactive resin: DENATEITE XNR6850V: manufactured by Nagase ChemteX Corporation) 100 parts-Curing agent (DENATEITE XNH6850V: manufactured by Nagase ChemteX Corporation)
6.5 parts

  Next, the bundle of carbon fibers to which the thermoplastic epoxy resin solution was applied was brought into contact with four rolls (the upper and lower surfaces of the bundle of carbon fibers were alternately contacted twice, respectively), thereby squeezing the bundle of carbon fibers. Then, it is passed through a die to adjust the shape, dried at 60 ° C. for 20 minutes, subsequently heat treated at 150 ° C. for 20 minutes, reacted with a reactive thermoplastic epoxy resin, polymerized, and then passed through a die to prepare the shape. Thus, a substantially circular rod-like fiber reinforced resin material having a diameter of about 2 to 3 mm in cross section was obtained, in which a reactive thermoplastic epoxy resin was applied to a bundle of reinforced fibers arranged in one direction. The glass transition point of the thermoplastic epoxy resin was 100 ° C.

  Next, the obtained rod-like fiber reinforced resin material is cut so as to have a length of 5 mm substantially perpendicular to the axial direction of the carbon fiber, and a strip-like (rod-like) fiber reinforced resin having a substantially circular cross-sectional shape. The material was obtained. The Vf value of the fiber reinforced resin material thus obtained was 30%. The length of the carbon fiber in the obtained fiber reinforced resin material is 5 mm, which is the same as the length of the fiber reinforced resin material because the carbon fiber used is a long fiber.

  When the cut surface of the strip-shaped (rod-shaped) fiber-reinforced resin material was cut 100 times using an electron microscope, it was found that the resin had entered the center of the bundle of carbon fibers.

  The viscosity of the thermoplastic epoxy resin solution used in this example was measured using a B-type viscometer (TVB-15 type viscometer: manufactured by Toki Sangyo Co., Ltd.). Measured at 20, 12 rpm and room temperature.

  Next, the obtained strip-shaped (rod-shaped) fiber-reinforced resin material is put into an injection molding machine, melted while being heated from 120 ° C. to 250 ° C., and the molten resin is injected into a mold, thereby screwing Wood screws were obtained as a shaped product. FIG. 1 is a photograph of a thread-shaped molded body (wood screw) of Example 3, and shows a state when an injection molded product is taken out from a mold after injection molding. FIG. 1 shows a state where two wood screws are connected.

  The appearance quality of the thread-shaped molded body thus obtained was good, and when the cross section of the thread-shaped molded body was observed at a magnification of 100 using an electron microscope, carbon fibers were present in the thread portion. In addition, it was found that the space inside the thread-shaped molded body was not confirmed and was filled with a thermoplastic epoxy resin. Further, the Vf value of the obtained thread-shaped molded body was 30%. Moreover, it was 100 Mpa when the tensile strength of the obtained thread-shaped molded object was measured.

(Example 4)
In Example 4, a rod-like fiber reinforced resin material was manufactured.

  First, a bundle of three 24K carbon fiber bundles (PAN-based carbon fiber, manufactured by Toray Industries, Inc., T700SC), which is twisted 30 times / m in the S direction, is used as a bundle of carbon fibers. The entire periphery of the bundle of carbon fibers was covered with glass fiber in a braid shape by using a fiber maker (24 hammers) on the outer periphery of the bundle, and using a string making machine (24 punching machine).

  Next, the following thermoplastic epoxy resin solution was applied to the bundle of carbon fibers coated with glass fibers by dipping.

[Thermoplastic epoxy resin solution (viscosity: 80 mPa · s or less)]
-Thermoplastic epoxy resin (Reactive resin: DENATEITE XNR6850V: manufactured by Nagase ChemteX Corporation) 100 parts-Curing agent (DENATEITE XNH6850V: manufactured by Nagase ChemteX Corporation)
6.5 parts ・ Methyl ethyl ketone (MEK) 10 parts

  Subsequently, a bundle of carbon fibers coated with a glass fiber coated with a thermoplastic epoxy resin solution was passed through a die to adjust the shape, dried at 60 ° C. for 20 minutes, and then further passed through the die at 150 ° C. for 20 minutes. Heat-treated for minutes to react with a reactive thermoplastic epoxy resin to polymerize it, and a reactive thermoplastic epoxy resin is applied to a bundle of carbon fibers. The cross-sectional shape is approximately 3 mm in diameter (measured with calipers). A fiber reinforced resin material was obtained. The glass transition point of the thermoplastic epoxy resin was 100 ° C. The Vf value of the obtained fiber reinforced resin material was 50%.

  When the cut surface of the fiber reinforced resin material was observed with an electron microscope at a magnification of 100, the thermoplastic epoxy resin had entered the center of the carbon fiber bundle.

  The viscosity of the thermoplastic epoxy resin solution used in this example was measured using a B-type viscometer (TVB-15 type viscometer: manufactured by Toki Sangyo Co., Ltd.). Measured at 20, 12 rpm and room temperature.

  Next, the three obtained fiber reinforced resin materials were twisted together while heating at 120 ° C. to obtain a strand structure.

  Next, a fiber reinforced resin material of the obtained strand structure cut to a length of 25 cm is inserted into a mold for an insert molding / injection molding machine for manufacturing a 12M standard size cutting bolt having a length of 20 cm. Next, the strip-shaped (rod-shaped) fiber reinforced resin material (Vf value is 30%) used in Example 3 was put into an injection molding machine and melted while being heated from 120 ° C. to 250 ° C. The resin was injected into the mold, cooled, removed from the mold, and unnecessary portions were removed to obtain 20 cm long, M12 sized bolts.

  The appearance of the thread-shaped molded body (dimension bolt) obtained in this way is good, and when the cross section of the thread-shaped molded body was observed at 100 times using an electron microscope, the thread portion was carbon. There are fibers, and there is no space inside the thread-shaped molded body. The rod-shaped (strand structure) fiber-reinforced resin material and strip-shaped (bar-shaped) fiber-reinforced resin are oriented in the length direction. It was found that it was filled with reinforced fibers and thermoplastic epoxy resin that were supposed to be derived. Moreover, it was 130 Mpa when the tensile strength of the obtained screw-shaped molded object was measured.

  In addition, when all of the thread-shaped molded bodies of Examples 1, 2, 3, and 4 were measured for tensile strength, the bolt body portion or the wood screw shaft portion was broken without cutting the thread portion. Therefore, it was confirmed that the thread portion has sufficient strength.

(Summary)
As described above, the thread-shaped molded body according to the present embodiment is light and does not generate rust, does not easily cause dew condensation, is not easily magnetized, has excellent form stability against water, moisture, etc., and is loose. Difficult, yet strong and durable.

  Thereby, for example, by using the screw-shaped molded body according to the present embodiment as a fastening member such as a screw or a bolt when joining wood such as a wooden building, the weight burden on the wood is reduced. In addition, since it is difficult for condensation to occur, the condensation can be suppressed and the corrosion of the wood can be suppressed. Furthermore, the joining of the wood can be maintained without sagging over a long period of time.

  In addition, by using the screw-shaped molded body according to the present embodiment as a fastening member such as a screw or a bolt when joining a metal material such as a steel material used in the construction / civil engineering field, a transport machine or a machine tool, The occurrence of rust due to salt damage or condensation can be suppressed, and the joining of metal materials can be maintained without loosening over a long period of time.

  Moreover, the screw-shaped molded body according to the present embodiment is used as a fastening member such as a screw or a bolt when joining a fiber reinforced resin member used in a transport machine such as a car, a train, or an airplane or a machine tool in a factory. Thus, it is possible to suppress the occurrence of rust and realize a light and durable joint structure of fiber reinforced resin members. Further, it is possible to maintain the bonding of the fiber reinforced resin member without loosening for a long time.

  In addition, for wood, metal materials, fiber reinforced resin members, etc., even when joining members of different materials, by using the screw-shaped molded body according to the present embodiment, it is light and prevents the occurrence of rust. It is possible to maintain the bonding between the members without loosening.

  Further, since the screw-like molded body according to the present embodiment is not easily magnetized, it can be used as a fastening member such as a screw, a bolt, or a nut in a field using magnetism such as a linear motor car.

  The thread-shaped molded body according to the present invention is light and does not generate rust, does not easily cause dew condensation, is not easily magnetized, has excellent form stability against water, moisture, etc., and does not easily sag, Since it is strong and excellent in durability, it is suitable for joining any member including wood joining or metal joining.

Claims (7)

  A thread-shaped molded body obtained by using a fiber reinforced resin material containing a reinforced fiber and a thermoplastic epoxy resin.   The screw-shaped molded product according to claim 1, wherein the thermoplastic epoxy resin is a reactive epoxy resin.   The thread-shaped molded body according to claim 1 or 2, wherein the length of the reinforcing fiber is more than 1 mm.   The thread-shaped molded body according to any one of claims 1 to 3, wherein the reinforcing fiber is a three-dimensional fiber structure.   The thread-shaped molded body according to any one of claims 1 to 4, wherein the reinforcing fiber is a tubular braid or a knitted fabric.   The screw-shaped molded body according to any one of claims 1 to 5, wherein a fiber volume ratio of the thread-shaped molded body is 20 to 80%.   The thread-shaped molded body according to any one of claims 1 to 6, wherein the thread-shaped molded body has a tensile strength of 80 MPa or more when measured according to JIS Z2241.