JP2018119055A - Pultrusion molded body, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pultrusion molded body suppressed in disarray of carbon fibers oriented in an oblique direction to MD, and sufficiently high in a strength per unit mass.SOLUTION: The pultrusion molded body containing a matrix resin which is a cured product of a thermosetting composition, and a reinforcing fiber substrate includes, as reinforcing fiber substrates, a first reinforcing fiber substrate composed of a plurality of carbon fibers oriented to MD, and a second reinforcing fiber substrate 30 obtained by binding a plurality of carbon fibers (obliquely oriented carbon fibers 32) and at least one inorganic fiber yarn 38 with a first stitching yarn 40.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a pultruded article and a method for producing the same.

  A molded body of a fiber reinforced composite material including a matrix resin and reinforcing fibers is used in various applications because of excellent properties such as high strength, high rigidity, and light weight. As the reinforcing fibers, inorganic fibers such as glass fibers and carbon fibers, and organic fibers such as aramid fibers are used. In particular, fiber reinforced composite materials using carbon fibers as reinforcing fibers tend to be excellent in strength and rigidity.

  There is a pultrusion method (pultrusion method) as one of the methods for producing a fiber-reinforced composite material molded body. In the pultrusion method, a reinforcing fiber base material is impregnated with a thermosetting composition, the reinforcing fiber base material impregnated with the thermosetting composition is drawn into a thermoforming mold, and the thermosetting composition is formed in the thermoforming mold. Is cured to obtain a molded body having a predetermined shape, and the molded body is drawn out from the thermoforming mold to obtain a molded body of fiber reinforced composite material (hereinafter also referred to as a pultruded molded body). The pultrusion method has an advantage that a pultruded body can be continuously produced.

  In the pultrusion method, the thermosetting composition is required to have low viscosity, fast curability and the like. In the pultrusion method, the reinforcing fibers aligned in one direction are usually drawn into the thermoforming mold along the drawing direction, that is, MD (Machine Direction) (Patent Document 1). The pultruded article obtained in this manner is excellent in MD strength because it contains reinforcing fibers oriented in MD. However, the pultruded body does not have sufficient strength in directions other than MD.

  In order to increase the strength in the direction other than MD in the pultruded molded body, a plurality of reinforcing fibers oriented in an oblique direction with respect to MD together with the first reinforcing fiber base made of a plurality of reinforcing fibers oriented in MD (hereinafter referred to as “MD”) It is conceivable to simultaneously draw the second reinforcing fiber base material including the obliquely oriented reinforcing fibers into the thermoforming mold. However, in the pultrusion method, since a high tension is applied to the reinforcing fiber base drawn into the thermoforming mold, the obliquely oriented reinforcing fibers in the second reinforcing fiber base are likely to be disturbed. For example, when the reinforcing fiber is a carbon fiber, in the second reinforcing fiber base material that is more slippery than the glass fiber and extended to MD by high tension, the orientation angle of the obliquely oriented reinforcing fiber becomes small, and the second reinforcing fiber There is a problem that both side edges of the base material come to the center.

  As a method for suppressing the disorder of obliquely oriented reinforcing fibers in the pultrusion method, a method in which a thin layer containing a mat component is integrally held on the surface of a second reinforcing fiber substrate containing obliquely oriented reinforcing fibers has been proposed. (Patent Document 2).

JP 2008-038082 A JP 2010-125660 A

However, since the mat component (chopped strand mat or the like) has no orientation, the method of Patent Document 2 has a problem in that the strength per unit mass of the pultruded product is lowered.
The present invention provides a pultruded article in which the disturbance of carbon fibers oriented in an oblique direction with respect to MD is suppressed and the strength per unit mass is sufficiently high, and a method for producing the same.

The present invention has the following aspects.
<1> A pultruded molded body including a matrix resin which is a cured product of a thermosetting composition and a reinforced fiber base material; a first reinforcement composed of a plurality of carbon fibers oriented in MD as the reinforced fiber base material A fibrous base material, and a plurality of carbon fibers oriented obliquely with respect to MD and a second reinforcing fiber base material in which at least one inorganic fiber yarn oriented in MD is bound by stitching yarn , Pultruded body.
<2> The pultruded article according to <1>, wherein the matrix resin is a cured product of a thermosetting composition containing an epoxy resin.
<3> The thermosetting composition and the reinforcing fiber substrate are drawn into a thermoforming mold, and the thermosetting composition is cured in the thermoforming mold to obtain a molded body having a predetermined shape. A method of producing a pultruded molded body by pulling out the molded body from a mold; as the reinforced fiber base material, a first reinforced fiber base material composed of carbon fibers in which carbon fibers are oriented in MD, and an oblique direction with respect to MD A method for producing a pultruded article using a plurality of carbon fibers oriented in the direction and a second reinforcing fiber base material in which at least one inorganic fiber yarn oriented in MD is bound by stitching yarns.
<4> The tension applied to the second reinforcing fiber base drawn into the thermoforming mold is lower than the tension applied to the first reinforcing fiber base drawn into the thermoforming mold. 3> A method for producing a pultruded article.
<5> Production of a pultruded article is started using a thermosetting composition containing a vinyl ester resin as the thermosetting composition, and then the thermosetting composition contains an epoxy resin. The method for producing a pultruded article according to <3> or <4>, wherein

In the pultruded article of the present invention, the disturbance of the carbon fibers oriented in an oblique direction with respect to MD is suppressed, and the strength per unit mass is sufficiently high.
According to the method for producing a pultruded article of the present invention, it is possible to produce a pultruded article that can suppress the disorder of carbon fibers oriented obliquely with respect to MD and that has a sufficiently high strength per unit mass.

It is a perspective view which shows an example of the pultrusion molded object of this invention. It is II-II sectional drawing of FIG. It is a top view which shows an example of a 1st reinforcement fiber base material. It is a top view which shows an example of the 2nd reinforcement fiber base material. It is a bottom view of the 2nd reinforcing fiber base material of FIG. It is VI-VI sectional drawing of FIG. It is VII-VII sectional drawing of FIG. It is the schematic which shows an example of the manufacturing apparatus of a pultrusion body.

<Pulled molded body>
FIG. 1 is a perspective view showing an example of a pultruded article of the present invention.
The pultruded molded body 10 is a flat molded body that extends in an MD (Machine Direction) that is a pultrusion direction, and includes a matrix resin and a reinforcing fiber substrate.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, that is, a cross section orthogonal to the MD of the pultruded body 10.
The pultruded article 10 includes a first surface layer 12 including a first main surface A, a second surface layer 14 including a second main surface B, and between the first surface layer 12 and the second surface layer 14. And the intermediate layer 16.
The first surface layer 12, the second surface layer 14, and the intermediate layer 16 are distinguished from each other by differences in the form of the reinforcing fiber base, the orientation of the reinforcing fibers in the reinforcing fiber base, and the like.

  The volume content (Vf) of the reinforcing fiber in the pultruded body 10 is preferably 35 to 75%, and more preferably 55 to 65%. When Vf is within the above range, the pultruded product 10 has higher strength, higher elastic modulus, and lighter weight. Vf is obtained from the volume per unit length of the product, the mass of the reinforced fibers introduced, and the specific gravity thereof.

(Middle layer)
The intermediate layer 16 includes a matrix resin and a first reinforcing fiber base material.
The first reinforcing fiber base is composed of a plurality of carbon fibers oriented in MD.

FIG. 3 is a top view illustrating an example of the first reinforcing fiber base material.
The first reinforcing fiber base 20 is an MD-oriented carbon fiber sheet in which a plurality of bundles of carbon fiber tows composed of a plurality of carbon fibers 22, 22... Oriented in the MD are arranged without gaps along the MD direction. 24.
The first reinforcing fiber base material 20 in which the carbon fibers 22 are oriented in the MD contributes to the improvement in the MD strength of the pultruded molded body 10.

Examples of the carbon fiber 22 include polyacrylonitrile (PAN) -based carbon fiber, pitch-based carbon fiber, and rayon-based carbon fiber. As the carbon fiber 22, a PAN-based carbon fiber is preferable.
The diameter (filament diameter) of the carbon fiber 22 is usually 1 to 20 μm.
The carbon fiber 22 may be surface-treated with a sizing agent. A well-known thing is mentioned as a sizing agent. Before applying the sizing agent, the surface of the carbon fiber 22 may be oxidized. Examples of the oxidation treatment include liquid phase treatment and gas phase treatment.

The carbon fiber tow refers to a long fiber bundle composed of an extremely large number of filaments and having no twist.
The number of carbon fibers (filaments) constituting the carbon fiber tow is usually 1000 to 72,000.
The fineness of the carbon fiber tow is usually 660 to 16500 dtex.
The tensile strength of the carbon fiber tow is usually 3000 to 8000 MPa.
The tensile elastic modulus of the carbon fiber tow is usually 200 to 800 GPa.
The elongation of the carbon fiber tow is usually 0.5 to 3.0%.
The tensile properties (tensile strength, tensile modulus and elongation) of the carbon fiber tow are measured in accordance with JIS R 7606: 2000 (corresponding international standard ISO 11466: 1996).
The density of the carbon fiber tow is usually 17 to 20 dg / cm ³ .

  The thickness of the intermediate layer 16 is preferably 0.3 mm to 10 cm. The thickness of the intermediate layer 16 is the thickness in the thickness direction of the pultruded molded body 10.

(Surface)
The first surface layer 12 and the second surface layer 14 include a matrix resin and a second reinforcing fiber base material.
The second reinforcing fiber base material includes a plurality of carbon fibers oriented in an oblique direction with respect to MD (hereinafter also referred to as obliquely oriented carbon fibers) and at least one inorganic fiber yarn oriented in the MD as stitching yarns. They are united and integrated by strips.

FIG. 4 is a top view showing an example of the second reinforcing fiber base, and FIG. 5 is a bottom view of the second reinforcing fiber base of FIG.
The second reinforcing fiber base 30 is a first in which a plurality of bundles of carbon fiber tows composed of a plurality of obliquely oriented carbon fibers 32, 32,. In the direction orthogonal to the carbon fibers 32 of the first obliquely oriented carbon fiber sheet 34, a plurality of bundles of carbon fiber tows composed of the obliquely oriented carbon fiber sheet 34; And the second obliquely oriented carbon fiber sheet 36 disposed without gaps along the oblique direction with respect to the MD; and disposed at a predetermined interval on the surface of the second obliquely oriented carbon fiber sheet 36 along the MD. A plurality of the inorganic fiber yarns 38; the first obliquely oriented carbon fiber sheet 34, the second obliquely oriented carbon fiber sheet 36, and the inorganic fiber yarn 38 in the MD at the same position as the inorganic fiber yarn 38. Chain stitch along A plurality of first stitching yarns 40 that are bundled and integrated by single ring stitching); a first obliquely oriented carbon fiber sheet 34 and a second obliquely oriented carbon fiber sheet 36; And a plurality of second stitching yarns 42 which are bundled and integrated by main stitching along the MD at an intermediate position between the yarns 38.

The second reinforcing fiber base material 30 having the obliquely oriented carbon fibers 32 contributes to an improvement in strength other than the MD of the pultruded molded body 10.
In addition, the second reinforcing fiber base material 30 in which the obliquely oriented carbon fibers 32 are reinforced by the inorganic fiber yarns 38 oriented in the MD and these are bound by the first stitching yarns 40 has a high tension in the MD. Even if it takes, it is hard to extend to MD. Therefore, the orientation angle of the obliquely oriented carbon fibers 32 is not easily reduced, and both side edges of the second reinforcing fiber base 30 are not easily moved to the center, that is, the obliquely oriented carbon fibers 32 in the second reinforcing fiber base 30 are disturbed. It can be suppressed.

Examples of the obliquely oriented carbon fibers 32 include the same fibers as the carbon fibers 22 in the first reinforcing fiber base 20, and the preferred forms are also the same.
As carbon fiber tow, the thing similar to the carbon fiber tow in the 1st reinforcement fiber base material 20 is mentioned, A preferable form is also the same.

  The orientation angle of the obliquely oriented carbon fibers 32 in the first obliquely oriented carbon fiber sheet 34 is preferably + 10 ° or more and less than + 90 °, more preferably + 20 ° or more and + 80 ° or less, and + 30 ° with respect to MD (0 °). More preferably, it is + 70 ° or less. If the orientation angle is within the above range, the strength of the pultruded body 10 in directions other than the MD is more excellent. The orientation angle of the obliquely oriented carbon fibers 32 in the first obliquely oriented carbon fiber sheet 34 in the illustrated example is + 45 °.

  The orientation angle of the obliquely oriented carbon fibers 32 in the second obliquely oriented carbon fiber sheet 36 is preferably more than −90 ° and −10 ° or less, and more preferably −80 ° or more and −20 ° or less with respect to MD (0 °). Preferably, it is more preferably −70 ° or more and −30 ° or less. If the orientation angle is within the above range, the strength of the pultruded body 10 in directions other than the MD is more excellent. The orientation angle of the obliquely oriented carbon fibers 32 in the second obliquely oriented carbon fiber sheet 36 in the illustrated example is −45 °.

  Examples of the inorganic fiber constituting the inorganic fiber yarn 38 include glass fiber, carbon fiber, graphite fiber, silicon carbide fiber, silicon nitride fiber, alumina fiber, silicon carbide fiber, boron fiber, metal fiber (aluminum fiber, brass fiber). , Stainless fiber, etc.). As the inorganic fiber, glass fiber or carbon fiber is preferable and glass fiber is more preferable from the viewpoint of availability and affinity balance with resin.

Examples of the material of the glass fiber include E glass, C glass, S glass, and the like. E glass is preferable from the viewpoint of balance of price, availability, and affinity with resin.
The diameter (filament diameter) of the glass fiber is usually 3 to 50 μm.

As the form of the inorganic fiber yarn 38, a yarn is preferable from the viewpoint of workability and availability.
The fineness of the inorganic fiber yarn is usually 1000 to 5000 dtex.
The inorganic fiber yarn may be a bulky yarn. A bulky yarn is a bulky twisted yarn.

As the fibers constituting the first stitching yarn 40 and the second stitching yarn 42, organic fibers are preferable from the viewpoint of ease of sewing. Examples of the material of the organic fiber include polyester, nylon and the like, and polyester is preferable from the viewpoint of ease of sewing.
As the form of the first stitching yarn 40 and the second stitching yarn 42, a yarn is preferable from the viewpoint of ease of sewing.

  FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5, that is, a cross-sectional view taken along the first stitching yarn 40 of the second reinforcing fiber base 30. The stitches of the first stitching thread 40 are chain stitches (single-ring stitches), and loop needle loops that are continuous with MD along the surface of the first obliquely oriented carbon fiber sheet 34; A linear sinker loop that passes through the obliquely oriented carbon fiber sheet 34 and the second obliquely oriented carbon fiber sheet 36 and is continuous with the MD along the surface of the second obliquely oriented carbon fiber sheet 36, and connects between the needle loops; Consists of. In addition, in FIG. 6, illustration of the inorganic fiber yarn 38 is abbreviate | omitted from the point of the ease of description of a figure.

  FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 5, that is, a cross-sectional view taken along the second stitching yarn 42 of the second reinforcing fiber substrate 30. The stitches of the second stitching thread 42 are main stitches (straight stitches), and as shown in FIG. 7, the first diagonally oriented carbon fiber sheet 34 and the second diagonally oriented carbon fiber sheet are spaced at a predetermined interval. The lower thread 42b is passed through the loop of the upper thread 42a penetrating the thread 36, and the intersection of the upper thread 42a and the lower thread 42b is near the boundary between the first obliquely oriented carbon fiber sheet 34 and the second obliquely oriented carbon fiber sheet 36. It is a straight seam formed by pulling up.

The thicknesses of the first obliquely oriented carbon fiber sheet 34 and the second obliquely oriented carbon fiber sheet 36 are set according to the thickness of each of the first surface layer 12 and the second surface layer 14.
The thicknesses of the first surface layer 12 and the second surface layer 14 are preferably 0.5 mm to 5 cm, respectively. The thicknesses of the first surface layer 12 and the second surface layer 14 are the thicknesses in the thickness direction of the pultruded body 10.

(Matrix resin)
The matrix resin is a cured product of the thermosetting composition.
Examples of the thermosetting composition include those containing a thermosetting resin and an additive (such as a curing agent).
Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, urea / melamine resins, polyimides, bismaleimide resins, cyanate ester resins, etc. Affinity with carbon fibers, mechanical properties From the standpoint of expression of the epoxy resin, an epoxy resin is preferable.

  When the thermosetting resin is an epoxy resin, examples of the thermosetting composition include a composition including an epoxy resin, a curing agent, a curing accelerator, and a release agent. The thermosetting composition is usually liquid at 25 ° C.

  Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin and bisphenol S type epoxy resin; novolak type epoxy resins such as phenol novolac type epoxy resin and cresol novolac type epoxy resin; Examples thereof include glycidylamine type epoxy resins such as diphenylmethane, triglycidylaminophenol, and tetraglycidylxylenediamine; and glycidyl ether type epoxy resins such as tetrakis (glycidyloxyphenyl) ethane and tris (glycidyloxy) methane. An epoxy resin may be used individually by 1 type, and may use 2 or more types together. As the epoxy resin, a bisphenol A type epoxy resin is preferable from the viewpoint of balance between availability and cost and the strength of the pultruded molded body 10.

Examples of the curing agent include acid anhydrides, dicyandiamides, aliphatic polyamines, etc., and the curing reaction hardly proceeds under the temperature conditions (for example, −10 to 40 ° C.) before drawing into the thermoforming mold, and the thermoforming mold. An acid anhydride is preferable from the viewpoint that the curing reaction easily proceeds when heated by, for example.
Examples of the acid anhydride include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, dodecyl succinic anhydride, and the like. An acid anhydride may be used individually by 1 type, and may use 2 or more types together. As the acid anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride are preferred from the viewpoint of low viscosity at 25 ° C. and excellent heat resistance of the resulting cured product.

Examples of the curing accelerator include imidazole derivatives, phosphines, tertiary amine salts and the like, and imidazole derivatives are preferable from the viewpoint of balance between curing time and pot life.
Examples of imidazole derivatives include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2- Examples include methylimidazole, 1-isobutyl-2-methylimidazole, 1-aminoethyl-2-methylimidazole, and the like. An imidazole derivative may be used individually by 1 type and may use 2 or more types together.

When the thermosetting composition contains the internal mold release agent, it can be satisfactorily pulled out from the thermoforming mold.
Examples of the internal mold release agent include known internal mold release agents in the field of pultrusion molding. As the internal mold release agent, an internal mold release agent which is liquid at 25 ° C. is preferable. In pultrusion molding, in order to quickly impregnate the reinforcing fiber substrate with the thermosetting composition, a thermosetting composition having a low viscosity is used. Therefore, an epoxy resin having a low viscosity is used. If the internal release agent is liquid, it can be mixed well with an epoxy resin or the like.
Examples of the internal release agent that is liquid at 25 ° C. include organic acid derivatives and silicone oil. Commercially available internal release agents that are organic acid derivatives include Axel Plastics Research Laboratories, Inc. Examples thereof include MoldWiz (registered trademark) INT-1846, INT-1836, INT-1850, INT-1854, INT-1888LE, and the like. Examples of commercially available internal mold release agents that are silicone oils include KF-96, which is a dimethyl silicone oil manufactured by Shin-Etsu Chemical Co., Ltd.

Content of the hardening | curing agent in a thermosetting composition can be suitably set according to the kind etc. of hardening | curing agent. For example, the content of the acid anhydride can be set such that the ratio of the epoxy value of the epoxy resin / the acid value of the acid anhydride falls within a range of 1/1 to 1 / 1.2.
Content of the hardening accelerator in a thermosetting composition can be suitably set according to the kind etc. of hardening accelerator. When a hardening accelerator is an imidazole derivative, content of an imidazole derivative can be 0.2-10 mass parts with respect to 100 mass parts of epoxy resins, for example.
Content of the internal mold release agent in a thermosetting composition can be 0.2-10 mass parts with respect to 100 mass parts of epoxy resins, for example.
The thermosetting composition may further include other components other than the epoxy resin, the acid anhydride, the curing accelerator, and the release agent. Examples of other components include a filler and a reactive diluent.

  The viscosity of the thermosetting composition at 25 ° C. is preferably 500 to 10,000 mPa · s, more preferably 1000 to 3000 mPa · s. If the viscosity at 25 ° C. is equal to or lower than the upper limit of the above range, the thermosetting composition is easily impregnated into the reinforcing fiber base. If the viscosity at 25 ° C. is equal to or higher than the lower limit of the above range, the thermosetting composition is easily held on the reinforcing fiber substrate. The viscosity at 25 ° C. of the thermosetting composition is a value measured by a B-type viscometer.

  The curing time at 150 ° C. of the thermosetting composition is preferably 10 to 600 seconds, and more preferably 30 to 240 seconds. If the curing time at 150 ° C. is less than or equal to the upper limit of the above range, it is sufficiently cured under normal curing conditions in pultrusion molding. The gel time is a value measured by a test in which the bath temperature is set to 150 ° C. with reference to JIS K 6901: 2008.

(Mechanism of action)
In the pultruded article 10 described above, since the first reinforcing fiber base material 20 including the plurality of carbon fibers 22 oriented in the MD is included as the reinforcing fiber base material, the strength of the MD is excellent.
Moreover, in the pultruded body 10, since the second reinforcing fiber base 30 having the plurality of obliquely oriented carbon fibers 32 is included as the reinforcing fiber base, the strength other than MD is also excellent.
Moreover, in the pultruded article 10, the second reinforcing fiber base material 30 is reinforced by the inorganic fiber yarns 38 in which the obliquely oriented carbon fibers 32 are oriented in the MD, and these are the first stitching yarns. 40, the second reinforcing fiber base material 30 is hardly stretched even when a high tension is applied to the MD. Therefore, the orientation angle of the obliquely oriented carbon fibers 32 is not easily reduced, and both side edges of the second reinforcing fiber base 30 are not easily moved to the center, that is, the obliquely oriented carbon fibers 32 in the second reinforcing fiber base 30 are disturbed. It can be suppressed.
Further, in the pultruded molded body 10, a thin layer containing a mat component is integrally formed on the surface of the second reinforcing fiber base in order to suppress the disturbance of the obliquely oriented reinforcing fibers as in the conventional pultruded molded body. There is no need to hold it. The pultruded article 10 that does not contain a non-orientated mat component has a sufficiently high strength per unit mass.

(Other embodiments)
The pultruded article of the present invention is a pultruded article comprising a matrix resin that is a cured product of a thermosetting composition and a reinforcing fiber substrate, and a plurality of carbon fibers oriented in MD as the reinforcing fiber substrate. A second reinforcing fiber in which a plurality of carbon fibers oriented in an oblique direction with respect to MD and at least one inorganic fiber yarn oriented in MD are bound together by stitching yarns. What is necessary is just to include a fiber base material, and it is not limited to the pultruded article 10 of the example of illustration.

For example, the pultruded article of the present invention may have a two-layer structure of a layer including a first reinforcing fiber substrate and a layer including a second reinforcing fiber substrate.
The pultruded article of the present invention includes a first surface layer including a first reinforcing fiber substrate, a second surface layer including a first reinforcing fiber substrate, and an intermediate layer including a second reinforcing fiber substrate. It may have.
The shape of the pultruded article of the present invention is not limited to the flat plate shape (flat bar shape) in the illustrated example, but may be a cross-sectional L shape (angle shape), a cross-sectional T shape, or a cross-sectional C shape. (Channel shape), a cross-sectional H shape, a square pipe shape, a round pipe shape, or other pultrusable shapes may be used.

In addition to the obliquely oriented carbon fiber sheet composed of a plurality of obliquely oriented carbon fibers, the second reinforcing fiber base material is oriented in an MD oriented carbon fiber sheet composed of a plurality of carbon fibers oriented in MD and TD (Transverse Direction). You may further have any one or both of the TD orientation carbon fiber sheet which consists of a some carbon fiber.
The second reinforcing fiber base material may have a carbon fiber fabric made of obliquely oriented carbon fibers instead of the two obliquely oriented carbon fiber sheets. Examples of the structure of the carbon fiber fabric include plain weave and twill weave.
The second reinforcing fiber base material may be one in which one obliquely oriented carbon fiber sheet and inorganic fiber yarns are bound by stitching yarns.
The stitches of the first stitching thread in the second reinforcing fiber base material are not limited to the chain stitch (single-ring stitch) in the illustrated example, and may be double-ring stitches. It may be a warp knitting (excluding chain stitches) joined together. Examples of the type of warp knitting include those described in JIS L 0211: 2006 “Fiber Term-Knit Division”.

<Method for producing pultruded body>
In the pultrusion method, a thermosetting composition and a reinforcing fiber base material are drawn into a thermoforming mold, and the thermosetting composition is cured in the thermoforming mold to form a molded body having a predetermined shape. This is a method of pulling out the molded body from
In the method for producing a pultruded article of the present invention, as a reinforcing fiber base, a first reinforcing fiber base made of carbon fibers in which carbon fibers are oriented in MD, and a plurality of carbons oriented obliquely with respect to MD A fiber and a second reinforcing fiber substrate in which at least one inorganic fiber yarn oriented in MD is bound by stitching yarn are used.

FIG. 8 is a schematic view showing an example of a pultruded body manufacturing apparatus.
The manufacturing apparatus 50 includes: a thermoforming mold 52; a resin tank 54 that is disposed upstream of the thermoforming mold 52 and stores a thermosetting composition; and is disposed downstream of the thermoforming mold 52. A drawing machine 56; a cutting machine 58 disposed downstream of the drawing machine 56; a plurality of bobbins (not shown) for supplying a plurality of carbon fiber tows constituting the first reinforcing fiber substrate 20; A plurality of guide rolls 60 for guiding the reinforcing fiber base material 20 to the resin tank 54 and guiding the first reinforcing fiber base material 20 impregnated with the thermosetting composition in the resin tank 54 to the thermoforming mold 52. And; a first supply roll 62 for supplying the second reinforcing fiber base material 30 on the first surface layer side; and a second supply roll 64 for supplying the second reinforcing fiber base material 30 on the second surface layer side. And thermosetting different from the thermosetting composition of the resin tank 54 disposed on the upstream side of the resin tank 54 And a coating device 66 for applying a composition to the first reinforcing fiber base 20.

  In the thermoforming mold 52, a space S having a cross-sectional shape corresponding to the cross-sectional shape of the pultruded molded body 10 and through which a reinforcing fiber base material can be inserted is formed. The thermoforming mold 52 is provided with a heating mechanism (not shown) for heating and curing the thermosetting composition drawn into the space S.

Manufacture of the pultruded article 10 using the manufacturing apparatus 50 is performed by the following procedure, for example.
The first reinforcing fiber substrate 20 is immersed in a resin tank 54 in which a liquid thermosetting composition is stored, and the first reinforcing fiber substrate 20 is impregnated with the thermosetting composition. The first reinforcing fiber base material 20 impregnated with the thermosetting composition is pulled up from the resin tank 54 and taken out by the drawing machine 56 to be drawn into the space S of the thermoforming mold 52. At the same time, the two second reinforcing fiber bases 30 supplied from the first supply roll 62 and the second supply roll 64 are drawn by the drawing machine 56 so as to sandwich the first reinforcing fiber base 20. As a result, the heat forming mold 52 is pulled into the space S. The thermosetting composition is cured in the thermoforming mold 52 to obtain a molded body, which is drawn from the thermoforming mold 52 by the drawing machine 56 to obtain the pultruded molded body 10. The pultruded body 10 is cut by a cutting machine 58 so as to have a predetermined length as necessary.

  The second reinforcing fiber base 30 before being drawn into the thermoforming mold 52 may or may not be impregnated with the thermosetting composition. Even when not impregnated, the second reinforcing fiber base 30 is impregnated with the thermosetting composition impregnated in the first reinforcing fiber base 20 when drawn into the thermoforming mold 52.

  When the two second reinforcing fiber base materials 30 are drawn into the thermoforming mold 52 from the first supply roll 62 and the second supply roll 64, the second reinforcing fibers are drawn into the thermoforming mold 52. It is preferable that the tension applied to the base material 30 is lower than the tension applied to the first reinforcing fiber base material 20 drawn into the thermoforming mold 52. Since the second reinforcing fiber substrate 30 has few reinforcing fibers oriented in the MD, the second reinforcing fiber substrate 30 has a lower strength against the tensile force of the MD than the first reinforcing fiber substrate 20. Therefore, when the 2nd reinforcement fiber base material 30 is taken up with the same tension | tensile_strength as the 1st reinforcement fiber base material 20 with the drawing machine 56, the reinforcement fiber of the 2nd reinforcement fiber base material 30 tends to fracture | rupture. By making the tension applied to the second reinforcing fiber substrate 30 drawn into the thermoforming mold 52 lower than the tension applied to the first reinforcing fiber substrate 20 drawn into the thermoforming mold 52, the second Breakage of the reinforcing fibers in the reinforcing fiber base 30 is suppressed.

  As a specific method for lowering the tension applied to the second reinforcing fiber substrate 30 drawn into the heating mold 52 than the tension applied to the first reinforcing fiber substrate 20 drawn into the heating mold 52, A method of loosening the second reinforcing fiber base 30 between the first supply roll 62 or the second supply roll 64 and the thermoforming mold 52 is mentioned. In order to loosen the second reinforcing fiber substrate 30 between the first supply roll 62 or the second supply roll 64 and the thermoforming mold 52, for example, each supply roll has a predetermined supply roll. Release or release the brake (not shown) that applies torque.

  When a thermosetting composition containing an epoxy resin is used as the thermosetting composition, a molded body formed by curing the thermosetting composition in the thermoforming mold 52 and the space of the thermoforming mold 52 The drawing resistance between the inner wall of S increases. The drawing resistance is particularly high immediately after the start of the production of the pultruded body. Therefore, immediately after the start of the production of the pultruded body, the tension applied to the reinforcing fiber base is increased, and the reinforcing fibers of the reinforcing fiber base are easily broken.

  Therefore, when using a thermosetting composition containing an epoxy resin as a thermosetting composition, start production of a pultruded article using a thermosetting composition containing a vinyl ester resin as a thermosetting composition, After the tension applied to the reinforcing fiber base is stabilized, it is preferable to switch the thermosetting composition to a thermosetting composition containing an epoxy resin. When a thermosetting composition containing a vinyl ester resin is used as the thermosetting composition, the drawing resistance between the molded body in the thermoforming mold 52 and the inner wall of the space S is relatively low. Therefore, immediately after the start of the production of the pultruded body, the tension applied to the reinforcing fiber base is not so high, and the reinforcing fibers of the reinforcing fiber base are not easily broken.

The thermosetting composition is switched as follows, for example.
In a state where the first reinforcing fiber base 20 is pulled upward from the thermosetting composition containing the epoxy resin in the resin tank 54, the vinyl ester resin is applied to the first reinforcing fiber base 20 from the coating device 66. The containing thermosetting composition is applied. The first reinforcing fiber base material 20 coated with the thermosetting composition containing the vinyl ester resin is taken out by the drawing machine 56 together with the two second reinforcing fiber base materials 30. Pull into space S. The thermosetting composition containing the vinyl ester resin is cured in the thermoforming mold 52 to form a molded body, which is pulled out from the thermoforming mold 52 by a drawing machine 56.
The molded body is continuously pulled out until the tension applied to the reinforcing fiber base is stabilized. After the tension applied to the reinforcing fiber substrate is stabilized, the first reinforcing fiber substrate 20 is immersed in the resin tank 54 in which the liquid thermosetting composition containing the epoxy resin is stored, and at the same time, the first reinforcing fiber is used. Application of the thermosetting composition containing the vinyl ester resin from the coating device 66 to the base material 20 is stopped. Thereafter, the production of the normal pultruded body 10 is continued.

10-40 degreeC is preferable and the temperature of the resin tank 54 has more preferable 20-30 degreeC. If the temperature of the resin tank 54 is less than or equal to the upper limit of the above range, thickening due to the start of the curing reaction of the thermosetting composition can be suppressed. When the temperature of the resin tank 54 is equal to or higher than the lower limit of the above range, the impregnation property of the thermosetting composition into the reinforcing fiber base is good.
The temperature of the thermoforming mold 52 is preferably 100 to 250 ° C, more preferably 120 to 220 ° C. If the temperature of the thermoforming mold 52 is within the above range, curing of the thermosetting composition in the thermoforming mold 52 proceeds well.
The residence time in the thermoforming mold 52 is preferably 30 seconds to 5 minutes. If the residence time is 30 seconds or longer, the thermosetting composition is sufficiently cured in the thermoforming mold 52, and the appearance of the pultruded molded body 10 is good. If the residence time is 5 minutes or less, the pultruded body 10 can be easily pulled out from the thermoforming mold 52.

Aftercure molding 10 may be further subjected to after cure.
After-curing may be performed online by installing an oven on the downstream side of the thermoforming mold 52, or may be performed off-line.
The after-curing temperature is preferably from 130 to 220 ° C, more preferably from 140 to 200 ° C, from the viewpoint of physical properties such as heat resistance and productivity. The after-curing time depends on the after-curing temperature, but is preferably 5 minutes to 6 hours.

(Mechanism of action)
In the manufacturing method of the pultruded article 10 described above, since the first reinforcing fiber substrate 20 composed of a plurality of carbon fibers 22 oriented in MD is used as a part of the reinforcing fiber substrate, MD The pultruded article 10 having excellent strength can be manufactured.
Moreover, in the manufacturing method of the pultruded body 10, since the second reinforcing fiber substrate 30 having a plurality of obliquely oriented carbon fibers 32 is used as a part of the reinforcing fiber substrate, the strength other than MD is used. It is possible to produce a pultruded article 10 that is also excellent.
Moreover, in the manufacturing method of the pultruded body 10, the second reinforcing fiber base material 30 is reinforced by the inorganic fiber yarn 38 in which the obliquely oriented carbon fibers 32 are oriented in the MD, and these are the first stitches. Since it is bundled by the thread yarn 40, even if high tension is applied to the MD with respect to the second reinforcing fiber base 30, it is difficult to extend to the MD. Therefore, the orientation angle of the obliquely oriented carbon fibers 32 is not easily reduced, and both side edges of the second reinforcing fiber base 30 are not easily moved to the center, that is, the obliquely oriented carbon fibers 32 in the second reinforcing fiber base 30 are disturbed. It can be suppressed.
Moreover, in the manufacturing method of the pultruded molded body 10, a mat component is included on the surface of the second reinforcing fiber base in order to suppress the disorder of the obliquely oriented reinforcing fibers as in the conventional manufacturing method of the pultruded molded body. There is no need to hold the thin layer together. Therefore, the pultruded article 10 having a sufficiently high strength per unit mass can be produced without including a mat component having no orientation.

(Other embodiments)
In the method for producing the pultruded article of the present invention, the thermosetting composition and the reinforcing fiber base material are drawn into a thermoforming mold, and the thermosetting composition is cured in the thermoforming mold so as to have a predetermined shape. A method for producing a pultruded molded body, in which the molded body is drawn from a thermoforming mold; a first reinforced fiber base material composed of carbon fibers in which carbon fibers are oriented in MD as the reinforced fiber base material; and MD As long as it is a method using a plurality of carbon fibers oriented in an oblique direction and at least one inorganic fiber yarn oriented in MD and a second reinforcing fiber base material bound by stitching yarn, The method for manufacturing the pultruded article 10 using the manufacturing apparatus 50 of the illustrated example is not limited.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. “Parts” indicates “parts by mass” unless otherwise specified.
Examples 1 and 2 are examples, and example 3 is a comparative example.

<Materials used>
(First reinforcing fiber substrate)
A first reinforcing fiber substrate 20 shown in FIG. 3 was prepared. As the MD-oriented carbon fiber sheet 24, carbon fiber tow (manufactured by Toray Industries, Inc., T700SC-24K-60E, number of filaments: 24000, fineness: 16500 dtex, tensile strength: 4900 MPa, tensile elastic modulus: 230 GPa, elongation: 2.1 %, Density: 18 dg / cm ³ ) and 44 bundles of MDs (number of filaments: 1,056,000) were used.

(Second reinforcing fiber substrate)
A second reinforcing fiber substrate 30 (manufactured by SHINDO, basis weight: 286 g / m ² , width: 100 mm) shown in FIGS. 4 and 5 was prepared. As the first obliquely oriented carbon fiber sheet 34, a plurality of carbon fiber tows (T300 equivalent manufactured by Toray Industries, Inc.) aligned at + 45 ° with respect to MD was used. As the second obliquely oriented carbon fiber sheet 36, a plurality of carbon fiber tows (T300 equivalent manufactured by Toray Industries, Inc.) aligned at −45 ° with respect to MD was used. As the inorganic fiber yarn 38, a glass fiber yarn was used. Polyester yarn was used as the first stitching yarn 40 and the second stitching yarn 42. The interval between the first stitching yarn 40 and the second stitching yarn 42 was 5 mm.

(Other reinforcing fiber base materials)
Carbon fiber fabric: SIGMATEX UK LTD. Manufactured by DMC2831524 (using carbon fiber tow (T700SC-24K-60E), fiber orientation ± 45 °, basis weight 300 g / m ² , width: 100 mm).

(Thermosetting composition containing epoxy resin)
According to the formulation shown in Table 1, epoxy resin, acid anhydride, curing accelerator, and internal mold release agent were mixed to prepare liquid thermosetting compositions (1) to (2) at 25 °. .

Each material shown in Table 1 is as follows.
Epoxy resin 1: bisphenol A type epoxy resin (manufactured by Olin Corporation, AIRSTONE (registered trademark) 550E Epoxy Resin).
Epoxy resin 2: bisphenol A type epoxy resin (manufactured by Olin Corporation, DER383).
Curing agent 1: Mixture such as methyltetrahydrophthalic anhydride (manufactured by Olin Corporation, AIRSTONE (registered trademark) 555H Epoxy Hardener).
Curing agent 2: methyltetrahydrophthalic anhydride (manufactured by Hitachi Chemical Co., Ltd., HN2200).
Curing accelerator: 2-ethyl-4-methylimidazole (manufactured by Shikoku Kasei Co., Ltd., Curazole 2E4MZ).
Internal mold release agent: Mixture of organic acid derivatives and the like (Axel Plastics Research Laboratories, Inc., MoldWiz (registered trademark) INT-1888LE).

(Thermosetting composition containing vinyl ester resin)
Heat containing vinyl ester resin (manufactured by Iupika Japan, 8250H), organic peroxide (manufactured by Nippon Oil & Fats, Nyper (registered trademark) NS), mold release agent (manufactured by Axel Plastics Research Laboratories, Inc., INT-PUL24) A curable composition (3) was prepared.

<Example 1>
Using the manufacturing apparatus 50 having the configuration shown in FIG.
In a state where the first reinforcing fiber base material 20 is pulled upward from the thermosetting composition (1) in the resin tank 54, the thermosetting composition is applied to the first reinforcing fiber base material 20 from the coating device 66. (3) was applied. The first reinforcing fiber substrate 20 to which the thermosetting composition (3) is applied is taken together with the two second reinforcing fiber substrates 30 in a relaxed state by a drawing machine 56, so that the heat forming metal mold is used. It was drawn into the space S (cross-sectional shape: C shape) of the mold 52. The thermosetting composition (3) was cured in the thermoforming mold 52 to form a molded body, and this was drawn from the thermoforming mold 52 by a drawing machine 56. After the tension applied to the reinforcing fiber base is stabilized, the first reinforcing fiber base 20 is simultaneously immersed in the resin tank 54 in which the thermosetting composition (1) is stored. In addition, the application of the thermosetting composition (3) from the coating device 66 was stopped.

  The first reinforcing fiber base material 20 is submerged in the resin tank 54 in which the thermosetting composition (1) is stored for 1.5 to 2.5 minutes, and the first reinforcing fiber base material 20 is thermosetting. The composition was impregnated. The first reinforcing fiber base material 20 impregnated with the thermosetting composition (1) is pulled up from the resin tank 54 and taken out by the drawing machine 56 to be drawn into the space S (cross-sectional shape: C shape) of the thermoforming mold 52. It is. At the same time, the two second reinforcing fiber substrates 30 supplied in a relaxed state from the first supply roll 62 and the second supply roll 64 so as to sandwich the first reinforcing fiber substrate 20, It was drawn into the space S of the heating mold 52 by taking it out by the drawing machine 56. The thermosetting composition is heat-cured at 150 ° C. for 2 to 3 minutes in the thermoforming mold 52 to obtain a molded body, which is pulled out by the drawing machine 56 from the thermoforming mold 52, and the channel-shaped pultruded molded body 10 ( Width: 50 mm, height: 34.5 mm, thickness: 3.5 mm). The pultruded body 10 was subjected to after-curing at 200 ° C. for 6 hours offline.

<Example 2>
A pultruded article was obtained in the same manner as in Example 1 except that the thermosetting composition (1) was changed to the thermosetting composition (2).

<Example 3>
A pultruded article in the same manner as in Example 1 except that instead of the second reinforcing fiber substrate 30, a carbon fiber woven fabric that does not have MD-oriented glass fibers and is not bound by stitching yarns is used. Got.

<Result>
At the time of producing the pultruded bodies of Examples 1 and 2, both side edges of the second reinforcing fiber base material 30 do not approach the center, and the disorder of the carbon fibers oriented obliquely with respect to the MD is suppressed. It was done. Moreover, since the pultruded body of Examples 1-2 did not contain a mat component, it had sufficient strength.
At the time of manufacturing the pultruded article of Example 3, the both side edges of the carbon fiber fabric were shifted to the center, and the disturbance of the carbon fibers oriented obliquely with respect to the MD occurred.

  The pultruded article of the present invention is useful as various pultruded articles because the disorder of carbon fibers oriented in an oblique direction with respect to MD is suppressed, the strength is uniform, and the strength per unit mass is sufficiently high. It is.

10 pultruded body,
12 first surface layer,
14 Second surface layer,
16 middle class,
20 first reinforcing fiber substrate,
22 carbon fiber,
24 MD oriented carbon fiber sheet,
30 second reinforcing fiber substrate,
32 obliquely oriented carbon fiber,
34 a first obliquely oriented carbon fiber sheet,
36 a second obliquely oriented carbon fiber sheet,
38 Inorganic fiber yarns,
40 First stitching yarn,
42 second stitching yarn,
42a upper thread,
42b lower thread,
50 production equipment,
52 thermoforming mold,
54 Resin tank,
56 drawing machine,
58 cutting machine,
60 guide rolls,
62 first supply roll,
64 second supply roll 64,
66 coating device,
A first main surface,
B second main surface,
S space.

Claims (5)

It is a pultruded article containing a matrix resin that is a cured product of a thermosetting composition and a reinforcing fiber base,
As the reinforcing fiber base, a first reinforcing fiber base composed of a plurality of carbon fibers oriented in MD, a plurality of carbon fibers oriented in an oblique direction with respect to MD, and at least one strip of inorganic fibers oriented in MD A pultruded article including a second reinforcing fiber base material in which the yarn is bound by stitching yarn.   The pultruded article according to claim 1, wherein the matrix resin is a cured product of a thermosetting composition containing an epoxy resin. The thermosetting composition and the reinforcing fiber base material are drawn into a thermoforming mold, and the thermosetting composition is cured in the thermoforming mold to form a molded body having a predetermined shape. It is a method for producing a pultruded molded body by pulling out the molded body,
As the reinforcing fiber base, a first reinforcing fiber base made of carbon fiber tows in which carbon fibers are oriented in MD, a plurality of carbon fibers oriented in an oblique direction with respect to MD, and at least one strip oriented in MD A method for producing a pultruded article using a second reinforcing fiber base material in which inorganic fiber yarns are bound by stitching yarns.   The tension applied to the second reinforcing fiber base drawn into the thermoforming mold is made lower than the tension applied to the first reinforcing fiber base drawn into the thermoforming mold. Method for producing a pultruded article.   Starting the production of a pultruded article using a thermosetting composition containing a vinyl ester resin as the thermosetting composition, and then switching the thermosetting composition to a thermosetting composition containing an epoxy resin. The method for producing a pultruded article according to claim 3 or 4.

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