TW201908551A - Core-sheath composite yarn for fiber reinforced resin and fiber reinforced resin using the same - Google Patents

Abstract

A sheath-core composite yarn 1 for fiber-reinforced resins, which comprises a core yarn 2 and covering yarns 3, 4, and wherein: the core yarn is a superfiber yarn that has a strength of 14 cN/decitex or more and an elastic modulus of 300 cN/decitex or more; each of the covering yarns 3, 4 is at least one yarn selected from among a carbon fiber yarn, a glass fiber yarn, an aramid fiber yarn and a high-strength polyethylene fiber yarn; and the covering yarns 3, 4 are composed of at least two yarns which have different winding directions and cover the circumference of the core yarn 1. A fiber-reinforced resin according to the present invention is obtained by integrally molding the sheath-core composite yarn 1 with a matrix resin or by integrally molding a fiber structure that contains the sheath-core composite yarn 1 with a matrix resin. Consequently, the present invention provides: a sheath-core composite yarn for fiber-reinforced resins, which has high impact energy absorption properties; and a fiber-reinforced resin which uses this sheath-core composite yarn for fiber-reinforced resins.

Description

Core-sheath composite yarn for fiber-reinforced resin and fiber-reinforced resin using the same

The present invention relates to a core-sheath composite yarn for fiber-reinforced resin having impact energy absorption and a fiber-reinforced resin using the same.

In recent years, fiber-reinforced plastic (FRP), which uses high-strength fibers to reinforce thermosetting plastic materials, has the characteristics of light weight, high strength, and high modulus of elasticity. It is expected to be a substitute for iron or aluminum. Currently, its characteristics are being used as materials for aircraft or automobiles. Different from the above, there are SMC (Sheet Molding Compound) as a base material, and there are also those formed by putting the SMC in a mold and heating and pressing. The SMC is more concerned with lightweight than the purpose of replacing metal. The polyester resin is impregnated into a fiber mat material in which glass fiber bundles cut to a length of about 5 cm are randomly arranged so as to have a fixed basis weight. As an example, there is a bathtub. In this case, since it is a discontinuous fiber, it is characterized by free shape. These FRPs utilize characteristics such as high strength, high modulus of elasticity, and lightness, but there are problems such as brittle failure when the action allows an excessive load above. In contrast to this, there are ductile deformation regions in the metal, and there are deformation regions before brittle failure. In order to solve the above-mentioned problem of impact energy, Patent Document 1 proposes to make the extension of the inner layer and the outer layer of the FRP have a specific relationship. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 09-226039

[Problems to be solved by the invention]

However, the above-mentioned prior art is still insufficient in solving the impact energy problem, and needs to be further improved.

The present invention provides a core-sheath composite yarn for fiber-reinforced resin with high impact energy absorption and a fiber-reinforced resin using the same in order to solve the aforementioned problems. [Technical means to solve the problem]

The core-sheath composite yarn of the present invention is characterized in that it includes a core wire and a covered wire. The core wire is a super fiber yarn having a strength of 14 cN/decitex or more and an elastic modulus of 300 cN/decitex or more. The coated wire is At least one selected from carbon fiber yarns, glass fiber yarns, aromatic polyamide fiber yarns, and high-strength polyethylene fiber yarns. The coating yarn is wound around and covering the core yarn with at least one long fiber yarn.

The fiber-reinforced resin of the present invention is characterized in that it is a fiber-reinforced resin containing the core-sheath composite yarn, by integrally molding the core-sheath composite yarn and the matrix resin, or by forming a fiber structure including the core-sheath composite yarn The matrix resin is integrally formed so as to have impact energy absorption. [Effect of invention]

The core-sheath composite wire of the present invention is a core-sheath composite wire comprising a core wire and a coated wire and used in an impact energy absorbing material. The above-mentioned core wire is super with strength: 14 cN/decitex or more and elastic modulus: 300 cN/decitex or more Fiber yarn, the coating yarn is at least one selected from carbon fiber yarn, glass fiber yarn, aromatic polyamide fiber yarn and high-strength polyethylene fiber yarn, if the coating yarn is wound with at least one long fiber yarn When the core wire is coated and integrally formed with the matrix resin to become a reinforced base material, even if the core wire is broken when impact energy is applied, the sheath wire can be extended and deformed by deforming like a coil, thereby providing impact energy Core-sheath composite yarn for fiber-reinforced resin with high absorption and fiber-reinforced resin using the same.

The present inventors believe that it is preferable to provide a structure in which the reinforcing fibers constituting FRP can absorb energy even after breaking. It is also believed that if the spiral composite wire can be stretched inside the FRP without breaking to absorb energy, then by attaching the FRP to the brittle structure, the brittle failure due to impact energy can be prevented. For this reason, not only must it be used linearly like the previous FRP reinforced fiber, but it must also be able to bend. In order to realize such a structure, a structure in which high-strength fibers are wound in a coil shape around a core wire is assumed. As a means of realizing this structure, some kind of wire-covering machine has been used since then. The structure of the silk is shown in Fig. 1. It is considered that if a flat structured wire (core-sheath composite wire) using such a structure is used as a reinforcing substrate, even if the core wire breaks when impact energy is applied, the sheath wire can be extended and deformed like a coil. In order to achieve such deformation, it is also effective to use a deformable elastic resin that will not be brittlely damaged by impact energy in the matrix resin. In the case of a non-elastic resin, it is believed that the sheath wire will be damaged together when the brittleness of the resin is destroyed, and the effect of coil extension and the like cannot be obtained. The core wire can be selected according to the purpose. That is, in order to effectively absorb the impact energy before the impact load reaches the maximum, the organic fiber may be selected. The core wire comes into play before the maximum load. In contrast, in order to obtain only the absorption of impact energy when cracking after the maximum load progresses, the core wire may be a wire with low strength. For example, general chemical fibers such as nylon, polyester and polypropylene. In addition, when using such silk to form a substrate, the woven fabric structure is preferable. The reason is that the impact energy can be absorbed by the woven fabric structure.

The core yarn of the core-sheath composite yarn of the present invention is a super fiber yarn with a strength of 14 cN/decitex or more and an elastic modulus of 300 cN/decitex or more. More preferably, it is a super fiber yarn with a strength of 18 cN/decitex or more and an elastic modulus of 380 cN/decitex or more. In addition, the coated yarn is a carbon fiber yarn, a glass fiber yarn, an aromatic polyamide fiber yarn, or a high-strength polyethylene fiber yarn, and at least one wire is wound around the coated core yarn. Furthermore, if the coating is wound by one coating wire, the composite yarn is twisted and the operability is lowered. Therefore, it is preferable to coat the core wire with at least two wires having different winding directions. This coated yarn is also called W-coated yarn. The preferred fineness of the core yarn is 10~2000 tex. In addition, considering the windability, that is, the ease of winding in a coil shape, the preferred fineness of the covered yarn is 5 to 100 tex.

The super fiber yarn of the core yarn is preferably selected from aromatic polyamide fibers (strength of para-system aromatic polyamide fibers: 19~25 cN/decitex, elastic modulus: 380~980 cN/decitex), Polyarylate fiber (strength: 18~22 cN/decitex, elastic modulus: 600~741 cN/decitex), poly-p-phenylene benzotriazole (PBO) fiber (strength: 37 cN/decitex, elastic Modulus: 1060~2200 cN/decitex), polypara-phenylene benzodithiazole (PBZT) fiber, polyethylene fiber (strength: 26~40 cN/decitex, elastic modulus: 883~1413 cN/decitex), At least one fiber filament of polyetheretherketone fiber and polyvinyl alcohol fiber (source of strength and elastic modulus: "Encyclopedia of Fibers", page 522, Maruzen, issued on March 25, 2002). In particular, aromatic polyamide fibers have high strength and modulus of elasticity and good adhesion to matrix resins, so they are preferred.

The above-mentioned core wire may also be set to one or plural. In order to maintain the required thickness, the core wire is preferably plural. The core wire can also straighten the plural roots or twist the plural roots.

A protective wire may be further provided outside the coated wire. The protective yarn may be at least one kind of fiber yarn selected from the group consisting of polyester yarn, nylon yarn, polypropylene yarn, and the above-mentioned super fiber yarn, or it may be covered by a so-called slit yarn. The applied form is usually winding or straightening, but is not particularly limited. The coating yarn on the outer side of the core-sheath composite yarn is carbon fiber yarn, glass fiber yarn, aromatic polyamide fiber yarn or high-strength polyethylene fiber yarn. Therefore, when the reed or the like passes through the woven fabric device, there are also friction In the case of wire breakage, the above protection wire can be used to prevent breakage.

The number of windings of the coated wire relative to the above-mentioned core wire, that is, the number of windings per one of the coated wires is preferably 100 to 1500 turns/meter. In this way, better strength and impact energy absorption can be achieved.

The fiber-reinforced resin having impact energy absorbing material properties of the present invention is formed by integrally molding the core-sheath composite yarn and the matrix resin, or integrally molding the fiber structure including the core-sheath composite yarn and the matrix resin. Furthermore, the material of the present invention can also be attached to one or both sides of a structure formed of concrete, plastic, metal, etc. The core-sheath composite yarn and the matrix resin are integrally formed, and can be used as a thick wire reinforced resin for golf clubs or fishing rods. The fiber structure including the core-sheath composite yarn and the matrix resin can be integrally formed and applied to the planar reinforcing resin. The above-mentioned fiber structure is preferably a woven fabric made of a curtain-shaped base material in which the core-sheath composite yarn is aligned in one direction, and the core-sheath composite yarn is selected from at least one kind of weft yarn and warp yarn, including At least one of a knitted fabric of a core-sheath composite yarn, a composition containing the above-mentioned core-sheath composite yarn, and a multiaxial insertion longitudinal knitting including the above-mentioned core-sheath composite yarn. As an example, the core-sheath composite yarn is at least one kind of yarn selected from weft yarns and warp yarns of a woven fabric, and the woven fabric and the matrix resin are integrally formed. The reason for using the woven fabric is that the dimensional stability in the vertical and horizontal directions is better. If the core-sheath composite yarn is used for the weft or warp of the woven fabric, the impact energy in this direction can be absorbed. When used in both weft and warp yarns, it can absorb impact energy in longitudinal and transverse directions.

The matrix resin may be any resin as long as it is a resin generally used in FRP, and for example, there is an epoxy resin. Among the epoxy resins, elastic resins are preferred, and rubber-modified epoxy resins with flexibility (for example, DIC Corporation, trade name "TSR-930"), highly durable, soft and tough epoxy resins are more preferred. For example, manufactured by DIC Corporation, trade name "EXA-4816").

The following is a diagram. In the following drawings, the same symbols indicate the same. FIG. 1 is a schematic perspective view of a core-sheath composite yarn 1 according to an embodiment of the present invention. The core-sheath composite wire 1 is composed of a core wire 2 and coated wires 3 and 4. The core wire 2 is a super fiber yarn with a strength of 14 cN/decitex or more and an elastic modulus of 300 cN/decitex or more. The coated wires 3 and 4 are carbon fiber wires or glass fiber wires. The coated wires 3 and 4 have different winding directions. At least two wires are coated around the core wire 2. The degree of coating is preferably such that the core wire 2 cannot be seen by the covering wires 3 and 4.

FIG. 2 is also a schematic perspective view of the core-sheath composite yarn used in the weft woven fabric 5. The woven fabric is composed of warp yarns 6 and weft yarns 7, and the core-sheath composite yarn is arranged on the weft yarns 7. The warp yarn 6 is a synthetic polyester yarn such as ordinary polyester yarn or nylon yarn.

FIG. 3A is also a schematic perspective view of the laminated multiple woven fabric 5 and FIG. 3B is also a schematic perspective view of the fiber-reinforced resin sheet in which the laminated multiple woven fabric 5 and the matrix resin 8 are integrated. In this example, the matrix resin 8 uses an elastic resin.

Fig. 15 is a schematic perspective view of a protection wire applied to a core-sheath composite wire of another embodiment of the present invention. The core-sheath composite wire 1 of FIG. 1 is further wound with a protective wire 18 and/or a protective wire 19. 20 is a core-sheath composite wire wound with a protective wire.

FIG. 4 is also a schematic illustration of a breakdown impact test apparatus 10 for measuring the absorption of impact energy. This device places the sample 12 on the base 9 and then mounts the holder 11 to fix the sample 12 so that the load unit 13 with the impactor 14 dropped from above to apply an impact to the sample 12, according to the impact load and displacement analysis The amount of impact energy absorbed. This test method is used as a test method for measuring the absorption amount of impact energy, and complies with the JIS K7211-2 rigid plastics impact impact test method. (1) Use breakdown energy (J) as the energy absorption value of the material. (2) Test machine: IM10T-20HV manufactured by Imatek (3) Sample size: 60 mm×60 mm (4) Impactor: Φ10 mm semi-spherical ball (5) Height: 1 m (6) Impact speed: 4.4 m/ sec (7) Impact energy: 91 J Under the above conditions, the sample in this case can be penetrated.

Fig. 5 is also an explanatory diagram of a graph of measurement data of breakdown impact test. In the impact load-shift graph of Fig. 5, the breakdown energy is the area from the rising line of the graph to 1/2 of the maximum load of the falling line. Let the area up to the maximum load be energy 15 up to the maximum load. The area of displacement from the maximum load to 1/2 of the maximum load is set as the crack progress energy 16. The ratio (%) of crack progress energy (16) to breakdown energy (15+16) was compared. The details are described in Examples and Comparative Examples. [Example]

The present invention is specifically described below using examples. Furthermore, the present invention is not limited to the following examples. (Example 1) Using para-type aromatic polyamide fiber yarn (made by DU PONT-TORAY Co., Ltd., trade name "KEVLAR") with a fineness of 167 tex as the core yarn, and carbon fiber with a fineness of 66 tex as the lower wire coating yarn The wire is wound around the core wire in the Z direction at a rate of 600 turns/meter, and then a 66 tex carbon fiber wire as the upper wire coating wire is wound around the core wire in the S direction at a rate of 600 turns/meter. Winding to obtain a core-sheath composite yarn with a total fineness of 378.6 tex (Figure 1). The core-sheath composite yarn was set as weft yarn, and polyester (PET) 333 tex multifilament yarn was used as warp yarn to obtain a plain weave fabric with a mass per unit area (weight per unit area) of 776.5 g/m ² (Figure 2) . The woven fabric has a length of 40 cm and a width of 20 cm. Four pieces of this woven fabric were orthogonally laminated in different directions so as to become 0°/90°/90°/0° based on the core-sheath composite yarn (FIG. 3A ). Then, using a rubber-modified epoxy resin (manufactured by DIC Corporation, trade name "TSR-930") as the main agent, and using a trade name "WH-420" manufactured by DIC Corporation as the curing agent, a molded plate was produced (Figure 3B and below) Also known as "CF-AF-930"). The thickness of the central part of the obtained shaped plate was 6.2 mm, and the mass per unit area (weight per unit area) was 6939.3 g/m ² . When the breakdown impact test shown in FIG. 4 is performed on the center portion of the obtained formed plate, the following data is obtained as shown in the graph of FIG. 6. (1) Breakdown energy: 28.88 J (2) Breakdown displacement: 13.47 mm (3) Peak energy: 8.27 J (4) Peak displacement: 5.09 mm (5) Crack progress energy: 20.61 J (6)[ Crack progress energy/breakdown energy]×100=71.4%

(Example 2) Using para-type aromatic polyamide fiber yarn (manufactured by DU PONT-TORAY Co., Ltd., trade name "KEVLAR") with a fineness of 167 tex as the core yarn, and a glass with a fineness of 33 tex as the lower wire coating yarn The fiber wire is wound around the core wire in the Z direction at a ratio of 800 turns/meter, and then the glass fiber wire with a fineness of 66 tex as the upper wire coating wire is wound around the core wire at 800 turns/meter in the S direction It was wound in proportion to obtain a core-sheath composite yarn with a total fineness of 288.6 tex (Figure 1). The core-sheath composite yarn was set as weft yarn, and polyester (PET) 333 tex multifilament was used as warp yarn to obtain a plain weave fabric with a mass per unit area (weight per unit area) of 999.6 g/m ² (Figure 2) . The woven fabric was laminated in the same manner as in Example 1, using a rubber-modified epoxy resin (manufactured by DIC Corporation, trade name "TSR-930") as the main agent, and the hardener used the trade name "WH-" manufactured by DIC Company. 420" to make a shaped plate (Figure 3B, hereinafter also referred to as "GF-AF-930"). The thickness of the central part of the obtained shaped plate was 7.0 mm, and the mass per unit area (weight per unit area) was 8301.9 g/m ² . When the breakdown impact test shown in FIG. 4 is performed on the center portion of the obtained formed plate, the following data is obtained as shown in the graph of FIG. 7. (1) Breakdown energy: 45.64 J (2) Breakdown displacement: 14.93 mm (3) Peak energy: 20.14 J (4) Peak displacement: 6.87 mm (5) Crack progress energy: 25.50 J (6)[ Crack progress energy/breakdown energy]×100=55.90%

(Example 3) The epoxy resin manufactured by DIC Corporation as the matrix resin and the trade name "EXA-4816" as the main agent, and the trade name "WH-619" manufactured by DIC Corporation as the curing agent, and otherwise In Example 2, a shaped plate (Fig. 3B, hereinafter also referred to as "GF-AF-4816") was produced in the same manner. The thickness of the central part of the obtained shaped plate was 7.7 mm, and the mass per unit area (weight per unit area) was 8780 g/m ² . When the breakdown impact test shown in FIG. 4 is performed on the center portion of the obtained formed plate, the following data is obtained as shown in the graph of FIG. 8. (1) Breakdown energy: 46.95 J (2) Breakdown displacement: 8.61 mm (3) Peak energy: 27.08 J (4) Peak displacement: 5.19 mm (5) Crack progress energy: 18.87 J (6)[ Crack development energy/breakdown energy]×100=42.30% The above information is summarized and shown in Table 1.

[Table 1]

(Comparative Examples 1 to 5) Comparative Example 1 shows the measurement data of the breakdown impact test of stainless steel SUS304 with a thickness of 0.5 mm in FIG. 9 and summarizes the data in Table 2. Comparative Example 2 shows the measurement data of the breakdown impact test of aluminum A5052 with a thickness of 1.5 mm in FIG. 10, and summarizes the data in Table 2. In Comparative Example 3, a graph of measurement data of the breakdown impact test of a commercially available glass fiber woven fabric reinforced epoxy resin molded product (GFRP) with a thickness of 2.5 mm is shown in FIG. 11, and the data is summarized in Table 2. In Comparative Example 4, a reinforced epoxy resin molded article (CF-AFRP) with a thickness of 3.3 mm and a commercially available carbon fiber woven fabric placed in the center and laminated with a para-type aromatic polyamide woven fabric on both surfaces was laminated. The graph of the measurement data of the breakdown impact test is shown in FIG. 12 and the data is summarized in Table 2. In Comparative Example 5, a reinforced epoxy resin molded article (GF-AFRP) with a thickness of 4.4 mm and a commercially-available glass fiber woven fabric placed in the center and sandwiched and laminated with a para-type aromatic polyamide woven fabric on both surfaces was laminated. The graph of the measurement data of the breakdown impact test is shown in FIG. 13 and the data is summarized in Table 2.

[Table 2]

FIG. 14 is a comparison chart of the crack progress energy of the breakdown impact test of each example of the present invention and each comparative example. According to FIG. 14, it can be confirmed that the energy absorption ratio after the start of the destruction of each example of the present invention is higher than that of the comparative example. [Industry availability]

The core-sheath composite yarn for fiber-reinforced resin of the present invention and the fiber-reinforced resin using it have a high energy absorption ratio after the start of destruction, so they can be applied to impact absorbers for automobiles or vehicles, impact mitigation devices for highways, and various explosion-proof Film etc.

1‧‧‧core sheath composite wire

2‧‧‧core wire

3. 4‧‧‧ coated wire

5‧‧‧ Woven fabric

6‧‧‧Warp

7‧‧‧Weft

8‧‧‧ matrix resin

9‧‧‧Abutment

10‧‧‧ Breakdown impact test device

11‧‧‧Retainer

12‧‧‧Sample

13‧‧‧ Load unit

14‧‧‧ Impactor

15‧‧‧The area up to the maximum load is the energy up to the maximum load

16‧‧‧Crack progress energy from maximum load to 1/2 of maximum load

18.19‧‧‧Protection wire

20‧‧‧Core-sheath composite wire wound with protective wire

FIG. 1 is a schematic perspective view of a core-sheath composite yarn according to an embodiment of the present invention. Fig. 2 is also a schematic perspective view of a core-sheath composite yarn used in a weft woven fabric. FIG. 3A is also a schematic perspective view of the laminated multiple-piece woven fabric, and FIG. 3B is also a schematic perspective view of the fiber-reinforced resin sheet in which the laminated multiple-piece woven fabric and the matrix resin are integrated. FIG. 4 is also a schematic illustration of a breakdown impact test device that measures the absorption of impact energy. Fig. 5 is also an explanatory diagram of a graph of measurement data of breakdown impact test. 6 is a graph of measurement data of a breakdown impact test of Example 1 of the present invention. 7 is a graph of measurement data of a breakdown impact test of Example 2 of the present invention. 8 is a graph of measurement data of a breakdown impact test of Example 3 of the present invention. 9 is a graph of measurement data of the breakdown impact test of Comparative Example 1. FIG. FIG. 10 is a graph of measurement data of breakdown impact test of Comparative Example 2. FIG. FIG. 11 is a graph of measurement data of breakdown impact test of Comparative Example 3. FIG. FIG. 12 is a graph of measurement data of breakdown impact test of Comparative Example 4. FIG. 13 is a graph of the measurement data of the breakdown impact test of Comparative Example 5. FIG. FIG. 14 is a comparison chart of the crack progress energy of the breakdown impact test of each example of the present invention and each comparative example. Fig. 15 is a schematic perspective view of a protection wire applied to a core-sheath composite wire of another embodiment of the present invention.

Claims (8)

A core-sheath composite yarn for fiber-reinforced resin, which comprises a core wire and a covering wire, and the above-mentioned core wire is a super fiber yarn having a strength of 14 cN/decitex or more and an elastic modulus of 300 cN/decitex or more. From at least one of carbon fiber yarn, glass fiber yarn, aromatic polyamide fiber yarn, and high-strength polyethylene fiber yarn, the coating yarn is wound around the core yarn with at least one long fiber yarn. The core-sheath composite yarn for fiber-reinforced resin according to claim 1, wherein the coated yarn is wound around the coated core yarn with at least two yarns having different winding directions. The core-sheath composite yarn for fiber-reinforced resin according to claim 1, wherein the super fiber yarn is selected from the group consisting of aromatic polyamide fiber, polyarylate fiber, and poly-p-phenylene benzotriazole (PBO) ) At least one fiber yarn of fiber, poly-p-phenylene benzodithiazole (PBZT) fiber, polyethylene fiber, polyether ether ketone fiber and polyvinyl alcohol fiber. The core-sheath composite yarn for fiber-reinforced resin according to claim 1, wherein the core yarn is one or plural. The core-sheath composite yarn for fiber-reinforced resin according to claim 1, wherein a protective yarn is further twisted outside the coated yarn, and the protective yarn is selected from polyester yarn, nylon yarn, polypropylene yarn and the super At least one fiber filament in the fiber filament. The core-sheath composite yarn for fiber-reinforced resin according to claim 1, wherein the number of windings of each coated yarn relative to the core yarn is 100 to 1500 turns/meter. A fiber-reinforced resin comprising a fiber-reinforced resin of the core-sheath composite yarn according to any one of claims 1 to 6, and by integrally forming the core-sheath composite yarn and a matrix resin, or comprising the core-sheath The fiber structure of the composite yarn is integrally formed with the matrix resin, thereby having impact energy absorption. The fiber-reinforced resin according to claim 7, wherein the fiber structure is selected from curtain-shaped substrates in which the core-sheath composite yarn is aligned in one direction, and the core-sheath composite yarn is selected from weft yarns and warp yarns At least one of a woven fabric of at least one kind of silk, a knitted fabric comprising the above-mentioned core-sheath composite yarn, a composition comprising the above-mentioned core-sheath composite yarn, and a multi-axis insertion longitudinal knitted fabric comprising the above-mentioned core-sheath composite yarn.