JP7686658B2 - Mesh-like fiber-reinforced composite material, mesh-like knitted structure, material for molding mesh-like fiber-reinforced composite material, and mesh-like fiber-reinforced composite molded body - Google Patents

Description

The present invention relates to a mesh-like fiber-reinforced composite material which is a composite material of a thermosetting or thermoplastic resin and reinforcing fibers, and which is suitable for use as a filter, cover, reinforcing member, and particularly as a protector such as a protective hat, and as an interior and exterior member for a prosthesis (prosthetic leg, prosthetic hand) because it is a mesh-like composite material having a high opening ratio, light weight, high strength, and high impact resistance. The present invention also relates to a mesh-like knitted structure and a mesh-like fiber-reinforced composite molding material used for the mesh-like fiber-reinforced composite material, and further relates to a mesh-like fiber-reinforced composite molded product obtained by shaping the mesh-like fiber-reinforced composite molding material.

Conventionally, most mesh materials have been made of resin or metal. However, resin is lightweight but lacks strength, while metal is strong but heavy.

This problem is particularly significant in protective gear worn for body protection, and in recent years, there have been cases where fiber-reinforced plastic members have been used. For example, caps with inner linings have been proposed and are commercially available, and can be worn as uniform caps by security guards, station staff, police officers, etc. to protect the head from unexpected falling objects or external impacts, and can also be worn as sports caps by the general public, including children and the elderly, to protect the head.

Patent Document 1 describes a hat 100 with a protective inner as shown in Figs. 7(a) and (b) attached to the present application, and the hat 100 includes a cloth cap-shaped hat body (crown) 102 and a brim 103, and a protective inner 110 is provided inside the hat body 102. As shown in the figure, the protective inner 110 is fitted to the inside of the hat body 102 and has a bowl shape curved into a substantially spherical shape so that it can fit the head of a person when worn by the person, and is composed of an inner body 111 that forms the basic structure of the inner and is made of a fiber reinforced plastic material (FRP) and has a curved shape similar to the shape of the top region of the hat body 102, a cushion member 112 arranged inside the inner body 111, and a cover sheet 113 arranged to cover the inner body 111 and the cushion member 112.

The protective inner hat 100 described in the above-mentioned Patent Document 1 is lightweight and has good breathability, and is also excellent in impact resistance and wearability.

However, in the protective inner hat 100 described in the above Patent Document 1, the inner body 111 forming the basic structure of the inner is made of a fiber reinforced plastic material (FRP) in which unidirectional or woven reinforced fibers are impregnated with a matrix resin, which is a thermosetting resin or a thermoplastic resin, and hardened. Therefore, although it is lightweight and high strength, it may feel stuffy when worn for a long time, and it has been found that further improvement in terms of breathability is desired. Also, as described above, the inner body 111 is made into a bowl shape curved into an approximately spherical shape so as to fit a human head, and is made of a fiber reinforced plastic material (FRP) in which a unidirectional or woven reinforced fiber sheet is impregnated with resin and hardened, but the unidirectional or woven reinforced fiber sheet before resin impregnation has problems in terms of stretchability and drapeability, and further improvement in terms of moldability (shapeability) is desired.

Patent Document 2 discloses a sheet-shaped carbon fiber knitted fabric made by using carbon fibers, and describes that the sheet-shaped carbon fiber knitted fabric has excellent stretchability and drapeability.

The present inventors have focused on the excellent stretchability and drapeability of the sheet-like knitted carbon fiber fabric described in Patent Document 2, and have discovered that a mesh-like reinforced fiber composite material produced by impregnating a sheet-like carbon fiber woven fabric with a predetermined amount of resin and curing it while retaining a predetermined opening ratio of the sheet-like knitted carbon fiber fabric provides excellent breathability and prevents stuffiness, and is also lightweight and strong, when used as an interior material (inner material) for hats, various protectors, and prosthetic limbs (prosthetic legs, prosthetic hands), or as a material for constituting the basic structure of an exterior material (frame), etc.

Therefore, the present inventors have developed a method for manufacturing a semiconductor device, as described in Patent Document 3 and illustrated in FIGS. 8(a) and 8(b) attached to the present application,
(a) A mesh-like knitted structure 1A having gaps G formed by a plurality of vertical knitted structures 20 produced by knitting a chain stitch yarn 2 in a loop shape while continuously forming chain stitches 2A in the vertical direction, and an insertion yarn 3 that is inserted laterally into the vertical knitted structures 20 and binds adjacent knitted structures 20 together;
(b) A mesh-shaped fiber-reinforced composite material 10A formed into a curved shape in which only the knitted structure 20 (chain knit yarn 2) and the insertion yarn 3 in the mesh-shaped knitted structure 1A are impregnated with resin R and hardened,
(c) at least a part of the chain stitch yarn 2 and the insertion yarn 3 is a carbon fiber strand made of carbon fiber;
(d) the opening ratio of the mesh-like knitted structure 1A is 20 to 60%;
A mesh-shaped fiber-reinforced composite material 10A having voids G of the above structure has been proposed.

The mesh-like knitted structure 1A used in the mesh-like fiber-reinforced composite material 10A described in Patent Document 3 has excellent elasticity and drapeability and excellent moldability (shapeability) into curved shapes because the reinforcing fibers used are not straight but have a knitted structure. Moreover, because it has voids G, it has excellent breathability and can prevent stuffiness, is lightweight and has sufficient strength, and has the characteristics of being able to form the basic structure of interior materials (innerwear) for hats, various types of protectors, and prosthetic limbs (prosthetic legs, prosthetic hands), or exterior materials (frames).

Utility Model Registration No. 3187008 Patent No. 4822528 Patent No. 6362454

The mesh-like knitted structure 1A used in the mesh-like fiber-reinforced composite material 10A described in the above Patent Document 3 is excellent in stretchability and drapeability, and excellent in formability into shapes having curved surfaces. However, even if carbon fiber strands made of carbon fibers are used for at least some of the chain stitch yarns 2 and the insertion yarns 3, the mesh-like fiber-reinforced composite material 10A impregnated with resin and hardened is easily broken from the resin by external force, and it has been found that when used in a headgear such as a helmet, for example, when stress (impact) is applied by a dropped object, bending (distortion) is easily generated in the part to which stress is applied, and mechanical strength such as tensile strength and bending elasticity is also reduced.

To explain further, knitted fabrics are generally easy to deform, i.e., have high drapeability, and are suitable fabrics and base materials for manufacturing deep-drawn products. However, because of this, the products have low mechanical properties such as tensile strength, elasticity, and bending elasticity. The reason for this is that:
(1) When stress is applied, the base material itself is a knitted fabric, so it is easily deformed.
(2) The breaking strength of the loops that make up the knitted fabric comes from the knot strength of the fibers, which is lower than normal tensile strength (for example, carbon fibers have zero knot strength, making them unsuitable for use as fibers for loops).

For this reason, when stress (impact) is applied to the surface of a molded product, the part to which the stress is applied will flex and distort. If the amount of flex and distortion is large, the stress will be transmitted to the lower part of the molded product. In addition, the deformation of the knitted fabric or molded body will cause the loops that make up the knitted fabric, which are made of fibers with low knot strength, to break, destroying the molded body.

Therefore, the present inventors attempted to solve the above problems by providing a knitted fabric and a base material that can withstand deep drawing during molding.

In other words, the object of the present invention is to provide a mesh-like fiber-reinforced composite material which is made of a knitted base material that can withstand deep drawing during molding, has better elasticity and drape than general materials, is excellent in moldability into curved shapes and breathability, prevents stuffiness, is lightweight and strong, and also has high rigidity and excellent impact resistance, as well as a mesh-like knitted structure, a material for molding a mesh-like fiber-reinforced composite material, and a mesh-like fiber-reinforced composite molded body.

The above problems and objects can be solved by the mesh-like fiber-reinforced composite material, mesh-like knitted structure, mesh-like fiber-reinforced composite material molding material, and mesh-like fiber-reinforced composite material molded article of the present invention according to the following (1) to (4).
(1) Increasing the knot strength of the fibers that make up the loop.
(2) Use high-fineness fibers.
(3) Identify the type of fiber to be used.
(4) Identify a knitting structure that has excellent impact resistance.

In summary, according to the first aspect of the present invention, a mesh-like knitted structure is provided that is formed of three types of yarns: a knitted structure in which a chain stitch is formed by continuously looping a chain stitch yarn in the vertical direction; a horizontally inserted yarn that is inserted by turning back and forth three or more rows in each course through the knitted structure in the vertical direction; and a vertically inserted yarn that is inserted in a direction opposite to the horizontally inserted yarn, the chain stitch yarn being turned back and forth one row in each course.
A mesh-shaped fiber reinforced composite material in which only the knitted structure and the warp and weft insertion yarns in the mesh-shaped knitted structure are impregnated with a resin and hardened,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
The present invention provides a mesh-like fiber-reinforced composite material, characterized in that

According to the second aspect of the present invention, the present invention has a sheet-like mesh-like knitted structure formed of three types of yarns: a knitted structure in which a chain stitch is formed by looping a chain stitch yarn continuously in the vertical direction, a knitted structure in which a horizontal insertion yarn is inserted by turning back and forth three or more rows in each course through the knitted structure in the vertical direction, and a vertical insertion yarn is inserted in a vertical direction in which the chain stitch yarn is inserted one row in each course in the opposite direction to the horizontal insertion yarn;
The mesh-like knitted structure is shaped into a predetermined shape, and then only the knitted structure and the warp and weft insertion yarns in the mesh-like knitted structure are impregnated with a resin and hardened, to form a mesh-like fiber-reinforced composite material,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
The present invention provides a mesh-like fiber-reinforced composite material, characterized in that

According to one embodiment of the first and second present inventions, the resin impregnated into the mesh-like knitted structure is a thermosetting resin such as a room temperature curing or thermosetting epoxy resin, a vinyl ester resin, an MMA resin, an acrylic resin, an unsaturated polyester resin, or a phenolic resin; or a thermoplastic resin such as a thermoplastic epoxy resin, a phenoxy resin, a polycarbonate resin, a polyester resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, a polyether ether ketone resin, or a polyphenylene sulfide resin.

According to the third aspect of the present invention, the present invention has a sheet-like mesh-like knitted structure formed of three types of yarns: a knitted structure in which a chain stitch is formed by looping a chain stitch yarn continuously in the vertical direction; a horizontally inserted yarn in which the knitted structure in the vertical direction is inserted by turning back and forth three or more rows per course; and a vertically inserted yarn in which the chain stitch yarn is inserted in the vertical direction by turning back and forth one row per course in the opposite direction to the horizontally inserted yarn.
A mesh-shaped fiber-reinforced composite material in which only the knitted structure and the warp and weft insertion yarns in the mesh-shaped knitted structure are impregnated with a resin, hardened, and then shaped into a predetermined shape,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
The present invention provides a mesh-like fiber-reinforced composite material, characterized in that

According to one embodiment of the third present invention, the resin impregnated into the mesh-like knitted structure is a thermoplastic resin such as a thermoplastic epoxy resin, a phenoxy resin, a polycarbonate resin, a polyester resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, a polyether ether ketone resin, or a polyphenylene sulfide resin.

According to one embodiment of the present invention, the fibers used for the chain stitch yarns are single yarns or ply-twisted yarns of 40 tex or more, and the fibers used for the warp and weft insert yarns are single yarns or ply-twisted yarns of 80 tex or more.

According to one embodiment of the present invention, the mesh-like knitted structure has an opening ratio of 20 to 60%.

Furthermore, according to the fourth aspect of the present invention, there is provided a mesh-like knitted structure formed from three types of yarn: a knitted structure having multiple rows of chain stitches formed by continuous loops of chain knit yarn in the vertical direction; a horizontal insertion yarn having multiple rows that is inserted by folding back and forth through the vertical knitted structure in the horizontal direction for three or more rows per course; and a vertical insertion yarn that is inserted in a direction opposite to the horizontal insertion yarn for multiple rows, with one row per course.

According to the fifth aspect of the present invention, there is provided a mesh-like knitted structure formed of three types of yarns: a knitted structure in which a chain stitch is formed by continuously looping a chain stitch yarn in the vertical direction; a horizontally inserted yarn that is inserted by turning back and forth three or more rows in each course through the knitted structure in the vertical direction; and a vertically inserted yarn that is inserted in a direction opposite to the horizontally inserted yarn in a plurality of rows by turning back one row in each course.
The knitted structure in the mesh-like knitted structure and only the warp and weft insertion yarns are impregnated with resin,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers,
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
The present invention provides a material for molding a mesh-shaped fiber-reinforced composite material, which is characterized by:

According to a sixth aspect of the present invention, there is provided a mesh-shaped fiber-reinforced composite molding obtained by shaping the above-mentioned mesh-shaped fiber-reinforced composite molding material.

The mesh-like fiber reinforced composite material of the present invention is composed of a knitted fabric substrate that can withstand deep drawing during molding, has excellent elasticity and drapeability, and is excellent in moldability into a shape having a curved surface. Moreover, it has excellent breathability and can prevent stuffiness, is lightweight and has sufficient strength, and has high rigidity and improved impact resistance. For this reason, it is suitable as a filter, cover, or reinforcing member, and is particularly suitable as a member that constitutes the basic structure of various protectors, interior materials (inner) for prostheses (prostheses, prostheses), or exterior materials (frames), etc. In addition, the mesh-like fiber reinforced composite material of the present invention is suitably produced from the mesh-like knitted structure and the mesh-like fiber reinforced composite molding material of the present invention, and the mesh-like fiber reinforced composite molding material can be shaped to suitably produce a mesh-like fiber reinforced composite molding of a desired shape.

FIG. 1 is a partial knitted structure diagram showing one embodiment of a mesh-like knitted structure according to the present invention. FIG. 2 is an enlarged schematic view of the mesh-like knitted structure shown in FIG. FIG. 3 is a partial knitted structure diagram showing another embodiment of the mesh-like knitted structure according to the present invention. FIG. 4 is a schematic diagram of a conventional mesh-like knitted structure showing a comparative example of the present invention. 5(a) to (e) are diagrams illustrating an embodiment of a method for forming a mesh-shaped fiber-reinforced composite material according to the present invention. 6(a) and (b) are diagrams for explaining another embodiment of the method for forming a mesh-like fiber-reinforced composite material according to the present invention. 7(a) and (b) are diagrams showing an embodiment of a hat in which the mesh-shaped fiber-reinforced composite material of the present invention can be used as an inner material. FIG. 8(a) is a partial knitted structure diagram showing an example of a mesh-like knitted structure described in Japanese Patent No. 6,362,454, and FIG. 8(b) is a cross-sectional schematic diagram for explaining the resin impregnation state of the mesh-like knitted structure.

Hereinafter, the mesh-like fiber-reinforced composite material, the mesh-like knitted structure, the material for molding the mesh-like fiber-reinforced composite material, and the mesh-like fiber-reinforced composite molded article according to the present invention will be described in more detail with reference to the drawings.

In this specification, "curing" includes not only the curing caused by the thermosetting resin forming a three-dimensional network structure, but also the solidification of a thermoplastic resin from a fluid state.

Example 1
An embodiment of a mesh-like fiber reinforced composite material according to the present invention will be described with reference to Fig. 1. Fig. 1 is a partially enlarged knit structure diagram for explaining a sheet-like reinforcing fiber knitted fabric constructed according to the present invention, in particular a mesh-like knitted structure that is a sheet-like reinforcing fiber warp knitted fabric, i.e., a mesh-like fiber sheet 1.

The mesh-shaped fiber reinforced composite material according to the present invention has a knitted structure in the form of a mesh-like sheet, and is a mesh-shaped fiber reinforced composite material (FRP) obtained by impregnating the mesh-shaped knitted structure 1 with resin and hardening the mesh-shaped knitted structure 1 while maintaining the mesh (void portion) G formed in the mesh-shaped knitted structure 1. In other words, the mesh-shaped fiber reinforced composite material according to the present invention is a mesh-shaped fiber reinforced composite material (FRP) obtained by impregnating each constituent yarn of the mesh-shaped knitted structure 1 shown in Fig. 1 with resin and hardening the same.

As mentioned above, when stress (impact) is applied to the surface of a molded product formed from a mesh-shaped fiber-reinforced composite material, the part to which the stress is applied will bend and distort. If the amount of bending or distortion is large, the stress will be transmitted to the lower part of the molded product. Furthermore, when stress is applied to an FRP that uses a knitted fabric substrate such as a circular knit, weft knit, or warp knit, the destruction occurs as the loops that make up the knitted fabric, which has low knot strength, break. To solve this problem,
(1) Increasing the knot strength of the fibers that make up the loop.
(2) Use high-fineness fibers.
(3) Identify the type of fiber to be used.
(4) Identify a knitting structure that has excellent impact resistance.
Possible reasons include:

The present invention aims to solve the above problems and provide a knitted fabric base material that can withstand deep drawing during molding.

Generally, when a knitted item is damaged by an impact from above, the chain stitch yarn breaks first, causing the yarn to unravel. To prevent the chain stitch yarn from breaking,
(1) Increase the strength of the chain stitch yarn. In other words, improve cut resistance by considering the material and thickness.
(2) The load received by the chain stitch yarns is also borne by the other yarns. In other words, the main warp yarns are swung in the opposite direction to the main weft yarns, so that the yarns are crossed and receive the load.
(3) The presence of main yarns on both sides of the chain stitch yarns reduces eccentricity in the warp direction.
(4) The difference in the amount of warp and weft main threads is reduced to suppress the difference in the amount of deformation due to directional differences.
(5) To prevent the chain stitch yarn from breaking and the knitting structure from collapsing, the main warp threads are swung in at least three rows (needles). Even if one chain stitch thread breaks, one of the main warp threads will not come undone, so the main weft threads can bear the load. However, the remaining structure due to the broken chain stitch yarn has a wider vertical spacing and a reduced amount of thread, so its strength is significantly reduced.
(6) The chain stitch yarn and the main yarn should have similar physical properties.
It is important that:

1, the mesh-like knitted structure 1 according to the present invention is a mesh-like sheet formed of three types of yarns: a knitted structure 20 in which a chain stitch yarn 2 is continuously looped in the vertical direction to form stitches 2A, a plurality of rows of horizontal insertion yarns 3 which are inserted by turning back and forth through the vertical knitted structure 20 in three or more rows, for example, three to six rows, in each course, and a plurality of vertical insertion yarns 4 which are inserted vertically in one row per course in the opposite direction to the horizontal insertion yarns 3. The mesh-like knitted structure may be a web or a ribbon.

After or before forming the mesh-like knitted structure 1 into a predetermined shape, only the chain stitch yarns 2, the horizontal insert yarns 3, and the vertical insert yarns 4 in the mesh-like knitted structure 1 are impregnated with resin. That is, as will be described in detail later, the mesh-like knitted structure 1 is formed into a predetermined shape, and then only the chain stitch yarns 2, the horizontal insert yarns 3, and the vertical insert yarns 4 that form the mesh-like knitted structure 1 are impregnated with resin and hardened to form a mesh-like fiber-reinforced composite material of a predetermined shape, or the mesh-like knitted structure 1 is first impregnated with resin only the chain stitch yarns 2, the horizontal insert yarns 3, and the vertical insert yarns 4, and then heated and molded into a predetermined shape to form a mesh-like fiber-reinforced composite material. The mesh-like knitted structure 1 configured as described above has excellent drapeability, is capable of deep drawing, and is very easy to mold into a composite material.

A typical warp knitted fabric base material is formed of loops of chain stitch yarn 2 and insert yarns that cross over two or more rows of the chain stitch yarn 2, and therefore cannot utilize the strongest tensile strength in the pulling direction, which is a characteristic of the fiber, and so yarn breakage easily occurs, the knitted structure 20 is destroyed, and rigidity is difficult to obtain. The main cause of the destruction of the knitted structure 20 is that the loops of the chain stitch yarn 2 are broken, making it impossible to bind the horizontal and vertical insert yarns 3, 4. The mesh-like knitted structure 1 according to the present invention obtains rigidity by compensating for the characteristics of the general warp knitted fabric described above using the materials used and the knitted structure.

A typical warp knitted fabric substrate is formed of a loop of a chain knit yarn 2 and horizontal and vertical insertion yarns 3, 4 that are woven in two or more rows of the chain knit yarn 2, and therefore has excellent elasticity in all directions and good shaping properties. The mesh-like knitted structure 1 according to the present invention hardly stretches in the vertical direction, but shrinks in the vertical direction and expands and contracts in the horizontal direction. Although its shaping properties are inferior to those of a typical warp knitted fabric substrate, it can be shaped into a hemispherical shape without any problems.

Next, the mesh-like knitted structure 1 constituting the mesh-like fiber-reinforced composite material of the present invention will be further described.

(Mesh-like knitted structure)
Referring to FIG. 1, the mesh-like knitted structure 1 constituting the mesh-like fiber-reinforced composite material of the present invention has, as described above, chain stitch yarns 2 forming a knitted structure 20, weft insertion yarns 3 inserted horizontally into the vertical knitted structure 20, and vertical insertion yarns 4 inserted in the opposite direction to the weft insertion yarns 3 through the chain stitch yarns 2.

In the mesh-like knitted structure 1 of the present invention, the chain stitch yarn 2 is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The weft insertion yarn 3 and the warp insertion yarn 4 are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
It is said.

As described above, the chain stitch yarn 2 used in the present invention is preferably selected according to the intended use of the mesh-like fiber-reinforced composite material from organic fibers such as polyester, nylon, vinylon, etc., or high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers, or inorganic fibers such as glass long fibers and basalt fibers, as single yarns or double-twisted yarns. If the count is too fine, the impact resistance of the mesh-like fiber-reinforced composite material decreases, so the count is set to 40 tex or more, and is preferably selected according to the intended use of the mesh-like fiber-reinforced composite material.

The weft insertion yarns 3 used in the present invention are preferably selected as single yarns or double-twisted yarns using inorganic fibers such as long glass fibers and basalt fibers, as well as high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and long high-strength polyarylate fibers, depending on the intended use of the mesh-shaped fiber-reinforced composite material. If the yarn count is too small, the strength will not be obtained in the first place, so the yarn count should be at least 80 tex, preferably 100 tex, depending on the intended use of the mesh-shaped fiber-reinforced composite material.

The warp insertion yarns 4 used in the present invention are preferably selected as single yarns or double-twisted yarns using inorganic fibers such as long glass fibers and basalt fibers, as well as high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and long high-strength polyarylate fibers, depending on the intended use of the mesh-shaped fiber-reinforced composite material. If the yarn count is too small, the strength is not obtained in the first place, so the yarn count should be at least 80 tex, preferably 100 tex, depending on the intended use of the mesh-shaped fiber-reinforced composite material.

The mesh-shaped fiber-reinforced composite material of the present invention is a mesh-shaped fiber-reinforced composite material formed into a curved shape by impregnating and hardening only the knitted structure 20 (chain stitch yarn 2) and the warp and weft insertion yarns 4, 3 in the mesh-shaped knitted structure shown in Figure 1 with resin.

In order to further improve the impact resistance of the FRP in the mesh-shaped fiber-reinforced composite material of the present invention, it is preferable to use a resin with a large breaking elongation in order to increase the impact absorption energy in the resin part. In the case of a thermoplastic resin, a thermoplastic epoxy resin, a phenoxy resin, a polycarbonate resin, a polyester resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, a polyetheretherketone resin, a polyphenylene sulfide resin, etc. are used, and in the case of a thermosetting resin, a room temperature curing type or a thermosetting type epoxy resin, a vinyl ester resin, a MMA resin, an acrylic resin, an unsaturated polyester resin, a phenolic resin, etc. are used, and a high breaking elongation resin with a breaking elongation of 4% or more is preferable.

The thermoplastic epoxy resin is a linear polymer exhibiting thermoplasticity, which is produced by chain extension of a bifunctional epoxy compound and a bifunctional phenolic compound through addition polymerization accompanied by ring-opening of the epoxy ring. For example, the thermoplastic epoxy resin can be obtained by blending bisphenol A type epoxy resin and bisphenol A in a functional group ratio of 1:1, and polymerizing the mixture in situ in the presence of a phosphorus-based polymerization catalyst.

The mesh-like knitted structure 1 according to the present invention does not stretch in the vertical direction, but does shrink in the vertical direction and expand and contract in the horizontal direction. Although its shapeability is inferior to that of a general warp knitted fabric substrate, it can be shaped into a hemispherical shape without any problems.

A typical warp knitted fabric base material is formed of loops of chain stitch yarns 2 and weft insert yarns 3 that loop the chain stitch yarns 2 in two or more rows. The weft insert yarns 3 are folded back and bound to the chain stitch yarns 2, so the load received by the weft insert yarns 3 is always transmitted to the chain stitch yarns 2. Because the chain stitch yarns 2 have the property of forming loops and are often made of fine yarn count yarns for ease of knitting, they are weak in strength and are the first to break.

In contrast, the mesh-like knitted structure 1 according to the present invention uses, for example, polyester long fibers for the chain stitch yarn 2, and increases the amount of fibers used compared to ordinary ones to increase the cross-sectional area, thereby improving the cross-sectional performance and increasing the strength of the chain stitch yarn 2. In addition, by binding the vertical insertion yarn 4 along the chain stitch yarn 2 one row at a time with the horizontal insertion yarn 3 in the reverse swing, the horizontal insertion yarn 3 and the vertical insertion yarn 4 cross at the loop part, so that the load received by the chain stitch yarn 2 is borne by the vertical insertion yarn 4, and the load received is reduced. By folding back and swinging the horizontal insertion yarn 3 across three rows of the chain stitch yarn 2, the chain stitch yarn 2 that receives the load becomes four rows, and the load borne by one row of the chain stitch yarn 2 is reduced. The horizontal insertion yarn 3 is not limited to being inserted across three rows of the chain stitch yarn 2, and can be inserted into the chain stitch yarn 2 by folding back and swinging across four or more rows, for example. As can be seen from the shape of FIG. 1, even if one row of the chain stitch yarns 2 is destroyed and the knitted structure 20 is destroyed, the weft insertion yarns 3 bind the chain stitch yarns 2 across three or more rows, so this does not lead to large-scale destruction of the knitted structure 20.

2, the load most likely to act on the chain stitch yarn 2 is the hook load at the intersection of force P3, which is generated when the weft insertion yarn 3 tries to stretch laterally due to deformation when the mesh-like knitted structure 1 receives an impact, and force P4, which is generated when the warp insertion yarn 4 tries to stretch vertically. Therefore, by improving the cross-sectional performance of the chain stitch yarn 2 and dispersing the load it receives, the chain stitch yarn 2 is less likely to break, and the mesh-like knitted structure 1 becomes a structure that is resistant to impact loads.

Specific Example 1
In one embodiment of the present invention, the mesh-like knitted structure 1 is a mesh-like sheet knit formed by using polyester fiber as the chain stitch yarns 2 and long glass fiber as the weft insertion yarns 3 and warp insertion yarns 4 .

The mesh-like knitted structure 1 of this specific example 1 will be described with reference to Figure 1. In this specific example 1, the knitted structure 20 in the mesh-like knitted structure 1 has a chain stitch yarn 2 that forms a loop in the vertical direction, and a transverse insertion yarn 3 and a longitudinal insertion yarn 4 that are knitted into the loop and bound together. The shape of the loop may be a tricot structure other than the knitted structure (so-called raschel structure) 20 shown in this specific example, or may be a structure that combines the raschel structure and tricot structure of this specific example. The knitted structure 20 in the mesh-like knitted structure 1 is desirably selected depending on the intended use of the mesh-like fiber-reinforced composite material.

In this specific example 1, the polyester fiber used as the chain stitch yarn 2 forming the knitted texture 20 in the mesh-like knitted structure 1 was a polyester fiber of 110 tex.

The long glass fibers used as the weft insertion yarns 3 and the warp insertion yarns 4 are classified into E glass, T glass, NE glass, etc. according to the characteristics of the glass, but E glass (general-purpose product) was used in this specific example 1. It is desirable to select the long glass fibers according to the purpose of use of the mesh-like fiber-reinforced composite material.

In addition, the long glass fiber has various kinds and counts, such as glass yarn, glass direct roving, and glass doubling roving, depending on the manufacturing method, and it is desirable to select according to the purpose of use of the mesh-like fiber reinforced composite material and the mesh size. Also, if the count of the long glass fiber used is too small, it will not have enough strength in the first place, so as mentioned above, it is desirable to use 100 tex or more. In this specific example 1, the long glass fiber used for the weft insertion yarn 3 and the warp insertion yarn 4 is a glass yarn doubling yarn of 420 tex.

That is, in this specific example 1, the mesh-like knitted structure 1 is a mesh-like sheet formed of three types of yarns: a knitted structure 20 in which multiple rows of loop-shaped chain knit yarns 2 using polyester fiber 110 tex are continuously formed in the vertical direction to form knit stitches, a horizontal insertion yarn 3 using long glass fiber 420 tex in multiple rows that is folded back and inserted across the horizontal chain knit yarns 2 in the horizontal direction for three or more rows in every course, and a vertical insertion yarn 4 using long glass fiber 420 tex that is inserted in the vertical direction for multiple rows that is inserted in one row in every course in the opposite direction to the horizontal insertion yarn 3. The mass of the mesh-like knitted structure 1 in this specific example 1 is 476 g/ ^m2 .

The mesh knitted structure 1 of this specific example 1 can be produced using a single raschel knitting machine, and can also be knitted using a tricot knitting machine, a crochet knitting machine, etc. Such knitting manufacturing methods are well known in the art, so further detailed explanations will be omitted.

Example 2
According to another specific example 2 of the present invention, the mesh-like knitted structure 1 is a mesh-like sheet knit formed by using aramid long fibers as the chain stitch yarns 2 and glass long fibers as the weft insertion yarns 3 and warp insertion yarns 4.

In this Example 2, the aramid filaments used for the chain stitch yarn 2 are 88 tex yarns obtained by plying and twisting standard para-aramid fibers.

The mesh-like knitted structure 1 of this specific example 2 also has a knit structure similar to that of the mesh-like knitted structure 1 of specific example 1 described with reference to Fig. 1, and the difference between this specific example 2 and specific example 1 is that the chain stitch yarn 2 is changed to aramid long fiber, particularly aramid long fiber ply-twisted yarn 88 tex. This change increases the strength of the chain stitch yarn, improving the impact load resistance of the mesh-like knitted structure 1 of this specific example 2. The mass of the mesh-like knitted structure 1 of this specific example ² is 461 g/m2.

The mesh knitted structure 1 of this specific example 2 can be produced using a single raschel knitting machine, and can also be knitted using a tricot knitting machine, a crochet knitting machine, etc. Such a knitting manufacturing method is well known in the art, so further detailed explanation will be omitted.

Specific Example 3
Next, another embodiment 3 of the present invention will be described with reference to Fig. 3. The knitting structure 20 of the mesh-like knitted structure 1 used in this embodiment 3 is not limited to the above embodiment. As shown in Fig. 3, the loop shape of the chain stitch yarn 2 can be a tricot structure.

In this specific example 3, the chain stitch yarn 2 and the horizontal and vertical insertion yarns 3, 4 forming the tricot weave used in the mesh-like knitted structure 1 are similar to those described in the above examples and specifically described in the above specific examples 1 and 2, and are selected appropriately depending on the intended use of the mesh-like fiber-reinforced composite material.

(Opening ratio)
In the present invention, the opening rate of the mesh-like fiber-reinforced composite material 10 produced using the above-mentioned mesh-like knitted structure 1 is important, and as described in detail later, the opening rate is 20 to 60%, preferably 20 to 50%, and more preferably 30 to 50%.

According to the present invention, the mesh-like knitted structure 1 is impregnated with resin and hardened only in the knitted structure 20 formed by the chain stitch yarn 2 and the warp and weft insertion yarns 4, 3 in the mesh-like knitted structure 1; in other words, the voids G in the mesh-like knitted structure 1 are not filled with resin, so that the opening rate of the mesh-like fiber-reinforced composite material 10 is substantially the same as the opening rate of the mesh-like knitted structure 1.

The aperture ratio generally means the ratio of holes in a plane used in, for example, mesh fabrics for screen printing or punching metals. Similarly, in the present invention, the aperture ratio of the mesh-like knitted structure 1 means the ratio of holes in a plane of the mesh-like knitted structure 1. The mesh-like knitted structure 1 is read with a two-dimensional scanner, and the ratio of the part with fiber to the part without fiber is calculated. In practice, the mesh-like knitted structure 1 is read with a two-dimensional scanner, and the aperture ratio is calculated by dividing it into void parts and fiber parts using image software. For example, such an aperture ratio can be efficiently determined using a two-dimensional scanner (product name "CanoScan4400F" manufactured by Canon Inc.
Opening rate (%)={(area of void portion)/(area of fiber portion+area of void portion)}×100

As described above, in the present invention, the opening rate of the mesh-like knitted structure 1 is set to 20 to 60%. If the opening rate is less than 20%, the rigidity is very good, but the holes do not open after molding, the breathability is poor, and the structure is very heavy. If the opening rate exceeds 60%, the breathability is very good and the structure is lightweight, but the amount of reinforcing fibers is insufficient overall, and the rigidity is insufficient. The opening rate is preferably set to 20 to 50%, and more preferably 30 to 50%.

In the present invention, the size of each opening (hole) in the mesh-like knitted structure 1 is also important, and it is important that the area of each opening is 1.5 to 80 ^mm2 . If the area of each opening is less than 1.5 ^mm2 , there is a possibility that no holes will be formed during molding, and if the area of each opening exceeds 80 ^mm2 , the mesh after molding will become too large, and there is a possibility that the rigidity of the mesh-like fiber-reinforced composite material 10 will be lost.

(Impregnating resin)
In the present invention, as described above, after or before the mesh-like knitted structure 1 is shaped into a predetermined shape, only the knitted texture 20 and the warp and weft insertion yarns 4, 3 in the mesh-like knitted structure 1 are impregnated with resin and hardened to form the mesh-like fiber-reinforced composite material 10. The fiber content in the mesh-like fiber-reinforced composite material 10 is 30 to 70%, preferably 40 to 70%, by weight of the fiber.

In the above examples, examples of thermoplastic resins include thermoplastic epoxy resins, phenoxy resins, polycarbonate resins, polyester resins, polyurethane resins, polyamide resins, polyetherimide resins, polyether ether ketone resins, and polyphenylene sulfide resins, and examples of thermosetting resins include room temperature curing or thermosetting epoxy resins, vinyl ester resins, MMA resins, acrylic resins, unsaturated polyester resins, and phenolic resins. However, it is preferable to use a thermoplastic resin, more preferably a thermoplastic resin having a breaking elongation of 4% or more, even more preferably a thermoplastic resin having a breaking elongation of 10% or more, and most preferably a thermoplastic resin having a breaking elongation of 50% or more.

(Molding method)
Next, a method for molding the mesh-shaped fiber-reinforced composite material 10 according to the present invention will be described.

The mesh-shaped fiber reinforced composite material 10 can be formed using the same molding methods as those used for conventionally known fiber reinforced composite materials, such as press molding, sheet winding molding, tape winding molding, and hand bending molding.

5(a) to (c) show a press molding method, which is one embodiment of a molding method. According to this press molding method, the mesh-like knitted structure 1 is fitted to a convex male mold 201, and by pressing, the mesh-like knitted structure 1 is molded according to the male mold 201 (FIG. 5(a)). At this time, the mesh-like knitted structure 1 produced according to the present invention has good drapeability, stretchability, good moldability, and is easy to work with, as described above.

Next, in order to impregnate only the knitted structure 20 made of the chain stitch yarn 2 and the warp and weft insertion yarns 4 and 3 of the mesh-like knitted structure 1 with the resin, the mesh-like knitted structure 1 is coated with the resin R using an impregnation brush or the like (FIG. 5(b)). The resin R may be a thermosetting resin or a thermoplastic resin. Then, a concave female mold 202 is placed in correspondence with the male mold 201, and the resin R is hardened by applying pressure with a predetermined pressing force and heating, and the mesh-like fiber-reinforced composite material 10 shaped into a predetermined shape is molded (FIG. 5(c)). The mesh-like fiber-reinforced composite material 10 is removed from the mold (FIG. 5(d)) and finished into a predetermined shape (FIG. 5(e)).

6(a) and (b) show a vacuum molding method, which is another embodiment of the molding method. According to this vacuum molding method, the mesh-like knitted structure 1 is formed by impregnating and curing only the knitted structure 20 consisting of the chain stitch yarn 2 and the warp and weft insertion yarns 4, 3 with resin, forming a flat mesh-like knitted structure 1a made of FRP material. Although a thermosetting resin can also be used as the resin by bringing it to a B-stage state, a thermoplastic resin is preferably used. The mesh-like knitted structure may be impregnated with resin in advance by coating or impregnation, or may be impregnated with resin immediately before molding.

The mesh-like knitted structure 1, which has been impregnated with resin R by coating or immersion and hardened, is placed on a concave vacuum mold (female mold) 202 as a mesh-like fiber-reinforced composite molding material 1a, and is further covered with a resin film 60 (FIG. 6(a)). The female mold 202 is evacuated, and the male mold 201 is pressurized with a predetermined pressing force from the resin film 60 side so as to fit the female mold 202, and heated. As a result, the resin impregnated and hardened in the mesh-like knitted structure 1a is softened (melted) and molded according to the female mold 202. The mold is cooled to obtain a mesh-like fiber-reinforced composite material 10 shaped into a predetermined shape (FIG. 6(b)). Thereafter, as in the press molding method, the mesh-like fiber-reinforced composite material 10 is removed from the mold and finished into a predetermined shape as shown in FIGS. 5(d) and (e).

In this vacuum molding method, when the resin is softened or melted, the mesh-like knitted structure 1 has good drapeability, stretchability, and moldability, and is molded following the male mold, making the process easy.

According to the above-mentioned vacuum molding method, the mesh-like knitted structure 1, which has been previously coated or impregnated with resin and then hardened, can be used like a prepreg as the mesh-like fiber-reinforced composite molding material 1a, so that productivity is good, and there are advantages in that the pores of the mesh-like knitted structure 1 are not crushed during molding, and the sheet thickness does not become thin during molding, resulting in a composite material with a thick cross section, which makes it easier to obtain high strength.

(Experimental Examples 1-2, Comparative Examples 1-2)
Next, in order to verify the effects of the mesh-like fiber reinforced composite material 10 and the mesh-like knitted structure 1 according to the present invention, the impact strength of the mesh-like fiber reinforced composite material was verified by changing the types of the chain stitch yarns 2, the weft insertion yarns 3, and the warp insertion yarns 4 of the mesh-like knitted structure 1. Details of the mesh-like knitted structure 1 and the verification results of the impact strength of the mesh-like reinforced composite material are shown in Table 1.

In this experiment, the mesh-shaped knitted structure 1 was impregnated with a thermoplastic epoxy resin (manufactured by Nagase ChemteX Corporation, product name "XNR6850V") as an impregnating resin, and then the solvent was dried in an oven at 120°C for 10 minutes, and then the mesh-shaped fiber-reinforced composite material was produced by heating in a mold at 160°C for 30 minutes. At this time, the fiber content in the composite material was 65% by weight of the fiber.

The impact strength was verified by a punching impact strength test (drop mass: 1.59 kg, drop height: 580 mm, striker: 20 mm hemispherical) using a mesh-like fiber composite material molded into a flat plate using an Instron universal testing machine "CEAST9310." In Table 1, "Peak Force/mass" is the maximum load per unit mass, and the larger this value, the more excellent the impact resistance of the structure can be determined.

Experimental Example 1
The mesh-like knitted structure 1 used in Experimental Example 1 used the mesh-like knitted structure 1 produced in Specific Example 1 as the knitted fabric base material. With reference to Fig. 1, the shape was such that the vertical row spacing (SB) was 4 mm and the horizontal row spacing (SA) was 5 mm. The chain stitch yarns 2 were 110 tex polyester fiber, the horizontal insertion yarns 3 were 420 tex long glass fiber ply-twisted yarns, and the vertical insertion yarns 4 were 420 tex long glass fiber ply-twisted yarns. The mass of the mesh-like knitted structure 1 was 476 g/ ^m2 , and the opening ratio was 45%.

As a result of a punching impact strength test, the mesh-like fiber composite material 10 produced using the mesh-like knitted structure 1 exhibited a maximum impact resistance load of 852N, and the knitted structure 20 was destroyed after the test.

Experimental Example 2
The mesh-like knitted structure 1 used in Experimental Example 2 used the mesh-like knitted structure 1 produced in Specific Example 2 as the knitted fabric base material. The shape was such that the vertical row spacing (SB) was 4 mm and the horizontal row spacing (SA) was 5 mm. The chain stitch yarn 2 was 88 tex aramid long fiber ply-twisted yarn, the horizontal insertion yarn 3 was 420 tex long glass fiber ply-twisted yarn, and the vertical insertion yarn 4 was 420 tex long glass fiber ply-twisted yarn. The mass of the mesh-like knitted structure 1 was 461 g/ ^m2 , and the opening ratio was 40%.

As a result of a punching impact strength test, the mesh-like fiber composite material 10 produced using the mesh-like knitted structure 1 of this experimental example showed a maximum impact load of 1,748 N. In addition, although the knitted structure 20 was deformed after the test, it did not break, confirming that the strength of the chain stitch yarn 2 has a significant effect on the impact load resistance.

Comparative Example 1
The knitted fabric base material used in the mesh knitted structure 1 used in Comparative Example 1 had the same knitted structure 20 as in Experimental Examples 1 and 2, with a vertical row spacing (SB) of 4 mm and a horizontal row spacing (SA) of 5 mm. The chain stitch yarn 2 was an aramid long fiber ply-twisted yarn of 88 tex, the horizontal insertion yarn 3 was a carbon fiber strand of 400 tex, and the vertical insertion yarn 4 was a carbon fiber strand of 400 tex. The mass of the mesh knitted structure 1 was 488 g/ ^m2 , and the opening ratio was 29%.

As a result of a punching impact strength test, the mesh-like fiber composite material 10 produced using the mesh-like knitted structure 1 of Comparative Example 1 exhibited a maximum impact load of 1254 N, and the knitted structure 20 was destroyed after the test.

In this comparative example, the long glass fibers of the horizontal and vertical inserted yarns 3 and 4 in Experimental Example 2 were replaced with carbon fiber strands, and the purpose was to compare the impact load resistance performance of the long glass fiber and the carbon fiber strands. The carbon fiber used in this comparative example had a count 20 less than the long glass fiber, but the specific gravity of the carbon fiber was 1.8 compared to 2.6 for the glass fiber, so that although the inserted yarn volume was 1.37 times larger, the maximum load resistance was only 72%, and it was confirmed that the carbon fiber strands were weaker against impact loads than the long glass fiber.

Furthermore, the volume of the carbon fiber is larger than the volume of the glass fiber, which reduces the opening ratio and results in poor ventilation.

Comparative Example 2
Comparative Example 2 is a mesh-like fiber-reinforced composite material using the mesh-like knitted structure 1A shown in Fig. 4, and has the same configuration as the mesh-like knitted structure 1A described in Patent Document 3 (Japanese Patent No. 6362454) and explained with reference to Figs. 8(a) and (b) attached to this application. Comparative Example 2 was a mesh-like fiber-reinforced composite material 10A in which the chain stitch yarns 2 and weft insertion yarns 3 in this mesh-like knitted structure 1A were impregnated with resin and hardened.

The mesh knitted structure 1A used in Comparative Example 2 had the knitting structure shown in Fig. 4, with a vertical row spacing (SB) of 4 mm and a horizontal row spacing (SA) of 5 mm. The chain stitch yarn 2 was 88 tex aramid long fiber ply-twisted yarn, the horizontal insertion yarn 3 was 1145 tex glass long fiber ply-twisted yarn, the mass of the mesh knitted structure 1A was 674 g/ ^m2 , and the opening ratio was 38%.

The mesh-like fiber-reinforced composite material 10A produced using the mesh-like knitted structure 1A of Comparative Example 2 had a maximum impact load of 441 N in a punching impact strength test, and the knitted structure 20 was destroyed after the test.

In Comparative Example 2, the load-bearing performance of a highly elastic knitted structure 20 is confirmed by reinforcing it with chain stitch yarn 2 and weft inserted yarn 3. Although the strength of the chain stitch yarn 2 is greater than in Experimental Example 1 and the fiber content of the weft inserted yarn 3 is greater, the impact load resistance is only 53% of that of Experimental Example 1, confirming that the knitted structure 20 of the mesh-shaped fiber-reinforced composite material shown in Experimental Example 2 is effective in resisting impact loads.

The mesh-like fiber composite material of the present invention is particularly suitable as a protector such as a protective hat, or an interior/exterior member for artificial limbs (prosthetic legs, artificial hands), but is not limited to these applications. For example, it can be used as a medical material such as a cast for immobilizing an affected part, clothing and equipment such as shoes and hats for sports and leisure, a filter or housing member, a reinforcing or protective member for pipes and hoses, a reinforcing member for structures, or a structural member or a decorative member for aircraft, rockets, artificial satellites, automobiles, motorcycles, trains, bicycles, houses, optical instruments, home appliances, portable electronic devices, etc., which are required to be molded into a complex curved shape while maintaining high rigidity, and can also be used suitably for a wide range of industrial and consumer applications, such as houses.

Reference Signs List 1 Mesh-like knitted structure 1a Mesh-like fiber-reinforced composite molding material 2 Chain-knit yarn 2A Chain stitch 3 Horizontal insertion yarn 4 Vertical insertion yarn 10 Mesh-like fiber-reinforced composite material 20 Knit structure

Claims (10)

The mesh-like knitted structure is formed of three types of yarns: a knitted structure in which a plurality of rows of chain stitches are formed by continuous loops of chain stitch yarns in the vertical direction; a plurality of rows of horizontal insertion yarns that are inserted by turning back and forth three or more rows per course through the knitted structure in the vertical direction; and a vertical insertion yarn that is inserted in a direction opposite to the horizontal insertion yarns, the chain stitch yarns being turned one row per course in a plurality of rows.
A mesh-shaped fiber reinforced composite material in which only the knitted structure and the warp and weft insertion yarns in the mesh-shaped knitted structure are impregnated with a resin and hardened,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
A mesh-like fiber-reinforced composite material, characterized in that The knitted structure has a mesh-like sheet shape formed of three kinds of yarns: a knitted structure in which a plurality of rows of chain stitches are formed by continuous loops of chain stitch yarns in the vertical direction; a plurality of rows of horizontally inserted yarns that are inserted by turning back and forth through the knitted structure in the vertical direction for three or more rows per course; and a vertically inserted yarn that is inserted in the vertical direction for one row per course in the opposite direction to the horizontally inserted yarn.
The mesh-like knitted structure is shaped into a predetermined shape, and then only the knitted structure and the warp and weft insertion yarns in the mesh-like knitted structure are impregnated with a resin and hardened, to form a mesh-like fiber-reinforced composite material,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
A mesh-like fiber-reinforced composite material, characterized in that 3. The mesh-shaped fiber-reinforced composite material according to claim 1 or 2, characterized in that the resin impregnated into the mesh-shaped knitted structure is a thermosetting resin such as a room temperature curing or thermosetting epoxy resin, a vinyl ester resin, an MMA resin, an acrylic resin, an unsaturated polyester resin, or a phenolic resin; or a thermoplastic resin such as a thermoplastic epoxy resin, a phenoxy resin, a polycarbonate resin, a polyester resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, a polyether ether ketone resin, or a polyphenylene sulfide resin. The knitted structure has a mesh-like sheet shape formed of three kinds of yarns: a knitted structure in which a plurality of rows of chain stitches are formed by continuous loops of chain stitch yarns in the vertical direction; a plurality of rows of horizontally inserted yarns that are inserted by turning back and forth through the knitted structure in the vertical direction for three or more rows per course; and a vertically inserted yarn that is inserted in the vertical direction for one row per course in the opposite direction to the horizontally inserted yarn.
A mesh-shaped fiber-reinforced composite material in which only the knitted structure and the warp and weft insertion yarns in the mesh-shaped knitted structure are impregnated with a resin, hardened, and then shaped into a predetermined shape,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers.
and
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
A mesh-like fiber-reinforced composite material, characterized in that 5. The mesh-shaped fiber-reinforced composite material according to claim 4, characterized in that the resin impregnated into the mesh-shaped knitted structure is a thermoplastic resin such as a thermoplastic epoxy resin, a phenoxy resin, a polycarbonate resin, a polyester resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, a polyether ether ketone resin, or a polyphenylene sulfide resin. The fiber used for the chain stitch yarn is a single yarn or a ply-twisted yarn having a fineness of 40 tex or more, and the fiber used for the warp and weft insertion yarn is a single yarn or a ply-twisted yarn having a fineness of 80 tex or more. The mesh-like fiber-reinforced composite material according to any one of claims 1 to 5. 7. The mesh-like fiber-reinforced composite material according to claim 1, wherein the mesh-like knitted structure has an opening ratio of 20 to 60%. The mesh-like knitted structure is formed from three types of yarns: a knitted structure having multiple rows of vertical chain stitches formed by continuous loops of chain stitch yarns; a horizontally inserted yarn having multiple rows that are inserted by folding back and forth through the vertical knitted structure in the horizontal direction for at least three rows per course; and a vertically inserted yarn that is inserted in a multiple-row direction by folding back the chain stitch yarn in one row per course in the opposite direction to the horizontally inserted yarn. The mesh-like knitted structure is formed of three types of yarns: a knitted structure in which a plurality of rows of chain stitches are formed by continuous loops of chain stitch yarns in the vertical direction; a plurality of rows of horizontal insertion yarns that are inserted by turning back and forth three or more rows per course through the knitted structure in the vertical direction; and a vertical insertion yarn that is inserted in a direction opposite to the horizontal insertion yarns, the chain stitch yarns being turned one row per course in a plurality of rows.
The knitted structure in the mesh-like knitted structure and only the warp and weft insertion yarns are impregnated with resin,
The chain stitch yarn is
(a) organic fibers such as polyester, nylon, and vinylon; (b) high-strength fibers such as aramid long fibers, PBO long fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers; or (c) inorganic fibers such as glass long fibers and basalt fibers,
The warp and weft insertion yarns are
(a) inorganic fibers such as long glass fibers and basalt fibers, or (b) high-strength fibers such as long aramid fibers, long PBO fibers, ultra-high molecular weight polyethylene fibers, and high-strength polyarylate long fibers;
A mesh-shaped fiber-reinforced composite molding material, characterized in that A mesh-like fiber-reinforced composite molding obtained by shaping the mesh-like fiber-reinforced composite molding material according to claim 9.

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