JP7048956B2 - FRP molded product and its manufacturing method - Google Patents

Description

The present invention relates to an FRP molded product and a method for producing the same.

Fiber reinforced plastic (hereinafter referred to as "FRP") is lightweight, has high strength, and has a high elastic modulus, so it is widely used in the fields of daily life such as bathtubs, aerospace fields, mobile fields such as automobiles, and sports fields. Has been done. Among FRP, carbon fiber reinforced plastic (hereinafter referred to as "CFRP") whose fiber is carbon fiber is attracting attention and its use is expanding because of its particularly excellent elasticity and strength.

In recent years, the expansion of applications of FRP to protective equipment such as helmets and home appliances such as smartphone cases has been studied, and in order to use FRP for these applications, it is important to improve impact resistance. Since CFRP is a brittle material that is particularly fragile, it is strongly required to improve impact resistance.

Patent Document 1 has a transparent gel coat layer on the outermost surface for the purpose of providing an FRP molded product having a deep and highly designable pattern and excellent heat resistance, impact resistance, and heat insulation. The inner layer is a specific multicolor gel coat layer, the inner layer is a reinforced fiber reinforced resin layer containing a predetermined reinforcing fiber, and a synthetic resin foam layer is further laminated on the resin layer. The FRP molded product is disclosed. In this document, in Example 1, from the outermost surface side to the inside, a specific transparent gel coat layer, a specific multicolor gel coat layer, a reinforcing fiber reinforcing resin layer containing glass fiber, a reinforcing material, a lining layer, and It is described that an FRP bathtub on which a urethane resin foam layer is formed was produced. Further, in this document, the FRP bathtub of Example 1 was subjected to a falling ball impact test in which a 110 g steel ball was dropped from a height of 2 m to the center of the bathtub. It is stated that did not occur.

Japanese Unexamined Patent Publication No. 10-16070

However, when a relatively soft synthetic resin foam layer is laminated on the reinforced fiber reinforced resin layer as in Example 1 of Patent Document 1, the strength and elastic modulus are lowered. Further, in Example 1 of this document, it is necessary not only to increase the thickness of the synthetic resin foam layer, but also to form a reinforcing material for ensuring sufficient strength and a backing layer for fixing the reinforcing material. Because of the increased thickness of these layers, the methods described in this document do not allow the production of thin molded articles. Further, in the method described in this document, since the synthetic resin foam layer is laminated on the reinforcing fiber reinforcing resin layer, the physical properties of the molded product cannot be partially controlled.

Therefore, an object of the present invention is to provide an FRP molded product and a method for producing the same, which simultaneously satisfy high strength, high elastic modulus, and excellent impact resistance.

As a result of diligent studies to solve the above problems, the present inventors have arranged cushioning materials in a regular or irregular pattern in a plan view on at least one surface of the fiber base material containing the fibers. When the obtained cushioning fiber material is coated with a resin, it has been found that the obtained FRP molded product simultaneously satisfies high strength, high elastic modulus, and excellent impact resistance, and completed the present invention.

That is, the FRP molded product of the present invention contains a cushioning fiber material and a coating material for coating the cushioning fiber material, and the cushioning fiber material is a fiber-containing fiber base material and at least one of the fiber base materials. The covering material contains a curable resin , the fiber contains a reinforcing fiber, and the fiber group contains a cushioning material arranged in a regular or irregular pattern in a plan view. The occupancy rate of the cushioning material in the portion of the material in which the cushioning material is arranged is 10 to 90% . The FRP molded product of the present invention preferably contains a plurality of cushioning fiber materials and is preferably in the form of a stack of the plurality of cushioning fiber materials. The reinforcing fiber preferably contains carbon fiber. The fiber base material preferably contains a cloth, and the cloth preferably contains one or more selected from the group consisting of a woven fabric, a knitted fabric, and a non-woven fabric. The cushioning material preferably has shock absorbing properties. The pattern is preferably composed of a plurality of scattered projectiles, and the shape of the projectiles is preferably either a circular shape or a polygonal shape in a plan view. The pattern is preferably formed in a net shape, and the mesh of the pattern formed in the net shape is preferably in either a circular shape or a polygonal shape. The curable resin preferably contains at least one selected from the group consisting of epoxy resin, urethane resin, and melamine resin.

The method for producing an FRP molded product of the present invention is a method for producing an FRP molded product of the present invention, in which a cushioning material is regularly or in plan view is applied to at least one surface of a fiber base material containing a reinforcing fiber. The cushioning in a portion of the fiber base material on which the cushioning material is arranged includes a step of arranging the cushioning fiber material in an irregular pattern to obtain a cushioning fiber material and a step of coating the cushioning fiber material with a curable resin. The occupancy rate of the material is 10 to 90% .

According to the present invention, it is possible to provide an FRP molded product and a method for producing the same, which simultaneously satisfy high strength, high elastic modulus, and excellent impact resistance.

FIG. 1 is a schematic plan view showing an example of an FRP molded product of the present invention. FIG. 2 is a schematic cross-sectional view taken along the line AA'of the FRP molded product of FIG. FIG. 3 is a schematic view showing a pattern in the CFRP molded product of Example 1-1. FIG. 4 is a schematic view showing a pattern in the CFRP molded product of Example 1-11. FIG. 5 is a schematic view showing a pattern in the CFRP molded product of Example 1-12. FIG. 6 is a schematic view showing a pattern in the CFRP molded product of Example 1-13. FIG. 7 is a schematic view showing a pattern in the CFRP molded product of Example 1-14. FIG. 8 is a photograph of a CFRP molded product of Example 2, Comparative Example 2, and Reference Example after the drop weight impact test.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. The present invention is not limited to the following description, and can be variously modified and implemented within the scope of the gist thereof. Further, in the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown.

[1. FRP molded product]
The FRP molded product of the present embodiment includes a cushioning fiber material and a coating material for coating the cushioning fiber material, and the cushioning fiber material includes a fiber-containing fiber base material and at least one of the fiber base materials. A cushioning material arranged on a surface in a regular or irregular pattern (hereinafter, also referred to as “specific pattern”) in a plan view is included, and the covering material contains a resin. An example of the FRP molded product of this embodiment is shown in FIGS. 1 and 2. FIG. 1 is a plan view schematically showing the FRP molded product (however, the buffer fiber material 3 described later is seen through for the sake of explanation), and FIG. 2 is the line AA'of FIG. It is a cross-sectional view which shows the cross section by. The FRP molded product 100 shown in FIGS. 1 and 2 includes five cushioning fiber materials 3 having a sheet-shaped fiber base material 1 containing fibers and a cushioning material 2 arranged on one side of the fiber base material 1. The five cushioning fiber materials 3 are stacked in a direction orthogonal to one side, with one side as the upper surface and the surface opposite to one side as the lower surface, and the covering material 4 forms the stacked five cushioning fiber materials 3. It is covered. The cushioning material 2 is composed of a plurality of projecting bodies 5 having a circular shape in a plan view, and the plurality of projecting bodies 5 are uniformly pointed on one surface of the fiber base material 1 at a predetermined distance from each other. It exists and forms a polka dot pattern in a plan view.

When a soft synthetic resin foam layer is laminated on a reinforced fiber reinforced resin layer like the FRP molded product described in Patent Document 1, the synthetic resin foam layer plays a role as a cushioning material for absorbing impact, and FRP is mainly used. The impact resistance of the molded product can be improved. However, in this FRP molded product, the main reason is that the synthetic resin foam layer having low strength and elastic modulus is arranged on the surface of the reinforcing fiber reinforcing resin layer having high strength and elastic modulus as a whole. , The strength and elastic modulus of the FRP molded product as a whole are not sufficient. Therefore, in the FRP molded product described in Patent Document 1, it is necessary to form a reinforcing material for reinforcing the strength and a backing layer for fixing the reinforcing material. On the other hand, in the FRP molded product of the present invention, a cushioning material for cushioning impact is arranged on a part of one side of the fiber base material while forming a specific pattern shape, and the covering material covers this form. Mainly because of this, it is possible to satisfy high strength, high elastic modulus, and excellent impact resistance at the same time. Therefore, the FRP molded product of the present invention can improve the impact resistance while maintaining high strength and elastic modulus by a simple configuration without providing a member for reinforcing the strength.

[1-1. Buffer fiber material]
The cushioning fiber material includes a fiber base material and a cushioning material arranged in a specific pattern on at least one surface of the fiber base material.

[(A) Fiber base material]
The fiber base material is, for example, a sheet-like base material containing fibers. The fiber is not particularly limited, and examples thereof include a reinforcing fiber usually used as a material for an FRP molded product. Examples of the reinforcing fiber include inorganic fiber (for example, glass fiber and carbon fiber) and organic fiber (for example, aramid fiber and polyester fiber). These reinforcing fibers may be used alone or in combination of two or more. Among these, the reinforcing fiber is preferably an inorganic fiber, more preferably a carbon fiber. The term "carbon fiber" as used herein refers to a fiber containing carbon as a main component, which is obtained by heating and decomposing in an inert gas, and is also referred to as a carbonized fiber.

Carbon fiber is particularly useful as a material for FRP molded products because it has relatively high strength, high elastic modulus, and excellent lightness, but carbon fiber is used because it is a fragile and brittle material. The FRP molded product (CFRP molded product) has a problem that its use is limited. On the other hand, the FRP molded product of the present embodiment has excellent impact resistance, and even if carbon fiber is used as the fiber, brittle fracture can be sufficiently suppressed, so that the FRP molded product has excellent characteristics (high strength). , High elastic modulus, and light weight) can be applied to a wide range of applications.

The type of carbon fiber is not particularly limited, and examples thereof include PAN-based carbon fiber, rayon-based carbon fiber, and pitch-based carbon fiber. These carbon fibers may be used alone or in combination of two or more. Among these, PAN-based carbon fibers are preferable from the viewpoint of productivity.

The tensile strength (MPa) of the carbon fiber is not particularly limited, but is, for example, 2500 to 6500 MPa, preferably 3000 to 5000 MPa, preferably 3000 to 4000 MPa, from the viewpoint of more effectively and surely exerting the action and effect of the present invention. Is more preferable. The tensile elastic modulus (GPa) of the carbon fiber is not particularly limited, but is, for example, 200 to 650 GPa, and may be 200 to 400 GPa from the viewpoint of more reliably and effectively exerting the action and effect of the present invention. It is preferably 200 to 300 GPa, more preferably 200 to 300 GPa. The tensile strength and tensile elastic modulus of the carbon fiber can be measured by the method of JIS R 7606-2000. Further, the tensile strength and the tensile elastic modulus of the carbon fiber referred to here refer to the tensile strength and the tensile elastic modulus measured at a temperature of 23 ° C., respectively.

The number of filaments of the carbon fiber is not particularly limited, and is, for example, 1000 to 50,000, preferably 2000 to 24000 from the viewpoint of more effectively and surely achieving the action and effect of the present invention, and 3000 to 6000. Is more preferable.

The fiber base material is not particularly limited as long as it has a surface (for example, a flat surface) on which the cushioning material can be arranged in a specific pattern, and examples thereof include a sheet-like form, which further enhances the effects of the present invention. From the viewpoint of effective and reliable performance, the sheet-like form is preferable. When the fiber base material is in the form of a sheet, the fiber base material preferably contains a cloth and / or paper, and more preferably contains a cloth, from the viewpoint that the cushioning material can be arranged more stably. As used herein, the term "cloth" refers to a concept that includes a cloth-like form. The fabric includes, for example, at least one selected from the group consisting of woven fabrics, knitted fabrics (knits), non-woven fabrics, and felts, and woven fabrics, knitted fabrics (for example, weft knitting and knitting) from the viewpoint that the cushioning material can be arranged more stably. It is preferable to contain at least one selected from the group consisting of warp knitting) and a non-woven fabric, and it is more preferable to include a woven fabric. Examples of the structure of the woven fabric include a Mihara structure (plain weave, twill weave, and Akiko weave), a variable structure, and a multiple structure, and the structure is a Mihara structure from the viewpoint of more effectively and surely exerting the action and effect of the present invention. Is preferable, and a plain weave structure is more preferable.

[(B) Cushioning material]
As used herein, the term "cushioning material" refers to, for example, an impact cushioning material (impact cushioning material) for cushioning or cushioning an external impact. The cushioning material preferably has impact absorption characteristics (for example, rubber elasticity) from the viewpoint of further improving impact resistance.

The cushioning material is preferably in a solid and solid form from the viewpoint of more effectively and surely exerting the action and effect of the present invention. The solid form referred to here may be a form in which no gap is formed inside, and there are a few gaps or holes inside (for example, less than 50%, preferably 30% or less, more preferably 10% or less). It may be in a formed form (for example, a porous form).

The cushioning material contains, for example, a soft resin having impact absorbing properties (for example, rubber elasticity) in order to cushion or cushion an external impact. Examples of the soft resin include olefin resins, polyester resins, polyamide resins, urethane resins, and synthetic rubbers, and thermoplastic elastomers (for example, olefin elastomers, polyester elastomers, polyamide elastomers, and styrene elastomers). Examples thereof include thermoplastic resins (elastomers), which may be in a semi-cured or cured state. These thermoplastic resins can be used alone or in combination of two or more. Among these, the thermoplastic resin is preferably synthetic rubber from the viewpoint of more effectively and surely exerting the action and effect of the present invention. Examples of the synthetic rubber include acrylic rubber, olefin rubber, diene rubber, urethane rubber, silicon rubber and fluorine rubber, and among these, the action and effect of the present invention can be more effectively and reliably exerted. From the viewpoint, acrylic rubber is preferable. These thermoplastic resins may be prepared by a known method, or commercially available products may be used. Commercially available products include Seikaplen LX10, LX-20, LX-30 White, LX-M1, LX-M2, LX-M3 White, ER-111C, ER-222M, ER-333W, SR-500W (K), SR- Examples thereof include 510 (K), UD-900 White, and UD-910 (all of which are products manufactured by Dainichiseika Kogyo Co., Ltd.).

The cushioning material may contain a conventional additive, if necessary. Examples of the additive include an impact resistance improver, a viscosity modifier, a thickener, a colorant, a stabilizer, an antistatic agent, a flame retardant, a filler, a preservative, and an antibacterial agent.

In the cushioning fiber material of the present embodiment, the cushioning material may be arranged on at least one surface of the fiber base material, and may be arranged on the other surface (for example, the surface opposite to one side).

In the cushioning fiber material of the present embodiment, the cushioning material is arranged on one surface of the fiber base material in a regular or irregular pattern. When the pattern is composed of a plurality of scattered protrusions, the "regular pattern" means that the protrusions are arranged with a certain regularity, and the "irregular pattern" is used. "" Means that a plurality of projectiles are arranged irregularly or randomly. On the other hand, when the pattern is formed in a network, the "regular pattern" means that the mesh of the pattern formed in the network is arranged with a certain regularity, and is an "irregular pattern". Means that the mesh of the pattern is arranged irregularly or randomly.
say.

In the cushioning fiber material of the present embodiment, the cushioning material does not necessarily have to be arranged in a regular or irregular pattern over one surface of the fiber substrate, and is not necessarily arranged on a part of the surface, that is, partially. It may be arranged in a regular or irregular pattern.

The pattern is preferably composed of a plurality of interspersed projecting bodies (for example, rod-shaped bodies) from the viewpoint of further increasing the strength and elastic modulus. The projecting shape may be, for example, a block shape, and the cross-sectional shape thereof is not particularly limited, and may be, for example, a rectangular shape (for example, a trapezoidal shape and a rectangular shape) or a concave shape. The shape of the projecting body in a plan view is more preferably either a circular shape or a polygonal shape. The circular shape includes, for example, a perfect circle shape, an elliptical shape, and an egg shape, and may be a shape in which a part of these is cut out (for example, a semicircular shape and a crescent shape). Examples of the polygonal shape include a triangular shape, a quadrangular shape, a rhombic shape, a pentagonal shape, a hexagonal shape, a pentagonal star shape, and a hexagonal star shape. The plurality of projecting bodies may have the same shape as each other, may have two or more types of shapes different from each other, or may be a combination of a circular shape and a polygonal shape.

The pattern is preferably formed in a net shape from the viewpoint of further increasing the strength and elastic modulus, and the mesh of the pattern formed in a net shape is either a circular shape or a polygonal shape. Is preferable. The circular shape includes, for example, a perfect circle shape, an elliptical shape, and an egg shape, and may be a shape in which a part of these is cut out (for example, a semicircular shape and a crescent shape). Examples of the polygonal shape include a triangular shape, a quadrangular shape, a rhombic shape, a pentagonal shape, a hexagonal shape, a pentagonal star shape, and a hexagonal star shape. The meshes of the plurality of patterns may have the same shape as each other, may have two or more types of shapes different from each other, or may be a combination of a circular shape and a polygonal shape.

The pattern may be composed of a plurality of interspersed protrusions or may be formed in a mesh pattern, but the pattern may be composed of a plurality of interspersed protrusions to have higher strength and elastic modulus. It is preferable because it tends to be possible.

The occupancy rate of the cushioning material (the ratio of the area where the cushioning material is arranged to the entire area of one surface of the fiber base material) is not particularly limited, and is, for example, 5 to 95%, and has high strength and high elastic modulus. From the viewpoint of further improving the balance between the above and the excellent impact resistance, the content is preferably 10 to 90%, more preferably 20 to 80%, still more preferably 30 to 70%.

The thickness (height) of the cushioning material is not particularly limited, and is, for example, 50 to 300 μm, preferably 80 to 200 μm, preferably 80 to 200 μm, from the viewpoint of more effectively and surely exerting the action and effect of the present invention. It is more preferably 150 μm.

The number of cushioning fiber materials in the FRP molded product of the present embodiment may be one or a plurality, but high strength, high elastic modulus and excellent impact resistance are further improved in a well-balanced manner. From the viewpoint of the above, it is preferable that a plurality of cushioning fiber materials are contained and a plurality of cushioning fiber materials are stacked.

[1-2. Covering material]
The FRP molded product of the present embodiment includes a coating material for coating the cushioning fiber material. As used herein, "coating a buffer fiber material" means, for example, covering the entire outer surface of one buffer fiber material or a plurality of stacked buffer fiber materials. The covering material may not be impregnated in the gaps formed in the cushioning fiber material and the gaps formed by stacking the cushioning fiber materials, but from the viewpoint of more effectively and surely exerting the action and effect of the present invention. It is preferable to impregnate these gaps.

The covering material contains a resin. The term "resin" as used herein also includes, for example, a resin in a semi-cured state and a resin in a cured state.

Examples of the resin include molding resins used for molding. Examples of the molding resin include curable resins (eg, epoxy resins, phenol resins, urethane resins, melamine resins, and unsaturated polyester resins) that are reactively cured by a curing agent or the like or cured by heating. .. From the viewpoint of more effectively and surely exerting the action and effect of the present invention, the molding resin is preferably a curable resin (for example, epoxy resin, urethane resin, and melamine resin) that is reaction-cured by a curing agent, and is preferably an epoxy resin. It is more preferable to have.

[2. Manufacturing method of FRP molded products]
In the method for producing an FRP molded product of the present embodiment, a cushioning material is placed on at least one surface of a fiber base material containing fibers in a regular or irregular pattern in a plan view (hereinafter, also referred to as “specific pattern”). It includes a step (arrangement step) of arranging the cushioning fiber material in (referred to) to obtain a cushioning fiber material, and a step of coating the cushioning fiber material with a resin (coating step). In the method for manufacturing an FRP molded product of the present embodiment, a cushioning material that cushions an impact is placed on a part of one side of the fiber base material so as to form a specific pattern by the placement step, and these are placed as a covering material. It is possible to manufacture an FRP molded product that simultaneously satisfies high strength, high elastic modulus, and excellent impact resistance, mainly because of the coating.

In a general FRP molded product, it is often required to control the physical properties (for example, strength, impact resistance, and elastic modulus) of only a part of the molded product. For example, in the sports field and the leisure field, a racket (for example, a tennis racket), a golf shaft, a fishing rod, or the like requires bending (or bending) to a predetermined portion, and therefore it is necessary to form a portion or portion having a low elastic modulus. There is. In this respect, in the present invention, for example, a cushioning fiber material in which a cushioning material is arranged at a desired portion of a fiber base material is obtained by an arrangement step, and a cushioning fiber material in which a cushioning material is arranged in a predetermined portion is used as a resin by a coating step. By coating with, the elastic modulus can be lowered only in the portion where the cushioning material of the obtained FRP molded product is arranged. As described above, by using the method for producing an FRP molded product of the present invention, it is possible to produce an FRP molded product whose physical properties are partially controlled.

Further, in a general FRP molded product, in order to expand its use, it is often required to improve the design such as increasing the variation of the pattern or the pattern. Here, in order to improve the design, for example, it is conceivable to change the structure of the fiber base material (for example, the woven fabric structure), but there is a limit to the pattern or pattern that can be expressed by the structure, and the desired pattern is used. Alternatively, it is difficult to obtain a fiber base material (for example, a woven fabric) capable of forming a pattern. In this respect, in the present invention, the cushioning material can be arranged in a desired pattern by the arrangement step. Therefore, if the cushioning material having the desired pattern formed by the coating step is coated with a resin (for example, a transparent resin), A desired pattern or pattern can be imparted to the obtained FRP molded product. As described above, by using the method for producing an FRP molded product of the present invention, it is possible to produce an FRP molded product having excellent designability such as being able to impart a desired pattern or pattern.

Further, Patent Document 1 has a problem that the strength and elastic modulus are not sufficient due to the laminating the synthetic resin foam layer over the entire surface of the reinforcing fiber reinforcing resin layer. Therefore, in the manufacturing method of Patent Document 1, it is necessary to form a reinforcing material and a backing layer, but in this case, it is not possible to manufacture a molded product having a thin thickness due to an increase in the number of layers. In this respect, in the present invention, the cushioning material may be arranged only on a desired portion of one surface of the fiber base material, and it is not necessary to arrange the cushioning material on the entire surface. As a result, it is not necessary to form a reinforcing material and a lining layer because the decrease in strength and elastic modulus due to the arrangement of the cushioning material can be suppressed (reduced). Therefore, by using the method for producing an FRP molded product of the present invention, the thickness of the molded product can be reduced.

As described above, in the method for producing an FRP molded product of the present embodiment, it is possible to impart high strength, high elastic modulus, and excellent impact resistance to the obtained FRP molded product, and it is possible to partially control the physical properties. Furthermore, excellent designability can be imparted, and the thickness of the obtained molded product can be reduced.

[1. Placement process]
In the arranging step, the cushioning material is arranged on at least one surface of the fiber base material containing the fiber in a regular or irregular pattern (hereinafter, also referred to as “specific pattern”) in a plan view to cushion the fibers. Obtain fiber material.

As the fiber base material used in the arranging step, the above-mentioned [1-1. Examples of the fiber base material exemplified in the section of [Cushioning fiber material] are mentioned, and the preferable fiber base material is the above-mentioned [1-1. Preferred fiber base material exemplified in the section of [Cushioning fiber material] can be mentioned. The fiber base material is the above-mentioned [1-1. The fiber base material exemplified in the section of [Cushioning fiber material] may be used as it is, or may be used in the form of a so-called prepreg in which the fiber base material is impregnated with a resin.

The method of arranging the cushioning material on at least one surface of the fiber base material in a specific pattern is not particularly limited, and examples thereof include a method of transferring the components constituting the cushioning material to the fiber base material. The method for transferring the components constituting the cushioning material to the fiber substrate is not particularly limited, and examples thereof include known printing methods, and specific printing methods include a screen printing method (screen printing method) and gravure. Examples thereof include a printing method, a concave printing method, an offset printing method, a typographic printing method, an inkjet printing method, and a flexo printing method. Among these, the printing method is preferably a screen printing method from the viewpoint that the cushioning material can be stably transferred by the fiber base material.

(Screen printing method)
An example of a method of transferring the components constituting the cushioning material to a predetermined portion on the surface of the fiber substrate by using the screen printing method will be described. A photosensitive agent is applied to the screen mesh, and the area of the screen mesh (hereinafter referred to as “specific area”) corresponding to the area of the fiber base material on which the cushioning material is placed is masked and exposed. Next, the photosensitive agent applied to the masked unexposed area (specific area) is removed by washing with water to produce a screen mesh in which a pattern corresponding to the specific pattern is formed in the specific area. Next, with the screen mesh prepared on one side of the fiber base material placed, the components constituting the cushioning material are applied on the screen mesh, and if necessary, pressed with a squeegee to press the surface of the fiber base material. The components constituting the cushioning material can be transferred to a predetermined portion.

As the screen mesh used in the screen printing method, a commonly used screen mesh can be used. The material of the screen mesh is not particularly limited, and examples thereof include a polyester material and a stainless steel material. The mesh size of the screen mesh is not particularly limited and may be, for example, about 10 to 100 meshes. Further, as the photosensitive agent, a photosensitive agent usually used in the screen printing method can be used.

In the screen printing method, the components constituting the cushioning material are transferred to a predetermined portion on the surface of the fiber substrate, and then the components are semi-cured or cured by heating using a known heating means as necessary. You may. The heating temperature and the heating time can be appropriately selected depending on the components to be used, and may be, for example, about 100 to 150 ° C. or about 10 seconds to 10 minutes.

The component constituting the cushioning material (hereinafter, also referred to as “buffer material component”) is not particularly limited, and examples thereof include a component capable of cushioning or mitigating an external impact, and [(B) cushioning material. ] The soft resin exemplified in the section can be mentioned. When a printing method such as a screen printing method is used, 0.1 to 500 Pa. It is preferable to have a viscosity of s. The amount of the cushioning material component used is not particularly limited, and can be appropriately selected depending on the fiber base material used, the occupancy rate, and the like.

[2. Coating process]
In the coating step, the cushioning fiber material obtained in the placement step is coated with a resin to obtain an FRP molded product. The method of coating the buffer fiber material with the resin is not particularly limited, and usually, a method of coating the fiber base material with the resin or impregnating the fiber base material in order to obtain an FRP molded product can be used, but the pattern is From the viewpoint of stable coating so as not to collapse, resin impregnation molding method (RTM method), vacuum resin impregnation molding method (VaRTM molding method), autoclave molding method, hand lay-up molding method, press molding method, and sheet winding molding method. It is preferable to use either one, and it is preferable to use either the resin impregnation molding method or the autoclave molding method.

(Resin impregnation molding method and vacuum resin impregnation molding method)
In the resin impregnation molding method, for example, a cushioning fiber material is impregnated with a resin and the resin is cured to form the molding. As a result, an FRP molded product in which the cushioning fiber material is coated with a resin can be obtained. In the vacuum resin impregnation molding method, a cushioning fiber material is placed in a predetermined mold, the mold is filled with resin, and then vacuum suction is performed for molding. These curing conditions are not particularly limited, and for example, the curing temperature may be about 80 to 180 ° C., and the curing time may be about 30 minutes to 3 hours. Examples of the resin used include [1-2. Examples of the resin exemplified in the section of "Coating material" may be used, and a known curing agent corresponding to each resin may be blended with the resin. The compounding ratio (based on mass) of the curing agent to the resin is not particularly limited, and may be, for example, about 0.01 to 1.00.

(Autoclave molding method)
In the autoclave molding method, for example, a cushioning material is placed in a state where the fiber base material is impregnated with the resin, and the obtained cushioning fiber material is impregnated and cured in the autoclave. As a result, an FRP molded product in which the cushioning fiber material is coated with a resin can be obtained. The impregnation curing conditions are not particularly limited, and may be, for example, a pressure of 1 to 10 kg / cm ² , a temperature of 80 to 180 ° C., and a curing time of about 30 minutes to 3 hours. Examples of the resin used include [1-2. Examples of the resin exemplified in the section of "Coating material" may be used, and a known curing agent corresponding to each resin may be blended with the resin. The compounding ratio (based on mass) of the curing agent to the resin is not particularly limited, and may be, for example, about 0.01 to 1.00.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Screen printing method]
In this example and the comparative example, the screen printing method was used to print the water-based acrylic resin on the plain weave fabric. The screen mesh used in the screen printing method was prepared as follows. That is, a photosensitive agent (Murakami Co., Ltd. product "SP7000") is applied to a screen mesh in which polyester threads are woven into 50 mesh, a specific area of the screen mesh is masked and exposed, and an unexposed area (specific area) is exposed. By removing the applied photosensitive agent by washing with water, a screen mesh in which a predetermined print pattern was formed in a specific area was produced. A plurality of screen meshes were produced so as to correspond to each of the examples and comparative examples described later. The thickness (height) of each screen mesh to which the photosensitive agent was attached was 140 μm. Next, by applying the water-based acrylic resin on the screen mesh with the screen mesh placed on one side of the plain weave fabric, the water-based acrylic resin was adhered to the portion corresponding to the specific area on one side of the plain weave fabric. ..

[Example 1]
[Example 1-1]
Water-based acrylic on one side of a plain woven fabric (150 x 100 mm (when used)) of carbon fiber (Toho Tenax Co., Ltd. product "TENAX (registered trademark) HTA40, number of filaments 3000)" by screen printing method using screen mesh. The resin (Dainichiseika Kogyo Co., Ltd. product "New Lacquitine Color Seikaprene LX-20") was printed. Next, the plain weave fabric on which the water-based acrylic resin was printed was heat-treated at 130 ° C. for 3 minutes using a heat treatment device (product name "NAP-600" manufactured by Asahi Textile Machinery Co., Ltd.), and the water-based acrylic resin was printed. Was cured to prepare a cushioning fiber material. In this cushioning fiber material, in the plan view of the plain weave fabric, the cured water-based acrylic resin has a net-like (lattice-like) pattern in which the mesh is a regular square shape, as shown in FIG. 3, and covers the entire one side of the plain weave fabric. It is arranged over. Each mesh is arranged so as to be evenly spaced. The length of one side of the mesh of the lattice is 1.0 mm, the width of the lattice is 2.5 mm, and the occupancy rate (the ratio of the arranged area of the cured water-based acrylic resin to the entire area of one side of the plain weave fabric) is It was 70%. A total of 8 sheets of this cushioning fiber material were produced.
Each of the prepared buffer fiber materials was stacked in a direction orthogonal to the above-mentioned one side, with one side on which the water-based acrylic resin was arranged as the upper surface and the side opposite to the one side as the lower surface. Epoxy resin (product "RT-400" manufactured by Nissin Resin Co., Ltd.) and curing agent (modified aliphatic polyamine, product "HX-18" manufactured by Nissin Resin Co., Ltd.) are mixed with eight stacked cushion fiber materials. The material was impregnated and cured by a vacuum resin impregnation molding method (VaRTM method), and the buffer fiber material was coated with a cured epoxy resin. The compounding ratio (weight) of the curing agent to the epoxy resin in the compound was 1: 0.2, and the curing conditions were left at room temperature overnight and then treated at 100 ° C. for 1 hour. In this way, a plate-shaped CFRP molded product in which the cushioning fiber material was coated with the coating material was produced.

[Example 1-2]
In the same manner as in Example 1-1, another screen mesh was used to prepare a cushioning fiber material having a grid mesh having a side length of 0.5 mm and a grid width of 1.5 mm. A plate-shaped CFRP molded product was produced.

[Example 1-3]
A plate-shaped CFRP molded product was produced in the same manner as in Example 1-1, except that a cushioning fiber material having a lattice width of 6.1 mm and an occupancy rate of 30% was produced using another screen mesh. Made.

[Example 1-4]
In the same manner as in Example 1-3, another screen mesh was used to prepare a cushioning fiber material having a grid mesh having a side length of 0.5 mm and a grid width of 3.7 mm. A plate-shaped CFRP molded product was produced.

[Example 1-5]
A plate-shaped CFRP molded product was produced in the same manner as in Example 1-1, except that a cushioning fiber material having a lattice width of 5 mm and an occupancy rate of 40% was produced using another screen mesh. ..

[Example 1-6]
Using another screen mesh, a plate-shaped material was produced in the same manner as in Example 1-5, except that a cushioning fiber material having a grid mesh having a side length of 0.5 mm and a grid width of 3 mm was produced. A CFRP molded product was produced.

[Example 1-7]
A plate-shaped CFRP molded product was produced in the same manner as in Example 1-1, except that a cushioning fiber material having a lattice width of 3.6 mm and an occupancy rate of 50% was produced using another screen mesh. Made.

[Example 1-8]
In the same manner as in Example 1-7, another screen mesh was used to prepare a cushioning fiber material having a grid mesh having a side length of 0.5 mm and a grid width of 2.2 mm. A plate-shaped CFRP molded product was produced.

[Example 1-9]
A plate-shaped CFRP molded product was produced in the same manner as in Example 1-1, except that a cushioning fiber material having a lattice width of 3 mm and an occupancy rate of 60% was produced using another screen mesh. ..

[Example 1-10]
In the same manner as in Example 1-9, another screen mesh was used to prepare a cushioning fiber material having a grid mesh having a side length of 0.5 mm and a grid width of 1.8 mm. A plate-shaped CFRP molded product was produced.

[Example 1-11]
Using another screen mesh, the arrangement pattern of the cushioning fiber material is replaced with a grid pattern, and as shown in FIG. 4, a circular mesh pattern arranged in an equilateral triangle (“circle” in Table 1). The plate-like shape is the same as in Example 1-1, except that the diameter of the circular mesh is 1.0 mm and the distance between the centers of the circular mesh is about 1.5 mm. A CFRP molded product was produced.

[Example 1-12]
Using another screen mesh, the arrangement pattern of the cushioning fiber material is replaced with a grid pattern, and as shown in FIG. 5, a regular triangle shape with a small mesh and an inverted regular triangle shape with a large mesh are alternately arranged in the horizontal direction. The combined mesh pattern (referred to as "triangle" in Table 1) is used, the length of one side of the small regular triangular mesh is about 1.8 mm, and the length of one side of the large inverted regular triangular mesh is set. A plate-shaped CFRP molded product was produced in the same manner as in Example 1-1 except that the distance between the regular triangular mesh and the inverted regular triangular mesh was 1.0 mm.

[Example 1-13]
Using another screen mesh, the arrangement pattern of the cushioning fiber material is replaced with a grid-like pattern, and as shown in FIG. 6, a net-like (honeycomb-like) pattern in which the mesh is a regular hexagonal shape (in Table 1, in Table 1). It is described as "hexagon"), and the length of one side of the regular hexagonal mesh is about 1.0 mm, and the distance between the regular hexagonal meshes is 1.0 mm. In the same manner, a plate-shaped CFRP molded product was produced.

[Example 1-14]
Using another screen mesh, the arrangement pattern of the cushioning fiber material is replaced with a grid pattern, and as shown in FIG. 7, circular blocks are uniformly pointed at a predetermined distance from each other in a plan view. Examples except that the existing polka dot pattern (described as "polka dot pattern" in Table 1), the diameter of the circular block body is 1.0 mm, and the distance between the block bodies is about 0.2 mm. A plate-shaped CFRP molded product was produced in the same manner as in 1-1.

[Comparative Example 1-1]
Eight plain weave fabrics of Example 1-1 were stacked and subjected to impregnation curing by the VaRTM method using the formulation of Example 1-1. The curing conditions were the same as in Example 1-1. As a result, a plate-shaped CFRP molded product in which the plain weave fabric was covered with a covering material was produced.

[Comparative Example 1-2]
A plate was produced in the same manner as in Example 1-1, except that a cushioning fiber material having an occupancy rate of 100%, that is, a cushioning fiber material in which the cushioning material was arranged on the entire surface of one side of the plain weave fabric was produced by using another screen mesh. A CFRP molded product in the shape of a shape was produced.

(Measurement of bending strength and flexural modulus)
The obtained CFRP molded products (length 100 mm × 10 mm) of Examples 1-1 to 1-14, Comparative Example 1-1, and Comparative Example 1-2 were subjected to a three-point flexural modulus based on JIS K 7074. Gpa) and flexural modulus (MPa) were evaluated. The evaluation results are shown in Table 1.

[Example 2]
Sheet-shaped prepreg (Toray Industries, Inc. product "TORAYCA (registered trademark)), which is a carbon fiber plain woven fabric (150 x 100 mm (when used)) impregnated with thermosetting resin by a screen printing method using a screen mesh. F6343B-05P ”) was printed with a water-based acrylic resin (Dainichi Seika Kogyo Co., Ltd. product“ New Lacctimine Color Seikaprene LX-20 ”). Next, the sheet-shaped prepreg printed with the water-based acrylic resin was heat-treated at 100 ° C. for 10 seconds using a heat treatment device (product name "NAP-600" manufactured by Asahi Textile Machinery Co., Ltd.), and the water-based acrylic resin was used. A cushioning fiber material was produced by curing the resin. In this cushioning fiber material, in the plan view of the sheet-shaped prepreg, the cured water-based acrylic resin is arranged in a lattice-like pattern on one side of the sheet-shaped prepreg, and the length of one side of the mesh of the lattice is 1.0 mm. The width of the lattice was 2.5 mm, and the occupancy rate (the ratio of the arrangement area of the cured water-based acrylic resin to the entire area of one side of the plain woven fabric) was 70%. A total of 8 cushion fiber materials were prepared.
The prepared buffer fiber materials were stacked in a direction perpendicular to one side, with one side as the upper surface and the side opposite to one side as the lower surface. The eight stacked cushion fiber materials were impregnated and cured by the autoclave method using an autoclave (“DL-2-1” manufactured by Hanyuda Iron Works Co., Ltd.), and the buffer fiber material was cured with an epoxy resin. Covered. The impregnated curing conditions were a pressure of 6 kg / cm ² , a temperature of 80 ° C. for 0.5 hours, and then a pressure of 6 kg / cm ² , a temperature of 135 ° C. for 1.5 hours. As a result, a plate-shaped CFRP molded product in which the cushioning fiber material was coated with the coating material was produced.

[Comparative Example 2]
Eight sheet-shaped prepregs of Example 2 were stacked, and the autoclave of Example 2 was used to impregnate and cure the prepreg by the autoclave method. As a result, a plate-shaped CFRP molded product in which the plain weave fabric was covered with a covering material was produced.

[Reference example]
Using another screen mesh, a cushioning fiber material having an occupancy rate of 100%, that is, a cushioning fiber material in which the cushioning material is arranged on the entire surface of one side of the plain weave fabric, is formed in the same manner as in Example 2. A CFRP molded product was produced.

(Drop type impact test)
Using a drop-weight tester (product name "CEAST 9310" manufactured by INSTRON), a striker with a mass of 3.09 kg and a diameter of 20 mm is shown from a height of 500 mm. As shown in FIG. 8, a part of the surface of the CFRP molded product of Comparative Example 2 was brittlely fractured, but the CFRP molded product of Example 2 was observed to have surface fracture like the CFRP molded product of the reference example. It was not used and had excellent impact resistance.

Since the FRP molded product of this embodiment has high strength, high elastic modulus, and excellent impact resistance, it can be used in a wide range of applications such as household goods, aerospace, mobile objects, sports, and home appliances. Can be used.

1 ... Fiber base material, 2 ... Cushioning material, 3 ... Cushioning fiber material, 4 ... Coating material, 5 ... Projective body, 100 ... FRP molded product.

Claims (11)

A cushioning fiber material and a covering material for coating the cushioning fiber material are included.
The cushioning fiber material
It comprises a fiber substrate containing fibers and a cushioning material arranged on at least one surface of the fiber substrate in a regular or irregular pattern in plan view.
The coating material contains a curable resin and is
The fibers contain reinforcing fibers and
An FRP molded product in which the occupancy rate of the cushioning material in the portion of the fiber substrate on which the cushioning material is arranged is 10 to 90% . The FRP molded product according to claim 1, wherein the FRP molded product contains a plurality of the cushioning fiber materials and is in the form of stacking the plurality of cushioning fiber materials. The FRP molded product according to claim 1 or 2, wherein the reinforcing fiber contains carbon fiber. The FRP molded product according to any one of claims 1 to 3, wherein the fiber base material contains a cloth. The FRP molded product according to claim 4, wherein the fabric contains at least one selected from the group consisting of a woven fabric, a knitted fabric, and a non-woven fabric. The cushioning material has shock absorption characteristics and
The reinforcing fiber contains carbon fiber and contains
The curable resin contains at least one selected from the group consisting of epoxy resin, urethane resin, and melamine resin.
The FRP molded product according to any one of claims 1 to 5. The FRP molded product according to any one of claims 1 to 6, wherein the pattern is composed of a plurality of scattered protrusions. The FRP molded product according to claim 7, wherein the shape of the projecting body is either a circular shape or a polygonal shape in a plan view. The FRP molded product according to any one of claims 1 to 6, wherein the pattern is formed in a net shape. The FRP molded product according to claim 9, wherein the mesh of the pattern formed in the mesh shape is either a circular shape or a polygonal shape. The method for producing an FRP molded product according to any one of claims 1 to 10.
A step of arranging the cushioning material in a regular or irregular pattern in a plan view on at least one surface of the fiber base material containing the reinforcing fiber to obtain the cushioning fiber material.
The step of coating the cushioning fiber material with a curable resin is included.
A method for producing an FRP molded product, wherein the occupancy rate of the cushioning material in the portion of the fiber base material on which the cushioning material is arranged is 10 to 90% .

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