JP7220004B2 - Fiber-reinforced resin composite molding and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fiber-reinforced resin composite molded article and a method for producing the same.

BACKGROUND ART Conventionally, fiber-reinforced resin molded articles have been used in a wide range of industrial fields such as sports, leisure, and aircraft because of their high strength and high rigidity.
As a method for producing a fiber-reinforced resin molded article, a method of compression-molding a prepreg in which reinforcing fibers are impregnated with a thermosetting resin, a sheet molding compound, or the like is employed in many fields.

Since the prepreg uses long fibers as reinforcing fibers, it is possible to obtain a molded product with high strength and high rigidity, but it is difficult to form it into a complicated shape. On the other hand, since sheet molding compound uses short fibers as reinforcing fibers, the strength of the molded product is low, but it has excellent fluidity during molding and can be easily formed into complex shapes such as ribs and bosses.

Further, in order to incorporate the advantages of both prepreg and sheet molding compound, a molded article has been proposed in which prepreg and sheet molding compound are laminated and compression molded (Patent Document 1).

JP 2009-083441 A

However, in a molded product obtained by laminating and compressing prepreg and sheet molding compound, the prepreg in contact with the sheet molding compound tends to be distorted (twisted) due to the flow of the sheet molding compound during compression molding. Appearance is likely to be a problem.

In addition, during compression molding, volatile matter from the sheet molding tends to accumulate at the boundary between the sheet molding compound and the prepreg, which may cause voids and the like. The presence of voids and the like impairs the appearance of the molded article.

The present invention has been devised in view of the above points, and an object of the present invention is to provide a fiber-reinforced resin composite molded article having a good appearance free from disordered fibers and voids even in a complicated shape, and a method for producing the same. and

According to the first aspect of the invention, the surface layer portion is formed of a surface layer forming fiber reinforced resin material, and the base layer portion is made of a thermosetting resin and fibers shorter than the fibers contained in the surface layer forming fiber reinforced resin material. A base layer portion formed from a forming compound, and an intermediate layer portion formed from a thermosetting resin foam sheet having an open-cell structure disposed between the fiber-reinforced resin material for forming the surface layer portion and the compound for forming the base layer portion. wherein the fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having an open-cell structure, and the compound for forming the base layer portion are cured by heat compression and laminated together. It relates to a fiber reinforced resin composite molded body characterized by

According to a second aspect of the invention, there is provided, between the intermediate layer portion and the base layer portion, a reinforcing layer portion formed of a fiber-reinforced resin material for forming the reinforcing layer portion, and The fiber-reinforced resin material, the open-cell thermosetting resin foam sheet, the fiber-reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion are cured by heat compression and laminated together. characterized by being

The invention of claim 3 is the invention according to claim 2, wherein a second intermediate layer formed of a thermosetting resin foam sheet having a second open-cell structure is provided between the reinforcing layer and the base layer. The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having the open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the thermosetting of the second open-cell structure The flexible resin foam sheet and the compound for forming the base layer are cured by heating and compression and integrated by lamination.

The invention of claim 4 is characterized in that, in any one of claims 1 to 3, the fiber-reinforced resin material is a prepreg, and the base layer forming compound is a sheet molding compound.

In the invention of claim 5, the surface layer portion is formed of a fiber-reinforced resin material for forming the surface layer portion, and the base layer portion is composed of fibers shorter than the fibers contained in the fiber-reinforced resin material for forming the surface layer portion and a thermosetting resin. A base layer portion formed from a forming compound, and an intermediate layer portion formed from a thermosetting resin foam sheet having an open-cell structure disposed between the fiber-reinforced resin material for forming the surface layer portion and the compound for forming the base layer portion. In a method for producing a fiber-reinforced resin composite molded body having: The fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer are laminated with the thermosetting foam sheet having the open-cell structure sandwiched therebetween. The surface layer portion, the intermediate layer portion, and the base layer portion are laminated and integrated by heat-compressing and curing in the compressed state.

The invention of claim 6 is the fiber-reinforced resin material for forming the reinforcing layer portion in claim 5, wherein a fiber-reinforced resin material for forming the reinforcing layer portion is arranged between the thermosetting foam sheet having an open-cell structure and the compound for forming the base layer portion during the lamination. , the fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having an open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion are cured by heat compression. A reinforcing layer formed from the fiber-reinforced resin material for forming the reinforcing layer is provided between the intermediate layer and the base layer.

The invention according to claim 7 is the thermosetting resin foam having a second open-cell structure between the fiber-reinforced resin material for forming the reinforcing layer portion and the compound for forming the base layer portion in the lamination according to claim 6. Sheets are arranged, the fiber reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having the open cell structure, the fiber reinforced resin material for forming the reinforcing layer portion, and the second open cell structure A second intermediate formed from the thermosetting resin foam sheet having the second open-cell structure by laminating and integrating the thermosetting resin foam sheet and the base layer forming compound by heating and compressing them. A layer portion is provided between the reinforcing layer portion and the base layer portion.

The invention of claim 8 is characterized in that, in any one of claims 5 to 7, the fiber-reinforced resin material is a prepreg, and the base layer forming compound is a sheet molding compound.

According to the present invention, the fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer are laminated with a thermosetting resin foam sheet having an open-cell structure sandwiched therebetween, and then heated and compressed to flow the compound for forming the base layer. The influence of the flow of the base layer forming compound on the fiber reinforced resin material for forming the surface layer when the base layer forming compound flows into a shape is considered to be the continuity existing between the base layer forming compound and the fiber reinforced resin material for forming the surface layer. The foamed thermosetting resin sheet having a cell structure can alleviate the disturbance of the fibers in the fiber-reinforced resin material for forming the surface layer, thereby improving the appearance of the surface layer of the fiber-reinforced resin composite molded product.

In addition, the fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer are laminated with a thermosetting resin foam sheet having an open-cell structure sandwiched therebetween and then heated and compressed to flow the compound for forming the base layer. During shaping, volatiles generated from the base layer forming compound are absorbed by the thermosetting resin foam sheet with an open cell structure existing between the base layer forming compound and the surface layer forming fiber reinforced resin material. Since it is dispersed by being dispersed, or it is released to the outside through a thermosetting resin foam sheet with an open cell structure, the generation of voids can be prevented, and the appearance of the surface layer of the fiber reinforced resin composite molded product is good. can be made into something

Further, by providing a reinforcing layer portion formed from a fiber reinforced resin material for forming a reinforcing layer portion between the intermediate layer portion and the base layer portion, the strength of the fiber reinforced resin composite molded body with a good appearance of the surface layer portion and stiffness can be even higher.

Furthermore, by providing a second intermediate layer portion formed of a thermosetting resin foam sheet having a second open-cell structure between the reinforcing layer portion and the base layer portion, the base layer portion-forming compound is The effects of flow and volatile matter are determined by the open-cell thermosetting resin foam sheet forming the intermediate layer and the second open-cell thermosetting resin foam forming the second intermediate layer. It can be relieved by the thermosetting resin foam sheet of two open cell structures with the body sheet, the appearance of the surface layer part of the fiber reinforced resin composite molding can be further improved, and the strength and rigidity are high. can be done.

1 is a cross-sectional view showing a fiber-reinforced resin composite molded article according to a first embodiment of the present invention; FIG. 1 is a cross-sectional view of one embodiment of a mold used in the manufacturing method of the first embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view showing one embodiment of lamination in the manufacturing method of the first embodiment of the present invention. FIG. 4 is a cross-sectional view showing one embodiment at the time of heat compression in the manufacturing method of the first embodiment of the present invention; FIG. 4 is a cross-sectional view showing a fiber-reinforced resin composite molded article according to a second embodiment of the present invention; FIG. 10 is a cross-sectional view showing one embodiment at the time of lamination in the manufacturing method of the second embodiment of the present invention; Fig. 10 is a cross-sectional view showing a fiber-reinforced resin composite molded article according to a third embodiment of the present invention; It is a sectional view showing one embodiment at the time of lamination in a manufacturing method of a 3rd embodiment of the present invention. 1 is a cross-sectional view of a molding die used in an example of the present invention; FIG. FIG. 2 is a table showing determination of contents of thermosetting resin foam sheets and physical properties and appearance of fiber-reinforced resin composite moldings in Examples and Comparative Examples. FIG.

The fiber-reinforced resin composite molded article and the method for producing the same according to the present invention will be described below.
A fiber-reinforced resin composite molded body 10 of the first embodiment shown in FIG. An intermediate layer portion 31 is disposed between the portion 11 and the base layer portion 21 and is formed of a thermosetting resin foam sheet having an open cell structure. The fiber-reinforced resin composite molded body 10 has a good appearance without problems caused by disorder of the fibers in the surface layer 11 or voids from the compound for forming the base layer. It should be noted that which of the surface layer portion 11 and the base layer portion 21 is to be the front side surface or the back side surface of the fiber reinforced resin composite molded body 10 is determined according to the application of the fiber reinforced resin composite molded body 10. .

The surface layer portion 11 is formed by heating and compressing a fiber-reinforced resin material for forming the surface layer portion and hardening it.
The fiber-reinforced resin material for forming the surface layer is a fiber sheet impregnated with a thermosetting resin. Examples of the fiber sheet include those made of fibers such as carbon fiber, glass fiber, and aramid fiber. In particular, carbon fiber is preferable from the viewpoint of weight reduction and rigidity improvement. The fibrous sheet may be woven, knitted, nonwoven, or the like. Woven fabrics include plain weave, twill weave, satin weave, and triaxial weave. Also, the fiber sheet may be composed of fibers oriented in one direction or in multiple directions. The fiber sheet is preferably a fiber fabric from the viewpoint of improving rigidity.

The fibers constituting the fiber sheet preferably have a longer fiber length than the fibers contained in the base layer forming compound described later, and examples thereof include continuous fibers and discontinuous fibers.

Examples of the thermosetting resin with which the fiber sheet is impregnated include epoxy resin, phenol resin, vinyl ester resin, and mixed resins thereof. A prepreg is preferable as the fiber-reinforced resin material for forming the surface layer, which is a fiber sheet impregnated with a thermosetting resin.

The base layer portion 21 is formed by heating and compressing a base layer portion forming compound composed of a thermosetting resin and fibers shorter than the fibers contained in the fiber reinforced resin material for forming the surface layer portion and hardening it. The base layer portion 21 shown in the figure has reinforcing ribs 23 and bosses 25 formed as projecting portions on the surface. In addition, the surface shape of the base layer portion 21 is not limited to the convex portion formed by the reinforcing ribs 23 and the bosses 25, and may be an appropriate concave shape, convex shape, uneven shape, uneven shape, etc. depending on the application of the fiber-reinforced resin composite molded body 10. Alternatively, it may be one without irregularities.

The length of the fibers contained in the base layer forming compound is preferably 30 mm or less from the standpoint of moldability, and preferably 5 mm or longer from the standpoint of rigidity improvement. Short fibers such as carbon fibers and glass fibers are examples of the fibers contained in the base layer forming compound. Carbon fiber is particularly preferable from the viewpoint of weight reduction and rigidity improvement.

Examples of the thermosetting resin contained in the base layer forming compound include epoxy resin, phenol resin, vinyl ester resin, unsaturated polyester resin, and mixed resins thereof.
As the compound for forming the base layer, a sheet molding compound (hereinafter referred to as SMC) is preferable. SMC refers to a sheet-shaped molding material in which a fiber material such as glass fiber or carbon fiber is impregnated with a compound containing a filler, a curing agent, and the like in a thermosetting resin.

In the intermediate layer portion 31, a thermosetting resin foam sheet having an open-cell structure is disposed between the fiber-reinforced resin material for forming the surface layer portion and the compound for forming the base layer portion. It is heat-compressed together with the part-forming compound, contacted with or impregnated with the thermosetting resin impregnated in the fiber-reinforced resin material for forming the surface layer part and the compound for forming the base layer part, and the thermosetting resin is cured. . The shape of the intermediate layer portion 31 is fixed in a state in which the open-cell thermosetting resin foam sheet is compressed by curing the thermosetting resin.

Examples of the open-cell thermosetting resin foam sheet include sheets of urethane resin foam, melamine resin foam, and the like. By making the thermosetting resin foam have an open cell structure, the thermosetting resin can be impregnated into the thermosetting resin foam sheet, and the thermosetting resin foam sheet can be easily compressed. Furthermore, volatile substances from the SMC can be released during the production of the fiber-reinforced resin composite molded body 10, and the generation of voids can be prevented. When the open-cell thermosetting resin foam sheet is made of urethane resin foam, the number of cells (JIS K 6400-1) is preferably 5 to 90/25 mm. If the value of the number of cells is too small, the diameter of the cells will increase and the strength will decrease. On the other hand, if the number of cells is too large, the diameter of the cells will be small, resulting in poor air permeability.

In addition, by configuring the intermediate layer portion 31 with a thermosetting resin foam sheet having an open-cell structure, the thermosetting resin foam having an open-cell structure can be generated during heat compression when manufacturing the fiber-reinforced resin composite molded body 10. A thermosetting resin foam sheet with an open-cell structure prevents the body sheet from softening or fusing, and prevents the flow of the base layer forming compound during heat compression from adversely affecting the surface layer forming fiber reinforced resin material. can be prevented.

The surface layer portion 11, the base layer portion 21, and the intermediate layer portion 31 are formed into a fiber reinforced resin material for forming the surface layer portion with a thermosetting resin foam sheet having an open cell structure sandwiched therebetween when the fiber reinforced resin composite molded body 10 is manufactured. The fiber-reinforced resin material for forming the surface layer and the thermosetting resin of the compound for forming the base layer are cured by heating and compression performed by laminating the compound for forming the base layer, thereby integrating them.

In the method for producing the fiber-reinforced resin composite molded body 10, a fiber-reinforced resin material for forming the surface layer and a compound for forming the base layer are laminated with a thermosetting resin foam sheet having an open-cell structure sandwiched therebetween, and then heated and compressed to form a surface layer. The thermosetting resin contained in the portion-forming fiber-reinforced resin material and the base layer-forming compound is cured in the compressed state.

One embodiment of heat compression will be described using the molding die 50 shown in FIG. The molding die 50 is composed of an upper die 51 and a lower die 53 . In this embodiment, the mold surface of the upper mold 51 is flat. The mold surface of the lower mold 53 has a shape corresponding to the surface of the base layer portion 21 of the fiber-reinforced resin composite molded body 10. molding recesses 55 and 57 are provided.

The molding die 50 is heated to a predetermined temperature by placing it in a heating furnace in advance or by heating means (for example, an electric heater, etc.) provided in the molding die 50 . The heating temperature is set to a temperature at which the thermosetting resin contained in the fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer are cured.

With the molding die 50 opened, as shown in FIG. The fiber reinforced resin material 11A for the first layer is arranged and laminated in this order. It is preferable to apply a release agent to the mold surfaces of the upper mold 51 and the lower mold 53 in advance.

The base layer forming compound 21A is composed of short fibers such as carbon fibers and glass fibers as described above, and thermosetting resins such as epoxy resins, phenol resins, vinyl ester resins, unsaturated polyester resins, or mixed resins thereof. Impregnated, preferably SMC. The short fibers contained in the base layer forming compound 21A are shorter than the fibers contained in the surface layer forming fiber reinforced resin material 11A, and preferably 30 mm or less from the standpoint of moldability, and from the standpoint of improving rigidity. is preferably 5 mm or more.

The base layer portion forming compound 21A is placed on the mold surface of the lower mold 53 so as to cover the molding recesses 55 and 57 . The size of the base layer portion forming compound 21 A is such that it can cover the molding recesses 55 and 57 , and may be equal to the size of the mold surface of the lower mold 53 .

The thermosetting resin foam sheet 31A having an open cell structure is made of a thermosetting resin foam having an open cell structure such as a urethane resin foam or a melamine resin foam as described above. It may be impregnated with a thermosetting resin such as a vinyl ester resin or a mixed resin thereof. When the open-cell thermosetting resin foam sheet is made of urethane resin foam, the number of cells (JIS K 6400-1 is 5 to 90 cells/25 mm, the apparent density (JIS K 7222) is 20 to 100 kg/m ³ is preferable, more preferably 30 to 75 kg/m ^3. Furthermore, in order to ensure air permeability, it is preferable to perform a known cell membrane removal treatment.In addition, a thermosetting resin foam sheet with an open cell structure. If the thickness is too thin, appearance problems will occur due to disorder of the fibers and voids in the surface layer 11, and if it is too thick, the strength of the fiber-reinforced resin composite molded body 10 will decrease. A thickness of .3 to 3.0 mm is preferred.

If the open-cell thermosetting resin foam sheet is adhered or impregnated with the thermosetting resin in advance, it is limited to dipping or coating in which the open-cell thermosetting resin foam sheet is immersed in the thermosetting resin. can't For example, by attaching (including laminating) a thermosetting resin foam sheet having an open cell structure to the surface layer forming fiber reinforced resin material 11A and the base layer forming compound 21A, the surface layer forming fiber reinforced resin material 11A can be formed. The thermosetting resin adhering to the surface of the compound 21A for forming the base layer portion may adhere to or impregnate the thermosetting resin foam sheet having an open cell structure.

Further, when the surface layer forming fiber reinforced resin material 11A, the thermosetting resin foam sheet 31A having an open cell structure, and the base layer forming compound 21A are heat-compressed, the surface layer forming fiber reinforced resin material 11A and the base layer The thermosetting resin exuded from the forming compound 21A may be impregnated into the open-cell thermosetting resin foam sheet 31A.

The open-cell thermosetting resin foam sheet 31A is placed in the lower mold 53 so as to cover the base layer forming compound 21A. The size of the thermosetting resin foam sheet 31A having an open-cell structure is set so that the influence of the flow of the base layer forming compound 21A is not transmitted to the surface layer forming fiber reinforced resin material 11A. It is preferably sized to cover a range equal to or greater than the flow range of 21A.

As described above, the fiber-reinforced resin material 11A for forming the surface layer is obtained by impregnating a fiber sheet such as a carbon fiber fabric with a thermosetting resin such as an epoxy resin, a phenol resin, a vinyl ester resin, or a mixed resin thereof. and prepreg is preferred. The fibers of the fiber sheet preferably have a longer fiber length than the fibers contained in the base layer forming compound. In addition, the fiber-reinforced resin material 11A for forming the surface layer portion is not limited to the case of being composed of one sheet of prepreg, and may be composed of a laminate of a plurality of sheets of prepreg.

After laminating the base layer forming compound 21A, the impregnated foam sheet 31A, and the surface layer forming fiber reinforced resin material 11A in this order on the mold surface of the lower mold 53, the upper mold 51 is moved to the lower mold as shown in FIG. 53, and the base layer forming compound 21A, the impregnated foam sheet 31A, and the surface layer forming fiber reinforced resin material 11A are heat-compressed in a laminated state.

In addition, when the molding recesses and protrusions are provided on the mold surface of the upper mold instead of the mold surface of the lower mold, the mold surface of the lower mold includes the fiber reinforced resin material 11A for forming the surface layer and the open cell structure. The thermosetting resin foam sheet 31A and the base layer forming compound 21A are laminated in this order.
Further, when the molding recesses and projections are not provided on either the mold surface of the lower mold or the mold surface of the upper mold, the surface layer forming fiber reinforced resin material 11A and the open cell structure for the mold surface of the lower mold are formed. The lamination arrangement of the thermosetting resin foam sheet 31A and the base layer forming compound 21A may be in this order or reverse.

The behavior of the base layer portion forming compound 21A, the thermosetting resin foam sheet 31A having an open cell structure, and the surface layer portion forming fiber reinforced resin material 11A during heat compression will be described below.
The base layer portion forming compound 21A becomes fluid by heating, enters the molding recesses 55 and 57 of the mold surface of the lower mold 53, and is cast on the mold surface of the lower mold 53. As shown in FIG.

The open-cell thermosetting resin foam sheet 31A is compressed between the base layer forming compound 21A and the surface layer forming fiber reinforced resin material 11A, and the base layer forming compound 21A and the surface layer forming fiber reinforced resin material 11A are compressed. The thermosetting resin of the resin material 11A contacts or impregnates. In addition, the thermosetting resin foam sheet 31A having an open-cell structure exerts a buffering action between the base layer forming compound 21A and the surface layer forming fiber reinforced resin material 11A, and prevents the base layer forming compound 21A from flowing. In addition to preventing the influence of the surface layer portion forming fiber reinforced resin material 11A from being transmitted, the volatile matter from the base layer portion forming compound 21A is absorbed to prevent the generation of voids.

The thermosetting resin impregnated in the surface layer forming fiber reinforced resin material 11A exudes due to compression. The thermosetting resin exuded from the fiber-reinforced resin material 11A for forming the surface layer contacts or impregnates the thermosetting resin foam sheet 31A having an open cell structure.

The base layer forming compound 21A, the thermosetting resin foam sheet 31A having an open cell structure, and the surface layer forming fiber reinforced resin material 11A are each cured while being compressed. Thereby, the base layer portion 21 is formed from the base layer portion forming compound 21A, the intermediate layer portion 31 is formed from the thermosetting resin foam sheet 31A having an open cell structure, and the fiber reinforced resin material 11A for forming the surface layer portion is formed. A surface layer portion 11 is formed. At the same time, the respective thermosetting resins come into contact with each other or mix and harden, so that the base layer portion 21, the intermediate layer portion 31, and the surface layer portion 11 are bonded and integrated, and the fiber-reinforced resin composite molded body 10 is formed. be. In the fiber-reinforced resin composite molded body 10, the influence of the flow of the base layer forming compound 21A is buffered by the thermosetting resin foam sheet 31A having an open cell structure, and the volatile matter from the base layer forming compound 21A is released from the open cells. Since it is absorbed by the structured thermosetting resin foam sheet 31A, even if it has a complicated shape, the surface layer portion 11 with a good appearance without disordered fibers or voids can be obtained.

The fiber-reinforced resin composite molded body 101 of the second embodiment shown in FIG. 121 between the intermediate layer portion 311 and the base layer portion 211, which is different from the fiber-reinforced resin composite molded body 10 of the first embodiment.

The surface layer portion 111 is made of a fiber-reinforced resin material for forming a surface layer portion, and has the same configuration as the surface layer portion 11 of the first embodiment.

The intermediate layer portion 311 is formed from a thermosetting resin foam sheet having an open cell structure, and has the same configuration as the intermediate layer portion 31 of the first embodiment.

The reinforcing layer portion 121 is formed from a fiber-reinforced resin material for forming a reinforcing layer portion. The reinforcing layer-forming fiber-reinforced resin material is made of a fiber sheet impregnated with a thermosetting resin in the same manner as the surface layer-forming fiber-reinforced resin material, and is preferably a prepreg.

The base layer portion 211 is formed from a base layer portion forming compound, and has the same configuration as the base layer portion 21 of the first embodiment. The fibers contained in the base layer forming compound are shorter than the fibers contained in the surface layer forming fiber reinforced resin material and the reinforcing layer forming fiber reinforced resin material. On the surface of the base layer portion 211, reinforcing ribs 231 and bosses 251 are formed as projecting portions.

The surface layer portion 111 , the intermediate layer portion 311 , the reinforcing layer portion 121 , and the base layer portion 211 are made of a fiber reinforced resin material for forming the surface layer portion and a thermosetting resin foam having an open cell structure when manufacturing the fiber reinforced resin composite molded body 101 . The fiber reinforced resin material for forming the surface layer portion, the fiber reinforced resin material for forming the reinforcing layer portion, and the base layer portion are formed by heat compression performed by laminating the body sheet, the fiber reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion. The thermosetting resin of the compound exudes and adheres to and impregnates the thermosetting resin foam sheet with an open cell structure. .

A method for manufacturing the fiber-reinforced resin composite molding 101 of the second embodiment will be described below.
As shown in FIG. 6, a base layer portion forming compound 211A, a reinforcing layer portion forming fiber reinforced resin material 121A, and a thermosetting resin foam sheet 311A having an open cell structure are placed on the mold surface of the lower mold 53 of the molding die 50 . , and the fiber-reinforced resin material 111A for forming the surface layer portion are arranged and laminated in this order. The molding die 50 is as described in the manufacturing method of the first embodiment.

Next, the upper mold 51 is placed on the lower mold 53, and a base layer forming compound 211A, a reinforcing layer forming fiber reinforced resin material 121A, an open cell structure thermosetting resin foam sheet 311A, and a surface layer forming fiber reinforced The resin material 111A is heat-compressed in a laminated state. Due to the heat compression, the base layer forming compound 211A flows to form the mold surface shape of the lower mold 53, and the base layer forming compound 211A, the reinforcing layer forming fiber reinforced resin material 121A, and the surface layer forming fiber reinforced. The thermosetting resin exudes from the resin material 111A and adheres to and impregnates the open-cell thermosetting resin foam sheet 311A. As a result, the fiber-reinforced resin composite molded body 101 in which the surface layer portion 111, the intermediate layer portion 311, the reinforcing layer portion 121, and the base layer portion 211 are laminated and integrated as shown in FIG. 5 is obtained.

When the fiber-reinforced resin composite molded body 101 of the second embodiment is shaped by flowing the base layer forming compound by heat compression, the influence of the flow of the base layer forming compound and the influence from the base layer forming compound The influence of volatile matter can be mitigated by the thermosetting resin foam sheet having an open cell structure, and the appearance of the surface layer portion 111 is improved. Furthermore, the presence of the reinforcing layer portion 121 increases the strength and rigidity of the fiber-reinforced resin composite molded body 101 .

The fiber-reinforced resin composite molded body 102 of the third embodiment shown in FIG. 7 includes a surface layer portion 112, an intermediate layer portion 312, a reinforcing layer portion 122, a second intermediate layer portion 322, and a base layer portion 212. It is an integrated one. It differs from the fiber-reinforced resin composite molding 10 of the first embodiment in that it has a reinforcing layer portion 122 and a second intermediate layer portion 322 between the intermediate layer portion 312 and the base layer portion 212 . Further, it differs from the fiber-reinforced resin composite molding 101 of the second embodiment in that it has a second intermediate layer portion 322 between the reinforcing layer portion 122 and the base layer portion 212 .

The surface layer portion 112 is made of a fiber-reinforced resin material for forming a surface layer portion, and has the same configuration as the surface layer portion 11 of the first embodiment and the surface layer portion 111 of the second embodiment.

The intermediate layer portion 312 is formed from a thermosetting resin foam sheet having an open cell structure, and has the same configuration as the intermediate layer portion 31 of the first embodiment and the intermediate layer portion 311 of the second embodiment. .

The reinforcing layer portion 122 is formed from a fiber-reinforced resin material for forming the reinforcing layer portion, and has the same configuration as the reinforcing layer portion 121 of the first embodiment.

The second intermediate layer portion 322 is formed from a thermosetting resin foam sheet having a second open-cell structure. The second open-cell thermosetting resin foam sheet is made of the same material as the open-cell thermosetting resin foam sheet forming the intermediate layer portion 312 .

The base layer portion 212 is formed from a base layer portion forming compound, and has the same configuration as the base layer portion 21 of the first embodiment and the base layer portion 211 of the second embodiment. On the surface of the base layer portion 212, reinforcing ribs 232 and bosses 252 are formed as projecting portions.

The surface layer portion 112 , the intermediate layer portion 312 , the reinforcing layer portion 122 , the second intermediate layer portion 322 , and the base layer portion 212 are formed from a fiber reinforced resin material for forming the surface layer portion, a continuous A thermosetting resin foam sheet with a cell structure, a fiber reinforced resin material for forming a reinforcing layer, a second thermosetting resin foam sheet with an open cell structure, and a compound for forming a base layer are laminated and heated and compressed. , the thermosetting resin of the fiber-reinforced resin material for forming the surface layer portion, the fiber-reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion exudes to form a thermosetting resin foam sheet having an open-cell structure and a second The thermosetting resin that adheres to, impregnates, or oozes out from the thermosetting resin foam sheet having an open-cell structure contacts or mixes with each other and hardens to be integrated.

A method for manufacturing the fiber-reinforced resin composite molding 102 of the third embodiment will be described below.
As shown in FIG. 8, on the mold surface of the lower mold 53 of the molding die 50, a base layer forming compound 212A, a second open-cell thermosetting resin foam sheet 322A, a reinforcing layer forming fiber reinforced The resin material 122A, the open-cell thermosetting resin foam sheet 312A, and the fiber-reinforced resin material 112A for forming the surface layer are arranged and laminated in this order. The molding die 50 is as described in the manufacturing method of the first embodiment.

Next, the upper mold 51 is placed on the lower mold 53, and the base layer forming compound 212A, the second open-cell thermosetting resin foam sheet 322A, the reinforcing layer forming fiber reinforced resin material 122A, and the open-cell structure are prepared. The thermosetting resin foam sheet 312A and the surface layer forming fiber reinforced resin material 112A are heat-compressed in a laminated state. Due to the heating and compression, the base layer forming compound 212A flows to form the mold surface shape of the lower mold 53, and the base layer forming compound 212A, the reinforcing layer forming fiber reinforced resin material 122A, and the surface layer forming fiber reinforced. The thermosetting resin oozes from the resin material 112A and adheres to and impregnates the open-cell thermosetting resin foam sheet 312A and the second open-cell foam sheet 322A. mix and harden. As a result, the fiber-reinforced resin composite molded body 102 in which the surface layer portion 112, the intermediate layer portion 312, the reinforcing layer portion 122, the second intermediate layer portion 322, and the base layer portion 212 are laminated and integrated as shown in FIG. 7 is obtained.

When the fiber-reinforced resin composite molded body 102 of the third embodiment is shaped by flowing the base layer forming compound by heat compression, the influence of the flow of the base layer forming compound and the influence from the base layer forming compound The influence of volatile substances can be mitigated by the open-cell thermosetting resin foam sheet and the second open-cell thermosetting resin foam sheet, and the appearance of the surface layer 112 is improved. . Furthermore, the presence of the reinforcing layer portion 122 increases the strength and rigidity of the fiber-reinforced resin composite molded body 102 .

In order to confirm the effects of the present invention, a molding die 60 shown in FIG. 9 was used to produce fiber-reinforced resin composite molded articles of each of Examples and Comparative Examples shown below.
Both the upper mold 61 and the lower mold 63 of the molding die 60 have flat mold surfaces. The plane size of the mold surface is 200×300 mm, and the dimension between the mold surface of the upper mold 61 and the mold surface of the lower mold 63 (equivalent to the thickness of the molded product) when the mold is closed is set to 1.5 mm. .

・Example 1
First, in a phenol resin solution (manufactured by Sumitomo Bakelite Co., Ltd., product name: PR-55791B, resin concentration 60 wt% ethanol solution), twill carbon fiber fabric (manufactured by Teijin Limited, product name: W-3101, fiber weight 200 g / m ² ) was cut to 200×300 mm, soaked, taken out, and air-dried at room temperature of 25° C. for 2 hours to prepare a phenolic resin-impregnated carbon fiber fabric.

On the surface of the carbon fiber fabric impregnated with phenolic resin, a thermosetting resin foam sheet with an open cell structure (urethane resin foam with cell membrane removal treatment, manufactured by INOAC Corporation, product name: MF-50, apparent density (JIS K 7222) 30 kg/m ³ , the number of cells (JIS K 6400-1) 50 cells/25 mm, porosity 97.1%, thickness 0.4 mm) was cut into 200×300 mm and pasted together. The formula for calculating the porosity is as follows. Porosity = (true specific gravity of urethane resin - bulk specific gravity (≒ apparent density of urethane resin foam)) / true specific gravity of urethane resin x 100
The true specific gravity of urethane resin is 1.05.

After that, the carbon fiber fabric impregnated with phenol resin and the thermosetting resin foam sheet with an open cell structure on the surface thereof are dried in an atmosphere of 60 ° C. for 1 hour, and the carbon fiber fabric impregnated with phenol resin is used for forming the surface layer. A fiber-reinforced resin material (prepreg) was formed, and a thermosetting resin foam sheet having an open-cell structure was attached to the surface of the fiber-reinforced resin material (prepreg).

The molding die 60 is heated to 140° C., the molding die 60 is opened, and a mold release agent is applied to the mold surface. A compound (SMC, manufactured by Mitsubishi Chemical Corporation, product name: STR120N131, thickness 2 mm, fiber content 53%), a thermosetting resin foam sheet with an open cell structure, and a fiber reinforced resin material (prepreg) for forming the surface layer , arranged in that order. Then, the mold 60 is closed with the upper mold 61 overlaid, and a pressure of 5 MPa is applied at 140° C. for 15 minutes to form a base layer forming compound, a thermosetting resin foam sheet with an open cell structure, and a surface layer forming fiber. The reinforced resin material was heated and compressed to cure the thermosetting resin of the compound for forming the base layer, the thermosetting resin foam sheet having an open cell structure, and the fiber reinforced resin material for forming the surface layer.

After that, after cooling the molding die 60 at room temperature, the upper mold 61 and the lower mold 63 are opened, and the surface layer formed of the fiber reinforced resin material for forming the surface layer and the thermosetting resin foam sheet with an open cell structure are formed. A fiber-reinforced resin composite molded article of Example 1 was obtained, which was an integral product of the intermediate layer portion formed from the above and the base layer portion formed from the compound for forming the base layer portion.

・Example 2
A fiber-reinforced resin composite molded article of Example 2 was produced in the same manner as in Example 1, except that the thickness of the open-cell thermosetting resin foam sheet in Example 1 was changed to 0.6 mm.

・Example 3
A fiber-reinforced resin composite molded article of Example 3 was produced in the same manner as in Example 1, except that the thickness of the open-cell thermosetting resin foam sheet in Example 1 was changed to 1.0 mm.

・Example 4
A fiber-reinforced resin composite molded article of Example 4 was produced in the same manner as in Example 1, except that the thickness of the open-cell thermosetting resin foam sheet in Example 1 was changed to 2.0 mm.

・Example 5
A fiber-reinforced resin composite molded article of Example 5 was produced in the same manner as in Example 1, except that the thickness of the open-cell thermosetting resin foam sheet in Example 1 was changed to 3.0 mm.

・Example 6
The thermosetting resin foam sheet with an open cell structure in Example 1 has a cell number (JIS K 6400-1) of 80/25 mm, a porosity of 95.2%, an apparent density (JIS K 7222) of 75 kg/m ³ , A fiber-reinforced resin composite molded body of Example 6 was produced in the same manner as in Example 1, except that the cell membrane-removed urethane resin foam (manufactured by INOAC Corporation, product name: MF-80A) having a thickness of 1.0 mm was used. made.

・Example 7
The open-cell thermosetting resin foam sheet of Example 1 had a cell number (JIS K 6400-1) of 10/25 mm, a porosity of 97.3%, an apparent density (JIS K 7222) of 30 kg/m ³ , A fiber-reinforced resin composite molded body of Example 7 was produced in the same manner as in Example 1, except that the cell membrane-removed urethane resin foam (manufactured by INOAC Corporation, product name: MF-10) having a thickness of 1.0 mm was used. made.

・Example 8
The open-cell thermosetting resin foam sheet of Example 1 had a cell number (JIS K 6400-1) of 8/25 mm, a porosity of 97.4%, an apparent density (JIS K 7222) of 30 kg/m ³ , A fiber-reinforced resin composite molded article of Example 8 was produced in the same manner as in Example 1, except that the cell membrane-removed urethane resin foam (manufactured by INOAC Corporation, product name: MF-8) having a thickness of 1.0 mm was used. made.

・Example 9
The thermosetting resin foam sheet with an open cell structure in Example 1 had a cell number (JIS K 6400-1) of 50/25 mm, a porosity of 97.0%, an apparent density (JIS K 7222) of 30 kg/m ³ , A fiber-reinforced resin composite molding of Example 9 was prepared in the same manner as in Example 1, except that the thickness was 1.0 mm and the urethane resin foam without cell membrane removal treatment (manufactured by INOAC Corporation, product name: MF-50) was used. was made.

Comparative Example A fiber-reinforced resin composite molded article (without an intermediate layer portion) of Comparative Example was produced in the same manner as in Example 1 except that the thermosetting resin foam sheet of open cell structure in Example 1 was omitted.

The overall thickness (mm) and flexural modulus (GPa) of the fiber-reinforced resin composite moldings of Examples and Comparative Examples were measured, and the appearance was judged.
Flexural modulus (GPa) was measured based on JIS K 7074.
For the appearance, the surface of the surface layer of the fiber-reinforced resin composite molded article was visually observed, and voids were judged. Fiber twist (twist) was measured and determined using a ruler as follows.
Regarding fiber twist, when the arrangement of fibers is disordered over a range of 2 mm or more on the surface of the surface layer, it is indicated as "x" because there is twist of 2 mm or more, and when the twist is less than 2 mm, it is rated as "○". .
Voids were evaluated as "presence" when holes (pinholes) were observed in the thermosetting resin on the surface of the surface layer, and were evaluated as "absence" when no holes were observed.

FIG. 10 shows the configuration of the thermosetting resin foam sheet in each example and comparative example, and the measurement results and appearance evaluation results of the fiber-reinforced resin composite moldings.
The fiber-reinforced resin composite molded bodies of Examples 1 to 9 have an overall thickness of 1.4 to 1.7 mm, a flexural modulus of 32 to 38 GPa, an appearance judgment of fiber twist "◯", voids "no", and strength was sufficient and the appearance of the surface layer portion was good.
On the other hand, the comparative example in which the surface layer portion and the base layer portion are in contact with each other without the intermediate layer portion has a total thickness of 1.4 mm, a bending elastic modulus of 38 GPa, an appearance judgment of fiber twist “×”, voids, and strength. It was sufficient, but the appearance of the surface layer was poor.

As described above, according to the present invention, a fiber-reinforced resin composite molded article having a base layer formed from a base layer forming compound with good fluidity is formed into a surface layer having a good appearance without fiber disorder, voids, or the like. can be made to have Therefore, the present invention is suitable for fiber-reinforced resin composite moldings that require complicated surface shapes.

10, 101, 102 fiber-reinforced resin composite molded article 11, 111, 112 surface layer portion 11A, 111A, 112A fiber-reinforced resin material for forming surface layer portion 21, 211, 212 base layer portion 21A, 211A, 212A compound for forming base layer portion 31, 311, 312 intermediate layer portion 31A, 311A, 312A open-cell thermosetting resin foam sheet 322 second intermediate layer portion 322A second open-cell thermosetting resin foam sheet 50 molding die 51 top Mold 53 Lower mold 55, 57 Molding recess 60 Mold for example 61 Upper mold for example 63 Lower mold for example

Claims (8)

a surface layer formed of a fiber-reinforced resin material for forming a surface layer;
a base layer portion formed from a base layer portion forming compound including fibers shorter than the fibers contained in the surface layer portion forming fiber-reinforced resin material and a thermosetting resin;
An intermediate layer portion formed from a thermosetting resin foam sheet having an open-cell structure disposed between the fiber-reinforced resin material for forming the surface layer portion and the compound for forming the base layer portion,
The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having an open-cell structure, and the compound for forming the base layer portion are cured by heating and compression, and laminated and integrated. Reinforced resin composite molding. Between the base layer portion and the intermediate layer portion, a reinforcing layer portion formed of a fiber reinforced resin material for forming a reinforcing layer portion is provided,
The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having an open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion are cured by heat compression. 2. The fiber-reinforced resin composite molded article according to claim 1, wherein the fiber-reinforced resin composite molded article is laminated and integrated. A second intermediate layer portion formed of a thermosetting resin foam sheet having a second open-cell structure is provided between the reinforcing layer portion and the base layer portion,
The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having the open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the second thermosetting resin foam having the open-cell structure. 3. The fiber-reinforced resin composite molded article according to claim 2, wherein the body sheet and the base layer portion-forming compound are laminated and integrated by being cured by heat compression. The fiber-reinforced resin material for forming the surface layer portion is a prepreg,
The fiber-reinforced resin composite molded article according to any one of claims 1 to 3, wherein the base layer forming compound is a sheet molding compound. A surface layer formed from a fiber-reinforced resin material for forming a surface layer, and a compound for forming a base layer made of a thermosetting resin and fibers shorter than the fibers contained in the fiber-reinforced resin material for forming a surface layer. A fiber-reinforced resin composite having a base layer and an intermediate layer formed of a thermosetting resin foam sheet having an open-cell structure disposed between the fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer. A method for manufacturing a molded body,
The fiber-reinforced resin material for forming the surface layer and the compound for forming the base layer are laminated with the thermosetting foam sheet having the open-cell structure sandwiched therebetween, are heat-compressed, and are cured in the compressed state to obtain the surface layer. A method for producing a fiber-reinforced resin composite molded article, wherein the part, the intermediate layer part, and the base layer part are laminated and integrated. During the lamination, a fiber reinforced resin material for forming a reinforcing layer portion is arranged between the thermosetting foam sheet having an open cell structure and the compound for forming the base layer portion,
The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having an open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the compound for forming the base layer portion are cured by heat compression. 6. The fiber-reinforced resin composite molding according to claim 5, wherein the reinforcing layer portion formed from the fiber-reinforced resin material for forming the reinforcing layer portion is provided between the intermediate layer portion and the base layer portion. body manufacturing method. During the lamination, a thermosetting resin foam sheet having a second open-cell structure is arranged between the fiber-reinforced resin material for forming the reinforcing layer portion and the compound for forming the base layer portion,
The fiber-reinforced resin material for forming the surface layer portion, the thermosetting resin foam sheet having the open-cell structure, the fiber-reinforced resin material for forming the reinforcing layer portion, and the second thermosetting resin foam having the open-cell structure. The body sheet and the base layer portion-forming compound are cured by heating and compression to be laminated and integrated, and the second intermediate layer portion formed from the thermosetting resin foam sheet having the second open-cell structure is 7. The method for producing a fiber-reinforced resin composite molding according to claim 6, wherein the reinforcing layer is provided between the base layer. The fiber-reinforced resin material for forming the surface layer portion is a prepreg,
The method for producing a fiber-reinforced resin composite molded article according to any one of claims 5 to 7, wherein the compound for forming the base layer portion is a sheet molding compound.

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