JP5673375B2 - Fiber resin composite structure, method for producing molded body, and molded body - Google Patents

Description

  The present invention relates to a fiber composite structure, a method for producing a molded body, and a molded body.

  Fiber reinforced composite materials consisting of plastic fibers, carbon fibers, glass fibers and other reinforcing fibers and resin matrices are excellent in strength and rigidity, so they are widely used in electrical / electronic applications, civil engineering / architecture applications, automotive applications, aircraft applications, etc. It is used. Among them, a composite material using a base material in which reinforcing fibers are uniformly dispersed has isotropic mechanical properties, and furthermore, if it is a material that develops high strength, the applicable applications are greatly increased.

  As a method for producing a fiber-reinforced composite material by uniformly and isotropically dispersing reinforcing fibers, a wet papermaking method has been studied. For example, in Patent Document 1, a web-like molding material prepared by dispersing and making glass fiber and aramid fiber in water as a reinforcing resin and making paper is heated and pressure-molded (compression-molded) in a molding die to strengthen the fiber. Of phenolic resin molded products. Patent Document 2 discloses that glass fibers and vinylon fibers are dispersed in water together with phenol resin fine particles, and these are made and dried to obtain a sheet-like molding material, which is then heated and pressed in a mold. The production of plate-shaped molded products is described, and improvement of molded product characteristics centering on mechanical properties is being studied by selecting reinforcing fibers to be made and resin to be dispersed and mixed.

  The wet papermaking method is a fiber composite material in which matrix resin particles and reinforcing fibers are dispersed in water and dispersed uniformly by rolling, and the reinforcing fibers are entangled with each other to give high strength properties to the molded body after heat and pressure molding Has been granted. However, since the fibers are intertwined strongly, the fluidity is poor, and in the three-dimensional drawing, the surface of the molded body is wrinkled or ground cracks occur, so that it has a plate-shaped molded body or an extremely shallow convex shape. It was only used for molded bodies. In addition, the fiber composite material after papermaking is difficult to handle because the resin particles easily fall off during handling.

  As a method of manufacturing a three-dimensional molded container, a net mold having a depression that matches the outer shape of the target molded article is prepared, and after the papermaking raw material is wet-made by the net mold, it is dried and three-dimensional. Methods for manufacturing molded containers are generally known. However, the wet molding method takes time and labor to manufacture a molded container and has a problem that the productivity is extremely low, and drawing processing of a paper sheet produced by the wet papermaking method has been studied.

  Regarding drawing processing of a composite sheet produced by a wet papermaking method, Patent Document 3 describes a press-formed paper containing thermoplastic fibers having natural fiber and thermal adhesiveness and appropriate fiber elongation. Reference 4 describes a paperboard for thermoforming with a laminated structure of a paper layer mainly composed of thermoplastic fibers and a paper layer mainly composed of cellulose pulp. Although good, the mechanical strength of the molded product is not high, and applicable applications include packaging containers for electrical and electronic parts, packaging containers for other industrial parts, packaging containers for various foods, trays, and disposables. It was limited to tableware (lunch boxes, folding boxes, etc.), vehicle interior materials, and cushioning materials for packaging.

JP 10-95024 A JP-A-10-166361 Japanese Patent Laid-Open No. 10-8393 JP 2000-265400 A

  An object of the present invention is to provide a three-dimensional molded article having a good appearance and excellent mechanical characteristics, and a fiber resin composite structure capable of easily producing a molded article by molding and having a good handleability without material dropping. To provide a body.

Such an object is achieved by the present inventions (1) to (15) below.
(1) (A) at least one resin selected from thermoplastic resins and thermosetting resins; (B) a composite fiber composed of two or more thermoplastic resin fibers having different melting points; and (C). (B) at least one fiber selected from organic fibers and inorganic fibers excluding the composite fiber, and (B) a composite of at least two fibers of one component thermoplastic resin constituting the composite fiber A fiber-resin composite structure characterized by binding between fibers.

(2) the (B) when the area occupied by the component having the lowest melting point S _l in the cross section of the composite _fiber, the area occupied by the other components were the S _h, the ratio of their occupied area S _{l /} S _h is The fiber-resin composite structure according to item (1), which is 2/8 to 8/2.

(3) The (B) composite fiber is contained in the fiber composite structure in a proportion of 1% by mass or more and 30% by mass or less, according to item (1) or item (2) Fiber resin composite structure.

(4) The fiber according to any one of items (1) to (3), wherein the composite fiber (B) has a laminated structure in which two or more components are bonded together. Resin composite structure.

(5) From the item (1), the composite fiber (B) has a core-sheath structure in which the component having the lowest melting point constitutes the sheath and the other components constitute the core. The fiber resin composite structure according to any one of items (3).

(6) The fiber resin composite structure according to any one of items (1) to (5), wherein the elongation of the composite fiber (B) at room temperature is 10 to 200%. .

(7) The melting point of the component other than the lowest melting point component constituting the (B) composite fiber is the melting point of the thermoplastic resin that may be contained in the (A) resin and the (C) fiber. Item 6. The fiber-resin composite structure according to any one of Items (1) to (6), which is lower than the melting point of the resin constituting the organic fiber that may be included.

(8) The melting point of the lowest melting point component constituting the (B) composite fiber is lower than the curing temperature of the thermosetting resin that may be contained in the (A) resin. The fiber resin composite structure according to any one of items 1) to (6).

(9) Said (C) fiber contains at least 1 sort (s) chosen from an aramid fiber, glass fiber, and carbon fiber, Any one of (1) to (8) term | claim characterized by the above-mentioned. Fiber resin composite structure.

(10) The fiber-resin composite structure according to any one of (1) to (9), wherein the (C) fiber further includes pulp fiber obtained by fibrillating organic fiber. .

(11) After the constituent material containing the (A) resin, the (B) composite fiber, and the (C) fiber is dispersed in a solvent, a papermaking agent is added to aggregate the constituent material, and the aggregate is used as a solvent. And then, after removing the solvent, heat treatment at a temperature higher than the melting point of the lowest melting component in the composite fiber (B) The fiber resin composite structure according to any one of items (1) to (10), wherein the fiber resin composite structure is obtained by performing

(12) The temperature at which the heat treatment is performed is (B) the melting point of other components excluding the lowest melting point component constituting the composite fiber, (A) the melting point of the thermoplastic resin that may be included in the resin, And (C) the melting point of the resin constituting the organic fiber that may be contained in the fiber, and the curing temperature of the thermosetting resin that may be contained in the (A) resin. The fiber-resin composite structure according to item (11), which is characterized.

(13) The fiber-resin composite structure according to any one of items (1) to (12) is cut and formed into a predetermined shape, followed by heat and pressure molding. The manufacturing method of the molded object to do.

(14) A method for producing a molded body having a concavo-convex shape, wherein the fiber resin composite structure according to any one of items (1) to (12) is similar to a final molded body by cold pressing. A method for producing a molded body, characterized by forming a predetermined shape after forming the irregularities, and then performing heat and pressure pressing.

(15) A molded article obtained by the method for producing a molded article according to (13) or (14).

  According to the present invention, it is possible to obtain a drawn product having a good appearance and excellent mechanical properties. In particular, since a light and high-strength three-dimensional molded body can be obtained, it can be suitably used for a structure such as a casing of a portable electronic device.

  Moreover, according to this invention, the fiber resin composite structure which can manufacture a molded object easily is obtained by shape | molding.

Below, it demonstrates based on preferable embodiment of this invention.
The fiber resin composite structure of the present invention is composed of (A) at least one resin selected from thermoplastic resins and thermosetting resins, and (B) fibers of two or more thermoplastic resins having different melting points. (C) (B) at least one fiber selected from organic fibers and inorganic fibers excluding the composite fiber, and (B) at least one component thermoplastic resin fiber constituting the composite fiber It is characterized in that two or more composite fibers are bound. In addition, the molded body of the present invention is obtained by the method for manufacturing a molded body of the present invention, wherein the above-mentioned fiber resin composite structure is cut and formed into a predetermined shape, and then subjected to heat and pressure molding. It is done. As a result, in the process of heat-press molding the fiber resin composite structure, the bound (B) composite fiber is elastically deformed, thereby improving the three-dimensional fillability such as drawing and the appearance. It is possible to obtain a drawn molded article having excellent mechanical properties, in particular, a light and high-strength three-dimensional molded article. The appearance of the molded body indicates the presence or absence of structural defects such as ground cracks seen on the surface, and the mechanical properties of the molded body include mechanical strength such as difficulty of deformation of the surface, fatigue strength, impact strength, etc. A general term for physical properties.

First, the fiber resin composite structure of the present invention will be described. In the fiber resin composite structure of the present invention, at least one resin selected from (A) a thermoplastic resin and a thermosetting resin can be used. Such (A) resin is not particularly limited, and examples thereof include various thermoplastic resins and various thermosetting resins, such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer. Polyolefin such as polymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, Nylon 6-12, nylon 6-66), polyimide, polyamideimide, polycarbonate (PC), poly- (4-methylpentene-1), ionomer, acrylic resin, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), poly Polyester such as butylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyethylene naphthalate (PEN), polyether, polyether ketone (PEK), polyether ether ketone (PEEK), polyether imide, polyacetal (POM), Polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer) Polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, chlorinated polyethylene Various thermoplastic elastomers such as, epoxy resins, phenol resins, urea resins, melamine resins, unsaturated polyesters, silicone resins, urethane resins, or copolymers mainly containing these, blends, polymer alloys, etc. 1 type or 2 types or more can be used in combination. Since the resin is compounded with fibers and the like by wet papermaking, it is preferably in the form of particles or fibers at room temperature and insoluble in water. Among these, as the thermoplastic resin, at least one resin selected from polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyether ketone, polyether ether ketone, polysulfone, and polyphenylene sulfide is used as the molded body. It is particularly preferable in that the heat resistance can be enhanced and the selection range of the composite fiber (B) to be used together can be widened because it has a high melting point. In addition, as the thermosetting resin, at least one resin selected from an epoxy resin, a phenol resin, a melamine resin, and a urethane resin can increase the heat resistance of the molded body, and is further used because the curing temperature is relatively high. (B) It is particularly preferable in that the selection range of the composite fiber can be widened.

  (A) As a compounding quantity of resin, Preferably it is 10-80 mass% with respect to the whole fiber resin composite structure, More preferably, it is 20-70 mass%, Most preferably, it is 30-60 mass%. Thereby, when a fiber-resin composite structure is heat-press molded, a molded body having a good appearance and less resin uneven distribution can be produced.

In the fiber resin composite structure of the present invention, (B) a composite fiber composed of two or more thermoplastic resin fibers having different melting points can be used. Such (B) composite fiber is not particularly limited. For example, a composite fiber having a laminated structure in which two or more components are bonded together, or a component having the lowest melting point constitutes the sheath. And the composite fiber etc. which have the core-sheath type | mold structure in which another component comprises a core part are mentioned, These may be used individually by 1 type, or may use 2 or more types together. (B) A composite fiber composed of two or more thermoplastic resin fibers having different melting points is subjected to a heat treatment at a temperature higher than the melting point of the lowest melting point component, such as by melting the lowest melting point component, (B) It is possible to bind between the composite fibers and between the constituent components of the fiber-resin composite structure, and to prevent the constituent components of the fiber-resin composite structure from falling off. The impact strength of the molded product obtained can be improved. Among these, a composite fiber having a core-sheath structure in which the component having the lowest melting point constitutes the sheath and the other components constitute the core is preferable from the viewpoint of thermal binding. In the conjugate fiber having a core-sheath structure, the core part and the sheath part may be concentric or eccentric.

  (B) The composite fiber preferably has an average fiber length of 1 to 30 mm, more preferably 1.5 to 20 mm, and still more preferably 2 to 15 mm. (B) When the average fiber length of the composite fiber is less than the above lower limit, (B) the formation of a network structure between the composite fibers becomes insufficient, and the effect of suppressing the ground cracking of the drawn product is sufficiently obtained. There is a fear that it is not possible. On the other hand, when the average fiber length of the (B) composite fiber exceeds the above upper limit, the (B) composite fiber cannot be uniformly dispersed in the fiber-resin composite structure, and the mechanical properties may be uneven. There is.

  Moreover, it is preferable that the fiber diameter of (B) composite fiber is 5-60 micrometers, and it is more preferable that it is 10-30 micrometers. (B) If the average fiber diameter of the composite fiber is within the above range, the formation of a network structure in which the low (B) composite fiber is bound is sufficient, and further, uniform dispersibility in the fiber-resin composite structure Is granted. When the fiber diameter of the (B) composite fiber is below the lower limit, the binding force for binding the (B) composite fibers and (B) the composite fibers and the (C) fibers may be reduced. is there. In addition, when the fiber diameter of the (B) composite fiber exceeds the upper limit, the (B) composite fiber is likely to be unevenly distributed in the fiber-resin composite structure, and the dispersibility is lowered. There is a risk.

(B) The component having the lowest melting point in the composite fiber includes the melting point T _ml of the thermoplastic resin that may be included in the resin (A) constituting the fiber resin composite structure and (C) the fiber. It is preferable that the melting point of the resin constituting the good organic fiber is lower. In addition, the component (B) having the lowest melting point in the composite fiber preferably has a melting point T _ml lower than the curing temperature of the thermosetting resin that may be contained in the (A) resin. More specifically, the melting point T _ml is preferably 80 to 200 ° C, particularly preferably 90 to 160 ° C. Thereby, (B) the component having the lowest melting point in the composite fiber can be melted to form a network structure without causing any trouble to the (A) resin and (C) fiber constituting the fiber resin composite structure. Therefore, (B) the binding property of the contact points between the composite fibers, and (B) the contact points between the composite fibers and other constituent components of the fiber resin composite structure (A) resin, (C) fibers, etc. The binding property is improved, and a sufficient network structure can be formed. On the other hand, (B) the other components excluding the lowest melting point component in the composite fiber have the melting point T _mh constituting the fiber resin composite structure (A) the melting point of the thermoplastic resin that may be contained in the resin, and ( C) It is preferable that it is lower than melting | fusing point of resin which comprises the organic fiber which may be contained in a fiber. In addition, (B) other components excluding the lowest melting point component in the composite fiber, the melting temperature T _mh of which constitutes the fiber resin composite structure (A) The curing temperature of the thermosetting resin that may be included in the resin Is preferably lower. More specifically, the melting point T _mh is preferably 150 to 250 ° C, and particularly preferably 160 to 200 ° C. As a result, at the time of heating the initial press forming that remains in a temperature range lower than T _mh at the time of forming the final formed body, (B) the fibrous structure of the fiber-resin composite structure is elastically deformed. In the stage where the cracking is suppressed and T _mh is reached to the vicinity of the molding set temperature, (B) the network structure of the composite fiber disappears, and the fiber resin composite structure forms the molded body (A) resin. (C) It becomes possible to promote local reorientation of the fiber. For this reason, it is possible to effectively utilize the elastic deformation in the heating stage at the initial stage of press molding. In particular, when (A) a thermosetting resin is used as the resin, (B) the melt-solidified component of the composite fiber is dispersed in the matrix resin. Therefore, it is possible to improve mechanical properties such as impact strength of the molded body.

(B) The temperature difference between the melting point T _mh of the other components excluding the lowest melting point component of the composite fiber and the melting point T _ml of the lowest melting point component, that is, ΔT _m = T _mh −T _ml is 10 to 10 It is preferable that it is 150 degreeC, and it is especially preferable that it is 20-100 degreeC. As a result, (B) while maintaining the strength of the other components except the lowest melting point component of the composite fiber, the lowest melting point component melts to form a network structure, and elastic deformation during uneven shaping Can be effectively expressed, and further, it is possible to obtain a molded article having a good appearance and good mechanical properties.

Also, (B) in the transverse plane of the composite fibers, the area ratio S _{l /} S _h of the occupied area S _h of the other ingredients except the lowest melting point component and the occupied area S _l component of the lowest melting point, the composite From the viewpoint of the binding property between the contacts of the fibers, it is preferably 2/8 to 8/2, and particularly preferably 3/7 to 7/3. When S ₁ / S _h is less than the above lower limit value, the binding property between the fibers becomes insufficient, so that there is a possibility that dropping of the constituent components of the fiber resin composite structure cannot be suppressed. Moreover, when the said upper limit is exceeded, although binding property is good, there exists a possibility that appearance defects, such as a ground crack, may arise in a molded object.

  Further, the elongation at room temperature of the (B) composite fiber is preferably 10 to 200%, more preferably 50 to 150%. This makes it possible to perform three-dimensional shape shaping while maintaining the entangled structure of (B) composite fiber and (C) fiber by elastic deformation of the network structure formed in the fiber resin composite structure It becomes. (B) When the elongation at room temperature of the composite fiber is less than the above lower limit value, the network structure is likely to be broken by deformation, so that there is a possibility that a ground crack may occur in the molded body. Moreover, when the elongation at room temperature of the (B) composite fiber exceeds the above upper limit, the network structure is retained, but the elastic modulus is low, so the effect of suppressing the cracking of the molded body may be reduced. .

  As such (B) composite fiber, for example, NBF (E), NBF (H) (both composite fibers having a core-sheath structure) manufactured by Daiwabo Polytech Co., Ltd., manufactured by Ube Nitto Kasei Co., Ltd. UNK chop (REC) ((composite fiber having a core-sheath structure) and the like are available as commercial products, but are not limited thereto.

  Moreover, as a compounding quantity of (B) composite fiber, it is preferable that it is 1-30 mass% with respect to a fiber resin composite structure, and it is more preferable that it is 5-20 mass%. Thereby, three-dimensional molding processability can also be provided, maintaining the mechanical characteristics of a molded object high.

  In the fiber resin composite structure of the present invention, at least one fiber selected from organic fibers and inorganic fibers excluding (C) and (B) composite fibers can be used. Such (C) fiber may be composed of any material, for example, polyester fiber, polyarylate fiber, polyamide fiber, para-type wholly aromatic polyamide fiber or copolymer thereof, meta-type aramid fiber And its copolymers, polyphenylene sulfide fibers, allyl fibers, polyimide fibers, polyparaphenylene benzobisoxazole fibers, polyparaphenylene benzobisthiazole fibers, polyetheretherketone fibers, polytetrafluoroethylene fibers, cellulose fibers In addition to fiber, glass fiber, carbon fiber, metal fiber, ceramic fiber, rock wool, cotton fiber, silk fiber, wood fiber and the like can be mentioned. These can be used alone or in combination of two or more. May be.

  Among these (C) fibers, at least one selected from aramid fibers, glass fibers, and carbon fibers is preferable. Since these fibers have sufficient tensile strength and excellent weather resistance, they are useful as fibers for reinforcing the molded body.

  (C) The average fiber length of the fibers is preferably 0.5 to 20 mm, more preferably 1 to 15 mm. (C) If the average fiber length of the fibers is within the above range, (C) the dispersion state of the fibers becomes uniform, so that the mechanical properties of the molded body can be improved uniformly. In addition, when the average fiber length of (C) fiber is less than the said lower limit, the probability that (C) fibers will be entangled with each other decreases, and the mechanical properties of the molded article may not be sufficiently improved. On the other hand, when the average fiber length of (C) fibers exceeds the above upper limit, there is a possibility that a large number of fibers are entangled and the fibers cannot be uniformly dispersed.

  Moreover, it is preferable that the fiber diameter of (C) fiber is 0.5-60 micrometers, and it is more preferable that it is 1-30 micrometers. (C) If the fiber diameter of the fiber is within the above range, sufficient tensile strength and uniform dispersibility are imparted to the fiber. In addition, when the fiber diameter of (C) fiber is less than the said lower limit, depending on the constituent material of (C) fiber, there exists a possibility that the tensile strength of (C) fiber may fall. On the other hand, when the fiber diameter of the (C) fiber exceeds the above upper limit, the (C) fiber cannot be uniformly dispersed in the molded body, and the mechanical characteristics may be non-uniform.

  Moreover, (C) As a compounding quantity of a fiber, it is preferable that it is 10-90 mass% with respect to a fiber resin composite structure, and it is more preferable that it is 20-80 mass%. Thereby, the mechanical characteristic of a molded object can be improved.

  In addition, the (C) fiber may be subjected in advance to a surface treatment for improving the adhesion and affinity with the (A) resin. Examples of the surface treatment method include ultraviolet irradiation treatment, electron beam irradiation treatment, plasma irradiation treatment, surface layer formation treatment, and the like.

  Among these, examples of the surface layer include coupling agents such as silane coupling agents and titanium coupling agents, various surfactants, and various oil agents.

  The (C) fiber used in the present invention can further include pulp fiber obtained by fibrillating organic fiber. The pulp fiber is not particularly limited, but examples thereof include cellulose fibers such as linter pulp and wood pulp, natural fibers such as kenaf, jute and bamboo, para-type wholly aromatic polyamide fibers and copolymers thereof, aromatic Examples include pulp fibers obtained by fibrillating organic fibers such as group polyester fibers, polybenzazole fibers, meta-type aramid fibers and copolymers thereof, acrylic fibers, acrylonitrile fibers, polyimide fibers, and polyamide fibers.

  The method for fibrillation of the organic fiber is not particularly limited, but the fibrillated organic fiber can be produced by beating with a beater or a refiner as a slurry in which the organic fiber is dispersed in water. Although the slurry concentration at the time of beating is arbitrary, solid content concentration of 0.1-10 mass% is preferable.

  Moreover, as a compounding quantity of a pulp fiber, Preferably it is 1-50 mass% with respect to a fiber resin composite structure, More preferably, it is 3-30 mass%, Most preferably, it is 5-20 mass%. Thereby, the yield of the resin particles is high, a fiber resin composite structure with good handleability in which resin particle dropping is suppressed can be obtained, and the mechanical properties of the molded body formed by heating and pressing can be improved.

  A paper making agent can be added to the fiber resin composite structure of the present invention for the purpose of improving the material yield and the like. The paper making agent is not particularly limited, and examples thereof include thermoplastic resins such as acrylic polymers, vinyl polymers, polyurethanes, polyamides, polyesters, and polyethylene oxides. Or 2 or more types are used. The thermoplastic resin used as the papermaking agent preferably has at least one functional group selected from an amino group, an epoxy group, a carboxyl group, an oxazoline group, a carboxylate group and an acid anhydride group. You may have the above functional groups. Among these, a thermoplastic resin having an amino group is more preferable.

An additive can be further added to the fiber resin composite structure of the present invention. Additives include fillers, conductivity enhancers, flame retardants, flame retardant aids, pigments, dyes, lubricants, mold release agents, compatibilizers, dispersants, crystal nucleating agents, plasticizers, heat stabilizers, oxidation Examples thereof include an inhibitor, an anti-coloring agent, an ultraviolet absorber, a fluidity modifier, a foaming agent, an antibacterial agent, a vibration control agent, a deodorant, a slidability modifier, and an antistatic agent.

  Fillers include crushed glass, mica, talc, kaolin, sericite, bentonite, zonotolite, sepiolite, smectite, montmorillonite, wollastonite, silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, molybdenum disulfide Examples thereof include titanium oxide, zinc oxide, antimony oxide, aluminum oxide, zinc oxide, calcium polyphosphate, graphite, barium sulfate, magnesium sulfate, zinc borate, calcium borate, aluminum borate whisker, and potassium titanate whisker.

  Next, an example is given and demonstrated about the manufacturing method of the fiber resin composite structure of this invention, However, It is not limited to this method. First, a slurry composition is prepared by dispersing constituent materials including (A) resin, (B) composite fiber, and (C) fiber in a solvent such as water or alcohol. The order of charging the constituent materials into the solvent when preparing the slurry composition is not particularly limited, and the solvent is sequentially checked while confirming the dispersion state of (A) resin, (B) composite fiber, and (C) fiber. Can be thrown in. Moreover, an additive and a filler can be mixed in the adjustment process of this slurry composition. A known mixer such as a pulper can be used for mixing the slurry composition. After the constituent materials are uniformly stirred and mixed, a papermaking agent is added to agglomerate the constituent materials to produce a slurry composition (aggregate) for papermaking. In these steps, a known antifoaming agent used in general papermaking can be used for the purpose of suppressing the generation of bubbles during mixing.

  Next, the slurry composition (aggregate) is made to obtain a fiber resin composite structure. Paper making can be carried out using a continuous paper machine such as a long paper machine or a round paper machine, or using a known paper machine such as a box-type paper machine. (B) The temperature is lower than the melting point of the lowest melting point component of the composite fiber) and is wound on a roller. In the case of a batch type paper machine such as a box type paper machine, the paper-like material after paper making is held in a metal frame or the like, and is lower than the melting point of the lowest melting point component of the composite fiber (B) with a dryer or the like Adjust the time appropriately according to the temperature and dry. Next, (B) the component having the lowest melting point in the composite fiber is melted by heat treatment at a temperature higher than the melting point of the component having the lowest melting point of the composite fiber (B). It is set as the state which the fiber of the thermoplastic resin of a component has couple | bonded between at least 2 or more composite fibers. By these operations, (B) the fiber-resin composite structure of the present invention in which the network structure is sufficiently formed by binding between the composite fibers or between the constituent components of the fiber-resin composite structure is manufactured. be able to. The heat treatment temperature is higher than the melting point of the component (B) having the lowest melting point of the composite fiber, and (B) the melting point of other components excluding the component having the lowest melting point of the composite fiber, (C) the melting point of the resin constituting the organic fiber that may be contained in the fiber, and (A) a temperature lower than the melting point of the thermoplastic resin that may be contained in the resin, or (A) contained in the resin It is more preferable that the temperature is lower than the curing temperature of the thermosetting resin that may be used. Thereby, without impairing the moldability of the fiber-resin composite structure, (C) the fibers used for reinforcement remain in the fiber shape, and (A) when a thermosetting resin is used as the resin, partially (B) A fiber-resin composite structure with good handleability that does not drop off, breaks, or collapses by being able to generate a network structure of composite fibers without causing gelation. Can be obtained.

The molded body of the present invention is formed by heating and pressing the fiber resin composite structure of the present invention. Below, although an example is given and demonstrated about the manufacturing method of the molded object of this invention, it is not limited to this method. As a preparation for producing a molded body, preforming (cold press) is performed to shape the fiber-resin composite structure into an uneven shape similar to the molded body at a temperature lower than the melting point of the component (B) having the lowest melting point in the composite fiber. It is preferable to perform cutting except for portions not subjected to molding. The fiber resin composite structure can be obtained by performing pressure-clamping while adjusting the temperature and time in which the elastic shape retention force of the network structure by the (B) composite fiber in the fiber resin composite structure can be used without preforming. While holding the entanglement of the (B) composite fiber and (C) fiber in the inside, it is possible to obtain a molded body by shaping the drawn shape, but it becomes easy to place it in the molding die through pre-molding, Prevention of misalignment of fiber-resin composite structure during mold clamping, improvement of preheating efficiency by mold, and effective use of elastic deformation of network structure formed of (B) composite fiber in fiber-resin composite structure Therefore, it is possible to reliably suppress the cracking of the molded body. Also, by cutting the preformed fiber resin composite structure, trimming of unnecessary parts can be reduced, and by removing unnecessary parts, the uniformity of mold clamping during pressure heating is improved and a good molded body is obtained. Can be obtained.

  As a method of pre-molding the fiber resin composite structure to form a concavo-convex shape similar to the molded body, the reference surface to be the molded body can be fixed with a solid surface, and the surface facing the reference surface can be compressed by pressure. There is no particular limitation as long as it is a method capable of compressing to a thickness of 150 to 600% of the thickness of the molded body. For example, the press method which pressurizes and compresses a fiber resin composite structure with two types is mentioned. In the case of the pressing method, a mold having the same shape as that of the molded body is used on the surface side serving as the reference surface, and the mold that shapes the opposite surface side has a clearance of 150 to 600 from the thickness of the molded body when the mold is clamped. It is better to adjust the unevenness depth of the mold so that it becomes%. When the clearance of the preform is less than the lower limit, when the fiber-resin composite structure is three-dimensionally deformed and compressed, the structure may be partially wrinkled or twisted. In addition, when the above upper limit is exceeded, compression by preliminary molding becomes insufficient, and partial wrinkles and warpage are generated in the structure when the pressure-heating molding is performed to obtain a molded body, and the appearance of the molded body is also deteriorated. There is a risk that.

  In addition, in the pre-molding process using the press method, separators may be placed on both sides of the fiber-resin composite structure from the viewpoint of shape shaping and mold removal. Depending on the shape of the drawn shape, the type of separator can be changed. May be. For example, in the case of a molded body shape having a convex surface and a concave surface with a reference surface as an outer convex surface, such as a box, the stretch rate of the spunbond sheet, plastic net, and plastic woven fabric is 200 to 400 on the convex surface side where tensile shear strain occurs. %, And it is preferable to use a rigid separator. Moreover, since the thickness change due to compression of the fiber-resin composite structure is large on the concave side where compression shear strain occurs, the stretch rate of nylon woven fabrics such as thin spunbond sheets and stockings is 300 to 500% and the rigidity is low. It is preferable to use a separator.

  As a method of cutting the fiber-resin composite structure, a punching process using a Thomson blade, a water jet process, an air jet process, a sand blast process, a process method of spraying a processing medium such as a shot blast process, a laser process method, or the like is used. be able to. Especially, water jet processing is preferable from the point which does not have the restriction | limiting of the height direction of the fiber resin composite structure which shape | molded the solid shape without the heat damage.

Although it does not specifically limit as a heat press molding method of a fiber resin composite structure, It can shape | mold by a heat press, the heat compression molding by a metal mold | die, etc. The method for the hot press is not particularly limited, and can be performed by using a known press machine. At this time, there are no particular restrictions on the pressing temperature, pressing pressure, and pressurization / heating time. (A) Resin composition and melting point (when thermoplastic resin is the main resin component) or curing temperature (thermosetting If the resin is the main resin component), and if it is performed under conditions that take into account the thickness and density of the molded article, there is no particular problem. Higher than the melting point of the thermoplastic resin, which is a resin component, (B) higher than the melting point T _{mh of the} component excluding the low melting point of the composite fiber, and (C) from the melting point of the organic fiber in the fiber It is preferable to adjust the press temperature so that the temperature is low. Moreover, when (A) resin uses thermosetting resin as the main resin component, it is a temperature equivalent to its curing temperature, and (B) at a temperature higher than the melting point T _{mh of the} component excluding the low melting point of the composite fiber. And (C) It is preferable to adjust the press temperature so that the temperature is lower than the melting point of the organic fiber in the fiber. By adjusting to such a press temperature, at the time of heating and pressure molding, in the heating stage of the initial stage of molding that remains in a temperature range lower than T _mh , (B) the network structure of the composite fiber is elastically deformed. In the stage where the ground cracking of the fiber resin composite structure is suppressed and the melting point and _Tmh of the thermoplastic resin are reached to reach the molding set temperature, (B) the network structure of the composite fiber disappears, and the fiber resin composite structure It becomes possible to promote local reorientation of (A) resin and (C) fiber when forming a molded body shape.

  Further, when the resin (A) contains a thermosetting resin as a main resin component, post-curing can be performed for the purpose of completely curing the thermosetting resin. The post-curing conditions are not particularly defined and can be appropriately determined in consideration of the curing temperature of the used matrix resin, the melting point of the organic fibers in the fiber (C), the heat-resistant temperature required from the use environment, etc. The curing temperature can be about ± 50 ° C.

  Although the present invention has been described above, the present invention is not limited to this. For example, an arbitrary component (for example, a coating layer) may be added to the surface of the molded body.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measurement method of physical property items used in this example was as follows.

1) Tensile strength of molded article Tensile strength was measured according to the following test methods and conditions.
Standards: JIS K7113 Tensile testing method for plastics Temperature: Room temperature Testing machine: Shimadzu Autograph AG-5kNUS MS (manufactured by Shimadzu Corporation)
Test piece: JIS K7113 Dumbbell No. 1 (1/2) Test speed: 1 mm / min
Distance between grips: 58mm
The measurement results are shown in Table 1.

Example 1
First, para type aramid fiber (“Technora (registered trademark) T32PNW 3-12” manufactured by Teijin Techno Products Co., Ltd.) having an average fiber length of 3 mm and a fiber diameter of 12 μm, a phenol resin powder having an average particle diameter of 15 μm and a softening point of 75 ° C. (Phenol resin powder made by Sumitomo Bakelite Co., Ltd. mixed with PR-50731, PR-51723, PR-53529 at a mass ratio of 1: 1: 1) and aramid pulp (Toray Dupont with a freeness of 417 ml CSF) "Kevlar (registered trademark) Pulp 1F303"), an average fiber length of 5 mm, a fiber diameter of 18 µm, a melting point of the sheath component of 100 ° C, a melting point of the core component of 165 ° C, an area S ₁ of the sheath component, area ratio _S l / _{S h} of the area _{S h} of the core component is 62/48, elongation of 100% of the core-sheath type composite fiber 1 (Daiwabo Polytec Co. NBF (E) ) Was mixed at a mass ratio of 31: 45: 15: 9 and dispersed in water so that the solids concentration was 0.5% by mass to prepare a dispersion.
Subsequently, 800 ppm of polyethylene oxide based on the solid content is added to the dispersion as a papermaking agent to prepare a dispersion slurry composition, which is made, dehydrated, dried at 80 ° C. for 2 hours, and then at 105 ° C. for 30 minutes. A heat-treated fiber resin composite structure having a thickness of 5 mm was obtained. The produced fiber-resin composite structure was good in handling without any loss of resin components.
Next, using a female mold with an inner diameter of length × width × depth = 60 × 120 × 10 mm and a curvature of 2R on each side, and a male mold with a female mold and a clearance of 3 mm, room temperature (25 ° C.) for 30 seconds. The sample was pressed at a surface pressure of 4.8 MPa and preformed. Thereafter, a portion unnecessary for molding was punched out with a Thomson blade, and a fiber-resin composite structure was drawn and formed without cracking.
Next, this draw-shaped fiber resin composite structure was hot-pressed at 200 ° C. for 10 minutes at a surface pressure of 300 MPa using a hot press machine, and the length × width × depth = 60 × 120 × 10 mm for each side. Produced a box-shaped molded article having an average thickness of 1 mm of the wall portion having a curvature of 2R. The obtained molded article had a good appearance with no wrinkles, creases and cracks at the four corners of the bottom and bottom and at a right angle.
As a result of producing a test piece for a tensile test by punching from the bottom surface of this box-shaped molded body (using a Thomson blade produced in a dumbbell shape) and measuring the tensile strength, the tensile strength was 200 MPa.
Further, a flat fiber resin composite structure was heated and pressed at 200 ° C. for 10 minutes at a surface pressure of 300 MPa to produce a 1 mm-thick flat plate, and then punched from the flat plate (made into a dumbbell shape). Using a Thomson blade), a test piece for a tensile test was similarly prepared and the tensile strength was measured. As a result, the tensile strength was 203 MPa, which was the same result as that of a punched product from a box-shaped molded body.
From the results of the tensile strength of the punched product from the box-shaped molded product and the tensile strength of the punched product from the flat plate molded product, it was molded while maintaining the entanglement of fibers and pulp fibers even when the three-dimensional shape was formed Thus, it is presumed that a molded article having no mechanical cracking and excellent mechanical properties was obtained.

(Example 2)
The same as in Example 1 except that the mass ratio of the para-type aramid fiber, phenol resin powder, aramid pulp, and core-sheath type composite fiber 1 used in the fiber-resin composite structure was 40: 36: 15: 9. Thus, a molded body having a length × width × depth = 60 × 120 × 10 mm and an average thickness of 1 mm was obtained. The produced fiber-resin composite structure was good in handling without any loss of resin components. Further, the produced molded body had a good appearance with no wrinkles, twists or ground cracks occurring at the four corners of the bottom and bottom and at the right angle.
Similarly to Example 1, a box-shaped molded body and a plate-shaped molded body were produced from the fiber-resin composite structure of Example 2, and the tensile strength was evaluated with a punched test piece from each. The test piece tensile strength of the body was 261 MPa, and the test piece tensile strength of the plate-like molded body was 258 MPa, and good strength characteristics were maintained regardless of the shape of the molded body.

(Comparative Example 1)
Except for the core-sheath type composite fiber 1 from the formulation of Example 1, except that the para-aramid fiber, the phenol resin powder, and the aramid pulp were mixed at a mass ratio of 40:45:15, the same as in Example 1, A fiber resin composite structure was obtained. A molded body having a length × width × depth = 60 × 120 × 10 mm and an average thickness of 1 mm was obtained. In the produced fiber-resin composite structure, the resin component was removed more than in Example 1, and the handleability was lowered.
Next, as a result of preforming in the same manner as in Example 1, ground cracks occurred on the bottom surface of the squeeze-shaped fiber resin composite structure, and the entanglement of fibers and pulp fibers was broken. I couldn't.

Example 3
Except for the pre-molding that gives the fiber-resin composite structure a concavo-convex shape similar to the molded body, the length x width x depth = 60 x 120 x 10 mm and the average thickness is 1 mm, as in Example 1. A molded body was obtained. The molded body is free of wrinkles, creases and cracks at the four corners of the bottom and bottom and at right angles, and has a good appearance, and is punched from a box-shaped molded body and a flat molded body ( The tensile strength characteristics measured by producing a test piece with a dumbbell-shaped Thomson blade) are 197 MPa for the box-shaped molded body and 200 MPa for the plate-shaped molded body. Both were good.
The heat and pressure molding temperature for producing the molded body is 200 ° C., and the low melting point component (sheath component) and the high melting point component (core component) of the core-sheath type composite fiber 1 which is a composite fiber forming a network structure. Although the temperature is higher than any of the above, in the initial stage of mold clamping for shaping the concavo-convex shape, the network structure formed by the composite fiber is partially due to the process of raising the temperature from room temperature to a molding temperature of 200 ° C. It is presumed that the ground cracking of the molded product could be suppressed by elastically deforming while maintaining the structure without being melted and maintaining the entanglement of fibers and pulp fibers.

(Comparative Example 2)
Except that the core-sheath type composite fiber 1 was removed from the blending of Example 1 and the mass ratio of para-type aramid fiber, phenol resin powder, and aramid pulp was mixed as 40:45:15, and heat treatment was not performed. After obtaining the fiber-resin composite structure in the same manner as in Example 1, a box-like molded product was obtained without performing preforming in the same manner as in Example 3. The molded body had wrinkles and twists at the four corners of the bottom, and partial ground cracks occurred at the bottom and the right-angled parts rising from the bottom. Tensile strength was measured by preparing a box-shaped molded body and a plate-shaped molded body from the fiber-resin composite structure of Comparative Example 2, punching out the molded body (using a Thomson blade fabricated in a dumbbell shape), and measuring As a result of evaluating the strength, the tensile strength of the plate-shaped molded body was as good as 258 MPa, but the tensile strength of the test piece processed from the bottom surface of the box-shaped molded body was 80 MPa. The decrease in mechanical strength is presumed to be caused by the occurrence of a portion (ground crack) in which the fibers and pulp fibers are entangled and the ratio of the resin volume increased at that portion.

Example 4
The mass ratio of the para-type aramid fiber, phenol resin powder, aramid pulp, and core-sheath type composite fiber 1 used for the fiber-resin composite structure is mixed as 24: 45: 15: 16, and the fiber is formed in the same manner as in Example 1. A resin composite structure was produced. Next, using a female mold having an inner diameter of length × width × depth = 60 × 120 × 35 mm and a curvature of 2R on each side and a male mold with a female mold and a clearance of 2 mm, a surface pressure of 4 for 30 seconds at room temperature. Pressed at 8 MPa and preformed. Thereafter, a portion unnecessary for molding was trimmed with a water jet (water pressure = 200 MPa, processing medium = tap water, nozzle diameter = 100 μm), and a fiber-resin composite structure formed by drawing without a crack was produced. Then, this draw-shaped fiber resin composite structure was subjected to hot pressing at 200 ° C. for 10 minutes at a surface pressure of 300 MPa using a hot press machine, and the length × width × depth = 60 × 120 × 35 mm for each side. Produced a box-shaped molded article having an average thickness of 1 mm of the wall portion having a curvature of 2R. The molded body had a good appearance with no wrinkles, creases and cracks at the four corners of the bottom and bottom and at the right angle.
Further, similarly to Example 1, a box-shaped molded body and a plate-shaped molded body were produced from the fiber-resin composite structure of Example 4, and punched from the molded body (using a Thomson blade produced in a dumbbell shape). As a result of producing a test piece and evaluating the measured tensile strength, the test piece tensile strength of the box-shaped formed body is 153 MPa, and the test piece tensile strength of the plate-shaped formed body is 151 MPa, which is good regardless of the shape of the formed body. The strength characteristics were maintained.

(Example 5)
The same para-aramid fiber, phenol resin powder, and aramid pulp used in Example 1 were used. (B) Instead of using the core-sheath-type composite fiber 1 as the composite fiber, the average fiber length was 5 mm, the fiber diameter was 15 μm, and the sheath melting point 130 ° C. components, a melting point of 165 ° C. of the core component, the area _{S l} of the sheath component, the area ratio _S l / _{S h} of the area _{S h} of the core component is 46/54, elongation 40% core-sheath Type composite fiber 2 (UNK chop (REC) manufactured by Ube Nitto Kasei Co., Ltd.) is mixed at a mass ratio of 31: 45: 15: 9 so that the solids concentration is 0.5% by mass. A dispersion was prepared by dispersing in water.
Next, 800 ppm of polyethylene oxide based on the solid content is added to the dispersion as a papermaking agent to prepare a dispersion slurry composition, which is papermaking, dewatered and dried at 80 ° C. for 2 hours, and then at 135 ° C. for 5 minutes. It heat-processed and the fiber resin composite structure of thickness 4.5mm was obtained. The produced fiber-resin composite structure was good in handling without any loss of resin components.
Next, after preforming in the same manner as in Example 1, heat and pressure molding was performed in the same manner as in Example 1 to obtain a molded body having a length × width × depth = 60 × 120 × 10 mm and an average thickness of 1 mm. . The molded body had a good appearance with no wrinkles, creases and cracks at the four corners of the bottom and bottom and at the right angle. Further, similarly to Example 1, a box-shaped molded body and a plate-shaped molded body were produced from the fiber-resin composite structure of Example 5, and punched from the molded body (using a Thomson blade produced in a dumbbell shape). As a result of producing a test piece and evaluating the measured tensile strength, the test piece tensile strength of the box-shaped molded product is 210 MPa, and the test piece tensile strength of the plate-shaped molded product is 215 MPa, which is good regardless of the shape of the molded product. The strength characteristics were maintained.

(Example 6)
The same para-aramid fiber, phenol resin powder, and aramid pulp used in Example 1 were used. (B) Instead of using the core-sheath type composite fiber 1 as the composite fiber, the average fiber length was 5 mm, the fiber diameter was 18 μm, and the sheath melting point 128 ° C. components, a melting point of 165 ° C. of the core component, the area _{S l} of the sheath component, the area ratio _S l / _{S h} of the area _{S h} of the core component is 40/60, 70% elongation of the core-sheath Type composite fibers 3 (NBF (H) manufactured by Daiwabo Polytech Co., Ltd.) are mixed at a mass ratio of 34: 45: 15: 6, and water is added so that the solid concentration is 0.5 mass%. To prepare a dispersion.
Next, 800 ppm of polyethylene oxide based on the solid content is added to the dispersion as a papermaking agent to prepare a dispersion slurry composition, which is papermaking, dehydrated, dried at 80 ° C. for 2 hours, and then at 133 ° C. for 5 minutes. A heat-treated fiber resin composite structure having a thickness of 5 mm was obtained. The produced fiber-resin composite structure was good in handling without any loss of resin components.
Next, after preforming in the same manner as in Example 1, heat and pressure molding was performed in the same manner as in Example 1 to obtain a molded body having a length × width × depth = 60 × 120 × 10 mm and an average thickness of 1 mm. . The molded body had a good appearance with no wrinkles, creases and cracks at the four corners of the bottom and bottom and at the right angle. Further, similarly to Example 1, a box-shaped molded body and a plate-shaped molded body were produced from the fiber-resin composite structure of Example 6, and punched from the molded body (using a Thomson blade produced in a dumbbell shape). As a result of evaluating the tensile strength measured by preparing the test piece in Fig. 5, the test piece tensile strength of the box-shaped molded body was 235 MPa, and the test piece tensile strength of the plate-shaped molded body was 230 MPa, regardless of the shape of the molded body. Good strength characteristics were maintained.

According to the present invention, a drawn article having a good appearance and excellent mechanical properties, particularly a light and high-strength three-dimensional article can be obtained. It can be suitably used.

Claims (8)

(A) a phenolic resin ;
(B) A composite fiber composed of two or more thermoplastic resin fibers having different melting points , wherein the lowest melting point component constitutes the sheath portion, and the other components constitute the core portion. A composite fiber having a structure ;
(C) an aramid fiber ;
Including
(B) A fiber-resin composite structure characterized in that at least two or more composite fibers are bound by one component thermoplastic resin fiber constituting the composite fiber ,
When the occupied area of the component having the lowest melting point in the cross section of the (B) composite fiber is S1 and the occupied area of the other components is Sh, the ratio S1 / Sh of these occupied areas is 2/8 to 8/2. And
(A) The compounding quantity of a phenol resin is 30-60 mass% with respect to the whole fiber resin composite structure,
(B) The compounding amount of the composite fiber is 5 to 20% by mass with respect to the fiber resin composite structure,
(C) The fiber resin composite structure whose fiber compounding quantity is 20-80 mass% with respect to the fiber resin composite structure. The (B) melting point of the other components excluding the lowest melting point component constituting the composite fiber may be contained in the (A) resin and contained in the (C) fiber. 2. The fiber-resin composite structure according to claim 1, wherein the fiber-resin composite structure is lower than the melting point of the resin constituting the good organic fiber. (B) the melting point of the lowest-melting component constituting the composite fibers, the (A) according to claim 1, wherein the lower than the curing temperature of the thermosetting resin which may be contained in the resin Fiber resin composite structure. The fiber resin composite structure according to any one of claims 1 to 3 , wherein the (C) fiber further includes a pulp fiber obtained by fibrillating an organic fiber. After the constituent material containing the (A) resin, the (B) composite fiber, and the (C) fiber is dispersed in a solvent, a papermaking agent is added to aggregate the constituent material, and the aggregate is separated from the solvent. Then, a composite material composition obtained by removing the solvent,
After removal of the solvent, the (B) in any one of the preceding claims, characterized in that it is obtained by performing heat treatment at a temperature higher than the melting point of the component having the lowest melting point in the composite fibers 4 The fiber-resin composite structure described. A method for producing a molded body, comprising: heating and pressing after the process of cutting the fiber-resin composite structure according to any one of claims 1 to 5 into a predetermined shape. A method for producing a molded article having an uneven shape,
The fiber-resin composite structure according to any one of claims 1 to 5 is subjected to heat and pressure pressing through a process of forming irregularities similar to the final molded body by cold pressing and then forming into a predetermined shape. The manufacturing method of the molded object characterized by these. A molded article obtained by the method for producing a molded article according to claim 6 or 7 .