JP2023124489A - Manufacturing method for laminated molded product, and laminated molded product - Google Patents

Abstract

To provide a manufacturing method for laminated molding that enables lower cost by shortening tact time and improving production efficiency without lowering mechanical properties.SOLUTION: The method for manufacturing a laminate molded body includes, as one cycle, (1)setting a metal member, an interlaminar adhesive, and a fiber-reinforced resin material in a press device in which the temperature of a mold is maintained within the range of 160 to 240°C, (2) closing the mold and performing hot press molding to laminate and composite the metal member and the fiber-reinforced resin material, and at the same time, performing shaping, (3) removing the laminate-integrated laminate-formed body from the press device at a temperature within -10°C of the mold temperature in step (1), and (4) adjusting the mold temperature to the temperature of process (1). In the method, the matrix resin of the fiber-reinforced resin layer is a cross-linked hardened product of a resin composition including a phenoxy resin and the tact time from process (1) to (4) is less than 10 minutes.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a method for producing a laminated molded article containing fiber-reinforced resin and a laminated molded article.

In recent years, due to environmental problems, the replacement of metals with fiber-reinforced resins has been attracting attention as an effort to improve fuel efficiency in the automobile and aviation industries in order to reduce the weight of car bodies and airframes. Fiber reinforced resin (FRP) is a material made by reinforcing thermoplastic resin or thermosetting resin with reinforcing fibers such as carbon fiber. Application research has been conducted in a wide range of fields such as wind power generation and sporting goods, and it has already been used.

Among them, FRP using thermoplastic resin can be molded and shaped by heating, has high productivity, is easy to perform secondary processing such as welding, has electrical insulation, and does not corrode. It is certain that it will be widely used in various fields in the future because of its features such as excellent recyclability.

FRP processing includes autoclave molding, oven molding, press molding, RTM/VaRTM method, pultrusion molding, etc. Among these, press molding is desirable from the viewpoint of high productivity and the ability to obtain high-quality laminates. It is said that

However, FRP is less malleable than metal, and if press-molded at the same speed as metals such as iron, it breaks or wrinkles. Furthermore, if the prepreg is heated too much for molding, the viscosity of the resin will drop too much and the resin will melt, making it impossible to form a clean molded product. , there is a problem that it becomes a molding defect. Further, press molding of FRP material impregnated with a thermosetting resin requires a long time to complete curing, resulting in a long tact time. In the press molding of FRP material impregnated with a thermoplastic resin, it takes time to cool the mold to the solidification temperature of the resin at the time of demolding, resulting in a long tact time.

In order to solve such problems, Patent Document 1 discloses a method for obtaining a laminated molded product with a high degree of perfection by press molding in a short period of time.

In addition, Patent Documents 2 and 3 disclose FRP molding materials that contain phenoxy resin, epoxy resin, and a cross-linking agent as essential components as FRP matrix resins, and that can suppress changes in mechanical properties in a high-temperature environment through a cross-linking reaction. and a laminate molded body using the same and a method for producing the same are disclosed, and an embodiment in which a laminate molded body is obtained by pressing for about 10 minutes is disclosed.

In addition, in Patent Document 4, a composite of carbon fiber reinforced resin (CFRP) with a phenoxy resin matrix and metal is heated in a mold preheated to 230 ° C. for 5 minutes to reduce the molding tact time. is disclosed.

JP 2021-102274 A WO2018/061516 WO2018/124215 JP 2021-126776 A

The laminate molded body disclosed in Patent Documents 1 and 2 has the problem that the mold needs to be cooled to the solidification temperature of the resin when the mold is removed from the press molding, and the tact time is lengthened for cooling and reheating. be. Moreover, the laminate molded body disclosed in Patent Document 3 does not mention the operation at the time of demolding. Furthermore, in the laminated molded product disclosed in Patent Document 4, the CFRP physical properties are not sufficiently expressed unless a cooling press process is performed after hot press processing in a mold, resulting in an increase in the number of man-hours and a takt time. There is the problem of lengthening.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for manufacturing a laminated molded body that can reduce costs by shortening the tact time and improving the production efficiency without lowering the mechanical properties.

As a result of intensive research, the inventors have found a method for producing a laminated molded product having good mechanical properties even if the mold is demolded without cooling the mold.
That is, the method for producing a laminated molded body according to the first aspect of the present invention is laminated molding having a structure in which a metal member, an interlayer adhesive layer containing a phenoxy resin, and a fiber reinforced resin layer are laminated and integrated. It is a method of manufacturing a body. The method for manufacturing a laminated molded body according to the first aspect of the present invention includes the following steps (1) to (4);
Step (1): A step of setting a metal member, an interlayer adhesive, and a fiber reinforced resin material in a pressing device in which the mold temperature is kept within the range of 160 to 240°C.
Step (2): The mold is closed, and the metal member and the fiber reinforced resin material are laminated and integrated by hot press molding to form a composite, and at the same time, shaping is performed.
Step (3): A step of demolding the integrated laminated molded body at a temperature within −10° C. from the mold temperature of the step (1) and removing it from the press device;
Step (4): a step of adjusting the mold temperature to the temperature of step (1);
as one cycle.
In the method for producing a laminated molded body according to the first aspect of the present invention, the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin, and steps (1) to (4) are ) is less than 10 minutes.

In the method for manufacturing a laminated molded body according to the first aspect of the present invention, the mold has a fixed mold and a movable mold, and the set temperature of the fixed mold in step (1) is lower than the set temperature of the movable mold. A temperature higher than 10° C. may be set.

In the method for producing a laminated molded body according to the first aspect of the present invention, in step (1), a metal member, an interlayer adhesive, and a fiber-reinforced resin material are laminated in this order, and the metal member is set so as to be in contact with a fixed mold. You may

In the first aspect of the present invention, there is provided a method for producing a laminated molded article, wherein the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin and having thermal crosslinkability at a temperature of 160° C. or higher. may

In the method for producing a laminated molded article according to the first aspect of the present invention, the interlayer adhesive may be a resin composition containing a phenoxy resin and a thermoplastic elastomer.

In the method for manufacturing a laminated compact according to the first aspect of the present invention, the metal member is one or more selected from steel materials, iron-based alloys, aluminum, aluminum alloys, magnesium, and magnesium alloys having a thickness of 0.2 mm or more. good too.

A laminated molded article according to a second aspect of the present invention is a laminated molded article manufactured by any of the above methods,
An interlayer adhesive layer having a thickness of 10 μm or more is provided between the surface of the metal member and the fiber reinforced resin layer.

A method for manufacturing a laminated molded body according to a third aspect of the present invention is a method for manufacturing a laminated molded body having a structure in which a plurality of fiber-reinforced resin layers are laminated and integrated. The method for producing a laminated molded product according to the third aspect of the present invention includes the following steps (1) to (4);
Step (1): A step of laminating and setting a plurality of layers of fiber reinforced resin material in a press device whose mold temperature is kept within the range of 160 to 240 ° C.
Step (2): A step of closing the mold and simultaneously laminating and integrating multiple layers of the fiber reinforced resin material by hot press molding,
Step (3): A step of demolding the laminated molded body laminated and integrated at a mold temperature within −10° C. from the mold temperature of the step (1) and removing it from the press device;
Step (4): a step of adjusting the mold temperature to the temperature of step (1);
as one cycle.
In the method for producing a laminated molded body according to the third aspect of the present invention, the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin, and steps (1) to (4) are ) is less than 10 minutes.

A third aspect of the present invention is a method for manufacturing a laminate molded body, wherein the mold has a fixed mold and a movable mold, and the set temperature of the fixed mold in step (1) is lower than the set temperature of the movable mold. A temperature higher than 10° C. may be set.

In the method for manufacturing a laminated molded product according to the third aspect of the present invention, the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin and having thermal crosslinkability at a temperature of 160° C. or higher. There may be.

According to the method of the present invention, it is possible to shorten the tact time and manufacture a laminated molded product in a high cycle by appropriately blending resin, appropriate press molding operation, and appropriate press temperature. Furthermore, according to the method of the present invention, the amount of warpage of the laminated molded body can also be reduced.

1 is a drawing showing an example of the cross-sectional structure of a metal-FRP composite obtained by the method of the present invention. 4 is a drawing showing another example of the cross-sectional structure of the metal-FRP composite obtained by the method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which shows an example of the cross-sectional structure of the FRP laminated body obtained by the method of this invention. It is a timing chart showing changes in mold temperature and pressure in the method of the present invention. It is a timing chart showing changes in mold temperature and pressure in the conventional method. 1 is a drawing for explaining a method for measuring the warp of a metal-FRP composite and calculating the radius of curvature.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. It should be noted that the present invention is not limited to the following embodiments, and can be appropriately modified in design within the scope well known to those skilled in the art.

[Structure of laminate]
First, the structure of the laminate molded body produced by the method of the present invention will be described with reference to FIGS. 1 to 3. FIG.

Metal-FRP composite:
FIG. 1 is a schematic drawing showing the cross-sectional structure of a metal-FRP composite, which is an example of a laminated molded article produced by the method of the present invention. As shown in FIG. 1, the metal-FRP composite 100 includes a metal member 101, an FRP layer 102 as a fiber reinforced resin layer, and an interlayer adhesive layer 103 interposed between the metal member 101 and the FRP layer 102. , is equipped with In the metal-FRP composite 100, the FRP layer 102 has, although not shown, a matrix resin and composite reinforcing fibers contained in the matrix resin. The interlayer adhesive layer 103 is provided in contact with at least one surface of the metal member 101 and firmly bonds the metal member 101 and the FRP layer 102 together. Note that the interlayer adhesive layer 103 and the FRP layer 102 may be formed on both sides of the metal member 101, respectively. Moreover, the metal members 101 may be arranged on both sides so as to sandwich the laminate including the interlayer adhesive layer 103 and the FRP layer 102 .

In the metal-FRP composite 100, the FRP layer 102 is formed using at least one prepreg for FRP molding. The FRP layer 102 is not limited to one layer, and may have two or more layers as shown in FIG. 2, for example. The thickness of the FRP layer 102 and the number of layers of the FRP layer 102 when the FRP layer 102 is a plurality of layers (represented by n in the figure) can be appropriately set according to the purpose of use. Each layer of the FRP layer 102 may have the same configuration or may have different configurations. That is, the resin type of the matrix resin constituting the FRP layer 102, the type and content ratio of the reinforcing fibers, and the like may differ from layer to layer.
When the FRP layer 102 is combined with the metal member 101, pre-molded FRP or preform can be used in addition to the prepreg for FRP molding. It is preferable that it is a preform from the viewpoint of.

In the metal-FRP composite 100, the resin constituting the interlayer adhesive layer 103 and the matrix resin of the first FRP layer 102 in contact with the interlayer adhesive layer 103 are the interlayer adhesive layer 103 and the first FRP layer. From the viewpoint of securing the adhesiveness with 102, it is preferable to select the same or the same type of resin or a resin species having a similar ratio of polar groups contained in the polymer. Here, the “same resin” means that it is composed of the same components and has the same composition ratio, and the “same kind of resin” means that if the main component is the same, the composition ratio is different. means good. "The same kind of resin" includes "the same resin." Moreover, the "main component" means a component contained in 50 parts by weight or more in 100 parts by weight of the resin component. The "resin component" includes thermoplastic resins and thermosetting resins, but does not include non-resin components such as cross-linking agents.

In the metal-FRP composite 100, the thickness of the interlayer adhesive layer 103 is preferably, for example, 10 μm or more from the viewpoint of ensuring sufficient adhesion between the metal member 101 and the FRP layer 102, and is preferably in the range of 10 to 100 μm. more preferred. If the thickness of the interlayer adhesive layer 103 is less than 10 μm, the adhesion between the metal member 101 and the FRP layer 102 is insufficient, and sufficient mechanical strength cannot be obtained in the metal-FRP composite 100 . On the other hand, if the thickness of the interlayer adhesive layer 103 exceeds 100 μm, the ratio of the interlayer adhesive layer 103 to the thickness becomes excessive, so that the metal-FRP composite 100 cannot obtain a sufficient reinforcing effect due to the reinforcing fibers. .

FRP laminate:
FIG. 3 is a schematic drawing showing the cross-sectional structure of an FRP laminate, which is another example of the laminated molded article produced by the method of the present invention. As shown in FIG. 3, the FRP laminate 200 includes a plurality of FRP layers 102 as fiber reinforced resin layers. In the FRP laminate 200, the FRP layer 102 has, although not shown, a matrix resin and composite reinforcing fibers contained in the matrix resin.

In the FRP laminate 200, the FRP layer 102 is formed using at least two prepregs for FRP molding. The thickness and the number of layers n of the FRP layer 102 can be appropriately set according to the purpose of use. Each layer of the FRP layer 102 may have the same configuration or may have different configurations. That is, the resin type of the matrix resin constituting the FRP layer 102, the type and content ratio of the reinforcing fibers, and the like may differ from layer to layer.

[Individual constituent elements of laminated molded body]
Each component of the metal-FRP composite 100 shown in FIGS. 1 and 2 and the FRP laminate 200 shown in FIG. 3 will be described.

<Metal member>
The material, shape, thickness, and the like of the metal member 101 in the metal-FRP composite 100 are not particularly limited as long as they can be molded by pressing or the like. The thickness of the metal member 101 is preferably 0.2 mm or more, and more preferably within the range of 0.2 to 3.0 mm. As the material of the metal member 101, for example, iron, titanium, aluminum, magnesium and alloys thereof are preferable. Here, the alloy means, for example, an iron-based alloy (including stainless steel), a Ti-based alloy, an Al-based alloy, a Mg alloy, and the like. More preferable examples of the material of the metal member 101 are steel materials, iron-based alloys, aluminum, aluminum alloys, magnesium, and magnesium alloys, and steel materials are most preferable. Examples of such steel materials include steel materials standardized by Japanese Industrial Standards (JIS), carbon steels, alloy steels, and high-tensile steels used for general structures and machine structures. can. Specific examples of such steel materials include cold-rolled steel, hot-rolled steel, hot-rolled steel for automobile structures, and hot-rolled high-strength steel for automobile processing.

<Interlayer adhesive>
The inter-layer adhesive used in the present invention is an adhesive material interposed between the metal member 101 and the FRP 102 to form an inter-layer adhesive layer 103 to more firmly bond the two. The interlayer adhesive is preferably a thermoplastic resin composition containing a phenoxy resin, more preferably a resin composition containing a phenoxy resin and a thermoplastic elastomer. Since the phenoxy resin used in the interlayer adhesive is the same as the phenoxy resin (described later) used in the matrix resin of the fiber-reinforced resin layer, the details will be described in the description of the matrix resin.

A thermoplastic elastomer that is preferably used as an interlayer adhesive together with a phenoxy resin means a thermoplastic resin containing hard segments (crystalline phase) and soft segments (amorphous phase) as constitutional units. By having a soft segment exhibiting rubber elasticity, it is possible to improve the tensile elongation at break of the interlayer adhesive layer 103 and, in particular, to increase the adhesive strength against peeling. Moreover, the heat resistance of the interlayer adhesive layer 103 can be enhanced by having a hard segment that becomes a crystal phase due to the pseudo-crosslinking structure. Examples of thermoplastic elastomers include olefin-based (TPV), polyurethane-based (TPU), polyester-based (TPEE), polyamide-based (PEBA), acrylic-based, and styrene-based. Among them, a polyester elastomer (polyester elastomer, TPEE) is preferable.

The polyester-based elastomer preferably has a tensile elongation at break of 200% or more, more preferably 300% or more. If the tensile elongation at break is less than 200%, the adhesive strength of the interlayer adhesive layer 103, especially the adhesive strength against peeling, will be low. The tensile elongation at break of the polyester-based elastomer in the present invention refers to the value measured according to JIS K7161.

The polyester elastomer preferably has a melting point of 180° C. or higher, more preferably 200° C. or higher. If the melting point is lower than 180° C., the interlayer adhesive layer 103 has a lower melting point and lower heat resistance. The melting point of the polyester-based elastomer in the present invention refers to a value measured by a differential scanning calorimeter (DSC).

The polyester-based elastomer is not particularly limited, and commercially available products can also be used. Commercially available products include, for example, Pelprene (trade name, manufactured by Toyobo Co., Ltd.), Hytrel (trade name, manufactured by Toray DuPont), Tefablock (trade name, manufactured by Mitsubishi Chemical Corporation), and Esteral (trade name, manufactured by Aron Kasei Co., Ltd.). and the like, and these can be used alone or in combination of two or more.

An optional component may be further included as a component constituting the interlayer adhesive. Preferred optional components include, for example, polyvinyl chloride, polystyrene, ABS resin, acrylic resin, polyethylene, polypropylene, polycarbonate, polyphenylene ether, polyamides such as nylon 6 and nylon 610, polyacetal, polyesters such as polyethylene terephthalate and polybutylene terephthalate, Thermoplastic resins such as polyphenylsulfone, polysulfone, polyarylate, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyamideimide and polyimide can be used. The interlayer adhesive layer 103 may further contain optional components such as flame retardants, inorganic fillers, colorants, antioxidants, UV inhibitors, plasticizers, cross-linking agents, and colorants, depending on the purpose. At this time, the total weight ratio of the phenoxy resin and the thermoplastic elastomer to the total weight of the resin components in the interlayer adhesive is desirably 70% or more, and more desirably 90% or more. When the total weight ratio of the phenoxy resin and the thermoplastic elastomer is less than 70%, it becomes difficult to develop the desired properties.
Also, the total weight ratio of the phenoxy resin and the thermoplastic elastomer to the total weight of the solid content in the interlayer adhesive is desirably 70% or more, more desirably 90% or more. When the total weight ratio of the phenoxy resin and the thermoplastic elastomer is less than 70%, it becomes difficult to develop the desired properties.

An interlayer adhesive can be prepared by mixing, for example, a phenoxy resin, a thermoplastic elastomer, and optionally optional ingredients. The method of mixing the phenoxy resin, thermoplastic elastomer and other components is not particularly limited, and generally known methods can be used. For example, each component is dissolved in a solvent to form a varnish, and blended using a stirring/mixing machine such as a propeller mixer or a rotation-revolution defoaming stirrer, or a kneader or extruder is used to melt and knead each component. methods and the like. Among these methods, melt-kneading is preferable as a method for uniformly mixing each component, and melt-kneading using a twin-screw extruder is most preferable.

The weight ratio of the phenoxy resin to the thermoplastic elastomer in the interlayer adhesive is preferably within the range of 10:90 to 60:40, more preferably within the range of 10:90 to 50:50. If the weight ratio of the phenoxy resin is less than 10%, the adhesive strength may decrease. If the weight ratio of the phenoxy resin exceeds 60%, the heat resistance may deteriorate.

Further, the tensile elongation at break of the interlayer adhesive is preferably 10% or more, more preferably 100% or more. If the tensile elongation at break is less than 10%, the adhesive strength especially against delamination will be low. The tensile elongation at break of the interlayer adhesive in the present invention refers to the value measured according to JIS K7161.

Further, it is desirable that the interlayer adhesive does not have a glass transition temperature in the range of 25-180°C. This indicates that the interlayer adhesive does not have a drastic change (decrease=softening) in storage modulus in the range of 25-180° C., and the change in adhesion is small. That is, it indicates that the heat resistance is high. The melting point of the interlayer adhesive is a numerical value obtained from the peak value of the second scan measured in the range of 0 to 280° C. using a differential scanning calorimeter (DSC).

<Fiber reinforced resin>
The fiber-reinforced resin that forms the FRP layer 102 of the metal-FRP composite 100 contains a matrix resin and reinforcing fibers.

The fiber-reinforced resin preferably has a storage modulus (E′ ₂₀₀ ) of 20 MPa or more at 200° C. in order to release the mold and release the material without cooling the mold during press molding. , more preferably 50 MPa or more. If E' ₂₀₀ is less than 20 MPa, springback occurs when the mold is opened, voids are generated inside the laminated molded product, and the quality of the obtained molded product is deteriorated, which is not preferable.

Moreover, it is preferable that the fiber reinforced resin has a deflection temperature under load of 200° C. or more. If the deflection temperature under load is lower than 200°C, the laminated molded product may be deformed when it is removed from the mold, which is not preferable.

<Reinforcing fiber>
The reinforcing fiber used in the FRP layer 102 of the metal-FRP composite 100 is not particularly limited, but carbon fiber, boron fiber, silicon carbide fiber, glass fiber, aramid fiber, etc. are preferable, and carbon fiber is more preferable. preferable. Regarding the types of carbon fibers, for example, both PAN-based and pitch-based carbon fibers can be used, and these may be used alone or in combination depending on the purpose and application.

Reinforcing fibers are used in any form such as unidirectional material, cloth such as plain weave or twill weave, three-dimensional cloth, chopped strand mat, or nonwoven fabric. is preferred.

<Matrix resin>
The matrix resin is composed of a phenoxy resin as an essential component. The matrix resin is a solventless resin composition containing a phenoxy resin, an epoxy resin and a cross-linking agent, and having thermal cross-linking reactivity at a temperature of 160° C. or higher (hereinafter sometimes referred to as a “matrix resin composition”). ) is preferably a crosslinked cured product. In addition, the matrix resin composition is in a state where reactivity is maintained in the prepreg or preform state, and in the state of FRP, it is a cross-linked cured product due to a cross-linking reaction.

The matrix resin composition is solid at room temperature, and its minimum melt viscosity at 160° C. or higher is 2000 Pa·s or less. The minimum melt viscosity at 160° C. or higher is preferably 1950 Pa·s or less, more preferably 1900 Pa·s or less. If the minimum melt viscosity at 160° C. or higher exceeds 2000 Pa·s, impregnation of the reinforcing fiber base material with the matrix resin composition becomes insufficient during molding by hot pressing, causing defects such as internal voids, and reducing the mechanical properties of the FRP. do.

In addition, the matrix resin exhibits a Tg of 160°C or higher because the heat resistance of the matrix resin is greatly increased compared to before molding due to a cross-linking reaction using the secondary hydroxyl group of the phenoxy resin, and a high load of 200°C or higher as a fiber reinforced resin. It is characterized by obtaining a molded article exhibiting a deflection temperature. In hot press molding using a mold, cooling operation is necessary to remove the molded product from the mold, but this cooling operation and reheating operation cause the molding tact time to be long, so we will shorten it. You have to put a lot of energy into it. Therefore, by using a matrix resin composition whose cured product Tg is 160° C. or higher and whose deflection temperature under load as a fiber reinforced resin is higher than the mold temperature at which hot press molding is possible. It can be released from the mold at a temperature within -10°C from the mold temperature during hot press molding, enabling high cycle molding. If the deflection temperature under load is lower than the mold temperature at which hot press molding is possible, there is a risk of deformation during demolding. will decline.

Each component of the matrix resin composition will be described below.

<Phenoxy resin>
The phenoxy resin used as an essential component in the matrix resin composition is preferably solid at room temperature and has a melt viscosity of 10000 Pa·s or less at 160°C. The melt viscosity of the phenoxy resin at 160° C. is preferably 100 to 3000 Pa·s, more preferably 200 to 1000 Pa·s. If the melt viscosity exceeds 10,000 Pa·s, the fluidity of the resin due to heat during molding processing is poor, so that the resin does not spread sufficiently in the reinforcing fiber base material, causing voids, and the mechanical properties of the laminated molded product are deteriorated. put away.

A phenoxy resin is a thermoplastic resin obtained from a condensation reaction of a dihydric phenol compound and epihalohydrin, or a polyaddition reaction of a dihydric phenol compound and a bifunctional epoxy resin, and is prepared by a conventionally known method in a solution or without a solvent. can be obtained with The average molecular weight of the phenoxy resin is usually 10,000 to 200,000, preferably 20,000 to 100,000, more preferably 30,000 to 80,000, as a weight average molecular weight (Mw). is. If the Mw is too low, the strength of the laminated molded product will be poor, and if it is too high, the workability and processability will tend to be poor. Mw is measured by gel permeation chromatography and converted using a standard polystyrene calibration curve.

The hydroxyl group equivalent weight (g/eq) of the phenoxy resin is usually 50-1000, preferably 100-750, particularly preferably 200-500. If the hydroxyl equivalent is too low, the number of hydroxyl groups increases and the water absorption rate increases, which is not preferable because there is a concern that the mechanical properties may deteriorate.

The glass transition point (Tg) of the phenoxy resin is suitably 65°C to 100°C or less, preferably 70°C to 100°C, more preferably 80°C to 100°C. If the glass transition point is lower than 65° C., the moldability is improved, but problems arise in the storage stability of the powder and the tackiness of the preform. If the temperature is higher than 100°C, the melt viscosity becomes high, resulting in poor moldability and fiber filling properties, and as a result, higher temperature press molding is required. The glass transition temperature of the phenoxy resin was measured in the range of 20 to 280° C. with a temperature rising condition of 10° C./min using a differential scanning calorimeter (DSC), and was calculated from the peak value of the second scan. Numeric value.

The phenoxy resin is not particularly limited as long as it satisfies the above physical properties. These can be used alone or in combination of two or more.

<Epoxy resin>
The epoxy resin is preferably a bifunctional or higher epoxy resin, more preferably a crystalline epoxy resin that is solid at room temperature, has a melting point of 60° C. to 145° C., and a viscosity of 1.0 Pa·s or less at 160° C. is good. If the viscosity at 160° C. exceeds 1.0 Pa·s, the filling property of the matrix resin composition into the reinforcing fiber base material is deteriorated, and the homogeneity of the obtained laminated molded product is deteriorated, which is not preferable.

<Crosslinking agent>
The cross-linking agent used in the present invention can be one having two or more functional groups that react with the OH groups of the phenoxy resin, but is preferably a compound having a dicarboxylic anhydride group (hereinafter simply referred to as an acid anhydride). be.
The acid anhydride as a cross-linking agent three-dimensionally cross-links the phenoxy resin by forming an ester bond with the secondary hydroxyl group of the phenoxy resin. , is understood to have two of the above functional groups with one anhydride group. Since dicarboxylic dianhydrides produce four functional groups, they have more cross-linking points than monocarboxylic anhydrides and can improve the cross-linking density, so they are preferably used.

The acid anhydride as a cross-linking agent is not particularly limited as long as it is solid at room temperature and does not sublimate, but pyromellitic anhydride, which is an acid anhydride having an aromatic ring, and ethylene glycol bis Anhydro trimellitate (TMEG), 4,4'-oxydiphthalic anhydride (s-ODPA), 3,4'-oxydiphthalic anhydride (a-ODPA), bisphenol A type dianhydride (BisDA) Although they are preferably used, ODPA and BisDA are more preferable because of their compatibility with phenoxy resins and epoxy resins and their resistance to moisture absorption.
In particular, the timing of the start of the cross-linking reaction is important for realizing high-cycle molding, and the most preferable cross-linking agent is an aromatic acid dianhydride having a melting point of 150° C. to 240° C., preferably 180° C. to 230° C., Examples of such aromatic acid dianhydrides include 3,4′-oxydiphthalic anhydride (a-ODPA) and BisDA. In the case of an aromatic acid dianhydride with a melting point exceeding 240°C, the cross-linking agent does not melt at the hot press temperature, so the cross-linking reaction is slow, and the undissolved residue may become foreign matter and adversely affect the mechanical properties of FRP. I don't like it because there is

The matrix resin composition contains 5 to 85 parts by weight of epoxy resin per 100 parts by weight of phenoxy resin. The blending amount of the epoxy resin is preferably 9 to 83 parts by weight, more preferably 10 to 70 parts by weight. When the amount of the epoxy resin is more than 85 parts by weight, it takes time to harden the epoxy resin, making it difficult to obtain the strength required for demolding in a short period of time. If the amount of epoxy resin to be blended is less than 5 parts by weight, the effect of blending the epoxy resin cannot be obtained, and the crosslinked cured product of the matrix resin composition becomes difficult to develop a Tg of 160° C. or higher.

The amount of the cross-linking agent is usually in the range of 0.5 to 1.5 mol, preferably 0.7 to 1.3 mol, of the acid anhydride group per 1 mol of the secondary hydroxyl group of the phenoxy resin. A range of amounts, more preferably in the range of 0.9 to 1.2 moles. If the amount of the cross-linking agent is too small, the acid anhydride groups reactive with the secondary hydroxyl groups of the phenoxy resin will be insufficient, resulting in a low cross-linking density and poor rigidity. The acid anhydride groups become excessive and unreacted acid anhydride groups adversely affect curing properties and crosslink density.

Furthermore, when a curing accelerator is used in the matrix resin composition, its blending amount is 0.1 to 5 parts by weight per 100 parts by weight of the total amount of the phenoxy resin, epoxy resin and cross-linking agent. Other additives are appropriately adjusted and added within a range that does not impair the production of prepreg or the characteristics of FRP.

In addition, the matrix resin composition may contain flame retardants, other thermoplastic resin powders, various inorganic fillers, and constituents as long as it does not impair the good adhesion to the reinforcing fiber substrate and the physical properties of the FRP molded body after molding. Other additives such as pigments, colorants, antioxidants, and UV inhibitors may also be added.
The flame retardant is not particularly limited as long as it is solid at room temperature and does not sublimate, but it is preferable to use a non-halogen flame retardant from the environmental and health impacts. Examples include flame retardants, organic and inorganic phosphorus-based flame retardants such as ammonium phosphates and phosphate ester compounds, and nitrogen-containing flame retardants such as triazine compounds. The amount of the flame retardant to be blended is appropriately selected depending on the type of flame retardant and the desired degree of flame retardancy. It is preferable to mix it to such an extent that the adhesiveness of the matrix resin composition and the physical properties of the FRP are not impaired.

The configuration of the FRP layer 102 in the FRP laminate 200 shown in FIG. 3 is the same as that of the FRP layer 102 in the metal-FRP composite 100, so the description is omitted.

[Manufacturing method of laminate]
Next, a method for manufacturing a laminate molded body according to an embodiment of the present invention will be described by taking the metal-FRP composite 100 shown in FIGS. 1 and 2 and the FRP laminate 200 shown in FIG. 3 as examples. .

Production of metal-FRP composite:
The metal-FRP composite 100 illustrated in FIGS. 1 and 2 can be produced by carrying out the following steps (1) to (4). Here, the tact time from step (1) to step (4) is less than 10 minutes, preferably within the range of 1 to 6 minutes, more preferably within the range of 1 to 3 minutes.
In the present invention, "takt time" is defined as follows. The starting point is the time when the material is set in the mold in step (1), and after the demolding operation in step (3), the mold temperature is changed again in step (4) to hot press mold the next laminated material. The point in time when the temperature was adjusted to 1) was defined as the end point, and the time required for this section was defined as the tact time. For example, when mold clamping cooling is performed at the time of demolding, the mold temperature above and below the press machine has decreased after demolding. time is included in the takt time.

Step (1):
In step (1), the metal member 101, the interlayer adhesive that will form the interlayer adhesive layer 103, and the fiber reinforced resin material that will form the FRP layer 102 are set in a pressing device whose mold temperature is maintained within the range of 160 to 240°C. do.
If the mold temperature during hot press molding is less than 160°C, heat is taken away by the laminated material set in the mold, and the temperature of the mold temporarily drops from the starting temperature of the cross-linking reaction (approximately 160°C). Therefore, if the temperature exceeds 240° C., the fiber-reinforced resin material may undergo thermal deterioration or prematurely undergo a cross-linking reaction. The mold temperature for hot press molding is preferably within the range of 180.degree. C. to 240.degree. In addition, the "set temperature" of the mold for hot press molding should be within +10°C or within +5°C higher than the temperature at which hot press molding of the laminated material is possible. This is preferable from the viewpoint of shortening the control time and reducing the number of times of temperature control even if ultra-short-time molding is continuously performed.

When the mold has a lower mold on the fixed side and an upper mold on the movable side, the upper mold and the lower mold may have different set temperatures for hot press molding in step (1). . Which of the upper and lower molds should have a higher set temperature can be set arbitrarily depending on the configuration of the laminated material to be set. preferably. The set temperature difference between the lower mold and the upper mold is preferably 10°C or more, preferably 10°C to 20°C. By making a difference between the set temperatures of the upper and lower molds, the heat taken away by the laminated material can be compensated in advance, thereby reducing the possibility of molding defects, and also reducing the warpage of the metal-FRP composite 100, which is a laminated molded product. It can also be reduced, and there is also the effect of improving the quality of the molded product.
When the mold temperature and the set temperature are different between the upper mold and the lower mold, the "mold temperature" and the "set temperature of the mold" mean the lower temperature.

The order of lamination of the metal member 101, the interlayer adhesive, and the fiber-reinforced resin material, which are laminated materials, is not particularly limited as long as the interlayer adhesive is interposed between the metal member 101 and the fiber-reinforced resin material. However, it is preferable to have a structure of metal member 101/interlayer adhesive/fiber reinforced resin material in order from the lower mold side.
In addition, if necessary, a glass fiber or aramid fiber nonwoven fabric or a prepreg made by impregnating the nonwoven fabric with a resin may be inserted between the interlayer adhesive and the fiber-reinforced resin material for the purpose of providing anticorrosion or other functions. can. However, if the number of layers of the laminated material set in the mold is excessive, the heat of the mold will be lost and the temperature of the hot plate will decrease, and in addition, uneven heating will occur in the laminated molded product, resulting in molding defects. Therefore, it is preferable that the molded thickness is within about 5 mm, preferably within 4 mm.

The surface of the metal member 101 may be subjected to arbitrary surface treatment during lamination. Here, the surface treatment includes, for example, various plating treatments such as zinc plating and aluminum plating, chemical conversion treatments such as chromate treatment and non-chromate treatment, and chemical surface roughening such as physical or chemical etching such as sandblasting. Examples include, but are not limited to, treatments. In addition, multiple types of surface treatments may be applied.

The interlayer adhesive can be in various forms such as solid (pellet), powder, liquid, etc. From the viewpoint of handling, it is preferable to use it as an adhesive resin sheet in the form of a film. In this case, the film can be directly laminated with the metal member 101 and the fiber-reinforced resin material, or can be used in a state of being laminated on the surface of the metal member 101 . The method for forming the interlayer adhesive into a film is not particularly limited, and generally known methods can be used, such as melt extrusion molding, solution casting molding, and calender molding.

The adhesive resin sheet of the interlayer adhesive, for example, preferably has a thickness in the range of 5 to 500 micrometers, more preferably 5 to 250 micrometers, more preferably 10 to 100 micrometers. Most preferably it has a thickness in the meter range.

The fiber-reinforced resin material used in step (1) may be in any state of prepreg, preform, or FRP molded body.

<Prepreg>
When a fiber-reinforced resin material is used as a prepreg, the prepreg is preferably obtained by applying a matrix resin composition powder to a reinforcing fiber substrate by powder coating. Powder coating methods include a fluidized coating method using a fluidized bed and an electrostatic coating method using an electrostatic field, and both methods can be used in the present invention. An electrostatic coating method using an electrostatic field is preferable because of its uniformity.

When obtaining a prepreg by the powder coating method, each component constituting the matrix resin composition is pulverized using a pulverizer and mixer such as a low temperature dry pulverizer (centri dry mill). As for the size of the powder, the average particle size is preferably in the range of 10-100 μm, more preferably in the range of 40-100 μm, and most preferably in the range of 40-50 μm.
Also, the average particle size of the phenoxy resin powder and the epoxy resin powder in the matrix resin composition is preferably 1 to 1.5 times the average particle size of the cross-linking agent. By making the particle size of the cross-linking agent powder finer than that of each powder of the phenoxy resin and the epoxy resin, the cross-linking agent adheres even to the inside of the reinforcing fiber base material, and cross-linking occurs around the particles of the phenoxy resin and the epoxy resin. The presence of the agent evenly allows the cross-linking reaction to proceed reliably.

Regarding the amount of the matrix resin composition powder attached to the reinforcing fiber base material, the resin ratio (RC) is preferably in the range of 20 to 50%, more preferably in the range of 25% to 40%, and most preferably 25%. It is preferable to apply the content within the range of up to 30%. If the resin ratio (RC) exceeds 50%, the mechanical properties such as tensile and flexural modulus of FRP will be deteriorated, and if it is less than 20%, the amount of resin adhered will be extremely small, so it will not penetrate inside the base material. The impregnation of the matrix resin becomes insufficient, and both the thermophysical properties and the mechanical properties become poor, which is undesirable.

<FRP moldings/preforms>
By laminating a plurality of prepregs and applying heat and pressure, an FRP molded article or preform can be obtained. As long as preforming to FRP molded articles or preforms using prepreg is heat and pressure molding, various methods such as autoclave molding and hot press molding using a mold can be used according to the size and shape of the desired molded product. A molding method can be appropriately selected and implemented.
When the prepreg is used as an FRP molded body, the molding temperature is preferably in the range of 160 to 240°C, more preferably in the range of 160 to 220°C, and most preferably in the range of 180 to 200°C. The pressure is preferably within the range of 3-5 MPa. If the molding temperature exceeds the upper limit temperature of the above range, excessive heat will be applied and the cross-linking reaction will occur quickly. Since it is sufficient, it causes deterioration of the mechanical properties of FRP.

The prepreg used to manufacture the metal-FRP composite 100 can quickly develop mechanical strength at high temperatures through a cross-linking reaction. For this reason, the contact time of the hot plate and the mold of the hot press machine can be very short, less than 10 minutes, and the hot plate and the mold can be demolded without cooling. is possible.

On the other hand, when a prepreg is used as a preform, it is hot-pressed at a temperature of 90 to 200° C., preferably 160 to 200° C., and a pressure of 1 to 5 MPa for a short time of 10 seconds to 2 minutes to form a flat plate. Molding is recommended.
By hot-pressing the prepreg at a temperature lower than the temperature at which the cross-linking reaction starts, the state in which the cross-linking reaction remains to the extent that the matrix resin composition can reflow, that is, a preform, and remolding at a temperature of 160 ° C. or higher. The cross-linking reaction can be completed and shaped.

The bonding surfaces of the fiber-reinforced resin material and the interlayer adhesive (adhesive resin sheet) are preferably roughened by blasting or the like, or activated by plasma treatment or corona treatment.

A specular plate or release sheet may be placed between the mold and the laminate material, if necessary. In particular, direct contact between the fiber-reinforced material and the mold causes adhesion of the resin, which hinders removal from the mold and causes deterioration of the appearance of the product surface during continuous production.
Further, it is also possible to arrange a pin or the like for preventing slippage outside the work area in order to prevent the product from slipping during hot pressing.

The laminate material is preferably preheated to 90 to 120° C. in a place other than the mold of the heat press. Preheating reduces the decrease in mold temperature when the mold is set in the hot press machine, so that molding quality can be improved. Preheating may be performed by a general atmospheric oven or a hot plate, but it is preferable to perform preheating in the vicinity of the heat press apparatus in order to suppress the temperature drop during movement as much as possible. Note that preheating at a temperature exceeding 160° C. is not suitable because the cross-linking reaction occurs prematurely.

Step (2):
In the step (2), the mold is closed, and the metal member 101 and the fiber-reinforced resin material are laminated and integrated with an interlayer adhesive by hot press molding, and shaping is performed at the same time.

<Conditions for thermocompression bonding>
The thermocompression bonding temperature for combining the metal member 101, the interlayer adhesive, and the fiber-reinforced resin material prepreg (or FRP molding or preform) is in the range of 160°C to 240°C, preferably 160°C. ~220°C, most preferably 190°C to 210°C. If the temperature exceeds the upper limit, the cross-linking reaction may proceed before the resin impregnates the fibers, resulting in poor impregnation. On the other hand, when the temperature is below the lower limit temperature, the melt viscosity of the resin becomes high, and the impregnation of the reinforcing fiber base material becomes poor. The "heating and pressurizing temperature" may be strictly different from the "set temperature" of the mold for hot press molding, but it is preferably within -5°C from the set temperature.

The pressure during crimping is preferably, for example, 3 MPa or more, more preferably within the range of 3 to 5 MPa. If the pressure exceeds the upper limit, deformation or damage may occur due to the application of excessive pressure.

The heating and pressurizing time varies depending on whether the fiber-reinforced resin material is a prepreg, a preform, or an FRP molded body. 5 minutes, more preferably 2 to 3 minutes is sufficient, and in the case of FRP molded products, it is possible to heat and press for at least 0.5 minutes, and 10 minutes at most. Less than, preferably in the range of 0.5 to 5 minutes, more preferably in the range of 0.5 to 2 minutes is sufficient.

Step (3):
Step (3) is a step of demolding the metal-FRP composite 100, which is a laminated molded body integrated at a temperature within −10° C. from the mold temperature of step (1), and removing it from the press. .

After step (2) is completed, the mold is usually cooled in a clamped state (mold clamping cooling), and the metal-FRP composite 100 is removed from the mold. is unnecessary. It should be noted that the temperature drop due to the heat of the mold being taken away by the molded product during the molding process is not regarded as mold clamping cooling.

In the present invention, the mold temperature at the time of demolding (sometimes simply referred to as “demolding temperature”) is −10° C. from the mold temperature for hot press molding [that is, the mold temperature in step (1)]. within, preferably within −5° C., most preferably at the mold temperature of step (1). Here, “within the mold temperature of −10° C. in step (1)” means that forced cooling such as mold clamping cooling is not performed. By not performing mold clamping cooling, the time required for mold clamping cooling and the time required to reheat the mold in the next step (4) to return to the mold temperature in step (1) can be saved. The takt time can be greatly reduced because it is possible to mold and process the product. Thus, the method of the present invention is characterized in that the time required for step (3) can be significantly reduced, and from this point of view, the time required for step (3) is 20% or less of the tact time, preferably 5 to 5. It can be in the range of 15%, more preferably in the range of 5-10%.

Step (4):
Step (4) is a step of adjusting the mold temperature to the mold temperature of step (1), and when the demolding temperature in step (3) is lower than the mold temperature of step (1), The mold temperature is increased to that of step (1). If the demolding temperature in step (3) does not decrease and is maintained at the mold temperature in step (1), step (3) and step (4) will proceed simultaneously. ) can be regarded as the end point of step (4).
In this way, the method of the present invention is characterized in that in addition to the reduction in the time required for step (3), the time required for step (4) can be significantly reduced. From this point of view, the time required for step (4) is , 30 seconds or less, for example, 15% or less of the tact time, preferably in the range of 0 to 5%. If there is no next cycle, the end point of step (4) can be regarded as the end point of step (3) in the last cycle.

<Optional process>
The metal-FRP composite 100, which is a molded product after demolding, may be subjected to natural cooling or forced cooling by blowing air, for example, gentle cooling in an environment of about 40°C.

In addition, the metal-FRP composite 100 after thermocompression bonding exhibits sufficient mechanical strength as it is. Post-curing is preferably performed at a temperature within the range of 240° C. for about 5 to 60 minutes. The quality (strength, heat resistance) is further stabilized by completing the cross-linking reaction by post-curing. In addition, it is also possible to utilize the heat history in a post-process such as painting as a post-cure.

<Post-processing>
In the post-process for the metal-FRP composite 100, in addition to painting, holes are drilled for mechanical bonding with other members such as bolts and riveting, and adhesive is applied for adhesive bonding. Assembly takes place.

Production of FRP laminate:
The FRP laminate 200 illustrated in FIG. 3 can be manufactured by carrying out the following steps (1) to (4). Here, the tact time from step (1) to step (4) is less than 10 minutes, preferably within the range of 1 to 6 minutes, more preferably within the range of 1 to 3 minutes. The meaning of the tact time is the same as in the case of manufacturing the metal-FRP composite 100.

Step (1):
In step (1), a plurality of layers of fiber-reinforced resin material that will form the plurality of FRP layers 102 are set in a pressing device whose mold temperature is maintained within the range of 160 to 240°C.
If the mold temperature during hot press molding is less than 160°C, heat is taken away by the laminated material set in the mold, and the temperature of the mold temporarily drops from the starting temperature of the cross-linking reaction (approximately 160°C). Therefore, if the temperature exceeds 240° C., the fiber-reinforced resin material may undergo thermal deterioration or prematurely undergo a cross-linking reaction. The mold temperature for hot press molding is preferably within the range of 180.degree. C. to 240.degree. In addition, the "set temperature" of the mold for hot press molding should be within +10°C or within +5°C higher than the temperature at which hot press molding of the laminated material is possible. This is preferable from the viewpoint of shortening the control time and reducing the number of times of temperature control even if ultra-short-time molding is continuously performed.

When the mold has a lower mold on the fixed side and an upper mold on the movable side, the upper mold and the lower mold may have different set temperatures for hot press molding in step (1). . Which of the upper and lower molds should have a higher set temperature can be set arbitrarily depending on the configuration of the laminated material to be set. preferably. The set temperature difference between the lower mold and the upper mold is preferably 10°C or more, preferably 10°C to 20°C. By making a difference between the set temperatures of the upper and lower molds, the heat taken away by the laminated material can be compensated in advance, thereby reducing the possibility of molding defects, and also reducing the warpage of the FRP laminate 200, which is a laminated molded product. It also has the effect of improving the quality of the molded product.

Between the multiple layers of the fiber reinforced resin material that is the laminated material, if necessary, an adhesive film, a nonwoven fabric of glass fiber or aramid fiber for the purpose of imparting functions, a prepreg made by impregnating the nonwoven fabric with a resin, etc. can also be inserted. However, if the number of layers of the laminated material set in the mold is excessive, the heat of the mold will be lost and the temperature of the hot plate will drop, and the laminated material will be unevenly heated, resulting in molding defects. Therefore, the molding thickness should be within 5 mm, preferably within 4 mm.

The fiber-reinforced resin material used in step (1) may be in either a prepreg or preform state. Since the prepreg and preform are the same as those described in the manufacturing of the metal-FRP composite 100, description thereof is omitted.

A specular plate or release sheet may be placed between the mold and the laminate material, if necessary. In particular, direct contact between the fiber-reinforced material and the mold causes adhesion of the resin, which hinders removal from the mold and causes deterioration of the appearance of the product surface during continuous production.
Further, it is also possible to arrange a pin or the like for preventing slippage outside the work area in order to prevent the product from slipping during hot pressing.

The laminate material is preferably preheated to 90 to 120° C. in a place other than the mold of the heat press. Preheating reduces the decrease in mold temperature when the mold is set in the hot press machine, so that molding quality can be improved. Preheating may be performed by a general atmospheric oven or a hot plate, but it is preferable to perform preheating in the vicinity of the heat press apparatus in order to suppress the temperature drop during movement as much as possible. Note that preheating at a temperature exceeding 160° C. is not suitable because the cross-linking reaction occurs prematurely.

Step (2):
In step (2), the mold is closed, and a plurality of layers of the fiber-reinforced resin material are laminated and integrated by hot press molding, and shaping is performed at the same time.

<Conditions for thermocompression bonding>
The thermocompression bonding temperature for compositing the prepreg (or preform) to be the fiber-reinforced resin material is in the range of 160°C to 240°C, preferably 160°C to 220°C, most preferably 190°C to 210°C. inside is good. If the temperature exceeds the upper limit, the cross-linking reaction may proceed before the resin impregnates the fibers, resulting in poor impregnation. On the other hand, when the temperature is below the lower limit temperature, the melt viscosity of the resin becomes high, and the impregnation of the reinforcing fiber base material becomes poor. The "heating and pressurizing temperature" may be strictly different from the "set temperature" of the mold for hot press molding, but it is preferably within -5°C from the set temperature.

The pressure during crimping is preferably, for example, 3 MPa or more, more preferably within the range of 3 to 5 MPa. If the pressure exceeds the upper limit, deformation or damage may occur due to the application of excessive pressure.

The heat and pressure treatment time varies depending on whether prepreg or preform is used as the fiber reinforced resin material. Any time within the range, more preferably between 2 and 3 minutes, is sufficient.

Step (3):
Step (3) is a step of demolding the FRP laminate 200, which is a laminate molded body laminated and integrated at a temperature within −10° C. from the mold temperature of step (1), and removing it from the press machine.

After step (2) is completed, the mold is usually cooled while the mold is clamped, and the FRP laminate 200 is removed from the mold. It should be noted that the temperature drop due to the heat of the mold being taken away by the molded product during the molding process is not regarded as mold clamping cooling.

In the present invention, the demolding temperature is within −10° C., preferably within −5° C., most preferably within the step ( The mold temperature in 1) remains the same. Here, “within the mold temperature of −10° C. in step (1)” means that forced cooling such as mold clamping cooling is not performed. By not performing mold clamping cooling, the time required for mold clamping cooling and the time required to reheat the mold in the next step (4) to return to the mold temperature in step (1) can be saved. The takt time can be greatly reduced because it is possible to mold and process the product. Thus, the method of the present invention is characterized in that the time required for step (3) can be significantly reduced, and from this point of view, the time required for step (3) is 20% or less of the tact time, preferably 5 to 5. It can be in the range of 15%, more preferably in the range of 5-10%.

Step (4):
Step (4) is a step of adjusting the mold temperature to the mold temperature of step (1), and when the demolding temperature is lower than the mold temperature of step (1) in step (3), the step Raise the mold temperature to (1). If the demolding temperature in step (3) does not decrease and is maintained at the mold temperature in step (1), step (3) and step (4) will proceed simultaneously. ) can be regarded as the end point of step (4).
In this way, the method of the present invention is characterized in that in addition to the reduction in the time required for step (3), the time required for step (4) can be significantly reduced. From this point of view, the time required for step (4) is , 30 seconds or less, for example, 15% or less of the tact time, preferably in the range of 0 to 5%. If there is no next cycle, the end point of step (4) can be regarded as the end point of step (3) in the last cycle.

<Optional process>
As for the FRP laminate 200, which is a molded product after demolding, cooling, post-curing, post-processing, etc. can be carried out as in the manufacturing of the metal-FRP composite 100 as optional steps.

<Action>
Next, the operation of the method of the present invention will be described with reference to FIGS. 4 and 5. FIG.
FIG. 4 is a timing chart showing changes in mold temperature and pressure in steps (1) to (4) in the cycle molding of the method of the present invention in chronological order. The horizontal axis indicates the passage of time. T1 on the vertical axis represents the mold temperature at which the laminated material can be molded, and T2 represents the mold temperature at the time of demolding (demolding temperature). Also, P1 on the vertical axis means press pressure, and P2 means demolding pressure (normal pressure). Also, numbers (1), (2), (3), and (4) in the figure correspond to steps (1) to (4). The set temperature of the mold for hot-press molding the laminated material is preferably within T1+10°C or within +5°C.

As shown in FIG. 4, in the method of the present invention, first, the laminate material is set at t0 when the mold temperature is kept at T1. In other words, step (1) is performed at any time from t0 to t1. It should be noted that FIG. 4 does not show the decrease in mold temperature due to the heat being taken away by the laminated material (the same applies to FIG. 5).
Next, pressurization is started from t1 and the pressure is increased to P1. Strictly speaking, it takes a short time for the pressure to reach from P2 to P1 after the start of pressurization. is). At t2, the pressurization is released and the pressure is lowered to P2. Strictly speaking, it takes a little time for the pressure to drop from P1 to P2, but it is drawn at the same time in FIG. 4 (the same applies to FIG. 5) because it is instantaneous compared to other process times. The period from t1 to t2 above corresponds to the length of step (2). Note that, in FIG. 4, the sections in which the temperature T1 and the pressure P1 are maintained (for example, from t1 to t2, from t5 to t6, from t9 to t10) correspond to the heating and pressurizing processing time.
Next, the mold is demolded at t3. That is, step (3) is performed. At this time, the demolding temperature T2 is within T1-10° C. with reference to the mold temperature T1 in step (1) for hot press molding. FIG. 4 illustrates the case where the mold temperature is maintained at the same mold temperature T1 as in step (1) when demolding at t3 (that is, T1=T2). Therefore, the demolding time t3 can be substantially regarded as the end point t4 of step (4), and t3 and t4 are substantially simultaneous. That is, in the example shown in FIG. 4, step (3) and step (4) are actually performed simultaneously, and the mold temperature is adjusted to T1 at t3 at the time of demolding. Step (4) also ends at t3. Therefore, at t3 when the mold is demolded, preparation for setting the lamination material for the next cycle in the mold is completed, and t3 can be set as the start timing of step (1) in the next cycle. Therefore, in the example shown in FIG. 4, the tact time can be shortened.
Although not shown, if the demolding temperature drops below T1 at the demolding time t3, the mold temperature is adjusted after demolding and is raised to T1 until t4. In this case, the period from t3 to t4 corresponds to the length of step (4). (4) is performed in a very short time and has little effect on the takt time.

The period from t0 to t4 is the tact time in the first cycle. Here, at t4, the mold temperature has been adjusted to T1, and since the lamination material for the next cycle is ready to be set in the mold, step (1) in the next cycle is started. can be timing.

Therefore, the second lamination material can be set while the mold temperature is maintained at T1 from t4 to t5. Then, pressure is applied from t5 to t6, and after the pressure drops to P2, the mold is demolded at t7 and at the same time, the end point t8 of step (4) is reached. The above t4 to t8 is the tact time in the second cycle. Here, at t8, the mold temperature has been adjusted to T1, and since the lamination material for the next cycle is ready to be set in the mold, step (1) in the next cycle is started. can be timing.
Similarly, between t8 and t9, the third layered material is set while the mold temperature is kept at T1, pressurized from t9 to t10, and after the pressure drops to P2, the mold is demolded at t11. This is the end point t12 of step (4). The above t8 to t12 is the tact time in the third cycle. Here, at t12, the mold temperature has been adjusted to T1, and since the lamination material for the next cycle is ready to be set in the mold, step (1) in the next cycle is started. can be timing.
Thereafter, molding can be repeated in the same manner to continuously produce a laminated molded product.

As described above, it is understood that the method of the present invention does not require clamping cooling before demolding, so that the tact time is short. It should be noted that when the steps (1) to (4) are taken as one cycle and N cycles are continuously repeated, the step (4) is performed in preparation for the next cycle in the last N-th cycle. becomes unnecessary, it is important how the tact time can be shortened in the cycles up to the (N-1)th cycle.

On the other hand, FIG. 5 is a timing chart showing changes in mold temperature and pressure in cycle molding of the conventional method in chronological order. The horizontal axis is time, and T1, T2, P1, and P2 on the vertical axis are the same as in FIG.
As shown in FIG. 5, in the conventional method, first, the laminate material is set at t20 while the mold is held at temperature T1. In other words, the step (1) is performed at some time from t20 to t21.
Next, pressurization is started at t21 and the pressure is increased to P1. Then, the period from t21 to t22 in FIG. 5 corresponds to step (2) of the present invention, but in the conventional method, mold clamping cooling is performed from t22 to t23 while pressurization is continued thereafter. That is, from t22, the mold temperature is lowered to T2, which is the set temperature for mold clamping cooling, while the pressure P1 is being pressurized. Let it be P2. Then, the mold is demolded at t24, and after the demolding, the mold temperature is raised to T1 until t25. The above t20 to t25 is the tact time in the first cycle.
Similarly, after t25, the next layered material is set while the mold temperature is kept at T1, pressurized at t26, and clamping cooling is performed from t27 to t28 to lower the temperature of the mold to T2. Then, the pressurization is released, and the mold is removed at t29. The above t25 to t30 is the tact time in the second cycle.

Thereafter, molding can be repeated in the same manner, but in the conventional method, the step (3)' between t22 and t24 (between t27 and t29) includes mold clamping cooling, so the step (3 ) takes significantly more time. In addition, although the period from t24 to t25 (between t29 and t30) corresponds to the step (4) of the present invention, the time until the mold temperature is returned to T1 is compared to the step (4) of the present invention. will be needed for a long time. As described above, the conventional method requires a certain amount of time for mold clamping cooling and subsequent temperature recovery, which makes high-cycle molding difficult and hinders mass production on an industrial scale. On the other hand, the method of the present invention does not require mold clamping cooling before demolding, so the tact time is short, and molding can be repeated in a high cycle, so it is excellent in mass productivity and industrial scale. It is possible to continuously produce laminate molded bodies at

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the description of these examples. Various physical property tests and measurement methods in Examples and Comparative Examples are as follows.

[Average particle size ( _D50 )]
The average particle size was measured by a laser diffraction/scattering particle size distribution analyzer (Microtrac MT3300EX, manufactured by Nikkiso Co., Ltd.) when the cumulative volume reached 50% on a volume basis.

[Melt viscosity]
Using a rheometer (manufactured by Anton Paar), a sample with a sample size of 4.3 cm ³ was sandwiched between parallel plates and heated to 250°C at a rate of 20°C/min, under the conditions of frequency: 1Hz and load strain: 5%. The complex viscosity was measured as the melt viscosity.

[DMA analysis]
Using a single cantilever of DMA850 (manufactured by TA-Instrument Japan), a sample with a sample size (width 15 mm × length 30 mm × thickness 1 mm) was heated at a heating rate of 5 ° C./min, a strain of 0.1%, and a frequency of 1 Hz. The maximum peak of tan δ obtained by measurement was taken as the glass transition temperature.

[Resin ratio (RC:%)]
It was calculated using the following formula from the weight (W1) of the reinforcing fiber base material before adhesion of the matrix resin and the weight (W2) of the fiber reinforced resin material after adhesion of the resin.
Resin ratio (RC:%) = (W2-W1)/W2 x 100
W1: Weight of reinforcing fiber base material before adhesion of resin W2: Weight of fiber reinforced resin material after adhesion of resin

[Bending test]
In accordance with JIS K 7074:1988 bending test method for fiber reinforced plastics, mechanical properties (flexural strength and flexural modulus) of metal-FRP composite 100 and FRP laminate 200 were measured using a universal testing machine (A&D Co., Ltd.). (manufactured).
As shown in FIG. 1, the metal-FRP composite 100 was evaluated with a structure in which a laminate of the FRP layer 102 is bonded to one side of the metal member 101 via the interlayer adhesive layer 103. In the bending test, the load was applied in the direction from the metal member 101 side toward the laminate of the FRP layers 102 .

[Measurement of warpage]
The amount of warpage was measured using a metal-FRP composite sample for bending test with a universal testing machine (manufactured by A&D). As shown in FIGS. 6(a) and 6(b), the sample is set in a universal testing machine, the displacement difference in the case of upward convexity and the displacement difference in the case of downward convexity is 2×ΔZ, and ΔZ is the warpage. The average value of 5 samples was used as the amount.

[Curvature radius measurement]
The radius of curvature was obtained from the value of the amount of warp using the following formula.

In the formula, r is the radius of curvature and w is the chord. Here, as shown in FIG. 6(c), the following relationship is established among the amount of warp ΔZ, the radius of curvature r, and the chord w. Note that the radius of curvature r and the chord w are derived from the arc of a virtual circle centered at the midpoint in the thickness direction of the sample.
r ² = (r-ΔZ/2) ² + (w/2) ²
rΔZ=ΔZ ² /4+w ² /4

[Measurement of springback]
The ratio of the actual thickness (h1) of the molded body to the design thickness (h0) of the molded body was calculated as a springback from the following equation as a percentage of 100.
Springback (%) = [(h1/h0) x 100] - 100

[Deflection temperature under load]
JIS K 7191 (Plastics - Determination of deflection temperature under load) is used as a reference to measure the deflection temperature under load of the fiber reinforced resin used as the test piece. The case of ◯ (good), and the case of less than 200 ° C. was evaluated as × (improper).

[phenoxy resin]
Phenotote YP-50S (manufactured by Nippon Steel Chemical & Materials Co., Ltd., bisphenol A type, Mw; 40,000, hydroxyl equivalent; 284 g/eq), melt viscosity at 160 ° C.; 2310 Pa s, Tg; 83 ° C.)

[Epoxy resin]
YSLV-80XY (manufactured by Nippon Steel Chemical & Materials Co., Ltd., tetramethylbisphenol F type, epoxy equivalent: 192 g / eq, melting point = 72 ° C.)

[Crosslinking agent]
BISDA (manufactured by SHPP Japan LLC, bisphenol A-type acid dianhydride, acid anhydride equivalent: 254, melting point: 185°C)

[Polyamide resin]
CM1017 (manufactured by Toray Industries, melting point; 225 ° C., melt viscosity at 250 ° C.; 125 Pa s, Tg; 55 ° C.)

[Production example 1]
Preparation of prepreg (A):
A powder having an average particle diameter D ₅₀ of 80 μm obtained by pulverizing and classifying a phenoxy resin is applied to a carbon fiber cloth material (cloth material: SA-3202I manufactured by Sakai Ovex Co., Ltd.) as a base material. Powder coating was performed under the conditions of a spray air pressure of 0.32 MPa. After that, the resin is heat-fused in an oven at 170° C. for 1 minute to form a partially fused structure, and the phenoxy resin CFRP prepreg having a thickness of 0.25 mm and a resin ratio (RC) of 31% ( A) (hereinafter referred to as “prepreg (A)”) was produced.

Preparation of CFRP (A10):
A prepreg (A) with a size of 100 mm × 100 mm is used, 12 sheets of it are stacked, and a press machine heated to 240 ° C. is pressed at 5 MPa for 2 minutes. was molded from CFRP (A10) with a thickness of 0.9 mm.

[Production example 2]
Preparation of prepreg (B):
100 parts by weight of a phenoxy resin, 30 parts by weight of an epoxy resin, and 73 parts by weight of a cross-linking agent were prepared, pulverized and classified into powder having an average particle diameter _D50 of 80 μm, and dry-blended. The crosslinkable phenoxy resin composition thus obtained was subjected to static stretching using carbon fibers (IMS60, manufactured by Teijin Limited) that were opened and plain woven (cloth material: SA-3202I, manufactured by Sakai Ovex Co., Ltd.) as a reinforcing fiber base material. In an electric field, powder coating was performed under the conditions of a charge of 70 kV and a blowing air pressure of 0.32 MPa. After that, heat and melt in an oven at 140° C. for 10 seconds to heat-seal the resin to form a partially fused structure, a crosslinked phenoxy resin CFRP prepreg having a thickness of 0.25 mm and a resin ratio (RC) of 31% (B) (hereinafter referred to as "prepreg (B)") was produced.
The minimum melt viscosity of the crosslinkable phenoxy resin composition at a temperature of 160°C or higher was 308 Pa·s. Regarding the Tg of the phenoxy resin after cross-linking and curing, a plurality of prepared prepregs were laminated and pressed at 5 MPa for 10 minutes with a press heated to 200 ° C. to produce a CFRP laminate with a thickness of 1 mm, which was then cut with a diamond cutter. A test piece with a width of 15 mm and a length of 30 mm is cut out and measured using a dynamic viscoelasticity measuring device (DMA850 manufactured by TA-Instrument Japan) at a temperature increase of 5 ° C./min in the range of 30 to 200 ° C. , the maximum peak of tan δ obtained was taken as Tg.

Preparation of CFRP (B10):
Prepreg (B) with a size of 100 mm × 100 mm was used, and 12 sheets of it were stacked, and hot pressed at 5 MPa for 2 minutes with a press heated to 200 ° C. After cooling to 160 ° C. After demolding, CFRP (B10) having a thickness of 0.9 mm was molded.

Preparation of CFRP (B11):
The prepreg (B) having a size of 100 mm×100 mm was used, and 24 sheets of the prepreg (B) were stacked and hot-pressed at 5 MPa for 5 minutes with a press heated to 200°C. After clamping and cooling to 60° C., the mold was removed to form CFRP (B11) having a thickness of 1.8 mm.

[Production example 3]
Preparation of prepreg (C):
A powder having an average particle diameter D ₅₀ of 80 μm obtained by pulverizing and classifying a polyamide resin is used as a base material with a carbon fiber cloth material (cloth material: SA-3202I manufactured by Sakai Ovex Co., Ltd.) in an electrostatic field at an electric charge of 70 kV, Powder coating was performed under the conditions of a spray air pressure of 0.32 MPa. After that, heat and melt in an oven at 170 ° C. for 1 minute to thermally bond the resin to form a partially fused structure, which has a thickness of 0.15 mm, a carbon fiber content of 69% by weight, and a fiber volume content ( A polyamide resin CFRP prepreg (C) (hereinafter referred to as “prepreg (C)”) having a Vf) of 60% and a resin ratio (RC) of 31% was produced.

[Production of adhesive resin sheet]
Pellets of phenoxy resin having a bisphenol A skeleton (trade name: Phenotote YP50S, manufactured by Nippon Steel Chemical & Materials Co., Ltd.) and pellets of polyester elastomer (trade name: Hytrel BD406, manufactured by Toray DuPont Co., Ltd.) are electronically Using a balance, the mixture was weighed at a mass ratio of 33/67, and mixed using a rocking mixer (RM-10(S), manufactured by Aichi Electric Co., Ltd.) at 30 rpm rotation and 30 rpm rocking for 15 minutes. The mixed pellets are put into a hopper of a co-rotating twin-screw extruder with a screw diameter of 26 mm (TEM26SS manufactured by Toshiba Machine Co., Ltd., L/D about 50, cylinder set temperature 200 ° C., rotation speed 220 rpm), and a discharge amount of 12 kg. A resin composition was obtained by performing melt-kneading under the operation condition of /h. An adhesive resin sheet having a thickness of 0.05 mm was produced from the obtained resin composition using a 37t automatic press. Molding conditions: After pressing at 200° C. and 1 MPa for 3 minutes, degassing was performed three times.

[Metal member M]
SGCC (manufactured by Standard Testpiece Co., hot-dip galvanized steel sheet (SGCC), thickness: 0.4 mm)

[Examples 1 to 10, Comparative Examples 1 to 7]
A metal member M was used as the metal member 101, an adhesive resin sheet was used as the interlayer adhesive, and a prepreg or CFRP was used as the fiber-reinforced resin material in the laminated state shown in Tables 1 and 2.
These laminated materials are laminated in a layer structure of metal member M, adhesive resin sheet, and fiber reinforced resin material in order from the bottom, set in the lower mold, and pressed under the molding conditions shown in Tables 1 and 2. Pressing was performed to form a metal-FRP composite. Tables 1 and 2 also show the tact time of each example and comparative example. In Comparative Examples 1, 3, and 7, mold clamping cooling was performed during demolding, and in Examples 1 to 10 and Comparative Examples 2, 4, 5, and 6, mold clamping cooling was not performed during demolding.
Five specimens for bending test were cut out from the center of the metal-FRP composite obtained in each example and comparative example, and used as a metal-FRP composite sample for bending test. Tables 1 and 2 also show the springback measurement results, the warp amount measurement results, and the thermophysical properties of the matrix resin of the obtained samples.
Regarding the bending test results, the presence or absence of peeling between the laminate of the FRP layers 102 and the metal member 101 was confirmed, but in Comparative Example 4, only interfacial peeling of the metal member 101 was confirmed.

The effect of the method of the present invention was very clearly demonstrated in comparison between the example and comparative examples 2 to 5, in which only a non-crosslinkable thermoplastic resin was used as the FRP matrix resin composition. That is, with the phenoxy resin alone, it was difficult to suppress warpage and an increase in thickness called springback caused by the repulsive force of the reinforcing fibers, and with nylon, it was difficult to form a composite with a metal itself, whereas the method of the present invention is difficult. We were able to perform high-cycle molding without these problems. Further, as shown by comparison between Examples 1 and 6 and Comparative Examples 1 and 7, even when using the same fiber-reinforced resin material, the method of the present invention achieved a very short tact time of less than 10 minutes. It was possible to obtain a good metal-FRP composite with mechanical strength equivalent to that of conventional hot press molding and with suppressed warpage and springback.

[Examples 11 to 15, Comparative Examples 8 to 14]
A prepreg, which is a fiber-reinforced resin material, is set as a laminate material in a mold in the laminated state shown in Tables 3 and 4, and pressed with a press under the molding conditions shown in Tables 3 and 4 to form an FRP laminate. did. Tables 3 and 4 also show the tact time of each example and comparative example. In Comparative Examples 8 and 10, clamping cooling was performed during demolding, and in Examples 11 to 15 and Comparative Examples 9, 11, 12, 13, and 14, clamping cooling was not performed during demolding.
Five bending test specimens were cut out from the center of the FRP laminate obtained in each example and comparative example, and used as bending test FRP laminate samples. Tables 3 and 4 also show the springback measurement results and the warpage measurement results of the obtained samples.
In addition, interfacial peeling was not confirmed in any of the bending test results.

From Tables 3 and 4, according to the method of the present invention, as is clear from the comparison between Example 11 and Comparative Examples 9 and 11, large springback occurs and physical properties High cycle molding could be easily performed with a tact time of less than 10 minutes without causing deterioration. Furthermore, even if the same matrix resin is used, it is possible to perform high-cycle molding while maintaining the same or better quality of molded products than conventional molding methods, which will greatly improve the productivity of FRP laminates and reduce costs. can be done.

Although the embodiments of the present invention have been described above in detail for the purpose of illustration, the present invention is not limited to the above embodiments, and various modifications are possible.

DESCRIPTION OF SYMBOLS 100... Metal-FRP composite, 101... Metal member, 102... FRP layer, 103... Interlayer adhesive layer, 200... FRP laminate

Claims (10)

A method for manufacturing a laminated molded body having a structure in which a metal member, an interlayer adhesive layer containing a phenoxy resin, and a fiber reinforced resin layer are laminated and integrated,
the following steps (1) to (4);
Step (1): A step of setting a metal member, an interlayer adhesive, and a fiber reinforced resin material in a pressing device in which the mold temperature is kept within the range of 160 to 240°C.
Step (2): The mold is closed, and the metal member and the fiber reinforced resin material are laminated and integrated by hot press molding to form a composite, and at the same time, shaping is performed.
Step (3): A step of demolding the integrated laminated molded body at a temperature within −10° C. from the mold temperature of the step (1) and removing it from the press device;
Step (4): a step of adjusting the mold temperature to the temperature of step (1);
as one cycle,
Laminate molding characterized in that the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin, and the tact time from step (1) to step (4) is less than 10 minutes. body manufacturing method. Laminate molding according to claim 1, wherein the mold has a fixed mold and a movable mold, and the set temperature of the fixed mold in step (1) is set to a temperature 10°C or more higher than the set temperature of the movable mold. body manufacturing method. 3. The method for manufacturing a laminated molded product according to claim 1, wherein in step (1), the metal member, the interlayer adhesive, and the fiber-reinforced resin material are laminated in this order and set so that the metal member is in contact with the fixed mold. The laminate molded article according to any one of claims 1 to 3, wherein the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin and having thermal crosslinkability at a temperature of 160°C or higher. manufacturing method. 5. The method for producing a laminate molded article according to any one of claims 1 to 4, wherein the interlayer adhesive is a resin composition containing a phenoxy resin and a thermoplastic elastomer. The laminated compact according to any one of claims 1 to 5, wherein the metal member is one or more selected from steel materials, iron alloys, aluminum, aluminum alloys, magnesium, and magnesium alloys having a thickness of 0.2 mm or more. Production method. A laminate molded body produced by the method according to any one of claims 1 to 6,
A laminated molded article comprising an interlayer adhesive layer having a thickness of 10 μm or more between the surface of the metal member and the fiber-reinforced resin layer. A method for manufacturing a laminate molded body having a structure in which a plurality of fiber reinforced resin layers are laminated and integrated,
the following steps (1) to (4);
Step (1): A step of laminating and setting a plurality of layers of fiber reinforced resin material in a press device whose mold temperature is kept within the range of 160 to 240 ° C.
Step (2): A step of closing the mold and simultaneously laminating and integrating multiple layers of the fiber reinforced resin material by hot press molding,
Step (3): A step of demolding the laminated molded body laminated and integrated at a mold temperature within −10° C. from the mold temperature of the step (1) and removing it from the press device;
Step (4): a step of adjusting the mold temperature to the temperature of step (1);
as one cycle,
Laminate molding characterized in that the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin, and the tact time from step (1) to step (4) is less than 10 minutes. body manufacturing method. Laminate molding according to claim 8, wherein the mold has a fixed mold and a movable mold, and the set temperature of the fixed mold in step (1) is set to a temperature higher than the set temperature of the movable mold by 10 ° C. or more. body manufacturing method. 10. The method for producing a laminated molded product according to claim 8 or 9, wherein the matrix resin of the fiber-reinforced resin layer is a crosslinked cured product of a resin composition containing a phenoxy resin and having thermal crosslinkability at a temperature of 160°C or higher.

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