JP7028654B2 - Press molding method - Google Patents

Description

The present invention relates to a press molding method.

Conventionally, as a method of molding a resin in a short molding cycle, a molding method using a mold such as injection molding or press molding is known. When molding the resin, the temperature of the mold is rapidly heated and cooled.
As a method for heating a mold in injection molding or the like, for example, a method of heating the mold using a heating medium that circulates inside the mold such as steam is known (Patent Document 1).

Japanese Patent No. 5354934

However, in recent years, due to the increasing demand for highly efficient production of molding resins having excellent appearance, the method of Patent Document 1 may not sufficiently meet the demands of the market. That is, the current situation is that there is a demand for a method of molding a molding resin having a better appearance shape in a shorter cycle.

Therefore, an object of the present invention is to provide a method for molding a molding resin having an excellent appearance shape in a short cycle.

The present invention is as follows.
[1]
In a state where the resin composite material containing the resin and the continuous reinforcing fiber is arranged in the mold cavity, steam having a temperature of 150 ° C. or higher and a pressure of 0.1 kgf / cm ² or more and 150 kgf / cm ² or less is poured into the mold cavity from 1 to 1. A step of introducing the resin for 15 minutes and melting the resin with the steam, and a step of press molding.
A press molding method comprising.
[2]
The press molding method according to [1], wherein the steam inlet and outlet are provided in the mold cavity.
[3]
The press molding method according to [1] or [2], wherein a sealing mechanism is provided on the parting line of the die.
[4]
A layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less was provided on the inner surface of the steam introduction path to the mold and / or the steam lead-out path from the mold [1] to [3]. The press forming method according to any one of.
[5]
The press molding method according to any one of [1] to [4], wherein a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less is provided on the cavity surface of the mold.
[6]
The resin is selected from the group consisting of a polyolefin resin, a polyamide resin, a polyester resin, a polyether ketone, a polyether ether ketone, a polyether sulfone, a polyphenylene sulfide, a thermoplastic polyetherimide, and a thermoplastic fluororesin. The press molding method according to any one of [1] to [5] , which is at least one type of thermoplastic resin.
[7]
The continuous reinforcing fiber is at least one selected from the group consisting of glass fiber, carbon fiber, aramid fiber, ultra-high strength polyethylene fiber, polybenzazole fiber, liquid crystal polyester fiber, polyketone fiber, metal fiber, and ceramic fiber. The press molding method according to any one of [1] to [6] .

According to the press molding method of the present invention, since it has the above structure, a molding resin having an excellent appearance shape can be molded in a short cycle.

FIG. 1 is a schematic view showing an example of the press molding method of the present embodiment. 1A and 1B are schematic views showing an example of a steam introduction process, and FIG. 1C is a schematic view showing an example of a press molding process. FIG. 1 is a schematic view showing an example of the press molding method of the present embodiment. 1A and 1B are schematic views showing an example of a steam introduction process. FIG. 1 is a schematic view showing an example of the press molding method of the present embodiment. FIG. 1C is a schematic view showing an example of a press molding process. FIG. 2 is a schematic view showing an example of a die used in the press molding method of the present embodiment. FIG. 3 is a schematic view showing an example of a die used in the press molding method of the present embodiment. FIG. 4 is a schematic view showing an example of a die used in the press molding method of the present embodiment.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

In the press molding method of the present invention, a resin composite material containing a resin and a continuous reinforcing fiber is placed in a mold cavity, steam having a temperature of 150 ° C. or higher is introduced into the mold cavity, and at least one of the vapors is used. The step of melting the resin of the part and the step of press molding are included.
The press molding method of the present embodiment may further include steps such as injection.
In the present specification, in a state where the resin composite material containing the resin and the continuous reinforcing fiber is arranged in the mold cavity, steam having a temperature of 150 ° C. or higher is introduced into the mold cavity, and the resin is melted by the steam. The process may be referred to as a "steam introduction process" and a press forming process may be referred to as a "press forming process".

In the conventional press molding method, the heat of the die is used to melt the resin in the die cavity for molding. In this method, there is a temperature difference between the vicinity of the cavity surface of the mold and the inside of the cavity, and the molding raw material cannot be melted uniformly, or the appearance of the obtained molded product deteriorates due to variations in the resin temperature during molding. was there. In particular, when the material to be molded is thick or when a plurality of materials are stacked, the problems of variation in resin temperature during molding and poor appearance are likely to occur.
According to the press molding method of the present invention, since steam is introduced into the mold cavity and the resin composite material in the cavity is directly heated by the steam, not only the portion in contact with the mold cavity surface but also the entire resin composite material is covered. It can be heated efficiently and to a uniform temperature. Further, when a plurality of resin composite materials are arranged in the cavity, vapor can be introduced between the resin composite materials. Further, if voids are present in the resin composite, vapor can be introduced into the resin composite. Therefore, the temperature inside the cavity can be set to a uniform temperature in a short time, and a molded product having an excellent appearance can be obtained.
Further, since the resin composite material can be directly heated, the time required for heating can be reduced and the molding cycle time can be shortened.
Further, since the heating and pressing of the resin composite material can be performed in the same mold without providing a step such as preheating the resin composite material, the molding cycle time can be shortened.

(Steam introduction process)
First, the resin composite material arranged in the steam introduction step and the mold will be described.

-Resin composite material-
The resin composite material contains a resin and a continuous reinforcing fiber, and may further contain other components such as a sizing agent, a binding agent, a mold release agent, a plasticizer, a reinforcing fiber surface treatment agent, a flame retardant, and a lubricant. good.

--resin--
Examples of the resin include thermoplastic resins such as polyolefin resins such as polyethylene and polypropylene; polyamide resins such as polyamide 6, polyamide 66 and polyamide 46; polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and the like. Polyester resin; Polyacetal resin such as polyoxymethylene; Polycarbonate resin; Polyether ketone; Polyether ether ketone; Polyether sulfone; Polyphenylene sulfide; Thermoplastic polyetherimide; Heat of tetrafluoroethylene-ethylene copolymer, etc. Examples thereof include plastic fluororesins and modified thermoplastic resins obtained by modifying them. Of these, crystalline resins are preferable, and for example, polyolefin resins, polyamide resins, polyester resins, polyether ketones, polyether ether ketones, polyether sulfones, polyphenylene sulfides, thermoplastic polyetherimides, and thermoplastic fluororesins. At least one selected from the group consisting of is preferable, and from the viewpoint of mechanical properties and versatility, a polyolefin resin, a modified polyolefin resin, a polyamide resin, and a polyester resin are more preferable, and a viewpoint of thermal properties is added. And, polyamide-based resin and polyester-based resin are more preferable. Further, from the viewpoint of durability against repeated load, the polyamide resin is more preferable, and the polyamide 66 can be preferably used.

The polyester resin means a polymer compound having an —CO—O— (ester) bond in the main chain. For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, poly-1,4-cyclohexylene methylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene naphthalate, polypropylene naphthalate and the like can be mentioned. However, it is not limited to these.
As for the details of other polyester-based resins, those described in JP-A-2015-101794 can be used as appropriate.

The polyamide-based resin means a polymer compound having a -CO-NH- (amide) bond in the main chain. Examples thereof include polyamides obtained by ring-opening polymerization of lactam, polyamides obtained by self-condensation of ω-aminocarboxylic acid, polyamides obtained by condensing diamine and dicarboxylic acid, and copolymers thereof. Not limited to.
As the polyamide, one type may be used alone, or two or more types may be used as a mixture.
As for the other details of the above-mentioned lactam, diamine (monomer) and dicarboxylic acid (monomer), those described in JP-A-2015-101794 can be appropriately used.

Specific examples of the polyamide include polyamide 4 (poly α-pyrrolidone), polyamide 6 (polycabroamide), polyamide 11 (polyundecaneamide), polyamide 12 (polydodecaneamide), and polyamide 46 (polytetramethylene adipa). Mido), Polyamide 66 (Polyhexamethylene adipamide), Polyamide 610, Polyamide 612, Polyamide 6T (Polyhexamethylene terephthalamide), Polyamide 9T (Polynonan methylene terephthalamide), and Polyamide 6I (Polyhexamethylene isophthalamide). , And a copolymerized polyamide containing these as constituents.

Examples of the copolymerized polyamide include a copolymer of hexamethylene adipamide and hexamethylene terephthalamide, a copolymer of hexamethylene adipamide and hexamethylene isophthalamide, and hexamethylene terephthalamide and 2-methylpentanediamine terephthal. Examples include copolymers of amides.

Examples of the shape of the resin include fibrous, film-like, string-like, non-woven fabric-like, woven-like, pellet-like and the like. Further, the resin may be melted and adhered to the continuous reinforcing fiber.

-Continuous reinforcement fiber-
As the continuous reinforcing fiber, those used as ordinary fiber-reinforced composite materials can be used, for example, glass fiber, carbon fiber, aramid fiber, ultra-high strength polyethylene fiber, polybenzazole fiber, liquid crystal polyester fiber. , At least one selected from the group consisting of polyketone fiber, metal fiber, ceramic fiber and the like. Among them, glass fiber, carbon fiber and aramid fiber are preferable from the viewpoint of mechanical property, thermal property and versatility, and glass fiber is preferable from the viewpoint of economy.
The continuous reinforcing fibers may be used alone or in combination of two or more.

When glass fiber is selected as the continuous reinforcing fiber, a sizing agent may be used, and the sizing agent is preferably composed of a silane coupling agent, a lubricant, and a binding agent.
The type of the glass fiber and the sizing agent used for the glass fiber is not particularly limited, and known ones can be used. Specifically, for example, those described in Japanese Patent Application Laid-Open No. 2015-101794 can be used.

Similarly, when carbon fiber is selected as the continuous reinforcing fiber, a sizing agent may be used, and the east collecting agent is preferably composed of a lubricant and a sizing agent.
The type of sizing agent used for the carbon fiber is not particularly limited, and known ones can be used. Specifically, for example, those described in Japanese Patent Application Laid-Open No. 2015-101794 can be used.

Even when other continuous reinforcing fibers are used, the type and amount of the sizing agent that can be used for the glass fiber and the carbon fiber can be appropriately selected and used according to the characteristics of the continuous reinforcing fiber, and the carbon fiber can be used. It is preferable that the type and amount of the sizing agent are the same as those used in the above.

The number of single yarns of the continuous reinforcing fiber is preferably 30 to 15,000 from the viewpoint of handleability.
Further, the fineness of the continuous reinforcing fiber is preferably 1,000 to 30,000 dtex from the viewpoint of handleability.

The continuous reinforcing fiber may be a single yarn or a twisted yarn. Further, it may be a composite yarn composed of two or more kinds of fibers. The continuous reinforcing fiber may be used as a thread as it is, or may be in the form of a string, a cloth, a braid, or the like.

The resin composite material may be, for example, a laminate of a film-like resin and a cloth-like continuous reinforcing fiber, or a braid of a fibrous resin (resin fiber) and a continuous reinforcing fiber, or from the braid. It may be in the form of a cloth, a mixed fiber yarn cloth, a coated yarn cloth, or the like.
The resin composite material may be a braid made of continuous reinforcing fibers and resin fibers, a coated yarn obtained by coating continuous reinforcing fibers with resin, an impregnated yarn obtained by impregnating continuous reinforcing fibers with resin, or the like. It may be a cloth in which threads are knitted. Above all, from the viewpoint that steam easily enters the continuous reinforcing fiber in the resin composite material and the resin composite material can be heated to a more efficient and uniform temperature, the woven fabric and the mixed fiber yarn are assembled. It is preferable that it is a knitted fabric or a knitted fabric in which mixed yarn is knitted.

The method for producing the mixed fiber yarn is not particularly limited, and a known blended fiber method can be used. For example, an open fiber synthetic yarn method in which the continuous reinforcing fibers and the resin fibers are combined and aligned in the opened state after opening the fibers by an external force such as an electrostatic force, a pressure due to fluid spraying, or a pressure pressed against a roller or the like, or an open fiber synthetic yarn method. The fluid interlacing method can be mentioned. Of these, a fluid entanglement method that can suppress damage to the continuous reinforcing fibers, has excellent fiber opening properties, and can be mixed uniformly is preferable. As a fluid interlacing method, two or more eddy current turbulent zones due to fluids such as air, nitrogen gas, and water vapor are created almost parallel to the thread axis, and fibers are guided to these zones to cause loops and crimps. A method of forming non-bulky threads under a certain degree of tension, a method of opening only continuous reinforcing fibers, or a method of fluid entanglement after opening both continuous reinforcing fibers and resin fibers (fluid entanglement after opening). Law) etc. In particular, it is preferable that the resin fibers are subjected to false twisting by themselves in a process including thermal processing, and then continuously mixed by the fluid entanglement method in the same device.
In addition, for details of the mixed fiber method, the method described in JP-A-2015-101794 can be used as appropriate.

The mixed fiber ratio of the continuous reinforcing fiber and the resin fiber is not particularly limited, but is preferably in the range of 15 to 90% in terms of the volume fraction (Vf) of the continuous reinforcing fiber. It can be appropriately set according to the desired strength and rigidity.

The method for producing the coated yarn and the impregnated yarn is not particularly limited, and a known method can be used. The coating and impregnation may be performed at the time of producing the continuous reinforcing fiber, or may be performed in a separate step after producing the continuous reinforcing fiber.

One or a plurality of the resin composite materials may be arranged in the mold cavity.
According to the press molding method of the present embodiment, since the steam is introduced into the mold cavity, the introduced steam enters between the plurality of resin composite materials and into the continuous reinforcing fiber, and the resin composite material is efficiently and uniformly. Can be heated to the temperature of.

The thickness of the resin composite material arranged in the mold is preferably 30 mm or less, more preferably 3 to 20 mm.
According to the press molding method of the present embodiment, the resin composite material can be uniformly heated in the mold even when the resin composite material is thick.
When a plurality of the resin composite materials are stacked and arranged in the mold cavity, the total thickness of the resin composite materials is preferably in the above range.

-Mold-
Examples of the mold include a mold including an upper mold and a lower mold. The mold may be provided with other components, a temperature control mechanism, a thermometer, a pressure gauge, a vent function, and the like.

An example of the above mold is shown in FIG.
FIG. 1A is a mold 1 in a state where the upper mold 2 and the lower mold 3 are open. Between the convex portion of the upper mold 2 and the concave portion of the lower mold 3, there is a mold cavity 7 in which a molding raw material such as a resin composite material 4 is arranged.
FIG. 1B is a mold 1 in a state where the upper mold 2 is lowered and the mold cavity 7 is sealed except for the introduction port 5 and the outlet port 6.
The positions where the introduction port 5 and the outlet port 6 are provided are not particularly limited, but for example, the introduction port 5 and the outlet port 6 are provided at positions facing each other across the composite material when viewed from above the upper mold 2. You may. For example, when the plan view shape of the upper mold is substantially quadrangular, the introduction port 5 and the outlet port 6 may be provided on a part of the sides facing each other across the composite material.

Further, FIG. 2 is another example of the above-mentioned mold.
FIG. 2 shows the mold 1 in a state where the mold cavity 7 is sealed except for the introduction port 5 and the outlet port 6. A sealing material 10 is sandwiched between the upper mold 2 and the lower mold 3, and a gap is formed in which steam introduced from the introduction port 5 passes through the mold cavity 7 and is discharged from the outlet port 6. Further, by pressing after introducing steam, the sealing material 10 is crushed, the introduction port 5 and the outlet port 6 are sealed, and the resin composite material arranged in the mold cavity 7 can be press-molded. The upper die 2 and / or the lower die 3 may be provided with a counterbore in which the sealing material 10 is accommodated during pressing. Although not shown, it is preferable that the resin composite material 4 is arranged in the mold cavity 7.

The shapes of the mold and the mold cavity are not particularly limited, and can be appropriately selected depending on the molded product to be manufactured.
The mold cavity surface of the upper mold and / or the lower mold may have a flat surface, an uneven surface, a corrugated surface, a combination thereof, or the like. According to the press molding method of the present embodiment, since the temperature inside the mold cavity can be made uniform, it is possible to obtain a molded product having an excellent appearance regardless of the shape of the mold cavity surface.

The upper mold and the lower mold of the mold may be provided with a temperature control mechanism such as a heating mechanism and / or a cooling mechanism. Examples of the heating mechanism include flowing a heat medium or the like through a flow path for a heat medium in the mold, incorporating a heater in the mold, and the like. Examples of the cooling mechanism include flowing a refrigerant body and the like through a flow path for the refrigerant body in the mold, incorporating a cooling device in the mold, and the like.

As the material constituting the mold, a steel material is preferable, and examples thereof include carbon steel, alloy steel, and cemented carbide steel.

The mold cavity surface (the surface in contact with the cavity formed between the upper mold and the lower mold during pressing) makes it difficult for the temperature of the steam to change in the mold, and the resin composite material can be melted more uniformly. From the viewpoint of obtaining a molded product having a higher appearance, it is preferable that the surface has a low thermal conductivity, and a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less is provided. It is more preferable that a layer having a thermal conductivity of 80 W · m ^-1 · K ^-1 or less is provided.
The surface having a low thermal conductivity can be formed by, for example, diffusion bonding, adhesion, mechanical bonding, coating, etc., in which a layer made of a metal such as iron or stainless steel or a resin such as PTFE is provided.
In the present specification, the thermal conductivity means a value measured by JIS H7801.

Further, from the viewpoint that the resin can be more efficiently and uniformly melted on the mold cavity surface by heating the resin from the mold surface by the heat conducted from the steam to the mold in addition to the heat of the steam. It is preferable that it is composed of a surface having a high thermal conductivity, and it is more preferable that a layer having a thermal conductivity of 200 W · m ^-1 · K ^-1 or more is provided, ^and the thermal conductivity is 250 W · m-. It is more preferable that a layer having a thickness of ¹ · K ^-1 or more is provided.
The surface having high thermal conductivity can be provided by forming, for example, a layer made of a metal such as aluminum by diffusion bonding, adhesion, mechanical bonding, or the like. For example, the cavity surface of the mold may be a layer having a thickness of 0.1 to 5 mm made of a steel material having a thermal conductivity of 200 W · m ^-1 · K ^-1 or more.
The mold cavity surface may be provided with a surface having a low thermal conductivity and a surface having a high thermal conductivity.
In particular, it is preferable that the inner surface of the mold cavity surface is a surface having a high thermal conductivity, and the surface having a high thermal conductivity is covered with a layer having a low thermal conductivity.

The introduction port for introducing steam into the mold cavity and the outlet for leading out (exhausting) steam to the outside of the mold cavity may be provided in the parting line between the upper mold and the lower mold (the parting line between the upper mold and the lower mold). 1), it may be provided in the lower mold (FIG. 4), it may be provided in the upper mold, or these may be combined.
Further, the number of introduction ports and the number of outlets may be one or a plurality. From the viewpoint of efficiently distributing steam in the mold cavity, the number of inlets may be larger than that of outlets.
Further, it is preferable that the introduction port and the outlet port can be closed during the pressing process.

The inner surface (with steam) of the introduction port and / or the outlet port is from the viewpoint that the temperature of the steam does not easily change in the mold, the resin composite material can be melted more uniformly, and a molded product having a better appearance can be obtained. It is preferable that the contact surface) is composed of a surface having a low thermal conductivity. It is preferable that the inner surface of the introduction port and / or the outlet is provided with a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less, ^and the thermal conductivity is 80 W · m ^-1 · K-. It is more preferable that a layer of ¹ or less is provided.
The surface having low thermal conductivity can be provided by forming, for example, a layer made of a metal such as iron or stainless steel or a resin such as PTFE by diffusion bonding, adhesion, mechanical bonding, coating or the like.

The parting line of the mold may be provided with a sealing mechanism from the viewpoint of melting the resin more efficiently. Examples of the sealing mechanism include an elastomer type and a silicone type, and among them, a silicone type is preferable from the viewpoint of heat resistance.

The cross-sectional area of the introduction port is preferably 10 to 15000 mm ² and more preferably 30 to 10000 mm ² from the viewpoint of efficiently introducing steam into the mold cavity.
The cross-sectional area of the outlet is preferably 10 to 15000 mm ² and more preferably 30 to 10000 mm ² from the viewpoint of efficiently discharging steam to the outside of the mold cavity.
The cross-sectional area of the introduction port and the cross-sectional area of the outlet port refer to the area of the cross section of the port in contact with the mold cavity during the steam introduction process. The cross-sectional area may be the area of a surface perpendicular to the steam flow direction.

As the ratio of the cross-sectional area of the outlet to the cross-sectional area of the inlet (cross-sectional area of the outlet / cross-sectional area of the inlet), steam can be efficiently introduced into the mold cavity, and a molded product having a better appearance can be obtained. From the viewpoint obtained, it is preferably 0.5 to 2, and more preferably 1 to 1.5.

The ratio of the cross-sectional area of the introduction port to the cross-sectional area of the mold cavity (cross-sectional area of the introduction port / cross-sectional area of the mold cavity) is 0. It is preferably 5 to 10, and more preferably 1 to 9.
The ratio of the cross-sectional area of the outlet to the cross-sectional area of the mold cavity (cross-sectional area of the outlet / cross-sectional area of the mold cavity) is 0. It is preferably 5 to 10, and more preferably 1 to 9.
The cross-sectional area of the mold cavity means the area of the cavity cross section cut substantially perpendicular to the cavity surface of the upper mold and the cavity surface of the lower mold in the portion where the resin composite material of the mold cavity is arranged. The cross-sectional area may be the area of a surface perpendicular to the steam flow direction.

The introduction port 5 and the outlet port 6 provided in the mold 1 may be connected to the steam introduction path 8 or the steam outlet path 9 (FIG. 3). The steam may be introduced into the mold cavity 7 from the steam introduction path 8 through the introduction port 5, and discharged from the outlet port 6 to the outside of the mold cavity through the steam outlet path 9.

The steam introduction path and / or the steam lead-out path has an inner surface (a surface in contact with steam) from the viewpoint that the temperature of steam is less likely to change, the resin composite material can be melted more uniformly, and a molded product having a better appearance can be obtained. ) Is preferably composed of a surface having a low thermal conductivity. The inner surface of the steam introduction path and / or the steam lead-out path is preferably provided with a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less, and has a thermal conductivity of 80 W · m ^-1 ·. It is more preferable that a layer having K ^-1 or less is provided.
The surface having low thermal conductivity can be provided by forming, for example, a layer made of a metal such as iron or stainless steel or a resin such as PTFE by diffusion bonding, adhesion, mechanical bonding, coating or the like.

1A and 1B are also views showing an example of a steam introduction process.
FIG. 1A is a diagram showing a state in which the resin composite material 4 is arranged in the mold cavity 7. A plurality of the resin composite materials 4 to be arranged may be laminated by laminating in the surface direction in which the cavity surface of the upper mold and the cavity surface of the lower mold face each other or in the direction orthogonal to the surface direction.

FIG. 1B is a diagram showing a state in which the upper mold 2 is lowered, the mold is closed except for the introduction port 5 and the outlet port 6, and the mold cavity 7 is sealed. Steam is introduced into the mold cavity 7 from the introduction port 5 to melt at least the resin in the resin composite material 4. All the resins in the resin composite may be melted or some may be melted, but from the viewpoint of uniform melting, all the resins (for example, 50% by mass of the above resin in the resin composite material) may be melted. Above, preferably 90% by mass or more) is preferably melted. In FIG. 1B, in the mold cavity 7, there is a gap through which steam passes between the resin composite material and the upper mold, between the resin composite material and the lower mold, and between a plurality of resin composite materials. Is preferable. Further, since the resin composite material is not pressed, if there are voids in the resin composite material, vapor can enter into the voids.
In the steam introduction step, the continuous reinforcing fibers may or may not be melted. Above all, from the viewpoint of obtaining a molded product having excellent strength, it is preferable that the continuous reinforcing fibers do not melt.
In the steam introduction step, steam is introduced into the mold cavity with the resin composite material arranged in the mold cavity. The steam may be introduced in a state where the mold is open or in a state where the mold is closed. Above all, from the viewpoint of efficiently melting the resin, it is preferable to introduce steam with the mold closed. Here, the state in which the mold is closed is a state in which the mold cavity is closed except for the introduction port and the outlet.

Examples of the steam introduced in the steam introduction step include a mixed phase of air and water, a mixed phase of an inert gas and water, and superheated steam.
Above all, superheated steam is used from the viewpoint that oxidative deterioration of the resin composite material is less likely to occur due to the low oxygen concentration, hydrolysis of the resin composite material by water is less likely to occur, and it is easy to obtain a molded product having excellent strength and appearance. preferable.

The temperature of the steam is 150 ° C. or higher, preferably 200 to 1000 ° C., and more preferably 300 to 900 ° C.
Above all, from the viewpoint of efficiently melting the resin without melting the continuous reinforcing fibers to obtain a molded product having higher strength, the temperature is equal to or higher than the melting start temperature of the resin and lower than the melting starting temperature of the continuous reinforcing fibers. It is preferable, and more preferably, it is "the melting start temperature of the resin + 20 ° C." or more and "the melting start temperature of the continuous reinforcing fiber −100 ° C." or less.
The temperature of steam means the temperature inside the mold cavity. The melting start temperature of the resin means the temperature at which the resin begins to melt in the mold cavity, and can be measured by, for example, a differential thermal analysis test, a differential scanning calorimetry, or the like in accordance with JIS K7121.

The time for introducing the steam is preferably 0.5 to 20 minutes, more preferably 1 to 15 minutes, from the viewpoint of efficiently melting the resin and suppressing modification and decomposition of the resin composite material.

The pressure of the steam is preferably 0.1 kgf / cm ^{2 or more, more preferably 0.2 kgf / cm 2 or} more, still more preferably 0., From the viewpoint of efficiently introducing the steam into the mold cavity. It is 3 kgf / cm ² or more. The upper limit may be 150 kgf / cm ² .
The steam pressure means the pressure of the steam to be introduced.

(Press molding process)
Although other steps may be provided between the steam introduction step and the press molding step, it is preferable to perform the press molding step continuously with the steam introduction step.

FIG. 1C is a diagram showing an example of a press molding process.
FIG. 1C is a diagram showing a state in which the upper die 2 and the lower die 3 are molded and the resin composite material 4 is pressed. From the viewpoint of the appearance of the molded product at the time of pressing, it is preferable that the introduction port 5 and the introduction port 6 are closed.

In the press molding step, the temperature at the time of pressing is preferably 100 to 1000 ° C, more preferably 200 to 800 ° C.
The temperature at the time of pressing means the temperature inside the die cavity at the time of pressing.

In the press molding step, the press time is preferably 0.5 to 20 minutes, more preferably 1 to 15 minutes.

In the press molding step, the press pressure is preferably 1 to 300 kgf / cm ² , more preferably 2 to 290 kgf / cm ² .

In the press molding method of the present embodiment, as the ratio of the thickness of the molded product after press molding (thickness of the molded product / thickness of the resin composite material) to the thickness of the resin composite material arranged in the mold cavity. Is preferably 0.01 to 1 from the viewpoint that steam easily enters the continuous reinforcing fiber in the resin composite material and the resin composite material can be heated to a more efficient and uniform temperature. Is 0.05 to 0.8.

As the press molding method of the present embodiment, for example, as a resin composite material, a cloth-like woven fabric (thickness 2 mm) woven with a mixed fiber of a resin fiber made of polyamide 66 and a continuous reinforcing fiber made of glass is 5 A method of stacking sheets, arranging them in a mold cavity, introducing steam at a temperature of 600 ° C. and a pressure of 3 MPa for 5 minutes, and press molding under the conditions of a press mold temperature of 30 ° C., a press time of 5 minutes, and a press pressure of 10 MPa, etc. Can be mentioned.

(Molding)
The shape of the molded product obtained by the press molding method of the present embodiment is not particularly limited, and examples thereof include a plate shape, a spherical shape, a polygonal columnar shape, a polygonal pyramid shape, a substantially cylindrical shape, and a substantially conical shape. Good shape.

The content of the continuous reinforcing fiber in the molded product is preferably 30% by mass or more, more preferably 40% by mass or more.

Applications of the molded product obtained by the press molding method of the present embodiment include, for example, steering shaft, mount, sun roof, step, souf trim, door trim, trunk, boot lid, bonnet, seat frame, seat back, retractor, and retractor support. Brackets, clutches, gears, pulleys, cams, argers, elastic beams, buff rings, lamps, reflectors, glazing, front end modules, back door inners, brake pedals, handles, electrical components, sound absorbing materials, door exteriors, interior panels, instrument panels , Rear gate, ceiling tension, seat, seat frame, wiper support, EPS (Electric Power Steering), small motor, heat sink, ECU (Engine Control Unit) box, ECU housing, steering gearbox housing, plastic housing, EV (Electric Vehicle) For motor housing, wire harness, in-vehicle meter, combination switch, small motor, spring, damper, wheel, wheel cover, frame, subframe, side frame, two-wheel frame, fuel tank, oil pan, in-mani, propeller shaft, drive Motors, monococks, hydrogen tanks, fuel cell electrodes, panels, floor panels, exterior panels, doors, cabins, roofs, hoods, valves, EGR (Exhaust Gas Recirculation) valves, variable valve timing units, connecting rods, cylinder bores, members (Engine mounting, front floor cloth, footwell cloth, seat cloth, inner side, rear cloth, suspension, pillar lean force, front side, front panel, upper, dash panel cloth, steering), tunnel, fastening insert, crash box, crash Rails, corrugated roof rails, upper body, side rails, braiding, door surround assembly, airbag parts, body pillars, dash to pillar gussets, suspension towers, bumpers, body pillar lowers, front body pillars, reinforcements (instrument panel) , Rails, roofs, front body pillars, roof rails, roof side rails, rockers, door belt lines, front floor unders, fronts Tobody pillar upper, front body pillar lower, center pillar, center pillar hinge, door outside panel), side outer panel, front door window frame, MICS (Minimum Intrusion Cabin System) bulk, torque box, radiator support, radiator fan, Water pump, fuel pump, electronically controlled throttle body, engine control ECU, starter, alternator, manifold, transmission, clutch, dash panel, dash panel insulator pad, door side impact protection beam, bumper beam, door beam, bulkhead, outer pad, inner Pads, rear seat rods, door panels, door trim body subassemblies, energy absorbers (bumpers, shock absorbers), shock absorbers, shock absorbing garnishes, pillar garnishes, roofside inner garnishes, crash boxes, resin ribs, side rail front spacers, side rails Rear spacer, seat belt pretensioner, airbag sensor, arm (suspension, lower, hood hinge), suspension link, shock absorbing bracket, fender bracket, inverter bracket, inverter module, hood inner panel, hood panel, cowl louver, cowl top Outer front panel, cowl top outer panel, floor silencer, dump sheet, hood insulator, fender side panel protector, cowl insulator, cowl top ventilator looper, cylinder head cover, tire deflector, fender support, strut tower bar, mission center tunnel, floor tunnel , Radio core support, luggage panel, automobile parts such as luggage floor, aircraft parts, electronic parts and the like.

1 Mold 2 Upper mold 3 Lower mold 4 Resin composite material 5 Inlet port 6 Outlet port 7 Mold cavity 8 Steam introduction path 9 Steam outlet path

Claims (7)

In a state where the resin composite material containing the resin and the continuous reinforcing fiber is arranged in the mold cavity, steam having a temperature of 150 ° C. or higher and a pressure of 0.1 kgf / cm ² or more and 150 kgf / cm ² or less is poured into the mold cavity from 1 to 1. A step of introducing the resin for 15 minutes and melting the resin with the steam, and a step of press molding.
A press molding method comprising. The press molding method according to claim 1, wherein the steam inlet and outlet are provided in the mold cavity. The press molding method according to claim 1 or 2, wherein a sealing mechanism is provided on the parting line of the die. Any of claims 1 to 3, wherein a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less is provided on the inner surface of the steam introduction path to the mold and / or the steam lead-out path from the mold. The press molding method according to item 1. The press molding method according to any one of claims 1 to 4, wherein a layer having a thermal conductivity of 100 W · m ^-1 · K ^-1 or less is provided on the cavity surface of the mold. The resin is selected from the group consisting of a polyolefin resin, a polyamide resin, a polyester resin, a polyether ketone, a polyether ether ketone, a polyether sulfone, a polyphenylene sulfide, a thermoplastic polyetherimide, and a thermoplastic fluororesin. The press molding method according to any one of claims 1 to 5 , which is at least one type of thermoplastic resin. The continuous reinforcing fiber is at least one selected from the group consisting of glass fiber, carbon fiber, aramid fiber, ultra-high strength polyethylene fiber, polybenzazole fiber, liquid crystal polyester fiber, polyketone fiber, metal fiber, and ceramic fiber. The press molding method according to any one of claims 1 to 6 .

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