JP4447120B2 - Manufacturing method of laminated structure and laminated structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated structure useful as a base material for automobile interior materials and a method for producing the same.
[0002]
[Prior art]
Known as interior materials for automobile sunshades or moon roof doors, sandwich-type base materials with a porous body such as a paper honeycomb body or urethane foam as the core, and a fiber reinforcement layer bonded to both surfaces are known. ing. And the surface material formed from PVC etc. is further laminated | stacked on the surface of this base material, and the interior material for motor vehicles is formed.
[0003]
A laminated structure such as a base material of the interior material is lightweight because a porous body is used. Moreover, since it can be easily shaped into a predetermined shape by hot pressing, mass production is possible and the cost can be reduced.
[0004]
In other words, in order to manufacture such a laminated structure, a pre-formed plate-like core material is prepared, thermosetting resin plates such as phenol resin or epoxy resin are laminated on both surfaces of the core material, and further, A plate-like fiber aggregate formed from glass fibers or the like is laminated on the surface of the curable resin plate. When hot pressing is performed, the thermosetting resin plate becomes liquid and is impregnated into both the fiber aggregate and the core material, and is thermally cured in this state to integrally bond the fiber aggregate and the core material. Then, the laminated body is shaped into a predetermined shape by hot pressing, and a sandwich-like laminated structure is formed.
[0005]
In the obtained laminated structure, a thermosetting resin layer is formed between the fiber assembly and the core material, and the thermosetting resin layer is impregnated into the fiber assembly and the core material and cured to integrate the two. Are joined together. In addition, the thermosetting resin layer maintains the shape shaped into a predetermined shape and ensures the rigidity of the laminated structure.
[0006]
And if the skin material made into the predetermined shape by vacuum forming etc. in another process is joined to the surface of the laminated structure obtained above, the interior material of the predetermined shape can be manufactured.
[0007]
JP-A-63-312136 also discloses a similar laminated structure.
[0008]
[Problems to be solved by the invention]
However, the thermosetting resin once becomes liquid by heating, and then the reaction proceeds to cure. Therefore, in the manufacturing method of the laminated structure described above, the thermosetting resin that has become liquid during hot pressing is impregnated deep inside the core material. Thus, the thermosetting resin impregnated deep inside the core material does not contribute at all to the joining of the fiber assembly and the core material. However, if the amount of the thermosetting resin is reduced, the bonding strength between the fiber assembly and the core material will be insufficient, so an excessive amount of thermosetting resin will be required. The cost was high. Further, the weight is increased by the amount of excess thermosetting resin.
[0009]
The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the amount of the thermosetting resin while maintaining a high bonding strength, and to provide a cheap and lightweight laminated structure.
[0010]
[Means for Solving the Problems]
The feature of the manufacturing method of the laminated structure of the present invention that solves the above problems is that the surface of the plate-like core material made of a porous body is cured at a predetermined temperature higher than the melting point of the thermoplastic resin film and the thermoplastic resin film. Alternatively, the adhesive resin to be softened and the fiber assembly are laminated in this order, and then the thermoplastic resin film is melted by heating and pressurizing at a predetermined temperature or higher, and the fiber assembly and the core material are integrally formed with the adhesive resin. It is to join.
[0011]
The laminated structure of the present invention manufactured by the above manufacturing method is characterized by a plate-like core layer made of a porous body, an adhesive resin layer formed on at least one surface of the core layer, and an adhesive resin layer. In a laminated structure including a fiber reinforcing layer integrally bonded to a core layer, a thermoplastic resin layer is provided between the core layer and the adhesive resin layer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the method for producing a laminated structure of the present invention, a thermoplastic resin film, an adhesive resin, and a fiber assembly are laminated in this order on the surface of the plate-shaped core material, and then higher than the melting point of the thermoplastic resin film. The thermoplastic resin film is melted by heating and pressurizing at a predetermined temperature or higher, and the fiber assembly and the core material are integrally bonded with an adhesive resin.
[0013]
At the time of heating and pressing, since the thermoplastic resin film is first melted and impregnated in the core material, the thermoplastic resin impregnated in the core material suppresses the impregnation of the liquid adhesive resin into the core material. If the heating and pressing time is the same as before, the time for the adhesive resin to impregnate the core material is delayed due to the intervention of the thermoplastic resin, and the time required for the impregnation is substantially reduced. Impregnation into the core material is suppressed.
[0014]
Therefore, the amount of adhesive resin that is not impregnated in the core material and intervenes between the fiber assembly and the core material increases, and it is possible to ensure the same bonding strength as before even if the amount of adhesive resin used is reduced. Become. Since the thermoplastic resin is much cheaper than the adhesive resin such as a thermosetting resin, even if the raw material cost increases by the amount of the thermoplastic resin film, the overall cost can be significantly reduced. Further, since the weight of the adhesive resin that is reduced is larger than the weight of the thermoplastic resin film to be used, the weight can be reduced correspondingly.
[0015]
As the core material, a plate-like porous body formed from a paper honeycomb body, a urethane foam, a polymer foam, or the like is used, and the same material as the conventional one can be used. In the case of a honeycomb body, the core material is formed so that the honeycomb passage extends in the thickness direction.
[0016]
As the thermoplastic resin film, a film formed from a thermoplastic resin such as polyethylene, polypropylene, polystyrene, nylon, PVC, vinyl acetate, AS resin, polyester resin, acrylic resin, and thermoplastic elastomer can be used. This thermoplastic resin film is preferably used at a thickness of ²⁰ to 100 g / m ² with respect to the surface of the core material. If the amount of the thermoplastic resin film is less than this range, the intervening effect cannot be obtained, and if it exceeds this range, the effect is saturated, the cost and weight increase, and the bonding strength may be lowered. In addition, it is necessary to use this thermoplastic resin film having a melting point lower than the temperature at which the adhesive resin is cured or softened.
[0017]
The adhesive resin can be bonded to the fiber assembly and the core material by heat and pressure, such as a thermosetting resin such as phenol resin or epoxy resin, or hot melt adhesive, and the laminated structure is shaped into a predetermined shape. Those that can be held in the state are used. A thermosetting resin that can give a certain degree of rigidity after curing or solidification is desirable. A thermosetting foamed resin that foams and hardens can also be used.
[0018]
The shape of the adhesive resin before joining is not particularly limited as long as it can be disposed on the thermoplastic resin film, and can be a sheet, plate, powder, or liquid in some cases. In the case of a thermosetting resin, it goes without saying that a curing agent for curing by heating is included. In the case of a thermosetting resin, the curing temperature needs to be higher than the melting point of the thermoplastic resin film. In the case of a hot melt adhesive, the melting point thereof needs to be lower than the melting point of the thermoplastic resin film. It is desirable that the thermoplastic resin film is melted after the hot melt adhesive is sufficiently melted, and the hot melt adhesive slightly flows to the core material side.
[0019]
In any case, it is desirable that the curing temperature or melting point of the adhesive resin be higher by about 50 ° C. than the melting point of the thermoplastic resin film. If this temperature difference is smaller than about 50 ° C., the time difference between the melting of the thermoplastic resin film and the impregnation of the adhesive resin into the core material becomes small, and the adhesive resin is impregnated deep into the core material.
[0020]
Although the usage-amount of adhesive resin changes also with resin seed | species, generally it is preferable to use so that it may become 50-500 g / m < ² > with respect to the surface of a core material. If the amount of the adhesive resin is less than this range, the bonding strength or shape retention between the fiber assembly and the core material is lowered, and if it exceeds this range, the bonding strength is saturated and the cost and weight are increased.
[0021]
Examples of the fiber assembly include woven fabrics, nonwoven fabrics, knitted fabrics, mats, papers, and the like made of short fibers or long fibers of various fibers such as organic fibers, inorganic fibers, and metal fibers. The amount of the fiber aggregate used varies depending on the fiber type or the apparent density, but generally it is preferably used so as to be 50 to 500 g / m ² with respect to the surface of the core material.
[0022]
And in the manufacturing method of this invention, a thermoplastic resin film is arrange | positioned on the core material surface, adhesive resin is arrange | positioned on it, and also a fiber assembly is arrange | positioned on it. Such lamination may be performed only on one side surface of the core material, or may be laminated on both side surfaces in this way. And it clamps with a predetermined metal mold | die, and heat-presses at predetermined temperature. The predetermined temperature is a temperature at which the thermoplastic resin film is melted and the adhesive resin is cured or melted. The pressurizing pressure can be variously selected depending on the case.
[0023]
The thermoplastic resin film is melted by heating and pressing to expose the pores of the core material and impregnated with the liquid adhesive resin. The liquid adhesive resin also impregnates the fiber assembly. The melting and impregnation of the thermoplastic resin film delays the impregnation of the adhesive resin into the core material, and also reduces the amount of impregnation into the core material. By controlling the mold temperature and the hot press time, the amount of the adhesive resin impregnated can be controlled. As the adhesive resin solidifies, the fiber assembly and the core material are integrally joined to form a laminated structure shaped into a predetermined shape.
[0024]
Therefore, according to the manufacturing method of the present invention, it is possible to manufacture a laminated structure that can secure the same bonding strength as the conventional one with a smaller amount of adhesive resin than the conventional one, and is inexpensive and light.
[0025]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
[0026]
FIG. 1 shows a schematic cross-sectional view of a base material for automobile interior material manufactured by the manufacturing method of this embodiment. The base material includes a paper-made honeycomb core material 1, a thermoplastic resin layer 2 laminated on both surfaces of the core material 1, and a portion of the core material 1 impregnated in the pores, and a thermoplastic resin layer 2. Epoxy resin layer 3 laminated on the surface and partially impregnated into the pores of core material 1 and cured, and glass fiber mat laminated on the surface of epoxy resin layer 3 and partially impregnated and cured The fiber reinforcement layer 4 which consists of these.
[0027]
In the actual cross section, the thermoplastic resin layer 2 has a plurality of openings corresponding to the honeycomb passages of the core material, and a part thereof is impregnated inside the core material 1. Moreover, since most of the epoxy resin layer 3 is impregnated in the core material 1 and the fiber reinforcing layer 4, the boundary is not clear as shown in FIG.
[0028]
Hereinafter, the manufacturing method of this base material is demonstrated, referring FIGS. 2-4, and it replaces with the detailed description of a structure.
[0029]
First, a paper-made honeycomb-shaped core material 1 separately prepared in advance is prepared. The core material 1 has a square cross section and honeycomb passages each having a side of about 5 mm arranged in a grid, and has a plate shape having a thickness of about 5 mm with the extending direction of the honeycomb passage as a thickness direction.
[0030]
Next, a polyethylene (PE) film 2 ′ having a thickness of about 50 μm is prepared and disposed on both surfaces of the core material 1. The PE amount is 50 g / m ² with respect to the surface of the core material 1.
[0031]
Further, a phenol epoxy resin 3 ′ and a glass fiber mat 4 ′ are laminated in this order on the surface of the PE film 2 ′. The phenol epoxy resin 3 ′ is in the form of a powder and is preliminarily attached to the surface of the glass fiber mat 4 ′ made of short glass fibers. In FIG. 2, it is schematically shown separated from the glass fiber mat 4 ′. The phenol epoxy resin 3 ′ has an amount of 500 g / m ² on both sides with respect to the surface of the core material 1. The glass fiber mat 4 ′ has a thickness of 500 g / m ² on both sides with respect to the surface of the core material 1.
[0032]
As shown in FIG. 3, this laminated body 10 is disposed in a mold 5 having a predetermined shape whose temperature is controlled by oil, and as shown in FIG. 4, a temperature of 190 to 210 ° C., 20 kg / cm ^2. Was subjected to hot press molding at a pressure of 60 seconds. Thereafter, the mold was opened, and a substrate having a cross-sectional structure shown in FIG. 1 was obtained.
[0033]
The obtained base material for the interior material is shaped into the mold surface shape of the mold 5, and the core material 1 and the fiber reinforcing layer 4 are impregnated with a part of the epoxy resin layer 3 and cured to form the shape. While being held, the core material 1 and the fiber reinforcing layer 4 are integrally and firmly joined. Further, rigidity is ensured mainly by the epoxy resin layer 3.
[0034]
In the case of the conventional manufacturing method in which the thermoplastic resin film 2 ′ is not interposed, the predetermined bonding strength is required unless the amount of the phenol epoxy resin 3 ′ is 600 g / m ² or more on both sides with respect to the surface of the core material 1. However, in this embodiment, a predetermined adhesive strength can be secured at an amount of 500 g / m ² on both sides with respect to the surface of the core material 1, and the amount of the phenol epoxy resin 3 ′ can be secured on the surface of the core material 1. On the other hand, it was possible to reduce 100 g / m ² . Therefore, according to the manufacturing method of the present example, it was possible to manufacture a base material that is cheaper and lighter than the conventional manufacturing method.
[0035]
【The invention's effect】
That is, according to the manufacturing method of the present invention, it is possible to manufacture a laminated structure that can secure the same bonding strength as the conventional one with a smaller amount of adhesive resin than the conventional one, and is inexpensive and light.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a laminated structure obtained by a manufacturing method according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a laminated structure of each layer in the manufacturing method of one embodiment of the present invention.
FIG. 3 is an explanatory cross-sectional view showing a state in which a laminated body is placed in a mold in the manufacturing method of one embodiment of the present invention.
FIG. 4 is an explanatory cross-sectional view showing a state in which a laminated body is hot-pressed in a mold in the manufacturing method of one embodiment of the present invention.
[Explanation of symbols]
1: Core material 2: Thermoplastic resin layer 2 ′: PE film 3: Epoxy resin layer 3 ′: Phenol epoxy resin 4: Fiber reinforcing layer 4 ′: Glass fiber mat 5: Mold

Claims (2)

A thermoplastic resin film, an adhesive resin that cures or softens at a predetermined temperature higher than the melting point of the thermoplastic resin film, and a fiber assembly are laminated in this order on the surface of a plate-like core material made of a porous material. Then, the thermoplastic resin film is melted by heating and pressing at the predetermined temperature or higher, and the fiber assembly and the core material are integrally joined with the adhesive resin. Method. A plate-like core layer made of a porous body, an adhesive resin layer formed on at least one surface of the core layer, and a fiber reinforcement layer integrally joined to the core layer by the adhesive resin layer A laminated structure comprising a thermoplastic resin layer between the core layer and the adhesive resin layer.

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