JP2008222208A - Withstand load board for automobile, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight withstand load board for an automobile having sufficient strength which has, in particular, the rigidity against a load and the durability against a local load, and a method for manufacturing the withstand load board for an automobile in a simple process. <P>SOLUTION: The withstand load board for the automobile has a core board which is obtained by integrally pressing a laminate structure in which a first fibrous base material, a thermoplastic foam core layer and a second fibrous base material are layered in this order. These fibrous base materials are formed of an interlaced non-woven textile containing fibrous substances and a resin binder. The melting point of a resin component constituting the thermoplastic foam core layer is higher than that of the resin binder. The withstand load board for the automobile is lightweight, and has sufficient strength without using any reinforcing material such as a reinforcement, and can be used for a floor board and a rear package tray. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automobile load bearing board and a method for manufacturing the same. More specifically, the present invention relates to an automobile load bearing board made of a molded body including a resin foam and a method for manufacturing the load bearing board.

  2. Description of the Related Art In recent years, importance has been placed on various parts constituting an automobile to reduce weight for improving fuel efficiency and to use recyclable materials in consideration of the environment.

  For example, woody plywood has been used as an interior member (floor board, door material, ceiling material, rear tray, etc.) constituting the interior of an automobile. The plywood needs to have a sufficient thickness to maintain a certain level of strength. Therefore, it has been pointed out that the use of wood plywood for automobile interior members becomes heavy if the thickness is secured, and the strength is insufficient to achieve weight reduction. Furthermore, the interior member made of plywood also has a problem that it is difficult to recycle. Plywood is also difficult to process to have any desired three-dimensional shape. As a result, there is a risk of restricting the design of the car.

  On the other hand, in buildings such as houses, chemical substances such as formaldehyde (which is a component of adhesives such as plywood) and wood preservatives are gradually released from wooden materials used for building materials, and allergic diseases to the human body Sick house syndrome, which causes symptoms, is a problem. This is a problem that should be a concern even in a relatively small room such as an automobile. From this point of view, the use of plywood tends to be avoided.

  In recent years, resin interior parts for automobiles have been used instead of plywood. Since the resin can be molded into an arbitrary shape, variations can be given to the design of the automobile. However, it has been pointed out that resin-made automotive interior members have a problem in strength.

  Such a problem in strength in the resin automobile interior member is particularly important with respect to a load bearing board (plate material) that requires durability against various loads such as a floor board and a rear package tray.

  The automobile floor board refers to a floor surface that constitutes the interior of the automobile, for example, an openable and closable plate-like member 400 that constitutes a trunk room or luggage room of an automobile as shown in FIG. Automotive floor boards are also called deck boards, luggage (floor) boards, and the like.

  In a vehicle in which a spare tire larger than a normal sedan vehicle is stored in an automobile room, such as an RV vehicle, a floor board covering a portion in which the spare tire is stored must be a relatively large plate. Furthermore, since a passenger's luggage and the like are placed on the floor board, it is not possible to use a material that can be easily bent or damaged by a load. Therefore, when a resin floor board is employed, the strength is improved (particularly, the rigidity with respect to the load and the durability with respect to the local load are improved) so that these problems do not occur. For example, a decrease in strength (that is, a decrease in rigidity with respect to a load) is prevented by arranging or embedding a large number of metal lean hoses in the floor board. However, in practice, the use of a large number of lean hoses increases the mass of the floorboard itself, which contradicts the purpose of weight reduction.

  As a conventional load bearing board for automobiles, for example, an interior part described in Patent Document 1 is known. FIG. 11 is a schematic cross-sectional view showing an example of a load bearing board made of the interior part described in Patent Document 1. As shown in FIG.

  As shown in FIG. 11, a conventional load bearing board for an automobile 500 is formed by sandwiching a core material 530 having an air layer such as a foam material between two base materials 512 and 522. The base materials 512 and 522 are made of a sheet substantially made of a thermoplastic resin such as polypropylene. Further, skin materials 514 and 524 are attached to the outer surfaces of the base materials 512 and 522.

  A conventional automobile load bearing board 500 as shown in FIG. 11 is manufactured using, for example, a seat blowing technique as described in Patent Document 2. That is, it is manufactured by sandwiching the core material 530 between the base materials 512 and 522 previously arranged in the upper and lower molds, and bonding or pressing the base materials 512 and 522 to each other while introducing compressed air. . For this reason, cavities 540 and 544 necessarily exist inside the obtained load bearing board 500 due to the compressed air introduced at the time of manufacture.

  Although the presence of this hollow portion contributes to further weight reduction of the load bearing board, it cannot retain any durability against the load applied to that portion, so that the strength of the load bearing board is maintained (particularly against local loads). It would rather have a negative impact on durability. For this reason, in the conventional load-bearing board, the reinforcement material 360 like a lean hose must be used from the viewpoint of reinforcement, and it is difficult to avoid an increase in mass associated therewith.

  Patent Document 3 discloses a synthetic resin board in which a core sheet made of a thermoplastic resin having a plurality of embossed portions is used as the core material, and the core sheet is in close contact with upper and lower substrates. The synthetic resin board attempts to achieve strength retention by reducing the weight of the board itself by using a plurality of embossed portions and avoiding the use of a reinforcing material such as a lean hose.

  However, when the synthetic resin board described in Patent Document 3 is used as a load-bearing board and various loads are placed on it for a long time, the substrate surface on the load-bearing board (for example, the surface of the skin material), It is conceivable that the mold remains or the base material extends along the concave portions of the plurality of embossed portions existing under the base material, and is always excellent from the viewpoint of appearance and the strength of the upper surface of the concave portion. Not a thing. Furthermore, even if the synthetic resin board described in Patent Document 3 is used, a relatively large floor board mounted on an RV vehicle or SUV vehicle has insufficient strength against a load and is reinforced like a lean hose. The use of materials is not completely avoidable.

  On the other hand, various reinforcements by improving the strength of a substrate (for example, a sheet) have been studied. For example, Patent Document 4 discloses an integrally molded plate-like foam molded article including a plate-like foam, a sheet-like fiber reinforcing material, and a skin material. Since the fiber reinforcing material used in the molded body is made of a resin that is impregnated and solidified in the fiber aggregate and the fiber gap and has the same composition as the foam, the reinforcing material and a part of the surface of the foam Molding is performed in an integrally joined state. However, since the resin solidified in the fiber gaps of the fiber assembly constituting this fiber reinforcement does not necessarily foam, insert reinforcements such as pipes and angles in order to improve load resistance. Is not described, and the use of a reinforcing material is not avoided.

  Alternatively, Patent Document 5 discloses a synthetic panel including a foamed thermoplastic core layer to which a glass fiber mat-reinforced outer layer is attached without an adhesive for the purpose of improving mechanical strength and weight reduction. Yes. Also in this panel, the same group of thermoplastic materials is used for the core layer and the outer layer (glass fiber mat). However, this panel is characterized in that it is more elastic than rigidity, and load resistance and weight reduction are not considered as important.

  In Patent Document 6, at least one or more layers of woven fabric-like fiber reinforcing material and the outermost resin surface layer are superimposed on each other in a vertically symmetrical position on the resin substrate, and are integrated by heating and pressing. A laminate is disclosed. However, in order to obtain sufficient strength, it is necessary to laminate a plurality of fiber reinforcing materials so as to have a ratio of 10 to 40% by volume, and weight reduction is not regarded as important.

  As a reinforcing fiber sheet for the purpose of rigidity and shape retention, there is a fiber sheet in which a thermoplastic resin is bound as a binder and further impregnated with a thermosetting resin having a curing temperature higher than the softening point of the thermoplastic resin ( Patent Document 7). The main purpose of this reinforcing fiber sheet is to maintain its shape, and no consideration is given to weight reduction.

Furthermore, from the viewpoint of imparting a sheet to the surface of the base material, it is known to attach a non-breathable film to the surface of a breathable base material such as a foamable resin for the purpose of preventing contamination of the surface of the base material. (Patent Document 8). In Patent Document 8, since the non-breathable film adhered to the surface has breathability before molding or during molding, hot air is sufficiently sent to the base material which is the inner layer. Here, the non-breathable film is formed at the same time that the breathable substrate surface and the non-breathable film are adhered by heat melting at the time of molding. However, the obtained interior base material is used for a ceiling or the like, and is not intended for a load-bearing board or the like that requires rigidity.
Japanese Patent Laid-Open No. 10-80982 Japanese Patent Laid-Open No. 10-24487 JP 2001-145969 A JP 2002-28997 A Japanese National Patent Publication No. 10-510494 Japanese Patent No. 2721820 JP-A-9-19980 Japanese Patent No. 29999948 JP 2005-68289 A JP 2006-182348 A

  An object of the present invention is to provide a load-bearing board for automobiles that is lightweight and has sufficient strength, in particular, rigidity against load and durability against local load. Still another object of the present invention is to provide a method for manufacturing the above-mentioned automobile load-bearing board by a simple process.

The present invention provides an automotive load bearing board, the automotive load bearing board comprising:
(A) a first fibrous base material comprising an entangled nonwoven fabric containing a first fibrous material and a first resin binder;
(B) a thermoplastic foam core layer;
(C) a second fibrous base material comprising an entangled nonwoven fabric containing a second fibrous material and a second resin binder;
Including a core board obtained by integrally pressing a laminated structure laminated in this order,
The melting point of the resin component constituting the (b) thermoplastic foam core layer is such that (a) the melting point of the first resin binder of the first fibrous base material and (c) the first of the second fibrous base material. It is higher than the melting point of the two resin binder.

  In one embodiment, the (a) first fibrous base material and the (c) second fibrous base material have air permeability.

  In one embodiment, the (a) first fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method.

  In one embodiment, the (c) second fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method.

  In a further embodiment, (a) the first fibrous material of the first fibrous base material and (c) the second fibrous material of the second fibrous base material are composed of inorganic fibers and organic fibers. It is at least one fiber selected from the above.

  In a further embodiment, the first fibrous material and the second fibrous material are glass fibers or kenaf fibers.

  In one embodiment, the entire outer surface of the (b) thermoplastic foam core layer is tightly sandwiched between the (a) first fibrous base material and the (c) second fibrous base material. ing.

  In one embodiment, a first skin material and / or a second material are respectively provided on the outside of the (a) first fibrous base material and / or (c) the second fibrous base material constituting the core board. The skin material is laminated.

  In one embodiment, the automotive load bearing board is a floor board or a rear package tray.

The present invention also provides a method of manufacturing a load bearing board for an automobile, the method comprising:
(A) a first fibrous base material, (b) a thermoplastic foam core layer, and (c) a second fibrous base material arranged in this order to obtain a laminated structure; and the laminated structure Pressing the body together to form a core board;
Including
The (a) first fibrous base material is an entangled nonwoven fabric containing a first fibrous material and a first resin binder,
The (c) second fibrous base material is an entangled nonwoven fabric containing a second fibrous material and a second resin binder, and the melting point of the resin component constituting the (b) thermoplastic foam core layer is Higher than the melting point of the first resin binder of the (a) first fibrous base material and the melting point of the second resin binder of the (c) second fibrous base material.

In one embodiment, the method comprises the steps of obtaining the laminated structure before
The step of preheating the (a) first fibrous base material and the (c) second fibrous base material to a temperature higher than the melting point of the resin component constituting the (b) thermoplastic foam core layer,
Further included.

  In one embodiment, in the step of integrally pressing to form the core board or after the step, the (a) first fibrous base material and the (c) second fibrous base material have air permeability.

  In one embodiment, the (a) first fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method.

  In one embodiment, the (c) second fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method.

  In a further embodiment, (a) the first fibrous material of the first fibrous base material and (c) the second fibrous material of the second fibrous base material are composed of inorganic fibers and organic fibers. It is at least one fiber selected from the above.

  In a further embodiment, the first fibrous material and the second fibrous material are glass fibers or kenaf fibers.

  In one embodiment, in the step of obtaining the laminated structure, the (a) first fibrous base material and the (c) second fibrous group are formed on all outer surfaces of the (b) thermoplastic foam core layer. Arrange the materials so that they are in close contact.

  In a further embodiment, in the step of obtaining the laminated structure, on the outside of the (a) first fibrous substrate and / or (c) the second fibrous substrate constituting the core board, respectively. A first skin material and / or a second skin material is arranged.

  In a certain embodiment, in the process of obtaining the said laminated structure, it arrange | positions so that the said 1st skin material and the said 2nd skin material may closely_contact | adhere to all the outer surfaces of the said core board.

  In one embodiment, in the method, the automotive load bearing board is a floor board or a rear package tray.

  ADVANTAGE OF THE INVENTION According to this invention, even if it does not use a reinforcing material like a lean hose, the load bearing board for motor vehicles which has sufficient intensity | strength can be provided. Further, the load bearing board for automobiles of the present invention has less strength with respect to the load, while it has excellent strength required for the load bearing board, such as rigidity against load and durability against local load, and weight reduction. Since this can be achieved, it is more useful for improving the fuel efficiency of automobiles. Due to its strength and light weight, the load bearing board for automobiles of the present invention can also be used as a floor board for automobiles having a relatively large luggage space such as RV cars. Furthermore, the load bearing board for automobiles of the present invention can be easily manufactured.

  Furthermore, in the load-carrying board for automobiles of the present invention, the first fibrous base material and the second fibrous base material have air permeability, and therefore, between the fibrous base material and the core layer during press molding. The remaining air can easily escape and the fibrous base material and the core layer can be more firmly bonded. By this, a fibrous base material and a core layer adhere | attach more firmly, As a result, high rigidity can be provided over the whole load bearing board. Further, the obtained load bearing board can obtain a smooth and excellent design surface without forming uneven portions such as air pockets on the surface.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  An example of using the load bearing board for automobiles of the present invention (hereinafter sometimes simply referred to as “load bearing board”) as an automobile floor board will be described. FIG. 1 is a schematic diagram for explaining an example of the automotive floor board when the automotive load bearing board 100 of the present invention is used as the automotive floor board.

  The load bearing board for automobiles of the present invention is a kind of interior material or interior board that constitutes the interior surface of an automobile, and includes an interior of an automobile (for example, a passenger compartment or an automobile riding space (residential space) and a luggage space). It is used in a portion where an article such as a luggage or a small article can be arbitrarily placed. The type of automobile in which the load bearing board for automobiles of the present invention can be used is not particularly limited, and includes all automobiles, for example, sedan, sports, specialty, coupe, wagon, station wagon, compact, minivan, cab wagon, 1BOX, 2BOX, recreational vehicle (RV), sports utility vehicle (SUV), vehicles with usually closed living space and luggage space such as light vehicles; and open cars, roadsters, spiders, cabriolets, coupe cabriolets, Examples of the vehicle include a convertible, a phaeton, a barketta, a targa top, a T-bar roof, etc., part or all of which have an open living space and a closed luggage space. Such a load-bearing board is not easily bent or deformed by the load of the mounted article (that is, has an appropriate deflection strength), is highly rigid, and has a local load. It is desirable to have strength against the above, and to be lightweight so that it does not adversely affect the fuel consumption of the vehicle and can be lifted relatively easily by a person. Therefore, the term “load bearing board” used in the present specification is a board having a predetermined durability with respect to a load among the interior material or the interior board, and is loaded with a load through placement of an article or the like. Refers to an interior material or interior board that can be used in a portion where there is a possibility of such a situation.

  FIG. 2 is a schematic view for explaining the internal structure of an example of the load bearing board for automobiles of the present invention, and is a schematic sectional view in the A-A ′ direction of the floor board for automobiles shown in FIG. 1.

  The automobile load bearing board 100 according to the present invention includes a core board 130 that is tightly held between a first skin material 110 and a second skin material 120.

<Core board>
Further, the core board 130 used in the present invention is formed by integrally pressing a first fibrous base material 132, a thermoplastic foam core layer 134, and a second fibrous base material 136 in this order.

<Thermoplastic foam core layer>
The thermoplastic foam core layer 134 used in the present invention is a resin foam in which a plurality of foamed resin particles are in contact with each other and exist uniformly. Thermoplastic foam core layer, preferably ^{0.01g / cm 3 ~0.25g / cm 3} , more preferably has a density of ^{0.03g / cm 3 ~0.1g / cm 3} ( apparent density).

  The material of the thermoplastic foam core layer 134 is such that the melting point of the resin component constituting the thermoplastic foam core layer 134 is the melting point of the first resin binder of the first fibrous base material 132 and the second melting point of the second fibrous base material 136. There is no particular limitation as long as it is higher than the melting point of the resin binder. For example, at least selected from the group consisting of polystyrene, polyethylene, polypropylene, polyphenylene oxide, acrylonitrile-styrene copolymer (AS), acrylate-styrene-acrylonitrile copolymer, and acrylonitrile-butadiene-styrene copolymer (ABS). One type of thermoplastic resin may be mentioned. It is particularly preferable to use polystyrene, acrylonitrile-styrene copolymer (AS), and acrylonitrile-butadiene-styrene copolymer (ABS) in terms of easy molding and relatively high strength of the obtained foam. .

  Such a thermoplastic foam core layer 134 can be generally manufactured based on, for example, the method described in Patent Document 9 or 10, using resin beads impregnated with a foaming agent. Hereinafter, a method for producing the thermoplastic foam core layer 134 will be specifically described.

  Resin beads impregnated with a foaming agent are produced by methods commonly used by those skilled in the art. A description will be given by taking polystyrene beads impregnated with a foaming agent as an example. First, suspension polymerization of styrene is performed, and the obtained beads are classified to obtain polystyrene beads having a desired size. This is suspended in water, and a foaming agent is added thereto under pressure, and the polystyrene beads are impregnated. Alternatively, when the polymerization reaction of styrene progresses by 90% or more, a foaming agent is added under pressure, and polystyrene beads are impregnated with the foaming agent. As the blowing agent, butane, propane, pentane or the like is used. The foaming agent-impregnated resin beads thus obtained are washed, dried, and classified as necessary. A resin other than polystyrene may be impregnated with a foaming agent by a method similar to this.

  The particle size of the resin beads impregnated with the foaming agent thus obtained is preferably 0.6 mm to 2 mm, more preferably 0.8 mm to 1.5 mm. The foaming agent is preferably impregnated in the beads at a ratio of 3% by mass to 7% by mass, more preferably 4% by mass to 6% by mass.

  Next, the resin beads impregnated with the foaming agent are foamed and formed into a desired shape. The thermoplastic foam core layer 134 used in the present invention shown in FIG. 2 is preferably foamed in at least two stages, more preferably a two-stage foaming process of primary foaming and secondary foaming is employed. The That is, when this two-stage foaming process is adopted, in the first stage (primary foaming process), the resin beads are foamed (pre-foamed) to a predetermined bulk density, and then the second stage (secondary foaming process). ) Is molded (secondary foaming) so as to have a predetermined density as a foamed molded product. It is also possible to perform foaming in three or more stages.

  For example, a method for producing the thermoplastic foam core layer 134 used in the present invention by a two-stage foaming process will be described. First, the foaming agent-impregnated resin beads are heated by steam or the like, and foamed (primary foaming) to a predetermined bulk density, preferably at a foaming ratio of 3 to 5 times. The primary foamed beads are aged and then dried to equilibrate the pressure inside the beads. Next, the primary foamed beads are filled into a desired mold and heated, for example, so as to be approximately the same size as the molded product, preferably from 5 times to 5 times based on the volume of the beads before the primary foaming Foaming can be performed at a foaming ratio of 12 times (secondary foaming).

The thermoplastic foam core layer 134 thus obtained is a resin foam obtained by foaming at a foaming ratio of preferably 4 to 12 times, more preferably 5 to 10 times, in total in the foaming step. There, the resin ^{foam, 0.09g / cm 3 ~0.25g / cm} 3, preferably has a density of ^{0.1g / cm 3 ~0.2g / cm 3} ( apparent specific gravity).

  In this resin foam, resin particles after foaming (hereinafter referred to as “foamed resin particles”) are present in contact with each other, and the foamed particles are present uniformly. Here, “uniformly present” means that foamed resin particles having almost the same size and the same degree of foaming exist throughout the resin foam, and the density of the foamed resin particles throughout the resin foam It is almost uniform. In particular, when multi-stage foaming as described above is performed, the resin beads are foamed more uniformly to form foamed resin particles, and the foamed resin particles come into contact with each other to obtain a resin foam that exists uniformly. It is done. Thereby, when the molded object containing this resin foam is used for the load bearing board 100 for motor vehicles, the load concerning the load bearing board 100 can be disperse | distributed to each of the foamed resin particle. Furthermore, according to the multistage foaming, a difference occurs in the degree of foaming between the surface layer portion and the center portion in one foamed resin particle. The central part of the foamed resin particles has a greater degree of foaming than the surface layer part of the particles. Therefore, the surface layer portion of the foamed resin particles is harder than the center portion because the size of the void due to foaming is smaller than that of the center portion. Furthermore, between adjacent foamed resin particles, the particles contact each other through the surface layer portion, and the contact surface is formed on the entire resin foam. As a result, it becomes a structure which comprises a matrix through the surface layer part of all the foamed resin particles which comprise a foam. Therefore, the thermoplastic foam core layer 134 used in the present invention provides excellent strength (particularly, improved rigidity against load and improved durability against local load).

  The size of the foamed resin particles in the thermoplastic foam core layer 134 used in the present invention is preferably 0.8 mm to 3 mm. Thus, by setting it as comparatively small expanded particle, the rigidity with respect to various loads at the time of using for the load bearing board 100 for motor vehicles, and the durability with respect to a local load improve. Moreover, since the resin foam is lightweight, the weight reduction of the automotive load bearing board 100 itself can be achieved.

  Furthermore, the thermoplastic foam core layer 134 used in the present invention can be used again as a resin, for example, by heating and melting and defoaming. Some resins can be dissolved and reused using limonene solvents. In this respect, the thermoplastic foam core layer 134 used in the present invention is easy to recycle and is useful from an environmental and economic viewpoint.

  The size of the thermoplastic foam core layer 134 used in the present invention is not particularly limited because it varies depending on the capacity of the luggage space or rear space of the automobile in which the load bearing board 100 of the present invention is used, the type of automobile, and the like. The thickness of the thermoplastic foam core layer 134 is also not particularly limited. The thickness of the thermoplastic foam core layer 134 is preferably 5 mm to 50 mm, more preferably 10 mm to 30 mm.

  The thermoplastic foam core layer 134 used in the present invention is supported by two fulcrums at intervals of 200 mm in the vicinity of the center of a 75 mm × 300 mm × 15 mm size test piece, and the load speed is 30 mm / min at room temperature. When loaded with an elastic gradient of preferably at least 70 N / 10 mm, more preferably 72-90 N / 10 mm. Here, the elastic gradient (N / 10 mm) represents the stress required for the test piece to bend 10 mm under the above conditions, and the rigidity is higher as the elastic gradient value is larger. When the thermoplastic foam core layer 134 has such a large elastic gradient, sufficient rigidity for a load can be obtained without providing a reinforcing material such as a lean hose in the core layer.

  The thermoplastic foam core layer 134 used in the present invention is also preferably non-breathable as a whole of the core layer.

<First fibrous base material and second fibrous base material>
First, referring to the first fibrous base material 132, as shown in FIG. 2, the first fibrous base material 132 used in the present invention is one surface of the thermoplastic foam core layer 134 (that is, It is laminated on the lower surface side in FIG.

The thickness of the 1st fibrous base material 132 is not specifically limited, Preferably it is 0.8 mm-2.4 mm, More preferably, it is 1 mm-2.2 mm. The first fibrous base material 132 is air permeable so that air staying between the laminated thermoplastic foam core layer 134 and the first skin material 110 can be discharged to the outside of the mold during an integral press described later. It is preferable to have. Due to this air permeability, air that can remain between the laminated materials can be appropriately dispersed between the fibrous materials during the integral pressing. Therefore, not only the formation of air pockets but also the adhesion between the first skin material 110 and the thermoplastic foam core layer 134 centering on the first fibrous base material 134 is enhanced. The air permeability of the first fibrous base material 132 itself used in the present invention is preferably about 1 to 200 cc / cm ² · s. The first fibrous base material 132 may originally be a base material having air permeability, and may be non-breathable before heating, or may be anything that has air permeability after heating.

  Such a 1st fibrous base material 132 consists of an entangled nonwoven fabric containing a 1st fibrous material and a 1st resin binder.

  Examples of the first fibrous material include inorganic fibers, organic fibers, and combinations thereof. Examples of inorganic fibers include glass fibers, carbon fibers, basalt fibers, wollastonite, silica / alumina fibers, zirconia fibers, boron fibers, boron nitride fibers, silicon nitride potassium titanate fibers, and metal fibers. Organic fibers include, for example, natural fibers such as plant fibers and animal fibers; and chemical fibers such as synthetic fibers, regenerated fibers, and semi-synthetic fibers.

  Examples of plant fibers include cotton, hemp, kenaf fiber, bamboo fiber, banana fiber, coconut fiber, and combinations thereof. Animal fibers include, for example, wool, silk, and combinations thereof.

  Synthetic fibers include, for example, polyester fibers (for example, polyethylene terephthalate fibers, polytrimethylene terephthalate fibers, polybutylene terephthalate fibers, polyarylate fibers, and polylactic acid fibers); polyamide fibers (for example, nylon, nylon 6, and nylon 66). Aliphatic polyamide fibers such as aramid fibers and aromatic polyamide fibers such as aramid fibers); polyvinyl alcohol fibers such as vinylon fibers; polyvinylidene chloride fibers such as vinylidene fibers; polys such as polyvinyl chloride fibers Vinyl chloride fiber; Polyacrylonitrile fiber such as acrylic fiber or acrylic fiber; Polyethylene fiber such as polyethylene fiber; Polypropylene fiber such as polypropylene fiber; Like spandex Polyurethane fiber; fluorine-based fibers; polyphenylene sulfide fibers; polyimide fiber; acrylate fibers, ethylene vinyl alcohol fiber; and polyether ester fiber; and combinations thereof. Semisynthetic fibers include, for example, acetate, nitrocellulose fibers, and combinations thereof. Examples of regenerated fibers include rayon, cupra, and combinations thereof.

  In the present invention, among the fibrous materials, glass fibers and / or kenaf fibers are preferably used because the strength can be imparted by the obtained load-bearing board and they are easily available. The appearance of the fibrous material such as fiber diameter, length, aspect ratio, etc. is not particularly limited. These fibrous materials may be either filaments (long fibers) or staples (short fibers).

  In the present invention, the first resin binder that can be used for the first fibrous base material 132 has a melting point lower than the melting point of the resin component that constitutes the thermoplastic foam core layer 134. For this reason, only the first resin binder in the first fibrous base material 132 is partially melted while keeping the shape of the thermoplastic foam core layer 134 stable even by heating at the time of integral pressing described in detail below. The first fibrous base material 132 can be more closely adhered to the surface of the thermoplastic foam core layer 134 (and also to the first skin material laminated on the outside). The melting point of the resin component constituting the thermoplastic foam core layer 134 and the melting point of the first resin binder that can be used for the first fibrous base material 132 are preferably at least 10 ° C., more preferably at least 20 ° C. Preferably there is. When the melting point of the resin component constituting the thermoplastic foam core layer 134 is the same as the melting point of the first resin binder, the thermoplastic foam is obtained by melting the first resin binder by heating during integral pressing. Since the core layer 134 is also melted, the shape of the thermoplastic foam core layer 134 cannot be maintained. Therefore, the manufactured molded article lacks dimensional stability. On the other hand, when the heating temperature at the time of integral pressing is lower than these melting points, the first fibrous base material 132 may be insufficiently adhered to the surface of the thermoplastic foam core layer 134.

  In the present invention, examples of the first resin binder that can be used for the first fibrous base material 132 include polyethylene terephthalate, polypropylene, polyethylene, polystyrene, polyphenylene oxide, acrylonitrile-styrene copolymer, and acrylate-styrene-acrylonitrile copolymer. And acrylonitrile-butadiene-styrene copolymer (ABS), and combinations thereof. As described above, a resin having a melting point lower than that of the resin component is appropriately selected according to the resin component constituting the thermoplastic foam core layer 134.

The mass ratio of the first fibrous material and the first resin binder in the first fibrous base material 132 has a degree of air permeability required at the time of integral pressing described later, and the base material itself by containing a fiber component Considering the purpose of providing viscosity, it is preferably in the range of 10:90 to 90:10, and more preferably in the range of 40:60 to 60:40. Alternatively, the first fibrous substrate 32 is preferably ^{400g / m 2 ~2000g / m 2} , more preferably have a basis weight of ^{500g / m 2 ~1100g / m 2} .

  The first fibrous base material 132 is an entangled nonwoven fabric obtained by entanglement of a fibrous material and a first resin binder using means known to those skilled in the art. Entanglement refers to regular or irregular entanglement of short fibers or filaments. An entangled nonwoven fabric refers to a fiber sheet in which fibers are randomly oriented and the fibers are bonded by alternating current and / or fusion and / or adhesion. The entangled nonwoven fabric is obtained by, for example, a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method. In the present invention, the first fibrous base material 132 has a bonded portion of the first fibrous material bonded or welded with the first resin binder. A fibrous base material comprising such a fibrous material and the first resin binder is commercially available.

  Since the first fibrous base material 132 is an entangled non-woven fabric, the base material itself is difficult to stretch unlike a fabric such as a knitted fabric or a woven fabric. Therefore, when it adheres to the surface of the thermoplastic foam core layer 134, it can have an effect of suppressing the deflection of the thermoplastic foam core layer 134 and imparting rigidity to the core board 130 due to the difficulty of elongation.

  In the present invention, the first fibrous base material 132 and the thermoplastic foam core layer 134 are not shown, but may be laminated in close contact with each other via an arbitrary adhesive layer.

  Next, the second fibrous base material 136 will be described. As shown in FIG. 2, the second fibrous base material 136 used in the present invention is the other surface of the thermoplastic foam core layer 134 (that is, 2 is laminated on the upper surface in FIG. 2 or on the side opposite to the side on which the thermoplastic foam core layer 134 and the first fibrous base material 132 are laminated.

The thickness of the second fibrous base material 136 is also not particularly limited, and is preferably 0.8 mm to 2.4 mm, and more preferably 1 mm to 2.2 mm. Similar to the first fibrous base material 132, the second fibrous base material 136 retains air that is accumulated between the laminated thermoplastic foam core layer 134 and the second skin material 120 during an integral press described later. It is preferable that the air permeability is such that can be discharged to the outside of the mold. Because of this air permeability, air that can remain between the laminated materials can be appropriately dispersed between the fiber components during integral pressing. The air permeability of the second fibrous base material 136 itself used in the present invention is preferably about 1 to 200 cc / cm ² · s. In addition, the 2nd fibrous base material 136 may be a base material which has air permeability from the first, and should just be non-air-permeable before a heating, if it has air permeability after a heating.

  Examples of the material of the second fibrous base material 136 used in the present invention include the same material as the first fibrous base material 132. That is, the second fibrous base material 136 is an entangled nonwoven fabric containing a second fibrous material and a second resin binder, and the second resin binder has a melting point of the thermoplastic foam core layer 134. Lower than the melting point of the constituent resin component. In the present invention, the second fibrous base material 136 and the first fibrous base material 132 may be configured with the same material and size, or are not necessarily completely the same, You may be comprised with a mutually different material and / or magnitude | size.

  In the present invention, the second fibrous base material 136 and the thermoplastic foam core layer 134 are not shown, but may be laminated in close contact with each other via an arbitrary adhesive layer.

  The first fibrous base material 132 and the second fibrous base material 136 used in the present invention contain various fiber components therein as described above. Thereby, even by an integrated press as will be described later, air that can remain between the laminated materials is appropriately dispersed between the fiber components, and a factor that hinders designability such as air retention is also avoided. Rather, with the avoidance of the formation of such air pockets, the adhesion between the skin material centering on each fibrous base material and the thermoplastic foam core layer increases, and the rigidity of the load bearing board 100 and the strength against local loads are improved. . In addition, since the first fibrous base material 132 and the second fibrous base material 136 are entangled nonwoven fabrics containing such a fiber component, the fiber components are entangled with each other in the base material. Since the substrate itself is not easily stretched unlike the woven fabric and the knitted fabric, it also contributes to the rigidity of the load bearing board 100 and the strength against the local load. Further, since the melting point of the resin binder of the fibrous base materials 132 and 136 is lower than the melting point of the resin component constituting the thermoplastic foam core layer 134, the thermoplastic foam core layer 134 is not deformed, and the thermoplastic foam core layer 134 is not deformed. The adhesiveness with the core layer 134 is further enhanced to contribute to the improvement of the rigidity of the load bearing board 100 and the strength against local load.

<First skin material and second skin material>
The first skin material 110 that can be used in the present invention is preferably inferior in breathability to the first fibrous base material 132 and more preferably non-breathable. The first skin material 110 is made of a material that can be used for conventional floorboards or rear package trays such as thermoplastic resin, natural or artificial leather. The thermoplastic resin used for the first skin material 110 is not particularly limited. For example, polyethylene terephthalate, polypropylene, polyethylene, polystyrene, polyphenylene oxide, acrylonitrile-styrene copolymer, acrylate-styrene-acrylonitrile copolymer, acrylonitrile. -Butadiene-styrene copolymer (ABS), and combinations thereof.

The thickness of the first skin member 110 is not particularly limited, preferably ^{10g / m 2 ~500g / m 2} , more preferably the basis weight of ^{50g / m 2 ~300g / m 2} .

  In the present invention, the first skin material 110 preferably completely covers the entire outer surface of the first fibrous base material 132 (that is, the outer side in the stacking direction in the load bearing board of the present invention). Further, although not shown, the first skin material 110 and the first fibrous base material 132 are preferably in close contact with each other via an adhesive layer.

  The second skin material 120 used in the present invention is preferably inferior in breathability to the second fibrous base material 136 and more preferably non-breathable. Similar to the first skin material 110, the second skin material 120 is made of a material that can be used for a conventional floorboard or rear package tray, such as a thermoplastic resin, natural or artificial leather. Examples of the thermoplastic resin used for the second skin material 120 include polyethylene terephthalate, polypropylene, polyethylene, polystyrene, polyphenylene oxide, acrylonitrile-styrene copolymer (AS), acrylate-styrene-acrylonitrile copolymer, acrylonitrile- Examples include, but are not limited to, butadiene-styrene copolymers (ABS) and combinations thereof.

The thickness of the second skin material 120 is not particularly limited, preferably ^{10g / m 2 ~500g / m 2} , more preferably the basis weight of ^{50g / m 2 ~300g / m 2} .

  Examples of the material of the second skin material 120 used in the present invention include the same materials as those of the first skin material 110 described above. In the present invention, the second skin material 120 and the first skin material 110 may be made of the same material and size, or may not necessarily be completely the same, and different materials and It may be configured with a size.

  In the present invention, the second skin material 120 preferably completely covers the entire outer surface of the second fibrous base material 136 (that is, the upper side in the stacking direction in the load bearing board of the present invention). Further, although not shown, the second skin material 120 and the second fibrous base material 136 are preferably in close contact with each other via an adhesive layer.

  FIG. 3 is a schematic view for explaining another example of the load bearing board for automobiles of the present invention, and is a schematic sectional view in the length direction of the floor board for automobiles.

  The load bearing board 200 for automobiles of the present invention shown in FIG. 3 can further improve the rigidity against load and the strength against local load with respect to the load bearing board 100 for automobiles.

  In the automotive load bearing board 200 of the present invention, the thermoplastic foam core layer 134 made of the same material as described above, and two (which, if necessary, via an optional adhesive layer not shown) are tightly sandwiched. The core board 230 is composed of the fibrous base materials (that is, the first fibrous base material 232 and the second fibrous base material 236). Here, the entire outer surface of the thermoplastic foam core layer 134 is tightly sandwiched between the first fibrous base material 232 and the second fibrous base material 236. In other words, in addition to the upper and lower surfaces (or front and back surfaces) of the outer surface of the thermoplastic foam core layer 134, the side surfaces are also covered with either the first fibrous base material 232 or the second fibrous base material 236. Yes. In this case, the melting point of the resin component constituting the thermoplastic foam core layer 134 is higher than the melting point of the first resin binder of the first fibrous base material 232 and the melting point of the second resin binder of the second fibrous base material 236. Therefore, the entire outer surface of the thermoplastic foam core layer 134 can be adhered and covered with the first fibrous base material 232 and the second fibrous base material 236 while maintaining the shape of the thermoplastic foam core layer 134 stably. In this way, by increasing the adhesion area of the first fibrous base material 232 and the second fibrous base material 236 to the thermoplastic foam core layer 134, the space between each fibrous base material and the thermoplastic foam core layer is increased. Thus, the strength of the load-bearing board as a whole and the strength against local loads can be increased. Therefore, in the present invention, in order to further improve the rigidity and strength against local load of such a load bearing board, in addition to all of the upper and lower surfaces of the outer surface of the thermoplastic foam core layer 134, side surfaces Are preferably covered by either the first fibrous base material 232 or the second fibrous base material 236.

  In addition, when the first fibrous base material 232 and the second fibrous base material 236 have air permeability, air that can remain between the laminated materials is moderately contained in each base material during the integrated pressing. Therefore, the outer surface of the thermoplastic foam core layer 134 can be adhered and covered without causing air accumulation. Therefore, when it has a structure like the load bearing board for automobiles 200 shown in FIG. 3, it is preferable that the first fibrous base material 232 and the second fibrous base material 236 have air permeability.

  Furthermore, in this invention, the rigidity with respect to the whole load-bearing board and the intensity | strength with respect to a local load can also be improved further by increasing the contact | adherence area of each fibrous base material and each skin material.

  That is, as shown in FIG. 3, in the automotive load bearing board 200 of the present invention, all of the core board 230 is the same as described above (via an optional adhesive layer not shown). Between the first skin material 210 and the second skin material 220 made of the above materials. In other words, in addition to the top and bottom surfaces (or front and back surfaces) of the outer surface of the core board 230, the side surfaces are also covered with either the first skin material 210 or the second skin material 220. Thus, the contact area to the core board 230 by the first skin material 210 and the second skin material 220 (that is, the contact area to the first fibrous base material 232 and the second fibrous base material 236) is increased. This improves the adhesion strength between each skin material and the core board (that is, the adhesion strength between each skin material and each fibrous base material), and the rigidity of the load bearing board as a whole and strength against local loads Can be further increased. Therefore, in the present invention, in order to further improve the rigidity of the load bearing board and the strength against local load, all of the side surfaces in addition to the upper and lower surfaces of the outer surface of the core board 230 are also included. It is preferably covered with either the first skin material 210 or the second skin material 220.

  In FIG. 3, the end portions of the first fibrous base material 232 and the second fibrous base material 236 and the end portions of the first skin material 210 and the second skin material 220 are respectively load-bearing boards. Although it adhere | attaches in the approximate center part of the thickness direction of 200, in this invention, it is not necessarily limited to these structures.

  For example, in the present invention, as shown in FIG. 4, each end of the first fibrous base material 232 and the second fibrous base material 236 and each end of the first skin material 210 and the second skin material 220. May be bonded to each other at the lower end A in the thickness direction of the load bearing board. By adhering at the lower end A, the side surface of the load bearing board for automobiles of the present invention is substantially covered only with the second skin material 236, and the first skin material 210 and the board even when viewed from the side. There is an advantage that the adhesion portion of the second skin material 220 is hardly visible as a seam line (boundary), and the design property is improved. More specifically, if there is a seam line at such a position, for example, as shown in FIG. 5, it becomes a blind spot of a person who loads and unloads luggage even when an automobile trunk room is actually arranged as a floor board or the like. obtain.

  FIG. 6 is a schematic view for explaining still another example of the load bearing board for automobiles of the present invention. FIG. It is a schematic cross section, (b) is a schematic cross section in the length direction of the automobile load bearing board of the present invention in which only the first skin material is laminated on one side of the core board, and (c) is the core board It is a schematic cross section in the length direction of the automobile load bearing board of the present invention in which only the second skin material is laminated on one side of the.

  As shown in each of (a) to (c) of FIG. 6, in the present invention, as long as the core board 130 is tightly sandwiched between the first skin material 110 and the second skin material 120, the core board 130 is not necessarily provided. Lamination of the first skin material and the second skin material is not essential. That is, as shown in FIG. 6 (a), the core board 130 alone may be used as the automobile load bearing board 300, and as shown in FIG. 6 (b) or (c), Depending on the purpose, the first skin material 110 or the second skin material 120 may be laminated on the outer side of either one of the core boards 130 to form the automobile load bearing board 310 or 320.

  The load bearing boards for automobiles 100, 200, 300, 310, and 320 shown in FIG. 1 to FIG. 3 and FIG. 6 are all shown to have a predetermined thickness and form a plane in the horizontal direction. However, the present invention is not necessarily limited to such a shape. Projections on the core board (more specifically, the thermoplastic foam core layer) itself so that any irregularities can be formed on the load-bearing board surface in order to prevent the articles placed in the luggage space from falling or slipping. A structure may be provided. Furthermore, although the load bearing board 100 of FIG. 1 is represented by a substantially rectangular planar shape, the present invention is not particularly limited to this shape. Depending on the three-dimensional shape in the luggage space, it can have any planar shape. Furthermore, referring to FIG. 1 again, the load bearing board 100 of the present invention may have a gripping portion 106 for facilitating opening and closing of the load bearing board in the luggage space, if necessary. The grip 106 is made of a material such as a synthetic resin such as polypropylene, a metal such as aluminum or stainless steel, and is attached to the board surface.

<Manufacturing method of load bearing board for automobile>
Next, the manufacturing method of the load bearing board for automobiles of the present invention will be described.

  FIG. 7 is a schematic diagram for explaining a procedure for manufacturing the automobile load bearing board 200 of the present invention shown in FIG. 3, and (a) shows the structure of the load bearing board in the mold. It is a figure for demonstrating the state which arrange | positions various materials to order in order, (b) is a figure for demonstrating the state which is pressing the arrange | positioned various materials integrally, and (c) These are the figures for demonstrating the state in the metal mold | die after integrally pressing.

  In the present invention, first, as shown in FIG. 7 (a), on one mold 362, a first skin material 210, a first fibrous base material 232, a thermoplastic foam core layer 134, a first The bi-fibrous base material 236 and the second skin material 220 are arranged in this order, and a “laminated structure” in a state of not being in close contact is formed.

  Here, the thermoplastic foam core layer 134 is preliminarily formed into a desired shape according to the purpose and shape of the load bearing board to be manufactured (for example, use as a floor board or a rear package tray and its shape). . The thermoplastic core layer 134 is also preliminarily coated with an adhesive such as a styrene butadiene rubber (SBR) adhesive on the outer surface as appropriate in order to increase the adhesive strength (for example, substantially uniformly over the entire outer surface). Also good. The amount or thickness of the adhesive that can be applied to the thermoplastic foam core layer 134 can be arbitrarily adjusted by those skilled in the art.

  In the first fibrous base material 232 and the second fibrous base material 236, an adhesive similar to the above increases in advance on the surface facing the first skin material 210 or the second skin material 220, respectively. Therefore, it may be applied as appropriate. Alternatively, an adhesive such as an SBR adhesive may be appropriately applied to both surfaces of the first fibrous base material 232 and the second fibrous base material 236 in advance. The amount or thickness of adhesive that can be applied to the first fibrous substrate 232 and the second fibrous substrate 236 can also be arbitrarily adjusted by those skilled in the art.

  In addition, it is preferable that the 1st fibrous base material 232 and the 2nd fibrous base material 236 are heated to predetermined temperature by the hot platen or the hot air furnace among the said laminated structures, for example. In particular, in the present invention, when laminated in the arrangement of the laminated structure, the surface of the thermoplastic foam core layer 134 is slightly dissolved, and the first fibrous base material 232 and the second fibrous base material 236 are provided. Before forming the laminated structure, the first fibrous base material 232 and the second fibrous base material 232 are formed in order to improve the anchor effect and adhesiveness with each of the first fibrous material and the second fibrous material and the resin binder. Each of the fibrous base materials 236 is preferably preheated to a temperature higher than the melting point of the resin component constituting the thermoplastic foam core layer 134, and is used to sandwich the thermoplastic foam core layer 134. . The heating temperature of such a 1st fibrous base material 232 and the 2nd fibrous base material 236 is 130 to 350 degreeC, for example. On the other hand, the thermoplastic foam core layer 134 does not necessarily have to be heated before being laminated in the arrangement of the laminated structure.

  Next, referring to FIG. 7B, the stacked structure disposed on the mold 362 is integrally pressed along the stacking direction with the other mold 364 from above. At this time, the first fibrous base material 232 and the second fibrous base material 236 are brought into close contact so as to cover the thermoplastic foam core layer 134, and the first skin material 210 is covered so as to cover the first fibrous base material 232. And the second skin material 220 is in close contact so as to cover the second fibrous base material 236. Further, through this press, the thickness direction end of the first fibrous base material 232 and the thickness direction end of the second fibrous base material 236 are in close contact with each other along the inner shape of the molds 362 and 364, and the first The thickness direction end of the skin material 210 and the thickness direction end of the second skin material 220 are in close contact with each other.

  In the integrated pressing step, the air remaining between the stacked materials when the various materials are stacked is discharged in a planar direction through the stacked materials. On the other hand, it is conceivable that a very small amount of air may remain between the materials without being discharged. However, even if such air remains, the first fibrous base material and the second fibrous base material arranged between each skin material and the thermoplastic foam core layer in the present invention Since it is an entangled nonwoven fabric containing a fibrous material as a constituent component, residual air is trapped and uniformly dispersed between the fibrous materials. As a result, it is possible to avoid the formation of ridges such as air pockets that cause the appearance of the load bearing board to be lost on the surface of the first skin material 210 or the second skin material 220. The formation of air pockets causes a decrease in the degree of adhesion between the first fibrous base material 232 and the first skin material 210 and the degree of adhesion between the second fibrous base material 236 and the second skin material 220, respectively. obtain. Therefore, the degree of adhesion can be increased by avoiding air accumulation, the rigidity of the entire load bearing board can be increased, and the strength against local load can be improved.

  In the integrated pressing step, the press pressure applied to the laminated structure is the type and size of the material used as the thermoplastic foam core layer, the first and second fibrous base materials, and the first and second skin materials. Further, since it may vary depending on various parameters such as thickness and the presence or absence of a three-dimensional shape, it is not necessarily limited, and can be arbitrarily adjusted by those skilled in the art. On the other hand, as pressing conditions that can be adopted, the mold temperature is preferably 30 ° C. to 40 ° C., and the pressing time is preferably 10 seconds to 30 seconds.

  After the integrated pressing, as shown in FIG. 7 (c), the mold 364 is opened and the automobile load bearing board 200 of the present invention is taken out. The obtained load bearing board 200 is bonded to the outer peripheral portion (the end portion of the first skin material and the end portion of the second skin material) by means known to those skilled in the art (for example, a burner or a cutter knife) as necessary. It is preferable to further improve the appearance by deburring part.

  In this way, the load bearing board for automobiles of the present invention can be manufactured efficiently. The load bearing board of the present invention is sufficient as an interior component for automobile interiors such as automobile floor boards and rear package trays that are loaded by luggage, etc. without adding a reinforcing material such as a lean hose. Rigidity can be provided. Further, even when a local load is applied by a pointed object such as the tip of an umbrella or a heel portion of a high heel, the formation of irregularities on the surface can be reduced because of sufficient strength. . This also reduces the chance of losing appearance. Furthermore, since the load bearing board of the present invention does not require the use of a reinforcing material, it is possible to reduce the weight of the automobile itself as a lighter interior part, which can contribute to, for example, an improvement in the fuel consumption of the automobile. Moreover, since the load bearing board of the present invention is lightweight and rigid, it can be installed in an automobile so that it can be opened and closed with a one-touch type.

  The load-carrying board of the present invention can be used as a floor lid or an under tray that constitutes an automobile interior, in addition to a floor board and a rear package tray. Furthermore, the load-bearing board of the present invention is not only used in automobiles, but also in fields in which both sufficient strength and light weight are particularly expected (for example, motorcycles such as floor materials and scooters constituting aircraft cabin space). It can also be used for flooring).

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited by these.

<Example 1: Molding of load bearing board by multilayer press (1)>
As a first skin material, a polyethylene terephthalate sheet (A ₁ ) (weight per unit area 100 g / m ² ) subjected to needle punching; as a first fibrous base material, 50% by mass of glass fiber and 50% by mass of polypropylene (PP ) Intertwined nonwoven fabric (B ₁ ) (weight per unit area 750 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.); as a thermoplastic foam core layer, final foaming ratio using the method described in Patent Document 9 Core layer (C ₁ ) (thickness 10 mm) made of acrylonitrile-styrene (AS) beads expanded up to 20 times; as the second fibrous base material, the entangled nonwoven fabric (B ₁ ); and as the second skin material, a two fibrous substrate side, port needle punching is applied with a backing treated backing styrene-butadiene rubber (SBR) and (basis weight 50 g / m ²⁾ Ethylene terephthalate Diroashito the _(A 2) (basis weight 250 g / ^{m 2),} in this order, was placed in 35 ° C. mold temperature regulated press molding machine (Takagi metal Co. OUB350 press)). In this arrangement, the first and second fibrous substrates are pre-heated to 160 ° C., and on each side of the first fibrous substrate, the thermoplastic foam core layer, and the second fibrous substrate, Styrene butadiene adhesive was applied in an amount of 200 g / m ² .

Subsequently, the material laminated as described above (that is, the laminated structure) is integrally pressed at a pressing pressure of 2 kg / cm ² and a pressing time of 20 seconds, and the outer periphery is deburred with a burner to obtain a 700 mm × 500 mm A load bearing board (E1) having a size and a thickness of 12 mm was produced.

<Example 2: Molding of load bearing board by multilayer press (2)>
As a first fibrous substrate and a second fibrous material, instead, constituted out with 50 wt% glass fibers and 50 wt% polypropylene (PP) of the entangled nonwoven fabric used in Example 1 (B ₁₎ AS bead core layer (C ₁₎ used in Example 1 using the entangled nonwoven fabric (B ₂ ) (weight per unit area 800 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.) and as a thermoplastic foam core layer )), Except that an AS bead core layer (C ₂ ) (thickness 10 mm) foamed to a final foaming ratio of 30 times using the method described in Patent Document 9 was used. By the procedure, a load bearing board (E2) having a size of 700 mm × 500 mm and a thickness of 12 mm was produced.

<Comparative Example 1: Molding of load bearing board by seat blow (1)>
As a first skin material, the above-mentioned polyethylene terephthalate sheet (A ₁ ); As a first substrate, a polypropylene (PP) sheet (B _C1 ) (weight per unit area 1200 g / m ² , resin extruded sheet); as a thermoplastic foam core layer, AS bead core layer (C _C1 ) (thickness 11 mm) foamed to a final foaming ratio of 20 times using the method described in Patent Document 9; as the second substrate, the polypropylene sheet (B _C1 ); and second As a skin material, the above-mentioned polyethylene terephthalate made dior sheet (A ₂ ) was placed in this order on a blow molding machine adjusted to a mold temperature of 40 ° C. In this arrangement, the first and second substrates are preheated to 170 ° C., and styrene-butadiene based adhesive is attached to both sides of the thermoplastic foam core layer and each of the first and second substrates. The agent was applied in an amount of 200 g / m ² .

  Next, the obtained laminated structure was blow-molded under vacuum, and the outer periphery was deburred with a burner to produce a load-bearing board (C1) having a size of 700 mm × 500 mm and a thickness of 12 mm. .

<Comparative Example 2: Molding of load bearing board by seat blow (2)>
Instead of the AS bead core layer (C _C1 ) used in Comparative Example 1 as the thermoplastic foam core layer, polypropylene (PP) beads expanded to a final expansion ratio of 20 times using the method described in Patent Document 9. A load bearing board (C2) having a size of 700 mm × 500 mm and a thickness of 12 mm was produced in the same procedure as in Comparative Example 1 except that the core layer (C _C2 ) (thickness 10 mm) was used.

<Example 3: Measurement of deflection amount of load bearing board (1)>
Load bearing boards ((E1), (E2), (C2), and (C2)) and lightweight plywood (K1) (thickness 9 mm, weight per unit area 4000 g) obtained in Examples 1 and 2 and Comparative Examples 1 and 2, respectively. / m ² ), the amount of deflection with respect to a predetermined load was measured according to the following procedure.

First, the load bearing board was disposed so as to be supported at both ends of the short side. Next, a load of 40 kg was applied to the central portion of the load bearing board at 80 ° C., and the vertical distance between the no-load position and the lowest point deflected by the load at the central portion of the load bearing board was the amount of deflection (mm ). FIG. 8 shows the measurement results of the deflection amount (mm) with respect to the basis weight (g / m ² ) of each load bearing board.

  As shown in FIG. 8, it can be seen that in the load bearing boards (E1) and (E2) of the present invention obtained in Examples 1 and 2, the amount of deflection with respect to the basis weight is small. On the other hand, in the load bearing boards (C1) and (C2) obtained by seat blowing obtained in Comparative Examples 1 and 2, the amount of deflection with respect to the basis weight is large. Therefore, the following 1) to 3) can be found by comparing these results with the results of the lightweight plywood (K1).

  1) Although the lightweight plywood (K1) with a small amount of deflection with respect to load is excellent in terms of strength (load resistance characteristics), the basis weight is large in order to obtain the strength. This does not meet the goal of weight reduction in automotive applications, but rather must be avoided.

  2) In the load bearing boards (C1) and (C2) of Comparative Examples 1 and 2, although the basis weight can be reduced as compared with the lightweight plywood (K1), the deflection amount with respect to the load is less than that of the lightweight plywood (K1). Increase significantly. This indicates that the load bearing characteristics are insufficient. For example, when the load bearing boards (C1) and (C2) are used for interior parts for automobile interiors such as floor boards, it means that the load bearing characteristics must be supplemented with a reinforcing material such as a lean hose. However, it can be seen that the use of the lean hose increases the apparent weight of the entire board, and there is substantially no difference from the lightweight plywood (K1).

  3) On the other hand, in the load bearing boards (E1) and (E2) of Examples 1 and 2, the basis weight is remarkably small and the deflection is smaller than that of the lightweight plywood (K1) and the boards of Comparative Examples 1 and 2. The amount is also low. That is, the obtained board simultaneously satisfies both weight reduction and more preferable strength (load bearing characteristics).

<Example 4: Molding of load bearing board by multilayer press (3)>
As the first skin material, the polyethylene terephthalate sheet (A ₁ ); as the first fibrous base material, the entangled nonwoven fabric (B ₃ ) composed of 50% by mass of glass fiber and 50% by mass of polypropylene (PP). (Weighing amount 550 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.); As a thermoplastic foam core layer, acrylonitrile-styrene (AS) beads foamed to a final foaming ratio of 20 times using the method described in Patent Document 9 Core layer (C ₃ ) (thickness 15 mm); the entangled nonwoven fabric (B ₃ ) as the second fibrous base material; and the polyethylene terephthalate made diroa sheet (A ₂ ) as the second skin material in this order. Then, it was placed on a press molding machine (OUB350 press manufactured by Takagi Metals Co., Ltd.) adjusted to a mold temperature of 35 ° C. In this arrangement, the first and second fibrous substrates are pre-heated to 180 ° C. and both sides of the thermoplastic foam core layer, and one side of each of the first and second fibrous substrates ( The surface of the skin material was coated with a styrene butadiene adhesive in an amount of 200 g / m ² .

Next, the obtained laminated structure was integrally pressed at a pressing pressure of 2 kg / cm ² and a pressing time of 20 seconds, and the outer periphery was deburred with a burner to obtain a size of 700 mm × 500 mm and a thickness of 17 mm. A load bearing board (E3) was produced.

<Example 5: Molding of load bearing board by multilayer press (4)>
As a first fibrous substrate and a second fibrous material, instead, constituted out with 50 wt% glass fibers and 50 wt% polypropylene (PP) of the entangled nonwoven fabric used in Example 4 (B ₃₎ AS bead core layer (C ₃₎ used in Example 4 using the entangled nonwoven fabric (B ₄ ) (weight per unit area 790 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.) and as a thermoplastic foam core layer )), Except that an AS bead core layer (C ₄ ) (thickness 15 mm) foamed to a final foaming ratio of 30 times using the method described in Patent Document 9 was used. In the procedure, a load bearing board (E4) having a size of 700 mm × 500 mm and a thickness of 17 mm was produced.

<Comparative Example 3: Molding of load bearing board by seat blow (3)>
As the first skin material, the polyethylene terephthalate sheet (A ₁ ); as the first base material, the polypropylene sheet (B _C1 ) used in Comparative Example 1; as the thermoplastic foam core layer, the method described in Patent Document 9 is used. AS bead core layer (C _C3 ) (thickness 16 mm) expanded to a final expansion ratio of 20 times; the polypropylene sheet (B _C1 ) as the second base material; and the polyethylene terephthalate die as the second skin material. The lower sheet (A ₂ ) was placed in this order on a blow molding machine adjusted to a mold temperature of 40 ° C. In this arrangement, the first and second substrates are preheated to 170 ° C., and both sides of the thermoplastic foam core layer and one side of each of the first and second substrates (surface on the skin material side) The styrene butadiene adhesive was applied in an amount of 200 g / m ² .

  Next, the obtained laminated structure was blow-molded under vacuum, and the outer periphery was deburred with a burner to produce a load-bearing board (C3) having a size of 700 mm × 500 mm and a thickness of 17 mm. .

<Comparative example 4: Molding of load bearing board by seat blow (4)>
Instead of the AS bead core layer (C _C3 ) used in Comparative Example 3 as the thermoplastic foam core layer, polypropylene (PP) beads expanded to a final expansion ratio of 20 times using the method described in Patent Document 9 A load bearing board (C4) having a size of 700 mm × 500 mm and a thickness of 17 mm was produced in the same procedure as in Comparative Example 3 except that the core layer (C _C4 ) (thickness 15 mm) was used.

<Example 6: Measurement of deflection amount of load bearing board (2)>
Regarding the load bearing boards ((E3), (E4), (C3), and (C4)) obtained in Examples 4 and 5 and Comparative Examples 3 and 4, respectively, and the light-weight plywood (K1), Example 3 and In the same procedure, the amount of deflection (mm) with respect to a 40 kg load at 80 ° C. was measured. FIG. 9 shows the measurement results of the deflection amount (mm) with respect to the basis weight (g / m ² ) of each load bearing board.

  As shown in FIG. 9, in the load bearing boards (E3) and (E4) of the present invention obtained in Examples 4 and 5, the amount of deflection with respect to the basis weight is small. On the other hand, in the load bearing boards (C3) and (C4) obtained by seat blowing obtained in Comparative Examples 3 and 4, the amount of deflection with respect to the basis weight is large. Therefore, by comparing these results with the results of the lightweight plywood (K1), the following 4) and 5) can be found.

  4) In the load-bearing boards (C3) and (C4) of Comparative Examples 3 and 4, although the basis weight can be reduced as compared with the lightweight plywood (K1), the deflection amount with respect to the load is less than that of the lightweight plywood (K1). Increase significantly. This indicates that the load bearing characteristics are insufficient. For example, when the load bearing boards (C3) and (C4) are used for interior parts for automobile interiors such as floor boards, it means that the load bearing characteristics must be supplemented with a reinforcing material such as a lean hose. However, it can be seen that the use of the lean hose increases the apparent weight of the entire board, and there is substantially no difference from the lightweight plywood (K1).

  5) On the other hand, in the load bearing boards (E3) and (E4) of Examples 4 and 5, the weight per unit area is significantly smaller than the lightweight plywood (K1) and the boards of Comparative Examples 3 and 4, and the deflection is great. The amount is also low. That is, the obtained board simultaneously satisfies both weight reduction and more preferable strength (load bearing characteristics).

<Comparative Example 5: Molding of load bearing board by multilayer press (5)>
As a first fibrous substrate and a second fibrous material, instead, 50% by weight of glass fibers used in Example 2 and 50 wt% of polypropylene entangled nonwoven fabric used in Example 1 (B ₁₎ AS beads used in Example 1 using an intertwined nonwoven fabric (B ₂ ) composed of (PP) (weight per unit area 800 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.) and as a thermoplastic foam core layer Instead of the core layer (C ₁ ), a polypropylene (PP) bead core layer (C _C4 ) (thickness) expanded to a final expansion ratio of 20 times using the method described in Patent Document 9 used in Comparative Example 4 A load-bearing board (C5) having a size of 700 mm × 500 mm was tried in the same procedure as in Example 1 except that 15 mm) was used. However, the board (C5) had a non-uniform thickness, was not rigid, and a molded product with a stable shape could not be obtained.

<Comparative Example 6: Molding of load bearing board by multilayer press (6)>
As the first base material and the second base material, except that the polypropylene (PP) sheet (B _C1 ) used in Comparative Example 1 was used instead of the entangled nonwoven fabric (B ₁ ) used in Example 1. In the same procedure as in Example 1, an attempt was made to produce a load bearing board (C6) having a size of 700 mm × 500 mm. However, the unevenness | corrugation considered to be due to the air pocket between a core layer and a skin material was clearly seen on the surface of a board (C6), and the molded object with the favorable design property was not able to be obtained.

<Reference Example 1: Measurement of air permeability of fibrous base material>
Used in Example 2 entangled nonwoven fabric (B ₅ ) composed of 50% by mass of glass fiber and 50% by mass of polypropylene (PP) (weight per unit area: 1000 g / m ² , KP sheet manufactured by Cape La Sheet Co., Ltd.) An entangled nonwoven fabric (B ₂ ) composed of 50% by mass of glass fiber and 50% by mass of polypropylene (PP) (weight per unit area 800 g / m ² , KP sheet manufactured by Cape La Sheet Co.), and 50% by mass of kenaf For the entangled nonwoven fabric (B ₆ ) (weight per unit area: 1000 g / m ² ) composed of fibers and 50% by mass of polypropylene, the air permeability was measured for the air permeability tester (KES-F8-AP1: manufactured by Kato Tech Co., Ltd.) It measured using. Each of these sheets was placed in a heated hot stove, the substrate temperature was heated to 160 ° C., and the air flow rate was measured. In addition, the measured value was converted into the air permeability defined in JIS L 1096 air permeability A method (Fragile type method), and this was used as the air permeability. The results are shown in Table 1.

  It was found that the entangled nonwoven fabric used in the present invention has better air permeability after heating than before heating. Therefore, the entangled nonwoven fabric used in the present invention obtains air permeability by preheating before integral pressing, so that air that can remain between the laminated materials during the integral pressing is appropriately set in each group. It is believed that it can be dispersed between the fibrous materials in the material.

<Reference Example 2: Measurement of elastic gradient of thermoplastic foam core layer>
AS bead core layer (C ₃ ) used in Example 4 (thickness 15 mm, basis weight 780 g / m ² ) and C ₃ foamed to a final foaming ratio of 20 times using the method described in Patent Document 9 Elastic gradients were measured for different acrylonitrile-styrene (AS) bead core layers (C ₅ ) (thickness 15 mm, basis weight 850 g / m ² ). Each core layer was made into a size test piece of 75 mm × 300 mm × 15 mm, supported at two fulcrums at intervals of 200 mm near the center, and loaded at the center between the fulcrums at a load speed of 30 mm / min at room temperature. As a result, the elastic gradient is 72N / 10 mm in _{C 3,} and was 90 N / 10 mm in _{C 5.}

<Comparative Example 7: Molding of load bearing board by multilayer press (7)>
As the first substrate and the second substrate, instead, textile sheets (B _C2) (basis weight 800 g / m 2 consisting of glass ^fibers, NS G ve the entangled nonwoven fabric used in Example 1 (B ₁₎ An attempt was made to prepare a load-bearing board (C7) having a size of 700 mm × 500 mm in the same procedure as in Example 1 except that Trotex Co., Ltd. (Twintex) was used. However, the design of the board (C7) after the integrated press is remarkably poor (that is, the end face of the board (C7) is rounded), and it is not necessary to evaluate the amount of deflection. Therefore, it was a molded product that was clearly inferior in design.

  ADVANTAGE OF THE INVENTION According to this invention, the load bearing board for motor vehicles which is lightweight and has sufficient intensity | strength, and its manufacturing method are provided. Such a load-bearing board is useful as an interior part constituting an automobile interior such as a floor board and / or a rear package tray of a passenger car belonging to a type such as a sedan, RV, and SUV. Since the load bearing board of the present invention does not require the use of a reinforcing material, it is possible to reduce the weight of the automobile itself as a lighter interior part, and for example, it can contribute to improving the fuel consumption of the automobile.

It is a schematic diagram for demonstrating an example of the said floor board for motor vehicles, when using the load bearing board for motor vehicles of this invention as a floor board for motor vehicles. FIG. 2 is a schematic diagram for explaining the internal structure of the load bearing board for automobiles of the present invention, and is a schematic sectional view in the A-A ′ direction of the floor board for automobiles shown in FIG. 1. It is a schematic diagram for demonstrating the other example of the load bearing board for motor vehicles of this invention, Comprising: It is a schematic cross section in the length direction of the said floor board for motor vehicles. It is a partial expanded sectional view of the said board for demonstrating the internal structure of the load bearing board for motor vehicles of this invention. It is a schematic diagram for demonstrating the relationship between the said board | substrate at the time of arrange | positioning the load bearing board for motor vehicles of this invention shown by FIG. 4 in a trunk room as a floor board. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram in order to demonstrate the further another example of the load bearing board for motor vehicles of this invention, Comprising: (a) is a schematic cross section in the length direction of the motor vehicle load bearing board of this invention comprised only with a core board. (B) is a schematic cross-sectional view in the length direction of the automobile load bearing board of the present invention in which only the first skin material is laminated on one side of the core board, and (c) is the first cross-section on the one side of the core board. It is a schematic cross section in the length direction of the automobile load bearing board of the present invention in which only two skin materials are laminated. It is a schematic diagram for demonstrating the procedure at the time of manufacturing the load bearing board 200 for motor vehicles of this invention shown by FIG. 3, Comprising: (a) is various materials which comprise a load bearing board in a metal mold | die. It is a figure for demonstrating the state arrange | positioned in order, (b) is a figure for demonstrating the state which is pressing the arrange | positioned various materials integrally, and (c) is integrally pressed. It is a figure for demonstrating the state in a subsequent metal mold | die. It is a scatter diagram showing the result of the amount of deflection (mm) with respect to the basis weight (g / m ² ) of the load bearing board obtained in Examples 1 and 2 and Comparative Examples 1 and 2 measured in Example 3. . It is a scatter diagram showing the result of the deflection amount (mm) with respect to the fabric weight (g / m ² ) of the load-bearing board obtained in Examples 4 and 5 and Comparative Examples 3 and 4 measured in Example 6. . It is a schematic diagram for demonstrating the floor board arrange | positioned in the conventional vehicle rear part, and its periphery. It is a schematic cross section which shows an example of the load bearing board which consists of interior components of patent document 1 as a conventional load bearing board.

Explanation of symbols

100, 200, 300, 310, 320 Load bearing board for automobile 106 Grasping part 110, 210 First skin material 120, 220 Second skin material 130, 230 Core board 132, 232 First fibrous base material 134 Thermoplastic foam core Layer 136, 236 Second fibrous base material 362, 364 Mold 400 Plate member 500 Conventional automotive load bearing board 512, 522 Base material 514, 524 Skin material 530 Core material 540, 544 Cavity 560 Reinforcement material

Claims (21)

A load-bearing board for automobiles,
(A) a first fibrous base material comprising an entangled nonwoven fabric containing a first fibrous material and a first resin binder;
(B) a thermoplastic foam core layer;
(C) a second fibrous base material comprising an entangled nonwoven fabric containing a second fibrous material and a second resin binder;
Including a core board obtained by integrally pressing a laminated structure laminated in this order,
The melting point of the resin component constituting the (b) thermoplastic foam core layer is such that (a) the melting point of the first resin binder of the first fibrous base material and (c) the first of the second fibrous base material. A load-bearing board for automobiles that is higher than the melting point of two resin binders.   The automobile load bearing board according to claim 1, wherein the (a) first fibrous base material and the (c) second fibrous base material have air permeability.   The said (a) 1st fibrous base material is the entangled nonwoven fabric obtained by the cross layer method, the air layer method, the papermaking method, the needle punch method, or the water needle punch method, The Claim 1 or 2 Load bearing board for automobiles.   The (c) second fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method. Load-bearing board for automobiles as described in the section.   The (a) the first fibrous material of the first fibrous base material and the (c) the second fibrous material of the second fibrous base material are at least selected from the group consisting of inorganic fibers and organic fibers. The load-bearing board for automobiles according to any one of claims 1 to 4, which is one kind of fiber.   The load-bearing board for automobiles according to claim 5, wherein the first fibrous material and the second fibrous material are glass fibers or kenaf fibers.   2. All of the outer surface of the (b) thermoplastic foam core layer is tightly sandwiched between the (a) first fibrous base material and the (c) second fibrous base material. The load bearing board for automobiles according to any one of items 1 to 6.   A first skin material and / or a second skin material are respectively laminated on the outside of the (a) first fibrous base material and / or (c) the second fibrous base material constituting the core board. The load-bearing board for automobiles according to any one of claims 1 to 7.   The load bearing board for automobiles according to claim 8, wherein all of the outer surfaces of the core board are tightly sandwiched between the first skin material and the second skin material.   The load-bearing board for automobiles according to any one of claims 1 to 9, which is a floor board or a rear package tray. A method of manufacturing a load bearing board for automobiles,
(A) a first fibrous base material, (b) a thermoplastic foam core layer, and (c) a second fibrous base material arranged in this order to obtain a laminated structure; and the laminated structure Pressing the body together to form a core board;
Including
The (a) first fibrous base material is an entangled nonwoven fabric containing a first fibrous material and a first resin binder,
The (c) second fibrous base material is an entangled nonwoven fabric containing a second fibrous material and a second resin binder, and the melting point of the resin component constituting the (b) thermoplastic foam core layer is Higher than the melting point of the first resin binder of the (a) first fibrous base material and the melting point of the second resin binder of the (c) second fibrous base material,
Method. Before the step of obtaining the laminated structure,
Preheating the (a) first fibrous base material and the (c) second fibrous base material to a temperature higher than the melting point of the resin component constituting the (b) thermoplastic foam core layer,
The method of claim 11, further comprising:   The step (a) of the first fibrous base material and the (c) second fibrous base material have air permeability in or after the step of forming the core board by integrally pressing. The method described.   The (a) first fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method. The method according to the section.   The (c) second fibrous base material is an entangled nonwoven fabric obtained by a cross layer method, an air layer method, a papermaking method, a needle punch method, or a water needle punch method. The method according to the section.   The (a) the first fibrous material of the first fibrous base material and the (c) the second fibrous material of the second fibrous base material are at least selected from the group consisting of inorganic fibers and organic fibers. 16. A method according to any one of claims 11 to 15 which is a single fiber.   The method according to claim 16, wherein the first fibrous material and the second fibrous material are glass fiber or kenaf fiber.   In the step of obtaining the laminated structure, the (a) first fibrous base material and the (c) second fibrous base material are in close contact with all the outer surfaces of the (b) thermoplastic foam core layer. The method according to any one of claims 11 to 17, wherein the method is arranged.   In the step of obtaining the laminated structure, a first skin material and an outer side of (a) the first fibrous base material and / or (c) the second fibrous base material constituting the core board, respectively. 19. A method according to any one of claims 11 to 18, wherein a second skin material is disposed.   The method according to claim 19, wherein in the step of obtaining the laminated structure, the first skin material and the second skin material are disposed so as to adhere to all the outer surfaces of the core board.   21. A method according to any one of claims 11 to 20, wherein the automotive load bearing board is a floor board or a rear package tray.

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