JP5060613B2 - Method for forming vehicle interior member - Google Patents

Description

The present invention relates to a method for molding an interior member for a vehicle that is excellent in rigidity and adhesiveness, and more particularly to a method for molding an interior member for a vehicle that is formed by laminating a skin material on a base material made of a stampable sheet.

  The stampable sheet is a composite material composed of a reinforcing fiber such as glass fiber or carbon fiber and a thermoplastic resin, and is a sheet-like material suitable for forming a large member by heating and expanding. Such stampable sheets have been put to practical use in automobile interior members and the like in recent years because they can be molded into complex shapes and the molded products have high strength and are lightweight. Since this stampable sheet contains reinforcing fibers that have been opened to a state of almost single fibers, when heated again to a temperature above the melting point of the resin and below the decomposition point, the reinforcing fibers restrained by the resin will spring back. Raising, it becomes an inflatable sheet that has expanded to several times the original thickness. The expanded sheet is used for compression molding, vacuum forming, pressure forming, and the like, and enables formation of a lightweight stampable sheet having a predetermined shape. In other words, by adjusting the mold clearance during molding to be larger than the theoretical thickness (thickness when the porosity of the product is zero), the porous material has a lower density and higher surface rigidity than the stampable sheet. Can be obtained (Patent Document 1).

  The above expansion-molded article is a porous body having a three-dimensional network structure in which reinforcing fibers oriented in a random direction are entangled and fixed and bonded by a molten and solidified thermoplastic resin. Since the rigidity of such an expansion molded product is proportional to the product of the elastic modulus and the cube of the thickness, it is effective to increase the elastic modulus or increase the thickness in order to increase the rigidity. In order to increase the thickness of the expansion molded product, there are a method of increasing the thickness of the stampable sheet as a material and a method of increasing the expansibility of the stampable sheet. However, increasing the thickness of the stampable sheet itself is not preferable because it increases the weight. Moreover, since the expansibility of the stampable sheet depends on the action of the springback of the reinforcing fiber, there is a limit to increasing the expansibility.

  For this purpose, heat-expandable particles that have the property of expanding when heated are mixed in the stampable sheet, and this is heated and expanded to forcibly increase the thickness of the sheet without increasing the weight. The technique which performs is proposed (for example, patent document 2). Here, the heat-expandable particles are generally particles having a core-shell structure with a diameter of about several tens of μm, the core is a liquid hydrocarbon, and the shell is made of a thermoplastic resin having gas barrier properties, When this is heated, hydrocarbons are vaporized and expanded, and the thermoplastic resin is softened, and many are used that expand into a spherical shape with a diameter of about several hundreds of micrometers.

  Moreover, in the above-mentioned expansion molded product, when used for a member that requires decorative properties, for example, a ceiling member of an automobile, generally, a decorative skin material is laminated on the stampable sheet (or expansion sheet) and bonded. It is performed to make it the bonding member formed (for example, patent documents 3, 4). The automobile interior material composed of such a bonding member includes not only high rigidity but also a stampable sheet or an expansion sheet (hereinafter, both the stampable sheet and the expansion sheet are also referred to as “base material”) and a skin material. High adhesive strength is strongly required between them.

  As a pasting technique for such a pasting member, conventionally, it is conceivable to unify and integrate an inflatable sheet and a decorative skin material simply by heating and pressing without an adhesive. However, in simple lamination without an adhesive layer between the expansion sheet and the skin material, the contact area between the expansion sheet and the skin material with a large porosity is small, and the adhesive component at the time of lamination exists in the surface layer of the expansion sheet In order to mold the bonding member while maintaining the expanded state of the expansion sheet, the molding pressure at the time of bonding is small, and therefore from the inside of the expansion sheet to the surface Therefore, sufficient adhesion strength between the expansion sheet and the skin material cannot be expected. In particular, in the case where the heat-expandable particles are included in the expandable sheet, it is said that the heat-expandable particles can hinder the adhesion between the expandable sheet and the skin material, and thus cannot be put into practical use without an adhesive. ing.

  For this purpose, it is a common practice to integrate the two by interposing an adhesive layer between the expansion sheet and the skin material. For example, in Patent Document 3, the adhesiveness between the expansion sheet and the skin material is improved by pressure molding in a state where a heat-fusible adhesive type adhesive is interposed between the expansion sheet and the skin material. Technology is known. In this prior art, a heat-fusible adhesive layer is stacked on a stampable sheet and then placed in a heating furnace to foam the heat-expandable particles into an expandable sheet, and the heat-fusible adhesive is melted and heated. After taking out from the furnace and stacking the skin material while the heat-fusible adhesive on the expansion sheet is in a molten state, it is placed in a cold press mold and molded. In this conventional technology, the skin material is bonded to the base material with a heat-fusible adhesive, but the melted heat-fusible adhesive penetrates into the voids of the porous expansion sheet as the base material. Therefore, it does not remain between the expansion sheet and the skin material, and a so-called effective adhesion impregnation layer is not formed. For this reason, there is a problem that the adhesion between the expansion sheet and the skin material is not sufficient, and the air permeability is poor. Therefore, the number of heat-fusible adhesive type adhesives is increased, or another film material is interposed. In this case, an increase in weight and an increase in cost are caused, which is not preferable. Further, since this heat-expandable particle becomes a factor that hinders the adhesion between the expandable sheet in which the stampable sheet is expanded and the skin material, a heat-fusible adhesive type adhesive as described above may be used. Sufficient adhesive strength cannot be obtained.

  Moreover, in patent document 4, when producing a stampable sheet, the heat-expandable particles are unevenly distributed on one side, and the heat-expandable particles are expanded by heating the stampable sheet in which the heat-expandable particles are unevenly distributed. After making it into an inflatable sheet, the base material is crafted, such as by overmolding the skin material on the surface of the inflatable sheet on which the heat-expandable particles are not unevenly distributed, and pressing with a mold. Is disclosed.

  In Patent Document 4, a foam liquid in which reinforcing fibers, a thermoplastic resin, and heat-expandable particles are uniformly dispersed in a surfactant-containing aqueous medium containing microbubbles is prepared. Then, the web is heated, pressurized, and cooled to prepare a stampable sheet. When manufacturing an expansion molded product, the stampable sheet is heated, and the heat-expandable particles are expanded to form an expanded sheet. After the skin material is overlaid on the expanded sheet, the mold is pressed with a cold mold. A method of manufacturing an expanded molded article in which a skin material is superimposed on one surface of an expanded sheet by cooling is disclosed. In particular, during the papermaking, by defoaming by suction and unevenly spreading the heat-expandable particles on either side of the web, the heat-expandable particles are unevenly distributed on one surface side, When the expandable sheet is manufactured by heating and expanding the stampable sheet, the heat-expandable particles are unevenly distributed on one surface side of the expandable sheet. Then, it is disclosed that the skin material is laminated on the surface side of the expansion sheet on which almost no heat-expandable particles are present, pressure-molded with a mold, and an expansion molded product in which the skin material is bonded to the base material is obtained. . However, this technique requires a special manufacturing method in order to make the heat-expandable particles unevenly distributed in one direction, and has a limit in improving rigidity because it is unevenly distributed in one direction.

JP-A-60-179234 JP 2000-328494 A Japanese Patent Laid-Open No. 02-045135 JP 2006-342437 A

  In prior arts such as Patent Documents 3 and 4, a stampable sheet is manufactured once from a web, and then the stampable sheet is heated to expand the heat-expandable particles in the stampable sheet to manufacture an expanded sheet. Then, since there is a step of stacking the skin material on the expansion sheet and press-molding with a mold, there is a concern that the adhesion between the expansion sheet and the skin material is insufficient. Moreover, the weight of the base material is increased to ensure rigidity, and the weight cannot be reduced. That is, when the heat-expandable particles are included in the stampable sheet, the adhesion between the base material and the skin material is insufficient, and the rigidity of the obtained molded member is not satisfactory. Conventionally, it is a lightweight product that includes heat-expandable particles in a stampable sheet, and is made of a bonding member that can sufficiently satisfy both the rigidity of the base material and the adhesion between the base material and the skin material. It was difficult to obtain interior materials.

  An object of the present invention is to solve the above-mentioned problems, and in particular, by including heat-expandable particles in the stampable sheet, the thickness at the time of sheet expansion can be increased, and the stampable sheet and skin material It is in obtaining the bonding member which can fully satisfy | fill both the rigidity ensuring of the bonding member which consists of, and the adhesiveness of a stampable sheet | seat and a skin material.

  In order to achieve the above-mentioned object, the present inventors can change the process of pasting the skin material on the expansion sheet after expanding the heat-expandable particles in the conventional stampable sheet to form the expansion sheet. We focused on this point.

  And I challenged what would happen if the process was reversed. That is, it was investigated whether the skin material could be expanded on the stampable sheet before the heat-expandable particles were heated and expanded, and then the stampable sheet could be expanded. When the heat-expandable particles were expanded after the stampable sheet and the skin material were bonded together, it was presumed that the bonding portion between them would be peeled off by this expansion process, so this method seemed reckless. However, in order to bond the skin material to the expansion sheet after the stampable sheet has expanded, it is necessary to prevent the expansion state of the expansion sheet from being compressed, and there is a limit to the bonding process. was there. Therefore, although the present inventors seem to be reckless at first glance, they have intensively studied by sticking to the above method.

  Actually, an adhesive layer is simply provided on the surface of the stampable sheet first, and a skin material is overlaid on the surface of the stampable sheet and adhered with the adhesive layer. And it expanded by heating in this state. However, the adhesion of the skin material was insufficient. That is, when heated, the adhesive layer melts and penetrates into the base material, resulting in insufficient adhesive force, and the heat-expandable particles expand to weaken the adhesive force between them. That also led to a lack of adhesion.

  For that purpose, further research was carried out. In the same manner as described above, various tests were tried in consideration of first bonding the skin material to the stampable sheet and then expanding the heat-expandable particles. In that context, we sought not to rely on adhesion with an adhesive as described above, but to be able to attach a skin material to a stampable sheet. In the process, we tried to bond the stampable sheet by heating and compressing the skin material.

Stacking a stampable sheet containing a heat-expandable particle and a skin material by heating and compressing inhibits the expandability (expansion in a later step) of the heat-expandable particle in the stampable sheet or heat-expandable particle I was worried that it could damage itself. However, during intensive research, the stampable sheet and the skin material were heated and compressed with a hot press machine. At this time, if the conditions for heating and compressing with a hot press machine (predetermined temperature and predetermined pressure for a predetermined period of time) are set appropriately, the expandable particles remain unexpanded without damaging the expandable particles. The heat-expandable particles in the stampable sheet could be expanded at the heating temperature of the hot press machine when the hot press machine was released. That is, when heated and compressed under appropriate heating and compression conditions, the two are bonded together, and when the compressed state is released, the heat-expandable particles expand at this heating temperature and the stampable sheet becomes an expanded sheet. It was found that the alignment was maintained.

As a factor that brings about the above-mentioned good results, the surface area of the thermoplastic resin is crushed by crushing the thermoplastic resin welding the reinforcing fibers in the stampable sheet when the stampable sheet is overlaid with heat and compressed. The contact area between the reinforcing fiber and the thermoplastic resin increases, and even if the heat-expandable particles are expanded later, the stampable sheet (expanded sheet) and the skin material are not peeled off, and the sticking between them is not performed. It can be said that the alignment state can be maintained .

Specifically, the invention of claim 1 of the present invention provides a stampable sheet containing a thermoplastic resin, reinforcing fibers and heat-expandable particles in a dispersed manner , and a foamed urethane layer and the foamed urethane are provided on the stampable sheet. Rutotomoni repeated skin material consisting of knit bonded to the surface side of the layer, between the urethane foam layer of the surface and said surface skin material on the side where the skin material is superposed in the stampable sheet, spunbonded-sheath structure Place a non-woven resin sheet so that the skin material is stacked on the resin sheet , then heat-compress with a flat plate hot press to press the skin material onto the stampable sheet surface. after producing the lamination member surface material is attached to the seat, open the hot press, inflating the thermal expandable particles of the stamper in Bull sheet of heated lamination member Forming a predetermined thickness of the expansion lamination member, thereafter, characterized by forming the interior member of the expansion laminated member was pressure molded placed in a cold press car.

According to a second aspect of the present invention, in the method for molding an interior member for a vehicle according to the first aspect, the core material of the core-sheath structure is made of PET resin, and the sheath part of the core-sheath structure is made of an olefin resin. And

According to a third aspect of the present invention, in the method for molding an interior member of an automobile according to the first or second aspect , in the hot press machine, the stampable sheet and the skin material are heated at 160 to 210 ° C., and the thickness of the stampable sheet Now, it is characterized in that it is compressed 0.9 times or less compared with that before being compressed and held for 5 to 30 seconds.

According to the invention of claim 1, a lightweight automotive interior member having the rigidity of the interior member and the adhesion between the stampable sheet and the skin material can be easily obtained . Moreover, the interior member excellent in design property can be obtained, without producing uneven | corrugated avatar phenomenon in a skin material.

According to invention of Claim 2 , the interior member excellent in the adhesiveness of a skin material and a base material can be obtained.

According to invention of Claim 3 , the lightweight automotive interior member which exhibited effectively the rigidity of an interior member and the adhesiveness of a stampable sheet | seat and a skin material can be obtained easily.

It is a figure which shows typically the state which concerns on embodiment of this invention and put the stampable sheet | seat and the skin material on the hot press machine. It is a figure which shows typically the state which concerns on embodiment of this invention and heats and compresses with a hot press machine and manufactures the bonding member. FIG. 3 is a diagram schematically illustrating a state where the hot-press machine is opened and the heat-expandable particles in the stampable sheet are expanded to form an expansion bonding member, which is a post-process of FIG. 2. It is a post process of FIG. 3, Comprising: It is a figure which shows the state which press-molds an expansion | swelling bonding member with a cold press machine. It is a figure which shows the state which is related with embodiment of this invention, and is the state which laminated | stacked the skin material on the base material of a stampable sheet | seat, and is not heat-compressed. The enlarged view which concerns on embodiment of this invention and roughly illustrates the distribution state of the thermoplastic resin in the stampable sheet before heat-pressing with a hot press machine, a reinforced fiber, and a heat-expandable particle is shown. The enlarged view which concerns on embodiment of this invention and roughly demonstrates the distribution state of the thermoplastic resin in a stampable sheet when it heat-compresses with a hot press machine, a reinforced fiber, and a heat-expandable particle is shown. In Example 1 of this invention, it is a figure which shows typically the lamination | stacking state of a base material and a skin material. About Example 1 of this invention, the schematic diagram of the cross section for demonstrating the core-sheath structure of the spun bond nonwoven fabric provided between the stampable sheet of a base material and a skin material is shown. Reference Example, Examples and Comparative Examples of the present invention, is a graph showing the relationship between sound absorption coefficient and frequency of the test piece.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  1 to 9 relate to the embodiment of the present invention, and FIG. 1 to FIG. 4 are diagrams schematically showing each step of the manufacturing process of the interior member. Fig. 1 shows a state in which a stampable sheet and a skin material are placed on a hot press machine, Fig. 2 shows a state in which a bonded member is produced by heating and compression with a hot press machine, and Fig. 3 shows that the hot press machine is then opened. And the state which expand | swells the heat-expandable particle | grain in a stampable sheet | seat and manufactured the expansion | swelling bonding member, FIG. 4 is a figure which shows the state which press-molds an expansion | swelling bonding member with a cold press machine. FIG. 5 is a diagram schematically showing a state in which a skin material is stacked on a base material of a stampable sheet and is not heated and compressed.

First, a web according to the present invention, a stampable sheet, a pasting member formed by pasting a skin material on a stampable sheet, an inflating pasting member obtained by inflating the pasting member , and an interior member obtained by molding the inflating pasting member Will be described.

  Briefly, the web of the present invention consists of reinforcing fibers, a thermoplastic resin and heat-expandable particles, and is manufactured by a papermaking method. This web is heated, pressurized, and cooled to obtain a flat stampable sheet. This stampable sheet has a structure in which a thermoplastic resin melted and solidified by heating and cooling constitutes a matrix, and reinforcing fibers and heat-expandable particles (unexpanded state) are dispersed therein. In the present invention, as shown in FIG. 1, a skin material 2 having a design property is placed on the stampable sheet 1 so as to overlap. The laminated structure of stampable sheets will be described later.

  And as shown in FIG. 2, the stampable sheet 1 and the skin material 2 are heat-compressed with the hot press machine 21, and the flat bonding member 3 in which both were bonded together is formed. The heat-expandable particles in the bonding member 3 expand at the heating temperature of the hot press machine 21 to form the expansion bonding member 4 (see FIG. 3). And the vehicle interior member is obtained by press-molding the expansion bonding member 4 in a predetermined shape with the cold press machine 22 (refer FIG. 4).

  Next, the web of the present invention, the stampable sheet, the reinforcing fiber in the stampable sheet, the thermoplastic resin, and the heat-expandable particles will be described. In particular, the adhesion state of the reinforcing fibers, the thermoplastic resin, and the heat-expandable particles will be described with reference to FIGS.

  FIG. 6 schematically shows a dispersion state of the reinforcing fibers, the thermoplastic resin, and the heat-expandable particles when the stampable sheet 1 is manufactured. 31 indicates a rod-like reinforcing fiber, 32 indicates a thermoplastic resin that bonds the reinforcing fibers 31 to each other, and 33 indicates spherical heat-expandable particles (unexpanded state) dispersed between the reinforcing fibers 31. . FIG. 7 schematically shows a dispersion state of the reinforcing fibers 31, the thermoplastic resin 32, and the heat-expandable particles 33 when heated and compressed by a hot press machine. The reinforcing fibers 31 and the heat-expandable particles (unexpanded state) 33 are hardly changed, but the thermoplastic resin 32 is crushed and the surface area is enlarged. Thereby, the area where the reinforcing fibers 31 are bonded to each other with the thermoplastic resin 32 is increased, and the adhesive strength is increased. This adhesive strength will be described in detail later.

  As the reinforcing fiber used in the present invention, either an inorganic fiber or an organic fiber may be used, and a fiber obtained by combining or mixing these may be used. Usable fibers include, for example, glass fibers, carbon fibers, boron fibers, stainless steel fibers and other metal fibers and mineral fibers as inorganic fibers, and aramid fibers, polyester fibers, polyamide fibers as organic fibers. And natural fibers such as hemp. Moreover, you may use combining these 1 type (s) or 2 or more types. In addition, from the viewpoint of imparting a high reinforcing effect to the interior member, inorganic fibers are preferable to organic fibers. Among them, carbon fibers are preferably used when emphasizing strength. On the other hand, from the viewpoint of cost, it is preferable to use glass fiber, and from the viewpoint of thermal recycling that no residue remains even if incinerated, organic fiber is preferable.

The average diameter of the reinforcing fiber is preferably 3 to 50 μm from the viewpoint of sufficiently securing the reinforcing effect and the expandability of the stampable sheet. More preferably, it is φ3 to 30 μm. By using the reinforcing fibers having an average diameter in the above range, the yield of the heat-expandable particles during papermaking can be improved. In addition, when expecting an increase in the expansion amount due to the synergistic effect of the spring back of the reinforcing fiber and the expandability of the heat-expandable particles, the average plays a role of filling the space between the reinforcing fiber having an average diameter of φ100 to 1000 μm. A mixture of reinforcing fibers having a diameter of 3 to 50 μm may be used. Moreover, it is preferable that the average length of a reinforced fiber is a thing of the range of 3-100 mm from a viewpoint of ensuring a sufficient reinforcement effect, expansibility, and a moldability. In addition, from the viewpoint of more uniformly dispersing the thermoplastic resin and the reinforcing fiber in the previous stage of the paper making process, the average length of the reinforcing fiber is more preferably in the range of 3 to 50 mm. The average diameter and average length are values obtained by measuring the diameter and length of reinforcing fibers or webs, stampable sheets , and interior member reinforcing fibers before use, about 50 using a microscope or the like. It is average. The reinforcing fiber may be observed using a microscope after firing the web, stampable sheet , and interior member at a temperature of about 600 ° C.

  The reinforcing fiber used in the present invention is preferably subjected to surface treatment with a coupling agent or a sizing agent. In particular, in order to improve the wettability and adhesiveness between the reinforcing fiber and the thermoplastic resin, it is preferable to perform a treatment with a silane coupling agent. As the silane coupling agent, a vinyl silane, amino silane, epoxy silane, methacryl silane, chloro silane, mercapto silane, or the like can be used. The surface treatment of the reinforcing fiber with the silane coupling agent can be performed by a known method such as a method of spraying the silane coupling agent solution while stirring the reinforcing fiber or a method of immersing the reinforcing fiber in the coupling agent solution. it can. In addition, it is preferable that the processing amount of the said silane coupling agent is 0.001-0.3 mass% with respect to the mass of the reinforced fiber to process. If it is less than 0.001 mass%, the effect of the silane coupling agent is small, and sufficient adhesive strength between the reinforcing fiber and the thermoplastic resin cannot be obtained. On the other hand, if it exceeds 0.3 mass%, the effect of the silane coupling agent is saturated. Because it does. More preferably, it is the range of 0.005-0.2 mass%.

  The reinforcing fiber used in the present invention is desirably fibrillated into a single fiber in order to increase the strength and expansibility of the stampable sheet. For this purpose, the reinforcing fiber is dispersed with a water-soluble sizing agent. It is preferable to process. As the sizing agent, a polyethylene oxide-based or polyvinyl alcohol-based water-soluble resin can be used. The treatment amount of the sizing agent is 2 mass% or less, preferably 1 mass% or less with respect to the mass of the reinforcing fiber to be treated. This is because if it exceeds 2 mass%, it becomes difficult to disentangle the fibers in the papermaking process. In addition, the minimum of processing amount is about 0.05 mass%. If the amount of processing is too small, the handling properties will deteriorate.

  Next, the thermoplastic resin used in the present invention will be described.

  Examples of the thermoplastic resin used in the present invention include polyolefin resins such as polyethylene and polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polyamide, polyacetal, or ethylene-vinyl chloride copolymer, ethylene-vinyl acetate. A copolymer, a styrene-butadiene-acrylonitrile copolymer, a thermoplastic elastomer such as EPM, EPDM, or the like can be used alone or in combination. Among these, polyolefin resins such as polyethylene and polypropylene are preferable because they are excellent in strength, rigidity, and moldability. In particular, polypropylene is more preferable because it has an excellent balance of these properties and is inexpensive. Further, among polypropylenes, those having an MFR (melt flow rate, however, 230 ° C., 21.17 N) measured under the conditions defined in JIS K 6921-2: 1997 are in the range of 1 to 200 g / 10 min. The thing of the range of 10-150 g / 10min is more preferable.

  Furthermore, in order to improve the adhesion between the thermoplastic resin and the reinforcing fiber, the thermoplastic resin is modified with various compounds such as acids such as unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides and epoxy compounds. It can be used in combination with an unmodified thermoplastic resin. The modification treatment can be performed, for example, by graft copolymerizing polypropylene with maleic acid, maleic anhydride, acrylic acid, or the like. As the modified product, one having a modified group such as an acid anhydride group or a carboxyl group in the molecule is particularly preferable from the viewpoint of improving the strength.

  The thermoplastic resin may be in the form of particles such as powder, pellets, flakes, or fibers. From the viewpoint of improving the handling property of the web and the yield of the heat-expandable particles, and from the viewpoint of sufficiently entangled the molten thermoplastic resin and the reinforcing fiber when producing the stampable sheet, It is preferable to use a fibrous material together with a particulate material. Here, when using a particulate thing, it is preferable to use an average particle diameter of (phi) 100-2000 micrometers, and the viewpoint of uniformly disperse | distributing in a stampable sheet has more preferable (phi) 100-1000 micrometers. On the other hand, when using a fibrous thing together, it is preferable to use an average diameter of φ1 to 50 μm and an average length of 1 to 50 mm. From the viewpoint of uniform dispersion in the foam liquid, the average length is The thing of 1-30 mm is more preferable.

  Next, the heat-expandable particles used in the present invention will be described.

  The heat-expandable particles used in the present invention have a characteristic that when heated above a certain temperature, the softened shell expands due to the vaporizing and expanding pressure of the core. The present invention has a great feature in that the heat-expandable particles are used as a material constituting the web, the stampable sheet, and the expansion bonding member thereof. By using these heat-expandable particles, a larger expansion amount can be ensured than in the case of the springback action of the reinforcing fiber alone, so that the density can be further reduced, and a lightweight and rigid expansion bonded member is obtained. be able to.

  In the present invention, known particles can be used as the heat-expandable particles. Particularly, the core-shell type heat-expandable particles in which the core is a liquid hydrocarbon and is encapsulated by a shell made of a thermoplastic resin having gas barrier properties. Is preferred. Usually, hydrocarbons used in the core have a boiling point lower than the softening point of the thermoplastic resin of the shell. For example, hydrocarbons and ethers having a boiling point of 150 ° C. or less such as isobutane, pentane, and hexane are used. Can be mentioned. Examples of the thermoplastic resin that forms the shell include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polystyrene, polyvinyl chloride, polyvinylidene chloride, methacrylic resin, ABS resin, and ethylene-vinyl acetate. Known thermoplastic resins such as copolymers, polyamide resins, polyethylene terephthalate, polybutylene terephthalate, polyurethane, polyacetal, polyphenylene sulfide, and fluororesin can be exemplified. Particularly preferred is a heat-expandable particle having a core made of a liquid hydrocarbon such as isobutane, pentane or hexane and a shell made of a thermoplastic resin such as acrylonitrile copolymer or polyvinylidene chloride.

  The average diameter of the heat-expandable particles is preferably φ5 to 200 μm before heat expansion, more preferably φ10 μm or more and less than φ100 μm, and still more preferably φ20 μm or more and φ100 μm or less. When the particle diameter before expansion is less than φ5 μm, it passes through the gaps between the reinforcing fibers at the time of papermaking and easily drops off, resulting in a decrease in yield. On the other hand, if it exceeds φ200 μm, the size of the heat-expandable particles after expansion is too large, the thickness of the expansion molded product becomes non-uniform, or the surface quality is deteriorated. The heat-expandable particles preferably have an average diameter of φ10 to 2000 μm when expanded, and more preferably φ20 to 1000 μm. If the average diameter of the heat-expandable particles after expansion is too small, the amount (number) of heat-expandable particles necessary for expanding the stampable sheet becomes large. On the other hand, if the average diameter after expansion is too large, irregularities are generated on the surface of the expansion molded product, which deteriorates the surface properties. The average diameter of the heat-expandable particles after expansion is a value obtained by observing about 50 heat-expandable particles in the expansion-molded product with an optical microscope or the like and averaging the measured diameters.

  As described above, when the heat-expandable particles are heated above a certain temperature, the softened shell starts to expand due to the pressure at which the core vaporizes and expands. In the present invention, this temperature is referred to as an expansion start temperature, and is defined as a temperature at which the particle diameter of the heat-expandable particles starts to increase rapidly when the heat-expandable particles are heated at 10 ° C./min. The heat-expandable particles used in the present invention preferably have an expansion start temperature of 120 ° C. or higher, more preferably 130 to 230 ° C. When the expansion start temperature is less than 120 ° C., the heat-expandable particles themselves are inferior in heat resistance, and it is necessary to extremely lower the drying temperature of the paper-made web. On the other hand, when the expansion start temperature exceeds 230 ° C., the heating temperature for expansion becomes too high, which may cause deterioration of the thermoplastic resin.

  The expansion start temperature of the heat-expandable particles preferably has a smaller difference from the melting point of the thermoplastic resin constituting the matrix. If the expansion start temperature of the heat-expandable particles is too lower than the melting point of the thermoplastic resin, the thermoplastic resin will melt and flow around the reinforcing fibers, and the heat-expandable particles will expand too much before adhering. It is not preferable. On the other hand, if the expansion start temperature is too high, it is necessary to heat to a high temperature in order to obtain a sufficient expansion thickness, which may deteriorate the thermoplastic resin. Therefore, the difference between the expansion start temperature of the heat-expandable particles and the melting point of the thermoplastic resin constituting the matrix is preferably within ± 30 ° C.

  Further, the heat-expandable particles preferably have a maximum expansion temperature higher than the melting point of the thermoplastic resin, and the temperature difference is more preferably within 50 ° C. Here, the maximum expansion temperature is a temperature at which the particle diameter of the heat-expandable particles becomes maximum when the heat-expandable particles are heated at 10 ° C./min. This is because if the maximum expansion temperature is too higher than the melting point of the thermoplastic resin, it is necessary to heat to a high temperature in order to obtain sufficient expansion property, which may deteriorate the thermoplastic resin.

  Next, the basis weight of the web of the present invention and the blending ratio of the web, the stampable sheet, the reinforcing fibers constituting the interior member, the thermoplastic resin, and the heat-expandable particles will be described.

First, the basis weight of the web of the present invention is preferably in the range of 100 to 1000 g / m ² . If the weight per unit area of the web is less than 100 g / m ² , sufficient thickness cannot be obtained when the interior member is used, and the rigidity decreases. On the other hand, if it exceeds 1000 g / m ² , the weight of the expansion molded product is reduced. This is because it becomes difficult. A more preferable basis weight is in the range of 100 to 700 g / m ² , and more preferably 100 to 500 g / m ² .

  Next, the blending ratio of the reinforcing fiber and the thermoplastic resin constituting the web of the present invention varies depending on the specific gravity of the reinforcing fiber and the thermoplastic resin used and the content of other additives and colorants, but the bending strength In order to obtain an interior member having high mechanical strength such as (buckling strength) and flexural modulus (elastic gradient), the reinforcing fiber / thermoplastic resin is in the range of 3/97 to 60/40 by mass ratio. Is preferred.

  Moreover, it is preferable that content of the heat | fever expansible particle which comprises the web of this invention is 1-40 mass parts with respect to a total of 100 mass parts of a reinforced fiber and a thermoplastic resin. If the amount is less than 1 part by mass, the effect of improving the expansibility does not appear. On the other hand, if the amount exceeds 40 parts by weight, the effect of improving the expansibility becomes too large, and not only the interior member but also the surface layer is reduced in density. Stiffness and buckling resistance are reduced.

  The web of the present invention includes an antioxidant, a light stabilizer, a metal deactivator, a flame retardant, carbon black, a VOC adsorbent, in addition to the above-described thermoplastic resin, reinforcing fiber, and heat-expandable particles. Additives such as a VOC decomposing agent and a deodorant, a colorant, an organic binder and the like can be contained as required. Further, the above additives and colorants may be contained by, for example, pre-coating on reinforcing fibers or thermoplastic resin, blending at the time of mixing, or spraying and adding to the web. .

  The skin material of the present invention is intended for decoration and protection, and is a woven or non-woven fabric made of natural fibers such as plant fibers and animal fibers, cellulose acetate-based, polyamide-based, polyester-based, polyacrylic, and polypropylene-based synthetic fibers. Is preferred. The fiber-based skin material has a large anchor effect in which the thermoplastic resin layer as an adhesive melts and bites between the fibers of the skin material, and the adhesive strength increases. Also, if adhesion with a thermoplastic resin as an adhesive can be obtained, a foam sheet having open cells, such as polyurethane foam, may be provided on the surface to be bonded to the woven or non-woven core material. It is also possible to absorb the irregularities of the core material, enhance the design of the surface of the skin material, and impart cushioning properties. For example, a skin material obtained by bonding a knit to a foamed urethane sheet can be used.

  Next, a method for producing the web, stampable sheet and interior member according to the present invention will be described.

  The method for producing a web according to the present invention is produced by producing a foam liquid in which reinforcing fibers, a thermoplastic resin, and heat-expandable particles are dispersed in a surfactant-containing aqueous medium containing microbubbles as a dispersion liquid. . You may disperse | distribute and mix the said raw material not in foaming liquid but in the water which does not contain a thickener or a flocculant. Note that the use of foam liquid retains the reinforcing fibers, thermoplastic resin, and heat-expandable particles on the surface of the foam and disperses them uniformly in the foam liquid, so that separation does not occur during the transportation of the dispersion liquid. Have. In the production of the web in the present invention, a dispersion liquid (foam liquid) containing reinforcing fibers, a thermoplastic resin, and heat-expandable particles is poured onto a porous support such as a papermaking screen and sucked from below the porous support. And then defoaming and depositing the solid content in the dispersion on the porous support.

  Any of anionic, nonionic, and cationic surfactants may be used as the surfactant used in the foam making method. Particularly, sodium dodecyl benzene sulfonate, palm oil fatty acid diethanolamide, and the like are excellent in terms of the effect of uniformly dispersing the raw materials mainly composed of reinforcing fibers and thermoplastic resin in the medium. Can be used.

  The web obtained by foaming is dried under conditions (temperature and time) in which the heat-expandable particles do not expand at the maximum. That is, if the heat-expandable particles in the web are maximally expanded in the drying stage, not only the handling property of the web is lowered, but also the heat-expandable particles are crushed during compression when manufacturing a stampable sheet. For this reason, the expandability of the stampable sheet when manufacturing the interior member is sometimes insufficient.

  A certain amount of heat is required for maximum expansion of the heat-expandable particles. Therefore, in order to prevent the heat-expandable particles from expanding to the maximum, it is necessary to control the heating temperature and time so that the amount of heat input during drying is less than the certain amount of heat. Specifically, the heating temperature for drying is set to 30 ° C. or less from the maximum expansion temperature, and the heating time is {2 × (maximum expansion temperature−expansion start temperature)} when the heating temperature is the maximum expansion temperature or less. When the heating temperature is higher than the maximum expansion temperature, it should be within {300 / (heating temperature−maximum expansion temperature)} minutes and within {2 × (maximum expansion temperature−expansion start temperature)} minutes. preferable.

  In addition, when the web obtained by foaming was coated with an emulsion or aqueous solution containing an organic binder by spray spraying or a roll coater and impregnated by vacuum suction or the like from the opposite side, the web was dried. Occasionally, reinforcing fibers, thermoplastic resins, and heat-expandable particles adhere efficiently, which not only improves yield, but also improves handling and production efficiency, which is preferable.

  Next, the manufacturing method of the flat stampable sheet of this invention is demonstrated.

  The stampable sheet of the present invention heats and presses the web obtained by foaming under the conditions (temperature and time) above the softening point or melting point of the thermoplastic resin and under which the heat-expandable particles do not undergo maximum expansion. Then, by cooling and solidifying, the thermoplastic resin is melted to form a matrix, and the dispersed reinforcing fibers and the heat-expandable particles are sufficiently bonded and bonded by the melted and solidified thermoplastic resin. To do. Here, the conditions (temperature and time) at which the maximum expansion is not performed are the same as those described above. The reason why the melting point of the thermoplastic resin is equal to or higher than the melting point is that if the melting point is lower than the melting point, the thermoplastic resin is not sufficiently fused to the reinforcing fibers and the heat-expandable particles, and the necessary strength cannot be obtained. The reason why the particles are heated under the condition that the maximum expansion is not achieved is that if the heat-expandable particles are expanded at the maximum in this heating process, not only the handling property of the stampable sheet is lowered but also the compression during the production of the stampable sheet is performed. This is because the heat-expandable particles are crushed and the expandability necessary for the subsequent production of the expansion-molded product may not be obtained.

  It is preferable to compress the stampable sheet so that the specific gravity of the stampable sheet is 0.3 or more as a pressurizing condition when the stampable sheet is manufactured by heating the web and melting the thermoplastic resin and then pressurizing. If it is less than 0.3, the flowability of the thermoplastic resin is insufficient, and a structure in which reinforcing fibers and heat-expandable particles are dispersed in the thermoplastic resin as a matrix cannot be formed. More preferably, the specific gravity is 0.4 or more. However, if compressed too much, the reinforcing fibers may be broken or the sheet weight may be reduced (the sheet area increases and the thickness decreases). preferable.

  In the stampable sheet manufacturing method of the present invention, the web may be pressed after the thermoplastic resin is melted, or may be heated and pressed simultaneously. The pressurizing method includes a batch type intermittent press method, a continuous press method using a Teflon (registered trademark) or steel belt, a roll press method, and the like, and any method may be used. In order to improve the handleability of the stampable sheet, it may be pressurized while the thermoplastic resin is melted, then unloaded and expanded, and cooled in a thicker state than when pressurized. Furthermore, the method of simultaneously drying and heating the web, followed by pressurization is efficient in production and economical.

To adhere the table surface material more strongly to the stampable sheet, stampable sheet between the skin material, a few tens of microns thick of the resin sheet (invention consisting heat-fusible resin, the following in referred to as resin sheet contains a nonwoven fabric sheet) is interposed.

This resin sheet penetrates the stampable sheet side to form an impregnated adhesive layer having a sufficient thickness on the surface side of the stampable sheet, and its anchor effect is responsible for improving the adhesion between the stampable sheet and the skin material. It is a resin sheet, and is made of a resin having the same or similar structure as the thermoplastic resin in the stampable sheet and having a melting point or a melt viscosity that is equal to or higher than that of the thermoplastic resin. Is preferred .

As the nonwoven fabric sheet, spunbonded nonwoven fabric of Japanese to core-sheath structure is used (see FIGS. 8 and 9). In this case, the core material of the core-sheath structure is preferably a material such as PET that is not melted by heat during heating. The sheath part of the core-sheath structure is preferably melted by heat at the time of heating, and a polyolefin resin such as a polypropylene resin or a polyethylene resin is suitable. In particular, the sheath portion is preferably a polypropylene resin having good compatibility with the base material polypropylene resin.

Particularly, in the case of two-layer structure of urethane foam and knit as the skin material, to use a spunbonded nonwoven fabric of the core-sheath structure. That is, in the case of a resin film made of a heat-fusible resin, since the heat-fusible resin is melted by heat at the time of heating and soaks into the foamed urethane layer of the skin material, the difference in the state of soaking after molding, etc. Accordingly, fine unevenness, a so-called avatar phenomenon may occur in the skin layer, which may impair the design of the surface. Therefore, when a two-layer structure of urethane foam and knit is used as the skin material, it is preferable to use a non-woven sheet made of a spunbond non-woven fabric having a core-sheath structure instead of a resin film as the heat-fusible resin. . If it is a spunbond nonwoven fabric of this core-sheath structure, the sheath part of the core-sheath structure melts at the heating temperature at the time of molding and soaks into the foamed urethane layer, but the core material maintains its shape without being melted. It seems that the avatar phenomenon like this can be prevented .

  Further, the interior member of the present invention has a high density on the surface side of the interior member where the skin material is not bonded in order to further improve strength characteristics such as buckling resistance and rigidity, sound absorption characteristics and air permeability. A resin layer may be formed. The high-density resin layer is a resin layer having a lower porosity or no void than the inner layer portion of the expansion molded product. This high-density resin layer is composed of a base material and other high-density resin layers. Adhesiveness is also required. Conventionally known techniques can be used as a method for forming the high-density resin layer. For example, a method of impregnating one surface of a web or a stampable sheet with a liquid containing a resin that forms a high-density resin layer, a method of extruding and laminating a molten high-density resin into a sheet shape, A method of laminating and forming resin sheets is suitable. Among these, the method of laminating the high-density resin sheet is preferable because it can be easily laminated on either the web or the stampable sheet. The thickness of the high density resin sheet is preferably 200 μm or less, more preferably 20 to 150 μm, in order to suppress an increase in weight. Here, the high-density resin sheet may be a sheet made of polypropylene, nylon, linear polyethylene, or the like, or a multilayer film in which they are stacked in two or more layers. The high-density resin sheet may be provided with a through hole with a needle punch or a slit in order to obtain sound absorption.

FIG. 5 shows a form in which a resin sheet 5 made of a heat-fusible resin is laminated on both surfaces of the stampable sheet 1 and a high-density resin layer is provided on one surface side of the resin sheet 5. That is, a form in which the skin material 2 is laminated on one surface of the resin sheet 5 and the polyamide resin 6 and the spunbond nonwoven fabric 7 are laminated in this order on the other surface is shown. In FIG. 5, these high-density resin layers are laminated, but this is not always necessary, and at least one of the high-density resin layers can be omitted.

  Hereinafter, a simple stampable sheet alone, a sheet in which a resin sheet made of a heat-fusible resin is laminated on both sides of this simple substance, and a sheet provided with a high-density resin layer on the other side are referred to as a base material 8. ing.

  Next, the manufacturing method of the interior member according to the present invention will be described.

  As shown in FIGS. 1 and 2, the interior member of the present invention first superimposes the skin material 2 on the substrate surface of the flat stampable sheet 1 produced as described above. In this state, the hot press machine 21 is heated and compressed under predetermined conditions. In this heating / compression process, the thermoplastic resin in the stampable sheet 1 is crushed to increase the surface area, increase the contact area with the reinforcing fiber, and enhance the adhesive force between the reinforcing fiber and the thermoplastic resin. . At the same time, the skin material 2 is brought into close contact with the stampable sheet 1 and bonded thereto to produce the bonding member 3. After that, as shown in FIG. 3, the hot press machine 21 is quickly opened to a predetermined interval, and the heat-expandable particles in the stampable sheet 1 are expanded at the heating temperature of the hot press machine 21. Thereby, the expansion bonding member 4 is manufactured. Then, as shown in FIG. 4, the expansion | swelling bonding member 4 is pressure-molded with the cold press machine 22, and the interior member for vehicles is shape | molded.

  In this manufacturing method, the heating and compression conditions of the hot press machine will be described.

  The heating temperature condition is that the thermoplastic resin in the stampable sheet must be heated to a temperature equal to or higher than the softening temperature or melting point of the thermoplastic resin and the expansion start temperature of the heat-expandable particles to soften or melt the thermoplastic resin. If it is too low, the thermoplastic resin in the stampable sheet will be insufficiently softened or melted, and the adhesive strength between the stampable sheet and the skin material will be insufficient. Further, the stampable sheet is not sufficiently heated, and the heat-expandable particles are not expanded as expected. On the other hand, when the heating temperature is too high, the thermoplastic resin in the stampable sheet is excessively melted, the movement from the reinforcing fibers becomes large, and the bonding force between the reinforcing fibers becomes insufficient. Moreover, the possibility of impairing the design of the surface of the skin material increases, which is not preferable.

  On the other hand, if the heating temperature is too high, the stampable sheet is overheated and the heat-expandable particles are damaged. Therefore, it is preferable that the heating temperature of a hot press shall be 160-210 degreeC. Depending on the type of the skin material, a slight difference may be provided between the mold temperature on the skin material side and the mold temperature on the back surface side of the base material. That is, the mold temperature on the front surface side may be lowered by 20 to 30 ° C. compared to the temperature on the back surface side of the substrate.

When the base material is compressed too much in the hot press machine, the heat-expandable particles are crushed too much, and the expansibility necessary for the subsequent production of the expansion bonded member cannot be obtained. In addition, the thermoplastic resin that bonds the reinforcing fibers in the stampable sheet may move too much and the adhesive strength with the reinforcing fibers may be insufficient. Conversely, if the base material is not sufficiently compressed, the thermoplastic resin cannot be crushed and the surface area cannot be sufficiently increased, and the contact area with the reinforcing fibers cannot be increased. As a result, the adhesive strength between the reinforcing fiber and the thermoplastic resin cannot be sufficiently secured, and the rigidity is insufficient. Therefore, it is preferable to control the stampable sheet so that the thickness of the stampable sheet is compressed to 0.9 times or less compared with that before compression. Furthermore, it is preferable to compress 0.8 to 0.3 times. Here, the thickness of the stampable sheet is that the usable skin material is non-woven fabric, woven fabric, knitted fabric, etc., and there are single layer or multilayered layers. It varies considerably. Therefore, when heated and compressed with a hot press machine in the present invention, the thickness of the skin material is considerably different in shrinkage and specific gravity. Therefore, it was determined that it is preferable to specify the thickness only with the stampable sheet, and as described above, the thickness was specified only with the stampable sheet.

  From another viewpoint, if the specific gravity of the base material (stampable sheet) is about 0.6 to 0.7, the specific gravity of the base material (stampable sheet) is about It is preferable to control the compressive force so that the specific gravity is 0.8 to 1.2. Furthermore, when the specific gravity is 0.6, 0.8 / 0.6≈1.33 so that it becomes 0.8, and when the specific gravity is 0.7, it becomes 1.2. Thus, it is preferable to increase the compression ratio as the thickness increases so that 1.2 / 0.7≈1.71. When compared by the ratio of specific gravity of the base material before compression and after compression (before expansion), it is preferably in the range of 1.05 to 2.5, particularly 1.2 to 2.0.

  In addition, if the thickness of the substrate is 2.0 to 3.5 mm and the thickness of the skin material is 0.5 to 1.5 mm, the total thickness is 1.3 to 4.0 mm. It is preferable to compress to about 1.7 to 2.5 mm. In terms of the compression rate, it is preferable to set it to 40 to 80%, preferably 50 to 70%. For example, if the thickness of the base material is 0.6 to 1.0 mm and the skin material is a non-woven fabric and the thickness is 1.0 to 2.0 mm, about 1.3 to 2.0 mm It is preferable to compress it. For example, if the thickness of the substrate is 0.6 to 1.0 mm and the skin material is made of knit and the thickness is 2.0 to 4.0 mm, the thickness is 1.2 to 2.0 mm. It is preferable to compress to the extent.

  However, in actual hot press machine work management, it is easy to determine and manage the hot press machine interval rather than specific gravity and compression ratio, and such management is often performed. For example, when the stampable sheet is 2.5 mm, the skin material is 1.0 mm, and the total is 3.5 mm, the interval when pressurizing with a hot press machine is set so that the total is 2.3 mm. The stampable sheet is 0.7 mm, the skin material is 1.2 mm, the total is 1.9 mm, the total is 1.6 mm, the interval when pressing with a hot press machine is set, etc. For each thickness, it is easy to manage to obtain an appropriate thickness empirically and to control the thickness during pressing.

  The compression time varies slightly depending on the composition and thickness of the material, but if the time is too long, the molten thermoplastic resin in the base material oozes out, and the design of the surface of the skin material is impaired. If the time is too short, the thermoplastic resin is insufficiently softened and melted, resulting in poor adhesion. Therefore, the compression time is preferably 5 to 30 seconds, particularly 7 to 15 seconds.

  In the present invention, it is heated and compressed by a hot press machine, and the thermoplastic resin in the stampable sheet is crushed to increase the surface area to increase the bonding force between the reinforcing fibers, and the skin material and the stampable sheet are strongly bonded. After the contact, the stampable sheet is heated at this heating temperature to expand the heat-expandable particles in the stampable sheet. In this way, with a hot press machine, the stampable sheet and the skin material are stacked and heated and compressed, thereby crushing the thermoplastic resin in the stampable sheet and expanding the surface area to increase the bonding strength between the reinforcing fibers. At the same time, the surface material and the stampable sheet can be strongly adhered to each other, and the entire stampable sheet can be heated with a hot press machine. Heated uniformly and in a short time, the heat-expandable particles can be uniformly expanded and dispersed.

In the interior member molded in this way, when a resin film is used as a resin sheet made of heat-fusible resin on both sides, the resin sheet melts when heated and compressed by a hot press machine. Therefore, when it is finally used as an interior material by a cold press machine, there is a possibility that it is not an independent layer that can be clearly distinguished from a base material or a skin material. When a spunbond nonwoven fabric with a core-sheath structure is used as the resin sheet, the core material remains between the skin material and the base material. Is often found to exist.

  In addition, you may form a wrinkle pattern in the surface of the hot press machine which skin material contacts. In this case, it has the effect of making the skin material fall inconspicuous and maintaining the design of the skin material.

  The present invention will be specifically described below based on examples.

(Reference Example 1)
Stampable sheet Thermoplastic resin: Polypropylene particles (weight average molecular weight 200,000, MFR 65 g / 10 min, average particle diameter φ500 μm, melting point 165 ° C.)
Reinforcing fiber: Glass fiber (length 25 mm, average diameter 13 μm)
Heat-expandable particles: core hydrocarbon
Shell part Acrylic nitrile copolymer
Average particle diameter φ70μm
Expansion start temperature 155 ° C
Maximum expansion temperature 176 ° C
Skin material Polyester organic fiber nonwoven fabric (thickness 1.2mm)
Resin sheet (resin film)
40 μm thick polypropylene (MFR65, melting point 160 ° C.)
Polyamide fiber 25-μm thick 6-nylon (melting point 215 ° C)
Spunbond Polyester fiber spunbond (weight per unit area 13g / m ² , thickness 0.08mm)
As a dispersion, 0.5 g / L of sodium dodecylbenzenesulfonate, which is a surfactant, is added to 1.5 liters of water and stirred to prepare a foam containing fine bubbles. In this foam, Raw materials having an ingredient composition consisting of 40% polypropylene particles and 60% glass fibers were mixed at a dry weight%, and further heat-expandable particles were added and stirred for 10 minutes to be dispersed. Next, this foam liquid was defoamed and dried to prepare a web having a total basis weight of 400 g / m ^{2 of} reinforcing fibers and thermoplastic resin and a basis weight of heat-expandable particles of 30 g / m ² . When the cross section of the web was observed with a microscope, the reinforcing fibers 31, the thermoplastic resin 32, and the heat-expandable particles 33 were dispersed as schematically shown in FIG.

A resin film made of polypropylene (MFR65, melting point 160 ° C.) having a thickness of 40 μm is laminated on both surfaces of the obtained web as a resin sheet, and a polyamide fiber film (6 μm having a thickness of 25 μm) is further formed on the other surface. -Nylon (melting point: 215 ° C)) and polyester fiber spunbond (weighing 13 g / m ² , thickness 0.08 mm) are laminated on the surface, and this laminate is preheated at 210 ° C, and the preheated laminate is 25 It placed between cooling boards at 0 ° C. and pressed at a pressure of 5 kgf / cm ² to obtain a solidified dense papermaking stampable sheet (thickness: 1.0 mm). As shown in FIG. 5, it was set as the base material which piled up another resin layer on this stampable sheet. When a cross-section of this laminate was observed with a microscope, as schematically shown in FIG. 6, the reinforcing fibers 31 were bonded with the particles of the thermoplastic resin 32, and the heat-expandable particles 33 that were not expanded were dispersed. It was.

Next, a polyester organic fiber non-woven fabric (thickness 1.2 mm) was prepared as a skin material, and was laminated on the surface of the resin film of the base material to obtain a 2.2 mm laminate. This laminated body was put into a hot press machine and heated and compressed under the following conditions.
Heating temperature: 200 ° C
Compression amount: 73% (2.2mm → 1.6mm)
Heating time: 10 seconds After heating with a hot press machine, the cross section of this laminate was observed with a microscope. As shown schematically in FIG. 7, the reinforcing fibers 31 were crushed and the thermoplastic resin 32 increased in surface area. Was strongly bonded and exhibited a structure in which the heat-expandable particles 33 that were not expanded were dispersed. Thereafter, as shown in FIG. 3, the clearance of the hot press machine 21 was opened to 30 mm, and the heat-expandable particles were expanded to produce the expansion bonding member 4.

  And as shown in FIG. 4, this expansion bonding member 4 was shape | molded with the cold press machine 22, and the interior member was obtained.

(Reference Example 2)
The only difference from Reference Example 1 is that the glass fiber, which is a reinforcing fiber, has a length of 25 mm and an average diameter of 11 μm, and the subsequent conditions are the same.

(Reference Example 3)
The only difference from Reference Example 1 is that the glass fiber, which is a reinforcing fiber, has a length of 25 mm and an average diameter of 7 μm, and the subsequent conditions are the same.

(Reference Example 4)
1.0mm The thickness of the stampable sheet, the thickness of the knitted skin material and 3.0 mm, only in that the heating and compression to 1.7mm is different from the reference example 1, after the conditions are the same.

(Reference Example 5)
Similar to Reference Example 1 , the glass fiber, which is a reinforcing fiber, has a length of 25 mm and an average diameter of 13 μm. The difference from Reference Example 1 is that the resin sheet is a heat-fusible resin between the stampable sheet and the skin material. The difference is that the skin material is directly stacked on the stampable sheet without any interposition, but the conditions are the same thereafter.

(Example 1 )
Example 1 is an example in which a combination of a skin material and a resin sheet is specified. Specifically, as shown in FIGS. 8 and 9, as a resin sheet, a spunbond nonwoven fabric 501 having a core-sheath structure having a thickness of 30 μm (core material 502: PET resin having a melting point of 260 ° C., sheath portion 503: melting point 110 Is different from the reference example 1 in that a material obtained by bonding urethane foam 203 (thickness: 2.5 mm, density: 40 kg / m ³ ) to the knit 202 is prepared as the skin material 201. . A resin sheet made of the above nonwoven fabric is laminated on the surface side of the stampable sheet to produce a substrate, and the foamed urethane side is aligned with the spunbond nonwoven fabric having a core-sheath structure superimposed on the substrate. The materials were stacked to obtain a 3.5 mm laminate. This laminated body was put into a hot press machine and heated and compressed under the following conditions.
Heating temperature: 180 ° C
Compression amount: (3.5mm → 1.6mm)
After the heating time: 10 seconds, an interior member was produced in the same manner as in Reference Example 1 .

(Comparative Example 1)
As in Reference Example 1 , a substrate having a resin layer provided on both sides of the stampable sheet was prepared. Next, this base material was heated with a far-infrared heater at a heater set temperature of 250 ° C. for 2 minutes to expand the heat-expandable particles to produce a flat plate-like expanded base material. A hot melt adhesive layer was provided on the surface of the expanded base material, and the same skin material as in Reference Example 1 was laminated to obtain a laminate. This laminate was compressed / cooled by a cold press machine with a clearance set to 6.5 mm, and a skin material was applied to the substrate and molded to obtain an interior member.

(Comparative Example 2)
An example in which the basis weight of the base material is increased in order to obtain the same elastic gradient as in Reference Example 1 of the present invention will be shown.

For the interior members obtained in Reference Examples 1 to 5, Example 1 and Comparative Examples 1 and 2, a test piece having a length of 150 mm and a width of 50 mm was prepared, and for this test piece, a span of 100 mm and a crosshead speed of 50 mm / A three-point bending test in which a load was applied under the condition of min was performed, and the elastic gradient was measured. This elastic gradient was performed according to JIS K 7171 at a span of 100 mm and a test speed of 50 mm / min. The results are shown in Table 1. Moreover, the peeling state of the skin material with respect to a base material was test | inspected. In the peeling test, the width of the test piece was 25 mm, and the test piece was peeled off so as to invert 180 ° at a tensile speed of 200 mm / min. The material failure of the skin material means that the skin material is not peeled off from the interface of the base material and the skin material is peeled due to material destruction.

From Table 1, a high value of elastic gradient is obtained in Reference Examples 1 to 5 and Example 1 . On the other hand, in Comparative Example 1, the elastic gradient was low and the rigidity was insufficient. Further, as in Comparative Example 2, the elastic gradient can be set to the same value as in the present invention, but in that case, it is necessary to significantly increase the basis weight of the base material, which increases the weight and reduces the weight. From the viewpoint of conversion, favorable results were not obtained.

As a result of examining the adhesiveness of the skin material, in Reference Examples 1 to 4 and Example 1 , the skin was broken, and the adhesiveness of the skin material was sufficiently satisfactory. In Reference Example 5 , it was 3N, which was a satisfactory result. On the other hand, in Comparative Example 1, it was 2N, and the adhesive strength was insufficient. Therefore, when the basis weight of the base material is increased as in Comparative Example 2 so that the adhesive strength is at the same level as in the present invention, the adhesive strength is satisfactory, but the weight is increased.

Moreover, the measurement result of the in-pipe sound absorption rate of Reference Examples 1-3 and Example 1 and Comparative Examples 1 and 2 is shown in FIG. The sound absorption coefficient in the tube is measured in accordance with JIS A 1405-2, in which sound waves are incident perpendicularly to the surface side without the skin material, that is, the surface on the high-density surface side, in a state where the back air layer is 0 mm. The in-tube sound absorption coefficient was measured. From FIG. 8, Reference Examples 1 to 3 of the present invention and Examples 1 and Comparative Example 2 are excellent in sound absorption characteristics, but Comparative Example 1 is inferior in sound absorption characteristics. Reference examples 4 and 5 were not compared, but were omitted because it seems that the same results as in reference examples 1 to 3 were obtained.

  The present invention can be advantageously applied to vehicle interior members that are desired to be reduced in weight, such as ceiling materials and rear package materials.

1 Stampable sheet 2 Skin material
202 knit
203 urethane foam 3 bonding member 31 reinforced fiber 32 thermoplastic resin 33 heat-expandable particle 4 expansion bonding member 5 resin sheet
501 spunbond nonwoven fabric
502 core material
503 sheath 8 base material 21 hot press machine 22 cold press machine

Claims (3)

Prepare a stampable sheet containing a thermoplastic resin, reinforcing fibers and heat-expandable particles in a dispersed manner,
This stampable sheet, foamed urethane foam layer and the foamed urethane layer overlaid skin material consisting of the bonded knit on the front side of the Rutotomoni, the stampable sheet skin material side of the surface and said surface skin material to be overlaid Place a resin-made sheet of spunbond nonwoven fabric with a core-sheath structure between the urethane layer and make the skin material overlap on this resin-made sheet , then heat-compress with a flat plate type hot press machine. After pressing the skin material onto the stampable sheet surface and producing a bonding member in which the skin material is stuck to the stampable sheet,
Hot Open press the thermal expandable particles of the stamper in Bull sheet of heated laminated member by expanding to form an expansion lamination member having a predetermined thickness,
Then, the expansion | swelling bonding member is put into a cold press machine, and it press-molds, and shape | molds the vehicle interior member, The molding method of the vehicle interior member characterized by the above-mentioned. In the molding method of the interior member for vehicles according to claim 1 ,
A method for molding an interior member for a vehicle, wherein the core material of the core-sheath structure is made of PET resin, and the surface side of the core material is made of an olefin resin. In the molding method of the interior member for vehicles according to claim 1 or 2 ,
In a hot press machine, the stampable sheet and the skin material are heated at 160 to 210 ° C., and the stampable sheet thickness is compressed to 0.9 times or less compared with that before compression and held for 5 to 30 seconds. A method for forming an interior member for a vehicle, which is characterized in that: