JP2010235858A - Sheet for decorative molding, decorative molded product, sheet structure for decorative molding, and method for producing the decoratively molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for decorative molding, which gives a decorative molded product having excellent dimensional stability and appearance characteristics. <P>SOLUTION: The sheet for decorative molding is composed of a fiver interlaced body 1 of an ultra-fine fiber bundle and a polymer elastomer 2 impregnated with the fiber structure. The ultra-fine fiber bundle is formed of at least five filaments, each made of an ultra-fine monofilament of average fineness of 0.01-0.8 dtex. In an arbitrary cross section parallel to the thickness direction of the fiber interlaced body, the number of cross sections of the ultra-fine fiber bundles exists in the range of at least the average of 1,000/mm<SP>2</SP>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a decorative molding sheet used for producing a decorative molded body having a leather-like appearance, and a decorative molded body obtained using the decorative molding sheet. Specifically, in the case of obtaining a deeply drawn decorative molded body having a leather-like surface, a decorative molding sheet that can suppress appearance defects due to warpage, heat shrinkage, wrinkles generated at the corner forming part, and the like. Etc.

  Decorative molding with a leather-like appearance on the surface, used for insert molding and vacuum molding, as exterior parts for mobile phones, mobile devices, home appliances, interior parts for vehicles, aircraft, building materials, furniture, etc. Sheets are known.

  For example, in the following Patent Document 1, a surface layer composed of leather or synthetic leather pre-formed in a three-dimensional shape, and a resin plate in close contact with the back surface of the leather or synthetic leather, and the surface layer are configured. There is disclosed a three-dimensional leather insert molded product comprising a back surface layer made of an injection molded resin layer closely integrated with a back surface of a resin plate. And as its manufacturing method, leather or synthetic leather was bonded to a resin plate by an adhesive or heat welding, and a decorative molded body was obtained by pressure forming, vacuum forming or pressing the bonded body. It is described that the surface of an injection molded product can be decorated by insert molding using a decorative molded body. Moreover, the following patent document 2 discloses a decorative molding sheet using a porous layer formed by a wet coagulation method by applying a polyurethane material on a release substrate.

JP 2006-175639 A JP 2008-291089 A

  Patent Document 1 does not describe details of synthetic leather. Well-known synthetic leather usually contains a relatively high proportion of polyurethane. When a decorative molded body is molded using such a conventionally known general synthetic leather, there is a problem that a molded body with excellent dimensional accuracy cannot be obtained.

  Further, in the molding of a conventional decorative molded body, for example, when forming a deep-drawn shaped molded body, a large warp as shown in FIG. 9 occurs, or a deep-drawn-shaped curve as shown in FIG. There was a problem that wrinkles occurred at the corners and corners. In addition, when the molded body is released from the mold after being released from the mold, there is also a problem that the whole is deformed so as to contract.

  An object of this invention is to provide the sheet | seat for decorative shaping | molding for obtaining the decorative molded object which was excellent in the dimensional stability and the external appearance characteristic which solved the said problem.

  As a result of studying the reason why the above-described decorative molded body is greatly shrunk, warped, or partially wrinkled after molding, the present inventors have found that It was noted that polymer elastic bodies such as polyurethane contained in the sheet tend to shrink when released from the mold after molding, and that the followability to the mold tends to be poor. And as a result of earnestly studying a configuration that can obtain a molding sheet that hardly shrinks and has excellent followability to the mold, the present invention has been conceived.

That is, the decorative molding sheet according to the present invention is a decorative molding sheet comprising a fiber entangled body of an ultrafine fiber bundle and a polymer elastic body impregnated in the fiber entangled body, and the ultrafine fiber bundle is It is formed from a bundle of five or more long fibers having an average fineness of 0.01 to 0.8 dtex, and in the cross section parallel to the thickness direction of the fiber entangled body, the average cross section of the ultrafine fiber bundle is 1000 / mm ^2. It exists in the above range. In the decorative molding sheet, the fiber ratio is increased by using a fiber bundle made of ultrafine single fibers of long fibers. Then, by increasing the fiber ratio, the form stability can be maintained even if the content ratio of the polymer elastic body is reduced. Thereby, shrinkage when released from the mold can be suppressed. In addition, since the fiber entangled body made of ultrafine single fibers is easily stretched even with a light force when softened, it is possible to maintain excellent followability to the mold during thermoforming.

  The content of the polymer elastic body is preferably 25% by mass or less from the viewpoint of maintaining form retention and mechanical properties.

  In addition, the decorative molding sheet is a polymer elastic body in which, when a silver surface layer made of a polymer elastic body is formed on the surface, ultrafine single fibers on the surface of the fiber entangled body constitute a silver surface layer. Since it is bound, it is preferable from the viewpoint of improving the form stability.

  Further, the resin forming the long fibers is preferably isophthalic acid-modified polyethylene terephthalate because the stretchability of the ultrafine single fiber is high, and is preferable from the viewpoint of excellent moldability.

  Moreover, the decorative molded body according to the present invention is characterized in that any one of the above-mentioned decorative molding sheets is disposed on the surface of a three-dimensional resin molded body. Such a decorative molded body is a molded body having a leather-like surface and excellent in dimensional stability.

  Moreover, the decorative molding sheet structure according to the present invention is obtained by bonding the decorative molding sheet according to any one of the above and a base material with a hot-melt adhesive.

  Moreover, the manufacturing method of the decorative molded body according to the present invention includes a heating step of softening the decorative molding sheet structure by heating to a temperature not lower than a melting point temperature of a glass transition temperature of the ultrafine fiber, and A molding step in which the decorative molding sheet structure softened by the heating step is pressed against the surface of the three-dimensional mold.

  By performing thermoforming using the decorative molding sheet according to the present invention, a decorative molded body with less deformation after thermoforming and having the mold shape accurately transferred can be obtained.

FIG. 1 is a schematic cross-sectional view of a decorative molding sheet according to this embodiment. FIG. 2 is a schematic cross-sectional view of the decorative molding sheet structure of the present embodiment. FIG. 3 is an explanatory diagram for explaining a method of molding using the decorative molding sheet structure. FIG. 4 is an explanatory view for explaining insert molding using a decorative molded body. FIG. 5 shows a design shape of a square dish-shaped molded body molded in the example. FIG. 6 shows the design shape of the hemispherical molded body molded in the example. FIG. 7 shows SS curves at room temperature and 150 ° C. of the molding sheets obtained in Example 1 and Comparative Example 1. FIG. 8 shows 30% elongation recovery curves at 150 ° C. of the molding sheets obtained in Example 1 and Comparative Example 1. It is a schematic diagram explaining the curvature which generate | occur | produces after shaping | molding in the conventional molded object for inserts. It is a schematic diagram explaining the wrinkle of the deep drawing-shaped curved part which occurs after shaping | molding in the conventional molded object for inserts.

  Hereinafter, preferred embodiments of the decorative molding sheet according to the present invention will be described.

FIG. 1 is a schematic cross-sectional view of a decorative molding sheet 10 of the present embodiment. In FIG. 1, 1 is an entangled body of ultrafine fiber bundles composed of ultrafine single fibers 1a having an average fineness of 0.01 to 0.8 dtex, 2 is a polymer elastic body, and 3 is a void. Reference numeral 4 denotes a silver surface layer provided on the surface of the decorative molding sheet 10 as necessary. The polymer elastic body 2 is impregnated and integrated with the ultrafine fiber entangled body 1. The ultrafine fiber bundle is formed from ultrafine single fibers 1a that are long fibers. The decorative molding sheet 10 includes an ultrafine fiber entangled body 1 in an arbitrary cross section parallel to the thickness direction of the fiber entangled body, and the cross section of the ultrafine fiber bundle is present in an average of 1000 pieces / mm ² or more. Features. In addition, the existence ratio of this ultrafine fiber bundle can be calculated | required by observing with a scanning electron microscope as a structural component of the sheet | seat 10 for decorative shaping | molding.

  The ultrafine fiber entangled body 1 has an average fineness of 0.01 to 0.8 dtex, preferably 0.05 to 0.5 dtex, particularly preferably 0.07 to 0.1 dtex. It is a bundle of fiber entanglements. When the average fineness of the ultrafine single fiber is less than 0.01 dtex, it is difficult to produce the ultrafine single fiber. On the other hand, when the average fineness of the ultrafine fibers exceeds 0.8 dtex, when the decorative molding sheet is thermoformed, the stretchability at the time of softening is lowered, and it is difficult to accurately transfer the mold shape. In the decorative molding sheet of the present embodiment, since the ultrafine single fiber having such a fineness is a main constituent element, an elongation characteristic that is easily stretched when softened is obtained.

  The ultrafine single fiber 1a exists in the ultrafine fiber entangled body 1 as a fiber bundle formed by converging the ultrafine single fibers. Specifically, 5 or more, preferably 5 to 1000, more preferably 5 to 200, still more preferably 10 to 70, particularly preferably 10 to 50, and most preferably 10 to 30 ultrafine units. Fibers are bundled and exist. As a result of the ultrafine single fibers forming a fiber bundle, a bundle of fiber bundles expresses the characteristics of a single thick fiber. Moreover, since the ultrafine single fiber forms the fiber bundle, the fiber ratio in the apparent volume of the decorative molding sheet 10 can be increased. By these, even if the content rate of a polymeric elastic body is low, high intensity | strength and a bending elastic modulus can be provided to the decorating surface of the decorating molded product obtained.

  As a thermoplastic resin which forms the ultrafine single fiber 1a, melting | fusing point is 160-330 degreeC, Furthermore, resin with 180-280 degreeC is preferable. By using a thermoplastic resin having such temperature characteristics, a decorative molded body having excellent shape stability can be obtained, and it is preferable from the viewpoint that practical thermal characteristics can be obtained in the thermoforming process. . In addition, melting | fusing point is the peak top temperature of the endothermic peak measured with a differential scanning calorimeter (DSC).

  Specific examples of such thermoplastic resins include, for example, polyethylene terephthalate (PET), modified polyethylene terephthalate, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytriethylene terephthalate, polyhexamethylene terephthalate, polypropylene. Aromatic polyester resins such as terephthalate and polyethylene naphthalate; aliphatic polyesters such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer Resins; polyamides such as polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 11, polyamide 12, polyamide 6-12 Fat; Polyolefin resin such as polypropylene, polyethylene, polybutene, polymethylpentene, chlorinated polyolefin, ethylene vinyl acetate copolymer, styrene ethylene copolymer; modified polyvinyl alcohol containing 25 to 70 mol% of ethylene unit, etc. Examples thereof include modified polyvinyl alcohol resins formed; and crystalline elastomers such as polyurethane elastomers, polyamide elastomers, and polyester elastomers. These may be used alone or in combination of two or more. Among these, aromatic polyester-based resins, particularly modified polyesters containing a copolymer component for lowering the melting point, softening point, and crystallinity as a constituent unit are preferred from the viewpoint of better thermoformability.

  Examples of the copolymer component that constitutes the structural unit in the modified polyester include asymmetric aromatic carboxylic acids such as isophthalic acid, phthalic acid, and 5-sodium sulfoisophthalic acid, and aliphatic dicarboxylic acids such as adipic acid.

  Next, the form etc. of the ultrafine fiber bundle which comprises the ultrafine fiber entanglement body 1 are demonstrated in detail.

  The ultra-fine fiber bundle constituting the ultra-fine fiber entangled body 1 is formed from long ultra-fine single fibers 1a. Here, the long fiber means that it is not a short fiber cut by a predetermined length. The length of the long fiber is preferably 100 mm or more, and more preferably 200 mm or more from the viewpoint of sufficiently increasing the fiber density of the ultrafine single fiber. When the length of the ultrafine single fiber is too short, it is difficult to increase the density of the fiber, so that a sufficiently high rigidity cannot be obtained. Although an upper limit is not specifically limited, For example, when the fiber entanglement body derived from the nonwoven fabric manufactured by the spunbond method is contained, several m, several hundred m, several km or more continuously spun The fiber length may be used. Further, these fibers may be mixed with several kinds of fibers instead of single. Moreover, in the range which does not impair the effect of this invention, you may contain a small amount of short fibers for the purpose of preparing a feel.

In the present embodiment, the ultrafine fiber entangled body 1 has an ultrafine fiber bundle in an arbitrary cross section parallel to the thickness direction of the fiber entangled body 1 so that the cross section of the ultrafine fiber bundle is in the range of 1000 / mm ^{2 on} average. A decorative molding sheet containing 1a densely can be obtained. Then, by using the ultrafine fiber entangled body 1 containing such ultrafine single fibers 1a densely, the shape stability after molding without shrinking or warping the molded product after thermoforming. Can be maintained.

  Moreover, it is preferable that the ultrafine fiber entangled body 1 has a small longitudinal and lateral characteristic ratio. By using an ultrafine fiber entangled body having a small vertical / horizontal characteristic ratio in this way, it is uniformly stretched during thermoforming, so that excellent followability to the mold can be maintained.

  A method for producing such an ultrafine fiber entangled body will be described in detail later.

  Next, the ultrafine fiber entangled body 1 and the polymer elastic body 2 to be impregnated and integrated will be described in detail.

  Specific examples of the polymer elastic body in the present embodiment include polyurethane elastomers, acrylonitrile elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and the like. Of these, polyurethane elastomers and acrylic elastomers are preferably used.

As the content ratio of the ultrafine fiber entangled body 1 in the decorative molding sheet 10, the average number of cross sections of the ultrafine fiber bundle is 1000 / mm ² or more in an arbitrary cross section parallel to the thickness direction of the ultrafine fiber entangled body. in the range, preferably in the range of 1000 to 3000 pieces / mm ^2, and more preferably still in the range of average 2100-2600 pieces / mm ^2. When the number is less than 1000 pieces / mm ^{2, a} space in which the ultrafine fiber bundle does not exist is generated as much as the number density of the ultrafine fiber bundle is small. Since there is a tendency to be divided into a non-existent area and a sparse area that hardly exists, the formability tends to vary. Further, when the space generated between the ultrafine fiber bundles becomes large, a thick polymer elastic body continuous film is easily formed, and molding spots are likely to occur. The upper limit of the number of cross-sections of the ultrafine fiber bundle is not particularly limited, but it is difficult to produce an ultrafine fiber entangled body exceeding 3000 / mm ² and the texture of the obtained molded product tends to be hard. When the content ratio of the ultrafine fiber bundle constituting the ultrafine fiber entangled body 1 is too low, the form stability cannot be maintained unless the polymer elastic body is contained at a high ratio. In this case, the shape stability cannot be maintained because the molded product shrinks after molding.

  It is preferable to make it contain in the range whose content rate of the polymeric elastic body 2 is 25 mass% or less, Furthermore, 20-5 mass%. When the content ratio of the polymer elastic body 2 is too low, the shape stability tends to decrease. However, when the silver surface layer 4 is provided on the surface of the decorative molding sheet 10, the resin component constituting the silver surface layer 4 may constrain a part of the ultrafine fiber entanglement, which also causes the ultrafine fiber entanglement. The coalescence is restrained, and the form stability can be maintained.

  The silver surface layer 4 is a layer for imparting a silver surface-like appearance formed on the surface of the decorative molding sheet 10.

  The resin component for forming the silver surface layer 4 is not particularly limited. Specific examples thereof include various polyurethane resins such as polycarbonate polyurethane resins, polyester polyurethane resins, and polyether polyurethane resins, acrylic resins, polyurethane acrylic composite resins, polyvinyl chloride, and synthetic rubbers. . These resins may be used alone or in combination of two or more. Moreover, you may add various well-known additives as needed. Among these, polyurethane resins are preferable from the viewpoint of excellent adhesiveness, mechanical properties such as wear resistance and flex resistance.

  Such a silver surface layer 4 is formed by applying a solution of a resin component for forming a silver surface layer on the surface of the decorative molding sheet 10 and then drying and solidifying the solution. The silver surface layer 4 may have a laminated structure in which an anchor coat layer is provided for the purpose of improving the adhesion to the decorative molding sheet 10 or a top coat layer is provided on the surface.

  The thickness of the silver surface layer 4 is preferably 10 to 500 μm, more preferably 20 to 100 μm, and particularly preferably 40 to 80 μm.

  The embossed pattern may be formed on the surface of the decorative molding sheet 10 by using a known embossing machine as necessary. By imparting such a pattern, the surface of the decorative molded product obtained can be further realized with an appearance similar to leather.

  The decorative molded body is obtained by molding the decorative molding sheet 10 by a molding method such as press molding, vacuum molding, pressure molding, or insert molding.

  In order to mold a decorative molded body, a decorative molding sheet is arranged as it is in an insert molding die as it is, and injection molding is performed. For example, a base made of a thermoplastic resin as shown in FIG. Even if the decorative molding sheet structure 20 obtained by pasting the decorative molding sheet 10 described above on the surface of the material 5 is formed, it may be molded by press molding, vacuum molding, compressed air molding, or the like. Good.

  As the base material 5 used for the decorative molding sheet structure 20, a base material made of a thermoplastic resin that is easily stretched by press molding, vacuum molding, pressure molding, or the like is used. Examples of such base materials include foaming resins such as foamed polyolefin sheets, foamed urethane sheets, and foamed polystyrene sheets, and thermoplastic elastomers such as polyester-based thermoplastic elastomer sheets, polyamide-based thermoplastic elastomer sheets, and fluorine-based thermoplastic elastomer sheets. An elastic resin sheet made of or the like is preferably used.

  The decorative molding sheet structure 20 is configured by bonding the decorative molding sheet 10 to the base material 5 via an adhesive or by thermocompression bonding. As the adhesive, a hot-melt adhesive that can be stretched by heat is preferably used.

  The decorative molding sheet structure 20 is particularly preferably used for decorative molding (decorative insert molding) using insert molding.

  The decorative molding sheet structure 20 is molded into a three-dimensional shape corresponding to the insert portion in the cavity of the injection molding die, for example, by hot press molding as shown in FIG. Specifically, first, as shown in FIG. 3A, the decorative molding sheet structure 20 is softened by heating to a temperature not lower than the melting point temperature and not lower than the glass transition temperature of the ultrafine fibers (heating step). . Next, as shown in FIG. 3B, the decorative molding sheet structure 20 softened by the heating process is pressed against the surface of the three-dimensional mold 7 and molded (molding process). And as shown in FIG.3 (c), after releasing from the metal mold | die 7, the decorative molded body 30 is obtained by cooling. Note that vacuum forming, pressure forming, or the like may be used instead of hot press forming.

  The decorative molded body 30 thus obtained is inserted into the insert portion in the cavity of the injection mold, and the resin is injected onto the back surface of the decorative molded body 30 to decorate the surface of the injection molded body main body. It can shape | mold so that a molded object may be integrated.

  Specifically, as shown in FIG. 4A, the decorative molded body 30 is inserted into the insert portion 6a in the cavity of the injection mold 6 and then injection molded as shown in FIG. 4B. The molten resin is injected from the gate 6b. And the insert molded object 40 by which the surface integrated with the injection molded object was decorated is obtained by releasing as shown in FIG.4 (c).

  Next, an example of the manufacturing method of the decorative molding sheet of this embodiment will be described in detail.

  The decorative molding sheet of the present embodiment includes, for example, (1) a web manufacturing process for manufacturing a long fiber web made of ultrafine fiber-generating fibers such as sea-island composite fibers by melt spinning, and (2) the obtained length. A web entanglement step of forming a web entanglement sheet by entwining a plurality of fiber webs; (3) a moist heat shrinkage treatment step of moist heat shrinking the web entanglement sheet; and (4) a web entanglement sheet. A polymer elastic body impregnation step of impregnating the polymer elastic material material and then solidifying; and (5) a fiber entanglement forming step of converting the ultrafine fiber generating fiber in the web entangled sheet into ultrafine single fibers. It can be obtained by such a method.

  Each step will be described in detail below.

(1) Web manufacturing process In this process, first, a long fiber web made of ultrafine fiber generating fibers such as sea-island type composite fibers is manufactured by melt spinning.

  In the web forming step, for example, a so-called spunbond method is preferably used, in which a fine fiber-generating fiber is spun using a melt spinning method, and this is collected on a net without cutting to form a web. Used.

  Here, the “ultrafine fiber generating fiber” refers to a multicomponent composite fiber composed of at least two types of polymers. As such a multicomponent composite fiber, a plurality of different resin components are alternately arranged on the outer periphery of the fiber to form a separated split composite fiber in which a petal shape or a superposed shape is formed; Examples include sea-island fibers in which domains are formed in a form in which a polymer of an island component different from the polymer of a sea component is dispersed in the polymer. Among these, sea-island type fibers are preferable from the viewpoint of excellent productivity.

  That is, the sea-island type fiber has very little fiber damage such as cracking, bending, and cutting when performing the fiber entanglement process represented by the needle punch process. Therefore, it is possible to form ultrafine single fibers having a finer fineness. Therefore, a dense fiber entangled body can be obtained.

  The sea-island type fibers are formed by forming a web-entangled sheet, and the sea component polymer is extracted or decomposed at an appropriate later stage. A fiber bundle composed of ultrafine single fibers can be formed by this decomposition removal or extraction removal. Such a sea-island type fiber can be obtained by using a spinning method of a multicomponent composite fiber represented by a conventionally known chip blend (mixed spinning) method or a composite spinning method.

  As the thermoplastic resin constituting the island component of the sea-island fiber, the above-described various thermoplastic fibers are used. On the other hand, as the thermoplastic resin that constitutes the sea component of the sea-island fiber, a thermoplastic resin that is different from the thermoplastic resin that constitutes the island component in solubility in a solvent or decomposability in a decomposing agent is selected. In particular, from the viewpoint of spinning stability, it is a resin having a low affinity with the thermoplastic resin constituting the island component, and the melt viscosity or surface tension under the spinning conditions is higher than that of the thermoplastic resin constituting the island component. A small thermoplastic resin is preferred.

  Specific examples of the thermoplastic resin constituting the sea component include, for example, polyethylene, polypropylene, polystyrene, ethylene propylene copolymer, ethylene vinyl acetate copolymer, styrene ethylene copolymer, styrene acrylic copolymer, and polyvinyl alcohol. Resin etc. are mentioned. Of these, polyvinyl alcohol resins, particularly ethylene-modified polyvinyl alcohol resins, are preferred because they are easily contracted by wet heat or hot water.

  Specific examples of the thermoplastic resin constituting the island component include the above-described aromatic polyester resins such as polyethylene terephthalate (PET) and modified polyethylene terephthalate; aliphatic polyester resins; polyamide resins; polyolefin resins; Examples thereof include modified polyvinyl alcohol resins formed from alcohol and the like; and crystalline elastomers.

  These may be used alone or in combination of two or more.

  A spunbond method or the like is used for spinning the ultrafine fiber generating fiber and forming the web. Specifically, for example, by using a composite spinning die in which a large number of nozzle holes are arranged in a predetermined pattern, ultrafine fiber generating fibers are continuously connected from individual nozzle holes to a conveyor belt-like movable net. It is made to discharge, and it deposits, cooling using high-speed airflow. A web is formed by such a method.

  The web formed on the net is preferably subjected to a fusion process. Form stability is imparted by the fusing process. In addition, in the sheet | seat for shaping | molding of this embodiment, it is preferable from the point which ensures the outstanding moldability that the fusion | melting point of ultrafine fiber bundles is as few as possible. Therefore, it is preferable to perform the fusion so that the fiber components remaining after the ultrafine fiber formation do not cause fusion.

As a specific example of the fusion process, for example, a hot press process can be cited. As a heat press process, the method of using a calender roll and applying a predetermined pressure and temperature, for example, can be employed. The temperature for the hot press treatment is preferably 10 ° C. or more lower than the melting point of at least one component of the ultrafine fiber generating fiber (at least one component present on the surface). In particular, in the case of a sea-island fiber, it is preferably 10 ° C. or lower than the melting point of the component constituting the sea component. When the temperature is lower by 10 ° C. or more, while maintaining good shape stability of the web, it is possible to prevent entanglement failure and formation of needle holes when entangled webs after stacking, and to obtain a high-quality nonwoven fabric. The lower limit of the temperature for the hot press treatment is not particularly limited as long as the fusion treatment is possible, but it is easy to fuse if the temperature is 150 ° C. lower than the melting point of at least one component of the ultrafine fiber-generating long fiber. preferable. The web basis weight after heat pressing is preferably in the range of 20 to 60 g / ^{m 2.} By being in the range of 20 to 60 g / m ² , good form retention can be maintained in the next stacking step.

(2) Web entanglement process Next, the web entanglement process which forms a web entanglement sheet | seat by overlapping and entangling about 5-100 sheets of the obtained long fiber web is demonstrated.

  The web entangled sheet is formed by performing an entanglement treatment on the long fiber web using a known nonwoven fabric manufacturing method such as needle punching or high-pressure water flow treatment. Below, the entanglement process by a needle punch is demonstrated in detail as a typical example.

  First, a silicone oil agent or a mineral oil agent such as a needle breakage prevention oil agent, an antistatic oil agent, and an entanglement improving oil agent is applied to the long fiber web.

Thereafter, for example, an entanglement process is performed in which the fibers are entangled three-dimensionally by a needle punch. By performing the needle punching process, a web entangled sheet having a high fiber density and hardly causing the fiber to come off can be obtained. The basis weight of the web entangled sheet is appropriately selected according to the thickness of the target forming sheet, and specifically, for example, it is handled in the range of 500 to 2000 g / m ^2. It is preferable from the point which is excellent in property.

The conditions for increasing the delamination force of the web entangled sheet are appropriately selected as the needle conditions such as the type and amount of the oil agent, the needle shape in the needle punch, the needle depth, and the number of punches. The number of barbs is preferably as large as possible without causing needle breakage. Specifically, for example, the number of barbs is selected from 1 to 9 barbs. The needle depth is preferably set so that the barb penetrates to the overlapped web surface, and in a range where the pattern after needle punching does not appear strongly on the web surface. The number of needle punches is adjusted according to the shape of the needle, the type and amount of oil used, and specifically, it is 400 to 8000 punch / cm ² , and more specifically 1000 to 4000 punch / cm ² . preferable.

  If necessary, a needle board having different needle densities in the width direction is used so that the punch density is different in the width direction in order to make the fabric weight in the width direction uniform and to make the vertical / horizontal balance of the stretch characteristics more uniform. It is also possible. The web entangled sheet obtained by such needle punching is preferable for realizing more uniform extensibility and formability based thereon.

(3) Heat Shrinkage Treatment Step Next, a heat shrinkage treatment step for increasing the fiber density and the degree of entanglement of the web entangled sheet by thermally shrinking the web entangled sheet will be described. In this step, the web entangled sheet containing long fibers is thermally shrunk, so that the web entangled sheet is greatly shrunk compared to the case where the web entangled sheet containing short fibers is heat shrunk. As a result, the fiber density of the ultrafine single fiber is particularly high. The heat shrinkage treatment condition is not particularly limited as long as it is a temperature at which sufficient shrinkage can be obtained. For example, when shrinkage treatment is performed by introducing into warm water, the shrinkage treatment is preferably performed at any temperature within a temperature range of 70 to 150 ° C. Also, dry heat shrinkage is preferably employed, but wet heat shrinkage treatment is more preferred, and the wet heat shrinkage treatment method is preferably performed by steam heating. As steam heating conditions, it is preferable to heat-treat for 60 to 600 seconds under the conditions of an ambient temperature of 60 to 100 ° C. and a relative humidity of 40 to 100% RH and 70 to 100% RH. Such heating conditions are preferable because the web-entangled sheet can be shrunk at a high shrinkage rate. In addition, when a polyvinyl alcohol-based resin is used as a constituent component of the sea-island type composite fiber, if the relative humidity is too low, the moisture in contact with the fiber tends to dry quickly and the shrinkage tends to be insufficient. .

  The web entangled sheet thus subjected to the wet heat shrinkage treatment may be further increased in fiber density by heating roll or hot pressing at a temperature equal to or higher than the heat deformation temperature of the ultrafine fiber generating fiber.

  As a change in the basis weight of the web-entangled sheet in the wet heat shrinkage treatment step, it is 1.1 times (mass ratio) or more, further 1.3 times or more as compared with the basis weight before the shrinkage treatment, and 2.0. It is preferable that it is 2 times or less, and further 1.6 times or less.

(4) Polymer elastic body impregnation step For the purpose of enhancing the form stability of the web entangled sheet, the web entangled sheet subjected to shrinkage treatment as necessary before or after performing the ultrafine fiber forming process of the web entangled sheet The molded elastic sheet may be impregnated with the polymer elastic body by impregnating the polymer elastic body with an aqueous liquid and then solidifying the polymer elastic body.

  For example, the web-entangled sheet is impregnated with the polymer elastic body by impregnating the web-entangled sheet subjected to shrinkage treatment with an aqueous liquid of the polymer elastic body and solidifying the web-entangled sheet.

  Examples of the method of impregnating the web entangled sheet with the polymer elastic body include a method of impregnating a solution or dispersion of the polymer elastic body and coagulating it by a conventionally known dry method or wet method. As the impregnation method, the web entangled sheet is immersed in a bath filled with a solution or dispersion of a polymer elastic body and then squeezed into a predetermined impregnation state with a press roll or the like once or plural times. The dip nip method is preferably used. As other methods, a bar coating method, a knife coating method, a roll coating method, a comma coating method, a spray coating method, or the like may be used.

  Specific examples of the polymer elastic body in the present embodiment include polyurethane elastomers, acrylonitrile elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and the like.

  Examples of the polyurethane elastomer include various polyurethane elastomers obtained by reacting a polymer polyol having an average molecular weight of 500 to 3000, an organic polyisocyanate, and a chain extender in a predetermined molar ratio.

  Specific examples of the polymer polyol include polymer polyols having an average molecular weight of 500 to 3000, such as polyester diol, polyether diol, polyether ester diol, and polycarbonate diol. Specific examples of the organic polyisocyanate include aromatic isocyanates such as 4,4′-diphenylmethane diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate. It is done. Examples of the chain extender include low molecular compounds having two or more active hydrogen atoms such as ethylene glycol and ethylenediamine.

  By impregnating a web entangled sheet with a polymer elastic body fluid such as a solution or dispersion of a polymer elastic body, and then coagulating the polymer elastic body by a conventionally known dry method or wet method, the polymer elastic body is made into a web. Secure in the entanglement sheet. The dry method here refers to all methods for fixing a polymer elastic body in a web entangled sheet by removing a solvent or a dispersant by drying or the like. In addition, the wet method referred to here is a treatment of a web entangled sheet impregnated with a polymer elastic body fluid with a non-solvent or a coagulant of the polymer elastic body, or a polymer elastic body fluid to which a heat-sensitive gelling agent is added. A method of temporarily fixing or completely fixing the polymer elastic body in the web entangled sheet prior to removing the solvent or the dispersant by adopting heat treatment of the web entangled sheet after impregnation. Refers to general. In order to completely fix the solidified polymer elastic body, it is also preferable to perform a curing treatment such as a heat treatment after removing the solvent or the dispersant.

  The concentration of the polymer elastic body fluid, that is, the content of the polymer elastic body in the polymer elastic body fluid is preferably 0.1 to 60% by mass. In the polymer elastic body fluid, colorants such as dyes and pigments, coagulation regulators, antioxidants, ultraviolet absorbers, fluorescent agents, anti-molds, etc., as long as the properties of the finally obtained decorative molding sheet are not impaired. Agent, penetrating agent, antifoaming agent, lubricant, water repellent, oil repellent, thickener, extender, curing accelerator, foaming agent, water-soluble polymer compound such as polyvinyl alcohol and carboxymethylcellulose, inorganic fine particles, conductive agent Etc. may be further contained.

(5) Ultrafine fiber formation process Next, the ultrafine fiber formation process which makes the ultrafine fiber generation type | mold fiber in a web entanglement sheet ultrafine single fiber is demonstrated.

  The ultra-fine fiber formation process is a process of converting sea-island type composite fibers into ultra-fine fibers by extracting or decomposing and removing sea components of sea-island type composite fibers with water, solvents, etc. In the case of using a web entangled sheet made of sea-island type composite fiber using a water-soluble resin as a sea component or a complex of a web entangled sheet and a polymer elastic body, water, an alkaline aqueous solution, an acidic aqueous solution, etc. This is a step of dissolving or removing the thermoplastic resin constituting the sea component by hot water heat treatment.

  In this process, when the ultrafine fiber is formed by dissolving the sea component thermoplastic resin composed of a water-soluble resin typified by polyvinyl alcohol resin from the sea-island composite fiber, the ultrafine fiber is greatly crimped. . Since the fiber density becomes dense by this crimping, a high-density fiber entangled body is obtained.

The molding sheet of the present embodiment is formed by the processes as described above. By such a sea component polymer removal treatment, the sea-island type fibers are transformed into ultrafine long fiber bundles made of the island component thermoplastic resin, and a sheet for a molded body having a basis weight of preferably 300 to 1800 g / m ² is obtained. It is done.

  The molded body sheet thus obtained may be sliced into a plurality of sheets in the thickness direction, or may be adjusted in thickness or surface condition by grinding. The thickness of the molded body sheet is preferably 0.1 to 1.5 mm, more preferably 0.2 to 1.0 mm, and particularly preferably 0.3 to 0.7 mm. In the case of such a thickness, a leather-like soft touch can be imparted to the molded body.

  Moreover, the sheet | seat structure for decorative shaping | molding is obtained by bonding the obtained sheet | seat for molded objects to a base material.

  Moreover, you may provide a silver surface layer in the surface of the sheet | seat for molded objects as needed. The silver surface layer is formed by applying a solution of a resin component for forming a silver surface layer on the surface of the obtained molded sheet, followed by drying and solidification. The silver surface layer may have a laminated structure in which an anchor coat layer is provided for the purpose of enhancing the adhesion to the decorative molding sheet, or a top coat layer is provided on the surface.

  Furthermore, you may give an embossing pattern to the surface of the sheet | seat for decoration shaping | molding by using a well-known embossing machine as needed. By imparting such a pattern, the surface of the decorative molded product obtained can be further realized with an appearance similar to leather.

  It is preferable that the sheet | seat for molded objects obtained in this way has the following characteristics.

  That is, the breaking strength at 20 ° C. is preferably 150 N / 25 mm or more, more preferably 180 N / 25 mm or more. By adjusting to such a breaking strength, it is possible to withstand the external force for molding at the time of molding and to express the desired form, and to maintain the form stably with respect to the use of the product after molding, and also to have its appearance Can be maintained.

  Further, the elongation at break at 20 ° C. is preferably 100% or more from the viewpoint of giving an excellent texture to the surface of the resulting decorative molded body.

  Moreover, it is preferable to have a breaking elongation of 100% or more even at the temperature at which thermoforming is performed. For example, in the case of a molding sheet using a polyester resin as an ultrafine single fiber and a polyurethane elastomer as a polymer elastic body, at a temperature of about 150 ° C., which is a thermoforming temperature, 100% or more, further 120% or more, particularly Is preferably 150% or more, particularly 200% or more. In the case of having such a breaking elongation at the temperature at which thermoforming is performed, for example, in the case of molding with a deep drawing type mold or a complicated shape mold, the molding sheet is formed into a mold shape in order to sufficiently stretch. It is possible to follow up sufficiently.

  Furthermore, it is preferable that the stress at 30% elongation is 1 to 60 N / 25 mm at the thermoforming temperature. For example, in the case of a molding sheet using a polyester-based resin as an ultrafine single fiber and a polyurethane elastomer as a polymer elastic body, a stress at 30% elongation is 1 to 60 N / 25 mm at about 150 ° C. which is a thermoforming temperature. Further, it is preferably 5 to 55 N / 25 mm, particularly 10 to 50 N / 25 mm, particularly 15 to 40 N / 25 mm. When the stress at the time of 30% elongation is too small at the temperature at which thermoforming is performed, for example, even when forming with a deep drawing type mold or a complicated shape mold, the sheet is likely to be damaged during molding. Tend. On the other hand, if the stress at 30% elongation is too large at the temperature at which thermoforming is performed, wrinkles are likely to occur at the time of molding, particularly in deeply drawn parts or parts of complex shapes. This is a part that needs to be stretched locally and along the mold in this way, especially before it stretches, the sheet around it is gradually moved in a chain and dragged into that part to follow the mold , That part is likely to become a habit.

  In addition, it is preferable that the directionality of the stress is small, and in particular, it is preferable that the directionality of the stress is small at the thermoforming temperature. For example, in the case of a molding sheet using PET as the ultrafine single fiber and polyurethane elastomer as the polymer elastic body, at a temperature of about 150 ° C., which is the thermoforming temperature, the vertical direction (MD) and the transverse direction of the stress at 30% elongation The ratio (MD / CD) in the direction (CD) is preferably 0.5 to 4.3. When the MD / CD is in the above range at the temperature at which thermoforming is performed, accurate molding along the mold can be performed even when molding a deeply drawn or complex shaped product. Thereby, wrinkles generated on the surface layer of the molded body and deformation after molding can be suppressed. In addition, MD / CD ratio can be adjusted at the time of manufacture of a fiber entanglement body by carrying out a wet heat shrink process.

  In the present invention, the shape change at the time of 30% elongation recovery at 150 ° C. is used as an index, and the point where the return stress after elongation is 0 is defined as the residual strain, and this residual strain is 13% or more. It is also important. If this value is less than 13%, the shape will change when released from the mold and cooled, even if it is molded into the desired “mold” along the mold during heating. Therefore, this value is preferably 15% or more, more preferably 17% or more. In such a case, in order to faithfully reproduce the shape of the mold after heat molding, the shape change is reduced during cooling after being molded along the mold.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by the Example.

[Example 1]
Polyethylene terephthalate modified with ethylene modified polyvinyl alcohol (ethylene unit content 8.5 mol%, polymerization degree 380, saponification degree 98.7 mol%) as sea component thermoplastic resin and isophthalic acid modified as island component thermoplastic resin (Content of isophthalic acid unit 6.0 mol%) was melted individually. Then, each molten resin was supplied to a plurality of spinning nozzles in which a large number of nozzle holes were arranged in parallel so as to form a cross-section in which 25 island components having a uniform cross-sectional area were distributed in the sea component. . At this time, it supplied, adjusting a pressure so that the average area ratio of the sea component to an island component in a cross section might be sea component / island component = 25/75. And it was made to discharge from the nozzle hole set to the nozzle | cap | die temperature of 250 degreeC.

Then, the molten fiber discharged from the nozzle hole is drawn by suction with an air jet / nozzle type suction device in which the pressure of the airflow is adjusted so that the average spinning speed is 3600 m / min, and the average cross-sectional area is 177 μm ^2. A sea-island type fiber (about 2.4 dtex) was spun. The spun sea-island type fibers were continuously deposited on the movable net while sucking from the back side of the net. The amount of deposition was adjusted by adjusting the moving speed of the net. And the long fiber web of 30 g / m < ² > of fabric weight was obtained by pressing down the accumulated long fiber with the embossing roll kept at 80 degreeC with the linear pressure of 70 kg / cm.

Next, an oil agent mixed with an antistatic agent is sprayed on the surface of the obtained long fiber web, and then the long fiber web is continuously folded using a cross-wrapper device to laminate a 14-layer laminar long fiber web. Formed body. And the obtained laminated body was three-dimensionally entangled by needle punching. Needle punching was performed in two stages. Specifically, first, the needle A having a needle count of 40 is used, and needle punching is performed at a punch depth through which the barb penetrates in the thickness direction from both sides of the laminate, so that the folded long fiber web does not shift. Tangled. Next, needle B with needle count 42 was used, and needle punching was performed at a punch depth at which the barb penetrated in the thickness direction from both sides of the laminate, thereby sufficiently intertwining in the thickness direction. Needle punching with the needle B was performed with a total number of punches of 1700 punch / cm ² from both sides. Thus, the fiber entanglement body whose fiber density of a sea island type fiber is 500 pieces / mm < ² > was obtained.

The obtained fiber entangled body was densified by being subjected to wet heat shrinkage treatment as follows. Specifically, after 18 ° C. water was uniformly sprayed on both surfaces of the fiber entangled body, it was continuously passed through an atmosphere at a temperature of 75 ° C. and a relative humidity of 95% over 4 minutes. After the wet heat shrinkage treatment, the fiber entanglement was further pressed between metal rolls kept at 120 ° C. Subsequently, it was dried at 120 ° C. By such a process, an extremely dense fiber entangled body having a basis weight of 1125 g / m ² and a sea island-type fiber density of 1900 fibers / mm ² in a cross section parallel to the thickness direction was obtained.

  Next, the densified fiber entangled body was impregnated with polyurethane elastomer as follows. As the polymer elastic body fluid, an aqueous dispersion (solid content concentration: 15%) of a polyurethane composition mainly composed of polycarbonate / ether polyurethane was used. The polymer elastic body fluid was impregnated with 50 parts by mass of the polymer elastic body fluid with respect to 100 parts by mass of the fiber entangled body densified. And it heat-coagulated by irradiating infrared rays for 1 minute on the conditions that the surface temperature of the densified fiber entangled body will be 80 degreeC, and also dried the water | moisture content in the 120 degreeC drying furnace. Then, the polyurethane elastomer was impregnated in the voids of the densified fiber entangled body by performing a curing treatment in an atmosphere furnace at 150 ° C. for 2 minutes.

  Next, the sea entanglement impregnated with the polyurethane elastomer was immersed in hot water at 90 ° C. for 20 minutes to extract and remove sea components contained in the sea-island fibers. And the sheet | seat A for shaping | molding about thickness 1.4mm was obtained by drying with a 120 degreeC drying furnace.

When the cross section of the molding sheet A was observed with a scanning microscope (SEM), have a cross section in the range of 200 to 400 ^2, the fiber bundles having a cross-section of average 250 [mu] m ² was confirmed. Moreover, the fiber bundle was formed from 25 ultrafine single fibers. Further, an average number density (the number of ultrafine fiber bundle cross sections existing per unit area of a cross section parallel to the thickness direction) is measured with an arbitrary cross section parallel to the thickness direction of the fiber entangled body with a scanning electron microscope (100 to 300). And observed at 3 to 10 locations so that the total observation area is 0.5 mm ² or more, and in each observation field, is substantially perpendicular to the length direction of the ultrafine fiber bundle The number of cross sections to be judged was counted. By dividing the total number by the total observation area, the number of ultrafine fiber bundle cross sections existing per 1 mm ² was obtained. The average number density of the fiber entangled body was obtained by arithmetically averaging the number of cross sections of the ultrafine fiber bundle per 1 mm ² in the entire observation visual field. The average number density of the fiber bundle in the thickness direction of the cross section was 2500 / mm ^2. And the urethane elastomer was 15 mass%.

And the mechanical characteristic of the obtained sheet | seat A for molding was measured as follows.
(Breaking strength and breaking elongation)
In accordance with JIS L1096 6.12 “Tensile strength test”, a rectangular test piece having a width of 25 mm and a length of 200 mm was attached so as to have a grip interval of 50 mm. The stress at the time of fracture was read from the stress-strain curve, and the elongation at break was determined from the elongation at that time.
(30% elongation stress)
In the strength-elongation curve in the breaking strength measurement, the stress at 30% elongation was read from the chart.
(Residual strain at 30% elongation recovery)
JIS L1096 8.14.2 Stretch recovery rate and residual strain rate Measured according to the A method.
A rectangular test piece having a width of 25 mm and a length of 200 mm was attached so that the grip interval was 50 mm, and the test piece was stretched by a length corresponding to 30% of the grip interval at a pulling speed of 100% of the grip interval, and then for 1 minute. It was allowed to stand and then returned to its original position at the same speed, and the elongation at which the stress became zero when returning to the original position was defined as 30% elongation recovery residual strain.

  Next, a silver surface layer was formed on the molding sheet A. The silver surface layer was formed as follows.

  Urethane resin solution for skin (Daisen Seika Kogyo Co., Ltd .: Rezamin ME8116LP), intermediate layer urethane resin solution (Daiichi Seika Kogyo Co., Ltd .: Resamine ME8106LP) and urethane resin solution for bonding (Daiichi Seika Kogyo Co., Ltd .: Resin UD8310) was coated, laminated on the molding sheet A of the present invention, and aged for 60 hours at 40 ° C. to cure the resin component. And the sheet | seat A for shaping | molding in which the silver surface layer was formed was obtained by peeling a release paper.

  Next, by using the molding sheet A on which the silver surface layer is formed, a square plate shaped molded body 8 (inner diameter: vertical 100 mm, horizontal 50 mm, height 15 mm) as shown in FIG. 5 and as shown in FIG. 6. It shape | molded using the metal mold | die for obtaining the molded object of a hemispherical shape (inside diameter: diameter 75mm). Molding was performed as follows.

  First, a sheet A for forming a silver surface layer and a polyethylene hot melt at the center between the upper and lower molds of a flat plate mold that is opposed to each other with a pair of upper and lower 10 mm heated to a temperature of 150 ° C. The laminated body which laminated | stacked the film and the foamed polyethylene sheet in order was pre-heated by leaving to stand for 1 minute. A release sheet was disposed on the upper and lower mold surfaces. Then, after preheating, the laminate was brought into contact with a mold for obtaining the molded body of FIG. 5 or FIG. 6 at room temperature and molded at a pressure of 7 MPa for 1 minute.

And the appearance stability after shaping | molding of the obtained molded object was evaluated on the following references | standards about generation | occurrence | production of the curvature of a molded object, shrinkage | contraction, and wrinkles.
(warp)
When one end around the bottom of the hemispherical molded body as shown in FIG. 6 was restrained, the height around the other end facing the restrained one end was measured.
(Shrinkage)
In order to confirm the shrinkage after molding, the height of the obtained hemispherical molded body was measured.
(wrinkle)
The state of occurrence of wrinkles at the corners of the shaped square dish as shown in FIG. 5 was determined according to the following criteria.
Excellent: No generation of wrinkles Inferior: Many fine wrinkles were observed The above evaluation results are summarized in Table 1.

[Example 2]
A molding sheet B was obtained in the same manner as in Example 1 except that polyethylene terephthalate (inherent viscosity 0.65) was used in place of polyethylene terephthalate modified with isophthalic acid as the island component thermoplastic resin.

When the cross section of obtained molded sheet B was observed with a scanning microscope (SEM), have a cross section in the range of 200 to 400 ^2, the fiber bundles having a cross-section of average 250 [mu] m ² was confirmed. Moreover, the fiber bundle was formed from 25 ultrafine single fibers. Moreover, the average number density of the fiber bundles in an arbitrary cross section parallel to the thickness direction was 2200 / mm ² . And the content rate of the urethane elastomer was 20 mass%.

  Then, the molding sheet B was evaluated in the same manner as in Example 1. Further, a silver layer was formed on the surface of the molding sheet B in the same manner as in Example 1, and molding evaluation was performed. The results are shown in Table 1.

[Comparative Example 1]
High fluidity polyethylene was used as the thermoplastic resin for the sea component, and 6-nylon was used as the thermoplastic resin for the island component, and the mixture was melted by mixing at a ratio of 50/50 between the sea component and the island component. The molten polymer was supplied to a spinneret having a large number of nozzle holes arranged concentrically, and was discharged from the nozzle holes at a nozzle temperature of 290 ° C. Sea-island fibers having a fineness of 6.6 dtex were spun by a mixed spinning method in which the discharged polymer was drawn and thinned while converging. The cross section of the sea-island fiber after spinning was in a state where thousands of island components made of nylon 6 were scattered in the sea component made of polyethylene. The obtained sea-island fiber was stretched 3.0 times and crimped to obtain staple fibers cut to a fiber length of 51 mm. Then, a web was formed from the obtained staple fibers using a card machine. And after forming a laminated web by the cross wrap method, it entangled by needle punching and further heat-processed, and the fiber entanglement body weight of 760g / m < ² > was obtained.

  Then, the obtained fiber entangled body was impregnated with polyurethane elastomer in the same manner as in Example 1. And the sea component contained in a sea-island type fiber was extracted and removed by immersing the fiber entanglement body impregnated with the polyurethane elastomer in hot toluene. And the sheet | seat C for shaping | molding about thickness 1.4mm was obtained by drying with a 120 degreeC drying furnace.

When the obtained thickness direction parallel to an arbitrary section of the molded sheet in C was observed with a scanning microscope (SEM), the fiber bundle having a cross-section of average 181Myuemu ² was confirmed. Moreover, the fiber bundle was formed from ultrafine single fibers far exceeding a thousand. Moreover, the average number density of the fiber bundle in the cross section of thickness direction was 650 piece / mm < ² >.

  Then, the molding sheet C was evaluated in the same manner as in Example 1. Further, a silver surface layer was formed on the surface of the molding sheet C in the same manner as in Example 1, and molding evaluation was performed. The results are shown in Table 1.

  As shown in Table 1, the hemispherical molded body obtained using the molding sheet A of Example 1 and the molding sheet B of Example 2 had a small warp and a high height. This seems to be because the shrinkage after molding is small. In addition, almost no wrinkles occurred at the corners of the square dish-shaped molded body obtained using the molding sheet A of Example 1 and the molding sheet B of Example 2.

  On the other hand, the hemispherical molded body obtained using the molding sheet C of Comparative Example 1 had a large warp, and contracted to a low height. This seems to be because the shrinkage after molding is large. In addition, a large number of fine wrinkles were generated at the corners of the square dish-shaped molded body obtained using the molding sheet C of Comparative Example 1. As described above, it can be seen that the decorative molded body having a leather-like appearance molded using the molding sheet according to the present invention has little shrinkage and the occurrence of wrinkles is also suppressed.

  FIG. 7 shows the SS curves at room temperature and 150 ° C. in the longitudinal direction of the molding sheets obtained in Example 1 and Comparative Example 1. As shown in FIG. 7, the molding sheet A of Example 1 exhibits an elongation stress of 134 N / 25 mm at room temperature, for example, at 30% elongation, and the molding sheet C of Comparative Example 1 exhibits 30% elongation. The elongation stress of 107 N / 25 mm is shown. Thus, at room temperature, the molding sheet A of Example 1 shows high elongation stress even at 30% elongation. On the other hand, the molding sheet A of Example 1 exhibits only an elongation stress of 32 N / 25 mm at an elongation of 30% at a molding temperature of 150 ° C., for example, and the elongation of 55 N / 25 mm of the molding sheet C of Comparative Example 1 It can be seen that it is lower than the stress. This indicates that the molding sheet A of Example 1 is stronger at room temperature than the molding sheet C of Comparative Example 1, and easily stretched at the time of molding.

  FIG. 8 shows 30% elongation recovery curves at 150 ° C. in the longitudinal direction of the molding sheets obtained in Example 1 and Comparative Example 1. From FIG. 8, the molding sheet A of Example 1 contracts only to the 18% elongation position when the load when stretched by 30% is maintained, whereas the molding sheet C of Comparative Example 1 Was greatly shrunk to an extension position of 13%. This indicates that the molding sheet A of Example 1 is less likely to shrink after molding than the molding sheet C of Comparative Example 1.

DESCRIPTION OF SYMBOLS 1 Ultrafine fiber entanglement 1a Ultrafine single fiber 2 Polymer elastic body 3 Space | gap 4 Silver surface layer 5 Base material 6 Mold for injection molding 6a Cavity insert part 7 Mold 8 Square dish-shaped molded body 9 Hemispherical molded body 10 Addition Decorative Molding Sheet 20 Decorative Molding Sheet Component 30 Decorative Molded Body 40 Insert Molded Body

Claims (7)

A decorative molding sheet comprising a fiber entangled body of an ultrafine fiber bundle and a polymer elastic body impregnated in the fiber entangled body,
The ultrafine fiber bundle is formed from a bundle of 5 or more long fibers having an average fineness of 0.01 to 0.8 dtex,
A decorative molding sheet characterized in that, in an arbitrary cross section parallel to the thickness direction of the fiber entangled body, the cross section of the ultrafine fiber bundle exists in an average range of 1000 / mm ² or more.   The decorative molding sheet according to claim 1, wherein a content ratio of the polymer elastic body is 25% by mass or less.   The decorative molding sheet according to claim 1 or 2, wherein a silver surface layer made of a polymer elastic body is formed on the surface.   The decorative molding sheet according to any one of claims 1 to 3, wherein the long fibers are made of isophthalic acid-modified polyethylene terephthalate.   A decorative molded body, wherein the decorative molding sheet according to any one of claims 1 to 4 is disposed on a surface of a three-dimensional resin molded body.   A decorative molding sheet structure obtained by bonding the decorative molding sheet according to any one of claims 1 to 4 and a base material with a hot-melt adhesive. A heating step of softening the decorative molding sheet structure according to claim 6 by heating to a temperature not lower than the melting point temperature of the glass transition temperature of the ultrafine fibers,
A molding step of pressing the decorative molding sheet structure softened by the heating step against a three-dimensional mold surface to mold the decorative molding body.

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