JP2011046026A - Synthetic resin molding and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin molding which prevents interlaminar peeling even when having a structure consisting of two or more layers and also prevents occurrence of camber and its manufacturing method. <P>SOLUTION: The molding is a synthetic resin molding 7 having a three-layer structure in which an intermediate layer 77 is formed between outer-surface layers 76 in an integrated form. The outer-surface layers 76 laminated on both sides of the intermediate layer 77 are made of a synthetic resin composition filled with a filler 78, and the intermediate layer 77 is formed by impregnating a nonwoven fabric 6 with the resin of either one of the outer-surface layers 76 of the outer-surface layers 76 on both sides of the intermediate layer 77 and hardening without allowing the filler 78 to be contained in the intermediate layer 77. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a synthetic resin molded article and a method for producing the same.

  Conventionally, artificial marble has been used to give a high-class feel to counters such as system kitchen counters and makeup counters. Such artificial marble counters, for example, are filled with a filler for improving strength and heat resistance into an epoxy resin as a main agent, and mixed with a pattern material and a pigment to form a synthetic resin composition. A synthetic resin molded product obtained by curing such a synthetic resin composition, and has a single layer (single layer) structure.

  By the way, when molding a synthetic resin molded product with a marble-like exterior surface like a synthetic marble counter, the marble-like pattern, depth, and three-dimensionality appear. It must be molded using an expensive synthetic resin composition. Therefore, if the entire synthetic resin molded article is configured as a single layer as in the conventional case, an expensive synthetic resin composition is used for a portion that does not contribute to the appearance, so the cost of the synthetic resin composition to be used increases. There is a problem of end.

  Therefore, as a measure to solve this problem, it is conceivable to construct an artificial marble counter with two layers. That is, while using an expensive synthetic resin composition for displaying a marble-like pattern on the surface layer of this artificial marble counter, an inexpensive synthetic resin that does not require a marble-like pattern to appear on the back layer The composition is used to produce a synthetic resin molded article having a two-layer structure with a cost reduction.

  Here, as a general method for producing a synthetic resin molded article having a two-layer structure, a method disclosed in Patent Document 1 is conventionally known.

  The synthetic resin molded article having a two-layer structure shown in Patent Document 1 is manufactured as follows.

  First, the first synthetic resin composition is injected into a cavity formed by closing the upper surface mold and the first lower surface mold. After the first synthetic resin composition is cured, the first lower surface mold is released from the cured first synthetic resin composition (first layer), and the first layer is kept in close contact with the upper surface mold. The second lower surface mold is closed. A second synthetic resin composition is injected into a cavity formed between the lower surface of the first layer and the second lower surface mold. Then, the second layer is formed by curing the second synthetic resin composition.

  By the method as described above, a synthetic resin molded article having a two-layer structure in which the first layer and the second layer are simply laminated is manufactured.

  In addition, in order to improve the strength, heat resistance, etc. of such a synthetic resin molded product, it is known to fill the synthetic resin composition forming the synthetic resin molded product with a filler (for example, Patent Document 2). reference). Such fillers are filled in order to improve strength, heat resistance, etc. In addition to this, in the case of fillers that are cheaper than resins, by increasing the ratio of the filler to the whole, an expensive resin It is also possible to reduce the cost by reducing the amount.

JP-A-5-162171 JP 2005-335198 A

  However, when a synthetic resin composition having a two-layer structure is molded, if the synthetic resin composition is filled with a filler, the strength of each layer is improved, but the mutual adhesion between the first layer and the second layer is improved. Becomes weak, and the problem of delamination occurs. Here, since the bond between the first layer and the second layer is bonded by the adhesion between the resins, the adhesion between the resin layers not including the filler is stronger. That is, if a filler intervenes at the interface between the first layer and the second layer, the area of the resins that are in close contact with each other by the amount of the filler decreases, and the adhesion between the resin layers decreases. It is thought that it will lead to.

  The synthetic resin molded article having a two-layer structure for cost reduction as described above has a surface layer made of an expensive synthetic resin composition and a back layer made of an inexpensive synthetic resin composition. It is efficient from the viewpoint of cost to use a resin layer. However, if the material composition of the front surface layer and the back surface layer is made different in this way, the linear expansion coefficients of the two differ. For this reason, when heat is applied to the synthetic resin molded product, there arises a problem that warpage occurs due to a difference in expansion coefficient.

  The present invention has been made in view of the above problems, and the object of the present invention is to prevent delamination and warpage even in a synthetic resin molded product having a plurality of layer structures. Another object of the present invention is to provide a synthetic resin molded article and a method for producing the same.

  In order to solve the above-mentioned problems, the synthetic resin molded product and the manufacturing method thereof according to the present invention have the following configuration.

  That is, the synthetic resin molded product according to the first aspect of the present invention is the synthetic resin molded product 7 having a three-layer structure in which the intermediate layer 77 is provided between the outer surface layers 76. The outer surface layer 76 laminated on both sides of the intermediate layer 77 is made of a synthetic resin composition filled with a filler 78, and the intermediate layer 77 is one of the outer surface layers 76 on both sides of the intermediate layer 77. The outer surface layer 76 is impregnated and cured in the nonwoven fabric 6 without including the filler 78.

  With this configuration, the synthetic resin molded article 7 having a three-layer structure in which the intermediate layer 77 is interposed between the outer surface layers 76 does not include the filler 78 between the outer surface layers 76 including the filler 78. An intermediate layer 77 made of a resin layer is interposed. Further, the outer surface layer 76 becomes a high-strength resin layer containing the filler 78, and the intermediate layer 77 becomes a flexible resin layer not containing the filler 78.

  The synthetic resin molded product manufacturing method according to claim 2 is a manufacturing method for manufacturing the synthetic resin molded product 7 according to claim 1. The movable mold 2, which is movable with respect to the fixed mold 1, has a first molding position for forming the first cavity 41, a second molding position for forming the second cavity 42, and a mold release position. It can be moved between. The first cavity 41 is formed by positioning the movable mold 2 at the first molding position, and the nonwoven fabric 6 is disposed along the movable mold 2 in the first cavity 41. In this state, the first synthetic resin composition 71 filled with the filler 78 is injected into the first cavity 41, and the nonwoven fabric 6 is impregnated with the resin without the filler 78. Thereafter, the movable mold 2 is moved to the second molding position to form a second cavity 42 in which the nonwoven fabric 6 is left on the surface facing the movable mold 2. In this state, the second cavity 42 is formed in the second cavity 42. The second synthetic resin composition 72 filled with the filler 78 is injected. Thereafter, the movable mold 2 is released to obtain a synthetic resin molded product 7 having a three-layer structure.

  With this configuration, the first synthetic resin composition 71 is injected into the first cavity 41 in which the nonwoven fabric 6 is disposed along the movable mold 2, and the filler 78 is not put into the nonwoven fabric 6. When the resin is impregnated, a resin layer not including the filler 78 is formed. When the second synthetic resin composition 72 is injected into the second cavity 42 in this state, the second synthetic resin composition 72 is in close contact with the intermediate layer 77 not filled with the filler 78. Then, the synthetic resin molded article 7 having a three-layer structure in which the outer surface layer 76 becomes a high-strength resin layer containing the filler 78 and the intermediate layer 77 becomes a flexible resin layer not containing the filler 78 is manufactured. The

  In the synthetic resin molded product of the present invention, the intermediate layer 77 is formed by impregnating the nonwoven fabric 6 with the resin of any one of the outer surface layers 76 and then curing, so that the one outer surface is formed. The adhesion between the layer 76 and the intermediate layer 77 is strengthened by the anchor effect. Further, since the intermediate layer 77 does not contain a filler, the adhesion with the other outer surface layer 76 is also strong. For this reason, even if it is a synthetic resin molded product of a three-layer structure, delamination can be prevented.

  Further, in the synthetic resin molded product of the present invention, the outer surface layer 76 is a high-strength resin layer containing a filler, and the intermediate layer 77 is a flexible resin layer containing no filler, so that warpage occurs. Even in this case, the flexible intermediate layer 77 can absorb the difference in the linear expansion coefficient of the outer surface layer 76. For this reason, even if it is a synthetic resin molded product having a three-layer structure, it is possible to prevent warping.

It is a schematic sectional drawing of the synthetic resin molded product of one Embodiment of this invention. It is a schematic sectional side view for demonstrating the manufacturing method same as the above, (a)-(e) is a figure for demonstrating the manufacturing process of the manufacturing method. It is a schematic sectional side view just after inject | pouring the 1st synthetic resin composition same as the above. It is sectional drawing seen from D (FIG. 2 (a)) of the metal mold | die apparatus in FIG. 1 same as the above.

  The present invention will be described below with reference to the accompanying drawings.

  As an example of the synthetic resin molded product 7 of the present invention, a resin molded product having a three-layer structure as shown in FIG. 1 is used in the present embodiment.

  The synthetic resin molded product 7 can be exemplified by an artificial marble counter 7a as an example. As shown in FIG. 1, the synthetic resin molded product 7 includes a surface layer 73 as an outer surface layer 76 made of the first synthetic resin composition 71 and an outer surface layer 76 made of the second synthetic resin composition 72. A synthetic resin molded article 7 having a three-layer structure including a back surface layer 74, a surface layer 73, and an intermediate layer 77 integrated with the back surface layer 74. It has become.

  The surface layer 73 of this embodiment is a decorative surface of the artificial marble counter 7a. The surface layer 73 is formed from a first synthetic resin composition 71, and the first synthetic resin composition 71 is filled with at least a filler 78. More specifically, a filler 78 is filled in a thermosetting resin such as an epoxy, acrylic, or unsaturated polyester that is a main agent, and the filler 78 is preferably silica, calcium carbonate, aluminum powder, or the like. Used. The filler 78 improves the strength and heat resistance of the synthetic resin molded product 7. The synthetic resin composition 71 of this embodiment is configured by mixing a pattern material (not shown) into the synthetic resin composition 71 filled with such a filler 78. This pattern material is formed by making a sheet from a composition mainly composed of a resin mixed with a pigment, and then breaking the sheet into small pieces.

  On the other hand, the back surface layer 74 is formed from the second synthetic resin composition 72. The second synthetic resin composition 72 is also filled with a filler 78 in a thermosetting resin such as an epoxy or acrylic / unsaturated polyester as a main agent, and the filler 78 includes silica, calcium carbonate, Aluminum powder or the like is preferably used.

  The synthetic resin composition 71 that forms the front surface layer 73 is more expensive than the synthetic resin composition 72 that forms the back surface layer 74. That is, the first synthetic resin composition 71 is more expensive than the second synthetic resin composition 72 because the pattern material needs to be specially manufactured.

  The intermediate layer 77 is configured by curing the nonwoven fabric 6 impregnated with the resin of the first synthetic resin composition 71 constituting the surface layer 73. That is, the nonwoven fabric 6 does not include the filler 78. Therefore, the intermediate layer 77 has a lower elastic modulus than the front surface layer 73 and the back surface layer 74, and is a softer layer than the front surface layer 73 and the back surface layer 74.

  The nonwoven fabric 6 of the present embodiment uses a thermoplastic nonwoven fabric 6 and is configured such that the filler 78 does not pass through (see FIG. 3). Specifically, a nonwoven fabric 6 having a thickness of 250 μm is used, and a fiber diameter constituting the nonwoven fabric 6 is 20 to 30 μm, and a gap between fibers is 10 to 30 μm. In particular, it is preferable to use one having a gap between fibers less than the average particle diameter of the filler 78 (or less than the average particle diameter of the filler 78). Here, the point that the nonwoven fabric 6 is thermoplastic is not particularly limited.

  Note that the filler 78 included in the front surface layer 73 and the back surface layer 74 of the present embodiment has an average particle size of about 30 μm.

  By the way, in the synthetic resin molded product 7 having such a three-layer structure, the layers are bonded by the resins of the respective layers being in close contact with each other. That is, since the filler 78 does not contribute to the adhesion strength at the interface, if the filler 78 is present at the interface between the resin layers, the adhesion area is reduced, resulting in a decrease in adhesion between the layers. End up.

  Therefore, in the present embodiment, by using the nonwoven fabric 6 constituted by gaps between fibers so as not to pass the filler 78 contained in the first synthetic resin composition 71, only the resin (filler) is used for the nonwoven fabric 6. An intermediate layer 77 is formed by impregnating a resin not containing 78). Thereby, the amount of the filler 78 interposed at the interface between the back surface layer 74 and the intermediate layer 77 can be reduced. As a result, the synthetic resin molded product 7 of the present embodiment has a porous sheet (including the non-woven fabric 6 having a coarse mesh that allows the filler 78 to pass) interposed between the outer surface layers 76. The adhesion between the layers can be made even stronger than the synthetic resin molded product having a multilayer structure.

  Furthermore, the synthetic resin molded article 7 of the present embodiment has a thin surface layer 73 made of an expensive first synthetic resin composition 71 and a back layer 74 made of an inexpensive second synthetic resin composition 72. By forming it thick, the amount of the expensive first synthetic resin composition 71 used can be reduced and the cost can be reduced. At this time, even if the surface layer 73 is made of an expensive resin and the back surface layer 74 is made of an inexpensive resin, and the difference in the linear expansion coefficient between the two materials is produced, the filler 78 is changed. Since the elastic modulus of the intermediate layer 77 not included is smaller than the elastic modulus of the outer surface layer 76 including the filler 78, warping can be absorbed by the flexible intermediate layer 77. As a result, the occurrence of warpage can be suppressed. The elastic modulus of the intermediate layer 77 of this embodiment is 1/3 to 1/5 of the elastic modulus of the outer surface layer 76.

  In the above, the structure of the synthetic resin molded product 7 of this invention was demonstrated based on the artificial marble counter 7a. Hereinafter, a method for manufacturing an artificial marble counter as an example of the synthetic resin molded product 7 will be described.

  The manufacturing method of this embodiment manufactures an artificial marble counter by using the mold apparatus A shown in FIG.

  The mold apparatus A includes a mold 8 and a first nozzle 91 and a second nozzle 92 that inject synthetic resin compositions 71 and 72 into the mold 8. The mold 8 includes a fixed mold 1, a movable mold 2 that is movable with respect to the fixed mold 1, and a side mold 3. And this metal mold | die 8 is provided with the sheet | seat holding means 93 for hold | maintaining the outer peripheral edge part of the nonwoven fabric 6 of the said embodiment (FIG. 4).

  The fixed mold 1 is provided with a first molding portion 11 on the surface facing the movable mold 2. The first molding part 11 is constituted by a recess provided in the fixed mold 1. A side mold placement portion 12 on which the side mold 3 can be placed is provided in a portion around the first molding portion 11. A plate insertion recess 31 for holding a support plate 5 having an injection pressure receiving portion 51 which will be described later is formed in a part of the side mold placement portion 12 in the circumferential direction. The plate insertion recess 31 is formed by recessing a part of the side mold placement portion 12 in the circumferential direction. If the periphery of the first molding portion 11 is rectangular, the plate insertion recess 31 is rectangular. The plate insertion recess 31 is formed over the entire length of one side of the shape, or the plate insertion recess 31 is formed in a part of the side of the rectangular shape in the side direction. Further, when the periphery of the first molding part 11 is not rectangular, the plate insertion recess 31 is formed in a part of the periphery of the first molding part 11. Furthermore, a portion where the plate insertion recess 31 is not provided on the surface facing the side mold 3 provided around the first molding part 11 is a fixed mold side holding part 13.

  A first nozzle 91 is provided on the bottom surface of the first molding part 11 of the fixed mold 1. The first nozzle 91 is provided so as to face the injection pressure receiving portion 51 of the support plate 5 mounted in the plate insertion recess 31.

  The side mold 3 is detachably provided on an upper portion of the side mold placement section 12 provided around the first molding section 11 of the fixed mold 1. The side mold 3 is provided with a side mold side holding section 32 at the edge on the first molding section 11 side on the surface facing the fixed mold 1. Further, a side mold side sliding contact portion 33 is provided on a surface of the side mold 3 facing the movable mold 2 (a surface substantially perpendicular to the first molding portion 11). Furthermore, leakage prevention that prevents the injected synthetic resin composition from leaking to a part of the surface of the side mold 3 facing the movable mold 2 (surface substantially parallel to the first molding portion 11) is provided. Means 34 are provided. The leakage preventing means 34 of the present embodiment is configured by a bulging portion 34 a provided so as to be able to protrude and retract in the moving direction of the movable mold 2, and this bulging portion 34 a is directed from the side mold 3 to the movable mold 2. The movable tip 2 follows the movement of the movable die 2 in a state where the protruding tip is in contact with the movable die 2.

  As shown in FIGS. 2 and 4, a plate-like support plate 5 is mounted in the plate insertion recess 31 of the fixed mold 1. The support plate 5 has a plane perpendicular to the moving direction of the movable mold 2 in a state where the support plate 5 is mounted in the plate insertion recess 31. The support plate 5 protrudes into the concave portion of the first molding portion 11 on the injection pressure receiving portion 51 side, and the opposite end is fitted into the plate insertion recess 31 of the fixed mold 1. As shown in FIG. 4, the support plate 5 fitted in the plate insertion recess 31 has a surface (upper surface in FIG. 4) that does not face the plate insertion recess 31 as the fixed mold side holding portion 13. The surface that is flush with the side mold side holding portion 32 of the side mold 3 faces each other. In the present embodiment, the side mold side holding section 32, the fixed mold side holding section 13, and the support plate 5 constitute a sheet holding means 93 for holding the outer peripheral end of the nonwoven fabric 6.

  That is, the nonwoven fabric 6 is formed by covering the first mold portion 11 of the stationary mold 1 with the nonwoven fabric 6 on the stationary mold side holding portion 13 of the stationary mold 1 with the support plate 5 mounted in the plate insertion recess 31. The outer peripheral end of the is placed. In this state, the side mold 3 is closed with respect to the fixed mold 1, and the outer peripheral end of the nonwoven fabric 6 is sandwiched between the fixed mold side holding portion 13, the support plate 5, and the side mold side holding portion 32. In the closed state of the side mold 3 and the fixed mold 1, a part of the vicinity of the outer peripheral end of the nonwoven fabric 6 is in contact with the surface facing the movable mold 2 of the injection pressure receiving portion 51 of the support plate 5, A part of the nonwoven fabric 6 is supported on the surface of the support plate 5.

  In the movable mold 2, a second molded part 21 is formed at a portion facing the first molded part 11 of the fixed mold 1. The second molding part 21 has a movable mold side molding part 22 formed on a plane perpendicular to the moving direction of the movable mold 2 provided on the movable mold 2. It consists of a part of the mold 3. On the side surface of the movable mold 2 facing the side mold 3, a movable-type sliding contact portion 23 is provided. The movable mold 2 moves along the side mold 3, and when the movable mold 2 moves, the movable mold side sliding contact portion 23 and the side mold side sliding contact portion 33 are slidably contacted to guide the movement of the movable mold 2. Yes.

  A second nozzle 92 is provided on a part of the plane of the movable mold side molding portion 22 of the movable mold 2. Similar to the first nozzle 91, the second nozzle 92 is provided so as to face the injection pressure receiving portion 51 of the support plate 5 mounted in the plate insertion recess 31. And the second nozzle 92 are provided at positions facing each other. That is, the injection direction of the first nozzle 91 and the injection direction of the second nozzle 92 are installed so as to face each other to the support plate 5.

  A vent nozzle (not shown) is provided at the end opposite to the portion where the first and second nozzles 91 and 92 of the fixed mold 1 and the movable mold 2 are provided. By this vent nozzle, degassing can be performed when the synthetic resin composition is injected from the first and second nozzles 91 and 92.

  Such a movable mold 2 is movable between a first molding position for forming the first cavity 41, a second molding position for forming the second cavity 42, and a mold release position. Yes.

  The first molding position refers to the position of the movable mold 2 shown in FIG. When the movable mold 2 is positioned at the first molding position, the movable mold-side molding section 22 having a flat surface and the concave bottom surface of the first molding section 11 of the fixed mold 1 are separated from each other. A first cavity 41 is formed by 22 and the first molding part 11 of the fixed mold 1.

  The second molding position refers to the position of the movable mold 2 shown in FIG. The second molding position is a position obtained by moving the movable mold 2 by a predetermined distance from the first molding position in a direction away from the fixed mold 1. When the movable mold 2 is moved to the second molding position, a second cavity 42 is formed along the first cavity 41.

  The mold release position refers to the position of the movable mold 2 shown in FIG. This mold release position is a position where the movable mold 2 is moved further away from the fixed mold 1 from the second molding position. The synthetic resin molded product 7 can be taken out by positioning the movable mold 2 at the mold release position.

  Using the mold apparatus A configured as described above, an artificial marble counter as the synthetic resin molded product 7 is manufactured as follows.

  The outer peripheral end portion of the nonwoven fabric 6 configured not to pass the filler 78 of the first synthetic resin composition 71 is held by the sheet holding means 93. And as shown to Fig.2 (a), the movable mold | type 2 is located in a 1st shaping | molding position. When the movable die 2 is positioned at the first molding position, a first cavity 41 is formed. In the first cavity 41 in this state, the nonwoven fabric 6 is disposed along a surface facing the fixed mold 1 of the movable mold 2 in the first molding position. At this time, the support plate 5 is located closer to the stationary mold 1 than the nonwoven fabric 6. In this state, the first synthetic resin composition 71 is injected into the first cavity 41 from the first nozzle 91. Then, the injected first synthetic resin composition 71 hits the injection pressure receiving portion 51 of the support plate 5 as shown by the arrow in FIG. Flows along the surface. In this way, the first synthetic resin composition 71 is filled in the first cavity 41.

  At this time, as shown in FIG. 3, the nonwoven fabric 6 is configured to have a gap between fibers so as not to pass the filler 78 of the first synthetic resin composition 71. The resin is impregnated without the filler 78 of the synthetic resin composition 71.

  Next, in this state, the fixed mold 1 is heated to cure the first synthetic resin composition 71, and the first synthetic resin composition 71 is semi-cured or cured. At this time, the intermediate layer 77 made of the nonwoven fabric 6 impregnated with the resin is also semi-cured or cured.

  Thereafter, the movable mold 2 is moved from the first molding position to the second molding position while the fixed mold 1 is heated. When the movable mold 2 is positioned at the second molding position, the non-woven fabric 6 remains in the semi-cured or cured first synthetic resin composition 71 facing the movable mold 2. A second cavity 42 is formed along the first synthetic resin composition 71 on the movable mold 2 side of the nonwoven fabric 6. At this time, even if the portion on the movable mold 2 side of the first synthetic resin composition 71 is in a semi-cured state, the nonwoven fabric 6 is between the movable mold 2 and the first synthetic resin composition 71. Therefore, even if the movable mold 2 is moved, the semi-cured first synthetic resin composition 71 hardly adheres to the movable mold 2.

  If the movable mold 2 is moved when the first synthetic resin composition 71 is in a semi-cured state, the nonwoven fabric 6 does not pass the filler 78, but there is a gap of about 10 to 30 μm. Air bubbles contained in the synthetic resin composition 71 pass through the nonwoven fabric 6, and the air bubbles can be extracted into the second cavity 42. That is, since the air bubbles in the first synthetic resin composition 71 can be defoamed by the non-woven fabric 6, the first synthetic resin composition 71 is prevented from being cured while containing air bubbles. The strength after molding can be improved.

  Next, with the second cavity formed, the second synthetic resin composition 72 is injected from the second nozzle 92 into the second cavity 42. Then, the injected second synthetic resin composition 72 strikes the injection pressure receiving portion 51 of the support plate 5 as shown by the arrow in FIG. 2C and changes its direction so that the inside of the second cavity 42 is the surface of the nonwoven fabric 6. Flowing along.

  When the second synthetic resin composition 72 is injected into the second cavity 42, heating by the movable mold 2 as well as the stationary mold 1 is started, and synthesis is performed by heating from both sides of the movable mold 2 and the stationary mold 1. The resin composition is completely cured.

  When the synthetic resin composition is completely cured, heating of the fixed mold 1 and the movable mold 2 is stopped, and the movable mold 2 is moved to the mold release position to open the mold. Since the side mold 3 can be removed from the side mold placing portion 12 of the fixed mold 1 when the movable mold 2 is positioned at the mold release position, the side mold 3 is removed from the fixed mold 1. Then, since the cured synthetic resin composition can be removed from the fixed mold 1, the cured synthetic resin composition is removed from the fixed mold 1.

  Since the demolded cured synthetic resin composition had the outer peripheral end of the nonwoven fabric 6 held by the sheet holding means 93 during molding, the outer peripheral end held by the sheet holding means 93 of the nonwoven fabric 6 on the outer periphery. The part protrudes, and the part fitted in the plate insertion recess 31 of the support plate 5 is also in a protruding state. Therefore, first, the support plate 5 fixed between the first synthetic resin composition 71 and the nonwoven fabric 6 is extracted from the cured synthetic resin composition. When the support plate 5 is extracted, a groove 75 is formed at the tip of the cured synthetic resin composition. Therefore, the groove 75 portion is cut and removed together with a portion protruding outward from the outer peripheral end portion of the nonwoven fabric 6. In this way, the synthetic resin molded product 7 is completed.

  In the step of filling the first cavity 41 with the first synthetic resin composition 71, the nonwoven fabric 6 is disposed along the movable mold 2 and then the synthetic resin composition 71 is filled. Even if the first synthetic resin composition 71 remains in a semi-cured state, the movable mold 2 can be moved to the second molding position without attaching the first synthetic resin composition 71 to the movable mold 2. As a result, the synthetic resin molded article 7 can be manufactured in a shorter time than the conventional one that required time until the first synthetic resin composition 71 is completely cured after filling.

  By the way, if the 1st and 2nd synthetic resin composition 71,72 is inject | poured without arrange | positioning the nonwoven fabric 6, the 1st synthetic resin composition 71 and the 2nd synthetic resin composition 72 will be partly. The first synthetic resin composition 71 bites into the second synthetic resin composition 72, or the second synthetic resin composition 72 bites into the first synthetic resin composition 71. For this reason, the thickness of the surface layer 73 cannot be ensured to a constant thickness, and the back layer 74 may be located near the surface or the back layer 74 may be exposed on the surface depending on circumstances. However, in this embodiment, in the step of filling the second cavity 42 with the second synthetic resin composition 72, the nonwoven fabric 6 is left on the surface of the first synthetic resin composition 71 on the movable mold 2 side. Therefore, the second synthetic resin composition 72 can be filled without being affected by the injection pressure of the second nozzle 92 or the cured state of the first synthetic resin composition 71. Thereby, each thickness of the surface layer 73 formed by the 1st and 2nd synthetic resin composition 72 and the back surface layer 74 can be shape | molded according to a design dimension and fixed thickness.

  In the present embodiment, since the first and second nozzles 92 are injected toward the support plate 5, it is possible to prevent the nonwoven fabric 6 from being deformed by the injection pressure.

  Moreover, unlike the said embodiment, while using the transparent synthetic resin composition which used acrylic resin as the main ingredient for the surface layer 73, it can also be set as the structure which formed the decorative surface in the nonwoven fabric 6. FIG. According to such a synthetic resin molded product 7, by showing the decorative surface of the nonwoven fabric 6 through the surface layer 73, the synthetic resin molded product 7 having an unprecedented appearance and increasing the sense of depth can be produced. Can do.

  In the above embodiment, the first synthetic resin composition 71 may be the back layer 74 and the second synthetic resin composition 72 may be the surface layer 73.

6 Nonwoven fabric 7 Synthetic resin molded product 7a Artificial marble counter 73 Surface layer 74 Back surface layer 76 Outer surface layer 77 Intermediate layer 78 Filler

Claims (2)

A synthetic resin molded product having a three-layer structure in which an intermediate layer is provided between outer surface layers,
The outer surface layer laminated on both sides of the intermediate layer consists of a synthetic resin composition filled with a filler,
The intermediate layer is a synthetic resin molded product obtained by impregnating and curing a non-woven fabric without including a filler in any one of the outer surface layers on both sides of the intermediate layer. . A manufacturing method for manufacturing the synthetic resin molded article according to claim 1,
A movable mold that is movable with respect to the fixed mold moves between a first molding position that forms a first cavity, a second molding position that forms a second cavity, and a mold release position. It ’s free,
A first cavity is formed by positioning the movable mold in the first molding position, and the nonwoven fabric is disposed along the movable mold in the first cavity, and in this state, the filler is filled. Injecting the first synthetic resin composition into the first cavity, impregnating the resin without filling the nonwoven fabric,
Thereafter, the movable mold is moved to the second molding position to form a second cavity in which the nonwoven fabric is left on the surface facing the movable mold, and in this state, the second cavity is filled with a filler. Injecting a second synthetic resin composition,
Thereafter, a synthetic resin molded article having a three-layer structure is obtained by releasing the movable mold.

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