Skin for vacuum molding

Abstract

To provide a skin for vacuum molding capable of holding texture of a soft urethane foam and acquiring texture in which there is no running out feeling of polypropylene foam, and a production method of the same.SOLUTION: There is provided a skin for vacuum molding formed of: a skin formed of a polyvinyl chloride or olefinic thermoplastic elastomer; an urethane foam provided on a rear face of the skin; and a polypropylene foam crimped to the urethane foam.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vacuum forming skin that is applied to the surface of plastic or the like by vacuum forming. [Background technology]

[0002] When producing interior materials for use in the interior of an automobile, a base material made of plastic is covered with a decorative skin by vacuum forming. The material of the vacuum forming skin used in such vacuum forming is a surface skin made of PVC or TPO laminated with polypropylene foam (e.g., electron beam cross-linked polypropylene foam). Such vacuum forming skin laminated with polypropylene foam has an advantageous effect of not feeling like it is bottoming out when pressed, since polypropylene foam has high restorability. However, there is a problem that the texture is hard to the touch and does not have a luxurious feel, compared to a skin laminated with soft or semi-rigid urethane foam, for example (Patent Document 1).

[0003] On the other hand, a skin made of soft or semi-rigid urethane foam has a soft texture and a luxurious feel, but has the problem that the soft texture makes the skin feel like it is bottoming out. Also, when used in vacuum molding, the urethane foam will succumb to the vacuum pressure and collapse, making it difficult to cover with vacuum molding, and there is a problem that it must be applied by hand. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-247266 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and has as its object to provide a vacuum forming skin that is applied to a substrate during vacuum forming, and that retains the texture of a soft or semi-rigid urethane foam while eliminating the bottoming-out feeling of polypropylene foam, and a method for producing the same. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means.

[0007] The vacuum forming skin according to the present invention is A skin made of synthetic resin or woven fabric; A soft or semi-rigid urethane foam provided on the back surface of the skin; The polyurethane foam is characterized in that it is made of polypropylene foam or polyethylene foam compressed onto the polyurethane foam.

[0008] The vacuum forming skin of the present invention is formed in a sheet shape in which a soft or semi-rigid urethane foam is sandwiched between the skin and a layer of polypropylene foam or polyethylene foam. Therefore, when pressed with a finger from the skin side, a soft texture can be obtained because the skin is immediately behind the urethane foam, and a polypropylene foam or polyethylene foam layer is located behind the urethane foam, preventing a bottoming out feeling. In addition, during vacuum forming, the polypropylene or polyethylene layer is pulled toward the substrate by vacuum forming, and the polypropylene or polyethylene foam layer reduces the pressure drop caused by the vacuum reaching the urethane foam side, so that even when a soft urethane foam is used, the urethane foam can be covered by the substrate with reduced compression.

[0009] In the vacuum forming skin of the present invention, the polypropylene foam or polyethylene foam may be characterized in that the surface to be pressed against the urethane foam is frame-treated. By framing the surface of the polypropylene foam or polyethylene foam, it is possible to press the polypropylene foam or polyethylene foam against the urethane foam, which has been considered difficult to achieve in the past.

[0010] Furthermore, in the vacuum molding skin according to the present invention, the polypropylene foam or polyethylene foam may be characterized in that the surface to be pressed against the urethane foam is Itro-treated. By carrying out the Itro treatment, the polypropylene foam or polyethylene foam and the urethane foam can be more firmly pressed against each other than by frame treatment.

[0011] Furthermore, in the vacuum forming skin according to the present invention, the urethane foam may be characterized in that the surface thereof that is to be pressed against the polypropylene foam or polyethylene foam is frame-treated. By subjecting the urethane foam side to frame treatment as well, the polypropylene foam or polyethylene foam and the urethane foam can be more firmly pressed against each other.

[0012] Furthermore, in the vacuum forming skin according to the present invention, the bonding surfaces of the urethane foam and the polypropylene foam or the polyethylene foam may be bonded with a hot melt. By using a hot melt, the polypropylene foam or the polyethylene foam and the urethane foam can be bonded more firmly with each other.

[0013] Furthermore, in the vacuum forming skin of the present invention, the polypropylene foam or polyethylene foam may be a closed-cell foam. By using a closed-cell foam, the low vacuum pressure can be blocked by the polypropylene foam or polyethylene foam and prevented from reaching the urethane foam.

[0014] The present invention also provides a method for producing a vacuum forming skin, which comprises a skin made of synthetic resin or woven fabric, a urethane foam provided on the back surface of the skin, and a polypropylene foam or polyethylene foam bonded to the urethane foam, the method comprising the steps of: A vacuum forming skin is produced by subjecting the surface of the polypropylene foam or the polyethylene foam to a framing process and then bonding a urethane foam to the surface.

[0015] Furthermore, the method for producing a vacuum forming skin according to the present invention may be characterized in that the surface of the polypropylene foam or polyethylene foam is framed, the surface of the urethane foam is framed, and the framed surface of the polypropylene foam or polyethylene foam and the framed surface of the urethane foam are pressure-bonded together.

[0016] Furthermore, in the method for producing a vacuum forming skin according to the present invention, The surface of the polypropylene foam or polyethylene foam may be ITO-treated, and the surface of the urethane foam may be frame-treated, and the ITO-treated surface of the polypropylene foam or polyethylene foam, the frame-treated surface of the polypropylene foam or polyethylene foam, and the frame-treated surface of the urethane foam may be bonded together under pressure.

[0017] Furthermore, in the method for producing a vacuum forming skin according to the present invention, the surface of the polypropylene foam or the polyethylene foam and the urethane foam may be bonded together using a hot melt. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view of a vacuum forming skin 100 according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The skin-coated product according to the embodiment will be described in detail below with reference to the drawings. Note that the embodiment and drawings described below are merely examples of some of the embodiments of the present invention, and are not intended to limit the present invention to these configurations. The present invention may be modified as appropriate without departing from the scope of the present invention. In each drawing, corresponding components are designated by the same or similar reference numerals.

[0020] As shown in FIG. 1, the vacuum forming skin 100 of the present invention comprises, from the surface layer, a skin 10 made of polyvinyl chloride resin or olefin thermoplastic elastomer, a urethane foam 20 provided on the back surface of the skin 10, and a polypropylene foam or polyethylene foam 30 laminated on the urethane foam 20 by pressure bonding.

[0021] The skin 10 is a sheet-like member made of synthetic resin or woven fabric. Examples of synthetic resin include sheets made of polyvinyl chloride resin (PVC), olefin-based thermoplastic elastomer (TPO), thermoplastic polyurethane elastomer (TPU), etc. Surface treatment (textured processing, embossing) is not particularly limited and can be selected appropriately. The vinyl chloride resin is not limited to polyvinyl chloride, and may be various copolymers mainly made of vinyl chloride and blends with other resins. The thickness of the vinyl chloride resin sheet is preferably in the range of 0.3 mm to 2.0 mm, which is suitable for vacuum molding without impairing the feel of the skin 10. More preferably, it is in the range of 0.5 mm to 1.0 mm.

[0022] The urethane foam 20 is a soft urethane foam or a semi-rigid urethane foam. The urethane foam 20 may be made of slab foam or molded foam. The slab foam is a molding method in which a raw material mixture containing polyol, polyisocyanate, a catalyst, a foam stabilizer, etc. is poured into a heater without being put into a mold, and the foamed and cured urethane foam 20 is molded by cutting or the like. The molded foam is a molding method in which the raw material mixture is poured into a predetermined mold, molded, and heated together with the mold. The thickness of the urethane foam 20 is preferably in the range of 1.0 mm to 5.0 mm. As described later, the urethane foam may be laminated and foamed when it is molded with a skin.

[0023] The polypropylene foam or polyethylene foam 30 preferably has a thickness in the range of 1.0 mm to 3.0 mm. The polypropylene foam or polyethylene foam 30 is preferably a closed-cell foam. If the foam is an open-cell foam, when vacuum molding is performed on the skin substrate, the low pressure caused by the vacuum passes through the polypropylene foam or polyethylene foam 30 and reaches the urethane foam 20, causing the urethane foam 20 to shrink. By using a closed-cell foam, the low pressure of the vacuum can be blocked by the polypropylene foam or polyethylene foam 30, preventing it from reaching the urethane foam 20.

[0024] The vacuum forming skin 100 according to the present invention having the above-mentioned configuration is produced as follows. Note that the following explanation shows an example in which polypropylene foam 30 is used, but polyethylene foam can also be produced by a similar production method.

[0025] (First production method) First, a laminate of the skin 10 and the urethane foam 20 is produced. The laminate of the skin 10 and the urethane foam 20 may be laminated by bonding with an adhesive or the like after the skin 10 and the urethane foam 20 are produced, or may be laminated by pouring a urethane foam mixture into the skin 10 and foaming it, and forming the skin 10 and the urethane foam 20 into a plate-like shape bonded together. Then, the surface of the polypropylene foam 30 is frame-treated. The frame treatment is a treatment in which oxygen in the air is converted into plasma by burning a mixture of combustion gas and air, and the oxygen plasma is applied to the object to be treated (polypropylene foam 30) to make the surface of the base material hydrophilic. Then, the surface of the frame-treated polypropylene foam 30 and the surface of the urethane foam 20 of the laminate of the skin 10 and the urethane foam 20 are heat-treated and pressure-bonded to form a finished product. By this production method, the urethane foam 20 and the polypropylene foam 30 can be pressure-bonded and laminated, which is very difficult.

[0026] (Second production method) The second manufacturing method is a method of performing an Itro treatment instead of the flame treatment of the surface of the polypropylene foam 30 in the first manufacturing method. The Itro treatment is a surface treatment method in which a silane compound or the like is introduced into a fuel gas to form a flame, and the surface of the polypropylene foam 30 is treated using the flame, whereby a large number of nano-level particles mainly composed of SiO2 are formed on the surface of the treated polypropylene, and together with the oxidation reaction caused by the flame (frame), the adhesion with the urethane foam 20 can be significantly improved. Then, the surface of the Itro-treated polypropylene foam 30 and the surface of the urethane foam 20 of the laminate of the skin 10 and the urethane foam 20 are heat-treated and pressure-bonded together to form a finished product. This manufacturing method makes it possible to more effectively pressure-bond and laminate the urethane foam 20, which is very difficult.

[0027] (Third production method) In the third manufacturing method, the surface of the urethane foam 20 in the laminate of the skin 10 and the urethane foam 20 produced in the first or second manufacturing method is frame-treated, and then bonded to the surface of the polypropylene foam 30. This manufacturing method makes it possible to more effectively pressure-laminate the urethane foam 20 and the polypropylene foam 30, which is very difficult to do.

[0028] (Fourth production method) In the fourth manufacturing method, when bonding the laminate of the skin 10 and the urethane foam 20 to the surface of the polypropylene foam 30 in the first to third manufacturing methods, the surfaces of either the laminate of the skin 10 and the urethane foam 20 or the polypropylene foam 30 are subjected to a hot melt treatment before bonding. This manufacturing method makes it possible to more effectively pressure-laminate the urethane foam 20 and the polypropylene foam 30, which is very difficult to do.

[0029] When the vacuum forming skin 100 produced by the above method is vacuum formed onto a substrate, the vacuum side surface that is bonded to the substrate becomes the polypropylene foam 30, so that the urethane foam 20 can be prevented from being crushed by the vacuum. Therefore, the urethane foam 20 can be covered onto the substrate without being crushed. Therefore, the skin can be made to have a soft texture due to the texture of the soft urethane foam 20 directly below the skin, while the polypropylene foam 30 arranged behind it prevents the user from feeling like they are hitting the bottom.

[0030] It goes without saying that the present invention is not limited to the above-described embodiments, and can be embodied in various forms within the technical scope of the present invention. [Industrial Applicability]

[0031] As shown in the above-described embodiment, the present invention can be industrially utilized as a method for manufacturing automobile-related parts. [Explanation of symbols]

[0032] 10...Skin, 20...Urethane foam, 30...Polypropylene foam, 100...Skin for vacuum molding

Claims

1. A skin made of synthetic resin or woven fabric; A soft or semi-rigid urethane foam provided on the back surface of the skin; A vacuum molding skin comprising polypropylene foam or polyethylene foam pressed onto the urethane foam.

2. 2. The vacuum forming skin according to claim 1, wherein the polypropylene foam or the polyethylene foam has a frame-treated surface that is pressed against the urethane foam.

3. 2. The vacuum forming skin according to claim 1, wherein the surface of said polypropylene foam or said polyethylene foam that is to be pressed against said urethane foam is subjected to an Itro treatment.

4. 4. The vacuum forming skin according to claim 2, wherein the surface of said urethane foam that is pressed against said polypropylene foam or said polyethylene foam is frame-treated.

5. 4. The vacuum molding skin according to claim 1, wherein the pressure-bonding surfaces of the urethane foam and the polypropylene foam or the polyethylene foam are bonded with a hot melt.

6. 4. The vacuum forming skin according to claim 1, wherein the polypropylene foam or the polyethylene foam is a closed-cell foam.

7. A method for producing a vacuum forming skin, the method comprising: a skin made of synthetic resin or woven fabric; a urethane foam provided on the back surface of the skin; and a polypropylene foam or polyethylene foam bonded to the urethane foam, the method comprising the steps of: A method for producing a skin for vacuum molding, comprising the steps of: framing the surface of the polypropylene foam or the polyethylene foam; and then pressing the urethane foam onto the surface of the polypropylene foam or the polyethylene foam.

8. A method for producing a vacuum forming skin, the method comprising: a skin made of synthetic resin or woven fabric; a urethane foam provided on the back surface of the skin; and a polypropylene foam or a polyethylene foam pressed onto the urethane foam, the method comprising the steps of: A method for producing a skin for vacuum molding, comprising framing a surface of the polypropylene foam or the polyethylene foam, framing a surface of a urethane foam, and pressing the framed surface of the polypropylene foam or the polyethylene foam and the framed surface of the urethane foam together.

9. A method for producing a vacuum forming skin, the method comprising: a skin made of synthetic resin or woven fabric; a urethane foam provided on the back surface of the skin; and a polypropylene foam or polyethylene foam pressed onto the urethane foam, the method comprising the steps of: A method for producing a skin for vacuum molding, comprising the steps of: subjecting a surface of the polypropylene foam or polyethylene foam to an Itro treatment; and subjecting a surface of the urethane foam to a frame treatment; and pressing together the Itro-treated surface of the polypropylene foam or polyethylene foam, the frame-treated surface of the polypropylene foam or polyethylene foam, and the frame-treated surface of the urethane foam.

10. 10. The method for producing a vacuum forming skin according to claim 7, wherein a surface of the polypropylene foam or the polyethylene foam and the urethane foam are bonded together using a hot melt.

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