JP3204806B2 - Manufacturing method of molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the possibility of touching molded articles such as automobile interiors, housings for office automation (OA) equipment and home appliances, and stationery, sanitary goods, daily necessities, and interior materials for building materials. The present invention relates to a method for producing a molded product having characteristics such as scratch resistance, which is suitable for use in a certain site.

[0002]

2. Description of the Related Art Heretofore, as a sheet used for such a molded article, a sheet comprising a polyvinyl chloride layer having an embossed surface and, if necessary, a foam layer laminated on the back side is used. I have been.

[0003] However, such a sheet using polyvinyl chloride lacks sheet flexibility and requires a plurality of steps in its production.
As described in Japanese Patent Publication No. 1-14023, a covering sheet is proposed in which a polyethylene or polypropylene foam layer is laminated on the back side of a polyolefin-based thermoplastic elastomer layer whose surface is embossed. .

[0004]

[Problems to be solved by the invention]
The sheet using the olefin-based elastomer described in Japanese Patent No. 4023 has a drawback that scratch resistance is poor in terms of imparting surface contact resistance to the sheet.

Further, in order to impart scratch resistance to a sheet, as described in JP-A-63-272547,
There is a method of coating the top coat layer in a later step, but this method requires a booth for drying the organic solvent, and has problems in working environment, pollution, and health and safety.

Further, since these sheets are inferior in extensibility of the entire sheet, molded articles having irregularities or curved surfaces,
In particular, in the case of a deep drawn product, it may not be possible to attach a sheet to the entire adherend.

An object of the present invention is to improve the above-mentioned problems,
An object of the present invention is to provide a method for producing a molded article having excellent scratch resistance and flexibility.

[0008]

[0009]

Means for Solving the Problems To achieve such an object
To conclude, the first method for producing a molded article of the present invention is a method for producing glass molded articles.
Transition point (Tg) is -50 to 20 ° C, JIS A hardness is 50
And a surface layer composed mainly of a thermoplastic urethane elastomer and 98, the contact adhesive polymer layer, thermoplastic elastomer
And a base layer mainly composed of
The coating sheet in the order of this are integral product layer, the step of the surface layer is introduced into the mold so as to be positioned on the mold surface of the mold, and the molding resin is supplied to the gold inner mold And integrating the coating sheet with the covering sheet.

[0010] The second method for producing a molded article of the present invention is characterized in that
Transition point (Tg) is -50 to 20 ° C, JIS A hardness is
And a surface layer made of a thermoplastic urethane elastomer 50-98 as a main component, a contact adhesive polymer layer, a thermoplastic gill
The base layer mainly composed of stoma is used for co-extrusion molding.
The coating sheet are integral product layer in this order Yoriko, preformed pneumatically molding is introduced into the mold so that the surface layer is located on the mold surface of the mold, the mold surface of the mold And a step of supplying a molding resin into the mold to integrate the molding resin with the covering sheet.

The details are as follows.

First, a first manufacturing method of the present invention will be described.

[0013] cover sheet used in the first production method of the present invention has a surface layer, contact adhesive polymer layer, and a substrate layer.

The thermoplastic urethane elastomer used for the above surface layer has rubber elasticity at normal temperature, is plasticized at high temperature and can be formed into various shapes, and generally has entropic elasticity in the molecule. As a rubber component (soft segment) having, polyether, polyester,
It has polycarbonate and has a segment composed of urethane bonds as a molecular constraint component (hard segment) for preventing plastic deformation. In some cases, it has a crosslinked structure within the moldable range, but does not have a wide-range three-dimensional network structure.

The above thermoplastic urethane elastomer preferably has a glass transition point (Tg) in the range of -50 to 20 ° C. in order to exhibit scratch resistance, and the higher the molecular weight, the higher the rigidity. Preferably, the weight average molecular weight is in the range of 20,000 to 3,000,000. The hardness varies depending on the hardness and thickness of the base material layer and the foam layer laminated on the back surface layer, but is preferably 50 to 98 in JIS A hardness .

The resin constituting the base material layer is flexible.
Thermoplastic elastomer to give a soft touch
Are used, and they are particularly excellent in moldability and cost.
It is preferable to use a olefin-based thermoplastic elastomer.

For example, a polyolefin-based thermoplastic elastomer excellent in moldability and cost is one having polypropylene as a hard segment and having ethylene as a soft segment, or one having a small amount of a diene component together with ethylene ( EPM, EP in order
DM, generically referred to as EPR), those obtained by blending them, and those partially crosslinked by further adding an organic peroxide thereto can be used.

The hardness of these thermoplastic polyolefin elastomers varies depending on the feel of the surface of the coating sheet to be obtained, but is generally 50 to 98 in JIS A hardness.
Is preferable. In addition, a polyolefin-based resin such as polypropylene or LLPE (linear low-density polyethylene) may be further contained in the base material layer in order to improve the stretch moldability of the thermoplastic polyolefin-based elastomer.

[0019] As the material constituting the contact adhesive polymer layer, adhesion of the polymer to be compatible with the resin constituting the substrate layer is used. As such a polymer, a polymer containing a compound having a functional group such as a hydroxyl group, an amide group, an epoxy group, a carboxylic acid group, or a carboxylic ester group in a main chain or a side chain is preferably used. Among these functional groups, a polymer having a carboxylic acid is particularly preferred,
As the amount of the carboxylic acid, the acid value of the polymer is 1 to 30 m.
g KOH / g is preferred. The molecular weight of the polymer is usually from 2,000 to 500,000.

For example, when a polyolefin-based thermoplastic elastomer is used for the substrate layer, a chlorinated polyolefin, an ionomer resin (ethylene-methacrylic acid copolymer metal salt), an acid-modified SBS (styrene-butadiene- Styrene copolymer), acid-modified SE
BS (styrene-ethylene-butadiene-styrene copolymer) or the like is preferably used, and in particular, itself has properties as an elastomer (JIS A hardness of about 50 to 98).
Are preferably used.

A foam layer is laminated on the covering sheet used in the present invention, if necessary. Examples of the material constituting the foam layer include polyolefin resins such as polypropylene and polyethylene, polystyrene resins such as polystyrene and styrene-maleic anhydride copolymer, polyurethane resins, polyvinyl chloride resins, and various thermoplastic elastomer resins. And a foamable resin material. The foaming efficiency of these foams is preferably about 5 to 50 times, and more preferably about 20 to 50 times, in order to exhibit cushioning properties and soft touch feeling.

[0022] The coating sheet is, between the front surface layer and the base layer, is obtained by coextruding a contact adhesive polymer layer simultaneously (3 layer extrusion).

[0023] Coextrusion molding uses two or more extruders,
This is a method of combining extruded resins into one to make a multi-layer product. The joining method by the co-extrusion includes a feed block method, a multi-manifold method, and a multi-throttle die method. The feed block method is a method of joining by a special block attached just before entering a die, and is also called a black box method. The multi-manifold method is a method in which the number of manifolds in the die is equal to the number of layers. The multi-throttle die method is a method in which the flows are separated in the die and are brought into close contact with each other immediately after leaving the die.

Although any of these methods can be used to produce a sheet-like laminate, a multi-manifold method is preferred in order to make the thickness accuracy of each layer accurate. Further, the co-extruded sheet-like laminate is cooled through a roll immediately after extruding the material. At this time, the thermoplastic urethane elastomer layer (surface layer) side has a roll temperature of the softening point of the thermoplastic urethane elastomer. Below, preferably room temperature to 10
At 0 ° C., the surface of the sheet-shaped laminate can be embossed by passing through an embossing roll having a roughened surface.

On the other hand, there is also a method in which a sheet-like material such as a foamed sheet is extruded from another extruder immediately before the extruded sheet-like laminate passes through a roll, and pressure-bonded and integrated by a roll.

When a foamed layer is formed by laminating a foamed sheet on the coextruded sheet-like laminate, the foamed sheet is placed on the base layer side of the extruded and molten sheet-like laminate. It is convenient to pass between a pair of rolls in a laminated state, and fuse and integrate the layers (extrusion lamination method).

When the adhesion between the base material layer and the foam layer is poor, a primer layer may be provided in advance on the surface of the foam layer (the surface on the base material layer side).

The coating sheet used in the present invention may further contain, if necessary, materials such as coloring agents such as pigments and dyes, antioxidants, ultraviolet absorbers and hindered amines.

As the coloring agent, pigments and dyes used in paints can be used. Examples of the pigment include titanium oxide, iron oxide, carbon black, cyanine pigment, and quinacridone pigment. Dyes include azo dyes, anthraquinone dyes, indigoid dyes, and stilbenzene dyes. Further, metal powder such as aluminum flake, nickel powder, gold powder, silver powder and the like may be used as the coloring agent. These materials are preferably fine particles as much as possible.
The amount of the coloring agent, when used a colorant having a high concealing property, 100 parts by weight of the solid content of the resin is preferably in the range of 2 to 40 by weight part.

In order to impart various functions to the coating sheet of the present invention, various functionalizing agents may be added.
The above various functional imparting agents, conductive material, anti-condensation agent,
There are photochromic compounds and rust inhibitors.

Further, in order to enhance the design of the sheet, a pattern such as printing may be applied. In this case, the printing is preferably provided on the back surface of the surface layer (on the base material layer).

The thickness of the thus obtained covering sheet used in the present invention varies depending on the sheet structure.
Generally, the thermoplastic urethane elastomer layer as the surface layer is 5 to 500 μm, and the base material layer is 200 to 3000 μm.
m, the thickness of the foam layer is preferably about 1000 to 3000 μm.

The molding resin used in the present invention includes:
Any material that is normally molded can be used.
For example, ABS (acrylonitrile-butadiene-styrene copolymer), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, acrylic resin, polyetherimide, polyphenylene sulfide, nylon, or a thermoplastic elastomer. Examples include fibers and fibers having an inorganic filler.

On the other hand, when a foam layer is used, the foam layer and the molding resin are made of the same type of resin (for example, the foam layer is made of PP foam, in order to ensure the close contact between the foam layer and the molding resin). Preferably, the molding resin comprises PP). When the adhesion between the foam layer and the molding resin is poor, it is preferable to provide an adhesive layer (primer layer) on the side of the foam layer that contacts the molding resin.

In order to obtain a molded article using the above-mentioned covering sheet, the above-mentioned covering sheet is introduced into a mold so that the surface layer is positioned on the mold surface side of the mold, and the molded article is formed into a molded article body. The resin is molded by injection molding or stamping molding, and at the same time, the sheet is integrated with the molded article body.

The stamping molding is a method in which a molding resin is introduced into a mold and then the mold is closed and molded.
Injection molding is a method of molding by introducing a molding resin after closing a mold.

In the first manufacturing method of the present invention, when the sheet is formed, the sheet is not stretched much, and the sheet does not need to be pneumatically formed in advance.

The obtained molded article may be laminated on another article (core material) via an adhesive or the like. As a core material,
The materials used as the molding resin can be used. Further, a sheet in which a layer similar to the above-described core material is further laminated on the foam layer may be used.

Next, a second manufacturing method of the present invention will be described.

The covering sheet and the molding resin used in the second production method of the present invention are the same as the above-mentioned covering sheet and the molding resin.

In order to obtain a molded article using the above-mentioned covering sheet, the above-mentioned covering sheet is introduced into a mold so that the surface layer is located on the mold surface side of the mold, and preformed by pneumatic molding. A molding resin to be a molded article main body is molded by injection molding or stamping along the mold surface, and at the same time, a covering sheet is integrated with the molded article main body. The preformed covering sheet may be taken out of the mold once and then along the mold surface.

In order to obtain a molded article by using the above-mentioned covering sheet, the above-mentioned covering sheet is preliminarily pneumatically molded (the same mold surface as that of the mold when the molding resin is supplied and integrated). Preformed in a mold having a mold), and the preformed sheet is introduced into the mold so that the surface layer is positioned on the mold surface side of the mold, and the molding resin serving as a molded product body is injection-molded. Alternatively, the sheet is integrated with the surface of the molded article at the same time as the sheet is molded by stamping molding.

The obtained molded article may be laminated on another article (core material) via an adhesive or the like. As a core material,
The materials used as the molding resin can be used. Further, a sheet in which a layer similar to the above-described core material is further laminated on the foam layer may be used.

Incidentally, the pneumatic forming means a forming method using vacuum forming or compressed air forming, or a combination thereof. For preforming, a method of simultaneously performing preforming and injection molding using a mold for resin molding such as injection molding,
In addition, there is a method using a sheet forming die different from that. During pneumatic molding, the sheet is usually heated by a separate heating device on both the surface layer side and the foam layer side.

In these moldings, a male mold or a female mold can be used as a mold. When a female mold is used, if the embossed pattern is applied to the surface of the mold, the embossed pattern is transferred to the sheet surface by molding. In the case where the drawing of the sheet at the time of molding is large, a method of using a plug at the time of pneumatic molding (plug assist molding) or match molding may be performed.

The apparatus actually used and a specific method of manufacturing a molded product will be described in Examples.

[0047]

The coating sheet used in the present invention is made of thermoplastic urethane.
Surface layer mainly composed of tan elastomer and adhesion
Polymer layer and thermoplastic elastomer
The base material layer is laminated and integrated in this order by co-extrusion molding.
It is a sheet-like laminate obtained. Such a covering sheet is
In addition to simplifying the lamination process, environmental pollution and
No health and safety issues. In addition, lamination by co-extrusion molding
The integrated lamination method is that each layer is placed in a co-extrusion mold.
Molded through the same heat history, resulting in uniform molding strain
The shrinkage stress generated when the coating sheet is heated
Occurs evenly on the surface, so that
When a shape is manufactured by thermoforming, each layer deforms evenly
In addition, the adhesive strength of each layer is properly secured. Further , according to the present invention, the surface layer of the coating sheet used has a glass transition.
Point (Tg) is -50 to 20 ° C, JIS A hardness is 50 to
Since the thermoplastic urethane elastomer 98 is a main component, a molded article having excellent scratch resistance and flexibility can be obtained. Sa
Furthermore, in the present invention, it is possible to easily form the coating sheet in a mold having irregularities and a curved surface while conforming to the shape of the mold, thereby producing a molded product having a desired shape.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

The number of parts indicates the number of parts by weight on a solid basis.

The method for preparing the covering sheet will be described.

<Sheet A> Surface layer: thermoplastic urethane elastomer resin (manufactured by Nippon Miractran Co., Ltd., E375NMAT, JISA hardness 7)
5, glass transition point: -30 ° C.) contacting adhesive polymer layer: acid modified SEBS (Asahi Chemical Industry Co., Ltd., Tuftec M1943, acid value 10 mg CH
₃ ONa / g) Base material layer: 80 parts of thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., Mirastomer 8030N) in which 20 parts of LLPE is pellet-blended The above three layers are multi-layered as shown in FIG. manifold type die, the extruder 1a (surface layer) 40 .phi, 1b (contact adhesive
Extruded with a three-layer co-extrusion apparatus 2 (each manufactured by Plastics Engineering Laboratory) having a functional polymer layer ) of 40φ and 1c (base layer) of 50φ. Extruder 1a, 1b, 1c each resin temperature of the surface layer 180 ° C., contact adhesive polymer layer 210
C., the base material layer was 210.degree. C., and the temperature of the die was 190.degree.
The temperature of the take-off rolls 3, 3 'was controlled to be 40 ° C. (At this time, the foam layer 5 is not laminated.)
The thickness of each layer of the obtained coating sheet is 100
μm, and the substrate layer was about 400 μm.

<Sheet B> Surface layer: thermoplastic urethane elastomer resin (manufactured by Asahi Glass Industry Co., Ltd., PN3429, JISA hardness 85 , glass)
Scan transition point: -10 ° C.) contacting adhesive polymer layer: acid modified SEBS (Asahi Chemical Industry Co., Ltd., TUFTEC M1943) substrate layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Industries Co., MILASTOMER 8030N) 80 parts of LLPE mixed with 20 parts of pellet blend A sheet for coating was prepared in the same manner as sheet A. (At this time, the foam layer 5 is not laminated.) The thickness of each layer of the obtained covering sheet is 100
μm, and the substrate layer was about 400 μm.

<Sheet C> Surface layer: thermoplastic urethane elastomer resin (manufactured by Asahi Glass Industry Co., Ltd., PN3429, JISA hardness 85 , glass)
Scan transition point: -10 ° C.) contacting adhesive polymer layer: acid modified SEBS (Asahi Chemical Industry Co., Ltd., TUFTEC M1943) substrate layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Industries Co., MILASTOMER 8030N) 80 parts of LLPE mixed with 20 parts of pellet blended A rubber roll having an embossed surface is used as the take-up roll 3 'on the sheet-like laminate 4 extruded from the co-extrusion apparatus, and the roll temperature is controlled to 50 ° C. Then, a coating sheet was prepared in the same manner as in the sheet A except that the surface layer was embossed. (At this time, the foam layer 5 was not laminated.) The thickness of each layer of the obtained covering sheet was about 100 μm for the surface layer and about 400 μm for the base material layer.

<Sheet D> Surface layer: thermoplastic urethane elastomer resin (manufactured by Asahi Glass Industry Co., Ltd., PN3429, JISA hardness 85 , glass)
Scan transition point: -10 ° C.) contacting adhesive polymer layer: acid modified SEBS (Asahi Chemical Industry Co., Ltd., TUFTEC M1943) substrate layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Industries Co., MILASTOMER 8030N) 80 parts of LLPE mixed with 20 parts of pellet blended Foam layer: Expanded polypropylene sheet (3 mm thick, manufactured by Sekisui Chemical Co., Ltd.) The above three layers are extruded under the same apparatus and conditions as sheet A, and extruded. Base layer 4c of the sheet-like laminate 4 in the melted state
On the side, the sheet-like foam layer 5 was laminated, and the sheets were passed through take-off rolls 3 and 3 ′ to be laminated.

The thickness of each layer of the obtained covering sheet 13 was about 100 μm for the surface layer, about 400 μm for the base material layer, and about 3 mm for the foam layer.

<Sheet E> Surface layer: thermoplastic urethane elastomer resin (manufactured by Asahi Glass Industry Co., Ltd., PN3429, JISA hardness 85 , glass)
Scan transition point: -10 ° C.) contacting adhesive polymer layer: acid modified SEBS (Asahi Chemical Industry Co., Ltd., TUFTEC M1943) substrate layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Industries Ltd.
8030N), 20 parts of LLPE
Part of pellet blended Foam layer: Foamed polypropylene sheet (3 mm thick, manufactured by Sekisui Chemical Co., Ltd.) In the same manner as for sheet D, foam layer 5 is applied to sheet-like laminate 4 extruded from a co-extrusion apparatus. Simultaneously with the lamination, embossing was performed on the surface layer 4a in the same manner as the sheet C.

The thickness of each layer of the obtained covering sheet 13 was about 100 μm for the surface layer, about 400 μm for the base material layer, and about 3 mm for the foam layer.

<Sheet F> Substrate layer: thermoplastic olefin elastomer resin (manufactured by Mitsui Petrochemical Co., Ltd., Mirastomer 8030N), 80 parts of LLPE and 20 parts of LLPE pellet-blended 40 extruder 1a manufactured by Plastic Engineering Laboratory And extruded. The resin temperature of the extruder 1a was 210 ° C. The equipment used was the same as in FIG. 1, but only one of the three extruders was used. In addition, each take-up roll 3,
The temperature of 3 ′ was controlled to be 40 ° C.

The thickness of the obtained sheet was about 500 μm.

<Sheet G> Substrate layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., Mirastomer 8030N), 80 parts of LLPE blended with 20 parts of pellets Take-out of sheet extruded from extruder Roll 3 '
As, using a rubber roll whose surface is embossed,
A sheet was prepared in the same manner as sheet F, except that the roll temperature was controlled to 50 ° C. and embossing was performed on the surface.

The thickness of the obtained sheet was about 500 μm.

<Sheet H> Base layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., Mirastomer 8030N), 80 parts of LLPE pellet blended Foam layer: foamed polypropylene sheet (Sekisui Chemical (Thickness: 3 mm, manufactured by Kogyo Co., Ltd.) Extruded under the same apparatus and conditions as the sheet F, and a sheet-like foamed material 5 whose surface was heated to 180 ° C. was laminated on the extruded sheet-like material in a molten state. In this state, the sheets were passed through take-off rolls 3 and 3 'and laminated.

The thickness of each layer of the obtained sheet is
The thickness was about 00 μm and the foam layer was about 3 mm. <Sheet I> Base layer: thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., Mirastomer 8030N), 80 parts of LLPE and 20 parts of pellet-blended foam layer: foamed polypropylene sheet (Sekisui Chemical Co., Ltd. ), Thickness 3 mm) In the same manner as the sheet H, the foam layer 5 was laminated on the sheet-like material extruded from the co-extrusion apparatus, and at the same time, the surface was embossed in the same manner as the sheet G.

The thickness of each layer of the obtained sheet was about 500 μm for the base material layer and about 3 mm for the foam layer. (Example 1) <Stamping molding (without preliminary molding)> Using the sheets A to E, stamping molding was performed by the stamping molding apparatus shown in FIGS. . This molding machine has an upper mold 20, a lower mold 21, and a resin injection machine 22, as shown in FIG. A convex portion 20a is provided on the lower surface of the upper die 20, the convex portion 20a is provided on an upper surface of the lower die 21, and a resin injection path 21b is formed in the center of the lower die 21. The nozzle 22a of the resin injection machine 22 is provided.

First, as shown in FIG. 3, the covering sheet 13 is introduced between the upper mold 20 and the lower mold 21 heated to a predetermined temperature, and the periphery of the sheet 13 is Was fixed with fixing pins 24. Next, as shown in FIG. 4, the formed resin 25 was injected into the lower mold 21 from the nozzle 22 a of the resin injection machine 22 at a nozzle tip temperature of 230 ° C. As the molding resin 25, polypropylene (Mitsubishi Yuka Co., Ltd., B
C3) was used.

Next, as shown in FIG. 5, the sheet 13 was shaped by closing the upper mold 20 at a predetermined pressure, and the molding resin 25 was stamped to obtain a molded product 27 having the shape shown in FIG.

5 and 6, L1 is 200 mm and L2 is 3 mm.
00 mm, L3 is 30 mm, L4 is 150 mm, L5 is 2
80 mm, L6 is 60 mm, and L7 is 500 mm.

The appearance and scratch resistance of the obtained molded article are evaluated. The scratch resistance is measured by a scratch test on a flat part of the molded product using a Taber clutch tester (Toyo Seiki Seisaku-sho, Ltd.), and the load of the appearance change (50 g) when the skin is visually scratched or torn. ~ 500
g) was represented by the following grade, and a load satisfying Grade 4 or higher was shown.

(Comparative Example 1) A molded product was obtained in the same manner as in Example 1 except that sheets F to I were used, and a similar test was performed.

Table 1 below shows the preheating temperature of the sheets of Example 1 and Comparative Example 1, and the evaluation of the appearance and scratch resistance of the obtained molded articles.

[0071]

[Table 1]

The stamping molded article using the coating sheet of the present invention showed good scratch resistance as compared with the sheet having no surface layer shown in Comparative Example.

(Example 2) <Injection molding (with preliminary molding)>
Injection molding was performed by the injection molding apparatus shown in FIGS. 7 to 10 according to the following method to obtain a molded product.

As shown in FIG. 7, this injection molding apparatus comprises a moving mold 10 having a concave portion 10a for molding and a vent 10b for drawing a vacuum, and a fixed mold 12 having a convex portion 12a.
And both dies 10 and 12, and both dies 1
It has a hot platen 14 having holes for vacuum and compressed air that can move outward from between 0 and 12, and a resin injection machine 15.

First, as shown in FIG. 8, a coating sheet 13 is disposed between the moving mold 10 and the hot platen 14, and the sheet 13 is heated while being sucked by the hot platen 14. The sheet 13 was subjected to vacuum and / or compressed air molding, and was brought into close contact with the inner surface of the concave portion 10a of the mold 10 as shown in FIG. Next, the hot platen 14 is moved outward from between the two molds 10 and 12,
Thereafter, as shown in FIG.
The mold was closed by moving to the side. Next, resin injection machine 1
From 5, the molding resin was injected into the cavity formed by both dies 10 and 12 at a nozzle tip temperature of 230 ° C. The molding resin used was polypropylene (BC manufactured by Mitsubishi Yuka Co., Ltd.)
5). After molding, the molded product was taken out of the mold to obtain an injection molded product.

In the same manner as in Example 1, the appearance and scratch resistance of the obtained molded product are evaluated.

(Comparative Example 2) A molded product was obtained in the same manner as in Example 2 except that sheets F to I were used, and a similar test was performed.

Table 2 below shows the preheating temperature of the sheets of Example 2 and Comparative Example 2, and the evaluation of the appearance and scratch resistance of the obtained molded products.

[0079]

[Table 2]

The injection-molded article using the covering sheet of the present invention showed good scratch resistance as compared with the sheet having no surface layer shown in Comparative Example. (Example 3) <Injection molding after pre-molding> Using sheets A to E, FIG.
Pneumatic molding was performed by a pneumatic molding apparatus as shown in FIGS. 1 to 13 according to the following method, and the molded product was obtained by sticking to an injection molded product.

As shown in FIG. 11, this pneumatic forming apparatus has a forming recess 32a and a vent 32b for drawing a vacuum.
And a hot platen 33 having holes for vacuum and compressed air that can move to the outside of the mold 32.

In the pneumatic forming, the covering sheet 13 is heated while being held between the hot plates 33 while being fixed to the sheet fixing frame as shown in FIG. It is transferred to the upper surface of the concave portion 32a of the female mold 32 for vacuum forming. Next, as shown in FIG. 13, the inner surface of the concave portion 32b of the female mold 32 is evacuated, and the covering sheet 13 is
Is preformed along the recess 32a. After molding, the air pressure was released, and the preformed molding sheet was taken out. Thereafter, the preformed molding sheet is introduced into the inner surface of the mold of the injection molding apparatus as shown in FIG.
Was moved to the fixed mold 12 side to close the mold. Next, the molding resin was injected from the resin injection machine 15 into the cavity formed by the two molds 10 and 12 at a nozzle tip temperature of 230 ° C. The molding resin used is polypropylene (BC5 manufactured by Mitsubishi Yuka Co., Ltd.). After molding, the molded product was taken out of the mold to obtain an injection molded product.

In the same manner as in Example 1, the appearance and scratch resistance of the obtained molded article are evaluated.

Comparative Example 3 A molded product was obtained in the same manner as in Example 3 except that sheets F to I were used, and a similar test was performed.

Table 3 below shows the sheet preheating temperature, the appearance of the molded product, and the evaluation of the scratch resistance of Example 3 and Comparative Example 3.

[0086]

[Table 3]

The injection-molded article using the coating sheet of the present invention exhibited good scratch resistance as compared with the sheet having no surface layer shown in Comparative Example.

[0088]

According to the present invention, by using a covering sheet having excellent scratch resistance and flexibility, it is possible to relatively easily form a molded article having excellent scratch resistance even if it has irregularities or curved surfaces. Obtainable.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an apparatus for producing a covering sheet used in the present invention.

FIG. 2 is an explanatory view of a stamping molding apparatus suitable for the present invention used in producing a molded article using a covering sheet.

FIG. 3 is a view for explaining a state in which a covering sheet is set on a lower mold of the stamping molding apparatus shown in FIG. 2;

4 is a view for explaining a state in which a molding resin serving as a molded article main body is injected into a lower mold of a stamping molding apparatus in which the covering sheet of FIG. 3 is set.

5 is a diagram illustrating a state in which the upper mold is closed to the lower mold into which the molding resin of FIG. 4 has been injected and stamping molding has been performed.

FIG. 6 is a sectional view of a stamping molded product taken out of a mold.

FIG. 7 is an explanatory diagram of an injection molding apparatus suitable for the present invention, which is used when a molded article is manufactured using a covering sheet.

FIG. 8 is a view for explaining a state before a coating sheet is preformed by the injection molding apparatus of FIG. 7;

9 is a partially cutaway front view illustrating a state in which a covering sheet is preformed by the injection molding apparatus of FIG. 7;

FIG. 10 is a diagram illustrating a state in which a molding resin to be a molded article main body is injection-molded.

FIG. 11 is an explanatory view of a pneumatic forming apparatus suitable for the present invention used in the case of manufacturing a molded product using a covering sheet.

FIG. 12 is a view for explaining a state before a covering sheet is preformed by the pneumatic forming apparatus of FIG. 11;

FIG. 13 is a view illustrating a state in which a covering sheet is preformed by the pneumatic forming apparatus of FIG. 11;

[Explanation of symbols]

1 Extruder 2 coextrusion device 3,3 'take-off roll 4 sheet stack 4a extruded surface layer 4b extruded sheet-like laminate sheet laminated body contact adhesive polymer layer 4c extruded sheet stack Base layer of body 5 Expanded polypropylene sheet (foam layer) 13 Sheet for covering 25 Molding resin 27 Molded product

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 43/18-43/20 B29C 43/32-43/34 B29C 51/06-51/14

Claims (2)

(57) [Claims] 1. A glass transition point (Tg) of -50 to 20.
° C., and a surface layer JIS A hardness is as a main component a thermoplastic urethane elastomer 50-98, contact adhesive polymer
And over layer, a substrate layer made of a thermoplastic elastomer as a main component, it is integrated product layer in this order this by coextrusion
That the covering sheet, to integrate the surface layer is a step of introducing into the mold so as to be positioned on the mold surface of the mold, and the molding resin is supplied to the gold in the mold and the covering sheet A method for producing a molded article, comprising the steps of: 2. A glass transition point (Tg) of -50 to 20.
° C., and a surface layer JIS A hardness is as a main component a thermoplastic urethane elastomer 50-98, contact adhesive polymer
And over layer, a substrate layer made of a thermoplastic elastomer as a main component, it is integrated product layer in this order this by coextrusion
That the cover sheet is introduced into the mold so that the surface layer is located on the mold surface of the mold and preformed pneumatically molding step be along the mold surface of the mold, and the mold in A method for producing a molded product, comprising a step of supplying a molding resin to the coating sheet and integrating it with the covering sheet.