JP3462119B2 - Multilayer molded product and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer molded article suitable for various exterior materials such as automobile interior materials such as seat covers and furniture interior materials. More specifically, the present invention relates to a multi-layer molded article that has excellent cushioning properties and practical strength, is easy to separate layers, and is recyclable.

[0002]

BACKGROUND OF THE INVENTION Multilayer laminates used for various kinds of surface covering materials include a single-layered surface skin or a surface skin composed of a urethane-based cushioning material, which is placed on the base material, or they are overlaid to surround each other. It is manufactured by melting and integrating. Also, automobile interior materials such as instrument panels, door trims, pillars, etc. are manufactured by mounting the skin on the concave surface of the mold and then injecting the resin as the base material,
Alternatively, it is also well known that liquid urethane is injected between the skin and the base material and foamed to manufacture.

In the above-mentioned molding method, in particular, in the method of molding by injecting the molten resin as the base material directly from the injection molding gate toward the back surface of the skin in the mold cavity, the injection pressure of the molten resin is applied to the skin. It has the drawback of being damaged by the effects of heat.

Therefore, for the purpose of preventing damage to the epidermis,
It has also been proposed to insert a protective sheet on the back surface of the skin corresponding to the injection position of the molten resin as the base material, but the work becomes extremely complicated and the obtained molded product is recycled and reused. It was difficult to do.

On the other hand, in recent years, environmental problems have become very important, and there has been a demand for resin recycling. Generally, a multilayer molded article is composed of different types of resins, or the same resin but with different physical properties, and it is necessary to separate each layer for resin recycling. . However, in the conventional multi-layer molded article, each layer is strongly integrally molded and their peel strength is usually equal to the material breaking strength, and it is practically impossible or extremely difficult to separate each layer from the resin. Was not suitable for recycling.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-layer molded article which is excellent in dimensional accuracy, excellent in cushioning property, and can be easily separated and recovered for each material constituting each layer while maintaining practical strength. To provide. It is another object of the present invention to provide a method for producing a multilayer molded article, which can efficiently mold the multilayer molded article without damaging the surface skin and suppress the defect rate to a low level.

[0007]

The multi-layer molded article according to the present invention comprises a single-layer or multi-layer skin material (A) made of a thermoplastic resin, a cloth (B) made of a thermoplastic resin fiber or a natural fiber, and a thermoplastic resin. A multilayer molded article composed of a base material (C) made of a resin, wherein the cloth (B) has a thickness of 1 to 100 mm and a basis weight of 50 to 1000 g / m ² to form the base material (C). Thermoplastic resin as base material (C)
To the opposite side of the fabric (B) that contacts with
Voids in the fabric (B) to the extent that the cushioning properties of the fabric (B) remain
The peel strength of the skin material (A) to the cloth (B) or the peel strength of the cloth (B) to the base material (C) is 0.1 to 15 kg, and each layer can be easily separated. Is characterized by.

In a preferred embodiment of the present invention, the cloth (B)
Is preferably a non-woven fabric made of a thermoplastic resin.
Further, in a preferred aspect of the present invention, it is desirable that both the skin material (A) and the base material (C) are made of a polyolefin resin.

In the method for producing a multilayer molded article according to the present invention, the skin material (A) is attached to one inner surface of an injection molding die, and an adhesive agent is applied on the skin material (A) if necessary. A method of molding, in which a sheet (B) is mounted, then the cloth (B) is mounted, the other mold is closed, and the base resin is injected, and the gas in the mold is injected by the molten resin forming the injected base material. While heating and passing through the voids of the fabric (B), the surface portion of the skin material (A) layer in contact with the fabric (B) is softened by the gas to fuse and integrate the surface portion and the fabric (B), Further, it is characterized in that the injected molten resin forming the base material is made to penetrate into the voids of the cloth (B) to such an extent that it does not penetrate to the opposite surface of the cloth (B) in contact with the base material (C).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The multilayer molded article of the present invention will be described in detail below. Skin material (A) The skin material (A) of the present invention is composed of a thermoplastic resin.
The thermoplastic resin is not particularly limited as long as it is conventionally used in the field, polyurethane,
Polyolefin, polyamide, polyester, polyvinyl chloride and the like, and polyurethane elastomer, polyolefin elastomer, polyester elastomer, acrylic acid elastomer, styrene elastomer, latex and the like are preferable. Among them, polyolefins or polyolefin-based elastomers are preferable, and as olefins, those made of ethylene or propylene or containing these are more preferable.

The skin material (A) may be a single layer or multiple layers of two or more layers. Each layer of the skin material (A) is a film, a sheet,
It may be in the form of cloth or foam, and may be coated with an adhesive or the like (when coated, the number of coating layers is counted as one layer). In here, as the adhesive, elastomers of the latex and the like are preferable. As the skin material (A), a non-woven fabric layer is laminated on a skin layer,
An example is a skin layer laminated with a foam layer.

It is desirable that these skin materials (A) are, as the outermost layer in the case of a single layer or a multi-layer, a skin which has been previously formed with irregularities by slush molding, powder slush molding, pressure molding or the like. . Further, when enhancing the cushioning property, a multi-layered skin material (A) in which foam layers are laminated is preferable.

The thickness of the skin material (A) is not particularly limited, and it is preferable that it is conventionally used in this field.

The layer of the skin material (A) in contact with the cloth (B) is
It is preferable to use a thermoplastic resin having a melting point or a softening point which is substantially the same as or lower than the melting point of the thermoplastic resin constituting the cloth (B). In this case, it is desirable to avoid a thermoplastic material having a melting point or a softening point higher by 30 ° C. or more than the melting point of the thermoplastic resin used as the base material (C).

Substrate (C) The substrate (C) of the present invention may be any one as long as it is a thermoplastic resin and can be selected according to the application. Of these, a polyolefin-based thermoplastic resin is preferable, and a resin made of ethylene and / or propylene or containing them is more preferable.

Cloth (B) The cloth (B) of the present invention maintains a certain level of strength even when the thermoplastic resin as the base material (C) is injected in a molten state, and the molten resin is It is preferable that the cloth (B) has a shielding property not to penetrate the cloth (B). Therefore, it is important that the cloth (B) used in the present invention has the specific physical properties described later.

Examples of the shape of the fabric (B) include non-woven fabric, woven fabric, knitted fabric, and synthetic paper. A non-woven fabric is mentioned as a preferable cloth (B). In particular, a nonwoven fabric made of continuous fibers is desirable in terms of bulkiness. The non-woven fabric is produced by a dry method or a wet method such as card, random weber and air raid, but is not particularly limited thereto.

The fibers used in the cloth (B) may be either thermoplastic resin fibers or natural fibers. As the thermoplastic resin, polyolefin and polyester are preferable, and among them, a resin made of ethylene and / or propylene or containing them is more preferable.

The fibers used for the cloth (B) are not limited to those produced from a single material, but bicomponent fibers, side-by-side fibers, etc., or several types thereof in order to improve the bulkiness, heat resistance and fusion bondability. It is also possible to mix and use fibers having different materials.

The area of the cloth (B) is preferably 80% or more of the area where the male and female dies are bonded, that is, the area where the base material (C) and the skin material (A) will contact. If it is too small, damage to the epidermis cannot be completely prevented,
Further, it becomes difficult to separate the skin material (A) and the base material ( C ) after molding.

The thickness of the cloth (B) is preferably 1 to 100 mm, more preferably 1.5 to 50 mm. The thickness is before preforming to match the irregularities of the skin material (A), and when preforming, it is preferably 0.5 mm or more after forming.

The fabric (B) is preferably 50 to 10
00 g / m ² , more preferably 100 to 600 g /
It is desirable that fibers having a basis weight of m ² and having a constituent fiber diameter of 0.5 denier (d) or more, preferably 1.2 denier (d) or more account for 30% or more by weight.

The fabric (B) needs a certain strength to prevent damage to the fabric itself during injection. Fabric (B)
The elongation at break is preferably 20% or more.

Method for Manufacturing Multilayer Molded Article The multilayer molded article of the present invention is preferably manufactured as follows. The skin material (A) and the cloth (B) are placed in a mold of an injection molding machine so that the cloth (B) covers almost the entire back surface of the inserted skin material (A). In this case, it is essential that the cloth (B) is present at least in the resin injection port.

After the mold is clamped, the resin as the base material is injected in a molten state from the cloth (B) side. The base material (C) is
Due to the heat and pressure at the time of injection of the molten resin, they enter the voids of the cloth (B), and the base material (C) and the cloth (B) are joined and integrated. At this time, the molten resin of the base material (C) does not penetrate the voids of the cloth (B) and at least the buffer of the cloth (B) is buffered.
The molding conditions are adjusted so that the properties remain . Further, the surface of the cloth (B) which is in contact with the base material (C) may be softened or melted.

At the same time as joining the base material (C) and the cloth (B),
The gas in the mold heated by the molten resin of the base material (C) enters into the voids of the cloth (B) and reaches the surface of the skin material (A) which is in contact with the cloth (B), It is heated and melted, whereby the skin material (A) is joined to the cloth (B).

As a result, the skin material (A), the base material (C) and the cloth (B) interposed therebetween are joined and integrated in the mold of the injection molding machine. In addition, when the unevenness of the skin material (A) formed in advance is complicated,
It is desirable that the cloth (B) to be interposed be preformed by press molding or the like to have similar unevenness. As a result, the injection molding can be easily set in the mold, the flow of the molten resin into the mold is ensured, and the conformability of the shape is improved. By adopting the manufacturing method as described above, the defective rate due to damage to the skin is reduced, and efficient molding is possible.

Multi-layer molded article The multi-layer molded article of the present invention is also superior in cushioning properties to conventional products. That is, in the conventional product, the skin material was bonded to the base material directly or via the foamed material, but in the multilayer molded article of the present invention, the thermoplastic resin of the base material (C) was interposed via the cloth (B). By this, the cushioning property of the fabric is further added to the conventional cushioning property.

In addition, the multilayer injection-molded article of the present invention facilitates the separation and recovery of the skin material (A) and the base material (C) for recycling synthetic resin, especially thermoplastic resin, which has been widely sought in recent years. . That is, in the present invention, it is possible to set a uniform peel strength on almost the entire surface of the molded article by the cloth (B), and further it is possible to adjust the peel strength itself. Therefore, the skin material (A) and the base material (C) can be easily separated and separated without impairing the practical strength.

In the multilayer molded article of the present invention, the peel strength of the skin material (A) from the cloth (B), or the cloth (B)
The peel strength of the base material (C) to the base material (C) is such that it does not peel under normal use and can be easily peeled off by applying a force more than normal, specifically, 0.1 to 1
It is preferably 5 kg, especially 0.5 to 15 kg. The peel strength can be adjusted by adjusting the thickness of the cloth (B), the fiber density,
It can be adjusted by the constituent fiber diameter.

The multilayer molded article of the present invention can be used for all purposes. For example, automotive interior materials such as instrumental panels, door trims, pillars, etc., chairs, furniture covering materials such as chests of drawers, motorcycle seats for motorcycles, bicycles, etc., and cushioning packaging materials used in gift boxes, etc. , Attaché cases, suitcases and other bag cover materials.

[0032]

EXAMPLES The present invention will be described below with reference to examples. The present invention is not limited to the embodiments described below, and is not different from the present invention as long as the operating mechanism and the like are the same.

(Example 1) [Molded product 1] Skin material (A): ethylene / propylene copolymer elastomer single layer, cloth (B): polypropylene spunbonded nonwoven fabric (fineness: 8 denier, basis weight: 400 g / m 2). ² , thickness: 4m
m), base material (C): polypropylene, molding method: skin material (A), cloth (B) on one mold inner surface
Are mounted in this order, the other mold is closed, and then the resin temperature 21
The resin of the base material (C) was injection-molded at 0 ° C. and a holding time of 10 seconds to obtain a molded product.

(Example 2) [Molded product 2] Skin material (A): Skin first layer made of ethylene / propylene copolymer elastomer, Skin second layer made of polyethylene resin foam, Fabric (B): Spunbond polypropylene non-woven fabric (fineness: 8 denier, basis weight: 400 g / m ² , thickness: 4 m
m), base material (C): polypropylene, molding method: skin material (A), cloth (B) on one mold inner surface
Are mounted in this order, the other mold is closed, and then the resin temperature 21
The resin of the base material (C) was injection-molded under the conditions of 0 ° C. and a holding time of 10 seconds to obtain a molded product.

(Example 3) [Molded product 3] Skin material (A): single layer made of ethylene / propylene copolymer elastomer, cloth (B): spunbonded nonwoven fabric of polyethylene terephthalate (fineness: 3 denier, basis weight: 400 g / m ² ,
Thickness: 4 mm), Base material (C): Polypropylene, Molding method: Skin material (A), cloth (B) on one mold inner surface
Are mounted in this order, the other mold is closed, and then the resin temperature 21
The resin of the base material (C) was injection-molded at 0 ° C. and a holding time of 10 seconds to obtain a molded product.

(Example 4) [Molded product 4] A polypropylene spunbonded non-woven fabric (B) was prepared by
Fineness: 4 denier, basis weight: 200 g / m ² , thickness: 2 m
A molded product was obtained in the same manner as in Example 1 except that the product was changed to m.

(Example 5) [Molded product 5] A polypropylene spunbonded nonwoven fabric of the fabric (B) was
Fineness: 16 denier, basis weight: 600 g / m ² , thickness: 1
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to 0 mm.

(Example 6) [Molded product 6] A polypropylene spun-bonded non-woven fabric (B) was prepared as follows.
Fineness: 2 denier, basis weight: 80 g / m ² , thickness: 1.2
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to that of mm.

(Example 7) [Molded article 7] A polypropylene spunbonded non-woven fabric of the cloth (B) was prepared as follows.
Fineness: 8 denier, basis weight: 800 g / m ² , thickness: 40
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to that of mm.

(Example 8) [Molded article 8] A polypropylene spunbonded nonwoven fabric of the fabric (B) was prepared by
A molded product was obtained in the same manner as in Example 1 except that the polypropylene short fiber nonwoven fabric (fineness: 3 denier, basis weight: 300 g / m ² , thickness: 4 mm) was used.

(Comparative Example 1) [Molded product 9] A polypropylene spunbonded non-woven fabric of the fabric (B) was
Fineness: 2 denier, basis weight: 40 g / m ² , thickness: 0.3
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to that of mm.

(Comparative Example 2) [Molded product 10] A polypropylene spunbonded non-woven fabric (B) was prepared as follows.
Fineness: 3 denier, basis weight: 40 g / m ² , thickness: 0.6
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to that of mm.

(Comparative Example 3) [Molded product 11] A polypropylene spunbonded non-woven fabric (B) was used.
Fineness: 16 denier, basis weight: 800 g / m ² , thickness: 1
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to 20 mm.

(Comparative Example 4) [Molded product 12] A polypropylene spunbonded nonwoven fabric of the fabric (B) was
Fineness: 8 denier, basis weight: 1200 g / m ² , thickness: 4
A molded product was obtained in the same manner as in Example 1 except that the thickness was changed to 0 mm.

(Comparative Example 5) [Molded product 13] A molded product was obtained in the same manner as in Example 1 except that the fabric (B) was not attached.

The 13 molded articles were compared for peel strength, damage to the skin, and cushioning. Damage to the cover is visually
The buffering property was compared by a sensory test of 10 populations. The peeling strength is 5 cm in width from the skin material side to each part of the molded product, a cut is made through the skin material / fabric, and the skin portion is turned up.
The strength at which peeling progressed was measured. The results are shown in Table 1.

[0047]

[Table 1] Description in Table 1 Good: Good, Bad: Bad, "-" in the peel strength column cannot be measured due to skin damage.

[0048]

EFFECT OF THE INVENTION The multilayer injection-molded article of the present invention is excellent in dimensional accuracy and cushioning property without damaging the skin by fusing a specific fabric between the skin material and the base material, and It is a molded product in which the skin and the base material can be easily separated while maintaining practical strength, and is extremely useful for automotive interior parts, furniture outer coverings, motorcycle seats, packaging materials, bag outer coverings and the like.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI B29L 31:58 B29L 31:58 (72) Inventor Akira Yamazaki 2-8-45 Yoshinodai, Kawagoe City, Saitama Prefecture (56) Reference JP-A-9 -1586 (JP, A) JP-A-6-255043 (JP, A) JP-A-9-99523 (JP, A) JP-A-11-46876 (JP, A) JP-A-9-76384 (JP, A) ) JP-A-7-269080 (JP, A) JP-A-7-329234 (JP, A) JP-A-8-290511 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 45/00-45/84

Claims (4)

(57) [Claims] 1. A single-layer or multi-layer skin material (A) made of a thermoplastic resin, a cloth (B) made of a thermoplastic resin fiber or a natural fiber, and a base material (C) made of a thermoplastic resin. In the molded product, the thickness of the cloth (B) is 1
To 100 mm, basis weight 50 to 1000 g / m ²
And the thermoplastic resin forming the substrate (C) is a substrate
To the extent that it does not penetrate to the opposite surface of the fabric (B) that is in contact with (C)
And to the extent that the cushioning properties of the fabric (B) remain
The peeling strength of the skin material (A) with respect to the cloth (B) or the peel strength of the cloth (B) with respect to the base material (C) is 0.1 to 15 kg, and the layers can be easily separated. A multi-layer molded product characterized by being present. 2. The multilayer molded article according to claim 1, wherein the cloth (B) is a non-woven fabric made of a thermoplastic resin. 3. The multilayer molded article according to claim 1, wherein both the skin material (A) and the base material (C) are made of a polyolefin resin. 4. The surface material (A) is mounted on one inner surface of an injection molding die, an adhesive sheet is mounted on the surface material (A) as required, and then the cloth (B) is attached. A molding method of mounting, closing the other mold and injecting the base resin,
The molten resin forming the injected base material heats the gas in the mold and allows it to pass through the voids of the cloth (B) to soften the surface portion of the skin material (A) layer in contact with the cloth (B) with the gas. Then, the surface portion and the cloth (B) are fused and integrated with each other, and the molten resin forming the injected base material is not penetrated to the opposite surface of the cloth (B) in contact with the base material (C). The method for producing a multilayer molded article according to any one of claims 1 to 3, characterized in that it is perforated in the voids of the cloth (B).