JP2611775B2 - Molded body with skin and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic resin molded article having a skin layer having an excellent appearance used for automobile interior materials and electric appliances, and a method for producing the same.

<Prior Art> Conventionally, a molded product obtained by laminating a skin material on a polyolefin-based thermoplastic resin base material to enhance its aesthetic appearance, softness, and the like and upgrade the quality thereof has been widely used.

As a method for producing these molded articles with a skin, a polyolefin-based thermoplastic resin is molded by vacuum molding or the like on a molded article previously molded by various molding methods such as injection molding, or There is a method of performing adhesive lamination using an adhesive while performing simultaneous shaping. Further, as another method, a skin material is placed between a pair of male and female molds for molding, and a thermoplastic resin which is heated and melted after closing the mold is injected into the mold from a mold gate. There is also known a method in which the molded product is taken out by laminating with the skin material, opening the mold after cooling.

<Problems to be Solved by the Invention> However, it is known that the above method has the following disadvantages.

In the former method, an adhesive is used, so that the process becomes complicated and expensive, and there is a possibility that the solvent or dispersant used in the adhesive may cause environmental pollution. In the latter,
The molten resin is injected into the mold, and the high-temperature and high-pressure molten resin comes into contact with the skin material and strongly presses the skin material against the mold surface, so that the surface of the skin material may be discolored or the pattern may be deformed. ,
In a woven fabric having a raised surface, the appearance is impaired due to hair falling or hair flow. Further, in some cases, the skin layer may be impregnated with the molten resin and lose commercial value.
For the purpose of preventing the above-mentioned drawbacks or a drawback in which the flexibility of the skin is impaired, a plastic foam is interposed between the skin and the thermoplastic resin, or a backing material such as paper or dense plastic foam is insulated. It has been proposed to use it as a material or a resin barrier material.
However, when a plastic foam alone is interposed, the foam is broken by the heat and pressure of the molten resin. Severe irregularities occur on the surface, which are transferred to the surface of the skin layer, which impairs the appearance and deteriorates the touch. In addition, when a molded product has a complicated shape with a backing material that has rigidity such as paper or dense plastic foam and has relatively small elongation, it may be partially torn or warped during molding. Impair the appearance.

It has also been proposed to use a skin material having a protective layer made of the same kind of plastic as a thermoplastic resin (JP-A-54-71161).

However, when such a backing material or a protective layer is used, the appearance of the skin can be maintained, but there is a problem that the molded product is warped and the commercial value is easily lost.

Furthermore, a method of using an ethylene-vinyl acetate copolymer as an adhesive layer is also known (JP-A-56-109759;
However, in this method, the adhesive layer has a very low softening temperature of 25 to 50 ° C., and when the ambient temperature reaches several tens of degrees C., the adhesive strength is significantly reduced. Is likely to separate from the base resin or cause misalignment.
There is a practical problem in terms of heat resistance as an interior material for an automobile having a temperature of over ℃.

An object of the present invention is to provide a high quality thermoplastic resin molded article with a skin and a method for producing the same, which do not have such a drawback.

<Means for Solving the Problems> That is, the present invention provides: (1) a. A polyolefin-based thermoplastic resin; b. A thermoplastic resin having compatibility with a Young's modulus of 3,000 k.
The present invention provides a resin intermediate layer made of a polyolefin-based thermoplastic elastomer of not more than g / cm ² , and a molded article with a skin made of c. a skin, and (2) a polyolefin-based thermoplastic resin made of gold. In a method of molding in a mold, a mold lined with a skin lined with a resin intermediate layer that is compatible with the thermoplastic resin and has a Young's modulus of 3,000 kg / cm ² or less made of a polyolefin-based thermoplastic elastomer. With a skin that is placed between the molds and supplies the heated and melted thermoplastic resin between the back of the skin and one of the molds with the mold not closed, and then combines and molds both molds It is intended to provide a method for producing a molded article.

 Hereinafter, the present invention will be specifically described.

In the present invention, the polyolefin-based thermoplastic resin used as the substrate can be any of polyolefin-based thermoplastic resins commonly used in compression molding, injection molding, extrusion molding, and the like. Examples include various polyethylenes such as high-density polyethylene, polypropylene, various copolymers containing propylene as a main component, various polyolefin-based polymer alloys, and mixtures thereof.

Various additives such as inorganic fillers, glass fibers and other fillers, pigments, lubricants, antistatic agents and stabilizers can be added to such a polyolefin-based thermoplastic resin as required.

The skin used in the present invention is appropriately selected depending on the intended product, and is not particularly limited, but has a decorative property when it is intended for a molded article of an automobile interior material or an electric product material, and has a soft feeling. Some are preferably used.

Examples of the skin having such properties include non-breathable skin materials such as sheets and films of various resins (hereinafter, sheets and films are collectively referred to as sheets), and permeable fabrics and nonwoven fabrics as breathable skin materials. No.

A typical example of the resin sheet is a vinyl chloride resin sheet. Such a vinyl chloride resin sheet may be a vinyl chloride polymer, a vinyl chloride copolymer containing vinyl chloride as a main component, or a mixture of these as required. Other thermoplastic resins, stabilizers, various additives such as plasticizers, the vinyl chloride resin composition obtained by appropriately compounding the compounding agent, calendering method,
It is manufactured by forming a sheet by a continuous extrusion method or the like.

The thickness of the sheet is preferably 0.01 to 2 mm, particularly preferably 0.01 to 1 mm.

The fibers constituting the woven fabric, which is a breathable skin material, may be natural fibers such as cotton, hemp and silk, as well as synthetic fibers such as polyamide and polyester.These fibers may be used alone or in combination. The woven fabric can be woven by various methods, and examples of such woven fabric include woven or knitted fabrics such as plain weave, moquette, and tricot.

Further, the non-woven fabric can be used whether it is made of natural fibers or synthetic fibers, and the production method is not limited.

The resin intermediate layer in the present invention is a polyolefin-based thermoplastic elastomer, having a Young's modulus of 3,000 kg / cm ² or less, and one that is compatible with the thermoplastic resin used, and is usually a sheet or Used as a film.

Such a resin intermediate layer is usually used by backing a resin sheet made of the above-mentioned polyolefin-based thermoplastic elastomer to a skin material.

As a backing method, for example, such a resin sheet may be manufactured by a T-die sheet manufacturing apparatus, and this may be bonded to the back surface of the skin using an adhesive. It may be laminated to a material.

The thickness of the sheet is not particularly limited. However, if the sheet is too thin, it will be easily broken by the heat and supply pressure of the molten resin when the molten polyolefin-based thermoplastic resin is successfully supplied, or the heat insulating effect will not be achieved until the sheet is not broken. If it is sufficient, the appearance of the skin is easily damaged, and if it is too thick, the heating of the sheet by the molten resin becomes insufficient, so that the adhesiveness between the sheet and the polyolefin-based thermoplastic resin as the base material tends to decrease. Therefore, it is preferably about 0.1 to 1 mm.

In the present invention, the skin can be used as it is, but it can also be used as a skin backed by a foam layer.

As such a foam layer, various materials can be used according to the respective applications and purposes, and typical examples are thermosetting resin materials such as soft or semi-rigid polyurethane, vinyl chloride resins, Examples include foams manufactured from thermoplastic resin materials such as polyethylene and polypropylene, and rubber materials such as ethylene-propylene copolymer rubber and natural rubber.

When such a foam layer is lined with a skin material, the appearance and tactile sensation of the skin are further improved by the heat insulating (shielding) effect and the cushioning effect as compared with the case where it is not present.
The effect of using the resin intermediate layer is further exhibited.

When the foam layer is lined with a gas-permeable skin such as a woven fabric or a non-woven fabric, it is preferable to laminate the foam layer via a non-gas-permeable thermoplastic resin layer.

Such non-breathable thermoplastic resin layer, polypropylene, polyethylene, propylene-based copolymer, ethylene-based copolymer, ethylene-vinyl acetate copolymer, TPE,
A sheet or film made of polyamide, polyester, vinyl chloride copolymer or the like is used, and its thickness is usually 0.01 to 1 mm, preferably 0.01 to 0.5 mm.

This thermoplastic resin layer is used to block the air contained in the skin from the foam layer, and it is necessary that the layer be non-breathable. If a breathable film is used, it is built into the skin. The generated air causes severe unevenness on the skin side of the foam layer, which affects the skin and causes unevenness on the skin itself, which impairs the appearance.

Next, a method for producing a molded article with a skin of the present invention will be described.

As a molding method, a known method such as an injection molding method or a compression molding method can be applied, but a compression molding method is more preferable from the viewpoint of the appearance of the skin material and keeping the texture.

In the case of such a compression molding method, for example, it is compatible with a polyolefin-based thermoplastic resin as a base material, and is backed with a resin sheet made of a polyolefin-based thermoplastic elastomer having a Young's modulus of 3,000 kg / cm ² or less. Place the skin material between the molding dies, and with the dies unclosed,
The heated and melted polyolefin-based thermoplastic resin is supplied between the back surface of the skin material and one of the molds, and then the two molds are joined (clamped) to be molded.

In this case, as the skin, as described above, a foam-backed material can be used with or without a gas-impermeable thermoplastic resin layer.

<Examples> Hereinafter, the present invention will be described with reference to examples, but these are illustrative, and the present invention is not limited to these examples.

Example 1 A molded article with a skin (a box with a flange shown in a sectional view in FIG. 2) was manufactured using the compression molding apparatus shown in FIG.

First, a 0.5 mm thick thermoplastic elastomer sheet (Sumitomo Chemical Co., Ltd., Sumitomo Chemical Co., Ltd.)
TPE # 1800 was obtained by forming a sheet using a T-die sheet manufacturing apparatus. Skin material 1 bonded with Young's modulus 900 kg / cm ² )
Was placed on the mating surface 2 of the female mold 5 located below with the surface (ticket side) facing downward. (FIG. 1a).

Next, the skin material was fixed to the female mold mating surface 2 by a spring pressure using a skin material fixing plate 13 attached to the male mold 3.

A predetermined amount of molten propylene-ethylene block copolymer (Sumitomo Noblen AZ864, manufactured by Sumitomo Chemical Co., Ltd., melt index 30 g / 10) by a screw in-line type injection device 6
) Was supplied from the resin supply gate 4 in the male mold onto the back surface (the thermoplastic elastomer sheet side) of the skin material. The temperature of the molten resin at this time was about 230 ° C. (Fig. 1b) When the molten resin was supplied, the female mold 5 was raised and both molds were closed. (FIG. 1c) The surface pressure (average resin pressure acting in the cavity) at this time was 100 kg / cm ² .

FIG. 2 shows a cross-sectional view of the obtained propylene molded article with a skin (moquette layer). Although the propylene molded article has a relatively complicated shape, it does not warp, and the skin has no wrinkles or tears. There was no appearance, and the moquette's hair fell, and the polypropylene had an excellent appearance without seepage.

Comparative Example 1 A molded article with a skin was obtained in the same manner as in Example 1, except that the thermoplastic elastomer sheet was not used.

In the obtained molded article, hair flow on the surface of the moquette as the skin occurred, and the color of the skin was yellowish. Further, the polypropylene partially exuded on the surface of the epidermis, resulting in poor appearance.

Comparative Example 2 Example 1 except that a 0.5 mm polypropylene sheet (manufactured by Sumitomo Chemical Co., Ltd., manufactured by Sumitomo Noblen AS171A and sheeted with a T-die sheet manufacturing apparatus; Young's modulus 6,000 kg / cm ² ) was used instead of the thermoplastic elastomer. In the same manner as in the above, a molded body with a skin was obtained.

The obtained molded article had a good surface appearance, but exhibited large warpage and was of no commercial value.

Example 2 Instead of the moquette 25 as a skin layer, a polypropylene nonwoven fabric (manufactured by Hayashi Tenlep, plain knee pan, unit weight 30)
A molded article with a skin was obtained in the same manner as in Example 1 except that 0 g / m ² ) was used.

The obtained molded body had no warpage and had an excellent appearance.

Comparative Example 3 A molded article with a skin was obtained in the same manner as in Example 1 except that only a polypropylene nonwoven fabric (plain knee pan) to which a thermoplastic elastomer was not bonded was used. Polypropylene oozed out into the skin layer of the obtained molded product, and the appearance was poor.

[Brief description of the drawings]

1a to 1c are cross-sectional views showing an outline of manufacturing a molded article with a skin. FIG. 2 is a sectional view of the molded product obtained in Example 1. FIG. 3 is a sectional view of the molded article obtained in Example 3. 1: skin material, 2: female mold mating surface 3: male mold, 4: resin supply gate 5: female mold, 6: inline injection machine 7: molded body with skin, 8: skin 9: resin intermediate layer , 10: thermoplastic resin 11: non-breathable thermoplastic resin layer, 12: foam layer 13: skin material fixing plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location // B29K 21:00 B29L 9:00 (72) Inventor Tadayuki Oda 355-1 Nakagawara 1 Kizumi Chemical Industry Co., Ltd. (72) Inventor Atsura Shirakawa 3-3 Kitahama, Higashi-ku, Osaka City, Osaka Prefecture Nissen Chemical Industry Co., Ltd. 3-Chome-3 Nissen Chemical Co., Ltd. (72) Inventor Yuji Kamiji 3-3-1 Kitahama, Higashi-ku, Osaka-shi, Osaka Nissen Chemical Co., Ltd. (56) References JP-A-54-71161 (JP, A) JP-A-56-109759 (JP, A) JP-A-56-109760 (JP, A) JP-A-55-82627 (JP, A) JP-A-60-212343 (JP, A) JP-A Sho 57 −29436 (JP, A)

Claims (8)

(57) [Claims] 1. Polyolefin thermoplastic resin b. Compatible with thermoplastic resin and Young's modulus is 3,000k
A molded article with a skin, comprising: a resin intermediate layer made of a polyolefin-based thermoplastic elastomer of g / cm ² or less; and c. 2. The molded article with a skin according to claim 1, wherein the skin is a non-breathable skin. 3. The molded article with a skin according to claim 2, wherein the skin is lined with a foam layer. 4. The molded article with a skin according to claim 1, wherein the skin is a vinyl chloride resin sheet. 5. The molded article with a skin according to claim 1, wherein the skin is a breathable skin. 6. The air-permeable skin is lined with a foam layer via a non-air-permeable thermoplastic resin layer.
A molded article with a skin according to item. 7. The molded article with a skin according to claim 5, wherein the air-permeable skin is a woven or non-woven fabric. 8. A method for molding a polyolefin-based thermoplastic resin between molds, comprising: a resin comprising a polyolefin-based thermoplastic elastomer having a Young's modulus of 3,000 kg / cm ² or less, which is compatible with the thermoplastic resin. The skin lined with the intermediate layer is placed between the molding dies, and the heated molten thermoplastic resin is supplied between the back surface of the skin and one of the dies while the dies are not closed. A method for producing a molded article with a skin, comprising combining a mold and molding.