JPS63144047A - Laminated sheet for molding - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a molding laminate sheet used as a material for molding soft resin molded products.

(Prior Art) As a general structure of a soft resin molded product, there is one in which a soft resin sheet made of a soft resin is provided on the surface of a resin base material made of a hard resin.

Conventionally, the most widely used flexible resin sheet is a laminated sheet in which a thin protective layer made of polyvinyl chloride resin or the like is bonded to the surface of a spongy soft layer made of foamed polyolefin resin or the like. .

The following method is used to mold the resin molded product using this laminated sheet.

■ A method in which a laminated sheet is set in an injection mold in advance, a hard resin is injection molded on the back side of the laminated sheet, and the resin base material is molded and the laminated sheet is bonded to the resin base material at the same time.

■Similarly, a laminated sheet is set in a blow molding mold, and a hard resin is blow-molded on the back side of the laminated sheet.

■Stamping molding method.

(Problems to be Solved by the Invention) However, in the laminated sheet, the adhesiveness between the spongy soft layer and the protective layer is not good, and when the thickness of the spongy soft layer is less than 4III11, the predetermined soft texture There were problems such as not being able to obtain

Further, when molding a soft resin molded article using the laminated sheet by each of the molding methods (1) to (4) described above, there were the following problems.

That is, in each of the above-mentioned molding processes, the laminated sheet is heated to near or above its softening temperature by the molten hard resin for the resin base material and the mold, and is also subjected to high molding pressure.

Therefore, the air bubbles (hereinafter referred to as voids) in the spongy soft layer of the laminated sheet are crushed by the molding pressure,
After molding, the soft resin molded product no longer exhibits a sufficiently soft texture.

Structure of the Invention (Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the present invention constitutes a laminated sheet for molding in which a styrene thermoplastic elastomer layer and a polyolefin resin layer are laminated. It is something.

(Function) The laminated sheet for molding of the present invention is used as a material for molding soft resin molded products.
A mode in which the polyolefin resin layer is on the surface side of the molded product,
(2) There is an embodiment in which the styrene thermoplastic elastomer layer is on the surface side of the molded product.

Here, the styrene-based thermoplastic elastomer is a polymeric material that has excellent bondability to polyolefin resin.

Therefore, the styrene-based thermoplastic elastomer layer and the polyolefin resin layer are laminated with strong bonding force without activation treatment or primer treatment, and the bond between them is strong during molding or use of a soft resin molded product. There is no possibility of peeling.

In addition, the styrenic thermoplastic elastomer layer has flexibility due to the soft segment contained therein, so
It functions as a soft layer inside or on the surface that gives a soft feel even if it is thin (even for about 0.5 seconds).

In general, the styrene-based thermoplastic elastomer layer does not obtain its softness from voids like conventional sponge-like soft layers, so it does not collapse during molding of the molded product.

On the other hand, the polyolefin resin layer should be designed to have a hardness and thickness that does not impair the flexibility of the styrene-based thermoplastic elastomer layer in the case where the polyolefin resin layer is on the surface side of the molded product. , functions as a protective layer for the styrene-based thermoplastic elastomer layer, and (1) in the usage mode where the polyolefin resin layer is inside the styrene-based thermoplastic elastomer layer, it can be used as the resin base material itself of the molded product or with another resin base material. Functions as an intervening layer with the styrene thermoplastic elastomer layer.

(First Example) Hereinafter, a first example in which the present invention is embodied in a molding laminate sheet used in an embodiment in which the polyolefin resin layer is on the surface side of a soft resin molded product will be described with reference to FIGS. 1 to 3. do.

As shown in FIG. 1, the laminated sheet 1 for molding of this embodiment is made of styrene thermoplastic elastomer and has a thickness of approximately 4 mm.
A polyolefin resin layer 3 made of polyolefin resin and having a thickness of about 0.4 am is laminated on the surface of an ethylene-based thermoplastic elastomer layer 2 of the shoe.

This lamination method includes (1) an extrusion molding method in which both layers 2 and 3 are laminated immediately after extruding them from an extrusion molding machine, and (2) a styrene thermoplastic elastomer layer 2 extruded from an extrusion molding machine.
In addition, there is a method of laminating pre-formed polyolefin resin layer 3 with a laminator, and
Insert injection molding, etc., in which the styrene-based thermoplastic elastomer layer 2 is injection molded into an injection mold set therein, is selectively employed as appropriate.

The styrene thermoplastic elastomer is a polymeric material that has excellent bondability to polyolefin resins. Therefore, the styrene-based thermoplastic elastomer layer 2 and the polyolefin resin layer 3 are laminated with strong bonding force without activation treatment or brimer treatment, and between them,
There is no possibility of peeling during molding or use of soft resin molded products, which will be described later.

Also, the hardness of the styrene thermoplastic elastomer layer 2 is)
(S (JIS A) is preferably 30 to 50. If it is less than 30, it is too soft and does not have the specified elasticity;
This is because if it exceeds the desired soft texture, it will not be possible to obtain the desired soft texture.

Further, the thickness of the styrenic thermoplastic elastomer layer 2 should be at least 0.5 Mn, since it will provide a soft texture, and the upper limit may be as long as it is moldable, so it depends on the case.

Furthermore, since the polyolefin resin layer 3 functions as a protective layer for the styrene-based thermoplastic elastomer layer 2, its hardness and thickness should be set to a level that does not impair the soft feel of the styrene-based thermoplastic elastomer layer 2; Any material designed to allow the softness of the styrene thermoplastic elastomer layer 2 to be felt through the resin layer 3 may be used.

Next, details of each of the above materials will be explained.

The styrenic thermoplastic elastomer may be (1) a block polymer in which polybutadiene, polyisoprene or olefin copolymer is used as a soft segment and polystyrene is used as a hard segment, or (2) the soft segment is hydrogenated to form a double bond. A saturated block polymer is used.

Here, since the block polymer (2) does not have double bonds between molecules, it has better weather resistance than the block polymer (2).

As the olefin in the above olefin copolymer,
Examples include ethylene, propylene, butene, butadiene, and isoprene. Preferred olefin copolymers are those of ethylene and butadiene or butene.

The copolymerization ratio of the soft segment to the entire styrenic thermoplastic elastomer (hereinafter simply referred to as copolymerization ratio).

) is determined in consideration of softness, and when attempting to obtain a styrene-based thermoplastic elastomer layer 2 with low hardness and high flexibility, the copolymerization ratio is increased.

In the present invention, the preferred range of copolymerization ratio is 60 to 95.
(weight ratio), and particularly when polyisoprene is used as the soft segment, it is desirable that it be 80 or more. This is to keep the hardness of the styrene thermoplastic elastomer layer 2 within the above range.

The styrenic thermoplastic elastomer can be used alone, but it can also be used as a mixture with an olefin resin, oil, antioxidant, inert filler, flame retardant, etc.

This compound has the following properties:
4400'' (a product and trademark name of Mitsubishi Yuka Co., Ltd.) can be exemplified.

Hardness H8 (JIS^)...45
Specific gravity (JIS 7112), 1
, 1MFR (JIS 7210*) ...0
．． 4g/10 minutes 300% stress (JIS 6301 **
)...12 Kg/cm Here, the * mark is 230
The test was carried out under the conditions of ℃ x 2.26 kg, and the ** mark means that the test was carried out under the conditions of a tensile speed of 500 m/min using JISa dumbbells.

Next, examples of the polyolefin resin used for the polyolefin resin layer 3 include polyethylene, polypropylene, and the like.

Here, the styrenic thermoplastic elastomer layer 2 is coated with the "
A 180 degree peel test was conducted on a laminate sheet 1 for molding using Lavalon 5J4400'', polypropylene for the polyolefin resin layer 3, and both layers 2 and 3 laminated by injection molding from the insert 1. Saha 1
It was as high as 5 to 9/cm.

Now, a method for producing a soft resin molded product by insert injection molding using the molding laminate sheet 1 constructed as described above will be explained with reference to FIG.

First, the laminate sheet 1 for molding is heated to soften it, and the polyolefin resin layer 3 is set against the mold surface of the movable mold 4 of an injection mold.

Next, the movable mold 4 is matched with the fixed mold 5, and polypropylene resin for the resin base material is injected from the injection nozzle 6 provided on the fixed mold 5.

Then, the same polypropylene resin fills the cavities of both molds 4 and 5 to form a resin base material 7 as shown in FIG. do.

At this time, the styrene-based thermoplastic elastomer layer 2 is subjected to heat and pressure, but the styrene-based thermoplastic elastomer layer 2 obtains its softness from the rough 1 to segments, and does not behave like a conventional spongy soft layer. Since it is not obtained by voids, it will not be crushed during injection molding.

After the resin base material 7 is cooled and solidified, both molds 4 and 5 are opened.
The soft resin molded product 8 shown in FIG. 3 can be taken out.

In the soft resin molded product 8 thus obtained, the styrene thermoplastic elastomer layer 2 functions as a soft layer that provides a soft feel.

On the other hand, the polyolefin resin layer 3 functions as a protective layer that protects the styrene-based thermoplastic elastomer layer 2 without impairing its flexibility.

(Second Example) Next, a second example in which the present invention is embodied in a molding laminated sheet used in an embodiment in which the styrenic thermoplastic elastomer layer is on the surface side of a soft resin molded product will be described in the fourth to fourth examples. This will be explained according to Figure 5.

As shown in FIG. 4, the laminated sheet 11 for molding of this example has an ethylene-based thermoplastic elastomer layer 1 with a thickness of about two sides.
A polyolefin resin layer 13 having a thickness of approximately 2 mm is laminated on the surface of 2.

The materials, conditions, and lamination method for each layer 12, 13 are the same as in the first embodiment, and the molding laminate sheet 11 has substantially the same effects as those in the first embodiment.

However, since this polyolefin resin layer 13 functions as the resin base material itself of the soft resin molded product or as an intervening layer between another resin base material and the styrene thermoplastic elastomer layer 12, its hardness and thickness may vary. can be arbitrarily determined as long as it is moldable. Further, the polyolefin resin layer 13 may be formed of hard glass fiber-filled polypropylene or the like.

After heating and softening this molding laminated sheet 11,
For example, by directly blow molding this, a soft resin molded product 18 as shown in FIG. 5 can be obtained.

In the soft resin molded product 18 thus obtained,
The styrene thermoplastic elastomer layer 12 functions as a soft layer on the surface that provides a soft feel. On the other hand, the polyolefin resin layer 13 functions as the resin base material itself.

Note that if a soft resin molded product is molded using the molding laminated sheet 11 as in the first embodiment, the polyolefin resin layer 13 is an intervening layer between another resin base material and the styrene thermoplastic elastomer layer 12. It will function as.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, and may be modified and embodied as desired without departing from the spirit of the invention, for example, as described below.

(1) On the surface of the polyolefin resin layer 3 in the first embodiment or on the surface of the styrene thermoplastic elastomer layer 12 in the second embodiment, other decorative layers, such as a paint layer, cloth H1
A flocked layer or the like may be provided.

(2) The method of molding a soft resin molded product using the molding laminated sheet of the present invention is not limited to the above-mentioned insert injection molding and blow molding, but includes, for example, vacuum molding, insert injection molding,
Stamping molding may also be used.

Effects of the Invention As detailed above, the present invention has excellent bondability between the styrene thermoplastic elastomer layer and the polyolefin resin 11td5ii, and provides a desired soft texture even if the styrene thermoplastic elastomer layer has a small thickness. Not only can this molding laminated sheet be used to mold a soft resin molded product, it also has the excellent effect of preventing the styrene thermoplastic elastomer layer from being crushed.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged cross-sectional view showing a first embodiment of a laminated sheet for molding embodying the present invention, and Fig. 2 is a cross-sectional view showing a method for molding a soft resin molded product using the laminated sheet for molding. , Fig. 3 is a cross-sectional view of the same soft resin molded product, Fig. 4 is a partially enlarged cross-sectional view showing a second example of the laminated sheet for molding, and Fig. 5 is a soft resin molded using the same laminated sheet for molding. FIG. 3 is a cross-sectional view of the molded product.

Claims (1)

[Claims] 1. A laminate sheet for molding, which is formed by laminating a styrene thermoplastic elastomer layer (2, 12) and a polyolefin resin layer (3, 13). 2. The styrenic thermoplastic elastomer layer (2, 12
2. The laminate sheet for molding according to claim 1, wherein the styrenic thermoplastic elastomer forming the elastomer is a block polymer having polybutadiene, polyisoprene, or an olefin copolymer as a soft segment and polystyrene as a hard segment. 3. The styrenic thermoplastic elastomer layer (2, 12
) is a block polymer having polybutadiene, polyisoprene, or an olefin copolymer as a soft segment and polystyrene as a hard segment, and the soft segment is hydrogenated. A laminated sheet for molding according to scope 1.