JPH09109302A - Manufacture of foamed laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for making a foamed laminated sheet in which in the case of integral molding of sheet-shaped polypropylene foam laminated with a skin material and molten polyolefine, unevenness on the surface of the skin material which can be caused by the crush of the polypropylene foam is prevented. SOLUTION: Polyolefin 5 is integrated with a laminate 4 in which a skin material 1, sheet-shaped polypropulene foam 2, and a polypropylene layer 3 of 50μm or more thickness are laminated in this order by laminating the polyolefin 5 on the surface of the polypropylene layer 3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a foam laminated sheet.

[0002]

2. Description of the Related Art Conventionally, as a foamed laminated sheet of this type, there is one described in, for example, Japanese Patent Application Laid-Open No. 2-102034. The foamed laminated sheet is obtained by laminating a cloth material such as a soft vinyl chloride sheet on the surface of a polypropylene resin foam, setting the same in a molding die, and appropriately heating and pressurizing it. The melted polyolefin resin is laminated on the foam side, and this polyolefin resin plate is attached and integrated.

[0003]

However, in the prior art, when the molten polyolefin resin is laminated on the foam side, the foam is softened by the temperature and pressure of the molten resin, and is crushed into a thin uneven thickness. However, there is a problem in that the thickness of the foamed material is partially changed and the laminated skin material is affected to cause unevenness on the surface of the skin material to impair the aesthetic appearance.

In view of the above problems, an object of the present invention is to integrally mold a polypropylene resin foam having a skin material stuck thereto and a molten polyolefin resin,
The polypropylene resin foam is crushed,
It is an object of the present invention to provide a method for producing a foamed laminated sheet which does not cause unevenness on the surface of the skin material.

[0005]

The present invention has been made in order to achieve the above-mentioned object, and a skin material, a sheet-like polypropylene resin foam and a polypropylene resin layer having a thickness of 50 μm or more are provided. The molten polyolefin resin is laminated on the polypropylene resin layer surface of the laminated body laminated in this order to be integrated.

The skin material used in the present invention is a cloth-like material using natural or artificial fibers, a polyvinyl chloride resin sheet,
It is a known sheet such as a thermoplastic elastomer sheet, a laser, or a mixed sheet of a polyvinyl chloride resin and an ABS resin in which acrylonitrile, butadiene, and styrene are copolymerized, among which a polyvinyl chloride resin sheet. -G is preferred.

Examples of polypropylene resins include, for example:
Homopolymer of propylene, block copolymer or random copolymer with olefinic monomer such as ethylene having 50% by weight or more of propylene component, terpolymer of olefinic monomer such as ethylene and butene A polymer or the like is used.

As the thermal decomposition type foaming agent, any one can be used as long as it has a thermal decomposition temperature higher than the melting temperature of the resin composition, for example, azodicarbonamide or the same as or equivalent to azodicarbonamide. Examples thereof include hydrazide carbonamide, azodicarboxylic acid amide, azodicarboxylic acid barium salt, dinitrosopentaethylenetetramine, nitrosoguanidine, p, p′-oxybisbenzenesulfonyl semicarbazide, which have higher thermal decomposition temperatures. These thermal decomposition type foaming agents may be used alone or in combination of two or more kinds.
The content of the thermal decomposition type foaming agent is 0.01 of the propylene resin.
-30 wt% is preferable, and 0.05-15 wt% is preferable.

As the crosslinking accelerator, for example, divinylbenzene, diallylbenzene, divinylnaphthalene, polyethylene dimetallate, trimethylolpropane metachlorate, triallyl isocyanurate and the like are used. These cross-linking accelerators may be used alone or in combination of two or more. The content of the crosslinking accelerator is preferably 0.01 to 30% by weight of the propylene resin,
0.05 to 15% by weight is suitable.

The peroxide used in combination with the crosslinking accelerator for chemical crosslinking is, for example, methyl ethyl ketone peroxide.
Oxide, t-butylperoxide, dicumylper
Oxide or the like is used. The content of the peroxide is preferably 0.01 to 10% by weight of the propylene-based resin, and is 0.1.
05 to 5% by weight is suitable.

The expandable polypropylene resin composition used for producing the polypropylene resin foam of the present invention includes a polypropylene resin, a thermal decomposition type foaming agent,
A cross-linking accelerator, a cross-linking accelerator and, if necessary, a peroxide, an antioxidant, a pigment and other additives are added.

In order to produce a continuous sheet type polypropylene resin foam, the above-mentioned expandable polypropylene type resin composition is extruded at a temperature below the decomposition temperature of the foaming agent to form a polypropylene type resin continuous sheet state. The product is prepared and continuously heated and foamed in a foaming furnace to form a foamed sheet and wound up.

If necessary, a crosslinking treatment may be carried out before foaming. As the crosslinking treatment method, ionizing radiation may be applied or a chemical crosslinking agent such as peroxide may be mixed and heated. And a treatment method of crosslinking the polypropylene resin.

The density of the polypropylene resin foam is
0.02-0.2 g / cc is preferable, low density foam is preferable in consideration of cost reduction, and further considering heat resistance and pressure resistance during molding, 0.05-0.11 g / cc is obtained. It is suitable.

The polypropylene resin layer used in the present invention is a homopolymer of propylene, a block copolymer with an olefinic monomer such as ethylene having 50% by weight or more of a propylene component, or a random copolymer. Examples thereof include copolymers, terpolymers of olefinic monomers such as ethylene and butene, and polypropylene-based resins may be filled with inorganic compounds such as talc, silicic acid and calcium carbonate. . Also, the thickness of the polypropylene resin layer is 50
If it is thinner than μm (for example, 30 to 40 μm or less),
During molding, the heat of the melted polyolefin resin is easily transferred to the surface of the polypropylene resin foam sheet,
Since the polypropylene resin foam is softened and crushed when the polyolefin resins are laminated and integrated by stamping molding or the like, the thickness of the polypropylene resin layer is 50 μm or more. If it is too thick, unevenness may occur on the surface of the skin material.
900 μm is preferable.

There are various methods for laminating the polypropylene resin layer on the polypropylene resin foam, but it is preferable to adhere the both. The method of adhering these includes heat fusion, adhesion with an adhesive, and the like, but the heat fusion is simple and easy to adhere, which is preferable. As a method for forming a polypropylene resin foam by heat-sealing and forming a resin layer on the polypropylene resin foam later, a method of extrusion laminating a polypropylene resin on the polypropylene resin foam, a sheet shape of the polypropylene resin There is a method of heat lamination of the above. Further, as described above, in addition to the method of bonding, a polypropylene resin layer is provided in advance on the foamable polypropylene resin composition sheet before the foam is made, and the polypropylene resin layer is foamed to have a resin layer on one side. There is also a method of making a polypropylene resin foam.

The polyolefin resin used in the present invention is, for example, propylene resin, or propylene and α-olefin are random, random-block,
Examples thereof include a copolymer containing propylene as a main component, which is copolymerized in a block form, and a polyethylene resin may be mixed therein. Further, an inorganic compound such as talc, silicic acid or calcium carbonate may be mixed with these resins as a filler as long as the characteristics of the aggregate resin are not impaired.

In the present invention, there are various methods for laminating the polyolefin resins to form an integral body, but the stamping molding method is preferable. What is this stamping molding method?
Molten polyolefin resin is injected into the lower mold of the mold, and a laminate obtained by laminating a skin material, a polypropylene resin foam, and a polypropylene resin layer is sandwiched between the upper mold and the lower mold, This is a method of pressurizing inside and integrally molding.

(Function) Since the laminated body in which the skin material, the sheet-shaped polypropylene resin foam and the polypropylene resin layer having a thickness of 50 μm or more are laminated in this order is used, the polypropylene resin foam and the base are used. The polypropylene-based resin layer is interposed between the material and the polyolefin-based resin, the molten polyolefin-based resin does not come into contact with the polypropylene-based resin foam, and the polypropylene-based resin foam is not crushed. Further, since the polypropylene resin layer and the polyolefin resin are both olefin resins, they are fused and integrally molded.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 (a) is an explanatory view showing a state in which a molten polyolefin resin is injected into the laminated sheet and the mold, and FIG. 1 (b) shows a state in which pressure is applied in the mold to integrally mold it. 2 is a perspective view of the foam laminated sheet obtained by the manufacturing method of the present invention.

In FIG. 2, a skin material 1, a polypropylene resin foam 2 and a polypropylene resin layer 3 having a thickness of 50 μm or more are melted on the surface of the polypropylene resin layer 3 of a laminate 4 which is sequentially laminated in this order. 2 shows a foamed laminated sheet formed by laminating the above-mentioned polyolefin resin 5 into an integrated body.

Example 1 This foamed laminated sheet is manufactured as follows. First, ethylene containing 4% ethylene
5 kinds of compositions were prepared by mixing 70 parts by weight of propylene random copolymer with 30 parts by weight of low density polyethylene resin, 3 parts by weight of divinylbenzene and 4,6,8,10,12 parts by weight of azodicarbonamide. Five kinds of sheets having different contents of the foaming agent were prepared by extrusion molding. Next, these 5 types of sheets were irradiated with an electron beam of 4 megarads to crosslink a random copolymerized polypropylene resin containing 4% ethylene, and were continuously foamed at 250 degrees in a heating foaming furnace, each of which had a substantially uniform thickness. Five types of sheet-shaped polypropylene resin foams 2 having a foaming ratio (foam density) of approximately 3 mm were prepared.

Next, by extrusion lamination, on one surface of each of the five types of sheet-like polypropylene resin foams 2 having different expansion ratios (foam density), ethylene containing 4% ethylene was added. A propylene random copolymer (melt index 30) was heat-sealed to form a polypropylene resin layer 3 having a thickness of 50 μm. Next, the skin material 1 is applied to the other surface of the sheet-shaped polypropylene resin foam 2.
(A vinyl chloride resin sheet having a thickness of about 0.5 mm) is subjected to thermal lamination using a two-component urethane resin adhesive, and the skin material 1 is laminated on the sheet-shaped polypropylene resin foam 2. did.

Next, the polyolefin resin 5 (melt index 30) is formed on the lower mold 62 of the mold 6 almost in the center of the recess.
4% ethylene-containing ethylene-propylene random copolymer is injected to laminate a skin material 1, a sheet-like polypropylene resin foam 2, and a polypropylene resin layer 3 into a laminated sheet 4. Is sandwiched between the upper mold 61 and the lower mold 62,
The convex portion of the upper die 61 was pressed down to form a foamed laminated sheet.

Example 2 This foamed laminated sheet is different from Example 1 in that the thickness of the polypropylene resin layer 3 (100 μm) provided on one surface of the sheet-shaped polypropylene resin foam 2 is 100 μm. ) Is different and the manufacturing method is the same as that of the first embodiment, and thus the description thereof is omitted.

Example 3 This foamed laminated sheet differs from Example 1 in that the thickness of the polypropylene resin layer 3 (200 μm) provided on one surface of the sheet-shaped polypropylene resin foam 2 is 200 μm. ) Is different and the manufacturing method is the same as that of the first embodiment, and thus the description thereof is omitted.

Example 4 This foamed laminated sheet differs from Example 1 in that the thickness of the polypropylene resin layer 3 (300 μm) provided on one surface of the sheet-shaped polypropylene resin foam 2 is 300 μm. ) Is different and the manufacturing method is the same as that of the first embodiment, and thus the description thereof is omitted.

Comparative Example 1 This foamed laminated sheet differs from Example 1 in that the thickness of the polypropylene resin layer 3 (30 μm) provided on one surface of the sheet-shaped polypropylene resin foam 2 is 30 μm. ) Is different and the manufacturing method is the same as that of the first embodiment, and thus the description thereof is omitted.

(Comparative Example 2) This foamed laminated sheet differs from the foamed laminated sheet in that there is no polypropylene resin layer 3 on one surface of the sheet-shaped polypropylene resin foam 2. Since the other manufacturing methods are the same as those in the first embodiment, the description thereof will be omitted.

Next, in order to explain the features of the present invention, data on the unevenness of the surface of the skin material 1 after molding of Examples 1, 2, 3 and 4 of the present invention and Comparative Examples 1 and 2 Is shown in Table 1.

[0031]

[Table 1]

As shown in Table 1, Examples 1, 2, 3
And 4, the sheet-shaped polypropylene resin foam 2
Since the thickness of the polypropylene resin layer 3 provided on one surface is 50 μm or more, there is no unevenness on the surface of the skin material 1 after molding (measurement of the density of the polypropylene resin foam and the surface of the skin material after molding). The criteria for determining the quality of the unevenness condition are described later.) A good foamed laminated sheet could be obtained. For Comparative Example 1, polypropylene-based resin layer 3
Since the thickness of 30 μm is used, the skin material 1 after molding
In the comparative example 2, since the polypropylene-based resin layer 3 was not present, the surface of the skin material 1 after molding was markedly uneven, and in each case, a good foamed laminated sheet was obtained. It was not obtained and was not practical.

The density of the sheet-shaped polypropylene resin foam 2 was measured as follows. A sheet-shaped polypropylene resin foam 2 before extrusion lamination of an ethylene-propylene random copolymer and thermal lamination of the skin material 1 is used. The sheet was cut into a width of 10 cm, the weight and volume of this cut sheet were measured, and the weight was divided by the volume to obtain the density. The criteria for determining the quality of the unevenness of the surface of the skin material 1 after molding were as follows. One surface of the skin material of the foamed laminated sheet thus obtained was visually and visually observed and judged as follows. ⊚: No unevenness observed with a magnifying glass. ◯: There is no unevenness when visually observed. X: Some irregularities are observed visually. XX: Visual observation reveals some severe unevenness. XXX: Severe irregularities are seen on the front surface when visually observed.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there are design changes and the like within the scope not departing from the gist of the present invention. Included in the present invention.

[0035]

As described above, in the foamed laminated sheet of the present invention, the skin material, the sheet-shaped polypropylene resin foam and the polypropylene resin layer having a thickness of 50 μm or more are laminated in this order. Since the laminated body is used, the polypropylene resin layer is interposed between the sheet-shaped polypropylene resin foam and the melted polyolefin resin, and the melted polyolefin resin has a sheet shape. The polypropylene resin foam does not directly hit the polypropylene resin foam and is not crushed. or,
Since the polypropylene resin layer and the polyolefin resin are both olefin resins, they are fused and integrally molded. Molding is easy and convenient.

[0036]

[Brief description of the drawings]

FIG. 1 (a) is an explanatory view showing a state where molten polyolefin resin is injected into a laminated sheet and a mold, FIG.
(B) is an explanatory diagram showing a state in which pressure is applied in the mold to integrally mold.

FIG. 2 is a perspective view of a foam laminated sheet obtained by the manufacturing method of the present invention.

[Explanation of symbols]

 1 Skin material. 2 Polypropylene resin foam. 3 Polypropylene resin layer. 4 Laminated body. 5 Polyolefin resin. 6 formwork. 61 Upper mold. 62 Lower mold.

Claims (1)

[Claims] 1. A polyolefin resin melted on a polypropylene resin layer surface of a laminate in which a skin material, a sheet-shaped polypropylene resin foam and a polypropylene resin layer having a thickness of 50 μm or more are laminated in this order. A method for producing a foamed laminated sheet, which comprises laminating and integrating them.