JPS62149431A - Laminated product of polyolefin group resin foam - 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 (Field of Industrial Application) The present invention relates to a laminated product of polyolefin resin foam having excellent moldability.

(Prior art) Polyolefin resin foams have traditionally been used for a variety of purposes as products in various forms by vacuum forming, compression molding, etc. However, these foams have not been commercialized as individual foams. It was rarely used, and it was usually used in the form of a laminated product that was bonded to a base material such as a plastic sheet or fabric made of polyvinyl chloride or polyolefin using heat fusion or adhesive.

The moldability of such laminated products differs significantly depending on the properties of the base material to be laminated to the foam, even if the foam itself has good moldability. No matter how much the moldability of the product is improved, the moldability will differ depending on the type of base material, so the laminated foam layers will be destroyed during the molding process, and 1q of good quality products will be lost.
The problem was that I couldn't do it.

(Problems to be Solved by the Invention) The object of the present invention is to prevent the foam layer from being damaged by the type of skin base material used for the Ii layer, and to provide good vacuum moldability and compression moldability. To provide laminated products with:

(Means for Solving the Problems) The object of the present invention is to provide an apparent density of 0.025 to 0.100 CI/cc, 140
The product of breaking strength and breaking elongation at °C is at least 3
0 Kq/cm2・% and a drawing ratio of at least 0°5 at 130 to 190°C, the tensile stress at 50% and 100% elongation is not more than twice that of the polyolefin foam. This can be achieved by a laminated product of polyolefin resin foam made by laminating certain skin base materials.

First, in the present invention, the foam constituting the laminated product is
．． It is necessary to have an apparent density in the range of 0.025 to 0.100 Q/cc, and a product of breaking strength and breaking elongation at 140° C. of 30 Kg/cm 2 ·5 or more.

Here, the apparent density (C1/CC) is a value calculated by accurately cutting the foam into 10 cm square pieces, measuring the shape and thickness, and using the following formula.

Apparent density = Foam weight ffi/100x Foam thickness Cm) When the value of this apparent density is smaller than 0.025Q/cc, the stress of the foam is small, and the compression recovery and shape retention properties are low. 0.100g/cc
If it is larger than this, the compression hardness will increase and the cushioning properties will decrease, making it undesirable for molded products such as automobile interior materials.

The feature of the present invention is closely related to the characteristics of the skin base material to be laminated to the foam, which will be described later.
g/cm2.5 or more.

Here, the breaking strength and breaking elongation of the foam at 140° C. are measured as follows.

A heating furnace (
Using the attached device (manufactured by Daiei Kagaku Seiki Co., Ltd.), the test specimen was
Handle it in a dumbbell shape (No. 1 shape) according to the measurement method specified in JIS-6301, and
Measurement was carried out at 140° C. and at a tensile speed of 500 mm/min according to the measuring method specified in 767.

The heating time of the test specimen was 5 minutes, and the strength at break and elongation were calculated from the recording paper. On the other hand, regarding the unit of strength, in the case of a foam alone, the stress per unit area (Kq
When comparing the stress of the skin material and the foam, the stress per width of the test piece (Kch/cm) was used to compare the stress of the skin material and the foam because the thickness of the skin material was small.

If the product of breaking strength and breaking elongation determined by the above measurement method is lower than 30t4C7/cm2・%, when laminated with the skin base material and molded (vacuum, compression),
This is undesirable because the foam lacks the stress and elongation necessary for molding, causing problems such as the foam breaking or peeling at the rough bonding interface, making it impossible to obtain a practical molded product. . Further, the upper limit of the product of breaking strength and breaking elongation is not particularly limited, but is preferably about 600K.
7 Cm2・% is good.

As a method for producing a polyolefin resin foam having such an apparent density and the product of breaking strength and breaking elongation at 140°C, various polyolefin resins such as these, polyethylene, polypropylene, polyethylene-
It can be obtained by a radiation crosslinking foaming method, a chemical crosslinking foaming method, etc. using a propylene comonolymer as a raw material. Specifically, the polyolefin resin is mixed with a known thermally decomposable blowing agent, such as azodicarbonamide, dinitrosopentamethylenetetramine, etc., and, if necessary, a crosslinking agent that generates radicals by heating, and then the blowing agent is mixed with a crosslinking agent that generates radicals when heated. and molding by holding at a temperature where the crosslinking agent does not decompose.
For example, it is formed into a sheet. This formed sheet material is cross-linked by any known method such as ionizing radiation cross-linking method or chemical cross-linking method so that the gel fraction becomes 15-60%, preferably 20-40%. do.

More specifically, in the case of the ionizing radiation crosslinking method, α, β, γ, X-rays, electron beams, neutron beams, etc. are used as high-energy rays, and a high-energy electron beam irradiation machine is usually used. The sheet material is crosslinked by irradiating the sheet with an electron beam at a dose of ~50 M r a d. In this case, 0.1 to 10 parts by weight of various known crosslinking aids, such as divinylbenzene, diallyl phthalate, trimethylolpropanemyl acrylate, etc., are added to the blend polymer of the present invention and crosslinked with electron beams. Good too. Instead of this radiation irradiation, it is also possible to add an ultraviolet sensitizer such as benzophenone and crosslink by irradiating ultraviolet rays.

In addition, in the case of chemical crosslinking method, dicumyl peroxinide,
Cross-linking method using an organic peroxide such as tertiary butyl peroxide, and further kneading vinyl silane such as vinyl trimethoxysilane with these cross-linking agents to form a compound (see graph 1), followed by cross-linking by siloxane condensation reaction. A silane crosslinking method or the like can be applied as appropriate.

The molded article thus subjected to '+F7' is heated in a hot air atmosphere or on a bath to convert it into a foam by rapidly decomposing the blowing agent contained inside the molded article.

In addition, to the extent that the object of the present invention is not impaired, the composition used for producing the foam of the present invention may include lubricants, antioxidants,
Ultraviolet absorbers, colorants, antistatic agents, flame retardants, and other various additives can be blended within the range that can achieve the desired purpose.

Furthermore, the polyolefin resin foam used in the present invention can be laminated by applying an adhesive to at least one surface thereof by corona discharge treatment, coating, etc., to improve its workability. Various processing techniques can be applied, such as laminating PlusDeck film, Sea 1~, other foam sheets, or metal foils, or imparting a composite structure by extrusion lamination or the like.

A polyolefin resin foam having such an apparent density and a product of breaking strength and breaking elongation at 140°C of 30 K O/cm 2 % or more has a vacuum forming drawing ratio, particularly 130 to 190°C. The lower vacuum forming drawing ratio is 0.
It is preferably 5 or more, and by having this vacuum forming drawing ratio of 0.5 or more, extremely excellent vacuum formability can be imparted to the laminated product.

Next, as skin base materials laminated on such polyolefin resin foam, there are polyvinyl chloride sheets, polyolefin sheets, polyurethane sheets, and fiber fabrics. % and 100%
It is necessary that the tensile stress during elongation is 2.0 times or less, preferably 1.5 times or less, than that of the polyolefin foam.

That is, if the tensile stress of the skin base material at 50% and 100% elongation is greater than 2.0 times that of the foam on which it is laminated, due to the stress difference between the foam and the skin base material during the molding process, This is not preferable because the foam may be destroyed or peeling may occur at the bonded surfaces (interfacial peeling), making it impossible to obtain the desired molded product.

Methods for laminating the skin base material onto the foam include a method of bonding the two using an adhesive, a lamination method using extrusion, a bonding method using a flame method, etc., but there are no particular limitations. It's not something you can do.

[Effect of the invention] The thus obtained laminated product of the present invention has excellent vacuum formability and compression moldability, and moreover, the laminated product has excellent vacuum formability and compression formability, and moreover, the laminated product has excellent vacuum formability and compression formability, and moreover, the laminated product has excellent vacuum formability and compression formability. The resulting foam layer did not peel off from the marking material or break, and the quality and shape were poor.

Therefore, it has excellent moldability in many applications,
For example, in the composite molding of the binding of "A4") J (doors, instrument panels, etc.) in automobiles, 1 to 1 - almost no trouble occurs.

EXAMPLES Hereinafter, the effects of the present invention will be explained in more detail with reference to Examples.

Examples 1 to 4, Comparative Examples 1 to 2 70% polypropylene resin with melt index (M!) of 1.5, which is made by random copolymerization of 4% ethylene, Ml is 2.01, and polyethylene resin 3 has a density of 0.930.
0%, azodicarbonamide as a foaming agent, divinylbenzene as a crosslinking aid, and "I-21Nol" as a stabilizer were mixed uniformly and then molded into a sheet using an extruder.

After irradiating the obtained sheet with an electron beam, it was crosslinked and foamed on a heated salt bath to create six types of foams having the characteristic values shown in Table 1.

A polyvinyl chloride sheet was laminated on these foams as a skin base material and bonded using an adhesive to obtain a laminated sheet. This laminated sheet has a diameter of 500 mmφ and a depth of 250 mm.
Vacuum forming using a mold of mm (L/D=0.5),
The state of destruction at the bottom (destruction d'3 of the foam and interfacial peeling of the joint surfaces) was investigated and compared. These results are also shown in Table 1. From the table, it can be seen that a laminated one-piece product that satisfies the conditions stipulated in the present invention has good vacuum formability and compression formability, and the laminated foam does not break during molding, and the foam and skin do not break during molding. It can be seen that it has extremely excellent mechanical performance without peeling from the joint surface with the base material.

Claims (2)

[Claims] (1) Apparent density is 0.025 to 0.100 g/cc, 1
The product of breaking strength and breaking elongation at 40°C is at least 30 Kg/cm^2%, and 130 to 190°C
A polyolefin resin foam formed by laminating a skin base material whose tensile stress at 50% and 100% elongation is not more than twice that of the polyolefin foam at 50% and 100% elongation to a polyolefin foam whose forming drawing ratio is at least 0.5. Body laminated products. (2) In claim 1, the skin base material is a laminate of polyolefin resin foams whose skin base material is a base material obtained from the group consisting of a polyvinyl chloride sheet, a polyolefin sheet, a polyurethane sheet, and a fiber fabric. product.