JPH10119160A - Lightweight laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve deformation such as warpage while using a foam core material and to upgrade lightweight properties by specifying softening point and loads of petroleum resin contained in polyolefin resin, and laminating metal plate-like material on both surfaces of obtained foam core sheet-like material. SOLUTION: 10 to 50 pts.wt. of petroleum resin having a softening point of 100 to 160% is contained in 100 pts.wt. of polyolefin resin. As the petroleum resin, alicyclic saturated hydrocarbon resin is preferable. In the obtained foam core sheetlike material, various type filler of an amount of the degree substantially not lowering its lightweight properties and smoothness can be added. Metal plate-like materials to be laminated on both surfaces of the sheet-like material may be the same or different metals, and thicknesses of the front and rear surface metal-like materials can be the same or different. As the metal plate-like material, aluminum or aluminum alloy is particularly preferable in view of lightweight. These metals have no problem even if they are surface treated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0010]

TECHNICAL FIELD The present invention relates to a laminated board comprising a foamed core sheet (general term for film or sheet) containing a polyolefin resin and a petroleum resin and a metal plate (general term for plate or foil). In particular, the present invention relates to a lightweight laminate excellent in lightness and flatness in shape (hereinafter sometimes simply referred to as a laminate).

[0011]

2. Description of the Related Art A metal / resin / metal sandwich laminate of a metal plate and a resin material is well known. The laminate has smooth surface properties and lightness close to that of a resin, but has the same surface properties as metal, and has better mechanical properties and heat resistance than a sheet material made of a resin alone as a core material. It has nature.

[0012]

In the above laminate, the surface has the property of a metal plate-like material due to the sandwich structure, and the weight is reduced by the core material. In recent years, when used for various applications, a composite board that is lighter and has higher flatness is desired. Light weight, which is one of the features of the laminate, is reduced by foaming the core resin, but the mechanical properties of the core decrease as the expansion ratio increases. Since the effect of the metal plate on the surface is greater than that of the core material, a decrease in the mechanical properties of the core material does not significantly affect the mechanical properties of the composite plate. However, when laminating the core sheet and the metal plate, the core sheet having a high expansion ratio is crushed and thinned or warped, so that a lightweight and flat composite board cannot be obtained. The present inventors have conducted intensive research on a method of obtaining a metal / resin / metal sandwich laminate having a small weight and a small deformation such as warpage while using a foamed core material sheet.

[0013]

As a result, a laminated plate in which a metal plate is laminated on both sides of a foamed core sheet containing a petroleum resin in a specific ratio, the core material does not collapse at the time of lamination, and the surface of the laminated plate does not collapse. The inventors have found that the present invention has good properties and completed the present invention based on this finding. That is, according to the present invention, the softening point is 100 ° C. with respect to 100 parts by weight of the polyolefin resin.
As described above, it is an object of the present invention to provide a lightweight laminate characterized in that a metal plate is laminated on both surfaces of a foam core sheet containing 10 to 50 parts by weight of a petroleum resin having a temperature of 160 ° C. or lower.
An object of the present invention is to provide an inexpensive laminate having excellent flatness and sufficient lightness.

Hereinafter, the present invention will be described in detail. Examples of the olefin resin used in the present invention include the following: high-density polyethylene (HDPE), medium-density polyethylene (MDPE) or linear low-density polyethylene (L-LDPE) or ultra-high-molecular-weight polyethylene (UHMW-PE). ); A homopolymerized polypropylene or a copolymerized polypropylene; a polyolefin-based resin such as a copolymer of ethylene and propylene as a main component and another α-olefin or a polar monomer in addition to poly-1-butene; Any resin such as a mixture of two or more of these resins may be an olefin-based resin. In addition, maleic acid, acrylic acid, unsaturated carboxylic acid such as fumaric acid, a modified resin obtained by copolymerizing or grafting a derivative such as an acid anhydride or ester thereof, or ionizing radiation treatment of the resin, A modified resin cross-linked by a cross-linking agent can also be used depending on the application.

The petroleum resin used in the present invention has a softening point of 100 ° C. or more and 160 ° C. or less, and is preferably an alicyclic saturated hydrocarbon resin. If the softening point is less than 100 ° C., the heat resistance of the composite plate is reduced, causing a problem in smoothness.
If the temperature exceeds 0 ° C., the compatibility with the olefin resin is deteriorated, the surface properties of the composite board are reduced, and the flatness is deteriorated. The petroleum resin content used in the present invention is olefin resin 10
The petroleum resin is used in an amount of 10 to 50 parts by weight, preferably 20 to 40 parts by weight, based on 0 parts by weight. When the content of the petroleum resin is 10 parts by weight or more and 50 parts by weight or less, the effect of improving lightness and smoothness is obtained, and industrially stable production becomes possible.

[0016] In addition to the olefin resin and the petroleum resin, the foamed core sheet used in the present invention may contain various fillers in such an amount that the lightness and smoothness are not substantially reduced. As filler, carbon fiber,
Examples include fibrous reinforcing materials such as vinylon fibers, flake-like fillers such as mica and talc, spherical fillers such as glass beads, and amorphous fillers such as calcium carbonate, wood chips, and wood powder. The surface of these fillers is preferably subjected to a treatment for imparting affinity to the resin to be compounded. Examples of such treatment include addition of an unsaturated carboxylic acid or an acid anhydride thereof, addition of an unsaturated amine, and rubbery coating. In addition to these fillers, various additives usually added to olefin resins, such as antioxidants, ultraviolet absorbers, antistatic agents, neutralizing agents, pigments, foaming agents, lubricants, copper antioxidants, neutralization Agents, hygroscopic agents, extenders, coloring agents, deterioration inhibitors, lubricants and the like can be added as necessary.

The sheet material of the foamed core material used in the present invention comprises:
It is a generic term for sheets including film, with a thickness of 1 mm or more,
8 mm or less is preferable, and more preferably 2 mm or more and 5 mm
The thickness is as follows. When the thickness of the resin sheet is in this range, the resin sheet can be used as a laminate having a small warpage and deformation, and is excellent in properties as a lightweight composite board. As a method for producing pellets of the foamed core material sheet used in the present invention, a method of kneading in a heated and melted state using a generally used apparatus such as a screw extruder, a high-speed mixer roll, and a Banbury mixer can be used. it can. As a method for foaming the foamed core material sheet used in the present invention, a method of directly injecting gas at the time of sheet molding or a method of adding a chemical foaming agent can be used. The gas used at this time is desirably nitrogen gas or carbon dioxide gas, and the chemical foaming agent used is a foaming agent such as a sulfonic acid hydrazide compound, an azo / diazo compound or sodium bicarbonate. The expansion ratio is desirably 2 times or more and 5 times or less, and indicates a value obtained by dividing the sheet specific gravity at the time of no foaming by the sheet specific gravity after foaming. If the expansion ratio is less than 2 times, the weight of the core material of the lightweight laminate becomes heavy, and if it exceeds 5 times, the physical properties are remarkably deteriorated, which is not practical.

The metal plate used in the present invention is a general term for a plate or a foil and includes aluminum, aluminum alloy,
Iron, stainless steel, steel, galvanized steel, tinned steel, corrosion-resistant steel, copper, copper alloy, titanium, and the like are used. Particularly, a metal plate made of aluminum or an aluminum alloy is preferable in terms of weight reduction. There is no problem even if these metals are surface-treated. The metal plate attached to both sides of the foamed core sheet may be the same metal on the front and back or different metals, and the thickness of the metal on the front and back may be the same or different. The thickness of the metal plate is preferably from 50 to 1000 μm, more preferably from 100 to 600 mm.
If the thickness of the metal plate is less than 50 μm, sufficient surface properties are likely to deteriorate, which is not preferable. On the other hand, when the thickness exceeds 1000 μm, the price of the laminated plate increases, which causes an economic problem.

The laminate according to the present invention is obtained by laminating a metal plate on both sides of a foam core material sheet, and obtains a strong adhesive force by using an adhesive or an adhesive film therebetween. The foamed core material sheet used in the present invention preferably has a flexural modulus of 0.3 GPa or more and a flexural strength of 7.0 MPa or more, more preferably a flexural modulus of 0.4 GPa or more,
The bending strength is 8.0 MPa, and the effect of improving the mechanical properties can be obtained in this range. The laminate of the present invention is preferably formed by laminating a metal core having a thickness of 50 to 1000 μm on a foam core material sheet having a thickness of 1 mm to 8 mm, more preferably a foam core having a thickness of 2 mm to 5 mm. This is a laminate in which a metal sheet is laminated with a thickness of 100 to 600 μm on a material sheet.

The laminating method is a method of laminating an adhesive film on both surfaces of a core material sheet at the time of extrusion or applying an adhesive, laminating a metal plate material, and applying heat and pressure, and forming the core material sheet material. After the product is obtained, there is a method in which an adhesive film is bonded or an adhesive is applied, and a metal plate is stacked and heated and pressed to form the product. The heating and pressing method may be either a batch method using a press machine or a continuous method using a roll, but the continuous method using a roll is more efficient. A more preferable laminating method is to overlap the adhesive film between the core sheet and the metal plate, and then press the roll while pressing with a roll or a press. As the adhesive film, a film having a strong affinity for both the core sheet and the metal plate is preferable, and an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, and an ethylene-maleic anhydride copolymer are preferable. And a film formed of a polyethylene maleic anhydride graft copolymer or the like. The thickness of the adhesive film is preferably 20 to 80 μm.

[0021]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The measurement of the flexural modulus and the strength of the core material of the present invention was performed according to JIS K7203. The flatness of the composite plate was evaluated by placing the composite plate on a surface plate and visually checking the deformation and warpage of the composite plate. [Judgment Criteria] ：: Good flatness without deformation / warpage. Δ: Deformation / warpage is slight and flatness is slightly inferior. ×: Deformation / warpage is large and flatness is poor.

Examples 1 to 3 and Comparative Examples 1 to 3 100 parts by weight of a polypropylene homopolymer (abbreviated as PP) having a melt flow rate of 1.0 were mixed with a petroleum resin A (Alcon P-140, manufactured by Arakawa Chemical Industries, softened). (Point: 140 ° C) 25
After that, the mixture was supplied from a raw material supply port using an extruder having a diameter of 60 mm and L / D28, and a carbon dioxide gas was injected from a metering part of the screw.
It was extruded from a T-die at 10 ° C. to obtain a foamed sheet. The pellet was made into a core sheet having a thickness of 3.7 mm, and an adhesive polyolefin resin film (thickness: 30 μm) was sandwiched on both sides thereof, and an aluminum plate (thickness: 150 μm) was sandwiched on both sides thereof. A laminate having a length of 1000 mm, a width of 1000 mm, and a thickness of 4 mm was prepared by pressing under a pressure of 5 cm 2 for 5 minutes to obtain a laminate of Example 1. After evaluating the flatness of each of the laminates, a bending test was performed. Table 1 shows the results. In Examples 2 and 3, petroleum resin A was
Table 1 shows the results in the case of containing 5 parts by weight and 40 parts by weight, and in Comparative Examples 1, 2 and 3 when no petroleum resin A was included, and in the case where 5 parts by weight and 70 parts by weight were included.

Examples 4 to 5 and Comparative Examples 4 to 5 100% by weight of an ethylene-propylene random copolymer having a melt flow rate of 2.2 (abbreviated as R-PP; ethylene content 4 mol% and propylene content 96 mol%) In the section is petroleum resin B (made by Tonex, Escolets 532)
0, softening point: 125 ° C.) After mixing 25 parts by weight, the mixture was supplied from a raw material supply port using an extruder having a diameter of 60 mm and L / D28, and carbon dioxide gas was injected from a metering part of the screw. At a temperature of 200 ° C. to obtain a foamed sheet. The pellet was made into a core material sheet having a thickness of 3.7 mm, and an adhesive polyolefin resin film (thickness: 30 μm) was sandwiched on both sides thereof, and an aluminum plate (thickness: 150 μm) was sandwiched on both sides thereof. pressurized 5 min cm ^2, a vertical 1000m
A laminated board having a thickness of 4 mm and a width of 1,000 mm was prepared. After evaluating the flatness of each of the laminates, a bending test was performed. Table 1 shows the results. Table 1 shows the results of Example 5 in which petroleum resin B was included at 40 parts by weight, and Comparative Examples 4 and 5 in which no petroleum resin B was included and in the case of 5 parts by weight.

Example 6 and Comparative Example 6 100 parts by weight of an ethylene-propylene block copolymer having a melt flow rate of 0.5 (abbreviated as “B-PP”; ethylene content 8 mol% and propylene content 92 mol%) After mixing 25 parts by weight of resin A, the diameter is 60 m
The mixture was supplied from a raw material supply port using an m / L / D28 extruder, carbon dioxide gas was injected from the metering portion of the screw, and extruded from a T-die at a temperature of 200 ° C to obtain a foamed sheet. The pellets were used as a core sheet 3.7 m thick.
An adhesive polyolefin resin film (thickness: 30 μm) on both sides and an aluminum plate (thickness: 150 μm) are further sandwiched on both sides by a hot press at 180 ° C. and a pressure of 7 kg / cm 2 for 5 minutes to give a vertical length of 1,000 mm. A laminated plate having a width of 1000 mm and a thickness of 4 mm was prepared, and a sixth embodiment was obtained.
After evaluating the flatness of each of the laminates, a bending test was performed. Table 1 shows the results. Table 1 shows the results when Comparative Example 6 contained 5 parts by weight of petroleum resin A.

Example 7 and Comparative Examples 7, 8 and 9 100 parts by weight of a high-density polyethylene homopolymer having a melt index of 0.8 (hereinafter abbreviated as “PE”) was added to 100 parts by weight of a petroleum resin C (Alcon P, manufactured by Arakawa Chemical Industries, Ltd.). -115, softening point: 115) After mixing 25 parts by weight and 0.6 parts by weight of a chemical foaming agent, using an extruder having a diameter of 60 mm and L / D28,
The mixture was supplied from a raw material supply port, melt-kneaded at a temperature of 180 ° C., and extruded from a T-die to obtain a foamed sheet. The pellet was made into a core sheet having a thickness of 3.7 mm, and an adhesive polyolefin resin film (thickness: 30 μm) was sandwiched on both sides thereof, and an aluminum plate (thickness: 150 μm) was sandwiched on both sides thereof. A laminate having a length of 1000 mm, a width of 1000 mm, and a thickness of 4 mm was produced by applying a pressure of 5 cm ² for 5 minutes to obtain a seventh embodiment. After evaluating the flatness of each of the laminates, a bending test was performed. Table 1 shows the results. Further, Comparative Example 7 contains 5 parts by weight of petroleum resin B, and Comparative Examples 8 and 9 contain 25 parts by weight of petroleum resin D (Alcon P-90, softening point: 90 ° C.), petroleum resin E (Maruzetsu H-9, manufactured by Maruzen Petrochemical Co., Ltd.
70, softening point: 180) The results of 25 parts by weight are shown in Table 1.

[0026]

The laminate of the present invention has high flatness while being relatively lightweight. For this reason, the laminate of the present invention can be widely used for interior materials such as buildings, outer walls and ceilings and outdoor signs, fences, around bathrooms, etc., verandas, blind boards, doors for interior and exterior members, partition boards. It could be widely used for building materials such as, or for automobile parts.

[0027]

[Table 1] In Comparative Example 3, a stable sheet was not obtained.

Claims (2)

[Claims] 1. A petroleum resin having a softening point of 100 ° C. or more and 160 ° C. or less per 100 parts by weight of a polyolefin resin.
A lightweight laminate in which a metal plate is laminated on both sides of a foamed core sheet containing up to 50 parts by weight. 2. A petroleum resin having a softening point of 100.degree. C. or more and 160.degree. C. or less per 100 parts by weight of a polyolefin resin.
Extruding a foamed core material sheet containing from 50 to 50 parts by weight,
A method of manufacturing a lightweight laminate in which a metal plate is laminated on both sides of the foam core sheet, and the outer metal plate is pressed and laminated.