JPS63209934A - Metal-polypropylene-metal laminated composite body having improved heat resistance - 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 (Industrial Field of Application) The present invention is characterized in that the relationship between the isotactic pentad fraction (P) and the melt flow rate (MP'R) is 1.00
>0,0151ogMF R+ 0.955, or the propylene homopolymer accounts for 70-95% by weight of the total polymerization amount, and then 3% of the total polymerization amount
A propylene-ethylene block copolymer c or less in which 0-5% by weight of ethylene or ethylene and propylene are polymerized in one or more steps, the ethylene content is 3-12% by weight of the total polymerization amount, and these are highly crystalline. called polypropylene. ) is modified with an unsaturated carboxylic acid or its derivative, or a highly crystalline polypropylene containing modified polypropylene is filled with a high concentration of 1s or a mixture of two or more selected from waste paper, pulp, and organic fiber ( The present invention relates to a laminated composite composed of a core material (hereinafter referred to as a core material) and a metal plate.

In recent years, metal plates have been made lighter, have sound absorption properties, vibration damping properties,
Laminated composites that combine metal plates and plastic sheets have been developed from the perspective of providing heat insulation properties, and are widely used in the fields of civil engineering, architecture, automobiles, home appliances, etc.

(Conventional technology and its problems) Some laminated composites using polypropylene resin as the core material have been put into practical use, but baking when painting molded parts must be treated (usually at about 180-200℃). (Heat-treated for 30 minutes.) At times, the core resin melts and flows out from the punched area, blocking the punching area, causing problems in post-processing, and causing excessive slag as the core resin cools and solidifies. Due to shrinkage, there are disadvantages such as deformation, especially near the sheared part, and separation of the interface between the core resin and metal plate.
The reality is that baking cannot be used for parts that go through a painting process.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, a modified polypropylene obtained by modifying highly crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof, or a high crystalline polypropylene containing modified polypropylene, and a specific amount of waste paper, pulp, or organic fiber selected from
By using a polypropylene sheet containing food or a mixture of two or more types as a core material, it has adhesive strength that can withstand secondary processing such as folding, punching, cutting, and deep drawing. Burning during painting also occurs during the processing process, such as flowing out of molten resin from cut or punched parts or dripping of molten resin. ), and there is no thermal deformation near the cut or punched parts, and furthermore, we have found that a metal/polypropylene/metal laminated composite can be obtained that does not cause peeling at the resin-metal interface. The invention has been completed.

As is clear from the above description, the purpose of the present invention is to have a high adhesive strength, to prevent burning during painting, to prevent molten resin from flowing out or to drop during the processing process, and to prevent thermal deformation near the cut portion. An object of the present invention is to provide a metal/polypropylene/metal laminated composite with excellent heat resistance, which does not cause peeling between a core resin and a metal plate.

(Means for solving problems) The present invention has the following configuration.

Isotactic pentad fraction (P) and melt 70-
) (MFR) is 1. OO≧P≧0.015l
Propylene homopolymer with ogMFR+0.955 or the propylene homopolymer accounts for 10-95 of the total polymerization amount
% by weight, then 30-5% by weight of the total polymerized amount of ethylene or ethylene and propylene are polymerized in one or more steps, and the ethylene content is 3-12% by weight of the total polymerized amount.
Propylene-ethylene block copolymer C below,
It is called highly crystalline polypropylene. ) modified with an unsaturated carboxylic acid or a derivative thereof, or highly crystalline polypropylene containing modified polypropylene, mixed with 15-50% by weight of 1ai or a mixture of two or more selected from waste paper, pulp, and organic fibers. A metal/polypropylene/metal laminated composite characterized by using a polypropylene sheet as a core material.

The modified polypropylene used in the present invention is a highly crystalline polypropylene modified with an unsaturated carboxylic acid or a derivative thereof.

Examples of unsaturated carboxylic acids used in the production of the modified polypropylene include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, and citraconic acid. Further, derivatives of unsaturated carboxylic acids include acid anhydrides, esters, amides, imides, metal salts, etc., such as maleic anhydride, citraconic anhydride, itaconic anhydride,
Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, fumaric acid Dimethyl ester, itaconic acid monomethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-NIN-diethylamide, maleimide, N-butylmaleimide, N - Phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, etc. can be mentioned. Among these, it is particularly preferable to use maleic anhydride.

Various known methods can be employed as the modification method. For example, it is carried out by melt-kneading highly crystalline polypropylene and an unsaturated carboxylic acid or its derivative at a temperature equal to or higher than the melting point of the highly crystalline polypropylene in the presence of an organic peroxide.

The amount of the unsaturated carboxylic acid or its derivative used is 0.01-
5% by weight, more preferably 0.05-3% by weight.

In addition, in the present invention, the above-mentioned modified polypropylene is
A mixture of unmodified highly crystalline polypropylene containing at least % by weight can be used. Generally, the amount of unsaturated carboxylic acid or its derivative used is 0.1-1
It is preferable to use 0% by weight of modified polypropylene mixed with unmodified highly crystalline polypropylene in the above-mentioned ratio.

Examples of the highly crystalline polypropylene used in the modified polypropylene and the highly crystalline polypropylene used mixed with the modified polypropylene include JP-A-58-
It can be obtained by the methods described in JP-A No. 104901 and JP-A-58-201816.

That is, the propylene homopolymer can be reacted with an organoaluminum compound (such as triethylaluminum, diethylaluminium chloride, etc., or an organic aluminum compound (1) as an electron donor), for example, with diisoamyl ether. A solid product obtained by reacting the product (4) with titanium tetrachloride (C), a solid product obtained by reacting a Ks electron donor) with an electron acceptor φ), e.g. titanium tetrachloride. Product G) is converted into an organoaluminum compound (
1) i? and an aromatic carboxylic acid ester (5), for example in combination with p-)methyl ruylate, in a molar ratio of said aromatic carboxylic acid ester (5) and said solid product (3) (5)
/(3)=0.1-1O, obtained by polymerizing °propylene in the presence of a catalyst. On the other hand, propylene/ethylene block copolymer is produced by polymerizing 70-95% by weight of propylene based on the total weight in the presence of the above catalyst, and then adding 30-5% by weight of ethylene or ethylene and propylene in one or more steps based on the total weight. to reduce the ethylene content to 3
-12 weight- is a propylene/ethylene block copolymer.

The melt 70-rate of the propylene homopolymer and propylene-ethylene block copolymer of the present invention is 0.1-
20771 l 0 min, preferably 0.3-1 Oli
/ l It is about 0 minutes. In addition, if the modified polypropylene used in the present invention is used, the highly crystalline polynolopylene containing Kuha modified polypyrene may contain other polyolefins, such as ethylene propylene rubber, ethylene polypyrene diene rubber, etc., within a range that does not impair the effects of the invention.
It is also possible to use a mixture of poly-methylpentene, ethylene vinyl acetate copolymer, and the like.

The waste paper used in the present invention is not particularly limited as long as it is paper such as newspaper, cardboard, cardboard, cardboard scraps, etc.

It is preferable to use the waste paper that has been cut or coarsely pulverized into a size of usually 30 m or less, preferably 5111 m or less.

The pulp used in the present invention is groundwood pulp (GP
), sulfite pulp (8P), soda pulp (AP L kraft pulp (KP), semi-chemical pulp (80P)
), semi-ground pulp (CGP), and other wood pulps.

Among these, mechanical pulp (groundwood pulp) obtained from coniferous trees is preferably used because it has long fibers and has fibrillated cell membranes.

The organic fibers used in the present invention are those that do not decompose or melt under the temperature conditions during melting, cross-wiring, or extrusion of the polypropylene composition blended with the organic fibers, or during molding. There are no particular restrictions, and examples include polyamide fibers, polyimide fibers, polyester fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyacrylonitrile fibers, polyurethane fibers, polyalkylene paraoxybenzoate fibers, phenolic fibers, and rayon. fiber, acetate
Cotton fiber, cotton fiber, flax fiber, jute fiber, wool fiber,
Mention may be made of silk fibers etc. and mixtures thereof.

The blending amount of l selected from the above-mentioned waste paper, pulp, and organic fiber or a mixture of two or more thereof is preferably within the range of 15-50% by weight, particularly 20-40%. Preferably, it is % by weight.

1 type selected from waste paper, pulp, and organic fiber 2
If the blending amount of the mixture of two or more species exceeds 50% by weight, the fluidity of the resin during melting will be significantly reduced, making molding difficult. Also, if it is less than 15% by weight, the molten resin will flow out from the cut or punched parts during painting, and the interface between the core resin and the metal plate will peel off. It is not preferable because it gets worse quickly.

The polypropylene sheet used for the core material of the present invention contains heat-resistant stabilizers, weather-resistant stabilizers, and other additives within the range that does not impede its functions.
The sheet may contain a lubricant, a slip agent, a flame retardant, an antistatic agent, a nucleating agent, an inorganic filler, a metal powder, etc.

The polypropylene sheet used for the core material of the present invention is formed into a sheet by a conventionally known method, and the thickness is within the range of 0.1-5 tm, preferably 0.2-2 m. is desirable.

Metal plates used in the present invention include iron, steel, aluminum,
Metal plates of copper, zinc, tin, nickel, titanium, etc., and metal plates of alloys containing one or more of these metals as main components can be used. The thickness of the metal plate is 0.05-
2. Off, preferably 0.15-1. It is Owx.

The metal plate is usually used after its adhesive surface has been subjected to a surface treatment such as degreasing or sandblasting. Furthermore, a primer treatment such as an epoxy resin coating or a chromate treatment may be applied.

The laminated composite of the present invention has a structure in which metal plates whose adhesive surfaces have been surface-treated are laminated on both sides of the polypropylene sheet,
It can be obtained by heat-pressing using a compression molding machine, a hot roll, or the like. The heating temperature at this time is 160-
The temperature is preferably 220°C, and the pressure is 1-50°C.
The pressure is preferably within the range of kg/cIIL2G, and it is desirable to press for 0.1 seconds to 10 minutes under such conditions.

(Effect of the invention) The laminated composite obtained by the present invention can be processed by cutting, punching,
It does not peel off even during secondary processing such as bending and deep drawing, and the burning during painting does not occur during the processing process, as the resin of the core material flows out from the cut surface of the cut section or punched section, and the droplets do not peel off. There is no deformation due to heat, and there is no peeling phenomenon between the metal plate and the core material at the cut portion. Therefore, it can be suitably used in a wide range of applications, such as interior and exterior panels of automobiles, various panels for home appliances and light electrical appliances, and construction panels.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

In addition, the measurement method of various physical properties in Examples was as follows.

■Ethylene content: Infrared absorption spectroscopy ■Melt 70
- Ray) (MFR): ASTM D-1238 (1710 minutes) ■ Isotactic pentad fraction (P): Macromolecules (
macromolecules ) mutual 68f (19'
15) Measured based on.

This is the isotactic fraction in pentad units in the polypropylene molecular chain using U3C-NMR.

[Examples 1 to 6, Comparative Examples 1 to 5] Ethylene content 8.5% by weight, melt flow rate 1.6
Highly crystalline propylene/ethylene block copolymer with J710 min (first stage polypropylene homopolymer near isotactic pentad fraction ψ) = 0.963, melt flow rate (MFR) = 2.1 g/10 min) Coalescence was carried out with 25% by weight of polypropylene modified with 1.5% by weight of maleic anhydride using 0.10% by weight of 1,3-bis(t-butylperoxyisopropyl)benzene as a radical initiator and a melt flow rate of 1. 8.9/10 minutes, used as a filler in polypropylene consisting of 75% by weight of highly crystalline propylene homopolymer with an isotactic pentad fraction of 0.965. Waste paper, mechanical pulp (fiber summary) 3m), 1 denier in thickness, 3n in length, one or a mixture of two or more selected from organic fibers consisting of 65% by weight of polyester fibers and 36% by weight of cotton fibers in proportions shown in Table 1 below. De-cell mixer (product name)
After stirring and mixing for 3 minutes, the mixture was
The resin was extruded using an extruder with a 11T die (vented) at a resin temperature of 190'c to form a sheet with a thickness of 0.411 Im.

In addition, as Comparative Examples 1 to 5, various fillers were blended with the highly crystalline polypropylene used in Examples 1 to 6 in the proportions shown in Table 1 below, and the mixture was stirred and mixed according to Examples 1 to 6. A sheet having a thickness of 0.4 brocade was obtained by extrusion molding.

Next, the surface was cleaned with triclean as a metal plate to a thickness of 0.2
A 7n cold rolled steel plate was prepared.

The sheet was inserted between two steel plates and pressed at 200° C. for 1 minute at a pressure of 20 kg/Ql”Ch to obtain a laminated composite.

The T-peel strength and the state after heat treatment of the laminated composite were evaluated and observed, and the results are shown in Table 1. The T-peel strength was measured in accordance with JXS-6854. However, the tensile speed was 200 MX for 7 minutes.

In addition, heat treatment was carried out by making a test piece by drilling a hole with a diameter of 20111 in the center of a laminated composite that was cut by 20 cIL in length and 110 ff in width, and suspending the test piece in a heating oven maintained at 200°C for 30 minutes. did.

As shown in Table 1, the laminated composite of the present invention, in which one or more mixtures of waste paper, pulp, and organic fibers selected from waste paper, pulp, and organic fibers are blended in a specific ratio as a core material, has high peel strength and can be cut by heat treatment. No molten resin was observed flowing out from the cut portion, and there was no deformation of the cut portion. Further, no peeling phenomenon between the metal plate and the resin layer at the cut portion was observed, and the laminated composite maintained its shape before the heat treatment.

Claims (1)

[Claims] The relationship between isotactic pentad fraction (P) and melt flow rate (MFR) is 1.00≧P≧0.015l
Propylene homopolymer with ogMFR+0.955 or the propylene homopolymer accounts for 70-95% of the total polymerization amount
% by weight, and then 30-3% by weight of the total polymerized amount of ethylene or ethylene and propylene are polymerized in one or more steps, and the ethylene content is 3-12% by weight of the total polymerized amount.
A propylene-ethylene block copolymer (hereinafter referred to as
It is called highly crystalline polypropylene. ) modified with an unsaturated carboxylic acid or its derivative, or highly crystalline polypropylene containing modified polypropylene, blended with 15-50% by weight of one or more mixtures selected from waste paper, pulp, and organic fibers. A metal/polypropylene/metal laminated composite characterized by using a polypropylene sheet as a core material.