JPS63214442A - Metal-polyprolyene-metal laminating 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 Application Field) The present invention is a method of modifying crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof to produce waste paper, pulp, or organic material into pressure-modified polypropylene or crystalline polypropylene containing the modified polypropylene. A polypropylene sheet filled with a mixture of two or more types of fibers at a high concentration (hereinafter referred to as
It is called stone. ) and metal plates.

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.

(Prior art and problems) Some laminated composites using polypropylene resin as the core material have been put into practical use, but baking when painting molded parts requires treatment (usually at 180 to 200°C for 30 minutes). (heat treated), the resin of the stone melts and flows out from the punched part, blocking the punched part, causing problems in post-processing, and the resin of the stone shrinks significantly during the cooling and solidification process The area near the sheared part was deformed in %%,
There are drawbacks such as peeling of the interface between the core resin and the metal plate, and the fact is that baking cannot be used for parts that will undergo a painting process.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, we have developed a polypropylene system in which modified polypropylene is obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or its derivative, or a mixture of two or more types selected from waste paper, pulp, and organic fibers is blended with crystalline polypropylene containing modified polypropylene. Since the sheet is used as a core material, folding processing, punching processing,
It has adhesive strength that can withstand secondary processing such as cutting and deep drawing, and it also prevents molten resin from flowing out or dripping from cut or punched parts during the processing process, and prevents baking during painting.
Hereafter, it is called botatochi. ), 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 and no peeling between the resin and the metal plate.

(Means for solving the problem) Modified polypropylene obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof, or a mixture of two or more types of crystalline polypropylene containing modified polypropylene selected from waste paper, pulp, and organic fiber 15 ~50
A metal/polypropylene/metal laminated composite characterized by using a polypropylene sheet containing a weight factor as a core material.

The modified polypropylene used in the present invention is a crystalline polypropylene described below 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. In addition, 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 diethyl ester,
itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-
Examples include N,N-diethylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, and potassium acrylate. 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 crystalline polypropylene and an unsaturated carboxylic acid or its derivative at a temperature equal to or higher than the melting point of the crystalline polypropylene in the presence of an organic peroxide.

The amount of the unsaturated carboxylic acid or its derivative used is 0.01 to 5% based on the crystalline polypropylene that is the raw material resin.
The weight ratio is more preferably 0.05 to 3 weight ratio. Further, in the present invention, a mixture of unmodified crystalline polypropylene containing 5% by weight or more of the above-mentioned modified polypropylene can be used. Generally, it is preferable to use unsaturated carboxylic acid or a derivative thereof in an amount of 0.1 to 10 by mixing polypropylene with a weight coefficient of 0.1 to 10 and unmodified crystalline polypropylene in the above-mentioned ratio.

The crystalline polypropylene used in the modified polypropylene and the crystalline polypropylene mixed with the modified polypropylene include propylene homopolymers, propylene-ethylene block copolymers and random copolymers containing a propylene component of at least 70% by weight. Examples include a propylene/ethylene/butene-1 block copolymer and a random copolymer, a propylene/butene-1 random copolymer, and a mixture of two or more of these. The crystalline polypropylene resin for modified polypropylene and the crystalline polypropylene used by mixing with the modified polypropylene may be of the same type or may be of different types. Further, the melt flow rate is preferably in the range of o, i to 2 ON/10 minutes, more preferably in the range of 0.5 to 101/10 minutes. Furthermore, the modified polypropylene used in the present invention or the crystalline polypropylene containing the modified polypropylene may contain other polyolefins, side lights, ethylene propylene rubber, ethylene propylene diene rubber, poly4-methyl to the extent that the effects of the present invention are not impaired. A mixture of pentene, ethylene vinyl acetate copolymer, etc. can also be used.

The waste paper used in the present invention is not particularly limited as long as it is paper such as newspaper, cardboard, cardboard, end posts of cardboard, etc. In addition, waste paper is usually less than 30fl,
It is preferable to use one that has been cut or coarsely ground to a length and width of 5 fi or less.

The pulp used in the present invention is groundwood pulp (GP
), sulfite pulp (SP), soda pulp 7' (AP)
, kraft pulp (KP), semi-chemical pulp (SE
p), 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 limitations, such as polyamide fibers, polyimide fibers, polyester fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyacrylonitrile fibers, polyurethane fibers, polyalkylene paraoxybenzoate fibers, phenolic fibers, rayon. Examples include fibers, acetate fibers, cotton fibers, flax fibers, jute fibers, wool fibers, silk fibers, and the like.

The blending amount of the mixture of 2 m or more selected from the above-mentioned waste paper, pulp, and organic fiber is preferably in the range of 15 to 50% by weight, and particularly preferably 20 to 40% by weight. If the amount of the mixture of two or more selected from waste paper, pulp, and organic fiber exceeds 50% by weight, the fluidity of the resin during melting will decrease significantly, making molding difficult. This is undesirable because the adhesive strength of the laminated composite decreases when the weight is lower than 15%.If the weight ratio is less than 15%, the molten resin may flow out from the cut or punched parts during painting, and the molten resin may flow out during processing. This is not preferable because the interface between the resin of the material and the metal plate tends to peel off.

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 to 5 mm, preferably 0.2 to 2 mm. is desirable.

Further, the metal plates used in the present invention include metal plates of iron, steel, aluminum, 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
．． 05-2.0, preferably 0.15-1. Otm
It is. The nuclear metal plate is usually used after its adhesive surface has been subjected to a surface treatment such as degreasing or sandblasting.

- Furthermore, primer treatments such as epoxy resin coating and chromate treatment may be applied.

The laminated composite of the present invention is obtained by laminating metal plates whose adhesive surfaces have been surface-treated on both sides of the polypropylene sheet, and then
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., the pressure is preferably in the range of 1 to 50 Yu/cdG, 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 will not peel off even during secondary processing such as bending or deep drawing, and the core material resin will not run out or drop off from the cut surface of the cut or punched part during the coating process. There is no deformation due to heat, and there is hardly any 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.

Examples 1 to 3, Comparative Examples 1 to 5 1.3-bis(1
- 225% by weight of modified polypropylene modified with 1.2% by weight of maleic anhydride using 0.1% by weight of (butylperoxyisopropylene) benzene and 60% by weight of unmodified crystalline polypropylene homopolymer and ethylene propylene rubber. 15% by weight of waste paper and mechanical pulp (fiber summary 3
Organic fibers consisting of 65% by weight of polyester fibers and 355% by weight of cotton fibers with a thickness of 1 denier and a length of 3 mm) were placed in a Hensel mixer (trade name) in the proportions shown in Table 1, and stirred for 3 minutes. After mixing, the mixture was
The resin was extruded at a resin temperature of 190° C. using an extruder with a 5 mT die (vented) to form a sheet with a thickness of 0.4 wm.

In addition, as Comparative Examples 1 to 5, various fillers were blended with the polypropylene used in Examples 1 to 3 in the proportions shown in Table 1 below, and the mixture was stirred and extruded according to Examples 1 to 3. A sheet with a thickness of 0.4 ta was obtained.

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

The sheet was inserted between two steel plates and laminated by pressing at 200° C. for 1 minute at a pressure of 20 to 9/cIiG 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 JIS-6854. However, the tensile speed was 200 m/min.

In addition, for heat treatment, a test piece was prepared by cutting a 205 m diameter hole in the center of a laminated composite that was cut into 20 cyns lengthwise and 101 cm widthwise, and hanging the test piece in a heating oven maintained at 200°C for 30 minutes. carried out.

The laminated composite of the present invention, in which a mixture of two or more selected from waste paper, pulp, and organic fibers is blended in a specific ratio in the core material and core material shown in Table 1, has high peel strength and can be easily removed from the cut portion by heat treatment. No outflow of molten resin was observed, and there was no deformation of the cut portion.

Furthermore, no peeling phenomenon was observed between the metal plate and the core resin layer at the cut portion, and the laminated composite maintained its shape before the heat treatment.

Claims (1)

[Claims] (1) Modified polypropylene obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or its derivative, or crystalline polypropylene containing modified polypropylene, waste paper,
Mixture of two or more selected from pulp and organic fiber 15
A metal/polypropylene/metal laminated composite, characterized in that a polypropylene sheet containing ~50% by weight is used as a core material.