JPS63242536A - Metal-polypropylene-metal laminated composite body - 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 metal/resin laminated composite in which a polypropylene sheet is sandwiched between metal plates and pressure bonded.

More specifically, modified polypropylene obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or its derivative, or polypropylene fibers and organic materials obtained from crystalline polypropylene containing the modified polypropylene! &! The present invention relates to a laminated composite comprising a metal plate and a polypropylene sheet (hereinafter referred to as core material) obtained by heating and compressing a nonwoven fabric formed by irregularly intertwining conductive fibers and conductive fibers.

(Prior art) In recent years, from the viewpoint of reducing the weight of metal plates and imparting sound absorption, vibration damping, and heat insulation properties to metal plates, a U-shaped laminated composite has been developed in which plastic sheets are sandwiched between metal plates. Widely used in the civil engineering, architecture, automobile, and home appliance fields.

Conventionally, thermoplastic resins such as poly-1-dylene, polypropylene, and NOC-6 have been used as plastic sheets used as core materials.

Furthermore, in order to impart conductivity to the core material and enable welding as a composite, metal powder, carbon black, metal-plated resin powder, etc. are mixed into the resin of the core material.

[Problem that the invention aims to solve]

A composite material having a polypropylene sheet as a core material is required to have an adhesive strength of λ1 to withstand secondary processing such as bending, punching, cutting, and deep drawing.

In conventional laminated composites using boria[1-pyrene resin as the core material, punching is performed during the baking process (usually heat treated at 180 to 200°C for 30 minutes) when painting the molded parts. The resin of the core material may melt and flow out from the processed area, or the molten resin may fall directly below (hereinafter referred to as "bottom drop"), blocking the punched area, causing problems in post-processing, or causing the molten resin to cool down. Due to the large shrinkage during the solidification process, there are disadvantages such as deformation especially near the sheared part and peeling of the interface between the core resin and metal. There was a problem that it could not be used for parts with 1.

Furthermore, since polypropylene resin is an insulator, it also has the problem that electric welding such as spot welding and seam welding cannot be performed.

In order to make the resin conductive in order to make welding possible, there is a method of kneading metal powder into the resin, but it is difficult to mix uniformly and the extruder screw wears out! Historically, there has been a problem in the amount of equipment used, and if the metal plates are not filled to a large capacity, the electrical connection between the metal plates tends to be incomplete, and weldability is not always perfect.

Therefore, the object of the present invention is to have a high adhesive strength that is essential for secondary processing, and to prevent burning and adhesion during painting! A metal that has heat resistance that does not cause molten resin to flow or drop during the process, does not cause thermal deformation near the cutting part, and does not cause peeling between the core resin and the metal plate, and can be electrically resistance welded. - To provide a polypropylene/metal laminated composite.

[Means for solving problems]

As a result of intensive studies to solve the above-mentioned problems, the present inventors created a nonwoven fabric using specific modified propylene-based mM, Ij organic fibers, and conductive i&Im, and used a sheet made by heat-pressing the nonwoven fabric as a core material. The present invention was completed based on the discovery that the problems could be solved by using the method as a method.

In short, the present invention relates to a polypropylene fiber obtained from a modified polypropylene obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof, or a crystalline polypropylene obtained by mixing the modified polypropylene, and an organic material! The core material is a polypropylene sheet obtained by heating and compressing a nonwoven fabric formed by irregularly intertwining li[] and conductive fibers at a temperature higher than the melting point of boria[]pyrene fibers. Metal/boria [1 pyrene/metal V
It is a four-layer composite.

The amount of organic fibers and conductive fibers blended into the nonwoven fabric is preferably 15% to 50% of the total, and the blend of conductive fibers is 5 times! It is preferable that it is at least u%.

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 the unsaturated carboxylic acids used in the production of the modified polypropylene include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itanoic acid, and silica laconic acid. Further, derivatives of unsaturated carboxylic acids include acid anhydrides, Nisdel, amides, imides, metal salts, etc., such as maleic anhydride, cytocucopentaic acid anhydride, itaconic anhydride, mebble acrylate, methyl methacrylate/acrylic. @1 chill, 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 monoamide, maleic diamide, maleic M-N-monoethylamide, maleic M-N.

N-diethylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, storium acrylate,
Examples include sodium methacrylate and potassium acrylate. It is preferable to use these non-fomaleic acids.

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 in warm water having a melting point higher than the melting point of the crystalline polypropylene in the presence of an organic peroxide.

The amount of the unsaturated carbon fab or its derivative used is TO, '01 with respect to the crystalline polypropylene that is the raw material resin.
~5f! ffi%, more preferably $;to, 05 to 3% by weight. Further, in the present invention, it is possible to use a mixture of unmodified crystalline polypropylene so as to contain the above-mentioned modified polypropylene in an amount of 5% by weight or more.

Generally, it is preferable to mix modified polypropylene containing 0.1 to 10% by weight of unsaturated carboxylic acid or its derivative with unmodified crystalline polypropylene so that the ratio is 91 as described above. .

The crystalline polypropylene used in the modified polypropylene and the crystalline polypropylene mixed with the modified polypropylene include propylene homopolymers and polypropylenes.
Propylene/ethylene block copolymer or random copolymer containing at least 70% by weight of pyrene component, propylene/ethylene/butene-1 block copolymer-like random copolymer, propylene/butene-1
Examples include random copolymers and mixtures of two or more thereof.

The crystalline polypropylene for the modified polypropylene and the crystalline polypropylene used in conjunction with the modified polypropylene may be of the same type or may be of different types.

Also, the melt flow rate is 0.1 to 20! ? /10 minutes is preferable, more preferably 0.5 to 10 g/l
It's 0 minutes.

The modified polypropylene used in the present invention or the crystalline polypropylene mixed with the modified polypropylene may contain other polyolefins, such as ethylene propylene rubber, ethylene propylene rubber, etc., to the extent that the effects of the present invention are not impaired.
It is also possible to use a mixture of diene rubber, poly-4-methylbentene, ethylene-vinyl acetate copolymer, and the like.

Since a polypropylene sheet made of a non-woven fabric prepared by mixing a modified resin obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof is used as the core material, the adhesion between the core material and metal can be improved.

The modified polypropylene or the crystalline polypropylene containing the modified polypropylene may contain heat-resistant stabilizers, weather-resistant stabilizers, lubricants, slip agents,
Flame retardants, antistatic agents, nucleating agents, inorganic fillers, metal powders, etc. may be used in combination.

The organic U and navy blue used in the present invention are those that do not decompose or melt under the temperature conditions during melt-compression or molding of the nonwoven fabric formed from the TL fibers and polypropylene fibers. There are no particular restrictions on
For example, polyamide fiber, polyimide 11 miscellaneous, polynismil fiber, polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyacrylic LL nitrile la navy blue, polyurethane fiber, phenol fiber, rayon fiber, acetate fiber, cotton. fiber, flax fiber, jute fiber,
Examples include wool fibers, silk fibers, and mixtures of two or more thereof.

Examples of g-electric fibers used in the present invention include metal fiber carbon fibers, metal-coated carbon fibers, metal-coated organic fibers, and metal-coated glass! Examples include l fibers, metal-coated organic fibers, and the like.

The nonwoven fabric used in the present invention can be obtained by a binder method, a needle bundling method, a hydraulic entanglement method using spunbonding, a thermal bonding method, a wet papermaking method, or the like.

The total amount of the nonwoven fabric used in the present invention, including the 81-quality fibers and the conductive fibers, is preferably in the range of 15 to 50% by weight, particularly preferably 20 to 40% by weight.

If the total amount of organic fibers and conductive fibers exceeds 50% by weight, it is undesirable because the adhesive strength of the laminated composite will decrease, and if it is less than 15% by weight, it will cause burning during painting and damage to the cut parts and nails during processing. This is not preferable because the molten resin can be seen flowing out from the handling area, and the interface between the resin and the metal plate is likely to peel off.

The amount of the conductive fiber compound must be at least 5% by weight, and if it is less than 5% by weight, electric resistance welding cannot be performed.

The polypropylene sheet used as the core material of the present invention is made by heating and compressing the nonwoven fabric described above using a device such as a super calender at a temperature above the melting point of the polypropylene fiber and at a temperature at which the laminated mtIi does not decompose or melt. The thickness is preferably within the range of 0.03 to 1.0M, preferably 0.05 to 0.3sw.

The metal plates used in the present invention include metal plates made of iron, steel, aluminum, copper, zinc, tin, nickel, titanium, etc., and metal plates made of alloys containing one or more of these metals as main components. I can do it.

The thickness of the metal plate is 0.05 to 2.0, preferably 0.05 to 2.0.
It is 15 to 1.0 sw.

j The metal plate is usually used after its adhesive surface has been subjected to a surface treatment such as degreasing or sandblasting. Furthermore, a surface treatment such as a brimer treatment such as an epoxy resin coating or a phosphorus mate treatment may be performed.

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 preferably 160 to 220°C, and the pressurizing pressure is preferably within the range of 1 to 50 KI/ciG. It is desirable to do so.

(Function) Since polypropylene does not have a polar group, the adhesive strength after pressure bonding to a metal plate is weak even if various surface treatments are applied to the surface of the metal plate. Since it has been modified with its derivatives, polar groups have been introduced, and when it is made into a composite, it has adhesive strength that can withstand various secondary processes.

A nonwoven fabric was made from modified polypropylene fibers, organic fibers, and conductive mN, and the sheet was heated and compressed at a temperature higher than the melting point of the polypropylene fibers, and then pressed against a metal plate using the sheet as a core material, resulting in organic tanh conductivity! It becomes a reinforced resin core material due to the network structure of the polypropylene fibers, and when it is baked as a composite, the molten polypropylene is incorporated into the network fibers, and there is no run-out or drop-off from the processing area. There was no thermal deformation near the cutting tilsPI, no peeling between the core resin and the metal plate, and the heat resistance was good.

Metal powders etc. that are normally used to impart conductivity are
During kneading, it tends to aggregate and it is difficult to mix uniformly.

Furthermore, if the particle size is too small compared to the thickness of the core material, electrical conductivity cannot be obtained, and if it is too large, the adhesive strength decreases, making it difficult to select the particle size range. In the present invention, the conductive layer is uniformly distributed during the formation of the nonwoven fabric, and since it is a fiber, it can be flexibly applied during the heating and compression forming of the core material, and the conductivity between the upper and lower metal plates can be ensured. It has good weldability.

〔Example〕

The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the same extent by the Examples.

(Examples 1 to 5, Comparative Examples 1 to 3) Using a propylene/ethylene random copolymer with an ethylene content of 3.5% by weight as a radical initiator, 0.10% by weight of 1゜3(t-butylperAxisopropyl)benpine 25% by weight of female polypropylene modified with 1.2Φm% of anhydrous maleic M, 60% by weight of unmodified propylene-ethylene block copolymer (ethylene content: 8.5% by weight) and 15% by weight of ethylene-propylene rubber. Polypropylene consisting of was processed into 11 reports. , a nonwoven fabric with a fabric weight of 200 g/Td made from a fiber mixture of the fiber, bouylon fiber (fiber length 50 m), and stainless steel fiber @ (fiber length 5 m) in the proportions shown in Table 1 was supercalendered. It was processed into a sheet form at a linear pressure of 50 pi/cms and a temperature of 190°C using a combination of infrared heating and infrared heating.

As a comparative example, Comparative Example 1 was prepared by adding 10% by weight of stainless steel fibers to the modified polypropylene fibers instead of adding nylon fibers to the modified polypropylene fibers.

Further, Comparative Example 2 was prepared in the same manner as in sheet form without adding nylon IIM or stainless steel fiber.

Comparative Example 3 was prepared in which 30% by weight of only the nylon m group was blended, and the sheet was made into a sheet like 1181 without blending the swanless steel fiber.

Next, the surface was cleaned with triclean as a metal plate to a thickness of 0.2
A 75 m cold rolled steel plate was prepared.

The sheet was inserted between two steel plates and crimped at 180 °C for 1 minute at a pressure of 20 KB/cm G.
1i'4 complex was obtained.

In Comparative Example 4 in which unmodified polypropylene was used as polypropylene mH, there was no adhesive strength and a laminated composite could not be obtained.

The T-peel strength, electrical resistance in the thickness direction, and state after heat treatment of the laminated composite were evaluated and observed, and the results are shown in Table 1. In addition, the measurement of T-type peel strength was carried out using J Is-685.
It was carried out according to 4. However, the tensile speed was 200 m/min. The electrical resistance in the thickness direction was measured using a computing digital multimeter TR687 using a rod-shaped electrode with a diameter of 4 m.
7 (manufactured by Takeda Riken).

The heat treatment was carried out by using a test piece that had a hole of diameter 20ag+ in the center of the laminated composite that was cut into 101 pieces horizontally for $1201, and suspending the test piece in a heating oven maintained at 200°C for 30 minutes. .

As shown in Table 1, the laminated composite of the present invention using a sheet obtained from a nonwoven fabric containing organic fibers and S-conductive fibers in a specific ratio as a core material has high peel strength, and No molten resin was observed flowing out from the cut portion, and there was no deformation of the cut portion. There was no peeling phenomenon between the metal plate and the resin layer at the cut portion, and the V4 layer composite maintained its shape before the heat treatment. Additionally, the laminated composites of the present invention exhibit low resistance values that allow electrical resistance welding.

In Comparative Example 1, in which only 10% by weight of stainless steel fibers were blended without blending nylon fibers, some flow of resin after heat treatment, deformation of cut parts, and peeling were observed. In Comparative Example 2, in which neither bouylon fibers nor stainless steel fibers were mixed, the electrical resistance in the thickness direction was greater than 1012 Ω, making it impossible to weld, and resin flowing out after heat treatment, deformation of cut parts, and peeling were observed.

In Comparative Example 3, in which only Vylon mu was blended and no stainless steel fibers were blended, the electrical resistance in the thickness direction was 1012 ΩJ-, and welding was impossible.

〔Effect of the invention〕

The laminated small aggregate obtained by the present invention is cut and punched at T1
It will not peel off even during secondary processing such as bending or deep drawing, and the burning during painting will not occur due to the flow of the resin of the core material from the glued surface of the B1 cut part or the punched part during processing, and the drop-off of the core material. 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. Additionally, electric resistance welding, which was previously impossible, became possible.

In particular, since the laminated composite of the present invention uses a nonwoven fabric heated and compressed into a sheet as the core material, it is possible to reduce the thickness of the core material to 100μ or less, and the laminated composite using such a thin core material The body is especially suitable for use as a damping plate.

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 panels for construction.

Claims (1)

[Claims] 1. A polypropylene fiber obtained from a modified polypropylene obtained by modifying crystalline polypropylene with an unsaturated carboxylic acid or a derivative thereof, or a crystalline polypropylene mixed with the modified polypropylene, an organic fiber, and a conductive fiber. A metal/polypropylene/metal laminated composite material characterized in that the core material is a polypropylene sheet obtained by heating and compressing irregularly intertwined nonwoven fabric at a temperature higher than the melting point of polypropylene fibers. 2. Claim 1, wherein the total amount of organic fibers and conductive fibers blended into the nonwoven fabric is 15 to 50% by weight of the total, and the content of the conductive fibers is 5% by weight or more. The metal/polypropylene/metal laminate composite described above.