JPS6392447A - Manufacture of laminate of metal and polyolefine - Google Patents

Abstract

(57) [Abstract] 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 relates to a method for producing a laminate of a metal, particularly a steel plate and a polyolefin. Specifically, the present invention relates to a method for manufacturing a laminate of steel plate and polyolefin that has excellent adhesiveness and weather resistance.

[Prior art]

It is widely used for coating electrical wires, mechanical equipment, and protecting glass. Particularly, metal surfaces such as iron and aluminum are frequently coated, and various processing methods have been proposed.

However, due to the high crystallinity of polyethylene and polypropylene, adhesiveness is extremely poor, and this point has been the greatest difficulty in using polyolefins for metal coatings.

Various attempts have been made to improve this adhesiveness. For example, (1) A method of subjecting the adhesive surface of polyolefin to surface treatment such as solvent treatment, flame treatment, heated air treatment, or oxidation treatment.

(2) A method of mechanically roughening or surface oxidation treatment of the metal surface to be bonded; (3) A method of sequentially extrusion coating a metal with a modified polyolefin modified with an unsaturated carboxylic acid or anhydride and an unmodified polyolefin. How to stack more layers (Tokukosho≠
--io7t7)% (4) Apply a primer such as an epoxy resin adhesive to the metal, and coextrude a modified polyolefin modified with an unsaturated carboxylic acid or its anhydride and an unmodified polyolefin thereon at the same time. Method of laminating on extrusion laminate (JP-A-74-/4g!r62, etc.)
, etc. have been proposed.

[Problem that the invention seeks to solve]

However, both methods fl) and (2) involve complicated processing operations, and sufficient adhesive strength cannot be obtained.

In method (3) above, in order to obtain sufficient adhesion by coating the unmodified polyolefin on the modified polyolefin once solidified on the metal surface, it is necessary to extrude coat the unmodified polyolefin at approximately 300°C. The coating layer deteriorates due to high thermal history, and physical properties such as weather resistance and stress crack resistance deteriorate. In addition, in method (4) above, in order to obtain sufficient adhesion between each layer, it is necessary to melt and extrude the resin at about 30θ℃, and the unmodified polyolefin resin layer may deteriorate due to high heat history. , physical properties such as weather resistance and stress crack resistance deteriorate. moreover,
In methods (3) and (4) above, polyolefin resins other than low-density polyethylene as unmodified polyolefin resins tend to cause draw resonance and neck-in during extrusion lamination processing, and there is a limitation that only resins with high melt tension can be used. There is.

In order to solve the above problems, the present inventors have developed a method of preparing a coextruded multilayer film in which at least one surface is made of modified polyolefin and bonding the film to metal by thermocompression. has already reported that the above problems can be overcome (Tokugan Sho! Tar 2 Hiro 7.2?), but this method also prevents the metal-polyolefin laminate from undergoing secondary processing such as press working. When strain stress is applied to the polyolefin layer, the durability of the adhesive force, especially the hot water resistance, is not necessarily satisfactory.

[Means for solving problems]

As a result of various studies in order to solve the problems of conventional methods, the present inventors formed a composite by forming and laminating a modified polyolefin and an unmodified polyolefin in advance by coextrusion method under specific conditions. After forming
- It has been found that the adhesion of the laminate (adhesion between the resin layer and the metal) can be significantly improved by solidifying the composite and then laminating the composite onto a metal by thermocompression bonding, and has developed the present invention. It is completed.

That is, the gist of the present invention is to provide a method for producing a laminate consisting of a metal layer, a modified polyolefin layer, and an unmodified polyolefin layer, in which a modified polyolefin modified with an unsaturated carboxylic acid or its anhydride and an unmodified polyolefin are combined into the following ( 1) A composite is formed by film forming and lamination (by coextrusion method) under the conditions specified by formula (1) and formula (II), the composite is once solidified, and then the modified polyolefin layer surface of the composite is Method for developing a laminate of metal and polyolefin characterized by thermocompression bonding to metal Blow-up ratio = 7-6 (1
) cooling rate index τ=θ,! ~g・EUR+/θ
・・・・・・(■) exists.

The cooling rate index is a value defined by the following formula.

τ: Cooling rate index (seconds) EUR nibrow abutment ratio (1 for T-die molding) AG
: Air gap (distance between T-die and roll) or frost line height during inflation molding C,) ■, : Take-up speed (,/sec) vo: Linear velocity of molten resin exhibited by die (crII/sec) Exists.

The present invention will be explained in more detail below.

In the present invention, first, a modified polyolefin and an unmodified polyolefin are formed into a film and laminated by coextrusion under specific conditions to form a composite, and then solidified, and then the modified polyolefin layer surface of the composite is By thermocompression bonding to metal, a laminate with excellent adhesion between the υ metal and the polyolefin 4 film is manufactured.

The modified polyolefin used in the present invention is a polyolefin modified with an unsaturated carboxylic acid, its anhydride, or a derivative thereof. This modification is carried out according to known methods, usually by mixing and grafting these compounds onto the polyolefin, or by further converting the acid groups or acid anhydride groups of the modified polyolefin thus obtained into derivatives thereof. .

Polyolefins used in the production of such modified polyolefins include polyethylene, ethylene and α-olefins other than ethylene, tono copolymers such as vinyl acetate (meth)acrylic acid and its esters, polypropylene, and α-olefins other than propylene fluoropylene. Examples include copolymers with olefins.

The modified polyolefin resin referred to in the present invention refers to a single modified polyolefin obtained as described above or a blend of two or more kinds, or a blend of the polyolefin resin shown above and the modified polyolefin resin obtained as described above. .

The modified polyolefin used in the present invention is not particularly limited, but has a tart index of 0.2-10g/10
minute and the flow ratio is l! A range of 70 to 70 is desirable.

What is the melt index in the method of the present invention?
190 in accordance with 6760 (polyethylene test method)
°C, accredited, /1. The value is measured in kg. This value is 0.
2. ! If it is less than 9/10 minutes, the extrudability may be poor.
If it exceeds -10, the stability of the bubble decreases, which is not desirable.

The flow ratio is defined as the shear force of 10'dyne/cd (load///J/I) and IO''dyne/cd! using the above melt index measuring device. (load 173g) extrusion amount (
,! //10 minutes) is calculated as follows.

The fluidity ratio is a measure of the molecular weight distribution of the resin used; a lower fluidity ratio value /h means a narrower molecular weight distribution, and a larger fluidity ratio value means a broader molecular weight distribution. If the fluidity ratio is less than the above range, the bubbles become unstable, and if it exceeds the above range, thin wall molding becomes difficult, which is not desirable.

When the above-mentioned modified polyolefin is used in a laminate with metal as in the present invention, it is necessary to take certain appropriate It is preferable that the crystallinity is high, and specifically, the melting point is yo℃ or higher/λ! ℃ or less is preferable. The melting point of modified polyolefin resin is 2θ
Below 121°C, the resin itself lacks heat resistance, and above 121°C, it has high crystallinity, so even after the heating and quenching treatment described below, it is difficult to follow secondary processing and the metal under high temperature under strain stress after processing. - Adhesion between resins decreases. In addition, examples of unsaturated carboxylic acids or their anhydrides to be mixed or grafted to these polyolefins include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, and itaconic anhydride. Further examples of derivatives of unsaturated carboxylic acids and their anhydrides include esterification products of monoepoxy compounds and the above acids, and reaction products of acids and polymers having groups capable of reacting with these acids in the molecule. Examples include things. The method for causing the graft reaction with the raw material polyolefin described above may be a solution method or a slurry method, but economically it is preferably a melt-kneading method.

When using the melt-kneading method, an unsaturated carboxylic acid or its anhydride and a radical reaction initiator such as an organic peroxide or an azobis compound are added to the raw polyolefin powder or pellet in a predetermined mixing ratio in a Henschel mixer or the like according to a conventional method. The polyolefin powder is then sprayed onto a pellet and blended using a Henschel mixer or the like.

This blended polyolefin powder or pellet is put into a mixer 1, such as a Panbury mixer, a double screw mixer, etc. whose system is purged with nitrogen gas, and the temperature is 1.
．． By melt-kneading at 20 to 3θoC for 0.1 to 30 minutes, the highly modified polyolefin described above is obtained.

The amount of the unsaturated carboxylic acid or its anhydride grafted onto the modified polyolefin is 0.0.2 to 7% by weight, preferably 0.0.2 to 7% by weight, based on the raw material polyolefin. θ! ~0
．． 41 weight λ range.

0.11) If it is 4% by weight or more, sufficient adhesive strength cannot be obtained, and if it is 1% by weight or more, the hot water resistance and salt water resistance are rather poor. The amount of the initiator is θ relative to the polyolefin, 1 weight X or less, preferably O6θθ~0. It is in the range of 03% by weight. Examples of the organic peroxide used as the initiator include benzoyl peroxide and acetyl peroxide.

Di-t-butylpero-middle side, t-butylpero-middle dilaurate, dicumyl peroxide, α, α′-bis-t-butylperoxy-p-diinpropylbenzene, coverdimethyl-J, t-di-t-butylperoxy Nakasan, U, A-C t-7'thylperoxyhexyl, t-butylperoxybenzony), n-7'thyl-t, cubis-1-butylperocybarate, octanoyl peroxide, p-menthane Examples of azobis compounds include azobisinbutyronitrile, λ1.2'-azobis(,2,≠slag-trismethylvaleronitrile),
, 2. Examples include J'-azobis(-monocycloglovirprobionitrile).

It goes without saying that the modified polyolefin may further contain conventionally commonly used colorants, stabilizers, other additives, and fillers. As a filler, sand 1
Natural silica such as quartz, synthetic silica manufactured by wet or dry methods, natural silicates such as kaolin, mica, Merck, clay, and asbestos, synthetic silicates such as calcium silicate and aluminum silicate, and metal oxides such as alumina and titania. thing,
Calcium carbonate, calcium sulfate, and other metal powders such as aluminum and bronze can be used.

In the present invention, the unmodified polyolefin used to form a composite with the above-mentioned highly modified polyolefin includes low density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene- /1M41 bodies,
Polyolefins such as x-fv-vinyl acetate typical polymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester typical polymer, and ethylene-methacrylate copolymer are preferably used.

The above-mentioned unmodified polyolefin has a melt index of 0.2 to 101710 minutes and a fluidity ratio of /j to
A range of 70 is preferably included. If the melt index is less than the lower limit, the extrudability will be poor, and if it exceeds the upper limit, the stability of the bubble will decrease, which is not desirable.

Further, if the flow rate ratio is less than the lower limit, the bubble becomes unstable, and if it exceeds the upper limit, it becomes difficult to form a thin wall, which is not desirable.

The unmodified polyolefin may optionally contain additives commonly used in polyolefins, such as pigments, heat stabilizers, weathering agents, and ultraviolet absorbers, if necessary.

In the present invention, the method for producing a composite by laminating modified polyolefin and unmodified polyolefin is as follows:
A method is adopted in which both resins are coextruded by an inflation method or a T-die method, and then melted and bonded inside or outside the die to form a composite. When using a lamination method other than the above-mentioned coextrusion method, the interlayer adhesive strength between the unmodified polyolefin layer and the modified polyolefin layer is insufficient, so it is necessary to raise the resin temperature. In this case, the unmodified polyolefin layer undergoes a high thermal history and the resin deteriorates. Therefore, in order to minimize the thermal history imparted to the unmodified polyolefin layer and to improve the interlayer adhesive strength between the unmodified polyolefin layer and the modified polyolefin layer, the method of the present invention uses a coextrusion method under specific conditions. A composite is produced by molding and laminating. As the molding conditions by the coextrusion method, the conditions shown by the following formula (1) and (button formula) are adopted.

Blow-up ratio=/-4...(1) Cooling rate index τ=θ, j-4・EUR+/θ...
(It) Here, BUR indicates the blow-up ratio, and EUR in the case of T-die molding is expressed as 7.

Further, τ indicates a cooling rate index, which indicates the residence time (seconds) from when the molten resin is extruded from the die until it reaches the frost line, and is expressed by the following equation (4).

t: Cooling rate index (seconds) 80: Air gap (distance between T-die and roll) or 70-line height ω during inflation molding
) vl: Take-up speed (cm/sec) vo: Linear velocity of molten resin at the die exit (1/sec) If the blow-up ratio is less than the above lower limit, the residual stress in the film will not be high, and will remain high even after it is bonded to metal. Less strain stress remains and the adhesion between the resin layer and the metal decreases.

Moreover, if it exceeds the above upper limit, molding stability will decrease, which is not preferable.

The cooling rate index (τ) can be controlled to a predetermined value by changing each element in the above formula (it), for example, by changing the frost line height (FLH), or by changing the frost line height (FLH). In order to increase the cooling rate to 11, it may be controlled by changing the extrusion rate of the extrusion and the take-up speed of the take-off device, and a predetermined cooling rate index (τ) is set by combining these factors.

If the cooling rate index (τ) is less than the above-mentioned lower limit, the moldability becomes extremely difficult, and if it exceeds the above-mentioned upper limit, the adhesion will deteriorate as in the case where the blow-up ratio is less than 1, which is not preferable.

The molding temperature in the above coextrusion method may vary depending on the type of modified polyolefin or unmodified polyolefin used for molding, but is usually higher than the melting point of the polyolefin to 26
The temperature is preferably θ°C or lower, especially /60°C to 230°C.

However, the thickness of the composite film is usually jO~300μ
and the thickness of the modified polyolefin film layer! It is desirable that the thickness is in the range of μ or more and 1 or less, which is the thickness of the composite film.

When the thickness of the composite film is less than jOμ, its performance as a holding layer for metal is poor, and it is not suitable for embossing or the like in a subsequent process.

200μ or more, press processing of laminate with metal, etc.
Next processing becomes difficult.

If the thickness of the modified polyolefin layer is 1β or more than the thickness of the composite film, the performance of the unmodified polyolefin layer as a coating layer will not be sufficiently exhibited, and if it is less than jμ, the adhesion to the metal surface will be insufficient.

In the present invention, it is sufficient that the surface of the metal used for thermocompression bonding with the composite film is clean, but when the laminate is used as an industrial material, aluminum or iron is preferably used as the metal. In the case of aluminum, the surface is degreased and treated with FCB, and in the case of iron, chemical conversion treatments such as plasting, phosphate treatment, and chromate treatment are applied to increase the adhesive strength's water resistance, salt water resistance, and hot water resistance. It is even more effective because it can be measured.

In the present invention, when bonding the above-mentioned composite to the surface of such a metal, an organic adhesive such as an epoxy resin or a polyurethane resin is interposed between the metal and the above-mentioned composite for thermocompression bonding). Adhesion, especially the hot water resistance of the adhesion,
This is desirable because it can increase salt water resistance, and it is even more effective to use it in combination with a pigment that has antirust ability.

In addition, chromic acid is added to the epoxy resin adhesive according to
When one or more selected from group metal salts such as zinc chromate and strontium chromate are added, it is more effective for improving the hot water resistance and salt water resistance of the adhesive strength.

In this case, the total amount of one or more of the chromates is aO parts or less based on 100 parts of the epoxy resin, and the amount applied is 3 to λog with respect to the coated surface/d. It is desirable that the amount is within this range and that it is gelled after application. Epoxy resin adhesives have various functional groups)
Various known materials used for fusing polyolefins or polyolefin compositions containing various polymers and the like to metals can be used.

For example, it contains so-called epoxy resin curing agents such as amines, polyamides, acid anhydrides, aninol resins, butylated urea formaldehyde resins, etc. with a molecular weight of 300 to 0.
000 types of thermosetting epoxy resins can be used. The epoxy resin used for this is generally a bisphenol A-based epoxy resin, but other known epoxy resins may be used. Furthermore, as an adhesive, an epoxy resin with a molecular weight of ♂θO to 4t00θ is used as an adhesive.
-s and 70 parts by weight and 70 parts by weight of fatty acids having a carbon number of 10 to λθ
It is also possible to use a so-called epoxy ester, which is a reaction product, in an amount of 30 to 30 parts by weight, or a curing agent such as a butylated melamine formaldehyde resin in an amount of up to 30% by weight.

When such a thermosetting epoxy resin adhesive is used, the epoxy resin adhesive is used in an uncured state or in the process of gelling.

Usually, it is used in a state where it is in the process of gelling, that is, it is gelling but not completely gelling.

Regardless of whether the epoxy resin adhesive is used in an uncured state or in the process of gelling, the thermocompression bonding of the modified polyolefin layer is carried out under conditions such that the thermosetting epoxy resin adhesive is completely cured. Good adhesive strength and salt water resistance cannot be obtained unless curing is completed.

Also in the present invention. Molecular weight without curing agent added/0.
000 or higher thermoplastic epoxy resin adhesives may also be used. In this case, it is not preferable to use a material with a low molecular weight because the adhesive strength will be poor.

It can also be applied. In that case, the coating may be carried out at a temperature of the metal surface or modified polyolefin layer, which is the surface to be coated, at room temperature or higher.

However, if a solvent is used, post-treatment of the solvent is required, so it is preferable to use an epoxy resin adhesive that is liquid at room temperature.

The film thickness of the epoxy resin adhesive is 1 to JθOμ, preferably! ~! It can be applied to the metal surface using a spray, bar coater, roll coater, etc., for example. The modified polyolefin layer is thermocompression bonded onto the epoxy resin adhesive.

In the present invention, the method for thermocompression bonding the composite film and the metal is a method of thermocompression bonding the modified polyolefin side of the composite film to the metal surface, for example, after applying the above adhesive on the metal plate and curing it. Alternatively, without coating, the modified polyolefin side of the composite film is used as the adhesive surface, and the adhesive is hot pressed at a temperature above the melting point of the modified polyolefin and below 230°C, or the above adhesive is coated on the surface in advance and cured. After or without coating, the modified polyolefin side of the composite film and the metal surface are brought into close contact, and the
A method of preheating to 30° C. or lower and then pressing using a pressing roll is mentioned. The crimping time during hot pressing and the preheating time before roll crimping vary depending on the physical properties of the modified polyolefin, but are generally 0. ! Minutes! minutes is enough. The pressure during heat press and roll crimping is not particularly limited, but 1
Usually 0.0/kg/crl gauge or more, preferably 0.0. ! rkg/aI! gauge~! θkg/C1l
Selected from a range of degrees.

That is, in the present invention, the modified polyolefin side of the composite film and the metal are laminated.

The temperature on the modified polyolefin side is set to above its melting point, 230°C.
It is necessary to heat to below ℃. At this time, if the temperature on the modified polyolefin side is below the melting point, the adhesion will not be good;
Further, temperatures above 230° C. are not suitable because the unmodified polyolefin side undergoes excessive heat history and undergoes oxidative deterioration, resulting in a significant decrease in weather resistance and stress crack resistance.

In addition, when producing a laminate by coextrusion laminating a metal with a modified polyolefin layer and an unmodified polyolefin layer, the metal and the modified polyolefin layer are laminated at a temperature above the melting point of the modified polyolefin and below 230°C. However, sufficient adhesion cannot be obtained. Furthermore, in order to obtain sufficient adhesive strength with the above-mentioned coextrusion lamination method, it is necessary to laminate at a temperature of around 3oθ℃, and in this case, the unmodified polyolefin layer undergoes a high thermal history and becomes oxidized. The weather resistance and stress crack resistance are significantly reduced.

In the present invention, the adhesion between metal and polyolefin can be further improved by subsequently subjecting the laminate obtained as described above to heat treatment and rapid cooling treatment. The heat treatment is carried out at a temperature of the laminate itself that is from the melting point of the modified polyolefin to 3θO<0>C.

If the heat treatment temperature is lower than the melting point of the modified polyolefin, the adhesion of the laminate will not be sufficiently improved, and if it exceeds 300°C, the resin layer of the laminate will undergo thermal deterioration or discoloration, which is not preferable.

The time required for the heat treatment is determined by the heat treatment temperature, the thickness of the coating resin layer, the thickness of the metal, the crystallization state of the resin layer before treatment, etc., but is generally at least 7 seconds. Preferably it is io seconds or more. If the treatment time is too long, problems such as deterioration and coloring of the resin layer may occur.

Processing time is less than io minutes, preferably! It should be kept under preparative analysis.

The melting point of the modified polyolefin resin referred to in the present invention is determined from the endothermic peak by differential thermal analysis. When the resin consists of a mixture of 21M or more,
When there are many endothermic peaks, the endothermic peak resulting from the main component is taken as the melting point of the resin.

After the above heat treatment, the method of rapidly cooling the laminate as described above is as follows:
A method of cooling by immersing in a refrigerant such as water or mineral oil maintained at a temperature lower than 0°C, preferably 30°C or lower, a method of cooling by spraying the refrigerant, and a metal roll maintained at the temperature. A method of cooling by sufficient contact or a method of cooling by forcibly blowing sufficiently cooled air onto the laminate can be adopted, but a method of cooling using water is particularly preferable due to its effectiveness and workability. It is.

At this time, in order to obtain a sufficient quenching effect, it is desirable to reach the temperature at which the laminate is heated from the temperature at which the laminate is cooled within to seconds, preferably within 30 seconds, and more preferably within 10 seconds. Mashibo [Example] The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to the following examples as long as the gist is not exceeded, and in the following examples, the melting point of the resin used was measured and the adhesion performance of the obtained laminate was evaluated. was carried out using the following method.

(1) Measurement of melting point of resin In differential thermal analysis, a sample of 10~±l■ was heated and melted at 200°C, then cooled and solidified at 10°C/- to 70°C, and then heated and melted at an angle of /0'C/=. The main peak position on the chart was taken as the melting point.

(2) Evaluation of adhesion JIS-67! ! The Erichsen test was conducted in accordance with K.K, and the following ranking was used for levitation with a chair-type notch.

Pulling evaluation Appearance evaluation (Pull the notch part with tweezers) Rank A No abnormality Rank J Abnormality B Slightly floating Hiro Slightly peeling 0 Obviously floating 3 Obvious K Peeling D Significantly floating 7 Significantly peeling source Completely peeling l Complete Initial adhesion was evaluated by ranking it as peeling or higher.

In addition, the thus obtained test piece was immersed in boiling water for 1 hour, and the levitation of the tiger's notch (9) was evaluated using the above-mentioned ranking to determine the hot water resistance.

The adhesion of the sample will be shown by a combination of appearance evaluation and tensile strength evaluation.

For example, it is indicated by A-g, ○-1, etc.

Example 1 High-pressure low-density polyethylene (density: o, Octopus 6Ji
/cll, melt index (hereinafter abbreviated as y-ko)
Modified high-pressure polyethylene graft-modified with maleic anhydride (density: Olli/i/cdl, M engineering: 2-Ojl//
0 minutes, maleic anhydride content: ixoθppm, melting point: 10°C) and resin temperature i9<t°C.

Blowup ratio 2.0. A composite film of the low-density polyethylene layer of 20 μm and the modified high-pressure polyethylene layer of 30 μm was produced by coextrusion in a die using an inflation method under conditions of a cooling rate index of 10. Next, using the modified polyethylene layer of the composite film as an adhesive surface, this was applied onto a zinc phosphate treated steel plate which had been coated with a ratio of chromic acid to 10 θ parts of thermosetting epoxy resin and had been heat treated to 260″CK. Torr pressure bonding was performed at a roll pressure of p kg/crl to obtain a laminate.

The initial adhesion of the thus obtained laminate was ranked O.6. Place this laminate in an oven at a predetermined temperature so that the board temperature reaches 77θ℃! Heat for 2 seconds and immediately turn 47/
The adhesion of the laminate obtained by immersing it in a water bath of ``C'' and rapidly cooling it was evaluated, and the results are shown in Table 1.

Examples - l In Example 1, the same procedure as in Example 1 was carried out except that the coextrusion conditions (blow-up ratio or cooling rate index) were changed as shown in Table 1.

The results are shown in Table 1.

Comparative Examples 1 to 3 The same procedures as in Example 1 were conducted except that the coextrusion conditions (blow-up ratio or cooling rate index) were changed as shown in Table 7.

The results are shown in Table 7.

Table l [Effects of the Invention] According to the method of the present invention, a laminate of metal and polyolefin with excellent adhesive strength, weather resistance, etc. can be obtained, and! ! It is also very practical in terms of ease of operation during production.

−Itto Seven One One One

Claims (1)

[Claims] (1) In a method for producing a laminate consisting of a metal layer, a modified polyolefin layer, and an unmodified polyolefin layer, a modified polyolefin modified with an unsaturated carboxylic acid or its anhydride and an unmodified polyolefin are prepared as follows (I
Forming and laminating films by coextrusion under the conditions shown by formulas ) and (II) to form a composite, solidifying the composite once, and then thermocompressing the modified polyolefin layer surface of the composite to metal. A method for manufacturing a laminate of metal and polyolefin characterized by: Blow-up ratio = 1 to 6 (I) Cooling rate index τ = 0.5 to 4 BUR + 10
・(II)