JPH0631881A - Laminate - Google Patents

Abstract

PURPOSE:To provide a synthetic resin laminate having excellent adhesiveness to a metal base material and hard to generate delamination even in secondary processing large in degree of deformation by utilizing the excellent surface gloss, surface hardness, design effect, humidity resistance and corrosion resistance possessed by a polyester film. CONSTITUTION:In a laminate consisting of a polyester film and a polyolefinic resin layer, adhesive layers with a thickness of 0.5-25mum composed of modified polyolefin modified with unsaturated carboxylic acid or an anhydride thereof or a polyolefinic resin compsn. containing modified polyolefin are provided on both surfaces of the polyolefinic resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated body, and more specifically, to a synthetic resin laminated body suitable for laminating a metal substrate such as a coated steel sheet and a synthetic resin using the synthetic resin laminated body. The present invention relates to a laminate with a metal base material.

[0002]

2. Description of the Related Art Conventionally, a laminated body obtained by coating a metal plate with a polyester film has been used in the field of home electric appliances and the like. Since the polyester film has a small adhesive force to a metal, it is usually necessary to improve the adhesiveness by a special surface treatment, application of an adhesive or a primer, or blending of a hot-melt type resin. However, even with the above method, the adhesiveness (adhesive strength) between the polyester film and the metal plate is not sufficient.

The coated steel sheet has been widely used as an industrial material in various fields due to its excellent workability and designability, and the surface gloss of the coated surface is improved in order to further enhance the designability. The demand is increasing. As one of the methods, clear coating is further applied on the coated surface of the coated steel sheet, but although such a method can give an apparent surface gloss, it lacks the "depth" of the gloss and has a mirror-like finish. It is not possible to bring out the design. Further, if the clear coat layer is made thicker to give a greater depth, the surface hardness will be lowered and it will be easily scratched, and there will be problems such as cracks on the coated surface when secondary processing such as bending is performed.

Therefore, a method of coating a coated steel sheet with a transparent high molecular weight plastic film, particularly a method of coating a biaxially stretched polyester film (typically a polyethylene terephthalate film) having excellent surface gloss and surface hardness is known. Proposed. However, also in the above case, the adhesiveness (adhesive force) between the polyester film and the metal plate becomes a problem.

As one of the methods for improving the adhesiveness between a polyester film and a metal, a thermal bonding method using the following adhesive has been proposed. (1) A method using an ionomer resin or an ethylene-methacrylic acid copolymer resin (JP-A-62-22052).
7 publication). (2) A method of using a composition comprising an ethylene-vinyl acetate copolymer and a modified polyolefin resin (JP-A-59-59)
67048). (3) A method of using a composition in which polyester is blended with an ionomer or a modified polyolefin resin.

However, in the above methods (1) and (2), since the resin used for the adhesive layer has low thermal stability, so-called fish eyes are likely to be generated at the film forming stage, and in a remarkable case. , The gel discolors dark brown and the appearance is remarkably deteriorated. Further, since the resin used for the adhesive layer has a low melting point, there is a problem that the adhesive force between the coating layer and the metal base material is lowered when heat is applied to the laminated body in the secondary processing of the laminated body.

On the other hand, in the method (3), although there is no problem that the adhesive strength is lowered during the secondary processing, when the composition of the adhesive layer is formed into a film, it is usually 200 ° C. or higher depending on the melting point of the polyester. Therefore, there is a problem that the modified polyolefin is thermally deteriorated by the ionomer contained in the composition to generate fish eyes and remarkably deteriorate the appearance.

[0008] The applicant has previously made a synthetic resin laminate (polyester film / polyolefin resin layer) suitable for laminating a metal substrate, and a synthetic resin using the synthetic resin laminate and a metal substrate. A proposal was made for a laminate (polyester film / polyolefin resin layer / metal substrate) (JP-A-2-36943 and JP-A-1-).
317756).

[0009]

In each of the above-mentioned laminates, a polyolefin resin layer serving as a metal base material is provided with a specific modified polyolefin adhesive layer, and the adhesive layer provides excellent adhesion. And secondary workability.
However, as a result of subsequent studies, when the secondary processing is performed on the laminated body of the synthetic resin film and the metal base material, if the degree of deformation is large, it is said that the polyester film and the polyolefin resin layer are easily delaminated. It turned out to be a problem.

The present invention has been made in view of the above circumstances, and an object thereof is to utilize the excellent surface gloss, surface hardness, designability, moisture resistance, corrosion resistance, etc. of a polyester film, and a metal base. Of a synthetic resin having excellent adhesiveness to a material and being resistant to interlayer delamination even in secondary processing with a large degree of deformation, and a laminate of a synthetic resin and a metal substrate using the synthetic resin laminate To provide.

[0011]

That is, the first aspect of the present invention
The gist of is a laminate comprising a polyester film and a polyolefin-based resin layer, wherein both sides of the polyolefin-based resin layer contain a modified polyolefin modified with an unsaturated carboxylic acid or an anhydride thereof or the modified polyolefin. A second aspect of the present invention resides in a laminated body characterized by being provided with an adhesive layer having a thickness of 0.5 to 25 μm made of a polyolefin-based resin composition, and the second gist is a polyester film, a polyolefin-based resin layer, and a metal substrate. And a polyolefin resin composition modified by unsaturated carboxylic acid or an anhydride thereof on both sides of the polyolefin resin layer. The laminated body is characterized in that an adhesive layer having a thickness of 25 μm is provided.

The present invention will be described in detail below. In the present invention, the raw material of the polyester film is not particularly limited, and polyethylene terephthalate (hereinafter, referred to as “PE
Abbreviated as "T"), polybutylene terephthalate, polyethylene naphthalate, and the like. However,
From the viewpoint of its surface gloss, mechanical properties, and availability,
A biaxially stretched PET film is preferably used. And the surface gloss of PET film is ASTM D
The gloss value measured by the method of -523 is 100% or more,
It is preferably 120% or more. If the gloss value is less than 100%, it is not possible to impart sufficient specular gloss to the laminate.

In the present invention, PET may be a homopolymer consisting of terephthalic acid and ethylene glycol, or a copolymer obtained by further copolymerizing terephthalic acid and ethylene glycol with a third component. Such copolymers are known, and the third component is usually an aromatic dicarboxylic acid such as isophthalic acid or naphthalene dicarboxylic acid, an oxycarboxylic acid such as p-hydroxybenzoic acid, propylene glycol, tetramethylene glycol or neopentyl. Alkylene glycol such as glycol and polyalkylene glycol such as polyethylene glycol are used. The ratio of the third component in the copolymer is usually 15 mol% or less.

In the present invention, the raw material of the polyolefin resin layer is not particularly limited, and is low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-ethylene. Ten-1 copolymer, ethylene-α-
Olefin copolymer, ethylene-vinyl acetate copolymer,
Examples thereof include ethylene- (meth) acrylic acid copolymer, ethylene (meth) acrylic acid ester copolymer, polypropylene, and propylene-α-olefin random copolymer.

In the present invention, the adhesive layer is composed of a modified polyolefin modified with an unsaturated carboxylic acid or its anhydride or a polyolefin composition containing the modified polyolefin. The polyolefin is not particularly limited as long as it is selected from the above-mentioned polyolefin-based materials, but in particular, in order to enhance the adhesiveness to a polyester film or a metal substrate, ethylene-
Preference is given to using α-olefin copolymers.

The ethylene-α-olefin copolymer is mainly composed of ethylene, and an α-olefin such as propylene, butene-1, hexene-1, octene-1, 4-methylpentyl-1 was copolymerized with ethylene. The density is generally 0.940 g / cm ³ or less. Particularly, in the present invention, density of 0.930 g / cm ³ or less, more 0.925 g / cm ³ or less of ethylene -α-
Olefin copolymers are preferably used.

Examples of the saturated carboxylic acid or its anhydride include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid and itaconic anhydride. Further, derivatives of unsaturated carboxylic acids or their anhydrides, such as esterification products of monoepoxy compounds with the above acids, reaction products of acids with polymers having a group capable of reacting with these acids in the molecule, and the like are also included. Can be used. Particularly, maleic anhydride is preferably used as the acid.

The graft reaction for modifying the polyolefin may be either a solution method or a slurry method, but the melt-kneading method is preferable from the economical viewpoint. The melt-kneading method can be carried out in the following manner according to a conventional method. First, an unsaturated carboxylic acid or its anhydride and a radical reaction initiator (organic peroxide, azobis compound, etc.) are dry-blended to a powder or pellets of the raw material ethylene-α-olefin copolymer at a predetermined mixing ratio. Alternatively, an unsaturated carboxylic acid or its anhydride and a radical reaction initiator are dissolved in an organic solvent, and the powder or pellet of the ethylene-α-olefin copolymer is sprayed and blended. Blending is performed with a Henschel mixer or the like. Next, the above blend is charged into a kneading machine whose system is replaced with nitrogen gas, such as a Banbury mixer or a double screw mixer, and melt-kneaded under the conditions of 120 to 300 ° C. for 0.1 to 30 minutes. .

The amount of unsaturated carboxylic acid or its anhydride grafted on the modified polyolefin is ethylene-α-
Usually, 0.1 to 5% by weight based on the olefin copolymer,
It is preferably in the range of 0.1 to 3% by weight. When the amount of the unsaturated carboxylic acid or its anhydride is less than 0.1% by weight, the adhesion with the PET film or the metal substrate is insufficient, and when it exceeds 5% by weight, the grafting is not performed. The amount of saturated carboxylic acid or its anhydride component increases and the adhesive strength decreases.

The amount of radical initiator is ethylene-α
-0.1% by weight or less, preferably 0.001 to 0.05% by weight, based on the olefin copolymer. The organic peroxide used as the initiator includes benzoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl peroxylaurate, dicumyl peroxide, α, α′-bis. −
t-butylperoxy-p-diisopropylbenzene,
2,5-Dimethyl-2,5-di-t-butylperoxyhexane, 2,5-di-t-butylperoxyhexyl, t-butylperoxybenzoate, n-butyl-
4,4-bis-t-butyl peroxyvalate, octanoyl peroxide, p-menthane hydroperoxide and the like can be mentioned. Further, as the azobis compound,
Azobisisobutyronitrile, 2,2'-azobis (2,4,4-trismethylvaleronitrile), 2,
2'-azobis (2-cyclopropylpropionitrile) and the like can be mentioned.

In the present invention, when the adhesive layer is made of a polyolefin resin composition, it is preferable to use a polyolefin resin having a melting point of 100 ° C. or higher. When a polyolefin resin having a melting point of less than 100 ° C. is used, the thermal stability is poor and the appearance is deteriorated due to gel or fish eyes. Further, the finally obtained laminate may be subjected to pressurized hot water treatment for surface cleaning after pressing, etc., but the durability of the adhesive strength against the pressurized hot water treatment is poor. There's a problem. As the above polyolefin resin, polyolefin resins such as low density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer are preferably used.

In the adhesive layer made of the polyolefin resin composition, the compounding ratio of the modified polyolefin and the polyolefin resin having a melting point of 100 ° C. or higher is 5:95 to 95:
It is selected from the range of 5 (weight ratio). When the compounding ratio of the modified polyolefin is less than 5% by weight, the adhesiveness to the polyester film or the metal substrate is not always sufficient. On the other hand, when the modified polyolefin compounding ratio exceeds 95% by weight, a stable adhesive force is exhibited from a relatively thin portion to a thick portion of the adhesive layer, but the adhesive force is insufficient.

The melting point of the polyolefin resin referred to in the present invention is determined from the endothermic peak by differential thermal analysis. Since the polyolefin resin is composed of a mixture of two or more kinds, when there are many endothermic peaks, the melting point is determined by the endothermic peaks due to the main component. Further, the polyolefin-based resin needs to be thermally stable so as not to cause fish eyes and gel during film forming, and therefore, conventionally known adhesives such as ionomer resins and ethylene-vinyl acetate copolymers. Copolymers such as ethylene-methacrylic acid copolymers are unsuitable.

The polyolefin resin composition itself has a suitable thermal stability, but it is preferable to stabilize it by adding an antioxidant or the like. The degree of the oxidation reaction time (ORT) measured under the conditions described below is 1 minute or more, preferably 2 minutes or more. Here, the ORT is measured by a differential scanning calorimeter (DSC), and its condition and definition are as follows.

<Sample> 0.5 is obtained by press molding a raw material resin.
Make a sheet with a size of mm ± 0.1mm, and from now on, 5
A sample is cut out to a size of ± 1 mg. <Aeration Volume> Air is passed through the sample cell at a rate of 1 ± 0.1 cc / min. <Rising temperature> The temperature is raised from room temperature to 255 ° C at 40 ° C / min. <Definition of ORT> The time from the completion of temperature increase to the appearance of the exothermic thermogram peak due to the oxidation reaction on the chart.

The additive to be added for stabilizing the polyolefin resin composition may be any known additive, but generally, a phenolic radical scavenger and a thioether or phosphite-based additive are used. It is effective to use a peroxide decomposer together.

As the phenolic radical scavenger,
For example, 2,6-di-tert-butyl-4-methylphenol, 2,4-dimethyl-6-tert-butylphenol, 3
-Tert-butyl-4-hydroxyanisole, 2,6-dioctadecyl-p-cresol, 2,4-dimethyl-6
-Isobonylphenol, 2,6-diisobonyl-p-
Cresol, n-octadecyl-β- (4'-hydroxy-3 ', 5'-di-tert-butylphenol) propionate, styrenated phenol, 2,4-dimethyl-6-α-methylcyclohexylphenol, 4,4 ′
-Butylidene-bis (3-methyl-6-tert-butylphenol), 4,4'-methylene-bis (2,6-di-tert-butylphenol), 2,2'-methylene-bis (6)
-Tert-butyl-p-cresol), 2,2'-methylene-bis (6-tert-butyl-4-ethylphenol), alkylated bisphenol, 2,6-bis (2'-hydroxy-3'-second 3-butyl-5'-methylbenzyl)-
4-methylphenol, tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tetrakis- [methylene- (3,5-di-tert-butyl-4-hydroxy-hydrocinnamate) ] Methane, hydroquinone-monobenzyl ether, 4,4'-thiobis (6-tert-butyl-m-cresol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), bis (2-hydro) Oxy-3,5-di-tert-butylphenyl) sulfide, 2,2'-methylenebis (4-methyl-6-α-methylcyclohexylphenol),
1,3,5-Trimethyl-2,4,6-tris (3,5
-Di-tert-butyl-4-hydroxybenzyl) benzene, 2,4-bis (4-hydroxy-3,5-di-tert-butylphenoxy) -6- (n-octylthio)
-1,3,5-triazine, 6- (4-hydryloxy-3,5-tert-butylanilino) -2,4-bis (n
-Octylthio) -1,3,5-triazine, (4-hydroxy-3,5-di-tert-butylbenzyl) -dioctadecylphosphate ester, phosphorus-alkylated phenol condensate, tetrakis [methylene-3-] (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane and the like.

On the other hand, as peroxide decomposers, dilauryl thiodipropionate, distearyl thiodipropionate, stearyl lauryl thiodipropionate, dilauryl thiodiisobutyrate, distearyl ethylidene dithiodiglycolate, Di-β-naphthyl ethylidene dithiodiglycolate, triphenyl phosphite, trisnonyl phenyl phosphite, diphenyl decyl phosphite, phenyl didecyl phosphite, tridecyl phosphite, trilauryl trithio phosphite, trioctadecyl phosphite, Cyclic neopentane tetrayl bis (octadecyl phosphite), tris- (2,4-di-tert-butylphenyl) phosphite, 4,4'-biphenylenediphosphinic acid tetrakis (2,2 - di - tert-butyl-phenyl)
Mercaptobenzimidazole, mercaptobenzothiazole, zinc ethyl phenyldithiocarbamate, dodecyl mercaptan, thiobis (β-naphthol), thiobis (N-phenyl-β-naphthylamine), phenothiazine, triacrylphosphine, 4,4′-thiobis (3 -Methyl-6-tert-butylphenol), tetramethylthiuram disulphide and the like.

The addition amount of the radical scavenger and the peroxide decomposing agent is not limited as long as the above-mentioned requirements are satisfied. However, if the addition amount is too large, the effect is not exhibited and the bleeding adversely affects the adhesiveness. Be careful as it may affect the performance. Radical scavengers and peroxide decomposers are typically 100
It is added in the range of ppm to 1000 ppm.

In the synthetic resin laminate of the present invention (polyester film / adhesive layer / polyolefin resin layer / adhesive layer), the thickness of the adhesive layer must be selected from the range of 0.5 to 25 μm. The thickness of the adhesive layer is preferably 1 to 20.
μm, more preferably 2 to 12 μm. When the thickness of the adhesive layer is in the above range, the adhesiveness between the polyolefin resin layer and the polyester film or the metal substrate becomes strong. If the thickness of the adhesive layer is less than 0.5 μm, it is difficult to control the thickness, which is not practical.

The thickness of the polyester film and the polyolefin resin layer can be arbitrarily selected, but the thickness of the polyester film is in the range of 10 to 200 μm,
It is preferable that the thickness of the polyolefin resin layer is 150 μm or less, and the total thickness of the laminate is 250 μm or less. When the thickness of the polyester film is less than 10 μm, the unevenness of the metal base material is picked up when laminated on the metal base material, and the smoothness which is the characteristic of the polyester film cannot be obtained, and the depth of gloss cannot be obtained. I have a problem. Further, there is a problem that wrinkles are easily formed during handling. On the other hand, the thickness of the polyester film is 200 μm
If it exceeds, since the film is too thick, various problems occur during secondary processing such as drawing processing performed after laminating on a metal substrate. The total thickness of the laminate is 250 μm
If it exceeds, there is a problem in secondary workability as in the above case.

The haze value of the laminate is ASTM D-10.
The value measured by the method of No. 03 is preferably 30% or less. When the haze value exceeds 30%, the color tone of the coated surface changes when the coated steel sheet is laminated. Haze value is 3
In order to set the content to 0% or less, it is necessary that the polyolefin resin (including the modified polyolefin raw material) that constitutes the laminate is a material that gives the low haze value as described above.

Examples of the above polyolefin resin include low density polyethylene, medium density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer ethylene- (meth) acrylic acid copolymer, ethylene ( Examples thereof include (meth) acrylic acid ester copolymers, polypropylene, and propylene-α-olefin random copolymers. On the other hand, examples of polyolefin resins unsuitable for giving a low haze value include high density polyethylene (particularly high molecular weight), polypropylene block copolymers, filler-reinforced polyolefin filled with a large amount of inorganic substances, and the like. To be

The adhesive layer may be provided on both sides of the polyolefin resin layer by any known method. Examples thereof include a method of extruding and laminating a modified polyolefin or a polyolefin resin composition containing the modified polyolefin on both sides of a polyolefin resin layer having a predetermined thickness, and a method of forming a multilayer by a coextrusion method. The polyolefin resin layer may contain the same additives as those contained in the adhesive layer.

As a method for laminating the polyolefin resin layer and the polyester film, any known method can be adopted. As a general method, the polyolefin resin layer is subjected to corona treatment and then the polyester film is dried by a laminating method. A method of laminating is adopted.
The corona treatment is preferably performed so that the wetting tension of the adhesive surface of the polyolefin resin layer is in the range of 40 to 50 dyne / cm. When laminating, it is preferable to use a known anchor coating agent such as polyurethane type, alkyl titanate type, polyethyleneimine type, or isocyanate type as an anchor coating agent. Further, in order to impart a design property to the laminate, for example, it is possible to previously subject the polyester film to back printing with a desired pattern.

The laminate (polyester film / adhesive layer / polyolefin resin layer / adhesive layer / metal substrate) of the laminate of the synthetic resin film of the present invention and the metal substrate is a synthetic resin obtained as described above. It is obtained by thermally laminating a laminate of films on a metal substrate. The thermal lamination is performed via the adhesive layer of the laminated body of synthetic resin films.

When a coated steel plate is used as the metal substrate,
The type of the coated surface is not particularly limited as long as it has adhesiveness to the above-mentioned adhesive layer, but generally, a polyester-based, epoxy-based, acrylic-based or polyurethane-based coated surface is preferably selected. . The adhesive layer in the present invention exhibits a strong adhesive force to the above coated surface, which is not seen in the conventional example. On the other hand, a vinyl chloride-based coating surface or the like not only does not show adhesiveness to the adhesive layer in the present invention, but also has a problem that a thermal decomposition gas is generated from vinyl chloride during heat treatment of thermal lamination. Yes, it is inappropriate.

The method of thermal lamination may be any known method, for example, a method of hot pressing, a method of press-bonding a preheated metal base material with a roll, and the like. In order to obtain particularly strong adhesiveness, the applicant of the present invention has disclosed in Japanese Patent Laid-Open No. 61-2.
A method disclosed in 91130, that is, a method of laminating a film to be laminated and a metal base material, heating to a temperature equal to or higher than the melting point of the adhesive layer, and immediately followed by rapid cooling can be adopted.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. In the following examples, the performance evaluation of the laminate was performed by the following method. (1) Method for evaluating performance of synthetic resin laminate The adhesive strength (Kg / inch) of the dry laminate part was measured. The adhesive strength was represented by the strength when a 1-inch wide sample was peeled by a 180 ° peel method at a peeling speed of 300 mm / min.

(2) Performance Evaluation Method for Synthetic Resin / Metal Laminate Adhesiveness to Steel Plate An Erichsen test is conducted according to JIS-K6744.
The following ranks were evaluated for floating at the mold notch. A: No abnormality B: Slightly floating C: Clearly floating D: Large floating E: Complete peeling Hot water resistance The test piece obtained as above was treated for 30 minutes in boiling water,
The rise of the mold notch was evaluated by the above rank. Appearance The surface irregularities due to fish eyes and gels in the film were evaluated by visual inspection as ◯ Δx in ascending order.

Examples 1 to 7 and Comparative Examples 1 to 4 (1) Preparation of Modified Polyolefin <Modified Polyolefin A1> Density: 0.88 g / c
m ³ , melt index (MI): 4 g / 10 min of ethylene-butene-1 copolymer mixed with 5000 ppm of maleic anhydride, and grafted with an organic peroxide as an initiator in a single screw extruder. It was prepared by reacting.

<Modified Polyolefin A2> Density: 0.9
It was prepared in the same manner as the modified polyolefin A1 by mixing 1500 ppm of maleic anhydride with an ethylene-butene-1 copolymer having 2 g / cm ³ and MI: 7 g / 10 min.

(2) Preparation of Modified Polyolefin Resin Composition for Adhesion Layer Using a Banbury mixer, the composition having the composition shown in Table 1 was kneaded at 170 ° C. Table 1 shows the oxidation reaction time (ORT) of the obtained composition. The low-density polyethylene (LDPE) and linear low-density polyethylene (LLD) shown in Table 1
The physical properties of PE) and ethylene-vinyl acetate copolymer (EVA) are as follows. LDPE density: 0.922 g / cm ³ , MI: 3.5 g / 10
Min, melting point: 110 ° C. LLDPE density: 0.930 g / cm ³ , MI: 10 g / 10 min,
Melting point: 126 ° C. EVA Vinyl acetate content: 10%, MI: 3.5 g / 10 min, melting point: 96 ° C.

(3) Synthetic resin laminate (PET film /
Adhesive layer / polyolefin resin layer / adhesive layer) Molding density: 0.922 g / cm ³ , MI: 3.5 g / 10 minutes LDPE as stabilizers Irganox 1010 (trade name) and Irgafos 168 manufactured by Ciba-Geigy Coextrusion inflation method of a 50 μm thick three-layer film including an intermediate layer (polyolefin resin layer) of a resin composition containing 0.03 parts of (trade name) and inner and outer layers (adhesive layer) made of modified polyolefin. To form a film at a die temperature of 150 ° C. The thickness of the adhesive layer was adjusted as shown in Table 2. After performing corona treatment on one adhesive layer surface of the above three-layer film so that the surface tension is 42 dyne / cm, a gloss value of surface gloss is 140% and a thickness is 140% when urethane adhesive is used. Of 50μm biaxially oriented PET
The film was dry laminated. The performance evaluation results of the obtained synthetic resin laminate are shown in Tables 2 and 3.

(4) Synthetic resin / metal laminate (lamination of synthetic resin laminate and metal substrate) 0.4 m thick painted in white with polyester paint
m galvanized steel sheet was heated to 200 ° C., the above-mentioned two-layer film was roll-pressed on the coated surface with the adhesive layer in contact with the coated surface, and heat-treated again in an atmosphere of 280 ° C. for 30 seconds, followed by water cooling. To form a laminated body. The performance evaluation results of the obtained synthetic resin / metal laminate are shown in Tables 2 and 3.

Comparative Example 5 (1) Molding of Synthetic Resin Laminate In the above-mentioned molding of synthetic resin laminate, instead of the three-layer film, a two-layer having a thickness of 50 μm having an adhesive layer on only one side of the polyolefin resin layer. A film was used. Then, after subjecting the polyolefin resin layer of the two-layer film to corona treatment so that the surface tension becomes 42 dyne / cm, a urethane adhesive is used to give a gloss value of 140% and a thickness of 50 μm. The biaxially stretched PET film of 1 was dry laminated. The performance evaluation results of the obtained synthetic resin laminate are shown in Tables 2 and 3. (2) Synthetic Resin / Metal Laminate A laminate was obtained in the same manner as the molding of the synthetic resin / metal laminate in (4) above, except that the above two-layer film was used. The performance evaluation results of the obtained synthetic resin / metal laminate are shown in Tables 2 and 3.

[0047]

[Table 1] <(Component proportion of modified polyolefin composition (parts by weight)> ──────────────────────────────── ───── C1 C2 C3 C4 C5 LDPE 70 70 − 4 − LLDPE − − 70 − − EVA − − − − − Modified polyolefin 30 30 30 96 100 Irganox 1010 − 0.03 0.03 0.03 0.03 Irgafos 168 − 0.03 − 0.03 0.03ORT (min) 2 10 10 6 9 (Note) As modified polyolefin, C1 to C4
Use "modified polyolefin A1" for C5
In this case, "modified polyolefin A2" was used.

[0048]

[Table 2] ──────────────────────────────────── Example 1 2 3 4 5 6 7 Adhesive layer composition C1 C2 C3 C3 C4 C5 C5 Adhesive layer thickness (μm) 5 5 5 20 5 5 20 Total thickness of synthetic resin laminate (μm) 50 50 50 50 50 50 50 Haze value of synthetic resin laminate (%) 13 13 16 9 10 12 11 <Performance of synthetic resin / metal laminate> Adhesion with steel plate A A A A A B A B B B Hot water resistance A A A A B B B B Appearance ○ ○ ○ ○ ○ ○ ○ <Performance of synthetic resin laminate> Adhesive strength (Kg / inch) 5.1 5.0 5.0 4.2 4.2 4.7 4.1

[0049]

[Table 3] ──────────────────────────────────── Comparative example 1 2 3 4 5 Adhesive layer Composition C1 C3 C4 C5 C1 Adhesive layer thickness (μm) 35 35 35 35 5 Total thickness of synthetic resin laminate (μm) 100 100 100 100 50 Haze value of synthetic resin laminate (%) 13 20 17 16 13 <Performance of Synthetic Resin / Metal Laminate> Adhesiveness to Steel Sheet CCCCA CA Hot Water Resistance DDDDA Appearance △ ○ ○ ○ ○ <Performance of Synthetic Resin Laminate> Adhesive Strength (Kg / inch) 2.2 5.0 5.0 1.8 1.2

[0050]

According to the present invention described above, the excellent surface gloss, surface hardness, designability, moisture resistance, corrosion resistance, etc. of a polyester film are utilized, and excellent adhesion to a metal substrate is achieved. Provided are a synthetic resin laminate which has properties and is resistant to delamination even in secondary processing having a large degree of deformation, and a laminate of a synthetic resin and a metal substrate using the synthetic resin laminate.

Claims (4)

[Claims] 1. A laminate comprising a polyester film and a polyolefin-based resin layer, wherein the polyolefin-based resin layer contains a modified polyolefin modified with an unsaturated carboxylic acid or an anhydride thereof, or the modified polyolefin. A laminate having an adhesive layer having a thickness of 0.5 to 25 μm, which is made of the polyolefin resin composition described above. 2. A polyester film, a polyolefin-based resin layer, and a metal substrate are sequentially laminated, and a polyolefin modified with an unsaturated carboxylic acid or an anhydride thereof or the modified polyolefin is formed on both surfaces of the polyolefin-based resin layer. A laminate having an adhesive layer having a thickness of 0.5 to 25 μm, which is made of a polyolefin resin composition containing a polyolefin. 3. The laminate according to claim 1, wherein the modified polyolefin is a modified polyolefin obtained by grafting an ethylene-α-olefin copolymer with 0.1 to 5% by weight of an unsaturated carboxylic acid or an anhydride thereof. body. 4. A polyolefin-based resin composition containing a modified polyolefin, wherein the polyolefin-based resin composition has a modified polyolefin of 5 to 95% by weight and a melting point of 100 ° C. or higher.
The laminate according to any one of claims 1 to 3, which is a composition containing 100% by weight (however, the total amount of the two is 100% by weight).