JP4561077B2 - Laminating film, laminating material, can body and can lid - Google Patents

Description

  The present invention relates to a film made of a copolymerized polyester resin containing a polyfunctional component and a copolymer component, and a laminate material coated with this film. More specifically, high-speed lamination of a film and a metal plate is possible. The present invention relates to a film that can be coated on a metal plate with excellent thickness uniformity and adhesion, and a laminate material excellent in workability formed by coating this film.

  Conventionally, as a means for imparting corrosion resistance to a metal material, it is widely performed to coat a metal surface with a resin layer, and as a coating method used in such a technique, an epoxy resin, a phenol resin, an acrylic resin, A method in which a thermosetting resin such as a polyester resin is dispersed in a solvent is applied to a metal surface, or a pre-formed film, for example, a polyester, olefin, or polyamide film is an isocyanate, epoxy, A method of bonding to a metal substrate via a phenol-based adhesive or the like is known.

  It is also widely known that the heat-fusibility of a thermoplastic resin is used for bonding a metal substrate and a thermoplastic resin. In this method, a preformed film such as a thermoplastic polyester resin is applied to a metal plate. There are known a method of bonding by thermal bonding and a method of bonding a molten thin film such as an extruded thermoplastic polyester resin to a metal plate.

The latter method of bonding to a metal plate by the extrusion laminating method is advantageous in that it can process at a very high speed and can reduce the work involved in film formation and the cost for it.
As the extrusion laminating method, a T-die method using an extruder and a T-die is generally adopted. However, in such a T-die method, unstable flow inside the extruder and the die, or between the T-die and the metal plate. Since there is a slight air gap between them, when general polyester is used, film sway, pulsation, etc. occur, and a stable and uniform coating layer can be formed on the metal plate with good adhesion. It is difficult to form. These phenomena are particularly likely to occur when the resin take-up speed is increased, making high-speed lamination of the polyester resin very difficult.

Various proposals have been made to solve the above-described problems. For example, the applicant of the present invention has a melt viscosity ratio at a temperature at the time of melt extrusion (melt viscosity η at a preceding stage speed of 12.2 sec ⁻¹ at the extrusion temperature of polyester. _12.2 / The melt viscosity η ₁₂₁₆ at a shear rate of ₁₂₁₆ sec ⁻¹ at the extrusion temperature of polyester is 2.0 or more and η ₁₂₁₆ is 500 poise or more, and the resin layer is melt-extruded and then rapidly cooled. A laminate characterized by the fact that an ethylene oxide adduct of bisphenol or a polyester resin containing a tribasic or higher polybasic acid and a polyhydric alcohol is used. Describes that a coating with excellent uniformity and adhesion can be obtained. That (Patent Document 1).

  Further, a polyester mainly composed of ethylene terephthalate containing 0.1 to 2.0 mol% of a compound having 3 or 4 ester bond-forming functional groups, and having a melting point of 220 ° C. or higher, the melting point of the polyester + 40 ° C. It is described that a polyester having a die swell measured at a temperature of 1.3 or more is excellent in extrudability (Patent Document 2).

JP 10-86308 A JP 2001-72747 A

However, the above-described film for laminating is not yet satisfactory in terms of adhesion to a metal material, and further adhesion of the coating is required.
Therefore, the object of the present invention is that even when laminated on a metal plate by a high-speed extrusion laminating method, it is possible to coat the metal plate with a uniform film thickness and good adhesion without causing the above-mentioned film shaking and pulsation. And a laminate material excellent in adhesion of a film formed using the film.

According to the present invention, the polyfunctional component is contained in an amount of 0.01 to 0.50 mol%, the copolymer component is contained in an amount of 10 to 20 mol%, and the melt tension is 50 mN or more. A film for laminating is provided.
In the laminating film of the present invention,
1. The copolymerization component is isophthalic acid,
2. The melting point of the copolyester resin is less than 220 ° C.,
Is preferred.

According to the present invention, there is also provided a laminating material, wherein the laminating film is laminated so as to be in contact with a metal substrate.
In the laminate material of the present invention, it is preferable that another resin layer is further formed on the laminate film.
The present invention further provides a can and a can lid made of the laminate material.

According to the present invention, even when extrusion lamination is performed on a metal substrate at high speed, the occurrence of film sway and pulsation is effectively prevented, and a laminate material that is remarkably excellent in the uniformity of the coating layer, in particular, the adhesion is provided. it can.
In addition, since the laminate material of the present invention is excellent in the uniformity and adhesion of the film, it can be used for severe processing such as drawing, drawing / deep drawing, drawing / ironing, drawing / bending / drawing / ironing. Has excellent workability to withstand.

  In the laminating film of the present invention, a copolymerized polyester containing a polyfunctional component in an amount of 0.01 to 0.50 mol%, a copolymer component in an amount of 10 to 20 mol%, and a melt tension of 50 mN or more. By being made of resin, even when laminating to a metal substrate at high speed, film shaking and pulsation can be prevented, and a film having a uniform film thickness can be supplied to the metal base resistance. This makes it possible to provide a laminate material with excellent adhesion.

That is, since a general polyester resin (polyethylene terephthalate) has a low melt tension and melt viscosity, when extruded and laminated to a metal substrate at a high speed, a phenomenon of film shaking in which the end in the width direction of the molten resin film coming out of the T-die is shaken, A phenomenon called pulsation occurs in which the molten resin film coming out of the T-die has uneven thickness in the longitudinal direction. For this reason, a uniform film thickness cannot be obtained, and adhesion to the metal substrate is also lowered. On the other hand, an increase in melt tension is accompanied by a marked increase in viscosity, so that ordinary extruders are inferior in extrudability and cannot be extruded at high speed.
In the present invention, from such a viewpoint, when the polyester resin contains 0.01 to 0.50 mol% of a polyfunctional component, the polyfunctional component is introduced into the polyester main chain, and a branched chain or a crosslinked chain is formed. The film tension and the pulsation are effectively prevented even by extrusion laminating at a high speed with the melt tension set to 50 mN or higher without excessively increasing the melt viscosity.

  Such operational effects of the present invention are also apparent from the results of Examples described later. That is, a polyfunctional component is not contained, and a copolyester resin (Comparative Example 1) having a melt tension of less than 50 mN or a polyfunctional component is contained in an amount within the above range, but the melt tension is less than 50 mN. In the polymerized polyester resin (Comparative Example 2), when extruded at a speed of 100 m / min, film shaking occurs, whereas the polyfunctional component is contained in the above amount, and the melt tension is 50 mN or more. The copolymerized polyester resin (Examples 1 to 4) is free from film shaking and pulsation, the copolymerized polyester resin contains a polyfunctional component of 0.01 to 0.50 mol%, and the melt tension is 50 mN or more. It is understood that excellent high-speed extrusion laminating properties are exhibited.

On the other hand, in such a polyester film laminate material, it is desired to further improve the adhesion of the film. However, in the present invention, a copolymer component, particularly isophthalic acid is used as a polyester resin in an amount of 10 to 20 mol%. In particular, the copolyester resin contained in the above amount is used, so that the adhesion of the film to the metal substrate can be improved. In particular, in the present invention, the amount of the copolymer component is adjusted so that the melting point of the copolymer polyester resin is less than 220 ° C., particularly 200 to 219 ° C. It is preferable in terms of improvement.
Such operational effects of the present invention are also apparent from the results of Examples described later. That is, in the copolyester resin (Examples 1 to 4) containing isophthalic acid in an amount within the above range, excellent results in film adhesion were obtained, whereas isophthalic acid was completely blended. In the non-homopolyester resin (Comparative Example 3) and the copolymer polyester (Comparative Example 4) having a lower amount of isophthalic acid than the above range, the adhesion of the film is inferior to that in the above range. It is clear that In addition, the copolymer polyester resin (Comparative Example 5) having an isophthalic acid amount exceeding the above range is inferior in heat resistance, and the isophthalic acid amount being in the above range has both adhesion and heat resistance. Understood to be important.

(Copolymerized polyester resin)
The copolymer polyester resin used in the present invention has a polyfunctional component of 0.01 to 0.50 mol%, particularly 0.05 to 0.40 mol%, and a copolymer component of 10 to 20 mol%, particularly 11 to 17 mol. %, And a polyester resin composed of a conventionally known dicarboxylic acid component and diol component can be used except that the melt tension is 50 mN or more.
That is, by introducing a polyfunctional component having three or more functional groups into the polyester main chain, it is possible to form a branched chain or a crosslinked chain and to prepare a melt tension of 50 mN or more, and to convert isophthalic acid into a dicarboxylic acid component. As a result, the melting point and crystallinity are lowered, and the adhesion, that is, the adhesion to the metal substrate can be improved.

  As the dicarboxylic acid component, it is particularly preferable to contain isophthalic acid in the range of 10 to 20 mol%, particularly 11 to 17 mol%, and 50% or more, particularly 80% of the remaining dicarboxylic acid component is terephthalic acid. Although it is preferable from the mechanical property and thermal property of the coating layer, it can of course contain a carboxylic acid component other than terephthalic acid. Examples of carboxylic acid components other than terephthalic acid include naphthalenedicarboxylic acid, p-β-oxyethoxybenzoic acid, biphenyl-4,4′-dicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, and 5-sodium sulfoisophthalate. Examples include acid, hexahydroterephthalic acid, adipic acid, sebacic acid and the like.

  As the diol component, it is preferable from the mechanical properties and thermal properties of the coating layer that 50% or more, particularly 80% or more of the diol component is ethylene glycol. As the diol component other than ethylene glycol, 1,4- Examples include butanediol, propylene glycol, neopentyl glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, cyclohexane dimethanol, ethylene oxide adduct of bisphenol A, glycerol, trimethylolpropane, and the like.

The polyfunctional component is a tribasic or higher polybasic acid or polyhydric alcohol, trimellitic acid, pyromellitic acid, hemimellitic acid, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2- Polybasic acids such as ethanetricarboxylic acid, 1,3,5-pentanetricarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, biphenyl-3,4,3 ′, 4′-tetracarboxylic acid, Polyhydric alcohols such as pentaerythritol, glycerol, trimethylolpropane, 1,2,6-hexanetriol, sorbitol, 1,1,4,4-tetrakis (hydroxymethyl) cyclohexane are exemplified.
The copolymer component can be arbitrarily selected from the above dicarboxylic acid component and diol component, but isophthalic acid can be most preferably used.

  The content of the polyfunctional component is preferably 0.01 to 0.50 mol%, particularly 0.05 to 0.40 mol% per polyester, and if less than the above range, the melt tension is 50 mN or more. However, if it exceeds the above range, the melt-extrusion properties will be lowered, and the mechanical properties and heat resistance as the coating layer will be reduced. There is a tendency to decrease.

The copolymer polyester resin of the present invention has an intrinsic viscosity of 0.5 to 2.0 dl / g, particularly 0.6, measured using a phenol / tetrachloroethane mixed solvent from the viewpoint of physical properties of the coating layer and melt extrusion characteristics. It is preferably in the range of 1.5 dl / g.
Furthermore, in order to satisfy heat resistance, workability, and melt-extrusion characteristics as well as film adhesion, it preferably has a melting point (Tm) of less than 220 ° C., particularly 200 to 219 ° C. The glass transition point is preferably 30 ° C. or higher, particularly 50 to 120 ° C.

  The polyester resin layer used in the present invention has a resin compounding agent known per se, for example, an antiblocking agent such as amorphous silica, a pigment such as titanium dioxide (titanium white), an antioxidant, a stabilizer, and various electrifications. Inhibitors, lubricants, and the like can be blended according to known formulations.

(Metal base)
In the present invention, as the metal substrate on which the film is laminated, various surface-treated steel plates, light metal plates such as aluminum, or these foils are used.
Surface-treated steel sheets are steel sheets that have been cold-rolled steel sheets after temper rolling or secondary cold rolling, that is, SR materials and DR materials, galvanized, tin-plated, nickel-plated, electrolytic chromic acid treatment, chromic acid treatment What performed 1 type or 2 types or more of surface treatments, such as these, can be used. An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet, which has a metal chromium layer of 10 to 200 mg / m ² and a chromium oxide layer of 1 to 50 mg / m ² (in terms of metal chromium). This product is excellent in the combination of coating film adhesion and corrosion resistance. Another example of the surface-treated steel plate is a hard tin plate having a tin plating amount of 0.6 to 11.2 g / m ² . This tin plate is preferably subjected to chromic acid treatment or chromic acid / phosphoric acid treatment so that the amount of chromium is 1 to 30 mg / m ^{2 in} terms of metallic chromium. As yet another example, an aluminum-coated steel sheet subjected to aluminum plating, aluminum pressure welding, or the like is used.

As the light metal plate, an aluminum alloy plate is used in addition to a so-called pure aluminum plate. The aluminum alloy plate excellent in terms of corrosion resistance and workability is Mn: 0.2 to 1.5% by weight, Mg: 0.8 to 5% by weight, Zn: 0.25 to 0.3% by weight , And Cu: 0.16 to 0.26% by weight, with the balance being Al. These light metal plates are also desirably subjected to chromic acid treatment or chromic acid / phosphoric acid treatment so that the chromium amount is 20 to 300 mg / m ^{2 in} terms of metal chromium.

  The thickness of the metal plate varies depending on the type of metal and the use or size of the laminate material, but generally it should have a thickness of 0.10 to 0.50 mm. .10 to 0.30 mm, and in the case of a light metal plate, the thickness should be 0.15 to 0.40 mm.

When laminating the film of the present invention and a metal substrate by an extrusion laminating method, the film of the present invention is excellent in adhesion to the metal substrate. An adhesion primer can also be provided.
Such a primer exhibits excellent adhesion to both a metal substrate and a polyester resin, and as a typical primer coating excellent in adhesion and corrosion resistance, various phenols and A phenol-epoxy-based paint composed of a resol-type phenol aldehyde resin derived from formaldehyde and a bisphenol-type epoxy resin, particularly a phenol resin and an epoxy resin in a weight ratio of 50:50 to 5:95, particularly 40:60 to 10 : Paint containing at a weight ratio of 90. The adhesive primer layer is generally preferably provided with a thickness of 0.3 to 5 μm.

(Laminate)
In the laminate material of the present invention, as shown in FIG. 1, the film 3 of the present invention is laminated so as to be in contact with the metal substrate 2. As described above, another film 4 can be further laminated on the film 3.
When the laminate material of the present invention is formed into a can or a can lid, the film of the present invention must be formed on at least the inner surface of the can or the can lid. The film of the present invention can also be laminated on the side surface.
That is, FIG. 1 shows an example of the cross-sectional structure of the laminate material of the present invention. The laminate material 1 is composed of a metal substrate 2 and a copolymer polyester resin layer 3 made of the above-described copolymer polyester resin. FIG. 2 shows another example of the cross-sectional structure of the laminate material of the present invention. This laminate material 1 is composed of a metal substrate 2, a copolymer polyester layer 3, and another polyester resin layer 4 on the copolymer polyester layer 3. Is formed. Further, FIG. 3 is the same as FIG. 2 except that the copolyester layer 5 is also formed on the other surface which is the outer surface side of the laminate shown in FIG.

In the laminate material of the present invention, as a film that can be laminated together with the above-described film of the present invention, a film made of a conventionally known polyester resin, polyethylene terephthalate, or the like can be suitably used. Since it is provided as the upper layer of the polymerized polyester resin layer, it is a polyester resin mainly composed of ethylene terephthalate, in which 80 mol% or more of the dicarboxylic acid component having excellent flavor properties is composed of terephthalic acid and 80% or more of the diol component is ethylene glycol. Is particularly preferred.
Further, from the viewpoint of preventing extrusion laminating properties at high speed, i.e., occurrence of pulsation and film shaking, the polyester resin (B) has a ratio of melt tension with the copolymer polyester resin (A) of A: B = 1. Preferably in the range of 1: 1 to 10: 1.
Furthermore, when forming another polyester resin layer (B) on the copolyester resin layer (A), the ratio of these thicknesses is in the range of A: B = 50: 1 to 1: 5. It is preferable.

In addition, the polyester resin has an intrinsic viscosity of 0.5 to 2.0 dl / g, particularly 0.6 to 1 in terms of the physical properties of the coating layer and the melt-extrusion properties, measured using a phenol / tetrachloroethane mixed solvent. Preferably it is in the range of 5 dl / g. Furthermore, it preferably has a melting point (Tm) of 200 to 219 ° C., particularly 205 to 218 ° C., from the viewpoints of adhesion, heat resistance, processability and melt extrusion properties. The glass transition point is preferably 30 ° C. or higher, particularly 50 to 120 ° C.
Also in the layer made of this polyester resin or the like, the above-mentioned conventionally known compounding agent for resins can be blended according to a known formulation as in the case of the copolymerized polyester resin layer.

(Lamination method)
The film of the present invention can be formed by extrusion molding such as a T-die method or an inflation film formation method. In the case of a multilayer film in which a film made of another polyester resin is further formed as an upper layer, a resin is formed by co-extrusion molding. Except for using a multilayer multiple die, the number of extruders corresponding to the type of the resin is melted and kneaded with the respective extruders in the same manner as in the normal T-die method and inflation method, and then T-die, annular die, etc. It can be formed by extrusion through a multilayer film. Of course, the films made of the respective resins can be laminated by molding them by extrusion molding such as T-die method or inflation film forming method, and bonding them.
The film can also be used as an unstretched film by a cast molding method in which an extruded film is quenched, and this film is biaxially stretched successively or simultaneously at a stretching temperature, and the stretched film is heat-set. It can also be used as a produced biaxially stretched film.

  The laminate material obtained by laminating the film of the present invention on a metal substrate is a dry lamination of a film made of the above-mentioned copolymerized polyester resin, or a multilayer film in which a layer made of another resin is formed thereon if necessary. The film of the present invention is excellent in the extrusion laminating property at a high speed as described above, and is particularly by the extrusion lamination method described later. preferable. As a result, processing at a very high speed is possible, and work associated with film formation, such as film winding, and costs for it can be reduced.

Next, an extrusion lamination method that can be suitably used for the laminate material of the present invention will be described by taking as an example the molding of a laminate material in which a layer made of another polyester resin is formed on a layer made of a copolyester resin.
In FIG. 4 which shows arrangement | positioning of the apparatus used for an extrusion lamination method, along the channel | path 12 of the metal base | substrate 11, the heating area | region 13 of a metal base | substrate and the copolyester resin made to be opposed to the channel | path 12 of a metal base | substrate Extruders 14a and 14b, other polyester resin extruders 14c and 14d are fed in a film shape, a pair of multi-layer dies 15a and 15b, and films extruded from the dies 15a and 15b are opposite to the adhesion surface to the metal substrate 11. The pre-rolls 16a and 16b received from the side (other polyester resin side) and over the entire width of the film, the films 17a and 17b from the pre-rolls 16a and 16b, and the copolymer polyester resins 14a and 14b and other polyesters on both surfaces of the metal substrate 11 A pair of laminating rolls 18a and 18b to which the resins 14c and 14d are bonded, and a laminating material 1 to be formed A quench unit 20 for quenching the is located.
In the apparatus shown in FIG. 4, a lower layer made of a copolyester resin and an upper layer made of another polyester resin are respectively formed on both sides of the metal substrate. Of course, the copolyester resin layer and the upper layer are made only on one side of the metal substrate. It is also possible to form a layer made of another polyester resin as described above. In this case, one of the dies may not be used.

In the apparatus shown in FIG. 4, the metal substrate 11 is passed between the pair of laminate rolls 18a and 18b and in a direction substantially perpendicular to the line connecting the centers of the laminate rolls 18a and 18b, and from the dies 15a and 15b. The polyester resin melt film 17 is received by the pre-rolls 16a and 16b, supported and conveyed by the corresponding laminating rolls 18a and 18b, and supplied to the nip position 21 between the laminating rolls. The multilayer film 17 is fused at the same time.
As a result, it is possible to prevent deterioration of performance due to excessive heating of the metal substrate and the polyester resin, and it is possible to simultaneously coat the polyester resin on both surfaces of the metal substrate, and the resin temperature necessary for adhesion to the metal substrate by the pre-roll. The resin film is cooled while securing the film, and it is possible to prevent film shaking and excessive neck-in at the time of extrusion lamination, thereby improving the yield of products without reducing the film width of the flat portion. In addition, it is possible to produce a laminate material having a high polyester resin coating and high performance, that is, thickness uniformity, high workability, high adhesion, high film properties, and the like at high speed.

In the production of the laminate material using the apparatus shown in FIG. 4, the metal substrate 11 heated in the heating zone 13 is guided to the nip position of the laminate rolls 18a and 18b, but the metal substrate passage 2 and the laminate roll 18a, 18b is provided in the above positional relationship, the metal substrate 11 is prevented from coming into contact with other members until the nip position 21 of the laminate rolls 18a and 18b is reached, and the surface temperature of the metal substrate 11 is reduced. Therefore, the slowest speed corresponding to the cooling rate in the air is maintained.
For this reason, the temperature and heat capacity of the metal substrate 11 can be effectively used for heat fusion with the polyester resin thin film, and it is high without requiring reheating between the polyester resin film 17 and the metal substrate 11. Adhesive strength can be obtained.

  Resin metal laminate material discharged from the laminating roll is introduced into a quenching means and rapidly cooled, so that the resin coating is a thin film and has high performance, that is, thickness uniformity, high workability, high adhesion, and high film properties. Or the like.

(Can body and can lid)
The can body of the present invention can be produced by making the above-mentioned laminate material into a two-piece can or a three-piece can by a conventionally known molding method.
In particular, seamless cans having no side seams are preferable, and they are manufactured by means such as drawing, drawing / deep drawing, drawing / ironing, drawing / bending / drawing / ironing. The side wall of the resin-coated metal sheet is thinned so as to have a thickness of 20 to 95%, particularly 30 to 85% of the original thickness of the resin-coated metal sheet by bending and stretching by drawing-redrawing or further ironing. It is preferable that

In addition, the can lid of the present invention can be formed from the above-described laminate material by a conventionally known method for producing can lids.
Moreover, the shape of a can lid can employ | adopt conventionally well-known shapes, such as an easy open end provided with the score for forming the opening for content extraction, and the tab for opening.

The invention is illustrated by the following examples.
The characteristic values of the present invention are based on the following measurement methods.

(1) Melting point (Tm)
Using a differential scanning calorimeter DSC7 (manufactured by Perkin Elmer), about 5 mg of resin was heated at a rate of 10 ° C./min under a nitrogen stream, and the maximum endothermic peak temperature based on crystal melting at that time was determined. Tm.

(2) Intrinsic viscosity (IV)
The resin was dissolved in a 1: 1 mixed solution of phenol and tetrachloroethane in a weight ratio and measured at 30 ° C. with an Ubbelohde viscometer.

(3) Melt tension Resin is supplied to a segment twin screw extruder 2D25W type manufactured by Toyo Seiki Seisakusho, melt extrusion is performed at a discharge rate of 1.5 kg / hr, a resin temperature of 240 ° C., and L / D = The molten resin from the 15 mm / 3 mm strand die was drawn at 100 m / min, and the melt tension was measured with a load cell at a position 450 mm from the die outlet.

(4) High-speed laminating properties Using a T-die twin screw extruder as shown in Fig. 4, the resin melted at 260 ° C is extruded onto an aluminum alloy plate at 100 m / min for laminating, and the occurrence of film shaking and pulsation is observed. confirmed. The evaluation criteria are shown below.
[Membrane shake]
The width of the film sway was evaluated as a ratio to the width of the obtained resin film.
Less than 2%… ○
2% or more… ×
[pulsation]
Measure the thickness of the resin film of the obtained laminate material over the longitudinal direction of 500 mm,
Evaluation was based on the ratio of the fluctuation width of the measured thickness to the average thickness of the resin coating.
Less than 10%… ○
10% or more… ×

(5) Can-making suitability Using a resin-coated aluminum alloy plate obtained by extrusion lamination, a 350 ml can having an inner diameter of 66 mm and a height of 122 mm was DI-molded, and processability and adhesion were evaluated according to the following criteria. In the DI molding, a resin-coated aluminum alloy plate coated with a lubricant was drawn and then redrawed in a dry state and subjected to three-stage ironing to produce a can.
[Machinability]
Evaluated based on the presence or absence of broken and buckling at the time of can-making
Destruction or buckling occurred… ×
[Adhesion]
The film peeling and lifting during can making were visually evaluated.
No film peeling or lifting was observed.
Film peeling and lifting were seen… ×

Example 1
A polyester resin having the composition shown in Table 1 was fed onto an aluminum alloy plate (A3004H19 material) having a thickness of 0.280 mm heated to 250 ° C. to an extruder of 65 mmφ equipped with an extrusion lamination facility, and then the melting point of the resin. It was melt-extruded to a thickness of 16 μm at a temperature 30 ° C. higher and laminated on both sides of the aluminum alloy plate.
The characteristic values and evaluation results of the resins are shown in Tables 1 and 2. Film lamination and pulsation did not occur at 100 m / min, and good lamination was possible. The ability to make cans was also good.

Example 2
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Film lamination and pulsation did not occur at 100 m / min, and good lamination was possible. The ability to make cans was also good.

Example 3
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Film lamination and pulsation did not occur at 100 m / min, and good lamination was possible. The ability to make cans was also good.

Example 4
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Film lamination and pulsation did not occur at 100 m / min, and good lamination was possible. The ability to make cans was also good.

Comparative Example 1
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Since no polyfunctional component was contained in the polyester resin, the melt tension was low, and severe film shaking occurred at 100 m / min. Therefore, film thickness unevenness occurred in the coating resin of the laminate material, and a broken cylinder occurred during can making.

Comparative Example 2
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. The polyfunctional component was contained in the polyester resin, but the melt tension was low, and film shaking occurred at 100 m / min. Therefore, film thickness unevenness occurred in the coating resin of the laminate material, and a broken cylinder occurred during can making.

Comparative Example 3
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Although the high-speed coatability was good, since the polyester resin did not contain a copolymer component, film peeling and lifting were observed during canning.

Comparative Example 4
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Although the high-speed coatability was good, film peeling and lifting were observed during canning because the content of the copolymer component in the polyester resin was low.

Comparative Example 5
Example 1 was repeated except that a resin having the composition shown in Table 1 was used. Tables 1 and 2 show resin characteristic values and evaluation results. Although the high-speed coatability was good, the content of the copolymer component in the polyester resin was high, so that the melting point was remarkably lowered and the heat resistance was poor, and punching was poor and buckling occurred during canning.

It is a figure which shows the cross-section of an example of the laminate material of this invention. It is a figure which shows the cross-section of another example of the laminate material of this invention. It is a figure which shows the cross-sectional structure of another example of the laminate material of this invention. It is a figure which shows an example of the apparatus which manufactures the laminate material of this invention.

Claims (7)

  A laminate comprising a copolymerized polyester resin containing 0.01 to 0.50 mol% of a polyfunctional component, 10 to 20 mol% of a copolymer component, and a melt tension of 50 mN or more. Film.   The film for laminating according to claim 1, wherein the copolymer component is isophthalic acid.   The film for laminating according to claim 1 or 2, wherein the copolymer polyester resin has a melting point of less than 220 ° C.   A laminate material comprising the film according to any one of claims 1 to 3 laminated so as to be in contact with a metal substrate.   The laminate material according to claim 4, wherein another resin layer is further formed on the film.   A can made of the laminate material according to claim 4 or 5.   A can lid made of the laminate material according to claim 4.

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