JP2677512B2 - Resin-coated metal plate for squeezed ironing can and squeezed ironing can - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin-coated metal sheet for drawn and ironed cans and a drawn and ironed can made of this resin-coated metal sheet, and more specifically to a resin-coated metal sheet for drawn and ironed cans in which specific resin layers are laminated. And a drawn and ironed can made of this resin-coated metal plate.

[0002]

BACKGROUND OF THE INVENTION Conventionally, drawn and ironed cans (hereinafter referred to as DI cans) obtained by drawing and ironing a steel plate such as a tin plate or an aluminum plate are seamless and have excellent physical properties, and are widely used. ing.

In such a DI can, a resin layer is provided on the inner surface of the can in order to prevent deterioration of taste, deterioration of flavor, alteration of contents and generation of pinholes due to metal elution from the metal plate. May be provided. Examples of such a can in which a resin layer is provided on the inner surface side of the can and a resin-coated metal plate capable of forming such a can are disclosed in, for example, JP-A-51-1.
Japanese Patent No. 30647 proposes a steel sheet coated with a saturated polyester layer and a container obtained from the steel sheet.
Further, JP-A-1-180336 proposes a steel sheet coated with a polybutylene terephthalate layer,
JP-A-1-192545 and JP-A-2-57339.
Japanese Patent Laid-Open No. 10835/1993 proposes a steel sheet coated with a specific saturated copolyester layer and a container obtained therefrom.

By the way, the coating resin used for the steel sheet for drawing and ironing cans is required to have excellent formability capable of following the drawing and ironing process, and also to have excellent adhesiveness so as not to peel from the steel sheet. . Further, this resin is required to have excellent impact resistance capable of withstanding impacts during canning, canning process and transportation. In addition, there are required pinholes that do not cause corrosion during storage, and characteristics that do not affect the taste of the beverage, that is, have excellent flavor properties.

However, the resin coated on the conventional steel sheet for cans does not always satisfy such requirements. For example, pinholes may be formed in the resin coating during drawing and ironing. Moreover, the impact resistance of the cans that have been heated in the processes such as drying, printing, and baking after the cans may decrease.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and is excellent in drawing and ironing formability, excellent adhesion to a metal plate and excellent impact resistance, and further pinholes. It is an object of the present invention to provide a resin-coated metal plate on which a resin layer having characteristics such as excellent flavor characteristics is laminated, and a drawn and ironed can made of such a resin-coated metal plate.

[0007]

SUMMARY OF THE INVENTION A resin-coated metal plate for a squeezing and ironing can according to the present invention comprises a metal plate and a resin coating provided on one surface of the metal plate. The resin coating comprises [A] dicarboxylic acid and dihydroxy. And a crystalline saturated polyester resin layer composed of 99 to 85 mol% terephthalic acid and 1 to 15 mol% isophthalic acid, when the dicarboxylic acid component is 100 mol%. ] (A) Saturated polyester resin: 75 to 99 parts by weight,
And (b) an ionomer resin: a resin composition layer composed of 25 to 1 part by weight and two layers, and the [B] resin composition layer is laminated so as to be in contact with the metal plate. .

The squeezed ironing can according to the present invention is formed of the resin-coated metal plate as described above.

[0009]

DETAILED DESCRIPTION OF THE INVENTION A resin-coated metal plate for a drawn and ironed can according to the present invention and a drawn and ironed can made of the resin-coated metal plate will be described below.

The resin-coated metal plate for a drawn and ironed can according to the present invention comprises a metal plate and a resin composition coating film provided on one side of the metal plate. In the present invention, conventionally known metals that are generally used for cans are widely used as the metal plate, and specifically, a steel plate (tin plate) or tin whose surface is Sn (tin) plated by a known method. None steel plate (tin-free steel, electrolytic chromic acid treated steel plate) or aluminum plate is used.

This metal plate usually has a thickness of 0.01-5.
mm, preferably 0.1 to 2 mm. On one side or both sides of this metal plate, two layers of [A] crystalline saturated polyester resin layer and [B] (a) saturated polyester resin and (b) resin composition layer composed of ionomer resin are formed. A resin film is formed.

The crystalline saturated polyester resin (A) and the saturated polyester resin (a) used in the present invention are composed of structural units derived from a dicarboxylic acid and a dihydroxy compound.

Of these, the crystalline saturated polyester resin [A] is a copolyester containing a dicarboxylic acid component derived from two specific dicarboxylic acids. The dicarboxylic acid component forming the [A] crystalline saturated polyester resin used in the present invention is 100% dicarboxylic acid component.
When defined as mol%, terephthalic acid is 99 to 80 mol%,
Preferably 95-85 mol% and isophthalic acid 1-20
Mol%, preferably 5 to 15 mol%.

Further, as the dihydroxy component forming the crystalline saturated polyester resin [A], specifically,
Aliphatic dihydroxy compounds such as ethylene glycol, trimethylene glycol (propylene glycol), tetramethylene glycol, pentamethylene glycol, diethylene glycol and triethylene glycol can be mentioned.

The crystalline saturated polyester [A] as described above is trimesic acid, within a range not impairing the object of the invention.
The constitutional unit derived from a polyfunctional compound such as pyromellitic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, and pentaerythritol may be contained in a small amount, for example, 2 mol% or less.

The crystalline saturated polyester [A] used in the present invention is substantially linear, which is confirmed by the fact that the saturated polyester is dissolved in o-chlorophenol.

The crystalline saturated polyester [A] used in the present invention has an intrinsic viscosity [η] measured in o-chlorophenol at 25 ° C. of usually 0.5 to 1.4 dl /
g, preferably 0.5 to 1.0 dl / g, and more preferably 0.6 to 1.0 dl / g.

Saturated polyesters having such an intrinsic viscosity [η] are preferable because they are excellent in melt moldability and draw-ironing formability, as well as in mechanical strength such as impact resistance.

The crystalline saturated polyester resin [A] used in the present invention usually has a glass transition temperature (Tg) of 50.
To 120 ° C, preferably 60 to 100 ° C, the low temperature crystallization temperature (Tc) is usually 130 to 210 ° C, preferably 140 to 200 ° C, and the crystal melting temperature (Tm) is
It is usually 210 to 265 ° C., preferably 220 to 260 ° C.

The crystalline saturated polyester resin [A] used in the present invention has a crystallinity of 5 to 75%, preferably 10 to 60% as measured by an X-ray diffraction method.

The crystalline saturated polyester resin [A] used in the present invention having the above composition is excellent in processability, and the film formed from the crystalline saturated polyester resin [A] is terephthalic. Compared to a coating film formed of a conventionally known polyester resin derived from an acid and ethylene glycol, it is less likely to adsorb terpene-based odor and is excellent in aroma retention.

In the present invention, (a) the saturated polyester resin used when forming the resin composition layer [B] has a dicarboxylic acid component of terephthalic acid or its ester derivative (eg lower alkyl ester, phenyl ester, etc.). And the dihydroxy component is ethylene glycol or an ester-forming derivative thereof (for example, monocarboxylic acid ester ethylene oxide).

The saturated polyester (a) may contain a structural unit derived from another dicarboxylic acid and / or another dihydroxy compound in an amount of 40 mol% or less. Specific examples of dicarboxylic acids other than terephthalic acid include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid; adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid. Aliphatic dicarboxylic acids such as acids; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and the like.

Dicarboxylic acids other than these terephthalic acids may be used as their ester derivatives. Specific examples of the dihydroxy compound other than ethylene glycol include propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol. Glycol; alicyclic glycol such as cyclohexanedimethanol; bisphenols, hydroquinone, 2,2-bis (4-
and aromatic diols such as β-hydroxyethoxyphenyl) propane.

These dihydroxy compounds may be used as their ester derivatives. The (a) saturated polyester used in the present invention has a small amount of a structural unit derived from a polyfunctional compound such as trimesic acid, pyromellitic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, and pentaerythritol, for example, 2 It may be contained in an amount of not more than mol%.

Such (a) saturated polyester is substantially linear, which is confirmed by the fact that the saturated polyester is dissolved in o-chlorophenol. The saturated polyester used in the present invention usually has an intrinsic viscosity [η] measured at 25 ° C. in o-chlorophenol of 0.
5 to 1.4 dl / g, preferably 0.5 to 1.0 dl / g,
More preferably, it is desired to be 0.6 to 1.0 dl / g.

The (a) saturated polyester having such an intrinsic viscosity [η] is preferable because it is excellent in melt moldability and draw ironing and moldability, and is also excellent in mechanical strength such as impact resistance.

The (a) saturated polyester resin used in the present invention has a glass transition temperature (Tg) of usually 50 to 120.
It is desirable that the temperature is 60 ° C, preferably 60 to 100 ° C.
This (a) saturated polyester resin may be amorphous or crystalline, and when it is crystalline, its crystal melting temperature (Tm) is usually 210 to 265 ° C., preferably 2
The temperature is 20 to 260 ° C., and the low temperature crystallization temperature (Tc) is usually 130 to 210 ° C., preferably 135 to 205 ° C.

In the present invention, (a) the saturated polyester resin is not particularly limited, but among the above, it is amorphous or almost amorphous because of its excellent adhesiveness to a metal and excellent impact resistance. It is preferable to use a saturated polyester resin that has a property.

In the present invention, the (b) ionomer resin used when forming the resin composition layer [B] is:
Although a conventionally known ionomer resin is widely used, this ionomer resin is an ion in which a part or all of carboxyl groups in a copolymer of ethylene and α, β-unsaturated carboxylic acid is neutralized with a metal cation. It is a natural salt.

As the α, β-unsaturated carboxylic acid,
Unsaturated carboxylic acids having 3 to 8 carbon atoms, specifically acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monomethyl ester and the like can be mentioned.

With such ethylene and unsaturated carboxylic acid
Cations Neutralizing Carboxyl Groups in Copolymers of Polystyrene
Specifically, Na⁺, K⁺, Li⁺, Zn⁺,
Zn ⁺⁺, Mg⁺⁺, Ca⁺⁺, Co⁺⁺, Ni⁺⁺, Mn⁺⁺, P
b⁺⁺, Cu⁺⁺And monovalent divalent metal cations such as
You. In addition, the residual carboxylate not neutralized with metal cations
Some of the silyl groups are esterified with lower alcohols
You may.

The (b) ionomer resin used in the present invention is a metal salt of a copolymer of ethylene and an unsaturated carboxylic acid as described above, but an ethylene / unsaturated carboxylic acid for forming the metal salt is used. The copolymer with is composed of a structural unit derived from ethylene in an amount of 80 to 99 mol%, preferably 8
5 to 98 mol% of the structural unit derived from an unsaturated carboxylic acid (a structural unit having a carboxyl group)
It is contained in an amount of 20 mol%, preferably 2 to 15 mol%.

In the (b) ionomer resin used in the present invention, some or all of the carboxyl groups in the copolymer of ethylene and unsaturated carboxylic acid, specifically 15 to 1
00% of the carboxyl groups are neutralized. This degree of neutralization is preferably 20-80%, more preferably 30-
The composition formed from the (b) ionomer resin having a degree of neutralization of 70% is excellent in melt extrudability.

Specific examples of the (b) ionomer resin include a copolymer of ethylene and an unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid, or an unsaturated monomer such as ethylene and maleic acid or itaconic acid. Examples thereof include ionomer resins in which some or all of the carboxyl groups in the copolymer with a dicarboxylic acid are neutralized with metal ions such as sodium, potassium, lithium, zinc, magnesium and calcium.

Among these, 30 to 30 of the carboxyl groups in the copolymer of ethylene and acrylic acid or methacrylic acid (2 to 15 mol% of the structural unit having a carboxyl group)
It is preferable that 70% is neutralized with a metal such as Na or Za.

It is also possible to use a mixture of a neutralized substance with a metal such as Na and Za and a non-neutralized substance.

As these ionomer resins, commercially available products such as "Himilan" (trade name: manufactured by DuPont Mitsui Polychemical Co., Ltd.) can be used. In the present invention,
[B] The resin composition comprises (a) a saturated polyester resin and (b)
When the total amount of the ionomer resin and the ionomer resin is 100 parts by weight, 75 to 9 of the above (a) saturated polyester resin is used.
9 parts by weight, preferably 80 to 95 parts by weight, 1 to 25 parts by weight of (b) ionomer resin, preferably 20 to 5 parts by weight.
Parts by weight, more preferably 18 to 7 parts by weight.

Such a [B] resin composition has a cold crystallization heat quantity of 27 J / g or less and a melting heat quantity of 30 J / g.
g. The cold crystallization heat (J /
g) is 1 using a differential thermal analyzer (Perkin Elmer-7 type)
It is the amount of heat generated by crystallization observed when measured at a heating rate of 0 ° C./min.

The above-mentioned [B] resin composition can be prepared by a conventionally known method for preparing a resin composition,
Specifically, it is prepared by mixing (a) a saturated polyester resin and (b) an ionomer resin with a tumbler blender, a Henschel mixer, a V-type blender, etc., and then melt-mixing them with an extruder, a kneader Banbury mixer, or the like. can do.

In the present invention, the resin film laminated on the metal plate is composed of two layers of the above [A] crystalline saturated polyester resin layer and [B] resin composition layer, and [B] ] The resin composition layer is laminated so as to be in contact with the metal plate.

The thickness of the resin layer thus laminated is 2
The total number of layers is usually 5 to 500 μm, preferably 10 to 1
00 μm, particularly preferably 20 to 60 μm. Further, these [A] crystalline saturated polyester resin layers and [B]
The film thickness ratio of the two layers to the resin composition layer is preferably [A] layer: [B] layer = 2: 1 to 1: 9.

When the [A] layer / [B] layer exceeds 2,
It may be inferior in impact strength. On the other hand, [A] layer / [B]
If the number of layers is less than 1/9, it may be difficult to continuously laminate the metal plate with a uniform film thickness, and pinholes may occur in the obtained can.

The resin-coated metal plate according to the present invention as described above is manufactured, for example, as follows. (1) A crystalline saturated polyester resin [A] and a resin composition [B] prepared as described above are placed on a metal plate by a two-layer extrusion T-die so that the [B] resin layer contacts the metal plate. Push out at the same time.

(2) A film consisting of the [A] crystalline saturated polyester resin layer and the [B] resin composition layer is formed once, and the [B] resin composition layer is used as the metal plate. Laminate them so that they touch.

(3) Alternatively, the [B] resin composition layer may be formed on the metal plate, and then the [A] crystalline saturated polyester resin layer may be formed on the [B] resin composition layer. When the resin layer is coated on the metal plate as described above, it is preferable that the resin coating extruded in a molten state from the extruder and coated on the metal plate is rapidly cooled.

The resin film thus provided on the metal plate is preferably substantially unoriented and in an amorphous state. Further, when forming the resin coating as described above on the metal plate, if necessary, additives such as a weather resistance stabilizer, a lubricant, a heat stabilizer, and an impact modifier may be contained in each resin layer. Further, these additives may be added after forming a masterbatch composed of each resin and the additive in advance.

Of these, the method (1) of simultaneously extruding with a two-layer extrusion T die is excellent in manufacturing cost, and from the resin-coated metal plate obtained by this method, a drawn and ironed can excellent in pinhole-free quality. Are most easily formed, which is preferable. The method (2) in which the film is once formed and then laminated is more expensive than the method (1), and the resin-coated metal plate obtained may be inferior in the result of the pinhole test. In the method (3), a uniform two-layer structure film having a specific film thickness ratio may not be obtained, resulting in poor adhesion between the [A] layer and the [B] layer.
Foreign matter (dust) may be mixed in.

The resin-coated metal plate according to the present invention has the above-described metal plate, and the [A] crystalline saturated polyester resin layer and the [B] resin composition layer formed on one surface of the metal plate as described above. It has a thickness ratio and a coating film in which the resin composition layer [B] is laminated so as to be in contact with a metal plate, and has excellent impact resistance and excellent moldability, particularly excellent drawing and ironing moldability, and a pin in the film during molding. It is processed uniformly without producing holes. In addition, the resin coating film has excellent adhesion to the metal plate and excellent processing followability during molding, so that a can having an excellent appearance can be obtained.

The resin-coated metal sheet according to the present invention can exhibit excellent characteristics such as drawing and ironing workability by being formed of the specific resin layer as described above.

When the layer [A] is formed of homopolyethylene terephthalate, blister may occur after can making. Further, when the layer [A] is formed of a copolyester containing an isophthalic acid component in an amount of 20 mol%, the punch may not be easily removed during can making, and it may be difficult to continuously manufacture cans. Cans may be inferior in pinhole tests and flavor adsorption characteristics and other evaluations.

When (b) the ionomer resin is used in an amount exceeding 25 parts by weight when preparing the resin composition for forming the [B] layer, the (b) ionomer resin and the (a) polyester resin are homogeneous. It becomes difficult to be mixed with. Therefore, the resin composition containing (b) the ionomer resin in an amount exceeding 25 parts by weight makes it difficult to form a resin layer having a constant thickness on the metal plate due to the generation of lumps and gel. In addition, pinholes may occur during drawing and ironing. Further, the obtained squeezed ironing can has a problem that the flavor adsorption is large. On the other hand, when the layer (B) is formed without using the (b) ionomer resin, the impact strength may be poor and the layer may become brittle.

Further, instead of the resin coating as described above,
The layer [A] is formed of a composition comprising 75 to 100 parts by weight of polyethylene terephthalate or polybutylene terephthalate in which 90 to 100 mol% of the dicarboxylic acid component is terephthalic acid; and an ionomer; 0 to 25 parts by weight, The layer [B] contains 75 to 10 of the dicarboxylic acid component.
Polyethylene terephthalate in which 0 mol is terephthalic acid; 1 to 40 parts by weight and 60 to 10 of the dicarboxylic acid component
Polybutylene terephthalate in which 0 mol% is terephthalic acid; 30 to 85 parts by weight, and ionomer; 10 to 30
When squeezing and ironing a metal plate formed of a composition consisting of parts by weight, pinholes are likely to occur and it is difficult to obtain a practical can, and the obtained can has a very large flavor adsorption and a soft drink. It is difficult to obtain a squeezed ironing can that is suitable for the intended use.

Further, when producing a squeezed ironing can, if a metal plate coated with a composition comprising polyethylene terephthalate, a copolymerized polyester containing terephthalic acid and isophthalic acid as dicarboxylic acid components, and an ionomer is used, Pinholes are easily generated during ironing,
Further, variations in film thickness and crystallinity become large, and it is difficult to stably obtain a drawn and ironed can.

The drawn and ironed can according to the present invention is formed by drawing and ironing the resin-coated metal plate as described above. At this time, when a resin-coated metal plate in which a resin coating is provided on only one surface of the metal plate is used, it is drawn and ironed so that the resin-coated surface faces the inner surface of the can.

In the production of an ironing can drawn from the above-mentioned resin-coated metal plate, if a resin-coated metal plate having resin coatings on both sides is used, the squeezed cover not only on the inner surface of the can but also on the outer surface of the can is coated with the resin. Since an ironing can is obtained, it is possible to omit the coating process on the outer surface of the can that is usually performed after the can is manufactured, and there is no problem at the time of coating such as solvent scattering, and the can manufacturing facility can be significantly reduced. .

As a method for producing a squeezed ironing can (DI can), various known methods can be adopted. As the most general method, it can be manufactured by a one-step or several-step ironing method using an ironing punch.

For example, the drawing and ironing process can be performed under the following conditions. Plank diameter: 100-200 mm Drawing conditions: 1-step drawing ratio 1.1-2.4 2-step drawing ratio 1.1-1.6 Drawing ironing diameter: 3-step ironing 20-100 mmφ Total ironing rate: 20-80% The squeezed ironing can according to the present invention has a two-layer coating consisting of a [A] crystalline saturated polyester resin layer and a [B] resin composition layer on a metal plate, and the [A] crystalline saturated polyester resin layer is the contents of the can. Since it is formed so as to come into contact with, the terpene-based odor is not particularly adsorbed, the flavor property (fragrance retaining property) is excellent, and there are no pinholes in the coating film, and the long-term storage property of the content is excellent.

[0059]

Industrial Applicability The resin-coated metal plate for a drawn and ironed can according to the present invention has excellent adhesion between the resin and the metal plate, excellent drawability and ironing formability, and excellent followability of the resin during molding. It can form a squeezed ironing can with less fish eyes and excellent appearance.

Further, the squeezed ironing can according to the present invention is a can,
It has excellent impact resistance that can withstand impacts during the canning process and during transportation, and retains excellent impact resistance even when heated in processes such as drying, printing, and baking after can manufacturing.

The squeezed ironing can according to the present invention has no pinhole, is excellent in long-term storability of the contents, and is also excellent in storability such as scent and flavor (aroma retention) of the contents.

[0062]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

[0063]

Examples 1 to 8 [A] crystalline saturated polyester resin shown in Table 1 and [B] (a) having a composition shown in Table 1
A resin composition comprising a saturated polyester resin and (b) an ionomer resin (Himilan 1706: Mitsui DuPont Co., Ltd., trade name; excluding Example 8), and Sn plating of 2.8 g / m ² per side is applied on both sides. Using a two-kind two-layer extrusion T die on the Sn plating layer on one side of the applied steel plate (plate thickness 0.245 mm, hardness T-4 equivalent), the [B] layer was formed at the film thickness ratio shown in Table 1. A total film thickness of 30 μm was applied so as to be in contact with the steel plate. The coated steel sheet used is heated, and the steel sheet coated with resin with a T-die has 10 seconds within 10 seconds.
It was rapidly cooled to below 0 ° C.

Table 1 shows the intrinsic viscosity [dl / g] of the crystalline saturated polyester resin [A] and the Tg (glass transition temperature), Tm (melting point) and Tc of the saturated polyester resin (a).
(Low temperature crystallization temperature) is shown.

Tg, Tm and Tc were measured at a temperature rising rate of 10 ° C./min using a differential thermal analyzer (Perkin Elmer-7 type). Tg observed at the time of temperature rise was taken as the temperature at the intersection of the tangents of the peak, and Tc and Tm were taken as the temperature at the peak.

The resin-coated steel sheet at room temperature thus obtained was drawn and ironed under the following molding conditions so that the resin-coated surface was the inner surface of the can, and a drawn and ironed can was manufactured.

<Molding conditions> 1. Resin temperature just before drawing and ironing: normal temperature 2. Plank diameter: 137 mm 3. Aperture conditions: 1-stage aperture ratio 1.6 2-stage aperture ratio 1.3 4. Ironing punch diameter: 3-stage ironing 65.8 mmφ 5. Total ironing rate: 67%

(I) Adhesion Evaluation of Can Inner Surface Coating Resin After squeezing and ironing, the inner surface of the can is washed and then heated in an oven.
The degree of resin peeling at the tip of the can after observing at 10 ° C. for 10 minutes was observed and evaluated. The evaluation criteria are shown in Table 2.

(Ii) Blister evaluation After squeezing and ironing, the inner surface of the can was washed, and the blister (swelling) formed on the bottom of the can after calcination for 10 minutes at 210 ° C. in the oven with the can covered It was observed and evaluated. The evaluation criteria are shown in Table 2.

(Iii) Evaluation of Impact Resistance of Resin Coating A 1.0% saline solution was filled in a drawn and ironed can after coating and baking on the outer surface of the can and retort-treated at 120 ° C. for 30 minutes.
After the treatment, it was cooled to room temperature and dropped from the bottom to an iron plate with an angle of 45 degrees from a height of 30 cm. After dropping, discard the saline solution inside the can and use a little salt solution near the impact part as the cathode.
A current of 6 V was applied with the outer wall of the can as an anode. The current value (mA) flowing at this time was measured. The evaluation criteria are shown in Table 2.

(Iv) Pinhole evaluation or copper sulfate test pinhole evaluation of can inner surface coating resin After squeezing and ironing, the can was baked in an oven at 210 ° C. for 10 minutes and then filled with 1.0% saline solution. A salt solution was used as a cathode, and an outer wall of the can was used as an anode, and a current of 6 V was applied. The current value (mA) flowing at this time was measured. Table 2 shows the evaluation criteria
Shown in

Copper Sulfate Test 20 g / l of sulfuric acid and copper sulfate (C
A chemical plating solution of copper containing 50 g / l of (uSO ₄ .7H ₂ O) was placed and left for 10 minutes to remove the solution and wash with water, and then the deposited copper was observed. If the resin layer on the inner surface of the can has a lack (pinhole), iron is eluted from the lack and copper is displacement plated.

(V) Evaluation of flavor adsorption characteristics The inside surface of the can obtained as described above was washed and washed at 210 ° C.
Dried in an oven for about 2 minutes. Furthermore, the outer surface of the can was painted and baked. 20 in the can thus obtained
A 5% ethanol solution containing ppm limonene was filled and left at 20 ° C. for 10 days. The amount of limonene adsorbed on the film was compared with that of the can (when homo-PET was used on the inner surface) obtained in Comparative Example 1 as shown below as 100.

[0074]

Comparative Example 1 A resin-coated metal plate was obtained in the same manner as in Example 1 except that a film (single layer) made of a crystalline saturated polyester resin as shown in Table 1 was formed with a thickness of 30 μm.

This resin-coated metal plate was made into cans in the same manner as in the example. The obtained cans were tested and evaluated in the same manner as in the examples. Table 3 shows the results.

Table 1 shows the intrinsic viscosity [dl / g], Tg, Tm and Tc of this crystalline saturated polyester resin.

[0077]

Comparative Example 2 A resin-coated metal plate was obtained in the same manner as in Example 1 except that a coating (single layer) made of a saturated polyester resin as shown in Table 1 was formed with a thickness of 30 μm.

This resin-coated metal plate was made into a can in the same manner as in the example. The obtained cans were tested and evaluated in the same manner as in the examples. Table 3 shows the results.

Table 1 shows the intrinsic viscosity [dl / g], Tg, Tm and Tc of this crystalline saturated polyester resin.

[0080]

[Table 1]

* 1) [A] Copolyester resin: The dicarboxylic acid component is 100 mol%. The dicarboxylic acid component other than isophthalic acid is terephthalic acid. * 2) (a) Copolyester resin; the dicarboxylic acid component is 100 mol%.

The dicarboxylic acid component other than isophthalic acid is terephthalic acid. * 3) (a) Copolyester resin; the dihydroxy component is 100 mol%.

CHDM (cyclohexanedimethanol)
The other dihydroxy component is ethylene glycol.

* 4) Homo PET: Mitsui Pet Resin Co., Ltd.
Crystalline polyester made. * 5) [B] resin composition: The total amount of the ionomer resin and the saturated polyester resin is 100 parts by weight.

* 6) Ionomer: High Milan 1707
(Mitsui DuPont Polychemical Co., Ltd. product name)

[0086]

[Table 2]

[0087]

[Table 3]

[0088]

[Comparative Examples 3 to 6] Resin-coated metal plates were obtained in the same manner as in Examples except that a coating film of saturated polyester resin as shown in Table 4 was formed to a thickness of 30 µm. This resin-coated metal plate was made into a can in the same manner as in the example. Table 5 shows the results of the test evaluation of the obtained cans in the same manner as in the examples.

[0089]

COMPARATIVE EXAMPLE 7 Polyethylene terephthalate (PET) (IV = 0.69) as shown in Table 4 was melt extruded by a conventional method, and biaxially stretched to 3.5 times in the longitudinal direction and 3.7 times in the lateral direction, and 2
PET-BO (2
An axially stretched PET film was prepared. PET-obtained
The [B] layer shown in Table 4 was extrusion-laminated to a thickness of 14 μm on the BO coating to form a two-layer film. On a steel plate similar to that of the example, the [B] layer was adhered to the steel plate at a steel plate temperature of 220 ° C. and water-cooled to prepare a resin-coated metal plate. This resin-coated metal plate was made into a can in the same manner as in the example. Table 5 shows the results of the test evaluation of the obtained cans in the same manner as in the examples.

[0090]

[Table 4]

[0091]

[Table 5]

[0092]

Examples 9 to 16 Except that a coating film made of a saturated polyester resin as shown in Table 6 was formed to a thickness of 30 μm,
A resin-coated metal plate was obtained in the same manner as in Example 1. This resin-coated metal plate was made into a can in the same manner as in Example 1. Table 8 shows the test evaluation results of the obtained cans in the same manner as in Example 1.

[0093]

Comparative Examples 8 to 14 Except that a coating film made of a saturated polyester resin as shown in Table 7 was formed to a thickness of 30 μm.
A resin-coated metal plate was obtained in the same manner as in Example 1. This resin-coated metal plate was made into a can in the same manner as in Example 1. Table 8 shows the test evaluation results of the obtained cans in the same manner as in Example 1.

[0094]

[Table 6]

[0095]

[Table 7]

In Tables 6 and 7, * 5) [B] resin composition: The total amount of the ionomer resin and the saturated polyester resin is 100 parts by weight.

[Table 8]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takayuki Hiraoka Takayuki Hiraoka 6-1-2 Waki, Waki-cho, Kuga-gun, Yamaguchi Mitsui Petrochemical Industry Co., Ltd. (72) Koji Shinmi Kuga-gun, Yamaguchi Waki-cho 6-1-2 Waki Mitsui Petrochemical Industry Co., Ltd.

Claims (5)

(57) [Claims] 1. A metal plate and a resin film provided on one or both sides of the metal plate, wherein the resin film is derived from [A] dicarboxylic acid and dihydroxy compound and contains 100 mol of dicarboxylic acid component. %, The dicarboxylic acid component is a crystalline saturated polyester resin layer consisting of 99-85 mol% terephthalic acid and 1-15 mol% isophthalic acid, and [B] (a) saturated polyester resin: 75-99 wt. Department,
And (b) an ionomer resin: two layers including a resin composition layer consisting of 25 to 1 part by weight, and [B] the resin composition layer is laminated so as to be in contact with the metal plate. Resin coated metal plate for squeezing and ironing cans. 2. A crystalline saturated polyester resin layer [A],
The [B] resin composition layer has a film thickness ratio of [A] layer: [B] layer = 2: 1 to 1: 9. Metal plate. 3. A resin-coated metal plate for a drawn and ironed can according to claim 1, wherein the resin coating provided on the metal plate is substantially unoriented and in an amorphous state. 4. The resin-coated metal plate for a drawn and ironing can according to claim 1, wherein the metal plate is a steel plate or an aluminum plate. 5. A drawn and ironed can formed by drawing and ironing the resin-coated metal sheet according to claim 1.