JPH09122799A - Seamless can, its production and laminate plate used in production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seamless can with excellent machinability and contents resistance and a laminate material for producing it by preventing the generation of anisotropic flaw. SOLUTION: A polyester A of a circular shape part to be a bottom part of a seamless can is made as polyester of the biaxial orientation Rx 2.5 to 20, which is defined in the equation, Rx=IA/IB. In here, IA is the diffraction strength on the diffraction face being about 0.34nm in face interval and parallel to the front face of polyester, and IB is the diffraction strength on the diffraction face being about 0.39nm in face interval and parallel to the front face of polyester. Further, the other part polyester B is a laminate plate having the biaxial orientation being satisfied with two equation. RxBN<=0.95Rx and (RxBN-RxBS)<=1800×(RxBN)<-5> . In here, RxBN is the biaxial orientation of the part of largest orientation on the can drum corresponding part, RxBS is the biaxial orientation of the part of smallest orientation of the cam drum corresponding part being separated to the circumference direction away from the largest orientation part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seamless can formed from a laminate material of a metal substrate and a polyester film and a laminate material for producing the same, and more particularly to a canning portion and a neck portion of the can. The present invention relates to a seamless can that is excellent in workability and content resistance and that prevents anisotropic defects such as deterioration in workability, deterioration of coating, corrosion and the like, and a laminate material for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a side seamless can (side seamless can), a metal material such as an aluminum plate, a tin plate or a tin-free steel plate is provided by at least one step between a drawing die and a punch. By drawing, a cup consisting of a body part having no side seam and a bottom part connected to the body part without a seam is formed, and then, if desired, an ironing punch and a die are formed on the body part. It is known that the body of the container is thinned by ironing between them.
Also, instead of ironing, it is already known to bend and extend at the curvature corner portion of the redrawing die to thin the side wall portion (Japanese Patent Publication No. 56-501442).

[0003] As an organic coating method for a side seamless can, there is known a method of applying an organic paint to a molded can which is generally widely used, and a method of laminating a resin film on a metal material before molding in advance. It has been
No. 80 describes that a laminate obtained by laminating a polyester film derived from terephthalic acid and tetramethylene glycol on a metal material is used. It is also known to use a coated metal plate of vinyl organosol, epoxy, phenolics, polyester, acrylic, etc., when producing a redrawn can by bending and stretching.

JP-A-3-101930 discloses a laminate comprising a metal plate, a polyester film layer mainly composed of ethylene terephthalate units, and optionally an adhesive primer layer interposed between the metal plate and the polyester film layer. become, the polyester film layer, wherein Rx = I _a / I _B formula, I _a is parallel to the polyester film surface, about the plane spacing 0.34nm (CuKαX ray diffraction angle of from 24 ° 2
X-ray diffraction intensity by the diffraction surface of 8 °), I _B is approximately parallel to the plane spacing the polyester film surface 0.39nmCuKα
X by a diffraction surface having an X-ray diffraction angle of 21.5 ° to 24 °)
A diaphragm comprising a film layer having an X-ray diffraction intensity ratio defined by X-ray diffraction intensity of 0.5 to 15 and an anisotropy index of in-plane crystal orientation of 30 or less. There is described a coated metal plate for cans and a thinned squeezed can in which the side wall of a can body is bent and stretched to reduce the thickness thereof.

Japanese Patent Laid-Open No. 7-22 proposed by the present inventors
In Japanese Patent No. 3645, the polyester (A) in the portion corresponding to the bottom of the container is represented by the formula Rx = I _A / I _B where I _A is a surface spacing parallel to the polyester film surface of the can bottom of about 0.34 nm (CuKα X-ray diffraction). It is the diffraction intensity by the diffractive surface having a bending angle of 24 ° to 28 °, and I _B is a surface interval parallel to the polyester film surface of the bottom of the can of about 0.39 nm (CuKα X-ray diffraction angle of 21.5 ° to 2 °).
It is a polyester having a biaxial orientation degree (Rx) of 2.5 to 20, which is defined by the diffraction intensity by a diffraction surface of 4 °), and the polyester (B) in the portion corresponding to the upper part of the container body is the polyester (B). A laminated plate which is a polyester having a biaxial orientation degree (Rx) lower than the biaxial orientation degree value of A) by at least 5% is used, and the polyester in the container body has the following formula: 0.55 <cos ² φ <1 -exp [-0.45I _A / I _B -1.
It is described that a seamless can having a uniaxial orientation degree (cos ² φ) satisfying 1 ε + 0.53] is manufactured.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The proposal found in Japanese Patent No. 645 discloses that the degree of biaxial orientation of the polyester layer at the bottom of the can is set relatively high, and the degree of biaxial orientation of the polyester layer at the body of the can is set relatively low, and the polyester layer of the body is By keeping the uniaxial orientation degree within a certain range, both the can body and the can bottom are excellent in content resistance and flavor retention, and the can body has excellent adhesion and workability. In addition, it is recognized that the bottom of the can has a significant meaning in that it provides a seamless can having excellent impact resistance (dent resistance).
It was found that there are still points to be improved in terms of workability and resistance to contents.

That is, even in the case of the can body orientation relaxation type seamless can described above, when the wall thickness is reduced to a high degree or the diameter of the neck part is reduced, or a content having a stronger metal corrosive property is filled. In this case, it has been found that defects such as insufficient workability, coating defects and metal corrosion occur at the tightening portion, the neck portion and the like, and at a limited position in the circumferential direction.

The occurrence of the above defects in a limited portion in the circumferential direction is observed only in a seamless can using a laminate material in which the can bottom has a high degree of biaxial orientation and the body of the can has a degree of low biaxial orientation. This is a so-called isotropic defect in which a coating defect or corrosion in a conventional seamless can is observed over almost the entire circumferential direction at a portion of a certain height, but it should also be called an anisotropic defect. It is a thing.

The thickness of the wall of the seamless can that has been put into practical use is about 35% at the most, but it is required to reduce the cost of the metal material and reduce the weight of the can. It is highly desirable to have a degree of 40% or more. As described above, it was also found that the generation of the anisotropic defect becomes more remarkable by reducing the thickness of the can body.

Further, it is desired to increase the degree of diameter reduction by neck-in processing from the viewpoint of the aesthetics of seamless cans and the cost of the lid, but the degree of diameter reduction by neck-in is increased. It was also found that in this case, the occurrence of anisotropic defects was remarkable.

Therefore, an object of the present invention is to provide a seamless can using a metal-polyester laminate material in which the can bottom has a high degree of biaxial orientation and the body of the can has a low degree of biaxial orientation.
It is an object of the present invention to provide a seamless can having excellent processability and content resistance, which prevents the occurrence of the above-mentioned anisotropic defect, and a laminate material for producing the same.

Another object of the present invention is to effectively suppress the occurrence of anisotropic defects even when the degree of thinning of the side wall portion is increased and when the diameter of the neck portion is increased. We can provide seamless cans.

[0013]

According to the present invention, there is provided a laminate plate for producing a seamless can comprising a metal and a polyester film, wherein the polyester (A) in the circular portion to be the bottom of the seamless can has the formula ( _{1) Rx = I a / I} B ... (1) formula I _a is a diffraction by the diffraction surface of the polyester film surface on a plane parallel spacing about 0.34 nm (28 ° from CuKαX ray diffraction angle of 24 °) of the can bottom is the intensity, I _B is 2 the can bottom of the polyester film surface on a plane parallel spacing about 0.39nm (CuKαX ray diffraction angle is from 21.5 °
4 °) is a polyester having a biaxial orientation degree (Rx) of 2.5 to 20 defined by the diffraction intensity by a diffractive surface, and the polyester (B) in the other portion corresponding to the can body is Rx _BM ≦ 0.95 Rx (2) and (Rx _BM −Rx _Bm ) ≦ 1800 × (Rx _BM ) ⁻⁵ (3) In the formula, Rx _BM is a can body. Rx _Bm is the degree of biaxial orientation of the maximum orientation portion in the corresponding portion, Rx _Bm is the degree of orientation of the minimum orientation portion of the portion corresponding to the can body portion circumferentially separated from the maximum orientation portion, Rx _Bm
There is provided a laminate having a biaxial orientation degree satisfying that x has the above-mentioned meaning.

[0014] polyester layer (B) is the following formula _{(4) (Rx BM -Rx Bm} ) ≦ 240 × (Rx BM) -4 ... (4) particularly preferably has a biaxial orientation degree which satisfies.

According to the present invention, a laminate of a metal and a polyester film can be used as H / D (H: height,
D: In the seamless can formed by molded into a cup shape as the bottom diameter) ratio is 1.5 or more, the polyester (A) has the formula the can bottom _{(1) Rx = I A /} I B ... (1) Equation medium I _a is a diffraction intensity by a diffraction plane approximately parallel to the plane spacing the polyester film surface of the can bottom 0.34 nm (28 ° CuKαX ray diffraction angle of from 24 °), I _B is the polyester film surface of the can bottom Plane spacing about 0.39 nm (CuKα X-ray diffraction angle from 21.5 ° to 2
4 °) is a polyester layer having a biaxial orientation degree (Rx) of 2.5 to 20 defined by the diffraction intensity by a diffractive surface, and the polyester layer (B) of the body of the can is directly below the tightening portion. and in the most uniaxially oriented by being part of the circumferential direction, in the following formulas ^{(5) 0.55 <cos 2 φ} M <1-exp _{[-0.45I a / I B -1.1 ε +} 0.53 ] ... (5) formula, cos ² φ _M is an index representing the degree of maximum uniaxial orientation of the polyester film in the can body measuring section, I _A and I _B have the above-mentioned meanings, and ε is the processing of the laminate material in the can body measuring section. It is a considerable strain. In the minimum uniaxial orientation part that has a uniaxial orientation degree satisfying the above condition and is separated from the maximum uniaxial orientation degree part in the circumferential direction, formula (6) (cos ² φ _M −cos ² φ _m ) ≦ 25 × 10 ⁻⁴ × (cos ² φ _M ) ^-40 (6) In the formula, cos ² φ _m is an index representing the degree of uniaxial orientation in the minimum uniaxial orientation portion of the can body polyester layer, and cos
² phi _M is seamless can, characterized in that it comprises a monoaxial orientation degree which satisfies, have the meanings described above is provided.

[0016] The following formula can body is compared to the can bottom (7) Rr = ((t 0 -t w) / t 0) × 100 ... (7) In the formula, t ₀ is the thickness of the can bottom , T _W is the thickness of the body of the can, and is preferably thinned so that the reduction rate of the thickness is defined as 15 to 80%.

The winding portion is connected to the body of the can through a neck portion, and the neck portion has the following formula (8) R = ((D-D ₁ ) / D) × 100 (8) The diameter reduction ratio defined by D is the inner diameter of the can body portion and D ₁ is the inner diameter of the neck portion is preferably 60 to 95%.

According to the present invention, the laminate plate is further squeezed and redrawn so that the H / D (H: height, D: bottom diameter) ratio is 1.5 or more, and at least the final stage. In a deep drawing, a method for producing a seamless can is provided, which comprises thinning the cup body by bending and stretching or ironing.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION In the production of a seamless can according to the present invention, a laminated plate formed by heat-bonding a polyester film to a metal substrate is drawn and redrawn, and the cup body is bent and stretched at least in the final deep drawing. Alternatively, although the thickness is reduced by ironing, the polyester (A) in the portion corresponding to the bottom of the container has a biaxial orientation and the polyester in the portion corresponding to the body of the container is used as the laminated plate as in the conventional example. It is basically important to use the one in which the orientation degree distribution is obtained so that (B) has a lower degree of biaxial orientation degree than the polyester (A).

The metal for the seamless can produced according to the invention - polyester laminate plate, a polyester of the circular portion to a seamless can bottom (A) has the formula _{(1) Rx = I A /} I B ... (1) In formula I _a is a diffraction intensity by a diffraction plane approximately parallel to the plane spacing the polyester film surface of the can bottom 0.34 nm (28 ° CuKαX ray diffraction angle of from 24 °), I _B is parallel to the polyester film surface of the can bottom Surface spacing of about 0.39 nm (CuKα X-ray diffraction angle from 21.5 ° to 2
4 °) is a polyester having a biaxial orientation degree (Rx) of 2.5 to 20 defined by the diffraction intensity by a diffractive surface, and the polyester (B) in the other portion corresponding to the can body is Rx _BM ≦ 0.95Rx (2) In the formula, Rx _BM is the biaxial orientation degree of the maximum orientation portion in the can body portion corresponding portion, and Rx has the above-mentioned meaning. It has the maximum degree of biaxial orientation (Rx _BM ) represented by, but the distribution of the degree of biaxial orientation of the polyester in the portion corresponding to the can body is expressed by the following formula (3) (Rx _BM −Rx _Bm ) ≦ 1800 × (Rx _BM ) ⁻⁵ (3) In the formula, Rx _BM is the degree of biaxial orientation of the maximum orientation portion in the portion corresponding to the can body portion, and Rx _Bm is the can body portion circumferentially separated from the maximum orientation portion. Is the degree of orientation of the minimum orientation part of the part, R
It is a remarkable feature that x is defined so as to satisfy the above-mentioned meaning, whereby the above-mentioned anisotropic defects are prevented from occurring during draw-redraw forming or further ironing forming, and a seamless can is formed. It is possible to improve the workability and content resistance of the.

When the polyester layer (B) has a degree of biaxial orientation satisfying the following formula (4) (Rx _BM -Rx _Bm ) ≤ 240 x (Rx _BM ) ^-4 (4), a high degree of side wall is obtained. Even when the thickness of the part is reduced and the diameter of the neck part is reduced to a high degree, the occurrence of anisotropic defects can be more effectively prevented.

Further, by using the above-mentioned laminate material, the distribution of the uniaxial orientation degree of the polyester layer (B) of the can body is expressed by the following formula in the portion immediately below the tightening portion and in the most uniaxial orientation in the circumferential direction. (5) 0.55 <the maximum uniaxial orientation of cos ² φ _M <1-exp _{[-0.45I a / I B -1.1 ε +} 0.53 ] ... (5) where, cos ² φ _M is a polyester film of a can body measuring portion Is an index representing the degree of the above, I _A and I _B have the meanings described above, and ε is the equivalent strain due to the processing of the laminate material in the can body measuring section. In the minimum uniaxial orientation part that has a uniaxial orientation degree satisfying the above condition and is separated from the maximum uniaxial orientation degree part in the circumferential direction, formula (6) (cos ² φ _M −cos ² φ _m ) ≦ 25 × 10 ⁻⁴ × (cos ² φ _M ) ^-40 (6) In the formula, cos ² φ _m is an index representing the degree of uniaxial orientation in the minimum uniaxial orientation portion of the can body polyester layer, and cos
² phi _M can be made to have a uniaxial orientation degree which satisfies, have the meanings described above, thereby preventing the occurrence of anisotropy defects seamless can, the processability and content resistance of seamless can It can be significantly improved.

FIG. 1 showing a laminated plate used in the present invention.
(Plan view), FIG. 2 (a) (enlarged sectional view), FIG. 2 (b)
In (an enlarged cross-sectional view of another example), a blank 1 used for deep drawing is made of a laminate of a metal substrate 2 and an inner layer 3 and an outer layer 4 of a polyester film heat-bonded thereto (FIG. 2 (a)). ), (B)), the blank 1 has a portion 5 formed on the bottom of the container and a portion 6 formed on the outer periphery thereof on the body of the container as shown in FIG.
There is.

In the present invention, first, the portion 5 corresponding to the bottom of the container is formed.
The polyester film (A) is maintained in a highly biaxially oriented state, while the polyester body (B) of the container body portion 6 is maintained in a low biaxially oriented state. Hold it.

As a result, during deep drawing and bending, stretching and thinning, the biaxial orientation of polyester is relaxed in the container body, so that tensile deformation (flow) in the can axis direction and compression in the can circumferential direction are performed. Deformation (flow) is smoothly performed without breakage of the film layer or generation of pinholes or cracks, and thinning by bending and stretching or ironing is easily performed, and even when the molding is completed, the polyester film The layer is expected to have excellent adhesion to the metal substrate and to withstand subsequent processing such as neck-in processing, bead processing, flanging processing and winding processing.

On the other hand, since the highly biaxially oriented state of polyester is maintained at the bottom of the container, this film coating retains excellent impact resistance, and even when denting is applied, peeling, breakage and cracks occur. , Giving the advantage of not generating pinholes. In addition, since the bottom film maintains the biaxial orientation state, it has excellent barrier properties against corrosive components such as various ions, and has a low tendency to adsorb the flavor component of the content, and has a low content resistance. Gives the advantage of being better. Furthermore, since the polyester at the bottom of the container is biaxially oriented, the polyester film is thermally crystallized (heat-filled or hot-sterilized) during heat treatment (for example, drying of printing ink) in a can-making process or heat treatment after canning (hot filling or heat sterilization). Lamella formation), and excellent toughness and adhesion are maintained.

Although the biaxial orientation of the polyester is relaxed in the body-corresponding portion of the laminate blank used in the present invention, the polyester in this portion is drawn by drawing and redrawing and then bending and stretching and ironing. A uniaxial orientation associated with processing is imparted. Since this uniaxial orientation is useful for the barrier property against the corrosive components in the polyester film and for preventing the content flavor from being adsorbed, it is expected that the content resistance of the body of the can will be improved as a result.

However, as already pointed out, in the can body orientation relaxation type seamless can described above, the workability is deteriorated at the can body portion such as the winding portion or the neck portion and at a limited position in the circumferential direction. However, defects such as coating defects and metal corrosion, that is, anisotropic defects occur.

As a result of investigating the cause of this, the inventors of the present invention have found that, in a laminated seamless can having anisotropic defects, the values of the uniaxial orientation of the polyester in the can axis direction are different in the circumferential direction. It was found that anisotropic defects were generated in the portions with a high degree of orientation. Furthermore, as a result of examining the cause of the distribution of the uniaxial orientation degree,
It was found that this distribution was due to the distribution of the residual biaxial orientation degree of polyester in the part of the laminate to be the can body.

That is, in the above-mentioned biaxially oriented distribution type laminated plate, when the metal plate and the polyester film are heat-bonded, the part corresponding to the bottom of the container is heat-bonded at a relatively low temperature to relax the biaxial orientation. And the temperature corresponding to the container body is heat-bonded at a relatively high temperature to increase the degree of relaxation of the biaxial orientation. Is performed by bringing a heating roll having a temperature distribution pattern into contact with the metal plate, but when the heating roll comes into contact with the metal plate, the metal plate portion serving as the body portion is thermally deformed and wavy. This causes a problem that the temperature pattern is not accurately transmitted to the metal plate portion serving as the body. In order to further improve the dent resistance of the bottom of the can, this waviness is more remarkable as the temperature becomes lower and the temperature difference between the can-cylinder corresponding part becomes larger.

For this reason, in the portion of the laminated plate that should become the can body, the portion where the orientation is normally relaxed by contact with the heating roll, and the portion where it floats from the heating roll and the orientation is not normally relaxed. The difference in the biaxial orientation with the broken portion will occur. Further, due to the difference in the biaxial orientation, even in the same container at the same height, a large difference occurs in the degree of uniaxial orientation depending on the circumferential position.

The inventors of the present invention effectively control the occurrence of anisotropic defects by controlling the distribution of the degree of uniaxial orientation of polyester in the vicinity of the winding portion of the can body of a seamless can within the range satisfying the above expression (6). I was found to be restrained by.

For that purpose, the distribution of the degree of biaxial orientation of polyester in the can body portion corresponding to the laminate material used is in the range satisfying the above expression (3), particularly, the above expression (4).
It was found that it should be controlled within the range that satisfies.

In this control, the metal plate is brought into contact with a heating roll in which the portion corresponding to the bottom of the can is kept at a relatively low temperature and the portion corresponding to the body of the can is kept at a relatively high temperature. When a pattern is formed and then the metal plate and the biaxially stretched polyester film are bonded and heat-bonded,
A metal plate and a heating roll are brought into contact with each other under conditions where thermal deformation of the metal plate is prevented, and a temperature pattern is transferred.
For example, it can be achieved by arranging at least one nip roll for sandwiching the metal plate with the heating roll at a position where the metal plate leaves the heating roll or a position in the vicinity of the upstream side of the heating roll to transfer the temperature pattern. I also found

See examples below. In Table 3, the value on the left side and the value on the right side of the equation (6) are described.
When the value on the left side is larger than the value on the right side (Examples 2, 3 and 4), anisotropic defects occur or breakage occurs during molding, whereas the value on the left side is greater than the value on the right side. It is clear that when the value is made smaller, it is possible to prevent breakage at the time of molding and prevent the occurrence of anisotropic defects. Further, for that purpose, it is also understood that the degree of biaxial orientation of the polyester layer of the laminate material to be used should be within the range that satisfies the above formula (3), particularly the formula (4).

In the present invention, the portion corresponding to the can bottom portion of the laminate material does not mean that this portion exactly corresponds to the container bottom portion, but means that the container bottom portion is formed from this bottom portion corresponding portion. It does not matter if the lower part of the container body is formed from the bottom corresponding part of the blank.

[0037] [biaxially oriented degree] First, biaxial orientation degree of a polyester film (Rx) is represented by the formula _{(1) Rx = I A /} I B ... (1). Here, I _A and I _B is determined by X-ray diffraction as described above, I _A is a diffraction intensity at a plane index (100), I _B is the diffraction intensity at a plane index (-110), and more particularly Is determined as follows.

Method of measuring I _A / I _B : A measurement sample is sampled from the bottom of the container. The measurement is performed as follows using an X-ray diffractometer. As measurement conditions, the X-ray tube (target) is copper (wavelength λ = 0.1542 nm)
The tube voltage and tube current are about 30KV-100mA, and the surface spacing is about 0.39nm (2θ is around 22.5 °).
Diffraction surface and surface spacing of about 0.34 nm (2θ is around 26 °)
In order to be able to separate two diffraction peaks of the diffraction surface of, the slit width is selected to be a light receiving slit whose angle is 0.1 ° or less, and the incident angle and the reflection angle of X-ray are θ with respect to the diffraction angle 2θ, The sample was attached so that the incident X-ray and the diffracted X-ray were symmetrical with respect to the normal to the film surface, and the diffraction angle 2 was maintained while keeping the incident angle θ and the reflection angle θ always equal.
The θ is scanned for 20 to 30 °, and the X-ray diffraction spectrum is measured. An example of the measurement is shown in FIG.

The surface spacing is about 0.39 nm (2θ is 22.5 °
Diffraction) of the diffraction plane and a plane spacing of about 0.34 nm (2θ
There 26 ° around the integrated intensity of each of the diffraction of the diffractive surface of) (peak area) I _B, obtains the I _A, to calculate the value of the intensity ratio I _A / I _B. Integrated intensity of I _A and I _B, as shown, each 2 [Theta] = 24 and 28 °, and knot background by a straight line at the intensity of each of the 2 [Theta] = 21.5 and 24 °, minus background The intensity is indicated by the shaded area in the figure.

In the present invention, the polyester film at the bottom of the can has a biaxial orientation degree (Rx) of 2.5 to 20, particularly 2.8 to 20. The degree of biaxial orientation is important with respect to the dent resistance and the content resistance of the bottom, and if it is lower than the above range, the dent resistance and the content of the bottom are reduced.
On the other hand, if the degree of biaxial orientation exceeds the above range, the adhesion to the metal substrate is reduced, and neither is preferable.

On the other hand, the maximum degree of biaxial orientation Rx in the body of the can
_BM is 95, which is the degree of biaxial orientation Rx of polyester at the bottom of the can.
It has been pointed out that the moldability into a seamless can is deteriorated when the ratio exceeds%, and the maximum degree of biaxial orientation Rx
It has already been pointed out that if the difference between _BM and the minimum degree of biaxial orientation Rx _Bm deviates from the range (3), anisotropic defects are likely to occur.

[Uniaxial Orientation] On the other hand, the uniaxial orientation cos ² φ of the can body polyester film is expressed by the following formula (9).

(Equation 1) Here, I (φ) is an X-ray diffraction intensity by a diffractive surface (plane index (−105)) having a plane interval of about 0.21 nm (CuKα X-ray diffraction angle of 41 ° to 45 °) perpendicular to the surface of the polyester film at an angle φ. Φ is represented by a β scan angle of X-ray diffraction up to −90 °, where the angle considering the structural inclination between the diffractive surface normal vector and the polyester fiber axis with respect to the can height direction is zero. It is represented by a value.

The uniaxial orientation degree index cos ² φ is calculated from the above equation (9), and more specifically, it is obtained by the following method.

◇ Measurement method of degree of uniaxial orientation: ・ Device: X-ray diffractometer, Cu is a target, ball figure attachment ・ Measurement method: film permeation method isolated from the can body of the final can (with 50% diluted hydrochloric acid), α = 0 °, β scan (β =
90 °: Axial direction) 2θ = 43 ° → (−105) surface: Almost right angle to fiber axis ・ Data processing: β = 82 ° → φ = 0 ° (8 ° is the deviation between the surface and the axis)

FIG. 4 is a graph showing an example of the relationship between the β scan angle and the diffraction intensity for the can body polyester film, and FIG.
is a graph showing the relationship between s ² phi and height.

Cos ² φ is 1 when the orientation is a perfect uniaxial orientation in the height direction, and 1/2 when the orientation is random.
And 0 if the orientation is in the circumferential direction of the can (although it cannot be a drawn can).

[0047] In the seamless can of the present invention is directly below seaming portion, the maximum uniaxial orientation degree cos ² phi _M is strain corresponds due to processing at the site of the biaxially orientation degree I _A / I _B and the can body of the can bottom Polyester In relation to ε, it must be within a range that satisfies the inequality (5), and the difference between the maximum uniaxial orientation degree cos ² φ _M and the minimum uniaxial orientation degree cos ² φ _m satisfies the inequality (6). Must be in range.

On the other hand, the equivalent strain ε due to processing is the equivalent strain due to processing from the blank (raw plate) to the can body,
It is calculated from the plate thickness strain εt, the height direction strain εφ, and the circumferential direction strain εθ. The calculation method is as follows. ◇ Equivalent strain due to processing: Calculation method of ε: Equivalent strain ε
Is calculated from the plate thickness strain εt, the height method strain εφ, and the circumferential strain εθ using the equation (10).

(Equation 2) Is calculated as a dimensionless value.

The equivalent strain due to this processing is shown in the explanatory diagram of strain calculation (FIG. 6) in the portion of the peripheral length w ₀ , the radial unit length l ₀ and the thickness t ₀ of the raw plate at an arbitrary diameter position d _n . Assuming that the shape of the height h _n from the bottom of the can body is changed to the shape of the circumference w, the height l and the thickness t, the following is obtained. Plate thickness strain εt = ln (t / t ₀ ) Height (radial) direction strain εφ = ln (l / l ₀ ) Circumferential strain εθ = ln (w / w ₀ ) where εt + εφ + εθ = 0

(Equation 3) The diameter d _n when V _n is a blank plate is d _n = V _n × [4 / (πt ₀ )] Therefore, w ₀ = πd _n = 4 V _n / t ₀ εφ _n =-(εt _n + εθ _n ) Deep drawing In a can, the higher the position in the body of the can, the higher the degree of processing, and the value of ε naturally increases accordingly.

The maximum degree of uniaxial orientation of polyester in the barrel of the can co
When s ² φ _M is equal to the right side of equation (5), the film may break during molding, or even if it can be molded, peeling of the film or occurrence of microcrack pinholes, etc. While the corrosion resistance is deteriorated, by suppressing the maximum degree of uniaxial orientation of the polyester in the can body so as to satisfy the formula (5), the above-mentioned defects can be solved.

In the formula (5), the maximum degree of uniaxial orientation c
The reason that os ² φ _M is specified to be larger than 0.55 is that the uniaxial orientation of the polyester in the can body can improve the content resistance.

Further, according to FIG. 5, it can be seen that the uniaxial orientation degree cos ² φ increases as the equivalent strain ε due to processing increases, but according to the present invention, the average Rx of the portions corresponding to the can body is the same. Also has a small R _XM , resulting in cos
² φ _M is small, so ε can be increased. Therefore, the thinning ratio of about 35% at most, which was possible in the past, is 40% or more,
In particular, it enables thinning and deep drawing down to 60%, which makes it possible to reduce the material cost and the weight of the container.

In the present invention, the maximum degree of uniaxial orientation cos
^Twoφ_MAnd minimum uniaxial orientation degree cos^Twoφ _mAnd the difference is
It is important to satisfy (6)
As already mentioned, from equation (6), the maximum uniaxial
Direction cos^Twoφ_MIs larger, the maximum allowable
Axial orientation degree cos^Twoφ_MAnd minimum uniaxial orientation degree cos^Twoφ_mWhen
It should be understood that the difference between the two is small.

[Seamless can] In FIG. 7 showing an example of the seamless can of the present invention, the seamless can 10 is deep-drawn (drawing-redrawing) of the above-mentioned coated metal plate, or bending / stretching and ironing at the time of redrawing. It is formed by reducing the wall thickness and is composed of a bottom portion 11 and a body side wall portion 12. A flange portion 14 is formed at an upper end of the side wall portion 12 via a neck portion 13 as desired. In this can 10, the side wall 12 is thinner than the bottom 11 by bending and stretching.

The sectional structure of the side wall portion 12 is similar to the sectional structure of the laminated plate shown in FIG. 2 (a). The side wall portion 12 is composed of the metal base 2 and the polyester inner surface coating 3 provided on the surface thereof and the base. The outer surface coating 4 made of polyester is provided on the other surface. 2B showing another example of the cross-sectional structure, the cross-sectional structure is the same as that of FIG. 2A, but between the metal surface and the inner coating 3, and between the metal surface and the outer coating 4. Between the adhesive layers 15a,
The structure is different in that 15b is interposed. In any of these cases, the sectional structure of the bottom portion 11 is similar to that of the side wall portion 12.

[Metallic Material] In the present invention, various surface-treated steel plates and light metal plates such as aluminum are used as the metal plate. As the surface-treated steel sheet, a cold-rolled steel sheet is annealed and then secondary cold-rolled, zinc-plated, tin-plated, nickel-plated,
It is possible to use one or two or more types of surface treatment such as electrolytic chromic acid treatment and chromic acid treatment. An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet,
In particular, it is provided with a metal chromium layer of 10 to 200 mg / m ² and a chromium oxide layer of 1 to 50 mg / m ² (calculated as metal chromium), which is a combination of coating film adhesion and corrosion resistance. Is excellent. Other examples of surface-treated steel sheet are
A hard tin plate having a tin plating amount of 0.6 to 11.2 g / m ² . This tin plate, in terms of metal chromium,
Chromic acid treatment or chromic acid / phosphoric acid treatment is preferably performed so that the amount of chromium is 1 to 30 mg / m ² . As still 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. An aluminum alloy plate excellent in corrosion resistance and workability has a Mn: 0.
2 to 1.5% by weight, Mg: 0.8 to 5% by weight, Z
n: 0.25 to 0.3% by weight, Cu: 0.16 to 0.26% by weight, with the balance being Al. It is desirable that these light metal plates have also been subjected to a chromic acid treatment or a chromic / phosphoric acid treatment such that the chromium amount becomes 20 to 300 mg / m ^{2 in} terms of chromium metal.

The base plate thickness of the metal plate, that is, the thickness (t _B ) of the bottom of the can varies depending on the kind of metal, the use or size of the container, but generally has a thickness of 0.10 to 0.50 mm. Of these, the surface-treated steel plate preferably has a thickness of 0.10 to 0.30 mm, and the light metal plate has a thickness of 0.15 to 0.40 mm.

[Polyester Film] The laminated plate used in the present invention can be obtained by laminating a biaxially oriented polyester film on the above-mentioned metal substrate by thermal bonding. This film is a biaxial film represented by I _A / I _B. The degree of orientation (Rx) is preferably 2.5 or more, particularly 3 or more.
This film is formed by forming a polyester mainly composed of ethylene terephthalate units into a film by a T-die method or an inflation film forming method, and stretching this film at a stretching temperature.
It is manufactured by sequentially or simultaneously biaxially stretching and heat-setting the stretched film.

As the raw material polyester, polyethylene terephthalate itself can be used under limited conditions. However, in terms of relaxation of the orientation of the film corresponding to the body of the can, polyester in terms of thermal adhesion and resistance to contents. It is advisable to introduce copolymerized ester units other than ethylene terephthalate therein. In the present invention, it is particularly preferable to use a biaxially stretched film of a copolymerized polyester mainly composed of ethylene terephthalate units and containing a small amount of other ester units and having a melting point (peak temperature of melting endotherm in differential thermal analysis) of 210 to 252 ° C. . The melting point of homopolyethylene terephthalate is generally from 255 to 265 ° C.

Generally, 70 mol% or more, particularly 75 mol% or more, of the dibasic acid component in the copolyester is composed of a terephthalic acid component, and 70 mol% or more, particularly 75 mol% or more of the diol component is composed of ethylene glycol. It is preferable that 1 to 30 mol%, particularly 5 to 25% of the dibasic acid component and / or diol component is composed of a dibasic acid component other than terephthalic acid and / or a diol component other than ethylene glycol.

Dibasic acids other than terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalenedicarboxylic acid: alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid: succinic acid, adipic acid, sebacic acid, dodecane. Aliphatic dicarboxylic acids such as dionic acid: One or a combination of two or more thereof may be mentioned. As the diol component other than ethylene glycol, propylene glycol,
1,4-butanediol, diethylene glycol, 1,
One or more of 6-hexylene glycol, cyclohexane dimethanol, an ethylene oxide adduct of bisphenol A and the like can be mentioned. Of course, the combination of these comonomers is preferably such that the melting point of the copolymerized polyester is within the above range.

A polyester particularly suitable in terms of adhesion to metal, workability and prevention of flavor adsorption is mainly composed of poly (ethylene terephthalate / isophthalate) (PET / I).

The polyester used should have a molecular weight sufficient to form a film, for which an intrinsic viscosity (IV) of 0.50 to 1.9 dl / g, in particular 0.55 to 1. Those in the range of 4 dl / g are desirable.

It is important that the polyester film is biaxially stretched. The degree of biaxial orientation can also be confirmed by a polarization fluorescence method, a birefringence method, a density gradient tube method, or the like. The thickness of the film is 8 to 50 μm, in consideration of the barrier property against corrosive components and the processability.
In particular, it is desirable to have a thickness of 12 to 40 μm.

Of course, the biaxially oriented film may contain a compounding agent known per se for the film, for example, an antiblocking agent such as amorphous silica, a pigment such as titanium dioxide (titanium white), various antistatic agents, lubricants and the like. Can be blended according to a known formulation.

The film is generally stretched at 80 to 110 ° C.
From the range of the area stretching ratio of 2.5 to 16.0, particularly 4.0 to 14.0 at the temperature of 1, the ratio of I _A / I _B to the above range in relation to the type of polyester and other conditions. Select the draw ratio. For the heat setting of the film, a heat setting temperature that satisfies the above conditions is selected from the range of 130 to 240 ° C., particularly 150 to 230 ° C.

As the polyester film, of course, a single-layer film can be used, but a laminated film composed of two or more layers can also be used.
As a laminated film, polyethylene terephthalate,
Consists of a polyester surface layer with excellent barrier properties against corrosive components such as polyethylene terephthalate / isophthalate, non-adsorption of contents, etc. and a copolyester, blended polyester or blended copolyester lower layer with excellent adhesion to metals Any thing can be used.

[Manufacture of Laminate Material] Metal-polyester laminate material blank (base plate) used in the present invention
Has polyesters of the portion corresponding to at least the container bottom (A) is in the range of 2.5 to 20, especially 3 to biaxial orientation degree in the range of 20 (I _A / I _B), the container body The part of the polyester (B) corresponding to the formula (2) and (3)
It has a biaxial orientation degree that satisfies the above condition.

The part of the polyester (B) corresponding to the body of the container is formed by preliminarily relaxing the biaxial orientation of the polyester during the production of the laminate. At this time, the part of the polyester corresponding to the body of the container is biaxially oriented. The degree distribution is made to satisfy the above equations (2) and (3).

For this reason, a temperature pattern is formed on the metal plate such that the portion corresponding to the bottom of the can has a relatively low temperature and the portion corresponding to the body of the can has a relatively high temperature, and a metal having this temperature pattern is formed. The board and the polyester film are heat-bonded.

In order to effectively retain the biaxial orientation of the polyester film in the portion corresponding to the bottom of the can, the surface of the metal substrate is heated to a temperature (TA) near the melting point (Tm) of polyester.
In general, it is preferable to maintain the temperature at Tm -50 ° C to Tm + 30 ° C, especially at the temperature from Tm -30 ° C to Tm + 20 ° C for thermal bonding.

On the other hand, the temperature (TB) of the surface of the metal substrate at the portion corresponding to the body of the can is higher than the temperature TA and higher than the melting point (Tm ° C.) of polyester, especially Tm −.
Temperatures from 10 ° C to Tm + 50 ° C, most preferably Tm -5
It is preferred that the temperature be in the range of ℃ to Tm +40 ℃. In order to keep the degree of biaxial orientation of the polyester in the can body portion in the above range, it is important to maintain the surface temperature of the metal substrate in the can body portion at a uniform and uniform temperature. .

For heating the metal substrate, heating means known per se such as energization heat generation, high frequency induction heating, infrared heating, hot air oven heating, roll heating and the like can be used, and in order to perform thermal bonding in a short time, The film to be heat bonded can be preheated under conditions where the biaxial orientation is not substantially relaxed. The preheating temperature is preferably about 50 to 180 ° C.

Among the above heating means, the roll heating means is particularly suitable as an industrial means suitable for forming a temperature pattern on the metal substrate. That is, the metal plate is brought into contact with a heating roll in which the portion corresponding to the bottom of the can is kept at a relatively low temperature and the portion corresponding to the body of the can is kept at a relatively high temperature to form a temperature pattern on the metal plate.

When the temperature pattern is transferred, the heating roll and the metal plate are brought into intimate contact with each other so as to prevent the metal substrate from being thermally deformed and wavy, so that the accurate temperature pattern is transferred. Therefore, for example, at least one nip roll for sandwiching the metal plate with the heating roll may be arranged at a position where the metal plate leaves the heating roll or a position near the upstream side thereof.

In order to make the temperature of the metal plate portion corresponding to the can body portion uniform, it is effective to maintain the nip roll at a temperature equal to or slightly higher than the temperature of the portion corresponding to the can body portion. is there.

Various methods can be used to form the temperature pattern on the heating roll. For example, a sheet-shaped heating element corresponding to the temperature pattern, particularly a sheet-shaped heating element on the high temperature side corresponding to the body and a bottom portion are formed. A selective heating method that incorporates a combination with a corresponding low temperature side sheet heating element in the roll, and heat conduction to the plate is effectively performed in the part corresponding to the body part, and heat conduction is suppressed in the part corresponding to the bottom part A selective heat transfer method is adopted which is performed at a specified rate. In the latter case, in order to suppress heat conduction, the portion of the roll corresponding to the can bottom may be recessed radially inward from the cylindrical surface by a minute interval, or a hollow portion may be provided in the portion corresponding to the can bottom. it can.

The metal plate after the temperature pattern formation and the polyester film are passed through a laminating roll and heat-bonded, and the laminated plate after the heat-bonding is finished as soon as possible in order to prevent excessive relaxation of biaxial orientation. It is better to cool to. This cooling is performed by blowing cold air, spraying cooling water, immersing cooling water, contacting with a cooling roll, or the like.

In forming the temperature pattern, it is preferable that the boundary between the low-temperature bottom corresponding portion and the high-temperature body corresponding portion is as sharp as possible. This is because the boundary between the high temperature portion and the low temperature portion is in a direction of breaking during the time from the formation of the temperature pattern to the lamination, which may lead to insufficient relaxation of the orientation before and after the boundary and deterioration of the dent resistance.

In the present invention, the time required for heat-bonding the polyester film and the time required for relaxing the biaxial orientation are
A fairly short period of time is sufficient, and it is generally sufficient to hold the above-mentioned temperature for 0.005 to 2 seconds.

In the production of the laminate material, the polyester film can be heat-bonded to the metal substrate without using any special adhesive to produce a laminate for drawing-deep drawing. Of course, if desired, an adhesive primer can be interposed at the time of thermal bonding between the two.

A typical primer coating having excellent adhesion and corrosion resistance is a phenol-epoxy type coating composed of a resol type phenol aldehyde resin derived from various phenols and formaldehyde and a bisphenol type epoxy resin. In particular, a phenol resin and an epoxy resin are mixed in a weight ratio of 50:50 to 5:95, especially 4
It is a paint contained in a weight ratio of 0:60 to 10:90.

The adhesive primer layer is generally preferably provided with a thickness of 0.03 to 10 μm. The adhesive primer layer may be provided in advance on a metal material or may be provided in advance on a polyester film.

When an adhesive primer is used, the surface of the biaxially stretched copolyester film can be subjected to corona discharge treatment in order to improve the adhesion to the film. The degree of corona discharge treatment is
It is desirable that the wetting tension be 44 dyne / cm or more.

In addition, it is also possible to subject the film to plasma treatment, flame treatment, or other known adhesion-improving surface treatment, or urethane resin-based or modified polyester resin-based adhesion-improving coating treatment. .

[Thin-walled Deep-drawing Molding] The thin-walled deep-drawing molding in the present invention is carried out by a method known per se except that a laminate plate having the above-mentioned degree of orientation distribution is used.

That is, according to the thin-walled deep drawing (drawing-redrawing forming), as shown in FIG. 8, the front drawing cup 21 formed from the coated metal plate is an annular holding member inserted in the cup. 22 and the redrawing die 23 located therebelow. A redrawing punch 24 is provided coaxially with the holding member 22 and the redrawing die 23 so as to be able to enter and exit the holding member 22. The re-drawing punch 24 and the re-drawing die 23 are relatively moved so as to mesh with each other.

As a result, the side wall portion of the front draw cup 21 is bent from the outer peripheral surface 25 of the annular holding member 22 through the curvature corner portion 26 thereof to the radial inward direction and is bent vertically to the annular bottom surface 27 of the annular holding member 22. And the upper surface 28 of the redrawing die 23, and is bent substantially vertically in the axial direction by the action corner portion 29 of the redrawing die 23 to form a deep drawing cup 30 having a smaller diameter than the front drawing cup 21. Then, the side wall is bent and stretched to be thinned. For deep drawn cans, In the formula, D is the diameter of the sheared laminate material, and d is the diameter of the punch. The practical drawing ratio _RD defined in the range of 1.1 to 3.0 in one step, and 1.5 to 5 in total .
It should be in the range of 0.

[0090] In the present invention, the following equation (7) Rr = in _{((t 0 -t w) /} t 0) × 100 ... (7) equation can body is compared to the can bottom, t ₀ is The thickness of the bottom of the can, and t _W is the thickness of the body of the can.
In particular, the thickness can be reduced to 20 to 80%.

Further, by engaging the re-squeezed cup with an ironing die, ironing is added to the side wall of the cup,
It is an advantage of the present invention that excellent corrosion resistance can be maintained even when the side wall portion can be made thinner, and even if the side wall portion is thinned by ironing in this way.

[0092]

The present invention will be described in more detail with reference to the following examples.

[Example 1] Base plate thickness 0.18 mm, temper DR
A 20 μm thick biaxially oriented polyethylene terephthalate isophthalate (PET / I) film was heat-bonded to both sides of a -9 tin free steel (TFS) plate to obtain an organic coated metal plate. The temperature of TFS when heat-bonded is 233 ° C on average in the part corresponding to the bottom and bottom of the final can, and 242 ° C on average in the part corresponding to the upper part of the can body. A nip roll was used when transferring to the plate. As a result, the degree of biaxial orientation was as shown in Tables 1 to 3, respectively.

A wax lubricant was applied to this coated metal plate, which was punched into a disk having a diameter of 150 mm and then formed into a shallow-drawing cup by a conventional method. The drawing ratio in this drawing process is 1.63. Then, under the following molding conditions, the primary / secondary redrawing process (thinning deep drawing:
A) was performed. Primary redrawing ratio 1.18 Secondary redrawing ratio 1.18 Redrawing die Working corner radius of curvature (Rd) 0.40 mm Holding corner radius of curvature (Rh) 2.0 mm The draw-formed deep-drawn cup was then bottom domed. The characteristics of the deep drawing cup are as follows. Cup diameter: D 66 mm Cup height: H 130 mm → H / D = 1.97 Side wall thickness reduction rate 50%

This organic coated deep-drawn cup is degreased and heat set by heat-treating it at 210 ° C. with the flange attached, and then trimming / printing (210 ° C.).
Baking for 15 seconds), necking, and flanging were performed to create a seamless can by thinning and deep drawing. Table 1
3 to 3 show the characteristics and evaluation of this laminated metal plate and can body. As a result of using this laminated metal plate having excellent formability, it was possible to obtain a seamless can by thinning deep drawing having excellent corrosion resistance.

[Example 2] Thickness of blank plate 0.18 mm, temper DR
A 20 μm thick biaxially oriented polyethylene terephthalate isophthalate (PET / I) film was heat-bonded to both sides of a -9 tin free steel (TFS) plate to obtain an organic coated metal plate. The temperature of TFS when heat-bonded is 235 ° C. on average in the lower and bottom portions of the final can, and 240 ° C. in average on the upper portion of the can body, which are shown in Tables 1 to 3, respectively. The degree of biaxial orientation was as follows. Using this coated metal plate, a seamless can was drawn by squeezing and ironing in the same manner as in Example 1. Table 1
3 to 3 show the characteristics and evaluation of this can body. In this example, the distribution of the biaxial orientation degree of the laminated metal plate satisfied the formula (3), which is the range of the present invention, so that the molding was possible.
Since the distribution of the uniaxial orientation degree of the can body was out of the range of the present invention as a result of not satisfying the formula (4), the adhesion between the film and TFS was inferior at the neck portion and corrosion occurred. Further, since the degree of biaxial orientation of the bottom of the can was not so high, the corrosion resistance performance was insufficient for filling with a highly acidic beverage.

[Example 3] Base plate thickness 0.18 mm, temper DR
A 20 μm thick biaxially oriented polyethylene terephthalate isophthalate (PET / I) film was heat-bonded to both sides of a -9 tin free steel (TFS) plate to obtain an organic coated metal plate. The temperature of TFS when heat-bonded is 233 ° C on average in the lower and bottom parts of the final can and 242 ° C in the part corresponding to the upper part of the can body. It was the degree of axial orientation. The distributions of the degree of biaxial orientation in this example are expressed by Equations (3) and (4).
Since both were not satisfied and were out of the range of the present invention, the formability was remarkably inferior, and the glass was crushed during the drawing-ironing process.

[Example 4] Thickness of blank plate 0.18 mm, temper DR
A 20 μm thick biaxially oriented polyethylene terephthalate isophthalate (PET / I) film was heat-bonded to both sides of a -9 tin free steel (TFS) plate to obtain an organic coated metal plate. The temperature of the TFS when heat-bonded was 233 ° C on average in the lower and bottom parts of the final can and 237 ° C in the upper part of the can body. It was the degree of axial orientation. Using this coated metal plate, a thin-walled deep-drawn seamless can was prepared in the same manner as in Example 1. Tables 1 to 3 show the properties and evaluations of this laminated metal plate and can body. The distribution of the degree of biaxial orientation of the laminated metal sheet of this example satisfied the formula (3), which is the range of the present invention, and molding was possible, but the formula (4) was not satisfied, resulting in a can body. The degree of uniaxial orientation was outside the range of the present invention, and therefore, partly did not satisfy the relational expression (5) of the present invention, so that the upper part of the can was partially whitened and the moldability was poor.

[Example 5] A biaxially stretched polyethylene terephthalate isophthalate (P) having a thickness of 20 µm was formed on both surfaces of an aluminum alloy plate (3004H34) having a thickness of 0.26 mm.
The organic coated metal plate was obtained by heat-bonding the ET / I) film. The temperature of the aluminum alloy plate when heat-bonded is 2 on average in the parts corresponding to the bottom and bottom of the final can.
The temperature was 33 ° C., and the portion corresponding to the upper part of the can body was 243 ° C. on average, and a nip roll was used when transferring these temperature patterns from the heat roll to the aluminum alloy plate. As a result, the degree of biaxial orientation was as shown in the table.

A wax-based lubricant was applied to this coated metal plate, which was punched into a disk having a diameter of 150 mm and then formed into a shallow-drawing cup according to a conventional method. The drawing ratio in this drawing process is 1.63. Then, under the following molding conditions, the primary / secondary redrawing process (thinning deep drawing:
A) was performed. Primary redrawing ratio 1.18 Secondary redrawing ratio 1.18 Redrawing die Working corner radius of curvature (Rd) 0.40 mm Holding corner radius of curvature (Rh) 2.0 mm The draw-formed deep-drawn cup was then bottom domed. The characteristics of the deep drawing cup are as follows. Cup diameter: D 66 mm Cup height: H 130 mm → H / D = 1.97 Side wall thickness reduction rate 50%

This organic coated deep-drawn cup is heat-treated at 210 ° C. with a flange to degrease and heat-set, and then trimming / printing (210 ° C.).
Baking for 15 seconds), necking, and flanging were performed to create a seamless can by thinning and deep drawing. Table 1
3 to 3 show the characteristics and evaluation of this laminated metal plate and can body. As a result, even when an aluminum alloy plate was used as the metal plate, it was possible to obtain a seamless can by thinning and deep drawing which was excellent in formability and corrosion resistance.

Example 6 An organic coated metal plate was obtained by thermally adhering a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 20 μm to both surfaces of a tin plate having a thickness of 0.20 mm. The temperature of the tin plate when heat-bonded is 2 on average in the parts corresponding to the bottom and bottom of the final can.
The temperature was 33 ° C., and the portion corresponding to the upper part of the can body was 243 ° C. on average, and a nip roll was used when transferring these temperature patterns from the heat roll to the tin plate. As a result, the degree of biaxial orientation was as shown in the table. Using this coated metal plate, a thin-walled deep-drawn seamless can was prepared in the same manner as in Example 1. Tables 1 to 3 show the properties and evaluations of this laminated metal plate and can body. As a result, even if a tin plate was used as the metal plate, it was possible to obtain a seamless can by thinning and deep drawing which was excellent in formability and corrosion resistance.

[0103]

[Table 1]

[0104]

[Table 2]

[0105]

[Table 3] * Note (1) Here, the right side of equation (5) is 1-ex
It refers to a value of p [-0.45I _A / I _B -1.1ε + 0.53].

[0106]

According to the present invention, in a seamless can using a metal-polyester laminate material in which the bottom of the can has a high degree of biaxial orientation and the body of the can has a low degree of biaxial orientation, a laminate corresponding to the body of the can By suppressing the distribution of the degree of biaxial orientation of the material within the range that satisfies the above formulas (2) and (3), the occurrence of anisotropic defects seen in this type of seamless can is prevented, and the workability and resistance to The physical properties of the contents could be improved. Further, the occurrence of anisotropic defects could be effectively suppressed even when the degree of thinning of the side wall portion was increased and when the degree of diameter reduction of the neck portion was increased.

[Brief description of the drawings]

FIG. 1 is a plan view of a laminate plate used for deep drawing.

FIG. 2 is an enlarged cross-sectional view of the laminate plate of FIG.

FIG. 3 is an X-ray diffraction diagram for explaining a measuring method for obtaining a degree of biaxial orientation of polyester.

FIG. 4 is a graph showing a relationship between a β scan angle and a diffraction intensity for a can body polyester film.

FIG. 5: cos ² φ for various heights of the can body
6 is a graph showing a relationship between the height and the height.

FIG. 6 is an explanatory diagram for explaining generation of distortion with respect to a blank and a can body.

FIG. 7 is a partial cross-sectional side view of a seamless can.

FIG. 8 is an explanatory diagram for explaining thinning deep drawing.

[Explanation of symbols]

 1 Blank 2 Metal Substrate 3 Polyester Film Inner Layer 4 Outer Layer 5 Part Formed on Container Bottom 6 Part Formed on Container Body 10 Deep Drawing Can 11 Bottom 12 Body Side Wall 13 Neck 14 Flange 15a, 15b Adhesive Layer 21 front drawing cup 22 annular holding member 23 redrawing die 24 redrawing punch 25 outer peripheral surface of holding member 26 curvature corner portion 27 annular bottom surface 28 die upper surface 29 die working corner portion 30 deep drawing cup

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 5, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

The winding portion is connected to the body of the can through a neck portion, and the neck portion has the following formula (8) R = ((D-D ₁ ) / D) × 100 (8) The diameter reduction ratio defined by D is the inner diameter of the can body portion and D ₁ is the inner diameter of the neck portion is preferably 5 to 40% .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B65D 8/04 B65D 8/04 G 8/16 8/16 25/14 25/14 A (72) Inventor Toshirou Washizaki 3-1-1 Higashirokugo, Ota-ku, Tokyo Fair Court No.314 Tamagawa (72) Inventor Hideo Kurashima 3-26-16 Iwato, Yokosuka City, Kanagawa Prefecture (72) Katsuhiro Imazu Izumi, Yokohama City, Kanagawa Prefecture 6205-1, Izumi-cho, Ward 27-101 Greenheim Izumino

Claims (12)

[Claims] 1. A metal and a laminate plate for seamless can produced comprising a polyester film, a polyester of the circular portion to a seamless can bottom (A) has the formula _{(1) Rx = I A /} I B ... (1) In the formula, I _A is a diffraction intensity by a diffractive surface having a surface interval of about 0.34 nm (CuKα X-ray diffraction angle of 24 ° to 28 °) parallel to the polyester film surface of the can bottom, and I _B is the can bottom part. Spacing parallel to the polyester film surface of 0.39 nm (CuKα X-ray diffraction angle from 21.5 ° to 2
4 °) is a polyester having a biaxial orientation degree (Rx) of 2.5 to 20 defined by the diffraction intensity by a diffractive surface, and the polyester (B) in the other portion corresponding to the can body is , Rx _BM ≤ 0.95 Rx (2) and (Rx _BM- Rx _Bm ) ≤ 1800 x (Rx _BM ) ^-5 (3) In the formula, Rx _BM is a can body. Rx _Bm is the degree of biaxial orientation of the maximum orientation portion in the corresponding portion, Rx _Bm is the degree of orientation of the minimum orientation portion of the portion corresponding to the can body portion circumferentially separated from the maximum orientation portion, Rx _Bm
A laminated plate having a biaxial orientation degree satisfying that x has the above-mentioned meaning. 2. The polyester layer (B) has a biaxial orientation degree satisfying the following formula (4) (Rx _BM −Rx _Bm ) ≦ 240 × (Rx _BM ) ⁻⁴ (4). The laminated plate according to claim 1. 3. The laminate according to claim 1, wherein the polyester layer (A) and the polyester layer (B) are polyesters having the same composition. 4. The laminate according to claim 1, wherein the polyester is polyethylene terephthalate or a copolymerized polyester mainly composed of ethylene terephthalate. 5. The laminate according to claim 1, wherein the metal is TFS, tinplate or aluminum-based metal. 6. A laminate of a metal and a polyester film having a H / D (H: height, D: bottom diameter) ratio of 1.
In seamless cans formed by molded into a cup shape so that 5 or more, the polyester (A) has the formula the can bottom _{(1) Rx = I A /} I B ... (1) polyester film I _A is the can bottom in formula Diffraction intensity by a diffractive surface having a plane distance of about 0.34 nm (CuKα X-ray diffraction angle of 24 ° to 28 °) parallel to the surface, and I _B is a plane distance of about 0.39 nm parallel to the surface of the polyester film at the bottom of the can. (CuKα X-ray diffraction angle from 21.5 ° to 2
4 °) is a polyester layer having a biaxial orientation degree (Rx) of 2.5 to 20 defined by the diffraction intensity by a diffractive surface, and the polyester layer (B) of the body of the can is directly below the tightening portion. and in the most uniaxially oriented by being part of the circumferential direction, in the following formulas ^{(5) 0.55 <cos 2 φ} M <1-exp _{[-0.45I a / I B -1.1 ε +} 0.53 ] ... (5) formula, cos ² φ _M is an index representing the degree of maximum uniaxial orientation of the polyester film in the can body measuring section, I _A and I _B have the above-mentioned meanings, and ε is the processing of the laminate material in the can body measuring section. It is a considerable strain. In the minimum uniaxial orientation part that has a uniaxial orientation degree satisfying the above condition and is separated from the maximum uniaxial orientation degree part in the circumferential direction, formula (6) (cos ² φ _M −cos ² φ _m ) ≦ 25 × 10 ⁻⁴ × (cos ² φ _M ) ^-40 (6) In the formula, cos ² φ _m is an index representing the degree of uniaxial orientation in the minimum uniaxial orientation portion of the can body polyester layer, and cos
² φ _M has a uniaxial orientation degree satisfying the above-mentioned meaning, and a seamless can. 7. A formula can body is compared to the can bottom (7) Rr = ((t 0 -t w) / t 0) × in 100 ... (7), t ₀ is the thickness of the can bottom 7. The seamless can according to claim 6, wherein t _W is the thickness of the can body, and the thickness is reduced so that the reduction rate of the thickness is 15 to 80%. 8. The seamless can according to claim 6, wherein the polyester layer (A) and the polyester layer (B) are polyesters having the same composition. 9. The seamless can according to claim 6, wherein the polyester is polyethylene terephthalate or a copolymerized polyester mainly composed of ethylene terephthalate. 10. The seamless can according to claim 6, wherein the metal is TFS, tin or an aluminum-based metal. 11. The winding portion is connected to a can body portion via a neck portion, and the neck portion has the following formula (8) R = ((D−D ₁ ) / D) × 100 (8) 11. The seamless can according to claim 6, wherein the diameter reduction ratio defined by D is the inner diameter of the can body portion and D ₁ is the inner diameter of the neck portion is 5 to 40%. 12. The laminated plate according to claim 1 is subjected to drawing and redrawing so that the H / D (H: height, D: bottom diameter) ratio is 1.5 or more, and at least the final drawing. A method for producing a seamless can, which comprises thinning a cup body by bending and stretching it in a deep-drawing step or by ironing.