JPS604058B2 - container lid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to metal container lids, more particularly those having an intrinsic viscosity of 0.7 to 2 as measured in orthochlorophenol at a concentration of 1.0 m/100' and at 300 m. .8 and wherein at least 45 mole % of the glycol component, including those contained in the form of polyether glycol, consists of tetramethylene glycol and at least 66 mole % of the dibasic brewing component consists of terephthalic acid. The present invention relates to a container lid characterized in that it is formed by drawing or press-forming a material made of a foil-like or sheet-like metal substrate coated with flexible polyester or polyester ether into the shape of the lid.

Conventionally, container lids have been made by drawing a painted aluminum or tin plate into the corners, forming a peal at the end of the entrance, and using a so-called screw cap with a screw on the periphery, or a painted cap. A so-called crown is widely used, which is made by stamping a circular tin plate with a coating applied to it, forming a skirt around it, and pasting packing on the inner surface.

The paint to be applied to such container lids is phenol.
Paints such as epoxy, phenol-suria, and epoxy-suria are widely used. All of the paints that have been put into practical use for metal container lids are solvent-based and thermosetting paints, and when forming a paint film, it is necessary to remove the solvent and apply the paint film, making it extremely difficult to use. The manufacturing process was unsatisfactory in that it required a dovetail furnace and equipment to remove the solvent in the exhaust gas. In recent years, in the field of paints, solvent-free paints have been developed as so-called pollution-free paints.

These solvent-free paints include paints that have the fluidity necessary for painting and that polymerize to form a coating film under the action of light, radiation, or catalysts, and paints that are based on powdered thermoplastic resins. It has been known. However, paints for container lids have many aspects such as workability of the coating and durability of the formed coating film, processability of the material, corrosion resistance, flavor retention of the food contents, and retort sterilization resistance. subject to restrictions.

For example, paints based on thermoplastic resins generally have unsatisfactory adhesion to metal materials for container lids, are insufficient in terms of corrosion resistance, and are difficult to process by drawing, pressing, or beading. Severe processing conditions often result in damage or peeling of the coating. That is, when drawing or pressing a container lid, the metal material exceeds its elastic limit and causes plastic flow, and the coating layer cannot follow this plastic flow, resulting in damage or peeling of the coating. In addition, paints made of thermoplastic resin generally extract a large amount of components into the food contents, giving the food a so-called poly-smelling odor and impairing the flavor. It becomes even larger when heat sterilization (retort sterilization) is performed.

Thus, to the best of the inventors' knowledge, the adhesion to the metal material for container lids, the processability of coating, and the resistance to citrus I of the coating film,
In particular, there is no known thermoplastic resin type paint for metal container lids that is particularly excellent in these combinations.

The present inventors have discovered that the above-mentioned specific thermoplastic polyester or polyester ether has outstanding adhesion (adhesiveness) to metal materials for container lids, and that the metal materials coated with this film can be drawn or Even when subjected to severe processing for lid formation such as press processing or bead processing, plastic flow follows the plastic flow of the metal material, and the workability is maintained without damage or peeling of the coating film. and this coating film prevents resin components from migrating into the food contents even when in contact with the food contents for a long time or at high temperatures during retort sterilization, and has excellent extraction resistance and flavor. The inventors have discovered that this material has excellent retention and corrosion resistance, and have arrived at the present invention.

In accordance with the present invention, a number of advantages are achieved by using certain thermoplastic polyesters or polyester ethers as protective coatings on metal container lids.

That is, the thermoplastic polyester or polyester ether used in the present invention can be directly applied in the form of a melt onto a metal material for forming a container lid by a method known as extrusion lamination, or it can be applied in the form of a film, powder, etc. It can be applied as a coating film by applying it on the surface of a metal material and then fusing it on the spot, and does not use solvents that cause air pollution, and does not require processes such as forming. It becomes possible to form a protective coating film with constant properties without coating defects. In addition, since the thermoplastic polyester or polyester ether in the present invention has excellent processability and rust prevention properties, it can be applied to the metal material before molding, which may occur during each processing step. The occurrence of rust can be completely prevented.

As a result, rust is likely to occur, and roughened steel plates (black, etc.)
plate), chemically treated steel sheets such as phosphate-treated steel sheets, chromic acid-treated steel sheets, or lightly treated electrolytic chromic acid-treated steel sheets can be used for manufacturing metal container lids.Furthermore, The protective coating film made of the thermoplastic polyester or polyester ether in the present invention exhibits excellent adhesion or adhesion to metal substrates, and this property is due to the fact that it contains acids and salts that are highly corrosive to metals. It will not be lost even in applications where the contents are in contact with the paint film for a long period of time, or when a lidded container filled with contents is heat sterilized.

Moreover, surprisingly, the coating film made of thermoplastic polyester or polyester ether does not impart a so-called poly-odor to the food contents and does not impair the delicate flavor of the food. The above-mentioned advantage is that among various polyester resins, the intrinsic viscosity measured in orthochlorophenol at a concentration of 1.0 m/100 skin is in the range of 0.7 to 2.8, and polyether glycol A thermoplastic polyester or polyester ether in which at least 45 mol% of the total glycol component, including those contained in the form of This is achieved by selectively using it as a protective coating for container lids.First of all, the polyester coating used in the present invention is thermoplastic, unlike conventional polyester coatings, which are thermosetting. There is a marked difference.

That is, the conventional thermosetting polyester paint is composed of a homogeneous liquid composition of a relatively low molecular weight unsaturated polyester having an ethylenic double bond and a polymerizable ethylenically unsaturated monomer. A composition made of this composition is applied to a substrate and then cured to form a coating film by the action of light, ionizing radiation, heat, a catalyst, or the like. Not only do such paints require special curing means, but when the coating film that is formed comes into contact with the food contents, there is a strong tendency for resin components to migrate into the food contents, impairing the flavor. However, it is generally difficult for this coating film to withstand severe processing such as drawing or pressing. On the other hand, the paint made of polyester or polyester ether used in the present invention is
A high molecular weight thermoplastic polymer obtained by pre-condensing a dibasic brewing component and a glycol component,
It does not have the drawbacks of thermosetting polyester paints mentioned above. The polyester or polyester ether used in the present invention comprises at least 45 mol% of the glycol component, more preferably 55 mol% or more of tetramethylene glycol, and at least 66 mol% of the dibasic acid component;
It is important for the purposes of the present invention that more preferably 85 mole percent or more consists of terephthalic acid.

The glycol component is tetramethylene** recall (1,
Polyesters or polyester ethers made of glycols other than 4-butanediol, such as ethylene glycol, have low adhesion strength to metal substrates, have low flexibility of the coating film itself, and can be subjected to harsh processing conditions such as drawing. There is a tendency that the coating film peels off from the metal substrate or the coating layer itself becomes zesty. This tendency is similarly observed in the case of copolyethers in which the content of the tetramethylene glycol component contained as the glycol component is lower than the above-mentioned 45 mol %. In addition, the dibasic brewing component is a dicarboxylic acid other than terephthalic acid, such as isophthalic acid,
In the case of polyesters or polyester ethers made of adipic acid, etc., or copolyesters in which the content of tephthalic acid in the dibasic acid component is lower than 66%, the resin components in the coating film tend to migrate into the contents. As it grows larger,
The corrosion resistance of the coating film is also unsatisfactory, and the mechanical properties of the coating film are also poorer than those within the scope of the present invention. According to the present invention, a polyester, a polyester ether, and a glycol component containing 45 mol% or more of tetramethylene glycol in the form of a monomer or polyether based on the total glycol, and a dibasic acid component containing 66 mol% or more of terephthalic acid. By using this, a desirable combination of adhesion or adhesion to the metal substrate for container lids, workability, corrosion resistance, and extraction resistance can be obtained. The polyester or polyester ether used in the present invention generally has the following formula, R,
is a divalent hydrocarbon group, at least 66 mol% of the hydrocarbon group R is a p-phenylene group, and each of R2 and R3 is a divalent aliphatic hydrocarbon group, R
2 and R3 may be the same or different, the groups R2 and 4 at least 45 mol% of R3 are tetramethylene groups, p and q are numbers of 1 or more, m and n are zero or 1 or more , and when one of m and n is zero, the other is a number of 1 or more.

It consists of units of

In the above general formula, the divalent hydrocarbon group R is,
A linear or branched alkylene group having 2 to 13 carbon atoms,
Cycloalkylene group having 4 to 12 carbon atoms, and 6 carbon atoms
It can consist of 1 to 15 arylene groups.

From the point of view of extraction resistance and mechanical properties of the coating film, it is most preferable that all divalent hydrocarbon groups R, be arylene groups, but up to 34 mol% of all divalent hydrocarbon groups R, Substitution with alkylene or cycloalkylene groups is acceptable. As arylene groups other than p-phenylene groups,
For example, 01- or m-phenylene group, naphthylene group, and where R4 is a direct bond, or 10-, 1CH2, 1CH(CH3)-, 1C(CH3)2-, or 1ZNH
- represents a divalent bridging group such as a group.

The following groups can be mentioned.

Further, as the alkylene groups R2 and R3, alkylene groups having 2 to 13 carbon atoms can be mentioned, and among these, a straight mirror alkylene group is preferable.

ZAs the divalent aliphatic hydrocarbon group, groups other than alkylene groups, such as 0-, m- or p-xylene groups, 1,4- There is no problem even if the aliphatic hydrocarbon containing an aromatic ring such as a dimethylenecyclohexylene group or a saturated moiety as an intermediate group is contained. In the polyester or polyester ether used in the present invention, the glycols may be contained in the form of {a-all dibasic acids, i.e., in the form of ester repeat units, or {b}all ester ether 2
'c' may be contained in the form of an ester repeating unit, and the remaining part is in the form of a polyether glycol and a dibasic acid, i.e., an ester ether repeating unit. may be contained.
3 In the case of {a} above, the general formula {1
1', the number of repetitions n of the ester ether unit is zero, or p in the ester ether unit is 1,
Polyesters can be homopolyesters or copolyesters, consisting entirely of ester repeating units. Suitable examples of such polyesters and copolyesters are as follows. Polytetramethylene terephthalate, polytetramethylene/ethylene terephthalate, polytetramethylene terephthalate/isophthalate, polytetramethylene/ethylene terephthalate/isophthalate, polytetramethylene/ethylene terephthalate/hexahydroterephthalate.

In the case of [b} above, in the general formula, the number m of repeating ester units is zero and the number of repeating ether units is 2 or more, and this polyester ether contains only the ester ether unit 'B-.

It is desirable to select the repeating number p of the ether unit so that the average molecular weight of the polyether glycol is in the range of 200 to 4000, and within this range, the average molecular weight of the polyether glycol is in the range of 400 to 2.
It is preferable to select p to be in the range of 000. Suitable examples of such polyester ethers are as follows. Polyoxytetramethylene terephthalate, polyoxytetramethylene/oxyethylene terephthalate, polyoxytetramethylene/oxyethylene. Terephthalate/Isophthalate.

In the aspect of the foregoing c} of the present invention, the general formula '1'
' where both m and n are numbers of 1 or more, and p is a number of 2 or more.

In this case, the ester unit and the ester ether unit 'B
) is not particularly limited, and this polymer has the general formula Kazem1 (B'n Kazem-[B}n-Kazem (B'n-Kazem1'BL Ichifumikken A block copolymer as shown by -, or the general formula A-
It may be in the form of a random copolymer as shown by A-A-B-A-A-B-B-B-.

The repeating number p of the ether unit in the ester ether unit 'B} is the number of carbon atoms (group R
Generally, p is selected so that the average molecular weight of the polyether glycol is in the range of 200 to 4,000, and the average molecular weight of polyether glycol is in the range of 400 to 2,000. Good. In the embodiment of the present invention in which the polyester ether type polymer of [c] is used, the tetramethylene glycol component can be incorporated into the ester unit [B-] in the form of a polyether, or can be incorporated into the ester units [B-] in the form of an ester. It can also be incorporated.

Of course, a combination of these two can also be adopted. Importantly, at least 45% of the total glycol components, including those incorporated in the form of polyether glycols,
The mole percent, preferably 55 mole percent or more, consists of tetramethylene glycol. In this specification, when the degree of polymerization of polyether glycol is p, calculations are made by considering this polyether glycol as pmol of glycol. Suitable examples of such copolyesters are as follows.

Tetraethylene terephthalate/polyoxymethylene terephthalate copolymer, tetraethylene terephthalate/polyoxyethylene terephthalate copolymer, ethylene terephthalate/polyoxytetramethylene terephthalate copolymer, tetraethylene terephthalate/polyoxytetramethylene terephthalate/polymer Oxyethylene terephthalate copolymer, polytetramethylene terephthalate/polytetramethylene glycol block copolymer, polytetramethylene terephthalate/polytetramethylene glycol/polyethylene glycol
Block copolymer "Polytetramethylene terephthalate no polypropylene glycol no polytetramethylene glycol/polyethylene glycol block copolymer.

The molecular weight of the polyester or polyester ether in the present invention is 1.0/10 in orthochlorophenol.
Intrinsic viscosity measured at a concentration of 0 and at 30°C
h] is 0.7 to 2.8, more preferably 1.0 to 2.0
This range is important in terms of adhesion to metal substrates, workability, and mechanical properties.

If this intrinsic viscosity is lower than the above range, the mechanical properties of the coating film will be poor compared to those in the range of the present invention, and if it is higher than the above range, the processability of the resin itself or the properties of the coating film will be poor. Processability deteriorates. Furthermore, by selecting the intrinsic viscosity within the above range, a desirable combination of excellent adhesion to metal substrates and processability can be achieved. The polyester or polyester ether used in the present invention varies depending on the composition ratio of ester units and ester ether units and the way they are bonded, but the polyester or polyester ether is 130 to 25
It is desirable to have a softening temperature of 150 to 23,500, particularly preferably from 150 to 23,500, in view of the balance between heat resistance and thermal adhesion of the coating film.

Polyester or polyester ether with a softening temperature higher than 250 qo may cause thermal deterioration of the polymer when thermally bonded to a metal substrate, and it may take a long time to fuse or cool the polyester, making it difficult to paint. These polyesters are unfavorable in terms of coating efficiency and generally lack processability in coatings. On the other hand, polyester and polyester ether with a softening temperature lower than 130 qo may cause blocking of the coating film.
Furthermore, defects may occur in the extraction resistance and heat resistance of the coating film. The above-mentioned polyester or polyester phenolic polymer comprises a dicarboxylic acid of the formula HOOC1R, 1COO or an ester-forming functional derivative thereof, and
b} diol of formula HC-R2-H or its ester-forming functional derivative; and {c
}Formula H←.

Produced by condensation polymerization of at least one poly(oxyalkylene) glycol or functional derivative thereof, in which k' is a number of 1 or more than 2, by means known per se. .

Of course, in this case at least 66 mol% of the dicarboxylic brewing component is terephthalic acid and at least 45 mol% of the total glycol component, including that used in the form of poly(oxyfulkylene) glycol, is tetramethylene glycol. It is necessary that there be. Dicarboxylic acids that can be used in combination with terephthalic acid include isophthalic acid,
Diols used in combination with tetramethylene glycol include ethylene glycol, propylene glycol,
Examples include 1,4-dimethylenecyclohexylene glycol. In addition, in order to adjust the physical properties of the polyester or copolyester formed, a monofunctional or trifunctional alcohol or carboxylic acid may be added to the molecular weight (or viscosity) and softening temperature of the present invention, following a method known per se. It can be added within a range that satisfies the following conditions.

Furthermore, additives such as alkali and alkaline earth metal oleic acid salts can be added according to methods known per se.

When synthesizing a homopolyester or copolyester consisting only of ester units, the dicarboxylic component of the formula Z [a-] and the diol component of the formula 'bi' may be reacted.

In addition, when synthesizing a homopolyester ether or a copolyester ether consisting only of the ester table unit 'B}, the dicarbonate brewing component of the formula 'a} and the polyester ether of the formula 'c} are combined. What is necessary is to react with an oxyalkylene glycol component. Of course, in this case, before the reaction or in the reaction system, the dicarboxylic acid component of the above formula {a) and the diol component of the above formula 'b} are reacted to form a bishydroxyester, and this bishydroxyester 2 and the above It may also be reacted with a polyoxyalkylene glycol of the formula {c-. Furthermore, when synthesizing a polyester ether consisting of an ester unit and an ester ether unit [B}, the three components of the formulas 'a}, {b' and {c-] may be reacted. In this case, there is no particular restriction on the order in which the polyester ether type polymer is synthesized. For example, a polyester is synthesized from the dicarboxylic acid component of the above formula [a} and the glycol of the above formula {b-, and this is reacted with the polyether glycol of the above formula [c' to react with polyester ether. Alternatively, the three of the above formulas {a}, {b), and 'c) may be mixed from the beginning and polycondensation may be performed. According to the present invention, the above-mentioned specific polyester or polyester ether is applied as a coating to a metal material for forming a container lid.

3 The metal material for forming the container lid varies considerably depending on the degree of processing to be performed later, but generally metal foil with a thickness in the range of 1 to 100 microns, particularly 5 to 100 microns, or A metal sheet of 100 microns or more is used. There are no particular restrictions on the type 4 metal material, and for example, foil or sheet-like surface-untreated steel (black plate), surface-treated steel, and light metals such as aluminum are used. Suitable examples of surface-treated steel include chemical treatments such as phosphoric acid treatment and chromic acid treatment;
Examples include those in which the surface of foil or sheet steel is subjected to electrolytic treatment such as electrolytic chromic acid treatment or electrolytic tin plating, or melt plating treatment such as molten tin plating treatment. One of the particularly important features of the present invention, as mentioned above, is that untreated steel foil or sheet, or steel foil or sheet whose surface has been lightly chemically or electrolytically treated, can be used for container lids. The specific polyesters or polyester ethers described above exhibit excellent adhesion to these steel substrates and can effectively prevent corrosion of the steel substrates. A further remarkable advantage of the present invention is that by coating the surface of the metal material with the above-mentioned polyester or polyester ether, drawing or pressing of the metal material, which has been difficult to perform, is possible. The object of the present invention is to make it possible to significantly improve the degree of processing of these metal materials.

For example, a steel plate (D
R material) was difficult to draw or bead, but according to the present invention, by pre-coating it with the aforementioned polyester or polyester ether, it becomes possible to draw and bead as shown in the examples below. It is possible to reduce the amount of metal material required and to reduce the weight of the container lid. Furthermore, defects or inclusions that unavoidably exist on the surface or inside of conventional steel sheets often cause peeling or damage of the coating during processing, causing rust or iron elution. Certain polyesters or polyester ethers, regardless of the presence of the aforementioned defects or inclusions,
It exhibits excellent workability and adhesion, and does not cause rust on the container lid after processing or during use, or cause iron elution. The polyester or polyester dye described above can be applied to the metal substrate by any means. For example, this polyester or polyester ether can be applied on the surface of a metal material by a method called extrusion lamination, which consists of extruding it in a molten state into a thin film. At this time, the polyester or polyester ether in the present invention is
It has excellent processability not only in the coating state but also in the molten state, so by adjusting the extrusion temperature of the resin and the moving speed of the metal substrate, it is possible to process It is possible to provide extremely thin coating layers. Alternatively, the polyester described above can be extruded into a film by a film forming method known per se, such as a T-die method or an inflation method, and this film can be fused to the surface of a metal substrate. Or furthermore,
The aforementioned polyester can be formed into a powder by means known per se, and this powdered polyester can be applied to a metal substrate by means such as a fluidized casting method, an electrostatic coating method, a powder spraying method, or the like. The polyester of the present invention can, of course, be applied to the metal substrate in the form of a solution or dispersion, but in this case the advantages of the present invention of streamlining and pollution-free coating processes will be lost. Prior to fusing the polyester in the present invention to a metal substrate, the surface of the metal substrate is degreased or an anchoring agent such as a titanate ester or an isocyanate compound is applied to the surface of the metal substrate according to well-known means. It should be understood that according to the present invention, the use of such anchoring agents is generally not necessary, although it is also possible to apply them.

The polyester coating agent is applied to the surface of the metal material that will become the inner surface of the container lid when formed into a container, and more preferably to both surfaces of the metal material.

There is no particular limit to the thickness of the polyester coating layer as long as there are no coating defects such as pinholes. For example, according to the present invention, even if the coating film is as thin as 10 microns, there will be no coating defects such as pinholes. A significant advantage is that defects are less likely to occur, while properties such as sacrificiality and ductility necessary for processing the coating layer are not lost even when the coating film is quite thick, such as 150 microns. However, making the coating film too thin is a problem in terms of reliability of corrosion resistance, and making the coating film too thick is a problem in terms of economic efficiency. Therefore, in the present invention, generally
Preferably, the coating has a thickness of 0 to 90 microns, especially 15 to 60 microns. The metal container diamond of the present invention can be formed into a known shape by a known method, except for using a metal material coated with the above-mentioned polyester or polyester ether, that is, a laminate material.

In order to manufacture the metal container lid of the present invention, first, as shown in FIG. The covering material 3 consisting of ' is punched out into a shape such as a disk, and then formed into a container lid by drawing or pressing. In FIG. 2 showing an example of the screw cap according to the present invention, the cap 4 made of the coating material is provided with a recess 5 on the periphery corresponding to the spiral of the bottle mouth, and the closed end thereof has a recess 5 extending outward. A bead 6 is provided.
A knurl 7 is provided in the vicinity of the connecting portion between the top slope portion and the peripheral portion of the cap 4 to facilitate opening of the cap, and a packing 8 is housed in the inner surface of the top plate portion. In FIG. 3 showing an example of a paper vacuum cap, the cap 4 made of the covering material has an open end 9 slanted outward, and is filled with packing 8 from the entrance end 9 to the periphery. The packing 8 engages with the side surface of the bottle closing portion to achieve sealing.

A coin or the like can be inserted into the gap between the sloping open end 9 of the cap and the bottle mouth and lifted upward. In FIG. 4 showing an example of the anchor cap, the cap 4 made of the above-mentioned covering material is equipped with a ring-shaped iron-fitted packing 8 at the entrance end 10 of the cap, and this packing 8 fits into the opening of the cup. Sealing is achieved by engaging the ends.

In FIG. 5 showing an example of a sheist-off cap, a cap 4 made of the covering material is provided with an inwardly directed protrusion 11 corresponding to a discontinuous short screw thread at the bottle opening, and a cap 4 having an inward protrusion 11 on the inner surface of the cap. A sealing material 8 is provided.

The inclination of the thread causes the protrusion 11 of the cap to be pulled down to seal, and the opposite movement causes the cap to be unsealed. In FIG. 6, which shows an example of a honeycomb cap, a cap 4 made of the above-mentioned covering material is shaped to lightly cover the bottle opening, and a gasket 8 is provided at the portion that engages with the bottle opening.

Separately from the cap 4, a band 12 is provided for crimping and bonding the cap 4 to the pin opening, and this band 12 is provided with a stopper 13 for opening.
In FIG. 7 showing an example of a crown cap, the cap 4 made of the covering material has a skirt portion 14 having a large number of pleats around the skirt portion 14, and a packing 8 on the inner surface of the top plate. is provided, and sealing is achieved by tightening the pleats into the recesses of the bottle mouth.

In FIG. 8, which shows an example of a Bilfer Bruch cap, the cap 4 made of the covering material has a cap end 15 narrowed inward and shortened, leaving a bridging portion 16 and perforated. It has the same structure as the screw Z cap described above except that the cap 17 is formed, and the cap is opened by threading off the bridge portion 16.

In FIG. 9, which shows an example of the can-end, the bonito lid 4 made of the covering material has a plurality of expansions to relieve the pressure Z within the rope and to reinforce the can-end itself.
It has a ring 21, and the flange 23 of the hammer body 22 and the side part 24 of the bonito cover 4 are sealed by double seaming.

This bonito cover 4 is equipped with a well-known easy oven.
We were able to set up two. FIG. 10 shows an example of a bonito lid equipped with such an easy opener.

In FIG. 10, this key cover 4 is provided with an opening tab 226 formed by pressing the material of the cover 4 itself or via a pet 25. Further, the bonito lid 4 is provided with an opening score 27 on the inside of its seaming portion. Thus, when unsealing, by lifting the unsealing tab 26 upward, the score 27 is destroyed and the fin lid 4 is easily opened. The polyester or polyester ether coating layer used in the present invention has the remarkable advantage that it does not peel off from the metal material even during the above-mentioned pet processing and scoring processing, and the corrosion resistance of the bonito lid is maintained. be. According to the present invention, in the case of any of these container lids, the metal material of the container lid is coated with a corrosion-resistant polyester or polyester ether paint, and even when the container lid comes into contact with the food content, the metal material of the container lid is The flavor of the food contents will not deteriorate due to rust on the lid or elution of metal or paint components into the food contents.

Moreover, this protective coating film is maintained in its perfect form without damage or peeling even when the metal material is subjected to drawing, pressing, beading, rolling, rolling, etc. Moreover, the polyester or polyester ether used in the present invention has elasticity and flexibility properties necessary for packing and sealing materials, and by applying this material to a predetermined thickness, special packing can be achieved. It can eliminate the trouble of rubbing. Furthermore, when a separate packing is applied to the inner surface of the container lid, the aforementioned polyester or polyester ether exhibits excellent adhesion to these packings, avoiding the drawback of separation from the cap in the hopper of the filling machine cap. It can be resolved. The invention is illustrated in the following examples.

Example 1 Polytetramethylene terephthalate (molecular weight about 1500), polytetramethylene IJ col (molecular weight about 1500), and polypropylene glycol (molecular weight about 800) shown in Table 1 were heated in a nitrogen stream for 250 min in the presence of a small amount of catalyst.
Polyester ether obtained by block copolymerization at ~260 pm for 2 hours (intrinsic viscosity and glycol component (mol)
Table 1 shows the percentage of the tetramethylene glycol component (in moles) relative to the total amount of the tetramethylene glycol component (the percentage of the tetramethylene glycol component (moles) is shown in Table 1).

Table 1 No. 1 shown in Table 1 was applied to both surfaces of a 0.24 thick willow steel plate. 1~
No. The films of Comparative Example 1 and Comparative Example 1 were coated and bonded at 250 qo.

Furthermore, as Comparative Example 2, an epoxy/suria paint was applied to both surfaces of the steel plate and baked to a coating amount of 9/d of 55. Using this material, mayonnaise and tomato ketchup were filled dropwise into a screw cap formed into the shape shown in FIG. 2, and the state of rust was observed after storage at 50q0 for one week.

Table 2 evaluation ◎: No rust observed.

○: Slight rust spots are observed.

△: Rust is observed in the processed part.

×: Bells are observed on the entire surface including the unprocessed part.

From the results in Table 2, the screw cap of the present invention showed good results in all test items, and glycol component (mol)
Particularly excellent results were shown when the percentage of the tetramethylene glycol component (mol) was 55% or more (Experiments No. 1 to No. 4).

Example 2 Polytetramethylene glycol (molecular weight approximately 1200) 2
8.8 parts, polyethylene glycol (molecular weight approximately 800
) 8.8 parts, 36 parts of 1.4 tetramethylene glycol,
A polyester ether synthesized by transesterification and condensation from 62.1 parts of dimethyl terephthalate (intrinsic viscosity: 1.7 ml; tetramethylene glycol component (mol) relative to glycol component (mol): 80 mol%) was added to a T-die. 2 on a chromic acid phosphate treated steel plate with a thickness of 0.28
It was coated with 50 qo and molded into the crown shown in FIG.

Furthermore, vinyl phenol paint was applied to the inner surface of the same substrate with a thickness of 70 mm, and epoxy shester paint was applied to the outer surface of the same substrate with a thickness of 9 mm/d.

From the results in Table 3, it can be seen that the crown of the present invention is superior to the comparative example. Table 3 Example 3 A 30-layer thick film of a copolyester (intrinsic viscosity: 1.85) consisting of dibasic acid consisting of 95 parts of terephthalic acid and 5 parts of isophthalic acid and equimolar 1.4 tetramethylene glycol was coated on a plate. Both sides of a twice-cold-rolled electrolytically chromic acid-treated steel plate having a thickness of 0.29 mm were coated and crimped at 260 mm, and formed into a fully open lid having a diameter of 211 mm as shown in FIG. 11 using a conventional method.

After filling a squeeze can with diameter 211 and height 101 with Vienna sausage in the usual way, double-wrap it with this lid, and add 6 to 370.
As a result of storage for several months, no change was observed in the preservability or sealability of the contents, and the can could be opened easily.

Example 4 Polytetramethylene terephthalate having an intrinsic viscosity of 1.75 was made into a 25mm thick film, and this film was made into a 25mm thick film.
The inner surface of a twice-cold-rolled phosphate-treated steel plate having a thickness of 26 mm was coated and bonded at 250 mm to form a can lid having a thickness of 20 mm as shown in Fig. 10.

This was double-sealed to a 202 warp can body and stored at 50°C with a 95% R seal for one month, but no rust was observed. Example 5 Polytetramethylene glycol (molecular weight approximately 1500) 3
5. $ part, polyethylene glycol (molecular weight approximately 800)
29.1 parts, 1.4 tetramethylene glycol 66.1
99.8 parts of dimethyl terephthalate were transesterified;
Polyester ether synthesized by condensation (intrinsic viscosity: 1.70; percentage of tetramethylene glycol component (mol) relative to glycol component (mol): 65%) was extruded into a film with a thickness of 40 r using a film forming machine equipped with a T-die. It was melt-bonded to both sides of the electrolytic chromic acid treated steel plate on the 0.3 side.

This was formed into a mountain cup for an aerosol can. This is then clinched into a regular aerosol can using standard methods.
When filled with insecticide and stored at 4yo for 6 months, it showed excellent sealing performance and corrosion resistance.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of the coated metal material used in the present invention, FIG. 2 is a partially sectional side view of the container lid of the present invention in the form of a screw cap, and FIG. 3 is a paper vacuum Fig. 4 is a partially sectional side view of a container lid of the invention in the form of a cap; Fig. 4 is a partially sectional side view of a container lid of the invention in the form of an anchor cap; Fig. 5 is a twist-off side view; Figure 6 is a partial sectional side view of a container lid according to the invention in the form of a cap; Figure 6 is a side view, partly in section, of a container lid according to the invention in the form of a Hanex cap; Figure 7 is a crown cap; FIG. 8 is a partial cross-sectional side view of a container lid of the present invention in the form of a Bilfer-Brug cap; FIG. Fig. 10 is a perspective view of a container lid in the form of an easy-oven type lid, in which 1 is a metal material, and 2 and 2' are made of a specific polyester or polyester. A coating layer made of ether, 3 is a coating material, 4 is a cap, and 8 is a packing. 2 times soup 3 times soup 5 times soup 6 times 7 times soup 8 times soup 9 times oh 0

Claims (1)

[Claims] 1. Intrinsic viscosity measured at 30° C. at a concentration of 1.0 g/100 ml in orthochlorophenol is 0.7 to 2.
8 and at least 45 mol% of the glycol component, including those contained in the form of polyether glycol components, consists of tetramethylene glycol and at least 66 mol% of the dibasic acid component consists of terephthalic acid. A container lid characterized in that it is formed by drawing or press-forming a foil-like or sheet-like metal substrate coated with thermoplastic polyester or polyester ether into the shape of the lid.