JP5326372B2 - Film for laminating metal sheets - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film for laminating to a metal sheet, which is applicable to a laminate film for a two-piece can and excellent in forming processability in manufacturing cans and in superior flavor properties of beverages, and to provide a film-laminated metal sheet and a film-laminated metal container. <P>SOLUTION: The film for laminating to a metal sheet is composed of a thermoplastic polyester resin composition, wherein a melting point is 240-252&deg;C and a content of a &ge;2C alkylene oxide unit derived from a polyoxyalkylene glycol component is 2-20 mol% based on the total acid quantity of the polyester resin composition. In the film for laminating to a metal sheet, the coefficient of dynamic friction on the film surface, measured by using a steel ball under a load of 2 kg in a 150&deg;C environment as a slider after remelting the film stuck to a metal base body by heat of 270&deg;C and quenching it rapidly, is 0.20 or lower. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a thermoplastic resin film suitable for a resin-coated metal plate. In particular, the present invention relates to a thermoplastic resin film that is suitably used for coating the outer surface of a drawn iron can. More specifically, the present invention relates to a film for covering the outer surface of a drawn and ironed can excellent in canning processability such as drawing and ironing.

  As a method for preventing corrosion of the inner wall surface and the outer wall surface of a metal can, there is a method of laminating a thermoplastic resin film. A polyester film for laminating a metal material for food canning is disclosed (for example, see Patent Document 1 and Patent Document 2).

  This polyester film has excellent scratch resistance. For example, in a can manufacturing process in which a metal plate is formed into a cylinder and a lid is wound around the upper and lower openings of the cylinder, Hereinafter, when the laminate metal plate is processed by transferring a film) or when the laminate metal plate is processed by winding or the like, there is no need to cause scratches and reduce the commercial value.

  In addition, this film has excellent resistance at the time of squeezing processing, and after being filled with food after canning, the amount of oligomer elution is small when heated hot water treatment such as retort treatment is performed, so it is laminated on the inner wall surface of a metal container. Excellent as a polyester film.

  However, these films have high haze, are inferior in transparency, and have problems in film properties after canning, particularly corrosion resistance.

  By the way, for food cans, in addition to the so-called three-piece cans, which are formed by cylindrically forming a metal plate, a lid is attached to the upper and lower openings of the metal cylinder, and a metal plate is deep-drawn to form a container part. In addition, there is a so-called two-piece can formed by winding a lid on the upper surface opening of the container.

In the case of a three-piece can, the film-laminated metal plate is only formed into a cylindrical shape, but in the case of a two-piece can, the film-laminated metal plate is formed by drawing and ironing.
Therefore, in order to be applicable to a two-piece can, it is necessary to have good formability of being formed following the formation of a metal plate and to have excellent adhesion to the metal plate. If the formability is insufficient or the film adheres poorly to the metal plate, a so-called delaminating phenomenon occurs in which the film peels off from the metal plate, or the film is produced during the production of the container part of a two-piece can. Because it will be torn.

  Furthermore, in the drawing process, the film laminated metal plate is processed into a container shape while repeatedly raising and lowering the punch. Therefore, in the case of a film laminated on the inner wall surface side of the container, releasability from the punch is required. The In the case of the outer wall surface of a container, the temperature at the time of canning tends to rise due to the friction temperature due to the material and thickness of the metal plate, and the heat resistance temperature of the film may be exceeded. Since there is a problem of deteriorating canability, it is necessary to have excellent releasability from the die.

Up to now, it has been made of a polyester composition having a melting point of 220 to 250 ° C. mainly composed of a copolymer polyester composed of an ethylene terephthalate component and an ethylene isophthalate component, and has a density of less than 1.385 g / cm ³ and a plane orientation coefficient of 0.00. A biaxially oriented polyester film that is less than 130, wherein the polyester composition is derived from the polyoxyalkylene glycol component, wherein the polyoxyalkylene glycol component has 3 or more repeating alkylene oxide units having 3 or more carbon atoms. The alkylene oxide unit having 2 or more carbon atoms is contained in an amount of 2 to 20 mol% based on the total acid component of the polyester composition, and further 0.05 to 1.0 wt% of inert particles and wax. Metal plate bonding comprising a polyester composition containing 0.01 to 0.15% by weight Laminated polyester films are known (for example, see Patent Documents 3 and 4).

However, further improvement in can-making ability is required.
JP-A-7-227946 Japanese Patent No. 3248450 JP 2006-199915 A JP 2007-83709 A

  The object of the present invention has been made in view of such circumstances, and can be applied as a laminate film for a so-called two-piece can. An object of the present invention is to provide a film laminate metal plate and a film laminate metal container to be used.

The film for laminating a metal plate of the present invention that can achieve the above object has a melting point of 240 to 252 ° C., and an alkylene oxide unit having 2 or more carbon atoms derived from a polyoxyalkylene glycol component is a polyester resin composition. A film for laminating a metal plate comprising a thermoplastic polyester resin composition in an amount of 2 to 20 mol% based on the total acid amount of the film, and remelting the film existing on the metal substrate by heat at 270 ° C. A so-called remelt treatment), which is rapidly cooled and can-made, and has a dynamic friction coefficient of 0.20 or less on the surface of the film having a steel ball loaded with a load of 2 kg in a 150 ° C. environment as a slider, The film after the film is laminated on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled. Both the average molecular weight (A) and the weight average molecular weight (B) after the film existing on the metal substrate after being remelted by a heat of 270 ° C. (so-called remelt treatment), rapidly cooled and canned and processed can be 40,000. That is, the weight average molecular weights (A) and (B) after the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled. It is characterized by satisfying the relationship of the following formula 1.
(B) / (A) ≦ 1 (1)

  In this case, it is preferable to contain 0.01 to 1.0% by weight of an antioxidant in the thermoplastic polyester resin composition.

  In this case, the thermoplastic polyester resin composition preferably contains 0.05 to 2.0% by weight of inert particles.

  Furthermore, in this case, the film sampled from a can obtained by re-melting (so-called remelt treatment) the film present by bonding the film on a metal substrate with heat at 270 ° C. and rapidly cooling it. It is preferable that the 300% tensile strength of the material is in the range of 14N to 10N / 15 mm.

  Furthermore, in this case, a film laminated metal plate characterized by coating the thermoplastic polyester resin composition on a metal plate is useful.

  Furthermore, in this case, a drawn and ironed can characterized in that the film-laminated metal plate can be made is useful.

Furthermore, the metal plate laminating film of another invention that has achieved the above object is:
Thermoplastic having a melting point in the range of 240 to 252 ° C. and containing 2 to 20 mol% of an alkylene oxide unit having 2 or more carbon atoms derived from the polyoxyalkylene glycol component based on the total acid amount of the polyester resin composition A metal plate laminating film comprising a polyester resin composition, wherein the thermoplastic polyester resin composition has a weight average molecular weight (A) of 40,000 or more, and the thermoplastic polyester resin composition has an antioxidant of 0.0. It is characterized by containing 01 to 1.0% by weight, and the thermoplastic polyester resin contains 0.3 to 2.0% by weight of lubricant particles having an average particle size of 3 μm or more.

  Furthermore, another aspect of the invention is a laminated metal plate obtained by laminating a polyester film, wherein the film has a melting point in the range of 240 to 252 ° C., and is a polyoxyalkylene glycol. A thermoplastic polyester resin composition having a melting point in the range of 240 to 252 ° C. containing 2 to 20 mol% of the alkylene oxide unit having 2 or more carbon atoms derived from the components based on the total acid amount of the polyester resin composition The surface roughness of the center plane after the film existing on the metal substrate is remelted by 270 ° C. heat and rapidly cooled is 0.2 or more, and the film is pasted on the metal substrate. The weight average molecular weight (B) after the existing film was remelted by so-called heat at 270 ° C. (so-called remelt treatment) and rapidly cooled was 4 And it is characterized in that it is 000 or more.

  Furthermore, a metal can obtained by making the laminated metal plate can be suitable.

  When used as a laminate film for a two-piece can, the drawn and ironed can coating film of the present invention is excellent in moldability, in particular, releasability from a die when making cans, particularly an aluminum metal plate or a steel metal plate. It is useful for the squeezed iron used.

  It is preferable to use a thermoplastic polyester resin for the thermoplastic polyester resin composition used for the squeezed iron can coating film of the present invention from the viewpoints of heat resistance and aroma retention. Furthermore, it is preferable to use polyethylene isophthalate copolymerized PET.

Moreover, in the said thermoplastic polyester, it is preferable that a melting peak exists in the range of 240 to 252 degreeC. If the melting peak is less than 240 ° C, the heat resistance and canability in the canning process are impaired, and if it exceeds 252 ° C, the temperature balance in the remelt treatment is lost and the yield is lowered, which is not preferable.
The polyethylene isophthalate copolymerized PET in the present invention is a polyester mainly composed of terephthalic acid and isophthalic acid as acid components.
Moreover, other copolymerization components can be included in the range which does not inhibit the purpose.
Among other copolymerizable components that can be used, dicarboxylic acid components include naphthalene dicarboxylic acid, diphenylsulfone dicarboxylic acid, aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, Aliphatic dicarboxylic acids such as decanedicarboxylic acid, maleic acid, fumaric acid and dimer acid, oxycarboxylic acids such as p-oxybenzoic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used.
The amount of the above dicarboxylic acids and their ester derivatives that can be used is preferably 10 mol% or less, more preferably 6 mol% or less, based on the total acid component amount. When the usage-amount of other dicarboxylic acid and those ester derivatives exceeds 10 mol%, the thermal stability of polyester will worsen and it is unpreferable.

As the glycol component of the polyethylene isophthalate copolymer PET of the present invention, components other than the ethylene glycol component include aliphatic glycols such as propanediol, butanediol, pentanediol, hexanediol and neopentylglycol, cyclohexane Aromatic glycols such as dimethanol, aromatic glycols such as ethylene oxide adducts of bisphenol A, ethylene oxide adducts of bisphenol S, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like can be used.
In addition, a small amount of a compound containing an amide bond, a urethane bond, an ether bond, a carbonate bond, or the like may be included. Here, the amount of other glycol components that can be used is preferably 10 mol% or less, more preferably 5 mol% or less, based on the total glycol components. If the amount of the other glycol component used exceeds 10 mol%, the thermal stability of the polyester deteriorates, which is not preferable.

  The method for producing the polyethylene isophthalate copolymer PET of the present invention is not particularly limited. That is, it can be used even if it is produced by either the transesterification method or the direct polymerization method. Further, it may be produced by a solid phase polymerization method in order to increase the molecular weight. In addition, the amount of oligomers from the polyester resin in the retort treatment etc. that is carried out after filling the can into the can is reduced, and from the standpoint of fragrance to prevent the content and flavor from deteriorating, From the viewpoint of preventing contamination, it is preferable to use a polyester having a low oligomer content produced by a solid phase polymerization method under reduced pressure or under an inert gas atmosphere.

  Here, for example, the content of the oligomeric cyclic trimer including ethylene terephthalate cyclic trimer is preferably 0.7% by weight or less.

  The intrinsic viscosity of the polyethylene isophthalate copolymerized PET of the present invention is preferably 0.6 to 1.2, more preferably 0.70 to 1.2. If the intrinsic viscosity is less than 0.6, the mechanical properties of the resulting film may be deteriorated, and even if the intrinsic viscosity exceeds 1.2, no further effect of improving the mechanical properties can be obtained. In addition, the productivity at the time of producing the polyester is lowered, which is not economical.

  In the production of polyethylene isophthalate copolymerized PET in the present invention, antimony oxide, germanium oxide, titanium compound and the like are used as a polymerization catalyst. In addition to the polymerization catalyst, a melt-extruded film using the polyester resin composition of the present invention. Mg salt such as magnesium acetate and magnesium chloride, Ca salt such as calcium acetate and calcium chloride, Mn salt such as manganese acetate and manganese chloride, zinc chloride and zinc acetate Zn salts such as cobalt chloride, cobalt salts such as cobalt acetate and the like, the total amount of each metal ion is 300 ppm or less, phosphoric acid or phosphoric acid ester derivatives such as phosphoric acid trimethyl ester and phosphoric acid triethyl ester as phosphorous atoms and 200 ppm or less It is also possible to add in a range. When the total amount of metal ions other than the above polymerization catalyst exceeds 300 ppm and the amount of phosphorus exceeds 200 ppm, not only is the resulting polyester colored significantly, but the heat resistance and hydrolysis resistance of the polyester may also decrease. Therefore, it is not preferable.

  At this time, when the molar ratio of the total phosphorus amount to be added and the total metal ion amount is 0.4 to 1.0, the polyester having the best balance of heat resistance, hydrolysis resistance, and electrostatic adhesion Is preferable. Here, molar ratio of addition amount = (total amount of phosphorus in phosphoric acid, phosphoric acid alkyl ester or derivative thereof (molar atom)) / (total amount of Mg ion, Ca ion, Mn ion, Zn ion, Co ion ( Mole atom)). When the molar ratio is less than 0.4, the composition of the present invention is markedly colored, and heat resistance and hydrolysis resistance are lowered. If it exceeds 1.0, sufficient electrostatic adhesion cannot be obtained.

The polyethylene isophthalate copolymerized PET synthesized as described above may be included in the polyester film only in one kind or in a mixture of two or more kinds.
Further, polyethylene isophthalate copolymerized PET having a high isophthalic component and PET resin may be mixed and used.

  The thermoplastic polyester resin composition of the present invention preferably contains a polyoxyalkylene glycol component having 3 or more repeating alkylene oxide units having 2 or more carbon atoms.

In the present invention, the amount of the polyoxyalkylene glycol component contained in the thermoplastic polyester resin composition is such that the amount of the alkylene oxide unit having 2 or more carbon atoms derived from the polyoxyalkylene glycol component is the amount of the polyester composition. It is preferable that it is 2-20 mol% with respect to all the acid components.
By containing the said component in the said range, the elasticity at normal temperature and low temperature of a thermoplastic polyester film can be provided, and shaping | molding adhesiveness with another resin layer can be improved. In particular, it is effective in improving the formability during drawing and ironing cans that are subjected to shock deformation at high speed.
Moreover, the process abnormality at the time of continuous production by the accumulation | storage of the chip | tip (whisker) by the tearability defect of the film at the time of can making can be prevented by making the said component into 2 mol% or more.
In addition, the amount of the polyoxyalkylene glycol component contained in the thermoplastic polyester resin composition is more preferably 2 to 10 mol%, and particularly preferably 3 to 6 mol%.
Examples of polyoxyalkylene glycols comprising alkylene oxide units having 2 carbon atoms include polyethylene glycol (2 carbon atoms), polytrimethylene glycol (3 carbon atoms), polytetramethylene glycol (4 carbon atoms), polyhexamethylene Glycol (6 carbon atoms) can be used, and one of these components may be used alone, or two or more components may be mixed and used. A polyoxyalkylene glycol having an average molecular weight in the range of 500 to 3000 can be suitably used, and an average molecular weight in the range of 800 to 2000 is more preferable.

  An alkylene oxide unit having 2 or more carbon atoms derived from a polyoxyalkylene glycol component means a structural unit in which both ends of an alkylene chain form an ether bond with an adjacent alkylene chain with an oxygen atom interposed therebetween.

  The method for containing the polyoxyalkylene glycol component in the thermoplastic polyester resin composition of the present invention is not particularly limited. For example, a polyester composition obtained by adding a polyoxyalkylene glycol component at the stage of producing a polyester composition of a resin layer in the same manner as other raw materials and then terminating the polyester synthesis reaction may be used. Another copolymerized polyester copolymerized with oxyalkylene glycol may be melt-mixed with the thermoplastic polyester resin of the present invention. In the present invention, the latter method of melt mixing is preferable because the effect of improving the moldability and tearability of the can is exhibited more efficiently. In particular, the polyalkylene terephthalate-polytetramethylene oxide block copolymer is melt-mixed. The method is the most preferred form.

In particular, as a method for adding a polyoxyalkylene glycol composed of an alkylene oxide unit having 2 carbon atoms to a polyester composition, for example, a method of adding a polyalkylene terephthalate-polytetramethylene oxide block copolymer to polyethylene terephthalate. can give. Examples of the polyalkylene terephthalate include polybutylene terephthalate, and polybutylene terephthalate is preferable.
At this time, the ratio of the polyoxyalkylene glycol in the block copolymer is preferably 20 to 60% by weight, and more preferably 30 to 50% by weight.

The film for covering a drawn iron can according to the present invention is a film for laminating a metal plate made of a thermoplastic polyester resin composition, and the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment). ) And then rapidly cooling, the dynamic friction coefficient of the film surface using a steel ball loaded with a load of 2 kg in an environment of 150 ° C. as a slider is preferably 0.20 or less, and further 0.15 μm or less. In particular, 0.12 μm or less is preferable.
This is for obtaining releasability from the die during can making. In a highly rigid metal plate such as a steel plate, the temperature at the time of canning tends to rise due to friction at the time of canning. Particularly in the case of an outer film, it is necessary to provide slipperiness at a high temperature to avoid this problem. Here, if the dynamic friction coefficient of the film surface using a steel ball loaded with a load of 2 kg in an environment of 150 ° C. exceeds 0.20, the releasability between the film and the die during can making decreases. As a result, the temperature of the can is raised, and as a result, scratches and galling occur with the die.
In order to obtain the above dynamic friction coefficient, the center surface average roughness (SRa) is preferably 0.2 μm or more, more preferably 0.30 μm or more, and particularly preferably 0.35 μm or more. Furthermore, the surface roughness after remelting is preferably set so that the maximum height (SRmax) is 4 μm or more.

  In order to achieve the above-mentioned film surface formation and to have a dynamic friction coefficient of 0.20 or less on the film surface using a steel ball loaded with a load of 2 kg in a 150 ° C. environment, an inert inorganic particle as a lubricant is used. It is preferable to use crosslinked polymer particles or the like.

  The average particle diameter of the particulate lubricant is preferably 3 to 7 μm, more preferably 4 to 7 μm, and particularly preferably 5 to 7 μm. This is because if it is less than 3 μm, the effect of improving the releasability from the die cannot be exhibited. On the other hand, if the thickness exceeds 7 μm, the effect of improving the releasability with the die is saturated, but the lubricant is dropped due to wear, and the film forming property is lowered at the time of film formation, which is not economical.

  The amount of lubricant is preferably 0.05 to 2.0% by weight, more preferably 0.3 to 2.0% by weight, and 0.4 to 1.0% by weight. % Is particularly preferred. This is because a lubricant amount of 0.3% by weight or more is preferable in order to make the dynamic friction coefficient in a 150 ° C. environment 0.20 or less. On the other hand, even if the content exceeds 2.0% by weight, the effect of releasability does not change, and the film-forming property is lowered during film formation, which is not economical.

  Examples of the inert particles include silica, alumina, kaolin, clay, titanium oxide, calcium phosphate, calcium carbonate, lithium fluoride, barium sulfate, and carbon black.

Examples of the crosslinked polymer particles include acrylic monomers such as acrylic acid, methacrylic acid, acrylic acid esters and methacrylic acid esters, styrene monomers such as styrene and alkyl-substituted styrene, and divinylbenzene. , Divinyl sulfone, ethylene glycol dimethacrylate, trimethylolpropane trimethyl acrylate, copolymers with crosslinkable monomers such as pentaerythritol tetramethyl acrylate; melamine resin; benzoguanamine resin; phenol resin; silicon-containing resin Etc. can be exemplified.
Among the above, cross-linked particles made of a copolymer of silica particles, methacrylic acid esters and cross-linkable monomers such as divinyl benzene, divinyl sulfone, ethylene glycol dimethacrylate, trimethylolpropane trimethyl acrylate, pentaerythritol tetramethyl acrylate, etc. (Crosslinked PMMA particles and the like) are preferable in terms of can manufacturing ability. In particular, crosslinked particles made of a copolymer of a methacrylic acid ester and a crosslinking monomer such as divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate, trimethylolpropane trimethyl acrylate, pentaerythritol tetramethyl acrylate, etc. As compared with other particles having the same dynamic friction coefficient on the surface of the film having a steel ball loaded with a load of 2 kg as a slider, the can-making property is excellent.

  The squeezed iron can coating film of the present invention preferably contains 0.01 to 1% by weight of an antioxidant, and more preferably 0.05 to 0.50% by weight. This is because the film is bonded to a metal substrate, and the molecular weight of the film is prevented from lowering in the remelting process (so-called remelt treatment) and the can making process by heat higher than the melting point of the film. In particular, the polyalkylene glycol component is susceptible to thermal decomposition, and if the antioxidant is less than 0.01% by weight, the molecular weight is greatly reduced in the lamination / remelt treatment step. Moreover, even if it contains 1 weight% or more, an effect does not change and it becomes disadvantageous in cost. This is because the thermal decomposition of the polyoxyalkylene glycol component contained in the thermoplastic polyester resin composition is linked to the entire thermoplastic polyester resin component.

In the present invention, the weight average molecular weight (A) after the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled is 40,000 or more. Is preferable because the weight average molecular weight of the thermoplastic polyester resin composition after remelting is maintained at a level that can withstand can making.
Further, at this time, the weight average molecular weight (B) after the film existing on the metal substrate is remelted by a heat of 270 ° C. (so-called remelt treatment), rapidly cooled and canned, is 40000 or more. This is preferable as a specific numerical range in reducing galling and blurring after canning.
The film used in the present invention as described above is bonded to a metal substrate, and the film existing in the film is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled, and the weight average molecular weight (A ), And the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment), rapidly cooled and canned, and the relationship of the weight average molecular weight (B) is expressed by the following formula ( It is preferable to satisfy 1), and those whose molecular weight is rather increased by remelting are not suitable.
(B) / (A) ≦ 1 (1)

  Antioxidants used in the film for squeezing and ironing can coating of the present invention include primary antioxidants (which have a phenol-based or amine-based radical scavenging and chain termination action), and secondary antioxidants (this Have a phosphorus decomposition action such as phosphorus-based and sulfur-based), and any of these can be used. Specific examples include phenolic antioxidants (eg, phenol type, bisphenol type, thiobisphenol type, polyphenol type, etc.), amine antioxidants (eg, diphenylamine type, quinoline type, etc.), phosphorus antioxidants (eg, For example, phosphite type, phosphonite type, and the like) and sulfur-based antioxidants (for example, thiodipropionic acid ester type and the like). Specifically, n-octadecyl-β- (4′-hydroxy-3,5′-di-t-butylphenyl) propionate, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-) 4′-hydroxyphenyl) propionate] (which is commercially available as “Irganox 1010” (trade name)), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) ) Butane, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -S-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3, 5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene (which is commercially available as "Irganox 1330" (trade name)), tris ( mix Mono and / or dinonylphenyl) phosphite, cyclic neopentanetetrayl bis (octadecyl phosphite), tris (2,4-di-t-butylphenyl phosphite), 2,2-methylene bis (4,6- And di-t-butylphenyl) octyl phosphite, di-lauryl-thiodipropionate, di-myristyl-thiodipropionate, and di-stearyl-thiodipropionate. These antioxidants may be used alone or in combination of two or more.

  In the squeezing and ironing can coating film of the present invention, it is preferable that the content of the low molecular weight compound is smaller in view of the antifouling property of the can manufacturing line and the fragrance retention property in the case of the inner surface of the can. For example, the ethylene terephthalate cyclic trimer content in the thermoplastic resin after canning in the present invention is preferably 0.7% by weight or less. In the case of producing a two-piece can, after undergoing a remelt process for making the film non-oriented, after being drawn, the beverage is filled and subjected to a heat treatment such as a retort process. This is to prevent the oligomer from being eluted from the film in each step, and further transferring the oligomer to the beverage and adversely affecting the taste and flavor of the beverage.

The method for setting the content of the cyclic trimer including the ethylene terephthalate cyclic trimer in the polyester film to 0.7% by weight or less is not particularly limited. 1. a method of extracting and removing the cyclic trimer from the laminated film with water or an organic solvent after the laminated film is formed; Examples thereof include a method of forming a polyester film using a polyester having a small cyclic trimer. Of these, 2. This method is more economical and preferable.
2. In this method, the method for producing a polyester having a low cyclic trimer content is not limited, and the solid phase polymerization method: after polymerization, the cyclic trimer is extracted by heat treatment under reduced pressure or by extraction with water or an organic solvent. A removal method; and a combination of these methods. In particular, after producing a polyester having a low cyclic trimer content by solid phase polymerization, the method of extracting the obtained polyester with water to further reduce the cyclic trimer is the cyclic trimer in the film forming step. This is most preferable because the amount of body produced is suppressed.

  The intrinsic viscosity of the polyester film when the above various components are mixed is preferably in the range of 0.6 to 1.2, and more preferably 0.7 to 1.2. If the intrinsic viscosity of the polyester is less than 0.6, the mechanical properties of the resulting film may be lowered. If the polyester exceeds 1.2, the effect of the mechanical properties will not change, and the productivity of the raw material polyester will also be improved. It is not economical because it decreases.

  The film of the present invention may be a biaxially stretched film or an unstretched film. Here, the biaxial stretching method may be any of sequential biaxial stretching, simultaneous biaxial stretching, or a combination thereof. In the case of successive biaxial stretching, generally, a method of stretching in the longitudinal direction and then stretching in the transverse direction is adopted, but a method of stretching in the reverse order may be employed. In addition, it is preferable to fix the orientation of the polyester by heat treatment after biaxial stretching, but after biaxial stretching, re-stretching may be performed in the longitudinal direction and / or the width direction before the heat treatment step. Furthermore, the corona discharge treatment is not limited at all on one side or both sides of the film before or after the stretching step.

  The method for laminating the film of the present invention on a metal plate is not particularly limited. For example, a dry lamination method or a thermal lamination method can be employed. Specifically, the metal plate is heated above the melting point of the laminate surface of the film, the film is brought into contact with the surface of the metal plate, and the nip roll is passed in this state. Subsequently, it laminates by making it cool and solidify in a 10-40 degreeC water tank.

  The film lamination may be performed on only one side of the metal plate or on both sides. In the case of double-sided lamination, it may be laminated at the same time or sequentially.

When the biaxially stretched film laminated metal plate in the present invention is applied to a two-piece can, a remelt treatment in which, after laminating, heating is performed at a temperature equal to or higher than the melting point of the polyester constituting the film, followed by rapid cooling in order to remove the polyester orientation. Is preferably performed. The degree of orientation by X-ray observation after the remelt treatment is 10% or less, which can be said to be substantially non-oriented. In other words, a biaxially stretched film in which the polyester is in an oriented state is difficult to be plastically deformed or stretched, making it difficult to perform a drawing process for forming the container portion. This is because the delaminating phenomenon of peeling off occurs, torn or torn. On the other hand, if it is substantially non-oriented, it can follow the deformation of the laminated metal plate, so that it can be molded with plastic deformation of the metal like a two-piece can without delaminating or tearing. Because it can.
In that case, in order to set the film strength after remelting in the range of 14N to 10N / 15 mm, it is preferable to set the isophthalic component in the range of 0.5 to 1.5 mol%. When the film strength is less than 10 N / 15 mm, so-called blur occurs, and when it exceeds 14 N, molding defects occur, and the yield decreases.

  The film laminated metal container of the present invention is a metal container formed by appropriately forming the biaxially stretched type or non-oriented type film laminated metal plate of the present invention, and the shape of the container, the method of forming the metal container, There is no particular limitation. Specifically, a so-called three-piece can in which the top cover is wound and filled with the contents, as well as a two-piece can that is formed by drawing a metal plate to form a container portion can be used.

  In the metal container of the present invention, the polyester film of the present invention may be molded so as to be on the inner wall surface side of the metal container, or may be molded so as to be on the outer wall surface side.

In addition, when carrying out drawing ironing, you may apply | coat a lubricant to the film surface which a punch and die | dye contact as needed.
The film-laminated metal container of the present invention may be subjected to printing or the like as necessary, and may be subjected to a re-melt process after the can making process or the printing process.

  In addition to the additives and lubricants mentioned so far, the film in the present invention may contain an ultraviolet absorber, a plasticizer, a pigment, an antistatic agent, a lubricant, a crystal nucleating agent, etc. as necessary. May be.

  In the present invention, the metal plate is not particularly limited, but a surface-treated steel plate such as tin free steel, an aluminum plate, an aluminum alloy plate, an aluminum plate or a surface-treated aluminum plate, or the like can be used.

  Hereinafter, the present invention will be described based on examples.

Various evaluation methods in the present invention are shown below.
(1) Dynamic friction measurement using a steel ball as a slider in a 150 ° C environment (steel ball μ)
Three steel balls (according to JIS B1501 standard. Diameter 12.7 mmΦ) are arranged and fixed in a triangular shape at a measurement point of the remelt aluminum plate at a distance of 25 mm each in a triangular shape. A slider (weight = 2.0 kg) was set so as to be in contact with the measurement point at three points (one point at each vertex of each steel ball), and the dynamic friction coefficient when sliding at 200 mm / min was measured.

(2) Center surface average roughness The remelt film of the remelt aluminum plate was measured using a surface roughness measuring instrument (Surfcorder ET-30HK, manufactured by Kosaka Laboratory).
Here, the central plane means a plane in which the sum of squares of the deviation between the plane and the cross-section curved surface is equal to the top and bottom and is the minimum.
The center plane average roughness is represented by SRa, the orthogonal coordinate axes X and Y axes are placed on the center plane of the roughness curve, the axis orthogonal to the center plane is the Z axis, and the roughness aspect is f (x, y). When the reference plane sizes Lx and Ly are used, the values given by the following formulas are meant.
SRa = 1 / (Lx × Ly ) ∫ 0 Lx ∫ 0 Ly | f (x, y) | dx · dy

(3) Molecular weight of film 2 mg of the film was sampled. Each was immersed in 0.4 ml of HFIP / chloroform = 2/3 (v / v), dissolved, and then adjusted to 8 ml with chloroform. It filtered with the 0.2 micrometer membrane filter, and used the filtrate for GPC.
Equipment: TOSOH HLC-8220GPC
Column: TSKgel SuperHM-H × 2 + TSKgel SuperH2000
(TOSOH)
Solvent: chloroform / HFIP = 98/2 (v / v),
Flow rate: 0.6 ml / min
Concentration: 0.025%
Temperature: 40 ° C
Detector: UV 254nm
The molecular weight was calculated in terms of standard polystyrene (PS).
In the case of a remelt metal plate or a can-made product, the aluminum was removed by hydrochloric acid treatment, and only the film was separated to obtain a sample.
In Tables 1 and 2, the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled, the molecular weight of the film is molecular weight A, can product The molecular weight of the film is expressed as molecular weight B.

(4) Inert particle amount of polyester Cut out as a sample. Using a fluorescent X-ray device (device name: ZSX100e) manufactured by Rigaku Corporation, each sample was measured from the upper and lower surfaces with an analysis diameter of 30 mmΦ, and converted to the amount of inert particles using a calibration curve for PET.

(5) Average particle diameter of inert particles The coating film sample dried overnight in a vacuum dryer is subjected to ion plasma etching, and the inert particles contained in the (I) and (II) layers of the base film. The particles were exposed. Subsequently, using a scanning electron microscope (SEM), the magnification was appropriately changed according to the size of the particles, and photography was performed. The equivalent circle diameter of at least 100 particles or more was obtained with an image processing apparatus, and divided by the number of particles to obtain a number-based average particle diameter (μm). When the contrast of the photographed particle was weak, the outline of the particle was traced on the OHP film with an ultra-fine magic pen, and the equivalent circle diameter of the particle was obtained with the image processing apparatus.
In addition, powder particles before adding particles to polyester are coated with a double-sided tape on a SEM sample table, and the powder is thinly deposited thereon. After carbon deposition, the particle size is measured using a scanning electron microscope (SEM). In accordance with this, the magnification was appropriately changed to take a picture. The equivalent circle diameter of at least 100 particles or more was obtained with an image processing apparatus, and divided by the number of particles to obtain a number-based average particle diameter (μm).

(6) Can-making ability (scratch)
After the laminated metal plate is formed into a cup by drawing, 300 cans can be continuously made by redrawing and ironing under the following forming conditions at a speed of 80 cans / minute, and the degree of galling occurring on the outer surface of the formed can is visually observed. The ratio of the number of generated cans was set as the following evaluation criteria, and ○ was evaluated as practical.
As used herein, galling occurs during can making, is caused by contact between the outer surface of the forming can and the forming jig, and is often linear.
○: Scratch generation rate of the outer surface of the can 5% or less Δ: Scratch generation rate of the outer surface of the can 30% to 6%
X: Scratch generation rate of outer surface of can 31% or more (molding conditions) Blank diameter: 152 mm, drawing ratio: 1.60, redrawing ratio: 1.44, ironing rate of can body side wall: 56% [however, ironing rate (T ₀ −t ₁ ) / t ₀ × 100, t ₀ : thickness before processing, t ₁ : calculated from the thickness of the can barrel side wall after processing]
It was drawn and ironed.

(7) Can manufacturing (blur)
The presence or absence of thin glossy blur generated on the outer surface of the molded can of the sample obtained in (5) above was visually observed, the ratio of the number of generated cans was set as the following evaluation criteria, and ○ was evaluated as practical.
The glossy blur here is generated at the time of can making, and is caused by contact between the outer surface of the molded can and the molding jig, and is often dotted.
○: Blur occurrence rate on the outer surface of the can 5% or less Δ: Blur occurrence rate on the outer surface of the can 30% to 6%
×: Bokeh occurrence rate of can outer surface is 31% or more

(8) 300% elongation strength The metal part was dissolved and removed with dilute hydrochloric acid from the can subjected to the treatment of (5) above, and only the film was taken out. Under an environment of 23 ° C., the tensile strength was measured in the transverse direction of the film at a tensile speed of 200 mm / min using a tensile tester. From this breaking curve, the strength at 300% elongation was obtained.

Next, the kind and content of polyester used for the Example and the comparative example are demonstrated.
A: Polyethylene terephthalate (IV = 0.73)
82 parts by weight of ethylene glycol (ethylene glycol / terephthalic acid molar ratio = 2) with respect to 100 parts by weight of terephthalic acid in a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade .2) 0.05 mol% of germanium oxide as the Ge element and 0.05 mol% of magnesium acetate as the Mg element are charged with respect to the acid component, and nitrogen is introduced while stirring to bring the pressure in the system to 0.3 MPa. The esterification reaction was carried out while distilling out the water produced at a temperature of 230 ° C. to 250 ° C. outside the system. After completion of the reaction, 0.04 mol% of trimethyl phosphate as P amount was added at 250 ° C., the pressure was gradually reduced while the temperature was raised, and a polycondensation reaction was performed under a vacuum of 275 ° C. and 1.0 hPa or less. The obtained intrinsic viscosity 0.73 polyester (PET) resin was used.
B: Polyethylene terephthalate / isophthalate (10 mol% of ethylene isophthalate repeating unit, IV = 0.74, 0.5% by weight of ethylene terephthalate cyclic trimer).
90 parts by weight of terephthalic acid, 10 parts by weight of isophthalic acid, 82 parts by weight of ethylene glycol (ethylene glycol / total acid component) were added to a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade. Molar ratio = 2.2), 0.05 mol% of germanium oxide as the Ge element and 0.05 mol% of the magnesium acetate as the Mg element are charged with respect to the acid component, and nitrogen is introduced with stirring to introduce pressure in the system. Was maintained at 0.3 MPa, and the esterification reaction was carried out while distilling off the water produced at a temperature of 230 ° C. to 250 ° C. out of the system. After completion of the reaction, at 250 ° C., 0.04 mol% of trimethyl phosphate is added as the P amount, the pressure is gradually reduced while the temperature is raised, and a polycondensation reaction is performed under a vacuum of 275 ° C. and 1.0 hPa or less. Obtained. Subsequently, this polyester was heat-treated at 200 ° C. under a vacuum of 1.0 hPa for 12 hours to obtain PET-I (10). The polyester obtained had an intrinsic viscosity of 0.74 (dl / g) and an ethylene terephthalate cyclic trimer of 0.5% by weight.
C: Polytetramethylene terephthalate-polytetramethylene oxide block copolymer polyester In a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade, with respect to 100 parts by weight of dimethyl terephthalate , 75 parts by weight of 1,4-butanediol, 75 parts by weight of polytetramethylene glycol (average molecular weight 1000), and 0.05 parts by weight of normal butyl titanate were distilled out of the system at 190 ° C. to 230 ° C. The transesterification reaction was carried out. After completion of the reaction, 0.05 part by weight of tetranormal butyl titanate and 0.025 part by weight of phosphoric acid were added, and a polycondensation reaction was performed at 250 ° C. under reduced pressure (1.0 hPa or less). Polytetramethylene terephthalate-polytetramethylene oxide block copolymer, polytetramethylene oxide ratio 40% by weight, intrinsic viscosity 0.75). (Brand GP301 manufactured by Toyobo)
D: Polyester containing 5% by weight of antioxidant 5 parts by weight of phenolic antioxidant (Irganox 1010, manufactured by Ciba Geigy) is melt-kneaded with 95 parts by weight of polyester A, and oxidized. A polyester resin (D) containing 5% by weight of an inhibitor was obtained.
E: Lubricant masterbatch (1)
With respect to 90 parts by weight of polyester A, 10 parts by weight of SiO _{2 having} an average particle diameter of 5 μm was melt-kneaded with a twin-screw extruder to obtain a polyester resin (E) containing 10% by weight of SiO ₂ .
F: Lubricant masterbatch (2)
With respect to 90 parts by weight of polyester A, 10 parts by weight of crosslinked PMMA having an average particle size of 5 μm was melt-kneaded with a twin screw extruder to obtain a polyester resin (F) containing 10% by weight of crosslinked PMMA.
G: Lubricant masterbatch (3)
10 parts by weight of SiO _{2 having} an average particle size of 3 μm was melt-kneaded with 90 parts by weight of polyester A using a twin screw extruder to obtain a polyester resin (G) containing 10% by weight of SiO ₂ .
H: Lubricant master batch (4)
With respect to 90 parts by weight of polyester A, 10 parts by weight of SiO _{2 having} an average particle diameter of 2 μm was melt-kneaded by a twin screw extruder to obtain a polyester resin (G) containing 10% by weight of SiO ₂ .

Example 1
[Production of polyester film]
After drying polyester A / B / C / D / E = 32/50/4/4/10 (wt%) as a raw material at 100 ° C. for 24 hours and melting at 270 ° C. using a single screw extruder, An unstretched sheet was obtained by extruding onto a cooling roll in layers from a T die. The unstretched sheet was stretched 3.3 times in the machine direction at a preheating temperature of 80 ° C. and a stretching temperature of 100 ° C., and further stretched by 3.7 times in the transverse direction at a preheating temperature of 80 ° C. and a stretching temperature of 100 ° C. A polyester film having a thickness of 10 μm was obtained by heat treatment at 8 ° C. for 8 seconds.

[Production of film-laminated metal plate]
After being laminated between the nip rolls so that the polyester film and the aluminum plate produced above are in contact with both surfaces of the preheated aluminum plate, heat treatment is performed, and immediately after that, it is rapidly cooled in a 10-40 ° C. water bath, An aluminum plate having films laminated on both sides was obtained. At the time of laminating, there was no initial adhesion, tension fluctuation, winding around a nip roll, etc., and the laminating suitability of the laminated film of this example was good.
Next, the film-laminated aluminum plate was subjected to 90 Sec heat treatment at 270 ° C. and then air-cooled and further quenched in water to prepare a remelt aluminum plate. In remelting, there was no reduction in molecular weight, and a remelting plate having a good dynamic friction coefficient using a steel ball as a slider under an environment of 150 ° C. was obtained.

[Production of film-laminated metal container]
The remelted aluminum plate produced above was drawn and ironed so that the thickness reduction rate was 30% to form a film laminated metal container. The obtained can product had no film molecular weight reduction, a good dynamic friction coefficient using a steel ball in a 150 ° C. environment as a slide, no galling or tearing on the outer surface, and excellent can manufacturing performance.

(Example 2)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 1 except that polyester A / B / C / D / F = 32/50/4/4/10 (% by weight) is used as a raw material.
As in Example 1, the resulting can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, and there was no galling or tearing on the outer surface, and the can product was excellent.

(Example 3)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 1 except that polyester A / B / C / D / G = 32/50/4/4/10 (wt%) as a raw material.
As in Example 1, the resulting can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, and there was no galling or tearing on the outer surface, and the can product was excellent.

Example 4
The subsequent film-forming / can-making process and evaluation are the same as in Example 1 except that polyester A / B / C / D / E = 52/30/4/4/10 (wt%) as a raw material.
As in Example 1, the resulting can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, and there was no galling or tearing on the outer surface, and the can product was excellent.

(Example 5)
The subsequent film-forming / can-making process and evaluation are the same as in Example 1 except that polyester A / B / C / D / E = 34/50/5/1/10 (% by weight) is used as a raw material.
As in Example 1, the resulting can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, and there was no galling or tearing on the outer surface, and the can product was excellent.

(Comparative Example 1)
The subsequent film-forming / can-making process and evaluation are the same as in Example 1 except that polyester A / B / C / D / H = 32/50/4/4/10 (weight%) as a raw material.
Although the resulting beverage can did not have a decrease in molecular weight or the like, galling frequently occurred at the time of can making, and did not reach the quality in the examples.

(Comparative Example 2)
Example 1 for the subsequent film-forming / can-making process and evaluation, except that polyester A / B / C / D / E = 41.7 / 50/4/4 / 0.3 (wt%) was used as a raw material. According to
Although the resulting beverage can did not have a decrease in molecular weight or the like, galling frequently occurred at the time of can making, and did not reach the quality in the examples.

(Comparative Example 3)
Example 1 for the subsequent film-forming and can-making processes and evaluations except that polyester A / B / C / D / E = 35.9 / 50/4 / 0.1 / 10 (% by weight) was used as a raw material. According to
The resulting beverage can had a decrease in molecular weight, resulting in a decrease in can-making ability, and did not reach the quality in the examples.

(Comparative Example 4)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 1 except that polyester A / B / C / D / E = 0/76/4/4/10 (% by weight) as a raw material.
The resulting beverage can had a lower melting point, so that the can-making ability was lowered and the quality in the examples was not reached.

  The results are shown in Table 1.

Next, the kind and content of polyester used in further examples and comparative examples will be described.
A: Polyethylene terephthalate (IV = 0.73)
82 parts by weight of ethylene glycol (ethylene glycol / terephthalic acid molar ratio = 2) with respect to 100 parts by weight of terephthalic acid in a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade .2) 0.05 mol% of germanium oxide as the Ge element and 0.05 mol% of magnesium acetate as the Mg element are charged with respect to the acid component, and nitrogen is introduced while stirring to bring the pressure in the system to 0.3 MPa. The esterification reaction was carried out while distilling out the water produced at a temperature of 230 ° C. to 250 ° C. outside the system. After completion of the reaction, 0.04 mol% of trimethyl phosphate as P amount was added at 250 ° C., the pressure was gradually reduced while the temperature was raised, and a polycondensation reaction was performed under a vacuum of 275 ° C. and 1.0 hPa or less. The obtained intrinsic viscosity 0.73 polyester (PET) resin was used.
B: Polyethylene terephthalate / isophthalate (10 mol% of ethylene isophthalate repeating unit, IV = 0.74, 0.5% by weight of ethylene terephthalate cyclic trimer).
90 parts by weight of terephthalic acid, 10 parts by weight of isophthalic acid, 82 parts by weight of ethylene glycol (ethylene glycol / total acid component) were added to a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade. Molar ratio = 2.2), 0.05 mol% of germanium oxide as the Ge element and 0.05 mol% of the magnesium acetate as the Mg element are charged with respect to the acid component, and nitrogen is introduced with stirring to introduce pressure in the system. Was maintained at 0.3 MPa, and the esterification reaction was carried out while distilling off the water produced at a temperature of 230 ° C. to 250 ° C. out of the system. After completion of the reaction, at 250 ° C., 0.04 mol% of trimethyl phosphate is added as the P amount, the pressure is gradually reduced while the temperature is raised, and a polycondensation reaction is performed under a vacuum of 275 ° C. and 1.0 hPa or less. Obtained. Subsequently, this polyester was heat-treated at 200 ° C. under a vacuum of 1.0 hPa for 12 hours to obtain PET-I (10). The polyester obtained had an intrinsic viscosity of 0.74 (dl / g) and an ethylene terephthalate cyclic trimer of 0.5% by weight.
C: Polytetramethylene terephthalate-polytetramethylene oxide block copolymer polyester In a reactor equipped with an inlet, a thermometer, a pressure gauge, a distillation tube with a rectifying column, and a stirring blade, with respect to 100 parts by weight of dimethyl terephthalate , 75 parts by weight of 1,4-butanediol, 75 parts by weight of polytetramethylene glycol (average molecular weight 1000), and 0.05 parts by weight of normal butyl titanate were distilled out of the system at 190 ° C. to 230 ° C. The transesterification reaction was carried out. After completion of the reaction, 0.05 part by weight of tetranormal butyl titanate and 0.025 part by weight of phosphoric acid were added, and a polycondensation reaction was performed at 250 ° C. under reduced pressure (1.0 hPa or less). Polytetramethylene terephthalate-polytetramethylene oxide block copolymer, polytetramethylene oxide ratio 40% by weight, intrinsic viscosity 0.75). (Brand GP301 manufactured by Toyobo)
D: Polyester containing 5% by weight of antioxidant 5 parts by weight of phenolic antioxidant (Irganox 1010, manufactured by Ciba Geigy) is melt-kneaded with 95 parts by weight of polyester A, and oxidized. A polyester resin (D) containing 5% by weight of an inhibitor was obtained.
E: Lubricant masterbatch (1)
With respect to 90 parts by weight of polyester A, 10 parts by weight of SiO _{2 having} an average particle diameter of 5 μm was melt-kneaded with a twin-screw extruder to obtain a polyester resin (E) containing 10% by weight of SiO ₂ .
F: Lubricant masterbatch (2)
90 parts by weight of polyester A and 10 parts by weight of crosslinked PMMA having an average particle diameter of 5 μm were melt-kneaded with a twin-screw extruder to obtain a polyester resin (F) containing 10% by weight of SiO ₂ .
G: Lubricant masterbatch (3)
With respect to 90 parts by weight of polyester A, 10 parts by weight of SiO _{2 having} an average particle size of 3 μm was melt-kneaded with a twin screw extruder to obtain a polyester resin (G) containing 10% by weight of SiO ₂ .
H: Lubricant master batch (4)
With respect to 90 parts by weight of polyester A, 10 parts by weight of SiO _{2 having} an average particle diameter of 2 μm was melt-kneaded by a twin screw extruder to obtain a polyester resin (G) containing 10% by weight of SiO ₂ .

(Example 6)
[Preparation of polyester film]
After drying polyester A / B / C / D / E = 67/15/4/4/10 (% by weight) as a raw material at 100 ° C. for 24 hours and melting at 270 ° C. using a single screw extruder, An unstretched sheet was obtained by extruding onto a cooling roll in layers from a T die. The unstretched sheet was stretched 3.3 times in the machine direction at a preheating temperature of 80 ° C. and a stretching temperature of 100 ° C., and further stretched by 3.7 times in the transverse direction at a preheating temperature of 80 ° C. and a stretching temperature of 100 ° C. A polyester film having a thickness of 10 μm was obtained by heat treatment at 8 ° C. for 8 seconds.

[Production of film-laminated metal sheet]
Passing between the nip rolls and laminating so that the polyester film and the metal plate produced above are in contact with both surfaces of the preheated aluminum plate, heat treatment is performed, and immediately cooled immediately in a 10-40 ° C. water bath, A metal plate having a film laminated on both sides was obtained. At the time of laminating, there was no initial adhesion, tension fluctuation, winding around a nip roll, etc., and the laminating suitability of the laminated film of this example was good.
Next, the film-laminated metal plate was subjected to 90 Sec heat treatment at 270 ° C. and then air-cooled and further quenched in water to prepare a remelt metal plate. In remelting, there was no reduction in molecular weight, and a remelting plate having a good dynamic friction coefficient using a steel ball as a slider under an environment of 150 ° C. was obtained.

[Production of film-laminated metal container]
The remelt metal plate produced above was drawn and ironed so that the thickness reduction rate was 30% to form a film laminated metal container. The obtained can product had no film molecular weight reduction, a good dynamic friction coefficient using a steel ball in a 150 ° C. environment as a slider, no galling or blur on the outer surface, and excellent can manufacturing performance.

(Example 7)
The subsequent film-forming / can-making process and evaluation are the same as in Example 6 except that polyester A / B / C / D / F = 67/15/4/4/10 (% by weight) as a raw material.
As in Example 1, the resulting can product had a good dynamic friction coefficient with a steel ball in a 150 ° C. environment as a slider, was free from galling or tearing on the outer surface, and was excellent in can manufacturing performance. .

(Example 8)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 6 except that polyester A / B / C / D / G = 67/15/4/4/10 (wt%) as a raw material.
As in Example 6, the produced can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, no galling or blurring, and excellent can manufacturing performance.

Example 9
The subsequent film-forming / can-making process and evaluation are the same as in Example 6 except that polyester A / B / C / D / E = 74/8/4/4/10 (% by weight) as a raw material.
As in Example 6, the produced can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, no galling or blurring, and excellent can manufacturing performance.

(Example 10)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 6 except that polyester A / B / C / D / E = 70/15/4/1/10 (% by weight) is used as a raw material.
As in Example 6, the produced can product had a good coefficient of dynamic friction using a steel ball in a 150 ° C. environment as a slider, no galling or blurring, and excellent can manufacturing performance.

(Comparative Example 5)
The subsequent film-forming / can-making process and evaluation are in accordance with Example 16 except that polyester A / B / C / D / H = 67/15/4/4/10 (wt%) as a raw material.
Although the resulting beverage can did not have a decrease in molecular weight or the like, galling frequently occurred at the time of can making, and did not reach the quality in the examples.

(Comparative Example 6)
Example 16 for the subsequent film-forming / can-making process and evaluation except that polyester A / B / C / D / E = 70.9 / 15/4 / 0.1 / 10 (% by weight) as a raw material According to
The resulting beverage can had a decrease in molecular weight, resulting in a decrease in can-making ability, and did not reach the quality in the examples.

(Comparative Example 7)
Example 6 for the film forming / can manufacturing process and evaluation thereafter, except that polyester A / B / C / D / E = 76.7 / 15/4/4 / 0.3 (% by weight) was used as a raw material. According to
The resulting beverage cans did not reach the quality in the examples due to frequent galling during canning.

  The results are shown in Tables 1 and 2.

  In the present invention, the metal plate laminating film has excellent can processability such as drawing and ironing, and is particularly suitable for coating the outer surface of a drawn iron can, so that it can be used in a wide range of applications such as beverage cans. It can greatly contribute to the industry.

Claims (9)

Thermoplastic having a melting point in the range of 240 to 252 ° C. and containing 2 to 20 mol% of an alkylene oxide unit having 2 or more carbon atoms derived from the polyoxyalkylene glycol component based on the total acid amount of the polyester resin composition A metal plate laminating film comprising a polyester resin composition,
After the film existing on the metal substrate is remelted by 270 ° C. heat (so-called remelt treatment) and rapidly cooled, a steel ball loaded with a load of 2 kg in a 150 ° C. environment is used as a slider. The dynamic friction coefficient of the film surface is 0.20 or less,
In addition, the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled, and the weight average molecular weight (A) and the film are laminated on the metal substrate. Both the weight average molecular weight (B) after the existing film is remelted by heat at 270 ° C. (so-called remelt treatment), rapidly cooled and canned, and both are 40,000 or more,
In addition, the film existing on the metal substrate is remelted with a heat of 270 ° C. (so-called remelt treatment) and rapidly cooled, and then the weight average molecular weight (A) is bonded to the metal substrate. A metal characterized in that the relationship of the weight average molecular weight (B) after remelting (so-called remelt treatment) with heat at 270 ° C., rapidly cooling, and can-making processing satisfies the following formula (1): Film for board lamination.
(B) / (A) ≦ 1 (1)   The thermoplastic polyester resin composition according to claim 1, comprising 0.01 to 1.0% by weight of an antioxidant.   The thermoplastic polyester resin composition according to claim 1, containing 0.05 to 2.0% by weight of inert particles.   The film according to claim 1 is a film sampled from a can which has been film-processed by re-melting (so-called remelt treatment) the film existing by laminating the film on a metal substrate with heat at 270 ° C. % Stretch strength is in the range of 14 N to 10 N / 15 mm. A film-laminated metal plate, wherein the film for covering a drawn iron can according to claim 4 is coated on a metal plate.   6. A squeezed iron can made from the film-laminated metal plate according to claim 5. Thermoplastic having a melting point in the range of 240 to 252 ° C. and containing 2 to 20 mol% of an alkylene oxide unit having 2 or more carbon atoms derived from the polyoxyalkylene glycol component based on the total acid amount of the polyester resin composition A metal plate laminating film comprising a polyester resin composition,
The weight average molecular weight (A) of the thermoplastic polyester resin composition is 40000 or more,
And the thermoplastic polyester resin composition contains 0.01 to 1.0% by weight of an antioxidant, and the thermoplastic polyester resin contains 0.3 to 2.0% by weight of lubricant particles having an average particle size of 3 μm or more. A film for laminating metal sheets, characterized in that: A laminated metal plate obtained by laminating a polyester film, wherein the film has a melting point in the range of 240 to 252 ° C., and an alkylene oxide unit having 2 or more carbon atoms derived from a polyoxyalkylene glycol component is a polyester resin composition. The melting point of 2 to 20 mol% based on the total acid amount is in the range of 240 to 252 ° C,
It consists of a thermoplastic polyester resin composition,
The center surface surface roughness after re-melting (so-called remelt treatment) the film existing on the metal substrate by heat at 270 ° C. and rapidly cooling is 0.2 or more,
A laminate metal having a weight average molecular weight (A) of 40,000 or more after the film existing on the metal substrate is remelted by heat at 270 ° C. (so-called remelt treatment) and rapidly cooled. Board.   A metal can obtained by making the laminated metal plate according to claim 8.