JP2010023418A - Organic resin laminated steel plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin laminated steel plate exhibiting sufficient corrosion resistance and adhesiveness even when using a non-plated steel plate. <P>SOLUTION: The organic resin laminated steel plate coated with one or more layers of polyester resin films is the non-plated steel plate. The surface of the steel plate includes a root mean square roughness Rq of 0.01-2.5 μm and a maximum trough depth Rv of 0.03-15.0 μm. The polyester resin film layer abutting on the steel plate contains 10-100 mol% of cyclohexanedimethanol unit out of the whole alcohol unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic resin laminated steel sheet in which one or more resin films are coated on a non-plated steel sheet.

  Organic resin laminated steel sheet is a steel sheet with an organic resin film laminated (coated) on the surface of the steel sheet. The film can improve corrosion resistance, workability, design, etc., and cans, cans, electronic materials It is used for materials and building materials.

  The manufacturing method of the organic resin laminated steel sheet is a heat laminating method in which a pre-formed organic resin film is pressure-bonded to and bonded to a steel sheet heated to a temperature higher than the melting point of the film, and a thermoplastic resin film melted in the steel sheet is caused to flow down from a T-die. It is manufactured by an extrusion laminating method for laminating or a method of laminating a resin film with an adhesive.

  Resin films used in laminated steel sheets are polyesters for odor, hygiene, and processability for food cans, and polyolefins and electronic materials in terms of chemical resistance for chemical cans. For heat-resistant polyimide and building material applications, various resin films are used depending on the application, such as appearance and contamination resistance, and fluorine-based materials. Moreover, tin-free steel, tin-plated steel sheet, galvanized steel sheet, etc. are used as the steel sheet according to required characteristics such as corrosion resistance, workability and weldability.

  In Patent Document 1, as a laminated steel sheet application excellent in squeezing and squeezing ability, a resin film composed of a crystalline polyester resin and an amorphous polyester resin can be mentioned. From the viewpoint of corrosion resistance and adhesion, a steel sheet subjected to tin plating and chromate treatment. Is used.

  Patent Document 2 discloses an alloy resin laminate film using an ionomer resin as a resin film having improved impact resistance. However, as a metal plate, a tin-plated steel sheet, tin plate, which also has excellent corrosion resistance adhesion, is disclosed. Free steel or aluminum plate is used.

  In Patent Document 3, as a resin film excellent in adhesion and impact resistance, an epoxy-containing resin is further added to a resin composition of a polyester resin and an epoxy-containing resin containing an epoxy group, so that the polyester resin contains the polyester resin. A metal coating resin film in which an epoxy resin is finely dispersed is disclosed. As a steel plate, a tin-plated steel plate, tin-free steel, or the like is used.

  Furthermore, in Patent Document 4, as a container film having moldability, adhesion, impact resistance, and corrosion resistance after filling and retort sterilization, the laminate upper layer is a biaxially stretched polyester resin film, and the lower layer is PET-G. A two-layer film made of an amorphous polymer resin film such as an aluminum plate, a mild steel plate, tin-free steel, etc. is disclosed as a metal plate, and in terms of adhesion and corrosion resistance after processing, especially tin-free steel It is being considered. Furthermore, Patent Document 5 describes that the corrosion resistance of the film is improved by dispersing particles of tin or tin salt in the film.

  Further, in Patent Document 6, even when the temperature of the steel sheet at the time of bonding is 220 ° C., the foam does not foam and the adhesiveness is good, the durability in boiling water is good, and the adhesiveness with the caulking agent is good. For the purpose of providing a decorative film for steel sheet, a part of ethylene glycol, which is a diol part of polyethylene terephthalate, was replaced with 33 mol% of 1,4-cyclohexanedimethanol on the bonding surface side with the steel sheet. An adhesive layer (A layer) having a thickness of 6 μm as a main component of the copolymerized polyethylene terephthalate resin is provided, and a layer (B layer) mainly composed of polybutylene terephthalate blended with a pigment is formed on the adhesive layer. A three-layer surface layer (C layer) that does not contain a pigment made of polybutylene terephthalate and polyethylene terephthalate resin is provided on the upper part of the B layer. Coated steel sheet consisting viewed 125μm is disclosed, as a steel sheet, it has been described that the cold-rolled steel sheets of plain steel having a thickness of 0.10~0.50mm are preferred.

Japanese Patent Laid-Open No. 3-269074 JP-A-7-195617 JP 2003-113292 A JP 2003-225967 A Japanese Patent Application Laid-Open No. 8-252884 JP 2006-181753 A

  Resin films for laminated steel sheets are required to have extremely diverse characteristics such as corrosion resistance, adhesion, impact resistance, workability, weather resistance, aroma retention, and beauty. Among these, corrosion resistance and adhesion can be improved by surface treatment of steel materials such as plating of tin or zinc, or chromate. In other words, by using surface-treated steel, it is possible to reduce the required properties of the film, and accordingly, it is possible to develop a film that specializes in other properties, increasing the degree of freedom in resin design. To do. On the other hand, various plated steel sheets and surface-treated steel sheets with chromate treatment, etc. are metal materials used for surface treatment such as plating, process costs compared to non-plated steel sheets that have not been plated. Because it contains, it must be expensive. Therefore, if a non-plated steel sheet can be used as the surface-treated steel sheet, it is possible to reduce the cost of the laminated steel sheet. To that end, it is necessary to supplement the adhesion and corrosion resistance characteristics imparted by plating by some method. .

  In fact, when a film disclosed for a plated steel sheet is conventionally laminated on a non-plated steel sheet and subjected to a retort treatment generally performed on container materials, a large amount of minute rust (hereinafter referred to as pitting) is generated. It became clear. Since these lead to deterioration of various properties such as peeling of the film, deterioration of appearance, and deterioration of fragrance retention, it is essential to prevent the occurrence of pitting.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a resin-laminated steel sheet that exhibits sufficient corrosion resistance and adhesion even when a non-plated steel sheet is used.

  The present inventors diligently studied to solve the above-mentioned problems, obtained the following knowledge, and completed the present invention. Specifically, a resin focusing on the crystallinity of polyester as seen in Patent Document 1, a resin aimed at improving impact resistance as seen in Patent Documents 2 and 3, There is a possibility that any resin that controls the brittleness of the resin film by controlling the crystallinity and improves the corrosion resistance after retort cannot be used for non-plated steel sheets due to insufficient corrosion resistance. is there. Further, as seen in Patent Document 5, an organic resin film in which particles of tin or tin salt are dispersed for the purpose of imparting anticorrosive properties to the film is difficult to disperse metal in the resin, There is a possibility of adverse effects such as wear on the resin kneading apparatus and elution of tin salt into the contents. Further, the invention disclosed in Patent Document 6 has no mention regarding the occurrence of rust and the roughness of the steel sheet, and the corrosion resistance evaluation is boiling water different from the evaluation of the present invention. There is a problem with the corrosion resistance which the present invention has a problem.

  Then, when the generation | occurrence | production of the rust in the non-plated steel plate laminated with the resin film was examined in detail, it became clear that the pitting was generated in the fine void at the interface between the steel plate and the resin film. That is, water and oxygen that have permeated through the resin film accumulate in fine voids at the interface between the steel sheet and the resin film, causing corrosion and pitting. Therefore, in order to improve this pitting, it is necessary to reduce fine voids at the interface between the steel plate and the resin film. For this purpose, by improving the resin, make the resin easy to flow into the fine irregularities on the surface of the non-plated steel sheet (improving the “thickness of the resin”), and smooth the irregularities of the non-plated steel sheet. Therefore, it is important to relatively improve the throwing power of the resin.

  Here, in order to improve the throwing power of the resin, it is necessary to reduce the interaction between the molecular chains of the resin. If the resin-resin interaction is lowered, the resin-steel surface interaction is relatively increased, and the steel plate surface is covered with the resin. One technique for reducing the interaction between resin molecular chains is to coexist molecules of different shapes. For example, cyclohexanedimethanol (hereinafter referred to as CHDM) is an alicyclic compound that forms a stable six-membered ring, and is a rigid molecule with a low degree of freedom due to the problem of steric hindrance of protons at the 1-3 position. This has completely different characteristics from ethylene glycol used for polyethylene terephthalate, butylene glycol used for polybutylene terephthalate, etc., which are linear compounds rich in flexibility. That is, by making these coexist, the resin-resin interaction is lowered due to the low interaction of molecules having different characteristics, the resin-steel surface interaction is relatively increased, and the throwing power is improved. Fine gaps between the film and the steel plate are reduced, and as a result, generation of rust can be suppressed.

  Moreover, as a steel plate, it is also important to improve the throwing power of the resin relatively by controlling the roughness of the steel plate within a certain low range. These have been found and the present invention has been completed. Furthermore, by adding a polyolefin-based resin and an epoxy-containing resin to the polyester resin, the throwing power of the resin can be further improved. These have been found and the present invention has been completed.

That is, the gist of the present invention is as follows.
(1) An organic resin laminated steel sheet in which one or both surfaces of a steel sheet are coated with one or more polyester resin (A) films, wherein the steel sheet is a non-plated steel sheet, and the surface of the steel sheet has a root mean square The roughness Rq is 0.01 to 2.5 μm, the maximum valley depth Rv is 0.03 to 15.0 μm, and the layer of the polyester resin (A) film in contact with the steel plate is composed of all alcohol units. An organic resin laminated steel sheet containing 10 to 100 mol% of cyclohexanedimethanol unit.
(2) The organic resin according to (1), wherein the ratio of the total thickness of the polyester resin (A) film to the thickness of the steel plate (steel plate thickness / film thickness) is 3 to 35. Laminated steel sheet.
(3) having one or more resin film layers made of a resin selected from polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate on the film layer of the polyester resin (A) in contact with the steel plate; The total thickness of the film layers is 200 μm or less, and the thickness ratio between the film in contact with the steel plate and the other film (the film thickness not in contact with the steel plate / the film thickness in contact with the steel plate) is 0.5 to 16 The organic resin-laminated steel sheet according to (1) or (2), wherein
(4) The polyester resin (A) film in contact with the steel sheet further contains a plastomer (B, hereinafter simply referred to as polyolefin resin) made of a polyolefin resin, and an epoxy-containing resin (C), and the polyolefin The mass ratio (B) :( C) of the epoxy resin (B) and the epoxy resin (C) is 1.0: 10 to 15: 1.0, and the polyolefin resin (B) and the epoxy resin The mass% of the total amount of the resin (C) to the total resin ((A) + (B) + (C)) is 1 to 30%, and the polyester resin (A) is encapsulated with the epoxy-containing resin (C). The organic resin-laminated steel sheet according to any one of (1) to (3), wherein the converted polyolefin resin fat (B) is dispersed.

  In the present invention, the non-plated steel sheet means zinc plating, zinc-aluminum alloy plating, zinc-cobalt-molybdenum plating, tin plating, nickel plating, chromium plating, nickel-phosphorous plating, nickel-zinc plating nickel-cobalt plating. , A steel plate not subjected to any treatment of nickel-tin plating or aluminum plating.

  In the present invention, the alcohol unit refers to a constituent element when alcohol becomes a polyester molecule, for example, an oxyethyleneoxy group when ethylene glycol becomes polyester. The carboxylic acid unit refers to a constituent element when the carboxylic acid becomes a polyester molecule, for example, a carbonylphenylenecarbonyl group when terephthalic acid becomes a polyester.

  According to the resin film of the present invention, it is possible to suppress the occurrence of rust such as pitting, even when using a non-plated steel sheet with low rust prevention performance as a metal plate. Various necessary characteristics, that is, adhesion to metal and impact resistance can be excellent.

  As a result, the polyester has inherent properties such as aroma retention, taste retention, moldability, heat resistance, chemical resistance, mechanical strength, gas barrier properties, appearance beauty, and manufacturability, that is, non-plating. It can be suitably used as a resin film for steel plate coating.

  The present invention will be described below.

(1) Polyester raw material The polyester resin (A) used in the present invention is a thermoplastic polyester comprising a dicarboxylic acid compound and a diol compound or a hydroxycarboxylic acid compound unit, a dicarboxylic acid unit and a diol compound unit as constituent units. Or the mixture of the said thermoplastic polyester may be sufficient.

  Examples of the hydroxycarboxylic acid compound that is a raw material of the hydroxycarboxylic acid compound unit include p-hydroxybenzoic acid, p-hydroxyethylbenzoic acid, 2- (4-hydroxyphenyl) -2- (4′-carboxyphenyl) propane, and the like. These may be used alone or in combination of two or more.

  Examples of the dicarboxylic acid compound forming the dicarboxylic acid unit include terephthalic acid, isophthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2, Aromatic dicarboxylic acids such as 7-naphthalenedicarboxylic acid, diphenic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, and adipic acid, pimelic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, malonic acid, succinic acid, malic acid And aliphatic dicarboxylic acids such as citric acid and cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid. These may be used alone or in admixture of two or more.

  Next, as will be described later, it is important that the resin of the present invention contains a predetermined amount of cyclohexanedimethanol unit. Examples of diol compounds forming other diol units include 2,2- Bis (4-hydroxyphenyl) propane (hereinafter abbreviated as “bisphenol A”), bis (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, o-hydroxyphenyl-p-hydroxyphenylmethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) ) -P-diisopropylbenzene, bis ( , 5-dimethyl-4-hydroxyphenyl) methane, bis (3-methyl-4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3,5-dimethyl-4-) Hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) Ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -1- Phenylethane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl) buta 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo -4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3- Bromo-4-hydroxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxyphenyl) propane, 4,4′-biphenol, 3,3 ′, 5 , 5′-tetramethyl-4,4′-dihydroxybiphenyl, 4,4′-dihydroxybenzophenone and other aromatic diols, and ethylene glycol, trimethylene glycol, Fatty oils such as propylene glycol, tetramethylene glycol, 1,4-butanediol, pentamethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, hydrogenated bisphenol A And alicyclic diols such as cyclohexane dimethanol, and the like can be used alone or in combination of two or more.

  The polyester resin obtained from these may be used alone or in combination of two or more as long as it contains a predetermined amount of CHDM units as described in the next section. An aromatic polyester resin composed of an acid unit and a diol unit is preferred from the viewpoints of processability and thermal stability.

  The polyester resin (A) used in the present invention is a small amount of structural units derived from polyfunctional compounds such as trimesic acid, pyromellitic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, pentaerythritol, for example, An amount of 2 mol% or less may be included.

  Examples of the preferred polyester resin (A) used in the present invention include polyethylene terephthalate containing a predetermined amount of cyclohexanedimethanol unit, polybutylene terephthalate containing a predetermined amount of cyclohexanedimethanol unit, and cyclohexanedimethanol unit. Examples include polyhexamethylene terephthalate, polycyclohexylene dimethylene terephthalate, and polyethylene-2,6-naphthalate, polybutylene-2,6-naphthalate containing a predetermined amount of cyclohexanedimethanol unit. Polyethylene terephthalate and cyclohexane dimethanol containing a certain amount of cyclohexane dimethanol units with moderate mechanical properties, gas barrier properties, and metal adhesion Polybutylene terephthalate containing a predetermined amount of knit, polyethylene-2,6-naphthalate containing a predetermined amount of cyclohexanedimethanol unit, and polybutylene-2,6-naphthalate containing a predetermined amount of cyclohexanedimethanol unit Most preferred.

  The polyester resin (A) film layer (underlayer) in contact with the steel plate must contain a predetermined amount of CHDM units as shown below, but the effect of the present invention can be achieved with only the underlayer. The composition of the polyester resin film of one or more layers provided on the foundation layer is not particularly limited as long as it is made of the polyester raw materials listed above.

<Cyclohexanedimethanol (CHDM) unit>
In the polyester resin (A) of the present invention, the layer of the polyester resin film in contact with the steel plate has a resin-resin interaction from the viewpoint that the resin flows into the irregularities on the steel plate surface during lamination and eliminates fine voids at the steel plate / film interface. It is necessary to contain a CHDM unit as a diol component that lowers the pH. The polyester resin film layer in contact with the steel sheet contains 10 to 100 mol% of CHDM units with respect to all alcohol units. When the CHDM unit content is less than 10 mol%, the resin-resin interaction increases, the throwing power of the resin decreases, fine voids are generated between the resin film and the steel plate, and pitting occurs. It becomes easy. Further, from the viewpoint of reducing the generation of fine voids, the CHDM unit content is preferably 20 mol% or more, and from the viewpoint of further reducing the fine voids, the CHDM unit content is 28 mol% or more. It is preferable that Further, from the viewpoint of preventing the resin rigidity from being lowered excessively, the content of the CHDM unit is more preferably 90% or less, and from the viewpoint of improving impact resistance, the content of the CHDM unit is 60%. The following is preferred.

  The content of the CHDM unit can be determined by nuclear magnetic resonance analysis after dissolving the resin with 1,1,1,3,3,3-hexafluoro-1-propanol or the like.

  Further, as a method of adding the CHDM unit, as long as the total content of the CHDM unit is within the above range, a polyester not containing the CHDM unit and a polyester containing the CHDM unit may be mixed, or the CHDM unit is contained. Polyester may be used alone.

(2) Physical property of polyester resin (A) It is preferable that the intrinsic viscosity of the polyester resin (A) containing the CHDM unit used for this invention is 0.5-1.25 dl / g. When the intrinsic viscosity is less than 0.5 dl / g, when the resin of the present invention is produced by kneading, the melt viscosity of the resin is too low, and the film forming property may be lowered. On the other hand, if the intrinsic viscosity exceeds 1.25 dl / g, a high temperature is required to obtain an appropriate resin melt viscosity at the time of film formation, and the resin is likely to be thermally deteriorated, which is not preferable. From the viewpoint of impact resistance, the intrinsic viscosity is preferably 0.65 dl / g or more. Furthermore, since a resin having a high intrinsic viscosity is produced by solid phase synthesis and is relatively expensive, the intrinsic viscosity is preferably 0.8 dl / g or less from the viewpoint of cost.

The intrinsic viscosity is measured at a concentration of 0.5% in o-chlorophenol at 25 ° C., and is obtained by the following equation (i). In the formula, C represents the concentration expressed in grams of resin per 100 ml of solution, t ₀ represents the solvent flow time, and t represents the solution flow time.
Intrinsic viscosity = {ln (t / t ₀ )} / C (i)

  The polyester resin (A) used in the present invention has a glass transition temperature (Tg, sample amount of about 10 mg, can be measured with a differential thermal analyzer (DSC) at a heating rate of 10 ° C./min), usually 30 to 120 ° C. More preferably, it is desirable that it is 65-100 degreeC. This is because if the glass transition temperature Tg is lower than 30 ° C., the polyester resin is soft and processability tends to deteriorate, whereas if it exceeds 120 ° C., the resin is hard and impact resistance tends to be lowered.

(3) Alloying The resin of the present invention comprises a polyester resin (A), a polyolefin resin (B), and an epoxy-containing resin (C) as main components, and the polyolefin resin (B) is an epoxy-containing resin (C). It is preferable to use a polymer alloy encapsulated by Such a polymer alloy is preferable from the viewpoint of adding further improvement in throwing power and impact resistance to the anti-pitting ability of the polyester resin (A) of the present invention.

  The mass ratio of the polyolefin resin (B) and the epoxy-containing resin (C) is preferably in the range of (B) :( C) = 1.0: 10 to 15: 1.0. If the ratio of the polyolefin resin (B) is less than the mass ratio (B) :( C) = 1.0: 10, the impact resistance improvement by the polyolefin resin may be incomplete. On the other hand, when the ratio of the polyolefin resin (B) is larger than the mass ratio (B) :( C) = 15: 1.0, the encapsulated structure may be incomplete. More preferably, the mass ratio (B) :( C) is in the range of 1.0: 8 to 10: 1.0.

  Mass% (100 × ((B) + (C)) / ((A) of polyolefin resin (B) and epoxy-containing resin (C) with respect to total resin ((A) + (B) + (C))) ) + (B) + (C))) is preferably 1 to 30% by mass. If it is less than 1% by mass, neck-in (neck in, the width of the extrudate from the T dice becomes narrower than the width of the dice due to shrinkage in the width direction of the dice when the width of the extrudate from the dice comes out of the dice) increases, and the effective film area increases. Problems such as narrowing and non-uniform film thickness may occur. On the other hand, if it exceeds 30% by mass, the resin of the present invention becomes excessively flexible due to the low elastic modulus of the polyolefin resin fat (B) and the epoxy-containing resin (C), and the material strength may decrease. . Furthermore, from the viewpoint of the small neck-in and the appropriate hardness of the resin, the mass% is preferably 2 to 30 mass%, more preferably 3 to 25 mass%.

(4) Polyolefin resin (B)
As the polyolefin resin (B) used when the resin film of the present invention is a polymer alloy, plastomers and linear low density polyethylene (LLDPE) made of a known polyolefin resin can be widely used.

(5) Epoxy-containing resin (C)
The epoxy-containing resin (C) used when the resin composition of the present invention is a polymer alloy is a vinyl compound containing an epoxy group, such as glycidyl acrylate or glycidyl methacrylate, and a nonpolar vinyl represented by the following general formula (ii) Examples thereof include a copolymer with a monomer.
CHR ¹ = CR ² R ³ (ii)
(In the formula, R ¹ and R ³ each independently represent an alkyl group having 1 to 12 carbon atoms or hydrogen, and R ² represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, or hydrogen.)

  The content of the vinyl compound containing an epoxy group is preferably 1 to 20 mol% when the total resin is 100 mol%. If it is less than 1 mol%, the following encapsulation will be insufficient, and if it exceeds 20 mol%, the heat resistance may be lowered.

  Specific examples of the nonpolar vinyl monomer represented by the general formula (ii) include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1 Α-olefins such as dodecene, aliphatic vinyl monomers such as isobutene and isobutylene, styrene monomers, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p -Alkyl styrene such as ethyl styrene and t-butyl styrene, and aromatic vinyl monomers such as addition polymer units of styrene monomers such as α-methyl styrene.

  Furthermore, said epoxy-containing resin (C) may also contain the unit derived from a polar vinyl compound. Examples of polar vinyl compounds include vinyl alcohol, methyl acrylate, methyl methacrylate, vinyl acetate and the like. The content of the polar vinyl compound is preferably 1 to 40 mol% when the epoxy-containing resin is 100 mol%. If it is less than 1 mol%, the following encapsulation will be insufficient, and if it exceeds 40 mol%, the elastic modulus of the resin will decrease and the material strength may decrease.

  When the preferable epoxy-containing resin (C) used by this invention is illustrated, an ethylene-glycidyl methacrylate copolymer and an ethylene-glycidyl methacrylate-vinyl acetate copolymer will be mentioned in terms of high encapsulation ability.

(6) Physical properties of epoxy-containing resin (C) The molecular weight of the epoxy-containing resin (C) is not particularly limited, but is preferably 2 × 10 ³ or more and 5 × 10 ⁵ or less in terms of number average molecular weight. If it is less than 2 × 10 ³ or more than 5 × 10 ⁵ , the impact resistance may be lowered. The molecular weight can be determined as long as it is an ordinary method for measuring the molecular weight of a polymer, and can be measured by, for example, gel permeation chromatography (GPC).

(7) Higher-order structure of ternary resin film: finely dispersed encapsulated structure When the resin film of the present invention is a polymer alloy, polyester resin (A), polyolefin resin (B), epoxy-containing resin (C) The polyolefin resin (B) is finely dispersed in the polyester resin (A), and the polyolefin resin (B) is encapsulated with the epoxy resin-containing epoxy resin (C). Since the metal plate is coated with the resin as a film, the impact resistance and the adhesion to the metal plate are further improved.

  By having such an encapsulated finely-dispersed higher-order structure, a biaxially stretched film formed with a bilayer structure of a crystalline layer and a polycrystalline layer as in the past is laminated with strict temperature control. Unlike troublesome and expensive processes, even unstretched films can achieve high impact resistance and high adhesion to metals that do not require strict temperature control.

  Thus, by realizing high impact resistance and high adhesion, it is possible to improve the quality and reduce the film thickness, and to reduce the cost and tougher cans (lightweight cans) than before. Moreover, since a drawing process is unnecessary, the film forming process by direct lamination to a metal plate can be omitted, and even higher impact resistance can be realized by drawing. In addition, since strict temperature control is unnecessary, it is possible to reduce the cost by thinning and high-speed manufacturing, or to improve the quality by stabilizing the film thickness and performance, or both the cost reduction and the quality improvement. It becomes possible.

(8) Ternary high-order structure: definition of dispersion In the present invention, “dispersion” of the polyolefin resin (B) in the polyester resin (A) means that 70% of all the particles of the polyolefin resin (B). Polyester resin (A) with an average diameter (number average diameter) of projected area circle equivalent diameters of 100% or less (the diameter of a circle having the same area as the projected area of the particles, which can be measured by a microscopic method) of particles of volume% or more It is in a dispersed state. If the average diameter of the projected area equivalent circle diameter of the encapsulated polyolefin resin (B) is more than 100 μm, the impact resistance may be lowered, and the film-forming property of the resin film of the present invention may be lowered. The average diameter of the projected area equivalent circle diameter is preferably 1 μm or less, more preferably 9.5 μm or less. If it exceeds 1 μm, sufficient impact resistance may not be exhibited.

(9) Ternary higher order structure: definition of encapsulation Further, the polyolefin resin (B) “encapsulated” with the epoxy-containing resin (C) is 80% or more of the interface of the polyolefin resin (B), preferably Is a structure in which 95% or more is covered with an epoxy-containing resin (C) and the direct contact area between the polyester resin (A) and the polyolefin resin (B) is less than 20%. By adopting such a structure, the fine dispersion of the polyolefin resin (B) encapsulated with the epoxy-containing resin (C) is facilitated, and the impact resistance and film forming property are improved. The polyolefin resin (B) generally has low adhesion to the metal plate, but since the epoxy-containing resin (C) having a polar group has adhesion to the metal plate, the finely dispersed particles are in contact with the metal plate. However, it has the effect of ensuring sufficient adhesion between the resin film and the metal plate.

  It is not necessary that all the particles of the polyolefin resin (B) are encapsulated with the epoxy resin (C), but at least 70% or more of the polyolefin resin (B) is encapsulated with the epoxy resin (C) by volume. It just needs to be. When the non-encapsulated polyolefin resin (B) exceeds 30% by volume, fine dispersion becomes difficult, impact resistance is low, and when the resin film is coated on the metal plate, the metal plate The ratio of the polyolefin resin (B) in direct contact with the resin may increase, and it may be impossible to ensure the adhesion between the resin film and the metal plate.

  The average diameter of the projected area equivalent circle diameter of the non-encapsulated polyolefin resin (B) is not particularly specified, but is preferably 1.0 μm or less from the viewpoint of impact resistance and workability.

  Further, an excessive amount of the epoxy-containing resin (C) may be dispersed alone in the polyester resin (A) without encapsulating the polyolefin resin (B). The amount and diameter of the epoxy-containing resin (C) that is not encapsulated is not particularly limited, but is 20% or less by volume ratio of the total epoxy-containing resin (C), and the average diameter of the projected area circle equivalent diameter is 1.0 μm. The following is desirable. If the volume ratio exceeds 20%, the basic properties such as heat resistance of the resin film may change. In addition, when the average diameter of the projected area equivalent circle diameter exceeds 1.0 μm, the workability may deteriorate.

  Whether the polyolefin resin (B) has a structure encapsulated with the epoxy-containing resin (C) can be confirmed as follows. That is, after cutting an ultrathin section from a resin composition with a microtome, the capsule structure can be observed by staining with ruthenic acid and observing with a transmission electron microscope.

(10) Principle of encapsulation by mixing The ternary resin composition as described above is mixed and the polyolefin resin (B) encapsulated with the epoxy-containing resin (C) is finely dispersed in the polyester resin (A). For this, it is important to properly balance the interfacial tension between the epoxy-containing resin (C), the polyester resin (A), and the polyolefin resin (B).

Preferably, the content of the unit having a polar group is controlled so that the Spread Parameter (λ _{(Resin C) / (Resin B)} ) of the epoxy-containing resin (C) with respect to the polyolefin resin (B) is positive. . By making λ _{(Resin C) / (Resin B)} positive, thermodynamic stability can be ensured even if the polyolefin resin (B) is encapsulated with the epoxy-containing resin (C). The “Spread Parameter” between different kinds of polymers is S.A. Y. Hobbs; Polym. , Vol. 29, p1598 (1988), which is given by the following equation (iv).
λ _{(Resin C) / (Resin B)} = Υ _{(Resin C) / (Resin A)} −Υ _{(Resin C) / (Resin B)} −Υ _{(Resin B) / (Resin A)} (iv)
[In the formula, Resin A represents the polyester resin (A), Resin B represents the polyolefin resin (B), Resin C represents the epoxy-containing resin (C), and _{i / j} represents the resin i. It is the interfacial tension between the resins j, and is approximately proportional to the 0.5th power of the parameter Χ _{i / j} indicating the compatibility between the resins i and _j (the smaller the value, the better the compatibility). . ]

Since the compatibility between the polyester resin (A) and the polyolefin resin (B) is low and Υ _{(Resin B) / (Resin A)} > 0, the nonpolar vinyl monomer (Monomer V) of the epoxy-containing resin (C) C showing the compatibility between the polyolefin-based resin (B) and the epoxy-containing resin (C) given by the following formulas (v) and (vi) by adjusting the mixing ratio of the polar group-containing unit (Monomer U) _{If B / C} and c _{A / B} indicating the compatibility between the polyester resin (A) and the epoxy-containing resin (C) are brought close to 0, λ _{(Resin C) / (Resin B)} will be positive. It becomes possible to do.
_{cA / C} = [phi] c _{(Resin A) / (Monomer V)} + (1- [phi]) c _{(Resin A) / (Monomer U)} -[phi] _{(1- [} phi] c) _{(Monomer V) / (Monomer U)} (v )
_{cB / C} = [phi] c _{(Resin C) / (Monomer V)} + (1- [phi]) c _{(Resin C) / (Monomer U)} -[phi] _{(1- [} phi]) c _{(Monomer V) / (Monomer U)} (vi )
[However, φ indicates the blending ratio (volume ratio) of the nonpolar vinyl monomer. ]

  Therefore, a preferable epoxy-containing resin (C) is determined in consideration of compatibility with these resins, depending on the types of the polyester resin (A) and the polyolefin resin (B).

When a preferable combination is specifically exemplified, when the polyester resin (A) is an aromatic polyester resin composed of an aromatic dicarboxylic acid unit and a diol unit, and the polyolefin resin (B) is a polyolefin resin, an epoxy-containing resin ( C) is preferably a copolymer of ethylene and a unit having a polar group, or SEBS into which maleic anhydride or glycidyl methacrylate is introduced in an amount of 1% by mass or more. Among them, a copolymer of ethylene and a unit having a polar group is ethylene. It is easy to positively control λ _{(Resin C) / (Resin B)} by appropriately controlling the blending ratio between the units having a polar group. More preferably, when a functional group having a chemical action such as a covalent bond, a coordination bond, a hydrogen bond, and an ionic bond is introduced into the copolymer of ethylene and a unit having a polar group with the polyester resin (A), It is desirable because the interface between the polyester resin (A) and the epoxy-containing resin (C) can be thermodynamically stabilized when encapsulated.

(11) Method for Producing Encapsulated Ternary Resin Film When the film of the present invention is a polymer alloy, a resin film containing a polyester resin (A), an epoxy-containing resin (C), and a polyolefin resin (B) is used. An encapsulated structure can be produced by a known mixing method. Specifically, after selecting a polyester resin (A), an epoxy-containing resin (C) and a polyolefin resin (B) having an appropriate difference in interfacial tension, they are known at a predetermined temperature, for example, 200 to 350 ° C. When melt kneading is performed using various mixers, a capsule structure can be formed and produced using the difference in interfacial tension.

(12) Method for Producing Resin Film As a method for producing the resin film of the present invention, when a plurality of resin raw materials are used, a T-die or the like after melt-kneading with a single-screw or twin-screw extruder, kneader, Banbury mixer, etc. The method of extruding from is mentioned. When the resin mixture is composed of a plurality of resins, known resin kneading methods such as a resin kneading method and a solvent kneading method can be widely used. Moreover, even when the resin raw material consists of a single material or a plurality of resin raw materials, a method of directly extruding using a single-screw or twin-screw extruder provided with a T die can be used.

  Examples of the resin kneading method include a method of mixing by dry blending with a tumbler blender, Henschel mixer, V-type blender, etc., and then melt-kneading with a single or twin screw extruder, kneader, Banbury mixer or the like. In addition, as an example of the solvent mixing method, after each resin is dissolved in the common solvent of the raw material resin included in the resin film, the solvent is evaporated or added to the common poor solvent and the precipitated mixture is recovered. is there.

  The production temperature of the resin film of the present invention is not particularly limited as long as the film can be formed with a desired film thickness and thickness accuracy. Usually, it can be produced at 170 ° C. or more and 300 ° C. or less where the polyester is in a molten state.

(13) Reinforcing agent In addition, the resin film of the present invention has a fiber reinforcing agent such as glass fiber, metal fiber, potassium titanate, carbon fiber, talc, carbonic acid for the purpose of improving rigidity and linear expansion characteristics. Fillers such as calcium, mica, glass flake, milled fiber, metal flake, and metal powder may be mixed. Among these fillers, the glass fiber and the carbon fiber preferably have a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more. Moreover, as these addition amount, it is desirable that it is 0.5-50 mass parts with respect to the total resin composition substance amount.

(14) Additives Further, according to the purpose, the resin film has an antioxidant, a heat stabilizer, a light stabilizer, a release agent, a lubricant, a pigment, a flame retardant, a plasticizer, an antistatic agent, an antibacterial anti-antibacterial agent. It is also possible to add an appropriate amount of a mold agent or the like.

(15) Multi-layering For the purpose of improving flavor properties and impact resistance, it is used in combination with this resin film in combination with other resin films or adhesives, or both other resin films and adhesives. There is no problem.

(16) Example of metal plate when using coating The resin film of the present invention can be used as a coating material for non-plated steel sheets. As the non-plated steel sheet, the steel type is not particularly limited, but cold-rolled steel sheets used as original sheets such as hot-dip galvanized steel sheets, electrogalvanized steel sheets, nickel-plated steel sheets, and tin-plated steel sheets are listed.

  Moreover, since the resin film of this invention has high throwing power to a steel plate and high adhesiveness, it can be used for a plated steel plate. As the plated steel plate, the metal plate is not particularly limited, but cans such as tinplate, thin tin plated steel plate, electrolytic chromic acid treated steel plate (tin-free steel), nickel plated steel plate, hot dip galvanized steel plate, molten steel Galvanized steel sheets such as zinc-iron alloy-plated steel sheets, hot-dip zinc-aluminum-magnesium alloy-plated steel sheets, molten aluminum-silicon alloy-plated steel sheets, hot-dip lead-tin alloy-plated steel sheets, electrogalvanized steel sheets, and electrogalvanized nickel-plated steel sheets And surface-treated steel sheets such as electroplated steel sheets such as electrogalvanized-iron alloy plated steel sheets and electrogalvanized-chromium alloy plated steel sheets, cold-rolled steel sheets, and metal plates such as aluminum, copper, nickel, zinc, and magnesium.

  Further, the coating on the metal plate may be either single-sided or double-sided depending on the application.

(17) Surface Roughness of Steel Plate In order to improve the throwing power of the resin and prevent pitting, it is necessary to appropriately control the unevenness caused by the surface roughness of the steel plate. When the height in the depth direction of the steel plate surface roughness is large, the resin cannot completely flow when melted, and there is a possibility that fine voids are formed at the interface between the steel plate and the organic resin. Therefore, in order to control the local surface roughness of the steel sheet, the root mean square roughness Rq needs to be 0.01 to 2.5 μm in order to control the surface roughness of the entire steel sheet surface. is there. If it is less than 0.01 μm, the so-called “anchor effect” in which the resin enters the gap between the steel plates and develops the adhesive force cannot be obtained, and the adhesion may be lowered. When the thickness exceeds 2.5 μm, the resin cannot completely flow into the unevenness caused by the surface roughness of the steel sheet when melted, and a minute gap may be generated between the steel sheet and the resin. In particular, from the viewpoint of suppression of pitting on wet conditions, Rq is preferably 0.03 to 1.6 μm.

  In addition, it is not sufficient to suppress the occurrence of minute voids by simply maintaining Rq, which is an average value of unevenness due to roughness, at a constant value, and the maximum valley depth Rv of the roughness curve is also kept constant. Need to keep. This is because, if the valley depth is specifically deep, the throwing power of the resin deteriorates, and if it is shallow, a site where the anchor effect is specifically reduced may occur, which may cause peeling. is there.

  Therefore, the maximum valley depth Rv needs to be 0.03 to 15.0 μm. In particular, from the viewpoint of suppression of pitting on wet conditions, Rv is preferably 0.08 to 7.0 μm, and more preferably 0.10 to 6.0 μm.

  Thus, in order to suppress the number of pitting after retort sterilization treatment of organic resin laminated steel sheet using non-plated steel sheet, it contains CHDM having a molecular structure bent to organic resin, and steel sheet surface roughness is reduced. By controlling with the maximum valley depth Rv and the root mean square roughness Rq, it can be achieved by suppressing the generation of minute voids at the interface between the steel plate and the organic resin.

  In addition, the measuring method of Rq and Rz is described in JIS B0601.

(18) Resin film thickness In order to eliminate the fine gap between the resin and the steel sheet, it is important to improve the throwing power of the resin. It is necessary to prevent it from occurring. The generation of micro voids that are the starting point of pitting is mainly caused by the stress caused by the difference in thermal expansion coefficient between the steel and the resin when the resin is cooled. The ratio of the total thickness of the polyester resin film and the steel material thickness is preferably 35 ≧ (steel material thickness / film thickness) ≧ 3. When the thickness ratio is more than 35, the residual stress becomes strong, and there is a possibility that micro voids are generated. On the other hand, when the thickness ratio is less than 3, the film cooling rate through the steel plate is slow, crystallization is not uniform, and there is a possibility that minute voids are generated.

(19) Total thickness of resin film layer One or more resin film layers made of a resin selected from polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are formed on the polyester resin (A) film layer in contact with the steel plate. And the total thickness of the resin film layers is preferably 200 μm or less. When the total thickness of the resin film layer exceeds 200 μm, the film is easily peeled off, which is not preferable.

(20) Film thickness ratio It is preferable that the thickness ratio between the film in contact with the steel sheet and the other film (film thickness not in contact with the steel sheet / film thickness in contact with the steel sheet) is 0.5 to 16. If (thickness of film not in contact with steel plate / thickness of film in contact with steel plate) is less than 0.5, the film thickness becomes too thin for the condition that steel material thickness = weight, and the film can be easily formed when the materials collide with each other. It is not preferable because it becomes torn. On the other hand, if (film thickness not in contact with the steel sheet / film thickness in contact with the steel sheet) exceeds 16, the thickness of the film having a large linear expansion coefficient compared to the steel sheet is too thick, so that the stress generated during temperature change increases. It is not preferable because the film is easily peeled.

  As a method for measuring the film thickness in the present invention, the steel sheet is dissolved with hydrochloric acid or the like, and the film is isolated and measured with a micrometer, or the laminated steel sheet is measured with an eddy current film thickness meter, etc. The film thickness of the film can be measured.

(21) Coating method of metal plate Known methods can be used for coating the metal plate, such as film pressure bonding (indirect / direct) and direct lamination. Specifically, (1) A method in which a resin composition prepared by melting and kneading a raw material resin with a kneader in advance is molded into a resin film with an extruder with a T die and thermocompression bonded to a metal plate ( In this case, the film may be unstretched or may be stretched in one or two directions), and (2) a method of directly thermocompression bonding the film from the T die. Furthermore, as another method of directly thermocompression bonding the film, (3) the present resin composition instead of the resin composition prepared by melt kneading the raw material resin with a kneader in advance in a hopper of an extruder with a T die There is a method in which a resin that is a raw material of the product is charged, kneaded into a resin composition in an extruder, and directly thermocompression bonded, and the coating method is not particularly limited.

(22) Use of lubricant For the purpose of improving the lubricity at the time of metal plate coating and metal plate processing, a known lubricant as disclosed in JP-A-5-186613 may be added. . The lubricant may be any of inorganic systems such as silica, alumina, titania, calcium carbonate and barium sulfate, and organic systems such as crosslinked polystyrene particles and silicone particles, but inorganic systems are preferred.

  The average particle size of the lubricant is preferably 2.5 μm or less. If it exceeds 2.5 μm, the mechanical properties of the resin film deteriorate. Although the addition amount of a lubricant is determined according to the winding property and deep drawing workability of a metal plate, 0.05-20 mass% is preferable.

  In particular, a monodispersed lubricant having an average particle size (number average particle size of primary particles) of 2.5 μm or less and a particle size ratio (major axis / minor axis) of 1.0 to 1.2 is a pin-resistant material. It is suitable in terms of holes, and examples thereof include true spherical silica, true spherical titanium oxide, and true spherical silicone. The average particle size (number average particle size) and particle size ratio of the lubricant can be determined by observing the particles with an electron microscope. The particle size distribution of the lubricant is sharp and the standard deviation is preferably 0.5 or less.

  Since the addition amount of the lubricant is related to the winding property in the film production process, it is generally preferable to use a small amount when the particle size is large and a large amount when the particle size is small. For example, although it depends on the type of lubricant, the average particle size is 0.2 to 2.0 μm and is about 0.02 to 0.5 mass%.

(23) Use of pigment The resin film of the present invention may contain a pigment. For example, examples of white pigments include inorganic pigments such as alumina, titanium dioxide, calcium carbonate, and barium sulfate. The average particle diameter (number average particle diameter) of the pigment is preferably 2.5 μm or less for the same reason as the particle diameter of the lubricant. The addition amount of the pigment is an amount necessary for achieving the coloring function, and is used within a range of about 3 to 50% by mass. The addition method of a pigment can be based on a well-known method.

(24) Use of plasticizer, antistatic agent, antibacterial agent, etc. As a plasticizer for a polyester resin, for example, an aromatic having 8 to 20 carbon atoms with respect to a fatty acid polybasic acid having 2 to 20 carbon atoms or an ester-forming derivative thereof. A polycondensation product of these polybasic acid components having a polybasic acid or ester-forming derivative molar ratio of 0 to 2.0 and an aliphatic alcohol having 2 to 20 carbon atoms is used. The plasticizer for polyester resins which consists of polyester which terminal-esterified with the monobasic acid or its ester-forming derivative and / or C1-C18 monohydric alcohol can be mentioned.

  In a resin composition such as an antistatic agent disclosed in JP-A-5-222357, for the purpose of preventing electrostatic disturbances such as winding of a film around a roll in a film forming step and adhesion of dirt to the film surface. If necessary, a method of kneading into a film or a method of applying an antistatic agent described in JP-A No. 5-1164 to the film surface can be applied.

  Further, conventionally known antibacterial agents disclosed in JP-A-11-48431, JP-A-11-138702 and the like can be used as necessary.

(25) Lamination method (multilayer / single layer, single side / double side, metal thickness)
In addition, when the resin film of the present invention is coated on a metal plate, the metal plate is coated on one or both sides by laminating one layer or two or more layers in a single layer or multiple layers using at least the resin film. can do. At this time, one or two or more kinds of resin films may be laminated in a single layer or multiple layers on one or both sides of the metal plate, and if necessary, polyester such as PET film or polycarbonate film. Film, polyolefin film such as polyethylene film, polyamide film such as 6-nylon film, other known resin film such as ionomer film, crystalline / amorphous polyester composition film, polyester / ionomer composition film, A known resin composition film such as a polyester / polycarbonate composition film may be laminated and coated on the upper layer. In particular, in food applications and the like, it is preferable to laminate a conventionally used polyester film on the film of the present invention from the viewpoints of wrinkle resistance, heat resistance, and improved flavor properties. As the polyester, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and blends thereof are particularly preferable from the viewpoint of improving the scratch resistance. As a specific lamination method, when using the method described above, a multilayer film of the resin film of the present invention and another resin film or resin composition film is manufactured using a multilayer T die, and this is used. There is a method of thermocompression bonding. The resin-coated metal plate of the present invention is a metal plate coated with the resin film of the present invention, and the coating may be single-sided or double-sided. The thickness of the metal plate is not particularly limited, but is preferably 0.01 to 5 mm. If it is less than 0.01 mm, the strength may be difficult to develop. If it exceeds 5 mm, processing may be difficult.

  Next, based on an Example and a comparative example, this invention is demonstrated more concretely.

  In the following examples and comparative examples, as polyester resin (A), Mitsubishi Chemical Corporation IG189Z (abbreviated as 189), Unitika Ltd. SA1346P (abbreviated as 1346), Teijin Corporation TR3000H (3000H) (Abbreviated), Easter 6863 (abbreviated as CHDM ratio 33%, 6763), AN004 (CHDM ratio 100%), DN011 (CHDM ratio 54%), 9921 (CHDM ratio 20%), Toray (stock) ) Toraycon 1200S (abbreviated as 1200S), Teito Kasei's Teonex TN8756 (abbreviated as 8756), a plastomer (B) made of polyolefin resin, Mitsui Chemicals' plastomer 00100 (abbreviated as 00100), Dow Chemical Japan Co., Ltd. Affinity 184 1845, 1850, (abbreviated as 1840, 1845, 1850) Evolu 0540, 1540, 2540 (abbreviated as 0540, 1540, 2540, respectively) manufactured by Prime Polymer Co., Ltd., epoxy resin (C), Sumitomo Chemical Co., Ltd. ) Bond First 7L (abbreviated as 7L), 7B, 7E, 7M, 2C, 2B, and E were used. As the metal plate, a cold rolled steel plate for tin having a thickness of 0.1 to 0.7 mm was used. In addition, the confirmation of the capsule structure in the present example is based on whether a polyolefin resin (B) has a structure encapsulated with an epoxy-containing resin (C). Thereafter, the capsule structure was observed by staining with ruthenic acid or the like and observing with a transmission electron microscope.

(Examples 1 to 23)
Examples 1 to 23 (Table 1) are examples containing 10 to 100% of CHDM units. In each case, pellets mixed in the composition shown in Table 1 were used to obtain a film having a predetermined thickness as an extruded T-die (extrusion temperature: 250 to 265 ° C., lip width = 310 mm, winding speed = 5.5). 6.8 m / min, distance between lip / first roll = 10 cm). When two kinds of PET were used, they were mixed and used at a ratio shown in Table 1. The obtained film was stretched on one side of a 5 cm square non-plated steel plate heated to 250 ° C. and rapidly cooled to 100 ° C. or less within 10 seconds by water cooling to produce a resin-coated metal plate.

  Rq and Rv were measured using an Olympus scanning confocal laser microscope LS1100.

(Comparative Examples 1 to 13)
Comparative Examples 1 to 13 (Table 2) are examples in which the CHDM unit is less than 10%, or Rq, Rv, and film thickness are inappropriate. Production and analysis of the film are the same as in the examples.

  The resin-coated metal plate thus obtained was evaluated for corrosion resistance and impact resistance by the following evaluation method.

<Corrosion resistance evaluation>
The resin-coated metal plate was subjected to a hydrothermal sterilization treatment at 121 ° C. for 30 minutes in an autoclave, and then evaluated by the number of pitting around 25 cm ² . The evaluation was ◎: 0 to 5, ◯: 6 to 20, Δ: 21 to 30, and x: 31 or more. The number of samples was 3 per 1 level. In addition, when there was a thing from which evaluation differs with samples, it showed like "(double-circle)" (Examples 3-7).

<Impact resistance evaluation>
Furthermore, the impact resistance of this resin-coated metal plate was evaluated by a DuPont drop impact test. After dropping 0.5 kg of iron ball onto a metal plate from a height of 30 cm, the ERV value (mA) is measured when a voltage of +6 V is applied with the sample as the anode and the copper plate as the cathode in 1.0% saline. did. The ERV value was evaluated according to the following index. A: All samples were evaluated under the criteria of less than 0.01 mA, ○: 1-3 samples were 0.01 mA or more, Δ: 4-6 samples were 0.01 mA or more, and X: 7 samples or more were 0.01 mA or more. . The number of samples was 10 per 1 level.

  Tables 3 and 4 show the results of corrosion resistance evaluation (number of pitting) and impact resistance evaluation.

  From the results of Table 3, it can be seen that all of the resin compositions of the present invention have good corrosion resistance, have little pitting corrosion, and have high impact resistance even after being subjected to hydrothermal sterilization treatment. . Moreover, it turns out that it is especially excellent in corrosion resistance and workability as a steel plate / film thickness ratio is 3-35. On the other hand, it can be seen from the results in Table 4 that the corrosion resistance is poor when at least one of the content of the CHDM unit, Rq, and Rv is outside the scope of the present invention.

(Examples 26 to 43)
Examples 26 to 43 are examples of polymer alloys containing 25 to 33% of CHDM units in polyester (A), and further containing a plastomer (B) made of a polyolefin resin and a polar interaction resin (C). In each case, pellets mixed in the composition shown in Table 5 were used to obtain a film having a predetermined thickness as an extruded T die (extrusion temperature: 250 to 265 ° C., lip width = 310 mm, winding speed = 5.5). 6.8 m / min, distance between lip / first roll = 10 cm). The obtained film was stretched on one side of a 5 cm square non-plated steel plate heated to 250 ° C. and rapidly cooled to 100 ° C. or less within 10 seconds by water cooling to produce a resin-coated metal plate.

  The resin-coated metal plate thus obtained was evaluated for corrosion resistance and impact resistance by the same evaluation method as in Examples 1 to 25 above. Table 6 shows the results of the corrosion resistance evaluation (number of pitting) and the impact resistance evaluation.

  From the results of Table 6, the resin composition of the present invention was extremely good in corrosion resistance and hydrothermally sterilized in the case of a polymer alloy containing the polar interaction resin (B) and the polar interaction resin (C). Later, it can be seen that there is no occurrence of pitting, the corrosion resistance is high, and the impact resistance is particularly high.

(Examples 44 to 46)
Examples 44 to 46 are examples including a plurality of resin layers. In each case, the resin of Table 7 was extruded as a film to obtain a film having a thickness of 25 μm by a T-die (extrusion temperature: 250 to 265 ° C. (275 to 285 ° C. in the case of 8756), lip width = 310 mm, winding speed = 5 0.5-6.8 m / min, distance between lip / first roll = 10 cm). After the obtained films were stacked so as to have the structure shown in Table 7, they were stretched on one side of a 5 cm square non-plated steel sheet heated to 250 ° C., and rapidly cooled to 100 ° C. or less within 10 seconds by water cooling. A coated metal plate was produced. In Table 7, “lower layer” represents a resin film layer in direct contact with the metal plate, and “upper layer” represents a layer not in direct contact.

(Comparative Example 14)
In Comparative Example 14, a resin-coated metal plate was produced in the same manner as in Examples 28-30. However, the lower layer was a resin containing 5 mol% of CHDM units by using a mixture of PET1 and PET2.

  These resin-coated steel sheets were subjected to the same corrosion resistance evaluation and impact resistance evaluation as in Examples 1 to 28, and further to the heat resistance evaluation as described below.

<Heat resistance evaluation>
A weight (20 g in weight, 10 mm in diameter) was placed with the resin film side of the resin-coated metal plate facing up, and held at 70 ° C. for 10 minutes. Visually, the thing without a push ridge was set as (circle), and a certain thing was set as x. Tables 9 and 10 show the results of corrosion resistance evaluation (number of pitting), impact resistance evaluation, and heat resistance evaluation.

  From the results of Tables 9 and 10, it can be seen that although Comparative Example 14 still has low corrosion resistance, the two-layered resin composition of the present invention has high scratch resistance (heat resistance).

(Example 47)
In Example 47, a polymer alloy containing 33 mol% of CHDM units in polyester (A) and further containing a plastomer (B) and an epoxy-containing resin (C) made of a polyolefin resin is a lower layer, and a polyester is further formed thereon. It is an example which has a layer. Using the pellets mixed in the composition shown in Table 11, a film having a thickness of 25 μm was obtained by extrusion T-die as a film (extrusion temperature: 250-265 ° C., lip width = 310 mm, winding speed = 5.5-6. 8 m / min, distance between lip / first roll = 10 cm). After the obtained films were stacked so as to have the structure shown in Table 12, the film was heated to 250 ° C., stretched on one side of a 5 cm square non-plated steel sheet, rapidly cooled to 100 ° C. or less within 10 seconds by water cooling, A coated metal plate was produced.

  By the above production, an encapsulated polyolefin resin (B) in which 95% of the interface of the polyolefin resin (B) was covered with the epoxy-containing resin (C) was obtained. Further, 70% by volume or more of all particles of the polyolefin resin (B) were dispersed in the polyester resin (A) with an average diameter (number average diameter) of a projected area equivalent circle diameter of 1 μm or less.

  The same corrosion resistance evaluation, impact resistance evaluation and heat resistance evaluation as in Examples 42 to 44 were performed on this resin-coated steel sheet. Table 12 shows the results of corrosion resistance evaluation (number of pitting), impact resistance evaluation, and heat resistance evaluation.

  From Table 12, the resin composition of the present invention containing a plastomer (B) made of polyolefin resin and an epoxy-containing resin (C) has very good impact resistance and high scratch resistance (heat resistance). I understand that.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

Claims (4)

An organic resin laminated steel sheet in which one or both surfaces of a steel sheet are coated with one or more layers of a polyester resin (A) film,
The steel plate is a non-plated steel plate,
The surface of the steel sheet has a root mean square roughness Rq of 0.01 to 2.5 μm and a maximum valley depth Rv of 0.03 to 15.0 μm.
The layer of the polyester resin (A) film in contact with the steel plate contains 10 to 100 mol% of cyclohexanedimethanol units among all alcohol units.   2. The organic resin laminated steel sheet according to claim 1, wherein a ratio of the total thickness of the polyester resin (A) film and the thickness of the steel sheet (steel sheet thickness / film thickness) is 3 to 35. 3. On the layer of the polyester resin (A) film in contact with the steel sheet, it has one or more resin film layers made of a resin selected from polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate,
The total thickness of the resin film layers is 200 μm or less, and the thickness ratio between the film in contact with the steel sheet and the other film (film thickness not in contact with the steel sheet / film thickness in contact with the steel sheet) is 0.5. The organic resin laminated steel sheet according to claim 1, wherein the organic resin laminated steel sheet is ˜16. The polyester resin (A) film in contact with the steel sheet further contains a plastomer made of a polyolefin resin (B, hereinafter simply referred to as a polyolefin resin), and an epoxy-containing resin (C),
The mass ratio (B) :( C) of the polyolefin resin (B) and the epoxy-containing resin (C) is 1.0: 10 to 15: 1.0,
The mass% with respect to the total resin ((A) + (B) + (C)) of the total amount of the polyolefin resin (B) and the epoxy-containing resin (C) is 1 to 30%,
The organic resin according to any one of claims 1 to 3, wherein a polyolefin resin fat (B) encapsulated with an epoxy-containing resin (C) is dispersed in the polyester resin (A). Resin laminated steel sheet.