WO2003068498A1

WO2003068498A1 - Resin-coated metal plate and method for production thereof

Info

Publication number: WO2003068498A1
Application number: PCT/JP2003/001278
Authority: WO
Inventors: Toshiaki Ebitani; Yoshio Wakayama; Yasuhiro Takaki
Original assignee: Mitsubishi Plastics, Inc.
Priority date: 2002-02-15
Filing date: 2003-02-06
Publication date: 2003-08-21
Also published as: KR100969445B1; CN1551826A; CN100382954C; JP4194950B2; TW200303261A; TWI305515B; KR20040081192A; JPWO2003068498A1

Abstract

A resin-coated metal plate (11) having a metal plate (12) and, laminated in the following order on one side thereof via an adhesive layer (13), a base resin layer (14) containing a polyester based resin as a primary component, a printed layer (15), and a transparent stretched polyester layer (16), characterized in that a polyester based resin constituting the base resin layer (14) satisfies the requirement that, in the state of an integrated sheet (S) before its lamination on the metal plate (12), a crystallization peak temperature (Tc) and a crystal melting peak temperature (Tm) are clearly observed in the temperature rise step of the measurement with a differential scanning calorimeter (DSC), and the amount of heat of crystallization (ΔHc, J/g) and the amount of heat of crystal melting (ΔHm, J/g) satisfy the relationship: (ΔHm - ΔHc) < 30.

Description

Specification

TECHNICAL FIELD The present invention relates to a resin-coated metal plate and a method of manufacturing the same.

The present invention relates to AV equipment, air conditioners birch Chief household appliances exterior and steel furniture, elevator interior, resin-coated metal sheet and a manufacturing method thereof, for use in building interiors and the like _(details scratch filled resistance, The present invention relates to a resin-coated metal plate having excellent workability, excellent specular reflectivity, excellent heat boiling water resistance, and not using a halogen-containing resin, and a method for producing the same.

Conventionally, as a resin-coated metal plate used for the above applications, a resin layer colored by adding a pigment is used as a base resin layer, a printing layer is provided thereon, and a transparent resin film is further laminated and integrated on it. A sheet having a configuration in which a laminated sheet is laminated on a steel plate has been used.

As the transparent resin film in the above configuration, for example, an ethylene-vinyl alcohol copolymer film, an acrylate copolymer film, a biaxially stretched polyethylene terephthalate (hereinafter, referred to as 2) having a thickness of 10 to 50 / zm. It is common to use an axially stretched PET film). Among them, biaxially stretched PET resin films having excellent various physical properties are preferably used.

As the colored resin layer, a soft vinyl chloride resin layer was generally used. This is because the flexibility of the soft vinyl chloride resin can be arbitrarily set by adding a plasticizer. In addition, even in a configuration in which a transparent biaxially stretched PET resin film is laminated, in addition to obtaining good workability, it has relatively good durability based on many years of research on stabilizers, and has chemical resistance. It also has excellent heat resistance and hot water resistance, so it is preferably used for applications such as bath units. Further, in a configuration in which a biaxially stretched PET resin film is laminated on a soft vinyl chloride resin, extremely good specular reflectivity can be obtained. That is, one of the features is that the image reflected on the resin-coated metal plate has little distortion and high clarity.

However, in recent years, there have been problems with heavy metal compounds caused by stabilizers in vinyl chloride resins, problems with VOCs (volatile organic compounds) and endocrine disrupting effects caused by some plasticizers and stabilizers, and chlorides during combustion. Due to problems such as generation of hydrogen gas and other chlorine-containing gases, vinyl chloride resin Its use has come to be restricted.

Therefore, instead of the soft vinyl chloride resin that is the colored resin layer having the above-described configuration, a polyolefin resin such as polypropylene is mainly used, and a soft component such as styrene or copolymerized olefin is blended. The use of a resin having properties close to those of a soft pinyl chloride resin was carried out. Even in this configuration, with the configuration in which the biaxially stretched PET resin film was laminated, it was possible to obtain the same excellent specular reflectivity as when the soft vinyl chloride resin was used for the colored resin layer. .

However, if sufficient workability is imparted as a precoated steel sheet, the surface will be inferior to scratch resistance as compared with batab using a soft vinyl chloride resin. In addition, if the scratch resistance is made equal to that of the soft pinyl chloride-based resin-coated metal plate, there is a problem that satisfactory heat resistance cannot be obtained, and it cannot be used widely.

On the other hand, since polyolefin resin is inherently poor in adhesiveness, when a printing design is applied and laminated with a biaxially stretched PET resin, the number of processes (for example, A surface treatment step such as corona treatment or primer coating). In addition, uncertainties remain regarding the temporal stability of the bonding interface and the interface with the adhesive used for bonding to the metal plate.

Therefore, as a material for solving these problems, the use of a polyester-based resin as the colored resin layer having the above configuration has been studied. A metal plate coated with this resin can achieve both scratch resistance and workability at a higher level than a soft vinyl chloride resin-coated metal plate, and can solve various problems with a polyolefin resin-coated metal plate. You can do it. Problems to be solved by the invention

However, when a non-crystalline calenderable polyester resin is used as the colored resin layer, the glass transition temperature (T g) is lower than 100 τ: However, the boiling water immersion test generally included in the evaluation items of resin-coated metal plates for building interior cannot be satisfied. On the other hand, when a crystalline polyester resin such as polyethylene terephthalate or polyethylene terephthalate is used as the colored resin layer, its melting point is high, so that a conventional vinyl chloride resin film or polyolefin resin film is used. It is necessary to raise the temperature of the metal plate surface as compared with the case of laminating. Therefore, it is necessary to modify the existing laminating line. In addition, the back surface of the resin-coated metal plate may be subjected to a coating process, but this coating also has a problem in heat resistance in the conventional case. In this case, change the paint to one with high heat resistance, or apply the paint after laminating, instead of heating the steel sheet before lamination and drying the paint applied on the back side at the same time. Modifications must be made to perform drying and heating. Furthermore, the heat resistance of the printed layer in the laminated and integrated sheet was not a problem at the conventional laminating temperature, but when the laminating temperature was increased, thermal discoloration, thermal discoloration, etc. could appear remarkably. In that case, it is necessary to improve the heat resistance of the printing layer by changing the pigments and binder type of the printing ink. However, improvement of these problems is not welcomed because it leads to an increase in the burden on the steel sheet laminating company and, consequently, the cost.

The present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to provide an excellent mirror-reflecting property without using a soft vinyl chloride resin, and to provide a conventional laminating equipment. It is an object of the present invention to provide a resin-coated metal plate that can be manufactured by utilizing. A second purpose is to provide a resin-coated metal sheet having excellent workability and boiling water resistance in addition to excellent mirror reflectivity. A third object is to provide a manufacturing method thereof. Means for solving the problem

In order to achieve the first object, the invention according to claim 1, wherein a base resin layer mainly composed of a polyester resin, a printing layer, and a transparent stretched polyester resin layer are laminated and integrated in this order. In a resin-coated metal plate having a configuration in which a sheet is laminated on a metal plate via an adhesive layer with the surface on the base resin layer side as an adhesion surface, the polyester resin constituting the base resin layer is: Meet the following requirements: In other words, in the state of the laminated sheet before being laminated on the metal plate, a distinct crystallization peak temperature (T c), a crystal melting peak temperature (Tm), and a clear crystallization peak temperature (T c) at the time of the temperature rise in the measurement by the differential scanning calorimeter (DSC). When the heat of crystallization is ΔH e (J / g) and the heat of crystal fusion is ΔΗιη (J Zg), (ΔΗπι—AH c) and 30 are satisfied.

Here, “having a polyester-based resin as a main component” means that a resin in which an appropriate amount of an additive is added to a polyester-based resin is also included. As the additive, for example, those generally used for a wide range of resin materials are used.

In the present invention, by setting the value of (AHm−AH c) to be less than 30, the crystallinity of the base resin layer is restricted, and the crystal melting peak temperature (Tm) is shown. Therefore, it becomes fusible. Therefore, even if the lamination is performed at the surface temperature of the metal plate less than the above T m +30, the surface of the base resin layer and the surface of the metal plate are simultaneously melted and pressed by the laminating roll. The unevenness resulting from the unevenness of the surface is eliminated, and high specular reflectivity can be obtained. Conventionally, high specularity can be obtained at the temperature at the time of laminating a soft vinyl chloride resin film, and the film can be manufactured by effectively utilizing existing equipment. Further, printing inks, and also diverted those using chloride pinyl resin regard adhesive, to achieve the product cost of the _c second object can be reduced, in the invention according to claim 2, claim In the invention described in 1, the base resin layer contains a polybutylene terephthalate-based resin as a crystalline polyester resin component, and in a state after being laminated on a metal plate, the heat of crystallization ΔΗ c and the heat of fusion of crystal ΔΗηι satisfy at least one of the following relations: 15 <Δππι and 5 (AHm−ΔHc). According to the present invention, in addition to excellent specular reflectivity, workability and boiling water resistance are also improved.

In the invention according to claim 3, in the invention according to claim 1, the base resin layer contains a poly (trimethylene terephthalate) resin as a crystalline polyester resin component, and is laminated on a metal plate. In this state, the heat of crystallization AHc and the heat of crystal fusion Hm satisfy at least one of the following relational expressions: 15 <ΔΗιη and 5 <(ΔHm−ΔHc). According to the present invention, in addition to excellent specular reflectivity, workability and boiling water resistance are also improved. In the invention according to claim 4, the invention according to any one of claims 1 to 3 is provided. The transparent stretched polyester resin layer is formed of a biaxially stretched polyethylene terephthalate resin film. According to the present invention, it is easy to ensure transparency, smoothness, and scratch resistance of the surface. Further, it becomes easy to form a printing layer by performing so-called pack printing.

In the invention according to claim 5, in the invention according to any one of claims 1 to 4, an adhesive layer exists between the base resin layer and the printing layer. According to the present invention, the adhesion between the base resin layer and the printing layer is improved.

In the invention according to claim 6, in the invention according to any one of claims 1 to 5, the base resin layer is made of a colored polyester resin. According to the present invention, it is possible to shield the base metal plate, impart design, improve the coloring property of the printed layer, and the like.

The invention according to claim 7 is the method for producing a resin-coated metal plate according to any one of claims 1 to 6, wherein a base resin layer mainly composed of a polyester-based resin, Layer and a transparent stretched polyester resin layer in this order. The surface temperature T s (V) of the metal plate when laminating to the metal plate via the adhesive layer with the side surface as the bonding surface, and the crystal melting of the polyester resin constituting the base resin layer Lamination was performed in a state where the relationship of (Tm + 30)> Ts was established with the peak temperature Tm (° C).

Ό.

According to the present invention, the resin-coated metal plate can be easily manufactured by using the conventional laminating equipment, and the heat discoloration and the thermal discoloration of the printing layer and the back surface coating of the metal plate can be suppressed. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a schematic diagram showing a basic configuration of a resin-coated metal plate of the present invention, and FIG. 1B is a schematic diagram showing a modified example. Explanation of reference numerals

11 is a resin-coated metal plate, 12 is a metal plate, 13 and 17 are adhesive layers, 14 is a base resin layer, 15 is a printing layer, 16 is a transparent stretched polyester resin layer, and S is This is a laminated integrated sheet as a laminated sheet. Embodiments of the Invention

Hereinafter, embodiments of the present invention will be described.

As shown in FIG. 1 (a), the resin-coated metal plate 11 has a base resin layer 14 mainly composed of a polyester resin laminated on one side of a metal plate 12 via an adhesive layer 13. A printing layer 15 is laminated on the base resin layer 14, and a transparent stretched polyester resin layer 16 is laminated thereon. That is, the resin-coated metal plate 11 is a laminated sheet formed by laminating and integrating a base resin layer 14 mainly composed of a polyester resin, a printing layer 15, and a transparent stretched polyester resin layer 16 in this order. The laminated integrated sheet S is laminated on the metal plate 12 via the adhesive layer 13 with the surface on the side of the base resin layer 14 as an adhesive surface. In addition, in the resin-coated metal plate 11 shown in FIG. 1 (b), an adhesive layer 17 is provided between the base resin layer 14 and the printing layer 15 in addition to the configuration of FIG. 1 (a). Have been.

Examples of the polyester resin constituting the base resin layer 14 include copolymers containing alcohol components such as ethylene glycol, propylene glycol, butanediol, and cyclohexanedimethanol, and dicarboxylic acid components containing terephthalic acid and disophthalic acid. From within A single resin or a blend of arbitrarily selected resins can be used. However, in the state of the laminated sheet before being laminated on the metal plate 12, when the temperature is increased in the measurement by the differential scanning calorimeter (DSC), the crystallization peak temperature (T c) and the crystal melting peak temperature (T m) is observed, and when the heat of crystallization is ΔH e (J / g) and the heat of crystal fusion is Δ ΗΙΉ (J / g), the following equation holds.

Um Hm— um H c ku 3 0… (1)

When the value of (ΔHm-ΔHc) exceeds 30, it means that the polyester resin has high crystallinity. Therefore, unless the surface temperature of the metal plate 12 at the time of laminating is generally higher than the melting point Tm of the base resin layer 14 by about 30 ^ or more, the melting of the base resin layer 14 is sufficient. As a result, irregularities derived from the surface of the base resin layer 14 do not disappear, and irregularities derived from the surface of the metal plate 12 remain, so that high specularity cannot be obtained. The crystal melting peak temperature of the base resin layer 14 corresponds to the melting point. The reason why the surface temperature of the metal plate 12 needs to be 30 ° C. or more higher than the melting point Tm of the base resin layer 14 is to prevent the following phenomenon. Heat transfer occurs from the heated metal plate 12 to the laminated integrated sheet at the moment of lamination, instantaneously lowering the average temperature of the resin-coated metal plate 11 as a whole, and melting of the crystal of the base resin layer 14 The laminating roll takes heat when pressed by the laminating roll having a relatively low temperature relative to the metal plate 12.

However, in this case, generally, the surface temperature of the metal plate 12 at the time of lamination needs to be considerably higher than the case where a conventional soft vinyl chloride resin is used as the base resin layer 14. Issues to be Solved "will become apparent.

However, by setting the value of (AHm−AH c) to less than 30, the crystallinity of the base resin layer 14 is limited and the crystal melting peak temperature (Tm) is shown. It becomes fusible. Therefore, even if the metal plate 12 is laminated at a surface temperature of less than the above Tm + 30, it becomes molten and is pressed by the laminating roll at the same time, so that irregularities due to the above various causes are eliminated and a high mirror surface is obtained. Reflectivity is obtained.

Further, when the base resin layer 14 contains a polybutylene terephthalate (PBT) resin or a polytrimethylene terephthalate (PTT) resin as a crystalline polyester resin component and satisfies the following requirements, The resin-coated metal plate 11 excellent in boiling water can be obtained. In the state after lamination on the metal plate 12, the crystal melting peak temperature (Tm) is observed at the time of the temperature rise in the measurement by DSC, and the heat of crystallization ΔH e and the heat of crystal melting ΔHm are expressed by the following equations. At least one of (2) and (3) is satisfied. 1 5 Δ ΔHm ~ (2)

5 (Δ H m-Δ H c)-(3)

When these values are less than the specified values, the base resin layer # 4 has low crystallinity and the boiling water resistance is low as in the case where a completely amorphous polyester resin is used for the base resin layer 14. It will not be able to withstand the test, and its use as interior building materials will be limited.

If at least one of the equations (2) and (3) is satisfied, the resin-coated metal plate 11 excellent in boiling water resistance can be obtained for the following reason. When ΔΗιη of the base resin layer 14 defined by the formula (2) is larger than 15, the crystallization rate of the 樹脂 -based resin or the 樹脂 -based resin used as the crystalline resin component is relatively high. This indicates that the ratio is high and that the ratio of the crystalline resin component in the blend composition of the base resin layer 14 is high. Therefore, even if it is almost non-crystalline after lamination, crystallization occurs immediately upon immersion in boiling water, and as a result, crystallinity that can withstand the boiling water test is obtained.

On the other hand, when the expression (2) is not satisfied, it indicates that the ratio of the crystalline resin component in the blend composition of the base resin layer 14 is low. Therefore, the crystallization speed of the blend system becomes slow, and if the crystallization has not progressed beyond a certain level after lamination, it cannot withstand the boiling water test.

In order to obtain the resin composition of the base resin layer 14 satisfying the above formulas (1) and (2) or the formulas (1) and (3), a so-called homopolymer using a single component for each of the acid component and the alcohol component is used. Polybutylene terephthalate (Ρ Β Τ) resin or homopolytrimethylene terephthalate (Ρ ΤΤ) resin is used as the crystalline resin component. It is preferable to blend a non-crystalline or low-crystalline copolyester-based resin with this in view of easy adjustment of desired physical properties.

As the non-crystalline resin, Easter Man Chemical Co., Ltd., which is cost-effective because of its stable supply of raw materials and large production volume, and similar resins can be used. preferable. However, the present invention is not limited to this, and although it shows a melting point under special cooling conditions, it can generally be treated as a non-crystalline resin, such as Yeastman Chemical's "PGTG-5445". May be used.

Even when a resin with a high crystallization rate, such as Homo PBT or Homo PTT, is used as the crystalline resin, the crystallization rate of the entire blend system is determined by blending a resin with low crystallinity or a non-crystalline resin. By lowering the value, it is possible to obtain a laminated integrated sheet S satisfying the expression (1). When these crystalline resins are used, resin coating with good workability It is also preferable in that a metal plate is easily obtained.

A pigment is added to the base resin layer 14 for the purpose of shielding the metal plate 12 as a base, imparting a design property, improving the coloring property of the printed layer 15 and the like. The pigment to be used may be a pigment generally used for coloring a resin, and the addition amount may be an amount generally added for the above purpose.

An appropriate amount of an additive may be added to the base resin layer 14 and the transparent stretched polyester resin layer 16 to such an extent that the object of the present invention is not impaired. Examples of additives include various antioxidants such as phosphorus and phenol, heat stabilizers, ultraviolet absorbers, lubricants, metal deactivators, residual polymerization catalyst deactivators, nucleating agents, antibacterial agents and antibacterial agents. Examples include those generally used for a wide range of resin materials such as mold agents, antistatic agents, flame retardants, and fillers. In addition, additives developed for specific resins, such as a terminal carboxylic acid sealing agent, a hydrolyzate-based hydrolytic inhibitor, a transesterification inhibitor, and the like can be given.

An adhesive layer 17 may be present between the base resin layer 14 and the printing layer 15 or between the printing layer 15 and the transparent stretched polyester resin layer 16. The adhesive constituting the adhesive layer 17 is, for example, a polyester-based resin or a polyether-based resin as a main component, which is cured with an isocyanate-based cross-linking agent or the like. What is called can be used. Among these adhesives, it is preferable to use an aliphatic adhesive from the viewpoint of less yellowing due to ultraviolet rays.

Also, when it is necessary to control the amount of ultraviolet light transmitted to the base resin layer 14, such as when a pigment having poor light stability is added to the base resin layer 14, the adhesive layer 17 is also used. Additives such as ultraviolet absorbers may be appropriately added to the extent that the properties are not impaired.

The printing layer 15 is applied by gravure printing, offset printing, screen printing, or other known printing. The pattern of the printed layer 15 is stone-tone, wood-grain, geometric pattern, abstract pattern, etc., and may be partial printing or full-color printing. After partial printing, further printing is performed. May be. Generally, a method in which a so-called back print is applied to the lamination surface side of the transparent stretched polyester resin layer 16 having good smoothness is used, but surface printing on the base resin layer 14 may be used.

The transparent stretched polyester-based resin layer 16 used in the present invention has the same purpose as a soft vinyl chloride-based resin-coated metal plate and a olefin-based resin-coated metal plate, that is, protection of the printed layer and deep design. The same materials that have been used for the purpose of imparting and improving various physical properties of the surface can be used. Above all, a biaxially stretched polyethylene terephthalate-based resin film is preferably used in terms of transparency, smoothness, surface scratch resistance and the like. In this embodiment, the transparent stretched polyester resin layer 16 is formed of a transparent biaxially stretched polyester resin film (a transparent biaxially stretched PET resin film). The film has a thickness of about 15 tm to 75 and a heat setting temperature after elongation of about 220 T: up to about 240. can do.

Various types of steel sheets, such as hot-rolled steel sheets, cold-rolled steel sheets, hot-dip zinc-plated steel sheets, electro-zinc-plated steel sheets, tin-plated steel sheets, and stainless steel sheets, and aluminum sheets can be used as the metal sheets covered by the present invention. May be used after applying. The thickness of the metal plate 12 depends on the use of the resin-coated metal plate 11, but can be selected in the range of 0.1 mm to 10 mm. The manufacturing method of 11 will be described. As a film forming method of the laminated integrated sheet S of the present invention, a known method, for example, an extrusion casting method using a T-die, a fusion method, or the like can be adopted, and is not particularly limited. The extrusion casting method using a T die is preferred from the viewpoints of sheet film forming properties and stable productivity.

The thickness of the laminated integrated sheet S is usually 50 to 500. When the thickness of the sheet is less than 50 m, when used for a resin-coated metal plate, the performance as a protective layer for the metal plate 12 is inferior. Furthermore, since the underlying metal plate shielding ability is low, the printed pattern is affected by the color of the underlying metal plate, which is not preferable. On the other hand, if the thickness exceeds 500; tim, the suitability for secondary processing such as punching as the resin-coated metal plate 11 tends to be poor.

Further, as a method of controlling the crystallinity of the base resin layer 14 of the present invention, there is also a method of controlling a casting temperature at the time of extrusion casting.

The lamination of the base resin layer 14 and the transparent stretched polyester resin layer 16 provided with the printing layer 15 by so-called back printing is performed by pack-printed transparent stretched polyester among the sheets manufactured in advance. An adhesive layer 17 may be provided on the back-printed surface of the system resin layer 16 and laminated. The adhesive layer 17 is prepared by diluting the above-mentioned adhesive in a solvent, applying the solution by a coating device, continuously introducing the solvent into a drying oven to volatilize the solvent, and then using the other sheet ( The film is superimposed on the film and passed between a pair of rolls, so that the laminate is integrated by heating and pressing. This method has been generally used as a method for producing a highly specular resin-coated metal plate using a vinyl chloride resin or a polyolefin resin. The resin-coated metal plate 11 of the present invention is obtained by laminating the laminated integrated sheet S laminated and integrated by the above method on the metal plate 12. Examples of the adhesive for the adhesive layer 13 used for lamination include an epoxy-based adhesive, a urethane-based adhesive, and a polyester-based adhesive.

Using commonly used coating equipment such as reverse roll coater and kissing mouth and ruby for metal plate 12 and 2 The adhesive is applied so that the film thickness becomes about 2 to 10 tm. Next, the coating surface is dried and heated using at least one of an infrared heater and a hot-air heating furnace, and while the surface temperature of the metal plate 12 is maintained at a predetermined temperature, lamination is immediately performed using a roll laminator. A resin-coated metal plate 11 is obtained by coating and cooling the integrated sheet S.

Assuming that the crystal melting peak temperature of the base resin layer 14 is Tm (° C), the surface temperature Ts (° C) of the metal plate 12 during lamination is (Tm + 30) CC) or less. High specular appearance can be obtained. However, a high specular appearance cannot be obtained unless the surface temperature T s () of the metal plate 12 is at least about (Tm−10) (V).

This is because although the base resin layer 14 has the characteristic of being fusible below the crystal melting peak temperature Tm, sufficient smoothing hardening cannot be obtained if the temperature difference from the melting point is significantly low. According to. Therefore, when homo-PBT is used as the crystalline resin component of the base resin layer 14, since the crystal melting peak temperature Tm of the resin is around 25, the surface temperature of the metal plate during lamination is Is greater than or equal to 2 15 and less than or equal to 2 5 5.

The resin-coated metal plate 11 laminated by the laminating roll is continuously introduced into a cooling step. The cooling process may be a long distance and may be natural air cooling or forced air cooling. However, considering the production rate, a water cooling method is generally used. In this case, the blend composition using a PBT resin or a PTT resin, which has a faster crystallization rate, than forming the base resin layer 14 with a blend composition using a PET resin having a slow crystallization rate. It is preferable to form the base resin layer 14 by using the following formula, because the above formulas (2) and (3) can be satisfied under more rapid cooling conditions.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Production of laminated film]

Resin composition shown in Table 1 (Blending ratio (% by weight)) Using a twin-screw extruder, a thickness of 80 im Was formed into a colored polyester resin sheet (base resin layer 14). The amount of the pigment added was 24 parts by weight in total for titanium white and titanium yellow (the total amount of the resin components was 100), and was the same in all Examples and Comparative Examples. Next, a 25 m thick transparent biaxially stretched PET resin film (manufactured by Mitsubishi Chemical Polyester Co., Ltd.) as a transparent stretched polyester resin layer 16 was partially printed with an abstract pattern by gravure coating on one side to form a printing layer. 15 formed. Then, a thermosetting polyester-based adhesive is applied to the printed surface to form an adhesive layer 17, which is superimposed on the base resin layer 14 and integrated by passing between a pair of rolls. The laminated integrated sheet S was used. The type of the transparent biaxially stretched PET resin film, the type of the printing ink and the thermosetting polyester-based adhesive, the application conditions, and the like are the same in all Examples and Comparative Examples.

The base resin layer 14 was cut out from the laminated integrated sheet S by a microtome and subjected to DSC measurement to determine (AHm-AHc) before being laminated. Table 2 shows the measurement results. Similarly, the melting points described in Table 2 are the values measured at this time.

Specifically, the following were used as the resin compositions described in Table 1.

• PBT: Novaduran 502 S (Mitsubishi Engineering Plastics)

• PTT: Cortera CP50920000 (manufactured by Shell)

• c o — P E T: BK—2 180 (manufactured by Mitsubishi Chemical Polyester) Copolymer P E T in which 7% of the acid component is isophthalic acid

• PETG: Easter 6 7 6 3 (Eastman Chemical Co., Ltd.) Amorphous polyethylene in which part (about 30 to 60 mol%) of polyethylene terephthalate ethylene dalicol is replaced by 1,4-cyclohexandimethanol (Non-crystalline) polyester resin

• PCTG-. PCTG 5 4 4 5 (manufactured by Yeastman Chemical)

[Production of resin-coated metal plate]

Next, apply a polyester-based adhesive, which is commonly used for polyvinyl chloride-based resin-coated metal sheets, to the metal surface so that the adhesive film thickness after drying is about 2 to 4 / m. The agent layer 13 is formed. Next, the coated surface is dried and heated by a hot air heating furnace and an infrared heater, and the surface temperature T s (V) of the zinc plated steel sheet (0.45 mm thick) is set to each temperature shown in Table 1. Immediately, the laminated integrated sheet S was coated using a roll laminator, and cooled by water spray cooling or natural air cooling to produce a resin-coated metal plate 11. The type of adhesive and the application conditions are the same in all Examples and Comparative Examples. Table 1 shows the metal plate surface temperature and the cooling method during lamination. Also, the resin-coated metal plate 11 was immersed in dilute hydrochloric acid to separate the metal plate 12 and the laminated integrated sheet S, and then the base resin layer 14 was cut out with a microtome and subjected to DSC measurement. ΔHm and (AHm-AHc) after lamination were determined. The results are summarized in Table 2.

The following items were evaluated for each resin-coated metal plate 11. Table 3 shows the results. The measurement standards and test methods for the physical properties of the resin-coated metal plates shown in Examples and Comparative Examples are as follows.

[Crystal melting peak temperature Tm and crystal melting heat ΔHm]

Using a Perkin-Elmer DSC-7, 10 mg of the sample was heated at a heating rate of 10 / min according to JIS K 7 121, “Method for Measuring the Transition Temperature of Plastics—Determining the Melting Temperature”. Measured and determined. The crystal melting peak top temperature at the time of primary temperature rise was defined as Tm. The heat of crystal melting ΔHm was determined from the peak area.

[Crystallization peak temperature T c and heat of crystallization △ H c]

Using a Perkin-Elmer DSC-7, 10 mg of the sample was heated at a rate of 10 / min in accordance with JIS K 7 121, “Plastic dislocation temperature measurement method-Determination of crystallization temperature”. Measured and determined. The crystallization peak top temperature at the time of the first heating was Tc. The heat of crystallization ΔHc was determined from the peak area.

[Clarity gloss value (Gd value)]

Specular reflection of each resin-coated metal plate in Examples and Comparative Examples using the portable clarity gloss meter P GD IV developed by the Japan Color Research Institute, using the measurement method prescribed by the same corporation. Was measured and used as a criterion for determining high specularity. The measurement was performed at five points in the same sample, and the average value was defined as the sharpness gloss value (Gd value). 0 ((1) when the value is 0.9 or more is indicated as (を), when it is 0.8 or more and less than 0.9 is indicated as (△), and when it is less than 0.8 is indicated as (X).

[Boiling resistance test]

A 6 mm overhang of a 60 mm x 60 mm resin-coated metal plate is provided using an Ericssen tester specified in JIS-K7112 so that the resin-coated side is convex, and then boiled. The resin sheet was immersed in water for 3 hours, and the surface condition of the resin sheet was visually determined. Those that did not change at all were marked as (〇), those with a slightly roughened surface (△), and those with significant deformation such as swelling of the resin layer were marked as (X).

[Workability]

A resin-coated metal plate is subjected to an impact adhesion bending test, and the decorative sheet (laminated —The surface condition of ト s) was visually determined, and those with little change were indicated as (〇), those with some cracks were indicated as (△), and those with cracks were indicated as (X). The impact adhesion bending test was performed as follows. Resin-coated metal plate length and width directions respectively

A sample of 50 nm x 150 mm was prepared, kept at 23 for at least 1 hour, and then bent to 180 ° (inner bending radius: 2 mm) using a bending tester. A 5 mm, 5 kg mass of cylindrical weight was dropped from a height of 50 cm.

■ Umami yarn composition ratio Resin composition Rochigo combination ratio After laminating

1 (wt%) 2 (wt%) (° C) Cooling method

1 PBT 30 PETG 70 245

2 PBT 40 PETG 60 225 Water cooled

3 PBT 40 PETG 60 245 Water cooling

Real 4 PBT 40 PETG 60 245 Air cooling

Application 5 PBT 50 PETG 50 245 Water cooling

Example 6 PBT 60 PETG 40 245 Water cooling

7 PBT 40 PETG 60 245 Water cooling

8 PTT 40 PETG 60 245 Water cooling

9 PTT 50 PETG 50 245 Water cooled

1 PBT 0 PETG 100 245 Water cooled

2 PBT 10 PETG 90 245 Water cooled

3 PBT 20 PETG 80 245 Water cooled

4 PBT 30 PETG 70 245 Water cooled

Ratio

5 PBT 40 PETG 60 260 Water cooling

Early father

Example 6 PBT 70 PETG 30 245 Water cooling

7 PBT 100 PETG 0 245 Water cooled

8 co-PET 30 PETG 70 245 Water cooling

9 co-PET 50 PETG 50 245 Water cooling

10 co-PET 50 PETG 50 245 Air cooling

Two

*: Print layer As is evident from Table 3, the resin-coated metal plates 11 of Examples 1 to 9 within the scope of the present invention showed good evaluation results in all three items of high specularity, boiling water resistance and workability. Was done. On the other hand, Comparative Example 1 using only non-crystalline polyester as the resin component of the base resin layer 14 and Comparative Example 2 having a high proportion of non-crystalline polyester as the resin component of the base resin layer 14 and comparison As compared with Example 3, good evaluation results were obtained for high specularity and workability, but the boiling water resistance was poor.

Comparative Example 4 was the same as Example 1 except for the cooling conditions after lamination, except that both AH m after lamination and (AH m−AH c) were the same as those of the present invention. The requirements were not met, and good evaluation results were obtained for high specularity and heat resistance, but the boiling water resistance was poor.

In Comparative Example 5, the base resin layer 14 having the same composition as that of Examples 2 to 4 was used and laminated at a temperature higher than the laminating temperature of the conventional soft pinyl chloride resin sheet. Was good, but the thermal discoloration of the printing ink (especially reddish) was remarkable, and the rear surface coating of the metal plate 12 also caused thermal discoloration.

Comparative Example 7 using only crystalline polyester homo-PBT as the resin component of the base resin layer 14 showed that the value of (AH m−AH c) before lamination was larger than the requirement of the present invention, At a temperature close to the lamination temperature of the vinyl-based resin sheet and lower than the melting point (T m) of the resin + 30 ° C, it was not possible to obtain high specularity.

Comparative Example 6 used the same crystalline resin as Comparative Example 7 as the resin component of the base resin layer 14 and had a blend composition with the non-crystalline polyester, but the (ΔΗιτι- ΔH c) was larger than the requirement of the present invention, and high specularity could not be obtained.

Comparative Examples 8 and 9 are cases where the resin component of the base resin layer 14 is not homo- or homo-, but is copolymerized, and the lamination temperature is lower than the melting point of the resin. Although high specularity can be obtained, boiling water resistance could not be satisfied. That is, even if the heat of crystallization ΔΗc and the heat of crystal fusion ΔΗπι satisfy at least one of the relations of 15 <ΔΗπι and 5 (ΔHm−ΔHc), When a PBT resin or a PTT resin having a high crystallization rate is not included as a crystalline polyester resin component constituting the material resin layer 14, it is difficult to improve boiling water resistance. Comparative Example 10 is a case where the resin-coated metal plate 11 was manufactured under the same conditions as Comparative Example 9 except that the cooling method after laminating was changed from water cooling to air cooling, and a gentle cooling method was used. As a result, crystallization was promoted, and the boiling water resistance was slightly improved as compared with Comparative Example 9, but the processability was deteriorated. This embodiment has the following effects.

(1) The resin-coated metal plate 11 is formed by laminating a base resin layer 14 mainly composed of a polyester resin on one side of a metal plate 12 via an adhesive layer 13, and a printing layer thereon. 15 are laminated, and a transparent stretched polyester resin layer 16 is laminated thereon. The polyester resin constituting the base resin layer 14 has a clear crystallization peak at the time of temperature rise in the measurement by the differential scanning calorimeter in the state of the laminated sheet before being laminated on the metal plate 12. Temperature (T c) and crystal melting peak temperature (Tm) are observed. When the heat of crystallization is AHc (J / g) and the heat of crystallization is ΔΗπι (J / g), (ΔΗπι—AHc) <30.

Therefore, the crystallinity of the base resin layer 14 is limited, and shows a crystal melting peak temperature (Tm). However, in practice, the material becomes molten from a lower temperature, and the metal plate 1 having a temperature of less than Tm + 30 ° C. High specular reflectivity can be obtained even when laminated at a surface temperature of 2. Further, conventionally, high specularity can be obtained at the temperature at the time of laminating a soft vinyl chloride resin film, and the film can be manufactured by effectively utilizing existing facilities. Further, as for printing inks and adhesives, it is possible to divert those used for vinyl chloride resins, thereby reducing product costs.

(2) The base resin layer 14 contains a PBT-based resin as a crystalline polyester resin component. In a state after being laminated on the metal plate 12, 15 く ΔΗηι and 5 （(AHm-He) If at least one of the relational expressions is satisfied, workability and boiling water resistance are improved in addition to excellent specular reflectivity. Therefore, it can be suitably used for a bathroom bath unit and the like.

(3) The base resin layer 14 contains PTT-based resin as a crystalline polyester resin component, and in a state after being laminated on the metal plate 12, 15 <Δ <πι and 5 <(ΔH m-Δ When at least one of the relations of He is satisfied, workability and boiling water resistance are improved in addition to excellent specular reflectivity. Therefore, it can be suitably used for a bathroom bath unit and the like.

(4) Since the transparent stretched polyester resin layer 16 is laminated on the base resin layer 14, deep design is imparted, the surface properties are improved, pigments added to the polyester resin, etc. It is easy to prevent the additive from blowing out.

(5) The transparent stretched polyester resin layer 16 is formed of a biaxially stretched PET resin film. Therefore, it is easy to ensure transparency, smoothness, and scratch resistance of the surface. Further, it becomes easy to form a printing layer by performing so-called back printing.

(6) Since the adhesive layer 17 exists between the base resin layer 14 and the printed layer 15, Adhesion between the oil layer 14 and the printing layer 15 is improved.

(7) Since the base resin layer 14 is made of a colored polyester resin, it is possible to shield the underlying metal plate 12, impart design, improve the color development of the printed layer 15, etc. .

(8) When laminating the laminated integrated sheet S to the metal plate 12 via the adhesive layer 13 with the surface of the base resin layer 14 as an adhesive surface, the surface temperature T s of the metal plate 12 (° C) and the crystal melting peak temperature Tm (V) of the polyester resin constituting the base resin layer 14.

(Tm + 30)> T s holds. Therefore, the resin-coated metal plate 11 can be easily manufactured by using the conventional laminating equipment, and the thermal discoloration and the thermal discoloration of the printing layer 15 and the coating on the back surface of the metal plate can be suppressed.

(9) In addition to excellent specular reflectivity, the polyester resin constituting the base resin layer 14 that has good workability and boiling resistance is a PBT resin or PTT resin as a crystalline polyester resin component. including. Therefore, it is easy to obtain a polyester resin which satisfies the requirements for obtaining the resin-coated metal plate 11 having excellent workability and boiling water resistance in addition to excellent mirror reflectivity.

(10) Since the thickness of the laminated integrated sheet S is 50 to 500 m, the performance as a protective layer for the metal plate 12 and the punching process as the resin coated metal plate 11 Inferior workability can be suppressed. Further, the printed pattern of the printed layer 15 is hardly affected by the color of the metal plate 12 serving as a base.

(11) Since the polyester resin constituting the base resin layer 14 is a blend of a crystalline polyester resin and a non-crystalline polyester resin, the crystal melting peak temperature Tm and the heat of crystallization It is easy to obtain a polyester resin that satisfies the necessary requirements such as AHc and heat of crystal melting ΔHm.

(1 2) The surface temperature T s (° C.) of the metal plate 12 when the laminated integrated sheet S is laminated on the metal plate 12 is the crystal melting peak of the polyester resin constituting the base resin layer 14. Temperature is set higher than Tm. Therefore, it becomes easy to manufacture the resin-coated metal plate 11 having good boiling water resistance and good workability.

The embodiment is not limited to the above, and may be embodied, for example, as follows ₍ 〇 The polyester resin constituting the base resin layer 14 is a crystalline polyester resin and an amorphous polyester resin. The resin is not limited to the one blended with the resin, and a polyester resin in which the ratio of a plurality of kinds of diol components and dicarboxylic acid components is adjusted so as to satisfy the necessary requirements may be used. . 基材 The base resin layer 14 is not limited to the configuration colored with a pigment, but may be colored with a dye.

基材 The base resin layer 14 is not necessarily colored, but may be uncolored.透明 The transparent stretched polyester resin layer 16 may be translucent as long as the printed layer 15 can be visually confirmed from the transparent stretched polyester resin layer 16 side of the resin-coated metal plate 11.

The invention (technical idea) grasped from the embodiment will be described below.

(1) In the invention according to claim 4, the printing layer is formed by performing back printing on the biaxially stretched polyethylene terephthalate resin film.

(2) In the invention according to any one of claims 1 to 6 and the technical idea, the polyester resin constituting the base resin layer is a crystalline polyester resin and a non-crystalline polyester. The system resin is blended.

(3) In the invention according to any one of claims 1 to 6, the laminated integrated sheet has a thickness of 50 to 500 m.

(4) The invention according to claim 7, wherein the surface temperature T s CC of the metal plate when laminating the laminated integrated sheet on the metal plate is a polyester-based material constituting the base resin layer. The temperature is set higher than the crystal melting peak temperature T m (° C) of the resin. The invention's effect

As described in detail above, according to the inventions according to claims 1 to 6, it has excellent specular reflectivity without using a soft chlorinated chloride resin, and furthermore, it uses conventional laminating equipment. Can be manufactured. Further, in the inventions according to claims 2 and 3, in addition to excellent mirror reflectivity, workability and boiling water resistance are also improved. According to the invention of claim 7, the resin-coated metal plate can be easily manufactured by using a conventional laminating facility.

Claims

The scope of the claims

1. A laminated sheet formed by laminating and integrating a base resin layer containing a polyester resin as a main component, a printing layer, and a transparent stretched polyester resin layer in this order. A resin-coated metal plate, wherein the polyester-based resin constituting the base resin layer satisfies the following requirements, wherein the resin-coated metal plate has a configuration laminated on a metal plate via a layer.

In the state of the laminated sheet before being laminated on the metal plate, a clear crystallization peak temperature (T c) and a crystal melting peak temperature (Tm) at the time of temperature rise in the measurement by the differential scanning calorimeter (DSC) Observed, when the heat of crystallization is AHc (JZg) and the heat of crystal fusion is AHm (J / g), (AHm-AHc) <30 holds.

2. The base resin layer contains a polybutylene terephthalate resin as a crystalline polyester resin component, and after being laminated on a metal plate, the heat of crystallization ΔH e and the heat of crystal fusion Δ 2. The resin-coated metal sheet according to claim 1, wherein Hm satisfies at least one of the following relational expressions: 15 <AHm and 5 (AHm-ΔΗc).

3. The base resin layer contains a polytrimethylene terephthalate-based resin as a crystalline polyester resin component, and after being laminated on a metal plate, the heat of crystallization △ He and the heat of crystal fusion 2. The resin-coated metal plate according to claim 1, wherein ΔHm satisfies at least one of 15 AHm and 5 ΔHm-ΔHc.

The resin-coated metal plate according to any one of claims 1 to 3, wherein the transparent stretched polyester resin layer is formed of a biaxially stretched polyethylene terephthalate resin film.

5. The resin-coated metal plate according to any one of claims 1 to 4, wherein an adhesive layer exists between the base resin layer and the printing layer.

6. The resin-coated metal plate according to any one of claims 1 to 5, wherein the base resin layer is made of a colored polyester resin.

7. The method for producing a resin-coated metal sheet according to any one of claims 1 to 6, wherein a base resin layer containing a polyester resin as a main component, a printing layer, and a transparent stretched polyester resin layer. The surface temperature T s (° C.) of the metal sheet when the laminated sheet formed by laminating and integrating the metal sheet on the metal sheet via the adhesive layer with the surface on the base resin layer side as an adhesive surface And the crystal melting peak temperature Tm (° C) of the polyester resin constituting the base resin layer.

A method for producing a resin-coated metal plate that performs lamination in a state where the relationship of (Tm + 30)> Ts is satisfied.