JP5121665B2 - Laminated sheet for resin-coated metal sheet, method for producing the laminated sheet, and designed laminated sheet-coated metal sheet, unit bath member, building interior material, and steel furniture member - Google Patents

Description

  The present invention relates to a laminated sheet for a resin-coated metal plate that can be used for applications such as a unit bath wall material, a ceiling material, and a building interior material, a method for producing the laminated sheet, and a designable laminated sheet-coated metal plate.

  Conventionally, as a design resin-coated metal plate used for a building interior material, a so-called mirror surface design type and an emboss design type have been used. As a type called an embossed design, a single-layer sheet obtained by a calendar film-forming method of soft polyvinyl chloride colored by the addition of a pigment (hereinafter may be abbreviated as “soft PVC”), or The surface of the colored soft PVC sheet is printed, and further, the surface obtained by embossing the surface of a substantially transparent soft PVC sheet obtained by the calendering method is used. I came.

  Soft PVC sheet-covered metal plates have a long-term track record of use, and have the performance that can be used with peace of mind in unit bath applications that are used in harsh usage environments among building materials. In addition to the problem of heavy metal compounds caused by some stabilizers added to plastic resins and the problem of generating hydrogen chloride gas and other chlorine-containing gases during combustion, some plasticizers are particularly useful for interior building materials The use of soft PVC has been restricted due to the volatile organic compound (VOC) problem caused by the stabilizer and the concern of having endocrine disrupting substances.

  Therefore, it has been studied to use a polyester-based resin sheet or the like as a material that can be substituted for a sheet using soft PVC in terms of performance and design. In Patent Document 1, a sheet is obtained by a calendering method. A composition comprising a polyester-based resin that is substantially amorphous is possible. Patent Document 2 proposes a decorative sheet in which a printed pattern is interposed between a sheet made of a transparent amorphous polyester resin and a sheet made of a colored opaque amorphous polyester resin.

  However, when a sheet made of a polyester resin having a glass transition temperature of about 80 ° C. and having no crystallinity is used for a resin-coated metal plate, it may be used in a subsequent process such as laminating to the metal plate. There was a problem that the embossing remarkably occurred during heating. Similarly, since the glass transition temperature of the resin composition is about 80 ° C. and it does not have crystallinity, boiling water is often included as an evaluation test item for resin-coated metal plates used for unit bath applications. When subjected to the immersion test, the resin layer could not retain elasticity, and flow deformation occurred, resulting in a significant appearance defect.

In order to secure the embossing heat resistance against the heating received when laminating to a metal plate with a sheet made of polyester resin, the following methods and the like can be considered.
(1) As a resin composition of a layer to which embossing is applied, a polyester-based resin having crystallinity is used, and by crystallization at the same time as embossing, the elastic modulus of the sheet is maintained up to a temperature reaching the crystal melting point. Use.
(2) By using a polyester resin having a high glass transition temperature as the resin composition of the layer to which embossing is imparted, the temperature in the vicinity of the sheet surface to which embossing is imparted during lamination to a metal plate increases. However, the glass transition temperature of the resin composition should not be exceeded.
(3) The embossing is physically fixed by providing a thermosetting coating layer or the like on the surface of the sheet provided with the embossing.
(4) By increasing the thickness of the sheet, the temperature rise on the sheet surface due to heat transfer from the metal plate heated during lamination is kept low.

  However, the method (3) requires a series of facilities for coating, drying and curing a solvent-based coating agent, which is not preferable in terms of production efficiency. In addition, providing a coating layer with a certain thickness on the embossed design with a bend may cause a decrease in design properties. Further, in a resin-coated metal plate laminated with a sheet provided with a coating layer on the surface May cause a problem in secondary workability such as bending. Further, when the embossed resin layer itself has a composition that cannot withstand boiling water immersion, even when a surface coating layer is applied, this property is not significantly improved.

  As the method of (2), it is possible to increase the glass transition temperature by introducing a dicarboxylic acid component or a diol component having a rigid molecular structure as a copolymer component of the polyester resin, If it is a polyester resin having a glass transition temperature exceeding 1, it is possible to obtain good embossing heat resistance even when it does not have crystallinity, and at the same time, it does not cause flow deformation of the resin layer in a boiling water immersion test I can do it. However, such a polyester-based resin does not exist as a commercial product for general use, and the raw material price becomes expensive.

  Furthermore, the method (4) can be carried out when a soft PVC resin or the like with a low raw material price is used, but it cannot be said to be a preferable method when a polyester resin or the like is used. Therefore, the method (1) is considered most preferable from the viewpoint of performance and cost.

  Patent Document 3 is not related to a sheet for building materials, but among polyester resins, crystalline polyester having polybutylene terephthalate (PBT) as a main repeating unit can provide a desired uneven shape by embossing with high accuracy. In addition, it is mentioned that the shape retention (less embossing return) is excellent when heating in the subsequent step of the unevenness formed by the embossing. And it is pointed out that the reason why the emboss return is small is that the melting point of the PBT resin is high and the crystallization speed is high. From this, it can be predicted that if such a polyester resin is used, it is difficult to cause emboss return in heating in the post-process, so that a resin-coated metal plate having a good emboss design can be obtained, and immersion in boiling water is also possible. It is predicted that a resin-coated metal plate that hardly causes emboss return even when subjected to a test can be obtained.

  In addition, as a method for embossing the PBT resin in the examples of Patent Document 3, a melt-extruded copolymer PBT resin having a melting point of 205 ° C. is laminated on the corona-treated surface of the biaxially oriented polyester film and cooled. It is based on a kind of method of using an embossing roll as a casting roll (take-off roll) of an extrusion film-forming facility that is pressed by an embossing roll. As a casting roll of such an extrusion film forming equipment, using a roll engraved with embossing instead of a normal mirror roll, a method of embossing an extruded sheet is called an extrusion cast embossing method, etc. The method itself is a known method, and basically embossing is applied to the melt-softened low-viscosity thermoplastic resin that has flowed down from the die. Therefore, good emboss transfer can be performed almost independent of the type of thermoplastic resin. It is obtained. Needless to say, the heat resistance of the embossed material varies greatly depending on physical properties such as the crystallization speed and crystal melting point of the resin, as described in Patent Document 3 above.

  On the other hand, patent document 4 is disclosed regarding the metal plate which coat | covered the sheet | seat which consists of PBT-type resin.

  In Patent Document 5, it is said that a sheet made of a thermoplastic resin having a difference between the softening end temperature and the softening start temperature required by TMA is 30 ° C. or less is excellent in the emboss transfer property by the extrusion cast embossing method. A sheet made of a resin is preferred.

  Patent Document 6 discloses a decorative sheet made of a PBT-based resin on the surface side of a two-layer transparent sheet laminated on a base sheet, and is said to have high embossing heat resistance. Paragraph [0022] states that “the lower the thickness ratio of the layer made of PBT resin, the more advantageous from the viewpoint of embossing suitability”, and embossing is given to the PBT layer melted by the extrusion cast embossing method. Instead, it can be interpreted that embossing is given by an offline so-called after-embossing method.

That is, by heating offline, the temperature is lower than the melting temperature of the PBT resin, and the amorphous polyester resin present as the lower layer is heated to a temperature sufficient to melt and soften, and pressed from the surface with an embossing roll. As a result, the amorphous polyester resin layer is deformed, and the surface PBT resin layer is deformed following the deformation of the amorphous polyester resin layer. It is thought that it is disadvantageous for embossing suitability that the thickness of the PBT-based resin layer that is not a layer is too thick.
In the example of Patent Document 6, embossing is carried out by setting the sheet surface temperature to 160 ° C. by using an embossing apparatus that is a separate line from the extrusion film forming equipment, and this temperature is the melting point 225 of homo PBT resin The PBT layer itself is not melted because it is considerably lower than the temperature.
JP 2001-200166 A JP 2002-103544 A JP-A-7-159903 Japanese Patent Laid-Open No. 1-180336 WO00 / 026282 JP 2007-210273 A

  However, in Patent Document 3, when embossing is tried to be fixed by crystallizing at the same time embossing is applied to the PBT resin composition by the extrusion cast embossing method, the surface temperature of the casting roll as the embossing roll is, for example, About 60 ° C or higher and the glass transition temperature of PBT resin (homogeneous PBT resin has a glass transition temperature of about 22 ° C. "Saturated Polyester Resin Handbook" published by Nikkan Kogyo Shimbun, 1989) It is possible to peel the sheet made of the polybutylene terephthalate resin composition in a crystallized state from the casting roll by setting it higher than the above, but the resin composition is sufficiently crystallized. If the cast roll has reached the point where it has not progressed, Since the peeling off the low resin composition having a glass transition temperature from a roll with high surface temperatures than the glass transition temperature in amorphous state, and sticking occurred on the casting roll up stable argument becomes difficult.

  Therefore, in order to avoid the adhesion trouble, the film forming speed cannot be increased so much, and the productivity is lowered. Therefore, by setting the surface temperature of the casting roll higher, it is possible to obtain crystallinity to such an extent that roll peelability does not become a problem in a shorter time, but it is not a single layer extrusion made of PBT resin. When there is a layer made of amorphous polyester resin on the back side by coextrusion, the back side resin at the end part is exposed to the casting roll side due to disturbance of the merge interface at both ends in the sheet width direction. In such a case, the end of the extruded resin may stick to the casting roll, and a problem is likely to occur in stable take-up.

  Moreover, the metal plate of patent document 4 is a use of a can material, and patent document 4 has no description regarding provision of an embossed design. Since it is necessary to improve durability in can applications, it is stated that the entire sheet needs to be in a molten state when heat-sealing with a metal plate. In that case, various embossing methods including the extrusion cast embossing method are described. Even if the embossing imparted by the imparting method is on the surface of the sheet, it will melt and disappear.

  Moreover, in patent document 5, the temperature of the casting roll which is an embossing roll (originally described as a cooling roll) is set to the softening start temperature ± 10 ° C. of the extruded resin composition. This is a technical feature, and in the case of a sheet made only of homo-PBT resin, the temperature of the casting roll is set to about 215 ° C. However, in order to strictly control the temperature with such a high-temperature roll, it seems that a corresponding equipment cost is required. Moreover, in patent document 5, description regarding emboss heat resistance is not made.

  Also, in the case of the embossing method in Patent Document 6, it seems that higher embossing heat resistance can be secured than when embossing is directly applied to the amorphous polyester resin layer. However, since embossing is imparted without melting the surface PBT resin layer, it is considered that the transferability of the emboss having a precise design is limited.

  In view of the above problems, the present invention has good embossing transferability by an extrusion cast embossing method, has an embossed design of a surface with high embossing heat resistance, and also has a design of a pattern by printing. It is an object of the present invention to provide a laminated sheet for a resin-coated metal plate capable of obtaining a resin-coated metal plate having excellent properties, and a design laminated sheet-coated metal plate coated with this laminated sheet. Furthermore, it is an object of the present invention to provide a production method capable of providing the laminated sheet for a resin-coated metal sheet under stable production conditions and without excessive increase in production man-hours.

The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.
In the first aspect of the present invention, in order from the surface side, at least four layers of the following A layer (10), B layer (20), C layer (30), and D layer (40), and printed pattern E (50) A laminated sheet comprising:
Layer A (10) is a polybutylene terephthalate (PBT) resin having a melting point of not less than 70% and not more than 95% by weight of 210 ° C to not more than 230 ° C, based on the mass of the entire resin component in layer A (100% by weight) And a non-oriented and substantially transparent resin layer having a glass transition temperature of 5% by mass or more and 30% by mass or less of 70 ° C. or more, and a thickness of 5 μm or more and 100 μm or less,
The B layer (20) is a non-oriented and substantially transparent resin layer mainly composed of a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher,
The C layer (30) is a non-oriented resin layer having a thickness of 200 μm or less mainly composed of a substantially amorphous polyester-based resin, to which a colorant is added,
The D layer (40) contains 70% by mass or more and 100% by mass or less of a polybutylene terephthalate (PBT) resin having a melting point (Tm) of 210 ° C. or higher and 230 ° C. or lower based on the mass of the entire resin component in the D layer. A non-oriented resin layer having a thickness of 5 μm or more,
Print pattern E (50) is interposed between the B layer (20) and the C layer (30),
A pattern design by emboss transfer is provided on the surface of the A layer (10), and the pattern design is formed by co-extrusion of the A layer (10) and the B layer (20), and at the same time as a casting roll It is formed by using an embossing roll that has a concavo-convex sculpture on the design,
This is a laminated sheet (100) for resin-coated metal sheets having a total thickness of 80 μm or more and 300 μm or less.

  In the laminated sheet (100), the embossing is transferred to the layer A (10) by a so-called extrusion cast embossing method using an embossing roll having an embossed pattern design as an embossing plate on a casting roll during extrusion film formation. It is a layer that can give an embossed design with a high transfer rate and high heat resistance in an extrusion film forming line. As a resin component other than the PBT resin of the A layer (10), a polyester resin having a glass transition temperature (Tg) of 70 ° C. or higher is used because the glass transition temperature of the blend composition is the same as that of the PBT resin single composition. The casting roll can be adjusted to a temperature at which it is possible to reduce the cooling load of the casting roll and to prevent film formation troubles such as condensation on the casting roll surface. This is to prevent the amorphous A-layer resin composition from sticking to the roll at a relatively high film forming speed.

  That is, in this invention, the reliable peeling property from a casting roll is ensured by setting the surface temperature of a casting roll to below the glass transition temperature of the resin composition of A layer (10). Therefore, when peeled from the roll, the crystallization of the PBT resin necessary to ensure the embossing heat resistance is not completed.

  However, in the case of a resin composition containing a PBT resin in the range of the A layer (10) of the present invention, embossing is imparted in an amorphous state, peeled off from a casting roll in an amorphous state, and heated in a subsequent process. Even in the case of performing the crystallization treatment by the method, since the crystallization speed of the blend composition is high, the emboss can be fixed by crystallization without causing the emboss return. Furthermore, since the glass transition temperature of the blend composition of layer A (10) is a little higher than room temperature, it is easy to incorporate a simple heat treatment process into the processes after the casting roll of the extrusion film forming line. In addition, embossing heat resistance can be ensured by crystallization.

  B layer (20) is a layer which makes favorable the heat-sealing property with C layer (30) formed into a film separately, or C layer (30) which provided printing pattern E (50). In addition, a resin layer having a glass transition temperature relatively higher than that of the resin composition of the layer A (10) by using a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher as a main component. It can be. Thereby, when installing the heat processing roll in the process after the casting roll of a film forming line and promoting crystallization of A layer (10), the B layer (20) side is made into the contact surface with the heat processing roll. Thus, a higher temperature heat treatment roll can be used, and the embossing can be more reliably fixed by crystallization.

  The C layer (30) is a layer having a coloring design and a visual concealing function such as a base metal plate by adding a colorant. Moreover, it also has a role which makes the color development of the printed pattern E (50) provided between B layer (20) and C layer (30) favorable. Furthermore, it is a layer for making the heat-fusibility with B layer (20) favorable.

  The D layer (40) is formed by printing an integrated sheet of the A layer (10) and the B layer (20) and an integrated sheet of the C layer (30) and the D layer (40) using an embossing apparatus or the like. (50) is a layer for preventing adhesion to a heated metal roll or the like and preventing a decrease in the tension of the laminated sheet and preventing melt breakage of the sheet when heated for heat fusion lamination and integration. is there.

  The A layer (10) and the B layer (20) are obtained in a state of being laminated and integrated by a coextrusion film forming method from the viewpoint of production efficiency. The printed pattern E (50) gives a design by printing in addition to the uneven design by embossing given to the surface of the A layer (10).

  In the first aspect of the present invention, the C layer (30) and the D layer (40) are preferably formed in a state of being laminated and integrated by a coextrusion film forming method. Thereby, production efficiency can be further improved. Further, the printed pattern E is formed on the surface of the coextruded integrated sheet of the A layer (10) and the B layer (20) and the coextruded integrated sheet of the C layer (30) and the D layer (40) on the C layer (30) side surface. (50) is integrated with the layer B (20) side surface and the layer C (30) side surface to which the printed pattern E (50) is applied as a laminated surface by heat fusion lamination. More preferably it is. This is advantageous in terms of production efficiency and cost without the need for special materials, processes and equipment such as adhesive coating.

  In the first invention, the polyester resin in which the glass transition temperature of the layer A (10) is 70 ° C. or higher, and the substantially amorphous polyester in which the glass transition temperature of the layer B (20) is 70 ° C. or higher. Polyester resin, which is a substantially non-crystalline polyester resin in the C-layer (30), is composed of terephthalic acid or dimethyl terephthalic acid as a main component of a dicarboxylic acid component, and is 20 mol% to 80 mol% of 1,4-cyclohexane. It is preferable that it is a copolyester mainly composed of dimethanol (1,4-CHDM) and ethylene glycol of 20 mol% or more and 80 mol% or less. As a polyester resin used for the A layer (10), the B layer (20), and the C layer (30), a commercially available material is used, thereby obtaining the merit of stability of raw material supply and cost. be able to.

  In 1st this invention, 15 mass% or more melting | fusing point (Tm) is 210 degreeC or more and 230 degrees C or less to B layer (20) on the basis (100 mass%) of the mass of the whole resin component in B layer (20). A polybutylene terephthalate (PBT) resin may be blended, and the resin composition of the B layer (20) may have a glass transition temperature of 60 ° C. or higher.

  When the metal plate coated with the laminated sheet of the present invention is used for a unit bath, it is required to pass a boiling water immersion test as an evaluation item. When the thickness of the B layer (20) consisting essentially of an amorphous polyester resin is relatively thick, the elastic modulus of the B layer (20) is lowered when immersed in boiling water, and the appearance is caused by deformation. There is a risk of defects. On the other hand, by adding 15% by mass or more of PBT resin, which is a crystalline polyester resin and has a high crystallization speed, to the B layer (20), between the B layer (20) and the C layer (30). It is possible to form a layer that does not cause deformation when immersed in boiling water without impairing the heat fusion suitability.

  Moreover, also when B layer (20) is made into a blend composition with PBT-type resin, the co-extrusion sheet of A layer (10) and B layer (20) is made by making the glass transition temperature 60 degreeC or more. The glass transition temperature of the resin composition of the B layer (20) can be relatively higher than the glass transition temperature of the resin composition of the A layer (10). By this, when installing a heat treatment roll in the process after the take-up roll of the film forming line to promote crystallization of the A layer (10), the B layer (20) side is used as a contact surface with the heat treatment roll. Therefore, it is possible to use a heat-treated roll having a higher temperature without causing a risk of sticking to the roll. Therefore, the emboss can be fixed more reliably by crystallization.

  In the first aspect of the present invention, the mass of the entire resin component in the C layer (30) is 100% by mass, and the melting point of 15% by mass to 45% by mass in the C layer (30) is 210 ° C. or higher and 230 ° C. or lower. The polybutylene terephthalate (PBT) resin is preferably blended.

  As in the case of the B layer (20), when the relatively thick C layer (30) is used, the elastic modulus of the resin composition of the C layer (30) decreases when immersed in boiling water, and deformation occurs. May cause poor appearance. On the other hand, by adding a PBT resin that is a crystalline polyester resin and has a high crystallization rate within the above range, the heat fusion suitability between the B layer (20) and the C layer (30) is not impaired. It can be set as the layer which does not have a possibility of producing a deformation at the time of immersion in boiling water.

  2nd this invention is equipped with the laminated sheet (100) for resin-coated metal plates and metal plate (60) of 1st this invention, and the surface at the side of D layer (40) of the laminated sheet for resin-coated metal plates is metal. It is the designable lamination sheet covering metal plate (200) laminated | stacked on the board (60). The designable laminated sheet-coated metal plate (200) of the second aspect of the present invention has an excellent embossed design feeling due to good embossing transferability and also has a design based on the printed pattern E (50).

  The designable laminated sheet-coated metal plate (200) of the second present invention can be suitably used as a unit bath member, a building interior material, and a steel furniture member. Examples of the unit bath member include a unit bath wall material and a unit bath ceiling material, and examples of the building interior material include a closet door material, a partition material, and a general wall material.

3rd this invention is a manufacturing method of the laminated sheet (100) for resin-coated metal sheets of 1st this invention, Comprising:
By laminating the A layer (10) and the B layer (20) by the co-extrusion film forming method, at the same time, by using an embossed roll on which an uneven sculpture of pattern design has been applied as a casting roll, A first step of embossing a design, and
A print layer E (50) applied to the C layer (30) side surface of a coextruded sheet comprising a C layer (30) and a D layer (40) separately laminated by a coextrusion film forming method, and a formed A layer The coextruded sheet comprising (10) and the B layer (20) is heat-sealed with the B layer (20) side surface and the C layer (30) side surface provided with the printed pattern E (50) being laminated. 2 steps,
It is a manufacturing method of the laminated sheet (100) for resin-coated metal plates.
Since the production method of the third aspect of the present invention can provide a laminated sheet for a resin-coated metal sheet having a good design feeling in a simple process, the production efficiency can be improved and the cost can be reduced.

  In the first step of the third aspect of the present invention, the surface temperature of the casting roll is adjusted to a temperature lower than the glass transition temperature of the resin composition of the A layer (10), and after the casting roll of the extrusion film forming equipment, B A heat treatment roll adjusted to a surface temperature lower than the glass transition temperature of the resin composition of the layer (20) and higher than the glass transition temperature of the resin composition of the A layer (10) is provided, and the A layer (10) and the B layer It is preferable to promote crystallization of the A layer (10) by bringing the surface of the coextruded sheet made of (20) on the B layer (20) side into contact with the surface of the heat treatment roll.

  The laminated sheet (100) of the present invention can transfer good embossing with good stability by the extrusion cast embossing method, and can impart emboss heat resistance. Therefore, it has a good embossed design even after being laminated on the metal plate (60). The laminated sheet (100) also has a printing design with the printed pattern E (50). With this laminated sheet (100), it is possible to obtain a designable laminated sheet-coated metal plate (200) having a good embossed design and printing design and causing no problems even in a boiling water immersion test.

Hereinafter, embodiments embodying the present invention will be described.
Note that the laminated “sheet” of the present invention has a thickness in the range of 80 μm to 300 μm, so it is more correct to be described as “film and sheet”, but in this specification, it is generally referred to as “film”. Concerning the range, the single name “sheet” is used for convenience.

  In addition, the expression “non-orientation” does not mean that an orientation treatment such as a stretching operation has been performed in order to impart some performance to the laminated sheet (using a tenter, a longitudinal stretching apparatus, or the like in the post-casting process). Therefore, it does not mean that an orientation treatment such as a stretching operation is intentionally performed), and that an orientation generated by pulling by a casting roll during extrusion film formation does not exist. In addition, the expression “substantially transparent” means that the printed pattern applied to the lower side and the layer having the colored design on the lower side can be visually recognized through the substantially transparent resin layer. In addition, this means that the layer does not significantly lower the design feeling. Specifically, although it depends on the embossed shape to be applied, the total light transmittance measured in accordance with JIS K 7105 is 45% or more in a state where the A layer and the B layer are laminated and the surface is embossed. , Preferably 55% or more, more preferably 70% or more. And haze is 85% or less, Preferably it is 55% or less, More preferably, it is 30% or less.

[Laminated sheet for resin-coated metal sheet]
The laminated sheet 100 for resin-coated metal plates of the present invention comprises at least four layers of an A layer 10, a B layer 20, a C layer 30, and a D layer 40 in order from the surface side, as shown in FIG. In addition, the printed pattern E50 is provided between the B layer 20 and the C layer 30. Below, each layer is demonstrated.

<A layer 10>
The A layer 10 is a general solution in which the composition of the A layer 10 which has been melted and softened by an extruder is caused to flow down from a T die, brought into contact with a casting roll (take-up roll), and then cooled and solidified, and then led to a winding process and the like. It is a layer formed by an extrusion film forming method. In the present invention, various embossed designs are formed on the surface of the A layer 10 opposite to the side laminated with the B layer 20 by using an embossed roll on which concave and convex sculptures of various patterned designs are applied as casting rolls. Is granted. The A layer 10 contains a polybutylene terephthalate (PBT) resin and a polyester resin.

(PBT resin)
The embossing imparted to the surface of the A layer 10 must not cause the embossing return during heating in the subsequent process. For this reason, in the present invention, the resin composition of the A layer 10 is the entire resin component in the A layer 10. The PBT resin having a melting point of 210 ° C. or higher and 230 ° C. or lower is contained in an amount of 70% by mass or higher and 95% by mass or lower based on the mass of It can be said that the A layer 10 is a layer that secures and maintains the embossed design feeling imparted to the surface of the PBT resin by crystallization.

  When the melting point of the PBT resin is too low, the crystallization speed is slowed down and the crystallinity itself is lowered, so that the B layer 20 and the C layer 30 to be described later are heated via the printed pattern E50 in a later step. Due to the lack of heat resistance of embossing when performing the boiling water immersion test for laminating with the metal plate 60, or for the purpose of unit bath use, There is a risk that the embossing that has been applied will return and the design will be reduced. Further, such a PBT resin having a low melting point is expensive in raw material.

  Among the PBT resins in the above melting point range, a so-called homo PBT resin using a single component of terephthalic acid or dimethyl terephthalic acid as a dicarboxylic acid component or 1,4-butanediol as a diol component ( It is particularly preferable from the viewpoints of cost and stable supply that the total amount of each of the acid component and the diol component is 100 mol%, and an unintended copolymerization component may be contained in an amount of several mol%. The melting point of the homo PBT resin measured by a differential scanning calorimeter (DSC) is about 225 ° C., and has the highest melting point among PBT resins obtained as commercially available raw materials. For this reason, the upper limit of the melting point of the PBT resin of the present invention is set to 230 ° C. in order to include fluctuation of the measured value.

  As the homo-PBT resin, various commercially available materials such as “Novaduran 5020H” manufactured by Mitsubishi Engineering Plastics, “Torcon 1200S” manufactured by Toray Industries, and “Duranex 600FP” manufactured by Wintech Polymer can be used. .

  When the ratio of the PBT resin in the A layer 10 is too low, the crystallization rate of the blend resin composition constituting the A layer 10 becomes slow and the crystallinity is lowered, so the melting point of the PBT resin is low. Similarly to the case, there is a possibility that an emboss return problem may occur when receiving heat in a subsequent process. When the A layer 10 is formed of the predetermined resin composition of the present invention, the peelability from the casting roll is set by setting the surface temperature of the casting roll lower than the glass transition temperature of the resin composition of the A layer 10. Can be secured. And when the resin composition of the A layer 10 leaves the casting roll, the crystallization speed of the blended resin composition is high even when crystallization is hardly progressing, so that the post-process of the film forming line, etc. If the crystallization treatment is carried out, the emboss heat resistance by crystallization can be ensured without causing emboss return. In addition, since the glass transition temperature of the resin composition of the A layer 10 is slightly higher than room temperature, it is easy to incorporate a simple heat treatment process such as a heat treatment roll into the process after the casting roll of the extrusion film forming line. In addition, it is possible to ensure the heat resistance of the embossing by crystallization.

  On the other hand, when the PBT resin having the above melting point range is 100% by mass as the resin component of the A layer 10, the heat resistance of the embossing itself can be good, but the glass transition temperature of the PBT resin. However, in the amorphous state, the homo-PBT resin is relatively low at about 22 ° C., and therefore there is a concern that it will stick to the roll unless considerable consideration is given to cooling of the casting roll. In addition, when the roll surface temperature is lowered to, for example, about 15 ° C. so that the amorphous PBT resin does not stick to the roll, condensation water is generated on the casting roll surface, depending on the surrounding environment. In addition, the cost required for cooling the feed water also increases. Therefore, in the present invention, a small amount of a polyester resin having a glass transition temperature of 70 ° C. or higher is blended with the A layer 10 to slightly increase the glass transition temperature of the blend composition, thereby preventing these problems from occurring. It is.

From the viewpoint of production efficiency, the A layer 10 and the B layer 20 described later are preferably formed in a state of being laminated and integrated by a coextrusion film forming method. If the property is too high, the warp when the co-extruded sheet of the A layer 10 and the B layer 20 is subjected to crystallization treatment becomes remarkable, and there is a possibility that the handling in the subsequent process may be hindered.
From the viewpoint of ensuring embossing heat resistance, the blending amount of the PBT resin in the A layer 10 is more preferably 80% by weight or more based on the total amount of the resin components in the A layer (100% by weight), and 85% by weight. % Or more is more preferable. On the other hand, the PBT resin is more preferably 90% by mass or less from the viewpoint of ensuring the stability of peeling from the casting roll and preventing excessive warpage.

  Also, PBT-based resin can obtain better processability than non-oriented crystallized polyethylene terephthalate (PET) resin in the same crystallized state. This is considered to be due to the fact that a giant spherulite is not formed unlike the non-oriented PET resin, the crystal elastic modulus is lower than that of the PET resin, and the crystal region is flexible. From this, the resin composition of the A layer 10 of the present invention containing 70% by mass or more and 95% by mass or less of PBT-based resin is a mode of a metal plate covered with a laminated sheet, and is subjected to secondary processing such as bending processing. In addition, problems such as whitening of bent portions of the resin layer, generation of fine cracks, and cracks are unlikely to occur.

(Resin components other than PBT resin)
As the polyester resin component having a glass transition temperature of 70 ° C. or higher, which is a resin component other than the PBT resin of the A layer 10, the glass transition temperature used as a main component of the B layer 20 described later is substantially 70 ° C. or higher. The same thing as the polyester-type resin which is amorphous can be used. Resin components other than the PBT resin of the A layer 10 are limited in the amount of addition, and unlike the case of the B layer 20, a polyester resin having crystallinity may be used without any problem. In the case of using a highly crystalline resin such as PET, the crystallization of the PET resin proceeds with time, and the workability of the crystal phase is inferior to the workability of the crystal phase of the PBT resin. As a result, the workability of the metal plate coated with the laminated sheet may deteriorate with time. Needless to say, in applications where only mild secondary processing is performed so that the above-described deterioration in workability does not become a problem, a polyester-based resin having crystallinity having a glass transition temperature of 70 ° C. or higher may be used.

  From the viewpoint of securing the peeling stability from the casting roll during extrusion film formation of the A layer 10 without excessively cooling the roll, the above-mentioned preferred polyester series as a resin component other than the PBT series resin of the A layer 10 It is conceivable to use a material having a glass transition temperature higher than that of the resin. However, in actual film formation, the above-mentioned glass transition temperature is about 70 ° C. to 90 ° C. A blend of polyester resin, and almost no problem peeling stability Is obtained. Further, the glass transition temperature of the resin composition of the A layer 10 being higher than necessary requires that the heating temperature be higher in the crystallization process in the subsequent step. Aromatic polycarbonate resins and the like have a high glass transition temperature, but are not preferable because of poor compatibility with PBT resins.

(Additives, etc.)
A crystal nucleating agent may be added to the A layer 10 in order to increase the crystallization speed. Various commercially available organic nucleating agents such as sorbitol and phosphate esters, and inorganic nucleating agents such as fine silica particles. An appropriate amount of a nucleating agent may be added. A general addition amount is in a range of about 0.1 parts by mass or more and 2 parts by mass or less based on the total amount of the resin component of the A layer (100 parts by mass).

  In addition, various amounts of various additives may be added to the A layer 10 as long as the properties are not impaired or in order to further improve physical properties other than the object of the present invention. Additives include phosphorous and phenolic other antioxidants, heat stabilizers, process stabilizers, UV absorbers, light stabilizers, matting agents, impact modifiers, processing aids, metal deactivators, Residual polymerization catalyst deactivators, antibacterial / antifungal agents, antistatic agents, lubricants, flame retardants, those commonly used for resin materials such as fillers, carbodiimides, epoxys, oxazolines What is marketed for polyester resins, such as another terminal carboxylic acid sealing agent or a hydrolysis inhibitor, can be mentioned. Also in these cases, the amount usually used may be added according to the purpose of use.

  Addition of color pigments and dyes to the A layer 10 is optional. However, in the present invention, a colored design having a deep feeling can be visually recognized through a substantially transparent surface layer, and a colored design having a deep feeling can be visually recognized. Since it is the structure which can be used especially preferably for the provision of the design which can visually recognize the provided printed pattern E50, do not add a coloring pigment to A layer 10 so that the visibility of an inner layer or the printed pattern E50 falls. The visual hiding effect of the A layer 10 is preferably not increased.

  The lower limit of the preferable thickness of the A layer 10 is preferably 5 μm or more, more preferably 10 μm or more, and the upper limit is preferably 100 μm or less, more preferably 60 μm or less. If the thickness of the A layer 10 is excessively thin, although it is produced by a coextrusion film forming method with the B layer 20, there is a possibility that stable film forming properties cannot be ensured. On the other hand, if the thickness is too thick, there is no problem in applying the embossed design by the casting roll, but there is a possibility that the warpage of the sheet becomes remarkable when the film is formed integrally with the B20 layer by coextrusion film formation.

<B layer 20>
The function required for the B layer 20 is to improve the heat-sealing property with the surface of the C layer 30 separately formed or the surface of the C layer 30 provided with the printed pattern E50. In addition, a resin layer having a glass transition temperature relatively higher than that of the resin composition of the A layer 10 is mainly formed using a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher. Therefore, when a heat treatment roll is installed in the process after the casting roll of the film forming line to promote crystallization of the A layer 10, the B layer 20 side is used as a contact surface with the heat treatment roll, so that the heat treatment can be performed at a higher temperature. A roll can be used. Thereby, emboss fixation by crystallization of A layer 10 can be achieved more certainly.
Therefore, the resin component constituting the B layer 20 should not stick to the heat treatment roll for promoting crystallization heated to about 60 ° C., and the melting point of the resin composition of the A layer 10 It must be melted and softened by heating to a low temperature of about 190 ° C. to express heat-fusibility.

  For the above reasons, the resin component used in the B layer 20 is preferably mainly composed of a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher. Here, “mainly” refers to 55% of a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher, based on the mass (100% by mass) of the entire resin component of the B layer 20. It means to contain at least 70% by mass, preferably 70% by mass.

  As a substantially non-crystalline (including low-crystalline) polyester-based resin forming the B layer 20, a polyester that does not show a clear crystal melting peak at the time of temperature rise by a differential scanning calorimeter (DSC). Resin and crystallized ones with a slow crystallization rate [1/2 crystallization time measured at 120 ° C. by “Perkin Elmer method” using a differential scanning calorimeter (DSC) is 200 seconds or more. A polyester resin that does not become high in crystallinity when it is subjected to heating for heat fusion lamination in a subsequent process, or a differential scanning calorimeter having crystallinity According to (DSC), it is possible to use a crystal melting heat quantity (ΔHm) observed at the time of temperature rise as low as 10 J / g or less.

  As the polyester-based resin that is substantially amorphous in the B layer 20, terephthalic acid or dimethyl terephthalic acid is mainly used as a dicarboxylic acid component, and 20 mol% to 80 mol% of 1,4-cyclohexanedimethanol (1 , 4-CHDM) and a copolymerized polyester mainly composed of 20 mol% or more and 80 mol% or less of ethylene glycol are preferred from the viewpoint of easy availability of raw materials. Here, the “main body” in the dicarboxylic acid component refers to 70 mol% or more, preferably 80 mol% or more, more preferably 98 mol% or more of terephthalic acid or dimethylphthalic acid based on the total amount of the dicarboxylic acid component (100 mol%). It means containing more than mol%. The “main component” in the diol component is preferably 70 mol% or more, more preferably 80 mol as a total amount of 1,4-CHDM and ethylene glycol, based on the total amount of the diol component (100 mol%). % Or more, more preferably 90 mol% or more.

  When the amount of 1,4-CHDM in the diol component is smaller than this, the characteristics as a crystalline resin become remarkable, and even if the amorphous B layer 20 can be obtained at the time of film formation, heat fusion is performed. It is not preferable because crystallization progresses during heating for lamination and adhesion strength may not be obtained. On the contrary, when the amount of 1,4-CHDM is too large, the crystallinity becomes remarkable and the melting point becomes very high, which is not preferable.

  Among the copolyester resins in the composition range, in the composition where 1,4-CHDM is about 30 mol% of the diol component, no crystallization behavior is observed even in DSC (Differential Scanning Calorimetry) measurement. It is known to show amorphous properties, and examples of the completely amorphous polyester resins include PETG resins. Examples of the PETG resin include “Easter PETG • 6763” manufactured by Eastman Chemical Co., Ltd. This is because a stable supply system of raw materials has been established because it is used in many applications, and as a resin component that is the main component of the B layer 20 of the present invention, the cost is reduced. It can be preferably used. The PETG resin is a polyester resin that forms a compatible blend composition with a PBT resin, and has a glass transition temperature of about 78 ° C.

  However, the present invention is not limited to this, and Eastman Chemical's “PCTG.TM.” which shows crystallinity under specific conditions but can be handled as an amorphous resin under normal extrusion film forming conditions and embossing conditions. 5445 "(copolymerized polyester resin in which the dicarboxylic acid component is terephthalic acid, about 60 mol% of the diol component is 1,4-CHDM, and about 40 mol% is ethylene glycol) can also be used. The “PCTG · 5445” is a polyester resin that forms a compatible blend composition with a PBT resin, and has a glass transition temperature of about 86 ° C.

  In addition to polyester resins having the above composition, PET resins and PBT resins copolymerized with isophthalic acid can also be obtained with low crystallinity or substantially non-crystalline copolymer polyester resins. The higher the copolymerization ratio of isophthalic acid, and thus the lower the crystallinity, the lower the glass transition temperature. Therefore, it is not preferred for use as the main component of the resin composition of the B layer 20 of the present invention.

(PBT resin)
Based on the mass (100% by mass) of the entire resin component in the B layer 20, the B layer 20 is blended with a PBT resin having a melting point (Tm) of at least 15% by mass of 210 ° C. or higher and 230 ° C. or lower. Is preferred. The blending ratio of the PBT resin in the B layer 20 is more preferably at least 20% by mass, further preferably at least 25% by mass, and more preferably at most 40% by mass, and even more preferably at most 35% by mass. is there. By blending the PBT resin, the shape retention of the resin layer of the design-laminated laminated sheet-coated metal plate 200 when in contact with high-temperature water during a boiling water immersion test or the like can be improved. Therefore, such a composition is suitably employed particularly when a metal plate coated with the laminated sheet of the present invention is used for a unit bath or the like.

  However, the total amount of the PBT-based resin is preferably set so that the glass transition temperature of the resin composition used for the B layer 20 is 60 ° C. or higher. This is because the B layer 20 preferably has a function as a layer for facilitating the crystallization of the A layer 10 as described above. In addition, the glass transition temperature of the resin composition of the B layer 20 will fall, so that the compounding quantity of PBT-type resin increases. However, the glass transition temperature of the blended resin composition is not determined only by the blending amount of the PBT resin, but also the glass transition temperatures of the polyester resin and the PBT resin that are substantially amorphous to be used. Therefore, the glass transition temperature of the blend composition is defined as 60 ° C. or higher.

  As the PBT resin, the same PBT resin that can be used for the A layer 10 described above can be used. Also, among them, a so-called homo PBT resin (which may include an unintended copolymer component) using terephthalic acid or dimethyl terephthalic acid as a dicarboxylic acid component and 1,4-butanediol as a diol component. ) Is preferable from the viewpoint of cost and availability. The PBT resin compounded in the B layer 20 and the PBT resin compounded in the A layer 10 may have different compositions, melting points, etc., but this does not provide any characteristics. From the viewpoint of raw material purchase and the simplification of the raw material input equipment of the film forming equipment, it is particularly preferable to use a homo PBT resin in any layer.

  If the amount of the PBT resin blended in the B layer 20 is too large, the crystallinity of the B layer 20 becomes remarkable, and when heated for heat fusion lamination, crystallization proceeds and sufficient adhesion strength is obtained. There is a risk of being lost. Further, as the blending amount of the PBT resin increases, the glass transition temperature of the resin composition of the B layer 20 decreases, and the B layer 20 is present during the crystallization treatment in the extrusion film forming line. The merits of become dilute. On the other hand, if the amount of PBT resin to be blended is too small, there will be no significant difference in the shape retention effect after boiling water immersion test from the case where the B layer 20 is composed only of a substantially amorphous polyester resin. There is no reason to blend.

(Additive)
An appropriate amount of various additives that can be used for the A layer 10 may be added to the B layer 20. Further, for the B layer 20, the addition of coloring pigments and dyes is optional, but it is preferable that the visual hiding effect is not so high that the visibility of the inner layer and the printed pattern E50 is reduced as in the case of the A layer 10. .

  The lower limit of the thickness of the B layer 20 is preferably 3 μm or more, more preferably 5 μm or more, and the upper limit is preferably 100 μm or less, more preferably 50 μm or less. When the thickness of the B layer 20 is excessively thin, although it is produced by the co-extrusion film forming method with the A layer 10, there is a possibility that stable film forming property cannot be ensured. On the other hand, when the thickness of the B layer 20 is too thick, the total thickness of the laminated sheet 100 is restricted from the viewpoint of workability, so that it is necessary to make the other layer thin, and the other layer should take charge. There is a risk of causing functional failure.

<Coextruded sheet consisting of A layer 10 and B layer 20>
As the thickness of the sheet in which the A layer 10 and the B layer 20 formed by the coextrusion method are laminated, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, and the upper limit is preferably 200 μm or less, more preferably. 150 μm or less. If the thickness is smaller than this, there is a risk of causing problems in handling as a sheet, and even if the thickness is made larger than this, the necessary functions are saturated and at the same time, the C layer 30 and the D layer 40 described later. Due to restrictions on the total thickness of these layers, there is a risk that these layers will fail to function.

  Further, the thickness of the sheet in which the A layer 10 and the B layer 20 are laminated is 1.2 times to 2 times the plate depth (maximum depth / Ry value) of the embossing roll from the viewpoint of good transfer of the embossed design. It is preferable that it is about twice. If the thickness is thinner than this, the embossed pattern on the surface opposite to the surface of the sheet that has pressed the embossing roll (in the case of the present application, the surface of the B layer 20) is called “back texture” although it depends on the type of plate. There is a possibility that unevenness due to reflection may occur, and a sheet with remarkable unevenness due to the “back texture” may cause problems during heat-sealing lamination in a later step. That is, the design feeling is reduced due to the entry of bubbles into the thermal fusion laminate interface. In addition, even if the ratio of the sheet thickness to the plate depth of the embossing roll exceeds twice, there are many cases where further improvement in transfer cannot be obtained. Sexual problems become apparent.

  In order to produce a sheet in which the A layer 10 and the B layer 20 are laminated by the co-extrusion film forming method, two melt-kneading extruders equipped with facilities necessary for extrusion molding of a polyester-based resin such as a vent device, A co-extrusion film formation by a feed block method may be carried out using a gear pump, a feed block, necessary connecting conduits, and a single layer T die, or a multi-manifold type T die may be used instead of the feed block method. It may be used for coextrusion film formation.

  In the present invention, an embossing roll in which embossed irregularities of various design patterns are engraved on the surface is used as a casting roll in the above-described film formation, instead of using a metal roll having a mirror finished surface. The two layers of resin melted down from the T-die are taken up so that the A layer 10 side is in contact with the casting roll. At the same time, the emboss of the design is transferred to the surface of the A layer 10 and extruded into a sheet. It is led to a subsequent process such as a winding device usually installed in the production line of the film-formed product.

<Crystalization treatment of A layer 10>
Since the resin composition of the A layer 10 of the present invention is cooled and solidified from a molten state by a casting roll adjusted to a temperature lower than its glass transition temperature, it has high crystallinity at the time of leaving the roll. Not done. However, since it is a layer composed mainly of a PBT resin having a melting point of 210 ° C. or higher, the crystallization speed is high and the crystallization temperature is low. By embedding a simple crystallization treatment step, it is possible to secure the embossing heat resistance by crystallization without causing emboss return easily online.

  As a method for the crystallization treatment, a method by adhesion to a heating roll (heat treatment roll) is particularly preferable because there is little possibility of generation of wrinkles due to crystallization shrinkage. In the present invention, the resin composition constituting the B layer 20 has a relatively higher glass transition temperature than the resin composition of the A layer 10, and the surface on the B layer 20 side is a relatively smooth surface. By making the B layer 20 side an adhesion surface to the heat treatment roll, more efficient crystallization treatment can be performed. However, the B layer 20 is a layer mainly composed of a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher, or a blend composition of the resin and a PBT resin. Since the glass transition temperature is 60 ° C. or higher, the upper limit of the surface temperature of the heat treatment roll is about 60 ° C. However, in the resin composition of the A layer 10 of the present invention, crystallization is sufficiently promoted even at such a temperature, and the heat resistance of the emboss can be ensured without causing the emboss return.

  The crystallization treatment of the A layer 10 may be carried out by adding a hot air blowing device or the like to the steps after the casting roll of the extrusion film production line, not particularly by the above method, but the width shrinkage due to crystallization. It is necessary to pay attention to the occurrence of wrinkles caused by It is also possible to leave the paper tube in which the sheet is wound in a roll shape in a thermostatic chamber adjusted to about 40 ° C. for several hours. There is a risk that the handling of subsequent sheets may deteriorate, such as occurrence of shrinkage or shrinkage wrinkles in the sheet. In addition, when the A layer 10 is passed through an embossing apparatus for heat fusion lamination without being subjected to crystallization treatment, rapid crystallization proceeds on the heating roll of the embossing apparatus at a relatively high temperature. There is a risk that shrinkage wrinkles may occur. Therefore, as described above, it is preferable to perform crystallization treatment in the film production line.

<C layer 30>
The C layer 30 is a layer having a design for coloring by adding a colorant, improving the color development of the printed pattern E50, and a visual hiding function of the metal plate 60 as a base, and the B layer 20 It is also a layer having a function of improving the heat-fusibility of the film. Therefore, the resin component constituting the C layer 30 needs to exhibit flexibility when heated to about 190 ° C. Therefore, crystallization must proceed rapidly during heating for heat fusion lamination, and the melting point should not exceed 190 ° C. In addition, when the printed pattern E50 is applied to the surface of the C layer 30, crystallization rapidly proceeds by heating for solvent drying in the printing process, and the melting point exceeding 190 ° C. may not be exhibited.

  That is, regarding the C layer 30 as well, it is preferable that the polyester layer resin that is substantially amorphous like the B layer 20 is mainly used. Here, “mainly” means that the polyester resin that is substantially amorphous is at least 55% by mass, preferably 70% by mass, based on the mass of the entire resin component of the C layer 30 (100% by mass). Say that more than%. The substantially amorphous polyester-based resin that can be used for the C layer 30 is the same as that that can be used for the B layer 20, and also from the viewpoint of ensuring the heat resistance of the entire laminated sheet. The substantially amorphous polyester resin that is the main component of the layer 30 also preferably has a glass transition temperature of 70 ° C. or higher. In addition, as in the case of the B layer 20, it is preferable to add a certain amount of PBT resin in order to make the boiling water immersion resistance better.

  The resin composition of the C layer 30 may be different from the resin composition of the B layer 20 within the composition range of the resin that can be used as the B layer 20 described above. From the viewpoint of simplification of the materials-related equipment, the resin composition of the B layer 20 and the C layer 30 is preferably the same.

  When the printed pattern E50 is imparted to the surface of the C layer 30, in the case of the C layer 30 consisting only of a substantially amorphous polyester-based resin, from the viewpoint of solvent resistance to the solvent used in the printing ink. Problems with printability are also expected. Moreover, it is preferable to add PBT resin to C layer 30 in the range of 15 mass% or more and 45 mass% or less from the point which ensures the boiling water resistance of the whole lamination sheet, and a minimum is more preferably 20 mass% or more. The upper limit is more preferably 25% by mass or more, more preferably 40% by mass or less, and still more preferably 35% by mass or less. The same applies to the resin composition of the B layer 20 when the printed pattern E50 is formed on the back surface of the B layer 20.

(Coloring agent)
The C layer 30 is an essential layer to which a colorant is added. The pigment to be used may be one generally used for coloring the resin for the above purpose, and the amount added may be the amount generally added for the above purpose. As an example, the tint can be adjusted with various inorganic and / or organic chromatic pigments based on a titanium oxide pigment having a high hiding effect in white-based coloring. In black coloration, lightness is appropriately adjusted with a white pigment such as titanium oxide based on a black pigment such as carbon black, and at the same time, the color is adjusted with various inorganic and / or organic chromatic pigments. be able to.

  Plenty of pigment-kneaded pellets with improved dispersibility by pre-kneading, such as the above-mentioned color masterbatch based on PETG resin, is commercially available. It is preferable from the above point.

  The purpose of adding the colorant is to provide a visual concealing effect for the base in addition to the design of the tint. The visual concealment effect varies in the degree of importance depending on the use, but in the case of an embossed design sheet-covered metal plate for use in interior building materials, it was measured according to JIS K5600 4-1 “Paint General Test Method / Concealment Ratio”. The concealment rate is preferably 0.95 or more in the configuration of the laminated sheet.

  When the concealment rate is lower than this, the color of the base material such as the metal plate 60 is reflected in the color of the laminated sheet 100, and the color of the base changes due to the difference in the processing of the metal plate surface, etc. In addition, the color of the design resin sheet-covered metal plate 200 observed from the surface of the laminated sheet 100 appears to change, which is not preferable. However, in applications where color change due to this reason does not pose a particular problem, the concealment rate need not be 0.95 or more.

  An appropriate amount of various additives similar to those that can be used for the A layer 10 and the B layer 20 may be added to the C30 layer.

  The thickness of the C layer 30 is preferably 40 μm or more, more preferably 60 μm or more, and the upper limit is preferably 200 μm or less, more preferably 150 μm or less. If the thickness is thinner than this, it is necessary to add a large amount of colorant in order to provide a sufficient coloring design and a concealing function for the groundwork, resulting in deterioration of extrusion film forming property and deterioration of workability. When the conductive laminated sheet-covered metal plate 200 is subjected to secondary processing such as bending, defects such as cracks, cracks, and whitening are likely to occur in the resin layer. Moreover, even if the thickness is made thicker than this, the necessary functions are saturated, and at the same time, as described later, the thickness of the laminated sheet 100 as a whole is limited, so that it is necessary to make other layers relatively thin. There is a risk that these layers may fail to function.

<D layer 40>
The D layer 40 heats and laminates the laminated sheet by using an embossing apparatus conventionally used for embossing soft PVC, especially when performing heat fusion lamination. At that time, it functions as an anti-adhesion layer to the heated metal roll, and further prevents a decrease in tension of the laminated sheet 100 heated to the same temperature as that of the conventional soft PVC. Provided to prevent. Further, when the printed pattern E50 is applied to the surface of the C layer 30, it is a layer that functions in the same manner, such as prevention of width shrinkage, during heating for solvent drying in the printing process.
Therefore, the resin composition constituting the D layer 40 should not lose these functions by heating up to about 190 ° C. in an embossing apparatus.

  The D layer 40 contains 70 mass% or more and 100 mass% or less of a PBT resin having a melting point of 210 ° C. or higher and 230 ° C. or lower based on the mass of the entire resin component in the D layer 40 (100 mass%). The melting point is required to be 210 ° C. or higher, and it is preferable to divert an embossing apparatus that has been used for embossing a conventional soft PVC sheet to heat-bonding lamination. In this case, since the temperature at which the sheet is heated by the heater without a support is about 160 ° C. to 190 ° C., sufficient tension is obtained at this temperature. The reason why the upper limit of the melting point is 230 ° C. is that homo PBT having the highest melting point among PBT resins obtained as commercially available raw materials is around 225 ° C.

From the viewpoint of maintaining a high elastic modulus up to the melting point by crystallization and thereby maintaining the tension, the polyester resin that can be used for the D layer 40 is a material having high crystallinity. For example, a homo PET resin or the like may be used. However, since the PBT resin in the melting point range has a relatively high crystallization rate, the blend composition containing 70% by mass or more of the PBT resin is sufficient for the above purpose without increasing the number of steps. It is possible to obtain a sheet in a state crystallized to an extent by an extrusion film-forming method, and it is easy to give the function required for heat-bonding lamination using an embossing device to the D layer 40 Therefore, in the present invention, the PBT resin having the above melting point is used.
In addition, since the heating temperature of the metal plate when laminating the conventional soft PVC sheet to the metal plate was about 235 ° C., when using the PBT resin in the melting point range as the resin composition of the D layer 40, Even the D layer 40 in a crystallized state that does not cause a problem in the embossing apparatus can be laminated on the metal plate 60 without changing the conventional laminating temperature.

  Other reasons for using the PBT-based resin are that, as in the case of the A layer 10, good processability can be obtained even in a crystallized state as compared with the PET-based resin. It can be mentioned that application development has become active and it has become easier to obtain various grades of PBT resin raw materials.

  The D layer 40 contains the PBT resin at a ratio of 70% by mass or more and 100% by mass or less based on the mass of the entire resin component in the D layer 40 (100% by mass). If this ratio is too small, even if the sheet is obtained in a crystallized state, it is difficult to make the melt tension sufficient when the laminated sheet is heated, and during heat fusion lamination using an embossing device There is a risk of wrinkling into the laminated sheet, width shrinkage, melt fracture, and the like. From this point, the PBT resin is more preferably 75% by mass or more. On the other hand, when the thickness of the D layer 40 is relatively large and when the D layer 40 is formed by coextrusion film formation with the C layer 30 described above, the crystallinity of the D layer 40 causes the C layer 30 and the D layer to be formed. The warpage of the co-extruded sheet with the layer 40 becomes significant, and the handleability may deteriorate. From this point, the PBT resin of the D layer 40 is more preferably 95% by mass or less.

  As the PBT resin used in the D layer 40 and having a melting point of 210 ° C. or higher and 230 ° C. or lower, the same PBT resin that can be used for the A layer 10 can be used. Among them, a so-called homo PBT resin (which may include an unintended copolymerization component) using terephthalic acid as a dicarboxylic acid component, or dimethyl terephthalic acid, and a single component of 1,4-butanediol as a diol component. It is particularly preferred to use.

  As the resin component other than the PBT resin of the D layer 40, it is preferable to use a substantially amorphous polyester resin, as in the case of the resin component other than the PBT resin of the A layer 10. Is the same as in the case of the A layer 10. Accordingly, the substantially amorphous polyester resin that can be used for the D layer 40 is the same as that for the A layer 10, and therefore the same as that that can be used for the B layer 20 and the C layer 30. Can be used.

In the present invention, since the A layer 10 is a layer containing PBT resin in an amount of 70% by mass or more and 95% by mass or less, the tension holding layer when the sheet is heated at the time of heat fusion lamination is the D layer 40. In addition, the A layer 10 will also share the function, but in the configuration in which the D layer 40 is omitted (the configuration in which the C layer 30 is the lowest layer), the laminated sheet is heated metal of the embossing device. It adheres to the roll and makes heat fusion lamination difficult.
On the other hand, by making the surface on the A layer 10 side of the laminated sheet the heated metal roll side, the above-mentioned adhesion can be avoided, but the surface of the A layer 10 has unevenness due to embossing imparted by the extrusion cast embossing method. Yes, heat transfer efficiency from the heated metal roll is poor. In addition, performing heat fusion lamination with an uneven sheet on the metal roll side may cause problems such as entrapment of bubbles at the lamination interface and instability of interfacial adhesion strength due to uneven temperature distribution. It is not preferable from the viewpoint of quality.

  The lower limit of the thickness of the D layer 40 is preferably 5 μm or more, more preferably 10 μm or more, and the upper limit is preferably 100 μm or less, more preferably 50 μm or less. If the thickness of the D layer 40 is too thin, even if it is produced by the coextrusion film forming method with the C layer 30, there is a possibility that stable film forming properties may not be ensured, and when the D layer 40 is formed as a single layer, Handling of the sheet becomes difficult. Further, even if the thickness is further increased, the functions necessary for the D layer 40 are saturated, and the total thickness of the laminated sheet is restricted as described later, which may result in failure to express the functions of other layers.

(Additive)
An appropriate amount of various additives similar to those of the other layers may be added to the D layer 40, and a crystal nucleating agent may be added for the purpose of improving the crystallization speed as with the A layer 10. In addition, an appropriate amount of lubricant may be added in order to further strengthen the non-adhesiveness with the heated metal, which is one of the purposes to which the D layer 40 is imparted. As the lubricant, those commonly used for addition to polyester resins can be used. As an example, “Lycowax OP” (manufactured by Clariant Japan), which is a montanic acid-based lubricant, can be mentioned. it can. The addition amount of the lubricant may be a general amount of 0.2 to 3 parts by mass based on the total resin amount of the D layer 40 (100 parts by mass).

  Alternatively, in order to make the tension of the laminated sheet in the embossing apparatus stronger, there is a linear ultra-high molecular weight acrylic resin-based processing aid (for example, “Metablene P-531” manufactured by Mitsubishi Rayon Co., Ltd.) Further, a processing aid such as polytetrafluoroethylene which has been subjected to an easy dispersion treatment that develops into a fibril form (for example, “METABRENE A-3000” manufactured by Mitsubishi Rayon Co., Ltd.) may be added. A general addition amount of about 2 to 3 parts by mass is sufficient.

  Regarding the film formation of the C layer 30 and the D layer 40, as in the case of the A layer 10 and the B layer 20, it is possible to form a film in a state where two layers are laminated by the coextrusion film forming method. To preferred.

<Print pattern E50>
In the laminated sheet 100 of the present invention, the A layer 10 and the B layer 20 are substantially transparent resin layers, and have a design that allows the design of the color of the C layer 30 that is a colored layer to be visually recognized through the transparent layer. By having the printed pattern E50 between the B layer 20 and the C layer 30, it has a printing design. The printed pattern E50 is applied by a known method such as gravure printing, offset printing, lithographic screen printing, rotary screen printing, printing with an inkjet printer, or the like. The pattern is arbitrary, and examples thereof include a pattern imitating a natural material such as a stone pattern and a grain pattern, a geometric pattern, an abstract pattern, and the like. The printing may be partial printing or full printing, and both partial printing and full printing may be performed. The printing pattern E50 can be printed on the entire surface by appropriately selecting a heat-fusible binder resin for the printing ink or by simultaneously applying a heat-fusible coating layer on the printing line. Even in some cases, it is possible to ensure the heat fusion suitability between the B layer 20 and the C layer 30 provided with the printed pattern E50.

  The printed pattern E50 may be formed by printing on the surface of the B layer 20 to be laminated with the C layer 30, but the surface of the A layer 10 formed by coextrusion lamination with the B layer 20 Are formed with embossments with a degree of design that already has a sense of design at the time of film formation, that is, a maximum height (Ry) exceeding several tens of μm. Rather than using a material, it is preferable to print on the surface of the C layer 30 to be laminated with the B layer 20.

<Method for Producing Laminated Sheet 100 for Resin Coated Metal Plate>
A preferable thickness of the entire laminated sheet 100 (A layer 10 + B layer 20 + printed pattern E50 + C layer 30 + D layer 40) is in the range of 80 μm to 300 μm. When the total thickness of the laminated sheet is too thin, it is necessary to add a large amount of pigment mainly to the C layer 30 in order to ensure visual concealment of the base, and as a result, there is a possibility that processability may be lowered. Moreover, when the total thickness is too thin, the embossed design that can be imparted to the surface of the A layer 10 is also limited to those with shallow irregularities, making it difficult to obtain a sufficient design feeling. On the other hand, when the thickness of the laminated sheet is too thick, there is a problem in secondary workability such as difficulty in using a molding die that has been conventionally used for forming processing such as bending of a flexible PVC resin-coated metal plate. May occur.

  The manufacturing method of the lamination sheet of this invention is demonstrated below. First, the A layer 10 and the B layer 20 are formed in a state of being integrated by a co-extrusion film-forming method, and at the time of the extrusion film-forming, a concavo-convex sculpture is given as a casting roll (take-off roll). By using the embossed roll, an embossed design is imparted to the surface of the A layer 10 side. Then, after the casting roll of the film forming line, a crystallization roll whose temperature is adjusted to about 60 ° C. is provided, and the surface on the B layer 20 side is brought into contact with the roll as a contact surface to crystallize the A layer 10. And the heat resistance of the emboss applied to the surface of the A layer 10 is ensured.

  Separately, a co-extruded sheet composed of the C layer 30 and the D layer 40 formed in a state of being laminated and integrated by a co-extrusion film forming method is formed. Next, the print pattern E50 is applied to the C layer 30 side surface and / or the B layer 20 side surface, and the B layer 20 side surface and the C layer 30 side surface are laminated surfaces via the print pattern E50. Lamination and integration are performed by heat fusion lamination. In the heat fusion lamination, it is preferable to use an embossing apparatus 300 used for embossing the soft PVC sheet shown in FIG. 2 from the viewpoint of production efficiency and use of existing equipment.

Each sheet is introduced into the introduction part of the sheet to the heating roll of the embossing apparatus 300, and heat fusion lamination is performed by pressing with a touch roll as appropriate, followed by heating with an infrared heater. By heat-pressing between a pair of rolls on which a roll and a back roll are mounted, and further leading to a cooling roll, the integration of the laminated sheets of the present invention by heat-sealing lamination is completed.
However, the lamination integration of the sheet composed of the A layer 10 and the B layer 20 and the sheet composed of the C layer 30 and the D layer 40 is not necessarily performed by heat fusion lamination in an embossing apparatus, and other equipment or other Thermal fusion laminating may be performed in the process, or laminating with a dry laminating adhesive, or laminating by separately applying an adhesive such as coating and curing an ultraviolet curable adhesive.

  FIG. 2 shows an example of an embossing apparatus 300 that has been generally used for providing an embossed pattern on a soft PVC sheet. The embossing apparatus 300 according to the illustrated embodiment includes a heating roll 310, a take-off roll 320, an infrared heater 330, a nip roll 340, an embossing roll 350, and a cooling roll 360. In the form shown in FIG. 2, an integrated sheet of A layer 10 + B layer 20 to which embossing of a matte design has been applied in advance, and an integrated sheet of C layer 30 + D layer 40 subjected to printed pattern E50 are supplied as described above. Heat fusion lamination is performed by the heating roll 310 of the embossing apparatus. In the present invention, the embossed design on the surface of the laminated sheet on the side of the A layer 10 has already been applied at the time of extrusion film formation, so the embossing roll 350 of the embossing apparatus is a mirror surface roll that has not been subjected to uneven engraving. It is preferable to use instead of etc.

  Further, the embossed design on the surface of the A layer 10 applied at the time of extrusion film formation may be applied by further embossing a new pattern with an embossing apparatus. However, in this case, it is difficult to melt the A layer 10 mainly composed of PBT resin having a maximum temperature of sheet heating in the embossing apparatus of about 190 ° C. and a melting point of 210 ° C. or higher. Therefore, the B layer 20 and the C layer 30 that are melted and softened by heating are deformed by being pressed by the embossing roll, and the A layer 10 is deformed following the deformation of these layers. Therefore, there is a problem in the transferability of the emboss having a precise design, and when too precise emboss is applied by this method, there is a concern about the heat resistance of the emboss. For this reason, a relatively precise embossed design is applied by the cast embossing method at the time of extrusion film formation, and a pattern with a relatively rough pattern embossing that does not impair the design feeling even if some embossing returns occurs. It is preferable to add with an embossing apparatus.

  The C layer 30 of the present invention has a thickness of a certain level or more due to the necessity of ensuring visual hiding by adding a colorant, and is designed as a layer that exhibits flexibility when heated up to 190 ° C. Thus, it is possible to overlay a new embossed pattern with an embossing device in this way.However, as described above, the embossed design is mainly given only during extrusion film formation. It is good to consider that the embossed pattern is given by the processing device.

  Further, the embossed concave portion of the surface of the A layer 10 is given a colored design by so-called wiping printing, or a glossy wiping ink is used to give a glossy design feeling only to the concave portion. A dull wiping ink may be used to impart a design feeling that emphasizes the shadow of the recess. From the viewpoint of durability, the colored ink formed in the embossed recesses by wiping printing and / or the transparent ink layer used for the gloss preparation is formed with an ink using a two-component curable urethane resin as a vehicle. Preferably, it may be formed using a one-component ink composed of a polyester resin, a vinyl chloride resin, an acrylic resin, or the like.

  Here, as the pigment used in the colored ink, a pigment used for a normal printing ink can be used. Giving wiping printing to the embossed recesses of the laminated sheet for resin-coated metal sheets has been carried out since the era of embossed design sheets using soft PVC sheets. The wiping ink layer can be applied by various known methods such as a doctor blade method and a roll coating method.

<Designable laminated sheet-coated metal plate 200>
By laminating the D layer 40 side of the laminated sheet of the present invention on the metal plate 60 using an adhesive, the designable laminated sheet-coated metal plate 200 is obtained.
Examples of the metal plate 60 used in the present invention include a hot rolled steel plate, a cold rolled steel plate, a hot dip galvanized steel plate, an electrogalvanized steel plate, a tin plated steel plate, an aluminum / zinc alloy plated steel plate, an aluminum / magnesium / zinc alloy plated steel plate, and a stainless steel plate. Various steel plates, aluminum plates, aluminum alloy plates, aluminum alloy clad plates, titanium alloy plates, nickel alloy plates such as Hastelloy, magnesium alloy plates, etc. can be used, and these are used after the usual chemical conversion treatment You may do it. Although the thickness of the metal plate 60 varies depending on the use of the designable laminated sheet-coated metal plate 200, it can be selected in the range of 0.1 mm to 10 mm, and is usually about 0.25 mm to 1.6 mm for interior building materials. The thickness is used.

  A method for laminating the laminated sheet 100 on the metal plate 60 is not particularly limited, but laminating with an adhesive 70 is common. As the adhesive 70, heat curable adhesives such as acrylic adhesives, epoxy adhesives, urethane adhesives, polyester adhesives, and the like conventionally used for laminating a soft PVC sheet to the metal plate 60 are used. It is preferable to use an agent, and among these, since the sheet is made of a polyester-based resin, a polyester-based adhesive can be particularly preferably used. Regarding the laminating method, the conventional method is preferable from the viewpoint that existing facilities can be used. That is, using a commonly used coating facility such as a reverse coater or a kiss coater on the metal plate 60, the adhesive film thickness after drying is 1 μm to the surface of the metal plate 60 on the side where the laminated sheet 100 is bonded. The above thermosetting adhesive is applied so as to have a thickness of about 10 μm.

  Next, the coated surface is dried and heated by an infrared heater and / or a hot air heating furnace, and the surface temperature of the metal plate is maintained at a temperature of about 225 ° C. to 240 ° C., and immediately, using a roll laminator, the D layer of the laminated sheet Designed laminated sheet-covered metal plate by cooling while moisture contained in the laminated sheet is heated and does not cause foaming by a method that allows rapid cooling such as coating and water injection so that the 40 side becomes an adhesive surface 200 can be obtained.

  Moreover, the designable laminated sheet-covered metal plate 200 of the present invention has good workability, and is constructed of unit bath members such as unit bath wall materials and unit bath ceiling materials, closet door materials, partition materials, panel materials, and the like. It can be suitably used as a housing member for home appliances such as interior materials, door materials, steel furniture members, AV equipment, and air conditioner covers.

  In order to describe the present invention more specifically and in detail, the following examples are given, but the present invention is not limited to these examples.

<Examples 1 to 25 and Comparative Examples 1 to 14>
(Preparation of coextruded sheet of A layer + B layer)
The coextruded sheets of layer A and layer B used in Examples 1 to 25 and Comparative Examples 1 to 14 are two co-directional twin-screw kneading extruders (manufactured by JSW Co., Ltd.) having vent devices at two locations with a cylinder diameter of φ65 mm. No. "TEX-65") was obtained by a general method in which the resin flowing out from the T-die was taken up by a casting roll (take-off roll) by feed block type coextrusion. The cylinder set temperature of the extruder is 200 ° C. on the feed side and 250 ° C. on the base side, and the same applies to both extruders. The T die set temperature was 250 ° C. as a reference, and the temperature setting in the width direction was finely adjusted as appropriate according to the state of film formation such as thickness distribution. The set temperature of various connecting conduits and feed block parts is also 250 ° C. As the A layer, only the sheets using a-19 and a-20 in Table 1 have a high melting point of the raw material. Therefore, the temperature setting of the T die and the feed block portion is set to 265 ° C., and the A layer The temperature on the base side of the side extruder and the connecting conduits were set to 265 ° C.

  The temperature of the casting roll is adjusted by circulating water at 20 ° C., and the surface of the casting roll has a centerline average roughness (Ra) of 9 μm and a maximum height (Ry) of 54 μm. It is a surface-plated metal roll having a diameter of 400 mm engraved with embosses for imparting unevenness of the abstract pattern. The molten resin flowing down from the T-die is extruded such that the side forming the A layer becomes the casting roll side, and the surface temperature of about 40 ° C. is obtained by circulating water on the side forming the B layer. The silicone rubber touch roll adjusted to be in contact with each other. The sheet flow speed (film forming speed) at the time of leaving the casting roll was 30 m / min.

  Using the heat treatment roll installed in the subsequent process of the casting roll equipment of the film forming line, the A layer is crystallized online on the sheet comprising the A layer and the B layer thus co-extruded and formed. did. The heat treatment roll is a surface-plated metal mirror surface roll having a diameter of 500 mm, the temperature of which is adjusted by circulating water at 60 ° C. The heat treatment roll is passed so that the surface of the B layer side of the sheet composed of the A layer and the B layer becomes a contact surface, and the sheet is in contact with approximately 65% of the roll surface length.

The resin composition of the A layer and the thickness of the A layer are shown in Table 1, and the resin composition of the B layer and the thickness of the B layer are shown in Table 2. Moreover, although the glass transition temperature of the resin composition of A layer was described in Table 1, in the resin composition which has PBT resin as a main component, crystallization progresses only by touching, etc. in an amorphous state. On the other hand, in the practice of the present invention, it is meaningless to measure the glass transition temperature in the crystallized state, and in many cases, it is in the amorphous state of homo PBT. Estimated value from the measured value of the glass transition temperature of the glass transition temperature of the polyester resin other than PBT blended in the A layer (polyester resin having a glass transition temperature of 70 ° C. or higher). (Interpolated value) was unavoidable. The estimated value is shown in parentheses in Table 1 as “(22)”. Regarding the actually measured glass transition temperature, after the coextruded sheet of layer A and layer B left the take-up roll, a part of the sheet was cut with scissors before reaching the heat treatment roll, and a microtome was used from the layer A side. This is measured using a machined resin. The measurement itself is performed by a differential scanning calorimeter in the same manner as the measurement of the glass transition temperature of the raw material resin described later.
Table 2 shows the measured values and estimated values of the glass transition temperature of the resin composition of the B layer.

  The combinations of layer A and layer B in Examples 1 to 25 and Comparative Examples 1 to 14 are shown in Table 3. Further, the ratio of the thickness of the coextruded sheet composed of the A layer and the B layer to the embossed plate depth of the casting roll “(A layer thickness (μm) + B layer thickness (μm)) / maximum height Ry value of the embossing roll. (Μm) ”is also shown in Table 3. In addition, the comparative example 13 uses the sheet | seat which consists of a B layer single layer without an A layer, and the comparative example 14 uses the sheet | seat which consists of an A layer without a B layer.

(Preparation of coextruded sheet of C layer + D layer)
Regarding the coextruded sheet of the C layer and the D layer, coextrusion film formation was performed in the same manner as in the case of the coextruded sheet of the A layer and the B layer. The extruder used and the temperature setting were the same as those for the A and B layers, but the casting roll had a satin surface with a centerline average roughness (Ra) of 1 μm and a maximum height (Ry) of 6 μm on the surface. A roll engraved with embossing to give unevenness is used, and this embossing is not for the purpose of giving an embossed design, in order to improve the fixability of the printing ink when giving the printed pattern E, And it is for giving a slipperiness to a sheet and making winding property good. The side that forms the C layer is extruded so that it becomes the casting roll side, and the temperature of the roll is adjusted by circulating water at 20 ° C., and the temperature depends on the change in the resin composition of the C layer. Fine adjustments are made accordingly. A silicone rubber touch roll is brought into contact with the side on which the D layer is formed.

The resin composition of the C layer consists of 75% by mass of Easter PETG · 6763 and 25% by mass of Novaturan 5020H, based on the total resin component of the C layer (100% by mass), and 28 parts by mass of a titanium oxide white pigment It is colored white by the addition of (a value in which the total amount of the resin components of the C layer is 100 parts by mass). The thickness of the C layer is 60 μm.
The D layer is composed of 10% by mass of Easter PETG • 6763 and 90% by mass of Novaduran 5020H, and has a thickness of 10 μm and has no pigment component.

  After forming a co-extruded sheet of the C layer and the D layer, an abstract printed pattern E was imparted to the surface of the C layer by gravure printing using an acrylic / urethane printing ink. There was no particular problem with heating up to about 80 ° C. in a hot air heating furnace for printing suitability with a gravure printing machine or solvent drying.

The raw materials used in the above Examples and Comparative Examples are as follows.
(Easter PETG · 6763 (Easter 6763))
A non-crystalline polyester resin manufactured by Eastman Chemical Company. The dicarboxylic acid component is terephthalic acid, which is about 30 mol. % 1,4-cyclohexanedimethanol, about 70 mol. % Is ethylene glycol. No melting point is observed and the glass transition temperature is 78 ° C.

(PCTG · 5445)
It is a polyester resin that can be handled as a substantially non-crystalline polyester resin manufactured by Eastman Chemical Company. The dicarboxylic acid component is terephthalic acid, which is about 65 mol. % 1,4-cyclohexanedimethanol, about 35 mol. % Is ethylene glycol. No melting point is observed and the glass transition temperature is 86 ° C.

(FLX-92)
A substantially amorphous polyester elastomer manufactured by Bell Polyester Products. The dicarboxylic acid component is terephthalic acid, and about 26 mol% of the diol component is 1,4-cyclohexanedimethanol, about 68 mol% is ethylene glycol, and about 6 mol% is polytetramethylene glycol having a number average molecular weight of about 1000. . The measured glass transition temperature was 19 ° C. and no melting point was observed.

(Novaduran 5020H)
(Homo) polybutylene terephthalate resin manufactured by Mitsubishi Engineering Plastics. The melting point is 225 ° C. A clear glass transition temperature could not be confirmed in the crystallized raw material pellets. This is probably because the crystallinity is high and the volume of the amorphous region is small.

(Juranex 500JP)
It is an isophthalic acid copolymerized polybutylene terephthalate resin manufactured by Wintech Polymer. The melting point is 204 ° C.

(BK-2180)
This is an isophthalic acid copolymerized polyethylene terephthalate resin manufactured by Mitsubishi Chemical Corporation. The melting point is 247 ° C. and the glass transition temperature is 76 ° C.

(RT-553)
This is a (homo) polyethylene terephthalate resin manufactured by Nippon Unipet. The melting point is 253 ° C. The glass transition temperature or melting point of each raw material is measured by the following method.

(Measurement of glass transition temperature (Tg))
Using a differential scanning calorimeter “DSC-7” manufactured by PerkinElmer, 10 mg of a sample was -40 ° C. to 250 ° C. at a heating rate of 10 ° C./min according to JIS K-7121 “Method for measuring the transition temperature of plastic”. The temperature was raised to ℃, held at 250 ℃ for 1 minute, then cooled down to -40 ℃ at a cooling rate of 10 ℃ / min, held at the same temperature for 1 minute, and then the thermogram when the temperature was raised again at 10 ℃ / min. From this, the glass transition temperature (Tg) was determined. Only BK-2180 was measured in the same manner after the temperature was raised from −40 ° C. to 270 ° C. at the same rate of temperature rise and held at 270 ° C. for 1 minute. Each raw material pellet is used as it is as a sample.

(Measurement of melting point (Tm))
Using a differential scanning calorimeter “DSC-7” manufactured by PerkinElmer Co., Ltd., a 10 mg sample was heated at a rate of 10 ° C./min according to JIS K-7121 “Method for measuring transition temperature of plastic / determining melting temperature”. The temperature was raised from −40 ° C. to 250 ° C., held at 250 ° C. for 1 minute, cooled to −40 ° C. at a cooling rate of 10 ° C./minute, held at the same temperature for 1 minute, and then raised again at 10 ° C./minute. The melting point (Tm) was determined from the thermogram when warmed. Only BK-2180 was measured in the same manner after the temperature was raised from −40 ° C. to 270 ° C. at the same rate of temperature rise and held at 270 ° C. for 1 minute. Each raw material pellet is used as it is as a sample.

(Heat-fusion lamination of A layer + B layer coextruded sheet and C layer + D layer coextruded sheet)
Using an embossing device generally used for embossing soft PVC sheets as shown in Fig. 2, a co-extruded sheet consisting of A and B layers and a printed pattern E on the surface of the C layer Lamination was performed by co-extrusion sheet consisting of the C layer and D layer. However, instead of the embossing roll 350 in FIG. 2, a metal mirror roll is attached.
The heating roll 310 is set to 120 ° C., and the two kinds of sheets are overlapped by pressing with a silicone rubber touch roll at the introduction portion of the sheet to the heating roll, and temporarily adhered by the heat of the heating roll. It is said. Subsequently, the laminated and integrated sheet is heated by the infrared heater 330 so that the surface temperature immediately before coming into contact with the embossing roll 350 becomes 170 ° C., and the embossing roll 350 having a diameter of 200 mm and the back roll made of hard silicone are heated. Sufficient adhesion strength is ensured by pressing in between. Subsequently, the integrated sheet is guided to a cooling roll, and the series of operations for heat fusion lamination is completed by cooling the sheet.
The embossing roll 350 is temperature adjusted to 90 ° C. by a hot water circulator, and the cooling roll is similarly temperature adjusted to 40 ° C.

(Preparation of a designable laminated sheet-coated metal plate)
A commercially available heat-curable polyester-based adhesive for a soft PVC-coated metal plate was applied to a metal surface on which the laminated sheet was bonded so that the adhesive film thickness after drying was in the range of 1 μm to 3 μm. Next, the metal sheet is introduced into an infrared heater and a hot-air heating furnace, the coated surface is dried with a solvent, and heated, and the surface temperature of the metal sheet is maintained at 235 ° C., and a laminated sheet is immediately used using a roll laminator. The D layer side surface of was coated as an adhesive laminate surface. Then, the cooling by water jet was performed immediately and the designable lamination sheet coating metal plate was obtained. As the metal plate, an electrogalvanized steel plate having a thickness of 0.45 mm was used.

(Evaluation of laminated sheet for resin-coated metal sheet and design-coated laminated sheet-coated metal sheet)
Each of the following items was evaluated for the laminated sheet for resin-coated metal sheet and the designed laminated sheet-coated metal sheet obtained in the above Examples and Comparative Examples. The results are shown in Table 4.

(1) Adhesiveness to casting roll (embossing roll) A state in which the laminated resin of the A layer 10 and the B layer 20 cooled and fixed from the T-die is peeled off from the casting roll and led to the subsequent process. It was observed visually. “○” indicates that the sheet shows a good release state without sticking to the roll, and “△” indicates that the sheet is slightly sticky but can be produced without any problem. “×” was assigned to the case. The evaluation results are shown in Table 4. In addition, subsequent evaluation was not implemented about what the adhesion to the casting roll of the co-extrusion sheet | seat of A layer and B layer was remarkable.

(2) Adhesiveness to the heat treatment roll After the laminated resin of the A layer 10 and the B layer 20 is wound around the heat treatment roll installed in the subsequent step of the casting roll of the extrusion film forming line, it is peeled off from the heat treatment roll and then the subsequent step. The state led to was visually observed. “○” indicates that the sheet shows a good release state without sticking to the roll, and “△” indicates that the sheet is slightly sticky but can be produced without any problem. “×” was assigned to the case. The evaluation results are shown in Table 4. In addition, about the thing with which the adhesion to the heat processing roll of the coextruded sheet of A layer and B layer was remarkable, subsequent evaluation was not implemented.

(3) Handling property of A layer + B layer coextruded sheet (strength of warpage)
The A layer + B layer coextruded sheet was cut into 15 cm (TD direction) × 30 cm (MD direction) and placed on a surface plate, and the degree of warpage was observed. When the warpage is strong and it becomes completely cylindrical, or when it becomes an arch shape with a height of 10 cm or more from the surface plate surface, the handling property is bad, and “x” is less than 10 cm, but the warpage is 5 cm or more. Is “△”, and in the case of warping less than that, the handling is good and “◯” is given. The “TD direction” refers to the width direction of the sheet (Transverse direction), which is a direction orthogonal to the MD direction. The evaluation results are shown in Table 4. In addition, about the thing which the curvature of the A layer + B layer integrated sheet | seat was remarkable and produced the trouble in the post process, subsequent evaluation was not implemented.

(4) Embossing transfer rate by extrusion cast embossing method Embossing unevenness imparted to the surface of the A layer side of the coextruded sheet of layer A and layer B was measured with a surface roughness meter ("Surfcoder" SE-40D, manufactured by Kosaka Laboratory). The maximum height Ry1 (μm) was determined. On the other hand, the maximum height of the embossed plate roll (casting roll) was Ry0 (μm), and (emboss transfer rate: Ry1 / Ry0 × 100 (%)) was calculated. “◯” when the transfer rate is 80% or more, and the transfer rate is less than 80%, but “Δ” when a visually good embossed design is applied, and the transfer rate is less than 80%. Yes, the case where the embossed design feeling is clearly inferior visually is indicated by “x”. The evaluation results are shown in Table 4.

(5) Thermal fusion lamination suitability: adhesion resistance Using the embossing apparatus shown in FIG. 2, a coextruded sheet composed of A and B layers, and a coextruded sheet composed of C and D layers provided with a print pattern When the heat-bonding lamination was performed, the laminated sheet adhered to the heating roll 310 became difficult to peel, and the peeling was possible but the sheet was markedly stretched and deformed. "Slight adhesion was indicated, but the work could be continued, and the sheet stretch / deformation was in a range that did not cause any practical problems. . Moreover, subsequent evaluation is not implemented about the thing which the lamination sheet adhered to the heating roll and it became difficult to peel. The evaluation results are shown in Table 4.

(6) Thermal fusion lamination suitability: fusing resistance When performing thermal fusion lamination with the embossing apparatus shown in FIG. 2, the sheet melted during heating of the sheet by the heater 330, and the remarkable elongation of the sheet Those with wrinkles, etc. were evaluated as “x”, those with slight sheet elongation / width shrinkage, etc., which were in a practically acceptable range, “△”, those without these problems were “ ○ ”. No further evaluation was performed for those evaluated as “x” in this evaluation. The evaluation results are shown in Table 4.

(7) Suitability for heat-sealing lamination: presence or absence of air bubbles. Observation by visual observation from the surface of the laminated sheet for resin-coated metal sheet that has completed heat-sealing lamination as described above, In the case where a large number of air bubbles are embraced at the lamination interface of the co-extruded sheets of the C layer and the D layer having the printed pattern E, and the design feeling is significantly reduced due to this, “×” “A” was evaluated when “B” was slightly held but there was no particular hindrance to the design feeling, and “B” was evaluated when no bubble was held. The evaluation results are shown in Table 4.

(8) Adhesive strength at the interface of heat-sealing lamination Using a 20 mm × 100 mm design laminated sheet-coated metal plate as a test piece, “JIS Z-0237, Adhesive Tape, Adhesive Sheet Test Method—180-degree peeling adhesion to test piece The peel strength was measured in accordance with the measurement width of 20 mm, and the thermal adhesion interface adhesion strength between the B layer 20 and the C layer 30 with the printed pattern E interposed therebetween was evaluated. “○” indicates that the adhesive strength is 10 N / 20 mm or more and sufficient adhesive strength is obtained. Adhesive strength is greater than 5 N / 20 mm and less than 10 N / 20 mm. Evaluation was made as “Δ” when it was determined that there was no problem, and “X” when the adhesive strength was determined to be insufficient at 5 N / 20 mm or less.

(9) Emboss remaining rate after lamination (emboss heat resistance)
The emboss irregularities given to the surface of the layer A side of the laminated sheet (A + B + E + C + D) that has been integrated by heat-fusion lamination using an embossing device was measured with a surface roughness meter ("Surfcoder" SE-40D manufactured by Kosaka Laboratory). ), And after the laminate sheet was laminated to a metal plate, the roughness measurement was performed again. The maximum height before lamination was Ry1 (μm), and that after lamination was Ry2 (μm). The residual rate was determined (residual rate: Ry2 / Ry1 × 100 (%)). The case where the residual rate is 80% or more is “◯”, the residual rate is less than 80%, but the case where it is not visually recognized as a remarkable abnormality is “△”, the residual rate is less than 80%, The case where the design feeling of embossing is clearly lowered visually is indicated by “x”. The evaluation results are shown in Table 4.

(10) Emboss remaining rate (embossing heat resistance) after immersion in boiling water and appearance evaluation A laminated sheet (A + B + E + C + D) laminated with a laminated sheet (A + B + E + C + D) is cut into a size of 100 mm × 100 mm. For 3 hours. After taking out and drying, the embossed unevenness given to the surface of the A layer side was measured with a surface roughness meter (manufactured by Kosaka Laboratory, “Surfcoder” SE-40D), and after the lamination measured in the evaluation item (9) Based on Ry2 (μm) as the maximum height, the residual ratio of emboss after immersion in boiling water was determined. (Residual rate: Ry3 / Ry2 × 100 (%), where the measured value of the maximum height after immersion in boiling water is Ry3 (μm)).
The case where the residual rate is 80% or more and there is no deformation due to softening / flow of the resin layer caused by immersion in boiling water other than emboss return, “○”, the residual rate is less than 80% However, when it is not visually recognized as a remarkable abnormality, and the residual rate is 80% or more, but there is a slight deformation due to softening / flow of the resin layer due to boiling water immersion. “△”, the residual rate is less than 80%, and the design feeling of embossing is clearly lowered visually, and regardless of the residual rate, it is remarkably caused by the deformation caused by softening and flow of the resin layer. The case where the designability is reduced is indicated by “x”.

(11) Bending workability of resin-coated metal sheet An impact adhesion bending test is performed on the prepared designable laminated sheet-coated metal sheet, and the surface state of the laminated sheet in the bent portion is visually determined. “○”, a case where a slight crack occurred was evaluated as “Δ”, and a case where a crack occurred was evaluated as “×”. The impact adhesion bending test was performed as follows. Samples of 50 mm × 150 mm are prepared from the length direction and width direction of the design-coated laminated sheet-coated metal plate, respectively, kept at 23 ° C. for 1 hour or longer, and then 180 ° (inner bending radius: 2 mm) using a bending tester. Bending was performed, and a cylindrical weight having a diameter of 75 mm and a mass of 5 kg was dropped on the sample from a height of 50 cm. The evaluation results are shown in Table 4.

(12) Surface hardness (pencil hardness test of resin-coated metal plate)
About the produced designable laminated sheet covering metal plate, it implemented according to JISK5600-5-4: 1999 scratch hardness (pencil method). Drawing in a temperature-controlled room at 23 ° C. using a jig that can draw a load of 9.8 N while maintaining a 45 ° angle with respect to the resin sheet surface of the resin-coated metal plate cut out to 80 mm × 60 mm The surface state of the resin sheet of the portion was visually judged, and “○” indicates that no scratch was found with the B pencil, and B gave a scratch, but the 2B pencil gave no scratch. Items with “△” and 2B pencils with scratches were displayed as “x”. The evaluation results are shown in Table 4.

<Examples 26 to 43, Comparative Examples 15 to 20>
In Examples 26 to 43 and Comparative Examples 15 to 20, the combination of the resin composition and thickness of the A layer and the B layer was fixed, and the resin composition and thickness of the C layer and D layer were changed. Regarding the coextruded sheet of the A layer and the B layer, the same one as in Example 18 (A layer: combination of a-7 in Table 1 and B layer: b-6 in Table 2) was used. A co-extruded sheet of the C layer and the D layer was obtained in the same manner as in the co-extrusion film forming method of the C layer and the D layer in Example 1 described above. The printing pattern E was also applied to the C layer side surface of the coextruded sheet of the C layer and the D layer in the same manner as in Example 1 and the like. There were no particular problems with heating up to about 80 ° C. in a hot air heating furnace for printing suitability with a gravure printing machine or solvent drying. The same applies to the heating and cooling conditions and the laminating method and conditions on the metal plate in the heat fusion lamination integration using the embossing apparatus.

  Table 5 shows the resin composition of the C layer and the thickness of the C layer, and Table 6 shows the resin composition of the D layer and the thickness of the D layer. Table 7 shows combinations of the C layer and the D layer of Examples 26 to 43 and Comparative Examples 15 to 20. Evaluation was performed in the same manner as in Example 1 and the results are shown in Table 8. In addition, about the coextrusion sheet of A layer and B layer, since the same thing as Example 18 is used, the casting roll adhesiveness of the coextruded sheet of A layer and B layer, heat-treatment roll adhesiveness, Evaluation of handling property and emboss transfer rate at the time of film formation was omitted. In Comparative Example 20, a sheet composed of a single C layer without a D layer was used.

<Examples 44 and 45>
In the evaluation of Examples 1 to 25, Examples of the results of enveloping bubbles at the time of heat-sealing lamination in an embossing apparatus, resulting in a significant decrease in design feeling after immersion in boiling water. 8 and the same combination of laminated sheets as in Example 10, and only the casting roll was based on a stone pattern having a center line average roughness (Ra) of 7 μm and a maximum height (Ry) of 41 μm. A coextruded sheet of layer A and layer B was formed under the same conditions except that the surface was subjected to a surface-plated metal roll having a diameter of 400 mm engraved with embossing to give abstract pattern irregularities. This was heat-bonded and laminated using the same C-layer and D-layer coextruded sheet and embossing apparatus as in Example 1 and further laminated to a metal plate to obtain a design-layered sheet-coated metal plate. The conditions for heat-sealing lamination and the conditions for laminating to the metal plate were the same as in Example 1.

  Ratio of thickness of coextruded sheet of layer A and layer B to embossed plate depth of casting rolls of Examples 44 and 45 “(A layer thickness (μm) + B layer thickness (μm)) / Embossed roll maximum “Height Ry value (μm)” is shown in Table 9. The evaluation results are shown in Table 10.

[Evaluation of laminated sheet and embossed design sheet coated metal sheet]
<Examples 1 to 25 and Comparative Examples 1 to 14>
In Comparative Example 13 in which the A layer is not provided, the emboss is transferred to the surface of the B layer made of a substantially amorphous polyester resin by an extrusion cast embossing method. There is no problem in the emboss transfer itself by the casting roll during film formation, and a B-layer sheet having a good emboss transfer rate is obtained. Furthermore, although there was no problem in the heat fusion lamination of the co-extruded sheet of the C layer and the D layer in the embossing apparatus, the heating in the embossing apparatus and the lamination to the metal plate were not performed. Remarkable embossing was caused by the heating at the time, and the design feeling after lamination was lowered.
Even in Comparative Example 14 having no B layer, there was no problem in the embossing transfer itself, but it caused adhesion to the heat-treated roll adjusted in temperature by circulating water at 60 ° C. and was difficult to peel off. It is had.

Comparative Example 4 and Comparative Example 5 are cases where a PBT resin of the A layer has a melting point lower than the range of the present invention, and shows the same tendency as Comparative Example 13 and is also resin-coated. The design feeling in the form of a metal plate is significantly reduced. Fixing the embossed design transferred by the casting roll of the extrusion film forming line by crystallization by using the heat treatment roll because the crystallization speed is slower than the low melting point of the PBT resin of the A layer itself. It is thought that was not possible.
The same applies to Comparative Examples 6 and 7 using a homo-PET resin as the crystalline polyester resin of the A layer.

  Although the PBT resin in the melting point range of the present invention is used, Comparative Example 1 whose blend ratio is smaller than the range of the present invention also shows the same tendency as Comparative Example 13, and the blend composition of the A layer Even when the ratio of the PBT resin in the total is small, it is considered that the embossed design transferred by the casting roll of the extrusion film forming line could not be fixed by crystallization due to the slow crystallization speed. .

  Comparative Example 2 is a case where only the PBT resin is used as the resin composition of the A layer, but initially shows slight adhesion to a casting roll whose temperature is adjusted by circulating water at 20 ° C. However, after 10 minutes, the adhesion to the roll became remarkable and it was difficult to continue the film forming operation. This is because the surface temperature of the casting roll was initially maintained at a temperature slightly lower than the glass transition temperature of the resin composition of the A layer, but the temperature gradually increased while the molten resin composition was drawn from the T die. This is probably because the glass transition temperature of the A layer was exceeded. In addition, the coextruded sheet of the A layer and the B layer collected at the initial stage of film formation had a significant warp and caused a problem in handleability.

  Comparative Example 3 is a case where the set thickness of the A layer is too thin. In the feed block method coextrusion method, the resin composition of the A layer did not sufficiently develop to the end of the coextruded sheet of the A layer and the B layer. The emboss remaining rate after laminating on the metal plate showed a good value at the center in the width direction of the resin-coated metal plate, but the design feeling was significantly lowered at the end.

Comparative Example 8 is a case where a substantially amorphous polyester-based resin having a glass transition temperature lower than 70 ° C. is blended as a resin composition of the A layer, with a homo-PBT resin as a main component, and a blend composition Due to the low glass transition temperature, the casting roll was extremely sticky and film formation was difficult. Further, in Reference Example 9, as the resin composition of the B layer, the PBT resin was blended with a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. as a main component. This was a case where the glass transition temperature of the film became lower than 60 ° C., which caused adhesion to the heat treatment roll, making film formation difficult. The same applies to Comparative Example 10.
Comparative Example 11 is a case where the PBT resin is not blended in the resin composition of the B layer, and it is composed only of a substantially amorphous polyester resin, but the glass transition temperature is lower than 60 ° C. For this reason, adhesion to the crystallization roll was caused, making film formation difficult. The same applies to Comparative Example 12.

  On the other hand, in all of Examples 1 to 25 of the present invention, troubles due to adhesion to the casting roll and heat treatment roll during film formation did not occur, the embossing transfer rate was good, and the A layer and B layer There is no problem with the handling of the co-extruded sheet, and good interfacial adhesion strength is obtained without causing problems in adhesion resistance and fusing resistance during heat-fusion lamination with an embossing device. The embossed return does not occur even when heated in the apparatus or when laminating to the metal plate, so that a good embossed design feeling is maintained, and the design laminated sheet coated metal plate is subjected to boiling water immersion. Even in some cases, a good embossed design feeling is maintained, except for some cases. Furthermore, a design-coated laminated sheet-coated metal sheet having good workability that does not cause a problem even in a bending test and having high surface hardness and good scratch resistance has been obtained.

However, in Examples 1 to 3, the result of the emboss remaining rate after lamination was somewhat low. This is because the resin composition other than the PBT resin increases as the resin composition of the A layer. It shows that emboss heat resistance tends to decrease by decreasing the speed. There was no problem in the embossing transfer rate itself by the extrusion cast embossing method.
Example 7 is a case where the blending amount of the polyester-based resin having a glass transition temperature of layer A of 70 ° C. or higher is small, and shows a tendency of slight adhesion to the take-up roll, but the extrusion film formation becomes difficult. It wasn't. Further, the co-extruded sheet of the A layer and the B layer was warped, but it was not so difficult as to make the work of the subsequent process difficult. Since the blending ratio of the PBT resin is high, a good result is obtained in the emboss remaining ratio after lamination.

  In Example 8, air was trapped at the lamination interface during heat fusion lamination, and as a result, the design feeling of the laminated sheet-coated metal plate was lowered. Moreover, when it used for boiling water immersion, it resulted in the design feeling falling further, but this is considered to be because the bubble which exists in a lamination | stacking interface expanded when it received boiling water immersion. In Example 10, the same problem occurred more remarkably, and the emboss transfer rate itself was slightly worse. However, there is a problem that the thickness of the coextruded sheet of the A layer and the B layer is relatively thin with respect to the plate depth of the embossed plate to be transferred (maximum height of the take-up roll surface / Ry value). It is believed that there is. In other words, the unevenness called “back texture” was prominently generated on the B layer side, which is the surface opposite to the surface on the A layer side to which embossing was imparted, so that air could be easily taken into the lamination interface during heat fusion lamination. It is estimated that It is considered that this problem can be solved by optimizing the thickness of the coextruded sheet of the A layer and the B layer with respect to the embossed plate depth.

  In Example 16, the design feeling after immersion in boiling water was reduced because the resin composition of the B layer was composed of a substantially amorphous polyester resin having a glass transition temperature of 70 ° C. or higher. It is because the elastic modulus of the resin composition of the B layer was lowered when immersed in boiling water due to the use of a relatively thick B layer. Although there was no significant decrease in the residual ratio of embossing, undulations such as waviness were observed on the entire surface. When the thickness of the B layer is relatively thick, it is preferable that about 20% by mass of the PBT resin is blended in the B layer as in Example 17 from the viewpoint of hardly causing a problem in boiling water resistance.

Example 20 is a case where the glass transition temperature of the resin composition of the B layer gradually approaches 60 ° C., and shows slight adhesion to the heat treatment roll of the extrusion film forming equipment. A similar tendency was observed for Example 22 for the same reason.
Example 24 is a case where a polyester copolymer resin having a glass transition temperature of 70 ° C. or higher to be blended in the layer A is not amorphous but a crystalline copolymerized PET resin is used. The emboss remaining rate is the same as in Example 2. In addition, the workability test did not give a bad result.

<Examples 26 to 43, Comparative Examples 15 to 20>
Comparative Example 20 is a case where a single layer sheet having only the C layer without the D layer is used, but the C layer sticks to the heating drum of the embossing apparatus, and the heat fusion lamination cannot be performed. It was.
Comparative Example 19 has a configuration in which the D layer is present, but only the homo-PET resin is used as the resin component of the D layer, which also causes sticking to the heating drum of the embossing apparatus, and heat fusion lamination Could not be implemented. This is probably because the PET-based resin has a low crystallization rate, so that the D layer is brought into contact with the heating drum while being in an amorphous state.

The comparative example 17 is a case where the blend ratio of the PBT resin to the D layer is less than the range of the present invention, and the subsequent operation could not be performed due to the adhesion to the heating drum of the embossing apparatus. The reason for adhesion is considered to be the same as in Comparative Example 19.
The comparative example 18 is a case where the thickness of the D layer is too thin, and it seems that the resin composition of the D layer did not sufficiently develop to the end of the integral sheet of the C layer + D layer in the coextrusion method of the feed block method. Yes, sticking to the heating drum occurred at the end of the laminated sheet. In addition, since the D layer is too thin to function as a tension holding layer during heating, significant elongation and accompanying wrinkling occurred in the sheet, and subsequent operations could not be performed.

Comparative Example 16 is a case where the resin composition of the C layer contains a PBT-based resin in an amount larger than the range of the present invention, and there was no problem in the workability itself of heat fusion in the embossing apparatus. Bubbles were embraced at the fusion interface, and the design feeling was reduced. Furthermore, the adhesion strength at the heat fusion interface was insufficient.
Comparative Example 15 is a case where the total thickness of the laminated sheet (A + B + C + D) is excessively thick beyond the range of the present invention by increasing the thickness of the C layer. When provided, the workability is poor.

  On the other hand, about Examples 26-43 of this invention, the adhesive strength of the favorable interface was obtained, without producing a problem also at the time of the heat-resistant lamination by the embossing apparatus, and fusing resistance. Since the embossing does not return even when heated in an embossing device or when laminating to a metal plate, a good embossed design feeling is maintained, and the laminated metal sheet coated with the design laminated sheet is boiled with water. A good embossed design feeling is maintained except for a part of the case when it is subjected to immersion. Furthermore, a design-coated laminated sheet-coated metal sheet having good workability that does not cause a problem even in a bending test and having high surface hardness and good scratch resistance has been obtained.

  However, regarding the surface state after immersion in boiling water, in Examples 28, 29, and 30 consisting only of a polyester resin in which the resin layer thickness of the C layer is thick and the resin composition of the C layer is substantially amorphous It has been a bad result. These are not the embossed return of the surface of the A layer of the resin-coated metal sheet, but the undulations such as waviness were observed on the entire surface. Even in the case where the C layer is composed of substantially non-crystalline polyester resin, in Example 26 in which the thickness of the C layer is smaller than these, such surface undulation does not occur, Although the thickness is the same as in Example 30, in Example 33 containing 25% by mass of PBT resin as the resin composition of the C layer, the surface is not wavy after immersion in boiling water. Therefore, especially when using the design laminated sheet-coated metal sheet of the present invention for a unit bath application where the surface state after immersion in boiling water is a problem, the resin composition of the B layer and the C layer, or the B layer It is preferable to select one having no problem with respect to the thickness with the C layer from the examples of the present invention.

<Examples 44 and 45>
The same laminated sheet as in Example 8 and Example 10, in which entrapment of bubbles was generated during heat fusion lamination in an embossing apparatus, and as a result, the design feeling after boiling water immersion was significantly reduced. When the embossing plate depth (maximum height / Ry value) of the casting roll was made shallow using the combination of the above, no significant bubble entrapment was observed during heat fusion lamination, resulting in a boiling water immersion test. However, the feeling of design is no longer reduced. The thickness of the co-extruded sheet of the A layer and the B layer is the depth of the embossing roll (maximum height / It was found that the value is preferably about 1.2 to 2 times the value.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. Rather, the laminated sheet for a resin-coated metal plate, a design-coated laminated sheet-coated metal plate, which can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. A unit bath member using the metal plate, a building interior material, a steel furniture member, and a method for producing a laminated sheet for a resin-coated metal plate should also be understood as being included in the technical scope of the present invention. Don't be.

(A) is a schematic sectional drawing which shows one Embodiment of the coextrusion sheet | seat produced by the coextrusion film forming method with the A layer 10 and the B layer 20. FIG. The surface of the A layer 10 is provided with an embossed design provided by a take-up roll of an extrusion film forming facility. (B) is a schematic sectional view showing an embodiment of a co-extruded sheet produced by co-extrusion of the C layer 30 and the D layer 40. A printed pattern D50 is provided on the surface of the C layer 30 side. (C) is a schematic sectional view showing an embodiment in which all four layers of the laminated sheet 100 of the present invention are laminated and integrated. (D) is the designable laminated sheet covering metal plate 200 produced by laminating the laminated sheet of the present invention of (c) on a metal plate. It is the schematic diagram of the embossing apparatus 300 generally used conventionally in order to provide an embossed pattern to the sheet | seat of a soft PVC. In the present invention, the embossing apparatus 300 is used to coextrude the A layer 10 and the B layer 20 and the coextruded sheet of the C layer 30 and the D layer 40 (the printed pattern E50 is applied to the C layer side). Heat-seal lamination can be performed.

Explanation of symbols

10 A layer 20 B layer 30 C layer 40 D layer 50 Print pattern E
60 Metal plate 70 Adhesive layer 10 + 20 Coextruded sheet of A layer and B layer 50 + 30 + 40 Coated sheet 50 provided with printing pattern 50 on the coextruded sheet of C layer and D layer 100 Laminated sheet for resin-coated metal plate 200 Design 310 Laminated sheet-coated metal plate 300 Schematic diagram showing functions of embossing apparatus 310 Heating roll 320 Take-off roll 330 Infrared heater 340 Nip roll 350 Embossing roll 360 Cooling roll

Claims (12)

In order from the surface side, at least four layers of the following A layer, B layer, C layer, D layer, and a laminated sheet consisting of a printed pattern E,
The A layer is a polybutylene terephthalate-based resin having a melting point of not less than 70% by mass and not more than 95% by mass of 210 ° C. to 230 ° C., and 5% by mass to 30% by mass, based on the mass of the entire resin component in the A layer. below the glass transition temperature is a polyester resin is 70 ° C. or higher, a bright resin layer permeable without orientation in the thickness 5μm or 100μm or less,
The B layer is a bright resin layer permeable at unoriented composed mainly of polyester resin is amorphous glass transition temperature of Ru der 70 ° C. or higher,
The C layer is a non -oriented resin layer having a thickness of 200 μm or less, mainly composed of an amorphous polyester-based resin, to which a colorant is added.
The D layer contains a polybutylene terephthalate-based resin having a melting point of 210 ° C. or higher and 230 ° C. or lower based on the weight of the entire resin component in the D layer, and has a thickness of 5 μm or more. A resin layer of
The printed pattern E is interposed between the B layer and the C layer,
A pattern design by emboss transfer is provided on the surface of the A layer, and the pattern design is formed by coextruding the A layer and the B layer by a film forming method, and at the same time, an uneven sculpture of the pattern design is used as a casting roll. It is formed by using the embossed roll that has been applied,
A laminated sheet for resin-coated metal sheets having a total thickness of 80 μm or more and 300 μm or less. The laminated sheet for resin-coated metal sheets according to claim 1, wherein the C layer and the D layer are formed in a state in which they are laminated and integrated by a coextrusion film forming method. A co-extruded integrated sheet of the A layer and the B layer, and a printed layer E of the co-extruded integrated sheet of the C layer and the D layer provided with a printed pattern E, are printed on the B layer side surface. The laminated sheet for resin-coated metal sheets according to claim 2, wherein the laminated surface is formed by heat-sealing lamination with the C-layer side surface provided with the handle E as a laminated surface. The A layer polyester resin having a glass transition temperature of 70 ° C. or more, polyester resin glass transition temperature of the B layer is an amorphous Ru der 70 ° C. or higher, the polyester is amorphous of the C layer The resin is a diol comprising terephthalic acid or dimethylterephthalic acid as a main component of a dicarboxylic acid component, 20 mol% to 80 mol% of 1,4-cyclohexanedimethanol, and 20 mol% to 80 mol% of ethylene glycol. The laminated sheet for resin-coated metal sheets according to any one of claims 1 to 3, which is a copolyester having a main component. Based on the total mass of the resin component in the B layer, the B layer is blended with a polybutylene terephthalate resin having a melting point of not less than 15% by mass and not more than 210 ° C. and not more than 230 ° C., and the resin composition of the B layer The laminated sheet for resin-coated metal sheets according to any one of claims 1 to 4, wherein the glass transition temperature is 60 ° C or higher. The polybutylene terephthalate resin having a melting point of not less than 15% by mass and not more than 45% by mass of 210 ° C. or more and 230 ° C. or less is blended in the C layer, based on the mass of the entire resin component in the C layer. The laminated sheet for resin-coated metal plates according to any one of 5. The design property which is equipped with the lamination sheet for resin-coated metal plates and a metal plate in any one of Claims 1-6, and the surface of the D layer side of this lamination sheet for resin-coated metal plates is laminated | stacked on this metal plate. Laminated sheet-coated metal plate. A unit bus member using the designable laminated sheet-coated metal plate according to claim 7. A building interior material using the designable laminated sheet-coated metal plate according to claim 7. A steel furniture member using the designable laminated sheet-coated metal plate according to claim 7. A method for producing a laminated sheet for resin-coated metal sheets according to claim 3,
Simultaneously laminating the A layer and the B layer by a co-extrusion film-forming method, and at the same time, embossing of the pattern design is imparted to the surface of the A layer side by using an embossing roll on which the pattern design is engraved as a casting roll A first step, and
A coextruded sheet composed of the C layer and the D layer, which are separately laminated by a coextrusion film-forming method, provided with a printed pattern E on the C layer side surface thereof, and the coextruded sheet composed of the formed A layer and B layer A second step of thermally fusing the B layer side surface and the C layer side surface provided with the printed pattern E as a laminate surface;
A method for producing a laminated sheet for resin-coated metal sheets, comprising: In the first step, the surface temperature of the casting roll is adjusted to a temperature lower than the glass transition temperature of the resin composition of the A layer, and after the casting roll of the extrusion film forming equipment, the glass transition of the B layer resin composition is performed. A heat treatment roll adjusted to a surface temperature lower than the temperature and higher than the glass transition temperature of the resin composition of the A layer is provided, and the surface on the B layer side of the coextruded sheet composed of the A layer and the B layer is the surface of the heat treatment roll. The method for producing a laminated sheet for a resin-coated metal sheet according to claim 11, wherein the crystallization of the A layer is promoted by abutting on the resin sheet.

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