JP4087356B2 - Polyester laminated film and laminate thereof - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a laminated film made of a polyester resin, and in particular, a laminated film used on a surface of an indoor wall, bathroom, door, furniture or the like, or affixed to the surface of an electric product such as a refrigerator, and the laminated film and a thermoplastic resin. And the laminate.

  Polyester films are also widely used as packaging materials and various industrial materials because of their excellent transparency, recyclability, and economic efficiency. Since it is particularly safe and does not generate harmful gases during combustion, it is used in a wide range of fields such as food packaging containers and building materials as an alternative material to vinyl chloride. Among them, decorative sheets or decorative films (hereinafter simply referred to as “decorative sheets”) used as surface materials for furniture, furniture, etc. are wood-based materials such as wood, plywood and laminated materials, metal plates, thermoplastic resins, etc. It is used by attaching to the surface of the plate-like material. For example, a pressure-sensitive adhesive layer is provided by a method such as applying a pressure-sensitive adhesive on one side of the decorative sheet, and laminated on the various materials. The laminated body thus obtained may be used after being subjected to a U-cut or V-cut process, followed by a bending process. In addition, a decorative sheet may be attached to a base material formed into a three-dimensional shape by vacuum press molding or pressure press molding. In general, the surface of a decorative sheet is often patterned with printing ink. Therefore, it is necessary for the decorative sheet to have good colorability by printing and the like, bending workability and shape followability, and conventionally, vinyl chloride has been used as an easy material to adjust such characteristics. A laminated film in which a printing ink layer is provided on a film and a transparent vinyl chloride resin film is laminated as a protective film by thermal lamination has been frequently used as a film having excellent design properties.

  However, the film made of the above-mentioned vinyl chloride resin has a large burden on the environment because hydrogen chloride gas is generated at the time of combustion, and incineration treatment in disposal tends to be avoided in a general incineration plant. It is desired.

  For this purpose, many resin compositions and films (sheets) made of a polyester resin have been proposed. For example, Patent Document 1 discloses a film made of an amorphous copolyester resin, and Patent Document 2 further shows a resin composition of an amorphous copolyester and a polyethylene terephthalate resin and / or a polybutylene terephthalate resin. Patent Document 3 discloses a film having a composition in which an organic phosphate triester is blended as a lubricant with a resin composition of an amorphous copolyester resin and a polyethylene terephthalate resin and / or a polybutylene terephthalate resin. ing. Common to these proposals is that when crystalline polyester resin is used, whitening due to crystallization occurs during heat-applied processes and long-term use in summer. Instead, highly flexible metallic materials, etc. The main component is an amorphous copolyester resin having a feature of excellent whitening resistance at the time of bending after bonding.

On the other hand, in Patent Document 4, as a polyester film for metal plate lamination, a layer composed of a mixture of a polyethylene terephthalate resin and a polybutylene terephthalate resin having a specific blending ratio, and a polyethylene terephthalate resin and a polyethylene naphthalate resin having a specific blending ratio. A laminated film of layers composed of a mixture has been proposed. TECHNICAL FIELD The present invention relates to a polyester film and a laminated metal plate for a laminated metal can for food packaging, and the main problem thereof is to obtain a laminated metal can excellent in corrosion resistance and content-keeping and flavor retention. It is in.
JP 2002-103544 A JP 2000-233480 A JP 2002-129002 A JP 2003-291287 A

  Among the above films, the film mainly composed of amorphous copolymer polyester resin has poor solvent resistance, and the film is whitened by the application of printing ink. It was necessary to provide a layer. For the purpose of improving such properties, a blend of a polyethylene terephthalate resin or a polybutylene terephthalate resin with the amorphous copolymer polyester resin has been studied, but these films also have insufficient solvent resistance. In some cases, even when printing ink was not whitened, it contracted to cause a dimensional change, and the design after attaching the cover sheet was not sufficient. Moreover, since the heat resistance of the films as described above is not sufficient in the heat laminating process with the thermoplastic resin, the design properties of the processed laminate may be impaired. The present invention provides a heat-resistant laminated film having printability equivalent to that of the polyester resin film, suppressing yellowing due to ultraviolet rays, and capable of being processed by various lamination methods with a thermoplastic resin. The issue is to provide.

This invention discovered that the film which overcomes the said subject is obtained by providing the layer (B) which consists of a mixture of a polyethylene terephthalate resin layer (A) and a polyethylene terephthalate resin, and a polyethylene naphthalate resin. . That is, the present invention is a laminated film comprising a polyethylene terephthalate resin layer (A) and a layer (B) of a mixture of polyethylene terephthalate and polyethylene naphthalate, and the thickness of the (B) layer is 5 to 30 μm. The ratio of the polyethylene naphthalate resin in the (B) layer is a numerical value calculated by the polyethylene naphthalate ratio (% by mass) in the (B) layer × (B) layer thickness (μm), exceeding 400 and less than 2000. It is preferable that
The present invention also includes (A) the above laminated film with the embossed surface on the layer side, and (A) the above laminated film with the surface printed on the layer side. As a sheet, it is a laminate in which a (A) layer side surface is laminated with a thermoplastic resin typified by ABS resin.

  The laminated film made of the polyester-based resin composition of the present invention has the same printability as films made of other polyester-based resins, hardly causes yellowing due to ultraviolet rays, and heats with a thermoplastic resin such as an ABS resin. In the laminating process, it has heat resistance that does not impair the design of the surface against the heat applied at that time. A laminate in which the laminated film is laminated as a decorative sheet on a thermoplastic resin such as ABS resin is excellent in molding processability and design such as vacuum press molding and compressed air press molding. It can be suitably used for applications such as furniture.

Hereinafter, the present invention will be described in detail.
The polyethylene terephthalate resin (hereinafter abbreviated as “PET resin”) used for the resin composition constituting the laminated film of the present invention is a resin mainly composed of terephthalic acid as a dicarboxylic acid component and ethylene glycol as a main component. Yes, other dicarboxylic acid components such as isophthalic acid and adipic acid and other diol components such as propylene glycol, diethylene glycol and hexamethylene glycol were copolymerized in a small amount within a range of 20% by mass or less with respect to 100 of the total amount of the resin. Things can be used. In addition, those having an intrinsic viscosity of 0.75 or more can be suitably used because the crystallization rate is slow, and whitening at the time of bending or at high temperatures is unlikely to occur.

  Polyethylene naphthalate resin (hereinafter abbreviated as “PEN resin”) is homo PEN resin, isophthalic acid, adipic acid, diphenyl carboxylic acid, diphenyl ether carboxylic acid, diphenyl sulfonic dicarboxylic acid, sebacin as long as heat resistance is not lowered. Use a copolymer obtained by copolymerizing a small amount of dicarboxylic acid components such as acid and naphthalene dicarboxylic acid, and glycol components such as diethylene glycol, hexamethylene glycol, trimethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, and butylene glycol. However, homopolyethylene naphthalate resin is preferred from the viewpoint of economy and heat resistance.

  The laminated film of the present invention has the (A) layer made of PET resin and the (B) layer made of a mixture of the PET resin and PEN resin as described above. Generally, it is a two-layer configuration of (A) layer and (B) layer, but if the surface layer on one side of the laminated film is the (A) layer and the surface layer on the opposite side is the (B) layer Depending on the application, one or more intermediate layers can be provided between the surface layers as long as the properties of the laminated sheet of the present invention are not impaired. As an example of this intermediate layer, a layer made of scrap generated when the laminated film of the present invention is produced or a resin layer containing scrap is cited.

  The thickness of the laminated film of the present invention is not particularly limited, and may be appropriately adjusted in the range of 20 to 500 μm depending on the application, but generally the thickness in the range of 40 to 200 μm is used. On the other hand, the thickness of (B) layer is 5-30 micrometers. When the thickness of the (B) layer is less than 5 μm, sufficient heat resistance when the laminated film is heat-laminated to a thermoplastic resin such as ABS resin cannot be obtained, and on the other hand, it tends to shrink during printing. On the other hand, if the thickness exceeds 30 μm, the formability when the laminate of the laminate film and another thermoplastic resin is formed into a three-dimensional shape by means of vacuum press molding or the like is lowered, and the obtained molded body is obtained. The design property of is inferior.

  (B) The ratio of the PEN resin in the layer is preferably a numerical value calculated by PEN ratio (% by mass) × (B) layer thickness (μm) in the layer (B) exceeding 400 and less than 2000, more preferably. Is greater than 500 and less than 1100. When this value is 400 or less, heat resistance is insufficient during thermal lamination with other thermoplastic resins, and the design of the resulting laminate tends to deteriorate. Is unfavorable, and there is a tendency that the design properties of the obtained laminate are also lowered. From the viewpoint of heat resistance in the case of heat lamination with a thermoplastic resin sheet such as ABS, the ratio × thickness value is preferably more than 700.

  The film of the present invention includes stabilizers, antioxidants, UV absorbers, colorants such as pigments and dyes, silicone oil and alkyl ester release agents, talc and clays, as long as the effects of the present invention are not impaired. Further, a particulate lubricant such as silica or an antistatic agent such as a metal salt of sulfonic acid or polyalkylene glycol can be added.

  In order to produce the laminated film of the present invention, a general method can be used and is not particularly limited. For example, in the two single-screw extruders, the (A) layer and the (B) layer, respectively. And a method of obtaining a laminated film using a feed block and a T die, and a method of obtaining a laminated film using a multi-manifold die. Alternatively, it is possible to obtain a single film of (A) and (B) and laminate these films by a general dry laminating method.

  The laminated film of the present invention is preferably embossed on the (A) layer side in order to improve printability and air escape during lamination with other thermoplastic resin sheets. Although the embossing method is not particularly limited, for example, when the laminated film extruded from the die is taken up in the film-forming process of the laminated film, the surface on the layer side (A) becomes the rubber roll side. Thus, the emboss can be formed on the surface on the (A) layer side through the metal mirror roll / rubber roll under a narrow pressure. The surface roughness of the (A) layer side surface is preferably 0.5 to 2.0 μm in terms of surface average roughness (Ra). If the thickness is less than 0.5 μm, air escape at the time of lamination deteriorates, and if it exceeds 2.0 μm, the design property at the time of printing is lowered, which is not preferable.

  As described above, various patterns can be printed on the surface of the (A) layer side of the laminated film of the present invention using printing ink. As a printing method, known methods such as gravure printing, flexographic printing, and screen printing can be employed. As a solvent for these printing inks, a common organic solvent such as ethyl acetate or methyl isobutyl ketone can be used.

  The laminated film thus obtained is used as a decorative sheet, such as furniture or furniture made of thermoplastic resin formed into a three-dimensional shape by a general method such as vacuum press molding or pressure press molding, It can also be attached and used by a general method.

  On the other hand, the laminated film of the present invention can be used as a laminated body by laminating with another thermoplastic resin sheet via the (A) layer side surface. Examples of the thermoplastic resin to be laminated include polystyrene resin, ABS resin, vinyl chloride resin, polyester resin, polyolefin resin and the like, and as a lamination method, (A) of the laminated film such as dry lamination and hot melt lamination. There are a method in which an adhesive layer is provided on the surface on the layer side, and a thermal laminating method in which the laminated film is laminated on the thermoplastic resin by thermal fusion while extruding the thermoplastic resin from a T-die. Since the laminated film of the present invention has high heat resistance of the layer (B), even when the outer surface comes into contact with a high-temperature metal roll during lamination with the thermoplastic resin, the design properties may be impaired. Absent. On the other hand, laminating the laminated film on the thermoplastic resin through the surface on the (B) layer side is because the (A) layer inferior in heat resistance comes in contact with a high-temperature metal roll, and thus the obtained laminate This is not preferable because the design property of the surface of the resin deteriorates.

Hereinafter, the present invention will be described specifically by way of examples.
In this invention, the resin shown below was used as a resin raw material for films.
PET resin Product name: PET3822 Made by NanYa, intrinsic viscosity 0.82
PEN resin Product name: Teonex TN8065S (homopolyethylene naphthalate) PBT resin made by Teijin Chemicals Ltd. Product name: Novaduran 5010R8M Polyester resin made by Mitsubishi Engineering Plastics Product name: PET-G6763 Product made by Eastman Chemical (glycol-modified PET resin)

  The resin raw materials were blended at a composition ratio shown in Table 1, and a laminated film composed of two layers (A) and (B) was obtained by a feed block method using two 40 mm single screw extruders. In forming the laminated film, the laminated film extruded from the T-die is used as a rubber roll (E) with the surface on the layer side embossed, and the surface on the (B) layer side is used as a mirror metal roll. The film was sandwiched between rolls and taken up so as to come into contact with the film and cooled with a cooling roll, and wound up to obtain laminated films of Examples 1 to 5 and Comparative Examples 1 to 5. In addition, the (A) layer side surface average roughness (Ra) of these laminated films was in the range of 0.7 to 1.2 μm, and the (B) layer side Ra was 0.1 μm or less.

About the film of each Example and a comparative example, the heat resistance required for extrusion strength processing of impact strength, yellowing by ultraviolet rays, and a thermoplastic resin was evaluated according to the following criteria.
(Impact strength)
Using the surface on the (B) layer side of the laminated film of each Example and Comparative Example as the impact surface, the DuPont impact strength was measured according to JIS K7124. The measurement results are shown in Table 2. In general, the PEN resin is inferior in impact resistance to the PET resin, but the laminated film of the example of the present invention has a practically satisfactory level of about 1 J or more.
(Yellowing due to ultraviolet rays)
Yellowing of the laminated film of each Example and Comparative Example by UV irradiation, (B) layer surface side exposed surface, UV tester (EYE SUPER UV TESTER SUV-W1 test temperature 40 ° C. UV irradiation intensity 100 mw / cm 2 exposure time 24 hours). Each sample after the exposure was evaluated by visual observation. A sample in which yellowing was not observed was evaluated as ◯, a slight yellowing was evaluated as Δ, and a marked yellowing was evaluated as ×. The evaluation results are shown in Table 2.

（耐熱性）
金属鏡面ロールを所定の温度に設定し、各実施例および比較例の積層フィルムの（Ｂ）層側の表面をロールに接触させた際に、積層フィルムの表面が軟化してロールに粘着（ベト付き）するかどうかを評価した。全く粘着しないものを○、僅かに粘着するものを△、粘着するものを×とした。評価結果を表３に示す。

(Heat-resistant)
When the metal mirror roll is set to a predetermined temperature and the surface of the (B) layer side of the laminated film of each Example and Comparative Example is brought into contact with the roll, the surface of the laminated film softens and adheres to the roll Applicable). A sample that did not adhere at all was indicated by ◯, a sample that adhered slightly, by Δ, and a sample that adhered by ×. The evaluation results are shown in Table 3.

  As described above, the laminated film of the present invention can be laminated as a decorative sheet on a sheet made of a thermoplastic resin such as an ABS resin by a method such as thermal lamination to obtain a laminated body with a decorated surface. This laminated body can be suitably used for interior materials such as indoor walls, bathroom panels, doors, furniture, etc., by performing U-cutting or V-cutting according to the application and bending it. On the other hand, the laminate can be formed into a three-dimensional shape by a general method such as vacuum press molding or pressure press molding using a three-dimensional mold, and can be suitably used for the same applications as described above. .

Claims (5)

(A) layer made of polyethylene terephthalate resin, and (B) layer having a thickness of 5 to 30 μm made of a mixture of polyethylene terephthalate resin and polyethylene naphthalate resin. (B) The ratio of polyethylene naphthalate resin in the layer is , polyethylene naphthalate ratio of (B) layer (mass%) × (B) layer thickness in value calculated by ([mu] m), der Ru product layer film less than 2000 beyond 400. The laminated film according to claim 1, wherein the surface on the layer side is embossed. The laminated film according to claim 2, wherein the embossed (A) layer side surface is printed. The laminated body which laminated | stacked the laminated | multilayer film of any one of Claims 1-3 with the thermoplastic resin on the surface by the side of (A) layer. The laminate according to claim 4 , wherein the thermoplastic resin is an ABS resin.