JP5115079B2 - Polyester film for molded transfer foil - Google Patents

Description

  The present invention relates to a polyester film for molded transfer foil, which is excellent in moldability, heat resistance, transfer foil productivity, and cost.

  The transfer foil is configured by sequentially laminating an easy adhesion layer, a release layer, a printing layer, an adhesive layer, and the like on one surface (transfer surface) of a film as a base material. As a transfer method of these transfer foils, a transfer device is used to transfer to a transfer object with a heating roll, or a so-called hot stamping method, or an adhesive layer is in contact with a mold resin of an injection molding machine or a blow molding machine. After setting the transfer material, injection molding or blowing of molding resin, transfer at the same time as molding, take out the molded product from the mold after cooling, generally known as so-called molding simultaneous transfer method represented by in-mold molding, etc. It has been. The in-mold molding method can be molded and transferred at the same time, so it is very useful for applying complex patterns, and is used for household appliances, automobile parts, kitchenware, cosmetic containers, toys and stationery. Widely used in plastic molded products.

  Conventionally, a biaxially stretched polyester film has been used as a film as a base material, but in recent years, a deep drawing followability that is difficult to develop with a conventional biaxially stretched polyester film has been demanded. For example, a biaxially stretched polyester film for molding processing (see Patent Document 1) excellent in deep drawing followability using a copolyester has been proposed.

However, recently, an insert label using an acrylic film as a base material (see Patent Document 2), which is difficult to develop in a biaxially stretched polyester film for molding, has a deeper deep drawing followability and low temperature. There is a need for the development of transfer foils on plastic molded products that require moldability. Although it is possible to use an acrylic film, the development with a polyester film is required from the viewpoint of cost.
JP-A-6-218893 JP-A-9-66537

  An object of the present invention is to eliminate the above-described problems of the prior art, and to provide a polyester film for molded transfer foil that is excellent in moldability, heat resistance, solvent resistance, productivity, and cost. .

The above-mentioned subject can be achieved by adopting the following means. That is, the polyester film for molded transfer foil of the present invention,
2 layers of polyester resin layer (A) / polyester resin layer (B), or 3 layers of polyester resin layer (A) / polyester resin layer (B) / polyester resin layer (A),
In the polyester resin layer (A), 90 mol% or more and 100 mol% or less in the total glycol-derived component of the polyester is 1,4-butanediol-derived component, and 90 mol% or more and 100 mol in the total dicarboxylic acid-derived component of the polyester. % Or less is a terephthalic acid-derived polyester,
In the polyester resin layer (B), 60 mol% to 99 mol% of the total glycol-derived component of the polyester is an ethylene glycol-derived component, and 1 mol% to 40 mol% of the total glycol-derived component is 1,4- A polyester film for molded transfer foil in which 90 to 100 mol% of the butanediol-derived component and the total dicarboxylic acid-derived component of the polyester is a terephthalic acid and / or naphthalenedicarboxylic acid-derived polyester,
The elongation at break of the polyester film for molded transfer foil at 120 ° C. is 400% or more,
And the stress at 400% elongation at 120 ° C. is 15 MPa or less,
The heat shrinkage rate when the film is heated at 100 ° C. for 30 minutes is −0.5 to 0.5%,
In at least the transfer surface side of the film surface of the molding transfer foil for polyester film state, and are gloss 100% or more,
In the film surface of at least the transfer side, center plane average roughness, characterized in der Rukoto than 40nm or less 18 nm, a polyester film, for forming and transferring foil.

  According to the present invention, it is possible to obtain a polyester film for molded transfer foil that is excellent in moldability, heat resistance, transfer foil productivity, and cost.

  Hereinafter, embodiments of the polyester film for molded transfer foil of the present invention will be described.

  The polyester used in the present invention is a polymer compound having an ester bond as the main bond chain of the main chain, and can be obtained by polycondensation of dicarboxylic acid and diol. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, diphenylcarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfoisophthalic acid, phthalic acid and other aromatic dicarboxylic acids, oxalic acid, and succinic acid. , Eicoic acid, adipic acid, sebacic acid, dimer acid, dodecanedioic acid, maleic acid, fumaric acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, trimellitic acid, and pyromellitic acid, etc. A polyfunctional acid etc. can be mentioned, It can also be set as a copolymer using two or more of these components. On the other hand, examples of the diol component include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol and triethylene glycol, aromatic glycols such as bisphenol A and bisphenol S, diethylene glycol, And polytetramethylene glycol and the like. A plurality of these components can be used to form a copolymer.

  In the polyester, there are various additives such as antioxidants, heat stabilizers, weathering stabilizers, UV absorbers, organic lubricants, organic and inorganic particles, pigments, dyes, fillers, antistatic agents and nuclei. An agent or the like may be added as long as the effects of the present invention are not impaired.

  It is important that the polyester film for molded transfer foil of the present invention has a breaking elongation at 120 ° C. of 400% or more. When the breaking elongation at 120 ° C. of the polyester film for molded transfer foil is less than 400%, the moldability is inferior, and film breakage tends to occur during molding, which is not preferable. More preferably, the breaking elongation at 120 ° C. of the film is 600% or more, and particularly preferably, the breaking elongation at 120 ° C. is 800% or more. Note that the upper limit of the elongation at break at 120 ° C. is not particularly limited, but in practice, it is considered difficult to set it to 2,000%.

  Furthermore, in the present invention, it is important that the stress at 400% elongation at 120 ° C. of the film is 15 MPa or less at the same time as controlling the breaking elongation at 120 ° C. of 400% or more as described above. When the stress at 400% elongation at 120 ° C. of the polyester film for molded transfer foil is greater than 15 MPa, it is not preferable because the moldability is inferior and the film does not sufficiently follow the mold. More preferably, the stress at 400% elongation at 120 ° C. of the film is 10 MPa or less. The lower limit value of the stress at 400% elongation at 120 ° C. is not particularly limited, but the lower limit value is considered to be 1 MPa in consideration of formability.

  In addition, in the present invention, at the same time, it is important that the thermal shrinkage rate when the polyester film for molded transfer foil of the present invention is heated at 100 ° C. for 30 minutes is −0.5 to 0.5%. When the thermal shrinkage rate of the polyester film for molded transfer foil is out of the above range, it is preferable because shrinkage occurs in the drying step when laminating the easy-adhesion layer, the release layer, the printing layer, and the adhesive layer, and wrinkles are likely to occur. Absent. More preferably, the thermal shrinkage when the film is heated at 100 ° C. for 30 minutes is −0.3 to 0.3. In the polyester film for molded transfer foil of the present invention, it is important that the direction in which the heat shrinkage rate is −0.5 to 0.5% is at least one direction in the film plane, and more preferably heat shrinkage. It is preferable that it is the orthogonal direction which exists in the same plane as this one direction whose rate is -0.5 to 0.5%. In addition, when the value of thermal contraction rate is a value of “−” (minus), it indicates that the film is stretched.

  In the polyester film for molded transfer foil of the present invention, when the elongation at break at 120 ° C. is 400% or more and the stress at 400% elongation at 120 ° C. is 15 MPa or less, the heat shrinkage rate when heated at 100 ° C. for 30 minutes is − Although the method of setting it as the polyester film for shaping | molding transfer foils made into 0.5 to 0.5% can be obtained, for example by the method described below, the polyester film for shaping | molding transfer foils of this invention is not limited to this.

  That is, the polyester film for molded transfer foil of the present invention has (1) two layers of polyester resin layer (A) / polyester resin layer (B), or polyester resin layer (A) / polyester resin layer (B) / polyester resin layer. (A) It consists of three layers, (2) The said polyester resin layer (A) is 90 mol% or more and 100 mol% or less in all the glycol origin components of polyester, 1, 4- butanediol origin component, polyester 90% by mole or more and 100% by mole or less of all dicarboxylic acid-derived components are polyesters that are terephthalic acid-derived components, (3) the thickness of one layer of the polyester resin layer (A) is 1 to 30 μm, (4) In the polyester resin layer (B), 60 mol% or more and 99 mol% or less of the total glycol-derived component of the polyester is ethylene. 1 mol% to 40 mol% of the components derived from the recall, 1,4-butanediol-derived components, 90 mol% to 100 mol% of all the dicarboxylic acid-derived components of the polyester are terephthalic acid and / or Or it is polyester which is a naphthalene dicarboxylic acid origin component is a preferable aspect as a polyester film for shaping | molding transfer foil of this invention.

  About said (2), the said polyester resin layer (A) is 90 mol% or more and 100 mol% or less in the component derived from all glycols of a polyester in a 1, 4- butanediol origin component, in all dicarboxylic acid origin components of polyester. It is preferable that 90 mol% or more and 100 mol% or less of the polyester is a terephthalic acid-derived component. The 1,4-butanediol-derived component of the polyester resin layer (A) is smaller than 90 mol% in the total dicarboxylic acid-derived component of the polyester, and the terephthalic acid-derived component is 90 in the total dicarboxylic acid-derived component of the polyester. When it is smaller than mol%, it is difficult to obtain a film having a thermal shrinkage ratio in at least one direction in the film plane of -0.5 to 0.5%, which is not preferable.

  About said (3), it is preferable that the thickness of 1 layer of the said polyester resin layer (A) is 1-20 micrometers. When the thickness of one layer of the polyester resin layer (A) is smaller than 1 μm, the solvent resistance is likely to be lowered, and it is difficult to obtain a film having a heat shrinkage rate within the above range, which is not preferable. Moreover, if the thickness of one layer of the polyester resin layer (A) is larger than 30 μm, the moldability, transparency, and gloss of the molded product after transfer are likely to deteriorate, and the stress at 400% elongation at 120 ° C. Is not preferable because it is difficult to obtain a film having a thickness of 15 MPa or less.

  About said (4), the said polyester resin layer (B) is 60 mol% or more and 99 mol% or less in all the glycol origin components of polyester from ethylene glycol origin components and 1 mol% or more and 40 mol% in all glycol origin components. It is preferable that the following is a polyester in which 90 mol% or more and 100 mol% or less of the 1,4-butanediol-derived component and the total dicarboxylic acid-derived component of the polyester is a terephthalic acid and / or naphthalenedicarboxylic acid-derived component. If the glycol component other than the above and / or the content is outside the above range, the moldability and productivity are likely to be lowered, and the elongation at break at 120 ° C becomes difficult to be 400% or more, and at 120 ° C. Since it becomes difficult for the stress at 400% elongation to be 15 MPa or less, it is not preferable.

  Moreover, as a manufacturing method of the polyester film for shaping | molding transfer foil of this invention, (5) It is a manufacturing method which extrudes the heat-melted resin from T-die, adheres to the cooling roll heated at 40-90 degreeC, and solidifies by cooling. Is preferred. When the temperature of the cooling roll is lower than 40 ° C., the adhesion to the cooling roll is lowered, and as a result, the productivity is easily lowered, and the thermal shrinkage rate in at least one direction in the film plane is −0. It is not preferable because it is difficult to obtain a film controlled to 5 to 0.5%. On the other hand, if the temperature of the cooling roll is higher than 90 ° C., the gloss of the molded product after transfer tends to decrease, and a film having a stress at 400% elongation at 120 ° C. of 15 MPa or less is difficult to obtain. It is not preferable. Moreover, it is preferable that the centerline average roughness of a cooling roll is 0.1-5 micrometers from a viewpoint of transparency, the glossiness of the molded article after transcription | transfer, and productivity. Furthermore, as a method for improving the adhesion to the cooling roll, from the viewpoint of transparency, gloss of the molded product after transfer, and productivity, an electrostatic application method using a needle-like edge pinning device at both ends of the sheet and an air chamber It is preferable to use the method in combination.

Polyester film for forming and transferring foil of the present invention, from the viewpoint of molding of the glossiness after transfer, the film surface of at least the transfer surface, but glossiness is 100% or more. When the glossiness is less than 100% on the film surface on the transfer surface side of the polyester film for molded transfer foil, the surface of the transferred material after transfer is not smooth, and as a result, the glossiness of the surface of the molded product tends to be lowered. that Do not. Also, good Mashiku, in the film surface of at least the transfer surface side, and a glossiness of 110% or more, particularly preferably, in the film surface of at least the transfer surface glossiness of 120% or more. The upper limit value of the glossiness is not particularly limited, but it is considered difficult to set it to 200% or more in practice.

  The polyester film for molded transfer foil of the present invention preferably has a center plane average roughness of 40 nm or less at least on the film surface on the transfer surface side, from the viewpoint of gloss of the molded product after transfer. More preferably, it is 30 nm or less. The lower limit value of the center plane average roughness is not particularly limited, but it is considered that it is practically difficult to set it to 0.1 nm or less.

  In the polyester film for molded transfer foil of the present invention, the method of setting the center surface average roughness to 40 nm or less is to extrude a heat-melted resin from a T die and heat it to 40 to 90 ° C. when producing the film of the present invention. It is preferable to make it the manufacturing method which makes it closely_contact | adhere to the cooling roll which carried out and solidifies by cooling. If the temperature of the cooling roll is higher than 90 ° C., it is difficult to obtain a film having a center plane average roughness of 40 nm or less. In addition, when using the manufacturing method which adheres to the cooling roll heated at 40-90 degreeC, and solidifies by cooling, preferable polyester resin layer (A) / polyester resin layer (as above-mentioned as a polyester film for shaping | molding transfer foils of this invention ( When using the polyester film which consists of two layers of B), it is preferable to make the surface side of a polyester resin layer (A) contact | adhere to a cooling roll.

  The polyester film for molded transfer foil of the present invention preferably has a haze of 0.1 to 30% from the viewpoint of transfer foil productivity. Moreover, Preferably it is 0.1 to 20%, More preferably, it is 0.1 to 10%.

  In the polyester film for molded transfer foil according to the present invention, the method for adjusting the haze to 0.1 to 30% is that in the manufacturing method, a heat-melted resin is extruded from a T-die and adhered to a cooling roll heated to 40 to 90 ° C. It is preferable to use a production method that cools and solidifies. When the temperature of the cooling roll is higher than 90 ° C., it is difficult to obtain a film having a haze of 0.1 to 30%, which is not preferable.

  The polyester film for molded transfer foil of the present invention preferably has a plane orientation coefficient of 0 to 0.05 from the viewpoint of moldability. In the polyester film for molded transfer foil of the present invention, the method for setting the plane orientation coefficient to 0 to 0.05 is preferably such that the polyester film for molded transfer foil of the present invention is an unstretched film. That is, it is preferable not to provide a stretching process in the longitudinal direction and the width direction during film formation. In a normal film manufacturing method, even a non-stretched film is drafted during film formation, and the film may be slightly oriented in the machine (longitudinal) direction. In order to obtain 05, it is important to suppress the orientation even in the case of non-stretching.

  The polyester film for molded transfer foil of the present invention preferably has a thickness of 25 to 300 μm. If it is less than 25 μm, the moldability and productivity are likely to be lowered, which is not preferable. Similarly, when the thickness exceeds 300 μm, the moldability and productivity are likely to be lowered, which is not preferable.

  Various particles can be added to the polyester film for molded transfer foil of the present invention depending on the purpose and application. The particles to be added are not particularly limited as long as they are inert to the polyester resin, and examples thereof include inorganic particles, organic particles, crosslinked polymer particles, and internal particles generated in the polymerization system. Two or more kinds of these particles may be added. The amount of such particles added is preferably 0.01 to 10% by weight, more preferably 0.05 to 3% by weight, based on the total weight of the metal film-covering polyester film of the present invention.

  The type of inorganic particles is not particularly limited, but various carbonates such as calcium carbonate, magnesium carbonate and barium carbonate, various sulfates such as calcium sulfate and barium sulfate, various composite oxides such as kaolin and talc, lithium phosphate Various phosphates such as calcium phosphate and magnesium phosphate, various oxides such as aluminum oxide, silicon oxide, titanium oxide and zirconium oxide, and various salts such as lithium fluoride can be used.

  As the organic particles, calcium oxalate, terephthalate such as calcium, barium, zinc, manganese, magnesium, etc. are used.

  Examples of the crosslinked polymer particles include homopolymers or copolymers of vinyl monomers such as divinylbenzene, styrene, acrylic acid, and methacrylic acid. In addition, organic fine particles such as polytetrafluoroethylene, benzoguanamine resin, thermosetting epoxy resin, unsaturated polyester resin, thermosetting urea resin, and thermosetting phenol resin are also preferably used.

  The internal particles produced in the polyester polymerization system are produced by a known method in which an alkali metal compound, an alkaline earth metal compound or the like is added to the polyester reaction system, and a phosphorus compound is also added to the polymerization system. Particles.

  Various additives can be contained in the polyester film for molded transfer foil of the present invention. That is, as components other than the polyester resin, known additives as necessary, for example, flame retardants, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, plasticizers, tackifiers, fatty acid esters, An appropriate amount of an organic lubricant such as wax or an antifoaming agent such as polysiloxane can be blended.

  A known polymer can be added to the polyester constituting the polyester film for molded transfer foil of the present invention, if necessary. For example, polyolefins such as polyethylene and polypropylene, acrylics such as polyacrylate and polymethyl methacrylate, and polymers such as polycarbonate can be blended in appropriate amounts.

  An easy-adhesion layer formed of a coating layer containing a polyester resin can be provided on the transfer surface side of the polyester film for molded transfer foil of the present invention. The film for in-mold molding has a function of laminating an easy-adhesion layer, a release layer, a printing layer, etc. sequentially on the transfer surface side of the polyester film for molded transfer foil in that process. Laminating the easy-adhesion layer in the process of forming the polyester film for foil is a preferable embodiment from the viewpoint of manufacturing cost and processing time because the step of providing the easy-adhesion layer in the processing process can be omitted.

  Examples of methods for providing an easy-adhesion layer on the transfer surface of a polyester film for molded transfer foil include a method of kneading into an outer layer as a multilayer structure, a method of in-line coating during film formation, a method of offline coating after film formation, etc. There is no particular limitation. Various coating methods such as a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a die coating method, and a spray coating method can be preferably used as the coating method for the coating liquid, but are not limited thereto. It is not something.

  10-2000 nm is preferable and, as for the thickness of an easily bonding layer, More preferably, it is 50-1000 nm. If the thickness of the easy-adhesion layer is too thin, adhesion to the release layer and solvent resistance may be insufficient, and if it is too thick, the slip resistance and blocking resistance when used as a film roll will deteriorate. There is a case.

  Moreover, it is preferable that an easily bonding layer contains a polyester resin. When a polyester resin is used for the easy-adhesion layer, it has a high affinity with the polyester film for molded transfer foil that is a base material, so that interfacial peeling and scraping hardly occur, and in the case of aqueous coating, the coating appearance is improved. Moreover, it is preferable that it is a polyester resin also from a viewpoint of manufacturing cost or the adhesive force with a mold release layer.

  The polyester contained in the easy-adhesion layer is preferably a copolymerized polyester containing diethylene glycol as a copolymerization component. By using this component as a copolymerization component, it is possible to improve the solvent resistance of the easy-adhesion layer particularly to alcohol, and it is possible to improve the affinity with the polyester film for molded transfer foil that is a substrate. As other copolymerization components, known dicarboxylic acids and diols can be used, and examples thereof include the above-mentioned dicarboxylic acids and diols, which are formed on the transfer surface of the polyester film for molded transfer foil of the present invention. The polyester contained in the easy-adhesion layer is not limited thereto. Moreover, the compound containing an above described sulfonate group and the compound containing a carboxylate group can also be included as a copolymerization component. The range of the preferable glass transition point of this copolyester is 0-60 degreeC, More preferably, it is 10-45 degreeC.

  The content of the copolymerized polyester containing diethylene glycol as a copolymerization component is preferably 10 to 60% by weight, more preferably 20 to 50% by weight, based on the total amount of resins forming the easy-adhesion layer. If the content is too small, the solvent resistance and the adhesive strength with the polyester film for molded transfer foil as the substrate may be inferior, and if it is too large, the blocking resistance may be inferior when used as a film roll.

  The resin other than the copolyester having a copolymer component of diethylene glycol that forms the easy-adhesion layer is not particularly limited as long as the effects of the present invention are not impaired, but other polyester resins, acrylic resins, A urethane resin, an epoxy resin, a silicone resin, a urea resin, a phenol resin, and the like can be exemplified. Among them, other polyester resins can be preferably exemplified.

  Further, in the easy-adhesion layer in the present invention, for example, an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, a pigment, and a dye are within the range where the effects of the present invention are not impaired. Organic or inorganic fine particles, fillers, antistatic agents, nucleating agents, and the like may be blended.

  The polyester film for molded transfer foil of the present invention can be improved in coating properties, printability and the like as necessary by performing a surface treatment such as a corona discharge treatment. Various coatings may be applied, and the type, coating method, and thickness of the coating compound are not particularly limited as long as the effects of the present invention are not impaired. Furthermore, it can be used after being subjected to molding processing such as embossing, printing, or the like, if necessary.

  The transfer foil for in-mold molding using the polyester film for molded transfer foil of the present invention may have any form as long as it is a transfer foil used for in-mold molding, but for the molded transfer foil of the present invention which is a substrate. Transfer that has a release layer, protective layer, printing layer, vapor deposition layer, adhesive layer, etc. on the transfer surface of the polyester film, and is suitable for decorating plastic parts such as mobile phones, automobile parts, and home appliances. A foil is preferred. In this case, it is more preferable that the release layer is formed of a melamine resin component and the protective layer is formed of an acrylic resin component having hard coat properties.

  The polyester film for molded transfer foil of the present invention can be obtained by a melt extrusion method such as a T-die method or an inflation method. For example, when a film is obtained by the T-die method, it is an important condition that the extruded film is rapidly cooled and solidified by cooling.

  Next, although the manufacturing method of the polyester film for shaping | molding transfer foil of this invention is demonstrated, this invention is not limited to this.

The polyester film for molded transfer foil of the present invention may be prepared by, for example, drying the polyester A constituting the polyester resin layer (A) and the polyester B constituting the polyester resin layer (B) as necessary, followed by known melt extrusion. Supply to the machine. In addition, as mentioned above, as polyester A which comprises a polyester resin layer (A), 90 mol% or more and 100 mol% or less in the component derived from all the glycols of a polyester are 1, 4- butanediol origin components, all the dicarboxylic acids of polyester. polyester 100 mol% 90 mol% or more acid-derived component or less is derived from terephthalic acid component, Ru der. Furthermore, as mentioned above, as the polyester B constituting the polyester resin layer (B), 60 mol% or more and 99 mol% or less in the total glycol-derived component of the polyester is an ethylene glycol-derived component, in the total glycol-derived component. 1 to 40 mol% of the polyester is a component derived from 1,4-butanediol, and 90 to 100 mol% of the total dicarboxylic acid-derived component of the polyester is a component derived from terephthalic acid and / or naphthalenedicarboxylic acid. Oh Ru.

  The extruder may be a single screw melt extruder or a twin screw melt extruder provided with a vent port. The supplied resin is melted at a temperature of the melting point of each polyester + 20-30 ° C. and then passed through a leaf disk filter having a filtration accuracy of 30 μm. Next, three layers of polyester resin layer (B) / polyester resin layer (A) / polyester resin layer (B) or two-layer pinole tube of polyester resin layer (B) / polyester resin layer (A) are passed through and slitted. Into a T-die die and extruded into a sheet.

  Adhering to a cooling roll adjusted to a surface temperature of 40 to 90 ° C by electrostatic application method using a needle-like edge pinning device, air nozzle, air chamber method, suction chamber method, etc. at both ends of the extruded sheet The polyester film for molded transfer foil can be obtained by cooling and solidifying from a molten state. As described above, in the case of a two-layer configuration of polyester resin layer (A) / polyester resin layer (B), it is preferable that the polyester resin layer (A) side is in close contact with the cooling roll.

  The cooling roll may be a mirror surface or a satin finish, but a satin finish having a center line average roughness of 0.1 to 5 μm is preferable from the viewpoint of adhesion of the film to the cooling roll and adhesiveness. When using satin, the adhesion to the cooling roll tends to be insufficient, and it becomes a film with poor transparency, so it is preferable to use another adhesion method, particularly in a continuous air flow at a temperature of 0 to 40 ° C. The method of making it adhere | attach is preferable.

  The obtained film is a substantially non-oriented unstretched film having a plane orientation coefficient fn of 0.00 to 0.05. In order to set the thermal shrinkage rate in at least one direction in the film plane when the stress at 400% elongation at 120 ° C. is 15 MPa or less and heated at 100 ° C. for 30 minutes to −0.5 to 0.5%, The roll temperature is preferably 40-90 ° C. When the temperature of the cooling roll exceeds 90 ° C., the stress at 400% elongation at 120 ° C. tends to be greater than 15 MPa, and the film tends to stick to the cast drum, resulting in poor productivity. Moreover, when the temperature of a cooling roll exceeds 90 degreeC, since a film whitens and transparency may be inferior or the moldability of a film may be inferior, it is unpreferable. Conversely, if the temperature of the cooling roll is less than 40 ° C, the heat shrinkage rate in at least one direction in the film plane when heated at 100 ° C for 30 minutes can be controlled to -0.5 to 0.5%. And the solvent resistance and heat resistance are inferior.

EXAMPLES Hereinafter, although this invention is demonstrated along an Example, this invention is not restrict | limited by these Examples. Various characteristics were measured and evaluated by the following methods.
(1) Total thickness Ten points were measured at equal intervals in the width direction of the film using a Mitsutoyo Digimatic Micrometer MDC-25S, and the average value was obtained as a measurement result.
(2) Lamination thickness A sample of the polyester film for molded transfer foil of the present invention was sampled to 10 mm x 5 mm, and cut in the cross-sectional direction in ice using a microtome. Using a transmission electron microscope HU-12 manufactured by Hitachi, Ltd., the cross section of the cut sample was magnified 300 times and observed, and the lamination thickness was calculated.
(3) Breaking elongation at 120 ° C. and stress at 400% elongation at 120 ° C. The polyester film for molded transfer foil of the present invention was subjected to ASTM D-882 using an orientec tensile tester UCT-100. The measurement was performed in a 120 ° C. atmosphere. The pulling direction was two directions, ie, the film forming direction and the width direction of the polyester film for molded transfer foil, the width of the sample was 10 mm, the initial length was 20 mm, and the pulling speed was 200 mm / min.
(4) Heat shrinkage rate The polyester film for molded transfer foil of the present invention was cut into a size of 100 mm × 10 mm in two directions, ie, the film forming direction and the width direction of the molded transfer foil polyester film, and the load was uniformly constant (3 g). The length was measured with an automatic length measuring device manufactured by Technonez Corporation. Subsequently, it was placed in an oven at 100 ° C. for 30 minutes, and after the heat treatment, the post-treatment length was measured again with an automatic length measuring device, and the heat shrinkage rate was obtained from the following formula.

Thermal shrinkage (%) = (original length-post-treatment length) / original length x 100
(5) Glossiness The transfer surface of the polyester film for molded transfer foil of the present invention was measured according to JIS Z 8741-1997, using a digital variable angle glossiness meter UGV-4D manufactured by Suga Test Instruments Co., Ltd. The incident angle was 60 ° and the light receiving angle was 60 °.
(6) Center surface average roughness The transfer surface of the polyester film for molded transfer foil of the present invention was measured by the stylus method under the following conditions using a high-precision fine shape measuring machine SUREFCORDET 4000A manufactured by Kosaka Laboratory. Went. The center plane average roughness is a difference between the roughness curved surface and the height direction of the center plane of the roughness curved surface, and represents an average value of absolute values thereof.
・ Tip tip R 2 (μmR)
・ Measuring force 100 (μN)
-X measurement length 1.0 (mm)
・ X feed speed 0.1 (mm / s)
-X return speed 0.2 (mm / s)
・ Y feed pitch 5 (μm)
・ Z magnification 20000 (times)
・ Number of Y lines 81 (books)
・ Low-frequency cutoff 0.25 (mm)
・ High frequency cutoff R + W
-Phase characteristics 2CR normal type (7) haze The polyester film for molded transfer foil of the present invention was measured according to JIS K 7105-2004 using a direct reading haze computer HGM-20P manufactured by Suga Test Instruments Co., Ltd.
(8) Plane orientation coefficient It measured using the transfer surface of the polyester film for shaping | molding transfer foils of this invention. The apparatus uses an Abbe refractometer NAR-4T (manufactured by Atago Co., Ltd.), a sodium D line (wavelength 589 nm) as a light source, and methylene iodide as a mount solution, and refractive indexes in the MD, TD, and thickness directions. (Respectively nx, ny, nz) were obtained, and the plane orientation coefficient was obtained from the following formula.

Plane distribution coefficient = (nx + ny) / 2−nz
(9) Solvent resistance of base film After measuring the haze of the polyester film for molded transfer foil of the present invention, on the transfer surface of the polyester film for molded transfer foil of the present invention, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene 3 ml of each was dropped and allowed to stand for 6 hours, and then the solvent was wiped clean and the film haze was measured by the method described above. And the change of the haze before and behind solvent dripping was measured, and it determined in accordance with the following evaluation criteria. ○ and △ are acceptable levels. Here, when the polyester film for molded transfer foil of the present invention is a two-layer laminate of polyester resin layer (A) / polyester resin layer (B), a test was conducted by dropping a solvent on the polyester resin layer (A) side. Carried out.
○: Δhaze (= haze value after test−haze value before test) ≦ 5% for all solvents.
Δ: When it is not ○ or ×.
X: 10% <Δhaze (= haze value after test−haze value before test) with respect to any solvent.
(10) Coating suitability, moldability, gloss of molded product surface,
A release layer was formed by a gravure coating method using an acrylic resin on the transfer surface side of the polyester film for molded transfer foil of the present invention and dried at 100 ° C. On top of that, a solid pattern of metallic color (containing 20% aluminum pigment) and a character pattern of black (containing 15% carbon black) were formed by gravure printing as a pattern layer, and dried at 80 ° C. . Next, the substrate was washed with warm water at 40 ° C. and dried, and finally an acrylic resin adhesive layer was formed on the pattern layer by a gravure coating method and dried at 80 ° C. to obtain a transfer foil.

The obtained transfer foil is vacuum-formed using a cylindrical cup concave mold with a diameter of 50 mm and a depth of 50 mm, with a fixed temperature in the mold at a mold temperature of 120 ° C. and an adhesive layer inside. After that, mold clamping was performed, and thereafter, simultaneous molding and transfer processing was performed under an injection pressure condition of 25 MPa using an acrylic resin as a molding resin.
(A) Suitability of coating The obtained transfer foil was visually observed and judged according to the following criteria in terms of defects, turbidity, wrinkles and the like.
○: Very clean and free from defects, wrinkles, turbidity.
(Triangle | delta): Although it is comparatively favorable, a slight turbidity, a very slight wrinkle, etc. are recognized.
X: Poor quality, defects or turbidity, wrinkles are observed.
(B) Formability With respect to the transfer foil after vacuum forming, the state of the transfer foil formed with the sharpest corners was visually observed and judged according to the following criteria.
A: The corners were sharply formed and the thickness after forming was uniform.
Δ: Slightly rounded corners and slightly non-uniform thickness after molding.
X: The thickness after molding was uneven, and wrinkles and tearing occurred.
(C) Gloss on the surface of molded product The obtained molded product was measured according to JIS Z 8741-1997 using a digital variable angle gloss meter UGV-4D manufactured by Suga Test Instruments Co., Ltd. The incident angle was 60 ° and the light receiving angle was 60 °. When the surface glossiness of the molded product was GF and the surface glossiness of the standard metal sample was GM, the following judgment was followed.
○: GF ≧ GM
Δ: GM-20 ≦ GF <GM
X: GF <GM-20.
[Polybutylene terephthalate A (PBT-A)]
“Toraycon” (registered trademark) 1200S polybutylene terephthalate (melting point: 224 ° C., intrinsic viscosity: 1.23 dl / g) manufactured by Toray Industries, Inc. was used.
[Polybutylene terephthalate B (PBT-B)]
6% by weight of silicon dioxide (“Silysia 445” manufactured by Fuji Silysia Chemical Co., Ltd., average particle size of 2.5 μm) is made of Toray Industries, Inc. “Trecon” (registered trademark) 1200S polybutylene terephthalate (melting point 224 ° C., intrinsic viscosity) 1.23 dl / g) and the resulting mixture was fed to a vented twin screw extruder (L / D = 35) set at 250 ° C. The molten resin melted in the extruder is supplied to the die, extruded from a circular hole having a diameter of 5 mm, and immediately cooled with 10 ° C. cooling water to cut the gut-shaped resin obtained at intervals of 4 mm. Of polybutylene terephthalate (melting point: 226 ° C., intrinsic viscosity: 1.19 dl / g) was obtained.
[Polyethylene terephthalate A (PET-A)]
To a mixture of 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol, 0.09% by weight of magnesium acetate and 0.03 part by weight of antimony trioxide are added to the amount of dimethyl terephthalate, and the temperature is raised by a conventional method. Then, a transesterification reaction was performed. Subsequently, 0.020 part by weight of 85% aqueous solution of phosphoric acid is added to the transesterification reaction product with respect to the amount of dimethyl terephthalate, and then transferred to a polycondensation reaction tank. Subsequently, the reaction system was gradually depressurized while being heated, and a polycondensation reaction was performed at 290 ° C. under a reduced pressure of 1 mmHg by a conventional method to obtain a polyethylene terephthalate resin having a melting point of 257 ° C. and an intrinsic viscosity of 0.71 dl / g. .
[Isophthalic acid copolymerized polyethylene terephthalate B (PET-B)]
Except that the dicarboxylic acid component was 82.5 mol% dimethyl terephthalate and 17.5 mol% dimethyl isophthalate, 17.5 mol% copolymerized polyethylene terephthalate (melting point 223 ° C., 223 ° C. An intrinsic viscosity of 0.58 dl / g) was obtained.
Example 1
As polyester of the polyester resin layer (A), a mixture of PBT-A (96% by weight) and PBT-B (4% by weight) was used, dried at 150 ° C. for 4 hours under reduced pressure, and then set to an extrusion temperature of 255 ° C. The mixture of PBT-A (8 wt%) and PET-A (92 wt%) was used as the polyester of the polyester resin layer (B) in a single screw extruder (L / D = 36) at 150 ° C. for 4 hours. After drying under reduced pressure, each was administered to a single screw extruder (L / D = 36) set at an extrusion temperature of 280 ° C., and polyester resin layer (A) / polyester resin layer (B) / polyester resin layer (A) Through a three-layer pinole, and led to a T die die with a slit gap of 0.8 mm set at 280 ° C., extruded into a film, and electrostatically applied using needle-like edge pinning devices at both ends of the extruded sheet In combination with an air chamber method and the center line average roughness of the temperature 60 ° C. is cooled and solidified by close contact with 1μm satin cooling roll, to obtain a molding transfer foil for polyester film having a thickness of 75 [mu] m.

The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, it showed excellent characteristics in moldability, heat resistance, and transfer foil productivity.
(Examples 2-3)
A polyester film for molded transfer foil of the present invention was obtained in the same manner as in Example 1 except that the polymer used in the polyester film for molded transfer foil of the present invention was changed as shown in Table 1.

The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, although some characteristics were slightly inferior, others exhibited excellent characteristics.
Example 4
The molding of the present invention was carried out in the same manner as in Example 1 except that the film lamination structure of the polyester film for molded transfer foil of the present invention and the polymer used were changed as shown in Table 1 and the air chamber system was not used. A polyester film for transfer foil was obtained.

The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, although some characteristics were slightly inferior, others exhibited excellent characteristics.
(Comparative Examples 1-3)
The film transfer constitution of the polyester film for molded transfer foil of the present invention, the polymer to be used are changed as shown in Table 1, and the molded transfer foil of the present invention is produced in the same manner as in Example 1 except that the air chamber method is not used. A polyester film was obtained.

The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, some characteristics were inferior.
(Comparative Examples 4-5)
A polyester film for molded transfer foil of the present invention was obtained in the same manner as in Example 1 except that the film lamination configuration of the polyester film for molded transfer foil of the present invention and the polymer used were changed as shown in Table 1.

The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, some characteristics were inferior.
(Comparative Example 6)
As polyester B constituting the polyester resin layer (B), PET-B was used, and after drying under reduced pressure at 150 ° C. for 4 hours, it was administered to a single screw extruder set to an extrusion temperature of 260 ° C. and set to 260 ° C. The film was led to a T die die having a slit gap of 0.8 mm, extruded into a film shape, wound around a mirror surface metal drum kept at 25 ° C. while being electrostatically applied, and cooled and solidified to obtain an unstretched film. Next, this unstretched film is stretched 3.2 times at 90 ° C. in the longitudinal direction, stretched 3.2 times at 115 ° C. in the width direction, heat treated at 200 ° C., and biaxially stretched polyester having a thickness of 20 μm. A film was obtained.

  The polyester film for molded transfer foil of the present invention obtained in this way, the transfer foil using the polyester film for molded transfer foil of the present invention, and the molded product that has been subjected to molding simultaneous transfer processing using the transfer foil are as follows: As shown in Table 1, some characteristics were inferior.

  The present invention can provide a polyester film for molded transfer foil that is excellent in moldability, heat resistance, transfer foil productivity, and cost.

Claims (4)

2 layers of polyester resin layer (A) / polyester resin layer (B), or 3 layers of polyester resin layer (A) / polyester resin layer (B) / polyester resin layer (A),
In the polyester resin layer (A), 90 mol% or more and 100 mol% or less in the total glycol-derived component of the polyester is 1,4-butanediol-derived component, and 90 mol% or more and 100 mol in the total dicarboxylic acid-derived component of the polyester. % Or less is a terephthalic acid-derived polyester,
In the polyester resin layer (B), 60 mol% to 99 mol% of the total glycol-derived component of the polyester is an ethylene glycol-derived component, and 1 mol% to 40 mol% of the total glycol-derived component is 1,4- A polyester film for molded transfer foil in which 90 to 100 mol% of the butanediol-derived component and the total dicarboxylic acid-derived component of the polyester is a terephthalic acid and / or naphthalenedicarboxylic acid-derived polyester,
The elongation at break of the polyester film for molded transfer foil at 120 ° C. is 400% or more,
And the stress at 400% elongation at 120 ° C. is 15 MPa or less,
The heat shrinkage rate when the film is heated at 100 ° C. for 30 minutes is −0.5 to 0.5%,
In at least the transfer surface side of the film surface of the molding transfer foil for polyester film state, and are gloss 100% or more,
In the film surface of at least the transfer side, center plane average roughness, characterized in der Rukoto than 40nm or less 18 nm, the polyester film for forming and transferring foil. 2. The polyester film for molded transfer foil according to claim 1 , wherein the haze of the film is 0.1 to 30%. The polyester film for molded transfer foil according to claim 1 or 2 , wherein the film has a plane orientation coefficient of 0 to 0.05. Molded transfer foil comprising the polyester film for molded transfer foil according to any one of claims 1 to 3 .