JP2011173298A - Laminated film with high mold releasability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold releasable laminated film which is excellent in mold releasability, printability, environmental load when it is discarded, and moldability such as followability to a film to be an adherend and a body to be transferred when it is molded. <P>SOLUTION: The laminated film has a polyolefin based resin layer on at least one side of a polyester film. The polyolefin based resin layer contains a polyolefin resin having methyl pentene units. In the laminated film, a change in haze when the film is stretched by 100% at 100°C is 0-10%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laminated film having a polyolefin resin layer on at least one side of a polyester film, the polyolefin resin layer relates to a laminated film containing a polyolefin resin having a methylpentene unit. Relates to a laminated film excellent in releasability and moldability.

  Films having releasability are widely used in various surface protective films, transfer foils, and the like. Surface protective film is used by sticking it on adherends such as resin parts, metal products, glass products, etc. mainly for building materials and optical applications, to prevent scratches or foreign matter from entering during transportation, storage or processing. Playing a role. These surface protective films are required to have an appropriate adhesion to the adherend while being used as a protective film, and an appropriate releasability so that the protective film can be easily removed when the product is used. In the case of protecting a molded body having a three-dimensional shape, the surface protection film is required to have moldability in addition to adhesion and releasability.

  In addition, the transfer foil is configured by sequentially laminating an easy adhesion layer, a release layer, a clear 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. Generally known is the so-called simultaneous molding transfer method represented by in-mold molding, in which molding material is injected or blown, transferred at the same time as molding, transferred after molding, and the molded product is taken out from the mold after cooling. 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. Plastic used in household appliances, automobile parts, kitchen utensils, cosmetic containers, toys and stationery Widely used in molded products.

  As described above, as a method for imparting releasability to a film and using it for various surface protection films, transfer foils, etc., a resin having releasability is formed into a film, and extrusion laminated with a film as a substrate. Examples thereof include a method, a method of forming a release layer by dissolving a release agent in a solvent, coating the film as a base material, and drying. Among these, in extrusion lamination, it is difficult to form a thin film on a base material, and the cost reduction effect is low. There was also a problem in adhesion to the substrate.

  Lamination by coating is an effective formulation in terms of thinning the release layer, and various methods have been proposed. Examples of the method using a solvent-based coating agent include a method of laminating a vinyl group-containing polydimethylsiloxane (Patent Document 1), a method of laminating a fluorine compound (Patent Document 2), and a method of laminating a silicone resin (Patent Document). 3), a method of laminating a polyolefin resin having a special composition (Patent Document 4), and a method of laminating an acrylic resin (Patent Document 5) are disclosed. On the other hand, as a method of laminating a polymethylpentene resin, Patent Document 6 proposes improvement of solubility of polymethylpentene resin in a solvent, and Patent Document 7 proposes improvement of adhesion to a substrate. .

JP 2002-182037 A JP 2007-002066 A JP 2005-125656 A JP 2009-101680 A International Publication WO2007-055225 Pamphlet JP 2006-131723 A JP 2006-130796 A

  The resin layer described in Patent Document 1 has a problem that requires treatment at a high temperature for lamination and curing, and is a surface protective film for adherends, transferred objects, and films that are not heat resistant. And there was a problem that application as a transfer foil was difficult.

  In addition, the resin described in Patent Document 2 is expensive and has a problem that it is difficult to burn in the waste incineration treatment after use and generates toxic gas. The resin layer described in Patent Document 3 has a problem of poor adhesion to the base material and insufficient releasability and the like. In Patent Document 4, there is a problem that followability is insufficient for transfer to a member having a large aperture ratio or a member having a complicated shape. In patent document 5, since the solvent resistance of the release layer is insufficient, depending on the type of the solvent contained in the clear layer or the print layer, the planarity of the release layer is deteriorated, and printing defects are likely to occur. was there.

  In Patent Documents 6 and 7, the polymethylpentene resin needs to be molded at a high temperature in order to follow the adherend and the transfer target, and at a temperature at which the adherend, the transfer target, and the film can withstand, The followability to a member with a large aperture ratio or a member with a complicated shape was insufficient.

  In view of these problems, the present invention is a laminate having a release layer that is excellent in mold release, printability, environmental load at the time of disposal, and also excellent in moldability such as followability to a substrate during molding. It is intended to provide a film.

The present invention employs the following means in order to solve such problems. 1) A laminated film having a polyolefin resin layer on at least one side of a polyester film,
The polyolefin resin layer includes a polyolefin resin having a methylpentene unit,
A laminated film having a haze change of 0 to 10% at 100% elongation at 100 ° C.
2) The laminated film according to 1) above, wherein the polyolefin resin layer has a Vicat softening temperature of 30 to 175 ° C.
3) The laminated film as described in 1) or 2) above, wherein the polyolefin-based resin layer has a thickness of 0.1 to 50 µm.
4) The laminated film according to any one of 1) to 3), wherein the elongation at break at 100 ° C is 150% or more, and the stress at 100% elongation at 100 ° C is in the range of 0.5 to 60 MPa.
5) The polyester film is a laminated polyester film composed of at least two layers of a highly crystalline polyester layer and another polyester layer,
The highly crystalline polyester layer has a crystallinity parameter ΔTcg of 35 ° C. or less,
The laminated film according to any one of 1) to 4) above, wherein a polyolefin-based resin layer, a highly crystalline polyester layer, and another polyester layer are laminated in this order.

  According to the present invention, it is possible to obtain a laminated film that is excellent in releasability, printability, environmental load at the time of disposal, and also excellent in moldability such as adherend and followability to a transferred object during molding. it can. More specifically, as for releasability, since it is excellent in releasability from the transfer target, peeling marks are hardly generated in the releasable process. Regarding printability, various printing inks can be used because of excellent solvent resistance against solvents contained in the printing ink, particularly ethyl acetate and methyl ethyl ketone. In addition, since polyvinyl chloride resin generally used as a release layer contains a halogen element, it has a large environmental load at the time of disposal. However, a polyolefin resin layer which is a release layer of the laminated film of the present invention is a halogen element. Since it has the same releasability as that of the polyvinyl chloride resin even if it is not used, there is an advantage that the environmental load is small. The laminated film of the present invention is excellent in moldability such as deep drawability and followability to the surface shape of a transfer object, and therefore, in-mold transfer foil used by printing and molding, automobile interior / exterior parts, bathroom panels, home appliances It is suitably used as a transfer foil for transferring a printing process for product parts, packaging containers, and the like.

The present invention has a release layer that is excellent in the above-mentioned problems, that is, releasability, printability, environmental load at the time of disposal, and also excellent in followability to a film that becomes an adherend and a transfer target during molding. The film is a laminated film having a polyolefin-based resin layer on at least one surface of a polyester film, the polyolefin-based resin layer including a polyolefin-based resin having a methylpentene unit and at 100% elongation at 100 ° C. The present inventors have investigated that this problem can be solved at once by using a laminated film having a haze change of 0 to 10%.
Hereinafter, the laminated film of the present invention will be specifically described.
(polyester)
The polyester of the polyester film used in the present invention consists of a polymer basically composed of a dicarboxylic acid component and a glycol component.

  Examples of the dicarboxylic acid component include isophthalic acid, terephthalic acid, diphenyl-4,4′-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalene-2,7-dicarboxylic acid, and naphthalene-1,5-dicarboxylic acid. , Diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid, malonic acid, 1,1-dimethylmalonic acid, succinic acid, glutaric acid Adipic acid, sebacic acid, decamethylene dicarboxylic acid and the like can be used.

  Examples of the glycol component include ethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, aliphatic glycols such as 1,3-propanediol and spiroglycol, alicyclic glycols such as cyclohexanedimethanol, and bisphenol. A glycol component such as aromatic glycol such as -A or bisphenol-S, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene glycol-propylene glycol copolymer, or the like can be used.

The polyester of the polyester film used in the present invention is specifically polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), polyhexamethylene terephthalate (PHT), polyethylene naphthalate (PEN), Examples thereof include polypropylene naphthalate (PPN), polybutylene naphthalate (PBN), polycyclohexanedimethylene terephthalate (PCT), polyhydroxybenzoate (PHB) and the like. Two or more kinds of these polyesters can be used in combination.
(Polyester film)
The polyester film used for the laminated film of the present invention comprises a polyolefin resin layer containing a polyolefin resin having a methylpentene unit on at least one side (hereinafter, a polyolefin resin layer containing a polyolefin resin having a methylpentene unit is simply methylated). A polyolefin-based resin layer having a pentene unit). The method for laminating the polyolefin resin layer on the polyester film is not particularly limited, but the polyolefin resin having methylpentene units is dissolved in an organic solvent, and the solution is coated on one or both sides of the polyester film and then a solvent is added. A drying method is preferably used. When a polyolefin resin layer having a methylpentene unit is laminated by this method, the polyester film is deteriorated in the flatness of the film surface due to contact with an organic solvent, and as a result, printing defects may occur when printed on the laminated film. is there. Therefore, it is preferable that the polyester film used for the laminated film of the present invention has chemical resistance at least on the contact surface with the polyolefin resin layer having a methylpentene unit.

  Examples of a method for imparting chemical resistance to a polyester film include a method using biaxial stretching, a method using a laminated polyester film in which a highly crystalline polyester is laminated on the surface layer of an unstretched polyester film, and the like as a polyester film. The method may be used. However, when the laminated film of the present invention is transferred to a transfer object having a deep drawing or a complicated surface shape, high formability is required for a film for use as a transfer foil. Therefore, it is used for the laminated film of the present invention. As the polyester film, a laminated polyester film obtained by laminating a highly crystalline polyester layer on a polyester layer with low crystallinity such as unstretched is used as the polyester film. That is, as the laminated film of the present invention, other polyester layers ( It is preferable to successively laminate in the order of a polyester layer other than the highly crystalline polyester layer) / a highly crystalline polyester layer / a polyolefin resin layer having a methylpentene unit.

  Here, the highly crystalline polyester layer is the difference between the cold crystallization temperature (Tc) and the glass transition temperature (Tg) observed in the temperature rising process when the powder obtained by scraping the layer is subjected to differential scanning calorimetry (DSC). It refers to a layer having a difference in crystallinity parameter ΔTcg of 35 ° C. or less. In general, the smaller the value of ΔTcg, the easier it is to crystallize. From the viewpoint of further improving the chemical resistance of the laminated polyester film, ΔTcg of the highly crystalline polyester layer of the laminated polyester film is more preferably 25 ° C. or less, and particularly preferably 20 ° C. or less. Moreover, as a minimum of (DELTA) Tcg, 7 degreeC or more is preferable from a film forming viewpoint, and 10 degreeC or more is more preferable.

  From the standpoint of curling phenomenon of the film due to differences in stretching stress of each layer due to temperature, humidity, etc. and handling of the film, the polyester film used in the present invention is at least a highly crystalline polyester layer and other polyester layers. A laminated polyester film consisting of two layers is preferred. More specifically, when layer A is a highly crystalline polyester layer and layer B is a polyester layer other than the highly crystalline polyester layer, layer A / layer B is obtained by laminating layer A on both sides of layer B. Particularly preferred is a film structure of / layer A. Here, layer A / layer B / layer A is a film configuration comprising two types and three layers in which the respective layers are laminated in this order. However, it may be a film configuration such as layer A / layer B in which layer A is laminated only on one side of layer B, or layer A / layer B / layer A / layer B in which another polyester layer is laminated. . The other polyester layer refers to a polyester layer having a difference in crystallinity parameter ΔTcg of greater than 35 ° C.

  In the laminated polyester film used in the present invention, the crystallization index Xs of the highly crystalline polyester layer (layer A) and the crystallization index Xc of the other polyester layer (layer B) are 20 ≧ Xs−Xc ≧ 4 (% ), Preferably 18 ≧ Xs−Xc ≧ 6 (%), particularly preferably 16 ≧ Xs−Xc ≧ 8 (%). If the value of Xs−Xc is out of the above range, the printability tends to deteriorate, which is not preferable.

In the present invention, the crystallization index (Xs or Xc) of each of the stacked layers can be calculated by [Equation 1] from data obtained by differential scanning calorimetry (DSC). In the case of calculating the crystallization index of each layer in the laminated film, the crystallization index can be calculated by analyzing after removing the layer other than the layer to be measured with a scissors or a cutter knife. That is, when calculating the crystallization index Xs of the highly crystalline polyester layer, if the targeted highly crystalline polyester layer is covered with a release layer or the like and is not exposed on the surface, the targeted highly crystalline polyester layer Until the surface is exposed, the release layer is removed with a scissors or a cutter knife, the exposed highly crystalline polyester layer is scraped with a scissors or a cutter knife, and the resulting sample is analyzed to analyze the crystallization index Xs Can be calculated. The same applies to the other polyester layers.
Crystallization index: X (%) = (Sm−Sc) / Sm × 100 (Equation 1)
Here, X is a crystallization index, Sc is a calorific value at the time of crystallization, and Sm is an endothermic amount at the time of melting.
(Highly crystalline polyester layer)
The composition of the highly crystalline polyester layer of the laminated polyester film used in the present invention is such that at least one polyester selected from PPT, PBT, PPN and PBN is 50-100 in a total mass of 100% by mass of the highly crystalline polyester layer. It is preferable to contain by mass. These polyesters are more preferably contained in an amount of 70 to 100% by mass, and particularly preferably 90 to 100% by mass. When these polyesters are less than 50% by mass, it is difficult to design the crystallinity parameter ΔTcg of the layer to 35 ° C. or less, and a high crystalline polyester layer cannot be obtained. It is difficult to achieve the crystallization index necessary to obtain the properties.

The polyester contained in the highly crystalline polyester layer is most preferably PBT because of its high crystallinity. In addition, you may contain 0-50 mass% of other components in a highly crystalline polyester layer. As other components, polyesters other than the above specific polyester are preferable, and PET is more preferable. The PET herein includes copolymerized PET, for example, copolymerized PET obtained by copolymerizing isophthalic acid in an amount of about 5 to 30 mol%.
(Other polyester layers)
Another polyester layer refers to a polyester layer having a crystallinity parameter ΔTcg of greater than 35 ° C.

  The polyester contained in the other polyester layer preferably contains a naphthalenedicarboxylic acid component and / or a terephthalic acid component in an amount of 90 mol% to 100 mol% in 100 mol% of all dicarboxylic acid components of the polyester.

  Moreover, it is preferable that the polyester contained in another polyester layer contains 20-99.9 mol% of ethylene glycol components in 100 mol% of all the glycol components of the polyester, More preferably, 50-99.9 mol%, More preferably, it is 20-99.9 mol%. Furthermore, in 100 mol% of the total glycol component of the polyester contained in the other polyester layer, selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and spiroglycol. The content of at least one diol is preferably 0.1 to 80 mol%, more preferably 0.1 to 50 mol%, and still more preferably 0.1 to 40 mol%. The proportion of the ethylene glycol component in 100 mol% of the total glycol component of the polyester contained in the other polyester layer is out of the range of 20 to 99.9 mol%, or 1 in 100 mol% of the total glycol component of the polyester. When the proportion of at least one diol component selected from the group consisting of 3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and spiroglycol is out of the range of 0.1 to 80 mol%, Since heat resistance, productivity, and moldability are likely to deteriorate, it is not preferable.

  Specific examples of polyesters suitable for other polyester layers having such a composition include PET, 1,4-cyclohexanedimethanol copolymerized PET (PETG), spiroglycol copolymerized PET, PEN, PPT, PBT, A polyester mixture or copolymer selected from the group consisting of PPN and PBN is preferred. When using a mixture or copolymer of these polyesters, from the viewpoint of cost and moldability, PET, 1,4-cyclohexanedimethanol copolymerized PET (hereinafter referred to as PETG), spiroglycol copolymerized PET, etc. PEN, PPT, PBT, PPN, or PBN is preferably mixed or copolymerized with the PET component.

The polyester having a specific composition is, for example, a method in which two or more kinds of polymer pellets are blended and supplied to an extruder and kneaded in the extruder to obtain a polyester having an arbitrary component structure (dry blend method). It can be obtained by a known method such as a method of obtaining a polyester of an arbitrary component by polymerization using a monomer (copolymerization method) or a method combining a dry blend method and a copolymerization method. From the viewpoint of polymer production cost, productivity, and heat resistance, it is preferable to use a dry blend method.
(Reaction catalyst during production, anti-coloring agent)
When manufacturing the polyester used as the raw material of the polyester film used in the laminated film of the present invention, conventionally used reaction catalysts and coloring inhibitors can be used. As the reaction catalyst, for example, alkaline earth metal compounds, zinc compounds, lead compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, titanium compounds, and the like can be used. As a coloring inhibitor, for example, a phosphorus compound or the like can be used. Preferably, an antimony compound, a germanium compound or a titanium compound is added as a reaction catalyst at any stage before the production of the polyester is completed. As a method of adding the reaction catalyst, for example, a method of adding the powder of the reaction catalyst as it is, a method of dissolving the reaction catalyst in the glycol component which is a starting material of polyester, and the like can be used. .

The antimony compound is not particularly limited, and for example, antimony oxide such as antimony trioxide, antimony acetate, or the like can be used.
Further, the titanium compound is not particularly limited, but alkyl titanate compounds such as tetraethyl titanate and tetrabutyl titanate, and composite oxides of titanium and an element selected from silicon, zirconium and aluminum can be preferably used.

  When the polyester film used in the laminated film of the present invention is used by mixing two or more kinds of polyesters, it is preferable to satisfy M / P ≦ 1. Here, M in the formula represents the concentration (mmol%) of the catalytic metal element remaining in the polyester, and P represents the concentration (mmol%) of the phosphorus element remaining in the polyester. These M and P are expressed as a concentration with respect to 1 unit (mol) of the repeating unit of the polyester. More preferably, M / P is 0.0001 or more and less than 1, and particularly preferably 0.001 or more and 0.8 or less. Moreover, when the polyester film used by the laminated film of the present invention has a laminated structure of at least two layers (in the case of a laminated polyester film), the above conditions are preferably satisfied for each layer.

  By controlling M / P ≦ 1, it is possible to suppress the transesterification of two or more kinds of polyesters, increase the thermal stability of the polyester, and suppress the lowering of the melting point due to heat treatment such as melt extrusion. It is. As a result, the heat resistance, solvent resistance and printability of the polyester can be improved, and quality variations can be further reduced.

  Examples of a method for controlling the phosphorus element in the polyester within the above range include addition of a phosphorus compound to the polyester. Although it does not specifically limit as a phosphorus compound added to polyester, Phosphoric acid, phosphorous acid, phosphate ester, etc. are preferable. Among such phosphorus compounds, a phosphorus compound having a molecular weight of 300 or more, more preferably 400 or more is preferably used from the viewpoint of suppressing bleed-out during film production. Examples of the phosphorus compound having a molecular weight of 300 or more include stearyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate and the like. Stearyl phosphate is particularly preferably used from the viewpoint of bleed-out suppression. The content (addition amount) of the phosphorus compound is 20 to 1000 mmol% based on one unit (mol) of the repeating unit of the polyester with the phosphorus compound as the phosphorus element amount from the viewpoint of thermal stability, color tone, and the like. More preferably, it is 90 to 900 mmol%, particularly preferably 120 to 800 mmol%.

As a method for adding such a phosphorus compound, either a method of adding at the time of polymerization or a method of adding it to the extruder together with the polymer may be used. In general, since a polymerization reaction is inhibited when a large amount of a phosphorus compound is added at the time of polymerization, a method of supplying it together with polyester to an extruder is preferred.
(Viscosity of polyester)
It is preferable to use what has the intrinsic viscosity of the polyester in the polyester film used for the laminated | multilayer film of this invention in the range of 0.6-1.3 dl / g, respectively. More preferably, it is 0.65-1.2 dl / g, Most preferably, it is the range of 0.7-1.1 dl / g. If the intrinsic viscosity is less than 0.6 dl / g, the moldability of the polyester film in the laminated film may be lowered. Moreover, when intrinsic viscosity exceeds 1.3 dl / g, productivity will fall or the thickness spot of a polyester film will become remarkable, and as a result, a thickness spot tends to arise also in a laminated film. Moreover, when the polyester film used by the laminated film of this invention is a laminated polyester film which has a laminated structure of at least 2 layers, it is preferable to satisfy | fill the said conditions about polyester used by each layer.

Moreover, when the polyester film used for the laminated film of the present invention has a laminated polyester film structure having at least two layers of a highly crystalline polyester layer and another polyester layer, the difference in intrinsic viscosity of the polyester in each layer is preferably Is less than 0.4 dl / g, more preferably less than 0.2 dl / g, and particularly preferably less than 0.1 dl / g. When the difference in intrinsic viscosity is within the above range, unevenness in the thickness of each layer of the polyester film in the width direction is less likely to occur, and productivity is improved.
(DSC crystal melting peak of polyester film)
In the polyester film used in the laminated film of the present invention, the DSC curve obtained by differential scanning calorimetry (in a nitrogen atmosphere, at a heating rate of 20 ° C./min) has a substantially single crystal melting peak. It is preferable. When there are two or more DSC crystal melting peaks, the molecular structure is not uniform, and the moldability may be poor. Here, a shoulder peak (minimum point of the peak) having a heat of fusion partially overlapping one endothermic curve of 2 J / g or more is also regarded as an independent crystal melting curve peak.

In the case where the polyester film used in the laminated film of the present invention is a laminated polyester film having a laminated structure of at least two layers, the above conditions (differential scanning calorimetry (in a nitrogen atmosphere, temperature increase rate 20 ° C. / It is preferable that the DSC curve obtained in (min) shows substantially a single crystal melting peak). Examples of the method for confirming the crystal melting peak of each layer include a method of subjecting powder obtained by scraping the surface layer and inner layer of the film to differential scanning calorimetry (DSC).
(Polyester film thickness)
The thickness of the polyester film used in the laminated film of the present invention is preferably in the range of 10 to 600 μm, more preferably 20 to 400 μm, and particularly preferably 40 to 300 μm. When the thickness of the polyester film is less than 10 μm, the rigidity, production stability and flatness of the film are lowered, and wrinkles are easily formed during molding, which is not preferable. Moreover, when the thickness of a polyester film exceeds 600 micrometers, a handleability and a moldability may be aggravated.

In the case where the polyester film used in the laminated film of the present invention is a laminated polyester film having at least two layers of a highly crystalline polyester layer and another polyester layer, a viewpoint of improving all of printability, transferability and moldability Therefore, the thickness of one layer unit of the highly crystalline polyester layer is preferably in the range of 0.1% to 30% and 2 μm to 120 μm with respect to 100% of the total thickness of the polyester film, and the total thickness of the polyester film is 100 More preferably, the range is 0.2% to 20% and 4 μm to 80 μm. If the thickness of the highly crystalline polyester layer is too thin, chemical resistance and heat resistance may be insufficient, and printability and transferability may deteriorate. On the other hand, if the thickness of the highly crystalline polyester layer is too thick, the moldability may be insufficient. The other polyester layer preferably has a thickness of one layer unit of 70 to 99.9% and 10 μm to 500 μm with respect to 100% of the total thickness of the polyester film, 80 to 99.8% and 20 μm to 400 μm. More preferably. If the thickness of the other polyester layer is too thin, the moldability may be insufficient. If the thickness of the other polyester layer is too thick, the heat resistance may be reduced, and the printability and transferability may be insufficient. .
(surface treatment)
The polyester film used in the laminated film of the present invention can improve the coating properties of a liquid material of a polyolefin resin having a methylpentene unit, if necessary, by performing a surface treatment such as a corona discharge treatment. is there. Further, it can be used after being subjected to molding processing such as embossing, printing, or the like, if necessary.
(Production method of polyester film)
When a laminated polyester film is used as the polyester film used in the laminated film of the present invention, a known method such as a co-extrusion method, an extrusion lamination method, an extrusion coating method, a fusion method, or a combination thereof is used. Can be manufactured. The coextrusion method is preferably used in terms of film handling properties, productivity, manufacturing costs, and the like.

  The coextrusion method is a method in which polyesters constituting each layer are supplied from a plurality of extruders to a single die and simultaneously extruded to produce a laminated film, and there are a T-die method and an inflation method. The polyester film can be produced by either the T-die method or the inflation method, but the T-die method is preferably used from the viewpoint of productivity.

  Typical examples of the T-die method include a laminar flow method using a single manifold die, an intra-die lamination method using a multi-manifold die, and an outer die lamination method using a dual slot die. The polyester film used for the laminated film of the present invention can be produced by any method, but the laminar flow method and the in-die lamination method are preferably used from the viewpoint that the unevenness of the laminated thickness in the width direction is small and the productivity is good. be able to. Moreover, when laminating a polyester of a highly crystalline polyester layer and a polyester layer that is not highly crystalline, if the viscosity difference between the layers is large, the in-die lamination method can be particularly preferably used.

  When manufacturing by the T-die method, the polyester film used for the laminated film of the present invention can be manufactured by taking the multilayer sheet coextruded from the die onto a cast drum. The temperature of the cast drum is particularly preferably set to a temperature in the vicinity of the upper limit of the temperature range in which the molten sheet extruded from the die does not stick to the cast drum. By setting the temperature of the cast drum in such a range, crystallization of the polyester in the highly crystalline polyester layer can be advanced.

  If the temperature of the cast drum is too low, crystallization of the polyester of the highly crystalline polyester layer is difficult to proceed, and printability and transferability may be deteriorated. On the other hand, if the temperature of the cast drum is too high, the film tends to stick to the cast drum and the productivity may deteriorate, and the polyester in the polyester layer will crystallize, resulting in high stress during molding, and moldability. May decrease.

  Regarding the temperature setting of the casting drum, for example, a casting method as described in paragraphs 17 to 19 of JP 2000-103000 A is also preferable. In other words, the surface temperature of the cast drum when the molten film is in contact with the cast drum is set to be equal to or higher than the Tg of the polyester of the high crystalline polyester layer, and the surface temperature of the cast drum immediately before peeling from the cast drum is high crystalline. A method in which the laminated film of the present invention is produced by a casting method set to be less than Tg of the polyester of the polyester layer and the surface layer is crystallized more specifically can also be preferably used.

When the unstretched film after casting is made of a highly crystalline polyester, it can be biaxially stretched to improve chemical resistance. The stretching method may be either simultaneous biaxial or sequential biaxial stretching, but the unstretched sheet is stretched and heat-treated in the longitudinal direction and width direction of the film to obtain a film having a desired degree of plane orientation. Preferably, the tenter method is preferred in terms of film quality. After stretching in the longitudinal direction, a sequential biaxial stretching method in which the film is stretched in the width direction, and a simultaneous biaxial stretching method in which the longitudinal direction and the width direction are stretched almost simultaneously. Is desirable. The draw ratio is 1.5 to 4.0 times in each direction, preferably 1.8 to 4.0 times. Either the stretching ratio in the longitudinal direction or the width direction may be increased or the stretching ratio may be the same. The stretching speed is desirably 1000% / min to 200000% / min, and the stretching temperature can be any temperature as long as it is not less than the glass transition temperature of the polyester and not less than the glass transition temperature + 80 ° C. 80-150 degreeC is preferable. Further, the film is heat-treated after biaxial stretching, and this heat treatment can be performed by any conventionally known method such as in an oven or on a heated roll. The heat treatment temperature can be any temperature of 120 ° C. or higher and 245 ° C. or lower, but is preferably 120 to 240 ° C. Moreover, although the heat processing time can be made arbitrary, it is preferable to carry out normally for 1 to 60 seconds. The heat treatment may be performed while relaxing the film in the longitudinal direction and / or the width direction. Furthermore, re-stretching may be performed once or more in each direction, and then heat treatment may be performed.
(Polyolefin resin with methylpentene units)
The amount of the polyolefin resin having a methylpentene unit is not particularly limited as long as it has a methylpentene unit in the polyolefin resin. However, from the viewpoint of releasability and chemical resistance, a polyolefin resin having a more preferable methylpentene unit is a polyolefin containing 50 to 100% by mass of a methylpentene unit in 100% by mass of the polyolefin resin having a methylpentene unit. Yes, more preferably 70 to 100% by mass.

The polyolefin resin layer having a methylpentene unit is not particularly limited as long as the polyolefin resin layer having the methylpentene unit is included. Examples of the methylpentene unit include 4-methyl-1-pentene, 3-methyl-1-pentene, and 2-methyl-1-pentene. These methylpentenes can be used alone or in combination of two or more.
(Molecular weight)
The polyolefin resin having a methylpentene unit used in the present invention has a ratio (Mw / Mn) of mass average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 1. It is in the range of 0.0 to 3.5, preferably 1.0 to 3.0, more preferably 1.0 to 2.8, and still more preferably 1.5 to 2.8. When the value of Mw / Mn is large, it is disadvantageous for expressing mechanical properties such as toughness of the polymer. If the value of Mw / Mn is in the range of 1.0 to 3.5, it is advantageous for expressing mechanical properties such as toughness, and is industrially valuable.

As for the molecular weight of the polyolefin resin having a methylpentene unit used in the present invention, the mass average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,000 to 10,000,000 in terms of polystyrene. And more preferably 1,500 to 5,000,000.
(viscosity)
The polyolefin resin having a methylpentene unit used in the present invention has an intrinsic viscosity [η] of 0.5 (dl / g) or more, preferably 1.0 to 20 (dl / g), more preferably 1.2. -10 (dl / g).
(Melting point)
The melting point of the polyolefin resin having a methylpentene unit used in the present invention is preferably 140 ° C to 235 ° C, more preferably 150 ° C to 230 ° C, and further preferably 160 ° C to 225 ° C. If the melting point of the polyolefin-based resin having a methylpentene unit is too low, the heat resistance may be insufficient and the printability and transferability may be lowered. If the melting point is too high, the moldability may be insufficient.
(Vicat softening temperature)
The Vicat softening temperature of the polyolefin resin layer of the laminated film of the present invention is preferably 30 to 175 ° C, more preferably 40 to 170 ° C, still more preferably 50 to 155 ° C, and particularly preferably 50 to 120 ° C. If the Vicat softening temperature of the polyolefin-based resin layer is too low, the heat resistance may be insufficient and printability and transferability may be lowered. If the melting point is too high, the moldability may be insufficient.

  The laminated film of the present invention may be coated with a coating for the purpose of imparting various functionalities. However, a coating such as a UV curable type is used as a recent coating, and a UV curable type is used. Since the coating agent decomposes such as foaming at a high temperature (around 120 ° C. or higher), the molding temperature is being lowered (80 ° C. to 120 ° C.). When the laminated film of the present invention is used as a protective film or transfer foil when the Vicat softening temperature of the polyolefin resin layer is in the range of 30 to 175 ° C, in a low temperature region such as 80 to 120 ° C, It is preferable because both heat resistance and molding followability to an adherend or subject are excellent. As a method for setting the Vicat softening temperature of the polyolefin resin layer of the laminated film of the present invention in the range of 30 to 175 ° C., an olefin having 2 to 20 carbon atoms in a methylpentene unit such as 4-methyl-1-pentene. The method of copolymerizing a unit is mentioned. However, unless otherwise specified, olefin units having 2 to 20 carbon atoms in the present specification do not include methylpentene units such as 4-methyl-1-pentene. Examples of the olefin unit having 2 to 20 carbon atoms include linear or branched α-olefins, cyclic olefins, aromatic vinyl compounds, conjugated dienes, non-conjugated polyenes, and functionalized vinyl compounds.

The Vicat softening temperature can be measured by a method of ASTM D1525 (2007 model) by preparing a test piece by injection molding from a polyolefin-based resin having a methylpentene unit. Moreover, when it is desired to measure the Vicat softening temperature of a polyolefin resin having a methylpentene unit in a laminated film, for example, using fine sandpaper of # 1000 to # 1500, the methylpentene unit on one surface layer is changed. It is possible to scrape off the polyolefin-based resin layer and prepare a test piece by injection molding from the obtained powder and measure it.
(Olefin unit having 2 to 20 carbon atoms)
An olefin unit having 2 to 20 carbon atoms is preferably used for the polyolefin-based resin having a methylpentene unit. Examples of the olefin unit having 2 to 20 carbon atoms include linear or branched α-olefins, cyclic olefins, aromatic vinyl compounds, conjugated dienes, non-conjugated polyenes, and functionalized vinyl compounds. These will be described below.

  Specific examples of the linear or branched α-olefin contained in the polyolefin-based resin having a methylpentene unit used in the present invention include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, etc., a linear α-olefin having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms; For example, 3-methyl-1-butene, 3-ethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3-ethyl-1-hexene Preferably, the branched α-olefin having 5 to 20 and more preferably 5 to 10 is used.

  Examples of the cyclic olefin include those having 3 to 20 carbon atoms, preferably 5 to 15 such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, vinylcyclohexane and the like.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p- Mono or polyalkyl styrenes such as ethyl styrene are mentioned.

  Examples of the conjugated diene include 1,3-butadiene, isoprene, chloroprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 4-methyl-1,3-pentadiene, 1,3-pentadiene, and 1,3-hexadiene. Examples thereof include those having 4 to 20 carbon atoms, preferably 4 to 10 carbon atoms such as 1,3-octadiene.

  Examples of the non-conjugated polyene include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2, -Methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1 , 4,8-decatriene (DMDT), dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylene norbornene, 5-vinyl norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene 2-norbornene, 6-chloromethyl-5-isopropylene-2-norbornene, 2,3-diisopropylide 5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene having 5 to 20 carbon atoms such as, preferably include the 5 to 10.

  Functionalized vinyl compounds include hydroxyl group-containing olefins, halogenated olefins, acrylic acid, propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid and 8-nonenoic acid. , Unsaturated carboxylic acids such as 9-decenoic acid, unsaturated amines such as allylamine, 5-hexeneamine, 6-hepteneamine, (2,7-octadienyl) succinic anhydride, pentapropenyl succinic anhydride and the above In the examples of compounds in the saturated carboxylic acids, unsaturated acid anhydrides such as compounds in which the carboxylic acid group is replaced with a carboxylic anhydride group, in the examples of compounds in the unsaturated carboxylic acids, the carboxylic acid group is converted to a carboxylic acid Unsaturated carboxylic acid halides such as compounds substituted with halide groups, 4-epoxy-1-butene, 5-epoxy-1-pen 6-epoxy-1-hexene, 7-epoxy-1-heptene, 8-epoxy-1-octene, 9-epoxy-1-nonene, 10-epoxy-1-decene, 11-epoxy-1-undecene, etc. Of unsaturated epoxy compounds.

  The hydroxyl group-containing olefin is not particularly limited as long as it is a hydroxyl group-containing olefin compound, and examples thereof include terminal hydroxylated olefin compounds. Specific examples of the terminal hydroxylated olefin compound include vinyl alcohol, allyl alcohol, hydroxylated 1-butene, hydroxylated 1-pentene, hydroxylated 1-hexene, hydroxylated 1-octene, and hydroxylated-1 -Decene, hydroxyl-1-dodecene, hydroxyl-1-tetradecene, hydroxyl-1-hexadecene, hydroxyl-1-octadecene, hydroxyl-1-octadecene, hydroxyl-1-eicocene, etc., preferably 2-20, preferably 2 10 linear hydroxylated α-olefins; for example, hydroxylated 3-methyl-1-butene, hydroxylated 3-ethyl-1-pentene, hydroxylated-4,4-dimethyl-1-pentene, hydroxylated Preferably, 4-methyl-1-hexene, hydroxylated-4,4-dimethyl-1-hexene, hydroxylated 4-ethyl-1-hexene, hydroxylated 3-ethyl-1-hexene and the like are preferably 5 to 20 , Yo More preferably, 5-10 branched hydroxylated α-olefins are mentioned.

Specific examples of the halogenated olefin include halogenated α-olefins having a group 17 atom of the periodic table such as chlorine, bromine and iodine, such as vinyl halide, halogenated-1-butene, halogenated-1-pentene, and halogen. -1-hexene, halogenated-1-octene, halogenated-1-decene, halogenated-1-dodecene, halogenated-1-tetradecene, halogenated-1-hexadecene, halogenated-1-octadecene, halogenated A linear halogenated α-olefin having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, such as -1-eicosene; for example, halogenated-3-methyl-1-butene, halogenated-3-ethyl-1- Pentene, halogenated-4,4-dimethyl-1-pentene, halogenated-4-methyl-1-hexene, halogenated-4,4-di Preferably a branched halogenated α-olefin of 5-20, more preferably 5-10, such as til-1-hexene, halogenated-4-ethyl-1-hexene, halogenated-3-ethyl-1-hexene, etc. Is mentioned.
(Thickness of polyolefin resin layer having methylpentene unit)
The thickness of the polyolefin resin layer having a methylpentene unit contained in the laminated film of the present invention is preferably in the range of 0.1 to 50 μm, more preferably 0.1 to 20 μm, and More preferably, it is 2-5 micrometers, and it is especially preferable that it is 0.3-2 micrometers. When the thickness is less than 0.1 μm, sufficient releasability cannot be obtained, and when it exceeds 50 μm, the releasability may not only be lowered, but the cost is increased.
(Configuration of laminated film)
The laminated film of the present invention is not particularly limited as long as it has a polyolefin resin layer on at least one surface of the polyester film, and even if it has a polyolefin resin layer having a methylpentene unit on one surface of the polyester film, You may have the polyolefin-type resin layer which has a methyl pentene unit on both surfaces of a polyester film. In the case of a laminated film having the polyolefin-based resin layer on both sides, it is effective in terms of curling suppression of the laminated film and improving handleability, but from the viewpoint of cost, a laminated film having the polyolefin-based resin layer on one side is more preferable. .
(Method for forming a polyolefin resin layer having a methylpentene unit)
The method for forming a polyolefin-based resin layer having a methylpentene unit used in the present invention may be prepared in advance by forming a film made of a polyolefin-based resin having a methylpentene unit, and may be bonded to a polyester film. A liquid material obtained by dissolving a polyolefin-based resin having a solvent in a solvent may be coated on a polyester film and then dried. However, from the viewpoint of ease of thinning and simplification of the process, it has a methylpentene unit. A method in which a liquid material obtained by dissolving a polyolefin resin in a solvent is applied to a polyester film and then dried.

  When a polyester film and a film (layer) made of a polyolefin resin having a methylpentene unit are bonded together, it is preferable to use an adhesive for the bonding. The adhesive may be a thermosetting type or a thermoplastic type, but is preferably a thermosetting type. For example, polyurethane resins, polyester resins, polyvinyl chloride resins, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, methyl methacrylate-butadiene copolymers, rubber resins such as chloroprene and polybutadiene, poly From acrylic ester resins, polyvinylidene chloride resins, polybutadiene, or carboxyl modified products of these resins, epoxy resins, cellulose derivatives, ethylene vinyl acetate copolymers, polyethylene oxide, acrylic resins, lignin derivatives, etc. The adhesive which becomes is mentioned. From the viewpoint of adhesion between the polyester film and a film made of polyolefin resin having a methylpentene unit, an adhesive made of polyurethane resin or polyester resin is preferable. In addition, a polyester film and a film (layer) made of a polyolefin resin having a methylpentene unit may be bonded to each other by providing an adhesive resin layer on the polyester film and subjecting the polyolefin resin having a methylpentene unit to melt extrusion lamination. I do not care.

  In the case of using a method of drying after applying a liquid material in which a polyolefin resin having methylpentene units is dissolved in a solvent, the solvent in the liquid material in which the polyolefin resin containing methylpentene units is dissolved is water, organic Examples include a solvent or an aqueous medium containing water and an amphiphilic organic solvent. From the viewpoint of drying speed and solubility, an organic solvent is preferably used.

  Examples of organic solvents include diethyl ketone (3-pentanone), methyl propyl ketone (2-pentanone), methyl isobutyl ketone (4-methyl-2-pentanone), 2-hexanone, 5-methyl-2-hexanone, and 2-to. Ketones such as butanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, aromatic hydrocarbons such as toluene, xylene, benzene, Solvesso 100, Solvesso 150, butane, pentane, hexane, cyclohexane, methyl Aliphatic hydrocarbons such as cyclohexane, heptane, octane, nonane, methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, o-dichlorobenzene, m- Dichlorobenzene, p-dichlorobenzene Halogen-containing compounds such as ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, γ-butyrolactone, isophorone, etc. And the following hydrophilic organic solvents. Among these, hexane, toluene, cyclohexane, and methylcyclohexane are preferably used because of the solubility of the polyolefin resin having a methylpentene unit used in the present invention.

  The solid content of the liquid material used in the present invention can be appropriately selected depending on the lamination conditions, the target thickness and performance, and is not particularly limited. In order to form a resin layer, 1-60 mass% is preferable and 5-30 mass% is more preferable.

  As a method of applying a liquid material obtained by dissolving a polyolefin resin having a methylpentene unit in a solvent to the polyester film used in the laminated film of the present invention, known methods such as gravure roll coating, reverse roll coating, wire Apply uniformly to the polyester surface used in the laminated film of the present invention by bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc., and set it near room temperature as necessary Then, by subjecting to a drying treatment or a heat treatment for drying, a uniform resin layer can be formed in close contact with the polyester film used in the laminated film of the present invention.

Further, when a polyolefin resin having a methylpentene unit is dissolved in various solvents, the resin is dissolved at a high concentration by using a known method such as JP 2006-131723 A, or JP 2006-130796 A. The adhesion between the polyester film and the polyolefin resin having a methylpentene unit may be improved by a known method such as
(Added particles)
Various particles can be added to each layer of the laminated film used in the present invention depending on the purpose and application. The particles to be added are not particularly limited as long as they are inactive to the polyester film and / or the polyolefin resin having a methylpentene unit, but the inorganic particles, the organic particles, the crosslinked polymer particles, and the interior formed in the polymerization system are not limited. Examples thereof include particles. Two or more kinds of these particles may be added. The addition amount of such particles is preferably 0.01 to 10% by mass, and more preferably 0.05 to 3% by mass.

  When it is the purpose of adding particles to impart easy lubricity to the laminated film used in the present invention, it is preferable to add particles only to the surface layer from the viewpoint of production cost and productivity. In general, the slipperiness is greatly influenced by the shape of the film surface, so that the slipperiness can be obtained by adding particles to the surface layer.

  The kind of the 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, phosphoric acid Various phosphates such as lithium, 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 and the like 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.

  As the internal particles generated in the polymerization system, particles generated by a known method in which an alkali metal compound, an alkaline earth metal compound or the like is added to the reaction system, and a phosphorus compound is further added are used.

For the laminated film used in the present invention, known additives as necessary, for example, flame retardants, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, plasticizers, tackifiers, polysiloxanes. An appropriate amount of an antifoaming agent such as a coloring agent such as a pigment or a dye can be blended.
(Antistatic agent)
Each layer of the laminated film used in the present invention preferably contains an antistatic agent or is copolymerized. As such an antistatic agent, various known antistatic agents such as anionic, cationic, nonionic and amphoteric can be used. Among these, it is particularly preferable to use sodium alkylsulfonate or sodium alkylbenzenesulfonate which is an anionic antistatic agent from the viewpoint of heat resistance. Moreover, when adding these antistatic agents at the time of superposition | polymerization, it is preferable from points, such as handling property, to add antioxidant together. As such an antioxidant, various known ones such as a phenol-based antioxidant, a phosphite-based antioxidant, and a thioether-based antioxidant can be used. These compounds may be used by mixing a plurality of compounds.
(Elongation at break, stress)
In the laminated film of the present invention, the stress at 100% elongation in an atmosphere of 100 ° C. is preferably in the range of 0.5 to 60 MPa. As a recent coating material, a UV curable coating material or the like is used, and a UV curable coating material is decomposed such as foaming at a high temperature, so that the molding temperature is lowered. The upper limit temperature at which decomposition of the coating material starts is said to be about 120 ° C., and moldability at 80 to 120 ° C. is required. The laminated film used in the present invention preferably has a breaking elongation at 100 ° C. of 150% or more, more preferably 250% or more, and still more preferably, in order to give good forming followability as a transfer foil even at a low temperature. Is 500% or more, and the stress at 100% elongation at 100 ° C. is preferably 0.5 to 60 MPa, more preferably 0.5 to 30 MPa, and still more preferably 0.5 to 3 MPa. Good. When the elongation at break at 100 ° C. is less than 150%, or when the stress at 100% elongation at 100 ° C. is out of the range of 0.5 to 60 MPa, molding follow-up when transferring as a transfer foil to a transfer medium. May be insufficient. In addition, although the breaking elongation at 100 degreeC is so good that it is large, as a value which does not affect a printing layer or various coating agents, 1500% is an upper limit substantially used for various surface protection films and transfer foil use.

As a method for making the laminated film of the present invention have a breaking elongation at 100 ° C. of 150% or more and a stress at 100% elongation at 100 ° C. in the range of 0.5 to 60 MPa, Examples thereof include a method of imparting a specific composition, structure, and characteristics such that the polyester film to be used is a laminated polyester film composed of at least two layers of the above-described highly crystalline polyester layer and another polyester layer.
(Haze change)
In the laminated film of the present invention, it is important that the change in haze upon 100% elongation at 100 ° C. is 0 to 10%, preferably 0 to 7%, more preferably 0 to 4%. However, the haze change here is obtained by stretching the film in the machine direction and the width direction, respectively, and taking the average of the haze change in each direction. When the machine direction and the width direction of the film are not known, the film is stretched in any two vertical directions, and the average value when the difference in the haze change in each direction is the largest is taken. When the haze change at 100% elongation at 100 ° C. does not satisfy the range of 0 to 10%, the polyolefin resin layer containing methylpentene units contained in the laminated film of the present invention does not follow the stretching of the polyester film. In some cases, cracks may be formed, and printability and releasability may be insufficient due to deterioration of surface smoothness.

  As a method for setting the haze change of the laminated film of the present invention in the range of 0 to 10% at 100 ° C. in an atmosphere of 100%, a polyester film used for the laminated film is made of a high crystal as described above. Methylpentene units used in laminated films that have a specific composition, structure, and characteristics that make a laminated polyester film consisting of at least two layers of a conductive polyester layer and another polyester layer, have low stress and high elongation Examples thereof include a method in which a polyolefin-based resin having a specific composition, structure, and characteristics as described above is made flexible to improve stretchability of the polyester film.

  The laminated film of the present invention preferably has a haze value measured according to JIS-K-6714 (2001 model) of 0.1 to 50%, more preferably 0.1 to 20%, and still more preferably 0. .1-10%. When the haze is included in the range of 0.1 to 50%, when the laminated film of the present invention is used for various surface protective films, transfer foils, and the like, the state confirmation and printing of the adherend and the transfer target are performed. It is preferable because the state of the surface can be confirmed.

EXAMPLES Hereinafter, although this invention is demonstrated along an Example, this invention is not restrict | limited by these Examples. Various characteristics were measured by the following methods.
(1) Haze The haze of the laminated film was measured according to JIS-K-6714 (2001 model) using a haze meter STP-H-2 manufactured by Nippon Seimitsu Optical Co., Ltd. Measurement was performed from both sides, and the average value was defined as haze.
In addition, about the haze change at the time of 100% elongation at 100 ° C., the haze before elongation is measured for each of the machine direction measurement sample and the width direction measurement sample described in (2) below, and the average is obtained. Furthermore, the haze after extending | stretching by the method of following (2) was measured about each of the machine direction and the width direction, and the average was calculated | required. And it subtracted the haze average value before extending | stretching from the haze average value after expansion | extension, and calculated | required the value (In the table | surface, the average in both sides of the value which subtracted the haze average value before expansion | extension from the haze average value after expansion | extension) The difference was expressed as Δhaze.)
(2) Stress at 100% elongation at 100 ° C. and elongation at break at 100 ° C. A sample having a length of 150 mm and a width of 10 mm from the laminated film was measured for a machine direction (length is 150 mm in the machine direction). And a sample for measurement in the width direction (length is 150 mm in the width direction), measured according to ASTM-D-882-81 (Method A) at 100 ° C. and at a tensile speed of 200 mm / min. The stress at 100% elongation was determined, and the average of these values was defined as the stress at 100% elongation at 100 ° C.
Further, the breaking elongation in the machine direction and the width direction was determined under the same measurement conditions, and the average value of these values was defined as the breaking elongation at 100 ° C.
(3) Vicat softening temperature A test piece of 63.5 mm x 12.7 mm x 6.4 mm was prepared by injection molding from a polyolefin resin having methylpentene units to be measured, and measured by the method of ASTM D1525 (2007 type). did.
In addition, when measuring the Vicat softening temperature of the polyolefin resin layer having a methylpentene unit in the laminated film, for example, using fine sandpaper of # 1000 to # 1500, it has a methylpentene unit on the surface layer. Only the polyolefin resin layer was scraped off, and a test piece was prepared from the obtained powder by injection molding and measured.
(4) Crystallinity parameter ΔTcg
Each layer is scraped off from the laminated film, and a 5 mg sample is collected from the polyester film (in the case of a laminated polyester film, each layer), and a differential scanning calorimeter DSCII type manufactured by Seiko Instrument Co., Ltd. is used. The peak temperature of the endothermic melting curve when the temperature was raised from 0 ° C. to 300 ° C. at a rate of temperature rise of 20 ° C./min was defined as the melting point Tm. Further, the glass transition temperature Tg and the crystallization temperature Tc were measured under the same measurement conditions, and the crystallinity parameter ΔTcg was calculated from [Equation 5].
Crystallinity parameter: ΔTcg = Tc−Tg [Formula 5]
(5) Film Thickness and Layer Thickness When measuring the total thickness of the laminated film, the thickness at five arbitrary locations of the sample cut out from the film was measured using a dial gauge and averaged. When measuring the layer thickness of each layer of the laminated film, using a Leica DMLM manufactured by Leica Microsystems Co., Ltd., photographed the transmitted light under the condition of 100 times magnification of the cross section of the film, and the layers of each layer of the laminated film The thickness was measured.
(6) Release property Using a cup-type vacuum forming machine, after integrally forming the transfer foil and the resin under the conditions described in each of the following examples, the release property when peeling the laminated film from the molded product is as follows. Judged by criteria. A or B is acceptable.
Molding was performed with a cup shape having a diameter of 50 mm under the condition of a drawing ratio of 1.0, and under the best temperature condition.
A: The laminated film can be peeled off very finely, and no defects on the surface of the molded product due to uneven peeling are observed.
B: The laminated film can be peeled, but occasionally a defect derived from peeling unevenness is observed on the surface of the molded product.
C: The case where it did not correspond to A and B was set to C.
(7) Formability Using a cup-type vacuum forming machine, a transfer foil was formed under a temperature condition of 80 to 180 ° C., and the formability of the best formability was evaluated. Molding was performed with a cup shape having a diameter of 50 mm under a drawing ratio of 1.0, and the state of the transfer foil when molded under the best temperature conditions was observed and judged according to the following criteria. A or B is a pass level.
A: There is almost no deterioration in transparency due to delamination of a polyolefin resin layer having sharp corners and a polyester film and a methylpentene unit.
B: Corresponding to either a rounded corner or a deterioration in transparency due to delamination of a polyolefin resin layer having a polyester film and a methylpentene unit.
C: The case where it did not correspond to A and B was set to C.

The following polyesters, polyolefins, and particle masters were used in the examples and comparative examples.
(8) Intrinsic viscosity The intrinsic viscosity was calculated from [Formula 6] from the solution viscosity measured at 25 ° C in orthochlorophenol.
Intrinsic viscosity: [eta] sp / C = [[eta]] + K [[eta]] 2 * C [Formula 6]
Here, ηsp = (solution viscosity / solvent viscosity) −1, C is the dissolved polymer mass per 100 ml of solvent (1.2 g / 100 ml), and K is the Huggins constant (0.343). The solution viscosity and the solvent viscosity were measured using an Ostwald viscometer.
[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 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide are added with respect to the amount of dimethyl terephthalate, and the temperature is raised by a conventional method. Then, a transesterification reaction was performed. Subsequently, 0.020 mass% of 85% phosphoric acid aqueous solution was added to the transesterification 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 carried out 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 0.65 dl / g. .
[Polyethylene terephthalate B (PET-B)]
At the time of polymerization of PET-A, 6 parts by mass of sodium dodecylbenzenesulfonate and 4 parts by mass of polyethylene glycol (molecular weight 4000) as antistatic agents and “Irganox” (registered trademark) manufactured by Ciba Specialty Chemicals as an antioxidant ) 1010 0.10 parts by mass, and 6 parts by mass of agglomerated silica particles (manufactured by Fuji Divison, number average particle size 2.5 μm) obtained by the following method were further added, and polyethylene terephthalate resin (inherent viscosity 0.65 dl) / G, melting point 264 ° C.).

  Aggregated silica particles: 1 equivalent of oxygen and 1 equivalent of hydrogen were vaporized in a vaporizer with respect to 1 equivalent of silicon tetrachloride, and hydrolyzed at 1000 ° C. in an oxyhydrogen flame to obtain silicon oxide particles. Further, it was pulverized by a wet sand mill using beads having a diameter of 0.5 mm to obtain agglomerated silica having a desired number average particle size.

[1,4-Cyclohexanedimethanol copolymerized polyethylene terephthalate E (PET-C)]
“6763” (no melting point, intrinsic viscosity 0.72) manufactured by Eastman Chemical Co. was used. The copolymerization ratio of 1,4-cyclohexanedimethanol was 30 mol%.

[Polybutylene terephthalate A (PBT-A)]
“Toraycon” (registered trademark) 1200S manufactured by Toray Industries, Inc .: polybutylene terephthalate (melting point: 224 ° C., intrinsic viscosity: 1.26 dl / g) was used.

[Polybutylene terephthalate B (PBT-B)]
The antioxidant, antistatic agent and agglomerated silica particles used in PET-B were blended with PET-B in the same formulation as “Toraycon” (registered trademark) 1200S polybutylene terephthalate (melting point 224 ° C., inherent Viscosity 1.26 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 by the extruder is extruded from a die having a circular hole having a diameter of 5 mm, immediately cooled with cooling water at 10 ° C., and the obtained gut-shaped resin is cut at intervals of 4 mm to obtain polybutylene. Terephthalate pellets (melting point: 228 ° C., intrinsic viscosity: 1.26 dl / g) were obtained.

[Polyolefin resin having methylpentene unit (PMP-A)]
A polyolefin-based resin having a polymethylpentene unit (melting point: 157 ° C., Vicat softening temperature: 50 ° C.) was used.

[Polyolefin resin having methylpentene unit (PMP-B)]
A polyolefin-based resin having a polymethylpentene unit (melting point: 225 ° C., Vicat softening temperature: 153 ° C.) was used.

[Polyolefin resin having methylpentene unit (PMP-C)]
A polyolefin-based resin having a polymethylpentene unit (melting point: 235 ° C., Vicat softening temperature: 176 ° C.) was used.

[Polyolefin resin (polyolefin-D)]
Asahi Kasei Co., Ltd. product, Suntec-LD M6520: Low density polyethylene resin was used. The Vicat softening temperature of the piece obtained by injection molding was 81 ° C.
Example 1
Among the polyesters used for the polyester film, PBT-A and PBT-B are mixed as a surface layer polyester in the ratio of the table (layer A), and supplied to a vent type twin screw extruder (L / D = 36) at 250 ° C. After being melted in step 2, it was passed through two vacuum vents. Next, the resin was passed through a leaf disk filter having a filtration accuracy of 30 μm and then supplied to a multi-manifold die.

  Moreover, PET-A and PBT-A were mixed in the ratio of a table | surface as a polyester of an inner layer among the polyester used for a polyester film (layer B). Furthermore, 0.1 mass% of stearic acid (Asahi Denka Kogyo Co., Ltd. “Adeka Stub” (registered trademark) AX-71)) was added separately and supplied to a vent type twin screw extruder (L / D = 36). . After the supplied resin was melted at 280 ° C., it was passed through two vacuum vent portions. Next, the resin was passed through a leaf disk filter having a filtration accuracy of 30 μm and then supplied to a multi-manifold die.

  After each resin passed through the manifold in the die, the two types of resins were laminated so as to be layer A / layer B / layer A, and extruded from the slit-shaped die into a sheet. Electrostatic application was applied to both ends of the extruded sheet using a needle-like edge pinning device, and the surface was brought into close contact with a satin-finished casting drum to be cooled and solidified. The surface temperature of the casting drum was adjusted to 55 ° C. A polyester film having a layer thickness of 7.5 μm per layer A and a total film thickness of 75 μm was obtained.

  One side of the layer A of the obtained polyester film is subjected to a corona discharge treatment, and then a methylcyclohexane solution containing 10 wt% PMP-A is coated with a bar coat at a thickness of 1.8 μm (corresponding to a solid content). And dried at 80 ° C. for 1 minute to obtain a laminated film of the present invention. As the methylcyclohexane solution of PMP-A, a solution obtained by dissolving PMP-A in methylcyclohexane at room temperature for 3 days was used.

A top coat layer, a printing layer, and an adhesive layer were formed in this order on the surface of the obtained laminated film of the present invention coated with PMP-A to obtain a transfer foil.
As the top coat layer, an ultraviolet curable acrylic resin (“LAROMER” (registered trademark) LR8983 manufactured by BASF Japan) was used to form a layer having a thickness of 60 μm.
As a printing layer, using a polyurethane-based resin gravure ink ("Hiramic" (registered trademark) manufactured by Dainichi Seika Kogyo Co., Ltd., main solvent: toluene / methyl ethyl ketone / isopropyl alcohol, ink: 723B yellow / 701R white), A layer having a thickness of 70 μm was formed.
As the adhesive layer, an acrylonitrile-butadiene-styrene (ABS) copolymer resin film (ABS film “Hiflex” (registered trademark) manufactured by Okamoto Co., Ltd.) was used to form a layer having a thickness of 100 μm.

  Next, after heating the obtained transfer foil to a temperature of 80 ° C., using a vacuum molding machine, a cup-shaped molded body was produced with a 50 mm diameter cup concave mold at a temperature of 85 ° C. and a drawing ratio of 1.0. did.

Subsequently, acrylonitrile-butadiene-styrene (ABS) copolymer resin (ABS resin “Toyolac” (registered trademark) 930 manufactured by Toray Industries, Inc.) heated to 280 ° C. was poured into the cup-shaped molded body. After the ABS is cooled and solidified, the cup-shaped molded product obtained by injecting the ABS copolymer resin into the cup-shaped molded product is taken out from the mold, and the laminated film is peeled off. The layer was cured. The release properties and moldability of the laminated film prepared in this example were both good.
(Example 2)
Example 1 was repeated except that the composition of the polyester film was changed as shown in the table. The release properties and moldability of the laminated film prepared in this example were both good.
(Example 3)
The same procedure as in Example 1 was conducted except that the laminated structure of the polyester film was two layers of A / B. The release properties and moldability of the laminated film prepared in this example were both good.
Example 4
Of the polyester used for the polyester film, PET-B, PBT-A, and PET-C are mixed as the surface layer polyester at the ratio shown in the table (layer A) and supplied to the vent type twin screw extruder (L / D = 36). Then, after melting at 280 ° C., it was passed through two vacuum vents. Next, the resin was passed through a leaf disk filter having a filtration accuracy of 30 μm and then supplied to a multi-manifold die.

  Further, among the polyesters used for the polyester film, PET-A, PBT-A, and PET-C are mixed in the ratio shown in the table as the inner layer polyester (Layer B), and a vent type twin screw extruder (L / D = 36). ). After the supplied resin was melted at 280 ° C., it was passed through two vacuum vent portions. Next, the resin was passed through a leaf disk filter having a filtration accuracy of 30 μm and then supplied to a multi-manifold die.

  After each resin passed through the manifold in the die, the two types of resins were laminated so as to be layer A / layer B / layer A, and extruded from the slit-shaped die into a sheet. Electrostatic application was applied to both ends of the extruded sheet using a needle-like edge pinning device, and the sheet was brought into close contact with a casting drum having a surface temperature of 25 ° C. to be cooled and solidified to obtain an unstretched polyester film.

  Next, before stretching in the longitudinal direction, the film temperature is raised with a heated roll, the preheating temperature is 110 ° C., the stretching temperature is stretched in the longitudinal direction at 105 ° C., and immediately cooled with a metal roll whose temperature is controlled at 40 ° C. did. Next, the film was stretched 3.1 times in the width direction at a preheating temperature of 95 ° C. and a stretching temperature of 120 ° C. with a tenter-type transverse stretching machine, and while being relaxed by 4% in the width direction in the tenter, the temperature was maintained at 240 ° C. for 5 seconds. Heat treatment was performed to obtain a biaxially oriented polyester film having a thickness of 18.8 μm per layer A and a total film thickness of 188 μm.

After producing the polyester film, a transfer foil was produced in the same manner as in Example 1, and vacuum forming was performed. The release property and moldability of the laminated film produced in this example were both good.
(Examples 5-7, 9, 10)
The same procedure as in Example 1 was conducted except that the composition of the polyester film, the composition of the polyolefin resin having methylpentene units, the coating solvent, and the thickness were as shown in the table. The releasability and / or moldability of the laminated film produced in this example was good.
(Example 8)
The same procedure as in Example 8 was conducted except that the composition of the polyester film and the coating solvent for the polyolefin resin having methylpentene units were as shown in the table. The release property of the laminated film produced in this example was good.
(Example 11)
As in the table, the composition of the polyolefin resin having methylpentene units is as in the table, except that the coating solvent is a mixed solvent of cyclohexane and tetrahydrofuran (cyclohexane: tetrahydrofuran = 75 wt%: 25 wt%). did. The release property of the laminated film produced in this example was good.
(Comparative Example 1)
Except that the composition and thickness of the polyolefin-based resin having a methylpentene unit was changed as shown in the table, except that the coating solvent was a mixed solvent of cyclohexane and tetrahydrofuran (cyclohexane: tetrahydrofuran = 75 wt%: 25 wt%). Same as Example 8. The release film and moldability of the laminated film produced in this example were insufficient. This is presumably because the moldability of the polyester film constituting the laminated film and the polyolefin resin having a methylpentene unit were insufficient.
(Comparative Example 2)
The composition of the polyolefin resin having methylpentene units was changed to polyolefin-D, the coating solvent was changed to a mixed solvent of cyclohexane and tetrahydrofuran (cyclohexane: tetrahydrofuran = 75 wt%: 25 wt%), and the thickness was changed as shown in the table. In the same manner as in Example 8.

The moldability and releasability of the laminated film produced in this example was insufficient. This is because the polyolefin-D constituting the laminated film is deformed without being able to withstand preheating at the time of molding, resulting in surface peeling with the polyester film, and at the same time, the polyolefin layer has a thickness variation due to thermal deformation of the polyolefin resin layer. This is thought to be due to the deterioration of releasability.
(Comparative Example 3)
After producing a polyester film in the same manner as in Example 1, a transfer foil was produced by forming a topcoat layer, a printing layer, and an adhesive layer without coating a polyolefin-based resin having a methylpentene unit, and vacuum forming was performed. . Since the laminated film produced in this example did not have a release layer, the release property was insufficient.

  According to the present invention, it is possible to obtain a laminated film that is excellent in releasability, printability, environmental load at the time of disposal, and also excellent in moldability such as adherend at the time of molding and followability to the transfer target. Therefore, resin parts for building materials and optical applications, various surface protection films such as metal products and glass products, in-mold transfer foils used for printing and molding, automotive interior and exterior parts, bathroom panels, parts for household appliances, packaging It is preferably used as a transfer foil for transferring printing of containers and the like.

Claims (5)

A laminated film having a polyolefin resin layer on at least one side of a polyester film,
The polyolefin resin layer includes a polyolefin resin having a methylpentene unit,
A laminated film having a haze change of 0 to 10% at 100% elongation at 100 ° C.   2. The laminated film according to claim 1, wherein the polyolefin resin layer has a Vicat softening temperature of 30 to 175 ° C. 3.   The laminated film according to claim 1 or 2, wherein the polyolefin resin layer has a thickness of 0.1 to 50 µm.   The laminated film according to any one of claims 1 to 3, wherein the elongation at break at 100 ° C is 150% or more and the stress at 100% elongation at 100 ° C is in the range of 0.5 to 60 MPa. The polyester film is a laminated polyester film composed of at least two layers of a highly crystalline polyester layer and another polyester layer,
The highly crystalline polyester layer has a crystallinity parameter ΔTcg of 35 ° C. or less,
The laminated film according to any one of claims 1 to 4, wherein a polyolefin-based resin layer, a highly crystalline polyester layer, and another polyester layer are laminated in this order.