JP5837411B2 - Polyester film for in-mold transfer - Google Patents

Description

  The present invention relates to a polyester film for in-mold transfer, and more particularly to a film useful as a support film for a transfer foil for in-mold transfer that is transferred and printed simultaneously with molding in injection molding or the like.

Conventionally, as a transfer foil for in-mold molding transfer (hereinafter sometimes referred to as in-mold molding transfer foil), a polyester film such as a polyethylene terephthalate film is used as a base film, and a release layer (hereinafter, referred to as a release film) A laminated film in which a printing layer is coated thereon is used.
This in-mold molding transfer foil is transferred to a molded product using an in-mold molding method, and then peeled and separated between the release layer surface and the printing layer surface. That is, after molding transfer, the printed layer is adhered to the surface of the molded product and taken out as a product, and the release layer is removed after molding in a state of being laminated on the base film.

In-mold molded transfer foil is opposite to the release layer of the base film, as it may cause productivity drop due to sticking of transfer foils due to electrification and adhesion of dust and dirt to the transfer foil surface during handling. Attempts have been made to provide an antistatic layer on the surface or to use a release agent in the antistatic layer (Patent Document 1).
In addition, the conventional in-mold molding transfer foil used a flat base film in order to obtain a clear molded product appearance. However, in recent years, the in-mold transfer method has been applied to the surface appearance of a molded product having a matte appearance. Attempts to use and grant are being made. Accordingly, there has been a demand for a base film that has excellent matte appearance transferability and has moldability with respect to the transfer foil base film.
As a method for obtaining a matte appearance, for example, in Patent Document 2, the glossiness Gs (60 °) is 10 to 45% on one side of the film, and the film strength when stretched at 150 ° C. and 100% is 0.5 to 3%. A matte laminated polyester film for molding of 0.0 kg / mm ² has been proposed, and as a method for solving the problem that the moldability of the film deteriorates as the matte effect increases, a composite in which two or more layers are laminated by a coextrusion method A configuration in which one layer of the film is a matte layer has been proposed. On the other hand, a film according to a specific example of Patent Document 2 has a film glossiness of about 28 to 30, and a transfer film capable of transferring with a high matte property is demanded.

Patent Document 3 discloses a biaxially stretched coextruded matte polyester film having good matting properties and transparency, and 1 to 10 weights of particles having a particle size of 2 to 5 μm on one side of the laminated film. Although the film glossiness (G ₆₀ ) specifically exemplified is about 50 to 70, it has not been studied for use in molding processing, and the antistatic performance at that time is disclosed. Has not been studied.
Patent Document 4 exemplifies a base film having a Ra of 20 to 50 nm as a base film for matte in-mold transfer, but the exemplified film glossiness (G ₆₀ ) is 140 to 160.

Thus, although matte films and matte in-mold transfer base films have been studied in the past, the matte appearance with a matte glossiness of 40 or less than the conventional matte appearance can be imparted to the surface appearance of molded products. Currently, no mold transfer foil has been obtained.
At the same time, there is no printing omission when giving a matte matte appearance more than before, and it is also an antistatic performance during the process from creation of in-mold transfer foil to molding while being a matte transfer film At present, an excellent in-mold transfer foil has not yet been obtained.

JP 2006-187951 A Japanese Patent Laid-Open No. 04-110147 JP 2002-200723 A JP 2007-268708 A

  An object of the present invention is to provide a matte appearance on the surface of a molded product that is further superior to that of the prior art, has excellent printability, and has sufficient moldability for an in-mold transfer foil. An object of the present invention is to provide a polyester film for in-mold transfer that is excellent in antistatic performance from the preparation process to the molding process.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have formed a matte appearance that is more matte than in the past by in-mold transfer when a matte appearance is imparted to a molded product using the in-mold transfer method. If the particle size in the transfer foil film is increased or the particle content is increased to be applied to the surface of the product, this will cause printing omission when forming the printing layer, and the effect of roughening the surface of the matte layer. It was found that the antistatic performance of the antistatic layer was affected, and the present invention was completed by paying attention to the maximum particle diameter of the particles used for the matte layer and the surface shape of the layer in contact with the antistatic layer. is there.

That is, an object of the present invention is to provide a polyester film including three layers in which a mat layer, a base material layer, and an antistatic layer are laminated in this order, and the gloss level (G ₆₀ ) on the mat surface side of the mat layer is 5 The matte layer has a mean particle size of 2.5 μm or more and 5.5 μm or less, and a maximum particle size of 16 μm or less in the range of 5% by weight or more and 25% by weight or less based on the weight of the layer. The base layer does not contain particles, or the content of the particles is more than 0% by weight and not more than 3.0% by weight based on the weight of the base layer, and the surface on the antistatic layer side This is achieved by an in-mold transfer polyester film having a resistance of 1 × 10 ¹¹ Ω / □ or less.

The polyester film for in-mold transfer of the present invention, as a preferred embodiment, in the range the intrinsic viscosity (eta) is less 0.50 dl / g or more 0.70 dl / g of Po Li ester film, contained in the matte layer The particles to be changed have a weight change at 300 ° C. by the TG-DTA method of 0% to 3.0%, and the particles contained in the matte layer are either amorphous silica or synthetic zeolite, The content of the release component in the antistatic layer is 1% by weight or more and 50% by weight or less based on the weight of the antistatic layer, and further comprises an easy-adhesion layer on the matte surface side, process material Also included are those provided with at least one of being used for applications.

  The polyester film for in-mold transfer of the present invention can give a matte appearance on the surface of the molded product even better than conventional when used as a transfer foil due to the surface shape and laminated structure of the matte layer, and also has good printability. In-mold suitable for matte transfer because it has excellent moldability for in-mold transfer foil and has excellent antistatic performance from the process of forming the in-mold transfer foil to the molding process. A transfer foil can be provided.

The present invention will be described in detail below.
<Polyester film>
The polyester film for in-mold transfer of the present invention is a polyester film including three layers in which a matte layer, a base material layer, and an antistatic layer are laminated in this order. Hereinafter, the polyester and each layer constituting the base material layer and the matte layer will be described.

(polyester)
In the present invention, the base material layer and the matte layer are made of polyester, and such polyester is a crystalline material synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Linear saturated polyester. Specific examples of the polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), and polyethylene-2,6-naphthalenedicarboxylate.

  The polyester may be a copolymer having one of these polyesters as a main component, or may be a blend. Here, the “main component” is 80 mol% or more based on the number of moles of the repeating unit of the polyester. The ratio of the main component is preferably 85 mol% or more, more preferably 90 mol% or more. Further, the subordinate component is 20 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, based on the number of moles of the repeating unit of the polyester. Among these polyesters, polyethylene terephthalate and polyethylene-2,6-naphthalene dicarboxylate are preferable, and polyethylene terephthalate is particularly preferable because of a good balance between mechanical properties and moldability.

(Matte layer)
The polyester film for in-mold transfer of the present invention has a matte layer on one side of the base material layer, and the matte surface of the matte layer opposite to the base material layer (hereinafter referred to as the gloss of the matte layer). The glossiness (G ₆₀ ) of the matte surface or the matte layer surface may be 5 or more and 25 or less. Here, the glossiness of the present invention is defined by values measured at 60 ° for both the incident angle and the light receiving angle in accordance with JIS standard Z8741. When the polyester film of the present invention has the matte layer having the glossiness, a matte surface appearance having a low glossiness can be imparted to the surface of the molded article by the in-mold transfer method.

The lower limit of the glossiness is preferably 7, and more preferably 9. The upper limit of glossiness is preferably 23, and more preferably 22. If the gloss level is to be lowered from the lower limit, the film formation and in-mold moldability are not sufficient due to excessive particles, and it is technically difficult to reduce the gloss level to such a range. . When the glossiness exceeds the upper limit, it is difficult to form a surface appearance having a glossiness of 30 or less on the surface of the molded product.
The matte layer is composed of the above-mentioned polyester, and in order to obtain the glossiness of the present invention, particles having an average particle size of 2.5 μm or more and 5.5 μm or less in the matte layer are based on the weight of the matte layer. It is necessary to contain in the range of 5 wt% or more and 25 wt% or less. At the same time, the maximum particle size of the particles contained in the matte layer needs to be 16 μm or less.

When the content of the particles is less than the lower limit, it is not possible to give a sufficiently matte appearance to the surface of the molded product. On the other hand, when the content of the particles exceeds the upper limit value, the film-forming property is remarkably deteriorated and tearing easily occurs, and the film formation itself becomes difficult. The content of the particles is preferably 5% by weight or more and 20% by weight or less, more preferably 10% by weight or more and 20% by weight or less.
The average particle size of the particles is preferably 3.0 μm or more and 5.5 μm or less, more preferably 3.0 μm or more and 5.3 μm or less. When the average particle diameter of the particles is less than the lower limit, the effect of lowering the glossiness is lowered, and if the amount of particles added is further increased to lower the glossiness, sufficient moldability cannot be obtained. Further, when the average particle diameter of the particles exceeds the upper limit value, printing omission occurs on the surface of the molded product.

The maximum particle diameter of the particles is preferably 15 μm or less, more preferably 12 μm or less. The maximum particle size in the present invention is represented by the particle size (d ₉₈ ) at 98% of the cumulative particle size distribution curve.
When the maximum particle diameter of the particles exceeds the upper limit, printing omission occurs on the surface of the molded product, and printability is deteriorated. In order for the maximum particle diameter of the particles to fall within such a range, it is necessary that the average particle diameter of the particles does not exceed the upper limit of the present invention.

The 10-point average roughness Rz of the matte layer surface of the present invention is preferably 5000 nm or more and 8000 nm or less, more preferably 5000 nm or more and 7800 nm or less, and further preferably 5200 nm or more and 7800 nm or less.
When the 10-point average roughness Rz on the surface of the matte layer is within such a range, it is possible to eliminate printing omission while improving the matte appearance of the molded product after transfer. When the 10-point average roughness Rz on the surface of the matte layer is less than the lower limit value, it may not be possible to impart a sufficient matte appearance to the surface of the molded product. Further, when the 10-point average roughness Rz on the surface of the matte layer exceeds the upper limit value, although the matte appearance is good, the surface irregularities are too severe, so that problems such as printing omission may occur. .
The 10-point average roughness Rz on the matte layer surface can be obtained by using particles having the above average particle size and maximum particle size within the above range.
Moreover, it is preferable that the thickness of a matte layer is 3-10 micrometers.

The particles used in the matte layer preferably have a change in weight at 300 ° C. by the TG-DTA method of 0% to 3.0%, and more preferably 1.5% to 3.0%. Is preferred. Specifically, the high temperature weight change of the particles is measured by measuring the weight change at 300 ° C. when the temperature is increased from 30 ° C. to 500 ° C. at a temperature increase rate of 10 ° C./min by a TG-DTA apparatus.
If the change in weight exceeds the upper limit, foaming may be caused in the polyester film production process or molding process, or the molecular weight may be lowered, and the film formability and moldability of the film may be lowered, especially in a large amount of particles. When it is contained, the film forming property and molding processability of the film may be remarkably lowered.

  The particle type may be either inorganic particles or organic particles, amorphous silica (colloidal silica), silica, talc, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, phosphorus Examples include magnesium acid, alumina, carbon black, titanium dioxide, kaolin, synthetic zeolite, crosslinked polystyrene particles, and crosslinked acrylate particles. Among these particles, at least one of amorphous silica and synthetic zeolite is more preferable, and any one of them may be used or used in combination. Moreover, you may use the mixture of the particle | grains from which the particle size differs in the same kind.

In addition, in the case of amorphous silica, a surface treated with a silane coupling agent is preferable in order to reduce moisture adsorption.
Particularly preferred particles are synthetic zeolite, and in order to reduce the adsorptivity of the synthetic zeolite, in particular the moisture adsorptivity, those having an acid treatment to such an extent that the particle shape is not destroyed with an acid having a pH of 5 or more are preferred. What was heat-processed at the above temperature is preferable.

The shape of the particle is not particularly defined, but if it is indefinite, the particle size distribution is widened, and coarse protrusions due to aggregation are likely to occur, and printing omission may occur. Therefore, the shape of the particles is preferably spherical or multifaceted. Examples of preferable particles include spherical or multi-faceted synthetic zeolite. In the case of multi-faceted particles, a matte effect is easily obtained. Among the polyhedral particles, cubic particles are particularly preferable.
The method of adding these particles is not particularly limited, and examples thereof include a method of adding to a glycol dispersion during polycondensation of polyester, or a method of adding to a matte layer via a master batch during extrusion.

(Base material layer)
The polyester film for in-mold transfer of the present invention has a base material layer between the matte layer and the antistatic layer. By having the base material layer, sufficient in-mold moldability can be obtained, and the surface resistance characteristics of the antistatic layer provided on the base material layer can be enhanced. If the base layer is not provided, a matte layer and an antistatic layer containing a large amount of particles alone cannot provide sufficient in-mold moldability, and an antistatic layer is directly provided on the rough surface of the matte layer. In addition, since the antistatic layer is not flat, it is difficult to obtain sufficient antistatic properties.

The base material layer is made of polyester, and the base material layer does not contain particles, or the content of the particles is more than 0% by weight and not more than 3.0% by weight based on the weight of the base material layer. . When the particles are included, the concentration of the particles in the base material layer is more preferably 2.5% by weight or less, and further preferably 2.0% by weight or less.
When the content of particles in the base material layer exceeds the upper limit value, in-mold moldability and surface resistance characteristics of the antistatic layer may be deteriorated.

  The kind of particle | grains used for a base material layer will not be specifically limited if it is a particle normally added to a film, Any of an inorganic particle and an organic particle may be sufficient. Specifically, amorphous silica (colloidal silica), silica, talc, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, alumina, carbon black, titanium dioxide, kaolin Synthetic zeolite, crosslinked polystyrene particles, crosslinked acrylate particles, and the like. One kind of these particles, or two or more kinds of different particles may be contained, or a mixture of particles of the same kind and different particle sizes may be used.

For the base material layer, other resins than the polyester, colorant, antistatic agent, stabilizer, antioxidant, ultraviolet absorber, fluorescent whitening agent, etc. are required as long as the object of the present invention is not impaired. It can be contained accordingly.
The thickness of the base material layer is preferably 40 μm to 50 μm.

(Antistatic layer)
The polyester film for in-mold transfer of the present invention has an antistatic layer on one side of the base material layer, and the surface resistance of the antistatic layer is required to be 1 × 10 ¹¹ Ω / □ or less. It is preferably ¹⁰ Ω / □ or less.
By having such an antistatic layer, sticking of the transfer foils due to charging and adhesion of dust and dirt to the transfer foil surface during handling of the in-mold transfer foil are suppressed.
Here, the surface resistance means a surface specific resistance value (Ω / □) after 1 minute at an applied voltage of 100 V under a measurement temperature of 23 ° C. and a measurement humidity of 60% using a specific resistance measuring instrument.

In order to obtain such antistatic performance, in addition to using a predetermined amount of an antistatic agent in the antistatic layer, a certain level of flatness is required on the surface of the base material layer on which the antistatic layer is provided. In the case of containing no particles or particles, the content is in the range of 3.0% by weight or less.
The antistatic layer preferably contains an antistatic component and a release component. By including an antistatic component, excellent surface resistance characteristics can be obtained, and sticking of transfer foils due to charging and adhesion of dust and dirt to the transfer foil surface during handling of the transfer foil for in-mold can be suppressed. Moreover, blocking, such as sticking of films, can be prevented by including a mold release component.

(Release component)
The release component contained in the antistatic layer is preferably of a type that does not transfer to the back surface of the film, and examples include silicone having a reactive group and silicone having a hydrocarbon group having 6 or more carbon atoms. By using such silicone as a mold release component, transfer to the back of the film does not occur, and transfer defects to the molded product of the printed layer are less likely to occur.
The silicone having a reactive group preferably has a reactive group directly bonded to a silicon atom, an organic group containing an amino group, an organic group containing an epoxy group, an organic group containing a carboxylic acid group, a silanol group or silanol by hydrolysis. 1 or more types of reactive groups chosen from the organic group which produces | generates group are contained.

The silicone having this reactive group may be a mixture of silicones having different types of reactive groups. The silicone having such a reactive group preferably has a molecular weight of 1,000 to 500,000. If it is less than 1000, it may be easy to transfer to the back surface, and if it exceeds 500,000, the viscosity becomes high and handling may be difficult.
Examples of the silicone having a hydrocarbon group having 6 or more carbon atoms include alkyl-modified silicones having 6 or more carbon atoms, aralkyl-modified silicones having 6 or more carbon atoms, alkylaralkyl co-modified silicones having 6 or more carbon atoms, and aryl-modified silicones.

In addition to the silicone component, the release component may be used as a subordinate component which is usually used as a release agent such as wax. However, the release agent other than silicone is used in a range less than the silicone component. Used within a range that does not impair the purpose.
Such a release component is preferably contained in the range of 1 wt% to 50 wt% based on the weight of the antistatic layer. Further, the lower limit value of the content of mold release is more preferably 5% by weight, still more preferably 7% by weight, and the upper limit value of the content of mold release is more preferably 40% by weight, still more preferably 30%. % By weight, particularly preferably 20% by weight, most preferably 15% by weight. If the content of the release component is less than the lower limit, sticking with the printed layer may occur. On the other hand, if the content exceeds the upper limit, the coating film uniformity may be reduced.

(Antistatic component)
The antistatic layer preferably contains a cationic polymer as an antistatic component. Examples of the cationic polymer include cationic polymers containing the following monomer component (a), non-reactive monomer component (b), and reactive monomer component (c).

（式（１）中、Ｒ^１、Ｒ^２はそれぞれＨまたはＣＨ_３、Ｒ^３は炭素数が２〜１０のアルキレン基、Ｒ^４、Ｒ^５はそれぞれ炭素数が１〜５の飽和炭化水素基、Ｒ^６はＨまたは炭素数が２〜１０のヒドロキシアルキレン基、Ｙ⁻はハロゲンイオン、ナイトレートイオン、サルフェートイオン、アルキルサルフェートイオン、スルホネートイオン又はアルキルスルホネートイオンである。） Examples of the monomer component (a) constituting the cationic polymer include a monomer component (a) represented by the following formula (1).

(In the formula (1), R ¹ and R ² are each H or CH ₃ , R ³ is an alkylene group having 2 to 10 carbon atoms, and R ⁴ and R ⁵ are each a saturated hydrocarbon group having 1 to 5 carbon atoms. , R ⁶ is H or a hydroxyalkylene group having 2 to 10 carbon atoms, Y ⁻ is a halogen ion, nitrate ion, sulfate ion, alkyl sulfate ion, sulfonate ion or alkyl sulfonate ion.

  The monomer component (a) is preferably used in the range of 30 to 90 mol% per cationic polymer. If the ratio of the monomer component (a) is less than the lower limit value, a sufficient surface resistance value may not be obtained. On the other hand, when the proportion of the monomer component (a) exceeds the upper limit, the water resistance of the coating film is lowered, and the antistatic property after washing with water may be lowered.

As the non-reactive monomer component (b) constituting the cationic polymer, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t- Butyl group, 2-ethylhexyl group, cyclohexyl group, etc.), styrene, and α-methylstyrene.
The non-reactive monomer component (b) is preferably used in the range of 10 to 69 mol% per cationic polymer. If the proportion of the non-reactive monomer component (b) is less than the lower limit, the adhesion with the base material layer and the cohesiveness of the coating film may be lowered. On the other hand, when the proportion of the non-reactive monomer component (b) exceeds the upper limit value, the antistatic property may be lowered.

  Examples of the reactive monomer component (c) constituting the cationic polymer include hydroxy-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate; glycidyl acrylate, glycidyl methacrylate, Epoxy group-containing monomers such as allyl glycidyl ether; acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.) ) Or other salt-containing monomers; acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamido N, N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.), N-alkoxyacrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide, N, N-dialkoxymethacrylamide (alkoxy groups include methoxy, ethoxy, butoxy, isobutoxy, etc.), acryloylmorpholine, Monomers containing amide groups such as N-methylolacrylamide, N-methylolmethacrylamide, N-phenylacrylamide, N-phenylmethacrylamide; monomers of acid anhydrides such as maleic anhydride and itaconic anhydride; vinyl isocyanate, allyl It can be exemplified isocyanate-containing monomers such as isocyanate.

Such reactive monomer component (c) is preferably used in the range of 1 to 40 mol% per cationic polymer. If the ratio of the reactive monomer component (c) is less than the lower limit, the water-resistant antistatic property is lowered, and the antistatic property after washing with water may be lowered. On the other hand, when the ratio of the reactive monomer component (c) exceeds the upper limit, the number of crosslinking points increases and the film-forming property of the coating film may be lowered.
The antistatic component is preferably contained in the range of 50% by weight to 99% by weight based on the weight of the antistatic layer.

(Crosslinking agent)
It is preferable to further add a crosslinking agent to the antistatic layer in order to improve the cohesive strength of the coating film and to suppress the precipitation oligomer during heating. Examples of the crosslinking agent include epoxy compounds, oxazoline compounds, melamine compounds, and isocyanate compounds, and other coupling agents can also be used. Epoxy compounds and oxazoline compounds are preferably used because of easy handling and the pot life of the coating liquid, and a coupling agent is also preferably used.

More specific examples of the crosslinking agent include the following.
Examples of the epoxy compound include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like.
As the oxazoline compound, a polymer containing an oxazoline group is preferable. It can be prepared by polymerization with addition polymerizable oxazoline group-containing monomers alone or with other monomers. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. The other monomer is not particularly limited as long as it is a monomer copolymerizable with an addition polymerizable oxazoline group-containing monomer.

  The melamine compound is preferably a compound obtained by reacting methylol melamine derivative obtained by condensing melamine and formaldehyde with ether such as methyl alcohol, ethyl alcohol or isopropyl alcohol as a lower alcohol and a mixture thereof. Examples of the methylol melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine and the like.

  Isocyanate compounds include, for example, tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, metaxylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, an adduct of tolylene diisocyanate and hexane triol, Tolylene diisocyanate and trimethylolpropane adduct, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-vitrylene- 4,4 'diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate and the like.

Coupling agents such as silane coupling agents and the like, a compound represented by the general formula YRSiX _3. Here, Y is an organic functional group such as vinyl group, epoxy group, amino group, and mercapto group, R is an alkylene group such as methylene, ethylene, and propylene group, and X is a hydrolyzable group such as methoxy group and ethoxy group, and an alkyl group. It is particularly preferred that the Y moiety is an epoxy group. Preferred silane coupling agents are γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.
As a coupling agent other than the silane coupling agent, an organometallic compound containing a metal such as zirconium, titanium, or aluminum can be used.

When a crosslinking agent is used, the addition amount of the crosslinking agent is preferably 5 to 30% by weight based on the weight of the antistatic layer. If the addition amount of the crosslinking agent is less than the lower limit, the cohesive force of the coating layer may be lowered and durability may be lowered. On the other hand, when the addition amount of the crosslinking agent exceeds the upper limit value, the film forming property of the coating layer may be deteriorated and the coating appearance may be deteriorated.
The antistatic layer is preferably provided on one surface of the base material layer on the surface opposite to the matte layer by coating. The thickness of the antistatic layer is preferably 0.01 to 0.1 [mu] m, more preferably 0.01 to 0.06 [mu] m, as the thickness after drying. If the thickness of the antistatic layer is less than the lower limit, the antistatic property may be insufficient, and if the thickness exceeds the upper limit, the transfer foils may be easily blocked.

(Easily adhesive layer)
The polyester film for in-mold transfer of the present invention preferably further has an easy-adhesion layer on the matte surface side for the purpose of improving the adhesion to the release layer (medium layer). The easy adhesion layer is preferably an easy adhesion coating layer provided by coating. For the easy adhesion layer, it is preferable to use a copolymerized polyester in order to obtain high adhesion to a release layer provided when used as an in-mold transfer foil.

(Copolymerized polyester)
The copolymer polyester constituting the easy-adhesion layer preferably has a secondary transition point (Tg) of 40 ° C or higher and 85 ° C or lower, more preferably 45 ° C or higher and 80 ° C or lower. When the Tg of the copolyester is less than the lower limit, the heat resistance of the easy-adhesion layer may not be sufficient, and the blocking resistance may not be sufficient. On the other hand, if the Tg of the copolyester exceeds the upper limit, the adhesion between the polyester film and the release layer may not be sufficient.

Further, this copolymer polyester is a linear polyester comprising a dicarboxylic acid component and a polyol component, and a copolymer of a dicarboxylic acid component having a metal base in a range of 9 mol% to 15 mol% based on the total acid component of the copolymer polyester. Preferably there is. When the copolymerization ratio of the dicarboxylic acid component having a metal base is less than the lower limit, the solvent resistance of the easy adhesion layer may not be sufficiently improved, and on the other hand, when the upper limit is exceeded, the release layer and the easy adhesion layer Adhesiveness may be reduced.
The dicarboxylic acid having a metal base is preferably one having a functional group such as SO ₃ M group or COOM group (M is Na, K, Li, NH _4, etc.) in the acid compound. Those having a metal base are preferred.

Examples of the dicarboxylic acid component other than the dicarboxylic acid component having a metal base that forms the copolymer polyester of the present invention include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and adipine Examples thereof include acid, sebacic acid, phenylindanedicarboxylic acid, and dimer acid. Two or more of these components can be used.
Further, together with these components, a small amount of unsaturated polybasic acid or hydroxycarboxylic acid can be used, and it is preferably used in a range of 10 mol% or less based on the total acid components constituting the copolyester, and 5 mol%. More preferably, it is used in the following.

Moreover, as a polyol component which forms copolyester, ethylene glycol, the alkylene oxide addition product of bisphenol A, and 1, 4- butanediol are preferable, and in order to make a secondary transition point into this range, using 2 or more types preferable.
As the copolyester resin, a modified polyester copolymer, for example, a block polymer obtained by modifying the polyester copolymer with an acrylic, polyurethane, silicone, epoxy, phenol resin, or the like, or a graft polymer can also be used.

The content of the copolyester is preferably 65% by weight or more and 98% by weight or less, and more preferably 70% by weight or more and 95% by weight or less based on the weight of the easy-adhesion layer.
When the content of the copolyester is less than 65% by weight, the adhesion between the release layer and the easy adhesion layer may be lowered. Moreover, when content of copolymerized polyester exceeds 98 weight%, although solvent resistance improves by the dicarboxylic acid component which has a metal base relatively increasing, adhesiveness may fall.

(Crosslinking agent)
It is preferable to add a crosslinking agent similar to the above-described antistatic layer to the easy adhesion layer. Among them, an acrylic copolymer having an oxazoline group is particularly preferable.

(Other additives)
Particles and surfactants may be added to the easy adhesion layer as other additives. Known particles can be used as the particles, and silicon oxide, aluminum oxide, crosslinked polystyrene resin particles, and crosslinked acrylic resin particles are particularly preferable. Moreover, you may use a small amount of acrylic copolymers with the said copolyester as a binder component in the easily adhesive layer in the range which does not impair the subject of this invention.

(Film characteristics)
<Intrinsic viscosity>
The intrinsic viscosity (η) of the polyester film is preferably in the range of 0.50 dl / g or more and 0.70 dl / g or less. Such intrinsic viscosity is represented by a measured value in an o-chlorophenol solution at 35 ° C. The lower limit of the intrinsic viscosity of the film is preferably 0.52 dl / g. The upper limit of the intrinsic viscosity of the film is preferably 0.65 dl / g, more preferably 0.60 dl / g. When the intrinsic viscosity of the film is less than the lower limit value, the film is easily broken during in-mold molding. On the other hand, when the intrinsic viscosity of the film exceeds the upper limit, the viscosity becomes too high, the load in the film production process increases, and the productivity decreases.

<Film thickness>
The polyester film of this invention should just have the thickness used as a film for in-mold transfer foil, Preferably it is 10-150 micrometers, More preferably, it is 20-100 micrometers, Most preferably, it is 45-70 micrometers.
In the polyester film of the present invention, dF10 / dS is preferably 0.10 Kg / mm ² / elongation% or more and 0.30 Kg / mm ² / elongation% or less, preferably 0.15 Kg / mm ² / elongation%. As mentioned above, it is further more preferable that it is below 0.25 kg / mm < ² > / elongation%. Here, dF10 / dS is a curve gradient at 10% elongation in the film unloading curve. When this dF10 / dS exceeds the upper limit value, the stress at the time of molding becomes high, which may cause troubles such as tearing. On the other hand, if this dF10 / dS is less than the lower limit, the surface properties, heat resistance, and dimensional stability of the film may deteriorate.
The polyester film having such dF10 / dS characteristics can be produced by the stretching temperature, the draw ratio and the heat setting treatment described in the production method.

(Film production method)
The polyester film of the present invention can be produced, for example, by the following method. That is, the matte layer and the base material layer are laminated and extruded by a co-extrusion method, cooled and solidified with a casting drum to form an amorphous unstretched film, and then the machine direction (hereinafter, machine axis direction, continuous film forming direction, longitudinal direction or MD direction). And the transverse direction (hereinafter, sometimes referred to as the width direction and the TD direction).
Stretching in the machine direction is, for example, drawn at a temperature of 60 to 130 ° C., preferably 90 to 125 ° C., in the machine direction of 2.0 to 4.0 times, preferably 2.5 to 3.5 times. Stretching in the transverse direction is, for example, stretched at a temperature of 60 to 130 ° C., preferably 90 to 125 ° C., 2.0 to 4.0 times, preferably 3.0 to 4.0 times. In addition, it is preferable that the area magnification after biaxial stretching is 13 or less. Moreover, although the method of extending | stretching in one direction can also be used by the multistage of 2 steps | paragraphs or more, it is preferable that the final draw ratio exists in the above-mentioned range.

In addition, it is preferable to perform a heat setting process after extending | stretching a film. The heat setting treatment is preferably performed for 1 to 30 seconds in a temperature range higher than the final stretching temperature and lower than the melting point. For example, in the case of a polyethylene terephthalate film, it is preferable to select and heat-set at a temperature of 150 to 250 ° C. and a time of 2 to 30 seconds. At that time, it may be performed under a limited contraction or expansion within 20%, or under a constant length, or may be performed in two or more stages.
The antistatic layer is provided by applying a coating agent containing a component for forming the antistatic layer on the surface of the base material layer opposite to the matte layer. A polyester film before completion of crystal orientation is preferred as a film at the time of application. In this case, it is preferable to perform a stretching process for completing the crystal orientation on the film after the coating, and further a heat setting process.

Moreover, when providing an easily bonding layer, it is preferable to apply | coat the coating agent containing the formation component of an easily bonding layer on the matte layer of a polyester film, and it is preferable to also provide an easily bonding layer when providing an antistatic layer.
As the polyester film before the completion of the crystal orientation, an unstretched film obtained by directly melting the polyester into a film, a uniaxially stretched film obtained by stretching the unstretched film in either the longitudinal direction or the transverse direction, A film stretched at a low magnification in two directions of the machine direction and the transverse direction (a biaxially stretched film before the orientation crystallization is completed by finally re-stretching in the machine direction or the transverse direction) can be exemplified.
Any coating method can be applied as a method of applying the coating agent to the polyester film. For example, a roll coating method, a gravure coating method, a micro gravure coating method, a reverse coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, and a curtain coating method may be applied alone or in combination.

  In order to form the antistatic layer and the easy-adhesion layer, the coating material in the present invention is preferably in the form of a water-soluble liquid, an aqueous dispersion, an emulsion, or the like, that is, an aqueous coating, but the organic solvent is a solvent. It is also possible. The aqueous coating material may contain a slight amount of an organic solvent for the purpose of assisting the stability of the coating material or the coating property of the coating material. Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexanone, n-hexane, toluene, xylene, methanol, ethanol, n-propanol and isopropanol. These can be used alone or in combination of two or more.

In the coating composition of the present invention, particularly an aqueous liquid, a surfactant can be combined in order to improve the wettability to the polyester film as long as the object of the present invention is not impaired. Such surfactants are known surfactants, for example, nonionic surfactants such as alkylene oxide polymers, cationic compounds such as compounds having quaternary ammonium salts, compounds having alkylpyridinium salts, compounds having sulfonates, etc. Alternatively, an anionic surfactant can be used. When a surfactant is added, the surface tension of the coating agent is preferably 50 dyne / cm or less, preferably 40 dyne / cm or less.
The solid content concentration of the coating is usually preferably 0.5 to 30% by weight based on the weight of the coating. Such a solid content composition matches the respective compositions of the antistatic layer and the easy-adhesion layer formed on the polyester film.

The coating amount of the coating agent is preferably 3 to 50 g, more preferably 5 to 40 g per 1 m ² of the running film. The thickness of the coating film (easily adhesive layer) finally obtained by drying is preferably 0.01 to 0.3 μm, more preferably 0.02 to 0.2 μm. When the thickness of the coating film is less than 0.01 μm, the adhesiveness may be insufficient, and when it exceeds 0.3 μm, blocking may easily occur. A uniform coating film is obtained by drying after application.
In this invention, after apply | coating a coating agent to a polyester film, drying, Preferably a extending process is performed, It is preferable to perform this drying at 90-130 degreeC for 2 to 20 seconds. This drying can also serve as a pre-heat treatment for the stretching treatment or a heat treatment during stretching.

(In-mold transfer foil)
The polyester film containing three layers of the matte layer, base material layer, and antistatic layer laminated in this order is used for in-mold transfer applications, giving the molded product surface an even better matte appearance In addition, it has excellent printability, has sufficient moldability for in-mold transfer foil, and has excellent antistatic performance and anti-blocking performance from the in-mold transfer foil creation process to molding processing. Is.
Specifically, by using the polyester film of the present invention as a transfer foil and performing in-mold transfer, a matte appearance having a glossiness of 30 or less can be imparted to the surface of the molded product.

  The polyester film for in-mold transfer of the present invention preferably further has an easy adhesion layer on the matte surface side, and is used in a form in which a release layer (medium layer) and a printing layer are further formed on the easy adhesion layer. These laminated films can be used as an in-mold transfer foil. When performing in-mold molding, place the printed layer in the mold so that it comes into contact with the surface of the molded product, perform in-mold molding by a commonly used method, and after the printed layer is molded and transferred, the printed layer adheres to the molded product surface. Then, the product is taken out as a product, and the other part is used in a form removed from the product, and is suitably used as a process material for producing a molded product by in-mold transfer.

  Hereinafter, the present invention will be further described with reference to examples. In addition, the characteristic in an example was calculated | required with the following method.

1. Gloss (G ₆₀₎
Based on JIS standard (Z8741), it measured using the gloss meter "VGS-SENSOR" by Nippon Denshoku Industries Co., Ltd. The incident angle and the light receiving angle were measured in increments of N = 5 at 60 °, and the average value was used. Further, the matte property was judged according to the following criteria.
◎: 5 or more and 18 or less ・ ・ ・ Excellent mattness ○: More than 18 and 25 or less ・ ・ ・ Good mattness ×: More than 25 ・ ・ ・ Poor mattness

2. Average particle diameter, maximum particle diameter (d ₉₈ )
The particles were stirred with a mixer so as to have a concentration of 3% in ethylene glycol, and measured using a laser scattering particle size distribution analyzer SALD-7000 manufactured by Shimadzu Corporation. The 50% volume particle size (D50) was determined from the particle size distribution measurement result, and this was used as the average particle size.
The maximum particle size was a median particle diameter d _98. Note the value of d ₉₈ is the particle diameter at 98% cumulative particle size distribution curve.

3. Particle content Select a solvent that dissolves the polyester resin but does not dissolve the particles, dissolve the film sample, centrifuge the particles from the polyester resin, and then add the particle content to the total weight of the particles (% by weight). And

4). Antistatic property The surface resistivity of the antistatic layer surface of the sample film was measured by using a specific resistance measuring instrument manufactured by Takeda Riken Co., Ltd., at a measurement temperature of 23 ° C. and a measurement humidity of 60%, after 1 minute at an applied voltage of 100 V. The surface resistivity (Ω / □) was measured and judged according to the following criteria.
○: Less than 1 × 10 ¹¹ Ω / □ ··· Good antistatic property ×: More than 1 × 10 ¹¹ Ω / □… Poor antistatic property

5. Each layer thickness of the film A sample was cut into a triangle, fixed in an embedded capsule, and then embedded in an epoxy resin. Then, after embedding the sample with a microtome (ULTRACUT-S) into a thin film section having a thickness of 50 nm in parallel with the microtome, the specimen was observed and photographed with a transmission electron microscope at an acceleration voltage of 100 kv. The thickness of each layer was measured at 10 points, and the average thickness was determined for each layer. About the matte layer, it measured about the part which particle | grains do not exist.

6. 10-point average roughness Rz
In accordance with JIS-B0601, B0651, using a three-dimensional surface roughness meter (trade name: SURF CORDER SE-3CK, manufactured by Kosaka Laboratory Ltd.), stylus tip R2 μm, scanning pitch 2 μm, scanning length 1 mm, scanning The 10-point average roughness Rz was measured under the conditions of 100 pieces, a cutoff of 0.25 mm, and a magnification of 5000 times.

7). Weight change after heating of particles contained in matte layer TG-DTA apparatus (manufactured by SII, SSC5200 TG / DTA220), 300 when heated from 30 ° C to 500 ° C at a heating rate of 10 ° C / min It calculated | required from the weight reduction rate (%) of the particle | grains in ° C.

8). Intrinsic viscosity Intrinsic viscosity ([η]) (unit: dl / g) was measured with an o-chlorophenol solution at 35 ° C. The values listed in Table 2 are measured values for the film.

9. Moldability An in-mold transfer foil was placed on the mold so that the pattern layer (ink) side was the injection side, and a tray-shaped molded product with a size of 10 cm square, a rising edge of 15 mm, and a corner portion R of 2 mm was injection molded. . At this time, polycarbonate / ABS resin alloy was used as the molding resin, and the resin temperature was 260 ° C., the mold temperature was 50 ° C., and the resin pressure was about 350 MPa. From the tray-shaped molded product, the transfer foil was peeled off at the interface between the release layer and the pattern layer to obtain a decorated molded part.
The situation in this process was evaluated by the following indicators.
○: Film is not torn and no wrinkles ×: Film is torn or a large amount of wrinkles are generated

10. Matting property of molded product A molded part was obtained by the same method as the evaluation of moldability, and the result of the glossiness (G ₆₀ ) of the molded component was evaluated according to the following index.
○: 30 or less ... Good mattness of molded parts ×: More than 30 ... Poor mattness of molded parts

11. Printability A methyl ethyl ketone / toluene solution of melamine resin was applied on the matte layer of the film to form a release layer film having a thickness of 1 μm. Here, for the adjustment of the thickness of 1 μm, the solution concentration is adjusted to be 1 μm in thickness on a smooth polyethylene terephthalate film not containing particles, and after checking the thickness, it is applied to the matte layer side under the same conditions. Went in the way.
An ultraviolet curable hard coat layer (thickness 5 μm) containing urethane acrylate as a main component was printed on the entire surface by a gravure printing method, and further a pattern layer was printed by an acrylic resin ink on the entire surface by a gravure printing method. The results were evaluated according to the following criteria. In addition, when it had an easy-adhesion layer further on the matte layer, the film of the said release layer was formed on the easy-adhesion layer, and printability was evaluated.
○: Print appearance is good ×: Pattern layer is unclear (missing etc.)

12 Adhesive strength evaluation A melamine resin methylethylketone / toluene solution was applied on the matte layer of the film to form a 1 μm-thick release layer film, and a sample having a strip shape measuring 100 mm long by 20 mm wide was used as a tensile tester. After extending 50% in the longitudinal direction under a heating atmosphere at 160 ° C. using a slab, the cellophane tape (registered trademark manufactured by Nichiban Co., Ltd.) was applied on the release layer and left 10 times with the thumb. The cellophane tape was peeled off at a 90 ° peel angle, and then the cellophane tape peel test was performed to observe the surface state. The state of ○ satisfies practical performance. In addition, when it had an easily bonding layer, the melamine resin release layer was formed on the easily bonding layer.
○: No change △: Partial separation

13. Blocking resistance Antistatic surface using a stamping foil pigment foil (COLORIT) P type (manufactured by Kurz) to evaluate the blocking resistance between the antistatic layer surface of the sample film and the printed surface of the in-mold transfer foil. And the printing surface were combined, a temperature of 60 ° C. and a pressure of 1 kg / cm ² were added and the environment was maintained for 24 hours, and then the blocking state between the antistatic layer surface and the label sealing surface was observed and evaluated according to the following criteria.
○: No change △: Partial separation

[Examples 1-9, Comparative Examples 1-8]
Particles as shown in Table 1 are added to the matte layer (A) and the base material layer (B) in polyethylene terephthalate (intrinsic viscosity 0.63 dl / g), respectively, and supplied from an extruder heated to 280 ° C. A layer polymer and B layer polymer are combined using a two-layer feed block device that becomes A / B (however, in Comparative Example 1, a feed block that has three layers of A / B / A is used), While maintaining the laminated state, the sheet was melt-extruded from a die on a rotary cooling drum maintained at 20 ° C. to form an unstretched film, and then the unstretched film was stretched 3.4 times in the machine direction. The described coating layer components (easy adhesion layer: 4% by weight, antistatic layer 3% by weight) were each uniformly coated with a roll coater. The coated film was subsequently dried at 105 ° C., stretched 3.5 times in the transverse direction at 140 ° C., and heat-fixed at 230 ° C. to have a coated film shown in the table (thickness 50 μm). ) The evaluation results of each film are shown in Table 2.

The components used in Table 1 are as follows: Copolyester: Acid component is 50 mol% terephthalic acid / 45 mol% isophthalic acid / 5 mol% 5-sodium sulfoisophthalic acid, glycol component is 90 mol% ethylene glycol / It is comprised by 10 mol% of diethylene glycol (Tg = 40 degreeC). The polyester was produced as follows. That is, 30 parts of dimethyl terephthalate, 27 parts of dimethyl isophthalate, 5 parts of dimethyl 5-sodiumsulfoisophthalate, 36 parts of ethylene glycol and 3 parts of diethylene glycol were charged into the reactor, and 0.05 part of tetrabutoxy titanium was added thereto. Then, the temperature was controlled at 230 ° C. in a nitrogen atmosphere, and the produced methanol was distilled off to conduct a transesterification reaction. Subsequently, the temperature of the reaction system was gradually raised to 255 ° C., and the inside of the system was reduced to 1 mmHg to carry out a polycondensation reaction to obtain a copolyester. In addition, the manufacturing method of this copolyester is based on the method of Example 1 of Unexamined-Japanese-Patent No. 06-116487.

（上式（１）中、Ｒ^１、Ｒ^２はそれぞれＨであり、Ｒ^３は炭素数が３のアルキレン基であり、Ｒ^４、Ｒ^５はそれぞれ炭素数が１の飽和炭化水素基であり、Ｒ^６は炭素数が３のヒドロキシアルキレン基であり、Ｙ⁻はメチルスルホネートイオンである。） Cationic polymer: A copolymer having a structure represented by the following formula (1) consisting of 80 mol% / methyl acrylate 15 mol% / N-methylol acrylamide 5 mol%.

(In the above formula (1), R ¹ and R ² are each H, R ³ is an alkylene group having 3 carbon atoms, and R ⁴ and R ⁵ are each a saturated hydrocarbon group having 1 carbon atom. R ⁶ is a hydroxyalkylene group having 3 carbon atoms, and Y ⁻ is a methyl sulfonate ion.)

Release agent 1: Amino group-containing silicone (trade name TSF4700, manufactured by GE Toshiba Silicones Co., Ltd.)
Release agent 2: Polyethylene wax (trade name: Porolin L-618, manufactured by Chukyo Yushi Co., Ltd.)
Cross-linking agent: Oxazoline compound (trade name Epocros WS-700, manufactured by Nippon Shokubai Co., Ltd.)
Surfactant: Polyoxyethylene (n = 7) lauryl ether (trade name NAROACTY N-70, manufactured by Sanyo Chemical Co., Ltd.)

  The films of the examples can give the molded article a further matte appearance than before, have printability of the molded article and extremely excellent antistatic performance, anti-blocking performance, in-mold moldability In addition, an excellent matte in-mold transfer foil base film was obtained.

On the other hand, although the film of Comparative Example 1 was excellent in matte property, an antistatic layer was provided on the matte layer having a rough surface, and the antistatic property was not sufficient.
Further, the films of Comparative Examples 2 and 6 were not sufficiently matte, and the matte properties of the obtained molded products were not sufficient. Since Comparative Example 6 did not have an antistatic layer, antistatic properties and anti-blocking properties were not sufficient.

In the film of Comparative Example 3, since the particle concentration of the matte layer was too high, it was difficult to form a film due to tearing during film formation.
In Comparative Example 4, although the matte property of the film was good, the molded product transferred through the release layer was not sufficiently transferred to the matte surface of the film, and the molded product obtained The matte property was not sufficient.

The film of Comparative Example 5 had good matting properties and moldability, but the printability was insufficient because the maximum particle size of the matting layer was too large.
The films of Comparative Examples 7 and 8 had good matting properties, but contained many particles in the base material layer, and the antistatic property and moldability were not sufficient due to the surface roughness.

  The polyester film for in-mold transfer of the present invention can give a matte appearance on the surface of the molded product even better than conventional when used as a transfer foil due to the surface shape and laminated structure of the matte layer, and also has good printability. In-mold suitable for matte transfer because it has excellent moldability for in-mold transfer foil and has excellent antistatic performance from the process of forming the in-mold transfer foil to the molding process. A transfer foil can be provided.

Claims (7)

Matte layer, base layer, the polyester film comprising three layers formed by laminating the antistatic layer in this order, matte surface side of the glossiness of the matte layer (G ₆₀₎ is at 5 to 25, wherein The matte layer contains particles having an average particle size of 2.5 μm or more and 5.5 μm or less and a maximum particle size of 16 μm or less in a range of 5% by weight or more and 25% by weight or less based on the weight of the layer. Contains no particles, or the content of the particles is more than 0% by weight and not more than 3.0% by weight based on the weight of the base material layer, and the surface resistance on the antistatic layer side is 1 × 10 ¹¹ Ω / □ or less polyester film for in-mold transfer. The polyester film for in-mold transfer according to claim 1, wherein the intrinsic viscosity (η) of the polyester film is in the range of 0.50 dl / g or more and 0.70 dl / g or less. Particles contained in the matte layer have a weight change of 0% or more at 300 ° C. by the TG-DTA method.
. The polyester film for in-mold transfer according to claim 1 or 2 , wherein the polyester film is 0% or less. The polyester film for in-mold transfer according to any one of claims 1 to 3 , wherein the particles contained in the matte layer are either amorphous silica or synthetic zeolite. The polyester film for in-mold transfer according to any one of claims 1 to 4 , wherein the content of the release component in the antistatic layer is from 1% by weight to 50% by weight based on the weight of the antistatic layer. The polyester film for in-mold transfer according to any one of claims 1 to 5, further comprising an easy-adhesion layer on the matte surface side. The polyester film for in-mold transfer according to any one of claims 1 to 6 , which is used for a process material.