JP4401967B2 - In-mold transfer film - Google Patents

Description

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

  Conventionally, as a transfer foil for in-mold, a polyester film is used as a base film, a release layer (medium layer) is provided thereon, and a print layer is further coated on the release layer.

  This in-mold transfer foil is peeled and separated between the release layer surface and the print layer surface after molding and transfer. That is, after the 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 from the product while being provided on the base film.

  However, conventional transfer foils for in-mold often have insufficient adhesive force between the release layer and the base film or insufficient release properties between the release layer surface and the print layer surface. In the subsequent peeling treatment, peeling often occurs between the release layer surface and the base film surface, and the release layer remains on the surface of the molded product together with the printing layer. This problem is considered to be caused by peeling of the release layer and the base film due to distortion when the laminated film is deformed in in-mold transfer.

  In order to improve this point, it is effective to provide an adhesive layer between the base film and the release layer to improve the adhesion between the base film and the release layer. However, as the resin constituting the adhesive layer, a resin having low solvent resistance is used in order to obtain good adhesive properties. For this reason, when the release layer is applied, the adhesive layer dissolved or softened by the solvent is partially peeled off by the release layer coating tool, and the adhesive strength between the release layer and the base film decreases. A new problem arises. Moreover, the film which laminated | stacked the contact bonding layer has the problem that it is inferior to handling property at the time of providing a release layer on this film, in which films are easy to stick together and is inferior in blocking resistance.

  In recent years, in-mold transfer requires higher productivity, and attempts have been made to improve the molding speed. When handling the in-mold transfer foil, sticking of the transfer foils due to electrification and adhesion of dust and dust to the surface of the transfer foil may occur, which may reduce productivity. In addition, the mold is contaminated with oligomers generated from the polyester film during molding, and the mold is frequently washed, which causes a decrease in productivity.

  Usually, an antistatic agent is applied to the film surface to prevent dust and dirt from adhering to the film. However, a general antistatic agent is an ionic compound and is weak against water. Washing water is used to remove unnecessary materials in processes such as printing of in-mold transfer foil, and the antistatic layer is washed. There is a problem of elution with water.

JP-A-6-115295 JP 2004-223800 A JP 2004-174975 A JP 2004-58648 A

  The present invention aims to solve the problems of the prior art, has an excellent antistatic property during the process from the in-mold transfer foil preparation process to the molding transfer, and can greatly improve the productivity. In-mold transfer film useful as a base film for transfer foil for in-mold, which has no peeling between the release layer and the base film during in-mold transfer, and has excellent adhesion to the release layer during molding It is an issue to provide.

That is, the present invention relates to an easy-adhesion layer comprising a polyester film , an antistatic layer provided on one side and containing a cationic polymer , and a copolyester having a glass transition point of 40 to 85 ° C. provided on the other side. The cationic polymer is composed of a monomer component (a), a non-reactive monomer component (b), and a reactive monomer component (c) represented by the following formula, and the composition ratio of each component satisfies the following formula: It is the film for in-mold transfer characterized by these.
30 mol% ≦ a <79 mol%
20 mol% ≦ b <100− (a + c) mol%
1 mol% ≦ c ≦ 40 mol%

  According to the present invention, it has excellent antistatic properties from the process of creating a transfer foil for in-mold to molding and transfer, can significantly improve productivity, and a release layer at the time of in-mold transfer. There can be provided an in-mold transfer film useful as a base film for an in-mold transfer foil that has no peeling of the base film and has excellent adhesion to a release layer during molding.

Hereinafter, the present invention will be described in detail.
[Polyester film]
In the present invention, the polyester constituting the polyester film is a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of such polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), and polyethylene-2,6-naphthalate.

  The polyester may be a copolymer of these polyesters, and the polyester is the main component (for example, 80 mol% or more) and blended with other kinds of resins in a small proportion (for example, 20 mol% or less). It may be. Polyethylene terephthalate is particularly preferred as the polyester because it has a good balance between mechanical properties and moldability.

  The polyester film preferably contains substantially no lubricant fine particles. The lubricant fine particles referred to here are fine particles other than the fine particles inevitably contained at the time of polyester polymerization as fine particles caused by the catalyst, and mean fine particles added for the purpose of roughening the surface of the film. It is preferable that the polyester film contains substantially no fine lubricant particles because high-definition printing can be obtained by printing by in-mold molding. If the lubricant fine particles are present in the polyester film, the film surface roughness after biaxial film formation becomes rough and high-definition printing cannot be performed, which is not preferable.

Polyester film since it is possible to confirm the printing layer of the transfer foil for in-mold from the opposite side, it preferably has high transparency. In addition, a polyester film may contain a coloring agent, an antistatic agent, and antioxidant, for example.

  The polyester film can be produced, for example, by the following method. That is, polyester is melt-extruded into a film, cooled and solidified with a casting drum to form an amorphous unstretched film, and stretched in the machine and transverse directions. Stretching in the machine direction is, for example, at a temperature of 60 to 130 ° C., preferably 90 to 125 ° C., and stretched in the machine direction of, for example, 2.0 to 4.0 times, preferably 2.5 to 3.5 times. Stretching in the transverse direction is, for example, at a temperature of 60 to 130 ° C., preferably 90 to 125 ° C., and stretched in the transverse direction, for example, 2.0 to 4.0 times, preferably 3.0 to 4.0 times. The area ratio after biaxial stretching is preferably 13 or less.

  In addition, it is preferable to perform a heat setting process after extending | stretching a film. The heat setting treatment is preferably performed within a time period of 1 to 30 seconds within a temperature higher than the final stretching temperature and not higher 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 center line surface roughness of the surface of the polyester film is preferably 1 to 10 nm. By setting the center line surface roughness of the surface of the polyester film within this range, an in-mold transfer film having a center line average surface roughness of 1 to 10 nm on the surface of the coating layer can be obtained.

  The thickness of the polyester film is preferably 12 to 100 μm, and more preferably 25 to 75 μm, in order to obtain necessary strength from the viewpoints of handling properties, moldability and transparency when used as in-mold transfer.

[Antistatic layer]
In the present invention, the antistatic layer contains a cationic polymer. The cationic polymer contains a monomer component (a) represented by the following formula.

  Note that the saturated hydrocarbon group having 1 to 3 carbon atoms of R1 and R2 is a methyl group, an ethyl group, or a propyl group, and the alkylene group having 1 to 10 carbon atoms of R3 is, for example, an ethylene group, a trimethylene group, or a tetramethylene group. The saturated hydrocarbon group having 1 to 3 carbon atoms of R4 and R5 is a methyl group, an ethyl group, and a propyl group, and the hydroxyalkylene group having 2 to 4 carbon atoms of R6 is a hydroxyethylene group, a hydroxytrimethyl group; A methylene group and a hydroxytetramethylene group, and the saturated hydrocarbon group having 1 to 3 carbon atoms of R6 is a methyl group, an ethyl group, or a propyl group.

The monomer component (a) is preferably used in the range of 30 to 79 mol% per cationic polymer. If it is less than 30 mol%, the antistatic property becomes undesirably higher than 1 × 10 ¹³ Ω / □. If it exceeds 79 mol%, the water resistance of the coating film becomes poor and the antistatic property after washing with water is lowered, which is not preferable.

  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 20 to 70 mol% per cationic polymer. When the non-reactive monomer component (b) is less than 20 mol%, the adhesion to the polyester film and the cohesiveness of the coating film are undesirably lowered. When it exceeds 70 mol, the antistatic property is lowered, which is not preferable.

  Reactive monomer components constituting the cationic polymer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and other hydroxy-containing monomers; glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether Epoxy group-containing monomers such as 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.) Monomers containing a carboxy group or a salt thereof; acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.), N-alkoxy Acrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide, N, N-dialkoxymethacrylamide (alkoxy groups include methoxy group, ethoxy group, butoxy group, isobutoxy group, etc.), acryloylmorpholine, N-methylol Monomers containing amide groups such as acrylamide, N-methylol methacrylamide, N-phenyl acrylamide, N-phenyl methacrylamide; monomers of acid anhydrides such as maleic anhydride and itaconic anhydride; vinyl isocyanate, allyl isocyanate It can be exemplified an isocyanate-containing monomer sulfonates and the like.

  The reactive monomer component (c) is preferably used in the range of 1 to 40 mol% per cationic polymer. If it is less than 1 mol%, the antistatic property against water resistance is lowered, and the surface resistivity change rate after immersion for 10 hours at 50 ° C. in warm water exceeds 100, such being undesirable. If it exceeds 40 mol%, the number of cross-linking points increases and the film forming property of the coating film deteriorates, which is not preferable.

The cationic polymer is preferably composed of a monomer component (a), a non-reactive monomer component (b), and a reactive monomer component (c). The composition ratio of each component preferably satisfies the following formula.
30 mol% ≦ a <79 mol%
20 mol% ≦ b <100− (a + c) mol%
1 mol% ≦ c ≦ 40 mol%
When composed of components satisfying these conditions, it is possible to obtain a coating film excellent in film forming properties, cohesive strength, water resistance of the coating film, and chemical resistance.

  It is preferable that fine particles are contained in the antistatic layer. When the fine particles are contained, those having an average particle diameter of 20 to 100 nm, more preferably 40 to 80 nm are preferably used. When the average particle diameter is less than 20 nm, the blocking property and the film winding property when the film is wound are inferior, and furthermore, in the form of the in-mold transfer foil, the antistatic layer is in contact with the printed layer, but at this time It is not preferable because blocking between the prevention layer and the printing layer may occur. When the average particle diameter exceeds 100 nm, omission of fine particles and transparency of the coating layer may be deteriorated, which is not preferable.

  The fine particles are preferably contained in the antistatic layer in an amount of 5 to 30% by weight. If it is less than 5% by weight, blocking of the antistatic layer and the printed layer may occur in the form of the in-mold transfer foil, which is not preferable. If it exceeds 30% by weight, fine particles may be lost from the coating layer, which is not preferable.

As the fine particles, either inorganic fine particles or organic fine particles can be used.
Examples of the inorganic fine particles include silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, titanium oxide, zinc oxide, barium sulfate, zirconium oxide, titanium oxide, tin oxide, antimony trioxide, carbon black, molybdenum disulfide. The particle | grains which consist of can be illustrated. Examples of the organic fine particles include organic fine particles made of a heat resistant resin such as an acrylic cross-linked polymer, a styrene cross-linked polymer, a silicone resin, a fluororesin, a benzoguanamine resin, a phenol resin, and a nylon resin.

  In particular, silicon oxide, cross-linked polystyrene resin particles, and cross-linked acrylic resin particles are particularly preferable from the viewpoints of handling and stability in the coating liquid and dispersibility in the coating film. The coating thickness for final drying is preferably 0.05 to 0.3 μm, more preferably 0.07 to 0.2 μm. If the thickness of the coating film is less than 0.05 μm, the adhesiveness is insufficient, and if it exceeds 0.3 μm, blocking tends to occur, which is not preferable.

  It is preferable to add a cross-linking agent to the antistatic layer in order to improve the cohesive strength of the coating film and to suppress the precipitation oligomer during heating. As a crosslinking agent, an epoxy compound, an oxazoline compound, a melamine compound, an isocyanate compound can be illustrated, and another coupling agent 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 specifically, it can be exemplified as follows.
Examples of the epoxy compound include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, etc. Examples of the polyepoxy compounds include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diester. Glycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, diepoxy compounds include, for example, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol As diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, monoepoxy compound, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, glycidyl amine compound N, N, N ′, N ′,-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like.

  The oxazoline is preferably a polymer containing an oxazoline group. 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 limited as long as it is a monomer copolymerizable with an addition-polymerizable oxazoline group-containing monomer, such as alkyl acrylate, alkyl methacrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, (meth) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, Unsaturated carboxylic acids such as styrenesulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; acrylamide, methacrylamide, N-alkyl Acrylamide, N-alkyl methacrylate N, N-dialkylacrylamide, N, N-dialkylmethacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl Group, cyclohexyl group, etc.); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; vinyl chloride and vinylidene chloride And halogen-containing α, β-unsaturated monomers such as vinyl fluoride; α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like, one or more of these The monomers can be used.

  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 the coupling agent, an organometallic compound containing a metal such as zirconium, titanium, or aluminum can be used. For example, those classified into alkoxides, chelates, and acylates are preferable. Specifically, zirconium tetraacetylacetonate, zirconium acetate, titanium acetylacetonate, triethanolamine titanate, and titanium lactate can be exemplified.

  When a crosslinking agent is used, the amount of crosslinking agent added is preferably 5 to 50% by weight. If it is less than 5% by weight, the cohesive force of the coating layer is lowered, and the durability may be deteriorated. If it exceeds 50% by weight, the film forming property of the coating layer is deteriorated, and the coating appearance is deteriorated.

  In the present invention, the antistatic layer is preferably provided on the polyester film 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 it is less than 0.01 μm, the antistatic property is insufficient, which is not preferable, and if it exceeds 0.1 μm, blocking with the in-mold transfer foil is likely to occur, which is not preferable.

The surface resistivity of the antistatic layer is preferably 1 × 10 ¹³ Ω / □ or less, more preferably 1 × 10 ¹² or less, and the surface resistivity of the surface of the antistatic layer after being immersed in warm water at 50 ° C. for 10 hours. The resistance change rate is preferably 100 or less, more preferably 10 or less. The rate of change of the surface resistivity is a value obtained by dividing the surface resistivity of the surface of the antistatic layer after being immersed in pure water at 50 ° C. for 10 hours by the surface resistivity of the surface of the untreated antistatic layer. is there. When the surface resistivity exceeds 1 × 10 ¹³ Ω / □, the antistatic property required in the present invention cannot be obtained, which is not preferable. And when the surface resistivity change rate of the surface of the antistatic layer after being immersed in warm water of 50 ° C. for 10 hours exceeds 100, unnecessary substances are removed using washing water in a process such as printing of the in-mold transfer foil. In doing so, the antistatic layer may be eluted, which is not preferable.

[Easily adhesive layer]
In the present invention, it is preferable that an easy adhesion layer is provided on the side of the polyester film opposite to the antistatic 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 the release layer. As the copolyester, for example, a polyester obtained from the following polybasic acid component and diol component can be used. That is, as the polyvalent base component, for example, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, Examples include pyromellitic acid, dimer acid, and 5-sodium sulfoisophthalic acid. As the polyester resin constituting the polymer binder, it is preferable to use a copolymerized polyester using two or more kinds of dicarboxylic acid components. The polyester may contain an unsaturated polybasic acid component such as maleic acid or itaconic acid, or a hydroxycarboxylic acid component such as p-hydroxybenzoic acid, if it is in a slight amount. Examples of the diol component of polyester include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, and the like, poly (ethylene oxide) ) Glycol and poly (tetramethylene oxide) glycol.

  The copolyester preferably has a glass transition point (Tg) of 40 to 85 ° C, more preferably 45 to 80 ° C. A film obtained when the Tg of the copolyester is less than 40 ° C. is not preferable because the heat resistance and blocking resistance are inferior, and if it exceeds 85 ° C., the easy adhesion property is not preferable.

  The copolymerized polyester is preferably used in the form of an aqueous dispersion or an emulsion to form a coating layer. In order to form a coating layer, other resins, colorants, antistatic agents, catalysts, stabilizers, surfactants, antioxidants, ultraviolet absorbers and the like may be included as necessary in addition to the copolymer polyester. You can also.

  The easy-adhesion layer preferably contains fine particles. The fine particles preferably have an average particle diameter of 20 to 100 nm, more preferably 40 to 80 nm. When the average particle size is less than 20 nm, the blocking property and the film winding property when the film is wound are inferior, which is not preferable. When the average particle size is more than 100 nm, the lack of fine particles and the transparency of the coating layer may be deteriorated.

  When the fine particles are added, it is preferably used at a ratio of 30% by weight or less per 100% by weight of the easy-adhesion layer. If it exceeds 30% by weight, the strength of the coating layer is lowered, and troubles such as coating film scraping occur in the subsequent steps, which is not preferable.

  Examples of the fine particles include silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, titanium oxide, zinc oxide, barium sulfate, zirconium oxide, titanium oxide, tin oxide, antimony trioxide, carbon black, and molybdenum disulfide. Examples of the organic fine particles include heat-resistant resins such as inorganic fine particles, acrylic cross-linked polymers, styrene cross-linked polymers, silicone resins, fluororesins, benzoguanamine resins, phenol resins, and nylon resins. Among these, silicon oxide, cross-linked polystyrene resin particles, and cross-linked acrylic resin particles are preferable from the viewpoint of handling and stability in the coating liquid and dispersibility in the coating film.

  The thickness of the easy adhesion layer is preferably 0.05 to 0.3 μm, and more preferably 0.07 to 0.2 μm, as the final thickness after drying. If the thickness of the coating film is less than 0.05 μm, the adhesiveness becomes insufficient, which is not preferable, and if it exceeds 0.3 μm, blocking tends to occur, which is not preferable.

[Production method]
In the present invention, the composition used for coating the antistatic layer and the easy-adhesion layer may be used in the form of an aqueous coating solution such as an aqueous solution, an aqueous dispersion, or an emulsion to form a coating layer. preferable. In order to form a coating film, other resins other than the above-described composition, such as a colorant, a surfactant, and an ultraviolet absorber, can be added as necessary.

  The solid content concentration of the aqueous coating solution used in the present invention is usually 20% by weight or less, preferably 1 to 10% by weight. If it is less than 1% by weight, the coating properties on the polyester film may be insufficient, and if it exceeds 20% by weight, the stability of the coating liquid and the appearance of the coating layer may be deteriorated.

  Application of the aqueous coating solution to the polyester film can be carried out at any stage, but it is preferably carried out during the production process of the polyester film, and is further applied to the polyester film before the completion of orientational crystallization. Is preferred.

  Here, the polyester film before the completion of crystal orientation is an unstretched film, a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, and further in two directions, the longitudinal direction and the transverse direction. It includes those that have been stretched and oriented at a low magnification (biaxially stretched film before being finally re-stretched in the machine direction or the transverse direction to complete orientation crystallization). In particular, it is preferable to apply the aqueous coating liquid of the above composition to an unstretched film or a uniaxially stretched film oriented in one direction, and perform longitudinal stretching and / or lateral stretching and heat setting as it is.

  When applying an aqueous coating liquid to a film, as a pretreatment for improving the coating property, the film surface is subjected to physical treatment such as corona surface treatment, flame treatment, plasma treatment, etc., or chemically combined with the composition. It is preferable to use an inert surfactant in combination.

  Such surfactants promote the wetting of the aqueous coating liquid to the polyester film and improve the stability of the coating liquid. For example, polyoxyethylene-fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal Anionic and nonionic surfactants such as soaps, alkyl sulfates, alkyl sulfonates, and alkyl sulfosuccinates can be mentioned. The surfactant is preferably contained in an amount of 1 to 10% by weight in the composition forming the coating film.

  As a coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method and the like can be used alone or in combination.

Hereinafter, the present invention will be described in more detail with reference to examples. Various physical properties were evaluated by the following methods.
(1) Adhesiveness of antistatic layer The surface of the antistatic layer of the film was rubbed with a finger 10 cm long for 10 reciprocations, the missing state of the coating film was observed, and the antistatic layer adhesion was evaluated according to the following criteria.
A +: No change A: Some change on the surface B: Half of the scratched area is missing C: Most of the scratched area is missing

(2) Antistatic property / surface resistivity The surface resistivity of the antistatic layer surface of the sample film was measured using a resistivity measuring device manufactured by Takeda Riken Co., under the conditions of a measurement temperature of 23 ° C. and a measurement humidity of 60%. The surface resistivity (Ω / □) after 1 minute was measured at an applied voltage of 100V.
-Change rate Furthermore, the surface specific resistance value of the antistatic layer surface after immersing a sample film in the pure water of 50 degreeC for 10 hours was measured by the method similar to the above. The rate of change of the surface resistivity was determined from the untreated surface resistivity and the surface resistivity after being immersed in pure water at 50 ° C. for 10 hours. The rate of change of the surface resistivity is a value obtained by dividing the surface resistivity of the surface of the antistatic layer after being immersed in pure water at 50 ° C. for 10 hours by the surface resistivity of the surface of the untreated antistatic layer. is there.

(3) Blocking resistance In order to evaluate the blocking resistance between the antistatic layer surface of the sample film and the printing surface of the in-mold transfer foil, a stamping foil pigment foil (COLORIT) P type (manufactured by Kurz) is used. The antistatic surface and the printing surface are combined, and the temperature is 60 ° C. and the pressure is 1 kg / cm ^2. After maintaining the environment for 24 hours, the blocking state between the antistatic layer surface and the seal surface of the label is observed. evaluated.
A +: No change A: Some change on the surface B: Partial peeling C: Overall peeling In this evaluation, up to A satisfies the practical performance.

(4) Release layer adhesiveness A 1 μm-thick release layer (medium layer) film is formed by applying a melamine resin methylethylketone / toluene solution on the coating surface of the film, and the laminate is emptied by hot pressing. The state of the release layer when it was molded on the mold was observed and evaluated according to the following criteria.
A: No change B: Partially peeled C: Whole peeled In this evaluation, up to A satisfies practical performance.

(5) Coating layer thickness The film is fixed with an embedding resin, the cross section is cut with a microtome, stained with 2% osmic acid at 60 ° C. for 2 hours, and coated using a transmission electron microscope (JEM2010, manufactured by JEOL Ltd.). The layer thickness was measured.

(6) Comprehensive evaluation Evaluation was performed according to the following criteria.
A +: antistatic layer adhesion is A +, antistatic property is 1 × 10 ¹² Ω / □ or less, change rate of antistatic property is 10 or less, blocking resistance is A +, and release layer adhesion is A (total Evaluation and extremely good).
A: Antistatic layer adhesion is A, antistatic property is 1 × 10 ¹³ Ω / □ or less, rate of change of antistatic property is 100 or less, blocking resistance is A, and release layer adhesiveness is A (total) Evaluation / good).
B: Antistatic layer adhesion, blocking resistance, release layer adhesion is B or more, or antistatic property is 1 × 10 ¹³ Ω / □ to 1 × 10 ¹⁴ Ω / □ or change in antistatic property The rate is 100-1000. (Comprehensive evaluation / defect)
C: Any of the antistatic layer adhesion, blocking resistance, and release layer adhesiveness is C, or the antistatic property is 1 × 10 ¹⁴ Ω / □ or more, or the antistatic property change rate is 1000 or more (total) Evaluation and extremely poor).

[Examples 1-4, Comparative Examples 1-3]
Molten polyethylene terephthalate ([η] = 0.64 dl / g, Tg = 78 ° C.) containing 0.01 wt% of silicon oxide fine particles having an average particle size of 2 μm is extruded from a die and cooled by a cooling drum by a conventional method. After unstretched film and then stretched 3.4 times in the machine direction, each coating solution consisting of coating layer constituents shown in the table (easy-adhesive layer: 6 wt%, antistatic layer: 2 wt%) is uniform with a roll coater. It was applied to.

[Comparative Example 4]
A coated film was obtained in the same manner as in Example 1 except that no antistatic layer was provided. The coated film was subsequently dried at 105 ° C., stretched 3.5 times at 140 ° C., and heat-set at 230 ° C. to obtain a biaxially stretched polyester film (thickness 38 μm) having the coating film shown in the table. It was.

Cationic polymer 1: a copolymer having a structure represented by the following formula: 50 mol% / methyl acrylate 35 mol% / N-methylol acrylamide 15 mol%.

Cationic polymer 2: A copolymer having a structure represented by the following formula: mol% 60 mol% / methyl acrylate 35 mol% / acrylic acid 5 mol%.

Cationic polymer 3: A copolymer having a structure represented by the following formula: 95 mol% / methacrylic acid 5 mol%.

Cationic polymer 4: A homopolymer having a structure represented by the following formula consisting of 100%.

Cationic polymer 5: a copolymer having a structure represented by the following formula: 35 mol% / methyl acrylate 15 mol% / N-methylol acrylamide 50 mol%.

Fine particles 1: Silica fine particles (average particle size: 40 nm) (trade name Snowtex OL manufactured by Nissan Chemical Co., Ltd.).
Fine particle 2: Silica fine particle (average particle size: 80 nm) (trade name Snowtex ZL manufactured by Nissan Chemical Co., Ltd.)
Crosslinking agent 1: Oxazoline (trade name EPOCROSS WS-700, manufactured by Nippon Shokubai Co., Ltd.)
Crosslinking agent 2: Glycerol polyglycidyl ether (trade name Denacol EX-313, manufactured by Nagase ChemteX Corporation)
Cross-linking agent 3: Titanium lactate (Matsumoto Pharmaceutical Co., Ltd., trade name ORGATICS TC-310)
Surfactant: Polyoxyethylene (n = 7) lauryl ether (trade name NAROACTY N-70, manufactured by Sanyo Chemical Industries, Ltd.).

    Copolyester: Acid component is composed of 50 mol% terephthalic acid / 45 mol% isophthalic acid / 5 mol% 5-sodium sulfoisophthalic acid, and the glycol component is composed of 90 mol% ethylene glycol / 10 mol% diethylene glycol (Tg = 40 ° C). In addition, polyester was manufactured as follows according to the method of Example 1 of Unexamined-Japanese-Patent No. 06-116487. 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.

  The in-mold transfer film of the present invention is an in-mold transfer film having excellent handling properties during processing during in-mold transfer, and can be suitably used for in-mold molding.

Claims (3)

Polyester film, moreover antistatic layer containing a cationic polymer provided on one surface, and the other of the glass transition point provided on the surface consists of the easy-adhesion layer comprising a copolyester of 40 to 85 ° C., the cationic polymer Is composed of a monomer component (a), a non-reactive monomer component (b) and a reactive monomer component (c) represented by the following formula, and the composition ratio of each component satisfies the following formula: Film for mold transfer.
30 mol% ≦ a <79 mol%
20 mol% ≦ b <100− (a + c) mol%
1 mol% ≦ c ≦ 40 mol%

  The in-mold transfer film according to claim 1, wherein the antistatic layer further contains a crosslinking agent. The surface resistivity of the antistatic layer is 1 × 10 ¹³ Ω / □ or less, and the surface resistivity change rate of the surface of the antistatic coating layer after being immersed in hot water at 50 ° C. for 10 hours is 100 or less. Item 2. The in-mold transfer film according to Item 1.