JP2020179537A - Laminated film and method for producing the same - Google Patents

Abstract

To provide: a laminated film which has good adhesiveness and temporal adhesiveness with a release layer and can be suitably used as a substrate of a release film; and a method for producing the same.SOLUTION: There are provided: a laminated film having a coating layer on at least one surface of a film, in which the coating layer is a layer formed from a coating liquid containing an organic compound containing a metal element and an epoxy compound; and a method for producing a laminated film having a coating layer on at least one surface of a film, in which the coating layer is formed by coating a coating liquid containing an organic compound containing a metal element and an epoxy compound.SELECTED DRAWING: None

Description

The present invention relates to a laminated film, for example, which exhibits excellent adhesion stability over time with respect to a silicone release layer, and is used, for example, for manufacturing and protecting various adhesive layers and for a liquid crystal display (hereinafter, also referred to as LCD). Suitable for manufacturing LCD components such as polarizing plates and retardation plates used, for manufacturing various display components such as organic electroluminescence (hereinafter, also referred to as organic EL) components, and for various optical applications. It relates to a laminated film used as a base material of a mold film.

The release film based on the film is used for various purposes from the viewpoints of mechanical strength, heat resistance, thermal dimensional stability, chemical resistance and economy. For example, manufacturing of an adhesive layer used for a touch panel. For manufacturing LCD components such as polarizing plates and retardation plates used for protection, for manufacturing LCD components, for manufacturing various display components such as organic EL components, and for medical adhesive films such as wettable powders / patches. Examples include ceramic sheet applications, polyvinyl chloride sheet, carbon fiber and other molding process applications, labels, adhesive tapes, decorative boards and transfer tapes and other industrial applications.

A resin film, for example, a polyester film may be used as the base material of the release film, but in this case, the adhesion between the polyester film and the release layer and the adhesion with time are problems.

In order to solve the above problems, Patent Document 1 discloses a silicone easy-adhesive polyester film in which a coating layer containing a silane coupling agent and an alkoxy-modified silicone compound is provided on at least one side of the polyester film.

Further, Patent Document 2 is a release film having a coating layer on at least one side of a polyester film and a release layer on the coating layer, and at least a condensed polycyclic aromatic structure in the coating layer. A release film characterized by containing a copolymerized polyester resin having an acid component and an aliphatic acid component is disclosed.

Japanese Unexamined Patent Publication No. 2004-43625 JP-A-2017-164959

However, according to the study by the present inventors, when a coating layer is provided between the film and the release layer in order to improve the adhesion between the film and the release layer and the adhesion over time, it is on the coating layer. It has been found that when the release agent composition is applied and dried, the oligomer contained in the film is precipitated on the surface, and the transparency of the release film is deteriorated.
The present invention has been made in view of the above circumstances, and an object of the present invention is to preferably use it as a base material for a release film, which has good adhesion to a release layer and adhesion over time and excellent transparency. The purpose is to provide a laminated film capable of producing.

As a result of diligent studies to solve the above problems, the present inventors have provided a coating layer formed of a coating liquid containing a combination of specific compounds on at least one surface of the film to form a release layer. We have found that both adhesion, adhesion with time, and transparency are good, and have reached the present invention.

That is, the gist of the present invention is a laminated film having a coating layer on at least one side of the film, and the coating layer is a layer formed of a coating liquid containing an organic compound containing a metal element and an epoxy compound. It exists in the laminated film characterized by the above and the manufacturing method thereof.

According to the laminated film of the present invention, both adhesion to the release layer, adhesion over time, and transparency are improved, and the film can be suitably used as a base material for a release film used for various purposes. The target value is high.

Next, the present invention will be described based on examples of embodiments. However, the present invention is not limited to the embodiments described below.

<< Laminated film >>
The laminated film is a laminated film having a coating layer on at least one side of the film as a base material, and the coating layer is a layer formed of a coating liquid containing an organic compound containing a metal element and an epoxy compound. It is characterized by.

<Film>
As the film constituting the laminated film of the present invention, conventionally known films can be used, for example, polyester film, polycarbonate film, fluororesin film, polyimide film, triacetyl cellulose film, polyolefin film, polyacrylate film, and the like. Examples thereof include polystyrene film, polyvinyl chloride film, polyvinyl alcohol film, ethylene vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, nylon film and the like. In particular, it is preferable to have heat resistance in order to develop it into various applications, and polyester film, polycarbonate film, fluororesin film, and polyimide film are preferably used, and polyester is further considered in terms of transparency, moldability, and versatility. Films are more preferably used.
The film constituting the laminated film of the present invention may have a single-layer structure or a multilayer structure of two or more layers, and is not particularly limited.
The polyester film may be a non-stretched film (sheet) or a stretched film. Of these, a stretched film stretched in the uniaxial direction or the biaxial direction is preferable. Among them, a biaxially stretched film is preferable because it is excellent in balance of mechanical properties and flatness.

The polyester used for the polyester layer constituting the polyester film may be a homopolyester or a copolymerized polyester.
When it is made of homopolyester, it is preferably obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol and 1,4-cyclohexanedimethanol. Examples of typical polyesters include polyethylene terephthalate and the like.
On the other hand, examples of the dicarboxylic acid component of the copolymerized polyester include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid and the like, and glycol. Examples of the component include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexanedimethanol, neopentyl glycol and the like.

The polyester polymerization catalyst is not particularly limited, and conventionally known compounds can be used. Examples thereof include antimony compounds, titanium compounds, germanium compounds, manganese compounds, aluminum compounds, magnesium compounds and calcium compounds.

(particle)
Particles can also be blended in the film of the present invention mainly for the purpose of imparting slipperiness and preventing scratches in each step. When the particles are blended, the type of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness. Specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, and sulfuric acid. Examples thereof include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin and benzoguanamine resin. Further, during the polyester manufacturing process, precipitated particles in which a part of a metal compound such as a catalyst is precipitated can also be used. Among these, silica particles are particularly preferable in that a small amount is likely to produce an effect.

The average particle size of the particles is usually 5 μm or less, preferably 0.01 to 3 μm. When the average particle size is 5 μm or less, the surface roughness of the film becomes appropriate, and problems are less likely to occur when various functional layers or the like are formed in a subsequent step.
In the case of powder, the average particle size of the particles can be measured using a particle size distribution measuring device.
When the particles are present in the film, the cross section of the film can be observed using a transmission electron microscope, and for example, the average value of the particle sizes of 10 particles can be used as the average particle size.

Further, the particle content in the film is usually 5% by mass or less, preferably 0.0003 to 3% by mass. If there are no particles in the film, or if the amount is small, the transparency of the film becomes high and the film becomes good, but the slipperiness may be insufficient. Therefore, 5 mass of particles are added to the coating layer. By adding% or less, the transparency of the film can be ensured while improving the slipperiness.

The shape of the particles to be used is not particularly limited, and any of spherical, lumpy, rod-shaped, flat-shaped and the like may be used. Further, the hardness, specific gravity, color and the like are not particularly limited.
Two or more kinds of these series of particles may be used in combination, if necessary.

The method of adding the particles to the film is not particularly limited, and a conventionally known method can be adopted.

(Other additives)
In addition to the above-mentioned particles, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, ultraviolet absorbers and the like can be added to the film of the present invention as needed. it can.

(Film thickness)
The thickness of the film in the present invention is not particularly limited as long as it can be formed as a film, but is usually in the range of 10 to 350 μm, preferably 20 to 300 μm.

As the film forming method of the laminated film of the present invention, a generally known film forming method can be adopted, and there is no particular limitation.
For example, in the case of producing a biaxially stretched polyester film, first, the polyester raw material described above is melt-extruded from a die using an extruder, and the molten sheet is cooled and solidified with a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and the electrostatic application adhesion method and the liquid coating adhesion method are preferably adopted. Next, the obtained unstretched sheet is stretched in one direction by a roll or tenter type stretching machine. The stretching temperature is usually 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Then, in the direction orthogonal to the stretching direction of the first stage, stretching is usually performed at 70 to 170 ° C. and a stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. A method of subsequently performing heat treatment at a temperature of 180 to 270 ° C. under tension or relaxation within 30% to obtain a biaxially oriented film can be mentioned. In the above stretching, a method of stretching in one direction in two or more steps can also be adopted. In that case, it is preferable to finally set the stretching ratios in the two directions within the above ranges.

Further, a simultaneous biaxial stretching method can be adopted for producing a polyester film. The simultaneous biaxial stretching method is a method of simultaneously stretching and orienting the unstretched sheet in the mechanical direction and the width direction in a state where the temperature is controlled at usually 70 to 120 ° C., preferably 80 to 110 ° C. Is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in area magnification. Then, the heat treatment is subsequently performed at a temperature of 170 to 270 ° C. under tension or relaxation within 30% to obtain a stretch-oriented film. As for the simultaneous biaxial stretching device that employs the above-mentioned stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be adopted.

In the laminated film of the present invention, as a method of forming a coating layer, for example, a gravure coat, a reverse roll coat, a die coat, an air doctor coat, a blade coat, a rod coat, a bar coat, a curtain coat, a knife coat, a transfer roll coat, etc. Conventionally known coating methods such as squeeze coat, impregnation coat, kiss coat, spray coat, calender coat, and extrusion coat can be used.

When a polyester film is used as the film, the coating layer may be formed by an in-line coating that treats the film surface during the process of forming the polyester film.

The in-line coating is a method of coating in a film forming process, and specifically, a method of coating at an arbitrary stage from melt extrusion of a film raw material to stretching and heat treatment to wind up. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat treatment, and a film after heat treatment and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) and then stretching in the lateral direction is particularly excellent. According to such a method, since the film formation and the coating layer formation can be performed at the same time, there is an advantage in manufacturing cost, and the thickness of the coating layer can be changed by the stretching ratio in order to perform stretching after coating. , Thin film coating can be performed more easily than offline coating.

According to the in-line coating process, the thickness of the film does not change significantly depending on the presence or absence of the coating layer, and the risk of scratches and foreign matter adhesion does not change significantly depending on the presence or absence of the coating layer. This is a great advantage over the offline coating performed.

Further, by providing the coating layer on the film before stretching, the coating layer can be stretched together with the film, whereby the coating layer can be firmly adhered to the film.

In addition, in the production of biaxially stretched film, the film can be restrained in the vertical and horizontal directions by stretching while gripping the end of the film with a clip or the like, and in the heat treatment step, it is smoothed without wrinkles or the like. High temperature can be applied while maintaining the sex.
Therefore, since the heat treatment applied after coating can be at a high temperature which cannot be achieved by other methods, the film-forming property of the coating layer can be improved, and the coating layer and the film can be more firmly adhered to each other. Can be a strong coating layer.
Further, as described above, there is an advantage that the heat resistance of the film can be improved by stretching while gripping the end portion of the film and forming a coating layer through a heat treatment step.

The temperature of the heat treatment of the coating layer provided by the in-line coating is preferably 55 to 300 ° C., more preferably 70 to 290 ° C., further preferably 90 to 280 ° C., particularly preferably 170 ° C. to 270 ° C., and most preferably 200 ° C. to 200 ° C. It is 250 ° C. As a guide, heat treatment should be performed for 3 to 200 seconds.

Further, if necessary, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination. The surface of the film constituting the laminated film in the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in advance before the coating layer is provided.

Regarding the formation of the coating layer, the laminated film is coated on the film with a coating liquid having a solid content concentration of about 0.1 to 80% by mass as a guide, using a series of compounds described later as a solution or a dispersion of a solvent. It is preferable to manufacture. When the coating layer is provided by in-line coating, the coating liquid is preferably an aqueous solution or an aqueous dispersion, but for the purpose of improving dispersibility in water, improving film formation, etc., a small amount of organic solvent is contained in the coating liquid. May be contained. Further, only one type of organic solvent may be used, and two or more types may be used as appropriate.

<Coating layer>
The laminated film of the present invention has a structure in which a coating layer is formed on at least one side of the film, and the coating layer is formed of a coating liquid containing an organic compound containing a metal element and an epoxy compound. It is a layer.

In the present invention, when the release layer is provided on the coating layer by forming the coating layer using a coating liquid containing an organic compound containing a metal element and an epoxy compound, the adhesion between the release layer and the film -It was found that the adhesion over time was improved and the transparency of the film could be maintained.
The reason for this is not clear, but by combining an organic compound containing a metal element and an epoxy compound, it is easier to form a dense coating layer than when each is used alone, and the oligomer contained in the film is a release layer. It is considered that it is possible to prevent precipitation on the side surface and maintain the transparency of the release film.
Further, since the above combination is less likely to cause curing inhibition of the release agent composition for forming the release layer provided on the coating layer, a sufficiently cured release layer can be formed. Furthermore, it is considered that the above combination promotes the cleavage reaction of the epoxy compound as compared with the case where the epoxy compound is used alone, and as a result, it is easy to secure the adhesion between the film and the release layer, and the adhesion and aging of the release layer It is considered that the adhesion can be improved.

(Organic compounds containing metal elements)
The organic compound containing a metal element in the present invention includes a compound containing a metal-carbon bond, a metal alkoxide compound, a metal acylate compound, and a metal chelate compound.
Among these, a metal chelate compound is preferable from the viewpoint of easily forming a dense coating layer, and the metal species include titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), and iron (Mn). Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), indium (In), tin (Sn), hafnium (Hf), aluminum (Al), zirconium (Zr), gallium ( Ga) and the like. Of these, titanium, zirconium, and aluminum are preferable from the viewpoint of water solubility.

Examples of the organic compound containing titanium as a metal species include titanium orthoesters such as tetranormal butyl titanate, tetraisopropyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, and tetramethyl titanate; titanium acetylacetonate and titanium. Titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium aminoethylaminoethanolate, titanium lactate, titanium lactate ammonium salt, titanium triethanolaminate, titanium chelate such as titanium ethyl acetoacetate Titanium chelate is preferable from the viewpoint of application to water-based paints and suppression of oligomer precipitation, and more specifically, titanium lactate, titanium lactate ammonium salt, and titanium triethanol aminated are more preferable.
Further, from the viewpoint of adhesion to the release layer, an organic compound containing titanium as a metal species and having a hydroxyl group is preferable. Specific examples thereof include titanium lactate and titanium lactate ammonium salt.

Examples of the organic compound containing zirconium as a metal species include zirconium alkoxide compounds such as zirconium acetate, zirconium normal propylate, and zirconium normal butyrate; zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, and zirconium. Examples thereof include zirconium chelates such as lactate ammonium salt, and zirconium chelates are preferable from the viewpoint of application to water-based paints and suppression of oligomer precipitation, and specifically, zirconium lactate ammonium salt is preferable.
Further, from the viewpoint of adhesion to the release layer, an organic compound containing zirconium as a metal species and having a hydroxyl group is preferable. Specifically, for example, a zirconium lactate ammonium salt can be mentioned.

As the organic compound containing these metal elements, only one kind may be used, or two or more kinds may be mixed and used as appropriate.

(Epoxy compound)
By forming the coating layer in the present invention from a coating liquid containing an epoxy compound, a crosslinked structure is formed in the coating layer, and a dense film can be formed. Further, it is considered that the epoxy compound is unlikely to cause curing inhibition of the release agent composition forming the release layer provided on the coating layer. Furthermore, it is considered that the hydroxyl groups generated by the cleavage reaction of the epoxy compound affect the adhesion to the release layer.
The epoxy compound in the present invention is a compound having an epoxy group in the molecule, and among the epoxy compounds, a water-soluble epoxy compound is preferable. The type of the epoxy compound is not particularly limited, and examples thereof include a condensate of epichlorohydrin and an hydroxyl group or an amino group such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A. There are diepoxy compounds, monoepoxy compounds, glycidylamine compounds and the like. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyltris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, and trimethylolpropane. Examples of the polyglycidyl ether and the diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , Polypropylene glycol diglycidyl ether, Polytetramethylene glycol diglycidyl ether, Monoepoxy compounds include, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenylglycidyl ether, glycidylamine compounds N, N, N', N ′ -Tetraglycidyl-m-xylylene diamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like can be mentioned.
Among the epoxy compounds, a polyepoxy compound is preferable from the viewpoint of reacting with an organic compound containing a metal element to form a denser coating layer and suppressing precipitation of oligomers.

The epoxy compound preferably has an epoxy equivalent (g / eq) of 200 or less, and more preferably 150 or less, from the viewpoint of forming a denser coating layer and suppressing precipitation of oligomers.

(Other ingredients)
Various binder resins can be used in combination with the coating layer in the present invention in order to improve the coating appearance and transparency, and to adjust the viscosity of the coating liquid used for forming the coating layer. By containing the binder resin, the coatability of the coating liquid on the film can be improved, and the coating appearance can be improved.
Here, the binder resin refers to a resin excluding the organic compound containing the metal element and the epoxy compound.

As the binder resin, a known resin can be used. Specific examples of the resin include polyester resin, urethane resin, acrylic resin, polyvinyl alcohol, and the like, and among them, polyvinyl alcohol is preferable from the viewpoint of forming a more dense coating layer.

The polyvinyl alcohol is a compound having a polyvinyl alcohol moiety. For example, conventionally known polyvinyl alcohol can be used, including a modified compound which is partially acetalized or butyralized with respect to polyvinyl alcohol.
The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably in the range of 300 to 40,000. If the degree of polymerization is less than 100, the water resistance of the coating layer may decrease. The degree of saponification of polyvinyl alcohol is not particularly limited, but is usually 70 mol% or more, preferably in the range of 70 to 99.9 mol%, more preferably 80 to 97 mol%, and particularly preferably 86 to. A 95 mol% polyvinyl acetate saponified product is practically used.

Examples of the polyester resin include those composed of the following polyvalent carboxylic acids and polyvalent hydroxy compounds as main constituents. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 2,6 -Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaru Acids, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, monopotassium trimellitic acid and their ester-forming derivatives can be used. As polyvalent hydroxy compounds, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanedioyl, 2 -Methyl-1,5-pentandiol, neopentylglycol, 1,4-cyclohexanedimethanol, p-xylyleneglycol, bisphenylene A-ethyleneglycol adduct, diethyleneglycol, triethyleneglycol , Polyethylene glycol, Polypropylene glycol, Polytetramethylene glycol, Polytetramethylene oxide glycol, Dimethylolpropionic acid, Glycerin, Trimethylolpropane, Sodium dimethylolethylsulfonate, Dimethylolpropion Potassium acid or the like can be used. One or more of each of these compounds may be appropriately selected, and a polyester resin may be synthesized by a conventional polycondensation reaction.

The urethane resin is a polymer compound having a urethane bond in the molecule, and is usually produced by a reaction between a polyol and an isocyanate. Examples of the polyol include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, and acrylic polyols, and these compounds may be used alone or in a plurality of types.

Polypolypolyols include polyvalent carboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides. Products and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-Methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol , 2-Methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2 , 5-Diol-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2 -Hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, lactonediol, etc.), lactone compounds such as polycaprolactone Examples thereof include those having a derivative unit.

Polycarbonate polyols are obtained from polyhydric alcohols and carbonate compounds by a dealcohol reaction. Examples of polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Examples thereof include diol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 3,3-dimethylol heptane. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate and the like, and examples of the polycarbonate-based polyols obtained from these reactions include poly (1,6-hexylene) carbonate and poly (3-). Methyl-1,5-pentylene) carbonate and the like can be mentioned.

Examples of the polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol and the like.

Examples of the polyisocyanate compound used to obtain a urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylenedi isocyanate, naphthalene diisocyanate, and trizine diisocyanate, α, α, α', and α'. − Arophilic diisocyanates such as tetramethylxylylene diisocyanate, methylene diisocyanates, propylene diisocyanates, lysine diisocyanates, trimethylhexamethylene diisocyanates, aliphatic diisocyanates such as hexamethylene diisocyanates, cyclohexane diisocyanates, methylcyclohexane diisocyanates, isophorone diisocyanates, dicyclohexyl Examples thereof include alicyclic diisocyanates such as methane diisocyanate and isopropyridene dicyclohexyl diisocyanate. These may be used alone or in combination of two or more.

A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with the isocyanate group, and is generally a hydroxyl group. Alternatively, a chain extender having two amino groups can be mainly used.

Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, and esters such as neopentyl glycol hydroxypivalate. Examples of glycols such as glycols can be mentioned. Examples of the chain extender having two amino groups include aromatic diamines such as tolylene diamine, xylylene diamine, and diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-. Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- Aliphatic diamines such as decanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isoprovilitincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1 , 3-Bisaminomethylcyclohexane and other alicyclic diamines and the like.

The urethane resin in the present invention may use a solvent as a medium, but is preferably water as a medium. To disperse or dissolve the urethane resin in water, there are a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, a water-soluble type, and the like. In particular, a self-emulsifying type in which an ion group is introduced into the structure of a urethane resin to form an ionomer is preferable because it is excellent in storage stability of the liquid and the water resistance, transparency, and adhesion of the obtained coating layer.

Examples of the ionic group to be introduced include various types such as a carboxyl group, a sulfonic acid, a phosphoric acid, a phosphonic acid, and a quaternary ammonium salt, and a carboxyl group is preferable. As a method for introducing a carboxyl group into the urethane resin, various methods can be taken in each stage of the polymerization reaction. For example, at the time of prepolymer synthesis, there are a method of using a resin having a carboxyl group as a copolymerization component and a method of using a component having a carboxyl group as one component of a polyol, a polyisocyanate, a chain extender and the like. In particular, a method of using a carboxyl group-containing diol and introducing a desired amount of carboxyl groups according to the amount of this component charged is preferable.
For example, copolymerizing dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid, etc. with the diol used for polymerizing the urethane resin. Can be done. Further, this carboxyl group is preferably in the form of a salt neutralized with ammonia, amines, alkali metals, inorganic alkalis and the like. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a polyurethane resin, the carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a cross-linking reaction point by another cross-linking agent. As a result, the stability of the liquid before coating is excellent, and the durability, solvent resistance, water resistance, blocking resistance, etc. of the obtained coating layer can be further improved.

The acrylic resin is a polymer composed of a polymerizable monomer containing acrylic and methacrylic monomers (hereinafter, acrylic and methacrylic may be collectively abbreviated as (meth) acrylic). These may be homopolymers or copolymers, and may be copolymers with polymerizable monomers other than acrylic and methacrylic monomers.

Also included are copolymers of these polymers with other polymers (eg polyester, polyurethane, etc.). For example, block copolymers and graft copolymers. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer (in some cases, a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included.

The polymerizable monomer is not particularly limited, but as a particularly representative compound, various carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid are used. Classes and salts thereof; various types such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutylhydroquilfumarate, monobutylhydroxyitaconate Hydroxyl-containing monomers; various types such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate. (Meta) acrylic acid esters; various nitrogen-containing compounds such as (meth) acrylamide, diacetone acrylamide, N-methylol acrylamide or (meth) acrylonitrile; such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene. Various styrene derivatives, various vinyl esters such as vinyl propionate, vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, etc .; phosphorus-containing vinyl-based Monomers; various vinyl halides such as vinyl chloride and billidene chloride; various conjugated dienes such as butadiene.

Further, in addition to the organic compound containing a metal element, the epoxy compound and the binder resin, a cross-linking agent can be used in combination for forming the coating layer. By reacting with functional groups such as organic compounds containing metal elements, epoxy compounds, and various binder resins, a more dense film can be formed and precipitation of oligomers can be suppressed.

Conventionally known materials can be used as the cross-linking agent, and examples thereof include melamine compounds, oxazoline compounds, isocyanate compounds, and carbodiimide compounds. Further, it is also possible to use two or more kinds of cross-linking agents in combination in order to improve the film-forming property.

A melamine compound is a compound having a melamine skeleton in the compound, for example, an alkylolated melamine derivative, a compound obtained by reacting an alkylolated melamine derivative with an alcohol to partially or completely etherify, and these. A mixture can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Further, the melamine compound may be either a monomer or a multimer of a dimer or more, or a mixture thereof may be used. Further, it is also possible to use a melamine that is copolymerized with urea or the like.

The oxazoline compound is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable, and it can be prepared by polymerization of an addition-polymerizable oxazoline group-containing monomer alone or with another monomer. Additive 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, Examples thereof include 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and one or a mixture of two or more thereof can be used. Of these, 2-isopropenyl-2-oxazoline is industrially readily available and suitable. The other monomer is not limited as long as it is a monomer copolymerizable with an addition-polymerizable oxazoline group-containing monomer, and is, for example, an alkyl (meth) acrylate (as an alkyl group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc. (Meta) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth) acrylamide, N-alkyl ( Meta) acrylamide, N, N-dialkyl (meth) acrylamide, (alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl Unsaturated amides such as 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, vinylidene chloride , Halogen-containing α, β-unsaturated monomers such as vinyl fluoride; α, β-unsaturated aromatic monomers such as styrene, α-methylstyrene, etc., and one or more of these. Monomer can be used.

The isocyanate-based compound is a compound having an isocyanate derivative structure typified by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylenedi isocyanate and naphthalene diisocyanate, and aromatic rings such as α, α, α'and α'-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanates, methylene diisocyanates, propylene diisocyanates, lysine diisocyanates, trimethylhexamethylene diisocyanates, hexamethylene diisocyanates, cyclohexane diisocyanates, methylcyclohexane diisocyanates, isophorone diisocyanates, methylenebis (4-cyclohexylisocyanates), isopropyridene dicyclohexyldiisocyanates and the like. The alicyclic isocyanate of the above is exemplified. In addition, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimides of these isocyanates can also be mentioned. These may be used alone or in combination of two or more. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

When used in the state of blocked isocyanate, the blocking agent includes, for example, phenolic compounds such as heavy sulfites, phenol, cresol and ethylphenol, and alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol and ethanol. Compounds, active methylene compounds such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, mercaptan compounds such as butyl mercaptan and dodecyl mercaptan, lactam compounds such as ε-caprolactam and δ-valerolactam. , Amine compounds such as diphenylaniline, aniline, ethyleneimine, acid amide compounds of acetanilide and acetate amide, oxime compounds such as formaldehyde, acetoaldoxime, acetone oxime, methyl ethyl ketone oxime, cyclohexanone oxime, and these alone Two or more kinds may be used in combination.

Further, the isocyanate-based compound in the present invention may be used alone, or may be used as a mixture or a bond with various polymers. In terms of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or a bond with a polyester resin or a urethane resin.

The carbodiimide-based compound is a compound having a carbodiimide structure, and is used for improving the adhesion to various surface functional layers that can be formed on the coating layer and improving the moisture and heat resistance of the coating layer. is there. The carbodiimide-based compound is a compound having one or more carbodiimide or a carbodiimide derivative structure in the molecule, but a polycarbodiimide-based compound having two or more in the molecule is more preferable for forming a denser film.

The carbodiimide-based compound can be synthesized by a conventionally known technique, and a condensation reaction of a diisocyanate compound is generally used. The diisocyanate compound is not particularly limited, and any aromatic type or aliphatic type can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylenediisocyanate, naphthalenediisocyanate, hexa Examples thereof include methylene diisocyanis, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyldiisocyanis, and dicyclohexylmethane diisocyanate.

Further, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound within the range where the effect of the present invention is not lost, a surfactant may be added, or a polyalkylene oxide or a quaternary ammonium salt of a dialkylamino alcohol may be added. Hydrophilic monomers such as hydroxyalkyl sulfonate may be added and used.

In addition, these cross-linking agents react in the drying process and the film forming process to improve the performance of the coating layer. It can be inferred that unreacted products of these cross-linking agents, compounds after the reaction, or mixtures thereof are present in the completed coating layer.

Various particles can be used in combination with the coating layer in the present invention for the purpose of improving the slipperiness of the laminated film and preventing blocking. Specific examples of the particles include (meth) acrylic acid ester. Examples thereof include organic particles obtained by polymerizing monomers such as styrene and silicone, and inorganic particles containing inorganic substances such as silica, alumina, kaolin, calcium carbonate, titanium oxide, and barium salt as constituents.

The average particle size of the particles is preferably in the range of 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.2 μm or less from the viewpoint of film transparency. The lower limit of the average particle size of the particles is not particularly limited, but is usually 0.001 μm or more.

Further, as long as the gist of the present invention is not impaired, a defoaming agent, a coating property improving agent, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are necessary for forming the coating layer. , Foaming agents, dyes, pigments and the like can also be used in combination.

The ratio of the organic compound containing a metal element to the total non-volatile components in the coating liquid forming the coating layer in the laminated film of the present invention is usually 10 to 90% by mass, preferably 30 to 70% by mass, and more preferably 40 to 60%. It is in the range of mass%. Within the above range, there is a high possibility that the coating layer can achieve both suppression of oligomer precipitation and adhesion to the release layer.

The ratio of the epoxy compound to the total non-volatile components in the coating liquid forming the coating layer in the laminated film of the present invention is usually in the range of 10 to 90% by mass, preferably 30 to 70% by mass, and more preferably 40 to 60% by mass. Is. Within the above range, there is a high possibility that the coating layer can achieve both suppression of oligomer precipitation and adhesion to the release layer.

Blending ratio of organic compound containing metal element and epoxy compound in all non-volatile components in the coating liquid forming the coating layer in the laminated film of the present invention (content of organic compound containing metal element / content of epoxy compound) Is preferably in the range of 0.2 to 5, more preferably in the range of 0.4 to 3, further preferably in the range of 0.6 to 1.5, and particularly preferably in the range of 0.9 to 1.3.

When the binder resin is contained in the coating liquid forming the coating layer in the laminated film of the present invention, the binder resin is usually 5 to 70% by mass, preferably 10 to 60% by mass, as a ratio to the total non-volatile components in the coating liquid. , More preferably in the range of 20 to 50% by mass. Within the above range, there is a high possibility that adhesion with the release layer can be achieved while forming a dense coating layer.

(Film thickness of coating layer)
The film thickness of the coating layer in the laminated film of the present invention is usually 0.001 to 1.0 μm, preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.35 μm, and particularly preferably 0.02 to 0.02. The range is 0.25 μm. When the film thickness is within the above range, the film-forming property of the laminated film and the adhesion with the release layer can be ensured, the oligomer precipitation can be suppressed, and the film haze change due to heating can be suppressed. Become.

<Laminated structure of laminated film>
Since the laminated film of the present invention may be provided with a coating layer on at least one side of the film, it may have a laminated structure in which the coating layer is laminated on one side or both sides of the film, or on one side of the film. The coating layer may be laminated and another layer may be provided on the other surface side.
Examples of the "other layer" include a release layer, an antistatic layer, and an antiblocking layer.
Here, the coating layer in the present invention is preferably a laminated structure in which the release layer is provided on the coating layer surface side of the laminated film in order to exhibit excellent adhesion stability over time with respect to the release layer.

As long as the release layer has good release performance, the constituent components of the release layer are not particularly limited, but from the viewpoint of obtaining good release performance, a release agent composition for forming the release layer. It is preferable to contain a silicone resin in it. A type containing a curable silicone resin as a main component may be used, or a modified silicone type obtained by graft polymerization with an organic resin such as a urethane resin, an epoxy resin or an alkyd resin, or a fluorosilicone resin or the like is preferably contained.

As the type of the curable silicone resin, any existing curing reaction type such as a thermosetting type such as an addition type and a condensation type and an electron beam curing type such as an ultraviolet curable type can be used, and a plurality of types of curing types can be used. Silicone resin may be used in combination. Further, the coating form of the curable silicone resin when forming the release layer is not particularly limited, and may be any of a form dissolved in an organic solvent, a form of an aqueous emulsion, and a form of no solvent.

The type of the curable silicone resin used in the present invention is not limited, but from the viewpoint of excellent mold release characteristics such as light peelability, the use of the curable silicone resin containing an alkenyl group is preferable in the present invention.
Examples of the curable silicone resin containing an alkenyl group include those represented by the following general formula (1) as diorganopolysiloxane.
R _(3-a) X _a SiO− (RXSiO) _m − (R ₂ SiO) _{n −} SiX _a R _(3-a) … (1)

In the above general formula (1), R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and X is an organic group containing an alkenyl group. a is an integer of 0 to 3, preferably 1 and m is 0 or more, but when a = 0, m is 2 or more, and m and n are numbers satisfying 100 ≦ m + n ≦ 20000, respectively. Moreover, the above formula does not mean a block copolymer. R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group, a phenyl group or a trill group. Examples thereof include an allyl group such as, but a methyl group and a phenyl group are particularly preferable. X is an alkenyl group-containing organic group preferably having 2 to 10 carbon atoms, and specifically, a vinyl group, an allyl group, a hexenyl group, an octenyl group, an acryloylpropyl group, an acryloylmethyl group, a methacryloylpropyl group, and a cyclohexenylethyl. Examples thereof include a group and a vinyloxypropyl group, and a vinyl group and a hexenyl group are particularly preferable. Specifically, a trimethylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer at both ends of the molecular chain (dimethylsiloxane unit 96 mol%, methylhexenylsiloxane unit 4 mol%, dimethylvinylsiloxy group-blocked dimethylsiloxane at both ends of the molecular chain ・Methylhexenylsiloxane copolymer (97 mol% dimethylsiloxane unit, 3 mol% methylhexenylsiloxane unit), dimethylhexenylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer at both ends of the molecular chain (95 mol% dimethylsiloxane unit, methyl Hexenylsiloxane unit 5 mol%).

Next, the Si—H group-containing polyorganosiloxane, which is required to react with a curable silicone resin containing an alkenyl group to form a stronger silicone release layer, is bonded to a silicon atom in one molecule. An organohydrogenpolysiloxane having at least two, preferably three or more hydrogen atoms, which can be linear, branched, cyclic or the like, and is represented by the following general formula (2). However, it is not limited to these.
H _b R ¹ _(3-b) SiO- (HR ¹ SiO) _x − (R ¹ ₂ SiO) _y − SiR ¹ _(3-b) H _b … (2)

In the above general formula (2), R ¹ is a monovalent hydrocarbon group containing no aliphatic unsaturated bond having 1 to 6 carbon atoms. b is an integer of 0 to 3, and x and y are integers. Specifically, trimethylsiloxy group-blocking methylhydrogenpolysiloxane at both ends of the molecular chain, trimethylsiloxy group-blocking dimethylsiloxane / methylhydrogensiloxane copolymer at both ends of the molecular chain, dimethylhydrogensiloxy group-blocking methyl at both ends of the molecular chain Examples thereof include hydrogen polysiloxane and dimethylhydrogensiloxy group-blocking dimethylsiloxane / methylhydrogensiloxane copolymer at both ends of the molecular chain.

Next, specific examples of various types of commercially available curable silicone resins that can be used in the present invention are manufactured by Shin-Etsu Chemical Co., Ltd., KS-774, KS-775, KS-778, KS. -779H, KS-847H, KS-856, X-62-2422, X-62-2461, X-62-1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496 , KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, X-62-7213, X-41-3035, Momentive Performance Materials YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430, TPR6600, TPR6604, TPR6605, Toray Doukoning Co., Ltd. Made by the company, SRX357, SRX211, SD7220, SD7292, LTC750A, LTC760A, LTC303E, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210 Among the DEHESIVE series manufactured by Asahi Kasei Wacker Silicone Co., Ltd., DEHESIVE 636, 919, 920, 921, 924, 929 and the like are exemplified.

In the release layer in the present invention, it is preferable to use a platinum-based catalyst that promotes the addition type reaction in order to arrange the shape of the layer surface and form a strong layer. This component includes platinum chloride acid, an alcohol solution of platinum chloride acid, a platinum-based compound such as a complex of platinum chloride acid and an olefin, a complex of platinum chloride acid and an alkenylsiloxane, platinum black, platinum-supported silica, and platinum-supported activated carbon. Is exemplified. The platinum-based catalyst content in the coating layer is preferably in the range of 0.3 to 3.0% by mass, preferably 0.5 to 2.0% by mass. If the platinum-based catalyst content in the coating layer is lower than 0.3% by mass, problems such as poor peeling force and insufficient curing reaction in the coating layer may occur. On the other hand, when the platinum-based catalyst content in the coating layer exceeds 3.0% by mass, it is costly, the reactivity is increased, and process defects such as generation of gel foreign matter may occur.

In addition, since the addition type reaction is very reactive, acetylene alcohol may be added as a non-reaction inhibitor in some cases. Its components are organic compounds with carbon-carbon triple bonds and hydroxyl groups, but preferably 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexin-3-ol and phenylbuty. It is a compound selected from the group consisting of Noll.

A catalyst can be used in combination in the release layer for the purpose of promoting the hydrolysis / condensation reaction. Specific examples of the catalyst include organic acids such as acetic acid, butyric acid, maleic acid and citric acid, inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid and sulfuric acid, basic compounds such as triethylamine, tetrabutyl titanate and dibutyltin dilaurate. Organic metal salts such as dibutyltin diacetate, dibutyltin dioctate, dibutyltin diolate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dibutyltin benzylmalate, etc., KF, NH ₄ Examples include a fluorine element-containing compound such as F. The catalyst may be used alone or in combination of two or more. Among them, organometallic salts are particularly preferable in that the coating film durability is improved.

Various release control agents may be used in combination in order to adjust the release property of the release layer. In the case of making the peeling force heavy peeling, generally, the content of organopolysiloxane resin, silica particles, silicone type having heavy peeling force, etc. is appropriately adjusted in the release layer in order to obtain the desired peeling force. Specific examples of commercially available heavy stripping agents include KS-3800 and X-92-183 manufactured by Shin-Etsu Chemical Co., Ltd. and SDY7292, BY24-843 and BY24-4980 manufactured by Toray Dow Corning Co., Ltd. .. When the peeling force is to be lightly peeled off, various low-molecular-weight siloxanes are selected and the content of the release layer is adjusted appropriately so that the siloxane transfer component exhibits the release performance. Examples of low molecular weight siloxane compounds include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.
Other compounds of the former low molecular weight cyclic siloxane include trimethylsiloxy group-blocked dimethylsiloxane oligomers at both ends of the molecular chain and dimethylhydroxysiloxy group-blocked dimethylsiloxane oligomers at both ends of the molecular chain, and the compounds are mixed as necessary. You may use it. These low molecular weight siloxane compounds are usually contained in the silicone resin as a transition component in an amount of usually 0.1 to 15.0% by mass, preferably 0.1 to 10.0% by mass, and more preferably 0.1 to 5% by mass. Can achieve the desired light peeling. If the value is less than 0.1% by mass, the releasability may not be exhibited due to the small amount of the transferable component, and if the content of the low molecular weight siloxane is larger than 15.0% by mass, the transferability may not be exhibited. Excessive precipitation of sexual components may cause process contamination.

Further, it is preferable to use an organic silicon compound represented by the following general formula (3) in combination in the release layer in order to improve the adhesion between the release layer and the coating layer.
Si (X) _d (Y) _e (R ² ) _f ... (3)

In the above general formula (3), X is an organic group having at least one selected from an epoxy group, a mercapto group, a (meth) acryloyl group, an alkenyl group, a haloalkyl group and an amino group, and R ² is a monovalent hydrocarbon group. Yes, and have 1 to 10 carbon atoms, Y is a hydrolyzable group, d is an integer of 1 or 2, e is an integer of 2 or 3, f is an integer of 0 or 1, and d + e + f = It is 4.

The organic silicon compound represented by the general formula (3) has two hydrolyzable groups Y (D unit source) or three hydrolyzable groups Y (T unit) capable of forming a siloxane bond by a hydrolysis / condensation reaction. Source) can be used.

In the above general formula (3), the monovalent hydrocarbon group R ² has 1 to 10 carbon atoms, and a methyl group, an ethyl group, and a propyl group are particularly preferable.

In the above general formula (3), the following can be exemplified as the hydrolyzable group Y. That is, it is a methoxy group, an ethoxy group, a butoxy group, an isopropenoxy group, an acetoxy group, a butanoxim group, an amino group and the like. These hydrolyzable groups may be used alone or in combination of two or more. The application of a methoxy group or an ethoxy group is particularly preferable because it can impart good storage stability to the coating material and has appropriate hydrolyzability.

Specific examples of the organic silicon compound contained in the release layer include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 5-hexenyltrimethoxysilane, p- Examples thereof include styryltrimethoxysilane, trifluoropropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane.

The content of the organic silicon compound is preferably 0.5 to 5.0 parts by mass, preferably 0.5 to 2.0 parts by mass with respect to 100 parts by mass of the curable silicone resin. If the range is less than 0.5 parts by mass, it may be difficult to secure the desired adhesion, while if it exceeds 5.0 parts by mass, the adhesiveness to the resin layer to be bonded is too strong. , In the scene where it is originally necessary to peel off, problems such as not being able to peel off easily may occur.

The release agent composition forming the release layer includes a defoaming agent, a coatability improver, a thickener, an inorganic organic particle, an organic lubricant, an antistatic agent, a conductive agent, and an ultraviolet ray, if necessary. Absorbents, antioxidants, foaming agents, dyes, pigments and the like may be contained.

The release layer is formed by coating the film with the release agent composition, and even if it is provided by in-line coating performed in the film forming process, it is applied outside the system on the film once produced. , So-called off-line coating may be adopted.

As a method of providing the release layer on the coating layer of the film, a conventionally known coating method such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating and the like can be used.

The curing conditions for forming the release layer on the coating layer of the film are not particularly limited, and when the release layer is provided by offline coating, it is usually at 80 ° C. or higher for 10 seconds or longer, preferably 100 to 100. It is preferable to perform the heat treatment at 200 ° C. for 3 to 40 seconds, more preferably at 120 to 180 ° C. for 3 to 40 seconds. Further, if necessary, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination. As the energy source for curing by irradiation with active energy rays, a known device or energy source can be used.
From the viewpoint of coatability, the coating amount (after drying) of the release layer is usually 0.005 to 5 g / m ² , preferably 0.005 to 1 g / m ² , and more preferably 0.005 to 0. The range is 1 g / m ² .
If the coating amount (after drying) is less than 0.005 g / m ² , the stability may be less than that of coatability, and it may be difficult to obtain a uniform coating film. On the other hand, if the coating is thicker than 5 g / m ² , the coating film adhesion, curability, etc. of the release layer itself may decrease. The coating amount is calculated from the liquid mass per coating time (before drying), the non-volatile content concentration of the coating liquid, the coating width, the draw ratio, the line speed, and the like.

The antistatic layer may contain an electron conductive compound.
Examples of the electron-conductive organic compound include ammonium group-containing compounds, polyacetylene, polyphenylene, polyaniline, polypyrrole, polyisothianaften, polythiophene and the like. Among these, polythiophene, that is, a polymer obtained by singly or copolymerizing thiophene or a thiophene derivative can be mentioned.
In addition to the electron conductive compound, the antistatic layer contains polyalkylene oxide, glycerin, polyglycerin, and one or more compounds selected from the group of glycerin or alkylene oxide adducts to polyglycerin or derivatives thereof. You may.

When forming an antistatic layer by coating, the coating liquid includes, for example, a surfactant, other binder, particles, a defoamer, a coating improver, a thickener, an antioxidant, an ultraviolet absorber, and a foaming agent. , Dyes, pigments, etc. These additives may be used alone, or two or more thereof may be used in combination if necessary.
Further, the film may be subjected to chemical treatment, corona discharge treatment, plasma treatment or the like before coating.

The blocking prevention layer is a layer having an uneven surface, and the uneven surface may be a fine uneven surface or a surface having a flat portion and a raised portion.
The method for forming the uneven surface is not particularly limited, but for example, it is formed by containing particles in the resin composition forming the blocking prevention layer and / or phase-separating the resin composition forming the blocking prevention layer. obtain.
Examples of the resin used in the resin composition include a thermoplastic resin, a thermosetting resin, and an active energy ray-curable resin.
As the particles contained in the resin composition, for example, the above-mentioned particles can be used.

<Release film>
The thickness of the release film (hereinafter, also referred to as the release film of the present invention) in which the release layer is laminated on the coating layer of the laminated film of the present invention is particularly limited as long as it can be formed as a film. It's not something. Above all, it is in the range of 10 to 350 μm, more preferably 15 to 300 μm, and further preferably 20 to 250 μm from the viewpoint of mechanical strength, handleability, productivity and the like.

<Use of release film>
The release film of the present invention has good adhesion and aging adhesion between the release layer and the film, and is excellent in transparency. Therefore, for example, it is used for manufacturing and protecting various adhesive layers, and a liquid crystal display (liquid crystal display). In addition to manufacturing various display components such as polarizing plates and retardation plates used for LCDs), organic electroluminescence (hereinafter also referred to as organic EL) components, etc. It can be used as a release film suitable for optical applications.

<< Explanation of words >>
When expressed as "X to Y" (X, Y are arbitrary numbers) in the present specification, unless otherwise specified, they mean "X or more and Y or less" and "preferably larger than X" or "preferably Y". It also includes the meaning of "smaller".
Further, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it means "preferably larger than X" or "preferably less than Y". Including intention.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.
The measurement method and evaluation method used in this example are as follows.

(1) Extreme viscosity of polyester 1 g of polyester from which components incompatible with polyester have been removed is precisely weighed, 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (mass ratio) is added and dissolved, and the measurement is performed at 30 ° C. did.

(2) Average particle size (d50)
The particle size was measured using a centrifugal sedimentation type particle size distribution measuring device (SA-CP3 type) manufactured by Shimadzu Corporation, and the particle size with an integrated volume fraction of 50% in the equivalent spherical distribution was defined as the average particle size d50.

(3) Film thickness of coating layer The surface of the coating layer of the laminated film was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, a release layer cross-sectional transmission electron microscope (Hitachi High-Technologies Corporation H-7650, accelerating voltage 100 kV) was used for the measurement.

(4) Preparation of Release Film The following release agent composition is applied onto the coating layer of the laminated film by a reverse gravure coating method so that the coating amount (after drying) is 0.1 g / m ² , and the temperature is 140 ° C. , Heat treatment was performed for 20 seconds to obtain a release film.
<Release composition>
Addition-type cured silicone resin (KS-847H, manufactured by Shin-Etsu Chemical Co., Ltd.): 20 parts by weight Add-on platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.2 parts by weight Mixing of methyl ethyl ketone and toluene Solvent (mixing ratio 1: 1): 79.8 parts by weight

(5) Adhesion of release film to coating film over time (evaluation of practical characteristics substitute)
After adjusting the release film prepared in (4) under the following conditions 1 to 3, the surface of the release layer is rubbed 5 times with the finger pad of the second finger, and then the degree of detachment of the release layer is determined according to the following criteria. Judgment was made.
<Conditions>
Condition 1: Immediately after making the release film Condition 2: After leaving the release film in a constant temperature and humidity chamber under a 23 ° C x 50% RH atmosphere for 14 days Condition 3: Place the release film under a 23 ° C x 50% RH atmosphere After leaving in a constant temperature and humidity chamber for 30 days <Criteria>
○ (good): No dropout of the release layer was confirmed.
Δ (usual): The rubbed part became slightly white, and the release layer slightly fell off, but there was no problem in practical use.
× (poor): There is a problem in practical use because the rubbed part becomes white and the release layer easily falls off.

(6) Amount of change in film haze due to heat treatment 80 parts by weight of dipentaerythritol hexaacrylate, 20 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate, on the surface opposite to the coating layer side for measuring haze in the laminated film. A mixed coating solution of 5 parts by weight of a photopolymerization initiator (trade name: OMNIRAD184 (manufactured by IGM RESINS)) and 200 parts by weight of methyl ethyl ketone is applied so that the dry film thickness becomes 3 μm, and is cured by irradiating with ultraviolet rays to hard coat. A layer was formed. The haze of the film on which the hard coat layer was formed was measured from the coating layer side in accordance with JIS K 7136 using a haze meter (“HM-150” manufactured by Murakami Color Technology Research Institute Co., Ltd.).
Next, Kent paper was laminated and fixed on the hard coat layer side of the laminated film, and heat-treated by leaving it at 150 ° C. for 90 minutes in a nitrogen atmosphere. After the heat treatment, the Kent paper was removed from the laminated film, and the haze of the film was measured from the coating layer side by the same method as described above. The difference between the haze after the heat treatment and the haze before the heat treatment was calculated and used as the amount of change in the film haze.
The lower the amount of change in film haze, the smaller the amount of oligomer precipitates from the film due to high-temperature treatment, and in the case of polyester films, the smaller the amount of ester cyclic trimers precipitated, which is good.

The polyesters used in the examples and comparative examples are as follows.
<Polyester (A)>
A polyethylene terephthalate monopolymer having an ultimate viscosity of 0.63 dl / g.

<Polyester (B)>
A polyethylene terephthalate homopolymer containing 0.2% by weight of silica particles having an average particle size of 2 μm and having an ultimate viscosity of 0.65 dl / g.

Examples of compounds constituting the coating layer are as follows.
-Organic compounds containing metal elements: (A) Titanium lactate.

-Epoxy compound: (BI)
A glycerol polyglycidyl ether having an epoxy equivalent of 141 (g / eq).
-Epoxy compound (BII)
A glycerol polyglycidyl ether having an epoxy equivalent of 183 (g / eq).

-Polyvinyl alcohol: (C)
A polyvinyl alcohol having a degree of saponification of 88 mol% and a degree of polymerization of 500.

-Particles: (D) Silica sol having an average particle size of 65 nm.

Example 1:
Two extruded raw materials in which polyesters (A) and (B) are mixed at a ratio of 90% by mass and 10% by mass, respectively, as a raw material for the outermost layer (surface layer) and only polyester (A) as a raw material for an intermediate layer. After supplying each to the machine and melting at 285 ° C, each of them has a layer structure of 2 types and 3 layers (surface layer / intermediate layer / surface layer = 1: 8: 1 discharge amount) on a cooling roll set at 40 ° C. It was co-extruded and cooled and solidified to obtain an unstretched sheet. Next, after stretching 3.4 times in the longitudinal direction at a film temperature of 85 ° C. using the difference in roll peripheral speed, the coating liquid 1 shown in Table 1 below was applied to one side of the vertically stretched film and guided to a tenter. It was stretched 4.3 times at 110 ° C. in the transverse direction and heat-treated at 235 ° C., and then relaxed by 2% in the transverse direction to obtain a 50 μm-thick laminated film having a coating layer having a film thickness of 0.06 μm. .. The amount of change in film haze was evaluated for the obtained laminated film. The evaluation results are shown in Table 2 below.

A silicone release layer was formed on the coating layer of the obtained laminated film to obtain a release film. The release film obtained was evaluated for adhesion to the coating film over time. The evaluation results are shown in Table 2 below.

Examples 2-16:
A laminated film was obtained by manufacturing in the same manner as in Example 1 except that the composition of the coating liquid shown in Table 1 was changed. Further, a release film was obtained in the same manner as in Example 1.
The obtained laminated film and release film were evaluated for the amount of change in film haze and the adhesion of the coating film over time. The evaluation results are shown in Table 2 below.
The laminated films of Examples 12 and 13 using the coating liquids 9 and 10 containing polyvinyl alcohol in the coating liquid gave good results in the amount of change in film haze. It is presumed that this is because the addition of polyvinyl alcohol formed a denser coating layer and suppressed the precipitation of the ester cyclic trimer in the polyester film.

Comparative Example 1:
A film was obtained by manufacturing in the same manner as in Example 1 except that the coating layer was not provided. As shown in Table 2, the finished film was inferior in adhesion to the release layer over time.

Comparative Examples 2 and 3:
A laminated film was obtained by manufacturing in the same manner as in Example 1 except that the composition of the coating liquid shown in Table 1 was changed. Further, a release film was obtained in the same manner as in Example 1.
As shown in Table 2, the obtained laminated film and the release film were inferior in the adhesion of the release layer and the adhesion with time.

Comparative Example 2 is a compounding of an organic compound containing a metal element alone, and it was considered that a dense coating layer was formed, but the adhesion of the release layer and the adhesion with time were inferior, and particularly excellent oligomer precipitation suppression. It did not show any effect. In addition, the surface shape of the coating layer was not good.
The release film obtained in Comparative Example 3 was inferior in the adhesiveness of the release layer with time. Since this is a compounding of the epoxy compound alone, the cleavage reaction of the epoxy compound did not proceed sufficiently and the formation of hydroxyl groups was insufficient, so that it is presumed that the adhesiveness of the release layer with time was inferior.

The laminated film of the present invention has good adhesion to the release layer and adhesion over time, and has excellent transparency, and can be suitably used as a base material for the release film. In particular, production of various pressure-sensitive adhesive layers. -It can be used as a base film for a release film suitable for protective applications and various optical applications.

Claims (6)

A laminated film having a coating layer on at least one side of the film, wherein the coating layer is a layer formed of a coating liquid containing an organic compound containing a metal element and an epoxy compound. The laminated film according to claim 1, wherein the film is a polyester film. The laminated film according to claim 1 or 2, which contains polyvinyl alcohol in the coating liquid. The laminated film according to any one of claims 1 to 3, wherein the epoxy equivalent (g / eq) of the epoxy compound is 200 or less. A release film in which a release layer is laminated on a coating layer of the laminate film according to any one of claims 1 to 4. A method for producing a laminated film having a coating layer on at least one side of the film, wherein the coating layer is formed by coating a coating liquid containing an organic compound containing a metal element and an epoxy compound. Method.