JP2019115979A - Colored release film and laminate - Google Patents

Abstract

To provide a colored release film that is excellent in light detachability while being excellent in identifiability and discriminability.SOLUTION: Provided is a colored release film having an addition-type silicone release layer on at least one surface of a polyester film containing a colorant, characterized in that the polyester film has a laminate structure having at least a colored layer and a transparent layer and has a configuration in which the transparent layer is disposed between the colored layer and the addition-type silicone release layer.SELECTED DRAWING: None

Description

  The present invention relates to a colored release film suitable for a release film or the like of a double-sided pressure-sensitive adhesive sheet, and a laminate using the colored release film.

  In recent years, high performance of double-sided pressure-sensitive adhesive sheets is extremely rapid and is used in a wide range of fields. As one of them, cases used for building materials are increasing. For example, the case used at the time of air-tightening at the time of construction of a residence, the case used at the time of road repair, etc. are mentioned.

  Release films are provided on both sides of the double-sided pressure-sensitive adhesive sheet (the release film provided on one side is referred to as release film 1 and release film 2 provided on the other side) . The release film 1 and the release film 2 are often removed in order. This is because the function is provided to each surface of the double-sided pressure-sensitive adhesive sheet. If the order of peeling is reversed, there may be a case where it can not be attached well or a case where the required function of the double-sided pressure-sensitive adhesive sheet can not be exhibited. For this reason, in many cases, the mold release film 1 and the mold release film 2 are colored to be different colors or printed, and processing for discrimination is performed.

  In addition, the release film is often required to have a small peel strength, that is, a light peelability. The peeling force of the release film is determined by the adhesion to the double-sided pressure-sensitive adhesive sheet and the area to be peeled off. Therefore, as the area increases, the peeling force increases, and there is a possibility that the peeling can not be performed.

  A silicone resin is often used as a mold release agent to obtain a light release mold release film. The silicone resin is widely used as a mold release agent for products requiring light releasability because of its low surface free energy and requiring light releasability (Patent Document 1).

JP-A-5-194768

The silicone resin mainly includes condensation type silicone resin (condensation curing type) and addition type silicone resin (addition polymerization curing type), but in condensation type silicone resin, since a tin catalyst is used as a curing catalyst, the viewpoint of environmental problems It tends to be avoided from use.
For this reason, while using addition type silicone resin for a mold release layer and having light releasability, a mold release film excellent in distinction nature and distinction nature is desired. However, when a colored polyester film is used as a base material and a release layer using an addition type silicone resin is applied to the surface, there is a problem that the light release property can not be exhibited or the peeling force may not be stable. Was found.

  The present invention has been made in view of the above situation, and provides a colored release film excellent in discrimination and discrimination and excellent in light releasability, and a laminate using this release film. It will be an issue.

  MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in view of the said subject, the present inventors discover that the said subject can be highly solved by using the base film which has a specific laminated structure, and came to complete this invention.

  That is, the gist of the present invention is a colored release film having an addition-type silicone release layer on at least one surface of a polyester film containing a colorant, wherein the polyester film has at least a colored layer and a transparent layer. A colored release film having a laminated structure and having a configuration in which the transparent layer is disposed between the colored layer and the addition-type silicone release layer.

  The subject matter of the present invention also resides in a laminate obtained by laminating a double-sided pressure-sensitive adhesive sheet on the release layer surface of this colored release film.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in identification property and discrimination property, the laminated body using the colored release film excellent in light releasability and this release film is provided.

  Hereinafter, the present invention will be described in detail.

[Polyester film]
The polyester film (hereinafter sometimes referred to as "the polyester film of the present invention") to be a base film in the colored release film of the present invention has a laminated structure having a colored layer and a transparent layer. Furthermore, it is preferable that it is a laminated structure of three or more layers which have a colored layer in an intermediate | middle layer and have a transparent layer in both surfaces of this colored layer.

According to the inventor, when the polyester film has a single-layer structure, the coloring agent contained in the film in the process of forming the film bleeds out to the film surface (bleed out) and it sublimes It was found that the phenomenon occurred. On the other hand, it was found that the addition type silicone resin used for the release layer had a very delicate curing reaction, so that even when contacting with a small amount of coloring agent, curing did not proceed sufficiently due to inhibition of curing. . Therefore, it was found that when the base film is colored with a coloring agent, the curing reaction of the release layer does not proceed under the influence thereof, and the light peelability can not be achieved, or the peel force is not stable. In particular, such phenomena occur when organic dyes or pigments having functional groups, polarity, or ionicity are used as colorants, as compared to the case of chemically stable (inactive) colorants such as carbon black. It was also confirmed that the
It is well known that in the polyester film, an oligomer which is a low molecular weight polymer of polyester is present, and the oligomer bleeds out to the surface in the process of forming the film. Usually, in order to prevent bleed out of the oligomer, it is practiced to provide a curable coating layer on the surface. However, in order to prevent bleeding out of the coloring agent, it was found that in the oligomer, the cured layer (addition type silicone-based release layer) itself, which is a solution for preventing bleeding out, was damaged. .
From the above examination results, in the present invention, the polyester film has a laminated structure having at least a colored layer and a transparent layer, and a transparent layer is disposed between the colored layer and the addition silicone release layer. It is a solution.

<Polyester>
In the polyester film of the present invention, it is preferable that the polyester used in each of the laminated layers be obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, and aromatic dicarboxylic acid derivatives such as lower alkyl esters thereof. Examples of aliphatic glycols include ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol and the like.
Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like. Among these, PET has a good balance of physical properties and cost, and is the most commonly used polyester.

  The polyester used in the present invention may be a copolyester containing a third component. Examples of the dicarboxylic acid component of the copolyester include one or two or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid and sebacic acid, and as the glycol component, ethylene glycol And one or more kinds of diethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, polyethylene glycol and the like. 10 mol% or less is preferable, and, as for content of the structural unit derived from the said 3rd component with respect to all the structural units contained in co-polyester, More preferably, it is 5 mol% or less.

  The intrinsic viscosity of the polyester constituting the polyester film of the present invention is not particularly limited, but the intrinsic viscosity measured by the method described in the section of the examples described later is 0.60 to 0.75 dl / g, particularly 0. It is preferable that it is .60-0.70 dl / g.

<Colored layer>
The polyester film of the present invention has a laminated structure having a colored layer and a transparent layer. Furthermore, it is preferable that it is a structure which has a colored layer in the intermediate | middle layer of the laminated structure of three or more layers. A coloring agent is contained in this colored layer, and the "layer containing a coloring agent" and "colored layer" are synonymous. Although the said coloring agent is not limited, It is preferable to have absorption in visible light region (380-780 nm). In addition, the compound which has absorption in an ultraviolet light area | region and an infrared light area | region can also be included in the coloring agent in this invention, as long as the effect of this invention is show | played.

  The colored release film of the present invention is in the state already colored by the colored layer. Therefore, since it is not necessary to provide separately a printing layer in manufacturing a colored film, simplification of a manufacturing process is possible. In addition, it does not exclude providing a printing layer in the colored release film of this invention. Moreover, the colored layer in the present invention does not have to be uniform, and may be a colored layer having a printing function.

Although the coloring agent used by this invention is not limited, It is preferable to melt | dissolve in polyester substantially. The term "substantially dissolve" as used herein means that when kneading is performed in the molten state of the polyester, the aggregates are uniformly mixed without leaving any aggregates or the like. If the aggregates and the like remain, color unevenness may occur in the polyester film.
Further, the colorant is preferably one that is less decomposed at the molding temperature of the polyester. Among them, the coloring agent is preferably a dye, and in terms of chemical structure, anthraquinone type, perinone type, perylene type, isoquinoline type, azomethine type, heterocyclic type dyes and the like are more preferable. For dyeing prescription, dispersible dyes and oil-soluble dyes are more preferable.

Moreover, even if coloring agents are generally classified as pigments, as long as they can be dissolved in molten polyester as described above, they can be used as coloring agents. Examples of such colorants include phthalocyanine dyes and complex dyes with metal ions such as copper, cobalt, nickel, zinc and chromium.
The coloring release film of the present invention has a specific layer constitution, so that the coloring agent can be used even if the organic dye or pigment having such functional group, polarity, or ionic property is used as the coloring agent. It does not inhibit the curing reaction of the addition-type silicone release layer, and can exhibit good light releasability and stability of releasability.

  The colored layer of the polyester film of the present invention may contain a known ultraviolet absorber, radical trap agent, etc. in addition to the above-mentioned colorant, but in this case, even if these additives are added, the film becomes cloudy. It is preferable to select and use those which do not produce.

  The method of adding the coloring agent and other additives to the polyester may be a method of adding them as powder, paste or liquid when melt-forming the film, but in consideration of the problem of apparatus contamination, It is preferable to prepare a polyester masterbatch containing a coloring agent and the like, and add the masterbatch while diluting it with a clear resin (polyester not containing a coloring agent) at the time of melt molding of the film. In addition, it is preferable to use a twin-screw extruder, in particular, in order to add and knead the colorant to polyester in a highly dispersed manner during the melt-molding.

The content of the coloring agent in the colored layer also differs depending on the thickness of the colored layer, the type of the coloring agent to be used, and the concealing ability, light shielding ability, and the required discriminating ability. The lower limit of the colorant content in the colored layer is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.4% by mass or more, particularly preferably Is 1.0 mass% or more. When the content of the coloring agent in the colored layer is less than the above lower limit, the coloring by the coloring agent can not be sufficiently obtained, and it is difficult to determine the difference from the non-colored film not containing the coloring agent. On the other hand, the upper limit of the colorant is preferably 10% by mass or less, more preferably 5% by mass or less. If the above upper limit is exceeded, the colorant becomes a foreign matter and a colored layer, which may cause problems during film formation.
In addition, only 1 type may be used for a coloring agent and 2 or more types may be mixed and used. When two or more colorants are used, the total colorant content is preferably in the above range.

<Transparent layer>
The polyester film of the present invention has, in addition to the colored layer, a transparent layer which is a polyester film layer containing no colorant, and is disposed between the colored layer and the releasing layer. By having the transparent layer, bleeding out of the coloring agent contained in the colored layer can be prevented. Furthermore, it is preferable to have a transparent layer on both sides of the colored layer. By having the transparent layer on both sides of the colored layer, it is possible not only to bleed out the coloring agent but also to improve the contamination of the film forming machine, and the coatability and post-processability on the opposite side of the release layer. .
In the laminated structure of the polyester film of the present invention, the transparent layer is preferably a surface layer.

  The transparent layer of the polyester film of the present invention may contain particles under conditions that do not impair the transparency in order to facilitate handling. Examples of particles used in the present invention include calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, inorganic particles such as molybdenum sulfide, and crosslinked polymers Examples of such particles include particles and organic particles such as calcium oxalate. These may use only 1 type and may use 2 or more types together.

  The average particle size of the particles used is usually 0.02 to 5.0 μm, preferably 0.05 to 4.0 μm. When the average particle size is larger than 5.0 μm, the haze of the film may be too large, and the transparency of the transparent layer may be reduced. The release film of the present invention is colored, but the haze of the transparent layer is preferably low. If the average particle size is smaller than 0.02 μm, the surface roughness can not be sufficiently increased, and the effect of improving the handleability of the film may not be obtained. In addition, the average particle diameter of particle | grains here is a value of the average particle diameter which disperse | distributed with a solvent and was measured by refractive index.

When the polyester film of the present invention contains particles, the content is generally 0.001 to 0.5% by mass, preferably 0.01 to 0.3% by mass, based on the entire laminated polyester film. The content of particles in the one transparent layer is not particularly limited, but is preferably 0.001 to 3% by mass. When the particle content is in the above-mentioned range, it is possible to ensure the minimum necessary slip without increasing the haze and it is preferable.
Moreover, it is preferable to make average surface roughness Ra of the film surface of the polyester film of this invention into the range of 0.005-0.050 micrometer by containing particle | grains.

  Furthermore, it is also possible to add well-known additives, such as an infrared absorber and a ultraviolet absorber, to the transparent layer of the polyester film of this invention as needed.

<Thickness>
In the polyester film of the present invention, the thickness of the transparent layer is usually 1.0 μm or more regardless of the thickness of the entire polyester film in order to surely prevent the bleeding out of the additive such as the coloring agent present in the colored layer. Preferably it is 1.5 micrometers or more, More preferably, it is 2.0 micrometers or more. The upper limit of the thickness of the transparent layer is not limited, but is usually 40 μm or less, preferably 30 μm or less, and more preferably 10 μm or less.
Moreover, the thickness of each layer in the case of providing a transparent layer on both sides of a colored layer may be the same or different, but when the thickness of the transparent layer is different, each thickness of the transparent layer is within the above thickness range Is preferred.

  The thickness (total thickness of the laminated polyester film) of the polyester film of the present invention is preferably 15 to 125 μm, particularly 25 to 100 μm, from the viewpoint of film handleability.

  The thickness of the colored layer is not particularly limited. As described above, the thickness of the transparent layer is preferably 1.0 μm or more from the viewpoint of preventing bleeding out of the coloring agent and the like.

[Release layer]
In the colored release film of the present invention, at least one outermost layer is an addition-type silicone release layer in order to exhibit light releasability. In the present invention, the addition type silicone release layer means a layer containing an addition type silicone resin as a main component. Here, the main component means 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more. The upper limit of the content ratio of the addition-type silicone resin contained in the addition-type silicone release layer is 100% by mass. Here, the content of the catalyst is excluded.

  The addition-type silicone release layer is a cured layer of a composition containing an addition-type silicone resin (hereinafter, may be referred to as “a composition for forming a release layer”). Here, the addition type silicone resin to be used is not particularly limited. Further, the addition type silicone resin may be of a type having itself as a main component, or may be a modified silicone type by graft polymerization with an organic resin such as a urethane resin, an epoxy resin, or an alkyd resin.

  The addition type silicone resin is composed of a polyorganosiloxane containing an alkenyl group as a functional group in the molecule (alkenyl group-containing silicone) and a polyorganosiloxane containing a hydrosilyl group as a functional group in the molecule. Is preferred.

  Among polyorganosiloxanes containing an alkenyl group as a functional group in the molecule, among these, polyorganosiloxanes having two or more alkenyl groups in the molecule are preferable. As said alkenyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), a butenyl group, pentenyl group, a hexenyl group etc. are mentioned, for example, Especially, a vinyl group and a hexenyl group are preferable. The above-mentioned alkenyl group is usually bonded to a silicon atom (for example, a silicon atom at a terminal end, a silicon atom inside the main chain, etc.) of a polyorganosiloxane forming a main chain or a side chain.

  Moreover, as polyorganosiloxane which forms the said principal chain or side chain, in addition to polyalkyl alkyl siloxane, polyalkyl aryl siloxanes, such as polydimethylsiloxane, polydiethylsiloxane, polymethylethyl siloxane etc., a silicon atom content is mentioned, for example The copolymer (for example, poly (dimethylsiloxane-diethyl siloxane) etc.) etc. in which multiple types of monomer components are used are mentioned. Among these, polydimethylsiloxane is preferable in that stable releasability can be obtained. Specific examples of the polyorganosiloxane containing an alkenyl group as a functional group in the molecule preferably include a polydimethylsiloxane having a vinyl group as a functional group, a polydimethylsiloxane having a hexenyl group as a functional group, and a mixture thereof. Be done.

  On the other hand, a polyorganosiloxane containing a hydrosilyl group as a functional group in the molecule is a polyorganosiloxane having a hydrogen atom (in particular, a silicon atom having a Si-H bond) bonded to a silicon atom in the molecule. In particular, polyorganosiloxanes having two or more silicon atoms having Si-H bond in the molecule are preferable. The silicon atom having a Si-H bond may be either a silicon atom in the main chain or a silicon atom in the side chain, that is, it may be contained as a constituent unit of the main chain, side chain May be included as a constituent unit of The number of silicon atoms in the Si—H bond is not particularly limited as long as it is two or more. Specifically as a polyorganosiloxane which contains a hydrosilyl group as a functional group in the said molecule | numerator, polymethyl hydrogen siloxane, poly (dimethylsiloxane-methyl hydrogen siloxane), etc. are suitable.

  A commercially available product may be used as the addition type silicone resin, and specific examples thereof include KS-774, KS-775, KS-778, KS-779H, KS-847H, and KS-856 manufactured by Shin-Etsu Chemical Co., Ltd. DKQ 3-202, DKQ 3-203, DKQ 3-204, DKQ 3-205, DKQ 3-210 manufactured by Dow Corning Asia Ltd. YSR-3022 manufactured by Toshiba Silicone Co., Ltd. TPR-6700, TPR-6720, TPR-6721, LTC300B manufactured by Toray Dow Corning, LTC303E, LTC310, LTC314, SRX357, BY24-749, SD7333, BY24-179, BY24-840, BY24-842, BY24- 850, SP7015, SP7259 SD7220, SD7226, SD7229, and the like.

  A release control agent may be used in combination with the addition silicone resin as described above in order to adjust the release property and the like of the release layer to be formed.

  In order to accelerate the reaction of the addition-type silicone resin to form a release layer, a catalyst is usually used to form a clean and robust release layer. The type of catalyst used is not particularly limited, but a platinum catalyst is preferably mentioned. Examples of platinum catalysts include chloroplatinic acid, alcohol solutions of chloroplatinic acid, complexes of chloroplatinic acid and olefin, platinum-based compounds such as complexes of chloroplatinic acid and alkenyl siloxane, platinum black, platinum-supported silica, platinum-supported activated carbon Etc. are illustrated.

  Further, since the addition type silicone resin is very reactive, in some cases, an addition reaction inhibitor such as acetylene alcohol may be added to the composition for forming a release layer. The addition reaction inhibitor is an organic compound having a carbon-carbon triple bond and a hydroxyl group, preferably 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol and It is a compound selected from the group consisting of phenylbutynol.

  The addition type silicone-based release layer in the present invention may contain a release agent other than the addition type silicone resin. Although release agents other than addition type silicone resin are not limited, For example, condensation type silicone resin, a polyolefin type release agent, a fluorine resin type release agent etc. are mentioned. The release force can also be adjusted by containing a release agent other than the addition silicone resin in the addition silicone release layer. The content ratio of the release agent other than the addition type silicone resin is usually 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, further preferably 10% by mass in the addition type silicone release layer. % Or less. The lower limit of the content ratio when using a release agent other than the addition type silicone resin is usually 1% by mass or more.

  The release layer may be formed only on one side of the polyester film of the present invention, or may be formed on both sides. In addition, when forming a mold release layer on both surfaces of a polyester film, it is preferable that it is a structure of the polyester film which has a transparent layer on both surfaces of a colored layer.

  The release layer is preferably formed by a coating method described later at a preferable coating amount described later.

<Other layer, surface treatment>
In the present invention, another coated layer such as an adhesive layer, an antistatic layer or an oligomer deposition preventing layer may be provided on the surface of the polyester film not provided with the release layer.
The polyester film may be subjected to surface treatment such as corona treatment or plasma treatment prior to the formation of the release layer and these layers.

[Method for producing colored release film]
Next, although the manufacturing method of the colored release film of this invention is demonstrated concretely, the manufacturing method of the colored release film of this invention is not limited at all to the following manufacture examples.

  As a method for producing the polyester film of the present invention to be a base film, the polyester raw material is laminated by using multiple extruders, multiple layers of multi manifold die or feed block, laminating each polyester and melting multiple layers from a die The method of extruding a sheet and cooling and solidifying it with a cooling roll to obtain an unstretched sheet, that is, the co-extrusion method is preferred. In this case, in order to improve the planarity of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and it is preferable to adopt the electrostatic application adhesion method and / or the liquid application adhesion method.

  The polyester film of the present invention may be unstretched, but is preferably a stretched film, and particularly preferably biaxially oriented and heat-fixed by being stretched in the biaxial direction. Either a sequential biaxial stretching method or a simultaneous biaxial stretching method may be used as a stretching method. For example, when using a sequential biaxial stretching method, first, the unstretched sheet is rolled in the machine direction (longitudinal direction) It is drawn by a drawing 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. Next, stretching is performed in the width direction (lateral direction). The stretching temperature is usually 70 to 120 ° C., preferably 80 to 115 ° C., and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or relaxation within 30% to obtain a biaxially stretched film.

  In the said extending | stretching, the method of allocating extending | stretching to two or more steps and setting it as a predetermined draw ratio other than the method of extending | stretching to predetermined magnification by one draw operation can also be used. Also in that case, it is preferable to carry out so that the draw ratio of two directions finally becomes the said range, respectively. Furthermore, it may be stretched in the longitudinal and / or transverse direction again before or after heat treatment, if necessary.

  A subbing layer may be provided on the surface of the polyester film of the present invention for the purpose of improving the adhesion with the release layer. The subbing layer may be formed by coating on a polyester film which has been subjected to biaxial orientation and then heat-fixed to complete crystal orientation, but the polyester film is formed during film formation, particularly in the machine direction (longitudinal direction) At the end of stretching), a coating agent diluted with a solvent mainly containing water is applied, and then, in lateral stretching and heat setting, oriented crystallization of the polyester film and application of the undercoat layer by drying of the coating agent It is more preferable to apply by the method of using what is called in-line coating which performs at the same time.

As a method of applying the composition for forming a release layer to the polyester film of the present invention and providing a release layer, a conventionally known coating method such as reverse roll coating, gravure coating, bar coating, doctor blade coating, etc. may be used. Can. The application of the composition for release layer formation may be either in-line coating or off-line coating. The application amount of the composition for release layer formation is usually in the range of 0.01 to 1 g / m ² as the application amount after drying.

  Drying and curing of the coating of the release layer-forming composition can be carried out individually or simultaneously. As temperature conditions, 80 degreeC or more, for example, 100-180 degreeC, is preferable. By carrying out at 80 degreeC or more, hardening of a coating film advances sufficiently and it can suppress drop-off | omission of a coating film. The curing time is preferably 10 seconds or more, for example, 20 to 90 seconds, from the viewpoint of curing of the coating.

  When the release layer is provided as the outermost layer, the surface of the polyester film of the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in advance as described above. If necessary, heat treatment and active energy ray irradiation such as ultraviolet ray irradiation may be used in combination.

[Physical Properties of Colored Release Film]
<Visible light transmittance>
The visible light transmittance of the colored release film of the present invention is preferably 3 to 90%, and more preferably 5 to 80%. When the visible light transmittance is 3% or more, it is possible to obtain good intelligibility and distinguishability by coloring. If the visible light transmittance exceeds 90%, the color may not be visible when the film is used alone.
The visible light transmittance of the colored release film is measured by the method described in the section of Examples described later.

<Normal peeling force>
The release layer of the colored release film of the present invention is preferably light releasable, and the normal state releasability is preferably 50 mN / cm or less, more preferably 40 mN / cm or less, and still more preferably 35 mN / cm or less. In the case where the normal peeling force exceeds 50 mN / cm, the release film may not be manually peeled off when construction is performed due to the increase in area. The lower limit of the normal peeling force is usually 10 mN / cm or more.

  Here, with normal-state peeling force, a double-sided pressure-sensitive adhesive tape (Nitto Denko Co., Ltd., No. 502) is attached to the surface of the release layer of the colored release film and left for 1 hour at room temperature. The value measured with a tensile tester when peeling off the tape at a speed. The specific method of measuring the normal peeling force is as described in the section of Examples described later.

  As a method of adjusting the peeling force of the colored release film of the present invention, it is a condition that the release layer contains an addition type silicone resin, but the method is not particularly limited to the other methods. As a method of adjusting the peeling force, methods of adjusting the type and coating amount of the addition type silicone resin which is a release agent mainly used for the addition type silicone-based release layer, the thickness of the release layer, and the like can be mentioned.

<Heat peeling force>
125 mN / cm or less is preferable and, as for the heat-peeling force of a colored release film, 100 mN / cm or less is more preferable. The lower limit of the heat peeling force is usually 10 mN / cm or more. Here, the heat peeling force is obtained by sticking a double-sided pressure-sensitive adhesive tape (Nitto Denko Co., Ltd., No. 502) on the surface of the colored release film and leaving it in an oven at 100 ° C. for 1 hour. C), it means the value measured by a tensile tester when the tape is peeled off at a peeling angle of 180 ° and an arbitrary tensile speed. A specific measurement method of the heat peeling force is as described in the section of Examples described later.

<Heating peeling force / normal peeling force ratio>
In the colored release film of the present invention, the ratio of the heat release force to the normal condition release force (heat release force / normal condition release force) is preferably 2.5 or less, more preferably 2.0 or less.
Usually, heating the release film causes a change in peel force. One factor that changes the heat peeling force is that the release layer is not sufficiently cured. When the ratio of the heat peeling force to the normal state peeling force exceeds 2.5, there is a possibility that the release layer is not sufficiently cured, and there is a possibility that a defect in which the silicone resin falls off from the polyester film may occur. The lower limit of the heat peeling force / normal state peeling force ratio is preferably 1.0 or more.
The colored release film of the present invention can inhibit the curing inhibition of the release layer by the coloring agent, so that the curing reaction of the release layer can be completed, and the change between the heat release force and the normal release force is It can be suppressed.

[Double-sided adhesive sheet]
Although the usage method of the colored release film of this invention is not limited, It can use suitably as a double-sided adhesive sheet on which the adhesive layer was laminated | stacked.
The material which comprises an adhesive layer is not limited, A well-known adhesive can be used.

  When the release film is laminated on both sides of the double-sided pressure-sensitive adhesive sheet, the colored release film of the present invention may be used as the release film on both sides, but one side is the colored release film of the present invention. The other surface is preferably a release film containing no colored layer, as described above, in order to distinguish the release film 1 from the release film 2. When the release force of the release film 1 and the release film 2 are different, it is optional whether the colored release film of the present invention is used as the release film, but the release film of the present invention is stable Since it has light peelability, it can be suitably used on the side with low peel strength.

  EXAMPLES The present invention will be described in more detail by way of Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

[Evaluation of physical properties and characteristics]
In the following, various physical properties and characteristics are measured or defined as follows.

(1) Measurement of Intrinsic Viscosity of Polyester 1 g of polyester from which a coloring agent was removed was precisely weighed, and 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (mass ratio) was added and dissolved, and measured at 30 ° C.

(2) Visible light transmittance With respect to the sample film, the light transmittance of each wavelength 380 to 780 nm is measured with a D65 light source using a spectrocolorimeter (SE-2000 manufactured by Nippon Denshoku Co., Ltd.), according to JIS-S3107 The visible light transmittance was calculated.

(3) Normal State Peeling Force An adhesive tape (Nitto Denko Co., Ltd., No. 502) was attached to the surface of the release layer of the sample film, and the peeling force after standing for 1 hour at room temperature was measured. The peeling force was measured by performing 180 ° peeling under a tensile speed of 300 mm / min using a tensile tester (Intesco Corporation, Intesco model 2001 type).

(4) Heat Peeling Force A pressure-sensitive adhesive tape (Nitto Denko Co., Ltd., No. 502) is attached to the surface of the release layer of the sample film, and left in an oven heated to 100 ° C for 1 hour, cooled to room temperature (23 ° C) Peeling force was measured. The peeling force was measured by performing 180 ° peeling under a tensile speed of 300 mm / min using a tensile tester (Intesco Corporation, Intesco model 2001 type).

(5) Love-off test (utility characteristic substitute evaluation)
After leaving the sample film in a room at 23 ° C. and 50% RH for 30 days, the surface of the release layer was rubbed with a finger several times. The condition of the surface of the release layer after rubbing was evaluated according to the following judgment criteria.
Judgment criteria
○: No change was observed on the surface of the mold release layer (good in practical use)
X: A mark of rubbing with a finger was found on the surface of the release layer (there is a problem in practical use)

(6) Film discrimination test (utility characteristic substitute evaluation)
A sample film and a general-purpose release film (Diafoil MRF25, manufactured by Mitsubishi Chemical Corporation) were prepared. Ten testers were randomly selected to select a colored film. The following judgment criteria evaluated whether it was distinguishable.
Judgment criteria
○: 10 out of 10 selected the sample film (very high discrimination performance)
Δ: 8 to 9 out of 10 selected the sample film (with discrimination ability)
X: 7 or less out of 10 selected the sample film (no discrimination performance)

(7) Peeling test (utility characteristic substitution evaluation)
The acrylic pressure-sensitive adhesive composition prepared as described below was applied to the surface of the release layer of the sample film, and then heat treated at 100 ° C. for 5 minutes to form a pressure-sensitive adhesive layer having a thickness (after drying) of 150 μm. Next, the adhesive layer surface was stuck on a glass plate, and the following judgment criteria evaluated whether it was possible to peel off with a human hand.
<Acrylic pressure-sensitive adhesive composition>
(Monomer mixture)
2-ethylhexyl acrylate: 70% by mass
Acrylic acid 2-methoxyethyl: 29% by mass
Acrylic acid 4-hydroxybutyl: 1% by mass
An acrylic pressure-sensitive adhesive composition was prepared by adding 0.1 parts by mass of polyisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by mass of the above-mentioned monomer mixture.
Judgment criteria
○: Easy to peel off (no problem in practical use)
X: can not be easily peeled off (there is a problem in practical use)

(8) Comprehensive Evaluation A comprehensive evaluation was performed on each evaluation item of the love-off test, the film discrimination test, and the peel test according to the following judgment criteria.
Judgment criteria
○: All the rub off test, film discrimination test, peeling test are ○ or △
X: at least one of the rub off test, the film discrimination test, and the peeling test is x

[Production of polyester]
The polyesters used in the examples and comparative examples were produced as follows.

<Polyester A>
In a reactor, 100 parts by mass of dimethyl terephthalate, 60 parts by mass of ethylene glycol and 0.09 parts by mass of magnesium acetate tetrahydrate are heated and heated while distilling off methanol to carry out a transesterification reaction for 4 hours from the start of the reaction The temperature was raised to 230 ° C. to substantially complete the transesterification reaction. Then, after adding 0.04 parts by mass of ethyl acid phosphate and 0.04 parts by mass of antimony trioxide, the temperature is adjusted to 280 ° C. and the pressure to 15 mmHg in 100 minutes, and the pressure is gradually reduced thereafter and finally It was 0.3 mmHg. After 4 hours, the inside of the system was returned to normal pressure to obtain polyester A substantially free of fine particles. The intrinsic viscosity of polyester A was 0.70 dl / g.

<Polyester B>
After completion of the transesterification reaction, an ethylene glycol slurry containing 2.0 parts by mass of silica particles having an average particle diameter of 1.4 μm is added, and further 0.04 parts by mass of ethyl acid phosphate and 0.04 parts by mass of antimony trioxide The polyester B was manufactured by the same method as that of the polyester A except that. The silica particle content of the obtained polyester B was 1.0% by mass. The intrinsic viscosity of polyester B was 0.70 dl / g.

<Polyester C>
After completion of the transesterification reaction, polyethylene glycol having a molecular weight of 6000 (containing 0.3% by mass of antioxidant) is added as an ethylene glycol solution, and further 0.04 parts by mass of ethyl acid phosphate and 0.04 parts of antimony trioxide A polyester C was produced in the same manner as polyester A except that part was added. The intrinsic viscosity of polyester C was 0.70 dl / g.

<Polyester D>
The polyester A is subjected to a vented twin-screw extruder, and 3.0% by mass of Diaresin Red HS (Mitsubishi Chemical Co., Ltd., perinone dye), and Diaresin Blue H3G (Mitsubishi Chemical Co., anthraquinone dye) 5 .5% by mass, and Dieresin Yellow F (Mitsubishi Chemical Co., Ltd., isoquinoline dyestuff) are mixed and added so as to have respective concentrations of 1.5% by mass, and melt kneading is carried out to chip the dye Polyester D was made as a masterbatch.

<Polyester E>
Polyester A is subjected to a vented twin-screw extruder, and 1.0% by mass of Diaresin Red HS (Mitsubishi Chemical Co., Ltd., Perinone-based dye), and Diaresin Blue H3G (Mitsubishi Chemical Co., anthraquinone-based dye) 5 .5% by mass and Diaresin Yellow F (Mitsubishi Chemical Co., Ltd., isoquinoline dyestuff) are mixed and added so as to have each concentration of 3.5% by mass, and melt kneading is carried out to chip the dye Polyester E was made as a masterbatch.

[Composition for Release Layer Formation]
In the formation of the release layer in the following examples and comparative examples, a mixture in which the non-volatile component is blended according to the formulation shown in the following Table 1 as a composition for forming a release layer is a toluene / methyl ethyl ketone mixed solvent (mixing ratio is 1: Coating solutions 1 to 3 prepared by dilution in 1) were used.
(A1) Addition type silicone resin (KS-847H: made by Shin-Etsu Chemical Co., Ltd.)
(A2) Addition type silicone resin (LTC303E: made by Toray Dow Corning)
(B1) Heavy release control agent (SD-7292: Toray Dow Corning)
(C1) Platinum catalyst (PL-50T: Shin-Etsu Chemical Co., Ltd.)

[Production of polyester film]
The polyester films used in the following examples and comparative examples were produced as follows.

<Production of polyester film F1>
A mixture in which polyesters A and D were mixed at a mass ratio of 78:22 as an intermediate layer was introduced into the extruder as an intermediate layer resin. Further, a mixture of polyesters A, B, and C mixed at a mass ratio of 77:10:13 as the surface layer on both surfaces of the intermediate layer was introduced into the extruder as a surface layer resin. Each of the extruders was a bi-directional double-screw extruder with a vent, and the resin was extruded at a melting temperature of 290 ° C. without drying, and then the molten polymers were merged and laminated in a feed block. Then, it solidified by cooling on the cooling roll which set surface temperature to 40 degreeC using the electrostatic application adhesion method, and obtained the lamination | stacking unstretched sheet of 3 layer structure.

The obtained laminated unstretched sheet was stretched at 83 ° C. in the machine direction (longitudinal direction) 3.6 times. The film was further introduced into a tenter, dried and preheated at 93 ° C., and then stretched 3.8 times in the width direction (lateral direction), and heat setting was performed at 225 ° C. Furthermore, 5% relaxation treatment was performed at 185 ° C. in the width direction to obtain a polyester film F1.
The polyester film F1 is a three-layer laminate film in which the intermediate layer is a colored layer and the surface layer is a transparent layer, the thickness of each layer is 2 μm / 21 μm / 2 μm, and the total thickness is 25 μm.

<Production of polyester film F2>
As an intermediate | middle layer, except changing polyester D into polyester E, it manufactured by the method similar to the polyester film F1, and obtained the polyester film F2.

<Production of polyester film F3>
A polyester film F3 was obtained by the same method as polyester film F1 except that polyesters A and D used in the intermediate layer were mixed at a weight ratio of 90:10.

<Production of polyester film F4>
A polyester film F4 was produced in the same manner as the polyester film F1 except that polyesters A and D used in the intermediate layer were mixed at a weight ratio of 95.5: 4.5.

<Production of polyester film F5>
A mixture obtained by mixing polyesters A, B, and C at a weight ratio of 77.0: 10.0: 13.0 as an intermediate layer was introduced into the extruder as an intermediate resin. Moreover, the mixture which mixed polyester A and D by mass ratio of 78:22 as surface layer was thrown into the extruder as resin for surface layers.
Except the above, it manufactured by the method similar to polyester film F1, and obtained polyester film F5.
The polyester film F5 is a three-layer laminate film in which the intermediate layer is a transparent layer and the surface layer is a colored layer, the thickness of each layer is 2 μm / 21 μm / 2 μm, and the total thickness is 25 μm.

<Production of polyester film F6>
It manufactured by the method similar to polyester film F5 except changing polyester D into polyester E as surface layer, and obtained polyester film F6.

<Production of polyester film F7>
It manufactured by the method similar to the polyester film F1 except having used 100 mass% of polyester A as an intermediate | middle layer, and obtained polyester film F7.
The polyester film F7 was a three-layer laminated film in which all layers were transparent layers.

Example 1
On the surface layer of a 25 μm-thick polyester film F1 as a composition for forming a release layer, the reverse gravure coat method is performed off-line so that the coating amount after drying of the coating liquid 1 is 0.1 g / m ² After coating, the coating was dried by heating at 150 ° C. for 30 seconds and cured to form a release layer. The properties of the obtained release film are shown in Table 2.

Example 2
A release film was obtained in the same manner as in Example 1 except that the polyester film F1 was changed to a polyester film F2. The properties of the obtained release film are shown in Table 2.

[Example 3]
A release film was obtained in the same manner as in Example 1 except that the coating solution 1 was changed to the coating solution 2. The properties of the obtained release film are shown in Table 2.

Example 4
A release film was obtained in the same manner as in Example 1 except that the coating solution 1 was changed to the coating solution 3. The properties of the obtained release film are shown in Table 2.

[Example 5]
A release film was obtained in the same manner as in Example 4 except that the polyester film F1 was changed to a polyester film F2. The properties of the obtained release film are shown in Table 2.

[Example 6]
A release film was obtained in the same manner as in Example 4 except that the polyester film F1 was changed to a polyester film F3. The properties of the obtained release film are shown in Table 2.

[Example 7]
A release film was obtained in the same manner as in Example 1 except that the polyester film F1 was changed to a polyester film F4. The properties of the obtained release film are shown in Table 2.

Comparative Example 1
A release film was obtained in the same manner as in Example 1 except that the polyester film F1 was changed to a polyester film F5. The properties of the obtained release film are shown in Table 3. Since the surface layer of the polyester film F5 was a colored layer, the curing of the release layer was insufficient due to the inhibition of curing by the colorant, and the rub-off test failed.

Comparative Example 2
A release film was obtained in the same manner as in Example 1 except that the polyester film F1 was changed to a polyester film F6. The properties of the obtained release film are shown in Table 3. Since the surface layer of the polyester film F6 was a colored layer, the curing of the release layer was insufficient due to the inhibition of curing by the colorant, and the rub off test was rejected.

Comparative Example 3
A release film was obtained in the same manner as in Example 1 except that the polyester film F1 was changed to a polyester film F7. The properties of the obtained release film are shown in Table 3. Since all the layers of the polyester film F7 were transparent layers, the film discrimination test failed.

Claims (5)

  A colored release film having an addition-type silicone release layer on at least one surface of a polyester film containing a colorant, wherein the polyester film has a laminated structure having at least a colored layer and a transparent layer, A colored release film characterized in that the transparent layer is disposed between the colored layer and an addition silicone release layer.   The colored release film according to claim 1, wherein the polyester film has a laminated structure of three or more layers having a colored layer as an intermediate layer and transparent layers on both sides thereof.   The colored release film according to claim 1, wherein the coloring layer contains 0.01% by mass or more of a coloring agent.   The colored release film according to any one of claims 1 to 3, wherein the coloring agent is at least one selected from anthraquinone type, perinone type, perylene type, isoquinoline type, azomethine type, and heterocyclic ring type.   The laminated body in which a double-sided adhesive sheet is laminated | stacked on the release layer surface of the colored release film in any one of Claims 1-4.