WO2016152369A1

WO2016152369A1 - Mold release film

Info

Publication number: WO2016152369A1
Application number: PCT/JP2016/055619
Authority: WO
Inventors: 太朗鈴木
Original assignee: 三菱樹脂株式会社
Priority date: 2015-03-23
Filing date: 2016-02-25
Publication date: 2016-09-29
Also published as: KR20170099980A; KR101998239B1; TWI752902B; CN107428135A; TW201704011A; CN107428135B

Abstract

Provided is a mold release film which has good releasability from an adhesive and is extremely suppressed in oligomer precipitation, while being suppressed in migration, and which is suitable for various adhesive layer protection applications for the production of a capacitive touch panel, the production of LCD constituent members such as a polarizing plate and a retardation film used for a liquid crystal display (LCD), the production of a plasma display panel constituent member, the production of an organic electroluminescent display constituent member, the production of various display constituent members, and the like. A mold release film that is characterized by having a silicone-based mold release layer, which is formed from a coating liquid containing a reactive silicone resin having a functional group, an unreactive silicone resin and a platinum-based catalyst, on one surface of a polyester film.

Description

Release film

The present invention is particularly suitable for applications where light peeling is required for protecting various pressure-sensitive adhesives, and the amount of oligomer precipitation is extremely small. For example, for the production of capacitive touch panels, the adhesive layer is attached via a pressure-sensitive adhesive layer. Various applications, for manufacturing liquid crystal display (hereinafter abbreviated as LCD) polarizing plate, retardation plate and other LCD structural members, plasma display panel (hereinafter abbreviated as PDP) structural members, organic electroluminescence The present invention relates to a release film suitable for various display component production applications, such as production of various display components (hereinafter abbreviated as organic EL), and the like.

Conventionally, a release film based on a polyester film is used for manufacturing a capacitive touch panel, etc., for various purposes to be bonded via an adhesive layer, LCD polarizing plate, retardation plate manufacturing, PDP component It is used for various optical applications such as for manufacturing, for manufacturing organic EL components, for manufacturing various display components. In recent years, with the thinning of various display components, particularly LCD polarizing plates, there is a problem that the release film and the thin polarizing plate have a high peeling force and cannot be peeled off successfully. If the release film cannot be peeled off successfully from the thin polarizing plate, the yield decreases, which is a problem. In addition, after application of the pressure-sensitive adhesive layer, there is a problem that the inspection property of the polarizing plate for LCD due to oligomer precipitation is lowered and the visibility of the pressure-sensitive adhesive layer is lowered. Another problem is that foreign matter is transferred to the pressure-sensitive adhesive layer due to the inclusion of foreign matter due to charging of the release film.

In recent years, with the advancement of the IT (Information Technology) field, the quality of the release film used when manufacturing display members such as LCDs, PDPs, and organic ELs is improved, and the polyester oligomers from the release film are used for protecting the adhesive layer. Various problems associated with precipitation and peelability between the pressure-sensitive adhesive and the release film are apparent.

Not only for polarizing plates but also for pressure sensitive adhesive sheets that bond surfaces between objects, many problems due to the peeling force of the release film have been reported. Various pressure-sensitive adhesive sheets are known, and a substrate-less double-sided pressure-sensitive adhesive sheet is known as one of the pressure-sensitive adhesive sheets. The substrate-less double-sided PSA sheet consists of a laminate structure in which a light release film with a relatively low peel strength and a heavy release film with a relatively high peel strength are laminated on both sides of the adhesive layer. After the removal, the double-sided pressure-sensitive adhesive sheet becomes only the pressure-sensitive adhesive layer having no supporting substrate.

As a method of using the substrate-less double-sided pressure-sensitive adhesive sheet, first, the light release film is peeled off, and one surface of the exposed pressure-sensitive adhesive layer is adhered to the object surface of the other side to be bonded, and after the adhesion, the heavy release film is further peeled off, A processing step in which the other surface of the exposed pressure-sensitive adhesive layer is bonded to a different object surface, whereby the objects are surface-bonded is exemplified.

In recent years, the baseless double-sided pressure-sensitive adhesive sheet has attracted attention because of its good workability, and its application is expanding. It is also used for members for various optical applications such as mobile phones. In particular, a capacitive touch panel is rapidly expanding its application as an information terminal by a multi-touch operation in which a screen operation is performed with two fingers. Since the capacitive touch panel tends to have a thicker printing step than the resistive film method, a proposal has been made to eliminate the printing step by thickening the adhesive layer. When the pressure-sensitive adhesive layer is made thick, when the release film is peeled off, a part of the pressure-sensitive adhesive layer adheres to the release film, or air bubbles are mixed into the part of the pressure-sensitive adhesive layer transferred to the release film. There was a case. Therefore, when using a substrateless double-sided pressure-sensitive adhesive sheet for optical applications, not only the substrateless double-sided pressure-sensitive adhesive sheet but also the release film to be combined is more stringent than before, and a release film with higher quality is required. The situation is needed.

When using a substrate-less double-sided PSA sheet, when peeling the light release release film from the adhesive layer, the peel strength of the light release release film is high, and it cannot be peeled off well from the adhesive, reducing yield. It has become.

As a solution to this problem, for example, as described in Patent Document 1 and Patent Document 2, a proposal has been made to set the release rate of the release layer below a certain level. However, in recent years, especially when paying attention to the level difference absorbability of the adhesive layer, when the adhesive layer itself uses a more flexible type, even if the release film described above is used, the level is not always satisfactory was there. Further, in the above method, since a silicone resin containing a migration component is added, the migration property deteriorates, and the migration component migrates to the pressure-sensitive adhesive side when bonded to the pressure-sensitive adhesive, and the pressure-sensitive adhesive may be contaminated. There is a problem of contaminating the processing process.

JP 2012-25088 A JP 2012-179888 A

The present invention has been made in view of the above circumstances, and the solution is that the releasability from the pressure-sensitive adhesive is good, the amount of oligomer precipitation is extremely small, the migration is small, for example, the capacitance method For manufacturing various display components such as for manufacturing touch panel, LCD components such as polarizing plates and retardation plates used in liquid crystal displays (LCDs), plasma display panel components, and organic electroluminescence components In addition, another object of the present invention is to provide a release film suitable for various adhesive layer protecting applications.

As a result of intensive studies in view of the above circumstances, the present inventor has found that the above problems can be easily solved by using a polyester film having a specific configuration, and has completed the present invention.

That is, the gist of the present invention is that a polyester film has a silicone-based release layer formed from a coating solution containing a reactive silicone resin having a functional group, an unreactive silicone resin, and a platinum-based catalyst. It exists in the release film characterized by this.

According to the present invention, it is possible to provide a release polyester film having good release properties with an adhesive, very little oligomer precipitation, and low migration, and its industrial value is high.

It is a cross-sectional schematic diagram which shows an example of the base-material-less double-sided adhesive sheet of this invention.

<First Embodiment>
The polyester film referred to in the present invention is a film obtained by stretching a sheet melt-extruded from an extrusion die according to a so-called extrusion method.

The polyester constituting the above film refers to a polymer containing an ester group obtained by polycondensation from dicarboxylic acid and diol or from hydroxycarboxylic acid. Dicarboxylic acids include terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc., and diols include ethylene glycol, 1,4-butane. Examples include diol, diethylene glycol, triethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, and polyethylene glycol. Examples of hydroxycarboxylic acid include p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. be able to. Typical examples of such polymers include polyethylene terephthalate and polyethylene-2,6-naphthalate.

In the film of the present invention, it is preferable to blend particles for the main purpose of imparting easy slipping and preventing scratches in each step. The kind of the particle 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, calcium sulfate, calcium phosphate, and phosphoric acid. Examples of the particles include magnesium, kaolin, aluminum oxide, and titanium oxide. Further, heat-resistant organic particles as described in JP-B-59-5216, JP-A-59-217755 and the like may be used. Examples of other heat-resistant organic particles include thermosetting urea resins, thermosetting phenol resins, thermosetting epoxy resins, benzoguanamine resins, and the like. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.

On the other hand, the shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular about the hardness, specific gravity, a color, etc. These series of particles may be used in combination of two or more as required.

The average particle size of the particles used is usually in the range of 0.01 to 3 μm, preferably 0.1 to 2 μm. When the average particle size is less than 0.01 μm, the slipperiness may not be sufficiently imparted. On the other hand, when the thickness exceeds 3 μm, transparency may be lowered due to the aggregate of the particles when the film is formed, and it is easy to cause breakage, which causes a problem in terms of productivity. There is.

Further, the content of particles in the polyester is usually 0.001 to 5% by weight, preferably 0.005 to 3% by weight. When the particle content is less than 0.001% by weight, the slipperiness of the film may be insufficient. On the other hand, when the content exceeds 5% by weight, the transparency of the film is insufficient. There is a case.

The method for adding particles to the polyester layer is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage for producing the polyester constituting each layer, but it is preferably added after completion of esterification or transesterification.

Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a blending of dried particles and a polyester raw material using a kneading extruder. It is done by methods.

In addition to the above-mentioned particles, conventionally known antioxidants, antistatic agents, thermal stabilizers, lubricants, dyes, pigments, and the like can be added to the polyester film in the present invention as necessary.

The thickness of the polyester 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 15 to 100 μm.

The release film of the present invention has an oligomer amount (OL) of 2.0 mg / m ² or less on the release layer surface after heating at 180 ° C. for 10 minutes. The amount of oligomer after heating is determined by washing the surface of the release film at 180 ° C. for 10 minutes with 4 ml of DMF (dimethylformamide), and determining the amount of oligomer in the DMF by liquid chromatography. The value can be measured as the film surface oligomer amount (mg / m ² ) divided by the film area contacted with DMF.

In order to reduce the OL after heating, there are a method of reducing the amount of oligomer in the polyester by solid phase polymerization of the polyester, a method of providing a coating layer for preventing oligomer precipitation, and the like. In particular, in the present invention, it is effective to provide the coating layer with a function of preventing oligomer precipitation. Various methods can be used to prevent oligomer precipitation. For example, there is a method of containing an organic compound containing aluminum in the coating layer, but the method is not limited thereto.

Next, a production example of the polyester film in the present invention will be specifically described, but it is not limited to the following production examples. That is, a method of using the polyester raw material described above and cooling and solidifying a molten sheet extruded from a die with a cooling roll to obtain an unstretched sheet is preferable. 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 an electrostatic application adhesion method and / or a liquid application adhesion method is preferably employed. Next, the obtained unstretched sheet is stretched in the biaxial direction. In that case, first, the unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is usually 90 to 140 ° C., preferably 95 to 120 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, the film is stretched in the direction perpendicular to the first stretching direction. In this case, the stretching temperature is usually 90 to 170 ° C., and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. is there. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or relaxation within 30% to obtain a biaxially oriented film. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

Also, for the production of the polyester film of the present invention, a simultaneous biaxial stretching method can be employed. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is stretched and oriented in the machine direction and the width direction at a temperature controlled usually at 90 to 140 ° C., preferably 80 to 110 ° C. Is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or under relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

The method for forming the coating layer on the surface of the polyester film is not particularly limited, but a method of coating the coating solution in the process of producing the polyester film is suitably employed. Specifically, a method of applying and drying a coating solution on the surface of an unstretched sheet, a method of applying and drying a coating solution on the surface of a uniaxially stretched film, and a method of applying and drying a coating solution on the surface of a biaxially stretched film Etc. Among these, it is economical to apply a coating solution on the surface of an unstretched film or a uniaxially stretched film, and then simultaneously dry and cure the coating layer in the process of heat-treating the film. Moreover, as a method for forming the coating layer, a method in which some of the above-described coating methods are used in combination can be adopted as necessary. Specifically, a method of applying a first layer on the surface of an unstretched sheet and drying, then stretching in a uniaxial direction, and then applying and drying a second layer can be used. Use the reverse roll coater, gravure coater, rod coater, air doctor coater, etc. shown in “Coating Method” by Yuji Harasaki, Tsuji Shoten, published in 1979, as a method of applying the coating solution to the surface of the polyester film. Can do.

Next, the formation of the coating layer in the present invention will be described. The coating layer constituting the release film of the present invention contains an organosilicon compound in order to improve the oligomer precipitation preventing property and to improve the coating film adhesion between the release layer and the polyester film over time. It is preferable to use an organosilicon compound represented by the following general formula (1).

Si (X) _d (Y) _e (R ¹ ) _f (1)

In the above formula, 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, R1 is a monovalent hydrocarbon group, and has a carbon number 1 to 10, 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 = 4.

The organosilicon compound represented by the general formula (1) has two hydrolyzable groups Y (D unit source) or three (T unit) capable of forming a siloxane bond by hydrolysis / condensation reaction. Source) can be used.

In the general formula (1), the monovalent hydrocarbon group R ¹ has 1 to 10 carbon atoms, and is particularly preferably a methyl group, an ethyl group, or a propyl group.

In the general formula (1), as the hydrolyzable group Y, conventionally known ones can be used, and the following can be exemplified. Methoxy group, ethoxy group, butoxy group, isopropenoxy group, acetoxy group, butanoxime group, amino group and the like. These hydrolyzable groups may be used alone or in combination. 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 suitable hydrolyzability.

In the present invention, specific examples of the organosilicon compound contained in the coating layer include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 5-hexenyltri Methoxysilane, p-styryltrimethoxysilane, trifluoropropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, 2- (3,4-epoxycyclohexyl) Echi It can be exemplified trimethoxysilane.

In the present invention, in order to improve the oligomer deposition preventing property of the release film and to improve the coating film adhesion between the release layer and the polyester film over time, an organic compound containing aluminum is added to the coating layer. It is preferable to contain.

Specific examples of the organic compound having an aluminum element include aluminum tris (acetylacetonate), aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum-di-n-butoxide-monoethylacetoacetate, aluminum di- Examples include iso-propoxide monomethyl acetoacetate, aluminum tris (ethyl acetoacetate) and the like.

The amount of the aluminum compound contained in the coating layer is usually 0.001 to 70% by weight, preferably 5 to 35% by weight, and more preferably 5 to 15% by weight. When the amount of the aluminum compound is 0.001% by weight or less, the curing reaction of the coating layer does not proceed rapidly, and the coating film adhesion on the release surface after forming the release layer on the coating layer is deteriorated. Sometimes. Further, when the amount of the aluminum compound is 70% by weight or more, the aluminum compound remaining in the coating layer does not participate in the curing reaction of the coating layer and prevents the release layer from being cured, and the coating film adheres to the release surface. Sexuality may worsen.

The coating layer can also contain an organic compound having a metal element other than the aluminum element. In particular, an organic tin compound is preferable. Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, dibutyltin dioleate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dibutyltin benzylmalate, dioctyl Examples thereof include tin diacetate and dioctyltin dilaurate.

Further, inorganic particles may be contained for the purpose of improving the adhesion and slipperiness of the coating layer, and specific examples include silica, alumina, kaolin, calcium carbonate, titanium oxide, barium salt and the like.

In addition, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, organic polymer particles, an antioxidant, a UV absorber foaming agent, a dye, and the like may be contained as necessary.

In the range not exceeding the gist of the present invention, only one type of organic solvent may be used for the purpose of improving dispersibility, improving film forming property, etc., and two or more types may be used as appropriate.

The coating amount (after drying) of the coating layer provided on the polyester film constituting the release film in the present invention is usually 0.005 to 1 g / m ² , preferably 0.005 to 0.5 g / m ² . is there. When the coating amount (after drying) is less than 0.005 g / m ² , the uniformity of coating thickness may be insufficient, and the amount of oligomer deposited from the coating layer surface may increase after heat treatment. . On the other hand, when the coating is applied in excess of 1 g / m ² , problems such as a decrease in slipperiness may occur.

In the present invention, the curing conditions for forming the coating layer on the polyester film are not particularly limited. For example, when the coating layer is provided by off-line coating, usually at 60 to 200 ° C. for 3 to 40 seconds, The heat treatment is preferably performed at 80 to 180 ° C. for 3 to 40 seconds as a guide. Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed.

The type of release layer curable silicone resin to be formed on the outermost layer of one of the polyester films obtained in the present invention is any of addition type, condensation type, ultraviolet curable type, electron beam curable type, solventless type, etc. The reaction type can also be used.

Examples of silicone resins having an alkenyl group and an alkyl group as functional groups used in the present invention include the following. First, a curable silicone resin containing an alkenyl group is a diorganopolysiloxane having a trimethylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer (96 mol% dimethylsiloxane unit, 4 mol% methylhexenylsiloxane unit). , Dimethylvinylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer (97 mol% dimethylsiloxane unit, 3 mol% methylhexenylsiloxane unit), dimethylsiloxane / methylhexenyl blocked with dimethylhexenylsiloxy group blocked at both ends of the molecular chain Siloxane copolymers (95 mol% of dimethylsiloxane units and 5 mol% of methylhexenylsiloxane units) can be mentioned. Genpolysiloxanes include trimethylsiloxy group-capped methylhydrogen polysiloxane with both molecular chains, trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer with both molecular chains, and dimethylhydrogensiloxy group-capped methylhydro with molecular chains. Genpolysiloxane, dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer having both molecular chain ends.

As the silicone resin having a hexenyl group and a phenyl group used in the present invention, an organopolysiloxane represented by the following general formula (I) is preferable. Although the chemical structure is shown by the general formula (I), it may be a linear structure or a branched structure. The introduction part of each functional group may be optional.

In the above formula, a and b each represent a positive integer.

As the silicone resin having a vinyl group and a phenyl group used in the present invention, an organopolysiloxane represented by the following general formula (II) is preferable. The chemical structure is shown by the general formula (II), but it may be a linear structure or a branched structure. The introduction part of each functional group may be optional.

In the above formula, c and d each represent a positive integer.

The silicone resin having a hydrosilyl group used in the present invention is preferably an organopolysiloxane represented by the following general formula (III). The chemical structure is shown by the general formula (III), but it may be a linear structure or a branched structure. The introduction part of each functional group may be optional.

In the above formula, e and f each represent a positive integer.

Although the silicone resin having a hexenyl group and the silicone resin having a vinyl polymer group are divided into the formulas (I) and (II), a hexenyl group and a vinyl polymer group may be contained in one organopolysiloxane.

Further, the phenyl group is not necessarily contained in the hexenyl group and vinyl group-containing silicone resin, and one organopolysiloxane may contain the phenyl group.

The ratio of hexenyl group, vinyl group, phenyl group, and hydrosilyl group contained in the silicone resin used in the present invention is as follows. When the hydrosilyl group is 100, the hexenyl group is 35 to 65, the vinyl group is 5 to 35, and the phenyl group is 1 Preferably, it is ˜20. More desirably, the hexenyl group is 45 to 55, the vinyl group is 15 to 25, and the phenyl group is 2 to 10. If the hexenyl group is less than 35, the silicone curing reaction becomes insufficient, the peel force at 30000 mm / min becomes high, and when the release film is peeled off from the adhesive at a high speed, there may be a problem that it does not peel off cleanly. is there. When the hexenyl group exceeds 65, the number of cross-linking points increases in the silicone curing, the peeling force at 300 mm / min becomes high, and there may be a problem that the release film cannot be peeled cleanly from the adhesive. If the vinyl group is less than 15, the silicone curing reaction becomes insufficient, the peel force at 30000 mm / min becomes high, and when the release film is peeled off from the adhesive at a high speed, there may be a problem that the film cannot be peeled cleanly. is there. When the vinyl group exceeds 35, the number of cross-linking points increases in the silicone curing, the peeling force at 300 mm / min becomes high, and there may be a problem that the release film cannot be peeled cleanly from the adhesive. When the phenyl group is less than 1, the silicone film becomes soft, the peeling force at 30000 mm / min becomes high, and when the release film is peeled off from the adhesive at a high speed, there may be a problem that the silicone film does not peel off beautifully. . When the phenyl group exceeds 20, the silicone film becomes too hard, the peeling force at 300 mm / min becomes high, and there may be a problem that the release film does not peel off from the adhesive.

The number of dimethylsilyl groups (a in general formula (I), c in general formula (II), and f in general formula (III)) contained in the silicone resin used in the present invention is preferably 2000 or more and 5000 or less. More preferably, 3000 or more and 4000 or less are preferable. If it is less than 2000, the molecular weight is small, and problems such as transfer of unreacted silicone to the adhesive layer may occur. If it exceeds 5000, the molecular weight is too large, the curing reaction does not proceed smoothly, and the desired release characteristics may not be obtained.

In the present invention, in order to impart light peelability, it is essential to add an unreactive silicone resin having a mass average molecular weight of 50,000 to 100,000.

The unreactive silicone resin is preferably an organopolysiloxane represented by the following general formula (IV).

In the above formula, g represents a positive integer.

The unreactive silicone resin contained in the silicone resin used in the present invention is in the range of 1 to 10% by weight, preferably 1 to 5% by weight. When the content of the unreactive silicone resin is lower than 1%, light peeling does not occur, and when it exceeds 5% by weight, the curability is remarkably lowered and the adhesion is also deteriorated.

In the present invention, silicone oil may be added to reduce the peeling force. The silicone oil is a silicone oil called a straight silicone oil or a modified silicone oil, and examples thereof include the following. Examples of the straight silicone include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and the like. Further, as modified silicone oil, side chain type polyether modified, aralkyl modified, fluoroalkyl modified, long chain alkyl modified, higher fatty acid ester modified, higher fatty acid amide modified, polyether / long chain alkyl modified / aralkyl modified, Examples include phenyl modification, polyether modification at both ends, and polyether / methoxy modification.

The silicone oil component contained in the silicone resin used in the present invention is in the range of 1 to 10% by weight, preferably 1 to 5% by weight. When the content of the silicone oil component is lower than 1%, the speed dependency becomes high. When the content exceeds 5% by weight, the transferability is high, and the adhesive peels off when the adhesive is processed. Etc. will occur.

In the present invention, Nitto Denko Corporation No. The residual adhesion rate with the 31B tape is preferably 80% or more, and more preferably 85% or more. If the residual adhesive rate is lower than 80%, the transferability is high, and the adhesive may be transferred to roll dirt or the pressure-sensitive adhesive surface during processing of the pressure-sensitive adhesive, resulting in a decrease in pressure-sensitive adhesive peeling force.

In the present invention, Nitto Denko Corporation No. The peeling force with a 31B tape at 300 mm / min is preferably 10 to 20 mN / cm. When the peeling force at 300 mm / min exceeds 20 mN / cm, there may be a problem that the release film does not peel off from the adhesive.

In the present invention, Nitto Denko Corporation No. The peeling force at 30000 mm / min with the 31B tape is preferably less than 80 mN / cm. If the peeling force at 30000 mm / min exceeds 80 mN / cm, there may be a problem that when the release film is peeled off from the adhesive at a high speed, it cannot be peeled cleanly.

As the type of the curable silicone resin, any of the curing reaction types such as an addition type, a condensation type, an ultraviolet curable type, an electron beam curable type, and a solventless type can be used. Specific examples include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X, manufactured by Shin-Etsu Chemical Co., Ltd. -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-62-2829, YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, manufactured by Momentive Performance Materials UV9425, XS56-A2775, XS56-A2982, XS56-C6010 XS56-C4880, UV9430, TPR6600, TPR6604, TPR6605, Toray Dow Corning Co., Ltd. DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210, and the like. Further, a release control agent may be used in combination in order to adjust the release property of the release layer.

In the present invention, as a method for providing a release layer on the polyester film, a conventionally known coating method such as reverse roll coating, gravure coating, bar coating, doctor blade coating, or the like can be used. The coating amount of the release layer in the present invention is usually in the range of 0.01 to 1 g / m ² .

In the present invention, a coating layer such as an adhesive layer, an antistatic layer and an oligomer precipitation preventing layer may be provided on the surface where the release layer is not provided, and the polyester film may be subjected to corona treatment, plasma treatment, etc. A surface treatment may be applied.

In the polyester film of the present invention, a platinum-based catalyst that promotes an addition-type reaction is used in order to make the release layer clean and robust. As this component, chloroplatinic acid, alcohol solution of chloroplatinic acid, a complex of chloroplatinic acid and olefin, a platinum compound such as a complex of chloroplatinic acid and alkenylsiloxane, platinum black, platinum-supported silica, platinum-supported activated carbon Is exemplified. The platinum-based catalyst content in the release layer is usually 0.3 to 3.0% by weight, preferably 0.5 to 2.0% by weight. When the platinum-based catalyst content in the release layer is lower than 0.3% by weight, there may be problems such as deterioration of the surface condition due to insufficient peeling force and insufficient curing reaction in the coating layer. On the other hand, when the platinum-based catalyst content in the release layer exceeds 3.0% by weight, the cost is increased, and the process becomes defective due to increased reactivity and generation of gel foreign matter. Sometimes.

Further, since the addition type reaction is very reactive, acetylene alcohol may be added as a reaction inhibitor in some cases. The component is an organic compound having a carbon-carbon triple bond and a hydroxyl group, but preferably 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and phenylbuty It is a compound selected from the group consisting of nor.

In the present invention, the peeling force refers to a double-sided pressure-sensitive adhesive tape (“No. 31B” manufactured by Nitto Denko) attached to the release layer surface and left at room temperature for 1 hour, and then the substrate film and the peeling angle of 180 °. The value measured with a tensile tester when the tape is peeled off at the tensile speed. The method for adjusting the specific peeling force in the present invention can be achieved by selecting the composition in the release layer, but other means can also be adopted, mainly the type of release agent for the silicone release layer. Is preferably changed according to the desired peeling force, and furthermore, since the peeling force largely depends on the application amount of the release agent to be used, a method of adjusting the application amount of the release agent is more preferable.

Regarding the value of the peel force of the polyester film in the present invention, the low speed peel force in the 300 mm / min speed region is usually in the range of 10 to 20 mN / cm. When the peeling force is less than 10 mN / cm, there may be a problem that the peeling force becomes too light and easily peels even in a scene where it is not necessary to peel off. If the peel force exceeds 20 mN / cm, the difference in peel force between the release film with the greater peel force will be small, causing problems in the peel process, and the selection range for the release film with the greater peel force will be narrow. Sometimes it becomes.

Furthermore, the high-speed peeling force in the 60000 mm / min speed region taking into consideration workability is usually 90 mN / cm or less. When the peeling force is greater than 90 mN / cm, the difference in peeling force with the release film having the heavier peeling force becomes small, and peeling may not be performed well in the peeling process, or the adhesive may be peeled off.

After the release film of the present invention is heat-treated (180 ° C., 10 minutes), the amount of polyester oligomer (OL) extracted from the release layer surface with dimethylformamide is usually 2.0 mg / m ² or less, preferably 1 0.0 mg / m ² or less. When the OL exceeds 2.0 mg / m ² , for example, when the liquid crystal component is manufactured, the adhesive layer is used for protecting the adhesive layer, the transparency of the adhesive is lowered, the adhesive strength of the adhesive layer is reduced, or optical evaluation is performed. There may be problems such as causing trouble in the accompanying inspection process.

In the release film of the present invention, the value measured by the FP (Fundamental Parameter Method) method using a fluorescent X-ray measuring device as the amount of aluminum element contained in the coating layer is 0 so that OL satisfies the above range. .2 kcps or more, more preferably 0.5 kcps or more, and particularly preferably 0.8 kcps or more. When the amount of aluminum element is less than 0.2 kcps, the desired oligomer sealing performance may not be obtained.

In the present invention, “oligomer” is defined as a cyclic trimer among low molecular weight polyesters that crystallize and precipitate on the film surface after heat treatment.

<Second Embodiment>
The polyester film constituting the two types of release films in the present invention (hereinafter, the one having a smaller peel force may be referred to as a first release film and the one having a greater release desire may be referred to as a second release film) is a single layer. It may be a configuration or a laminated configuration. For example, it may be a multi-layer of 4 layers or more as long as it does not exceed the gist of the present invention other than a 2-layer or 3-layer configuration, and is particularly limited. It is not a thing.

In the present invention, the polyester used for the polyester film may be a homopolyester or a copolyester. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred.

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.

Typical polyester is exemplified by polyethylene terephthalate (PET).

On the other hand, examples of the dicarboxylic acid component of the copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (eg, P-oxybenzoic acid). One or two or more types can be mentioned, and examples of the glycol component include one or more types such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like. In any case, the polyester referred to in the present invention refers to a polyester that is usually 60 mol% or more, preferably 80 mol% or more of polyethylene terephthalate or the like which is an ethylene terephthalate unit.

In the present invention, it is preferable to mix particles in the polyester layer mainly for the purpose of imparting slipperiness. The kind of the particle 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, calcium sulfate, calcium phosphate, and phosphoric acid. Examples of the particles include magnesium, kaolin, aluminum oxide, and titanium oxide. Further, the heat-resistant organic particles described in JP-B-59-5216, JP-A-59-217755 and the like may be used. Examples of other heat-resistant organic particles include thermosetting urea resins, thermosetting phenol resins, thermosetting epoxy resins, benzoguanamine resins, and the like. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.

The average particle size of the particles used is usually in the range of 0.01 to 3 μm, preferably 0.01 to 1 μm. When the average particle diameter is less than 0.01 μm, the particles are likely to aggregate and dispersibility may be insufficient. On the other hand, when the average particle diameter exceeds 3 μm, the surface roughness of the film becomes too rough and There may be a problem when a release layer is applied in the process.

Furthermore, the particle content in the polyester layer is usually in the range of 0.001 to 5% by weight, preferably 0.005 to 3% by weight. When the particle content is less than 0.001% by weight, the slipperiness of the film may be insufficient. On the other hand, when the content exceeds 5% by weight, the transparency of the film is insufficient. There is.

The method for adding particles to the polyester layer is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage of producing the polyester constituting each layer, but preferably a polycondensation reaction may be carried out after the esterification stage or after the transesterification reaction.

The thickness of the polyester film constituting the first release film and the second release film of the present invention is not particularly limited as long as it can be formed as a film. In the first release film, it is usually in the range of 25 to 75 μm, preferably 38 to 75 μm. On the other hand, in the second release film, it is usually in the range of 25 to 250 μm, preferably 38 to 188 μm, more preferably 50 to 125 μm.

Next, a production example of the polyester film in the present invention will be specifically described, but is not limited to the following production examples.

First, a method in which the polyester raw material described above is used and the molten sheet extruded from the die is cooled and solidified with a cooling roll to obtain an unstretched sheet is preferable. In this case, in order to improve the flatness of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method and / or a liquid application adhesion method are preferably employed. Next, the obtained unstretched sheet is stretched in the biaxial direction. In that case, first, the unstretched sheet is stretched in one direction by a roll or a 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. Next, the stretching temperature orthogonal to the first-stage stretching direction is usually 70 to 170 ° C., and the draw ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Subsequently, heat treatment is performed at a temperature of 180 to 270 ° C. under tension or relaxation within 30% to obtain a biaxially oriented film. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

Also, the simultaneous biaxial stretching method can be adopted for the production of the polyester film in the present invention. The simultaneous biaxial stretching method is a method in which the unstretched sheet is usually stretched and oriented simultaneously in the machine direction and the width direction in a state where the temperature is controlled at 70 to 120 ° C, preferably 80 to 110 ° C. The area magnification is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or under relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

Furthermore, a so-called coating stretching method (in-line coating) for treating the film surface during the above-described polyester film stretching step can be performed. When a coating layer is provided on a polyester film by a coating stretching method, coating can be performed simultaneously with stretching and the thickness of the coating layer can be reduced according to the stretching ratio, producing a film suitable as a polyester film. it can.

Next, the coating layer which comprises the release film in this invention is demonstrated.
The coating layer constituting the release film in the present invention contains a conductive compound (A) in order to improve antistatic properties and oligomer precipitation preventing properties. As the conductive compound (A), a polymer obtained by singly or copolymerizing thiophene or a thiophene derivative is preferable, and in particular, a compound made of thiophene or a thiophene derivative is doped with another anionic compound or A compound which has an anionic group in the compound and is self-doped is preferable because it exhibits excellent conductivity. Examples of the compound (A) include those obtained by polymerizing a compound of the following formula (1) or (2) in the presence of a polyanion.

In the above formula (1), R ₁ and R ₂ each independently represents a hydrogen element, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, for example, Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a cyclohexylene group, and a benzene group.

In the above formula (2), n is an integer of 1 to 4.

In the release film of the present invention, it is preferable to use polythiophene or a polythiophene derivative having the structural formula represented by Chemical Formula 2, for example, in Chemical Formula 2, n = 1 (methylene group), n = 2 (ethylene group) , N = 3 (propylene group) is preferred. Of these, an ethylene group compound with n = 2, that is, poly-3,4-ethylenedioxythiophene is particularly preferable. Examples of polythiophene or polythiophene derivatives include compounds in which a functional group is bonded to

positions

3 and 4 of the thiophene ring. As described above, a compound in which an oxygen atom is bonded to the 3rd and 4th carbon atoms is preferable. For a compound having a structure in which a carbon atom or a hydrogen atom is directly bonded to the carbon atom, it may not be easy to make the coating liquid aqueous.

Examples of the polyanion used at the time of polymerization include poly (meth) acrylic acid, polymaleic acid, polystyrene sulfonic acid and the like. These acids may be partially or completely neutralized.

As a method for producing such a polymer, for example, a method disclosed in JP-A-7-90060 can be employed.

In the present invention, a particularly preferred embodiment includes a compound of the above formula (2) in which n = 2 and polystyrene sulfonic acid is used as a polyanion.

The coating layer constituting the release film in the present invention is required to contain the above conductive compound and binder polymer.

The binder polymer (B) constituting the coating layer in the present invention is a gel permeation chromatography (GPC) measurement according to a polymer compound safety evaluation flow scheme (sponsored by the Chemical Substance Council in November 1985). It is defined as a polymer compound having a number average molecular weight (Mn) of 1000 or more and having a film-forming property.

The binder polymer (B) constituting the coating layer in the present invention may be either a thermosetting resin or a thermoplastic resin as long as it is compatible with, or mixed with, thiophene or a thiophene derivative. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyimides such as polyimide and polyamideimide; polyamides such as polyamide 6,

polyamide

6,6, polyamide 12, and polyamide 11; polyvinylidene fluoride, polyvinyl fluoride, poly Fluorine resin such as tetrafluoroethylene, ethylenetetrafluoroethylene copolymer, polychlorotrifluoroethylene; vinyl resin such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride; epoxy resin; oxetane resin; xylene resin; Aramid resin; Polyimide silicone; Polyurethane; Polyurea; Melamine resin; Phenol resin; Polyether; It includes copolymers of.

The blending ratio of the conductive compound (A) in the coating layer is 10 to 90% by weight, preferably 20 to 80% by weight. If it is less than 10% by weight, the antistatic property and the oligomer precipitation preventing property may be insufficient. On the other hand, if it exceeds 80% by weight, the antistatic property is already in a saturated state, and even if the amount is increased further, it may be difficult to obtain a remarkable effect.

These binder polymers (B) may be dissolved in an organic solvent, or may be formed into an aqueous solution by adding a functional group such as a sulfo group or a carboxy group. Moreover, you may use together hardening | curing agents, such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, etc. to a binder polymer (B) as needed.

Among the binder polymers (B), at least one selected from polyester resins, acrylic resins, and polyurethane resins is preferable because mixing at the time of preparing the coating liquid is easy. A polyurethane resin is particularly preferable.

The polyester resin used in the present invention is defined as a linear polyester having a dicarboxylic acid component and a glycol component as constituent components. Dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, phenylindanedicarboxylic acid, A dimer acid etc. can be illustrated. Two or more of these components can be used. In addition to these components, a small proportion of unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid and the like, and hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (β-hydroxyethoxy) benzoic acid, etc. Can be used. The proportion of the unsaturated polybasic acid component or the hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

Examples of the glycol component include ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylolpropionic acid. Glycerin, trimethylolpropane, poly (ethyleneoxy) glycol, poly (tetramethyleneoxy) glycol, an alkylene oxide adduct of bisphenol A, an alkylene oxide adduct of hydrogenated bisphenol A, and the like. Two or more of these can be used.

Among such polyol components, ethylene glycol and bisphenol A ethylene oxide adducts and propylene oxide adducts and 1,4-butanediol are preferred, and ethylene glycol and bisphenol A ethylene oxide adducts and propylene oxide adducts are more preferred. The polyester resin can be copolymerized with a small amount of a compound having a sulfonate group or a compound having a carboxylic acid group in order to facilitate aqueous liquefaction, which is preferable. Examples of the compound having a sulfonate group include 5-sodium sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-sodium sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid, 2-sodium sulfoisophthalic acid, 5-potassium Preferable examples include sulfonic acid alkali metal salts such as sulfoisophthalic acid, 4-potassium sulfoisophthalic acid, 2-potassium sulfoisophthalic acid, and sodium sulfosuccinic acid, and sulfonic acid amine salt compounds.

Examples of the compound having a carboxylate group include trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid, dimethylolpropionic acid, and monoalkali metal salts thereof. Etc. The free carboxyl group is converted into a carboxylate group by allowing an alkali metal compound or an amine compound to act after copolymerization. A polyester obtained by selecting one or more compounds from these compounds and synthesizing them by a conventional polycondensation reaction can be used.
Regarding the polyester resin, the glass transition temperature (hereinafter sometimes abbreviated as Tg) is usually 40 ° C. or higher, preferably 60 ° C. or higher. When Tg is less than 40 ° C., for the purpose of improving adhesiveness, when the coating thickness of the coating layer is increased, problems such as easy blocking may occur.

The acrylic resin is a polymer composed of a polymerizable monomer having a carbon-carbon double bond, as typified by an acrylic or methacrylic monomer. These may be either a homopolymer or a copolymer. Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Furthermore, a polymer (in some cases, a mixture of polymers) obtained by polymerizing a polymerizable monomer having a carbon-carbon double bond 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 having a carbon-carbon double bond in a polyurethane solution or polyurethane dispersion is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer having a carbon-carbon double bond in another polymer solution or dispersion is also included.

The polymerizable monomer having a carbon-carbon double bond is not particularly limited, but representative compounds such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Various carboxyl group-containing monomers and their salts; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutylhydroxyl fumarate, monobutylhydroxy Various hydroxyl-containing monomers such as itaconate; various (meth) acrylic such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate Acid esters; (meth) a Riruamido, various nitrogen-containing vinyl monomers such as diacetone acrylamide, N- methylol acrylamide or (meth) acrylonitrile. Further, in combination with these, polymerizable monomers as shown below can be copolymerized. That is, various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene and vinyltoluene, various vinyl esters such as vinyl acetate and vinyl propionate; γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, Various silicon-containing polymerizable monomers such as methacryloyl silicon macromer; phosphorus-containing vinyl monomers; vinyl chloride, biliden chloride, vinyl fluoride, vinylidene fluoride, trifluorochloroethylene, tetrafluoroethylene, chlorotrifluoroethylene And various vinyl halides such as hexafluoropropylene; and various conjugated dienes such as butadiene.

In the acrylic resin, the glass transition temperature (hereinafter sometimes abbreviated as Tg) is usually 40 ° C. or higher, preferably 60 ° C. or higher. When Tg is less than 40 ° C., for the purpose of improving adhesiveness, when the coating thickness of the coating layer is increased, problems such as easy blocking may occur.

The polyurethane resin in the present invention refers to a polymer compound having a urethane bond in the molecule. Among these, when considering suitability for in-line coating, a water-dispersible or water-soluble urethane resin is preferable. In order to impart water dispersibility or water solubility, it is possible to introduce a hydrophilic group such as a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonyl group, a phosphoric acid group, or an ether group into the urethane resin. Among the hydrophilic groups, a carboxylic acid group or a sulfonic acid group is preferably used from the viewpoint of improving physical properties of the coating film and adhesion.

As a specific production example of the urethane resin, for example, a method utilizing a reaction between a hydroxyl group and an isocyanate can be mentioned. As the hydroxyl group used as the raw material, polyol is preferably used, and examples thereof include polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination.

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

Polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides. And polyhydric alcohol (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- , 3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexane Diol, 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, alkyl dialkanolamine, lactone diol, etc.).

Examples of polycarbonate polyols include polycarbonate diols obtained by dealcoholization reaction from polyhydric alcohols and dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and the like, such as poly (1,6-hexylene) carbonate, poly ( And 3-methyl-1,5-pentylene) carbonate.

Examples of the polyisocyanate compound used for obtaining the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate, α, α, α ′, α ′. -Aliphatic diisocyanates having aromatic rings such as tetramethylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl Methanzi Isocyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination.

When synthesizing a urethane resin, a conventionally known chain extender may be used, and the chain extender is not particularly limited as long as it has two or more active groups that react with an isocyanate group. A chain extender having two hydroxyl groups or amino groups is generally 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. It can be mentioned that glycols such as glycol are exemplified.
Examples of the chain extender having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, 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 decane diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidine cyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1 , 3-bisaminomethylcyclohexane, etc. And alicyclic diamines.

The blending ratio of the binder polymer (B) in the coating layer is in the range of 10 to 90%, more preferably in the range of 20 to 80%. When the said range is less than 10%, the adhesiveness with respect to a mold release layer may fall. On the other hand, when it exceeds 80%, the adhesion performance becomes saturated, and even if the amount is increased further, a remarkable effect may not be obtained.

In the present invention, the coating layer constituting the release film preferably contains a polyurethane resin for the purpose of improving the adhesion to the release layer.

The coating liquid for providing the coating layer in the present invention is selected from the group of glycerin (C1), polyglycerin (C2), glycerin or an alkylene oxide adduct (C3) to polyglycerin as the component (C). It is preferred to contain more than one compound or derivative thereof. Those having an average number of glycerin units in the molecule in the range of 2 to 20 are preferred.
Incidentally, when glycerin is used, the transparency of the coating layer may be slightly inferior.

Further, the alkylene oxide adduct to glycerin or polyglycerin has a structure in which alkylene oxide or a derivative thereof is added and polymerized to the hydroxyl group of glycerin or polyglycerin.

Here, the structure of the alkylene oxide to be added or its derivative may be different for each hydroxyl group of the glycerin or polyglycerin skeleton. Moreover, it is sufficient that it is added to at least one hydroxyl group in the molecule, and it is not necessary that alkylene oxide or a derivative thereof is added to all hydroxyl groups.

A preferable alkylene oxide or derivative thereof is a structure containing an ethylene oxide or propylene oxide skeleton. If the alkyl chain in the alkylene oxide structure becomes too long, the hydrophobicity becomes strong, the uniform dispersibility in the coating solution deteriorates, and the antistatic property and transparency of the coating film tend to deteriorate. Particularly preferred is ethylene oxide.

In such an alkylene oxide adduct to glycerin or polyglycerin, the copolymerization ratio of alkylene oxide or its derivative to glycerin or polyglycerin skeleton is not particularly limited, but when the glycerin or polyglycerin moiety is 1 in terms of molecular weight ratio The alkylene oxide moiety is preferably 20 or less, more preferably 10 or less. When the ratio of the alkylene oxide or its derivative to the glycerin or polyglycerin skeleton is larger than this range, the characteristics of the ordinary polyalkylene oxide are close to those obtained, and the effects of the present invention may not be sufficiently obtained. is there.

With regard to the compound (C) in the present invention, particularly preferred embodiments include polyglycerol (C2) and alkylene oxide adduct (C3) to glycerol or polyglycerol. As the polyglycerin (C2), those having n of 2 to 20 in the compound of the above formula (3) are particularly preferred. Further, as the alkylene oxide adduct (C3) to glycerin or polyglycerin, a compound having a structure in which ethylene oxide or polyethylene oxide is added to n = 2 in the compound of the above formula (3) is preferable. The number is particularly preferably in the range of 300 to 2000 in terms of the weight average molecular weight as the final compound (C3).

The blending ratio of component (C) in the coating layer is in the range of 10 to 90%, more preferably in the range of 20 to 80%. When the said range is less than 10%, applicability | paintability may fall. On the other hand, if it exceeds 90%, the durability of the coating layer may be insufficient.

In this invention, regarding the coating layer which comprises a release film, the weight of the coating agent component (A) which occupies in a coating layer is 0.5 mg / m < ² > or more normally, Preferably it is 1 mg / m < ² > or more. When the amount of the coating agent component (A) is less than 0.5 mg / m ² , the antistatic property tends to be insufficient.

In the present invention, the ratio of the coating agent component (A) in the coating layer constituting the release film is not limited, but the upper limit is preferably 90%, more preferably 80%, and most preferably 60%. It is. When the ratio of the coating agent component (A) exceeds 90% by weight, the transparency of the coating film may be insufficient, or the antistatic performance may be insufficient.
On the other hand, the lower limit is preferably 1%, more preferably 2%. When the weight ratio of the coating agent component (A) is less than 1%, the antistatic performance may be insufficient.

In the coating layer constituting the release film in the present invention, the ratio of the coating agent component (A) and the coating agent component (B) is preferably in the range of 90/10 to 1/99 by weight. More preferably, it is in the range of 70/30 to 1/99, most preferably 50/50 to 2/98. Outside this range, the antistatic performance or the appearance of the coating film tends to deteriorate.
In the coating solution used in the present invention, a surfactant can be contained in order to improve the coating property to the polyester film. As this surfactant, it is more preferable to use a surfactant containing (poly) alkylene oxide, (poly) glycerin, or a derivative thereof in the structure, since it does not inhibit the antistatic property of the resulting coating layer.

The coating liquid used in the present invention includes an antifoaming agent, a coating property improver, a thickener, an organic lubricant, a release agent, organic particles, inorganic particles, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, You may contain additives, such as a pigment. These additives may be used alone or in combination of two or more as necessary. Moreover, as these additives, it is more preferable to use those containing (poly) alkylene oxide, (poly) glycerin, or derivatives thereof in the structure without inhibiting the antistatic property of the resulting coating layer.

The coating liquid in the present invention is preferably an aqueous solution or a water dispersion from the viewpoint of handling, working environment, and stability of the coating liquid composition, but water is the main medium and exceeds the gist of the present invention. If it is not within the range, an organic solvent may be contained.

The coating layer in the present invention is provided by applying a coating solution containing a specific compound to a film, and in particular in the present invention, it is preferably provided by in-line coating in which coating is performed during film formation.

Next, the formation of the release layer in the present invention will be described.

The release layer constituting the first release film and the second release film in the present invention refers to a layer having releasability. Specifically, the peeling force between the adhesive layer and the release layer is constant. By setting the range, the present invention can be completed.

The low-speed peeling force at 0.3 m / min of the first release film 31 needs to be 10 to 20 mN / cm. When the peeling force of the first release film is less than 10 mN / cm, the release film is easily peeled in a scene that does not need to be peeled. On the other hand, when the peeling force of a 1st release film exceeds 20 mN / cm, it becomes difficult to peel smoothly in the process of peeling a 1st release film.

Furthermore, in the present invention, it is necessary to suppress the high-speed peeling force of 60 m / min to 90 mN / cm or less. Preferably it is 85 mN / cm or less. When the high-speed peeling force exceeds 90 mN / cm, it becomes difficult to peel smoothly.

For example, when the first release film is peeled from the base material-less double-sided pressure-sensitive adhesive sheet in a state immediately before being bonded to the electronic component, the inventor cut in advance into a small piece sheet shape close to the size of the electronic component. After that, it is common for an operator to peel off by hand. In the peeling operation step, the cut pieces are used to give a chance to peel off the first release film and then peeled 180 degrees in the diagonal direction of the pieces.

In this case, unlike the case where the release film is peeled 180 degrees from the normal adhesive tape, in the peeling direction, the release film is peeled in the diagonal direction, so that the peeling area gradually increases as the peeling progresses. There is a tendency. The present inventor paid attention to this peeling method and regarded the phenomenon in which the peeling area increases at a constant peeling speed as a peeling method with a faster peeling propagation speed as a phenomenon of peeling a larger area within the same time. . As in the present invention, when using a flexible adhesive layer in consideration of step absorbability, it has been found that it is effective to suppress the high-speed peeling force at a constant peeling force level to 60 m / min. The invention has been completed.

On the other hand, the peeling force at 0.3 m / min of the second release film is preferably 20 to 100 mN / cm, more preferably 40 to 80 mN / cm. When the peeling force of the second release film is less than 20 mN / cm, when the first release film is peeled from the substrate-less double-sided pressure-sensitive adhesive sheet, there may be a problem that a part of the second release film is peeled off. is there. Moreover, when the peeling force of a 2nd mold release film exceeds 100 mN / cm, malfunctions, such as a component derived from an adhesive layer remaining in a 2nd mold release film, may arise.

The substrate-less double-sided pressure-sensitive adhesive sheet of the present invention provides a difference in peel force between the first release film and the second release film in addition to the above-described peel force adjustment.

The peel force of the second release film is usually 2.0 times or more, preferably 3.0 times or more of the peel force of the first release film. When the peel force of the second release film is less than 2.0 times the peel force of the first release film, the second release film floats from the pressure-sensitive adhesive layer when the first release film on the light release side is peeled off. The phenomenon may occur, or the adhesive layer component may remain on the second release film, or a defect such as zipping may occur.

The release layer constituting the release film in the present invention preferably contains a curable silicone resin in order to improve the release property. It may be a type mainly composed of a curable silicone resin, or a modified silicone type by graft polymerization with an organic resin such as a urethane resin, an epoxy resin or an alkyd resin may be used as long as the gist of the present invention is not impaired. Also good.

In the present invention, the release film having a smaller peel force comprises a reactive silicone resin having an alkenyl group and an alkyl group as functional groups on a polyester film, an unreactive silicone resin having a mass average molecular weight of 400,000 or more, a platinum-based catalyst, It is necessary to have a release layer containing.

Examples of the silicone resin having an alkenyl group and an alkyl group as functional groups used in the present invention include the following. First, a curable silicone resin containing an alkenyl group is a diorganopolysiloxane having a trimethylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer (96 mol% dimethylsiloxane unit, 4 mol% methylhexenylsiloxane unit). ), Dimethylvinylsiloxy group-blocked dimethylsiloxane / methylhexenylsiloxane copolymer (97 mol% dimethylsiloxane unit, 3 mol% methylhexenylsiloxane unit), dimethylsiloxane / methyl-blocked dimethylhexenylsiloxy group blocked at both ends of the molecular chain Hexenylsiloxane copolymer (95 mol% of dimethylsiloxane units, 5 mol% of methylhexenylsiloxane units). Next, the curable silicone resin containing an alkyl group is a trimethylsiloxy group-blocked methylhydrogenpolysiloxane having both molecular chains and trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane as both organohydrogenpolysiloxanes. Examples thereof include a polymer, a dimethylhydrogensiloxy group-capped methylhydrogen polysiloxane having both molecular chains, and a dimethylsiloxane / methylhydrogensiloxane copolymer having both molecular chains having both ends dimethylhydrogensiloxy group-capped.

In the present invention, it is essential to add an unreactive silicone resin having a mass average molecular weight of 400,000 or more in order to impart light peelability without deteriorating migration.
The unreactive silicone resin is preferably an organopolysiloxane represented by the following general formula (I).

R ³ SiO (R ² SiO) _m SiR ³ (I)
(In the above formula, R represents the same or different monovalent hydrocarbon group having no aliphatic unsaturated bond, and m represents a positive integer.)

The unreactive silicone resin contained in the silicone resin used in the present invention is in the range of 1 to 10% by weight, preferably 1 to 5% by weight. When the content of the unreactive silicone resin is lower than 1%, the speed dependency is increased, and when it exceeds 5% by weight, the curability is remarkably lowered and the adhesion may be deteriorated.

In the present invention, silicone oil may be added to reduce the peeling force in the high speed range. The silicone oil is a silicone oil called a straight silicone oil or a modified silicone oil, and examples thereof include the following. Examples of the straight silicone include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and the like. Further, as modified silicone oil, side chain type polyether modified, aralkyl modified, fluoroalkyl modified, long chain alkyl modified, higher fatty acid ester modified, higher fatty acid amide modified, polyether / long chain alkyl modified / aralkyl modified, Examples include phenyl modification, polyether modification at both ends, and polyether / methoxy modification.

The silicone oil component contained in the silicone resin used in the present invention is usually in the range of 1 to 10% by weight, preferably 1 to 5% by weight. When the content of the silicone oil component is lower than 1%, the speed dependency becomes high. When the content exceeds 5% by weight, the transferability is high, and the adhesive peels off when the adhesive is processed. May occur.

In the present invention, Nitto Denko Corporation No. The residual adhesion rate by 31B tape is preferably 85% or more, and more preferably 90% or more. If the residual adhesive rate is lower than 80%, the transferability is high, and the adhesive may be transferred to roll dirt or the pressure-sensitive adhesive surface during processing of the pressure-sensitive adhesive, resulting in a decrease in pressure-sensitive adhesive peeling force.

As the type of the curable silicone resin, any of the curing reaction types such as an addition type, a condensation type, an ultraviolet curable type, an electron beam curable type, and a solventless type can be used. Specific examples include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X, manufactured by Shin-Etsu Chemical Co., Ltd. -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, YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, manufactured by Momentive Performance Materials XS56-A2982, XS56-C6010, XS56-C488 , UV9430, TPR6600, TPR6604, TPR6605, manufactured by Toray Dow Corning Co., Ltd. 202, DKQ3-203, DKQ3-204, DKQ3-205, DKQ3-210, and the like. Further, a release control agent may be used in combination in order to adjust the release property of the release layer.

In the present invention, the curing conditions for forming the release layer on the polyester film are not particularly limited. When the release layer is provided by off-line coating, it is usually 120 to 200 ° C. for 3 to 40 seconds, preferably Is preferably heat-treated at 100 to 180 ° C. for 3 to 40 seconds as a guide. Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed. In addition, a conventionally well-known apparatus and an energy source can be used as an energy source for hardening by active energy ray irradiation.

The coating amount of the release layer (after drying) is usually 0.005 to 1 g / m ² , preferably 0.005 to 0.5 g / m ² , more preferably 0.01 to 0 from the viewpoint of coating properties. .2 g / m ² range. When the coating amount (after drying) is less than 0.005 g / m ² , the coating property may be less stable and it may be difficult to obtain a uniform coating film. On the other hand, when the coating is thicker than 1 g / m ² , the coating layer adhesion and curability of the release layer itself may be lowered.

As a configuration of the base material-less double-sided pressure-sensitive adhesive sheet in the present invention, it is necessary to bond release films on both sides of the pressure-sensitive adhesive layer. Regarding the thickness ratio of each release film, the handleability is taken into consideration, and the thickness of the second release film is preferably 2 times or more, preferably 3 times or more the thickness of the first release film. For example, by reducing the film thickness of the first release film, there is an advantage that it is possible to prevent floating that occurs at the adhesive interface with the second release film when the first release film is peeled off. In addition, when the adhesive layer is applied on the release surface of the second release film, in order to eliminate the influence of foreign matter and unevenness in the process, the influence of unevenness and foreign matter is more It is preferable to further increase the film thickness of the second release film that is easily received. When the thickness of the second release film is less than twice the thickness of the first release film, there is no difference in stiffness of the film substrate, and the first release film is peeled from the substrate-less double-sided pressure-sensitive adhesive sheet. At this time, there may be a problem that a part of the second release film is peeled off.

Regarding the first release film and the second release film in the present invention, an adhesive layer, an antistatic layer, an oligomer precipitation-preventing layer, etc., as long as the gist of the present invention is not impaired on the film surface on which no release layer is provided. A coating layer may be provided.

In the polyester film of the present invention, a platinum-based catalyst that promotes an addition-type reaction is used in order to make the release layer of the release film having a trans-peeling force clean and strong. As this component, chloroplatinic acid, alcohol solution of chloroplatinic acid, a complex of chloroplatinic acid and olefin, a platinum compound such as a complex of chloroplatinic acid and alkenylsiloxane, platinum black, platinum-supported silica, platinum-supported activated carbon Is exemplified. The platinum-based catalyst content in the release layer is usually 0.3 to 3.0% by weight, preferably 0.5 to 2.0% by weight. When the platinum-based catalyst content in the release layer is lower than 0.3% by weight, there may be problems such as deterioration of the surface condition due to insufficient peeling force and insufficient curing reaction in the coating layer. On the other hand, when the platinum-based catalyst content in the release layer exceeds 3.0% by weight, the cost is increased, and the process becomes defective due to increased reactivity and generation of gel foreign matter. Sometimes.

Further, the polyester film constituting the first release film and the second release film may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

In this invention, when manufacturing a release film, after apply | coating a coating layer on a polyester film, after winding up a film, a release layer may be provided on a coating layer further, and it apply | coats on a polyester film. After applying and drying the layer, a release layer may be continuously provided on the coating layer, and any method may be used in the present invention.

Next, the pressure-sensitive adhesive layer constituting the substrate-less double-sided pressure-sensitive adhesive sheet according to the present invention will be described below. The adhesive layer in the present invention means a layer composed of a material having adhesiveness, and conventionally known materials can be used as long as the gist of the present invention is not impaired. As one specific example, the case where an acrylic adhesive is used will be described below.

In the present invention, the acrylic pressure-sensitive adhesive means a pressure-sensitive adhesive layer containing, as a base polymer, an acrylic polymer formed using an acrylic monomer as an essential monomer component. The acrylic polymer has (meth) acrylic acid alkyl ester and / or (meth) acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as an essential monomer component (more preferably as a main monomer component). ) It is preferably an acrylic polymer to be formed. Furthermore, the acrylic polymer is preferably an acrylic polymer formed using (meth) acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as essential monomer components.

The pressure-sensitive adhesive layer of the present invention is preferably an acrylic pressure-sensitive adhesive layer formed using (meth) acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester having a linear or branched alkyl group as essential monomer components.

In addition, the monomer component forming the acrylic polymer that is the base polymer in the adhesive layer of the present invention is further copolymerized with a polar group-containing monomer, a polyfunctional monomer, and other copolymerizable monomers. It may be contained as a monomer component. In addition, said "(meth) acryl" represents "acryl" and / or "methacryl", and others are the same. Further, although not particularly limited, the content of the acrylic polymer as the base polymer in the pressure-sensitive adhesive layer of the present invention is preferably 60% by weight or more, more preferably based on the total weight (100% by weight) of the pressure-sensitive adhesive layer. 80% by weight or more.

As a monomer component for forming the acrylic polymer, a (meth) acrylic acid alkyl ester having a linear or branched alkyl group (hereinafter sometimes simply referred to as “(meth) acrylic acid alkyl ester”) is used. It can be used suitably. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate , Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic acid Isodecyl, undecyl (meth) acrylate, dodecyl (meth) acrylate, (Meth) acrylic acid tridecyl, (meth) acrylic acid tetradecyl, (meth) acrylic acid pentadecyl, (meth) acrylic acid hexadecyl, (meth) acrylic acid heptadecyl, (meth) acrylic acid octadecyl, (meth) acrylic acid nonadecyl, (meta Examples thereof include (meth) acrylic acid alkyl esters having 1 to 20 carbon atoms, such as eicosyl acrylate. Moreover, the (meth) acrylic acid alkyl ester may be used alone or in combination of two or more. Among them, (meth) acrylic acid alkyl esters having 2 to 14 carbon atoms in the alkyl group are preferable, and (meth) acrylic acid alkyl esters having 2 to 10 carbon atoms in the alkyl group are more preferable.

Examples of the polar group-containing monomer include, for example, (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and other carboxyl group-containing monomers or anhydrides thereof (such as maleic anhydride) Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, Hydroxyl group (hydroxyl group) -containing monomers such as vinyl alcohol and allyl alcohol; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N -Butoxymethyl (meth) acrylamide, N-hydro Amide group-containing monomers such as ethyl acrylamide; Amino group-containing monomers such as aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate; ) Glycidyl group-containing monomers such as glycidyl acrylate and methyl glycidyl (meth) acrylate; Cyan group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, other than (meth) acryloylmorpholine , N-vinyl pyridine, N-vinyl piperidone, N-vinyl pyrimidine, N-vinyl piperazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole and other heterocyclic ring-containing vinyl monomers; sodium vinyl sulfonate, etc. Sulfonic acid group-containing monomer of 2-hydroxyethyl Chestnut phosphoric acid group-containing monomers such as acryloyl phosphate; cyclohexyl maleimide, imide group-containing monomers such as isopropyl maleimide; 2-methacryloyloxy such acryloyl isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate. The polar group-containing monomers can be used alone or in combination of two or more.

Examples of the polyfunctional monomer include hexanediol di (meth) acrylate, butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methanetri (meth) Examples include acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, and urethane acrylate. The said polyfunctional monomer can also be used individually or in combination of 2 or more types.

The content of the polyfunctional monomer is preferably 0.5% by weight or less with respect to 100% by weight of the monomer component forming the acrylic polymer. When the content exceeds 0.5% by weight, for example, the cohesive force of the pressure-sensitive adhesive layer becomes too high, and the stress relaxation property may be lowered.

Examples of copolymerizable monomers (other copolymerizable monomers) other than the polar group-containing monomer and multifunctional monomer include cyclopentyl (meth) acrylate and cyclohexyl (meth) acrylate. (Meth) acrylic acid ester having an alicyclic hydrocarbon group such as isobornyl (meth) acrylate, and (meth) acrylic acid ester having an aromatic hydrocarbon group such as phenyl (meth) acrylate. (Meth) acrylic acid esters other than alkyl acrylates, alkoxyalkyl (meth) acrylates, polar group-containing monomers and polyfunctional monomers; vinyl esters such as vinyl acetate and vinyl propionate; styrene, Aromatic vinyl compounds such as vinyl toluene; ethylene, butadiene, isoprene, isobutylene, etc. Olefins or dienes; vinyl ethers such as vinyl alkyl ethers; and vinyl chloride.

The acrylic polymer can be prepared by polymerizing the above monomer components by a conventionally known or conventional polymerization method. Examples of the polymerization method of the acrylic polymer include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by active energy ray irradiation (active energy ray polymerization method). Among these, the solution polymerization method and the active energy ray polymerization method are preferable in terms of transparency, water resistance, production cost and the like.

Examples of the active energy rays irradiated in the above active energy ray polymerization (photopolymerization) include ionizing radiation such as α rays, β rays, γ rays, neutron rays, electron rays, and ultraviolet rays, among others. Ultraviolet rays are suitable for the use of the present invention. Further, the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as they do not impair the gist of the present invention.

In the solution polymerization, various common solvents can be used. Specific examples include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; and alicyclic rings such as cyclohexane and methylcyclohexane. Organic hydrocarbons such as formula hydrocarbons; ketones such as methyl ethyl ketone and methyl isobutyl ketone are exemplified. A solvent can be used individually or in combination of 2 or more types.

In preparing the acrylic polymer, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) can be used depending on the type of polymerization reaction. A polymerization initiator can also be used individually or in combination of 2 or more types.

The photopolymerization initiator is not particularly limited, but is a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-ketol photopolymerization initiator, an aromatic sulfonyl chloride photopolymerization initiator, Photoactive oxime photopolymerization initiators, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, and the like can be used. The amount of the photopolymerization initiator used is not particularly limited as long as it does not impair the gist of the present invention. For example, the amount of the photopolymerization initiator is 0.1% relative to 100 parts by weight of the total amount of monomer components forming the acrylic polymer. A range of 01 to 0.2 parts by weight is preferred.

Specific examples of the benzoin ether photopolymerization initiator include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one And anisole methyl ether. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl). Examples include dichloroacetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and the like. . Specific examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime. Examples of the benzoin photopolymerization initiator include benzoin. Examples of the benzyl photopolymerization initiator include benzyl.

Specific examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Specific examples of the ketal photopolymerization initiator include benzyldimethyl ketal. Specific examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, and the like.

Specific examples of the thermal polymerization initiator include azo polymerization initiators [for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis. (2-methylpropionic acid) dimethyl, 4,4′-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [ 2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-di) Methyleneisobutylamidine) dihydrochloride], peroxide polymerization initiators (eg, dibenzoyl peroxide, tert-butylpermaleate, etc.), red Box-type polymerization initiators and the like. The amount of the thermal polymerization initiator used is not particularly limited as long as it does not impair the gist of the present invention.

In the acrylic pressure-sensitive adhesive layer used as one embodiment of the pressure-sensitive adhesive layer in the present invention, a crosslinking agent, a crosslinking accelerator, a tackifier (for example, rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin) Etc.), anti-aging agents, fillers, colorants (pigments, dyes, etc.), UV absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents and other known additives Can be used as long as the characteristics of the present invention are not impaired. Moreover, when forming an adhesion layer, various general solvents can also be used. The type of the solvent is not particularly limited, and those exemplified as the solvent used in the above solution polymerization can be used.

The cross-linking agent can control the gel fraction of the adhesive layer by crosslinking the base polymer of the adhesive layer. As crosslinking agents, isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents Agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, and the like, and isocyanate crosslinking agents and epoxy crosslinking agents can be preferably used. A crosslinking agent can also be used individually or in combination of 2 or more types.

In the base material-less double-sided pressure-sensitive adhesive sheet of the present invention, when an acrylic pressure-sensitive adhesive composition is used at the time of forming the pressure-sensitive adhesive layer, for example, an optical member (for example, a surface protective layer, a touch panel, and an image display unit) By replacing the air gap between the display surfaces with a transparent adhesive sheet whose refractive index is close to that of the optical member compared to air, the light transmission is improved and the brightness and contrast of the image display device are reduced. In consideration of restraining, it is preferable to design the adhesive layer itself flexibly.

The thickness of the pressure-sensitive adhesive layer (after drying) constituting the substrate-less double-sided pressure-sensitive adhesive sheet in the present invention is usually in the range of 25 to 200 μm, preferably 50 to 100 μm. When the thickness of the pressure-sensitive adhesive layer is less than 25 μm, for example, the gap generated between the optical members becomes too large, and it may be difficult to fill the corners with the pressure-sensitive adhesive layer. On the other hand, when the thickness of the adhesive layer exceeds 200 μm, the adhesive layer thickness becomes too thicker than the gap generated between the optical members, and the excess adhesive layer component protrudes from between the optical members. There is.

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 unless it exceeds the gist. The measurement method and evaluation method used in the present invention are as follows.

(1) Measurement of average particle diameter (d50: μm):
The value of 50% of integration (weight basis) in the equivalent spherical distribution measured using a centrifugal sedimentation type particle size distribution measuring apparatus (SA-CP3 type manufactured by Shimadzu Corporation) was defined as the average particle diameter.

(2) Release force of release film (I):
After attaching one side of a double-sided adhesive tape (“No. 31B” manufactured by Nitto Denko) to the surface of the release layer of the sample film, the sample film was cut to a size of 50 mm × 300 mm and then peeled after being left at room temperature for 1 hour. taking measurement. For the peeling force, a tensile tester (“Intesco model 2001 type” manufactured by Intesco Co., Ltd.) was used, and 180 ° peeling was performed under conditions of a tensile speed of 300 mm / min and 30000 mm / min.

(3) Transferability evaluation of release film (residual adhesion rate):
Cut the sample film into A4 size, and attach the adhesive tape (Nitto Denko “No. 31B” base material thickness 25 μm) to the measurement surface of the film using a rubber roller. The adhesive tape is peeled off and bonded to the stainless steel plate whose surface has been cleaned using a rubber roller. Adhesive tape is fixed to the upper chuck, and a stainless steel plate is fixed to the lower chuck. The adhesive is peeled off at 180 ° at a speed of 300 mm / mIn and the adhesive force (1) is measured.
Using an adhesive tape (Nitto Denko Corporation “No. 31B”) that is not bonded to the sample, the adhesive force (2) is measured in the same procedure as described above. The residual adhesion rate is obtained by the following formula.
Residual adhesion rate (%) = Adhesive strength (1) ÷ Adhesive strength (2) × 100

(4) Release characteristics (practical alternative evaluation):
An acrylic pressure-sensitive adhesive composition having the following composition was applied to the release film, followed by heat treatment at 100 ° C. for 5 minutes to obtain a pressure-sensitive adhesive layer having a thickness (after drying) of 20 μm. Thereafter, the release film and the adhesive layer bonded product were heat-treated at 150 ° C. for 90 minutes, and then the release film was peeled off, and the release characteristics were evaluated from the situation when the release film was peeled off from the adhesive layer.
A: The release film peels cleanly, and the phenomenon that the adhesive adheres to the release layer is not seen.
B: The release film peels off, but the adhesive adheres to the release layer when peeled off at a high speed.
C: Adhesive adheres to the release film and does not peel off well.

(5) Amount of polyester oligomer (OL) extracted from the surface of the release layer of the release film:
In advance, an unheat-treated release film is heated in air at 180 ° C. for 10 minutes. After that, the heat-treated film is brought into close contact with the inner surface of a box having a top and width of 10 cm and a height of 3 cm, and the box shape is obtained. When the coating layer is provided, the coating layer surface is set to the inside. Next, 4 ml of DMF (dimethylformamide) is placed in the box prepared by the above method and left for 3 minutes, and then DMF is recovered. The recovered DMF was supplied to liquid chromatography (manufactured by Shimadzu Corporation: LC-7A) to determine the amount of oligomer in DMF, and this value was divided by the area of the film in contact with DMF to determine the amount of oligomer on the film surface (mg / M ² ).

The amount of oligomer in DMF was determined from the peak area ratio between the standard sample peak area and the measured sample peak area (absolute calibration curve method). The standard sample was prepared by accurately weighing the oligomer (cyclic trimer) collected in advance and dissolving it in DMF accurately measured. The concentration of the standard sample is preferably in the range of 0.001 to 0.01 mg / ml.

The conditions for the liquid chromatograph were as follows.
Mobile phase A: Acetonitrile Mobile phase B: 2% acetic acid aqueous solution Column: “MCI GEL ODS 1HU” manufactured by Mitsubishi Chemical Corporation
Column temperature: 40 ° C
Flow rate: 1 ml / min Detection wavelength: 254 nm

Thereafter, the peeling condition was determined according to the following criteria.
<Criteria>
A: Surface oligomer amount (OL) is 2.0 mg / m ² or less (a level that causes no problem in practical use)
B: Surface oligomer amount (OL) exceeds 2.0 mg / m ² (practically problematic level)

(6) Element amount from the release surface side of the release film:
The following table is prepared by the FP (Fundamental Parameter Method) method using a fluorescent X-ray measurement apparatus (model “XRF-1500” manufactured by Shimadzu Corporation) from the surface provided with the release layer of the sample sample in advance. The element amount was measured under the measurement conditions shown in 1.

(7) Initial evaluation of coating film adhesion of release film (practical property substitution evaluation):
The release surface of the sample film immediately after coating was rubbed 5 times with a tentacle, and the degree of release of the release layer was determined according to the following criteria.
<Criteria>
A: Coating film is not removed (practical level)
B: The coating film turns white but does not fall off (practical level)
C: The drop of the coating was confirmed (practical level)

(8) Evaluation after release film adhesion test for release film (practical property substitution evaluation):
The sample film was left in a constant temperature and humidity chamber at 80 ° C. in a 90% RH atmosphere for 1 week, and then the sample film was taken out. Thereafter, the release surface of the sample film was rubbed 100 times with absorbent cotton soaked with MEK (methyl ethyl ketone) and then rubbed 5 times with a tentacle, and the degree of removal of the release layer was determined according to the following criteria.
<Criteria>
A: The coating film does not fall off at all, and there is no difference in peel strength between the rubbed part and the non-rubbed part (practical level).
B: The coating film was not removed at all, and the rubbed part was slightly heavier than the non-rubbed part (practical level)
C: The coating film became white but did not fall off, and the rubbed part was heavier than the rubbed part (practical level)
D: Dropping of the coating was confirmed (practically difficult level)

(9) Foreign matter inspection:
An optical substrate-less double-sided pressure-sensitive adhesive sheet provided with release films on both sides was observed to evaluate the foreign matter inspection.
A: There is no surface oligomer and the testability is good.
B: Surface oligomer is detected, but at a level that does not hinder inspection.
C: Many surface oligomers are detected and cannot be inspected well.

(10) Intrinsic viscosity (dl / g) of polyester:
1 g of polyester from which other polymer components and pigments incompatible with polyester were removed was precisely weighed, 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) was added and dissolved, and measurement was performed at 30 ° C.

(11) Glass transition temperature (Tg) of polyester resin:
Using a DSC-II type measuring device manufactured by Perkin Elmer, the sample was heated at a rate of temperature increase of 10 ° C./min under a sample weight of 10 mg and a nitrogen stream, and the baseline start temperature of the baseline was defined as Tg.

(12) Release force of release film (II):
An adhesive tape (“No. 31B” manufactured by Nitto Denko) is attached to the surface of the release layer of the sample film, then cut to a size of 50 mm × 300 mm, and the peel force after standing at room temperature for 1 hour is measured. The peel force was measured using a high-speed peel tester (Tester Sangyo Co., Ltd., high-speed peel tester “TE-702 type”). In the manner of peeling the 31B adhesive tape, 180 ° peeling was performed under each measurement condition of peeling speed of 0.3 m / min and 60 m / min.

(13) Coating film adhesion of release film (practical property substitution evaluation):
The sample film was left in a constant temperature and humidity chamber at 60 ° C. and 80% RH for 4 weeks, and then the sample film was taken out. Thereafter, the release surface of the sample film was rubbed with a tentacle five times, and the degree of release of the release layer was determined according to the following criteria.
<Criteria>
A: Coating film is not removed (practical level)
B: The coating film turns white but does not fall off (practical level)
C: The drop of the coating was confirmed (practical level)

(14) Evaluation of peelability of first release film and second release film:
(Practical property substitution evaluation)
At the time of peeling the first release film, sensory evaluation was performed according to the following criteria for the situation of the interface between the second release layer and the pressure-sensitive adhesive layer.
<Criteria>
A: No abnormality is observed at the interface between the second release layer and the pressure-sensitive adhesive layer (a level that causes no problem in practice).
B: Slight floating is observed at the interface between the second release layer and the pressure-sensitive adhesive layer (a level that may cause a practical problem).
C: Clear floating is observed at the interface between the second release layer and the pressure-sensitive adhesive layer (practically problematic level).

(15) Migration assessment:
In the production of the substrate-less double-sided pressure-sensitive adhesive sheet, the presence or absence of roll dirt was confirmed, and sensory evaluation was performed according to the following criteria.
<Criteria>
A: The roll is not soiled (practically problematic level).
B: The roll is a migration component and is slightly soiled (a level that may cause a practical problem).
C: The roll is soiled with transfer components and causes transfer stain (practically problematic level).

(16) Surface resistivity (R) of release film:
Based on the following method (6-1), the surface resistivity of the sample film on the surface of the release layer was measured. In the method (6-1), since the surface resistivity higher than 1 × 10 ⁸ Ω cannot be measured, the method (6-2) was used for the sample that could not be measured in (6-1).
"Measuring method"
(6-1) Low resistivity meter manufactured by Mitsubishi Chemical Co., Ltd .: Loresta GP MCP-T600 was used, the sample was conditioned for 30 minutes in a measurement atmosphere of 23 ° C. and 50% RH, and then the surface resistivity was measured.
(6-2) Using a high resistance measuring instrument manufactured by Hewlett-Packard Japan: HP4339B and measuring electrode: HP16008B, the sample was conditioned in a measurement atmosphere at 23 ° C. and 50% RH for 30 minutes, and the surface resistivity was measured. did.
<Criteria>
A: R (Ω) is 1 × 10 ⁸ or less (practical level, particularly good)
B: R (Ω) is 1 × 10 ⁹ or less (practical level)
C: R (Ω) is 1 × 10 ¹⁰ or less (a level that may cause a problem in practical use)
D: R (Ω) exceeds 1 × 10 ¹⁰ (practical level)

The polyester used in the examples and comparative examples was prepared as follows.
<Manufacture of polyester>
・ Polyester (1)
Using 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol as starting materials, 0.09 parts by weight of magnesium acetate tetrahydrate as a catalyst is placed in the reactor, the reaction start temperature is set to 150 ° C., and the methanol is distilled off gradually. The reaction temperature was raised to 230 ° C. after 3 hours. After 4 hours, the transesterification reaction was substantially terminated. After adding 0.04 part of ethyl acid phosphate to the reaction mixture, 0.06 part of silica particles dispersed in ethylene glycol having an average particle diameter of 1.6 μm and 0.04 part of antimony trioxide were added, and 4 A time polycondensation reaction was performed. That is, the temperature was gradually raised from 230 ° C. to 280 ° C. On the other hand, the pressure was gradually reduced from normal pressure, and finally 0.3 mmHg. After 4 hours from the start of the reaction, the reaction was stopped and the polymer was discharged under nitrogen pressure. The intrinsic viscosity of the obtained polyester (1) was 0.53.

Example 1-1
<Manufacture of polyester film>
The polyester (1) as a raw material is supplied to an extruder with a vent, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 550 μm was obtained.
This film was stretched 3.7 times in the longitudinal direction at 85 ° C., stretched 3.9 times in the transverse direction at 100 ° C., and heat treated at 210 ° C. to obtain a biaxially stretched polyester film having a thickness of 38 μm.

A release agent composed of release agent composition-A shown below was applied to the obtained polyester film by a reverse gravure coating method so that the coating amount (after drying) was 0.12 g / m ² , and a dryer temperature of 150 A roll-shaped release polyester film was obtained under the conditions of ° C and a line speed of 30 m / min.

<Release agent compound>
A1: A curable silicone resin of the above general formula (I) having a ratio of methyl group, hexenyl group and phenyl group of 100: 1: 0.1 (molecular weight 200000)
A2: a curable silicone resin of the above general formula (II) in which the ratio of methyl group to vinyl group is 100: 0.2 (molecular weight 200000)
A3: curable silicone resin of general formula (III) in which the ratio of methyl group to hydrosilyl group is 100: 1.5 (molecular weight 200000)
A4: curable silicone resin of general formula (III) in which the ratio of methyl group to hydrosilyl group is 100: 0.4 (molecular weight 200000)
B1: Unreactive silicone resin of the general formula (IV) (molecular weight 80000)
・ C1: Addition type platinum catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.)

<Releasing agent composition-A>
Curable silicone resin a1 20 parts Unreactive silicone resin b1 0.2 part addition type platinum catalyst c1 0.2 part MEK / toluene mixed solvent (mixing ratio is 1: 1)

Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-7:
A release film was obtained in the same manner as in Example 1 except that the release agent composition in Example 1-1 was changed to the coating composition shown in Table 2 below. The obtained results are summarized in Table 3 below.

Example 2-1
A biaxially stretched polyester film having a thickness of 38 μm was obtained in the same manner as Example 1-1.
Next, the following coating agent was applied by a reverse gravure coating method so that the coating amount (after drying) was 0.05 g / m ^2, and then heat-treated at 120 ° C. for 30 seconds.
Examples of compounds constituting the coating layer are as follows.

(Example compounds)
-Organic compound having an aluminum element: (A1)
Aluminum tris (ethyl acetoacetate)
・ Organic compound containing tin element: (A2)
Dioctyldiacetoxytin / organosilicon compound: (B1)
2- (3,4-Epoxycyclohexyl) ethyltrimethoxysilane

<Coating composition>
Organic compound having aluminum element (A1): 33% by weight
Organosilicon compound (B1): 67% by weight
The coating agent was diluted with a toluene / MEK mixed solvent (mixing ratio was 1: 4) to 4 wt%.

Thereafter, a release agent having a release agent composition shown below is applied on the coating layer by a reverse gravure coating method so that the coating amount (after drying) is 0.12 g / m ² , the dryer temperature is 150 ° C., the line A roll-shaped release polyester film was obtained under the condition of a speed of 30 m / min.

<Release agent compound>
a1: Curable silicone resin of the above general formula (I) (molecular weight 200000) in which the ratio of methyl group, hexenyl group and phenyl group is 100: 1: 0.1
a2: A curable silicone resin of the general formula (II) having a ratio of methyl group to vinyl group of 100: 0.2 (molecular weight 200000)
a3: The curable silicone resin of the general formula (III) having a ratio of methyl group to hydrosilyl group of 100: 1.5 (molecular weight 200000)
a4: Curable silicone resin of the above general formula (III) having a ratio of methyl group to hydrosilyl group of 100: 0.4 (molecular weight 200000)
b1: Unreactive silicone resin of the general formula (IV) (molecular weight 80000)
c1: Addition type platinum catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.)

Examples 2-2 to 2-8 and comparative examples 2-1 to 2-9:
In Example 2-1, the coating agent composition was changed to the coating agent composition shown in Table 4 below, and the releasing agent composition was changed to the release agent composition shown in Table 5 below, in the same manner as in Example 2-1. A release film was obtained. The properties of the release films obtained in the above examples and comparative examples are shown in Table 6 below.

Example 3-1
(Manufacture of polyester film)
・ Polyester film-1 (50μm)
The polyester (1) as a raw material is supplied to an extruder with a vent, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 600 μm was obtained. This film was stretched 3.3 times in the machine direction at 85 ° C., stretched 3.6 times in the transverse direction at 100 ° C., and heat-treated at 210 ° C. to obtain a biaxially stretched polyester film having a thickness of 50 μm.

・ Polyester film-2 (100μm)
The polyester (1) as a raw material is supplied to an extruder with a vent, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 1200 μm was obtained. This film was stretched 3.3 times in the machine direction at 85 ° C., stretched 3.6 times in the transverse direction at 100 ° C., and heat-treated at 210 ° C. to obtain a biaxially stretched polyester film having a thickness of 100 μm.

<Manufacture of first release film>
A release agent comprising the following release agent composition A was applied to polyester film-1 by a reverse gravure coating method so that the coating amount (after drying) was 0.1 g / m ^2, and heat-treated at 150 ° C. for 30 seconds. A first release film was obtained later.

<Release agent compound>
a1: Curing type silicone resin (LTC310: manufactured by Toray Dow Corning)
a2: curable silicone resin (LTC303E: manufactured by Toray Dow Corning, transition component content 15%)
a3: curable silicone resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.)
a4: curable silicone resin (SD-7292: manufactured by Toray Dow Corning)
b1: Unreactive silicone resin having a mass average molecular weight of 400,000 or more c1: Addition type platinum catalyst (SRX212: manufactured by Toray Dow Corning)
c2: Addition type platinum catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.)

<Manufacture of second release film>
A release agent comprising the following release agent composition B was applied to polyester film-2 by a reverse gravure coating method so that the coating amount (after drying) was 0.1 g / m ² and heat-treated at 150 ° C. for 30 seconds. Later, a second release film was obtained.

<Releasing agent composition-B>
Curable silicone resin a3 19 parts Curable silicone resin a4 1 part Addition type platinum catalyst c1 0.2 part MEK / toluene mixed solvent (mixing ratio is 1: 1)

<Manufacture of substrate-less double-sided PSA sheet>
On the release layer of the obtained 2nd release film, after apply | coating the coating liquid comprised from the following acrylic adhesive composition, it heat-processed for 5 minutes at 100 degreeC, and the application quantity (after drying) is 50 micrometers. The pressure-sensitive adhesive layer was obtained.

<Adhesive layer forming composition>
Acrylate ester copolymer (Mw = 540000 Mn = 67000 Mw / Mn = 8) obtained by random copolymerization of three components of 75 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of vinyl acetate, and 5 parts by mass of acrylic acid Tg-50 ° C) 1 kg was mixed with 20 g of 4-phenylbenzophenone as a photopolymerization initiator to form an adhesive layer.

Next, the first release film was bonded to the exposed adhesive layer surface to obtain a substrate-less double-sided adhesive sheet.

Examples 3-2 to 3-4 and Comparative Examples 3-1 to 3-4:
In Example 3-1, except that the release agent composition and the polyester film substrate thickness were changed as shown in Tables 7 and 8 below, the production was performed in the same manner as in Example 3-1, and the first release film, A two release film was obtained. Then, it bonded together through the adhesive layer using both, and obtained the base material-less double-sided adhesive sheet. Table 8 shows the characteristics of the release films obtained in the above Examples and Comparative Examples.

Example 4-1
(Manufacture of polyester film)
・ Polyester film-1 (50μm)
The polyester (1) as a raw material is supplied to an extruder with a vent, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 600 μm was obtained. The film was stretched 3.3 times in the longitudinal direction at 85 ° C., and a coating layer composed of the following coating agent composition was applied so that the coating thickness (after drying) was 0.03 g / m ² , and then 100 ° C. The film was stretched 3.6 times in the transverse direction and heat treated at 210 ° C. to obtain a biaxially stretched polyester film having a thickness of 50 μm.

・ Polyester film-2 (100μm)
The polyester (1) as a raw material is supplied to an extruder with a vent, melt-extruded at 290 ° C., and then cooled and solidified on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. An amorphous film having a thickness of about 1200 μm was obtained. The film was stretched 3.3 times in the longitudinal direction at 85 ° C., and a coating layer composed of the following coating agent composition was applied so that the coating thickness (after drying) was 0.03 g / m ² , and then 100 ° C. The film was stretched 3.6 times in the transverse direction and heat-treated at 210 ° C. to obtain a biaxially stretched polyester film having a thickness of 100 μm.

<Coating composition>
(A): Baytron PAG manufactured by Starck Co., Ltd., consisting of polyethylene dioxythiophene and polystyrene sulfonic acid
(B): Polyurethane resin A polyester polyol comprising 664 parts of terephthalic acid, 631 parts of isophthalic acid, 472 parts of 1,4-butanediol, and 447 parts of neopentyl glycol was obtained. Next, 321 parts of adipic acid and 268 parts of dimethylolpropionic acid were added to the obtained polyester polyol to obtain a pendant carboxyl group-containing polyester polyol. Further, 160 parts of hexamethylene diisocyanate was added to 1880 parts of the polyester polyol to obtain an aqueous polyurethane resin coating.
(C): Glycerin where n = 1 in the formula (3)

A / B / C = 40/40/20 (% by weight)

<Manufacture of first release film>
A release agent comprising the following release agent composition A was applied to polyester film-1 by a reverse gravure coating method so that the coating amount (after drying) was 0.1 g / m ^2, and heat-treated at 150 ° C. for 30 seconds. A first release film was obtained later.
<Release agent compound>
a1: Curing type silicone resin (LTC310: manufactured by Toray Dow Corning)
a2: curable silicone resin (LTC303E: manufactured by Toray Dow Corning, transition component content 15%)
a3: curable silicone resin (KS-847H: manufactured by Shin-Etsu Chemical Co., Ltd.)
a4: curable silicone resin (SD-7292: manufactured by Toray Dow Corning)
b1: Unreactive silicone resin having a mass average molecular weight of 400,000 or more c1: Addition type platinum catalyst (SRX212: manufactured by Toray Dow Corning)
c2: Addition type platinum catalyst (PL-50T: manufactured by Shin-Etsu Chemical Co., Ltd.)

Examples 4-2 to 4-5 and comparative examples 4-1 to 4-6:
In Example 4-1, a coating agent composition, a release agent composition, and a polyester film substrate thickness were prepared in the same manner as in Example 4-1, except that the thicknesses were changed as shown in Tables 9 and 10 below. A mold film and a second release film were obtained. Then, it bonded together through the adhesive layer using both, and obtained the base material-less double-sided adhesive sheet. The characteristics of the release films obtained in the above examples and comparative examples are shown in Tables 11 and 12 below.

The release film of the present invention has good releasability from the pressure-sensitive adhesive and less migration, for example, for polarizing plate and retardation plate used for liquid crystal display (LCD) for manufacturing capacitive touch panels. In addition to the production of various display components, such as for the production of LCD components such as, for the production of plasma display panel components, for the production of organic electroluminescence components, etc., it can be suitably used for various adhesive layer protection applications.

DESCRIPTION OF SYMBOLS 1 Substrate-less double-sided pressure-sensitive adhesive sheet 2 Adhesive layer 3 First release film substrate 4 First release agent layer 5 Second release film substrate 6 Second release agent layer 7 First release film (light release side)
8 Second release film (heavy release side)

Claims

A release film having a silicone release layer formed from a coating solution containing a reactive silicone resin having a functional group, an unreactive silicone resin, and a platinum catalyst on one side of the polyester film .
The silicone release layer includes a reactive silicone resin having a hexenyl group, a vinyl group, a phenyl group, and a hydrosilyl group as functional groups, an unreactive silicone resin having a mass average molecular weight of 50,000 to 100,000, a platinum catalyst, The release film of Claim 1 formed from the coating liquid containing this.
A release film in which a coating layer and the silicone-based release layer are sequentially provided on one side of a polyester film, the coating layer contains an organosilicon compound, and the silicone after heating the release film at 180 ° C. for 10 minutes The release film according to claim 1 or 2, wherein the amount of the polyester oligomer on the surface of the release layer is 2.0 mg / m 2 or less.
The release film according to claim 3, wherein the coating layer contains an organic compound containing aluminum.
The silicone release layer is formed from a coating solution containing a reactive silicone resin having an alkenyl group and an alkyl group as a functional group, an unreactive silicone resin having a mass average molecular weight of 400,000 or more, and a platinum catalyst. The release film according to claim 1.
The base material by which the release film (1st release film) of Claim 5 is laminated | stacked in order of the adhesive layer and the release film (2nd release film) whose peeling force is larger than the said 1st release film. A double-sided adhesive sheet,
In the first release film and the adhesive layer, a low-speed peel force of 0.3 m / min is 10 to 20 mN / cm, and a high-speed peel force of 60 m / min is 90 mN / cm or less. Material-less double-sided adhesive sheet.
The coating layer containing a conductive compound (A) and a binder polymer (B) is laminated on the polyester film of the first release film, and the release layer is laminated on the coating layer. The base-material-less double-sided adhesive sheet of description.