JP2009073937A - Double-sided self-adhesive sheet, manufacturing method for it, and usage of it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided self-adhesive sheet having excellent adhesiveness, in particular, hot water resistant adhesiveness between a silicone self-adhesive layer and a base material film while having properly regulated peel strength between the silicone self-adhesive layer and a separate film, to provide a method for efficiently and economically manufacturing the double-side self-adhesive sheet, and to provide preferable usage of the double-sided self-adhesive sheet. <P>SOLUTION: In this double-sided self-adhesive sheet, a polyester film A, a mold release layer B, the self-adhesive layer C containing a cross-linked silicone compound having a polydimethylsiloxane skeleton, a hot water-resistant adhesiveness improvement layer D, a polyester base material film E, an acrylic self-adhesive layer F, and the separate film G are layered in this order A-G. The peel strength, which is measured by a specific method, between the mold release layer B and the adhesive layer C is 0.03-1.0 N/20 mm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a double-sided pressure-sensitive adhesive sheet and a method for producing the same, and more specifically, has a pressure-sensitive adhesive layer excellent in sticking property and removability, and excellent in heat-resistant water adhesion between the pressure-sensitive adhesive layer and a substrate film. In addition, the present invention relates to a double-sided pressure-sensitive adhesive sheet in which the peel strength between the pressure-sensitive adhesive layer and the separate film is appropriately controlled, and further relates to an economical production method of this double-sided pressure-sensitive adhesive sheet and a preferred method of using the same.

  A pressure-sensitive adhesive sheet having a silicone rubber layer as a pressure-sensitive adhesive layer has excellent adhesion and removability, and is therefore used in a wide range of fields as a pressure-sensitive adhesive sheet that requires removability (repairability). Various films having a silicone adhesive layer using a silicone rubber compound as a raw material have already been disclosed by the present inventors (see, for example, Patent Documents 1 to 4).

  The film described in each patent document is suitably used in various applications. However, in recent years, along with the spread of its applications, there are cases where it does not satisfy the market requirements for quality and price, and improvements have been demanded.

  For example, when an adhesive sheet is used as a touch panel member, in car navigation applications, etc., the temperature inside the vehicle varies considerably from low to high, so it is necessary to withstand harsh usage conditions. There was room for improvement in the durability of adhesion between the material films.

  The pressure-sensitive adhesive sheet is shipped in a form in which a separate film is laminated on the surface of the pressure-sensitive adhesive layer in order to enhance its handleability, and is used by peeling off the separate film and actually sticking it to the target article when actually used. Depending on the application, there is a strong demand for reducing the peeling force. However, if the peel strength of the separate film is too small, when the sheet is wound in the production process of the adhesive sheet, partial separation of the separate film occurs, and an air layer enters in a direction perpendicular to the sheet winding direction. The so-called channeling phenomenon may occur. Further, in optical applications, the adhesive sheet is required to have a high degree of transparency and stability, but there are cases where it is difficult to cope with it.

  The raw material of the silicone rubber disclosed in the above patent document is a millable type silicone rubber compound. Such a compound has a reduced solubility in a solvent depending on the storage state, and a silicone rubber layer is applied. When processed, appearance quality may deteriorate due to undissolved materials. In addition, the coating solution in which silicone rubber compound is dissolved in a solvent has various problems in quality stabilization and stable production, such as gelation of the solution depending on the storage condition, making it impossible to use as a coating solution. It has become an obstacle to answering the demand for cost reduction, and there is a strong envy for solving these problems.

  On the other hand, it is disclosed that a double-sided pressure-sensitive adhesive sheet having an acrylic pressure-sensitive adhesive layer formed on the opposite surface of the silicone rubber layer of the pressure-sensitive adhesive sheet using the silicone rubber layer as a pressure-sensitive adhesive layer is used as a touch panel member (for example, Patent Document 5). reference).

The above double-sided pressure-sensitive adhesive sheet also has the same problem as the pressure-sensitive adhesive sheet using the silicone rubber layer as the pressure-sensitive adhesive layer with respect to the pressure-sensitive adhesive layer made of the silicone rubber layer. Moreover, in this patent document 5, the detailed description of the formation method of a silicone rubber adhesion layer is not carried out, and it does not mention at all about the above-mentioned problem-solving means.
JP-A-11-320762 JP 2000-56694 A JP 2001-83886 A JP 2001-139903 A JP 2003-150316 A

  Therefore, in the present invention, to provide a double-sided pressure-sensitive adhesive sheet that is excellent in adhesiveness between the silicone pressure-sensitive adhesive layer and the base film, in particular, heat-resistant water adhesiveness, and the peeling force between the silicone pressure-sensitive adhesive layer and the separate film is appropriately controlled, An object was to provide a method for efficiently and economically producing the double-sided pressure-sensitive adhesive sheet and a method for using the method.

  The double-sided pressure-sensitive adhesive sheet of the present invention that has solved the above problems includes a polyester film (A), a release layer (B), a pressure-sensitive adhesive layer (C) containing a crosslinked silicone compound having a polydimethylsiloxane skeleton, and improved hot water adhesion. A layer (D), a polyester base film (E), an acrylic pressure-sensitive adhesive layer (F), and a separate film (G) are double-sided pressure-sensitive adhesive sheets laminated in the order of A to G, and are measured by the method described later. The peeling strength between the release layer (B) and the adhesive layer (C) to be used is summarized as 0.03 to 1.0 N / 20 mm.

  The release layer (B) is preferably made of a non-silicone compound, and more preferably a layer containing a binder resin, a polymer wax component and an antistatic agent.

  The heat resistant water adhesion improving layer (D) preferably contains a reaction product of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent. One or more self-crosslinking polymers selected from the group consisting of polyester, polyurethane, and acrylic polymers of the type may include those that are self-crosslinked.

  The crosslinked silicone compound is preferably a crosslinked silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000.

  Furthermore, the double-sided pressure-sensitive adhesive tape from which the pressure-sensitive adhesive layer (C) does not peel when the hot water adhesion is evaluated by a method described later is preferable.

There are several methods of the present invention for producing the double-sided pressure-sensitive adhesive sheet as will be described later.
A step of laminating the heat resistant water adhesion improving layer (D) on one side of the polyester base film (E) to form a laminate (1);
A step of forming a laminate (2) by laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the heat resistant water adhesion improving layer (D) of the laminate (1);
A step of laminating the release layer (B) on one side of the polyester film (A) to form a laminate (3);
The laminates (2) and (3) are formed so that the release layer (B) of the laminate (3) is in contact with the surface of the layer (2) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton. ) To form a laminate (4),
A step of crosslinking a non-crosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (4) to form a laminate (4 ′) having an adhesive layer (C);
On the surface of the polyester base film (E) of the laminate (4 ′), with or without another heat resistant water adhesion improving layer (D), an acrylic pressure-sensitive adhesive layer (F) and a separate film ( G) are laminated in this order,
Including the gist.

  In the present invention, the double-sided pressure-sensitive adhesive sheet is used for adhering an overlay sheet and a coordinate detection sheet of a capacitive touch panel, and the double-sided pressure-sensitive adhesive sheet is used as a resistor. The usage method of the double-sided adhesive sheet characterized by using for the adhesion | attachment of the touch panel of a membrane type touch panel and a display apparatus is also included.

  The double-sided pressure-sensitive adhesive sheet of the present invention is formed with a pressure-sensitive adhesive layer containing a cross-linked silicone compound having a polydimethylsiloxane skeleton having both sticking property and re-peeling property. In the case where a failure occurs in a member bonded with an adhesive sheet, the bonded member can be easily removed and re-bonded. Therefore, for example, it can be suitably used as a double-sided pressure-sensitive adhesive sheet for bonding expensive members. Moreover, since the transparency of the double-sided pressure-sensitive adhesive sheet of the present invention is extremely high, it can be suitably used for laminating optical members.

  Furthermore, since the double-sided pressure-sensitive adhesive sheet of the present invention is provided with a heat-resistant water adhesion improving layer between the pressure-sensitive adhesive layer and the base polyester film, it has excellent adhesion durability and is a member used under harsh conditions. It can also be suitably used for bonding. In addition, the peeling force of the separate film laminated on the surface of the silicone adhesive layer is controlled to an appropriate range, and the occurrence of the above-mentioned channeling phenomenon is suppressed in the process of winding the double-sided adhesive sheet. A quality double-sided PSA sheet can be produced stably. Moreover, it is excellent also in the workability | operativity at the time of bonding a member using a double-sided adhesive sheet.

  Moreover, the manufacturing method of the double-sided adhesive sheet of this invention can manufacture the double-sided adhesive sheet which has the said characteristic economically. In particular, since the adhesive layer is formed by crosslinking an uncrosslinked polydimethylsiloxane skeleton silicone compound, it is more transparent than a silicone rubber layer made from a conventionally known millable silicone rubber compound. In addition, since it is excellent in clarity and operability, it has a feature that it is excellent in cost performance as compared with a conventionally known method.

  Furthermore, since the double-sided pressure-sensitive adhesive sheet is excellent in repairability, if it is used for adhering a member of a capacitive type or resistive film type touch panel, it is possible to reduce a decrease in product yield due to a sticking mistake. . In addition, the adhesive layer is firmly bonded to the base film through the heat resistant water adhesion improving layer, and the adhesive layer has excellent cushioning properties, improving the reliability and durability of the touch panel. Can be made. Therefore, by implementing the method for using the double-sided pressure-sensitive adhesive sheet of the present invention, it has become possible to provide such a high-performance touch panel.

  The double-sided pressure-sensitive adhesive sheet of the present invention comprises a polyester film (A), a release layer (B), a pressure-sensitive adhesive layer (C) containing a crosslinked silicone compound having a polydimethylsiloxane skeleton, a heat resistant water adhesion improving layer (D), The said mold release which is a double-sided adhesive sheet by which the polyester-type base film (E), the acrylic adhesive layer (F), and the separate film (G) were laminated | stacked in order of AG, and is measured by the method mentioned later. The peel strength between the layer (B) and the adhesive layer (C) is 0.03 to 1.0 N / 20 mm.

[Polyester film (A) and polyester base film (E)]
As a polyester film (A) and a polyester-type base film (E), if it has polyethylene terephthalate, a polyethylene naphthalate, a polybutylene terephthalate etc. as a main component (80 mass% or more), it can be used arbitrarily. A biaxially stretched one is desirably used. The production method of the biaxially stretched polyester film is not particularly limited. For example, after drying the polyester as necessary, it is supplied to a known melt extruder, extruded from a slit-shaped die into a sheet, electrostatic application, etc. In this manner, the unstretched sheet may be stretched after being brought into close contact with the casting drum, cooled and solidified to obtain an unstretched sheet. The biaxial stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching.

  The polyester base film (E) may be subjected to known adhesion improving treatment such as corona treatment, flame treatment, plasma treatment and the like.

[Peel strength between release layer (B) and adhesive layer (C)]
In the double-sided pressure-sensitive adhesive sheet of the present invention, the peel strength between the release layer (B) and the pressure-sensitive adhesive layer (C) is 0.03 to 1.0 N / 20 mm. When the peel strength is 0.03 N / 20 mm or more, it exhibits good peelability, and when the double-sided pressure-sensitive adhesive sheet is wound up, the separation film (AB) can be prevented from floating, and the quality of the double-sided pressure-sensitive adhesive sheet can be improved. Can be kept high. On the other hand, if it is 1.0 N / 20 mm or less, the peelability of the separate film (AB) consisting of the polyester film (A) and the release layer (B) is good. In order to control the peel strength within the above range, a release layer (B) having the following constitution is preferably provided on the surface of the polyester film (A). The peel strength was measured as follows.

  First, the surface (two surfaces) on which the peel strength of a double-sided pressure-sensitive adhesive sheet having a length of about 200 mm and a width of 20 mm is to be measured is exposed, and the double-sided pressure-sensitive adhesive sheet comprises a laminate including one surface and a laminate including the other surface Each is set on the chuck of a tensile tester. That is, for example, when measuring the peel strength at the interface between the release layer (B) and the pressure-sensitive adhesive layer (C), the double-sided pressure-sensitive adhesive sheet is slightly peeled off at the interface between the release layer (B) and the pressure-sensitive adhesive layer (C), Each of the release layer (B) and the adhesive layer (C) is exposed. In this case, the separate film (AB) composed of the polyester film (A) and the release layer (B) is held by one chuck, and the adhesive layer (C) to the separate film (G) are held by one chuck. Hold the laminate. And T-type peeling strength was measured by the method as described in JIS K6854-3. The tensile tester used was a trade name “Autograph” (manufactured by Shimadzu Corporation), and a T-type peel test was performed under conditions of a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film was lifted with a bar so that the T-shape was maintained. The maximum strength at the time of T-type peeling was defined as the peeling strength.

[Release layer (B)]
The release layer (B) in the double-sided pressure-sensitive adhesive sheet of the present invention is only required to have a peel strength satisfying the above range, and is made of a non-silicone compound in consideration of peelability from the pressure-sensitive adhesive layer (C). It is preferable. When the release layer (B) is made of a cured product of a curable silicone compound that is widely used as a release layer, since the affinity with the adhesive layer (C) is high, the silicone compound of the adhesive layer (C) When making it bridge | crosslink, an adhesive layer (C) and a mold release layer (B) may carry out a crosslinking reaction, and peelability may fall. In order to obtain stable peelability, the release layer is preferably formed using a release agent that does not substantially contain a silicone compound. Here, “the release layer is made of a non-silicone compound” means that the release layer is formed from a compound (or composition) containing 10% by mass or less of a silicone compound, and more preferable silicone. The compound amount is 5% by mass or less, and the silicone compound is most preferably 0% by mass.

  The release layer (B) may be made of a metal or an inorganic thin film. However, from the viewpoint of peel stability and cost, the release layer (B) is made of a composition containing a binder resin, a polymer wax component and an antistatic agent. It is preferable that This release layer (B) is a set with the polyester film (A) and becomes a separate film (AB) of the adhesive layer (C). The binder resin is preferably one or more polymers selected from the group consisting of polyesters, polyurethanes and acrylic polymers. These polymers may be used alone, or two or three different types may be used. May be used in combination.

  As the polyester, polyurethane, and acrylic polymer, the same polymers as those described later can be used as the constituent polymer of the heat resistant water adhesion improving layer (D). Although the binder resin has a low necessity for crosslinking, a crosslinking agent may be used in the same manner as in the heat resistant water adhesion improving layer (D), or a self-crosslinking polymer may be used.

  As the polymer wax component used in the present invention, conventionally known materials can be used. For example, wax emulsions such as polyethylene, polypropylene, acrylic, and fatty acid are shown, but a polymer wax agent that is particularly hard and does not have a sticky feeling and has excellent thermal decomposition stability is effective in improving peelability. Further, it is preferable because the transfer of wax to the opposite surface can be suppressed during film winding. Moreover, the preferable number average molecular weights of these wax agents are 1000-10000, More preferably, it is the range of 1500-6000.

  The polymer wax component is preferably contained in a solid content of 2 to 10% by mass when the total with the binder resin is 100% by mass. More preferably 3 to 8% by mass is contained. By making the addition amount of the polymer wax component 2% by mass or more, the peelability from the adhesive layer (C) after the crosslinking treatment can be improved, and the slipperiness of the separate film (AB) can be improved. . On the other hand, by setting the addition amount of the polymer wax component to 10% by mass or less, it is possible to maintain the peeling force and suppress the occurrence of the channeling phenomenon in the production process of the double-sided PSA sheet. Furthermore, since the migration of the polymer wax component from the release layer (B) can be suppressed, the surface of the pressure-sensitive adhesive layer (C) after the crosslinking treatment is less contaminated.

  The antistatic agent used in the release layer (B) is not particularly limited as long as it can be mixed with the binder resin or is compatible with the binder resin. For example, any of anionic, cationic, nonionic, amphoteric surfactants, polymeric surfactants, and the like can be used. Preferably, a polymer type antistatic agent with little bleed out to the laminated surface is preferred.

  As the polymer type antistatic agent, any of anionic type, cationic type and nonionic type can be used, and among them, anionic type and nonionic type polymeric antistatic agents are suitable.

  As the anionic polymer antistatic agent, for example, a polar polymer having at least one polar group selected from a sulfonic acid group, a carboxyl group, and a sulfate ester group or a salt thereof is preferable. The polar group needs 5 mol% or more per polymer molecule. These polar polymers having electrical conductivity may contain hydroxyl groups, amino groups, epoxy groups, aziridine groups, active methylene groups, sulfinic acid groups, aldehyde groups, and vinyl sulfone groups as polar groups. Among these, an antistatic agent containing styrene sulfonic acid or a salt thereof as a repeating unit is preferable.

  Examples of such an antistatic agent include polystyrene sulfonic acid or a salt thereof. Examples of the salt include ammonium salt, lithium salt, and sodium salt. Polystyrene sulfonic acid or a salt thereof is, for example, commercially available from Nippon SC under the trade name VERSA-TL (registered trademark) and various types of unneutralized salts having different molecular weights. Further, as an antistatic agent containing styrene sulfonic acid or a salt thereof as a repeating unit, a styrene sulfonic acid-maleic acid copolymer can also be used and is commercially available from Nippon SC.

  On the other hand, nonionic high molecular surfactants include aniline or derivatives thereof, pyrrole or derivatives thereof, isothianaphthene or derivatives thereof, acetylene or derivatives thereof, thiophene or derivatives thereof, and the like. Is preferred. Among them, a π-electron conjugated conductive polymer containing thiophene or a derivative thereof as a structural unit is preferable because it is less colored. The π-electron conjugated conductive polymer may be a homopolymer containing only one type of structural unit as a repeating unit or a copolymer containing two or more types of structural units as a repeating unit.

  Examples of the conductive polymer containing thiophene or a derivative thereof as a constitutional unit include, for example, “BYTRON (registered trademark) P” series manufactured by Starck Vitech, and “Denatron (registered trademark) P-502RG” manufactured by Nagase ChemteX. "Denatron (registered trademark) P-502S", Conisole F202, F205, F210, P810 (above, trade name) manufactured by Inscontec, CPS-AS-X03 (trade name) manufactured by Shin-Etsu Polymer, etc. are commercially available. .

  The blending amount of the antistatic agent in the release layer (B) cannot be uniquely determined because the preferred range varies depending on the type of the binder resin and the type of the antistatic agent, and the adhesive of the release layer (B). What is necessary is just to adjust the peeling strength from a layer (C) so that it may become the said range.

  For example, when an anionic surfactant is used as the antistatic agent, the blending amount of the antistatic agent is such that the peel strength of the release layer (B) from the adhesive layer (C) is within the above range. When the total amount with the binder resin is 100% by mass, the solid content is preferably 2 to 10% by mass, and more preferably 3 to 8% by mass. By making the blending amount of the anionic surfactant 2% by mass or more, the peelability from the adhesive layer (C) after the crosslinking treatment is improved and the antistatic property of the separate film (AB) is also improved. . On the other hand, by setting the blending amount of the antistatic agent to 10% by mass or less, it is possible to maintain the peeling force and suppress the occurrence of the channeling phenomenon in the production process of the double-sided PSA sheet. Furthermore, since the migration of the polymer wax component from the release layer (B) can be suppressed, the surface of the pressure-sensitive adhesive layer (C) after the crosslinking treatment is hardly contaminated.

  In order to form the release layer (B) having the above structure on the polyester film (A), a binder resin, a polymer wax component, an antistatic agent, and other additives such as a surface roughening material as required The resin composition may be prepared by mixing a predetermined amount in advance and coated. The resin composition may contain a surfactant for improving coatability, an ultraviolet ray inhibitor, an antioxidant, and the like. The coating method may be applied using a normal coating apparatus such as a gravure coater, reverse roll coater, reverse kiss coater, air knife coater, bar coater, etc., and the method is not limited to these. As in the case of the heat resistant water adhesion improving layer (D) described later, when obtaining the polyester film (A), the resin composition is applied to one side of the uniaxially stretched film (A). Examples thereof include a so-called in-line coating method in which stretching is performed in a direction perpendicular to uniaxial stretching, a so-called offline coating method in which coating is performed after biaxial stretching, and the like.

  The thickness of the release layer (B) is preferably 0.03 to 1 μm and more preferably 0.05 to 0.5 μm in a dry state in order to make the peeling force within an appropriate range.

[Adhesive layer (C)]
In the double-sided pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive layer (C) is in contact with the release layer (B). This adhesive layer (C) contains a crosslinked silicone compound having a polydimethylsiloxane skeleton as a main component (70% by mass or more, more preferably 90% by mass or more, and further preferably 100% by mass).

  The crosslinked silicone compound having the polydimethylsiloxane skeleton is preferably a crosslinked silicone compound having a number average molecular weight (Mn) of 50,000 to 500,000. The uncrosslinked Mn is more preferably 80,000 to 400,000, and more preferably 100,000 to 350,000.

  By using an uncrosslinked product of the silicone compound, solubility in a solvent and fluidity can be secured, and formation of the adhesive layer (C) is facilitated. Moreover, since Mn of 50,000 or more of an uncrosslinked body improves crosslinkability, it is suitable. When the Mn of the uncrosslinked product is 500,000 or less, deterioration in operability during production such as the viscosity of the coating solution becoming too high can be suppressed.

  As an uncrosslinked silicone compound satisfying the above contents, for example, a commercially available silicone oil can be used. When silicone oil is used, non-reactive dimethyl silicone oil is preferably used among straight silicone oils. Thereby, the silicone compound after crosslinking has a polydimethylsiloxane skeleton. The methyl phenyl type silicone oil has poor crosslinkability, and the reactive methyl hydrogen type silicone oil has poor storage stability, which may adversely affect the quality and operability. If it is less than (more preferably less than 5 mass%), you may mix | blend and use the silicone compound which does not have polydimethylsiloxane frame | skeleton, such as a methylphenyl type, a methyl hydrogen type, or various modified types.

  The uncrosslinked silicone compound may contain a polyalkylalkenylsiloxane skeleton silicone compound as long as it is less than 10% by mass. Most preferably, it consists only of a polydimethylsiloxane skeleton silicone compound that does not contain a polyalkylalkenylsiloxane skeleton silicone compound.

  The pressure-sensitive adhesive layer (C) in the present invention may contain a reinforcing agent such as silica as long as it does not interfere with the effects of the present invention, but it is particularly preferred that no reinforcing agent is contained.

  By using the above-mentioned uncrosslinked silicone compound, as described above, it is superior in terms of quality, quality stability, operability during production, etc., as compared with the case where a conventionally known millable type silicone compound is used as a raw material. The effect is manifested.

  The pressure-sensitive adhesive layer (C) includes an adhesion improver for increasing the adhesive strength between the pressure-sensitive adhesive layer (C) and the heat resistant water adhesion improving layer (D) and making it difficult to peel off the pressure-sensitive adhesive layer (C). It may be. As the adhesion improver, it is preferable to use a compound containing a reactive group active against radical reaction. Examples of this compound include (meth) acrylic acid derivatives and allyl derivatives. Among them, derivatives having 2 or more, particularly 3 or more unsaturated bonds are preferred. These compounds are widely used as rubber co-crosslinking agents, and examples include esters of polyhydric alcohol and (meth) acrylic acid, allyl esters of polycarboxylic acid, triallyl isocyanurate, triallyl cyanurate, and the like. .

  The ester of the polyhydric alcohol and (meth) acrylic acid is an ester compound obtained by esterifying two or more alcoholic hydroxyl groups of a polyhydric alcohol having two or more alcoholic hydroxyl groups with (meth) acrylic acid. Specifically, for example, ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 2,2′-bis [4- (meth) acryloxydiethoxyphenyl] propane, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethane di (meth) acrylate, tetramethylolmethanetri (meth) acrylate, Lame Chi roll tetra (meth) acrylate, dimer diol di (meth) acrylate and the like, particularly compounds containing three or more (meth) acryloyl group is preferred. In addition, although said compound illustrated each single ester compound of acrylic acid and methacrylic acid, the form of mixed ester of acrylic acid and methacrylic acid may be sufficient.

  Examples of the allyl ester of polyvalent carboxylic acid include phthalic acid diarylate, trimellitic acid diarylate, and pyromellitic acid tetraarylate.

  Any one of the above-mentioned adhesiveness improvers may be used alone, or two or more thereof may be used in combination. Further, the adhesion improver used in the present invention is not limited to the above exemplary compounds.

  0.2-20 mass parts is preferable with respect to 100 mass parts of silicone compound components, and, as for the compounding quantity of the said adhesive improvement agent, 0.5-10 mass parts is more preferable. By making the compounding amount of the adhesion improver 0.2 parts by mass or more, the effect of improving the hot water adhesion of the pressure-sensitive adhesive layer (C) is further increased. On the other hand, when the compounding amount of the adhesion improver exceeds 20 parts by mass, the effect of improving the hot water adhesiveness not only reaches saturation, but conversely, this effect may be deteriorated.

  The lower limit of the thickness of the adhesive layer (C) is preferably 3 μm, more preferably 5 μm, and even more preferably 8 μm from the viewpoint of adhesive strength. On the other hand, the upper limit of the thickness of the pressure-sensitive adhesive layer (C) may be determined within a range in which the pressure-sensitive adhesive force can be stably maintained from the viewpoint of economy. For example, 100 μm is preferable, 80 μm is more preferable, and 50 μm is further preferable.

  In the present invention, the method for forming the above-mentioned pressure-sensitive adhesive layer (C) is not limited, but the above-mentioned uncrosslinked silicone compound is dissolved or dispersed in a solvent, and an adhesion improver is added as necessary to apply the coating solution. It is a preferred embodiment that is prepared by applying a coating method, followed by crosslinking treatment.

  For example, uncrosslinked silicone oil dissolves well in aromatic hydrocarbons such as toluene. Therefore, it is preferable to dissolve in these solvents and apply by a coating method. When an uncrosslinked silicone oil is used, a compound plasticizing step by kneading or the like necessary for dissolving a conventional millable type silicone rubber compound in a solvent is unnecessary. In addition, the obtained coating solution has good storage stability, and does not cause a thickening phenomenon such as gelation, which is often seen when preparing a solution of a silicone rubber compound. Furthermore, since the production | generation of the foreign material by the silicone rubber compound not melt | dissolving which may generate | occur | produce in the solutionization of a silicone rubber compound is suppressed, there exists a merit that a coating liquid with high clarity is obtained.

  For example, the pressure-sensitive adhesive layer (C) is formed by applying a coating liquid containing the silicone oil or the like to the surface of the heat resistant water adhesion improving layer (D) formed on the surface of the polyester base film (E), or the polyester film ( It can form by apply | coating to the surface of the mold release layer (B) formed in the surface of A), and laminating | stacking another layer, or not laminating | stacking.

  The crosslinking method of the silicone compound may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as electron beams and γ rays. It is considered that when an active ray is irradiated on a silicone compound, hydrogen is extracted from the methyl group of polydimethylsiloxane, and a crosslinking reaction occurs between adjacent silicone compounds from which hydrogen is extracted from the methyl group. Therefore, in the crosslinking method using actinic radiation, it is not necessary to add an additive such as a peroxide for radical generation or a crosslinking catalyst to the silicone compound. For this reason, the contamination of the adherend due to the residue of these additives is suppressed, and it is not necessary to consider the pot life after blending the crosslinking catalyst, etc., so that the crosslinking is completed efficiently in a short time. There are merits such as higher.

  Among the actinic rays, the electron beam cross-linking method is preferable because of the availability of an irradiation device (EB irradiation device). As an electron beam irradiation amount in an EB irradiation apparatus, the range of 5-50 Mrad is preferable. By setting the electron beam irradiation amount to 5 Mrad or more, the crosslinking reaction of the silicone compound can be promoted, and the adhesive residue on the adherend can be reduced and the repairability can be improved when re-peeling. On the other hand, by setting the electron beam irradiation amount to 50 Mrad or less, it is possible to suppress a decrease in adhesiveness due to excessive progress of the crosslinking reaction.

  The lower limit of the adhesive strength of the adhesive layer (C) is 0.01 N / 20 mm (against a 180 ° peel test, a pulling speed of 300 mm / min) from the point of reliability when used for bonding articles. Preferably, it is 0.05 N / 20 mm. On the other hand, the upper limit of the adhesive strength of the adhesive layer (C) is preferably 1.0 N / 20 mm, more preferably 0.5 N / 20 mm from the viewpoint of improving removability and ensuring good repairability. is there. Moreover, it is preferable from the point of repair property that the adhesion layer does not remain on the glass surface when evaluated by the above evaluation method, that is, there is no adhesive residue.

[Heat resistant water adhesion]
A method for evaluating the heat-resistant water adhesion, which is an important effect of the double-sided PSA sheet of the present invention, will be described.

  The double-sided pressure-sensitive adhesive sheet is cut into 50 mm × 50 mm, and is a separate film composed of a polyester film (A) and a release layer (B) (hereinafter referred to as a separate film (AB) for distinction from the separate film (G)). To peel off. The sample is submerged in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water so that the adhesive layer (C) is on the lower side, and the entire sample is immersed in water. Put the lid on. In the case where the sample is not immersed in water by its own weight, for example, a polyester film having a size of 60 mm × 60 mm and a thickness of 188 μm may be placed on the sample and weighted. The size and material of the weight are not particularly limited, and the entire sample may be immersed in water. The container containing the sample is placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After the heat treatment, the container is taken out from the oven, and the sample is quickly taken out and rubbed 10 times by applying force with the finger pad from the adhesive layer (C) side to the end, and the adhesive layer (C) is a polyester base film (E ) Side, it was evaluated whether it peeled from the side. The case where the pressure-sensitive adhesive layer (C) was not peeled was marked with ◯, and the case where the pressure-sensitive adhesive layer (C) was peeled was marked with x. In this heat resistant water adhesion, by selecting a heat resistant water adhesion improving layer (D) that does not peel off the pressure sensitive adhesive layer (C), for example, when used as a member such as a car navigation touch panel, the pressure sensitive adhesive layer ( Since the interfacial peeling at the interface between C) and the polyester base film (E) can be suppressed, the reliability of the apparatus is improved.

[Heat resistant water adhesion improving layer (D)]
The heat resistant water adhesion improving layer (D) is a layer for preventing the pressure-sensitive adhesive layer (C) from peeling in the evaluation of the heat resistant water adhesion. The thickness of the heat resistant water adhesion improving layer (D) is preferably 0.01 to 0.5 μm. If the thickness of the heat resistant water adhesion improving layer (D) is 0.01 to 0.5 μm, good heat resistant water adhesion is exhibited, but it is preferable because the heat resistant water adhesion may not be ○ outside the above range. Absent. A more preferable thickness range is 0.03 to 0.4 μm, and 0.05 to 0.3 μm is even more preferable.

  Preferred as the heat resistant water adhesion improving layer (D) is a crosslinked polymer layer (crosslinked polymer layer), which is a layer obtained by crosslinking a polymer with a crosslinking agent, or a layer using a self-crosslinking type polymer. There is.

  The polymer that can be used in the method of crosslinking with a crosslinking agent is not particularly limited, but is preferably at least one selected from the group consisting of polyesters, polyurethanes, and acrylic polymers. The above polymers may be used alone or in combination of two or three different types.

[Polyester for heat resistant water adhesion improving layer (D)]
The polyester has an ester bond in the main chain or side chain, and is obtained by polycondensation of polyvalent carboxylic acid and glycol.

  As the polyvalent carboxylic acid component constituting the polyester, aromatic, aliphatic, and alicyclic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and ester derivatives thereof can be used.

  Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxy Ethane-p, p′-dicarboxylic acid, phenylindanedicarboxylic acid and the like can be used. From the viewpoint of strength and heat resistance of the heat resistant water adhesion improving layer (D), these aromatic dicarboxylic acids are preferably 30 mol% or more, more preferably 35 mol% or more in 100 mol% of the polyvalent carboxylic acid component, More preferably, it is preferable to use polyester occupying 40 mol%.

  Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

  Examples of the glycol component of polyester include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol Neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2, 4-trimethyl-1,6-hexanediol, 1,2-cyclo Xanthodimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidenephenol 4,4′-isopropylidenevindiol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used.

  In addition, when using polyester as an aqueous liquid as a coating liquid, a compound containing a carboxylic acid (salt) group or a compound containing a sulfonic acid (salt) group is used to facilitate water-solubilization or water-dispersion of the polyester. It is preferable to copolymerize a compound containing a phosphonic acid (salt) group.

  Examples of the compound containing a carboxylic acid (salt) group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1 , 2,3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydro Furfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellite 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, ethylenetetracarboxylic acid, etc., or alkali metal salts, alkaline earth metal salts thereof, An ammonium salt etc. can be mentioned.

  Examples of the compound containing a sulfonic acid (salt) group include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo-1,4-bis (hydroxyethoxy) benzene or the like, or an alkali metal salt, alkaline earth metal salt, or ammonium salt thereof can be used.

  Examples of the compound containing a phosphonic acid (salt) group include phosphoterephthalic acid, 5-phosphosophthalic acid, 4-phosphoisophthalic acid, 4-phosphonaphthalene-2,7-dicarboxylic acid, phospho-p-xylylene glycol, 2 -Phospho-1,4-bis (hydroxyethoxy) benzene or the like, or alkali metal salts, alkaline earth metal salts, and ammonium salts thereof can be used.

  In the present invention, for example, a modified polyester copolymer such as a block copolymer or a graft copolymer modified with acrylic, urethane, epoxy, or the like can be used as the polyester.

  Preferred polyesters include those selected from terephthalic acid, isophthalic acid, sebacic acid, 5-sodium sulfoisophthalic acid as the acid component, and ethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol as the glycol component. And the like. When water resistance is required, a copolymer or the like containing trimellitic acid as its copolymer component can be suitably used instead of 5-sodium sulfoisophthalic acid.

  The polyester can be produced by the following production method. For example, a polyester having a dicarboxylic acid component consisting of terephthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid and a glycol component consisting of ethylene glycol and neopentyl glycol can be directly esterified with these monomers. Or it can manufacture by the method etc. which manufacture by the 1st step which transesterifies, and the 2nd step which carries out the polycondensation reaction of the reaction product of this 1st step.

  At this time, for example, alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound, or the like can be used as the reaction catalyst.

  Further, as a method for obtaining a polyester having many carboxyl groups at the terminal and / or side chain, JP-A-54-46294, JP-A-60-209073, JP-A-62-240318, JP JP 53-26828, JP 53-26829, JP 53-98336, JP 56-116718, JP 61-124684, JP 62-240318 Although it can be produced by copolymerizing a trivalent or higher polyvalent carboxylic acid described in the gazette, etc., other methods may be used.

  Further, as the water-dispersed polyester resin, for example, a commercially available “Vaironal (registered trademark)” series (manufactured by Toyobo Co., Ltd.) can also be used.

  The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.3 dl / g or more in terms of adhesiveness, more preferably 0.35 dl / g or more, and most preferably 0.4 dl / g or more. It is. The glass transition temperature (hereinafter sometimes abbreviated as Tg) of the polyester is preferably 0 to 130 ° C, more preferably 10 to 85 ° C. When using a polyester having a Tg of 0 ° C. or higher, the heat resistant water adhesion is improved, and after the heat resistant water adhesion improving layer (D) is laminated on the surface of the polyester base film (E), one end of the film is wound. Such a blocking phenomenon can be suppressed. Moreover, stability and water dispersibility can be favorably maintained by using polyester with Tg of 130 ° C. or lower.

[Polyurethane for heat resistant water adhesion improving layer (D)]
Next, polyurethane will be described. The polyurethane is not particularly limited as long as it has a urethane bond, and the main component is obtained by polymerizing a polyol compound and a polyisocyanate compound.

  Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone. Polyhexamethylene adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, acrylic polyol and the like can be used.

  Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolethane, and the like. it can.

  In the synthesis of the polyurethane, a known chain extender, a crosslinking agent, and the like may be included in addition to the polyol compound and the polyisocyanate compound. As the chain extender or crosslinking agent, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine, or the like can be used.

  In order to obtain a stable polyurethane water dispersion, it is preferable to synthesize polyurethane having an increased affinity for water. Specifically, an appropriate amount of anionic groups may be introduced into the polyurethane. For example, a method of using a compound having an anionic group for polyol, polyisocyanate, chain extender, etc., a method of reacting an unreacted isocyanate group of the produced polyurethane with a compound having an anionic group, or having an active hydrogen of polyurethane It can be produced by a method of reacting a group with a specific compound.

  The anionic group in the polyurethane is preferably used as a sulfonic acid group, a carboxylic acid group, and an ammonium salt, lithium salt, sodium salt, potassium salt or magnesium salt thereof.

  The amount of the unit having an anionic group in the polyurethane is preferably 0.05% by mass to 15% by mass from the viewpoint of water dispersibility of the polyurethane.

  For example, as a polyurethane water dispersion, “Hydran (registered trademark)” series (manufactured by Dainippon Ink & Chemicals, Inc.) can be used.

[Acrylic polymer for heat resistant water adhesion improving layer (D)]
Examples of the monomer component constituting the acrylic polymer include, for example, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. Hydroxy group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate), 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.) ; (Meth) acrylamide N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-phenyl (meth) acrylamide, etc. Amino group-containing monomer such as N, N-diethylaminoethyl (meth) acrylate; epoxy group-containing monomer such as glycidyl (meth) acrylate; (meth) acrylic acid and salts thereof (lithium salt, sodium salt, A monomer containing a carboxyl group such as potassium salt or the like or a salt thereof can be used, and these are (co) polymerized using one kind or two or more kinds. Furthermore, these can be used in combination with other types of monomers.

  Examples of other types of monomers include epoxy group-containing monomers such as allyl glycidyl ether; sulfonic acids such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomer containing a group and a salt thereof; a monomer containing a carboxyl group or a salt thereof such as crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomers containing acid anhydrides such as maleic anhydride and itaconic anhydride; vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid monoe Ether, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, may be used vinyl chloride.

  Moreover, as said acrylic polymer, a modified acrylic polymer, for example, a block copolymer modified with polyester, polyurethane, epoxy resin, etc., a graft copolymer, etc. can be used.

  The lower limit of Tg of the acrylic polymer is preferably −10 ° C., more preferably 0 ° C., and most preferably 10 ° C. from the viewpoint of hot water adhesion and blocking resistance. On the other hand, the upper limit of Tg of the acrylic polymer is preferably 90 ° C., more preferably 50 ° C., and most preferably 40 ° C. from the viewpoints of heat resistant water adhesion and film-forming properties. Further, the weight average molecular weight (Mw) of the acrylic polymer is preferably 50,000 or more, and more preferably 300,000 or more from the viewpoint of heat resistant water adhesion.

  Preferable examples of the acrylic polymer include copolymers composed of monomers selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, and acrylic acid.

  It is preferable to dissolve, emulsify, or suspend an acrylic polymer in water and use it as an aqueous liquid from the viewpoint of environmental pollution and explosion-proof properties during coating. Such water-based acrylic polymers are copolymerized with monomers having a hydrophilic group (acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof, etc.) and emulsion polymerization using reactive emulsifiers and surfactants, It can be prepared by a method such as suspension polymerization or soap-free polymerization.

  Commercially available acrylic emulsions may also be used, for example, “Jonkrill (registered trademark)” series (manufactured by BASF Japan).

[Crosslinking agent used for heat resistant water adhesion improving layer (D)]
In the present invention, the polyester, polyurethane and acrylic polymer are preferably crosslinked. When the above polymer is cross-linked using a cross-linking agent, the cross-linking agent may be any one that can cross-link with a functional group present in the above-described polymer, such as a carboxyl group, a hydroxyl group, a methylol group, an amide group or the like. . For example, melamine crosslinking agent, oxazoline crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolated or alkylolized urea, acrylamide, polyamide resin, amide epoxy compound, various silanes A coupling agent, various titanate coupling agents, etc. can be used. In particular, a melamine-based crosslinking agent and an oxazoline-based crosslinking agent can be suitably used from the viewpoints of compatibility with the above-described polymer, heat resistant water adhesion, and the like.

  The melamine-based crosslinking agent is not particularly limited, but is a melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, or these A mixture of the above can be used. Moreover, as a melamine type crosslinking agent, a monomer, the condensate which consists of a multimer more than a dimer, these mixtures, etc. can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. Methylolated melamine resins such as methylated trimethylolmelamine and butylated hexamethylolmelamine are preferred. Furthermore, in order to accelerate | stimulate the thermosetting of a melamine type crosslinking agent, you may use acidic catalysts, such as p-toluenesulfonic acid.

  Further, the oxazoline-based crosslinking agent is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but includes at least one monomer containing an oxazoline group, and at least one kind of What consists of an oxazoline group containing copolymer obtained by copolymerizing another monomer is preferable.

  Monomers containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be used, and one or a mixture of two or more thereof can also be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

  In the oxazoline group-containing copolymer, the at least one other monomer used together with the oxazoline group-containing monomer is not particularly limited as long as it is a monomer copolymerizable with the oxazoline group-containing monomer. (Meth) acrylates or methacrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; non-acrylic acid, methacrylic acid, itaconic acid, maleic acid, etc. Saturated carboxylic acids; unsaturated nitriles such as (meth) acrylonitrile; unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether and ethyl Vinyl ethers such as nyl ether; olefins such as ethylene and propylene; halogen-containing α-β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated such as styrene and α-methylstyrene Saturated aromatic monomers etc. can be used and these can use 1 type, or 2 or more types of mixtures.

  As the oxazoline group-containing polymer, for example, “Epocross (registered trademark)” series (manufactured by Nippon Shokubai Co., Ltd.) is available.

  The isocyanate-based crosslinking agent is not particularly limited as long as it has an isocyanate group as a functional group in the compound, but it is preferable to use a polyfunctional isocyanate compound containing two or more isocyanate groups in one molecule. .

  As the polyfunctional isocyanate compound, a low-molecular or high-molecular aromatic or aliphatic diisocyanate or a trivalent or higher polyisocyanate can be used. Examples of the polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Furthermore, an excess amount of these isocyanate compounds and low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or polyester polyols, poly The terminal isocyanate group containing compound obtained by making it react with polymer active hydrogen compounds, such as ether polyols and polyamides, can be mentioned.

  In addition, when using an isocyanate compound as a crosslinking agent, it is also possible to use a block type isocyanate compound. The blocked isocyanate can be prepared by subjecting the above isocyanate compound and blocking agent to an addition reaction by a conventionally known appropriate method. Examples of the isocyanate blocking agent include phenols such as phenol, cresol, xylenol, resorcinol, nitrophenol and chlorophenol; thiophenols such as thiophenol and methylthiophenol; oximes such as acetoxime, methyl etiketooxime and cyclohexanone oxime. Alcohols such as methanol, ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol ; Lactams such as ε-caprolactam, δ-valerolactam, ν-butyrolactam, β-propyllactam; aromatic amines; imides; acetylacetone, acetoacetate, ethyl malonate Active methylene compounds such as esters, mercaptans, imines; ureas; diaryl compounds; sodium bisulfite, and the like.

  The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group as a functional group in the compound. However, it is preferable to use a polyfunctional epoxy compound having two or more epoxy groups in one molecule. .

  Examples of the polyfunctional epoxy compound include diglycidyl ether of bisphenol A and oligomer thereof, diglycidyl ether of hydrogenated bisphenol A and oligomer thereof, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and Polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl Examples include ether, triglycidyl ether of glycerol alkylene oxide adduct, and the like.

  As the cross-linking agent, a phenol formaldehyde resin of a condensate with formaldehyde such as alkylated phenols and cresols; an adduct of urea, melamine, benzoguanamine and the like with formaldehyde, this adduct and an alcohol having 1 to 6 carbon atoms An amino resin such as an alkyl ether compound consisting of can also be used.

  Examples of the phenol formaldehyde resin include alkylated (methyl, ethyl, propyl, isopropyl or butyl) phenol, p-tert-amylphenol, 4,4′-sec-butylidenephenol, p-tert-butylphenol, o-, m-, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol, xylenol, etc. And the condensates of phenols and formaldehyde.

  Examples of amino resins include methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like. Are preferably methoxylated methylol melamine, butoxylated methylol melamine, methylolated benzoguanamine, and the like.

  The polymer (polyester, polyurethane, acrylic polymer) and the crosslinking agent can be mixed and used in an arbitrary ratio. However, in order to express the hot water adhesive effect of the present invention more remarkably, the crosslinking agent is: The addition of 2 to 50 parts by mass with respect to 100 parts by mass of the polymer is preferred, more preferably 3 to 25 parts by mass. When the addition amount of the crosslinking agent is less than 2 parts by mass, the effect of addition is small, and when it exceeds 50 parts by mass, the hot water resistant adhesiveness tends to be lowered.

[Self-crosslinking polymer of heat resistant water adhesion improving layer (D)]
In the present invention, in addition to the above method, for example, the heat resistant water adhesion improving layer (D) may be formed using a self-crosslinking type polymer in which a crosslinkable functional group is introduced into the above-described polymer. In the case of using a self-crosslinking type polymer, the crosslinking method may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as ultraviolet rays, electron beams and γ rays.

  Hereinafter, a specific method will be illustrated for the case of polyester as the self-crosslinking polymer.

  The self-crosslinking type polyester preferably used in the present invention is a polyester graft copolymer obtained by grafting a hydrophobic copolymer polyester with a compound having at least one radical polymerizable double bond. The “grafting” of the polyester-based graft copolymer in the present invention is to introduce a branched polymer made of a polymer different from the main chain into the backbone polymer which is the main chain. Graft polymerization is usually carried out by reacting at least one radically polymerizable monomer using a radical initiator in a state where a hydrophobic copolyester is dissolved in an organic solvent. Hydrophobic copolyesters are essentially water-insoluble polyesters that do not inherently dissolve in water, so they are more heat resistant than using polyester resins that are soluble in water as the backbone polymer for graft polymerization. Excellent water adhesion.

  The hydrophobic copolyester is composed of 60 to 99.5 mol% of aromatic dicarboxylic acid, 0 to 39.5 mol% of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid in 100 mol% of dicarboxylic acid component, radical It is preferable that the dicarboxylic acid containing a polymerizable double bond is 0.5 to 10 mol%. More preferably, the aromatic dicarboxylic acid is 68 to 98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0 to 30 mol%, and the dicarboxylic acid containing a polymerizable unsaturated double bond is 2 to 7 Mol%.

  When the aromatic dicarboxylic acid is 60 mol% or more and the aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid is 39.5 mol% or less, the heat resistant water adhesion is good. Moreover, the grafting of the radically polymerizable monomer with respect to the polyester resin can be efficiently performed by using 0.5 mol% or more of the dicarboxylic acid containing a radically polymerizable double bond. On the other hand, the content of 10 mol% or less is preferable because the viscosity of the reaction solution can be prevented from significantly increasing in the later stage of the grafting reaction, and the reaction can proceed uniformly.

  As the aromatic dicarboxylic acid, aliphatic and / or alicyclic dicarboxylic acid, any of the compounds exemplified above can be used. Examples of the dicarboxylic acid containing a radically polymerizable double bond include fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and other α, β-unsaturated dicarboxylic acids; 2,5-norbornene dicarboxylic acid anhydride And alicyclic dicarboxylic acids containing unsaturated double bonds such as tetrahydrophthalic anhydride. Of these dicarboxylic acids containing a polymerizable unsaturated double bond, fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid are preferred from the viewpoint of polymerizability.

  As the glycol component, any of the compounds exemplified above can be used. Two or more glycol components may be used in combination. Especially, C2-C10 aliphatic glycol, C6-C12 alicyclic glycol, etc. are preferable.

  The hydrophobic copolymerized polyester may be copolymerized with 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol. The tri- or higher functional polycarboxylic acid includes (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenone tetracarboxylic acid, trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (an Hydrotrimellitate) and the like. As the trifunctional or higher functional polyol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, or the like is used.

  The tri- or higher functional polycarboxylic acid and / or polyol is copolymerized in the range of 0 to 5 mol%, preferably 0 to 3 mol%, based on the total acid component or the total glycol component. Gelation can be suppressed.

  In addition, the lower limit of the weight average molecular weight of the hydrophobic copolyester is preferably 5,000 from the viewpoint of heat resistant water adhesion. Moreover, it is preferable that an upper limit is 50,000 at points, such as gelatinization at the time of superposition | polymerization.

  After the hydrophobic copolyester is synthesized, graft polymerization is performed. Graft polymerization is performed by reacting at least one radical polymerizable monomer using a radical initiator in a state where the hydrophobic copolyester is dissolved in an organic solvent. The reaction product after completion of the grafting reaction is not limited to the graft copolymer of the desired hydrophobic copolymerized polyester and the radically polymerizable monomer, but also the hydrophobic copolymerized polyester and the hydrophobic copolymer that were not subjected to grafting. It also contains a (co) polymer obtained from a radically polymerizable monomer that has not been grafted to the polyester. The polyester-based graft copolymer in the present invention includes not only the above-described polyester-based graft copolymer, but also a hydrophobic copolymerized polyester that has not been grafted, and a radically polymerizable monomer that has not been grafted. Also included are reaction mixtures containing the resulting (co) polymer and monomer (residual monomer).

In the present invention, the acid value of a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolymerized polyester is preferably 600 eq / 10 ⁶ g or more from the viewpoint of heat resistant water adhesion. More preferably, the acid value of the reactant is 1200 eq / 10 ⁶ g or more. When the acid value of the reaction product is less than 600 eq / 10 ⁶ g, the hot water adhesion may be lowered.

  The mass ratio of the desired hydrophobic copolymerized polyester and the radical polymerizable monomer suitable for the purpose of the present invention is preferably in the range of polyester / radical polymerizable monomer = 40/60 to 95/5, more preferably 55/45. ~ 93/7, most desirably in the range of 60/40 to 90/10.

  By setting the mass ratio of the hydrophobic copolyester to 40% by mass or more, the excellent adhesiveness of the polyester can be exhibited. On the other hand, when the mass ratio of the hydrophobic copolymerized polyester is 95% by mass or less, the blocking resistance can be improved and the acid value of the reaction product can be adjusted to the above range.

  The graft polymerization reaction product is in the form of an organic solvent solution or dispersion or an aqueous solvent solution or dispersion. In particular, a dispersion of an aqueous solvent, that is, a form of an aqueous dispersion is preferable in terms of working environment and applicability. Therefore, as the radical polymerizable monomer to be grafted, it is preferable to use a radical polymerizable monomer that essentially contains a hydrophilic radical polymerizable monomer. And after carrying out the graft polymerization in an organic solvent, the aqueous dispersion can be obtained by distilling off the organic solvent and adding water.

  The hydrophilic radical polymerizable monomer means a radical polymerizable monomer having a hydrophilic group or a group that can be changed to a hydrophilic group later. Examples of the radical polymerizable monomer having a hydrophilic group include a radical polymerizable monomer containing a carboxyl group, hydroxyl group, phosphoric acid group, phosphorous acid group, sulfonic acid group, amide group, quaternary ammonium base and the like. . On the other hand, examples of the radical polymerizable monomer having a group that can be changed into a hydrophilic group include radical polymerizable monomers containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among these, from the viewpoint of water dispersibility, a carboxyl group is preferable, and a radical polymerizable monomer having a carboxyl group or a group capable of generating a carboxyl group is preferable.

  In order to make the acid value of the graft reaction product within the above preferred range, it is preferable that a radical polymerizable monomer containing a carboxyl group or having a group capable of generating a carboxyl group is contained. Such monomers include fumaric acid, monoethyl fumarate; maleic acid and its anhydride, monoethyl maleate; itaconic acid and its anhydride, monoester of itaconic acid; acrylic acid, methacrylic acid; and salts thereof (sodium Salt, potassium salt, ammonium salt) and the like. Maleic anhydride is preferable. The said monomer can be copolymerized using 1 type, or 2 or more types.

  The radically polymerizable monomer to be grafted may contain other types of monomers as long as the acid value is within the above-mentioned preferable range. As other types of monomers, monomers that can be used when synthesizing the acrylic polymer described above can be used as they are.

  Examples of the graft polymerization initiator used in the present invention include organic peroxides and organic azo compounds known to those skilled in the art. Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxypivalate, and examples of the organic azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2, 4-dimethyl pareronitrile). The amount of the polymerization initiator used for the graft polymerization is at least 0.2% by mass, preferably 0.5% by mass or more, based on the radical polymerizable monomer.

  In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branched polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole may be used as necessary. In this case, it is desirable to add in the range of 0 to 5% by mass with respect to the polymerizable monomer.

  The grafting reaction product is preferably neutralized with a basic compound, and can be easily dispersed in water by neutralization. As the basic compound, a compound that volatilizes at the time of coating film formation is desirable, and ammonia, organic amines, and the like are preferable. Desirable compounds include, for example, triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine , 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanol An amine etc. can be mentioned.

  The basic compound has a pH value of the aqueous dispersion in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization, depending on the carboxyl group content contained in the grafting reaction product. It is desirable to use it. If a basic compound with a boiling point of 100 ° C. or less is used, there are few residual basic compounds in the coating film after drying, and for example, improved hot water adhesion in harsh environments such as high temperature and humidity To do.

  In the grafting reaction product, the weight average molecular weight of the polymer of the radical polymerizable monomer is preferably 500 to 50,000. It is generally difficult to control the weight average molecular weight of the polymer of the radical polymerizable monomer to be less than 500, the graft efficiency is lowered, and there is a tendency that hydrophilic groups are not sufficiently imparted to the copolymer polyester. In addition, the graft polymer of the radical polymerizable monomer forms a hydrated layer of dispersed particles. To obtain a stable aqueous dispersion with a sufficient thickness of the hydrated layer, the graft polymer of the radical polymerizable monomer is used. The weight average molecular weight of is desirably 500 or more.

  The upper limit of the weight average molecular weight of the graft polymer of the radical polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization. In order to make the weight average molecular weight of the graft polymer of the radical polymerizable monomer within the range of 500 to 50,000, the initiator amount, the monomer dropping time, the polymerization time, the reaction solvent, the monomer composition, or the chain as necessary. It is preferable to carry out by appropriately combining a transfer agent and a polymerization inhibitor.

  The glass transition temperature of the graft copolymer is not particularly limited, but it is preferably 20 ° C. or higher, more preferably 40 ° C. or higher in consideration of heat resistant water adhesion.

  In the present invention, a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolymerized polyester has a self-crosslinking property because a hydroxyl group in the polyester and a carboxyl group present in the graft portion react. Moreover, although it does not bridge | crosslink at normal temperature, it carries out intermolecular reaction, such as a hydrogen abstraction reaction by a thermal radical, with the heat at the time of drying at the time of coating-film formation, and bridge | crosslinks without a crosslinking agent. As a result, a high degree of heat-resistant water adhesion is exhibited. The degree of crosslinking of the coating film can be evaluated by various methods, and examples thereof include a method of measuring the insoluble fraction in a chloroform solvent or the like that dissolves both the hydrophobic copolymerized polyester and the grafted polymer.

  The insoluble fraction of the coating film obtained by drying at about 80 ° C. and heat-treating at 120 ° C. for 5 minutes is preferably 50% by mass or more, more preferably 70% by mass from the viewpoints of heat resistant water adhesion and blocking resistance. That's it.

  As the self-crosslinking polyester resin aqueous dispersion, for example, a commercially available product such as “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.) can be used.

  In addition, a grafted polyurethane can be prepared by a method similar to the above.

[Additive for heat resistant water adhesion improving layer (D)]
Various additives such as antioxidants, heat stabilizers, weathering stabilizers, ultraviolet absorbers, and organic additives can be added to the heat resistant water adhesion improving layer (D) as long as the effects of the present invention are not impaired. A lubricant, a pigment, a dye, organic or inorganic fine particles, a filler, an antistatic agent, a nucleating agent, and the like may be blended.

  In particular, in the case where inorganic particles are added to the heat resistant water adhesion improving layer (D), for example, the heat resistant water adhesion improving layer (D) is laminated on the surface of the polyester base film (E), and one end winding is performed. Since slipperiness and blocking resistance, such as when taking, improve, it is preferable. In this case, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, or the like can be used as the inorganic particles to be added. The average particle size used is preferably 0.005 to 5 μm, more preferably 0.01 to 3 μm, and most preferably 0.05 to 2 μm. Although the usage-amount of an inorganic particle is not specifically limited, It is preferable to mix 0.05-10 mass parts by solid content with respect to 100 mass parts of polymers in a heat-resistant water adhesive improvement layer (D), More preferably, it is 0.8. 1 to 5 parts by mass.

[Method of forming heat resistant water adhesion improving layer (D)]
The heat resistant water adhesion improving layer (D) is an aqueous dispersion of a mixture of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent, or water of a self-crosslinking polymer. Since it is formed from a dispersion, it is the easiest to form by a coating method, and it may be applied to the surface of the polyester base film (E). Suitable is a method of applying to an unstretched film of the polyester base film (E) and then stretching in at least one direction, a method of applying after longitudinal stretching, a method of applying to the film surface after the orientation treatment, etc. A method is also possible. In particular, when the polyester base film (E) is produced, it is applied before the completion of the crystal orientation of the film, and then stretched in at least one direction, and then the so-called in-line coating that completes the crystal orientation of the polyester film. Since the method can easily form a thin film, the effect of the present invention can be exhibited more significantly, which is preferable.

  You may provide a heat-resistant water adhesive improvement layer (D) on both surfaces of a polyester-type base film (E).

  For example, when the coating liquid is applied to an unstretched film of the polyester base film (E), various coating methods such as reverse coating method, gravure coating method, rod coating method, bar coating method, Meyer bar A coating method, a die coating method, a spray coating method, or the like can be used.

[Acrylic adhesive layer (F)]
The other pressure-sensitive adhesive layer in the double-sided pressure-sensitive adhesive sheet of the present invention is an acrylic pressure-sensitive adhesive layer (F). The pressure-sensitive adhesive constituting the acrylic pressure-sensitive adhesive layer (F) contains, for example, an acrylic polymer having a main monomer component of (meth) acrylate having an alkyl group having 1 to 18 carbon atoms as a main component or base polymer. An acrylic pressure-sensitive adhesive is used.

  Examples of the (meth) acrylate having an alkyl group having 1 to 18 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) Examples include acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl acrylate (meth) acrylate, decyl acrylate (meth) acrylate, and dodecyl (meth) acrylate. These (meth) acrylates can be used alone or in admixture of two or more.

  Moreover, the monomer component (copolymerizable monomer) which has a copolymerizability with the said (meth) acrylate may be used. In particular, when the acrylic polymer is cross-linked, the copolymerizable monomer is preferably a monomer for modifying the acrylic pressure-sensitive adhesive, and any known monomer for modifying can be used. The copolymerizable monomers can be used alone or in combination of two or more.

  Specifically, as the copolymerizable monomer, any of the monomer components constituting the acrylic polymer for the heat resistant water adhesion improving layer (D) and the monomers exemplified as other types of monomers can be used. Furthermore, ethylene, Examples include α-olefin monomers such as propylene.

  As the modifying monomer, the functional group-containing monomer is preferable, and among these, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferable, and acrylic acid is particularly preferable. The acrylic polymer can be crosslinked using a functional group (particularly a polar group) derived from the modifying monomer.

  Polymerization methods for obtaining acrylic polymers include solution polymerization methods using emulsion initiators such as azo compounds and peroxides, emulsion polymerization methods and bulk polymerization methods, and light and radiation using photoinitiators. A polymerization method performed by irradiation can be employed. In the present invention, a method of polymerizing using a polymerization initiator that decomposes to generate radicals (radical polymerization method) can be suitably employed. In this radical polymerization, polymerization initiators such as peroxides such as benzoyl peroxide and tert-butyl permaleate, and azo compounds such as 2,2′-azobisisobutyronitrile and azobisisovaleronitrile are usually used. To do. The amount of the polymerization initiator used may be an amount usually used in the polymerization of the acrylic monomer, and for example, about 0.005 to 10 parts by mass, preferably 0.1 to 100 parts by mass of the total amount of monomer components. About 5 parts by mass.

  The ratio of the (meth) acrylate having an alkyl group having 1 to 18 carbon atoms as the main monomer component of the acrylic polymer is 50% by mass or more with respect to 100% by mass of the monomer component from the viewpoint of adhesive properties. preferable. 80 mass% or more is more preferable, and 90 mass% or more is further more preferable. Therefore, the proportion of the copolymerizable monomer other than the (meth) acrylate is 50% by mass or less in 100% by mass of the monomer component.

  The acrylic polymer obtained by polymerizing the monomer component can be used as it is. It is also possible to cure the acrylic polymer by crosslinking. When the polymer is crosslinked, the cohesive force of the pressure-sensitive adhesive can be further increased. For crosslinking, a crosslinking agent can be used. That is, the acrylic pressure-sensitive adhesive may contain a crosslinking agent together with the acrylic polymer. For the crosslinking of the polymer, a heat crosslinking method is preferably used.

  As the crosslinking agent, any of the crosslinking agents exemplified as the crosslinking agent that can be used in the heat resistant water adhesion improving layer (D) can be used. As the crosslinking agent, melamine crosslinking agent, epoxy crosslinking agent, and isocyanate crosslinking agent are particularly preferable. A crosslinking agent can be used individually or in mixture of 2 or more types. 0.001-10 mass parts is preferable with respect to 100 mass parts of acrylic polymers, and, as for the usage-amount of a melamine type crosslinking agent and / or an epoxy-type crosslinking agent, 0.01-5 mass parts is more preferable. 0.01-20 mass parts is preferable with respect to 100 mass parts of acrylic polymers, and, as for the usage-amount of an isocyanate type crosslinking agent, 0.05-15 mass parts is more preferable.

  You may add various additives to an acrylic adhesive as needed. For example, a tackifier resin (for example, a rosin resin, a terpene resin, a petroleum resin, a coumarone / indene resin, a styrene resin, or the like) may be blended to adjust the adhesion characteristics. From the viewpoint of increasing the colorless transparency of the double-sided pressure-sensitive adhesive sheet and suppressing the change in color tone, a hydrogenated tackifying resin is preferable, and the blending ratio is preferably set in a range that does not increase the haze of the double-sided pressure-sensitive adhesive sheet. Further, as additives other than the tackifying resin, various known additives such as plasticizers, fillers such as fine powder silica, colorants, ultraviolet absorbers, surfactants and the like can be blended. The amount of these additives used may be a normal amount applied to the acrylic pressure-sensitive adhesive.

  The adhesive force of the acrylic pressure-sensitive adhesive layer (F) can be controlled by a method such as a modification monomer (functional group-containing copolymerizable monomer), a ratio adjustment of a crosslinking agent, or a method using a surfactant. The thickness in particular of an acrylic adhesive layer (F) is not restrict | limited, For example, 3-200 micrometers is preferable. 5-50 micrometers is more preferable and 10-30 micrometers is further more preferable.

  In addition, as the acrylic pressure-sensitive adhesive, for example, “SK Dyne” series manufactured by Soken Chemical Co., Ltd. can be used. Among these, use of a brand of optical pressure-sensitive adhesive is preferable.

  The formation method of the said acrylic adhesive layer (F) is not limited. For example, a solution type coating solution of an organic solvent or a coating solution in the form of an aqueous dispersion is prepared and applied by a coating method. In addition, a layer having the same composition as the heat resistant water adhesion improving layer (D) is provided between the acrylic pressure-sensitive adhesive layer (F) and the polyester base film (E), and the acrylic pressure-sensitive adhesive layer (F). You may comprise so that adhesiveness with a base film (E) may be improved.

  The adhesive strength of the acrylic pressure-sensitive adhesive layer (F) may be the same as that of the adhesive layer (C), or may be small or large. It is preferable to select and set appropriately depending on the method of using the double-sided pressure-sensitive adhesive tape of the present invention. For example, in order to apply to a usage method that requires re-peelability on both sides, the adhesive layer (C) has the same adhesive strength as that of the adhesive layer (C), that is, 0.01 to 1.0 N / 20 mm (relative to 180 ° glass). The range of the test and the pulling speed of 300 mm / min is preferable. On the other hand, when firmly fixing one side, it is good to set it higher than the said range. For example, the adhesive strength when used for bonding the touch panel portion and the display device portion of the touch panel is preferably 5.0 N / 20 mm or more, for example, 5.0 to 25 N / 20 mm is a suitable range. . A more preferable range is 8.0 to 20 N / 20 mm.

[Separate film (G)]
The separation film (G) laminated on the surface of the acrylic pressure-sensitive adhesive layer (F) is not particularly limited as long as the peelability from the pressure-sensitive adhesive layer (F) is good, and a mold release made of a silicone compound or a fluorine-based compound. It is a preferable embodiment to use a commercially available release polyester film in which layers are laminated.

  The peel strength between the separate film (G) and the adhesive layer (F) is preferably 0.03 to 1.0 N / 20 mm. If it is 0.03 N / 20 mm or more, when the double-sided pressure-sensitive adhesive sheet is wound up in the production process of the double-sided pressure-sensitive adhesive sheet of the present invention, the separation film (G) can be prevented from being lifted. An adhesive sheet can be manufactured. On the other hand, when the peel strength is 1.0 N / 20 mm or less, the peelability between the separate film (G) and the adhesive layer (F) is improved.

[Optical characteristics of double-sided PSA sheet]
The double-sided pressure-sensitive adhesive sheet of the present invention preferably has a total light transmittance of 91% or more and a haze of 1.2% or less in applications requiring high transmittance. More preferably, the total light transmittance is 92% or more and the haze is 1.1% or less. Furthermore, it is preferable that the total light transmittance and haze are within the above-mentioned preferable range even after storage at 65 ° C. and 85 RH% for 200 hours.

  Although the double-sided pressure-sensitive adhesive sheet of the present invention has the above-mentioned properties, it can be suitably used for bonding optical members, but is not limited to this application.

[Method for producing double-sided PSA sheet]
The double-sided PSA sheet is preferably produced by any of the methods shown below. This is because the above-described characteristics can be stably expressed and the economy is excellent. In each production method, each process is basically performed in the order described. A step not described may be performed between a certain step and the next step.

  The first method is as follows.

A step of laminating the heat resistant water adhesion improving layer (D) on one side of the polyester base film (E) to form a laminate (1);
A step of forming a laminate (2) by laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the heat resistant water adhesion improving layer (D) of the laminate (1);
A step of laminating the release layer (B) on one side of the polyester film (A) to form a laminate (3);
The laminates (2) and (3) are formed so that the release layer (B) of the laminate (3) is in contact with the surface of the layer (2) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton. ) To form a laminate (4),
A step of crosslinking a non-crosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (4) to form a laminate (4 ′) having an adhesive layer (C);
On the surface of the polyester base film (E) of the laminate (4 ′), with or without another heat resistant water adhesion improving layer (D), an acrylic pressure-sensitive adhesive layer (F) and a separate film ( G) are laminated in this order,
It is a manufacturing method containing.

  The second method is as follows.

A step of laminating an acrylic pressure-sensitive adhesive layer (F) on one side of a separate film (G) to form a laminate (5);
Each step of forming the laminate (1), laminate (2), laminate (3), laminate (4) and laminate (4 ′),
The polyester-based substrate film (E) of the laminate (4 ′) is laminated with or without the laminate (4 ′) and laminate (5) with or without another heat resistant water adhesion improving layer (D). A step of laminating so as to be on the acrylic adhesive layer (F) side of the body (5),
It is a manufacturing method containing.

  The third method is as follows.

Forming the laminate (3);
A step of laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the release layer (B) of the laminate (3) to form a laminate (6);
Forming the laminate (1);
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4) according to claim 7,
Forming the laminate (4 ′);
On the surface of the polyester base film (E) of the laminate (4 ′), with or without another heat resistant water adhesion improving layer (D), an acrylic pressure-sensitive adhesive layer (F) and a separate film ( G) are laminated in this order,
It is a manufacturing method containing.

  The fourth method is as follows.

Forming the laminate (5);
Forming the laminate (3);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4),
Forming the laminate (4 ′);
The polyester-based substrate film (E) of the laminate (4 ′) is laminated with or without the laminate (4 ′) and laminate (5) with or without another heat resistant water adhesion improving layer (D). A step of laminating so as to be on the acrylic adhesive layer (F) side of the body (5),
It is a manufacturing method containing.

  The fifth method is as follows.

Each step of forming the laminate (1), laminate (2), laminate (3) and laminate (4),
An acrylic pressure-sensitive adhesive layer (F) and a separate film (G) may be formed on the surface of the polyester base film (E) of the laminate (4) with or without another heat resistant water adhesion improving layer (D). ) In this order to form a laminate (7),
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
It is a manufacturing method containing.

  The sixth method is as follows.

Forming the laminate (5);
Each step of forming the laminate (1), laminate (2), laminate (3) and laminate (4),
The laminated body (4) and the laminated body (5) are passed through the laminated body (4) with the polyester-based substrate film (E) through the laminated body (4) with or without another hot water resistant adhesion improving layer (D). 5) the step of laminating the acrylic pressure-sensitive adhesive layer (F) side to form the laminate (7);
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
It is a manufacturing method containing.

  The seventh method is as follows.

Forming the laminate (3);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4),
Forming the laminate (7);
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
It is a manufacturing method containing.

  The eighth method is as follows.

Forming the laminate (5);
Forming the laminate (3);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4),
The laminated body (4) and the laminated body (5) are passed through the laminated body (4) with the polyester-based substrate film (E) through the laminated body (4) with or without another hot water resistant adhesion improving layer (D). 5) the step of laminating the acrylic pressure-sensitive adhesive layer (F) side to form the laminate (7);
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
It is a manufacturing method containing.

  The ninth method is as follows.

Each step of forming the laminate (1), laminate (2), laminate (3), laminate (4), laminate (4 ′),
Forming the laminate (5);
A step of laminating another separate film (G ′) on the surface of the acrylic pressure-sensitive adhesive layer (F) of the laminate (5) to form a laminate (8);
While peeling off the separate film (G) or the separate film (G ′) of the laminate (8), the acrylic pressure-sensitive adhesive layer (F) is formed on the surface of the polyester base film (E) of the laminate (4 ′). Laminating so that the
It is a manufacturing method containing.

  The tenth method is as follows.

Forming the laminate (3);
Forming the laminate (6);
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4),
Forming the laminate (4 ′);
Forming the laminate (8);
While peeling off the separate film (G) or the separate film (G ′) of the laminate (8), the acrylic pressure-sensitive adhesive layer (F) is formed on the surface of the polyester base film (E) of the laminate (4 ′). Laminating so that the
It is a manufacturing method containing.

  Any of the first to tenth methods described above may be employed, and the manufacturing method may be different from these methods.

[How to use double-sided PSA sheet]
In the present invention, the double-sided pressure-sensitive adhesive sheet of the present invention is used for adhering an overlay sheet and a coordinate detection sheet of a capacitive touch panel, and a resistance film-type touch panel The use method of the double-sided adhesive sheet characterized by using for sticking of a touchscreen and a display apparatus is included. An overlay sheet that is a face sheet of a capacitive touch panel is a sheet that is touched by a finger on the touch panel, and a coordinate detection sheet is a sheet that detects a touched position coordinate. The touch panel of the resistive touch panel is a part touched by a finger or a pen, and the display device is a device that displays an image to be touched.

  The double-sided pressure-sensitive adhesive sheet of the present invention is not limited to use in the above-described region, and may be used for attaching other members in the touch panel assembly process. In addition to the touch panel, the double-sided pressure-sensitive adhesive sheet of the present invention can be applied to assembling applications for various display devices, bonding applications for optical members, bonding applications for members other than optical members, and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention. The measurement / evaluation methods employed in the examples are as follows. In the examples, “parts” means “parts by mass”, and “%” means “% by mass” unless otherwise specified.

1. Peel strength First, for a double-sided pressure-sensitive adhesive sheet having a length of about 200 mm and a width of 20 mm, the surface (two surfaces) whose peel strength is to be measured is exposed, and the double-sided pressure-sensitive adhesive sheet is a laminate including one surface and a laminate including the other surface. And set each on the chuck of the tensile tester. That is, for example, when measuring the peel strength at the interface between the release layer (B) and the pressure-sensitive adhesive layer (C), the double-sided pressure-sensitive adhesive sheet is slightly peeled off at the interface between the release layer (B) and the pressure-sensitive adhesive layer (C), Each of the release layer (B) and the adhesive layer (C) is exposed. In this case, the separate film (AB) composed of the polyester film (A) and the release layer (B) is held by one chuck, and the adhesive layer (C) to the separate film (G) are held by one chuck. Hold the laminate. And T-type peeling strength was measured by the method as described in JIS K6854-3. The tensile tester used was a trade name “Autograph” (manufactured by Shimadzu Corporation), and a T-type peel test was performed under conditions of a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film was lifted with a bar so that the T-shape was maintained. The maximum strength at the time of T-type peeling was defined as the peeling strength. When the release layer (B) and the adhesive layer (C) did not peel, it was not measured as difficult to peel. In this case, it indicates that the release layer (B) does not function as a release layer.

  The peel strength was also measured for the adhesive layer (C). Since the adhesive layer (C) and the polyester base film (E) are firmly bonded via the heat resistant water adhesion improving layer (D), when evaluating the peel strength of the adhesive layer (C), A cutter knife was inserted between the polyester base film (E) and peeled off (applied to the interface) by applying force with a finger. The case where the peel strength was strong and the interface could not be evaluated was evaluated as ◯, and the case where the interface could be aligned was evaluated as ×.

2. Resistant to hot water The double-sided PSA sheet is cut into 50 mm x 50 mm and separated into a separate film (hereinafter referred to as a separate film (G)) made of a polyester film (A) and a release layer (B). AB)) is peeled off. The sample is submerged in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water so that the adhesive layer (C) is on the lower side, and the entire sample is immersed in water. Put the lid on. In the case where the sample is not immersed in water by its own weight, for example, a polyester film having a size of 60 mm × 60 mm and a thickness of 188 μm may be placed on the sample and weighted. The size and material of the weight are not particularly limited, and the entire sample may be immersed in water. The container containing the sample is placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After the heat treatment, the container is taken out from the oven, and the sample is quickly taken out and rubbed 10 times by applying force with the finger pad from the adhesive layer (C) side to the end, and the adhesive layer (C) is a polyester base film (E ) Side, it was evaluated whether it peeled from the side. The case where the pressure-sensitive adhesive layer (C) was not peeled was marked with ◯, and the case where the pressure-sensitive adhesive layer (C) was peeled was marked with x.

3. Adhesive strength The adhesive strength of the adhesive layer (C) to the glass was measured by a 180-degree peeling method according to JIS Z0237. As the glass, heat resistant glass having a thickness of 3 mm and a width of 30 mm was used. The sample had a width of 20 mm, and was attached to the glass by reciprocating twice at a speed of about 29 mm / second using a 2 kg roller. The tensile speed was 300 mm / min, a tensile test was performed in an atmosphere at 23 ° C., and the maximum tensile strength was the adhesive strength (N / 20 mm).

4). Total light transmittance and haze The total light transmittance was measured according to JIS K7361-1, and the haze was measured according to JIS K7136 using a Nippon Denshoku Industries Co., Ltd. haze measuring instrument “NDH-2000”.

5). Clarity of the coating solution 100cc of the coating solution for forming the adhesive layer (C) is filtered through a wire mesh of 200mm (wire diameter 0.04mm) of 40mmφ, and the presence or absence of insoluble matter is confirmed with the naked eye. The case was marked with ○ and the case with insoluble matter was marked with ×.

6). Solution stability of the coating solution The coating solution for forming the adhesive layer (C) was evaluated by the change in viscosity of the solution when stored in a sealed state at room temperature (23 ° C) for 90 days to determine solution stability. The case where the change in viscosity of the solution was within ± 20% was marked as ◯, and the case where the change in viscosity of the solution exceeded ± 20% was marked as x. The viscosity was measured with a B-type viscometer.

Example 1
(1) Preparation of coating solution for forming heat resistant water adhesion improving layer (D) [Preparation of water dispersible copolyester resin]
A copolyester was synthesized in a batchwise manner using one pressure esterification reaction vessel with a distillation column and two polycondensation reaction vessels with a vacuum generator.

  First, 229 kg of terephthalic acid, 222 kg of isophthalic acid, 191 kg of 5-sodiumsulfoisophthalic acid di (hydroxyethyl) ester (ethylene glycol solution containing 34%) and 213 kg of neopentyl glycol melted at 140 ° C. in a nitrogen atmosphere in an esterification reaction tank Furthermore, 87 kg of a mixed solution of ethylene glycol and neopentyl glycol (mass ratio 45:55) recovered and refined (mass ratio 45:55) and 39 kg of an antimony trioxide ethylene glycol solution (antimony trioxide concentration 1.3%) were added while stirring. (0.05 mol% as antimony trioxide with respect to the acid component) and then pressurizing with nitrogen, raising the temperature of the reaction vessel with a heat medium and controlling the tower top temperature to 150 ° C, glycol in the reaction vessel 235 ° C. under a pressure of 0.3 MPa (gauge pressure) It performed 130 minutes esterification reaction to obtain an oligomer of copolyester.

  Next, the oligomer was transferred to the first polycondensation reaction tank, and while stirring, the pressure was reduced to 40 kPa at a pressure reduction rate of 5 kPa / min, and then to 0.3 kPa at a pressure reduction rate of 0.8 kPa / min, and initial condensation was carried out at 255 ° C. for 160 minutes. And a prepolymer of copolyester was obtained. Thereafter, the prepolymer was transferred to a second polycondensation reaction tank in which a spiral stirring blade was rotated under a vacuum of 0.13 kPa, and subjected to late condensation at a temperature of 265 ° C. for 120 minutes to obtain a reduced viscosity of 0.41. It was set as the copolymer ester polymer of this. Nitrogen was introduced into the second polycondensation reaction tank, and the copolymerized ester polymer was taken out as a 7 mm thick sheet with a gear pump, and crushed with a sheet cutter while cooling with water to obtain a crushed copolymerized polyester.

[Preparation of coating solution]
100 parts of the crushed material was dispersed in water by a conventional method. With respect to 100 parts of the solid content of this aqueous dispersion, 5 parts of methylol melamine resin “Cymel (registered trademark) 303” (manufactured by Mitsui Cytec Co., Ltd.) is used as the catalyst, and “Catalyst 600” (Mitsui Cytec Co., Ltd.) as the catalyst. Product) was added and stirred well to obtain a coating solution (D-1).

(2) Manufacture of polyester base film (E) and lamination of heat resistant water adhesion improving layer (D) Amorphous silica (Silycia; manufactured by Fuji Silysia) having an average particle diameter (SEM method) of 1.5 μm is 0. 0.04% polyethylene terephthalate pellets (intrinsic viscosity 0.65 dl / g) pellets were sufficiently dried in vacuum, then supplied to an extruder heated to 280 ° C., extruded into a sheet from a T-shaped die, and electrostatically applied Using a casting method, it was wound around a mirror casting drum having a surface temperature of 30 ° C. and cooled and solidified. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. Both surfaces of this film were subjected to corona discharge treatment, and the coating liquid (D-1) was applied to both treatment surfaces. The uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A laminate (i) having a thickness of 100 μm was obtained in which a 0.08 μm-thick crosslinked heat resistant water adhesion improving layer (D1) was laminated on both sides of the biaxially stretched polyethylene terephthalate base film (E1). .

(3) Preparation of release layer (B) forming coating solution “Vylonal (registered trademark) MD-1200” (manufactured by Toyobo Co., Ltd.), which is a water-dispersible copolyester resin, is used as a binder resin. Polyethylene emulsion wax agent (manufactured by Riken Vitamin Co., Ltd.) as an anionic antistatic agent (sodium dodecyl diphenyl oxide disulfonate; trade name TB702; manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) as an antistatic agent. Styrene-benzoguanamine-based spherical organic particles “Eposter (registered trademark) MS” (manufactured by Nippon Shokubai Co., Ltd.) having a particle size of 2 μm and colloidal silica “Snowtex (registered trademark) XL” (Nissan Chemical Industries) having an average particle size of 0.05 μm Were used respectively.

  Using a homogenizer, the organic spherical fine particles of the surface roughening material are sufficiently dispersed in a mixed solution of water and isopropyl alcohol (mass ratio 80/20), and then the binder with respect to the total mass of the coating solution. The coating solution is thoroughly mixed so that the resin is 2.5%, the polymer wax component is 0.13%, the antistatic agent is 0.13%, the organic spherical fine particles are 0.025%, and the colloidal silica is 0.3%. (B-1) was prepared.

(4) Manufacture of polyester film (A) and lamination of release layer (B) Pellets of polyethylene terephthalate (intrinsic viscosity 0.65 dl / g) are sufficiently dried in vacuum and then supplied to a heated extruder at 280 ° C. Then, the sheet was extruded from a T-shaped base into a sheet shape, wound around a mirror casting drum having a surface temperature of 30 ° C. using an electrostatic application casting method, and cooled and solidified. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. The coating liquid (B-1) prepared by the above method was applied to both surfaces of this uniaxially oriented film. The coated uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A 50 μm-thick laminate (iii) (corresponding to the separate film AB-1) in which a release layer (B-1) having a thickness of 0.15 μm was laminated on both sides of the polyester film (A-1) was obtained.

(5) Lamination of pressure-sensitive adhesive layer (C) Non-reactive consisting of an uncrosslinked polydimethylsiloxane skeleton having substantially no reinforcing agent such as silica and having a number average molecular weight of 150,000 (measured by GPC method, converted to polystyrene) The silicone compound (KF-96H-500,000 cs; manufactured by Shin-Etsu Chemical Co., Ltd.) was weighed so that the mass ratio to toluene was 23%, and was put together with toluene into a stirrer equipped with a vacuum defoaming device. The mixture was stirred at room temperature for 15 hours and dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added to 100 parts of the silicone compound so as to be 2 parts, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. Stir under vacuum for another 20 minutes and degas. Next, the defoamed silicone compound solution is supplied to a roll coater, and the silicone compound solution is applied to one side of the laminate (i) so that the thickness after drying is 25 μm, and then introduced into an oven. Dry at 80 ° C. A laminate (ii) in which an uncrosslinked adhesive layer (C-1) was formed on the surface of the laminate (i) was obtained.

The laminated body (iii) was stacked on the surface of the uncrosslinked adhesive layer (C-1) of the laminated body (ii) while being pressed by a pressure roller (pressure 30 N / cm ² ) and continuously laminated. The obtained laminate (iv) was further continuously introduced into an electron beam irradiation apparatus, and the adhesive layer was crosslinked by irradiating an electron beam with an energy of 200 KV and 18 Mrad from the polyester film (A-1) side. The laminate (iv ′) provided with the pressure-sensitive adhesive layer (C) after crosslinking was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (AB) was not observed.

(6) Lamination of acrylic pressure-sensitive adhesive layer (F) SK Dyne 2094 (manufactured by Soken Chemical Co., Ltd.), which is an acrylic pressure-sensitive adhesive for optics, It apply | coated so that the thickness after drying might be set to 25 micrometers, and it dried at 130 degreeC for 3 minute (s), and formed the acrylic adhesive layer (F). The adhesive layer (F) is laminated so that the silicone-treated surface side of a 38 μm-thick separate film (G) (E7002; manufactured by Toyobo Co., Ltd.) made of silicone-treated polyethylene terephthalate is in contact with the adhesive layer (F). A sheet was obtained. Even in this step, the occurrence of the channeling phenomenon of the separate film (G) was not observed.

  Table 1 shows the characteristics of the double-sided PSA sheet obtained in Example 1 and the characteristics of the coating liquid for forming the PSA layer (C).

  The double-sided pressure-sensitive adhesive sheet obtained in this example is excellent in transparency, and the pressure-sensitive adhesive layer (C) is firmly bonded to the polyester base film (E) through the heat resistant water adhesion improving layer (D). It had been. Moreover, the peeling force of a mold release layer (B) and an adhesion layer (C) was also moderate, and it was a high-quality double-sided adhesive sheet. Furthermore, it was confirmed that the coating liquid for forming the pressure-sensitive adhesive layer (C) in the production of the double-sided pressure-sensitive adhesive sheet was excellent in clarification and stability, and excellent in operability and operational stability.

Comparative Example 1
In the method of Example 1, a double-sided PSA sheet was obtained in the same manner as in Example 1 except that the application of the coating liquid (D-1) for forming the heat resistant water adhesion improving layer (D) was stopped. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 1 was inferior in the peel strength between the PSA layer (C) and the base film (E) and the hot water adhesiveness, and was of low quality.

Comparative Example 2
In the method of Example 1, it was the same as Example 1 except that the blending of the methylolated melamine resin as a crosslinking agent was stopped in the coating liquid (D-1) for forming the heat resistant water adhesion improving layer (D). Thus, a double-sided PSA sheet was obtained. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 2 was poor in heat resistant water adhesion between the PSA layer (C) and the substrate film (E), and was of low quality.

Comparative Example 3
In the method of Example 1, the same method as in Example 1 except that the combination of the polymer wax component and the antistatic agent in the coating liquid (B-1) for forming the release layer (B) was stopped. A double-sided PSA sheet was obtained. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 3 tried to peel the separate film (AB) from the PSA layer (C) but could not be peeled off. Therefore, it could not be used as a double-sided PSA sheet.

Comparative Examples 4 and 5
In the method of Example 1, in the release layer (B) forming coating solution (B-1), the polymer wax component in Comparative Example 4 and the blending of the antistatic agent in Comparative Example 5 are stopped. Except for the above, a double-sided PSA sheet was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 4 was unable to peel the separate film (AB) from the PSA layer (C). In Comparative Example 5, the peel strength of the separate film (AB) was high, and the peelability of the separate film (AB) was inferior.

Comparative Example 6
In the method of Example 1, double-sided adhesion was performed in the same manner as in Example 1 except that a silicone-treated release polyester film having a thickness of 38 μm (E7002; manufactured by Toyobo Co., Ltd.) was used as the separate film (AB). A sheet was obtained. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 6 was not able to be peeled off in the same manner as in Comparative Example 3, although an attempt was made to peel the separate film from the adhesive layer (C). It is presumed that the cross-linking adhesion phenomenon occurred due to EB cross-linking. Therefore, it could not be used as a double-sided PSA sheet.

Comparative Example 7
In the method of Example 1, a double-sided PSA sheet was obtained in the same manner as in Example 1 except that the thickness of the heat resistant water adhesion improving layer (D) was changed to 0.7 μm. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Comparative Example 7 was inferior in heat resistant water adhesion of the PSA layer (C) and was of low quality.

Comparative Example 8
A double-sided PSA sheet was obtained in the same manner as in Comparative Example 2, except that the preparation of the adhesive layer (C) forming coating solution was changed as shown below by the method of Comparative Example 2. The evaluation results are shown in Table 1.

[Preparation of adhesive layer (C) forming coating solution]
High transparency silicone rubber compound (“TSE260-3U”; rubber hardness 30 degrees) composed of 60 parts of a polydimethylsiloxane skeleton silicone compound, 25 parts of a polydimethylalkenylsiloxane skeleton silicone compound and 15 parts of silica; Momentive Performance Materials (Made by Japan) was weighed so that the mass ratio with respect to toluene might be 23%, and it poured into the stirrer with a vacuum degassing apparatus with toluene, and it stirred at room temperature for 15 hours under atmospheric pressure, and was dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added so as to be 2 parts with respect to 100 parts of the rubber compound, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. The mixture was further stirred for 20 minutes and degassed. In addition, the said silicone rubber compound used what passed 6 months after purchase.

  In addition to the problem of the double-sided PSA sheet obtained in Comparative Example 2, the double-sided PSA sheet obtained in Comparative Example 8 was inferior in the clarity and storage stability of the coating solution.

Reference example 1
In the method of Example 1, 8 parts of organic silicone (“KS-744”; manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst “PL-3” (Shin-Etsu) were used as the coating solution for forming the hot water resistant adhesion improving layer (D). A double-sided PSA sheet was obtained in the same manner as in Example 1 except that 0.06 part (made by Chemical Industry Co., Ltd.) was changed to a solution in which 100 parts by mass of toluene was dissolved. The evaluation results are shown in Table 1.

  The double-sided PSA sheet obtained in Reference Example 1 was inferior in heat resistant water adhesion between the PSA layer (C) and the substrate film (E), and was of low quality.

Example 2
A polyester-based substrate film (E-2) was produced in the same manner as in Example 1 except that the coating of the coating liquid (D-1) was stopped during the production of the polyester-based substrate film (E) of Example 1. ) Corona treatment was performed on both surfaces of this base film (E-2). Separately, a copolymerized polyester resin solution (“Byron (registered trademark) 30SS”; manufactured by Toyobo Co., Ltd.) and a polyisocyanate-based crosslinking agent (“Coronate (registered trademark) HX”; manufactured by Nippon Polyurethane Co., Ltd.) It mix | blended so that it might become 100: 3 (part), and the coating liquid (D-2) for heat-resistant water adhesive improvement layers (D) was prepared. This coating liquid (D-2) was applied to both surfaces of the base film (E-2) after the corona treatment using a coater and dried. A laminate (i) was obtained in which the cross-linked heat resistant water adhesion improving layer (D-2) was laminated on both surfaces of the base film (E-2). Using this laminate (i), a double-sided PSA sheet was obtained in the same manner as in Example 1. In addition, the thickness of the hot water resistant adhesiveness-improving layer (D-2) after biaxial stretching was 0.31 μm. The evaluation results are shown in Table 2.

  The double-sided pressure-sensitive adhesive sheet obtained in this example had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality.

Comparative Example 9
In the preparation of the coating liquid (D-2) of Example 2, double-sided adhesion was carried out in the same manner as in Example 1 except that the formulation of “Coronate HX” as a crosslinking agent was stopped and only “Byron 30SS” was used. A sheet was obtained. The evaluation results are shown in Table 2.

  The double-sided PSA sheet obtained in Comparative Example 9 was inferior in the heat resistant water adhesion of the PSA layer (C) and was of low quality.

Examples 3-6
A double-sided PSA sheet was obtained in the same manner as in Example 1 except that the coating liquid (D-1) for the heat resistant water adhesion improving layer in Example 1 was changed to the following composition. The evaluation results are shown in Table 2.

  The double-sided PSA sheet obtained in these examples had the same characteristics as the double-sided PSA sheet obtained in Example 1, and was of high quality.

[Coating liquid of Example 3]
10 parts of the “Cymel 303” and 0.04 part of the “Catalyst 600” with respect to 100 parts of the solid content of the acrylic emulsion (“Joncrill (registered trademark) PDX-7630A”; manufactured by BASF Japan). Were mixed to obtain a coating solution (D-3) for the heat resistant water adhesion improving layer.

[Coating liquid of Example 4]
As an oxazoline-based cross-linking agent ("Epocross (registered trademark) WS-700"; Nippon Shokubai Co., Ltd.) with respect to 100 parts of a solid content of a polyurethane-based aqueous dispersion ("Hydran (registered trademark) AP40"; manufactured by Dainippon Ink and Industry). Product) was added in a solid content to give a coating solution (D-4) for a heat resistant water adhesion improving layer.

[Coating liquid of Example 5]
7.5 parts of water-dispersible copolyester “Vylonal (registered trademark) MD-1200” (manufactured by Toyobo Co., Ltd.), 20% aqueous solution of self-crosslinking polyurethane containing isocyanate groups blocked with sodium bisulfite (“Elastron ( (Registered trademark) H-3 "; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 11.3 parts, catalyst for elastron (" Cat 64 "; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts, water 39.8 parts and isopropyl alcohol 37. Four parts were placed in a container and mixed well.

  Further, 0.6 parts of a 10% aqueous solution of a fluorine-based nonionic surfactant (“Megafac (registered trademark) F142D”; manufactured by Dainippon Ink & Chemicals, Inc.), colloidal silica (“Snowtex (registered trademark) OL”) Average particle size 40 nm; 2.3 parts of 20% aqueous dispersion of Nissan Chemical Industries, Ltd., dry silica (“Aerosil OX50”; “Aerosil” is a registered trademark of Degussa; average particle size 200 nm; average primary particle; 0.5 parts of a 3.5% aqueous dispersion of 40 nm in diameter; manufactured by Nippon Aerosil Co., Ltd. was added. Next, the pH of the coating solution is adjusted to 6.2 with a 5% aqueous sodium bicarbonate solution, and the solution is precisely filtered through a felt type polypropylene filter having a filtration particle size (initial filtration efficiency: 95%) of 10 μm, and is resistant to hot water. It was set as the coating liquid for improved layers (D-5).

[Coating liquid of Example 6]
40 parts of a self-crosslinking polyester resin aqueous dispersion “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.), 24 parts of water and 36 parts of isopropyl alcohol are mixed, and a 10% aqueous solution of an anionic surfactant 0.6 Part, propionate 1 part, colloidal silica particles (“Snowtex (registered trademark) OL”; average particle size 40 nm; manufactured by Nissan Chemical Industries, Ltd.)) 1.8% 20% aqueous dispersion, dry process silica particles (“ Aerosil OX50 "; average particle size 200 nm; average primary particle size 40 nm; manufactured by Nippon Aerosil Co., Ltd.) 4 parts aqueous dispersion 1.1 parts, and the heat resistant water adhesion improving layer coating solution (D-6) and did.

Example 7
In the method of Example 1, a double-sided PSA sheet was obtained in the same manner as in Example 1 except that a separate film (AB-2) produced by the following method was used. The evaluation results are shown in Table 2.

[Preparation of Separate Film (AB-2)]
The coating liquid (B-1) used in the manufacture of the separate film (AB-1) of Example 1 was applied onto a polyester film (A: 100 μm) using a wire bar (No. 5). The coating amount of the coating liquid (B-1) was about 8 to 10 g (wet state) per 1 m ^{2 of the} base film. The film was dried at 160 ° C. for about 60 seconds to obtain a separate film (AB-2).

  The double-sided pressure-sensitive adhesive sheet obtained in Example 7 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was high quality. Further, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet.

Example 8
In the method of Example 1, the polymer wax of the release layer coating liquid used for the production of the separate film (AB-1) was changed to an acrylic wax agent emulsion (“ST-200”; manufactured by Nippon Shokubai Co., Ltd.). A double-sided PSA sheet was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 2.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 8 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality. Further, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet.

Example 9
In the method of Example 1, the antistatic agent of the release layer coating solution used for the production of the separate film (AB-1) is changed to an anionic antistatic agent (“TB214”; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Except for the above, a double-sided PSA sheet was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 9 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was high quality. Further, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet.

Example 10
In the method of Example 1, the polymer wax component of the release layer coating solution used for the production of the separate film (AB-1) is changed to 0.2% and the antistatic agent to 0.3%. Except for the above, a double-sided PSA sheet was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 10 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was high quality. Further, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet.

Comparative Example 10
In the method of Example 1, the release layer coating liquid used for the production of the separate film (AB-1) is changed so that the polymer wax component is 1.3% and the antistatic agent is 1.5%. Except for the above, a double-sided PSA sheet was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.

  The peel strength of the separate film (AB) of the double-sided pressure-sensitive adhesive sheet obtained in Comparative Example 10 was almost 0 N / 20 mm, and the peelability was very good, but the polyester film laminate (iv) and double-sided pressure-sensitive adhesive sheet During the production of the film, the separation film (AB) sometimes floated.

Example 11
In the method of Example 1, a double-sided PSA sheet was obtained in the same manner as in Example 1 except that the laminating method of the adhesive layer (C) was changed as follows. The results are shown in Table 3.
[Lamination of adhesive layer (C-2)]
A non-reactive silicone compound (KF-96H-1 million) comprising an uncrosslinked polydimethylsiloxane skeleton having substantially no reinforcing agent such as silica and having a number average molecular weight of 170,000 (measured by GPC method, converted to polystyrene) cs; manufactured by Shin-Etsu Chemical Co., Ltd.) was weighed so that the mass ratio with respect to toluene was 23%, and was put together with toluene into a stirrer equipped with a vacuum deaerator and stirred in atmospheric pressure at room temperature for 15 hours to dissolve in toluene. I let you. To the obtained solution, trimethylolpropane trimethacrylate was added to 100 parts of the silicone compound so as to be 2 parts, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. Stir under vacuum for another 20 minutes and degas. Next, the defoamed silicone compound solution was supplied to a roll coater, and the silicone compound solution was applied to one side of the laminate (i) produced in Example 1 so that the thickness after drying was 25 μm. It introduce | transduced into oven and dried at 80 degreeC. A laminate (ii) in which an uncrosslinked adhesive layer (C-2) was formed on the surface of the laminate (i) was obtained.

While the laminate (iii) produced in Example 1 is stacked on the surface of the uncrosslinked adhesive layer (C-2) of the laminate (ii), the laminate (ii) is continuously pressed by a pressure roller (pressure 30 N / cm ² ). Laminated. The obtained laminate (iv) was further continuously introduced into an electron beam irradiation apparatus, and irradiated with an electron beam at an energy of 200 KV and 18 Mrad from the polyester film (A-1) side, thereby giving an adhesive layer (C-2). Then, the cross-linked laminate (iv ′) was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (AB) was not observed.

  The double-sided pressure-sensitive adhesive sheet obtained in this example had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality.

Example 12
The acrylic pressure-sensitive adhesive solution used in Example 1 was applied to the silicone-treated surface of the separate film (G) used in the method of Example 1 so that the thickness after drying was 25 μm. It dried for minutes and formed the acrylic adhesive layer (F-1). Laminate (i) side surface of the laminate (iv ′) produced by the method of Example 1 is laminated on the surface of this acrylic adhesive layer (F-1) to obtain a double-sided adhesive sheet. And rolled up into a roll. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 3.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 12 had the same properties as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was high quality.

Example 13
An adhesive layer (C-1) was formed on one side of the laminate (iii) produced in Example 1 by the same method as in Example 1. The laminate (i) produced in Example 1 was laminated on the surface of the adhesive layer (C-1) to obtain a laminate (iv). The obtained laminate (iv) was further continuously introduced into an electron beam irradiation apparatus, and the adhesive layer (C-1) was crosslinked in the same manner as in Example 1 to obtain a laminate (iv ′). Using this laminate (iv ′), a double-sided PSA sheet was obtained in the same manner as in Example 1, and wound up into a roll. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 3.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 13 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality.

Example 14
A double-sided PSA sheet was produced in the same manner as in Example 12 using the laminate (iv ′) produced in the same manner as in Example 13. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 3.

  The double-sided PSA sheet obtained in Example 14 had the same characteristics as the double-sided PSA sheets obtained in Examples 12 and 13, and was high quality.

Example 15
The acrylic adhesive solution used in Example 1 was applied to the surface of the laminate (i) of the laminate (iv) obtained by the method of Example 13 so that the thickness after drying was 25 μm, and 130 It dried for 3 minutes at ° C. to form an acrylic pressure-sensitive adhesive layer (F-1). A laminate (vii) was produced by laminating the surface of this acrylic pressure-sensitive adhesive layer (F-1) so that the silicone-treated surface of the separate film (G) used in the method of Example 1 was in contact therewith. The obtained laminate (vii) was continuously introduced into an electron beam irradiation apparatus, and irradiated with an electron beam at an energy of 200 KV and 18 Mrad from the polyester film (A-1) side, thereby giving an adhesive layer (C-1). Then, a double-sided PSA sheet was produced. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 3.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 15 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 13, and was of high quality.

Example 16
The acrylic pressure-sensitive adhesive solution used in Example 1 was applied to the silicone-treated surface of the separate film (G) used in the method of Example 1 so that the thickness after drying was 25 μm. It dried for minutes and formed the acrylic adhesive layer (F-1). The laminate (vii) is laminated so that the surface of the acrylic adhesive layer (F-1) is in contact with the laminate (i) side surface of the laminate (iv) produced by the method of Example 1. Manufactured. The obtained laminate (vii) was continuously introduced into an electron beam irradiation apparatus, and irradiated with an electron beam at an energy of 200 KV and 18 Mrad from the polyester film (A-1) side, thereby giving an adhesive layer (C-1). Then, a double-sided PSA sheet was produced. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 4.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 16 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality.

Example 17
SK Dyne 2094 (manufactured by Soken Chemical Co., Ltd.), which is an optical acrylic adhesive, was dried on the surface of the laminate (i) side of the laminate (iv) produced by the same method as in Example 1 after drying. Was applied to a thickness of 25 μm and dried at 130 ° C. for 3 minutes to form an acrylic pressure-sensitive adhesive layer (F). The surface of this pressure-sensitive adhesive layer (F) was laminated so that the silicone-treated surface side of a 38 μm-thick separated film (G) (E7002; manufactured by Toyobo Co., Ltd.) made of silicone-treated polyethylene terephthalate was in contact with the laminate. (vii) was produced. The obtained laminate (vii) was continuously introduced into an electron beam irradiation apparatus, and irradiated with an electron beam at an energy of 200 KV and 18 Mrad from the polyester film (A-1) side, thereby giving an adhesive layer (C-1). Then, a double-sided PSA sheet was produced. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 4.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 17 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in the above-mentioned Examples, and was high quality.

Example 18
A double-sided PSA sheet was produced in the same manner as in Example 16 using the laminate (iv) produced in the same manner as in Example 13. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 4.

  The double-sided PSA sheet obtained in Example 18 had the same properties as the double-sided PSA sheets obtained in Examples 13 and 16, and was high quality.

Example 19
The acrylic pressure-sensitive adhesive solution used in Example 1 was applied to the silicone-treated surface of the separate film (G) used in the method of Example 1 so that the thickness after drying was 25 μm. It dried for minutes and formed the acrylic adhesive layer (F-1). Another separate film (G) was laminated on the surface of this acrylic pressure-sensitive adhesive layer (F-1) to form a laminate (viii).

  On the other hand, a laminate (iv ′) was produced in the same manner as in Example 1. While peeling the separate film (G) on one side of the laminate (viii), the acrylic pressure-sensitive adhesive layer (F-1) is in contact with the laminate (i) side surface of the laminate (iv ′). Both were laminated | stacked and the double-sided adhesive sheet was manufactured. In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 4.

  The double-sided pressure-sensitive adhesive sheet obtained in Example 19 had the same properties as the double-sided pressure-sensitive adhesive sheet obtained in Example 1, and was of high quality.

Example 20
A laminate (viii) was formed in the same manner as in Example 19, and a laminate (iv ′) was produced in the same manner as in Example 13. A double-sided PSA sheet was produced in the same manner as in Example 19 using the laminate (viii) and laminate (iv ′). In the manufacturing process, the occurrence of the channeling phenomenon of the separate film (AB) was not observed. The evaluation results are shown in Table 4.

  The double-sided PSA sheet obtained in Example 20 had the same characteristics as the double-sided PSA sheet obtained in Examples 13 and 19, and was high quality.

Example 21
Using the double-sided pressure-sensitive adhesive sheets obtained in Examples 1 to 20, an overlay sheet that is a face sheet of a capacitive touch panel and a coordinate detection sheet were bonded together. First, an overlay sheet was attached to the acrylic adhesive layer (F) side, and then a coordinate detection sheet was attached using the adhesive layer (C). The workability of these sticking steps was good. In addition, since the adhesive layer (C) is excellent in repairability, it could be easily repaired even if a sticking error occurred. Therefore, it was possible to eliminate the occurrence of defective products due to a sticking mistake. Further, for example, when the adhesive layer (C) side is bonded so as to be an overlay sheet, similarly, the loss of the overlay sheet due to a bonding error can be eliminated.

Example 22
Using the double-sided PSA sheet obtained in Examples 1 to 20, the touch panel portion of the resistive touch panel and the display device were bonded. Similar to Example 21, the workability of the attaching process was good. Further, for example, when pasting so that the adhesive layer (C) side becomes a display device, similarly to Example 21, the loss of the display device due to a sticking mistake could be eliminated.

  Since the double-sided pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer made of a silicone compound and a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive, it is useful for fixing not only the same kind of member but also a different kind of member. Moreover, since transparency is high, it is suitable for bonding optical members, and is particularly excellent as a touch panel member. Furthermore, the production method of the present invention can economically produce a high-quality double-sided pressure-sensitive adhesive sheet, which is advantageous in terms of cost.

Claims (19)

  Polyester film (A), release layer (B), pressure-sensitive adhesive layer (C) containing a crosslinked silicone compound having a polydimethylsiloxane skeleton, heat resistant water adhesion improving layer (D), polyester base film (E) The double-sided pressure-sensitive adhesive sheet in which the acrylic pressure-sensitive adhesive layer (F) and the separate film (G) are laminated in the order of A to G, and the release layer (B) measured by the method defined in the specification And the adhesive layer (C) have a peel strength of 0.03 to 1.0 N / 20 mm.   The double-sided pressure-sensitive adhesive sheet according to claim 1, wherein the release layer (B) comprises a non-silicone compound.   The double-sided pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the release layer (B) is a layer containing a binder resin, a polymer wax component and an antistatic agent.   The heat resistant water adhesion improving layer (D) comprises a reaction product of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent. The double-sided pressure-sensitive adhesive sheet according to any one of the above.   The hot-water-resistant adhesion improving layer (D) contains one or more self-crosslinking polymers selected from the group consisting of self-crosslinking polyester, polyurethane and acrylic polymer, which are self-crosslinked. The double-sided adhesive sheet in any one of 1-4.   The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the crosslinked silicone compound is obtained by crosslinking an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000.   The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer (C) is not peeled off when the hot water adhesion is evaluated by a method defined in the specification. A method for producing the double-sided pressure-sensitive adhesive sheet according to claim 1,
A step of laminating the heat resistant water adhesion improving layer (D) on one side of the polyester base film (E) to form a laminate (1);
A step of forming a laminate (2) by laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the heat resistant water adhesion improving layer (D) of the laminate (1);
A step of laminating the release layer (B) on one side of the polyester film (A) to form a laminate (3);
The laminates (2) and (3) are formed so that the release layer (B) of the laminate (3) is in contact with the surface of the layer (2) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton. ) To form a laminate (4),
A step of crosslinking a non-crosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (4) to form a laminate (4 ′) having an adhesive layer (C);
On the surface of the polyester base film (E) of the laminate (4 ′), with or without another heat resistant water adhesion improving layer (D), an acrylic pressure-sensitive adhesive layer (F) and a separate film ( G) are laminated in this order,
The manufacturing method of the double-sided adhesive sheet characterized by including. A method for producing the double-sided pressure-sensitive adhesive sheet according to claim 1,
A step of laminating an acrylic pressure-sensitive adhesive layer (F) on one side of a separate film (G) to form a laminate (5);
Each step of forming the laminate (1), laminate (2), laminate (3), laminate (4) and laminate (4 ') according to claim 8,
The polyester-based substrate film (E) of the laminate (4 ′) is laminated with or without the laminate (4 ′) and laminate (5) with or without another heat resistant water adhesion improving layer (D). A step of laminating so as to be on the acrylic adhesive layer (F) side of the body (5),
The manufacturing method of the double-sided adhesive sheet characterized by including. A method for producing the double-sided pressure-sensitive adhesive sheet according to claim 1,
Forming the laminate (3) according to claim 8,
A step of laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the release layer (B) of the laminate (3) to form a laminate (6);
Forming the laminate (1) according to claim 8;
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4) according to claim 8,
Forming the laminate (4 ') according to claim 8;
On the surface of the polyester base film (E) of the laminate (4 ′), with or without another heat resistant water adhesion improving layer (D), an acrylic pressure-sensitive adhesive layer (F) and a separate film ( G) are laminated in this order,
The manufacturing method of the double-sided adhesive sheet characterized by including. A method for producing the double-sided pressure-sensitive adhesive sheet according to claim 1,
Forming the laminate (5) according to claim 9,
Forming the laminate (3) according to claim 8,
Forming the laminate (6) according to claim 10,
Forming the laminate (1) according to claim 8;
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4),
Forming the laminate (4 ') according to claim 8;
The polyester-based substrate film (E) of the laminate (4 ′) is laminated with or without the laminate (4 ′) and laminate (5) with or without another heat resistant water adhesion improving layer (D). A step of laminating so as to be on the acrylic adhesive layer (F) side of the body (5),
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Each step of forming the laminate (1), laminate (2), laminate (3) and laminate (4) according to claim 8,
An acrylic pressure-sensitive adhesive layer (F) and a separate film (G) may be formed on the surface of the polyester base film (E) of the laminate (4) with or without another heat resistant water adhesion improving layer (D). ) In this order to form a laminate (7),
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Forming the laminate (5) according to claim 9,
Each step of forming the laminate (1), laminate (2), laminate (3) and laminate (4) according to claim 8,
The laminated body (4) and the laminated body (5) are passed through the laminated body (4) with the polyester-based substrate film (E) through the laminated body (4) with or without another hot water resistant adhesion improving layer (D). The step of laminating so as to be on the acrylic pressure-sensitive adhesive layer (F) side of 5) and forming the laminate (7) according to claim 12,
Cross-linking the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Forming the laminate (3) according to claim 8,
Forming the laminate (6) according to claim 10,
Forming the laminate (1) according to claim 8;
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4) according to claim 8,
Forming the laminate (7) according to claim 12,
Cross-linking the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Forming the laminate (5) according to claim 9,
Forming the laminate (3) according to claim 8,
Forming the laminate (6) according to claim 10,
Forming the laminate (1) according to claim 8;
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4) according to claim 8,
The laminated body (4) and the laminated body (5) are passed through the laminated body (4) with the polyester-based substrate film (E) through the laminated body (4) with or without another hot water resistant adhesion improving layer (D). The step of laminating so as to be on the acrylic adhesive layer (F) side of 5) and forming the laminate (7) according to claim 12,
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Each step of forming the laminate (1), laminate (2), laminate (3), laminate (4), laminate (4 ') according to claim 8,
Forming the laminate (5) according to claim 9,
A step of laminating another separate film (G ′) on the surface of the acrylic pressure-sensitive adhesive layer (F) of the laminate (5) to form a laminate (8);
While peeling off the separate film (G) or the separate film (G ′) of the laminate (8), the acrylic pressure-sensitive adhesive layer (F) is formed on the surface of the polyester base film (E) of the laminate (4 ′). Laminating so that the
The manufacturing method of the double-sided adhesive sheet characterized by including. It is a manufacturing method of the double-sided adhesive sheet in any one of Claims 1-7,
Forming the laminate (3) according to claim 8,
Forming the laminate (6) according to claim 10,
Laminate (6) so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in the laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer (D) of the laminate (1). And laminating the laminate (1) to form the laminate (4) according to claim 8,
Forming the laminate (4 ') according to claim 8;
Forming the laminate (8) according to claim 16,
While peeling off the separate film (G) or the separate film (G ′) of the laminate (8), the acrylic pressure-sensitive adhesive layer (F) is formed on the surface of the polyester base film (E) of the laminate (4 ′). Laminating so that the
The manufacturing method of the double-sided adhesive sheet characterized by including.   A method for using a double-sided pressure-sensitive adhesive sheet, wherein the double-sided pressure-sensitive adhesive sheet according to claim 1 is used for adhering an overlay sheet and a coordinate detection sheet of a capacitive touch panel.   The use method of the double-sided adhesive sheet characterized by using the double-sided adhesive sheet in any one of Claims 1-7 for adhesion | attachment with the touch panel of a resistive film type touch panel, and a display apparatus.