JP2011202045A - Method for producing tacky adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a tacky adhesive sheet, by which a tacky adhesive sheet can be produced at a low cost by a winding system in current equipment with fewer air bubbles entangled during production even when the tacky adhesive layer comprises a core material impregnated with a tacky adhesive.SOLUTION: The method includes: laminating a core material 15 on the release layer face of a first release sheet 21A, applying a tacky adhesive 13 to the core 15 face; then laminating the release layer face of a second release sheet 21B on the adhesive; pressurizing and winding up the laminate to obtain a tacky adhesive sheet. The tacky adhesive sheet comprises the first release sheet 21A, the tacky adhesive layer 11 comprising the core material impregnated with the tacky adhesive, and the second release sheet 21B. The sheet has both of tackiness and adhesiveness. The tacky adhesive 13 contains an acrylic resin, an epoxy resin and a curing agent.

Description

  The present invention relates to a method for producing an adhesive sheet, and more specifically, an adhesive sheet having both adhesiveness and adhesiveness and having few bubbles is manufactured at low cost by a winding method using existing equipment. It is related with the manufacturing method of the adhesive sheet for this.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. In the present specification, “adhesive sheet” means “a sheet having an adhesive force at the moment of being attached to a substrate and then having an adhesive force by heating”, and “adhesive force” means “base”. “Adhesive strength” means “force that physically adheres by heating after being applied to a substrate”.

(Background Art) Conventionally, as a joining method for integrating two adherends, there are an occlusion, welding, and an adhesion method using an adhesive or a pressure-sensitive adhesive, and they are frequently used depending on the application in each field. In recent years, in applications related to transport equipment such as automobiles, as a solution to problems such as the reduction of carbon dioxide CO2 emissions to prevent global warming, the weight reduction of vehicle bodies and the spread of hybrid cars and electric cars have been promoted. For this reason, there is a growing trend to use lightweight aluminum and magnesium, FRP (CFRP = carbon fiber reinforced plastics, GFRP = garas fiber reinforced plastics) for the vehicle body. However, it is extremely difficult to weld dissimilar materials such as aluminum and iron with conventional welding methods, and welding itself is impossible in the case of FRP of glass fiber or carbon fiber. A bonding material that can be strongly bonded is required. As a joining method, there is a method using an adhesive sheet or an adhesive sheet. The adhesive layer formed by impregnating the core material with the adhesive will embed bubbles during production, and these bubbles will foam when bonded to the adherend, resulting in poor adhesion and poor appearance. It becomes. In addition, the adhesive sheet with few bubbles has a high production cost because the production speed is remarkably reduced or vacuum treatment is required.
Therefore, in the method for producing an adhesive sheet, even if the adhesive layer is formed by impregnating the core material with the adhesive, there are few bubbles to be embraced in the production, and it is wound with existing equipment. It is required to manufacture at a low cost by a take-off method.

JP-A-3-14888

(Prior art) Conventionally,
Thermosetting sheet-like adhesive having a surface containing a thermosetting adhesive and a surface containing a pressure sensitive adhesive on the same surface of a woven or non-woven fabric having a mesh size of 1 to 50 mesh Is known (for example, see Patent Document 1). However, a pressure-sensitive adhesive (adhesive) is applied in the form of a stripe having a width and a thermosetting adhesive is applied between the stripes. It does not have. In addition, when impregnating with an adhesive, it is described that the adhesive is not sufficiently impregnated, and that the adhesive is insufficiently supported and falls off, and there is a risk of air bubbles embraced during production, Although it can be manufactured with existing facilities, there are problems that the number of processes is large and the cost is not low.

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is to produce less adhesive bubbles even when the adhesive layer is made by impregnating the core material with the adhesive, and it can be manufactured at low cost with existing equipment by winding It is providing the manufacturing method of the adhesive sheet which can be performed.

In order to solve the above-mentioned problems, the method for producing an adhesive sheet according to the invention of claim 1 of the present invention includes a first release paper, an adhesive layer formed by impregnating a core material with an adhesive, And a second release paper, wherein the adhesive comprises an acrylic resin, an epoxy resin, and a curing agent, and is a method for producing an adhesive sheet having both adhesiveness and adhesiveness. The core material is overlaid on the release layer surface of the pattern paper, and after the adhesive agent is applied to the core material surface, the release layer surface of the second release paper is overlaid and pressurized and wound up, It is a thing.
According to a second aspect of the present invention, there is provided a method for producing an adhesive sheet, wherein the acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN, and the epoxy resin is NBR ( (Nitrile butadiene rubber) It is composed of a modified epoxy resin and a bis-A type epoxy resin so that the curing agent is a dicyandiamide compound.
According to a third aspect of the present invention, there is provided a method for producing an adhesive sheet, wherein the adhesive includes an acrylic resin and an epoxy resin having a sea-island structure.

According to the first aspect of the present invention, even in the adhesive layer formed by impregnating the core material with the adhesive, there are few air bubbles to be embraced in the production, and the winding system is used with existing equipment. Thus, an effect that can be manufactured at low cost is achieved.
According to the second to third aspects of the invention, in addition to the effect of the first aspect, there is an effect that a stronger and more stable adhesive strength can be obtained.

It is sectional drawing of the adhesive sheet manufactured with the manufacturing method of the adhesive sheet of this invention. It is explanatory drawing explaining the process of the manufacturing method of the adhesive sheet | seat of this invention. It is side sectional drawing of the principal part of the coating device used for this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (Adhesive sheet) First, as shown in FIG. 1, the adhesive sheet 1 manufactured by the method for manufacturing an adhesive sheet according to the present invention has a first release paper 21A, an adhesive layer 11, and a first adhesive sheet. The adhesive layer 11 is impregnated with the core material 15 in the adhesive layer 11, and the adhesive agent 13 constituting the adhesive layer 11 is an acrylic resin or an epoxy resin. And an adhesive sheet containing a curing agent and having both tackiness and adhesiveness. The acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN, and the epoxy resin is composed of an NBR (nitrile butadiene rubber) -modified epoxy resin and a bisphenol-type epoxy resin. Thus, the curing agent is preferably a dicyandiamide-based compound. Note that EA-BA-AN represents ethyl acrylate-butyl acrylate-acrylonitrile. Furthermore, it is preferable that the adhesive layer 11 has a sea-island structure of an acrylic resin and an epoxy resin.

  Most preferably, an acrylic resin and an epoxy resin are used as the adhesive 13 constituting the adhesive layer 11, and the epoxy resin is at least a soft rubbery epoxy resin NBR (nitrile (Butadiene rubber) A modified epoxy resin and a hard bisphenol epoxy resin, and the acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN having adhesiveness. By using a polymer and using a dicyandiamide-based compound as the curing agent, the thermosetting adhesive sheet 1 satisfying the following performance and having initial adhesion can be obtained. That is, the adhesive sheet 1 has (1) initial tackiness, no steps such as preheating and good workability, and (2) adhesion between metals, metal and organic material, and organic material and organic material. (3) Adhesive strength is strong so that it can be used for structural applications, and (4) Adhesive strength has the effect of not deteriorating with temperature changes.

  (Release paper) In this specification, the first release paper 21A and the second release paper 21B are collectively referred to as release paper 21. Further, the first release paper 21A and the second release paper 21B may be the same or different. The release paper 21 is also called a release film, a separate paper, a separate film, a separate paper, a release film, and a release paper. The release paper 21 has a release layer on one or both sides of a release paper substrate such as fine paper, coated paper, impregnated paper, and plastic film.

  (Release layer) The release layer is not particularly limited as long as it is a material having releasability. For example, silicone resin, organic resin-modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic Resin, polyester resin and the like. These resins can be used in any of emulsion type, solvent type and solventless type.

  (Formation of Release Layer) The release layer is formed by applying a coating liquid in which a release layer component is dispersed and / or dissolved on one surface of a release film base film, followed by heating and drying and / or curing. As a coating method of the coating liquid, a known and arbitrary coating method can be applied, and examples thereof include roll coating, gravure coating, and spray coating. Moreover, you may form a release layer in the whole surface or a part of at least single side | surface of a base film as needed.

  (Peeling force) The peeling force of the release layer is preferably about 1 to 2000 mN / cm and more preferably 100 to 1000 mN / cm with respect to the pressure-sensitive adhesive tape. When the release force of the release layer is less than 1 mN / cm, the release force from the pressure-sensitive adhesive sheet or the material to be bonded is weak, and it peels off or partially floats. Moreover, when larger than 2000 mN / cm, the peeling force of a release layer is strong and it is hard to peel. From the viewpoint of stable releasability and workability, addition and / or polycondensation-type curable silicone resins for release paper, which are mainly composed of polydimethylsiloxane, are preferred.

  (Adhesive layer) The adhesive layer 13 includes an acrylic resin having adhesiveness, an epoxy resin mainly having adhesiveness to an adherend, and a curing agent that reacts with these resins. It can be set as the adhesive sheet 1 which has both adhesiveness and adhesiveness.

  (Epoxy) Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A epoxy resin and bisphenol F epoxy resin, novolac type epoxy resins such as novolac epoxy resin and cresol novolac epoxy resin, biphenyl type epoxy resin, and stilbene type. Examples include epoxy resins such as epoxy resins, triphenolmethane type epoxy resins, alkyl-modified triphenolmethane type epoxy resins, triazine nucleus-containing epoxy resins, dicyclopentadiene-modified phenol type epoxy resins, and also phenol novolac resins and cresol novolak resins. , Novolak type phenolic resin such as bisphenol A novolac resin, phenolic resin such as resol phenolic resin, urea (urea) resin, melamine resin, etc. Resins having a triazine ring, unsaturated polyester resins, bismaleimide resins, polyurethane resins, diallyl phthalate resins, silicon resins, resins having a benzoxazine ring, cyanate ester resins can be exemplified.

  From these resins, it is preferable to include at least a relatively soft epoxy resin and a hard epoxy resin. Here, “soft” and “hard” are relative comparisons, and a soft or hard material having a difference in hardness may be used.

  (Hard epoxy) As the hard epoxy resin, a crystalline epoxy resin is preferable, and a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, and a stilbene skeleton has a main chain and a relatively low molecular weight. Preferably, for example, bisphenol type epoxy resins such as bisphenol A epoxy resin and bisphenol F epoxy resin, and bisphenol A type epoxy resins are particularly preferable. A bisphenol A type epoxy resin having a main chain of 1 to 3 is liquid at normal temperature, and a bisphenol A type epoxy resin having a main chain of 2 to 10 is solid at normal temperature. Among the crystalline epoxy resins, those that are crystallized and solid at room temperature also rapidly melt and change to a low-viscosity liquid when the temperature reaches the melting point or higher, so that the adhesive portion of the adhesive layer 13 is covered. It is possible to increase the adhesive strength by closely adhering to the back surface of the adherend in the initial stage and further adhering. A hard epoxy resin has a high crosslink density, and therefore has high mechanical strength, good chemical resistance, high curability, and low hygroscopicity (because the free volume is small).

  As the hard epoxy resin, a bisphenol A type epoxy resin is preferable, but it is more preferable to use a plurality of different hardnesses. Examples of the plural include ones having different numbers of main chains of a bisphenol skeleton having a rigid structure. For example, a bisphenol A type epoxy resin having a main chain of 1 to 3 and a bisphenol A type epoxy having a main chain of 2 to 10 What is necessary is just to use resin together. By using together, since some softness | flexibility can be obtained, maintaining mechanical strength, it is excellent in adhesiveness. By mixing solid epoxy, the film forming property can be improved. Here, the difference in hardness is a relative comparison, and it is sufficient if there is a difference in hardness, and a harder one or a harder one may be used. Specifically, as a bisphenol A type epoxy resin having a main chain of 1 to 3, manufactured by Japan Epoxy Resin Co., Ltd., JER828 is used as a bisphenol A type epoxy resin having a main chain of 2 to 10 manufactured by Japan Epoxy Resin Co., Ltd. JER1001 etc. can be illustrated.

  (Soft Epoxy) As the soft epoxy resin, an epoxy resin modified to include a rubber component is preferable. In particular, NBR (nitrile butadiene rubber) -modified epoxy resin is preferable because it is less likely to discolor due to heating and is easily mixed with a crystalline epoxy resin that is a hard epoxy resin. Specific examples include EPR4030 manufactured by ADEKA. In order to follow dimensional changes due to thermal expansion of the adherend, it is excellent in terms of improved heat resistance, impact resistance and flexibility.

  The (acrylic) acrylic resin is not particularly limited as long as it has adhesiveness. For example, in addition to a polymer obtained by polymerizing acrylic acid, methacrylic acid and ester monomers thereof, non-polymerizable with the above monomers. A copolymer obtained by copolymerizing a saturated monomer (for example, vinyl acetate, styrene, acrylonitrile, etc.) can be used. As the acrylic resin, an acrylate copolymer is preferable, and a copolymer having at least one of acrylic acid, acrylic acid ester, methacrylic acid ester, and acrylonitrile as a monomer component is exemplified. Among these, an acrylate copolymer having a compound having an epoxy group, a hydroxyl group, a carboxyl group, a nitrile group, or the like as a functional group is preferable. Thereby, the adhesiveness to a to-be-adhered body improves more. Specific examples include SG-P3 manufactured by Nagase ChemteX Corporation.

  Particularly preferably, the acrylic resin is an acrylic ester copolymer formed by radical polymerization of a monomer having EA-BA-AN (ethyl acrylate-butyl acrylate-acrylonitrile), In addition, it is possible to improve applicability and film formability when forming the adhesive layer 11. Moreover, it is possible to ensure the initial tackiness of the adhesive layer 11.

  The weight average molecular weight of the acrylate copolymer is not particularly limited, but is preferably 100,000 or more, particularly preferably 150,000 to 1,000,000, and application of the adhesive layer 11 when the weight average molecular weight is within this range. Improves. In order to increase the cohesive strength, a rosin resin, a terpene resin, a coumarone resin, a phenol resin, a tackifier such as an aliphatic or aromatic petroleum resin, and the like may be added.

(Curing agent) Examples of the curing agent include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and metaxylylene diamine (MXDA), diaminodiphenylmethane (DDM), and m-phenylenediamine (MPDA). In addition to aromatic polyamines such as diaminodiphenylsulfone (DDS), amine-based curing agents such as polyamine compounds including dicyandiamide (DICY) and organic acid dihydralazide, hexahydrophthalic anhydride (HHPA), methyltetrahydrophthalic anhydride (MTHPA) Acid anhydride such as alicyclic acid anhydride (liquid acid anhydride), trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), benzophenone tetracarboxylic acid (BTDA), etc. Physical curing agent, Phenolic curing agent such as Nord resin can be exemplified.
In particular, dicyandiamide (DICY) is a latent curing agent, and thus is excellent in storage stability and has a pot life of several weeks even at room temperature storage. Moreover, you may include imidazoles as a hardening accelerator.

  (Additives) Further, the adhesive 13 may be processed, for example, in terms of workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, difficulty. For the purpose of improving and modifying flammability, antifungal properties, electrical properties, strength, etc., for example, lubricants, plasticizers, fillers, fillers, antistatic agents, antiblocking agents, crosslinking agents, antioxidants UV absorbers, light stabilizers, colorants such as dyes and pigments, and the like may be added. Further, if necessary, a coupling agent such as silane, titanium, and aluminum can be further included. Thereby, the adhesiveness between the resin, the adherend, and the resin and the core material to be described later can be improved.

  (Sea Island) The adhesive 13 is mainly composed of an acrylic resin and an epoxy resin, but a sea island structure is preferable. It is preferable that the acrylic resin is in a sea state and the epoxy resin is in an island state in the sea. Although epoxy resin consists of multiple types, it is presumed to be in a compatible state. With this preferable structure, it is presumed that the sea state of the acrylic resin develops initial tackiness, and the island-shaped poxy resin comes into contact with and adheres to the adherend by pressure heating. Further, the dispersed state is preferable because a certain distance (several μm) at which the sea and the islands do not come into contact with each other can be avoided, and the interface strength can be kept high.

  (Blend ratio) The adhesive 13 is composed of an acrylic resin, a hard epoxy resin, and a soft epoxy resin, and the blend ratio is acrylic resin: hard epoxy resin: soft epoxy resin: curing agent = 100: 75 to 175: 10 to about 100: 2 to 20, preferably acrylic resin: hard epoxy resin: soft epoxy resin = 100: 100 to 150: 25 to 75: 5 to 10. In addition, when using two or more hard epoxy resins, it is set as the sum total. If the hard epoxy resin and the soft epoxy resin are less than this range with respect to the acrylic ester copolymer, the adhesive strength is too strong, resulting in defects when work needs to be replaced or reduced workability. In other words, the adhesive strength with the adherend is reduced. Above this range, the adhesive strength with the adherend is improved, but the adhesive strength is low, and temporary fixing is required and workability is reduced. Moreover, when the compounding ratio of the curing agent is less than this range, the heat resistance after joining is low, and the adhesive strength is likely to deteriorate due to a temperature change. Above this range, the adhesive sheet 1 is stored until it is bonded to the adherend, but the shelf life of that period is lowered, and the unreacted curing agent remains, resulting in a problem that the adhesive strength is reduced. There is also a point.

  (Core material) The core material 15 may be included in the adhesive layer 11 and the adhesive material 13 may be impregnated into the core material. The core material 15 is preferably a woven fabric or a non-woven fabric. The material of the woven or non-woven fabric is not particularly limited, and examples thereof include heat-resistant plastic fibers such as liquid crystal polymers, glass fibers, aramid fibers, and carbon fibers. Cloth and non-woven fabric can be used.

  (Manufacturing method) The present invention comprises the first release paper 21A, the adhesive layer 11 formed by impregnating the core material 15 with the adhesive 13 and the second release paper 21B, and the adhesive is acrylic. It is the manufacturing method of the adhesive sheet | seat which has a tackiness and adhesiveness including a resin and an epoxy resin, and a hardening | curing agent. That is, the core material 15 is overlapped on the release layer surface of the first release paper 21A, the adhesive 13 is applied to the surface of the core material 15, and then the release layer surface of the second release paper 21B is overlapped. By pressing and winding, an adhesive sheet 1 as shown in FIG. 1 can be obtained.

  (Process) Specifically, it can be performed by an existing and known coating machine as shown in FIG. The method for producing an adhesive sheet is as follows: the core material 15 is stacked on the release layer surface of the first release paper 21A, the adhesive agent 13 is applied to the surface of the core material 15, and if necessary, dried. FIG. 2A shows a state where the release layer surfaces of the two release papers 21B are overlapped. Furthermore, the state is as shown in FIG. 2B by heating and pressurizing as necessary. The applied adhesive 13 is impregnated into the core material 15 by heating and pressing as necessary, and the adhesive sheet 1 in FIG. 2B can be obtained.

  First, the adhesive 13 composition for forming the adhesive layer 11 is produced. When using multiple types as a hard epoxy resin using a stirrer, first mix and stir, then mix and stir the curing agent, dilute with a solvent, mix and stir the soft epoxy resin, and then acrylic The system resin was mixed and stirred to obtain an adhesive 13 composition. The stirrer for producing the adhesive 13 composition may be prepared by mixing desired materials, kneading and dispersing as necessary, and is not particularly limited. Conventional kneading and dispersing machines such as two-roll mills, three-roll mills, pebble mills, tron mills, Szegvari attritors, high-speed impeller dispersers, high-speed stone mills, high-speed impact mills, despers, high-speed mixers, ribbon blenders, and kneaders Intensive mixers, tumblers, blenders, dispersers, homogenizers, ultrasonic dispersers, and the like can be applied.

  (Application) Next, the core material 15 is stacked on the release layer surface of the first release paper 21 </ b> A by using a coating method, and the adhesive 13 is applied to the surface of the core material 15. Coating method is not particularly limited, for example, roll coat, reverse roll coat, transfer roll coat, gravure coat, gravure reverse coat, comma coat, rod coat, blade coat, bar coat, wire bar coat, Die coat, lip coat, dip coat, etc. can be applied.

  For example, while the first release paper 21A and the core material 15 are overlapped and run between a comma cylinder and an impression cylinder with a comma coater as shown in FIG. Adjust the distance and viscosity between the comma cylinder and the impression cylinder, apply a desired amount, dry as necessary, overlap the release layer surface of the second release paper 21B, and further if necessary By applying heat and pressure, the adhesive layer 11 can be formed by impregnating the applied adhesive 13 into the core material 15 with less air bubbles, and can be wound up with existing equipment, It can be manufactured at low cost.

  The viscosity of the adhesive 13 composition (coating liquid) at the time of application is about 1 to 20000 centistokes (25 ° C.), preferably 1 to 200 centistokes, and more preferably 1 to 50 centistokes. The core material 15 can be more easily impregnated, and the number of bubbles that can be held in the coating can be reduced.

  In addition, a laminated body in which the adhesive 13 is applied to the release layer surface of the first release paper 21A in advance is prepared, and the blade 15 is moved while the core material 15 is run over the adhesive 13. The adhesive 13 that has been dammed up by adjusting the distance and the viscosity between the comma cylinder and the impression cylinder, applying a desired amount, drying as necessary, and releasing the second release paper 21B Since the adhesive 13 applied on both surfaces of the core material 15 is more effectively impregnated into the core material 15 by stacking the layer surfaces and further applying heat and pressure as necessary, air bubbles to be embraced A small amount of the adhesive layer 11 can be formed.

  In addition, auxiliary heating means such as mechanical vibration, ultrasonic vibration, and deaeration may be used in combination when heating and pressurizing as necessary.

(Adhesion method) Bonding with an adherend peels and removes the first release paper 21A and the second release paper 21B of the adhesive sheet 1 to expose the adhesive layer 11. The exposed adhesive layer 11 is sandwiched between two identical or different first adherends and second adherends, and is held by the adhesiveness of the adhesive layer 11.
Next, the adhesive layer 11 can be cured by heating or pressurizing to firmly bond the first adherend and the second adherend. The heating temperature in this case is about 100 to 300 ° C, preferably 150 to 250 ° C. The heating time is 1 to 240 minutes, preferably 10 to 60 minutes. Since the adhesive layer 11 of the cured adhesive sheet 1 has initial tackiness, there is no preheating step, and the work can be performed while holding the adherend only with the adhesive force, so that the workability is good and low. It is also a cost.

  Further, by selecting the material of the adhesive layer 11 and the blending ratio thereof, the metals, the metal and the organic material, and the organic material and the organic material can be bonded. Furthermore, strong adhesive strength resulting from the epoxy resin is obtained, and this adhesive strength is not easily deteriorated even by temperature change, and because it is attributed to the acrylic resin, the brittleness is low, and excellent shear strength and high resistance to resistance are obtained. Since it has impact and heat resistance, it can be used for structural purposes.

  (Adherent) Examples of the adherend include metals, inorganic materials, organic materials, composite materials combining these materials, and laminated materials.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, each composition of each layer is the mass part of solid content except a solvent.
Further, the bisphenol A type epoxy resin (main chain 1 to 3) is referred to as EPX-1, the bisphenol A type epoxy resin (main chain 2 to 10) is referred to as EPX-2, and the NBR modified epoxy resin is referred to as EPX-3.

Example 1 The following raw materials were mixed with a stirrer to prepare an adhesive 13 composition.
-Acrylic ester copolymer 100 parts-EPX-1 50 parts-EPX-2 100 parts-EPX-3 50 parts-Dicyandiamide 7 parts As the release paper 21A (Separ film SP-PET03BU manufactured by Tohello), the core 15 A liquid crystal polymer nonwoven fabric having a basis weight of 5.9 g / m ² was used.
With the comma coater of FIG. 3, the materials are pulled out in this order from the winding of the first release paper 21A and the winding of the core material 15, and the adhesive is dammed by the blades while running in piles. The adhesive 13 is applied so that the distance between the comma cylinder and the impression cylinder and the viscosity are adjusted so that the coating amount after drying is 50 g / m ² , dried, and then the release layer surface of the second release paper 21B. The pressure-sensitive adhesive sheet 1 was obtained by pressing and rolling with a roll having a temperature of 40 ° C.
The viscosity of the adhesive 13 composition was 3000 cps, the drying temperature was sequentially raised from 50 ° C. to 90 ° C., and the running speed was 12 m / min.

  (Example 2) The adhesive 13 composition was carried out in the same manner as in Example 1 except that the composition was diluted with a solvent to give a viscosity of 50 cps.

  (Evaluation) <Measurement Method of Adhesive Strength> The adhesive sheet 1 produced in Example 1 was cut into 25 mm × 12.5 mm, the release paper 21A was peeled off and removed, and a CFRP substrate ( Affixed to the tip of length 100 mm × width 25 mm × thickness 1.5 mm, and then release paper 21B is peeled off and removed, and CFRP substrate (length 100 mm × width 25 mm × thickness) as another adherend 1.5 mm) was attached to the tip, and 3 kg of weight was placed on the top, and heat cured at 180 ° C. for 1 hour to obtain a laminate, which was used as a test piece. Both ends of this evaluation sample were fixed to Tensilon (Orientec RTA-1T), pulled at 0.5 mm / min, and the shear strength was measured. As a result, it was as good as 15.60 MPa.

<Method for Measuring Initial Adhesive Strength> An adhesive sheet that was allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH was cut into a width of 25 mm and a length of 250 mm to obtain a test sample. Thereafter, the upper release film of the adhesive sheet sample is peeled off and placed on the cleaned glass plate so that the adhesive surface is in contact. From there, it was pasted with a manual crimping apparatus (JIS0237), with a crimping speed of about 5 mm / sec, one reciprocation.
One of the adhered test pieces was peeled off at a speed of 300 mm / min with Tensilon (Orientec RTC1310A), and the stress at that time was taken as the adhesive strength. It was. .

  <Thermal cycle properties> The adhesive sheet 1 produced in Example 1 was allowed to stand at −40 ° C. for 30 minutes and then at + 150 ° C. for 30 minutes using a laminate obtained by laminating two CFRP substrates. Even after 500 cycles as one cycle, the adhesive strength did not decrease and was satisfactory.

(Industrial Applicability) The main use of the adhesive sheet produced by the method for producing an adhesive sheet of the present invention is that FRP of glass fiber or carbon fiber, which is difficult by conventional welding methods, A material (adhered body) such as metal can be strongly bonded, and it is a member related to a transport device such as an automobile.
However, even if it is an adhesive layer formed by impregnating the adhesive into the core material, there are few bubbles to be embraced in manufacturing, and it can be manufactured at a low cost by using a winding method with existing equipment If it is, it will not specifically limit.

1: Adhesive sheet 11: Adhesive layer 13: Adhesive 15: Core material 21: Release paper 21A: First release paper 21B: Second release paper 31A: First laminate 31B: Second laminate

Claims (3)

  The first release paper, the adhesive layer formed by impregnating the core material with the adhesive, and the second release paper, the adhesive includes an acrylic resin, an epoxy resin, and a curing agent, A method for producing an adhesive sheet having both adhesiveness and adhesiveness, wherein the core material is stacked on the release layer surface of the first release paper, and the adhesive agent is applied to the core material surface, A method for producing an adhesive sheet, wherein the release layer surface of the second release paper is overlapped and wound under pressure. The acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN,
The epoxy resin is composed of an NBR (nitrile butadiene rubber) -modified epoxy resin and a bis-A type epoxy resin,
The pressure-sensitive adhesive sheet according to claim 1, wherein the curing agent is a dicyandiamide-based compound.   The method for producing an adhesive sheet according to any one of claims 1 to 2, wherein the adhesive is an acrylic resin and an epoxy resin having a sea-island structure.

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