TW201247413A - Release film bonded double-sided adhesive sheet and process for producing the same - Google Patents

Abstract

A releasable film bonded double-sided adhesive sheet and a manufacturing method thereof are provided to prevent interruption of solidification reaction due to ultraviolet irradiation even if the thickness of the adhesive layer is thick. A releasable film bonded double-sided adhesive sheet is formed by welding releasable films on both sides of the double coated sheet which includes a hardening material of UV-curable adhesive. The releasable film has a releasable layer on the surface of the junction of the base film which includes a resin. A resin which constitutes one or more of the base films among the releasable films is a polyolefin resin. The polyolefin resin which constitutes the base film is a polypropylene based resin.

Description

201247413 VI. Description of the Invention [Technical Field] The present invention relates to a release film-bonding double-sided adhesive tape and a method of manufacturing the same. The release film-bonding double-sided adhesive tape is a release film which is bonded to both surfaces of a double-sided adhesive tape comprising a cured product of an ultraviolet-curable adhesive. The release film-bonding double-sided adhesive tape exhibits good adhesive properties even when the thickness of the adhesive layer is thick, and is particularly suitable for use in the subsequent step of the optical member. The above-described production method is a simple method for simplifying the curing step (ultraviolet irradiation step) of the ultraviolet curable adhesive for bonding the release film to the double-sided adhesive tape. [Prior Art] In industrial use, especially for personal computers, hard disks, etc. Among the optical related applications of electronic devices, liquid crystal displays, touch panels, and the like, double-sided adhesive tapes are widely used for the subsequent attachment of the respective members. The above double-sided adhesive tape is usually supplied by a double-sided adhesive tape which is a release film composed of a double-sided adhesive tape and a release film adhered to both surfaces thereof. This release film is bonded to the double-sided adhesive tape in addition to having a shape in which the adhesive body is bonded before use, and the peeling film on both sides is peeled off. The release film-bonding double-sided adhesive tape is formed by, for example, applying a composition for forming an adhesive to the release surface of the one-side release film, and then curing the coating film into an adhesive layer by heat or ultraviolet rays, and then on the opposite side. After the release film is bonded, it is produced by a step of winding into a roller shape (Japanese Patent Laid-Open Publication No. Hei. No. 201 0-7247 1). -5- 201247413 When a double-sided adhesive tape is attached using a release film, for example, in the case of a liquid crystal display unit and a casing of a liquid crystal display, the release film is bonded to the double-sided adhesive tape and the outer frame shape of the liquid crystal display unit is pressed. To use. On the other hand, in the case of a touch panel, in addition to the purpose of providing a cushioning property between the transparent conductive film (for example, a film of ITO) and the outermost layer of a scratch-resistant film (for example, a PET film), An example of using a double-sided adhesive film. At this time, the display area of the touch panel is entirely covered with a release film to cover the double-sided adhesive tape. The demand for double-sided adhesive tapes in the liquid crystal related field as described above has gradually increased in recent years. In particular, the use of touch panels has been significantly expanded. The screen size of the touch panel is increasing year by year. In the above-mentioned large-sized touch panel, since the cushioning property is required between the transparent conductive film and the scratch-resistant film, the thickness of the double-sided adhesive tape (adhesive layer) tends to be thicker. For this reason, since the thickness of the application can be limited by one application step, when the thickness of the adhesive is increased, a plurality of application steps must be performed. Further, there is a case where it is difficult to completely cure the thickness of the adhesive layer after application. In order to completely cure the adhesive layer, it is necessary to adjust the heating temperature and heating time in the case of a thermosetting adhesive. On the other hand, in the case of an ultraviolet curable adhesive, it is necessary to perform a plurality of ultraviolet irradiation steps, so that the adhesive layer forming step is complicated and the cost is problematic. The release film is bonded to the base material of the release film of the double-sided adhesive tape, and a polyethylene terephthalate (PET) film is suitably used from the viewpoint of heat resistance and surface smoothness. Stripping using a thermosetting adhesive layer with a PET film

-6 - 201247413 In the case where the film is bonded to the release film of the double-sided adhesive tape, it is particularly preferable to reduce the deformation of the base film in the thermal curing step of the adhesive layer as much as possible. However, when the PET film is used as a release film having a peeling film of an ultraviolet curable adhesive layer and a double-sided adhesive tape, there is a problem in the curing step of the adhesive. That is, since PET has a property of absorbing ultraviolet rays having a wavelength of 300 nm or less, ultraviolet curing of the adhesive is hindered. In particular, when the thickness of the adhesive layer becomes thicker, there is a case where the curing reaction of the adhesive layer cannot be completed by one ultraviolet irradiation step. In the above case, for example, a method of delaying the irradiation speed of the ultraviolet irradiation line to increase the irradiation time, a method of performing the ultraviolet irradiation step after the ultraviolet irradiation step, and a method of performing the ultraviolet irradiation step again after the ultraviolet irradiation step; After the release film is bonded to both sides, the release film of the opposite surface is peeled off, and the surface is again subjected to ultraviolet irradiation to expect complete curing. Any of these methods will increase the step time, and the operation is complicated, and the cost is not ideal. However, when the double-sided adhesive tape is bonded by a release film, the peeling film which peels a single surface is used, and the peeling film which peels a single surface after peeling after adhering to an adhering body is used, but the peeling film of the peeling film is peeled. The surface of the adhesive remaining is not constant, or there may be cases where the adhesive layer is damaged. In view of the above, Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. However, in this method, it is necessary to carry out the application step and the curing step of the adhesive layer in two stages, and there is a case where the foreign matter is mixed between the adhesive layers or the interlayer unevenness or the like causes the optical property to be not good at 201247413. As described above, it is possible to suitably apply a double-sided adhesive tape to a release film for use in an optical component, and in particular, a release film-bonded double-sided adhesive tape having a thick ultraviolet-curable adhesive layer and a method for producing the same It has not been proposed in the past. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a release film-bonding double formed by laminating a release film on both surfaces of a double-sided adhesive tape comprising a cured product of an ultraviolet-curable adhesive. In the surface adhesive tape, it is shown that even when the thickness of the adhesive layer is thick, it does not cause good adhesion characteristics due to ultraviolet irradiation and hinders the curing reaction, and can be suitably applied to a release film for optical use, and a double-sided adhesive tape can be attached and manufactured. According to the present invention, the above objects and advantages of the present invention are the first ones of the double-sided adhesive tape formed of a cured product of an ultraviolet curable adhesive. In the film, the release film has a release layer on the surface of the base surface of the base film formed of the resin, and at least one of the release films bonded to both surfaces of the double-sided adhesive tape The resin is a release film of a polyolefin resin and is bonded to a double-sided adhesive. The above object and advantages of the present invention, and a second method for producing the above-mentioned release film bonded double-sided adhesive tape, according to the above polyolefin resin

-8-201247413 A first release film having a release layer on a base film; an ultraviolet-curable adhesive layer; and a second release film having a release layer on a base film formed of a resin, which are laminated in a layered manner, and It is achieved by the above-described method characterized by an ultraviolet irradiation step of irradiating ultraviolet rays on at least the first release film side with respect to the above laminated body. [Embodiment] The release film-bonding double-sided adhesive tape of the present invention is formed by laminating a release film on both surfaces of a double-sided adhesive tape comprising a cured product of an ultraviolet-curable adhesive. Each of the two release films has a release layer on the surface of the base film of the resin on the bonding surface side. In the present specification, the "adhesive layer" of the "cured material of the ultraviolet curable adhesive" is a "double-sided adhesive tape". In the present specification, the three terms are used separately for the sake of simplicity, but the same means the same. Although the release film is attached to both sides of the double-sided adhesive tape, the "release film is attached to the double-sided adhesive tape" in the present specification. Hereinafter, each portion of the release film-attached double-sided adhesive tape constituting the present invention will be described in order. <Substrate film> The base film of the release film of the present invention is composed of a resin. [Resin constituting the base film] The release film of the present invention is bonded to the double-sided adhesive tape, and the release film has -9 - 201247413 2 sheets, but one of the base film is composed of a polyolefin resin. The polyolefin resin of the base film of the invention may, for example, be a homopolymer of ethylene, a homopolymer of propylene, a copolymer of ethylene and another olefin, a copolymer of propylene with another olefin, or a mixture thereof. The above-mentioned olefin is preferably an α-olefin having 4 or more carbon atoms, and specific examples thereof include, for example, butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 1-oxime. It is preferred to use one or more selected from the group consisting of olefin, 1-anthracene, and 4-methyl-1-pentene. The polyolefin resin is one or more kinds of polyethylene resins selected from high density polyethylene resin (HDPE), low density polyethylene resin (LDPE), and linear low density polyethylene (LLDPE), or homopolymerization of propylene. And a polypropylene-based resin selected from the group consisting of a copolymer of propylene and another α-olefin, or a mixture thereof, or a polypropylene-based resin or a polypropylene-based resin. A mixture with a polyethylene resin is preferred. The above polypropylene-based resin is preferably a melt flow rate (MFR) of from 1 to 30 g/10 min based on JIS Κ 7210 at 23 ° C, and more preferably from 3 to 10 g/10 min. The melting point of the polypropylene resin is preferably 125 ° C or more, and more preferably 1 2 5 to 165 ° C. From the above viewpoints, the copolymer ratio of the other α-olefin of the polypropylene resin is preferably 30% by weight or less and 20% by weight or less based on the total weight of the polypropylene as the monomer and the other α-olefin. Better. The above-mentioned polypropylene-based resin, especially a homopolymer of polypropylene, is most suitable because it is easy to find high transparency and high heat resistance, and it has few fish eyes when it is used as a film.

-10- 201247413 When a polyolefin resin of a base film of the present invention is blended with a polypropylene resin and a polyethylene resin, the proportion of the polyethylene is preferably 40% by weight based on the total weight of the two. Hereinafter, it is preferable from the viewpoint of high heat resistance and a film. The release film-attached double-sided adhesive tape of the present invention is present in two, and at least one of the base film is formed by the above-mentioned polymerization. The base film of the other release film may be a resin other than the polyolefin resin which is formed by the above-described resin or may be a resin other than the above-mentioned resin, and it is preferable to use a conventional release film base film material. For example, PET, polyethylene terephthalate, and the like. In the double-sided adhesive tape of the present invention, the resin constituting the base film of the film is a polyolefin resin, but the curing step of the line-illuminated adhesive layer can be performed from the front or the back of the film. The point on which the two sides are advanced is preferably. The base film of the release film on both the front and back sides may be composed of the same kind of resin, or at least one piece of the polypropylene resin may be preferably formed from the viewpoint that the above-mentioned advantages are more effectively found in different types of polyolefin resin structures, or It is preferable that the two sheets of the back of the watch are made of a resin. [Colorant] The release film-bonding double-sided adhesive tape of the present invention is used as a constituent resin as described later, and more preferably, the polyolefin resin of the olefin resin for reducing the fish-eye release film is used therein. The peeling of the diol ester and the poly front and back used is a polyolefin which is carried out on either side of the ultraviolet. However, it is preferable that the peeling force of the release film of the above-mentioned polypropylene-coated double-sided adhesive -11 - 201247413 is different from the front and back. At this time, in order to easily discriminate the release film and the front and back of the double-sided adhesive tape, it is preferable that at least one of the release films of the front and back is a colored film. A method of coloring the release film, for example, a method of applying a printing to obtain a colored film on the surface of a substrate film is known. However, according to this method, in the film formation and other steps, there are a plurality of steps necessary for printing, which results in poor economics. Further, in the step of applying a release agent to the base film (described later), an organic solvent is usually used, and the ink printed on the surface of the base film is dissolved in the organic solvent. Further, it is technically difficult to print thin and uniform on the surface of the film, and there is a possibility that printing unevenness is high. Therefore, it is not suitable for use in which optical inspection is required in a state in which the peeling film is unilaterally left. Another method for coloring the release film proposes that, in the production of the biaxially stretched resin film, the application of the application liquid containing the coloring agent on the film after the longitudinal stretching is performed, and then drying is carried out in the lateral direction, and a non-printing unevenness is obtained in one step. A method of color film (Japanese Patent Laid-Open Publication No. 2000-25108). However, according to this technique, there is still a problem that the surface printing ink is dissolved in the organic solvent and cannot be solved. On the other hand, the method of blending the colorant with the resin constituting the base film does not cause uneven coloration, and the problem that the printing ink is dissolved in the organic solvent when the release agent is applied to the base film is not easily obtained. Colored release film>> The coloring agent used in the present invention is preferably a pigment from the viewpoint of having a small problem of discoloration. The pigment here is in organic pigments and inorganic pigments.

-12- 201247413, it can be appropriately selected as a coloring agent for plastics. In the above-mentioned organic pigment, for example, an azo pigment material, an aniline pigment, a quinacridone pigment, or the like, an inorganic pigmented titanium, a red iron oxide, a ultramarine blue, a carbon black, a cobalt oxide, or the like may be used, and one or more of them may be used. . Among these pigments, in particular, an organic pigment is used, and the secondary coagulum which is removed causes less occurrence of defects such as fish eyes, and the resin has good dispersibility and is suitable. The mixing ratio of the resin coloring agent is determined according to the substrate film, but when considering the transparency as the final release film, it is preferably 0.01 to 5 parts by weight with 0.05 to 3 parts by weight with respect to 100 parts by weight of the resin. . When the mixing ratio is less than 0.01, the hue is unclear, so that it is difficult to adhere the peeling film. On the other hand, when the mixing ratio is more than 5 parts by weight, the transparency (transparency) of the release film is insufficient, and there is a possibility that secondary defects such as fish eyes become conspicuous due to secondary condensation. In addition to sex, it will also cause a large cost burden of coloring agents. The method of blending the resin of the base film constituting the release film, for example, as described above, may be, for example, a method in which a colorant is directly blended on the particles of the resin, and a resin containing a colorant and a colorant is mainly blended with the resin particles. In particular, the method of taking it can be omitted. However, considering the dispersion state of a good coloring agent can reduce the adhesion to the coloring agent of the molding machine, etc., the 1 'phthalocyanine pigment in the master compound is, for example, oxygen from the pigments and due to the thickness Equivalent (transparency) is preferred, and the color of the weight is recognized not only in the case of the coloring agent itself, but also in the method of removing the coloring agent, and the compound is properly used and matched as expected - The method of 13-201247413 is better. [Surface smoothing agent] The release film of the present invention is bonded to the base film ′ of the release film of the double-sided adhesive tape, and its surface smoothness is extremely high. Therefore, the surface of the adhesive layer formed after the step of forming the release layer and the step of laminating the adhesive layer becomes very smooth after the production of the base film. However, in order to obtain the surface of the adhesive layer More highly smooth, the substrate film can also have a smooth surface layer on its surface. When the base film has a smooth surface layer, the base film preferably has a surface smooth layer on at least the side of the peeling layer side, and may have a smooth surface layer on both sides. The surface smoothing layer has a function of burying minute irregularities formed on the surface of the base film to smooth it, but may have other functions. Here, the surface smoothing layer may have other functions such as an intermediate coating function, a hard coat function, an electrostatic prevention function, and the like. The base film has a surface smoothing layer having the above-described electrostatic prevention function, and it is preferable to use a known release film to bond the double-sided adhesive tape to avoid problems caused by static electricity. The thickness of the surface smoothing layer is preferably 0.1 to 5.0 μm, more preferably 0.5 to 3. Ομιη. By setting the thickness of the surface smoothing layer in the above range, it is possible to effectively bury the minute unevenness of the film surface which is caused by crystallization in the production of the base film, and to obtain a high degree of surface smoothness easily and at low cost is 201247413. Characteristics of the material film] The release film of the present invention is bonded to the base film of the release film of the double-sided adhesive tape, and the step of applying the release agent and the step of laminating the ultraviolet-curable adhesive ensure that heat is applied to the substrate film. The tensile elastic modulus is preferably 700 MPa or more in terms of longitudinal and transverse directions, and more preferably 190 Å P a or more, from the viewpoint of dimensional stability of the tension. The thickness of the base film should be appropriately set according to the thickness of the adhesive layer, the area and shape of the product after press working, etc., but it is preferably set to 1 〇 200 μπί, and more preferably 20 to 150 μm, especially 40 °. 120μιη is best. Here, when the thickness of the base film is too thin, the step of applying the release agent and the heat of the step of laminating the adhesive may cause wrinkles due to "heat load" on the film, and may not be used as a product. occasion. Especially in the case where the thickness of the adhesive layer is thick, this tendency is remarkable. On the other hand, when the thickness of the base film is too large, the flexibility is insufficient, and the appearance of defects such as wrinkles and projections is likely to occur at the time of production of the wound body, which is not preferable. [Method for Producing Base Film] The base film of the release film in which the release film of the present invention is bonded to the double-sided adhesive tape is composed of the above-described resin film, and can be produced by any method as long as it has the above characteristics. . The method for producing the base film (resin film) may, for example, be a gas processing method, a casting method, or a method of stretching over a single axis or the like. Among these, the heat shrinkage of the unstretched resin film obtained by the casting method is small, and the step of laminating the release agent -15-201247413 and the step of laminating the adhesive layer cause a small change in the thermal size. The base film of the present invention may have a single layer structure or a multilayer structure. The method in which the base material film has a multilayer structure is, for example, a co-extrusion method represented by a multi-oil sleeve method; an in-line lamination method; and after each layer, a base film is laminated as a colored film through an adhesive layer by dry lamination or the like, The substrate film has a film formed by the stack, and the layer with the colorant is in the outermost state, that is, only the intermediate layer is mixed with the colorant, and the colorant is dissolved in the organic solvent when the adhesive layer is more sure. The problem, or the problem that the coloring agent adheres to the inside of the mold, in particular, when the substrate film has a smooth surface layer, the surface of the resin film formed by the substrate film is coated with a suitable coating agent as the coating agent. Flatten the effect to make. Here, the coating agent may be, for example, a commercially available product of the coating agent, which is commercially available under the trade name of UVH. Technofine. The UVH-D003 has a static electricity prevention function in addition to the function. The viscosity of the coating agent is adjusted to be 1 to 10,000 Å from the viewpoint of the leveling effect. The substrate film of the present invention is applied from the viewpoint of further enhancing and applying the adhesion, and the surface of the coating agent side is applied offline. The surface treatment of the coating which is supplied to the release agent in addition to the surface treatment may, for example, be a corona discharge treatment, a flame heat or the like. The base film has a surface on the surface on which the release agent is applied, and the upper surface treatment is a method in which a smooth layer is applied to the surface smooth layer, which is suitable for a manifold method of two or more layers or a method of manufacturing a single layer. It is particularly preferable that the layer outside the layer of the layer is prevented from being laminated into a molding machine. It is as good as the above, and it is available as a commercial product. D003 (The surface of the light-emitting member is smoothed from the effective discovery of the release agent by wire or smear. The upper (flame) treatment of the smooth layer of the field-16-201247413 < the release agent is applied to the substrate film > The present invention The release film in which the release film is bonded to the double-sided adhesive tape is a release layer obtained by applying a release agent on the one-side surface of the base film as described above. The release agent is not particularly limited to apply the release agent to the base film. For example, a conventional release agent such as a lanthanoid, a fluorine-based or a long-chain alkyl group may be mentioned. The stability of the peeling force and the adhesion to the base film of the present invention are preferably lanthanum-based release agents. The release agent can be exemplified by a thermosetting type ruthenium using a platinum catalyst, an ultraviolet curing type ruthenium using a UV-excited cation generator as a catalyst, etc. A heat curing type ruthenium using a uranium catalyst is composed of at least one An alkyl siloxane having a carbon-carbon double bond; an alkyl oxane having at least one hydrazine-hydrogen bond; and a platinum catalyst. The above heat-curable hydrazine can be used in addition to being generally sold. Type 矽. On the other hand, UV As the line-curable ruthenium, a compound obtained by substituting a benzene nucleus having an epoxy benzene into an alkyl siloxane and a mixture of a UV-excited cation generating catalyst can be used, and a generally widely sold product can be used as the ultraviolet curing type. In the double-sided adhesive tape of the present invention, the peeling force of the release film of the double-sided adhesive tape is preferably different from that of the front and back. The difference of the peeling force of the front and back is set in the release film of the present invention. When the double-sided adhesive tape is used to peel off the release film, the double-sided adhesive tape will not adhere to the release film on the different sides of each region, so that the adhesive layer is destroyed by -17-201247413, so that the double-sided adhesive tape is completely left in the peeling force. The peeling force on one side is preferably one. The difference in peeling force of the back is preferably 2 times or more, more preferably 3 times or more. Especially, the peeling force on the side having a large peeling force is 30 to 500 ( mN/25mm) is better, and 50~3 00 (mN/25mm) is better, and the peeling force of one side with a small peeling force is preferably 1〇~300 (mN/25mm), and 20~100 (mN/25mm) is better, and the difference in peeling force between the two sides is preferably 2 times or more, more preferably 3 times or more. The peeling force can be adjusted by using a release agent applied to the single-base film in combination with the use of the peeling force adjuster. The surface of the release agent after the application of the peeling force adjusting agent "strengthens" the peeling property, that is, the peeling property is formed. A surface which makes peeling of the double-sided adhesive tape more difficult. The peeling force adjuster which can be used herein may, for example, have a SiO 2 unit in an alkyl siloxane, and (CH 3 ) 3 SiO 2 /1 unit or CH 2 = CH (CH 3 ) For the commercially available product of the above-mentioned peeling force adjusting agent, for example, KS-3 800 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. The blending ratio of the peeling force adjuster is relative to peeling. The weight portion of the agent 1 is preferably 1 to 40 parts by weight, and more preferably 5 to 30 parts by weight. Further, the above-mentioned release agent or a mixture of the release agent and the peeling force adjuster is applied to the surface of the base film in a state of ' or appropriately diluted with the solvent. Next, when the release agent is a thermosetting type crucible, when the ultraviolet curing type crucible is heated, the release agent is cured by irradiation with ultraviolet rays, whereby a release agent layer can be formed on the base film.

-18- 201247413 The method of application is not particularly limited, and a conventional method can be used. For example, a coating method by a coating head generally used can be appropriately selected; for example, a printing method based on a gravure, a gravure, a bias, or the like is basically applied: a die of a mold coater is extruded at a predetermined thickness. A method of laminating after coating a film; a method of squeezing a squeegee or a comma squeegee as a basic smear method, and the like is generally applied. The conditions of heating or ultraviolet irradiation can be appropriately set by the type of the release agent to be used and the thickness of the release layer. The thickness of the release agent is not particularly limited, and can be appropriately set in accordance with the peeling force for the release film. The thickness is, for example, 0-0 1 to 0.5 μπι', and the stability of the peeling force is preferably 0.05 to 0.2 μm for the amount of transfer of the back surface. <Ultraviolet-curing adhesive> The double-sided adhesive tape of the release film-attached double-sided adhesive tape of the present invention is formed of a cured product of a UV-curable adhesive. The ultraviolet curable adhesive may, for example, be a UV-curable adhesive of a rubber-based adhesive such as a styrene-butadiene copolymer emulsion or a styrene-isoprene copolymer; or an ultraviolet curable type of an acrylic adhesive; An ultraviolet curing type of an adhesive such as a lanthanum. These ultraviolet curable adhesives are provided, for example, in the form of a solvent system, an aqueous emulsion system, or a hot melt system. The thickness of the adhesive layer is, for example, 5 〇μηι or more, especially when it is thicker than 8 〇μηη, although a hot-melt adhesive is used, but a layer having a thick layer thickness can be formed in one step -19-201247413 ideal. <Method for Producing Release Film-Coated Double-Sided Adhesive Tape> The release film-attached double-sided adhesive tape of the present invention is a first release film having a release layer on a base film formed of a polyolefin resin, The second release film having a release layer on the base film formed of the ultraviolet curable adhesive and the resin is laminated as a laminate, and the laminate is irradiated with ultraviolet rays by ultraviolet rays from at least the first release film side. The steps can be made. The two release films are disposed such that the surface having the release layer is bonded to the adhesive layer. It is preferable that the two release films are provided with different peeling forces as described above, but the peeling force of either of the release films can be improved. When the curing reaction of the adhesive is carried out on the release film by ultraviolet irradiation, the actual peeling force tends to be higher than the original peeling force of the release film. In such a case, the difference in peeling force between the two faces becomes small. In order to avoid this, the first release film is preferably a release film having a high peeling force. The base film of the second release film is preferably a polyolefin resin composition as described above. The thickness of the ultraviolet curable adhesive can be appropriately set in accordance with the use of the release film of the present invention to bond the double-sided adhesive tape. In order to make the peeling film having the base film formed of the polyolefin resin not absorb the characteristic of ultraviolet rays of a specific wavelength, the thickness is maximized. The thickness of the ultraviolet curable adhesive is preferably 20 μm or more, more preferably 50 to 50 μm. And the best with 80~3 00μιη. According to the first release film, the ultraviolet curing adhesive, and the second release film

-20-201247413 A method of laminating the laminated body in the order of, for example, applying a layered ultraviolet curable adhesive to the peeling layer forming surface of one of the first release film and the second release film, and then laminating the other side A method in which the release film is laminated to bond the release layer to the layer of the ultraviolet curable adhesive. The method of applying the ultraviolet curable adhesive layer to the release film in a layered form is not particularly limited, and a conventional method can be appropriately selected and used. The smear method can be, for example, a smear method using a coating head which is generally used; for example, a smear method based on a transfer method such as gravure, gravure, offset, etc.; a mold of a mold coater having a predetermined thickness A method of laminating a film after extrusion; a method of picking with a doctor blade or a comma blade is a general application method such as a basic application method. The layer of the UV curable adhesive that cures to form the double-sided adhesive tape may or may not have a film-like substrate in the layer. However, when the simplification of the manufacturing steps and the maintenance of the optical characteristics of the double-sided adhesive tape are considered, it is preferred that the film-form substrate is not provided. Further, the release film-attached double-sided adhesive tape of the present invention can be obtained by the ultraviolet irradiation step of irradiating ultraviolet rays from the side of the first release film to the laminate. In the case where the base film of the second release film is composed of a polyolefin resin, the irradiation of the ultraviolet rays in the ultraviolet irradiation step may be performed not only from the first release film side but also from both sides. Therefore, according to this state, the irradiation time of the ultraviolet rays can be shortened, and the step time can be further shortened. The conditions of the ultraviolet ray irradiation can be appropriately set according to the type and thickness of the ultraviolet ray-curable adhesive to be used. 21 -21 - 201247413 Hereinafter, the preferred production of the release film-bonding double-sided adhesive tape of the present invention will be described with reference to the drawings. method. Fig. 1 and Fig. 2 are schematic views showing an example of a manufacturing apparatus preferably used in the method of the present invention. The apparatus of the first embodiment has a film supply device that supplies a first release film (a release film having a release layer having a strong peeling force), and a film delivery device that supplies a second release film (a release film having a release layer having a weak release force). A device for supplying an ultraviolet curable adhesive; a cooling roller for cooling an adhesive supplied to the release film: an ultraviolet irradiation device for irradiating ultraviolet rays from both surfaces of the laminate: a winding roller and a plurality of support rollers. The base film of the release film used herein is composed of a polyolefin resin, and the ultraviolet curable adhesive is a hot melt type. A release film having a release layer having a strong peeling force sent from a film feeding device that supplies the first release film is guided onto a cooling roll, and an ultraviolet curable adhesive supplied from the mold is laminated on the release layer. Since the temperature of the mold is set to a temperature at which the ultraviolet curable adhesive has sufficient fluidity, the mold is supplied in a state in which the adhesive has fluidity. The adhesive is subsequently cooled or lost by the cooling roller through the release film, and at the same time or subsequently, on the adhesive layer, the laminate is supplied from the film delivery device that supplies the second release film. The release film of the peeling layer of weak peeling force forms a laminated body. Here, the release film from the film feeding device that supplies the second release film is supplied by bonding the release layer having the release film to the adhesive layer. The obtained laminate was irradiated with ultraviolet rays from both surfaces, and was wound around a winding roller in addition to curing the ultraviolet curable adhesive. S: -22- 201247413 The apparatus of Fig. 2 is a device in which the mold is replaced by a Meyer bar smearing method using a Meyer bar in the apparatus of Fig. 1. The details of the other aspects of the apparatus of Figure 2 should be readily understood by the practitioner. As described above, the release film supplied from the film discharge device that supplies the first release film and the release film supplied from the film discharge device that supplies the second release film can be replaced with each other. Further, ultraviolet irradiation may be performed from only one of them. The method of the present invention as described above is carried out by irradiating ultraviolet rays in a state in which both surfaces of the ultraviolet curable adhesive layer are protected by a release film. According to this state, the time for exposing one side of the ultraviolet curable adhesive layer to the environment at the manufacturing site can be extremely shortened, so that it is extremely possible to reduce the adhesion of foreign matter such as dust in the environment to the adhesive layer as much as possible. ideal. This has a great advantage with respect to the conventional method of using a substrate film in which PET is a release film. That is, according to the conventional method, since the PET constituting the base film absorbs ultraviolet rays, it is necessary to perform ultraviolet irradiation in a state where one side of the adhesive layer is exposed to the environment of the manufacturing site in order to avoid this. Therefore, the conventional method does not eliminate the fear of adhering foreign matter to the adhesive layer even if the dust-free manufacturing site is formed within the usual cost-tolerable range of the film industry. The above-described concerns of the conventional method can be fundamentally solved by the method of the present invention. <Release film-bonding double-sided adhesive tape> The release film-attached double-sided adhesive tape of the present invention obtained as described above shows that even if the thickness of the adhesive layer is thick, it is not caused by ultraviolet rays -23-201247413 Good adhesion properties that hinder the curing reaction. The release film-attached double-sided adhesive tape of the present invention is particularly suitable for use in optical applications. [Examples] Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to the examples. The evaluations of the following examples and comparative examples were carried out by the following procedures. (1) Tensile modulus of elasticity The tensile modulus of elasticity was measured by using an index of the rigidity of the base film of the release film. The measurement device is manufactured by Shimadzu Corporation, AUTOGRAPH (model number: AG-500D), and based on JIS K7127, JIS-5 test piece is used, and the tensile speed is 50 mm/min, respectively, for the MD direction and the TD direction. The measurement was carried out. (2) Peeling force The No. 31B tape manufactured by Nitto Denko Co., Ltd. was pressure-bonded to the peeling surface of the release film by a roller of 5 kg, and the state was adjusted for 24 hours at 231, and then the tape was taken at a speed of 300 mm/min. 180. Peeling, thereby measuring the peeling force. (3) Turbidity The turbidity was measured by adhering the peeling film to the index of the transparency of the double-sided adhesive tape.

-24- 201247413 The measuring device was measured using a SUGA tester (stock) and HAZE-METER (catalog number: HGM-2DP) based on JIS K 7105. (4) Fish eyes and foreign matter The presence or absence of fish eyes and foreign matter present in the double-sided adhesive tape attached to the release film was visually observed. For the fisheye and foreign matter that has been found, the long diameter is measured with a magnifying glass with a minimum unit of 0.1 mm, and the number of sizes of 0.2 mm or more is converted into the number per lm2. (5) When the adhesive is cured, the peeling film of the double-sided adhesive tape is peeled off from the peeling mold, and the corona-treated side of the PET film (E5100#50: manufactured by Toyobo Co., Ltd.) is attached to the adhesive surface. A thin rectangular test piece of 25 mm wide XI 50 mm was made. Then, the release film of this test piece was peeled off, and the test piece was peeled off after being attached to the SUS plate. The condition of the adhesive layer at this time was visually confirmed.

Yes : No adhesive layer damage, all adhesives remain on the pet film side.

No: The adhesion between the adhesive layer and the PET film is low, the adhesive layer is damaged, and the adhesive remains on both the PET film and the SUS plate. (6) Peeling condition The residual state of the adhesive layer when peeling off the release film and the release film of the double-sided adhesive tape (the side having a small peeling force when the peeling force is poor) is visually confirmed.

Yes : No damage to the adhesive layer, all adhesives remain in the side (both sides have a peeling force when the peeling force is poor). -25- 201247413

No : The adhesive layer is damaged, and peeling films on different sides remain in each area. (Example 1) (Production of release film) Using a non-stretched polypropylene film PP-1 (SUN, TOX (product number: R012 #60, thickness 60 μm)) as a base film, a release film was produced by the following method. The corona-treated side of the film was coated with a heat-curable 矽-1 (Shin-Etsu Chemical Co., Ltd., product number: KS-3703) with a gravure roll coater and a peeling force adjuster (Shin-Etsu Chemical Industry) (Stock), product number: KS-38 00) A mixture of 20 parts by weight, and the amount of application was 0.1 g/m2 to obtain a first release film. Different from the above, on the corona-treated side of the base film, a heat-cured sand-2 (manufactured by Dongling Dow-Corning Co., Ltd., product number: LTC7 50A) was applied by a gravure roll coater to form an application amount. 0.1 g/m2, a second release film was obtained. The evaluation of the above (1) and (2) was carried out using these release films. The results of the evaluation are shown in Table 1. (Production of release film-bonding double-sided adhesive tape) The production of the release film-bonded double-sided adhesive tape was carried out using a manufacturing apparatus as shown in Fig. 1. Here, the temperature of the mold for supplying the ultraviolet curable adhesive is 120 ° C, the temperature of the cooling water of the cooling roll of 201247413 is 5 ° C, the winding speed of the belt is 4 m / s, and the amount of ultraviolet rays irradiated is adjusted so that Both the first (first release film side) and the upper surface (second release film side) formed 600 i/m 2 . The first release film obtained above was supplied from the delivery device, and this was guided to a cooling roll, and the ultraviolet curable adhesive HM-1 (manufactured by No-tape Industrial Co., Ltd., product number: UV3 00) is applied to the release layer of the ith release film and is applied to a thickness of 175 μm. Subsequently, the second release film obtained as described above is supplied from the delivery device onto the adhesive layer to form a laminate. Then, ultraviolet rays were irradiated from both sides to the obtained layered body, and the ultraviolet curable adhesive was cured, and then wound around a winding roll, whereby a release film-bonded double-sided adhesive tape was obtained. The above-mentioned (3) to (6) were evaluated by adhering the double-sided adhesive tape to the obtained release film. The results of the evaluation are shown in Table 1. (Example 2) A release film-bonded double-sided adhesive tape was obtained in the same manner as in Example 1 except that the thickness of the UV-curable adhesive ΗΜ-1 applied was 50 μm. The above-mentioned (3) to (6) evaluation was carried out by bonding the double-sided adhesive tape using the release film. The evaluation results are shown in Table 1. Further, in the present embodiment, since the same release film material as in the above-described first embodiment was used, the evaluations of the above (1) and (2) were reproduced by the evaluation results of the first embodiment. -27-201247413 (Example 3) A release film-bonded double-sided adhesive tape was obtained in the same manner as in Example 1 except that the ultraviolet rays were irradiated from the second release film side (upper side), and the release film was adhered to the double-sided adhesive tape. The tape was subjected to the evaluation of the above (3) to (6). The evaluation results are shown in Table 1. Further, in the present embodiment, since the same release film material as in the above-described first embodiment was used, the evaluations of the above (1) and (2) were reproduced by the evaluation results of the first embodiment. (Example 4) The production of the release film-bonding double-sided adhesive tape was carried out using a manufacturing apparatus as shown in Fig. 2 . Here, the application of the ultraviolet curable adhesive is carried out without heating the adhesive, the winding speed of the sheet is 4 m/s, and the amount of ultraviolet light to be irradiated is the upper side (the first peeling film side) and the lower side ( The second release film side) was also adjusted to 600 J/m 2 . Further, NS-1 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product number: NS-001) was used as the ultraviolet curable adhesive, and the thickness of the adhesive was 50 μm, in addition to Meyer's application using a Meyer bar. The above Example 1 was similarly carried out to obtain a release film-bonded double-sided adhesive tape. The double-sided adhesive tape was bonded to the release film to carry out the evaluation of the above (3) to (6). The evaluation results are shown in Table 1. Further, in the present embodiment, since the same release film material as in the above-described first embodiment was used, the evaluations of the above (1) and (2) were reproduced by the evaluation results of the first embodiment. (Example 5)

-28- 201247413 (Manufacturing of release film) A total of 3 extrusions using a single-axis extruder with a screw diameter of 75 mm (for the intermediate layer) and two single-axis extruders with a screw diameter of 50 mm (for both outer layers) Three types of three-layer T-mode film forming apparatuses made of the machine are used for the production of the base film of the i-th release film." Polyethylene resin PE (made by Ube Natsuki Polyethylene Co., Ltd., article number: F522N, density = 9.922g/cm3, melting point = ii〇°c, MFR = 5.0g/10 minutes; at 190 ° C) as the resin for the intermediate layer and the two outer layers of the extruder, and the resin temperature is 250 ° C The residence time was 1 minute, and the T-die temperature was 240 ° C. The polyethylene film was obtained by a 25 ° C cooling roll to obtain a total thickness of 60 μm. Next, a corona discharge treatment was applied to form a wetting index of the surface of the adhesive-side layer on which the film was laminated to 42 mN/m, and at 4 (TC was resistant to aging by 24 hours, a substrate was obtained. The first release film was obtained in the same manner as in the above-mentioned Example 1. The second release film was produced by using PP_丨 as a base film in the same manner as in the above-described Example 1. The above-mentioned release film was used to carry out the above ( Evaluation of 1) and (2). The evaluation results are shown in Table 1. (Production of release film-bonded double-sided adhesive tape) The above-described examples were used in addition to the first and second release films produced as described above. (1) A double-sided adhesive tape with a release film was obtained in the same manner. The double-sided adhesive tape was bonded to the release film, and the evaluation of the above (3) to (6) was carried out. Evaluation -29 - 201247413 The results are shown in Table 1. (Example 6) A release film was obtained in the same manner as in Example 1 except that a base film formed on the first release film was used as the base film of the first release film, which was obtained by using a PET film (manufactured by Toyobo Co., Ltd., product No. E5 100). The evaluation of (1) and (2) above was carried out. The evaluation results are shown in Table 1. A release film-bonding double-sided adhesive tape was obtained in the same manner as in Example 1 except that the first and second release films were used. The double-sided adhesive tape was bonded to the release film to perform the above (3). Evaluation of ~(6). The evaluation results are shown in Table 1. (Example 7) A non-stretch polypropylene film PP-2 (manufactured by SUN·TOX Co., Ltd., article number: MK12#40, thickness 40 μm) was used. A release film was obtained in the same manner as in Example 1 except for the base film of the first release film. The evaluation of the above (1) and (2) was carried out using the release film. The evaluation results are shown in Table 1. In the same manner as in Example 1, except that the release film was used, a release film-bonding double-sided adhesive tape was obtained. The double-sided adhesive tape was bonded to the release film to evaluate the above (3) to (6). The results are shown in Table 1. (Example 8) (Production of release film) The same apparatus as in Example 5 was used for the first release film.

-30- 201247413 Manufacture of substrate film. The average weight of the pp-3 (made by Sumitomo Chemical Co., Ltd., product number: FLX80E4, melting point = 163 ° C, MFR = 7 g / l 〇 minutes; 230 ° C) The resin of the two outer layers of the extruder is mixed with 5 parts by weight of the masterbatch masterbatch (DIC, product number: PEONY HP BLUE L-) with respect to 100 parts by weight of the resin of the extruder supplying the intermediate layer. A base film was obtained in the same manner as in Example 5 except that 83285 M, base resin = polypropylene, and pigment concentration = about 5%. The first release film was obtained in the same manner as in the above Example 1 except that the base film was used. The second release film was produced by using ΡΡ_ι as a substrate film in the same manner as in the above Example. The evaluation of the above (1) and (2) was carried out using these release films. The results of the evaluation are shown in Table 1. (Production of a release film-bonding double-sided adhesive tape) A release film-bonding double-sided adhesive tape was obtained in the same manner as in the above-described Example 1 except for the first and second release films produced as described above. The above-mentioned (3) to (6) evaluation was carried out by bonding the double-sided adhesive tape using the release film. The results of the evaluation are shown in Table 1. (Comparative Example 1) Both the base film used for the first and second release films were made of PET film (manufactured by Toyobo Co., Ltd., product number: E5 100), and the same as the above-mentioned Example 1 - 31 - 201247413 The release film was obtained by the sample. The evaluation of the above ((2) was carried out using the release film. The results of the evaluation are shown in Table 1. Subsequently, a release film-bonding double-sided adhesive tape was obtained in the same manner as in Example 1 except that the release film was used. The double-sided adhesive tape was bonded to the release film, and the evaluation of the above (3) to (6) was carried out. The evaluation results are shown in Table 1. (Comparative Example 2) Both of the base film used for the first and second release films were A release film was obtained in the same manner as in Example 2 except that a PET film (manufactured by Toyobo Co., Ltd., product number: E5 100) was used. The evaluation of the above (1) and (2) was carried out using the release film. The results are shown in Table 1. Then, a release film-bonding double-sided adhesive tape was obtained in the same manner as in Example 1 except that the release film was used. The double-sided adhesive tape was bonded using the release film to carry out the above (3)~ (Evaluation of (6). The evaluation results are shown in Table 1. (Reference Example 1) In the above Comparative Example 1, the double-sided adhesive tape was bonded to the release film which was wound on the winding roller by one-time irradiation of ultraviolet rays, and the following was further carried out as follows. Two times of ultraviolet irradiation. The above-mentioned release film is fed from a roll. In the surface-adhesive tape, the second release film is irradiated with ultraviolet rays from both sides of the sheet, and a new second release film is bonded to the laminate, and the laminate is wound into a laminate. The second release film is peeled off again and ultraviolet rays are irradiated again. By operation, a release film is attached to the double-sided adhesive tape.

-32- 201247413 The above-mentioned (3) to (6) evaluation was carried out by bonding the double-sided adhesive tape using the release film. The evaluation results are shown in Table 1. Further, in the present embodiment, since the same release film material as in Comparative Example 1 was used, the evaluations of the above (1) and (2) were reproduced by the evaluation results of Comparative Example 1. -33- 201247413 Table 1 (1/3) 0 Example 1 Example 2 Case 3 Face 4 mm 莠 Substrate ΡΡ-1 ΡΡ-1 ΡΡ-1 ΡΡ-1 Thickness (wm) 60 60 60 60 Stretching Elastic mold s (MPa) MD 1,200 1, 200 1,200 1, 200 TD 1,200 1, 200 1,200 1, 200 Peel force (mN/25im) 90 90 90 90 mw A cs 肫 substrate ΡΡ -1 ΡΡ-1 ΡΡ-1 ΡΡ"1 Thickness (Mm) 60 60 60 60 Tensile modulus of elasticity (MPa) MD 1,200 1,200 1,200 1, 200 TD 1, 200 1,200 1, 200 1, 200 Peel force (mN/25min) 40 40 40 40 襄蘅榊Type ΗΜ-1 ΗΜ-1 ΗΜ-1 NS-1 Thickness (μπΟ 175 50 175 50 戡铖陛 double sided double sided single side (2nd Side> Double-sided number 1 1 1 1 Turbidity (8) 3 0 3 0 3 0 3 0 Fisheye and foreign matter (pieces/m2) 6 6 6 8 Adhesive curing condition Yes Yes Yes Yes Peeling condition Yes Yes Yes Yes 201247413 1 (2/3) Example 5 Example 6 Example 7 Example 8 m Sub-mu m substrate PE PET PP-2 PP-3 Thickness (Mm) 60 50 40 60 Tensile elastic joint (MPa) MD 500 4 , 000 1,000 1,200 TD 500 4, 000 1,000 1,200 Peel force (mN/25mn) 90 90 90 90 m viewing m substrate PP-1 PP-1 PP-1 PP-1 thickness (μπί) 60 60 60 60 tensile modulus (MPa) MD 1,200 1,200 1,200 1,200 TD 1,200 1, 200 1, 200 1,200 Peel force (πιΝ/25ιηιη) 40 40 40 40 蘅槲mm HM-1 HM-1 HM-1 HM-1 Thickness Um) 175 175 175 175 m Double-sided double-sided double-sided Double-sided number 1 1 1 1 Turbidity (8) 2 5 2 0 2 8 3 2 Fisheye and foreign matter (pieces/m2) 10 5 5 6 Adhesive curing condition Yes Yes Yes Yes Peeling condition Yes Yes Yes Yes -35- 201247413 Table 1 (3/3) Comparative Example 1 Comparative Example 2 Reference Example 1 m Sub-mi substrate PET PET PET Thickness (Mm) 50 50 50 Tensile elastic modulus fi (MPa) MD 4, 000 4, 000 4, 000 TD 4, 000 4, 000 4, 000 Peel force (mN/25mm) 90 90 90 m Following cs substrate PET PET PET Thickness (M in) 50 50 50 Tensile modulus of elasticity (MPa) MD 4, 000 4, 000 4, 000 TD 4, 000 4, 000 4, 000 Peel force (mN/25im) 40 40 40 蘅 蘅 HM-1 HM-1 HM-1 Thickness (wm) 175 50 175 m Double-sided number 1 1 3 Turbidity (8) 10 10 10 Fisheye and foreign matter (pieces/m2) 6 5 10 0 Adhesive [Resolution effect] No Yes Yes Peeling condition No Yes Yes 201247413 [Effect of the invention] The release film of the present invention is bonded to the double-sided adhesive tape, and even if the thickness of the adhesive layer is thick, it is not hindered by the curing reaction by ultraviolet irradiation. Can show good adhesion characteristics. Therefore, the release film-attached double-sided adhesive tape of the present invention is particularly useful for optical applications. The method for producing a release film of the present invention in which a double-sided adhesive tape is bonded can be produced in a simple manner by producing an excellent release film-attached double-sided adhesive tape as described above. In particular, even when the thickness of the adhesive layer is thick, it is possible to carry out the curing step of the adhesive layer which does not require a plurality of ultraviolet rays, and it is possible to inexpensively produce a peeling film having excellent performance and to bond the double-sided adhesive tape. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an example of a preferred manufacturing apparatus for manufacturing a release film bonded double-sided adhesive tape of the present invention. Fig. 2 is a schematic view showing another example of a preferred manufacturing apparatus for producing a double-sided adhesive tape for a release film bonded to the present invention. -37-

Claims (1)

201247413 VII. Patent application scope 1. A release film-bonding double-sided adhesive tape, which is characterized in that a peeling film is bonded to both sides of a double-sided adhesive tape composed of a cured product of an ultraviolet-curable adhesive, and the peeling film is respectively The surface of the base film of the resin has a release layer on the surface on the bonding surface side, and at least the resin of the release film which is bonded to both surfaces of the double-sided adhesive tape is a polyolefin resin. The release film-bonding double-sided adhesive tape according to the first aspect of the invention, wherein the polyolefin resin constituting the base film is a polypropylene resin. The release film-bonding double-sided adhesive tape according to the second aspect of the invention, wherein the base film formed of the polypropylene resin is a non-oriented polypropylene film. 4. The release film-bonding double-sided adhesive tape according to the first aspect of the invention, wherein the resin constituting the release film is a polyolefin resin. A method for producing a double-sided adhesive tape by a release film, which is a method for producing a release film-bonded double-sided adhesive tape according to the first aspect of the invention, which is characterized in that: a first release film having a release layer on a base film; an ultraviolet curable adhesive; and a second release film having a release layer on a base film formed of a resin -38-201247413 A method of manufacturing a fifth layer of the present invention by stacking ultraviolet rays at least from the side of the first release film with respect to the laminate; , wherein, _ is an external line irradiation step of the outer line. The grease is a polyolefin resin, and ultraviolet rays are irradiated from the rain of the laminate in the ultraviolet irradiation step. The peeling film described in the item is bonded to the double-sided adhesive stomach. The tree of the base film of the second peeling film is -39-