JP2013032533A - Method for producing adhesive film, and adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an adhesive film, and to provide the adhesive film, which are excellent in adhesivity of an adhesive agent layer to a base material layer, can reduce the thickness of the base material layer, have no need to contain a lubricant, which reduces optical characteristics such as transparency, in the base material layer, and are excellent in productivity.SOLUTION: A resin layer A for forming an adhesive agent layer to develop adhesivity at normal temperature by energy-ray curing, and a resin layer B for forming a base material layer which is solidified at normal temperature by energy-ray curing without developing adhesivity are coated in a multilayer; and thereafter, energy rays are emitted to simultaneously completely cure the resin layer A and the resin layer B, thereby at one time forming an adhesive film in which the adhesive agent layer is laminated at least on one surface of the base material layer. Since the adhesivity of the adhesive agent to the base material layer is improved, the problem of adhesive residue hardly occurs. Since no problem on production occurs even if the thicknesses of the base material layer and the adhesive agent are freely set, the thickness of the base material layer can be reduced.

Description

  The present invention relates to a method for producing an adhesive film and an adhesive film.

  In general, a pressure-sensitive adhesive film is a base film made of various films provided with a pressure-sensitive adhesive layer made of an acrylic or rubber solvent-type pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, or a hot-melt pressure-sensitive adhesive. As a product form, tape is applied with a separator such as a release film or release paper attached to the adhesive surface, or a release treatment is applied to the back surface of the base film (the surface opposite to the adhesive side). The form is rolled up into a shape. For the production of adhesive films, the adhesive is directly applied to the base film, dried and cured, and then the separator is attached to the surface of the adhesive material. The adhesive is applied to the release surface of the separator, and then the adhesive is dried and cured. And a method in which a substrate film is bonded to the pressure-sensitive adhesive after the pressure-sensitive adhesive is applied to the release-treated surface of the separator, dried and cured.

  In recent years, for example, in the case of adhesive films and protective films for displays, in order to improve yield and reduce costs, if there is a problem with the protective film or panel, the panel and the protective film are separated, and there is no problem. Recycling of protective films or panels has been performed. In addition, when disposing of industrial products, the adhesive film is peeled off from the adherend when disposing of industrial products using adhesive films, because of the requirement to disassemble the products when disposing of industrial products and dispose of the components separately for each type of material. Need to be separated. For this reason, the adhesive film is required to have reworkability, workability for correcting the pasting position, and ease of peeling at the time of disposal. Furthermore, when the adhesive film is peeled off, the adhesive residue (adhesion to the adherend surface) is required. The phenomenon that the agent remains is not required to occur. However, in the pressure-sensitive adhesive film produced by the conventional manufacturing method, the anchoring force of the pressure-sensitive adhesive with respect to the base film is insufficient, and when the pressure-sensitive adhesive force with respect to the adherend is strong, adhesive residue may be generated, which may be a problem.

  On the other hand, regarding the problem of waste, it is also required to reduce the thickness of the base material layer from the viewpoint of volume reduction when the adhesive film becomes waste. However, in the conventional manufacturing method, if the thickness of the base film is reduced, the tension applied to the base film during processing in the adhesive coating / drying apparatus must be weakened, and the base film is wrinkled and kinked. In order to prevent this, it is difficult to apply the adhesive layer thicker than the thickness of the base film. Moreover, in the method of bonding a base film after apply | coating an adhesive on a separator, when the thickness of a base film is thin, there exists a problem that it is easy to produce a wrinkle and a float at the time of bonding of a base film.

  Furthermore, in the method of applying the pressure-sensitive adhesive to the base film, there is a problem that continuous processing cannot be performed unless the base film has a thickness that can be wound around a roll. In addition, the base film itself is added with a lubricant such as kaolin, calcium carbonate, colloidal silica, etc. in order to avoid problems such as wrinkles and scratches due to friction when wound into a roll, such as a catalyst used during resin synthesis, etc. By providing a part of or the entire surface, or by providing a fine particle layer or a coating layer on the surface (see, for example, Patent Documents 1 and 2), the surface of the base film is made slippery and smoothly rolled. I try to wind it up. However, considering the application to the optical field, even if a highly transparent resin is used for the base film itself, if a method such as addition of a lubricant, precipitation of a catalyst, formation of irregularities on the surface is adopted, etc. It is considered that the optical properties (transparency, etc.) of the base film are inferior.

JP-A-5-70612 JP 2003-119305 A

  The present invention has been made in view of the above circumstances, is excellent in adhesiveness of the pressure-sensitive adhesive layer to the base material layer, can be made thin, and has optical properties such as transparency in the base material layer. It is an object of the present invention to provide a pressure-sensitive adhesive film production method and pressure-sensitive adhesive film that are excellent in productivity without the need to include a reducing lubricant.

In order to solve the above-mentioned problems, the present invention provides a resin layer A for forming an adhesive layer that exhibits tackiness at room temperature by energy ray curing, and a base material layer that solidifies without exhibiting tackiness at room temperature by energy ray curing. After the multi-layer coating with the forming resin layer B, the adhesive layer is formed on at least one surface of the base material layer by irradiating energy rays and completely curing the resin layer A and the resin layer B at the same time. Provided is a method for producing a pressure-sensitive adhesive film, wherein a laminated pressure-sensitive adhesive film is formed at a time.
In the manufacturing method of this invention, it is preferable that the said resin layer A and the resin layer B consist of a solventless type energy-beam curable composition. The resin layer A can be multi-layered with at least two resin layers that become an adhesive layer after curing. The resin layer A and the resin layer B can be multilayer coated on the separator.
Moreover, this invention provides the adhesive film by which the adhesive layer was laminated | stacked on the at least one surface of the base material layer characterized by the above-mentioned manufacturing method.
In the pressure-sensitive adhesive film of the present invention, it is preferable that the glass transition point after curing of the base material layer exceeds 20 ° C., and the glass transition point after curing of the pressure-sensitive adhesive layer is 20 ° C. or less.

According to the present invention, the pressure-sensitive adhesive layer and the base material layer are simultaneously polymerized and cured to form the pressure-sensitive adhesive layer and the base material layer at the same time. The effect of.
(1) Adhesiveness is improved by the ease of forming a chemical bond between the base material layer and the adhesive layer, and the anchoring effect of the adhesive layer on the base material layer. Even when affixed to a kimono, the problem of adhesive residue is less likely to occur.
(2) The thickness of the base material layer and the pressure-sensitive adhesive can be freely set, and even if the thickness of the base material layer is reduced, no problem in manufacturing occurs. Therefore, an adhesive film thinner than before can be produced.
(3) Since there is no step of winding the base material layer alone in the manufacturing process, it is not necessary to mix a component for imparting slipperiness such as a lubricant to the base material layer. Therefore, an adhesive film excellent in optical characteristics such as transparency can be produced.

  When a solventless energy ray curable resin composition is used as the resin layer A for forming the adhesive layer and the resin layer B for forming the base material layer, no solvent is used, so the working environment deteriorates and air pollution occurs. There is almost no generation of volatile organic compounds (VOC) that lead to. In addition, since aging (curing) and drying are not required, the time required for production is shortened, and it can be manufactured with compact equipment.

The present invention will be described below based on the best mode.
The method for producing a pressure-sensitive adhesive film of the present invention comprises: a resin layer A for forming a pressure-sensitive adhesive layer that exhibits adhesiveness at normal temperature by energy ray curing; and a base material layer formation that solidifies without exhibiting adhesiveness at normal temperature by energy ray curing. After the resin layer B is coated in multiple layers, the adhesive layer is laminated on at least one surface of the base material layer by irradiating energy rays and completely curing the resin layer A and the resin layer B simultaneously. The formed adhesive film is formed at a time.

  Here, as a method of forming the resin layer A for forming the adhesive layer and the resin layer B for forming the base material layer, multilayer coating on the separator can be preferably employed. In this case, if the resin layer A and the resin layer B are each coated at least one layer on the separator, a general pressure-sensitive adhesive film is formed. In the present invention, the resin layer A for forming the pressure-sensitive adhesive layer and The number and thickness of the base layer-forming resin layer B are not limited as long as the entire multilayer coating has flexibility, and the pressure-sensitive adhesive layer-forming resin layer A and / or depending on the function required. Or the resin layer B for base material layer formation can also be made into multiple layers. The resin layer A for forming the pressure-sensitive adhesive layer may be a multilayer coating of at least two resin layers that become the pressure-sensitive adhesive layer after curing.

  Examples of the separator include a polycarbonate film, a polyarylate film, a polyethersulfone film, a polysulfone film, a polyester film, a polystyrene film, a polyolefin film, a norbornene-based film, a phenoxy ether type polymer film, and an organic gas-resistant film. Single-layer or multi-layer plastic film is peeled with a release agent such as a silicone-based release agent, and at least one side is peelable; a paper is peeled with a silicone-based release agent, etc., and at least one side is peelable Paper: Films such as fluorine resin films and certain polyolefin films, etc., where the film itself has releasability; films formed by internally adding a release agent, and the like. The thickness of the separator is not limited, but is usually 5 to 500 μm, preferably 10 to 100 μm in many cases. The separator is selected according to the pressure-sensitive adhesive used and the intended use (peel strength).

The pressure-sensitive adhesive layer-forming resin layer A can be formed by coating a pressure-sensitive adhesive layer-forming resin composition containing an energy ray-curable compound that is cured by energy ray irradiation. Examples of the energy rays used for curing the resin layer A include heating and active energy rays (ultraviolet rays, electron beams, and in some cases, visible rays).
When curing by heating, it is usual to blend about 0.1 to 5% by weight of a polymerization initiator in advance with respect to the entire resin composition for forming the pressure-sensitive adhesive layer. As the polymerization initiator, an organic peroxide-based or diazonium-based polymerization initiator is preferably used.
When curing is performed by irradiation with ultraviolet rays or visible rays, it is usual to blend about 0.1 to 10% by weight of a polymerization initiator in advance with respect to the entire resin composition for forming the pressure-sensitive adhesive layer. However, it may not be necessary when using a cationic or anionic polymerization method. In the case of irradiation with active energy rays, it is possible to complete the curing by performing a heat treatment as necessary after the irradiation, and conversely, the energy ray irradiation may be performed after the heat treatment. You may combine the above energy beam irradiation.

The photopolymerization initiator used in the case of curing by irradiation with ultraviolet rays or visible rays is not particularly limited. Examples include diethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, among which benzyl dimethyl ketal and 1-hydroxycyclohexyl phenyl. A ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, or the like is preferably used.
As the cationic photopolymerization initiator, initiators such as onium salt, tri (substituted) phenylsulfonium, diazosulfone and iodonium are preferably used. As the anionic photopolymerization initiator, an organometallic initiator such as alkyl lithium is preferably used.
The composition of the resin composition for forming the pressure-sensitive adhesive layer is preferably adjusted so that the glass transition point of the film after curing with energy rays is 20 ° C. or less.

The resin composition for forming the pressure-sensitive adhesive layer is preferably a fluid, solventless, high-viscosity adhesive resin composition. In particular, an adhesive grade acrylic copolymer obtained by copolymerizing a monomer component that gives a soft segment and a monomer component that gives a hard segment (and if necessary, a functional group-containing monomer component or a polyfunctional (meth) acrylate component). What uses a polymer as an essential component is used suitably.
In the present specification, “(meth) acrylate” means “acrylate and / or methacrylate”.

  In the pressure-sensitive adhesive grade acrylic copolymer, a monomer component that gives a soft segment when polymerized is an alkyl acrylate having an alkyl group with 4 or more carbon atoms (n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl). Acrylate, etc.), alkyl methacrylates having 6 or more carbon atoms in the alkyl group (n-hexyl methacrylate, 2-ethylhexyl methacrylate, etc.) and the like. These monomers may be used independently and may be used in combination of 2 or more type.

  Monomer components that give hard segments include alkyl acrylates having 1 to 3 carbon atoms in the alkyl group (such as methyl acrylate), alkyl methacrylates having 1 to 5 carbon atoms in the alkyl group (such as methyl methacrylate), vinyl acetate, and styrene. Is mentioned. These monomers may be used independently and may be used in combination of 2 or more type.

  As functional group-containing monomer components, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl (meth) acrylate, N-methylolacrylamide, 2-hydroxyethyl acrylate , Hydroxyalkyl (meth) acrylates such as 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and the like. These monomers may be used independently and may be used in combination of 2 or more type.

  As polyfunctional (meth) acrylate components, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butylene glycol, 1,6-hexanediol, neopentyl glycol Di-, tri- or poly (meth) acrylates of polyhydric alcohols such as trimethylolpropane, glycerin and pentaerythritol; hydroxyalkyl (meth) acrylates and the like.

The pressure-sensitive adhesive grade acrylic resin composition includes the above-mentioned acrylic copolymer, the monomer that gives the soft segment, the monomer that gives the hard segment, the monomer containing the functional group, and the polyfunctional (meth) acrylate. It is preferable to add in a monomer form. These monomers act as a plasticizer for the acrylic copolymer during film formation to impart fluidity, and then cure and polymerize by irradiation with energy rays. A relatively low molecular weight oligomer or a general plasticizer can be used together with or in place of such a monomer.
There is also a formulation in which the acrylate monomer is added to the oligomer resin in order to increase the viscosity. Specific examples of the oligomer include urethane acrylates such as polyesters and polycarbonates, polyester acrylates, epoxy acrylates, polyethylene glycol diacrylates, commercially available oligoester acrylates, methacrylates similar to the above, and the like. These oligomers may be used alone or in combination of two or more.

  In addition to the above-mentioned acrylic polymer as an essential component, the high viscosity adhesive resin composition includes adhesives such as urethane, polycarbonate, polyester, acrylic urethane, rubber, vinyl, and silicone. An agent grade resin composition can also be used.

  The viscosity of the resin composition for forming the pressure-sensitive adhesive layer is suitably about 20 to 100000 cps / 20 ° C, preferably 20 to 80000 cps / 20 ° C, more preferably 20 to 12000 cps / 20 ° C.

The base material layer-forming resin layer B can be formed by coating a base material layer-forming resin composition. The resin composition for forming the base material layer is preferably a fluid, solventless energy ray-curable composition. This energy ray-curable composition contains an energy ray-curable compound that is cured by energy rays as an essential component, and a resin having no tack after curing is used.
Examples of energy rays used for curing include heating and active energy rays (ultraviolet rays, electron beams, and in some cases, visible rays).
In the case of curing by heating, it is usual to blend about 0.1 to 5% by weight of a polymerization initiator in advance with respect to the entire resin composition for forming the base layer. As the polymerization initiator, an organic peroxide-based or diazonium-based polymerization initiator is preferably used.
When curing is carried out by irradiation with ultraviolet rays or visible rays, it is usual to blend about 0.1 to 10% by weight of a polymerization initiator in advance with respect to the entire resin composition for forming the base layer. However, it may not be necessary when using a cationic or anionic polymerization method. In the case of irradiation with active energy rays, it is possible to complete the curing by performing a heat treatment as necessary after the irradiation, and conversely, the energy ray irradiation may be performed after the heat treatment. You may combine the above energy beam irradiation.

The photopolymerization initiator used in the case of curing by irradiation with ultraviolet rays or visible rays is not particularly limited. Examples include diethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, among which benzyl dimethyl ketal and 1-hydroxycyclohexyl phenyl. A ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, or the like is preferably used.
As the cationic photopolymerization initiator, initiators such as onium salt, tri (substituted) phenylsulfonium, diazosulfone and iodonium are preferably used. As the anionic photopolymerization initiator, an organometallic initiator such as alkyl lithium is preferably used.
The blending of the energy beam curable composition for forming the base material layer is preferably adjusted so that the glass transition point of the film after energy beam curing exceeds 20 ° C.

  Examples of the energy ray curable compound include monofunctional (meth) acrylate components such as alkyl acrylate and alkyl methacrylate; polyfunctional such as di-, tri- or poly (meth) acrylate of polyhydric alcohol and hydroxyalkyl (meth) acrylate (Meth) acrylate components: functional group-containing monomer components such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl (meth) acrylate, and N-methylolacrylamide Vinyl acetate, styrene, acrylic urethane oligomers and the like.

In the method for producing a pressure-sensitive adhesive film of the present invention, a resin layer A for forming a pressure-sensitive adhesive layer and a resin layer B for forming a base material layer are coated on a separator or other coated material, and irradiated with energy rays. Then, the resin layer A for forming the adhesive layer and the resin layer B for forming the base material layer are simultaneously cured. Moreover, when irradiating an energy ray, the separator etc. which can permeate | transmit an energy ray can be covered on the coating layer as needed.
Thereby, the adhesive film by which the adhesive layer was laminated | stacked on the at least one surface of the base material layer can be formed at once. The pressure-sensitive adhesive film thus produced preferably has a glass transition point after curing of the base material layer of more than 20 ° C. and a glass transition point of the pressure-sensitive adhesive layer after curing of 20 ° C. or less. Thereby, the adhesive film which has an adhesive layer which expresses adhesiveness at normal temperature, and a base material layer which does not express adhesiveness at normal temperature can be obtained.

  The viscosity of the resin composition for forming the base layer may be the same as or different from that of the resin composition for forming the adhesive layer. By coating each layer and irradiating it with energy rays before the layers are completely compatible, the base material layer and the adhesive layer can be obtained in a lump. It is considered that it is better to first coat a resin composition having a high viscosity and then coat a resin composition having a low viscosity because an existing apparatus can be used in an actual production process. Also, before coating a low-viscosity resin composition on a support such as a separator, a method of coating after slightly increasing the viscosity by irradiating energy rays that do not completely cure, or after coating with a low viscosity Resin that is coated first, such as by applying a layer of the next low-viscosity composition after a slight increase in viscosity by irradiating energy rays that are not completely cured, followed by a procedure of completely curing with energy rays. In the actual production process, it is effective to increase the viscosity of the composition by some method and then coat the next resin composition.

As a manufacturing method, although the following method can be considered, it is not limited.
Production method (1) in which the resin is cured by irradiating active energy rays (ultraviolet rays, electron beams, and in some cases visible light) with the oxygen concentration in the atmosphere in which the energy ray irradiation treatment is performed as low as possible, and the active energy A production method (2) in which oxygen is not brought into contact with the energy curable resin even when a high concentration of oxygen exists in the atmosphere in which the irradiation process is performed, and the active energy irradiation is performed.

  Specifically, the production method (1) includes forming a layer structure of separator (1) / resin layer for forming an adhesive layer (A) / resin layer for forming a base layer (B), and then active energy rays. The structure which manufactures the adhesive film which has a layer structure of a separator (1) / adhesive layer (a) / base material layer (b) after irradiation is considered. When the separator (2) is necessary as a process or product after irradiation with active energy rays, the separator (2) may be bonded before irradiation with active energy rays, and the separator (2) may be applied while irradiating with active energy rays. It may be pasted or in any order such as pasting the separator (2) after irradiation with active energy rays.

In the case of the production method (1), since the separator (2) is not bonded before the active energy ray irradiation, the atmosphere in which the active energy ray irradiation treatment is performed is not nitrogen or the like so as not to be insufficiently cured due to polymerization inhibition. It is necessary to replace the gas in an atmosphere in which the oxygen concentration is lowered as much as possible using an active gas. The term “polymerization inhibition” as used herein means that a radical that is easily absorbed by radicals such as oxygen is present in the atmosphere irradiated with active energy rays, so that radicals used for polymerization are taken and the polymerization reaction does not proceed. means. Particularly in the case of oxygen, in order to suppress oxygen inhibition by oxygen radicals generated by active energy ray irradiation, it is preferable to reduce the oxygen concentration in the atmosphere in which the energy ray irradiation treatment is performed by nitrogen gas replacement or the like as much as possible.
In order to cure even if there is polymerization inhibition, it is known to add a large amount of expensive polymerization initiator, but the degradation product of the photopolymerization initiator remains as an impurity and the adhesive force changes, It is not effective in actual production due to problems such as glue remaining or transfer of decomposition products, and problems such as increased total irradiation amount of active energy rays and reduced processing speed. For this reason, it is necessary to perform gas replacement with nitrogen or the like.

Specifically, the production method (2) comprises forming a layer structure of separator (1) / resin layer for forming an adhesive layer (A) / resin layer for forming a base layer (B), and separating the separator (2). Is bonded to the resin layer (B) for forming the base material layer, or after being applied, by irradiating active energy rays, the separator (1) / adhesive layer (a) / base material layer (b The structure which manufactures the adhesive film which has a layer structure of) / separator (2) can be considered.
When the separator (2) is unnecessary as a process or product after irradiation with active energy rays, the separator (2) is peeled off after irradiation with energy rays to obtain a product.

By using the separator (2), it is possible to easily form an environment free from polymerization inhibition without the need for gas replacement such as nitrogen, the surface protection of the base material layer (b), and the base material layer by transfer of the separator surface structure It is possible to increase the added value with an inexpensive apparatus such as the control of the surface shape of (b). However, in order to paste the separator (2) neatly, the viscosity of the resin layer (A) for forming the pressure-sensitive adhesive layer and the resin layer (B) for forming the base material layer are preferably higher.
Therefore, in the case of the resin layer (B) for forming the base material layer having a low viscosity, it is necessary to devise procedures such as pasting the separator (2) in a state where the viscosity is increased by slightly curing, After slightly curing in the state of the layer configuration of separator (1) / resin layer for forming the adhesive layer (A) / resin layer for forming the base layer (B), the separator (2) was bonded. An online or offline combination of the manufacturing method (1) and the manufacturing method (2), such as irradiation with active energy rays again for complete curing, is considered to be effective in actual production.

Further, only the separator (1) / resin layer forming resin layer (A) is combined with the manufacturing method (1) or the separator (2), and once irradiated with active energy rays in the state of the manufacturing method (2), it is slightly cured. Then, the resin layer (B) for forming the base material layer is coated on the resin layer (A) for forming the pressure-sensitive adhesive layer, and the manufacturing method (2) is combined with the manufacturing method (1) or the separator (2). In the state of), various procedures can be used for the laminating method, for example, by irradiating with active energy rays and completely curing each layer, and finally completely curing the entire layer.
Moreover, when there is little superposition | polymerization inhibition of oxygen radicals, such as hardening by heating, you may select any of a manufacturing method (1) or a manufacturing method (2).
Further, the pressure-sensitive adhesive layer (a) on both sides of the base material layer (b), such as separator (1) / pressure-sensitive adhesive layer (a) / base material layer (b) / pressure-sensitive adhesive layer (a) / separator (2). The structure of the double-sided pressure-sensitive adhesive film having) can also be produced by any one of the production methods (1) and (2) or a combination of both production methods.

  The separator (1) on the pressure-sensitive adhesive layer side is usually peeled and removed immediately before the pressure-sensitive adhesive film is attached to the adherend. The separator (2) on the side of the base material layer may be peeled off at the time when the necessity arises, and depending on the application, it may not be peeled off after the adhesive film is attached to the adherend. For example, in order to protect the adhesive film attached to the adherend, the separator (2) on the base material layer side can be left attached.

  In the case where the separators (1) and (2) are long films or sheets wound up in a roll shape, the produced pressure-sensitive adhesive film can be wound up again in a roll shape, and the production method is excellent in productivity. It becomes. In this case, as a manufacturing facility, a feeding device for feeding the wound separator (1), and a multilayer coating of the resin layer A for forming the adhesive layer and the resin layer B for forming the base material layer on the separator (1). Coater, laminating roll for laminating separator (2) on multilayer coating, energy layer irradiation device for curing resin layer A for forming adhesive layer and resin layer B for forming base layer, adhesive layer, and It can comprise by the winding apparatus which winds up the adhesive film which the base material layer hardened | cured.

  Conventionally, in the case of producing a pressure-sensitive adhesive film by applying a solvent-type pressure-sensitive adhesive to a base film, a long dryer is required. The total equipment length up to the equipment can be stored compactly. Moreover, since drying and aging are not required, the time required for production can be shortened, productivity can be improved, and dust can be prevented from adhering to the product.

  In the present invention, the coating object on which the resin layer A for forming the pressure-sensitive adhesive layer and the resin layer B for forming the base material layer are subjected to multilayer coating need not be a pressure-sensitive adhesive film separator; Using a treated stainless steel plate or the like, multilayer coating and energy ray irradiation can be performed thereon to produce an adhesive film having an adhesive layer and a base material layer. In this case, after peeling off the adhesive film from the object to be coated, it may be combined with a separator to protect the adhesive layer of the produced adhesive film. Moreover, you may affix the adhesive film peeled off from the to-be-coated article to the adherend as it is.

As described above, according to the method for producing a pressure-sensitive adhesive film of the present invention, the multilayer-coated pressure-sensitive adhesive layer forming resin layer A and the base material layer forming resin layer B are simultaneously polymerized and cured by irradiation with energy rays. Since the adhesive layer and the base material layer are formed at the same time, the adhesiveness of the adhesive layer to the base material layer is improved, and the adhesive layer such as glass or metal plate is attached to an adherend that has high adhesive strength. However, when the adhesive film is peeled off from the adherend, the problem of adhesive residue hardly occurs.
Moreover, according to this invention, the thickness of a base material layer and an adhesive can be set freely, and the problem on manufacture does not arise. Therefore, the thickness of the base material layer can be reduced, and a thinner adhesive film can be produced than before.
Since there is no step of winding the base material layer into a roll alone during the production process, it is not necessary to mix a component for imparting slipperiness such as a lubricant to the base material layer. Therefore, an adhesive film excellent in optical characteristics such as transparency can be produced.

  When a solvent-free energy ray curable resin composition is used as the resin layer A for forming the adhesive layer and the resin layer B for forming the base material layer, no solvent is used, so that the working environment is deteriorated or air pollution occurs. There is little generation of connected volatile organic compounds (VOC). For this reason, the expense and space for installing the equipment which collects and processes VOC can be reduced. In addition, since aging (curing) and drying are not required, the time required for production is shortened, and it can be manufactured with compact equipment.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. Hereinafter, “parts” means parts by weight.

Example 1
As an example of the release films (1) and (2), a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm and having a release treatment with a silicone release agent on one side was prepared.
In addition, as a fluid, solventless, high-viscosity adhesive resin composition (A) for forming the adhesive layer (a), 170 parts of a butyl acrylate-vinyl acetate (65:35 by weight ratio) copolymer, A resin solution having a viscosity of 11500 cps / 20 ° C. comprising 15 parts of butyl acrylate, 5 parts of vinyl acetate, 10 parts of acrylic acid and 2 parts of benzoin isobutyl ether (photopolymerization initiator) was prepared. Furthermore, as a UV curable resin (B) having no tack for forming the base material layer (b), a mixed liquid in which a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) is mixed with 2-hydroxypropyl methacrylate. Prepared.

On the release film (1), two layers of the high-viscosity adhesive resin composition (A) and the UV curable resin (B) for forming the pressure-sensitive adhesive layer (a) are simultaneously coated. The release film (2) was pasted on the coating layer so as not to contain bubbles. The coating layer was cured by irradiating with ultraviolet rays under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light amount of 600 mJ / cm ² . Thereby, the adhesive film which has a layer structure of peeling film (1) / adhesive layer (a) / base material layer (b) / release film (2) was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared in the vicinity of about −25 ° C., and Tg was considered to be −25 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

(Example 2)
2-ethylhexyl acrylate-methyl methacrylate-acrylic acid (70:20:10 by weight) co-polymerized as a fluid, solventless, high-viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) A resin solution having a viscosity of 5500 cps / 20 ° C. consisting of 20 parts of butyl acrylate, 10 parts of methyl methacrylate, 10 parts of acrylic acid and 3 parts of benzoin isobutyl ether (photopolymerization initiator) was prepared in 160 parts of the combined body. Except for the high-viscosity adhesive resin composition (A), the layer structure of release film (1) / adhesive layer (a) / base material layer (b) / release film (2) was the same as in Example 1. A pressure-sensitive adhesive film was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -10 ° C, and Tg was considered to be -10 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

(Example 3)
As a fluid, solventless, high-viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a), 50 parts of 2-ethylhexyl acrylate, 50 parts of 2-hydroxypropyl acrylate, 2-hydroxy-3-acryl A resin liquid having a viscosity of 30 cps / 20 ° C. comprising 0.50 part of leuoxypropyl methacrylate and 3 parts of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) was prepared. Except for the high-viscosity adhesive resin composition (A), the layer structure of release film (1) / adhesive layer (a) / base material layer (b) / release film (2) was the same as in Example 1. A pressure-sensitive adhesive film was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -10 ° C, and Tg was considered to be -10 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

Example 4
As a fluid, solventless, high-viscosity adhesive resin composition (A) for forming an adhesive layer (a), 50 parts of a urethane acrylate oligomer having a benzene ring as a hard segment and an alkyl group as a repeating unit A resin liquid having a viscosity of 550 cps / 20 ° C. comprising 50 parts of 2-ethylhexyl acrylate and 3 parts of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) was prepared. Except for the high-viscosity adhesive resin composition (A), the layer structure of release film (1) / adhesive layer (a) / base material layer (b) / release film (2) was the same as in Example 1. A pressure-sensitive adhesive film was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared in the vicinity of about −25 ° C., and Tg was considered to be −25 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

(Example 5)
2-ethylhexyl acrylate-methyl methacrylate-acrylic acid (70:20:10 by weight) co-polymerized as a fluid, solventless, high-viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) Prepare a resin solution with a viscosity of 5500 cps / 20 ° C. in 160 parts of the coal, comprising 20 parts of butyl acrylate, 10 parts of methyl methacrylate, 10 parts of acrylic acid and 3 parts of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals). did. Further, as a UV curable resin (B) having no tack for forming the base material layer (b), a mixed liquid in which a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) is mixed with methyl methacrylate is prepared. did. Except for these high-viscosity adhesive resin compositions (A) and UV curable resins (B), the same procedure as in Example 1 was performed, except for release film (1) / adhesive layer (a) / base material layer (b) / release. An adhesive film having the layer configuration of the film (2) was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared in the vicinity of about −25 ° C., and Tg was considered to be −25 ° C. It is done. Moreover, Tg of the base material layer (b) was about 105 ° C.

(Example 6)
As a fluid, solventless, high-viscosity adhesive resin composition (A) for forming an adhesive layer (a), 50 parts of bisphenol A epoxy acrylate, 100 parts of 2-ethylhexyl acrylate and a photopolymerization initiator (trade name: A resin solution having a viscosity of 70 cps / 20 ° C. comprising 3 parts of Irgacure 184 (manufactured by Ciba Specialty Chemicals) was prepared. Further, as a UV curable resin (B) having no tack for forming the base material layer (b), a mixed liquid in which a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) is mixed with methyl methacrylate is prepared. did. Except for these high-viscosity adhesive resin compositions (A) and UV curable resins (B), the same procedure as in Example 1 was performed, except for release film (1) / adhesive layer (a) / base material layer (b) / release. An adhesive film having the layer configuration of the film (2) was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -30 ° C, and Tg was considered to be -30 ° C. It is done. Moreover, Tg of the base material layer (b) was about 105 ° C.

(Example 7)
As an example of the release films (1) and (2), a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm and having a release treatment with a silicone release agent on one side was prepared.
Moreover, as a fluid solventless high viscosity adhesive resin composition (A) for forming the adhesive layer (a), 50 parts of 2-ethylhexyl acrylate, 50 parts of 2-hydroxypropyl acrylate, 2-hydroxy-3 A resin liquid having a viscosity of 30 cps / 20 ° C. comprising 0.50 part of acryloyloxypropyl methacrylate and 3 parts of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) was prepared. Furthermore, as a UV curable resin (B) having no tack for forming the base material layer (b), a mixed liquid in which a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) is mixed with 2-hydroxypropyl methacrylate. Prepared.

The above release film (1) is coated with the above-mentioned pressure-sensitive adhesive layer (a) high-viscosity adhesive resin composition (A), and the release film (2) is pasted onto the coating layer so that no bubbles enter. Combined. The resin was cured by irradiating with ultraviolet rays under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light amount of about 50 mJ / cm ² . The release film (2) was peeled off, the release surface was coated with a UV curable resin (B), and a new release film (2) was pasted onto these two coating layers so that no bubbles would enter. The coating layer was completely cured by irradiating with ultraviolet rays under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light amount of 600 mJ / cm ² . Thereby, the adhesive film which has a layer structure of peeling film (1) / adhesive layer (a) / base material layer (b) / release film (2) was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -10 ° C, and Tg was considered to be -10 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

(Example 8)
As a fluid, solventless, high-viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a), 50 parts of 2-ethylhexyl acrylate, 50 parts of 2-hydroxypropyl acrylate, 2-hydroxy-3-acryl Add 0.50 parts of leuoxypropyl methacrylate and 3 parts of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) with ultraviolet irradiation while stirring under nitrogen purge beforehand, and add oxygen Thus, a resin solution of a resin composition having a viscosity of 900 cps / 20 ° C. in a state where the reaction was stopped was prepared. Except for the high-viscosity adhesive resin composition (A), the layer structure of release film (1) / adhesive layer (a) / base material layer (b) / release film (2) was the same as in Example 1. A pressure-sensitive adhesive film was obtained.

About the obtained adhesive film, when peeling film (2) was peeled and removed and the base material layer (b) was touched by hand, it turned out that it is a state without a tack. Moreover, when this adhesive film was bent by hand, it was confirmed by cross-sectional microscope observation that it did not peel at the interface of the adhesive layer (a) / base material layer (b). When the surface from which the release film (1) was gradually peeled was touched with a hand, it was confirmed that it was a tacky adhesive surface. Furthermore, when the adhesive film which peeled peeling film (1), (2) was bonded to common glass, the sticking operation was also smooth.
In order to confirm the cutability which is an important performance of the adhesive film, it was cut with a razor blade (made by Feather Safety Razor Co., Ltd., product name FAS-10), and the substrate layer / adhesive layer interface was observed under a microscope. I was able to confirm that there was no. Furthermore, when the cross section of the interface was observed with a polarizing microscope, it was not possible to observe a clear interface, and it was confirmed that the interface was a so-called gradient layer, and the interface was strengthened by each resin forming a gradient layer. Estimated to be in close contact.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -10 ° C, and Tg was considered to be -10 ° C. It is done. Moreover, Tg of the base material layer (b) was about 76 ° C.

(Comparative Example 1)
As an example of the release films (1), (2), (3) and (4), a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm and having a release treatment with a silicone release agent on one side was prepared.
As the high viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) and the UV curable resin (B) for forming the base material layer (b), those prepared in Example 1 were used.

After the above-mentioned release film (1) is coated with the high-viscosity adhesive resin composition (A) for forming the above-mentioned pressure-sensitive adhesive layer (a), the release film (2) is bonded so that bubbles do not enter. It was. A laminate having a layer configuration of release film (1) / adhesive layer (a) / release film (2) by irradiating with ultraviolet rays under conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of 600 mJ / cm ^2. Manufactured.
Similarly, after the release film (3) was coated with the above-described UV curable resin (B), the release film (4) was bonded to prevent bubbles from entering. A laminate having a layer structure of release film (3) / base material layer (b) / release film (4) by irradiating with ultraviolet rays under conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of 600 mJ / cm ^2. Manufactured.
For the pressure-sensitive adhesive layer (a), the release film (1) was peeled off, and for the base material layer (b), the release film (4) was peeled off, and the peeled surfaces were bonded together by a roll press. Thereby, the adhesive film which has a layer structure of peeling film (2) / adhesive layer (a) / base material layer (b) / release film (3) was obtained.

  About the obtained adhesive film, when the base material layer (b) after peeling and removing a peeling film (3) was touched by hand, it turned out that it is a state without a tack. Moreover, after bending this adhesive film by hand, when the interface of adhesive layer (a) / base material layer (b) was observed with the cross-sectional microscope, the part peeled in the interface has been confirmed. When the cross section of the interface was observed with an optical microscope / polarizing microscope, a clear interface was observed, and it was confirmed that the interface was peeled off. Moreover, after peeling off a peeling film (2) gradually, when pasting to general glass, it was able to stick, but peeling was at the interface of an adhesive layer (a) / base material layer (b). Sometimes occurred and whitened.

(Comparative Example 2)
As the high viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) and the UV curable resin (B) for forming the base material layer (b), those prepared in Example 3 were used. Except for these high-viscosity adhesive resin compositions (A) and UV curable resins (B), a release film (1) / adhesive layer (a) / base material layer (b) / release was carried out in the same manner as in Comparative Example 1. An adhesive film having the layer configuration of the film (2) was obtained.

  About the obtained adhesive film, when the base material layer (b) after peeling and removing a peeling film (3) was touched by hand, it turned out that it is a state without a tack. Moreover, after bending this adhesive film by hand, when the interface of adhesive layer (a) / base material layer (b) was observed with the cross-sectional microscope, the part peeled in the interface has been confirmed. When the cross section of the interface was observed with an optical microscope / polarizing microscope, a clear interface was observed, and it was confirmed that the interface was peeled off. Moreover, after peeling off a peeling film (2) gradually, when pasting to general glass, it was able to stick, but peeling was at the interface of an adhesive layer (a) / base material layer (b). Sometimes occurred and whitened.

(Comparative Example 3)
The high viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) and the UV curable resin (B) for forming the base material layer (b) were those prepared in Example 4. Except for these high-viscosity adhesive resin compositions (A) and UV curable resins (B), a release film (1) / adhesive layer (a) / base material layer (b) / release was carried out in the same manner as in Comparative Example 1. An adhesive film having the layer configuration of the film (2) was obtained.

  About the obtained adhesive film, when the base material layer (b) after peeling and removing a peeling film (3) was touched by hand, it turned out that it is a state without a tack. Moreover, after bending this adhesive film by hand, when the interface of adhesive layer (a) / base material layer (b) was observed with the cross-sectional microscope, the part peeled in the interface has been confirmed. When the cross section of the interface was observed with an optical microscope / polarizing microscope, a clear interface was observed, and it was confirmed that the interface was peeled off. Moreover, after peeling off a peeling film (2) gradually, when pasting to general glass, it was able to stick, but peeling was at the interface of an adhesive layer (a) / base material layer (b). Sometimes occurred and whitened.

(Comparative Example 4)
As an example of the release film (1), a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm and having a release treatment with a silicone release agent on one side was prepared.
As a high-viscosity adhesive resin composition (A) for forming an adhesive layer (a), 3 parts of a polyisocyanate curing agent is added to 100 parts of 2-ethylhexyl acrylate-acrylic acid (95: 5 by weight) copolymer. The toluene solvent was added to adjust the viscosity to 500 cps. A polyethylene terephthalate film (Toyobo: E5000) was used as the substrate (b).

  The above base material (b) is coated with the above-mentioned pressure-sensitive adhesive layer (a) high-viscosity adhesive resin composition (A) and then dried at 80 ° C. so that the release film (2) does not contain bubbles. Pasted together. Then, the laminated body which has a layer structure of peeling film (1) / adhesive layer (a) / base material (b) was manufactured by making it age | cure | ripen and harden | cure at 40 degreeC for one week.

When the interface of the pressure-sensitive adhesive layer (a) / base material (b) of the obtained pressure-sensitive adhesive film was observed with a cross-sectional microscope, a clear interface was observed. Moreover, after peeling off a peeling film (2) gradually, when pasting to general glass, it was able to stick, and although whitening was not recognized at this time, when it tried to peel from glass again, it was adhesion. The interface of the agent layer (a) / base material (b) and the cohesive failure of the pressure-sensitive adhesive layer (a) may occur, resulting in whitening.
When the glass transition point (Tg) of the pressure-sensitive adhesive layer (a) was examined according to JIS K7224-4, a peak of dynamic loss tangent (Tanδ) appeared around -60 ° C, and Tg was considered to be -60 ° C. It is done. Moreover, Tg of the base material (b) was about 70 ° C.

(Comparative Example 5)
As an example of the release films (1), (2) and (3), a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm and having a release treatment with a silicone release agent on one side was prepared. As the high viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a) and the UV curable resin (B) for forming the base material layer (b), those prepared in Example 3 were used.

The release film (1) is coated with the high-viscosity adhesive resin composition (A) for forming the pressure-sensitive adhesive layer (a), and the release film (3) is pasted on the coating layer so as not to cause bubbles. Combined. The coating layer was completely cured by irradiating with ultraviolet rays under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of about 600 mJ / cm ² . The release film (3) was peeled off, the release surface was coated with a UV curable resin (B), and a new release film (2) was pasted onto these two coating layers so as not to contain bubbles. The coating layer was completely cured by irradiating with ultraviolet rays under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light amount of 600 mJ / cm ² . Thereby, the adhesive film which has a layer structure of peeling film (1) / adhesive layer (a) / base material layer (b) / release film (2) was obtained.

  When the interface of the adhesive layer (a) / base material layer (b) of the obtained adhesive film was observed with a cross-sectional microscope, a clear interface was observed. Moreover, after peeling off a peeling film (2) gradually, when pasting to general glass, it was able to stick, and although whitening was not recognized at this time, when it tried to peel from glass again, it was adhesion. The interface of the agent layer (a) / base material layer (b) and the cohesive failure of the pressure-sensitive adhesive layer (a) may occur, resulting in whitening.

  The above evaluation results are summarized in Table 1.

  As described above, the pressure-sensitive adhesive films of Examples 1 to 8 can be confirmed by cross-sectional microscopic observation that they do not peel off at the pressure-sensitive adhesive layer (a) / base material layer (b) interface when bent by hand. It can be confirmed that the substrate layer / adhesive layer interface of the cross section cut with the blade is not peeled off under a microscope, and further, when the cross section is observed with a polarizing microscope, a clear interface cannot be observed. It was confirmed that it was a so-called gradient layer. From these results, the substrate adhesion can be evaluated as “◯”. Moreover, when the adhesive film which peeled peeling film (1) and (2) was bonded to common glass, the sticking operation was also smooth. For this reason, the pasting property can be evaluated as “◯”. Therefore, the comprehensive evaluation can be evaluated as “◎”. Since the manufacturing method of the adhesive film of Examples 1-8 does not have the use of a solvent and a drying process, it can be evaluated as “no VOC generation”.

In contrast, the pressure-sensitive adhesive films of Comparative Examples 1 to 3 were peeled off at the interface when the pressure-sensitive adhesive layer (a) / base material layer (b) interface was observed with a cross-sectional microscope after the adhesive film was bent by hand. When the cross section of the interface is observed with an optical microscope / polarizing microscope, a clear interface is observed and it can be confirmed that the interface is peeled off, and the release film (2) After being peeled gradually, it was pasted to general glass, but it could be stuck, but peeling occurred at the interface of the pressure-sensitive adhesive layer (a) / base material layer (b) and whitening occurred. It was. From these results, the bonding property can be evaluated as “◯”, the substrate adhesion as “×”, and the comprehensive evaluation as “×”.
In the pressure-sensitive adhesive films of Comparative Examples 4 and 5, a clear interface was observed when the pressure-sensitive adhesive layer (a) / substrate (b) interface was observed with a cross-sectional microscope, and the release film (2) was gradually peeled off. Then, when pasting to general glass, it was possible to stick, and whitening was not recognized at this point, but when it was peeled off again from the glass, the pressure-sensitive adhesive layer (a) / base material (b) The cohesive failure of the interface and the pressure-sensitive adhesive layer (a) occurred and sometimes whitened. From these results, the bonding property can be evaluated as “◯”, the substrate adhesion as “Δ”, and the comprehensive evaluation as “×”. Since the manufacturing method of the adhesive film of the comparative example 4 has a drying process of a toluene solvent, it can be evaluated that “VOC is generated”.

  The manufacturing method of the adhesive film of this invention can be utilized for manufacture of various adhesive films, for example, an optical film, and a protective film.

Claims (7)

A resin layer A for forming a pressure-sensitive adhesive layer that exhibits tackiness at normal temperature by energy ray curing and a resin layer B for forming a base material layer that solidifies without exhibiting tackiness at normal temperature by energy ray curing are coated in multiple layers. Later, by manufacturing the adhesive film in which the adhesive layer is laminated on at least one surface of the base material layer at a time by irradiating energy rays and completely curing the resin layer A and the resin layer B at the same time. A method,
The resin layer A and the resin layer B are made of a solventless energy ray curable composition,
The pressure-sensitive adhesive layer obtained by curing the resin layer A contains one or more resin monomers selected from a resin monomer group consisting of resin monomers that give a soft segment, and a resin monomer and / or a functional group that gives a hard segment. It comprises an acrylic copolymer obtained by copolymerizing one or more resin monomers selected from the resin monomer group consisting of resin monomers,
The resin monomer that gives the soft segment consists of a resin monomer group consisting of an alkyl acrylate having an alkyl group with 4 or more carbon atoms and an alkyl methacrylate with an alkyl group having 6 or more carbon atoms,
The resin monomer that gives the hard segment consists of a resin monomer group consisting of alkyl acrylate having 1 to 3 carbon atoms in the alkyl group, alkyl methacrylate having 1 to 5 carbon atoms in the alkyl group, and vinyl acetate,
The functional group-containing resin monomer used for the acrylic copolymer of the pressure-sensitive adhesive layer is acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl ( (Meth) acrylate, N-methylolacrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, and bisphenol A epoxy It consists of a resin monomer group consisting of acrylate,
A method for producing an adhesive film, wherein the base material layer obtained by curing the resin layer B is made of an acrylic UV curable resin having no tackiness after curing.   The base material layer formed by curing the resin layer B is alkyl (meth) acrylate, di-, tri- or poly (meth) acrylate of polyhydric alcohol, hydroxyalkyl (meth) acrylate, acrylic acid, methacrylic acid, crotonic acid, Acrylic UV curable resin using one selected from the group of resin monomers consisting of itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl (meth) acrylate, and N-methylolacrylamide It consists of these, The manufacturing method of the adhesive film of Claim 1 characterized by the above-mentioned.   The pressure-sensitive adhesive film is produced as a layer structure comprising: first separator / resin layer A for forming a pressure-sensitive adhesive layer / resin layer B for forming a base material layer / second separator. The manufacturing method of the adhesive film of description.   The method for producing a pressure-sensitive adhesive film according to any one of claims 1 to 3, wherein the resin layer A is multilayer-coated with at least two resin layers that become pressure-sensitive adhesive layers after curing.   The said resin layer A and the resin layer B carry out multilayer coating on a separator, The manufacturing method of the adhesive film as described in any one of Claim 1 to 4 characterized by the above-mentioned.   A pressure-sensitive adhesive film obtained by the production method according to any one of claims 1 to 5, wherein a pressure-sensitive adhesive layer is laminated on at least one surface of a base material layer.   The pressure-sensitive adhesive film according to claim 6, wherein the glass transition point after curing of the base material layer exceeds 20 ° C., and the glass transition point after curing of the pressure-sensitive adhesive layer is 20 ° C. or less.