JP2008297337A - Method for producing foamed resin self-adhesive tape and foamed resin self-adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a foamed resin self-adhesive tape by which the self-adhesive tape having excellent adhesion between a self-adhesive layer and a foamed resin layer can be produced simply. <P>SOLUTION: The method for producing the foamed resin self-adhesive tape comprises coating an energy ray-curable resin layer exhibiting self-adhesive properties at normal temperature after being cured, and a foamable resin layer prepared by mixing thermally foaming particles in a resin exhibiting the self-adhesive properties at normal temperature after being cured, or an energy ray-curable resin curable without exhibiting the self-adhesive properties, on a separator having releasability such as a release film to form a multilayered coating, and irradiating the multilayer-coated film with the energy ray to cure each coated layer and to afford the foamed resin self-adhesive tape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a foamed resin adhesive tape used for automobiles, building materials, households, and the like. More specifically, the present invention relates to a method for producing a foamed resin adhesive tape having a foamed resin layer as a base material and having an adhesive layer on at least one surface thereof, and the foamed resin adhesive tape.

  Foamed resin adhesive tape is made by applying an adhesive to at least one side of the foamed resin base material, and because it has cushioning properties, it can be bonded to uneven surfaces, and the foamed resin layer absorbs the force applied to the adhesive tape. Therefore, there is an advantage that adhesive strength and holding power are high. Moreover, the foamed resin double-sided pressure-sensitive adhesive tape in which a pressure-sensitive adhesive is applied to both sides of the foamed resin base material can be effectively used for bonding two kinds of materials having different coefficients of thermal expansion. When materials having different coefficients of thermal expansion are bonded together with a single adhesive, the thermal stress generated due to the difference in thermal expansion of the bonded materials may not be relaxed and may be peeled off. However, when materials having different coefficients of thermal expansion are bonded using a foamed resin double-sided pressure-sensitive adhesive tape, the function of relieving thermal stress increases, so that it does not peel off. Because of these advantages, it can be used to fix interior and exterior nameplates for automobiles, nameplates to household electrical appliances, temporary fixing of housing window frame seals, housing interior finishing materials, and insulation and soundproofing of interior and exterior panels. It is used for heat insulation materials such as air conditioners, seals and packing materials for electronic parts and devices, and fixing household accessories such as display plates and simple hooks.

  Generally, a foamed resin adhesive tape is manufactured by subjecting one surface of a foamed resin layer made of polyolefin, polyvinyl chloride, acrylic, synthetic rubber, or the like to an adhesive process. Moreover, in the foamed resin double-sided pressure-sensitive adhesive tape, the adhesive is applied to one surface of the foamed resin layer, and then the adhesive is also applied to the opposite surface of the foamed resin layer. The adhesive is applied by directly applying the adhesive to the foamed resin layer, and then bonding the release paper or release film after drying, applying the adhesive to the release paper or release film, and drying the foamed resin layer One of the methods for pasting the two is used. Since the foamed resin layer to be used is thick, the winding length when wound on a roll body is also limited. For this reason, when the processing amount increases, the foamed resin layer prepared and prepared in advance must be frequently set (replaced), and the preparation of the foamed resin layer may be the rate-limiting of the adhesive processing. In addition, since processing loss occurs in each process during the production of the foamed resin layer and during the adhesive processing, the overall production efficiency is not necessarily good.

  Furthermore, polyolefin resin and other foamed resin layers have a problem of poor adhesion to the pressure-sensitive adhesive. In order to improve the anchoring force of the adhesive to the foamed resin layer, it is considered that the adhesive resin processed directly on the foamed resin layer is preferred, but the olefinic foamed resin layer has poor heat resistance and is directly adhesively processed. Hard to do. In order to improve the anchoring force of the adhesive, surface activation treatment such as corona treatment, ozone treatment, and plasma treatment must be applied to the surface of the foamed resin layer in advance, increasing the number of processes and improving productivity and delivery time. There was a problem in terms of management. In the case of a foamed resin double-sided pressure-sensitive adhesive tape, two pressure-sensitive adhesive processes are required to provide pressure-sensitive adhesive layers on both sides of the foamed resin layer.

  In Patent Document 1, it is proposed that an acrylic photopolymerizable pressure-sensitive adhesive is applied and then irradiated with ultraviolet rays as a method of performing an adhesive processing directly on the foamed resin layer. However, even when this method is used to produce a double-sided pressure-sensitive adhesive tape, the pressure-sensitive adhesive process must be performed twice, and the productivity is not necessarily good.

For this reason, Patent Documents 2 to 8 propose a method of foaming the pressure-sensitive adhesive layer itself. However, these methods have problems such as a decrease in cohesive strength of adhesive, heat resistance, and stress relaxation characteristics. For this reason, Patent Documents 9 to 11 and the like have proposed to crosslink an adhesive layer having a foam structure. However, since the pressure-sensitive adhesive itself is foamed even in these methods, there is a problem that the range in which the pressure-sensitive adhesive properties can be selected is limited.
JP-A-6-49418 JP-A-62-263278 Japanese Patent Publication No. 64-6678 JP-A-2-240182 Japanese Patent Publication No. 2-29705 JP-A-60-76582 JP 2000-169802 A JP 2000-169803 A JP 55-90525 A JP-A-63-225684 JP 2002-80817 A

  The present invention has been made in view of the above circumstances, and has excellent adhesiveness between the pressure-sensitive adhesive layer and the foamed resin layer, has a wide selection range of adhesive properties, is simple in manufacture, and has excellent productivity. It aims at providing the manufacturing method of an adhesive tape.

  In order to solve the above problems, the present invention provides a resin layer that exhibits adhesive performance at room temperature by energy ray curing, or a foamed resin layer in which thermally foamed particles are mixed in a resin that solidifies without exhibiting adhesive performance, and an energy beam. After the multilayer coating of the pressure-sensitive adhesive layer-forming pressure-sensitive adhesive layer that exhibits pressure-sensitive adhesive properties at room temperature by curing, the foamed resin layer is cured by irradiating energy rays and simultaneously curing the foamed resin layer and the pressure-sensitive adhesive resin layer. Provided is a method for producing a foamed resin adhesive tape, wherein an adhesive tape having an adhesive layer laminated on at least one surface of the layer is formed at a time.

In the production method of the present invention, the foamed resin layer-forming resin and the adhesive resin layer used for the foamed resin layer are preferably made of a solventless energy ray-curable composition.
The foamed resin layer is a resin that exhibits adhesive performance at normal temperature by energy beam curing, or a foamed resin layer in which thermally foamed particles are mixed in a resin that solidifies without exhibiting adhesive performance, and adhesive at normal temperature by energy beam curing. It may be a laminate of a base material forming resin-only layer that solidifies without exhibiting performance.
Similarly, the adhesive resin layer can be multilayer-coated with at least two resin layers that become an adhesive layer after curing. The foamed resin layer and the adhesive resin layer can be multilayer-coated on a substrate having releasability (hereinafter referred to as a separator).
It is also possible to form a pressure-sensitive adhesive tape in which the both surfaces of the foamed resin layer are multi-layer coated so as to become the pressure-sensitive adhesive resin layer and the pressure-sensitive adhesive layer is laminated on both surfaces of the foamed resin layer at a time.
The present invention also provides a foamed resin pressure-sensitive adhesive tape having an adhesive layer laminated on at least one surface of a foamed resin layer, which is obtained by the above-described production method.
In the foamed resin pressure-sensitive adhesive tape of the present invention, the glass transition point after curing of the pressure-sensitive adhesive resin layer is preferably 20 ° C. or lower.

According to the present invention, a resin that exhibits adhesive performance at normal temperature by energy ray curing, or a foamed resin layer in which thermally foamed particles are mixed in a resin that solidifies without exhibiting adhesive performance, and adhesive at normal temperature by energy ray curing. Since the pressure-sensitive adhesive layer for forming the pressure-sensitive adhesive layer exhibiting performance is simultaneously polymerized and cured to form the pressure-sensitive adhesive layer and the foamed resin layer at the same time, the following effects are exhibited.
(1) The foamed resin double-sided pressure-sensitive adhesive tape can be produced by one processing.
(2) Adhesion is improved due to the easy formation of chemical bonds between the foamed resin layer and the adhesive layer and the anchoring effect of the adhesive layer on the foamed resin layer. Is eliminated, and as a result, the adhesive performance is improved.
(3) The thickness of the foamed resin layer and the pressure-sensitive adhesive layer can be freely set, and can meet a wide range of requirements. In addition, since a foamed resin layer having a large capacity is not manufactured in advance, a long foamed resin adhesive tape can be continuously produced, and productivity and yield are improved.

  Resin that develops adhesive performance at normal temperature by energy ray curing, or foamed resin layer in which thermally foamed particles are mixed in resin that solidifies without exhibiting adhesive performance, and adhesive that expresses adhesive performance at normal temperature by energy ray curing When a solvent-free energy ray curable resin composition is used as the adhesive resin layer for forming the layer, since no solvent is used, the generation of volatile organic compounds (VOC) leading to worsening of the working environment and air pollution Absent. Moreover, since aging (curing) at constant temperature is unnecessary, the time required for production can be shortened.

The present invention will be described below based on the best mode.
The method for producing a foamed resin pressure-sensitive adhesive tape of the present invention includes a resin layer that exhibits adhesive performance at room temperature by energy ray curing, or a foamed resin layer in which thermally foamed particles are mixed in a resin that solidifies without exhibiting adhesive performance, and energy. After the multilayer coating of the pressure-sensitive adhesive layer for forming the pressure-sensitive adhesive layer that expresses the pressure-sensitive adhesive performance at room temperature by wire curing, the foamed resin layer is cured by irradiating energy rays and simultaneously curing the foamed resin layer and the pressure-sensitive adhesive resin layer. A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer laminated on at least one side thereof is formed at a time.
The foamed resin layer is a resin that exhibits adhesive performance at normal temperature by energy beam curing, or a foamed resin layer in which thermally foamed particles are mixed in a resin that solidifies without exhibiting adhesive performance, and adhesive at normal temperature by energy beam curing. It may be a laminate of a base material forming resin-only layer that solidifies without exhibiting performance.

  Here, as a method of forming the foamed resin layer and the adhesive resin layer, multilayer coating on the separator can be preferably employed. In this case, a general adhesive tape can be obtained by coating at least one adhesive resin layer / foamed resin layer on the separator, and an adhesive resin layer / foamed resin layer / adhesive resin layer on the separator. If at least one layer is coated, a general double-sided pressure-sensitive adhesive tape is constructed. In the present invention, the number and thickness of the pressure-sensitive adhesive resin layer and the foamed resin layer are all flexible. The adhesive resin layer and / or the foamed resin layer can be made into a plurality of layers depending on the required function. The adhesive resin layer may be a multilayer coating of at least two resin layers that become an adhesive layer after curing.

  Examples of the separator include polycarbonate film, polyarylate film, polyethersulfone film, polysulfone film, polyester film, polyamide film, polyimide film, polystyrene film, polyolefin film, norbornene film, phenoxy ether type polymer film, and organic permeation resistance A release film having a release property with a silicone release agent or the like applied to a single-layer or multilayer plastic film such as a gas-resistant film and having a release property at least on one side; Release film that has release properties; Films that have release properties such as fluororesin films and certain polyolefin-based films; 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).

  A foamed resin layer in which heat-expanded particles are mixed in a resin that exhibits adhesive performance at room temperature by energy ray curing or a resin that solidifies without exhibiting adhesive performance is composed of an energy ray curable compound and a heat It can be formed by coating a resin composition containing expanded particles. Examples of the energy rays used for curing the foamed resin layer include heating and active energy rays (ultraviolet rays, electron rays, and in some cases, visible rays).

In the case of curing by heating, it is usual to add about 0.1 to 5% by weight of a polymerization initiator in advance with respect to the entire resin composition of the foamed resin 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 light, it is usual to blend a polymerization initiator of about 0.1 to 10% by weight with respect to the entire resin composition of the foamed resin 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 resin composition of the foamed resin layer may be blended with either a resin that exhibits adhesive performance at room temperature or a resin that does not exhibit adhesive performance after curing with energy rays.

  Examples of energy ray curable resins used in the foamed resin layer include monofunctional (meth) acrylate components such as alkyl acrylate and alkyl methacrylate; di-, tri- or poly (meth) acrylates of polyhydric alcohols and hydroxyalkyl (meth) Polyfunctional (meth) acrylate components such as acrylates; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl (meth) acrylate, N-methylolacrylamide, etc. Functional group-containing monomer component; vinyl acetate, styrene, acrylic urethane oligomer, and the like.

  The thermally foamed particles used in the thermally foamed resin layer include those in which a liquid or solid substance is microencapsulated at room temperature and those in which the substance is gasified by heat. Some include microcapsules of organic solvents. In addition, substances that are gasified by heat include inorganic and organic types, and examples of inorganic foaming agents include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, and azides. is there. On the other hand, organic foaming agents include water, halogenated fluorine compounds such as trichloromonofluoromethane and dichloromonofluoromethane, azo compounds such as azobisisobutyronitrile, azodicarbonamide, barium azodicarboxylate, and paratoluene. Hydrazine compounds such as sulfonyl hydrazide, diphenylsulfone-3,3′-disulfonyl hydrazide, 4,4′-oxybis (benzenesulfonyl hydrazide), allyl bis (sulfonyl hydrazide), P-toluylene sulfonyl semicarbazide and 4,4′- Semicarbazide compounds such as oxybis (benzenesulfonylsemicarbazide), triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole, N, N′-dinitrosopentamethylenetetrami And N, N'- dimethyl -N, N-nitroso compounds such as N'- dinitrosoterephthalamide, and the like.

  The mixing ratio of the resin used for the foamed resin layer (resin that exhibits adhesive performance at room temperature or resin that solidifies without exhibiting adhesive performance) and thermally foamed particles is determined by the required adhesive performance, thickness of the resin mixture, Although it should just determine suitably by a kind (thermal expansion coefficient) etc. and it does not specifically limit, About 5-200 weight part of thermally foamed particles are preferable with respect to 100 weight part of resin.

  For foaming of thermally foamed particles, a method of heating a resin mixture and then heating in a drying oven, a method of using heat generated during irradiation with energy rays or heat generated by a resin curing reaction, a method of using both of these, etc. However, the method of thermally foaming is not particularly limited.

As the resin for the adhesive resin layer, a fluid, solventless high viscosity resin composition is preferred. 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.

  Examples of monomer components containing functional groups include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, itaconic anhydride, maleic acid, maleic anhydride, fumaric acid, glycidyl (meth) acrylate, N-methylolacrylamide, and 2-hydroxy. Examples thereof include hydroxyalkyl (meth) acrylates such as ethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. 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, the polyfunctional (meth) It is preferred to add the acrylate in monomeric 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 urethane, polycarbonate, polyester, acrylic urethane, rubber, vinyl, silicone, etc. An adhesive grade resin composition can also be used.

  The viscosity of the resin composition of the adhesive resin layer is appropriately about 20 to 100000 cps / 20 ° C, preferably 20 to 80000 cps / 20 ° C, more preferably 20 to 12000 cps / 20 ° C.

In the method for producing a foamed resin pressure-sensitive adhesive tape of the present invention, at least two layers including a pressure-sensitive adhesive resin layer / a foamed resin layer are coated on a separator or other coated object, and the pressure-sensitive resin layer is irradiated with energy rays. By simultaneously curing the layer made of the foamed resin layer, a foamed resin pressure-sensitive adhesive tape having an adhesive layer on one side of the foamed resin layer is obtained. Further, in order to obtain a foamed resin double-sided adhesive tape having adhesive layers on both sides of the foamed resin layer, at least three layers including an adhesive resin layer / foamed resin layer / adhesive resin layer on a separator or other coated object The adhesive resin layer and the foamed resin layer may be cured at the same time by multilayer coating and irradiation with energy rays. 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.
In order to sufficiently foam the foamed resin layer, a heating step may be performed after the resin is multilayer coated and before the energy ray irradiation.
Thereby, the foamed resin adhesive tape by which the adhesive layer was laminated | stacked on the at least single side | surface of the foamed resin layer can be formed at once. The foamed resin pressure-sensitive adhesive tape produced as described above preferably has a glass transition point after curing of the pressure-sensitive adhesive resin layer of 20 ° C. or lower.

  The viscosity of the resin used for the foamed resin layer and the resin used for the adhesive resin layer may be the same or different. A foamed resin layer and an adhesive resin layer can be obtained in a lump by coating each layer and irradiating with energy rays before the layers are completely compatible with each other and foaming and curing. 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.

  The resin for the foamed resin layer and the adhesive resin layer may be applied using a known coating machine. Specifically, the substrate layer forming resin and the adhesive layer forming resin are applied to the release surface of the separator by gravure coating, die coating, kiss coating, bar coating, comma coating, reverse roll coating, etc., and then heated. The resin is cured by applying energy rays such as ultraviolet rays, electron beams, and visible light. If ozone or active oxygen is generated during irradiation with energy rays, it may hinder the curing of the resin. Therefore, after replacing the irradiation atmosphere with an inert gas such as nitrogen or covering the resin coated surface with a separator in advance By taking a method of irradiating energy rays, inhibition of curing of the resin can be avoided.

  The coating thickness of the resin is not particularly limited, but the foamed resin layer is preferably about 20 to 1000 μm, and is appropriately determined depending on the required adhesion performance, the thickness of the resin mixture, the type of thermal foamed particles (thermal expansion coefficient), and the like. Just decide. Moreover, the resin thickness of the adhesive resin layer is preferably about 1 to 100 μm, and more preferably about 4 to 50 μm from the viewpoint of adhesive properties and handling properties.

  The resin curing operation varies depending on the type and structure of the resin. If it is a heat-curing type, use a hot-air circulating oven or infrared irradiator. If it is an ultraviolet-curing type, a high-pressure mercury lamp, metal halide lamp, electrodeless ultraviolet irradiation A device or the like may be used. In the case of a visible light curable type, a light source such as a fluorescent lamp or an LED may be used. The amount of energy applied varies depending on the resin structure, the type / addition amount of the polymerization initiator / sensitizer, the type of energy beam irradiator, and the like. An appropriate curing method and curing conditions may be set while confirming the curing status of the resin.

  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 necessary.In the present invention, if a solventless resin is used, the dryer is Since it is not necessary, the entire equipment length from the feeding device to the winding device can be stored in a compact manner. In addition, since drying and aging at a constant temperature 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 object to be coated with the adhesive resin layer and the foamed resin layer is not necessarily a pressure-sensitive adhesive tape separator. For example, a stainless steel plate peeled with silicone or the like is used. A foamed resin pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer and a foamed resin layer can also be produced by performing multilayer coating and energy ray irradiation. In this case, after peeling off the foamed resin pressure-sensitive adhesive tape from the object to be coated, in order to protect the pressure-sensitive adhesive layer of the produced foamed resin pressure-sensitive adhesive tape, it may be bonded to a separator. Moreover, you may stick the foaming resin adhesive tape peeled off from the to-be-coated thing as it is to a to-be-adhered body.

  As described above, according to the method for producing a foamed resin pressure-sensitive adhesive tape of the present invention, thermally foamed particles are contained in a resin that exhibits adhesive performance at room temperature by energy ray curing, or in a resin that solidifies without exhibiting adhesive performance. The mixed foamed resin layer and the adhesive resin layer that exhibits adhesive performance at room temperature by energy ray curing are simultaneously polymerized and cured to form the adhesive layer and the foamed resin layer at the same time. It is possible to provide a method for producing a foamed resin pressure-sensitive adhesive tape that is excellent in adhesiveness with a layer, has a wide selection range of pressure-sensitive adhesive properties, is simple in production, and has excellent productivity.

  When a solvent-free energy ray curable resin composition is used as the resin for the foamed resin layer and the adhesive resin layer, no solvent is used, so that volatile organic compounds (VOC) that lead to deterioration of the work environment and air pollution are generated. There is almost no. For this reason, the expense and space for installing the equipment which collect | recovers and processes VOC can be reduced. In addition, since aging (curing) and drying at constant temperature 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.
Further, as a foamed resin layer, heat-expandable particles (Matsumoto Yushi) are used for 100 parts of energy curable resin composed of 20 parts of 2-ethylhexyl acrylate and 80 parts of urethane acrylate oligomer and 1 part of benzoin isobutyl ether as a photopolymerization initiator. 100 parts by weight of Matsumoto Microsphere F-36D (manufactured by Pharmaceutical Co., Ltd.) were mixed until evenly dispersed to prepare a paint.
Furthermore, a resin liquid comprising 20 parts of 2-ethylhexyl acrylate and 80 parts of urethane acrylate oligomer as an adhesive resin layer and 1 part of benzoin isobutyl ether as a photopolymerization initiator was prepared.

The release film (1) was simultaneously coated with three layers of adhesive resin layer (β) / foamed resin layer (α) / adhesive resin layer (β) so that the thickness was 25 μm / 500 μm / 25 μm. Thereafter, using a UV irradiation device in which the atmosphere was replaced with nitrogen gas, UV coating was performed under conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of 1000 mJ / cm ² to cure the coating layer. Thereafter, the release film (2) is bonded to the surface of the coating agent, and the release film (1) / adhesive resin layer (β) / foamed resin layer (α) / adhesive resin layer (β) / release film (2) layer. A foamed resin double-sided pressure-sensitive adhesive tape having a structure was obtained. The obtained foamed resin double-sided pressure-sensitive adhesive tape was a foamed resin double-sided pressure-sensitive adhesive tape in which foaming of the foamed resin layer was observed due to heat during ultraviolet irradiation and resin curing, and the total thickness without including a release film was 970 μm. It was.

(Example 2)
As a foamed resin layer, heat-expandable particles (Matsumoto Yushi Seiyaku Co., Ltd.) are used for 100 parts of energy curable resin consisting of 20 parts of 2-ethylhexyl acrylate and 80 parts of urethane acrylate oligomer and 1 part of benzoin isobutyl ether as a photopolymerization initiator. A paint A was prepared by mixing 100 parts by weight of Matsumoto Microsphere F-20D manufactured by company until it was uniformly dispersed. On the other hand, an energy curable resin coating B comprising 50 parts of 2-ethylhexyl acrylate and 50 parts of butyl acrylate as a resin for reinforcing the strength of the foamed resin layer and 3 parts of benzoin isobutyl ether as a photopolymerization initiator was prepared.
As the foamed resin layer, the release film (1) / adhesive resin layer (β) / foamed resin layer (paint A / paint B) / A foamed resin double-sided pressure-sensitive adhesive tape having a layer structure of pressure-sensitive adhesive resin layer (β) / release film (2) was obtained.

(Example 3)
The same pressure-sensitive adhesive resin layer (β) / foamed resin layer (α) / pressure-sensitive resin layer (β) as in Example 1 was formed on a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm subjected to peeling treatment on both sides, and the thickness was 25 μm / 500 μm. / 3 layers were simultaneously coated to a thickness of 25 μm. Thereafter, using a UV irradiation device in which the atmosphere was replaced with nitrogen gas, UV coating was performed under conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of 1000 mJ / cm ² to cure the coating layer. The obtained adhesive tape was wound around a tape to obtain a foamed resin double-sided adhesive tape.

Example 4
Using the same adhesive resin layer and foamed resin layer as in Example 1, the release film (1) was simultaneously coated with two layers of adhesive resin layer (β) / foamed resin layer (α) so that the thickness was 25 μm / 500 μm. . Thereafter, using a UV irradiation device in which the atmosphere is replaced with nitrogen gas, UV irradiation is performed under the conditions of an output of 120 W / cm, a lamp distance of 150 mm, and an integrated light quantity of 1000 mJ / cm ² to cure the coating layer, and a release film (1) / A foamed resin pressure-sensitive adhesive tape having a layer structure of pressure-sensitive adhesive resin layer (β) / foamed resin layer (α) was obtained. The foamed resin pressure-sensitive adhesive tape obtained was foamed by the foamed resin layer due to heat during UV irradiation and resin curing, and the pressure-sensitive adhesive layer on one side of the foamed resin having a total thickness of 930 μm without the release film It was the foaming resin single-sided adhesive tape which has.

(Comparative Example 1)
A foamed resin layer made of polyethylene having a thickness of 1000 μm was coated with the adhesive resin of Example 1 to a thickness of 25 μm, and then an ultraviolet irradiation device in which the atmosphere was replaced with nitrogen gas was used. Output 120 W / cm, lamp distance 150 mm, integration The coating layer was cured by irradiating with ultraviolet rays under conditions of a light quantity of 1000 mJ / cm ² . The adhesive resin surface was covered and protected with a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm. Thereafter, an adhesive layer was similarly provided on the opposite surface of the foamed resin layer made of polyethylene and protected with a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm to obtain a foamed resin double-sided adhesive tape.

(Comparative Example 2)
25 μm DRY with a foamed resin layer made of polyethylene having a thickness of 1000 μm and an acrylic two-component adhesive (100 parts of SK Dyne 801B manufactured by Soken Chemical Co., Ltd. and 2 parts of Coronate L-45 manufactured by Nippon Polyurethane Industry Co., Ltd.) And dried for 2 minutes in a 100 ° C. hot air circulating oven, and then the pressure-sensitive adhesive surface was covered and protected with a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm. Thereafter, an adhesive layer was similarly provided on the opposite surface of the foamed resin layer made of polyethylene and protected with a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm to obtain a foamed resin double-sided adhesive tape. The obtained tape was aged (cured) for 7 days at 40 ° C., and the adhesive was cured to obtain a foamed resin double-sided tape.

(Comparative Example 3)
A foamed resin double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Comparative Example 2 except that both sides of the foamed resin layer made of polyethylene having a thickness of 1000 μm were subjected to corona treatment.

(Comparative Example 4)
In Example 1, the resin used for the foamed resin layer (α) was used in the same manner as in Example 1 except that the heat-expandable particles were not mixed, and the release film (1) / adhesive resin layer (β) / An adhesive tape having a layer structure of resin layer (α ′) / adhesive resin layer (β) / release film (2), in which the resin layer (α ′) was not foamed, was obtained.

The above evaluation results are summarized in Table 1.
The evaluation method of each characteristic in Table 1 is as follows.

(Adhesive force)
The adhesive strength of the obtained foamed resin pressure-sensitive adhesive tape (in the case of Comparative Example 4, the pressure-sensitive adhesive tape in which the resin layer was not foamed) was bonded to the foamed resin pressure-sensitive adhesive tape by an adhesive strength measurement method according to JIS Z-0237. 180 degree peeling adhesive force after 1 hour is measured. In addition, when the obtained foamed resin adhesive tape was a foamed resin double-sided adhesive tape, the adhesive force was measured after bonding a 25-micrometer-thick biaxially-stretched polyethylene terephthalate film on one side.
(Adhesive adhesiveness)
About the sample after adhesive strength measurement, the test board (SUS304 steel plate) was visually observed for the presence or absence of adhesive residue, and the test sheet with no adhesive remaining on the test board was considered to have good adhesion.
(Number of processing)
The number of processings required for processing (resin coating, (drying), curing, and laminating separators) with a test coater is shown.

  As described above, the foamed resin pressure-sensitive adhesive tapes of Examples 1 to 4 can produce a tape with high adhesive force and good adhesion between the foamed resin layer and the pressure-sensitive adhesive by one processing. .

  On the other hand, in Comparative Examples 1 to 4, the number of times of processing becomes two, and the productivity is poor. In Comparative Examples 1 and 2 where the surface treatment was not performed on the foamed resin layer, the pressure-sensitive adhesive remained on the test plate, and the adhesion between the foamed resin layer and the pressure-sensitive adhesive was poor. Moreover, in the comparative example 4 which was not made to foam, adhesive force is low.

Claims (4)

  Resin that develops adhesive performance at normal temperature by energy ray curing, or foamed resin layer in which thermally foamed particles are mixed in resin that solidifies without exhibiting adhesive performance, and adhesive that expresses adhesive performance at normal temperature by energy ray curing After the multilayer coating with the adhesive resin layer for layer formation, the adhesive layer is applied to at least one surface of the foamed resin layer by irradiating energy rays and simultaneously curing the foamed resin layer and the adhesive resin layer. A method for producing a foamed resin pressure-sensitive adhesive tape, comprising forming a laminated pressure-sensitive adhesive tape at a time.   2. The pressure-sensitive adhesive tape in which both surfaces of the foamed resin layer are multilayer-coated so as to become the pressure-sensitive adhesive resin layer, and a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer laminated on both surfaces of the foamed resin layer is formed at a time. Manufacturing method of foamed resin adhesive tape.   A foamed resin pressure-sensitive adhesive tape obtained by the production method according to claim 1 or 2, wherein a pressure-sensitive adhesive layer is laminated on at least one surface of the foamed resin layer.   The foamed resin pressure-sensitive adhesive tape according to claim 3, wherein a glass transition point of the pressure-sensitive adhesive layer after curing is 20 ° C. or lower.