JP2011057882A - Method of manufacturing single pressure-sensitive adhesive layer laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing single pressure-sensitive adhesive layer laminated sheet capable of manufacturing a single sheet to which such a pressure-sensitive adhesive layer having a thickness of 100 μm or more as to be applicable for a shock-absorbing layer of a display is laminated and capable of reducing defective quality such as horizontal stripes or thickness irregularity of the pressure-sensitive adhesive layer. <P>SOLUTION: In the method of manufacturing single pressure-sensitive adhesive layer laminated sheet, a process (A) of applying a pressure-sensitive adhesive composition onto a long-size base material (a) continuously conveyed, a process (B) of drying or curing the pressure-sensitive adhesive composition applied on the long-size base material (a) to form the pressure-sensitive adhesive layer having a thickness of 100 μm or more and a process (C) of cutting a long-size laminated body made by laminating the pressure-sensitive adhesive layer onto the long-size base material (a) to single sheets are continuously performed on one manufacturing line, wherein the process (C) has a means for conveying the long-size laminated body (hereinafter, simply called as a conveyance means) and the conveyance means has a suction mechanism. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a single-sided pressure-sensitive adhesive layer laminated sheet, and in particular, from a step of applying a pressure-sensitive adhesive composition on a long substrate to a step of cutting into single sheets is carried out continuously on a single production line. The present invention relates to a method for producing a single-sided pressure-sensitive adhesive layer laminated sheet.

  It has been proposed to use an adhesive layer having a relatively large thickness as an impact absorbing layer for protecting a display such as a plasma display or a liquid crystal display from an impact (for example, Patent Documents 1 to 3).

  As a method for producing a relatively thick pressure-sensitive adhesive layer, for example, a pressure-sensitive adhesive layer having a thickness of 100 μm or more, further 200 μm or more, a method of applying a sheet to a sheet-like base material is common. is there. However, the above-mentioned single wafer coating method has a problem that it is inferior in productivity.

JP 2007-182557 A JP 2007-254705 A JP 2008-37943 A

  From the viewpoint of productivity, it is preferable to continuously apply the pressure-sensitive adhesive layer on the long base material. The long base material coated with the pressure-sensitive adhesive layer is usually wound into a roll. However, when a long base material coated with a large pressure-sensitive adhesive layer as described above is wound into a roll shape, the pressure-sensitive adhesive layer may be partially recessed due to the tension during winding, Inconveniences such as unevenness and unevenness of thickness may occur.

  In addition, the method of continuously applying the pressure-sensitive adhesive layer on the long base material and winding it into a roll requires a separate step of further cutting the obtained roll into a single sheet. Has the problem that it does not lead to significant productivity gains.

  Accordingly, in view of the above problems, an object of the present invention is to produce a single-sided pressure-sensitive adhesive layer laminated sheet in which a pressure-sensitive adhesive layer having a thickness of 100 μm or more that can be applied to a shock absorbing layer of a display is produced with high productivity. Another object of the present invention is to provide a method for producing a single-sided pressure-sensitive adhesive layer laminated sheet in which quality defects such as unevenness in the width and thickness of the pressure-sensitive adhesive layer are reduced.

The above object of the present invention has been basically achieved by the following invention.
(1) A method for producing a single-sided adhesive layer laminated sheet in which an adhesive layer having a thickness of 100 μm or more is laminated on a substrate,
The step (A) of applying the pressure-sensitive adhesive composition onto the continuously conveyed long base material (a), drying or curing the pressure-sensitive adhesive composition applied onto the long base material (a), The step (B) of forming a pressure-sensitive adhesive layer having a thickness of 100 μm or more, and the step (C) of cutting the long laminate in which the pressure-sensitive adhesive layer is laminated on the long base material (a) into single sheets, It is performed in the order of step (A), step (B), step (C),
The step (C) includes a unit for transporting the long laminate (hereinafter simply referred to as a transport unit), and the transport unit has a suction mechanism. Sheet manufacturing method.
(2) A step of continuously laminating the long base material (b) on the surface of the long base material (a) on which the adhesive layer is formed between the step (B) and the step (C). The manufacturing method of the adhesive layer laminated sheet of the sheet | seat as described in said (1) which has (D).
(3) The manufacturing method of the sheet | seat adhesive layer laminated sheet of the said (1) or (2) whose conveyance means which has the said suction mechanism is a suction conveyance belt.
(4) The manufacturing method of the sheet | seat adhesive layer laminated sheet in any one of said (1)-(3) whose cutting means of the said cutting process (C) is a laser.
(5) In the step (D), after the long base material (b) is bonded to the pressure-sensitive adhesive layer surface with the first nip roll, the second nip roll is pressed with a pressure higher than the first nip roll, ( The manufacturing method of the adhesive layer laminated sheet of the sheet | seat in any one of 2)-(4).

  ADVANTAGE OF THE INVENTION According to this invention, the sheet | seat sheet | seat with which the adhesive layer whose thickness which can be applied to the shock absorption layer of a display was 100 micrometers or more was laminated | stacked can be manufactured with sufficient productivity. Moreover, according to this invention, the horizontal unevenness and thickness nonuniformity of the adhesive layer of the adhesive layer laminated sheet of a sheet | seat can be reduced significantly.

It is one embodiment of this invention, Comprising: The schematic diagram which shows the flow of the whole manufacturing process. The top view which shows typically the cutting process of a elongate laminated body.

  The manufacturing method of the adhesive layer lamination sheet concerning this invention is the process (A) (henceforth a coating process (A) only) which coats an adhesive composition on the elongate base material (a) conveyed continuously. ), A step (B) of drying or curing the pressure-sensitive adhesive composition coated on the long substrate (a) to form a pressure-sensitive adhesive layer having a thickness of 100 μm or more (hereinafter simply referred to as a dry curing step (B) )), And a step (C) (hereinafter simply referred to as a cutting step (C)) of cutting a long laminate in which an adhesive layer is laminated on a long substrate (a) into a single sheet, A), the process (B), and the process (C) are performed in this order, and the cutting process (C) includes a transport unit having a suction mechanism for transporting the long laminate. In addition, it is preferable to carry out in order of a process (A), a process (B), and a process (C) in one manufacturing line continuously.

  A coating process (A) is a process of coating an adhesive composition on the elongate base material (a) conveyed continuously. In the coating step (A), the coating amount of the pressure-sensitive adhesive composition is set so that the thickness of the pressure-sensitive adhesive layer formed in the next drying and curing step (B) is 100 μm or more.

  The drying and curing step (B) is a step of forming a pressure-sensitive adhesive layer having a thickness of 100 μm or more by drying or curing the pressure-sensitive adhesive composition applied to the long base material (a) in the step (A).

  Depending on the composition and type (type) of the pressure-sensitive adhesive composition applied on the long base material (a), the drying and curing step (B) may be performed by any method of drying, curing, or a combination of drying and curing. Are appropriately selected and used. For example, in the case of a solvent-type pressure-sensitive adhesive composition, the pressure-sensitive adhesive layer is formed by drying, and in the case of an ultraviolet curable pressure-sensitive adhesive composition, it is cured by ultraviolet irradiation to form a pressure-sensitive adhesive layer, or a thermosetting pressure-sensitive adhesive. In the case of the agent composition, the pressure-sensitive adhesive layer is formed by heat curing. When the ultraviolet curable pressure-sensitive adhesive composition or the thermosetting pressure-sensitive adhesive composition contains a solvent, the pressure-sensitive adhesive layer is formed by a combination of drying and curing (the solvent is dried and then cured).

A cutting process (C) is a process of cut | disconnecting the elongate laminated body by which the adhesive layer was laminated | stacked on the elongate base material (a) into a sheet | seat. A cutting process (C) has a conveyance means for conveying a elongate laminated body, and this conveyance means has a suction mechanism.
FIG. 1 is an embodiment of the present invention, and is a schematic diagram showing the flow of the entire manufacturing process. Hereinafter, the coating step (A), the drying and curing step (B), and the cutting step (C) in the present invention will be described in detail with reference to FIG.

In the coating step (A), a pressure-sensitive adhesive composition (not shown) is applied by the coating device 2 on the long base material (a) 1 that is continuously conveyed. The long base material (a) 1 wound in a roll shape is unwound while being supported by the unwinding shaft 17, and is continuously conveyed by the conveying roller.
In the coating step (A), a known coating device such as a slit die coater, a blade coater, a gravure coater, or a roll coater is used as the coating device for coating the adhesive composition on the long substrate (a). be able to. Among these coating apparatuses, a slit die coater is preferably used from the viewpoint of uniformly coating a coating film having a thickness of 100 μm or more. The range of 0.3 to 10 m / min is appropriate for the coating speed (the conveying speed of (a) of the long base material).

  In the coating step (A), a plastic film is preferably used as the long substrate (a) to which the pressure-sensitive adhesive composition is applied. Examples of the resin constituting the plastic film include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as triacetyl cellulose, polyolefin resins such as polyethylene, polypropylene, and polybutylene, acrylic resins, polycarbonate resins, arton resins, and epoxy resins. , Polyimide resin, polyetherimide resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, and the like. Among these, a polyester resin, a polyolefin resin, and a cellulose resin are preferable, and a polyester resin is particularly preferably used.

  When applying the sheet adhesive layer laminated sheet obtained by the production method of the present invention as a member of a display filter for protecting the display, the long base constituting the sheet adhesive layer laminated sheet The material (a) can be used as a constituent member of a display filter as it is. In that case, the thickness of the long base material (a) is suitably in the range of 50 to 300 μm, and preferably in the range of 90 to 250 μm from the viewpoint of ensuring the rigidity of the display filter.

  Moreover, only the pressure-sensitive adhesive layer of the single-layer pressure-sensitive adhesive layer laminated sheet obtained by the production method of the present invention can be applied as one member of a display filter. In this case, the long base material (a) is preferably a release film.

  As the release film, a plastic film such as polyethylene, polypropylene, and polyethylene terephthalate can be used. The thickness of the release film is preferably in the range of 30 to 200 μm. The surface of the release film is preferably subjected to treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment in order to enhance the peelability from the pressure-sensitive adhesive layer.

  As the long base material (a), a material usually wound in a roll shape is used. The winding length is suitably about 50 to 2000 m.

  A well-known thing can be used as an adhesive composition concerning this invention. For example, acrylic, urethane, polyester, silicone, rubber-based pressure-sensitive adhesive compositions can be mentioned. Among these, acrylic and urethane-based pressure-sensitive adhesive compositions are preferable, and urethane-based pressure-sensitive adhesives are particularly preferable. Compositions are preferred.

  Moreover, although there exist types, such as a solvent type, an ultraviolet curable type, a thermosetting type, in an adhesive composition, any type of adhesive composition can be used for this invention. As the pressure-sensitive adhesive composition according to the present invention, an ultraviolet curable pressure-sensitive adhesive composition is particularly preferably used. As such an ultraviolet curable pressure-sensitive adhesive composition, an acrylic ultraviolet curable pressure-sensitive adhesive composition and a urethane-based ultraviolet curable pressure-sensitive adhesive composition are preferable, and a urethane-based ultraviolet curable pressure-sensitive adhesive composition is particularly preferable.

  Examples of the acrylic ultraviolet curable pressure-sensitive adhesive composition include those containing an acrylic polymer and a polymerizable monomer and / or polymerizable oligomer.

  As the acrylic polymer, for example, a (meth) acrylic acid ester polymer having (meth) acrylic acid ester (acrylic acid ester, methacrylic acid ester) as a main monomer component can be used. As the acrylic polymer, a polymer obtained by copolymerizing the monomer and a monomer having a carboxyl group or a hydroxyl group can be used. Furthermore, a polymerizable polymer having a polymerizable functional group (ethylenically unsaturated group) in the side chain can be used as the acrylic polymer. The weight average molecular weight of the acrylic polymer is preferably in the range of 10,000 to 500,000, and more preferably in the range of 20,000 to 400,000.

  The amount of the acrylic polymer used is preferably in the range of 30 to 95% by mass with respect to 100% by mass of the acrylic ultraviolet curable pressure-sensitive adhesive composition.

  Examples of the polymerizable monomer include (meth) acrylate compounds and vinyl compounds, such as diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and neopentyl glycol di (meth). Examples thereof include acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, divinylbenzene, vinyl adipate, and vinyl acrylate.

  Examples of the polymerizable oligomer include urethane oligomers, polyether oligomers, polyester oligomers, polycarbonate oligomers, and polybutadiene oligomers.

  The amount of the polymerizable monomer and / or polymerizable oligomer used (the total amount of both when the polymerizable monomer and the polymerizable oligomer are used together) ranges from 1 to 5 parts by mass with respect to 100 parts by mass of the acrylic polymer. Preferably, the range of 2-30 mass parts is more preferable.

  As described above, in the present invention, a urethane-based ultraviolet curable pressure-sensitive adhesive composition is particularly preferably used as the pressure-sensitive adhesive composition. Hereinafter, the urethane-based ultraviolet curable pressure-sensitive adhesive composition will be described.

  As such a urethane type ultraviolet curable adhesive composition, what has a urethane compound, for example, a urethane polymer and a urethane prepolymer (a urethane oligomer is included) as a main structural component is used preferably. Here, a urethane compound as a main constituent means that the urethane compound is contained in an amount of 50% by mass or more, preferably 60% by mass or more, with respect to 100% by mass of the urethane-based ultraviolet curable pressure-sensitive adhesive composition. Yes, more preferably 70% by mass or more, and the upper limit is about 98% by mass.

  Examples of the urethane compound include a urethane prepolymer having an ethylenically unsaturated group at the molecular terminal, a urethane polymer having a carboxy group or a hydroxyl group at the molecular terminal, or a urethane prepolymer. Here, the urethane prepolymer means a polymerizable urethane polymer.

  Examples of the urethane prepolymer having an ethylenically unsaturated group at the molecular end include urethane prepolymers having an ethylenically unsaturated group at one or both ends of the molecule, but having an ethylenically unsaturated group at both ends of the molecule. The urethane prepolymer having is preferably used. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acryl group, and a methacryl group. The weight average molecular weight of the urethane prepolymer is preferably in the range of 10,000 to 100,000, more preferably in the range of 2 to 80,000, and particularly preferably in the range of 2 to 50,000.

  The urethane polymer having a carboxy group or a hydroxyl group at the molecular end is a urethane polymer having a carboxy group or a hydroxyl group at one or both ends of the molecule, and a urethane polymer having a carboxy group or a hydroxyl group at both ends of the molecule is preferably used.

  Examples of the urethane prepolymer having a carboxy group or a hydroxyl group at the molecular end include a urethane prepolymer having a carboxy group or a hydroxyl group at one end of the molecule and an ethylenically unsaturated group at the other end.

  The weight average molecular weight of the urethane polymer or urethane prepolymer having a carboxy group or a hydroxyl group at the molecular end is preferably in the range of 10,000 to 100,000, more preferably in the range of 2 to 80,000, and particularly preferably in the range of 2 to 50,000. preferable.

  The urethane prepolymer having an ethylenically unsaturated group at the molecular end is described in detail in JP-A No. 2006-171261 and JP-A No. 2007-254705, and the compounds described in these patent references are described in detail. It can be used, or can be synthesized according to the synthesis methods described in these patent documents.

  The urethane polymer or urethane prepolymer having a carboxy group or a hydroxyl group at the molecular end is described in detail in JP-A-2007-254705, and the compounds described in this patent document can be used, or It can be synthesized according to the synthesis method described in this patent document.

  As a urethane compound, the above-mentioned urethane prepolymer (A) having an ethylenically unsaturated group at the molecular end, and the urethane polymer and / or urethane prepolymer (B) having a carboxy group or a hydroxyl group at the molecular end are combined. It is preferable to use it. The use ratio of the above (A) and (B) is a mass ratio, preferably in the range of 9: 1 to 1: 9, and more preferably in the range of 8: 2 to 2: 8. As a result, it is possible to form an adhesive layer having good adhesion to the substrate and excellent impact resistance.

  In an embodiment in which the urethane prepolymer (A) and the urethane polymer and / or the urethane prepolymer (B) are used in combination, the ultraviolet curable pressure-sensitive adhesive is synthesized by separately synthesizing the (A) and (B). When preparing the composition, both may be mixed, or the urethane prepolymer (C) containing the above (A) and (B) is synthesized in one synthesis process, and this urethane prepolymer (C) May be used for preparing an ultraviolet curable pressure-sensitive adhesive composition. The method for synthesizing the urethane prepolymer (C) is described in detail in JP-A-2007-254705, and can be incorporated into the present invention with reference to these.

  In the urethane prepolymer (C), the molecular terminal acrylate ratio is preferably 50 to 90% of all terminals. The molecular terminal acrylate ratio of the urethane prepolymer (C) is calculated from the acid value or hydroxyl value and molecular weight of the urethane prepolymer (C).

  In the urethane ultraviolet curable pressure-sensitive adhesive composition, it is preferable to use a (meth) acrylate compound or a vinyl compound as a polymerizable monomer.

  Examples of the polymerizable monomer include 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl hexahydroisophthalic acid, 2- (meth) acryloyloxyethyl hexahydroterephthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl isophthalic acid, 2- (meth) acryloyloxyethyl terephthalic acid, 2- (meth) acryloyloxyethyl succinic acid, (meta ) Acrylate, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, butanediol mono (meth) acrylate, 2 -Hydroxyethyl (me ) Caprolactone modified product of acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, glycidol di (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl acid Phosphate, phenyl (meth) acrylate, nonylphenol EO adduct (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) Acrylate, cyclononyl (meth) acrylate, cyclodecyl (meth) acrylate, cyclododecyl (meth) acrylate, cyclostearyl (meth) Chryrate, cyclolauryl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, phenoxy (meth) acrylate , Phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxy-polyethylene glycol (meth) acrylate, tricyclodecal (meth) acrylate, cyclopropyl (meth) acrylate, cyclobutyl (meth) acrylate, cyclopentyl (meth) acrylate , Bisphenol A type ethylene oxide addition (meth) acrylate, Water bisphenol A type ethylene oxide addition (meth) acrylate And divinylbenzene, vinyl adipate, and vinyl acrylate.

  The amount of the polymerizable monomer used is preferably in the range of 1 to 50% by mass and more preferably in the range of 2 to 30% by mass with respect to 100% by mass of the urethane ultraviolet curable pressure-sensitive adhesive composition.

  The ultraviolet curable pressure-sensitive adhesive composition described above preferably further contains a polymerization initiator. Commercially available products can be widely used as such polymerization initiators, but the following polymerization initiators are preferably used. For example, acetophenone series such as diethoxyacetophenone and benzyldimethyl ketal, benzoin ether series such as benzoin and benzoin methyl ether, benzophenone series such as benzophenone and methyl o-benzoylbenzoate, and hydroxy such as 1-hydroxy-cyclohexyl-phenyl-ketone Examples include alkylphenones, thioxanthones such as 2-isopropylthioxanthone and 2,4-dimethylthioxanthone, and amines such as triethanolamine and ethyl 4-dimethylbenzoate.

  The amount of the polymerization initiator used is suitably in the range of 0.05 to 5% by mass with respect to 100% by mass of the ultraviolet curable pressure-sensitive adhesive composition.

  In order to prevent yellowing, the pressure-sensitive adhesive composition according to the present invention preferably contains an antioxidant or a light stabilizer. As the antioxidant, a hindered phenol antioxidant and a phosphorus antioxidant are preferably used. As the light stabilizer, a monomer having a sterically hindered piperidyl group and an ethylenically unsaturated group is preferably used.

Moreover, additives, such as a plasticizer, a polymerization inhibitor, an antifoamer, a leveling agent, a ultraviolet absorber, a coloring inhibitor, and a pigment, can be contained in the adhesive composition concerning this invention.
The pressure-sensitive adhesive composition according to the present invention is preferably a UV-curable pressure-sensitive adhesive composition that does not substantially contain an organic solvent (so-called solventless type). Here, the fact that the ultraviolet curable pressure-sensitive adhesive composition does not substantially contain an organic solvent means that the amount of the organic solvent contained in 100% by mass of the ultraviolet curable pressure-sensitive adhesive composition is 5% by mass or less. The amount of the organic solvent is preferably 3% by mass or less, more preferably the amount of the organic solvent is 1% by mass or less, and particularly preferably no organic solvent is contained.

  The organic solvent is a highly volatile organic solvent such as methyl ethyl ketone, methyl isobutyl ketone, toluene, butyl acetate, ethanol, and methanol, and particularly an organic solvent having a boiling point of 130 ° C. or less.

  The organic solvent does not include a liquid polymerizable monomer (for example, a low-molecular acrylate monomer used as a reactive diluent).

  By making the ultraviolet curable pressure-sensitive adhesive composition solvent-free, safety and environmental performance in the production process are improved, and the residual solvent in the pressure-sensitive adhesive layer is greatly reduced.

  As described above, the pressure-sensitive adhesive composition coated on the long substrate (a) in the coating step (A) is dried or cured in the drying and curing step (B), and has a thickness of 100 μm or more. A layer is formed.

  In the dry curing step (B), as described above, any one of drying, curing, and drying + curing is appropriately selected depending on the composition and type (type) of the pressure-sensitive adhesive composition. As described above, in the present invention, a solventless ultraviolet curable pressure-sensitive adhesive composition is preferably used. Hereinafter, the aspect using the solventless type ultraviolet curable pressure-sensitive adhesive composition will be described in detail.

By using a solventless UV curable pressure-sensitive adhesive composition (hereinafter simply referred to as UV curable pressure-sensitive adhesive composition), drying can be substantially omitted in the drying and curing step (B). Only the pressure-sensitive adhesive layer can be formed.
The ultraviolet irradiation in the drying and curing step (B) may be cured by a single ultraviolet irradiation, or may be cured by intermittently irradiating ultraviolet rays. In the present invention, it is preferable that the ultraviolet curable pressure-sensitive adhesive composition is irradiated with ultraviolet rays intermittently. Here, intermittently irradiating ultraviolet rays means that ultraviolet rays are irradiated at least twice and a region where no ultraviolet rays are irradiated is provided between the first irradiation and the second irradiation. That is, in FIG. 1, a region M between the ultraviolet irradiation device 4 that performs the first ultraviolet irradiation and the ultraviolet irradiation device 5 that performs the second ultraviolet irradiation is a region where no ultraviolet irradiation is performed.

In the present invention, in order to form a pressure-sensitive adhesive layer having a thickness of 100 μm or more, the ultraviolet irradiation amount necessary for polymerization / curing of the ultraviolet-curable pressure-sensitive adhesive composition is a pressure-sensitive adhesive layer having a normal thickness (about 10 to 50 μm). Compared to, it becomes considerably large. When a large amount of ultraviolet light is irradiated by one time of ultraviolet irradiation, the temperature of the long base material (a) rises, and problems such as generation of wrinkles and deformation may occur.
The above problem can be improved by intermittently irradiating ultraviolet rays. That is, as described above, by providing the region M in which no ultraviolet rays are irradiated between the first ultraviolet irradiation and the second ultraviolet irradiation, the long base material (a) whose temperature is increased by the first ultraviolet irradiation is cooled. Thus, an excessive temperature rise due to the second UV irradiation can be avoided.

  The number of intermittent UV irradiations is suitably about 2 to 5 times, preferably 2 to 3 times. The region M not irradiated with ultraviolet rays is preferably set as appropriate depending on the conveying speed of the long base material (a) coated with the ultraviolet curable pressure-sensitive adhesive composition and the number of times of ultraviolet irradiation. For example, when the number of times of UV irradiation is 2 to 3, the time required for passing the long base material (a) coated with the UV curable pressure-sensitive adhesive composition through the region M where the UV light is not irradiated. It is preferable to design for 20 to 120 seconds, preferably 30 to 90 seconds.

  The ultraviolet ray used in the drying and curing step (B) is preferably an ultraviolet ray having a wavelength of 200 to 400 nm. For example, a lamp emitting ultraviolet rays such as a high pressure mercury lamp, a low pressure mercury lamp, or a metal halide lamp is used.

Dose of ultraviolet in the drying-curing step (B) is set as appropriate by the thickness of the pressure-sensitive adhesive layer formed is preferably in the range of 500~4000mJ / cm ² in accumulated light quantity, the range of 800~3500mJ / cm ² Is more preferable, and the range of 1000 to 3000 mJ / cm ² is particularly preferable.

  In the drying and curing step (B), the ultraviolet irradiation is preferably performed in an atmosphere having an oxygen concentration of 5000 ppm or less, more preferably 3000 ppm or less, and particularly preferably 1000 ppm or less. This accelerates the polymerization reaction of the ultraviolet curable pressure-sensitive adhesive composition. The oxygen concentration is preferably low from the viewpoint of promoting the polymerization reaction, but the substantial lower limit is about 50 ppm from the economical viewpoint.

  As a method of reducing the oxygen concentration, a method of injecting an inert gas such as nitrogen gas and replacing it with oxygen is preferably used. In this case, it is preferable to seal as much as possible so that outside air does not enter the ultraviolet irradiation device, and to blow an inert gas such as nitrogen gas in the device to reduce the oxygen concentration.

  As described above, in the case of intermittently irradiating ultraviolet rays, even if a plurality of ultraviolet irradiation devices are installed, it is preferable to set the oxygen concentration to a low value as described above.

  In the dry curing step (B), a pressure-sensitive adhesive layer having a thickness of 100 μm or more is formed on the long base material (a) as described above.

  The single-sided pressure-sensitive adhesive layer laminated sheet or pressure-sensitive adhesive layer obtained by the production method of the present invention is suitable as a shock-absorbing layer for a filter for display, and from the viewpoint of improving impact resistance, the thickness of the pressure-sensitive adhesive layer is 200 μm or more is preferable, and 300 μm or more is more preferable. The upper limit of the thickness of the pressure-sensitive adhesive layer is preferably 2000 μm or less, and more preferably 1000 μm or less, from the viewpoint of productivity such as coating suitability of the pressure-sensitive adhesive composition and drying / curing speed. Moreover, since the visibility of the display image of a display will deteriorate when the thickness of an adhesive layer is too large, 2000 micrometers or less are preferable and the upper limit of the thickness of an adhesive layer is more preferable 1000 micrometers or less also from the viewpoint.

  The long laminate obtained by forming a pressure-sensitive adhesive layer having a thickness of 100 μm or more on the long substrate (a) in the drying and curing step (B) is continuously conveyed to the cutting step (C) and continuously. Is cut into pieces. The cutting step (C) includes a conveying unit having a suction mechanism for conveying the long laminate and a cutting unit. Here, the transport means having the suction mechanism has a role of transporting the long laminate to the cutting device.

  The conveying means having the suction mechanism is to convey the surface opposite to the surface on which the pressure-sensitive adhesive layer of the long laminate is laminated with the suction mechanism. As a conveying means having a suction mechanism, a suction conveying belt is preferably used.

  FIG. 1 shows a mode in which a suction conveyance belt is used as a conveyance means having a suction mechanism. The long laminate 9 is conveyed while being adsorbed by the suction conveyance belt 13 and is cut into single sheets by the cutting device 10. The suction conveyance belt 13 is provided with a plurality of suction holes (not shown) in the conveyance belt, and the long laminated body 9 is adsorbed to the suction conveyance belt 13 by suction from the suction holes via the suction box 15. Then transported.

  In the case where the transport means in the cutting step (C) is a normal transport roll, when the long laminate 9 is cut into single sheets by the cutting device 10, a phenomenon occurs in which the long laminate temporarily returns. Due to the influence, the coating property of the pressure-sensitive adhesive composition in the coating step (A) deteriorated, causing a problem of uneven horizontal steps. This problem was solved by using a conveying means having a suction mechanism.

  In addition, the above problem can be solved by applying a certain nip pressure using a nip roll as a conveying means in the cutting step (C), but the lateral unevenness and thickness unevenness of the adhesive layer due to the nip pressure are newly added. A problem that occurred.

  The conveyance speed of the conveyance means having the suction mechanism is in the range of 0.05 to 0.2% in terms of the draw ratio with respect to the conveyance speed of the master roll (backup roll) 18 that determines the conveyance speed of the manufacturing process of the present invention. Increasing the thickness is preferable, and this can further reduce the occurrence of the unevenness in the horizontal step and the unevenness in thickness.

  As the cutting means in the cutting step (C), a laser is preferable. A cutter blade such as a rotary cutter can also be used, but in order to continuously and stably cut a pressure-sensitive adhesive layer having a thickness of 100 μm or more, it is cut in a non-contact manner on a long laminate on which the pressure-sensitive adhesive layer is laminated. Lasers that can be used are preferred. Since the adhesive component adheres to the cutter blade during cutting, it may not be able to be repeatedly cut for a long time.

Hereinafter, a cutting method using a laser cutting device will be described.
The long laminate 9 is cut in a direction substantially perpendicular to the conveying direction of the long laminate 9 and processed into a single-layer adhesive layer laminate sheet 11. When applied to a display filter, the shape of the single-sided pressure-sensitive adhesive layer laminated sheet is usually rectangular or square. In order to obtain an adhesive layer laminated sheet having a rectangular or square shape, it is necessary to cut it almost perpendicularly to the conveying direction of the long laminate 9.

Therefore, in order to obtain a rectangular or square sheet of adhesive layer laminated sheet, the laser cutting is performed by a laser head at a predetermined angle with respect to an axis perpendicular to the conveying direction of the long laminated body 9 being conveyed. It is necessary to move to cross.
FIG. 2 is a plan view schematically showing a cutting process of the long laminate. An arrow X indicates the transport direction of the long laminate 9, and the laser head 12 cuts the long laminate 9 while moving at an angle θ with respect to an axis Y orthogonal to the transport direction. Symbol Z is a moving line of the laser head.
The angle θ is appropriately set according to the conveying speed of the long laminate 9 and the moving speed of the laser head 12. It is preferable that the moving speed of the laser head 12 is set to be twice or more the conveying speed of the long laminate 9. This is preferable because the angle θ is reduced and the installation space for the laser cutting device can be reduced. The angle θ is preferably in the range of 5 to 40 degrees, and more preferably in the range of 10 to 30 degrees.

  In the manufacturing method of the present invention, in the cutting step (C), the cutting operation of the long laminated body 9 is repeatedly performed at a predetermined interval, so that the laser head 12 is initialized after moving for cutting the long laminated body 9. It is necessary to return to the position and prepare for the next cut. The moving speed for cutting the laser head 12 and the return speed to the initial position are preferably set to be the same from the viewpoint of simplifying the equipment.

  In the cutting step (C), when the long laminate 9 conveyed at a constant speed is repeatedly cut into a single-sized adhesive layer laminated sheet of a predetermined size, for example, a single-sized adhesive layer laminated sheet having a small size In the case of repeated cutting, the interval between cutting becomes shorter, so that the moving speed and the returning speed of the laser head 12 need to be increased with respect to the conveying speed of the long laminate 9. That is, as described above, it is preferable that the moving speed of the laser head 12 is increased to 2 times or more, more preferably 3 times or more with respect to the moving speed of the long laminate 9. On the other hand, when the moving speed of the laser head 12 is increased, in order to cut the long laminate 9 in which the pressure-sensitive adhesive layer having a thickness of 100 μm or more is cut, it is necessary to greatly increase the output of the laser. However, it is preferable to adjust the moving speed of the laser head 12 in the range of 1 to 20 m / min.

  In the present invention, the transport speed of the long laminate 9 (same as the transport speed of the long base material (a) and the coating speed of the pressure-sensitive adhesive composition) is suitably in the range of 0.3 to 10 m / min. The range of 1 to 5 m / min is preferable as described above. For example, the conveying speed of the long laminate 9 is 1 m / min, and the moving speed of the laser head 12 is three times the conveying speed of the laminate. When it is set to 3 m / min, the moving angle θ of the laser head 12 is 19.47 degrees.

In the cutting step (C), the laser output source used in the laser cutting apparatus includes iodine, semiconductor, YAG, CO _{2 and the} like, and a CO ₂ laser is particularly preferably used.

  In the cutting step (C), the long laminate 9 is cut into single sheets, and the single-layer adhesive layer laminated sheet 11 is manufactured. The conveying means for conveying the single-sided adhesive layer laminated sheet 11 is preferably a conveying means having a suction mechanism. In FIG. 1, a suction conveying belt 14 is used. The structure of the suction conveyance belt 14 is the same as that of the suction conveyance belt 13.

  In the cutting step (C), by using a suction conveying belt as the conveying means 13 for the long laminated body 9 and the conveying means 14 for the single-sided adhesive layer laminated sheet 11, the long laminated body 9 and the single wafer immediately after cutting are used. It is possible to prevent the cut end of the pressure-sensitive adhesive layer laminated sheet 11 from jumping up.

  In the production method of the present invention, the long base material (b) is continuously applied to the surface on which the adhesive layer of the long base material (a) is formed between the drying and curing step (B) and the cutting step (C). Preferably, a step (D) of laminating is provided. The long base material (b) has a role of protecting the pressure-sensitive adhesive layer. By laminating the long base material (b) on the pressure-sensitive adhesive layer, it is possible to prevent the vaporized matter generated when cutting with the laser cutting device in the cutting step (C) from re-adhering to the pressure-sensitive adhesive layer. Thus, it becomes possible to stack and accumulate the single-sided adhesive layer laminated sheets produced by cutting.

  Hereinafter, the step (D) will be described with reference to FIG. In the step (D), the long base material (b) 6 is supplied in a roll shape, continuously unwound, and continuously on the pressure-sensitive adhesive layer formed on the long base material (a). Bonded. Here, the bonding of the pressure-sensitive adhesive layer and the long base material (b) is performed in a two-stage nip using nip rolls 7 and 8, but may be performed in a one-stage nip.

  In the present invention, since the long base material (b) is continuously pasted and laminated on the pressure-sensitive adhesive layer having a large thickness of 100 μm or more, it is preferably pasted in a two-stage nip. When bonding with a relatively large nip pressure in a one-stage nip, the thickness of the pressure-sensitive adhesive layer is as large as 100 μm or more in the present invention, so that nip unevenness and wrinkles may occur. These problems can be remedied by employing a two-stage nip, making the nip pressure of the first nip roll relatively small, and making the nip pressure of the second nip roll greater than the nip pressure of the first nip roll.

  Specifically, the nip pressure of the first nip roll is preferably 1.0 kgf / cm or less, and the nip pressure of the second nip roll is preferably 1.1 kgf / cm or more. More specifically, the nip pressure of the first nip roll is preferably in the range of 0.2 to 1.0 kgf / cm, more preferably in the range of 0.3 to 0.9 kgf / cm, and 0.4 to 0. A range of .8 kgf / cm is particularly preferred. The nip pressure of the second nip roll is preferably in the range of 1.1 to 3.0 kgf / cm, more preferably in the range of 1.2 to 2.5 kgf / cm, and in the range of 1.3 to 2.0 kgf / cm. Particularly preferred.

  A known nip roll can be used as the nip roll. For example, a nip roll in which a metal roll and a rubber roll are combined is preferably used. In this case, it is preferable to arrange the rubber roll on the long substrate (b) side.

  The long base material (b) in the step (D) is preferably a plastic film, and the same plastic film as the long base material (a) can be used. Further, the long base material (b) may be a release film in the same manner as the long base material (a).

  Step (D) can also be provided before curing by ultraviolet irradiation, which is one aspect of the drying and curing step (B). In this case, when the ultraviolet curable pressure-sensitive adhesive composition coated on the long base material (a) is irradiated with ultraviolet rays, the ultraviolet curable pressure-sensitive adhesive composition is coated with the long base material (b). Since oxygen is blocked, there is an advantage that it is not necessary to blow nitrogen gas to remove oxygen that inhibits the polymerization reaction. However, after coating an ultraviolet curable pressure-sensitive adhesive composition having a thickness of 100 μm or more on the long base material (a), another long base material (b) is not irradiated with ultraviolet light (that is, before curing). If it laminates | stacks, it will become easy to generate | occur | produce problems, such as thickness nonuniformity arising in a coating surface, or thickness accuracy falling by the bonding pressure at the time of bonding another elongate base material (b).

Therefore, for the above reasons, the step (D) is preferably provided between the dry curing step (B) and the cutting step (C).
In the production method of the present invention, the step (E) of heating the pressure-sensitive adhesive composition coated on the long base material (a) is further performed between the coating step (A) and the dry curing step (B). It is preferable to provide it.

  As described above, the pressure-sensitive adhesive composition according to the present invention is preferably a solventless UV-curable pressure-sensitive adhesive composition. By making the ultraviolet curable pressure-sensitive adhesive composition solvent-free, safety and environmental performance in the production process are improved, and the residual solvent in the pressure-sensitive adhesive layer is greatly reduced.

  An advantage of using the ultraviolet curable pressure-sensitive adhesive composition is that it can be a solvent-free type. However, since it is a solventless type, the viscosity of the composition tends to increase, and the increase in viscosity leads to deterioration of the coating property, and the occurrence of dents due to the uniformity of the coating film thickness and bubbles. It becomes easy. In particular, when the thickness of the pressure-sensitive adhesive layer is 100 μm or more, the above problem tends to be promoted.

  When using a solvent-free UV curable pressure-sensitive adhesive composition, drying or heating to evaporate the solvent is usually not performed after coating, but a solvent-free UV curable pressure-sensitive adhesive composition is applied. Thereafter, the above-described problems are improved by heating.

  The heating temperature in the step (E) is preferably 28 ° C. or higher, more preferably 30 ° C. or higher, and particularly preferably 33 ° C. or higher. The upper limit of the heating temperature is preferably 60 ° C. or less, and more preferably 50 ° C. or less. Here, the heating temperature is the surface temperature of the ultraviolet curable pressure-sensitive adhesive composition applied to the long substrate (a). The heating temperature of the UV curable pressure-sensitive adhesive composition is within 5 cm immediately after the long base material (a) coated with the composition is carried out of the heating step (the transport distance of the long base material (a) is within 5 cm) ) To measure. In addition, if the conveyance speed is about 0.3 to 10 m / min, the surface temperature of the ultraviolet curable pressure-sensitive adhesive composition at a position within 5 cm after unloading from the heating process is said to have been unloaded from the heating process. It is estimated that the surface temperature does not substantially decrease and is the same as the surface temperature of the ultraviolet curable pressure-sensitive adhesive composition in the heating step. The surface temperature can be measured using, for example, a non-contact type infrared surface thermometer.

  In the step (E), it is important to increase the temperature of the ultraviolet curable pressure-sensitive adhesive composition coated on the long base material (a), and the surface temperature of the ultraviolet curable pressure-sensitive adhesive composition immediately after coating. The temperature is preferably increased by 3 ° C. or more, particularly preferably 5 ° C. or more. The upper limit of the surface temperature rise is about 15 ° C. The temperature of the ultraviolet curable pressure-sensitive adhesive composition applied here means the surface temperature as described above.

  The application of the pressure-sensitive adhesive composition is usually performed at room temperature. Also in the present invention, the pressure-sensitive adhesive composition is applied at a room temperature of 20 to 27 ° C. Therefore, the surface temperature of the composition immediately after being applied to the long substrate (a) is also about 20 to 27 ° C., and by heating this in the step (E), the surface temperature of the pressure-sensitive adhesive composition is reduced. Raise.

  The step (E) can be shortened and shortened compared with the drying step aiming at evaporation of the solvent of the conventional solvent-type pressure-sensitive adhesive composition, and the influence on productivity is slight. The heating time in the step (E) is suitably about 30 to 200 seconds, and preferably in the range of 30 to 150 seconds.

  A conventionally known method can be used as the heating method in the step (E). For example, a method of blowing hot air, a method using infrared rays, a method using microwaves, a method using heating rolls, and the like can be given. Among these, a method using infrared rays is preferably used, and far infrared rays are particularly preferably used.

Examples will be specifically described below, but the present invention is not limited to these examples.
Example 1
By the manufacturing method shown in FIG.1 and FIG.2, 200 sheet | seat adhesive layer lamination sheets of width 700mm x length 900mm were manufactured continuously. Each member and manufacturing conditions used in this example are as follows.
<Details of each member>
<Long base material (a)>
An optical PET film (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) having a thickness of 100 μm, having a width of 700 mm and a winding length of 500 m.
<Long base material (b)>
A release PET film having a thickness of 75 μm (Therapeutic (registered trademark) MD manufactured by Toray Film Processing Co., Ltd.), having a width of 700 mm and a winding length of 500 m.
<Solvent-free UV-curable adhesive composition>
A urethane-based ultraviolet curable pressure-sensitive adhesive composition was prepared as follows.
First, a urethane prepolymer (C) having a weight average molecular weight of 38000 was synthesized according to Synthesis Example 8 of JP-A-2007-254705. This urethane prepolymer (C) is a urethane prepolymer containing a urethane prepolymer (A) having an ethylenically unsaturated group at the molecular terminal and a urethane prepolymer (B) having a hydroxyl group at the molecular terminal.

Next, 88 parts by mass of the urethane prepolymer (C), 10 parts by mass of 4-hydroxybutyl acrylate as a reactive diluent (polymerizable monomer), 2 parts by mass of dibutyl phthalate as a plasticizer, a hindered phenol type 1 part by mass of triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate as an antioxidant and 0.5 part by mass of triphenyl phosphite as a phosphorus-based antioxidant , 0.5 part by mass of 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine] as a monomer having a sterically hindered piperidyl group and an ethylenically unsaturated group, and polymerization initiation Hydroxyalkylphenone-based photopolymerization initiator (manufactured by Ciba Geigy, Irgacure 184, hereinafter referred to as IC184) The ultraviolet-curable pressure-sensitive adhesive composition was prepared by uniformly mixed with 0.5 parts by weight.
<Production conditions>
<Process (A)>
1) Conveying speed of long base material (a): 1 m / min However, the conveying speed of the long base material (a) is the coating speed of the UV curable pressure-sensitive adhesive composition, and the conveying speed of the long laminate. Is the same.
2) Coating device; slit die coater 3) coating thickness of UV curable pressure-sensitive adhesive composition; the thickness of the formed pressure-sensitive adhesive layer was adjusted to 500 μm.
<Process (E)>
The surface temperature of the ultraviolet curable pressure-sensitive adhesive composition immediately after coating was raised to 30 ° C. by infrared irradiation with respect to 23 ° C.
<Process (B)>
Ultraviolet rays were irradiated using ultraviolet irradiation devices 4 and 5. In the ultraviolet irradiation light amount of the device 4 is 1000 mJ / cm ^2, light quantity of the ultraviolet irradiation device 5 is 800 mJ / cm ^2, accumulated light quantity was 1800 mJ / cm ^2. Nitrogen gas was injected so that the oxygen concentrations in the ultraviolet irradiation devices 4 and 5 were 300 ppm each. The time required to pass through the region M where the ultraviolet rays were not irradiated between the ultraviolet irradiation devices 4 and 5 was 60 seconds.
<Process (D)>
The nip pressure of the nip roll 7 is 0.5 kgf / cm, and the nip pressure of the nip roll 8 is 1.6 kg / cm.
<Process (C)>
A CO ₂ laser was used. The moving speed of the laser head was set to 3 m / min, and the moving angle θ was set to 19.47 degrees.
<Evaluation of single-layer adhesive sheet laminated sheet>
Ten sheets were randomly taken out from 200 sheets of the pressure-sensitive adhesive layer laminated sheet produced as described above, and each release PET film was peeled off and attached to a display panel of a plasma display. Subsequently, the display panel was observed from all angles, and the influence on the visibility due to the unevenness in the horizontal direction of the pressure-sensitive adhesive layer and the variation in thickness was visually observed and evaluated according to the following criteria.
○: All 10 sheets are good.
X: Concavities and convexities are visually recognized in at least one of the ten sheets depending on the viewing angle.
<Evaluation results>
The single-sided pressure-sensitive adhesive layer laminated sheet produced in Example 1 was ○.

(Comparative Example 1)
In the production method of Example 1, a single-sided pressure-sensitive adhesive layer laminated sheet was produced in the same manner as in Example 1 except that a normal conveyance roll was used as the conveyance means in the cutting step (C).

  As a result of evaluation in the same manner as in Example 1, it was ×.

(Comparative Example 2)
In the production method of Example 1, a single-sided pressure-sensitive adhesive layer laminated sheet was produced in the same manner as in Example 1 except that a nip roll was used as the conveying means in the cutting step (C).

  As a result of evaluation in the same manner as in Example 1, it was ×.

1 Long base material (a)
2 Coating device 3 Heating device 4, 5 Ultraviolet irradiation device 6 Long base material (b)
7, 8 Nip rolls 9 Long laminate 10 Cutting device 11 Single-layer adhesive layer laminate sheet 12 Laser head 13 Conveying means (suction carrier belt) of long laminate
Conveying means (suction conveying belt) for 14 sheets of adhesive layer laminated sheet
15, 16 Suction box 17 Unwinding shaft 18 of long base material (a) 18 Master roll (backup roll)
M Area not irradiated with ultraviolet rays X Transport direction Y of the long laminate The orthogonal axis Z with respect to the transport direction of the long laminate The movement line θ of the laser head The movement angle of the laser head with respect to the orthogonal axis Y

Claims (5)

A method for producing a single-sided pressure-sensitive adhesive layer laminated sheet in which a pressure-sensitive adhesive layer having a thickness of 100 μm or more is laminated on a substrate,
The step (A) of applying the pressure-sensitive adhesive composition onto the continuously conveyed long base material (a), drying or curing the pressure-sensitive adhesive composition applied onto the long base material (a), The step (B) of forming a pressure-sensitive adhesive layer having a thickness of 100 μm or more, and the step (C) of cutting the long laminate in which the pressure-sensitive adhesive layer is laminated on the long base material (a) into single sheets, It is performed in the order of step (A), step (B), step (C),
The step (C) includes a unit for transporting the long laminate (hereinafter simply referred to as a transport unit), and the transport unit has a suction mechanism. Sheet manufacturing method.   Step (D) of continuously laminating the long base material (b) on the surface on which the pressure-sensitive adhesive layer of the long base material (a) is formed between the step (B) and the step (C). The manufacturing method of the adhesive layer laminated sheet of the sheet | seat of Claim 1 which has these.   The method for producing a single-sided pressure-sensitive adhesive layer laminated sheet according to claim 1, wherein the transport means having the suction mechanism is a suction transport belt.   The manufacturing method of the adhesive layer laminated sheet of the sheet | seat in any one of Claims 1-3 whose cutting means of the said cutting process (C) is a laser.   The said process (D) WHEREIN: After sticking a elongate base material (b) on the adhesive layer surface with a 1st nip roll, it pressurizes with a pressure larger than a 1st nip roll with a 2nd nip roll. The manufacturing method of the adhesive layer laminated sheet of the sheet | seat in any one of.

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