TW201732004A - Adhesive tape - Google Patents

Abstract

Disclosed is an adhesive tape having a laminated substrate and an adhesive layer 5 on at least one side of the laminated substrate, wherein a laminate comprising at least one black print layer 2 on a support 1 and a laminate comprising at least one light colored print layer 3 on a support 1 are bonded to each other on each print layer side via an adhesive layer 4 to form the laminated substrate. The blocking of the laminated substrate and the pinhole caused by peeling of the print layers hardly occur, the properties such as adhesive force can be easily adjusted, the reworkability is excellent, and for example, a silicone based adhesive layer can be easily applied.

Description

Adhesive tape

The present invention relates to a liquid crystal (LCD) display device used in, for example, a mobile device, and a single-sided or double-sided adhesive tape which is used between a backlight frame and an LCD module and has both light reflectivity and light blocking properties.

For example, a liquid crystal display device used in an image display device such as a mobile communication terminal, a tablet computer, a car navigation, or a mobile game machine is provided with an adhesive tape between the liquid crystal display unit and the backlight unit, thereby fixing the two members. Further, the adhesive tape has, for example, a white light-reflecting layer and a black light-shielding layer, and contributes to improvement in luminance of the backlight surface and prevention of deterioration in visibility due to light leakage from the backlight. Such an adhesive tape which contributes to both the improvement of the brightness and the light-shielding property is disclosed, for example, in Patent Documents 1 to 6.

The light-reflecting layer of the adhesive tape disclosed in Patent Document 1 is composed of a biaxially stretched resin film of a polyester resin containing a white colorant. However, such a light-reflecting layer composed of a resin film containing a coloring agent is inferior in productivity, and adjustment of brightness (reflectance) is also difficult.

The light-reflecting layer of the adhesive tape disclosed in Patent Document 2 belongs to a white printed layer, and the light-shielding layer belongs to a black printed layer. The printed layer is superior in productivity and brighter in brightness (reflectance) than the resin film containing the colorant. Therefore, it is disclosed that both the white printed layer and the black printed layer are disposed on one side of the transparent plastic substrate. The laminated substrate has a laminated substrate in which a white printed layer is provided on one side of the transparent plastic substrate and a black printed layer is provided on the other side. However, when the laminated substrate is wound in a roll form, adhesion occurs between the printed layer and its contact surface, and when the next step (adhesive coating step) is performed to rewind, there is a printed layer therein. A part of the contact surface is left in a spot shape.

The adhesive tape disclosed in Patent Document 3 is provided with a thin coating layer composed of a synthetic rubber, an acrylic resin or a polyester resin on a laminated base material composed of a black printed layer/resin film/white printed layer, and is interposed therebetween. The thin coating layer is wound to prevent adhesion and peeling of the printed layer. However, since one of the printing surfaces is exposed, when the adhesive coating portion is conveyed, the printing layer is in close contact with a driving roller, a guide roller or a conveyor made of a material such as rubber, resulting in the printing layer being on the substrate. Peeling off makes the place a pinhole, which may cause a decrease in light blocking property or light reflectivity.

The problem caused by peeling off the printed layer due to the peeling of the printed layer causes a problem when the adhesive tape is peeled off from the member such as the LCD panel and the re-attaching operation (rework) is performed. In the adhesive tape of Patent Document 4, in order to improve the adhesion between the substrate and the printed layer, an intermediate layer containing synthetic rubber is provided between the substrate and the printed layer. Thereby, when rework is performed, interlayer peeling between the substrate and the printed layer can be prevented, and the printed layer and the adhesive layer can be prevented from remaining on the member. On the other hand, in the adhesive tape disclosed in Patent Document 5, in order to improve the adhesion between the printing layer and the adhesive layer, the binder resin of the printing layer is a polyurethane resin having a Tg (tan δ peak temperature) of -30 ° C to 30 ° C. And the hardener is an aliphatic or alicyclic isocyanate which prevents cracking of the printed layer and causes breakage of the tape when rework is performed.

However, the adhesive tape disclosed in Patent Document 4 and Patent Document 5, because the adhesive layer directly contacts the printing layer, is between the adhesive component and the printed layer component. When there is an interaction, there is a situation in which the desired adhesion is not obtained. For example, the adhesive tape disclosed in Patent Document 4 describes that an acrylic adhesive is blended as needed in an acrylic adhesive. In this case, the cross-linking agent added to the adhesive is absorbed by the printed layer, resulting in a decrease in the degree of hardening of the adhesive, which may result in a higher adhesive force than the preset value of the product design. Moreover, in the adhesive tape disclosed in Patent Document 5, the hardener contained in the adhesive of the printing layer migrates into the adhesive layer, resulting in an increase in the degree of hardening of the adhesive, which may cause the adhesion to be lower than the preset value of the product design. Sex. Accordingly, if the adhesive force of only one side of the double-sided adhesive tape changes, resulting in unequal adhesion on both sides, the performance of the product may pose a problem, and there may be a case where the reworkability is lowered.

The influence of the interaction between the adhesive component and the composition of the printed layer not only affects the above adhesion, but also affects the physical properties necessary for the adhesive tape such as the retention force and the adhesion index. Moreover, since the environment such as temperature, humidity, and storage time according to the position of the adhesive tape differs depending on the influence of the interaction, the verification experiment is complicated. Therefore, the inventors of the present invention considered that it would be difficult to solve the problem in the case where the adhesive layer was in contact with the printed layer.

However, from the viewpoint of stability against thermal deterioration or deterioration over time, there is a case where a polyoxygen-based adhesive having higher durability than a general acrylic adhesive is expected. In the case of using a polyoxygen-based adhesive, it is necessary to apply a primer to the substrate in order to improve the adhesion to the substrate. However, if a solution in which the primer component is dissolved is applied onto the printed layer, the printed layer may swell due to the influence of the organic solvent contained in the primer solution, causing the printed layer to peel off from the substrate to cause pinholes.

Patent Document 6 describes that the conductive component (carbon black or the like) contained in the light-shielding layer (black printed layer) of the adhesive tape is prevented from being turned on, and the type of the substrate, the type of the adhesive layer, the type of the light shielding layer, and the reflective layer are described. Type, order of the layers, etc. Make various combinations. However, in the various layer configurations of the adhesive tape, for example, when the white printed layer is in direct contact with the black printed layer, a white printed layer is formed on one substrate, and black is formed on the upper surface by a plurality of times of printing. The layer printed layer (refer to the embodiment) may cause the smoothness of the surface of the printed layer to be lost as the number of times of printing increases, and as a result, there may be a change in the adhesive property or a sag (a gap between the layers) when wound up on the roll. Sex.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-156015

Patent Document 2: Japanese Patent Laid-Open Publication No. 2009-197124

Patent Document 3: Japanese Patent Laid-Open Publication No. 2011-95764

Patent Document 4: International Publication No. 2009/020043

Patent Document 5: Japanese Patent Laid-Open Publication No. 2010-53240

Patent Document 6: Japanese Patent Laid-Open No. 2011-214010

An object of the present invention is to provide an adhesive tape having both light-reflecting properties and light-shielding properties, which is less likely to cause adhesion of a laminated substrate, pinholes due to peeling of a printed layer, and easy adjustment of physical properties such as adhesion, and excellent reworkability. It can be easily applied to an adhesive tape such as a polyoxygen adhesive layer.

As a result of intensive studies to achieve the above object, the inventors of the present invention have found that the use of a laminated substrate having a specific layer structure is very effective, and the present invention has been completed.

That is, the adhesive tape of the present invention includes: a laminated base material; and an adhesive layer provided on at least one surface of the laminated base material; wherein the laminated base material is formed by laminating at least one black printed layer on the support body The laminate and the laminate having at least one layer of a bright printed layer laminated on the support are bonded to each other on one side of the printed layer via an adhesive layer.

Since the printed layer of the adhesive tape of the present invention is present on the inner side of the support, it is less likely to cause sticking or pinholes due to peeling of the printed layer, and as a result, light blocking properties or deterioration of light reflectance can be prevented. Further, since the printed layer and the adhesive layer are not in contact with each other, component migration does not occur between the adhesive layer and the printed layer, physical properties such as adhesion can be easily adjusted, and the workability is excellent, and can be easily applied to, for example, a substrate. A layer of a polyoxygenated adhesive layer treated with a primer on the surface.

1a, 1b‧‧‧Support

2‧‧‧Black printed layer

3‧‧‧ Bright print layer

4‧‧‧ adhesive layer

5a, 5b‧‧‧Adhesive layer

6‧‧‧ Primer treatment layer

7‧‧‧Polycarbonate board

8‧‧‧Test piece (adhesive tape)

9‧‧‧ Hammer

10‧‧‧Test piece (adhesive tape)

11‧‧‧Adhesive film

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view showing an embodiment of an adhesive tape (double-sided) of the present invention.

Fig. 2 is a schematic cross-sectional view showing an embodiment of an adhesive tape (single side) of the present invention.

Fig. 3 is a schematic cross-sectional view showing the constant weight peeling test of the examples and the comparative examples.

4(a) and 4(b) are schematic plan views showing the method of evaluating the adhesion of the substrate of the examples and the comparative examples.

Fig. 1 is a schematic cross-sectional view showing an embodiment in which the adhesive tape of the present invention belongs to a double-sided adhesive tape. In this embodiment, the laminated base material is a laminated body in which the black printed layer 2 is laminated on the support 1a, and a laminated body in which the bright printed layer 3 is laminated on the support 1b so as to be adjacent to the printed layer 2 and 3 sides. One side, separated by an adhesive layer 4 Made by joining. Then, adhesive layers 5a and 5b are provided on both sides of the laminated substrate. In the laminated structure, since the black printed layer 2 (light shielding layer) and the bright printed layer 3 (light reflective layer) are not in direct contact with the adhesive layers 5a and 5b, respectively, the adhesive layer 5 and the printed layers 2 and 3 are The interaction between the composition of the adhesive layer and the composition of the printed layer can be solved without the component migration. As a result, the adjustment of the adhesive composition for obtaining the desired adhesive force tends to be easy, and the yellowing of the adhesive layer is less likely to occur. Further, it is easy to adjust the thickness of the printed layer of the black printed layer 2 (light-shielding layer) and the bright printed layer 3 (light-reflecting layer) and the amount of the ink component added.

Furthermore, since the laminated substrate of the present invention has the above specific layer structure, when the laminated substrate is wound up in a roll shape immediately after the production of the laminated substrate (before the formation of the adhesive layer 5), the printed layers are not yet in contact with each other. Will come into contact, it is not easy to cause adhesion, and pinholes are formed due to peeling of the printed layer. As a result, it is possible to prevent the light-shielding property or the reflectance from being lowered, and the workability is also excellent.

The adhesive tape shown in Fig. 1 is a preferred embodiment of the present invention, but the present invention is not limited thereto. For example, the adhesive tape shown in FIG. 1 is a double-sided adhesive tape provided with adhesive layers 5a and 5b on both sides of the laminated substrate, but as shown in FIG. 2, the adhesive layer 5a may be provided only on one surface. Single-sided adhesive tape. Further, in the adhesive tape shown in Fig. 2, a primer treatment 6 is provided between the adhesive layer 5a and the black printed layer 2. When an adhesive layer composed of a polyoxygen-based adhesive is formed on a substrate, a primer treatment must be applied to the surface of the substrate on which the polyoxygen-based adhesive is applied. However, it is generally difficult to apply a primer treatment on the printed layer. On the other hand, since the laminated substrate of the present invention has a structure in which the printed layers 2 and 3 are sandwiched by the supports 1a and 1b, the primer can be easily handled and can be easily applied to the polyoxygen-based adhesive layer.

Furthermore, for example, the adhesive tape shown in FIG. 1 is composed of a black printed layer 2 The light-shielding layer is formed, but a light-shielding layer may be formed of two or more black printed layers 2 as needed. Further, in the adhesive tape shown in Fig. 1, the light-reflecting layer is composed of one layer of the bright printed layer 3, but the light-reflecting layer may be composed of a laminated body of two or more bright-colored printed layers 3 as necessary.

Furthermore, the adhesive tape shown in FIG. 1 is attached to the support 1a or 1b, and the black printed layer 2 or the bright printed layer 3 is directly laminated, but may be between the support 1a and the black printed layer 2, or on the support. There are any other layers between 1b and the bright printed layer 3. Further, the adhesive tape shown in Fig. 1 is formed by directly laminating the adhesive layer 5a or 5b on the outer side surface of the support 1a or 1b, but any other layer may be present on each outer side surface and the adhesive layer 5a or 5b.

[Support 1a and 1b]

The support bodies 1a and 1b of the present invention are not particularly limited, and such an adhesive tape can be used for the user. For example, a resin film, a non-woven fabric, paper, cloth, or the like, and combinations thereof may be used. Among them, a resin film is preferred, and a transparent or translucent plastic film is preferred. Specific examples thereof include a polyester resin, a polypropylene resin, a polycarbonate resin, a polystyrene resin, a polyethylene resin, an acrylic resin, a polyacetal resin, an acetate resin, and a polyether oxime. A resin, a polyolefin resin, a fluorine resin, a polyvinyl chloride resin, a polyvinylidene chloride resin, a polyvinyl alcohol resin, a polyarylate resin, or a polyphenylene sulfide resin. In particular, from the viewpoints of economy, workability, ease of use, and the like, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate are preferred. From the viewpoints of market versatility (grade richness) and the like, polyethylene terephthalate is more preferred.

The thickness of the support bodies 1a and 1b is usually 2 to 100 μm, preferably 3 to 50 μm, more preferably 6 to 25 μm, and particularly preferably 6 to 12 μm.

[Black Print Layer 2]

The black printed layer 2 of the present invention is not particularly limited, and various known black printed layers capable of imparting necessary shading functions to the adhesive tape can be used. The black printed layer 2 is usually formed by a known printing method using an ink composition. The ink composition contains, for example, a coloring component (ink component), a binder resin, and a curing agent.

Specific examples of the coloring component (ink component) used in the black printing layer 2 include carbon black, acetylene black, graphite, iron oxide, copper oxide, aniline black, and activated carbon. Specific examples of the binder resin include a polyurethane resin, a phenol resin, an epoxy resin, an acrylic resin, a polyester resin, a polyolefin resin, a natural rubber, a styrene butadiene rubber, and a butyl group. Diene rubber, ethylene propylene rubber. Among them, a polyurethane resin is preferred. Specific examples of the curing agent include an isocyanate curing agent, an epoxy curing agent, a melamine curing agent, and an aziridine curing agent. The composition ratio of each component may be a known composition ratio, and may be appropriately determined as needed.

The ink composition used in the black printing layer 2 can be obtained, for example, by blending a curing agent in a commercially available printing ink containing a coloring component (ink component) and a binder resin.

The thickness of the black printed layer 2 is usually 0.5 to 10 μm, preferably 0.5 to 6 μm, more preferably 1 to 5 μm, and most preferably 2 to 4 μm. The black printed layer 2 may constitute a light shielding layer in a single layer, or may be formed of a plurality of black printed layers 2 to form a light shielding layer.

Specific examples of the printing method of the ink composition include a gravure printing method, an elastic printing method, a lithography method, a letterpress printing method, a screen printing method, a stencil printing method, and a letterpress printing method.

[Bright print layer 3]

The bright color printing layer 3 of the present invention is not particularly limited, and various known bright color printing layers capable of imparting a necessary light reflecting function to the adhesive tape can be used. The bright printed layer 3 can adjust the brightness (reflectance) of the light-reflecting layer relatively easily compared to the light-reflecting layer composed of the resin film containing the coloring agent described in Patent Document 1. Here, "bright color" means a color such as white or light color which can impart a light reflecting function. Very good white. Specifically, the L* (brightness) defined by the L*a*b* chromaticity system of the bright printed layer 3 is preferably 65 or more, and more preferably 75 or more. The bright printed layer 3 preferably has a reflectance at a wavelength of 550 nm of 45% or more, more preferably 65% or more. Further, the average reflectance at a wavelength of 380 to 780 nm is preferably 40% or more, more preferably 60% or more.

The bright printed layer 3 is usually formed using an ink composition by a known printing method. The ink composition contains, for example, a coloring component (ink component), a binder resin, and a curing agent.

Specific examples of the coloring component (ink component) used in the bright printed layer 3 include titanium oxide and zinc oxide. Specific examples of the binder resin and the curing agent are, for example, the same as those of the specific example of the black printed layer 2. The composition ratio of each component can be a known composition ratio, and can be appropriately determined as needed.

The ink composition used in the bright printed layer 3 can be obtained, for example, by blending a curing agent in a commercially available printing ink containing a coloring component (ink component) and a binder resin.

The thickness of the bright printed layer 3 is usually 0.5 to 10 μm, preferably 0.5 to 6 μm, more preferably 1 to 5 μm, and particularly preferably 2 to 4 μm. The bright printed layer 3 may constitute a light reflecting layer in a single layer, or may be formed by laminating a plurality of bright printed layers 3 to form a light reflecting layer.

[Binder layer 4]

In the present invention, a laminated body in which a black printed layer 2 is laminated on a support 1a and a laminated body in which a bright printed layer 3 is laminated on a support 1b are formed, and a surface on one side of the printed layers 2 and 3 is interposed between the adhesive layer 4 Engage. Therefore, in the case where the black layer printed layer 2 is formed by sequential printing on the white printed layer 3, for example, the smoothness of the surface of the printed layer can be improved, and as a result, there is no change in the adhesive property or the roll is taken up on the roll. The possibility of sagging (gap between layers) occurs.

The adhesive used in the adhesive layer 4 of the present invention is not particularly limited, and various known adhesives can be used as long as the function of the adhesive tape is not inhibited. Specific examples include a polyurethane-based adhesive, a polyester-based adhesive, an acrylic adhesive, and an epoxy-based adhesive. In particular, from the viewpoint of adhesion to the printed layers 2 and 3, it is preferable to use the same type of adhesive as the binder resin of the printed layer. That is, when the binder resin of the printing layers 2 and 3 is a polyurethane resin, it is preferably an amine ester-based adhesive, and in the case of a binder resin-based polyester resin, it is preferably a polyester-based adhesive. . However, an adhesive of a different form from the binder resin may be used under the premise that sufficient adhesion can be obtained.

The agent layer 4 can also be colored as needed. In particular, it is preferable to add a coloring component (ink component) used in the bright color printing layer 3 belonging to the light-reflecting layer to the same color to be colored. Thereby, the light reflectivity which is difficult to adjust compared with the light-shielding property can be easily adjusted.

A coating method of the subsequent agent can be carried out by a known coating method. Specific examples include a direct gravure method, a roll bonding method, a chamber doctor method, and a lithographic/gravure method. Among them, from the depth of use (the depth of the recess of the plate) The viewpoint of easily controlling the coating thickness by selection is preferably a direct gravure coating method.

The thickness of the subsequent agent layer 4 is usually 0.5 to 10 μm, preferably 0.5 to 6 μm, more preferably 1 to 5 μm, and particularly preferably 2 to 4 μm.

[Adhesive layer 5a and 5b]

The adhesive used in the adhesive layers 5a and 5b of the present invention is not particularly limited, and various known adhesives which can be used for such an adhesive tape can be used. Specific examples thereof include transparent adhesives such as an acrylic adhesive, a rubber adhesive, an amine ester adhesive, a polyester adhesive, and a polyoxygen adhesive. Among them, an acrylic adhesive, an amine ester adhesive, and a polyoxynoxy adhesive which are highly transparent are preferable.

Specific examples of the acrylic pressure-sensitive adhesive used in the pressure-sensitive adhesive layers 5a and 5b include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, and isopropyl (meth)acrylate. N-butyl methacrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, etc. (methyl An acrylate monomer as a main component, by reacting it with a functional group-containing monomer such as (meth)acrylic acid, crotonic acid, fumaric acid, itaconic acid, (anhydrous) maleic acid, Or an acrylic adhesive obtained by copolymerizing a monomer such as vinyl acetate, acrylonitrile, styrene, 2-hydroxyethyl (meth)acrylate or 2-hydroxymethylethylpropenylamine, if necessary.

Specific examples of the amine ester-based pressure-sensitive adhesive used in the pressure-sensitive adhesive layers 5a and 5b are, for example, an adhesive obtained by curing a polyol and a polyfunctional isocyanate compound to obtain a polyurethane resin as a main component. Specific examples of the polyhydric alcohol include polyester polyol, polyether polyol, polycaprolactone polyol, and polycarbonate polyol. As the polyfunctional isocyanate compound, a known polyfunctional aliphatic isocyanate compound or a polyfunctional aromatic isocyanate compound which can be used for the amine esterification reaction can be used.

The polyoxygenated adhesive used in the adhesive layers 5a and 5b is generally an adhesive based on a mixture of a polyoxyxene rubber and a polyoxyxene resin. Specific examples of the polyoxyxene rubber include, for example, an organic polyoxyalkylene which is composed of dimethyl siloxane as a constituent unit. A functional group (for example, a vinyl group) may also be introduced into the organopolyoxane as needed. A specific example of the polyoxyxylene resin may be, for example, a polyfluorene resin which is composed of a polyfunctional organosiloxane and a monofunctional organopolyoxane.

In particular, in the case of a polyoxygen-based adhesive, an adhesive resin or a crosslinking agent (hardener) may be added to the adhesive layers 5a and 5b as needed. Specific examples of the tackifying resin include rosin-based, polydecene-based, petroleum-based, terpene-based, and polystyrene-based resins. Specific examples of the curing agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent. In addition, if necessary, for example, a vulcanizing agent, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an antistatic agent, an ultraviolet absorber, a light stabilizer, a peeling adjuster, a softener, and an interface activity may be added. Additives such as agents, flame retardants, and antioxidants.

The adhesive layers 5a and 5b can also be colored as needed. For example, the adhesive layer 5a on the side of the black printed layer 2 can be colored black, and the adhesive layer 5b on the side of the bright printed layer 3 can be colored bright.

A coating method of the adhesive can be carried out by a known method. Specific examples include, for example, direct gravure method, roll bonding method, precision doctor blade method, lithographic/gravure method, roll coating method, reverse light touch method, top feed reverse mode, bottom feed reverse mode, mold coating Cloth method, lip coating method, hot melt coating method, knife coating method, Rolling method. Among them, from the viewpoint of easy control of the layer thickness, a roll coating method, a die coating method, a lip coating method, and a hot melt coating method are preferred.

The thickness of the adhesive layers 5a and 5b is usually 1 to 200 μm, preferably 3 to 80 μm, more preferably 5 to 50 μm, and particularly preferably 10 to 30 μm.

[Laminated substrate]

The laminated substrate of the present invention is a laminated body in which at least one black printed layer 2 is laminated on the support 1 described above, and a laminated body in which at least one bright printed layer 3 is laminated on the other support 1 to make each other A substrate on which one side of the printed layer 2 and the three sides are joined together via the adhesive layer 4. The thickness of the laminated substrate is appropriately determined in accordance with the required thickness of the adhesive tape. The thickness of the laminated substrate is preferably 5.5 to 230 μm, more preferably 18 to 36 μm.

The surface of the laminated substrate may also be subjected to a primer treatment as needed. Particularly, in the case where at least one of the adhesive layers contains a polyoxygen-based adhesive, in order to improve the adhesion between the laminated substrate and the adhesive layer, the surface of the laminated substrate is preferably subjected to a primer treatment. The type of the primer is not particularly limited, and for example, a commercially available polyoxynene primer can be used.

[adhesive tape]

The adhesive tape of the present invention is provided with the laminated base material described above and an adhesive tape provided with an adhesive layer 5 on at least one of the laminated base materials. The adhesive tape of the present invention may be provided with a layer or member other than the laminated substrate and the adhesive layer, within the range not impairing the effects of the present invention. For example: release liner such as release paper or release film; back treatment layer when single-sided tape is attached; antistatic layer capable of obtaining antistatic property; functional layer for improving any shielding function, heat release property, etc. Wait.

[Examples]

Hereinafter, the present invention will be further described by way of examples, but the invention is not limited thereto. In the following description, "parts" means "parts by mass".

<Example 1>

(Preparation of black ink composition)

100 parts of a commercially available black ink (manufactured by Toyo Ink Co., Ltd., trade name E039PETAK94 ink) containing a coloring component and a binder resin, and an isocyanate-based curing agent (manufactured by Toyo Ink Co., Ltd., trade name TK HARDENERXB) 8.0 The fraction was diluted with 9 parts of a mixed solvent of toluene and MEK (methyl ethyl ketone) (mass ratio = 1:1) to obtain a black ink composition.

(Preparation of bright ink composition)

100 parts of a commercially available white ink (manufactured by Toyo Ink Co., Ltd., trade name E039PET63 white) containing a coloring component and a binder resin, and an isocyanate-based curing agent (manufactured by Toyo Ink Co., Ltd., trade name TK HARDENERXB) 6.0 The fraction was diluted with 26 parts of a mixed solvent of toluene and MEK (mass ratio = 1:1) to obtain a bright ink composition.

(Preparation of the composition of the adhesive)

A commercially available white ink containing a coloring component and a binder resin (made by Toyo Ink Co., Ltd., a product) is blended with 100 parts of a commercially available polyester-based adhesive (manufactured by Toyo-Morton Co., Ltd., trade name: AD-76P1). 40 parts of E039PET63 white and isocyanate-based hardener (manufactured by Toyo-Morton Co., Ltd., trade name CAT-RT85) 12.0 The fraction was diluted with 110 parts of toluene to obtain a binder composition A which was colored in white.

(Preparation of adhesive composition)

0.9 parts of an isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name hardener AL) was blended with 100 parts of an acrylic adhesive material (SAIVINOL (registered trademark) SN-007, manufactured by Saiden Chemical Co., Ltd.). The composition of the adhesive was obtained by diluting with 90 parts of ethyl acetate.

(Production of laminated substrate A)

On the one side of the 6 μm thick transparent PET film used as the support 1a, gravure printing (gravure roll: 75 lines/depth 140 μm) was carried out using the previously prepared black ink composition, and cooked at 40 ° C for 2 days. A black printed layer 2 having a thickness of 5 μm was formed. On the other hand, on one side of the transparent PET film having a thickness of 6 μm as the support 1b, gravure printing was carried out using the bright ink composition prepared therefrom (gravure roll: 110 lines/depth 90 μm), after 40 After solidification at ° C for 2 days, a bright printed layer 3 having a thickness of 3 μm was formed [L* (brightness) = 65, and an average reflectance for a wavelength of 380 to 780 nm = 61%]. Next, on the bright-color printing layer 3, the previously prepared adhesive composition was applied by a gravure coater (gravure roll: 110 lines/depth 95 μm) to form an adhesive layer 4 having a thickness of 3 μm. Then, the adhesive layer 4 was bonded to the black printed layer 2 of the support 1a, and after 40° C. and 3 days of aging, the support 1a/black printed layer 2/adhesive layer 4/bright printed layer was obtained. 3/ The support substrate 1b has a laminated base material A having a total thickness of 23 μm.

(production of double-sided adhesive tape)

The previously prepared adhesive composition was applied by a roll coating method on a release-treated surface of a release film (manufactured by Nakamoto Packs Co., Ltd., trade name: MA25) which was subjected to polyfluorination treatment on one surface of the resin film. The thickness of the adhesive layers 5a and 5b after drying was 18.5 μm, and the solvent (ethyl acetate) was removed by drying in a drying oven. The adhesive composition layer on the release film was bonded to both sides of the laminated substrate A previously prepared, and after 40 ° C for 3 days, the adhesive layer 5a/ shown in Fig. 1 was obtained. A double-sided adhesive tape formed by the constitution of the support 1a/black print layer 2/adhesive layer 4/bright print layer 3/support 1b/adhesive layer 5b.

<Comparative Example 1>

(Production of laminated substrate B)

On the one side of the 12 μm thick transparent PET film used as the support 1b, gravure printing was carried out using the bright ink composition prepared in Example 1 (gravure roll: 110 lines / plate depth 90 μm), at 40 ° C, 2 The aging of the day formed a bright printed layer 3 having a thickness of 6 μm. Next, on the bright-color printing layer 3, gravure printing (gravure roll: 75 lines/plate depth: 140 μm) was carried out using the black ink composition adjusted in Example 1, and after 40 ° C, 2 days of aging, a thickness of 5 μm was formed. The black printed layer 2 is obtained as a laminated base material B formed of the color printed layer 2/bright printed layer 3/support 1b.

(production of double-sided adhesive tape)

Adhesive layers 5a and 5b were formed on both sides of the laminated substrate B in the same manner as in Example 1 to obtain an adhesive layer 5a/black printed layer 2/bright printed layer 3/support 1b/adhesive layer. A double-sided adhesive tape formed by the composition of 5b.

<Comparative Example 2>

(production of double-sided adhesive tape)

The adhesive layer 5a/ was obtained in the same manner as in Comparative Example 1, except that the thickness of the dried adhesive layer 5a was changed to 15 μm, and the thickness of the dried adhesive layer 5b was changed to 22 μm. A double-sided adhesive tape formed by the formation of the black printed layer 2/bright print layer 3/support 1b/adhesive layer 5b.

The double-sided adhesive tape obtained in the above Example 1 and Comparative Examples 1 and 2 was evaluated in accordance with the following method. The results are shown in Table 1.

(adhesion to SUS)

The adhesion to the SUS plate was measured in accordance with JIS Z 0237 (2000).

(penetration concentration)

The penetration density of the double-sided adhesive tape was measured using a portable black-and-white transmission densitometer (manufactured by Ihara Electronics Co., Ltd., trade name: TM-5). Since the measurement range of the device is 0.0 to 6.0, the penetration concentration exceeding the range is marked as "6.0 or more".

(Reflectivity)

The average reflectance was measured in the wavelength range of 380 to 780 nm using an ultraviolet-visible infrared spectrophotometer (manufactured by JASCO Corporation, trade name: V-670).

(holding force, viscosity)

The holding power and the viscosity were measured in accordance with JIS Z 0237 (2000). However, the relevant holding force was measured in accordance with the conditions of the adhesive area of 20 × 20 mm, the load of 1 kg, the heating temperature of 70 ° C, and the heating time of 60 minutes.

(adhesion to PC)

The adhesion to the polycarbonate sheet was measured in accordance with JIS Z 0237 (2000).

<evaluation>

As is apparent from the results shown in Table 1, the adhesive tape of Example 1 was excellent in all physical properties, and the adhesion, retention, and viscosity on the black side and the bright side were almost equal. Moreover, the layer structure of the printing peeling or the formation of pinholes is not caused in the manufacturing step. Moreover, it is also possible to perform heavy processing with peace of mind.

On the other hand, the black printed layer 2 is in contact with the adhesive tape of Comparative Example 1 of the adhesive layer 5a, and the adhesive force, holding force and adhesiveness of the adhesive layers 5a and 5b on both sides are both present. Large offset. This phenomenon is considered to be caused by a part of the hardener added to the acrylic adhesive of the adhesive layer 5a being absorbed by the black printed layer 2, resulting in a decrease in the degree of hardening of the adhesive layer 5a. As a result, the adhesive tape of Comparative Example 1 may have residual glue on the black side (adhesive layer 5a side) (partial adhesive remains at the time of peeling) or may be defective in the initial stage, and may have poor reworkability.

In the adhesive tape of Comparative Example 2, the black printed layer 2 was in contact with the adhesive layer 5a in the same manner as in Comparative Example 1, but attempts were made to adjust the thickness of the two adhesive layers 5a and 5b so that the adhesive forces on both sides were equal. An example. As a result, the adhesion to SUS becomes equal. However, the adhesion (adhesiveness and adhesion) to the PC on the black side (adhesive layer 5a side) was too low, and the adhesion on the bright side (the side of the thick adhesive layer 5b) was too high. As a result, in the adhesive tape of Comparative Example 2, there was a possibility that the black side (adhesive layer 5a side) had an initial failure and peeling failure, and the bright side (the thick adhesive layer 5b side) was caused by sticking. Possibility of poor sex.

Next, with respect to the double-sided adhesive tape obtained in Example 1 and Comparative Example 2, the following constant load peeling test was carried out. The results are shown in Table 2.

(fixed load peel test)

As shown in FIG. 3, a test piece 8 (adhesive tape) having a width of 20 mm and a length of 50 mm was adhered to the polycarbonate plate 7, and a reciprocating pressure was applied by a 2 kg roller, and the skin was cured for 20 minutes under normal conditions, and then, at an angle of 90°. Use a 100g hammer 9 to hang. In this state, it was stored in a dryer at 70 ° C for 60 minutes, and the offset distance (mm) of the test piece 8 or the drop time of the hammer 9 at this time was measured. The measurement was carried out in each period, such as the initial stage, the third day, the seventh day, and the fourth day. The results are shown in Table 2.

[Table 2]

<evaluation>

From the results shown in Table 2, it was found that the adhesive tape of Example 1 caused less shift with time. Therefore, even in the case of secondary processing such as punching, the adhesive does not adhere to the guide roller together with the printed layer, and it is predicted that the trouble in the step does not occur even after long-term storage after daily storage. On the other hand, in the adhesive tape of Comparative Example 2, the black side (adhesive layer 5a side) appeared to have a large offset with time.

<Example 2>

(Preparation of adhesive composition)

With respect to 100 parts of a polyoxynoxy adhesive material (manufactured by Toray‧Dow Corning Co., Ltd., trade name: SD-4580), 0.9 parts of a catalyst (manufactured by Toray‧Dow Corning Co., Ltd., trade name NC25) was added, and added. Appropriate amount of toluene to obtain an adhesive composition.

(Preparation of primer composition)

100 parts of a poly-xylene-based primer raw material (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KR-3006A), 10 parts of a blending agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KR-3006BT) Catalyst (Shin-Etsu Chemical Industry Co., Ltd. 0.5 part of the product name, CAT-PS-8S), and an appropriate amount of toluene was added to obtain a primer composition.

(Production of laminated substrate A')

On the surface of the support 1a of the laminated substrate A produced in Example 1, the previously prepared primer composition was applied by a roll kiss film to form a primer treatment layer 6 to obtain a laminate base. Material A'.

(production of single-sided adhesive tape)

On the primer treatment layer 6 of the laminated substrate A', the thickness of the adhesive layer 5a after drying is 30 μm, and the previously prepared adhesive composition is applied by a roll coating method, and then the solvent is dried by a dryer (toluene). , a single side formed by the composition of the adhesive layer 5a/primer treatment layer 6/support 1a/black print layer 2/adhesive layer 4/bright print layer 3/support 1b as shown in FIG. 2 is obtained. Adhesive tape.

<Reference Example 1>

(production of single-sided adhesive tape)

The composition of the adhesive layer 5a/support 1a/black print layer 2/adhesive layer 4/bright print layer 3/support 1b was obtained in the same manner as in Example 2 except that the primer treatment layer 6 was not formed. The formed single-sided adhesive tape.

<Comparative Example 3>

(Production of laminated substrate B')

The black printed layer 2/bright printed layer 3/ was obtained in the same manner as the laminated base material B of Comparative Example 1 except that the support 1b was a transparent PET film having a thickness of 6 μm. The laminated substrate B' formed by the structure of the support 1b.

(production of single-sided adhesive tape)

A single sheet formed of the adhesive layer 5a/primer treatment layer 6/black print layer 2/bright print layer 3/support 1b was obtained in the same manner as in Example 2 except that the build-up substrate B' was used. Adhesive tape.

<Comparative Example 4>

(production of single-sided adhesive tape)

A single-sided adhesive tape formed of the adhesive layer 5a/black printed layer 2/bright printed layer 3/support 1b was obtained in the same manner as in Comparative Example 3 except that the primer treatment layer 6 was not formed.

The adhesive tapes obtained in the above Example 2, Reference Example 1, and Comparative Examples 3 and 4 were evaluated in accordance with the following methods. The results are shown in Table 3.

(normal state and adhesion to SUS after heating)

The adhesion to the SUS plate was measured in accordance with JIS Z 0237 (2000). However, the adhesion after heating was heat-treated at 120 ° C for 2 hours in a heating furnace, and after standing at room temperature for 2 hours, the adhesion was measured in accordance with the conditions specified in JIS Z 0237 (2000).

(Residue)

The adhesion to SUS after heating was confirmed by the presence or absence of residual glue when the adhesive tape was peeled off (a part of the adhesive layer adhered to the side of the adherend).

(substrate adhesion)

First, as shown in Fig. 4 (a), at the center of the test piece 10 (adhesive tape) having a size of 25 × 50 mm, a 2 mm cut mark was drawn by a cutter. Next, as shown in Fig. 4 (b), the test piece 10 was partially cleaved from the cut mark to 20 mm, and the length of the adhesive film 11 was measured without being broken, and evaluation was performed in accordance with the following criteria.

"○": The length of the adhesive film 11 is 2 mm or less.

"X": The length of the adhesive film 11 exceeds 2 mm.

(Retentivity)

According to JIS Z 0237 (2000), it was measured under the conditions of a bonding area of 10 × 20 mm, a load of 200 g, a heating temperature of 150 ° C, and a heating time of 30 minutes.

<evaluation>

As is apparent from the results shown in Table 3, the adhesive tape-based substrate of Example 2 was excellent in all physical properties such as adhesion. This phenomenon is considered to be that the black printed layer 2 having poor compatibility with the polyoxygen-based adhesive is used as the laminated substrate A formed inside the support 1a, and the primer treatment layer is provided on the surface of the support 1a. Caused by 6 reasons. On the other hand, Reference Example 1 in which the primer treatment layer 6 was not provided, Comparative Example 3 in which the primer treatment layer 6 was directly in contact with the black printed layer 2, and the black printed layer 2 were in direct contact with the polyoxynitride-based adhesive layer 5a. In Comparative Example 4, the adhesion between the substrate and the holding property was poor, and residual glue was also generated. In addition, since the reference example 1 has the same layer configuration as that of the first embodiment, for example, the effect of the composition of the layer between the pressure-sensitive adhesive layer and the printing layer is excellent, and the effect is excellent.

<Reference Example 2~6>

(Preparation of the composition of the adhesive)

1 part of an isocyanate-based hardener (manufactured by Toyo-Morton Co., Ltd., trade name CAT-RT85) was blended with 100 parts of a commercially available polyester-based adhesive (manufactured by Toyo-Morton Co., Ltd., trade name: AD-76P1). It was diluted with 110 parts of toluene to obtain an adhesive composition (Reference Example 2). In addition, 10 parts (Reference Example 3), 30 parts (Reference Example 4), and 50 parts (reference example) of white ink (manufactured by Toyo Ink Co., Ltd., trade name E039PET63 white) were added to 222 parts of the adhesive composition. 5) The amount of 100 parts (Reference Example 6) was further added with an appropriate amount of toluene to obtain each of the adhesive compositions having different white ink addition amounts.

(Production of laminated substrate)

In the same manner as in Example 1, except that each of the adhesive compositions having different amounts of white ink added as described above was used, the support 1a/black printed layer 2/joined was obtained. A laminate substrate formed by the composition of the primer layer 4/bright print layer 3/support 1b and having a total thickness of 23 μm.

With respect to the adhesive tapes obtained in the above Reference Examples 2 to 6, the average reflectance was measured in accordance with the above measurement method. The results are shown in Table 4.

<evaluation>

As is apparent from the results shown in Table 4, the adhesive tape of the present invention can easily control the light reflectivity by coloring the adhesive layer to a bright color.

(industrial availability)

The adhesive tape of the present invention has an adhesive tape having both light-reflecting properties and light-shielding properties, and is less likely to cause adhesion of the laminated base material or pinhole formation due to peeling of the printed layer, and the physical properties such as adhesion are easily adjusted, and the workability is excellent. For example, a polyoxygen-based adhesive layer can be easily applied, and thus it is suitable for use in, for example, a liquid crystal display panel of a liquid crystal display device used in a mobile phone, a touch panel, a computer, a car navigation, a game machine, a television, etc., and Fixed between backlight units.

1a‧‧‧Support

1b‧‧‧Support

2‧‧‧Black printed layer

3‧‧‧ Bright print layer

4‧‧‧ adhesive layer

5a‧‧‧Adhesive layer

5b‧‧‧Adhesive layer

Claims (6)

An adhesive tape comprising: a laminated substrate; an adhesive layer provided on at least one surface of the laminated substrate; wherein the laminated substrate is a laminate in which at least one black printed layer is laminated on the support And a laminate having at least one layer of a bright printed layer laminated on the support, and being joined to each other on one side of the printed layer via an adhesive layer. The adhesive tape of claim 1, wherein the resin film is supported. The adhesive tape of claim 1, wherein at least one of the adhesive layers contains a polyoxygenated adhesive. The adhesive tape of claim 3, wherein the surface of the laminated substrate provided with the adhesive layer containing the polyoxygen-based adhesive is subjected to a primer treatment. The adhesive tape of claim 1, wherein the adhesive layer is colored to a bright color. The adhesive tape of claim 1, wherein the adhesive tape is used for fixing between the liquid crystal display panel and the backlight unit.