JP2017071730A - Adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive sheet excellent in weather resistance and durability which has good adhesiveness to an adherend, produces no paste (adhesive) residue on the adherend in the case of peeling off and has excellent peelability so that the adhesive itself is not damaged.SOLUTION: There is provided an adhesive sheet having a layer structure of a member layer (B)/an adhesive layer (C), wherein the adhesive layer (C) is configured to have a layer structure of an adhesive layer (c2)/a core material (c1)/the adhesive layer (c2).SELECTED DRAWING: Figure 1

Description

  The present invention has good adhesion to the adherend, and when peeled from the adherend, there is no adhesive (adhesive) residue on the adherend, and the adhesive sheet itself is not damaged. The present invention relates to an adhesive sheet excellent in adhesiveness and peelability.

  Conventionally, as an adhesive sheet, what is shown in FIG. 7, for example is used. In FIG. 7, A is a support film, B is a member layer made of a resin composition in which members imparting functions such as color and shielding are blended, C is an adhesive layer, and D is a release liner. In order to affix the pressure-sensitive adhesive sheet to the adherend, first, the release liner D is removed, the pressure-sensitive adhesive layer C made of a pressure-sensitive adhesive is exposed, the pressure-sensitive adhesive layer C is adhered to the adherend, and the pressure-sensitive adhesive layer C is adhered. This is done by using force.

  However, when the adhesive sheet is pasted on the adherend, if there is a deficiency such as the adhesive sheet being displaced from the intended position, the adhesive sheet is once peeled off from the adherend and then pasted again. . At this time, when the adhesiveness of the adhesive sheet to the adherend is high, the adhesive sheet adhesive (adhesive layer C in this example) remains on the trace of the adhesive sheet being peeled off, or the adhesive sheet is forcibly removed. As a result, the adhesive sheet itself may be damaged. On the other hand, if importance is attached to the peelability of the pressure-sensitive adhesive sheet, there arises a problem that the adhesiveness with the adherend is insufficient and the adhesive sheet falls off after long-term use.

  In order to solve such a problem, for example, in Patent Document 1, the material of the base material (member layer B) and the pressure-sensitive adhesive layer (adhesive layer C) is specified, for example, while ensuring the adhesiveness, A pressure-sensitive adhesive sheet that has been devised so that there is no adhesive residue on the adherend during peeling has been proposed.

JP-A-9-208907

  However, in the technique disclosed in Patent Document 1, the material of the pressure-sensitive adhesive layer (pressure-sensitive adhesive layer C) is limited to a rubber system, and further, the base material (member layer B) is required to contain rubber. For this reason, there exists a problem that an adhesive sheet is inferior to a weather resistance and durability. Further, the peelability is still not satisfactory, and further, no consideration is given to the curved surface adhesiveness. The present invention has been made in view of such circumstances, and provides a pressure-sensitive adhesive sheet having good adhesiveness to an adherend and excellent peelability, and excellent weather resistance, durability, and curved-surface adhesiveness. It is intended to do.

  However, the inventors of the present invention have made further studies by paying attention to the structure of the pressure-sensitive adhesive layer, not the pressure-sensitive adhesive layer and the material of the base material, in the process of earnestly researching to solve the above problems. As a result, the pressure-sensitive adhesive layer has a layer structure in which the pressure-sensitive adhesive layer, the core material, and the pressure-sensitive adhesive layer are laminated in this order, thereby improving the pressure-sensitive adhesiveness, peelability, durability, weather resistance, and curved surface pressure-sensitive adhesiveness. The present invention has been completed.

<Summary of the invention>
That is, this invention is an adhesive sheet which has a layer structure of a member layer (B) / adhesion layer (C), and the said adhesive layer (C) is an adhesive layer (c2) / core material (c1) / adhesive. A pressure-sensitive adhesive sheet having the layer structure of the layer (c2) is a first gist.

  Moreover, this invention is an adhesive sheet which has a layer structure of a support film (A) / member layer (B) / adhesion layer (C), and the said adhesive layer (C) is an adhesive layer (c2) / core material. A pressure-sensitive adhesive sheet having a layer structure of (c1) / pressure-sensitive adhesive layer (c2) is a second gist.

  The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer (c2) / core material (c1) in which the pressure-sensitive adhesive layer has a core material made of paper, non-woven fabric, film, metal foil, or the like, not simply made of a pressure-sensitive adhesive composition. / It has a layer structure of an adhesive layer (c2). For this reason, even if the adherend has a curved surface, excellent adhesiveness can be exhibited. Although the reason for this is not clear, normally, the adhesive layer and the adherend are bonded to each other by a force to peel off the support film and the curved surface portion of the member layer, and the pressure-sensitive adhesive layer is deformed. Due to this deformation, the force applied to the pressure-sensitive adhesive layer is concentrated on the end portion, and peeling occurs from the attached end portion. On the other hand, when the core material layer (c1) is provided, force is transmitted through the hard core material, so that a force to peel relatively uniformly acts on the adhesive layer (c2) in contact with the adherend. . For this reason, it is thought that a deformation | transformation of an adhesive layer (c2) decreases, and peeling of an adhesive sheet will become difficult to occur.

  Further, when the attached adhesive sheet is peeled off from the adherend, the adhesive (adhesive layer (c2)) does not remain on the adherend and the adhesive sheet itself is not damaged. The reason for this is not clear, but usually, an intermolecular force acts between the pressure-sensitive adhesive and the adherend due to the force of pulling from the member layer (B) side during the peeling process. Due to the intermolecular force at the interface, the pressure-sensitive adhesive layer is deformed, or a force is applied only to a part of the pressure-sensitive adhesive sheet, and the weakest part is broken. Therefore, glue remains on the adherend or the adhesive sheet itself is damaged. On the other hand, when the core material (c1) is provided, the force is transmitted to the pressure-sensitive adhesive layer (c2) through the hard core material, and the pressure-sensitive adhesive layer (c2) in contact with the adherend is the core material ( It follows c1) and is pulled relatively evenly. For this reason, since there is little deformation | transformation of an adhesive layer (c2) or force is applied to an adhesive sheet uniformly, it is thought that adhesive residue and an adhesive sheet are hard to occur.

  Therefore, even when the adhesive sheet is applied to a position different from the desired application position on the adherend surface, the adhesive sheet can be peeled off in a beautiful state and can be applied again to the desired application position. . Further, it can be suitably used as a management label between processes for producing a product and a distribution label at the time of distribution, which are peeled off when they are no longer needed.

It is sectional drawing which shows typically the adhesive sheet which is one embodiment of this invention. It is sectional drawing which shows typically the adhesive sheet which is the other form of this invention. It is a figure explaining the manufacturing method of the adhesive sheet shown in FIG. It is a figure explaining the manufacturing method of the adhesive sheet shown in FIG. (I), (II) is a figure explaining the manufacturing method of the adhesive sheet shown in FIG. It is a figure explaining the manufacturing method of the adhesive sheet shown in FIG. It is sectional drawing which shows the conventional adhesive sheet typically.

  Next, the form for implementing this invention is demonstrated in detail.

  FIG. 1 is a cross-sectional view schematically showing an adhesive sheet according to an embodiment of the present invention. In this pressure-sensitive adhesive sheet, a support film (A), a member layer (B), a pressure-sensitive adhesive layer (C), and a release liner (D) are laminated in this order, and the pressure-sensitive adhesive layer (C) is a pressure-sensitive adhesive layer (c2). ), A core material (c1), and an adhesive layer (c2). And in order to affix this adhesive sheet to a to-be-adhered body, a peeling liner (D) is removed, the adhesive layer (c2) which has adhesive force is exposed, and this adhesive layer (c2) is attached to an adherend. Adhere closely. Accordingly, when the pressure-sensitive adhesive sheet is attached to the adherend, the support film (A) becomes the outermost surface. The pressure-sensitive adhesive sheet will be described in detail below. In addition, in FIG. 1, each part is shown typically and is different from the actual thickness, size, etc. (the same applies to the following figures).

<Support film A>
A support film (A) becomes an outermost surface of an adhesive sheet, when an adhesive sheet is affixed on a to-be-adhered body. Therefore, as the support film (A), a film having excellent durability and scratch resistance is generally used. Further, as the support film (A), a commercially available product film may be used as it is, or a film obtained by applying a resin material and drying it may be used.

  Commercially available product films include cellophane, celluloid, synthetic paper, art paper, retroreflective sheet, polyethylene cloth, kraft paper, biaxially oriented polypropylene (OPP) film, polyethylene terephthalate (PET) film, nonaxially oriented polypropylene ( A CPP) film or a thermoplastic resin film can be used.

  Moreover, when using the thing which apply | coated resin material and dried and used it as a film form, as a resin material, according to the use of an adhesive sheet, a conventionally well-known material can be selected suitably and can be used, The member demonstrated later The same resin as the layer (B) may be used, or another resin may be used. Furthermore, the support film (A) may be a single layer or a multilayer.

  The thickness of the support film (A) is preferably in the range of 3 to 200 μm, more preferably 5 to 100 μm, still more preferably 8 to 50 μm, and particularly preferably 10 to 30 μm. Even in the case of multiple layers, the total thickness of the multiple layers is preferably within this range. If the thickness is too thin, the strength of the pressure-sensitive adhesive sheet obtained tends to decrease, and if it is too thick, the flexibility tends to decrease.

  Moreover, in order to raise the adhesive force with the member layer (B) arrange | positioned on the surface of a support film (A), physical processing, such as a sandblasting process, a flame process, a corona process, or a plasma process etc. It is preferable to perform physicochemical treatment or primer treatment. However, an excessive adhesive force is not required. For example, even if the interlayer adhesive strength is 10 N / 25 mm or less, the obtained pressure-sensitive adhesive sheet can exhibit excellent effects.

<Member layer B>
The member layer (B) secures the function of the pressure-sensitive adhesive sheet, and includes a material having a function (for example, color, retroreflection, decoration, transmission of light, electromagnetic waves, sound, water, and shielding) and a resin. It consists of a mixed composition. Examples of the resin used for the member layer (B) include polyolefin resins such as polyethylene and polypropylene, ethylene-vinyl acetate copolymer resin (EVA), ethylene-ethyl acrylate copolymer resin (EEA), and ethylene-methyl methacrylate copolymer resin. (EMMA), ionomer resin, ethylene-glycidyl methacrylate copolymer resin (EGMA), ethylene-maleic anhydride polymer resin (unsaturated carboxylic acid modified polyolefin), amorphous polyolefin (APO) and other olefin copolymer resins, natural rubber , Isoprene rubber, styrene butadiene rubber, styrene butadiene hydrogenated product, styrene butadiene block copolymer resin, styrene butadiene block copolymer resin hydrogenated product, styrene isoprene block copolymer resin, butyl rubber, Rubber resins such as isobutylene, silicone rubber, polyvinyl isobutyl ether, chloroprene rubber, nitrile rubber, chlorine resins such as polyvinyl chloride and polyvinylidene chloride resins, acrylic resins, urethane resins, fluororesins, polyester resins, polyamide resins, Examples thereof include vinyl acetate resin. These may be used alone or in combination of two or more.

  Moreover, in order to ensure durability of an adhesive sheet, a member layer (B) needs to have high adhesive force with the adhesive layer (c2) arrange | positioned on this. Therefore, among the resins used for the member layer (B), it is preferable to use a material that can exhibit a high adhesive force to the pressure-sensitive adhesive layer (c2).

  In the member layer (B), examples of the material having a function used together with the resin include a polarizer, a reflective particle, an antireflection agent, an antiglare agent, a release agent, a conductive agent, a hard coat agent, a refractive index adjusting agent, Heat radiation agent, UV curing agent, UV absorber, light stabilizer, antioxidant, decoration / color material, photocatalyst, radiation shielding agent, electromagnetic wave shielding agent, electromagnetic wave absorbing material, rust preventive agent, self-healing material, oxygen scavenger , Percutaneous absorption agents and anti-adhesion agents. These may be used alone or in combination of two or more. Depending on the type of resin used for the member layer (B) or the purpose of use of the pressure-sensitive adhesive sheet, a material having a function for the member layer (B) may not be used.

  The member layer (B) is usually a single layer as shown in FIG. 1, but may be a multilayer of two or more layers. The thickness of the member layer (B) is not particularly limited, but is generally about 5 to 1000 μm, more preferably 10 to 500 μm, and particularly preferably about 25 to 200 μm for reasons such as facilitating the pasting operation. . Even in the case of two or more layers, the total thickness of the layers is preferably in this range. In the present invention, the tensile strength of the member layer (B) is not particularly required, and may be, for example, 100 N / 25 mm or less, further 30 N / 25 mm or less, particularly 10 N / 25 mm or less. It may be. The lower limit of the tensile strength of the member layer (B) is usually 1 N / 25 mm.

<Adhesion layer C>
As shown in FIG. 1, the pressure-sensitive adhesive layer (C) has a structure in which a pressure-sensitive adhesive layer (c2) / core material (c1) / pressure-sensitive adhesive layer (c2) are laminated in this order. It is a feature. The pressure-sensitive adhesive layer (c2) and the core material (c1) constituting the pressure-sensitive adhesive layer (C) will be described in detail below.

[Core material c1]
The core material (c1) is provided between the two pressure-sensitive adhesive layers (c2). As such a core material (c1), a material having both appropriate flexibility and strength may be used. For example, paper, non-woven fabric, synthetic fiber, film, metal foil can be used.

  Examples of the paper include glassine paper, high-quality paper, craft paper, art paper, coated paper, and synthetic paper. Nonwoven fabrics include, for example, wet nonwoven fabrics using fibers such as rayon, pulp, hemp, and vinylon, dry nonwoven fabrics mainly using synthetic resin fibers such as polyester, polypropylene, polyethylene, and nylon, which are long fibers, spunbond, and needle punches. , Water punch and span lace. The nonwoven fabric core material may be composed of one type of fiber, or may be composed of two or more types of fibers. Examples of the synthetic fiber include rayon fiber, nylon fiber, polyester fiber, and acrylic fiber.

  Examples of the film include polyolefin resins such as polypropylene, polyethylene, polycycloolefin, and ethylene-vinyl acetate copolymer; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyvinyl alcohol, triacetyl cellulose, and polyvinyl chloride. Resin, polycarbonate resin, polynorbornene resin, polyarylate resin, acrylic resin, urethane resin, acrylic / urethane resin, polyphenylene sulfide resin, polystyrene resin, vinyl resin, polyamide resin, polyimide resin, etc. Examples thereof include resins and resins obtained by combining these resins.

  Examples of the metal foil include malleable / ductile metals such as aluminum, copper, silver, and gold, and alloys thereof.

The basis weight of the core material (c1) is 1 g / m ^{2 to} 200 g / m ² , further 3 g / m ^{2 to} 150 g / m ² , especially 4 g in terms of securing sufficient strength and suppressing interlaminar fracture. / M ^{2 to} 80 g / m ² is preferable. If the basis weight is too small, the strength of the core material (c1) tends to decrease and the peelability tends to decrease, and if too large, the flexibility tends to decrease. The thickness of the core material (c1) is appropriately set in the range of 1 to 150 μm, further 3 to 100 μm, particularly 4 to 50 μm depending on the application. If the thickness is too thin, the strength of the core material (c1) tends to decrease and the peelability tends to decrease, and if it is too thick, the flexibility tends to decrease. Furthermore, the tensile strength of the core material (c1) is preferably 5 N / 25 mm or more, particularly preferably 10 to 1500 N / 25 mm, more preferably 20 to 1000 N / 25 mm. If the tensile strength is too small, the peelability tends to decrease, and if it is too large, the flexibility tends to decrease. In addition, the tensile strength of a core material (c1) can be measured by JIS-C-2151.

[Adhesive layer c2]
As shown in FIG. 1, the pressure-sensitive adhesive layer (c2) is provided on both surfaces of the core material (c1). One of them adheres to the member layer (B) and the other adheres to the adherend. As a material for such an adhesive layer (c2), for example, an acrylic adhesive and a rubber adhesive are preferably used. The pressure-sensitive adhesive layer (c2) may be formed of the same material on both surfaces of the core material (c1) or may be formed of different materials. From the viewpoint of not complicating the production process, the pressure-sensitive adhesive layer (c2) is preferably formed of the same material on both sides of the core material (c1).

  As the acrylic pressure-sensitive adhesive, for example, an acrylic polymer obtained by polymerizing a carboxyl group-containing monomer and a (meth) acrylic acid alkyl ester monomer can be suitably used. Examples of the carboxyl group-containing monomer include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid; dicarboxylic acids such as fumaric acid and maleic acid, and monoesters thereof. Moreover, as said (meth) acrylic-acid alkylester monomer, C1-C20 of an alkyl group, especially 4-15, Furthermore, the thing of 6-12 is desirable, Specifically, n-butyl (Meth) acrylate (“(meth) acrylate” is a general term for acrylate and methacrylate. The same shall apply hereinafter), isobutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl ( Examples thereof include meth) acrylate and isononyl (meth) acrylate.

  Examples of the rubber-based pressure-sensitive adhesive include those obtained by blending a tackifier with an elastomer. Examples of elastomers include styrene-based thermoplastic elastomers such as styrene-isobutylene-styrene block copolymer (SIS) and styrene-butadiene-styrene block copolymer (SBS), natural rubber, butyl rubber, isobutylene rubber, and isopropylene rubber. Can be used, and it can also be used as a mixture of one or more.

In the present invention, the weight-average molecular weight of the pressure-sensitive adhesive resin forming the pressure-sensitive adhesive layer (c2) is preferably 50,000 or more in terms of the balance between the pressure-sensitive adhesive force and the cohesive force, particularly 150,000 to 1,500,000. Furthermore, it is preferable that it is 200,000 to 1,000,000.
The glass transition temperature of the pressure-sensitive adhesive resin forming the pressure-sensitive adhesive layer (c2) is preferably −10 ° C. or lower, particularly −20 ° C. or lower, and more preferably −30 ° C. or lower. If the glass transition temperature is too high, the tackiness of the resulting pressure-sensitive adhesive layer (c2) tends to be insufficient, and sticking to the adherend tends to be difficult. The “weight average molecular weight” can be determined by a GPC (gel permeation chromatography) method. The “glass transition temperature” can be measured according to JIS-K7121.

  For these pressure-sensitive adhesives which are materials for the pressure-sensitive adhesive layer (c2), for example, a cross-linking agent such as a polyisocyanate compound, an aziridine compound or a metal chelate compound may be used as long as the object of the present invention is not impaired. And tackifiers, coupling agents, fillers, softeners, plasticizers, surfactants, antioxidants (anti-aging agents), heat stabilizers, light stabilizers, UV absorbers, colorants, antifoaming 1 type, or 2 or more types of various additives, such as an agent, a flame retardant, and an antistatic agent, can be mix | blended.

  Examples of the tackifier include rosin, rosin ester, hydrogenated rosin ester, phenolic resin, aromatic modified terpene resin, aliphatic petroleum resin, alicyclic petroleum resin, aromatic petroleum resin, and styrene resin. , Xylene resins and coumarone indene resins. Examples of the softener include petroleum softeners, vegetable oil softeners, liquid rubber, and liquid tackifier resins.

  In addition, among the pressure-sensitive adhesive layers (c2) provided on both surfaces of the core material (c1), the one disposed on the member layer (B) side is to prevent damage to the pressure-sensitive adhesive sheet. It is desirable that the adhesiveness is high. For example, if the member layer (B) is made of a polyurethane resin having a low polarity, the pressure-sensitive adhesive layer (c2) in contact with the member layer (B) is made of a pressure-sensitive adhesive having a polarity close to that of the polyurethane resin such as rubber or acrylic. Then, at the interface of the polyurethane resin, the polymer chain of the adhesive diffuses into the polyurethane resin phase, and conversely, the polymer chain of the polyurethane resin diffuses into the adhesive phase. When mutual diffusion occurs in both layers, entanglement of polymer chains occurs at the interface between both layers, and mutual attractive force due to van der Waals force, hydrogen bonding, etc. is exhibited, so that the adhesion between both layers is higher. can do.

  Furthermore, in order to prevent damage to the pressure-sensitive adhesive sheet, it is desirable that the pressure-sensitive adhesive layer (c2) has high adhesiveness with the core material (c1).

  The thickness of the pressure-sensitive adhesive layer (c2) is usually preferably 1 μm to 500 μm, particularly 5 to 100 μm, and more preferably 10 to 50 μm. That is, if the thickness of the pressure-sensitive adhesive layer (c2) is too thin, the tackiness, adhesiveness and curved surface tackiness tend to decrease. Conversely, if the thickness is too thick, the tackiness and the like are no longer improved. This is because costs tend to be high. The thickness of the pressure-sensitive adhesive layer (c2) is preferably in the range of 0.01 to 100 times the thickness of the core material (c1), more preferably in the range of 0.1 to 10 times. More preferably, it is in the range of 5 times. When the thickness of the pressure-sensitive adhesive layer (c2) is too thick with respect to the thickness of the core material (c1), the cohesive force tends to decrease and the peelability tends to decrease. This is because of a tendency to decrease.

<Release liner D>
The release liner (D) covers the surface of the pressure-sensitive adhesive layer (c2) and protects the surface, but is removed and discarded when the pressure-sensitive adhesive sheet is attached to the adherend. . Therefore, it is required that the release liner (D) can be easily peeled from the pressure-sensitive adhesive layer (c2) and that the pressure-sensitive adhesive layer (c2) remains little on the release liner (D). In addition, it can peel easily here means 180 degree peeling adhesive strength (measured according to JIS-Z0237 at a peeling speed of 300 mm / min) of 0.005 N / 50 mm or more and 5 N / 50 mm or less. Say.

  As the release liner (D), for example, a release paper obtained by applying a silicone-based or non-silicone-based release agent on a support substrate such as various plastic films such as polyethylene terephthalate and oriented polypropylene, or paper is suitable. Used. As such release paper, for example, film biner series, bina sheet series (manufactured by Fujimori Kogyo Co., Ltd.), Tosero Separator SP series (manufactured by Tosero Co., Ltd.), Smithies series (manufactured by Sumika Kogyo Co., Ltd.), separate paper Commercial products such as (manufactured by Shinomura Chemical Co., Ltd.) and general release film (manufactured by Fujiko Co., Ltd.) can also be used.

  More specifically, examples of the support substrate include polyethylene resins such as high density polyethylene, low density polyethylene, and linear low density polyethylene; polyolefin resins such as polypropylene and poly-4-methylpentene-1; various polyamides Resins (so-called “nylon”, etc.); polyester resins such as polyethylene terephthalate; styrene resins such as polystyrene; films or sheets made of polyvinyl chloride resin, semi-bleached paper, high-quality paper, glassine paper, etc. Can give. These support base materials may be used alone or in combination of two or more.

  The thickness of the support substrate is preferably 10 to 300 μm, more preferably 25 to 200 μm, and further preferably 50 to 150 μm from the viewpoint of making the whole thinner. If the thickness is too thin, the strength of the release liner (D) tends to decrease, and if it is too thick, the flexibility tends to decrease and the handling becomes difficult, and the cost tends to increase.

  By having this configuration, the pressure-sensitive adhesive sheet of the present invention can be applied evenly to the adherend, and can exhibit excellent adhesiveness even when the adherend has a curved surface. Further, even when the attached pressure-sensitive adhesive sheet is peeled off from the adherend, the glue (pressure-sensitive adhesive layer c2) does not remain on the adherend and the pressure-sensitive adhesive sheet itself is not damaged. For this reason, as a base material (member layer B etc.) which is a part which ensures the function of an adhesive sheet, a thing with small tensile strength can be used, and the width | variety of the design of an adhesive sheet can be expanded. Moreover, since an adhesive sheet can be peeled off reasonably, high adhesive strength is required between a support film (A) and a member layer (B) which comprises the base material which is a part which ensures the function of an adhesive sheet. In addition, the width of the adhesive sheet design can be further expanded.

  In addition, when a softness | flexibility and a lightweight property are calculated | required by an adhesive sheet, as shown in FIG. 2, a support film (A) is not provided but a member layer (B), an adhesive layer (C), a release liner (D ). However, in this configuration, when the adhesive sheet is attached to the adherend, the member layer (B) is directly exposed to the outside, so that the member layer (B) has higher weather resistance and durability than the adhesive sheet of FIG. Sex is required. Therefore, it is necessary to sufficiently consider the selection of the material for forming the member layer (B) and the formation method thereof.

  The adhesive sheet (refer FIG. 1) shown in embodiment of this invention can be manufactured as follows, for example. That is, first, a double-sided pressure-sensitive adhesive sheet β (FIG. 5 (II)) comprising a color sheet α (FIG. 3) comprising a support film (A) and a member layer (B), and a release liner (D) and a pressure-sensitive adhesive layer (C). ) Separately. Then, the release liner (D) is peeled off from one surface of the double-sided pressure-sensitive adhesive sheet β, the pressure-sensitive adhesive layer (c2) is exposed, and the pressure-sensitive adhesive layer (c2) that appears is used as the member layer (B) of the color sheet α. (FIG. 6), the support film (A), the member layer (B), the pressure-sensitive adhesive layer (c2), the core material (c1), the pressure-sensitive adhesive layer (c2), and the release liner (D) in this order. The provided adhesive sheet can be manufactured. The method for producing this pressure-sensitive adhesive sheet will be described in detail below.

[Production of color sheet α]
First, production of the color sheet α will be described. On the prepared support film (A), the resin composition used as the material for forming the member layer (B) is cast-coated and dried. Thereby, the color sheet (alpha) by which the member layer (B) was laminated | stacked on the support film (A) as shown in FIG. 3 can be obtained.

[Production of double-sided adhesive sheet β]
Next, production of the double-sided pressure-sensitive adhesive sheet β will be described. On the prepared release liner (D), a pressure-sensitive adhesive composition (in this example, an isocyanate compound), which is a material for forming the pressure-sensitive adhesive layer (c2), is applied and dried. Thereby, the laminated body by which the adhesive layer (c2) was laminated | stacked on release liner (D) as shown in FIG. 4 can be obtained. The same thing as this laminated body is produced similarly. Next, a core material (c1) is prepared, and as shown in FIG. 5 (I), each of the two laminates is arranged so that the pressure-sensitive adhesive layer (c2) faces the core material (c1). Then, the pressure-sensitive adhesive layer (c2) surface of these laminates is pressed against the front and back surfaces of the core material (c1), and the core material and the laminate are bonded using the adhesive force of the pressure-sensitive adhesive layer (c2). Glue and unite. Thereby, the double-sided adhesive sheet (beta) which provided the adhesive layer (c2) on both surfaces of the front and back of a core material (c1) can be obtained [FIG. 5 (II)]. In addition, you may give an aging process to the adhesive layer (c2) formed in both surfaces of the core material (c1) as needed, in order to improve adhesiveness with a member layer (B).

  A method of applying the resin composition as the material for forming the member layer (B) on the support film (A), and a pressure-sensitive adhesive composition as the material for forming the pressure-sensitive adhesive layer (c2) of the release liner (D). A general coating method can be used as a method of coating on top. Examples of such an application method include roll coating, die coating, gravure coating, comma coating, and screen printing.

[Preparation of adhesive sheet]
Then, a color sheet α and a double-sided pressure-sensitive adhesive sheet β are prepared, and one of the release liners (D) covering the front and back surfaces of the double-sided pressure-sensitive adhesive sheet β (FIG. 5 (II)) is peeled off, and FIG. As shown, the exposed pressure-sensitive adhesive layer (c2) is pressed against the member layer (B) side of the color sheet α. Thereby, the color sheet (alpha) and the double-sided adhesive sheet (beta) are integrated, and the adhesive sheet shown in FIG. 1 can be obtained.

  In the above example, the double-sided pressure-sensitive adhesive sheet β was prepared by applying the pressure-sensitive adhesive composition on the release liner (D) and drying to form the pressure-sensitive adhesive layer (c2), and then forming the core material ( Although c1) is sandwiched, it may be produced by other methods. For example, a direct method of directly applying and drying the pressure-sensitive adhesive composition on the core material (c1), and applying and drying the pressure-sensitive adhesive composition on the release liner (D), the pressure-sensitive adhesive layer (c2) ) Is formed, and the core material (c1) is stacked on the pressure-sensitive adhesive layer (c2) and pressed to transfer the pressure-sensitive adhesive layer (c2) onto the core material (c1).

  Further, without producing the color sheet α and the double-sided pressure-sensitive adhesive sheet β, the pressure-sensitive adhesive sheet shown in FIG. 1 is produced by sequentially laminating the following layers on the prepared support film (A). It may be. However, as in the above example, the pressure-sensitive adhesive layer (C) is produced in a so-called double-sided tape (double-sided pressure-sensitive adhesive sheet β), and then the pressure-sensitive adhesive layer (c2) is adhered to the member layer (B), It is preferable from the viewpoint of simplifying the manufacturing process that the color sheet α and the double-sided pressure-sensitive adhesive sheet β are bonded and integrated to obtain a pressure-sensitive adhesive sheet.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In Examples and Comparative Examples, “parts” and “%” mean weight basis.

  First, before the production of Examples and Comparative Examples, the following color sheets α1 to α3 were prepared, and the sheet strength, interlayer adhesion strength, and adhesion were measured or evaluated as described below. These are shown together in Table 1 below.

<Color sheet α1>
To 100 parts (solid content) of polyurethane resin “Daishin Seika Kogyo Co., Ltd., Resamine ME-3412LP”, 20 parts of color base “Resino Color Industry Co., Ltd., Black OU-426”, 50 parts of toluene, 50 parts of methyl ethyl ketone ( MEK) was added and kneaded using a three-roll mill to obtain a resin composition. The obtained resin composition was cast-coated on the easy adhesion treated surface of the support film (A) 25 μm-thick PET film “Teijin DuPont Films, Teijin Tetron Film 25 μm-thick HPE” manufactured by Teijin DuPont Film Co., Ltd. Was dried for 5 minutes to form a member layer (B) having a thickness of 25 μm to obtain a color sheet α1.

<Color sheet α2>
A color sheet α2 was obtained in the same manner as the color sheet α1, except that the thickness of the member layer (B) was changed to 40 μm.

<Color sheet α3>
The thickness of the member layer (B) is changed to 60 μm, and instead of using the support film (A), a 25 μm-thick PET film base release liner (D) “Fujiko Co., Ltd., PET-25-S-01” is used. Formed a member layer (B) in the same manner as the color sheet α1, and then removed the release liner (D) to obtain a color sheet α3.

[Sheet strength]
The sheet strengths of these color sheets α1 to α3 were measured according to JIS-K7127. That is, the tensile strength in the MD direction (flow direction) of each color sheet α was measured under the conditions of 23 ° C., 50% RH and a tensile speed of 200 mm / min.

[Interlayer adhesion strength]
The adhesive strength between the support film (A) and the member layer (B) in the color sheets α1 and α2 was measured according to JIS-K6854-3. That is, a 25 μm thick polyester film base adhesive tape (made by Nitto Denko Corporation, polyester adhesive tape NO. 31B) having the same size as the test piece was respectively crimped to the entire surface of the member layer (B) of each color sheet α, By pulling this polyester film base adhesive tape perpendicularly to the color sheet α, the T-type peel adhesion between the support film (A) and the member layer (B) is 23 ° C., 50% RH, and the pulling speed is 300 mm. It measured on condition of / min. The color sheet α3 is not measured because the support film (A) is not used.

[Adhesion]
The adhesion between the support film (A) and the member layer (B) in the color sheets α1 and α2 was evaluated based on the following indices. That is, first, 100 1-mm square grids were formed by scratching the surface of the member layer (B) of the color sheet α with a cutter in accordance with JIS-K5600-5-6. Next, Nichiban Cello Tape (registered trademark) CT-24 was pressure-bonded to the member layer (B) on which the grids were formed. And when this cello tape (registered trademark) is pulled up at right angles to the pressure bonding surface and peeled off instantaneously, the number of grids remaining as a member layer (B) on the support film (A) is set as the following index. It was applied and evaluated. The color sheet α3 is not evaluated because the support film (A) is not used.
○: All grids of the member layer (B) remain on the support film (A).
Δ: 80 or more grids of the member layer (B) remain on the support film (A).
X: Only 79 or less grids of the member layer (B) remain on the support film (A).

  That is, the color sheets α1 and α2 are not so high in interlayer adhesive strength between the member layer (B) and the support film (A), and are inferior in adhesion. Further, the color sheet α3 not using the support film (A) has a sheet strength of 25 N / 25 mm and is inferior in strength.

  Using these prepared color sheets α1 to α3, pressure-sensitive adhesive sheets of Examples 1 to 6 and Comparative Examples 1 to 3 were produced as shown below. The obtained Example product and Comparative product were measured or evaluated as shown below for three items of adhesive strength, peelability, and curved surface adhesiveness. The results are shown in Table 2 below.

<Example 1>
Acrylic system comprising a copolymer of 2-ethylhexyl acrylate (HA) / butyl acrylate (BA) / acrylic acid (AA) (weight ratio: 10/88/2, weight average molecular weight 650,000, glass transition temperature -55 ° C.) Adequate 100 parts of adhesive solution (about 50% ethyl acetate / toluene mixed solution) and 2 parts of isocyanate compound (trimethylolpropane and tolylene diisocyanate trimer adduct, about 55% ethyl acetate solution) as a crosslinking agent To prepare a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was applied onto a release liner (D) “Shinomura Chemical Co., Ltd., release paper SSW-70FOMT”, dried at 100 ° C. for 1 minute in a hot air circulation dryer, and the thickness was about A laminate in which a 13 μm pressure-sensitive adhesive layer (c2) was laminated on the release liner (D) was obtained (see FIG. 4). Two laminates were produced. And these laminated bodies are laminated | stacked using both adhesive layers (c2) on both surfaces of 4 micrometer-thick polyester film "Toray Co., Ltd. Lumirror F53" which is a core material (c1) (FIG. 5 (I )), And aged for 7 days at 23 ° C. and 50% RH to obtain a double-sided PSA sheet β (see FIG. 5 (II)). The release liner (D) is removed from one side of the obtained double-sided pressure-sensitive adhesive sheet β, and the adhesive layer (c2) exposed is used to laminate on the member layer (B) surface of the prepared color sheet α1. The target adhesive sheet was produced by laminating with a roll (see FIG. 1).

<Examples 2 and 3>
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the coating thickness of the pressure-sensitive adhesive composition and the type (thickness) of the core material (c1) were changed as shown in Table 2 below.

<Example 4>
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition was changed as shown in Table 2 below. That is, as the pressure-sensitive adhesive composition, a styrene-based thermoplastic block copolymer “Clayton G1657 manufactured by Kraton Polymer Japan Co., Ltd.” (styrene-ethylene / butylene-styrene copolymer (SEBS), weight average molecular weight 150,000, styrene content 15%) 80 Example 1 except that a rubber-based adhesive solution (approximately 30% toluene mixed solution) consisting of 20 parts of an alicyclic saturated hydrocarbon resin “P-115 manufactured by Alcon Arakawa Chemical Industries, Ltd.” was used. I made it.

<Examples 5 and 6>
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the color sheet α1 was changed as shown in Table 2 below. That is, the pressure-sensitive adhesive sheet of Example 5 has the configuration shown in FIG. 1, and the pressure-sensitive adhesive sheet of Example 6 has the configuration shown in FIG.

<Comparative Example 1>
The pressure-sensitive adhesive composition was applied thickly on the release liner (D), and only one laminate was produced in which the pressure-sensitive adhesive layer (c2) having a thickness of about 30 μm was laminated on the release liner (D). Then, the core material (c1) was not used (the double-sided pressure-sensitive adhesive sheet β was not produced), but the adhesive layer (c2) surface was directly bonded to the member layer (B) surface of the color sheet α1. A target pressure-sensitive adhesive sheet was produced in the same manner as in Example 1. That is, the pressure-sensitive adhesive sheet of Comparative Example 1 is the conventional product itself shown in FIG.

<Comparative Examples 2 and 3>
A pressure-sensitive adhesive sheet was obtained in the same manner as in Comparative Example 1 except that the color sheet α1 was changed as shown in Table 2 below. These are the conventional products themselves as shown in FIG.

[Adhesive strength (N / 25mm)]
In accordance with JIS-Z0237, the pressure-sensitive adhesive sheet is pressure-bonded to a mirror-finished product (adhered body) with a stainless steel plate 304, and the adhesive strength when peeled 180 ° after 24 hours at 23 ° C. and 50% RH. Was measured.

[Peelability]
The surface of the adherend and the pressure-sensitive adhesive sheet after measuring the adhesive strength (N / 25 mm) were observed and evaluated according to the following indices.
○: Interfacial peeling of the adherend / adhesive layer (c2) was observed.
Δ: Interlaminar fracture between the support film (A) / member layer (B) was observed.
X: Destruction of the adhesive sheet itself was observed.

(Curved surface adhesiveness)
The pressure-sensitive adhesive sheet was cut into a size of 10 mm × 20 mm to prepare a test piece. This test piece was affixed to a polyethylene rod of φ = 10 mm. And the state of the test piece after 24 hours was observed and evaluated according to the following index.
○: The entire surface of the test piece is firmly attached to the polyethylene rod.
Δ: A part of the test piece is peeled off from the polyethylene rod.
X: A majority of the test piece is peeled off from the polyethylene rod.

  From the above results, the example products may use the color sheets α1 and α2 that are inferior in interlayer adhesion strength and adhesion between the support film (A) and the member layer (B), or the color sheet α3 that is inferior in sheet strength. It has excellent adhesive strength, peelability and curved surface adhesiveness. On the other hand, it turns out that the comparative example goods are inferior about most items.

  The pressure-sensitive adhesive sheet of the present invention is excellent in pressure-sensitive adhesiveness, peelability and curved surface pressure-sensitive adhesiveness. For this reason, it can be used as a protective sheet or the like that can be easily pasted. Further, it can be suitably used as a management label between processes for producing a product and a distribution label at the time of distribution, which are peeled off when they are no longer needed.

B Member layer C Adhesive layer c1 Core material c2 Adhesive layer

Claims (10)

  A pressure-sensitive adhesive sheet having a layer structure of member layer (B) / pressure-sensitive adhesive layer (C), wherein the pressure-sensitive adhesive layer (C) is a layer of pressure-sensitive adhesive layer (c2) / core material (c1) / pressure-sensitive adhesive layer (c2). A pressure-sensitive adhesive sheet having a configuration.   A pressure-sensitive adhesive sheet having a layer structure of support film (A) / member layer (B) / pressure-sensitive adhesive layer (C), wherein the pressure-sensitive adhesive layer (C) is pressure-sensitive adhesive layer (c2) / core material (c1) / pressure-sensitive adhesive. A pressure-sensitive adhesive sheet having the layer structure of the layer (c2).   The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer (C) is a double-sided pressure-sensitive adhesive sheet (β) in which a pressure-sensitive adhesive layer (c2) is formed on both surfaces of the core material (c1).   The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the core material (c1) has a tensile strength of 5 N / 25 mm or more.   The thickness of a core material (c1) is 1-150 micrometers, and the thickness of an adhesive layer (c2) is 1-500 micrometers, The adhesive sheet as described in any one of Claims 1-4 characterized by the above-mentioned.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the thickness of the pressure-sensitive adhesive layer (c2) is 0.01 to 100 times the thickness of the core material (c1).   The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (c2) is at least one of an acrylic pressure-sensitive adhesive and a rubber pressure-sensitive adhesive.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the member layer (B) has a tensile strength of 100 N / 25 mm or less.   The pressure-sensitive adhesive sheet according to any one of claims 2 to 8, wherein an interlayer adhesive strength of the support film (A) / member layer (B) is 10 N / 25 mm or less. The pressure-sensitive adhesive sheet according to any one of claims 1 to 9, wherein a release liner (D) is provided outside the pressure-sensitive adhesive layer (C).

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