JP2003313521A - Adhesive sheet and laminate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet which can exhibit an ordinary adhesive force in a state laminated to an adherend and can easily be peeled, removed and recovered from the adherend, when used and scraped. <P>SOLUTION: This adhesive sheet 1 is prepared by sequentially laminating a sheet-like substrate 2, a foaming agent-containing or ionic radiation-curable primer layer 3, and an adhesive layer 4. When a laminate 6 prepared by laminating the adhesive sheet 1 to an adherend 5 is heated or irradiated with ionizing radiations, the adhesive force of the primer layer 3 can be lowered to facilitate the peeling of the adhesive sheet. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a case where a pressure-sensitive adhesive layer is used for laminating with an adherend, the layer may be laminated via a primer layer having a property that the adhesive force is lowered by energy applied from the outside. The present invention relates to a possible pressure-sensitive adhesive sheet and a laminate in which the pressure-sensitive adhesive sheet is attached to an adherend by using such a primer layer.

[0002]

2. Description of the Related Art Since a pressure-sensitive adhesive sheet is a sheet-shaped material to which an adhesive has been applied in advance, each time the sheet-shaped material is attached to an adherend, the time and effort required to apply the adhesive are released. It has the advantage that it is used for various purposes.

In the state of a laminated body laminated with an adherend, the pressure-sensitive adhesive sheet has an adhesive force that is not easily peeled off by being touched by a person or applying an unexpected external force. It is often desired and has fairly strong adhesion. However, it is desirable that the adhesive strength of the laminated body of the pressure-sensitive adhesive sheet and the adherend is high during the use as a laminated body, but when it is discarded after use, the adherend and the adherend are adhered. It is a disadvantage that the sheet is peeled off and it is difficult to separate and collect the sheet.

[0004]

Therefore, in the present invention, a normal adhesive force can be exerted in a state of being laminated with an adherend, and when it is used and discarded, it is removed from the adherend. An object of the present invention is to provide a pressure-sensitive adhesive sheet that can be easily peeled and can be separately collected.

[0005]

Means for Solving the Problems As a result of various studies on a method of laminating a pressure-sensitive adhesive sheet on an adherend, the inventor found that by interposing a primer layer having a property of lowering adhesive strength due to ultraviolet rays or the like in a laminated structure, While having a strong adhesive force in a normal state, by applying energy such as ultraviolet rays from the outside, the adhesive force of the primer layer can be reduced,
Therefore, it has been found that it becomes possible to easily separate the pressure-sensitive adhesive sheet and the adherend, and the present invention has been reached.

The first invention is a primer layer having a property that the adhesive force is reduced by the energy applied from the outside on the surface of the sheet-shaped substrate, and the adhesive force is not substantially changed by the energy applied from the outside. The present invention relates to a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer laminated in order. A second invention relates to the pressure-sensitive adhesive sheet according to the first invention, wherein the primer layer contains a thermal decomposition type foaming agent or an ionizing radiation decomposition type foaming agent. A third invention relates to the pressure-sensitive adhesive sheet according to the first invention, wherein the primer layer is an ionizing radiation-curable adhesive. A fourth invention relates to a laminate, wherein the pressure-sensitive adhesive sheet according to any one of the first to third inventions is laminated on an adherend such that the pressure-sensitive adhesive layer faces the adherend side. is there. A fifth aspect of the present invention is a pressure-sensitive adhesive layer or adhesive layer on which the adhesive force is not substantially changed by the energy applied from the outside on the adherend, and a primer having a property that the adhesive force is decreased by the energy applied from the outside. The present invention relates to a layered product in which a layer and a sheet-shaped substrate are layered in order. A sixth invention is, on an adherend, a primer layer having a property that the adhesive force is lowered by an energy applied from the outside, and a pressure-sensitive adhesive layer or an adhesive whose adhesive force is not substantially changed by the energy applied from the outside. The present invention relates to a layered product in which an agent layer and a sheet-shaped substrate are layered in order.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1 (a), a pressure-sensitive adhesive sheet 1 according to the present invention has a primer layer 3 on a sheet-shaped substrate 2.
And the pressure-sensitive adhesive layer 4 has a laminated structure in which they are laminated in order. Here, as will be described later, the primer layer 3 has a property that the adhesive force is reduced by the energy applied from the outside, and the pressure-sensitive adhesive layer 4 has a substantial adhesive force by the energy applied from the outside. It is a normal pressure-sensitive adhesive layer that does not decrease.

The pressure-sensitive adhesive sheet 1 is laminated so that the pressure-sensitive adhesive layer 4 contacts the adherend 5, that is, the pressure-sensitive adhesive sheet 1 described with reference to FIG. The laminated body 6 of the present invention is obtained by pressing and laminating. As shown in FIG. 1B, the laminated body 6 includes the adherends 5,
The adhesive layer 4, the primer layer 3, and the sheet-shaped substrate 2 have a laminated structure.

The above-mentioned sheet-like base material 2 is prepared separately from the adherend, and it is a sheet-like substrate which needs to be applied with an adhesive or pressure sensitive adhesive to be adhered onto the adherend. So long as it can be used. Industrially, the sheet-shaped substrate 2 is preferably one that can be supplied and handled in the form of a roll, and if it is general, it is a sheet such as paper, a plastic sheet, or a metal foil. In addition, a non-woven fabric, a cloth, other fibrous sheets, or a sheet such as a single plate obtained by thinly slicing wood can be used. Of the above, the plastic sheet may be colorless and transparent, colored and transparent, or opaque. These various sheets may be used alone or may be used as a composite sheet in which any combination is attached to each other, and a part or all of them are reinforced by coating or resin impregnation. Good. The thickness of the sheet-shaped base material 2 is about 5 μm to 500 μm, more preferably about 20 to 300 μm, though it depends on the material and the application. Further, when flexibility is not required, the upper limit can be further increased and is several mm, for example, about 5 mm or less.

Since the pressure-sensitive adhesive sheet 1 is used to coat the surface of an adherend and determines the appearance of the adherend, it may be required to have an aesthetic appearance depending on the use of the adherend. In such a case, as the sheet-shaped base material 2,
If necessary, it is preferable to use those having a color, pattern, or unevenness.

Similarly, since the pressure-sensitive adhesive sheet 1 can determine the physical or chemical properties of the surface of the adherend, it has necessary properties suitable for the application of the adherend. May be preferred. As such properties, in familiar places, various properties such as scratch resistance, antifouling property, antifogging property, heat insulation property, antireflection property, antistatic property, or electromagnetic wave shielding property, magnetic property, fluorescence emission property, etc. It may have various properties such as properties, moisture absorption and desorption, infrared or ultraviolet reflection or absorption, antibacterial properties, and antifungal properties. To impart these properties, a material having those properties may be selected as the sheet-shaped substrate 2, or a resin layer in which a substance having these properties is kneaded may be laminated by coating or the like. Good.

In the present invention, the primer layer 3 is used in the usual purpose of the primer layer 3, that is, in addition to improving and maintaining the adhesive force of the layers on both sides of the primer layer, the energy applied from the outside is also applied. By this, the adhesive strength is reduced, and it is intended to serve as a peeling portion when the pressure-sensitive adhesive sheet 1 and the adherend 5 are separated at the time of separation.

The primer layer 3 is roughly classified into (1) a foaming agent-containing adhesive or (2) an ionizing radiation-curable adhesive, and the former further comprises (1a) a thermal decomposition type foaming agent. It can be divided into those containing (1b) ionizing radiation decomposition type foaming agent.

As the thermal decomposition type foaming agent, an inorganic foaming agent such as sodium hydrogen carbonate, ammonium carbonate, sodium borohydride, silicon hydroxide or the like can be used. As the organic foaming agent, an azo compound such as azodicarbonamide, azobisisobutylnitrile, or diazobenzene, an azide compound such as paratoluenesulfonyl hydrazide, or 4,4-oxybisbenzenesulfonyl hydrazide, or nitrosopentamethylene. Examples thereof include tetramine and nitroso compounds such as N, N-dinitrosoterephthalamide.

As the ionizing radiation-decomposable foaming agent, the heat-decomposable foaming agent described above may be used, if necessary, with an ultraviolet absorber.

The above-mentioned thermal decomposition type foaming agent or ionizing radiation decomposition type foaming agent is dissolved or dispersed in the resin forming the usual primer layer to form the primer layer 3. As a resin for forming the primer layer, a polyester resin, a polyurethane resin, an acrylic resin, a polycarbonate resin, a vinyl chloride / vinyl acetate copolymer resin, a polyvinyl butyral resin, a nitrocellulose resin, or the like can be used. Ethyleneimine compounds can also be used. A thermal decomposition type foaming agent or an ionizing radiation decomposition type foaming agent is mixed with the resin 100 for forming a primer layer in a ratio of 1 to 10 (mass basis) and dissolved or dispersed with a solvent or a diluent to form a primer layer. The composition for forming is coated on the sheet-shaped substrate 2 by a known coating method and dried to form the primer layer 3. The thickness of the primer layer 3 is 1 μm to 10 μm
It is preferable that

When the primer layer 3 is composed of an ionizing radiation-curable pressure-sensitive adhesive, examples of the ionizing radiation-curable pressure-sensitive adhesive include styrene, methylstyrene, (meth) acrylic acid, or a monofunctional monomer such as an alkyl ester or aryl ester thereof. Or more functionalized (meth) acryloyl monomer obtained by reacting (meth) acrylic acid or a derivative thereof with a functionalized compound such as ethylene glycol, glycerin, pentaerythritol, or epoxy resin, and (meth) in the molecule. Contains an ionizing radiation-curable compound such as a polyurethane-based, polyester-based, polyether-based, polycarbonate-based, or poly (meth) acrylic acid ester-based oligomer or prepolymer having a radical-polymerizable double bond such as an acryloyl group Can be used , For example, it used as a mixture with normal adhesive. These ionizing radiation-curable compounds are preferably contained in 10 to 90% of the total amount of the ionizing radiation-curable pressure-sensitive adhesive, and more preferably 20 to 60.
%. If necessary, additives such as a photopolymerization initiator can be blended and used. A known ultraviolet irradiation device or electron beam irradiation device may be used as the ionizing radiation source. Even when the ionizing radiation-curable pressure-sensitive adhesive is used, the thickness of the primer layer 3 is preferably 1 μm to 10 μm.

Even if this ionizing radiation-curable pressure-sensitive adhesive is directly applied to the sheet-shaped substrate 2 to form an ionizing radiation-curable pressure-sensitive adhesive layer, it is expected that the adhesive force will be lowered by the irradiation of ionizing radiation. However, since components that can cause polymerization or crosslinking in the pressure-sensitive adhesive layer remain unreacted, when such a pressure-sensitive adhesive sheet is attached to an adherend, the reaction proceeds over time and the cohesive force of the pressure-sensitive adhesive layer increases. The pressure-sensitive adhesive layer may be decreased, and since the pressure-sensitive adhesive layer is formed relatively thick, unreacted components may cause odor, which is not preferable. A similar tendency is conceivable in a primer layer composed of an ionizing radiation-curable pressure-sensitive adhesive, but the primer layer can be formed thinner than the pressure-sensitive adhesive layer, so there are few problems.

As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer 4 whose adhesive force is not substantially changed by the energy applied from the outside, a rubber-based adhesive, an acrylic-based adhesive starting from acrylic acid or an acrylic ester, or A known adhesive such as a silicone resin-based adhesive can be used. To apply the pressure-sensitive adhesive composition, known coating methods such as roll coating and knife coating are used. The thickness of the pressure-sensitive adhesive layer 4 is preferably 10 μm to 100 μm at the stage of drying after application, and when the thickness is less than 10 μm, the adhesive force when the pressure-sensitive adhesive sheet 1 is adhered to an adherend is insufficient and 100 μm. When it exceeds, no improvement in adhesive strength is observed.

The pressure-sensitive adhesive sheet 1 can be wound up in a roll shape, with the side opposite to the side on which the pressure-sensitive adhesive layer 4 of the sheet-shaped base material 2 is laminated being made releasable.
When used by cutting into an appropriate size or storing the separated adhesive sheets 1 one by one, it is preferable to laminate a peelable sheet on the adhesive layer 4, and by laminating,
Deterioration of the pressure-sensitive adhesive layer 4 is prevented, and a protective effect of preventing the pressure-sensitive adhesive layer 4 from being inadvertently touched and adhered to another object is produced. In the case of using a separable paper (= peeling sheet) having unevenness on the peeling surface, the peeling sheet is laminated at the time of manufacturing the pressure-sensitive adhesive sheet 1. In any case, examples of the peelable sheet include those obtained by laminating a peelable layer mainly composed of a silicone resin on the surface of an appropriate substrate such as a plastic film or paper, or a polyolefin resin film such as polyethylene film or polyethylene. A film such as a terephthalate resin film can be used.

Various materials can be used as the adherend 5 for forming the laminate 6. For example, the adherend 5 may be various plate-shaped bodies. As the material of the plate, a metal type such as aluminum or iron, a wood type such as wood, plywood, or a medium density fiber board, a gypsum board, a silica board,
Examples include ceramics such as glass or tiles. In addition, the materials mentioned as the material of the sheet-shaped base material 2 may be the material of the adherend 6. When targeting a building, the adherend 5 is a concrete frame, gypsum board,
Alternatively, it may be a lath base or the like. The adherend 5 may be a sheet or a film made of the same material other than the plate-like body as exemplified above. The adherend 5 is
It may be a laminated body in which the materials described above are arbitrarily combined and laminated.

When the pressure-sensitive adhesive sheet 1 is laminated on the adherend 5 and the pressure-sensitive adhesive sheet 1 can be supplied in a roll form and the adherend 5 is a plate which can be conveyed by a conveyor, the adherend 5 is conveyed. On the way, the pressure-sensitive adhesive sheet 1 is unrolled, overlapped on the adherend 5, and passed between the opposing rollers to apply pressure to press them together. When both the pressure-sensitive adhesive sheet 1 and the adherend 5 are cut, they may be pressure-bonded using a flat plate press and laminated. When the adherend 5 is a building, the adhesive sheet 1 cut into a predetermined size
May be superposed on the surface of the adherend 5 and pressure-bonded by a hand roller or the like. Any of the pressure bonding methods may be accompanied by heating, but it is preferable to heat within a range that does not impair the adhesive force of the primer layer 3.

In order to separate the adherend 5, the pressure-sensitive adhesive layer 4, the primer layer 3 and the sheet-shaped base material 2 laminated in this order, the primer layer 3 is used. The adhesive force of the primer layer 3 is reduced by externally applying energy according to the constituent materials to the adhesive sheet 1.
And the adherend 5 are separated.

When the primer layer 3 contains a thermal decomposition type foaming agent, the laminate 6 is heated to decompose the thermal decomposition type foaming agent in the primer layer 3 to form the primer layer 3. By foaming, the primer layer 3 expands and its cohesive force decreases. In addition, the primer layer 3 is
When the layered product 6 contains an ionizing radiation-decomposable foaming agent, the laminate 6 is irradiated with ionizing radiation to generate the primer layer 3.
By decomposing the ionizing radiation-decomposable foaming agent therein to foam the primer layer 3, the primer layer 3 expands and its cohesive force decreases. When the primer layer 3 is made of an ionizing radiation curable adhesive, the laminate 6
By irradiating the primer layer 3 of
The ionizing radiation curable adhesive is cross-linked and the cohesive force is reduced.
In either case, since the cohesive force of the primer layer 3 decreases, the pressure-sensitive adhesive sheet 2 and the adherend 5 can be separated between the layers of the primer layer 3, and the pressure-sensitive adhesive sheet 2 and the adherend 5 can be separated. You can

By laminating the adhesive sheet 1 and the adherend 5,
The method of forming the laminate 6 of the present invention does not require application of an adhesive each time it is laminated, and is suitable for manufacturing a pressure-sensitive adhesive sheet, particularly for forming a primer layer and a pressure-sensitive adhesive layer with a dedicated apparatus. However, even if only the primer layer 3 is formed on the sheet-shaped base material 2 and the pressure-sensitive adhesive layer 4 or the adhesive layer is formed on the adherend 5 and laminated on the adherend 5, the peeling can still be performed. Can be easy.

By applying energy from the outside to reduce the adhesive force of the primer layer and facilitate the peeling of the pressure-sensitive adhesive sheet from the adherend, it is necessary to adhere the primer layer 3 to the primer layer 3 in the above-mentioned laminate 6. The order of the agent layers 4 was changed,
On the laminate 6 ′, that is, the adherend 5, the primer layer 3, the pressure-sensitive adhesive layer 4 (or the adhesive layer), and the sheet-shaped substrate 2
Even if it has a laminated structure consisting of

In this case, a pressure-sensitive adhesive layer 4 is laminated on the sheet-shaped substrate 2, so to speak, an ordinary pressure-sensitive adhesive sheet and an adherend 5 are prepared, and after the primer layer 4 is formed on the adherend 5. If a pressure-sensitive adhesive sheet is attached or the primer layer 4 can be reactivated by applying a solvent, heating, or the like, a pressure-sensitive adhesive sheet in which the sheet-shaped substrate 2, the pressure-sensitive adhesive layer 4, and the primer layer 3 are laminated in order is used. It is also possible to manufacture the laminate by preparing it, reactivating the primer layer 3 and immediately pressing it on the adherend.

As the adhesive for forming an adhesive layer on the adherend, the adhesive strength of which is not substantially changed by the energy applied from the outside, polyvinyl acetate resin, ethylene-
Thermoplastic resin such as vinyl acetate copolymer resin, polyamide resin, or acrylic resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin,
Alternatively, a thermosetting resin such as a polyurethane resin, or a rubber-based material such as ethylene propylene rubber styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, or silicone rubber is used as the adherend 5 or the primer layer 4 The material selected according to the material of can be used.

[0029]

Example 1 On the back surface of a 100 μm thick decorative sheet made of polypropylene resin, azodicarbonamide in a polyurethane resin primer coating was added in an amount of 5% (mass basis) based on the resin content of the primer coating. The compounded and mixed product was applied to form a primer layer by applying a dry coating amount of 10 g / m ^2, and then as an adhesive, an acrylic adhesive (manufactured by Soken Chemical Co., Ltd., trade name;
"SKDyne 1309" (main ingredient) and curing agent (manufactured by the same company,
Product name; "E-AX") and main agent / hardener = 100/3
A coating amount of 100 g / m is obtained by blending (mass basis).
^It was applied so as to be ² to obtain a decorative adhesive sheet. The obtained pressure-sensitive adhesive sheet was pressure-bonded to the surface of a medium-quality fiberboard having a thickness of 12 mm, laminated, and cured for 1 week after lamination. Although the decorative adhesive sheet could not be peeled from the laminate in this state, when the hot plate having a temperature of 105 ° C. was pressure-contacted from the decorative adhesive sheet side and immediately peeled off, the decorative adhesive sheet was removed from the layers of the primer layer. The sheet could be easily peeled off.

(Example 2) A sheet having a primer layer formed on the back surface of a decorative sheet in Example 1 was used without applying an adhesive, and the same thickness 1 as in Example 1 was used.
A two-component curable polyurethane resin-based adhesive is applied to the surface of a 2 mm medium-quality fiberboard so that the resin content is 30 g / m ² , and once dried, the above-mentioned sheet is formed on the adhesive layer. When the primer layers were in contact with each other, they were pressure-bonded with a heating roller and laminated, and after curing for 1 week, the same results as in Example 1 were obtained.

[0031]

According to the first aspect of the present invention, the sheet-like base material has a structure in which the primer layer and the pressure-sensitive adhesive layer are laminated in this order, so that the sheet-like base material has sufficient adhesive force in a state of being adhered to an adherend. At the time of peeling, energy can be applied to the primer layer to reduce its adhesive force, thereby providing a pressure-sensitive adhesive sheet that can be easily separated. According to the invention of claim 2, in addition to the effect of the invention of claim 1, the primer layer contains a thermal decomposition type foaming agent or an ionizing radiation decomposition type foaming agent. By doing so, in the latter case, it is possible to provide a pressure-sensitive adhesive sheet that can reduce the adhesive force of the primer layer by irradiating with ionizing radiation. According to the invention of claim 3, in addition to the effect of the invention of claim 1, since the primer layer is composed of an ionizing radiation-curable adhesive, the adhesive force of the primer layer is reduced by irradiating with ionizing radiation. It is possible to provide a pressure-sensitive adhesive sheet. According to the invention of claim 4, claim 1
Since the pressure-sensitive adhesive sheet according to any one of claims 3 to 3 and the adherend are laminated, it is possible to provide a laminated body that has sufficient adhesive force and is easy to separate. According to the invention of claim 5, for example, an adherend and a sheet-like substrate with a primer layer are laminated via a pressure-sensitive adhesive layer or an adhesive layer,
It is possible to provide a laminated body that has sufficient adhesive strength and is easy to separate. According to the invention of claim 6, it has a laminated structure in which the primer layer is on the adherend side, and it is possible to provide a laminated body which has a sufficient adhesive force in the laminated state but is easy to separate.

[Brief description of drawings]

FIG. 1 is a diagram showing a laminated structure of an adhesive sheet and a laminated body.

FIG. 2 is a diagram showing a laminated structure of another laminated body.

[Explanation of symbols]

1 Adhesive sheet 2 Sheet-shaped substrate 3 Primer layer 4 Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 201/00 C09J 201/00 F term (reference) 4F100 AR00C AT00A AT00D BA03 BA04 BA07 BA10A BA10C BA10D CA01B EJ65B GB90 JB14B JL00 JL13C JL14 4J004 AB01 CD01 4J040 JA09 JB09

Claims (6)

[Claims] 1. A primer layer having a property of lowering the adhesive force by the energy applied from the outside, and a pressure-sensitive adhesive layer whose adhesive force is not substantially changed by the energy applied from the outside on the surface of the sheet-shaped substrate. A pressure-sensitive adhesive sheet, which is laminated in order. 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the primer layer contains a thermal decomposition type foaming agent or an ionizing radiation decomposition type foaming agent. 3. The pressure-sensitive adhesive sheet according to claim 1, wherein the primer layer is an ionizing radiation curable adhesive. 4. A laminate, wherein the pressure-sensitive adhesive sheet according to any one of claims 1 to 3 is laminated on an adherend with the pressure-sensitive adhesive layer facing the adherend side. 5. A pressure-sensitive adhesive layer or an adhesive layer whose adhesive force does not substantially change due to energy applied from the outside, and a primer layer having a property of decreasing the adhesive force due to energy applied from the outside. And a sheet-shaped substrate are sequentially laminated. 6. A primer layer having a property of lowering the adhesive force by an energy applied from the outside on an adherend, and a pressure-sensitive adhesive layer or an adhesive whose adhesive force is not substantially changed by the energy applied from the outside. A layered product in which a layer and a sheet-shaped substrate are layered in order.