TWI422663B - Removable pressure sensitive adhesive sheet - Google Patents

Description

Re-peeling adhesive sheet

The present invention relates to an adhesive sheet for re-peeling which can be peeled off after being adhered to an adhesive.

For the purpose of advertising for goods or services, it is used in packaging containers for cosmetics, cosmetics, beverages and foods, equipment installed in public places such as vending machines and automatic ticket machines, or in public places such as trams and automobiles. For vehicles, etc., stick the printed sheets of printed text or images. For these adhesive sheets, it is sought that after the adhesive is applied for a certain period of time, the adhesive does not remain on the adhesive, and the substrate sheet is not cut, and the peeling property is perfectly peeled off. However, in order to exhibit removability, in general, it is necessary to design a weak adhesive force, and if it adheres to an adhesive or a curved surface having irregularities, there is a problem that peeling occurs over time.

On the other hand, in the name of the product, or for the purpose of the user or the repairer's operating instructions or parts replacement procedures, in copiers, printers, fax machines, personal computers, televisions, air conditioners, refrigerators and Various electrical appliances such as washing machines; most of them are used in various related products such as toner cartridges or ink cartridges; or on various interior and exterior decorative parts such as automobiles, locomotives and building materials, and adhered to adhesive sheets. Since these adhesive sheets are used after being adhered for a long time, it is particularly required that during the adhesion to the adhesive, there is no floating occurrence or peeling between the adhesive sheet and the adhesive (hereinafter, there will be called floating peeling). In the case of the adhesion, it is generally practiced to remove the adhesive sheet.

However, in recent years, based on the care for the natural environment, it is strongly desired to recycle used products or parts or all of the parts constituting such products. For example, parts or members of various electrical products, parts or members of these various related products, and the like are formed by a thermoplastic resin to perform circulation or the like. Specifically, a disintegrator is used to disassemble used parts or components or parts or components that exceed the number of years of durability into pellets, heat-melt them, and then form them into certain parts or components. Reuse such recycled molded articles again. When the parts or the like are pulverized, the adhesive sheet is attached to the parts and the like, and the parts to which the adhesive sheet is pasted and the adhesive sheet are not melted, and the parts to be recycled by the impurities which are melted without being melted by heating are melted. The strength is not reduced and there is a need to remove the adhesive sheet. Therefore, it is conventionally known that the adhesive sheet is heated by a hair dryer to be peeled off, or scraped off by a grinder, and then the part or the like is scraped into pellets, and then melted to obtain a recycled molded article. However, the operation of peeling off the adhesive sheet from a part or the like is a troublesome and time-consuming operation which is extremely troublesome, whereby the recycling cost of the component is unavoidable. Therefore, when the adhesive sheet is peeled off, an adhesive is required. It does not remain on the adhesive, and the base material sheet is not cut, and can be easily peeled off again.

However, if only the re-peelability is emphasized, in the case of various electrical products and the like, the adhesive sheet may be adhered to the surface having the uneven surface on which the observed embossing is performed, or in the case of sticking to the curved adhesive. A problem with floating stripping occurred. In addition, since the gas generated from the thermoplastic resin constituting various electrical products and the like is released, it will occur in the temporarily adhered adhesive sheet. The problem of accumulating bubbles between the thermoplastic resin and the thermoplastic resin.

In order to solve such a problem, Patent Document 1 discloses an acrylic adhesive composition characterized by having 74.999 to 99.9% by mass of a (meth)acrylic acid alkyl monomer component with (meth)acrylic acid. 0 to 0.001% by mass of the carboxyl group-containing monomer copolymerizable with the ester monomer component, 0.1 to 5% by mass of the hydroxyl group-containing monomer copolymerizable with the (meth)acrylic acid alkyl ester monomer component, and the like 100 parts by weight of an acrylic copolymer obtained by radical copolymerization of a monomer component of 0 to 20% by mass of a copolymerizable monomer, and an acrylic adhesive containing 0.1 to 5 parts by weight of an isocyanate crosslinking agent The composition has a storage elastic modulus at 120 ° C of 2 × 10 ⁵ to 7 × 10 ⁵ dyn / cm ² and a loss tangent (tan δ ) of 0.05 to 0.4 in the dynamic viscoelastic spectrum measurement of the dry film of the adhesive composition. And the storage modulus at 0 ° C was 1 × 10 ⁵ to 4 × 10 ⁶ dyn / cm ² .

However, in the case of the adhesive-processed product disclosed in the above-mentioned Patent Document 1, although the removability is excellent, it is an image forming apparatus such as a copying machine, a printer, a facsimile machine, or the like, or various electrical products. Such an electronic machine has an uneven surface on which embossing is performed, and the adhesion is insufficient, and once it has been pasted for a long period of time, there will be a problem of being peeled off.

Further, an adhesive film for re-peeling (refer to Patent Document 2) is known, which is characterized in that the 180-degree peeling adhesion force with respect to the polymethyl methacrylate sheet is 0.2 N/25 mm to 5.0 N/25 mm, and the fixed load is fixed. The peeling length after 30 minutes in the peeling measurement method is 50 mm or less, and the adhesive film is attached to a polymethyl methacrylate plate, and after being left at room temperature for 1 hour, the peeling speed is set. 1m/min, peeling angle 180 degree peeling adhesive force is set to P1, after standing at 60 ° C for 24 hours, the peeling speed of 1m / min, peeling angle 180 degrees peeling when the adhesive force is set to P2 The ratio of P1 to P2 (P1/P2) is 1.4 to 0.7. This technique relates to an adhesive film for re-peeling which has excellent adhesiveness, does not cause floating peeling, and the like, and the adhesive does not contaminate the adhesive at the time of peeling, and has excellent removability.

Further, a re-peelable adhesive film (refer to Patent Document 3) which adheres to a polystyrene-based adhesive film in which an adhesive film layer and a release sheet are laminated is known. The adhesive force of the material over time, the peeling speed is 2.0 to 4.0 N/25 mm at 5 mm/min, and the peeling speed is 8.0 to 12.0 N/25 mm at 300 mm/min; and a re-peelable aqueous adhesive composition (refer to Patent Document 4) is an aqueous adhesive composition comprising a polymer particle [X] and a hydrazine derivative [Y], wherein the polymer particle [X] is composed of a carbonyl group and a carboxyl group. The average particle diameter of the polymer having an acid value of 3 to 30 is 300 nm or less, and the anthracene derivative [Y] has at least two mercapto groups in the molecule and is formed of the re-peelable aqueous adhesive composition. The film has a glass transition temperature of -25 ° C or less, a gel fraction of 80% by mass or more, and an amount of water extract of 2% by mass or less. These techniques relate to a technique which is excellent in adhesion and which can be easily peeled off from the surface of an adhesive even after being left for a long time after being attached to an adhesive, in particular, the latter relates to a technique using an emulsion type adhesive. .

However, in the above Patent Documents 2 to 4, it is directed to embossing processing or the like. The problem of the case where the rough surface of the uneven surface is adhered to the surface is not described. In fact, if it is adhered to a rough surface such as an embossed surface, the adhesive film is easily peeled off over a long period of time.

Further, Patent Document 5 discloses a method of easily removing an adhesive sheet from a component of an image forming apparatus such as a copying machine or a printer or various electronic devices, and forming a recess in which a groove and a groove intersect in a region where the adhesive sheet is adhered. When recirculating, the adhesive sheet is cut along the groove by means of a tool for decomposition, and the concave portion is used as a mark to peel off the adhesive sheet.

However, in the method of the above-mentioned Patent Document 5, it is necessary to perform the processing for forming the concave portion in the pasted part, and in order to cut the adhesive sheet, if the adhesive sheet having a strong adhesive force is used, it is feared that the base is peeled off. The material will break, or the adhesive will remain on the adhesive, which will result in poor peeling efficiency.

Patent Document 1: Japanese Patent Laid-Open No. Hei 11-158453

Patent Document 2: Japanese Patent Laid-Open Publication No. 2004-315775

Patent Document 3: Japanese Patent Laid-Open Publication No. 2003-183604

Patent Document 4: Japanese Patent Laid-Open Publication No. 2004-277711

Patent Document 5: Japanese Patent Laid-Open Publication No. 2003-308020

Therefore, the present invention provides an adhesive sheet for re-peeling, which is not only a smooth surface of an adhesive, but also has a superior adhesiveness to a rough surface having irregularities such as embossing, and once the attachment of the adhesive sheet is completed, Adhesive film The floating peeling or the like is unlikely to occur for a long period of time, and when the adhesive sheet is peeled off, the re-peelability is excellent, and adhesion of the adhesive due to the adhesive is less likely to occur.

In particular, another object of the present invention is to provide an adhesive sheet for re-peeling by using polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polyphenylene ether, ABS, polycarbonate, and These composite materials are a smooth surface and a rough surface composed of a thermoplastic resin having a main component, and exhibit excellent adhesion and re-peelability, and floating peeling does not occur for a long period of time. Further, another object of the present invention is to provide an adhesive sheet for re-peeling which exhibits superior adhesion and re-peelability to a smooth surface and a rough surface having a surface layer containing an acrylic resin as a main component, and will not be long-term. Floating peeling will occur. Further, another object of the present invention is to provide an adhesive sheet for re-peeling, which solves the above problems, and also exhibits excellent adhesion and re-peelability to the curved surface of each of the adherends, and long-term floating peeling will not occur. occur.

Further, another object of the present invention is to provide an adhesive sheet which does not accumulate between the adhesive sheet and the thermoplastic resin even if gas is released from the thermoplastic resin of the adhered substance.

In order to solve the above problems, as a result of research and development, it has been found that the object of the present invention can be attained by using an adhesive sheet which maintains an adhesive having a moderate balance of elasticity and viscosity. Moreover, it was found that the floating peeling and re-peelability after long-term adhesion can be determined by measuring the loss tangent of the high temperature region in the dynamic viscoelastic spectrum. It is foreseen that the invention can be completed.

That is, the present invention provides an adhesive sheet for re-peeling, which is a re-peelable adhesive sheet having an adhesive layer on at least one side of a substrate, and is characterized by a frequency of 1 Hz, -50 to 150 ° C of the adhesive layer. The loss tangent of the dynamic viscoelastic spectrum is: (a) a low temperature region below -20 ° C with a convex peak at the top; (b) a moderate peak at 10 to 40 ° C with a convex peak below; The loss tangent at 70 ° C is 0.38 ~ 0.57.

The adhesive sheet of the present invention is not only a smooth surface for the adhesive, but also has a superior adhesion to the rough surface having the unevenness or the curved surface, and the floating peeling of the adhesive sheet once the attachment of the adhesive sheet is completed. It does not occur for a long time. In addition, when the adhesive sheet is peeled off, the adhesive is not contaminated by the adhesive or the substrate sheet is broken. Therefore, it is suitable for the following premise: for the purpose of advertising for goods or services, it is set in public places such as packaging containers, vending machines, and automatic ticket machines for cosmetics, cosmetics, beverages, and foods. Equipment, vehicles used in public places such as trams and automobiles, or various types of video information such as texts and patterns for operating instructions or parts replacement procedures for users or repairers, etc., attached to copiers, printers, Various electrical products such as fax machines, personal computers, televisions, air conditioners, refrigerators, and washing machines; most of them are used in various related products such as toner cartridges or ink cartridges; or they constitute automobiles, locomotives, and building materials. Various interior and exterior decorative parts, etc. Peel after peeling.

In particular, since the adhesive sheet of the present invention is made of a composite material of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, modified polyphenylene ether, ABS, polycarbonate, and the like, The smooth surface and the rough surface or the curved surface composed of the thermoplastic resin of the main component have excellent adhesiveness and excellent releasability, and in the case of recycling the electrical product to which the adhesive sheet of the present invention is attached, When the adhesive sheet is peeled off, the adhesive is not contaminated by the adhesive, or the substrate sheet is cut, and the peeling operation is also easy, and it is adhered to the purpose of recycling as a superior adhesive sheet. Components such as electrical products.

Further, in the adhesive sheet of the present invention, even if gas is released from the thermoplastic resin, generation of bubbles between the adhesive sheet and the thermoplastic resin can be prevented. In particular, in various home electric appliances such as copiers, printers, televisions, etc., in the case where the label is attached by hand after completion of the product, it is preferably a thick label, if the adhesive sheet according to the present invention, Since the thick substrate has a strong repulsive force, even if the thickness of the bubble is not easily discharged, it is possible to produce a label having good removability and peeling resistance and which is less likely to accumulate bubbles.

Further, in the case of a smooth surface and a rough surface or a curved surface having a surface layer containing an acrylic resin as a main component, the adhesive sheet of the present invention exhibits excellent adhesion and removability, and is used as a cosmetic or cosmetic product. The tube used for the packaging container or the adhesive sheet for re-peeling adhered to the curved surface of the vending machine is also excellent.

Best form for implementing the invention

Hereinafter, the adhesive sheet for re-peeling of the present invention will be described in more detail based on the structural requirements. Further, in the present specification, the term "(meth)acrylic acid" means acrylic acid or methacrylic acid, and the same is true for derivatives of acrylic acid or methacrylic acid. In addition, the term "circulation" refers to the case where the used product is reused as a raw material of the same kind or another kind of product, and the used product is used in the original state or after being partially trimmed and then used.

(The structure of the adhesive sheet for re-peeling)

The adhesive sheet for re-peeling of the present invention has an adhesive layer laminated on at least one side of the substrate sheet as a basic structure, and is formed in the form of a single-sided adhesive sheet or a double-sided adhesive sheet, and if necessary, the release sheet is placed on the adhesive sheet. On the agent layer. In either case, the adhesive layer laminated on the substrate sheet may be laminated on the entire surface of at least one side of the substrate sheet, or may be a part.

Further, in the case of a single-sided adhesive sheet, printing may be performed on the surface of the adhesive sheet and the substrate sheet on the opposite side. Further, for the purpose of protecting the printed surface or improving the creativity or the appearance, a transparent film or a matte-tone translucent film may be laminated on the printing surface through the adhesive layer or the adhesive layer.

(Regulation method of dynamic viscoelastic properties of the adhesive layer)

The dynamic viscoelastic property of the adhesive layer constituting the adhesive sheet for re-peeling of the present invention is defined by the loss tangent of the dynamic viscoelastic spectrum at a specific frequency and a specific temperature, or according to the loss tangent and the storage elastic modulus. Furthermore, it is specified that the temperature of the dynamic viscoelastic spectrum of a specific frequency is lost or the peak of the tangential wave is lost. In the measurement of dynamic viscoelasticity, a test piece was sandwiched between parallel disks of the measurement site of the same test machine using a viscoelasticity tester (trade name: Ares 2KSTD, manufactured by Rheometrics Co., Ltd.), and measured at a frequency of 1 Hz, from - The storage elastic modulus (G') and the loss elastic modulus (G") from 50 ° C to 150 ° C. The test piece can also be sandwiched between the parallel discs by a thickness of 0.5 to 2.5 mm. In the case where the thickness of the adhesive is adjusted to the above range, the inventors have confirmed that when the thickness of the adhesive is adjusted to the above range, even if the substrate is sandwiched, the adhesive is applied. Dynamic viscoelastic spectroscopy also has no effect.

The adhesive layer constituting the adhesive sheet for re-peeling of the present invention has a loss tangent in the range of -50 ° C to 150 ° C at a frequency of 1 Hz, and has a convex peak in a low temperature region below -20 ° C, from a low temperature region to The medium temperature region is reduced, and it has a convex peak in the middle temperature region of 10 to 40 °C, and rises from the medium temperature region to the high temperature region, and takes a value within a specific range of 70 °C.

By setting the loss tangent to each of the above ranges, an appropriate fluidity is imparted to the adhesive. Specifically, even if the fluidity which is permeable can be found in the minute irregularities on the surface of the adherend, the excessive increase in the adhesive force can be suppressed because it does not excessively flow. Furthermore, the stress applied to the adhesive can be alleviated by the property of the adhesive flowing moderately. As a result, after exposure to time or in a high temperature environment, the adhesive sheet adhered to the adhesive is peeled off, and the substrate to be peeled off is not easily broken and adhered. The agent becomes easy to remain in the adherend. In addition, even when the adhesive sheet attached to the adhesive is exposed over time or in a high temperature environment, floating peeling of the adhesive sheet is less likely to occur. Further, in the case where the adhesive sheet is adhered to the thermoplastic resin, even if gas is released from the thermoplastic resin, bubble accumulation between the adhesive sheet and the thermoplastic resin will not easily occur.

(The loss of the adhesive layer in the high temperature region is tangent)

In the high-temperature field of 50 to 120 ° C, the adhesive layer constituting the adhesive sheet for re-peeling of the present invention has a loss tangent of 0.38 to 0.57 at a frequency of 1 Hz and 70 ° C. The loss tangent at 70 ° C is suitably 0.43 to 0.55, more preferably 0.46 to 0.54. Further, the loss tangent at 50 ° C is suitably 0.38 to 0.53, more preferably 0.40 to 0.51. Further, the loss tangent at 100 ° C is suitably 0.40 to 0.65, more preferably 0.44 to 0.65, and particularly preferably 0.50 to 0.60. Further, the loss tangent at 120 ° C is suitably 0.40 to 0.66, more preferably 0.45 to 0.66. Among them, especially 0.51~0.62 is particularly desirable.

(The loss tangent of the adhesive layer in the medium temperature region)

At a frequency of 1 Hz and 10 ° C to 60 ° C, the loss tangent of the adhesive layer constituting the adhesive sheet for re-peeling of the present invention has a convex peak below. Further, the peak value thereof is preferably 0.35 to 0.51, more preferably 0.4 to 0.51.

(Shows the temperature of the convex peak of the loss tangent curve in the low temperature region)

At a frequency of 1 Hz, the adhesive layer constituting the adhesive sheet for re-peeling of the present invention shows that the temperature of the convex peak of the loss tangent curve is suitably -20 ° C or lower, more preferably -25 ° C or lower, and particularly preferably -30 ° C or lower. ideal. If it is in this range, the adhesive layer will be easy to be embossed on the embossed surface. The flow is sufficient, and as a result, the adhesion to the adherend becomes sufficient, and the floating peeling does not easily occur over time. In addition, when re-peeling is performed, it is not easy to exhibit a feeling of intermittent resistance, or a peeling sound of smashing, and a smooth peeling operation can be performed.

(the peak value of the loss tangent in the low temperature region)

The adhesive layer constituting the adhesive sheet for re-peeling of the present invention preferably has a peak value of loss tangent of 1.3 to 1.0 or less.

(Storage modulus of the adhesive layer)

The adhesive layer constituting the adhesive sheet for re-peeling of the present invention at a frequency of 1 Hz preferably has a storage modulus at 70 ° C of 6.0 × 10 ⁴ to 2.1 × 10 ⁵ (Pa). Further, the storage modulus at 50 ° C is preferably 7.0 × 10 ⁴ to 2.4 × 10 ⁵ (Pa). Further, the storage modulus at 100 ° C is preferably 3.0 × 10 ⁴ to 1.6 × 10 ⁵ (Pa). Further, the storage modulus at 120 ° C is preferably from 2.0 × 10 ⁴ to 1.4 × 10 ⁵ (Pa). Further, the storage modulus at -40 ° C is preferably 5.0 × 10 ⁶ to 5.0 × 10 ⁷ (Pa).

(initial adhesion)

The initial adhesive force Fa of the re-peelable adhesive sheet of the present invention is preferably 3.0 to 9.0 (N/25 mm). Further, the initial adhesion force Fa is preferably 3.0 to 8.0 (N/25 mm), and more preferably 3.0 to 7.0 (N/25 mm). Further, the initial adhesion force Fa is a value defined by a 90-degree peeling adhesion force with respect to a polystyrene sheet having an arithmetic mean height Ra ( ³ ) of 0 to 0.1 μm in accordance with ^a profile curve defined in JIS B 0601 ²⁰⁰¹ . The 90-degree peeling and peeling adhesive force is based on JIS Z 0237, and the pressure-adhesive speed is 5 mm/s, and the number of pressure-adhesive times is one time. The test piece of the test piece is attached to the test piece at a temperature of 23±2° C. and a relative humidity of 50±5. The value measured under the conditions of a tensile speed of 50 mm/min after standing for 24 hours in a gaseous atmosphere of %.

When the initial adhesive force Fa is in the above range, peeling does not easily occur during the adhesion of the adhesive sheet. Further, at the time of peeling off, the adhesive remains on the adherend, or the peeling of the base sheet from the damaged adherend becomes difficult and does not easily occur.

Further, in the adhesive sheet for re-peeling of the present invention, when the initial adhesive force of the polystyrene sheet having a Ra ( ³ ) of 6.8 to 7.2 μm is Fb (N/25 mm), the Fa and the Fb are used. The relationship should be in accordance with formula (1): 0.30 Fb/Fa 1.00 (1)

Fb initial adhesive force with respect to the line Ra ⁽³⁾ is 6.8 ~ 7.2μm polystyrene plates to the value defined by the tear strip 90 Relay sticky, tear strip 90 of bonding force system according to JIS Z 0237, adhesion to the press speed 5mm/s, the number of times of pressure-bonding is back and forth, and the test piece of the test piece is attached, and after being placed in a gas environment of 23±2° C. and relative humidity of 50±5% for 24 hours, the tensile speed is 50 mm/min. The value measured below. Further, the value of Fb/Fa is more preferably in accordance with the following formula (2), and it is preferable to conform to the following formula (3). The relationship between the Fb and the Fa is in this range, which means that the adhesive sheet not only has a smooth surface to the adherend, but also has excellent adhesion even to a rough surface having irregularities. When the value of Fb/Fa is in this range, good adhesion to a rough surface having a concave-convex surface can be obtained, and floating peeling does not easily occur.

0.40 Fb/Fa 1.00 (2)

0.50 Fb/Fa 1.00 (3)

(substrate sheet)

The base material sheet to be used for the adhesive sheet for re-peeling of the present invention is not particularly limited, and examples thereof include a plastic film, a cellulose film, a nonwoven fabric, paper, cloth, or metal foil.

Examples of the plastic film include polyolefin (for example, polypropylene, polyethylene), polyester (for example, polyethylene terephthalate, polyethylene naphthalate), polystyrene, ABS, and polycarbonate. , polyimine film, polyvinyl chloride, nylon, polyvinyl alcohol, etc.; cellulose film can be listed as: cellophane (cellophane), cellulose diacetate, cellulose triacetate and the like. Further, examples of the non-woven fabric include pulp, snail, manila hemp, acrylonitrile, nylon, polyester, and the like; and papers include fine paper, resin coated paper, and the like. In particular, in the case of a single-sided adhesive sheet, in order to prevent the substrate sheet from being cut at the time of re-peeling, it is preferable to use a plastic film as a substrate sheet. Further, as for the above materials, a single component may be used as a main component, and such a composite material may be used. Further, other components may be added in a small amount for the purpose of modifying the substrate sheet. For example, in the case where polystyrene is used for the substrate sheet, it is preferred to use a high impact polystyrene (HIPS) in which polybutadiene is blended in a small amount in the main component to improve flexibility. In the case where light resistance is necessary, it is preferred to use a methyl methacrylate-styrene copolymer resin (MS resin) or an acrylonitrile-styrene-acrylic copolymer resin (ASA resin) or the like. A bulk copolymerized resin or a substrate sheet blended with an acrylic resin.

In the case where the adhesive sheet for re-peeling is used for a label or the like of a recycling member, it is preferable to use the main component of the base material for the re-peelable adhesive sheet as the main component of the recycling member to be adhered. It is particularly preferable that the substrate to be recycled, in particular, the same substrate as the recycling member to be adhered. For example, it is suitable for use in an electrical appliance having a member formed of a thermoplastic resin mainly composed of a composite material containing polypropylene, polyethylene, polystyrene, polyphenylene ether, ABS, polycarbonate, or the like as a main component. In the case of the use of the member, polypropylene, polyethylene, polystyrene, polyphenylene ether, ABS, polycarbonate having the same properties as the main component of the member are used as the main component of the substrate sheet, The compatibility is improved, and if it is not peeled off as necessary, it is possible to directly recycle the material together with the member in the state of adhering the adhesive sheet, and the recycling suitability can be further improved.

For example, in the case where the main component of the member is polypropylene, it is desirable to use polypropylene as a main component of the substrate sheet; in the case where the main component of the member is polyethylene, it is desirable to use polyethylene as a main component of the substrate sheet; In the case where the main component is polystyrene, it is desirable to use polystyrene as a main component of the substrate sheet; in the case where the main component of the member is polyphenylene ether, it is desirable to use polyphenylene ether as a main component of the substrate sheet; In the case where the main component is ABS, it is desirable to use ABS as a main component of the substrate sheet; in the case where the main component of the member is polycarbonate, it is desirable to use polycarbonate as a main component of the substrate sheet; the main component of the member is In the case of a composite of polycarbonate and ABS, it is desirable to use polycarbonate, ABS, or A substrate sheet composed of a thermoplastic resin in which a composite material of polycarbonate and ABS is a main component.

Further, in order to suppress the accumulation of bubbles between the adhesive sheet and the thermoplastic resin due to the release of the gas from the thermoplastic resin, it is desirable to use a substrate excellent in gas permeability. For example, polypropylene, polyethylene, polystyrene, etc. are mentioned.

In the case of the HIPS substrate sheet, the tensile breaking strength MD is preferably 20 MPa or more, and TD is preferably 15 MPa or more. When it is in the above range, it is possible to peel off the substrate without being cut and peeling off. Furthermore, the tensile elongation at break is preferably 30 to 60% for both MD and TD. In the above range, in order to impart moderate rigidity and flexibility, the film does not easily break, and it is also difficult to stretch, and the removability is further improved.

The tensile strength and tensile elongation at break of the substrate sheet are in a gas atmosphere at a temperature of 23±2° C. and a relative humidity of 50±5%, and the substrate sheet is stretched at a tensile speed of 200 mm/min. It is specified according to the strength and elongation at the time of fracture of the substrate. In the case of the regulation, it is defined in accordance with the flow direction (MD) and the width direction (TD) of the substrate sheet. At the time of the measurement, the substrate sheet is preferably measured separately, but the inventors have confirmed that even if the adhesive layer is laminated, the tensile strength at break and the tensile elongation at break are not affected.

In the case of coloring the substrate, a coloring agent (masterbatch) in which an inorganic pigment such as titanium oxide is stirred by using the same resin as the substrate sheet can be added. Relative to 100 parts by mass of the resin to be a film substrate is added in an amount of 5 to 20 parts by mass of a master batch containing 50% by mass of titanium oxide, more preferably 10 to 15 parts by mass. When it is 5 parts by mass or more, the concealing property of the substrate becomes good, and when it is 20 parts by mass or less, the base material due to the master batch is broken, or foreign matter such as fish eyes becomes less likely to occur. .

The thickness of the substrate sheets is preferably determined depending on the purpose or condition of use, and the case of the single-sided adhesive sheet is preferably 15 to 250 μm, more preferably 15 to 250 μm, depending on the workability or anti-repellency of the copper-clad laminate. 25 to 115 μm, more preferably 50 to 95 μm. On the other hand, in the case of a double-sided adhesive sheet, it is preferably 30 to 200 μm, more preferably 50 to 150 μm, and further, the paper weight in gsm is suitably 10 to 100 g/m ² , more preferably 15 to 50 g. /m ² .

(surface treatment of the substrate sheet)

Further, based on the purpose of improving the adhesion to the layer (adhesive layer or printed layer) laminated on the substrate sheet, corona treatment and plasma treatment may be applied to one or both sides of the substrate sheet. Roughening treatment, flame treatment, chromic acid treatment, hot air treatment, ozone irradiation treatment, ultraviolet irradiation treatment or coating of a thickening paint. In particular, the surface of the substrate on the side of the adhesive layer is subjected to a corona treatment or an adhesion-promoting treatment, so that the adhesive layer is not easily peeled off from the surface of the substrate, and the adhesive sheet for re-peeling of the present invention is adhered to the adhesive. The removability after the article is improved, and the adhesive layer can be further prevented from remaining on the adherend.

An anchor coat layer is formed by applying an adhesion-promoting agent comprising a pigment for adsorbing ink, a binder resin, and a dispersant to a substrate sheet. As the pigment, conventional calcium carbonate, titanium oxide, synthetic cerium oxide or the like can be used. Among them, when the base material sheet is wound into a cylindrical shape, it is also considered to prevent agglomeration of the back surface of the base material sheet and the adhesion-promoting coating layer, and it is preferable to synthesize cerium oxide which allows the particle diameter to be freely changed. As the binder resin, an acrylic resin, a urethane resin, a polyvinyl alcohol resin, a vinyl chloride-vinyl acetate copolymer resin, a polyester resin or the like can be used. Among them, an acrylic resin used for a binder resin of a large amount of ultraviolet curable ink (UV ink) is preferred. The dispersing agent is not particularly limited, and it is applied to a substrate sheet such as polystyrene or ABS which is easily swollen or dissolved by a solvent, and a dispersing agent which does not dissolve the substrate sheet is preferably used, and is preferably isopropanol or ethanol. The main thing is alcohol. The blending of the tackifying agent is preferably in the range of 5 to 10 parts by mass of the pigment, 20 to 30 parts by mass of the binder resin, and 60 to 70 parts by mass of the dispersing agent. The coating amount of the coating agent is suitably from 0.5 to 4.0 g/m ² , more preferably from 1.0 to 2.0 g/m ² .

As the coating method of the adhesion-promoting agent to the base material sheet, a gravure coater, a knife coater, a roll coater or the like can be used. Among them, a gravure coater is preferred.

(modulation of adhesive)

As the adhesive for the adhesive sheet for re-peeling of the present invention, a conventional acrylic, rubber-based, vinyl ether-based or decane-based adhesive can be used. Among these adhesives, an acrylic adhesive is preferred. In particular, the monomer component is preferably an acrylic copolymer containing a (meth) acrylate having a C 1-14 alkyl group. For example: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, (meth)acrylic acid Propyl ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, (methyl) ) isooctyl acrylate, 2-ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-decyl (meth)acrylate, (methyl) The lauryl acrylate or the like can be used singly or in combination of two or more. Preferably, it is preferably n-butyl acrylate, 2-ethylhexyl acrylate, or a monomer used as a main component, and the amount thereof is preferably 50 to 99% by mass, more preferably 95%, of the adhesive composition. ~99% by mass. Further, the mass ratio of (n-butyl acrylate/2-ethylhexyl acrylate) is suitably 70/30 to 0/100, more preferably 45/55 to 5/95, more preferably 35/. 65~15/85. The present inventors have found that the main single system can easily control the loss tangent of the low temperature region in the dynamic viscoelastic spectrum by setting the above-mentioned type and amount, and it is easy to control the peak value of the convex wave within the range of the purpose.

Further, a vinyl monomer having a functional group such as a hydroxyl group, a carboxyl group or an amine group in the side chain is preferably added in an amount of from 0.01 to 15% by mass. For example: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, acrylic acid, methacrylic acid, maleic acid, horse Anhydride, itaconic acid, crotonic acid, fumaric acid, acrylic acid maleic anhydride carboxypropyl ester, dimethylamine ethyl acrylamide, N-vinyl pyrrolidone, acrylonitrile, N-vinyl caprolactam, propylene Hydrazine, styrene, ethyl acetate, N-methylol acrylamide, glycidyl methacrylate, etc., and these vinyl monomers can be used singly or in combination of two or more. Among them, it is more suitable to use The vinyl monomer having a carboxyl group is more preferably acrylic acid, methacrylic acid or the like. Further, the amount thereof is preferably from 0.5 to 4.0% by mass. In particular, in order to improve the adhesion between the re-peelability and the curved surface, it is preferred to use acrylic acid and methacrylic acid in combination. In particular, the total amount of acrylic acid and methacrylic acid is used in an amount of 1.5 to 2.5% by mass in the adhesive composition, and the ratio of methacrylic acid to acrylic acid is suitably 0.5 to 2.0, more preferably 1.0 to 1.5. The present inventors have found that a single system containing a carboxyl group can easily control the loss tangent value in the dynamic viscoelastic spectrum within the intended range by setting the above-mentioned type and amount, and the releasability is further improved.

The acrylic copolymer can be obtained by copolymerization according to a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, an ultraviolet irradiation method, or an electron beam irradiation method. Among them, an emulsion polymerization method is preferred.

In order to further improve the cohesive force of the adhesive, and to improve the adhesion or re-peelability, it is preferred to add a crosslinking agent. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a chelate crosslinking agent, and an oxazoline crosslinking agent. Among them, an oxazoline crosslinking agent is preferred. In particular, when an oxazoline-based crosslinking agent is used, the removability is improved by improving the adhesion to the substrate sheet. Further, as the monomer which reacts with the oxazoline group, acrylic acid and methacrylic acid are preferably used, and the ratio of the number of functional groups of the oxazoline group to the carboxyl group is 0.05 to 0.25. Further, in order to improve the adhesion, it is also possible to use a conventionally bonded resin.

The loss of 50 ° C ~ 120 ° C in the dynamic viscoelastic spectrum of the present invention is positive The cutting can be adjusted according to the amount of crosslinking agent added and Tg. In order to increase the loss tangentially, it is achieved by reducing the amount of crosslinking agent added and using a crosslinking agent having a low Tg; if it is to be reduced, by increasing the amount of crosslinking agent added, using a high Tg It is achieved by a crosslinking agent.

Further, as the adhesive, for example, a conventional additive such as a light stabilizer, a UV absorber, a plasticizer, a softener, a filler, a pigment, or a flame retardant can be added. Examples of the light stability include chain inhibitors, hydrogen peroxide decomposers, metal inert agents, and ultraviolet absorbers. By using such an additive, the above-described yellowing resistance can be improved.

(type of adhesive)

The type of the adhesive can be an emulsion type, a solvent type, a solventless type or the like, and the adhesive for the adhesive sheet for re-peeling of the present invention is preferably an emulsion type adhesive. The present inventors have found that since the emulsion type adhesive does not use a solvent, it is advantageous in terms of the environmental surface, and it is also easy to control the loss in the high temperature field in the dynamic viscoelastic spectrum within the range of the purpose.

(Modulation of acrylic emulsion type adhesive)

The method for producing the acrylic emulsion type adhesive of the present invention is not particularly limited, and a conventional method can be used. The polymerization method can employ batch polymerization, continuous dropping polymerization, separate dropping polymerization, etc., for example, a polymerization temperature of about 20 to 100 °C.

In order to obtain the emulsion polymerization of the emulsion type adhesive, in order to ensure the polymerization stability, an anionic or nonionic emulsification can be used in an appropriate amount. Agent. In particular, the emulsifier is not particularly limited, and a conventional emulsifier can be used. Examples of the anionic emulsifier include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, and the like. Examples of the nonionic emulsifier include polyethylene oxide alkyl ether and polyethylene oxide alkylphenyl ether. The above emulsifiers can be used singly or in combination of several kinds. Further, for example, any of an anionic or nonionic system may be, for example, a radical polymerizable emulsifier having a propylene group introduced therein.

In order to obtain an emulsion polymerization of an emulsion type adhesive, a polymerization initiator can be used. The polymerization initiator is not particularly limited, and a conventional polymerization initiator can be used. Specifically, a salt of dihydrochloride-2,2'-azobis(2-methyldiethyl ketone oxime) and 4,4'-azobis(4-cyano)pentanoic acid can be used. An azo system such as dihydrochlorinated-2,2'-azobis(2-amidinopropane); a peroxide such as benzamidine peroxide, t-butyl hydroperoxide or hydrogen peroxide; A redox initiator composed of a combination of persulfate and sodium hydrogen sulfite or a combination of a peroxide and sodium ascorbate. In general, it is preferred that the initiators are added to the various stages of the emulsion polymerization to allow the polymerization to proceed.

Among them, it is desirable to use an initiator which generates a carbon radical, and an azo initiator is preferably used. The carbon radicals lack the dehydrogenation ability, and the grafting of the polymer becomes difficult to proceed, and the linear polymer can be easily obtained. As a result, the present inventors have found that it is easy to converge the loss in the high-temperature field in the dynamic viscoelastic spectrum and the convex wave below the loss in the middle temperature region. The peak value is within the range of the purpose.

In order to obtain an emulsion type adhesive, a reducing agent can be used. Examples of the reducing agent include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, glucose, and formaldehyde sulfite metal salts; and reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium metabisulfite, and sodium metabisulfite.

In order to obtain an emulsion polymerization of an emulsion type adhesive, a chain transfer agent can be used in order to adjust the degree of polymerization. Examples of such a chain transfer agent include dodecylphosphonium, butylphosphonium, 2-mercaptoethanol, and trichlorobromomethane. At least one selected from the group consisting of such chain transfer agents can be used. In the case where the acrylic monomer is used as a monomer component, 0.01 to 0.2 parts by mass of dodecylphosphonium is preferably blended with respect to 100 parts by mass of the acrylic monomer, and more preferably 0.01 to 0.04 by mass is blended. It is preferred to blend 0.015 to 0.025 parts by mass.

In order to obtain an emulsion polymerization of an emulsion type adhesive, after emulsion polymerization, a neutralization treatment is usually carried out by using a neutralizing agent such as ammonia to adjust to a predetermined pH, and a stable emulsion type adhesive can be obtained, wherein It should be in the range of pH 8.5 to 9.5.

(thickness of adhesive layer)

In the case of the single-sided adhesive sheet, the thickness of the adhesive layer used in the adhesive sheet for re-peeling of the present invention is preferably from 3 to 200 μm, more preferably from 5 to 50 μm, particularly preferably from 10 to 25 μm. Further, in the case of the double-sided adhesive sheet, it is preferably 30 to 300 μm, more preferably 50 to 200 μm. Under the above lower limit value, the adhesion of the obtained adhesive sheet for re-peeling will be If it becomes insufficient and exceeds the upper limit value, the overflow of the adhesive will easily occur during printing or die cutting.

(peeling sheet)

In the adhesive sheet for re-peeling of the present invention, a release sheet is provided on the adhesive layer as necessary. Examples of the release sheet include papers such as kraft paper, cellophane, and fine paper; on the paper, a synthetic resin such as polyvinyl alcohol or a clay paper is coated on one side or both sides; or on such paper, single or double A paper such as an area-layer polyethylene resin; or a plastic film such as polyethylene terephthalate, polyethylene naphthalate, or polypropylene, which is coated on one or both sides by fluororesin or enamel resin. The substance of the agent. The thickness of the release sheet is not particularly limited, but is generally in the range of 20 to 30 μm.

(Preparation method for peeling adhesive sheets)

The method for producing the adhesive sheet for re-peeling of the present invention is not particularly limited, and can be produced according to a conventional production method. For example, in the case of a single-sided adhesive sheet, it can be obtained by coating, drying, thermally hardening an adhesive solution on a release sheet, or after adhering to an electromagnetic radiation effect or the like, and adhering the adhesive sheet. Further, in the case of the double-sided adhesive sheet, it can be obtained by applying an adhesive solution onto the release sheet, and attaching the treated release sheet to both sides of the substrate sheet. Alternatively, it can be obtained by applying the treatment to adhere the release sheet after directly applying the adhesive solution to the substrate sheet. Further, in order to improve the adhesion between the base sheet and the adhesive layer, it is also possible to bond at a high temperature of 40 to 100 ° C or the like. The adhesive sheet for re-peeling of the present invention is selected by a process, It can be manufactured in a roll shape, a belt shape or a sheet shape.

(use case)

The shape or size of the adhesive sheet for re-peeling produced in this manner is not particularly limited, and can be appropriately set in accordance with the use or purpose, and is used after being cut from a roll, a strip or a sheet of adhesive sheet. . In particular, in the case of a single-sided adhesive sheet, before the shape or size required to be cut, or after the dicing, on the surface side of the adhesive layer on which the base material sheet is not provided, the product name, service, advertisement content, etc. are displayed. Printing of various patterns or texts. The printing method is not particularly limited, and a lithographic printing method such as an offset printing method, a gravure printing method such as a gravure printing method, a flexographic printing method such as a flexographic printing method, or a stencil printing method such as a screen printing method can be used. Various printing methods.

Further, for the purpose of protecting the printed surface or improving the creativity or the appearance, a transparent film or a matte tone translucent film may be laminated on the printing surface through the adhesive layer or the adhesive layer. A sheet, sticker, or label that has been printed and cut into various shapes and sizes of adhesive sheets for re-peeling is used as a store for cosmetics, cosmetics, household goods, pharmaceuticals, foods, drinks, electrochemical products, or stationery. Retail merchandise, etc., are used for promotional materials such as eye-catching labels for general consumer promotions. In addition, it is attached to a vehicle such as a train, a car, or a taxi, a device such as a vending machine such as a cigarette or a beverage, an automatic ticket machine, or a window, and the like, and is used as a promotion for advertising products or services to consumers. Used by materials. Furthermore, it sticks to copiers, printers, fax machines, personal computers, Various electrical products such as televisions, air conditioners, refrigerators, and washing machines; various related products that are mostly used and reused such as toner cartridges or ink cartridges; or various interior and exterior decorative parts that constitute automobiles, locomotives, and building materials. Indicates the product name of the product and the part, or various types of image information such as the text and illustration of the operation manual or parts exchange program for the user or the repairer. For example, the order address of the consumable or the contact address of the repair is entered. Alternatively, it can be constructed by recording the established information on the surface of the adhesive sheet.

The adhesive sheet for re-peeling of the present invention is used in the above-mentioned use, and in order to exhibit good adhesion to the adhesive, it is not only a smooth surface of various electrical products or the like, even if it is adhered to a rough surface having irregularities, The floating peeling may occur, and the adhesive may remain on the surface of the adhesive even if the adhesive sheet for re-peeling of the present invention is peeled off from the adhesive which has been adhered for a long period of time due to the superior re-peelability. It will not be cut off. That is, the adhesive sheet for re-peeling of the present embodiment is suitable for producing sheets, stickers or labels used for publicity, advertising, and information display.

More specifically, the label for using the adhesive sheet or the adhesive sheet of the present invention includes the step of peeling off the adhesive sheet or the adhesive label when recycling, and is suitable for adhering to have an arithmetic average height Ra (by the surface contour curve) ³ ) Thermoplastic resin with 0~10.0μm polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polyphenylene ether, ABS, polycarbonate and these composite materials as main components The use of the component of the formed electrical product. Among them, it is suitable for sticking to a member formed of a thermoplastic resin mainly composed of a polystyrene, a polyphenylene ether, an ABS, a polycarbonate, and the like as a main component (the adhesive strength is likely to become high after long-term attachment). Use. In addition, by using a base material sheet containing a thermoplastic resin of the same type as the main component of the member as a main component, the compatibility with the member is improved, and if necessary, the sheet is not peeled off, and the adhesive sheet is directly adhered. It is also possible to carry out material recycling for each member, and it is possible to further improve the recycling suitability. Further, as the adhesive sheet of the present invention or the label using the adhesive sheet, the material used for the member for recycling is not only a resin product as described above but also a member composed of an inorganic material such as glass or metal. . Further, the adhesive sheet of the present invention is suitable for application to a member having a rougher surface, and is more effective after being applied to the above member having a Ra ( ³ ) of 3.0 to 10.0 μm, in particular, the adhesion to Ra ( ³ ) is 5.0. It is particularly effective to use the above components of ~10.0 μm.

Further, even in the case where the gas is released from the above-mentioned thermoplastic resin in a state where it is easy to occur (for example, immediately after molding or in a high-temperature environment), adhesion to the adhesive sheet of the present invention can be suppressed between the adhesive sheet and the thermoplastic resin. The accumulation of bubbles occurs.

Further, it is applied to a curved surface having a surface layer containing an acrylic resin or a thermoplastic resin as a main component, and is applied to a surface which must be attached and peeled off after a certain period of time. In particular, it is suitable for labeling as a packaging container (a tube container used for cosmetics or cosmetics) which is adhered to a surface layer having an acrylic resin as a main component, polypropylene, polyethylene, and a composite material thereof. Use for materials. Or, suitable for pasting It is formed by coating a metal coated with an acrylic resin as a main component or a plastic containing polymethyl methacrylate or the above thermoplastic resin as a main component, and a curved convex portion having a curvature radius of 200 mm or less ( The bending part of the vending machine and the corner part of the electrical appliance). Further, the adhesive sheet of the present invention is suitable for application to a member having a small radius of curvature of a relatively curved portion, and is more effective after being applied to the member having a radius of curvature of 50 mm or less. In particular, it is particularly effective to adhere to the member having a radius of curvature of 10 mm or less.

[Examples]

Next, the embodiment and the comparative example of the present invention will be described in detail. In the following examples and comparative examples, "parts" means parts by mass.

(Example 1)

In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen inlet tube, a thermometer, and a titration funnel, 3 parts of Latemul S-180 (manufactured by Kao Corporation: 50% active ingredient) and 40 parts of deionized water were added, and nitrogen gas was injected thereto. Warm up to 60 ° C on one side. While stirring, an aqueous solution in which 0.05 part of dihydrochloride-2,2'-azobis(2-methylpropionamidine) was dissolved in 4.95 parts of deionized water was added, followed by being used as an acrylic monomer. 72.3 parts of 2-ethylhexyl acrylate, 25 parts of butyl acrylate, 0.5 parts of methyl methacrylate, 1.0 part of acrylic acid, 1.2 parts of methacrylic acid, and 0.02 parts of dodecyl fluorene as a chain transfer agent To the monomer mixture, a part (4 parts) of the monomer pre-emulsion which has been emulsified by adding the addition of Latemul S-180 (2 parts) and 20 parts of deionized water, and maintaining the temperature in the reaction vessel at 60 ° C, Give Gather for 60 minutes. Next, while maintaining the temperature in the reaction vessel at 60 ° C, the remaining monomer pre-emulsion and the dihydrochloride -2,2'-azobis(2-methylpropionamidine) were respectively used using respective titration hoppers. 0.2 part of an aqueous solution dissolved in 19.8 parts of deionized water was allowed to be polymerized while dropping the temperature in the reaction vessel at 60 ° C for 240 minutes. After completion of the dropwise addition, the mixture was stirred at the same temperature for 180 minutes, and after cooling the contents, the pH was adjusted to 8.5, and the aqueous ammonia (active ingredient: 10%) was adjusted. To 100 parts of the obtained aqueous dispersion, 0.8 parts of Surflynol 420 (manufactured by Air Products Japan Co., Ltd.) as a flattening agent was added. Further, an oxazoline-based crosslinking agent Epocross K-2020E (manufactured by Nippon Shokubai Co., Ltd.) as a crosslinking agent is further added to make a molar group of a oxazoline group and a carboxyl group-containing monomer (acrylic acid and methacrylic acid). After the addition was carried out in a manner of 0.15 times, the emulsion type adhesive was prepared by filtration using a 100 mesh metal mesh.

Next, the polydecane compound was applied onto a release sheet of polyethylene laminated paper ("OKB-150NC" manufactured by Oji Paper Co., Ltd.), and an adhesive was applied thereto, followed by drying at 80 ° C for 90 seconds to obtain a dried thickness of 20 μm. Adhesive layer. Next, Yupo SGS80 (manufactured by Yupo Corporation) was attached to the adhesive layer, and after standing for 3 days in a gas atmosphere of 40 ° C, an adhesive sheet (1) for re-peeling was obtained.

(Example 2) (modulation of adhesion promoter)

In the ink-receiving resin, 50 parts of an acrylic resin solution ("Thermolac FE-32-3" manufactured by Amika Chemical Co., Ltd., solid content: 45%) was added as a thinner. 45 parts of a solvent mixture of ethanol and isopropyl alcohol in a 4:1 mixed solvent, and 5 parts of synthetic antimony oxide ("Sylysia 350" manufactured by Fuji Silica Chemical Co., Ltd.) as an anti-caking agent, and a total of 100 parts of the blending liquid was adjusted. The blending solution was dispersed for 20 minutes using a paint conditioner to obtain an adhesion-promoting agent having a solid content of 27.5%.

(film formation of polystyrene film substrate sheet)

A batch of 15 parts of a master batch containing 50% of titanium oxide was added to 100 parts of a HIPS resin obtained by graft-polymerizing 60 parts of styrene with 40 parts of SBR, respectively, at 200 ° C. The T-die extrusion film forming machine was used for melt extrusion to obtain an unstretched film having a thickness of 100 μm. Next, corona treatment was performed so as to have a wet index of 50 mN/m on both sides of the film. Further, on the surface of the build-up adhesion-promoting coating layer, a coating agent was applied by using a gravure coater, and a polystyrene film substrate sheet was prepared by providing an adhesion-promoting coating layer having a coating amount of 1.5 g/m ² .

The adhesive sheet (2) was obtained in the same manner as in Example 1 except that the polystyrene film was used as the substrate sheet.

After the evaluation of the obtained adhesive sheet (2), 20% of the adhesive sheet (2) was added to the HIPS resin pellet (HIPS resin manufactured by Toyo Styrene Co., Ltd.), uniformly mixed, and then extruded at 220 ° C. Re-granulation once. Similarly, in the case where the adhesive sheet was not added, the pellet was also re-granulated once (blank). Next, the regranulated pellets were molded at a mold temperature of 50 ° C and a melting temperature of 220 ° C to form test pieces. According to JIS K 7113, the measurement is carried out in a gas atmosphere at a temperature of 23 ° C and a relative humidity of 50%. Tensile strength and tensile elongation at break. (Tensile speed: 50 mm/min, shape of test piece: test piece No. 1). The measuring machine used the Tensilon universal testing machine "RTA-100" manufactured by A and D, and set the distance between the marking lines of the test piece to 50 mm, the distance between the grippers to 115 mm, the length of the grip portion to 30 mm, and the width of the parallel portion to 10 mm. The thickness is 5mm. Similarly, in place of the PS resin pellet, 20% of the adhesive sheet was added to a PPE resin pellet ("Noryl" manufactured by GE Plastics Co., Ltd.) modified with a styrene resin, and it was similarly at 240 ° C. Regranulation and sample preparation were carried out. The adhesive sheet (2) was integrated with the recirculating member, and the change in the tensile physical properties in the case of recycling was evaluated, and the case where it was added to any of the resins, tensile breaking strength was confirmed as compared with the case where the adhesive sheet was not added. The reduction is 9%, the tensile elongation at break is 13%, and any characteristic change has a suitable recycling characteristic of ±20% or less.

(Example 3)

An adhesive sheet (3) was obtained in the same manner as in Example 2 except that a thickness of 65 μm of the polystyrene base sheet was used for the base sheet. The obtained adhesive sheet (3) was also subjected to the same manner as in Example 2, and 20% of the adhesive sheet (3) was added to the HIPS resin pellets and the modified PPE resin pellets to evaluate the tensile property change in the case of recycling. It was confirmed that the addition to any of the resins was such that the reduction in tensile strength at break was 12%, the increase in tensile elongation at break was 15%, and any change in characteristics had a suitable recycling property of ±20% or less. .

(Example 4)

In addition to the adjustment of the emulsion type adhesive, the crosslinking agent used in Example 1 was used as an oxazoline crosslinking agent Epocross K-2010 (manufactured by Nippon Shokubai Co., Ltd.) to give an oxazoline group and a carboxyl group. The adhesive sheet (4) was obtained in the same manner as in Example 1 except that the ear ratio was 0.03 times.

(Example 5)

The adhesive sheet was obtained in the same manner as in Example 1 except that the molar ratio of the oxazoline group and the carboxyl group disclosed in Example 1 was 0.1 times in the adjustment of the emulsion type adhesive. (5).

(Example 6)

The adhesive sheet was obtained in the same manner as in Example 1 except that the molar ratio of the oxazoline group and the carboxyl group disclosed in Example 1 was 0.25 times in the adjustment of the emulsion type adhesive. (6).

(Example 7)

In addition to the adjustment of the emulsion type adhesive, the blending of 1.0 part of acrylic acid of Example 1 and 1.2 parts of methacrylic acid was used in combination with 2.2 parts of acrylic acid alone, and the same manner as in Example 1 was carried out. An adhesive sheet (7) is obtained.

(Example 8)

In the same manner as in Example 1, except that 1.0 part of acrylic acid of Example 1 and 1.2 parts of methacrylic acid were used in combination and changed to 2.2 parts of methacrylic acid alone, in addition to the adjustment of the emulsion type adhesive. Then, an adhesive sheet (8) is obtained.

(Comparative Example 1)

In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen inlet tube, a thermometer, and a titration funnel, 79 parts of 2-ethylhexyl acrylate, 20 parts of methyl methacrylate, 0.8 parts of acrylic acid, and 2-hydroxy acrylate were added. 0.2 part of ethyl ester and 0.2 part of azobisisosuccinonitrile as a polymerization catalyst were dissolved in 100 parts of ethyl acetate, and polymerized at 80 ° C for 8 hours, and then cooled to form a solid content of 30%. Thereafter, an acrylic copolymer solution was obtained. Then, 0.7 parts of an isocyanate-based crosslinking agent ("Burnock NC-40" manufactured by Dainippon Ink and Chemicals, Inc.) was added to 100 parts of the acrylic copolymer solution, and the mixture was stirred for 15 minutes to prepare a solvent-based adhesive. The adhesive sheet (H1) was obtained in the same manner as in Example 1 except that the preparation of the adhesive was carried out.

(Comparative Example 2)

In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen inlet tube, a thermometer, and a titration funnel, 90.3 parts of butyl acrylate, 8 parts of vinyl acetate, 1.5 parts of acrylic acid, and 0.2 parts of 2-hydroxyethyl acrylate were added. 0.2 part of azobisisosuccinonitrile of a polymerization catalyst was dissolved in 100 parts of ethyl acetate, and polymerization was carried out at 80 ° C for 8 hours to obtain an acrylic copolymer solution. Then, 10 parts of the unsaturated rosin ester ("Super Ester A100" by Arakawa Chemical Co., Ltd.) and 10 parts of the polymerized rosin pentaerythritol ester ("Pensel D135" manufactured by Arakawa Chemical Co., Ltd.) were added to 100 parts of the solid content of the acrylic copolymer solution. 10 parts of ethyl acetate was added in such a manner that the solid content became 45%, and the mixture was uniformly mixed to obtain an acrylic copolymer mixed solution. Later, phase To 100 parts of the acrylic copolymer solution, 1.2 parts of an isocyanate-based crosslinking agent ("Burnock NC-40" manufactured by Dainippon Ink and Chemicals, Inc.) was added, and the solvent-type adhesive was prepared by stirring for 15 minutes. The adhesive sheet (H2) was obtained in the same manner as in Example 1 except that the preparation of the adhesive was carried out.

(Reference example 1)

In a reaction vessel equipped with a stirrer, a reflux cooling tube, a nitrogen gas introduction tube, a thermometer, and a titration funnel, 40 parts of deionized water was added, and while nitrogen gas was injected, the temperature was raised to 75 °C. 0.03 parts of a third butyl hydroperoxide and 0.015 parts of L-ascorbic acid were added under stirring, followed by 75 parts of 2-ethylhexyl acrylate as an acrylic monomer, 19 parts of butyl acrylate, and methyl group. Addition of Latemul E-118B (Kao Corporation) to a monomer mixture consisting of 2 parts of methyl acrylate, 1 part of vinyl acetate, 1.5 parts of acrylic acid, 1.5 parts of methacrylic acid, and 0.02 parts of dodecyl hydrazine as a chain transfer agent A portion (4 parts) of a monomer pre-emulsion obtained by emulsifying 15 parts of deionized water and 15 parts of deionized water, and the temperature in the reaction vessel was maintained at 75 ° C, and polymerization was carried out for 60 minutes. Next, while maintaining the temperature in the reaction vessel at 75 ° C, the remaining monomer pre-emulsion and the aqueous solution of the third butyl hydroperoxide (active ingredient 1%) were respectively 15 parts and L using the respective titration hoppers. - 15 parts of an aqueous solution of ascorbic acid (0.5% of active ingredient), and the temperature in the reaction vessel was maintained at 75 ° C while being dropwise added for 240 minutes to carry out polymerization. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 180 minutes, and after cooling the contents, the pH was adjusted to 8.5 to utilize ammonia water (effective 10% of the ingredients are adjusted. To 100 parts of the obtained aqueous dispersion, 0.8 parts of Surflynol 420 (manufactured by Air Products Japan Co., Ltd.) as a flattening agent was added. Further, an oxazoline-based crosslinking agent Epocross K-2020E (manufactured by Nippon Shokubai Co., Ltd.) as a crosslinking agent is further added to make a molar group of a oxazoline group and a carboxyl group-containing monomer (acrylic acid and methacrylic acid). After the addition was carried out in a manner of 0.2 times, the emulsion type adhesive was prepared by filtration using a 100 mesh metal mesh.

The adhesive sheet (H3) for re-peeling was obtained in the same manner as in Example 1 except that the emulsion type adhesive was prepared.

(Example 9) (filming of ABS substrate sheet)

20 parts of the master batch containing 50% of titanium oxide was added to 100 parts of the ABS resin, and the film was formed by a calendering method to obtain an unstretched film having a thickness of 80 μm. Next, corona treatment was performed so as to have a wetness index of 46 mN/m on both sides of the film. Further, an adhesion-promoting coating agent used in Example 2 was applied onto the film by using a gravure coater, and an adhesion-promoting coating layer having a coating amount of 1.5 g/m ^{2 was} set to prepare an ABS film substrate sheet.

The adhesive sheet (9) for re-peeling was obtained in the same manner as in Example 1 except that the ABS film was used for the substrate sheet.

After the evaluation of the obtained adhesive sheet (9), 1% of the adhesive sheet (9) was uniformly mixed with ABS resin pellets (refractory ABS resin manufactured by UMG ABS Co., Ltd.), and then the extrusion temperature was 240 ° C. Re-granulation once. Similarly, in the case where the adhesive sheet is not added, the pellet is also re-granulated once. (blank). Next, the regranulated pellets were formed into a test piece at a mold temperature of 50 ° C at a melting temperature of 200 ° C. The tensile breaking strength and tensile elongation at break were measured in a gas atmosphere at a temperature of 23 ° C and a relative humidity of 50% in accordance with JIS K 7113. (Tensile speed: 50 mm/min, shape of test piece: test piece No. 1). The measuring machine used the Tensilon universal testing machine "RTA-100" manufactured by A and D, and set the distance between the marking lines of the test piece to 50 mm, the distance between the grippers to 115 mm, the length of the grip portion to 30 mm, and the width of the parallel portion to 10 mm. The thickness is 5mm. The adhesive sheet (9) was integrated with the recirculating member, and the change in the tensile physical properties in the case of recycling was evaluated, and the case where it was added to any of the resins, tensile breaking strength was confirmed as compared with the case where the adhesive sheet was not added. The decrease is 0%, the tensile elongation at break is 0%, and any characteristic change has a suitable recycling characteristic of ±20% or less.

(Embodiment 10)

An adhesive sheet (10) was obtained in the same manner as in Example 4 except that the substrate sheet was a 120 μm thick BS substrate sheet. The obtained adhesive sheet (10) was also subjected to the same manner as in Example 4, and after adding 1% of the adhesive sheet (10) to the ABS resin pellets, the change in the tensile physical properties in the case of recycling was evaluated, and it was confirmed that it was added thereto. In a case of a resin, the reduction in tensile breaking strength is 1%, the increase in tensile elongation at break is 0%, and any characteristic change has a suitable recycling property of ±20% or less.

(Example 11) (film formation of polycarbonate substrate sheet)

A blend of 20 parts of a master batch containing 50% of titanium oxide added to 100 parts of a polycarbonate resin was formed into a film by a calendering method to obtain an unstretched film having a thickness of 100 μm. Next, corona treatment was performed so as to have a wet index of 50 mN/m on both sides of the film. Further, an adhesion-promoting coating agent used in Example 2 was applied onto the film by using a gravure coater, and an adhesion-promoting coating layer having a coating amount of 1.5 g/m ^{2 was} set to prepare a polycarbonate film substrate sheet.

An adhesive sheet (11) was obtained in the same manner as in Example 1 except that the polycarbonate film was used as the substrate sheet.

After the evaluation of the obtained adhesive sheet (11), a 2.5% adhesive sheet (11) was added to an alloy resin pellet of polycarbonate and HIPS (a flame retardant polycarbonate-HIPS alloy resin manufactured by Daicel Polymer Co., Ltd.). After uniformly mixing, the pellet was pelletized once at an extrusion temperature of 240 °C. Similarly, in the case where the adhesive sheet was not added, the pellet was also re-granulated once (blank). Next, the pellets which were pelletized were formed into a test piece at a mold temperature of 50 ° C and a melting temperature of 220 ° C. The tensile breaking strength and tensile elongation at break were measured in a gas atmosphere at a temperature of 23 ° C and a relative humidity of 50% in accordance with JIS K 7113. (Tensile speed: 50 mm/min, shape of test piece: test piece No. 1). The measuring machine used the Tensilon universal testing machine "RTA-100" manufactured by A and D, and set the distance between the marking lines of the test piece to 50 mm, the distance between the grippers to 115 mm, the length of the grip portion to 30 mm, and the width of the parallel portion to 10 mm. The thickness is 5mm. The adhesive sheet (11) was integrated with the recirculating member, and the change in the tensile physical properties in the case of recycling was evaluated. It was confirmed that the addition was applied to any of the resins in the case where the adhesive sheet was not added, and the stretching was broken. The reduction in crack strength was 3%, and the decrease in tensile elongation at break was 4%, and any characteristic change had a suitable recycling characteristic of ±20% or less.

The following evaluations were carried out for the adhesive sheets obtained in the above examples, comparative examples and reference examples, and the results obtained are shown in Tables 1 to 3. Further, the loss tangent curve measured in the first embodiment is shown in Fig. 1 and displayed.

(Measurement of dynamic viscoelasticity)

The test piece obtained above was placed in a parallel disk-shaped measuring section using a viscoelasticity tester (trade name: Ares 2K STD, manufactured by Rheometrics Co., Ltd.), and stored at a frequency of 1 Hz and from -50 ° C to 150 ° C. The elastic modulus (G') and the loss elastic modulus (G"). The loss tangent tan δ is calculated according to the following calculation formula. The test piece is a plurality of sheets of the adhesive sheets of the respective examples and the comparative examples, so that the thickness of the substrate is substantially adhered. The thickness of the agent was 0.64 mm, and it was obtained by laminating.

Loss tangent tanδ=G"/G'

However, in the adhesive sheets (2) to (3) and (9) to (11), since the polystyrene base sheet, the ABS base sheet, and the polycarbonate base sheet are softened by heating, the measurement will be performed. It became difficult to measure the dynamic viscoelasticity of the adhesive sheets (2) to (3) and (9) to (11) by shifting the measured value of the adhesive sheet (1) used for the substrate sheet by Yupo SGS80.

(Measurement of initial adhesion Fa)

According to JIS Z 0237, the adhesive sheet is cut into a width of 25 mm and a length of 100 mm in a gas atmosphere at a temperature of 23 ° C and a relative humidity of 50%, and the arithmetic mean height Ra ( ³ ) of the contour curve defined in JIS B 0601 ²⁰⁰¹ is A 0.1 μm polystyrene plate was placed on the 2 kg roller at a pressure-adhesive speed of 5 mm/s and the pressure-adhesive number was applied back and forth for 24 hours. Next, using a tensile tester (RTA100 manufactured by A and D Co., Ltd.), the adhesive strength was measured by peeling at a speed of 50 mm/min and 90 degrees.

(Measurement of initial adhesion Fb)

According to JIS Z 0237, the adhesive sheet is cut into a width of 25 mm and a length of 100 mm in a gas atmosphere at a temperature of 23 ° C and a relative humidity of 50%, and the arithmetic mean height Ra ( ³ ) of the contour curve defined in JIS B 0601 ²⁰⁰¹ is A 7.0 μm polystyrene plate was placed and rubbed for 24 hours using a 2 kg roller at a pressure-adhesive speed of 5 mm/s and a pressure-adhesive frequency. Next, using a tensile tester (RTA100 manufactured by A and D Co., Ltd.), the adhesive strength was measured by peeling at a speed of 50 mm/min and 90 degrees.

(Measurement of the arithmetic mean height Ra ( ³ ) of the contour curve)

The arithmetic mean height Ra ( ³ ) (μm) of the profile curve used in the above-mentioned adhesion measurement according to JIS B 0601 ²⁰⁰¹ was measured in accordance with the following measurement methods. Using the surface shape measuring device Surfcom 575A (manufactured by Tokyo Seimi Co., Ltd.), the surface roughness of each sample of the polystyrene plate was measured by using a contact tip of 5 μmR, a diamond, a measuring force of 4 mN or less, and a measurement basis length of 10 mm. The arithmetic mean height of the contour curve (Ra ( ³ ); μm).

(evaluation of peel resistance)

The adhesive sheet is cut into a width of 25 mm and a length of 100 mm in a gas atmosphere having a temperature of 23 ° C and a relative humidity of 50%, and has an arithmetic mean height Ra ( ³ ) of 0.1 μm and a contour curve defined in accordance with JIS B 0601 ²⁰⁰¹ . On a polystyrene plate, a polyphenylene ether plate, an ABS plate, and a polycarbonate plate having a surface of 7.0 μm, the roller was pressed back and forth for 1 hour using a 2 kg roller. Next, after leaving it for 60 days in an environment of a temperature of 60 ° C and a relative humidity of 0 to 5%, the floating peeling state of the adhesive sheet was judged based on the visual observation.

○: For all the adherends, there was no floating peeling, and there was no problem.

△: No floating peeling was observed for a part of the adherend.

╳: For all adherents, floating peeling occurs.

(evaluation of re-peelability)

The adhesive sheet is cut into a width of 25 mm and a length of 100 mm in a gas atmosphere having a temperature of 23 ° C and a relative humidity of 50%, and has an arithmetic mean height Ra ( ³ ) of 0.1 μm and a contour curve defined in accordance with JIS B 0601 ²⁰⁰¹ . On a polystyrene plate, a polyphenylene ether plate, an ABS plate, and a polycarbonate plate having a surface of 7.0 μm, the roller was pressed back and forth for 1 hour using a 2 kg roller. Further, it is allowed to stand in an environment of a temperature of 60 ° C and a relative humidity of 0 to 5% for 60 days, and then placed in a gas atmosphere having a temperature of 23 ° C and a relative humidity of 50% for 1 hour, and then, along the tearing angle of 135 degrees, The speed of 1 m/min was judged by visual inspection to determine the state after tearing.

○: For all the adherends, no paste remains and it is easy to peel off.

△: For a part of the adherend, no paste remains and it can be peeled off.

╳: For the paste residue of the adhesive is significant, it is difficult to peel off again.

(Evaluation of recycling suitability: recycling reusability)

The adhesive sheet is cut into a width of 25 mm and a length of 100 mm in a gas atmosphere having a temperature of 23 ° C and a relative humidity of 50%, and has an arithmetic mean height Ra ( ³ ) of 0.1 μm and a contour curve defined in accordance with JIS B 0601 ²⁰⁰¹ . On a polystyrene plate, a polyphenylene ether plate, an ABS plate, and a polycarbonate plate having a surface of 7.0 μm, the roller was pressed back and forth for 1 hour using a 2 kg roller. Further, it was allowed to stand in an environment of a temperature of 60 ° C and a relative humidity of 0 to 5% for 60 days, and then left in a gas atmosphere having a temperature of 23 ° C and a relative humidity of 50% for 1 hour. Thereafter, the adhesive remains on the adherend, and the adhesive sheet is peeled off while the substrate sheet is not broken, and the ease of peeling work is evaluated.

○: For all the adherends, the adhesive residue or the crack of the base material sheet does not occur even if it is not intentionally designed, and it can be peeled off again, and the peeling workability is excellent.

△: For a part of the adherend, even if it is not intentionally designed, the residual of the adhesive or the crack of the base sheet does not occur, and the peeling workability can be performed.

╳: By heating with a hair dryer and peeling off very slowly, although peeling is possible, peeling workability is inferior.

╳╳: By heating with a hair dryer, and even if it is peeled off very slowly, the adhesive remains on the adhesive, and cracking of the base material sheet occurs, and peeling workability is extremely difficult.

(Evaluation of peeling resistance and removability of curved surfaces 1)

After printing on the adhesive sheet with UV ink, a 20 μm polypropylene film was laminated on the surface thereof through a 15 μm adhesive layer to make a width of 50 mm and a length. 50mm display label. Next, on the acrylic resin coating (curved surface) of the polyethylene extruded tube container coated with an acrylic resin on the surface, a visible label is attached, and three are placed in an environment of a temperature of 23 ° C and a relative humidity of 50%. In the month, the floating peeling state and the re-peelability of the visible label were determined by visual observation.

◎: There is no label floating peeling, and there is no problem in re-peelability.

○: Although only a very small number of labels were floated without a practical problem, the removability was in a state of no problem.

○~△: Although it was observed that only a very small number of labels floated and a very small amount of adhesive remained on the adherends, there was no practical problem of floating and the adhesive remained.

△: Although there is no floating peeling of the label, when the label is peeled off, the adhesive remains on the surface of the container or the substrate sheet is broken.

╳: Although there is no problem with re-peelability, the floating peeling of the label occurs remarkably.

╳╳: Floating peeling of the label occurs remarkably, and once the label is peeled off, the adhesive remains on the surface of the container, or the substrate sheet is broken.

(Evaluation of peeling resistance and removability of curved surfaces 2)

After printing on the adhesive sheet by offset printing, a 20 μm polypropylene film was laminated on the surface thereof through an adhesive layer to prepare a label having a width of 50 mm and a length of 50 mm. Then, it was adhered to the surface of polymethyl methacrylate having a radius of curvature of 25 mm, and left in an environment of a temperature of 23 ° C and a relative humidity of 50% for 3 months. The floating peeling state and the removability of the label were determined by visual observation.

◎: There is no label floating peeling, and there is no problem in re-peelability.

○: Although only a very small number of labels were floated without a practical problem, the removability was in a state of no problem.

○~△: Although it was observed that only a very small number of labels floated and a very small amount of adhesive remained on the adherends, there was no practical problem of floating and the adhesive remained.

△: Although there is no floating peeling of the label, when the label is peeled off, the adhesive remains on the surface of the container or the substrate sheet is broken.

╳: Although there is no problem with re-peelability, the floating peeling of the label occurs remarkably.

╳╳: Floating peeling of the label occurs remarkably, and once the label is peeled off, the adhesive remains on the surface of the container, or the substrate sheet is broken.

(evaluation of expansion)

For the stencil printing on the adhesive sheet, Yupo SGS80 was used for the adhesive sheets (1) and (H1) to (H3) of the substrate sheet, and a 20 μm polypropylene film was laminated on the surface thereof through a 15 μm adhesive layer. In the case of using the adhesive sheets (2) to (3) of the polystyrene film substrate, a 25 μm polystyrene film was laminated on the surface thereof through a 20 μm adhesive layer to prepare a label having a width of 70 mm and a length of 70 mm. Next, it adhered to the surface of the HIPS board, and it was left in the environment of temperature 60 degreeC and 90 degree of relative humidity for one day, and the expansion state of the label was judged by visual observation.

○: A state in which expansion is not observed.

○~△: When gazing, it was observed that there was little slight expansion that did not affect the degree of appearance.

△: Some slight expansion was observed.

╳: Significant bloat is a problematic label.

As is clear from Tables 1 to 3, the adhesive sheet for re-peeling obtained according to the present invention is not only a smooth surface for the adherend, but also has excellent adhesion even for a rough surface having irregularities, and once it is finished When the adhesive sheet is pasted, the floating peeling of the adhesive sheet or the like does not occur for a long period of time, and the adhesive is not contaminated by the adhesive when the adhesive sheet is peeled off.

Further, in the adhesive sheets of Examples 1 to 8, it was confirmed that the occurrence of bubble accumulation can be suppressed even if the adhering substance which is likely to be released by gas release is adhered.

[Possibility of industrial use]

According to the adhesive sheet for re-peeling according to the present invention, it is suitable for the following purposes: for the purpose of advertising for goods or services, in public containers such as cosmetics, cosmetics, beverages and foods, vending machines, and automatic ticket machines. The equipment installed in the place, or the adhesion of the vehicle used in public places such as electric cars and automobiles, or the name of the product, or the words and patterns used to indicate the operation instructions or parts replacement procedures for the user or the repairman. Various kinds of image information, such as copiers, printers, fax machines, personal computers, televisions, air conditioners, refrigerators, and washing machines; most of them are used in toner cartridges or ink cartridges. Or a variety of internal and external decorative parts, such as automobiles, locomotives, and building materials, which are peeled off after being adhered for a certain period of time.

In particular, the adhesive sheet of the present invention is suitable for the following applications: in the step of recycling, the adhesive sheet must be peeled off and adhered to polyphenylene having an arithmetic mean height Ra ( ³ ) of 0 to 10.0 μm in a surface profile curve. This member of an electrical product of a member formed of a thermoplastic resin having a main component of ethylene, polyphenylene ether, ABS, polycarbonate, and the like. Further, the adhesive sheet of the present invention is suitable for application to a surface which is a relatively rough member. It is more effective to adhere to the member having a Ra( ³ ) of 3.0 to 10.0 μm, and in particular, it is particularly effective after being applied to the member having a Ra( ³ ) of 5.0 to 10.0 μm.

Further, it is suitable for use in a curved surface having a surface layer mainly composed of an acrylic resin or the above-mentioned thermoplastic resin, and must be peeled off after being adhered for a certain period of time. In particular, it is suitable as a labeling material for a packaging container (a tube container used for cosmetics or cosmetics) which is adhered to polypropylene, polyethylene having a surface layer containing an acrylic resin as a main component, and a composite material containing the composite material as a main component. use. Alternatively, it is preferably formed by coating a metal coated with an acrylic resin as a main component or a plastic containing polymethyl methacrylate or the above thermoplastic resin as a main component, and the curved portion has a radius of curvature of 200 mm or less. The use of curved convex surfaces (bending parts of vending machines, corners of electrical products).

Fig. 1 is a loss tangent curve of the adhesive of Example 1 of the present invention.

Claims (10)

An adhesive sheet for re-peeling, which is a re-peelable adhesive sheet having an adhesive layer on at least one side of a substrate, characterized in that the adhesive layer is a water-dispersed acrylic emulsion-type adhesive containing an acrylic copolymer. The acrylic copolymer is polymerized in a total amount of 50 to 99% by mass of n-butyl acrylate and 2-ethylhexyl acrylate; the frequency of the adhesive layer is 1 Hz, -50. The loss tangent of the dynamic viscoelastic spectrum at ~150 °C is: (a) a low temperature region below -20 °C with a convex peak at the top; (b) a moderate peak at 10-40 °C with a convex peak below (c) The loss tangent at 70 ° C is 0.38 to 0.57. The adhesive sheet for re-peeling according to the first aspect of the patent application, wherein the mass ratio of (n-butyl acrylate/2-ethylhexyl acrylate) is 35/65 to 15/85. The adhesive sheet for re-peeling according to claim 1 or 2, wherein the adhesive layer is formed by using a water-dispersible acrylic emulsion type adhesive containing an acrylic copolymer, and the acrylic copolymer is polymerized. A monomer derived from n-butyl acrylate, 2-ethylhexyl acrylate, acrylic acid and methacrylic acid. The adhesive sheet for re-peeling of claim 3, wherein the total amount of the acrylic acid and methacrylic acid is 1.5 to 2.5% by mass in the monomer constituting the acrylic copolymer. The adhesive sheet for re-peeling according to item 4 of the patent application, wherein the ratio of methacrylic acid is 0.5 to 2.0 in terms of mass ratio with respect to the acrylic acid. The adhesive sheet for re-peeling according to item 1 of the patent application, wherein the adhesive The agent layer is formed by using a water-dispersible acrylic emulsion type adhesive containing an acryl-based copolymer which is emulsified and polymerized using an azo polymerization initiator in an amount of 50 to 99% by mass based on the total amount. A monomer derived from n-butyl acrylate and 2-ethylhexyl acrylate. The adhesive sheet for re-peeling according to the first aspect of the invention, wherein the water-dispersible acrylic emulsion type adhesive contains an oxazoline-based crosslinking agent. The adhesive sheet for re-peeling according to the seventh aspect of the invention, wherein the water-dispersible acrylic emulsion type adhesive contains an oxazoline crosslinking agent, and the oxazoline is related to the carboxyl group contained in the acrylic copolymer. The ratio of the base is 0.05 to 0.25 in terms of the functional group ratio. For example, the adhesive strip for re-peeling in the first application of the patent scope is 0.38~0.53 at 50°C in the high temperature range of 50~120°C; 0.40~0.65 at 100°C; 0.40~ at 120°C. 0.66. The adhesive sheet for re-peeling according to claim 1 or 2, wherein the storage modulus of the adhesive layer at a frequency of 1 Hz and 70 ° C is 6.0 × 10 ⁴ to 2.1 × 10 ⁵ Pa.