JP2006002064A - Fragrant sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fragrant sheet produced by a simple production step, having a rework property, free from residue of paste to a surface to be attached, free from defect of adhesive force by addition of a fragrance, radiating adequate aroma for a long period, preferably further excellent in see-through property and suitable for surface protection. <P>SOLUTION: An adhesive containing an adhesive component mainly composed of a material exemplified by a thermoplastic elastomer and a plasticizer exemplified by a naphthene oil and/or a liquid paraffin and a fragrant component having compatibility with the adhesive component as main components is used as an adhesive layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aromatic sheet, and more particularly, to an aromatic sheet having a simple structure and having a rework property in which an appropriate fragrance is diffused for a long period of time.

  Conventionally, in order to protect from scratches and dirt during processing and transportation, for surface protection, an adhesive layer is laminated on one side of a base film on the surface of synthetic resin plates, decorative plywood, metal plates, painted steel plates, etc. It is used by covering an adhesive film. Also, the display screens of flat panel displays such as TVs, PCs, mobile phones, etc. may be used with a surface protective adhesive film attached to protect the display screen from scratches and dirt even during use. Many. In recent years, attempts have been made to impart fragrance to an adhesive film for surface protection in order to improve comfort during use.

  As a method of imparting fragrance to the adhesive film as described above, (1) adding a resin containing a monomer having a polar group as a constituent unit and a fragrance to a polyolefin resin that is a raw material of a base film to impart fragrance A method (Patent Document 1) has been proposed. In addition, in order to impart fragrance to the pressure-sensitive adhesive layer, if the fragrance is added directly to the adhesive composition, the compatibility with the main agent of the adhesive is low, and the fragrance bleeds on the surface of the adhesive layer. Because there is a problem that the adhesiveness of the surface is impaired, (2) impregnated or adsorbed with a fragrance on a holding substrate made of porous ceramics such as countless fine silica and sepiolite, or powder or small particles A method of imparting fragrance by adding a fragrance-carrying agent to an adhesive (Patent Document 2), or (3) adding a fragranced microcapsule to a support and / or a thermal adhesive layer to improve fragrance. A method of giving (Patent Document 3) has been proposed.

JP 2003-201374 A Japanese Patent Laid-Open No. 11-089922 JP 11-149172 A

  However, since the whole surface of the base film described in Patent Document 1 is exposed to the atmosphere, the added fragrance is released from the entire surface of the base film, so that the fragrance strength is too strong. There is a drawback in that if the amount of addition is reduced in order to become a foul odor or to adjust to an appropriate emission rate, the emission life will be short. In addition, since the powder or capsule is added to the adhesive component in the adhesive layers described in Patent Document 2 and Patent Document 3, preparation of the powder and capsule is necessary, and the manufacturing process is performed. It is complicated and usually the transparency of the adhesive layer is impaired. Therefore, there is a drawback in that the transparency is impaired in the application to be applied as a protective film on the display surface. In addition, ordinary adhesives have the disadvantage of poor reworking properties such that once they are applied and then peeled off, adhesive residue is left on the peeled surface, and even if they are applied again, they cannot be applied cleanly.

The present invention improves the above disadvantages, has a simple manufacturing process, is reworkable, has no adhesive residue on the adherend surface, has no adhesion failure due to the addition of fragrance, and diffuses an appropriate fragrance for a long period of time. Preferably, the present invention provides a fragrant sheet having excellent transparency and suitable for surface protection.

The gist of the present invention is an aromatic sheet in which an adhesive layer is provided on one or both sides of a base sheet, and the adhesive mainly comprises an aromatic component that is compatible with the adhesive component. It is in the aromatic sheet | seat characterized by using an agent.

The fragrance sheet of the present invention is composed of a pressure-sensitive adhesive component and a fragrance component that are compatible with each other, so that the fragrance component can be blended as it is without secondary processing, and the process is simple. Despite the addition of the fragrance component to the adhesive layer, the adhesive layer has good transparency, and with regard to adhesiveness, it can be easily applied without entraining bubbles on the adhesive surface, and has reworkability. There is no adhesive residue on the adherend surface, and there is no fragrance component bleeding, so there is no adhesion failure. And moderate fragrance can be diffused over a long period of time from the end face of a thin adhesive layer.
The above-mentioned reworkability means that the pressure-sensitive adhesive layer surface is once adhered to the adherend and then peeled off. When the adhesive surface is again adhered to the same adherend, the same degree as when first adhered. It refers to the property of exhibiting tackiness and no rough skin at the adhesive interface.

The aromatic sheet of the present invention is formed by providing a pressure-sensitive adhesive layer containing an aromatic component on one side or both sides of a base sheet.

  The base sheet is an element that supports the pressure-sensitive adhesive layer, and such a base sheet is appropriately selected according to the purpose. For example, as a base sheet of various conventionally known pressure-sensitive adhesive sheets The sheet | seat currently used can be employ | adopted, Specifically, Polyolefin resin other than polyester resins, such as a polyethylene terephthalate (PET), a polybutylene terephthalate (PBT), a polyethylene naphthalate (PEN) etc., for example. Sheets made of polyamide resins, polycarbonate resins, polyimide resins, acrylic resins, polyvinyl chloride resins, etc., and mixed resins of two or more thereof, cellophanes, papers, woody sheets And metal sheets and earthenware plates. In addition, when the permeability of fragrance components such as the above-mentioned papers and woody sheets is too large, it is laminated with other impermeable films in order to suppress the permeability of the fragrance components and make them substantially impermeable. Or impregnated or coated with an impermeable resin.

  If desired, the above base sheet may have other additives, for example, pigments, dyes, antioxidants, antioxidants, fillers, ultraviolet absorbers, electrification, as long as the effects of the present invention are not adversely affected. An inhibitor and / or an electromagnetic wave inhibitor can be contained. Further, two or more types of sheets may be laminated within a range that does not adversely affect the effect of the present invention.

In addition, when the use of the aromatic sheet of the present invention is used for applications where transparency is important, such as a display surface, a transparent sheet is preferably used as the base sheet. For such applications, self-adhesion is particularly preferred, and PET film is particularly preferred from the viewpoint of ease of sticking. Examples of such commercially available PET film include Lumirror 50T60 (trade name, manufactured by Toray Industries, Inc.) and Emblet 38SC (trade name, manufactured by Unitika Ltd.). In addition, said self-adhesive means the characteristic in which the adhesive film which laminated | stacked this adhesive layer substantially shows adhesiveness with respect to a to-be-adhered surface by the pressure by self-weight.

  The thickness of the substrate sheet is appropriately selected depending on the application, but is usually about 10 μm to 10 mm from the viewpoint of surface protection, flexibility, perfume permeation suppression or the purpose of use thereof. Although it can be applied in the form of a plate or plate, it is 25 to 350 μm in the case of simply protecting the surface, and more practically 25 to 70 μm in the case of protecting the display surface or the like. When the adhesiveness of the surface of these substrate sheets is low, the surface on which the pressure-sensitive adhesive layer is formed can be subjected to surface treatment such as corona treatment, plasma treatment, blast treatment, etc., if necessary. However, corona treatment is usually employed practically.

  In order to improve the adhesiveness between the base sheet and the pressure-sensitive adhesive layer instead of or in addition to the above-described surface treatment, an anchor adhesive layer may be provided in advance on the base sheet surface as necessary. . Although it does not specifically limit as said adhesive layer for anchors, In light of the below-mentioned adhesive layer component, the adhesive component which contains a carboxylic acid modified thermoplastic elastomer and a crosslinking agent as a main component is mentioned suitably. .

  As the carboxylic acid-modified thermoplastic elastomer constituting the anchor adhesive layer, various carboxylic acid-modified styrene-based thermoplastic elastomers can be used. Examples of the carboxylic acid modification include aliphatic saturated monocarboxylic acids such as propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, vivalic acid, lauric acid, myristic acid, palmitic acid, stearic acid; succinic acid, Aliphatic saturated dicarboxylic acids such as glutaric acid, adipic acid, hymelic acid, suberic acid, azelaic acid and sebacic acid; aliphatic unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, oleic acid; and , May be derived from an aliphatic unsaturated dicarboxylic acid such as maleic acid, fumaric acid, citraconic acid or mesaconic acid. Among these, those modified with an aliphatic unsaturated dicarboxylic acid are preferable, and those modified with maleic acid are more preferable.

  The carboxylic acid-modified thermoplastic elastomer may be, for example, a hydrogenated carboxylic acid-modified thermoplastic elastomer, such as a hydrogenated carboxylic acid-modified styrene-butadiene elastomer, specifically a maleic acid-modified SEBS elastomer. Is mentioned. When a hydrogenated carboxylic acid-modified styrene-butadiene elastomer is used as the hydrogenated thermoplastic elastomer, the melt index is, for example, 2.5 to 25 g / 10 2 at 200 ° C. and 5 kg. What is a minute is preferable and what is 3-7 g / 10min is more preferable.

  In the present invention, when a hydrogenated carboxylic acid-modified thermoplastic elastomer is used, the hydrogenation rate is preferably substantially 100%, but may be less than that as long as the effect of the present invention is obtained. Good. When a carboxylic acid-modified SEBS elastomer is used, the mass ratio of styrene: ethylene + butylene is, for example, preferably 10:90 to 40:60, and more preferably 20:80 to 30:70. Further, the acid value of the hydrogenated carboxylic acid-modified thermoplastic elastomer is preferably 2 to 10. Within the range, those having an acid value of less than 3 can be colorless and transparent, while those having an acid value of 3 to 10 can be yellowish. Examples of commercially available carboxylic acid-modified thermoplastic elastomers or hydrogenated products thereof include Tuftec M1911, M1913, M1943 (trademark, manufactured by Asahi Kasei Kogyo Co., Ltd.), and FG-1901X (trademark, Kraton Polymer). Company products).

  The type of the crosslinking agent blended in the anchor adhesive layer is not particularly limited and can be appropriately determined in consideration of the type of the carboxylic acid-modified thermoplastic elastomer to be used. For example, Coronate HL ( Hexamethylene diisocyanate-burette type (trademark, product of Nippon Polyurethane Industry Co., Ltd.) can be used.

  The compounding ratio of the carboxylic acid-modified thermoplastic elastomer and the crosslinking agent is not particularly limited, but from the viewpoint of the balance between the adhesiveness of the adhesiveness to the base sheet and the adhesiveness to the pressure-sensitive adhesive layer. For example, it is preferably 100: 1 to 2: 1, more preferably 100: 1 to 4: 1, and even more preferably 50: 1 to 12: 1.

  In addition to the main components described above, additives such as antistatic agents can be added to the adhesive component. Examples of the antistatic agent include Elegan 264wax (trademark, manufactured by Nippon Oil & Fats Co., Ltd.) which is a cationic antistatic agent. The amount of the antistatic agent is usually based on the mass of the adhesive. 0.1-3.6 mass% is preferable, and it is set as 0.6-1.8 mass%. By setting the amount within such a range, the occurrence of so-called “Yuzuhada” can be satisfactorily prevented.

  The above-mentioned anchor adhesive layer is prepared by dissolving the above-mentioned carboxylic acid-modified thermoplastic elastomer, cross-linking agent and other additives in an appropriate organic solvent to form an adhesive liquid, which is applied to the surface of the base sheet. And dried to form. The organic solvent is not particularly limited as long as it has solubility in the above elastomer, and for example, toluene can be preferably mentioned. Moreover, the usage-amount should just be able to use a solution as an adhesive liquid, and is 200-500 mass parts normally with respect to a total of 100 mass parts of the elastomer and plasticizer which are said main components, Preferably it is 250-350 mass parts Is done.

  The application method of the adhesive liquid may be a known method, but specific examples include a roller coating method, a brush coating method, a spray coating method, a dip coating method, a die coater, a bar coater, a knife coater, and the like. The method used is mentioned. The coating amount is not particularly limited, but usually the thickness after drying is 1 to 50 μm, preferably 1 to 15 μm, more preferably 2 to 5 μm. The above adhesive liquid coating layer is usually dried in warm air at 80 to 150 ° C. for 20 to 60 seconds, preferably in hot air at 100 to 130 ° C. for 30 to 50 seconds to form an adhesive layer for anchors. And it can apply as an anchor layer of the below-mentioned adhesive layer.

  The pressure-sensitive adhesive layer is usually formed on the surface of the base sheet, or on the surface of the adhesive layer for anchors formed as described above depending on the use or required characteristics of the product.

The pressure-sensitive adhesive layer includes a pressure-sensitive adhesive component composed mainly of a thermoplastic elastomer and a plasticizer, and an aromatic component that is substantially compatible with the pressure-sensitive adhesive component. The above-mentioned pressure-sensitive adhesive component composition is selected in combination so that the thermoplastic elastomer is plasticized by the plasticizer, the cohesive force is reduced, and the self-adhesiveness is improved.

  Although it does not restrict | limit especially as a thermoplastic elastomer which has said property, For example, what is comprised by the block segment which consists of a block of a styrene monomer and a block of a rubber monomer can be mentioned. Specific examples of the thermoplastic elastomer include polystyrene-polyisoprene-polystyrene (SIS), polystyrene-polybutylene-polystyrene (SBS), polystyrene-poly (ethylene / butylene) block-polystyrene (SEBS), polystyrene-poly (ethylene / ethylene / polyethylene). Examples include propylene) block-polystyrene (SEPS), polystyrene-polyisoprene (SI), polystyrene-polybutylene (SB), and polystyrene-poly (ethylene / propylene) block (SEP).

The degree of polymerization of the elastomer can be appropriately selected according to the type of plasticizer to be added, the amount added, and the properties expected as an adhesive. For example, in the case of SEBS, the mass average molecular weight is usually 15,000 to Those having 500,000 are preferably used, and those having 100,000 to 500,000 are more preferably used.

  Further, the above plasticizer is effective for adding self-adhesiveness to the above-mentioned elastomer, but as such a plasticizer, the thermoplastic elastomer component to be used has a polystyrene phase and a rubber phase. In this case, a high molecular weight compound having a high affinity for the rubber phase and a low affinity for the polystyrene phase is preferable, and as the plasticizer, naphthenic oil and / or liquid paraffin is preferable.

  As said naphthenic oil, that whose flash point is 100-300 degreeC is preferable, and the thing of 150-280 degreeC is more preferable. The pour point is preferably -30 to -5 ° C, more preferably -25 to -10 ° C. Moreover, that whose specific gravity is 0.83-0.87 is preferable, and what is 0.837-0.868 is more preferable. Furthermore, the thing whose carbon number is 3-8 is preferable, and the thing of 5-6 is more preferable.

  On the other hand, in the case of liquid paraffin, the flash point is preferably 100 to 300 ° C, more preferably 150 to 280 ° C. The pour point is preferably -30 to -5 ° C, more preferably -25 to -10 ° C. In addition, the specific gravity is preferably 0.89 to 0.91, and more preferably 0.8917 to 0.9065. Furthermore, that whose carbon number is 20-35 is preferable, and the thing of 21-33 is more preferable. The mixing ratio of the thermoplastic elastomer, which is the main component constituting the pressure-sensitive adhesive component, and the plasticizer is usually 5:95 to 95: 5, preferably 10:90 to 90:10 as a mass ratio. The

The fragrance component is appropriately selected from those that are substantially compatible with the above-mentioned pressure-sensitive adhesive component in consideration of the use environment of the product fragrance sheet, the user's preference, etc. If desired, two or more can be combined.

Among the above aromatic components, liquid components include, for example, linalyl acetate (pergamut-like scent), isoamyl salicylate (orchid-like scent), benzyl salicylate (slightly sweet scent), and terpinyl acetate (similar to lavender). Scent), tricyclodecenyl acetate, butyl cyclohexyl acetate, benzyl acetate (jasmine fragrance), eugenol acetate (scent like clove), geranyl acetate (rose fragrance) citronellyl acetate (rose-like fruit) Scent) Cinnamyl acetate (soft sweet flower scent), dihydroterpinyl acetate (fresh pine citrus-like scent), dimethylbenzyl carvinyl acetate (lilac), geraniol (weak flower scent similar to rose), isoamyl acetate (Fragrance similar to pear), isoeugenol acetate, isobutyl acetate ( Fruity flavor), ethyl cinnamate, cuminaldehyde (curry aroma), cinnamic aldehyde, l-carvone (smells like spearmint oil), ethyl formate, geranyl formate, citronellyl formate, ethyl caprylate ( Aroma resembling pineapple), allyl caproate (fragrance resembling pineapple), ethyl caproate (fragrance resembling apple and pear), galaxolide, ethyl-3,5,5-trimethylhexanoate (sweet green note) , Ethylene dodecanedioate (musk fragrance), ethylene brushate (ja fragrance), eugenol (fragrance similar to clove), 10-oxahexadecanolide (ja fragrance), ethyl isovalerate, allyl isothiocyanate (unique Strong pungent odor), Iron (violet fragrance), γ-undecalactone (oily fragrance), Undecylenaldehyde (aroma like rose citrus), methyl benzoate, isoeugenol (aroma similar to carnation), isocamphylcyclohexanol (sandalwood aroma like musk), isoamyl isovalerate (similar to apple, banana) Fragrance), ethyl acetoacetate, acetophenone, anisaldehyde (smelling scent), limonene and pentene, rosinol (scent like rose, geranium), isopropyl butyrate (scent like strong fruit), ethyl butyrate (fruit Fragrance), butyl butyrate (fruit fragrance), linalool (lily of the lily of the valley), α-ionone, isoamyl butyrate (pear, banana fragrance), ethyl ethyl phenylglycidate (strawberry fragrance), p-Methylacetophenone (fragrance resembling a flower Benzyl propionate (banana, strawberry fruit scent), hexyl cinnamaldehyde (sweet scent), benzyl alcohol (cream scent), ethyl phenylacetate (honey-like scent), pt-butyl-α-methylhydro Synamic aldehyde (lily aroma), isoamyl propionate (pineapple, pear-like aroma), ethyl propionate (pineapple aroma), hydroxytronete (lily flower), 4 (3)-(4-hydroxy- 4-methylpentyl) -3-cyclohexene-1-carboxaldehyde (fragrance like lily of the valley), phenylaldehyde (excellent scent of hyacinth), β-phenylethyl alcohol, β-naphthylmethyl alcohol (coconut fragrance), dimethyl Benzyl carbinol (lilac, na Lucis), jasmine lactone, decylaldehyde (flower-like fragrance), tetrahydrolinalol (rose, lily-like fragrance), terpineol (lilac fragrance), 1,8-cineole (fragrance like camphor), dihydrojasmine Methyl acid (jasmine-like fragrance), dihydrojasmine (strong flower fragrance), citral (strong lemon fragrance), citronellal (salmon fragrance), citronellol (rose-like fragrance), allyl cyclohexylpropionate (pineapple fragrance) ), Linalyl acetate (scent similar to bergamot), isoamyl salicylate (scent like orchid), benzyl salicylate, methyl salicylate (strong scent similar to winter green) and modified products thereof.

Among the above aromatic components, examples of the solid component include isoeugenol acetate, tetrahydronaphthalene, ethyl vanline, cinnamic acid, cedolyl acetate, β-naphthylmethyl ether, vanillin, rosephenone, and modified products thereof.

The amount of the fragrance component added to the pressure-sensitive adhesive component is not particularly limited. However, as the fragrance component increases, the pressure-sensitive adhesiveness decreases, so that the pressure-sensitive adhesive is usually composed mainly of a thermoplastic elastomer and a plasticizer. It is 20 mass% or less with respect to solid content of an agent component, and is 1-15 mass% practically.

The above-mentioned pressure-sensitive adhesive component and fragrance component are usually dissolved in a solvent that can dissolve these components in common, such as toluene, to form a pressure-sensitive adhesive solution, and the base material sheet or anchor adhesive layer is formed on the surface. It is applied to one or both sides of the base material sheet and dried to form an adhesive layer. The amount of the organic solvent used for the above-mentioned dissolution is not particularly limited, but is usually 200 to 400 parts by mass, preferably 100 to 100 parts by mass with respect to a total of 100 parts by mass of the elastomer and plasticizer as the main components. Is 250 to 350 parts by mass.

  The coating amount of the pressure-sensitive adhesive layer is usually 10 to 100 μm after drying, and practically 25 to 50 μm. The above coating method may be a known method, and examples thereof include a method using a die coater, a bar coater, a knife coater, etc. in addition to a roller coating method, a brush coating method, a spray coating method, and a dip coating method. And said application layer forms an adhesive layer by drying for 40 to 90 second in 30 to 120 second normally in warm air of 80-150 degreeC, Preferably in 100-130 degreeC warm air. The aromatic sheet of the present invention can be obtained.

On the surface of the pressure-sensitive adhesive layer of the aromatic sheet having the pressure-sensitive adhesive layer formed as described above, the necessity during the production process, prevention of fragrance components from being released before practical use, and protection of the surface stickiness For example, a release layer can be provided. In view of the action of preventing the diffusion of the fragrance component at the stage before practical use as described above, such a release layer is preferably a material that can suppress the transmission of the fragrance component. As such a release layer, for example, Examples include, but are not limited to, PET film having a silicone treatment on the surface and polyolefin film having a silicone treatment. In addition, in said manufacturing process, when providing the adhesive layer for anchor layers, in order to stabilize the quality of the obtained aromatic sheet, before use or shipment, in an environment of 40 to 80 ° C., 2 to Aging for 60 days is preferred.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[Example 1]
As the base material sheet, a 75 μm thick PET film (Lumirror 75T60, manufactured by Toray Industries, Inc .: hereinafter referred to as base material PET film) was used. Next, 17 parts by mass of SEBS elastomer (mass average molecular weight 250,000) and naphthenic oil as a plasticizer (flash point 220 ° C., pour point −25 ° C., specific gravity 0.8387, carbon number 5 to 5) 6) After 83 parts by mass were dissolved using 270 parts by mass of toluene, 10 parts by mass of AR25204 (trade name, manufactured by Ogawa Fragrance Co., Ltd.) exhibiting the scent of grapefruit as an aroma component was added and stirred and dissolved well. An adhesive coating solution was obtained. This coating solution was applied to one side of the substrate sheet using a Mayer bar, and heated and dried in hot air at 100 ° C. for 1 minute to obtain an aromatic sheet having a 45 μm thick adhesive layer. On the surface of the pressure-sensitive adhesive layer of this aromatic sheet, a 75 μm-thick PET film (hereinafter referred to as a release film) having a surface treated with silicone was laminated as a release layer.

After taking 3 test pieces from the above aromatic sheet and peeling off the release film, the total light transmittance of each sheet was measured using a C light source haze meter HGM-2 (manufactured by Suga Test Instruments Co., Ltd.). When measured, all were 90% or more.

  (1) A strip-shaped test piece having a width of 25 mm and a length of 250 mm is cut from the above aromatic sheet, and the surface of the pressure-sensitive adhesive layer is measured according to the adhesive strength test method of JIS Z 0237 using Shimadzu Autograph AGS-50D. After the release film was peeled off, the pressure-sensitive adhesive layer surface was pressure-bonded to the glass surface as the adherend, and the presence or absence of entrained bubbles on the pressure-sensitive adhesive surface was evaluated. For those left in an oven at 30 ° C. for 30 minutes, the aromatic sheet is peeled off at a peeling speed of 300 mm per minute by a peeling angle 180 ° method, and the adhesive force between the adhesive surface and the glass surface as the adherend ( (Adhesive surface adhesive strength) was measured, and the average value of the measured values of each of the three test pieces was taken as the adhesive strength. Furthermore, the adhesive residue state of the peeling surface on the glass plate side was observed with a 100 × microscope. Subsequently, for the test piece aged at 30 ° C. for reworkability evaluation, the pressure-sensitive adhesive surface was pressure-bonded again to the glass surface, and after observing the rough surface of the pressure-sensitive adhesive interface, the peeling angle 180 degree method was repeated again as described above. , Peeling at 300 mm / min., Measuring the adhesive strength between the adhesive surface and the glass surface (adhesive surface adhesive strength), and the average of the measured values of each of the three test pieces Power.

(2) Separately, the base PET film surface of the test piece prepared in the same manner as in the case of (1) above was fixed to the test plate surface made of a polypropylene plate having a thickness of 5 mm via a double-sided adhesive tape, A PET film (thickness 25 μm, width 25 mm) as an adherend is pressure-bonded to the surface of the pressure-sensitive adhesive layer, and the presence or absence of entrained bubbles on the pressure-sensitive adhesive surface is evaluated. And an aging treatment at 80 ° C. for 30 minutes, and then the aromatic sheet is peeled off at a peeling speed of 300 mm per minute by a peeling angle 180 ° method, between the adhesive surface and the PET film surface as the adherend. The adhesive strength (adhesive surface adhesive strength) was measured, and the average value of the measured values of each of the three test pieces was taken as the adhesive strength. Further, the remaining adhesive state of the peeled surface on the PET film side as the adherend was observed with a 100 × microscope. Next, for evaluation of reworkability, a test piece aged at 30 ° C. was again pressure-bonded with a PET film as an adherend to the adhesive surface, and after observing rough skin at the adhesive interface, the peeling angle was subsequently followed as described above. The fragrance sheet was peeled off at a peeling rate of 300 mm per minute by the 180 degree method, and the adhesive force (adhesive surface adhesive strength) between the adhesive surface and the PET film surface as the adherend was measured. The average value of the measured values was defined as the adhesive strength during re-adhesion.

(3) Separately, for the test piece prepared in the same manner as in the above (1), the base PET film surface was fixed to the test plate surface made of a polypropylene plate having a thickness of 5 mm via a double-sided adhesive tape, After aging treatment at 30 ° C. for 30 minutes in a state where the release film is laminated on the surface of the pressure-sensitive adhesive layer, the release film is removed, and a release port is provided at the interface between the base material PET film and the pressure-sensitive adhesive layer. Grasping the pressure-sensitive adhesive layer, peeling off the pressure-sensitive adhesive layer at a peeling speed of 300 mm per minute by the peeling angle 90 degree method, and measuring the adhesive force between the base PET film surface and the pressure-sensitive adhesive surface, 3 The average value of the measured values of the test piece was defined as the adhesive strength.
In addition, what was aged for 30 minutes at 80 ° C. has a strong adhesive force between the base PET film surface and the adhesive surface, and the adhesive layer is cut at the stage of providing a release opening at the interface with the adhesive layer. Therefore, the measurement was stopped.

(4) Separately, from the obtained aromatic sheet of the present invention, a test piece having a length of 10 cm and a width of 6 cm was cut, the surface release film was peeled off, and the exposed adhesive surface was used as an adherend. A test piece for evaluating aroma durability was attached to the surface of a soda glass plate having a length of 29 cm and a width of 21 cm. At the time of this sticking, the pressure-sensitive adhesive surface could be stuck so as to be smoothly sucked onto the glass surface without entraining bubbles. Place this specimen on a quiet indoor table with good ventilation and room temperature within a range of 10-30 ° C., and once a week, bring your face close to the position about 30 cm above the specimen, The fragrance derived from the fragrance component contained in the test body was sniffed, and the period until the fragrance could not be felt, that is, evaluation of fragrance durability was continued. As a result, it was possible to sense the fragrance even after 6 months. The above results are shown in Table 1.

[Example 2]
As an anchor layer adhesive solution, maleic acid-modified SEBS Tuftec M1911 (melt index is 3.5 g / 10 min, styrene: ethylene + butylene mass ratio is 30:70, acid value is 2, manufactured by Asahi Kasei Kogyo Co., Ltd.) 13 parts by mass was charged into 87 parts by mass of toluene and dissolved using a propeller stirrer. To 100 parts by mass of this solution, 1.04 parts by mass of Coronate HL and 0.13 parts by mass of Elegan 264wax as an antistatic agent were added at room temperature to obtain an adhesive solution. This adhesive solution is applied to the same substrate sheet as used in Example 1 using a Mayer bar, and dried in 120 ° C. hot air for 40 seconds to form an anchor adhesive layer having a thickness of 2 μm. Formed. On the above-mentioned anchor adhesive layer, the pressure-sensitive adhesive layer was applied in the same manner as in Example 1 so that the thickness after drying was 45 μm and dried to obtain an aromatic sheet.

In the case of Example 1, after laminating a PET film having a thickness of 75 μm whose surface was silicone-treated as a release layer on the surface of the pressure-sensitive adhesive layer of the above aromatic sheet, and then aging for 4 days in a room at 45 ° C. In the same manner as above, presence or absence of entrained bubbles on the adhesive surface, transparency, fragrance durability, adhesive strength (between the adhesive surface and the glass surface as the adherend, between the adhesive surface and the PET film surface as the adherend, and the substrate PET Film surface-adhesive layer) and the adhesive residue on each peeled surface were evaluated. Furthermore, for evaluation of the reworkability, the peeled surface of the test piece aged at 30 ° C. was re-adhered to each adherend, and the rough surface and the adhesive strength of the adhesive interface at that time were evaluated. The results are shown in Table 1 as in the case of 1.

  As is clear from the results of the above examples (Table 1), in any of the test pieces, no bubbles are involved in the first adhesive interface, and no bubbles are involved in the re-adhered interface on the release surface. There was no rough skin. In addition, transparency and fragrance endurance time are at a level that can be satisfactorily satisfied. Further, regarding adhesive strength, those that were not subjected to high-temperature aging at 80 ° C. are reduced in adhesive strength even if they are peeled once and then re-adhered. Was not recognized.

In the aromatic sheet of the present invention, the pressure-sensitive adhesive layer is composed mainly of a pressure-sensitive adhesive component and a fragrance component that are substantially compatible with each other. Despite being simple and having an aromatic component added to the adhesive layer, the adhesive layer has good transparency, and with regard to adhesiveness, it can be easily affixed without entraining bubbles on the adhesive surface. There is no adhesive residue on the adherend surface, and there is no fragrance component bleeding, so there is no adhesion failure. And moderate fragrance can be diffused over a long period of time from the end face of a thin adhesive layer.
Therefore, when using a substrate sheet having substantially transparency, for example, when used as a protective sheet for display screens of various flat panel displays, the transparency of the screen is not impaired. Industrial effects are significant.

Claims (11)

A sheet in which a pressure-sensitive adhesive layer is provided on one or both sides of a base sheet that does not substantially allow perfume to pass, and the pressure-sensitive adhesive layer is mainly composed of a pressure-sensitive adhesive component and a fragrance component that is substantially compatible therewith. An aromatic sheet characterized by comprising an adhesive.
The aromatic sheet according to claim 1, wherein the adhesive component comprises a thermoplastic elastomer and a plasticizer as main components.
The aromatic sheet according to claim 2, wherein the thermoplastic elastomer is a polymer composed of a block segment composed of a block of a styrene monomer and a block of a rubber monomer.
The aromatic sheet according to claim 2 or 3, wherein the plasticizer is naphthenic oil and / or liquid paraffin.
The aromatic sheet according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer has reworkability.
The aromatic sheet according to any one of claims 1 to 5, wherein the base sheet is a plastic film.
The aromatic sheet according to any one of claims 1 to 6, wherein the base sheet is a biaxially stretched polyethylene terephthalate film.

The aromatic sheet according to any one of claims 1 to 7, wherein a release layer is provided on the pressure-sensitive adhesive layer.
9. An anchor adhesive layer mainly comprising a carboxylic acid-modified thermoplastic elastomer and a crosslinking agent is interposed between the pressure-sensitive adhesive layer and the base sheet layer. The aromatic sheet as described in any one of them.
The aromatic sheet according to any one of claims 1 to 9, which is substantially transparent as a whole.
The aromatic sheet according to claim 10, which is used as a protective film for a display screen of a flat panel display.