JP2007186649A - Heat-sealing pressure-sensitive adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive which has an excellent transparency, scarcely entraps air bubbles in a bonding interface, does not lose the transparency and has the re-workability allowing an easy re-application, even if air bubbles are entrapped and increases its adhesion strength by heating, after it is applied, and a heat-sealing pressure-sensitive adhesive sheet in which a layer of the adhesive is formed on an substrate sheet. <P>SOLUTION: The heat-sealing pressure-sensitive adhesive sheet is obtained by forming a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive component containing a thermoplastic elastomer and a plasticizer on the surface of a substrate layer. A sheet-like pressure-sensitive adhesive is obtained by forming the adhesive layer on the surface of the release layer of a release sheet. The adhesive strength is strengthened by heating the part containing the adhesive layer and the pressure-sensitive adhesive layer, after the heat-sealing pressure-sensitive adhesive sheet is applied or an article is adhered via the sheet-like heat-sealing pressure-sensitive adhesive. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention can be suitably used to efficiently protect a surface (protected surface) that is required to be protected, such as a display screen of a television, a personal computer, or a mobile phone, or a POP advertisement. The present invention relates to a heat-sealable self-adhesive sheet that can also be used as a temporary fixing material for electric and electronic parts, a sealing material for a test container, and a barcode label. More specifically, the present invention relates to a heat-sealable self-adhesive sheet that can be repeatedly applied to and peeled from various adherend surfaces.

Conventionally, there has been a demand for a film that can be suitably used for efficiently covering a surface requiring protection and a surface to be protected.
For example, it has low dependence on pressure bonding at the time of bonding, and can be easily bonded (temporarily attached) to the surface of various materials (protected bodies) including metal plates even after being pressed at low pressure. A surface protective film having excellent re-peelability has been proposed (see, for example, Patent Document 1).
Further, there has been proposed a transparent conductive heat seal material that does not deteriorate its antistatic performance even at low humidity and has a transparency that allows the contents to be visually recognized, and a carrier tape lid using the same (for example, patent document). 2).
Surface protection with a pressure-sensitive adhesive layer on a substrate that has good adhesiveness during bonding, has very little change over time in the adhesive strength after bonding, and has practical weather resistance. A material has been proposed (see, for example, Patent Document 3).
Furthermore, a self-adhesive elastomer sheet composed of a polymer composition in which an epoxidized diene block copolymer and a hydrogenated diene block copolymer are blended has been proposed. It remains (for example, refer to Patent Document 4).

  On the other hand, with the recent spread of liquid crystal televisions, plasma display panel (PDP) televisions, personal computers, mobile phones, electronic notebooks, etc., they can be used to efficiently protect their protected surfaces (display screens). Development of a surface protective film that can be used has been demanded. In such a surface protective film, for example, in many cases, such transparency as to be able to visually recognize those screens is often required, as well as adhesion to the protected surface (adhesion strength and ease of adhesion), external load ( For example, resistance to scratching and peeling) is regarded as important.

Further, in general, a film composed of an adhesive layer and a base material layer has also been proposed, such as an aspect in which a film colored with advertising characters and / or patterns is attached to an adherend surface of various storefront glasses, etc. In this case, if you try to change the layout of the paste, the adhesive layer remains on the adherend surface at the time of peeling, so it is necessary to wipe and clean it. It was difficult to repeatedly apply to the adherend surface.
As described above, the adherend surface is composed of various materials, for example, plastic, metal, fiber, glass, and the like, and has various shapes, for example, shapes such as a plane, a curved surface, and an uneven surface. It is desired to provide a film that can be applied and peeled off easily and repeatedly and that is excellent in appearance and durability.
However, since the film that can be easily applied as described above is easily peeled off on one side, in industrial applications, it can be applied easily, including reattachment, but once the application position is determined A pressure-sensitive adhesive sheet and a pressure-sensitive adhesive that can provide a strong adhesive strength that does not easily peel off are desired. That is, there is a demand for a pressure-sensitive adhesive that can remarkably enhance the adhesive strength after pasting.

JP 2001-139898 A JP 2001-348561 A JP-A-8-245938 JP-A-8-81616

  The present invention has been made on the basis of the above-mentioned demands, that is, it is extremely excellent in air removal at the time of pasting, is excellent in transparency and pasting workability, and has an adhesive strength as desired after pasting. It aims at providing the heat-sealable self-adhesive sheet which can be strengthened.

The first gist of the present invention resides in a heat-sealable self-adhesive sheet characterized by forming a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive component containing a thermoplastic elastomer and a plasticizer on the surface of a base sheet.
The second gist of the present invention is a heat characterized in that a pressure-sensitive adhesive layer that can be used for the heat-sealable self-adhesive sheet is formed on the release treatment surface of a substrate sheet having releasability. It exists in a sealing self-adhesive sheet-like adhesive.
And the third gist of the present invention is that the above-mentioned heat-sealable self-adhesive sheet is attached to the adherend surface, or the article is attached via the above-mentioned sheet-like adhesive, and then the adhesive layer and The present invention resides in a method for adhering a base sheet or an article, wherein the adhesive strength is enhanced by heating a portion including an adhesive layer.

The heat-sealable self-adhesive sheet of the present invention is extremely excellent in the speed of air removal at the time of pasting and the extrudability of mixed air, and in addition to being excellent in transparency and laminating workability, it peels off from the adherend surface. Even when this occurs, adhesive residue is effectively prevented.
Therefore, the heat-sealable self-adhesive sheet of the present invention can be easily applied and peeled repeatedly on various adherend surfaces. Furthermore, it is possible to efficiently prevent the air (air) from remaining with the adherend surface during pasting, and a desired surface can be obtained.
Further, after bonding the heat-sealable self-adhesive sheet, or after pasting the article via the sheet-like pressure-sensitive adhesive, the adhesive strength is obtained by heating the part including the adhesive layer and the pressure-sensitive adhesive layer. Can be strengthened. Further, the sheet-like pressure-sensitive adhesive can be easily transferred to a base material sheet as an object to be bonded to easily obtain a heat-sealable self-adhesive sheet.

“Self-adhesive” in the present invention means that only the self-weight of the pressure-sensitive adhesive sheet can be applied to the adherend surface without using any other pressure-sensitive adhesive and without applying additional pressure or heat. Means the nature of the film that can be more adherent.
The heat-sealable self-adhesive sheet of the present invention, in addition to the self-adhesiveness, by selecting a base material sheet, flexibility, for example, starting attachment from one end to the adherend surface, to the other end By advancing the pasting, it is possible to have the flexibility of completing the pasting. For example, the heat-sealable self-adhesive sheet of the present invention can be prepared so as to have a degree of flexibility that allows the sheet to be tightly attached only by the pressure generated by gravity applied to the sheet itself. .

The total thickness of the heat-sealable self-adhesive sheet of the present invention can be appropriately determined in consideration of the durability and flexibility required for the sheet, but is preferably, for example, 1 to 450 μm, more preferably 30-275 μm. In addition, the heat-sealable self-adhesive sheet of the present invention preferably has transparency to such an extent that, for example, the adherend surface is a display screen of a television or a computer, such as colorless and transparent. In some cases, it may be colored and transparent or opaque.
On the other hand, examples of the adherend surface to which the heat-sealable self-adhesive sheet of the present invention is attached include those made of various materials, such as plastic, metal, fiber, and glass. Further, the adherend surface may have various shapes such as a flat surface, a curved surface, and an uneven surface. As a specific example of the adherend surface, for example, it may be used as a POP advertisement to be affixed to a television, a computer, a mobile phone and an electronic notebook display screen, various storefront glasses, or a barcode label to be affixed to various product containers. it can.
In addition, using the property that can increase the adhesive strength by heating after pasting, it can also be used for pasting parts such as sheet-like materials to electrical and electronic parts such as IC chips and capacitors, various test containers, and industrial machines. Available.

The present invention is described in detail below.
The heat-sealable self-adhesive sheet of the present invention is formed by forming a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive component containing a thermoplastic elastomer and a plasticizer on the surface of a base sheet layer, if desired, via an adhesive layer.

  In the present invention, the base sheet has a surface that is in close contact with the adhesive layer described later, and when the heat-sealable self-adhesive sheet as a product is attached to the adherend surface, the adherend surface is scratched and peeled off. It can function to protect against external loads such as. Such a base sheet is not particularly limited, and those usually used in conventional heat-sealable self-adhesive sheets or surface protective films can be used, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT). In addition to polyester resins such as polynaphthalene terephthalate (PEN), polyolefin resins such as polyethylene and polypropylene, plastic films made from polyamide resins, polycarbonate resins, acrylic resins, polyvinyl chloride resins, and paper There can be mentioned.

The thickness of the substrate sheet is arbitrary and can be determined as appropriate. For example, the thickness is 10 to 350 μm, preferably 25 to 200 μm. In practice, necessary strength, flexibility, and the like are taken into consideration. To be selected. Examples of such commercially available base sheet include Lumirror 50T60 (PET film, easy adhesion treatment, manufactured by Toray Industries, Inc.), Emblet 38SC (single-sided corona-treated PET film, manufactured by Unitika Ltd.), Teonex Q51 (PEN film, Teijin DuPont Films Ltd.).

If necessary, the base sheet can be subjected to easy adhesion treatment, for example, corona treatment, plasma treatment, blast treatment, etc. on one side, that is, one side or both sides, preferably one side. In addition, if necessary, other additives such as pigments, dyes, antioxidants, anti-aging agents, fillers, ultraviolet absorbers, antistatic agents and / or electromagnetic waves within the range not adversely affecting the effects of the present invention. An inhibitor or the like may be included.

Various components can be used as the thermoplastic elastomer constituting the pressure-sensitive adhesive component, and examples thereof include a block copolymer composed of a styrene monomer unit and a rubber monomer unit. Examples of the thermoplastic elastomer include polystyrene-polyisoprene-polystyrene (SIS), polystyrene-polybutylene-polystyrene (SBS), polystyrene-poly (ethylene / butylene) block-polystyrene (SEBS), and polystyrene-poly (ethylene / propylene). ) Block-polystyrene (SEPS), polystyrene-polyisoprene (SI), polystyrene-polybutylene (SB), polystyrene-poly (ethylene / propylene) block (SEP), etc., among which SEBS and SEPS are preferred. For example, when SEBS is used, its mass average molecular weight is preferably 20,000 to 500,000, and more preferably 50,000 to 350,000. As a commercially available product of such an elastomer, for example, Clayton G1651 (SEBS type, manufactured by Clayton Polymer) is preferably exemplified.

  Further, the type of the plasticizer constituting the above-mentioned pressure-sensitive adhesive component is not particularly limited, but when the plastic elastomer has a polystyrene phase and a rubber phase, it has a high affinity for the rubber phase, High molecular weight compounds with low affinity are suitable. As such a plasticizer, for example, naphthenic oil or paraffinic oil can be used. In the present invention, either naphthenic oil or paraffinic oil can be used alone, but these can also be used in combination.

  As said naphthenic oil, it is preferable that the flash point is 100-300 degreeC, for example, More preferably, it is 150-280 degreeC. Moreover, it is preferable that the pour point is -30--5 degreeC, for example, More preferably, it is -25--10 degreeC. Moreover, it is preferable that the specific gravity is 0.83-0.87, for example, More preferably, it is 0.837-0.868. And it is preferable that the mass mean molecular weight is 100-1000, More preferably, it is 150-450.

  On the other hand, as the paraffinic oil, for example, its flash point is preferably 100 to 300 ° C, and more preferably 150 to 280 ° C. Moreover, it is preferable that the pour point is -30--5 degreeC, for example, More preferably, it is -25--10 degreeC. Moreover, it is preferable that the specific gravity is 0.89-0.91, for example, More preferably, it is 0.8917-0.9065. And it is preferable that the mass mean molecular weight is 100-1000, More preferably, it is 150-450.

The mixing ratio of the thermoplastic elastomer and the plasticizer is not particularly limited, but is preferably, for example, 10:90 to 90:10, and more preferably 20:80 to 80:20.

Adhesive component In addition to the above-mentioned pressure-sensitive adhesive component, an adhesive component mainly composed of a carboxylic acid-modified thermoplastic elastomer and a crosslinking agent can be blended in the pressure-sensitive adhesive layer. By blending such an adhesive component, there is an effect of improving the adhesiveness of the adhesive layer to the base sheet layer.

  As the carboxylic acid-modified thermoplastic elastomer constituting the adhesive component, various types such as a carboxylic acid-modified styrene thermoplastic elastomer can be used. Here, the carboxylic acid modification includes, for example, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, lauric acid, myristic acid, palmitic acid, stearic acid and other aliphatic saturated monocarboxylic acids and succinic acid. Aliphatic unsaturated dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, aliphatic unsaturated monocarboxylic acids such as acrylic acid, propyrolic acid, methacrylic acid, crotonic acid, isocrotonic acid and oleic acid It may be due to carboxylic acids and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid and mesaconic acid. Aliphatic unsaturated dicarboxylic acid modification is preferred, and maleic acid modification is most preferred.

  Such a carboxylic acid-modified styrene thermoplastic elastomer may be, for example, a hydrogenated carboxylic acid-modified styrene thermoplastic elastomer, for example, a hydrogenated carboxylic acid-modified styrene-butadiene elastomer. Good. An example of this is a hydrogenated maleic acid-modified styrene-butadiene elastomer (maleic acid-modified SEBS elastomer). When a hydrogenated maleic acid-modified styrene-butadiene elastomer is used as the carboxylic acid-modified thermoplastic elastomer, the melt index is, for example, 2.5 to 25 g / 10 minutes under the conditions of 200 ° C. and 5 kg. It is preferable that it is 3-7 g / 10 min.

In addition, when the above-mentioned hydrogenated carboxylic acid-modified thermoplastic elastomer is used, the hydrogenation rate is preferably substantially 100%, but may be less than 100% as long as the effects of the present invention can be obtained. Good. When carboxylic acid-modified SEBS 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. In the present invention, the acid value of the carboxylic acid-modified thermoplastic elastomer is preferably 2 to 10. When the acid value is less than 3, a colorless and transparent film can be obtained. On the other hand, when the acid value is 3 to 10, the film can be yellowish.
Examples of commercially available carboxylic acid-modified thermoplastic elastomers or hydrogenated products thereof include Tuftec M1911, M1913, M1943 (trade names, manufactured by Asahi Kasei Kogyo Co., Ltd.), and FG-1901X ( Product name, Kraton Polymer Co., Ltd.).
Cross-linking agent

  Further, the type of the crosslinking agent constituting the adhesive layer is not particularly limited, and can be appropriately determined in consideration of, for example, the type of the carboxylic acid-modified thermoplastic elastomer. Examples of the crosslinking agent include isocyanate crosslinking agents, aziridine crosslinking agents, oxazoline crosslinking agents, and epoxy crosslinking agents. Specifically, commercially available products include Coronate HL (hexamethylene diisocyanate, HDI, manufactured by Nippon Polyurethane Industry). -TMP adduct), BXX5134 (Aziridine-based cross-linking agent) manufactured by Toyo Ink Co., Ltd., Epocross RPS-1005 (oxazoline-based cross-linking agent) manufactured by Nippon Shokubai Co., Ltd., TETRAD-X, TETRAD-C (both epoxy-based cross-linking agents) manufactured by Mitsubishi Gas Chemical Co., Ltd. Can be mentioned.

When the adhesive component is blended in the pressure-sensitive adhesive layer, the blending ratio of each component constituting the pressure-sensitive adhesive layer is usually 25 to 90% by mass, preferably 40 to 80% by mass for the thermoplastic elastomer. Is usually 24 to 88% by mass, preferably 36 to 72% by mass, and the ratio of the thermoplastic elastomer to the plasticizer is 5:95 to 95: 5 in mass ratio. The carboxylic acid-modified thermoplastic elastomer is 0 to 75% by mass, preferably 20 to 60% by mass, and the crosslinking agent used in combination with this is the mass ratio of the carboxylic acid-modified thermoplastic elastomer and the crosslinking agent. It is usually adjusted to be 100: 1 to 4: 1, preferably 50: 1 to 12: 1.

The pressure-sensitive adhesive layer is prepared by dissolving the pressure-sensitive adhesive component or the pressure-sensitive adhesive component and the adhesive component in a solvent to form a pressure-sensitive adhesive layer coating solution, which is applied to the surface of the base sheet or as described later. When the adhesive layer is interposed between the base material sheet layer and the base material sheet surface, the surface of the adhesive layer previously provided on the surface of the base material sheet, or when producing a sheet-like pressure-sensitive adhesive, has releasability. It is applied to the release treatment surface of the base sheet and dried. The above pressure-sensitive adhesive layer coating solution has other additives such as pigments, dyes, antioxidants, anti-aging agents, fillers, ultraviolet absorbers, antistatic agents, as long as the effects of the present invention are not adversely affected. An agent and / or an anti-electromagnetic wave agent can be included.

  The solvent is not particularly limited as long as it can dissolve both the adhesive component and the pressure-sensitive adhesive component and can be removed by drying. For example, toluene and tetrahydrofuran (THF) can be preferably used. The solid content concentration of the coating solution is usually 10 to 40% by mass. Moreover, although the thickness of said adhesive layer is arbitrary, For example, it is 0.5-100 micrometers normally, Preferably it is 5-75 micrometers, More preferably, it is 15-50 micrometers, More preferably, it is 25-50 micrometers. is there.

As the coating method, known methods can be applied. For example, in addition to a roller coating method, a brush coating method, a spray coating method, and a dip coating method, a die coater, a bar coater, a knife coater, a gravure coater, a Mayer bar, etc. Examples of the coating method using And the drying conditions after application | coating are 30 seconds-2 minutes normally in 80-150 degreeC warm air, Preferably it is 40 seconds-1.5 minutes in 100-130 degreeC warm air.

In the heat-sealable self-adhesive sheet of the present invention, an adhesive layer can be interposed between the adhesive layer and the base sheet layer. By interposing the adhesive layer, it is possible to improve the adhesion between the above-mentioned pressure-sensitive adhesive layer and the base sheet layer, particularly when the adhesive component is not blended in the pressure-sensitive adhesive layer. is there. As a component constituting the adhesive layer, the main component is a carboxylic acid-modified thermoplastic elastomer whose main component is excellently compatible with the component constituting the pressure-sensitive adhesive layer, and a crosslinking agent capable of crosslinking the carboxylic acid-modified thermoplastic elastomer. For example, the adhesive component blended in the pressure-sensitive adhesive layer can be applied. That is, the ratio of the carboxylic acid-modified thermoplastic elastomer and the crosslinking agent is preferably adjusted so that the mass ratio is usually 100: 1 to 4: 1, preferably 50: 1 to 12: 1. . In the adhesive component constituting such an adhesive layer, other additives such as pigments, dyes, antioxidants, anti-aging agents, fillers, ultraviolet absorbers are used as long as the effects of the present invention are not adversely affected. , An antistatic agent and / or an electromagnetic wave preventing agent can be included. Among these, it is preferable to add an antistatic agent. As such an antistatic agent, for example, Elegan 264wax made from NOF can be used, and its content is preferably 0.1 to 3.6% by mass based on the mass of the adhesive layer. Preferably it is 0.6-1.8 mass%. By using the antistatic agent at such a ratio, it is possible to satisfactorily prevent so-called “Yuzuhada” and the danger of ignition due to electricity storage.

  The above adhesive layer can be formed by dissolving the above adhesive component and other additives in a solvent to form an adhesive layer coating solution, which is applied to the surface of the base sheet and dried. The solvent is not limited as long as it can dissolve the adhesive component and can be removed by drying. For example, toluene or THF can be used. The solid content concentration of such a solution is usually 5 to 40% by mass, preferably 10 to 25% by mass. The thickness of the pressure-sensitive adhesive layer is arbitrary, but is, for example, 0.5 to 50 μm, preferably 1 to 15 μm, and practically 2 to 5 μm. Desired results are obtained in terms of cost and anchor properties. As the coating method, known methods can be applied. For example, in addition to a roller coating method, a brush coating method, a spray coating method, and a dip coating method, a die coater, a bar coater, a knife coater, a gravure coater, a Mayer bar, etc. The coating method used is mentioned. And the drying conditions after application | coating are 20 to 60 second normally in 80-150 degreeC warm air, Preferably it is 30 to 50 second in 100-130 degreeC warm air. When this adhesive layer is provided, the pressure-sensitive adhesive layer is formed on this surface.

  The surface of the pressure-sensitive adhesive layer of the heat-sealable self-adhesive sheet obtained as described above is preferably coated with a release layer as necessary for protecting the surface. Examples of the releasable sheet having such a release layer include a PET film having a surface treated with silicone and a paper having a surface treated with silicone, but depending on the degree of adhesiveness of the pressure-sensitive adhesive layer, it may be treated with silicone. It is also possible to coat a polyolefin film such as a polyethylene film, polypropylene film or the like that has not been subjected to the releasability treatment, a fluorine film, a film coated with fluorine and alkyd, or other plastic film.

The sheet-like pressure-sensitive adhesive according to the second aspect of the present invention is obtained by applying the pressure-sensitive adhesive layer coating solution used for the heat-sealable self-adhesive sheet to the release-treated surface of the substrate sheet having releasability and then drying it. And can be obtained by forming a pressure-sensitive adhesive layer.

As the substrate sheet having releasability, those usable for coating the surface of the pressure-sensitive adhesive layer of the heat-sealable self-adhesive sheet can be used. Further, the thickness of the sheet-like pressure-sensitive adhesive is not particularly limited and is appropriately set as necessary. For example, it is 0.5 to 100 μm, preferably 5 to 75 μm, more preferably 15 to 50 μm, Preferably it is 25-50 micrometers.

Moreover, the density | concentration of said adhesive layer coating solution, the coating method, and drying conditions can be performed according to the case of the said heat-sealable self-adhesive sheet. As in the case of the heat-sealable self-adhesive sheet, it is preferable that the exposed adhesive surface of the sheet-like adhesive obtained as described above is coated with a release sheet.

In addition, when the adhesive component is used as a component, the heat-sealable self-adhesive sheet and the sheet-like pressure-sensitive adhesive are aged at 40 to 80 ° C. for 2 to 6 days as necessary after coating and drying. preferable.
Bonding method (effect by heating)

In the present invention, after pasting the heat-sealable self-adhesive sheet on the surface of the adherend or pasting the article via the sheet-like pressure-sensitive adhesive, the part including the pressure-sensitive adhesive layer and the adhesive layer is heated. By doing so, the adhesive strength can be enhanced. Also, the adhesive strength can be enhanced by ultrasonic fusion or ultraviolet irradiation. That is, the above-mentioned heat-sealable self-adhesive sheet and sheet-like pressure-sensitive adhesive usually have low adhesive strength that can be easily peeled off, for example, 0.1 N / cm or less at the time of sticking, and the sticking position shifts. Or, if air bubbles are caught in the bonding interface and re-sticking is required, re-sticking can be performed easily.Once the sticking is confirmed, the part including the pressure-sensitive adhesive layer and the adhesive layer is heated or removed as necessary. The adhesive strength can be reinforced, for example, to 0.5 N / cm or more, preferably 1.0 N / cm or more by irradiation with ultraviolet rays. The above heating conditions are appropriately set depending on the component composition of the pressure-sensitive adhesive layer, the type of adherend material, the desired adhesive strength, etc., and depending on the type of adherend material, for example, 60 ° C. or higher, preferably Is 80 ° C. or higher, more preferably 140 ° C. or higher. Although the heating time depends on the heating temperature, it is usually 1 second or longer, preferably 10 minutes or longer, more preferably 1 hour or longer. The heating temperature, the composition of the pressure-sensitive adhesive layer, and the type of the adherend material Depending on the case, it may be 24 hours to 500 hours or more.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not necessarily limited to these. In addition, various evaluation of the obtained adhesive sheet was performed according to the following evaluation criteria.

(Adhesion strength)
A strip-shaped test piece having a width of 25 mm and a length of 250 mm is cut from the adhesive sheet to be evaluated, and this test piece is placed on the back surface of the base sheet layer through a double-sided adhesive tape having a width of 25 mm (Nichiban Nai stack) and an acrylic plate. (Acrylite L001 manufactured by Mitsubishi Rayon Co., Ltd.), a peeling port is provided between the base material layer and the adhesive layer of the adhesive sheet portion, and the end of the separated adhesive layer is made of AUTOGRAPH AGS-50D manufactured by Shimadzu Corporation. Grasping with a gripping device, and measuring the peel strength at the interface between the base sheet layer and the pressure-sensitive adhesive layer at a peel rate of 50 mm per minute by the peel angle 90-degree method according to the adhesive strength test method of JIS Z 0237, The average value of the measured values of each of the three test pieces was defined as the adhesion strength. In addition, when the adhesive strength was high and the pressure-sensitive adhesive layer broke before peeling at the above-mentioned interface during measurement, it was evaluated as “break”.

(Air removal speed)
It was performed by loop type air loss measurement. The long side of a PET sheet (trade name: Lumirror 125T60, manufactured by Toray Industries, Inc.) having a length of 90 mm and a width of 40 mm and a thickness of 125 μm is rounded into a loop and picked with a fingertip to form a cylinder with a circumference of 90 mm Then, the bottom part (center) is kept in contact with the adhesive sheet to be evaluated spread on the desk while keeping the picked part upside down, and then the picked fingertip is released to make the PET sheet right and left in the length direction. When the adhesive sheet is adhered to the adhesive sheet while excluding air between the adhesive sheet and the left and right parts (45 mm length), the adhesion of the side where all the parts are first adhered to the adhesive layer is completed. Time t (seconds) was measured, and the speed calculated by the formula of 45 mm / t seconds was defined as the air removal speed (cm / second).

(Lamination workability to window glass)
The peelable sheet is peeled off from the heat-sealable self-adhesive sheet, and the exposed pressure-sensitive adhesive layer is attached to one end of the film on the glass plate surface (plane) first, and then gradually applied to the other end. The affixed surface was enlarged and pasted. The workability at that time was evaluated according to the following criteria.
◎: Can be smoothly bonded without biting bubbles ○: Bubbles are slightly bited, but there is no problem in practical use ×: Many bubbles are bitten and difficult to bond

(Adhesive strength of adhesive sheet)
On the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet to be evaluated, a predetermined adherend (acrylic plate / Mitsubishi Rayon Acrylite L001, PET film / 25 μm thick Toler mirror 25T60, or 50 μm thick PEN film / Teijin DuPont film) Teonex Q51, manufactured by Co., Ltd. is bonded to form a laminated sheet, and a strip-shaped test piece having a width of 25 mm and a length of 250 mm is cut from the obtained laminated sheet, and each is separately separated at 25 ° C. and 80 ° C. For the test piece that was allowed to stand for 30 minutes or in an environment of 140 ° C. for 10 minutes and then allowed to cool for 30 minutes or more in an environment of 25 ° C., a peeling opening was formed between the base sheet of the adhesive sheet and the adherend film. The peel strength between the sheet and the film is manufactured by Shimadzu Corporation according to the adhesive strength test method of JIS Z 0237 Using UTOGRAPH AGS-50D, the peel angle of 180 degrees method for each was measured at a peeling rate per minute 300mm conditions to the adhesion strength average values of the measured values of each 3 specimen.

[Example 1]
(Adhesive layer)
SEBS thermoplastic elastomer (Clayton G1651, styrene / (ethylene + butylene) mass ratio 33/67, manufactured by Kraton Polymer Co., Ltd.) 50 parts by mass and plasticizer (naphthene oil (mixture of naphthene oil and paraffin oil), average molecular weight 350, flash point 220 ° C .; pour point −25 ° C .; specific gravity 0.8387) After dissolving 50 parts by mass in 330 parts by mass of toluene to prepare a coating solution for an adhesive layer, this coating solution was used as a base sheet. It is applied on Lumirror 50T60 (manufactured by Toray Industries Inc., untreated PET film) with a thickness of 50 μm in A4 size using a Mayer bar so that the thickness after drying is 35 μm, and dried at 100 ° C. for 1 minute. A pressure-sensitive adhesive layer is formed, and a peelable sheet (the surface of a PET film having a thickness of 75 μm is subjected to silicone treatment on the surface of the pressure-sensitive adhesive layer, trade name: P-PET-03-75-BU, stuck the east Cerro Co., Ltd.) to obtain a heat-sealable self-adhesive sheet of the present invention.
The obtained heat-sealable self-adhesive sheet was evaluated for adhesion strength, air removal speed, bonding workability to window glass, and adhesive strength of the adhesive sheet. It was shown to.

[Example 2]
(Adhesive layer)
Tuftec M1911 (manufactured by Asahi Kasei Kogyo Co., Ltd., maleic acid-modified SEBS, melt index (200 ° C., 5 kg) 3.5 g / 10 min, styrene: ethylene + butylene mass ratio 30:70, acid value 2) 100 parts by mass with toluene Dissolved in 670 parts using a propeller stirrer (solid content 13%). To 100 parts by mass of this solution, 12 parts of Coronate HL (manufactured by Nippon Polyurethane Industry, hexamethylene diisocyanate, HDI-TMP adduct, solid content 75%) were mixed at room temperature to obtain a coating solution for an adhesive layer. This coating solution was applied to the surface of Lumirror 50T60 (untreated PET film, manufactured by Toray Industries, Inc.) having a thickness of 50 μm as a base sheet with a Mayer bar, and dried at 120 ° C. for 40 seconds. An adhesive layer having a thickness of 3 μm was formed.

(Adhesive layer)
The adhesive layer coating solution was applied to the surface of the adhesive layer in the same manner as in Example 1 to form an adhesive layer having a thickness of 35 μm. In the same manner as in the case, a peelable sheet was bonded to obtain a heat-sealable self-adhesive sheet of the present invention.
About the obtained heat-sealable self-adhesive sheet, the adhesion strength, the air removal speed, the bonding workability to the window glass, and the adhesive strength of the adhesive sheet are evaluated, and the main formulation of the adhesive layer is shown in Table 1. Indicated.

[Example 3]
(Adhesive layer)
A coating solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that the oil used as the plasticizer in Example 1 was replaced with paraffinic oil (mass average molecular weight 330), and this coating solution was applied. Then, a pressure-sensitive adhesive layer was formed by drying, and a peelable sheet was bonded to the surface of this pressure-sensitive adhesive layer in the same manner as in Example 1 to obtain a heat-sealable self-adhesive sheet of the present invention.
The obtained heat-sealable self-adhesive sheet was evaluated for adhesion strength, air removal speed, bonding workability to window glass, and adhesive strength of the adhesive sheet. It was shown to.

[Example 4]
(Adhesive layer)
SEBS thermoplastic elastomer (Clayton G1651, styrene / (ethylene + butylene) mass ratio 33/67, manufactured by Kraton Polymer) 50 parts by mass and plasticizer (paraffinic oil, mass average molecular weight 330) 50 parts by mass toluene 274 mass Furthermore, Tuftec M1911 (melt index 3.5 g / 10 min, styrene: ethylene + butylene mass ratio 30:70, acid value 2, Asahi Kasei Kogyo Co., Ltd.) is maleic acid-modified SEBS as an adhesive component. 50 parts by mass and 6 parts by mass of Coronate HL were mixed and stirred well to obtain a coating solution for the pressure-sensitive adhesive layer, and then this coating solution was used as a base sheet for A4 plate size and 50 μm thick Lumirror 50T60 (Untreated PET film, manufactured by Toray Industries, Inc.) The thickness after drying using a Mayer bar on the surface is 35 μm m, and dried at 100 ° C. for 1 minute to form an adhesive layer. A peelable sheet was bonded to the surface of the adhesive layer in the same manner as in Example 1. This was aged at 45 ° C. for 4 days to obtain a heat-sealable self-adhesive sheet of the present invention.
The obtained heat-sealable self-adhesive sheet was evaluated for adhesion strength, air removal speed, bonding workability to window glass, and adhesive strength of the adhesive sheet. It was shown to.

[Example 5]
30 parts by mass of SEPS thermoplastic elastomer (Clayton G1651, styrene / (ethylene + butylene) mass ratio 33/67, manufactured by Kraton) and 70 parts by mass of plasticizer (paraffinic oil, mass average molecular weight 330) are 274 parts by mass of toluene. In addition, as an adhesive component, Tuftec M1911 which is maleic acid-modified SEBS (melt index is 3.5 g / 10 min, styrene: ethylene + butylene mass ratio is 30:70, acid value is 2, Asahi Kasei Kogyo Co., Ltd.) (Made) 15 parts by mass and 0.7 parts by mass of Coronate HL are mixed and stirred well to form a coating solution for the pressure-sensitive adhesive layer. The coating solution is a large A4 plate having a thickness of 50 μm as a base sheet. Lumirror 50T60 (manufactured by Toray Industries, Inc., untreated PET) The surface after drying using a Mayer bar will be 35 μm Then, the pressure-sensitive adhesive layer was formed by drying at 100 ° C. for 1 minute, and a peelable sheet was bonded to the surface of the pressure-sensitive adhesive layer in the same manner as in Example 1. This was aged at 45 ° C. for 4 days to obtain a heat-sealable self-adhesive sheet of the present invention.
The obtained heat-sealable self-adhesive sheet was evaluated for adhesion strength, air removal speed, bonding workability to window glass, and adhesive strength of the adhesive sheet. It was shown to.

[Example 6]
In Example 5, a sample was prepared in the same manner as in Example 5 except that the thickness of the pressure-sensitive adhesive layer after drying was changed to 1 μm using a Mayer bar, and the obtained heat-sealable self-adhesive sheet was subjected to adhesion strength and air release speed. The results are shown in Table 1, together with the main prescription of the pressure-sensitive adhesive layer, by evaluating the workability of bonding to the window glass and the adhesive strength of the pressure-sensitive adhesive sheet.

[Example 7]
In Example 5, as an adhesive component, 15 parts by mass of maleic acid-modified SEBS Tuftec M1911), 3.74 parts by mass of an isocyanate curing agent Coronate HL and an aziridine curing agent BXX5134 (aziridine curing agent, Except that Toyo Ink Manufacturing Co., Ltd.) was changed to 0.03 parts by mass, the coating solution for the pressure-sensitive adhesive layer was obtained in the same manner as in Example 5, and the coating solution for the pressure-sensitive adhesive layer was the same group. The heat-sealable self-adhesive sheet of the present invention was obtained by applying to a material sheet, drying and aging.
The obtained heat-sealable self-adhesive sheet was evaluated for adhesion strength, air removal speed, bonding workability to window glass, and adhesive strength of the adhesive sheet. It was shown to.

[Example 8]
A release sheet for the pressure-sensitive adhesive layer coating solution obtained in Example 4 (silicone-treated surface of 75 μm thick PET film, trade name: SP-PET-01-75-BU, manufactured by Tosero Corporation) The release layer was coated with a Mayer bar so that the thickness after drying was 35 μm, and dried at 100 ° C. for 1 minute to form a pressure-sensitive adhesive layer. Example 1 was formed on the pressure-sensitive adhesive layer surface. In the same manner as in the above, the same release sheet was laminated, and this was aged at 45 ° C. for 4 days to obtain the sheet-like pressure-sensitive adhesive of the present invention having both surfaces coated with the release sheet.
The release sheet on one side of the sheet-like pressure-sensitive adhesive was peeled off, and the exposed pressure-sensitive adhesive surface was bonded to a 50 μm-thick PEN film / Teonex Q51 manufactured by Teijin DuPont Films, Inc. at 100 ° C. The heat-sealable self-adhesive sheet which used the PEN film as the base material sheet was obtained by heating for * 0.5 hour.

[Comparative Example 1]
SK Dyne 1499 (manufactured by Soken Chemical Co., Ltd., acrylic pressure-sensitive adhesive, solid content 30%) 100 parts by mass L-45 (manufactured by Soken Chemical Co., Ltd., isocyanate curing agent, solid content 45%) 5.4 parts (nonvolatile content ratio) 100: 8) was mixed at room temperature and stirred well to obtain a coating solution for the pressure-sensitive adhesive layer. The coating solution for pressure-sensitive adhesive layers was applied to the same substrate sheet in the same manner as in Example 1. Then, this was dried and aged at 45 ° C. for 4 days to obtain an adhesive sheet.
About the obtained heat-sealable self-adhesive sheet, the adhesion strength, the air removal speed, the bonding workability to the window glass, and the adhesive strength to the PET film were evaluated, and together with the main formulation of the pressure-sensitive adhesive layer, in Table 1. Indicated.

(Summary of results)
As is clear from the results in Table 1, the heat-sealable self-adhesive sheet of the present invention prepared according to the examples has a faster air release speed than that of the conventional low-strength acrylic adhesive. Now, the bonding workability to the window glass is excellent, the adhesive strength at the time of bonding to the acrylic resin plate, the PET film and the PEN film is small, and re-bonding is easy. And once sticking is decided, adhesive strength can be remarkably enhanced by heat treatment.

The heat-sealable self-adhesive sheet of the present invention is formed by forming a self-adhesive pressure-sensitive adhesive layer containing a thermoplastic elastomer and a plasticizer on the surface of a base material sheet. Due to the self-adhesiveness of the force, there are few entrainment of bubbles on the adhesive surface, and in the unlikely event that bubbles are involved or the application position is misaligned, it can be easily peeled off and reattached, and to the adherend surface Since there is no adhesive residue, it is possible to avoid adhesion surface contamination and component loss due to re-sticking, and after bonding is confirmed at a predetermined position, the adhesive strength is significantly improved by heat treatment. Since it can be strengthened, it can be used as an adhesive with little loss, and a sheet-like pressure-sensitive adhesive obtained by forming the above-mentioned pressure-sensitive adhesive layer on a releasable substrate sheet is used as an adhesion target. Base material Easily can be obtained heat-sealable self-adhesive sheet Extemporaneous by transferring the over bets, the effect on the industry is large.

Claims (13)

A heat-sealable self-adhesive sheet comprising a base material sheet and a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive component containing a thermoplastic elastomer and a plasticizer. The heat-sealable self-adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains a pressure-sensitive adhesive component, and further an adhesive component containing a carboxylic acid-modified thermoplastic elastomer and a crosslinking agent. The heat-sealable self-adhesive sheet according to claim 1 or 2, wherein an adhesive layer comprising an adhesive component is interposed between the base sheet layer and the adhesive layer. The heat-sealable self-adhesive sheet according to claim 3, wherein an antistatic agent is further blended in the adhesive component of the adhesive layer. The heat-sealable self-adhesive sheet according to any one of claims 1 to 4, wherein the thermoplastic elastomer is a block copolymer comprising a styrene monomer unit and a rubber monomer unit. The heat-sealable self-adhesive sheet according to any one of claims 1 to 5, wherein the plasticizer is naphthenic oil, paraffinic oil, or a combination thereof. The heat-sealable self-adhesive sheet according to any one of claims 1 to 6, wherein the plasticizer has a mass average molecular weight of 100 to 1,000. The heat sealing property according to any one of claims 2 to 7, wherein the adhesive component contains a carboxylic acid-modified thermoplastic elastomer and a crosslinking agent in a mass ratio of 100: 1 to 4: 1. Self-adhesive sheet. The heat-sealable self-adhesive sheet according to any one of claims 2 to 8, wherein the crosslinking agent is isocyanate-based or imine-based. The heat-sealable self-adhesive sheet according to any one of claims 1 to 9, wherein the base sheet is a plastic film. The same pressure-sensitive adhesive layer as that of the heat-sealable self-adhesive sheet according to any one of claims 1 to 9 is formed on a release treatment surface of a base sheet having releasability. Sheet adhesive. The heat-sealable self-adhesive sheet according to any one of claims 1 to 11, wherein the exposed surface of the pressure-sensitive adhesive layer is coated with a release sheet. The sheet-like pressure-sensitive adhesive according to claim 11, wherein the heat-sealable self-adhesive sheet according to any one of claims 1 to 10 and 12 from which the release sheet is peeled off is attached to the surface of the adherend. A method for adhering a base sheet or an article, comprising: attaching an article via a step, and heating a portion including the adhesive layer and the pressure-sensitive adhesive layer to enhance the adhesive strength.