JP2007023057A - Combinedly used crosslinking agent type self-adhesive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightly removable self-adhesive film excellent in transparency, adhesion between an adhesive layer and a substrate film layer, an air-removing property from interface when attaching to an adherend and stability of adhesive force to the adherend with time. <P>SOLUTION: In the self-adhesive film obtained by laminating an adhesive layer containing a carboxylic acid-unmodified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer and a crosslinking agent to a substrate film surface, a high temperature-reactive crosslinking agent and a low temperature-reactive crosslinking agent are combinedly used as the crosslinking agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is applied to various shapes such as flat surfaces, curved surfaces, and uneven surfaces composed of various materials such as plastics, metals and fibers, as well as glass screens such as display screens for TVs, personal computers and mobile phones, and window glass. The present invention relates to a self-adhesive film useful for protecting or shielding a surface from impacts and scratches, or as a POP advertisement or bar code label, when it is repeatedly applied and peeled off.

  Conventionally, there has been a demand for a film that can be suitably used to efficiently coat a surface that requires protection or light shielding. For example, it has a low dependency on the pressing force at the time of application, and can be easily attached (temporarily attached) to the surface of various materials (protected bodies) including metal plates even when it is pressed at a low pressure. A surface protective film excellent in removability has been proposed (see, for example, Patent Document 1).

  In addition, 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 have been proposed (for example, Patent Documents). 2).

  In addition, surface protection with a pressure-sensitive adhesive layer on a substrate that has good adhesiveness at the time of bonding, has very little change over time in adhesive strength after bonding, and has practical weather resistance. A material has been proposed (see, for example, Patent Document 3).

  Further, 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).

  Furthermore, 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, the transparency of the surface to be protected is often required, and the adhesiveness to the surface to be protected (adhesive strength and ease of bonding) is often required. The resistance to external loads (for example, scratching and peeling) is regarded as important.

  Also, in general, a usage mode in which an adhesive film obtained by laminating an adhesive layer on a base film on which advertising characters and / or designs are drawn is attached to an adherend surface such as glass at various stores is proposed. However, in this case, if you try to peel off to change the layout of the pasting, the adhesive layer will remain on the adherend surface when peeling, and it will be necessary to wipe and clean it, which will not only take time Adhesiveness for attaching was lowered, and it was difficult to repeatedly apply to the adherend surface.

Furthermore, the adherend surface is generally a flat surface in many cases, but especially when it has a curved shape, it cannot be removed when air enters between the adherend surface when the film is attached, Since unevenness occurs on the pasting surface, there are many problems in terms of appearance and durability. Further, in order to improve workability, a film having good air detachability (property that air bubbles are not caught between a sticking surface (hereinafter referred to as an adherend surface) when sticking) is desired.
JP 2001-139898 A JP 2001-348561 A JP-A-8-245938 JP-A-8-81616

  Based on the background as described above, the present inventors have self-adhesive in which a pressure-sensitive adhesive layer containing a carboxylic acid-modified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer and a crosslinking agent is laminated on the surface of the base film. Various films have been studied. As the self-adhesive film, there is a demand for the property that air bubbles are not involved in the interface with the adherend, that is, the air release property. In order to improve this, a carboxylic acid-unmodified thermoplastic elastomer and a carboxylic acid-modified heat are required. While considering the amount of plasticizer to be added to the resin component combined with the plastic elastomer, increasing the amount of plasticizer improves the air release, but on the other hand, between the base film and the adhesive layer It has been found that there is a drawback that the adhesive strength of the pressure-sensitive adhesive layer increases with time when the adhesiveness decreases and the amount of the crosslinking agent is increased in order to improve it.

  That is, in the present invention, even when the adherend surface is composed of various materials, for example, plastic, metal, fiber, glass, and the like, and has various shapes such as a flat surface, a curved surface, and an uneven surface. Another object of the present invention is to provide a self-adhesive film that is excellent in transparency, has excellent air detachability during application, has excellent adhesion stability after application, and can be easily peeled off.

  The present invention provides a self-adhesive film in which a pressure-sensitive adhesive layer containing a carboxylic acid-unmodified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer, and a cross-linking agent is laminated on the surface of a substrate film. A high temperature reactive crosslinking agent and a low temperature reactive crosslinking agent are used in combination.

  The self-adhesive film of the present invention is basically self-adhesive and is applied in various shapes such as flat surfaces, curved surfaces, and uneven surfaces made of various materials such as plastic, metal, fiber, and glass. Excellent air repellency and transparency when affixed to the surface, and high adhesion between the base film and the adhesive layer that make up the self-adhesive film. In addition, there is little peeling of the resin, and the adhesive strength after aging is stable and peeling from the adherend surface is easy.

  The term “self-adhesive” in the present invention means a property that allows adhesion without applying pressure from the outside when affixing to an adherend surface.

  The self-adhesive film of the present invention is formed by laminating an adhesive layer on the substrate film surface.

  It does not specifically limit as a material which comprises said base film, The base material conventionally used as a self-adhesive film or a surface protection film can be used, For example, a plastic film is illustrated suitably. Is done. As such a base material, for example, a polyester resin such as polyethylene terephthalate (PET) or polybutylene terephthalate, a film such as polyolefin, polyamide, polycarbonate, acrylic resin, or polyvinyl chloride, and other papers can be used. . The above-mentioned base film 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. Agents, anti-electromagnetic wave agents, and combinations thereof.

  The thickness of the base film can be appropriately determined in consideration of the durability and flexibility required for the self-adhesive film as a product, and is, for example, 10 to 350 μm, preferably 25 to 200 μm. is there. In addition, although said base film is normally colorless and transparent, it may be colored transparent or opaque according to the use of the self-adhesive film which is a product.

  The pressure-sensitive adhesive used in the self-adhesive film of the present invention is suitable for imparting the preferable property of self-adhesiveness, but in order to make use of this self-adhesiveness, a pressure-sensitive adhesive layer was laminated thereon as a base film. When, for example, sticking one end of the adhesive film on the adherend surface and releasing the fingertip holding the other end, the sticking is sequentially advanced toward the other end to complete the sticking. It is particularly preferred to select a base film that is flexible and flexible so that it is possible. From this viewpoint, for example, a PET film can be suitably used. Examples of such commercially available PET films include Lumirror 75T60 manufactured by Toray Industries, Inc. and Emblet 38SC manufactured by Unitika.

  The above-mentioned base film is preferably used on one or both sides thereof, if necessary, with easy adhesion treatment, for example, corona treatment, plasma treatment, blast treatment, etc. Can do.

  The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is constituted by dissolving a carboxylic acid-unmodified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer, and a crosslinking agent in a solvent.

  As the above-mentioned carboxylic acid-unmodified thermoplastic elastomer, various types can be used, but a polymer composed of a block segment composed of a styrene monomer unit and a rubber monomer unit is preferable. Examples of such a polymer include SIS, SBS, SEBS, SEPS, SI, SB, and SEP. Among them, SEBS and SEPS are preferable. When using said SEBS, it is preferable that the mass mean molecular weight is 20,000-500,000, for example, More preferably, it is 50,000-350,000. The carboxylic acid-unmodified thermoplastic elastomer is usually 5 to 50% by mass, preferably 15 to 30% by mass, based on the mass of the pressure-sensitive adhesive layer.

  In addition, as the carboxylic acid-modified thermoplastic elastomer, various ones such as a carboxylic acid-modified styrene thermoplastic elastomer can be used, for example, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalate. Aliphatic saturated monocarboxylic acids such as acid, lauric acid, myristic acid, palmitic acid and stearic acid, aliphatic saturated dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, Modified with aliphatic unsaturated monocarboxylic acids such as acrylic acid, propyrolic acid, methacrylic acid, crotonic acid, isocrotonic acid and oleic acid, and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid and mesaconic acid Can be mentioned. Among them, those modified with aliphatic unsaturated dicarboxylic acid modification are preferable, and maleic acid modification is most preferable.

  The carboxylic acid-modified styrene thermoplastic elastomer may be, for example, a hydrogenated carboxylic acid-modified styrene thermoplastic elastomer, or may be, for example, a hydrogenated carboxylic acid-modified styrene-butadiene elastomer. . 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. Some are preferred, more preferably 3-7 g / 10 min.

  Further, when the above-mentioned 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. . 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 include Toughtech M1911, M1913, M1943 manufactured by Asahi Kasei Kogyo Co., Ltd., and Kraton FG-1901X manufactured by Kraton Polymer.

  The amount of the carboxylic acid-modified thermoplastic elastomer added is usually 5 to 65% by mass and practically 10 to 40% by mass in the total mass of the pressure-sensitive adhesive layer.

Moreover, as said crosslinking agent, in this invention, a low temperature reactive crosslinking agent and a high temperature reactive crosslinking agent are used together, It is characterized by the above-mentioned. Examples of such low-temperature reactive cross-linking agents include isocyanate-based cross-linking agents, and examples of high-temperature reactive cross-linking agents include aziridine-based cross-linking agents and oxazoline-based. The above-mentioned high temperature reactive cross-linking agent refers to a cross-linking agent that hardly undergoes a cross-linking reaction at a relatively low temperature, for example, below 60 ° C., and the above low-temperature reactive cross-linking agent is at a relatively low temperature, for example, below 60 ° C. It refers to a cross-linking agent that undergoes a cross-linking reaction to some degree of practicality.

As a commercial item of said isocyanate type crosslinking agent, Coronate HL (Hexamethylene diisocyanate HDI-TMP adduct) by Nippon Polyurethane Industry Co., Ltd. can be used conveniently, for example.

As a commercial item as said polyfunctional aziridine type crosslinking agent, BXX5134 (Aziridine type hardening | curing agent, the Toyo Ink Manufacturing Co., Ltd. product) can be used conveniently, for example.

  Moreover, although the addition amount of said crosslinking agent changes with kinds of crosslinking agent, in the case of a low temperature reactive crosslinking agent with respect to 100 mass parts of carboxylic acid modified thermoplastic elastomer in an adhesive layer, it is 0 normally. 8 to 6 parts by mass, preferably 0.9 to 5 parts by mass, and in the case of a high-temperature reactive crosslinking agent, the amount is usually 0.8 to 4 parts by mass, preferably 0.9 to 3. 5 parts by mass.

  When the addition amount of the low-temperature reactive crosslinking agent is less than 0.8 parts by mass, the adhesiveness of the pressure-sensitive adhesive layer to the base film tends to be insufficient. If it exceeds 6.0 parts by mass, the peelability after heat treatment with respect to the PET film tends to decrease. Moreover, if the addition amount of the high-temperature reactive crosslinking agent is less than 0.8 parts by mass, the adhesiveness of the adhesive layer to the substrate film tends to be insufficient, and if it exceeds 4.0 parts by mass, the increase in adhesive strength with time is large. And peeling after use tends to be heavy.

  Further, the type of the plasticizer is not particularly limited, but when the carboxylic acid-unmodified thermoplastic elastomer has a polystyrene phase and a rubber phase, the affinity for the rubber phase is high and the affinity for the polystyrene phase is low. Molecular weight compounds are suitable. Examples of such plasticizers include naphthenic oil and paraffin oil.

  For example, the naphthenic oil has a flash point of 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 0.83-0.87, for example, More preferably, it is 0.837-0.868. Moreover, it is preferable that the mass mean molecular weight is 100-1000, More preferably, it is 150-450.

  On the other hand, as for said paraffin 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 0.89-0.91, for example, More preferably, it is 0.8917-0.9065. Moreover, it is preferable that the mass mean molecular weight is 100-1000, More preferably, it is 150-450. In the present invention, either the naphthenic oil or paraffin oil can be used alone, but these can also be used in combination.

  The amount of the plasticizer added is usually 30 to 80% by mass in the pressure-sensitive adhesive layer, and preferably 40 to 70% by mass from the viewpoint of air release at the time of sticking.

  The carboxylic acid-unmodified thermoplastic elastomer, carboxylic acid-modified thermoplastic elastomer, plasticizer, and crosslinking agent are usually dissolved in a solvent such as toluene to form a pressure-sensitive adhesive solution. The solid content concentration of the pressure-sensitive adhesive solution is usually 20 to 40% by mass.

  In the above adhesive solution, other additives such as pigments, dyes, antioxidants, anti-aging agents, fillers, ultraviolet absorbers, antistatic agents are used as long as the effects of the present invention are not adversely affected. Agent, anti-electromagnetic wave agent, and a combination thereof.

  As said antistatic agent, for example, Elegan 264wax made from NOF can be used, and the content thereof is usually 0.1 to 3.6% by mass, preferably based on the mass of the pressure-sensitive adhesive layer. Is 0.6-1.8 mass%. By using the antistatic agent at such a ratio, so-called “Yuzuhada” can be satisfactorily prevented.

  As said ultraviolet absorber, a benzotriazole type ultraviolet absorber, a benzophenone type ultraviolet absorber, and a triazine type ultraviolet absorber are mentioned.

Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2 -(2'-hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) Examples thereof include benzotriazole and 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole.

Examples of the benzophenone ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, Examples include 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone.

  The amount of the ultraviolet absorber added to the pressure-sensitive adhesive is not particularly limited, but is usually 0.1 to 10% by mass, preferably 0.5 to 5% by mass.

  The self-adhesive film of the present invention is produced by applying the above-mentioned pressure-sensitive adhesive solution to the surface of the base film and drying it. In the case where the above base film is subjected to easy adhesion treatment, it is usually applied to the surface subjected to easy adhesion treatment. The coating method is not particularly limited as long as it can be applied in a liquid form. For example, in addition to a roller coating method, a brush coating method, a spray coating method, a dip coating method, a die coater, a bar coater, a blade Examples include a method using a coater, knife coater, or comma coater. The coating amount is not particularly limited, but is usually 1 to 100 μm, preferably 5 to 75 μm, and practically 15 to 50 μm as the thickness after drying. Thereby, for example, desired results can be obtained in terms of cost and workability.

  The drying conditions may vary depending on the film thickness, the type of solvent selected, and the like, but can be set, for example, at 80 to 150 ° C. for 20 to 180 seconds, preferably at 100 to 130 ° C. for 30 to 150 seconds. To do. Thereby, the adhesive layer which has a thickness of 1-100 micrometers can be provided on a base film. Next, if necessary, a release layer described later is provided on the pressure-sensitive adhesive layer material. Then, the self-adhesive film of this invention can be obtained by making this age at 40-80 degreeC for 2 to 6 days.

  In the present invention, a release layer can be coated on the pressure-sensitive adhesive layer as necessary for the convenience of storage and transportation of the obtained self-adhesive film. In that case, the release layer is peeled off when the self-adhesive film is used, and the pressure-sensitive adhesive layer surface is exposed and used. As a material constituting such a release layer, for example, a silicone-treated PET film, a silicone-treated paper or the like can be used, and among these, a silicone-treated PET film is practical. At that time, the silicone-treated surface is brought into contact with the pressure-sensitive adhesive layer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these. In addition, in the present Example, evaluation of the characteristic of the obtained self-adhesive film was based on the following method.

(Air escape speed): Evaluated by the loop type air escape measurement shown below.
A self-adhesive film with a size of 90 mm x 40 mm is rolled so that the adhesive layer is on the outside, forming a loop in the direction of its long side, and pinched so that both end faces are adjacent to each other. After the side of the side (4.5 cm on one side) is brought into contact with the soda glass surface, the knob is released to release the loop, and the air at the interface between the adhesive side of the self-adhesive film and the glass surface The time t (seconds) until all the pressure-sensitive adhesive surfaces (4.5 cm on one side) of the self-adhesive film contact with the soda glass surface was measured while being pushed out, and the pasting progressed for 1 second calculated by 4.5 / t. The distance to be used was defined as air removal speed, and 3 cm / second or more was considered good.

(Adhesion to substrate: Cutter tear test)
When the release layer is peeled off from the A4 size self-adhesive film, held vertically and pulled from both ends in the width direction, the knife is pulled from the back (the side without the adhesive layer) from the center. Make a cut with. At that time, the length of the maximum peeled portion from the cut portion in the width direction of the film surface portion where the pressure-sensitive adhesive layer was pushed by the blade edge from the base film surface in the cut portion cross section was measured in units of 0.5 mm. The average value of the measured values of the test pieces was defined as adhesion to the substrate, and the length was 2.0 mm or less.

(Peelability after heat treatment applied to PET film: hereinafter abbreviated as peelability after heat treatment with PET film)
A4 size self-adhesive film is cut into a width of 25 mm and a length of 200 mm to form a test piece, and the release layer is peeled off, and this is applied to the surface of Lumirror 25T60 (polyester film, manufactured by Toray Industries, Inc.) with a thickness of 25 μm. After attaching, this is heat-processed for 30 minutes in a thermostat with a temperature of 80 ° C., and then cooled to room temperature. This test piece is AUTOGRAPH
Using AGS-50D (manufactured by Shimadzu Corporation), Lumirror 25T60 was peeled off at a peeling angle of 180 ° and a peeling speed of 300 mm / min, and the adhesive strength between the adhesive layer and the PET film surface was measured. The measured value of each of the three test pieces was converted to N / cm, and the average value was defined as peelability after heat treatment with respect to the PET film, and 0.50 N / cm or less was considered good.

(Peelability after aging pasted on window glass: hereinafter abbreviated as peelability after aging for window glass)
The peeling layer is peeled off from the A4 size self-adhesive film, and the exposed adhesive layer is pasted on the indoor side surface (plane) of the window glass facing the outdoors. Ease of evaluation was evaluated according to the following criteria.
A: Adhesive tape: Nitto 31B (manufactured by Nitto Denko Corporation) is applied to the back surface (base film surface) of the self-adhesive film. Is peeled off.
○: Cannot be peeled off by pulling the part where the above adhesive tape is not attached, but can be peeled without causing distortion by directly pulling and pulling the edge of the self-adhesive film with a fingertip.
Δ: When picked and pulled directly with a fingertip as described above, it can be peeled off, but the response is heavy, the film surface is distorted, and the distortion remains slightly after peeling.
X: When picked and pulled directly with a fingertip as described above, it can be peeled off, but the response is very heavy, the film surface is distorted, and the distortion remains remarkably after peeling.

(Peelability after PC display surface pasting time: hereinafter abbreviated as PC display surface time-lapse peelability)
A self-adhesive film with a width of 25 mm and a length of 200 mm is pasted on a liquid crystal display surface of a personal computer display (manufactured by Sharp Corporation, using LLT153A type), and left for 100 hours at room temperature. AUTOGRAPH in the state
Using AGS-50D (manufactured by Shimadzu Corporation), peeling was performed at a peeling angle of 180 ° and a peeling speed of 300 mm / min, and the adhesive strength and the adhesive strength between the layers on the display surface were measured. The measured value of each of the three test pieces was converted to N / cm, and the average value was regarded as peelability after aging on the PC display surface, and 0.05 N / cm or less was considered good.

Example 1
25.3 parts by mass of SEBS thermoplastic elastomer (mass average molecular weight 200,000) and 59 parts by mass of paraffin oil plasticizer (mass average molecular weight 330) were previously kneaded well and then dissolved in 100 parts by mass of toluene. To this solution, 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] in advance 79 parts by mass of a solution prepared in 16% by mass dissolved in toluene, Coronate HL liquid [Hexamethylene diisocyanate-HDI-TMP adduct, 75% by mass solution manufactured by Nippon Polyurethane Industry] 0.28 parts by mass, BXX5134 liquid [Toyo Ink Manufacturing Co., Ltd. Co., Ltd., aziridine-based curing agent, 5% by mass solution] 4.2 parts by mass, Tinuvin 384-2 (Ciba Geigy, UV absorber, 95% by mass solution) 2.66 parts by mass, and Elegan 264wax [Japan Oil and fat, cationic antistatic agent, solid content 100%] 0.21 part by mass is added and mixed, and adhesive coating solution And the.
This coating solution was applied to a substrate film A4 plate size Lumirror 75T60 [untreated PET film manufactured by Toray Industries, Inc.] using a blade so that the thickness after drying would be 35 μm. An agent layer was formed, dried at 100 ° C. for 2 minutes, and then a silicone-treated PET film as a release layer was bonded to the surface of the formed adhesive layer. This was aged at 45 ° C. for 4 days to obtain a self-adhesive film coated with a release layer.
About the obtained self-adhesive film, each characteristic of air release speed, adhesion to substrate, peeling property after heat treatment to PET film, peeling property after aging for window glass, peeling property after aging for PC display surface was measured. The main composition of the pressure-sensitive adhesive layer (based on pure content) is shown in Table 1.

Example 2
In Example 1, the self-adhesive film which coat | covered the mold release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.4 mass part and BXX5134 liquid to 2.4 mass parts. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Example 3
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.8 mass part and changing BXX5134 liquid into 4.8 mass parts. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Example 4
In Example 1, the self-adhesive film which coat | covered the mold release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.16 mass part and changing BXX5134 liquid into 6.0 mass parts. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Example 5
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.56 mass part and changing BXX5134 liquid into 8.4 mass parts. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Comparative Example 1
In Example 1, a self-adhesive film coated with a release layer was obtained in the same manner as in Example 1 except that the coronate HL solution was changed to 0.2 parts by mass and the BXX5134 solution was changed to 1.2 parts by mass. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Comparative Example 2
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.56 mass part and not using BXX5134 liquid at all. About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main composition of the adhesive layer.

Comparative Example 3
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except having changed the coronate HL liquid into 0.32 mass part and changing BXX5134 liquid into 12 mass parts. About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Comparative Example 4
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except not using coronate HL liquid at all and having changed BXX5134 liquid into 8.4 mass parts. About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main compositions (pure part base) of an adhesive layer.

Comparative Example 5
In Example 1, the self-adhesive film which coat | covered the release layer was obtained like Example 1 except having changed the coronate HL liquid into 1.12 mass parts and changing BXX5134 liquid into 4.8 mass parts. . About the obtained self-adhesive film, each characteristic was measured like the case of Example 1, and it described in Table 1 with the main composition of the adhesive layer.

(Discussion)
As is clear from the results described in Table 1 above, a low-temperature reactive cross-linking agent and a high-temperature reactive cross-linking agent are each predetermined as a cross-linking agent (curing agent) added to the pressure-sensitive adhesive layer, which is a feature of the present invention. In combination with the above range, all the properties of adhesion to substrate, releasability after heat treatment with PET film, releasability after window glass aging, and releasability after aging of PC display surface are maintained while maintaining the air release speed. It can be seen that it has excellent performance.

In the self-adhesive film of the present invention, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer contains a carboxylic acid-unmodified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer, and a cross-linking agent. By combining the use of an adhesive crosslinker and a low-temperature reactive crosslinker, both transparency, adhesion between the adhesive layer and the base film layer, and air release from the interface when applied to the adherend are excellent. In addition, the adhesive strength after pasting to various adherends is stable, and the peelability from the adherend after aging is improved and it does not damage the adherend. It can be used and its industrial effect is great.

Claims (10)

  High-temperature reactive crosslinking as a crosslinking agent in a self-adhesive film in which an adhesive layer containing a carboxylic acid-modified thermoplastic elastomer, a carboxylic acid-modified thermoplastic elastomer, a plasticizer, and a crosslinking agent is laminated on the substrate film surface A self-adhesive film characterized in that an agent and a low-temperature reactive crosslinking agent are used in combination.   The self-adhesive film according to claim 1, wherein the low-temperature reactive cross-linking agent is an isocyanate-based cross-linking agent.   The self-adhesive film according to claim 1 or 2, wherein the high-temperature reactive crosslinking agent is an aziridine-based crosslinking agent.   The self-adhesive film according to any one of claims 1 to 3, wherein the carboxylic acid-unmodified thermoplastic elastomer comprises a block segment composed of a styrene monomer unit and a rubber monomer unit.   The self-adhesive film according to any one of claims 1 to 4, wherein the plasticizer comprises naphthenic oil and / or paraffin oil having a mass average molecular weight of 100 to 1000.   The self-adhesive film according to any one of claims 1 to 5, wherein the addition amount of the plasticizer in the total pressure-sensitive adhesive layer is 30 to 80% by mass.   The low-temperature reactive crosslinking agent is added in an amount of 0.8 to 6.0 parts by mass with respect to 100 parts by mass of the carboxylic acid-modified thermoplastic elastomer. Self-adhesive film.   The high-temperature reactive crosslinking agent is added in an amount of 0.8 to 4.0 parts by mass with respect to 100 parts by mass of the carboxylic acid-modified thermoplastic elastomer, according to any one of claims 1 to 7. Self-adhesive film.   The self-adhesive film according to any one of claims 1 to 8, wherein the base film is a plastic film. The self-adhesive film according to any one of claims 1 to 9, wherein a release layer is provided on the pressure-sensitive adhesive layer.