JP6100539B2 - Adhesive cleaner for organic dirt removal - Google Patents

Description

  The present invention relates to an adhesive cleaner used to remove organic soils. More specifically, the present invention relates to an adhesive cleaner used to remove sebum and other organic dirt from a flat surface (for example, a touch panel display / input surface) of a portable device such as a tablet information terminal or a smartphone.

  Typical for portable devices such as portable PCs such as notebook computers (PCs), tablet information terminals such as electronic books, mobile phones such as smartphones, portable game machines, and portable terminals such as various PDAs (personal digital assistants). Specifically, a display unit (display) made of a liquid crystal panel or an organic EL panel is provided on a flat surface. Since such portable devices are used by carrying them on a daily basis, organic dirt such as dust, dirt, cosmetics and sebum tends to adhere to them. In particular, touch-panel portable devices, which have become very popular in recent years, are operated by the user touching the display unit / input unit, which also functions as the input unit, with their fingertips. Easy to adhere. Moreover, not only those portable devices but also show window glasses, glass tables, showcases and the like have a flat surface, and when the organic dirt adheres to the surface, the appearance deteriorates and is unsightly.

  Paper, woven fabric, or non-woven cloth is used as a means for removing the organic dirt adhering to the display surface. However, wiping off dirt with waste, for example, when the dirt contains oil components such as sebum, there is a risk of spreading the dirt depending on how it is wiped, or it may be necessary to wipe it multiple times, so it is not always easy to use I can't say that. Moreover, since dirt accumulates gradually by continuous use, it is necessary to periodically clean or replace it with a new one, which is troublesome. Alternatively, there is a means for removing organic contaminants by wiping the surface with a suitable cleaning agent contained in a suitable material (for example, sponge or gauze) (see, for example, Patent Document 1). However, care should be taken in handling the cleaning agent, and the surface may be affected by the remaining cleaning agent. Therefore, it is necessary to remove the cleaning agent, which is not an advantageous means in terms of workability.

Special table 2009-503161 Japanese Patent Laid-Open No. 2004-237023

  The present invention was created in order to solve the above-described conventional problems, and the purpose thereof is to easily remove organic dirt adhering to the surface of an article having a flat surface. The object is to provide an adhesive cleaner with improved workability.

  In order to achieve the above object, according to the present invention, there is provided an adhesive cleaner used for removing organic dirt adhered to the surface of an article having a flat surface. The adhesive cleaner includes a dirt catching unit that catches the organic dirt by contacting the flat surface. Moreover, as for the said dirt capture | acquisition part, the part which contacts the said surface is comprised with the adhesive. Furthermore, the part which contacts the said surface of the said dirt capture | acquisition part shows the adhesive force of less than 1 N / 25mm by the measured value based on the 180 degree peeling test prescribed | regulated to JISZ0237.

  According to the adhesive cleaner (dirt remover) having such a configuration, an organic dirt adhering to the surface (for example, human hand dirt or sebum dirt, or Cosmetics) can be captured and easily removed from the surface. Moreover, the part which contacts the said surface of a dirt capture | acquisition part shows the adhesive force of less than 1 N / 25mm by the measured value based on the 180 degree peeling test prescribed | regulated to JISZ0237. This means that the dirt catcher has excellent light release properties. Accordingly, when the cleaner is operated on the flat surface of the article (for example, when moving on the surface or when the cleaner is separated from the surface), almost no force is required, so that the dirt removal workability is excellent. . Furthermore, even if the surface of the article (for example, the display surface of a tablet-type information terminal) is covered with a peelable protective film, the above-mentioned light peelability does not remove the protective film (in other words, The surface can be cleaned while the protective film covers the surface of the article). And although it is such light peelability, an organic stain | pollution | contamination can fully be removed. The organic soil may contain inorganic substances such as sodium, potassium, and salts thereof, as is apparent from the fact that sebum secreted from the skin is contained as described above.

  In a preferred embodiment of the adhesive cleaner disclosed herein, the portion of the dirt capturing portion that contacts the surface is 0.01 to 0.5 N / 25 mm as measured based on a 180 ° peel test specified in JIS Z0237. Indicates adhesive strength. Such a light-peeling cleaner can realize more excellent dirt removal workability while sufficiently removing organic dirt.

  In a preferred embodiment of the adhesive cleaner disclosed herein, a cylindrical rolling member is provided, and the dirt catching portion is disposed on the outer peripheral surface of the rolling member. According to the cleaner having such a configuration, the dirt catching portion located on the outer circumferential surface efficiently removes organic dirt adhering to the flat surface by rolling the rolling member along the circumferential direction of the cylinder. be able to. Further, since the dirt trapping part is lightly peelable, there is little peeling resistance at the time of rolling, and the dirt removal workability is excellent.

  In a preferable aspect of the pressure-sensitive adhesive cleaner disclosed herein, the adhesive cleaner further includes a gripping member that supports the rolling member so as to freely roll. By comprising in this way, the user can remove organic dirt of a flat surface efficiently by grasping a grasping member and rolling a rolling member.

  In a preferred embodiment of the pressure-sensitive adhesive cleaner disclosed herein, the dirt capturing unit is configured as a single-sided pressure-sensitive adhesive sheet including a sheet-like support base material and a pressure-sensitive adhesive layer disposed on the support base material, The single-sided pressure-sensitive adhesive sheet is configured as a pressure-sensitive adhesive sheet roll by being wound with the pressure-sensitive adhesive layer outside. In the adhesive cleaner having such a configuration, it is possible to remove dirt on a flat surface using the outer peripheral surface of the adhesive sheet roll. Further, by removing the outer peripheral part used for removing dirt from the roll according to the frequency of use and the degree of dirt adhering to the pressure-sensitive adhesive layer constituting the outer peripheral surface (typically by peeling), the outer periphery An unused pressure-sensitive adhesive layer can be exposed on the surface. That is, the exposure of the unused pressure-sensitive adhesive layer to the outer surface can be easily updated. For this reason, desired dirt removal performance can always be maintained.

  Preferably, the adhesive sheet roll disclosed herein is configured to suppress the rail pulling phenomenon. Here, the rail pulling phenomenon is a direction opposite to the direction in which the sheet roll is wound on the surface to be cleaned (flat surface of the article) (typically, the wound single-sided adhesive sheet is peeled off). When the sheet is rolled (rotated) in the direction), the sheet adheres to the surface to be cleaned in the form of a belt starting from the end of the outer peripheral surface of the roll. By suppressing the occurrence of the rail pulling phenomenon, the roll can be smoothly rolled without stress on the flat surface, which is easy to use. Further, wasteful use of the pressure-sensitive adhesive sheet due to the occurrence of the rail pulling phenomenon (that is, waste of the sheet due to unintentional adhesion of the pressure-sensitive adhesive sheet to the surface) can be prevented.

  In a preferred embodiment of the pressure-sensitive adhesive cleaner disclosed herein, the pressure-sensitive adhesive layer contains an acrylic polymer in a proportion of 50% by mass or more. By adopting an acrylic polymer as an adhesive, it is possible to suitably realize both removal of organic dirt and light release properties. The acrylic polymer is preferably a crosslinked acrylic polymer. This further improves light peelability. Alternatively, the acrylic polymer is preferably a thermoplastic acrylic polymer. Thereby, formation of an adhesive layer becomes easy.

  Moreover, it is preferable that the said adhesive layer further contains a plasticizer. By including a plasticizer, peeling can be lightened, and dirt removal workability can be further improved. In addition, even if the dirt trapping ability is reduced as a result of use, there is an effect that the dirt catching ability is recovered within a relatively short time (for example, several minutes or several hours) (dirt catching ability recovery action). It is suitably exhibited.

  A preferable embodiment of the adhesive cleaner disclosed herein is used for removing human sebum soil as the organic soil. The removal of human sebum soil effectively despite the fact that the adhesive cleaner having the predetermined configuration disclosed herein is lightly peelable is a matter that has been realized for the first time by the study of the present inventors. The above-mentioned adhesive cleaner is particularly suitable for use in removing human sebum dirt.

  In a preferred embodiment of the adhesive cleaner disclosed herein, the article is a portable device having a display surface made of glass or synthetic resin on the flat surface. Since the portable device is used by being carried on a daily basis, dust and organic dirt such as hand dirt, cosmetics, and sebum are likely to adhere to the portable device. In particular, for example, portable devices with a touch panel display surface (display / input unit) are operated by directly touching the display / input unit with a finger, so organic stains such as dirt, cosmetics, and sebum stains are more adhered. It's easy to do. The adhesive cleaner disclosed herein is particularly preferably used for removing dirt from a portable device having the display surface as described above (for example, a touch panel type display surface), because such organic dirt can be easily removed. In addition, although an adhesive type cleaner has been used conventionally (see, for example, Patent Document 2 above), a conventional roll-shaped cleaner is used for cleaning floors and carpets. It does not clean the flat surface (for example, a touch panel surface display / input unit) of a type information terminal or a smartphone.

It is a front view which shows typically the adhesion cleaner which concerns on one Embodiment. It is a side view which shows typically the adhesion cleaner concerning one embodiment. It is sectional drawing which shows typically the dirt capture | acquisition part which comprises the adhesion cleaner which concerns on one Embodiment. It is a perspective view which shows typically an example of the usage condition of the adhesion cleaner which concerns on one Embodiment. It is a figure which illustrates typically the recovery effect of dirt removal ability of the adhesion cleaner concerning one embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. Further, in the following drawings, members / parts having the same action are described with the same reference numerals, and overlapping descriptions may be omitted or simplified.

  Unlike conventional adhesive cleaners used for floor and carpet cleaning, the adhesive cleaner disclosed herein is used to remove organic contaminants adhering to the flat surface of articles such as portable devices. The article to be used for the adhesive cleaner disclosed herein is not particularly limited as long as it has a flat surface. For example, a show window glass, a glass table, a showcase, etc. are mentioned. Organic stains adhering to the flat surfaces they typically have (typically transparent glass surfaces) are unsightly and should be removed as soon as they are found. Therefore, it can be a preferred target for use of the adhesive cleaner disclosed herein.

  Moreover, various portable devices are mentioned as a suitable example of the articles | goods for which the adhesive cleaner disclosed here is used. Here, the portable device refers to a portable device having a flat surface on at least a part of the outer surface, and is not limited to a specific device. Examples thereof include portable devices such as notebook PCs, tablet information terminals such as electronic books, smartphones and other mobile phones, portable game machines, and PDAs (personal digital assistants) such as electronic notebooks. Since these are carried and used on a daily basis, dust and organic dirt such as hand dirt, cosmetics and sebum are likely to adhere to them. Some of these portable devices have a display surface such as a liquid crystal display or an organic EL display on a flat surface (typically a surface made of glass or synthetic resin). If organic dirt adheres, it is difficult to see the information displayed on the display surface, which is not convenient. In addition, depending on the degree of organic soiling, it may give an unclean impression. A portable device having such a display surface can be a preferred target for use of the adhesive cleaner disclosed herein.

  In particular, a portable device having a touch panel type display unit / input unit is more susceptible to the above-described organic contamination because the user directly touches the display surface with a finger. Therefore, it can be a preferred target for use of the adhesive cleaner disclosed herein. Among them, since the display surface of a tablet information terminal such as an electronic book is relatively large, it is grasped as a particularly preferable target for use of the adhesive cleaner.

  Hereinafter, an adhesive cleaner according to an embodiment will be described with reference to the drawings. As shown in FIGS. 1 and 2, an adhesive cleaner (hereinafter also simply referred to as “cleaner”) 10 includes a cylindrical holding member (core) 20, and an adhesive sheet roll 30 held on the outer peripheral surface of the holding member 20. Is provided. The holding member 20 and the pressure-sensitive adhesive sheet roll 30 are integrally formed as a cylindrical rolling member. The material of the holding member is not particularly limited, and those made of polyolefin or other synthetic resin or paper can be preferably used.

  The cleaner 10 further includes a rod-shaped gripping member 40 that supports the holding member 20 in a rollable manner. Specifically, a central hole (not shown) is formed in the holding member 20 at a position that becomes the central axis of the cylinder, and an end (one end) of the gripping member 40 is inserted into the central hole. Thus, the holding member 20 is attached to the gripping member 40 so as to be rotatable. A handle 42 is attached to the other end of the gripping member 40. The material of the grip member and the handle is not particularly limited, and for example, a metal or synthetic resin can be used.

  The pressure-sensitive adhesive sheet roll 30 of the cleaner 10 is formed by winding a pressure-sensitive adhesive sheet 31 serving as a dirt capturing portion. Specifically, as shown in FIG. 3, the adhesive sheet (dirt capturing portion) 31 is a long sheet-shaped (band-shaped) support base material 36 and an adhesive disposed on one surface 36 </ b> A of the support base material 36. A single-sided pressure-sensitive adhesive sheet 31 including the agent layer 32 is configured. The single-sided pressure-sensitive adhesive sheet 31 is formed as a pressure-sensitive adhesive sheet roll 30 by being wound so that the pressure-sensitive adhesive layer 32 is on the outside.

  A usage mode of the cleaner 10 having the above-described configuration will be described. As shown in FIG. 4, the cleaner 10 is used to remove organic contaminants attached to the display unit 2 of the portable device 1. The display unit 2 of the portable device 1 has a flat surface. The operator places the cleaner 10 on the display unit 2 of the portable device 1, grips the handle 42, and applies a predetermined external force to the cleaner 10. Then, the external force is transmitted from the gripping member 40 to the holding member 20, and the pressure-sensitive adhesive layer 32 of the pressure-sensitive adhesive sheet roll 30 disposed on the outer peripheral surface of the holding member 20 (the portion in contact with the flat surface of the dirt capturing portion) is rolled. It moves on the display unit 2 while moving. In FIG. 4, the adhesive sheet roll 30 moves in the arrow direction on the display unit 2. At this time, the pressure-sensitive adhesive layer 32 captures dust and dirt present in the display unit 2, and particularly organic dirt such as human hand dirt and sebum. As a result, cleaning (dirt removal) of the display unit 2 is easily and reliably performed along the rolling direction of the adhesive sheet roll 30 (more specifically, the adhesive sheet (dirt capturing unit) 31). In addition, although the portable apparatus in this embodiment is a tablet-type information terminal in which the whole display part is comprised with flat tempered glass, such as aluminosilicate glass, it is as above-mentioned that it is not limited to this.

  The size of the cylindrical pressure-sensitive adhesive sheet roll is not particularly limited, but when the target of use is a portable device such as a tablet-type information terminal, the diameter (which means a diameter (outer diameter) when not in use; the same applies hereinafter) is 4 mm or more. (For example, 10 mm or more, typically 20 mm or more) is preferable. Further, from the viewpoint of operability and portability, the diameter is preferably 50 mm or less (for example, 35 mm or less, typically 30 mm or less).

  Further, in the pressure-sensitive adhesive sheet roll, it is preferable that the pressure-sensitive adhesive sheet is provided with a cut line (not shown) for cutting almost every circumference. This cut is a cutting means for efficiently renewing the pressure-sensitive adhesive layer surface (outer surface of the dirt catching portion) whose cleaning (dirt removal) performance has deteriorated after using the cleaner several times. For example, it may be a long hole or corrugated slit arranged, an intermittent slit such as a perforation. The cut is preferably provided so as to cross the pressure-sensitive adhesive sheet in the width direction (direction perpendicular to the longitudinal direction). In addition, the update of the outer peripheral surface of the dirt capturing unit is not limited to the cutting means. For example, intermittent slits such as perforations are formed in a spiral shape in a direction crossing the sheet winding direction of the adhesive sheet roll (typically, a direction intersecting at an angle of 30 to 60 ° with respect to the width direction). You may keep it. Alternatively, slits (continuous cuts) may be made at predetermined intervals in the adhesive sheet constituting the adhesive sheet roll instead of intermittent slits such as perforations. In this form, the pressure-sensitive adhesive sheet constituting the pressure-sensitive adhesive sheet roll is completely cut at predetermined intervals in the roll winding direction in advance, so that the outer surface of the pressure-sensitive adhesive sheet roll can be easily peeled off at each predetermined interval. The surface can be updated.

  The said cleaner 10 can be produced by employ | adopting a conventionally well-known method suitably. For example, the pressure-sensitive adhesive sheet roll 30 of the cleaner 10 can be produced by the same method as that of a conventional roll-shaped cleaner. That is, the pressure-sensitive adhesive layer 32 is formed by applying the pressure-sensitive adhesive composition onto the surface 36A of the long sheet-like support base 36 by various conventionally known coating means and then performing a drying process or the like. And the roll-shaped adhesive sheet roll 30 is formed by winding the adhesive sheet 31 around the holding member 20 so that the adhesive layer 32 may become an outer peripheral surface. Furthermore, the cleaner 10 is constructed by attaching the end of the gripping member 40 to the holding member 20 so as to be able to roll. The attachment structure of the gripping member 40 to the holding member 20 itself may be the same as that of a conventional roll-shaped cleaner, and does not characterize the present invention, so that detailed description is omitted.

  The adhesive cleaner is not limited to the one in the above embodiment. The adhesive cleaner may be composed of, for example, only a dirt catcher. As such an adhesive cleaner, for example, a cleaner composed only of a dirt trapping part such as a spherical shape, a columnar shape, a cylindrical shape, a hexahedral shape (for example, a rectangular parallelepiped shape), a sheet shape, and the like can be mentioned.

  Moreover, in the said embodiment, although the dirt capture | acquisition part was comprised from the support base material and the adhesive layer, it is not limited to this. For example, the dirt capturing part may be formed only from an adhesive (baseless adhesive). Alternatively, when the dirt capturing unit has a support base, the shape of the support base is not particularly limited. For example, the dirt trapping part may be one in which an adhesive layer is formed on the outer surface of a spherical support substrate.

  Furthermore, in the said embodiment, although the holding member supported the holding member so that rolling was possible, it is not limited to this. For example, the gripping member may be directly or indirectly connected (coupled or detachably connected) to the dirt capturing unit. As such an adhesive cleaner, for example, a stick-shaped gripping member having a columnar or rectangular parallelepiped-shaped adhesive body fixed to one end thereof can be mentioned. Alternatively, the gripping member may have a flat portion, and the dirt catching portion may be fixed to one surface of the flat portion.

  The dirt capturing part (for example, pressure-sensitive adhesive sheet) disclosed herein has a part (for example, pressure-sensitive adhesive surface) in contact with the flat surface of the article having a measured value based on a 180 ° peel test specified in JIS Z0237 of less than 1 N / 25 mm. It is characterized by exhibiting adhesive strength. This means that the dirt trapping part has excellent light peelability. A cleaner having such a light-peelable dirt catching portion is excellent in dirt removal workability because it requires little force when performing dirt removal work on the surface. More specifically, there is an advantage that the cleaner can be moved more smoothly on the flat surface of the article, and that the cleaner can be easily separated from the surface after removing dirt, for example. Furthermore, even when the surface of the article (for example, the display surface of a tablet-type information terminal) is covered with a peelable protective film (for example, a protective film made of a synthetic resin such as silicone or polyester), With this light release property, the surface can be cleaned without removing the protective film (in other words, while the protective film covers the surface of the article). In this case, the object to be cleaned is the surface of the protective film, but such a surface is also included in the flat surface of the article. The adhesive strength is preferably 0.8 N / 25 mm or less (for example, 0.6 N / 25 mm or less, typically 0.5 N / 25 mm or less) from the viewpoint of soil removal workability, and 0.57 N / 25 mm or less. (For example, 0.55 N / 25 mm or less, typically 0.4 N / 25 mm or less) is more preferable. Further, from the viewpoint of dirt trapping property, the adhesive strength is preferably 0.001 N / 25 mm or more (for example, 0.01 N / 25 mm or more, typically 0.02 N / 25 mm or more), and 0.03 N / 25 mm or more. (For example, 0.05 N / 25 mm or more, typically 0.08 N / 25 mm or more) is more preferable.

  The measurement of the adhesive strength is specifically performed according to the following procedure. A test piece is prepared by cutting a dirt catching portion (typically, an adhesive sheet) into a rectangular sheet. The test piece is preferably about 100 to 200 mm in length, and the width is preferably about 15 to 30 mm. When the width is not 25 mm, [N / 25 mm] may be calculated (converted) from the ratio of the actual width to 25 mm. The thickness is not particularly limited. The adhesive surface (for example, the adhesive layer side surface) of the obtained test piece is attached to a stainless steel (SUS304) plate by reciprocating a 2 kg roller. When the test piece has adhesiveness on both sides, such as a double-sided pressure-sensitive adhesive sheet, it is preferable to line a polyethylene terephthalate (PET) film having a thickness of about 25 μm with respect to the surface opposite to the measurement surface. After holding this for 30 minutes in an environment of 23 ° C. and RH 50%, using a tensile tester, in accordance with JIS Z0237, in an environment of 23 ° C. and RH 50%, a peeling angle of 180 ° and a tensile speed of 300 mm / min. Under the conditions, the adhesive strength [N / 25 mm] against SUS180 ° peeling is measured. The tensile tester is not particularly limited, and a conventionally known tensile tester can be used. For example, it can be measured using “Tensilon” manufactured by Shimadzu Corporation.

  Further, the dirt capturing portion (for example, an adhesive sheet) disclosed herein is in contact with the flat surface of the article instead of the SUS180 ° peel adhesive force or in addition to the SUS180 ° peel adhesive force. It may be characterized in that the adhesive strength of the portion (for example, the adhesive surface) to be peeled off by 180 ° with respect to the glass plate is less than 1 N / 25 mm. A cleaner having such a lightly peelable dirt catching portion is excellent in dirt removal workability. The adhesive strength is preferably 0.9 N / 25 mm or less (for example, 0.85 N / 25 mm or less, typically 0.5 N / 25 mm or less) from the viewpoint of dirt removal workability, and 0.57 N / 25 mm or less. (For example, 0.55 N / 25 mm or less, typically 0.4 N / 25 mm or less) is more preferable. Further, from the viewpoint of dirt trapping property, the adhesive strength is preferably 0.001 N / 25 mm or more (for example, 0.01 N / 25 mm or more, typically 0.02 N / 25 mm or more), and 0.03 N / 25 mm or more. (For example, 0.05 N / 25 mm or more, typically 0.06 N / 25 mm or more) is more preferable. The 180 ° peel adhesion to the glass plate (180 ° peel adhesion to glass) was measured except that a glass plate (for example, commercially available float plate glass) was used as the adherend. What is necessary is just to carry out similarly to [N / 25mm].

  Further, the dirt trapping portion (for example, an adhesive sheet) disclosed herein is in contact with the flat surface of the article instead of the SUS180 ° peel adhesive force or in addition to the SUS180 ° peel adhesive force. It may be characterized in that the 180 ° peel adhesion to the polyethylene terephthalate (PET) film at the part (eg adhesive surface) is less than 1 N / 25 mm. A cleaner having such a lightly peelable dirt catching portion is excellent in dirt removal workability. The adhesive strength is preferably 0.9 N / 25 mm or less (for example, 0.8 N / 25 mm or less, typically 0.6 N / 25 mm or less) from the viewpoint of dirt removal workability, and 0.5 N / 25 mm or less. (For example, 0.4 N / 25 mm or less is more preferable. From the viewpoint of dirt trapping property, the adhesive strength is 0.001 N / 25 mm or more (for example, 0.01 N / 25 mm or more, typically 0.02 N / The measurement of 180 ° peel adhesion to the PET film (against PET 180 ° peel adhesion) is performed using the above-mentioned SUS 180 ° peel adhesion except that a PET film is used as the adherend. What is necessary is just to carry out similarly to [N / 25mm].

  When the pressure-sensitive adhesive cleaner disclosed herein has a pressure-sensitive adhesive sheet roll, the pressure-sensitive adhesive sheet roll generates a rail pulling phenomenon on a flat surface of the article (for example, a surface made of glass such as aluminosilicate glass or synthetic resin). It is preferable that the adhesive force (for example, a measured value based on the 180 ° peel test) and the rewind force are harmonized so as to be suppressed. Here, the rewinding force is also grasped as a force required to pull out the pressure-sensitive adhesive sheet from the pressure-sensitive adhesive sheet roll (that is, resistance to rewinding, pressure-sensitive adhesive force to the back surface of the pressure-sensitive adhesive sheet (typically the back surface of the support substrate) ). For example, when the unwinding force is set too low compared to the adhesive force, the unwinding force is reduced between the adhesive sheet (typically the adhesive layer) and the surface when the adhesive sheet roll is rolled on a flat surface. There is a risk of causing a rail pulling phenomenon by losing the adhesive force between them. On the other hand, when the rewinding force is too high, the pressure-sensitive adhesive sheet tends not to be pulled out smoothly.

  The unwinding force can be evaluated as follows. That is, the pressure-sensitive adhesive sheet roll is set in a predetermined tensile testing machine, and the outer peripheral side tip of the wound pressure-sensitive adhesive sheet is attached to the chuck of the testing machine in an environment of a temperature of 23 ° C. and RH of 50%. The pressure-sensitive adhesive sheet roll is rewound in the tangential direction by pulling on the sheet, and the unwinding force at this time is obtained by converting the value (N / 150 mm) per width (for example, 150 mm) of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. Can do. For example, it is preferable that the rewinding force is about 0.5 to 2.5 N / 150 mm.

  The pressure-sensitive adhesive (for example, the pressure-sensitive adhesive layer) that constitutes the dirt trapping portion (for example, the pressure-sensitive adhesive sheet) is not particularly limited as long as it satisfies the above-mentioned SUS peeling adhesive force. For example, it can be a water-based pressure-sensitive adhesive composition, a water-based pressure-sensitive adhesive composition such as a water-dispersed pressure-sensitive adhesive composition, or a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition such as a solvent-type pressure-sensitive adhesive composition. A solventless pressure-sensitive adhesive formed from an active energy ray-curable pressure-sensitive adhesive composition or a hot-melt pressure-sensitive adhesive composition can also be preferably used. For the purpose of removing human sebum dirt, a solvent-based pressure-sensitive adhesive or a solventless pressure-sensitive adhesive is preferable, and a hot-melt pressure-sensitive adhesive is preferable from the viewpoint of handleability.

  Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives (for example, natural rubber-based pressure-sensitive adhesives), urethane-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. From the viewpoint of adhesive performance and cost, rubber adhesives or acrylic adhesives can be preferably employed.

  Among these, from the viewpoint of controlling the adhesive strength (light peelability), the adhesive is an acrylic adhesive containing an acrylic polymer as a base polymer (main component of the polymer component, main adhesive component). It is preferable. The acrylic polymer can be synthesized from a monomer raw material containing an alkyl (meth) acrylate having an alkyl group as a main monomer. Here, the main monomer refers to a monomer component occupying 50% by mass or more of the total monomer components. In the present specification, “(meth) acrylate” means acrylate and methacrylate comprehensively. Similarly, “(meth) acryloyl” refers to acryloyl and methacryloyl, and “(meth) acryl” generically refers to acrylic and methacryl.

Examples of the alkyl (meth) acrylate include the formula:
CH ₂ = CR ¹ COOR ²
A compound represented by; can be suitably used. Here, R ¹ in the above formula is a hydrogen atom or a methyl group. R ² is an alkyl group having 1 to 20 carbon atoms (hereinafter, such a range of the number of carbon atoms may be represented as “C _1-20 ”). From the viewpoint of the storage elastic modulus of the pressure-sensitive adhesive, an alkyl (meth) acrylate having a C _1-14 (for example, C _1-10 ) alkyl group is preferable. The alkyl group may be linear or branched.

Examples of the alkyl (meth) acrylate having a C _1-20 alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth). Acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl ( (Meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate Relate, isodecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, Examples include hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, and eicosyl (meth) acrylate. These alkyl (meth) acrylates can be used alone or in combination of two or more. Especially, the alkyl (meth) acrylate which has a _C4-9 alkyl group is preferable. Preferred examples include n-butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and isononyl acrylate. Among these, BA and 2EHA are more preferable, and 2EHA is particularly preferable.

  The blending ratio of the main monomer in all monomer components is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more. The upper limit of the mixing ratio of the main monomer is not particularly limited, but is preferably 99% by mass or less (for example, 98% by mass or less, typically 95% by mass or less). The acrylic polymer may be obtained by polymerizing only the main monomer.

  The monomer raw material used for polymerizing the acrylic polymer may contain a submonomer copolymerizable with the main monomer in addition to the main monomer for the purpose of improving various properties such as light release properties. In addition, the said submonomer shall contain not only a monomer but an oligomer. Examples of such a submonomer include a monomer having a functional group (hereinafter also referred to as a functional group-containing monomer). The functional group-containing monomer can be added for the purpose of introducing a crosslinking point into the acrylic polymer and increasing the cohesive strength of the acrylic polymer. Such functional group-containing monomers include carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group (hydroxyl group) -containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy group (glycidyl group) -containing monomers, alkoxy And group-containing monomers and alkoxysilyl group-containing monomers. These can be used alone or in combination of two or more. Among them, a functional group-containing monomer such as a carboxyl group, a hydroxyl group, or an epoxy group is preferable because a crosslinking point can be suitably introduced into the acrylic polymer and the cohesive force of the acrylic polymer can be further increased. More preferred are carboxyl group-containing monomers or hydroxyl group-containing monomers.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and citracone. Examples thereof include ethylenically unsaturated dicarboxylic acids such as acids. Of these, acrylic acid and / or methacrylic acid are preferable, and acrylic acid is particularly preferable.
Examples of the acid anhydride group-containing monomer include acid anhydrides such as the above ethylenically unsaturated dicarboxylic acids such as maleic anhydride and itaconic anhydride.
Examples of the hydroxyl group (hydroxyl group) -containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy. Unsaturated alcohols such as hydroxyalkyl (meth) acrylates such as butyl (meth) acrylate, N-methylol (meth) acrylamide, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether Etc.
Examples of the amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N- Examples include methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide.
Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, and the like.
Examples of the epoxy group (glycidyl group) -containing monomer include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether.
Examples of the alkoxy group-containing monomer include methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.
Examples of the alkoxysilyl group-containing monomer include 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, and 3- (meth). Examples include acryloxypropylmethyldiethoxysilane.

  When the functional group-containing monomer is used as a monomer constituting the acrylic polymer, the functional group-containing monomer (preferably a carboxyl group-containing monomer) is 1 to 10 mass in all monomer components for polymerizing the acrylic polymer. % (For example, 2 to 8% by mass, typically 3 to 7% by mass) is preferably blended.

  Further, as a secondary monomer, a monomer other than the functional group-containing monomer may be included for the purpose of increasing the cohesive force of the acrylic polymer. Examples of such monomers include vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene and the like), vinyl toluene, and the like.

  A method for polymerizing the monomer or a mixture thereof is not particularly limited, and a conventionally known general polymerization method can be employed. Examples of such a polymerization method include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. Of these, solution polymerization is preferred. The mode of polymerization is not particularly limited, and a conventionally known monomer supply method, polymerization conditions (temperature, time, pressure, etc.), and use components other than the monomer (polymerization initiator, surfactant, etc.) can be appropriately selected and carried out. it can. For example, as a monomer supply method, the entire monomer mixture may be supplied to the reaction vessel at a time (collective supply), or may be gradually dropped and supplied (continuous supply), or divided into several times for a predetermined time. Each quantity may be supplied (divided supply) every time. The monomer or a mixture thereof may be partially or entirely supplied as a solution dissolved in a solvent or a dispersion emulsified in water.

  The polymerization initiator is not particularly limited. For example, azo initiators such as 2,2′-azobisisobutyronitrile, peroxide initiators such as benzoyl peroxide, phenyl substituted ethane, etc. Examples thereof include substituted ethane-based initiators, redox-based initiators in which peroxides such as a combination of peroxide and sodium ascorbate and a reducing agent are combined. Although the usage-amount of a polymerization initiator can be suitably selected according to the kind of polymerization initiator, the kind of monomer (composition of a monomer mixture), etc., it is 0.005-1 normally with respect to 100 mass parts of all the monomer components normally. It is appropriate to select from a range of about part by mass. The polymerization temperature can be, for example, about 20 ° C. to 100 ° C. (typically 40 ° C. to 80 ° C.).

Moreover, it is preferable to mix | blend a crosslinking agent with an adhesive composition. For example, preferable examples of the crosslinking agent for the acrylic pressure-sensitive adhesive include organic metal salts such as zinc stearate and barium stearate, epoxy crosslinking agents, isocyanate crosslinking agents and the like. You may use an oxazoline type crosslinking agent, an aziridine type crosslinking agent, a metal chelate type crosslinking agent, and a melamine type crosslinking agent. These crosslinking agents may be used alone or in combination of two or more. Of these, epoxy crosslinking agents and isocyanate crosslinking agents can be suitably cross-linked with carboxyl groups, have good operability (typically light release properties), and are excellent in acid resistance. The combined use of an epoxy crosslinking agent and an isocyanate crosslinking agent is particularly preferred. The blending amount of the crosslinking agent is not particularly limited, but in order to realize the above-mentioned preferable numerical range of adhesive strength, 0.01 to 10 parts by mass (for example, 0. 05-5 parts by mass, typically 0.1-5 parts by mass). When the epoxy crosslinking agent (C _E ) and the isocyanate crosslinking agent (C _I ) are used in combination, the mass ratio (C _E / C _I ) is 0.01 to 1 (for example, 0.05 to 0.5, Typically 0.1 to 0.4) is preferable.

  In addition, when a solvent-based pressure-sensitive adhesive is employed, the solvent used is an aliphatic hydrocarbon such as hexane, heptane, or mineral spirit, an alicyclic hydrocarbon such as cyclohexane, toluene, xylene, solvent naphtha, tetralin, dipentene, or the like. Aromatic hydrocarbons, alcohols such as butyl alcohol, isobutyl alcohol, cyclohexyl alcohol, 2-methylcyclohexyl alcohol, tridecyl alcohol, esters such as methyl acetate, ethyl acetate, isopropyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone Etc. are mentioned as suitable examples.

  The molecular weight (Mw: weight average molecular weight) of the base polymer (for example, acrylic polymer) to be used (synthesized) is not particularly limited, but is a polymer having a weight average molecular weight (Mw) of about 300,000 to 1,000,000 (for example, approximately) (Acrylic polymer) can be preferably used.

  The acrylic polymer constituting the pressure-sensitive adhesive in the technology disclosed herein may be a thermoplastic polymer. A typical example is an acrylic block copolymer. As the acrylic block copolymer, one having at least one acrylate block (hereinafter also referred to as Ac block) and at least one methacrylate block (hereinafter also referred to as MAc block) can be preferably used. . For example, a block copolymer having a structure in which Ac blocks and MAc blocks are alternately arranged is preferable. The total number of blocks of the Ac block and the MAc block is preferably 3 or more (for example, 3 to 5).

  The Ac block typically has an alkyl acrylate as a main monomer (that is, a component occupying 50% by mass or more of the monomer units constituting the block). Of the monomer units, 75% by mass or more (for example, 90% by mass or more) may be alkyl acrylate. In a preferred embodiment, the Ac block contained in the acrylic block copolymer (in an acrylic block copolymer having two or more Ac blocks, at least one Ac block among them may be used, The monomer unit constituting the block may be substantially composed of only one or more (typically one) alkyl (meth) acrylates. Alternatively, the Ac block may be a copolymer of an alkyl (meth) acrylate and another monomer (such as an alkyl methacrylate).

  Examples of the alkyl acrylate constituting the Ac block include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate (BA), isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n -Hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate (2EHA), nonyl acrylate, isononyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate and the like. For example, a constitution in which the monomer constituting the Ac block is substantially BA alone, a constitution in which 2EHA is alone, a constitution comprising two types of BA and 2EHA, and the like can be preferably employed.

  The MAc block typically has an alkyl methacrylate as a main monomer. Of all the monomer components constituting the MAc, 75% by mass or more (for example, 90% by mass or more) may be alkyl methacrylate. In a preferred embodiment, the MAc block contained in the acrylic block copolymer (in the acrylic block copolymer having two or more MAc blocks, at least one MAc block may be used, The monomer unit constituting the block may be substantially composed of only one or more (typically one) alkyl methacrylate. Alternatively, the MAc block may be a copolymer of alkyl methacrylate and another monomer (for example, alkyl acrylate).

  Examples of the alkyl methacrylate constituting the MAc block include alkyl methacrylates having 1 to 20 (preferably 1 to 14) carbon atoms in the alkyl group. Specific examples thereof include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, Examples include n-octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, isononyl methacrylate, decyl methacrylate, dodecyl methacrylate, stearyl methacrylate and the like.

  In a preferred embodiment, 50% by mass or more (75% by mass or more or substantially all) of the monomers constituting the MAc block may be 1 to 1 carbon atoms in the alkyl group. 4 alkyl methacrylate. Among these, preferred alkyl methacrylates include methyl methacrylate (MMA) and ethyl methacrylate (EMA). For example, a configuration in which the monomer unit is substantially MMA alone, a configuration in which the monomer unit is EMA alone, a configuration composed of two types of MMA and EMA, and the like can be preferably employed.

  The acrylic block copolymer in the technology disclosed herein is viscous to the A block made of a polymer having a hard structure excellent in cohesion and elasticity, such as AB type, ABA type, ABAB type, and ABABA type. It may be copolymerized such that B blocks made of a polymer having an excellent soft structure are alternately arranged. The pressure-sensitive adhesive using the acrylic block copolymer having such a structure as a base polymer can be a pressure-sensitive adhesive layer in which cohesion, elasticity and viscosity are highly compatible. Moreover, the adhesive of this composition can be preferably used as a hot melt adhesive. An acrylic block copolymer (ABA type, ABABA type, etc.) having a structure in which A blocks are arranged at both ends of the molecule can be preferably used. An acrylic block copolymer having such a structure is preferable because it tends to have a good balance between cohesiveness and thermoplasticity.

  In the case where the acrylic block copolymer has two or more A blocks, the monomer composition, molecular weight (degree of polymerization), structure, etc. of these A blocks may be the same or different. The same applies to the B block when the acrylic block copolymer has two or more B blocks.

  As the A block, the MAc block as described above can be preferably adopted. As the B block, the Ac block as described above can be preferably adopted. In a preferred embodiment, the acrylic block copolymer is a triblock copolymer having a MAc block-Ac block-MAc block (ABA type) structure. For example, such a triblock copolymer in which two MAc blocks have substantially the same monomer composition can be preferably employed.

  The mass of the MAc block contained in the acrylic block copolymer (the total mass thereof when two or more MAc blocks are included) and the mass of the Ac block (there are two or more Ac blocks when including two or more Ac blocks) The ratio with respect to the total mass) is not particularly limited, but the mass ratio of MAc block / Ac block is 4/96 to 90/10 (usually 7/93 to 80/20, preferably 10/90 to 70/30, For example, a range of 20/80 to 50/50) is preferable. When the proportion of the MAc block is large, the adhesive strength is lowered, and light peelability tends to be easily obtained. When the ratio of the Ac block is large, the organic dirt capturing performance tends to be improved.

As the acrylic block copolymer, those having a weight average molecular weight (Mw) of about 3 × 10 ⁴ to 30 × 10 ⁴ can be appropriately employed. An acrylic block copolymer having an Mw of about 3.5 × 10 ^{4 to} 25 × 10 ⁴ is preferable, and more preferably 4 × 10 ^{4 to} 20 × 10 ⁴ (for example, 5 × 10 ⁴ to 15 × 10 ⁴ ). . If the Mw of the acrylic block copolymer is too small, the adhesive properties (for example, cohesiveness) may be easily reduced, and the light peelability may be reduced. If Mw is too large, the acrylic block copolymer tends to be insufficient in thermoplasticity. The Mw of the acrylic block copolymer referred to here is obtained by performing gel permeation chromatography (GPC) measurement on a sample prepared by dissolving the copolymer in an appropriate solvent (for example, tetrahydrofuran (THF)). The value in terms of polystyrene.

  In the acrylic block copolymer in the technique disclosed herein, monomers (other monomers) other than alkyl acrylate and alkyl methacrylate may be copolymerized. Examples of the other monomers include vinyl compounds having functional groups such as alkoxy groups, epoxy groups, hydroxyl groups, amino groups, amide groups, cyano groups, carboxyl groups, and acid anhydride groups, vinyl esters such as vinyl acetate, styrene, etc. Examples thereof include aromatic vinyl compounds and vinyl group-containing heterocyclic compounds such as N-vinylpyrrolidone. Alternatively, alkyl acrylates, fluorinated alkyl acrylates and fluorinated alkyl methacrylates having a structure in which a fluorinated alkyl group is bonded to an acryloyl group can be mentioned. The other monomers can be used, for example, for the purpose of adjusting the properties (adhesive properties, moldability, etc.) of the pressure-sensitive adhesive layer, and the content thereof is 20% by mass of the total monomer components constituting the acrylic block copolymer. It is appropriate to set it below (for example, 10 mass% or less, typically 5 mass% or less). In a preferred embodiment, the acrylic block copolymer contains substantially no other monomer.

  Such an acrylic block copolymer can be easily synthesized by a known method (for example, see JP-A Nos. 2001-234146 and 11-323072), or a commercially available product can be easily obtained. It can be obtained. Examples of the commercially available products include Kuraray's product name “LA polymer” series (for example, product numbers such as LA2140e and LA2250), Kaneka's product name “NABSTAR”, and the like. As a method for synthesizing the acrylic block copolymer, a method utilizing a living polymerization method can be preferably employed. According to the living polymerization method, it is possible to synthesize an acrylic block copolymer having excellent thermoplastic properties by maintaining the original weather resistance of the acrylic polymer and controlling the structure unique to the living polymerization method. In addition, since the molecular weight distribution can be controlled narrowly, a pressure-sensitive adhesive (and hence a pressure-sensitive adhesive sheet (dirt trapping part)) excellent in light release property can be realized while suppressing the lack of cohesiveness due to the presence of low molecular weight components. .

  When the adhesive (for example, adhesive layer) in the technology disclosed herein contains an acrylic block copolymer, the acrylic block copolymer may be used alone or in combination of two or more. it can. Further, in addition to the acrylic block copolymer, components other than the acrylic block copolymer may be included as an optional component for the purpose of controlling adhesive properties and the like. Examples of the optional component include polymers and oligomers other than the acrylic block copolymer. The blending amount of these polymers and oligomers (hereinafter also referred to as optional polymers) is suitably 50 parts by mass or less, preferably 10 parts by mass or less, per 100 parts by mass of the acrylic block copolymer. More preferably 5 parts by mass or less. In a preferred embodiment, the pressure-sensitive adhesive layer may contain substantially no polymer other than the acrylic block copolymer.

  Moreover, it is preferable to include a plasticizer in the adhesive composition in the technique disclosed here. Inclusion of a plasticizer improves light peelability. Moreover, since the viscosity of a composition falls, coating property improves. Furthermore, there is also an aspect that the organic dirt capturing property on the pressure-sensitive adhesive surface is improved by the inclusion of the plasticizer. Furthermore, since organic dirt captured on the surface of the pressure-sensitive adhesive is absorbed and diffused inside the pressure-sensitive adhesive (for example, the pressure-sensitive adhesive layer), even if the dirt capturing ability is reduced by repeated use, For example, a characteristic action (dirt catching ability recovery action) that the dirt catching ability is restored within a few minutes or hours is realized.

  The dirt trapping ability recovery action will be described with reference to FIG. As schematically shown in FIG. 5, when the adhesive layer 32 of the dirt catching portion (adhesive sheet) 31 is brought into contact with the flat surface 2 of the article 1 such as a portable device, the adhesive layer 32 adheres to the surface 2. The organic dirt 50 is captured. The pressure-sensitive adhesive layer 32 has a property of not only capturing the organic dirt 50 but also transferring it into the layer. Therefore, the organic dirt 50 attached to the surface of the pressure-sensitive adhesive layer 32 moves into the pressure-sensitive adhesive layer 32 over time, and the organic dirt 50 existing on the surface of the pressure-sensitive adhesive layer 32 is reduced, and finally the pressure-sensitive adhesive layer 32. On the surface, there is almost no organic dirt 50 present. That is, it returns to the state before using the adhesive cleaner. Therefore, the above-mentioned “recovery action” means that when the adhesive traps organic dirt and the dirt trapping ability temporarily decreases, the dirt is removed after a predetermined time (for example, several minutes, preferably several hours). This means that the trapping ability is restored and the adhesive (for example, the adhesive layer) can trap the dirt again, and includes that the time required for recovery of the dirt trapping ability is short.

  Examples of plasticizers include dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dibutyl phthalate and the like, or adipates such as dioctyl adipate and diisononyl adipate, or trioctyl trimellitic acid Trimellitic acid esters, sebacic acid esters, and the like. Softeners such as process oil are also included in the plasticizer. These can be used alone or in combination of two or more. Of these, adipic acid esters are preferred.

  Although the compounding quantity of a plasticizer is not specifically limited, It is suitable to set it as 1 mass part or more with respect to 100 mass parts of base polymers (for example, acrylic polymer). The amount is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more. The blending amount is suitably 100 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, and particularly preferably 50 parts by mass or less. . From the viewpoint of achieving both the dirt trapping performance and the dirt trapping performance recovery action, the blending amount of the plasticizer is 40 parts by weight or less (for example, 20 to 40 parts by weight, typically 25 to 25 parts by weight based on 100 parts by weight of the base polymer). 35 parts by mass) is preferable.

  In addition, the pressure-sensitive adhesive composition (or pressure-sensitive adhesive or pressure-sensitive adhesive layer) disclosed herein includes a tackifier, a surfactant, a chain transfer agent, an antioxidant, an antioxidant, an ultraviolet absorber, Various additive components known in the field of pressure-sensitive adhesives such as light stabilizers, antistatic agents, colorants (pigments, dyes, etc.) can be blended. The types and blending amounts of these additional components that are not essential components may be the same as the normal types and blending amounts of this type of pressure-sensitive adhesive.

  When forming an adhesive (for example, adhesive layer) from the adhesive composition disclosed here, the formation method is not particularly limited. For example, it is possible to apply a method in which the pressure-sensitive adhesive composition is directly applied (typically applied) to a substrate and dried by using a conventionally known application means such as a die coater or a gravure roll coater.

  The thickness of the pressure-sensitive adhesive layer can be appropriately selected according to the purpose, and is not particularly limited. From the viewpoint of sufficiently exhibiting the dirt trapping performance and improving the recoverability of the dirt trapping ability, the thickness of the pressure-sensitive adhesive layer is preferably about 10 μm or more (for example, 30 μm or more, typically 50 μm or more). In the case where weight reduction, miniaturization, etc. are important, the thickness of the pressure-sensitive adhesive layer is preferably 300 μm or less (for example, 100 μm or less, typically 70 μm or less). The pressure-sensitive adhesive layer may be formed over the entire range of one surface of the support substrate, or, for example, the pressure-sensitive adhesive layer is not formed along both ends in the width direction of the support substrate. You may have a non-adhesion part (dry edge).

  When the dirt capturing portion disclosed herein includes a support base material as in the above embodiment, for example, a material composed of various synthetic resins, non-woven fabrics, or paper can be used as the support base material. . The material of the support substrate may be a cloth, a rubber sheet, a foam sheet, a metal foil, a composite thereof, or the like.

  Examples of the synthetic resin include polyolefin (polyethylene, polypropylene, ethylene-propylene copolymer, etc.), polyester (polyethylene terephthalate, etc.), vinyl chloride resin, vinyl acetate resin, polyimide resin, polyamide resin, fluorine resin, and the like. In particular, a support substrate made of polyethylene terephthalate (PET) can be suitably used. Examples of paper include Japanese paper, craft paper, glassine paper, high-quality paper, synthetic paper, topcoat paper, and the like. Examples of the fabric include woven fabrics and non-woven fabrics made of various fibrous substances alone or by blending. Examples of the fibrous material include cotton, suf, manila hemp, pulp, rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber and the like. Examples of rubber sheets include natural rubber sheets and butyl rubber sheets. Examples of the foam sheet include a foamed polyurethane sheet and a foamed polychloroprene rubber sheet. Examples of the metal foil include aluminum foil and copper foil. For the support substrate, fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, plasticizers, and coloring, if necessary Various additives such as additives (pigments, dyes, etc.) may be blended.

  Further, when a single-sided pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is formed on one side of the support base material is adopted as the dirt trapping part, a silicone-based release agent is formed on the back surface of the support base material (surface where the pressure-sensitive adhesive layer is not formed). It is preferable that a surface treatment (typically, a peeling treatment to prevent the rewinding force from becoming too high) is applied to adjust the rewinding force of the pressure-sensitive adhesive sheet roll to an appropriate range, such as coating. .

  The thickness of the support substrate can be appropriately selected according to the purpose, and is not particularly limited. In general, the thickness is preferably about 20 μm or more (for example, 30 μm or more, typically 40 μm or more), and preferably about 200 μm or less (for example, 100 μm or less, typically 70 μm or less). It is.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to the specific examples. In the following description, “part” and “%” are based on mass unless otherwise specified.

<Example 1>
2-Ethylhexyl acrylate (2EHA) and acrylic acid (AA) were charged into a three-necked flask so that the mass ratio was 2EHA: AA = 95: 5 (the solvent used toluene was used), and under a nitrogen stream. Then, benzoyl peroxide is added as a polymerization initiator, the temperature is raised to 60 ° C. and reacted for 2 hours, and further heated to 80 ° C. and reacted for 1 hour, whereby the weight average molecular weight (Mw) is about 500,000. A solution of ˜600,000 acrylic polymer A was prepared. Next, with respect to 100 parts of the polymer solid content of the acrylic polymer solution, 30 parts of a plasticizer (diisononyl adipate: “Monocizer W-242”, product of DIC Corporation) and an epoxy-based crosslinking agent (Mitsubishi Gas Chemical Co., Ltd.) 0.1 part of “TETRAD-C” manufactured by the manufacturer and 2 parts of isocyanate crosslinking agent (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) were mixed to prepare an acrylic pressure-sensitive adhesive composition.

  After the acrylic pressure-sensitive adhesive composition obtained above is applied to the surface of a PET sheet-like support base (width: about 8 cm) having a thickness of 38 μm, a drying treatment is performed to obtain a thickness (glue thickness). ) A single-sided pressure-sensitive adhesive sheet in which an adhesive layer having a thickness of about 80 μm was formed on one side of the supporting substrate was produced. The obtained single-sided pressure-sensitive adhesive sheet was wound around the surface of a synthetic resin cylindrical holding member (diameter 20 mm) to form a pressure-sensitive adhesive sheet roll. Then, a cleaner as schematically shown in FIGS. 1 and 2 was constructed by mounting the holding member on the tip of the gripping member so as to roll (rotate) freely.

<Example 2>
A cleaner according to Example 2 was constructed in the same manner as in Example 1 except that the blending amount of the epoxy-based crosslinking agent was increased to 0.5 parts with respect to 100 parts of the polymer solid content of the acrylic polymer solution.

<Example 3>
A cleaner according to Example 3 was constructed in the same manner as Example 2 except that the amount of the plasticizer was increased to 60 parts with respect to 100 parts of the polymer solid content of the acrylic polymer solution.

<Example 4>
Mix 100 parts (solid content) of a commercially available acrylic block copolymer (acrylic polymer B) and 30 parts of a plasticizer (diisononyl adipate: “Monosizer W-242”, DIC Corporation product), A hot-melt acrylic pressure-sensitive adhesive was prepared. By applying the obtained acrylic pressure-sensitive adhesive in the molten state to the surface of a PET sheet-like support base (width: about 8 cm) having a thickness of 38 μm, a pressure-sensitive adhesive layer having a thickness (glue thickness) of about 50 μm Produced a single-sided PSA sheet formed on one side of the support substrate. A cleaner according to Example 4 was constructed in the same manner as Example 1 except that the obtained single-sided adhesive sheet was used.

<Example 5>
A cleaner according to Example 5 was constructed in the same manner as in Example 4 except that the amount of the plasticizer was increased to 100 parts with respect to 100 parts (solid content) of the acrylic block copolymer.

<Example 6>
A commercially available roll-shaped cleaner for flooring (trade name “Korokoro”: manufactured by NITOMES Corporation) was used as Example 6.

[Measurement of SUS180 ° peeling adhesive strength]
The adhesive sheet according to each example was cut to 200 mm × 25 mm to prepare a rectangular test piece. The adhesive surface (adhesive layer side surface) of the test piece was attached to a stainless steel (SUS304) plate by reciprocating a 2 kg roller, and this was held in an environment of 23 ° C. and RH 50% for 30 minutes, and then pulled. Using a tester, in accordance with JIS Z0237, measure the peel strength [N / 25mm] against SUS 180 ° against SUS 180 ° under the conditions of 23 ° C., RH 50%, peeling angle 180 °, and tensile speed 300 mm / min. did. The measurement was performed using “Tensilon” manufactured by Shimadzu Corporation. The results are shown in Table 1.

[Measurement of 180 ° peeling adhesion to glass]
With respect to the pressure-sensitive adhesive sheets according to Examples 1 to 3, the glass-180 ° peel adhesive strength was measured in the same manner as the above-mentioned SUS 180 ° peel-off adhesive strength [N / 25 mm] except that a glass plate was used as the adherend. A commercially available float plate glass was used as the glass plate. The results are shown in Table 1.

[Measurement of 180 ° peeling adhesion to PET]
For the pressure-sensitive adhesive sheets according to Examples 1 to 3, except that a PET film (thickness 50 μm) was used as the adherend, the adhesive strength to peel 180 ° against PET was the same as the above-mentioned SUS 180 ° peel-off adhesive strength [N / 25 mm]. Was measured. The results are shown in Table 1.

[Evaluation of dirt removal rate]
After preparing a tablet-type information terminal (iPad (trademark): Apple product) and carefully cleaning its display surface (flat surface made of aluminosilicate glass) with a cleaner, the handy gloss meter “Gloss Glossiness G0 (measurement angle 60 °) was measured using “Checker IG-331”. Next, the test subject's face and other sebum components adhering to the skin are rubbed onto the fingers, and organic dirt composed of the sebum components attached to the fingers is rubbed onto a part of the display surface of the tablet type information terminal and transferred. . The transfer amount of the organic soil was set to an amount that gives the glossiness of about 60 (G1). Then, the display surface with the sebum stain was cleaned with the cleaner according to each example. Specifically, the cleaner adhesive sheet roll according to each example was rotated once. The rolling speed was about 0.5 m / sec. The pressing force of the operator when rolling was about 700 g. Thereafter, the glossiness G2 (measuring angle 60 °) of the display surface is measured, and the stain removal rate (%) based on the formula: stain removal rate (%) = (G2−G1) / (G0−G1) × 100; ) The measurement was performed twice and the average value was recorded. The results are shown in Table 1.

  As shown in Table 1, all of the cleaners according to Examples 1 to 5 show an adhesive strength of less than 1 N / 25 mm as measured based on a 180 ° peel test specified in JIS Z0237, and have excellent light peelability. It was what had. In addition, the cleaners according to these examples realized organic dirt removal performance superior to the cleaner according to Example 6 having relatively strong adhesive force, despite the light release properties as described above. Similar to normal dirt, organic dirt such as human fat dirt was thought to require more than a certain level of adhesive force. It has been demonstrated that the removal performance is demonstrated. This is a matter that has been clarified for the first time by the study of the present inventors. Further, the light-peeling adhesive cleaner as described above is capable of removing the protective film from the surface without peeling off the protective film due to the light-peeling property even when the surface of the portable device is covered with a peelable protective film. In this case, it can be expected to clean the surface of the protective film. This is understood by those skilled in the art because of the low peel adhesion to the synthetic resin PET.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

1 Portable equipment (goods)
2 Surface (display part)
10 Adhesive cleaner 20 Holding member 30 Adhesive sheet roll 31 Adhesive sheet (dirt capturing part)
32 Adhesive layer 36 Base material 40 Grip member 42 Handle 50 Organic dirt

Claims (9)

An adhesive cleaner used to remove organic dirt adhered to a surface of an article having a flat surface,
It has a dirt catching part that catches the organic dirt by contacting the flat surface,
The dirt capturing part is configured by a pressure-sensitive adhesive part in contact with the surface,
The pressure-sensitive adhesive contains a thermoplastic acrylic polymer in a proportion of 50% by mass or more,
The acrylic polymer is an acrylic block copolymer,
The acrylic block copolymer comprises at least one acrylate block and at least one methacrylate block,
The ratio (mass ratio of methacrylate block / acrylate block) of the mass of the methacrylate block and the mass of the acrylate block contained in the acrylic block copolymer is in the range of 4/96 to 90/10,
Portion in contact with the surface of the dirt trapping part shows the adhesive strength of 0.02 to 0.8 N / 25 m m measured value based on the 180 ° peel test specified in JIS Z0237, adhesive cleaners organic soil removal . 2. The adhesive cleaner according to claim 1, wherein a portion of the dirt catching portion that contacts the surface exhibits an adhesive force of 0.02 to 0.5 N / 25 mm as measured based on a 180 ° peel test specified in JIS Z0237. .   The pressure-sensitive adhesive cleaner according to claim 1, further comprising a cylindrical rolling member, wherein the dirt catching portion is disposed on an outer peripheral surface of the rolling member.   The pressure-sensitive adhesive cleaner according to claim 3, further comprising a gripping member that supports the rolling member so as to freely roll. The dirt capturing part is configured as a single-sided pressure-sensitive adhesive sheet comprising a sheet-like support base material and a pressure-sensitive adhesive layer disposed on the support base material,
The pressure-sensitive adhesive cleaner according to claim 1, wherein the single-sided pressure-sensitive adhesive sheet is configured as a pressure-sensitive adhesive sheet roll by being wound with the pressure-sensitive adhesive layer facing outward.   The pressure-sensitive adhesive cleaner according to claim 5, wherein the pressure-sensitive adhesive layer further contains a plasticizer. The pressure-sensitive adhesive cleaner according to claim 1, wherein the acrylic block copolymer has a weight average molecular weight of 3 × 10 ⁴ to 30 × 10 ⁴ .   The adhesive cleaner according to any one of claims 1 to 7, which is used for removing human sebum dirt as the organic dirt.   The adhesive cleaner according to claim 1, wherein the article is a portable device having a display surface made of glass or synthetic resin on the flat surface.

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