JP6204125B2 - Adhesive sheet for test piece - Google Patents

Description

  The present invention relates to an adhesive sheet used for a test piece for analyzing a sample.

  Various sample measuring devices for measuring blood glucose concentration and the like are widely used. The measurement using such a measuring device is performed by, for example, sampling a sample such as a blood sample on a test piece, setting the test piece holding the sample on the measuring device, and detecting information from the test piece. Is called. Patent document 1 is mentioned as a prior art document which discloses the test piece used for the said measuring instrument.

JP 2006-308458 A

  Said test piece is comprised from several members, such as a board | substrate, a spacer, a cover, for example, and these structural members need to closely_contact | adhere at the time of test piece preparation or use. If the adhesion between the constituent members is not sufficient, inconvenience such as leakage of the sample occurs, which may cause a decrease in the production efficiency of the test piece. However, since the bonding area of the constituent members in the test piece is very small, it is not easy to achieve good adhesion. Creation of an adhesive means having good adhesion and excellent productivity is desired.

  This invention is made | formed in view of the said conventional situation, and it aims at providing the adhesive sheet excellent in the adhesiveness applicable to the test piece for analyzing a sample.

  According to this invention, the adhesive sheet used for the test piece for analyzing a sample is provided. This pressure-sensitive adhesive sheet includes a pressure-sensitive adhesive layer constituting at least one surface of the pressure-sensitive adhesive sheet. Moreover, the adhesive surface of the said adhesive layer shows the adhesive force of 12 N / 20mm or more. The pressure-sensitive adhesive sheet exhibiting the above-mentioned adhesive strength (hereinafter also referred to as peel strength) exhibits good adhesion, and therefore a test piece for analyzing a sample (hereinafter also simply referred to as “test piece” for convenience). Can exhibit performance applicable to By applying the pressure-sensitive adhesive sheet disclosed herein to a test piece, a test piece excellent in productivity in which inconvenience such as leakage of the sample is avoided or sufficiently suppressed is provided.

  In a preferred embodiment of the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive layer contains a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound as a base polymer. Among these, the base polymer is preferably a styrenic block copolymer.

  In a preferred embodiment of the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive layer contains a tackifier resin. Moreover, it is preferable that the said tackifying resin contains high softening point resin whose softening point is 120 degreeC or more. Further, the high softening point resin preferably contains a terpene phenol resin. Further, the tackifying resin preferably contains a low softening point resin having a softening point of less than 120 ° C.

  In a preferred embodiment of the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive sheet comprises a base material, a first pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer provided on one surface of the base material, and the other base material. It is comprised as a double-sided adhesive sheet provided with the 2nd adhesive layer provided in the surface. Moreover, it is preferable that the adhesive surface of said 1st adhesive layer shows the adhesive force of 12 N / 20mm or more.

  In a preferred embodiment of the pressure-sensitive adhesive sheet disclosed herein, the test piece is a biosensor that is detachably connected to a biological sample measuring instrument. Analyzing accuracy of sample measuring devices such as biological sample measuring devices represented by biosensors has been increasing year by year, and accordingly, there is a tendency for higher quality test pieces to be required. The pressure-sensitive adhesive sheet disclosed herein can realize excellent adhesion, and thus can contribute to the creation of a higher quality test piece (typically a biosensor). Therefore, the pressure-sensitive adhesive sheet disclosed herein can be preferably applied to a biosensor used for analysis of a biological sample.

  Moreover, according to this invention, the test piece for sample analysis provided with the adhesive sheet disclosed here is provided. In a preferable aspect of the technology disclosed herein, the pressure-sensitive adhesive sheet may be a pressure-sensitive adhesive sheet disposed as a spacer between the substrate and the coating layer in a test piece including the substrate and the coating layer. Such a pressure-sensitive adhesive sheet can function not only as an adhesive means but also as a constituent member in the test piece.

It is a schematic perspective view which shows the structure of the test piece which concerns on one Embodiment. It is typical sectional drawing which expands and shows the cross section in the II-II line | wire of FIG. It is typical sectional drawing which shows the structure of the adhesive sheet (double-sided adhesive sheet with a base material) which concerns on one Embodiment. It is typical sectional drawing which shows the structure of the adhesive sheet (base-material-less double-sided adhesive sheet) which concerns on other embodiment. It is typical sectional drawing which shows the structure of the adhesive sheet (single-sided adhesive sheet with a base material) which concerns on other 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. In the following drawings, members / parts having the same action are described with the same reference numerals, and redundant descriptions may be omitted or simplified. In addition, the embodiment described in the drawings is schematically illustrated in order to clearly explain the present invention, and does not accurately represent the size and scale of the pressure-sensitive adhesive sheet actually provided as a product.

In this specification, the “pressure-sensitive adhesive” refers to a material that exhibits a soft solid (viscoelastic body) state in a temperature range near room temperature and has a property of easily adhering to an adherend by pressure. The adhesive here is generally defined as “CA Dahlquist,“ Adhesion: Fundamental and Practice ”, McLaren & Sons, (1966) P. 143”, and generally has a complex tensile modulus E ^* (1 Hz). <10 < ⁷ > dyne / cm < ² > material (typically a material having the above properties at 25 [deg.] C.). The “base polymer” of the pressure-sensitive adhesive is the main component (that is, 50% by mass of the rubber-like polymer) of the rubber-like polymer (polymer exhibiting rubber elasticity in the temperature range near room temperature) contained in the pressure-sensitive adhesive. Component which occupies the above).

<Applicable items for adhesive sheet>
The pressure-sensitive adhesive sheet disclosed herein is used as a test piece (sample analysis test piece) for analyzing a sample. In this specification, the “test strip” is defined as an object (also referred to as a test strip) used for analyzing a sample. For example, the sample may have a function of sampling (typically collecting and / or holding) a sample. The test piece disclosed here is typically a member (a member used together with a measuring device) that can be set in various sample measuring devices having an analysis function, whereby the sample is analyzed. The test piece may be preferably a sensor having a function of analyzing the sample (for example, a function of making information (for example, component concentration) from the sample detectable by using a chemical reaction). Here, the sample to be analyzed is not particularly limited, and examples thereof include biological samples such as whole blood, plasma, serum, saliva, urine, and cerebrospinal fluid. The sample may be various foods, drinking water, drainage, rainwater, and the like. Although the form of a sample is not specifically limited, The sample which exhibits a liquid state at normal temperature is preferable. Also, the purpose of analysis is not particularly limited, and may be, for example, measurement of the concentration of a specific component in a sample such as glucose concentration in blood. When the sample is a blood sample, examples of the analysis target include components such as albumin, lactic acid, bilirubin, and cholesterol in addition to the glucose. The pressure-sensitive adhesive sheet in the technology disclosed herein is preferably used for a test piece (hereinafter also referred to as a biosensor) for analyzing a biological sample (preferably a blood sample).

  Sample analysis using a test piece can be performed, for example, by setting a test piece holding a sample in a sample measuring device. Such a sample measuring device can be, for example, a portable small-sized measuring device (for example, a biological sample measuring device) for the purpose of medical treatment or health promotion. The test strip disclosed herein (for example, a medical test strip) may have a structure (shape, size, etc.) that is detachably connected to the biological sample measuring instrument as described above. Such test strips can typically be disposable test strips (typically also referred to as strips or chips). As an example of the usage mode of the test piece, a usage mode in which a case containing a plurality of test pieces and the measuring device are carried, sample analysis is performed at an appropriate timing, and used test pieces are discarded. Is mentioned. Hereinafter, a test piece (biosensor) for measuring blood glucose concentration will be described as a suitable application target of the pressure-sensitive adhesive sheet disclosed herein with reference to the drawings, but the technology disclosed herein is limited to this. Is not to be done.

  As shown in FIGS. 1 and 2, the test piece 30 includes a substrate 40, a coating layer 50, and the pressure-sensitive adhesive sheet 1 disposed between the substrate 40 and the coating layer 50. The shape can be expressed as a long flat plate. In this embodiment, the substrate 40 is a resin substrate and includes a resin plate 42 and an insulating layer 44 provided on the resin plate 42. The board | substrate should just be comprised with the material which has the insulating property in the surface which forms the electrode mentioned later, and the whole may consist of an insulating material. Materials constituting the substrate include polyesters such as polyethylene terephthalate (PET), polyolefins such as polyethylene (PE) and polypropylene (PP), polyamides such as nylon, polycarbonate, polyimide, polystyrene, polymethyl methacrylate, acrylonitrile butadiene styrene resin ( ABS materials), organic materials (typically resins) such as fluororesins, and inorganic materials such as glass. These can be used alone or in combination of two or more.

  On the surface of the substrate 40, strip-like electrodes 46a, 46b, 46c are arranged in stripes so as to have a predetermined interval, whereby an electrode pattern is formed on the surface of the substrate 40. These electrodes 46a, 46b, and 46c are for detecting a current generated by the reaction between the analyte and the reagent. The electrode material may be a conductive material, and for example, a carbon electrode is preferably used. Since the electrode pattern is formed on the surface of the substrate 40 as described above, the surface of the substrate 40 has irregularities. In this embodiment, the height of each of the electrodes 46a, 46b, 46c is about 10 to 20 μm, the width is in the range of about 0.5 to 1.0 mm, and the distance between the electrodes is about 0.2. Within the range of ~ 2 mm.

  The pressure-sensitive adhesive sheet 1 has a form of a double-sided pressure-sensitive adhesive sheet having pressure-sensitive adhesive surfaces on both sides, and functions as a spacer between the substrate 40 and the coating layer 50 while joining the substrate 40 and the coating layer 50. The adhesive sheet 1 is also provided with a U-shaped notch at one end in the longitudinal direction of the test piece 30. The space formed by this notch (in other words, the space surrounded by the adhesive sheet 1 located around the notch and the substrate 40 and the covering layer 50 covering the upper and lower sides) is the length of the test piece 30. It functions as a capillary part 60 having an opening (sample introduction port) 62 at one end in the direction. In the capillary part 60, the blood sample introduced from the opening 62 is held. In this embodiment, the width of the capillary part 60 (which may be a notch width) is about 1 mm, and the depth of the capillary part 60 is about 5 mm. Moreover, the base material 15 of the adhesive sheet 1 is colored white.

  The material of the coating layer 50 is not particularly limited, and the same type of material as exemplified as a material that can be used for the substrate 40 may be used. Or you may use the hydrophilic film | membrane comprised from hydrophilic polymers, such as carboxymethylcellulose (CMC), from a viewpoint of an analysis precision improvement.

  For example, the test piece 30 is used for analyzing a sample in the following manner. That is, a blood sample to be analyzed is introduced into the capillary part 60 from the opening 62 located at one end of the test piece 30 by capillary action. A reagent (for example, an oxidoreductase that reacts with glucose and an electron mediator) is disposed inside the capillary unit 60. This reagent generates an electric current by electrochemically reacting with an analyte (typically glucose) in the blood sample introduced into the capillary section 60. The glucose concentration in the blood sample is calculated by setting the test piece 30 in this state in the test piece insertion port of the measuring instrument and measuring the current value generated by the reaction in the instrument. About the reagent, any known or commonly used reagent that reacts electrochemically with the analyte or color reaction may be used as appropriate depending on the analyte, and does not characterize the present invention. No particular explanation is given here.

  The size of the test piece disclosed herein is not particularly limited, and may be set as appropriate according to the measuring instrument or the required sample amount. For example, it is disclosed here for a test piece having a length of about 15 to 50 mm (for example, 20 to 40 mm), a width of about 3 to 15 mm (for example, 4 to 10 mm), and a maximum thickness of about 100 to 2000 μm (for example, 300 to 600 μm). The adhesive sheet to be applied can be preferably applied. Further, the distance between the substrate and the coating layer (that is, the thickness of the spacer) that affects the volume of the capillary portion may be about 200 μm or less (for example, 120 μm or less, typically 70 μm or less). The thickness of the spacer may be the total thickness of the pressure-sensitive adhesive sheet (typically a double-sided pressure-sensitive adhesive sheet), for example, in the configuration of the above embodiment.

  The test piece having the above-described configuration is obtained by, for example, forming a plurality of electrode patterns on the surface of a sheet-like substrate and laminating a coating layer via a double-sided pressure-sensitive adhesive sheet to obtain a laminated structure. Is manufactured by punching into a plurality of (for example, 10 or more) test piece shapes. The electrode pattern may be formed by appropriately adopting a known method such as screen printing. The punching process is performed using a known or conventional processing machine. Therefore, the pressure-sensitive adhesive sheet used for the test piece adheres well to the electrode forming substrate as the adherend and the coating layer during the processing, and there is no inconvenience such as peeling that may cause leakage of the sample. It is required to have performance (typically adhesion and other adhesive performance). In addition, it is desirable that paste sticking and unpleasant odor are highly suppressed.

<Structural example of adhesive sheet>
The pressure-sensitive adhesive sheet disclosed herein (which may be in a long shape such as a tape shape) may be, for example, in the form of a double-sided pressure-sensitive adhesive sheet having a cross-sectional structure shown in FIG. The double-sided pressure-sensitive adhesive sheet 1 includes a plastic film as a base material 15, and a first pressure-sensitive adhesive layer 11 and a second pressure-sensitive adhesive layer 12 supported on both surfaces of the base material 15, respectively. More specifically, the first pressure-sensitive adhesive layer 11 and the second pressure-sensitive adhesive layer 12 are provided on the first surface 15B and the second surface 15A (both non-peelable) of the base material 15, respectively. As shown in FIG. 3, the double-sided pressure-sensitive adhesive sheet 1 before use (before being attached to an adherend) is wound in a spiral shape with the front surface 21A and the back surface 21B overlapped with a release liner 21 which is a release surface. It can be in the form of In the double-sided pressure-sensitive adhesive sheet 1 in this form, the surface of the second pressure-sensitive adhesive layer 12 (second pressure-sensitive adhesive surface 12A) is peeled off by the front surface 21B of the release liner 21, and the surface of the first pressure-sensitive adhesive layer 11 (first pressure-sensitive adhesive surface 11A) is peeled off. The liner 21 is protected by the back surface 21A. Alternatively, the first adhesive surface 11A and the second adhesive surface 12A may be protected by two independent release liners.

  The technology disclosed herein is preferably applied to a double-sided pressure-sensitive adhesive sheet with a substrate as shown in FIG. 3, and a double-sided pressure-sensitive adhesive sheet 2 having no base material (that is, having no base material) as shown in FIG. It can also be applied to. For example, as shown in FIG. 4, the double-sided pressure-sensitive adhesive sheet 2 before use is such that the first pressure-sensitive adhesive surface 11A and the second pressure-sensitive adhesive surface 11B of the substrate-less pressure-sensitive adhesive layer 11 are at least the surface (front surface) on the pressure-sensitive adhesive layer side. May be protected by release liners 21 and 22 that are release surfaces. Alternatively, the release liner 22 is omitted, and the release liner 21 having both sides of the release surface is used, and this and the adhesive layer 11 are overlapped and wound into a spiral shape, whereby the second adhesive surface 11B is released into the release liner. 21 may be in contact with the back surface of 21 and protected.

  As shown in FIG. 5, the technology disclosed herein is also a single-sided adhesive type substrate including a substrate 15 and an adhesive layer 11 supported on a first surface (non-peeling surface) 15 </ b> A of the substrate. The adhesive sheet 3 can also be applied. For example, as shown in FIG. 5, the pressure-sensitive adhesive sheet 3 before use has a release liner in which the surface (adhesive surface) 11 </ b> A of the pressure-sensitive adhesive layer 11 is at least the surface (front surface) on the pressure-sensitive adhesive layer side. 21 may be the protected form. Alternatively, the release liner 21 is omitted, and the first adhesive surface 11A is the second of the substrate 15 by winding the adhesive sheet 3 with the substrate using the substrate 15 having the second surface 15B as the release surface. It may be in a form protected against the surface 15B.

<Characteristics of adhesive sheet>
The pressure-sensitive adhesive sheet disclosed herein has a pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet (in the case of a double-sided pressure-sensitive adhesive sheet, preferably only the pressure-sensitive adhesive surface (first pressure-sensitive adhesive surface) of the first pressure-sensitive adhesive layer) of 12 N / It is characterized by showing a 180-degree peel strength of 20 mm or more (also referred to as “180-degree peeling adhesive strength” or simply “adhesive strength”). The pressure-sensitive adhesive sheet having the above-mentioned pressure-sensitive adhesive force can exhibit good adhesion as a pressure-sensitive adhesive sheet for test pieces having a small adhesion area. The adhesive strength is preferably 15 N / 20 mm or more, and more preferably 20 N / 20 mm or more. The pressure-sensitive adhesive sheet according to a particularly preferred embodiment may have an adhesive strength of 25 N / 20 mm or more (more preferably 30 N / 20 mm or more). If the test piece is of a small size that can be carried, its advantage is greater because its bonded area is smaller. For example, as in the test piece according to the embodiment shown in FIGS. 1 and 2, when one of the adhesion target surfaces of the pressure-sensitive adhesive sheet is an uneven surface in which electrodes are partially formed on the substrate surface, Since the area is further reduced, the advantage of having the above adhesive strength is particularly great. Moreover, the pressure-sensitive adhesive sheet having the above-mentioned pressure-sensitive adhesive force may be excellent in followability to the uneven surface. The 180-degree peel strength was 23 ° C. and 50% RH in an environment of a stainless steel plate (SUS304 plate) as an adherend, reciprocated with a 2 kg roller, and left for 30 minutes. It is measured under conditions of a tensile speed of 300 mm / min according to JIS Z0237. More specifically, the measurement of the adhesive force is performed according to the 180-degree peel strength measurement method described in Examples described later.

When the adhesive sheet disclosed here is a double-sided adhesive sheet, the adhesive force (180 degree peel strength) of the adhesive surface (second adhesive surface) of the second adhesive layer is not particularly limited. For example, in the usage mode in which high adhesion is required for one adhesive surface, such as the test piece according to the embodiment shown in FIGS. 1 and 2, the adhesive force of the second adhesive surface is 30 N / 20 mm or less (for example, 20 N). / 20 mm or less, typically 15 N / 20 mm or less). The lower limit value of the adhesive strength of the second adhesive surface may be 3N / 20 mm or more (for example, 5N / 20 mm or more, typically 10 N / 20 mm or more). In the use aspect of high adhesiveness with an adhesive surface, such one as described above is required, both surfaces of the first adhesive surface for adhesive strength PS ₂ of the second sensitive adhesive surface of the adhesive sheet adhesive strength PS ₁ disclosed herein The ratio (PS ₁ / PS ₂ ) is preferably 1.2 or more (eg, 1.5 or more, typically 1.8 or more). The upper limit of the ratio (PS ₁ / PS ₂ ) is not particularly limited, but can usually be about 3.0 or less (for example, 2.5 or less).

  In a preferred embodiment, the pressure-sensitive adhesive sheet disclosed herein has a phenol resin plate as an adherend for the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet (preferably both pressure-sensitive adhesive surfaces in the case of a double-sided pressure-sensitive adhesive sheet). Then, a 2 kg roller was reciprocated once with a bonding area of 10 mm in width and 20 mm in length, pressed down, left in an environment of 40 ° C. and left for 30 minutes, then applied with a load of 500 g and 1 in the same environment. In the constant load peeling test that is allowed to stand for a period of time, the time from when the load is applied until the pressure-sensitive adhesive sheet is peeled off from the adherend and dropped may be one hour or longer. A pressure-sensitive adhesive sheet having both the above characteristics and a pressure-sensitive adhesive force equal to or higher than the predetermined value can be a high-performance pressure-sensitive adhesive sheet in which both the pressure-sensitive adhesive force and the cohesive force are highly compatible. In a more preferred embodiment, in the constant load peel test, the displacement distance (mm) of the pressure-sensitive adhesive sheet after 1 hour from the application of the load is 3 mm or less (for example, 1 mm or less, typically 0.3 mm or less). possible. Since the pressure-sensitive adhesive sheet satisfying the above characteristics has an excellent cohesive force, the sticking out of the adhesive (a phenomenon in which the pressure-sensitive adhesive component protrudes from the end face of the adherend) can be suitably suppressed. Such an adhesive sheet can be preferably applied to a small-sized test specimen for sample analysis that can be carried. More specifically, the measurement of the constant load peel test is performed according to the 40 ° C. holding force measurement method described in Examples described later.

  In a preferred embodiment, the pressure-sensitive adhesive sheet disclosed herein has a liner peeling force (peeling strength against a release liner) on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet (preferably both pressure-sensitive adhesive surfaces in the case of a double-sided pressure-sensitive adhesive sheet). Can be less than 1 N / 50 mm (eg, 0.5 N / 50 mm or less, typically 0.4 N / 50 mm or less). A pressure-sensitive adhesive sheet satisfying this characteristic is easy to remove the release liner, and therefore has excellent workability. Considering that the workability may be lowered if the release force is too small, the liner release force is preferably about 0.01 N / 50 mm or more. The measurement of the liner peeling force is performed according to the method described in Examples described later.

  In a preferred embodiment, the pressure-sensitive adhesive sheet disclosed herein has an amount of toluene released from the sheet of 30 μg or less per 1 g of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive sheet is held at 150 ° C. for 30 minutes. possible. The pressure-sensitive adhesive sheet in which the amount of toluene emission is suppressed to a predetermined value or less can be used comfortably without an unpleasant odor because the outgas amount is suppressed. Such an adhesive sheet is particularly preferably used for, for example, a specimen for analyzing a biological sample (for example, a blood sample) for the purpose of medical use or health promotion. The toluene emission amount is more preferably 10 μg or less per 1 g of the pressure-sensitive adhesive layer, and further preferably 3 μg or less (for example, 1 μg or less, typically 0.3 μg or less). What is necessary is just to employ | adopt the value measured by the following method as said toluene emission amount.

[Toluene emission measurement]
The pressure-sensitive adhesive sheet is cut into a size of 1 cm × 1 cm, the release liner is peeled to expose the pressure-sensitive adhesive surface, and then the pressure-sensitive adhesive surface is bonded to an aluminum foil as a sample. After putting this sample in a 20 mL vial and sealing it, the vial is heated at 150 ° C. for 30 minutes, and 1.0 mL of the heated gas is injected into a gas chromatograph (GC) measuring device by a headspace autosampler. The amount of toluene is measured, and the amount of toluene emitted per gram of the pressure-sensitive adhesive layer contained in the sample (μg / g) is calculated.
At this time, the gas chromatograph conditions are as follows.
-Carrier gas: Helium-Column: Nonpolar capillary-Column-Column temperature: Temperature rising rate 10 ° C / min
Temperature maintained after temperature rise (low temperature) 40-300 ° C
-Column head pressure: 113 kPa (40 ° C.)
-Detector: FID (temperature: 250 ° C)
The quantification may be calculated based on a calibration curve prepared using a toluene-containing gas with a known gas amount. Specifically, the total area of each peak appearing from the start of temperature rise to 20 minutes may be converted to mass based on a calibration curve in terms of toluene, and the amount of toluene gas emitted may be quantified.

<Base polymer>
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet disclosed herein (which can also be grasped as the solid content of the pressure-sensitive adhesive composition) is known as an acrylic, rubber-based, It may contain one or more of various polymers such as polyester, urethane, polyether, silicone, polyamide, and fluorine. Especially, it is preferable that an adhesive is a rubber-type adhesive. The rubber-based pressure-sensitive adhesive refers to a pressure-sensitive adhesive containing a rubber-based polymer as a base polymer. Examples of the rubber-based polymer include natural rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), isoprene rubber, chloroprene rubber, polyisobutylene, butyl rubber, and recycled rubber. These can be used alone or in combination of two or more.

  The pressure-sensitive adhesive in the technology disclosed herein is preferably a rubber-based pressure-sensitive adhesive containing a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound as a base polymer. Here, “a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound” is a segment having a monovinyl-substituted aromatic compound as a main monomer (a copolymerization component exceeding 50% by mass; the same shall apply hereinafter). (Hereinafter also referred to as “A segment”) and a polymer having at least one segment having a conjugated diene compound as a main monomer (hereinafter also referred to as “B segment”). In general, the glass transition temperature of the A segment is higher than the glass transition temperature of the B segment. As a typical structure of such a polymer, a triblock copolymer (ABA structure triblock) having A segments (hard segments) at both ends of a B segment (soft segment), one A Examples thereof include a diblock structure copolymer (A-B structure diblock body) composed of a segment and one B segment.

  The monovinyl substituted aromatic compound refers to a compound in which one functional group having a vinyl group is bonded to an aromatic ring. A typical example of the aromatic ring is a benzene ring (which may be a benzene ring substituted with a functional group having no vinyl group (for example, an alkyl group)). Specific examples of the monovinyl-substituted aromatic compound include styrene, α-methylstyrene, vinyl toluene, vinyl xylene and the like. Specific examples of the conjugated diene compound include 1,3-butadiene and isoprene. Such a block copolymer can be used for a base polymer individually by 1 type or in combination of 2 or more types.

  The A segment (hard segment) in the block copolymer has a copolymerization ratio of 70% by mass or more (more preferably 90% by mass or more) of the monovinyl-substituted aromatic compound (two or more types can be used in combination). It may be substantially 100% by mass). The B segment (soft segment) in the block copolymer has a copolymerization ratio of the conjugated diene compound (two or more can be used in combination) of 70% by mass or more (more preferably 90% by mass or more). It may be 100% by mass). According to such a block copolymer, a higher performance pressure-sensitive adhesive sheet can be realized.

  The block copolymer may be in the form of a diblock body, a triblock body, a radial body, a mixture thereof, and the like. In the triblock body or radial body, it is preferable that an A segment (for example, a styrene block) is arranged at the end of the polymer chain. This is because the A segments arranged at the ends of the polymer chains are likely to gather to form a domain, thereby forming a pseudo cross-linked structure and improving the cohesiveness of the pressure-sensitive adhesive.

  As the block copolymer in the technology disclosed herein, the diblock ratio is 30% by mass or more (more preferably 40% by mass or more, more preferably 50% by mass or more) from the viewpoint of peel strength with respect to the adherend. Particularly preferably, 60% by mass or more, typically 65% by mass or more) can be preferably used. From the viewpoint of peel strength, a block copolymer having a diblock ratio of 70% by mass or more is particularly preferable. From the viewpoint of cohesion and the like, a block copolymer having a diblock body ratio of 90% by mass or less (more preferably 85% by mass or less, for example, 80% by mass or less) can be preferably used. For example, a block copolymer having a diblock ratio of 60 to 85% by mass is preferable, and a block copolymer having a diblock ratio of 70 to 85% by mass (for example, 70 to 80% by mass) is more preferable.

  When the pressure-sensitive adhesive disclosed here is a rubber-based pressure-sensitive adhesive, the amount of the polymer other than the rubber-based polymer is appropriately 50 parts by mass or less, preferably 30 parts by mass per 100 parts by mass of the base polymer. Hereinafter, it is more preferably 10 parts by mass or less (for example, 5 parts by mass or less). The technology disclosed herein is an embodiment in which the base polymer of the pressure-sensitive adhesive is substantially composed only of a rubber polymer (for example, an embodiment in which the content of the rubber polymer per 100 parts by mass of the base polymer is 99 to 100 parts by mass) ).

<Styrenic block copolymer>
In a preferred embodiment of the technology disclosed herein, the base polymer is a styrenic block copolymer. Here, the “styrene block copolymer” means a polymer having at least one styrene block. The styrene block refers to a segment having styrene as a main monomer. A segment consisting essentially of styrene is a typical example of a styrene block as used herein. The “styrene isoprene block copolymer” refers to a polymer having at least one styrene block and at least one isoprene block (a segment having isoprene as a main monomer). Typical examples of styrene isoprene block copolymers are triblock copolymer (triblock body) having styrene blocks (hard segment) at both ends of isoprene block (soft segment), one isoprene block and one styrene. Examples thereof include a diblock copolymer (diblock body) composed of blocks. The “styrene butadiene block copolymer” refers to a polymer having at least one styrene block and at least one butadiene block (a segment containing butadiene as a main monomer).

  As the styrene block copolymer in the technique disclosed herein, for example, an embodiment in which the base polymer includes at least one of a styrene isoprene block copolymer and a styrene butadiene block copolymer is preferable. Of the styrene block copolymer contained in the pressure-sensitive adhesive, the proportion of the styrene isoprene block copolymer is 70% by mass or more, the proportion of the styrene butadiene block copolymer is 70% by mass or more, or styrene. The total ratio of the isoprene block copolymer and the styrene butadiene block copolymer is preferably 70% by mass or more. In a preferred embodiment, substantially all (for example, 95 to 100% by mass) of the styrenic block copolymer is a styrene isoprene block copolymer. In another preferred embodiment, substantially all (for example, 95 to 100% by mass) of the styrenic block copolymer is a styrene butadiene block copolymer. According to such a composition, the effect of applying the technique disclosed here can be better exhibited.

  The styrenic block copolymer may be in the form of a diblock body, a triblock body, a radial body, a mixture thereof, and the like. In a triblock body and a radial body, it is preferable that the styrene block is arranged at the terminal of the polymer chain. This is because the styrene blocks arranged at the end of the polymer chain are likely to gather to form a styrene domain, thereby forming a pseudo cross-linked structure and improving the cohesiveness of the pressure-sensitive adhesive. The styrenic block copolymer used in the technology disclosed herein has a diblock ratio of 30% by mass or more (more preferably 40% by mass or more, and still more preferably 50%) from the viewpoint of peel strength with respect to the adherend. % By mass or more, particularly preferably 60% by mass or more, and typically 65% by mass or more). A styrene block copolymer having a diblock ratio of 70% by mass or more (for example, 75% by mass or more) may be used. From the viewpoint of cohesion and the like, a styrene block copolymer having a diblock body ratio of 90% by mass or less (more preferably 85% by mass or less, for example, 80% by mass or less) can be preferably used. From the viewpoint of balancing a plurality of adhesive properties (peel strength, holding power, etc.) in a well-balanced manner by applying the technology disclosed herein, a styrene block copolymer having a diblock ratio of 60 to 85% by mass is preferable. A 70-85 mass% (for example, 70-80 mass%) styrene-type block copolymer is more preferable.

  The ratio of the diblock body to the styrene block copolymer (hereinafter sometimes referred to as “diblock body ratio” or “diblock ratio”) is determined by the following method. That is, a styrene block copolymer is dissolved in tetrahydrofuran (THF), and GS5000H and G4000H liquid chromatographic columns manufactured by Tosoh Corporation are connected in two stages, for a total of four stages, and THF is used as the mobile phase. Then, high performance liquid chromatography is performed under conditions of a temperature of 40 ° C. and a flow rate of 1 mL / min. The peak area corresponding to the diblock body is measured from the obtained chart. And the diblock body ratio is calculated | required by calculating the percentage of the peak area corresponding to the said diblock body with respect to the whole peak area.

  The styrene content of the styrenic block copolymer may be, for example, 5 to 40% by mass. From the viewpoint of cohesiveness, a styrene block copolymer having a styrene content of 10% by mass or more (more preferably more than 10% by mass, for example, 12% by mass or more) is preferable. From the viewpoint of peel strength, the styrene content is preferably 35% by mass or less (typically 30% by mass or less, more preferably 25% by mass or less), and 20% by mass or less (typically less than 20% by mass). For example, 18% by mass or less) is particularly preferable. From the viewpoint of better exerting the effect of applying the technology disclosed herein (for example, the effect of improving the peel strength and holding force), the styrene block having a styrene content of 12% by mass or more and less than 20% by mass is used. A polymer can be preferably employed. The “styrene content” of the styrenic block copolymer refers to the mass ratio of the styrene component to the total mass of the block copolymer. The styrene content can be measured by NMR (nuclear ceramic resonance spectrum method).

<Tackifying resin>
The pressure-sensitive adhesive disclosed herein preferably contains a tackifier resin in addition to the base polymer. The tackifying resin is selected from various known tackifying resins such as petroleum resins, styrene resins, coumarone / indene resins, terpene resins, modified terpene resins, rosin resins, rosin derivative resins, and ketone resins. Species or two or more can be used.

  Examples of petroleum resins include aliphatic (C5) petroleum resins, aromatic (C9) petroleum resins, aliphatic / aromatic copolymer (C5 / C9) petroleum resins, and hydrogenated products thereof ( Examples thereof include alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins.

  Examples of the styrenic resin include those based on a homopolymer of styrene, those based on an α-methylstyrene homopolymer, those based on a vinyltoluene homopolymer, styrene, A main component of a copolymer containing two or more of α-methylstyrene and vinyltoluene in the monomer composition (for example, an α-methylstyrene / styrene copolymer having an α-methylstyrene / styrene copolymer as a main component) Polymer resin) and the like.

  As the coumarone-indene resin, a resin containing coumarone and indene as a monomer component constituting the resin skeleton (main chain) can be used. Examples of monomer components that can be contained in the resin skeleton other than coumarone and indene include styrene, α-methylstyrene, methylindene, and vinyltoluene.

  Examples of terpene resins include α-pinene polymers, β-pinene polymers, dipentene polymers, and the like. Examples of the modified terpene resin include those obtained by modifying the terpene resin (phenol modification, styrene modification, hydrogenation modification, hydrocarbon modification, etc.). Specific examples include terpene phenol resins, styrene-modified terpene resins, hydrogenated terpene resins, and the like.

  The above-mentioned “terpene phenol resin” refers to a polymer containing a terpene residue and a phenol residue, a copolymer of a terpene and a phenol compound (terpene-phenol copolymer resin), and a terpene homopolymer or copolymer. It is a concept that includes both a combination (terpene resin, typically unmodified terpene resin) and phenol-modified (phenol-modified terpene resin). Preferable examples of the terpene constituting the terpene phenol resin include monoterpenes such as α-pinene, β-pinene and limonene (including d-form, l-form and d / l-form (dipentene)).

  Specific examples of the rosin resin include unmodified rosins such as gum rosin, wood rosin and tall oil rosin (raw rosin); modified rosins modified by hydrogenation, disproportionation, polymerization, etc. (hydrogenation) Rosin, disproportionated rosin, polymerized rosin, and other chemically modified rosins). Examples of rosin derivative resins include those obtained by esterifying unmodified rosin with alcohols (that is, rosin esterified products) and modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) with alcohols. Rosin esters such as esterified products (ie, esterified products of modified rosin); Unmodified rosin or modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acid Rosins; Unsaturated fatty acid-modified rosin esters obtained by modifying rosin esters with unsaturated fatty acids; Unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid-modified rosin or Rosin alcohols with reduced carboxyl groups in saturated fatty acid-modified rosin esters; unmodified rosin, modified Metal salts of rosins (particularly rosin esters) such as gin and various rosin derivatives; obtained by adding phenol to an rosin (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermal polymerization. Rosin phenol resin; and the like.

<High softening point resin>
Adhesives disclosed herein, as the tackifying resin, a softening point preferably contains 120 ° C. or more tackifying resin (high softening point resin) T _H. From the viewpoint of aggregation property, the softening point of the high softening point resin _{T H} is preferably at least 125 ° C., more preferably at least 130 ° C., more preferably 135 ° C. or higher (e.g., 140 ° C. or higher). Further, from the viewpoint of peel strength to the adherend, the softening point of the high softening point resin T _H is suitably about 200 ° C. or less, preferably 180 ° C. or less, more preferably 170 ° C. or less (e.g., 160 ° C. or less ).

  The softening point of the tackifying resin disclosed herein is defined as a value measured based on the softening point test method (ring ball method) defined in JIS K5902 and JIS K2207. Specifically, the sample is melted as quickly as possible, and is carefully filled so that no bubbles are formed in the ring placed on a flat metal plate. After cooling, cut off the raised part from the plane including the top of the ring with a slightly heated sword. Next, a supporter (ring stand) is put in a glass container (heating bath) having a diameter of 85 mm or more and a height of 127 mm or more, and glycerin is poured until the depth becomes 90 mm or more. Next, the steel ball (diameter 9.5 mm, weight 3.5 g) and the ring filled with the sample are immersed in glycerin so as not to contact each other, and the temperature of glycerin is maintained at 20 ° C. plus or minus 5 ° C. for 15 minutes. . Next, a steel ball is placed on the center of the surface of the sample in the ring, and this is placed in a fixed position on the support. Next, the distance from the upper end of the ring to the glycerin surface is maintained at 50 mm, a thermometer is placed, the center of the mercury bulb of the thermometer is set to the same height as the center of the ring, and the container is heated. The flame of the Bunsen burner used for heating is placed between the center and the edge of the bottom of the container so that the heating is even. It should be noted that the rate at which the bath temperature rises after reaching 40 ° C. after heating has started must be 5.0 plus or minus 0.5 ° C. per minute. The temperature at the time when the sample gradually softens and flows down from the ring and finally comes into contact with the bottom plate is read and used as the softening point. Two or more softening points are measured simultaneously, and the average value is adopted.

Adhesives disclosed herein as a high softening point resin T _H, for example, can be used terpene phenol resins, rosin phenolic resins, polymerized rosin, the esterified products of polymerized rosin. Such high softening point resins can be used singly or in combination of two or more. As a preferred embodiment, it includes embodiments comprising one or more terpene phenol resin as a high-softening point resin T _H. A terpene phenol resin having a softening point of 120 ° C. or higher and 200 ° C. or lower (typically 120 ° C. or higher and 180 ° C. or lower, eg, 125 ° C. or higher and 170 ° C. or lower) can be preferably used. If the softening point is too low, the holding force may tend to decrease. If the softening point is too high, the peel strength with respect to the adherend may tend to decrease.

Although not particularly limited, as a preferred embodiment, for example, more than 25 wt% of a high softening point resin T _H (more preferably at least 30 wt%) can be cited aspects a terpene phenol resin. Least 50 wt% of a high softening point resin T _H (more preferably 70 mass% or more, still more preferably 80 mass% or more, e.g. 90 wt% or more) may be a terpene phenol resin, high softening point resin T _H Substantially all (for example, 95% by mass or more) may be a terpene phenol resin.

Art disclosed herein, for example, as a high softening point resin _{T H,} preferably carried out in a manner that includes a tackifier resin (a high softening point _{resin) T H1} having a hydroxyl value of 80 mg KOH / g or more (e.g. 90 mgKOH / g or higher) Can be done. The hydroxyl value of the high softening point resin _{T H1} is typically less 200 mg KOH / g, preferably 180 mg KOH / g or less (e.g., 160 mgKOH / g or less). According to the pressure-sensitive adhesive containing the high softening point resin _TH1 , a higher-performance pressure-sensitive adhesive sheet can be realized. A pressure-sensitive adhesive sheet that achieves a higher level of cohesion (for example, high-temperature cohesion) and other properties (for example, peel strength) can be realized. In the art disclosed herein, high softening point resin T _H1 includes a block copolymer of is more preferably used in combination with the rubber-based polymer as the base polymer, monovinyl-substituted aromatic compound and a conjugated diene compound It is particularly preferred to use in combination with a base polymer.

Here, as the value of “hydroxyl value” in this specification, a value measured by a potentiometric titration method defined in JIS K0070: 1992 can be adopted. The specific measurement method is as follows.
[Measurement method of hydroxyl value]
1. Reagent (1) As an acetylating reagent, about 12.5 g (about 11.8 mL) of acetic anhydride is taken, and pyridine is added thereto to make a total volume of 50 mL, and the mixture is sufficiently stirred. Alternatively, about 25 g (about 23.5 mL) of acetic anhydride is taken, and pyridine is added thereto to make a total volume of 100 mL, and the mixture is sufficiently stirred.
(2) As a measuring reagent, a 0.5 mol / L potassium hydroxide ethanol solution is used.
(3) Prepare toluene, pyridine, ethanol and distilled water.
2. Operation (1) About 2 g of a sample is accurately weighed in a flat bottom flask, 5 mL of an acetylating reagent and 10 mL of pyridine are added, and an air cooling tube is attached.
(2) The flask was heated in a bath at 100 ° C. for 70 minutes, allowed to cool, and 35 mL of toluene was added as a solvent from the top of the condenser and stirred, and then 1 mL of distilled water was added and stirred to acetic anhydride. Disassemble. Heat again in the bath for 10 minutes to complete decomposition and allow to cool.
(3) Wash the cooling tube with 5 mL of ethanol and remove it. Next, 50 mL of pyridine is added as a solvent and stirred.
(4) Add 25 mL of 0.5 mol / L potassium hydroxide ethanol solution using a whole pipette.
(5) Potentiometric titration with 0.5 mol / L potassium hydroxide ethanol solution. The inflection point of the obtained titration curve is the end point.
(6) In the blank test, the above (1) to (5) are performed without putting a sample.
3. Calculation The hydroxyl value is calculated by the following formula.
Hydroxyl value (mgKOH / g) = [(BC) × f × 28.05] / S + D
here,
B: Amount of 0.5 mol / L potassium hydroxide ethanol solution used for the blank test (mL),
C: The amount of 0.5 mol / L potassium hydroxide ethanol solution used for the sample (mL),
f: factor of 0.5 mol / L potassium hydroxide ethanol solution,
S: Mass of sample (g),
D: Acid value,
28.05: 1/2 of the molecular weight of potassium hydroxide 56.11,
It is.

The high softening point resin T _H1, those having a predetermined value or more hydroxyl number of high softening point resin T _H of the various described above, can be used in combination singly or in combination of two or more thereof as appropriate . In a preferred embodiment, at least a terpene phenol resin is used as the high softening point resin _TH1 . The terpene phenol resin is preferable because the hydroxyl value can be arbitrarily controlled by the copolymerization ratio of phenol. 50 wt% or more of the high softening point resin _{T H1} (more preferably 70 mass% or more, for example 90 or more mass%) is preferably is a terpene phenol resin, substantially all (e.g. 95 to 100 wt%, further May be terpene phenol resin.

Adhesives disclosed herein as a high softening point resin _{T H,} a hydroxyl value of 0 or 80 mg KOH / g of less than tackifier resin (high softening point _resin) may contain a _{T H2.} The high softening point resin T _H2, may be used instead of the high softening point resin T _H1, it may be used in combination with a high softening point resin T _H1. As a preferred embodiment, the hydroxyl value is between 80 mg KOH / g or more high softening point resin _{T H1,} it includes embodiments comprising a high softening point resin _{T H2.} Among them, the above-described rubber-based polymer as a base polymer, a block copolymerization with it is more preferable to use a combination of a high softening point resin T _H1 and T _H2, monovinyl-substituted aromatic compound as the base polymer and a conjugated diene compound It is particularly preferable to use the combination and the high softening point resins _TH1 and _TH2 in combination. The high softening point resin T _H2, those hydroxyl value of the high softening point resin T _H of the various described above is in the above range, it can be used in combination singly or in combination of two or more thereof as appropriate. For example, terpene phenol resins having a hydroxyl value of 0 or more and less than 80 mgKOH / g, petroleum resins (for example, C5 petroleum resins), terpene resins (for example, β-pinene polymer), rosin resins (for example, polymerized rosin), rosin A derivative resin (for example, esterified product of polymerized rosin) or the like can be used.

The art disclosed herein, the PSA is a hydroxyl value 80 mg KOH / g or more (typically 80~160mgKOH / g, for example 80~140mgKOH / g) and a high softening point resin _{T H1} of a hydroxyl value 0 mgKOH / g or 80 mg KOH / less g (typically 40 mg KOH / g or higher 80 mg KOH / less g) may be preferably carried out in a manner that includes a combination of a high softening point resin _{T H2} of. In this case, the relationship between the amounts used of T _H1 and T _H2 can be set so that, for example, the mass ratio (T _H1 : T _H2 ) is in the range of 1: 5 to 5: 1. It is appropriate to set it in the range of 3 to 3: 1 (for example, 1: 2 to 2: 1). A preferred embodiment is an embodiment in which T _H1 and T _H2 are both terpene phenol resins.

Adhesives disclosed herein, depending on the purpose, application, and the like, as a high softening point resin T _H, the tackifying resin has an aromatic ring and a hydroxyl value of at most 30 mgKOH / g (high softening point resin) T _It may contain _HR1 . This can effectively improve the cohesiveness (for example, high temperature cohesiveness). Tackifying resin _THR1 can be used individually by 1 type or in combination of 2 or more types. The hydroxyl value of the tackifier resin _{T HR1} is preferably less than 10 mgKOH / g, more preferably less than 5 mgKOH / g, more preferably less than 3 mgKOH / g. For example, hydroxyl value or is less than 1 mgKOH / g, or hydroxyl group may be used preferably a tackifier resin _{T HR1} undetected.

Examples of tackifying resins having an aromatic ring include the above-described aromatic petroleum resins, aliphatic / aromatic copolymer petroleum resins, styrene resins, coumarone-indene resins, styrene-modified terpene resins, phenol-modified terpene resins, A rosin phenol resin etc. are mentioned. Of these, those having a softening point of 120 ° C. or higher (preferably 130 ° C. or higher, eg 135 ° C. or higher) and a hydroxyl value of 30 mgKOH / g or lower (preferably less than 5 mgKOH / g, eg less than 1 mgKOH / g 2) It can be employed as the resin _THR1 .

Preferable examples of materials that can be used as the tackifying resin _THR1 include aromatic petroleum resins, aliphatic / aromatic copolymer petroleum resins, styrene resins, and coumarone-indene resins. As the aliphatic / aromatic copolymer petroleum resin, the copolymerization ratio of the C5 fraction is less than 15% by mass (more preferably less than 10% by mass, even more preferably less than 5% by mass, for example, less than 3% by mass). Is preferred. Moreover, the copolymerization ratio of C9 fraction is 55% by mass or more (more preferably 60% by mass or more, and further preferably 65% by mass or more). Particularly preferred tackifying resins _THR1 include aromatic petroleum resins and styrene resins (for example, α-methylstyrene / styrene copolymer resins).

The usage-amount of tackifying resin _THR1 is not restrict _| limited in particular, According to the objective and use of an adhesive, it can set suitably. From the viewpoint of aggregating property (for example, high temperature aggregating property), the amount of the tackifying resin _THR1 used relative to 100 parts by mass of the base polymer is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more. Moreover, from the viewpoint of making cohesiveness (for example, high temperature cohesiveness) and peel strength compatible at a high level, the amount of the tackifier resin _THR1 used relative to 100 parts by mass of the base polymer can be, for example, 100 parts by mass or less. 80 mass parts or less (for example, 60 mass parts or less) is preferable. Considering the adhesive performance (for example, peel strength) at low temperature, the amount of the tackifier resin _THR1 used relative to 100 parts by mass of the base polymer is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less (for example, 25 parts by mass or less). .

Although it does not specifically limit, In the aspect whose base polymer is a styrene-type block copolymer, the usage-amount of tackifying resin _{THR1 with} respect to 1 mass part of styrene components in this block copolymer is 0.1 mass, for example In terms of cohesiveness (for example, high temperature cohesiveness), 0.2 part by mass or more is preferable, and 0.5 part by mass or more is more preferable. Moreover, the usage-amount of tackifying resin _{THR1 with} respect to 1 mass part of styrene components in a block copolymer can be made into 10 mass parts or less, for example, and a cohesiveness (for example, high temperature cohesiveness) and peeling strength are a high level. Is preferably 7 parts by mass or less, more preferably 5 parts by mass or less.

In another preferable embodiment of the pressure-sensitive adhesive disclosed herein, the high softening point resin _TH has an aromatic ring and is substantially free of isoprene units, terpene skeleton and rosin skeleton (high softening point). Resin) may contain _THR2 . This effectively improves the cohesive force (for example, high-temperature cohesive force). Tackifying resin _THR2 can be used individually by 1 type or in combination of 2 or more types. Here, the tackifying resin _THR2 substantially does not contain an isoprene unit, a terpene skeleton, and a rosin skeleton. The proportion of these structural parts (that is, the isoprene unit, the terpene skeleton, and the rosin skeleton) in the tackifying resin _THR2. Is less than 10% by mass in total (more preferably less than 8% by mass, even more preferably less than 5% by mass, for example, less than 3% by mass). The said ratio may be 0 mass%. In addition, the ratio of the isoprene unit, the terpene skeleton, and the rosin skeleton in the tackifying resin _THR2 can be measured by, for example, NMR (nuclear ceramic resonance spectrum method).

Examples of tackifying resins having an aromatic ring and substantially free of isoprene units, terpene skeletons and rosin skeletons include the above-mentioned aromatic petroleum resins, aliphatic / aromatic copolymer petroleum resins, and styrene resins. And coumarone-indene resin. Among these, those having a softening point of 120 ° C. or higher (preferably 130 ° C. or higher, eg, 135 ° C. or higher) can be adopted as the tackifying resin _THR2 . Particularly preferred tackifying resins _THR2 include aromatic petroleum resins and styrene resins (for example, α-methylstyrene / styrene copolymer resins).

The amount of the tackifying resin _THR2 used is not particularly limited, and can be appropriately set according to the purpose and application of the pressure-sensitive adhesive. From the viewpoint of aggregating property (for example, high temperature aggregating property), the amount of the tackifying resin _THR2 used relative to 100 parts by mass of the base polymer is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more. Moreover, from the viewpoint of making cohesiveness (for example, high temperature cohesiveness) and peel strength compatible at a high level, the amount of the tackifier resin _THR2 used relative to 100 parts by mass of the base polymer can be, for example, 100 parts by mass or less. 80 mass parts or less (for example, 60 mass parts or less) is preferable. From the viewpoint of adhesive performance (for example, peel strength) at low temperature, the amount of the tackifier resin _THR2 used relative to 100 parts by mass of the base polymer is preferably 40 parts by mass or less, more preferably 30 parts by mass or less (for example, 25 parts by mass or less). preferable.

Although it does not specifically limit, In the aspect whose base polymer is a styrene block copolymer, the usage-amount of tackifying resin _{THR2 with} respect to 1 mass part of styrene components in this block copolymer is 0.1 mass, for example In terms of cohesiveness (for example, high temperature cohesiveness), 0.2 part by mass or more is preferable, and 0.5 part by mass or more is more preferable. Moreover, the usage-amount of tackifying resin _{THR2 with} respect to 1 mass part of styrene components in a block copolymer can be made into 10 mass parts or less, for example, and a cohesiveness (for example, high temperature cohesiveness) and peeling strength are a high level. Is preferably 7 parts by mass or less, more preferably 5 parts by mass or less.

Although not particularly limited, as the tackifier resin _{T HR2,} for the same reason as the tackifier resin _{T HR1,} hydroxyl value 30 mgKOH / g or less (preferably less than 5 mgKOH / g, for example less than 1 mgKOH / g) of those Can be preferably employed. Therefore, as the tackifying resin _THR2 in the technology disclosed herein, those corresponding to the tackifying resin _THR1 can be preferably used. Similarly, as tackifying resin _THR1 in the technique disclosed here, what corresponds also to tackifying resin _THR2 can be used preferably.

Adhesives disclosed herein may include a terpene phenol resin as a high-softening point resin T _H, the high softening point resin T _H total 25% by mass or more (more preferably at least 30 wt%) is a terpene phenolic resin It is preferable. Least 50 wt% of a high softening point resin T _H (more preferably 70 mass% or more, more preferably 80 mass% or more, for example 90 wt% or more) may be a terpene phenol resin, high softening point resin T _H Substantially all (for example, 95% by mass or more) may be a terpene phenol resin. For example, substantially all of the high softening point resin T _H can be a terpene phenol resin A and the terpene phenol resin B will be described later.

Adhesives disclosed herein, when a high softening point resin T _H terpene phenol resin, a terpene phenol resin 20 parts by mass or more with respect to 100 parts by mass of the base polymer (preferably 35 parts by mass or more, for example 40 weight Part or more). Usually, it is appropriate that the content of the terpene phenol resin is 100 parts by mass or less (preferably 80 parts by mass or less, for example 70 parts by mass or less).

In the art disclosed herein, when using a high softening point resin T _H, is not particularly limited, high softening point total of the resin T _H (i.e., softening point 120 ° C. or more adhesive to the base polymer 100 parts by weight From the viewpoint of cohesiveness (for example, high-temperature cohesiveness) and the like, the total amount of the imparting resin can be, for example, 10 parts by mass or more, preferably 20 parts by mass or more (preferably 25 parts by mass or more, for example, 35 parts by mass or more, Specifically, 40 parts by mass or more) is preferable. Further, from the viewpoint of peel strength and low temperature properties (e.g., low temperature peel strength), the content of the high softening point resin T _H for 100 parts by mass of the base polymer is usually suitably 120 parts by mass or less, preferably 100 parts by weight Below, more preferably 80 parts by mass or less (for example, 70 parts by mass or less, typically 60 parts by mass or less). By the amount of high softening point resin T _H for 100 parts by mass of the base polymer and 55 parts by mass or less (for example, 50 parts by mass or less), higher peel strength can be achieved.

The proportion of high softening point resin T _H of the total tackifying resin which may be contained in the adhesive disclosed herein is not particularly limited. The said ratio can be 30-90 mass%, for example, and 50-80 mass% is preferable. The art disclosed herein may be implemented in a manner that the adhesive does not include a high softening point resin T _H.

<Low softening point resin T _L >
As a suitable example of the aspect containing other tackifying resin, the aspect containing tackifying resin (low softening point resin) _TL with a softening point of less than 120 degreeC is mentioned. According to such an embodiment, for example, a pressure-sensitive adhesive sheet with better peel strength can be realized. The lower limit of the softening point of the low softening point resin _TL is not particularly limited. Those having a softening point of 40 ° C. or higher (typically 60 ° C. or higher) can be preferably used. A low softening point resin _TL having a softening point of 80 ° C. or higher (more preferably 100 ° C. or higher) and lower than 120 ° C. can be preferably employed from the viewpoint of achieving both high cohesiveness and peel strength. Especially, use of low softening point resin _TL whose softening point is 110 degreeC or more and less than 120 degreeC is preferable. The low softening point resin T _L, it is particularly preferable to use in combination with the high softening point resin T _H above. Further, the low softening point resin _TL is more preferably used in combination with the rubber-based polymer as a base polymer, and is used in combination with a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound as the base polymer. It is particularly preferred.

The hydroxyl value and structure of the low softening point resin _TL (for example, the presence or absence of an aromatic ring, the presence or absence of an isoprene unit, the presence or absence of a terpene skeleton, the presence or absence of a rosin skeleton) are not particularly limited. Various tackifying resins (petroleum resin, styrene resin, coumarone / indene resin, terpene resin, modified terpene resin, rosin resin, rosin derivative resin, ketone resin, etc.) having a softening point of less than 120 ° C. Those can be appropriately selected and used.

The technique disclosed here can be preferably implemented in a mode in which the pressure-sensitive adhesive contains at least one of a petroleum resin and a terpene resin as the low softening point resin _TL . For example, a composition in which the main component of the low softening point resin _TL (that is, a component occupying more than 50% by mass of the low softening point resin _TL ) is a petroleum resin, a composition that is a terpene resin, a petroleum resin and a terpene resin A composition that is a combination of the above and the like can be preferably employed. From the viewpoint of peel strength and compatibility, an embodiment in which the main component of the low softening point resin _TL is a terpene resin (for example, β-pinene polymer) is preferable. A terpene resin may be sufficient as substantially all (for example, 95 mass% or more) of low softening point resin _TL .

When the adhesive as disclosed herein comprises a low softening point resin T _L, the total amount of low softening point resin T _L for 100 parts by mass of the base polymer is not particularly limited, it can be, for example, 10 parts by mass or more, peeling From the viewpoint of strength, 15 parts by mass or more is preferable, and 20 parts by mass or more is more preferable. The total amount of the low softening point resin _TL with respect to 100 parts by mass of the base polymer is suitably 120 parts by mass or less, preferably 90 parts by mass or less, and 70 parts by mass or less (for example, 60 parts by mass or less) from the viewpoint of cohesiveness. ) Is more preferable. The content of the low softening point resin _TL may be 50 parts by mass or less (for example, 40 parts by mass or less).

When the adhesive as disclosed herein includes a low softening point resin T _L and a high softening point resin T _H, the relationship between their usage, T _L: Mass ratio of T _H 1: 5 to 3: 1 It is preferable to set so as to be (more preferably 1: 5 to 2: 1). The art disclosed herein, the embodiments the adhesive is rich in _{T H} than _{T L} as the tackifier resin _(e.g., T L: Mass ratio of _{T H} 1: 1.2 to 1: 5) It can be preferably implemented. According to this aspect, a higher performance pressure-sensitive adhesive sheet can be realized.

The proportion of the low softening point resin _{TL in} the total tackifying resin that can be included in the pressure-sensitive adhesive disclosed herein is not particularly limited. The said ratio can be 10-70 mass%, for example, and 20-50 mass% is preferable. In addition, you may implement the technique disclosed here in the aspect which does not contain low softening point resin _TL .

<Combination of terpene phenol resins having different hydroxyl values>
The pressure-sensitive adhesive disclosed herein is a form containing a base polymer composed of a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound, and a tackifier resin, and the terpene phenol resin A is used as the tackifier resin. And terpene phenol resin B at least. Here, the terpene phenol resin A and the terpene phenol resin B have a hydroxyl value A _OH (mg KOH / g) of the terpene phenol resin A and a hydroxyl value B _OH (mg KOH / g) of the terpene phenol resin B of A _OH > B _OH It is preferable to select so as to satisfy the relationship. By using the terpene phenol resins A and B in combination, for example, the peel strength (particularly, peel strength after time) of the pressure-sensitive adhesive sheet can be improved.

Typically, the difference between the hydroxyl value _{A OH} and hydroxyl value _{B OH,} i.e. _A OH _{-B OH} is such that the larger 200 mg KOH / g or less than 0, it is appropriate to select a terpene phenol resin A, B . In a preferred embodiment, A _OH -B _OH is 5 to 150 mg KOH / g (typically 10 to 120 mg KOH / g, more preferably 15 to 100 mg KOH / g, such as 20 to 80 mg KOH / g or less).

The hydroxyl value of each of the terpene phenol resins A and B is not particularly limited. For _{example, A OH} and _{B OH} are both 80 mg KOH / g or more (typically 80~250mgKOH / g, preferably 80~220mgKOH / g, for example 90~160mgKOH / g) may _{be, A OH} and B _OH is less than both 80 mg KOH / g (typically less than 0 or 80 mg KOH / g, preferably less than 10 mgKOH / g or higher 80 mg KOH / g, for example 20~70mgKOH / g) may _{be, a OH} is 80 mg KOH / g not less _{than, B OH} may be less than 80 mg KOH / g. In a preferred embodiment, A _OH is 80 mg KOH / g or more (typically 80 to 160 mg KOH / g, preferably 80 to 140 mg KOH / g, such as 90 to 120 mg KOH / g), and B _OH is less than 80 mg KOH / g (typical thereof include 0 to less than 80 mg KOH / g, preferably less than 10 mgKOH / g or higher 80 mg KOH / g, for example 20~70mgKOH / g) and is, and _a OH _{-B OH} is 10 mgKOH / g or more (preferably 20 mgKOH / g or more, For example, it is 30 mgKOH / g or more, and typically 100 mgKOH / g or less).

  Each content of terpene phenol resin A and B can be 1 mass part or more with respect to 100 mass parts of base polymers, respectively. In order to better demonstrate the effect of using the terpene phenol resin A and the terpene phenol resin B in combination, the content of the terpene phenol resins A and B with respect to 100 parts by mass of the base polymer is 5 parts by mass or more ( It is preferably 10 parts by mass or more, for example, 15 parts by mass or more. In addition, from the viewpoint of peel strength with respect to the adherend (particularly peel strength at low temperature), the total content of the terpene phenol resins A and B is usually 100 parts by mass or less with respect to 100 parts by mass of the base polymer. Is preferably 90 parts by mass or less, more preferably 80 parts by mass or less (for example, 70 parts by mass or less). For example, an embodiment in which the total content of the terpene phenol resins A and B with respect to 100 parts by mass of the base polymer is 15 to 80 parts by mass (typically 25 to 60 parts by mass) can be preferably adopted.

The mass ratio (m _A : m _B ) between the content m _A of the terpene phenol resin _A and the content m _B of the terpene phenol resin B can be, for example, 1:10 to 10: 1. From the viewpoint of the balance between the peel strength to the adherend and the constant load peel characteristics (particularly the constant load peel characteristics under wet heat conditions), the mass ratio (m _A : m _B ) is usually set to 1: 5. 5: 1 is appropriate, for example, 1: 3 to 3: 1. In a preferred embodiment, the mass ratio _m A / _{m B} is 0.7 to 10 (more preferably 0.8 to 5, typically 0.9 to 4, e.g., 1 to 3) and so as to _m A, m _B can be set. According to such an embodiment, a pressure-sensitive adhesive sheet having excellent resistance to continuous stress and excellent temporal stability of adhesive performance (for example, peel strength) can be realized.

  The softening points of the terpene phenol resins A and B are not particularly limited. For example, the softening points of the terpene phenol resins A and B are both 120 ° C. or higher (typically higher than 120 ° C., preferably 125 ° C. or higher, such as 130 ° C. or higher, typically 180 ° C. or lower). Both may be less than 120 ° C. Moreover, the softening point of any one of terpene phenol resin A and B may be 120 degreeC or more, and the other softening point may be less than 120 degreeC. In a preferred embodiment, the terpene phenol resins A and B each have a softening point in the range of 120 ° C to 170 ° C. For example, terpene phenol resin A having a softening point of 120 ° C to 170 ° C and a hydroxyl value of 80 to 140 mgKOH / g, and a softening point of 120 ° C to 170 ° C and a hydroxyl value of less than 80 mgKOH / g (for example, 20 A combination with terpene phenol resin B which is ˜70 mg KOH / g) can be preferably employed.

  In addition, the adhesive disclosed here may further contain terpene phenol resins other than the terpene phenol resin A and the terpene phenol resin B as the tackifier resin. When the pressure-sensitive adhesive contains three or more types of terpene phenol resins, two types are selected from the terpene phenol resins in descending order of mass-based content, and the higher hydroxyl value is selected from the terpene phenols. The resin A and the lower hydroxyl value are referred to as terpene phenol resin B. In addition, for example, as the terpene phenol resin having the highest content on a mass basis, when three types of terpene phenol resins are included at a mass ratio of approximately 1: 1: 1, the one having the highest hydroxyl value is selected. The terpene phenol resin A is used, and the terpene phenol resin B is the one having the lowest hydroxyl value.

  When using the tackifying resin in the technology disclosed herein, the total amount of the tackifying resin with respect to 100 parts by mass of the base polymer is not particularly limited, but is usually 20 parts by mass from the viewpoint of realizing a good balance between cohesiveness and peel strength. The above is appropriate, preferably 30 parts by mass or more, and more preferably 40 parts by mass or more (for example, 50 parts by mass or more). In addition, from the viewpoint of low temperature characteristics (for example, low temperature peel strength), the content of the tackifier resin with respect to 100 parts by mass of the base polymer is usually suitably 200 parts by mass or less, preferably 150 parts by mass or less, and 120 parts by mass. The following (for example, 100 parts by mass or less) is more preferable.

<Isocyanate compound>
The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive (pressure-sensitive adhesive layer) disclosed herein may contain an isocyanate compound. According to such a pressure-sensitive adhesive composition, a higher-performance pressure-sensitive adhesive sheet (for example, excellent in repulsion resistance and constant load peeling characteristics) can be realized. As the isocyanate compound, polyfunctional isocyanate (refers to a compound having an average of two or more isocyanate groups per molecule, including those having an isocyanurate structure) can be preferably used. As this polyfunctional isocyanate, 1 type (s) or 2 or more types selected from the various isocyanate compounds (polyisocyanate) which have a 2 or more isocyanate group in 1 molecule can be used. Examples of such polyfunctional isocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates and the like.

  Specific examples of the aliphatic polyisocyanates include 1,2-ethylene diisocyanate; tetramethylene diisocyanate such as 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, 1,4-tetramethylene diisocyanate; -Hexamethylene diisocyanate such as hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,5-hexamethylene diisocyanate; Examples include 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and lysine diisocyanate.

  Specific examples of alicyclic polyisocyanates include isophorone diisocyanate; cyclohexyl diisocyanates such as 1,2-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate; 1,2-cyclopentyl diisocyanate, 1,3 -Cyclopentyl diisocyanate such as cyclopentyl diisocyanate; hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and the like.

  Specific examples of the aromatic polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, and 2,2′-diphenylmethane diisocyanate. 4,4′-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4′-diisocyanate, 2,2′-diphenylpropane-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxy Diphenyl-4,4'-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate.

  Examples of preferred isocyanate compounds include polyfunctional isocyanates having an average of 3 or more isocyanate groups per molecule. Such a trifunctional or higher functional isocyanate is a difunctional or trifunctional or higher polymer (typically a dimer or trimer), a derivative (for example, a polyhydric alcohol and two or more polyfunctional isocyanates). Addition reaction product), polymer and the like. For example, diphenylmethane diisocyanate dimer or trimer, hexamethylene diisocyanate isocyanurate (trimer adduct of isocyanurate structure), reaction product of trimethylolpropane and tolylene diisocyanate, trimethylolpropane and hexamer Examples of the reaction product with methylene diisocyanate include polyfunctional isocyanates such as polymethylene polyphenyl isocyanate, polyether polyisocyanate, and polyester polyisocyanate. As commercial products of such polyfunctional isocyanates, trade names “Duranate TPA-100” manufactured by Asahi Kasei Chemicals, trade names “Coronate L”, “Coronate HL”, “Coronate HK” manufactured by Nippon Polyurethane Industry Co., Ltd. “Coronate HX”, “Coronate 2096” and the like.

  When using an isocyanate compound, the amount used is not particularly limited. For example, the amount is more than 0 parts by mass and 10 parts by mass or less (typically 0.01 to 10 parts by mass) with respect to 100 parts by mass of the base polymer. Can do. Usually, it is appropriate that the amount of the isocyanate compound used is 100 to 10 parts by mass with respect to 100 parts by mass of the base polymer, and 0.1 to 5 parts by mass (typically 0.3 to 3 parts by mass, For example, it is preferable to set it as 0.5-1 mass part. By using an isocyanate compound within such a range, a pressure-sensitive adhesive sheet having an excellent performance balance can be realized.

<Other ingredients>
The pressure-sensitive adhesive disclosed herein may be a leveling agent, a crosslinking agent, a crosslinking aid, a plasticizer, a softening agent, a filler, a colorant (pigment, dye, etc.), an antistatic agent, an anti-aging agent, if necessary. It may contain various additives that are common in the field of pressure-sensitive adhesives, such as ultraviolet absorbers, antioxidants, and light stabilizers. About such various additives, a conventionally well-known thing can be used by a conventional method. The pressure-sensitive adhesive disclosed herein contains substantially no liquid rubber such as polybutene (for example, the content per 100 parts by mass of the base polymer may be 1 part by mass or less, and may be 0 part by mass). The embodiment can be preferably implemented. According to the pressure-sensitive adhesive, a pressure-sensitive adhesive sheet having more excellent repulsion resistance and / or constant load peeling characteristics can be realized.

  In a preferred embodiment, the pressure-sensitive adhesive is such that the total amount of the base polymer and the tackifying resin is 90% by mass or more of the total mass of the pressure-sensitive adhesive (that is, the mass of the pressure-sensitive adhesive layer constituted by the pressure-sensitive adhesive). It can be an occupying composition. For example, an embodiment in which the total amount of the base polymer and the tackifier resin is 90 to 99.8% by mass (typically, for example, 95 to 99.5% by mass) of the total mass of the adhesive can be preferably adopted. .

  In another preferred embodiment, the pressure-sensitive adhesive composition may be a composition substantially free of a chelate compound. Here, the chelate compound is, for example, a chelate compound of an alkaline earth metal oxide and a resin (alkylphenol resin or the like) having a functional group (hydroxyl group, methylol group or the like) capable of coordinating the oxide. Point to. The technology disclosed herein can be preferably implemented in such a manner that the pressure-sensitive adhesive composition does not contain such a chelate compound at all or the content of the chelate compound is 1% by mass or less. According to such an embodiment, a pressure-sensitive adhesive sheet with more excellent adhesive strength can be realized.

  The form of the pressure-sensitive adhesive composition disclosed herein is not particularly limited. For example, the pressure-sensitive adhesive composition or pressure-sensitive adhesive in a form (solvent type) containing a pressure-sensitive adhesive (pressure-sensitive adhesive component) as described above in an organic solvent. Can be a pressure-sensitive adhesive composition in a form dispersed in an aqueous solvent (water-dispersed type, typically an aqueous emulsion type), a hot-melt type pressure-sensitive adhesive composition, and the like. From the viewpoints of coating properties and the degree of freedom in selecting a substrate, a solvent-type or water-dispersed pressure-sensitive adhesive composition can be preferably employed. From the viewpoint of realizing higher adhesive performance, a solvent-type adhesive composition is particularly preferable. Such a solvent-type pressure-sensitive adhesive composition is typically prepared in the form of a solution containing the above-described components in an organic solvent. The organic solvent can be appropriately selected from known or commonly used organic solvents. For example, aromatic compounds such as toluene and xylene (typically aromatic hydrocarbons); acetates such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane, cyclohexane, and methylcyclohexane Any one solvent selected from the group: halogenated alkanes such as 1,2-dichloroethane; ketones such as methyl ethyl ketone and acetylacetone; and a mixed solvent of two or more. Although not particularly limited, it is usually appropriate to prepare the solvent-based pressure-sensitive adhesive composition to a solid content (NV) of 20 to 65% by mass (for example, 25 to 55% by mass). When NV is too low, the manufacturing cost tends to be high, and when NV is too high, handling properties such as coatability may be lowered.

  As a method for obtaining a pressure-sensitive adhesive sheet from the pressure-sensitive adhesive composition, various conventionally known methods can be applied. For example, a method (direct method) of forming a pressure-sensitive adhesive layer by directly applying (typically applying) the pressure-sensitive adhesive composition to a substrate and drying it can be preferably employed. Further, the pressure-sensitive adhesive composition is applied to a surface having good releasability (for example, the surface of a release liner, the back surface of a release support substrate, etc.) and dried to form a pressure-sensitive adhesive layer on the surface. Alternatively, a method (transfer method) of transferring the pressure-sensitive adhesive layer to the substrate may be employed.

  Application of the pressure-sensitive adhesive composition can be performed using a known or conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater. . From the viewpoint of promoting the crosslinking reaction and improving the production efficiency, the pressure-sensitive adhesive composition is preferably dried under heating. For example, a drying temperature of about 40 ° C. to 150 ° C. (typically 40 ° C. to 120 ° C., for example, 50 ° C. to 120 ° C., further 70 ° C. to 100 ° C.) can be preferably employed. The drying time is not particularly limited, but may be about several tens of seconds to several minutes (for example, within about 5 minutes, preferably about 30 seconds to 2 minutes). The pressure-sensitive adhesive layer is typically formed continuously, but may be formed in a regular or random pattern such as a dot or stripe depending on the purpose and application.

  Although not particularly limited, the thickness of the pressure-sensitive adhesive layer is suitably about 3 μm to 150 μm (typically 5 μm to 120 μm, for example, 7 μm to 100 μm). When the adhesive sheet disclosed here is applied to a small test piece that can be carried, the thickness of the adhesive layer can be 2 μm to 100 μm, preferably 5 μm to 75 μm, more preferably 7 μm to 65 μm. (For example, 12 μm to 40 μm). The pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer having the above-described thickness is particularly suitable as a pressure-sensitive adhesive sheet that functions as a member (for example, a spacer) that determines a sample sampling amount in a test piece, for example. In the case where the pressure-sensitive adhesive sheet is a double-sided pressure-sensitive adhesive sheet with a base material, a structure in which a pressure-sensitive adhesive layer having the above thickness is provided on each of both surfaces of the base material is preferable. When the adherend surface has irregularities, the thickness of the pressure-sensitive adhesive layer (at least the first pressure-sensitive adhesive layer in the case of a double-sided pressure-sensitive adhesive sheet) is set to 20 μm or more (for example, 30 μm or more) in consideration of the followability to the unevenness. ).

In the case of a double-sided pressure-sensitive adhesive sheet with a base material in which a first pressure-sensitive adhesive layer is provided on one surface of the base material and a second pressure-sensitive adhesive layer is provided on the other surface of the base material, the thickness of the first pressure-sensitive adhesive layer The thickness of the second pressure-sensitive adhesive layer may be the same or different. When the thickness of the first pressure-sensitive adhesive layer is larger than the thickness of the second pressure-sensitive adhesive layer, for example, the ratio of the thickness T ₁ of the first pressure-sensitive adhesive layer to the thickness T ₂ of the _second pressure-sensitive adhesive layer (T ₁ / T ₂ ) can be 1.5 or more (for example, 2.0 or more, typically 3.5 or more). The double-sided pressure-sensitive adhesive sheet satisfying the above ratio (T ₁ / T ₂ ) is a first pressure-sensitive adhesive surface (the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer) in an embodiment used as a member having an upper limit on the total thickness such as a spacer. ) Is preferably used when higher adhesion is required for the deposition target. Examples of such an adherend include an adherend that is difficult to adhere and an adherend that has irregularities on the bonding surface. For example, in the test piece 30 shown in FIGS. 1 and 2, the adhesion area of the first adhesive surface 11 </ b> A of the double-sided pressure-sensitive adhesive sheet 1 is smaller than the adhesion area of the second adhesive surface 12 </ b> A because the surface to be adhered has irregularities. By applying a double-sided pressure-sensitive adhesive sheet that satisfies the above ratio (T ₁ / T ₂ ) to such a configuration, peeling on the first pressure-sensitive adhesive surface side can be suitably suppressed. First pressure-sensitive adhesive layer of the structure which satisfies the ratio (T 1 _{/ T 2),} in order to have a greater thickness, may be those having excellent conformability to uneven surfaces. The upper limit of the ratio (T ₁ / T ₂ ) is not particularly limited, but can usually be about 8.0 or less (for example, 5.0 or less). A double-sided PSA sheet that has the above-described thicknesses and satisfies the above ratio (T ₁ / T ₂ ) is particularly preferable.

<Base material>
When the technology disclosed herein is applied to a double-sided PSA sheet with a substrate or a single-sided PSA sheet with a substrate, examples of the substrate include polyolefin films such as PE film, PP film, and ethylene-propylene copolymer film. Polyester films such as PET films, plastic films such as polyvinyl chloride films, foam sheets made of foams such as polyurethane foam, PE foam, polychloroprene foam, various fibrous materials (natural fibers such as hemp and cotton, A synthetic fiber such as polyester and vinylon, a semi-synthetic fiber such as acetate, and the like.) A woven fabric and a non-woven fabric (single or mixed paper, such as Japanese paper, fine paper). Foil, metal foil such as copper foil, etc. are appropriately selected and used according to the use of the pressure-sensitive adhesive sheet It is possible. A hydrophilic polymer film such as CMC may be used as the substrate. As the plastic film (typically a non-porous plastic film, which is a concept distinguished from a woven fabric or a non-woven fabric), any of an unstretched film and a stretched (uniaxially stretched or biaxially stretched) film is used. Can also be used. Further, the surface of the substrate on which the pressure-sensitive adhesive layer is provided may be subjected to surface treatment such as application of a primer and corona discharge treatment.

  The thickness of the substrate can be appropriately selected according to the purpose, but is generally about 2 μm to 500 μm (typically 10 μm to 200 μm). When the adhesive sheet with a substrate disclosed herein is applied to a small-sized test piece that can be carried, the thickness of the substrate is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably. 30 μm or less (for example, 20 μm or less). From the viewpoint of imparting sufficient rigidity to the pressure-sensitive adhesive sheet, it is appropriate that the thickness of the substrate is 5 μm or more (for example, 10 μm or more).

  Moreover, it is preferable that the base material disclosed here is colored white. By using a white base material, it is easy to confirm the presence or absence of deposits such as dirt, and it is excellent in cleanliness and can be preferable in terms of hygiene. An adhesive sheet provided with a white base material is preferably used for a test piece used for medical purposes. The white base material also has an advantage that the sample sampled on the test piece is easily visible. When the sample is a blood sample, the sample is particularly excellent in visibility. The degree of whiteness (whiteness) is L * (brightness) defined by the L * a * b * color system, and is preferably 87 or more (for example, 87 to 100), more preferably 90 or more (for example, 90). ~ 100). Each of a * and b * defined by the L * a * b * color system can be appropriately selected according to the value of L *. For example, both a * and b * are preferably in the range of −10 to 10 (more preferably −5 to 5, more preferably −2.5 to 2.5). For example, it is preferable that both a * and b * are 0 or substantially 0. In this specification, L *, a *, and b * defined in the L * a * b * color system are color difference meters (for example, a color difference meter manufactured by Minolta, trade name “CR-200”). It is calculated | required by measuring using "). The L * a * b * color system is a color space recommended by the International Commission on Illumination (CIE) in 1976, and is a color space called the CIE 1976 (L * a * b *) color system. It means that. Further, the L * a * b * color system is defined in JIS Z8729 in the Japanese Industrial Standard.

  Examples of the white colorant used for coloring the base material white include titanium oxide (titanium dioxide such as rutile titanium dioxide and anatase titanium dioxide), zinc oxide, aluminum oxide, silicon oxide, zirconium oxide, and oxidation. Magnesium, calcium oxide, tin oxide, barium oxide, cesium oxide, yttrium oxide, magnesium carbonate, calcium carbonate (light calcium carbonate, heavy calcium carbonate, etc.), barium carbonate, zinc carbonate, aluminum hydroxide, calcium hydroxide, hydroxide Magnesium, zinc hydroxide, aluminum silicate, magnesium silicate, calcium silicate, barium sulfate, calcium sulfate, barium stearate, zinc white, zinc sulfide, talc, silica, alumina, clay, kaolin, titanium phosphate, mica, gypsum, white carbo Inorganic white colorants such as diatomaceous earth, bentonite, lithopone, zeolite, sericite, hydrous halloysite, acrylic resin particles, polystyrene resin particles, polyurethane resin particles, amide resin particles, polycarbonate resin particles, silicone Examples thereof include organic white colorants such as resin particles, urea-formalin resin particles, and melamine resin particles. The amount of the white colorant to be used is not particularly limited, and may be an amount appropriately adjusted so as to impart desired optical characteristics (typically whiteness).

<Total thickness of adhesive sheet>
The total thickness of the pressure-sensitive adhesive sheet (the thickness of the pressure-sensitive adhesive sheet not including the release liner) in the technology disclosed herein is not particularly limited. For example, an adhesive sheet having a thickness of about 20 μm to 500 μm can be used. The thickness of the pressure-sensitive adhesive sheet may be about 30 μm to 300 μm (for example, 40 μm to 200 μm, typically 50 μm to 180 μm). When the adhesive sheet disclosed herein is applied to a small test piece that can be carried, the total thickness of the adhesive sheet is preferably 150 μm or less, more preferably 120 μm or less, and even more preferably 80 μm or less (for example, 60 μm or less). , Typically 50 μm or less). Although the minimum of an adhesive sheet is not specifically limited, In order to exhibit favorable adhesiveness, it is preferable that the total thickness of an adhesive sheet shall be 25 micrometers or more (for example, 40 micrometers or more). The pressure-sensitive adhesive sheet having the above total thickness is particularly suitable as a pressure-sensitive adhesive sheet that functions as a spacer that defines the amount of sample sampling on a test piece, for example. It can cope well with the reduction of the sample sampling amount accompanying the improvement of the analysis accuracy.

<Release liner>
As the release liner disclosed herein, a conventional release paper or the like can be used, and is not particularly limited. For example, as a substrate for a support (exfoliation treatment target) constituting a release liner, various resin films, papers, fabrics, rubber sheets, foam sheets, metal foil, and composites thereof (for example, A sheet having a laminated structure in which an olefin resin is laminated on both surfaces of paper) can be appropriately selected and used. The release treatment can be performed by a conventional method using a known or commonly used release treatment agent (for example, a release treatment agent such as a silicone-based, fluorine-based, or long-chain alkyl-based release agent). For example, a release liner obtained by treating high-quality paper having PE resin laminated on both sides with a silicone-based release agent can be preferably used. In addition, a low-adhesive substrate such as an olefin resin (for example, PE, PP, ethylene-propylene copolymer, PE / PP mixture), a fluorine-based polymer (for example, polytetrafluoroethylene, polyvinylidene fluoride), The surface of the substrate may be used as a release liner without being subjected to a release treatment. Or you may use what performed the peeling process to this low-adhesive base material. The thickness of the release liner is suitably about 25 μm to 200 μm (more preferably 60 μm to 160 μm) from the viewpoint of workability and the like.

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

<Example 1>
(Preparation of adhesive composition)
100 parts of styrene isoprene block copolymer (manufactured by Nippon Zeon Co., Ltd., product name “Quintac 3520”, styrene content 15%, diblock body ratio 78%) as base polymer and 40 parts of terpene phenol resin 30 parts of a terpene resin, 0.75 part of an isocyanate compound (product of Nippon Polyurethane Industry Co., Ltd., product name “Coronate L”), 3 parts of an anti-aging agent, and toluene as a solvent are stirred and mixed. Thus, a rubber pressure-sensitive adhesive composition having an NV of 25% was prepared.
Here, as the terpene phenol resin, the product name “YS Polystar S145” (softening point 145 ° C., hydroxyl value 100 mgKOH / g) manufactured by Yashara Chemical Co., Ltd. and the product name “YS Polystar T145” (softening point 145 ° C.) manufactured by the same company are used. , And a hydroxyl value of 60 mg KOH / g) were used at a mass ratio of 1: 1 so that the total amount was 40 parts. As the terpene resin, a product name “YS Resin PX1150N” (softening point 115 ° C., hydroxyl value of less than 1 mgKOH / g) manufactured by Yasuhara Chemical Co., Ltd. was used. As an anti-aging agent, the product name “IRGANOX CB612” manufactured by BASF (a blend composition of 2: 1 in a mass ratio of the product name “IRGAFOS 168” manufactured by BASF and the product name “IRGANOX 565” manufactured by the company) is used. used.

(Preparation of adhesive sheet)
As a base material, a 13 μm thick PET film on which white printing was applied was prepared. The rubber-based pressure-sensitive adhesive composition obtained above was applied to the first surface of this base material, followed by drying treatment to form a first pressure-sensitive adhesive layer having a thickness of about 30 μm. A release liner subjected to a release treatment with a silicone release agent was bonded to the first pressure-sensitive adhesive layer. Next, the rubber-based pressure-sensitive adhesive composition is applied to the second surface (the surface opposite to the first surface) of the base material, dried, and a second pressure-sensitive adhesive layer having a thickness of about 7 μm is formed. Then, a release liner was bonded in the same manner as in the case of the first pressure-sensitive adhesive layer. In this way, a double-sided PSA sheet having a total thickness of about 50 μm was produced.

<Example 2>
(Preparation of adhesive composition)
95 parts of butyl acrylate, 5 parts of acrylic acid and 200 parts of ethyl acetate as a polymerization solvent were charged into a three-necked flask. After introducing nitrogen gas and stirring for 2 hours to remove oxygen in the polymerization system, 0.2 part of 2,2′-azobisisobutyronitrile (AIBN) was added, and the temperature was raised to 70 ° C. A time polymerization reaction was carried out. In this way, a polymer solution (acrylic polymer ethyl acetate solution) was obtained. To this polymer solution, 25 parts of an acrylic oligomer and 1 part of an isocyanate-based cross-linking agent (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 0.075 part of an epoxy-based cross-linking with respect to 100 parts of the solid content. A liquid acrylic pressure-sensitive adhesive composition was prepared by adding an agent (trade name “Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Inc.) and an appropriate amount of a polymerization solvent and stirring sufficiently.

(Preparation of adhesive sheet)
As a base material, a 13 μm thick PET film on which white printing was applied was prepared. The acrylic pressure-sensitive adhesive composition obtained above was applied to the first surface of the base material and dried to form a first pressure-sensitive adhesive layer having a thickness of about 19 μm. A release liner subjected to a release treatment with a silicone release agent was bonded to the first pressure-sensitive adhesive layer. Next, a second pressure-sensitive adhesive layer having a thickness of about 19 μm was formed on the second surface of the substrate in the same manner as the first surface, and a release liner was bonded thereto. In this way, a double-sided PSA sheet having a total thickness of about 50 μm was produced.

[180 degree peel strength]
A PET film having a thickness of 25 μm was bonded to one pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet according to each example, and this was cut into a size having a width of 20 mm and a length of 150 mm to prepare a measurement sample. In an environment of 23 ° C. and 50% RH, the other adhesive surface of the measurement sample was exposed, and the other adhesive surface was pressed against the surface of the adherend by reciprocating a 2 kg roller once. After leaving this in the same environment for 30 minutes, using a universal tensile compression tester (device name “Tensile Compression Tester, TCM-1kNB” manufactured by Minebea Co., Ltd.), peel angle 180 according to JIS Z0237. The peel strength (N / 20 mm width) was measured under the conditions of a tension rate of 300 mm / min. A stainless steel plate (SUS304 plate) was used as the adherend. The measurement was performed on both the adhesive surface (first adhesive surface) of the first adhesive layer and the adhesive surface (second adhesive surface) of the second adhesive layer. The results are shown in Table 1. In the table, the first adhesive surface and the second adhesive surface are abbreviated as the first surface and the second surface, respectively.

[40 ° C holding power]
The release liner covering one adhesive surface of the double-sided pressure-sensitive adhesive sheet according to each example was peeled off and attached to a PET film having a thickness of 25 μm for backing. The backing adhesive sheet was cut into a size of 10 mm width and 100 mm length to prepare a measurement sample. The release liner covering the other adhesive surface of the measurement sample was peeled off, and a 2 kg roller was reciprocated once on a phenol resin plate as an adherend with a bonding area of 10 mm in width and 20 mm in length for pressure bonding. After the measurement sample attached to the adherend in this manner was dropped in an environment of 40 ° C. and left for 30 minutes, a load of 500 g was applied to the free end of the measurement sample, according to JIS Z0237, The displacement distance (mm) from the first application position of the measurement sample after being left in an environment of 40 ° C. for 1 hour with the load applied was measured. The measurement was performed on both the first adhesive surface and the second adhesive surface. The results are shown in Table 1.

[Liner peeling force]
About the double-sided adhesive sheet which concerns on each example, the peeling strength (liner peeling force) with respect to a peeling liner was measured. That is, the double-sided pressure-sensitive adhesive sheet with a release liner obtained in each example was cut into a size having a width of 50 mm and a length of about 200 mm to prepare a measurement sample. Using a tensile tester, the stress was measured when the release liner was peeled off under the conditions of 23 ° C., RH 50%, peeling angle 180 °, and tensile speed 300 mm / min, and the maximum value was peeled off. The strength (N / 50 mm width) was used. An auxiliary plate was used for measuring the peel strength. The measurement was performed on both the first adhesive surface and the second adhesive surface. The results are shown in Table 1.

[Machinability]
Test pieces shown in FIGS. 1 and 2 were prepared using the double-sided PSA sheet according to each example. Specifically, electrodes 46a, 46b, and 46c made of a carbon material were formed on the surface of the substrate 40 in which a resin layer 44 made of a fluororesin was laminated on the resin plate 42 by a screen printing method. On the surface of the substrate 40, strip-like electrodes having a width of about 0.5 to 1.0 mm and a height of about 15 μm are arranged so as to have an interval of about 0.2 to 2.0 mm. An electrode pattern is formed on the surface of 40. Therefore, the surface of the substrate 40 is an uneven surface in which the electrodes 46a, 46b, and 46c form a convex surface. A coating layer 50 made of a hydrophilic polymer was bonded to the second pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet 1, and then the first pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet 1 was bonded to the surface of the substrate 40 to prepare a test piece laminated structure. The test piece 30 was obtained by processing this into the shape shown in FIG. 1 using a punching machine. The obtained test piece 30 was visually observed, and the case where peeling was not recognized was evaluated as “◯”, and the case where peeling was recognized was evaluated as “x”. The results are shown in Table 1.

  As shown in Table 1, the double-sided pressure-sensitive adhesive sheet according to Example 1 having an adhesive strength (180 degree peel strength) of the first pressure-sensitive adhesive surface of 12 N / 20 mm or more (specifically, 20 N / 20 mm or more) Sometimes peeling did not occur and processability was excellent. On the other hand, the double-sided pressure-sensitive adhesive sheet according to Example 2 having an adhesive strength of the first pressure-sensitive adhesive surface of less than 12 N / 20 mm was observed to be peeled off during processing. More specifically, in FIG. 1, peeling was observed on the first adhesive surface 11 </ b> A around the capillary portion 60 of the test piece 30. From this result, it can be seen that the pressure-sensitive adhesive sheet having an adhesive force of a predetermined value or more has good adhesion applicable to the test piece. Moreover, since the double-sided pressure-sensitive adhesive sheet according to Example 1 was excellent in holding power at 40 ° C. and the liner peeling force was not more than a predetermined value, the pressure-sensitive adhesive sheet used for the specimen for sample analysis had good holding power and liner removal. It turns out that it can have a property.

  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, 2, 3 Adhesive Sheet 11 First Adhesive Layer 11A First Adhesive Surface 12 Second Adhesive Layer 12A Second Adhesive Surface 15 Base Material 21, 22 Release Liner 30 Test Piece

Claims (6)

An adhesive sheet used in a biosensor that is detachably connected to a biological sample measuring instrument ,
Comprising an adhesive layer constituting at least one surface of the adhesive sheet;
The pressure-sensitive adhesive layer is
As a base polymer, a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound,
As a tackifier resin, including terpene phenol resin,
The pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet having an adhesive strength of 12 N / 20 mm or more. The pressure-sensitive adhesive sheet according to claim 1 , wherein the base polymer is a styrenic block copolymer. Before SL tackifying resin has a softening point contains a high softening point resin or higher 120 ° C., the pressure-sensitive adhesive sheet according to claim 1 or 2. The pressure-sensitive adhesive sheet according to claim 3 , comprising the terpene phenol resin as the high softening point resin. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the tackifying resin contains a low softening point resin having a softening point of less than 120 ° C. Both surfaces provided with a base material, a first pressure-sensitive adhesive layer as the pressure-sensitive adhesive layer provided on one surface of the base material, and a second pressure-sensitive adhesive layer provided on the other surface of the base material The pressure-sensitive adhesive sheet according to any one of claims 1 to 5 , wherein the pressure-sensitive adhesive sheet is configured as a pressure-sensitive adhesive sheet.

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