JP6454091B2 - Adhesive products - Google Patents

Description

  The present invention relates to an adhesive product using a rubber adhesive. Specifically, the present invention relates to a pressure-sensitive adhesive product including two pressure-sensitive adhesive members configured to be separable.

  Generally, a pressure-sensitive adhesive (also referred to as a pressure-sensitive adhesive; the same shall apply hereinafter) is in the form of a soft solid (viscoelastic body) in a temperature range near room temperature and has a property of easily adhering to an adherend by pressure. Taking advantage of such properties, pressure-sensitive adhesives are widely used in various industrial fields such as home appliances, automobiles, and office automation equipment as bonding means with good workability and high adhesion reliability. A typical composition of the pressure-sensitive adhesive includes a composition containing a polymer exhibiting rubber elasticity at room temperature as a base polymer. For example, Patent Documents 1 to 3 describe an adhesive containing a styrene block copolymer such as a styrene isoprene styrene block copolymer or a styrene butadiene styrene block copolymer.

JP 2001-123140 A JP 2001-342441 A Japanese Patent Laid-Open No. 10-287858

  By the way, some adhesive products are cut into an appropriate size and configured so as to be separable into a plurality of pieces, but are integrally handled without being separated until used. Such an adhesive product separates one adhesive member and the other adhesive member configured to be separable at the stage of use. However, in adhesive products using rubber adhesives with strong self-adhesive properties, the pressure-sensitive adhesives of each pressure-sensitive adhesive member block each other, and when the pressure-sensitive adhesive members are pulled apart, stringing occurs and resistance increases due to blocking (typically In some cases, inconveniences such as an increase in resistance at the time of pickup occur. If the occurrence of such an inconvenience can be prevented or suppressed, the handleability is improved and fine processing is possible, which is beneficial.

  The present invention has been made in view of the above-described conventional circumstances, and is caused by blocking of the adhesive between two adhesive members configured to be separable despite the use of the rubber-based adhesive. It is an object of the present invention to provide an adhesive product in which the occurrence of inconvenience is prevented or suppressed.

  According to this invention, the adhesive product provided with the sheet-like base material and the adhesive layer provided in the at least one surface of this base material is provided. The adhesive product includes a first adhesive member and a second adhesive member each having the base material and the adhesive layer. Further, the first adhesive member and the second adhesive member are configured to be separable from each other by being cut from at least one direction, and the respective cut end faces formed by cutting are opposed to each other. . And the said adhesive is a rubber-type adhesive, and the said base material is a nonwoven fabric base material. According to said structure, the blocking of the adhesive in the cutting | disconnection area | region of an adhesive product is prevented or suppressed by using a nonwoven fabric as a base material in the adhesive product using a strong self-adhesive rubber adhesive. Accordingly, the pressure-sensitive adhesive product can avoid or suppress the occurrence of inconvenience such as stringing of the pressure-sensitive adhesive due to blocking of the pressure-sensitive adhesive, and can be excellent in handleability during use and capable of fine processing. .

  In a preferred embodiment of the pressure-sensitive adhesive product disclosed herein, the pressure-sensitive adhesive product has a blocking strength measured by the following method of less than 1.0 N. Here, the blocking strength measurement method is: Prepare a test piece in which a peelable support is bonded to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer; store the test piece at 50 ° C. for 3 days; then, the peelable support From the pressure-sensitive adhesive product, only the first pressure-sensitive adhesive member is peeled off at a temperature of 23 ° C., a relative humidity (RH) of 50%, a pulling speed of 300 mm / min, and a peeling angle of 180 degrees; Is measured as blocking strength. As described above, the pressure-sensitive adhesive product in which the blocking strength of the pressure-sensitive adhesive (in other words, the resistance due to the blocking) is suppressed to a predetermined value or less preferably prevents or suppresses the occurrence of inconvenience due to the pressure-sensitive adhesive blocking. Therefore, the handling property at the time of use (for example, pickup workability when removing the release liner from the adhesive member) can be further improved. In this specification, “pickup” typically means an operation of removing a release liner from an adhesive product in use.

  In a preferable embodiment of the pressure-sensitive adhesive product disclosed herein, the 180-degree peeling adhesive strength to the stainless steel plate is 15 N / 20 mm or more. As described above, an adhesive product exhibiting a peeling adhesive strength of a predetermined value or more has a strong adhesive strength. According to the configuration disclosed herein, it is possible to suitably prevent or suppress the occurrence of inconvenience due to the strong adhesive force and the blocking of the adhesive.

In a preferred embodiment of the pressure-sensitive adhesive product disclosed herein, the rubber-based pressure-sensitive adhesive contains a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound as a base polymer. Moreover, in the preferable one aspect | mode of the adhesive product disclosed here, the said nonwoven fabric base material has a basic weight of 10-30 g / m < ² >, thickness of 10-150 micrometers, and a bulk density of 0.20-0.50 g /. cm ³ .

  Moreover, according to this invention, the adhesive product with a release liner provided with one of the adhesive products disclosed here and the release liner which protects the adhesive surface of this adhesive layer is provided. The technique disclosed here can be suitably implemented in a mode including a release liner.

  According to the present invention, there is further provided an adhesive sheet as the first adhesive member or the second adhesive member separated from any of the adhesive products disclosed herein. The pressure-sensitive adhesive sheet includes the base material and the pressure-sensitive adhesive layer provided on at least one surface of the base material. The pressure-sensitive adhesive sheet having such a configuration prevents or suppresses the occurrence of inconvenience due to the blocking of the pressure-sensitive adhesive, and therefore has a quality capable of fine processing and has excellent pressure-sensitive adhesive properties (for example, peeling pressure-sensitive adhesive). Strength and repulsion resistance).

It is sectional drawing which shows typically the structure of the adhesive product (double-sided adhesive sheet with a base material) which concerns on one Embodiment. It is sectional drawing which shows typically the structure of the adhesive product (single-sided adhesive sheet with a base material) which concerns on other embodiment. It is sectional drawing which shows the structure of an adhesive product typically, Comprising: (a) is a figure which shows an example of the state which cut | disconnected the said adhesive product, (b) shows an example of the state after the cutting | disconnection of the said adhesive product FIG. It is a schematic diagram explaining the method of a blocking strength measurement test. It is a schematic diagram explaining the method of a repulsion resistance evaluation test. 2 is a cross-sectional SEM image of the test piece according to Example 1 after cutting. 6 is a cross-sectional SEM image of the test piece according to Example 2 after cutting.

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 may be 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 product of the present invention 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 as described above. . 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 pressure-sensitive adhesive in the technology disclosed herein can be grasped as a solid component of the pressure-sensitive adhesive composition or a constituent component of the pressure-sensitive adhesive layer.
The “base polymer” of the pressure-sensitive adhesive is a main component (that is, a component occupying more than 50% by mass of the polymer) of a polymer (a polymer exhibiting rubber elasticity in a temperature range near room temperature) contained in the pressure-sensitive adhesive. ).

  In this specification, “a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound” refers to a monovinyl-substituted aromatic compound as a main monomer (a copolymer component exceeding 50% by mass; the same shall apply hereinafter). A polymer having at least one segment (hereinafter also referred to as “A segment”) and 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.

  In this specification, 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).

In this specification, 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).
Further, the ratio of the diblock body in 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 chromatograph 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.

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

  As shown in FIG. 2, 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 15. The adhesive product 2 which is a sticky adhesive sheet can also be applied. For example, as shown in FIG. 2, the adhesive product 2 before use has a release liner in which the surface (adhesive surface) 11 </ b> A of the adhesive layer 11 is a release surface at least on the surface (front surface) on the adhesive layer 11 side. 21 may be the protected form. Alternatively, the release liner 21 is omitted, and the adhesive 15 is wound on the second surface 15B of the substrate 15 by winding the adhesive product 2 using the substrate 15 having the second surface 15B as the release surface. It may be in a form protected by contact.

  In a preferred embodiment disclosed herein, the adhesive product includes at least a first adhesive member and a second adhesive member. The specific configuration will be described. In the adhesive product 1, as shown in FIG. 3A, the adhesive surface 11 </ b> A of the first adhesive layer 11 is affixed to a resin film 30 that is an adhesion target of the adhesive surface 11 </ b> A. Further, the pressure-sensitive adhesive surface 12 </ b> A of the second pressure-sensitive adhesive layer 12 is disposed in a form protected by the release liner 21.

  In this embodiment, the pressure-sensitive adhesive product 1 is cut from at least one direction (preferably only in one direction) along the thickness direction of the pressure-sensitive adhesive product 1 using an appropriate cutting means C. In this embodiment, the cutting means C cuts from the surface of the resin film 30 to the adhesive surface 12A of the second adhesive layer 12 of the adhesive product 1, and the release liner 21 is not completely cut. In other words, the cutting means C penetrates the pressure-sensitive adhesive product (double-sided pressure-sensitive adhesive sheet) 1 including the base material 15 and the pressure-sensitive adhesive layers (the first pressure-sensitive adhesive layer 11 and the second pressure-sensitive adhesive layer 12) disposed on both surfaces thereof. However, it does not penetrate to the back surface of the release liner 21 (surface opposite to the pressure-sensitive adhesive layer side surface). Thereby, the adhesive product 1 provided with the 1st adhesive member 5 and the 2nd adhesive member 6 which were comprised so that separation | separation was mutually possible is obtained. The first pressure-sensitive adhesive member 5 and the second pressure-sensitive adhesive member 6 thus obtained have the form of a pressure-sensitive adhesive sheet (typically a double-sided pressure-sensitive adhesive sheet) in the same manner as the pressure-sensitive adhesive product 1. The cutting means used for cutting is not particularly limited, and may be performed using a cutting means such as a known or conventional cutting machine. Moreover, the timing of cutting is not particularly limited, and may be before the one adhesive surface of the adhesive product is attached to the adherend (the resin film 30 in the above embodiment). Further, the pressure-sensitive adhesive product may be provided with third and fourth pressure-sensitive adhesive members by the same cutting as described above or a conventionally known cutting.

  The adhesive product 1 is cut in the thickness direction. Therefore, the 1st adhesive member 5 and the 2nd adhesive member 6 are each equipped with the base material 15 and the adhesive layer (the 1st adhesive layer 11 and the 2nd adhesive layer 12) on both surfaces. Further, the release liner 21 that supports the first adhesive member 5 and the second adhesive member 6 is not cut (partial cutting is acceptable). For this reason, the first adhesive member 5 and the second adhesive member 6 are supported by the release liner 21, and the cut end faces CS1 and CS2 formed by cutting are opposed to each other. At this time, the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive member 5 (specifically, the pressure-sensitive adhesive of the first pressure-sensitive adhesive layer 11 and the pressure-sensitive adhesive of the second pressure-sensitive adhesive layer 12) is the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive member 6. (Specifically, the pressure-sensitive adhesive of the first pressure-sensitive adhesive layer 11 and the pressure-sensitive adhesive of the second pressure-sensitive adhesive layer 12). In this state, after the first adhesive member 5 and the second adhesive member 6 are handled integrally (typically after being stored or the like), they are separated (typically a release liner). 21) and attached to an adherend (not shown) according to the purpose.

  The pressure-sensitive adhesive product 1 including the first pressure-sensitive adhesive member 5 and the second pressure-sensitive adhesive member 6 as described above is cut as shown in FIG. Moreover, the adhesive which comprises the 1st adhesive member 5 and the adhesive which comprises the 2nd adhesive member 6 may contact again. In that case, depending on the contact state, blocking of adhesives may arise. However, by adopting the configuration of the pressure-sensitive adhesive product disclosed herein, it is possible to prevent or suppress the occurrence of inconvenience due to the blocking of the pressure-sensitive adhesive as described above. Hereinafter, the configuration of the pressure-sensitive adhesive product that can prevent or suppress the occurrence of inconvenience due to the blocking of the pressure-sensitive adhesive as described above will be described in detail.

  In addition, below, although the case where the technique disclosed here is applied to a double-sided adhesive sheet with a base material is demonstrated as a main example, it is not the intention which limits the application object of the said technique. Moreover, although this invention prevents or suppresses the generation | occurrence | production of the inconvenience resulting from blocking of an adhesive, the adhesive of the 1st adhesive member and the adhesive of a 2nd adhesive member which are mutually opposed are contacting. Any of the embodiments or the non-contact embodiments (for example, the non-contact manner in which the pressure-sensitive adhesives are in contact with each other) can be included in the technology disclosed herein. In other words, in the technique disclosed here, the adhesive of the first adhesive member and the adhesive of the second adhesive member do not need to be non-contact. As is clear from the examples described later (for example, comparison with Examples 1 and 2, especially FIGS. 6 and 7), it is an inconvenience due to blocking of the adhesive (typically increased resistance during stringing and pick-up). This is because the presence / absence of occurrence is considered to be largely dependent not only on whether or not the adhesives are in contact with each other but also on the contact state between the adhesives. In addition, although not particularly limited, the interval (average interval) between the cut end surfaces facing each other of the first adhesive member and the second adhesive member is, for example, 0.5 mm or less (typically 0.1 mm or less). ). Moreover, the aspect which the cutting | disconnection end surfaces of the 1st adhesive member and the 2nd adhesive member are separated so that the blocking of the said adhesive cannot occur is grasped | ascertained as the object of the technique disclosed here.

<Base polymer>
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive product disclosed herein (which can also be grasped as the solid content of the pressure-sensitive adhesive composition) is a rubber-based pressure-sensitive 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. 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). With such a block copolymer, a higher performance adhesive product 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.

  The block copolymer in the technique disclosed herein has a diblock ratio of 30% by mass or more (more preferably 40% by mass or more, more preferably 50%) from the viewpoint of adhesive strength (peel strength) to the adherend. % By mass or more, particularly preferably 60% by mass or more, and typically 65% by mass or more). 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.

<Styrenic block copolymer>
In a preferred embodiment of the technology disclosed herein, the base polymer is a styrenic block copolymer. 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. As the styrenic block copolymer used in the technique disclosed herein, the diblock ratio is 30% by mass or more (more preferably 40% by mass or more) from the viewpoint of adhesive strength (peeling strength) to the adherend. More preferably 50% by mass or more, particularly preferably 60% by mass or more, typically 65% by mass or more) can be preferably used. 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. A styrene block having a diblock ratio of 60 to 85% by mass from the viewpoint of balancing a plurality of adhesive properties (repulsion resistance, high temperature cohesiveness, peel strength, etc.) in a balanced manner by applying the technology disclosed herein. A copolymer is preferable, and 70-85 mass% (for example, 70-80 mass%) styrene-type block copolymer is more preferable.

  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 usually 10% by mass or more (more preferably more than 10% by mass, for example, 12% by mass or more) is preferred. 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. A styrene block having a styrene content of 12% by mass or more and less than 20% by mass from the viewpoint of better exerting the effect of applying the technology disclosed herein (for example, the effect of improving repulsion resistance and peel strength). A copolymer can be preferably employed.

<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.

Adhesives disclosed herein, as the tackifying resin, a softening point preferably contains a tackifier resin T _H than 120 ° C.. From the standpoint of repulsion resistance and high-temperature cohesive strength, the softening point of the tackifier 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 tackifier resin T _H, usually, is suitably 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 tackifier resin here 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 increases after reaching 40 ° C. after heating has started must be 5.0 ° C. plus / 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.

<Tackifying resin _THR1 >
In a preferred embodiment of the art disclosed herein, the tackifier resin T _H has an aromatic ring and a hydroxyl value may contain tackifier resin T _HR1 or less 30 mgKOH / g. This can effectively improve the repulsion resistance and high temperature cohesion. 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. Among 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) It can be employed as _THR1 .

Here, as the value of the hydroxyl value, 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.

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).

In carrying out the technology disclosed herein, it is not necessary to clarify the reason why the high temperature cohesion is improved by using the tackifier resin _THR1 , but the following may be considered. That is, since the tackifier resin _THR1 has an aromatic ring, it is also referred to as a domain (hereinafter referred to as “hard domain”) formed by a collection of hard segments having a monovinyl-substituted aromatic compound as a main monomer. Easily compatible with styrene domains in polymers. When the high softening point tackifying resin _THR1 is compatible with the hard domain, the heat resistance of the pseudo-crosslinking by the hard domain can be improved. This is considered to contribute to the improvement of the high-temperature cohesiveness of the pressure-sensitive adhesive.
Here, as a general trend, the tackifier resin T _H of the high-softening point is less compatible than the tackifying resin T _L of the low softening point. Therefore, high tackifier resin T _H of the hydroxyl value may have an aromatic ring, small amount capable compatible with the hard domain or uniformly within the hard domain undergoes microphase separation in hard domain It is easy to spoil the nature. Therefore, according tackifier resin T _H is difficult to appropriately exhibit the effect of improving the high-temperature cohesive strength. This is more remarkable in a composition in which the hard segment content in the base polymer (for example, the styrene content in the styrenic block copolymer) is relatively small.
The tackifier resin _THR1 in the technology disclosed herein has a high softening point and a hydroxyl value limited to 30 mgKOH / g or less, so a composition with a relatively small hard segment content (for example, styrene content) It is considered that the high-temperature cohesiveness is effectively improved due to the compatibility with the hard domain.

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 repulsion resistance and high temperature cohesiveness, the amount of the tackifying resin _THR1 used relative to 100 parts by mass of the base polymer is usually preferably 5 parts by mass or more and more preferably 10 parts by mass or more. In addition, from the viewpoint of achieving a high level of both repulsion resistance, high temperature cohesiveness, and peel strength, 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. Is preferably 80 parts by mass or less (for example, 60 parts by mass or less). 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 It is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more from the viewpoint of repulsion resistance and high temperature aggregation. The amount of the tackifier resin T _HR1 for 1 part by weight of styrene component in the block copolymer, for example, can be 10 parts by mass or less, and a peel strength and repelling resistance and high temperature cohesive high levels From the viewpoint of achieving both, 7 parts by mass or less is preferable, and 5 parts by mass or less is more preferable.

<Tackifying resin _THR2 >
In another preferred embodiment of the pressure-sensitive adhesive disclosed herein, the tackifying resin _TH contains an aromatic ring and contains a tackifying resin _THR2 substantially free of an isoprene unit, a terpene skeleton, and a rosin skeleton. Can do. This can effectively improve the repulsion resistance and the high temperature cohesion. 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 tackifier resin _THR2 has an aromatic ring that is easily compatible with a hard domain (eg, styrene domain) of a block copolymer (eg, styrene block copolymer) of a monovinyl-substituted aromatic compound and a conjugated diene compound. And an isoprene unit, a terpene skeleton and a rosin skeleton having high affinity with a soft segment (a segment having a conjugated diene compound as a main monomer). For this reason, the tackifier resin _THR2 blended in the pressure-sensitive adhesive having the block copolymer as a base polymer is concentrated (miscible) in the hard domain, and thereby heat resistance of pseudo-crosslinking by the hard domain. Efficiency can be improved efficiently. Further, by substantially not containing an isoprene unit, a terpene skeleton, and a rosin skeleton, an adverse effect that may occur when the high-softening point tackifier resin _THR2 is too compatible with the soft segment (decrease in peel strength, hard domain) Etc.) can be avoided or suppressed. As a result, an adhesive product in which high-temperature cohesion and peel strength are compatible at a high level can be realized.

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. Repulsion resistance, in view of the high-temperature cohesive strength, usually, the amount of tackifier resin T _HR2 for 100 parts by mass of the base polymer is preferably at least 5 parts by weight, more preferably at least 10 parts by weight. In addition, from the viewpoint of achieving a high level of both repulsion resistance, high temperature cohesiveness, and peel strength, 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. Is preferably 80 parts by mass or less (for example, 60 parts by mass or less). 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 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, from a viewpoint of making high temperature cohesion and peeling strength compatible at a high level. 7 parts by mass or less is preferable, and 5 parts by mass or less is more preferable.

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.

The technique disclosed here can be preferably implemented also in an aspect in which tackifying resin _THR1 and / or _THR2 and another tackifying resin are used in combination according to the purpose and application. Alternatively, it may be preferably implemented in an embodiment in which neither of the tackifying resins T _HR1 and T _HR2 is included and only another tackifying resin is used as the tackifying resin. Alternatively, the technology disclosed herein may be implemented in a mode that does not include a tackifier resin.

<Tackifying resin T _L >
As a suitable example of the aspect containing other tackifying resin, the aspect containing tackifying resin _TL with a softening point of less than 120 degreeC is mentioned. According to such an embodiment, for example, an adhesive product with better peel strength can be realized.
The lower limit of the softening point of the tackifier resin _TL is not particularly limited. Usually, those having a softening point of 40 ° C. or higher (typically 60 ° C. or higher) can be preferably used. From the viewpoint of achieving a high level of both repulsion resistance, high temperature cohesiveness and peel strength, usually, a tackifying resin _TL having a softening point of 80 ° C. or higher (more preferably 100 ° C. or higher) and lower than 120 ° C. is preferably employed. be able to. Especially, use of tackifying resin _TL whose softening point is 110 degreeC or more and less than 120 degreeC is preferable.

The hydroxyl value and structure of the tackifier 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 tackifying resin _TL . For example, a composition in which the main component of the tackifying resin _TL (that is, a component occupying more than 50% by mass of the tackifying 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, etc. can be preferably employed. From the viewpoint of adhesive strength and compatibility, an embodiment in which the main component of the tackifying resin _TL is a terpene resin (for example, β-pinene polymer) is preferable. The terpene resin may be substantially all of the tackifying resin _TL (for example, 95% by mass or more).

<Tackifying resin _THO >
As a preferred example of embodiment including other tackifying resins, it does not correspond to at least one of tackifying resin T _HR1 and T _HR2 tackifier resin T _{H (may} be referred to as the "tackifier resin T _HO".) The aspect containing is mentioned. The use of tackifier resin T _HO, for example, may help to improve performance such as repulsion resistance and constant load peeling property.

As the tackifying resin _THO , for example, terpene phenol resin, rosin phenol resin, polymerized rosin, esterified product of polymerized rosin and the like can be used. Such tackifying resin _THO can be used individually by 1 type or in combination of 2 or more types. As a preferable embodiment, there is an embodiment in which one or two or more terpene phenol resins are used as the tackifying resin _THO . For example, more than 25% by weight of the tackifier resin T _HO (more preferably at least 30 wt%) of embodiments is preferably a terpene phenolic resin. Least 50 wt% of the tackifier resin _{T HO} (more preferably 70 mass% or more, more preferably 80 mass% or more, for example 90 wt% or more) may be a terpene phenol resin, substantially tackifier resin _{T HO} In particular, all (for example, 95% by mass or more) may be a terpene phenol resin. A terpene phenol resin having a softening point of 120 ° C. or higher and 200 ° C. or lower (typically 130 ° C. or higher and 180 ° C. or lower, eg, 135 ° C. or higher and 170 ° C. or lower) can be preferably used.

Art disclosed herein, for example, as a tackifier resin _{T HO,} a hydroxyl value may be preferably carried out in a manner containing 80 mg KOH / g or more (e.g. 90 mgKOH / g or higher) tackifying resin _{(T HO1).} The hydroxyl value of the tackifying resin _THO1 is typically 200 mgKOH / g or less, preferably 180 mgKOH / g or less (for example, 160 mgKOH / g or less). As the value of the hydroxyl value, a value measured by the potentiometric titration method defined in the above-described JIS K0070: 1992 can be adopted. Specifically, a value obtained by applying the above-described method for measuring a hydroxyl value can be adopted as the value of the hydroxyl value. According to the pressure-sensitive adhesive containing the tackifying resin _THO1 , a higher-performance pressure-sensitive adhesive product can be realized. That is, according to the pressure-sensitive adhesive containing the tackifying resin _THO1 , a pressure-sensitive adhesive product that achieves high-temperature cohesion and other characteristics (for example, repulsion resistance and constant load peeling characteristics) at a higher level can be realized.

As the tackifier resin _THO1 , one of the above-mentioned various tackifier resins having a hydroxyl value of a predetermined value or more can be used alone or in combination of two or more. In a preferred embodiment, at least a terpene phenol resin is used as the tackifier resin _THO1 . The terpene phenol resin is preferable because the hydroxyl value can be arbitrarily controlled by the copolymerization ratio of phenol. It is preferable that 50 mass% or more (more preferably 70 mass% or more, for example, 90 mass% or more) of the tackifying resin _THO1 is a terpene phenol resin, and substantially all (for example, 95 to 100 mass%, further 99-100 mass%) may be a terpene phenol resin.

Adhesives disclosed herein, as the tackifier resin _{T HO,} a hydroxyl value of 0 or 80 mg KOH / g of less than tackifier resin _{(T HO2)} may contain. Tackifier resin _{T HO2} may be used in place of the tackifier resin _{T HO1,} it may be used in combination with a tackifier resin _{T HO1.} As a preferred embodiment, the hydroxyl value is a tackifier resin _{T HO1} above 80 mg KOH / g, it includes embodiments comprising a tackifier resin _{T HO2.} As the tackifier resin _THO2 , those having a hydroxyl value in the above range among the various tackifier resins described above can be used singly or in appropriate combination of two or more. 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 tackifier resin _{T HO1} of, hydroxyl value 40 mg KOH / g or more It can preferably be implemented in an embodiment comprising a combination of less than 80 mg KOH / g tackifying resin _THO2 . In this _case, the relationship between the amount of _{T HO1} and _{T HO2,} for example, the mass ratio _{(T HO1:} T _HO2) is 1: 5 to 5: can be set to be 1, and usually It is appropriate to set the range of 1: 3 to 3: 1 (for example, 1: 2 to 2: 1). As a preferred _{embodiment, T HO1,} T _HO2 is mentioned embodiment each a terpene phenol resin.

  When using a 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 from the viewpoint of realizing a good balance between repulsion resistance, high-temperature cohesiveness, and peel strength. Usually, 20 parts by mass or more is appropriate, 30 parts by mass or more is preferable, and 40 parts by mass or more (eg, 50 parts by mass or more) is more preferable. 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.

In the art disclosed herein, when using a tackifier resin T _H, is not particularly limited, the total amount of tackifier resin T _H for 100 parts by mass of the base polymer (i.e., a softening point of 120 ° C. or more tackifying resin From the viewpoint of high-temperature cohesiveness, repulsion resistance and the like, the total amount can be, for example, 10 parts by mass or more, and preferably 20 parts by mass or more (for example, 25 parts by mass or more). Further, from the viewpoint of peel strength and low temperature properties (e.g., low temperature peel strength), the content of the tackifier resin T _H for 100 parts by mass of the base polymer is usually suitably 120 parts by weight or less, preferably 100 parts by weight More preferably, it is 80 parts by mass or less (for example, 60 parts by mass or less). The total amount of tackifier resin T _H for 100 parts by mass of the base polymer by 55 parts by mass or less (for example, 50 parts by mass or less), higher peel strength can be achieved.

In embodiments including a tackifier resin T _L, the total amount of tackifier resin T _L for 100 parts by mass of the base polymer is not particularly limited, for example, it can be 10 parts by mass or more, at least 15 parts by weight in terms of peel strength Preferably, 20 parts by mass or more is more preferable. Further, the total amount of the tackifying 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 preferably 70 parts by mass or less (for example, from the viewpoint of high temperature aggregation and repulsion resistance) 60 parts by mass or less) is more preferable. It is good also considering content of tackifying resin _TL as 50 mass parts or less (for example, 40 mass parts or less).
The ratio for which tackifying resin _TL accounts among all the tackifying resin contained in the adhesive disclosed here is not specifically limited. The said ratio can be 10-70 mass%, for example, and 20-50 mass% is preferable normally.

When the adhesive as disclosed herein comprises a tackifier resin T _H and tackifier resin T _L, the relation of their usage, T _L: Mass ratio of T _H 1: 5 to 3: 1 (more It is preferable to set so that it is 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 such an embodiment, a higher performance adhesive product can be realized.
The ratio of tackifier resin T _H of the total tackifying resin 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 normally.

In the art disclosed herein, when using a tackifier resin T _HR1, is not particularly limited, the proportion of the tackifier resin T _HR1 of the total tackifying resin contained in the adhesive disclosed herein For example, it can be 1-100 mass%, Usually, 5-80 mass% is preferable, and 10-70 mass% is more preferable. The same applies to the proportion of the tackifying resin _{THR2 in} the total tackifying resin contained in the pressure-sensitive adhesive when the tackifying resin _THR2 is used.

<Isocyanate compound>
The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer disclosed herein may contain an isocyanate compound. According to such a pressure-sensitive adhesive composition, a high-performance pressure-sensitive adhesive product (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 in such a range, a pressure-sensitive adhesive product having a particularly excellent performance balance can be realized.

<Other ingredients>
The pressure-sensitive adhesive disclosed herein may contain one or more polymers other than the base polymer, if necessary. Such polymers may be various polymers such as acrylics, polyesters, urethanes, polyethers, silicones, polyamides, and fluorines known in the field of pressure-sensitive adhesives. When the pressure-sensitive adhesive contains a polymer other than the base polymer, the amount of the polymer used is usually suitably 50 parts by mass or less, preferably 30 parts by mass or less, more preferably 100 parts by mass of the base polymer. Is 10 parts by mass or less (for example, 5 parts by mass or less). The technology disclosed herein is preferably implemented in an embodiment in which the pressure-sensitive adhesive does not substantially contain a polymer other than the base polymer (for example, an embodiment in which the content per 100 parts by mass of the base polymer is 0 to 1 part by mass). obtain.

  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 such a pressure-sensitive adhesive, a pressure-sensitive adhesive product 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, an adhesive product with better 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 30 to 65% by mass (for example, 40 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 an adhesive product from the 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. The direct method is preferable from the viewpoint of the impregnation property of the adhesive to the substrate, and the transfer method is preferable from the viewpoint of improving the surface smoothness and improving the adhesive strength.

  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. Usually, 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). Then, you may provide an additional drying process as needed. 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 usually about 4 μm to 150 μm (typically 20 μm to 120 μm, for example, 30 μm to 100 μm). In the case where the pressure-sensitive adhesive product 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 side of the base material is preferable.

<Base material>
The base material applied to the technique disclosed here is a base material composed of a nonwoven fabric (in other words, a nonwoven fabric base material). Conventionally, when a rubber adhesive (particularly an adhesive containing a block copolymer of a monovinyl-substituted aromatic compound such as a styrene isoprene block copolymer and a conjugated diene compound as a base polymer) is applied to a nonwoven fabric substrate, Due to the low impregnation property of the adhesive, it has been considered difficult to obtain high-performance adhesive properties that make better use of the advantages of the rubber adhesive on a practical level. However, unlike the conventional common sense, the technology disclosed herein uses a non-woven fabric as a base material, so that the adhesive product using a rubber adhesive having a strong self-adhesive property is used in the cutting region of the adhesive product. Prevent or suppress blocking of the adhesive. The application of the nonwoven fabric substrate also contributes to an improvement in flexibility and hand cutting property of the adhesive product.

  Nonwoven fabrics include, for example, pulps such as wood pulp, natural fibers such as cotton and hemp; polyester fibers such as polyethylene terephthalate (PET) fibers, rayon, vinylon, acetate fibers, polyvinyl alcohol (PVA) fibers Nonwoven fabric composed of chemical fibers (synthetic fibers) such as polyamide fiber, polyolefin fiber, and polyurethane fiber; Nonwoven fabric composed of two or more kinds of fibers having different materials can be used. Especially, the nonwoven fabric comprised from a nonwoven fabric comprised from a pulp and hemp (for example, hemp pulp), a PET fiber, etc. are preferable from a viewpoint of the impregnation property of an adhesive, and repulsion resistance.

As the nonwoven fabric (nonwoven fabric substrate) in the technology disclosed herein, one having a basis weight of about 30 g / m ² or less (for example, 25 g / m ² or less, typically 20 g / m ² or less) can be preferably used. . Such a nonwoven fabric having a basis weight is suitable for producing a pressure-sensitive adhesive product that is lightweight and has excellent adhesive performance. From the viewpoint of repulsion resistance, a nonwoven fabric having a basis weight of less than 18 g / m ² (for example, 16 g / m ² or less, typically 15 g / m ² or less) is preferable. From the viewpoint of improving the strength of the substrate itself, the basis weight is preferably 10 g / m ² or more (for example, 12 g / m ² or more, typically 13 g / m ² or more).

  In the technique disclosed herein, it is appropriate that the thickness of the nonwoven fabric substrate is usually about 150 μm or less. From the viewpoint of sufficiently impregnating the entire substrate with the pressure-sensitive adhesive, the thickness is preferably 100 μm or less (for example, 70 μm or less, typically 60 μm or less). In consideration of the handleability at the time of producing an adhesive product, the thickness is preferably 10 μm or more (for example, 25 μm or more, typically 30 μm or more). From the viewpoint of repulsion resistance, the thickness is preferably 30 μm to 60 μm (for example, 35 μm to 50 μm, typically 40 μm to 45 μm).

The bulk density of the nonwoven fabric substrate (which can be calculated by dividing the basis weight by the thickness) is usually about 0.20 to 0.50 g / cm ³ and is preferably 0.25 to 0.40 g / cm. It is preferably about ³ . When the bulk density is within the above range, the substrate itself has an appropriate strength, and good pressure-sensitive adhesive impregnation is obtained. From the viewpoint of repulsion resistance, it is particularly preferable to use a nonwoven fabric substrate having a bulk density of about 0.25 to 0.40 g / cm ³ (for example, 0.30 to 0.35 g / cm ³ ).

  The nonwoven fabric substrate disclosed herein has at least two of the basis weight, thickness and bulk density in the above preferred ranges (for example, basis weight and thickness, more preferably all of basis weight, thickness and bulk density). It is preferable to satisfy. Thereby, an adhesive product in which a plurality of adhesive properties (for example, repulsion resistance, high temperature cohesiveness, peel strength, etc.) are highly balanced can be realized.

  In addition to the constituent fibers as described above, the nonwoven fabric substrate contains resin components such as starch (eg, cationized starch), polyacrylamide, viscose, polyvinyl alcohol, urea formaldehyde resin, melamine formaldehyde resin, and polyamide polyamine epichlorohydrin. Can do. The resin component may function as a paper strength enhancer for the nonwoven fabric substrate. The strength of the nonwoven fabric substrate can be adjusted by using such a resin component as necessary. The nonwoven fabric substrate in the technology disclosed herein may contain other additives that are commonly used in the field of nonwoven fabric production, such as a yield improver, a drainage agent, a viscosity modifier, and a dispersant, as necessary. .

<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). For example, a release liner obtained by treating a high-quality paper having polyethylene (PE) resin laminated on both sides with a silicone release agent can be preferably used. Low adhesion groups such as olefin resins (eg, PE, polypropylene (PP), ethylene-propylene copolymer, PE / PP mixture), fluorine polymers (eg, polytetrafluoroethylene, polyvinylidene fluoride), etc. The material may be used as a release liner without subjecting the surface of the substrate 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 50 μm to 200 μm (more preferably 60 μm to 160 μm) from the viewpoint of workability and the like.

<Application>
The pressure-sensitive adhesive product disclosed herein is useful for joining between members in various OA equipment, home appliances, automobiles, and the like (for example, fixing use of various parts in such products). In particular, an elastic resin sheet (for example, a plastic film having a thickness of about 0.05 mm to 0.2 mm) is made of acrylonitrile butadiene styrene copolymer (ABS), high impact polystyrene (HIPS), polycarbonate (PC) and ABS. It is suitable for applications such as bonding to a resin casing such as a polymer blend (PC / ABS) or an aluminum casing. Examples of products having such joints include mobile devices such as toner cartridges, printers, notebook computers, mobile phones and smartphones, and tablet-type mobile terminals.

<Characteristics of adhesive products>
In a preferred embodiment, the pressure-sensitive adhesive product disclosed herein has a blocking strength measured by the above-described method (more specifically, the blocking strength is measured according to the blocking strength measurement method described in the examples described later) of less than 1.0 N. It is preferable to show 0.8N or less (for example, 0.4N or less, typically 0.3N or less).
The blocking strength here is substantially a force necessary for picking up the first adhesive member (pickup force). Of this pickup force, the adhesive surface of the first adhesive member is separated from the peelable support. Since the contribution of the force required to do this is usually very small, in practice it can be considered that the pick-up strength is determined by the force required to separate the cut end surface of the first adhesive member from the cut end surface of the second adhesive member. it can.
The force required to separate the cut end surface of the first adhesive member from the cut end surface of the second adhesive member is not substantially affected by the width of the first adhesive member. Therefore, although the blocking strength is measured by [N / 10 mm] using the first adhesive member having a width of 10 mm in the examples described later, the present invention is not limited to this, and the first adhesive member having a width different from 10 mm is used. The blocking strength may be measured. In addition, when the adhesive product has other members such as a third adhesive member in a form adjacent to the first adhesive member, after blocking and separating the other members so that only the first adhesive member and the second adhesive member are present, blocking is performed. What is necessary is just to measure intensity | strength.

  In a preferred embodiment, the pressure-sensitive adhesive product disclosed herein is pressure-bonded to an aluminum cylinder as an adherend and is subjected to an environment of 70 ° C. and 80% RH in the repulsion resistance evaluation method described in Examples described later. The floating distance measured after standing for 12 hours may be 5 mm or less. In a more preferred embodiment, the floating distance is 3 mm or less (for example, 1.8 mm or less, typically 1.2 mm or less).

  In another preferable embodiment, the pressure-sensitive adhesive product disclosed herein has a 2 kg roller reciprocated once on the surface of a stainless steel plate (SUS304 plate) as an adherend in an environment of 23 ° C. and 50% RH. After pressure bonding and leaving to stand for 30 minutes, 180 degree peeling adhesive strength measured at a tensile speed of 300 mm / min according to JIS Z0237 (180 degree peeling adhesive strength against stainless steel plate or SUS peeling adhesive strength) But typically 10N / 20mm or more. The 180-degree peeling adhesive strength is preferably 15 N / 20 mm or more, and more preferably 20 N / 20 mm or more. The adhesive product according to a particularly preferable embodiment may have the 180-degree peeling adhesive strength (N / 20 mm width) of 25 N / 20 mm or more (more preferably 28 N / 20 mm or more).

  In a preferred embodiment, the pressure-sensitive adhesive product disclosed herein is bonded to a stainless steel plate (SUS304 plate) as an adherend by reciprocating a 2 kg roller once with a bonding area of 10 mm in width and 20 mm in length. In a heat resistant holding force measurement in which a load of 500 g is applied and left in the same environment for 1 hour after being dropped in an environment of ℃ and left for 30 minutes, the adhesive product peels off from the adherend after the load is applied. The time to fall can be one hour or more. An adhesive product that satisfies the above characteristics is excellent in high-temperature cohesion.

  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. Each characteristic in the following description was measured or evaluated as follows.

<Experimental example 1>
(Example 1)
[Preparation of pressure-sensitive 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 a base polymer, aromatic petroleum resin (JX Nippon Mining & Energy Corporation, product name “Nisseki Neopolymer 150”, softening point 155 ° C., hydroxyl value less than 1 mg KOH / g) 20 parts, terpene phenol resin 40 parts, terpene resin 30 parts, isocyanate compound (Nippon Polyurethane Industry Co., Ltd., product name “Coronate L”) 0.75 part based on solid content, 3 parts anti-aging agent, and toluene as a solvent are stirred and mixed, and a 50% NV pressure-sensitive adhesive composition. Was prepared.
Here, as the terpene phenol resin, the trade name “YS Polystar S145” (softening point 145 ° C., hydroxyl value 100 mg KOH / g) manufactured by Yashara Chemical Co., Ltd. , 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.

[Production of adhesive products]
A sheet-like release liner was prepared by laminating a PE layer having a thickness of 25 μm on one surface of a high-quality paper and performing a release treatment with a silicone release agent thereon. The pressure-sensitive adhesive composition obtained above was applied to the release-treated surface of this release liner and dried to form a pressure-sensitive adhesive layer. The obtained pressure-sensitive adhesive layer was transferred to the first surface of the substrate. Similarly, an adhesive layer was also formed on the second surface of the substrate. As the substrate, a pulp nonwoven fabric having a basis weight of 14 g / m ² , a thickness of 42 μm, and a bulk density of 0.33 g / cm ³ was used. Thus, an adhesive product according to Example 1 (double-sided adhesive sheet having a total thickness of 140 μm) was produced.

(Example 2)
A pressure-sensitive adhesive product according to Example 2 was produced in the same manner as in Example 1 except that a polyethylene terephthalate (PET) film having a thickness of 12 μm was used as the substrate.

[Measurement of blocking strength]
The release liner covering one adhesive surface of the pressure-sensitive adhesive product (double-sided pressure-sensitive adhesive sheet) according to each example was peeled off and attached to a resin film for backing. This backed double-sided PSA sheet was cut into a size of 20 mm in width and 100 mm in length. As shown in FIG. 4, the long double-sided PSA sheet is formed from the film side in the thickness direction of the PSA sheet at a center line L parallel to the longitudinal direction of the PSA sheet at the center in the width direction. The double-sided adhesive sheet was cut. The above cutting operation was performed using a known cutting machine. Thereby, the test piece 3 comprised so that the 1st adhesion member 5 and the 2nd adhesion member 6 were separable on the boundary of the cutting area | region formed by cutting | disconnection was obtained. In this test piece 3, the cut end faces of the first adhesive member 5 and the second adhesive member 6 were opposed to each other. In the cutting operation, the cutter of the cutting machine penetrates the film and the double-sided pressure-sensitive adhesive sheet, but does not penetrate the release liner (peelable support) 21 that covers the other pressure-sensitive adhesive surface. The test piece 3 thus obtained was stored at 50 ° C. for 3 days. Thereafter, only the first pressure-sensitive adhesive member 5 of the test piece 3 is peeled from the release liner 21 under conditions of a temperature of 23 ° C., 50% RH, a tensile speed of 300 mm / min, and a peeling angle of 180 degrees (arrow direction in FIG. 4). (Pickup operation). The peel strength at this time was measured as blocking strength [N] ([N / 10 mm] in this example). The results are shown in Table 1. The storage at 50 ° C. for 3 days before the first adhesive member is peeled may be changed to storage at 23 ° C. for 7 days. In this case, the present inventors have confirmed that almost the same result can be obtained.

[Observation of blocking state]
Moreover, in the measurement of the blocking strength, the state when the first adhesive member was picked up was visually observed and evaluated according to the following criteria.
○: The first adhesive member could be picked up smoothly from the release liner.
X: During pick-up operation, stringing was recognized between the first adhesive member and the second adhesive member.
The results are shown in Table 1.
Moreover, the SEM (Scanning Electron Microscope) image of the test piece cross section after the said cutting operation is shown to FIG.

  As shown in Table 1, in the pressure-sensitive adhesive product according to Example 1 using a non-woven fabric as a base material, a phenomenon caused by blocking of the pressure-sensitive adhesive (typically threading of the pressure-sensitive adhesive) was not recognized. On the other hand, in the pressure-sensitive adhesive product according to Example 2 using a PET film as a base material, the pressure-sensitive adhesive of the first pressure-sensitive adhesive member and the pressure-sensitive adhesive of the second pressure-sensitive adhesive member are blocked, and the first pressure-sensitive adhesive member is picked up from the release liner. When doing so, stringing was recognized between the second adhesive member and the second adhesive member. Moreover, about the adhesive layer of the 1st adhesive member of Example 2, the phenomenon where the edge part by the side of the 2nd adhesive member turned up was seen. This is probably because strong stringing occurred due to blocking of the adhesive. The results of the blocking strength test well show an increase in the peel strength due to blocking of the pressure-sensitive adhesive represented by the stringing. Further, as is clear from the comparison between FIG. 6 and FIG. 7, an example in which a resin film (specifically, a PET film) is used as a base material as compared with the adhesive product according to Example 1 in which a nonwoven fabric is used as a base material. In the pressure-sensitive adhesive product according to No. 2, it was considered that the area where the cut adhesive layers on both sides were in contact again was large, which caused inconvenience due to blocking of the pressure-sensitive adhesive. From these results, in the case where an adhesive product using a rubber adhesive having a strong self-adhesive property is used in a mode having a first adhesive member and a second adhesive member that are separable from each other by cutting, a nonwoven fabric substrate It can be seen that using is effective in preventing or suppressing the occurrence of inconvenience due to blocking of the adhesive. In addition, although not specifically shown, when the adhesive products according to Examples 1 and 2 were measured for the adhesive strength against SUS peeling by the above-described method, both showed an adhesive strength of 28 N / 20 mm or more. Moreover, when the heat-resistant holding force measurement was implemented by the above-mentioned method about Example 1, 2, the adhesive product affixed on the to-be-adhered body was hold | maintained, without dropping for 1 hour or more.

<Experimental example 2>
(Example 3)
[Preparation of pressure-sensitive 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, an adhesive composition having an NV of 50% was prepared.
Here, as the terpene phenol resin, the trade name “YS Polystar S145” (softening point 145 ° C., hydroxyl value 100 mg KOH / g) manufactured by Yashara Chemical Co., Ltd. , 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.

[Production of adhesive products]
A PE layer having a thickness of 25 μm was laminated on one surface of a fine paper, and a sheet-like release liner was prepared on which a release treatment with a silicone release agent was performed. The pressure-sensitive adhesive composition obtained above was applied to the release-treated surface of this release liner and dried to form a pressure-sensitive adhesive layer. The obtained pressure-sensitive adhesive layer was transferred to the first surface of the substrate. Similarly, an adhesive layer was also formed on the second surface of the substrate. As the base material, a PET nonwoven fabric having a basis weight of 14 g / m ² , a thickness of 40 μm, and a bulk density of 0.35 g / cm ³ was used. In this way, an adhesive product according to Example 3 (double-sided adhesive sheet having a total thickness of 140 μm) was produced.

(Example 4)
A pressure-sensitive adhesive product according to Example 4 was prepared in the same manner as in Example 3 except that a nonwoven fabric of 100% hemp pulp having a basis weight of 23 g / m ² , a thickness of 76 μm, and a bulk density of 0.30 g / cm ³ was used as the base material. .

(Example 5)
A pressure-sensitive adhesive product according to Example 5 was produced in the same manner as in Example 3 except that a pulp nonwoven fabric having a basis weight of 14 g / m ² , a thickness of 42 μm, and a bulk density of 0.33 g / cm ³ was used as the base material.

(Example 6)
A pressure-sensitive adhesive product according to Example 6 was produced in the same manner as in Example 3 except that a nonwoven fabric of 100% hemp pulp having a basis weight of 14 g / m ² , a thickness of 50 μm, and a bulk density of 0.28 g / cm ³ was used as the base material. .

(Example 7)
A pressure-sensitive adhesive product according to Example 7 was produced in the same manner as Example 3 except that a pulp-based nonwoven fabric having a basis weight of 14 g / m ² , a thickness of 27 μm, and a bulk density of 0.52 g / cm ³ was used as the base material.

(Example 8)
A pressure-sensitive adhesive product according to Example 8 was produced in the same manner as Example 3 except that a nonwoven fabric of 100% pulp having a basis weight of 14 g / m ² , a thickness of 28 μm, and a bulk density of 0.50 g / cm ³ was used.

(Example 9)
A pressure-sensitive adhesive product according to Example 9 was produced in the same manner as in Example 5 except that the pressure-sensitive adhesive composition prepared in Example 1 was used.

(Example 10)
An adhesive product was prepared in Example 10 in the same manner as in Example 3 except that a PET film having a thickness of 12 μm was used as the substrate.

[Repulsion resistance evaluation]
Using a cylinder made of aluminum having a diameter of 24 mm as an adherend, the repulsion resistance of the pressure-sensitive adhesive product (double-sided pressure-sensitive adhesive sheet) according to each example was evaluated. That is, as shown in FIG. 5, one adhesive surface 4A of the adhesive product 4 was attached to the PET film 42 having a thickness of 300 μm and lined. The backing adhesive product 4 was cut into a size of 10 mm in width and 40 mm in length to produce a test piece 44. In an environment of 23 ° C. and 50% RH, the other adhesive surface 4B of the test piece 44 is 2 kg so that the longitudinal direction of the test piece 44 is the circumferential direction of the adherend (aluminum cylinder) 46 The roller was reciprocated once and pressed. The adherend 46 was used after washing with ethyl alcohol in advance. After this was left in an environment of 70 ° C. and 80% RH for 12 hours, it was observed whether both ends 44A and 44B in the longitudinal direction of the test piece 44 were peeled off from the surface of the adherend 46 and floated. In this case, the floating distance (the length of the portion where the test piece 44 lifted from the surface of the adherend 46) was measured. When both ends of the test piece were floating, the average value of the floating distances at both ends was taken as the floating distance of the test piece. The results are shown in Table 2 and Table 3.

As shown in Table 2, all of the pressure-sensitive adhesive products according to Examples 3 to 8 using a non-woven fabric as the base material exhibited good repulsion resistance. Especially, basic weight, thickness, and bulk density are in a predetermined range (specifically, basic weight is 14 g / m ² , thickness is 40 to 50 μm, bulk density is 0.28 to 0.35 g / cm ³ ). In the pressure-sensitive adhesive products according to Examples 3, 5, and 6 using the nonwoven fabric, a better result was obtained with a lift distance of 2 mm or less in the repulsion resistance evaluation. In particular, the pressure-sensitive adhesive product according to Example 5 exhibited the most excellent repulsion resistance among Examples 3 to 8. Furthermore, as shown in Table 3, the adhesive product according to Example 9 using a rubber-based adhesive compounded with a tackifying resin having a softening point of 120 ° C. or higher and a hydroxyl value of 30 mgKOH / g or less is a PET film as a substrate. It showed repulsion resistance comparable to that of Example 10 used. From these results, a pressure-sensitive adhesive product exhibiting excellent repulsion resistance can be obtained by using a combination of a rubber-based pressure-sensitive adhesive containing a tackifying resin having a softening point of 120 ° C. or higher and a hydroxyl value of 30 mgKOH / g or less and a nonwoven fabric base material. It turns out that it is obtained. Although not particularly shown, when the adhesive products according to Examples 3 to 10 were measured for the adhesive strength against SUS peeling by the above-described method, all showed an adhesive strength of 28 N / 20 mm or more. Moreover, when the heat-resistant holding force measurement was implemented by the above-mentioned method about Example 9, the adhesive product affixed on the to-be-adhered body was hold | maintained, without dropping for 1 hour or more.

  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 Adhesive products (adhesive sheets)
5 First adhesive member 6 Second adhesive member 11 First adhesive layer 12 Second adhesive layer 15 Base material 21 Release liner

Claims (9)

An adhesive product used to join mobile device parts,
A sheet-like base material, and an adhesive layer provided on at least one surface of the base material ,
Each includes a first adhesive member and a second adhesive member provided with the substrate and the adhesive layer,
The first pressure-sensitive adhesive member and the second pressure-sensitive adhesive member are configured to be separable from each other by being cut from at least one direction, and each cut end surface formed by cutting is opposed to each other,
The pressure-sensitive adhesive is a rubber-based pressure-sensitive adhesive,
The substrate is a nonwoven substrate;
The said nonwoven fabric base material is an adhesive product which is a nonwoven fabric base material comprised from the material selected from a pulp and hemp, or a nonwoven fabric base material comprised from a polyethylene terephthalate fiber. The pressure-sensitive adhesive product according to claim 1, wherein the blocking strength measured by the following method is less than 1.0 N.
[Method of measuring blocking strength]
A test piece in which a peelable support is bonded to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer is prepared. The specimen is stored at 50 ° C. for 3 days. Thereafter, only the first pressure-sensitive adhesive member of the pressure-sensitive adhesive product is peeled off from the peelable support under the conditions of a temperature of 23 ° C., a relative humidity of 50%, a tensile speed of 300 mm / min, and a peeling angle of 180 degrees. The peeling strength at this time is measured as a blocking strength.   The pressure-sensitive adhesive product according to claim 1 or 2, wherein a 180-degree peeling adhesive strength to the stainless steel plate is 15 N / 20 mm or more.   The pressure-sensitive adhesive product according to any one of claims 1 to 3, wherein the rubber-based pressure-sensitive adhesive contains a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound as a base polymer.   The pressure-sensitive adhesive product according to claim 4, wherein a diblock body ratio of the block copolymer is 60% by mass or more. The nonwoven substrate has a basis weight of 10 to 30 g / ^{m 2,} a thickness of 10 to 150 m, and a bulk density of 0.20~0.50g / cm ^3, any one of claims 1 to 5 Adhesive product as described in.   The pressure-sensitive adhesive product according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer has a thickness of 20 µm to 120 µm.   The pressure-sensitive adhesive product according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive contains a tackifier resin having a softening point of 120 ° C or higher. A pressure-sensitive adhesive product with a release liner, comprising the pressure-sensitive adhesive product according to any one of claims 1 to 8 and a release liner that protects the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer.