JP2006348234A - Pressure-sensitive adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive tape which contains selected particles in a pressure-sensitive layer without a special adhesive, and can surely be cut, when punched, while sufficiently ensuring an adhesive force to an article to be transferred. <P>SOLUTION: (1) This pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a support, is characterized by containing scaly particles in the pressure-sensitive adhesive layer. (2) The pressure-sensitive adhesive tape mentioned in the paragraph (1), wherein the Mohs hardness of the scaly particles is ≥4.5. (3) The pressure-sensitive adhesive tape mentioned in the paragraph (1) or (2), wherein the thickness, average length and average width of the scaly particles are 1 to 15 μm, 40 to 400 μm, and 40 to 400 μm, respectively, and the ratio of the average length to the average width is 1:1 to 3. (4) The pressure-sensitive adhesive tape mentioned in one of the paragraphs (1), (2), and (3), wherein the scaly particles are contained in the pressure-sensitive adhesive layer in an amount of 0.5 to 5 wt.%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure sensitive adhesive tape having a pressure sensitive adhesive layer on a support.

  A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a support is highly convenient due to the property of instantaneous adhesion, and is used in a wide range of applications in the industry.

  Such a pressure-sensitive adhesive tape is often used by being punched into some shape as a member processed product.

  However, when punching out a pressure-sensitive adhesive tape, the presence of the pressure-sensitive adhesive layer may cause problems such as adhesion to the punching blade and sticking of glue. As a result, there are problems such as workability in product assembly, yield, and product quality. In the electronic and information fields such as computers and mobile phones, pressure-sensitive adhesive tapes are used as process materials and auxiliary materials. Pressure sensitive adhesive tapes used for such applications need to be punched into smaller and complex shapes.

  Therefore, in the prior art, an acrylic pressure-sensitive adhesive composition (Patent Document 1) is disclosed that includes a combination of specific monomer components in the pressure-sensitive adhesive layer.

  However, in these methods, due to the combination of specific monomer components, the adherend is limited, and sufficient adhesive force cannot be obtained. Moreover, the cutting force of the pressure-sensitive adhesive layer was poor, and the punching workability was insufficient.

JP 2004-359827 A

  The present invention is a pressure-sensitive adhesive tape that can be surely cut at the time of punching while ensuring sufficient adhesion to the transfer object by selecting particles to be added to the pressure-sensitive adhesive layer without using a special adhesive. It is an issue to provide.

  As a result of diligent research on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape, the present inventor has determined that the pressure-sensitive adhesive layer is blended with an appropriate amount of scaly particles, and the punching process is performed while sufficiently securing the adhesive force to the transfer target. Sometimes, the entire flat surface of the scaly particles breaks through the membrane and contributes to the cutting of the pressure-sensitive adhesive layer.Therefore, the cutting area is large and the time until the membrane is completely cut is shortened. The headline and the present invention have been completed.

That is, the present invention provides the following pressure-sensitive adhesive tape.
(1) A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a support, wherein the pressure-sensitive adhesive layer contains scaly particles.
(2) The pressure-sensitive adhesive tape according to (1), wherein the scale-like particles have a Mohs hardness of 4.5 or more.
(3) The above (1) or wherein the scale-like particles have a thickness of 1 to 15 μm, the average length and average width of the particles are 40 to 400 μm, and the ratio of the average width to the average length is 1: 1 to 3 The pressure-sensitive adhesive tape according to item (2).
(4) The pressure-sensitive adhesive tape according to any one of (1) to (3), wherein the pressure-sensitive adhesive layer contains 0.5 to 5% by weight of scaly particles.

  The pressure-sensitive adhesive tape of the present invention is excellent in adhesion to an adherend, and the pressure-sensitive adhesive layer can be reliably cut at a predetermined position, and punching is easy.

  In the pressure-sensitive adhesive tape of the present invention, an organic polymer film support and a paper support are preferably used as the support. As the organic polymer film support, various film supports such as a polyester film, a polycarbonate film, a polymethyl methacrylate film, a polypropylene film, and a polyimide film can be used. As the paper support, high-density paper such as glassine paper, coated paper, craft paper, high-quality paper, and the like can be used.

  The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer in the pressure-sensitive adhesive tape of the present invention is not particularly limited, and a general pressure-sensitive adhesive composition can be used, but an acrylic copolymer and a crosslinking agent. As an essential component, if necessary, a compound containing a tackifier resin can be suitably used.

  As the acrylic copolymer, one or more of (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the alkyl group and another monomer having an ethylenically unsaturated bond capable of copolymerization are used. A copolymer with 1 type (s) or 2 or more types is mentioned.

  Examples of the (meth) acrylic acid alkyl ester include n-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, and isooctyl. (Meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, etc. are mentioned.

  Examples of the monomer having a copolymerizable ethylenically unsaturated bond include acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, cyclohexyl (meth) acrylate, Styrene, α-methylstyrene, vinyl acetate, N-vinyl-2-pyrrolidone, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, acrylic acid, methacrylic acid, itacon An acid, fumaric acid, etc. are mentioned. In the production of the acrylic copolymer, a monomer having a functional group capable of reacting with a crosslinking agent described later (for example, a monomer having a carboxyl group) is used as an essential component as a monomer having a copolymerizable ethylenically unsaturated bond. To do.

  As tackifying resins, rosin, rosin phenol resins, and rosin resins such as ester compounds and metal salts thereof, terpene polymers, terpene phenol resins, terpene resins such as aromatic modified terpene resins, styrene resins, Coumarone-indene resin, alkylphenol resin, xylene resin, C5 petroleum resin, C9 petroleum resin, alicyclic hydrogenated resin, etc. are mentioned. When used by blending with a polymer, natural resin-based rosin resins and terpene resins exhibiting good adhesion and initial tackiness to adherends such as paper and various films are preferably used.

  In the pressure-sensitive adhesive composition of the present invention, examples of the crosslinking agent used for crosslinking the acrylic copolymer include hexamethylene diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 2-chloro-1,4- Diisocyanate compounds such as phenyl diisocyanate, trimethylhexamethylene diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, biuret-type trimers of these diisocyanate compounds, isocyanurate-type trimers, isocyanate-based crosslinking agents such as triisocyanate, epoxy-based Examples thereof include a cross-linking agent, a melamine-based cross-linking agent, a metal chelate-based cross-linking agent, and an adduct of a polyol such as trimethylol propane, which can be appropriately selected and used.

  In the pressure-sensitive adhesive composition, scaly particles are added in order to improve punching processability. The thickness of the scaly particles is preferably 1 to 15 μm. When the thickness is less than the above range, the punching workability is inferior, and when it exceeds the above range, the adhesive strength is reduced. In addition, the average length and average width of the scaly particles are preferably 40 to 400 μm in consideration of film breakability. When the average length and the average width are less than the above ranges, the punching processability is inferior. Further, in consideration of punching workability, the ratio of the average width to the average length of the scaly particles is preferably 1: 1 to 3. Here, the average length and the average width of the scaly particles means that both the average length and the average width of the scaly particles are in the range of 40 to 400 μm. The length and width of the scaly particles are the longest side of the flat surface of the particle, and the height in the direction perpendicular to the longest side is the width. Furthermore, the hardness of the particles is preferably a Mohs hardness of 4.5 or more in consideration of punching workability. If the Mohs hardness is less than 4.5, the punching processability is poor.

As flaky particles, flaky glass particles, flaky mica, flaky synthetic mica, calcined mica,
Magicite, kanemite, montmorillonite, saponite, laponite, hectorite, barcumulite, kaolinite, halloysite, kanemite, macatite, iraite, agadiaite, kenyanite, sericite, calcined sericite, bentonite, zonotrite, smectite, vamorite, scaly graphite , Boron nitride, silica-X, silica-Y and the like. Examples of silica-X and silica-Y include flaky silica described in JP-A No. 2001-163613. In addition, there are particles obtained by processing metal powder into a scale shape, and examples of the material include gold, silver, aluminum, copper, brass, chromium, tin, lead, indium and the like.

As needed, what surface-treated the scaly particle | grains can be used. Examples of the surface treatment method include those obtained by hydrolyzing Si—O—Si bonds on the particle surface with a weak alkali, or those obtained by surface treatment with a coupling agent such as tetraethoxysilane.
Examples of the weak alkali include ammonia and triethanolamine, but are not limited thereto. A desirable reaction pH range is pH 13 to 9, particularly pH 11 to 9.

  Among the scaly particles, scaly glass particles that can be freely processed in size and have low cost and transparency are particularly preferable. Since the scale-like glass particles have a Mohs hardness of 4.5 or more, they are also excellent in die cutting properties. Generally, scaly glass particles are called glass flakes.

  The amount of the scaly particles is 0.5 in the total amount of the pressure-sensitive adhesive layer (the total amount of the pressure-sensitive adhesive composition in terms of solid content) from the viewpoint of the adhesiveness of the pressure-sensitive adhesive layer, punching workability, and particle dispersibility. It is preferably ˜5% by weight. When the blending amount of the flaky particles is less than the above range, the punching processability is inferior, and when the blending amount exceeds the above range, the dispersibility of the particles is deteriorated and the adhesive strength is lowered.

  The pressure-sensitive adhesive layer may be colored by adding an inorganic or organic colorant to the pressure-sensitive adhesive composition as long as the adhesiveness, tackiness, film breakage, etc. are not impaired.

  The thickness of the pressure-sensitive adhesive layer is preferably in the range of 5 to 200 μm, more preferably in the range of 10 to 100 μm, taking into consideration the adhesive force to the paper surface, the holding power and the film breakability. The pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition using, for example, a bar coater, roll coater, gravure coater, knife coater, die coater, comma coater, lip coater or the like.

  Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto. In the following, “part” means part by weight, and the coating amount, the number of parts, the mixing ratio, etc. are all expressed in terms of solid content.

Example 1
(Manufacture of adhesive composition)
First, 98 parts of an acrylic adhesive (“SK Dyne 801B” manufactured by Soken Chemical Co., Ltd., containing an acrylic copolymer and a tackifier resin) and a crosslinking agent (“Curing Agent L-” manufactured by Soken Chemical Co., Ltd.) 45 ") 2 parts were mixed to obtain a base acrylic pressure-sensitive adhesive composition. The final pressure-sensitive adhesive is obtained by mixing 5 parts of scaly glass particles (Mohs hardness: 6.5, thickness: 5 μm, average length: 150 μm, average width: 100 μm) with 95 parts of this base adhesive composition. An agent composition was obtained.

  The thickness, length, and width of the scaly particles were determined by observing the particles with a metal microscope. The average length and average width were determined as average values for 50 particles arbitrarily selected (hereinafter the same).

(Manufacture of pressure-sensitive adhesive tape)
The pressure-sensitive adhesive composition was applied on a polyester film 100 μm with a comma coater to a thickness of 20 μm (when dried), and dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive tape.

Example 2
0.5 parts of scaly glass particles (Mohs hardness: 6.5, thickness: 5 μm, average length: 150 μm, average width: 100 μm) are mixed with 99.5 parts of the base pressure-sensitive adhesive composition in Example 1. A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that.

Example 3
Except for mixing 3 parts of scaly glass particles (Mohs hardness: 6.5, thickness: 4 μm, average length: 300 μm, average width: 250 μm) to 97 parts of the base pressure-sensitive adhesive composition in Example 1, A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1.

Example 4
Example 1 except that 3 parts of scaly mica (Mohs hardness: 3, thickness: 2 μm, average length: 50 μm, average width: 35 μm) were mixed with 97 parts of the base adhesive composition in Example 1. In the same manner, a pressure-sensitive adhesive tape was obtained.

Example 5
Except for mixing 5 parts of scaly glass particles (Mohs hardness: 6.5, thickness: 5 μm, average length: 15 μm, average width: 10 μm) to 95 parts of the base pressure-sensitive adhesive composition in Example 1, A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1.

Comparative Example 1
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that 3 parts of granular fluororesin particles (average particle size: 3.5 μm) were mixed with 97 parts of the base pressure-sensitive adhesive composition in Example 1.

Comparative Example 2
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that 97 parts of the base pressure-sensitive adhesive composition in Example 1 was mixed with 3 parts of granular polyethylene particles (average particle size: 20 μm).

Comparative Example 3
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that 97 parts of the base pressure-sensitive adhesive composition in Example 1 was mixed with 3 parts of spherical silicone particles (average particle size: 12 μm).

Comparative Example 4
Except that 97 parts of the base pressure-sensitive adhesive composition in Example 1 were mixed with 3 parts of acicular glass particles (Mohs hardness: 6.5, diameter: 10 μm, average length: 70 μm), the same as in Example 1 A pressure sensitive adhesive tape was obtained.

(Measurement of physical properties)
Each pressure-sensitive adhesive tape obtained as described above was cured for 7 days in a constant temperature and humidity chamber at 20 ° C. and 65% RH, and then the initial adhesive strength and punching workability were measured. The results are shown in Table 1.

Each physical property was measured under the following conditions.
(1) Initial adhesive strength According to JIS Z0237, a test piece was bonded to a SUS304 steel plate, and the 180 ° peel strength after 20 minutes was measured. The tensile speed was 300 mm / min. The value of the initial adhesive strength (gf / 25 mm) shown in Table 1 is an average value for 10 test pieces. The initial adhesive strength (gf / 25 mm) was determined according to the following criteria.
A: 1,000 gf / 25 mm or more; Extremely good B: 800 gf / 25 mm or more, less than 1,000 gf / 25 mm; Good Δ: 650 gf / 25 mm or more, less than 800 gf / 25 mm; Slightly inferior x: Less than 650 gf / 25 mm;

(2) Punching workability A 43-degree Thomson blade was used as the cutting blade, the cut surface was observed, and the thread drawing state was evaluated.
◎: No stringing is observed at all ◯: Slightly stringing is observed Δ: Slightly stringing is observed ×: Much stringing is observed

Claims (4)

A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a support, wherein the pressure-sensitive adhesive layer contains scaly particles. The pressure-sensitive adhesive tape according to claim 1, wherein the scale-like particles have a Mohs hardness of 4.5 or more. The feeling according to claim 1 or 2, wherein the thickness of the scaly particles is 1 to 15 µm, the average length and the average width of the particles are 40 to 400 µm, and the ratio of the average width to the average length is 1: 1 to 3. Pressure adhesive tape. The pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer contains 0.5 to 5% by weight of scaly particles.