JP4698189B2 - Adhesive tape - Google Patents

Description

  The present invention relates to an adhesive tape (including a sheet). More specifically, the present invention relates to an adhesive tape for medical use that can be used for, for example, a sports tape, a surgical tape, and a dressing, that is, a medical adhesive tape.

  The medical adhesive tape is directly applied to the human skin for a certain period of time. For this reason, the medical adhesive tape is generally required to repeatedly expand and contract with the movement of the user while being applied to the user's skin (see, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-233545)). . If a medical adhesive tape with poor elasticity and poor skin followability is applied, the tape will not be able to smoothly follow the expansion and contraction of the skin, causing unnecessary discomfort such as a feeling of touching the skin. This is because it may cause mechanical irritation and induce skin irritation.

  Moreover, moisture permeability and breathability are calculated | required by the medical adhesive tape. When a medical pressure-sensitive adhesive tape having poor moisture permeability or air permeability is applied, sweating of the applied skin is inhibited, the skin may be peeled off, and skin irritation may be induced. In particular, more sweating than usual is assumed during sports. Therefore, for example, Patent Document 2 (Japanese Patent Publication No. 2003-509121) includes a base material and an adhesive layer provided in a pattern on the base material surface with a non-coating space of about 25% or less. An adhesive article is disclosed. In particular, in Patent Documents 3 to 5 (Japanese Utility Model Laid-Open Nos. 4-110723, 10-328231, and 10-33741, respectively), at least one surface of a base material having air permeability or moisture permeability is disclosed. An adhesive tape having an adhesive layer provided in strips or undulations is disclosed to achieve air permeability from the gaps between the strips. FIG. 1 and FIG. 2 are top views respectively showing an adhesive tape having the above-mentioned strip-like adhesive pattern and wavy adhesive pattern (in the figure, the hatched portion indicates a region having an adhesive pattern). In the figure, the non-hatched part indicates an area having no adhesive pattern.) However, these adhesive tapes have the following problems.

(1) The above adhesive tape lacks the ability to follow the skin. This is because the human skin generally has a polygonal pattern such as a triangle or a quadrangle on the surface and can be expanded and contracted substantially regardless of the direction. It is because it is not formed in consideration of.
(2) When the pressure-sensitive adhesive tape of FIG. 1 is peeled along the direction X, the pressure-sensitive adhesive portions and the gap portions appear alternately, and smooth peeling cannot be performed. This causes excessive mechanical irritation to the skin. Such mechanical stimulation at the time of peeling appears as pain to the user and causes skin irritation. This is the same when the adhesive tape of FIG. 2 is peeled along the directions of P, Q and R.
(3) In addition, when the user is applying the tape shown in FIG. 1, mechanical stimulation that causes a sense of discomfort, such as a feeling of touch on the skin, is used when the adhesive tape expands or contracts in the Y direction. May receive. In the X direction, there are alternating gaps between the adhesive strips where the adhesive is not applied, so it is difficult to inhibit the stretchability of the skin, but in the Y direction, the adhesive is continuous and the skin stretches. It is for inhibiting. This is the same when the adhesive tape of FIG. 2 is expanded and contracted along the S direction.

JP 2002-233545 A Special Table 2003-509121 Japanese Utility Model Publication 4-110723. JP 10-328231 A JP 10-33741 A

  Therefore, the object of the present invention is to not only reduce the mechanical stimulus that can follow the skin and cause discomfort during application, but it is also difficult to generate a mechanical stimulus from any direction. It is to provide a medical adhesive tape that can reduce pain and skin irritation.

According to one aspect, the present invention is a pressure-sensitive adhesive tape having a medical hot-melt pressure-sensitive adhesive layer comprising a lattice pattern formed by two linear stripes intersecting each other,
A plurality of parallelogram openings are formed between the stripes, and the ratio of the longest diagonal length (A) to the shortest diagonal length (B) of the openings is 15 to 1, more preferably 10 to 10. 1, the shortest diagonal length (B) is 0.3 to 7 mm, more preferably 1 to 4 mm, and the minimum length (C) of the stripe intersection along the shortest diagonal length (B) An adhesive tape having a ratio of 1 to 3 with respect to the diagonal length (B) is provided.

  Since the pressure-sensitive adhesive tape of the present invention is provided with the pressure-sensitive adhesive layer having the above-mentioned predetermined pattern, it facilitates smooth peeling at the time of peeling, further greatly reduces pain at the time of peeling, and is further used at the time of sticking. It is intended to optimize the followability, breathability and adhesive strength of the person's skin.

  The present invention is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer having a pattern as described above, and this pressure-sensitive adhesive layer is a pressure-sensitive adhesive tape provided on a support substrate or a self-supporting pressure-sensitive adhesive having no support substrate. It may be a tape.

  The pressure-sensitive adhesive used in the present invention can be a pressure-sensitive adhesive known in the field of medical pressure-sensitive adhesives, and is generally an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive for medical hot melt application. It is preferable to use an adhesive. There is no restriction | limiting in particular as a hot-melt rubber-type adhesive, It is a mixture of synthetic rubber like styrene-isoprene-styrene (SIS) rubber generally used, and tackifier like a rosin-type tackifier. Can be used. Examples of the synthetic rubber include Kraton 1107 and Kraton 1112 manufactured by Kraton Polymer, and examples of the tackifier include FORAL 85 manufactured by Hercules Inc., Wilmington DE. Other synthetic rubbers include styrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR), nitrile-butyl rubber (NBR), chloroprene rubber, silicone rubber, acrylic rubber, butyl rubber, urethane rubber, ethylene-propylene rubber, Examples thereof include fluororubber.

  Examples of the hot-melt acrylic pressure-sensitive adhesive include (i) at least one monoethylenically unsaturated (meth) acrylic acid ester (hereinafter referred to as “first”) containing an alkyl group having an average of at least 4 carbons. Monomer) and (ii) at least one monoethylenically unsaturated reinforcing monomer (hereinafter referred to as "second monomer").

  The first monomer is a monoethylenically unsaturated (meth) acrylic ester (ie, alkyl acrylate or alkyl methacrylate) where the alkyl group has an average of at least 4 carbon atoms. The alkyl group of (meth) acrylate preferably has 4 to 14 carbon atoms. This alkyl group may optionally contain heteroatoms and may be linear or branched. When homopolymerized, these monomers yield an essentially tacky polymer having a glass transition temperature that is generally less than about 10 ° C. Preferred such (meth) acrylate monomers have the general formula

(In the above formula, R ¹ is H or CH ₃ , the latter corresponds to the case where the (meth) acrylate monomer is a methacrylate monomer, and R ² is selected from a linear or branched hydrocarbon group. Optionally containing one or more heteroatoms, the number of carbon atoms in the R ² group is preferably 4 to 14, more preferably 4 to 8.

  Examples of the first monomer include 2-methylbutyl acrylate, isooctyl acrylate, isooctyl methacrylate, lauryl acrylate, 4-methyl-2-pentyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, n- Hexyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, 2-methoxy-ethyl acrylate, 2-ethoxy-ethyl acrylate, n-decyl acrylate, isodecyl acrylate, isodecyl methacrylate, And isononyl acrylate, but not limited thereto. Preferred (meth) acrylates that can be used as the first monomer include isooctyl acrylate, 2-ethylhexyl acrylate, 2-methylbutyl acrylate, and n-butyl acrylate. A combination of various monomers classified as the first monomer can be used to make the hot melt pressure sensitive adhesive component of the pressure sensitive adhesive layer of the present invention.

  The hot-melt acrylic pressure-sensitive adhesive of the pressure-sensitive adhesive layer of the present invention preferably contains at least 85 wt% of the first monomer, more preferably at least 90 wt%, based on the total mass of the hot-melt acrylic pressure-sensitive adhesive. Most preferably comprises at least 95 wt% of the first monomer. Preferably, the hot-melt acrylic pressure-sensitive adhesive of the pressure-sensitive adhesive layer of the present invention contains 99 wt% or less of the first monomer, more preferably 98 wt% or less, based on the total mass of the hot-melt acrylic pressure-sensitive adhesive. Most preferably, it comprises 96 wt% or less of the first monomer.

  A second monomer that is a monoethylenically unsaturated reinforcing monomer increases the glass transition temperature of the copolymer. As used herein, “strengthening” monomers are those that increase the modulus of the adhesive, thereby increasing strength. Preferably, the second monomer has a homopolymer glass transition temperature (Tg) of at least about 10 ° C. The glass transition temperature (Tg) is measured according to JIS-K7121. More preferably, the second monomer is a reinforcing monoethylenically unsaturated free radical copolymerizable (meth) acrylic monomer comprising acrylic acid, methacrylic acid, acrylamide, and acrylate. Examples of the second monomer include acrylamide, methacrylamide, N-methylacrylamide, N-ethylacrylamide, N-methylolacrylamide, N-hydroxyethylacrylamide, acetone acrylamide, N, N-dimethylacrylamide, N, N-diethyl. Acrylamide, N-ethyl-N-aminoethylacrylamide, N-ethyl-N-hydroxyethylacrylamide, N, N-dimethylolacrylamide, N, N-dihydroxyethylacrylamide, t-butylacrylamide, dimethylaminoethylacrylamide, N- Examples include, but are not limited to, octylacrylamide and acrylamides such as 1,1,3,3-tetramethylbutylacrylamide. Other examples of the second monomer include acrylic acid and methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, 2,2- (diethoxy) ethyl acrylate, hydroxyethyl acrylate or methacrylate, 2-hydroxypropyl acrylate Or methacrylate, methyl methacrylate, isobutyl acrylate, n-butyl methacrylate, isobornyl acrylate, 2- (phenoxy) ethyl acrylate or methacrylate, biphenylyl acrylate, t-butylphenyl acrylate, cyclohexyl acrylate, dimethyladamantyl acrylate, 2-naphthyl acrylate , Phenyl acrylate, N-vinylpyrrolidone, and N-vinylcaprolactam. Preferred reinforcing monofunctional acrylic monomers that can be used as the second monomer include acrylic acid and methacrylic acid. A combination of various reinforcing monofunctional monomers classified as the second monomer can be used to make a copolymer of hot melt acrylic adhesive used in the present invention.

  Preferably, the hot melt acrylic pressure sensitive adhesive of the pressure sensitive adhesive layer contains at least 1 wt% of the second monomer, more preferably at least 2 wt%, most preferably based on the total mass of the hot melt acrylic pressure sensitive adhesive. Contains at least 6 wt% of the second monomer. Preferably, the hot-melt acrylic pressure-sensitive adhesive of the pressure-sensitive adhesive layer of the present invention contains 15 wt% or less of the second monomer, more preferably 10 wt% or less, based on the total mass of the hot-melt acrylic pressure-sensitive adhesive. Most preferably, it contains no more than 5 wt% of the second monomer.

  The hot-melt acrylic pressure-sensitive adhesive of the pressure-sensitive adhesive layer of the present invention includes, in addition to the above-mentioned first monomer and second monomer, other monomers copolymerizable with these, such as vinyl esters and N-vinyl lactams. May be present. Examples thereof include polystyrene macromers, poly (methyl methacrylate) macromers, poly (methoxy-ethylene glycol) macromers, 4- (N, N-dimethylamido) butyl acrylate, N-vinyl pyrrolidone; N-vinyl caprolactam and other N- Vinyl lactams; and N-vinylformamide, but are not limited thereto. Various combinations of these monomers can be used as needed. Preferably, the monomer optionally present in this case can be included in an amount of 2 wt% to 20 wt% of the hot melt acrylic adhesive.

  The pressure-sensitive adhesive layer used in the present invention may optionally contain a film-forming component. The film-forming component is particularly preferably included when producing an adhesive tape consisting only of an adhesive layer that does not use a supporting substrate. The film-forming component is composed of a thermoplastic resin that is solid at room temperature and does not exhibit tackiness, and more preferably a thermoplastic resin having a softening point in the range of 25 to 300 ° C. The softening point is measured according to JIS-K7206. Specifically, this thermoplastic resin is selected from the group consisting of polyvinyl, polyester, polyurethane, cellulose resin, polyamide and acetal resin. Examples of the polyvinyl include polyolefins and acrylic resins. Examples of the polyolefin include polyethylene (low density polyethylene, high density polyethylene, linear low density polyethylene), polypropylene, polystyrene, polyvinyl alcohol, polyvinyl acetate, and ethylene-vinyl acetate copolymer. Examples of the acrylic resin include acrylonitrile-butadiene-styrene resin, acrylonitrile styrene resin, and polymethyl methacrylate. Examples of the polyester include polyethylene terephthalate and polycarbonate. A cellulose acetate is illustrated as a cellulose resin. This film-forming component is preferably dispersed uniformly in the hot melt adhesive component.

  In order to improve the shear strength, cohesive strength, elastic modulus, and initial tack or initial adhesive strength of the pressure-sensitive adhesive layer, the copolymer constituting the pressure-sensitive adhesive layer and those in the film-forming component may be crosslinked. It is preferable that a crosslinking agent is a thing copolymerized with a 1st monomer, a 2nd monomer, and another monomer. Crosslinkers can cause chemical crosslinking (eg, covalent bonding). Alternatively, the cross-linking agent can cause physical cross-linking due to, for example, formation of reinforcing domains by phase separation or acid-base interactions. Suitable crosslinking agents are disclosed in U.S. Pat. Nos. 4,379,201, 4,737,559, 5,506,279, and 4,554,324. Has been. Various combinations of crosslinkers can be used to make the copolymer components used in the present invention. Such crosslinkers include chemical crosslinkers, physical crosslinkers and metal crosslinkers.

  Examples of the chemical crosslinking agent include thermal crosslinking agents such as polyvalent aziridine. One example is 1,1 ′-(1,3-phenylenedicarbonyl) -bis- (2-methylaziridine), often referred to as “bisamide”. Such a chemical cross-linking agent can be activated by heat during oven drying of the applied adhesive in addition to the solvent-based adhesive containing acid functional groups after polymerization.

  This chemical crosslinker is a copolymerizable monoethylenically unsaturated aromatic ketone monomer that does not contain an ortho-aromatic hydroxyl group, such as those disclosed in US Pat. No. 4,737,559. is there. Specific examples include para-acryloxybenzophenone, para-acryloxyethoxybenzophenone, para-N- (methylacryloxyethyl) -carbamoylethoxybenzophenone, para-acryloxyacetophenone, ortho-acrylamide acetophenone, acrylated anthraquinones, and the like. is there. Other suitable crosslinking agents include chemical crosslinking agents that rely on free radicals to carry out the crosslinking reaction. For example, reagents such as peroxides serve as precursors for free radicals. When fully heated, these precursors generate free radicals that result in a cross-linking reaction of the polymer chain.

  Apart from thermal crosslinking agents or photosensitive crosslinking agents, crosslinking can be performed using, for example, radiation such as ultraviolet light, X-rays, γ-rays or electron beams, or high energy electromagnetic radiation.

  Examples of the physical crosslinking agent include macromers having a high Tg, such as those containing a vinyl functional group and having polystyrene and polymethyl methacrylate as main components. Such vinyl-terminated polymer crosslinking monomers are sometimes referred to as polymeric monomers (ie macromers). Such monomers are well known and are described in US Pat. Nos. 3,786,116 and 3,842,059, and Y. Yamashita et al., Polymer Journal, 14, 255-260 (1982) and K. It can be prepared by the method disclosed in Ito et al., Macromolecules, 13, 216-221 (1980). In general, such monomers are prepared by anionic polymerization or free radical polymerization.

  Examples of the metal crosslinking agent include metal-containing salts or other metal-containing compounds. Suitable metals include, for example, zinc and titanium. Examples of metal containing compounds include zinc oxide, zinc ammonium carbonate, zinc stearate and the like.

  When using these crosslinkers, an effective amount means sufficient to crosslink the adhesive to provide sufficient cohesive strength and provide the desired final adhesion properties to the adherend. And using a cross-linking agent. When used, it is preferred to use the crosslinking agent in an amount of 0.1 to 10 parts based on 100 parts of monomer.

  In order to change the properties of the pressure-sensitive adhesive, other additives may be included in the pressure-sensitive adhesive forming component and the film-forming component, or may be added at the time of blending or applying the mixture of these two components. Such additives include plasticizers, tackifiers, pigments, reinforcing agents, reinforcing agents, flame retardants, antioxidants, and stabilizers. The additive is added in an amount sufficient to obtain the desired end use properties. Also, fillers such as finely pulverized polymer particles such as glass or polymer bubbles or beads (which may be foamed or unfoamed), fibers, hydrophobic or hydrophilic silica, polyester, nylon and polypropylene May be added.

  Further, it is preferable to add a free radical initiator in order to promote copolymerization of (meth) acrylate and acidic comonomer. The type of initiator used depends on the polymerization method. Useful photoinitiators for polymerizing a polymerizable mixture of monomers include benzoin ethers such as benzoin methyl ether or benzoin isopropyl ether, substituted benzoin ethers such as 2-methyl-2-hydroxypripiophenone, 2 -Aromatic sulfonyl chlorides such as naphthalene sulfonyl chloride, and photoactive oxides such as 1-phenyl-1,1-propanedione-2- (O-ethoxycarbonyl) oxime. An example of a commercially available photoinitiator is IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethane-1-one, commercially available from Ciba-Geigy Corporation). Examples of suitable thermal initiators include AIBN (2,2'-azobis (isobutyronitrile)), hydroperoxides such as tert-butyl hydroperoxide, and peroxides such as benzoyl peroxide and cyclohexane peroxide. It is done. Generally, the initiator is present in an amount of 0.005 wt% to 1 wt%, based on the weight of copolymerizable monomer.

  A chain transfer agent is also optionally included to control the molecular weight of the copolymer. Chain transfer agents are substances that control free radical polymerization and are generally well known in the art. Suitable chain transfer agents include alcohols (eg, methanol, ethanol and isopropanol), halogenated hydrocarbons such as carbon tetrabromide; lauryl mercaptan, butyl mercaptan, ethanethiol, isooctyl thioglycolate (IOTG), 2 -Sulfur compounds such as ethylhexyl thioglycolate, 2-ethylhexyl mercaptoprepionate, 2-mercaptoimidazole, and 2-mercaptoethyl ether, and mixtures thereof. The amount of useful chain transfer agent depends on the molecular weight and type of chain transfer agent desired. Non-alcohol chain transfer agents are generally used in amounts of 0.001 to 10 parts by weight per 100 parts of total monomer, preferably 0.01 to 0.5 parts, most preferably 0.02 to 0. It is used in an amount of 20 parts and may be more in the case of alcohol-containing systems.

  The copolymer can be polymerized by a wide variety of conventional free radical polymerization methods. Suitable methods include those described in U.S. Pat. Nos. 4,181,752, 4,833,179, 5,804,610 and 5,382,451.

  For example, in solution polymerization processes, alkyl (meth) acrylate monomers and acidic monomers, together with a suitable inert organic solvent, and, if used, a free radical copolymerizable crosslinker, a stirrer, thermometer, condenser, Place in a four-necked reaction vessel equipped with an addition funnel and a Thermowatch ™ temperature monitor. After the monomer mixture is placed in the reaction vessel, the concentrated thermal free radical initiator solution is added to the addition funnel. The entire reaction vessel and addition funnel and their contents are then purged with nitrogen to create an inert atmosphere. Once purged, the solution in the vessel is heated to decompose the added thermal initiator and the mixture is stirred throughout the reaction. Generally, about 98 to about 99% conversion is obtained in about 20 hours. If necessary, the solvent is removed to produce a pressure-sensitive adhesive capable of hot melt coating. If necessary, a suitable inert organic solvent may be an organic liquid inert to the reactants and products, otherwise it will not adversely affect the reaction. Such solvents include ethyl acetate, acetone, methyl ethyl ketone, and mixtures thereof. The amount of solvent is generally from about 30 wt% to about 80 wt%, based on the total mass of reactants (monomer, crosslinker, initiator) and solvent.

Another polymerization method is ultraviolet (UV) initiated photopolymerization of the monomer mixture. This composition, along with a suitable photoinitiator and crosslinking agent, is applied onto a flexible carrier web and polymerized in an inert atmosphere, ie, an oxygen-free atmosphere such as a nitrogen atmosphere. A sufficiently inert atmosphere can be realized. The photoactive coating layer is covered with a plastic film that is substantially transparent to UV light, and is generally passed through the film in air using a fluorescent lamp type UV lamp that gives a total dose of about 500 millijoules / cm ^2. Irradiate.

  Continuous free radical polymerization in an extruder as described in US Pat. Nos. 4,619,979 and 4,843,134; described in US Pat. No. 5,637,646 An essentially adiabatic polymerization process using a batch reactor; and a process described for polymerizing a packaged pre-adhesive composition as described in US Pat. No. 5,804,610 It is also possible to produce the copolymer using a solventless polymerization process such as

  When the film-forming component described above is included, particularly when an adhesive tape without a supporting substrate is produced, the ratio to the hot melt adhesive is 40 to 95 wt% hot melt adhesive and 5 to 60 wt%. It is a film forming component. This is because when the film forming component is insufficient, the pressure-sensitive adhesive layer has insufficient strength, and when it is too much, the adhesive strength is insufficient.

  Further, the thickness of the pressure-sensitive adhesive layer used in the present invention may be any thickness as long as the pressure-sensitive adhesive layer can be applied by forming it in two linear stripes intersecting each other, but is generally in the range of 5 to 1000 μm, preferably May be in the range of 10 to 350 μm.

  The support substrate used in the present invention may be any known substrate used for medical adhesive tapes. For example, organics such as polyethylene, polypropylene, polybutene, polyolefins such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, or other plastics such as polyurethane, polyester, polyamide, etc. Examples thereof include a perforated film made of a polymer, a foam sheet having open cells, a foam, and a laminate thereof. In many cases, the base material itself is required to have air permeability and moisture permeability for use in medical applications, such as those described in US Pat. No. 5,496,603, such as woven fabrics, nonwoven fabrics, meltblown webs, foams, and spans. Examples include bond webs, thermal bond webs, spunlace webs, paper, and hot embossed nonwovens. More specific examples include woven fabrics, knitted fabrics, non-woven fabrics, paper, and polyvinyl alcohol perforated films made of organic polymers such as cotton, polyvinyl alcohol, and cellulose. These base materials may be used after being subjected to water repellent treatment with a known water repellent as required. Furthermore, the substrate may be stretchable or non-stretchable. A substrate having excellent breathability or moisture permeability and good stretchability can be preferably applied. In particular, stretchable cotton cloth (woven cloth) or non-woven cloth is preferably used. Furthermore, a waterproof base material (for example, a film made of urethane) can be used. The supporting substrate is not particularly limited, but generally has a thickness of 15 to 2000 μm.

  The pressure-sensitive adhesive tape of the present invention is produced as follows. In the case of a pressure-sensitive adhesive tape consisting only of a pressure-sensitive adhesive layer, it can be produced by die-coating a hot melt pressure-sensitive adhesive on a release film such as a polyethylene terephthalate (PET) film whose surface has been subjected to a release treatment. The release film can act as a protective film until it is removed during use. On the other hand, in order to obtain a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a supporting substrate, the pressure-sensitive adhesive tape can be obtained by transferring the pressure-sensitive adhesive layer on the release film produced as described above onto the supporting substrate. .

  When the pressure-sensitive adhesive tape of the present invention is not provided on a support substrate, it is preferable to provide a non-sticky coating layer on one side of the pressure-sensitive adhesive layer. The non-adhesive coating layer provided on the pressure-sensitive adhesive layer loses the adhesiveness on one side of the pressure-sensitive adhesive layer without impairing the flexibility of the pressure-sensitive adhesive layer. The thickness of this non-adhesive coating layer is usually 0.01 to 30 μm, preferably 0.01 to 15 μm, more preferably 0.01 to 10 μm, and still more preferably 0.01 to 5 μm. When this thickness exceeds 30 μm, the flexibility of the adhesive tape is impaired. On the other hand, when the thickness is less than 0.01 μm, the adhesiveness on one side of the adhesive layer cannot be killed and a single-sided adhesive tape cannot be obtained. This non-adhesive coating layer is composed of generally used release treatment agents such as acrylic release agents, silicone release agents (eg TPR 6501 made by GE-Toshiba Silicon), polyurethane release agents, printing inks (eg Dainichi Seiki). Non-adhesive powder such as organic powder (eg starch, wheat flour or starch), inorganic powder, metal powder, pigment (eg titanium oxide, carbon).

  As described above, in one aspect, the pressure-sensitive adhesive tape of the present invention is a pressure-sensitive adhesive tape having a lattice pattern having the specific shape described above, and the pressure-sensitive adhesive layer is composed of only the pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer is a supporting substrate. It may be provided on one side. FIG. 3 shows a top view of the medical adhesive tape of the present invention. The hatched portion indicates a region having an adhesive pattern, and the portion without a hatched portion indicates a region having no adhesive pattern. It has a lattice pattern provided with openings of parallelograms (diamonds are shown), and the ratio of the longest diagonal length (A) to the shortest diagonal length (B) of this opening is 15-1 Yes, preferably 10 to 1, shortest diagonal length (B) is 0.3 to 7 mm, more preferably 1 to 4 mm, and stripe intersection along the shortest diagonal length (B) The ratio of the length (C) to the shortest diagonal length (B) is 1-3.

  When the pattern has such a dimension, it can follow the skin that stretches in any direction of 360 °. Moreover, since it is similar to the surface pattern of the skin, it is possible to impart skin followability and suppress pain at the time of peeling, and further reduce mechanical stimulation during application or at the time of peeling.

  Here, when the ratio of the longest diagonal length (A) of the opening to the shortest diagonal length (B) exceeds 15, the longest diagonal length (A) is too long compared to the shortest diagonal length (B). Since the shape of the opening is too far away from the surface pattern of the skin, particularly when the pressure-sensitive adhesive tape is peeled off from the skin, a smooth peeling feeling when the pressure-sensitive adhesive tape is peeled from the side cannot be obtained. On the other hand, if the ratio of the longest diagonal length (A) to the shortest diagonal length (B) is less than 1, it is not preferable because it is difficult to apply the adhesive.

  Moreover, the shortest diagonal length (B) is preferable since the width of the tape when the tape of the present invention is slit into a roll-like tape is assumed to be a narrow width such as 12.5 mm, 25 mm, 75 mm, etc. Is preferably about 0.3 to 7 mm. Depending on the width of the adhesive tape, more preferably about 1 to 4 mm is preferably applied. If the shortest diagonal length (B) exceeds 7 mm, when the tape is slit to a slit width of 12.5 mm, there are too many openings without an adhesive, and a predetermined amount of adhesive force to the skin cannot be obtained, which is not preferable. On the other hand, if the shortest diagonal length (B) is less than 0.3 mm, it is not preferable because coating becomes difficult by hot-melt die coating.

  When the ratio of the length (C) of the stripe intersection along the shortest diagonal length (B) to the shortest diagonal length (B) exceeds 3, the apparent pattern of the pressure-sensitive adhesive layer is too far from the surface pattern of the skin. It is not preferable because it is far away and the ratio of the opening occupying the surface of the pressure-sensitive adhesive layer is small, and the adhesive force of the pressure-sensitive adhesive tape is increased. Conversely, if this ratio is less than 1, it is not preferable because the spaces existing between the adhesive layers cannot be arranged in a desired lattice shape.

  As described above, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the present invention can be formed by die coating. According to die coating, when the pressure-sensitive adhesive coating solution is applied so as to form a pressure-sensitive adhesive layer, the pressure-sensitive adhesive can be stretched, and the polymer molecules constituting the pressure-sensitive adhesive layer can be oriented. . By such orientation of the polymer molecules, the pressure-sensitive adhesive layer can have an appropriate stiffness, and as a result, it can be processed as a pressure-sensitive adhesive tape without a supporting substrate (self-supporting pressure-sensitive adhesive tape).

  Furthermore, the orientation of the polymer molecules constituting the pressure-sensitive adhesive layer also has an advantage in the case of a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on a support substrate. In general, the supporting substrate is often stretched or oriented in the longitudinal direction. In such a support substrate, the elongation behavior in the longitudinal direction is different from the elongation behavior in the transverse direction perpendicular thereto. On the other hand, a pressure-sensitive adhesive layer having no orientation of polymer molecules has the same extensibility in any direction. When a pressure-sensitive adhesive layer having no polymer molecular orientation is provided on such a supporting substrate, the elongation behavior differs between the substrate and the pressure-sensitive adhesive layer. Therefore, distortion occurs between the base material and the pressure-sensitive adhesive layer, a force is generated in a direction different from the extension direction, and an uncomfortable feeling is caused when the pressure-sensitive adhesive tape being stuck is stretched. However, in the pressure-sensitive adhesive tape of the present invention, since the pressure-sensitive adhesive layer is formed by die coating, the polymer molecules can be oriented in the same direction as the base material when the pressure-sensitive adhesive layer is formed on the substrate. As a result, it is possible to reduce a sense of incongruity due to expansion and contraction of the adhesive tape being stuck.

Hereinafter, the present invention will be specifically described according to examples.
Example 1
750 g of deionized water was placed in a 2 liter flask and 1.5 g of ZnO and 0.75 g of hydrophilic silica were added thereto. The flask was purged with nitrogen and heated to 55 ° C. until the ZnO and silica were dispersed. Separately, a mixture of 480 g of isooctyl acrylate, 20 g of methyl methacrylate and 1 g of acryloxybenzophenone is stirred with 2.5 g of VAZO ^™ 64 (EIDuPont initiator) and 0.5 g of isooctyl thioglycolate. Added while. The solution containing the initiator and chain extender thus obtained was added to the above aqueous solution with vigorous stirring (700 rpm) to obtain a suspension. The reaction was continued for at least 6 hours with a nitrogen purge while the reaction temperature was not allowed to exceed 70 ° C. The beads thus formed were collected by filtration and washed with deionized water. This was dried to obtain an acrylic pressure-sensitive adhesive as a hot-melt pressure-sensitive adhesive. This pressure-sensitive adhesive was extruded at 165 ° C. with an extruder to prepare a pressure-sensitive adhesive raw material.

  Next, at 140 ° C., the pressure-sensitive adhesive raw material has a thickness of 50 μm on the smooth surface of the release paper, and the ratio of the longest diagonal length (A) to the shortest diagonal length (B) is 4, the shortest diagonal line After coating so that the length (B) is 2 mm, and the ratio of the length (C) of the stripe intersection along the shortest diagonal length (B) to the shortest diagonal length (B) is 1, Two stripe-shaped pressure-sensitive adhesive layers intersecting each other were formed by irradiation with ultraviolet rays.

On the obtained pressure-sensitive adhesive layer, a support base material made of stretchable cotton cloth as described below was laminated, and the pressure-sensitive adhesive layer was transferred onto the support base material to obtain the pressure-sensitive adhesive tape of the present invention. This support base material is rich in stretchability in the longitudinal direction, and is a stretchable cotton cloth having a stress of 10% elongation of 0.57 N / 50 mm, and has the following constitution.
Organization Plain weave: warp; C / S / Y count 20/1, manufactured by Nitto Boseki Co., Ltd. Sheath material-extra long cotton (fiber made of 40 denier urethane core (96% cotton, 4% polyurethane)), weft; cotton count 16/1 (fiber made of 100% cotton)
Density (warp): 32 / inch Density (weft): 48 / inch

Example 2
A pressure-sensitive adhesive tape different from Example 1 was obtained only in that the pressure-sensitive adhesive was applied with a ratio of the longest diagonal length (A) to the shortest diagonal length (B) of 6.

Example 3
The ratio of the longest diagonal length (A) to the shortest diagonal length (B) was 7, the shortest diagonal length (B) was 4 mm, and an adhesive tape different from that of Example 1 was obtained only in that an adhesive was applied. .

Example 4
The ratio of the longest diagonal length (A) to the shortest diagonal length (B) was 15, and an adhesive tape different from Example 1 was obtained only in that the adhesive was applied.

Example 5
The ratio of the length (C) of the stripe intersection along the shortest diagonal length (B) to the shortest diagonal length (B) is 3, and an adhesive tape different from that of Example 1 is obtained only in that the adhesive is applied. It was.

Example 6
The hot melt pressure-sensitive adhesive used in Example 1 was uniformly kneaded with low density polyethylene (Novatec LD manufactured by Nippon Polyethylene) at a mass ratio of 90:10 using a twin screw extruder at 165 ° C. to obtain a pressure-sensitive adhesive mixture. . The mixture was formed such that the thickness of the release paper (trade name SLK-50W, manufactured by Kite Chemical Co., Ltd.) had a thickness of 175 μm, and the ratio of the longest diagonal length (A) to the shortest diagonal length (B) was 4, Coating was performed so that the shortest diagonal length (B) was 2 mm and the ratio of the stripe intersection length (C) along the shortest diagonal length (B) to the shortest diagonal length (B) was 1. Thereafter, two stripe-shaped pressure-sensitive adhesive layers that cross each other were formed by irradiation with UV.

  On the smooth surface of another release paper (trade name SLK-50W, manufactured by Kite Chemical), a silicone release treatment agent (trade name: UV9300 GE manufactured by Toshiba Silicone) was coated on the entire surface (after drying) to a thickness of 7 μm, and then The silicone release agent was dried in an oven at 70 ° C. and then irradiated with UV to form a non-stick coating layer. This non-adhesive coating layer was brought into close contact with the pressure-sensitive adhesive layer and transferred to obtain the pressure-sensitive adhesive tape of the present invention.

Example 7
The ratio of the longest diagonal length (A) to the shortest diagonal length (B) is 9, and the ratio of the stripe intersection length (C) along the shortest diagonal length (B) to the shortest diagonal length (B) 1.5, an adhesive tape different from Example 6 was obtained only in that an adhesive was applied.

Example 8
The ratio of the longest diagonal length (A) to the shortest diagonal length (B) was 7, the shortest diagonal length (B) was 4 mm, and an adhesive tape different from Example 6 was obtained only in that an adhesive was applied. .

Comparative Example 1
A pressure-sensitive adhesive tape different from that of Example 1 was obtained only in that the entire surface was coated without providing a pattern on the pressure-sensitive adhesive layer.

Comparative Example 2
Nitto Denko's adhesive bandage and kinopress (adhesive layer is a wavy vertical stripe coating product) were used.

Comparative Example 3
The ratio of the longest diagonal length (A) to the shortest diagonal length (B) was 20, and an adhesive tape different from Example 1 was obtained only in that the adhesive was applied.

Comparative Example 4
The ratio of the length (C) of the stripe intersection along the shortest diagonal length (B) to the shortest diagonal length (B) is 10, and an adhesive tape different from that in Example 1 is obtained only in that the adhesive is applied. It was.

Comparative Example 5
The shortest diagonal length (B) was 8 mm, and an adhesive tape different from Example 1 was obtained only in that an adhesive was applied.

1. Adhesive Tape Evaluation Test The following evaluations were performed on the prototype samples created in the above examples and comparative examples.
≪Smoothness when peeling≫
When a tape of 50mm x 100mm is applied to the back of 6 healthy people and peeled at a speed of 300mm / min at 180 ° peel in the vertical or horizontal direction 24 hours after application, Since the gaps appear alternately and cannot be peeled off smoothly, an interview was conducted regarding the sensation of the pain (mechanical stimulation) that occurred and scored as follows.
++: Can peel smoothly +: Smooth but feels a slight mechanical stimulus-: Not smooth but feels a mechanical stimulus

≪Pain when peeling≫
A tape of 50mm x 100mm was put on the back of 6 healthy people, and after 24 hours, an interview was conducted about the sensation of pain when the adhesive tape was peeled longitudinally at a speed of 300mm / min at 180 ° peel. And scored as follows.
++: No pain at all +: Not painful, tolerable-: Painful

≪Skin adhesive power≫
The tape of the present invention of 25 mm × 75 mm was affixed to the backs of 6 healthy persons, and the adhesive strength when peeled at a speed of 300 mm / min at 180 ° peel was measured 0 hours after the affixing.

≪Skin comfort level with adhesive tape attached≫
A tape of 50 mm x 100 mm was affixed to the backs of six healthy persons, and the coolness during the affixing was interviewed and scored as follows.
++: The adhesive tape application site is cool and comfortable.
+: Intermediate between ++ and--: Adhesive tape application site feels hot and uncomfortable

≪Float≫
A tape of 50 mm × 100 mm was affixed to the backs of 6 healthy people, and 24 hours after the affixing, the tape was scored as follows for the absence of lift.
++: No lifting +: Slight lifting occurred at the edge of the tape −: Large lifting occurred at the edge of the tape

The evaluation results of Examples 1 to 8 and Comparative Examples 1 to 5 are summarized in Table 1.

  From the results of Examples 1 to 8 and Comparative Examples 1 to 5, the ratio (parameter 1) of the longest diagonal length (A) to the shortest diagonal length (B) is in the range of 1 to 15, more preferably 1 to 15. It was found that by setting the range to 10, even if peeled from either the vertical direction or the horizontal direction, it was possible to peel with a mild peel feeling without causing jerky peel, and it was difficult to induce skin fogging. Furthermore, it was found that lifting during application could be suppressed.

  As for the shortest diagonal length (B) with respect to (parameter 2), in the case of Comparative Example 5, when (B) increases, the size or shape of the space between the adhesive layers increases, so the adhesive tape is slit into a narrow width. Therefore, since many portions without adhesive are exposed at the slit ends, there is a possibility that floating may occur from the ends when it is applied, which is not preferable. Therefore, if the value of (B) is large, it is not preferable to use the tape in small pieces, which is not preferable. Therefore, the range of 0.3 to 7 mm, more preferably 1 to 4 mm (adhesive tape with a width of 12.5 mm, etc.) In the case of the case to be used, it has been found that it is preferable to set it to 4 mm or less because there is a possibility that the edge portion may float.

  Also, as the ratio of the length (C) of the stripe intersection along the shortest diagonal length (B) to the shortest diagonal length (B) increases, the skin adhesive force increases and the space between the adhesive layers decreases. It is preferable that it is the range of 1-3.

  Further, as shown in Examples 6 to 8, it is also possible to obtain the pressure-sensitive adhesive tape of the present invention which does not substantially require a supporting base material, and is not affected by the supporting base material. A rich adhesive tape of the present invention could be obtained. Also, these tapes are very useful because the tape itself stretches moderately and relieves stress when the tape is peeled off, so that the skin adhesive force can be greatly suppressed.

2. Verification for skin followability In order to more clearly describe the effects of the present invention, particularly the skin followability, the following evaluation was performed.
The adhesive tape of the present invention is characterized by following the expansion and contraction of the skin without friction when it is applied to the skin.
Therefore, in order to evaluate this excellent followability, the stretchable cotton cloth (hereinafter referred to as cotton cloth) is rich in stretchability in the longitudinal direction and has a stress at 10% elongation of 0.57 N / 50 mm (the measurement method is described below). (Call)
Organization Nitto Boseki Co., Ltd. C / S / Y count 20/1, sheath material extra long cotton, (fiber made of 40 denier urethane core (96% cotton, 4% polyurethane)), weft; cotton count 16/1 ( 100% cotton fiber)
Density (warp): 32 strands / inch Density (weft): 48 strands / inch was prepared, and the evaluation was performed by regarding this as pseudo skin. That is, by laminating the pressure-sensitive adhesive layer of the present invention on this cotton cloth that looks like this artificial skin, the state where the pressure-sensitive adhesive layer is stuck to the skin is reproduced, and when the cotton cloth laminated with the pressure-sensitive adhesive layer is stretched by 10% When the stress is measured, the closer to 0.57 N / 50 mm, the more the adhesive layer does not hinder the expansion and contraction of the adherend, indicating that the followability to the skin is good. In general, when the pressure-sensitive adhesive layer is laminated, the expansion and contraction of the adherend is inhibited by the pressure-sensitive adhesive layer, and it can be said that the stress at the time of 10% elongation becomes a high value.

Regarding stress relaxation in the transverse direction First, the pressure-sensitive adhesive prepared in (1) of Example 1 was coated on the entire surface of the liner so as to have a thickness of 100 μm (solid coating). ° Laminate to cross, make a sample with pressure-sensitive adhesive layer and cotton cloth crimped by reciprocating a 2kg roller from the top of the liner at a speed of 300mm / min, peeling the liner, and using a tensile tester The stress when the sample was extended by 10% at a temperature of 23 ° C. and an extension rate of 300 mm / min (sample width 50 mm, gripping interval 100 mm) was measured. As a result, the stress at 10% elongation was 1.25 N / 50 mm. Considering that the stress at 10% elongation of the cotton fabric before lamination (assuming a blank value) was 0.57 N / 50 mm, the elastic layer stretched just by the adhesive layer on the cotton fabric. Is significantly inhibited. Therefore, Samples 1 to 3 of the present invention as described below were prepared, the stress at the time of 10% elongation was measured in the same manner, and evaluation points were given as follows.
++: High followability 10% elongation stress is 0.57N / 50mm to 0.75N / 25mm (equivalent to 60% of 1.25)
+: Follow up The stress at 10% elongation is 0.75 N / 50 mm to 1.00 N / 25 mm
-: Not following, stress at 10% elongation is 1.00 N / 25 mm (equivalent to 80% of 1.25) to 1.25 N / 50 mm
Samples 1-3: The pressure-sensitive adhesive prepared in (1) of Example 1 was coated on a liner so that the parameter had a thickness of 100 μm as shown in Table 2, and the longitudinal direction of the cotton cloth was 90 μm. The samples were bonded so as to cross each other, and a 2 kg roller was reciprocated once from the top of the liner at a speed of 300 mm / min to bond the pressure-sensitive adhesive layer and the cotton cloth, thereby peeling the liner.

About longitudinal stress relaxation First, the adhesive prepared in (1) of Example 1 was coated on the entire surface of the liner so as to have a thickness of 100 μm (solid coating), and the longitudinal direction was consistent with the above cotton cloth. The sample was made by reciprocating a 2 kg roller from the top of the liner at a speed of 300 mm / min to make a pressure-sensitive adhesive layer and cotton cloth, and the liner was peeled off. The stress (with a sample width of 50 mm and a gripping interval of 100 mm) was measured when the sample was stretched by 10% at 23 ° C. and an elongation rate of 300 mm / min. As a result, the stress at 10% elongation was 4.31 N / 50 mm. Considering that the stress at 10% elongation of the cotton fabric before lamination (assuming a blank value) was 0.57 N / 50 mm, the elastic layer stretched just by the adhesive layer on the cotton fabric. Is significantly inhibited. Therefore, the following samples 4 to 6 of the present invention were prepared, and the stress at the time of 10% elongation was similarly measured, and the evaluation points were given as follows.
++: High followability 10% elongation stress is 0.57N / 50mm to 3.45N / 25mm (equivalent to 80% of 4.31)
+: Follow up The stress at 10% elongation is from 3.45 N / 50 mm to 3.88 N / 25 mm
-: Not following 10% elongation stress 3.88N / 25mm (equivalent to 90% of 4.31) to 4.31N / 50mm
Samples 4 to 6: The pressure-sensitive adhesive prepared in (1) of Example 1 was coated on a liner so that the parameter had a thickness of 100 μm as shown in Table 3, and was applied to the above cotton cloth. The samples were laminated so that the directions coincided, and a 2 kg roller was reciprocated once from the top of the liner at a speed of 300 mm / min to bond the pressure-sensitive adhesive layer and the cotton cloth, thereby peeling off the liner.

  From this result, the ratio of the longest diagonal length (A) of the opening to the shortest diagonal length (B) is 15 to 1, more preferably 10 to 1, and the shortest diagonal length (B) is 0.3. -7 mm, more preferably 1-4 mm, and the ratio of the stripe intersection length (C) along the shortest diagonal length (B) to the shortest diagonal length (B) is 1 to 3 Thus, it was found that an adhesive tape that does not become a jerky peel even when peeled from any direction, can reduce pain during peeling, suppresses floating during application, and has good followability to the skin can be provided.

The top view of the adhesive tape which has a strip-shaped adhesive pattern of a prior art is shown. The top view of the adhesive tape which has a wavy adhesive pattern of a prior art is shown. The top view of the adhesive tape which has an adhesive pattern of this invention is shown.

Claims (3)

A pressure-sensitive adhesive tape having a medical hot-melt pressure-sensitive adhesive layer composed of a lattice pattern formed by two linear stripes intersecting each other,
A plurality of parallelogram openings are formed between the stripes, and the ratio of the longest diagonal length (A) to the shortest diagonal length (B) of the openings is 15 to 1, and the shortest diagonal length The length (B) is 0.3 to 7 mm, and the ratio of the stripe intersection length (C) along the shortest diagonal length (B) to the shortest diagonal length (B) is 1 to 3. ,Adhesive tape.   The pressure-sensitive adhesive tape according to claim 1, wherein the medical hot-melt pressure-sensitive adhesive layer further comprises 60 to 5 wt% of a film-forming component. The pressure-sensitive adhesive tape according to claim 1 or 2, wherein the medical hot melt pressure-sensitive adhesive layer is provided on a support substrate.

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