JP2018131584A - Skin adhesive tape and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a skin-sticking tape which can suppress exfoliation of keratin, has sufficient holding power, and hardly causes adhesive residue when exfoliated. A substrate having an elongation of 10% or more and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate are provided, and the pressure-sensitive adhesive layer is an alkyl having an alkyl group having 4 to 18 carbon atoms. Meta) All monomers constituting the cross-linking reaction product containing a cross-linking reaction product containing an acrylate monomer, a radiation-crosslinking group-containing ethylenically unsaturated monomer, and an ethylenically unsaturated polar monomer as a monomer unit. The mass ratio of the ethylenically unsaturated monomer containing a radiation cross-linking group to the above is 0.05 to 10% by mass, and the mass ratio of the ethylenically unsaturated polar monomer to all the monomers constituting the cross-linking reaction product is 3.0 mass. Percentage, skin-adhesive tape. [Selection diagram] None

Description

  The present invention relates to a skin adhesive tape and a method for producing the same.

  In medical applications, tapes for skin attachment such as surgical tapes and dressing tapes are widely used. The skin sticking tape has a configuration in which an adhesive layer is provided on a substrate, and an acrylic pressure-sensitive adhesive (acrylic adhesive) or the like is used for the adhesive layer.

  While the acrylic pressure-sensitive adhesive is excellent in adhesive force, when it is used for the adhesive layer, horny detachment occurs when the tape is peeled from the skin, and pain may be caused by physical irritation. Patent Document 1 discloses a pressure-sensitive adhesive composition comprising a polymer, an excess amount of a liquid component compatible with the polymer, and a crosslinking agent. The pressure-sensitive adhesive composition is formed into a film and crosslinked. It is said that exfoliation of the stratum corneum can be suppressed by using a patch having a pressure-sensitive adhesive layer.

JP-A-5-139960

  However, when an excessive amount of a liquid component that is compatible with the polymer constituting the pressure-sensitive adhesive and has a plasticizing action is contained, the holding power tends to decrease, and the adhesive residue tends to occur when the tape is peeled off. This has been clarified by the knowledge of the present inventors.

  In one embodiment, the present invention includes a base material having an elongation of 10% or more and a pressure-sensitive adhesive layer laminated on at least one side of the base material, and the pressure-sensitive adhesive layer has an alkyl group having 4 to 4 carbon atoms. All of which comprises a crosslinking reaction product comprising 18 alkyl (meth) acrylate monomers, a radiation crosslinking group-containing ethylenically unsaturated monomer, and an ethylenically unsaturated polar monomer as monomer units, and constituting a crosslinking reaction product The mass ratio of the radiation-crosslinking group-containing ethylenically unsaturated monomer to the monomer is 0.05 to 10% by mass, and the mass ratio of the ethylenically unsaturated polar monomer to all the monomers constituting the crosslinking reaction product is Provided is a skin sticking tape that is less than 3.0% by weight.

  According to the above-mentioned skin sticking tape, exfoliation of the stratum corneum can be suppressed without containing a liquid component having a plasticizing action, and sufficient holding power can be obtained. Moreover, the said skin sticking tape has sufficient adhesive force and the stable adhesive characteristic, and the raise with time of adhesive force is reduced to the level which does not have a problem practically. Moreover, in the said skin affixing tape, when peeling, an adhesive residue hardly arises and it can exhibit the excellent removability. Moreover, the said skin sticking tape can be used after being sterilized by electron beam irradiation or the like, and can exhibit the above adhesive properties even after sterilization.

  By the way, usually, an acrylic pressure-sensitive adhesive has a certain amount (for example, 5% by mass or more) of an ethylenically unsaturated polar monomer (for example, acrylic acid) as a monomer unit in order to impart cohesive force to the pressure-sensitive adhesive. include. Especially when it is necessary to lower the weight average molecular weight of the base polymer as in hot melt pressure-sensitive adhesives, pressure-sensitive adhesive having sufficient adhesive strength and hardness without containing an ethylenically unsaturated polar monomer It is difficult to obtain an agent. In contrast, in the skin adhesive tape, the cross-linking reaction product in the pressure-sensitive adhesive layer contains a predetermined amount of a radiation cross-linkable monomer as a monomer unit and has a cross-linking structure derived from the radiation cross-linkable monomer. Even when the mass ratio of the ethylenically unsaturated polar monomer to all monomers constituting the product is less than 3.0% by mass, it has sufficient adhesive force and internal cohesion. In addition, when an excessive amount of a liquid component having a plasticizing effect is contained, the liquid component that is not cross-linked becomes excessive, so that the holding force and cohesive force of the adhesive are usually reduced. In the tape, since the mass ratio of the ethylenically unsaturated polar monomer is less than 3.0% by mass, the adhesive strength does not become too strong, and it is not necessary to contain a liquid component having a plasticizing action.

  The crosslinking reaction product includes a skeleton derived from a first polymer containing an alkyl (meth) acrylate monomer having an alkyl group having 4 to 18 carbon atoms as a monomer unit, and an alkyl having 4 to 18 carbon atoms in the alkyl group ( And a skeleton derived from a second polymer containing a monomer unit of a (meth) acrylate monomer and a radiation crosslinking group-containing ethylenically unsaturated monomer. In this case, at least one of the first polymer and the second polymer further contains an ethylenically unsaturated polar monomer as a monomer unit. Since the crosslinking reaction product has a skeleton derived from the second polymer, which is a polymer compound that generates a crosslinked structure by radiation (for example, ultraviolet rays), it is possible to more effectively prevent an increase in adhesive force over time, and it is even higher. Has holding power.

  In the above skin adhesive tape, at least one of the first polymer and the second polymer may contain a basic monomer as an ethylenically unsaturated polar monomer, and a base for all monomers constituting the cross-linking reaction product. The mass ratio of the functional monomer may be 0.0005 mass% or more and less than 3.0 mass%. When the mass ratio of the basic monomer is within the above range, adhesion to the substrate is strengthened, adhesive residue is less likely to occur, adhesive strength is not excessively increased, and exfoliation of the keratin is further suppressed.

  In the skin sticking tape, the crosslinking reaction product may be substantially free of an acidic monomer (for example, (meth) acrylic monomer) as a monomer unit. According to such a skin sticking tape, an increase in adhesive force with time is further suppressed, and exfoliation of the keratin is further suppressed.

  In the skin sticking tape, the crosslinking reaction product may be substantially free of acrylic acid as a monomer unit. According to such a skin sticking tape, an increase in adhesive force with time is further suppressed, and exfoliation of the keratin is further suppressed.

  The skin sticking tape is formed by irradiating a precursor layer made of a pressure-sensitive adhesive composition formed on a base material having an extension degree of 10% or more with a radiation, and a pressure-sensitive adhesive layer containing a crosslinking reaction product as a base material. It can be manufactured by a method for manufacturing a skin sticking tape comprising a process obtained above. The pressure-sensitive adhesive composition used in this method includes a first polymer containing an alkyl (meth) acrylate monomer having an alkyl group having 4 to 18 carbon atoms as a monomer unit, and an alkyl group having 4 to 18 carbon atoms. A second polymer containing an alkyl (meth) acrylate monomer and a radiation crosslinking group-containing ethylenically unsaturated monomer as a monomer unit, and at least one of the first polymer and the second polymer is ethylenic It further contains an unsaturated polar monomer as a monomer unit. The mass ratio of the radiation-crosslinking group-containing ethylenically unsaturated monomer to all monomers constituting the first and second polymers is 0.05 to 10% by mass, and the first and second polymers are The mass ratio of the ethylenically unsaturated polar monomer to all constituting monomers is less than 3.0% by mass. The pressure-sensitive adhesive composition can be applied onto the substrate by hot melt processing.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to suppress exfoliation of a keratin, it has sufficient holding power and can provide the skin sticking tape which does not produce adhesive residue when peeling, and its manufacturing method.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. (Meth) acrylate means acrylate or methacrylate, and the same applies to other similar expressions such as (meth) acrylic acid. In the present specification, “substantially does not contain” means that the content of the target component is less than 0.0005 mass%. In the present specification, “adhesive strength” refers to, for example, peel strength measured by a 180 ° peel test, and “holding force” refers to, for example, shear strength measured by a shear strength test.

  The skin sticking tape which concerns on this embodiment is equipped with the base material whose degree of extension is 10% or more, and the adhesive layer laminated on at least one side of the base material. This skin sticking tape has removability (repositionable) and can be widely used in medical applications and the like. Specifically, it can be used for surgical tape, kinesio tape, sports tape, dressing tape (such as “Tegaderm” manufactured by 3M), bandage and the like. The shape of the skin sticking tape is not particularly limited, and may be, for example, a sheet shape.

From the viewpoint of application to the skin, the base material needs to have an elongation of 10% or more. However, as long as the base material is used, it is a base used for conventional skin adhesive tapes such as Japanese paper, polymer films, nonwoven fabrics, and cotton cloths. A material (for example, a backing material) can be arbitrarily used. The degree of elongation of the substrate can be measured by a tensile measuring instrument such as Tensilon, and may be, for example, 10 to 100%. The thickness of the substrate can be appropriately set according to the type of the substrate. When the substrate is a polymer film, the thickness of the substrate may be 10 to 50 μm. When a base material is a nonwoven fabric, the thickness of a base material may be 30-100 g / m < ² > as basis weight, for example.

  The adhesive layer should just be laminated | stacked on the at least single side | surface of the base material, and may be laminated | stacked on both surfaces of the base material. The thickness of the pressure-sensitive adhesive layer may be, for example, 5 μm or more, 10 μm or more, or 20 μm or more. The thickness of the pressure-sensitive adhesive layer may be 100 μm or less, or 300 μm or less. The above upper limit value and lower limit value can be arbitrarily combined. In addition, also in the following similar description, the individually described upper limit value and lower limit value can be arbitrarily combined.

  The pressure-sensitive adhesive layer contains at least a crosslinking reaction product (radiation crosslinking reaction product) having a crosslinked structure generated by irradiation with radiation. The pressure-sensitive adhesive layer may be composed only of a cross-linking reaction product, but may contain other components such as additives as components other than the cross-linking reaction product. However, the pressure-sensitive adhesive layer preferably contains substantially no solvent. Further, the pressure-sensitive adhesive layer may contain a plasticizer as an additive, but according to this embodiment, even if the pressure-sensitive adhesive layer does not substantially contain a plasticizer, Exfoliation of the keratin can be suppressed, and sufficient holding power can be obtained.

  The crosslinking reaction product includes at least an alkyl (meth) acrylate monomer having 4 to 18 carbon atoms in the alkyl group (hereinafter sometimes abbreviated as “C4-18 acrylate”), a radiation crosslinking group-containing ethylenically unsaturated monomer ( Hereinafter, it may be abbreviated as “radiation-crosslinkable monomer”) and ethylenically unsaturated polar monomer (hereinafter, sometimes abbreviated as “polar monomer”). And a monomer having a crosslinking structure derived from the radiation crosslinking group of the radiation-crosslinkable monomer. That is, the cross-linking reaction product is a cross-linking reaction product obtained by reacting the radiation cross-linking group in the radiation cross-linkable monomer by irradiation with radiation to form a cross-linked structure within or between molecules.

  The radiation may be non-ionizing radiation such as ultraviolet rays, and may be ionizing radiation such as an electron beam or γ-ray. That is, the crosslinking reaction product may be a photocrosslinking reaction product (for example, an ultraviolet crosslinking reaction product), an electron beam crosslinking reaction product, or a γ-ray crosslinking reaction product. The radiation crosslinkable monomer may be a photocrosslinkable group-containing ethylenically unsaturated monomer (for example, an ultraviolet crosslinkable group-containing ethylenically unsaturated monomer) or an electron beam crosslinkable group-containing ethylenically unsaturated monomer. It may be a gamma ray crosslinking group-containing ethylenically unsaturated monomer.

  C4-18 acrylate is a mono (meth) acrylate having an alkyl group having 4 to 18 carbon atoms, does not contain a radiation crosslinking group, and is generally nonpolar. Examples of such C4-18 acrylate include n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 3,3, 5-trimethylcyclohexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) ) And at least one selected from the group consisting of isobornyl (meth) acrylate.

  The mass ratio of C4-18 acrylate to all monomers constituting the crosslinking reaction product may be 50 mass% or more, or 70 mass% or more. The mass ratio of C4-18 acrylate to all monomers constituting the crosslinking reaction product may be 99.0% by mass or less, may be 99.5% by mass or less, and is 99.95% by mass or less. It may be. With such a content, sufficient tackiness is easily obtained.

  The radiation crosslinkable monomer may be any monomer (such as an aromatic ketone compound having an ethylenically unsaturated bond) having an ethylenically unsaturated bond and one or more radiation crosslinkable groups. A radiation cross-linking group is a functional group capable of generating a radical upon irradiation. Examples of the radiation crosslinking group include a benzophenone group, an acetophenone group, and an anthraquinone group. Examples of such radiation crosslinkable monomers include para-acryloxybenzophenone (ABP), para-acryloxyethoxybenzophenone (AEBP), para-N- (methylacryloxyethyl) -carbamoylethoxybenzophenone, 4-acryloxy. And at least one selected from the group consisting of diethoxy-4-chlorobenzophenone, para-acryloxyacetophenone, ortho-acrylamide acetophenone and acrylated anthraquinone.

  The mass ratio of the radiation crosslinkable monomer to all monomers constituting the crosslinking reaction product is 0.05 to 10% by mass. The skin adhesive tape according to the present embodiment is a liquid component having a plasticizing action because the mass ratio of the radiation crosslinkable monomer is within the above range and the mass ratio of the polar monomer is less than 3.0 mass%. The exfoliation of the keratin at the time of peeling the tape can be suppressed without containing, and a sufficient holding force can be obtained. Moreover, sufficient adhesive force and stable adhesive properties can be exhibited, adhesive residue at the time of peeling hardly occurs, and excellent removability can be exhibited. The mass ratio of the radiation crosslinkable monomer is preferably 0.06% by mass or more from the viewpoint of further suppressing adhesive residue, from the viewpoint of further excellent holding power, and from the viewpoint of further suppressing exfoliation. It is more preferable that it is 08 mass% or more. The mass ratio of the radiation crosslinkable monomer is preferably 5.0% by mass or less, and more preferably 3.0% by mass or less, from the viewpoint of suppressing the floating and peeling of the tape in practical use. That is, the mass ratio of the radiation crosslinkable monomer to all monomers constituting the crosslinking reaction product is preferably 0.06 to 5.0 mass%, and preferably 0.08 to 3.0 mass%. More preferred.

  The polar monomer is an ethylenically unsaturated monomer having no radiation cross-linking group and having polarity. The polar monomer has, for example, an ethylenically unsaturated bond and one or more polar groups. Examples of the polar group include a hydroxyl group, a carboxyl group, a carbamoyl group, an amide group, an amino group, an epoxy group, and a nitrile group.

  The polar monomer may be an acidic ethylenically unsaturated polar monomer (hereinafter sometimes abbreviated as “acidic monomer”) or a basic ethylenically unsaturated polar monomer (hereinafter abbreviated as “basic monomer”). And a neutral ethylenically unsaturated polar monomer (hereinafter sometimes abbreviated as “neutral monomer”). Examples of the acidic monomer include acidic (meth) acrylic monomers such as (meth) acrylic acid. Examples of the basic monomer include basic (meth) acrylic monomers such as N, N-dimethylacrylamide, acrylamide, acryloylmorpholine, N, N-diethylacrylamide, N-vinylpyrrolidone, and N-vinylcaprolactam. . As a neutral monomer, 2-hydroxyethyl (meth) acrylate etc. are mentioned, for example. Among these, the polar monomer preferably includes a basic monomer, and preferably includes a nitrogen atom-containing monomer such as N-vinylpyrrolidone, N, N-dimethylacrylamide, and N-vinylcaprolactam.

  The mass ratio of the polar monomer to all monomers constituting the crosslinking reaction product is less than 3.0% by mass. The mass ratio of the polar monomer may be 2.5% by mass or less, or 2.0% by mass or less from the viewpoint of further suppressing the exfoliation of the stratum corneum. In addition, the mass ratio of the polar monomer may be 0.0005% by mass or more, 0.001% by mass or more, and 0.002% by mass from the viewpoint of obtaining more sufficient adhesive force and holding power. % Or more.

  It is preferable that the mass ratio of the acidic monomer to all monomers constituting the crosslinking reaction product is 0.5% by mass or less. In this case, the increase in adhesive strength with time is further suppressed, and exfoliation of the keratin is further suppressed. From this point of view, in this embodiment, the cross-linking reaction product substantially does not contain an acidic monomer as a monomer unit (the mass ratio with respect to all the monomers constituting the cross-linking reaction product is 0.0005% by mass). Less). More preferably, the cross-linked reaction product does not substantially contain an acidic (meth) acrylic monomer, and particularly preferably does not substantially contain (meth) acrylic acid.

  The mass ratio of the basic monomer to all monomers constituting the cross-linked reaction product is preferably 0.0005 mass% or more and less than 3.0 mass%. When the mass ratio of the basic monomer is within the above range, adhesion to the substrate is strengthened, adhesive residue is less likely to be generated, adhesive strength is not excessively increased, and exfoliation of the keratin is further suppressed. The mass ratio of the basic monomer may be 0.0005% by mass or more, 0.001% by mass or more, or 0.002% by mass or more. In this case, adhesive residue is less likely to occur. The mass ratio of the basic monomer may be 2.5% by mass or less, or 2.0% by mass or less. In this case, exfoliation of the keratin is further suppressed.

  The crosslinking reaction product may further contain a copolymerizable monomer other than C4-18 acrylate, a radiation crosslinking monomer and a polar monomer as a monomer unit. Examples of other copolymerization monomers include polyfunctional monomers having two or more ethylenically unsaturated bonds and alkyl (meth) acrylate monomers other than C4-18 acrylate. Examples of the polyfunctional monomer having two or more ethylenically unsaturated bonds include poly (meth) acrylates such as alkylene glycol di (meth) acrylate (for example, 1,6-hexanediol diacrylate), and polyvinyl compounds such as divinylbenzene. It is done. In addition, the monomer which substituted the hydrogen atom of the (meth) acryl monomer with the polar group (a halogen atom etc. is included) shall be contained in a polar monomer.

  The above-mentioned cross-linking reaction product may be a cross-linking reaction product having a single polymer-derived skeleton obtained by cross-linking one type of polymer with radiation, and two or more types of cross-linking products may be cross-linked with radiation. It may be a crosslinking reaction product having a skeleton derived from two or more kinds of polymers.

  Hereinafter, as an example of the crosslinking reaction product, a crosslinking reaction product obtained by radiation-crosslinking at least a first polymer and a second polymer different from the first polymer will be described. Such a cross-linking reaction product includes a skeleton derived from the first polymer and a skeleton derived from the second polymer.

  The first polymer contains the C4-18 acrylate as a monomer unit. That is, the first polymer is a polymer that can be obtained by polymerizing a monomer containing C4-18 acrylate.

  The first polymer may contain only one or more of C4-18 acrylate as a monomer unit, but further contains the radiation crosslinkable monomer as a monomer unit. The polar monomer may be further included as a monomer, and the other copolymer monomer may be further included as a monomer unit. However, when the second polymer does not contain a polar monomer as a monomer unit, the first polymer needs to contain a polar monomer as a monomer unit.

  The mass ratio of C4-18 acrylate to all monomers constituting the first polymer may be, for example, 80 to 99.5% by mass, 90 to 99.0% by mass, 95 It may be ˜98.5% by mass. With such a content, sufficient tackiness and sufficient holding power are easily obtained.

  The mass ratio of the radiation crosslinkable monomer to all the monomers constituting the first polymer may be, for example, 0.01 to 1.0% by mass, and 0.05 to 0.5% by mass. It may be 0.1 to 0.3% by mass. When the first polymer contains a radiation crosslinkable monomer as a monomer unit within the above range, it is less than when the radiation crosslinkable monomer is contained only as a monomer unit in the second polymer. Sufficient internal cohesive force can be obtained with the addition amount of the second polymer.

  The mass ratio of the polar monomer, the mass ratio of the acidic monomer, and the mass ratio of the basic monomer to all monomers constituting the first polymer are the mass ratio of the polar monomer to all monomers constituting the crosslinking reaction product. The mass ratio of the acidic monomer and the mass ratio of the basic monomer can be appropriately adjusted so as to be in the ranges described above.

  The first polymer preferably has a glass transition temperature (Tg) calculated from the FOX equation of 0 ° C. or lower. By having such a Tg, a good adhesive force is exhibited as a skin adhesive tape. Tg is preferably −5 ° C. or lower, and more preferably −10 ° C. or lower.

  The weight average molecular weight (polystyrene conversion) by gel permeation chromatography (GPC) measurement of the first polymer may be 100,000 to 5,000,000, even if it is 500,000 to 1,500,000. Good.

  The first polymer can be obtained by polymerizing the above-described monomer by, for example, radical polymerization or ionic polymerization. In that case, arbitrary radical polymerization initiators, ionic polymerization initiators, chain transfer agents and the like can be used. The radical polymerization initiator may be a thermal polymerization initiator or a photo (for example, ultraviolet) polymerization initiator. That is, the polymerization for obtaining the first polymer may be thermal polymerization or photopolymerization. However, when the first polymer contains a radiation crosslinkable monomer (especially a photocrosslinkable group-containing ethylenically unsaturated monomer) as a monomer unit, the polymerization is performed not by photopolymerization but by other methods (thermal polymerization or the like). It is preferable. The types and blending amounts of the polymerization initiator and chain transfer initiator are not particularly limited, and can be appropriately adjusted in consideration of the molecular weight of the first polymer obtained by polymerization. Moreover, although an organic solvent may be used for superposition | polymerization, the method which does not use an organic solvent is preferable. Specifically, it is preferable to polymerize the monomer described above by the method described in the examples.

  The second polymer contains the C4-18 acrylate and the radiation crosslinkable monomer as monomer units. That is, the second polymer is a polymer that can be obtained by polymerizing a monomer containing C4-18 acrylate and a radiation crosslinkable monomer.

  The second polymer may contain only one or more of C4-18 acrylate and one or more of radiation-crosslinkable monomers as monomer units. May be further included as a monomer unit, or may be further included as the monomer unit. In addition, C4-18 acrylate, radiation crosslinkable monomer, polar monomer, and other copolymerization monomer in the second polymer may be the same as or different from those in the first polymer.

  The mass ratio of C4-18 acrylate to all monomers constituting the second polymer may be, for example, 50 to 99 mass%, 60 to 97 mass%, or 70 to 95 mass%. It may be. By setting it as such content, it becomes excellent in compatibility with a 1st polymer.

  The mass ratio of the radiation crosslinkable monomer to all the monomers constituting the second polymer may be, for example, 1.0 to 20% by mass, or 1.5 to 15% by mass. 0-10 mass% may be sufficient. With such a content, a sufficient crosslinked structure can be obtained even with a small amount of the second polymer.

  The mass ratio of the polar monomer, the mass ratio of the acidic monomer, and the mass ratio of the basic monomer to all the monomers constituting the second polymer are the mass ratio of the polar monomer to all the monomers constituting the crosslinking reaction product. The mass ratio of the acidic monomer and the mass ratio of the basic monomer can be appropriately adjusted so as to fall within the ranges described below.

  For the second polymer, the Tg calculated from the FOX equation is arbitrary, but the weight average molecular weight (polystyrene conversion) by gel permeation chromatography (GPC) measurement is preferably 50,000 or more. The weight average molecular weight is more preferably 100,000 to 1,000,000. The weight average molecular weight of the second polymer is preferably equal to or lower than that of the first polymer.

  Since the second polymer contains a radiation crosslinking group, it is mixed with the first polymer and irradiated with radiation to form a crosslinked structure with the first polymer. Compared with the case of a low molecular radiation crosslinking agent (for example, an ultraviolet crosslinking agent), the compound that causes crosslinking by radiation is a high molecular radiation crosslinking agent (for example, an ultraviolet crosslinking agent) like the second polymer. An increase in the adhesive force over time can be more effectively prevented, and the holding force is also high. That is, when the weight average molecular weight of the second polymer is 50,000 or more as described above, the performance can be further enhanced.

  The second polymer can be produced in the same manner as the first polymer. However, since the second polymer contains a monomer having a radiation crosslinking group, the polymerization is preferably performed by other methods (thermal polymerization or the like) rather than photopolymerization.

  In addition, the one where the 1st polymer and the 2nd polymer have high compatibility can manufacture a more uniform and stable skin sticking tape. Therefore, it is preferable that the solubility parameters (by the Fedors method) of the first polymer and the second polymer are approximate, for example, the solubility parameter should be within ± 3, preferably ± 2.

  The mass ratio of the second polymer to the first polymer constituting the crosslinking reaction product is preferably 1.0 to 20.0% by mass, and more preferably 1.5 to 10.0% by mass. More preferably, it is 2.0-5.0 mass%. When the skin adhesive tape is used after being sterilized, it is easy to achieve desired adhesive properties after sterilization by adjusting the mass ratio. For example, when the sterilization treatment is performed, the adhesive strength tends to decrease, but by increasing the ratio of the second polymer, it can be adjusted so as to have a desired adhesive strength after the sterilization treatment.

  The cross-linked reaction product may have a skeleton derived from a polymer other than the first polymer and the second polymer, and may have a skeleton derived from an additive such as a tackifier. Examples of tackifiers include, for example, rosin resins, coumarone-indene resins, terpene resins, terpene / phenol resins, C5 petroleum resins, C5 / C9 petroleum resins, C9 petroleum resins, and styrene copolymers. Examples thereof include polymers, alkylphenol resins, xylene resins, hydrogenated resins, and modified resins thereof.

  The above-mentioned pressure-sensitive adhesive layer containing a cross-linked reaction product is, for example, a precursor formed by applying a pressure-sensitive adhesive composition containing at least the first polymer and the second polymer on a substrate, and forming the pressure-sensitive adhesive composition. After forming the layer, it is obtained by irradiating the precursor layer with radiation (for example, ultraviolet rays). That is, the method for producing a skin adhesive tape according to the present embodiment includes, for example, a step of forming a precursor layer made of an adhesive composition on a base material having a degree of elongation of 10% or more, and a method of forming the base material on the base material. Irradiating the precursor layer made of the pressure-sensitive adhesive composition with radiation to obtain a pressure-sensitive adhesive layer containing a crosslinking reaction product on the substrate.

  In the pressure-sensitive adhesive composition, in order to obtain the above-described crosslinking reaction product, the mass ratio of the radiation-crosslinking monomer to all the monomers constituting the first and second polymers is 0.05 to 10% by mass. It is preferably 0.06 to 5.0% by mass, more preferably 0.08 to 3.0% by mass. The mass ratio of the polar monomer to all monomers constituting the first and second polymers is less than 3.0% by mass, may be 0.0005 to 3.0% by mass, -2.5 mass% may be sufficient, and 0.002-2.0 mass% may be sufficient.

  The pressure-sensitive adhesive composition can contain additives as long as the effects of the present invention are not impaired. As the additive, for example, an antioxidant, a light stabilizer, a dye, a pigment, a fragrance, a plasticizer, and the like can be used in addition to the above-described tackifier. These additives may be blended during the preparation of the pressure-sensitive adhesive composition, and may be blended during the synthesis of the first polymer and the second polymer. The content of the tackifier can be, for example, less than 20 parts by mass with respect to a total of 100 parts by mass of the first and second polymers. 0-15 mass parts may be sufficient as content of a tackifier, and 0-10 mass parts may be sufficient as it. Moreover, content of additives other than a tackifier can be 0.01-3.0 mass parts with respect to a total of 100 mass parts of a 1st and 2nd polymer, for example. The pressure-sensitive adhesive composition may not substantially contain a plasticizer. In addition, the preferable range of the mass ratio of the 2nd polymer with respect to the 1st polymer in an adhesive composition is the same as the mass ratio of the 2nd polymer with respect to the 1st polymer which comprises the crosslinking reaction mentioned above.

  The above-mentioned pressure-sensitive adhesive composition is, for example, a hot-melt pressure-sensitive adhesive composition and substantially does not contain a solvent. When the pressure-sensitive adhesive composition is a hot melt type, the viscosity at 25 ° C. of the pressure-sensitive adhesive composition is, for example, 4000 Pa · s or less, 1600 Pa · s or less, 800 Pa · s or less, 400 Pa · s or less, 200 Pa · It may be s or less, 100 Pa · s or less, 50 Pa · s or less, 20 Pa · s or less, or 10 Pa · s. In this embodiment, even when the molecular weight of the first polymer is reduced, for example, in order to make the pressure-sensitive adhesive composition into a hot-melt type, the radiation-crosslinkable monomer is irradiated by irradiating with radiation after forming the precursor layer. A cross-linked structure derived therefrom can be formed to increase the molecular weight. Therefore, the skin sticking tape according to the present embodiment has sufficient adhesive force and internal cohesion even when the mass ratio of the polar monomer to all monomers constituting the cross-linking reaction product is less than 2% by mass. .

  The method for preparing the pressure-sensitive adhesive composition is not particularly limited. When the pressure-sensitive adhesive composition is a hot-melt type, it can be prepared using a standard melt mixing apparatus such as a reciprocating single-screw extruder, a twin-screw extruder, and a kneader. In this case, two or more devices may be used on the same line in order to sufficiently melt and mix the composition.

  The method for applying the pressure-sensitive adhesive composition to the substrate is not particularly limited. For example, methods such as roll coating, flow coating, dip coating, spin coating, spray coating, knife coating, and die coating can be used.

Irradiation can be performed in the presence of oxygen or in the presence of an inert gas. Irradiation can be performed by a known method. For example, when irradiating with ultraviolet rays, UV irradiation can be performed using a UV lamp. As the UV lamp to be used, a lamp having a strong emission spectrum in the UV-C region that activates benzophenone, that is, a high-pressure mercury lamp, a metal halide lamp, or the like can be used. For the presence of oxygen, irradiation energy of UV-C region is preferably 10 to 100 mJ / cm ^2, more preferably 20~80mJ / cm ^2.

  The above-mentioned skin sticking tape can be used in applications requiring sterilization because it can maintain sufficient adhesive force and holding power even when sterilized by γ-ray irradiation, electron beam irradiation, etc. Can do. The dose of γ rays in the sterilization process may be, for example, 20 to 45 Gky, and the dose of electron beams may be, for example, 20 to 45 Gky.

  Hereinafter, the present invention will be described in detail based on examples. In addition, this invention is not limited to a following example.

[Material list]
A list of materials used in the examples and comparative examples is shown in the table below.

[Preparation of Acrylate PSA1-3]
Using the materials shown in Table 2, “acrylates PSA1 to 3” were obtained according to the method described in WO96 / 07522.

[Preparation of Photocrosslinkable Polymer 1]
70.00 parts by weight 2EHA, 20.00 parts by weight 2EHMA, 5.00 parts by weight DMAA, 5.00 parts by weight AEBP, 100.00 parts by weight ethyl acetate (solvent), 0.75 parts by weight t-Dodecanethiol and 0.12 parts by weight of V-65 were mixed in a reaction vessel. The reaction vessel was replaced with nitrogen gas and reacted at 50 ° C. for 24 hours. As a result, a 50% by mass ethyl acetate solution of “photocrosslinkable polymer 1” was obtained. “Photocrosslinkable polymer 1” is produced in ethyl acetate, and “photocrosslinkable polymer 1” in the preparation of a tape for skin attachment described later is obtained from a 50% by mass ethyl acetate solution of “photocrosslinkable polymer 1”. What removed the solvent (ethyl acetate) was used.

[Example 1]
(Preparation of tape for skin application)
A pressure-sensitive adhesive composition was prepared so that the materials shown in Table 3 were mixed in the amount shown in the same table (unit: part by mass). Specifically, “acrylate PSA1” was extruded at 140 ° C. using a single screw extruder and supplied to the twin screw extruder at 3.00 kg / h. Further, “photocrosslinkable polymer 1” was supplied to the twin-screw extruder at 0.18 kg / h (amount of 6 parts by mass with respect to 100 parts by mass of “acrylate PSA1”). In the twin screw extruder, the barrel temperature was 170 ° C., and “acrylate PSA1” and “photocrosslinkable polymer 1” were kneaded to obtain a hot-melt pressure-sensitive adhesive composition.

Next, Japanese paper was placed as a backing on a laboratory coater unwinder, and the pressure-sensitive adhesive composition was applied onto the backing. The pressure-sensitive adhesive composition was applied at 160 ° C. and 6.7 m / min. Moreover, the application amount (the amount after drying) of the pressure-sensitive adhesive composition was 40 g / m ² . Next, the backing material coated with the adhesive composition was passed through a UV chamber (manufactured by Eye Graphics Co., Ltd.) and irradiated with ultraviolet rays with a metal halide lamp to form an adhesive layer on the backing material. The UV-C intensity measured with a UV meter (manufactured by EIT, UV Power Pack II) was 45 mJ / cm ² .

[Examples 2-8 and Comparative Examples 1-2]
Except having supplied the material shown in following Table 3 to the twin-screw extruder so that it may become the compounding quantity (unit: mass part) shown in the same table, and producing the adhesive composition, it was carried out similarly to Example 1, The skin adhering tapes of Examples 2 to 8 and Comparative Examples 1 and 2 were produced.

[Comparative Example 3]
Prepared as “Skin Bond” (base material: Japanese paper, Adhesive: Depopulated acrylic adhesive, “Excellent Skin Bond” is a registered trademark) manufactured by Nitto Denko Co., Ltd. did.

[Comparative Example 4]
“Micropore” (base material: non-woven fabric, pressure-sensitive adhesive: acrylic pressure-sensitive adhesive) manufactured by 3M Co., Ltd. was prepared as a skin adhesive tape of Comparative Example 4.

  About the Example and the comparative example, the adhesive characteristic of the tape for skin sticking was evaluated by the test shown below. The results are shown in Table 4.

[Test 1: Peel adhesion test]
Cut skin adhesive tape into 2.54 cm (1 inch) width and 10.16 cm (4 inch) length to make a test sample, and measure 180 ° peel adhesion to stainless steel plate using the test sample. A test was carried out. Specifically, the test sample was affixed to a stainless steel plate by passing the test sample through a 2.1 kg (4.5 pound) roller four times. After aging for about 1 hour at a temperature of about 22 ° C. and a relative humidity of 40%, Instruments, Inc. The test sample was peeled at a peel rate of 300 mm / min in a 180 ° configuration using a model 3M90 split / peel tester available from

[Test 2: Shear strength test]
Cut the skin adhering tape into 2.54 cm (1 inch) width and 10.16 cm (4 inch) length and use it as a test sample, and measure the shear strength (holding power) against stainless steel using the test sample. A test was carried out. Specifically, by passing the test sample four times through a 2.1 kg (4.5 pound) roller, an area of 2.54 cm (width 2.54 cm) in the length direction from the end of the test sample is made of stainless steel. Affixed to the edge of the steel plate. Next, the temperature was kept at 25 ° C. and the relative humidity was kept at 50%, and the mixture was left for 24 hours. After a lapse of 24 hours, a 500 gram weight was suspended from the test sample protruding from the stainless steel plate (width 2.54 cm, length 7.62 cm), and the time until the weight dropped was measured. did.

[Test 3: Adhesive residue test]
In the shear strength test, the area ratio of the adhesive (adhesive layer) residue that remained on the stainless steel plate after the weight fell (ratio to the area of the part where the test sample was attached) Asked.

[Test 4: Skin adhesion test]
The skin adhering tape was cut into dimensions of 2.54 cm (1 inch) wide and 7.62 cm (3 inch) long, and used as a test sample. The test sample was affixed on the human subject's back so that the longitudinal direction of the test sample was perpendicular to the spine. The test sample was attached by pressing with a 2 kg roller. Then, after 10 minutes (indicated as T0 in Table 4), after 24 hours (indicated as T24 in Table 4) and after 48 hours (indicated as T48 in Table 4), the adhesion tester was connected. The test sample was peeled from the back by using the mechanical tension device (manufactured by Zwick), and the adhesive force at that time was measured. Specifically, a 2.54 cm (1 inch) wide metal clip to which a 11.4 kg test line is attached is attached to a test sample with a width of 2.54 cm (1 inch), and the test line is attached to the back. The sample was pulled at a speed of 30.48 cm / min (12 inch / min) in the horizontal direction (180 °) and parallel to the longitudinal direction of the test sample. Table 4 shows an average value (N / 2.54 cm) of measured values from the start of peeling of the test sample in the above operation to complete removal.

[Test 5: Skin adhesion levitation test]
In the skin adhesion test, the test sample after 24 hours and 48 hours after the test sample was attached to the back was visually observed, and the area ratio of the part that was lifted (peeled) from the skin (for test The ratio to the area of the sample was determined, and the following grading was performed.
0 No lift is observed.
More than 0 and less than 1 The area ratio of the raised part is more than 0% and less than 1%.
More than 1 and less than 2 The area ratio of the raised part is more than 1% and 25% or less.
More than 2 and less than 3 The area ratio of the raised part is more than 25% and less than 50%.
3 to 4 or less The area ratio of the raised part is more than 50% and 75% or less.
4 to 5 or less The area ratio of the raised part is more than 75% and 100% or less.
Table 4 shows an average value obtained by averaging the results of the 14 tests. Preferred skin sticking tapes generally exhibit an average grade of less than about 2.5.

[Test 6: Skin adhesive residue test]
After peeling off the test sample in the skin adhesion test, the part where the test sample was attached was visually observed, and the area of the part where the adhesive (adhesive layer) residue remained on the skin surface was present The ratio (ratio to the area of the portion where the test sample was affixed) was determined, and the following grading was performed. In addition, the said evaluation was done about the test which peeled after 24 hours passed and 48 hours passed after a test sample was affixed on the back.
0 No residue is seen.
More than 0 and less than 1 Area ratio of the residue is more than 0% and less than 1%
More than 1 and less than 2 The area ratio of the portion where the residue exists is more than 1% and 25% or less.
More than 2 and less than 3 The area ratio of the portion where the residue exists is more than 25% and 50% or less.
More than 3 and less than 4 The area ratio of the portion where the residue exists is more than 50% and 75% or less.
More than 4 and less than 5 The area ratio of the portion where the residue exists is more than 75% and 100% or less.
Table 4 shows an average value obtained by averaging the results of the 14 tests. Preferred skin sticking tapes generally exhibit an average grade of less than about 2.5.

[Test 7: Exfoliation test during exfoliation]
In the skin adhesive strength test, an arbitrary point on the adhesive surface of the test sample which was peeled off after 24 hours from pasting the test sample on the back was measured with an infrared transmittance meter (ATR method). Absorbance at the frequency (1539 cm ⁻¹ , 1630 cm ⁻¹ ) of the keratin (protein) is measured, the absorbance when measuring the actual skin is 100%, and the absorbance of the adhesive alone not attached to the skin is 0% The absorbance of the keratin adhering to the adhesive surface was recorded in%, and the average value was calculated. The average value obtained was converted to mg based on the mass when the absorbance was 100%, and the amount of keratin deposits per unit area (mg / cm ² ) was determined.

[Test 8: Re-adhesion test]
In the skin adhesion test, a 180 ° peel adhesion test was performed by the above-described method using a test sample that had been peeled off after 24 hours had been pasted on the test sample.

After sterilizing the skin adhesive tapes of Examples 2 to 8 and Comparative Example 2, the above peel adhesion test and shear strength test were performed. Specifically, sterilization treatment was performed by irradiating the skin adhesive tape with γ rays or electron beams under the following conditions. The results are shown in Table 5.
γ-ray: 25 kGy (Target dose), 28.3 to 28.6 kGy (Actual dose)
γ-ray: 45 kGy (Target dose), 45.3. -46.2 kGy (Actual dose)
Electron beam: 45 kGy (Target dose), 45.3. -46.2 kGy (Actual dose)

  As shown in Table 5, it was confirmed that the skin adhering tapes of the examples exhibited sufficient adhesive force and holding force even after sterilization treatment.

Claims (6)

A base material having an elongation of 10% or more, and an adhesive layer laminated on at least one side of the base material,
The pressure-sensitive adhesive layer contains, as monomer units, an alkyl (meth) acrylate monomer having an alkyl group having 4 to 18 carbon atoms, a radiation crosslinking group-containing ethylenically unsaturated monomer, and an ethylenically unsaturated polar monomer. Contains cross-linking reactants,
The mass ratio of the radiation-crosslinking group-containing ethylenically unsaturated monomer to all monomers constituting the crosslinking reaction product is 0.05 to 10% by mass,
The skin adhering tape, wherein a mass ratio of the ethylenically unsaturated polar monomer to all monomers constituting the cross-linking reaction product is less than 3.0% by mass. The cross-linking reaction product includes a skeleton derived from a first polymer containing an alkyl (meth) acrylate monomer having an alkyl group having 4 to 18 carbon atoms as a monomer unit, and an alkyl having an alkyl group having 4 to 18 carbon atoms ( A skeleton derived from a second polymer containing a (meth) acrylate monomer and a radiation crosslinking group-containing ethylenically unsaturated monomer as monomer units,
The skin sticking tape according to claim 1, wherein at least one of the first polymer and the second polymer further contains an ethylenically unsaturated polar monomer as a monomer unit. At least one of the first polymer and the second polymer includes a basic monomer as the ethylenically unsaturated polar monomer,
The skin sticking tape according to claim 1 or 2, wherein a mass ratio of the basic monomer to all monomers constituting the crosslinking reaction product is 0.0005 mass% or more and less than 3.0 mass%.   The said cross-linking reaction product is a skin sticking tape according to any one of claims 1 to 3, which does not substantially contain an acidic monomer as a monomer unit.   The said cross-linking reaction product is a skin sticking tape according to any one of claims 1 to 4, which does not substantially contain acrylic acid as a monomer unit. A step of irradiating a precursor layer made of a pressure-sensitive adhesive composition formed on a substrate having an elongation of 10% or more to obtain a pressure-sensitive adhesive layer containing a crosslinking reaction product on the substrate; , A method for producing a skin adhesive tape,
The pressure-sensitive adhesive composition includes a first polymer containing an alkyl (meth) acrylate monomer having an alkyl group having 4 to 18 carbon atoms as a monomer unit, and an alkyl (meth) having an alkyl group having 4 to 18 carbon atoms. A second polymer containing an acrylate monomer and a radiation crosslinkable group-containing ethylenically unsaturated monomer as a monomer unit,
At least one of the first polymer and the second polymer further includes an ethylenically unsaturated polar monomer as a monomer unit,
The mass ratio of the radiation-crosslinking group-containing ethylenically unsaturated monomer to all monomers constituting the first and second polymers is 0.05 to 10% by mass,
The manufacturing method of the skin sticking tape whose mass ratio of the said ethylenically unsaturated polar monomer with respect to all the monomers which comprise the said 1st and 2nd polymer is less than 3.0 mass%.